Ameloblastoma: analysis of 207 cases in a Nigerian teaching hospital.

OBJECTIVE: The aim of the study was to review all the cases of ameloblastoma seen at the Oral and Maxillofacial Surgery Clinic of the Lagos University Teaching Hospital, Nigeria, between 1980 and 2003. METHODS AND MATERIALS: In this retrospective study, case files and biopsy reports of new cases of ameloblastoma covering a 24-year period were retrieved and analyzed for sex, age on presentation, histologic type, and site distribution. RESULTS: A total of 207 cases of ameloblastoma were seen in the given period. One hundred and ninety-eight (95.7%) were benign, and 9 (4.3%) were malignant. A male-to-female ratio of 1.1:1 was found. The average ages on presentation for ameloblastoma and ameloblastic carcinoma were 31.67 and 46.44 years, respectively. The lesion was found to be more common in the premolar-molar region of the mandible. The most common histologic type was follicular ameloblastoma (25.1%). Nine (4.3%) cases of ameloblastic carcinoma were also reported. CONCLUSIONS: Ameloblastoma with a predilection for the posterior mandibular region is relatively common in our environment. Sex and site distributions are similar to previous reports in the literature.     

Demonstration of factor H-like protein 1 binding to Treponema denticola, a pathogen associated with periodontal disease in humans

Treponema denticola is an important contributor to periodontal disease. In this study we investigated the ability of T. denticola to bind the complement regulatory proteins factor H and factor H-like protein 1 (FHL-1). The binding of these proteins has been demonstrated to facilitate evasion of the alternative complement cascade and/or to play a role in adherence and invasion. Here we demonstrate that T. denticola specifically binds FHL-1 via a 14-kDa, surface-exposed protein that we designated FhbB. Consistent with its FHL-1 binding specificity, FhbB binds only to factor H recombinant fragments spanning short consensus repeats (SCRs) 1 to 7 (H7 construct) and not to SCR constructs spanning SCRs 8 to 15 and 16 to 20. Binding of H7 to FhbB was inhibited by heparin. The specific involvement of SCR 7 in the interaction was demonstrated using an H7 mutant (H7AB) in which specific charged residues in SCR 7 were replaced by alanine. This construct lost FhbB binding ability. Analyses of the ability of FHL-1 bound to the surface of T. denticola to serve as a cofactor for factor I-mediated cleavage of C3b revealed that C3b is cleaved in an FHL-1/factor I-independent manner, perhaps by an unidentified protease. Based on the data presented here, we hypothesize that the primary function of FHL-1 binding by T. denticola might be to facilitate adherence to FHL-1 present on anchorage-dependent cells and in the extracellular matrix.     

FDA evaluations using in vitro metabolism to predict and interpret in vivo metabolic drug-drug interactions: impact on labeling.

Recent advances in in vitro metabolism methods have led to an improved ability to predict clinically relevant metabolic drug-drug interactions. To address the relationships of in vitro metabolism data and in vivo metabolism outcomes, the Office of Clinical Pharmacology and Biopharmaceutics in the Center for Drug Evaluation and Research, Food and Drug Administration, evaluated a number of recently approved new drug applications. The goal of these evaluations was to determine the contribution of in vitro metabolism data in (1) predicting in vivo drug-drug interactions, (2) determining the need to conduct an in vivo drug-drug interaction study, and (3) incorporating findings into drug product labeling. Ten cases are presented in this article. They fall into two major groups: (1) in vitro data were predictive of in vivo results, and (2) in vitro data were not predictive of in vivo results. Discussion of these cases highlights factors limiting predictability of in vivo metabolic interactions from in vitro metabolism data. The integration of these findings into drug product labeling is also discussed.     

Prevalence of hepatitis B surface antigen among patients suspected of liver diseases in a Nigerian hospital

Hepatitis B virus (HBV) infection has been reported to be the aetiological factor for hepatocellular carcinoma (HCC), hepatitis and liver cirrhosis. This study was therefore carried out to determine the seroprevalence of hepatitis B surface antigen (HBsAg), a specific marker of HBV infection in patients with suspected liver diseases. The investigation was carried out among patients attending the University of Maiduguri Teaching Hospital (UMTH), Nigeria with clinical symptoms suggestive of liver diseases and others with non-specific clinical features during the period from 1990-1995. A total of 197 (38%) of 517 patients tested positive for HBsAg, 81 (49%) out of 144 with symptoms suggestive of hepatitis, 75 (50%) of 149 HCC and 10 (56%) of 18 liver cirrhosis were HBsAg positive. Comparison of the yearly total prevalence values of HBsAg for the six years under study showed no significant difference. Similarly, yearly prevalence values amongst patients with suspected liver diseases showed no significant differences. Nevertheless, significant difference, (P < 0.05) between the prevalence of HBsAg among suspected cases of liver diseases and others with non-specific signs and symptoms was observed. Similarly, HBsAg was statistically significantly higher among males than females. The high prevalence rate of HBsAg in our environment may be associated with the suspected cases of liver diseases, which are equally prevalent in our locality. Health education to prohibit traditional practices that could predispose individuals to HBV infections is emphasised. The incorporation of HBV vaccination in the national programme on immunization currently in use in Nigeria is highly recommended. This would be an effective method of preventing HBV infection from childhood.     

Spatial learning in a virtual reality-based task is altered in very preterm children

Very preterm births prevent a complete development of the nervous system. The hippocampus is especially vulnerable in this population since the perinatal period is critical for its growth and development. Learning and memory abilities, like spatial memory, depend on the hippocampal integrity. In this study we applied virtual-reality-based tasks to assess spatial memory in a sample of 20 very preterm children of 7 and 8 years of age. Two different conditions of difficulty were used. Very preterm children performed poorly in the task in comparison with the control group. They committed more errors than controls searching for the rewarded positions. However, no significant differences were observed in the mean speed, an index of the motor abilities and joystick handling. These results suggest that the hippocampal function is affected in this sample. Nevertheless, other variables to consider are discussed.     

What Promotes Cervical Cancer Screening Among Chamorro Women in California?

Pacific Islander women represent a significant at-risk population for cervical cancer, yet little is known about the modifiable factors associated with routine Pap testing. Therefore, the aims of this paper are to report and discuss the known and unknown factors associated with cervical cancer screening among Chamorro women in California. This cross-sectional study explored the factors associated with receipt of regular Pap testing among Chamorro women age 18 years and older in California. A self-administered survey was designed and distributed to women in order to understand their knowledge, beliefs and behaviors regarding routine receipt of Pap tests. Only about two-thirds of women had received a Pap test within the past 2 years, which is below the U.S. average of 72 %. Significant predictors included younger age, health insurance coverage, knowledge of screening frequency, and medically correct beliefs regarding risk groups. These factors, however, accounted for less than 16 % of the variance in Pap testing behavior. We discuss the poor predictive value of existing demographic and theoretical variables, and discuss potentially new areas of research that can aid in the development of future intervention studies. Study limitations and implications are also discussed.