The age-1 and daf-2 genes function in a common pathway to control the lifespan of Caenorhabditis elegans.

Recessive mutations in two genes, daf-2 and age-1, extend the lifespan of Caenorhabditis elegans significantly. The daf-2 gene also regulates formation of an alternative developmental state called the dauer. Here we asked whether these two genes function in the same or different lifespan pathways.

Iron overload in African Americans.

Purpose: Iron overload unexplained by dietary or medicinal iron excess, transfusion, or sideroblastic anemia has been described infrequently in Americans of African descent. The purpose of this study was to characterize iron overload attributable to excessive iron absorption in African Americans.

Patients And Methods: In a community hematology and medical oncology practice during the interval 1990 to 1993, we identified and evaluated a series of cases comprised of 6 men and 1 woman, with a mean age of 55 +/- 14 (SD) years (range 33 to 69).

Utility of posttransplantation panel-reactive antibody measurements for the prediction of rejection frequency and survival of heart transplant recipients.

Background And Methods: Seventy-six heart transplants in 73 patients were studied for the formation of lymphocytotoxic panel-reactive antibodies after transplantation. Treatment of patient serum with dithioerythritol was used to discriminate between antibodies of the immunoglobulin M and immunoglobulin G isotypes. Human leukocyte antigen specificities of immunoglobulin G panel reactive antibodies were determined by the pattern of reactivity with the cell panel used in the panel-reactive antibodies determinations.

Sequences required for paramutation of the maize b gene map to a region containing the promoter and upstream sequences.

The b gene encodes a transcriptional regulator of the maize anthocyanin biosynthetic pathway. Certain b alleles participate in paramutation, an allele-specific interaction that heritably alters transcription. The moderately transcribed B' allele heritably reduces the transcription of the highly transcribed B-I allele in a B'/B-I heterozygote, such that the B-I allele becomes B'.

A rapid flow cytometry assay for HLA antibody detection using a pooled cell panel covering 14 serological crossreacting groups.

Many studies have demonstrated the usefulness of flow cytometry crossmatching (FC-XM) for selection of regraft recipients, and more recently this assay has been shown to correlate with allograft survival in primary cadaveric transplant patients. The need now exists for a practical antibody screening procedure which uses the same methodology. We describe here a simple and sensitive method to screen for HLA antibodies by FC using a pool of 6 cells selected to cover the 14 serological crossreacting groups defined by Rodey.