Since the introduction of highly active antiretroviral therapy (HAART) in the 1990s, liver disease is emerging as a major cause of morbidity and mortality among HIV-infected patients. This is attributed to a variety of factors, including HAART hepatotoxicity, coinfection with hepatitis B and C virus , and alcohol abuse. Several studies have examined the effects of HAART and HCV/HBV coinfection on liver toxicity. However, the impact of alcohol consumption as a cofactor for hepatotoxicity in HIV patients is only beginning to be understood. Similar to the general population, alcohol use is common in the HIV population but is often overlooked by health care providers. Approximately 25 percent of recently diagnosed HIV patients are alcohol dependent; moreover, alcohol dependence has been associated with HIV treatment failure. Alcohol/HAART interactions appear crucial for the development of liver disease in HIV patients. Recent research has shown that alcohol abuse is associated with severe hepatotoxicity in patients on HAART. Importantly, alcoholic- and HAART-induced liver disease share many potential mechanisms of injury, including altered metabolism of certain signaling molecules  and dysfunction of some cell components . In the era of highly active antiretroviral therapy (HAART), people who are infected with human immunodeficiency virus (HIV) live longer and are less likely to die of acquired immundeficiency syndrome (AIDS)-defining illnesses.The increasing problem of liver disease in the HIV population can be attributed to a variety of factors, including coinfection with HCV or hepatitis B virus (HBV), alcohol abuse, and toxic effects of the HAART medications on the liver . For example, depending on the specific combination of medications used, up to 30 percent of patients experience severe hepatotoxicity after initiation of their HAART treatment, as indicated by at least a fivefold elevation of liver enzyme levels in the bloodThe This article explores the interactions of HIV infection, HAART, and alcohol abuse in the development of liver disease in HIV-infected patients, both with and without coinfection with hepatitis viruses. It also describes some of the potential mechanisms through which alcohol abuse and HAART may cause liver damage.A substantial portion of HIV-infected people also suffer from hepatitis caused by viral infection, primarily HCV, owing to similar modes of transmission. The prevalence of HCV coinfection varies depending on the route of HIV transmission, reaching 85 to 90 percent in people infected through intravenous drug abuse. HIV and HBV coinfection also has been reported, although it is less prevalent then HIV/HCV coinfection (10 to 15 percent). Considerable evidence suggests that people with HIV and HCV coinfection have poorer outcomes than patients with either infection alone . A recenNucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), which inhibit the formation of viral DNA by incorporating into the newly formed DNA molecules, thereby preventing further elongation of those molecules;Nonnucleoside reverse transcriptase inhibitors (NNRTIs), which bind to the enzyme that synthesizes the viral DNA  and interfere with its activity; andProtease inhibitors (PIs), which disrupt the assembly of new virus particles by preventing the activity of an enzyme  necessary for generating the necessary proteins from precursor molecules.Treatment of HIV infection and AIDS is complicated by the fact that the virus can rapidly adapt to the presence of antiretroviral drugs, resulting in resistance to those drugs. To prevent or delay resistance development, clinicians therefore are using a regimen consisting of a combination of several types of antiretroviral drugs that target different stages in the lifecycle of the virus. Such regimens are called highly active antiretroviral therapy (HAART). Drug types that are most commonly used in these combination regimens include the following:However, additional types of drugs have been developed or are under investigation to extend the treatment options available to HIV-infected patients.Most HAART regimens consist of at least three drugs from at least two different drug classes . Although HAART offers effective treatment for extended periods of time for many patients, these regimens have some serious disadvantages. First, they can be complicated and patients often have to remember to take different pills at specific times throughout the day. Not strictly adhering to the dosing schedule increases the likelihood that the virus can become drug resistant and the infection progresses. In addition, the different agents can cause serious side effects, such as hepatotoxicity, particularly when taken in combination. Nevertheless, HAART, to date, is the most effective treatment available to patients with HIV infection or AIDS.HIV patients with concurrent HCV-related hepatitis likely are uniquely susceptible to alcohol’s harmful effects on the liver. In patients with HCV infection alone, alcohol consumption is associated with liver disease progression . In contStudies evaluating the effects of alcohol consumption on the progression of liver disease in people infected with HIV (but not HCV) in the era of HAART are limited. Two recent observational studies  evaluatiIn the other study, Another clinically noteworthy aspect that emerged from this study is that although alcohol abuse is prevalent, it is not adequately assessed by health care givers, particularly in patients infected only with HIV. This finding is highly relevant because effective behavioral and pharmacologic interventions for alcohol dependence are available . FurtherAlthough it is widely recognized by the medical community, there has been little study done on hepatotoxicity caused by medications used in HAART, and the underlying mechanisms remain obscure. In most cases, hepatotoxicity induced by these agents has been identified on the basis of elevated blood levels of certain liver enzymes  in association with increased lactate levels.Alcohol/HAART interactions are emerging as critically important factors influencing liver function. For example, in alcohol-abusing patients with compromised liver function, appropriate dosing of HAART medications becomes difficult because the liver also metabolizes some of these medications. Accordingly, liver dysfunction may lead to harmful accumulation of some HIV drugs if doses are not adjusted properly. Although there is a paucity of drug interaction studies evaluating the effect of alcohol abuse on HAART, a few studies have documented an increased risk of HAART-induced hepatotoxicity in alcohol-abusing patients, particularly those with HCV coinfection . Other sCytokines are small signaling molecules released by certain immune cells that act on nearby cells, thereby influencing the function of those cells . One important inflammation-inducing  cytokine is called tumor necrosis factor-α (TNF-α); its main role is to regulate the actions of various immune cells, thereby contributing to such processes as inflammation and cell suicide . Because of its effects, the production of TNF-α normally is tightly regulated in the body and induced only in response to certain stimuli. The overwhelming majority of TNF-α found circulating throughout the body is produced by a type of immune cell called a monocyte that circulates in the blood. More than two decades ago, researchers described dysregulation of TNF-α production in patients with ALD . The resProduction and/or activity of several different cytokines are dysregulated in people with HIV infection or AIDS. Particularly, proinflammatory cytokines like TNF-α, interleukin (IL)-1 and IL-6, as well as anti-inflammatory cytokine IL-10 play major roles in HIV pathogenesis . The typAmong the proinflammatory cytokines elicited by HIV, TNF-α has assumed a prominent role in our understanding of host–virus interactions . BesidesIn all organisms, proteins that are defective or no longer needed are removed from the cell. To a large extent, this removal occurs at small organelles found in the cell called proteasomes; another pathway involves cell structures called lysosomes. In the proteasomes, specific enzymes  mediate a chemical process known as proteolysis. The proteins that are to be eliminated at the proteasome are marked for destruction by the addition of a small molecule called ubiquitin to differentiate them from proteins that still are needed and must not be degraded. Both excessive alcohol use and HAART can affect proteasome function.The ubiquitin–proteasome pathway likely plays an etiologic role in the development of several forms of toxin-induced liver injury, especially ALD . Early cSeveral reports have indicated that one type of medications included in HAART—the protease inhibitors (PIs)—can cause proteasome dysfunction and changes in body composition and particularly fat metabolism . Initial studies with the PI ritonavir showed that it inhibited certain components of proteasomal activity . SubsequOne way through which proteasome inhibition by PIs can contribute to liver damage involves a regulatory molecule called sterol regulatory element–binding protein (SREBP)-1. This protein, which helps regulate the activity of certain genes in a cell’s DNA, normally is degraded by the proteasomes. If ritonavir impairs proteasome function, SREBP-1 may accumulate in the cell nucleus, which in turn may lead to excessive activity of the genes normally regulated by this protein . SREPB-1Mitochondria are small, membrane-enclosed structures that often are referred to as the cell’s power plants because most of the cell’s energy-carrying molecules are generated in these organelles. This energy production occurs in a series of chemical reactions collectively called an electron transport chain or “respiratory chain” because some of the reactions require the presence of oxygen. However, some of the electrons passing through these reactions also interact with inappropriate oxygen-containing molecules, resulting in the formation of so-called reactive oxygen species (ROS) that can interact with and damage many other molecules  in the cell. To prevent this ROS-induced damage, the mitochondria contain several antioxidant defense mechanisms, such as a molecule called reduced glutathione (GSH) and certain enzymes that can break down ROS. A state in which ROS levels are increased and antioxidant levels are decreased is referred to as oxidative stress.Excessive alcohol consumption has a variety of effects on mitochondrial structure and function, particularly in the liver where the vast majority of ingested alcohol is metabolized. The most obvious of these effects are structural changes in the organelle typified by the appearance of megamitochondria in the livers of patients with ALD . In addiAs a consequence of alcohol-related increases in ROS levels and impaired antioxidant defenses, some of the ROS likely react with mitochondrial proteins and mitochondrial DNA (mtDNA), leading to the formation of abnormal or dysfunctional molecules called adducts. The ROS and adducts, in turn, can affect the membrane surrounding the mitochondria, allowing smaller molecules to leak out of the mitochondria in a process called mitochondrial permeability transition (MPT), which can lead to hepatocyte apoptosis .Finally, studies investigating alcohol’s effects on the entirety of all mitochondrial proteins  have demonstrated that a large number of mitochondrial proteins undergo changes in abundance in response to excessive alcohol exposure . TogetheIn patients receiving HAART, mitochondrial toxicity is closely associated with the use of one type of medications called nucleoside reverse transcriptase inhibitors (NRTIs). In addition to inhibiting the enzyme that helps the virus multiply its genome , these agents also inhibit an enzyme called mitochondrial DNA polymerase γ, which replicates mitrochondrial DNA (mtDNA) . MoreoveDifferent NRTIs differ in their ability to inhibit mitochondrial DNA polymerase γ as shown by reduced mtDNA levels; moreover, the extent of the inhibition is closely correlated with observed clinical pathologies . For exaInhibition of DNA polymerase γ by NRTIs causes a reduction of mtDNA levels, potentially leading to a dys-regulation and an imbalance between those components of the respiratory chain that are encoded by the mtDNA and those that are encoded by the DNA in the cell nucleus. This dysregulation is thought to cause defective electron transport and increase the oxidative stress in the mitochondria. This stress further damages the mtDNA, ultimately leading to cumulative damage to the mitochondrial genome.Since the introduction of HAART in the mid-1990s, the life expectancy of patients with HIV has improved significantly. In some HIV patients, however, an increase in morbidity and mortality has been observed that can be attributed to discontinuation of HAART because of hepatotoxicity. This is especially true in patients who are coinfected with HCV/HBV or have other cofactors predisposing to liver disease, such as alcohol abuse. Alcohol consumption is prevalent in the HIV-infected population and is not only associated with decreased HAART adherence and decreased HIV suppression but also increased risk of HAART-induced hepatotoxicity. Further, alcohol problems often are missed by health care providers. Therefore, routine screening and counseling of HIV patients regarding alcohol problems should become a part of the standard of care to minimize disease progression and hepatic toxicity.To date, the mechanisms underlying HAART hepatotoxicity in association with alcohol consumption or other cofactors have received limited attention, but it is clear that both alcohol and HAART can adversely affect the same cellular targets . For patients experiencing alcohol- or HAART-induced liver disease, there currently is no accepted therapeutic intervention except for abstinence and HAART discontinuation. Thus, there certainly is a clinical need for studies that will help define mechanisms of HAART hepatotoxicity, especially in association with alcohol consumption, and which evaluate potential therapeutic interventions. For example, researchers need to examine the combinatorial effects of PIs and alcohol on the proteasome and its functionality, as well as the effects of NRTIs and alcohol on the respiratory chain, the various electron transport complexes, and the integrity of mtDNA in hepatocytes.


Acupuncture is currently gaining popularity as an important modality of alternative and complementary medicine in the western world. Modern neuroimaging techniques such as functional magnetic resonance imaging, positron emission tomography, and magnetoencephalography open a window into the neurobiological foundations of acupuncture. In this review, we have summarized evidence derived from neuroimaging studies and tried to elucidate both neurophysiological correlates and key experimental factors involving acupuncture. Converging evidence focusing on acute effects of acupuncture has revealed significant modulatory activities at widespread cerebrocerebellar brain regions. Given the delayed effect of acupuncture, block-designed analysis may produce bias, and acupuncture shared a common feature that identified voxels that coded the temporal dimension for which multiple levels of their dynamic activities in concert cause the processing of acupuncture. Expectation in acupuncture treatment has a physiological effect on the brain network, which may be heterogeneous from acupuncture mechanism. “Deqi” response, bearing clinical relevance and association with distinct nerve fibers, has the specific neurophysiology foundation reflected by neural responses to acupuncture stimuli. The type of sham treatment chosen is dependent on the research question asked and the type of acupuncture treatment to be tested. Due to the complexities of the therapeutic mechanisms of acupuncture, using multiple controls is an optimal choice. Acupuncture is an ancient East Asian healing modality that has been in use for more than 2000 years. Together with herbal medicine, it is regarded as one of the two most pivotal medical skills in East Asian medicines. In the last decades, acupuncture has gained great popularity as an alternative and complementary therapeutic intervention in the western medicine . An estiAbundant evidence from animal studies has demonstrated that acupuncture stimulation can facilitate the release of certain neuropeptides in the central nervous system (CNS), eliciting profound physiological effects and even activating self-healing mechanisms , 7. StudConverging evidence from fMRI studies on acupuncture at commonly used acupoints have revealed significant modulatory effects at widespread cerebrocerebellar brain regions. These regions process information in circuits that can broadly be assumed to engage endogenous antinociceptive limbic networks as well as higher-order cognitive and affective control centers within the prefrontal cortex and medial temporal lobe –20. ResePrevious neuroimaging studies on acupuncture focus mainly on the spatial distribution of brain activities induced by acupuncture stimuli. Interest in exploring what happens in the human brain when subjects do not perform cognitively demanding tasks has increased in the past few years. Some researchers indicated that even in the task-free state, the brain continuously expends a considerable amount of energy, and external tasks only modestly modulate the effects of such ongoing activity –23. TherAbundant clinical reports have indicated that acupuncture can provide relief even beyond the time it is being performed. Psychophysical analysis from Price et al. suggests that the analgesic effects of acupuncture might actually peak long even after the needling session is terminated . AnotherRecently, our group has applied data-driven methods, such as the change-point approach with a hierarchical exponentially weighted moving average (HEWMA) analysis to model such slowly varying processes of acupuncture, of which the onset time and durations of underlying psychological activity were uncertain . Our resAcupuncture is a procedure in which fine needles are inserted into an individual at discrete points and then manipulated, with the intent of relieving pain. Clinical observations have shown that acupuncture analgesia is very effective in treating chronic pain, helping from 50% to 85% of patients (compared to morphine which helps only 30%). The analgesic effect of acupuncture is not a simple reflection or linear readout of incoming sensory information but can be substantially influenced by variations in individual physiological states. This inference can partially explain why the analgesic effect of acupuncture is generally characterized by tremendous interindividual variability. The existence of psychological factors in acupuncture analgesia when treating a patient's chronic pain is not unexpected, as with many medical treatments. There is still high skepticism whether acupuncture analgesia is predominately attributable to its physiological or just only psychological action. In the majority of randomized controlled trials (RCTs), it is generally concluded that acupuncture relevantly reduces pain but not more than a credible placebo procedure –37. One μ-opioid receptor (MOR) binding availability in chronic fibromyalgia pain patients [Distinct from the classical senses, pain is multifaceted and generally involves sensory, affective, and autonomic drive dimensions. The subjective evaluation of one's condition  generally involves several complicated cognitive processes, which can be easily biased by previous experience and expectation . In thispatients . They suIn clinical settings, acupuncturists focused on “deqi” feeling during the needling treatment. This sensation was generally experienced by the patients and also by manipulating feeling of the acupuncturist when reaching the level of “qi” in the body. Deqi has recently drawn the attentions of many scientific researchers, and some studies propose that no appreciable therapeutic effect is obtained under a certain stimulation level, which is determined by the appearance of a particular sensation known as deqi –44. One Given that deqi plays a pivot role in the therapeutic effect of acupuncture, it is noteworthy to find the relations between the brain activities and acupuncture-induced feelings. One study showed that acupuncture-induced deqi sensations without sharp pain primarily elicited widespread signal decreases in several brain areas, including the frontal pole, VMPF cortex, cingulated cortex, hypothalamus, reticular formation, and the cerebellar vermis, whereas sharp pain elicited signal increases in several areas, including the frontal pole and the anterior, middle and posterior cingulate . They fuSelecting the study design for both clinical and study investigations is prerequisite to answering the research question of interest whether acupuncture really works compared with control group. Thus, the central question is whether a particular acupoint needling manipulation performs better than another prescription, which is generally designed to determine an intervention's effectiveness compared to placebo in clinical trials. However, it is not known which aspects of the acupuncture treatment, such as the mode of stimulation or location of the acupuncture point, are specific to produce these physiological effects. The majority of neuroimaging researchers have suffered from selection of appropriate control challenges in order to address both the specific effect and relative effectiveness of acupuncture. There existed several control modalities. One approach is to apply the retractable nonpenetrating sham needle , which gMost of neuroimaging studies generally adopted the GLM analysis to focus on the spatial distribution of acupuncture-induced neural response to the acute effect of acupuncture. In fact, an acupuncture procedure typically involves two administration steps: (1) needling stimulation in deep tissue with skin piercing and biochemical reaction to tissue damage and (2) prolonged effects after the removal of acupuncture needle stimulation , 31. In  Due to the complexities of the therapeutic mechanisms of acupuncture, research into its neural mechanism has raised a number of difficult methodological issues. Variability in needling technique, deqi sensations, design paradigm, differences in neuroimaging hardware and software, and data postprocessing methods , may allPrevious acupuncture studies have generally adopted the multiblock design paradigm with repeated stimuli during a relatively short-term time span. Since acupuncture-related neural responses can be long lasting and not return to the baseline level immediately after the stimuli terminated, the “on-off” specifications set by block design may be violated; further analysis may be susceptible to errors of statistical significance . In bloc


Tumorigenesis is often described as a result of accumulated mutations that lead to growth advantage and clonal expansion of mutated cells. There is evidence in the literature that cancer cells are influenced by the microenvironment. Our previous studies demonstrated that the mouse mammary gland is capable of redirecting mouse cells of non-mammary origins as well as Mouse Mammary Tumor Virus (MMTV)-neu transformed cells toward normal mammary epithelial cell fate during gland regeneration. Interestingly, the malignant phenotype of MMTV-neu transformed cells was suppressed during serial transplantation experiments. Here, we discuss our studies that demonstrated the potential of the regenerating mouse mammary gland to redirect cancer cells of different species into a functional tumor-free mammary epithelial cell progeny. Immunochemistry for human specific CD133, mitochondria, cytokeratins as well as milk proteins and FISH for human specific probe identified human epithelial cell progeny in ducts, lobules, and secretory acini. Fluorescent In Situ Hybridization (FISH) for human centromeric DNA and FACS analysis of propidium iodine staining excluded the possibility of mouse-human cell fusion. To our knowledge this is the first evidence that human cancer cells of embryonic or somatic origins respond to developmental signals generated by the mouse mammary gland microenvironment during gland regeneration  Tumorigenesis has been previously described as a complex genetic disease where accumulated mutations and epigenetic changes in a cell can cause the activation of oncogenes, inactivation of tumor suppression genes and deregulation of stability genes ,2. AccumDean Felsher previously discussed a model where tumorigenesis is the result of the accumulation of genetic alterations that occur only if the mutated cells are in the context of a tumor-permissive microenvironment . Studiessrc, the non-receptor protein tyrosine kinase that mediates the Rous sarcoma virus’s activity, demonstrated that the infected cells acquired foci formation potential and anchorage independent growth, typical characteristics of transformed cells . M. M21]. MCell-cell fusion is a biological event that can occur in somatic cells such as myoblasts and macrophages during tissue development and regeneration . As discin vivo [in situ hybridization (FISH) for the presence of the Y chromosome of chimeric outgrowth tissue sections showed that male (NT2 cells) and female (mouse) cells existed side by side in mammary epithelial structures [Evidence suggests that human-mouse cell fusion does not occur in our experiments . First oin vivo ,36,43,44in vivo ,36,43,44ructures . Similarructures . Furtherructures . in vivo [Although some tumors have been demonstrated to derive from clonal expansion, it is becoming clear that most tumors comprise heterogeneous cell populations that are at different stages of self-renewal, proliferation and differentiation potential ,46,47,48in vivo . + expression have higher tumor promoting ability relative to CD44 depleted breast cancer cells possibly due the MAP kinase and PI3 kinase/AKT signaling cascades activation which subsequently increase cancer cell invasion, growth, motility, and survival [The results that human cancer cells of both embryonic or somatic origin were able to respond to the differentiating signals of the regenerative mammary niche independently from their differentiation state and metastatic potential, leads us to the hypothesis that tumor initiating cells retain the potential to be redirected towards a normal phenotype when placed in a permissive microenvironment such as the regenerative mammary gland. It has been shown that the breast cancer cells enriched for CD44survival ,51. Expesurvival . Howeversurvival . Most imsurvival . These fsurvival . in vitro for six passages and transplanted in the cleared fat pad of Nu/Nu mice without normal mammary epithelial cells suggested that cancer cells retained their tumor -initiating ability in the absence of a normal regenerating niche [One question that still remains unanswered is whether the normal niche terminally reprograms or just temporary redirects cancer cells to a normal phenotype. Experiments where erbB2 expressing cells were recovered by magnetic sorting from the secondary MMTV-neu chimeric outgrowths that were dissociated and cultured ng niche . It was ng niche . Howeverng niche .in vivo.Interestingly, experiments where cancer cells were mixed at higher density than normal MECs and subsequently transplanted in the cleared fat pads of athymic nude mice gave evidence that tumor suppression is dependent on the interaction of human cancer cells with normal mammary epithelial cells . PresumaOngoing experiments are further investigating the mechanism through which the normal microenvironment suppresses tumorigenesis and if the tumor cells can be terminally reprogrammed to a normal phenotype. in vivo. The resulting interaction with the mouse mammary niche leads to the redirection of human cancer cell progeny to adopt a human mammary epithelial cell phenotype with an absence of tumorigenic activity. Interestingly, our findings provide direct evidence that the developmental cues in the mouse mammary gland and those present during human breast development may be interchangeable. It was shown for the first time that human cancer cells either from an embryonic origin or a somatic origin can be redirected to a tumor-free phenotype and produce progeny capable of mammary epithelial cell functions upon the interaction with a developing tissue i.e., luminal, myoepithelial, alveolar during chimeric mammary regeneration. Interestingly, even human cancer cells that lack of estrogen or progesterone receptor expression behave as hormonal responsive cells and secret human-specific milk proteins into the lumen of lactating hosts. We observed that human cancer cells proliferated independently in the formation of primary and secondary chimeras as shown by the absence of human/mouse cell fusion in the chimeric outgrowths as determined by FISH and propidium iodide. Overall our findings indicate that human cancer cells contain a subpopulation of cells that have multipotency and self-renewal potential independently from the tumor differentiation or metastatic stage and are responsive to signals from the mouse mammary microenvironment. It was demonstrated that human cancer cells give rise to a cell progeny that can differentiate into distinct mammary epithelial cell types, in situ. Currently, we are investigating which components present within normal mouse mammary tissues have the potential to redirect tumorigenic cells to normal cell function. Overall these findings suggest a significant amount of crosstalk between the tissue microenvironment and cancer cells and have identified a characteristic of human cancer cells that results in suppression of the malignant phenotype and in a response to “normal” developmental cues.Previously, evidence was provided for the existence of mammary epithelial stem/progenitor cells in the mouse mammary gland that are distinguished by their lobule-limited and duct-limited epithelial morphogenetic potential ,52,53,54


Neuro-immune alterations in the peripheral and central nervous system play a role in the pathophysiology of chronic pain, and non-coding RNAs – and microRNAs (miRNAs) in particular – regulate both immune and neuronal processes. Specifically, miRNAs control macromolecular complexes in neurons, glia and immune cells and regulate signals used for neuro-immune communication in the pain pathway. Therefore, miRNAs may be hypothesized as critically important master switches modulating chronic pain. In particular, understanding the concerted function of miRNA in the regulation of nociception and endogenous analgesia and defining the importance of miRNAs in the circuitries and cognitive, emotional and behavioral components involved in pain is expected to shed new light on the enigmatic pathophysiology of neuropathic pain, migraine and complex regional pain syndrome. Specific miRNAs may evolve as new druggable molecular targets for pain prevention and relief. Furthermore, predisposing miRNA expression patterns and inter-individual variations and polymorphisms in miRNAs and/or their binding sites may serve as biomarkers for pain and help to predict individual risks for certain types of pain and responsiveness to analgesic drugs. miRNA-based diagnostics are expected to develop into hands-on tools that allow better patient stratification, improved mechanism-based treatment, and targeted prevention strategies for high risk individuals. Human chronic pain disorders are bio-psycho-social diseases, which are difficult to treat due to their diversity. Chronic pain syndromes that develop after nerve damage, trauma or surgery are characterized by persistent and severe pain; they induce anxiety and depression and greatly impair patients’ quality of life. One out of five Europeans suffers from chronic pain with most reporting that they endure it for more than two years . Due to Of the painful neuropathies, the most frequent, painful diabetic polyneuropathy is a common complication of diabetes mellitus occurring in up to 20% of patients . Good glVarious diseases, including neuropathic pain disorders, reveal unique miRNA expression signatures that can be exploited as diagnostic and prognostic markers. Recent reports on miRNA modulation of both neuronal and immune processes further predict therapeutic potential for manipulating disease-modified miRNAs in diseases affecting both the immune system and brain function, such as neuropathic pain disorders, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and anxiety-related disorders .Figure 1). These “neurimmiRs” primarily target transcription factor genes or other regulatory genes, which enables simultaneous modulation of both immune and neuronal processes including cognition through direct or indirect alterations of neuron–glia or brain-to-body signaling . National and international guidelines differ in their recommendations about first and second line treatment choices. While pregabalin is favored by some , duloxetFigure 2; Both, the novel and specific mode of action and the ability to function as master switches of entire signaling networks has triggered enthusiasm for miRNAs as promising therapeutic targets although relatively little is known about the mechanisms of cellular uptake, storage and mode of action of miRNA modulators . In seveVarious studies have identified signatures of neuroinflammation as critical components of diabetic polyneuropathy  in additInflammatory processes are also activated in the spinal cord upon peripheral nerve injury and involve microglia activation and leakage at the blood nerve barrier along the entire neuraxis , 2012. MDeregulated miRNAs can be a consequence or cause of local inflammatory processes such as regulation of nociceptor sensitisation by controlling phospholipase A2 activation . AnalyseKcna2 potassium channel expression and this has been causally associated with neuropathic pain . miRNA mimics consist of over-expressing specific miRNAs that are reduced in the disease state. This mimic approach could be done by introducing synthetic oligonucleotides  or involve over-expression of such miRNAs from an introduced viral vector. Antagomirs are synthetic oligonucleotide sequences that are designed to be inversely oriented (antisense) to miRNAs that are over-expressed in the disease state and which can form Watson-Crick base pairing with the target miRNA. This can either inactivate a miRNA or result in its degradation. Similar to the miRNA mimics, these therapeutic and research tools can also consist of synthetic or modified nucleic acid sequences or be overexpressed from viral vectors.Manipulating miRNAs as a therapeutic tool presents significant theoretical and practical challenges that must be overcome before this approach becomes a reality. Specific examples involve two of the more straightforward approaches for miRNA modulation, miRNA mimics and antagomirs (Alternative methodologies used in experimental settings include miRNA sponges, which are exogenous DNA repeats of the target sequence and can serve to soak up excess copies of the excess miRNA . The miRAn important difficulty that may be predicted for developing neuronal miRNA therapeutics is delivery, since targeting to the brain involves the significant hurdle of crossing the blood–brain barrier. Nevertheless, therapeutic efficacy of certain approaches such as the use of LNA antagomirs has been demonstrated even in primate models, and certain neuronal miRNA therapeutic approaches are now in preclinical development. These studies cover several creative approaches that have been developed to overcome the delivery problem. Thus, ~20-mer miRNA-size oligonucleotides are indeed unlikely to cross the blood–brain barrier. However, peripheral administration of oligonucleotide controllers of inflammation-regulating miRNAs would change the levels of cytokines, and cytokines can penetrate and affect the brain. Such effects have been demonstrated for miR-132  and miR-Recently, specific miRNAs have been associated with pathological pain and the deregulation of ion channel expression in sensory neurons in rodent pain models . Unique The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The most primitive germ cells in adult mammalian testis are the spermatogonial stem cells (SSCs) whereas primordial follicles (PFs) are considered the fundamental functional unit in ovary. However, this central dogma has recently been modified with the identification of a novel population of very small embryonic-like stem cells (VSELs) in the adult mammalian gonads. These stem cells are more primitive to SSCs and are also implicated during postnatal ovarian neo-oogenesis and primordial follicle assembly. VSELs are pluripotent in nature and characterized by nuclear Oct-4A, cell surface SSEA-4, and other pluripotent markers like Nanog, Sox2, and TERT. VSELs are considered to be the descendants of epiblast stem cells and possibly the primordial germ cells that persist into adulthood and undergo asymmetric cell division to replenish the gonadal germ cells throughout life. Elucidation of their role during infertility, endometrial repair, superovulation, and pathogenesis of various reproductive diseases like PCOS, endometriosis, cancer, and so on needs to be addressed. Hence, a detailed review of current understanding of VSEL biology is pertinent, which will hopefully open up new avenues for research to better understand various reproductive processes and cancers. It will also be relevant for future regenerative medicine, translational research, and clinical applications in human reproduction. However, although male gametes generated from mouse embryonic stem cells in vitro resulted in the birth of pups, most of them suffered epigenetic defects [Stem cells have the capacity to self-renew as well as give rise to differentiated progeny. They have generated a lot of interest amongst the general public as well as the scientific fraternity because of their potential for regenerative medicine. Although this field of research has been associated with a lot of hype, it definitely holds a lot of hope when applied to reproductive health. Considerable research has gone into the differentiation of embryonic stem cells , 2 and e defects . Similar defects  are used defects .in vitro, which when transplanted in busulfan treated mice led to the birth of normal pups. This demonstrated supremacy of the gonadal stem cells differentiated by the in vivo cues over in vitro manipulated ES cells to generate synthetic gametes. White et al. [in vitro as well as in vivo after xenotransplantation in immunodeficient mice.Recently few groups have succeeded in deriving pluripotent ES-like cultures using adult testicular biopsies of mice –9 and hue et al.  recentlyin vitro [per se expand to give rise to ES-like colonies in vitro [in vitro from gonadal tissue biopsy. It was postulated that spermatogonial stem cells (SSCs) undergo dedifferentiation and result in ES-like colonies in vitro , but recin vitro  and ovarin vitro . We propin vitro . Their pin vitro but they do not behave as stem cells in vivo, and later on during fetal development the true stem cell population of SSCs appears in the testis that divides throughout life giving rise to waves of spermatogenesis [in vitro. As evident a lot of misperception exists on our basic understanding of gonadal stem cells. VSELs are the primordial germ cells that migrate into the gonadal ridge during early embryonic development and persist into adulthood, as also suggested by deFelici . Howeverogenesis . Similarogenesis  have alsAn introduction to gonadal stem cells, namely, VSELs and their possible role during premeiotic expansion of germ cells during gametogenesis and their relevance to reproductive and cancer biology are the focus of the present paper. In conclusion, we will summarize the possible translational applications of this emerging and exciting field of research. +, SSEA1+, Sca1+, Lin−, CD45−) were first reported by Ratajczak and group in adult mice tissues [−, CD105−, and CD29−. They are very small in size (3–5 um) and have a large nucleocytoplasmic ratio, large nuclei with abundant euchromatin, and an open chromatin structure for Oct-4 and Nanog promoter [in vitro; however, unlike ES cells, VSELs neither complement during blastocyst development nor form teratomas in immunodeficient mice [+, lin−, CD45− [Pluripotent VSELs . These two populations of stem cells (VSELs and TCSCs) together are responsible in bringing about tissue renewal, homeostasis, and regeneration after injury throughout life and decrease in number with age. The coexistence of two stem cell populations (the more primitive being quiescent and the progenitor being more rapidly dividing) has been recently proposed by Li and Clevers . VSELs ain situ in adult testicular and ovarian tissue collected from prostate cancer patients and perimenopausal women, respectively. These VSELs were localized in the basal layer of cells adjacent to the basement membrane in seminiferous tubules [Our group has demonstrated the presence of VSELs for the first time in their natural somatic niche  tubules  and were tubules . Similar tubules , whereas tubules  and also tubules  by our gOct-4, also designated as Oct-3 or POU5F1, is present as a maternal transcript in mature oocytes and besides being the gatekeeper in the beginnings of mammalian development  and plurPublished literature on Oct-4 in somatic stem cells has confused stem cell researchers –48 becauPresence of Oct-4 positive VSELs in adult gonads and other body tissues contradicts the earlier views proposed by Jaenisch's group , 51 thatIndeed presence of VSELs have confused biologists in several other instances as well; for example, Tilly's group  and Nayedark SSCs (with cytoplasmic Oct-4B). The VSELs possibly give rise to Adark SSCs which in turn undergo clonal expansion as evident by the presence of cytoplasmic bridges between the rapidly dividing cells [We have documented that an adult testis harbors a novel population of pluripotent VSELs (with nuclear Oct-4A) which are more primitive to Ang cells . Oct-4 idark SSCs is easily explained on the basis of stem cell biology. VSELs have abundant open euchromatin and the differentiated cells that arise by asymmetric cell division undergo extensive reprogramming and compaction of chromatin (by DNA methylation) which may result in a dark nuclear appearance, a characteristic of the Adark SSCs [dark SSCs indicating on extensive nuclear reprogramming in the progenitor stem cells which arise by asymmetric cell division from the pluripotent VSELs (with abundant euchromatin).The characteristic dark stained nuclei in Aark SSCs . Chromatdark SSCs and exhibited nuclear staining for 5-methyl cytosine  and also ovarian germ stem cells . The VSELs were smaller than RBCs, had high nucleocytoplasmic ratio, abundant euchromatin, nuclear OCT-4, cell surface SSEA-4 and other pluripotent markers . InteresFigures  . Three-wdark SSCs in the testis and OGSCs in the ovary. Gametogenesis, a process by which haploid gametes are produced from diploid germ cells in the gonads, ensures transmission of genetic information from generation to generation and thus the continuation of species. The primordial germ cells (PGCs) of epiblast stage embryo colonize into the gonadal ridge in the undifferentiated gonad and differentiate into female or male germ cell precursors. These PGCs possibly persist as VSELs in adult gonads and undergo asymmetric cell divisions throughout life to self-renew and give rise to tissue committed gonadal stem cells, namely, AUndifferentiated SSCs maintain a stable diploid population of germ cells and produce differentiating spermatogonia, which finally enter meiosis and give rise to spermatocytes which differentiate and produce sperm throughout life. A comprehensive review on various aspects of self-renewal, proliferation, and differentiation of SSCs was recently published , 57 highdark SSCs undergo regular mitotic divisions whereas Apale   spermatogonia divide only once whereas Ehmcke and Schlatt propose that spermatogenesis starts with the division of a pair of Apale spermatogonia and Adark SSCs divide very rarely. They further suggest that Adark, Apale and B spermatogonia do not form mixed pairs or chains and none of the premeiotic germ cell types undergo unequal divisions. Detection of VSELs in the adult testis adds another dimension to this current school of thought since they are implicated during pre-meiotic expansion of testicular germ cells. Various events like asymmetric cell division, self-renewal, clonal expansion, and proliferation as they occur during spermatogenesis have been further clarified  may be a better cell surface marker to isolate pluripotent ovarian stem cells. A recent report by Byskov and group  found noIntriguingly Byskov et al.  in theirThe stem cells exist in a specialized microenvironment provided by the somatic cells termed as the “niche”. This term was first coined by Schofield in 1978 for the mammalian hematopoietic system  and now An age related reduction in both quality and quantity of sperms in mice and men is possibly because of compromised niche rather than the reduction of stem cell potential , 72. Whein situ [in vitro into oocytes [in vivo [in vitro after being exposed to oncotherapy and also if collected from aged ovaries [in vivo inhibitory cues are withdrawn, the stem cells differentiate into oocytes-like structures, embryos, ES-like colonies, and EB-like structures in vitro, demonstrating their pluripotent nature. This has been a consistent observation not only in case of humans but also in other mammals like rabbit, sheep, and monkey [ Menopause is the age-related cessation of ovarian function indicating the end of fertile phase of a woman's life. The mammalian ovary is believed to be endowed with a fixed number of eggs and a sudden loss of PF results in menopause in women , 75 and in situ , 78. OSE oocytes  and the [in vivo . Estradi ovaries  indirect ovaries  reported ovaries  have shod monkey .in situ (CIS), neoplastic gonadoblastoma, and invasive germ cell tumors in adults [VSELs are the possible precursors to cancer stem cells , 35. It n adults , 86. Coon adults , 88 concThe connection of stem cells (VSELs) with ovarian cancers is based on the published literature and circumstantial evidence but is not yet well accepted by the scientific community. 90% of ovarian cancers  arise from OSE ! Incessant ovulation hypothesis suggests that continuous ovulation (without associated apoptosis) subjects OSE to transformation events and damaged cells are retained leading to cancer . OverexpDerivation of ES-like cultures using adult gonadal tissue from mice and humans has recently been reported. This has resulted in a lot of excitement since adult gonads may be a novel “autologous”, non-embryonic source of pluripotent stem cells in contrast to human embryonic stem cells where issues regarding immune rejection exist during cell-based therapies in future. Moreover, they may also be superior to induced pluripotent stem cells (iPS) since they are derived from a very quiescent stem cell population and are thus “young” cells with long telomeres that could be isolated from an aged body, in contrast to iPS cells which are derived from terminally differentiated somatic skin fibroblasts (with shortened telomeres) that tend to accumulate DNA mutations over time. This is in accordance with the “disposable soma” theory proposed by Kirkwood et al. , which sin vitro expansion of VSELs similar to embryonic stem cells. Attempts in the field have resulted in successful ES-like culture from testicular tissue in mice [However, extensive research needs to be undertaken to establish technology to obtain  in mice –9 and me in mice –13. Thes in mice , 11 afte in mice .Application of VSELs to improve reproductive health needs to be established. We have recently studied the differential effect of busulfan on the relatively quiescent VSELs versus rapidly dividing germ cells in adult mice gonads (unpublished results). The VSELs were found to be resistant to the treatment and this opens up newer and exciting avenues for fertility preservation. The VSELs are localized in OSE and several investigators have reported extensive proliferation in OSE in response to PMSG ; we need


Metabolic syndrome (insulin resistance syndrome) represents a group of physiologic signs that indicate a predisposition to obesity, diabetes, and cardiovascular disease. Consistent with the idea that intolerance to carbohydrate is an underlying feature of metabolic syndrome, we present results showing that a low carbohydrate diet results in global improvement in traditional and emerging markers associated with metabolic syndrome. Control diets, restricted in fat, are shown to be less effective. Recent research results mandate a careful re-evaluation of the widespread belief that dietary saturated fat is harmful. Specifically, multiple recent reports find no association between dietary saturated fat intakes and cardiovascular disease (CVD). There is, however, a consistent pattern of increased risk for both CVD and type-2 diabetes associated with increased levels of saturated fatty acids (SFA) in circulating lipids. This raises the important question as to what contributes to increased levels of saturated fat in the blood? Whereas dietary intake of saturated fats and serum levels of SFA show virtually no correlation, an increased intake of carbohydrate is associated with higher levels of circulating SFA. This leads to the paradoxical conclusion that dietary saturated fat is not the problem; rather it’s the over-consumption of carbohydrate relative to the individual’s ability to metabolize glucose without resorting to de novo lipogenesis. From this perspective, insulin resistant states like metabolic syndrome and type-2 diabetes can be viewed as carbohydrate intolerance, in which a high carbohydrate intake translates to increased serum SFA and therefore increased risk. We all stand to benefit, both now and in the future, if a well-formulated low carbohydrate diet becomes an accepted option in promoting health across many sub-groups in our population.


Compelling evidence suggests that both biological and psychosocial factors impact the process of aging. However, our understanding of the dynamic interplay among biological and psychosocial factors across the life course is still fragmentary. For example, it needs to be established how the interaction of individual factors , behavioral factors , and psychosocial experiences  in perinatal, childhood, and adulthood influence health across the aging continuum. This paper aims to outline potential intersection points serving as an interface between biological and psychosocial factors, with an emphasis on the mitochondrion. Mitochondria are cellular organelles which play a critical role in cellular senescence. Both chronic exposure to psychosocial stress and genetic-based mitochondrial dysfunction have strikingly similar biological consequences; both predispose individuals to adverse age-related health disorders and early mortality. Exploring the interactive nature of the factors resulting in pathways to normal healthy aging, as well as those leading to morbidity and early mortality, will continue to enhance our ability to translate research into effective practices that can be implemented throughout the life course to optimise the aging process. Aging is the inescapable process by which individuals, from the age of about 30 years old onwards, gradually lose maximal functional capacity . Some recompression of morbidity hypothesis [In the past century, we have witnessed significant increases in life expectancy as more individuals live longer , 10. Thipothesis . The incpothesis , changespothesis . ComprehA central question concerning longevity remains: Why do some people live long whereas others die early? Another equally critical question concerns morbidity: Why is aging associated with a greater incidence of almost every categorized disease—including degenerative, metabolic, and malignant disorders? Since disease incidence, mortality, and longevity are all associated terms in the same aging equation, a more general question may be posed: What are the pathways that impact individuals' rate of aging? how psychosocial factors influence cellular aging and translate into aging of the whole organism [While it is well understood that both biological and psychosocial factors impact the aging process, it is still unclear organism . Below iPhysical health and function depends on the coordinated functioning of several organs and physiological systems that allow the organism in dynamic balance to adapt to perpetual environmental challenges. Failure to adapt to challenges  may occur in aging. Thus, senescence-induced loss of cell numbers and/or optimal functioning can result in suboptimal organ function . For thic. elegans [Biological factors influence the aging process. An important constituent of mammalian cells are mitochondria. These dynamic subcellular organelles contain their own circular DNA, are the principal site of cellular adenosine triphosphate (cellular energy currency) synthesis, regulate cell death through apoptotic signalling, and are the major source of reactive oxygen species (ROS) within the cell , 17. One elegans , 27) whe elegans , 29.In contrast, a general role of mitochondria in the aging process is supported by abounding experimental evidence –37. For Further evidence supporting a role of mitochondria in the aging process comes from interventions that influence mitochondrial function. The only intervention capable of extending life span in animals—lifelong caloric restriction —diminishinactivity leads to a reduction in mitochondrial content and function [Like caloric restriction, physical activity and exercise are potent stimuli that increase mitochondrial content and function –57. Physfunction , 62 and function  and enhafunction . The aforementioned physiological dysregulations are more commonly observed in old age. For example, older individuals (63–70 years old) who are sedentary, but not those who are active, have lower mitochondrial content than young individuals . FinallyThe findings outlined in this section are consistent with the notion that biological mechanisms determine the aging process. Additional arguments supporting this notion also exist. They notably include the loss of molecular fidelity with time as the major cause of aging  and the Despite the fact that aging research has generally been dissected using the biological scalpel, psychological and social variables are also important modulators of the aging process associated with mortality –73. For On the other hand, centenarians with engaged lifestyle and certain personality traits  tend to have higher mental health status, a healthy sign of aging, when compared to those who do not possess these traits . A twentPsychosocial factors also have similar effects on more proximal biological indices of aging. Not living with a partner  is associated with accelerated cellular aging, as evidenced by shorter telomere length in blood leukocytes of unmarried middle-aged men and women . Similarα, IL-1β, and TNFα) [As mentioned above, mitochondria influence cellular function , 17 and nd TNFα) . In fact, the mitochondrial DNA sequence contains putative response elements for several hormonal receptors   and someBeyond the direct effects that psychosocial stresses exert on mitochondrial function, psychosocial factors can also influence individual's lifestyles, such as levels of physical activity and inactivity  . For exaPhysical activity has positive effects on mitochondrial function and counteracts inflammatory processes and age-related chronic diseases . It can interactions of biological and psychosocial forces that influence the aging process [not adopting an integrative approach risk being uni-dimensional and thus difficult to apply towards different real-life contexts, where individuals age under the collective influence of factors of different nature.Because mitochondria influence cellular aging and are responsive to stress hormone levels, they are especially well equipped to act as key integrators that synergistically influence biological and psychosocial factors . As desc process . ConclusInterdisciplinarity and even transdisciplinarity  have emeIn this spirit, the aging process is influenced by several interactive forces inherent to the individual  and forces inherent to the psychosocial environment  that continuously and progressively interact over long periods. Aging must therefore be approached from an ontogenic perspective not solely focused on end outcomes  or on the molecular factors predicting these outcomes. Instead, aging research would benefit from being guided by a perspective focused on the changes and interactions among biological and psychosocial processes, which take place across stages of human development throughout the lifespan. The experience-dependent nature of aging has important implications for the research questions that are posed . This suggests that cumulative prenatal, earlylife, young adulthood, and later life circumstances impact pathways to aging. This could be mediated in part by alterations in the stress system across the life course: induced alterations in neurological substrates that signal stressful information , 115 as Epigenetics, which involves the laying of relatively stable imprints on the genome that impact gene expression and cellular function over time , 118, isTaken together, the reviewed literature indicates that an increasing number of biological factors , behavioral and , and psychosocial  factors influence the aging process. The challenge lying ahead of researchers in this field lies in the exploration of the intersection points linking these multiple levels of analysis spanning several disciplines. For example, what physiological processes interact with the psychosocial effects of being married, of meditating regularly, or of experiencing psychological well-being and sense of purpose in life, which ultimately culminate in reduced telomere shortening ? What coEffective strategies for promoting healthy aging will need to be individualized. The perfect individualization of treatment and prevention of age-related disorders may appear as an unattainable utopia at this point in time. This is particularly the case because up until now, our knowledge of the dynamic interplay between the different biological and psychosocial levels of analysis is still fragmentary, which impedes discoveries about the complex processes from which individual-specific pathways of aging emerge. A well-known principle in biology and developmental psychopathology is that of “equifinality,” whereby multiple distinct pathways lead to the same outcome. The reciprocal principle is that of “multifinality,” whereby the same set of pathways lead to different outcomes . LikewisMeans must be developed to distinguish between optimal  and suboptimal  rates/trajectories of aging. From the onset, it can be established that optimal aging is characterized by a slow progressive decline in physiological functions, maintenance of well-being for the majority of the lifespan, and only a short period of very poor physical health leading to death. But what are the biomolecular  sings of optimal adaptation to the passing decades? What are the normative ontogenic trajectories, or healthy biological and physiological signatures of successful aging? Having answers to these questions will enable researchers to more accurately distinguish dysfunction from normal function in different aged organ systems. Ryff, Singer and colleagues have established biological correlates and a conceptual framework aimed at deciphering the biological and psychosocial underpinnings of resilience, positive health, and successful aging , 132–134Thus far, despite the fact that more resources are being invested to study specific aspects of the normal pathways leading to healthy aging , 132–134In conclusion, as a rejoinder to the question “What are the pathways that impact individuals rate of aging?”, we ought to answer that there are surely several different pathways to healthy aging. These pathways must depend not on singular factors acting independently, but on interactive forces among multiple levels of function operating in synergy , includi


Both the concept of ‘brain-sparing’ growth and associations between relative lower limb length, childhood environment and adult disease risk are well established. Furthermore, tibia length is suggested to be particularly plastic under conditions of environmental stress. The mechanisms responsible are uncertain, but three hypotheses may be relevant. The ‘thrifty phenotype’ assumes that some components of growth are selectively sacrificed to preserve more critical outcomes, like the brain. The ‘distal blood flow’ hypothesis assumes that blood nutrients decline with distance from the heart, and hence may affect limbs in relation to basic body geometry. Temperature adaptation predicts a gradient of decreased size along the limbs reflecting decreasing tissue temperature/blood flow. We examined these questions by comparing the size of body segments among Peruvian children born and raised in differentially stressful environments. In a cross-sectional sample of children aged 6 months to 14 years (n = 447) we measured head circumference, head-trunk height, total upper and lower limb lengths, and zeugopod (ulna and tibia) and autopod (hand and foot) lengths.Highland children (exposed to greater stress) had significantly shorter limbs and zeugopod and autopod elements than lowland children, while differences in head-trunk height were smaller. Zeugopod elements appeared most sensitive to environmental conditions, as they were relatively shorter among highland children than their respective autopod elements.The results suggest that functional traits  may be partially protected at the expense of the tibia and ulna. The results do not fit the predictions of the distal blood flow and temperature adaptation models as explanations for relative limb segment growth under stress conditions. Rather, our data support the extension of the thrifty phenotype hypothesis to limb growth, and suggest that certain elements of limb growth may be sacrificed under tough conditions to buffer more functional traits. The environments occupied by contemporary human populations are characterised by a wide variety of ecological stresses, including thermal load, altitude, dietary niche and disease load. Developmental plasticity is suggested to be a key mechanism by which organisms adjust to such environmental variability and has been proposed to be a notable characteristic of humans, enabling our species to colonise diverse environments with limited technological assistance There is also evidence that total lower limb length is more plastic than head-trunk height (commonly measured as sitting height) among humans th–20th century skeletal samples While only relative lower limb length is typically considered, limb segments  may also be differentially sensitive to stress-related growth disruption. Previous studies of human populations suggest that zeugopod elements may be more sensitive than their respective stylopod elements, and the tibia may be more sensitive than the ulna/radius. Within the limb, it has been demonstrated that zeugopod elements are more variable than stylopod elements, and the tibia more than the radius The reasons for the variable environmental sensitivity of different anatomical regions are also unclear. Three hypotheses may be relevant to explaining this heterogeneity in growth plasticity, and so may help to further our understanding of the underlying mechanisms and the basis of associations between body proportions and disease risk.First, the thrifty phenotype hypothesis Second, the distal blood flow hypothesis was proposed in order to explain the greater reduction in tibia length than head, trunk or upper limb dimensions in foetuses exposed to prenatal hypoxia through maternal smoking during pregnancy. It assumes that the tibia is more affected by foetal hypoxia than other limb long bones, head-trunk height, upper limb length or head size, because the tibia is the last among these regions to receive oxygenated blood due to the nature of the foetal circulation A third possibility that must be considered is adaptation to cold, since the impact of temperature adaptation on body size and proportions has long been recognised in the form of Bergmann’s and Allen’s ‘rules’ The first aim of this study was to investigate heterogeneity in the sensitivity of different regions of the body to childhood conditions through the comparison of two populations with contrasting burdens of ecological and environmental stress. We analysed total upper and lower limb lengths, zeugopod and autopod lengths; head-trunk height; and head circumference in highland (n = 200) and lowland (n = 247) Peruvian children aged 6 months to 14 years, using cross-sectional anthropometric data . In PeruGiven that the phenomenon of brain-sparing growth has been widely demonstrated and accepted, we explored site differences in the lengths of the limbs, limb segments and head-trunk height after adjusting out the variance due to variation in head circumference. This approach highlights variation in the size of distinct regions of the body over and above that in head size, which is most extensively but incompletely Anthropometric variables were converted to z scores prior to analysis using the LMS method . Z scores are widely used in paediatric research in order to adjust data for age effects so that characteristics can be compared across a range of ages. They represent the position of an individual within the frequency distribution for a given age in terms of standard deviations from the mean. The use of z scores therefore takes into account variation in body proportions at different ages, as well as differences in the variability of different anthropometric dimensions. All ANCOVA were performed on these z scores.The second aim of this study was to consider which model  the results do not support. If the thrifty phenotype hypothesis offered the most appropriate explanation, it was predicted that the smallest population differences would be observed in head circumference in line with the brain-sparing model, and that when variance due to variation in head circumference had been adjusted out, head-trunk height and autopod lengths would show smaller population differences than total limb or zeugopod lengths, since the growth of the former is hypothesised to be relatively more protected from stress exposure to maintain function. In contrast, if the distal blood flow model best accounted for the patterns observed, a gradient of increasing population difference in limb or limb segment length was predicted, and it was expected that the upper limb would show smaller size differences between samples than the lower limb. Similarly, temperature adaptation would predict an increase in population differences from proximal to distal along each limb, though perhaps without any difference between upper and lower limb. Under all models, adjusting out the variance due to head circumference z score, head-trunk height would be predicted to show the smallest differences between samples, though the three theories would invoke different physiological mechanisms.The ANCOVA results confirm that even when adjusting out variance due to head circumference z score and age, significant differences remain between groups in head-trunk height and limb length z scores . Site diIn each analysis, age and sex terms were not significant, suggesting that the observed patterns do not vary significantly by age. This is partly expected as z scores adjust for age and sex, but if the differences in the relationship between head circumference and z scores had varied with age, this should have been detectable in the analysis. The results therefore indicate that the patterns observed here apply across the range of ages studied (0.5–14 years).There is clear variation in the magnitude of differences between highland and lowland Peruvian children in the size of distinct regions of the body. Adjusting out the variance due to head circumference z score and age, differences in head-trunk height were markedly smaller than differences in limb or limb segment lengths. In both limbs, site contrasts were smaller in the autopod (hand or foot) than in total limb or zeugopod (ulna and tibia) lengths, and differences in zeugopod length were slightly greater than in total limb length. Observed differences were similar in both the upper and lower limbs and in their homologous segments. These site differences did not show any significant influence of age or sex.The results do not support the distal blood flow or temperature adaptation models. The similarity in site differences in total limb or limb segment lengths between the upper and lower limb, and the smaller differences in autopod lengths compared with total limb or zeugopod lengths refute the distal blood flow hypothesis, which predicts greater differences in total lower than total upper limb length, and greater differences in autopod than zeugopod length. Differences in ambient temperature are also unlikely to account for the pattern of results. Similar to the distal blood flow hypothesis, a response to cold exposure was predicted to result in a proximo-distal gradient of increasing length reduction from stylopod to autopod, but this was not observed in our data.Like many previous studies, the results support the phenomenon of brain-sparing growth under conditions of stress. Furthermore, the data suggest the selective protection of certain anatomical regions (primarily head-trunk height and autopod lengths) over others (e.g. zeugopod length), supporting the extension of the thrifty phenotype hypothesis to limb proportions, particularly with reference to autopod size. This hypothesis would suggest that head-trunk height, and to a lesser extent autopod (hand or foot) length, may be protected compared with zeugopod or total limb lengths for functional reasons, although this interpretation remains hypothetical until we are able to understand better the mechanisms underlying the patterns observed here.We suggest that site differences in body proportions reflect differential overall exposure to environmental stress. The highland population is more deprived in terms of socioeconomic position and access to education and healthcare, and suffers greater exposure to poor nutrition, hypoxia and cold than the lowland population. Elucidating the relative influences of these various stressors was not possible in the current dataset due to the high inter-correlation between potential explanatory factors. This would require comparison of sites with greater overlap in their socioeconomic, nutritional and health characteristics. Furthermore, environmental stressors like hypoxia and nutrition may have different effects on growth and interact to affect final body size and proportions It is also considered unlikely that genetic differences between populations explain the results, although this remains to be explicitly tested. Most Peruvians demonstrate predominantly native South American ancestry with a degree of European admixture A small degree of genetic difference may exist between the study populations, and given known differences in body proportion between some major world populations One study that attempted to determine genetic and altitude effects on relative head-trunk height and lower limb length among Bolivian children was unable to make clear inferences regarding the impact of genetic factors for this reason In general, the limited data available and migration history suggests that highland populations tend to show a lower level of European and other admixture, although many residents of shanty towns such as Pampas de San Juan de Miraflores are migrants or the recent descendants of migrants from the Andean highlands The detailed physiological basis of the relationship between relatively shorter lower limbs and elevated risk of adult chronic disease is still emerging, but it has been suggested that the early growth environment may influence both body proportions and metabolic characteristics which subsequently impact on chronic disease risk. For example, a number of studies suggest that relatively shorter lower limbs act an index of metabolic capacity, and mothers who are shorter, and especially those with relatively shorter lower limbs, show a reduced tolerance of obesity and a greater propensity to develop gestational diabetes It should be noted that not all studies report an association between relative total lower limb length and childhood exposure to stress or adult disease risk The present study was unable to address whether differences in body proportions exist from birth, although the results indicated differences from 6 months of age onwards. Data on body proportions in Andean neonates The pattern of growth restriction described here could reflect the growth rate of different tissues at the time of stress exposure  as a particularly sensitive environmental marker In summary, our data suggest heterogeneity in the sensitivity of different anatomical regions to stress exposure during growth. Adjusting out the variance due to head circumference, lengths of the zeugopod (ulna and tibia) show greatest differences between sites and so may be most sensitive to stress, while autopod (hand and foot) lengths show smaller differences and so may be relatively protected. Similarly head-trunk height and especially head circumference also appear to be relatively protected from the impacts of stress exposure on growth compared with the limbs. The results do not support the distal blood flow model or temperature adaptation, and therefore support the thrifty phenotype hypothesis, suggesting that this hypothesis could be extended to explain trade-offs in relative limb growth. We suggest ulna length may, like tibia length, offer an additional marker of early-life stress exposure in this population. Further work is required to establish the extent to which different environmental factors affect body proportions and whether our findings extend to other populations.Participation was voluntary and the study was conducted according to accepted international ethical standards for research involving human subjects (Declaration of Helsinki) The lowland study population was from the peri-urban community of Pampas de San Juan de Miraflores in Lima , a well-established but unplanned settlement of generally low socioeconomic status Stature and head-trunk height (sitting height) were measured to the nearest mm following standard protocols with participants dressed in light clothes without shoes Anthropometric variables were converted to z scores for the combined highland and lowland dataset according by the LMS method Differences between the two sites in the size of different anthropometric measurements were tested using ANCOVA of the z scores as described in the Introduction. ANCOVA was selected rather than MANCOVA since the dependent variables violate assumptions regarding multicollinearity required for MANCOVA Table S1Summary statistics for anthropometric variables age group for lowland  and highland  children. Data presented as ‘mean (standard deviation)’, n presented as ‘lowland, highland’.(DOC)Click here for additional data file.Table S2Differences between populations (lowland-highland) in mean raw measurements by age group. Standard error of the difference given in brackets.(DOC)Click here for additional data file.Table S3Percentage differences between populations (lowland-highland) in mean raw measurements by age group.(DOC)Click here for additional data file.Table S4Differences between populations (lowland-highland) in mean z scores by age group. Standard error of the difference given in brackets.(DOC)Click here for additional data file.


Enveloped virus release is driven by poorly understood proteins that are functional analogs of the coat protein assemblies that mediate intracellular vesicle trafficking. We used differential electron density mapping to detect membrane integration by membrane-bending proteins from five virus families. This demonstrates that virus matrix proteins replace an unexpectedly large portion of the lipid content of the inner membrane face, a generalized feature likely to play a role in reshaping cellular membranes. Life as we know it comes wrapped in membranes. These semipermeable barriers are necessary to maintain the electrical and chemical gradients essential to life. In eukaryotes, intracellular vesicle transport is mediated by vesicle transport proteins that are needed to move cargo between organelles and across the plasma membrane Enveloped viruses encode matrix proteins that mold the membrane around new virus particles as they exit a host cell, a process analogous to vesicle transport. Matrix proteins occupy a middle position inside the virus between the membrane and the virus core, are essential for virus assembly, and some direct the release of virus-like particles without help from other viral proteins In order to see how working matrix proteins interact with the membrane, we used cryo-electron microscopy to take pictures of virus populations in a near-native environment. In addition to viruses, these populations naturally contained a few empty vesicles and a heterogeneous collection of incompletely assembled viruses that were released from the same cells as the virus. Of these, the most interesting were called GP vesicles, which had virus surface glycoproteins but lacked a visible matrix , acylated matrix proteins  and non-acylated proteins (Orthomyxoviridae M1). The three-dimensional structures of these proteins, where known, appear to be unrelated Matrix proteins from different viruses are believed to use different methods to interact with the membrane. Our dataset included representatives of the three common membrane anchor types, including viruses with transmembrane matrix proteins  and particle type , including cross-effects. The sample region, particle and micrograph were included as nested random effects. Model fit was deemed acceptable by inspection of Q-Q plots. Significant differences in the mean signal value were subsequently evaluated using Tukey contrasts, to allow for multiple comparisons.


Outbreaks of hepatitis C virus (HCV) infection have been reported in HIV-positive men who have sex with men (MSM) in North America, Europe and Asia. Transmission is believed to be the result of exposure to blood during sexual contact. In those infected with HIV, acute HCV infection is more likely to become chronic, treatment for both HIV and HCV is more complicated and HCV disease progression may be accelerated. There is a need for systematic reviews and meta-analyses to synthesize the epidemiology, prevention and methods to control HCV infection in this population.Eligible studies will include quantitative empirical data related to sexual transmission of HCV in HIV-positive MSM, including data describing incidence or prevalence, and associations between risk factors or interventions and the occurrence or progression of HCV disease. Care will be taken to ensure that HCV transmission related to injection drug use is excluded from the incidence estimates. Scientific databases will be searched using a comprehensive search strategy. Proceedings of scientific conferences, reference lists and personal files will also be searched. Quality ratings will be assigned to each eligible report using the Newcastle–Ottawa scale. Pooled estimates of incidence rates and measures of association will be calculated using random effects models. Heterogeneity will be assessed at each stage of data synthesis.HIV-positive MSM are a key HCV-affected population in the US and other high-income countries. This review seeks to identify modifiable risk factors and settings that will be the target of interventions, and will consider how to constitute a portfolio of interventions to deliver the greatest health benefit. This question must be considered in relation to the magnitude of HCV infection and its consequences in other key affected populations, namely, young prescription opioid users who have transitioned to illicit opiate injection, and older injection drug users among whom HCV prevalence and incidence are extremely high. This review is part of a series of systematic reviews and meta-analyses that will synthesize the evidence across all these population groups and develop recommendations and decision tools to guide public health resource allocation.CRD42013006462PROSPERO registration number:  There are an estimated 8.4 million men who have sex with men (MSM) in the US ; 16% areIn HIV-infected patients, acute HCV infection is more likely to become persistent, and HCV treatment is less likely to result in cure . The risCurrent recommendations to prevent HCV in HIV-positive MSM center on detecting acute infection through screening for elevated liver enzymes every three months and providing immediate HCV treatment to HCV RNA positive patients to prevent chronic HCV infection ,15. EarlIn this systematic review, we will synthesize existing data describing rates of sexual HCV transmission in HIV-positive MSM and factors associated with transmission, rates of reinfection post-HCV treatment and the effects of interventions to prevent or treat HCV infection. Figure HCV infection related to drug use has been addressed in several previous systematic reviews. These have covered HCV epidemiology in people who smoke or inhale drugs such as heroin, cocaine or crack , HCV epiThis study will consist of a systematic review and meta-analysis of the epidemiology, natural history and methods to control sexually transmitted HCV infection in HIV-positive MSM, as shown in Figure We will include published and unpublished quantitative epidemiologic and intervention studies using cross-sectional, cohort (prospective and retrospective) and case–control designs. Epidemiologic studies will report HCV prevalence, incidence or risk factor analyses. Intervention studies will report on the effects of interventions to prevent or treat HCV infection in this population. Studies must include male individuals who are HIV-positive and who reported having sex with other men. We will not include data related to HIV-negative MSM or heterosexual men. An explicit mention that HIV-positive MSM using injection drugs were excluded from the analysis will be required because such individuals likely acquired HCV infection through the use of contaminated injection equipment rather than from sexual exposure. In studies that included both injecting and non-injecting MSM, separate estimates must be provided for non-injectors.Studies among incarcerated persons will also be excluded, as infection rates and circumstances surrounding transmission are not likely to be generalizable to the broader population of HIV-positive MSM. Epidemiologic studies that enrolled HIV-positive MSM from settings where infection, exposure or disease progression rates were likely to be biased, such as in hepatology or gastroenterology clinics, or in sexually transmitted infection clinics, will be included but this will be noted in the quality ratings. All ages and individuals from any racial or ethnic group will be included. The search will include English-language reports available from 1 January 1990 through 31 December 2013.All reports must state that laboratory tests were used to ascertain HCV infection among subjects. Data reports that used self-reports or questionnaires to identify HCV status will be excluded. Rates of acute HCV infection or seroconversion, and reinfection with HCV post-HCV treatment in HIV-positive MSM will be included. We define subjects with ‘HCV seroconversion’ or ‘acute HCV’ as those who have been screened and tested positive for HCV antibodies (serology) or RNA within 12 months of previously testing negative. We adopted the European AIDS Treatment Network (European NEAT) Acute Hepatitis C Infection Consensus Panel criteria .preferred criteria are seroconversion or positive HCV RNA and a documented negative HCV RNA or negative HCV antibody in the previous 12 months. Alternative criteria include positive HCV RNA and an elevated ALT with or without other clinical signs of hepatitis.The Studies using the preferred criteria will be given higher quality ratings than those that use the alternative criteria. HCV reinfection will be defined as newly detectable HCV RNA following clearance of the infection in response to treatment of HCV infection.Exposures of interest include sexual practices that are hypothesized to increase the risk of blood exposure and thereby facilitate HCV transmission. These include unprotected receptive and insertive anal sex, practices that can damage the genital and anal mucosal surfaces such as fisting or ‘rough sex’, participation in group sex events and prolonged periods of sexual activity . Age, raThe search strategy was developed in consultation with a medical librarian. The PubMed, EMBASE and BIOSIS databases will be searched using terms that cover the themes hepatitis C virus, men who have sex with men, transmission, prevention and treatment. Additional reports will be located by searching conference proceedings , investigators’ personal files, and reference lists of reviews and related articles.Reports obtained via the search strategy (abstracts and full-text articles) will be imported into Endnote X6  and duplCrude and adjusted measures of association  between disease outcomes (HCV infection and reinfection) and relevant exposures, confounding and moderating factors will be recorded. For those reports that are missing key data of interest to this systematic review but were thought potentially to have collected these data, the corresponding authors will be contacted.Screening and data abstraction will be carried out by staff with graduate training in research methodology and additional training in HCV epidemiology, and systematic review and meta-analysis methods. A pilot study will be carried out to test and refine procedures for screening and data abstraction. Two staff will independently screen and code a subset of articles retrieved using the search criteria and will compare results. Discrepancies between the results will be discussed and the protocol will be revised to clarify procedures. This process will be repeated until consensus is reached. Reports that were deemed ineligible will be reviewed by the project director (AEJ) to ensure that no eligible reports are excluded. In addition, all coding will be reviewed for accuracy and completeness by the project director and the principal investigator (HH). Weekly staff meetings will discuss and resolve any issues that may arise. A written study manual will be developed to guide the process and to record special cases and their resolution.In this synthesis, bias in the included studies may arise in the form of selection bias, misclassification of exposure or outcome, and confounding due to non-comparability of the groups being compared. The quality rating procedure that will be employed is based on the Newcastle–Ottawa Scale, which assigns quality ratings to studies in relation to these threats to internal validity  . Some tyThe potential for selection bias in case–control studies will be evaluated in relation to whether similar and adequate methods were used to classify case vs control status, and whether cases and controls arose from the same underlying population . In cohort studies, selection bias will be judged in relation to whether ascertaining exposure or selection of the exposed cohort was related to likelihood of HCV infection, and whether methods were adequate in assuring that HCV infection was not present at the start of the cohort study (see European NEAT’s preferred criteria discussed above).Comparability of cases and controls refers to whether matching or adjustment for confounding (differences in the distribution of factors across cases and controls that could bias estimates of association) was carried out. In cohort studies, comparability refers to whether the assessment of the association between exposure and HCV infection adjusted for important differences between the exposed and unexposed cohorts.In case–control studies, classification of cases and controls with respect to exposure must be unbiased, and using the same method to ascertain exposure for cases and controls is preferred. Ascertainment of exposure  also relates to the extent to which reliable methods were used to determine that HIV-positive MSM were not also injection drug users. In cohort studies, misclassification of the outcome  will be addressed as part of the eligibility screening. Studies using the European NEAT alternative criteria (described above ) will beSynthesis will begin with the search for homogeneous subsets within sets of studies, followed by meta-analysis and calculation of summary estimates within the homogeneous subsets. Evidence of heterogeneity will be evaluated at each step in the analysis to distinguish between a true variation of effects and heterogeneity due to other differences. Effect measures reported as hazards ratios, risk ratios or relative risks will be transformed into odds ratios using standard methods . Forest I2 statistic [I2, the τ-statistic (variability due to inter-study variance), as well as methodological, study quality and other differences into consideration in determining whether to pool estimates. Effect size estimates will be combined using standard meta-analytic techniques in the form of pooled odds ratios and their 95% confidence intervals [Some statistical heterogeneity in a meta-analysis is inevitable due to the methodological diversity of the studies. We will use Cochran’s Q statistic  to detertatistic . We willntervals . We willntervals . Potentintervals ,43.This systematic review and meta-analysis will critically assess the evidence related to sexual HCV transmission in a key affected population – HIV-positive MSM. It is anticipated that this review will identify modifiable behavioral risk factors and settings, which will be the target of interventions to control transmission. These, along with estimates of the range and magnitude of HCV transmission in this population, will be key inputs to simulations that will address the question of how to constitute a portfolio of interventions so as to deliver the greatest health benefit given a particular budget.During the past decade, clusters of HCV infection in 15 to 24 year olds who have transitioned from abuse of prescription opioids to illicit opiate injection have been reported throughout the US ,45. As tALT: alanine aminotransferase; CI: confidence interval; HCV: hepatitis C virus; MSM: men who have sex with men; PWID: people who inject drugs; PY: person years.The authors declare that they have no competing interests.HH conceived and designed the study and wrote the manuscript. JN collected data and tested the protocol. AEJ, DCDJ, JW, KD, BK, RSB and JK conceived and designed the study and undertook a critical revision of the manuscript. All authors have read and approved the final version of the manuscript.


Even today the investigation of U-shaped functions in human development is of considerable importance for different domains of Developmental Psychology. More and more scientific researchers focus their efforts on the challenge to describe and explain the phenomenon by identifying those skills and abilities being affected. The impact of U-shaped functions on diagnostic decision-making and on therapeutic treatment programs highlights the importance of understanding the nature of non-monotonic development. The present article therefore addresses the relevant questions of how U-shaped functions are defined in theory, in which developmental domains such non-monotonic growth curves are suggested to occur, and which implications there are for future methodology and diagnostic practice. Finally, it is recommended to clearly identify those interactions between proximal and distal subcomponents which are expected to contribute to a U-shaped development. The explanation of intraindividual changes in behavior, as well as the identification of interindividual variations in such changes across the life span are regarded as the overall task of developmental science based on a sufficiently large sample size that(b)provides a sufficiently high concentration of values among the entire age range.Test construction in Developmental Psychology mostly follows the rules and axioms of Classical Test Theory , might be insufficient and nonsensical depending on the diagnostic context.Qualitatively related and confounded variables which contribute to specific stages of development may easily lead to flawed diagnostic decisions whenever they are quantified by test results. Interpreting such test results by merely evaluating how many deviations the achieved scores are above or below the mean (e.g., expressed in standard scores like Whenever U-shaped functions are expected to characterize the development of diagnostically relevant proficiencies, it is advisable to split the overall test performance into subcomponents and to assess them separately. For example, the accuracy of aiming in direction might include monotonically improving perceptual, cognitive, and motor components. These subcomponents should be assessed separately from each other to be at least able to capture specific developmental core elements. The general sensitivity and specificity of a diagnostic instrument could also be increased for the benefit of an accurate identification of clinically conspicuous symptoms.Despite the fact that many empirical findings support the occurrence of U-shaped functions in different developmental domains, there remains a critical stance toward these results as well. It still has to be clarified whether empirically obtained patterns do really reflect true courses of developmental change, or whether a U-shaped function represents nothing but a methodological artifact. Developmental functions which may vary depending on whether children were tested once a year, once a month, or every day Siegler, , highligAlthough numerous U-shaped functions were identified within different fields of Developmental Psychology down to the present day, however, research findings still appear to be fragmentary to some extent. Therefore, future research based on fruitful scientific cooperation is indispensible when it comes to lay the groundwork for gaining new insights into the nature of U-shaped development.Current methodological innovations have an immediate effect of increasing the priority given to the goal of more accurate descriptions, simply by making them possible. Morse et al.  presenteThe phenomenon of a U-shaped development plays a decisive role for diagnostics within therapeutic treatment programs. If U-shaped functions can be considered to result from an integration of new processing strategies, then similar developmental patterns ought to be generated by reorganizational processes within a therapy as well. Just consider that a child is often faced with the instruction to quit its old and inadequate behavioral strategies in favor of novel target-oriented ones during a common therapeutic process. Although being psychotherapeutically supported, the same child could initially suffer losses in performance due to cognitive overload. A temporary regression here could result from the treatment itself before the child’s capability improves up to an age-appropriate level again. Such an initiated U-shaped development that would actually support therapeutic effectiveness in the given context, however, might be misinterpreted by therapists that do falsely assume a monotonic improvement. In the most unfavorable case, a highly effective psychotherapeutic treatment could then be discontinued according to a seeming lack of success. It is therefore necessary for future clinical psychologists to take these considerations about U-shaped functions into account when developing new therapeutic treatment programs, evaluating the efficiency of those being currently conducted, or analyzing individual development profiles.In future, diagnostic procedures should be optimized to identify those interacting subcomponents which are said to contribute to the development of the ability in question. A more systematic analysis of the interactions between those subcomponents would then provide the opportunity to extract helpful information about clinically significant indicators for developmental change.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.