121 research outputs found
Hesperidin Ameliorates Immobilization-Stress-Induced Behavioral and Biochemical Alterations and Mitochondrial Dysfunction in Mice by Modulating Nitrergic Pathway
The present study was aimed to evaluate the protective effect of hesperidin against immobilization-stress-induced alterations in biochemical, behavioral, and mitochondrial functions in mice. In many instances neuroscientists have reported that acute immobilization stress for 6 h resulted in anxiety and impaired locomotor activity due to excess oxidative-nitrergic stress, depletion of antioxidant defense mechanisms, and mitochondrial dysfunction in animals. In the present study, 6 h of acute immobilization stress had significantly altered the behavioral (anxiety and memory) and biochemical parameters coupled with mitochondrial dysfunction in Swiss albino mice. Fourteen days of pretreatment with Hesperidin (50 and 100 mg/kg, p.o.) significantly and dose-dependently inhibited the behavioral and biochemical alterations and mitochondrial dysfunction caused by acute immobilization stress. Furthermore, pre-treatment of l-arginine (50 mg/kg, i.p.), a nitric oxide precursor, reversed the protective effect of Hesperidin (50 and 100 mg/kg) (P < 0.05). In contrast, pretreatment of l-NAME
(5 mg/kg, i.p.), a nitric oxide synthase inhibitor, potentiated the protective effect of Hesperidin (P < 0.05). These results suggest the possible involvement of nitrergic pathway in the protective effect Hesperidin against immobilization-stress-induced behavioral, biochemical, and mitochondrial dysfunction in mice
Physico-chemical and microbial analysis of water samples in Anakapalli Municipal Corporation
An investigation of microbiological and physico-chemical properties of drinking water samples from five different locations in Anakapalli municipal corporation. The water samples are subject to physico-chemical analysis by standard methods. The microbial isolation was done by a streak plate method on nutrient agar and on selective media for their identification. The final identification was done according to the Bergey’s Manual. The physico-chemical characters of all the five drinking water samples were within the recommended permissible level of WHO. The total plate count was above the WHO guideline values (<10CFU’s/ml) in the five water samples. The highest count was noticed in S5 sample (54 CFU’s/ml). The highest coliform count was observed in S3 samples (11/100 ml). Six isolates of bacteria namely: E.coli, Enterobacter aerogenes, Klebsiella pneumonia, Salmonella, Shigella, and Staphylococcus were isolated, which are highly pathogenic, the result of the study indicates that the water in Andhra University pump houses is highly contaminated and not safe for drinking and utility purposes. The study therefore, stresses on the need to control the fecal pollution of water bodies
Mahanine restores RASSF1A expression by down-regulating DNMT1 and DNMT3B in prostate cancer cells
BACKGROUND: Hypermethylation of the promoter of the tumor suppressor gene RASSF1A silences its expression and has been found to be associated with advanced grade prostatic tumors. The DNA methyltransferase (DNMT) family of enzymes are known to be involved in the epigenetic silencing of gene expression, including RASSF1A, and are often overexpressed in prostate cancer. The present study demonstrates how mahanine, a plant-derived carbazole alkaloid, restores RASSF1A expression by down-regulating specific members of the DNMT family of proteins in prostate cancer cells. RESULTS: Using methylation-specific PCR we establish that mahanine restores the expression of RASSF1A by inducing the demethylation of its promoter in prostate cancer cells. Furthermore, we show that mahanine treatment induces the degradation of DNMT1 and DNMT3B, but not DNMT3A, via the ubiquitin-proteasome pathway; an effect which is rescued in the presence of a proteasome inhibitor, MG132. The inactivation of Akt by wortmannin, a PI3K inhibitor, results in a similar down-regulation in the levels DNMT1 and DNMT3B. Mahanine treatment results in a decline in phospho-Akt levels and a disruption in the interaction of Akt with DNMT1 and DNMT3B. Conversely, the exogenous expression of constitutively active Akt inhibits the ability of mahanine to down-regulate these DNMTs, suggesting that the degradation of DNMT1 and DNMT3B by mahanine occurs via Akt inactivation. CONCLUSIONS: Taken together, we show that mahanine treatment induces the proteasomal degradation of DNMT1 and DNMT3B via the inactivation of Akt, which facilitates the demethylation of the RASSF1A promoter and restores its expression in prostate cancer cells. Therefore, mahanine could be a potential therapeutic agent for advanced prostate cancer in men when RASSF1A expression is silenced
Neuropathological Responses to Chronic NMDA in Rats Are Worsened by Dietary n-3 PUFA Deprivation but Are Not Ameliorated by Fish Oil Supplementation
Background
Dietary long-chain n-3 polyunsaturated fatty acid (PUFA) supplementation may be beneficial for chronic brain illnesses, but the issue is not agreed on. We examined effects of dietary n-3 PUFA deprivation or supplementation, compared with an n-3 PUFA adequate diet (containing alpha-linolenic acid [18:3 n-3] but not docosahexaenoic acid [DHA, 22:6n-3]), on brain markers of lipid metabolism and excitotoxicity, in rats treated chronically with NMDA or saline. Methods
Male rats after weaning were maintained on one of three diets for 15 weeks. After 12 weeks, each diet group was injected i.p. daily with saline (1 ml/kg) or a subconvulsive dose of NMDA (25 mg/kg) for 3 additional weeks. Then, brain fatty acid concentrations and various markers of excitotoxicity and fatty acid metabolism were measured. Results
Compared to the diet-adequate group, brain DHA concentration was reduced, while n-6 docosapentaenoic acid (DPA, 22:5n-6) concentration was increased in the n-3 deficient group; arachidonic acid (AA, 20:4n-6) concentration was unchanged. These concentrations were unaffected by fish oil supplementation. Chronic NMDA increased brain cPLA2 activity in each of the three groups, but n-3 PUFA deprivation or fish oil did not change cPLA2 activity or protein compared with the adequate group. sPLA2 expression was unchanged in the three conditions, whereas iPLA2 expression was reduced by deprivation but not changed by supplementation. BDNF protein was reduced by NMDA in N-3 PUFA deficient rats, but protein levels of IL-1β, NGF, and GFAP did not differ between groups. Conclusions
N-3 PUFA deprivation significantly worsened several pathological NMDA-induced changes produced in diet adequate rats, whereas n-3 PUFA supplementation did not affect NMDA induced changes. Supplementation may not be critical for this measured neuropathology once the diet has an adequate n-3 PUFA content
Chronic NMDA administration to rats increases brain pro-apoptotic factors while decreasing anti-Apoptotic factors and causes cell death
<p>Abstract</p> <p>Background</p> <p>Chronic <it>N</it>-Methyl-d-aspartate (NMDA) administration to rats is reported to increase arachidonic acid signaling and upregulate neuroinflammatory markers in rat brain. These changes may damage brain cells. In this study, we determined if chronic NMDA administration (25 mg/kg i.p., 21 days) to rats would alter expression of pro- and anti-apoptotic factors in frontal cortex, compared with vehicle control.</p> <p>Results</p> <p>Using real time RT-PCR and Western blotting, chronic NMDA administration was shown to decrease mRNA and protein levels of anti-apoptotic markers Bcl-2 and BDNF, and of their transcription factor phospho-CREB in the cortex. Expression of pro-apoptotic Bax, Bad, and 14-3-3ζ was increased, as well as Fluoro-Jade B (FJB) staining, a marker of neuronal loss.</p> <p>Conclusion</p> <p>This alteration in the balance between pro- and anti-apoptotic factors by chronic NMDA receptor activation in this animal model may contribute to neuronal loss, and further suggests that the model can be used to examine multiple processes involved in excitotoxicity.</p
Sustained proliferation in cancer: mechanisms and novel therapeutic targets
Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression
A multi-targeted approach to suppress tumor-promoting inflammation
Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes
Mechanical and Water Intake Properties of Banana-Carbon Hybrid Fiber Reinforced Polymer Composites
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Regulation by diet and liver of brain metabolism of nutritionally essential polyunsaturated fatty acids
It is possible to inject radiolabeled polyunsaturated fatty acids (PUFAs) intravenously to quantify rates of brain and liver PUFA metabolism in the intact organism, in relation to diet, aging or disease. Because circulating α-linolenic acid (α-LNA, 18:3n-3) and linoleic acid (LA, 18:2n-6) in plasma do not contribute to brain docosahexaenoic acid (DHA, 22:6n-3) or arachidonic acid (AA, 20:4n-6), respectively, and DHA and AA cannot be synthesized de novo in vertebrate tissue, rates of incorporation of circulating DHA or AA into brain provide exact measurements of their rates of consumption by brain. Using positron emission tomography imaging, we reported that the adult human brain consumes AA and DHA at rates of 17.8 and 4.6 mg/day, respectively, and that the rate of AA consumption doesn’t change with age. In unanesthetized adult rats fed an n-3 PUFA “adequate” diet containing 4.6% (of total fatty acids) α-LNA as its only n-3 PUFA, the liver secretes DHA derived from circulating α-LNA ten-times faster than the brain consumes DHA; thus the liver is capable of supplying all the brain’s DHA. With a low dietary α-LNA level, rat liver coefficients of α-LNA conversion to DHA are increased because of increased liver elongase and desaturase activities, and DHA loss from brain is slowed due to downregulated DHA-metabolizing enzymes, including Ca2+-independent phospholipase A2 (iPLA2). The n-3 PUFA “deficient” diet also increases brain expression of AA-metabolizing enzymes, cytosolic cPLA2, secretory sPLA2 and cyclooxygenase-2, and the brain docosapentaenoic acid (22:5n-6) concentration. These changes, plus reduced expression of brain derived neurotrophic factor (BDNF) caused by the “deficient” diet, likely increase brain vulnerability to excitotoxicity and inflammation
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