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Biomedical subjects

H Wagner

Publications and source records attributed to H Wagner.

At least 775 records · Page 43Linked to original sources

Inhibition of stress ulcer formation with somatostatin in rats.

Prophylactitc effect of somatostatin (Growth hormone inhibiting hormone) on restraint stress ulcer formation was studied in rats. Rats treated with somatostatin before and during stress had only the fifth part of the ulcers of the untreated animals after 9 hours of immobilisation. Pathophysiologic mechanism for stress ulcer production is as well discussed as the prohibiting effect of somatostatin on ulcer formation. Prophylactic clinical use has to be considered.

Animals↗

Sodium- and potassium-activated adenosine triphosphatase of the nasal salt gland of the duck (Anas platyrhynchos). Purification, characterization, and NH2-terminal amino acid sequence of the phosphorylating polypeptide.

Sodium- and potassium-activated adenosine triphosphatase (NaK-ATPase) was purified from nasal salt glands of the duck (Anas platyrhynchos). Enzyme of specific activity 2,000 to 2,300 mumol of Pi/mg/hour was routinely obtained by sodium dodecyl sulfate treatment of a microsomal fraction of gland homogenate in the presence of 3 mM ATP followed by pelleting of the enzyme through a sucrose density gradient. Purified NaK-ATPase was stable for over 3 months at -20 degree. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography purified NaK-ATPase was shown to contain two polypeptide chains of molecular weight 94,000 and 60,000, the smaller of which was a glycoprotein. Purified enzyme of activity 2,300 mumol of Pi/mg/hour bound 3,600 pmol of ouabain/mg of enzyme protein. Reaction with [gamma-32P]ATP in the presence of Mg2+ and Na+ gave 7,025 pmol of acyl phosphate/mg of enzyme protein. The turnover number calculated from phosphorylation data was 5,460 min-1. Amino acid analysis of the polypeptide components of duck salt gland enzyme after separation by gel filtration chromatography in sodium dodecyl sulfate demonstrated strong compositional homology with highly purified NaK-ATPase preparations from other organs and species. The NH2-terminal amino acid of the 94,000-dalton component was glycine and of the 60,000-dalton component, alanine. With a combination of manual sequencing and automated Edman degradation, the NH2-terminal amino acid sequence of the 94,00-dalton catalytic subunit was found to be Gly-Arg-Asn-Lys-Tyr-Glu-Thr-Thr-Ala-()-Ser-Glu.

Adenosine Triphosphatases↗

Virus and trinitrophenol hapten-specific T-cell-mediated cytotoxicity against H-2 incompatible target cells.

Immune spleen cells from LCM virus-infected (CBA X C57BL/6)F1 radiation chimeras entirely repopulated with CBA-T6 lymphocytes were cytotoxic for allogeneic, LCM virus infected C57BL/6 mouse-derived target cells. Normal C57BL/6 targets were not lysed. CBA-T6 lymphocytes derived from (CBA X C57BL/6) radiation chimeras sensitized in vitro against TNP-conjugated C57BL/6 spleen cells lysed TNP-conjugated C57BL/6 targets. However normal C57BL/6 mouse-derived targets were not destroyed. The magnitude of virus-specific (or TNP-specific) cytotoxic responses against H-2 incompatible targets was lower compared to that against H-2 compatible targets. These data are considered to support and to extend the altered self concept, but are not consistent with the dual recognition concept.

Animals↗

Secondary cytotoxic allograft responses in vitro. II. Differentiation of memory T cells into cytotoxic T lymphocytes in the absence of cell proliferation.

Murine cytotoxic T lymphocytes (CTL) were induced in "one-way" mixed lymphocyte cultures and their physical characteristics investigated by velocity sedimentation at 1 X g. The in vitro differentiation of progenitors of CTL into primary and secondary CTL was paralleled by characteristic changes in the size of the responder cells. Fractionated cells enriched for primary blast CTL reverted into clonally restricted "nonlytic" secondary T lymphocytes. Upon antigenic reexposure, these lymphocytes differentiated into secondary CTL within 18-32 h. This took place in the absence of cell proliferation and could be triggered by UV light irradiated allogeneic stimulator cells. It is suggested the different characteristics for the induction of either a primary or secondary cytotoxic T cell response reflect qualitative differences between unprimed T cells and memory T lymphocytes.

Animals↗

Shared determinants between virus-infected and trinitrophenyl-conjugated H-2-identical target cells detected in cell-mediated lympholysis.

Infection of H-2-identical mice with either lymphocytic choriomeningitis (LCM) virus, vaccinia virus, or paramyxo (Sendai) virus resulted in the generation of specifically sensitized cytotoxic T lymphocytes (CTL). CTL generated in vitro against 2,4,6-trinitrophenyl (TNP)-conjugated syngeneic stimulator cells were specifically cytotoxic for TNP-conjugated H-2K (D) region identical targets. Both LCM and vaccinia-induced CTL, however, were found to be strongly cytotoxic towards TNP-conjugated, H-2K(D) region-identical target cells. In contrast, Sendai virus-induced CTL did not lyse TNP-conjugated, syngeneic target cells. Inhibition experiments using cold targets suggested that shared antigenic determinants can be detected on either LCM virus-infected and TNP-conjugated targets, which are not present on the cell surface of normal target cells.

Animals↗

In vivo sensitization of T cells to hapten-conjugated syngeneic structures of major histocompatibility complex. I. Effect of in vitro culture upon generation of cytotoxic T lymphocytes.

Murine T cells were sensitized in vitro towards fluorescein isothiocyanate (FITC)-conjugated syngeneic spleen cells. The lytic activity of the effector cells generated was restricted to FITC-conjugated, H-2-compatible target cells. 2,4,6-Trinitrophenyl (TNP)-conjugated syngeneic targets were not lysed. A method is described for the in vivo sensitization of murine T cells towards TNP (or FITC)-conjugated syngeneic spleen cells. The procedure is based on the observation that a local graft of hapten-conjugated syngeneic spleen cells results in the development of sensitized prekiller T cells within the draining lymph node (LN). By mere in vitro incubation of such LN cells immunological specific anti-TNP (or anti-FITC)-reactive cytotoxic T lymphocytes (CTL) are generated. The in vitro differentiation of CTL requires 48-72 h; it is dependent on cell proliferation and is abolished by treatment of the LN cells with mitomycin C. Thus there is a separation between the sensitization of CTL precursors (which effectively takes place in vivo) and the phase of cell differentiation into CTL (which effectively takes place only in vitro). Similar to in vitro-sensitized CTL, the specificity of in vivo-sensitized CTL is dictated by the hapten used for the induction of the immune response and is restricted to hapten-conjugated syngeneic target cells.

Animals↗

Enhanced in vitro immunogenicity of H-2 antigens in the presence of la antigens.

In a primary and secondary MLC the in vitro immunogenicity of allogeneic PHA induced blast cells (which lack i region coded determinants) was compared to that of LPS imduced blast cells. Unlike LPS induced blast lymphocytes (stimulator cells) which induced high cytotoxic activity, PHA induced blast cells were found to be poor stimulator cells in a primary MLC. Yet in a secondary MLC both types of stimulator cells induced cytotoxic activity equally well. Using one type of responder cells the relative immunogenicity of various stimulator cells incompatible on either the H-2K and H-2D region or on the i region, or on the complete H-2 complex, was compared. The magnitude of cytotoxic response induced in a strain combination differing at the complete H-2 complex exceeded by far the sum of separate responses obtained against the H-2D region, H-2K region and the i region coded determinants respectively. These results suggest that the presence of i region coded determinants on allogeneic stimulator cells enhance the in vitro immunogenicity of H-2K and H-2D region coded transplanatation antigens.

Animals↗

[Investigation of the dalcon shield by scanning and transmission electronmicroscopy and bacteriologic studies (author's transl)].

Bacteriologic studies and ultrastructural examination (scanning and transmission electron microscopy) was performed on twenty eight Dalcon Shields and the corresponding uteri. Microbiologic organism were detected in various degree. The results were compared with clinical results especially in regard to septicaemia in patients carrying the device.

Bacteriological Techniques↗

Secondary cytotoxic allograft responses in vitro. III. The immunogenicity of allogeneic membrane fragments.

The immunogenicity of murine membrane fragments was tested both in primary and in secondary in vitro cytotoxic allograft responses, and compared to that of intact allogeneic stimulator cells. Allogeneic membrane fragments induced poor proliferative and cytotoxic responses in normal splenic responder cells. However reexposure of immune responder T cells to allogeneic membrane fragments triggered the generation of highly reactive cytotoxic T lymphocytes (CTL). Moreover, the generation of secondary CTL as induced by allogeneic membrane fragments was preceded by only a marginal cell proliferation. The results obtained are compatible with the concept that serologically defined (SD) antigens alone are capable of triggering alloimmune T cells to differentiate highly reactive secondary CTL.

Animals↗

Cell-mediated immunity to H-2 antigens. Characteristics of the effector cells as detected in the microcytotoxicity assay.

Cell-mediated immune reactivity against murine histocompatibility antigens was compared by using both the microcytotoxicity assay (MCA) and the 51 chromium release assay (CRA). In both assay systems the data obtained showed T cell-mediated reactivity. In the CRA only T lymphocytes were detectable, which were cytotoxic, In contrast, in the MCA reactivity of nonlytic secondary T cells (NLST) was also detected. NLST acquired their MCA-reactivity within the first 24 hr of the 48-hr test period of the MCA. Circumstantial evidence is provided suggesting that MCA reactivity is a product of two different processes, namely, antigen-specific restimulation of immunt T cells and shedding of cytotoxicity inhibiting factors.

Animals↗

Aneurysm of the membranous ventricular septum. Surgical consideration and experience in 29 cases.

Twnety-nine cases of aneurysm of the membranous septum in association with various cardiac abnormalities are described. These aneurysms are more common than has been previously thought (10% of the total associated anomalies managed surgically). The patients' ages ranged from 3 months to 28 years. All of the 29 patients were divided into three groups. Group I consisted of 15 patients with ventricular septal defect (VSD), 5 of whom had associated artrial septal defect (ASD). Group II consisted of 5 patients with VSD and pulmonic obstruction, and Group III comprised 9 patients with transposition of the great arteries (TGA). Complete correction was performed in all the patients, and the aneurysm was imbricated in the suture line of the VSD in all cases but one. There was only one hospital death, the result of subpulmonic obstruction. This occurred in the first patient of this series, who had aneurysm of the membranous septum in TGA and VSD and in whom the aneurysm was not suspected preoperatively and was overlooked at surgery. There were no late deaths. In 5 patients a small residual VSD and in 3 patients a small recurrent aneurysm were found in a postoperative study. When these accompanying aneurysms are encountered during surgery or are previously diagnosed, resection or imbrication of the sac should be accomplished in order to prevent further enlargement or postoperative arrhythmias and, especially in TGA, to avoid fatal subpulmonic obstruction as occurred in our only death. According to the present data, in the presence of an aneurysm, even a small VSD should be closed by a patch and the aneurysm should perhaps be excised.

Adolescent↗