An antibody that facilitates hematopoietic engraftment recognizes CD44

Pretreatment of recipients with the monoclonal antibody (MoAb) S5 facilitates engraftment of bone marrow from mismatched, unrelated donors in the canine transplantation model. In the direct comparisons reported here, the S5 glycoprotein (gp) was found to have structural homology to CD44 that in humans has been implicated in adhesive interactions of one type of effector cell, the lymphocyte. The S5 antigen and gp90Hermes-1 exhibited codistribution on canine peripheral blood cells. Both S5 and Hermes-1 (anti-CD44) MoAbs recognized 90-Kd species in radioimmune precipitations of 125I surface-labeled canine peripheral blood lymphocytes and bone marrow cells. Competitive antibody binding experiments showed that the epitope detected by S5 was distinct from that bound by Hermes-1 but overlapped with those defined by two other known anti-CD44 reagents, IM7 and Hutch-1. Sequential immunoprecipitation with S5 and Hermes-1 indicated that the two antibodies recognize the same or overlapping subsets of membrane gps. Tryptic digestion of S5 and anti-CD44 immunoprecipitates generated two major iodinated peptides of 27 and 35 Kd in both cases, a further indication of structural homology. Similarly, after N-glycanase digestion, S5 and CD44 immunoprecipitates were resolved to a single 68- Kd species. These findings suggest that CD44-mediated adhesive events may affect the fate of transplanted hematopoietic cells. The previous implications of this gp in T-lymphocyte activation and lymphocyte adhesion to endothelium thus provide useful paradigms to analyze its function in the bone marrow transplant setting.     

Objective measurement of limb perfusion by dermal fluorometry. A criterion for healing of below-knee amputation

Quantitative fluorometry has been recommended as an accurate adjunct to clinical judgment in the preoperative assessment of lower-extremity amputation level. In this prospective study of 56 patients who had below-knee amputation, clinical judgment was used as the sole criterion for site selection. Quantitative fluorometry was compared with clinical judgment in a prospective, blinded study. All patients were studied before amputation with administration of intravenous fluorescein. Fifteen minutes after injection, objective measurement of dye fluorescence was performed at multiple sites with a quantitative fluorometer, and a dye fluorescence index was derived. All limbs undergoing amputation were ischemic, manifested by rest pain, nonhealing ulcers, or gangrene. Five patients (8.7%) failed to heal at the below-knee level. The mean dye fluorescence index for the group that healed was 81 +/- 51 (range, 13 to 259) and for the group that failed to heal, 110 +/- 49 (range, 70 to 195). Objective measurement of fluorescein perfusion did not correlate with amputation healing at the below-knee level in our patient population.     

Significance of levels of specific immunoglobulins to DNA in SLE patients' sera detected by solid phase radioimmunoassay.

A solid phase radioimmunoassay was developed for detecting the quantity of double-stranded and single-stranded DNA antibodies in patients with systemic lupus erythematosus and other connective tissue diseases. The assay system employs a solid support 96-well, flex-vinyl microtiter plate to which bovine methyl albumin is layered, followed by denatured or native calf thymus DNA. A 1:80 dilution of patients' sera was added to respective wells followed by tritiated high affinity anti-IgG, -IgA, or IgM. Denatured DNA (single-stranded DNA) bound to methylated bovine serum albumin had less than 5% reannealment to the double-stranded form and provided a better substrate for Ab binding than double-stranded DNA, producing a linear binding curve. Of 58 patients diagnosed as having systemic lupus erythematosus (SLE), only 11 having active SLE had IgG antibody levels of greater than 5.0 microgram/ml to single-strand DNA. Renal involvement of some degree was found in all 11 with the high concentrations of IgG antibodies to DNA correlating with severe involvement. Patients with IgM antibodies to DNA alone had more benign types of SLE with little renal involvement. No abnormal levels of IgA Ab to either single-strand DNA or double-strand DNA were found in SLE patients' sera. Corticosteroid and/or immunosuppressant treatment caused a marked drop in the IgM Ab level to DNA within 10 days while IgG Ab to DNA remained high for up to 30 days. Quantitation of IgG and IgM Ab to single-strand DNA provides a useful method for diagnosing severe SLE with possible renal involvement and monitoring the course of the disease during therapy.     

Prevalence of human immunodeficiency virus infection, risk behavior, and HIV knowledge among tuberculosis patients in Afghanistan

OBJECTIVES/GOAL: To assess prevalence and correlates of human immunodeficiency virus (HIV) infection, risk factors, and HIV knowledge among tuberculosis patients in Afghanistan. STUDY DESIGN: Adult participants undergoing treatment for tuberculosis in this cross-sectional study completed a questionnaire and HIV testing between November 2005 and February 2006. Prevalence of HIV and high-risk behaviors were calculated, with correlates of high-risk behavior and relevant knowledge assessed. RESULTS: Of 1163 participants, 2 (0.2%, 95% CI: 0.0-0.6) were HIV-infected. Known risk factors for HIV infection, such as paying women for sex or male to male sexual contact, were rarely reported, though receipt of injections from a nonmedical provider was common (38%). Symptoms suspicious for sexually transmitted infection were reported by 5% of the population and were significantly associated with young (<26 years) age (OR: 3.2, 95% CI: 1.7-6.0). Relatively, a few participants had ever heard of HIV (23%) or condoms (25%). Condom use was significantly more frequent among those 26 and older (OR: 2.9, 95% CI: 1.7-5.2) and among male participants (OR: 1.5, 95% CI: 1.0-2.2). CONCLUSIONS: HIV prevalence among tuberculosis patients in Afghanistan is currently quite low. However, lack of knowledge of HIV and engaging in high-risk practices, particularly regarding health, make this group vulnerable. Health education sessions regarding HIV, sexually transmitted infection, and blood-borne infections should be implemented for tuberculosis patients during the treatment course.