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Biomedical subjects

N Schmidt

Publications and source records attributed to N Schmidt.

At least 73 records · Page 4Linked to original sources
PubMed1989

Toxicity of metallic ions and oxides to rabbit alveolar macrophages.

The effects of soluble compounds and oxides of As, Cd, Cu, Hg, Ni, Pb, Sb, Sn, V, and Zn on oxidative metabolism and membrane integrity of rabbit alveolar macrophages were studied by 24-hr in vitro exposure. Oxidative metabolism induced by phagocytosis of opsonized zymosan was measured by H2O2 and O2- release and by chemiluminescence in the presence of luminol. Membrane integrity was estimated by extracellular LDH activity. Metallic ions and oxides inhibited the release of active oxygen species. Cd(II), As(III), and V(V) were the most toxic elements as measured by all investigated parameters. Cu(II) decreased O2- release and chemiluminescence effectively but H2O2 release and membrane integrity less. Chemiluminescence was decreased strongly by Hg(II) while O2- and H2O2 release were depressed moderately. Zn(II) and Sb(III) compounds caused medium toxicity and the tested Sn, Ni, and Pb compounds showed only faint toxic effects.

Animals↗
PubMed1989

Perceptions of South Dakota adults concerning selected adolescent health problems.

A telephone survey was conducted of a random sample of 1,015 South Dakota households to assess adults' perceptions of whether alcohol and drug abuse, teen pregnancy, and suicide attempts are problems in their community, and across the state, among seventh through twelfth grade adolescents. A majority of the respondents indicated that alcohol and drug abuse, and teen pregnancy are a problem for adolescents in their community and across the state. Regarding suicide attempts among adolescents, over a quarter of the respondents indicated that they are a problem in their community, and one half of the respondents indicated that they are a problem across the state. Alcohol and drug abuse, teen pregnancy, and suicide attempts are more likely to be reported as being a problem across the state than in the local community. Respondents overwhelmingly agreed that health education programs in schools can help prevent alcohol and drug abuse, teen pregnancy, and suicide attempts among seventh through twelfth graders.

Adolescent↗
PubMed1989

[Tissue effects of extracorporeal lithotripsy on a model of experimental biliary calculi in dogs].

Extracorporeal shock waves represent a new method to treat gallstones. This study was designed to evaluate: 1) the effectiveness of a recently available lithotripter (EDAP LT 01) for gallstone fragmentation; 2) adverse tissue reactions after treatment; 3) the optimum conditions for use of this apparatus in man. A human cholesterol stone was surgically implanted into the gallbladder of ten 20-25 kg mongrel dogs. One dog was used as a control. The other nine animals were divided into three groups (A, B and C). Two 60 min sessions of lithotripsy were carried out twice a week. Sonographic and CT examinations were performed 9 and 16 days after operation. The animals were killed 21 days after operation. Satisfactory fragmentation was obtained in 4 of the 9 animals, and in 2 dogs no stone fragments were detected. Fragments were found in the common bile duct in 5 dogs. In 2 animals a pathologic aspect of the papilla of Vater was observed. Marked hematoma was observed in the animals treated at 5 and 10 pulses/sec. In 5 cases, hematoma was observed in the gallbladder and in one case the gallbladder was ruptured. Hematoma was also noted in the hepatic vascular bed in 3 animals. Except for microscopic hemorrhagic lesions observed at the base of the right lung, no lesions were detected in any other organ. Shock waves produced by the EDAP LT 01 are effective for fragmentation of gallstones. However, in view of the tissue reactions observed at the higher pulse rates, the pulse rate should not exceed 2.5 pulses/s for use in man.

Animals↗
PubMed1989

An adrenalin rush.

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Adrenal Gland Neoplasms↗
PubMed1986

Immunochemical analysis of plasmid-encoded proteins released by enteropathogenic Yersinia sp. grown in calcium-deficient media.

Enteropathogenic Yersinia sp. releases plasmid-associated proteins of low molecular mass (26-67 kilodaltons) at 37 degrees C. In this study, the optimum conditions for the release of proteins were assessed and the released proteins (RPs) were analyzed for the manner of release, immunochemical characteristics, and the location of the genes necessary for their synthesis. Protein release was strongly enhanced when growth media were markedly depleted of calcium ions by precipitation with oxalate or chelation with EGTA [ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid]. RP yields were greatest when Yersinia spp. were in the exponential growth phase. The RPs appeared to be released from the Yersinia spp. by secretion rather than by pinching off of membrane vesicles, because the RPs did not sediment during high-speed centrifugation nor were they contaminated to any significant degree with lipopolysaccharide. Moreover, immunoblot analysis revealed only traces of protein species related to RPs within the outer membranes of plasmid-positive Yersinia spp. grown at 37 degrees C under calcium-restricted conditions. Immunoblot studies also showed that the RPs of Y. enterocolitica serotypes O:3, O:8, and O:9 and the RP of Y. pseudotuberculosis serotype I are highly cross-reactive. Finally, the immunoprecipitates of the products of minicells which harbor Yersinia plasmids were used to demonstrate that at least three proteins immunochemically related to the released fraction were plasmid encoded. These results suggest that at least three of the RPs may be related to or identical with previously described plasmid-encoded Yersinia outer membrane proteins.

Bacterial Proteins↗
PubMed1985

Synthesis of a fluorescent analogue of phosphatidylcholine.

A fluorescent analogue of phosphatidylcholine was synthesized by acylation of 1-oleoyl-sn-glycero-3-phosphocholine with 6-N-(tert-butyloxycarbonyl)aminocaproic acid anhydride employing the catalyst 4-pyrrolidinopyridine. Removal of the protective group by treatment with HCl in chloroform was followed by subsequent reaction with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) to form the fluorescent analogue of phosphatidylcholine, 1-oleoyl-2-(NBD)aminocaproyl-sn-glycero-3-phosphocholine, in good yield and with high isomeric purity.

4-Chloro-7-nitrobenzofurazan↗
PubMed1983

Hyperinsulinism after removal of a pheochromocytoma.

The finding of hypoglycemia after the surgical removal of a pheochromocytoma in two patients in a previous study led to monitoring of the serum glucose and plasma C-peptide levels in two other patients with a pheochromocytoma and one with unilateral adrenocortical hyperplasia. In the two patients with a pheochromocytoma endogenous insulin secretion, as measured by a C-peptide assay, was suppressed before removal of the tumours and resumed immediately after removal. The serum glucose levels decreased in these patients, but sufficient intravenous administration of glucose prevented postoperative hypoglycemia. In the patient with adrenocortical hyperplasia the plasma C-peptide level was not decreased before tumour removal, nor did it increase abruptly following removal. It therefore seems likely that the rapid fall in the serum glucose level following removal of a pheochromocytoma is caused by prompt resumption of beta-cell activity, with rebound hyperinsulinism.

Adrenal Cortex Diseases↗
PubMed1983

Plasmids of human strains of Yersinia enterocolitica: molecular relatedness and possible importance for pathogenesis.

One-hundred fifteen strain of Yersinia enterocolitica were examined for plasmids and plasmid-mediated pathogenic properties. Human strains of serotypes O:3 and O:9 harbored plasmids of 46 and 44 megadaltons, respectively, with 90% homology of DNA sequences. The plasmid-mediated properties were calcium dependence, survival in human serum, conjunctivitis provocation in guinea pigs, and O agglutinogens. One strains of serotype O:8 harbored a 42-megadalton plasmid with 75% sequence homology with plasmids of serotypes O:3 and O:9. An additional plasmid-mediated property was lethality for white mice. Filter hybridization of restriction endonuclease-digested plasmid DNA indicated that a 5.6-megadalton fragment of the plasmid of serotype O:8 had virtually no sequence homology with plasmid DNA of serotypes O:3 and O:9 and therefore may be associated with the lethal factor for mice.

Agglutinins↗
PubMed1982

Intravenous nitroglycerin control of blood pressure during resection of phaeochromocytoma.

The majority of patients presenting for resection of phaeochromocytoma require some form of antihypertensive therapy during operation. Phentolamine and sodium nitroprusside have both been used successfully for this purpose, but each has disadvantages. This report describes the use of intravenous nitroglycerin, a rapidly acting venodilator with no appreciable toxicity, as the sole antihypertensive agent in two patients with phaeochromocytoma and partial alpha adrenergic blockade. Hypertensive episodes were quickly and effectively controlled in each case. There were no hypotensive periods and no side effects.

Adrenal Gland Neoplasms↗
PubMed1982

Impacted common bile duct stones.

The impacted common bile duct stone can be managed either surgically or radiologically using methods such as percutaneous basket extraction or endoscopic papillotomy. At operation, if an impacted common bile duct stone cannot be removed by the usual methods, duodenotomy and sphincteroplasty are indicated. If the patient's condition is good, sphincteroplasty should not be avoided in the belief that other means of stone removal are superior. However, if the patient's condition is not ideal, sphincteroplasty should be deferred in favor of delayed removal by percutaneous or endoscopic techniques. In patients without percutaneous access to the biliary tree, endoscopic papillotomy can be effective in removing impacted stones, or at least in relieving the obstruction and allowing improvement in the patient's condition before surgical intervention is attempted.

Ampulla of Vater↗
PubMed1980

Hyperparathyroidism. A review.

Hypercalcemia with and without clinical manifestation appears to be diagnosed with increasing frequency. If hypercalcemia persists with no other obvious reasons, hyperparathyroidism can be suspected with a high degree of certainty. Surgical treatment requires confidence, patience and a thorough knowledge of the embryologic peculiarities and anatomic variations of these glands. In 88 percent of our 71 patients, a solitary benign parathyroid adenoma was diagnosed by light microscopy. Parathyroid four-gland hyperplasia was found in 5.6 percent of the patients and multiple adenoma in 3 percent. The cause of hypercalcemia was not found in 3 percent. All patients treated with parathyroidectomy responded well, with calcium levels returning to normal. Our results confirm that this conservative approach to parathyroidectomy without multiple gland biopsy is the better and more acceptable method of dealing with hyperparathyroidism. Multiple gland dissection biopsy, chest exploration and parathyroid implantation are necessary only in very difficult cases.

Adenoma↗
PubMed1978

[Long term effects of splenectomy on the immune-status of Hodgkin's disease patients depending on the modality of treatment (author's transl)].

In a total group of 103 Hodgkin's disease patients the immune-status of splenectomized and non-splenectomized individuals is compared in subgroups characterized by the modality of treatment (RT, CT, RCT). The mitogenic stimulation of peripheral lymphocytes showed a decreased response of splenectomized patients in each therapy group. The percentage, but not the absolute number/mm3, of peripheral T-cells was reduced after splenectomy. Splenectomized patients, who received combined radiation and chemotherapy showed significantly lower IgM-levels than non-splenectomized patients after the same treatment. EBV-VCA-titers and skin-test-reactivity were not influenced by splenectomy.

Hodgkin Disease↗
PubMed1978

[Hodgkin's disease: effect of spenectomy on the immune status (author's transl)].

In 22 untreated Hodgkin's patients the following parameters were studied before and after splenectomy: the total WBC, lymphocytes, B- and T-cells and mitogenic stimulation of peripheral lymphocytes using autologous and control serum. The results were correlated to patient groups with favourable and unfavourable prognosis according to pathological stage, histology, spleen involvement and constitutional symptoms. 1. All Patients. Significant increase of the absolute number of peripheral lymphocytes and B-cells. Significant increase of the spontanous DNA synthesis in the presence of AB-control serum, but no change after mitogenic stimulation of peripheral lymphocytes. No change in the number of peripheral T-cells. 2. Patients with Favourable Prognosis. Significant increase of the absolute number of peripheral lymphocytes and B-cells. Significant increase of the spontanous DNA synthesis in the presence of AB-control-serum. Significant decrease of the T-cell function (PHA- and Con-A-stimulation in the presence of autologous serum). Significant decrease of the PHA-, Con-A- and PWM stimulation rate using control serum in the lymphocytic predominance and nodular sclerosis group. No change in the number of peripheral T-cells. 3. Patients with Unfavourable Prognosis. No change in the absolute number of B-cells, of the spontanous DNA-synthesis using autologous serum and of the PHA- and Con-A-stimulation. Significant increase of the EBV-induced blastogenesis in the mixed cellularity and lymphocytic depletion group.

Adolescent↗