Aeromonas sobria necrotizing fasciitis complicating neonatal sclerosing cholangitis

Aeromonas species can cause gastroenteritis, soft tissue infections, hepatobiliary tract and other infections. While most reported soft tissue infections have been attributed to Aeromonas hydrophila, we report a case of necrotizing fasciitis caused by Aeromonas veronii biovar sobria. Prompt and accurate diagnosis cum treatment could help save children with Aeromonas soft tissue infections from developing a bacteremia with extended morbidity and mortality.     

Evaluation of mutagenic,recombinogenic and carcinogenic potential of (+)-usnic acid in somatic cells of Drosophila melanogaster

The main of this study was to evaluate the mutagenic and carcinogenic potential of (+) – usnic acid (UA), using Somatic Mutation and Recombination Test (SMART) and the test for detecting epithelial tumor clones (wts) in Drosophila melanogaster. Larvae from 72 ± 4 h from Drosophila were fed with UA (5.0, 10.0 or 20.0 mM); urethane (10.0 mM) (positive control); and solvent (Milli-Q water, 1% Tween-80 and 3% ethanol) (negative control). ST cross produced increase in total mutant spots in the individuals treated with 5.0, 10.0 or 20.0 mM of UA. HB cross produced spot frequencies in the concentration of 5.0 mM that were higher than the frequency for the same concentration in the ST cross. In the highest concentrations the result was negative, which means that the difference observed can be attributed, in part, to the high levels of P450, suggesting that increasing the metabolic capacity maximized the toxic effect of these doses. In the evaluation of carcinogenesis using the wts test, the results obtained for the same concentrations of UA show a positive result for the presence of tumors when compared to the negative control. We conclude that UA has recombinogenic, mutagenic and carcinogenic effects on somatic cells in D. melanogaster.     

Functional characteristics of intraepithelial lymphocytes from mouse small intestine. III. Inability of intraepithelial lymphocytes to induce a systemic graft-versus-host reaction is because of failure to migrate in vivo.

In this study we have investigated whether addition of bone marrow accessory cells or concurrent administration of recombinant IL-2 would allow intraepithelial lymphocytes (IEL) to induce a systemic, lethal GvHR in irradiated hosts. In addition we have studied the ability of IEL to migrate into lymphoid tissues after intravenous injection and compared this with their locomotor capacity in vitro.     

THE PROLONGED COEXISTENCE OF VACCINIA VIRUS IN HIGH TITRE AND LIVING CELLS IN ROLLER TUBE CULTURES OF CHICK EMBRYONIC TISSUES

1. The virus of vaccinia in so called roller tube cultures of mixed embryonic chick tissue rapidly increases to maximal titre. 2. Under these conditions the quantity of virus in the tissue remains at or near the maximum for at least 9 weeks and considerable amounts are present in the fluids removed each day. 3. The same results are obtained when only fragments of embryonic chick heart are employed. 4. Many, though not necessarily all, of the cells in infected cultures remain alive and retain the capacity to proliferate. The presence of these living cells is essential for the persistence of the virus. 5. No apparent differences in the rate or amount of growth of cells in infected as contrasted with non-infected cultures can be discerned in the gross. 6. It is suggested, but not proved, that virus is continually being produced rather than simply preserved throughout the period.     

Epidemic diarrheal disease of suckling mice; the effect of strain,litter, and season upon the incidence of the disease

Four strains of mice-Harvard, Schwentker, CFW (Carworth Farms), and C (National Cancer Institute)-have been kept and bred underidentical conditions over the course of a year in order to determine the effect of strain, of litter, and of season upon the incidence of diarrheal disease among the suckling mice. 1. Significant strain differences were limited to CFW mice. A consistently lower percentage of these mice were weaned in comparison to the others. 2. The effect of litter was definite and consistent: In all four strains first litters fared worse than second and third ones, while fourth and fifth litters showed the highest percentage of mice weaned. 3. The effect of season seemed clear cut only in the case of one strain CFW; the highest percentage of mice weaned were observed during the summer months and the lowest during the autumn and early winter.     

Cirrhosis and other hepatic lesions produced in dogs by thyroidectomy and by combined hypophysectomy and thyroidectomy

1. The reactions of the dog's liver to (a) thyroidectomy and (b) both hypophysectomy and thyroidectomy are described. 2. Fatty changes of varying severity were detected in 8 of the 9 hypophysectomized-thyroidectomized dogs, hepatic fibrosis in 7, and severe cirrhosis in 4 animals of this group. Among the thyroidectomized animals histologically demonstrable fatty livers were present in all 8, mild fibrosis was observed in 4, while early and mild cirrhosis was diagnosed in only one dog. 3. Two pathogenetically distinct forms of cirrhosis were present in the livers of dogs with the two operations, namely (a) cirrhosis initiated and developing around the radicles of the hepatic veins, and (b) periportal cirrhosis. Both forms of cirrhosis occurred in dogs that were subjected to the same experimental procedures, and both forms could be found in the same liver. The pathogenesis of these two forms of cirrhosis is described. 4. The relation between fatty change in the liver and the genesis of fibrosis is discussed, and it is suggested that, while fatty change may facilitate the evocation of cirrhosis, this reaction on the part of the supporting and vascular elements of the liver is not solely dependent on the fatty change in the liver cells. 5. The relation between the endocrines and hepatic cirrhosis is discussed. Since cirrhosis was slight in the fatty livers of thyroidectomized dogs, whereas it was often advanced in hypophysectomized-thyroidectomized dogs, it is suggested that in the absence of the pituitary cirrhogenic mechanisms are facilitated in the dog.     

In vivo and in vitro analysis of chloroquine resistance in Plasmodium falciparum isolates from Senegal

To determine the predictive value of chloroquine (CQ) resistance markers in Senegal, Plasmodium falciparum DNA polymorphisms in pfmdr1and pfcrt were examined in relation to clinical outcome. Despite CQ treatment, 17% of patients had parasitemia after 28 days. Examination of molecular markers of CQ resistance revealed that 64% of all isolates had the T76 resistant allele at the pfcrt locus, while 30% carried the Y86 resistant allele at the pfmdr1 locus. The pfcrt T76 allele was present not only in all in vivo resistant isolates, 89% of in vitro resistant isolates, but also in 35% of in vitro sensitive isolates. The pfmdr1 N86Y polymorphism did not correlate with in vitro or in vivo CQ resistance. Our data suggest that the pfcrt T76 allele alone is required but not a sufficient predictor for in vivo CQ resistance.     

Parasitism by Virulent Treponema pallidum of Host Cell Surfaces

The interaction between virulent Treponema pallidum extracted from infected rabbit testes and animal cells in culture was examined. The extent of treponemal attachment to monolayers of normal rabbit testicular and HEp-2 cells was dependent upon the incubation temperature and retained motility of the spirochetes. The specific orientation of treponemes to host cell surfaces was demonstrated by dark-field microscopic examination of wet-mount preparations and scanning and transmission electron microscopy. Once attached, T. pallidum organisms remained actively motile yet anchored in place by their terminal tapered structures. After several hours of co-incubation, maximal attachment was attained, and the degree of parasitism seemed regulated not only by available surface sites on individual host cells but also by the proposed membrane response of parasitized cells to continued exposure to treponemes. The avirulent strain, Treponema phagedenis biotype Reiter, did not adhere to monolayer cultures. Characterization of host cell determinants that permitted surface colonization by T. pallidum was attempted. Also, properties of virulent treponemes that enabled surface parasitism were monitored by measuring the effects of enzymes, detergents, and metabolic inhibitors on the host-parasite interaction. Results reinforced the specific nature of the treponemal attachment mechanism. Furthermore, the ability of convalescent rabbit sera to reduce attachment of treponemes to host cells suggested that surface structures on T. pallidum could be masked or inactivated by host components, thus providing a potentially effective research approach for investigating the pathogenesis of syphilis and screening appropriate vaccine candidates.     

IL-18 induces the differentiation of Th1 or Th2 cells depending upon cytokine milieu and genetic background

The functional division of CD4(+) T cells into Th1 and Th2 subsets is generally accepted but the mechanisms leading to their preferential induction remain elusive. Cytokines are considered the main determining factors in the initial differentiation of precursor T cells into these distinct subsets. Thus, IL-12 drives Th1 cells whereas IL-4 drives Th2 cells. Recently IL-18, originally designated as IFN-gamma-inducing factor, has been reported to synergize with IL-12 in the induction of Th1 cells. We report here that IL-18 can also induce T cells to differentiate into Th2 cells, in the presence of TCR activation, either alone or together with IL-4. This effect of IL-18 is mediated primarily on CD4(+) T cells compared with CD8(+) T cells and is inhibited in the presence of IL-12. IL-18, however, has no effect on functionally committed Th2 cells.( )Moreover, the effect of IL-18 on Th2 cell development is differentially manifest in different mouse strains, suggesting profound underlying genetic influences. BALB/c mice infected with Leishmania major and treated with recombinant IL-18 developed exacerbated disease and enhanced Th2 response compared with untreated controls. These data therefore provide a novel mechanism for Th2 cell development. Thus, IL-18, a cytokine constitutively expressed by cells of the innate response, is capable of inducing Th2 cell differentiation in the absence of IL-4.     

Reactivity of Hybridoma Antibodies with Amniotic and Plasma Fibronectin

Mouse antibodies were prepared to human amniotic fluid fibronectin by means of somatic cell hybrids. Comparison of immunological reactivity of antibodies with amniotic and plasma fibronectin revealed that the two molecules had very similar patterns of antigenic determinants. Antibodies from one cell population, however, bound belier to amniotic fluid fibronectin, indicating that there is a difference in the molecular structure of fibronectins isolated from the two sources.