Search PubMed⌕ Search

Biomedical subjects

H Wagner

Publications and source records attributed to H Wagner.

At least 667 records · Page 37Linked to original sources
PubMed1980

Intrathymic differentiation of cytotoxic T lymphocyte (CTL) precursors. I. The CTL immunocompetence of peanut agglutinin-positive (cortical) and negative (medullary) Lyt 123 thymocytes.

To analyze the developmental and functional interrelationship between cortical and medullary thymocytes, the peanut agglutinin-(PNA) binding capacity was used to separate thymocytes into PNA+ (cortical) and PNA- (medullary) thymocytes. Virtually, all positively selected PNA+ thymocytes (90% of the overall thymocyte population) expressed the Lyt 123 phenotype, whereas 90% of negatively selected PNA- thymocytes expressed Lyt 1 alloantigens, about 10% being Lyt 123 thymocytes. Provided, the requirement of Lyt 1 T helper cells was bypassed by Interleukin 2, a nonspecific mediator of T help, PNA+ Lyt 123 thymocytes mounted cytotoxic T cell responses comparable in magnitude to that of peripheral T cells. Their repertoire included antigenic disparities coded for by the complete MHC complex, H-2K, I-A, H-2D, mutational events at H-2K, as well as antigenic disparities expressed on TNP conjugated- and Sendai virus-infected syngeneic cells. PNA- Lyt 123 thymocytes represent a highly reactive pool of primary cytotoxic T lymphocyte (CTL) precursors for both alloreactive and H-2-restricted CTL responses. Since PNA- thymocytes include also Lyt 1 T helper cells, PNA- responder thymocytes are able to mount autonomously (CTL responses. Our data are first to provide direct evidence that Lyt 123 cells represent a common source of alloreactive and H-2-restricted CTL precursors in unprimed lymphocyte populations. Moreover, the apparent immunocompetence of cortical PNA+ thymocytes is now explained by their lack of T helper cells.

Agglutinins↗
PubMed1980

Induction of cytotoxic peritoneal exudate cells by T-cell immune adjuvants of the beta(1 leads to 3) glucan-type lentinan and its analogues.

Eight distinct polysaccharides (PS) of beta(1 leads to 3) glucan type were tested for their capacity to render murine peritoneal exudate cells (PEC) cytotoxic. After intraperitoneal injection of lentinan, pachymaran and HE-pachyman 3 and 4 highly cytotoxic PEC were induced. Pachyman and HE-pachyman 1 and 2 were of moderate effect, whereas CM-pachymaran and HE-pachyman 3 and 4, highly cytotoxic PEC were induced. Pachyman and HE-pachymacrophages. The induction of PEC-dependent cytotoxicity exhibited a strict dose relationship. Optimal administration of PS resulted in the induction of cytotoxicity, which persisted for more than 25 days. Surprisingly, none of the PS tested was capable of rendering normal or thioglycollate-induced PEC cytoxic under in vitro conditions. It is suggested that the capacity of PS to render in vivo macrophages cytotoxic is related to the potency of these PS to activate the alternative pathway of complement system (APC) in so far as C3b may be the essential component required to render macrophages cytotoxic.

Adjuvants, Immunologic↗
PubMed1980

Studies on the disappearance of palmitate-1-14C from the plasma of pregnant rats.

Intravenously injected radioactive fatty acids disappear from the circulation at an ever-decreasing rate; about 1% of the injected label remains in plasma for hours. This slow elimination of label can be explained by an extensive recycling of label or by a slows turnover of a portion of the injected label. The results show that a recycling of label can not be responsible for the slow elimination of label, because 1. the specific activities of the tissue fatty acids were much lower than the specific activity of the plasma free fatty acids, and 2. reinjection of the remaining label of 1% into control animals showed the same slow elimination of label. An interpretation of the experiments could be that some fatty acids (about 1%) have a dissociation rate from albumin that is much lower than others, and thus they might be responsible for the late portion of the disappearance curve.

Adipose Tissue↗
PubMed1979

Influence of somatostatin on carbohydrate absorption in human small intestine.

Oral carbohydrate tolerance tests with xylose, galactose and lactose were performed. After an interval of at least 24 h the same tests were repeated following an i.v. bolus and during infusion of somatostatin. Somatostatin does not influence xylose absorption. However, absorption of galactose and lactose is significantly reduced (p less than 0.01/0.008) during somatostatin infusion. On the other hand, serum levels of galactose remain unchanged despite administration of somatostatin, when galactose is given parenterally. The results support the assumption that the absorption process in small intestine is affected by somatostatin. Possible effects of somatostatin on hormones regulating the intestinal absorption and on energy-depending carrier mechanisms are discussed.

Adult↗
PubMed1979

Influenza virus-specific T cell-mediated cytotoxicity: integration of the virus antigen into the target cell membrane is essential for target cell formation.

This study deals with the requirements for target cell recognition by influenza A virus-specific cytotoxic T lymphocytes (CTL). H-2-identical cells were incubated with infectious or UV light-inactivated influenza A virus expressing either cleaved or uncleaved hemagglutinin (HA). Thereafter, the treated cells were tested in a 4-h 51Cr assay for susceptibility to CTL-mediated cytolysis. Regardless whether the influenza virus was infectious, virions expressing cleaved HA were efficient in target cell formation. In contrast, cells incubated with either active or UV-inactivated virions expressing uncleaved HA were not lysed by virus-specific CTL. Yet, after mere trypsin-mediated cleavage of the HA of cell-absorbed viroins, strong cytolysis could be observed. On the other hand, solubilization of the envelope lipid bilayer by ethylether abolished the capacity of the remaining HA to induce target cell formation. The results clearly suggest that mere absorption of virions to the membrane of cells, which is performed by virus with uncleaved HA, is insufficient for target cell formation. For this, both cleaved HA and an intact envelope appear to be crucial. We conclude that fusion of the virion into the cell membrane is essential for target cell formation.

Antigens, Surface↗
PubMed1979

Influence of thyroid state and improved hypoxia tolerance on noise-induced cochlea damage.

Guinea pigs were exposed to pure tone noise (2.7 kHz, 130 dB, 1 h) and cochlear microphonic potentials were measured 24 h after exposure. There is the possibility to modify the resulting noise-induced cochlea damage by regulating the function of the thyroid gland to alter the rate of metabolism. A hypofunction of the thyroid gland during sound exposure lessens, an over-function aggravates the damage. After gradual adaptation of the animals to a simulated 10,000 m altitude, the electrophysiologically demonstratable noise-induced damage was reduced. This might be explained by the greater hypoxia tolerance and perhaps additional better oxygen supply to the receptor cells.

Altitude↗