Radiation-induced proctosigmoiditis

In a prospective study, 37 consecutive patients with radiation-induced proctosigmoiditis were randomized to receive a four-week course of either 3.0 g oral sulfasalazine plus 20 mg twice daily rectal prednisolone enemas (group I, N = 18) or 2.0 g twice daily rectal sucralfate enemas plus oral placebo (group II, N = 19). The two groups were comparable with respect to demographic features, duration of symptoms, and clinical and endoscopic staging of the disease. Fifteen patients in group I and 17 in group II completed the trial. At four weeks, both groups showed significant clinical improvement (P less than 0.01 for group I and P less than 0.001 for group II) and endoscopic healing (P less than 0.01 for group I and P less than 0.001 for group II). When the two groups were compared, sucralfate enemas showed a significantly better response as assessed clinically (P less than 0.05), although endoscopically the response was not statistically different (P greater than 0.05). We conclude that both treatment regimens are effective in the management of radiation proctitis. Sucralfate enemas give a better clinical response, are tolerated better, and because of the lower cost should be the preferred mode of short-term treatment.     

A new human B-lymphocyte surface antigen (BL 2) detectable by a hybridoma monoclonal antibody: distribution on benign and malignant lymphoid cells

A hybridoma-derived monoclonal antibody, produced by immunization with the Burkitt's tumor-derived B-lymphoblastoid cell line, B35M, was previously shown to detect a 68,000 dalton surface membrane protein, BL2, on the surface of peripheral blood B cells, which is absent from thymocytes, T cells, and granulocytes. In this study, we investigated the expression and distribution of BL2 on benign and malignant human lymphoid cells. Indirect immunofluorescent assay with this monoclonal antibody demonstrated that BL2 is expressed by cells within the fetal liver and by a variable proportion of lymph node, tonsil, and spleen B cells, but not by T cells. The neoplastic cells isolated from 18 T-cell malignancies were BL2- . BL2 was was heterogeneously expressed by a variable proportion of the malignant cells in 29/32 cases of B-chronic lymphocytic leukemia and 33/38 cases of B-cell lymphomas, but appeared to be lost in the terminal stages of B-cell differentiation, as myeloma plasma cells were BL2- . BL2 expression was not limited to B cells of a particular surface immunoglobulin isotype. Immunofluorescent staining for BL2 in cryostat tissue sections demonstrated that the majority, but not all, germinal center and interfollicular Ia+ (non-T) cells are BL2+. These findings suggest that BL2 is a B-cell lineage-specific differentiation marker that may be useful in the study of B-cell ontogeny and in defining subgroups of the B-cell malignancies.     

Prostacyclin production by perturbed bovine aortic endothelial cells in culture

This study reports that endotoxin (Escherichia coli serotype 026:B6) and 12-O-tetradecanoyl-phorbol-13-acetate stimulate cultured bovine aortic endothelial cells to generate prostacyclin. The prostacyclin concentration of the culture medium was measured indirectly by radioimmunoassay for 6-keto-PGF1 alpha. The amount of prostacyclin generated depended on the concentration of endotoxin or phorbol diester. Prostacyclin generation was not immediate, but occurred slowly after a six-hour lag period. The perturbed cells contracted and showed marked shape changes that correlated temporally with the start of enhanced prostacyclin production. Cytochalasins B and D, vinblastine, and colchicine inhibited prostacyclin production, indicating involvement of the cytoskeleton in the cellular response to endotoxin and phorbol diester. The increase in prostacyclin production was prevented by trifluoperazine, an inhibitor of the Ca++-calmodulin system, which is known to be involved in cytoskeletal function. Generation of prostacyclin was inhibited by cycloheximide and actinomycin D, indicating dependence on protein and ribonucleic acid synthesis. It is postulated that exposure to endotoxin or phorbol diester leads, via a series of reactions that involve RNA and protein synthesis and require intact cytoskeletal function, to the generation of toxic active intermediate(s) that stimulate the enzymes necessary for prostacyclin production.     

Effect of repeated boluses of intravenous omeprazole and primed infusions of ranitidine on 24-hour intragastric pH in healthy human subjects

The aim of this study was to identify dosage regimens using intravenous omeprazole and ranitidine that would elevate and consistently maintain intragastric pH>6 in the first 24 hr of therapy. In 19 healthy, fasting human subjects using continuous 24-hr gastric pH-metry, we studied two dosages of primed infusions of ranitidine (50 mg bolus followed by infusion of either 3 or 6 mg/kg body wt/24 hr) and six regimens of intravenous omeprazole (80–200 mg in 24 hr in two to five boluses). Only the two ranitidine infusions and high doses of omeprazole (≥160 mg/day as four or five boluses) raised the intragastric median pH above 5.4. There was no significant difference in the median intragastric pH after high dose ranitidine and high doses of omeprazole. Considerable interindividual variation in intragastric pH was observed after omeprazole therapy. The percentage of intragastric pH>6.0 during the 24-hr study was lower after omeprazole (35–42%) than after high-dose ranitidine (58%). We conclude that it is possible to raise intragastric pH>6.0 by use of either primed ranitidine infusion or by repeated boluses of omeprazole. However, maintenance of this high pH in the first 24 hr is difficult with both, more so with omeprazole.     

Symptomatic biliary obstruction associated with juxtapapillary duodenal diverticulum

Summary We describe a 56-year-old woman with symptomatic biliary obstruction associated with a duodenal diverticulum. Cholangiography revealed a dilated common bile duct with prominent distal obstruction of unusual configuration. Liver function tests were normal. Pain has not recurred since choledochojejunostomy.     

A defect in the oxidative metabolism of human polymorphonuclear leukocytes that remain in circulation early in hemodialysis

Human granulocytes harvested from uremic volunteers 15 min after the initiation of dialysis (at the nadir of neutropenia) were compared to predialysis controls. These intradialysis cells had a significant defect in peak luminol-enhanced chemiluminescence in response to opsonized zymosan, f-Met-Leu-Phe, and phorbol myristate acetate relative to predialysis control cells from the same patients. This defect could not be explained by a decrease in PMN myeloperoxidase concentration. H2O2 secretion by intradialysis cells (2 patients) was also depressed relative to predialysis controls. The ability to perform an independent function, orientation (polarization), was normal in both pre- and intradialysis cells relative to control. Whereas 125I-labeled formyl peptide binding studies demonstrated identical values for affinity and receptor number for predialysis and normal control cells, intradialysis cells displayed a 27% decrease in receptor number. This decrease in available receptor number. This decrease in available receptors may be related to the decreased chemiluminescence observed in response to f-Met-Leu-Phe. Furthermore, the results are consistent with the hypothesis that a defective PMN population remains in the circulation during the neutropenia of hemodialysis.     

Improved exercise performance after exchange transfusion in subjects with sickle cell anemia

Ten patients with sickle cell anemia underwent partial exchange transfusion with hemoglobin-A-containing cells using a technique that allowed hemoglobin concentration and blood volume to remain constant. The mean fraction of hemoglobin-A in these patients increased from 9% to 55%, but the mean hemoglobin concentration increased by only 1.44 g/dl. The exchange resulted in a large improvement in submaximal exercise capacity: the mean of the anaerobic threshold (the work at which lactic acid begins to accumulate in the blood) increased from 68 to 114 W. The mean work performed at a heart rate of 170/min, an estimation of maximal work capacity, increased from 128 to 187 W. Improved exercise performance after partial exchange transfusion may result from the superior flow properties of hemoglobin-A-containing red cells. Furthermore, we believe that exercise testing in sickle cell anemia has great potential utility as a means to monitor therapy and to evaluate the benefits of exchange transfusion.     

Analysis of the origin of marrow cells in bone marrow transplant recipients using a Y-chromosome-specific in situ hybridization assay

A Y-chromosome-specific in situ hybridization assay was used to assess the frequency with which host bone marrow cells are retained after marrow grafting. The majority of patients (74%) showed the presence of both host and donor marrow cells when assayed 14 days after transplant. By 84 days posttransplant only 4% of the patients retained host marrow cells. Only 1 of 19 evaluable patients analyzed over 1 year posttransplant showed minimal retention of host cells. No statistical correlation was found between retention of host cells posttransplant and the development of relapse or acute or chronic graft-versus-host disease. Pretransplant conditioning regimen, HLA-matching, diagnosis, disease status at transplant, ABO-matching, and patient age also showed no correlation with the retention of host cells posttransplant.