Chorioamnionitis disrupts erythropoietin and melatonin homeostasis through the placental-fetal-brain axis during critical developmental periods.

Introduction: Novel therapeutics are emerging to mitigate damage from perinatal brain injury (PBI). Few newborns with PBI suffer from a singular etiology. Most experience cumulative insults from prenatal inflammation, genetic and epigenetic vulnerability, toxins (opioids, other drug exposures, environmental exposure), hypoxia-ischemia, and postnatal stressors such as sepsis and seizures. Accordingly, tailoring of emerging therapeutic regimens with endogenous repair or neuro-immunomodulatory agents for individuals requires a more precise understanding of ligand, receptor-, and non-receptor-mediated regulation of essential developmental hormones. Given the recent clinical focus on neurorepair for PBI, we hypothesized that there would be injury-induced changes in erythropoietin (EPO), erythropoietin receptor (EPOR), melatonin receptor (MLTR), NAD-dependent deacetylase sirtuin-1 (SIRT1) signaling, and hypoxia inducible factors (HIF1α, HIF2α). Specifically, we predicted that EPO, EPOR, MLTR1, SIRT1, HIF1α and HIF2α alterations after chorioamnionitis (CHORIO) would reflect relative changes observed in human preterm infants. Similarly, we expected unique developmental regulation after injury that would reveal potential clues to mechanisms and timing of inflammatory and oxidative injury after CHORIO that could inform future therapeutic development to treat PBI. Methods: To induce CHORIO, a laparotomy was performed on embryonic day 18 (E18) in rats with transient uterine artery occlusion plus intra-amniotic injection of lipopolysaccharide (LPS). Placentae and fetal brains were collected at 24 h. Brains were also collected on postnatal day 2 (P2), P7, and P21. EPO, EPOR, MLTR1, SIRT1, HIF1α and HIF2α levels were quantified using a clinical electrochemiluminescent biomarker platform, qPCR, and/or RNAscope. MLT levels were quantified with liquid chromatography mass spectrometry. Results: Examination of EPO, EPOR, and MLTR1 at 24 h showed that while placental levels of EPO and MLTR1 mRNA were decreased acutely after CHORIO, cerebral levels of EPO, EPOR and MLTR1 mRNA were increased compared to control. Notably, CHORIO brains at P2 were SIRT1 mRNA deficient with increased HIF1α and HIF2α despite normalized levels of EPO, EPOR and MLTR1, and in the presence of elevated serum EPO levels. Uniquely, brain levels of EPO, EPOR and MLTR1 shifted at P7 and P21, with prominent CHORIO-induced changes in mRNA expression. Reductions at P21 were concomitant with increased serum EPO levels in CHORIO rats compared to controls and variable MLT levels. Discussion: These data reveal that commensurate with robust inflammation through the maternal placental-fetal axis, CHORIO impacts EPO, MLT, SIRT1, and HIF signal transduction defined by dynamic changes in EPO, EPOR, MLTR1, SIRT1, HIF1α and HIF2α mRNA, and EPO protein. Notably, ligand-receptor mismatch, tissue compartment differential regulation, and non-receptor-mediated signaling highlight the importance, complexity and nuance of neural and immune cell development and provide essential clues to mechanisms of injury in PBI. As the placenta, immune cells, and neural cells share many common, developmentally regulated signal transduction pathways, further studies are needed to clarify the perinatal dynamics of EPO and MLT signaling and to capitalize on therapies that target endogenous neurorepair mechanisms.

Sexual dimorphism in inorganic mercury toxicokinetics and the attendant lipotoxic and non-lipotoxic dyslipidemia in the rat.

The influence of variability in the biology of living organisms is poorly appreciated in toxicology. However, multiple lines of evidence indicate that sex-differences modulate toxicokinetics and toxicodynamics from cellular/molecular to whole animal levels resulting in different toxic responses of living organisms to xenobiotics exposure. In order to investigate the influence of sex in inorganic mercury (Hg) exposure, male and female Wistar rats were exposed to 0.5, 1.0 and 1.5 mg Hg/kg body weight orally as HgCl2 twice a week for 12 weeks. Higher Hg levels in the females (except heart) as compared to males were observed in the animals. At the highest dose of inorganic Hg, female renal Hg content was 3.3 times higher than that of the males. Mixed sexual dimorphism characterised circulating-lipid- and organ-lipid lipotoxic and non-lipotoxic dyslipidemia. The highest dose of inorganic Hg, induced hypercholesterolemia in the males as opposed to hypocholesterolemia in the female. Plasma and erythrocyte free fatty acids increased in both sexes, although the increase was more pronounced in the male. Reverse cholesterol transport was inhibited in the male at the highest dose of Hg, whereas female HDL became enriched with cholesterol. Female erythrocytes had all their lipids increased, whereas only male erythrocyte triglyceride increased. Brain cholesterol and phospholipids, and splenic phospholipids were depleted in both sexes. Our findings indicate that inorganic Hg exposure appears to affect Hg and lipid kinetics differently in both sexes, thus underscoring the need to develop sex-tailored approaches in the treatment of metal toxicosis and its metabolic outcomes.

Application of the research electronic data capture (REDCap) system in a low- and middle income country- experiences, lessons, and challenges.

The challenges of reliably collecting, storing, organizing, and analyzing research data are critical in low- and middle-income countries (LMICs), particularly in Sub-Saharan Africa where several healthcare and biomedical research organizations have limited data infrastructure. The Research Electronic Data Capture (REDCap) System has been widely used by many institutions and hospitals in the USA for data collection, entry, and management and could help solve this problem. This study reports on the experiences, challenges, and lessons learned from establishing and applying REDCap for a large US-Nigeria research partnership that includes two sites in Nigeria, (the College of Medicine of the University of Lagos (CMUL) and Jos University Teaching Hospital (JUTH)) and Northwestern University (NU) in Chicago, Illinois in the United States. The largest challenges to this implementation were significant technical obstacles: the lack of REDCap-trained personnel, transient electrical power supply, and slow/intermittent internet connectivity. However, asynchronous communication and on-site hands-on collaboration between the Nigerian sites and NU led to the successful installation and configuration of REDCap to meet the needs of the Nigerian sites. An example of one lesson learned is the use of Virtual Private Network (VPN) as a solution to poor internet connectivity at one of the sites, and its adoption is underway at the other. Virtual Private Servers (VPS) or shared online hosting were also evaluated and offer alternative solutions. Installing and using REDCap in LMIC institutions for research data management is feasible; however, planning for trained personnel and addressing electrical and internet infrastructural requirements are essential to optimize its use. Building this fundamental research capacity within LMICs across Africa could substantially enhance the potential for more cross-institutional and cross-country collaboration in future research endeavors.

Parental monitoring and substance use among youths: A survey of high school adolescents in Lagos State, Nigeria.

BACKGROUND: Risk behaviours including marijuana use, alcohol consumption and cigarette smoking have a significant impact on the present and future health of adolescents. There are limited studies in sub-Saharan Africa to show evidence, if it exists, of the relationship between parental monitoring practices and the prevalence of substance use among adolescents. The aim of this study is to assess the relationship between parental monitoring practices and alcohol consumption, cigarette smoking and marijuana use among in-school adolescents in Mushin Local Government Area of Lagos State, South-Western Nigeria. METHODS: This was a cross-sectional survey of 437 in-school adolescents randomly selected from two schools in Mushin Local Government Area of Lagos State, Nigeria. Information on socio-demographic characteristics, the three domains of parental monitoring practices (Parental monitoring; negotiated unsupervised time and parental trust) and substance use were elicited using a modified version of parental monitoring practice scale and the Youth Risk Behaviour Surveillance System (YRBSS) questionnaire. Independent T tests and logistic regression models were used to assess relationship between parental monitoring practices and substance use. RESULTS: The overall prevalence of use of any of the substance was 21.7%. Negotiated unsupervised time was significantly associated with use of alcohol (P < 0.05), marijuana (P < 0.05) and cigarette smoking (P < 0.05). After controlling for age and gender, one unit increase in parental monitoring reduced the odds of engaging in any substance use by 10% (AOR = 0.90, 95% CI = 0.81-0.99) while a similar increase in negotiated unsupervised time significantly increases the odds of any substance use by 7% (AOR = 1.07, 95% CI = 1.01-1.14). CONCLUSION: Of the three domains assessed, negotiated unsupervised time was consistently associated with substance use among these youth. Efforts to educate parents on the need to restrict unsupervised time of their wards may be warranted.

Higher order multiple births in Nigeria: Experiences, challenges and neonatal outcomes in a private health facility.

OBJECTIVES: The aim of this study is to describe the experience and outcome of higher order multiple (HOM) births in a private tertiary health facility in Nigeria. MATERIALS AND METHODS: This was a retrospective review of records of HOM over 3 years in a private tertiary health facility in Nigeria. Relevant data on HOM births were extracted from both the patients' case notes, admission registers and maternity ward and delivery records of the hospital using a predesigned pro forma. Data were analyzed using Statistical Package for Social Sciences Version 22.0. RESULTS: The prevalence of HOM births was 0.72% of 1950 births over the 3 years study period; while for triplets, quadruplets, and quintuplets were 0.56%, 0.1% and 0.05%, respectively. The mean gestational age was 32 ± 3 weeks, and all except three sets of triplets were by Assisted Reproductive Technology (ART). Respiratory distress syndrome, neonatal jaundice, and neonatal sepsis accounted for more than 80% of the neonatal complications noted in HOM births. However, there was no significant difference between neonatal survival of HOM as compared to twin deliveries, P = 0.08. CONCLUSION: HOM is becoming increasingly common in Nigeria. The strongest risk factor is ART, and neonatal complications are common reinforcing the need to streamline ART protocols in Nigeria.

Heavy metal burdens of public primary school children related to playground soils and classroom dusts in Ibadan North-West local government area, Nigeria.

Information about heavy metal burden of children in Nigeria related to playground soils and classroom dusts is lacking. Playground soil, classroom dust, blood and spot urine samples (n=253) were collected from 6 urban and 2 semi-rural public schools in Ibadan North-West, Nigeria. Samples were analysed for Pb, Cu, Zn, Fe and Mn. Mean blood Pb levels in urban area (male, 41.66±8.78µg/dl vs. female, 40.64±5.46µg/dl) were twice as high as those in semi-rural area (male, 19.71±3.73µg/dl vs. female, 20.65±2.26µg/dl). Concentrations of Pb, Cu, Zn, and Fe in soil and dust samples in the urban schools were between 2- to 4-fold greater than that of semi-rural schools. No correlation was observed between blood and dust metals. A positive correlation (r=0.168, p=0.008) was observed between blood Pb and playground soil Pb. Pb burden in the children might be from their schools' playgrounds and other yet unidentified sources.

Risk Perception and Correlates of Tobacco Use among Young People Outside of Formal School Settings in Lagos State, Nigeria.

BACKGROUND: Tobacco use among youth is a major public health problem. Youth outside of formal school settings are often understudied but may be at increased risk. MATERIALS AND METHODS: A descriptive cross- sectional study was carried out among 326 young people aged 15-24 years in four randomly selected motor parks in Lagos state. Interviewer-administered questionnaires were used to collect data. RESULTS: The mean age of the respondents was 21.0±2.3yrs. Many 252 (77.3%) dropped out before the end of the third year of secondary schooling. The majority were aware that active (78.2%), and passive smoking (77.3%) are harmful to health. Nearly two-thirds of the respondents disagreed with an outright ban of cigarettes (63.2%) and restriction of cigarette sales to persons below 18 years (67.9%) while 254 (66.8%) supported a ban on tobacco smoking in enclosed public places. One hundred and fifty (46.0%) respondents had experimented with smoking of which 106 (32.5%) had progressed to become current smokers. Half of the current smokers, 54 (50.9%), felt the need for a cigarette first thing in the morning. A multivariate analysis for smoking initiation, showed that for every increasing year of age, respondents were 1.08 times more likely to have initiated cigarette smoking; males and respondents who lived alone or with peers were 2.34 times and 1.77 times more likely to have initiated smoking respectively; those who consume alcohol and marijuana were 7.27 and 1.89 times respectively more likely to have initiated smoking while those who consumed alcohol were 6.17 times more likely to be current smokers.

Risk perception and correlates of alcohol use among out-of-school youth in motor parks in Lagos State, Nigeria.

BACKGROUND AND AIM: The prevalence of alcohol use has increased globally. Out-of-school youth are a vulnerable group who might have missed opportunities for learning healthy behaviours in a formal school environment. The purpose of this study was to determine the risk perception, pattern of use, and correlates of alcohol use among out-of-school youth in Lagos, Nigeria. METHODS: A cross-sectional study was conducted among 380 out-of-school youth in motor parks in Lagos State, Nigeria, using interviewer administered questionnaires. RESULTS: The lifetime prevalence of alcohol use was 61.1%, while 55.5% were current drinkers. Beer (57.3%) was the most consumed type of alcohol, followed by distilled spirits (29.8%). Using the CAGE scoring system, more than half (57.8%) of the current drinkers had a drinking problem. Almost three quarters (70.1%) had experienced at least one episode of alcohol intoxication within the past month. A considerable number of current drinkers (63.5%) desired to reduce their alcohol intake or stop drinking, while 45.5% had made unsuccessful attempts to do so within the past year. Only 28.9% had received assistance to quit or reduce their drinking and of these less than half (39.3%) received assistance from a professional or healthcare worker. Males were more likely to be current drinkers and to have experienced episodes of alcohol intoxication. Parental and peer drinking were associated with alcohol use but not with intoxication. CONCLUSIONS: It is important to design specific programmes to reduce alcohol use among out-of-school youth in these settings.

The effect of a short anti-smoking awareness programme on the knowledge, attitude and practice of cigarette smoking among secondary school students in Lagos state, Nigeria.

UNLABELLED: This study aimed to assess the effect of a short school-based anti-smoking program on the knowledge, attitude and practice of cigarette smoking among students in secondary schools in Lagos State. SUBJECTS AND METHODS: A non-randomized, controlled intervention study was done among respondents selected using multi-stage sampling. Baseline data was collected using self-administered questionnaires. An anti-smoking awareness programme was carried out among students in the intervention group using health talks, information leaflets and posters. Post-intervention data collection took place three months later. RESULTS: There were significant increments in the mean knowledge and attitude scores after the intervention. There was however no statistically significant change in the current smoking habits of respondents (4% vs. 3%; p=0.41)in the intervention group. Nevertheless, in the intervention group, the number of never- smokers who reported that they were likely to initiate cigarette smoking within the next year significantly reduced. There was also a significant increase in the proportion of current smokers who desired to quit smoking. CONCLUSION: Even brief anti-smoking programs of this nature are effective at improving the knowledge and modifying the attitude of the respondents but do not improve smoking habits. It however motivated the desire to quit among current smokers. Health education sessions and periodic anti-smoking programmes should be introduced into the secondary school curriculum. More intensive approaches may be needed to influence the smoking behaviour of adolescent smokers.

Evaluation of a health resources management course for Nigerian doctors.

AIMS AND OBJECTIVES: This study aimed to evaluate the March 2010 edition of the regular biannual two-week course on health resources management organised by the National Postgraduate Medical College of Nigeria. The main objectives were to assess participants' perception of the course and to measure change in their knowledge brought about by the course. SUBJECTS AND METHODS: This is a primarily cross-sectional study but with a before and after component. The study population comprised all participants who attended the course. Data were collected using pre-tested structured self- administered questionnaires. Data analysis was done with Epi Info 3.5.1. Student's T-test was used to compare mean scores at pre-test and post-test and the p-value of <0.05 was considered statistically significant. RESULTS: Majority (95.8%) of the participants were senior registrars from teaching hospitals and most of them (70.5%) claimed the course met their needs a great deal/to a large extent. The participants were satisfied to a varying degree with different aspects of the course but overall 50.9% claimed they got value for their money. There was a statistically significant difference in the knowledge score at pre- and post-test (t = 3.19, p = 0.002). CONCLUSION: The course met the needs of the participants largely and was able to improve their knowledge of health resources management as intended. A behaviour evaluation is recommended in order to assess the usefulness of the course to participants' practice.

Blood donation practices and willingness to donate among residents of an urban slum in Lagos Nigeria.

AIM AND OBJECTIVES: This study was carried out to assess the blood donation practices and willingness to donate among residents of an urban slum. MATERIAL AND METHODS: Cross sectional descriptive study design with a qualitative and quantitative component. Multistage sampling was used to select 400 respondents for the questionnaire interview while three FGD sessions were conducted guide among three groups of participants namely youths, men and women. The information collected was analyzed manually (FGD) and with Epi info version 3.5.3. RESULTS: Majority of the questionnaire respondents were female, married, traders, had at least secondary school education, with mean age of 37.6 years. Only 12.0% had donated in the past, the main reason given by non donors was that they had never been asked to donate; this was also a key finding in the FGD. Willingness to donate was positively associated with being a male, single and Christian, age was a significant predictor of previous donation while more of the previous donors were still willing to donate, more for family/friends (p=0.036) than voluntarily (p=0.001) this view was supported by the participants at the FGD. CONCLUSION: Members of this urban slum had poor practice of blood donation,had positive attitude and were willing to donate, there is need to mobilise and organise outreach blood donation programs to convert attitude into actual practice.

Analysis of Elastic Tissue in Histological Variants of Pleomorphic Salivary Adenoma seen at the Lagos University Teaching Hospital over a period of 35 Years.

BACKGROUND: Pleomorphic salivary adenoma (PSA), is known for its morphologic diversity. While reports of elastic tissue in PSA have been documented, the distribution of this tissue in histological variants of the tumour has not been documented. Perhaps such features may influence biological behaviour of these variants. OBJECTIVE: To classify PSA in our series into histological variants, and determine possible variation in elastic tissue distribution in them. METHODS: Eighty eight histologically diagnosed cases of PSA in the oral biopsy archives of the department of Oral Biology and Pathology, Lagos University Teaching Hospital, were retrieved. New H&E sections were cut to reconfirm diagnosis and Verhoeff-Van Gieson's stained sections were cut for demonstration of elastic tissue. Seifert et al.'s (1976) histological classification was applied and elastic tissue presence was determined and quantified for each case. Parameters studied included; sex, age, site, histological subtypes and presence of elastic tissue. Statistical analysis was undertaken using the EPI-INFO version 3.4. RESULTS: Male:female ratio was 1:1.3. Most cases (63.6%) occurred in the age group of 21-40 years. Generally, palate (42.0%) was the most commonly affected site, while 53.4% of cases were in the minor salivary glands. Seifert et al. classified subtype II lesions were the most frequently observed (39.7%) and elastic tissue was confirmed in 91.0% of cases. No association was noted between proportion of elastic tissue and histological variants. CONCLUSION: Seifert et al subtype II was the most frequently observed and no association was observed between proportion of elastic tissue and the histological variant of PSA.

Alcohol consumption and cigarette smoking pattern among brothel-based female sex workers in two local government areas in Lagos state, Nigeria.

BACKGROUND: Alcohol and tobacco use are known risk factors for non communicable diseases especially among women. Brothel based female sex workers may be at increased risk of exposure to these two substances. OBJECTIVE: To assess the pattern of alcohol and tobacco use among female sex workers in two selected local government areas in Lagos state, Nigeria. METHODS: A cross-sectional descriptive study was carried out among 323 brothel-based female sex workers in 39 consenting brothels. Data was collected by trained interviewers using a pretested structured questionnaire. RESULTS: Majority (67.8%) were current drinkers with 89.5% of these having their most recent drink less than a week ago. Most of them (89%) consumed more than the reference limits for alcohol use among women. Up to 20.7% were current smokers with (92.5%) having their most recent cigarette less than a week ago. More than a third (37.4%) were heavy smokers while 19% were dual users. Current drinking was associated with current smoking. Smokers consumed significantly more units of alcohol than non-smokers. CONCLUSION: The prevalence of harmful alcohol use and cigarette smoking are very high among this group of female sex workers. Programs that address the use of these substances should be made available for these women.

Pain and discomfort associated with orthodontic separator placement in patients attending the Lagos University Teaching Hospital, Lagos, Nigeria.

OBJECTIVE: To determine the perception of pain and discomfort associated with orthodontic separator placement in patients attending the Lagos University Teaching Hospital, Lagos, Nigeria. METHOD: Sixty four patients scheduled for treatment with fixed orthodontic appliances completed questionnaires before insertion of separators and after placement at 4 hours, 24 hours and 7 days. The level of pain and discomfort during these time periods was assessed by a visual analogue scale. RESULTS: There was a significant increase in the level of pain/discomfort 4 hours and 24 hours after placement of the separators for all the activities. The level of pain/discomfort peaked at 4 hours but did not return to baseline levels after 7 days. Patients more than 16 years old reported significantly more pain/discomfort over time than those 16 years and under. No significant difference in pain/discomfort was found between the sexes. CONCLUSION: Patients experience pain/discomfort following placement of orthodontic separators. Pretreatment counselling and analgesics are recommended.

Cervical cancer awareness and preventive practices: a challenge for female urban slum dwellers in Lagos, Nigeria.

Cervical cancer is the commonest gynaecological cancer in Nigeria and women of low socio-economic status are at high risk of this condition. A study was conducted on the awareness of cervical cancer, attitude towards the disease and screening practice of women residing in two urban slums of Lagos, Nigeria. It also determined the prevalence of major risk factors for cervical cancer among the women. Multistage sampling was used to select 240 women who were interviewed with a structured questionnaire and data collected was analyzed with Epi-info version 3.5.1 statistical software. Only 10 (4.2%) women in this study were aware of cervical cancer and none of them believed they were at risk of developing the disease. Most (73.3%) were willing to undergo a cervical cancer screening test. Age, education and previous history of vaginal examination were positively associated with willingness to undergo screening (p < 0.05). The respondents had a high prevalence of major risk factors for cervical cancer such as early age at sexual debut, multiple sexual partners and male partner with other female partners. Efforts need to be intensified to increase awareness of this condition and to promote low-cost cervical cancer screening among this underserved population.

Periapical granuloma associated with extracted teeth.

OBJECTIVE: This article aims to determine the incidence of periapical granuloma from extracted teeth and correlate the clinical diagnoses with the histopathological types of periapical granuloma. PATIENTS AND METHODS: Over a period of eight months, a prospective study designed as a routine biopsy of recoverable periapical tissues obtained from patients who had single tooth extraction was carried out. RESULTS: One hundred and thirty-six patients participated in the study, with 75 (55.1%) histopathologically diagnosed periradicular lesions. There were 23 (16.9%) cases of periapical granuloma, with a male to female ratio of 2: 1. The lesion presented mostly between the third and fourth decades of life (n=9, 6.6%). Clinically diagnosed acute apical periodontitis was significantly associated with periapical granuloma, with predominantly foamy macrophages and lymphocytes (P<0.05). CONCLUSION: Periapical granuloma appears to be a less common periapical lesion in this study compared to the previous reports. In contrast to reports that relate to an acute flare of the lesion with abundant neutrophilic infiltration, this study has shown marked foamy macrophages and lymphocytes at the acute phase, which are significantly associated with the clinical diagnosis of acute apical periodontitis. We recommend the classification of periapical granuloma into early, intermediate, and late stages of the lesion, based on the associated inflammatory cells.

Clinicopathological characteristics of odontogenic myxoma in Nigerians.

BACKGROUND: Odontogenic myxoma (OM) is a locally aggressive neoplasm whose clinicopathological characteristics have not been extensively reported in Nigerians. OBJECTIVE: To describe the clinicopathological characteristics of cases of OM seen at the Lagos University Teaching Hospital in Nigeria. METHODS: A review of both clinical and histopathological records of sixty-three cases of OM diagnosed over a period of thirty-seven years was undertaken. The cases were analyzed for age, sex, site, size, duration and histological contents of collagenization, odontogenic epithelium and calcification. RESULTS: Odontogenic myxoma represented 63(11.2%) cases of odontogenic tumours, was commonest in the second to forth decades and rare below age 10 and above 70 years. It was more common in females. Maxillary lesions were more common with respect to both central and peripheral histologic types, but occurred in equal frequencies in mandible and maxilla with respect to the central histologic type. Forty-seven (74.6%) cases were fibromyxoma and sixteen (25.4%) myxoma. Odontogenic epithelium was rare and observed in 5 (9.5%) cases while calcific material was present in sixteen (25.4%) cases. Late presentation was a common feature and surgical excision was the treatment of choice. CONCLUSION: Odontogenic myxoma is un-common among Nigerians when compared with ameloblastoma. Clinicopathological characteristics in this series are similar to information in the scientific literature.

Melanin pigmented periradicular lesions of extracted teeth: a report of 3 cases and review of the literature.

This article reports 3 cases of melanin pigmented lesions among 75 histologically diagnosed periradicular lesions of extracted teeth. Case 1 was a 25-year old male who presented with one week history of toothache involving a tender carious left mandibular second molar tooth (37), with periapical radiolucency and diagnosed clinically as acute apical periodontitis. The lesion was diagnosed histologically (using Haematoxylin and Eosin) as periapical granuloma, while histochemical examination (using Masson-Fontana technique) showed the presence of round/oval shaped melanin pigmented macrophages (melanophage) in the lesion. Case 2 was a 54-year old male with one week history of toothache associated with tender carious right maxillary first molar tooth (16) with periapical radiolucency. A clinical diagnosis of acute apical periodontitis was made, but histological and histochemical examination showed a melanin pigmented periapical granuloma with spindle shaped melanophage. Case 3 was a 28-year old female who presented with 4 days history of toothache, involving the tender left mandibular first molar tooth (36). The lesion had periapical radiolucency and a clinical diagnosis of acute apical periodontitis. On examination histologically and histochemically, the lesion was diagnosed as an intraosseous melanocytic naevi with dark-brown nests of round naevus cells. In conclusion, this article shows the rarity of melanin pigmented periradicular lesions in the jaws. The cases reported suggest that the trigger for formation of melanin-pigmented cells in the periradicular lesions may be related to the acute phase of the lesions. Further study is recommended to determine if the remnants of the migratory neural crest cells are the precursors of melanin-pigmented cells in the periradicular region.

Clinicopathological study of 100 Nigerian cases of ameloblastoma.

SUMMARY: Clinicopathological analysis and growth rate study of 100 cases of ameloblastoma was undertaken. The tumour had site predilection for the mandible (91.0%) and occurred more in males than in females (ratio 1:0.9). 62.0% of patients in the series were less than 20 years of age. The estimated monthly growth rate (EMGR) of ameloblastoma was observed to be slower in males although the mean tumour volume recorded in females was lower than males in the series. The biologic aggression of 4 various types of ameloblastoma was predicted using EMGR and average volume of tumour at hospital presentation as predictive markers. Solid multicystic ameloblastoma was observed with the fastest EMGR of 0.81 cm(3)/month. Peripheral ameloblastoma was observed with the slowest EMGR of 0.17 cm(3)/ month. It was concluded that all the 4 types of ameloblastoma observed were clinically distinct and showed varying biologic aggression. The solid multicystic type with the highest growth rate (0.81 cm(3)/month) was considered the most aggressive while the peripheral type (growth rate = 0.17 cm(3)/month) was the least aggressive. It is therefore necessary to distinguish between the various clinical types of ameloblastoma before a clinician proceeds with definitive treatment.

Reversal of ionoregulatory disruptions in occupational lead exposure by vitamin C.

In order to investigate the toxic effects of lead during occupational exposure to this metal and the antidotal efficacy of ascorbic acid directed against these toxic effects, various artisans in Abeokuta, Nigeria, who have been shown to be occupationally exposed to lead were supplemented daily with 500mg ascorbic acid for 2 weeks. Ca(2+)-Mg(2+)-ATPase activity in erythrocyte membrane, as well as calcium and magnesium concentrations in plasma, erythrocytes, erythrocyte membrane and urine of the artisans were determined before and after ascorbic acid supplementation. The 2-week ascorbic acid administration resulted in the reversal of lead-induced accumulation of calcium and magnesium in the erythrocyte membranes of the artisans. Ascorbic acid also reversed lead-induced inhibition of erythrocyte membrane Ca(2+)-Mg(2+)-ATPase. Urinary excretion of calcium and magnesium was not affected by ascorbic acid. There may be some scope in introducing ascorbic acid as an intervention strategy for the prevention and therapy of lead intoxication, especially in cases where the subjects cannot be removed from the source of lead exposure.