Abrogation of DTH response and mitogenic lectin- and alloantigen-induced activation of lymphocytes by calcium inhibitors TMB-8 and BAPTA-AM

In vitro treatment of mouse lymphocytes with an intracellular calcium chelator BAPTA-AM significantly decreased lectin Concanavalin-A (Con-A)-induced and mixed lymphocyte reaction (MLR) mediated, alloantigen-induced lymphocyte activation as indicated by decreased percentage of lymphoblasts among the BAPTA-treated lymphocytes. In vivo treatment of mice with intracellular Ca(2+) antagonist TMB-8 was found to substantially impair delayed type hypersensitivity (DTH; cell mediated immune) response, as indicated by decreased footpad swelling on tuberculin challenge of mice sensitized with BCG, after a single treatment with a low dose of 0.01mg of TMB-8 per mouse. Interestingly, a second injection of a higher dose of TMB-8 (0.1mg per mouse) resulted in very significant (p=0.001) abrogation of DTH as indicated by complete absence of swelling of foot pad after PPD challenge in BCG-primed treated mice. All mice in this group showed fully impaired DTH response. Lymphocytes of allosensitized mice gave a significantly higher (p<0.05) MLR response than the na?ve mice. However, a single treatment of allosensitized mice with 0.1mg TMB-8 resulted into a lower MLR response, comparable in magnitude to that of untreated na?ve mice.     

Acidic ATP activates lymphocyte outwardly rectifying chloride channels via a novel pathway

Using whole-cell patch-clamp techniques we found that ATP activated an outwardly rectifying current in Daudi human B lymphoma cells under acidic conditions. The substitution of Cl^– for gluconate^– shifted the reversal potential, while Cl^– channel blockers, 4,4-diisothiocyanostibene-2,2-disulfonic acid (DIDS) and 9-anthracene carboxylic acid (9-AC), blocked the current, indicating that ATP induces this current by activating the outwardly rectifying chloride channel (ORCC). The effect of ATP on ORCC was mimicked by ADP, but not by other P2 receptor agonists such as ATPS (a poorly hydrolyzable analog of ATP), 2,3-O-benzoyl-4-benzoyl-ATP (BzATP), and UTP. The ATP-induced ORCC current was completely blocked by 100 M suramin (a P2 receptor antagonist), and was partially blocked by 100 M pyridoxal-phosphate-6-azophenyl-2,4-disulfonic acid tetrasodium (PPADS), which is another P2 receptor antagonist. Neither inactivation of G proteins nor elimination of extracellular Ca²⁺ affected the ATP-induced current, indicating that G protein-coupled P2Y receptors and Ca²⁺-permeable P2X receptors are not involved. Based on the pharmacological profile and the fact that acidic conditions are required for ATP to activate the ORCC, we suggest that acidic ATP activates the lymphocyte ORCC via a novel pathway, which is not associated with any previously described purinergic receptors.     

Detection of <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> Antigens in Urinary Proteins of Tuberculosis Patients

A sensitive sandwich enzyme-linked immunosorbent assay (ELISA) that can detect up to 0.5 ng of culture filtrate proteins (CFPs) of Mycobacterium tuberculosis strain H37Ra is described. This detection system features several special characteristics: (i) the use of CFPs from the H37Ra strain of Mycobacterium tuberculosis to generate capture and detection antibodies in rabbits and mice, respectively; (ii) affinity purification of CFP-reactive antibodies and selection of the antibody preparations for best performance in the sandwich ELISA system; and (iii) the use of urine-derived protein preparations for antigen detection. The sandwich ELISA could detect up to 0.5 ng of CFPs of the H37Ra strain of Mycobacterium tuberculosis. The assay did not detect antigens of Escherichia coli, Candida albicans or Saccharomyces cerivisiae but efficiently detected CFP preparations from nine different clinical isolates of Mycobacterium tuberculosis. Significant variations, however, were noted in the relative efficacy of the assay to detect CFPs from different clinical isolates of Mycobacterium tuberculosis. The procedure was utilized for detecting tubercular antigens in urine samples from 29 patients with confirmed (sputum-positive) tuberculosis and from 25 healthy controls. Significant levels of antigen could be detected in 22 of the 29 samples tested. Electronic Publication     

Contraceptive use among South Asian women attending general practices in southwest London.

A cross-sectional survey of contraceptive practices was conducted among 180 South Asian women aged 16 to 50 years, attending inner-city general practices. Overall prevalence of contraceptive use was 63% and ranged from 70% in South Asian teenagers, to only 50% in women over 30 who had completed their family. Thirteen per cent of women had had a termination of pregnancy Although contraceptive use in this group is increasing, it has not yet reached national levels.     

Goblet cell carcinoids of the appendix: immunophenotype and ultrastructural study

BACKGROUND: Goblet cell carcinoids of the appendix are rare neoplasms with uncertain biological behavior. OBJECTIVE: The aims of our study were to evaluate the immunophenotype of this neoplasm with cell cycle/cell proliferation markers and to understand their histogenesis with ultrastructural analysis using conventional carcinoids as a frame of reference. METHODS: Clinical data and archival pathologic material of all goblet cell carcinoids of the appendix recorded by the Saskatchewan Cancer Registry between 1970 and 1998 were reviewed and evaluated by light microscopy, histochemistry, immunohistochemistry, and electron microscopy. RESULTS: Seven cases of goblet cell carcinoids were identified among 110 cases of conventional carcinoids of the appendix. Histopathology revealed widespread infiltration of the periappendiceal fat in all cases, with extensive perineural invasion. The cells stained strongly positive for mucicarmine, periodic acid-Schiff, periodic acid-Schiff diastase, Alcian blue, cytokeratin, and carcinoembryonic antigen. Most cases were positive for synaptophysin. Increased expression of cell proliferation markers and cell cycle markers was observed. Expression of p53 was strong in one case. Electron microscopy demonstrated the presence of mucinous vacuoles of varying sizes and occasional membrane-bound neuroendocrine granules. CONCLUSIONS: Goblet cell carcinoids of the appendix arise from a pluripotent cell with divergent neuroendocrine and mucinous differentiation. These neoplasms are widely invasive; they demonstrate a high cellular proliferation rate and dysregulation of the cell cycle with up-regulation of cyclin D1 and p21, and down-regulation of p16. Complete removal of the tumor is recommended because of the unpredictable biological behavior of this tumor, which includes delayed local recurrences and lung metastases.     

Storage of thawed cryoprecipitated AHF is better at room temperature than at 1 degree C to 6 degrees C for factor VIII content

Before November 1989, both the American Association of Blood Banks and the Food and Drug Administration required that thawed cryoprecipitated antihemophilic factor (AHF) should be used immediately or be stored at room temperature and administered within 6 hours. However, in November 1989, the American Association of Blood Banks changed the requirement for storage of thawed cryoprecipitated AHF from room temperature to 1 degree C to 6 degrees C, while the Food and Drug Administration still required thawed cryoprecipitated AHF to be stored at room temperature. The present study was designed to measure and compare the factor VIII activity in 10 bags of thawed cryoprecipitated AHF that were split into aliquots and stored at room temperature and at 1 degree C to 6 degrees C. At 6 and 24 hours after thawing, the mean factor VIII activities (% of normal) of the room temperature-stored cryoprecipitated AHF were 741% and 680% vs 650% and 608% for the 1 degree C- to 6 degrees C-stored cryoprecipitated AHF (P less than .05 at 6 hours and P = .11 at 24 hours). The storage of thawed cryoprecipitated AHF at 1 degree C to 6 degrees C also resulted in precipitation of both factor VIII and fibrinogen. These data show that it is better to store thawed cryoprecipitated AHF at room temperature vs 1 degree C to 6 degrees C for factor VIII activity. These data also suggest that adequate levels of factor VIII are maintained in thawed cryoprecipitated AHF that has been stored at room temperature for up to 24 hours.     

Racial differences in vitamin B12 levels in the United States

Studies from Africa have demonstrated that black people have higher vitamin B12 (cobalamin) levels than do white people. The authors compared healthy white people, black people, and Latin-Americans in the United States. Their study is also the largest in which the effect of race and sex on the cobalamin levels has been examined. Analysis of 233 healthy subjects showed that black people had significantly higher (P less than 0.0001) vitamin B12 levels than did white people. Latin-Americans had levels intermediate between those of white and black people, although their levels were significantly different only in comparison with white people (P = 0.0029). Based on the study of 305 healthy subjects, no sex difference in vitamin B12 levels was noted. Conflicting claims have been made on sex difference in the past. The authors conclude that there is a racial but not a sex difference in vitamin B12 levels in the United States. Like African black people, black people and Latin-Americans in this country have significantly higher vitamin B12 levels than do white people. This finding supports the thesis that genetic factors contribute to the racial differences in vitamin B12 levels.     

Development of enhanced blood flow responses to prostaglandin E1 in carrageenan-induced granulation tissue

The distribution of cardiac output (c.o.) was measured by the radioactive microsphere method in rats at different time intervals after the implantation of carrageenanimpregnated sponges. The amount of blood distributed to the developing granulomata increased from day 5 after sponge implantation to day 7, but showed no further increase at day 10. A similar pattern in blood flow was observed in the skin covering the granulomata. Injection of PGE₁ (100 ng) into the sponges led to an increase in blood flow, the magnitude of which became gradually larger between days 5 and 10. A similar, though less marked increase in sensitivity to PGE₁ was observed in the skin covering the granulomata, PGE₁ causing a significant increase in blood flow to the skin on day 10. These changes in sensitivity to exogenous PGE₁ may be due to decreasing levels of endogenous PGE and/or maturation of the newly formed blood vessels in the granulation tissue.     

N-myristoyltransferase: A potential novel diagnostic marker for colon cancer

Background  

Colon cancer is the second leading cause of cancer deaths in the western world. If detected early, colorectal cancer is one of the most treatable forms of cancer. Unfortunately, very few people are screened. N-myristoyltransferase (NMT) catalyzes myristoylation of various proteins including oncoproteins. We have demonstrated earlier the alteration of NMT activity during the progression of colorectal cancer and established NMT as a putative therapeutic target for cancer.     

Escherichia coli Isolated from Domestic Animals Pathogenic for Gnotobiotic Piglets

Three strains of Escherichia coli isolated from infectious processes in a calf, a dog, and a cat were examined for their capacity to produce disease or death, or both, in newborn gnotobiotic piglets. The O groups represented by these particular strains of E. coli were O4: (canine origin), O6: (feline origin), and O39: (bovine origin). All three isolates upon oral administration proved to be pathogenic. Infection with the E. coli O4: (canine) or O39: (bovine) consistently produced signs of enteric coli-bacillosis and death in all 1- and 3-day-old piglets within 24 to 48 hr. The O6: (feline) isolate, on the other hand, produced a marked polyserositis and generally required 6 to 7 days to kill a piglet. Only the respective type of E. coli used in the particular trial was recovered from the diseased piglets. These findings suggest the possible role of domestic animals and household pets in the spread of potentially pathogenic E. coli to other species.