Immunohistochemical staining of Langerhans cells in HPV-positive and HPV-negative cases of oral squamous cells carcinoma

The Human Papillomavirus (HPV) has been strongly implicated in development of some cases of oral squamous cell carcinoma (OSCC). However, the immunological system somehow reacts against the presence of this virus. Among the cells involved in such mechanism of defense Langerhans cells (LC) stand out, which are responsible for processing and presenting antigens. OBJECTIVES: The purposes of this study were to investigate the presence of HPV DNA and to evaluate the immunohistochemical reactivity for Langerhans cells between HPV-positive and HPV-negative OSCC. Twenty-seven cases of OSSC were evaluated. MATERIAL AND METHODS: DNA was extracted from paraffin-embedded tissue samples and amplified by Polymerase Chain Reaction (PCR) for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the Streptavidin-biotin technique. RESULTS: From the 27 cases, 9 (33.3%) were HPV-positive and 18 (66.0%) HPV-negative. HPV 18 was the most prevalent viral type (100% cases) and infection with HPV-16 (co-infection) was detected in only 1 case. In the OSCC specimens examined, immunoreactivity to S-100 antibody was detected in all cases, with a mean number of 49.48±30.89 Langerhans cells positive for immunostaining. The mean number of immunostained Langerhans cells was smaller in the HPV-positive cases (38 cells/case) than in the HPV-negative cases (42.5 cells/case), but this difference was not significant (p=0.38). CONCLUSIONS: The low frequency of detection of HPV DNA in OSCC indicates a possible participation of the virus in the development and progression of only a subgroup of these tumors. There was no association between the immunohistochemical labeling for Langerhans cells (S-100+) and HPV infection of in OSSC. These findings suggest that the presence of HPV in such OSCC cases could not alter the immunological system, particularly the Langerhans cells

Proximate analysis. Fatty acid profiles and mineral contents of meats: A comparative study

The aim of this study was to compare chemical parameters, fatty acid composition and mineral contents of farm animal meats which are marketed in Turkey. Different kinds of meats were purchased from the meat market including beef, lamb, broiler, turkey, ostrich and quail meat, which are mostly preferred for different reasons by consumers. However, little information exists about the composition of meats of different farm animal species. The results of proximate analysis showed that the high level of protein (24.38%) and low level crude fat (1.19 ± 0.13%) were found in turkey meats, while the low level of protein (18.75%) and high level fat (8.79%) were found in lamb meats. The fatty acid compositions of meats were in the range of 22.68-48.37% for saturated, 21.38-42.45% for monounsaturated and 3.75-47.47% for polyunsaturated acids. The highest micro mineral was determined as zinc (5.7417 ppm) in lamb and ostrich (5.0923 ppm). Practical Applications: Consumers attitudes toward meat " safety" greatly affect their overall choices and the variety of meat types available for sale. Some meats are more likely to cause heart disease - saturated fats and trans fats. These fats are usually found in foods from animals such as meat milk, cheese and butter. The dietary saturated fatty acids elevate serum cholesterol concentrations, whereas polyunsaturated fatty acids reduce serum cholesterol concentrations and monounsaturated fatty acids have little or no effect. Therefore, knowledge concerning the exact fatty acid composition of the meat is extremely important for the consumer and processing sector. This study provides comparative information to consumer and processing sector about proximate and fatty acid compositions and mineral contents of beef, lamb, broiler, turkey, ostrich and quail meats. © 2010, Wiley Periodicals, Inc

Can mycoplasma contribute to formation of prostate cancer?

To reveal the possible role of mycoplasmas in the etiopathogenesis of prostate cancer

Identification of gram-negative bacteria from critical control points of raw and pasteurized cow milk consumed at Gondar town and its suburbs, Ethiopia

<p>Abstract</p> <p>Background</p> <p>Milk is highly prone to contamination and can serve as an efficient vehicle for human transmission of foodborne pathogens, especially gram-negative bacteria, as these are widely distributed in the environment.</p> <p>Methods</p> <p>This cross-sectional study of gram-negative staining bacterial contamination of milk meant for human consumption was carried out from October 2010 to May 2011 in Gondar town, Ethiopia. Milk samples were collected from critical control points, from production to consumption, that were hypothesized to be a source of potential contamination. Milk sampling points included smallholder’s milk producers, dairy co-operatives, a milk processing plant, and supermarkets. The hygienic procedures applied during milking, milk collection, transportation, pasteurization, and postpasteurization storage conditions at these specified critical control points were evaluated. Standard bacteriological cultivation and biochemical assays were used to isolate and identify bacterial pathogens in the milk samples.</p> <p>Results</p> <p>The results of the current study showed that conditions for contamination of raw milk at different critical points were due to less hygienic practices in pre-milking udder preparation, sub-optimal hygiene of milk handlers, and poor sanitation practices associated with milking and storage equipments. Among all critical control points considered, transportation containers at milk collection centers and at processing plants were found to be the most heavily contaminated with gram-negative staining bacterial species. Overall, 54 different bacterial species were indentified, and <it>Escherichia coli</it> (29.6%), <it>Pseudomonas aeruginosa</it> (18.5%), and <it>Klebsiella pneumoniae</it> (16.7%), were the most commonly identified gram-negative staining bacterial pathogens. Of particular interest was that no gram-negative staining bacteria were isolated from pasteurized milk samples with varying shelf life.</p> <p>Conclusion</p> <p>This study showed the presence of diverse pathogenic gram-negative staining bacterial species in raw milk that may be attributed to the sub-optimal sanitary conditions in the production and processing of milk in the Gondar town region. These results highlighted the need to maintain appropriate sanitary and hygienic measures at each critical point in order to safeguard consumers from foodborne pathogens. Further studies are recommended to identify additional critical control points, and to assess zoonotic risk factors to consumers.</p