Comparative assessment of seller’s staining test (SST) and direct fluorescent antibody test for rapid and accurate laboratory diagnosis of rabies.

Background: Rabies causes 55, 000 annual human deaths globally and about 10,000 people are exposed annually in Nigeria. Diagnosis of animal rabies in most African countries has been by direct microscopic examination. In Nigeria, the Seller’s stain test (SST) was employed until 2009. Before then, both SST and dFAT were used concurrently until the dFAT became the only standard method. Objective: This study was designed to assess the sensitivity and specificity of the SST in relation to the ‘gold standard’ dFAT in diagnosis of rabies in Nigeria. Methods: A total of 88 animal specimens submitted to the Rabies National Reference Laboratory, Nigeria were routinely tested for rabies by SST and dFAT. Results: Overall, 65.9% of the specimens were positive for rabies by SST, while 81.8% were positive by dFAT. The sensitivity of SST in relation to the gold standard dFAT was 81.0% (95% CIs; 69.7% - 88.6%), while the specificity was 100% (95% CIs; 76% - 100%). Conclusion: The relatively low sensitivity of the SST observed in this study calls for its replacement with the dFAT for accurate diagnosis of rabies and timely decisions on administration of PEP to prevent untimely deaths of exposed humans.

Immunoregulation in human malaria: the challenge of understanding asymptomatic infection

Asymptomatic Plasmodium infection carriers represent a major threat to malaria control worldwide as they are silent natural reservoirs and do not seek medical care. There are no standard criteria for asymptomatic Plasmodium infection; therefore, its diagnosis relies on the presence of the parasite during a specific period of symptomless infection. The antiparasitic immune response can result in reduced Plasmodium sp. load with control of disease manifestations, which leads to asymptomatic infection. Both the innate and adaptive immune responses seem to play major roles in asymptomatic Plasmodium infection; T regulatory cell activity (through the production of interleukin- 10 and transforming growth factor-β) and B-cells (with a broad antibody response) both play prominent roles. Furthermore, molecules involved in the haem detoxification pathway (such as haptoglobin and haeme oxygenase-1) and iron metabolism (ferritin and activated c-Jun N-terminal kinase) have emerged in recent years as potential biomarkers and thus are helping to unravel the immune response underlying asymptomatic Plasmodium infection. The acquisition of large data sets and the use of robust statistical tools, including network analysis, associated with welldesigned malaria studies will likely help elucidate the immune mechanisms responsible for asymptomatic infection.

Structural determination and gynecological tumor diagnosis using antibody chip captured proteins

Purpose: To identify markers for gynecological tumor diagnosis using antibody chip capture. Methods: Marker proteins, including cancer antigen 153 (CA153), CA125, and carcinoembryonic antigen (CEA), were analyzed using antibody chip capture of serum samples. Fifteen agglutinin types that specifically recognized five common glycans (fucose, sialic acid, mannose, N - acetylgalactosamine, and N-acetylglucosamine) were used to detect marker protein glycan levels. The levels of CA153, CA125, and CEA from 49 healthy control samples, 31 breast cancer samples, 24 cervical cancer samples, and 19 ovarian cancer samples were used to measure the glycan levels of these marker proteins. Results: In breast cancer samples, CA153 and CA125 were down-regulated (p < 0.01), while differences in ovarian cancer samples were not statistically significant (p > 0.01). The total accuracy was 85.1 %, with 96.8 % accuracy for breast cancer, 75 % in cervical cancer, and 78.9 % in ovarian cancer. Cross-validation analyses showed that breast cancer had 93.5 % accuracy, cervical cancer was 66.7 %, and ovarian cancer was 68.4 %, leading to 78.4 % total accuracy (58/74). Conclusions: The results indicate that better clinical diagnosis of gynecological tumors can be obtained by monitoring changes in glycan levels of serum proteins and types of proteoglycan changes.