Sequential monitoring of peripheral blood lymphocyte subsets in rats.

The methodology of enumeration of T cell subsets in humans is well established and has widespread clinical application. Sequential monitoring of lymphocyte subsets in small animals requires a consistent and reliable methodology for staining and enumerating lymphocyte populations. The optimal conditions for enumerating subclasses of rat peripheral blood lymphocytes with the Spectrum III flow cytometer are described.

An analysis of tissue-specific transplantation phenomena in a minor histoincompatibility system.

Tissue-specific differences in immunogenicity were demonstrated following allotransplantation across the same minor histocompatibility barrier (BALB/c----DBA/2). In contrast to the high immunogenicity of fetal pancreas and skin, isolated islets, fetal proislets, and thyroid were weakly immunogenic. These tissue-specific effects were not related to the presence of tissue-specific antigens or the absence of recognizable minor alloantigens from the less immunogenic tissues.

Evidence for titratable gating charges controlling the voltage dependence of the outer mitochondrial membrane channel, VDAC.

A voltage-dependent anion-selective channel, VDAC, is found in outer mitochondrial membranes. VDAC's conductance is known to decrease as the transmembrane voltage is increased in either the positive or negative direction. Charged groups on the channel may be responsible for this voltage dependence by allowing the channel to respond to an applied electric field.

Cultured thyroid allografts induce a state of partial tolerance in adult recipient mice.

Thyroid allografts (BALB/c) prepared for transplantation by cyclophosphamide pretreatment of the donor, followed by organ culture of donor tissues for 3 weeks in a gas phase of 95% O2-5% CO2 function in normal CBA recipient mice for greater than or equal to 350 days. Up to 100 days post-transplantation, the tissue can be rejected by challenge of the recipient with 10(5) BALB/c peritoneal cells. After prolonged residence in the recipient (greater than 100, less than or equal to 350 days), only a proportion of allografts are rejected when the recipient is challenged with 10(5) followed by 10(6) peritoneal cells of donor origin.

The reversal of diabetes by pancreatic islet transplantation.

In this paper the theoretical basis of alloreactivity and its relevance to transplantation biology is discussed prior to a review of work showing that culture of adult mouse pancreatic islets for 7 days in 95% O2 and 5% CO2 facilitates successful grafting to nonimmunosuppressed allogeneic recipients. These allografts function by reversing both chemically induced and spontaneous diabetes. The fetal mouse pancreas is more immunogenic than adult islets, and even after a culture period of 10 days in 95% O2 and 5% CO2, BALB/c allografts are consistently rejected by nonimmunosuppressed recipient mice.

Reversal of diabetes by allogenic islet transplantation without immunosuppression.

Streptozotocin-induced diabetes is temporarily reversed following the allo-transplantation of BALB/c (H-2d) islet tissue to normal CBA (H-2k) recipients, but by 2-4 week post-transplantation these animals return to their initial diabetic condition. Organ culture of allogeneic islet tissue in 95% O2 and 5% CO2 for 7 days prior to transplantation reduces the immunogenicity of the tissue, and cultured allografts give prolonged (greater than 110 days) reversal of diabetes in normal allogeneic recipients. The non-fasting blood sugar level remains in or very close to the normal range, urine glucose output is one to two orders of magnitude less than that of diabetic control animals and allografted animals regain their pre-morbid body weight within 60 days of transplantation.

Modulation of tissue immunogenicity by organ culture. Comparison of adult islets and fetal pancreas.

Uncultured mouse islet allografts (BALB/c to CBA) are rejected 2 to 4 weeks after transplantation. Allografts, cultured in 95% O2 and 5% CO2 for 7 days before transplantation, show no sign of rejection up to 3 months post-transplantation. However, the cultured allografts are rejected if the CBA recipient is given an i.

H-2 complex and Ia antigens on cells dissociated from mouse thyroid glands and islets of Langerhans.

Mouse thyroid tissue was dissociated with collagenase, fixed in periodate-lysine-paraformaldehyde (PLP), and further dissociated with EDTA and trypsin to yield cell suspensions containing mainly follicle epithelial cells and vascular endothelial cells. H-2 complex antigens were detected on the vascular endothelial cells at about the same high density as on peritoneal macrophages, and at a lower concentration on the laterobasal membranes of follicle epithelial cells. Neither of these cell types expressed detectable Ia antigens, but a minor cell type was presented that showed dense expression of Ia antigens.

Cellular changes in cultured mouse thyroid glands and islets of Langerhans.

Islets of Langerhans cultured 7 days in vitro no longer contained any capillary endothelial cells, but their endocrine cells remained ultrastructurally normal up to 14 days. Vascular endothelial cells were also lost from cultured thyroid lobes, but more slowly. Thyroid endothelium was readily identified after 7 days of culture, although many cells appeared to be degenerating, and a few degenerating endothelial cells were still present after 14 days in culture.

The effects of delayed and displaced visual feedback on motor control.

Developments in television technology have made possible new approaches to the study of the role of visual feedback in motor control. In two experiments using a special videodisc recording and playback system, the effects of delaying for 66 msec a subject's view of his own hand during a target-directed movement was investigated. The observed effects of such visually delayed feedback compared to spatially distorted feedback produced by prisms led to three major conclusions: (a) despite the behavioral similarity (overshooting) induced by the two kinds of altered feedback, the role of each in the visual-motor control loop is different; (b) adaptation to and the after effect of the two kinds of altered feedback are based on different control mechanisms (c) the processing and use of visual information in hand control requires less time than previous experiments have indicated.

Apparent insulin resistance due to abnormal enzymatic insulin degradation: a new mechanism for insulin resistance.

A 16-year-old girl presented with severe, prolonged insulin resistance. Insulin antibodies, initially thought to be responsible for the insulin resistance, were suppressed using monocomponent insulin and immunosuppressive therapy; however insulin resistance persisted. Insulin kinetic studies suggested abnormal metabolism of a bolus injection of 125I insulin and the reappearance in the circulation of radioactive products, demonstrated by chromatography to be of different molecular weight to insulin.

Successful allotransplantation of mouse pancreatic islets to nonimmunosuppressed recipients.

Pancreatic islets from BALB/c (H-2d) mice are rejected within 14 days of transplantation to the kidney capsule of allogeneic, CBA/H (H-2k) recipients. Cyclophosphamide pretreatment of the islet donor reduced the intensity of the allograft response, and these islets undergo a more chronic rejection process. Islets from cyclophosphamide-pretreated donors can be cultured in a gas phase of 95% O2 and 5% CO2, provided the islets are aggregated into clusters of about 50 islets.

Integrated concentrations of prolactin in breast-feeding mothers.

Mean 24-hour integrated concentrations of serum prolactin (PRL) in 8 breast-feeding mothers (62 +/- 10.4 microgram/l) was significantly higher than in 4 control subjects (14.8 +/- 3.