Search PubMed⌕ Search

Biomedical subjects

C Kaplan

Publications and source records attributed to C Kaplan.

At least 181 records · Page 10Linked to original sources
PubMed1986

[Immunization against the ZWa (PLA1) platelet antigen: group at risk, prevention of complications. Apropos of 132 cases].

The identification of anti-ZWa (-PLA1) alloimmunisation is not very frequent. It can be observed in most perinatal alloimmune thrombocytopenias (PAT) and rare post transfusional purpuras (PTP). On the other hand, the clinical consequences of these immunisations are often dramatic, particularly for the foetuses for which there has been no prevention so far. The retrospective study of 132 cases, 123 PAT and 9 PTP, shows the possible irreversible complications for 18% of the newborns with PAT, but especially for 10% of the foetuses which will show PAT at birth. HLA markers are very useful to detect the people who are likely to develop an anti-PLA1 immunization for they are PLA1 negative and HLA DR3. Then, it becomes possible to prevent the complications of these immunisations. It is what we tried to do through the diagnosis and the treatment of PAT in 3 foetuses.

Antigens, Human Platelet↗
PubMed1986

[Characteristic parameters of the population of circulating DNA in cases of disseminated lupus erythematosus ].

Important quantities of circulating DNA (up to congruent to 50 micrograms/ml) have been shown to be present in the sera of patients with serious systemic lupus erythematosus. This DNA is double-stranded, as demonstrated by colorimetric, enzymatic and biophysic tests. The circulating DNA population is made up of a main fraction at 250 base pairs and a heterogeneous tail up to 300 bases pairs, as demonstrated by electrophoretic measures on polyacrylamide gel. After hydrolysis in limited conditions with DNAse I and 32P labelling, the repartition of autoradiographed material confirms the reality of a main peak and of a more dispersed tail.

Autoradiography↗
PubMed1985

[Intrafamilial renal transplantation in children after donor blood transfusions].

This article represents an update of our experience with deliberate donor specific blood transfusions (D.S.T.) prior to living-related renal transplantation in children. Eighteen recipients with a negative cross- match to donor T and B cells entered the D.S.T. protocol without regard to the results of the mixed lymphocyte cultures and third party transfusion. The D.S.T. procedure involves the administration of fresh packed cells on 2 or 3 separate occasions at 4 weeks intervals. The potential recipient's sensitization is closely monitored against donor's isolated T and B lymphocytes and against a random panel. This immunological monitoring is done 10 to 20 days after each D.S.T. and just prior to grafting. A negative T and B cross-match at 37 degrees C is a pre-requisite for transplantation. Sixteen patients have been transplanted. All kidneys are functioning with follow-ups ranging from 6 to 48 months; 10 patients have normal renal function, 2 of them experienced reversible acute rejection and 6 have chronic rejection. The benefits derived from pretransplant D.S.T. in parental renal transplantation appear to be substantial, although the nature of the various immunological mechanisms remains unclear.

Adolescent↗
PubMed1985

[Neonatal alloimmune thrombopenia].

88 families in which 84 cases of neonatal alloimmune thrombocytopenia (NAT) occurred, were studied. In 84 families, the NAT was the consequence of an incompatibility in the PLA system. Furthermore, the phenotype HLA-DR3 increases greatly the risk of immunisation (RR: 76,5). The importance of the risk of neurological sequellae was shown by the clinical study (about 25% of the surviving neonates). The occurrence of the accident at the first birth of a PLA1 positive child in a sibship was frequent (59%). In addition, the NAT recurred at each birth of a PLA1 positive child with only five exceptions. All of them concern a female neonate and this might be meaningful. Therapeutical data are heterogeneous and difficult to interpret. However, it appears that the prevention of obstetrical traumatism by caesarean section and compatible platelet transfusions are useful. It is too early to evaluate the efficacy of prenatal transfusions of mother's washed platelets. However, in the two cases in which we use them, they gave a good and sustained platelet count increment. The prenatal diagnosis of NAT and the PLA grouping of the foetus has been proposed in three cases and are feasible at 20 weeks of pregnancy.

Blood Platelets↗
PubMed1985

Generation of mouse cytolytic T cells against human concanavalin A blasts. Involvement of non-MHC determinants in the antihuman response.

Normal human peripheral blood lymphocytes (PBL) are incapable of eliciting a significant murine cytotoxic T cell (CTL) response either in vivo or in vitro. However, using a primary in vivo and secondary in vitro stimulation with lectin-activated PBL, Thy-l-positive cytotoxic cells were produced. The antigens that these T-cells identified were independent of the serum source employed in the culture medium used for lectin activation. The cells always preferentially lysed cells from the immunizing individual but were also able to lyse target cells from unrelated individuals, regardless of HLA identity or disparity with the immunizing individual, suggesting the presence of both a private (possibly class II antigens) and public specificity. Using the lymphoblasts of different family members as immunogen and targets there was slight preference of the CTL for HLA-identical targets with no apparent difference between the lysis exhibited against semiidentical and nonidentical subjects. Monoclonal antibodies directed against HLA DR or beta 2-microglobulin failed to inhibit the cytotoxicity observed in these experiments. It is suggested that under these circumstances of xenogeneic education, non-MHC-restricted T cells may become cytotoxic, and this model may serve as a useful probe to investigate some of the less-well-defined aspects of the T cell repertoire.

Animals↗
PubMed1985

Renal pathology of prenatally diagnosed nephrosis.

Congenital Finnish nephrosis is a rare autosomal-recessive disorder, usually fatal at an early age. The disease is prenatally detected through elevation of alpha fetoprotein in the amniotic fluid of pregnancies at risk. This originates from fetal proteinuria. Maternal serum alpha fetoprotein reflects amniotic fluid levels. We describe a case of congenital nephrosis diagnosed through maternal serum screening in a low-risk population. The characteristic histology of congenital nephrosis is demonstrated, and evidence of proteinuria by electron microscopy, light microscopy, and immunofluorescence is presented.

Adult↗
PubMed1985

[Abnormal regulation in the production of IL2 in Hodgkin's disease].

Patients with active Hodgkin's disease demonstrate a significant depression of cellular immunity. The present study, performed with lymphocytes from 16 untreated patients with active Hodgkin's disease and 13 healthy control volunteers, demonstrate an equivalent IL 2 production in vitro in both groups. Our results, however, demonstrate an abnormal regulation of IL 2 production in patients. A negative control of IL 2 production involving monocytes producing PGE 2 able to induce radiosensitive suppressor T lymphocytes, has been identified previously with cells from healthy donors. In the present study we demonstrate that this negative control is hyper functioning with cells from Hodgkin's disease patients.

Hodgkin Disease↗
PubMed1983

Improved culture conditions for quantitative evaluation of interleukin 2 production by frozen human lymphocytes.

Several culture parameters were studied in order to establish methods for optimal and reproducible production of interleukin 2 (IL2) by thawed lymphocytes. Standard conditions, considered optimal for production by freshly separated lymphocytes (culture medium RPMI 1640 + 1% normal human serum + 10 micrograms/ml PHA), gave low and poorly reproducible results. An increased concentration of human serum (10 and 20%) in the medium improved production but best results were obtained by adding polyethylene glycol (PEG 6000, 0.1 mg/ml) to the culture medium. Furthermore, with the addition of PEG 6000, results became highly reproducible, thus permitting valid comparison of in vitro IL2 production by lymphocytes from normal donors and patients.

Blood↗
PubMed1982

[Effects of blood transfusions on kidney transplants].

In a retrospective study involving 24 transplantation centres and 858 cadaveric kidney recipients, a number of transfusion factors affecting transplant survival were identified. The best results were observed with the most intensive transfusion schedules including at least one transfusion per month. The optimal number of transfusions varied from 6 to 20. However, it was impossible to determine whether a minimal interval was required between the last perfusion and transplantation, or whether the effect of each transfusion was limited in time. Qualitatively, it appeared that whole blood and packed red cells gave better results than leucocyte-deprived blood. Moreover, fresh blood taken less than 3 days before the transfusion clearly proved more effective than blood stored for more than 5 days. All this suggests that live leucocytes and platelets may be important factors. The mechanism by which blood transfusions improve the outcome of kidney transplants remains unknown.

Blood Transfusion↗
PubMed1982

Identification of erythrocytes in intervillous thrombi: a study using immunoperoxidase identification of hemoglobins.

The origin of the erythrocytes in intervillous thrombi has never been definitively established. Fetal hemoglobin-containing erythrocytes were identified in histologic sections of intervillous thrombi using the peroxidase-antiperoxidase unlabeled antibody method. In 85 per cent of intervillous thrombi containing well-preserved erythrocytes, fetal hemoglobin-containing cells were found in quantities well in excess of the number seen in maternal blood. This definitely demonstrates the presence of erythrocytes of fetal origin in intervillous thrombi. Possible pathogenic mechanisms of intervillous thrombosis and fetal-maternal hemorrhage are discussed.

Chorionic Villi↗