Biomedical subjects
Publications and source records attributed to G Koch.
Proteins of Toxoplasma lysate were separated by SDS-polyacrylamide gel electrophoresis with subsequent transfer to a nitrocellulose sheet by electrophoretic blotting. The range of protein bands was 6-100 kD. Monoclonal antibodies 1B2, 5B10, 4F6 reacted with antigens of 21 kD, 35 kD and 66 kD. Monoclonal antibodies reacted with major antigens of the RH-tachyzoiten surface and HanR-cysts.
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In 10 healthy men aged 25 to 35 years the variability of basal arterial blood flow (BBF), maximal arterial blood flow (MBF) as induced by a 5-minute arterial occlusion, total venous capacity (TVC) and venous emptying rate (VER) were studied in both the upper and lower limbs by repeated measurements over 5 hours under strictly standardised conditions using an automatic venous occlusion plethysmograph. Mean values obtained at the initial examination in the forearm and calf respectively were: BBF: 3.7 +/- 1.2 and 2.3 +/- 0.6, MBF: 24.2 +/- 6.5 and 28.0 +/- 8.9, VER: 64.0 +/- 14.0 and 66.0 +/- 16.4 ml/min per 100 g tissue, TVC: 3.5 +/- 0.9 and 3.7 +/- 0.8 ml per 100 g tissue. At 45 min there was a general trend towards lower values in particular regarding BBF and TVC. Reproducibility in terms of coefficients of variation computed from duplicate determinations were 25% and 13% for BBF and 11% and 7% for MBF measurement in the forearm and calf respectively and below 10% for TVC and VER. The low reproducibility of BBF measurement is apparently due to a high degree of random biological variability in particular concerning the forearm vascular bed which makes the forearm poorly suitable for studying effects of interventions in cardiovascular control.
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Human recombinant interleukin 1 alpha (IL-1 alpha) and IL-1 beta inhibited the replication of the mammary tumor cell line, MDA-MB-415; stimulated division in the colon carcinoma, SW-48; and had no effect on the growth of the milk mammary line, HBL-100. Inhibition of growth was reflected in a significant decrease in DNA synthesis accompanying a transient increase in RNA synthesis. Specific binding of 125I-labeled recombinant IL-1 beta by MDA-MB-415 and SW-48 reached a maximum by 2 h of incubation, and an equivalent amount was bound by each cell type. Binding was inhibited in a dose-dependent manner by unlabeled IL-1 alpha or IL-1 beta. Scatchard plot analysis revealed that MDA-MB-415 cells expressed approximately 700 binding sites with an apparent dissociation constant of 8.8 x 10(-10) M. Reversibility of growth inhibition was independent of dose or time of incubation, but DNA synthesis did not return to control values. Flow cytometric analysis of DNA content showed that growth inhibition was cell cycle phase nonspecific with a slight reduction in the proportion of cells in S phase. The major conclusion from these studies was that inhibition or stimulation of malignant cell growth by IL-1 was related to the presence of receptor sites.
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Evidence suggests that endogenous opioids, particularly the beta-endorphins and met-enkephalins, are closely involved in stress-induced analgesia and nociceptive pain control. Numerous investigations have been conducted to evaluate the role of opioids in silent vs symptomatic myocardial disease. There is good evidence to suggest that patients with asymptomatic ischemia have defective pain perception compared with those with angina; however, the precise role of the endorphin and enkephalin systems in this phenomenon remains to be elucidated. Possible sources for disparate study results include variation in patient populations, insensitive or improperly timed assay techniques, and differences in amount of ischemia.
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Nine patients with metastatic breast cancer received 30 x 10(6) I.U. of Interferon - Betaser (Betaseron) intravenously daily times five for two consecutive weeks followed by a two week rest period. Only one patient received more than one such cycle of Betaseron. The drug was well tolerated in eight of these patients. One patient, with liver metastases and liver dysfunction, developed hepatic decompensation during therapy. Toxicity consisted of anorexia, chills, fever, fatigue and nausea with an occasional patient having emesis. One patient developed severe thrombocytopenia, two, significant leukopenia and nine, mild elevations of serum transaminase. Two patients developed beta interferon binding antibodies but none developed neutralizing antibodies. No anti-tumor responses were seen and disease progression occurred rapidly during the four week cycle in eight of nine patients.
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This investigation examined the reproducibility of resting and post exercise plasma beta-endorphin levels. Twenty subjects (10 men and 10 women) had their resting endorphin levels measured under controlled conditions on four separate occasions. Concomitantly, the endorphin response of eight trained runners completing three similar ten mile runs was also determined. For the resting data, there was no significant overall variation among trials, but the intra-subject variability was substantial; the within subject variance was 6.16, and it corresponded to an intra-class reliability coefficient of r = 0.239. No gender effect was noted for the average beta-endorphin values for the four occasions (men = 4.6 +/- 1.7; women = 4.4 +/- 2.1 pM/l); however, the males' within-subject variance of 8.548 (r = 0.080) was significantly larger than that of 3.719 (r = 0.485) for females. Of the runners, one outlier subject had a uniquely high average beta endorphin level of 85.67. Analysis including and excluding the outlier subject yielded within-subject variances of 29.61 (r = 0.960) and 34.47 (r = 0.176), respectively; variances for differences in confidence limits for random variation, they must exceed 7 pM/l at rest, 17 pM/l post exercise, and 20 pM/L difference from rest to post exercise.
The characteristics of monoclonal antibody CVI-ChNL-68.1, which specifically reacts with a group of chicken non-lymphoid cells, are described. Both tissue distribution shown on cryostat sections using immuno-enzyme histochemistry, and quantitative data obtained on cell suspensions are presented. Functional characteristics of CVI-ChNL-68.1-positive cells, such as antigen uptake and glass adherence, are determined. Results show that CVI-ChNL-68.1 reacts with monocytes, macrophages, and interdigitating cells. Possible relationships between the various non-lymphoid cells are discussed.
Using immunohistochemistry, the distribution and characteristics of cells detected by the newly developed monoclonals HIS-CI (B lymphocytes), HIS-C7 (leucocytes), HIS-C12 (IgM), CVI-ChIgM-59.7 (IgM), CVI-ChIgG-47.3 (IgG), and CVI-ChIgA-46.5 (IgA) are described in bone marrow, thymus, bursa of Fabricius, and spleen of chickens of different ages. Furthermore, quantification of cells positive with the described monoclonal antibodies was performed on cytocentrifuge preparations. The specificities of the monoclonal antibodies are discussed.
A method for the extraction of human beta-casomorphin-8 immunoreactive material from human plasma and a radioimmunoassay for its determination in the plasma extracts were developed. Blood was collected from 34 men, from 35 non-pregnant women, from 35 pregnant women and from 138 women after delivery and plasma extracts were assayed for the presence of human beta-casomorphin-8 immunoreactive materials. No human beta-casomorphin-8 immunoreactive material was detected in the plasma of men or non-pregnant women, whereas such material was found in the plasma of 26 out of 35 pregnant women and in the plasma of 100 out of 138 women after parturition. Material collected from women after delivery was characterized by gel filtration and high-performance liquid chromatography (HPLC) and was found to be of different composition in various individuals; its components, one of which coeluted with human beta-casein from the HPLC column, have apparently higher molecular weights than human beta-casomorphin-8. Some of these compounds seem to be very stable against enzymatic degradation at 37 degrees C in human plasma, whereas human beta-casomorphin-8 proved to be degraded very fast under identical conditions. A physiological significance of mammary products of the beta-casomorphin type during pregnancy or after parturition is suggested.
Acute exposure to carbon monoxide has the potential to impair exercise capacity in patients with ischemic heart disease. The effect of sufficient inhalation of this compound to gradually produce a level of 6% carboxyhemoglobin was studied in 30 nonsmoking patients with obstructive coronary artery disease and evidence of exercise-induced ischemia. After an initial training session, subjects were exposed to air or carbon monoxide on successive days in a randomized double-blind crossover fashion. Cardiac function and exercise capacity were assessed during symptom-limited supine radionuclide ventriculography. On the carbon monoxide day, mean postexposure carboxyhemoglobin was 5.9 +/- 0.1% compared with 1.6 +/- 0.1% (p less than 0.01) after air exposure. The mean duration of exercise was significantly longer after air compared with carbon monoxide exposure (626 +/- 50 s for air versus 585 +/- 49 s for carbon monoxide, p less than 0.05). Actuarial methods suggested that subjects were likely to experience angina earlier during exercise on the day of carbon monoxide exposure (p less than 0.05). Both the level (62 +/- 2.4 versus 60 +/- 2.4%, p = 0.05) and change in left ventricular ejection fraction at submaximal exercise (1.6 +/- 1.6 versus -1.2 +/- 1.6%, p = 0.05) were greater on the air exposure day compared with the carbon monoxide day. The peak exercise left ventricular ejection fraction was not different for the two exposures (57 +/- 2.5% for both). These results demonstrate earlier onset of ventricular dysfunction, angina and poorer exercise performance in patients with ischemic heart disease after acute carbon monoxide exposure sufficient to increase blood carboxyhemoglobin to 6%.
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