Neurotrophic factors and the regeneration of adult retinal ganglion cell axons

The adult central nervous system (CNS) has only a limited capacity to regenerate axons after injury. This is due to a number of factors including the presence of extrinsic inhibitory factors that limit plasticity, lack of effective trophic support, and intrinsic changes in neuronal responsiveness. In this review, we describe the expression and role of neurotrophins in retinal ganglion cells (RGCs) during development and adulthood, and the receptors and miscellaneous signaling systems that influence axonal regeneration after injury. The impact of exogenous neurotrophic factors on adult RGCs injured at different sites in the visual pathway is described for several modes of delivery, including recombinant factors, viral vectors, cell transplantation, as well as combinatorial treatments involving other pharmacotherapeutic agents. Indirect, off-target effects of neurotrophic factors on RGC axonal regeneration are also considered. There remain unresolved issues relating to optimal delivery of neurotrophic factors, and we emphasize the need to develop safe, reliable methods for the regulation of exogenous supply of these factors to the injured CNS.

Effects of the insemination of hydrogen peroxide-treated epididymal mouse spermatozoa on γH2AX repair and embryo development

BACKGROUND

Cryopreservation of human semen for assisted reproduction is complicated by cryodamage to spermatozoa caused by excessive reactive oxygen species (ROS) generation.

METHODS AND FINDINGS

We used exogenous ROS (H(2)O(2)) to simulate cryopreservation and examined DNA damage repair in embryos fertilized with sperm with H(2)O(2)-induced DNA damage. Sperm samples were collected from epididymis of adult male KM mice and treated with capacitation medium (containing 0, 0.1, 0.5 and 1 mM H(2)O(2)) or cryopreservation. The model of DNA-damaged sperm was based on sperm motility, viability and the expression of γH2AX, the DNA damage-repair marker. We examined fertility rate, development, cell cleavage, and γH2AX level in embryos fertilized with DNA-damaged sperm. Cryopreservation and 1-mM H(2)O(2) treatment produced similar DNA damage. Most of the one- and two-cell embryos fertilized with DNA-damaged sperm showed a delay in cleavage before the blastocyst stage. Immunocytochemistry revealed γH2AX in the one- and four-cell embryos.

CONCLUSIONS

γH2AX may be involved in repair of preimplantation embryos fertilized with oxygen-stressed spermatozoa.

Perceptions of health and environmental impacts of e-waste management in Ghana

This paper explores the perception of health and environmental concerns of workers and residents living close to e-waste recycling sites in Ghana using both qualitative and quantitative research techniques. The social constructionist approach and a logit regression model were adopted to examine the rationale of their claims and concerns which have hitherto been unknown and unexplored. We find that workers' environmental and health perceptions were seriously downplayed and do not match those of epidemiological studies, revealing a lack of convergence between lay and expert knowledge. This study further shows a respondent-specificity rationale; the perception of those directly involved in the processes was mainly influenced by economic considerations, while some at best displayed "genuine" ignorance. We recommend that all policy interventions incorporate approaches that have a better chance of arriving at conclusions economically meaningful to participants and that facilitate greater understanding of health and environmental issues.

Reproducibility of retinal nerve fiber layer measurements with manual and automated centration in healthy subjects using spectralis spectral-domain optical coherence tomography

Objective. The aim of this study was to test the reproducibility of the Heidelberg Spectralis SD-OCT and to determine if provided software retest function for follow-up exam is superior to manual centration. Design. Prospective, cross-sectional study. Participants. 20 healthy subjects. Methods. All subjects underwent SD-OCT testing to determine retinal nerve fiber layer (RNFL) measurements sequentially on two different days and with two different centration techniques. Within-subject standard deviation, coefficient of variation, and intraclass correlation coefficient were used to assess reproducibility. Results. RNFL measurements showed high reproducibility, low within-subject standard deviation (1.3), low coefficient of variation (0.63%), and low intra-class correlation coefficient (0.98 (95% CI 0.97–0.99)) in the automated centration and manual centration groups for average RNFL Thickness. Quadrants showed slightly higher variability in the manual group compared to the automated group (within-subject standard deviation 2.5–5.3 versus 1.1–2.4, resp.). Conclusions. SD-OCT provides high-resolution RNFL measurements with high reproducibility and low variability. The re-test function allows for easier recentration for longitudinal examinations with similar results in average RNFL, but less variability in quadrant RNFL. SD-OCT high reproducibility and low variability is a promising fact and should be further evaluated in longitudinal studies of RNFL.

Update on the urotensinergic system: new trends in receptor localization, activation, and drug design

The urotensinergic system plays central roles in the physiological regulation of major mammalian organ systems, including the cardiovascular system. As a matter of fact, this system has been linked to numerous pathophysiological states including atherosclerosis, heart failure, hypertension, diabetes as well as psychological, and neurological disorders. The delineation of the (patho)physiological roles of the urotensinergic system has been hampered by the absence of potent and selective antagonists for the urotensin II-receptor (UT). Thus, a more precise definition of the molecular functioning of the urotensinergic system, in normal conditions as well as in a pathological state is still critically needed. The recent discovery of nuclear UT within cardiomyocytes has highlighted the cellular complexity of this system and suggested that UT-associated biological responses are not only initiated at the cell surface but may result from the integration of extracellular and intracellular signaling pathways. Thus, such nuclear-localized receptors, regulating distinct signaling pathways, may represent new therapeutic targets. With the recent observation that urotensin II (UII) and urotensin II-related peptide (URP) exert different biological effects and the postulate that they could also have distinct pathophysiological roles in hypertension, it appears crucial to reassess the recognition process involving UII and URP with UT, and to push forward the development of new analogs of the UT system aimed at discriminating UII- and URP-mediated biological activities. The recent development of such compounds, i.e. urocontrin A and rUII(1-7), is certainly useful to decipher the specific roles of UII and URP in vitro and in vivo. Altogether, these studies, which provide important information regarding the pharmacology of the urotensinergic system and the conformational requirements for binding and activation, will ultimately lead to the development of potent and selective drugs.

Influenza virus pathophysiology and brain invasion in mice with functional and dysfunctional Mx1 genes

Mice with a dysfunctional myxovirus resistance-1 (dMx1) gene transport intranasally-instilled PR8 influenza virus to the olfactory bulb (OB) within 4 h post-infection. To determine if the presence of a functional Mx1 (fMx1) gene would influence this brain viral localization and/or disease, we infected mature C57BL/6 dMx1 and fMx1 mice under the same conditions and observed sickness behaviors, viral nucleoprotein (NP) RNA expression and innate immune mediator (IIM) mRNA expression in selected tissues at 15 and 96 h post-infection. Virus invaded the OB and lungs comparably in both sub-strains at 15 and 96 h as determined by nested PCR. In contrast, virus was present in blood and somatosensory cortex of dMx1, but not fMx1 mice at 96 h. At 15 h, sickness behaviors were comparable in both sub-strains. By 96 h dMx1, but not fMx1, were moribund. In both 15 and 96 h lungs, viral NP was significantly elevated in the dMx1 mice compared to the fMx1 mice, as determined by quantitative PCR. OB expression of most IIM mRNAs was similar at both time periods in both sub-strains. In contrast, lung IIM mRNAs were elevated in fMx1 at 15 h, but by 96 h were consistently reduced compared to dMx1 mice. In conclusion, functional Mx1 did not alter OB invasion by virus but attenuated illness compared to dMx1 mice. Inflammation was similar in OBs and lungs of both strains at 15 h but by 96 h it was suppressed in lungs, but not in OBs, of fMx1 mice.

Coupled parametric model for estimation of visual field tests based on OCT macular thickness maps, and vice versa, in glaucoma care

The current standard of care for glaucoma patients consists of functional assessment of vision via visual field (VF) testing, which is sensitive but subjective, time-consuming, and often unreliable. A new imaging technology, Fourier domain optical coherence tomography (OCT), is being introduced to assess the structural characteristics of the macula. This new complementary exam is efficient, objective, and reliable. A complex, but consistent, relationship exists between the structural information provided by macular OCT and the functional information gathered by VF maps. We propose a learning-based framework with the ability to estimate the VF map based on OCT macular thickness measurements as input (and vice versa). Central to this algorithmic framework is a coupled parametric model that captures not only the individual variabilities of the OCT macular thickness measurements and the VF maps, but also their co-dependencies. This model is derived by applying principal component analysis (PCA) to a library consisting of various pairs of OCT and VF maps. The parameters of this coupled model are obtained by solving a linear least squares problem. Next, these estimated parameters are used, in conjunction with the eigenvectors derived from PCA, to compute the estimate. The accuracy of this coupled parametric estimation model was evaluated by performing multiple leave-one-out cross validation experiments.

Effects of urotensin II on functional activity of late endothelial progenitor cells

Urotensin II (UII) is a potent vasoactive cyclic peptide which has multiple effects on the cardiovascular system. However, the effects of UII on late endothelial progenitor cells (EPCs) are still unclear. The aim of the present study is to investigate whether UII influences the functional activity of late EPCs. Late EPCs were isolated from human umbilical cord blood by Ficoll density gradient centrifugation and treated with UII (10(-10), 10(-9), 10(-8), 10(-7) and 10(-6)M), or vehicle control. Expression of urotensin II receptor (UT) in late EPCs was confirmed by indirect immunofluorescence staining. Late EPCs proliferation, migration and in vitro vasculogenesis activity were assayed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, transwell chamber assay, and matrigel tube formation assay. Late EPCs adhesive assay was performed by replating cells on fibronectin-coated dishes, and then adherent cells were counted. Incubation with UII increased the migratory, adhesive and in vitro vasculogenesis capacity and inhibited the proliferative activity of late EPCs. Furthermore, these UII-mediated effects on late EPCs were attenuated by pretreatment with the UT antagonist urantide. These findings indicate that UII may exert multiple effects on functional activity of late EPCs through UT.

Nitrate Determination of Vegetables in Varzeghan City, North-western Iran

Background Vegetables play an important role in human nutrition. Nitrate content is a signifi-cant quality criterion to determine characteristic of vegetables. About 80% of nitrate intake in human is from vegetables and fruits. High dietary intake of nitrate is seen as an undesirable be-cause of its association with gastric cancer and infantile methemoglobinemia. Varzeghan, North¬western Iran is one of the cities with high Age-standardized incidence rates (ASR) of gastric can¬cer in Iran. Currently, in Varzeghan there is no available and accurate information describing ni¬trate concentration as one of the important risk factors of vegetables for human consumption. Methods In this cross sectional study totally 11 types of vegetables (cabbage, lettuce, spinach, parsley, coriander, dill, leek, fenugreek, tarragon, fumitory and mint) from several different green¬grocery of Varzeghan were collected in spring (April) and autumn (November and December) 2011 and their nitrate contents were analyzed. Results Mean nitrate contents at the above noted fresh vegetables were 161, 781, 83, 707, 441, 501, 1702, 684, 805, 772 and 191 mg NO3-kg-1 respectively. In none of the 11 fresh vegetables nitrate content were not more than established limitations. Conclusion Nitrate concentrations were below of others reported at different countries. The mean concentration of nitrate at all vegetables in autumn was higher than in spring significantly.

The 2009 pandemic influenza virus: where did it come from, where is it now, and where is it going?

Around 2008 or 2009, an influenza A virus that had been circulating undetected in swine entered human population. Unlike most swine influenza infections of humans, this virus established sustained human-to-human transmission, leading to a global pandemic. The virus responsible, 2009 pandemic H1N1 (H1N1pdm), is the result of multiple reassortment events that brought together genomic segments from classical H1N1 swine influenza virus, human seasonal H3N2 influenza virus, North American avian influenza virus, and Eurasian avian-origin swine influenza viruses. Genetically, H1N1pdm possesses a number of unusual features, although the genomic characteristics that permitted sustained human-to-human transmission are yet unclear. Human infection with H1N1pdm has generally resulted in low mortality, although certain subgroups (including pregnant women, people with some chronic medical conditions, morbidly obese individuals, and immunosuppressed people) have significantly higher risk of severe disease. As H1N1pdm has spread throughout the human population it continued to evolve. It has also reentered the swine population as a circulating pathogen, and has been transiently identified in other species such as turkeys, cats, and domestic ferrets. Most genetic changes in H1N1pdm to date have not been clearly linked to changes in antigenicity, disease severity, antiviral drug resistance, or transmission efficiency. However, the rapid evolution rate characteristic of influenza viruses suggests that changes in antigenicity are inevitable in future years. Experience with this first pandemic of twenty-first century reemphasizes the importance of influenza surveillance in animals as well as humans, and offers lessons to develop and enhance our ability to identify potentially pandemic influenza viruses in the future.

Overview of influenza viruses

The influenza virus (IV) is still of great importance as it poses an immanent threat to humans and animals. Among the three IV-types (A, B, and C) influenza A viruses are clinically the most important being responsible for severe epidemics in humans and domestic animals. Aerosol droplets transmit the virus that causes a respiratory disease in humans that can lead to severe pneumonia and ultimately death. The high mutation rate combined with the high replication rate allows the virus to rapidly adapt to changes in the environment. Thereby, IV escape the existing immunity and become resistant to drugs targeting the virus. This causes annual epidemics and demands for new compositions of the yearly vaccines. Furthermore, due to the nature of their segmented genome, IV can recombine segments. This can eventually lead to the generation of a virus with the ability to replicate in humans and with novel antigenic properties that can be the cause of a pandemic outbreak. For its propagation the virus binds to the target cells and enters the cell to replicate its genome. Newly produced viral proteins and genomes are packaged at the cell membrane where progeny virions are released. As all viruses IV depends on cellular functions and factors for their own propagation, and therefore intensively interact with the cells. This dependency opens new possibilities for anti-viral strategies.

Effects of hepatitis B virus S protein exposure on sperm membrane integrity and functions

BACKGROUND

Hepatitis B is a public health problem worldwide. Viral infection can affect a man's fertility, but only scant information about the influence of hepatitis B virus (HBV) infection on sperm quality is available. The purpose of this study was to investigate the effect of hepatitis B virus S protein (HBs) on human sperm membrane integrity and functions.

METHODS/PRINCIPAL FINDINGS

Reactive oxygen species (ROS), lipid peroxidation (LP), total antioxidant capacity (TAC) and phosphatidylserine (PS) externalization were determined. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays and flow cytometric analyses were performed. (1) After 3 h incubation with 25 µg/ml of HBs, the average rates of ROS positive cells, annexin V-positive/propidium iodide (PI)-negative cells, Caspases-3,-8,-9 positive cells and TUNEL-positive cells were significantly increased in the test groups as compared to those in the control groups, while TAC level was decreased when compared with the control. The level of malondialdehyde (MDA) in the sperm cells exposed to 50 µg/ml of HBs for 3 h was significantly higher than that in the control (P<0.05-0.01). (2) HBs increased the MDA levels and the numbers of ROS positive cells, annexin V-positive/PI-negative cells, caspases-3, -8, -9 positive cells and TUNEL-positive cells in a dose-dependent manner. (3) HBs monoclonal antibody (MAb) and N-Acetylcysteine (NAC) reduced the number of ROS-positive sperm cells. (4) HBs decreased the TAC levels in sperm cells in a dose-dependent manner.

CONCLUSION

HBs exposure could lead to ROS generation, lipid peroxidation, TAC reduction, PS externalization, activation of caspases, and DNA fragmentation, resulting in increased apoptosis of sperm cells and loss of sperm membrane integrity and causing sperm dysfunctions.

Sperm DNA damage in patients with chronic viral C hepatitis

INTRODUCTION

The aim of this study was to evaluate the conventional and biofunctional parameters of sperm in young infertile patients with Hepatitis C (HCV) infection.

METHODS

Forty HCV patients with primary infertility, aged 27 to 42 years (mean 36.4 years) and twenty HCV patients with secondary infertility aged 28 to 45 years (mean 35.0±2.8 years), underwent hormonal and sperm analysis in addition to the determination of reactive oxygen species (ROS) concentrations in the sperm and flow-cytometric evaluation. The following biofunctional sperm parameters were evaluated by flow cytometry: DNA fragmentation, mitochondrial membrane potential, chromatin condensation, and the rate of early apoptosis.

RESULTS

Overall, patients with HCV showed significantly worse median values of conventional and biofunctional sperm parameters than control subjects, including sperm density (31.7 vs. 80.4 million/ml), forward motility (9.4 vs. 25%), normal forms (15.4 vs. 24.8%), DNA fragmentation (6.6 vs. 2.2%), low MMP (45.5 vs. 8%), an early apoptosis rate (5 vs. 2.7%), and abnormal chromatin (18.9 vs. 13.9%). Finally, HCV patients had significantly higher basal (250 vs. 75×10(3)/cpm) and stimulated (550 vs. 120×10(3)/cpm) ROS levels in semen compared to control subjects. None of the examined parameters (sperm, hormonal, biofunctional and assessment of oxidative status in the semen) was significantly different between HCV patients with primary and secondary infertilities.

DISCUSSION

These results confirm that HCV infection has a negative impact on sperm parameters. The overlap of the results observed in the two groups of HCV patients supports the hypothesis that HCV infection may cause to alterations in sperm parameters.

Human papillomavirus type 18 E6 and E7 genes integrate into human hepatoma derived cell line Hep G2

BACKGROUND AND OBJECTIVES

Human papillomaviruses have been linked causally to some human cancers such as cervical carcinoma, but there is very little research addressing the effect of HPV infection on human liver cells. We chose the human hepatoma derived cell line Hep G2 to investigate whether HPV gene integration took place in liver cells as well.

METHODS

We applied PCR to detect the possible integration of HPV genes in Hep G2 cells. We also investigated the expression of the integrated E6 and E7 genes by using RT-PCR and Western blotting. Then, we silenced E6 and E7 expression and checked the cell proliferation and apoptosis in Hep G2 cells. Furthermore, we analyzed the potential genes involved in cell cycle and apoptosis regulatory pathways. Finally, we used in situ hybridization to detect HPV 16/18 in hepatocellular carcinoma samples.

RESULTS

Hep G2 cell line contains integrated HPV 18 DNA, leading to the expression of the E6 and E7 oncogenic proteins. Knockdown of the E7 and E6 genes expression reduced cell proliferation, caused the cell cycle arrest at the S phase, and increased apoptosis. The human cell cycle and apoptosis real-time PCR arrays analysis demonstrated E6 and E7-mediated regulation of some genes such as Cyclin H, UBA1, E2F4, p53, p107, FASLG, NOL3 and CASP14. HPV16/18 was found in only 9% (9/100) of patients with hepatocellular carcinoma.

CONCLUSION

Our investigations showed that HPV 18 E6 and E7 genes can be integrated into the Hep G2, and we observed a low prevalence of HPV 16/18 in hepatocellular carcinoma samples. However, the precise risk of HPV as causative agent of hepatocellular carcinoma needs further study.

Inhibition and Termination of Physiological Responses by GTPase Activating Proteins

Physiological processes are strictly organized in space and time. However, in cell physiology research, more attention is given to the question of space rather than to time. To function as a signal, environmental changes must be restricted in time; they need not only be initiated but also terminated. In this review, we concentrate on the role of one specific protein family involved in biological signal termination. GTPase activating proteins (GAPs) accelerate the endogenously low GTP hydrolysis rate of monomeric guanine nucleotide-binding proteins (GNBPs), limiting thereby their prevalence in the active, GTP-bound form. We discuss cases where defective or excessive GAP activity of specific proteins causes significant alteration in the function of the nervous, endocrine, and hemopoietic systems, or contributes to development of infections and tumors. Biochemical and genetic data as well as observations from human pathology support the notion that GAPs represent vital elements in the spatiotemporal fine tuning of physiological processes.

Immunoglobulin G expression and its colocalization with complement proteins in papillary thyroid cancer

Except for the well-known immunoglobulin G (IgG) producing cell types, ie, mature B lymphocytes and plasma cells, various non-lymphoid cell types, including human cancer cells, neurons, and some specified epithelial cells, have been found to express IgG. In this study, we detected the expression of the heavy chain of IgG (IgGγ) and kappa light chain (Igκ) in papillary thyroid cancer cells. Using in situ hybridization, we detected the constant region of human IgG1 (IGHG1) in papillary thyroid cancer cells. With laser capture microdissection followed by RT-PCR, mRNA transcripts of IGHG1, Igκ, recombination activating gene 1 (RAG1), RAG2, and activation-induced cytidine deaminase genes were successfully amplified from isolated papillary thyroid cancer cells. We further confirmed IgG protein expression with immunohistochemistry and found that none of the IgG receptors was expressed in papillary thyroid cancer. Differences in the level of IgGγ expression between tumor size, between papillary thyroid cancer and normal thyroid tissue, as well as between papillary thyroid cancer with and without lymph node metastasis were significant. Taken together, these results indicate that IgG is produced by papillary thyroid cancer cells and that it might be positively related to the growth and metastasis of papillary thyroid cancer cells. Furthermore, it was demonstrated that IgGγ colocalized with complement proteins in the same cancer cells, which could indicate that immune complexes were formed. Such immune complexes might consist of IgG synthesized by the host against tumor surface antigens and locally produced anti-idiotypic IgG with specificity for the variable region of these 'primary' antibodies. The cancer cells might thus escape the host tumor-antigen-specific immune responses, hence promoting tumor progression.

Transcriptome network analysis reveals potential candidate genes for esophageal squamous cell carcinoma

The esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with a poor prognosis. Understanding molecular changes in ESCC should improve identification of risk factors with different molecular subtypes and provide potential targets for early detection and therapy. Our study aimed to obtain a molecular signature of ESCC through the regulation network based on differentially expressed genes (DEGs). We used the GSE23400 series to identify potential genes related to ESCC. Based on bioinformatics we constructed a regulation network. From the results, we could establish that many transcription factors and pathways closely related with ESCC were linked by our method. STAT1 also arose as a hub node in our transcriptome network, along with some transcription factors like CCNB1, TAP1, RARG and IFITM1 proven to be related with ESCC by previous studies. In conclusion, our regulation network provided information on important genes which might be useful in investigating the complex interacting mechanisms underlying the disease.

Thyroid disrupting chemicals in plastic additives and thyroid health

The globally escalating thyroid nodule incidence rates may be only partially ascribed to better diagnostics, allowing for the assessment of environmental risk factors on thyroid disease. Endocrine disruptors or thyroid-disrupting chemicals (TDC) like bisphenol A, phthalates, and polybrominated diphenyl ethers are widely used as plastic additives in consumer products. This comprehensive review studied the magnitude and uncertainty of TDC exposures and their effects on thyroid hormones for sensitive subpopulation groups like pregnant women, infants, and children. Our findings qualitatively suggest the mixed, significant (α = 0.05) TDC associations with natural thyroid hormones (positive or negative sign). Future studies should undertake systematic meta-analyses to elucidate pooled TDC effect estimates on thyroid health indicators and outcomes.

The Involvement of TRP Channels in Bone Homeostasis

Calcium and bone homeostasis are intimately related. On the one hand, bone relies on a sufficient supply of calcium to maintain its structural and mechanical properties and thus largely depends on calcium absorption in the intestine and calcium reabsorption in the kidney. On the other hand, bone serves as a calcium reserve from which calcium is mobilized to maintain normal calcium levels in blood. A negative external calcium balance will therefore at all times impair skeletal integrity. In addition to the external calcium balance, skeletal homeostasis also depends on the proper differentiation and functioning of bone cells, which relies for a large part on intracellular Ca(2+) signaling. Members of the transient receptor potential (TRP) family of ion channels affect skeletal homeostasis by mediating processes involved in the extracellular as well as intracellular Ca(2+) balance, including intestinal calcium absorption (TRPV6), renal calcium reabsorption (TRPV5), and differentiation of osteoclasts (TRPV1, TRPV2, TRPV4, TRPV5), chondrocytes (TRPV4), and possibly osteoblasts (TRPV1). In this review, we will give a brief overview of the systemic calcium homeostasis and the intracellular Ca(2+) signaling in bone cells with special focus on the TRP channels involved in these processes.

Natural and experimental infection of dogs with pandemic H1N1/2009 influenza virus

Evidence of H1N1/2009 influenza virus infection was identified in two domestic dogs in China in November 2009. Virus isolation and sequence analysis of all eight genes of the two isolates showed that they were related closely to the H1N1/2009 influenza virus circulating in humans, indicating that they were probably acquired from humans. To determine the pathogenicity and transmissibility of H1N1/2009 influenza virus in dogs, experimental infection and transmission were performed. Inoculated dogs were able to shed virus in nasal secretions, but symptoms were very mild. Uninoculated dogs were co-mingled to determine the transmissibility of the isolate, and one of three exposed dogs was shown to develop infection. The present findings indicate that human H1N1/2009 can infect dogs, but is transmitted inefficiently between dogs.

Physiology and pathophysiology of mitochondrial DNA

Mitochondria are the only organelles in animal cells which possess their own genomes. Mitochondrial DNA (mtDNA) alterations have been associated with various human conditions. Yet, their role in pathogenesis remains largely unclear. This review focuses on several major features of mtDNA: (1) mtDNA haplogroup, (2) mtDNA common deletion, (3) mtDNA mutations in the control region or D-loop, (4) mtDNA copy number alterations, (5) mtDNA mutations in translational machinery, (6) mtDNA mutations in protein coding genes (7) mtDNA heteroplasmy. We will also discuss their implications in various human diseases.

Combinatorial therapy stimulates long-distance regeneration, target reinnervation, and partial recovery of vision after optic nerve injury in mice

The optic nerve has been widely studied for insights into mechanisms that suppress or promote axon regeneration after central nervous system injury. Following optic nerve damage in adult mammals, retinal ganglion cells (RGCs) normally fail to regenerate their axons, resulting in blindness in patients who suffer from neurodegenerative diseases such as glaucoma or who have sustained traumatic injury to the optic nerve. Over the past several decades, many groups have investigated the basis of regenerative failure in the hope of developing strategies to stimulate the regrowth of axons and restore visual function. New findings show that a combination of therapies that act synergistically to activate RGCs' intrinsic growth state enables these cells to regenerate their axons the full length of the optic nerve, across the optic chiasm, and into the brain, where they establish synapses in appropriate target zones and restore limited visual responses. These treatments involve the induction of a limited inflammatory response in the eye to increase levels of oncomodulin and other growth factors; elevation of intracellular cAMP; and deletion of the pten gene in RGCs. Although these methods cannot be applied in the clinic, they point to strategies that might be.

The biology and ecology of black corals (Cnidaria: Anthozoa: Hexacorallia: Antipatharia)

Antipatharians, commonly known as black corals, are treasured by many cultures for medicinal purposes and to produce jewellery. Despite their economic and cultural importance, very little is known about the basic biology and ecology of black corals because most species inhabit deeper-water environments (>50m) which are logistically challenging to study. There has been a recent increase of studies focusing on antipatharians; however, these have not yet been comprehensively reviewed. This literature review seeks to summarize the available information on the biology and ecology of antipatharians. Although black corals occur throughout all oceans and from subtidal to abyssal depths, they are particularly common in tropical and subtropical regions at depths below 50m. Antipatharians are generally found in areas with hard substrates, low-light and strong currents. Under favourable conditions, some black coral species form dense aggregations to the point of becoming ecologically dominant. Zooplankton appears to be the major component of the diet of black corals, which feed as suspension feeders and use mucus and nematocysts to capture their prey. Previously categorized as azooxanthellate corals, recent research has revealed that many antipatharians appear capable of harbouring symbionts, but unlike other corals, dinoflagellates of the genus Symbiodinium are generally not important to the nutrition of black corals. Antipatharians reproduce through both sexual and asexual processes. In general, polyps and colonies are gonochoric, with fertilization and larval development likely occurring externally; however, to date antipatharian larvae have only been observed for a single species. Antipatharians are generally slow-growing and long-lived organisms with maximum longevities ranging from decades to millennia. Black corals are more abundant with depth, a pattern which has been hypothesized to avoid competition with obligate photosynthetic fauna. Additionally, antipatharians may compete for space by using sweeper tentacles and secondary metabolites. With the exception of a few predators such as gastropods and green sea turtles, antipatharians appear to be little impacted by predation. Like other corals, antipatharians can be habitat engineers of importance to a myriad of associated organisms including arthropods, annelids, echinoderms, mollusks, sponges and cnidarians, several of which are adapted to live exclusively on black corals. Given that most black coral species inhabit remote environments, our understanding of these organisms will depend on our ability to effectively sample and study them. Future collections, particularly in deeper waters (>50m), will be needed to determine whether antipatharian species have limited biogeographical distributions or whether this has simply been an artefact of low sampling efforts away from population centres and taxonomic uncertainties within this group. Additionally, biological and ecological studies require increased sample sizes because most information is currently derived from the examination of only a handful of specimens.

Induction of Fas mediated caspase-8 independent apoptosis in immune cells by Armigeres subalbatus saliva

BACKGROUND

It is widely recognized that the introduction of saliva of bloodsucking arthropods at the site of pathogen transmission might play a central role in vector-borne infections. However, how the interaction between salivary components and the host immune system takes place and which physiological processes this leads to has yet to be investigated. Armigeres subalbatus is one of the prominent types of mosquitoes involved in the transmission of parasitic and viral diseases in humans and animals.

METHODOLOGY/PRINCIPAL FINDINGS

Using murine peritoneal macrophages and lymphocytes, and human peripheral mononuclear cells (PBMCs), this study shows that saliva of the female Ar. subalbatus induces apoptosis via interaction with the Fas receptor within a few hours but without activating caspase-8. The process further activates downstream p38 MAPK signaling, a cascade that leads to the induction of apoptosis in capase-3 dependent manner. We further illustrate that Ar. subalbatus saliva suppresses proinflammatory cytokines without changing IL-10 levels, which might happen as a result of apoptosis.

CONCLUSIONS

Our study shows for the first time that saliva-induced apoptosis is the leading phenomenon exerted by Ar.subalbatus that impede immune cells leading to the suppression of their effecter mechanism.

Polymorphisms in the ERCC5 gene and risk of esophageal squamous cell carcinoma (ESCC) in Eastern Chinese populations

BACKGROUND

Excision repair cross complementing group 5 (ERCC5 or XPG) plays an important role in regulating DNA excision repair; its functional single nucleotide polymorphisms (SNPs) may alter DNA repair capacity and thus contribute to cancer risk.

METHODOLOGY/PRINCIPAL FINDINGS

In a hospital-based case-control study of 1115 esophageal squamous cell carcinoma (ESCC) cases and 1117 cancer-free controls, we genotyped three potentially functional SNPs of ERCC5 (SNPs, rs2296147T>C, rs2094258C>T and rs873601G>A) and estimated crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for their associations with risk of ESCC using unconditional logistic regression models. We also calculated false-positive report probabilities (FPRPs) for significant findings. We found that compared with the TT genotype, ERCC5 rs2296147 C variant genotypes were associated with a significantly lower ESCC risk (CT: adjusted OR = 0.76, 95% CI = 0.63-0.93, CT/CC: adjusted OR = 0.80, 95% CI = 0.67-0.96); however, this risk was not observed for the other two SNPs (rs2094258C>T and rs873601 G>A), nor in further stratification and haplotype analysis.

CONCLUSIONS/SIGNIFICANCES

These findings suggested that ERCC5 polymorphisms may contribute to risk of ESCC in Eastern Chinese populations, but the effect was weak and needs further validation by larger population-based case-control studies.

Real-time 4-D radiotherapy for lung cancer

Respiratory motion considerably influences dose distribution, and thus clinical outcomes in radiotherapy for lung cancer. Breath holding, breath coaching, respiratory gating with external surrogates, and mathematical predicting models all have inevitable uncertainty due to the unpredictable variations of internal tumor motion. The amplitude of the same tumor can vary with standard deviations > 5 mm occurring in 23% of T1-2N0M0 non-small cell lung cancers. Residual motion varied 1-6 mm (95th percentile) for the 40% duty cycle of respiratory gating with external surrogates. The 4-D computed tomography is vulnerable to problems relating to the external surrogates. Real-time 4-D radiotherapy (4DRT), where the temporal changes in anatomy during the delivery of radiotherapy are explicitly considered in real time, is emerging as a new method to reduce these known sources of uncertainty. Fluoroscopic, real-time tumor-tracking technology using internal fiducial markers near the tumor has ± 2 mm accuracy, and has achieved promising clinical results when used with X-ray therapy. Instantaneous irradiation based on real-time verification of internal fiducial markers is considered the minimal requisite for real-time 4DRT of lung cancers at present. Real-time tracking radiotherapy using gamma rays from positron emitters in tumors is in the preclinical research stage, but has been successful in experiments in small animals. Real-time tumor tracking via spot-scanning proton beam therapy has the capability to cure large lung cancers in motion, and is expected to be the next-generation real-time 4DRT.

Quinpirole elicits differential in vivo changes in the pre- and postsynaptic distributions of dopamine D₂ receptors in mouse striatum: relation to cannabinoid-1 (CB₁) receptor targeting

RATIONALE

The nucleus accumbens (Acb) shell and caudate-putamen nucleus (CPu) are respectively implicated in the motivational and motor effects of dopamine, which are mediated in part through dopamine D₂-like receptors (D₂Rs) and modulated by activation of the cannabinoid-1 receptor (CB₁R). The dopamine D(₂/D3) receptor agonist, quinpirole elicits internalization of D₂Rs in isolated cells; however, dendritic and axonal targeting of D₂Rs may be highly influenced by circuit-dependent changes in vivo and potentially influenced by endogenous CB₁R activation.

OBJECTIVE

We sought to determine whether quinpirole alters the surface/cytoplasmic partitioning of D₂Rs in striatal neurons in vivo.

METHODS

To address this question, we examined the electron microscopic immunolabeling of D₂ and CB₁ receptors in the Acb shell and CPu of male mice at 1 h following a single subcutaneous injection of quinpirole (0.5 mg/kg) or saline, a time point when quinpirole reduced locomotor activity.

RESULTS

Many neuronal profiles throughout the striatum of both treatment groups expressed the D₂R and/or CB₁R. As compared with saline, quinpirole-injected mice showed a significant region-specific decrease in the plasmalemmal and increase in the cytoplasmic density of D₂R-immunogold particles in postsynaptic dendrites without CB₁R-immunolabeling in the Acb shell. However, quinpirole produced a significant increase in the plasmalemmal density of D₂R immunogold in CB₁R negative axons in both the Acb shell and CPu.

CONCLUSIONS

Our results provide in vivo evidence for agonist-induced D₂R trafficking that is inversely related to CB₁R distribution in postsynaptic neurons of Acb shell and in presynaptic axons in this region and in the CPu.

Assessment of essential and nonessential metals and different metal exposure biomarkers in the human placenta in a population from the south of Portugal

The general population is exposed to metals as trace amounts of metallic compounds are present in air, water, and food. Information on background exposures and biomarker concentrations of environmental chemicals in the general Portuguese population is limited. Therefore, the purpose of this study was to determine the levels of important nonessential metals with recognized toxicity cadmium (Cd) and lead (Pb) and essential metals copper (Cu), nickel (Ni), chromium (Cr), and zinc (Zn) in placentas of mothers living in south Portugal (Algarve). Due to the difficulty in establishing the effects of chemicals in a complex and variable environment, this study also aimed to examine the response of biomarkers, such as biochemical changes that occurs at subcellular levels in the presence of contaminants. The investigated biomarkers in placentas indicative of metal exposure or damage included the metallothioneins (MT), delta-aminolevulinic acid dehydratase (ALAD) (specific for Pb), and lipid peroxidation (LPO) as an index of oxidative stress damage. Moreover, HJ-BIPLOT was applied in order to identify and categorize mothers vulnerable to environmental contamination in this region. Metal concentrations in the placenta were not excessive but within the range found in most European studies. In general, the biomarkers MT and LPO were positively correlated with metal levels, while with ALAD the opposite occurred, indicating the selected battery of biomarkers were suitable to study the effects of metals on human placenta. Further, the application of multivariate analysis with HJ-BIPLOT showed that most significant factors contributing to maternal and fetal exposures via placenta were dietary and smoking habits.

A closer look at the role of urotensin II in the metabolic syndrome

Urotensin II (UII) is a vasoactive peptide that was first discovered in the teleost fish, and later in mammals and humans. UII binds to the G protein coupled receptor GPR14 (now known as UT). UII mediates important physiological and pathological actions by interacting with its receptor. The metabolic syndrome (MetS) is described as cluster of factors such as obesity, dyslipidemia, hypertension, and insulin resistance (IR), further leading to development of type 2 diabetes mellitus and cardiovascular diseases. UII levels are upregulated in patients with the MetS. Evidence directly implicating UII in every risk factor of the MetS has been accumulated. The mechanism that links the different aspects of the MetS relies primarily on IR and inflammation. By directly modulating both of these factors, UII is thought to play a central role in the pathogenesis of the MetS. Moreover, UII also plays an important role in hypertension and hyperlipidemia thereby contributing to cardiovascular complications associated with the MetS.

The lifelong effects of early childhood adversity and toxic stress

Advances in fields of inquiry as diverse as neuroscience, molecular biology, genomics, developmental psychology, epidemiology, sociology, and economics are catalyzing an important paradigm shift in our understanding of health and disease across the lifespan. This converging, multidisciplinary science of human development has profound implications for our ability to enhance the life prospects of children and to strengthen the social and economic fabric of society. Drawing on these multiple streams of investigation, this report presents an ecobiodevelopmental framework that illustrates how early experiences and environmental influences can leave a lasting signature on the genetic predispositions that affect emerging brain architecture and long-term health. The report also examines extensive evidence of the disruptive impacts of toxic stress, offering intriguing insights into causal mechanisms that link early adversity to later impairments in learning, behavior, and both physical and mental well-being. The implications of this framework for the practice of medicine, in general, and pediatrics, specifically, are potentially transformational. They suggest that many adult diseases should be viewed as developmental disorders that begin early in life and that persistent health disparities associated with poverty, discrimination, or maltreatment could be reduced by the alleviation of toxic stress in childhood. An ecobiodevelopmental framework also underscores the need for new thinking about the focus and boundaries of pediatric practice. It calls for pediatricians to serve as both front-line guardians of healthy child development and strategically positioned, community leaders to inform new science-based strategies that build strong foundations for educational achievement, economic productivity, responsible citizenship, and lifelong health.

Role of oxidative stress in the pathogenesis of nonalcoholic steatohepatitis

The worldwide rising prevalence of obesity and insulin resistance is associated with a parallel increase in nonalcoholic fatty liver disease (NAFLD). NAFLD is characterized by excess accumulation of triglyceride in the hepatocyte due to increased inflow of free fatty acids and/or de novo lipogenesis caused by various drugs and multiple defects in energy metabolism. Accumulation of lipids in the hepatocyte impairs the oxidative capacity of the mitochondria, increasing the reduced state of the electron transport chain (ETC) complexes and stimulating peroxisomal and microsomal pathways of fat oxidation. The consequent increased generation of reactive oxygen species (ROS) and reactive aldehydic derivatives causes oxidative stress and cell death, via ATP, NAD, and glutathione depletion and DNA, lipid, and protein damage. Oxidative stress also triggers production of inflammatory cytokines, causing inflammation and a fibrogenic response. This ultimately results in the development of nonalcoholic steatohepatitis (NASH), which can result in end-stage liver disease. The current therapeutic strategies for NASH treatment are mostly directed toward correction of the risk factors. Stimulation of mitochondrial function may also prevent NASH development, protecting the cell against the increased flux of reduced substrates to the ETC and ROS generation.

L-amino acid oxidases: properties and molecular mechanisms of action

During previous decade L-amino acid oxidases (LAAO) attracted the steady interest of researchers due to their poly functional effects on different biological systems. The review summarizes information concerning the sources, structure, phisico-chemical and catalytical properties of LAAO which exhibit antibacterial, antifungal, antiprotozoal, antiviral effects as well as the ambiguous action on platelet aggregation. Special attention is devoted to the elucidation of molecular mechanisms of LAAO action. It is proposed that the unique properties of LAAO are based on their catalytic reaction, which causes the decrease of L-amino acid levels, including the essential amino acids and formation of hydrogen peroxide. The action of liberated H2O2 on cells involves the synthesis of oxygen reactive species and the development of necrotic and apoptotic pathways of cell death. The presence of carbohydrate moieties in LAAO molecules promotes their attachment to cell's surface and creation of high H2O2 local concentrations. The wide range of LAAO biological effects is undoubtedly connected with their important functional roles in the organism. In particular, it was shown that in the mice brain the LAAO-catalyzed reaction is the single pathway of L-lysine degradation, while in the mice milk LAAO carry out the antibacterial effect and in human leucocytes LAAO take part in fulfilling their defending role. Protector action may be also attributed to the oxidases from the other numerous sources: microscopic fungi, snake venoms and sea inhabitants.