Usefulness of the stomacher in a microbiological regulatory laboratory.

The relative efficiency of the Waring blender, the Stomacher 400, and the Stomacher 3500 for preparing food samples for microbiological analysis was studied. Comparative aerobic plate count (APC) values were determined on 671 samples, representing 30 categories of foods. Of the 26 categories of nonfatty foods, the blender gave significantly higher geometric mean APC values than those given by the Stomacher 400 and the Stomacher 3500 in 65 and 69 percent of the categories, respectively. In a comparison of the two Stomacher models, the Stomacher 400 gave significantly higher geometric mean APC values than these given by the Stomacher 3500 in 73 percent of the food categories. Addition of Tween 80 to four categories of fatty foods at concentrations of 0.5, 1.0, and 2.0 percent did not raise the APC values given by either model of stomacher to the levels given by the Waring blender. Overall, the efficiency of both models of Stomacher, relative to the blender and to each other, was specific and depended upon the particular food being analyzed.     

Oxidative/nitrative stress in the pathogenesis of systemic sclerosis: are antioxidants beneficial?

Abstract

Systemic sclerosis (SSc) is a multisystem autoimmune disease: characterised from the clinical side by progressive vasculopathy and fibrosis of the skin and different organs and from the biochemical side by fibroblast deregulation with excessive production of collagen and increased expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). The latter contributes to an overproduction of reactive oxygen species that through an autocrine loop maintains NOX4 in a state of activation. Reactive oxygen and nitrogen species are implicated in the origin and perpetuation of several clinical manifestations of SSc having vascular damage in common; attempts to dampen oxidative and nitrative stress through different agents with antioxidant properties have not translated into a sustained clinical benefit. Objective of this narrative review is to describe the origin and clinical implications of oxidative and nitrative stress in SSc, with particular focus on the central role of NOX4 and its interactions, to re-evaluate the antioxidant approaches so far used to limit disease progression, to appraise the complexity of antioxidant treatment and to touch on novel pathways elements of which may represent specific treatment targets in the not so distant future.     

Biotechnical Characteristics of Root Systems of Typical Mediterranean Species

Quantifying patterns of fine root dynamics is crucial to the understanding of ecosystem structure and function, and in predicting how ecosystems respond to disturbance. Part of this understanding involves consideration of the carbon lost through root turnover. In the context of the rainfall pattern in the tropics, it was hypothesised that rainfall would strongly influence fine root biomass and longevity. A field study was conducted to determine root biomass, elemental composition and the influence of rainfall on longevity of fine roots in a tropical lowland evergreen rainforest at Danum Valley, Sabah, Malaysia. A combination of root coring, elemental analysis and rhizotron observation methods were used. Fine (less than 2 mm diameter) root biomass was relatively low (1700 kg ha −1) compared with previously described rainforest data. Standing root biomass was positively correlated with preceding rainfall, and the low fine root biomass in the dry season contained higher concentrations of N and lower concentrations of P and K than at other times. Observations on rhizotrons demonstrated that the decrease in fine root biomass in the dry season was a product of both a decrease in fine root length appearance and an increase in fine root length disappearance. Fitting an overall model to root survival time showed significant effects of rainfall preceding root disappearance, with the hazard of root disappearance decreasing by 8 for each 1 mm increase in the average daily (30 day) rainfall preceding root disappearance. While it is acknowledged that other factors have a part to play, this work demonstrates the importance of rainfall and soil moisture in influencing root biomass and root disappearance in this tropical rainforest.     

Human epicardium-derived cells fuse with high efficiency with skeletal myotubes and differentiate toward the skeletal muscle phenotype: a comparison study with stromal and endothelial cells

Recent studies have underscored a role for the epicardium as a source of multipotent cells. Here, we investigate the myogenic potential of adult human epicardium-derived cells (EPDCs) and analyze their ability to undergo skeletal myogenesis when cultured with differentiating primary myoblasts. Results are compared to those obtained with mesenchymal stromal cells (MSCs) and with endothelial cells, another mesodermal derivative. We demonstrate that EPDCs spontaneously fuse with pre-existing myotubes with an efficiency that is significantly higher than that of other cells. Although at a low frequency, endothelial cells may also contribute to myotube formation. In all cases analyzed, after entering the myotube, nonmuscle nuclei are reprogrammed to express muscle-specific genes. The fusion competence of nonmyogenic cells in vitro parallels their ability to reconstitute dystrophin expression in mdx mice. We additionally show that vascular cell adhesion molecule 1 (VCAM1) expression levels of nonmuscle cells are modulated by soluble factors secreted by skeletal myoblasts and that VCAM1 function is required for fusion to occur. Finally, treatment with interleukin (IL)-4 or IL-13, two cytokines released by differentiating myotubes, increases VCAM1 expression and enhances the rate of fusion of EPDCs and MSCs, but not that of endothelial cells.     

Cytogenetic study of a cell line of human penile cancer

A cell line of penile cancer from a 60-year-old Ugandan black patient has been studied by the authors. Transmission and scanning electron microscopy showed a large number of blebs and microvilli at cell surface; desmosomes were evident at TEM. Cytogenetic investigation (R-, C-, Nor-banding) showed the frequent presence of some markers: del(1p),del(1q),iso(3q),der(4),del(8p),11q+, t rob(13;14), 14p+, t rob(21;21). The epidemiology, geographical distribution, and aetiological role of human papilloma virus type 16 and herpes simplex type 2 are discussed.     

Developing and applying a benthic index of estuarine condition for the Virginian Biogeographic Province

A benthic index of estuarine condition was constructed for the Virginian Biogeographic Province (from Cape Cod, Massachusetts, to the mouth of Chesapeake Bay, Virginia) with data collected during summers of 1990 through 1993 by the US EPA’s Environmental Monitoring and Assessment Program (EMAP). Forty-eight metrics, based on attributes of the macrobenthos, were considered for the index, including measures of biodiversity, community condition, individual health, functional organization, and taxonomic composition. Salinity was correlated significantly with some of the metrics. Therefore, some metrics were normalized for salinity. The data used to develop the index (the calibration data) included equal numbers of reference and degraded sites, distributed equally across three salinity zones (<5, 5–18, >18‰). An independent set of data was used for validation. Linear discriminant analysis identified combinations of metrics that could best discriminate reference from degraded sites. The targets for correct classification were 90% of the sites for the calibration data and 80% for the validation data. Six combinations of metrics were identified. The final index was based on the ecological interpretation and relevance of the individual metrics and the ability to meet the calibration and validation targets. The final index consisted of three metrics: a positive contribution from salinity-normalized Gleason’s D (a biodiversity metric), and negative contributions from two taxonomic composition metrics, abundances of spionid polychaetes and of salinity-normalized tubificid oligochaetes. The index correctly classified 87% of reference and 90% of degraded sites in the calibration data and 88% of reference and 81% of degraded sites in the validation data. The index correctly classified sites over the full range of salinity (tidal-fresh to marine waters) and across grain sizes (silt–clay to sand).