Aerobiological monitoring for fungal spores in a rehabilitation hospital in Northern Italy

In the setting of an aerobiological study of confined environments and environmental prevention of nosocomial infections, aerobiological monitoring of 22 areas in Montescano Medical Rehabilitation Centre (Pavia) was performed in three different months: February, May, and August, 1994. A Lanzoni 3000 spore trap was used for the monitoring. Examination of the results showed that, in the environments monitored, the indoor presence of fungi increased progressively over the three periods considered. The behaviour of individual genera of fungi differed. In the winter periodPenicillium andAspergillus were the most commonly encountered genera.Cladosporium was the dominant genus from the spring to the summer while the yeasts had their maximum counts in the spring morning. The use of air conditioning, combined with the low air exchange between outdoors and indoors in some of the environments certainly played a part in the low concentrations of these latter aerofungi.     

Analysis of some Filipino perspectives on ethical issues in multi-country collaborative research: a case of deep listening

The discussion on ethical issues, it is said, should not be confined to experts but should be extended to patients and local communities, because of the real need to engage stakeholders and non-stakeholders alike not only in carrying out any biomedical research project, but also in the drafting and legislation of bioethics instruments. Several local and inter-country consultations have already been conducted in furtherance of this goal, but there is much left to be desired in them. The consultations may have helped in articulating local principles, but not in making the instruments embody these principles. As such, instruments turn incompossible, i.e. the principles and actions they legitimate are not performable. In an ethnographic study conducted in the Philippines, for example, paragraphs 29 and 30 of the Declaration of Helsinki and CIOMS guidelines 8 and 15 are construed as not only contradictory to one another but also to local principles. This problem can be solved by taking deliberate steps to ensure that consultations are grounded in ethnographic data about local principles, which the instruments would embody. A steering committee can be of help in gathering ethnographic data, in conducting consultations at the local level, and in providing a venue for discourse on various bioethical issues.     

Vibrio cholerae persistence in aquatic environments and colonization of intestinal cells: involvement of a common adhesion mechanism

Forty-one Tnpho A mutants of Vibrio cholerae O1 classical strain CD81 were analyzed for their ability to interact with chitin particles, Tigriopus fulvus copepods and the Intestine 407 cell line compared to the parent strain. Thirteen mutants were less adhesive than CD81; in particular, T21, T33 and T87 were less adhesive towards all substrates and insensitive to inhibition by N-acetyl glucosamine (GlcNAc). By SDS-PAGE analysis of sarkosyl-insoluble membrane proteins (siMPs) isolated from mutants and parent, it was found that a 53 kDa siMP is missing in T21, T33 and T87 mutants. It is hypothesized that this protein might have the function to mediate adherence to GlcNAc-containing substrates both in the aquatic environment and in human intestine.     

Genetic diversity of Cylindrospermopsis strains (cyanobacteria) isolated from four continents

The genetic diversity of Cylindrospermopsis strains (cyanobacteria) was examined using mainly the 16S-23S internally transcribed spacer (ITS1) sequences. Strains were grouped in three clusters: (i) America, (ii) Europe, and (iii) Africa and Australia. These results suggested a recent spread of Cylindrospermopsis across the American and European continents from restricted warm refuge areas instead of exchanges between continents. On the other hand, they also suggested a recent colonization of Australia by African strains.     

Tissue remodeling in Guinea pig lateral prostate at different ages after estradiol treatment

Estrogen seems to have an essential role in the fibromuscular growth characteristic of benign prostatic hyperplasia (BPH). This paper describes the effects of chronic estradiol treatment on Guinea pig prostatic stroma at different ages. Tissues from experimental animals were studied by histological and histochemical procedures, morphometric-stereological analysis and transmission electron microscopy (TEM). Marked fibromuscular hypertrophy was observed after estradiol treatment in animals of pre-pubertal and adult ages. Increases in the density and thickness of the collagen and elastic fibers were observed by histochemistry. TEM revealed wide distributions of collagen fibrils and large elastic fibers adjacent to the epithelial basal lamina and between the stromal cells, establishing contacts between them. These results indicate that the Guinea pig prostate simulates the stromal modifications observed in BPH in some aged animals after estrogen treatment at different ages, making it a good model for this disease.     

Asymptomatic Helicobacter pylori infection increases asymmetric dimethylarginine levels in healthy subjects

BACKGROUND: Chronic infections have been demonstrated to be early factors of atherosclerosis and cardiovascular diseases, and their relevance increases when they are caused by agents with extremely broad spectrum of disease outcome such as Helicobacter pylori. The consequent endothelial impairment leads to a reduced bioavailability of nitric oxide. Increasing evidences have pointed out that the endogenous inhibitor of nitric oxide synthase, asymmetric dimethylarginine, defined as a risk factor for cardiovascular disease, may increase in infections and plays an important role impairing the vascular functions of the endothelium. Starting from these findings, we aim to investigate whether H. pylori may affect asymmetric dimethylarginine levels. MATERIALS AND METHODS: The study was carried out on a group of 186 subjects (age 46.2 +/- 14.9 years). We evaluated asymmetric dimethylarginine, symmetric dimethylarginine, L-arginine, presence of H. pylori by 13C-urea breath test, and the main parameters of glyco and lipo metabolic balance. RESULTS: Increased levels of asymmetric dimethylarginine were found in H. pylori-positive subjects with respect to H. pylori-negative subjects (0.46 x/ / 1.13 versus 0.42 x/ / 1.23 mol/l, p < .001, respectively). No differences were detected in L-arginine levels between the two groups. Multiple regression analysis performed in H. pylori-positive subjects and H. pylori-negative subjects showed profound differences in the variables related to asymmetric dimethylarginine (R2 = 66.9%, p < .01 versus 34.3%, p < .01, respectively) and symmetric dimethylarginine (R2 = 39.2%, p < .01 versus 20.6%, p = .09, respectively) levels. CONCLUSIONS: Our data clearly demonstrate that H. pylori infection increases asymmetric dimethylarginine levels. Moreover, this infection causes a profound metabolic modification that alters the role of the known determinants of asymmetric dimethylarginine levels. We conclude that H. pylori infection must be taken into account as a cause of increased asymmetric dimethylarginine levels and that the eradication of H. pylori may therefore lead to a decrease in asymmetric dimethylarginine levels, which is a further reason for the reduction of the risk for cardiovascular disease in this large portion of population.     

A modified tandem affinity purification tag technique for the purification of protein complexes in mammalian cells

The tandem affinity purification (TAP) tag technique has been used with success to identify under nondenaturing conditions protein complexes in yeast. The technique can be used in mammalian cells, but we found that the original technique does not yield enough recovery for the identification of proteins when mammalian cells growing in monolayer have to be used. We present here a modified TAP tag technique that allows sufficient recovery of proteins from mouse fibroblasts growing in monolayer cultures. The recovery allows protein identification by mass spectrometry.     

Extracellular matrix proteoglycans control the fate of bone marrow stromal cells

Extracellular matrix glycoproteins and proteoglycans bind a variety of growth factors and cytokines thereby regulating matrix assembly as well as bone formation. However, little is known about the mechanisms by which extracellular matrix molecules modulate osteogenic stem cells and bone formation. Using mice deficient in two members of the small leucine-rich proteoglycans, biglycan and decorin, we uncovered a role for these two extracellular matrix proteoglycans in modulating bone formation from bone marrow stromal cells. Our studies showed that the absence of the critical transforming growth factor-beta (TGF-beta)-binding proteoglycans, biglycan and decorin, prevents TGF-beta from proper sequestration within the extracellular matrix. The excess TGF-beta directly binds to its receptors on bone marrow stromal cells and overactivates its signaling transduction pathway. Overall, the predominant effect of the increased TGF-beta signaling in bgn/dcn-deficient bone marrow stromal cells is a "switch in fate" from growth to apoptosis, leading to decreased numbers of osteoprogenitor cells and subsequently reduced bone formation. Thus, biglycan and decorin appear to be essential for maintaining an appropriate number of mature osteoblasts by modulating the proliferation and survival of bone marrow stromal cells. These findings underscore the importance of the micro-environment in controlling the fate of adult stem cells and reveal a novel cellular and molecular basis for the physiological and pathological control of bone mass.