Purification and properties of two distinct groups of ADH isozymes from Chinese hamster liver

Two major classes of alcohol dehydrogenase isozymes have been purified from Chinese hamster liver. The two isozyme classes have the same subunit molecular weights but different electrophoretic mobilities. They have a similar range of substrates but different KROM values and sensitivities to the inhibitor pyrazole. The ADHs are immunologically related as determined by Ouchterlony double diffusion experiments. These results suggest that the isozymes are encoded by different structural gene loci derived from a common ancestral gene.Financial support was provided by the National Cancer Institute of Canada and the Medical Research Council of Canada, Grant MT4860. J.-P. Thirion is a Research Scholar of the Science Research Council of Quebec.     

Host resistance to infection: genetic control of lipopolysaccharide responsiveness by TOLL-like receptor genes.

Gram-negative bacterial lipopolysaccharide evokes a protective inflammatory response in the normal host. Through genetic analysis of mutant mice, the gene encoding Toll-like receptor 4 (Tlr4) was recently identified as a critical component of this host defense mechanism. Tlr4 is a member of an ancient gene family that regulates antimicrobial host defense in plants, invertebrates and mammals.     

Release of extracellular purines from plant roots and effect on ion fluxes

Extracellular purine nucleotides appear capable of regulating plant development, defence and stress responses by acting in part as agonists of plasma membrane calcium channels. Factors stimulating ATP release include wounding, osmotic stress and elicitors. Here we show that exogenous abscisic acid and L-glutamate can also cause ATP accumulation around Arabidopsis thaliana roots. Release of ADP from root epidermis would trigger ionotropic receptor-like activity in the plasma membrane, resulting in transient elevation of cytosolic free calcium. Root epidermal protoplasts (expressing aequorin as a cytosolic free calcium reporter) can support an extracellular ADP-induced cytosolic calcium elevation in the presence of an extracellular reductant. This confirms that ADP could elicit calcium-based responses distinct to those of ATP, which have been shown previously to involve production of extracellular reactive oxygen species.     

Hospitalizations among adults with chronic kidney disease in the United States: A cohort study

BackgroundAdults with chronic kidney disease (CKD) are hospitalized more frequently than those without CKD, but the magnitude of this excess morbidity and the factors associated with hospitalizations are not well known.Methods and findingsData from 3,939 participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study between 2003 and 2008 at 7 clinical centers in the United States were used to estimate primary causes of hospitalizations, hospitalization rates, and baseline participant factors associated with all-cause, cardiovascular, and non-cardiovascular hospitalizations during a median follow up of 9.6 years. Multivariable-adjusted Poisson regression was used to identify factors associated with hospitalization rates, including demographics, blood pressure, estimated glomerular filtration rate (eGFR), and proteinuria. Hospitalization rates in CRIC were compared with rates in the Nationwide Inpatient Sample (NIS) from 2012. Of the 3,939 CRIC participants, 45.1% were female, and 41.9% identified as non-Hispanic black, with a mean age of 57.7 years, and the mean eGFR is 44.9 ml/min/1.73m². CRIC participants had an unadjusted overall hospitalization rate of 35.0 per 100 person-years (PY) [95% CI: 34.3 to 35.6] and 11.1 per 100 PY [95% CI: 10.8 to 11.5] for cardiovascular-related causes. All-cause, non-cardiovascular, and cardiovascular hospitalizations were associated with older age (≥65 versus 45 to 64 years), more proteinuria (≥150 to <500 versus <150 mg/g), higher systolic blood pressure (≥140 versus 120 to <130 mmHg), diabetes (versus no diabetes), and lower eGFR (<60 versus ≥60 ml/min/1.73m²). Non-Hispanic black (versus non-Hispanic white) race/ethnicity was associated with higher risk for cardiovascular hospitalization [rate ratio (RR) 1.25, 95% CI: 1.16 to 1.35, p-value < 0.001], while risk among females was lower [RR 0.89, 95% CI: 0.83 to 0.96, p-value = 0.002]. Rates of cardiovascular hospitalizations were higher among those with ≥500 mg/g of proteinuria irrespective of eGFR. The most common causes of hospitalization were related to cardiovascular (31.8%), genitourinary (8.7%), digestive (8.3%), endocrine, nutritional or metabolic (8.3%), and respiratory (6.7%) causes. Hospitalization rates were higher in CRIC than the NIS, except for non-cardiovascular hospitalizations among individuals aged >65 years. Limitations of the study include possible misclassification by diagnostic codes, residual confounding, and potential bias from healthy volunteer effect due to its observational nature.ConclusionsIn this study, we observed that adults with CKD had a higher hospitalization rate than the general population that is hospitalized, and even moderate reductions in kidney function were associated with elevated rates of hospitalization. Causes of hospitalization were predominantly related to cardiovascular disease, but other causes contributed, particularly, genitourinary, digestive, and endocrine, nutritional, and metabolic illnesses. High levels of proteinuria were observed to have the largest association with hospitalizations across a wide range of kidney function levels.

Hsiang-Yu Chen and colleagues report the factors associated with hospitalization in patients with Chronic Kidney Disease.     

Halothane alters contractility and Ca2+ transport in ventricular myocytes from streptozotocin-induced diabetic rats

General anaesthetics have previously been shown to have profound effects on myocardial function. Moreover, many patients suffering from diabetes mellitus are anaesthetised during surgery. This study investigated compromised functioning of cardiac myocytes from streptozotocin (STZ)-induced diabetic rats and the additive effects of halothane on these dysfunctions. Ventricular myocytes were isolated from 8 to 12 weeks STZ-treated rats. Contraction and intracellular free calcium concentration ([Ca²⁺] _i ) were measured in electrically field-stimulated (1 Hz) fura-2-AM-loaded cells using a video-edge detection system and a fluorescence photometry system, respectively. L-type Ca²⁺ current was measured in whole cell, voltage-clamp mode. Halothane significantly (p < 0.01) depressed the amplitude and the time course of the Ca²⁺ transients in a similar manner in myocytes from control and STZ-treated rats. However, the effect of halothane on the amplitude of shortening and L-type Ca²⁺ current was more pronounced in myocytes from STZ-treated animals compared to age-matched controls. Myofilament sensitivity to Ca²⁺ was significantly (p < 0.01) increased in myocytes from STZ-treated rats compared to control. However, in the presence of halothane the myofilament sensitivity to Ca²⁺ was significantly (p < 0.05) reduced to a greater extent in myocytes from STZ-treated rats compared to controls. In conclusion, these results show that contractility, Ca²⁺ transport and myofilament sensitivity were all altered in myocytes from STZ-treated rats and these processes were further altered in the presence of halothane suggesting that hearts from STZ-induced diabetic rats are sensitive to halothane. (Mol Cell Biochem 261: 251–261, 2004)     

Toward optical spectroscopy-guided lung biopsy: Demonstration of tissue-type classification

The diagnostic yield of standard tissue-sampling modalities of suspected lung cancers, whether by bronchoscopy or interventional radiology, can be nonoptimal, varying with the size and location of lesions. What is needed is an insitu sensor, integrated in the biopsy tool, to objectively distinguish among tissue types in real time, not to replace biopsy with an optical diagnostic, but to verify that the sampling tool is properly located within the target lesion. We investigated the feasibility of elastic scattering spectroscopy (ESS), coupled with machine learning, to distinguish lung lesions from the various nearby tissue types, in a study with freshly-excised lung tissues from surgical resections. Optical spectra were recorded with an ESS fiberoptic probe in different areas of the resected pulmonary tissues, including benign-margin tissue sites as well as the periphery and core of the lesion. An artificial-intelligence model was used to analyze, retrospectively, 2032 measurements from excised tissues of 35 patients. With high accuracy, ESS was able to distinguish alveolar tissue from bronchi, alveolar tissue from lesions, and bronchi from lesions. This ex vivo study indicates promise for ESS fiberoptic probes to be integrated with surgical intervention tools, to improve reliability of pulmonary lesion targeting.     

Delaying virus maturation for a higher yield of cell associated virus antigens

Negligible amounts of virus were released when infected cells were maintained in low ionic strength medium. The cells accumulated a high titre of virus and its specific antigenic proteins, detected by complement-fixation test. The procedure has potential for production of virus subunit vaccines.     

Empirical performance evaluation of schedulers for cluster of workstations

Cluster computing is receiving exponential popularity as a choice for high performance computing. This is mainly due to its effective cost performance ratio. Resource management systems (RMS) are the key component to manage the resources of clusters efficiently and have a very vital role in the performance of distributed parallel systems especially a job scheduling module. In this paper, we have empirically evaluated four resource management systems (SGE, TORQUE, and MAUI Scheduler and SLURM) with special focus on job scheduler component. These schedulers have been evaluated on a more comprehensive set of metrics such as throughput, CPU, memory and network utilization. Experiments were carried out on three different size testbeds with a range of scheduler configurations such as FCFS, Backfilling, Fair share and SJF scheduling techniques.     

Preliminary studies on some coliphages from Kuwait

Seasonal data for raw sewage indicated a higher concentration of bacteriophages in the warmer months compared with the cooler months. Regardless of the amount of phages in the raw sewage and the time of year the efficiency of removal was as high as 83-96% for effluent II and 93-98% for sludge II. Four major types of plaque sizes were identified as Q1, Q2, Q3 and Q4. Although all isolates contained DNA, they showed variation in host range and heat sensitivity from 50 degrees C to 80 degrees C.