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Biomedical subjects

J Matousek

Publications and source records attributed to J Matousek.

At least 55 records · Page 3Linked to original sources
PubMed1985

Experimental elimination of various intestinal segments by means of devascularization (devitalization).

Segments of the small and large intestine, of varying lengths (10-180 cm), were devascularized by simultaneously ligating the mesenteric arteries and veins. When the circulation had been cut off, the ends of the devascularized segment were both ligated, continuity of intestinal passage was renewed by forming an anastomosis and the isolated segment was left in situ, together with its contents. Contrary to accepted views, no changes leading to death (necrosis and peritonitis) occurred, but the devascularized tissue was progressively destroyed and reconstructed until, after four weeks, all that was left was a minute fibrous residue. None of 41 pigs died as a result of devascularization, including those in which large doses of pathogenic microorganisms were injected into the isolated segment. The possibility of employing this technique in the surgical treatment of inoperable tumours is discussed.

Animals↗
PubMed1983

Immunosuppressive effects of bovine seminal fluid fractions with ribonuclease activity.

Using different isolation procedures (after acidification and saturation with 3 M ammonium sulphate) three fractions were isolated from bull seminal vesicle fluid and assayed for their effects on cell immunity in vitro and in vivo. Two of these preparations (ZS RNase and AS RNase) possessing a high level of ribonuclease activity at concentrations of 50 micrograms/ml showed inhibitory effects (up to 80%) on 3H-thymidine incorporation into the DNA of mitogen-or antigen-stimulated human lymphocytes. The third preparation (3M-P) possessing low ribonuclease activity showed lesser inhibitory effects. The potency of mouse spleen cells to cause regional GVH reaction was significantly decreased after preincubation of spleen cells to cause of 1 mg per AS RNase or ZS RNase whereas 3M-P was ineffective in this test. A single dose of 1 mg per mouse of ZS RNase or 3M-P administered i.p. on day 4 after skin transplantation significantly prolonged graft rejection. Both preparations at this dose potentiated the effect of cyclophosphamide on skin graft survival. All tested preparations preincubated with mouse bone marrow cells had no adverse effects on their colony-forming activity (in the spleens of irradiated mice). The possibility of utilizing the preparations with ribonuclease activity isolated from vesicle fluid in clinical bone marrow transplantation is discussed.

Animals↗
PubMed1983

Complete ischaemia of the normal mouse, rat and rabbit testes and of mouse testes with SAI sarcoma.

After complete ischaemia of mouse, rat and rabbit left testes produced by ligating the funiculus spermaticus, a diminution and degenerative changes occurred in the testes following a temporary swelling. Degenerative changes were associated, in addition to necrosis of all cells in the testes, with an infiltration of leucocytes, mainly polymorphonuclear and mononuclear cells, and lymphocytes from the neighbourhood of the testis through the tunica albuginea into the surface parts of testicular tissue. The cells enumerated above migrated gradually from the periphery to the centre of the testis. First, they colonized the interstitial tissue and then perturbed the membrana propria of the seminiferous tubules and got inside the tubules. In the majority of animals, the appearance of connective tissue with collagen fibres was noted behind the zone of leucocytes and lymphocytes while the testis was shrinking. Ischaemic testes disappeared completely within 6 to 10 weeks after devitalization in most of the mice. Antibody production in the course of the degenerative process in the ischaemic testes was not demonstrated by indirect immunofluorescence nor was it detectable by spermagglutination test in rabbits, and the skin tests in rats and rabbits were also negative. The contralateral, non-ischaemic testes were not damaged in any of the examined males as shown by histological analysis. A similar degenerative process occurred in most of the testes of mice in which syngeneic SAI sarcoma cells grew and were implanted intracutaneously on the back of mice of the same inbred strain. Upon intraperitoneal inoculation of tumour cells the growth of ascites tumour appeared 5 to 8 weeks after implantation of the tumorous testis in about 30% of the mice, 70% of mice were resistant. Ascites tumours were demonstrated in control animals without previous tumour implantation and deaths were recorded in 95% of mice.

Animals↗
PubMed1981

Inhibitory effect of bovine seminal ribonuclease on activated lymphocyte and lymphoblastoid cell lines in vitro.

The native dimer bovine seminal ribonuclease, AS RNase, and its four modified derivatives (carboxymethylated, succinylated, oxidated and reduced) were examined for their effects on PHA- or PWM-stimulated human lymphocytes, mixed lymphocyte cultures and lymphoblastoid cell line line (Molt-3, RAJI, UHKT-2 and UHKT-5). Among all substances tested the native AS RNase exerted the strongest suppressive effect on PHA-, PWM-, and MLR- stimulated lymphocytes. At concentrations of 5 and 100 microgram/ml AS RNase inhibited lymphocyte stimulation in MLR by 40 and 95%. The carboxymethylated and reduced derivatives possessed inhibitory effect one order lower, while the succinylated derivative showed a negligible effect, and the oxidated derivative was ineffective. The inhibitory effect on PHA-stimulated lymphocytes was not reduced when AS RNase was added to lymphocyte culture 24 or 48 h later. Likewise, the 20-fold increase in PHA concentration did not cause any decrease in inhibitory effect of AS RNase. AS RNase added to transformed lymphocytes simultaneously with 3H-TdR did not affect the thymidine uptake. As RNase also had the strongest inhibitory effect on growth, viability and the DNA synthesis in all lymphoblastoid cell lines tested. After 72 h cultivation with AS RNase at a concentration of 100 microgram/ml, the DNA synthesis decreased by more than 90% in Molt-3 and UHKT-2 cells. Simultaneously reduction in cell count and increased numbers of dead cells compared to control cultures were found. Carboxymethylated derivative at the same concentration inhibited thymidine incorporation into the DNA by 70% but did not cause any cytotoxic effect. Other derivatives showed negligible or null effects. These results are in agreement with some data published earlier, that the dimer of seminal ribonuclease exerts a significant antitumour effect. The immunosuppressive effects of AS RNase observed in the present paper suggest that this compound is one of the components of seminal plasma which may take part in suppression of immune responses of the female reproductive tract to spermatozoa.

Animals↗
PubMed1981

The effect of bull seminal ribonuclease on reproductive organs and sexual behaviour in male rats.

Wistar male rats received an intratesticular injection (at 114 and 265 days of age) of 3 mg of partially purified bull seminal ribonuclease (AS RNase) or saline. It was found that sexual behaviour (initiation of copulation as well as copulatory behavioural pattern) of experimental males was not changed, but the ability of these males to fertilize females was evidently suppressed. In addition to significantly lower weights of testes and epididymis, inhibition of seminiferous epithelium development (aspermatogenesis) associated with the absence of spermatozoa was determined in cauda epididymidis in experimental animals. However, Leydig cells remained without changes. Plasma testosterone levels of AS RNase treated males were not altered in comparison with the controls. Thus AS RNase specifically impaired spermatogenesis but did not influence androgen action and sexual behaviour.

Animals↗
PubMed1979

The binding of bull seminal ribonuclease and its carboxymethylated derivative to human leukaemic cells.

The binding of AS RNase and CM-AS RNase to leukaemic cells from patients with chronic lymphatic leukaemia was detected by indirect immunofluorescence. Leucocytes from normal donors or from patients with other hemoblastoses did not bind RNase. Experiments with lymphocytes from leukaemic patients and the lymphoblastoid cell lines in tissue culture revealed that both AS RNase solutions are probably bound mainly to leukaemic B lymphocytes.

Animals↗