Attenuation of Dichlorvos-Induced Microglial Activation and Neuronal Apoptosis by 4-Hydroxy TEMPO

The neurotoxic consequences of acute high-level as well as chronic low-level organophosphates exposure are associated with a range of abnormalities in nerve functions. Previously, we have shown that after 24 h of dichlorvos exposure, microglia become activated and secrete pro-inflammatory molecules like nitric oxide, tumour necrosis factor-α and interleukin-1β. Here, we extended our findings and focused on the neuronal damage caused by dichlorvos via microglial activation. For this, neurons and microglia were isolated separately from 1-day-old Wistar rat pups. Microglia were treated with dichlorvos for 24 h and supernatant was collected (dichlorvos-induced conditioned medium, DCM). However, when 4-hydroxy TEMPO (4-HT) pretreatment was given, we observed significant attenuation of dichlorvos-induced microglial activation; we also collected the supernatant of this culture (4-HT + DCM, TDCM). Next, we checked the effects of DCM on neurons and found heavy loss in viability as evident from NF-H immunostaining and MTT results, whereas dichlorvos alone-treated neurons showed comparatively less damage. However, we observed significant increase in neuronal viability when cells were treated with TDCM. Semi-quantitative PCR and western blot results revealed significant increase in p53, Bax and cytochrome c levels along with caspase 3 activation after 24 h of DCM treatment. However, TDCM-treated neurons showed significant decrease in the expression of these pro-apoptotic molecules. Taken together, these findings suggest that 4-HT can significantly attenuate dichlorvos-induced microglial activation and prevent apoptotic neuronal cell death.     

Illegal harvesting and livestock grazing threaten the endangered orchid Dactylorhiza hatagirea (D. Don) Soó in Nepalese Himalaya

Harvesting of orchids for medicine and salep production is a traditional practice, and increasing market demand is spurring illegal harvest. Ethno‐ecological studies in combination with the effect of anthropogenic disturbance are lacking for orchids. We compared population density and structure, and tuber biomass of Dactylorhiza hatagirea (D. Don) Soó for three years in two sites: Manang, where harvesting of medicinal plants was locally regulated (protected), and Darchula, where harvesting was locally unregulated (unprotected). Six populations were studied along an elevation gradient by establishing 144 temporary plots (3 × 3 m²) from 3,400 to 4,600 m elevations. Mean density of D. hatagirea was significantly higher in the locally protected (1.31 ± 0.17 plants/m²) than in the unprotected (0.72 ± 0.06 plants/m²) site. The protected site showed stable population density with high reproductive fitness and tuber biomass over the three‐year period. A significant negative effect (p < .1) of relative radiation index (RRI) on the density of the adult vegetative stage and a positive effect of herb cover on juvenile and adult vegetative stages were found using mixed zero‐inflated Poisson (mixed ZIP) models. The densities of different life stages were highly sensitive to harvesting and livestock grazing. Significant interactions between site and harvesting and grazing indicated particularly strong negative effects of these disturbances on densities of juvenile and adult reproductive stages in the unprotected site. Semi‐structured interviews were conducted with informants (n = 186) in the villages and at the ecological survey sites. Our interview results showed that at the protected site people are aware of the conservation status and maintain sustainable populations, whereas the opposite was the case at the unprotected site where the populations are threatened. Sustainability of D. hatagirea populations, therefore, largely depends on controlling illegal and premature harvesting and unregulated livestock grazing, thus indicating the need for permanent monitoring of the species.     

Neuroprotective Role of Intermittent Hypobaric Hypoxia in Unpredictable Chronic Mild Stress Induced Depression in Rats

Hypoxic exposure results in several pathophysiological conditions associated with nervous system, these include acute and chronic mountain sickness, loss of memory, and high altitude cerebral edema. Previous reports have also suggested the role of hypoxia in pathogenesis of depression and related psychological conditions. On the other hand, sub lethal intermittent hypoxic exposure induces protection against future lethal hypoxia and may have beneficial effect. Therefore, the present study was designed to explore the neuroprotective role of intermittent hypobaric hypoxia (IHH) in Unpredictable Chronic Mild Stress (UCMS) induced depression like behaviour in rats. The IHH refers to the periodic exposures to hypoxic conditions interrupted by the normoxic or lesser hypoxic conditions. The current study examines the effect of IHH against UCMS induced depression, using elevated plus maze (EPM), open field test (OFT), force swim test (FST), as behavioural paradigm and related histological and molecular approaches. The data indicated the UCMS induced depression like behaviour as evident from decreased exploration activity in OFT with increased anxiety levels in EPM, and increased immobility time in the FST; whereas on providing the IHH (5000m altitude, 4hrs/day for two weeks) these behavioural changes were ameliorated. The morphological and molecular studies also validated the neuroprotective effect of IHH against UCMS induced neuronal loss and decreased neurogenesis. Here, we also explored the role of Brain-Derived Neurotrophic Factor (BDNF) in anticipatory action of IHH against detrimental effect of UCMS as upon blocking of BDNF-TrkB signalling the beneficial effect of IHH was nullified. Taken together, the findings of our study demonstrate that the intermittent hypoxia has a therapeutic potential similar to an antidepressant in animal model of depression and could be developed as a preventive therapeutic option against this pathophysiological state.     

Right atrial appendage tachycardia: A rare cause of tachycardia induced cardiomyopathy in a 4-year-old child

We present a rare case of tachycardiomyopathy in a 4-year-old girl. The child had incessant atrial tachycardia (AT) and refractory heart failure. Right atrial appendage (RAA) was localised as the source of the ectopic tachycardia. The child underwent successful radiofrequency ablation (RFA) using 3-D electroanatomical mapping. Fluoroscopy was used sparingly only to rule out underlying anomalies. The left ventricular functions returned to normal by one month after the procedure. RAA AT is rare in very young children and usually necessitates surgical appendectomies. RFA is a challenge in such age groups and there are very few published literature on RAA AT in very young children.     

Exogenous Nitric Oxide Delays Ripening and Maintains Postharvest Quality of Pointed Gourd During Storage

This study was aimed to assess the effect of nitric oxide (NO; 1 and 2 mM) on shelf life and quality of pointed gourd. Fruits were stored at 12 °C for 14 days with simulated ambient storage for 3 days (7 + 3 and 14 + 3) to mimic the marketing period. NO treatment significantly improved the postharvest shelf life as compared to control samples. The fruits underwent to the application of NO (2 mM) effectively maintained the chlorophyll, phenolics, antioxidant activity and membrane integrity. It suppressed weight loss, yellow color development, lignin formation, and electrolytic leakage. Activity of enzymes (PAL and LOX) was also influenced positively by NO application. Postharvest treatment of NO (2 mM) could be suggested as an eco-safe and effective technique for enhancing the shelf life without hampering quality of pointed gourd.

     

Length-Weight Relationship analysis of four freshwater fish Species from Doyang reservoir at Nagaland,India

The LWRs (length–weight relationships) of four freshwater fish species from medium categorized Doyang reservoir at Wokha District, Nagaland were studied, namely as Garra naganensis Hora, 1921; Devario naganensis Chaudhuri, 1912; Chagunius nicholsi Myers, 1924 and Schistura manipurensis Chaudhuri, 1912. Fish sample were collected in every 15 days interval by cast-nets (1.0 × 1.0 cm mesh size covering the 4.5 m² areas), gill-nets (0.4–5.0 cm mesh size), scoop-nets (mesh size with 0.3 × 0.3 cm to 0.6 × 0.6 cm) and also from the local fishermen in between July 2017 to January 2019. The regression value of slope (b) is fallen into 2.860–3.115 range with significant correlation values (r² ≥ .960).     

Effects of Thrombin on the Neurovascular Unit in Cerebral Ischemia

Cerebral ischemia is a cerebrovascular disease with high morbidity and mortality that poses a significant burden on society and the economy. About 60% of cerebral ischemia is caused by thrombus, and the formation of thrombus proceeds from insoluble fibrin, following its transformation from liquid fibrinogen. In thrombus-induced ischemia, increased permeability of the blood–brain barrier (BBB), followed by the extravasation of blood components into the brain results in an altered brain microenvironment. Changes in the brain microenvironment affect brain function and the neurovascular unit (NVU), the working unit of the brain. Recent studies have reported that coagulation factors interact with the NVU and its components, but the specific function of this interaction is highly speculative and warrants further investigations. In this article, we reviewed the role of coagulation factors in cerebral ischemia and the role of coagulation factors in thrombosis. Additionally, the influence of thrombin on the NVU is introduced, as well as in the function of NVU, which may help to explore part of brain injury mechanism during ischemia. Lastly, we propose some novel therapeutic approaches on ischemic stroke by reducing the risk of coagulation.