Stimulation of cannabinoid receptor agonist 2-arachidonylglycerol by chronic ethanol and its modulation by specific neuromodulators in cerebellar granule neurons

AbstractIn an earlier study, we reported that chronic ethanol (EtOH) stimulates the formation of anandamide in human SK-N-SH cells. In the present study, we investigated the effect of chronic EtOH on the formation of yet another cannabinoid receptor (CB1) agonist, 2-arachidonylglycerol (2-AG), in cerebellar granule neurons (CGNs). The formation of 2-[3H]AG without any stimulation was more pronounced in the older cultures than in younger cultures. Exposure of CGNs to EtOH led to a significant increase in the level of 2-[3H]AG (P<0.05). Incubation with the anandamidehydrolase inhibitor phenylmethylsulfonyl fluoride and EtOH did result in an additive increase in 2-[3H]AG, but did not with E-6-(bromomethylene)tetrahydro-3-(1-naphthelenyl)-2H-pyran-2-one. The formation of 2-[3H]AG was enhanced by ionomycin in both the control and EtOH-exposed CGNs, and the ionomycin-stimulated 2-[3H]AG synthesis was inhibited by the intracellular chelating agent 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid. Further, glutamate increased the formation of 2-[3H]AG only in control CGNs. MK-801 inhibited the EtOH-induced 2-[3H]AG synthesis, suggesting the participation of intracellular Ca2+ in EtOH-induced 2-[3H]AG synthesis. The dopamine receptor (D2) agonist did not modify the 2-AG synthesis in either the control or EtOH-exposed CGNs. However, the D2 receptor antagonist inhibited the EtOH-induced formation of 2-[3H]AG. The EtOH-induced 2-[3H]AG formation was inhibited by SR141716A and pertussis toxin, suggesting the CB1 receptor- and Gi/o-protein-mediated regulation of 2-AG. The observed increase in 2-AG level in CGNs is possibly a mechanism for neuronal adaptation to the continuous presence of EtOH. These findings indicate that some of the pharmacological actions of EtOH may involve alterations in the endocannabinoid signaling system

Rickettsial neglected zoonoses: prevalence of scrub typhus at central Karnataka

Background: Fever of unknown Origin (FUO) has many multiple causes such as enteric fever, malaria, dengue, tuberculosis, brucellosis. But scrub typhus is less known cause in Indian scenario. The present study reports the prevalence of scrub typhus at central Karnataka and compares the sensitivity and specificity of Weil-Felix test and the IgM ELISA in the detection of infection.Methods: 368 serum samples of FUO cases were collected. Weil-Felix test was performed and also analyzed for IgM antibodies to Orienta tsutsugamushi by IgM ELISA test along with haematological and biochemical investigations.Results: Out of 368 patients of fever of unknown origin, 94 cases were positive by OXK antigens by Weil Felix test and 61 were positive by ELISA test for ST IgM antibodies. Fever was the most common clinical presentation occurring in ST IgM ELISA positive cases, followed by myalgia in 90.1% cases, headache in 77%, hepatomegaly in 65.5%, splenomegaly in 62.2% and rashes were seen in 29.5% patients. Eschar was seen in 13.1% patients, pneumonia in 3.2% and meningo-encephalitis in 1.6%. Sensitivity and specificity of WFT in relation to IgM ELISA at a titre of 160 was 81.97% and 85.67% respectively.Conclusions: With the growing number of cases detected in India, scrub typhus is fast emerging as a public health threat and also due to limited diagnostics leading to underreporting, Weil Felix test could be used in adjunct with Enzyme-linked immunosorbent assay and blood parameters in the diagnosis of rickettsial diseases

Repercussion of biofilm and antibiotic resistance in ventilator associated pneumonia

Background: Ventilator associated pneumonia contributes nearly half of all cases of hospital-acquired pneumonia. Drug resistance among ventilator associated pneumonia has obligation of device withdrawal in order to achieve clinical and microbiological cure. Aim of the study was to determine the relationship between antibiotic resistance of Endotracheal tube biofilm and pulmonary pathogens in ventilator-associated pneumonia.Methods: A descriptive analytical study of 100 clinically suspected VAP patients was done. Patients were divided into group-I and Group-II based on intubation duration for 1-5 days and 6-10 days respectively. Endotracheal aspirate (ETA) was collected from clinically diagnosed cases and processed as per standard microbiological techniques. Bacterial counts ≥106 CFU/ml for quantitative cultures was considered significant. Biofilm production was detected by tissue culture plate, tube method and Congo red method. Multi-variant analysis was done to find out the association of the various factors.Results: Klebsiella pneumoniae was the predominant bacteria isolated followed by Acinetobacter baumannii. 45% of Gram negative bacteria were β lactamase producers. In Biofilm production by tissue culture method, 72% of the isolates showed either strong or moderate biofilm formation. Multivariate analysis revealed that bacteria isolated from VAP occurring after 5 days of mechanical ventilation among prior antibiotic-treated patients were resistant to all the antibiotics tested.Conclusions: Bacterial aetiology, biofilm formation and drug resistance has ramification on outcome of ventilator associated pneumonia. Hence, advised that it is crucial to remove ET tube in regular interval to prevent biofilm formation and sequential cultures to obtain the microbiological information which enables better patient care.

Retinal changes in Alzheimer's disease— integrated prospects of imaging, functional and molecular advances

Alzheimer's Disease (AD) is a devastating neurodegenerative disorder of the brain, clinically characterised by cognitive deficits that gradually worsen over time. There is, at present, no established cure, or disease-modifying treatments for AD. As life expectancy increases globally, the number of individuals suffering from the disease is projected to increase substantially. Cumulative evidence indicates that AD neuropathological process is initiated several years, if not decades, before clinical signs are evident in patients, and diagnosis made. While several imaging, cognitive, CSF and blood-based biomarkers have been proposed for the early detection of AD; their sensitivity and specificity in the symptomatic stages is highly variable and it is difficult to justify their use in even earlier, pre-clinical stages of the disease. Research has identified potentially measurable functional, structural, metabolic and vascular changes in the retina during early stages of AD. Retina offers a distinctively accessible insight into brain pathology and current and developing ophthalmic technologies have provided us with the possibility of detecting and characterising subtle, disease-related changes. Recent human and animal model studies have further provided mechanistic insights into the biochemical pathways that are altered in the retina in disease, including amyloid and tau deposition. This information coupled with advances in molecular imaging has allowed attempts to monitor biochemical changes and protein aggregation pathology in the retina in AD. This review summarises the existing knowledge that informs our understanding of the impact of AD on the retina and highlights some of the gaps that need to be addressed. Future research will integrate molecular imaging innovation with functional and structural changes to enhance our knowledge of the AD pathophysiological mechanisms and establish the utility of monitoring retinal changes as a potential biomarker for AD

Ferrochelatase is a therapeutic target for ocular neovascularization

Ocular neovascularization underlies major blinding eye diseases such as “wet” age-related macular degeneration (AMD). Despite the successes of treatments targeting the vascular endothelial growth factor (VEGF) pathway, resistant and refractory patient populations necessitate discovery of new therapeutic targets. Using a forward chemical genetic approach, we identified the heme synthesis enzyme ferrochelatase (FECH) as necessary for angiogenesis in vitro and in vivo. FECH is overexpressed in wet AMD eyes and murine choroidal neovascularization; siRNA knockdown of Fech or partial loss of enzymatic function in the Fechm1Pas mouse model reduces choroidal neovascularization. FECH depletion modulates endothelial nitric oxide synthase function and VEGF receptor 2 levels. FECH is inhibited by the oral antifungal drug griseofulvin, and this compound ameliorates choroidal neovascularization in mice when delivered intravitreally or orally. Thus, FECH inhibition could be used therapeutically to block ocular neovascularization

Dry Sliding-Friction and Wear Behavior of Hot-Extruded Al6061/Si3N4/Cf Hybrid Metal Matrix Composite.

The effects of reinforcement addition and hot extrusion on the microstructures, micro hardness, friction, and wear behavior of aluminium (Al) hybrid composite were investigated. Al6061 dispersed with electroless nickel-coated Si3N4 (6wt.%) and copper-coated carbon fiber (Cf) (1wt.%) hybrid composites was developed through stir casting followed by hot extrusion. Optical micro structural studies confirmed that the size of reinforcements decreased, and their orientations were in the extrusion direction. The decrease in the grain size (29%) of hybrid composites was larger than that in the grain size of matrix alloys under hot-extruded conditions. The synthesized hot-extruded Al6061 hybrid composite exhibited a lower coefficient of friction (51%) and high wear resistance (39%) compared with the hotextruded Al6061base alloy