Knowledge of nosocomial infections and multiresistant bacteria in the general population: results of a street interview.
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Adolescent↗
Biomedical subjects
I Zhang
Publications and source records attributed to I Zhang.
The effect of polymorphisms of MTHER gene and vitamin B on hyperhomocysteinemia.
The relationship between hyperhomocysteinemia and coronary artery disease (CAD) was investigated and the influence of environmental factors (Folate, VitB12) and genetic factors [N5, N10-methylenetetrahydrofolate reductase gene (MTHFR) or MTHFR gene mutation] on plasma homocysteine (Hcy) levels and the risk of CAD observed. Fifty-one CAD patients and 30 CAD-free subjects were recruited in the study. The polymorphisms of MTHFR gene were analyzed by PCR-RFLP and plasma total Hcy levels were measured by high performance liquid chromatography with fluorescence detection. Plasma folate and vitamin B12 concentrations were measured by an automated chemiluminescence method. It was found that mean total plasma Hcy concentrations were significantly higher in CAD patients than in CAD-free subjects (P < 0.01). The differences were also apparent among the three genotypes of MTHFR gene in CAD group (P < 0.05). There was no significant difference in the genotype distributions and allele frequencies between the two groups. A strong inverse correlation was found between folate or vitamin B12 and plasma Hcy levels according to MTHFR genotype (P < 0.01). It was concluded that hyperhomocysteinemia is a new independent risk factor for CAD. However, MTHFR gene mutation alone does not relate significantly to the morbidity of CAD since hyperhomocysteinemia and its influence on the risk of CAD are decided by both environmental and genetic factors. Supplementary treatment with vitamins B can effectively lower the plasma levels of Hcy, thus maybe reducing the risk of CAD.
Aged↗
The nucleation of receptor-mediated endocytosis.
A theory of the mechanical origins of receptor-mediated endocytosis shows that a spontaneous membrane complex formation can provide the stimulus for a local membrane motion toward the cytosol. This motion is identified with a nucleation stage of receptor-mediated endocytosis. When membrane complexes cluster, membrane deformation is predicted to be most rapid. The rate of growth of membrane depressions depends upon the relative rates of approach of aqueous cytosolic and extracellular fluids toward the cell membrane. With cytosolic and extracellular media characterized by apparent viscosities, the rate of growth of membrane depressions is predicted to increase as the extracellular viscosity nears the apparent viscosity of the cytosol and then to decrease when the extracellular viscosity exceeds that of the cytosol. To determine whether these trends would be apparent in the overall endocytosis rate constant, an experimental study of transferrin-mediated endocytosis in two different cell lines was conducted. The experimental results reveal the same dependence of internalization rate on extracellular viscosity as predicted by the theory. These and other comparisons with experimental data suggest that the nucleation stage of receptor-mediated endocytosis is important in the overall endocytosis process.
Biophysical Phenomena↗
Spontaneous vesicle formation at lipid bilayer membranes.
Unilamellar vesicles are observed to form spontaneously at planar lipid bilayers agitated by exothermic chemical reactions. The membrane-binding reaction between biotin and streptavidin, two strong transmembrane neutralization reactions, and a weak neutralization reaction involving an "antacid" buffer, all lead to spontaneous vesicle formation. This formation is most dramatic when a viscosity differential exists between the two phases bounding the membrane, in which case vesicles appear exclusively in the more viscous phase. A hydrodynamic analysis explains the phenomenon in terms of a membrane flow driven by liberated reaction energy, leading to vesicle formation. These results suggest that energy liberated by intra- and extracellular chemical reactions near or at cell and internal organelle membranes can play an important role in vesicle formation, membrane agitation, or enhanced transmembrane mass transfer.
Bacterial Proteins↗
The prognostic significance of histomorphometry and immunohistochemistry in giant cell tumors of bone.
Eighty-two cases of giant cell tumor (GCT) were reviewed. Hematoxylin-eosin-and hematoxylin, phloxine, saffron, and alcian green-stained sections (82 cases) were examined for mitotic rate, the number of giant cells, and the pleomorphism of the stromal cells. In 29 cases, the tumor was stained for CD68, alpha 1-antichymotrypsin (AIACT), S100 protein, Muramidase, and von Willebrand factor (factor VIII). The staining properties of mononuclear and multinucleated giant cells were compared. Morphometric analysis was performed on 14 cases with a LECO 2001 computer-assisted image analyzer (LECO Instruments Ltd, Mississauga, Ontario, Canada) and included absolute cell count, nuclear area, perimeter, roughness, roundness, and aspect and nuclear versus cytoplasmic ratios, measured both in the stromal cells and giant cells. The cases were divided into four groups: (1) cases with metastasis, (2) cases with recurrence, (3) cases with both metastasis and recurrence, and (4) cases with neither metastasis nor recurrence. Immunohistochemistry revealed a stronger AIACT than muramidase positivity in general. The staining was stronger in stromal cells than in giant cells. Giant cells in all tumors were positive for CD68. Stromal cells showed weaker positivity for the same stain. The number of asymmetrical mitotic figures was significantly greater in group 3 than in group 4 (P < .05). Morphometric assessment has identified a statistically significant difference in the aspect ratio and the roundness of the nuclei between these two groups. The other parameters did not differ significantly. In this article, the significance of these findings in prognostication and the histogenesis of the giant cell tumor are discussed. Their clinical applicability is yet to be determined.
Adolescent↗
Hydrogels with enhanced mass transfer for transdermal drug delivery.
The sonophoretic transport rates of monomeric insulin and vasopressin across human skin in vitro in the presence of a 20 kHz ultrasound field are shown to differ substantially depending on whether molecules enter the skin from a saline solution or from a viscous ultrasonic coupling medium (specifically, a methyl cellulose hydrogel or viscous sol). Theoretically, the reduction in sonophoretic transport caused by the hydrogels can be explained by boundary layers that form within the hydrogel owing to the relatively rapid rate of molecular transport across the (ultrasonically) permeated stratum corneum as well as poor diffusive mass transfer between the skin and gel. The results of in vitro experiments performed with an ac current accompanying the ultrasound show that the mass-transfer barrier posed by the hydrogel can be eliminated for both vasopressin and insulin by suppressing the diffusive boundary layers, indicating that relatively high rates of sonophoretic molecular transport across human skin are achievable when hydrogels are used as the ultrasound coupling medium as long as method is used to induce molecular mixing within the gel.
Biological Transport↗
T cell vaccination in multiple sclerosis.
T cell responses to myelin basic protein (MBP) are implicated to play an important role in the pathogenesis of multiple sclerosis (MS). These MBP autoreactive T cells are found to undergo in vivo activation and clonal expansion in patients with MS. They accumulate in the brain compartment and may reside in the brain lesions of patients with MS. As MBP-reactive T cells potentially hold a central position in initiation and perpetuation of the brain inflammation, specific immune therapies designed to deplete them may improve the clinical course of the disease. In this paper, the therapeutic potential of T cell vaccination in the treatment of MS is discussed in context of its immunological and clinical effect. The results of our phase one clinical trial indicate that T cell vaccination with inactivated MBP autoreactive T cells induces specific regulatory T cell network of the host immune system to deplete circulating MBP-reactive T cells in a clonotype-specific fashion. The immunity induced by T cell vaccination is clonotype-specific and long-lasting. Our longitudinal clinical evaluation further suggests a moderate reduction of rate of clinical exacerbation, disability score and the brain lesions (measured by magnetic resonance imaging) in vaccinated patients, as compared to matched controls. Our study should encourage further investigation on the treatment efficacy of T cell vaccination and further improvement for its clinical application.
Autoantibodies↗