Influence of nanosilver on osmotic fragility responses of erythrocyte membrane following Na+/K+-ATPase blockade

Background: The molecular mechanisms and overt effects of nanoparticle-induced changes in red blood cells (RBCs) structure and function across membrane cell lines remain unclear despite the increasing use and application in nanomedicine. The aim of this study was to assess the impact of nanosilver exposure on osmoregulation of red cell membrane fragility in digoxin-induced Na+-K+ATPase blockade in vitro. Materials and Method: Samples from 50 subjects were obtained from consenting asymptomatic adults: male and female HbAA haemoglobin genotype. After separation and washing of erythrocytes, the samples were divided into three sets with each sample treated in duplicate with graded percentage concentrations of phosphate buffer solutions (0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, and 0.1). The second and third set of samples were incubated with 0.05ml of erythrocytes, 1 ml phosphate buffer saline and 1 ml nanosilver or digoxin of 25 mg/ml. Thereafter, the content of each test tube was incubated for 1 hour and 3 hours respectively. The absorbance was recorded after 30mins incubation for each set with standard spectrophotometer at 540 nm wavelength. Haemolysis in each tube was recorded and expressed as percentage of the absorbance in distilled water. The average values recorded were plotted against the different  concentrations used. Results: Erythrocytes from the sample incubated with nanosilver had significantly increased osmotic lysis compared with the untreated cells in rate-depended manner (P<0.05). Similar pattern was observed with digoxin pre-incubated cells. The mean osmotic fragility (MOF) index of the untreated, nanosilver and digoxin pre-incubated cells was in the order: digoxin>nanosilver>untreated. Conclusion: exposure of RBCs to nanosilver and in Na+/K+ATPase blockade may result in increased hemolytic effects by multifactorial cell membrane-mediated processe

Impact of Noise on Hearing Amongst Commercial Motor Bike Riders in Benin- City, Nigeria.

The ambient noise level and noise-induced hearing impairment (NIHI) in 200 motorbike riders from six motorbike parks were evaluated. All were males aged between 20- 62 years. Subjects were sampled using a cluster sampling technique. Parameters measured were environmental noise using the noise meter (peters) and hearing function using an audiometer (amplaid). A control group of 150 males was selected from amongst the staff of the University of Benin Teaching Hospital and students of University of Benin after informed consent was obtained. The mean ambient noise for motor bike riders was 90 \ub110 dB a level significantly (x=0.000), higher than the International Standard Organization (ISO) standard of 60dB. That for control group was 50 \ub1 10dB. While there was no NIHI in control group, a significant hearing impairment for both air conduction (AC) and Bone conduction (BC) was observed in the study group. Unlike previous observations AC and BC impairment were predominantly in the left ear. Development of both AC and BC impairments increased with period of exposure. Environment noise impacts adversely on hearing and is a risk factor in commercial motorbike riders. Development of NIHI is significantly higher in the left ear than right unlike in other occupations

Peak Expiratory Flow Rate and Respiratory Symptoms Following Chronic Domestic Wood Smoke Exposure in Women in Edo, Nigeria

Peak expiratory flow rate (PEFR) of 350 rural women aged (20-70 years) in Edo State, Nigeria who actively used wood as a source of fuel for cooking was measured. The height, chest circumference, weight and blood pressure of the women were also measured. Respiratory symptoms of cough with sputum production, dyspnea, wheezing, chest tightness and chest pain were markedly elevated in the subjects compared to control. The mean PEFR value for the wood exposed women (289±19.6L/mm) was significantly lower than control (364±17.2L/mm), P <0.05.The predicted PEFR values for both Africans and Caucasians were significantly higher than the measured values. The PEFR decreased with increase in years of exposure to wood smoke and the fall was neither accounted for by age nor height. The increase in respiratory symptoms and the low PEFR values observed for women exposed to wood smoke, the severity of which is related to exposure time indicate that prolonged exposure to wood smoke is capable of impairing lung functions

Peak expiratory flow rate and respiratory symptoms following chronic domestic wood smoke exposure in women in Edo, Nigeria

Peak expiratory flow rate (PEFR) of 350 rural women aged (20-70 years) in Edo State, Nigeria who actively used wood as a source of fuel for cooking was measured. The height, chest circumference, weight and blood pressure of the women were also measured. Respiratory symptoms of cough with sputum production, dyspnea, wheezing, chest tightness and chest pain were markedly elevated in the subjects compared to control. The mean PEFR value for the wood exposed women (289±19.6L/mm) was significantly lower than control (364±17.2L/mm), P <0.05.The predicted PEFR values for both Africans and Caucasians were significantly higher than the measured values. The PEFR decreased with increase in years of exposure to wood smoke and the fall was neither accounted for by age nor height. The increase in respiratory symptoms and the low PEFR values observed for women exposed to wood smoke, the severity of which is related to exposure time indicate that prolonged exposure to wood smoke is capable of impairing lung functions

Impact of Noise on Hearing Amongst Commercial Motor Bike Riders in Benin- City, Nigeria.

The ambient noise level and noise-induced hearing impairment (NIHI) in 200 motorbike riders from six motorbike parks were evaluated. All were males aged between 20- 62 years. Subjects were sampled using a cluster sampling technique. Parameters measured were environmental noise using the noise meter (peters) and hearing function using an audiometer (amplaid). A control group of 150 males was selected from amongst the staff of the University of Benin Teaching Hospital and students of University of Benin after informed consent was obtained. The mean ambient noise for motor bike riders was 90 ±10 dB a level significantly (x=0.000), higher than the International Standard Organization (ISO) standard of 60dB. That for control group was 50 ± 10dB. While there was no NIHI in control group, a significant hearing impairment for both air conduction (AC) and Bone conduction (BC) was observed in the study group. Unlike previous observations AC and BC impairment were predominantly in the left ear. Development of both AC and BC impairments increased with period of exposure. Environment noise impacts adversely on hearing and is a risk factor in commercial motorbike riders. Development of NIHI is significantly higher in the left ear than right unlike in other occupations

Impact of noise on hearing amongst commercial motor bike riders in Benin- City, Nigeria.

The ambient noise level and noise-induced hearing impairment (NIHI) in 200 motorbike riders from six motorbike parks were evaluated. All were males aged between 20- 62 years. Subjects were sampled using a cluster sampling technique. Parameters measured were environmental noise using the noise meter (peters) and hearing function using an audiometer (amplaid). A control group of 150 males was selected from amongst the staff of the University of Benin Teaching Hospital and students of University of Benin after informed consent was obtained. The mean ambient noise for motor bike riders was 90 ±10 dB a level significantly (x=0.000), higher than the International Standard Organization (ISO) standard of 60dB. That for control group was 50 ± 10dB. While there was no NIHI in control group, a significant hearing impairment for both air conduction (AC) and Bone conduction (BC) was observed in the study group. Unlike previous observations AC and BC impairment were predominantly in the left ear. Development of both AC and BC impairments increased with period of exposure. Environment noise impacts adversely on hearing and is a risk factor in commercial motorbike riders. Development of NIHI is significantly higher in the left ear than right unlike in other occupations