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Biomedical subjects

W Engelhardt

Publications and source records attributed to W Engelhardt.

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

[Central venous catheterization with an incorporated J-wire and contamination protective sleeves for rapid venous catheterization of the external jugular vein].

The external jugular vein can easily be identified in most patients and provides an alternative access to the superior vena cava. Unfortunately, advancement of the catheter may be hampered for anatomical reasons, e.g. the presence of valves. Use of a flexible guide-wire with curved tip (J-wire), as first proposed by Blitt et al., results in a significant increase in the rate of successful cannulations. This method necessitates tedious surgical draping, however, that may not always be practicable. Therefore, a catheter was developed that is wrapped in a protective sleeve and contains a J-wire instead of the common plastic mandrin, thus making contamination during insertion impossible.

Catheterization, Central Venous↗
PubMed1988

Open comparative study with treatment-refractory depressed patients: electroconvulsive therapy--anesthetic therapy with isoflurane (preliminary report).

Isoflurane is the only routine volatile anesthetic which leads to a burst-suppression EEG in nontoxic concentrations and for which no memory impairments can be expected subsequent to anesthesia. After electrically induced spike-wave activity in electroconvulsive therapy (ECT), a brief period of a very flat EEG can be observed. This phenomenon may be closely related to the therapeutic effects of ECT. The results which have been achieved up to now in comparing ECT to anesthetic therapy with isoflurane, without seizures being induced, are presented.

Adult↗
PubMed1988

[The course of myocarditis in childhood].

Seventeen patients, aged from 2 days to 16 1/2 years, all suffering from acute myocarditis, were observed between 1975 and 1987. At the onset of the acute infection all patients had a severe disfunction of the left ventricle. Two patients died after hospital admission. Death occurred after one day and after five days, respectively. Postmortem examination showed inflammatory reaction within the myocardium with cellular infiltrates in both cases, and a variable degree of myocardial necrosis in one. The remaining 15 patients had follow-up check-ups between 2 months and 8.25 years later. Electrocardiographic abnormalities disappeared within 3 month in all patients, and the reduced fractional shortening of the left ventricle became normal in 80% of the patients after 5.5 months. At the last follow-ups one patient showed dilated cardiomyopathy. The other patients showed complete recovery regarding their functional capacity and regarding other clinical findings even though 50% still had some minor abnormalities in the echocardiogram and on the chest x-ray. Based on the findings of this follow-up investigation, the prognosis of acute myocarditis in childhood seems as being favourable, although some residual myocardial damage may occur. In most cases this residual myocardial damage is clinically and functionally insignificant. However, in some rare cases, significant chronic myocardial damage will be found.

Acute Disease↗
PubMed1987

Characterization and structural analysis of Fc gamma receptors of human monocytes, a monoblast cell line (U937) and a myeloblast cell line (HL-60) by a monoclonal antibody.

A monoclonal antibody, FR51, raised against the IgG Fc receptor (Fc gamma R) of the human monoblast cell line U937 was used to analyze the distribution of this antigen on various human cells. This antibody inhibited the binding of human IgG to the Fc gamma R on U937 cells, HL-60 cells and human peripheral blood monocytes. In contrast, the Fc gamma R on human granulocytes (neutrophil cells) and on an Epstein-Barr virus-transformed human lymphoblastoid cell line (Raji) were not recognized, indicated by the failure of blocking the binding of human IgG ligand to the Fc gamma R on these cells. By affinity chromatography of detergent-containing cell free lysates of surface-iodinated U937 cells, HL-60 cells and monocytes, a protein of 70-kDa was isolated. This protein was identified as the Fc gamma R by rebinding the isolated protein to immobilized human IgG. Removal of the carbohydrate moiety with endo-beta-N-acetylglucosaminidase F demonstrated that the receptors consist of a 40-kDa polypeptide. Analysis of the polypeptide patterns obtained by proteolytic digestion of either mature (70-kDa) or deglycosylated (40-kDa) receptors isolated from monocytes, U937 cells and HL-60 cells strongly suggests that the Fc gamma R are identical. The monoclonal antibody FR51 specifically reacts with Fc gamma R on human monocytes, a myeloblast and a monoblast cell line but not with the receptors on a B cell line and neutrophil cells.

Antibodies, Monoclonal↗
PubMed1987

[Cervix cytology and primary malignancies of the gastrointestinal tract].

During the cancer check-up of a 46-year-old woman a PAP V was diagnosed in the cervical scrapings. The atypical cells of the abrasion specimens from the corpus uteri arouse strong suspicion of malignancy. Connected with the clinical data, this finding primarily indicated a metastatic involvement of the inner genitals. This suspicion was confirmed by exploratory surgery laparotomy. A large tumor was found intraoperatively which was occupying the entire stomach. Concurrently, a diffuse peritoneal carcinomatosis was found with involvement of the left adnexae in the sense of a Krukenberg's tumor.

Adenocarcinoma↗
PubMed1987

[Is halothane obsolete? An illustration of measurement with two standards].

In 1986 the discussion on the further use of halothane broke out anew, especially after the Bristol symposium and the European Congress of Anesthesiology in Vienna. Everywhere there is great uncertainty on whether or not halothane should continue to be used. A critical analysis of the literature shows that there are two standards applied to halothane. When judged by the same stringent criteria as halothane other anesthetic techniques are also dubious, e.g. neuroleptanesthesia or epidural block. Finally, experience with isoflurane, the strongest rival of halothane, is not adequate to warrant abandoning halothane, especially as long as the question of coronary steal is still open. At present there is no solid scientific basis for vanishing halothane.

Anesthesia, General↗
PubMed1987

[Sector echocardiographic determination of the diameter of the large arteries of the heart in children].

We determined the end-diastolic and end-systolic diameters of the aortic root, ascending aorta, aortic arch, pulmonary trunk, and right pulmonary artery in infants and children with congenital heart disease by means of two-dimensional echocardiography. These measurements were compared to those obtained by angiocardiography in the same patients. We found an excellent correlation (r = 0.94 to 0.99) with a slope near to 1. In a second study, we measured echocardiographically the end-systolic diameters of the aortic root, ascending aorta, aortic arch, pulmonary trunk and right pulmonary artery in 87 healthy newborns, infants, children and adolescents and correlated these measurements with the body weight. We found a nonlinear correlation with the diameters being best described as a function of the natural logarithm of the body weight. We determined normal ranges containing 90% of all future normal observations with a confidence of 90%. These normal ranges may serve as basis for comparison of measurements of the same diameters in children with heart disease.

Adolescent↗
PubMed1986

Fc gamma-receptor-mediated changes in the plasma membrane potential induce prostaglandin release from human fibroblasts.

Binding of aggregated human immunoglobulin G (IgG) on diploid human fibroblasts leads to a rapid depolarization of the cells within 1-2 min. We resolved this membrane potential change into its plasma membrane and mitochondrial membrane components by measuring the transmembrane distribution of the lipophilic tritium-labelled cation tetraphenylphosphonium, [3H]Ph4P+. The responsibility of the plasma membrane for the membrane potential change, induced by binding of IgGs, is demonstrated. The IgG-induced membrane depolarization leads to the induction of prostaglandin E2 synthesis. Aggregated immunoglobulins (IgG) are specifically bound via the Fc portion because only binding of Fc fragments, in contrast to (Fab')2 fragments, leads to a stimulation of prostaglandin E2 synthesis comparable to that mediated by IgGs. Depolarization of the plasma membrane by short incubation of the fibroblasts in high-K+ buffer (5 min) results in a stimulation of prostaglandin E2 synthesis comparable to that mediated by either aggregated human IgGs or Fc fragments. Our previous results on Fc gamma-receptor-mediated antigen-IgG-antibody complex internalization showed that a maximum uptake of these complexes could be detected 60-90 min after binding. Therefore, we conclude that not internalisation but binding of aggregated IgGs to the Fc gamma receptors on human fibroblasts is the stimulus for plasma membrane depolarization leading to an enhanced prostaglandin E2 release.

Antigen-Antibody Complex↗
PubMed1986

[Diagnosis of pleural effusion using sector sonography in childhood].

Sectorsonographic examination was performed in 17 patients with pleural effusion after heart surgery (n = 15) and during bacterial pneumonia (n = 2). When pleural effusion could be diagnosed by chest roentgenogram, it was identified by ultrasound in every patient. On the other hand, it was possible to recognize pleural effusion by ultrasound in 6 patients in whom chest roentgenogram was equivocal or failed the diagnosis. Neither chest roentgenogram nor ultrasound allowed the differentiation between transsudate, exsudate, chylus, and blood in the pleural space. However, localization and mobility of the diaphragm as well as concomitant pericardial effusion and/or ascites can be identified by ultrasound. Sonographic examination, an easily repeatable harmless method without radiation exposure should be performed in pediatric patients whenever pleural effusion is suspected.

Ascites↗
PubMed1986

[Dose-response relationship and serum concentrations of methohexital and hydroxymethohexital following rectal anesthesia induction with 1% and 5% methohexital solutions in children].

Dose-response-curves for rectal induction of anaesthesia in children with 1%- or 5%-methohexitone-solutions and dosages of 5, 10, 15, 20 and 25 mg/kg body wt. were obtained in 10 groups of 20 children. Methohexitone and hydroxy-methohexitone serum-levels were compared in another 23 children after application of 1%- or 5%-methohexitone-solutions at dosages of 15 and 20 mg/kg body wt. The sleep induction quota after 1%-methohexitone-solution in the 20 and 25 mg/kg body wt.-dosages was significantly higher, 20% and 25% respectively, and the mean sleep induction time shorter, 37% and 45% respectively compared with results after 5%. The change after 15 mg/kg body wt. was not significant. A study of dosages 5 and 10 mg/kg body wt. was discontinued due to insufficient effect. Methohexitone serum-levels ranged from 0.7-8 mg/l. All of the children after the use of 1%-methohexitone-solution, and only 60% after 5%-methohexitone had serum concentrations above the sleep inducing "borderline" concentration of 2 mg/l. The differences between mean methohexitone and hydroxy-methohexitone-serum-levels were not significant due to the small groups and the wide range of results. We conclude that individual dosages of 15 or 20 mg/kg body wt. 1%-methohexitone-solution should be applied according to clinical criteria such as physical and psychic status of the child.

Anesthesia, Rectal↗
PubMed1985

The adrenal medulla protects against stress ulcers in the presence of gastric sympathectomy.

Surgical splanchnicectomy protects against stress ulcers in the presence of an intact adrenal medulla. The additional removal of adrenal medullary catecholamines results in an augmentation of gastric lesions. Inhibition of gastric acid secretion, improved gastric mucosal blood flow, enhanced gastric oxygen extraction, and increased energy supply to gastric tissue are discussed as possible protective mechanisms.

Adrenal Medulla↗
PubMed1985

Biology of metastasizing ameloblastoma.

The present report of a malignant metastasizing ameloblastoma and a critical review of literature was undertaken in an attempt to better understand the biological potential and behavior of this rare tumor and thus to facilitate its clinical management. Most of the 26 patients with a proven malignant ameloblastoma including the present case had developed multiple recurrences. The lung was the most frequent metastatic site (88%) followed by regional lymph nodes (27%). Furthermore metastases were observed in some cases in the bone, brain, kidney, small intestine and liver. The interval between diagnosis of tumor and manifestation of metastases was long with a median of 11.1 years. The average survival time was 13.1 years. By contrast, the interval between diagnosis of metastatic disease and death was relatively short (median: 2.6 years). The histologic and cytologic pattern of malignant ameloblastoma and of its metastases was not significantly different from that of non-metastatic ameloblastoma. Because of the lack of morphological criteria of malignancy the biological behavior of ameloblastomas cannot be predicted. It is difficult to be certain which factors are important in the delayed induction of metastases. It is suspected that ameloblastomas possess an inherent low grade malignancy which is stimulated by multiple recurrences. It is further assumed that the metastatic tumor cells have a slow growth rate resulting in late clinical manifestation of metastases. When lung metastases occur we recommend their surgical removal in order to prolong live expectancy or even to obtain a curative effect.

Adult↗
PubMed1985

Influence of pancreatic duct occlusion on islet hormones in peripheral and portal plasma and in the pancreas of the mini-pig.

In a total of 18 'Göttingen' mini-pigs we studied basal glucose in the peripheral plasma, and the hormones insulin, glucagon, and somatostatin in the peripheral and portal plasma, as well as in extracts of pancreatic tissue, both in animals subjected to pancreatic duct occlusion with prolamine (Occ pigs) 9 months previously and in controls. Additionally, in the pancreas the relative frequency of A-, B-, D- and PP-cells was determined by immunocytochemistry. In peripheral blood of Occ pigs glucose, insulin, and somatostatin were unchanged, while glucagon was decreased. Also after occlusion the portal plasma revealed an increase in insulin but unchanged glucagon and somatostatin, while in the pancreatic tissue insulin and glucagon were statistically unchanged, but somatostatin was reduced. The relative frequency of A-, B-, D- and PP-cells in the pancreatic islets was comparable in both control and Occ pigs. It is concluded that also in the pig pancreatic duct occlusion leads to atrophy of the exocrine pancreas, but leaves undisturbed basal blood glucose, insulin, glucagon and islet cells.

Amylases↗
PubMed1984

Basal plasma somatostatin in biliary stone patients.

We have searched for elevated basal plasma somatostatin in patients with documented cholelithiasis (n = 37) and compared the data with healthy control subjects (n = 27). Using an acidic assay system for measuring somatostatin in unprocessed plasma, we could not find deviations from normal values in biliary stone patients. Also basal blood levels of other islet cell hormones (insulin, glucagon) and minerals (calcium, magnesium) are unchanged. Further studies are needed to find out whether an abnormal response of plasma somatostatin to appropriate stimuli can play a role in the etiology of biliary stones.

Adult↗
PubMed1984

Pancreatic duct occlusion in the rat - short-term effects on oral glucose tolerance and short- and long-term effects on hormone content of the pancreas.

In a short-term (14 days) and a long-term (84 days) experiment after pancreatic duct occlusion in the rat, we measured the insulin, glucagon and somatostatin content of the pancreas; in the short-term experiment, in addition, we performed an oral glucose tolerance test on the 14th day. Exocrine pancreatic function in the short-term study was monitored on the 9th day - in the long-term study on the 21st day. In the long-term study, the pancreatic organ was also examined histologically. Occlusion of the pancreatic duct considerably reduces exocrine function. This accords with the histologically observed atrophy of the exocrine parenchyma, above all in the body and tail (after 84 days). 14 days after occlusion, basal plasma glucose and insulin was about the same as in the sham-operated rats. Incremental insulin after the glucose load in occluded rats was delayed for about 30 min, but the pattern of plasma glucose was only insignificantly altered as compared with the sham-operated controls. The insulin content of the pancreas on days 14 and 84 after occlusion was increased, glucagon and somatostatin unchanged. We conclude, that (a) intraductal occlusion of the pancreas is a suitable tool for inducing an atrophy of the exocrine pancreas; (b) in the short-term, after the duct occlusion, oral glucose tolerance is preserved, but the passage of insulin into the blood is delayed and is associated with a high level of insulin in the pancreas; the cause or causes of this coincidence is/are unknown.

Animals↗
PubMed1984

Effect of the uroprotector sodium 2-mercaptoethane sulfonate (Mesna) on the proliferation of the bladder urothelium in the rat after administration of cyclophosphamide.

The chemotherapy of malignant tumors with oxazaphosphorine cytostatics, e.g., cyclophosphamide (CP) and ifosfamide, is limited by their severe urotoxic side effects. As a result of cytotoxic damage, the proliferation of the urinary bladder urothelium is considerably stimulated during an intensive reparative regeneration. The recently developed uroprotector sodium 2-mercaptoethane sulfonate (Mesna) allows regional detoxification limited to the kidneys and lower urinary tract and thus protects against damage by aggressive oxazaphosphorine metabolites. The object of the present quantitative autoradiographic investigation was to study urothelial proliferation in the bladder of rats after administration of CP alone and in combination with Mesna. 20 h after intraperitoneal injection of a single dose of CP alone (100 mg/kg), the urothelium showed a steep rise of the 3H-thymidine (3H-TdR) labeling index which reached a peak of 17.6% at 30 h. Thereafter, the 3H-TdR index rapidly dropped. A second peak of 4.4% was observed after 7 days. With supplementary intravenous administration of a single dose of Mesna (100 mg/kg) 15 min before treatment with CP, the labeling index was substantially lower than after administration of CP alone. Thus, maximal values of only 1.6 and 1.9% were observed at 35 h and 7 days, respectively. Histopathological examination of the bladders showed severe necrotizing and ulcerative cystitis, 10, 20 and 25 h after administration of CP alone whereas with additional treatment with Mesna only slight edema of the lamina propria developed. The results obtained clearly demonstrate the protective action of Mesna on the urothelium of the lower urinary tract against the urotoxic effects of CP.

Animals↗