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H Schmidt

Publications and source records attributed to H Schmidt.

At least 703 records · Page 39Linked to original sources
PubMed1988

Muscarinic receptor-mediated intracellular Ca2+ mobilization in embryonic chick heart cells.

Activation of muscarinic receptors of heart cells elevates the intracellular Ca2+ concentration. The increase is considered to be due to influx of extracellular Ca2+. We show that intracellular Ca2+ mobilization is involved. Cell suspensions prepared from hearts of 6-day-old chick embryos were loaded with the fluorescent Ca2+ chelator chlortetracycline. Muscarinic stimulation induces a dose-dependent fluorescence decrease (ED50 = 2.6 x 10(-6) M) indicating intracellular Ca2+ mobilization.

Acetylcholine↗
PubMed1988

[Giardiasis].

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Animals↗
PubMed1988

Desensitization of platelets to iloprost. Loss of specific binding sites and heterologous desensitization of adenylate cyclase.

The binding characteristics of [3H]prostacyclin and [3H]iloprost ([3H]5-[(E)-(1S,5S,6R,7R)-7-hydroxy-6-[(E)-(3S,4RS) -3-hydroxy-4-methyl-1-octen-6-inyl]-bicyclo[3.3.0]octan-3-yl idene] -pentanoic acid) and platelet adenylate cyclase activities were investigated in platelet-rich plasma preincubated with iloprost. The exposure of platelets to 0.1 microM iloprost (12 h, 20 degrees C) caused a significant loss of iloprost binding sites (P less than 0.01) without causing changes in binding affinity. This loss of specific [3H]iloprost binding was time- and dose-dependent. The reduction of iloprost receptor density was accompanied by an impaired responsiveness of platelet adenylate cyclase to iloprost, prostaglandin D2 and forskolin. In contrast, basal adenylate cyclase activity was not affected by iloprost pretreatment. The diminished response of the enzyme to GTP and NaF pointed to an involvement of the stimulatory guanyl nucleotide-binding protein (Gs) in iloprost-induced heterologous desensitization. Consequently, [32P]NAD+ and cholera toxin were used for the direct labelling of Gs. Platelet membranes desensitized to iloprost incorporated less label into the 45 kD subunit of Gs. These data suggest that the site of action of iloprost for heterologous desensitization of human platelet adenylate cyclase is located on Gs.

Adenosine Diphosphate↗
PubMed1988

[Diagnostic value of lipids and apolipoproteins for assessment of atherogenic risk].

In 242 coronarographed male patients (51.7 +/- 7.6 years) with 0-, 1-, 2- or 3-vessel diseases as well as a clinically healthy control group (n = 68, 50.6 +/- 8.5 years) the lipoprotein pattern was investigated: total-, LDL-, HDL-, HDL2-, HDL3-, beta-, pre-beta-alpha-cholesterol, triglycerides, apolipoproteins (Apo) A-I, A-II, B, (A-I)HDL, Lp(a). With regard to the separation of patients with diseases of the coronary vessels and healthy persons out of the individual parameters Apo A-I (turbidimetrically), HDL3 and HDL cholesterol had the greatest significance (maximal diagnostic efficiency: 0.81, 0.76, 0.72). For the assessment of the severity of the change of the coronary vessels the quotient total/HDL cholesterol was most suitable (efficiency: 0.67). Differences in the diagnostic significance were established in the determination of a parameter by means of different methods. The intake of beta-receptor blockers increased the concentration of the triglycerides and pre-beta-cholesterol.

Apolipoproteins↗
PubMed1988

Cellular immunological defects of chronic myelogenous leukaemics: partial dependence on busulphan therapy.

The PBMC from treated (n = 10) and untreated (n = 7) chronic phase CML patients were examined for their functional expression of helper cell-stimulating class II products, HLA-DR and -DP, and for their ability to induce suppression in normal PBMC. Although DR and DP were found to be functionally expressed in both groups of patients, a dysregulation of suppression induction was found in treated but not in untreated patients. Furthermore, the patients demonstrated a virtual absence of NK activity and severely depressed LAK activity which was equally striking in both treated and untreated patients and did not seem to be related to the presence of active suppression of cytotoxicity. Such defects in chronic phase CML patients may be relevant to the progression of their disease. Moreover, at least one of the cellular immunological defects, induction of suppressive cells, was not intrinsic to the disease, but appeared to be chemotherapy related.

Antigens, Differentiation↗
PubMed1988

Correlation between low CSA plasma concentration and severity of acute GvHD in bone marrow transplantation.

Between 1982 and 1986 51 patients were treated with ciclosporin a (CSA) to prevent graft versus host disease (GvHD) after bone marrow transplantation (BMT). Major side effects of the drug were tremor, hypertension, hepatotoxicity and nephrotoxicity. Acute GvHD 0 degree to II degree occurred in 80% of our patients, and GvHD III degree and IV degree in 20% despite the use of CSA. Two to four days before the onset of GvHD, CSA serum levels were significantly lower on the average in patients who developed GvHD III degree and IV degree compared to the others. Our data indicate that plasma CSA concentrations higher than 250 ng/ml should be achieved to reduce the severity of GvHD after BMT.

Acute Disease↗
PubMed1988

The results of short-term (6 months) high-dose testosterone treatment on bone age and adult height in boys of excessively tall stature.

Forty-nine pubertal tall boys with a mean height prediction of 203.59 cm according to the Bayley-Pinneau (BP) method were treated prospectively with 500 mg testosterone-oenanthate every 2 weeks for a period of 6 months. Before therapy chronological age (CA) was 14.14 years and bone age (BA) 13.88 years using the Greulich-Pyle (GP) method. During therapy BA advanced by 1.37 years. It continued to accelerate during the 6 months following therapy with a mean delta BA/delta CA being 3.01 at 3 months and 2.24 at 6 months after therapy. The 6 months value was only slightly less than the delta BA/delta CA of 2.47 obtained during therapy. The reduction in adult height was 7.26 cm or 50.8% of the predicted further growth in 12 boys with a long-term follow up of 2.5 years. This is similar to the 51.6% or 9.63 cm observed in 50 boys with a long-term follow up after 14.25 month treatment until a BA of 17 years or more. It is concluded that in the majority of cases high-dose testosterone therapy in boys of tall stature can be limited to a 6-month treatment period. Reassessment of the height prediction after a 6-month interval without therapy should define those patients who have to resume treatment because of their remaining excessive growth potential.

Adolescent↗
PubMed1988

Long-term development of intelligence (IQ) and EEG in 34 children with phenylketonuria treated early.

In 34 children with phenylketonuria (PKU) treated early the prognostic value of the age on institution of the diet (within the first 3 months of life) and of the quality of dietary treatment was determined in two different ways: 1) following intelligence closely (IQ) and (2) evaluating the EEG development up to their 12th (n = 34) and 15th (n = 18) years of life as appropriate. In general, IQ scores were found to be normal from the 4th-15th years of life. In our group of patients there was no effect on the IQ of the timing of diet onset. Children with "strict" dietary control showed a significantly higher IQ than those with "loose" control. One hundred and fifty-four EEGs (10/20 system, awake with eyes closed) were recorded at intervals of 2 years and conventionally evaluated. The development of alpha-activity was found to be normal. Beta-activity was enhanced. Abnormal EEG findings like general slowing and generalized paroxysmal activity (GPA) with or without spikes were more frequent in children with PKU than in controls, with the exception of focal abnormalities. EEG abnormalities increased with advancing age independently of IQ development and showed no relation to either the age at the onset nor the quality of dietary treatment.

Adolescent↗
PubMed1988

An improved procedure for background correction in autoradiography.

In the event of weak autoradiographic labelling, the proportion of truly labelled cells or structures can be calculated from the frequency distributions of grains per area or cell structure for i = 0, 1,..., n grains using the results obtained for an experimental group after the application of a radioactively labelled substance and those obtained for a control group without radioactivity. The principle of this computer-aided method is also applicable when the grain counts are related to varying areas in histological sections.

Animals↗
PubMed1988

The effect of D600 on potassium contractures of slow muscle fibres of Rana temporaria.

(1) The effect of 30 microM D600 on the amplitude and time course of isometric contractures was studied in single slow fibres of Rana temporaria. (2) D600 only slightly reduced the amplitude of contractures evoked with 30 or 95 mM K-Ringer's. Maintenance of tension was strongly impaired by D600 only during exposure to 95 mM K. The caffeine contracture was not affected. (3) Addition of 10 mM Ca2+ or other divalent cations to the medium strongly counteracted the effect of D600 on maintained tension. The order of efficiency was Ca2+ = Ni2+ greater than Co2+ greater than Mn2+ much greater than Mg2+. (4) During 2 min exposure to 95 mM K-Ringer's the slow fibres inactivated to a variable degree; recovery from inactivation in normal Ringer's proceeded with a half time of the order of 1 min, while in the presence of D600 recovery was prolonged 3.3 to 27 times. (5) It is concluded that the effect of D600 on the contractile behaviour of slow fibres from Rana temporaria is predominantly due to a prolongation of the inactivated state. It is suggested that D600 binds to a site at the outer membrane surface which also binds divalent cations and determines the degree of contractile inactivation during exposure to potassium. Blocking of Ca2+ channels is unlikely to be the mechanism of this D600-effect.

Animals↗
PubMed1988

Basal ganglion calcification in hyperphenylalaninemia due to deficiency of dihydropteridine reductase.

The disease course and therapy of a nine-and-a-half-year-old boy with hyperphenylalaninemia due to a dihydropteridine reductase deficiency are reported. Clinically, there is a marked mental retardation and complex basal ganglion symptoms. The cranial computed tomographic investigation shows bilateral, symmetrical, comma-shaped calcifications in the globus pallidus and the putamen of the lentiform nucleus. The cause of these basal ganglion calcifications remains unclear. Lowering of serum and CSF folic acid levels could not be detected, in contrast to cases with the same enzyme defect described previously.

Basal Ganglia Diseases↗
PubMed1988

Scintigraphic assessment of bowel involvement and disease activity in Crohn's disease using technetium 99m-hexamethyl propylene amine oxine as leukocyte label.

Using a novel labeling technique with technetium 99m-hexamethyl propylene amine oxine, we studied 29 patients with known or suspected Crohn's disease. Technetium 99m-hexamethyl propylene amine oxine leukocyte scanning (99mTc scan) was prospectively compared with the results of independently performed radiologic, endoscopic, and histologic examinations, and with findings at surgery, to assess the clinical usefulness of this technique to localize inflammatory lesions. In addition, uptake of technetium 99m-hexamethyl propylene amine oxine in the bowel was graded by comparing it with the uptake in liver and bone marrow and correlating this with established parameters of disease activity. The viability of homologous labeled leukocytes was greater than 95%. Less than 5% of lymphocytes were found in the final preparation. It was found that 45% +/- 12% of the label was bound to granulocytes, and 98% of the unbound label was washed off before reinjection. The results of 99mTc scan revealed a good correlation with those of barium enema (r = 0.880, p less than 0.001), of endoscopy/surgery (r = 0.983, p less than 0.001), and of all combined reference methods (r = 0.981, p less than 0.001). Activity as determined by 99mTc scan was weakly correlated with the results of Crohn's disease activity index (r = 0.559, p less than 0.01), van Hees index (r = 0.606, p less than 0.01), and erythrocyte sedimentation rate (r = 0.456, p less than 0.05) in 24 patients with proven Crohn's disease. The correlation was improved when the 99mTc scan was compared with a combination of these activity parameters and C-reactive protein (r = 0.781, p less than 0.001). Extraintestinal manifestations (joints) and complications (cholecystitis) were also identified correctly by the 99mTc scan. The study demonstrates that leukocyte scanning with technetium 99m-hexamethyl propylene amine oxine as a label can reliably assess the location and, to a lesser degree, activity of Crohn's disease. This technique is more convenient and provides images far superior to those produced by indium 111-labeled leukocyte scanning.

Adolescent↗
PubMed1988

Expression of the Ca2+ mobilizing muscarinic system in the chick embryo correlates with morphogenesis.

We describe muscarinic receptors and intracellular Ca2+ mobilization after cholinergic stimulation in cell suspensions prepared from chick embryos between day 2 (stage 12/13) and day 13 (stage 40) of development. Cell suspensions are prepared from whole chick embryos and from embryonic hearts, heads or brains, limb buds, and trunks. Muscarinic receptors are measured using [3H]quinuclidinylbenzilate as specific ligand. Intracellular Ca2+ mobilization is determined by changes of chlorotetracycline fluorescence. (1) Considerable amounts of muscarinic receptors are found in all parts of the embryo and at all stages tested. (2) The intracellular Ca2+ response after stimulation by muscarinic agonist shows a peak at day 3-4 (stage 23). (3) The pharmacological profile of the Ca2+ response remains constant during embryonic development and differs from the profiles of most adult systems. (4) The 'embryonic muscarinic system' is uniformly expressed in cells from neural and non-neural tissues. It appears and disappears independently of innervation.

Acetylcholine↗
PubMed1988

Structural alterations in the membrane of the slow muscle fiber of Rana temporaria after denervation.

Mixed fiber bundles as well as separated slow and fast fibers from normal and denervated muscles of Rana temporaria were freeze-fractured. The membranes of both fiber types are distinguished in this species by the presence of fairly regularly distributed particle aggregates or arrays of different shapes and sizes; the number per unit area of the membrane is six times higher in fast than in slow fibers. The intramembrane particle (IMP) density is higher in slow than in fast fibers. After denervation, the fast fiber membrane structure does not change whereas the slow fiber membrane acquires the characteristics of the fast fiber, i.e., an increase in the density of particle arrays and a decrease in IMP density. These changes in the slow fiber membrane are compared to the altered physiological properties of this fiber type after denervation.

Animals↗
PubMed1988

Detection of different fimbriae-like structures on the surface of Staphylococcus saprophyticus.

In relation to the ability of adhesiveness to HEp-2-cells the sizes of capsules on three strains of Staphylococcus saprophyticus were examined using an electron microscopic India ink technique. There was a good correlation between small amounts of capsular material and good adherence to the tissue culture cells. In contrast to this a very large capsule could be demonstrated on a strain which adhered only in a poor manner. Some indications of fimbriae-like structures could be confirmed by negative staining. Three different appendages: thick, short sticks, long, branched fimbriae and fine, thin filaments on the surface of S. saprophyticus were detected. The possible functions of these surface structures in the adherence process represented in a hypothetical cell model is discussed.

Bacterial Adhesion↗