PubMed Health⌕ Search

Biomedical subjects

R Keitel

Publications and source records attributed to R Keitel.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Transplantation antigen specific rosette test and its inhibition with autologous serum--a new immunologic method for predicting rejection crisis following allogeneic organ transplantation].

A combination of transplantation-antigen-specific rosette test with inhibition of rosette formation, using autologous serum, was used in postoperative follow-up checks on patients who had undergone allogeneic kidney transplantation and proved successful in early diagnosis or prediction of rejection episodes even before clinical manifestation. The numbers of antigen-detecting and antigen-binding cells differed considerably from each other, depending on patients who had undergone kidney transplantation. Almost complete inhibition of antigen detection was generally achieved by addition of patient serum. If sensitization to alloantigen in excess of the limit value (30 RBZ/10(3) KHZ) is accompanied by rosette formation with autologous serum addition in excess of about 18 RBZ/10(3) KHZ, clinically relevant rejection can be expected to occur after another two or three days and will have to be treated by immunosuppressives. Such partial or even complete elimination of rosette inhibition is usually only of short length (one day) and has rarely been observed to last longer. No rejection calling for treatment will develop, on the other hand, as long as blocking serum factors provide for high-stability inhibition of any bond of transplantation antigen (rosette formation). Constantly low rosette formation with serum addition and without was exhibited by control persons (blood donors, patients with cerebrocranial trauma) in daily examinations. Limit values of 18 or 30 RBZ/10(3) KHZ were not surpassed.

Graft Rejection↗
PubMed1986

[Immunologic characterization of the rejection of the allogenic transplanted kidney in pigs with and without immunosuppression].

After allogenic renal transplantation in pigs kinetics of the immunological reactivity have been investigated in order to diagnose rejection crisis. In a first series of 26 transplants without any immunosuppression we secured the diagnosis of rejection in 95% of cases of acute or chronic rejection by a combination of antigen-specific rosette test, inhibition of this parameter by autologous serum, complement dependent cytotoxicity and antibody dependent cell-mediated cytotoxicity. The antigen-specific rosette test reacts very early, 2-3 days before a bad clinical feeling in the course of acute rejection or 5-14 days by chronic rejection. Under the therapy with prednisolone and azathioprine we could not reach any prolongation of survival by arbitrary donor-recipient-selection. Under immunosuppression antibodies have never been observed by acute rejection in CDC and ADCC. In every case of acute rejection an increasing rosette formation of specific antigen binding cells appeared 2-3 days before an increasing of serum creatinine. In the case of other complications like infection or thrombosis this test is not reacting. However, by thrombosis of arteria or vena renalis there can be an increased specific rosette formation either independent of this process by beginning of immune reaction or by causal connection of both processes (necrotizing thrombotic rejection). So we have given the evidence, that the antigen-specific rosette test on a high level meets all requirements of a specific diagnosis of rejection under immunosuppression in pig.

Animals↗
PubMed1984

[The importance of active rosette-forming cells and specific antigen-binding cells in the diagnosis of rejection after allogeneic orthotopic kidney transplantation].

After allogeneic renal transplantation in 26 female pigs the kinetics of the immunological reactivity against the graft have been investigated with a specific test, the antigen specific rosette test and an unspecific test, the active E-rosette test. In acute and chronic rejection the level of antigen specific rosette forming cells reflects very well the clinical signs of rejection. Because of early occurrence of immunological reactivity in the case of frequent (daily) testing this test is suitable for a relative sure prediction of rejection episodes. In spite of their relative good correlations to the increase of serum creatinine, posttransplant increase and decrease of active rosette forming cells are not always in an uniform temporal relation to the rejection process. For that reason this test alone is not suitable for diagnosis of rejection. However, high preoperative values (greater than or equal to 18% active T cells) refer to an increased readiness to immunological reactivity of recipient against the graft and reflect contraindication to transplantation. If active rosette forming cells (greater than or equal to 18%) and antigen specific rosette forming cells show maxima at the same time, than follow in high significance strong cell mediated rejections. On this way the active E-rosette test completes the values of the antigen specific rosette test.

Animals↗
PubMed1984

[Antigen-specific rosette inhibition test with autologous serum--a possibility for the detection of blocking factors in chronic rejection of allogeneic orthotopic kidney transplants].

After allogeneic renal transplantation in 26 female pigs the kinetics of the immunological reactivity have been investigated in order to diagnose a rejection crisis. The animals were not treated with immunosuppressive substances. The antigen specific rosette test is an useful parameter for estimation of immune reactions against a graft. Moreover, the inhibition of this test by autologous serum taken in the course of a chronic graft rejection is caused by blocking factors. Therefore this inhibition test would be suitable for an exact determination of specific immune reaction against the graft. By exclusion of false positive results by means of the rosette reaction test a high significant correlation between the antigen specific rosette formation and the clinical symptoms of the rejection could be observed. As long as blocking factors are protecting the graft against activities of immunocompetent cells respectively their effector molecules, recipient serum is able to inhibit the rosette formation. On the other hand a strong increase of rosette forming cells in a pig whose serum does not show an inhibitory activity is correlated with clinical symptoms of a rejection.

Animals↗
PubMed1983

[Employment of the antigen-specific rosette test in the diagnosis of rejection following allogeneic orthotopic kidney transplantation in the pig].

Investigations of the course were performed by means of an antigenspecific rosette test using a poolantigen from tissue samples of approximately 100 pigspleens with the help of the model of allogenic renal transplantation in 26 female pigs. The animals received no immunosuppressive treatment. In our study with this test 75% all of the rejection episodes by clinical acute and chronic rejection were predictably. In acute rejection a maximum rosette forming cell response was examined in general 2-3 days before a pathological rise of serum creatinine or in the course of a bad clinical state. Under chronic rejection this reaction can be seen 5-14 days before the kidney function will go poor. In spite of the high individuality of original curves statistical analyses indicate a good correlation of the number of antigenbinding cells toward pathological deviation of serum creatinine, as long as blocking factors not protect the transplant against the attack of persisting immunocompetent cells or their effectors. These blocking factors can be monitored in a rosette inhibition test with autolog serum.

Animals↗
PubMed1978

[Biochemical and hematological parameters during extracorporeal heterologous perfusion with a porcine liver in acute liver failure].

The authors report on biochemical and hematologic investigations during 6 extracorporeal heterologous perfusions by means of porcine livers in 4 patients suffering from acute hepatic failure. The findings stress the functioning of porcine liver in the extracorporeal system. All livers produced bile with higher values of bilirubin and pH than found in serum. At each perfusion the serum levels of bilirubin decreased. Activities of serum enzymes (GOT, GPT, GLDH, gamma-GT, alkaline phosphatase) and the levels of potassium and sodium behaved differently. This could be explained by different damages of the porcine livers during perfusion which always occur. In 3 perfusions decreased leucocyte counts were observed, explicable immunologically. Extracorporeal heterologous perfusion by means of an alien liver is considered a possible way for temporary replacement of liver function and for removing toxins from the host. Success in single cases with reasonable indication are considered possible. The patients endured the perfusions well. After transitory improvement of their general conditions they succumbed from their severe diseases, though.

Animals↗
PubMed1978

[Morphological studies on swine livers after extracorporeal perfusion].

Morphologic examination of 6 porcine livers after extracorporeal perfusion showed toxic damages of parenchyma with and without necrosis, dilatation and distension of sinusoids with and without hemorrhage and accumulation of inflammatory cells, activated stellate cells, different distributions and loss of glycogen. These findings in the liver could be caused as well by inflow of toxins and cells from the patient, as by increasing damage of the livers under the unphysiological conditions of extracorporeal circulation. The authors point at possible immunologic responses and give their opinion on the question of "vitality" of extracorporeally perfused porcine livers.

Animals↗
PubMed1977

Quantitative alterations of immune serum globulin concentrations in pigs transplanted with a renal allograft.

The variation of immune serum globulin concentrations in 14 pigs was determined after unilateral allogenic renal transplantation. Measures by which it is possible to exert certain immunological influences were not taken. Subsequent to transplantation there was observed a significant decrease in both IgM and IgG which was not correlated with the behaviour of plasma proteins and albumin. Because of the relatively small loss of IgG in the urine of animals on which transplantations were performed, this cannot be considered to be the cause of the decrease in immunoglobulin. It was already on the 3rd day after transplantation that an increase in IgM was observed which after reaching a peak of about + 30% was again followed by a distinct decrease of which the minimum was noted between the 6th and 15th days after transplantation. 10 animals died within the first phase, and in 4 of them death occurred on account of rejection for which histological evidence could be obtained. Although 3 of the 4 animals surviving for a longer period of time were also observed to suffer from distinct rejective crises between the 8th and 15th day after transplantation, they were able to overcome those crises without any therapeutical intervention. After some time, however, they were experiencing another IgM peak (this time greater than + 80%) which was followed, after 3 to 11 days, but the final crisis of rejection and death of the animal. In a few cases, glomerular IgM deposits were found in transplanted kidneys.

Animals↗
PubMed1977

[Animal model for the study of the anhepatic state].

Hepatectomy in the pig is impossible without simultaneous removal of intrahepatic caval vein. The authors covered the vascular gap using a siliconized glass prosthesis, completed with rubber tubes. 16 animals were operated upon in this manner and survived between 6 and 34 hours. In only two cases thrombi were found in the prosthesis.

Animals↗
PubMed1976

[Morphological, clinical and biochemical findings on the swine-liver after heterologous perfusion for treatment of fatal ammonium bichromate poisoning].

A 23-year old man died after intake of ammonium bichromate. For treatment among others was used the extracorporal heterologous liver perfusion with the liver of a pig. Therefore technical problems, clinical and biochemical findings as well as pathologo-anatomical changes on the livers of pigs after heterologous perfusion are reported and their significance as well as pathogenesis are discussed taking into consideration literary data.

Adult↗