The Eiken Latex test for detection of a cryptococcal antigen in cryptococcosis

A latex agglutination test for cryptococcal antigen, the Eiken Latex test (Eiken, Tokyo, Japan), was compared with a monoclonal antibody-based agglutination assay, Pastorex^® Cryptococcus (Diagnostics Pasteur, Marneur-la-Coquette, France). In a murine model of disseminated cryptococcosis, the kinetics of the antigen titers by the Eiken Latex were similar to those by the Pastorex^® Cryptococcus, but sensitivity was much higher. In HIV-negative patients with pulmonary cryptococcosis, a cryptococcal antigen was detected in 6 of 10 patients by the Eiken Latex test and in only 3 of those patients by the Pastorex^® Cryptococcus. The results indicate that the Eiken Latex is more sensitive for the detection of the cryptococcal antigen, even in non-disseminated cryptococcosis. The sensitivity and specificity of the Eiken Latex were examined using 195 sera from 25 patients with pulmonary cryptococcosis and 170 patients with non-cryptococcosis. The cutoff value of 1:8 showed a sensitivity of 76% (19/25) and a specificity of 98.9% (168/170).     

Analysis of the distribution and phosphorylation state of ZO-1 in MDCK and nonepithelial cells

We have examined the distribution and extent of phosphorylation of the tight junction-associated protein ZO-1 in the epithelial MDCK cell line, and in three cell types that do not form tight junctions: S180 (sarcoma) cells, S180 cells transfected with E-cadherin (S180L), and primary cultures of astrocytes. In shortterm calcium chelation experiments on MDCK cells, removal of extracellular calcium caused cells to pull apart. However, ZO-1 remained concentrated at the plasma membrane and no change in ZO-1 phosphorylation was observed. Maintenance of MDCK cells in low calcium medium, conditions where no tight junctions are found, resulted in altered ZO-1 distribution and lower total phosphorylation of the protein. In S180 cells, ZO-1 was diffusely distributed along the entire cell surface, with concentration of the antigen in motile regions of the cell. Cell-cell contact was not a prerequisite for ZO-1 localization at the plasma membrane in this cell type, and the phosphate content of ZO-1 was found to be lower in S180 cells relative to MDCK cells. Expression of Ecadherin in S180L cells did not alter either the distribution or phosphorylation of ZO-1. In contrast to S180 cells, ZO-1 in primary cultures of astrocytes was concentrated at sites of cell-cell contact, and the phosphorylation state was the same as that in control MDCK cells. Comparison of one-dimensional proteolytic digests of ³²P-labeled ZO-1 revealed the phosphorylation of two peptides in control MDCK cells that was absent in both MDCK cells grown in low calcium and in S180 cells.We would like to thank Cheryl Richards for her help with the cell culture and immunohistochemistry; David Begg, Gary Firestone, Vik Maraj, Manijeh Pasdar and Colin Rasmussen for helpful discussions; Jaclyn Peebles and Greg Morrison for help with graphics and photography; and Grace Martin and Bob Campenot for rat tail collagen. We are grateful to all the members of our laboratories for their friendship, advice and support. This work was supported by an Establishment Award to B.R.S. from the Alberta Heritage Foundation for Medical Research and grants to B.R.S. from the Kidney Foundation of Canada and the Medical Research Council of Canada. A.H. is funded by a Studentship from the AHFMR. K.L.S. was supported by a grant from the National Institutes of Health (DK-42799) to Gary L. Firestone. B.R.S. is a Medical Research Council of Canada and AHFMR Scholar.     

Effects of substratum morphology on cell physiology

Among the host of substratum properties that affect animal cell behavior, surface morphology has received relatively little attention. The earliest effect of surface morphology on animal cells was discovered almost a century ago when it was found that cells became oriented in response to the underlying topography. This phenomenon is now commonly known as contact guidance. From then until very recentrly, little progress has been made in understanding the role of surface morphology on cell behavior, primarily due to a lack of defined surfaces with uniform morphologies. This problem has been solved recently with the development of photolithographic techniques to prepare substrata with well defined and uniform surface morphologies. Availability of such surfaces has facilitated systematic in vitro experiments to study influence of surface morphology on diverse cell physiological aspects such as adhesion, growth, and function. For example, these studies have shown that surfaces with uniform multipls parallel grooves can enhance cell adhesion by confining cells in grooves and by mechanically interlocking them. Several independent studies have demosterated that cell shape is a major determinant of cell growth and function. Because surface morphology has been shown to modulate the extent of cell spreading and cell shape, its effects on cell growth and function appear to be mediated via this biological coupling between cell shape and function. New evidence in the cell biology literature is emerging to suggest that surface morphology could affect other cell behavioral properties such as post-translational modifications. Further elucidation of such effects will enable better designs for implant and cell culture substrata.     

Vanadium levels in urine and cystine levels in fingernails and hair of exposed and normal persons

Vanadium was determined by radiochemical neutron activation analysis (RNAA) with proven accuracy in urine of workers occupationally exposed to vanadium-rich dust in a vanadium pentoxide production plant, and values in the range of 3.02–762 ng/mL (median 33.0 ng/mL) were found. In a control group consisting of administrative workers of the plant, urinary vanadium levels were found in the range of 1.05–53.4 ng/mL (median 2.53 ng/mL), whereas in an another control group of occupationally nonexposed persons, these values amounted to 0.066–0.489 ng/mL (median 0.212 ng/mL). Accuracy of the results was tested by analysis of reference material IAEA A-13 Animal Blood and NIST SRM-1515 Apple Leaves, and very good agreement was found with literature and the NIST certified values, respectively. Unlike urine, no significant differences were found for cystine levels in fingernails and hair of exposed and control persons.     

Cell-substrate adhesion and metastatic potential of cultured mesothelioma cells induced by asbestos

Cell-substrate adhesion was quantified for two cultured mesothelioma cell lines (epitheliomatus and sarcomatous) on glass, fibronectin and laminin substrates. Interference reflection microscopy (IRM) was used to image the adhesion patterns of cells and a grey level analysis was employed to quantify adhesion. Sarcomatous cells demonstrated marked adhesion to glass and fibronectin-coated substrates but not to laminin-coated substrate, with the greatest adhesion occurring on the fibronectin-coated surface. This adhesion was accompanied by cytoplasmic spreading. By contrast, epitheliomatous cells showed little tendency to adhere to any of the substrates and only showed significant spreading when in contact with the laminin substrate (P < 0.01). A bioassay was used to determine the metastatic potential of each of the cell lines. Via the intravenous route, the sarcomatous cells killed the host rats in 24.7 ± 1.5 (S.D.) days compared to 27.3 ± 0.9 (S.D.) days for the epitheliomatous cells (P < 0.01). After subcutaneous inoculation of tumour cells, the sarcomatous cells killed the host rats in 54.7 ± 0.7 (S.D.) days compared to 48.5 ± 0.5 (S.D.) days for the epitheliomatous cells (P < 0.01). We conclude that the results of the metastasis bioassays were consistent with the predicted behavior of these cell lines based on their ability to adhere to substrates in the in vitro adhesion assays.     

The Role of Cellular and Extracellular Matrix Adhesion Proteins in Organ Transplantation

The specific adhesion of cells to other cells or to particular tissue microenvirorvments is a basic function of cell migration and recognition, and underlines many biologic processes including embryogenesis, repair and immunity. Leukocytes express an array of surface receptors broadly known as “accessory adhesion molecules.” which mediate most cell -cell interactions, direct lymphocyte traffic between anatomical compartments, and facilitate cellular adhesion to the inflammation or alloantigenic sites (Springer 1990). In addition, adhesion molecules are involved in the process of antigen recognition, and may costimulate cell activation and transformation. These proteins are thought to affect the very early antigen independent events between host leukocytes and vascular endothelium. Because of these activities, the subject of adhesion molecules is gaining interest in the field of organ transplantation, in both conceptualization and development of novel therapeutic strategies (de Sousa et al. 1991, Kupiec-Weglinski et al. 1993a, Heemann et al. 1993).     

关于吸附精制百日咳菌苗、白喉、破伤风类毒素混合制剂配方的实验报告

本文对吸附精制百白破混合制剂的不同配方进行了实验,结果表明,新一代吸附精制百白破混合制剂最佳配方为：精制百日咳菌苗１８μｇＰＮ／ｍｌ、精制白喉类毒素为３０Ｌｆ／ｍｌ、精制破伤风类毒素为１０Ｌｆ／ｍｌ。由该配方组成的吸附精制百白破混合制剂,其中百日咳菌苗的毒性试验ＢＷＤＵ／ｍｌ、ＬＰＵ／ｍｌ、ＨＳＵ／ｍｌ三种指标均符合制检规程要求。其效力单位（ＩＵ／ｍｌ）超过规程要求一倍以上,精制白喉和破伤风类毒素的安全试验均符合规程要求,白类效力试验≥８０－１００％,破类效力试验≥０．５－４．５ＩＵ／ｍｌ。上述结果说明本文提出的配方作为新一代精制百白破混合制剂的配方是适宜和实用的。     

Phagocytosis of Intravenously Administered Particles by Leukocytes Adhered to the Aortic Endothelium of the Rat

Phagocytosis has been used to characterize on a functional basis leukocytes adhered to the aortic endothelium of the rat. After intravenous administration of particles, phagocytosis was observed microscopically in esterase-positive leukocytes adhered to the endothelium in whole mounts of aorta. Polybead^R blue and red, 0.5 and 1 μm particle size, were inadequate because they were insufficiently colored to be identified individually at 400. Fluoresbrite^tm YG 0.25 and 0.50 μm at doses of 0.2 and 2 ± 0.3 m1/100 g, respectively, produced endothelial lesions. The same occurred with Monastral blue B^R (MbB) at 0.3 ml/100 g, red iron at 2 ± 16 mg/100 g and India ink at different concentrations depending on the supplier. At lower particle doses, lesions were not found. Deferoxamine mesylate 1.5 mg/100 g intravenous and allopurinol 5 mg/100 g intraperitoneal administered before the particles diminished the number and intensity of lesions. In none of the cases studied was the percentage of phagocytic cells greater than 50%. Clearance curves of MbB and Fluoresbrite^tm indicated rapid disappearance of particles from the blood. Results indicate that administration of particulate suspensions is not a good method for characterizing the phagocytic leukocytes adhering to the aortic endothelium because low doses produce rapid clearance of particles, thus impeding sufficient leukocyte loading, and higher doses produce endothelial lesions that often impair reliable counting of the adhering leukocytes.     

Partial Resistance to Heterodera avenae in Wheat Lines with the 6M v Chromosome from Aegilops ventricosa

Lines of wheat with the 6M^v chromosome from Aegilops ventricosa display partial resistance to both pathotypes Hal2 and Ha41 of Heterodera avenae. With either pathotype, the effect of this alien chromosome on cyst production, size, and fecundity was expressed in resistance tests. Partial resistance of five 6M^v(6D) substitution lines varied according to the intrinsic cyst-forming capacity of the nematode pathotypes and the recipient germplasms. Such partial resistance can be utilized in wheat breeding lines for integrated management of the cereal cyst nematode.