Bacterial adaptation to the gut environment favors successful colonization

Rodent models harboring a simple yet functional human intestinal microbiota provide a valuable tool to study the relationships between mammals and their bacterial inhabitants. In this study, we aimed to develop a simplified gnotobiotic mouse model containing 10 easy-to-grow bacteria, readily available from culture repositories, and of known genome sequence, that overall reflect the dominant commensal bacterial makeup found in adult human feces. We observed that merely inoculating a mix of fresh bacterial cultures into ex-germ free mice did not guarantee a successful intestinal colonization of the entire bacterial set, as mice inoculated simultaneously with all strains only harbored 3 after 21 d. Therefore, several inoculation procedures were tested and levels of individual strains were quantified using molecular tools. Best results were obtained by inoculating single bacterial strains into individual animals followed by an interval of two weeks before allowing the animals to socialize to exchange their commensal microbes. Through this procedure, animals were colonized with almost the complete bacterial set (9/10). Differences in the intestinal composition were also reflected in the urine and plasma metabolic profiles, where changes in lipids, SCFA, and amino acids were observed. We conclude that adaptation of bacterial strains to the host’s gut environment (mono-colonization) may predict a successful establishment of a more complex microbiota in rodents.     

Hypertensive Retinopathy: Incidence,Risk Factors,and Comorbidities

We aimed to determine the prevalence and risk factors of retinopathy in hypertensive outpatients. Demographic data, accompanying diseases, anthropometric measurements, and blood and urine biochemistry of 655 hypertensive patients were evaluated. Hypertensive retinopathy rate was 66.3% (grade 1, 33.6%; grade 2, 32.7%). Age, duration of hypertension, and systolic blood pressure levels were significant risk factors for retinopathy (P = .048, P = .035, and P = .012, respectively). Any correlations between retinopathy and gender, body mass index, biochemistry, and associated diseases were not found. This study shows that the degree and duration of hypertension increases the incidence of retinopathy. Low-grade retinopathy seems not to be associated with other cardiovascular risks.     

Strategies for long-term gene expression in the skin to treat metabolic disorders

Due to its accessibility, size and contact with the blood circulation, the skin is an attractive target for somatic gene therapy. Permanent cutaneous expression can be achieved by genetic manipulation of epidermal keratinocytes ex vivo followed by transplantation or by local injection of viral vectors. Furthermore, progress is being made to develop topical gene transfer methods leading to permanent gene expression. There is experimental evidence showing that genetically engineered skin can produce and secrete medically relevant proteins to the circulation and also produce enzymes that can clear metabolites accumulating in various diseases. Thus, cutaneous gene transfer approaches may be relevant not only for local skin diseases, but also for certain systemic disorders.     

The physiology and toxicology of acute inhalation phosphine poisoning in conscious male rats

Phosphine (PH₃) is a toxidrome-spanning chemical that is widely used as an insecticide and rodenticide. Exposure to PH₃ causes a host of target organ and systemic effects, including oxidative stress, cardiopulmonary toxicity, seizure-like activity and overall metabolic disturbance. A custom dynamic inhalation gas exposure system was designed for the whole-body exposure of conscious male Sprague-Dawley rats (250–350?g) to PH₃. An integrated plethysmography system was used to collect respiratory parameters in real-time before, during and after PH₃ exposure. At several time points post-exposure, rats were euthanized, and various organs were removed and analyzed to assess organ and systemic effects. The 24?h post-exposure LCt₅₀, determined by probit analysis, was 23,270?ppm?×?min (32,345?mg?×?min/m³). PH₃ exposure affects both pulmonary and cardiac function. Unlike typical pulmonary toxicants, PH₃ induced net increases in respiration during exposure. Gross observations of the heart and lungs of exposed rats suggested pulmonary and cardiac tissue damage, but histopathological examination showed little to no observable pathologic changes in those organs. Gene expression studies indicated alterations in inflammatory processes, metabolic function and cell signaling, with particular focus in cardiac tissue. Transmission electron microscopy examination of cardiac tissue revealed ultrastructural damage to both tissue and mitochondria. Altogether, these data reveal that in untreated, un-anesthetized rats, PH₃ inhalation induces acute cardiorespiratory toxicity and injury, leading to death and that it is characterized by a steep dose-response curve. Continued use of our interdisciplinary approach will permit more effective identification of therapeutic windows and development of rational medical countermeasures and countermeasure strategies.     

Effect of 99 GHz continuous millimeter wave electro-magnetic radiation on E. coli viability and metabolic activity

Purpose:?To investigate time exposure dependence of continuous millimeter wave (CW) 99?GHz radiation on Escherichia coli bacterial cell viability and metabolic activity.

Materials and methods:?Suspensions of E. coli bacterial cells with an optical density of OD_660nm?=?0.1 were used for viability tests and OD_660nm?=?1.0 for metabolic activity tests. These suspensions were exposed to 99?GHz CW electromagnetic radiation, generated by a Backward Wave Oscillator (BWO) tube base instrument with a horn antenna at the BWO exit, to obtain an almost ideal Gaussian beam. Calculations of the Gaussian beam show that a power of 0.2?mW/cm² was obtained at the bacterial plane.

Results:?The experimental results show that 1 hour of exposure to 99?GHz CW electromagnetic radiation had no effect on E. coli viability and colony characterisation. In 19?h of radiation, the number of colonies forming units was half order of magnitude higher than the sham-exposed and the control. However, 19?h of exposure did not affect the E. coli metabolic activity.

Conclusions:?Exposure of E. coli to millimeter wave (MW) CW 99?GHz radiation for a short period did not affect the viability of E. coli bacterial cells. However, exposure for 19?h caused a slight proliferation but did not influence the metabolic activities of about 90 biochemical reactions that were examined. Hence, we assume that the slight proliferation (half order of magnitude) after 19?h of exposure dose not have a biological meaning.     

肝细胞移植的研究现状与进展

肝细胞移植是一种通过对获得的正常肝组织进行体外分离纯化,并将分离纯化的肝细胞植入患者体内暂时性地对遗传性代谢性肝病和急性肝衰竭等患者提供代谢性支持的新方法。经过多年的发展,肝细胞移植技术已经取得很大的进展,目前在临床应用已有成功案例,但距离临床广泛应用仍需要进一步的研究。     

Adiponectin: linking the metabolic syndrome to its cardiovascular consequences

Obesity and its related disorders, glucose intolerance, hypertension and hyperlipidemia, collectively named the metabolic syndrome, result in substantial cardiovascular morbidity and mortality. Recent data point to several underlying regulatory mechanisms through which obesity links these various outcomes. Adipose tissue is now understood to function not merely as a passive energy storage depot but as an active endocrine organ, producing a variety of bioactive substances termed adipocytokines. Adiponectin, an adipocytokine first described as the most abundant protein produced by adipocytes, appears to serve as a central regulatory protein in many of the physiologic pathways controlling lipid and carbohydrate metabolism, and to mediate various vascular processes. Adiponectin displays both anti-inflammatory and antiatherogenic properties. Unlike other adipocytokines, its levels are paradoxically decreased in obesity and insulin-resistance states including metabolic syndrome and diabetes, as well as hypertension and coronary artery disease. This review will detail the relationship of adiponectin to various features of obesity and insulin-resistance syndromes, as well as its relationship to the cardiovascular complications of these disorders.     

The association of non-HDL cholesterol with the presence of metabolic syndrome in North Indian subjects with and without CAD

Aim: The present study aims to identify which lipid parameter is significantly associated with Coronary Artery Disease (CAD) and metabolic syndrome (MetS) and also to find out the association of non-HDL cholesterol (non-HDL-C) with the presence of MetS in North Indian subjects with and without CAD.

Subjects and methods: One hundred and thirteen CAD and 140 non-CAD (controls) aged 35–75 years were recruited for the study, matched for ethnicity and geography after obtaining their written informed consent. The CAD patients were identified based on their medical diagnostic history. Height, weight, waist and hip circumferences, blood pressures (systolic and diastolic) and lipid profile were measured for all the subjects.

Results: Sixty-nine out of 113 (61.06%) of CAD and 52/140 (37.1%) of non-CAD had MetS. Age standardized prevalence of MetS was 23.2% and 16.1% in CAD and non-CAD individuals, respectively. Age standardized prevalence of metabolic abnormalities in the CAD group was in the order of abdominal obesity>non-HDL-C>systolic blood pressure (SBP) > triglyceride (TG) > total cholesterol (TC) > diastolic blood pressure (DBP) > Low Density Lipoprotein Cholesterol (LDL-C) > High Density Lipoprotein Cholesterol (HDL-C). Non-HDL-C, TG and HDL-C were found to be significantly associated with MetS.

Conclusions: TG and HDL-C are established risk components included in the characterization of MetS; but significant association of non-HDL-C with MetS in the present study is a key finding. The study focuses on the use of non-HDL-C as a simple screening tool to identify individuals with clustering metabolic abnormalities which increase the propensity for CAD.