Predictors and Barriers to Condom Use in the African Cohort Study

Consistent condom use is an inexpensive and efficacious HIV prevention strategy. Understanding factors associated with condom use and barriers to use can inform strategies to increase condom uptake. The ongoing African Cohort Study prospectively enrolls adults at 12 clinical sites in Uganda, Kenya, Tanzania, and Nigeria. At enrollment, participants are asked about condom use at last sex with a regular partner. Robust Poisson regression models were used to evaluate predictors of self-reported condom use. Participants who reported not using condoms were asked to provide reasons. From January 2013 to September 2019, 2482 participants reported having at least one regular sexual partner in the preceding 6 months. Of those, 1577 (63.5%) reported using a condom at last sex. Condom use was more common among older participants, males, HIV-infected participants, and those with an HIV-infected partner. Married participants, those with a partner of unknown HIV status, and those reporting alcohol use were less likely to report condom use at last sex. Condom use at last sex also varied significantly by clinical site. Partner disapproval or refusal to use a condom was a consistent driver of disparities in condom use among participants who were HIV infected, female, and aged 18-24 years. Effective HIV prevention programs should integrate condom education with the tools necessary to negotiate condom use with regular partners.

Comparison of MICRO-ID Listeria Method with Conventional Biochemical Methods for Identification of Listeria Isolated From Food and Environmental Samples: Collaborative Study

Fourteen laboratories participated in a collaborative study to evaluate the ability of the MICRO-ID Listeria identification method to correctly identify Listeria isolated from food and environmental sources. Each collaborator received 60 isolates consisting of 51 Listeria and 9 non-Listeria cultures. All isolates were identified by conventional biochemical analyses in the principal laboratory. Cultures were checked for purity by Gram staining and examined for oxidase and catalase activities. Only Gram positive, oxidase negative, catalase positive cultures were tested with the method. Colonies from trypticase soy agar with 0.6% yeast extract were suspended in 4.6 ml_ physiological saline to a MacFarland No. 1 turbidity standard and used to inoculate the test strip. In addition, the hemolytic reaction of each isolate was determined by using the Christie-Atkins-Munch-Peterson (CAMP) test and by stabbing sheep blood agar. Identification of Listeria is based on the octal code obtained from the strip and the hemolytic reaction of the isolate. The MICRO-ID Listeria method agreed with conventional biochemical identification for 98.0% of L. monocytogenes, 77.1% of L. seeligeri, 98.0% of L ivanovii, 96.4% of L. grayi/L. murrayi, 73.9% of L. welshimeri, and 100% of L innocua isolates. A large percentage of errors in identification of the L. seeligeri and L ivanovii cultures was caused by inaccurate reading of the CAMP and hemolysis tests rather than errors in the test strip. The method was adopted first action by AOAC International.

Evaluation of VIDAS® Listeria species Xpress (LSX) Immunoassay Method for the Detection of Listeria species in Foods: Collaborative Study

In a multilaboratory study, the effectiveness of an alternative method for rapid screening of Listeria species compared to traditional reference methods was demonstrated in a variety of food products. A collaborative study was conducted to compare the VIDAS® Listeria species Xpress (LSX) method and the standard cultural methods for the detection of Listeria species in foods. Six food types were tested: vanilla ice cream, cheddar cheese, raw ground beef, frozen green beans, deli turkey, and cooked shrimp. Each food, inoculated with a different Listeria strain at two levels and uninoculated test portions, was analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study 1134 tests were analyzed in the statistical analysis. There were 490 positives by the VIDAS LSX method using the sample boiling step, 483 positives by the VIDAS LSX method using the Heat and Go system, and 439 positives by the standard culture methods. Overall, the Chi-square result for the VIDAS LSX method with boiling for all foods was 7.25, indicating a significant statistical difference between the VIDAS method and the standard methods at the 5% confidence. For the VIDAS LSX method with the Heat and Go system, the Chi-square result for all foods was 5.37, indicating a significant statistical difference between the VIDAS LSX assay with the Heat and Go system and the standard methods at the 5% level of significance. In both cases, the VIDAS method was more sensitive than the standard methods. The LSX method detects Listeria species in foods with negative or presumptive positive results in a minimum of 30 h compared to at least 5 days for the cultural methods. Based on the results of this collaborative study, it is recommended that the VIDAS LSX method be adopted as an AOAC Official MethodSM for the detection of Listeria species in dairy products, vegetables, seafood, raw meats and poultry, and processed meats and poultry.

Comparison of the Reveal 20-Hour Method and the BAM Culture Method for the Detection of Escherichia coli O157:H7 in Selected Foods and Environmental Swabs: Collaborative Study

Four different food types along with environmental swabs were analyzed by the Reveal for E. coli O157:H7 test (Reveal) and the Bacteriological Analytical Manual (BAM) culture method for the presence of Escherichia coli O157:H7. Twenty-seven laboratories representing academia and private industry in the United States and Canada participated. Sample types were inoculated with E. coli O157:H7 at 2 different levels. Of the 1095 samples and controls analyzed and confirmed, 459 were positive and 557 were negative by both methods. No statistical differences (p <0.05) were observed between the Reveal and BAM methods.

Reveal 8-Hour Test System for Detection of Escherichia coli O157:H7 in Raw Ground Beef, Raw Beef Cubes, and Iceberg Lettuce Rinse: Collaborative Study

Five different food types were analyzed by the Reveal for E. coli O157:H7 8-Hour Test System (Reveal 8) and either the U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM) culture method or the U.S. Department of Agriculture Food Safety Inspection Service (FSIS) culture method for the presence of E. coli O157:H7. A total of 27 laboratories representing academia and private industry in the United States and Canada participated. Food types were inoculated with E. coli O157:H7 at 2 different levels: a high level where predominantly positive results were expected, and a low level where fractional recovery was anticipated. During this study, 1110 samples and controls were analyzed by both the Reveal 8 and by BAM or FSIS by each of the collaborators (2220 samples in total). For each set of samples, 740 were artificially inoculated with E. coli O157:H7, and 370 were uninoculated controls. The Reveal 8 detected 528 presumptive positives of which 487 were confirmed positive by the BAM culture method. In comparison, BAM and FSIS detected 489 of the 740 artificially contaminated samples as positive. In an additional in-house study performed only on chilled and frozen raw ground beef, 240 artificially inoculated samples were analyzed by both the Reveal 8 and by FSIS. The Reveal 8 detected and confirmed 104 samples as positive compared to 79 confirmed positive by FSIS.

Brain weights in adult africans

Introduction: The average brain weight of adult humans, using Caucasian figures, is said to be between 1300g to 1400g. Few studies have however been done to make actual evaluations of brain weights in adult Africans. This study seeks to examine the weight of brains from people of African descent with respect to variations in sex and age in decades using autopsy specimens. Materials and Methods: Analysis of the weight of brains removed from both male and female adult patients during fresh autopsy of their bodies in our center over a ten year period was done. The study criteria required non-involvement of the central nervous system in the cause of death. The brains were grouped based on age in decades and further grouped into early, middle and late age groups. Descriptive statistical analysis was done using SPSS 20 statistics software. Results: A total of one hundred and sixteen brains were included in the study and the mean brain weight was 1280g with a range between 1015g to 1590g. There was no statistically significant difference in the mean brain weight of the different age groups. The average male brain was heavier than those of females and the difference was statistically signiicant. Conclusion: The brain weight of adult Africans in our study is similar to that seen in Caucasians. There is no statistically significant difference in the brain weight of adults from early adulthood to the elderly adults. Male adults have statistically heavier brains than the females.

Correlation of intraoperative cytological and final histological diagnoses: a retrospective 10-year study of neurosurgical cases from Ibadan, Nigeria

OBJECTIVE

Intraoperative cytology is a cost-effective, rapid, and easy technique, and studies have shown good correlation between intraoperative cytology and histology. We undertook this study to compare the intraoperative cytology diagnoses of brain lesions made in our unit over a 10-year period with the definitive histological diagnoses. The aim was to determine the degree of accuracy of this procedure.

STUDY DESIGN

This is a retrospective study of intraoperative neuropathology consultation cytology smears or imprints and histology of 69 cases obtained over a 10-year period. Cytology smears were stained using both Papanicolaou and Giemsa. Histology sections were prepared from routine formalin-fixed paraffin-embedded tissue and stained using H and E method. Each of the smears and histology samples were assessed by at least two pathologists. Cytological diagnosis was correlated with final histological diagnosis. The sensitivity and specificity of cytological diagnosis was evaluated using final histological diagnosis as gold standard.

RESULTS

Correlation was strongest with inflammatory lesions followed by low-grade neoplasms. High-grade neoplasms also showed good concordance, but the degree of correlation was lower than in the other categories. Misdiagnosis was commonest with benign tumors.

CONCLUSION

Intraoperative cytology is a relatively simple, reliable, and accurate diagnostic technique and should be more commonly used, particularly in low-resource settings.

Small intestinal pathology

During the past year, important studies on various mechanisms of small bowel disease have been reported. The section on enterocyte function evaluates studies on hypoxia and apoptosis. Many of the studies of small intestinal epithelia use as models T84 cells. When these cells are referred to as intestinal cells, it may be in a general sense. This may be of relevance in permeability studies because the transepithelial resistance of T84 cells is on the order of 1000 to 2000 ohm.cm, much higher than the resistance of the small intestine. These studies produce added insights into cellular function. Hypoxia causes changes in epithelial permeability through autocrine pathways. Additional studies methodically detail apoptosis in the small intestinal cell caused by ischemia-reperfusion and the potential mechanisms. Apoptosis is also important in graft-versus-host disease. A number of studies of the mechanism of action of Clostridium difficile toxins are reviewed; these may have therapeutic implications in the future. Finally, the role of mast cells in immunity and in postischemic inflammation is reviewed.

Trypsin activates pancreatic duct epithelial cell ion channels through proteinase-activated receptor-2

Proteinase-activated receptor-2 (PAR-2) is a G protein-coupled receptor that is cleaved by trypsin within the NH2-terminus, exposing a tethered ligand that binds and activates the receptor. We examined the secretory effects of trypsin, mediated through PAR-2, on well-differentiated nontransformed dog pancreatic duct epithelial cells (PDEC). Trypsin and activating peptide (AP or SLIGRL-NH2, corresponding to the PAR-2 tethered ligand) stimulated both an 125I- efflux inhibited by Ca2+-activated Cl- channel inhibitors and a 86Rb+ efflux inhibited by a Ca2+-activated K+ channel inhibitor. The reverse peptide (LRGILS-NH2) and inhibited trypsin were inactive. Thrombin had no effect, suggesting absence of PAR-1, PAR-3, or PAR-4. In Ussing chambers, trypsin and AP stimulated a short-circuit current from the basolateral, but not apical, surface of PDEC monolayers. In monolayers permeabilized basolaterally or apically with nystatin, AP activated apical Cl- and basolateral K+ conductances. PAR-2 agonists increased [Ca2+]i in PDEC, and the calcium chelator BAPTA inhibited the secretory effects of AP. PAR-2 expression on dog pancreatic ducts and PDEC was verified by immunofluorescence. Thus, trypsin interacts with basolateral PAR-2 to increase [Ca2+]i and activate ion channels in PDEC. In pancreatitis, when trypsinogen is prematurely activated, PAR-2-mediated ductal secretion may promote clearance of toxins and debris.

Na,K-ATPase in diabetic rat small intestine. Changes at protein and mRNA levels and role of glucagon

Na,K-ATPase activity and isoform expression were measured in rat small intestinal mucosa taken from both normal and streptozocin-treated diabetic rats. Enzyme activity and abundance was 1.7-2.3-fold higher in rats diabetic for 2 wk than in controls. This was associated with 1.4-1.7-fold increases in small intestinal protein and DNA content. Ouabain inhibition curves of Na,K-ATPase were monophasic with Kis of 2.6 +/- 1.4 x 10(-4) and 2.0 +/- 1.2 x 10(-4) M for control and diabetic rats, respectively (NS). Northern blot analysis revealed a 2.5-fold increase in mRNA alpha 1 and a 3.4-fold increase in mRNA beta 1 in diabetic rats relative to controls. Two thirds of this increase occurred within 24h after injection of streptozocin. Immunoblots of intestinal enzyme preparations from diabetic and control rats indicated the presence of alpha 1 and beta 1 subunits but not of alpha 2 or alpha 3. Administration of glucagon (80 micrograms/kg) to normal rats daily for 14-16 d increased mRNA alpha 1 3.1-fold but did not increase mRNA beta 1 or enzyme activity. In experimental diabetes, alpha 1 and beta 1 isoforms of Na,K-ATPase are coordinately upregulated at both protein and mRNA levels, an effect which appears to be partially mediated by the associated hyperglucagonemia.

Analysis of autoantibodies to recombinant La (SS-B) peptides in systemic lupus erythematosus and primary Sjogren's syndrome

Autoantibodies to a polymerase III transcription factor, La (SS-B), are frequently detected in the serum of patients with Sjogren's syndrome and systemic lupus erythematosus. To define the humoral immune response to this protein, we analyzed the patterns of antibody recognition toward 13 recombinant La peptides by immunoblotting and determined the heterogeneity of antibodies reactive with the immunodominant epitopes. The smallest epitopes that were strongly antigenic and recognized by greater than 70% of sera tested (immunodominant) were encoded by the subclones BgX and XA located in the 5' and 3' halves of the La cDNA, respectively. Conformation of the immunodominant La peptides played a major role in antibody recognition. Although greater diversity in antibody binding to carboxyl-terminal La peptides was observed, the overall pattern of peptide recognition by anti-La antibodies was similar in different diseases. The antibody responses to the immunodominant peptides were strongly correlated (r = 0.68, P less than 0.001). One- and two-dimensional isoelectric focusing of affinity purified IgG anti-La peptide antibodies revealed restricted heterogeneity and oligoclonal bands (kappa light chains). These observations suggest that anti-La antibodies are induced and/or maintained by the self antigen and that their diversity is constrained either by mechanisms related to tolerance or by affinity maturation of the humoral immune response.