Build-up with Antigen Absorption Test

An antigen absorption test using anti-A serum and A substance is described.
Using a build-up technique with the antigen absorption test, visual agglutination of formerly inagglutinable A cells, including a mixed-field appearance, has been obtained by both anti-A sera of human origin and Dolichos biflorus extract.

Résumé

Les auteurs décrivent un test d'absorption d'antigènes dans lequel ils ont utilisé un sérum anti-A et de la substance A.
Pour pratiquer ce test d'absorption, ils ont mis au point une technique basée sur le principe des réactions en chaîne grâce à laquelle ils ont pu obtenir avec des sérums anti-A d'origine humaine et un extrait de dolichos biflorus des agglutinations, présentant souvent l'image de l'agglutination mixte, d'érythrocytes A initialement inagglutinables.

Zusammenfassung

Es wird ein Antigen-Absorptionstest mit Anti-A-Serum und A-Gruppensubstanz beschrieben. Dieser Test wurde verwendet, um mit einer Mehrphasentechnik nicht agglutinierbare A-Zellen zu agglutinieren. Dies gelang sowohl mit menschlichen Anti-A-Seren als auch mit Dolichos-biflorus-Extrakten, wobei Mischzellbilder beobachtet wurden.     

Regulation of appetite and cholecystokinin secretion in anorexia nervosa.

Six patients with anorexia nervosa, the same patients after weight normalization, and six healthy control subjects had similar fasting and postprandial plasma cholecystokinin concentrations. These data do not support the hypothesis that low levels of hunger and food intake in anorexic patients reflect hypersecretion of this endogenous hormone, which is thought to inhibit hunger, promote satiety, and reduce feeding.     

Differential regulation of T helper phenotype development by interleukins 4 and 10 in an alpha beta T-cell-receptor transgenic system.

To address the mechanisms controlling T helper (Th) phenotype development, we used DO10, a transgenic mouse line that expresses the alpha beta T-cell receptor from an ovalbumin-reactive T hybridoma, as a source of naive T cells that can be stimulated in vitro with ovalbumin peptide presented by defined antigen-presenting cells (APCs). We have examined the role of cytokines and APCs in the regulation of Th phenotype development. Interleukin 4 (IL-4) directs development toward the Th2 phenotype, stimulating IL-4 and silencing IL-2 and interferon gamma production in developing T cells. Splenic APCs direct development toward the Th1 phenotype when endogenous IL-10 is neutralized with anti-IL-10 antibody. The splenic APCs mediating these effects are probably macrophages or dendritic cells and not B cells, since IL-10 is incapable of affecting Th phenotype development when the B-cell hybridoma TA3 is used as the APC. These results suggest that early regulation of IL-4 and IL-10 in a developing immune response and the identity of the initiating APCs are critical in determining the Th phenotype of the developing T cells.     

Inhibition of Na/Ca exchange stimulates insulin release from isolated rat pancreatic islets

Summary— Na/Ca exchange was recently shown to regulate cytosolic free Ca²⁺ concentration ([Ca²⁺]_i) in the pancreatic B-cell. The aim of the present study was to provide direct evidence that inhibition of the activity of the exchange may also increase insulin release. In the presence of extracellular Na+, caffeine stimulated ⁴⁵Ca outflow but did not increase insulin release from islets perifused in the presence of 2.8 mM glucose. By contrast, in the absence of extracellular Na+, caffeine almost failed to increase ⁴⁵Ca outflow and reversibly stimulated insulin release despite the fact that the absence of extracellular Na+ per se reduced basal insulin release. Similar findings were observed in islets perifused at a higher glucose concentration (8.3 mM) except that, in the presence of extracellular Na+, caffeine more markedly increased ⁴⁵Ca outflow and stimulated insulin release. Our data provide direct evidence that inhibition of Na/Ca exchange with resulting blockade of Ca²⁺ outflow may increase insulin release from the pancreatic B-cell under suitable experimental conditions.     

Diazepam-binding inhibitor and corticotropin-releasing hormone in cerebrospinal fluid

Diazepam-binding inhibitor (DBI) is a neuromodulatory peptide for gamma-aminobutyric acid (GABA) neurotransmission. Cerebrospinal fluid (CSF) levels of DBI have been found to be elevated in depression. CSF levels of the peptide corticotropin-releasing hormone (CRH) have also been found to be elevated in depression. Therefore, we examined for a relationship between DBI and CRH in human CSF. We found significant positive correlations between CSF levels of DBI and CRH in depressed patients, pathological gamblers, and normal controls. These data, along with the elevated CSF levels of DBI in depression, suggest the possibility that DBI may have a role in coordinating responses to stress in humans in addition to its possible role in the pathophysiology of depression.     

A prospective study of symptomatic bacteremia following platelet transfusion and of its management

BACKGROUND: The danger of bacteremia due to contaminated platelets is not well known. There are also no established guidelines for the management of febrile reactions after platelet transfusion. STUDY DESIGN AND METHODS: To determine the risk of symptomatic bacteremia after platelet transfusion, 3584 platelet transfusions given to 161 patients after bone marrow transplantation were prospectively studied. Platelet bags were routinely refrigerated for 24 hours after transfusion. Septic work-up was initiated for a temperature rise of more than 2 degrees C above the pretransfusion value within 24 hours of platelet transfusion or a temperature rise of more than 1 degree C that was associated with chills and rigor. Diagnosis of bacteremia after platelet transfusion was made only when the pairs of isolates from the blood and the platelet bags were identical with respect to their biochemical profile, antibiotic sensitivity, serotyping, or ribotyping. RESULTS: Thirty-seven febrile reactions, as defined above, occurred. Bacteremia subsequent to platelet transfusion was diagnosed in 10 cases. There was a 27-percent chance (95% CI, 15–43%) that these febrile reactions represented bacteremia that resulted from platelet transfusion. For a subgroup of 19 patients with a temperature rise of more than 2 degrees C, the risk of bacteremia was 42 percent (95% CI, 23–64%). Septic shock occurred in 4 of the 10 bacteremic patients. A rapid diagnosis was possible because the involved bacteria were demonstrated by direct Gram stain of the samples taken from the platelet bags of all 10 patients. CONCLUSION: Significant febrile reactions after platelet transfusion are highly likely to be indicative of bacteremia. Routine retention of platelet bags for subsequent microbiologic study was useful in the investigation of these febrile reactions. Empiric antibiotic therapy is indicated.