Luminol chemiluminescence in rat macrophages and granulocytes: the role of NO, O2-/H2O2, and HOCl

Luminol chemiluminescence was increased up to five-fold by L-arginine and markedly inhibited by NG-nitro-L-arginine (L-NNA) in phorbol ester (PMA) or opsonized zymosan-activated rat Kupffer cells, and in PMA-activated rat peritoneal and alveolar macrophages. While in Kupffer cells these effects did occur without pretreatment with lipopolysaccharides (LPS), LPS pretreatment was a requirement in peritoneal and alveolar macrophages. Azide (0.05 mM) had no effect on luminol chemiluminescence in the macrophages. The changes in luminol chemiluminescence were accompanied by parallel changes in nitric oxide (NO) formation. Macrophage superoxide anion radical (O2-) production was not significantly changed by addition of L-arginine and L-NNA nor by pretreatment with LPS. No hypochlorous acid (HOCl) formation was detectable in the macrophages. In contrast, in rat granulocytes activated by a variety of stimuli including PMA, zymosan, the chemotactic peptide formyl-methionyl-leucyl-phenylalanine and the calcium ionophore A23187 with or without pretreatment with LPS, L-arginine and L-NNA had no effect on luminol chemiluminescence. Luminol chemiluminescence, however, was largely inhibited by 0.05 mM azide. The activated granulocytes released significant amounts of HOCl but did not generate NO. These results demonstrate that NO may largely contribute to luminol chemiluminescence in rat macrophages, in which HOCl formation does not occur. On the other hand, HOCl is the reactive oxygen species responsible for luminol chemiluminescence in rat granulocytes, where NO is formed only in minor quantities, if at all.     

Reliability of the Part II board certification examination in psychiatry: examination stability

OBJECTIVE: The aim of this study was to examine the reliability (examination stability) of the American Board of Psychiatry and Neurology (ABPN) Part II (oral) examination in psychiatry. METHOD: The authors analyzed the consistency (agreement between grades given by two independent examiners) for a 1-year examination cycle using a weighted kappa statistic and compared different parts of the examination (live patient and videotape), different examination sites, different days, and different times of the day. RESULTS: There was no significant difference in agreement between examiners by different parts of the examination, examination site, day of the week, or time of day. CONCLUSIONS: The stability of the Part II ABPN examination in psychiatry is not influenced significantly by the format or site of administration. Candidate performance is the predominant factor in the determination of passing or failing grades.     

Metabolic responses to preexercise meals containing various carbohydrates and fat

Renal function was examined after unilateral release, bilateral release or unilateral release and contralateral nephrectomy in three groups of rats following 24 h of bilateral ureteral obstruction (BUO). Excretion of water, sodium and urea was significantly greater in rats with unilateral release of BUO than in a single kidney of rats with bilateral release of BUO, in spite of similar levels of glomerular filtration rate (GFR) and effective renal plasma flow. Rats with unilateral release of obstruction and contralateral nephrectomy had a significantly lower GFR than the other two groups. These rats also responded with greater increases in fractional sodium and water excretion to the administration of exogenous atrial peptide. The results demonstrate a marked compensatory increase in sodium and water excretion in rats with unilateral release of the obstruction which serves to maintain homeostasis of fluid and salt. They also suggest a possible influence of the continuously obstructed kidney on the function of the postreleased kidney. The results also provide experimental support for a greater recovery of renal excretory function after bilateral release of obstruction.     

Long-term survival of an AIDS patient with a tuberculous cerebral abscess

Unlike other forms of tuberculosis, tuberculous cerebral abscess is a rare complication of human immunodeficiency virus (HIV) infection and usually presents at a late stage of the disease. This article describes a case of tuberculous cerebral abscess in an HIV-infected patient that was effectively treated with surgery and chemotherapy. The patient has survived more than 5 1/2 years since being diagnosed and remains in good health.     

Measurement of the statistics of DFB laser frequency fluctuations

The statistics of the frequency of the bandpass filtered beat signal between a DFB-laser and an external cavity laser were measured. The distribution of frequency fluctuations from the centre frequency is shown to be very close to Gaussian, with the variance given by the product of beat signal linewidth and IF-filter bandwidth     

Occult hereditary spherocytosis in aplastic crisis of unknown cause

We describe two cases of aplastic crisis of unknown origin, occurring within one week in a 49-year old man and his 20 year old son. They both had undiagnosed hereditary spherocytosis, and both of them had earlier had a B19-parvo infection without having symptoms of aplastic crisis at the same time. Chronic haemolytic anaemia should be considered in adult patients with acute severe anaemia caused by aplastic crisis.     

Analysis of the in vitro cytokine production by liver-infiltrating T cells of patients with autoimmune hepatitis

The pathogenic mechanisms underlying the development of autoimmune hepatitis (AIH) are still unclear. Since AIH is associated with the presence of various autoantibodies and certain HLA subtypes, it is likely that T and B cells play a major role in this disease. In this study we have determined the functional capacities of in vivo preactivated liver-infiltrating T cells (LTC) from patients with AIH. As controls we used LTC from patients with non-autoimmune hepatitis (non-AIH). Our results show that preactivated LTC from patients with AIH predominantly (190/255 clones) reside in the CD4+ population, whereas LTC in non-AIH are dominated by the CD8+ phenotype (148/254 clones). In view of this finding we have investigated the cytokine secretion patterns of 102 randomly chosen CD4+ T cell clones from six patients with AIH. As controls we have used 58 CD4+ LTC from 11 patients with non-AIH. All clones were stimulated by lectin and irradiated accessory cells and subsequent cytokine production was evaluated. LTC from patients with AIH have a lower interferon-gamma (IFN-gamma)/IL-4 ratio compared with LTC from non-AIH. Although clones from some patients with AIH produced very high amounts of IL-4 in vitro, this was not a constant finding. These results show that in vivo preactivated LTC from patients with AIH are mostly CD4+ T cells that produce more IL-4 than IFN-gamma. In contrast, LTC from patients with non-AIH are dominated by CD8+ and CD4+ T cells that produce significantly less IL-4 than IFN-gamma. Thus, liver-infiltrating T cells from patients with AIH and non-AIH belong to different functional T cell subsets. This may have implications for the regulation of humoral and cellular immune responses in inflammatory liver disease.