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Biomedical subjects

H Wagner

Publications and source records attributed to H Wagner.

At least 703 records · Page 39Linked to original sources

[Effect of saralasin on plasma renin activity and arginine-vasopressin in patients with angiotensin-dependent hypertension (author's transl)].

A central stimulatory effect of angiotensin II (AII) on the secretion of arginine-vasopressin (AVP) has been described. The competitive blocker of AII, saralasin (SAR) has been used for diagnostic purposes in angiotensin-dependent hypertension. In addition SAR has a partially agnoistic effect. The aim of the present study was to demonstrate whether AVP-levels can be influenced during SAR-induced renin stimulation. In 9 patients with essential hypertension blood pressure dropped significantly under SAR (10 microgram/kg/min over a 30 min period). Before and after SAR plasma renin activity (PRA) and AVP were measured by RIA, SAR evoked significantly increments of PRA in all patients and of AVP in 6 patients. The increased serum concentrations of AVP following SAR may be explained either by the depressor effect of SAR, its diminished concentration at the central receptor, or a partial AII-agonistic effect.

Adolescent↗

[Correlations between metabolisms of magnesium, calcium and parathormon (author's transl)].

Serum- or plasma levels of 102 healthy individuals as well as 78 patients with chronic renal insufficiency of various degrees were tested for parathormon (PTH), calcium, magnesium, anorganic phosphate, alkaline phosphatase, kreatinin, total protein as well as magnesium concentrations of the erythrocytes; attempts were made to correlate these parameters with each other. As most important finding in healthy individuals a significant negative correlation could be observed between serum PTH and magnesium of erythrocytes, whereas patients with renal insufficiency had a marked elevation and significant positive correlation between these two parameters. Since all other correlations were not as striking, if compared to these findings, we concluded that a feedback regulation system may exist in the intracellular magnesium concentration and PTH metabolism, so that an increase of the intracellular magnesium stimulates the PTH secretion, whereas elevated PTH activity causes a decrease of the intracellular magnesium together with a depression of the PTH release.

Alkaline Phosphatase↗

[On the ACTH-corticoid relation in essential hypertension in dependence of plasma-renin activity (PRA) (author's transl)].

Patients with essential hypertension were studied for the reaction of the hypophyseal-adrenal-system before and during insulin hypoglycemia test. We found in our results that the mean total corticoid levels in plasma of hypertensive patients with low or high PRA are significantly higher than control levels. In insulin hypoglycemia test the mean corticoid levels of patients with normal and high PRA do not differ from the mean levels found in normal individuals whereas hypertensive patients with low PRA have significant lower plasma corticoid levels. The mean baseline and hypoglycemia induced plasma ACTH levels of each group of hypertensive patients are higher than those of the controls. Patients with high PRA show the highest rise of mean plasma ACTH levels during hypoglycemia. These data suggest that the adrenal system of hypertensive patients produces less total corticoids; plasma ACTH levels of these patients therefore are higher than those of normal individuals.

Adolescent↗

[High-performance liquid chromatographic separation and quantitative determination of valepotriates in valeriana drugs and preparations (author's transl)].

It is possible directly to separate and analyse, quantitatively and qualitatively, the valepotriates from Valeriana crude extracts or from commercial Valeriana preparations by high-performance liquid chromatography. The separations are achieved on 4 or 8 mm I.D. columns packed with silica gel (particle size 10 micron) with n-hexane-ethyl acetate mixtures as eluent. A refractive index detection system is necessary for determining all of the valepotriates. If the concentration differences between didrovaltratum and valtratum are very great, an ultraviolet (UV) detector must be used and the determination must be conducted in two steps. For valtratum drugs UV detection alone will suffice. As internal standards p-dimethylaminobenzaldehyde should be used for extracts and preparations from valtratum races, and benzaldehyde in the presence of didrovaltratum races. This determination is superior to the combined thin-layer chromatographic-hydroxamic acid method used hitherto with respect to time consumption, precision, and sensitivity.

Cyclopentanes↗

T-cell-mediated cytotoxic immune responses to F9 teratocarcinoma cells: cytolytic effector T cells lyse H-2-negative F9 cells and syngeneic spermatogonia.

Murine thymus derived (T) lymphocytes primed in vivo to mouse 129 (H-2bc) derived H-2-negative F9 embryonal carcinoma cells and rechallenged in vitro with X-irradiated F9 stimulator cells differentiated into anti-F9 cell immune cytotoxic T lymphocytes (CTL). Using CBA mouse derived splenic responder T cells, F9 stimulator cells triggered a primary cytotoxic anti-F9 response. The CTL generated lysed the F9 antigen-positive target cells F9. PCC3 and PCC4, but not the F9 antigen-negative mouse 129 derived PYS tumor cells, nor LPS induced H-2bc blast cells. Mouse 129 anti-F9 cell antisera but not H-2k anti-H-2bc antisera blocked the lytic interaction with F9 target cells. Similarily unlabeled F9 cells but not H-2bc blast cells inhibited the anti-F9 cell cytotoxicity H-2k anti-F9 cell immune CTL were found to be cytotoxic for syngeneic spermatogonia, known to express the F9 antigen. The results suggest not only that CTL can recognize and lyse H-2-negative target cells, but also that CTL precursors can be sensitized against H-2-negative stimulator cells. From the data available it may be inferred that anti-F9 Cell immune CTL recognize the F9 antigen, known to be linked with the T/t locus. Since anti-F9 cell immune CTL lyse syngeneic spermatogonia, the system may be useful to analyze in vitro the induction and effector phase of a T-cell-mediated cytotoxic autoimmune orchitis.

Animals↗

H-2-linked murine cytotoxic T cell responses specific for sendai virus-infected cells.

CBA (H-2k) mouse-derived lymphochoriomeningitis virus and herpes simplex virus-specific cytotoxic T lymphocytes lyse virus-infected target cells compatible on either the H-2k or H-2D region. In contrast, CBA, C3H and AKR (H-2k) mouse-derived sendai virus-specific cytotoxic T lymphocytes (CTL) fail to lyse H-2D-compatible virus-infected cells. A similar lack of H-2D region-associated lytic activity was found with C57BL/6 and C57BL/10 (H-2b) mice as well as with the recombinants B10.A (2R) [Kb-Db] and B10.A (4R) [Kk-Db]. On the other hand, BALB/c (H-2d) mice and A/J (H-2a) mice do generate H-2Dd-associated sendai virus-specific CTL. These results are in contrast to those obtained with (CBA X BALB/c)F1 and B10.HTT [Ks-Dd] mice, which failed to mount Dd region-associated CTL responses. It is concluded that D region-associated sendai virus-specific CTL responsiveness varies with the H-2 genotype of the responder cells.

Animals↗

Transmitter mediated arginine vasopressin release from superfused hypothalamus and pituitary gland.

The study was designed to investigate the effect of various neurotransmitters on the hypothalamus and pituitary gland to determine the sites of their action. Superfused isolated rat hypothalami and pituitary glands demonstrated basal secretion of arginine vasopressin (AVP) and repeated response to stimulation thus showing the viability of the preparation. Acetylcholine and histamine stimulated the release of AVP at the hypothalamic and pituitary levels; dopamine and norepinephrine released AVP in a dose related manner only from the hypothalamus; angiotensin II released AVP in the same fashion only from the pituitary gland. AVP secretion stimulated by dopamine and norepinephrine may represent synaptic inputs which are localized at the hypothalamus and must be distinguished from the site of action at the pituitary gland of angiotensin II.

Acetylcholine↗

[Multiple cavernous haemangiomas of the colon (author's transl)].

Extensive involvement of the colon with cavernous haemangioma is described in a 26-year old man. Clinically the disease manifests itself by recurrent rectal bleeding and abdominal distension, leading to his admission. Double contrast examination of the colon showed involvement of the ascending, transverse and descending colon, the sigmoid and the rectum. Arteriography demonstrated vascular tumours in the territory of the jejunal artery, the left colic artery and the superior rectal artery. This is a rare condition which has been described only 53 times in the literature (1, 3, 5, 7). The diagnostic value of double contrast examination of the colon and of selective angiography for differential diagnosis is stressed.

Adult↗

Effect of dihydroergotoxine on cyclic-AMP-generating systems in rat cerebral cortex slices.

In slices of rat cerebral cortex, cyclic-AMP formation is stimulated in response to added noradrenaline (NA), isoproterenol (ISP) or adenosine. The effect of ISP could be antagonized only by the selective beta-adrenoceptor-blocking agent pindolol, whereas the stimulating effect of NA could be antagonized by both alpha- and beta-adrenoceptor-blocking agents. Dihydroergotoxine (DHET) at low concentrations (10(-8)M) antagonized the stimulating effect of NA but not of ISP or adenosine, suggesting that this substance has a high affinity for central alpha-adrenoceptors. We could also show that DHET is accumulated in rat cerebral cortex after repeated oral application. In slices of cortex obtained from rats after treatment with DHET for 3 and 6 weeks, but not after 1 week, NA had a significant lower effect on cyclic-AMP formation than in slices from corresponding controls.

Adenosine↗

Effects of saralasin on blood pressure, renin and renal blood flow in unilateral renovascular hypertension.

The effect of saralasin, a competitive inhibitor of angiotensin II, was assessed in hypertensive patients with unilateral renal artery stenosis after furosemide application. A significant fall of systemic arterial blood pressure, an increase of renal venous renin activity, significantly on the stenosed side in patients without arteriosclerosis of the contralateral kidney, and an almost equal decrement of renal blood flow in both kidneys were observed. Conceivably saralasin exerts different sodium-dependent effects on peripheral angiotensin II and specific intrarenal vascular receptors.

Angiotensin II↗