Biomedical subjects

Y M Abdulrazzaq

Publications and source records attributed to Y M Abdulrazzaq.

At least 19 recordsLinked to original sources

PubMed2005

United Arab Emirates: communities and community genetics.

The UAE society is cosmopolitan, but the indigenous inhabitants are traditional with puritanical values despite their exposure to other vastly different cultures and habits. Marriages between consanguineous couples are still the norm rather than the exception. As a result, there is a high frequency of genetic disorders, particularly autosomal recessive types. Despite the high frequency of genetic disorders like haemoglobinopathies and others characteristically found in this population, genetic services are inadequate. Screening for certain disorders like thalassaemia are not applied on a wide scale. Abortion is illegal, and therefore, prenatal diagnosis or preconception tests are not done. With the absence of a good national database, deficiency of genetic services and absence of preventative alternatives for carrier couples, genetic counsellors find it difficult to advice pragmatic solutions to issues relating to genetic diseases. This paper reviews common genetic problems in the UAE with special emphasis on available genetic services and support to families with children with inherited disorders. Existing barriers to the improvement of clinical services by prenatal counselling are also discussed.

Arabs↗

PubMed2003

Experimental studies on reproductive toxicologic effects of lamotrigine in mice.

BACKGROUND: Virtually all antiepileptic drugs (AED) tested so far have been found to be teratogenic. The second generation AED possess a number of therapeutic advantages over the older ones. There are, however, very little data on their effects on embryonic development. A recent report suggests that lamotrigine (LTG) can be teratogenic to human fetuses. With only a few cases of prenatal exposure to LTG in the record, however, it has not been possible to establish a recognizable pattern of malformations in the infants of LTG-treated mothers. OBJECTIVES: The objectives of the present study were to evaluate the reproductive toxic effects of LTG . RESULTS: Single (50-200 mg/kg) or multiple doses (25, 50, 75 mg/kg) of LTG were administered by intraperitoneal (i.p.) injection (note that the therapeutic administration is oral) to groups of TO mice on gestation day (GD) 7 or 8. Fetuses were collected on GD 18. Maternal toxic effects including a dose-related mortality, a high incidence of abortion, embryo lethality, congenital malformations and intrauterine growth retardation (IUGR) were observed in the LTG-treated group. Administration of LTG in multiple low doses resulted in a better maternal survival and increased incidence of embryonic resorption and malformations with increasing dose; IUGR was significant but not dose-dependent. The malformations characteristic of the LTG multiple low dose group fetuses included maxillary-mandibular hypoplasia, exencephaly, cleft palate, median facial cleft, urogenital anomalies and varying degrees of caudal regression. Skeletal malformations and developmental delay of the skeleton were observed both in single and multiple dose groups. CONCLUSIONS: The results of this study indicate that LTG administered i.p. at high doses can induce intrauterine growth retardation and at low multiple doses causes a dose-dependent increase in embryonic resorption, craniofacial and caudal malformations as well as maternal toxicity in the mouse. Previous studies in other laboratories have used oral route of exposure and concluded that there are no teratogenic effects of LTG at dose levels that are not maternally toxic.

Abnormalities, Drug-Induced↗

PubMed2002

Group B streptococcal serotype distribution of isolates from colonized pregnant women at the time of delivery in United Arab Emirates.

OBJECTIVE: To determine the maternal colonization rate with group B streptococcus (GBS) and to identify the most frequent GBS serotypes occurring in UAE women during labour. STUDY DESIGN: From February 1998 to January 1999, five hundred and sixty three pregnant women from a similar socio-economic and ethnic population were enrolled for the study. High vaginal swab cultures for GBS were obtained at the time of admission for delivery. Isolates were classified according to their capsular polysaccharide types (Ia, Ib, Ic, II-V) and c protein antigen compound. RESULTS: Fifty-seven (10.1%) of 563 mothers were found to be carriers of GBS. Among the isolates, serotype IV (26.3%) predominated followed by type Ia (21.0%), type III (17.6%), type V (12.3%) and nontypeable, which accounted for 15.8%. CONCLUSIONS: In view of the unknown status for GBS carrier rates in our community, this study suggests that about 10% of UAE women are colonized with group B streptococcus at delivery. The serotype distribution of the isolates in this population is different than those reported elsewhere with type IV predominating followed by type Ia and III.

Adult↗

PubMed2001

Placental transfer of vigabatrin (gamma-vinyl GABA) and its effect on concentration of amino acids in the embryo of TO mice.

BACKGROUND: The mechanism of the teratogenicity of vigabatrin (VGB) is unknown. The objectives of this study were to determine the placental transfer of VGB and to evaluate the effect of VGB on maternal, placental, and fetal concentrations of amino acids. METHODS: A single dose of 400 mg/kg VGB in physiological saline was administered intraperitoneally to a group of Theiler outbred (TO) mice on gestational day (GD) 10. The controls received a proportionate volume of saline. Maternal blood samples, embryos, and placentas were collected at 3.5, 6.0, and 9.0 hr after treatment and their total amino acid concentrations determined in an ion-exchange amino acid analyzer. RESULTS: At 3.5 hr, there was a decrease in concentrations of some amino acids in the blood, placenta, and embryos of VGB-treated mice, but the decrease in methionine was most marked. gamma-aminobutyric acid (GABA) was significantly higher in the VGB group in both the embryos and the placentas at 3.5 hr but at 6.0 and 9.0 hr the differences were not significant. Vigabatrin levels were higher in the placenta than in the embryo at 3.5 hr, but at 6.0 hr there was an overlap of the VGB peak with that of tryptophan with very much lower levels than at 3.5 hr. At 9.0 hr, there was no vigabatrin peak in either the placenta or the embryo. CONCLUSIONS: Maternal exposure to VGB results in peak levels of the drug after 3.5 hr in the placenta and embryo. Methionine concentration is most severely affected in VGB-treated mothers, placentas, and fetuses. We speculate that this deficiency could be a possible mechanism for the teratogenic effects of vigabatrin.

4-Aminobutyrate Transaminase↗

PubMed2001

Determination of amino acids by ion-exchange chromatography on filter paper spotted blood samples stored at different temperatures and for different periods: comparison with capillary and venous blood.

OBJECTIVE: To determine whether the well-established filter paper spotted blood method used for the determination of some amino acids could be reliably used to measure all amino acids and whether amino acid results thus obtained are reproducible and comparable to the results obtained by measuring plasma amino acids in either capillary or venous blood. METHODS: This is a prospective study in which blood samples from a finger-prick were collected in capillary tubes and at the same time blotted on filter papers; another sample was taken from a vein, from 19 healthy volunteers aged between 18 and 24 yr after a strict 12-h overnight fast. Another 9 healthy adult volunteers provided blood samples on filter papers for the storage study; 9 samples were analyzed immediately; 9, 8 and 4 samples were stored at -20 degrees C, -4 degrees C and room temperature respectively and analyzed after 14 days; 8 samples stored at -20 degrees C were analyzed after 4 weeks. RESULTS: Intra-sample reproducibility in the filter paper blood from the same individual was found to be mostly less than 20%, while for the capillary blood was less than 5%. The greatest variability was in cystine and methionine. There was no significant difference between results obtained from capillary blood and from venous blood, but there was a significant difference between amino acid concentrations in venous and capillary blood on the one hand and filter paper blood on the other. Storage at different temperatures and for a varied period of time showed little change except in serine, glutamate, ornithine, histidine, cystine and methionine. There was a 30% decrease in concentrations of most amino acids in filter paper blood when compared to capillary or venous blood probably because of loss in the extraction process. CONCLUSION: A new set of values for amino acids in filter paper blood in normal individuals is presented. Blood spotted filter paper could be used to screen practically all inborn errors of amino acid metabolism.

Adolescent↗

PubMed1999

Diversity in expression of glucose-6-phosphate dehydrogenase deficiency in females.

The aims of this study were to determine the prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency in the United Arab Emirates (UAE), to describe the different mutations in the population, to determine its prevalence, and to study inheritance patterns in families of G6PD-deficient individuals. All infants born at Tawam Hospital, Al-Ain, UAE from January 1994 to September 1996 were screened at birth for their G6PD status. In addition, those attending well-baby clinics during the period were also screened for the disorder. Families of 40 known G6PD-deficient individuals, selected randomly from the records of three hospitals in the country, were assessed for G6PD deficiency. Where appropriate, this was followed by definition of G6PD mutations. Of 8198 infants, 746 (9.1%), comprising 15% of males and 5% of females tested, were found to be G6PD deficient. A total of 27 families were further assessed: of these, all but one family had the nt563 Mediterranean mutation. In one family, two individuals had the nt202 African mutation. The high manifestation of G6PD deficiency in women may be due to the preferential expression of the G6PD-deficient gene and X-inactivation of the normal gene, and/or to the presence of an 'enhancer' gene that makes the expression of the G6PD deficiency more likely. The high level of consanguinity which, theoretically, should result in a high proportion of homozygotes and consequently a higher proportion of females with the deficiency, was not found to be a significant factor.

Consanguinity↗

PubMed1999

Pattern of central nervous system anomalies in a population with a high rate of consanguineous marriages.

Nine thousand six hundred and ten births were prospectively studied in the three major hospitals in Al-Ain, United Arab Emirates (UAE) between October 1995 and January 1997. Babies suspected of, or diagnosed, as having central nervous system (CNS) abnormalities were evaluated by a neonatologist, a clinical geneticist and a pediatric neurologist. Brain computerized tomography/magnetic resonance imaging (CT/MRI) was performed on all babies suspected of having CNS abnormalities. In addition, metabolic screening and chromosome analysis were also performed when indicated. Of the 225 babies with congenital anomalies identified, 31 had CNS abnormalities (3.2/1000). Syndromic abnormalities of the CNS were present in 13 cases (42%), chromosomal abnormalities in one case (3.2%) and the rest included: neural tube defect (NTD) in 11 cases (36%), holoprosencephaly in two cases (6.4%) and hydrocephalus in four cases (12.9%). Detailed analysis of the syndromic types revealed that out of the 13 cases, 12 were inherited as autosomal recessive (AR) and in one case the inheritance was undetermined. Consanguinity with high level of inbreeding was present in 12 cases and the majority of the syndromes identified were extremely rare. The study indicates that CNS anomalies are fairly common in the UAE, particularly, the recessive syndromic types. Careful and detailed analysis of such anomalies is required so that accurate genetic advice can be given.

Central Nervous System↗

PubMed1999

A syndrome of immune complex glomerulonephritis and ophthalmic abnormalities.

Two sibs (one male and one female) suffering from a combination of immune complex glomerulonephritis and various ophthalmologic disorders are presented. The two cases belong to a family in which the parents are not related and seven sibs are affected, three females and a male with the combination, and three males with severe ophthalmological changes and proteinuria. Clinically, case 2 had only ophthalmological manifestations but renal biopsy findings were similar to those of case 1, which could mean that all the others with eye abnormalities also had renal disease. Although there are several reports of combinations of eye and renal disorders, the sibs reported here do not fit into any of the known syndromes.

Abnormalities, Multiple↗

PubMed1997

Teratogenic effects of vigabatrin in TO mouse fetuses.

Vigabatrin (VGB) is a relatively recently introduced antiepileptic drug that enhances the brain levels of gamma aminobutyric acid (GABA). Few data on its teratogenic effects appear to have been reported. Our objective was to determine if VGB was teratogenic in the TO mouse. Single doses of 300-600 mg/kg of VGB dissolved in saline were administered intraperitoneally (IP) to groups of TO mice on one of gestation days (GD) 7-12. The controls were saline treated or untreated. No maternal toxic effects were observed in the 300 or 450 mg/kg groups, and the 600 mg/kg dose was totally lethal to the mothers. Fetuses were collected on GD 18. Both 300 and 450 mg/kg doses induced a consistently significant intrauterine growth retardation irrespective of the developmental stage at administration. VGB did not augment the spontaneous incidence of neural tube defects characteristic of this strain, but accelerated destruction of the brain in spontaneous exencephalic embryos. Mandibular and maxillary hypoplasia, arched palate, cleft palate (two cases), limb defects (one case), and exomphalos were observed in the malformed fetuses. The high incidence of exomphalos appears to be a unique result of VGB treatment. Alizarin red-S/alcian blue-stained, skeletons revealed hypoplasia of mid facial bones, stage-dependent increase in the frequency of cervical and lumbar ribs, rib fusion, and sternal and vertebral malformations in the drug-treated fetuses. Middle and distal phalanges of the forepaw and mid phalanges and tarsals of the hindpaw failed to ossify in a significant number of experimental fetuses. Homeotic shift in terms of presacral vertebral number and a high incidence of lumbar and cervical ribs in the treated group are suggestive of treatment-related alterations in gene expression. In view of the paucity of human and animal data on the reproductive toxicologic effects of VGB, the results of the present study assume particular importance and suggest that VGB should be used in pregnancy with extreme caution.

Abnormalities, Drug-Induced↗

PubMed1997

Abnormal myelination in peroxisomal isolated dihydroxyacetonephosphate acyltransferase deficiency.

The cranial magnetic resonance imaging findings in three siblings with nonrhizomelic chondrodysplasia punctata due to isolated dihydroxyacetonephosphate acyltransferase (DHAP-AT) deficiency are reported. Areas of high signal intensity in a patchy distribution on the T2-weighted images were detected in the centrum semiovale in the eldest patient (a 6-year-old girl). The white matter of the second child (a 5-year-old boy) was spared, whereas the youngest sibling (a 2-year-old boy) manifested very severe white matter abnormalities. DHAP-AT catalyzes the first step in the synthesis of plasmalogens, which are major constituents of myelin. Defective plasmalogen synthesis may have contributed to abnormal myelin formation in 2 patients. Because the clinical presentation of the child without detectable defect in myelination was similar to that of his siblings, the neurologic signs observed in isolated DHAP-AT deficiency cannot be attributed solely to the disturbances in the myelin formation.

Acyltransferases↗

PubMed1997

Consanguineous marriages in the United Arab Emirates.

This study examines the frequency of consanguineous marriage and the coefficient of inbreeding in the United Arab Emirates (UAE). The study was conducted in Al Ain and Dubai cities between October 1994 and March 1995. A sample of 2033 married UAE females aged 15 years and over participated. The degree of consanguinity between each female and her spouse, and the degree of consanguinity between their parents were recorded. The rate of consanguinity in the present generation was high (50.5%) with a coefficient of inbreeding of 0.0222. The commonest type of consanguineous marriage was between first cousins (26.2%). Double first cousin marriages were common (3.5%) compared to other populations. The consanguinity rate in the UAE has increased from 39% to 50.5% in one generation. The level of consanguinity was higher in Al Ain (54.2%) than in Dubai (40%).

Adult↗

PubMed1997

A study of possible deleterious effects of consanguinity.

The aim of the study was to determine whether consanguineous marriages result in reproductive wastage and an increased incidence of illness in the offspring in a community with a long history of inbreeding and an expected high rate of consanguineous marriage. A representative sample of 2200 women aged > or = 15 years from Dubai and Al Ain, two cities in the United Arab Emirates, representing on the one hand a modern metropolis and on the other a traditional society, were studied. A questionnaire, which included questions on age, parity, gravidity, number of stillbirths, number of abortions, number of children alive, neonatal deaths and specific illnesses in children, was administered by nurses in antenatal and gynaecological clinics in the two cities. The rate of consanguineous marriage was 50.5% and parity, gravidity, ages and number of children were similar in consanguineous and non-consanguineous groups. There was no significant difference in rates of abortion, stillbirth and neonatal death between the two groups. Overall, there was statistically significant higher reproductive wastage in consanguineous couples, but when the category of less than second cousins was excluded from the consanguineous group no difference was found in reproductive wastage between consanguineous and non-consanguineous marriages. Children born to consanguineous unions also had significantly higher incidences of illnesses (37.1%) than those of non-consanguineous unions (29%). The occurrence of malignancies, congenital abnormalities, mental retardation and physical handicap was significantly higher in offspring of consanguineous than non-consanguineous marriages. In conclusion, consanguinity did not result in reproductive wastage, but was found to be an important factor in the causation of specific illnesses in offspring.

Abortion, Spontaneous↗

PubMed1996

Sociodemographic risk factors associated with low birthweight in United Arab Emirates.

This case-control study was undertaken to determine sociodemographic risk factors for low birth weight in Al-Ain (United Arab Emirates) over a 12-month period in 1992-93. A total of 3485 live births occurred of which 293 (8.4%) were low birth weight. The risk factors considered were mother's occupation, house conditions, place of residence (urban or rural), maternal smoking habits, antenatal care, availability of help in the home, maternal BMI and educational status. Multiple logistic regression analysis showed that mother's occupation, maternal smoking, antenatal care, and lack of help in the home were associated with increased risk of low birth weight.

Adolescent↗

PubMed1996

Genetic and environmental factors associated with asthma.

We investigate the familial and environmental risk factors associated with asthma among United Arab Emirates schoolchildren aged 6-14 years. A cross-sectional study of 850 schoolchildren living in both urban and rural areas (average age 9.36 +/- 2.11 years; 46.8% boys, 53.2% girls) was conducted using self-administered questionnaires between October 1992 and May 1993. The population sample had a high prevalence rate of diagnosed asthma (13.6%) and allergic rhinitis (22.9%). The frequency of asthma, allergic rhinitis, and eczema among parents and siblings reflected the same pattern as that seen in the children. Environmental risk factors associated with asthma were pets, medicine, plants, dust storm, physical exercise, humidity, and perfume. All other factors, such as foods, climate, and parental smoking, showed no apparent relation to the development of asthma. The logistic regression analysis showed that parental asthma, plants, perfume, dust storm, humidity, and pets were the only significant predictors after adjusting for sex and other confounding covariates in the model. In conclusion, risk factors for asthma identified by our study are similar to those found in other community-based studies. Consistencies and discrepancies between our findings and those from other studies with respect to asthma risk factors support the hypothesis that asthma is a multifactorial disease related to both familial and environmental influences.

Adolescent↗

PubMed1995

Obstetric risk factors affecting incidence of low birth weight in live-born infants.

This study was conducted to determine the incidence of low birth weight (LBW) in the indigenous population of Al Ain and to identify some risk factors associated with it. The population studied included all consecutive deliveries, occurring in the 3 hospitals in Al Ain City, where almost all deliveries take place, during a 1-year period. When a LBW infant (< 2,500 g) was born, gestational age assessment was made and a questionnaire completed during an interview with the mother. For control, the first baby who weighed more than 2,500 g at birth, following the birth of a LBW was recruited. It was found that a total of 3,485 live births occurred of which 293 were classified as LBW, giving an LBW incidence of 8.4%. Of these, 73 (24.9%) were small for gestational age (< 10th percentile for gestational age). Overall, the mothers of LBW infants were found to be statistically significantly younger in age. The mothers of LBW infants also had a significantly higher number of previous LBW deliveries, twin deliveries and a larger number of premature rupture of membranes. The factors that were not significantly different in the 2 groups were diabetes during pregnancy, chronic hypertension, preeclampsia/eclampsia, occurrence of significant infection during pregnancy, 1st and 2nd trimester bleeding, and antepartum hemorrhage. This is the first comprehensive study on the incidence of LBW infants in the United Arab Emirates. The main obstetric factors responsible for this were found to be age, number of previous LBW babies, premature rupture of membranes and multiple births.

Birth Weight↗

PubMed1995

Pet ownership in the UAE: its effect on allergy and respiratory symptoms.

The aim of this paper was to study the effect of pets and other domestic animals on bronchial asthma among United Arab Emirates (UAE) schoolchildren aged 6-14 years. A cross-sectional study of 850 schoolchildren living in both urban and rural areas (average age 9.36 +/- 2.11 years, 46.8% boys and 53.2% girls) was conducted using self-administered questionnaires between October 1992 and May 1993. Prevalence rate for asthma, rhinitis, wheeze, cough, and eczema in children from families with and without animals were investigated. A total of 40.7% of families studied were found to keep animals in their homes. Children from families with animals were found to have a significantly higher prevalence rate of respiratory symptoms than those without. The prevalence rate for asthma in children with animals was found to be twice that of children without (RR: 2.03; 95% CI: 1.40-2.95). The risk of having chronic cough (RR: 1.93; 95% CI: 1.21-3.10), breathlessness/chest tightness (RR: 2.53; 95% CI: 1.59-4.02), chronic wheeze (RR: 2.10; 95% CI: 1.20-3.67), allergic rhinitis (RR: 1.53; 95% CI: 1.17-2.00) was significantly higher in children with animals than in children without. Similarly, the risk of having eczema (RR: 2.55; 95%, CI: 1.74-3.75) was significantly higher among children with animals than among those without. Overall, there was a highly statistically significant difference in the prevalence of asthma, wheeze, nocturnal cough, eczema, and rhinitis between children in families with animals and those without (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Prevalence of asthma among Emirates school children.

The aim of this study was to determine the prevalence of asthma among United Arab Emirates school children aged 6-14 years. A cross-sectional study of 850 school children living in both urban and rural areas (average age 9.36 +/- 2.11 years, 46.8% boys and 53.2% girls) was conducted using self-administered questionnaires between October 1992 and May 1993. The population sample had a high prevalence rate of diagnosed asthma (13.6%), breathlessness or tightness in chest (9.7%), allergic rhinitis (22.9%), and nocturnal cough (8.9%). Allergic rhinitis was the most frequently seen respiratory illness when compared to other respiratory symptoms. The frequency of asthma, allergic rhinitis and eczema among parents reflected the same pattern as that seen in the children. Prevalence rate of asthma was not significantly higher in fathers (5.9%) than in mothers (5.3%). The differences between the sexes were not significant in any of the age group studied for any of the allergic conditions, except for diagnosed asthma in which the prevalence rate in males was significantly higher than that in females. On the whole, the prevalence rate of all the conditions increased with age. But the frequency of allergic rhinitis symptoms was significantly higher in mothers (16%) than in fathers (10.8%). These results are consistent with those obtained in neighbouring gulf countries and are higher than those of some developed countries, but the differences are not statistically significant.

Adolescent↗

PubMed1994

Association of allergic symptoms in children with those in their parents.

This study investigated the association of asthma, allergic rhinitis, and eczema in United Arab Emirates (UAE) schoolchildren with allergic conditions in their parents. A cross-sectional, population-based study among schoolchildren aged 6-14 years was conducted in Al-Ain City, UAE. The field survey was conducted from October 1992 to May 1993. A questionnaire was distributed to 850 UAE government school students from representative, randomly selected schools with a majority of UAE nationals. The student and both or either of the parents were present during the interview. A detailed clinical history of asthma and wheezing in the target children and a history of asthma and allergic rhinitis in their parents and siblings were obtained. It was found that 13.1% of asthmatic children had mothers with asthma (relative risk (RR) = 2.67; 95% confidence intervals (CI) = 1.65-4.35), and 15.2% had fathers who were asthmatic (RR = 2.85; 95% CI = 1.81-4.49). This contrasted with 4.4% of nonasthmatic children who had fathers with asthma, and 4.1% who had mothers with asthma. A similar pattern was seen with symptoms of allergic rhinitis when it was found that 34.3% of children who had asthma had mothers with allergic rhinitis (RR: 2.74; 95% CI: 1.90-3.94). The corresponding figure for fathers was 12.7% (RR: 0.92; 95% CI: 0.5-1.7). The frequency of either parent of the asthmatic children having allergic rhinitis was 28.6%; for both parents, it was 14.5%. It was also found that asthmatic children had 12.5% of their fathers, 32.8% of their mothers, 26.4% of either of their parents, and 33.3% of both their parents suffering from allergic rhinitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗