Lymphocytic choriomeningitis virus

Lymphocytic choriomeningitis (LCM) virus-specific complement-fixing (CF) antigen (ECFA) has been solubilized, concentrated, and partially purified. When inoculated together with Freund's adjuvant, ECFA induced CF antibody but not neutralizing antibody or protective immunity. By itself it boosted pre-existing CF antibody but not neutralizing antibody. In double diffusion tests one line developed between ECFA and its antiserum, and a corresponding line became visible when ECFA interacted with an antiserum directed against all LCM virus-specific antigens. Absorption of either serum with ECFA abolished all ECFA-precipitating qualities. Ouchterlony tests also revealed that ECFA prepared from cells and tissues of various species is immunologically identical. By a variety of procedures ECFA was not found to be represented on the surface of either the virion or the infected cell. When purified infectious LCM virus was disrupted, a CF antigen corresponding immunologically to ECFA was set free. In double diffusion tests this antigen gave a line of identity with ECFA. Thus, ECFA appears to be an internal component of the infectious LCM virus.Part of the work reported here has been published in preliminary communications [8, 10, 24, 25].     

Segmental jejunal lipomatosis--a rare cause of intestinal obstruction

A rare case of a segmental small intestinal (jejunal) lipomatosis is described. A 33-year-old male was admitted with a clinical diagnosis of an acute intestinal obstruction. A plain erect abdominal x-ray showed multiple air-fluid levels. On an exploratory laparotomy, a jejunojejunal intussusception was found secondary to a segmental submucosal lipomatosis. This was treated by a segmental resection and anastomosis, which resulted in a complete cure. Here we present this case with a review of the relevant literature.     

Assessing the effects of bupropion SR on mood dimensions of depression

BACKGROUND: We assessed the therapeutic effects of bupropion SR and placebo on mood and anxiety symptoms derived from the tripartite model of mood. Based on evidence indicating linkages between dopaminergic activity and the emotional dimension of positive affect/anhedonia, we hypothesized that the dopaminergic effects of bupropion SR would yield particularly pronounced effects on symptoms of anhedonia, relative to anxiety. METHODS: Nineteen depressed outpatients were randomly assigned to treatment with either bupropion SR 300 mg/day or placebo during a 6-week initial treatment phase. This was followed by a second open-label phase in which patients previously treated with bupropion SR had their dose increased to 400 mg/day, and the placebo group was initiated on bupropion SR 300 mg/day. RESULTS: Random regression analyses revealed that during the initial double-blind phase, bupropion SR elicited greater declines than placebo on all measures except those that assessed anxiety. By contrast, the weakest placebo effects were evident on anhedonia. Items assessing the low positive affect pole of the anhedonia dimension were more sensitive to earlier/lower dose bupropion SR treatment, whereas items assessing the high positive affect pole were more sensitive to later/higher dose bupropion SR treatment. LIMITATIONS: Replication and extension using a larger sample size are mandated. CONCLUSIONS: This study suggests that the catecholaminergic effects of bupropion SR tended to produce more robust effects on anhedonia/positive affect than placebo.     

Specific Pseudomonas Immunoglobulin E Antibodies in Sera of Patients with Cystic Fibrosis

Immunoglobulin E antibodies to Psuedomonas aeruginosa were demonstrated in patients with cystic fibrosis colonized with the bacterium.     

Immune and autoimmune aspects of diabetes mellitus

The immune and autoimmune aspects of diabetes mellitus are reviewed. Emphasis is given to the clinical association of diabetes with other autoimmune disease; the increased incidence of organ-specific autoimmunity in diabetic patients; the occurrence of humoral and cell-mediated antipancreas (islet) autoimmunity in diabetes; the association of HLA with juvenile-onset, insulin-dependent diabetes mellitus and with certain specific subpopulations of diabetic patients; the possible role of viruses in the etiology of diabetes; and the occurrence of alterations in humoral and cell-mediated immunity, granulocyte function, and the host defense against infectious agents in human diabetics and in animals with experimental diabetes.     

Effects of selective NMDA and non-NMDA blockade in the nucleus accumbens on the plus-maze test

Effect of blocking N-methyl-D-aspartic acid (NMDA) and non-NMDA-glutamatergic receptors on performance in the plus-maze was studied in male rats bilaterally cannulated into the nucleus accumbens (Acc). Rats were divided into seven groups that received either 1 microl injections of saline, (+/-)2-amino-7-phosphonoheptanoic acid (AP-7, 0.2, 0.5, or 1 microg) or 2,3 dioxo-6-nitro-1,2,3,4,tetrahydrobenzo-(f)quinoxaline-7-sulphonamide disodium (NBQX, 0.2, 0.5, or 1 microg) 15 min before testing. Time spent in open arm, time per entry, end arrivals, open, closed, and total arm entries, relationship between open-, closed-, and total arm entries, rearing, face-, head-, and body grooming, and number of fecal boli were recorded. Time spent in the open arm increased under AP-7 (0.5 and 1 microg; P<.01) and NBQX (1 microg; P<.05) treatment, whereas time per entry was increased only with AP-7 (1 microg; P<.05). Open arm entries were increased by the intermediate doses of AP-7 (0.5 microg; P<.01) and NBQX (0.5 microg; P<.05); end arrivals were increased by the intermediate dose of AP-7 (0.5 microg/1 microl, P<.05). The frequency of rearing, grooming, and closed arm entries was not affected by the treatment. We conclude that NMDA and non-NMDA-glutamatergic blockade in the Acc lead to a behavioral disinhibition of cortical influences with the median doses, but that at higher doses the blockers have an anxiolytic-like effect.     

Different histopathological response to Arenovirus infection in thymectomized mice

Summary In this paper the survival and the histopathology of normal and thymectomized mice infected with some Arenoviruses is reported.Normal newborn mice infected intracerebrally with Junín, Machupo, Tacaribe and Amaparí virus showed similar histopathological changes in the central nervous system characterized by choroiditis, glial hyperplasia, vasculitis and perivasculitis with infiltration of lymphocytic cells.In thymectomized mice infected with Junín, Machupo and Tacaribe virus, there was no evidence of disease, survival reached almost 100% and no pathological alterations were observed in the brain.In contrast, thymectomized mice infected with Amaparí virus showed the same percentage of mortality and similar histopathological changes as non-thymectomized animals.This research was supported by Grant N 4908/71 from Consejo National de Investigaciones Cientificas y Técnicas, República Argentina, and by funds from Comisión Coordinadora para el estudio y lucha contra la Fiebre Hemorrágica Argentina de la Subseeretaría de Salud Pública, República Argentina.Chairman Department of Pathology, National Academy of Medicine, República Argentina.Members of Research Career from the Consejo Nacional de Investigaciones Cientificas y Técnicas, República Argentina.     

Increased phagocytic capacity of the blood,but decreased phagocytic activity per individual circulating neutrophil after an ultradistance run

The effect of a long strenuous endurance exercise on the phagocytic function of neutrophils was examined. 9 athletes [7 males, 2 females, age: 36–68 years, body mass: 64 (SD 10) kg, height: 175 (SD 10) cm] completed a competetive 100 km run in 8:07 (median value; range: 7:29–9:50 hours). In a whole blood assay the phagocytosis of opsonized E. coli, the receptor density of the Fc receptor 3 (CD16) and the complement receptor 3 (CD11b, direct immunofluorescence) of neutrophils were measured on a per cell basis by flow cytometry before and up to 3 hours after the race. The phagocytic rate (percentage of neutrophils incorporating bacteria) was unchanged after exercise, whereas the phagocytic activity (number of incorporated bacteria per cell) was significantly reduced by –34 (SD 8) % (Wilcoxon test, P<0.001). The total phagocytic capacity of the blood increased 2-3fold post exercise. The surface antigen expressions of CD11b and CD16 were unaffected by the ultradistance run. The results indicate either a reduced phagocytic function of neutrophils on a single cell basis or the mobilization of neutrophils of the marginal pool with a lower phagocytic activity. However, after a long endurance exercise the phagocytotic capacity of the blood was enhanced due to increased cell concentrations.     

Mobilization and oxidative burst of neutrophils are influenced by carbohydrate supplementation during prolonged cycling in humans

Prolonged, strenuous exercise may lead to suppressive effects on the immune system, which might be responsible for a greater susceptibility to opportunistic infections. The aim of this study was to examine the influence of carbohydrate substitution (CHS) during prolonged, strenuous exercise on neutrophil granulocytes and their oxidative burst (intracellular oxidation of dihydrorhodamine₁₂₃ to rhodamine₁₂₃ after induction by formylized 1-methionyl-1-leucyl-1-phenylalanin) using flow cytometry. In three trials different concentrations of CHS (placebo compared to 6% and 12% CHS; 50 ml·kg^–1) were given randomly to 14 endurance trained cyclists [mean (SD) age 25 (5) years, maximal oxygen uptake 67 (6) ml·min^–1·kg^–1] cycling for 4 h in a steady state at 70% of their individual anaerobic threshold. Blood samples were taken before, immediately after cessation, 1 h and 19 h after exercise. A significant rise in neutrophil counts was observed immediately after cessation and 1 h after exercise with a return to normal rest values 19 h after exercise for all three conditions (P<0.001). The relative proportions of rhodamine₁₂₃+ neutrophils were significantly diminished in all three conditions 1 h after exercise (P<0.01), while the mean fluorescence intensity was lowest in the placebo trial and differed significantly to the 12% CHS trial (P=0.024) and almost significantly to the 6% CHS trial (P=0.052). In conclusion, these data suggest a beneficial effect of CHS on the neutrophil oxidative burst and a possible attenuation of the susceptibility to infections, presumably due to the reduction of metabolic stress in prolonged, strenuous exercise. Electronic Publication