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Biomedical subjects

G Schmidt

Publications and source records attributed to G Schmidt.

At least 415 records · Page 23Linked to original sources
PubMed1985

Advanced periampullary carcinoma: endoscopic palliation by sphincterotomy.

We have described a 50-year-old woman with periampullary carcinoma with extensive infiltration of the duodenal wall arising from advanced tumor of the pancreatic head. Endoscopic sphincterotomy induced complete relief from jaundice and pruritus before definitive surgical therapy was done. This procedure should not be restricted to small tumors confined to the ampulla itself, since it may also be of palliative or preoperative value in certain patients with advanced cancer of the pancreatic head.

Adenocarcinoma↗
PubMed1985

Influence of adrenoreceptor agonists and antagonists on ovulation in the rabbit ovary perfused in vitro.

Ovaries from sexually mature virgin rabbits were dissected free on both sides and cannulated in situ via that part of the aortic segment supplying the ovarian arteries. The ovaries were mounted in a closed, recirculating perfusion system for oxygenation in vitro. Ovulation was induced by human chorionic gonadotropin (hCG) given either i.v. (100 IU) or directly into the perfusion medium (20 IU). Follicular ruptures occurred in 42 out of a total of 54 ovaries. The in vivo route of hCG administration was found to be most efficient, with ovulations occurring after a mean of 11.5 h, which corresponds well with the incidence of ovulations in situ. The prostaglandin synthesis inhibitor, indomethacin, totally abolished the hCG-induced ovulations. beta-Adrenoreceptor stimulation in vitro with terbutaline or with noradrenaline in the presence of alpha-receptor blockade with phenoxybenzamine caused a significantly increased number of gonadotropin-induced ovulations. Phentolamine or phenoxybenzamine given alone reduced the number of ruptured follicles. Noradrenaline (in the absence of hCG) and clonidine augmented the incidence of ovulation. The results indicate that local adrenoreceptor mechanisms participate in the process of ovulation, both via alpha-adrenoreceptors (probably affecting the follicular smooth musculature) and beta-adrenoreceptors (possibly through some trophic or endocrine mechanism other than a mechanical factor).

Animals↗
PubMed1985

Cloning and characterization of genes involved in production of mannose-resistant, neuraminidase-susceptible (X) fimbriae from a uropathogenic O6:K15:H31 Escherichia coli strain.

The uropathogenic Escherichia coli strain 536 (O6:K15:H31) exhibits a mannose-resistant hemagglutination phenotype (Mrh) with bovine erythrocytes and delayed Mrh with human and guinea pig erythrocytes. Neuraminidase treatment of the erythrocytes abolishes mannose resistant hemagglutination, which is typical for X fimbriae. E. coli strain 536 synthesizes two different fimbriae (Fim phenotype) protein subunits, 16.5 and 22 kilodaltons in size. In addition the strain shows mannose-sensitive hemagglutination and common type I (F1) fimbriae. The cosmid clone E. coli K-12(pANN801) and another nine independently isolated Mrh+ cosmid clones derived from a cosmid gene bank of strain 536 express the 16.5-kilodalton protein band, but not the 22-kilodalton protein, indicating an association of the Mrh+ property with the "16.5-kilodalton fimbriae." All cosmid clones were fimbriated, and they reacted with antiserum produced against Mrh+ fimbriae of the E. coli strain HB101(pANN801) and lacked mannose-sensitive hemagglutination (F1) fimbriae. From the Mrh fim cosmid DNA pANN801, several subclones coding for hemagglutination and X fimbriae were constructed. Subclones that express both hemagglutination and fimbriae and subclones that only code for the hemagglutination antigen were isolated; subclones that only produce fimbriae were not detected. By transposon Tn5 mutagenesis we demonstrated that about 6.5 kilobases of DNA is required for the Mrh+ Fim+ phenotype, and the 1.5- to 2-kilobase DNA region coding for the structural protein of the fimbriae has been mapped adjacent to the region responsible for the Mrh+ phenotype. Two different regions can thus be distinguished in the adhesion determinant, one coding for hemagglutination and the other coding for fimbria formation. Transformation of plasmid DNA from these subclones into a Mrh- Fim- mutant of E. coli 536 and into a galE (rough) strain of Salmonella typhimurium yielded transformants that expressed both hemagglutination and fimbria production.

Animals↗
PubMed1985

The electromotive force of the ventricular free wall and papillary muscle preparations.

The electromotive force of the ventricular tissues with different anatomy and activation patterns was studied. The left ventricular wall was perfused with Tyrode's solution from the circumflex branch of the left coronary artery and was stimulated first at an epicardial and then endocardial site to induce ectopic beats. The early QRS voltage was compared with the activated area at the same instant. In other experiments, the whole heart was perfused from the aorta, and the anterior papillary muscle of the right ventricle was introduced into a small separate chamber. Different locations were stimulated to induce longitudinal and transverse activation, and the remote potential was measured with leads in both directions. By means of a calibration system with artificial dipoles, the strength of the double layer was expressed in terms of mA X cm per unit area of the activation wave front. The results indicated that epicardial stimulation of the left ventricular wall produced voltage proportional to the activated area; the average moment was found to be 0.11 mA X cm per unit area. The potential curve produced by endocardial stimulation of the same preparation was characterized by an initial low-voltage phase, followed by a sharp upstroke. The right ventricular papillary muscle produced a larger double layer moment during activation in the longitudinal direction, but voltage due to transverse activation was several times smaller.

Animals↗
PubMed1985

Long term efficacy of class I antiarrhythmic agents and amiodarone in patients with malignant ventricular arrhythmias.

The long term efficacy of class I antiarrhythmic drugs and of amiodarone was investigated in 34 patients with severe organic heart disease accompanied by frequent complex ventricular arrhythmias. All patients had undergone cardiac catheterisation which included coronary angiography, and each patient underwent a short and a long term study phase. During the short term study 6 class I antiarrhythmic agents were administered orally in a randomised, single-blind fashion. The drugs investigated were disopyramide, flecainide, mexiletine, prajmalium, propafenon and tocainide. The response was judged to be effective when there was a 90% reduction of couplets and a 100% reduction of salvos. For long term treatment the patient was given one of the agents found to be effective in the short term testing. Holter monitoring was performed after 1 week, and 1, 3 and 6 months. If the drug administered initially was later found to be ineffective, the patient was given another effective class I agent. If during the short term study or the follow-up phase there was no positive response to any class I agent, the patient was given amiodarone. In 78% of the patients, one or more of the class I agents administered short term was effective. The percentage of effectively treated patients after 1 week was 56%, and was 28, 14, and 9% after 1, 3, and 6 months' treatment, respectively. In amiodarone-treated patients there was an effective response rate of 40% after 10 days, 50% after 1 month and 70% after 3 and 6 months.

Amiodarone↗
PubMed1985

[Acute pseudo-obstruction of the colon--significance of colonoscopy for diagnosis and therapy].

Acute colonic pseudoobstruction (Ogilvie's syndrome) predominantly involves elderly patients with serious underlying diseases and is defined by massive colonic distention without mechanical obstruction. Therapy of choice included surgical cecostomy with a mortality rate of over 30 percent. Fiberoptic coloscopy provides a new effective treatment modality for colonic decompression. We discuss the cases of 8 patients with Ogilvie's syndrome, who were successfully treated by colonoscopic decompression. Special guidelines for successful and safe performance of the procedure are suggested.

Acute Disease↗
PubMed1985

[Venomous spiders and their venoms].

The history of araneidism is long and confusing. The superstition seems to be inexterminatable that tropical mygalomorphs and mediterranean tarantulas are dangerous for humans. It can be looked up even in the most recent edition of the widespread clinical dictionary of Pschyrembel. In contrast to this certain ctenids, the most dangerous spiders up to now known, are mentioned not at all in medical publications. Exaggerated spider-fear is out of place because about 0.1% of all species are dangerous for man only and many of the venomous species live as hidden as they scarcely come in contact with humans.

Animals↗
PubMed1985

[Dissimilar course in the right and left ventricular function in a patient with dilated cardiomyopathy].

The case of a patient with severe dilative cardiomyopathy and cardiomegaly demonstrates that M-mode echocardiography and planar chest radiographs are not always sufficient to follow up the disease correctly. Using other non-invasive imaging modalities, in this case radionuclide ventriculography and NMR tomography, which provide more precise information with regard to morphology and function of both the right and the left heart, allows a more reliable follow-up of the disease.

Adult↗
PubMed1985

Gastric perforation secondary to metastatic bronchogenic carcinoma.

A case of gastric perforation due to a gastric metastasis of a primary bronchogenic carcinoma is presented. While ten cases of small intestinal perforation secondary to bronchogenic tumor spread were identified in the literature, there appears to be only one further report on a gastric perforation caused by bronchogenic carcinoma.

Carcinoma, Bronchogenic↗
PubMed1985

[Secondary pauses following high frequency atrial stimulation: incidence and possible underlying mechanisms].

Atrial pacing up to 250 bpm was performed in 88 patients with suspected sick sinus syndrome or syncopes of unknown origin. Measurements were done on the first five return cycles. According to cSNRTmax they were divided in 3 groups (group 1 less than 525 ms, group 2 greater than or equal to 525 ms less than 1000 ms, group 3 greater than or equal to 1000 ms). The return cycle pattern (PSM) was calculated (mean + standard deviation of PSI 1-PS15 at each pacing rate). A "normal" PSM with long PSI1 and gradual shortening of the subsequent cycles was found only at low pacing rates in group 1 and group 2. At higher rates, the PSI1 shortened and PSI2 lengthened, resulting in frequent secondary pauses (SP). Atrial pacing up to 400 bpm was performed in 20 open chest dogs. SP were frequently obtained at pacing rates above 300 bpm. Intravenous application of propranolol and atropine did not diminish SP, neither did bilateral vagotomy. Additional subthreshold stimuli, as well as stimulation with large interpolar distance did not influence the PSM of SP at high frequencies. Simultaneous stimulation of right atrium and right ventricle had no significant effects on SP. Pacemaker shifts occurring frequently after high rate pacing were not necessarily accompanied by SP. The velocity of activation spread over the sinoatrial region was significantly slower in cases of postpacing beats preceding a SP. It was concluded that the PSM of SP provoked by high rate atrial pacing is neither caused by local release of neurotransmitters nor by pacing induced changes of the autonomic tone nor by pacemaker shifts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Centrolobular liver cell necroses following occupational halothane contact. Association with antibodies to halothane altered liver cell components].

A report is given on a 24 year old nurse, who developed two episodes of fever, chills and malaise with high serum enzyme levels and histologic proof of extensive centrolobular hepatic necrosis in association with vocational halothane exposure in the operating theatre. A cause-effect relationship was suggested by the demonstration of antibodies against halothane-altered hepatocyte membrane components. Also, there was no indication of other known causes of a cytotoxic liver reaction. In certain predisposed individuals, halothane even in subanaesthetic concentrations is apparently able to induce liver cell damage. Only six further reports on such liver injuries in medical personnel could be found in the literature.

Adult↗
PubMed1985

[Heterotopic gastric mucosa of the gastrointestinal tract].

Islets of heterotopic gastric mucosa can occur in the whole alimentary tract as well as in the gallbladder, the extrahepatic bile ducts and the pancreatic tissue. In most cases they have incidentally been discovered in autopsies and surgical specimens. Ectopic gastric mucosa is known to cause gastrointestinal bleeding in Meckel's diverticulum and duplications of the intestine, and, in exceptional cases may show a malignant transformation. In endoscopy of the gastrointestinal tract ectopic gastric epithelium can often be conjectured from certain morphological phenomena. In this paper we review pathogenesis, localization, clinical significance as well as diagnostic and therapeutic aspects of heterotopic gastric mucosa.

Biopsy↗
PubMed1984

Prajmaliumbitartrate-associated liver damage. Report on seven further cases with follow-up for two to five years.

Seven further cases with n-propyl-ajmaliumbitartrate (NPAB)-associated liver damage observed between 1976 and 1980 in two collaborating institutions are reported. The cause/effect relationship could be classified as probable in three cases and as potential in the remaining four patients. No drug rechallenge was carried out. In the clinical management, definite exclusion of biliary tract obstruction had a clear priority over histologic documentation of the degree of the transient liver damage. Follow-up data after 2 years 8 months to 5 years 9 months by personal reinvestigation of three patients and by questionnaire to family physicians and patients in the remaining four cases gave no clinical or serologic indication of persisting or relapsing liver damage. Liver biopsies were not considered to be warranted in the follow-up of these asymptomatic patients with normal liver function tests.

Adult↗