Showing papers by "King Saud University published in 1999"

Thymoquinone protects against carbon tetrachloride hepatotoxicity in mice via an antioxidant mechanism.

Abstract: Thymoquinone (TQ) is the major active component of the volatile oil of Nigella sativa seeds The effects of TQ on carbon tetrachloride (CCl4)-induced hepatotoxicity was investigated in male Swiss albino mice Carbon tetrachloride (20 microliters/Kg, ip) injected into mice, induced damage to liver cells and was followed by the increase in serum alanine aminotransferase (ALT) activity after 24 h Oral administration of TQ in a single dose (100 mg/Kg) resulted in significant (p < 0001) protection against the hepatotoxic effects of CCl4 TQ was tested as a substrate for mice hepatic DT-diaphorase in the presence of NADH TQ appears to undergo reduction to dihydrothymoquinone (DHTQ) Reduction rates as a function of protein (liver homogenate) and substrate (TQ) concentrations are reported An apparent K(m) of 01 mM and an apparent Vmax of 74 mumol/min/g liver were measured TQ and DHTQ inhibited the in vitro non-enzymatic lipid peroxidation in liver homogenate (induced by Fe(3+)-ascorbate) in a dose dependent manner In this in vitro model DHTQ was more potent in comparison with TQ and butylated hydroxytoluene (BHT) The IC50 for DHTQ, TQ and BHT were found to be 034, 087 and 058 microM respectively The data suggest that the in vivo protective action of TQ against CCl4-induced hepatotoxicity may be mediated through the combined antioxidant properties of TQ and its metabolite DHTQ

Ocular complications of vernal keratoconjunctivitis.

Abstract: Contexte : L'objectif de l'etude etait d'evaluer les complications oculaires et la perte visuelle chez les patients atteints d'une keratoconjonctivite vernale (KCV). Methodes : Un total de 58 patients consecutifs (52 garcons et 6 filles âges de 8 a 17 ans [âge moyen 12,2 ans]) atteints d'une KCV active aigue, ont ete examines a deux centres de soins tertiaires a Riyadh, en Arabie Saoudite, entre 1995 et 1997. Les patients etaient consideres comme atteints d'une KCV aigue s'ils en presentaient les symptomes depuis au moins deux ans, s'ils avaient un œdeme et un epaississement diffus de la conjonctive palpebrale, avec hypertrophie de la papille (P3) et une conjonctivite papillaire geante, et s'ils avaient une infiltration limbale de 180° ou plus. L'acuite visuelle a ete mesuree au moyen de l'echelle d'acuite visuelle standard de Snellen. La deficience visuelle a ete evaluee en fonction des criteres de l'Organisation mondiale de la sante pour les troubles visuels. La perte visuelle a ete definie comme la cecite ou la deficience visuelle. Resultats: Douze patients (21 %) ont obtenu une acuite visuelle corrigee au mieux dans un œil ou dans les deux yeux de 20/200 ou moins, 20 (34 %) ont obtenu une acuite de 20/50 a 20/200, et 26 (45 %) ont obtenu une vision variant entre 20/20 et 20/50. Les complications oculaires qui ont entraine la perte de la vision chez 32 patients sont les suivantes: une cataracte provoquee par les steroides (8 patients), un glaucome provoque par les steroides (4), des taies de la cornee centrale (7), un astigmatisme irregulier (4), un keratocone (3) et une hyperplasie du tissu limbal (3). De ces 32 patients, 12 presentaient le syndrome de l'oeil sec, qui peut avoir contribue a la perte de la vision. Interpretation: Dans les pays en developpement, une KCV aigue est une maladie qui peut causer la cecite. La perte de la vision peut etre due a des complications au niveau de la cornee, notamment la formation de taies, un astigmatisme et un keratocone, de meme qu'a des complications decoulant de l'utilisation non supervisee de corticosteroides topiques.

Prevalence and determinants of smoking in three regions of Saudi Arabia

Abstract: OBJECTIVES—To study the prevalence and determinants of cigarette smoking among Saudi nationals in three regions of Saudi Arabia. PARTICIPANTS—A sample of 8310 individuals aged 15 years and above from both sexes, randomly selected from the three regions, using a stratified cluster sampling technique. DESIGN—A cross-sectional, household, community-based survey. Using a predesigned and tested questionnaire, the participants were interviewed by primary care physicians. The interview covered personal, social, and educational characteristics of the respondents, and also included questions about their smoking status, duration of smoking, and daily cigarette consumption. MAIN OUTCOME MEASURES—Association between current smoking and sociodemographic variables, in univariate and multivariate analysis. Degree of interaction between the different determinants of cigarette smoking. RESULTS—The overall prevalence of current smoking was 21.1% for males and 0.9% for females. Most smokers (78%) were young to middle-aged (21-50 years old). Smoking prevalence was higher among married people, among uneducated people, and among those in certain occupations: manual workers, businessmen, army officers, and office workers. CONCLUSIONS—Cigarette smoking is an important public health problem in Saudi Arabia. A more intense and comprehensive tobacco control effort is needed. Keywords: smoking predictors; smoking prevalence; Saudi Arabia

Ureteric Injuries: Diagnosis, Management, and Outcome

Abstract: Objectives: To define the current causes and the optimal methods of early diagnosis and management of ureteric injuries, both iatrogenic (excluding endourologic) and traumatic, and to determine the outcome of these injuries and which identifiable factors affect this outcome. Methods: A retrospective analysis was performed of all the 35 patients who sustained 40 ureteric injuries over a 5-year period (1991-1996). The methods used for diagnosis and management were reviewed. The outcome was assessed in terms of preservation of renal function. Results: The study group was composed of 28 patients with 32 iatrogenic injuries and 7 patients with 8 injuries caused by external trauma. Gynecologic procedures accounted for 63% (20 of 32) of the iatrogenic injuries, whereas motor vehicle crashes accounted for 75% of the external injuries (6 of 8 injuries). The successful diagnostic rate for direct inspection (intraoperatively), intravenous urogram, retrograde pyelogram, and anterograde pyelogram were 33% for the former two and 100% for the latter two. Treatment consisted of primary open repair in 26 cases, a staged procedure in 7 cases, and endoscopic stenting in 5 cases. Of 36 cases with follow-up, complications developed in 9 cases (25%), 7 cases of which were corrected surgically. Overall incidence of nephrectomy was 8%, and the factors that seemed to affect the outcome adversely were pediatric age (≤12 years), injury to upper ureter, delay in recognition, the presence of a urinoma, and/or associated organ injury. Conclusion: Iatrogenic trauma is the leading cause of ureteric injuries. The single controllable factor adversely affecting the outcome of this rather uncommon injury seems to be delayed diagnosis. Wound inspection and intravenous urogram are not reliable for early and accurate diagnosis, and a retrograde pyelogram or an anterograde pyelogram may be needed. Uncontrollable factors adversely affecting the outcome include young age, injury to upper ureter, and associated injuries all seen in association with external trauma rather than iatrogenic injuries.

Toxic and growth retarding effects of three plant extracts on Culex pipiens larvae (Diptera: Culicidae).

Abstract: The toxic and/or development retarding effects on Culex pipiens mosquito larvae by methanol and ether extracts of Azadirachta indica, Rhazya stricta and Syzygium aromaticum were investigated separately. All were found to show biological activity, however, the methanol extracts showed the most profound effects. R. stricta showed marked acute (2 d) and chronic (10 d) toxic effects, having an LC50 and 95% CL of 251(209–326) and 140(110–178); 467(416–699) and 211(198–421) ppm, for the methanol and ether extracts, respectively. Only 3.3% of the larvae pupated and no adults emerged even at the lowest concentration (200 ppm) of methanol extract. Both A. indica extracts were toxic to C. pipiens larvae but at higher concentrations, showing an acute and chronic LC50 and 95% CL of 824(692–980) and 265(111–481); 1620(1380–1892) and 675(514–887) ppm for the methanol and ether extracts, respectively. The methanol extracts of A. indica, at concentrations above 800 ppm, reduced pupation to 3.3% and completely inhibited adult emergence. Both extracts of S. aromaticum were less toxic to the larvae, however their influence on development was remarkable, causing complete inhibition of adult emergence at 200 and 600 ppm concentrations of the methanol and ether extracts, respectively. Future application of these extracts to larval habitats may lead to promising results in mosquito management programmes. Copyright © 1999 John Wiley & Sons, Ltd.

Prevalence and correlates of depression among Saudi elderly.

Abstract: Objectives To assess the prevalence of depression and associated factors in elderly people in Saudi Arabia. Method A cross-sectional national survey of the elderly population of Saudi Arabia was conducted between January 1994 and December 1995. A stratified two-stage sampling technique was used to select the study subjects. In the first stage, a random sample of primary health care centres (PHCs) was selected in each of the five administrative regions of the country. The family health records (FHR) of each selected PHC were reviewed and a list of the elderly (60 years and over) was compiled. In the second stage, a sample of the subjects was selected from the FHR and contacted for a personal interview. The subjects' physical, social and environmental health status were assessed by an interview during which a structured questionnaire was completed. The Geriatric Depression Scale (GDS) was used to screen for depression. Other items of information in the questionnaire included subjects' sociodemographic characteristics, activities of daily living (ADL), laboratory and radiological investigations. Results The total number of elderly subjects included in this study was 7970. Their mean age±standard deviations was 68.8±7.7 (male 69.1±.7.7; and female 67.7±7.5) years. Depressive symptoms were reported in 3110 (39%) of the subjects, and 8.4% were in the severe depressive symptoms score group. Personal characteristics that correlated strongly with depression were poor education (p=0.001), unemployment (p=0.001), divorced or widowed status (p=0.001), old age and being a female (p=0.001). Living in a remote rural area with poor housing arrangements and limited accessibility within the house and poor interior conditions were also significantly associated with high depressive symptoms (p=0.001). Limited privacy, such as having a particular room specified for the elderly, was associated with more depressive symptoms than sharing a room with another person (p=0.001). Lower incomes inadequate for personal needs as well as depending on charity or other relatives were associated with more cases of depression (p=0.001). The proportion of cases of depression correlated positively with the number of medical diagnoses and medications received (p=0.001). Significant depression was associated with loss of a close relative, living alone and limited participation in recreational activities. Perception of poor health and dependence on others for daily activities were associated with more depressive symptoms (p=0.001). Also health problems, especially faecal or urinary incontinence, were associated with more depressive symptoms (p=0.001). Conclusion Depressive symptoms are common among Saudi elderly. Detection and management rates were low. Primary care teams could help these patients if properly trained. A simple instrument such as the Geriatric Depression Scale is useful and easily administered. Copyright © 1999 John Wiley & Sons, Ltd.

Retinol, alpha-tocopherol and carotenoids in diabetes.

Abstract: Objective: A case-control study was conducted to evaluate the effects of diabetes mellitus on serum levels of vitamin A, α-carotene, β-carotene, α-tocopherol, serum and urine RBP. Subjects: One hundred and seven patients with Type 2 diabetes mellitus (28–74 y) were recruited from those attending a primary health care clinic in King Khalid University Hospital in Riyadh City (Saudi Arabia). They were matched for age and sex with 143 healthy individuals. Methods: Fasting blood samples and 10 h urine collections were obtained from all subjects. Levels of vitamins and carotenoids in serum measured by high performance liquid chromatography (HPLC), and of retinol binding protein (RBP) in serum and urine by an enzyme-linked immunosorbent assay (ELISA). Results: The mean serum concentrations of retinol, α-carotene, and α-tocopherol were similar in both groups after correction of lipid soluble vitamins for serum lipids levels. However, serum β-carotene concentration was significantly higher in control subjects than diabetics (P=0.002). Serum and urine RBP concentrations were significantly higher in diabetics than in controls (P=0.0001 ). In normal subjects (but not diabetics) serum concentrations of retinol and RBP were higher in men than in women (P=0.02, P=0.0001 respectively). In both normal and diabetic subjects, serum levels of α-tocopherol (P=0.007) and urine RBP (P=0.005), were higher in men than women. Urinary excretion of RBP was significantly higher in diabetic patients with renal impairment than other diabetics or controls (P=0.0001). There was a negative correlation between fasting blood glucose (FBG) concentration and serum β-carotene (P=0.008) in the total combined group and a positive correlation between FBG and urinary RBP/creatinine (P=0.009) in diabetic patients. Conclusion: Serum β-carotene concentration was significantly lower in diabetic patients than controls. Serum retinol concentration in patients with diabetes was normal, yet serum and urine RBP concentrations were significantly higher in diabetics than in controls. Sponsorship: The research was sponsored by King Faisal Specialist Hospital and Research Center.

Non-Native Speakers' Production of Modified Comprehensible Output and Second Language Learning

Abstract: This study investigated the ability of NNSs to modify their output toward comprehensibility in the contexts of NS-NNS and NNS-NNS interactions and the degree to which such modified comprehensible output (MCO) was other- or self-initiated. Picture-dictation and opinion-exchange tasks were used to collect data from 8 NSs and 24 NNSs of English representing 13 different L1 backgrounds. The 2 tasks were performed in pairs (NS-NNS and NNS-NNS) and were audiotaped. The results showed that most repairs were self-initiated and that NNS-NNS interactions produced more other-initiations and other-initiated MCOs on the picture-dictation task. The frequencies of these MCOs support the importance of modification toward comprehensible output as a process of second language acquisition

Study of the micro-organisms associated with the fermented bread (khamir) produced from sorghum in Gizan region, Saudi Arabia

Abstract: Traditional bread (khamir) was made from sorghum flour of two local varieties, Bayadh and Hamra. The bread was prepared by mixing the sorghum flour with water and spices (onion, garlic, lemon juice and fenugreek) in a 1:0.8 (w/w) ratio and fermented for 24 h at 30 degrees C. Two other fermentations were carried out using an inoculum from the previous fermentation. The micro-organisms were isolated from different plates and identified using different characterization systems. Both total bacterial populations and lactic acid bacteria increased with fermentation time and reached the highest number at 16 h (first fermentation) and at 8 h (second and third fermentation). The content of lactic acid was increased with time to reach 1.2%, but the increase was higher for the second and third fermentations (1.6% each). The pH dropped with time from 6.77 to 4.35 in the first fermentation and from 6.65 to 4.18, and 6.57-3.93, in the second and third fermentations, respectively. The microorganisms, which were isolated and characterized during the 24 h fermentation, included: bacteria (Pediococcus pentosaceus, Lactobacillus brevis, Lact. lactis subsp. lactis, Lact. cellobiosus, Klebsiella oxytoca, Kl. pneumoniae, Enterobacter aerogenes, Ent. sakazakii, Serratia marcescens and Ser. odourifera), moulds (Penicillium sp., Rhizopus sp., Aspergillus niger, Alternaria sp., Fusarium sp. and Mucor sp.) and yeasts (Candida parapsilosis, C. orvegnsis and Rhodotorula glutinis).

Assigning arriving flights at an airport to the available gates

Abstract: Unexpected changes in the flight schedules may disrupt the initial aircraft-gate assignments, and result in congestions and delays in getting aircraft onto gates. A mathematical model is developed to assign the flights with the minimum range of unutilised time periods of gates, subject to the level of service offered to passengers and other physical and managerial considerations. (The assignments are expected to be flexible enough to absorb the minor modifications in the flight schedules.) Interactive optimum and heuristic procedures, both utilising lower bounds on the ranges of future solutions, are proposed to cope with the major changes in disrupting the initial gate-assignments. Over randomly generated schedules, 74 flights can be optimally assigned to seven gates within 17 seconds when the gates are re-utilised within 30 minutes after each departure. The heuristic reaches the optimal solution after evaluating at most 20 partial solutions at one level. Over data obtained from Riyadh’s International Airport, the heuristic outperforms the existing practice: On average, 72.03% and 54.28% improvements are obtained on the number of remote served aircraft and towed aircraft, respectively.

Incidence of four canals in root-canal-treated mandibular first molars in a Saudi Arabian sub-population.

Abstract: Aim The aim of this in-vivo study was to assess the incidence of three roots and four root canals in clinical cases of root-treated mandibular first molars in a Saudi Arabian population. Methodology A clinical study of 251 root-canal treated permanent mandibular first molars was conducted The teeth were examined clinically and radiographically. Results The results showed that 5.97% of the examined teeth had three roots, 57.76% had four root canals (two mesial and two distal) and 42.3% had three root canals (two mesial and one distal). Conclusions The occurrence of four root canals in the mandibular first molar of a Saudi Arabian subpopulation was high.

Diabetes mellitus, hypertension and obesity--common multifactorial disorders in Saudis.

Abstract: Diabetes mellitus, hypertension and obesity are among the multifactorial disorders that occur at a higher prevalence in older age groups. Their prevalence is affected by both genetic and environmental factors. We investigated the distribution of diabetes mellitus, hypertension and obesity in Saudi males and females by conducting a household screening survey during the period 1992-1996 of the adult population (> 14 years) in five different areas of Saudi Arabia. Height, weight, age and other essential details were recorded and diastolic and systolic blood pressures measured. Glucose levels were measured in blood taken after fasting and 2 hours after a glucose load. The data were used to classify the individuals as diabetic, glucose intolerant and normal, using WHO criteria. The individuals were further classified as type 1 diabetes mellitus and type 2 diabetes mellitus. The overall prevalence of diabetes mellitus was 9.7% and 7.0%, obesity 13.05% and 20.26%, overweight 27.23% and 25.20%, and hypertension 5.39% and 3.65% in the adult male and female populations respectively. A significant increase was observed in the prevalence of diabetes, obesity and hypertension with age in both males and females. In addition, the prevalence of obesity and overweight was significantly higher in the individuals with diabetes mellitus.

Steady-state analysis of an isolated self-excited induction generator driven by regulated and unregulated turbine

Abstract: This paper examines the steady-state analysis and performance of an isolated three-phase self-excited induction generator (SEIG) driven by regulated and unregulated turbines. For the case of a regulated turbine, the equivalent circuit is solved with speed as a constant parameter, while for the unregulated turbine, the speed is considered as a variable which depends on the shaft torque according to the turbine characteristics. The no-load speed is considered as a constant independent parameter, which depends on wind speed which is assumed constant in this analysis. The steady-state equivalent circuit is solved using the node-admittance method, and the shaft torque is expressed in terms of the rotor current. The Newton-Raphson method is used to solve the system nonlinear equations. For the present investigation, a linear speed-torque characteristic is considered, but the method of analysis applies equally well to nonlinear characteristics. Experimental investigations on a 1 kW three-phase induction generator driven by a separately excited DC shunt motor have confirmed the accuracy of the proposed method of analysis.

Pharmacological, therapeutic and toxicological properties of furazolidone: some recent research

Abstract: Some of the recent publications on the pharmacological, therapeutic and toxicological properties of the antimicrobial agent furazolidone (FZ) are briefly reviewed. In animals, most of the recently published papers focus on (1) the methodology of measuring the residues of the drug and its metabolites in edible tissues; (2) the carcinogenicity and genotoxicity of FZ; (3) the cellular and molecular basis of FZ-induced cardiomyopthy, and the action of different cardioprotectant drugs thereon; and (4) hormonal effects. In humans, the use of FZ as an anti-ulcer drug and in controlling infectious diseases, especially opportunistic infections in AIDS patients, is described.

Seroepidemiology survey of brucellosis antibodies in Saudi Arabia.

Abstract: BACKGROUND:Brucellosis is considered the most important zoonosis in Saudi Arabia, with a high prevalence among man and livestock. PATIENTS AND METHODS:A natural survey of 23,613 subjects was conduc...

Liquid chromatographic determination of six antiepileptic drugs and two metabolites in microsamples of human plasma.

Abstract: A simple, rapid, sensitive, and reproducible high-performance liquid chromatographic (HPLC) method for simultaneous determination of the antiepileptic drugs (ethosuximide, primidone, lamotrigine, phenobarbital, phenytoin, and carbamazepine) and two metabolites (carbamazepine-diol and carbamazepine-epoxide) in human plasma is described. The procedure involves extraction of the drugs from human plasma (100 microL) with ether using 9-hydroxymethyl-10-carbamyl acridan as an internal standard. The extract was evaporated and reconstituted with mobile phase and then injected onto the chromatograph. The drugs and the internal standard were eluted from a Supelcosil LC-18 stainless steel column at ambient temperature with a mobile phase consisting of a 0.01M phosphate buffer/methanol/acetonitrile (65/18/17, v/v/v) adjusted to a pH of 7.5 with phosphoric acid and a flow rate of 1 mL/min. The effluent was monitored at 220 nm. Quantitation was achieved by using peak area ratio of each drug to the internal standard. The intraassay and interassay coefficients of variation (CV) ranged from 2.43% to 6.25% and from 3.02% to 5.85%, respectively. The absolute (extraction) and relative (analytical) recoveries for the drugs ranged from 70.7% to 104.4% and from 88.3% to 106.1%, respectively. Stability tests showed that the drugs were stable in plasma for at least 4 weeks when stored at -20 degrees C. The method was applied clinically for monitoring the AEDs in epileptic patients.

Ductility of Concrete Beams Reinforced with FRP Bars and Steel Fibers

Abstract: A total of 18 concrete beams were tested to study the influence of adding steel fibers (SF) to concrete mix on the ductility of concrete beams reinforced with fiber reinforced plastics bars (FRP beams). The main variables in the study were the type and volume fraction of the steel fiber. The study also investigated the accuracy of an available model, developed originally to predict the flexural strength of concrete beams reinforced with SF and steel bars (SF-steel beams), after modification in estimating the flexural capacity of the fibrous FRP beams (SF-FRP beams).The results indicate that the ductility of FRP beams is less than 50% of that of the respective steel beams. The results also reveal that the ductility of SF-FRP beams is directly related to the fiber content. In addition, the test results show that inclusion of 1% of hooked SF can improve the ductility of FRP beams to be the same as that of the steel beams. Furthermore, comparison between the predicted and measured flexural capacity of SF-FRP ...

Compliance and control of diabetes in a family practice setting, Saudi Arabia.

Abstract: This study aimed to identify some determinants of compliance with diet, anti-diabetic drugs and the appointment system amongst diabetic patients (n = 294) attending a family practice setting. The results showed that good compliance with diet was significantly higher among males (P = 0.01) and those with good diabetic control (P = 0.01), while good compliance with appointment systems was significantly associated with type II diabetes (P 0.05). When multiple regression analysis was applied, the degree of control of diabetes, its duration and the total score of care were the only predictors of the three aspects of compliance (P < 0.05).

Synthesis of 4-alkyl (aryl)-6-aryl-3-cyano-2(1H)-pyridinones and their 2-imino isosteres as nonsteroidal cardiotonic agents.

Abstract: Thirty new 1,2-dihydropyridine derivatives of the general formula 4-alkyl (aryl)-6-aryl-3-cyano-2(1 H )-pyridinones ( 1–15 ) and 4-alkyl (aryl)-6-aryl-3-cyano-2(1 H )-iminopyridines ( 16–30 ) were synthesized using one-pot multicomponent reactions of the properly substituted acetophenone, appropriate aldehyde, ammonium acetate and ethyl cyanoacetate ( 1–15 ) or malononitrile ( 16–30 ) in ethanol. These target compounds ( 1–30 ) were evaluated for their cardiotonic activity using the spontaneously beating atria model, from reserpine-treated guinea pigs. The best pharmacological profile was obtained with 3-cyano-6-(3,4-dimethoxyphenyl)-4-(4-hydroxyphenyl)-2(1 H )-pyridinone ( 9 ) which displayed selectivity for increasing the force of contraction (108.7±6.7,% change over control) rather than the frequency rate (40.8±5.3,% change over control) at a 5×10 −4 M concentration. The effects of structural changes upon activity are reported.

Agreement between A-mode and B-mode ultrasonography in the measurement of ocular distances.

Abstract: It is generally accepted that A-mode ultrasonography is more accurate than B-mode in measuring intraocular dimensions. Consequently, A-mode ultrasonography is the procedure of choice in ocular biometry while B-mode ultrasonography is used principally for diagnostic purposes. In this study, we investigated the agreement between measurement of intraocular distances using A- and B-mode ultrasonography on freshly enucleated camel eyes. Our results suggest that relative to average A-mode values, B-mode overestimates corneal thickness (bias = 0.06 mm) and anterior chamber depth (bias = 0.03 mm), while it underestimates lens thickness (bias = -0.11 mm), vitreous chamber depth (bias = -0.32 mm) and axial length (bias = -0.40 mm). In general, difference between A- and B-mode values is larger for deeper intraocular dimensions. This implies that the two methods are more likely to give different readings for measurements of lens thickness, vitreous chamber depth and axial length.