USE OF I.M. RANITIDINE FOR THE PROPHYLAXIS OF ASPIRATION PNEUMONITIS IN OBSTETRICS

Twenty patients who underwent elective Caesarean section receivedranitidine 150 mg by mouth 8–14 h, and 50 mg i.m. 90 min,before surgery. Intraoperative gastric aspiration resulted incontents with a pH > 2.5 and volume < 25 ml in all patients(mean pH 6.5 (SD 0.8); mean volume 9.0 (SD 7.2) ml). Sixty patientsin labour, who received ranitidine 50 mg i.m. 6-hourly, underwentemergency surgery. Half of this group received, in addition,a single preinduction dose of either 15 or 30 ml of sodium citrate0.3 mol litre^-1. A further 30 patients who remained unmedicatedduring labour and required emergency surgery received a preinductiondose of 15 or 30 ml of sodium citrate 0.3 mol litre^-1 alone.Ranitidine medication resulted in a mean aspirated gastric volumeof 31.4 (26.6) ml and pH of 5.3 (2.1); five of 30 patients hada pH < 2.5. The addition of sodium citrate 0.3 mol litre^-1resulted in gastric pH > 2.5 in all patients and a mean gastricvolume of 43.2 (38.3) ml. The group who received only sodiumcitrate 0.3 mol litre^-1 had a mean pH of 5.3 (1.1) and a meanvolume 122.7 (98.2) ml.     

A Hemodynamically Responsive Antitachycardia System: Theoretical Bases for Design

Current antitachycardia systems such as the automatic implantable cardioverter/defibrillator (AICD), detect tachyarrhythmias primarily by sensing rate and thereby perform inadequately in differentiating hemodynamically stable from unstable arrhythmias. As a result, these devices may discharge during stable tachycardias (such as sinus tachycardia), causing discomfort to the patient and depleting the device's limited energy supply. If a parameter which could reflect the particular hemodynamic state of a tachycardia were incorporated into the sensing algorithm of these systems, function may be more hemodynamically precise and discharge specificity may be improved.     

Intrapartum Care of a Woman With Aortic Aneurysms

Advances in technology and complex care have enabled women with various health problems to become and remain pregnant. Consequently, health-care practitioners are seeing an increasing number of pregnant women who have aortic aneurysms. This case study describes the culturally sensitive intrapartum care of a Middle Eastern woman with ascending and descending aortic aneurysms.     

Chemical studies in host-virus interactions; some additional methods of determining nutritional requirements for virus multiplication

Omission of a single constituent from a chemically defined medium approximating the virus growth-promoting properties of broth affects virus production in infected bacteria. This may be estimated by the one-step growth technique and the course of desoxyribose nucleic acid synthesis. Nine amino acids and one purine have been shown to be important by these tests. A combination of all constituents observed to be important by the single supplement and single omission techniques has approximated the virus growth-promoting properties of broth. Certain anomalous results have been commented upon.     

T cell clones from a Sjögren's syndrome salivary gland biopsy produce high levels of IL-10

Sjögren''s syndrome (SS) is characterized by a focal periductal salivary gland infiltrate consisting mainly of T and B lymphocytes. Most of the T cells bear the memory of CD4⁺ Th-1-like phenotype and express high levels of class II, though CD8⁺ cells are also present. We have studied 17 labial salivary gland and 15 peripheral blood T cell clones from a patient with primary SS. The tissue clones were 71% CD8⁺ and 29% CD4⁺, and the peripheral blood-derived clones were 60% CD8⁺ and 40% CD4⁺. The CD4⁺ T cell clones from both the salivary gland and autologous peripheral blood were of the Th1 phenotype, in that they produced interferon-gamma (IFN-γ) and IL-2 but very little IL-4 after 24 h stimulation with phorbol myristate acetate and anti-CD3 antibody. The salivary gland-derived CD4⁺ clones produced 15 times more IL-10 (7·92 ng/ml) than peripheral blood-derived CD4⁺ clones (0·52 ng/ml, P≤0·02). The tissue CD8⁺ clones produced 1·2 times (P<0·04) more IFN-γ and CD4⁺ clones produced 3·5 times less IL-2 (P<0·02) than the respective PBM-derived clones. The accumulation of Th1-type cells producing high levels of IL-10 in the salivary gland suggests a specific immunoregulatory function at the site of inflammation in SS.     

Characterization of Monoclonal Antihuman-B-Cell Antibody BL13 as an Anti-C3d-Receptor (CR2) Antibody

BL13, a mouse monoclonal IgG1 antibody raised against human B cells, blocked the function of the C3d receptor (CR2) and bound with high affinity (5 X 10(8) L M-1) to CR2 on B lymphoma cells. Following capping with the second antibody, BL13 inhibited C3d-dependent rosette formation of Daudi and Raji cells and C3b-dependent CR2-mediated rosette formation with B lymphoma cells, but did not inhibit CR1-mediated rosettes between C3b-bearing cells and peripheral blood lymphocytes. Competitive binding experiments between biotinylated BL13 or anti-CR2 antibody HB-5 and unlabelled antibodies demonstrated that BL13 bound to an epitope that is distinct from that recognized by HB-5, and closely associated with that recognized by monoclonal antibody anti-B2. BL13 only reacted with some B cells and follicular dendritic cells in germinal centres in human lymph nodes, whereas HB-5 strongly reacted with circulating B cells and bound to most cells in the follicles. These results demonstrate the heterogeneity of antigenically defined CR2.