There is limited evidence on adherence to the recommended dose and duration of zinc supplementation for diarrheal episodes in children under five years of age. In selected districts of Uttar Pradesh, India, we sought to assess adherence to the nationally advised zinc treatment regimen  among caregivers of zinc–prescribed children.We identified and conducted follow–up visits to children advised zinc for the treatment of diarrhea. At the initial visit, we collected data on the treatment instructions received from providers. Caregivers were asked to record treatments administered on a pictorial tracking form and were asked to retain all packaging for collection at follow–up. We quantified the average dose and duration of zinc therapy and built logistic regression models to assess the factors associated with caregiver adherence to national guidelines.Caregivers administered zinc for an average of 10.7 days (standard deviation (SD) = 3.9 days; median = 13 days), and 47.8% continued treatment for the complete 14 days. Among children receiving zinc syrups and tablets respectively, the age appropriate dose was received by 30.8% and 67.3%. Adherence to age appropriate dose and continuation of zinc for 14 days were highly associated with having received appropriate provider instructions.Our results indicate moderate–to–good adherence to national zinc treatment guidelines for diarrhea among caregivers in rural India. Our findings also highlight the importance of provider guidance in ensuring adherence to zinc dose and duration. Programs aiming to scale–up zinc treatment for childhood diarrhea should train providers to successfully communicate dosing instructions to caregivers, while also addressing the tendency of caregivers to terminate treatment once a child appears to have recovered from an acute diarrheal episode. The efficacy and effectiveness of therapeutic zinc supplementation in reducing the duration and severity of diarrhea among children under five years of age has been well–documented -3. In reIn addition to concerns regarding access to zinc treatment for diarrhea among children under–five years of age, studies assessing adherence to the advised dose and duration of supplementation have called into question the quality of the regimen received by those actually treated with zinc -14. A clEvidence from observational studies suggests that in practice adherence to the zinc treatment guidelines may be less common among both providers and caregivers. In a 2005 evaluation of the Scaling up zinc for young children (SUZY) project, only 55.8% adhered to the advised 10–day duration of treatment, and the average zinc–treated child received zinc for 7–8 days in total . A crossThough there are limited studies assessing the issue of adherence to therapeutic zinc supplementation for diarrhea, the existing evidence highlights important research questions that should be addressed as the global community pushes toward the goal of scaling–up adequate diarrhea treatment. Evaluations of newly implemented diarrhea treatment programs should therefore be designed to not only gauge zinc coverage but also the level of adherence to the zinc treatment protocol among both providers and caregivers of children under–five. While coverage surveys capture the proportion of children with diarrhea who receive any course of zinc, it is possible that very minimal zinc treatment regimens do not confer the same benefits as the advised course. Therefore, the level of zinc adherence may affect the extent to which increases in coverage translate into impact on diarrhea morbidity and mortality outcomes in the long–term. Furthermore, monitoring adherence to zinc dosage instructions is important, since ingesting more than the age appropriate daily dose may pose a risk for zinc toxicity.In an effort to address the question of zinc treatment adherence among caregivers of zinc–prescribed children under–five in rural India, we nested a sub–study within the external evaluation of the Diarrhea Alleviation through Zinc and ORS Treatment (DAZT) project in Uttar Pradesh (UP), India. To our knowledge, this is the first observational study to assess adherence to therapeutic zinc supplementation in rural India.The DAZT project was conducted in selected districts of UP from 2011–2014 with the goal of scaling–up ORS and zinc treatment of diarrhea among children 2–59 months of age. A complete description of the intervention and evaluation results are published elsewhere . In brieThe zinc adherence sub–study was designed to address the dearth of information on zinc treatment adherence among caregivers in rural India. Our main objective was three–fold: to estimate the proportion of caregivers who received zinc dose and duration instructions in agreement with national childhood diarrhea treatment guidelines; to estimate the proportion of caregivers that adhered to the course of zinc therapy advised by their child’s provider; and to quantify the average zinc treatment dose and duration received by children in this population. The study was conducted from May through July, 2014 in the Lucknow and Mohanlal Ganj tehsils of Lucknow district and the Badaun and Bisauli tehsils of Badaun district in UP.In the absence of published estimates of zinc adherence in rural India, we employed the most conservative methodology and assumed the true proportion of adherent zinc–treated children to be 50%; this approach maximizes the sample size requirements and was the most appropriate given our limited knowledge on the outcome of interest in this population. We used Stata 12.0 statistical software to calculate the sample size required to generate a precision estimate of the point prevalence of adherent zinc–treated children within 10 percentage points with 95% confidence . The resIn each tehsil, we randomly selected 12 rural villages for inclusion in the study using probability proportional to size (PPS) sampling. Trained interviewers visited all households within the selected villages to identify children meeting the following inclusion criteria: 1) aged 2–59 months; 2) episode of diarrhea (defined as ≥3 loose or watery stools in a 24–hour period) in the 7 days preceding the household visit; 3) receipt of zinc treatment for diarrhea in the 3 days preceding the visit. To ensure the accuracy of zinc reporting, interviewers verified the third enrollment criterion by asking to see any available treatments or packaging from treatments administered to the child. If more than one child in the 2–59 month age range resided in the household, the primary caregiver was instructed to base her responses on the youngest. Consenting primary caregivers of zinc–treated children were formally interviewed regarding the place of zinc procurement, zinc treatment instructions received, and the dose/duration of treatment to date.Interviewers scheduled follow–up visits for 14 days after the initial visit to all households in which a child met the inclusion criteria. The caregiver was asked to retain the packaging from any treatments administered to the child during this period and was also shown how to use a pictorial tracking form to record days on which the child experienced diarrhea and days on which the child was administered ORS and/or zinc syrup or tablets. The tracking form also included slots in which to record common daily activities  such that dummy variables could be generated to assess caregivers’ understanding of the tracking process. To reduce the threat of caregivers modifying their adherence behavior due to the scheduled follow–up visit, they were told that the purpose of the tracking form and visit was to check on the child’s well–being following the diarrheal episode.During the follow–up visit, the interviewer administered questions on the child’s diarrheal episode and treatments given during the preceding 14 days and confirmed the caregiver’s responses by referring to the tracking form and all reserved packaging. Interviewers also questioned caregivers regarding diarrhea treatment preferences, perceived benefits of zinc and reasons for discontinuing zinc treatment.z–tests to assess the statistical equivalence of adherence by age category and zinc product formulation .We conducted statistical data analyses using Stata 12.0 software . We summmodel 1); the log odds of receiving the age appropriate zinc dose onto an indicator of whether the provider gave such instructions (model 2); the log odds of receiving the age appropriate dose for 14 days onto an indicator of whether the provider advised the correct dose and duration of therapy. All models controlled for age category (7–59 months vs 2–6 months), duration of the diarrheal episode in number of days, caregiver education (at least 1 year of school vs no school), and poor socioeconomic status as indicated by the possession of a BPL card  of the 120 caregivers of children meeting the inclusion criteria  and specifically from a community–based provider cadre known as Accredited Social Health Activists (ASHAs)  received a zinc instructional pamphlet from the provider who advised treatment, but the majority reported receiving provider instructions on how to prepare and administer zinc (96.5%), on how long to continue the zinc treatment course (90.3%), and on the daily dose to administer (100%). On average, caregivers were advised to give zinc for 13.8 days (SD = 1.2 days); 89.4% were told to continue treatment for 10–14 days and 85.8% for exactly 14 days. Among children 2–6 months of age, appropriate dosage instructions  were received by 65% and 33% of those treated with tablets and syrups, respectively. In the older age group, appropriate dosage instructions  were received by 69% treated with tablets and 20% treated with syrups. In total, 55.8% (n = 63) of caregivers were advised according to the GoI/IAP guidelines on both dose and duration of zinc treatment ,18. In aOn average, children received zinc for 10.7 days . Zinc treatment was continued for 10–14 days and for the complete 14 days by 63.7% (n = 72) and 47.8% (n = 54) of caregivers, respectively. The age appropriate dose was administered to 30.8% of the 13 syrup–treated children and to 67.3% of the 101 tablet–treated children.P = 0.996). Adherence to the advised 14 days was higher among children treated with tablets (53.3%) compared to syrups (40.0%) but this difference was not statistically significant (P = 0.563).Of the 97 caregivers instructed by providers to continue zinc therapy for 14 days, 52.6% adhered. There was no statistically significant difference in adherence to the duration of treatment by the child’s age (P = 0.500). There was no statistically significant difference in adherence to age appropriate dosage instructions by product formulation of tablets (75.0%) compared to syrups . No child received more than one zinc dose per day but, but 2 (20.0%) syrup–treated and 4 (66.7%) tablet–treated children aged 2–6 months received the daily dose intended for children in the older age category.Adherence to dosage instructions was 87.5% among the 72 caregivers who received age appropriate advice; when stratified by age, 92.9% of caregivers of children ≤6months were dose–adherent compared to 86.2% in the older age group  complied with both sets of instructions. All 86 caregivers told to administer ORS did so at least once during the episode.Models 1 and 2), but adherence to both dose and duration was lower among caregivers of children aged 7–59 months  and those from households below the poverty line  (Model 3).Continuation of zinc treatment for 14 days and adherence to age appropriate dose were highly associated with appropriate provider instructions  compared to ORS (58.4%), syrups (81.4%) and tablets (92%). The perceived benefits of zinc among caregivers included reduced stool frequency (56.6%) and volume (5.3%), as well as decreased duration (18.6%) and severity (5.3%)  was higher than that advising age appropriate dose (63.7%). In addition, a higher proportion of providers offered correct dosage instructions on tablets than syrups. We observed the opposite trend among caregivers for whom adherence to provider instructions on the 14–day duration of zinc treatment (52.6%) was lower than those on age appropriate dose (87.5%). This finding suggests that the zinc adherence challenges are different for providers and caregivers and thus critical to future program planning. Providers may experience difficulty in recalling and/or communicating zinc dose instructions, which are complicated by age cut–offs and differences by product formulation . On the other hand, caregivers are required to remember only one set of dosage instructions tailored to their child’s specific age and product formulation and are perhaps less likely to encounter recall issues.Our data indicate that for caregivers, compliance to dose is less challenging than continuation of zinc for the advised number of days, which is made difficult by the tendency to terminate treatment once a child appears to have recovered from diarrhea. Since the majority of diarrheal episodes among children under–five are acute , there is considerable discordance between the duration of illness and the advised therapeutic course. In a recently published RCT, the majority of participants (73.7%) could not be included in per–protocol analyses because treatment of both placebo– and zinc–randomized children was discontinued when diarrhea halted . In ordeWe observed a strong correlation between receipt of proper zinc treatment instructions and the odds a child received the age appropriate dose for 14 days. This finding is critical as it underscores the willingness of caregivers to heed the diarrhea treatment advice of providers and thus the importance of ensuring providers are well–trained. We did not find any evidence of children receiving more than one zinc dose per day, but six infants 2–6 months of age received the dose intended for older children. Future diarrhea treatment programs should ensure adequate training of providers in the complex zinc dosage guidelines, especially for young infants. Providers might benefit from visual demonstrations and hands–on practice in the preparation of each of the four zinc syrup/tablet doses. This approach could potentially maximize providers’ retention of age cut–offs and ability to communicate such information to caregivers.Our findings confirm reports that zinc treatment does not interfere with adherence to ORS ,8, as alThis study is limited by the reliance on caregiver report to gauge provider instructions on zinc treatment dose and duration. We reduced the threat of recall bias among caregivers by restricting inclusion to children with diarrhea occurring in the last 7 days who were treated with zinc in the 3 days preceding the initial household visit. Possession of zinc products and packaging among all enrolled caregivers at the first household visit suggests that zinc procurement and thus receipt of zinc instructions occurred recently relative to the timing of the visit, thereby lessening the likelihood of misreporting. To prevent recall issues at follow–up, we employed tracking forms to assist caregivers in monitoring treatment of the episode.This study is also limited by an inability to stratify estimates of adherence by the sector or specific provider cadre from which zinc was procured, since the overwhelming majority of zinc was advised by ASHAs (85.8%). This limitation highlights larger programmatic questions concerning the limited availability of zinc stocks and the low propensity to advise zinc treatment in the private–sector and through certain public–sector outlets . Nonethe


To evaluate evidence of the capacity for causal inference in studies of associations between parental and offspring alcohol consumption in the general population.A systematic search for, and narrative analysis of, prospective cohort studies of the consequences of drinking, except where assessed prenatally only, or with clinically derived instruments. Primary outcome measures were alcohol use or related problems in offspring, which were collected at least 3 years after exposure measures of parental drinking. The systematic review included 21 studies comprising 26 354 families or parent–child dyads with quantitative effect measures available for each study. Criteria for capacity of causal inference included (1) theory‐driven approach and analysis; (2) analytical rigour; and (3) minimization of sources of bias.Four of the 21 included studies filled several, but not all, criteria and were assessed to have some capacity for causal inference. These four studies found some evidence that parental drinking predicted drinking behaviour in adolescent offspring. The remaining 17 studies had little or no such capacity.There is a fairly large and consistent literature demonstrating that more parental drinking is associated with more drinking in offspring. Despite this, existing evidence is insufficient to warrant causal inferences at this stage. Alcohol consumption is one of the major risk factors for loss of healthy years of life globally Systematic reviews of prospective cohort studies offer the highest quality observational evidence available for assessment of the true consequences of parental drinking for the onset and development of alcohol use and related problems in young people. Cohort studies have the capacity to ascertain the time order of exposure and outcome and thus to rule out reverse causality. However, drawing causal inferences from observational epidemiological studies should also be based on testing theory‐driven causal hypotheses, applying sufficient analytical rigour and identification and control of sources of bias The importance of assessing possible causal effects of parental drinking pertains not only to a better understanding of complex mechanisms underlying young people's drinking behaviour, but it has also policy implications. Within a ‘harms to others’ framework, we are interested in the consequences of parental drinking that can be prevented by interventions which reduce parental drinking. In this perspective, both environmental influence and genetic disposition and their interaction are of interest. The literature on familial transmission of alcohol use and of alcohol use disorders (AUD) suggests several mechanisms that may explain observed associations between parental and offspring alcohol use or AUD A recent scoping review of cohort studies of parental drinking and adverse outcomes in children We sought studies that followed prospectively families or individuals of interest over a period of time, having at least two data collection points. Exposure data collection was required to precede outcome data collection in time. We included studies published in English language peer‐reviewed journals from 1980 onwards. Participants included both parents and children from general population samples; those from ‘special populations’ who may have distinct exposure–outcome relationships, e.g. mental health patients, were excluded. We excluded studies where parental drinking was measured with clinical instruments (ICD/DSM) or by brief screening tools derived from diagnostic instruments designed to identify alcohol dependence or ‘alcoholics’ [e.g. ‘The Michigan Alcoholism Screening Test (MAST)]. Clinical measures were permitted as outcomes. Studies which assessed only alcohol consumption in parents, or consumption plus problems, were included without any lower consumption limits, as were problem measures not derived from ICD/DSM criteria as they were judged probably a priori to assess less severe forms of problems. Studies in which the only parental alcohol data were maternal alcohol use measured during pregnancy were excluded.A summary of the data collection process is illustrated in the PRISMA  flow‐chart Fig. . We follIn the assessment of these 21 studies, we built on contemporary thinking about causal inference in observational studies n = 11) [n = 3) [n = 3) n = 2) n = 1) [n = 1)The studies were conducted in six different countries: the United States n = 1 [n = 3)The exposure measure varied substantially between the studies with regard to type of drinking behaviour , age of exposure and putative relationship to outcomes (from before pregnancy to young adulthood), and whose drinking behaviour was measured  in 16 of the studies. In five studies the outcome was some kind of alcohol‐related problem , either as a single outcome (three studies) The vast majority (19 of 21 studies) reported at least one positive association between parental drinking and offspring's alcohol‐related outcome, while only two studies Next, we assessed the studies' capacity for causal inference according to the aims of this study and the evaluation framework described previously in relation to parental drinking and alcohol‐related outcomes in offspring. All studies had some favourable characteristics in this respect; for instance, graded exposure measures or large sample sizes Table . HoweverAmong the four studies The study by Mares and co‐workers The study by Latendresse and co‐workers 2 = 3.51, P = 0.06).Finally, we assessed whether our inclusion criteria for this analytical review had impacted upon our findings. The 21 studies included in our review differed very little from the findings of 28 excluded studies with either child report of exposure, or a gap of less than 3 years between exposure and outcome measurement. A combined measure for both parents tended to be used when parental drinking was reported by offspring, and only 55% of these studies found an association between parental and offspring drinking, compared to 78% of studies using parental report  common local environment  influences on both parental and offspring drinking, such as physical access to alcohol and price; (b) common cultural or religious factors including both those that enhance and limit or proscribe drinking that affect both parental and offspring drinking; and (c) parental comorbidity/temperament and other psychobiological factors affected by genetic transmission. These factors may either moderate or mediate mechanisms, or both, and are seldom addressed in the studies included in this review. Failure to demonstrate mediation effects as they were hypothesized in two As well as evaluation of the included studies, consideration of the strengths and limitations of this study is appropriate. A fairly large literature on cohort studies of parental and offspring drinking was identified through extensive and systematic literature searches. Applying a set of criteria for drawing causal inferences, including theoretical underpinning and analytical rigour, enhanced the systematic evaluation of the studies' contributions in this respect. This process has also been made as transparently as possible, permitting readers to assess its rigour and its limitations. Studies from different national and cultural contexts were identified, although these were restricted entirely to Anglophone and northern European countries. The selection of studies was restricted to those published in the English language, implying that relevant studies in other languages may exist, but have not been identified in this review. Diverse measures of exposures and outcomes entailed difficulties in conducting quantitative syntheses and it may have been possible to pursue quantitative investigations, notwithstanding the heterogeneity we encountered.The lack of standardization in measurement may also be regarded as a limitation of the literature as a whole, hampering comparability across studies. For instance, with respect to adolescents' drinking behaviour, there is a distinction between sipping and consumption of full beverages The determination of study quality did not consider self‐report bias in both exposure and outcome measures, and is otherwise absent from this study design except in separating the two reports in time. Self‐reported drinking behaviour is often under‐reported, and this leads to a biased estimate of the associations with consequences Strategies to prevent harmful drinking in young people and its acute and long‐term health and social consequences may target parents and parental drinking and include general population strategies None.Supporting info itemClick here for additional data file.


MD_evReader) developed as a reading aid for individuals with a central field loss resulting from macular degeneration. The MD_evReader app scrolls text as single lines (similar to a news ticker) and is intended to enhance reading performance using the eccentric viewing technique by both reducing the demands on the eye movement system and minimising the deleterious effects of perceptual crowding. Reading performance with scrolling text was compared with reading static sentences, also presented on a tablet computer.Technological devices such as smartphones and tablets are widely available and increasingly used as visual aids. This study evaluated the use of a novel app for tablets (Twenty‐six people with low vision (diagnosis of macular degeneration) read static or dynamic text (scrolled from right to left), presented as a single line at high contrast on a tablet device. Reading error rates and comprehension were recorded for both text formats, and the participant's subjective experience of reading with the app was assessed using a simple questionnaire.p = 0.02) less for dynamic text than for static text. The participants’ questionnaire ratings of their reading experience with the MD_evReader were highly positive and indicated a preference for reading with this app compared with their usual method.The average reading speed for static and dynamic text was not significantly different and equal to or greater than 85 words per minute. The comprehension scores for both text formats were also similar, equal to approximately 95% correct. However, reading error rates were significantly  is better than static text. Bespoke apps informed by an understanding of the underlying sensorimotor processes involved in a cognitive task such as reading have excellent potential as aids for people with visual impairments. RSVP). The use of dynamic text presentation methods could aid reading in individuals with a central field loss (CFL)Smartphones, tablets and electronic readers often incorporate basic features such as image enlargement and high‐contrast screens that can be used as effective low vision aids.Individuals with macular degeneration often make use of their relatively preserved peripheral vision and self‐select a preferred area of their eccentric retina .The effective use of eccentric viewing for reading requires the reader to be able to hold an eccentric gaze position (at their PRL) and this ability can be compromised in people with MD,An advantage of electronic devices is that they can enable text to be presented with dynamic formats and this may have wide‐ranging benefits for people with low vision. Furthermore, other potential textual characteristics  can also be manipulated. The present study examined reading performance and subjective reading experience with static and scrolling text in individuals with macular disease. Participants read single sentences of either static or scrolling text presented on a tablet (iPad2) and were instructed to adopt an eccentric viewing strategy.The participants were all recruited from the membership of the Macular Society (UK), which actively promotes the eccentric viewing technique. As such it was expected that participants would, in general, be aware of this technique. As they were not recruited from a clinical setting they were not ‘patients’ as such and we did not have access to their clinical details (e.g. whether they were receiving treatment or not). The inclusion criteria were: a diagnosis of binocular macular degeneration (wet or dry); over 18 years of age, binocular distance acuity between 0.30 and 0.80  logMAR  and English as primary language. The exclusion criteria were: inability to read 24‐point font; ocular co‐morbidity; dyslexia and any cognitive impairment. Informed consent was collected from all participants prior to the study, as approved by Royal Holloway Psychology departmental and NHS ethical review .). A double space was included between each word to reduce visual crowding.R  presentation app that allows text to be manipulated and presented on an iPad . At the end of each sentence the participant was asked a simple comprehension question (e.g. ‘Was it a rock band that took requests?’). A digital mp3 recorder recorded the participants reading aloud for later off‐line scoring. Binocular reading acuity was measured using the MNRead Acuity Chart.The sentences used in the assessment of reading performance consisted of 40 sentences from the MNRead compilation,Following the assessment of reading performance, participants completed a short user evaluation questionnaire Appendix . Items pFigureBinocular visual acuity was assessed using the MNRead Acuity chart at a distance of 40 cm (or 30 cm if required). The eccentric viewing and steady‐eye strategies were explained to participants and they were asked to adhere to these strategies as much as possible when reading. The preferred retinal locus for each participant was assessed using an Amsler chart: ten participants had received training in eccentric viewing (provided by the Macular Society) and were aware of their ideal PRL. For scrolling text a movable fixation marker . Reading performance measures for scrolling and static text formats were examined using non‐parametric statistics (Wilcoxon signed‐ranks test), and the median was used to describe the Likert‐scale questionnaire scores.The audio recording enabled reading speed and errors to be quantified after the session. A sentence was deemed to contain errors if the participant omitted words, added additional words, or read a word incorrectly (even if they subsequently corrected the error). After each sentence, participants were asked a comprehension question and were required to respond with either “Yes” or “No”. An incorrect answer was scored as zero, while a correct answer was scored as one. Reading speed was recorded for each sentence with a stopwatch. It should be noted that for scrolling text participants typically waited for some seconds for words to appear on the screen before they started to read aloud.Twenty‐six  adults aged from 42 to 93 years (mean age = 75.8 years) volunteered to take part in the study. Of these, 14 had attended a higher education institute, including 11 at University/Polytechnic level. All reported a prior diagnosis of macular disease as follows: left eye diagnoses included: 14 wet AMD, 10 dry AMD and two Stargardt disease; right eye diagnoses included: 10 wet AMD 14 dry AMD and two juvenile forms (Stargardt's disease). Average length of diagnosis was 110 months (range 8–516 months). Ten participants (38.5%) had prior knowledge of the eccentric viewing technique and stated that they used the strategy for tasks, including reading (average time using EV was 35.5 months).TableFollowing the initial assessment of the PRL, twenty‐two participants positioned the fixation stimulus (a cross) above the line of text, while four positioned the stimulus below the sentence. The first trial of static and scrolling text were excluded, with each participant's reading assessed on the remaining 19 sentences for each condition . The overall number of reading errors was low  and the difference between the two conditions was not significant . The proportion of sentences read without errors was, however, significantly greater for scrolling text (77.9%) than static text (72.7%), Wilcoxon‐signed‐ranks test Z=−2.26, p = 0.02, r = 0.82).Comprehension performance was high for both the scrolling and static text formats (94.3% and 94.9% respectively), and a comparison between conditions was not significant (Wilcoxon‐signed‐ranks test t(25) = 1.94, p = 0.064].The average time taken to read was 7.2 s for static sentences  and 7.8 s for scrolling sentences , which equates to reading speeds of approximately 91.6 and 84.6 words per minute respectively. A t‐test confirmed that reading speed was comparable in the two text formats [AppendixFollowing the reading assessment participants completed a short questionnaire designed to probe their prior knowledge and stated use of the eccentric viewing technique and also their subjective experience of reading scrolling text presented using the MD_evReader app. The questionnaire items and the median responses on a five‐point Likert scale are reported in Reading performance in 26 adults with binocular macular degeneration and a central field defect was assessed using a tablet with an app developed to enhance eccentric reading.AppendixThe questionnaire ratings of user experience of reading scrolling text with the MD_evReader app were positive Appendix. The maj23 combining eccentric viewing with static and a wider range of dynamic formats (scrolling and RSVP) over a longer period of time, with added performance measures . User feedback could be collected using features incorporated into the app rather than relying on a separate questionnaire.The limitations of the present study include the lack of prior experience of eccentric viewing for some participants and the potential unreliability in the assessment of the participants’ PRL with an Amsler grid. Future studies could investigate the effects of perceptual learning,The authors report no conflicts of interest.


Retrospective measures of alcohol intake are becoming increasingly popular; however, the reliability of such measures remains uncertain. This study assessed the reliability of a retrospective decade‐based life‐course alcohol consumption questionnaire, based on the standardized Alcohol Use Disorder Identification Test–Consumption (AUDIT‐C) administered in older age in a well‐characterized cohort study.A retrospective alcohol life‐grid was administered to 5980 participants  in the Whitehall II study covering frequency of drinking, number of drinks in a typical drinking day and frequency of consuming six or more drinks in a single drinking occasion in the teens (16–19 years) through to the 80s. A subsample of 385 individuals completed a repeat survey to determine test–retest reliability. Retrospective measures were also compared with prospectively ascertained information and used to predict objectively measured systolic blood pressure to test their predictive validity.Across all decades of life, test–retest reliability was generally good . The concordance between prospective and retrospective measures was consistently moderate to high. The life‐grid method performed better than a single question in identifying life‐time abstainers. Retrospective measures were also related to systolic blood pressure in the manner anticipated.A retrospective decade‐based AUDIT‐C grid administered in older age provides a relatively reliable measure of alcohol consumption across the life‐course. The effect of variation in alcohol consumption across the life‐course is an important yet neglected topic One approach is to construct retrospective accounts of an individual's life‐time drinking history. Previous work on retrospective measures of alcohol consumption has shown that they are relatively reliable in capturing life‐course patterns of consumption Decade‐based retrospective measures of consumption have been advocated as a feasible alternative to in‐depth retrospective measures Previous discussion on the topic of assessing alcohol consumption across the life‐course with retrospective measures has highlighted the issue that often asking participants to recall exact amounts is typically associated with poorer recall, while asking them to provide relative rankings seems to produce stable responses However, while the focus thus far has been on the positives of retrospective measures, it is important to note that they are inherently limited The purpose of this paper is therefore to assess the reliability of a retrospective decade‐based life‐course alcohol consumption questionnaire, based on the AUDIT‐C, administered in older age.n = 5980, 58% of the original sample and 95% of those participating in the most recent phase). A subsample of participants completed a repeat alcohol life‐course survey (n = 385). The subsample consisted of a random‐stratified sample (weighted by age group and gender proportions) of the initial 3000 responders at phase 11. In total, 500 repeat questionnaires were posted to participants , with a final response rate of 77%. The Whitehall II study is approved by the Joint University College London/University College London Hospital Committees on the Ethics of Human Research (Committee Alpha). All participants provided written informed consent.The Whitehall II prospective cohort study started as a sample of 10 308 British civil servants (6895 men and 3413 women) based in London offices who were aged 35–56 years at entry into the study in 1985–88 http://www.ucl.ac.uk/whitehallII/data‐sharing.Whitehall II data, protocols and other metadata are available to bona fide researchers for research purposes. Please refer to the Whitehall II data‐sharing policy at Participants were asked to report the frequency that they consumed alcohol in the past 12 months seven times during follow‐up . Response options were: never, special occasions, monthly, weekly, daily or more than once daily.As participants could report information concerning their frequency of consumption at multiple times during the course of a specific decade of their life, the modal frequency response reported by participants while they belonged to specific decade‐based age‐groups  during follow‐up was taken as an indicator of how often they consumed alcohol while that age.The first two study phases contained questions on the usual number of drinks  a participant consumed in a single drinking session separately for beer and for wine and spirits combined. As these questions did not allow for participants to report drinking sessions whereby they mixed beer with wine/spirits, the highest frequency response to either item was taken as a participant's usual amount (e.g. someone reporting consuming 1–2 pints of beer but five or more glasses of wine/spirits would be assigned to the five or more drinks category). Again, the modal response to this question while participants belonged to specific decades was taken as their usual amount at that age.Unfortunately, no prospective information regarding frequency of consuming six or more drinks in a single occasion was available throughout Whitehall II follow‐up.We used prospectively collected information relating to both frequency of alcohol consumption in the past 12 months collected at each study phase, as well as responses to a question asking those who reported no consumption in the past year as to whether they were always a non‐drinker, which was introduced at phase 3. We used a strict definition of life‐time abstention, insisting that participants consistently reported no alcohol consumption Life‐course alcohol consumption was defined using decade‐based grids starting with information in the teens (16–19 years) and spanning to the 80s (and older) on the three components of the AUDIT‐C questionnaire: frequency of consumption, number of drinks on a typical drinking day and frequency of consuming six or more drinks at a single occasion The age of participants at each phase was calculated and used to define the decade of life to which they belonged. Gender was recorded at baseline. Socio‐economic position was defined, using either current or last recorded civil service employment grade. Civil service grades are hierarchical and are based on salary and work role; we defined socio‐economic position in three levels as high (unified grades 1–7), intermediate (executive officers) or low , as described previously Information regarding current drinking habits was obtained via the standard AUDIT‐C questionnaire, covering drinking frequency in the past 12 months as well as usual amount consumed in a drinking session and frequency of consuming six or more drinks in the same period. Participants were defined as current hazardous drinkers using their AUDIT‐C scores at a threshold of scores of four for men and three for women Participants completed the 30‐item Mini Mental State Examination (MMSE). A threshold of scores of less than 27 was used to identify individuals with current mild cognitive impairment Systolic blood pressure (SBP) was measured with participants in the sitting position. SBP was determined twice, with 5 minutes rest between measurements—the average of these two readings was used as the final measure.Weighted kappa coefficients (κ) were used to assess the test–retest reliability of individual life‐course AUDIT‐C items. Weighted kappas were chosen as they are preferable when assessing the agreement between ordinal scales Polychoric correlations  Linear regression was used to estimate differences in SBP on the basis of current reports of consuming six or more drinks in a single drinking occasion at least monthly as well as retrospectively assessed consumption with adjustment for current age, gender, socio‐economic position and smoking status. SBP was chosen as an outcome based on its causal association with alcohol consumption All analyses were conducted using Stata version 13  Presented in Table Kappa coefficients relating to frequency of alcohol consumption are presented in Table Men had consistently lower reliability for early life measures (ages 16–29) than women, but from midlife onwards gender coefficients were relatively equal. Binary categorization of age into 50–69 and 70+ years revealed that reliability was typically poorer in older participants. Recall was also generally poorer in participants who belonged to the highest socio‐economic group. Present hazardous drinkers had lower reliability in their recall, while no consistent difference in reliability was observed for those with mild cognitive impairment.Test–retest reliability for the usual number of drinks on a typical drinking day Table  was geneNo consistent gender bias was observed for the reliability of usual number of drinks recalled across the life‐course . Throughout recall of early life alcohol consumption no stable age‐related bias was observed; however, from mid‐life (40+ years) onwards those in the older age group consistently had lower κ values than younger cohort members. Those from the highest socio‐economic group tended to recall more clearly the number of drinks they reported consuming in a typical drinking day than those from lower socio‐economic groups, as did current non‐hazardous drinkers. Again, no notable pattern was observed between those with mild cognitive impairment and those without.Reliability estimates for frequency of consuming six or more drinks in a single occasion Table  generallWomen had higher reliability in their recall from age 16–29, but from age 40 onwards men were more consistent in their recall. Younger participants were also more consistent with their recall of frequency of consuming six or more drinks in a single occasion up until the age of 50, at which point reliability estimates were similar to older participants. Those from the lowest socio‐economic group were less consistent with their recall, as were those whose drinking pattern was considered non‐hazardous based on their AUDIT‐C score. In this instance, those with mild cognitive impairment had lower κ values than those without.Correlations between prospectively collected data on frequency of consumption with retrospectively collected information are presented in Table No significant age, gender, socio‐economic position or memory related biases were observed. Those whose current drinking was defined as hazardous tended to have poorer agreement between prospective and retrospectively recalled information.As in the test–retest analyses, generally the correlations between retrospective measures of number of drinks consumed on a typical drinking day and prospective measures relating to the same item were lower than those found for measures relating to frequency Table .In the whole sample, correlations tended to remain stable over age (from 35 years onwards). The correlation between retrospective and prospective measures was greater in men at age 50–59 years than in women. No consistent difference between socio‐economic groups was observed, nor by current drinking status or presence of mild cognitive impairment.There were inconsistent reports of life‐time abstention by participants in the same questionnaire Tables  and 5. FTable We found that a retrospective decade based AUDIT‐C grid appears to provide a reliable measure of consumption across the life‐course in older adults. Reliability tended to be greatest for measures relating to frequency of consumption in general as well as frequency of drinking six or more drinks in a single occasion compared to the item relating to number of drinks consumed on a typical drinking day. Current alcohol consumption seemed to influence the accuracy of recall; however, even within strata with hazardous consumption test–retest reliability and correlations between retrospective and prospective measures tended to fall within acceptable ranges. Our findings have implications for both studies that are already in existence  as well as studies in the planning stage, allowing them to adopt the cross‐sectional cohort Similar to studies examining the test–retest reliability of the LDH questionnaire Like other studies on the stability of self‐reported life‐time abstaining, we found that there were generally large inconsistencies in reporting We found that simplified trajectories based on responses to frequency of drinking six or more drinks in a single occasion were related to systolic blood pressure, as in previous studies The strengths of our study are the large sample size used for comparing retrospective and prospective measures , we would argue that this item would probably be as robust—although we welcome future research to confirm or refute this extrapolation.Another potential source of bias is the age of participants in our study . One could argue that it is unrealistic to expect those in later life to recollect information on alcohol consumption from up to 60 years earlier. Previous discussions We used data from the Whitehall II cohort of British civil servants, which is not a representative sample of the general population. It is also worth noting that our sample is made up of individuals who have remained in an epidemiological study for ~28 years. This is a form of selection bias In addition to the avenues for future work outlined above, it is important to determine the extent to which decade‐based measures of consumption fail to capture important changes (e.g. moving from high to low or no consumption) across the same 10‐year period and how this shortcoming in the method may influence exposure–outcome associations. While adding this additional level of detail to our life‐course alcohol grid is possibly unnecessary (continuing the philosophy of less is more when it comes to addressing life‐course consumption with retrospective measures), it is worth trying to quantify this bias so that appropriate correction factors may be derived.Furthermore, it is crucial that the reliability of our adapted life‐course AUDIT‐C is examined in other cultures (and indeed replicated using other UK data sources), as previous studies have shown that there are cultural differences in the retrieval strategies used by individuals across Europe to answer standard questions relating to alcohol consumption While prospectively collected data should be preferred, it appears that a decade‐based AUDIT‐C grid seems to provide a reliable measure of consumption across the life‐course in older adults. This method could be used in existing longitudinal studies where alcohol intake earlier in the life‐course is not already measured, included at the baseline of studies in planning to gauge alcohol intake prior to enrolment, or used in cross‐sectional studies.None.


RD can also present in the skeletal muscle, mimicking several other diseases. It is unusual for this relatively new classification of diseases to present in the muscles and can be mistakenly diagnosed as other autoimmune diseases rendering a delay in the appropriate management and progression of the disease.IgG4‐ A 68‐year‐old lady of an African American descent presented to the office with complains of unintentional weight loss of thirty pounds over the last year. She had a history of follicular lymphoma that had transformed to a diffuse large B‐cell lymphoma (DLBCL) diagnosed more than 20 years ago. It was treated with eight cycles of chemotherapy  followed by radiotherapy. She underwent complete remission with no evidence of recurrence until now.She was noted to have pancytopenia in September 2014. Owing to a concern for the recurrence of lymphoma, a positron emission computerized tomography (PET–CT) was obtained which revealed a mass in her psoas muscle. Biopsy of the mass showed the presence of a few macrophages and failed to reveal any evidence of malignancies or reoccurrence of lymphoma.The patient then started noticing further weight loss and decrease in her appetite since, and presented to the office again after a year. A repeat PET–CT was performed which demonstrated an overall enlargement of the left iliac and psoas muscles Fig. . The FDGCore biopsy of the masses performed thereafter revealed fibrosis with sparse lymphocytic infiltrate and hemosiderin deposition, unremarkable plasma cells, without evidence of a lymphoma (histopathology slides 1–3). A quantitative IgG was performed that showed a value of 2030 mg/dL (reference range: >19 years of age 700–1600 mg/dL). IgG4 subclass was also significantly elevated at 1022 (reference range 7–89). Workup for multiple myeloma was negative with serum protein electrophoresis showing a chronic inflammatory pattern and did not identify a monoclonal protein, but rather a polyclonal increased in IgG. Other laboratory investigations were as follows: Creatinine 0.75 mg/dL, LDH 135 U/L, BUN 18 mg/dL; .The patient was seen in consultation, and a recommendation was made to treat her with steroids after discussing her case with the pathologist.Formerly known as IgG4‐related systemic disease, IgG4‐related disease (IgG4‐RD) is a relatively newly discovered fibro‐inflammatory condition and is named so due to the presence of antibody subtype IgG4‐producing plasma cells, that are present in large amounts on tissue samples from involved organs. It has a characteristic histologic appearance and elevated IgG4 concentrations in the acute phase of approximately 60–70% of its patients IgG4‐RD can virtually occur in any organ of the body with the most common sites as the salivary glands, periorbital tissues, pancreas, biliary tree, kidneys, lungs, lymph nodes, breast, aorta, thyroid, prostate, and skin IgG4‐RD has been labeled as a slow condition as usually symptoms tend to be mild in spite of considerable organ destruction, if any. People are often described feeling relatively well at the time of diagnosis, although some may give a history of weight loss. Pain is usually not a feature of the inflammation but may occur as a secondary effect due to some form of obstruction or compression. A diagnosis is often formulated due to the presence of painless swellings or mass lesions that may lead to complications. Incidental lesions may also be detected on radiological studies and can be easily misdiagnosed as a malignancy.Helicobacter pylori and constituents of pancreatic epithelial cells suggesting gastric H. pylori infection may set off autoimmune pancreatitis in genetically predisposed individuals via cross‐reactivity of the antibodies, yet autoimmunity has not been completely proved. Antibodies directed against potential auto‐antigens to some degree, may be associated with systemic manifestations of IgG4‐RD Several genetic studies suggest the involvement of several human leukocyte antigen (HLA) and non‐HLA haplotypes/genotypes that may be associated with susceptibility to IgG4‐RD or to disease relapse post therapy Radiographic features are generally nonspecific and may not provide a reliable distinction between IgG4‐RD and malignancy. A majority of patients with IgG4‐RD have elevated serum IgG4 levels of varying ranges with approximately 30% of patients having normal serum IgG4 despite classic histopathological and immunohistochemical features Induction and maintenance of remission are the main treatment goals to prevent progression of fibrosis and organ damage. All cases of symptomatic IgG4‐RD warrant treatment though some cases of asymptomatic IgG4‐RD may require early management to prevent severe complications like aoritis, pericarditis, and pachymeningitis Glucocorticoids are the recommended first‐line agents for induction unless contraindications exist resulting in rapid improvements of symptoms and a resolution of radiographic findings. Steroid‐induced flares are not uncommon. Although their efficacy has never been tested in clinical trials, rituximab, mycophenolate mofetil, methotrexate, and azathioprine are used frequently as glucocorticoid‐sparing agents or remission‐maintenance drugs after glucocorticoid‐induced remissions κB) Bortezomib, an excellent proteasome inhibitor has been a novel drug which is currently approved for and used in the management of relapsed leukemias and multiple myelomas in the posttransplant setting. Several preclinical trials showed antimyeloma effects of bortezomib including the disruption of the cell cycle and apoptosis induction, alteration of the bone marrow microenvironment, and inhibition of nuclear factor kappa B (NFIgG4‐RD encompasses a large number of medical disorders previously referred to as confined to a single organ. As a recently recognized condition, links among the increased quantities of IgG4 plasma cells, varying quantities of serum IgG4, and its histological features needs to be determined. Despite being a rare case in itself, to the knowledge of the authors, this is the second known case of IgG4‐RD to occur in the skeletal muscles.None declared.


WB) magnetic resonance imaging (MRI) into the management pathway for patients with multiple myeloma. The speed, coverage and high sensitivity of WB diffusion weighted (DW)‐MRI and the unique capability to quantify both burden of disease and response to treatment has led to increasing implementation at leading centres worldwide for imaging malignant marrow disease, both primary and metastatic. WB DW‐MRI is likely to have a significant impact on management decisions and pathways for patients with multiple myeloma. This review will introduce the basic principles of DW‐MRI, present current evidence for patients with myeloma and will discuss practicalities and exciting future applications.The recent consensus statement from the International Myeloma Working Group has introduced the role of whole body ( Low b values interrogate large diffusion distances and are therefore sensitive to flow in blood vessels. Large b values detect small diffusion distances that are postulated to be related to extracellular space distances and, therefore, thought to be directly related to cell packing/cellularity. Theoretically, with very large b values (>4000 s/mm2), it is possible to interrogate the movement of intracellular water protons, but at a practical level this is extremely challenging.Diffusion weighted‐MRI produces images where the contrast between tissues is based on differences in the motion of water at a cellular level. Water motion in tissues occurs within different compartments – intracellular, transmembrane, extracellular and intravascular. Choice of diffusion weighting  for each pixel in the image and a quantitative map can be produced. Tumours that consist of tightly packed cells therefore appear as areas of highly restricted diffusion‐high signal on source diffusion images and low on ADC . A 3·3% increase in ADC helped identify response with 90% sensitivity and 100% specificity. Visual assessment was also able to identify response to treatment with high sensitivity  with good agreement in the post‐treatment change between 2 observers. There was a significant negative correlation between change in ADC and change in laboratory markers of response. Conversely, Hillengass et al  and T2W sagittal of the whole spine. This allows assessment of vertebral fractures and threat to the spinal cord or nerve roots. However, a total imaging time of 45 min necessitates appropriate patient selection. For example if a patient presents with symptoms suspicious for spinal cord compression this scanning time may not be tolerable and imaging should be confined to assessment of disease in the spinal column. Referring haematologists and specialist myeloma nurses at our institution have become well acquainted with imaging times and refer patients appropriately and therefore WB protocols are extremely well tolerated at our institution.Developing a WB DW‐MRI protocol necessitates balancing robust data acquisition that fulfills clinical need and a time frame that is tolerable for the patient Fig . Currentet al, et al, et al, et al, versus malignant fracture. Greater understanding of appropriate diffusion protocols and combination with morphological imaging is likely to move this forward as a useful tool.The combination of morphological and functional data also allows for detection and characterization of vertebral fractures. Although morphological features of diffuse T1 low signal, convex vertebral contour, involvement of pedicles and a lumbar level are more frequently observed in malignant fractures . Granulocyte colony‐stimulating factor (GCSF), given either as part of preparation for ASCT or for supportive measures, leads to hypercellular marrow, which can mimic diffuse infiltration (Fig Red marrow has an altered diffusion signal compared to yellow marrow and therefore detection of marrow disease in younger patients can be challenging. However this is rarely problematic for myeloma as the incidence is strongly related to age with an average of 43% cases diagnosed in people aged 75 years and over (tion Fig . This isThe advent of WB DW‐MRI has been one of the most significant advances for imaging in oncology patients over the last decade. The high sensitivity, speed and quantitative capabilities have addressed an unmet need in imaging primary and secondary marrow malignancies. We have been providing a WB DW‐MRI service for patients with myeloma since 2011 and the number of UK and International centres delivering this service is growing.Combined with anatomical imaging, WB DW‐MRI now forms an imaging tool that has been tailored to detect both focal and diffuse disease, to quantify burden and response whilst also assessing mechanical complications. This blend of anatomical and functional imaging is well suited to serve the imaging needs of patients with myeloma. The necessity for WB imaging of patients with SMM and solitary plasmacytoma is now recognized. However future studies will need to direct positioning of WB DW‐MRI alongside emerging molecular and genetic signals as predictive and prognostic biomarkers. If future studies corroborate the usefulness of whole marrow segmentation techniques, academic and industrial collaborations will be essential to translate this from research to clinical settings. It is also likely that WB DW‐MRI will have an increasing role in stratifying risk and, as the number of treatment options continues to grow, it is likely to find its place in guiding therapeutic strategies.Both authors have contributed to the concept, literature review and writing of this review article.


TopFluor‐Cholesterol, TF‐Chol) is a widely used cholesterol analogue due to its excellent fluorescence properties and considerable similarity with natural cholesterol in terms of membrane partitioning. However, the suitability of TF‐Chol for detecting lysosomal cholesterol deposition has recently been questioned. Here, we highlight the fact that the method of lipid delivery and the analysis of time‐point both affect the membrane distribution and labeling pattern of TF‐Chol, similarly as with radiolabeled cholesterol. Lysosomal sterol accumulation characteristic to a lysosomal storage disease is most readily detected when the probe is introduced via the physiological route, i.e. as a sterol fatty acid ester in low‐density lipoprotein particles. When administered to cells from solvent, lysosomal sterol sequestration becomes evident after an overnight equilibration between membranes.Dipyrromethene difluoride‐cholesterol ( Recent advances in fluorescence microscopic techniques have sparked interest toward fluorescent lipid analogues that enable visualization of lipid distribution and trafficking in intact cells. These approaches are challenged by the fact that conjugation of fluorescent moieties tends to perturb lipid properties. This feature is highlighted in cholesterol, a small, hydrophobic and planar molecule. Cholesterol participates in the lateral ordering of the membrane, and even minor changes in its structure have been shown to alter this propensity One such probe now widely used is a dipyrromethene difluoride (BODIPY)‐labeled sterol analogue , originally designed by the group of Robert Bittman 3H]‐cholesterol between the plasma membrane and lysosomal pools has an apparent half‐time of 35 h A traditional test case for the cellular partitioning of cholesterol analogues has been Niemann–Pick type C (NPC), a lysosomal storage disorder that results in the accumulation of cholesterol in late endosomal compartments 3H]‐cholesterol Major differences in the behavior of TF‐Chol and radiolabeled cholesterol in cells are increased efflux and decreased esterification of TF‐Chol compared to [TF‐Chol can also be delivered to cells from artificial or natural hydrophilic carriers. The probe can be readily complexed with beta‐cyclodextrin to perform short (e.g. 2 min) pulse labeling of the plasma membrane In summary, both the method of lipid delivery and the analysis of time‐point affect lipid partitioning in cellular membranes. In the case of TF‐Chol, lysosomal accumulation characteristic to NPC disease is most readily detected when the probe is introduced via the physiological route, i.e. as a sterol fatty acid ester in LDL particles. When administered to cells from solvent, lysosomal deposition becomes evident after an overnight equilibration between membranes.Editorial ProcessClick here for additional data file.


ATP. However, in conditions where oxygen becomes limiting for oxidative phosphorylation, they can rapidly signal to increase cytosolic glycolytic ATP production, while awaiting hypoxia‐induced changes in the proteome mediated by the activity of transcription factors such as hypoxia‐inducible factor 1. Hypoxia is a well‐described phenotype of most cancers, driving many aspects of malignancy. Improving our understanding of how mitochondria change their metabolism in response to this stimulus may therefore elicit the design of new selective therapies. Many of the recent advances in our understanding of mitochondrial metabolic plasticity have been acquired through investigations of cancer‐associated mutations in metabolic enzymes, including succinate dehydrogenase, fumarate hydratase, and isocitrate dehydrogenase. This review will describe how metabolic perturbations induced by hypoxia and mutations in these enzymes have informed our knowledge in the control of mitochondrial metabolism, and will examine what this may mean for the biology of the cancers in which these mutations are observed. WIREs Syst Biol Med 2016, 8:272–285. doi: 10.1002/wsbm.1334Mitochondria are metabolic hubs within mammalian cells and demonstrate significant metabolic plasticity. In oxygenated environments with ample carbohydrate, amino acid, and lipid sources, they are able to use the tricarboxylic acid cycle for the production of anabolic metabolites and WIREs website.For further resources related to this article, please visit the  Mitochondria are a ubiquitous feature of eukaryotic cells, thought to have been incorporated as a core component of our cellular machinery at approximately the same time as the increase in atmospheric oxygen levels, around 1.5 billion years ago.The function of mammalian mitochondria is greatly dependent on an oxygenated microenvironment and a highly regulated complement of metabolic enzymes, some of which are unique within the cell. In the early 1900s, Dr Otto Warburg made the observation that cancer cells produce significant lactate in the presence of oxygen, which led him to the assertion that mitochondrial dysfunction was a root cause of all cancers.+ ratio in the mitochondria.+ ratio in the mitochondria means that in hypoxia, the NADH‐producing reactions of the tricarboxylic acid (TCA) cycle are inhibited  than in normoxia.2.In addition to the direct effects of hypoxia on mitochondrial metabolism, there are also indirect effects as a result of transcriptional changes induced by low oxygen. The initial growth of a cancer results in areas of low oxygen tension found throughout the tumor mass, away from the functional blood vessels. This results in the inhibition of the oxygen‐mediated repression of a small family of heterodimeric transcription factors known as hypoxia‐inducible factors (HIFs). These transcription factors can then move to the nucleus where they bind the p300/CBP [cyclic AMP‐responsive element‐binding (CREB) protein] histone acetyl transferases to decondense chromatin and transcribe their target genes.PDK1).Since its discovery, HIF1 has been shown to regulate a number of transcripts that can directly and indirectly modulate mitochondrial metabolism. Indeed, HIF1 expression in hypoxia has been shown to be central for continued viability.Loss of PDC activity has been shown to result in a change in the citrate to αKG ratio in the cell, which has been suggested to be a prerequisite for a change in the way in which glutamine is metabolized: inducing an increase in the use of reductive carboxylation of this amino acidCOX4‐1 and COX4‐2.Further HIF1‐dependent modification of mitochondrial metabolism in hypoxia has been reported through subunit switching of complex IV  of the respiratory chain. COX is a homodimer with 13 subunits per monomer, which sits within the mitochondrial inner membrane.−/− mouse have shown that hypoxia may induce other changes in mitochondrial metabolic activity, independently of HIF1.The major hydroxylase that determines HIF1α stability is PHD2,FH and SDH are bone fide tumor suppressor genes, inactivating mutations in which have been identified as causative in cancers such as renal clear‐cell carcinoma and paraganglioma.IDH1 and IDH2 are common in a variety of diverse cancers, including adult gliomasFH and SDH, are genetic oncogenes. A single hit, which is both loss of function and gain of function, is only ever observed in these genes. In both gliomas and AML, mutations in IDH genes have been suggested as a very early, and perhaps founder mutations, although in neither disease does IDH mutation appear to be able to induce transformation on its own.SDH, FH, and IDH2) or their metabolic activity directly affects that of the mitochondrion (IDH1). In addition, the cancer‐associated mutations observed have all been reported to interact with the HIF system; in the case of FH and SDH mutations, these unequivocally result in HIFα stabilization, whereas in the case of IDH1 and IDH2, it appears that mutation may destabilize hypoxic HIFα stabilization. In the latter case, it would appear that the biological outcome of this is not yet clear. Mutations in these enzymes therefore have a dual outcome on mitochondrial metabolic activity: they both alter HIF1 activity and they directly alter metabolism.The identification of cancer‐associated mutations in the metabolic enzymes such as fumarate hydratase (FH), SDH, and isocitrate dehydrogenase (IDH) has demonstrated that altered mitochondrial metabolism is sufficient to transform some cell types.SDHD were the first to be identified as causative in patients with hereditary paragangliomas and later pheochromocytomas, rare neuroendocrine neoplasms of the chromaffin tissue of the adrenal medulla and the parasympathetic tissue of the head and neck paraganglioma, respectively.SDHD mutations in 2000, mutations in SDHB and SDHC, and more recently, SDHA and SDHAF2 (encoding the protein responsible for FAD incorporation into SDH) have been identified with the same syndrome.SDH is a highly conserved heterotetrameric complex encoded entirely by the nuclear genome. It is responsible for the oxidation of succinate to fumarate in the TCA cycle and the transfer of electrons to ubiquinone, transfer of which is required by complex III to pump protons. Complex II itself is unique in the respiratory chain as the only complex without proton pumping function. The complex consists of two subunits (SDHA and SDHB), which protrude into the mitochondrial matrix, and two hydrophobic subunits (SDHC and SDHD), which anchor the catalytic components to the inner mitochondrial membrane and produce the binding site for ubiquinone.SDH is one of the few enzymes in the TCA cycle that are unique to the mitochondrion, making this compartment the major source of succinate, and the only one in which it can be further metabolized within the mammalian cell. Loss of SDH function through mutation in any one of the subunits results in loss of dehydrogenase activity, succinate accumulation within the cell, and excretion into the extracellular space. The significant increase in succinate concentrations leads to the inhibition of all members of the αKG‐dependent dioxygenase family that have been reported, including histone and DNA demethylases and the PHDs. This produces a hypermethylator phenotype of the chromatinin vitro and in vivo+ reducing activity in the absence of SDH. However, important questions remain—one of the most intriguing being whether cells and tumors bearing loss of function of SDH through mutations in other subunits show the same metabolic phenotype. This is key, as SDHB‐mutated tumors are the only SDH‐mutated tumors result in malignant tumors. One of the few studies to examine the differential effects of deficiencies of different SDH subunits suggested that RNAi‐mediated reduction in the expression of SDHB led to increased mitochondrial ROS production, while this was not recapitulated by similar reduction of SDHA.Although the loss of SDH activity within the mitochondria produces another form of truncated TCA cycle Figure , the sigFH, encoding the proximal downstream enzyme to SDH, is another mitochondrial tumor suppressor gene, the loss of which leads to hereditary leiomyomatosis and renal‐cell cancer (HLRCC).FH is responsible for the hydration of fumarate to form malate, which can then either be oxidized by malate dehydrogenase to form NADH and oxaloacetate or oxidatively decarboxylated by malic enzyme to form pyruvate and NADPH Figure . DeficieFh1−/− kidneys.In addition to the truncation of the TCA cycle and increase in reductive glutamine metabolism that occurs as a result of loss of FH function,Fh1‐deficient cells highlighted a mitochondrial metabolic ‘bypass’ required for viability.Fh1‐deficient cells continue to oxidize glutamine through αKGDH (reducing NAD+ for oxidation by complex I of the respiratory chain) but direct a proportion of the succinyl CoA produced by the subsequent enzymatic step of the TCA cycle, succinyl CoA ligase, through the heme biosynthetic pathwayA bioinformatic analysis of Fh1.Fh1 deficiency.The bioinformatics screen performed on Fh‐deficient cells also highlighted other enzymes that may be synthetic lethal with loss of 2. Mammalian cells express three IDH isoforms  encoded by five genes  in the nuclear genome. IDH1 and IDH2 are reversible, highly homologous (>70%) homodimeric NADP+‐dependent enzymes. IDH3 is an irreversible heterotetrameric NAD+‐dependent enzyme, both genetically and structurally unrelated to IDH1 and IDH2. Interestingly, mutations only in IDH1 and IDH2 have thus far been linked to cancer. The presence of recurrent somatic point mutations in IDH1 was first identified in 12% of all adult glioblastoma tumors by high‐throughput DNA sequencing.IDH1 and IDH2 occur in a high proportion (>70%) of low‐grade (grade II–III) astrocytomas and oligodendrogliomas and secondary glioblastoma.IDH1 and IDH2 have also been found in other diverse cancers including 16–17% of patients with AML,IDH1, AML have been shown to exhibit an approximately equal frequency of IDH1 and IDH2 mutations.IDH enzymes are members of the β‐decarboxylating dehydrogenase family that catalyze the oxidative decarboxylation of isocitrate to αKG and COIDH1‐mutated gliomas have all been reported to have a single‐point mutation within the codon for Arg132. It appears that the removal of the arginine, rather than the substitution of a specific residue, is the critical feature of this mutation, although the most frequent replacement observed is a histidine residue (R132H).IDH2 in gliomas occur at a much lower frequency (0–6%) than IDH1IDH‐mutated tumors, as it is also produced as a minor product by αKG reductase enzymes and is oxidized back to αKG by 2HG dehydrogenases.IDH mutations on members of the αKG‐dependent dioxygenase family of enzymes has also been studied. Much like SDH‐ and FH‐mutated tumors, IDH‐mutated cells and tumors have been shown to exhibit a hypermethylator phenotype through the inhibition of the ten‐eleven translocation (TET) family of DNA demethylases and members of the Jumonji C‐domain histone demethylases through the competitive inhibition of αKG binding by (R)‐2HG.SDH and FH mutations, the effect of (R)‐2HG on PHD activity has been the subject of some controversy. Although an initial report suggested that the PHD enzymes were inhibited by (R)‐2HG production resulting in increased HIF1α protein,IDH1 mutant cells and tumors actively suppress HIFα stabilization through activation of the PHDs is now more compelling. The precise means by which (R)‐2HG results in increased PHD enzyme activity, however, is still not clear. It has been suggested to be through direct use of only the (R) enantiomer by the PHDs as a substrateIDH1 and IDH2, in both glioma and AML, occur early in tumor development and are thought to be mutually exclusive,IDH‐mutated AML, gliomas with these mutations are almost always IDH1‐mutated. This discrepancy has not yet been explored fully, but it is possible that the environment in which each disease develops (such as the extent and severity of hypoxia) and/or a lack of suitable mitochondrial metabolic plasticity may play a role in determining why IDH2 mutations are not observed often in gliomas.Owing to the structural similarity of (R)‐2HG to αKG, the effect of IDH1 mutations, there may be a requirement for IDH2 wild‐type activity in hypoxic IDH1 mutant gliomas. However, a recent paper also showed that IDH1‐mutated cells retained more of their oxidative TCA cycle metabolism than their wild‐type counterparts.IDH1 wild‐type cells increased their dependence on reductive carboxylation of glutamine, IDH1 mutant cells increased their use of oxidative decarboxylation, most likely retaining oxidative ATP generation in these conditions. This is consistent with the evidence that (R)‐2HG inhibits hypoxia‐induced stabilization of HIF1α,IDH1‐mutated cells may not exhibit the HIF‐dependent metabolic response to hypoxia, including changes in the activity of the PDC and complex IV. However, continued oxygen use in hypoxia is likely to create highly challenging conditions in an IDH1‐mutated tumor, as it is likely to further exacerbate the hypoxic microenvironment, potentially leading to increased areas of necrosis. It is important to note that IDH1 mutant gliomas demonstrate improved overall survival compared to their wild‐type counterparts,IDH2‐mutated cells were shown not to exhibit the same alteration in the hypoxia‐mediated mitochondrial metabolic phenotype.IDH1 and IDH2 mutations and therefore their different prevalence in glioma—a highly hypoxic type of tumor.Gliomas are highly hypoxic tumors.SDH‐, FH‐, and IDH‐mutated and hypoxic cells have been shown to become highly dependent on one or more pathways for their survival. These metabolic vulnerabilities therefore represent attractive targets for future therapeutic development.It is thought that the ancestors of mitochondria, perhaps some type of Rhodobacteria, were organisms with a highly plastic metabolism, able to make ATP both in the presence and absence of oxygen. Although our mitochondria are removed from their predecessors by almost 2 billion years, the mutations that we observe in cancer and studies of other mammals have shown us that they retain many of these characteristics. It is also important to note that studies of mitochondrial metabolism are often centered around only one small aspect of their metabolism—the TCA cycle—and ignore other highly significant metabolic pathways for which mitochondria are critical. While classically being considered the TCA ‘cycle,’ it is becoming increasingly clear through studies on perturbed mitochondrial systems that it in fact consists of multiple interconnecting metabolic pathways that permit crosstalk between the mitochondrion and the cytosol. It is only through studies on tumors—highly proliferative cell systems—that we find that the cycle itself is dispensable, where the use of only some specific linear portions of the TCA cycle is required to fulfill the anabolic requirements without significant difficulty. However, it is in adapting to the truncated nature of the TCA cycle that


UV‐B radiation to molecular level processes and their consequences to whole plant growth and development was developed from key parameters in the published literature. Model simulations showed that UV‐B radiation induced changes in plant metabolic and/or photosynthesis rates can result in plant growth inhibitions. The costs of effective epidermal UV‐B radiation absorptive compounds did not result in any significant changes in plant growth, but any associated metabolic costs effectively reduced the potential plant biomass. The model showed significant interactions between UV‐B radiation effects and temperature and any factor leading to inhibition of photosynthetic production or plant growth during the midday, but the effects were not cumulative for all factors. Vegetative growth were significantly delayed in species that do not exhibit reproductive cycles during a growing season, but vegetative growth and reproductive yield in species completing their life cycle in one growing season did not appear to be delayed more than 2–5 days, probably within the natural variability of the life cycles for many species. This is the first model to integrate the effects of increased UV‐B radiation through molecular level processes and their consequences to whole plant growth and development.A process based model integrating the effects of  Integration among various ecological processes and scaling among various levels of organization are inherent in ecology and pose major challenges in understanding the consequences of global environmental problems Levin . AlthougWhile UV radiation has been a natural environmental stress factor for organisms since the pre‐Cambrian era Sagan , it may Although there is considerable research regarding the effects of UV‐B radiation on subindividual and individual plant levels, we used a modeling approach to integrate these processes and to examine how changes in molecular and cellular processes are scaled to effects at the whole plant level. We modeled the function of an individual plant by integrating photosynthetic production, respiration, and resource allocation. We examined a variety of questions that would be difficult to approach through experimental research, including: (1) What are the most advantageous strategies for the plant to optimize its growth and potential fitness? (2) Does UV‐B radiation interact with other environmental factors? (3) What is the effect of midday photosynthetic depression?The plant can be viewed as a system that dynamically balances the resource uptake and use. Plants optimize the resource allocation by investing resources in such a way that maximizes the returns, that is, the growth of organs involved in the acquisition of the limiting resources is promoted  for 10 years 2000–2009, Pullman, Washington, which is a location that is representative of UV‐B radiation for the northern temperate zone. We used UV‐B Langley calibrated data, considered more appropriate than lamp calibrated data for sunny and dry locations UVMRP . UltraviFor the model, the plant was considered to have the following organs: roots (R), aboveground structural organs (S), such as stems, or sheaths and stolons, leaves (L), reproductive organs (Ro), and seeds (Sd).Since the model considers only the plant function, only the carbon content and its use by different plant pools was considered Haefner . As the −1) is directly proportional with the total leaf mass (Enquist and Niklas ML is the leaf mass of the plant (g), k1 is the plant mass photosynthetic production rate multiplier (time−1).Under the assumption that leaves are the only photosynthetic organs, total production , k2 is the leaf area ratio (g m−2) –ML = k2AL, bpd is the slope of the linear photosynthetic capacity decline (time−1), and t is time.Where, −1) is a function of the total production , the maintenance respiration  and the production allocated to/from storage . The total photosynthetic production available for growth  is a function of total plant mass . k3 is the plant mass respiration rate multiplier (time−1).It was considered that maintenance respiration  becomesUnder these assumption, the new growth for a new plant organs  is the conversion efficiency in biomass of photosynthetic production, and kO5, (unitless) is the percent of total photosynthetic production allocated to the growth of plant organs , aboveground structural organs (S), leaves (L), reproductive organs (Ro), and seeds (Sd)), s Bazzaz .For most species, the plant reproduction is associated with a critical plant mass  is the linear increase in photosynthetic production allocation to reproductive parts.Where, tr (time), the interval necessary for reproduction .Thus, the proportion of total photosynthetic production allocated toward fruits and seeds follow the same scenario portrayed in eq. The plant model eqs. kUVB1, is an adjustment factor due to the effects of UV‐B radiation on photosynthesis, kUVB2, is an adjustment factor due to effects of UV‐B radiation on leaf thickness, kUVB3, is an adjustment factor due to the effects of UV‐B radiation on metabolic processes, kL,UVB4, is the conversion efficiency in leaf biomass of photosynthetic production when plant is exposed to increased UV‐B radiation, and kUVB6, is an leaf growth adjustment factor due to the effects of UV‐B radiation on leaf expansion.Where, To simulate the UV‐B radiation effects on the leaf area, we used the Suchar and Robberecht  model thMO,UVB/MO , stems (S), leaves (L), reproductive organs (Ro), and seeds (Sd)) for the scenarios considered.The variables of interest in our model were UV‐B radiation‐induced relative changes in organ biomass: Since we modeled a hypothetical generalized plant, the parameter estimators considered were means calculated for large arrays of species. Therefore, many of these values were obtained from comprehensive plant traits papers (Poorter and Remkes −1) is direct proportional with the total leaf mass , and a and b coefficients were calculated for the maximum value for For the second trend, plant species exhibiting midday depression, we considered a reduction in photosynthesis around the midday resulting in an average daily reduction in photosynthesis of 40%  . For a wide range of species, the conversion efficiencies kO4, to reproductive organs and seeds are 0.71 and 0.65 , stems (S), leaves (L), reproductive organs (Ro), and seeds (Sd)) for the scenarios considered.The variables of interest in our model were UV‐B radiation‐induced relative changes in organ biomass: The parameter values ±25% for the major plant growth model were used in the model sensitivity analysis. For the UV‐B radiation effects on the plant growth and development, the ranges derived for the major model parameters were used for the allowable limits in the model sensitivity analysis. The relative biomass of roots, structural organs, leaves, and mature seeds were measured across the tested model parameters , and the proportion of net production allocated to structural organs and leaves biomass. The measured variables were moderately sensitive to the decline in leaves photosynthetic capacity in time, the proportion of net production allocated to roots, and the speed of reallocation of resources from vegetative biomass toward the reproductive biomass. The relative biomass of roots, structural organs, leaves, and mature seeds were somewhat or not influenced by changes in conversion efficiency of net production for any plant component. Only seed biomass was influenced by changes in the time required for reproduction. Seed biomass was relatively more sensitive than root, shoot, and leaf biomass to changes in decline in leaves photosynthetic capacity with age, and allocation ratio toward roots and reproductive organs.The relative biomass of roots, structural organs, leaves, and mature seeds were highly sensitive to UV‐B radiation induced changes in photosynthetic production and metabolism, but not very sensitive to increases in conversion efficiency to leaf biomass due to supplemental metabolic investment in secondary metabolites. The effects of UV‐B radiation on leaf expansion were previously analyzed in Suchar and Robberecht .Overall the model is highly sensitive to the variation in parameters. If species‐specific data were used instead, the sensitivity analysis would have been conducted for combinations of parameters, and smaller deltas. But since the model was parameterized with averaged data over multiple species, farther sensitivity analysis at this point was considered unnecessary.Results from meta‐analysis studies of the effects of UV‐B radiation on plant characteristics were used in the calibration and validation process  increased UV‐B radiation in different periods of the growing season, (2) increased UV‐B radiation in combination with different epidermal absorption spectra and UV‐B radiation induced DNA lesions repair rates, (3) plants growing under three temperature regimes under increased UV‐B radiation, (4) effects of expedited/delayed reproduction on plant growth and reproduction under increased UV‐B radiation, and (5) effects of midday photosynthetic depression in plant growth under increased UV‐B radiation. To investigate these scenarios, the relative changes in maximum roots, structural organs, leaves, and mature seeds biomass under ambient, 1.5X and 2X ambient UV‐B radiation regime were recorded.The sensitivity analysis indicated that increased UV‐B radiation may decrease net production, resulting from either increased metabolic rates or reduced photosynthetic rates. Decreases in the conversion efficiency in leaf biomass, due to increased production of secondary metabolites, had no significant influence on the vegetative parts and mature seeds biomass. Also, our model showed that increased UV‐B radiation decreased the biomass of mature seeds, which suggested the probability of reproductive timing shifts in plants as a response mechanism.Increased UV‐B radiation in different periods of the growing season simulations showed that plants are more vulnerable to radiation stress in the first part of the growing season, and less sensitive to increase UV‐B radiation in the second part of the growing season Fig. . With fiSimulations of increased UV‐B radiation in combination with different epidermal absorption spectra and CPD repair rates showed that increased metabolism was responsible for significant decreases in vegetative biomass and the biomass of mature seeds. The latter was slightly more affected by exposure to UV‐B radiation Fig. . SpeciesSimulations of the combined effects of temperature and increased UV‐B radiation, showed that the effect of increased UV‐B radiation effect is confounded with the effects of low temperatures within the range of temperatures considered Fig. . The decSimulations on reproductive timing under increased UV‐B radiation showed maximum delay in the vegetative biomass of about 5 and 15 days for plants exposed to 150% and 200% UV‐B radiation, respectively Fig. . These dOur simulations suggested that supplemental production of secondary metabolites leads to nonsignificant changes in plant biomass. It was suggested that supplemental investment in secondary metabolites might be a significant drain on the plant resources, and inevitably will affect growth  matched pair experiments with combinations of low and high UV‐B radiation levels  that showed essentially no increased UV‐B radiation effect at low temperatures, and significant growth inhibitions at higher temperatures .We recognize that some of the parameters estimated were derived from unduplicated research, and research that simulated unrealistic conditions. Also, we recognize that the noninclusion of the regulation of plant morphology by UVR8 pathway and SIMR hinders the model predictive power. But this can only be considered when the quantitative relationship between UV‐B radiation dose and photomorphogenic responses is better understood. Moreover, species specific model parameter estimates are necessary. We believe that the direction of the enhanced UV‐B effects are essentially correct, although the presented magnitude of the effects may not be precise. Because of the model framework, we can continue to refine the model as new relevant research becomes available for greater understanding of how UV‐B radiation affects organisms.Our model is the first to integrate the effects of increased UV‐B radiation through molecular level processes and their consequences to whole plant growth and development. We modeled the effects of UV‐B radiation at molecular level, and proposed the possible mechanisms that lead to the observed whole plant dynamics. Enhanced UV‐B radiation significantly inhibited plant growth by delaying leaf expansion processes and increasing plant metabolic rates and/or reducing the photosynthesis rate. The costs of effective epidermal UV‐B radiation absorptive compounds did not result in any significant changes in plant growth, but any associated metabolic costs can effectively reduce the potential plant biomass. The model showed significant interactions between UV‐B radiation effects and temperature and any factor leading to inhibition of photosynthetic production or plant growth during the midday, but the effects were not cumulative for all factors. Vegetative growth was significantly delayed in species that do not exhibit reproductive cycles during a growing season, but vegetative growth and reproductive yield in species completing their life cycle in one growing season did not appear to be delayed more than 2–5 days, which is probably within the natural variability of the life cycles for many species. A review of the relevant literature showed a wide range of values for the key parameters. Moreover, certain parameter values were inferred only from the calibration process. However our model allowed the testing of several to examine a variety of questions that were difficult to approach through experimental research.None declared.