Background: Environmental lead (Pb) exposure is a public health problem in many developing and in... more Background: Environmental lead (Pb) exposure is a public health problem in many developing and industrialized countries. Being a petrochemical industry-based economy, Pb levels are expected to be high in Kuwait but systematic data on population exposure are lacking. This study aimed at determining the prevalence of Pb toxicity in adolescents in Kuwait.Methods: Adolescents (N=1385; age range 11-16 years) were cross-sectionally selected from public middle schools from all Governorates of Kuwait, utilizing multi-stage cluster random sampling. Pb in whole blood was analyzed by inductively coupled plasma mass spectrometry. Pb levels among Governorates and genders were compared by median test and the prevalence of Pb levels above the CDC cutoff (≥5 µg/dL) was estimated by x2 test. Multiple logistic regression was used for association between prevalence of high Pb levels and Governorate.Results: Median (IQR) Pb was 5.1(3.6 – 7.1) µg/dL [4.9 (3.8 6.5) µg/dL in males and 5.4 (3.3-7.6) µg/dL ...
Abstract PECOLE (Peer-to-pEer COLlaborative Environment) is a fully decentralized multimedia coll... more Abstract PECOLE (Peer-to-pEer COLlaborative Environment) is a fully decentralized multimedia collaborative environment that supports a wide range of collaborative multimedia applications, including chat, shared browsing, shared telepointer, multipoint-to-multipoint ...
High blood lead levels (BLL) in pregnancy are associated with poor pregnancy outcome and neuro-be... more High blood lead levels (BLL) in pregnancy are associated with poor pregnancy outcome and neuro-behavioral deficits in infants. We investigated the prevalence of high BLL in pregnant women and its impact on pregnancy outcome in Kuwait. Blood from 194 mother-infant pairs were analyzed for lead by Atomic Absorption Spectrophotometry. Data were collected on birth weight, crown-heel length, head circumference, APGAR score, gestational age, and placental weight. Results revealed that 28% of pregnant women and 58% of infants had BLL >10 g/dL. Cord BLL was significantly higher than maternal BLL (10.92 vs. 5.77 g/dL, p < .001). Maternal BLL was not significantly associated with any of the outcome variables tested, whereas, cord BLL was a significant negative predictor of APGAR score only in boys. A significant proportion of pregnant women and their children in Kuwait have lead levels well above the safety limit, which is a matter of public health concern.
A hollow slot has been radio frequency electrically excited to generate a discharge plasma at atm... more A hollow slot has been radio frequency electrically excited to generate a discharge plasma at atmospheric pressure. This newly developed micro-plasma device consists of a rf driven hollow electrode, with a long narrow slot of length 3-35 cm, width 0.2 -1.5 mm, and depth 0.7 mm, and a solid transverse electrode which is electrically grounded and placed parallel to the
JPMA. The Journal of the Pakistan Medical Association, 2003
To evaluate association of blood lead levels with pregnancy outcome in the obstetrics and gynaeco... more To evaluate association of blood lead levels with pregnancy outcome in the obstetrics and gynaecology unit. Blood lead levels were measured in 73 pregnant women at the time of delivery and assessed its association with pregnancy outcome. Mean maternal lead level was 9.91+/-4.44 mg/dL (range 2.28-36.35 mg/dL). Mothers of boys had significantly higher (p=0.013, one-tailed t test) blood lead levels (11.05+/-5.19) when compared to mothers of girls (8.74+/-3.18 mg/dL. Maternal lead levels at the time of delivery showed no association with gestational age, birth weight, recumbent length, or head circumference.
Some of the tryptophan catabolites produced through the kynurenine pathway (KP), and more particu... more Some of the tryptophan catabolites produced through the kynurenine pathway (KP), and more particularly the excitotoxin quinolinic acid (QA), are likely to play a role in the pathogenesis of Alzheimer's disease (AD). We have previously shown that the KP is over activated in AD brain and that QA accumulates in amyloid plaques and within dystrophic neurons. We hypothesized that QA in pathophysiological concentrations affects tau phosphorylation. Using immunohistochemistry, we found that QA is co-localized with hyperphosphorylated tau (HPT) within cortical neurons in AD brain. We then investigated in vitro the effects of QA at various pathophysiological concentrations on tau phosphorylation in primary cultures of human neurons. Using western blot, we found that QA treatment increased the phosphorylation of tau at serine 199/202, threonine 231 and serine 396/404 in a dose dependent manner. Increased accumulation of phosphorylated tau was also confirmed by immunocytochemistry. This in...
Serine/threonine protein phosphatases regulate several key cellular events in the brain, includin... more Serine/threonine protein phosphatases regulate several key cellular events in the brain, including learning and memory. These enzymes, when over-activated, are known to function as a constraint on learning and memory. We investigated whether these phosphatases are implicated in lead (Pb)-induced deficits in learning and memory. Wistar rat pups were exposed to 0.2% Pb-acetate via their dams' drinking water from postnatal day (PND) 1-21 and directly in drinking water until PND 30. Pb levels in blood, brain and hippocampus were measured and expression of PP1, PP2A, PP2B and PP5 in hippocampus was analyzed. Total phosphatase activity, and PP1 and PP2A activities were determined. Tau phosphorylation at various epitopes was determined by Western blot. Spatial learning and memory was determined by Morris water maze test. Pb exposure significantly increased levels of Pb in blood, brain and hippocampus, reduced the number of synapses in hippocampus and impaired learning and long-term memory (LTM). Short-term memory (STM) was only affected in rats at PND21. Pb exposure increased the expression and activity of PP1 and decreased phosphorylation of tau at threonine-231 in hippocampus at both PND21 and PND30. Pb-induced phosphorylation of tau at serine-199/202 (AT8) paralleled with PP2A activity; at PND21 PP2A activity increased and AT8 phosphorylation decreased; at PND30 PP2A activity decreased and AT8 phosphorylation increased. Increased PP1 activity in hippocampus by Pb is associated with learning and LTM impairment, whereas, increased PP2A activity is associated with STM impairment. These findings suggest the overactivation of PP1 and PP2A, together with changes in tau phosphorylation, as a potential mechanism of lead-induced deficits in learning and memory.
The majority of children in Karachi have blood lead levels above 10 micrograms/dl, the upper safe... more The majority of children in Karachi have blood lead levels above 10 micrograms/dl, the upper safety limit set by the United States Centers for Disease Control and Prevention. A study was undertaken to evaluate chronic lead exposure in children by measuring lead levels in shed primary teeth collected from primary school children in Karachi. A total of 309 teeth were collected from nine different schools, and analysed for lead content by atomic absorption spectrophotometry with electrothermal atomization. The mean (SD) age of the subjects was 7.6 (1.2) years and the mean lead level was 5.78 micrograms/g of whole tooth (dry weight), ranging from 0.42 to 39.75 micrograms/g. Incisor teeth had a significantly higher mean (SD) lead level, 6.42 (4.19) micrograms/g, than canines and molars which contained 4.91 (5.12) micrograms and 4.50 (2.67) micrograms lead whole tooth (dry weight), respectively. Significant differences were observed between different schools. No difference was observed between boys and girls and the accumulation of lead in teeth was not correlated with chronological age.
Background: Environmental lead (Pb) exposure is a public health problem in many developing and in... more Background: Environmental lead (Pb) exposure is a public health problem in many developing and industrialized countries. Being a petrochemical industry-based economy, Pb levels are expected to be high in Kuwait but systematic data on population exposure are lacking. This study aimed at determining the prevalence of Pb toxicity in adolescents in Kuwait.Methods: Adolescents (N=1385; age range 11-16 years) were cross-sectionally selected from public middle schools from all Governorates of Kuwait, utilizing multi-stage cluster random sampling. Pb in whole blood was analyzed by inductively coupled plasma mass spectrometry. Pb levels among Governorates and genders were compared by median test and the prevalence of Pb levels above the CDC cutoff (≥5 µg/dL) was estimated by x2 test. Multiple logistic regression was used for association between prevalence of high Pb levels and Governorate.Results: Median (IQR) Pb was 5.1(3.6 – 7.1) µg/dL [4.9 (3.8 6.5) µg/dL in males and 5.4 (3.3-7.6) µg/dL ...
Abstract PECOLE (Peer-to-pEer COLlaborative Environment) is a fully decentralized multimedia coll... more Abstract PECOLE (Peer-to-pEer COLlaborative Environment) is a fully decentralized multimedia collaborative environment that supports a wide range of collaborative multimedia applications, including chat, shared browsing, shared telepointer, multipoint-to-multipoint ...
High blood lead levels (BLL) in pregnancy are associated with poor pregnancy outcome and neuro-be... more High blood lead levels (BLL) in pregnancy are associated with poor pregnancy outcome and neuro-behavioral deficits in infants. We investigated the prevalence of high BLL in pregnant women and its impact on pregnancy outcome in Kuwait. Blood from 194 mother-infant pairs were analyzed for lead by Atomic Absorption Spectrophotometry. Data were collected on birth weight, crown-heel length, head circumference, APGAR score, gestational age, and placental weight. Results revealed that 28% of pregnant women and 58% of infants had BLL >10 g/dL. Cord BLL was significantly higher than maternal BLL (10.92 vs. 5.77 g/dL, p < .001). Maternal BLL was not significantly associated with any of the outcome variables tested, whereas, cord BLL was a significant negative predictor of APGAR score only in boys. A significant proportion of pregnant women and their children in Kuwait have lead levels well above the safety limit, which is a matter of public health concern.
A hollow slot has been radio frequency electrically excited to generate a discharge plasma at atm... more A hollow slot has been radio frequency electrically excited to generate a discharge plasma at atmospheric pressure. This newly developed micro-plasma device consists of a rf driven hollow electrode, with a long narrow slot of length 3-35 cm, width 0.2 -1.5 mm, and depth 0.7 mm, and a solid transverse electrode which is electrically grounded and placed parallel to the
JPMA. The Journal of the Pakistan Medical Association, 2003
To evaluate association of blood lead levels with pregnancy outcome in the obstetrics and gynaeco... more To evaluate association of blood lead levels with pregnancy outcome in the obstetrics and gynaecology unit. Blood lead levels were measured in 73 pregnant women at the time of delivery and assessed its association with pregnancy outcome. Mean maternal lead level was 9.91+/-4.44 mg/dL (range 2.28-36.35 mg/dL). Mothers of boys had significantly higher (p=0.013, one-tailed t test) blood lead levels (11.05+/-5.19) when compared to mothers of girls (8.74+/-3.18 mg/dL. Maternal lead levels at the time of delivery showed no association with gestational age, birth weight, recumbent length, or head circumference.
Some of the tryptophan catabolites produced through the kynurenine pathway (KP), and more particu... more Some of the tryptophan catabolites produced through the kynurenine pathway (KP), and more particularly the excitotoxin quinolinic acid (QA), are likely to play a role in the pathogenesis of Alzheimer's disease (AD). We have previously shown that the KP is over activated in AD brain and that QA accumulates in amyloid plaques and within dystrophic neurons. We hypothesized that QA in pathophysiological concentrations affects tau phosphorylation. Using immunohistochemistry, we found that QA is co-localized with hyperphosphorylated tau (HPT) within cortical neurons in AD brain. We then investigated in vitro the effects of QA at various pathophysiological concentrations on tau phosphorylation in primary cultures of human neurons. Using western blot, we found that QA treatment increased the phosphorylation of tau at serine 199/202, threonine 231 and serine 396/404 in a dose dependent manner. Increased accumulation of phosphorylated tau was also confirmed by immunocytochemistry. This in...
Serine/threonine protein phosphatases regulate several key cellular events in the brain, includin... more Serine/threonine protein phosphatases regulate several key cellular events in the brain, including learning and memory. These enzymes, when over-activated, are known to function as a constraint on learning and memory. We investigated whether these phosphatases are implicated in lead (Pb)-induced deficits in learning and memory. Wistar rat pups were exposed to 0.2% Pb-acetate via their dams' drinking water from postnatal day (PND) 1-21 and directly in drinking water until PND 30. Pb levels in blood, brain and hippocampus were measured and expression of PP1, PP2A, PP2B and PP5 in hippocampus was analyzed. Total phosphatase activity, and PP1 and PP2A activities were determined. Tau phosphorylation at various epitopes was determined by Western blot. Spatial learning and memory was determined by Morris water maze test. Pb exposure significantly increased levels of Pb in blood, brain and hippocampus, reduced the number of synapses in hippocampus and impaired learning and long-term memory (LTM). Short-term memory (STM) was only affected in rats at PND21. Pb exposure increased the expression and activity of PP1 and decreased phosphorylation of tau at threonine-231 in hippocampus at both PND21 and PND30. Pb-induced phosphorylation of tau at serine-199/202 (AT8) paralleled with PP2A activity; at PND21 PP2A activity increased and AT8 phosphorylation decreased; at PND30 PP2A activity decreased and AT8 phosphorylation increased. Increased PP1 activity in hippocampus by Pb is associated with learning and LTM impairment, whereas, increased PP2A activity is associated with STM impairment. These findings suggest the overactivation of PP1 and PP2A, together with changes in tau phosphorylation, as a potential mechanism of lead-induced deficits in learning and memory.
The majority of children in Karachi have blood lead levels above 10 micrograms/dl, the upper safe... more The majority of children in Karachi have blood lead levels above 10 micrograms/dl, the upper safety limit set by the United States Centers for Disease Control and Prevention. A study was undertaken to evaluate chronic lead exposure in children by measuring lead levels in shed primary teeth collected from primary school children in Karachi. A total of 309 teeth were collected from nine different schools, and analysed for lead content by atomic absorption spectrophotometry with electrothermal atomization. The mean (SD) age of the subjects was 7.6 (1.2) years and the mean lead level was 5.78 micrograms/g of whole tooth (dry weight), ranging from 0.42 to 39.75 micrograms/g. Incisor teeth had a significantly higher mean (SD) lead level, 6.42 (4.19) micrograms/g, than canines and molars which contained 4.91 (5.12) micrograms and 4.50 (2.67) micrograms lead whole tooth (dry weight), respectively. Significant differences were observed between different schools. No difference was observed between boys and girls and the accumulation of lead in teeth was not correlated with chronological age.
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