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Biomedical subjects

C Hammer

Publications and source records attributed to C Hammer.

At least 253 records · Page 14Linked to original sources
PubMed1982

[Heart transplantation: successful treatment of postoperative complications. Case report with 19 months' follow-up].

In March, 1981, a 37-year old patient underwent cardiac transplantation, the first to be performed in Germany since 1969. Subsequent to the successful procedure, the patient has now been followed for more than 19 months. The indication for the intervention was established on the basis of endstage coronary artery disease. The operation was performed according to the technique of Lower and Shumway. Immunosuppression, in the early postoperative phase, was carried out with antithymocyte globulin, azathioprine and corticosteroids with administration oriented on the T-lymphocyte and total leukocyte counts as well as analysis of myocardial biopsies. In the late postoperative course, dosage of immunosuppressive agents was based almost exclusively on biopsy findings. Within the course of immunosuppressive therapy for cardiac transplantation, in particular, initial experience was gained with the use of antithymocyte globulin which was given in dosages of up to 12 mg/kg daily. The antithymocyte globulin proved effective for more than six weeks postoperatively. The alterations in immunosuppressive treatment necessitated by two gastrointestinal complications (perforated gastric ulcer, perforation of the small intestine) enabled a comparative analysis of the results of therapy with cyclosporin A given orally, intravascularly and intravenously. The Patient continues to be maintained on a regimen of cyclosporin A and corticosteroids and his general condition is good. For future cardiac transplantations, in the early postoperative course, alternating treatment with antithymocyte globulin, azathioprine and corticosteroids, on the one hand, with cyclosporin A and corticosteroids, on the other hand, would seem meaningful both to minimize adverse reactions as well as to provide effective immunosuppression. The experience rendered would promise to facilitate management of patients after cardiac transplantation.

Adolescent↗
PubMed1981

Suppressor cell activity in patients with tonsillar carcinoma.

The follow-up of suppressor cell activity in patients with squamous cell carcinoma of the tonsil seems to give anew insight into the clinical situation of a patient. In 54 patients with tonsillar carcinoma followed over 3 years, regulator cells, i.e., suppressor cells, have been investigated. The patients with bad clinical conditions show continuous increase with suppressor activity already at the time of operation, especially in cultures with activated suppressor cells. The new therapeutical treatment of cancer patients should be directed in such a way that the unfavourable suppressor cell be eliminated while the cytotoxic effector cell be stimulated.

Antibody Formation↗
PubMed1981

[Immunofluorescence of oral swabs--a new method for early recognition of recurrencies in patients with tonsillar carcinoma? (author's transl)].

Sera of patients with squamous cell carcinoma of the tonsil contain antibodies of IgG type, which seem to be directed against individual specific and group specific tumour cell surface antigen. Such antibodies which react with antigen on tumour cells of operation speciems also also mark cells from oral swabs, which are supposed to be of malignant origine. This suggestion is supported by the observation, that 3-6 months after the first positive findings recurrancy occurs. Therefore this method would be a simple, non invasive possibility for early detection of recurrancy in patient with tonsillar carcinoma and thus be of prognostic and diagnostic value.

Adult↗
PubMed1981

Suppressor cell activity in human renal allograft recipients.

Eighty-nine kidney allograft recipients with one or more graft rejection episodes were monitored for suppressor cell activity in the peripheral blood at two day intervals. The impact of rejection and immunosuppressive therapy (ALG) on the one hand and the recovery of suppressor activity on the other hand during long-term graft survival could be demonstrated. The suppressor activity of peripheral lymphocytes after amplification in vitro by Concanavalin A was measured on PHA stimulated cultures. It is reduced after operation trauma and during rejection episodes when tested in PHA stimulated cultures. This loss of suppressor activity is even more marked when suppressor cells are added to allogeneic mixed lymphocyte reactions. Depletion of adherent cells reduces this suppressor activity, indicating that two different populations of mononuclear cells are responsible for this in vitro effect. Immunosuppressive therapy and additional ALG treatment abolishes suppressor activity in most cases. Highest suppressor activity was monitored in seven patients with excellent long term graft survival after ALG therapy.

Concanavalin A↗
PubMed1981

[Detection of antitumor-antibodies in patients with tonsillar carcinoma (author's transl)].

48 patients with squamous cell carcinoma of the tonsil were tested for autologous and allogeneic antitumor-antibodies directed against squamous cell carcinoma cells. The use of autologous serum avoids the need of absorption. Antibodies detected at the time of tumor extirpation could also be used to label their specific antigen of cells from swabs of the oral cavity. Such a surface fluoreszens appeared in 5 patients between 3 and 6 months before recurrency and could be followed during the whole course of disease. Besides very low amounts of antibodies of the IgA- and IgM-class the main portion was IgG. While these antibodies reacted in a similar degree with allogeneic tonsillar carcinomas cross reaction with other allogeneic tumor cells (bladder--kidney carcinoma) could not be detected.

Antibodies, Neoplasm↗
PubMed1981

The prognostic value of immunofluorescence from oral swabs in patients with tonsillar carcinoma.

Fifty patients with various stages of squamous cell carcinoma of the tonsil were included in the study. All sera of these patients contained antitumor antibodies of the IgG type, which seem to be directed against individual-specific and group-specific tumor cell surface antigen. Different dilutions of autologous antibodies were tested against the tumor specimen as well as against oral swabs taken from the patients after therapy. The autologous antitumor antibodies were visualized on the tumor cell and on the cytology swab by FITC conjugated antibodies from rabbits (anti-human IgG) in the indirect immunofluorescent assay. Although the use of autologous sera avoids the need of absorption, absorption of sera with autologous tumor cells eliminates the reaction completely, with allogenic tumors partially (Lewis et al., 1972). The prognostic value of humoral immune response in detecting recurrence (immunofluorescence study of oral swabs) is shown by the following observation. After operation swabs taken from the patient's tumor sites are immunofluorescence negative. In case of recurrence, the cells became positive 3-6 months before local recurrence of the tumor could be clinically detected.

Antibodies, Neoplasm↗
PubMed1980

Role of complement activation in a model of adult respiratory distress syndrome.

The adult respiratory distress syndrome is characterized by arterial hypoxemia as a result of increased alveolar capillary permeability to serum proteins in the setting of normal capillary hydrostatic pressures. Because bacterial sepsis is prominent among the various diverse conditions associated with altered alveolar capillary permeability, we studied the effect of bacteremia with attendant complement activation on the sequestration of microorganisms and the leakage of albumin in the lungs of guinea pigs. Pneumococci were injected intravenously into guinea pigs and their localization was studied. Unlike normal guinea pigs, complement-depleted guinea pigs did not localize injected bacteria to the lungs. Preopsonization of organisms did not correct this defect in pulmonary localization of bacteria in complement-depleted animals, suggesting that a fluid-phase component of complement activation was required. Genetically C5-deficient mice showed no pulmonary localization of bacteria. C5-sufficient mice demonstrated the usual pulmonary localization, thus further suggesting that the activation of C5 might be important in this localization. The infusion of activated C5 increased alveolar capillary permeability to serum proteins as assayed by the amount of radioactive albumin sequestered in the lung. Neutropenic animals did not develop altered capillary permeability after challenge with activated C5. Thus, complement activation through C5, in the presence of neutrophils, induces alterations in pulmonary alveolar capillary permeability and causes localization of bacteria to the pulmonary parenchyma. Complement activation in other disease states could potentially result in similar clinical manifestations.

Capillary Permeability↗
PubMed1980

Characterization of lymphoma-derived cell lines: comparison of cell lines positive and negative for Epstein-Barr virus nuclear antigen. II. Surface markers.

Fifteen of 16 lymphoma-derived cell lines and the Faji and P3HR1 cell lines were characterized with regard to certain surface markers, particularly immunoglobulins, complement receptors, Epstein-Barr virus (EBV) receptors, and Fc receptors. Ten lines positive for EBV nuclear antigen (EB-pos) were stained weakly or not at all by antihuman immunoglobulin fluorescein isothiocyanate conjugates, whereas EBV nuclear antigen negative (EB-neg) cell lines stained brightly. EB-pos lines frequently manifested Fc receptors, particularly for 7S antibody, whereas EB-neg lines did not. Receptors for the C3b component of complement and for EBV, which correlated significantly with each other, were expressed to a much lesser extent by EB-neg lines than by EB-pos lines. These findings are pertinent to an understanding of the infrequent association of this virus with American undifferentiated lymphomas of the Burkitt's and non-Burkitt's types.

Antigens, Viral↗
PubMed1980

[Immunological studies in patients with carcinomas of the floor of the mouth and of the tonsils (author's transl)].

New insights into the cellular control mechanisms of immune reactivity may become important to physicians who manage patients with cancer. In 29 patients with tonsillar carcinoma, not only humoral, but also cellular mechanisms with major emphasis on regulator cells, i.e. suppressor cells, have been investigated. It seems from these cells, as if an unspecific suppressive activity measured in these patients could give a better opportunity to trace the immunological immune reaction against this tumor and give thus a chance for "specific immunotherapeutic regimens" which should on the one hand stress the activation of the host's tumor cytotoxicity and on the other hand eliminate the function of suppressor cells.

Antibody Formation↗
PubMed1980

[Assessment of lymphatic cells in natural and artificial allografts (author's transl)].

Transfer of "passenger lymphocytes" within a transplant initiates allogeneic rejection. As compared with peripheral lymphocytes, which show no different in vitro reaction, infiltrating cells from natural and artificial grafts are good stimulator, bad responder but powerful suppressor cells. These T-suppressor cells, which arose during rejection are enriched in the graft. The assumption is that the function of this relatively small number of lymphocytes is to suppress the local immunological rejection mechanisms. They cannot inhibit the proliferation of peripheral cytotoxic cells.

Animals↗
PubMed1979

Mitigation of hyperacute rejection by antilymphocyte globulin (ALG).

In HR, primarily humoral immunologic factors trigger a sequence of events that finally destroys the transplanted organ. Unspecific trapping of WBC diminishes the RBF, especially in the first compartment--the cortex. Pretreatment with ALG is able to suppress this cellular participation partially, thus postponing the stop of RBF without preventing the influence of humoral factors on the graft. As shown by pathologic and functional criteria recorded for 8 hr, an exclusive measurement of total RBF does not reflect an inhibition of the course of HR.

Acute Disease↗
PubMed1979

[Clinical significance of immunological findings for the survival time of kidney transplants with antilymphocyte globulin therapy].

A balanced combination of immunosuppressive regimens like cortisone, azathioprine and ALG can not only reduce the frequency, but also the severity of rejection episodes in kidney transplant patients. Addition of ALG influences the lymphocyte populations, especially T-lymphocytes. The significant reduction produced obviously includes cytotoxic effector lymphocytes as well as socalled regulator cells (suppressor cells). It seems as if this beneficial function for the graft is not only reduced under immunosuppressive therapy and administration of ALG, but disappears during rejection crises. The results indicate, however, that these cell populations recover quickly after finishing the immunosuppressive regimen.

Antilymphocyte Serum↗
PubMed1979

[Prolonged survival time of xenogeneic kidney transplants following intravenous application of concanavalin A].

Concanavalin A is used as a mitogen for the stimulation of lymphocytes in vitro. It increases the proliferation of different populations of lymphocytes and activates the function of regulator lymphocytes. This effect appears to be modified in vivo in such a way that daily IV application prolongs survival times of allogeneic and xenogeneic kidney grafts significantly. The reason seems to be an influence on behavior, which is reflected in a pronounced peripheral lymphopenia. To support and investigate this mechanism, further combinations of antilymphocyte globulin, fox red blood cells, and Concanavalin A pretreatment were used in pilot studies.

Animals↗
PubMed1978

Immunologic changes in regional lymph nodes of melanoma patients.

In tumor-draining lymph nodes, humoral immunity is diverted from individually specific, cytotoxic anti-membrane AB to less specific anti-cytoplasmic AB with progression of the disease. Auto-anti-anti-bodies and suppressor cells seem to be involved in the failure of control of metastasis.

Antibodies, Neoplasm↗