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.     

Characterization of 17B-hydroxysteroid dehydrogenase isoenzyme expression in benign and malignant human prostate

In the present study, expressions of 17B-hydroxysteroid dehydrogenase (17HSD) types 1, 2 and 3, 5α-reductase type 2 and human androgen receptor mRNAs were determined in 12 benign prostatic hyperplasia and 17 prostatic carcinoma specimens. 17HSD type 2 was found to be the principal isoenzyme expressed in the prostate. Significantly higher expressions of 17HSD type 2 and 5α-reductase type 2 were detected in benign prostatic hyperplasia compared with the carcinoma specimens. Expression of the androgen receptor in the 2 groups was not significantly different. 17HSD type 3 mRNA was not detected in any of the specimens investigated. Only low constitutive expression of the 2.3 kb mRNA of 17HSD type I was seen. Immunohistochemical analyses indicated that this did not lead to significant enzyme expression, only faint staining for the enzyme protein being detected, mainly in uroepithelial cells. No significant correlation was found between any of the mRNAs analyzed, but the data on 5α-reductase type 2 mRNA support the presence of an increased proportion of 5α-dihydrotesterone in the hyperplastic prostate. In cultured PC-3 prostatic cancer cells and in transiently transfected human embryonic kidney 293 cells, 17HSD type 2 was found exclusively to convert 5α-dihydrotestosterone and testosterone into the less potent 17-keto compounds 5α-androstanedione and 4-androstenedione, respectively. We suggest that the 17HSD type 2 isoenzyme plays a part in the metabolic pathway, resulting in the inactivation of testosterone and 5α-dihydrotestosterone locally in the prostate. The enzyme expressed in the prostate could, therefore, protect cells from excessive androgen action. © 1996 Wiley-Liss, Inc.     

Odontogenic tumors: a review of 319 cases in a Nigerian teaching hospital

OBJECTIVE: This study sought to determine the relative frequency of odontogenic tumors in a Nigerian population and to compare these data with previous reports. STUDY DESIGN: Records of patients seen at the Lagos University Teaching Hospital between January 1980 and December 2003, with histologic diagnosis of odontogenic tumors (based on World Health Organisation classification, 1992), were analyzed. RESULTS: Odontogenic tumors constituted 9.6% of all the biopsies of oral and jaw lesions seen within the period under study. Three hundred and eight (96.6%) were intraosseous, and 11 (3.4%) were peripheral (peripheral odontogenic fibroma=7; peripheral myxoma=3; peripheral ameloblastoma=1). The mean age of patients was 29.9+/-15.6 years (range, 4-85 years). Among these cases, 96.6% of the tumors were benign and 3.4% were malignant. Ameloblastoma with predilection for the mandible was the most frequent odontogenic tumor (63%), followed by adenomatoid odontogenic tumor (AOT) (7.5%), myxoma (6.5%), calcifying epithelial odontogenic cyst (5.3%), and odontogenic fibroma (5.3%). More cases of malignant odontogenic tumors were seen than cases of calcifying epithelial odontogenic tumor and odontomas. The mean ages of patients with AOT, ameloblastic fibroma, and odontoma were significantly lower than those with ameloblastoma ( P<.05). No significant difference was found between the mean ages of patients with benign odontogenic tumors and those with malignant odontogenic tumors ( P=.058). CONCLUSIONS: Odontogenic tumors, especially ameloblastoma, are not considered rare among Nigerians, whereas odontoma, regarded as the most frequent odontogenic tumor in North and South America, is rare.     

Gastroesophageal reflux in infants < 32 weeks gestational age at birth: lack of relationship to chronic lung disease

The objective of this study was to determine the incidence of gastroesophageal reflux (GER) as documented by extended esophageal pH monitoring in symptomatic premature infants and to identify its relationship with chronic lung disease (CLD). This was a retrospective study of 629 infants born < 32 weeks gestational age and admitted to the neonatal intensive care unit during the study period. Univariate analyses were done on the 137 infants undergoing the test for the association of the following risk factors with acid reflux: birth weight, gestational age, race, sex, length of stay, bronchopulmonary dysplasia (BPD; O2 requirement at 28 days), and severe CLD (O2 requirement at 36 weeks postmenstrual age). Eighty-seven of 137 infants were positive for GER. There was no association of GER with the risk factors studied, nor were there correlations with BPD or severe CLD. GER is common (63%) in premature infants < 32 weeks gestational age but clinical symptoms and CLD are poorly correlated with this diagnosis.     

The effect of the cyclooxygenase blockers,ibuprofen on the development of glomeruli in Sprague-Dawley rats

Cyclo-oxygenase mediated prostaglandins are important determinants of glomerular development and kidney function. Ibuprofen inhibit the enzyme cyclo-oxygenase and thereby block the prostaglandin synthesis in the kidneys. Cyclo-oxygenase exist in two iso-forms (COX-1 and COX-2). It has ben proposed that Non-steroidal anti-inflammatory drugs (NSAIDs) with preferential COX-2 selectivity have fewer renal side effects than drugs with preferential COX-1 selectivity. The significance of this remains unclear since nephrotoxicity is relatively uncommon with ibuprofen and, when present is usually rapidly reversible although, ibuprofen has a higher potency against COX-1 than COX-2. We therefore investigated the effect of ibuprofen on glomerulogenesis in Sprague-Dawley rats. Ibuprofen (22 mg/kg/day) was administered orally from day 10 of gestation to day 15 after parturition. Light microscopic examination of ibuprofen-treated neonatal kidneys show hypoplastic glomeruli. These results suggest that low dose ibuprofen is deleterious to glomerular development.     

A retrospective study of prevalence of antibody to HIV in blood donors at Ile-Ife, Nigeria

Records of voluntary and remunerative blood donors bled at the OAUTHC, Ile-Ife, Nigeria between January 1993 and December 2000 were reviewed for HIV sero-positivity. With a structured questionnaire, and over a period of 2 months, the attitudes and awareness of some of the donors of HIV/AIDS epidemic in the country were also assessed. Of the 16,080 units of blood collected in the period under review, only 1073(6.7%) were obtained from voluntary donors. The cumulative HIV seroprevalence rate was 2.1% in the paid donors as against 0.3% in the voluntary donors (c2 = 16.3, df = 1, p = 0.00003). Sixty-five (805) of the donors interviewed confirmed previous knowledge of HIV/AIDS before the interview. All the respondents appreciated the roles of blood transfusion in the transmission of AIDS viruses. The majority (74%) of the respondents were unemployed. Poverty was the reason given by 61(75%) of the commercial donors for selling their blood. We conclude that there is a greater risk of transmitting AIDS viruses (and possibly other blood transmissible diseases) through remunerated blood donors.