Biomedical subjects
Publications and source records attributed to M Simon.
We have analyzed a nuclear mutant of S. cerevisiae with no cytochrome c oxidase activity. The affected gene is that of a protein involved in the maturation process of the mitochondrial pre-messenger RNA of cytochrome oxidase subunit 1.
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.
An inferior vena cava filter made from nitinol, a thermal shape memory alloy, was evaluated. A series of in vitro experiments was designed to assess its shape recovery, orientation, and positioning after delivery and its embolus-capturing efficiency. For comparison, the Mobin-Uddin and Kimray-Greenfield filters were also tested. The results indicate that the nitinol filter is easily and accurately delivered and is superior to the other filters in its ability to capture emboli. In addition, it showed no tendency to migrate or to elevate the upstream hydrostatic pressures significantly.
Chemotactic, phagocytic and intracellular killing activities of polymorphonuclear leukocytes (PMNL) were investigated in vitro in 49 patients suffering from recurrent bouts of herpes simplex. A slight impairment of chemotactic activity and a markedly reduced capacity of killing Candida albicans blastospores were revealed. Phagocytic capacity and NADH-dependent oxidase activity of PMNL proved to be normal. The results point to an alteration of some PMNL functions in these patients.
We compared results for glycohemoglobin obtained from fresh whole blood or separated erythrocyte samples with results obtained after storage. We judged the storage condition to be acceptable ("stable") if the glycohemoglobin results after storage were within the 95 confidence interval (+/- SD) of the results obtained for the specimens on the day of venipuncture. Hemolysates can validly be stored for five months at -70 degrees C. Whole-blood samples stored at 4 degrees C remain stable for four days; whole blood treated with heparin or EDTA (but not oxalate) is stable for seven days. At 30 degrees C, whole blood or erythrocytes from some donors are stable for one day, but after two days and seven days, results are frequently higher. We confirmed previous findings that the separated erythrocytes can be stored at -20 degrees C for at least seven days. In addition, we compared the elution profiles for stored samples showing increased values.
We separated the hemoglobins in an unwashed erythrocyte hemolysate according to their isoelectric points on a thin-layer horizontal polyacrylamide gel containing ampholyte (40 g/L) over a pH gradient of 6-8. We scanned the fixed, unstained gels by microdensitometry and calculated the percentage of hemoglobin A1C. The overall CV (between-run imprecision) for a normal hemolysate (mean, 5.2% of total hemoglobin) stored at -70 degrees C was 12.6%. An above-normal pooled specimen (mean 8.5%) showed an overall CV of 8.4%. We confirmed that hemoglobins S, C, and F do not interfere; acetylated F co-migrates with A1C. The mean A1C percentage in non-diabetic adults was 4.9%, the reference interval 3.9-6.4%. The mean values for diabetics in various degrees of control were 7.6% in the group rated "good," 9.9% in the "fair" group, and 12.2% in the "poor" group. Results for patients' samples (y) were compared with results by cation-exchange chromatography (x). The slope was 1.0 and the intercept was 2.2%. The percentage of hemoglobin A1C in erythrocytes remains constant for seven days in samples stored at 30 degrees C.
This fluoroimmunoassay for digitoxin in serum involves use of a sheep antiserum to digitoxin coupled to magnetizable solid-phase particles and fluorescein-labeled 3-O-succinyl digitoxigenin as tracer. Sodium salicylate blocks binding of the drug by binding proteins, and endogenous fluorophores and other interfering components in serum samples are reliably and completely removed at the separation and wash steps, which are facilitated by magnetic sedimentation. The method is sufficiently sensitive, precise, and specific for application to routine monitoring of digitoxin therapy, and results correlate closely (r = 0.992) with those of an established radioimmunoassay.
Explore the source record for details and available documents.
One of the HEp-2 sublines maintained in the authors' laboratory was found to carry LCM virus. The virus proved to be identical with the prototype strain LCM-Am except that its multiplication rate in cell cultures and its mouse pathogenicity were limited. Forty-six cell cultures maintained in 10 Hungarian laboratories were examined for LCM carriership. Sixteen cultures including 11 HEp-2 sublines, all originating from a culture brought into Hungary in 1959, proved to carry the virus. Three FL sublines maintained in two laboratories and two sublines, viz. an RK-13 and a HeLa, maintained in a third one, were also contaminated by LCM virus. In these cases, the carrier HEp-2 subline was the probable source of infection and virus transmission is thought to have occurred in the course of manipulation with cell cultures. The necessity of introducing strict preventive measures in tissue culture laboratories is emphasized in the interest of the laboratory workers and for obtaining reliable laboratory results.
HLA-ABC antigen typing was carried out in 4 homozygous patients and 10 family members from three families with bullous epidermolysis, 7 homozygous patients and 19 family members of six families with ichthyosis, and 4 homozygous patients and 8 family members of 4 families with ectodermal dysplasia. The type of heredity was established on the basis of genetical evidence and the clinical picture. In bullous epidermolysis cases autosomal recessive heredity was detected in two families with congenital bullous epidermolysis, and autosomal heredity in two families with dystrophic bullous epidermolysis. The HLA-Aw 24, B5 combination, which was thought to be significant in epidermolysis bullosa, was found in one, B5 alone in two, out of the four families. In congenital ichthyosis autosomal recessive heredity was detected in two families out of five. In one, X-linked recessive heredity was found, and in two families X-linked recessive heredity could be supposed. In three families out of the five with congenital ichthyosis, the A2, B18 antigen combination was found. In a family where two infants died from the most severe form of ichthyosis, epidermolysis and psoriasis also occurred. In this family two grandfathers were brothers, and one of the two was a carrier of the Aw24, B5 combination. In the case of ectodermal dysplasia, in one out of four families X-linked recessive heredity, in another autosomal recessive heredity was detected. In two families X-linked recessive heredity could be supposed as only the male children were affected and also on the basis of data in the literature. The HLA-A26, B38 antigen combination occurred in three of these four families.
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.
Explore the source record for details and available documents.