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Biomedical subjects

J Hausman

Publications and source records attributed to J Hausman.

6 recordsLinked to original sources

The role of calcitonin gene-related peptide in the mouse thymus revisited.

Calcitonin gene-related peptide has been identified by immunocytochemistry within the thymus of fetal through aged adult mice. Calcitonin gene-related peptide positive nerves are observed from embryonic day 17 throughout the lifespan of the mouse. A sparse cell population positive for CGRP is first observed during the late embryonic period at the corticomedullary boundary and the medulla, and it becomes more densely distributed in this region in the adult. In the thymus of the aged mouse the number of CGRP-positive cells diminishes. Pharmacologic studies demonstrated that fresh thymocytes display a receptor Kd for CGRP of 1.17 +/- 0.06 x 10(-10)M and a Bmax of 12.7 +/- 4.7 fmol/mg protein. Functional studies indicate that CGRP is a potent inhibitor of mitogen and antigen-stimulated proliferation of T cells and that it inhibits IL-2 production in cloned splenic T cells. Recent studies suggest that endogenous CGRP may serve as a natural inhibitor of inappropriate induction of mature, antigen-sensitive cells in the thymus as well as play a role in thymocyte education. These findings are discussed in terms of the distribution of CGRP cells and nerve terminals within the thymus and their relationship to positive and negative selection of the T-cell repertoire.

Animals

Calcitonin gene-related peptide in the developing and aging thymus. An immunocytochemical study.

Calcitonin gene-related peptide (CGRP) is known to block Con A and PHA induced T cell proliferation. As a first step in determining the role of this peptide in T cell education and function we have studied the distribution of CGRP within the developing mouse thymus using immunocytochemistry. CGRP-like immunoreactivity (CGRP-IR) was found in the thymic nerves in close proximity to blood vessels in the 17-day-old embryonic mouse thymus. A discrete population of small cells at the cortico-medullary junction also stained intensely for CGRP. As the mouse thymus reached maturity (three to eight weeks) CGRP innervation became more dense, with fibers running along the vasculature at the cortico-medullary boundary, then branching into the cortical and medullary regions. Some fibers were invested in the blood vessels while a large portion formed varicosities among the cells of the thymus. In the mature thymus, the small CGRP-IR cortico-medullary cells were more numerous, and CGRP-IR was also found in subcapsular and trabecular mast cells. The pattern of innervation remained the same in the aging mouse thymus (six months), but there appeared to be somewhat fewer cortico-medullary cells and an increase in mast cell number. In the aged (eighteen months) thymus, the small CGRP-IR cortico-medullary cells were rarely seen, but mast cells were more numerous, most of which stained positively for CGRP, in the connective tissue. Nerves containing CGRP-IR generally had the same distribution as in the younger mice but appeared somewhat truncated. The distribution of CGRP-IR nerves in the mouse thymus at different stages of development was similar to that reported for cholinergic (AChE-positive) nerves. Since the brain-stem vagal nuclei have been shown by retrograde transport studies to project to the thymus as well as to contain CGRP-IR neurons, our findings suggest that CGRP-IR thymic nerves may be derived from the vagus complex.

Aging

[The effect of chronic exposure to lead on lysosomal levels in amniotic fluid in an experimental model].

Groups of female rats were exposed for prolonged periods to different lead concentrations in drinking water; in one group was also added to the drinking water, in the amniotic fluid of exposed females greatly reduced lysozyme values were found, as compared with controls. Concurrent Zn administration considerably reduced the effect of lead. Long-term exposure to low concentrations of lead caused a greater drop of lysozyme levels in amniotic fluid than that found in previous experiments after short-term exposure to higher lead concentration.

Amniotic Fluid

New age nursing.

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Curriculum

[Study of CNV in patients with chronic respiratory insufficiency (author's transl)].

Chronic respiratory insufficiency (CRI) has physiological and psychological aspects that we have tried to examine with the CNV. The study is related to the CNV of 15 CRI patients and 14 control subjects (Cir.). The duration and amplitude of the CNV are more developed in CRI patients. The latter show an increased frequency of prolonged CNV and also a predominance of negative phenomena during the post-imperative period of the CNV. 'Delayed CNV' are very rare among CRI patients, but they are present among 60% of Ctr. subjects. The 'field dependency CNV' are not more frequent in either group. Various factors, most likely related to those CNV modifications, are discussed (aetiologies, chronicity, adaptation, personality).

Adult