Biomedical subjects

B Quade

Publications and source records attributed to B Quade.

5 recordsLinked to original sources

PubMed1993

Failure of FK 506 to suppress the T cell-mediated immunity of mice to Listeria monocytogenes.

Listeria monocytogenes belongs to the group of intracellular bacteria, which means that they reside and multiply within host cells. The protective immunity against such an infection is mediated by cellular immune mechanisms. Whereas the CD8+ T cell population plays a major role therein, the CD4+ T cells are held to be of minor importance in this defence system. Consequently, one can understand that immune suppression with FK 506 which acts primarily on this latter T cell subset, does not interfere with protective immunity of mice infected with L. monocytogenes. We have demonstrated that the drug blocks neither curing of primary infection, nor formation of granulomas, nor induction of cell populations capable of mediating adoptive transfer of immunity, nor expression of pre-existing immunity.

Animals↗

PubMed1990

[CNS involvement in neurofibromatosis. A postmortem study].

Neurofibromatosis was recorded from 30 in 82,249 postmortem cases (0.036%) at the Medical Academy of Erfurt, Institute of Pathological Anatomy, between June 1, 1945 and December 31, 1986, among them 13 cases of classical peripheral neurofibromatosis generalisata Recklinghausen (NgR) and 17 with CNS involvement. These had been 10 males and 7 females who had died at an age from 8 to 77 years (average age and death being 39 years). CNS lesions were preferentially localised in periventricular sections of the third and fourth ventricles and the cerebral aquaeduct, with diffuse gliosis being recorded from 5 cases. Typical bilateral neurofibromatosis of the acoustic nerve was established from three males aged 19, 26 and 30 years. Spinal neurinoma or neurofibroma, meningioma, an astrocytoma of the cervical spinal cord, and leptomeningeal sarcomatosis were also recorded. Additional skeletal abnormalities were exhibited by four cases. Interest is generally growing in CNS involvement in neurofibromatosis due to the possibility of intravital diagnosis by computed tomography (CT) and magnetic resonance spectroscopy (MRI) and because of possible surgical therapy. Recent studies in molecular genetics, on the other hand, have shown classical NgR to be caused by a lesion to chromosome 17, while bilateral neurofibromatosis of the acoustic nerve was found to be based on a genetic defect to the long arm of chromosome 22.

Adolescent↗

PubMed1989

Oleic acid lung injury increases plasma prostaglandin levels.

To determine whether lung injury causes increased plasma prostaglandin (PG) levels, 35 rabbits received oleic acid and 35 served as controls. Half of each group also received 4 ml/kg of Intralipid over one hour and at least five in each subgroup received indomethacin 7.5 mg/kg. Arterial and venous plasma concentrations of PGE2, 6-keto-PGF1 alpha, and PGF2 alpha-M were measured. Venous PGE2 was significantly higher in the oleic acid-injured than in the normal lung group, 1560 +/- 270 (Mean +/- SEM) versus 880 +/- 140 pg/ml (p less than .05). Plasma levels were reduced by 50% with indomethacin, but PGE2 levels remained significantly higher than in the normal lung group, 850 +/- 180 versus 480 +/- 60 for arterial (p less than .05) and 820 +/- 140 versus 480 +/- 80 for venous (p less than .05), respectively. PGF2 alpha-M levels were significantly higher in the lung injury group, 240 +/- 50 versus 50 +/- 40 pg/ml for arterial (p less than .05) and 220 +/- 50 versus 95 +/- 40 for venous (p less than .05), respectively. These lung injury-related increases in PGE2 and PGF2 alpha-M appear related both to increased pulmonary production and to decreased pulmonary clearance. With Intralipid infusion, however, arterial PGE2 increased by 500 +/- 260 pg/ml compared to baseline (p less than .05) with no change in venous PGE2, indicating in this instance that the increase in arterial PGE2 levels is related to increased pulmonary production.

Animals↗

PubMed1987

Junctions between lens cells in differentiating cultures: structure, formation, intercellular permeability, and junctional protein expression.

We previously described cultures of chick embryo lens cells which displayed a marked degree of differentiation. In this report, the junctions found between the lens fiber-like cells in the differentiated "lentoids" are characterized in several ways. Thin-section methods with electron microscopy first demonstrated that numerous, large junctions between lentoid cells accompanied the other differentiated features of these cells. Freeze-fracture techniques, including quantitative analysis, then revealed that (a) junctional particles were loosely arranged as is typical of fiber cells, (b) the population of individual junctional areas in culture was indistinguishable from that found in 10- to 12-day chick embryo lenses, and (c) apparent junction formation occurred during the development of the lens cells, with lacy arrays of particles being associated with fiber-like junctions. In addition, gap junctions with hexagonally packed particles, typical of lens epithelial cells, largely disappeared during the course of differentiation. Injection of tracer dyes into lentoid cells resulted in rapid intercellular movement of dye, consistent with functional cell-to-cell channels connecting lentoid cells. During the development of the lens cells in culture, as junction formation occurred, an increase of approximately eight-fold in MP28 protein was observed within the cells. These combined results indicate that (a) extensive lens fiber junctions and functional cell-to-cell channels are found between differentiated lentoid lentoid cells in vitro, (b) lens fiber junctions appear to form during the course of lens cell differentiation in culture, (c) a significant increase occurs in the putative junctional protein before the cultures are highly developed, (d) the increased levels of MP28 and junction formation may be required for the full expression of the differentiated state in the lens fiber cell, and (e) this culture system should prove to be valuable for additional experiments on lens junctions and for other studies requiring the development of lens fiber cells in vitro.

Animals↗

PubMedDate not supplied

Activated CD8+ T cells are involved in elimination of Candida albicans from the livers of mice.

We have investigated the course of infection of Balb/c mice with Candida albicans. After intravenous infection of mice, the yeasts were evenly distributed in the liver sections. There was a 90% reduction in the yeasts found within 7 days after infection. This reduction was accompanied by an increase in the number of phagocytic cells (Mac-1+, Gr-1+) in cellular infiltrates around the yeast cells. Furthermore, both CD4+ and CD8+ T lymphocytes were found in these pseudogranulomata, with the CD8+ cells in the periphery. Peak amounts of the cell types investigated were found at days 5 and 6 post infection, with an increased expression of receptors for interleukin 2 (IL-2R) on the surface of CD8+ cells. At day 14 of infection, the same levels as those in control mice were reached. At this time, the yeasts were virtually eliminated from the liver. By using simultaneous detection of cell surface markers and yeast cells in immunohistology, these data demonstrate the close association of fungal cells, phagocytes, TH and TC cells in pseudogranulomata during elimination of Candida albicans from the livers of mice.

Animals↗