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Staphylococcus aureus is the principal causative agent of the inflammatory bone disease osteomyelitis. Unfortunately, the pathogenesis of this often chronic infection is poorly understood and is complicated by the recent observation that bone-forming osteoblasts can harbor S. aureus. Such an infection presents a significant challenge for the host immune response, because osteoblasts are not known to initiate protective cell-mediated immune responses. Cultured mouse and human osteoblasts infected with S. aureus were found to express high levels of interleukin (IL)-6 and IL-12p75, on the basis of complementary investigations demonstrating both S. aureus-induced up-regulation of expression of IL-6 and IL-12p40 mRNA and secretion of IL-6 and IL-12p75 by these cells. Additionally, a quantitative bioassay demonstrated that IL-12p75 secreted after infection was biologically active. These studies are the first to demonstrate induced IL-12p75 expression by osteoblasts and suggest a previously unrecognized role for osteoblasts in initiating immune responses after S. aureus infection. [ABSTRACT FROM AUTHOR]

The intensity of infection with Schistosoma haematobium (worm burden) can be approximated by quantifying the number of parasite eggs excreted in the urine. A new method of egg counting has been developed in which urine samples are passed through transparent Nuclepore filters (Nuclepore Corp., Pleasanton, Calif.). The method requires no staining, is rapid, and can be performed in the field. It has previously been reported, however, that there is a significant daily fluctuation in output of eggs in the urine of patients with schistosomiasis haematobia. In the present study, daily urine samples were obtained on each of the 10 school days during a 12-day period from 121 schoolchildren in Coast Province, Kenya (total, 10 samples per child). In terms of detecting infection, it was of interest that egg counts of 0 were very rarely recorded for subjects whose mean egg counts were >20/10 ml of urine. When the patients were classified into one of four groups, according to egg count <1, 1–100, 101–400, >400), the proportion correctly classified based on a single urine specimen was 75%; this proportion rose to 78% when the classification was based on two specimens and to 83% with three specimens. Most of the urine specimens that were misclassified belonged in an adjacent group. [ABSTRACT FROM PUBLISHER]

A test for the lymphokine eosinophil stimulation promoter (ESP) has been adapted to the study of Trichinella spiralis infections in mice and has been used as an aid in the diagnosis of trichinosis in a patient. With use of soluble antigen extracted from T. spiralis larvae and peritoneal exudate cells rich in eosinophils obtained from mice with trichinosis of four weeks' duration, a dose-response curve was constructed and analyzed. The soluble larval antigens greatly enhanced the migration of eosinophils from the mice with trichinosis but had no effect on the eosinophils from mice with schistosomiasis, nor did soluble schistosome egg antigens have any effect on the cells from mice with trichinosis. On two occasions peripheral white blood cells from a patient with presumed T. spiralis infection gave strongly positive results in ESP tests on stimulation with soluble larval antigen, but the cells did not respond significantly to soluble schistosome egg antigen; the result in the ESP test was positive before the patient's serum produced a weakly positive agglutination response. [ABSTRACT FROM PUBLISHER]

The present investigations of the recently discovered lymphokine eosinophil stimulation promoter have (1) shown that the assay system is highly sensitive and reproducible via the establishment of dose-response curves and their statistical analysis, (2) demonstrated that the direct assay is specific with use of eosinophilrich peritoneal exudate cells obtained from mice with either schistosomiasis or trichinosis, (3) demonstrated that the indirect test with splenic lymphocytes is specific with use of both the above method and radioisotope-labeled antigens, and (4) provided information on the roles of eosinophils and mononuclear cells via purification, reconstitution, and the use of antiserum to eosinophils. [ABSTRACT FROM PUBLISHER]

Immunoglobulins (IgG; IgM, IgA, IgD, and IgE) in serum were measured in three age groups of Negroid people: 5–9 years, 10–14 years, and adult in St. Lucia and St. Vincent and 10–14 years in Cleveland. The St. Lucians and St. Vincentians are comparable populations of Caribbean islands 30 miles apart. All the St. Lucians in the study were infected with schistosomiasis and many had other intestinal parasites; none from St. Vincent had schistosomiasis but many had intestinal parasites. Those in Cleveland had neither schistosomiasis nor any intestinal helminthic infections. The St. Lucians had a significantly higher level of IgG in all age groups and a higher level of IgM in the age group 5–9 years; both of these differences have been reported in other populations but without adequately matched control groups. There were no striking differences in the mean concentrations of IgA and IgD. IgE levels were markedly higher in both island groups than in the Cleveland group, but since the mean values were similar for younger and older children, this difference cannot be attributed primarily to schistosomiasis. The mean IgE level of the St. Lucian adults was more than fivefold higher than that of the St. Vincentians; this difference might be attributable to schistosomiasis. [ABSTRACT FROM PUBLISHER]

Mice that had a light, chronic infection with Schistosoma mansoni were superinfected by the intravenous and oral routes with Salmonella enteritidis or Listeria monocytogenes, and the course of infection was monitored by observation of the growth of the organisms in vivo, as well as by compilation of data on mortality. No increase in resistance was shown against the intravenously injected Salmonella. Despite extensive pathologic changes in the organs of mice infected with schistosomes, bacteria were cleared normally. Orally administered salmonellae eventually caused a more severe systemic infection with a rapid rise in counts in organs. Schistosome-infected mice, periodically challenged with Listeria, displayed an increased nonspecific resistance at two and eight weeks after the initiation of the helminthic infection, and a phase of decreased resistance late in the course of the schistosomiasis. The periods of increased resistance are probably the result of stimulation of the reticuloendothelial system by soluble schistosomal antigens that are known to be released at these times. [ABSTRACT FROM PUBLISHER]

Determination of the efficacy of mass treatment of schistosomiasis is usually based on the rate of cure. However, schistosomes do not multiply in the human host, disease tends to cluster in the small proportion of individuals with heavy infections, and reinfection continually occurs in endemic areas. Thus drastic reduction in worm burdens can be a reasonable goal for mass treatment campaigns. The standard dose and regimen of metrifonate for the treatment of schistosomiasis haematobia is 7.5 mg/kg administered in three doses two weeks apart. This treatment results in a cure rate of ∼50% and a reduction in egg output of 94.5%. In the present study, 72 infected children with egg counts before treatment that averaged from 0.1 to 2,334/10 ml of urine were treated with a single oral dose of 10 mg of metrifonate/kg: the cure rate was 22%, and the reduction in egg output was 96.5%. No side effects were recorded. [ABSTRACT FROM PUBLISHER]

The effects of diets containing 8% and 4% protein and of 50% calorie-deficient diets on the host, the parasite, and the parameters of disease in chronic hepatosplenic schistosomiasis were studied in mice that were infected for 20 weeks with Schistosoma mansoni. Controls consisted of uninfected mice of the same size and age maintained on a balanced 20% protein diet. Each of four corresponding dietary groups of infected and uninfected animals was fed on its assigned diet from the 20th to the 24th week of infection. Between the 24th and the 28th week of infection, all groups were nutritionally repleted by being returned to the standard control diet. Changes in body weight and deaths were recorded throughout the experiment (20-28 weeks). Parasite and host responses were measured at 24 weeks and again at 28 weeks. Severe protein and calorie deficiencies were associated with diminished egg output, an effect that appeared to be residual in the most severely malnourished animals for some time after malnutrition has been corrected. In general, the parameters of hepatosplenic disease were less severe in the more severely malnourished animals; 50% calorie deficiency was the cause of greater amelioration than marked protein depletion. During the period of malnutrition the mortality rate in mice given the 4% protein diet was not significantly different from that in controls (approximately 30%), while that in the calorie-restricted animals was only 9%.