Prevalence of hepatitis B virus DNA in anti-HBc-positive/HBsAg-negative sera correlates with HCV but not HIV serostatus.

BACKGROUND: Hepatitis B virus (HBV) DNA often remains detectable in serum despite clinical recovery and loss of HBsAg. OBJECTIVE: To study whether coinfection with HIV and HCV influence the chance of detecting HBV DNA in sera with markers of past hepatitis B. STUDY DESIGN AND RESULTS: The test panel included 160 anti-HBc-positive/HBsAg-negative sera collected in the diagnostic setting. The following parameters were determined in the sera: anti-HIV (32% positive), anti-HCV (34% positive), HCV RNA (18% positive), and anti-HBs (37% positive). A highly sensitive PCR (90%-detection limit 100 copies/ml) amplifying the terminal protein (TP) region of HBV was established and HBV DNA was detected in 12.5% of the samples. In 70% of these samples, the HBV DNA concentration was below 500 copies/ml as measured by real-time PCR in the S gene. Logistic regression analysis revealed that the chance of detecting HBV DNA was increased by a positive HCV serostatus (odds ratio 5.0, 95%-CI 1.6-15.7), whereas HIV coinfection (odds ratio 2.0, 95%-CI 0.7-5.8), anti-HBs (odds ratio 0.9, 95%-CI 0.3-2.6), and HCV RNA status (odds ratio 0.4, 95%-CI 0.1-1.7) had no statistically significant influence. In contrast, the chance of detecting HCV RNA in the subgroup of anti-HCV-positive sera was increased by HIV coinfection (odds ratio 4.5, 95%-CI 1.2-17.4). Sequencing of the TP PCR products revealed neither a specific phylogenetic origin of the circulating HBV DNA nor clustering of uncommon mutations in the TP region. CONCLUSIONS: The prevalence of HBV DNA in serum of anti-HBc-positive/HBsAg-negative subjects correlates with HCV rather than HIV serostatus.     

HPA polymorphism in sub-Saharan African populations: Beninese, Cameroonians, Congolese, and Pygmies

The frequency of human platelet antigen-1 (HPA-1) to HPA-11w (excluding HPA-8w) and HPA-15 systems was studied in four sub-Saharan populations: Beninese, Congolese (Democratic Republic of Congo Kinshasa), Cameroonians, and Aka pygmies (Central African Republic). No report of HPA prevalence has previously been published concerning these populations which are characterized by the highest HPA-2b gene frequencies of any reported to date (Aka 0.393, Benin 0.292, Cameroon 0.237, and Congo 0.224) and at lesser degree HPA-5b (Aka 0.405, Congo 0.268, Cameroon 0.254, and Benin 0.182). This study is of great importance (i) particularly in the context of the diversity caused by the population migrations, we may observe today in our hospitals (ii) to confirm that the Pygmy population with distinctive frequencies (absence of the HPA-1b, HPA-2b, and HPA-5b highest frequencies) is an isolated population.     

Herbal remedies and their adverse effects in Tem tribe traditional medicine in Togo

In Africa, up to 80% of the population relies on herbal concoctions for their primarily health care. In Togo, western Africa, Tem tribe is a population with old knowledge of medicinal plants, however, still very little is known about their medical practices. The present study was conducted to access for the apprehension of adverse effects of traditional remedies by Tem traditional healers (TH). Enquiry was performed by interviews with healers from August to October 2007 in Tchaoudjo prefecture (Togo). The study allowed us to interview 54 TH including 41(75.93%) males and 13(24.07%) females, who cited 102 recipes assumed to have adverse effects. The recipes were used alone to cure several diseases including haemorrhoids (22.55%), female sexual disorders and infertility (21.57%), gastrointestinal disorders (18.63%), and malaria (6.86%). A total of 34 plants belonging to 21 families were cited to be components of the recipes. Euphorbiaceae and Mimosaceae families were the most represented, however, Nauclea latifolia, Khaya senegalensis, Pseudocedrela kotschyi and Xeroderris stuhlmannii were the main components of recipes linked to adverse effects. A total of 20 adverse effects were linked to the administration of theses drugs, and among them; diarrhoea, abdominal pains, polyuria, general weakness and vomiting were the most frequently encountered. These findings were in accordance with several reports of the literature concerning medicinal plants, although they were based on empirical observations. Laboratory screenings are needed to access for the effectiveness as well as the possible toxic effects of the recipes.     

Module based antibody engineering: a novel synthetic REDantibody

We describe the facile generation of a stable recombinant antibody with intrinsic red fluorescent properties for qualitative and potentially quantitative immunofluorescence analysis. The REDantibody based on the X-ray crystallographic structures of the anti-sialyl-Tn antibody B72.3 and 3D model of the monomeric red fluorescent protein was designed to retain optimal spatial geometry between the C- and N-termini of the V(H) and V(L) chains respectively to mimic the domains interface pairing in antibody Fab fragments and to incorporate the red fluorescent protein as a bridging scaffold. The model was further validated by assembling a REDantibody based on CA19.9 the anti-sialylated Lewis (Le)(a) blood group antigen and 4D5-8 the anti-p185(HER2) antibodies. The chimeric heavy and light chains containing red fluorescent protein as a bridge were correctly processed and secreted into Escherichia coli periplasm for assembly and disulphide bond formation, further analysis revealed the molecules to be exclusively monomers. Purified anti-glycan proteins were used for an immunofluorescent analysis of Trypanosoma cruzi epimastigotes, and the anti-p185(HER2) used to determine the binding properties. The REDantibody platform facilitates rapid generation of scFv chimeras that could be used for screening antibodies against cell surface markers. Furthermore, such modular assembly should permit the interchange of binding sites and of fluorophores to create robust panels of coloured antibodies.     

New mutations on platelet GPIIb in Sub-Saharan African populations revealed by genotyping discrepancies

BACKGROUND: Previous studies of platelet allele frequencies in Sub-Saharan African populations enabled us to identify discrepancies in HPA-3 typing, suggesting the presence of new mutations and of a greater polymorphism than so far described in other populations. OBJECTIVES: To analyze these discrepancies and to assess the factors leading to potential alloimmunization in these populations. MATERIALS AND METHODS: Samples: Maternal samples from a Beninese woman following in utero death and panels of blood donors from Benin, Cameroon, Congo, and Pygmies from Central Africa. Techniques: Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), PCR-sequence specific primers (PCR-SSP) and sequencing techniques. RESULTS: Three new mutations were found on GPIIb gene: exon 26 a) 2614C>A situated between HPA-3 and HPA-9w, b) 2645C>T downstream of HPA-3, c) intron 26 IVS26+89G>A. These mutations may lead to discrepant DNA typing results, due either to a localization in the complementary sequence recognized by the primer or to the appearance of a new enzyme restriction site. Furthermore, a bilateral linkage < deletion (Delta9 bp) intron 21 and the HPA-3b allele (exon 26) > found in Caucasian, Asian, and Oceanian populations is not found in African populations, suggesting that its appearance was prior to HPA-3. CONCLUSION: Three new mutations have been identified, two of them potentially immunogenic through their position. Furthermore, the polymorphism found on intron 26, localized in the complementary sequence of the PCR primer, may lead to a false typing assignation. It is therefore important to diversify techniques, both genomic (PCR-RFLP and PCR-SSP), and proteomic monoclonal antibody-specific immobilization of platelets antigen (MAIPA) to ensure accurate HPA antigenic system typing.     

Paradoxical lipodystrophic changes due to conventional bovine and highly purified porcine/bovine insulins

A 78-year-old woman developed marked insulin lipoatrophy due to conventional bovine insulin injected into the upper limbs. Changing to a combination of highly purified porcine/bovine insulins injected into the lower limbs resulted in the opposite effect, namely insulin-induced lipohypertrophy. Use was then made of this effect by injecting the highly purified insulins into the atrophied upper limb injection sites with resultant improvement in these wasted areas over the next 10 months.