Inhibition of Reactive Gliosis Prevents Neovascular Growth in the Mouse Model of Oxygen-Induced Retinopathy

Retinal neovascularization (NV) is a major cause of blindness in ischemic retinopathies. Previous investigations have indicated that ischemia upregulates GFAP and PDGF-B expression. GFAP overexpression is a hallmark of reactive gliosis (RG), which is the major pathophysiological feature of retinal damage. In addition, PDGF-B has been implicated in proliferative retinopathies. It was the aim of this study to gain insights on the possible pharmacological interventions to modulate PDGF-B and GFAP expression, and its influence on RG and NV. We used an array of assays to evaluate the effects of YC-1, a small molecule inhibitor of HIF-1 and a novel NO-independent activator of soluble guanylyl cyclase (sGC), on RG and NV, in vivo and in vitro. When compared to the DMSO-treated retinas, dual-intravitreal injections of YC-1, in vivo: (1) suppressed the development and elongation of neovascular sprouts in the retinas of the oxygen-induced retinopathy (OIR) mouse model; and (2) reduced ischemia-induced overexpression of GFAP and PDGF-B at the message (by 64.14±0.5% and 70.27±0.04%) and the protein levels (by 65.52±0.02% and 57.59±0.01%), respectively. In addition, at 100 µM, YC-1 treatment downregulated the hypoxia-induced overexpression of GFAP and PDGF-B at the message level in rMC-1 cells (by 71.42±0.02% and 75±0.03%), and R28 cells (by 58.62±0.02% and 50.00±0.02%), respectively; whereas, the protein levels of GFAP and PDGF-B were reduced (by 78.57±0.02% and 77.55±0.01%) in rMC-1cells, and (by 81.44±0.02% and 79.16±0.01%) in R28 cells, respectively. We demonstrate that YC-1 reversed RG during ischemic retinopathy via impairing the expression of GFAP and PDGF-B in glial cells. This is the first investigation that delves into the reversal of RG during ischemic retinal vasculopathies. In addition, the study reveals that YC-1 may exert promising therapeutic effects in the treatment of retinal and neuronal pathologies

Challenges of tuberculosis prevention through early detection of latent tuberculosis infection in new immigrants to the State of Kuwait

Introduction: Despite management advances worldwide, tuberculosis still remains a serious uncontrolled disease. The absence of either a ‘gold’ standard diagnostic test, or a conventional rapid ‘reference’ laboratory test for asymptomatic Mycobacterium tuberculosis (MTB) carriers complicates disease control. Through mandatory screening of high-risk groups, early diagnosis of latent tuberculosis infection (LTBI) cases allows recognition and better control of the tuberculosis pandemic. Materials and Methods: The current tuberculosis screening guidelines as recommended by the World Health Organization, chest X-ray and tuberculin skin test were assessed and revealed rises in TB morbidity and fatality trends in the Kuwait population (low incidence country). In order to evaluate options for LTBI diagnosis, the current work implemented a 4-month prospective, observational, repeated-measure and randomly implemented survey on 180 new immigrants to Kuwait using a structured risk factor questionnaire whilst, simultaneously evaluating the performance of the two standard diagnostics (chest X-ray and tuberculin skin test) with the new biomarker interferon gamma release assays (T-SPOT .TB test and QuantiFERON Gold In-Tube test (QNF-GIT)); which detect the release of interferon gamma (INF-γ) released from sensitization to specific MTB antigens. Results: Associations between various epidemiological risk factors - such as socio-demographic status, smoking and environmental exposure-contact - were associated in the laboratory diagnosed LTBI participants. Positive identification of LTBI prevalence detected by two radiologists was 10.1% having ‘moderate’ inter-reader agreement (Kappa = 0.505), compared to no positives being detected by three pulmonologists. TST results were negative (less than 10-mm ‘cut-off’) even in the 86.1% Bacillus Calmette-Guérin vaccinated expatriates. Estimated LTBI using QNFGIT was 28.3% compared to 41.1% positive T-SPOT .TB test. Both interferon gamma assays revealed concordant ‘abnormal’ results in 26.1% with ‘good’ agreement (kappa = 0.627). Conclusion: Detection of latent tuberculosis infection can be facilitated by introducing evidence-based diagnostic classification depending on history taking of epidemiological-related risk factors and chest X-ray plus either interferon gamma assays

Vakfı, Vakıf Yapan Özellikler

[No Abstract Available

Prevalence of Nocturnal Enuresis among Schoolchildren in Sana’a City, Yemen

Objective: To estimate the prevalence, frequency and time of nocturnal enuresis (NE) among primary schoolchildren in Sana’a city, Yemen. Methods: This was a cross-sectional study was conducted among 2689 schoolchildren in the primary schools of four randomly selected districts in Sana’a city in the period from September 2012 to December 2013. Data about sociodemographic characteristics, frequency, time, psycho-social effects and the factors possibly associated with NE among children were collected using a pre-designed questionnaire and analyzed using appropriate statistical tests. Results: The overall prevalence of NE was 11.2%, which was significantly higher among males than females (13.0% vs. 10.0%, respectively; P = 0.044) and decreased significantly with increasing age (P <0.001). More than half of children (55.3%) in Sana’a city had the habits of drinking excess fluids and tea at night and/or deep sleeping. Of physical and health disorders, difficulty in breathing and urinary tract infections were the two most frequent conditions among children with NE, being observed among 29.6% and 23.9% of cases, respectively. However, urogenital anomalies and mental retardation were the least frequent conditions in children with NE, being observed among 5.8% and 1.3% of cases, respectively. On the other hand, marital problems (24.8%) and arrival of a new baby (17.9%) were the most frequently observed social conditions among children with NE, while death in the family (8.5%) and parental separation (6.0%) were the least frequently observed conditions. Conclusions: NE is prevalent among 11.2% of schoolchildren in Sana’a city with a significantly higher, though slight, rate among males. This rate is lower than the rates reported from Aden and Mukalla cities in the country and from Saudi Arabia and Turkey. However, it is higher than those reported from Iran and Malaysia. About a third of children experience nightly NE, whereas the lowest proportion of children experience NE twice a month. The habits of drinking excess fluid and tea at night and/or deep sleeping, the disorders of difficulty in breathing and urinary tract infections and the social conditions of marital problems and arrival of a new baby are the most frequent observations among children with NE in Sana’a city

Deletion of low molecular weight protein tyrosine phosphatase (Acp1) protects against stress-induced cardiomyopathy.

The low molecular weight protein tyrosine phosphatase (LMPTP), encoded by the ACP1 gene, is a ubiquitously expressed phosphatase whose in vivo function in the heart and in cardiac diseases remains unknown. To investigate the in vivo role of LMPTP in cardiac function, we generated mice with genetic inactivation of the Acp1 locus and studied their response to long-term pressure overload. Acp1(-/-) mice develop normally and ageing mice do not show pathology in major tissues under basal conditions. However, Acp1(-/-) mice are strikingly resistant to pressure overload hypertrophy and heart failure. Lmptp expression is high in the embryonic mouse heart, decreased in the postnatal stage, and increased in the adult mouse failing heart. We also show that LMPTP expression increases in end-stage heart failure in humans. Consistent with their protected phenotype, Acp1(-/-) mice subjected to pressure overload hypertrophy have attenuated fibrosis and decreased expression of fibrotic genes. Transcriptional profiling and analysis of molecular signalling show that the resistance of Acp1(-/-) mice to pathological cardiac stress correlates with marginal re-expression of fetal cardiac genes, increased insulin receptor beta phosphorylation, as well as PKA and ephrin receptor expression, and inactivation of the CaMKIIδ pathway. Our data show that ablation of Lmptp inhibits pathological cardiac remodelling and suggest that inhibition of LMPTP may be of therapeutic relevance for the treatment of human heart failure

Gender Dimorphism in Aspartame-Induced Impairment of Spatial Cognition and Insulin Sensitivity

Previous studies have linked aspartame consumption to impaired retention of learned behavior in rodents. Prenatal exposure to aspartame has also been shown to impair odor-associative learning in guinea pigs; and recently, aspartame-fed hyperlipidemic zebrafish exhibited weight gain, hyperglycemia and acute swimming defects. We therefore investigated the effects of chronic lifetime exposure to aspartame, commencing in utero, on changes in blood glucose parameters, spatial learning and memory in C57BL/6J mice. Morris Water Maze (MWM) testing was used to assess learning and memory, and a random-fed insulin tolerance test was performed to assess glucose homeostasis. Pearson correlation analysis was used to investigate the associations between body characteristics and MWM performance outcome variables. At 17 weeks of age, male aspartame-fed mice exhibited weight gain, elevated fasting glucose levels and decreased insulin sensitivity compared to controls (P<0.05). Females were less affected, but had significantly raised fasting glucose levels. During spatial learning trials in the MWM (acquisition training), the escape latencies of male aspartame-fed mice were consistently higher than controls, indicative of learning impairment. Thigmotactic behavior and time spent floating directionless was increased in aspartame mice, who also spent less time searching in the target quadrant of the maze (P<0.05). Spatial learning of female aspartame-fed mice was not significantly different from controls. Reference memory during a probe test was affected in both genders, with the aspartame-fed mice spending significantly less time searching for the former location of the platform. Interestingly, the extent of visceral fat deposition correlated positively with non-spatial search strategies such as floating and thigmotaxis, and negatively with time spent in the target quadrant and swimming across the location of the escape platform. These data suggest that lifetime exposure to aspartame, commencing in utero, may affect spatial cognition and glucose homeostasis in C57BL/6J mice, particularly in males

In vivo antibacterial activity of whey protein derived from fermented milk of Iraqi buffalo

The present study aims to prepare fermented buffalo's milk rich with low molecular weight peptides by using lactic acid starters as a mixture. Skim milk sample was inoculated with 5% of the starter. The growing number of starter and anti-bacterial activity were studied after 24 hours of incubation. Protein and peptide concentration were determined before and after fermentation, then biological active peptides were isolated or separated and purified by gel filtration column of Sephadex G25. Finally, the antibacterial activity of the isolated peptides was studied in vivo. The results of chemical analysis of fresh and fermented milk showed that the concentrations of protein were 0.817mg/ml and 0.501mg/ml before and after fermentation, respectively either peptide concentration was 0.4mg/ml before fermentation and 0.805mg/ml after fermentation. The number of starters was determined during the fermentation process after 6, 12, 18 and 24 hours of incubation and found an increase in the number of lactic acid bacteria. The initiation number was 6.2 × 105 but after the 24 hours, the number increased of up to 1.3×106. The number of lactic bacteria decreased after 24 hours with the increase in the concentration of lactic acid combined with low pH value. Colonies of lactobacilli were isolated from fermented buffalo milk and were characterized by the typical characteristics for the purpose of a rating based on morphological and cultural characters. Gel filtration gave seventy-eight fractions. And depending on the absorbency on wavelength 280 were obtained four peaks, each peak represents a fraction. Peptide concentration was determined in each fraction, these concentrations were (0 and 0243 and 0902 and 0632) mg/ml of fraction 1, 2, 3 and 4, respectively. Fraction three contained a high concentration of peptide. The antibacterial activity of the third fraction was estimated. The results showed that the bioactive peptides of fermented milk have good efficacy in the treatment of diarrhea in laboratory animals

RNase L Mediates Transient Control of The Interferon Response Through Modulation of The Double-stranded RNA-Dependent Protein Kinase PKR

The transient control of diverse biological responses that occurs in response to varied forms of stress is often a highly regulated process. During the interferon (IFN) response, translational repression due to phosphorylation of eukaryotic initiation factor 2α, eIF2α, by the double-stranded RNA-dependent protein kinase, PKR, constitutes a means of inhibiting viral replication. Here we show that the transient nature of the IFN response against acute viral infections is regulated, at least in part, by RNase L. During the IFN antiviral response in RNase L-null cells, PKR mRNA stability was enhanced, PKR induction was increased, and the phosphorylated form of eIF2α appeared with extended kinetics compared with similarly treated wild type cells. An enhanced IFN response in RNase L-null cells was also demonstrated by monitoring inhibition of viral protein synthesis. Furthermore, ectopic expression of RNase L from a plasmid vector prevented the IFN induction of PKR. These results suggest a role for RNase L in the transient control of the IFN response and possibly of other cytokine and stress responses

RNase L Mediates Transient Control of The Interferon Response Through Modulation of The Double-stranded RNA-Dependent Protein Kinase PKR

The transient control of diverse biological responses that occurs in response to varied forms of stress is often a highly regulated process. During the interferon (IFN) response, translational repression due to phosphorylation of eukaryotic initiation factor 2α, eIF2α, by the double-stranded RNA-dependent protein kinase, PKR, constitutes a means of inhibiting viral replication. Here we show that the transient nature of the IFN response against acute viral infections is regulated, at least in part, by RNase L. During the IFN antiviral response in RNase L-null cells, PKR mRNA stability was enhanced, PKR induction was increased, and the phosphorylated form of eIF2α appeared with extended kinetics compared with similarly treated wild type cells. An enhanced IFN response in RNase L-null cells was also demonstrated by monitoring inhibition of viral protein synthesis. Furthermore, ectopic expression of RNase L from a plasmid vector prevented the IFN induction of PKR. These results suggest a role for RNase L in the transient control of the IFN response and possibly of other cytokine and stress responses

The interplay of intracellular calcium and zinc ions in response to electric field stimulation in primary rat cortical neurons in vitro

Recent pharmacological studies demonstrate a role for zinc (Zn2+) in shaping intracellular calcium (Ca2+) dynamics and vice versa in excitable cells including neurons and cardiomyocytes. Herein, we sought to examine the dynamic of intracellular release of Ca2+ and Zn2+ upon modifying excitability of primary rat cortical neurons using electric field stimulation (EFS) in vitro. We show that exposure to EFS with an intensity of 7.69 V/cm induces transient membrane hyperpolarization together with transient elevations in the cytosolic levels of Ca2+ and Zn2+ ions. The EFS-induced hyperpolarization was inhibited by prior treatment of cells with the K+ channel opener diazoxide. Chemical hyperpolarization had no apparent effect on either Ca2+ or Zn2+. The source of EFS-induced rise in Ca2+ and Zn2+ seemed to be intracellular, and that the dynamic inferred of an interplay between Ca2+ and Zn2+ ions, whereby the removal of extracellular Ca2+ augmented the release of intracellular Ca2+ and Zn2+ and caused a stronger and more sustained hyperpolarization. We demonstrate that Zn2+ is released from intracellular vesicles located in the soma, with major co-localizations in the lysosomes and endoplasmic reticulum. These studies further support the use of EFS as a tool to interrogate the kinetics of intracellular ions in response to changing membrane potential in vitro