Congenital transmission of Trypanosoma cruzi: an operational outline for detecting and treating infected infants in north-western Argentina. (57/2009)

We designed a set of procedures for first-line local health services to detect and treat the congenital transmission of Trypanosoma cruzi at a province-wide scale, and field-tested the programme in the province of Tucuman, northwestern Argentina, from 1992 to 1994. The programme consists of routine screening of pregnant women for seroreactivity to T. cruzi, serological and parasitological follow-up of the newborn at least twice during the first year of age, treatment of the infected infants, and evaluation of the outcome. 927 (5.5%) of 16 842 pregnant women were seroreactive to T. cruzi by indirect haemagglutination assay and ELISA. Twenty-one (6.7%) of 315 newborns to seroreactive mothers were diagnosed as infected with T. cruzi parasites microhaematocrit concentration before 30 days of age. Five newborns who initially tested negative had a T. cruzi infection detected by microhaematocrit and/or serological techniques at 3 or 6 months of age. Thus, congenital infection was diagnosed in 26 (7.1%) infants born to seroreactive women and residing in houses free of triatomine bugs. Four of 6 infants born to seroreactive mothers died during the first year of age and had some evidence of T. cruzi infection; one of the deaths was attributed to T. cruzi based on clinical evidence. After specific treatment with nifurtimox or benznidazole, 30 of 32 infants remained parasitologically and serologically negative. This study shows the feasibility of controlling the incidence of congenitally acquired T. cruzi infections at a province-wide scale by means of a specific screening programme at first-line health services level.  (+info)

Pseudomonas (Burkholderia) pseudomallei in Thailand, 1964-1967: geographic distribution of the organism, attempts to identify cases of active infection, and presence of antibody in representative sera. (58/2009)

The purpose of this study, initiated in 1964 and concluded in 1967, was to define the distribution of Pseudomonas (now Burkholderia) pseudomallei in Thailand, to evaluate its importance as an etiologic agent, and to survey the presence of antibody in people that might indicate prior infection and/or contact with the microorganism.  (+info)

Pilus-mediated adherence of Haemophilus influenzae to human respiratory mucins. (59/2009)

Haemophilus influenzae, especially the nontypeable strains, are among the most common pathogens encountered in patients with chronic lung disease and otitis media. We and others have demonstrated that respiratory isolates of nontypeable H. influenzae bind to human mucins, but the mechanism of binding is not entirely clear. We have therefore examined the role of pili in the adherence of both type b and nontypeable H. influenzae to human respiratory mucins. We used isogenic H. influenzae strains with a mutation in the structural gene for pilin (hifA), a laboratory H. influenzae strain transformed with a type b pilus gene cluster (from strain C54), antibodies raised against H. influenzae HifA, and Escherichia coli strains carrying a cloned type b pilus gene cluster (from strain AM30) in these studies. All bacteria lacking HifA or the pilus gene cluster had decreased adherence of piliated H. influenzae to mucins, and Fab fragments of anti-HifA antibodies inhibited the adherence. E. coli strains carrying the cloned type b pilus gene cluster were six to seven times more adhesive than strains carrying the vector. The role of other putative adhesins was not examined and thus cannot be excluded, but these studies support a role for pili in the binding of H. influenzae to human respiratory mucins.  (+info)

Susceptibility of inbred rat strains to experimental thyroiditis: quantitation of thyroglobulin-binding cells and assessment of T-cell function in susceptible and non-susceptible strains. (60/2009)

Ten inbred strains of rats were immunized with crude homologous thyroglobulin emulsified in Freund's complete adjuvant in order to investigate strain susceptibility to the induction of both thyroiditis and antibody to thyroglobulin. Two strains (LH and AUG) were found to be extremely susceptible and had 100% incidence of thyroid lesions which in general varied from moderate to very severe (mean index of pathology+/-SE, 2-5+/-0-2 and 2-1+/-0-4 respectively). One other strain (HL) also had 100% incidence of lesions but there were consistently mild in character (1-1+/-0-1). Two strains (DA and SD) were variable, with thyroid change varying from negative to severe. Three strains (LEW, WAG and PVG/c) had occasional lesions and the remaining two strains (AS and CAM) showed no thyroid change. Four strains (LH, AUG, HL and DA) consistently produced good antibody responses to thyroglobulin (mean titres+/-SE 7-3+/-0-3, 9-5+/-0-4, 6-9+/-0-3 and 6-6+/-0-5 respectively). In contrast WAG and CAM rats failed to develop autoantibody and the responses of AS, PVG/c and SD strain rats were quite variable. Although the autoantibody response generally correlated well with the presence of thyroiditis in a particular strain, LEW, AS and PVG/c rats often had good antibody levels with minimal thyroid lesions. Females of the most susceptible strains (LH and AUG) were found to have significantly more severe thyroid lesions and higher antibody titres to thyroglobulin than males. The most susceptible strains were all found to be of the Ag-B5 major histocompatibility genotype whilst the least susceptible were of the Ag-B2 genotype. However, wide interstrain variability was noted within the Ag-B5 genotype particularly with respect to the induction and extent of thyroid lesions. It was not found possible to relate the divergence in susceptibility between rat strains of Ag-B5 and Ag-B2 genotypes to differences in respective numbers of thyroglobulin-binding cells within the circulation of the non-immunized animal. Similarly, there were no differences in response between a susceptible (LH) and non-susceptible (CAM) strain to the phytomitogens PHA and Con A.  (+info)

Field application to malaria studies of the passive haemagglutination (PHA) test with lyophilized cells. (61/2009)

Lyophilized cells for the passive (formerly indirect) haemagglutination test for malaria were tested in a small field trial. A comparison was made with results obtained with samples from the same persons by another method in another laboratory (Center for Disease Control, Atlanta, GA, USA). The use of lyophilized cells of standardized reactivity clearly adds to the simplicity and rapidity of the test, and justifies its recommendation for use in field studies.  (+info)

Thymus dependence of the antibody response to tetanus toxoid in mice. (62/2009)

Both the IgM and IgG antibody responses to tetanus toxoid were greatly reduced in adult thymectomized, irradiated, foetal liver reconstituted mice, in contrast with results published for neonatally thymectomized mice. This evidence lends further support to the notion that all IgG responses to protein antigens are thymus dependent.  (+info)

Hepatitis B antigen, antigen subtypes, and hepatitis B antibody in normal subjects and patients with liver disease. (63/2009)

The relative sensitivities of counterimmunoelectrophoresis (CIE) and haemagglutination assays for the detection of hepatitis B surface antigen (HB(s)Ag) and antibodies (anti-HB(s)) were compared. Twelve scientists from ten countries in Asia, Africa and the Pacific region participated in the study. The participants provided serum samples from 15 953 subjects comprising patients with acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC), as well as blood donors and other normal individuals. For the detection of HB(s)Ag in a reference panel serum, immune adherence haemagglutination (IAHA) was slightly more sensitive than passive haemagglutination inhibition (PHI); CIE was the least sensitive. Mean HB(s)Ag frequencies in patients with acute hepatitis, chronic hepatitis, cirrhosis, and HCC were significantly higher than in healthy controls. Passive haemagglutination (PHA) was more sensitive than CIE for the detection of anti-HB(s). The frequency of anti-HB(s) in patients with HCC was significantly lower than that in the other groups. Mean anti-HB(s) frequencies in patients with acute hepatitis, chronic hepatitis, and cirrhosis were not significantly different from that in normal subjects. Subtyping of HB(s)Ag was performed by PHI. Among asymptomatic carriers the predominant HB(s)Ag subtype in northeast Asia was adr.In India, ayw predominated in carriers, with the demarcation between adr and ayw occurring west of Burma. In West Africa the only subtype detected was ayw, but in East Africa the majority subtype was adw. The r subtype was found only in Asian populations east of India and in Western Pacific populations. In Papua New Guinea all four subtypes were identified. With one possible exception, the subtypes of HB(s)Ag-positive patients with liver disease reflected the predominant type in each geographic location.  (+info)

Hidden' IgG antiglobulins in normal human serum. (64/2009)

Hidden antiglobulins reacting with whole rabbit immunoglobulin were found by radioassay or indirect haemagglutination after gel filtration or ultracentrifugation of normal serum. Suprisingly, both the IgM and IgG antiglobulins were present in the same macroglobulin fractions. The IgG antiglobulins could be dissociated into 7S components by separating the serum under acid conditions. Antiglobulin activity was a function of the Fab region.  (+info)