Congenital syphilis is the oldest recognized congenital infection, and continues to account for extensive global perinatal morbidity and mortality today. Serious adverse pregnancy outcomes caused by maternal syphilis infection are prevented with screening early in pregnancy and prompt treatment of women testing positive. Intramuscular penicillin, an inexpensive antibiotic on the essential medicine list of nations all over the world, effectively cures infection and prevents congenital syphilis. In fact, at a cost of $11–15 per disability adjusted life year (DALY) averted, maternal syphilis screening and treatment is among the most cost-effective public health interventions in existence. Yet implementation of this basic public health intervention is sporadic in countries with highest congenital syphilis burden. We discuss the global burden of this devastating disease, current progress and ongoing challenges for its elimination in countries with highest prevalence, and next steps in ensuring a world free of preventable perinatal deaths caused by syphilis. Mother-to-child transmission of syphilis, that is, congenital syphilis, has been documented since the 15th century . In lighTreponema pallidum, the bacteria causing syphilis, is able to traverse the placenta early in pregnancy and lead to fetal exposure; however, fetal compromise is generally not manifested until later in the second or third trimesters with maturation of the fetal immune system [Globally just over 2 million pregnant women test positive for syphilis each year, comprising 1.5 percent of all pregnancies worldwide , 10. Tree system –8. A smaT. pallidum. This situation results in an estimated 692,100 to 1.53 million adverse pregnancy outcomes each year caused by syphilis  estimates that globally the majority of maternal syphilis infections are untreated and of sufficiently high-titer (RPR ≥ 1 : 8) to cause significant fetal exposure to syphilis  [8, 11–1Adverse pregnancy outcomes caused by syphilis can be almost entirely averted through early identification of maternal infections through antenatal screening programmes, and prompt treatment of women with positive tests with a single dose of long acting penicillin prior to 24 weeks gestation . Maternano laboratory access, thus testing is often simply not done at all. In antenatal facilities with access to laboratories able to conduct RPR tests , women must often go to a separate site for testing, incurring additional transportation costs and waiting time above the basic antenatal visit. Additionally, women are often asked to pay for the tests themselves, a substantial barrier for many women [ High-burden countries have reported numerous barriers that limit effective screening and treatment as part of basic antenatal health services . Access ny women , 20–23.  Even in places that could feasibly provide testing routinely, further systems level issues such as stockouts of critical commodities and inadequate numbers or distribution of clinical or laboratory providers can limit testing. Also, for women with positive tests, treatment can be delayed when results are not provided in a timely fashion, or when treatment is difficult to access. Women with positive screening tests may not learn about positive results until a later clinic visit, and are often asked to travel to another site for treatment—for which they often, again, have to pay themselves. Furthermore, while most programmes collect data on maternal screening, few collect data on provision or timing of treatment, and thus programmes may be unaware of their deficiencies in providing prompt and appropriate treatment , 23. AnoTaking into consideration the current challenges to congenital syphilis prevention, WHO has outlined a strategic plan of action for the global elimination of congenital syphilis  as a pubcountry-driven to adapt to local needs; integrated to ensure that the effort strengthens existing STI, HIV, prenatal, and maternal and newborn health services; rights-based to ensure that all individuals have the knowledge to participate in decision-making about their health and access to high-quality care, and collaborative so that government bodies, donors, and communities work together to optimize use of scarce resources. WHO has also outlined a series of guiding principles upon which the global congenital syphilis elimination strategy was developed: At a country level, WHO outlined a strategy consisting of four pillars with corresponding specific objectives of actions to be undertaken . The pilensure advocacy and sustained political commitment for a successful health initiative,increase access to, and quality of, maternal and newborn health services,screen and treat pregnant women and partners, andestablish surveillance, monitoring, and evaluation systems. The global initiative emphasizes that congenital syphilis elimination can contribute directly to three of the Millennium Development Goals (MDGs) by reducing child mortality (MDG4) through reductions in perinatal deaths and low-birth-weight infants; improving maternal health (MDG5) through reductions in late fetal losses and stillbirths and through a decreased burden of syphilis in pregnant women, and combating HIV/AIDS, malaria and other diseases (MDG6) through combined, systematic screening for HIV and syphilis in pregnancy with an emphasis on strengthening antenatal and postpartum health systems.Although some countries routinely monitor reports of congenital syphilis as a routine part of public health reporting, in general, case reporting of congenital syphilis is problematic as its definitive diagnosis is not easy. To address this, a WHO-led working group has identified a set of outcome and process indicators that together are feasible measures of programme progress and impact on congenital syphilis elimination. Monitoring the proportion of stillbirths attributable to syphilis was identified by the working group as the most promising outcome indicator, and it was recommended that a target for nations should be that “the proportion of stillbirths attributable to syphilis in the mother be less than 2 percent.”  The stillbirth target of 2 percent was chosen because stillbirth is both the most common and most severe outcome caused by untreated maternal syphilis. Among women with active syphilis, 17 to 40 percent of pregnancies result in stillbirth, and the risk of stillbirth has been reported as ten to 18 times the background rate of stillbirth (approximately 2 percent) , 6.  Three critical process indicators were also identified to monitor programme progress, all involving collection of local data. These are (1) the proportion of women tested for syphilis at their first antenatal care visit, (2) the proportion of pregnant women with a positive test for syphilis, and (3) the proportion of positive women treated for syphilis, ideally by 24 weeks. These few process indicators, along with currently collected indicators on estimated number of pregnancies and coverage of antenatal screening, potentially allow countries to calculate a summary process indicator that estimates overall programme effectiveness, that is “the estimated proportion of all syphilis-positive pregnant women treated by 24 weeks of gestational age.” This indicator is important for countries to ascertain since treatment sufficiently early in pregnancy (prior to 24 to 28 weeks) is necessary to avert the adverse effects of syphilis in pregnancy in most situations [In order to raise funds for the goal of eliminating congenital syphilis, WHO and its partners have developed an Investment Case for resource mobilization and to raise awareness of the issue and the proposed solutions. Cost calculations within the Investment Case have highlighted the significant DALY burden associated with untreated syphilis in pregnant women and have demonstrated how this DALY burden disproportionately affects people in low- and middle-income countries. The Investment Case shows how the elimination of congenital syphilis is a relatively “easy win” for programmes in affected countries as the intervention is relatively simple, highly cost-effective, technically feasible, and already politically acceptable . Moreover, the Investment Case stresses that elimination of congenital syphilis is timely for countries that are aiming to reach their Millennium Development Goal commitments by 2015. With sufficient resources, several additional areas can be better addressed to ensure that public health efforts aimed at the global elimination of congenital syphilis are effective, sustainable, and support overall MCH systems strengthening. As noted, a number of barriers currently exist that limit maternal syphilis screening and treatment efforts in developing world settings. Despite this situation, evidence based on current programmes supports that many of these barriers can be effectively countered if resources and efforts focus on antenatal health systems strengthening , 23. An  Health service research studies have identified that another means of ensuring sustainability of programmes is through decentralization of laboratory services, such as provision of same day testing and treatment through rapid point-of-care tests , 20–23.  Another commonly reported barrier has been a requirement that screening and treatment costs are borne by the patient. Provision of free-of-charge or low-cost testing and treatment through government programmes has proven important in some settings to ensure the highest risk women are effectively screened and, if positive, treated . This po An especially difficult barrier to surmount in many settings is ensuring adequate human resources. In particular, shortfalls in clinical faculty and the absence of training and student mentoring opportunities can complicate strategies for eliminating congenital syphilis. As a result, medical, nursing and midwifery trainees not only lack updated professional curricula and learning materials  but also lack practical experience. Addressing this requires the inclusion of current curricula and protocols within pre-service education as well as taking opportunities to observe and provide holistic antenatal care in which syphilis prevention and treatment are incorporated into service delivery. Equally important is engaging national accreditation and credentialing bodies in efforts focused on the elimination of congenital syphilis. An additional opportunity for influencing provider practice is through partnering with global professional associations, such as, the International Federation of Gynecology and Obstetrics (FIGO), the International Confederation of Midwives (ICM) and the International Council of Nurses (ICN). Such organizations are vested in advancing global standards of care within their respective profession and can greatly influence syphilis prevention (and its appropriate adaptation) in high-burden countries. Supporting the creation of strong, sustainable health systems that are responsive, efficient and equitable is now recognized as a key component of improving health for all –27. The  However, an inherent challenge lies in striking an appropriate balance between achieving programme and disease-specific goals while at the same time ensuring long-term sustainability through well-functioning and adequately-resourced health systems. This challenge also provides an opportunity in that investments that strengthen health systems can be leveraged to ensure that, in nations with high perinatal morbidity, congenital syphilis interventions are part of the comprehensive MCH systems strengthening efforts. Similarly, partnering with other global health initiatives such as the Global Fund   and the Untreated maternal syphilis infection continues to account for large numbers of perinatal deaths worldwide, primarily in nations with moderate to high community prevalence of syphilis and weak health systems. These perinatal deaths are preventable with sufficiently early antenatal syphilis screening and prompt treatment of women testing positive. This highly cost-effective intervention has been demonstrated to be successfully achieved in several high-burden settings through strengthening current health systems. Now—in the context of Millennium Development Goals aimed at promoting infant health and averting preventable deaths—is a prime opportunity to address this old disease through promoting stronger antenatal health systems.  The 2007 WHO initiative for the global elimination of congenital syphilis provides a framework for this effort. The monitoring and evaluation plan developed with support from representatives of high-burden nations provides a means of ensuring progress and accountability through enhancing existing data systems. In addition, the Investment Case developed by WHO and partners offers a potential to identify the resources needed to achieve congenital syphilis elimination over the next five years in ten of the world's highest burden countries. Evaluations of current programmes have helped identify several of the existing barriers to current maternal syphilis screening and treatment efforts as well as potential solutions to address them. Key among these is a need to support overall health systems strengthening. Now remains the important step of bringing this effort to fruition through integration with other programmes, often disease-specific efforts, aimed at reducing maternal and infant morbidity and mortality. Effective partnerships, provider training, and empowerment can help support this critical process aimed at improving overall infant health.


EHP 116:886–892; Verner et al.][.Persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) are ubiquitous chemical compounds that persist in the environment and bioaccumulate through the food web. Although experiments have shown that POPs stimulate the proliferation of human cancer cell lines, epidemiologic studies of POP-associated cancer risk have yielded inconsistent results, possibly because of the lack of tools for estimating lifetime exposures to these chemicals. Now, however, researchers have developed a new physiologically based pharmacokinetic (PBPK) modeling approach that can potentially be used in epidemiologic studies to simulate lifetime toxicokinetics of POPs in women Previous biological assessments have been limited to measuring POP levels in blood or tissue samples collected around the time of breast cancer diagnosis. However, such assessments may not reflect the body burden during earlier, potentially critical exposure points in a woman’s life such as the fetal, postnatal, and adolescent periods.In contrast, the new model integrates the relevant processes of absorption, distribution, metabolism, and elimination to estimate lifetime blood and tissue exposure and levels during any hypothesized time window of susceptibility in breast cancer development. The model also predicts how various types of relevant lifetime physiologic changes—such as body weight variation, pregnancy, excretion of POPs through lactation, and aging—will influence the kinetics of a compound in a woman throughout her life. The model enables the estimation of interindividual differences in POP exposures through the use of physiologic information obtained from questionnaires in epidemiologic studies.The researchers found that lactation and weight change histories had the greatest impact on the toxicokinetic profile throughout life. According to the model, the longer and later in life lactation occurred, the lower the woman’s blood POP concentration at age 55 . Similarly, variations in body weight throughout life had a greater impact than average body weight on blood POP concentrations, possibly because weight loss is accompanied by unloading of POPs into the blood via lost adipose tissue. This means that quantitative information on both lactation and body weight histories is critical when evaluating past POP exposures.If, as some researchers hypothesize, breast cancer is related to POP exposures at specific time windows of susceptibility during a woman’s lifetime, lactation and body weight histories must be considered in studies of POP exposures and breast cancer risk. Depending on when such physiologic events occur, women having similar POP concentrations at the age of diagnosis may have had completely different internal levels at a time that may be critical to the formation of breast cancer. The proposed PBPK modeling approach therefore could be used in environmental epidemiology research to circumvent limitations inherent in relying on late-life sampling for past exposure assessments.


It is widely agreed that numbers automatically activate a magnitude representation. Nevertheless, so far no systematic evaluation of the neuro-cognitive correlates has been provided for the case of auditorily presented numbers.To address this question, we presented spoken number words in three different tasks  as well as spoken pseudowords in an fMRI study.We found IPS activation typically associated with magnitude processing in all tasks with numerical stimuli only. Interestingly, directly contrasting the two semantic tasks magnitude comparison (magnitude-relevant) and parity judgement (magnitude-irrelevant) revealed a left lateralized predominance within the IPS for the processing of parity information as compared to a right lateralization for number magnitude for auditorily presented number words.In summary, our results suggest a highly automatic activation of number magnitude for spoken number words similar to previous observations for visually presented numbers, but also indicate that the issue of hemispheric asymmetries deserves specific consideration. Number magnitude and parity probably represent the two most important characteristics of natural numbers when classifications regarding the similarity of numbers have to be made . In thiGenerally, quantity information is supposed to be represented as analogue magnitudes aligned in ascending order along a nonverbal, logarithmically compressed, left-to-right oriented mental number line  or lesiFirst evidence regarding the neural correlates of auditorily perceived numbers comes from a study by Eger and colleagues . In thisA first step towards a more comprehensive evaluation of magnitude relevant and irrelevant activation came from Wang et al. . In theiTaken together, there is currently no systematic analysis evaluating possible differences in the neural correlates of processing auditorily presented numbers in either magnitude relevant or magnitude irrelevant conditions such as magnitude comparison and parity judgement, respectively. However, before elaborating on the specific objectives of the current study, a general issue about interpreting IPS activation shall be addressed.The study by Cappelletti et al.  mentioneTaking into account these considerations the choice of passive mental tasks requiring no explicit, e.g., manual response, seems appropriate to keep activation related to response preparation and/or execution at a minimum. This approach, which is commonly used in neuroimaging  to differentiate neural correlates associated with more or less automatic activation of the number magnitude representation.We pursued this question using four mental numerical and non-numerical tasks and pink noise as a baseline condition:(i) To establish a baseline condition, pink noise was presented with no explicit and/or implicit processing of numerical information. (ii) By using a passive listening task utilizing German number words we intended to avoid activation related to response selection. (iii) To evaluate whether or not the activation observed when listening to number words is indeed number-related, passive listening to German pseudowords was additionally used as non-numerical control task. (iv) A number magnitude comparison task was employed as an indicator for explicit number magnitude processing (for a review see ). (v) FiTwo main questions were examined: (i) What is the typical activation pattern for the processing of auditorily presented number words? (ii) Is it possible to identify differences in localization and/or intensity of fMRI signal change due to the processing of either magnitude relevant tasks (such as number magnitude comparison) or magnitude irrelevant tasks (such as parity judgement)? Taking into account the results of Cappelletti et al.  allowed The corresponding analyses were conducted in three consecutive steps starting from checking whether participants indeed processed the auditorily presented numbers in the respective tasks to much more specific contrasts investigating possible differences and similarities of the neural correlates of a magnitude relevant number comparison task and a magnitude irrelevant parity judgement task:In the first step, all tasks were contrasted to the baseline condition . Generally, for the current auditory presentation of German number words we expected to observe IPS activation typically associated with number processing. However, the respective comparisons also allow for more specific inferences to be drawn: (a) The contrast of passive listening to number words vs. pink noise should indicate activation related to (implicit) magnitude processing not contaminated by processes of response selection. (b) Contrasting number magnitude comparison to pink noise should specifically yield magnitude related activation to auditory stimuli. Moreover, we reasoned that when intraparietal activation due to passive listening to number words is already driven by quantity processing, then IPS activation should be higher for the magnitude comparison task as it requires explicit processing of number magnitude information. (c) Comparing parity judgement to pink noise should be informative regarding the neural correlates of parity information processing when being presented auditorily.In the second step, passive listening to number words was contrasted to passive listening to pseudowords to isolate activation reflecting task irrelevant automatic magnitude processing. This analysis was used to clarify whether the contrasts between the numerical experimental conditions and the pink noise baseline reveal specific information about the processing of numerical magnitude instead of other potential variables, such as differences in attention deployed to meaningful (number words) versus meaningless (pseudowords) auditory stimuli.Finally, in the third and most specific step the task specific activation for magnitude comparison and parity judgement were directly contrasted. Thereby, we aimed at investigating differences in the activation patterns for magnitude comparison and parity judgement.Taken together, the research questions driving the current study were threefold: (i) What is the activation pattern associated with the processing of auditory numerical stimuli? (ii) Can activation related to (implicit) magnitude processing be found whenever the auditory stimulus contains numerical words, irrespective of whether there is no task at hand or the task at hand is asemantic numerically? (iii) Are there any differences and/or similarities in localization and/or intensity of fMRI signal change specifically associated with either magnitude comparison  and/or parity judgement ?17 male German-speaking students participated in the current study . All participants were right-handed and reported no neurological or arithmetic impairment. Participants were recruited on a volunteer basis and provided their written informed consent in accordance with the protocol of the Ethics Committee of the Medical Faculty of the RWTH Aachen University. One participant had to be excluded from the analysis due to technical problems in recording the imaging data.As the current study was part of a larger study, stimulus material comprised German pseudowords, pseudowords similar to number words, and German number words ranging from 0 to 9, all of them obeying standard German phonotactic constraints. Corresponding pairs of stimuli  were created such that their number of syllables and phonemes as well as, for the only bisyllabic pair ("sieben" (seven) vs. "leumer"), also the segmental structure was identical  Passive listening: In the first three runs participants had to listen passively to spoken German pseudowords, pseudowords similar to number words and finally spoken number words, respectively. (ii) Phoneme detection: In the next three runs participants had to decide mentally whether or not the spoken stimuli presented  contained the phoneme /f/ or /s/. This was the case for half of the stimuli. (iii) Parity judgement: In the seventh run, participants were asked to decide mentally whether the presented number word corresponds to an even  or an odd number . (iv) Number Comparison: In the last run only the numbers from 1 - 4 and 6 - 9 were presented and participants were supposed to mentally compare the magnitude of the number word to the fixed standard of 5.As the current study aimed at investigating the interrelation of the representations of number magnitude as well as parity information, data acquired in the phoneme detection tasks as well as in runs using words similar to number words were not considered in the subsequent analyses. Exactly the same auditory stimuli were used for all tasks on number words meaning that for passive listening, parity judgement as well as magnitude comparison the same number word recordings were presented. This ensured that possible activation differences between that set of tasks cannot be attributed to differences in low-level auditory features. Instead, this approach should allow for identifying different levels of semantic processing.Run order was not randomized so that all participants had to perform the two semantic numerical tasks  last. Thereby, activation in the non-semantic tasks  was not influenced by preceding tasks requiring semantic evaluation of numerical information.Each run consisted of an off-on-off-on-sequence lasting for 180 seconds. Every on-phase comprised 20 spoken number words, whereas in every off-phase a neutral sound (pink noise) was presented which was identical to the spoken numbers with regard to frequency, modulation, and duration. Activation during these off-phases served as a baseline condition. Trial order was pseudo-randomized to preclude any systematic confounding between condition and stimulus order as each participant was presented the same sequence of trials. Additionally, trial order was chosen with the constraint that the same decision  was not to be made more than 3 times in a row. Each run started with a different sequence of words to prevent any expectation regarding the number following. Each word was presented twice per on-phase.Participants were lying in the scanner and listening to the stimuli presented auditorily via headphones. Participants had to perform the active tasks  mentally without giving any overt response. Since IPS activation has also been shown to be associated with processes of response preparation  as well One functional imaging run sensitive to blood oxygenation level-dependent (BOLD) contrast was recorded for each participant with the Philips 1.5T Gyroscan MRI system . The experimental trials were presented in a box-car design at a mean rate of one trial every 2.25 seconds. Auditory presentation of the number words lasted from 800 - 1000 ms. In one run, 48 scans were acquired (60 × 3 seconds (TR) covered about 180 seconds). Two initial dummy scans, which were not recorded for data analysis, were used to establish equilibrium magnetization.The fMRI time series was corrected for movement artefacts and unwarped in SPM2. Images were motion corrected and realigned to each participant's first image. Data were normalized into standard stereotaxic space. Images were resampled every 3.5 mm using standardized interpolation and smoothed with a 7 mm FWHM Gaussian kernel to accommodate inter-subject variation in brain anatomy and to increase signal-to-noise ratio in the images. The data were high-pass filtered (128 s) to remove low-frequency signal drifts and corrected for autocorrelation assuming an AR(1) process for the time-series of data. Brain activity was convolved over all experimental trials with the canonical hemodynamic response function (HRF). Localization of activation peaks was determined using the Co-Planar Stereotaxic Atlas of the Human Brain by Talairach and Tournoux  as well Complex contrasts were generally masked inclusively making sure that in a complex contrast  only activation in those voxels gets displayed which were already activated (not deactivated) in the minuend (here: A). In order to display the results of analyses consistently, we generally chose a cluster size of k = 10 voxels.Analysis of fMRI data was based on all trials. As mentioned above, the analyses were conducted in three consecutive steps. The description of the results will follow these steps. To pursue our first goal of evaluating whether the tasks employed in the present study elicited magnitude-related activation when they were presented auditorily, the activation pattern observed in each individual task was contrasted to the activation of the control task.p < .0001. This comparison already indicated magnitude-related activation in the bilateral intraparietal sulci [Brodmann Area (BA) 7 and BA 40], although no response selection was required in either task  revealed magnitude-related activation in the bilateral intraparietal sulci (BA 7 and BA 40), which corresponds to magnitude-related activity previously seen in the number comparison task with visual stimulus presentation. Furthermore, task specific activation was also observed in the right precuneus (BA 7), the bilateral supramarginal gyri (BA 40), the bilateral middle frontal gyri (BA 6) and the right medial frontal gyrus (BA 6) . Further maxima of activation were found in the right supramarginal gyrus (BA 40), the bilateral dorsolateral prefrontal cortices , the right inferior frontal gyrus , the left superior temporal gyrus [Wernicke's area (BA 22)], the left cingulate (BA 32), superior frontal (BA 6) and precentral gyrus (BA 6), the bilateral middle frontal gyri (BA 6), the left insula, and the right lentiform nucleus  yielded activation in the bilateral intraparietal sulcus (BA 40), extending in the right hemisphere into the posterior intraparietal sulcus (BA 40) and in the left hemisphere into the supramarginal gyrus  to a non-numerical task (passive listening to pseudowords), which involves auditory stimuli that do not contain any numerical information, activation reflecting numerical processing could be isolated.Finally, in the third and last step, the activation patterns indicating task specific processing in magnitude comparison and parity judgements were directly compared to investigate possible differences between number comparison and parity judgement.p < .005, both tasks with respect to the pink noise baseline . Further clusters of activated voxels  - a cortex site generally assumed to and typically found to be activated by number processing (for a review see ). More sThe present study aimed at evaluating the neural correlates of number magnitude comparison and parity information. Therefore, it was intended to discern IPS activation related to magnitude processing from IPS activation induced by other processes such as response selection/execution ,32,30, hEvidence for the validity of our data comes from several different aspects. First, the different localizations and intensities of the fMRI signal observed for the different tasks indicated that participants indeed performed different mental tasks. More detailed investigation of the activation patterns revealed that mental processes involved are most likely task and stimulus dependent. By using a number magnitude comparison task we were able to replicate the activation pattern typically associated with number magnitude processing with manual responses for the case of mental decisions (for a review see ). This oAnother important aspect regarding validity of the current results may be the fact that the different tasks were presented in a fixed order. The rationale behind this ordering was to minimize a possible bias towards semantic processing of the presented stimuli in non-semantic tasks  by the fact that semantic magnitude information was critical in the preceding run. However, because passive listening was always presented prior to the parity task which was in turn followed by the magnitude comparison task we cannot and do not want to exclude that this might in turn have influenced the current results to some degree. In particular, one might speculate whether the observed lateralization for the parity task activation may have been influenced by presentation order. Although we cannot reject this possibility entirely, we are confident that left lateralization of the parity judgment task is not a mere artefact produced by the order of tasks but indeed adds to our knowledge about the specificities of processing different aspects of numerical information. In this context it is important to acknowledge that left lateralization of activation associated with language-based numerical information such as parity judgement has been reported only recently by Cappelletti and colleagues  and hasTaken together, the current paradigm seems to be a valid approach to further investigate the neural correlates of processing auditory number words with minimizing concurrent IPS activation due to processes of response selection/execution, hand/finger movement and/or associations with response codes. The implications of the current result will be evaluated in the following paragraphs.As repeatedly observed for number magnitude processing : When a voxel was activated for the passive listening task (requiring no response) and for e.g., the parity judgement task  it is very unlikely that the involvement of this particular area in the parity judgement task can be attributed to processes of response selection.In line with previous studies using visual presentation, the auditorily presented parity judgement task was associated with bilateral IPS activation  linguistically mediated is not totally new. At this point the linguistic Markedness Association of Response Codes (MARC) effect comes into play ; see als,24). WitThe current study presents a first step towards a more comprehensive understanding of the processing of auditorily presented number words leaving further steps to be taken. In particular, it would be desirable for future studies to investigate this issue by directly comparing the processing of visual and auditory input. Nevertheless, the results of the current study are meaningful as they indicate that activation of number magnitude information for auditory number words seems to be quite similar to activation typically reported for the processing of numerical stimuli. IPS activation commonly associated with number magnitude was observed in all conditions using numerical stimulus material: In particular, it was obtained not only in the semantic magnitude-relevant magnitude comparison task, as well as in the also numerical, but magnitude-irrelevant parity judgement task, but also in the passive listening task to number words in which no response selection was required at all. Contrarily, no intraparietal activation was observed when participants had to passively listen to pseudowords suggesting a highly automatic activation of number magnitude in humans for spoken number words similar to previous observations for visually presented numbers (see  for a reMore particularly, the present study provides a first systematic evaluation of the neural correlates and the interrelation of associated representations of numerical magnitude and parity information when stimuli are presented auditorily. First, bilateral activation of the IPS in both tasks indicated that the assumption of automatic activation of the magnitude of an encountered number generalized to auditory stimuli. Second, a left lateralized predominance within the IPS for the processing of magnitude irrelevant parity information for auditorily presented number words, as compared to a right lateralization for number magnitude, corroborates the notion that parity information may be represented in some kind of verbally mediated store for simple arithmetical properties. Finally, this left lateralization of the mental representation of parity information for auditory stimuli raises the question whether hemispheric asymmetries in numerical cognition may be more pronounced when stimuli are presented auditorily.The authors declare that they have no competing interests.KW and HCN conceived the study. All authors participated in its design. EK performed data collection, processing and statistical analyses. EK and KM drafted the manuscript; the other authors revised it critically. All authors contributed to the interpretation of the data. All authors read and approved the final manuscript.


Peripheral lymphocyte counts were performed on 41 patients with advanced breast cancer, before starting treatment with oestrogens or androgens. Patients were seen at monthly intervals, and the response to treatment was independently assessed, using the criteria of the British Breast Group. In the patients treated with oestrogens and androgens, the successful responders were found to have significantly higher pre-treatment peripheral lymphocyte counts than the intermediate responders and failures. It is suggested that pre-treatment peripheral lymphocyte counts may have a prognostic value in assessing potential response to hormone therapy in patients with breast cancer.


Repigmentation of vitiligo depends on available melanocytes from three possible sources: from the hair follicle unit which is the main provider of pigment cells, from the border of vitiligo lesions, and from unaffected melanocytes within depigmented areas; pigment cells at these locations originate a perifollicular, border spreading and a diffuse repigmentation pattern. In order for repigmentation to take place under stimulation with diverse therapies, melanocytes should be present in appropriate numbers. Melanocyte tissue stem cells located in the niche at the bulge region of the hair follicle are the most important sources for providing immature pigment cells that undergo terminal differentiation and originate repigmentation, but cytokines, UVR and other molecules acting in melanogenesis with adequate regulation mechanisms contribute to successful recovery in vitiligo. The presence of keratinocyte stem cells in the interfollicular epidermis raises the question on the possibility of melanocyte stem cells in a similar location and the development of future strategies for therapeutic purposes. In vitiligo, melanocytes are targeted by multiple aggressions leading to marked reduction of pigment cells and eventually to their complete destruction. In some Vitiligo recovery depends on a viable melanocyte reservoir and in many patients with vitiligo repigmentation is possible when pigment cells are stimulated with appropriate topical or oral medications. Nevertheless, when pigment cells are completely destroyed, melanocyte transplantation may the best therapeutic approach.In the following sections, the presence of pigment cells in the hair follicle and their relationship with vitiligo are discussed according to available evidence.Although the concept of melanocyte reservoir is mostly used to designate the hair follicle unit, melanocytes for repigmentation by medical methods arise from three main sources: (a) the hair follicle unit; (b) unaffected melanocytes within areas of depigmented epidermis, and (c) melanocytes located at the edge of vitiligo lesions. When stuIt is of special importance to emphasize that hair follicles are absent on palms, soles, mucosal or semi-mucosal surfaces and therefore these areas become particularly refractory to all therapies because the melanocyte reservoir is lacking; however, a diffuse repigmentation pattern is frequently observed, raising Vitiligo is a disease that was observed very early in history, and most ancient civilizations and religions had some type of reference about lack of pigmentation. One of t5595Many centuries went by and vitiligo continued to be one of the most important depigmentation ailments worldwide provoking discrimination or segregation in certain cultures, where affected individuals were unable to get jobs or even become married most proAfter the middle ages, around 1533 Andreas Vesalius called the attention about the skin having two layers. Several In summary, around 4000 years of known history elapsed from the time man became aware of disturbing white spots on the skin until the melanocyte was finally identified as the responsible actor for depigmentation and other pigmentary disorders.During the first half of the twentieth century, some progress was made in the areas of pigment cell morphology and function. However after 1950 until present, intensive research provided important information on melanocyte structure, gene characterization, physiology, physiopathology and bio-molecular characteristics, although the pathogenesis of vitiligo has not been completely elucidated; thereforet al., in 1979 who described the presence of DOPA negative, non-dendritic pigment cells along the external root sheath that migrated toward the basal cell layer to become functionally active in patients treated with PUVA for vitiligo.[et al., in 1991, when treatment in vitiligo patients stimulated inactive melanocytes in the middle and/or lower parts of hair follicles to proliferate and migrate along the outer root sheath to the nearby epidermis, where pigment cells expanded radially and were clinically observed as perifollicular repigmentation.[et al., in 1996 demonstrated immature dendritic, tyrosinase negative and c-kit positive pigment cells mainly concentrated around the follicular ostium, and to a lesser extent in the rete pegs and the outer root sheath,[During the second half of the twentieth century in 1959, Staricco RG showed amelanotic melanocytes in the external root sheath of hair follicles that suggested immature pigment cells. Further entation. In additentation. Later ont sheath, suggestiThe human hair follicle is a specialized skin appendage arising from epithelial-mesenchymal interactions beginning around the third month of embryonic development with the formation of the dermal papilla; further proliferation and differentiation of more than 20 different types of cells overlying the papilla initiate the hair follicle structure with six main compartments: the connective tissue sheath, the dermal papilla fibroblasts, the outer root sheath, the inner root sheath, the shaft and the sebaceous gland.The mature hair follicle consists of a morphologically permanent upper segment and a lower segment that remodels during hair cycling in which three phases are described: (a) anagen, where the growth phase occurs generating the hair shaft, the inner and outer root sheaths and the hair matrix; (b) catagen, with epithelial regression post apoptosis; and (c) telogen, a quiescent phase with resting cells.26In the bulbar region, multiple, dendritic, tyrosinase positive, large differentiated melanocytes located within the hair matrix provide melanin for hair shaft pigmentation. All of these anatomical structures constitute the pigmentary hair follicle unit bearing the melanocyte reservoir.Stem cells: Mammalian stem cells are divided in two categories: (1) Stem cells that may differentiate into all of the specialized embryonic tissues, and (2) Stem cells that are present in adult tissues and are capable of regenerating and maintain the normal tissue turnover and repair by providing new specialized and differentiated cells; these cells must be immature, slow cycling, self-maintaining and fully competent to regenerate progeny.–29Tissue-specific stem cells are usually found in a specialized environment within specific organs called the niche that provide important signals to guide their function and are the ability for indefinite self-renewal; some stem cells remain in the niche and others become a lineage-restricted transient amplifying cell or progenitor cell that leaves the niche and undergo several limited cycles of proliferation before transforming into differentiated cells; andthe capacity to differentiate into multi specialized cell lineages of the specific tissue.et al., in 2002 identified melanocyte stem cells in the lower permanent portion of Dct-lacZ transgenic mice hair follicles, which become activated at early anagen as they are tightly coupled to the hair regeneration cycle.[As mentioned, it is assumed that stem cells are maintained in a specific environment known as the niche. Nishimura on cycle. They areon cycle. The bulgon cycle.. In addion cycle.Recently, when studying hair follicles from normal human scalp skin with immunohistological staining techniques and quantitative histomorphometry, the bulge region was found as a site of relative immune privilege, protecting the hair follicle epithelial stem cell reservoir from autoaggressive immune attacks, a findinEven though hair follicles are absent in palmar skin, its repigmentation following NB UVB or PUVA in vitiligo raises t35Repigmentation arises mostly from hair follicle units wherever hair is available, but unaffected melanocytes may be present in vitiligo areas even many years after depigmentation takes place and thos4Hair pigmentation is provided by very active follicular melanocytes located above the dermal papilla. SynthesiThe regulation of melanogenesis is modulated by melanocortin 1 receptor, adrenocorticotropic hormone, melanocyte stimulating hormone, agouti protein ligands, c-Kit, and endothelin receptors. It is po42For repigmentation to occur, it is necessary that melanocytes become stimulated with appropriate signals. In this regard, two important properties of melanocytes have to be taken into consideration: (a) neo-melanogenesis, which implies melanin synthesis and production of melanosomes and b) melanocyte migration, which will help pigment cells to reach depigmented skin.in-vitro stimulation of pigment cells, several cytokines have been observed to have different effects: a) PGD2, LTB4, LTC4, LTD4, LTE4, thromboxane B2 and HETE produce increased dendricity, edema, higher levels of tyrosinase and immunoreactive b-locus;[During  b-locus;45 b) oth b-locus;47 some oIn addition, the SCF/KIT pathway plays a critical role in the control of normal human melanocyte homeostasis. It is coBoth UVA and NB UVB are potent melanocyte stimulants for repigmentation; sunlight overexposure with the full UV spectrum may induce marked pigmentation with diffuse skin darkening that depends on the intensity of UV light exposure.Immunosuppression: To stop melanocyte destruction after UVB irradiation T-regulatory (suppressor) cell activity is induced and released; IL10 may be important for the differentiation and activation of T-regulatory cells having suppressor autoimmune activity. A higherStimulation of growth factors: these molecules may be activated with UVR; this has been shown with UVR as the number of residual melanocytes increases most probably by enhancing melanocyte growth factors such as bFGF and ET-1.54vitiligo vulgaris melanocytes may become gradually destroyed leading to leukotrichia, although it is not correlated with disease activity.[The presence of pigmented hairs in vitiliginous skin is a good prognostic sign for vitiligo recovery speaking in favor of an intact melanocyte reservoir. Nevertheactivity.As leukotrichia represents melanocyte reservoir exhaustion , repigmeIn addition, leukotrichia may be distressing in certain anatomical areas and patients may request therapeutic advice; hair repigmentation may be accomplished as reported previously with epidermal grafts and thinVitiligo is a complex disease producing asymptomatic depigmentation but with a heavy psychological burden. Complete knowledge of its etiology has been elusive for decades of intense research; but during the past few years important findings started to shed light on its causes and pathogenesis of depigmentation. The complete knowledge of the melanocyte reservoir is of prime importance to understand the mechanisms of repigmentation, which are crucial for designing newer strategies for vitiligo therapy. The possibility of melanocyte stem cells in skin areas without hair follicles where repigmentation occurs with a diffuse pattern may suggest the existence of an amplified concept of the melanocyte reservoir that would include the interfollicular epidermis as well.


Sestrins are a                        family of stress-inducible proteins that can function as antioxidants and                        as inhibitors of target of rapamycin complex 1. In this                        research perspective, we discuss the possible roles of Sestrins in diverse                        stress-induced patho-physiological contexts that can result in premature                        aging and age-related diseases. We suggest that Sestrins provide critical                        feedback regulation that adjust metabolic and stress responses to different                        environmental cues and evolutionary constraints.                 The                        discovery of Sestrins as p53 targets ,2 suggesChronic                            exposure to genotoxic stress is known to accelerate aging, and mutations that                            disrupt proper DNA damage responses and interfere with DNA damage repair are                            associated with premature aging in humans . Many stAge-dependent                            accumulation of DNA damage can lead to cancer , one of Oxidative                            stress not only can interfere with the proper flow of genomic information by                            oxidizing DNA and RNA, but also can damage other macromolecules such as                            proteins and lipids . AccumulSestrins                            are transcriptionally induced upon oxidative stress , and areHypoxia                            is another environmental stimulus that can induce Sestrin gene transcription                            . SestrinIschemic                            injury to heart muscles and neurons, which is caused by hypoxia, is one of the                            major causes of death in elderly individuals . In an eHypoxic                            preconditioning can protect both heart and neuronal cells from severe ischemic                            injury-induced cellular damage ,45, but In                            addition to the important role that Sestrins play in mediating essential                            environmental inputs into metabolic regulation, these molecules may also play                            central roles in responding to other environmental cues such as nutrient                            supply, hydration status, temperature, chemical damage, and reproductive                            signals. One might speculate that because these various cues would have                            different impacts on different organisms, Sestrin genes should have evolved                            complex cis-regulatory regions to place them under distinct regulatory controls                            that vary from one organism to another. Indeed, our analysis of Sestrin genomic                            loci revealed that these sequences are rapidly evolving among the various                            Drosophila species. For example, the                            disposition and number of FoxO binding sites in the Sestrin locus vary                            significantly among species Figure . ComparaIn                            this research perspective, we briefly reviewed how Sestrins may act as                            suppressors of aging that are responsive to stressful stimuli and insults that                            can accelerate the aging process. By activating AMPK and inhibiting TORC1,                            Sestrins can reprogram cells to adapt to stressful conditions by attenuating                            anabolism and enhancing autophagic catabolism. Sestrins can suppress oxidative                            damage by acting as either antioxidants, inducers of autophagy that eliminate                            ROS-producing dysfunctioning mitochondria, or suppressors of ROS-producing                            mitochondrial metabolism. Therefore, we can view Sestrins as physiological brakes                            that can attenuate stress-dependent acceleration of aging Figure .       In                            addition, it is worth noting that Sestrins are also expressed under normal                            unstressed conditions ,2,4, andOver-nutrition                            and obesity can elevate the incidence and frequency of physiological insults by                            stimulating TORC1 activity , which iAlthough                            environmental stress generally accelerates aging, it should be considered that                            exposure to a low level of stress or stress adaptation can actually be                            beneficial for the organism, increasing life span and preventing age-associated                            degenerative diseases -56. The In                            summary, we suggest that Sestrins are uniquely poised at the crossroads between                            stress and aging to adjust the metabolic timbre of an organism to meet its                            needs under normal conditions and to respond to predictable forms of                            environmental stress.  Future experiments should shed light on the specific                            mechanisms by which the various effector functions of the Sestrins are                            achieved.


Liza Dawson and colleagues discuss the scientific and ethical issues associated with choosing clinical trial designs when there is no consensus on what constitutes usual care. Challenges often arise when researchers propose clinical trials incorporating usual care comparison groups.Disagreements may arise about current levels of evidence supporting usual care or failures to use best known methods in clinical practice; about the need for customized care, or about the difficulty in choosing best treatments when available interventions have trade-offs.Clinical trial designs incorporating usual care arms must be based on scientific validity, consideration of risks and benefits to patients, relevance to the clinical care community, and feasibility.In 2002, a clinical trial designed to evaluate optimal ventilation practice In November 2005, NIH and a number of other federal agencies sponsored a meeting see  to discuTerms such as “standard of care,” “control arm,” “usual care,” and “community care” have all been used to describe arms reflecting conventional therapy. We use the term “usual care” to describe the care commonly given by practitioners in a community to avoid any legal or normative implications of the term “standard of care.”There may be scientific, ethical, and/or practical reasons for having an arm in a clinical trial that employs usual care. If researchers hypothesize that a new intervention is better than or at least equivalent to current clinical practice, then one trial arm needs to reflect usual care. Ethically, the clinical care community must be in a state of equipoise prior to randomizing patients to different interventions Five types of difficulties can arise in defining a comparison group, and several of these conditions often coexist: (1) disputes about evidence; (2) low level of utilization of best methods; (3) trade-offs relating to physician and patient preferences for different treatments; (4) an insufficient preexisting evidence base to guide treatment selection; and (5) individually customized medical care for conditions with no standard practice guidelines.Underlying these issues are two fundamental tensions. First, there is tension between the need for control over experimental conditions and the need for trials to be relevant to clinical care in the community. This tension has been described as a distinction between pragmatic and explanatory trials Second, lack of consensus on the current evidence base confounds attempts to design new trials. Trials should build upon previous evidence and address gaps in knowledge, but achieving this goal depends upon some agreement among stakeholders about interpretation of the state of current evidence and priorities for research.Experts may disagree about interpretation of the available evidence and about whether current treatments have been validated by research . This laBefore taxanes were available, first-line treatment for advanced ovarian cancer consisted of carboplatin, either alone or in combination with other drugs. In the early 1990s, four large trials were undertaken to determine if the addition of taxanes could improve survival in patients with advanced disease Consequently, in an international collaboration involving the US, UK, and Canada, national differences in practice guidelines—based on divergent views of the evidence—led to disagreements about the appropriate reference arm in a trial adding newer drugs to existing regimens. In the trial, Gynecologic Oncology Group 182-International Collaborative Ovarian Neoplasm (ICON) 5 Designs that directly address the source of the evidentiary controversy are valuable, but it might be impossible to design a study that is acceptable to all. Experts may disagree about whether there is sufficient uncertainty to conduct a trial, or about the risk–benefit profile of any particular design. Some might believe that evidence already exists that a particular intervention is inferior or poses serious risks; others who believe that evidence is not clear might advocate for a trial to compare competing interventions.In these situations, the most important first step is to correctly identify the source of disagreement about evidence, which can then be a focus of discussion.Proven interventions may not be widely used The choice of research question and study design may depend on an analysis of the factors driving the low utilization. Disagreements can arise about whether a validated treatment that is not used in the community should be considered standard and provided to a control group in a trial . If usuaESPRIT was designed to determine the efficacy of a platelet glycoprotein (GP) receptor antagonist, eptifibatide (Integrilin) in reducing the incidence of various coronary events in percutaneous coronary intervention (PCI). During study planning there was a vigorous debate about whether the trial should be have a placebo or active control, namely abciximab The FDA challenged the placebo-controlled study design Where the prevailing practice is no treatment, investigators might consider a placebo control, but may be constrained by ethical demands for an active comparison group. There are existing guidelines for the use of placebos If researchers test a new intervention that could match the effectiveness of the gold standard but is cheaper, easier, or more accessible, it would be reasonable to use the best known method as a comparator in a noninferiority design. However, if the new method is likely to be inferior to the best known treatment but better than the usual care patients actually receive, a quandary remains: which existing method should be used as a comparator?Generally, noninferiority trials require greater numbers of subjects than do superiority trials, If a new intervention is compared to best methods, the feasibility of conducting the noninferiority trial might be a limiting factor in getting the research off the ground. A superiority trial using an inferior reference arm might be more feasible but objectionable because of the less than optimal comparison group. There is no consensus on how these situations should be handled.A trial might be designed as a strategy trial to test an intervention delivered according to a specific algorithm head-to-head against the same intervention as used in the community. The acceptability of this design might depend on whether the best-practices algorithm is widely considered more effective, or whether this is still an open question.An example of such a trial is the Hypertension Detection and Follow-up Program Two or more treatments for a single condition may be characterized by different profiles of performance across different measures or side effects. Regimens can be chosen on the basis not only of effectiveness but also side effects or quality of life The MTA While the main research question in MTA was not about the adequacy of usual care, the inclusion of the community care arm allowed some important data to be collected about the effectiveness of usual care practices compared to the intensive, carefully monitored interventions delivered in the other three trial arms. Detailed data collection on procedures in the usual care arm informed further work on translating the clinical trial results back into community practice When available treatments present trade-offs, patient preferences are often particularly relevant SPORT randomized patients to surgical versus nonsurgical treatments for back pain Often, treatments used in clinical practice have been insufficiently evaluated in rigorous clinical trials. This problem may occur with non-drug interventions or with drugs that have not been tested against relevant comparators. Clinical trial data may be scanty, of poor quality, or based on irrelevant patient populations; many treatments have not been systematically evaluated in randomized clinical trials (RCTs) Trials addressing these kinds of evidence gaps could be designed with multiple arms comparing existing interventions or comparing a single intervention to a heterogeneous group of treatments in the “usual care” arm.The principal problem with this flexible usual care group design is the limitations on inferences that may be drawn unless the single intervention is clearly superior. In noninferiority trials, inferences could be problematic if there is a lack of solid evidence supporting effectiveness of a usual care arm Selection of customized treatment based on physician assessment of individual patient characteristics Physician decision-making can be tested in a flexible usual care arm, although if physicians vary in their criteria for assigning individual treatments, it will be impossible to make inferences about which set of criteria is best. A preferable alternative is to test disease management algorithms versus usual practices The choice of comparison arms in clinical trials can be challenging when there is no clear-cut uniform standard of care. A variety of non-mutually exclusive factors can feed the lack of consensus: differing interpretations of existing evidence, inadequate evidence, different balancing of trade-offs, a failure or inability to implement evidence-based therapies, or a belief in customized care.It is critical to think systematically about the background conditions in the practicing medical community and goals of the trial when grappling with the complexities of heterogeneous medical practices. Multiple research questions could be important, each requiring a different trial design. At a minimum, the background conditions of medical practices and beliefs should be thoroughly explored, sometimes with qualitative as well as quantitative research.Potential trial designs should be examined based on the following criteria:Scientific validity and strength of inferences possible from a given design;Risks and benefits to participants in chosen design versus alternative designs;Relevance of the trial to current practice, including relevance to provider and patient beliefs and values;Feasibility of the trial.If a usual care arm is proposed, the scientific rationale for including such an arm should be carefully evaluated. It is critical to consider whether the usual care arm will contribute to meaningful inferences about the relative merits of different interventions in the trial, and whether the protocol should restrict or intervene in usual care. Design choices regarding protocolized versus unrestricted usual care often involve navigating a tension between the need for rigor and clarity of evidence versus practicality and relevance to clinical practice.If less than best accepted medical care is provided in a trial arm it must be carefully evaluated and justified. When there are disputes about the adequacy of, or evidence base for, any of the interventions proposed for the trial, there may be no consensus on whether trial participants are adequately protected—these disagreements about evidence should be frankly acknowledged.The relevance of the trial to current practice should be described. Finally, practical limitations should be acknowledged, including infrastructure, costs, willingness to participate, time constraints, or other factors.Not all “usual care” trials have similar purposes. The SPORT trial  defines On the other end of the spectrum is the ovarian cancer trial, in which a dispute about the appropriate comparator was resolved with a choice of one treatment that was not yet universally used, but was viewed by some as best proven therapy. Such trials pose no problems of interpretability. Trials that occupy an intermediate category are those that use multiple arms that implement different therapeutic approaches used in practice, but that share a common mechanism, such as different degree of the same therapy. In such trials, the pattern of results among the arms becomes relevant, as either a flat or monotonic dose–response is expected. The arms therefore “borrow strength” from each other in ways that mechanistically heterogeneous treatment choices or combinations cannot.Choices of control or comparator conditions can become surrogates for debates about the adequacy of current medical practice, about current scientific evidence, or about assessment of trade-offs among treatment options. These debates can affect judgments about whether sufficient uncertainty exists to conduct the trial at all; whether risks to subjects are minimized; and whether the trial data will be interpretable. Disputes about background conditions complicate these already difficult discussions, and new empirical data on practice patterns can help clarify such debates. What is critical in all of these situations is that the reasons for disagreement about usual care be recognized and addressed separately from the question of the trial design.The goal should be that each trial will contribute to the accumulation of knowledge via a sequence of investigations, which together lead to a causally coherent understanding of treatment effects. Ultimately, we want to answer why a treatment is effective, by how much versus a defined comparator, at what risk, and in which patients. So an investigator must be able to look beyond the trial in question and explain how its results will inform future research that lead to such an understanding. Studies implementing “usual care” arms can complicate this task, but if done right can ultimately lead to results of great scientific relevance and practical value.Text S1http://crpac.od.nih.gov/Draft_UsualCareProc_06062006_cvr.pdf.Considering usual medical care in clinical trial design: Scientific and Ethical Issues Meeting, November 2005, Bethesda, Maryland. In November 2005, NIH and a number of other federal agencies sponsored a meeting to discuss clinical trial design challenges involving selection of usual care comparison groups. The planning committee for the meeting consisted of the following individuals: Duane Alexander, NIH/NICHD; Jonathan Berman, NIH/NCCAM; Carolyn Clancy, AHRQ; Ezekiel Emanuel, NIH/Clinical Center; Ellen Feigal, NIH/NCI; Lawrence Friedman, NIH/NHLBI; John Gallin, NIH/Clinical Center; Saul Malozowski, NIH/NIDDK; Peter Mannon, NIH/NIAID; Joan McGowan, NIH/NIAMS; Amy Patterson, NIH/OD; Marcel Salive, CMS; Bernard Schwetz, OHRP; Belinda Seto, NIH/OER; David Shore, NIH/NIMH; Lana Skirboll, NIH/OD; Robert J. Temple, FDA; Deborah Zarin, AHRQ. The meeting was informed by a background paper outlining types of challenges involved in selecting usual care arms, prepared by a working group with expertise in clinical trial design, ethics, evidence-based medicine, statistics, and science policy. The drafting group for the background paper consisted of Liza Dawson, Ezekiel Emanuel, Lawrence Friedman, Steven Goodman, and Deborah Zarin. At the meeting, case study presentations were made by Taylor Thompson, Mass. General Hospital, Acute Respiratory Distress Syndrome Network (ARDSnet); Ann Marie Swart, UK Medical Research Council, International Collaborative Ovarian Neoplasm (ICON) Trials; James Swanson, UC Irvine, Multimodal Treatment Study of ADHD (MTA); James Weinstein, Dartmouth Medical School, Spine Patient Outcomes Research Trial (SPORT). A full presentation of each case study and panel discussion is included in the meeting proceedings document at (0.03 MB DOC)Click here for additional data file.


Furthermore, in adult humans, and monkeys with orthologous genetic polymorphisms, there is no observable correlation between these functional genetic variants and the amount or activity of the corresponding proteins in the brain. These seemingly contradictory data might be explained if the association between serotonin and these behavioural and psychiatric conditions were mainly a consequence of events taking place during foetal and neonatal brain development. In this review we explore, based on recent research, the hypothesis that the dual role of serotonin as a neurotransmitter and a neurotrophic factor has a significant impact on behaviour and risk for neuropsychiatric disorders through altered development of limbic neurocircuitry involved in emotional processing, and development of the serotonergic neurons, during early brain development.Brain monoamines, and serotonin in particular, have repeatedly been shown to be linked to different psychiatric conditions such as depression, anxiety, antisocial behaviour, and dependence. Many studies have implicated genetic variability in the genes encoding monoamine oxidase A (MAOA) and the serotonin transporter (5HTT) in modulating susceptibility to these conditions. Paradoxically, the risk variants of these genes have been shown,  Both genes encoding these proteins harbour genetic polymorphisms in their promoter regions that have been shown, activity –8. Theseactivity –15. The S  and L . The L-allele has further been shown to encompass a single nucleotide polymorphism (SNP rs25531) that affects a putative transcription factor binding site and renders the LG-variant functionally equivalent to the S-allele (Macaca mulatta) has been shown to contain an orthologous polymorphism in the serotonin transporter gene that has also been shown to have a functional effect on transcriptional activity , for either 5HTT  has been shown to be a unique marker for these cells ,44. In PA well characterized rodent brain region that displays anatomical alterations in response to elevated serotonin levels during development is the somatosensory cortex, which, in humans as well as rodents, has a well defined cytoarchitecture, corresponding to the afferent sensory projections from different areas of the body. Specifically the barrel fields in rodents, innervated by thalamocortical afferent neurons emanating from the whiskers, have been extensively studied due to the clear anatomical representation of barrel-like structures corresponding to individual snout whiskers in rodents . NumeroIn vivo functional studies of the human brain, using functional magnetic resonance imaging (fMRI), have provided important clues to which specific brain regions and functional connections between these that display serotonin-dependent activity differences . The neAlthough much of the discussion above focuses on the role of serotonin during brain development and the behavioural consequences, it also has an evident role in shaping mood and behaviour in adulthood. Two well studied experimental paradigms for exploring phenotypic effects of altered serotonin levels in adulthood are ‘tryptophan depletion’ and ‘tryptophan challenge’ . These mBrain structures involved in emotional regulation form the neuronal foundation for how we respond to external stimuli. Above, we have outlined how serotonin could be involved in modulating some of these neurocircuits with apparent consequences for shaping of different aspects of behaviour. From this follows that genetic variability leading to altered serotonergic neurotransmission will have an impact on how individuals interpret and respond to environmental cues, such as stressful or fearful stimuli for example. However, emotional processing in this sense is not a unilateral event, determined only by the shape and activity in these neuronal circuits. In a famous study by Caspi et al., it was shown that the phenotypic outcome was modulated through an interplay between environmental insult and genetic factors . In a saSerotonin has been shown to be an important factor in regulating the neuro-development of brain regions critical for emotional processing. In animal models, dysregulation of serotonin during these early neuro-developmental stages have revealed behavioural outcomes with important parallels to human neuropsychiatric disorders. Functional genetic variability in the genes for MAOA and 5HTT has been firmly associated with anatomical and functional differences in the limbic system in humans, in the absence of an association to availability or activity of the corresponding proteins, arguing for an effect of these genetic factors during brain development. Furthermore, the functional genetic variants of MAOA and 5HTT have been shown to modulate the impact of environmental factors on behavioural traits, in terms of gene–environment interactions, which in many cases display apparent sex differences. It also appears as if these interactions are reciprocal at early ages, in the sense that genetic factors regulating serotonin levels result in developmental alterations to specific neurocircuits involved in emotional processing, causing different responses to external stimuli, which has been observed to have an effect on serotonergic neurotransmission, further affecting on-going neuronal development. Future studies on the causal mechanisms behind the role of serotonin during brain development will hopefully provide knowledge, not only of how the neurocircuits involved in emotional processing work, but also give an improved understanding of the biological aetiology for neuropsychiatric disorders.


Geneticists have long known that centromeres suppress crossing over, but considerable evidence indicates that they appear to recombine. Confirmation of gene conversion in maize centromeres explains this paradox. A long-standing problem in chromosome biology concerns the dynamic nature of centromeres. These chromosomal sites assemble the protein machines called kinetochores that connect chromosomes to the spindle microtubules for segregation to daughter cells during mitosis and meiosis. In multicelluar eukaryotes, centromeres are typically composed of highly homogeneous tandem repeats that evolve rapidly despite their highly conserved function Centromeres do not act alone in orchestrating chromosome segregation. In order for sister kinetochores to properly disjoin (separate) and segregate chromosomes equally to daughter cells in mitosis, their sister chromatids must be linked so that the pulling forces from the two halves of the spindle generate tension to correctly orient the kinetochores, stabilize kinetochore attachments, and signal that kinetochores are ready to disjoin. Centromeres in multicellular eukaryotes are typically embedded in heterochromatin, the permanently condensed chromatin found around centromeres, in contrast to the euchromatic chromosome arms, which decondense between mitoses. Heterochromatin has been implicated in facilitating cohesion of sister chromatids around the centromere. This cohesion is mediated by cohesins, proteins that link the sisters together and that are enriched around centromeres Drosophila melanogaster soon afterward As early as 1930, observations on the distribution of chiasmata along chromosomes led Karl Sax to predict that crossing over (and hence genetic recombination) is reduced around the centromere DrosophilaSaccharomyces cerevisiae) Why is crossing over suppressed around centromeres? In Drosophila X chromosome and suggested that the centromere can suppress recombination independently of its flanking heterochromatin Drosophila mutants that affect heterochromatin structure support the role of heterochromatin in suppressing pericentric crossovers Arabidopsis thaliana, crossing over is reduced >200-fold in the 2.3-Mb centromere region of Chromosome I, and 10–50 fold by the 1-Mb heterochromatic flanking regions How is crossing over suppressed at centromeres? The location of centromeres in heterochromatin raises the possibility that the crossover suppression seen at the centromere may simply be a property of the surrounding heterochromatin. Early attempts to separate heterochromatin from the centromere utilized inversions of pericentric heterochromatin on the At the molecular level, centromeres are distinguished from both heterochromatin and euchromatin by specialized nucleosomes containing the centromere-specific histone H3 variant known as CENP-A or CenH3, which is necessary to form the kinetochore. Occasionally functional CenH3-containing centromeres can arise on DNA that was previously non-centromeric and be faithfully transmitted (neocentromeres), indicating that centromere inheritance is epigenetic, dependent on the presence of CenH3 nucleosomes, not on specific DNA sequences (reviewed in Oryza sativa), which has only very little satellite DNA, lacks detectable crossovers in a 2.3-Mb span around the 750-kb centromere region that contains discontinuous blocks of CenH3-containing nucleosomes. Remarkably, there is little difference in gene activity, transposon composition, or abundance of common histone modifications between this recombination-free region and adjacent recombining regions Although both centromeres and pericentric heterochromatin are rich in repetitive elements, repeats per se do not appear to be necessary for crossover suppression. For example, centromere 8 of rice  chromosomes and is negatively regulated by DNA methylation, without which loss of repeats occurs Although crossing over is suppressed around centromeres, the tandem satellite array structure that is typical for most centromeres is best explained by extensive and repeated recombination. The generation of such arrays has been modeled as a recombinational process of random unequal exchange In the same year that Sax predicted the centromere effect on crossing over, a new model of recombination, called gene conversion, was proposed to explain non-reciprocal recombination events in mosses and basidiomycetes The localized nature of gene conversion makes it significantly more difficult to detect than crossing over. A key problem is the need for numerous closely spaced unique markers in the highly repetitive sequences of the centromere and pericentromere. Consequently this question has been most thoroughly addressed in budding yeast, which lacks centromeric and pericentric repeats. Most studies have concluded that gene conversion is moderately suppressed (4- to 7-fold) at yeast centromeres, along with crossing over Zea mays). They developed 238 centromeric markers based on insertion polymorphisms of the centromere-specific transposon CRM2 that map to all ten maize centromeres. To verify their centromeric location, centromeric chromatin was immunoprecipitated with an anti-CenH3 antibody. CenH3 is distributed discontinuously in maize centromeres To determine whether gene conversion events can occur within large centromeres and provide the recombination events underlying both satellite homogenization and centromere diversity, a new report by Shi et al. −5 conversions per marker per generation, a rate not dissimilar to one estimate for the conversion rate on the chromosome arms Shi et al. then proceeded to assess their marker set in 53 highly diverse inbred lines representing the diversity of maize and found widespread evidence for marker recombination since the origin of maize, perhaps 9,000 years ago These results are significant both for understanding the regulation of recombination in maize and for understanding the evolution of centromeres. Except in yeasts, studying recombination in centromeres has hitherto been largely a matter of inferring the occurrence of ancient events based on present-day sequences. The results of Shi et al. show that it is possible to study centromeric recombination in action in a multicellular eukaryote. They also confirm that such recombination can take place between homologs and not solely between sisters, with implications for the creation and spread of new centromere variants. Meiotic recombination involves complete end-to-end pairing of homologs, whereas a gene conversion event requires only a local homologous interaction, and it is possible that the observed conversion events occurred during mitotic development rather than during meiosis . For exaWidespread gene conversion might be a general feature of centromeres of multicellular eukaryotes. Human centromeres are composed of higher-order alpha satellite repeat arrays


Organismal phylogeny depends on cell division, stasis, mutational divergence, cell mergers (by sex or symbiogenesis), lateral gene transfer and death. The tree of life is a useful metaphor for organismal genealogical history provided we recognize that branches sometimes fuse. Hennigian cladistics emphasizes only lineage splitting, ignoring most other major phylogenetic processes. Though methodologically useful it has been conceptually confusing and harmed taxonomy, especially in mistakenly opposing ancestral (paraphyletic) taxa. The history of life involved about 10 really major innovations in cell structure. In membrane topology, there were five successive kinds of cell: (i) negibacteria, with two bounding membranes, (ii) unibacteria, with one bounding and no internal membranes, (iii) eukaryotes with endomembranes and mitochondria, (iv) plants with chloroplasts and (v) finally, chromists with plastids inside the rough endoplasmic reticulum. Membrane chemistry divides negibacteria into the more advanced Glycobacteria (e.g. Cyanobacteria and Proteobacteria) with outer membrane lipolysaccharide and primitive Eobacteria without lipopolysaccharide (deserving intenser study). It also divides unibacteria into posibacteria, ancestors of eukaryotes, and archaebacteria—the sisters (not ancestors) of eukaryotes and the youngest bacterial phylum. Anaerobic eobacteria, oxygenic cyanobacteria, desiccation-resistant posibacteria and finally neomura (eukaryotes plus archaebacteria) successively transformed Earth. Accidents and organizational constraints are as important as adaptiveness in body plan evolution. Currently, we are in the early stages of a paradigm shift in which the prevailing view on these matters should be replaced by a sounder one. This review summarizes recent insights into bacterial and protozoan large-scale evolution and the tree of life for non-specialists and argues that much more intense research into the little-known phylum Chlorobacteria is needed for better understanding the nature of our last common ancestor. To avoid burdening you with excessive detail, I do this rather briefly in the second half of this essay, giving references to specialist literature for those wanting more detail or evidence for my conclusions.The first half is a broader historical/philosophical discussion of the contrast between ancestral and derived groups and how taxonomists should handle them. The past three decades have seen a dramatic increase in the use of DNA sequences for reconstructing phylogeny and a parallel shift in emphasis from evolutionary taxonomy  towards Micrographia in which Soon after it was founded, the Royal Society published Though I shall not dwell on it, another limitation of Weismann's synthesis has become apparent in the past two decades. Superimposed on the vertical inheritance of cell lineages that Weismann recognized is the horizontal transfer of individual genes or small clusters of genes among organisms of separate cell lineages, which can affect the evolution of extremely distantly related organisms. In bacteria, such lateral gene transfer (LGT) occurs mainly by viruses, plasmids or the uptake of naked DNA from dead cells. In eukaryotes, feeding by phagocytosis followed by inefficient digestion of prey DNA and its accidental incorporation into nuclear chromosomes is probably how protozoa most often get foreign genes . Althoug2.Shall we conjecture that one and the same kind of living filaments is and has been the cause of all organic life?, p. 507The nucleated vesicle, the fundamental form of all organization, we must regard as the meeting point between the inorganic and the organic—the end of the mineral and beginning of the animal and vegetable kingdoms … We have already seen that this nucleated vesicle is itself a type of mature and independent being in the infusory animalcule [now called Protozoa, following .Nonetheless, the distinction between a terminal branch of the evolutionary tree (a clade), e.g. animal or fungal kingdoms, and a basal, ancestral segment of the tree, e.g. Protozoa or Bacteria , is important, especially when discussing extinction and origin of groups. Monophyly and polyphyly were invented to clarify origins; distinguishing between paraphyly and holophyly has nothing to do with the origin of a group, but with how taxonomists cut up the continuous phylogenetic tree into discrete named units. The phrase ‘paraphyletic origin’ that one sometimes sees is conceptual nonsense. This controversy is much more fundamental and broadly biologically important than a mere difference in preferred nomenclature. It reflects a pervasive difference in philosophy; excluding ancestral groups from the concept of monophyly perverts Haeckel's evolutionary definition. I agree with Phytophthora infestans that caused the 1844 Irish potato famine, were considered fungi, being included in kingdom Fungi in Developayella in the heterokont phylum Pseudofungi (Let me illustrate the importance of distinguishing polyphyly and paraphyly by considering the case of Fungi and Pseudofungi in relation to udofungi . Celluloa). His implication that distinguishing paraphyly and polyphyly is therefore unimportant for systematics or arbitrary does not remotely follow; it merely underlines the casual neglect of actual ancestors and their phenotypes, and differing degrees of phenotypic change generally, by Hennigian cladistic philosophy. There being in these instances a shared common ancestor between a paraphyletic and a polyphyletic group does not nullify the importance of the distinction, which depends entirely on the historical phenotypes along the stems of the phylogenetic tree  group like Protozoa evolved once only and were inherited continuously from a common ancestry, making their similarity much more fundamental and unified. The naked phagotrophic lifestyle and often flagellate and/or amoeboid motility of most members of kingdom Protozoa evolved once only in their last common ancestor, as part of an extremely complex set of over 60 major innovations, the most radical in the history of life b. Thus, figure 2b). One cannot emphasize too strongly that a Hennigian cladogram is not a phylogenetic tree; cladograms have no ancestors, only extant species. Sequence trees are also not phylogenetic trees of organisms, being agnostic about ancestral phenotypes. figure 2Do not misinterpret me as claiming that the distinction between the two types of monophyly (paraphyly and holophyly) is unimportant. For some purposes it may be, but in two situations the distinction is crucial: when discussing extinction or origins.It is well known that discussions of group extinction must distinguish between real extinction of a holophyletic group such as trilobites, which genuinely left no descendants, and pseudoextinction of a paraphyletic group such as dinosaurs, which left descendants (birds) that differ so greatly from the ancestral group that they are not classified within it.It is less widely appreciated that when considering origins or reconstructing ancestral characters treating a paraphyletic group as holophyletic causes even more serious misinterpretations. Most papers discussing the nature of the ancestral cell make this very mistake by treating eubacteria as holophyletic, whereas they are almost certainly paraphyletic (see §§7–9). As To avoid such misinterpretation of paraphyletic groups, we need not abolish them; it is sufficient to flag them as paraphyletic (if we know that) and to teach biologists to use phylogenies directly, not classifications, for evolutionary reasoning about origins and extinction.6.The amount of modification which the different groups have undergone has to be expressed by ranking them under different so-called genera, subfamilies, families, sections, orders and classes., p. 352The evolutionary unreality of Hennig's antipathy to ancestral taxa is highlighted by allopolyploidy, by the nature of bacteria and by symbiogenesis.Spartina anglica, Primula kewensis; Allopolyploidy involves lineage fusion that is beyond the scope of cladistics, which unrealistically assumes only divergence. The view of Linnaeus and Erasmus Developayella, Cafeteria and many Cercozoa; the giant pseudopodial ‘heliozoan’ Actinosphaerium; the whole infrakingdom Rhizaria ancestrally characterized by net-like pseudopodia and the centrohelid heliozoa; see Blastocystis, a walled anaerobic human gut parasite , ignoring and contradicted by all three modes of horizontal evolution that make the true universal phylogeny a reticulating net, not an ever diverging tree ; if we remember that branches of real trees sometimes fuse, tree metaphors are useful.species itself classified within the group in question as its first species  all animals sponges; logically consistent cladists of that sort must accept that they are bacteria. If not, they should accept that such nomenclatural dogmas are deeply flawed, harmful to biology and abandon them forthwith. A philosophy that evades the reality of ancestors and denies the validity of ancestral groups is wrongly called ‘phylogenetic systematics’.Origin diagram was a proper phylogenetic tree with labelled ancestors, some explicitly called parent genera, not a cladogram. He would surely consider banning paraphyletic taxa an absurd impediment to evolutionary discussion and comprehensive classifications that include fossils and ancestors . Archaebacteria are sisters to eukaryotes  or bacteriochlorophyll . Their inner bounding membrane is homologous with and ancestral to the bounding membrane of unibacteria and eukaryotes, having typical acyl ester phospholipids (except in Chlorobacteria) as in eukaryotes and Posibacteria and related membrane proteins. Their outer membrane (OM) has more variable chemistry, the basis for classification into two infrakingdoms: Eobacteria and Glycobacteria c. The glβ-barrel proteins called porins that allow nutrient uptake from the environment. Their OMs uniquely have other macromolecular complexes mediating exchanges of larger molecules across it. All photosynthetic bacteria except Chlorobacteria are glycobacteria. In Eobacteria (comprising Chlorobacteria and Hadobacteria), the OM is simpler, with lipolysaccharide absent; Eobacteria have glycolipids based on long-chain diols instead of glycerolipids . Ancestors of Hadobacteria, and of the purely heterotrophic glycobacterial phyla Spirochaetae and Planctobacteria, must have lost photosynthesis. Photosynthesis was also lost on several occasions within the holophyletic Chlorobacteria, Proteobacteria, Sphingobacteria and the paraphyletic Eurybacteria, arguably the ancestors of the non-photosynthetic Posibacteria , the OM lipolysaccharide was lost, being replaced by host phosphatidylcholine, but porins remained, some even being recruited for the novel protein-import machinery that made these enslaved bacteria integrated organelles. Porins are β-barrel proteins, a class of proteins absent from all membranes except the negibacterial OM and these two organelle OMs. Chlorobacteria are the only negibacteria that lack porins or other β-barrel OM proteins; they are therefore considered the most primitive form of cell and most ancient ancestral type of negibacteria, because one can rule out the alternative idea of secondary simplification by loss of β-barrel OM proteins because loss of ability to insert them is lethal  absent in the clade (unimembrana) derived from it, which shares only the absence of the OM. As for Bacteria, this refutes cladistic dogma that paraphyletic groups are inadmissible because they necessarily lack positive traits that unify them.8.Many who use only RNA and protein sequences to interpret organismal history overlook the importance of the unique dramatic evolutionary transitions in cell structure in figures 9.An anaerobic phase in which photosynthetic non-sulphur bacteria (and before them extinct stem negibacteria) were the major primary producers for ecosystems. The major consumers with surviving descendants were heterotrophic chlorobacteria, and perhaps also Hadobacteria if they preceded the origin of photosystem II. Exclusively anaerobic life probably persisted for roughly a billion years  in which cyanobacteria were the major primary producers and dominant morphological fossils. However, very extensive anaerobic habitats probably remained, especially in the deep ocean. In the later part of this period, there are convincing body fossils of diverse cyanobacteria, including complex filamentous forms, some with heterocysts for fixing nitrogen . In the past, some of the largest microfossils from this part of the middle Proterozoic have been attributed to eukaryotic algae; more recently many have been instead assigned to the fungi or (more plausibly in my view) to a mixture of complex Cyanobacteria and of the Posibacteria that display the greatest morphological complexity: the actinomycete Actinobacteria (bacteria c. PossibThe age of eukaryotes and obvious macroorganisms (850–800 Myr ago to the present). Protozoa became the major predators on bacteria in water and wet earth; typically brownish photophagotrophic and photosynthetic chromists conquered the oceans; a green alga became a land plant 400 Myr ago, its descendants coating the continents where not too dry or cold with a green veneer providing homes and food for descendants of mobile animals (bilateria) that evolved 530 Myr ago via Cnidaria from marine sponges that fed on bacteria, like their choanoflagellate protozoan ancestors  only after over three-quarters of the history of life was already over. This late origin of eukaryotes is attributable to the lateness of the immediately preceding neomuran revolution, during which bacterial secretion mechanisms and cell wall chemistry radically changed, allowing for the first time enough cell surface flexibility for evolution of phagocytosis of other cells. The inherent difficulty and improbability of the neomuran revolution, rather than the succeeding changes that made eukaryotes, probably accounts for the lateness of their origin and that of brainy life during the Cambrian explosion as a result of the origin of the anus and continuous flow processing of food a.It is no longer phylogenetically acceptable to assume that methanogenic archaebacteria existed in the Archaean age of anaerobic life and that their biogenic methane saved the Archaean world from global freezing. Either there was a now-extinct group of negibacteria that could make methane or, more likely, a mixture of carbon dioxide, water vapour and abiogenic methane were the major greenhouse gases maintaining climatic stability. Oxidative removal of abiogenic methane by the origin of oxygenic photosynthesis approximately 2.5 Gyr ago probably precipitated the Palaeoproterozoic global freezing approximately 2.3–2.4 Gyr ago . ConversThe idea of Weismann and Wallace that asexual non-recombining organisms cannot evolve is wrong. Evolution in phases 1–3 was clonal: asexual cell lineages diverged without ever fusing. Some gene exchange occurred by viruses and in some groups by infectious plasmids or incidentally via food DNA  to evolve greater complexity despite mutations in every part of every gene in every generation for over three billion years, roughly a trillion generations—such is the power of constructional constraints and stabilizing selection to prevent radical evolutionary change. They enable ancestral (paraphyletic) groups to retain phenotypic coherence and validity as taxa, despite the occasional relatively rare origin from them of new body plans, themselves mostly stable for hundreds of millions of years. By my counting, fewer than 60 phyla evolved in the history of life . ProbablThe origin, substituted the divergent tree model for linear progress, and argued that major new adaptive types could originate and radiate extremely rapidly compared with the generality of evolutionary change. Examples of touching faith in the uniformity of evolutionary rates include the false supposition that cryptomonads independently enslaved a red alga much more recently than other chromists, because they alone retain the red algal nucleus as a nucleomorph  can become fixed as phylogenetic constraints. Thus, adaptations for phagotrophy almost certainly played a key role in initiating eukaryogenesis, but the endomembrane system, cytoskeleton and mitosis that evolved as a result of historical accidents and the inner logic of recovery from the associated disruptions b persistAs always, 12.Dehalococcoides) anaerobically respire chlorinated hydrocarbons as food, playing a crucial role in their natural detoxification (According to my recent analyses, Chlorobacteria are the most primitive extant cells (Cavalier-Smith fication ; might oThermomicrobium from other negibacterial phyla by lacking glycerophospholipids (Chloroflexus (Thermus possesses both phospholipids and glyceroglycolipids (Membrane chemistry differs in the non-photosynthetic chlorobacterium roflexus , and unucolipids . A phylo