1,067 research outputs found

    Ethanol reversal of tolerance to the respiratory depressant effects of morphine

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    Opioids are the most common drugs associated with unintentional drug overdose. Death results from respiratory depression. Prolonged use of opioids results in the development of tolerance but the degree of tolerance is thought to vary between different effects of the drugs. Many opioid addicts regularly consume alcohol (ethanol), and post-mortem analyses of opioid overdose deaths have revealed an inverse correlation between blood morphine and ethanol levels. In the present study, we determined whether ethanol reduced tolerance to the respiratory depressant effects of opioids. Mice were treated with opioids (morphine, methadone, or buprenorphine) for up to 6 days. Respiration was measured in freely moving animals breathing 5% CO(2) in air in plethysmograph chambers. Antinociception (analgesia) was measured as the latency to remove the tail from a thermal stimulus. Opioid tolerance was assessed by measuring the response to a challenge dose of morphine (10 mg/kg i.p.). Tolerance developed to the respiratory depressant effect of morphine but at a slower rate than tolerance to its antinociceptive effect. A low dose of ethanol (0.3 mg/kg) alone did not depress respiration but in prolonged morphine-treated animals respiratory depression was observed when ethanol was co-administered with the morphine challenge. Ethanol did not alter the brain levels of morphine. In contrast, in methadone- or buprenorphine-treated animals no respiratory depression was observed when ethanol was co-administered along with the morphine challenge. As heroin is converted to morphine in man, selective reversal of morphine tolerance by ethanol may be a contributory factor in heroin overdose deaths

    Heritability and major gene effects on left ventricular mass in the Chinese population: a family study

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    BACKGROUND: Genetic components controlling for echocardiographically determined left ventricular (LV) mass are still unclear in the Chinese population. METHODS: We conducted a family study from the Chin-San community, Taiwan, and a total of 368 families, 1145 subjects, were recruited to undergo echocardiography to measure LV mass. Commingling analysis, familial correlation, and complex segregation analysis were applied to detect component distributions and the mode of inheritance. RESULTS: The two-component distribution model was the best-fitting model to describe the distribution of LV mass. The highest familial correlation coefficients were mother-son (0.379, P < .0001) and father-son (0.356, P < .0001). Genetic heritability (h(2)) of LV mass was estimated as 0.268 ± 0.061 (P < .0001); it decreased to 0.153 ± 0.052 (P = .0009) after systolic blood pressure adjustment. Major gene effects with polygenic components were the best-fitting model to explain the inheritance mode of LV mass. The estimated allele frequency of the gene was 0.089. CONCLUSION: There were significant familial correlations, heritability and a major gene effect on LV mass in the population-based families

    VEGF receptors on PC12 cells mediate transient activation of ERK1/2 and Akt: comparison of nerve growth factor and vascular endothelial growth factor

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    Vascular endothelial growth factor (VEGF) and endostatin are angiogenic and anti-angiogenic molecules, respectively, that have been implicated in neurogenesis and neuronal survival. Using alkaline phosphatase fusion proteins, we show that the PC12 neuronal cell line contains cell membrane receptors for VEGF but not for endostatin and the collagen XV endostatin homologue. Immunocytochemistry confirmed that proliferating and differentiated PC12 cells express VEGF receptors 1, 2 and neuropilin-1. While no functional effects of VEGF on PC12 cell proliferation and differentiation could be observed, a slight VEGF-induced reduction of caspase-3 activity in differentiated apoptotic PC12 cells was paralleled by transient activation of ERK1/2 and Akt. In direct comparison, nerve growth factor proved to be a strikingly more potent neuroprotective agent than VEGF

    Severity of acute hepatitis and its outcome in patients with dengue fever in a tertiary care hospital Karachi, Pakistan (South Asia)

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    <p>Abstract</p> <p>Background</p> <p>Liver injury due to dengue viral infection is not uncommon. Acute liver injury is a severe complicating factor in dengue, predisposing to life-threatening hemorrhage, Disseminated Intravascular Coagulation (DIC) and encephalopathy. Therefore we sought to determine the frequency of hepatitis in dengue infection and to compare the outcome (length of stay, in hospital mortality, complications) between patients of Dengue who have mild/moderate (ALT 23-300 IU/L) v/s severe acute hepatitis (ALT > 300 IU/L).</p> <p>Methods</p> <p>A Cohort study of inpatients with dengue viral infection done at Aga Khan University Hospital Karachi. All patients (≥ 14 yrs age) admitted with diagnosis of Dengue Fever (DF), Dengue Hemorrhagic Fever (DHF) or Dengue Shock Syndrome (DSS) were included. Chi square test was used to compare categorical variables and fischer exact test where applicable. Survival analysis (Cox regression and log rank) for primary outcome was done. Student t test was used to compare continuous variables. A p value of less than or equal to 0.05 was taken as significant.</p> <p>Results</p> <p>Six hundred and ninety nine patients were enrolled, including 87% (605) patients with DF and 13% (94) patients with DHF or DSS. Liver functions tests showed median ALT of 88.50 IU/L; IQR 43.25-188 IU/L, median AST of 174 IU/L; IQR 87-371.5 IU/L and median T.Bil of 0.8 mg/dl; IQR 0.6-1.3 mg/dl. Seventy one percent (496) had mild to moderate hepatitis and 15% (103) had severe hepatitis. Mean length of stay (LOS) in patients with mild/moderate hepatitis was 3.63 days v.s 4.3 days in those with severe hepatitis (P value 0.002). Overall mortality was 33.3% (n = 6) in mild/moderate hepatitis vs 66.7% (n = 12) in severe hepatitis group (p value < 0.001). Cox regression analysis also showed significantly higher mortality in severe hepatitis group (H.R (4.91; 95% CI 1.74-13.87 and P value 0.003) and in DHF/DSS (5.43; CI 1.86-15.84 and P value 0.002). There was a significant difference for the complications like Bleeding (P value < 0.001), Acute Renal failure (ARF) (P value 0.002), Acalculus cholecystitis (P value 0.04) and encephalopathy (P value 0.02) in mild/moderate and Severe hepatitis groups respectively.</p> <p>Conclusion</p> <p>Severe hepatitis (SGPT>300IU) in Dengue is associated with prolonged LOS, mortality, bleeding and RF.</p

    Metabolic Consequences and Vulnerability to Diet-Induced Obesity in Male Mice under Chronic Social Stress

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    Social and psychological factors interact with genetic predisposition and dietary habit in determining obesity. However, relatively few pre-clinical studies address the role of psychosocial factors in metabolic disorders. Previous studies from our laboratory demonstrated in male mice: 1) opposite status-dependent effect on body weight gain under chronic psychosocial stress; 2) a reduction in body weight in individually housed (Ind) male mice. In the present study these observations were extended to provide a comprehensive characterization of the metabolic consequences of chronic psychosocial stress and individual housing in adult CD-1 male mice. Results confirmed that in mice fed standard diet, dominant (Dom) and Ind had a negative energy balance while subordinate (Sub) had a positive energy balance. Locomotor activity was depressed in Sub and enhanced in Dom. Hyperphagia emerged for Dom and Sub and hypophagia for Ind. Dom also showed a consistent decrease of visceral fat pads weight as well as increased norepinephrine concentration and smaller adipocytes diameter in the perigonadal fat pad. On the contrary, under high fat diet Sub and, surprisingly, Ind showed higher while Dom showed lower vulnerability to obesity associated with hyperphagia. In conclusion, we demonstrated that social status under chronic stress and individual housing deeply affect mice metabolic functions in different, sometime opposite, directions. Food intake, the hedonic response to palatable food as well as the locomotor activity and the sympathetic activation within the adipose fat pads all represent causal factors explaining the different metabolic alterations observed. Overall this study demonstrates that pre-clinical animal models offer a suitable tool for the investigation of the metabolic consequences of chronic stress exposure and associated psychopathologies

    Carotid Artery Intima-Media Thickness, Carotid Plaque and Coronary Heart Disease and Stroke in Chinese

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    Background: Our aim was to prospectively investigate the association between carotid artery intima-media thickness (IMT) as well as carotid plaque and incidence of coronary heart disease (CHD) and stroke in Chinese, among whom data are limited. Methods and Findings: We conducted a community-based cohort study composed of 2190 participants free of cardiovascular disease at baseline in one community. During a median 10.5-year follow up, we documented 68 new cases of coronary heart disease and 94 cases of stroke. The multivariate relative risks (RRs) associated with a change of 1 standard deviation of maximal common carotid IMT were 1.38 (95% confidence interval [CI], 1.12–1.70) for CHD and 1.47 (95% CI, 1.28–1.69) for stroke. The corresponding RRs with internal carotid IMT were 1.47 (95% CI, 1.21–1.79) for CHD and 1.52 (95% CI, 1.31–1.76) for stroke. Carotid plaque measured by the degree of diameter stenosis was also significantly associated with increased risk of CHD (p for trend<0.0001) and stroke (p for trend<0.0001). However, these associations were largely attenuated when adjusting for IMT measurements. Conclusions: This prospective study indicates a significant association between carotid IMT and incidence of CHD and stroke in Chinese adults. These measurements may be useful for cardiovascular risk assessment and stratification in Chinese

    HIV-1 subtype A infection in a community of intravenous drug users in Pakistan

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    BACKGROUND: Data on the subtypes of HIV in a population help in predicting the potential foci of epidemic, tracking the routes of infection and following the patterns of the virus' genetic divergence. Globally, the most prevalent HIV infection is the HIV-1 subtype C. In Asia, predominant subtypes of HIV-1 are B, C, and CRF-01AE. During the last few years, HIV prevalence in Pakistan has taken the form of a concentrated epidemic in at least two high risk groups, namely, Intravenous Drug Users (IDUs) and Male Sex Workers (MSWs). Factors that have facilitated the proliferation of HIV infection include transmission through a large number of repatriates and needle-sharing intravenous drug users, unscreened blood transfusions, and sexual illiteracy. The HIV subtypes infecting Pakistani populations have not been explored to date. In this study, we analyzed HIV-1 subtypes from in a high-risk community of IDUs in Karachi, the largest city of Pakistan. METHODS: Samples were collected from 34 IDUs after their informed consent. In addition, the study subjects were administered a questionnaire regarding their sexual behavior and travel history. For HIV analysis, DNA was extracted from the samples and analyzed for HIV types and subtypes using subtype-specific primers in a nested polymerase chain reaction (PCR). The results from this PCR were further confirmed using the Heteroduplex Mobility Assay (HMA). RESULTS: We found HIV-1 subtype A in all the 34 samples analyzed. A few of the study subjects were found to have a history of travel and stay in the United Arab Emirates. The same subjects also admitted to having contact with commercial sex workers during their stay abroad. CONCLUSION: Our study therefore shows clade A HIV-1 to be prevalent among the IDUs in Karachi. As the prevalence of HIV in Pakistan continues to rise, more work needs to be done to track the infection, and to analyze the strains of HIV spreading through the country

    A Plant Kavalactone Desmethoxyyangonin PreventsInflammation and Fulminant Hepatitis in Mice

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    Alpinia pricei Hayata is a Formosan plant which has been popularly used as nutraceutical or folk medicine for inflammation and various disorders. An active compound of the plant rhizomes, desmethoxyyangonin (DMY), was identified in this study for its novel effect against endotoxin lipopolysaccharide (LPS)-stimulated inflammation in murine macrophages and LPS/D-galactosamine (LPS/D-GalN)-induced fulminant hepatitis in mice. DMY was observed to significantly inhibit proliferation and activation of T cells ex vivo and the activity of several pro-inflammatory mediators in vitro. DMY also protected LPS/D-GalN−induced acute hepatic damages in mice through inhibiting aminotransferases activities and infiltrations of inflammatory macrophages, neutrophils and pathogenic T cells into the liver tissues. In addition, pretreatment with DMY significantly improved the survival rate of LPS/D-GalN−treated mice to 90% (9/10), compared to LPS/D-GalN−treated group (40%, 4/10). UPLC/MS platform-based comparative metabolomics approach was used to explore the serum metabolic profile in fulminant hepatic failure (FHF) mice with or without the DMY pretreatment. The results showed that LPS/D-GalN−induced hepatic damage is likely through perturbing amino acid metabolism, which leads to decreased pyruvate formation via catalysis of aminotransferases, and DMY treatment can prevent to a certain degree of these alterations in metabolic network in mouse caused by LPS/D-GalN. Mechanistic investigation demonstrated that DMY protects LPS or LPS/D-GalN−induced damages in cell or liver tissues mainly through de-regulating IKK/NFκB and Jak2/STAT3 signaling pathways. This report provides evidence-based knowledge to support the rationale for the use of A. pricei root extract in anti-inflammation and also its new function as hepatoprotetive agent against fulminant hepatitis

    Expression and Function of Ccbe1 in the Chick Early Cardiogenic Regions Are Required for Correct Heart Development

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    During the course of a differential screen to identify transcripts specific for chick heart/hemangioblast precursor cells, we have identified Ccbe1 (Collagen and calcium-binding EGF-like domain 1). While the importance of Ccbe1 for the development of the lymphatic system is now well demonstrated, its role in cardiac formation remained unknown. Here we show by whole-mount in situ hybridization analysis that cCcbe1 mRNA is initially detected in early cardiac progenitors of the two bilateral cardiogenic fields (HH4), and at later stages on the second heart field (HH9-18). Furthermore, cCcbe1 is expressed in multipotent and highly proliferative cardiac progenitors. We characterized the role of cCcbe1 during early cardiogenesis by performing functional studies. Upon morpholino-induced cCcbe1 knockdown, the chick embryos displayed heart malformations, which include aberrant fusion of the heart fields, leading to incomplete terminal differentiation of the cardiomyocytes. cCcbe1 overexpression also resulted in severe heart defects, including cardia bifida. Altogether, our data demonstrate that although cardiac progenitors cells are specified in cCcbe1 morphants, the migration and proliferation of cardiac precursors cells are impaired, suggesting that cCcbe1 is a key gene during early heart development.FCT [SFRH/BD/65628/2009, SFRH/BPD/86497/2012, SFRH/BPD/41081/2007]; F.C.T.B.I. fellowship [PTDC/SAU-BID/114902/ 2009]; FCT; Institute for Biotechnology Bioengineering (Centro Biomedicina Molecular e Celular (IBB/CBME), Laboratorio Associado (LA) in the frame of Project [PestOE/EQB/LA0023/2013]info:eu-repo/semantics/publishedVersio
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