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Biomedical subjects

G Adamczyk

Publications and source records attributed to G Adamczyk.

At least 19 recordsLinked to original sources
PubMed2000

Functional studies on sciatic nerve blood flow in respect to its vascular supply and tonic neural activity.

An introduction of laser flow meters for a continuous measurements of a tissue blood flow has opened new avenues for an accurate assessment blood flow in peripheral nerves. The aim of our study was: 1) to carry out a functional verification of anatomical sources of a sciatic nerve blood supply in the rat; 2) develop a measurement technique to facilitate standardisation of results; 3) to determine the role of nerve fibres tonic activity in the maintenance of a resting blood flow in the sciatic nerve. Based on results of the present study the following conclusions have been drawn out: 1) in order to obtain a real values of the blood flow through the sciatic nerve it is necessary to remove its muscular fascia; 2) an uninjured epineurium plays a crucial role in maintaining the resting blood flow; 3) major blood supply of sciatic nerve comes from inferior gluteal and popliteal arteries; 4) the tonic neural activity plays a role in the maintenance of the resting sciatic nerve blood flow in anaesthetised rats.

Anesthetics, Local↗
PubMed1993

Donor-specific transfusion does not mitigate but accelerates rejection of intravenously transplanted lymphocytes.

Rat allogeneic heart or kidney grafts are rejected within 6 to 8 days, whereas lymphoid cells from the same donor transplanted intravenously across the MHC barrier are eliminated, in most part, within 6 h. We have found that donor specific transfusions (DST) significantly prolonged the survival time of organ allograft but accelerated destruction of i.v. transplanted lymphocytes. Partial elimination of transplanted lymphocytes was observed after third-party blood transfusion. Blocking of the MHC class I and II determinants on transplanted lymphocytes with monoclonal antibodies OX18 and OX6 did not have effect on the lymphocyte elimination kinetics. The effect of hyperacute elimination of allogeneic lymphocytes by DST-treated rats could be adoptively transferred with their sera, although the cytotoxic antibody titer against donor MHC antigens was in these sera low or hardly detectable. DST-recipient sera contained donor-specific IgG and IgM alloantibodies. It seems that these "enhancing" antibodies could block the MHC products on organ graft endothelial cells, thereby preventing attack of circulating donor-specific cytotoxic lymphocytes. At the same time they may opsonize the transplanted lymphocytes, thereby facilitating their recognition and removal in the lymphoid organs of graft recipient.

Animals↗
PubMed1991

[Risk of CMV infection and illness after kidney transplantation].

Between 1980 and 1986 465 cadaveric kidney transplants were performed at the Kidney Transplant Centre Berlin-Friedrichshain. The post-transplant risk to acquire a cytomegalovirus (CMV) infection depended on the preoperative CMV antibody status of donor and recipient, on the nettoimmunosuppression and on the recipient's age. The highest infection rate and the most serious courses showed seronegative recipients from seropositive donors. The typical time interval of clinical manifestation included the postoperative months 1-3. A significant dependence of the frequency of infection on different immunosuppressive protocols could not be proven. But there was a significant coincidence between CMV infection and rejection crises. In spite of the raised frequency of rejection crises an influence of the CMV infection on the 1-year-graft and patient survival rates could not be demonstrated. Both an early diagnosis and an adequate therapy are of particular importance.

Age Factors↗
PubMed1990

[Microbial colonization of the upper respiratory tracts of day care children in relation to acute morbidity episodes].

The upper respiratory tracts of 20 children attending a crèche were studied for bacteria up to the 128th day of crèche attendance. To this end nose and throat swabs as well as double blood withdrawals were to determine antibodies against various respiratory viruses. The germ spectrum thus obtained was correlated with the acute pathological processes occurring during the period of investigation. In addition to the normal flora, the nasopharynx of infection-stable children was, with one exception, only populated with gram-positive pathopotent bacteria during the first four months of crèche attendance. In infection-labile children, however, gram-negative pathopotent bacteria, blastomycetes of the Candida group as well as Mycoplasma, virus and mixed infections were discovered apart from gram-positive bacteria. This broad germ spectrum should be taken into wider consideration in the chemotherapy of respiratory infections.

Bacteria↗
PubMed1989

Prolongation of heart graft survival and spleen suppressor cell activity after donor specific blood transfusions in rats differing across the MHC.

The aim of the study was the prolongation of heart allograft survival in rats after DST (donor specific blood transfusion), the characterization of T and B lymphocyte phenotypes in peripheral blood, spleen and lymph nodes and the evaluation of specific and nonspecific suppressor cell activity of spleen and blood lymphocytes of DST rats. Pretreatment of Wistar recipients with one, two and three doses of DST-s prolonged the heterotopic August graft survival to 11.0, 12.3 and 11.4 days, respectively (rats differed across the MHC). Spleen lymphocytes of transfused rats showed significant nonspecific suppressive activity in culture with syngeneic spleen lymphocytes of nontransfused rats stimulated with PHA, but not in culture with blood lymphocytes. Blood lymphocytes of transfused rats did not show any nonspecific suppressive activity. Spleen and blood lymphocytes of transfused rats did not demonstrate any specific suppressive activity in allogeneic MLC. The ratio of W3/25+/OX8+ (Th+/Tsup/cyt+) cells in peripheral blood was found increased in DST rats due to the decrease in the percentage of OX8+ cells whereas the opposite effect was observed with spleen cells (increase in the percentage of OX8+ cells after one DST). The number of OX6+ (Ia positive) cells and B cells in all transfused rats was found unchanged comparing with untreated animals.

Animals↗
PubMed1987

[Persistence of antibodies of the IgG class against cytomegaloviruses in blood donors].

High titre plasmas gained from blood donors are the initial material used for producing human immunoglobulin containing cytomegalovirus antibodies (CMV-HIG). For this purpose the sera gained from 467 permanent donors at the District Institute for Blood and Transfusion Service in Berlin were investigated on their CMV antibody content of IgG class by means of an indirect immunofluorescence test (IFT). The infection rate of blood donors amounted to 62% (291/467). CMV-IgG titre greater than or equal to 1:40 was determined in 88 sera (18.8%) and greater than or equal to 1:160 in 14 sera (3%). Two CMV-HIG laboratory samples (charges 3113 and 3117) were produced from these plasmas. Particularly immunoglobulin fraction of charge 3117 (No. 3117 N II) revealed excellent antibody titres (IFT 1:640 [CMV-IgG] or 1:40 [CMV-IgM] respectively, neutralisation test 1:32). Checks made with the donors' CMV-IgG titres after repeated application of plasmapheresis resulted in maximal titres changes of two dilution stages in a period of 15 months. Thus, in producing CMV-HIG a sure, tested pool of donors can be resorted to.

Antibodies, Viral↗
PubMed1985

[incidence of cytomegalovirus infections following transplantation of kidneys from seropositive and seronegative donors].

Serum samples of 110 recipients of kidney transplants and the 100 donors belonging to them taken before the transplantation were examined for complement-binding antibodies against cytomegaloviruses. A clear influence of the cytomegalovirus antibody state of donor and recipient on the cytomegalovirus infection appearing after transplantation, serologically ascertained by cytomegalovirus-IgM-antibody proof or seroconversion and fourfold increase of the titre in the complement-binding reaction, respectively, could be made evident. Cytomegalovirus negative recipients of kidneys of cytomegalovirus positive donors had significantly more infections than seronegative recipients of kidneys of seronegative donors (50% vs. 16%, p less than 0.05). According to the infection rate the seropositive recipients stand with about 30% between these two groups. It seems that in these recipients the serological state of the donors has no influence. These findings make evident that seronegative recipients receive the cytomegaloviruses essentially with the transplant, whereas the cytomegalovirus infections in seropositive recipients are endogenous cytomegalovirus reactivations caused by therapy.

Adolescent↗
PubMed1985

[Serologic diagnosis of primary cytomegalovirus infections in patients following kidney transplantation using the indirect immunofluorescence technic and the complement-fixation test].

Sera of 22 recipients of kidney transplants with clinically and serologically (complement binding reaction) ascertained cytomegalovirus infection were retrospectively examined for virus-specific antibodies of the class IgM by means of the indirect immunofluorescence test. Already two to five days after the appearance of the adequate clinical symptoms (leucopenia, fever, T-lymphocytopenia, increase of creatinine and thrombocytopenia) CMV-IgM-antibodies could be proved. On average a positive complement binding reaction was found only two weeks later. In other 13 patients of the actual control programme the CMV-IgM-antibody findings first obtained were compared with the results of the complement fixing reaction obtained later. Neither falsely positive nor falsely negative results could be found.

Antibodies, Viral↗
PubMed1984

[Anti-Thomsen-Friedenreich (anti-T) antibody titer in kidney transplant recipients].

In 43 recipients of allogenic cadaver kidneys before and three times a week after transplantation to the discharge from the hospital care the antibody titre against the Thomsen-Friedenreich-antigen (Anti-T) was determined and the score value was calculated from the agglutination intensity. A prognostic significance of the value got before operation could not be found. No changes of the titre appeared under the influence of the postoperatively performed immunosuppression as well as in connection with rejection crises. In 9 patients with clinically manifest systemic infections (8 cytomegalovirus infections, 1 bacterial infection) unequivocal (greater than or equal to 8 fold) increases of the anti-T-titre could be proved. These findings speak for an infection-induced formation of these cross-reacting anti-T-antibodies.

Adolescent↗
PubMed1983

Incidence of influenza C virus in Czechoslovakia and German Democratic Republic.

Out of 1091 and 2275 influenza virus strains isolated in Czechoslovakia (C.S.S.R.) and German Democratic Republic (G.D.R.) from 1969 to 1981, six and two were type C strains. All type C strains were isolated in the course of type A or B influenza epidemics. Double-diffusion tests indicated a relationship between the type C strains isolated in both countries in 1981 and the prototype strain C/Taylor/49; however, haemagglutination inhibition test (HIT) showed a heterogeneity within the 1981 group of viruses and their antigenic distinctness from the strain C/Taylor/49. The low number of type C isolates was in a sharp contrast with the antibody titres found in most adult sera. Only 10-30% of 275 and 2750 serum samples collected from persons aged 6-50 years in Czechoslovakia and G.D.R., respectively, were negative. The percentage of positive sera rose steadily in children 2-4 years of age. These serological findings suggest that influenza C virus was more or less permanently circulating among population, but the disease caused by it tends to take an inapparent or very mild course, so that the virus was isolated only exceptionally.

Adolescent↗
PubMed1983

[Primary cytomegalovirus infection as a risk factor following kidney transplantation].

Of 201 patients who received cadaver kidneys in the kidney transplant centre in Berlin between June 1978 and December 1981 114 (56.7%) already had complement-binding antibodies against cytomegaloviruses (CMV) before transplantation, 87 (43.3% were seronegative. After transplantation a recurring CMV infection was detected in 36/114 patients and a primary CMV infection in 27/87 patients (31.6% and 31.0% respectively). At dismissal from ward care these patients already had a significantly higher rate of transplant failure than those free of CMV infection. This negative effect of the infection was reinforced by the additional administration of a Prednisolone bolus for the treatment of the rejection crisis associated with CMV. At the same time immunological protection was further suppressed. Thus, in comparison with patients with primary CMV infection not treated with Prednisolone bolus, those with primary CMV infection and parallel treatment with a Prednisolone bolus had a higher rate of T-lymphocytopenia and a significantly delayed humoral immune response to CMV. Together with the usually present leukocytopenia, these findings explain the especially high risk of potentially fatal superinfections in this period. Diagnosis of CMV infection on the basis of clinical symptoms and haematological changes must be speedy. A therapy which is effective with regard to life (although symptomatic) comprises the temporary reduction of the azathioprine dose, the administration of antibiotics and the infusion of human gamma-globulin. It might be possible to avoid primary CMV infection, which presents a particularly great risk, by vaccination of the potential transplant recipient.

Adolescent↗