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Biomedical subjects

M Adler

Publications and source records attributed to M Adler.

At least 199 records · Page 11Linked to original sources
PubMed1986

Tetraethylammonium blockade of calcium-activated potassium channels in clonal anterior pituitary cells.

The effects of extracellular and intracellular tetraethylammonium (TEA) ions on single Ca2+-activated K+ channels were studied in excised membrane patches from the anterior pituitary clone AtT-20/D16-16 with the patch-clamp technique. The presence of TEA on either surface of the membrane resulted in a decrease in the single-channel current. Dissociation constants at zero voltage for the TEA-receptor complex were calculated to be 52.2 mM and 0.08 mM for external and internal TEA, respectively. The high sensitivity of AtT-20/D16-16 cells to internal TEA is of considerable interest, since in other preparations, the greater TEA sensitivity for Ca2+-activated K+ channels has thus far been found to occur on the external membrane surface. Hill plot analysis of the dose-response data yielded a slope of 0.92, indicating a one-to-one stoichiometry for TEA-receptor binding. The blockade by TEA showed little voltage or current sensitivity over the membrane potential range studied, and could be fully reversed by washout in drug-free solution. The results suggest the presence of TEA receptors on both the external and internal membrane surfaces but with different binding affinities. Occupancy of either site by TEA leads to an apparent decrease in the single-channel conductance of Ca2+-activated K+ channels.

Calcium↗
PubMed1986

Nuclear vacuolar acantholytic vesicular dermatitis associated with leukocytoclastic vasculitis.

A 48-year-old obese white woman had had a recurrent vesicular eruption for the previous 5 years. This eruption involved almost all parts of the body, including vaginal mucosa. The plantar and palmar surfaces were not involved. Eruptions start with a prodromal phase: 24 to 48 hours prior to the eruption, the normal-appearing skin becomes painful. A reddish discoloration occurs, and vesicles form within a half hour. The histologic features of the vesicles are unique in that they contain acantholytic cells. The nuclei of these cells are vacuolated and contain a reddish, "target"-appearing substance. The underlying corium shows a necrotizing leukocytoclastic vasculitis. They only effective medication for this disease is cyclophosphamide. Pathogenesis is discussed and is compared with that of other vesiculo-bullous acantholytic lesions with that of leukocytoclastic vasculitis. To the best of our knowledge, this disease appears to be unique.

Adult↗
PubMed1985

Single acetylcholine channel currents in sympathetic neurons.

Single acetylcholine (ACh) channel currents were studied by the gigaohm patch-clamp technique in cultured sympathetic neurons of the bullfrog, Rana catesbeiana. Recordings were made at 22 degrees C on cell-attached and excised membrane patches. When ACh (0.5-1 microM) was present in the pipette, a single class of inward currents was observed with a chord conductance of 30 pS and a reversal potential of -2 mV. The mean channel open time was 11.6 ms at -65 mV and showed little or no voltage-dependence over the range -85 to -45 mV. These channels appear to mediate the fast nicotinic excitatory postsynaptic current.

Acetylcholine↗
PubMed1985

[Cost-benefit studies of 2 equivalent forms of therapy in cervical cancer in the pretherapeutic T 1b stage].

Patients suffering from a collum carcinoma stage T 1b can be treated either by operation according to Wertheim and Meigs, or by radiotherapy. The results with regard to post operationem complications, five-year-survival and recidivation are equivalent in both methods. Therefore, an analysis of the indirect benefit and the costs of both therapies was performed. Surgery was superior to radiotherapy in all analysed dimensions of indirect benefit. Over and above this, expenses for an operation were 2.7 times lower than for radiotherapy.

Adult↗
PubMed1985

Hyperbaric oxygen therapy for Fournier's gangrene.

Soft-tissue infections with tissue necrosis, due to mixed aerobic and anaerobic organisms, are an accepted indication for hyperbaric oxygen (HBO) therapy. A unique type of such infection is Fournier's gangrene. This condition represents a serious risk to life and patients should be treated rapidly and aggressively. We treated three such cases by HBO. All three patients recovered from the infection, although one died later from renal and pulmonary complications.

Adult↗
PubMed1985

Massive vitamin A intoxication with ascites and pleural effusion.

Vitamin A intoxication was diagnosed in a 14-year-old girl who presented with massive exudative ascites and right pleural effusion, impaired liver enzymes, and hypertriglyceridemia. Electron microscopy of liver biopsy material demonstrated numerous perisinusoidal lipid-filled Ito cells. The patient had taken 100-200,000 I.U. vitamin A per day for 15 months. Serum vitamin A level remained elevated for 4 months after vitamin discontinuation. The unusual severity of portal hypertension was documented by a high wedged hepatic vein pressure level. The ascites occurred 2 months after vitamin A had been discontinued, probably owing to particularly slow mobilization of large hepatic stores of vitamin A. Portal hypertension disappeared after a 6-month low vitamin A diet, but the liver biopsy failed to demonstrate any decrease in number or size of Ito cells, suggesting that lipid venous obstruction is unlikely to be the only mechanism responsible for portal hypertension in vitamin A-induced liver disease.

Adolescent↗
PubMed1985

Cassava is not a goitrogen in mice.

To examine the effect of cassava on the thyroid function of mice, we fed fresh cassava root to mice and compared this diet with low iodine diet and Purina. Cassava provided a low iodine intake and increased urine thiocyanate excretion and serum thiocyanate levels. Mice on cassava lost weight. The thyroid glands of mice on cassava were not enlarged, even when normalized for body weight. The 4- and 24-hr thyroid uptakes of mice on cassava were similar to those of mice on low iodine diets. Protein-bound [125I]iodine at 24 hr was high in mice on either the cassava or low iodine diets. The thyroid iodide trap (T/M) was similar in mice on cassava and low iodine diets. When thiocyanate was added in vitro to the incubation medium, T/M was reduced in all groups of mice; under these conditions, thiocyanate caused a dose-related inhibition of T/M. The serum thyroxine (T4) and triiodothyronine (T3) concentrations of mice on cassava were reduced compared with mice on Purina diet. Thyroid T4 and T3 contents of mice on cassava were relatively low compared with mice on Purina diet. Hepatic T3 content and T4 5'-monodeiodination in liver homogenates were reduced in mice on cassava compared with other groups. The data show that cassava does not cause goiter in mice. The thiocyanate formed from ingestation of cassava is insufficient to inhibit thyroid iodide transport or organification of iodide. The cassava diet leads to rapid turnover of hormonal iodine because it is a low iodine diet. It also impairs 5'-monodeiodination of T4 which may be related to nutritional deficiency. These data in mice do not support the concept that cassava per se has goitrogenic action in man.

Animals↗
PubMed1985

Radiation effects on the external auditory canal.

Radiation is used to treat many head and neck tumors, and of necessity the temporal bone is sometimes included in the paths of radiation. We studied the histopathology of the external auditory canal in 13 temporal bones from 10 patients who had undergone irradiation for head and neck tumors. The pathologic changes noted could be divided into: bony changes, and soft tissue changes. Bony changes manifested were those of resorption, fibrosis, empty lacunae, and sequestration. There were five soft tissue changes: the formation of a secondary cholesteatoma, ulceration of the lining epithelium with resorption of the underlying bone, thickened epithelium in the canal as well as in the tympanic membrane, subepithelial fibrosis, and atrophic ceruminous glands. Clinically these changes can be manifested as a persistent otitis externa, with otorrhea and otalgia.

Adult↗
PubMed1985

Severe jaundice as presenting symptom of generalized peritonitis following cesarean section.

Jaundice complicating severe bacterial infection has already been described; much less common is its occurrence as the presenting symptom of severe sepsis. A case is presented describing a patient who developed rapid increasing jaundice on the 4th day after an elective cesarean section, accompanied by deterioration in her general status. Various diagnostic means (abdominal CT, ultrasound investigation and hepatosplenic scanning) were performed in order to confirm or rule out the possibility of intraabdominal sepsis and the only finding on physical examination, being the absence of peristaltics. In spite of negative results of all the image processing techniques the patient underwent an explorative laparotomy on the 6th day, which revealed a generalized purulent peritonitis. It should be emphasized that: Severe jaundice maybe the presenting symptom of sepsis. False negative results of several modern image processing procedures may mislead the diagnostic approach and the subsequent therapeutic methods.

Adult↗
PubMed1984

Whole gut lavage for colonoscopy--a comparison between two solutions.

The clinical efficacy and patient acceptability of a new solution containing mainly sodium sulfate and polyethylene glycol (solution II) compared with a balanced standard electrolyte solution (solution I) for whole gut lavage prior to colonoscopy were evaluated in 240 ambulatory and hospital patients randomly allocated to receive either of the two solutions. On the basis of the quality and rapidity of the bowel preparation and the good results obtained by clinical and biological parameters, we found that the newly designed solution was superior.

Colonoscopy↗
PubMed1984

Inhibitors of CDP-choline synthesis, action potential calcium channels, and stimulus-secretion coupling.

The effects of putative transmethylation inhibitors were tested on stimulus-secretion coupling and neurotransmitter secretion at synapses between neuroblastoma X glioma hybrid cells and myotubes. 5'-Deoxy-5'-isobutylthio-3-deazaadenosine or 5'-deoxy-5'-isobutylthioadenosine inhibited CDP-choline synthesis catalyzed by cholinephosphate cytidylyltransferase (CTP:cholinephosphate cytidylyltransferase, EC 2.7.7.15) and thereby decreased the rate of phosphatidylcholine synthesis from CDP-choline, but did not affect the transmethylation pathway for phosphatidylcholine synthesis. These compounds also inhibited 45Ca2+ uptake by hybrid cells mediated by voltage-sensitive Ca2+ channels, acetylcholine secretion at synapses, and signal transduction through cell membranes mediated by myotube nicotinic acetylcholine receptors. In contrast, 3-deazaadenosine or adenosine inhibited the transmethylation pathway for phosphatidylcholine synthesis, but had no effect on Ca2+ action potentials, acetylcholine secretion, or signal transduction through cell membranes mediated by nicotinic acetylcholine receptors. These results show that the stimulus-secretion coupling and secretion reactions studied are not dependent on phospholipid methylation and suggest that the activity of action potential Ca2+ channels and the rate of neurotransmitter secretion are functionally coupled to the rate of phosphatidylcholine synthesis via the CDP-choline pathway.

Acetylcholine↗