Oxidative metabolic responses of rabbit pulmonary alveolar macrophages

During phagocytosis of opsonized lipopolysaccharide-coated paraffin oil droplets, rabbit alveolar macrophages reduced nitroblue tetrazolium, which effect was in part inhibitable with the use of superoxide dismutase. Exposure of cytochalasin-B-treated rabbit alveolar macrophages to opsonized zymosan led to the generation of superoxide, as quantitated by ferricytochrome C reduction. It was found that nitroblue tetrazolium in the presence of ferricytochrome C could in turn serve as scavenger of superoxide during stimulation of cytochalasin-B-treated rabbit alveolar macrophages. Following challenge with either opsonized zymosan or the membrane perturbant digitonin, rabbit alveolar macrophages released hydrogen peroxide into the extracellular medium. Employment of the surface membrane stimulant phorbol myristrate acetate led to activation of the hexose monophosphate shunt, which activity could be further enhanced in the presence of superoxide dismutase or attenuated in the presence of catalase. These studies demonstrate that rabbit alveolar macrophages release superoxide and hydrogen peroxide during surface membrane perturbation. In turn, hydrogen peroxide generation can stimulate the hexose monophosphate shunt.     

Lysis of colonic epithelial cells by allogeneic mononuclear and lymphokine activated killer cells derived from peripheral blood and intestinal mucosa: evidence against a pathogenic role in inflammatory bowel disease.

A sensitive 4 h 51Cr-release cytotoxicity assay has been developed using as targets colonic epithelial cells obtained by Dispase-collagenase digestion of resected mucosa or colonoscopic biopsies. Peripheral blood mononuclear cells (MNC) from most healthy donors showed low, but significant levels of cytotoxicity for normal epithelial cell target cells of 8.7 (4.4) % (mean (SD] and similar levels were found in 14 ulcerative colitis (6.5 (4.4) %) and 16 Crohn's disease (6.2 (5.2) %) patients. Neither drug therapy nor disease activity influenced the results. The sensitivity of colonic epithelial cells isolated from inflamed and histologically normal mucosa to lysis by peripheral blood MNC from a single donor was not affected by the underlying disease. Anti-epithelial cell activity did not correlate with anti-K562 activity and the cytotoxic cell was plastic non-adherent and Leu-11b-. None of 15 MNC populations isolated from mucosa of normal, tumour bearing, or chronically inflamed intestine exhibited significant lysis of colonic epithelial cells despite killing of K562 target cells in 10. Lymphokine activated killer (LAK) cells, generated by interleukin-2 stimulation in vitro of nine intestinal and seven peripheral blood MNC populations, exhibited high levels of lysis of K562 cells but, on every occasion, failed to lyse colonic epithelial cells. These data indicate that spontaneously cytotoxic or LAK cells are unlikely to play a role in the generation of colonic epithelial cell injury by direct cytotoxicity in inflammatory bowel disease.     

Speech audiometry in Estonia: Estonian words in noise (EWIN) test

Objective: Currently, there is no up-to-date speech perception test available in the Estonian language that may be used to diagnose hearing loss and quantify speech intelligibility. Therefore, based on the example of the Nederlandse Vereniging voor Audiologie (NVA)-lists (Bosman, 1989 Bosman A.J. 1989. Speech Perception by the Hearing Impaired. Doctoral dissertation, University of Utrecht. [Google Scholar]; Wouters et al, 1994 Wouters J., Damman W. &; Bosman A.J. 1994. Vlaamse opname van woordenlijsten voor spraakaudiometrie. Logopedie, 6, 28–33. [Google Scholar]) an Estonian words in noise (EWIN) test has been developed. Design: Two experimental steps were carried out: (1) selection and perceptual optimization of the monosyllables, and (2) construction of 14 lists and an evaluation in normal hearing (NH) subjects both in noise and in quiet. Study sample: Thirty-six normal-hearing (NH) native speakers of Estonia (age range from 17 to 46 years). Results: The reference psychometric curve for NH subjects was determined, with the slope and speech reception threshold being well in accordance with the respective values of the NVA lists. The 14 lists in noise yielded equivalent scores with high precision. Conclusion: The EWIN test is a reliable and valid speech intelligibility test, and is the first of its kind in the Estonian language.     

Identification and culture of Kaposi's sarcoma-like spindle cells from the peripheral blood of human immunodeficiency virus-1-infected individuals and normal controls [see comments]

We examined 26 patients with human immunodeficiency virus-1 (HIV-1)- associated Kaposi's sarcoma (KS), and 76 HIV-1-infected (HIV-1+) people without KS or uninfected (HIV-1-) controls for the presence of circulating KS-like spindle cells. Adherent cells that had spindle morphology and several characteristics of spindle cells of KS lesions (KS cells) were identified in the peripheral blood mononuclear cell fraction only after culture in the presence of conditioned medium (CM) from activated lymphocytes. The peripheral blood-derived spindle cells (PBsc) expressed a variety of endothelial cell markers, such as Ulex europaeus I lectin, EN4, EN2/3, EN7/44, CD13, CD34, CD36, CD54, ELAM-1, and HLA-DR. However, they were negative for CD2, CD19, PaIE, and factor VIII-related antigen. The PBsc produced angiogenic factors as evidenced by the ability of CM from these cells to promote growth of normal vascular endothelial cells. In addition, subcutaneously injected PBsc stimulated angiogenesis in vivo in athymic nude mice. We determined that the number of PBsc grown from the peripheral blood of HIV-1+ patients with KS or at high risk to develop KS were increased by 78- fold (P = .0001) and 18-fold (P = .005), respectively, when compared with HIV-1- controls. The number of spindle cells cultured from the HIV- 1+ patients at low risk for developing KS, eg, HIV-1+ injection drug users, showed no statistical increase when compared with HIV-1- controls. The presence of increased PBsc with characteristics of KS cells in HIV-1+ KS patients or patients at high risk for developing KS gives insights into the origin of KS cells and may explain the multifocal nature of the disease. In addition, this may be useful in predicting the risk of KS development.