Levels of Clara cell secretory protein and surfactant protein A in municipal solid waste management workers in Ibadan, Southwest Nigeria.

Toxic pneumonitis and related respiratory symptoms are common among waste management workers (WMWs). Products of different cellular responses following exposure to toxic components of wastes can lead to the production of a variety of biomolecules. There is a growing recognition of the importance of biomarkers in risk assessment and a strong advocacy for their determination and use as indicators of health and safety. This study assessed the prevalence of respiratory symptoms and the relevance of pulmonary surfactant protein A (SP-A) and Clara cell 16 protein (CC16) as indicators of occupational inhalation exposure to toxic substances and irritants in WMW. A total of 172 subjects consisting of 112 WMWs and 60 Non-WMWs were recruited by purposive sampling. Data on socio-economic and work-related symptoms were collected using structured questionnaire. CC16 and SP-A were determined by ELISA in serum samples. Clinical history reveals a slightly higher prevalence of respiratory symptoms in WMWs relative to control subjects. Increased permeability of the lung-blood barrier, characterized by significant elevation of serum SP-A and serum CC16, was associated with respiratory symptoms in WMWs. Steady increases in SP-A and CC16, respectively, in relation to occupational duration were observed in WMWs relative to control. Receiver operating characteristic curve and multivariate analyses revealed SP-A and CC16 as important lung biomarkers for assessing sub-clinical effects of occupational exposure. Our data suggest SP-A and CC16 may be relevant indicators for assessing occupational inhalation exposure to toxic substances and irritants among WMWs.

Patterns and Correlates of Serum Magnesium Levels in Subsets of Type 2 Diabetes Mellitus Patients in Nigeria.

BACKGROUND: Magnesium (Mg) is the 4th most common mineral and the 2nd most abundant intracellular cation in the body. It plays major roles in various physiological activities and has been implicated in many disease states. AIM: The aim of this study was to study the patterns and correlates of serum Mg in cohorts of type 2 diabetic patients in Nigeria. SUBJECTS AND METHODS: One hundred and twenty-five patients comprising 63 with type 2 diabetes mellitus (T2DM) alone and 62 with diabetes and hypertension (HT) were compared with fifty controls matched for sex and age. Basic data, HbA1c, and fasting blood glucose (FBG) were obtained while serum Mg was measured by colorimeter. Relationship between serum Mg and glucose control was considered while serum Mg < 1.6 mg/dl was considered as hypomagnesemia. RESULTS: The mean serum Mg of all patients was 2.06 ± 0.49 mg/dl, not statistically different from controls at 2.22 ± 0.48 mg/dl. About » (23.2%) of the patients had hypomagnesemia which was significantly more than 12% of controls. Although the patients with diabetes and HT were older and more of females than those with DM alone, the mean serum Mg was comparable (2.03 ± 0.49 vs. 2.09 + 0.50 mg/dl). Twenty-seven percent (27%) of patients who had DM alone was more than 19.3% with HT and diabetes combined. Whereas the FBG was comparable in patients with hypomagnesemia and normal serum Mg, HbA1c was significantly higher in the hypomagnesemia group (8.39 ± 0.98 vs. 6.75 ± 1.22%, P = 0.021). CONCLUSION: Hypomagnesemia is common in T2DM outpatients occurring approximately one in four patients. It is associated with poor long-term control.

Levels of heavy and essential trace metals and their correlation with antioxidant and health status in individuals occupationally exposed to municipal solid wastes.

Recent studies have indicated an increased incidence of toxic neuropathies among waste management workers (WMW) possibly linked to increased detection of heavy metals in municipal solid wastes. The present study evaluated serum levels of some heavy and essential trace metals in relation to oxidant/antioxidant status of WMW. One hundred and twenty-six WMW and 84 non-WMW (control) were recruited. Metal/element concentration was measured by atomic absorption spectrophotometry and oxidant/antioxidant markers were determined using standard procedures. The WMW exhibited significantly ( p < 0.001) decreased ferric reducing ability of plasma (FRAP) and higher levels of ceruloplasmin (Cp) and malondialdehyde. Iron (Fe) and copper (Cu) levels were significantly lower ( p < 0.05) and higher ( p < 0.001), respectively in WMW when compared with control while levels of other trace elements were not significantly different between these groups. Lead (Pb) and chromium levels were significantly higher ( p < 0.001 and p < 0.05, respectively) in WMW while mercury levels were comparable with those of control subjects. In WMW, Cp ( r = -0.182; p > 0.05) and FRAP ( r = 0.277; p < 0.05) negatively and positively correlated with Pb, respectively, while a positive correlation was observed between zinc ( r = 0.230; p < 0.05) and Pb and between Cu ( r = 0.541; p > 0.001) and Fe. Overall, the decreased antioxidant capacity and increased oxidative stress observed in WMW in this study may be related to their blood levels of heavy and essential trace metals. Conscious efforts are required, therefore, to reduce risk and protect WMW from toxic neuropathies and other adverse health consequences of occupational exposure.

Occupational exposure to municipal solid wastes and development of toxic neuropathies: possible role of nutrient supplementation, complementary and alternative medicines in chemoprevention.

Achieving effective municipal solid waste (MSW) management remains a major challenge and waste generation and accumulation continue to constitute important environmental and public health concern, particularly in most developing countries. Although the general population is at risk of adverse health consequences and hazards associated with exposure to MSW, the waste management workers (WMWs) are the most vulnerable because of their direct involvement in the disposal of waste, with increasing evidence of work-related health and safety risks among these individuals. Among the numerous work-related health hazards prevalent in WMWs, development of toxic neuropathies following chronic occupational exposure remains poorly recognized. However, the risk or predisposition to toxic neuropathies is becoming evident considering the increasing recognition of large amount of neurotoxic heavy metals and hazardous industrial materials present in MSW in most parts of the world. The present review seeks to draw attention to the continuous vulnerability of the WMWs to developing toxic neuropathies. This is aimed at facilitating conscious efforts by relevant governmental and nongovernmental agencies towards promoting risk reduction and ensuring adequate protection against possible toxic polyneuropathies associated with occupational exposure to solid wastes. While continuous education of the WMWs on the need for adequate compliance to safety regulations and practice remains sacrosanct towards achieving significant reduction in toxic neuropathies and related adverse health consequences of waste handling, it is also our intention in this review to underscore the possible relevance of nutrient supplementation and alternative medicines in chemoprevention.

Possible role of plasma ceruloplasmin and erythrocyte sedimentation rate in assessing compliance with occupational hygiene and safety practices in waste management workers.

OBJECTIVES: Work-related health and safety risks are common among waste management workers (WMWs). This study investigated the level of compliance with safety measures in relation to levels of inflammatory markers among WMWs in Sagamu, South-West Nigeria. MATERIALS AND METHODS: WMWs comprising 30 cart pushers (CPs) and 50 truck users (TUs) were recruited alongside 45 people from the normal population as control. Data on health complaints were obtained from questionnaire surveys. Inflammation was assessed by measuring plasma ceruloplasmin (Cp), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and albumin. RESULTS: WMWs exhibited a significantly higher prevalence of respiratory and gastrointestinal symptoms and poor compliance with health and safety measures. Significant (P < 0.001) differences were observed in the use of masks, hand gloves, protective clothing, and footwear between TUs and CPs. ESR, Cp, and CRP increased significantly (P < 0.001) by 145, 28.7, and 42.5% in TUs and by 164, 50.5, and 74.3% in CPs, respectively, relative to control. Negative correlation was observed between use of mask (r = -0.225, P < 0.01), use of gloves (r = -0.184, P < 0.05), and Cp and between ESR and washing of hands with soap (r = -0.185, P < 0.05). The use of goggles (r = +0.285, P < 0.001), washing of hands with soap (r = +0.203; P < 0.01), use of masks (r = +0.317, P < 0.001), and use of gloves correlated positively in WMWs. CONCLUSIONS: A higher prevalence of work-related symptoms and elevated inflammatory markers in WMWs was related to poor compliance with safety measures. ESR and Cp may be useful predictors of occupational hygiene and compliance with safety measures among Nigerian WMWs.

Effect of exposure to solid wastes in relation to employment duration on some important markers of health and disease in waste management workers of Ogun State in southwest Nigeria.

Waste management workers (WMWs) around the world are at risk of work-related health disorders. The influence of employment duration on individuals occupationally exposed to solid waste was investigated in this study. The study comprised (n = 280) 180 WMWs and 100 controls. Employment duration was obtained from questionnaire survey and categorized into three groups: group I (0.5-2 years), group II (>2-4 years) and group III (>4-6 years). Blood sample (10 ml) was collected from the antecubital vein of subjects for analysis. WMWs exhibited significantly (p < 0.001) elevated inflammatory markers (erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and ceruloplasmin (Cp)) relative to control. While Cp increased, ESR and CRP decreased with increasing WMWs' employment duration. Alteration in oxidant/antioxidant markers was characterized by significant (p < 0.001) decrease in ferric-reducing ability of plasma (FRAP) and catalase activity together with marked (p < 0.01) elevation of thiobarbituric acid reactive substances (TBARS) and uric acid (UA). TBARS, UA and FRAP increased while catalase decreased with WMWs' employment duration. In addition, WMWs exhibited significantly (p < 0.01) elevated immunoglobulin A (IgA) and IgG, which also increased and decreased, respectively, with job duration. The significantly (p < 0.01) decreased haemoglobin and haematocrit levels as well as the significantly (p < 0.001) elevated total leukocytes in WMWs increased with employment duration. Alanine aminotransferase increased and albumin decreased significantly (p < 0.05) in WMWs, and these changes also increased and decreased, respectively, with job duration. Data suggest that levels of alteration of important systemic markers of health/disease are related to WMWs' employment or exposure duration.

Modulation of paracetamol-induced hepatotoxicity by phosphodiesterase isozyme inhibition in rats: a preliminary study.

BACKGROUND: Altered regulation of nitric oxide-cyclic guanosine monophosphate (NO-cGMP) is present in liver cirrhosis. Several experimental studies have shown that selective modulation of NO metabolism in the liver reduces intrahepatic resistance and portal pressure in cirrhosis. This preliminary study investigated whether selective inhibition of phosphodiesterase-5 (PDE-5), which prevents the conversion of cGMP to 5'-GMP, as well as non-selective inhibition of PDE isozymes could ameliorate hepatic toxicity induced by paracetamol (PCM). METHODS: PCM (250 mg/kg, i.p.) was administered to induce hepatotoxicity. Control rats received physiological saline (10 mL/kg, p.o.), while sildenafil (a selective PDE-5 inhibitor) and aminophylline (a non-selective PDE inhibitor) were administered separately at 10 mg/kg p.o. to PCM-treated rats. RESULTS: PCM hepatotoxicity, characterized by elevation of aspartate and alanine aminotransferases, hepatic degeneration, and centrilobular necrosis, was attenuated by both PDE inhibitors. Sildenafil and aminophylline significantly (p<0.05) reduced plasma aspartate aminotransferase activity by 49.6% and 39.8%, respectively, with moderate increase in alanine aminotransferase activity by 26.1% and 20.4%, respectively, in PCM-treated rats. Decreases in total protein and albumin induced by PCM were significantly (p<0.05) prevented by 30.0% and 22.2%, respectively, following sildenafil administration, while aminophylline decreased these proteins by 14.0% and 25.9%, respectively. Sildenafil and aminophylline significantly (p<0.05) reduced lipid peroxidation by 30.7% and 19.7%, respectively, while moderately increasing glutathione (GSH) in the PCM-treated rats. Both drugs did not significantly alter the total cholesterol and triglyceride levels. CONCLUSIONS: These preliminary data suggest that pharmacological inhibition of PDE isozymes may be a useful strategy in protecting against PCM hepatic toxicity.

The levels of inflammatory markers and oxidative stress in individuals occupationally exposed to municipal solid waste in Ogun State, South West Nigeria.

Airway inflammation and related respiratory complaints are common symptoms among waste management workers (WMWs). This study investigated the relationship between exposure to municipal solid waste (MSW) and the levels of inflammatory markers and oxidative stress among WMW of Ogun State, South West Nigeria. A total of 280 subjects consisting of 180 WMW and 100 controls were recruited. Ten millilitres of blood were collected from antecubital vein of the subjects for analysis. Results reveal that exposure to MSW is associated with systemic inflammation and oxidative stress. Significant (p < 0.001) elevation of ceruloplasmin (Cp) and C-reactive protein was associated with marked decreases in superoxide dismutase (p < 0.01), catalase (p < 0.001), and glutathione (p < 0.05) and significant (p < 0.001) increases in malondialdehyde (MDA) and uric acid when compared with control. Haematological disorders include significant (p < 0.05) decreases in haemoglobin, packed cell volume, and mean corpuscular volume and significant (p < 0.01) increase in total leucocyte count. Apart from decreased albumin (p < 0.05) and elevated aspartate aminotransferase (p < 0.05) activity observed in WMW, other markers of hepatic (alanine aminotransferase, alkaline phosphatase, total cholesterol and triglycerides) and renal (urea and creatinine) functions did not change significantly (p > 0.05) when compared with the control. A positive correlation between leucocytes (r = 0.195, p < 0.01), Cp (r = 0.210, p < 0.01) and job duration and between Cp and MDA (r = 0.200, p < 0.01) and Cp and leucocytes (r = 0.260, p < 0.001) were observed in WMW. Overall, exposure to MSW predisposes to systemic inflammation and oxidative stress and Cp may be a useful biomarker for monitoring health status of Nigerian WMWs.

Adenosine deaminase activity and immunoglobulin levels as potential systemic biomonitors of occupational hazards and health status in municipal solid waste management workers.

Immune status of waste management workers (WMW) with underlying systemic inflammation was assessed to identify useful immune-related biomarkers of occupational health and safety. Clinical history of WMW revealed high prevalence of respiratory symptoms alongside gastrointestinal and musculoskeletal complaints relative to control. Systemic inflammation, characterized by significant (p<0.001) elevation of erythrocyte sedimentation rate and C-reactive protein, was associated with marked increase in concentration and prevalence of IgA (p<0.05), IgG (p<0.01) and adenosine deaminase activity (ADA) (p<0.01) in WMW. Haematological changes include significant (p<0.01) increase in lymphocytes, monocytes and total leukocytes. Eosinophils also increased significantly (p<0.001) while haemoglobin, packed cell volume and neutrophil decreased significantly (p<0.05). Receiver operating characteristic curve and multivariate analyses revealed ADA (p<0.002) and IgG (p<0.05) as important immune markers respectively for assessing sub-clinical effects of occupational exposure. Our data suggest ADA and IgG as useful immune health and safety indicators in WMW.

Celecoxib, a selective cyclooxygenase-2 inhibitor, lowers plasma cholesterol and attenuates hepatic lipid peroxidation during carbon-tetrachloride-associated hepatotoxicity in rats.

Cyclooxygenase-2 (COX-2) expression and prostaglandin production are suggested to play important, complex roles in the pathogenesis of various liver diseases. Studies on the effects of COX-2 inhibitors on the progression of liver fibrosis present controversial results, and the proposed therapeutic potential of these agents in chronic liver disease is predicated largely on their effectiveness in modulating hepatic stellate cell activation in vitro. This study investigated the modulatory effect of celecoxib, a selective COX-2 inhibitor, in CCl(4)-mediated hepatotoxicity in rats. Thirty Wistar albino rats, weighing 120-180 g, were assigned into five groups of 6 rats/group. Groups 1 and 2 received saline (10 mL/kg) and CCl(4) (80 mg/kg), respectively. Group 3 was given celecoxib (5.7 mg/kg), whereas groups 4 and 5 were pretreated with 2.9 and 5.7 mg/kg/day of celecoxib, respectively, 1 hour before CCl(4) treatment. Plasma aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities increased significantly by 118.5, 150.0, and 51.3%, respectively, with an accompanying decrease (P < 0.05) in total protein and albumin after CCl(4) treatment. Hepatotoxicity was associated with a significant increase in plasma cholesterol, hepatic lipid peroxidation (LPO), and severe hepatic necrosis with marked fatty and cellular (i.e., mononuclear cells) infiltration. Although celecoxib neither reduced CCl(4)-induced increases in marker enzymes of hepatotoxicity nor significantly attenuated hepatic necrosis, it, however, was effective in reducing elevated cholesterol by 16.5 and 20.8% and LPO by 12.9 and 35.5% at 2.9 and 5.7 mg/kg, respectively. Data suggest that COX-2 inhibitors may be effective in controlling hypercholesterolemia and peroxidative changes associated with liver injury.

Pharmacologic inhibition of the renin-angiotensin system did not attenuate hepatic toxicity induced by carbon tetrachloride in rats.

The renin-angiotensin system (RAS) subserves vital physiological functions and also implicated in certain pathological states. Modulation of this system has been proposed in recent studies to be a promising strategy in treating liver fibrosis. We investigated the effect of the pharmacologic inhibition of RAS with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in CCl(4)-induced liver injury with a view to ascertaining the chemopreventive benefit. Fifty-six Wistar albino rats were divided into eight experimental groups of seven rats/group. Groups 1-4 received normal saline (10 ml/kg), enalapril (0.6 mg/kg), losartan (1.4 mg/kg) and CCl(4) (80 mg/kg), respectively. Groups 5-8 were pretreated with enalapril (0.3 mg/kg), enalapril (0.6 mg/kg), losartan (0.7 mg/kg) and losartan (1.4 mg/kg) 1 hour before CCl(4) administration. Experiment lasted 11 days and dosing was via oral route. Rats were killed 24 hours after the last treatment. Serum activities of alkaline phosphatase, aspartate and alanine aminotransferases increased significantly (p < 0.05) by 46.0%, 90.6% and 122.3%, respectively, with severe hepatic centrilobular necrosis, fatty infiltration and increase in liver weight (p < 0.05) in the CCl(4)-treated rats. Enalapril (0.6 mg/kg) and losartan (1.4 mg/kg) significantly (p < 0.05) increased aspartate aminotransferase activity by 37.0% and 94.7% and produced mild centrilobular and periportal hepatic necrosis, respectively, with enalapril significantly (p < 0.05) increasing liver weight. Serum total cholesterol, triglyceride, albumin and total protein did not change significantly in these rats. Also, glutathione, malondialdehyde and uric acid levels were not significantly altered. Enalapril and losartan failed to attenuate liver injury associated with CCl(4) treatment. Although both drugs did not significantly alter serum biochemistry in the CCl(4)-treated rats, they however produced slight elevations in biomarkers of liver function and appear to worsen liver histopathology. Overall, the chemopreventive benefits of RAS inhibitors in liver disease remain doubtful and should be used with caution during hepatic dysfunction.