Immunoglobulin G and immunoglobulin M polar staining of Toxoplasma gondii in the indirect immunofluorescence test.

Polar staining (PS) of Toxoplasma gondii in the indirect immunofluorescence test has been considered a nonspecific reaction caused exclusively by certain immunoglobulin M (IgM) antibodies and confined to the anterior end of the parasite. After we observed a patient with positive serology for Chagas' disease who presented an IgG PS reaction, we studied sera from 120 patients with Chagas' disease, 20 sera from patients with Leishmania donovani infection, and 30 sera from patients with Leishmania braziliensis infection. When only those specimens having no detectable anti-Toxoplasma activity were considered, a significantly (P less than 0.01) higher prevalence of IgG PS was found in the Chagas' disease and L. donovani groups than in sera from normal American and Brazilian adults. Those sera also showed higher PS titers (1:64 to 1:1,024) when compared with controls (1:16 to 1:64). IgG PS titers did not decrease after serum treatment with 2-mercaptoethanol. However, the same treatment removed completely IgM PS. IgG PS, but not IgM PS, could be removed by adsorption with Trypanosoma cruzi epimastigotes. IgM PS was found in all samples studied, except in 41 of a group of 43 umbilical cord sera. It was found that the antigen source and the microscopy system can influence the detection of PS. It is proposed that after finding an intense IgG PS reaction, the laboratory should screen such serum also for anti-T. cruzi antibodies which may be undetected in the sample.     

Fluorescence in situ hybridization analysis of HER-2/neu in brushings of normal oral mucosa

Oncogene alterations have been clearly demonstrated to be related to the carcinogenesis and progression of oral squamous cell carcinoma (OSCC). However, the analysis of these alterations for screening and early diagnostic purposes generally requires invasive techniques for surgical removal of pathological epithelium. The aim of the present study was to assess the feasibility of fluorescence in situ hybridization (FISH) analysis of HER-2/neu amplification in oral mucosa brushings and to compare the HER-2/neu status with the history and smoking and drinking habits of healthy subjects. Cells obtained by centrifugation of oral brushings from 21 subjects (overall no. of cells: 5125) were suspended in physiological saline and fixed onto two slides for cytological evaluation and FISH analysis (dual-target, dual-color fluorescence assay) of the HER-2/neu gene and CEP17 centromere. A mean of 89.8% of the cells showed two HER-2/neu signals and a mean of 94% had two CEP17 signals at fluorescent microscopy. Finally, a mean of 96% of cells with HER-2/neu / CEP17 had a ratio equal to 1. No association between smoking and drinking habits, age and the HER-2/neu and CEP17 characteristics evaluated by FISH was found.     

Linkage mapping of a nonspecific form of X-linked mental retardation (MRX53) in a large Pakistani family

Nonspecific X-linked mental retardation is a nonprogressive, genetically heterogeneous condition that affects cognitive function in the absence of other distinctive clinical manifestations. We report here linkage data on a large Pakistani family affected by a form of X-linked nonspecific mental retardation. X chromosome genotyping of family members and linkage analysis allowed the identification of a new disease locus, MRX53. The defined critical region spans approximately 15 cM between DXS1210 and DXS1047 in Xq22.2-26. A LOD score value of 3.34 at no recombination was obtained with markers DXS1072 and DXS8081.     

Dual role of interleukin-4 (IL-4) in pulmonary paracoccidioidomycosis: endogenous IL-4 can induce protection or exacerbation of disease depending on the host genetic pattern

Resistance to paracoccidioidomycosis, the most important endemic mycosis in Latin America, is thought to be primarily mediated by cellular immunity and the production of gamma interferon. To assess the role of interleukin-4 (IL-4), a Th2 cytokine, pulmonary paracoccidioidomycosis in IL-4-depleted susceptible (B10.A) and intermediate (C57BL/6) mice was studied. Two different protocols were used to neutralize endogenous IL-4 in B10.A mice: 1 mg of anti-IL-4 monoclonal antibody (MAb)/week and 8 mg 1 day before intratracheal infection with 10(6) Paracoccidioides brasiliensis yeast cells. Unexpectedly, both protocols enhanced pulmonary infection but did not alter the levels of pulmonary cytokines and specific antibodies. Since in a previous work it was verified that C57BL/6 mice genetically deficient in IL-4 were more resistant to P. brasiliensis infection, we also investigated the effect of IL-4 depletion in this mouse strain. Treatment with the MAb at 1 mg/week led to less severe pulmonary disease associated with impaired synthesis of Th2 cytokines in the lungs and liver of control C57BL/6 mice. Conversely, in IL-4-depleted C57BL/6 mice, increased levels of tumor necrosis factor alpha and IL-12 were found in the lungs and liver, respectively. In addition, higher levels of immunoglobulin G2a (IgG2a) and lower levels of IgG1 antibodies were produced by IL-4-depleted mice than by control mice. Lung pathologic findings were equivalent in IL-4-depleted and untreated B10.A mice. In IL-4-depleted C57BL/6 mice, however, smaller and well-organized granulomas replaced the more extensive lesions that developed in untreated mice. These results clearly showed that IL-4 can have a protective or a disease-promoting effect in pulmonary paracoccidioidomycosis depending on the genetic background of the host.     

Evaluation of dot enzyme-linked immunosorbent assay for mucocutaneous leishmaniasis and comparison with microplate enzyme immunoassay.

A dot enzyme-linked immunosorbent assay (dot ELISA) was evaluated and compared with a standard microplate ELISA (immunoglobulin G [IgG] ELISA) for the serological diagnosis of mucocutaneous leishmaniasis. The two assays were used to test 113 serum specimens from the following groups: normal individuals and patients with deep mycoses, toxoplasmosis, mucocutaneous leishmaniasis, visceral leishmaniasis, Chagas' disease, malaria, and schistosomiasis. Both tests exhibited cross-reactivity when testing specimens from cases of visceral leishmaniasis and Chagas' disease. The dot ELISA proved to be economical with respect to use of reagents and was easy to perform. Interpretation could easily be made by visual inspection of reaction endpoints in the nitrocellulose disks, obviating the need for spectrophotometric readings. There were no significant differences in sensitivity between the dot ELISA and the IgG ELISA at a cutoff level either of 20 or 40. However, its most remarkable feature was the high specificity compared with that of the IgG ELISA. Because of its ease of performance and high sensitivity and specificity, the dot ELISA should be an excellent test to be executed in the field during seroepidemiological surveys.     

Screening of HIV-1 isolates by reverse heteroduplex mobility assay and identification of non-B subtypes in Italy

OBJECTIVE: The increasing prevalence of HIV-1 transmission through heterosexual contacts and the growing number of immigrants from non-Western countries, where non-B subtypes and recombinant forms are prevalent, suggest the possible emergence in Italy of a new epidemic wave of HIV-1 non-B subtypes as well as recombinant forms. METHODS: The distribution of HIV-1 subtypes has been evaluated in 63 seropositive individuals residing in Italy, most of whom were infected through a sexual route during the last 5 years. A modified heteroduplex mobility assay (HMA) strategy, reverse HMA (rHMA), has been developed in our laboratory, allowing rapid identification of divergent-from-B-subtype isolates, which have been subsequently characterized by detailed molecular and phylogenetic analyses. RESULTS: Five samples show, on rHMA, an electrophoretic pattern compatible with a non-B subtype classification. Their phylogenetic analysis, performed on both env and gag regions, confirms the rHMA subtyping prediction, given that 3 samples fall into the "A-family" subtype and 2 into the G subtype. The 5 non-B-subtype HIV-1 isolates have been identified among 23 variants (prevalence, 21.74%) isolated during the 2000 to 2001 period in heterosexuals. In parallel, B-subtype isolates show high levels of intrasubtype nucleotide divergence, compatible with a constant HIV-1 molecular diversification. CONCLUSION: The Italian HIV-1 epidemic is still mostly attributable to the B subtype, which shows an increasing nucleotide heterogeneity. Heterosexual transmission and the interracial blending, however, are slowly introducing novel HIV-1 subtypes, and the data indicate that rHMA represents a powerful tool for HIV-1 biomolecular screening in epidemics characterized by a mono-/dual-subtype predominance.     

Genomic allelotyping for distinction of recurrent and de novo hepatocellular carcinoma after orthotopic liver transplantation.

Distinction between recurrent and de novo hepatocellular carcinoma (HCC) after orthotopic liver transplantation (OLT) bears important clinical and therapeutic implications. Techniques for molecular profiling of clinically suspected de novo and recurrent HCC are required since the histological/clinical discrimination of donor vs. recipient tumor origin is difficult. Multiple PCR amplification of 16 highly polymorphic short tandem repeat (STR) DNA sequences (routinely used for paternity and forensic assays) was applied in two patients who developed a second HCC after OLT. In both patients the technique provided reliable evidence that the two second HCC were recurrences of the primary tumor. Multiple STR genetic allelotyping is an effective tool for clear-cut discrimination of donor/recipient origin of a second HCC after OLT. Its application could be of great therapeutic relevance for such OLT patients.     

Postnatal development of dopamine receptor expression in rat peripheral blood lymphocytes.

Postnatal development in the expression of dopamine D1-like and D2-like receptors was investigated in peripheral blood lymphocytes of male Wistar rats aged 1, 3, 4, 8, 12 and 16 weeks of age by radioligand binding assay techniques. Sample of frontal cortex, striatum and hippocampus were also investigated as reference tissues. The dopamine D1-like receptor antagonist [3H]SCH 23390 and the dopamine D2-like receptor agonist [3H]7-OH-DPAT were used as radioligands. The affinity (K(d)) of [3H]SCH 23390 or of [3H]7-OH-DPAT binding was unchanged in lymphocytes of rats of different age groups. The density (B(max)) of [3H]SCH 23390 binding sites increased from the 1st to the 3rd week of age, remained constant from the 3rd to the 8th week of age, and then increased slightly at 12 and 16 weeks of age. The B(max) value of [3H]7-OH-DPAT binding to lymphocytes increased from the 1st to the 3rd week of age, remained constant from the 3rd to the 4th week, increased again until the 12th week and then plateaued. Dopamine D1-like and D2-like receptor maturation in frontal cortex, hippocampus and striatum revealed an increased receptor density until the 4th week of age and a relative stabilization of receptor density values between the 4th to the 12th week depending on the area considered. Comparatively postnatal maturation of lymphocyte dopamine D1-like receptors displayed a pattern different from that of brain areas investigated, whereas maturation of D2-like receptors displayed a pattern similar to that of striatum. The quantitative and/or qualitative dissimilarities between development of lymphocyte and brain dopamine receptors suggest that from a developmental point of view lymphocyte dopamine receptors probably cannot be considered as a marker of homologous brain receptors.     

Daily versus thrice-weekly interferon alfa-2b plus ribavirin for the treatment of chronic hepatitis C in HIV-infected persons: a multicenter randomized controlled trial

Among HIV-infected persons, chronic hepatitis C virus (HCV) infection causes substantial morbidity and mortality. However, few studies have evaluated the safety and efficacy of interferon alfa (IFN) and ribavirin (RBV) therapy in co-infected persons. Accordingly, a randomized, controlled, open-label, multicenter trial was conducted to establish the safety, tolerability, and efficacy of IFN alfa-2b 3 mIU daily plus RBV 800 mg/d compared with IFN alfa-2b 3 mIU thrice weekly (TIW) plus RBV 800 mg/d in HCV treatment-naive, HIV-infected subjects with compensated liver disease and stable HIV disease. The primary endpoint was sustained virologic response (SVR), defined as an undetectable HCV RNA level 24 weeks after discontinuation of HCV therapy. At study entry, subjects in both groups were similar with respect to age, gender, HCV genotype, and HIV disease status. Of 180 randomized subjects, 162 received at least 1 dose of study medication, constituting the modified intention-to-treat population. After 12 weeks of therapy, 122 (75%) had serum HCV RNA levels assessed; of these subjects, early virologic response (undetectable HCV RNA or >2 log10 decrease from baseline) was observed in 33 (42%) and 13 (16%) of subjects taking daily and TIW IFN, respectively (P < 0.001). SVR was observed in 15 (19.0%) and 7 (8.4%) of subjects taking daily and TIW IFN, respectively (P = 0.05). Adverse events were similar in both groups. However, while no deaths or opportunistic infections were observed, nearly 30% of subjects stopped treatment due to adverse events and 7 subjects experienced a serious adverse event. In conclusion, SVR was achieved in 19% of HIV/HCV coinfected subjects treated with daily IFN plus RBV, but the effectiveness of therapy was substantially diminished by relatively high rates of treatment-related toxicity.