Biomedical subjects
Publications and source records attributed to P Schmid.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
To dissect mechanisms that co-ordinate specific events in thymopoiesis we have characterized alterations in thymic structure and function caused by expression of a transgene. This gene encodes SV40Tag and is specifically expressed in a subset of thymic epithelial (TE) cells around birth. As a result the number of immortal TE cells increases, thymic mass increases (up to 3 g), and thymopoiesis is expanded. The latter is reflected by a approximately 100-fold increase of the major thymocyte subsets and increased peripheral T cell counts. Grossly hyperplastic thymi retain many but not all morphological features of a normal thymus. Also in grafts, SV40Tag+ TE cells steer expansion (up to 8 g) and organize a tissue with mainly cortex-like features that includes mainly SV40Tag+ TE cells, thymocytes, and macrophages. To investigate expression of specialized gene functions in the immortal TE cells, a cell line was derived. The Epi-A1 cell line expresses the genes for major histocompatibility complex class I and II, Thy-1, interleukin (IL)-6, IL-7, macrophage-colony-stimulating factor, and transforming growth factor-beta 3. Most importantly, Epi-A1 cells also express the IL-4 receptor and the c-kit ligand (KL), a factor that, in concert with commitment factors, channels progenitors into hemopoietic lineages. The expression of low constitutive levels of KL mRNA does not require IL-4, but KL mRNA levels are increased dramatically in response to IL-4. Since constitutive expression of KL mRNA in vivo is restricted to a small subset of TE cells in the thymus, our findings reveal a novel specific interaction between thymocytes and a specialized subset of TE cells.
The influence of the neuropeptide galanin, present in intrapancreatic nerve endings, on the endocrine pancreas is well known. The most potent effect of galanin is inhibition of insulin release. Little is known of its effect on the exocrine pancreas. Whether galanin plays a role in the regulation of exocrine pancreatic secretion and whether this effect is mediated directly on acinar cells or indirectly via the influence on insulin secretion is not clear. In the present study, we investigated these questions using the model of the isolated and arterially perfused rat pancreas with intact exocrine and endocrine secretion. In the presence of 15.8 mM glucose in a modified Krebs-Ringer buffer and during half-maximal stimulation of enzyme secretion with 100 pmol/ml cholecystokinin octapeptide (CCK-8), a dose-response study of 0.001-100 pmol/ml porcine galanin was performed. At concentrations of 0.001 and 0.01 pmol/ml, porcine galanin significantly stimulated insulin release (p < 0.05 and < 0.01, respectively) and also significantly enhanced CCK-8-stimulated amylase secretion (p < 0.05). Doses of 0.1 and 1 pmol/ml galanin resulted in a nonsignificant inhibition of insulin release, while 10 and 100 pmol/ml strongly inhibited the endocrine response (p < 0.001). However, concentration levels of 1-100 pmol/ml galanin did not affect CCK-8-stimulated amylase secretion. Rat galanin, tested at 0.01 and 10 pmol/ml, showed no significant difference from the effects of porcine galanin at the equipotent concentrations. It is concluded that the effect of galanin on exocrine pancreas, like the effect on endocrine functions, tends to be a direct one and that it could exert a modulatory influence on the level of neuronal transmission.
Explore the source record for details and available documents.
The rate of sensitization to isothiazolinones (Kathon CG) detected in Switzerland rose from 3.5% (out of 2,491 patients) in 1987 to 6.3% (out of 982 patients) in 1988 and 5.6% (out of 2,295 patients) in 1989-90. This rate of sensitization appears to be related to the more and more widespread use of isothiazolinone biocide in cosmetics, domestic products and in industry.
In order to determine the efficacy of Anticholest, an apple-pectin-guar soft-drink in reducing elevated cholesterol (c) levels, 33 participants (aged from 8 to 73 years) were divided into three groups of comparable age, body-mass index, total c, LDL-c, HDL-c, and triglycerides. They received this combined fiber product either (group 1) at dosages of 1 cup (17 g) every second day, or (group 2) of 1 cup a day or (group 3) of 2 cups a day. Anticholest significantly reduced total c, LDL-c and the total c/HDL-c ratio. In group 3 HDL-c was increased significantly (p less than 0.01). The average percentage decrease in total c was 10.0% for group 1, 10.7% for group 2, and 15.7% for group 3. LDL-c was lowered 14.4% in group 1, 13.8% in group 2 and 19.1% in group 3. The highest individual reduction amounted to more than 30% for total-c and LDL-c. A significant decrease was also detected in the triglycerides (tg) in group 3 (p less than 0.05). 7 patients were non-responders. Anticholest appears to be an appropriate treatment for patients at risk of coronary heart disease with insufficient or inadequate response to dietary measures, but where long-term pharmacotherapy is not yet indicated. The lack of side effects and its form of administration as a viscous drink are important determinants for long-term compliance, which is essential in the management of a chronic progressive disease such as atherosclerosis.
CASE REPORT: After uneventful induction of general anesthesia, severe hypotension and cardiac arrest developed in a 39-year-old, non-atopic man following infusion of 20% mannitol 80 min after the beginning of anesthesia. It caused a systolic blood pressure of 40 mmHg during a period of 10 min and tachycardia followed by ventricular fibrillation. Immediate resuscitation measures, i.e., external cardiac compression, rapid infusion of 3,000 ml crystalloid and 1,000 ml colloid, central-venous application of suprarenin (2.4 mg total), lidocaine (100 mg), sodium bicarbonate (100 mmol), and two defibrillations, could alleviate the life-threatening reaction. The patient recovered a few hours later without any further sequelae. ALLERGOLOGIC INVESTIGATIONS: Allergologic studies with all drugs involved revealed a positive and specific reaction in an intradermal skin test to 1:100 diluted mannitol, as did in-vitro leucocyte histamine release to 20% and 2% mannitol. For all the other drugs, skin tests and leucocyte histamine release were negative or unspecific. Available RAST determinations to thiopental and suxamethonium were also negative. The total IgE level was normal. CONCLUSIONS: Reflecting the hypotension induced by histamine, the hematocrit rose from 0.4 to 0.5 even though the patient received a large amount of fluid before and during resuscitation. This can be explained by marked sequestration of plasma in the interstitial compartment, leading to hypovolemia. The clinical course and test results suggest that mannitol was the agent responsible for the anaphylactoid reaction.
The spontaneous variability of ventricular arrhythmias was investigated in 8 patients with chronic coronary heart disease. In each patient 6 eight-hour long-term ambulatory ECG recordings were made. During the first three periods patients were without medication and during the following three periods they received a placebo b.i.d. Hour to hour variability was high in all patients. When compared with the first hour of an eight-hour period the number of ventricular premature beats (VPB) per hour in four patients declined by more than 90%, in two patients by more than 70% and in only two by less than 50%. On the other hand, increments of several hundred percent were often observed. Day to day variability of VPBs was also high. When compared with the first documented eight-hour period VPBs either decreased or increased substantially (-84% to +940%). A spontaneous reduction of VPB's for several hours may simulate an antiarrhythmic drug effect. For the group as a whole placebo had a significant effect on the number of VPBs (p less than 0.001). Beside variations of quantity, the complexity of ventricular arrhythmias (Lown classification) spontaneously changed several classes in one patient. Therefore, high spontaneous variability renders it very difficult to estimate the behaviour of ventricular arrhythmias in the individual patient with the Holter-ECG.
24 diabetics without any complications were subjected to an exercise test before and after biguanid therapy. The schedule of the physical strain was a modification of the Kaltenbach diagram. Changes of lactate, pyruvate, pH-standard bicarbonate and base excess values were analysed. Additionally to antidiabetical therapy each of the 8 patients was given either metformin or buformin or phenformin now. Each one of the biguanid derivates induced a rise of the lactate level before and after the exercise test. Phenformin showed the greatest influence on the lactate metabolism, metformin the smallest. Reasons causing the lactogene effect and the quantitative differences of the biguanides are discussed.
Explore the source record for details and available documents.
Two cases of partial trisomy 2q are described, both resulting from a balanced translocation in one of the parents. In one case the chromosomes 2 and 11 were involved [paternal karyotype: 46,XY,t(2;11)(q33;q23)]; in the second case, chromosomes 2 and 8 [paternal karyotype: 46,XY, t(2;8(q32;p23)]. When the two patients were compared to the few cases reported in the literature, it was concluded that the associated clinical syndrome is characterized by severe psychomotor retardation and relatively mild abnormalities involving skull and facies.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Further evidence of parallel evolution of Necrolemur and Microchoerus is put forward. The two forms were found in a fissure filling of Upper Eocene age (Fons 4) from Dielsdorf (Zürich region, Switzerland). Not only the dentition shows different morphs, but also postcranial material represents two vertical clingers and leapers of different size.
The influence of centrophenoxin (meclofenoxate) administration in a high daily dosage of 3 grams has been investigated in 10 persons with a mean age of 64 throughout 12 months. The mean age of the control group was 59. The function of bone marrow and a number of indicators of renal and hepatic function has shown no harmful changes after this long term treatment with an extremely high daily dosage. To investigate a possible influence on aging we chose the oral glucose tolerance test, a test battery for pulmonary function and the maximum oxygen consumption capacity. A highly significant (2P smaller than 0,335) influence of the drug for increasing the maximum oxygen input has been found. The hypothesis is presented, that this effect is due to an increase in cardiac functional capacity. Furthermore a significant decrease in fasting glucose levels has been found, while the glucose concentration one and two hours after administration of 100 grams of oral glucose have shown no significant changes. Body weight revealed a small but significant decrease. Side effects: we found a mild gastric pain in 4 patients that disappeared after 20 minutes. 5 Patients complained of a very small increase in jitteriness.
Explore the source record for details and available documents.