Biomedical subjects

Sabine Scherer

Publications and source records attributed to Sabine Scherer.

5 recordsLinked to original sources

PubMed2005

Analysis of KIR ligand incompatibility in human renal transplantation.

Natural killer cells express killer immunoglobulin-like receptors (KIR) that bind to MHC class I antigens. Lack of self-MHC on the target cell can cause NK-cell mediated killing. Here, we analyzed the effect of KIR ligand incompatiblity on renal allograft survival in humans. Kidney recipient/donor pairs were separated according to their HLA-Cw alleles and HLA-Bw4 specificity which are considered epitopes for KIR. A total of 2,757 renal transplants were examined. Graft survival rates were computed according to the Kaplan-Meier method. No effect of KIR ligand matching on graft survival was observed in cadaver kidney transplants. Our results indicate that KIR ligand matching cannot be recommended as a strategy for improving renal allograft survival.

Graft Survival↗

PubMed2003

Patient with Kabuki syndrome and acute leukemia.

Kabuki syndrome is a multiple congenital anomaly/mental retardation syndrome which often involves recurrent infections. There is cumulative evidence of an immunodeficiency in Kabuki patients. We report a 2-year-old girl with typical Kabuki syndrome, who developed acute lymphocytic leukemia. The patient showed low levels of immunoglobulins G and A and a history of recurrent infections, that might indicate an immunodeficiency leading to an increased susceptibility to cancer. The girl was treated according to BFM protocols adapted to the patient's impaired cardiac situation and severe underweight. She achieved continual complete remission. Classical and molecular cytogenetic analyzes did not detect any abnormality.

Abnormalities, Multiple↗

PubMed2002

Matrix analysis for the dissection of interactions of G-protein beta3 subunit C825T genotype, allograft function, and posttransplant hypertension in kidney transplantation.

BACKGROUND: Complex relationships between genes and environment and the resulting biological impact have been dissected predominantly by conventional association studies. A major limitation of such studies results from the fact that only bidirectional investigations of genes and clinical end-points are commonly performed. The authors, therefore, applied matrix analyses to account for interactions between genetic and environmental factors influencing kidney allograft function. METHODS: By using matrices of correlation coefficients we tested the genetic effect of a variant within the gene encoding the beta3-subunit of heterotrimeric G-proteins (Gbeta3-C825T polymorphism) on posttransplant hypertension and kidney allograft function. This strategy allowed the authors to account for the influence of additional well-established genetic, clinical, and environmental confounders. The authors studied 281 consecutive white kidney recipients recruited between 1988 and 1993. Correlation coefficients of indices of relative change (percent) of systolic blood pressure (BP) and creatinine clearance (CrCl) were used in correlation coefficient matrices to elucidate interactions of parametrical biological parameters with environmental and genetic risk factors. RESULTS: A significant relationship was found between decreasing CrCl and increasing systolic BP in only those recipients who carried the Gbeta3-825TT genotype and did not lose graft during the first 3 years (R2 = 0.25; P = 0.021). CONCLUSIONS: In transplant recipients who did not lose their graft during the first 3 years after transplantation, the Gbeta3-TT genotype contributed to accelerated loss of allograft function by exaggeration of posttransplant hypertension. This relationship could only be elucidated by means of matrix analyses that allow the detection of complex relations between clinical, genetic, and environmental factors.

Adult↗

PubMedDate not supplied

Olfactory learning in individually assayed Drosophila larvae.

Insect and mammalian olfactory systems are strikingly similar. Therefore, Drosophila can be used as a simple model for olfaction and olfactory learning. The brain of adult Drosophila, however, is still complex. We therefore chose to work on the larva with its yet simpler but adult-like olfactory system and provide evidence for olfactory learning in individually assayed Drosophila larvae. We developed a differential conditioning paradigm in which odorants are paired with positive ("+" fructose) or negative ("-" quinine or sodium chloride) gustatory reinforcers. Test performance of individuals from two treatment conditions is compared-one received odorant A with the positive reinforcer and odorant B with a negative reinforcer (A+/B-); animals from the other treatment condition were trained reciprocally (A-/B+). During test, differences in choice between A and B of individuals having undergone either A+/B- or A-/B+ training therefore indicate associative learning. We provide such evidence for both combinations of reinforcers; this was replicable across repetitions, laboratories, and experimenters. We further show that breaks improve performance, in accord with basic principles of associative learning. The present individual assay will facilitate electrophysiological studies, which necessarily use individuals. As such approaches are established for the larval neuromuscular synapse, but not in adults, an individual larval learning paradigm will serve to link behavioral levels of analysis to synaptic physiology.

Animals↗

PubMedDate not supplied

Treatment of essential thrombocythemia in childhood.

Essential thrombocythemia is a rare myeloproliferative disorder in childhood. For symptomatic patients with platelet counts greater than 1000 x 10(9)/L, cytoreductive treatment is recommended. The authors describe a 5-year-old boy with symptomatic essential thrombocythemia who was treated with anagrelide (Agrylin) for 23 months. He responded well but early on developed anemia. Because anagrelide is thought to specifically inhibit thrombopoesis, anemia is assumed to be a rather rare and late adverse effect. Its early occurence in this patient might indicate an increased vulnerability to anagrelide (Agrylin) in young children.

Anemia↗