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.

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.

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.

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.

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.

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.

Water quality assessment of Ogun river, South West Nigeria.

The quality of Ogun river in South-West, Nigeria was studied by a field survey for a period of 1 year (covering dry season and rainy season). Water samples were collected from thirteen sites and analysed for physico-chemical and bacteriological parameters as well as heavy metals using standard methods. Generally, the values obtained for turbidity, phosphate, oil and grease, iron and faecal coliform from all the sites in both seasons were above the maximum acceptable limit set by the World Health Organization (WHO) for drinking water. Also, the manganese content from all the sites in the dry season, lead concentrations from three sites in the dry season and cadmium concentrations from some sites in both seasons were above the WHO limit. The values obtained for total dissolved solids, dissolved oxygen and chloride at site M in the dry season and nitrate at site J in the rainy season were also above the WHO limit. Pollution of Ogun river water along its course is evidenced by the high concentrations of pollution indicators, nutrients and trace metals above the acceptable limit. This poses a health risk to several rural communities who rely on the river primarily as their source of domestic water. The study showed a need for continuous pollution monitoring programme of surface waters in Nigeria.

Biomarkers of lead exposure in petrol station attendants and auto-mechanics in Abeokuta, Nigeria: effect of 2-week ascorbic acid supplementation.

In order to study the ameliorative effects of ascorbic acid in chronic lead poisoning, petrol station attendants and auto-mechanics in Abeokuta, Nigeria, who have been shown to be occupationally exposed to lead and university students (serving as control), were supplemented daily with 500mg ascorbic acid for 2 weeks. Blood and urine samples were collected from the subjects before and after ascorbic acid regimen and analysed for lead and biochemical effects associated with lead toxicity. The 2-week ascorbic acid supplementation resulted in a significant (P < 0.05) reduction in blood lead in the occupationally exposed subjects. The reduction in blood lead amounted to 57% in male petrol station attendants, 50% in female petrol station attendants and 44% in the auto-mechanics. Urinary excretion of lead increased remarkably in the occupationally exposed subjects (P < 0.05). The biochemical effects associated with the toxic effects of lead also responded positively to the ascorbic acid regimen. Plasma and urine aminolevulinic acid (ALA) were reduced significantly (P < 0.05) by as much as 55% and 57% respectively. Plasma calcium also increased significantly (P < 0.05) in the subjects. Decreased levels of reduced glutathione (GSH) and hemoglobin observed in the occupationally exposed subjects were reversed by ascorbic acid. Glutathione-S-transferase (GST) and catalase (CAT) activities were not affected. Our findings indicate that ascorbic acid may be useful as an economical and convenient prophylactic agent for lead poisoning.

Anaplastic carcinoma of the parotid gland: a case report of a patient disease free after nine years. Follow-up.

A case of massive anaplastic carcinoma of the left parotid gland in a 29-year old female Nigerian, of Yoruba tribe, for which radical left parotidectomy with external carotid artery ligation and post-operative radiotherapy was performed is presented Nine years post-operatively, no evidence of recurrence or metastasis was found. The patient is in apparent good health, despite the amount of tumour spillage that was experienced intra-operatively. As far as we have been able to check, it is to our knowledge the first of such from Nigeria.

Pb, Zn, and Cu levels in tree barks as indicator of atmospheric pollution.

Barks of seven species of trees were sampled at 32 locations having different pollution levels in Abeokuta, Nigeria. The concentrations of Pb, Zn, and Cu were determined by atomic absorption spectrometry. The Pb and Zn contents, 1.9-159.8 and 16.5-659.1 micrograms g-1, dry weight respectively, correlate with traffic volume, indicating pollution from anthropogenic sources. The results obtained for Cu, 4.2-20.7 micrograms g-1, dry weight, though lower, were still significant but did not show any correlation with traffic density. The study also confirms the suitability of Azadirachta indica (Dogoyaro--a very popular local tree) as a suitable bio-indicator of aerial fallout of heavy metals.

Acute poisoning in the emergency room in Lagos University Teaching Hospital.

This paper reviews 146 cases of acute poisoning seen and treated by us at the adult accident and emergency centre of Lagos University Teaching Hospital, Nigeria, between 1979 and 1982. Barbiturates (19%) and benzodiazepines (17%) were the commonest drugs used in acute poisoning. The highest incidence (41%) was found among persons aged 18-25 years. There were 67 males and 79 females (1:1.2). About 14% took a "cocktail" of more than one drug. Self-poisoning occurred in 74%; 8.6% were apparently suicidal; 15.8% were accidental; and 1.4% were homicidal. Fifty of the patients (33%) were unconscious on admission. The centre's management technique is briefly discussed and the need for a poisons information centre in the country is highlighted.