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Biomedical subjects

M A Abdullah

Publications and source records attributed to M A Abdullah.

At least 19 recordsLinked to original sources
PubMed2004

Anthraquinones production, hydrogen peroxide level and antioxidant vitamins in Morinda elliptica cell suspension cultures from intermediary and production medium strategies.

The effects of medium strategies [maintenance (M), intermediary (G), and production (P) medium] on cell growth, anthraquinone (AQ) production, hydrogen peroxide (H2O2) level, lipid peroxidation, and antioxidant vitamins in Morinda elliptica cell suspension cultures were investigated. These were compared with third-stage leaf and 1-month-old callus culture. With P medium strategy, cell growth at 49 g l(-1), intracellular AQ content at 42 mg g(-1) DW, and H2O2 level at 9 micromol g(-1) FW medium were the highest as compared to the others. However, the extent of lipid peroxidation at 40.4 nmol g(-1) FW and total carotenoids at 13.3 mg g(-1) FW for cultures in P medium were comparable to that in the leaf, which had registered sevenfold lower AQ and 2.2-fold lower H2O2 levels. Vitamin C content at 30-120 microg g(-1) FW in all culture systems was almost half the leaf content. On the other hand, vitamin E content was around 400-500 microg g(-1) FW in 7-day-old cultures from all medium strategies and reduced to 50-150 microg g(-1) FW on day 14 and 21; as compared to 60 microg g(-1) FW in callus and 200 microg g(-1) FW in the leaf. This study suggests that medium strategies and cell growth phase in cell culture could influence the competition between primary and secondary metabolism, oxidative stresses and antioxidative measures. When compared with the leaf metabolism, these activities are dynamic depending on the types and availability of antioxidants.

Anthraquinones↗
PubMed2003

The effect of custom tray material type and fabrication technique on tensile bond strength of impression material adhesive systems.

The purpose of this investigation was to evaluate the tensile bond strengths of two impression material systems (polysulphide and polyvinyl siloxane) to two custom tray materials [autopolymerizing and visible light-cured (VLC) acrylic resin]. The effect of polymerizing the tray materials directly against wax spacer and tin foil was evaluated for each material. Polymerizing tray materials against tin foil significantly increased the bond strengths of polysulphide and polyvinyl siloxane impression materials to VLC and autopolymerizing acrylic resin tray materials. Polyvinyl siloxane VLC cured against tin foil combination produced the strongest bond. The VLC resin tray material generated greater bond strength than autopolymerizing acrylic resin when polymerized against tin foil.

Acrylic Resins↗
PubMed2000

Growth and anthraquinone production of Morinda elliptica cell suspension cultures in a stirred-tank bioreactor.

The effects of medium strategy, number of impellers, aeration mode, and mode of operation on Morinda elliptica cell suspension cultures in a stirred-tank bioreactor are described. A lower number of impellers and continuous aeration contributed toward high cell growth rate, whereas a higher number of impellers reduced cell growth rate, although not anthraquinone yield. The semicontinuous mode could indirectly imitate the larger scale version of production medium strategy and improved anthraquinone production even with 0. 012% (v/v) antifoam addition. Production medium promoted both growth (maximum dry cell weight of 24.6 g/L) and anthraquinone formation (maximum content of 19.5 mg/g of dry cell weight), without any necessity for antifoam addition. Cultures in production medium or with higher growth rate and anthraquinone production were less acidic than cultures in growth medium or with lower growth rate and anthraquinone production. Using the best operating variables, growth of M. elliptica cells (24.6 g/L) and anthraquinone yield (0.25 g/L) were 45% and 140%, respectively, lower than those using a shake flask culture after 12 days of cultivation.

Anthraquinones↗
PubMed2000

Pulmonary haemosiderosis in Saudi children: report of two cases and review of the literature.

Two children with idiopathic pulmonary haemosiderosis are reported. These are the first cases of this disease from Saudi Arabia and highlight the diagnostic problem caused by their presentation as cases of iron deficiency anaemia. The aetiopathogenesis, clinical presentation, diagnosis and management are discussed. The attention of paediatricians is drawn to this relatively rare cause of iron deficiency anaemia.

Anemia↗
PubMed2000

Adolescent endocrinology in Saudi Arabia.

OBJECTIVE: The importance of providing special health care services for adolescents has been recently stressed. In Saudi Arabia, adolescents have no special services. In this study, we describe our first 5 years experience of an adolescent endocrinology clinic in Security Forces Hospital. We believe it is the first clinic with this objective in the Kingdom. METHODS: An adolescent endocrinology clinic was run by a team composed of pediatric endocrinologist, diabetic nurse educator, clinic nurse and a dietician in collaboration with other supportive staff and consultants from other disciplines. The methodology of setting up, staffing and running the clinic is described. RESULTS: About 223 cases were registered over 5 years. The most common problems were short stature 53 (24%), diabetes mellitus 49 (22%), obesity 40 (18%), thyroid disorders 28 (13%), delayed puberty 20 (9%) and rickets (8%). The clinic was well accepted by parents and their families. We learned a lot on how to handle these problems locally. CONCLUSION: Based on our experience, we recommend establishing special health care services for adolescents both at the primary care, as well as secondary and tertiary care levels.

Adolescent↗
PubMed2000

Arthrogryposis, renal dysfunction and cholestasis syndrome.

We report for the first time from the Arabian Gulf area 3 patients with arthrogryposis multiplex congenita, cholestasis and renal tubular dysfunction from a Saudi family with 2 other siblings and 3 cousins who possibly died with a similar clinical picture. We also document for the second time in literature other findings in this syndrome including cerebral abnormalities (hypoplastic corpus callosum), congenital heart disease and nerve deafness. We suggest that some of these cases might benefit from ursodeoxycholic acid therapy. We believe that this autosomal recessive disorder is possibly under-diagnosed in this region with a high consanguineous marriage rate.

Abnormalities, Multiple↗
PubMed1999

Case of partial trisomy 2q3 with clinical manifestations of Marshall-Smith syndrome.

We describe a girl with physical anomalies, accelerated skeletal maturation, failure to thrive, and respiratory difficulties consistent with a diagnosis of Marshall-Smith syndrome (MSS). Chromosome analysis showed an inverted duplication of chromosome 2 [46,XX,inv dup(2)(q37q32) de novo] identified by G banding and confirmed by FISH. Several cases of trisomy 2q3 have been reported and established a syndrome, but the present case is the first to be associated with accelerated skeletal maturation and a clinical picture resembling MSS. This raises the possibility that the cause of MSS involves the q3 region of chromosome 2. Few reports of MSS include study of the karyotype, although the chromosomes were apparently normal in those cases where they have been examined. We suggest that karyotyping be undertaken with particular attention to the 2q3 region in patients with suspected MSS. It also would be prudent to assess bone age in all children with trisomy 2q.

Abnormalities, Multiple↗
PubMed1998

Effect of frequency and amplitude of vibration on void formation in dies poured from polyvinyl siloxane impressions.

STATEMENT OF PROBLEM: Numerous factors are involved in making a void-free dental stone cast from a polyvinyl siloxane impression. PURPOSE: The aim of this study was to determine whether frequency and amplitude of vibration had any effect on the formation of voids on the cast surface poured from polyvinyl siloxane impression with a mechanical model vibrator. MATERIAL AND METHODS: Impressions were poured in dental stone with a mechanical model vibrator that was set at vibration frequency 3000 cycles/min (low) and 6000 cycles/min (high) by a knob. The amplitude of vibration is provided in 5 steps and remained constant for the step set on the instrument. A total of 240 casts were prepared. The vibrator was set at low frequency and 30 impressions were poured for each of the 5 steps of amplitude. The vibrator was then set at high frequency and 30 impressions were poured for each of the 5 steps of amplitude. The resultant casts were examined for the presence of surface voids under 10 x magnification. RESULTS: Means for voids in all cast groups calculated for low and high vibration frequencies indicated that an increase in the amplitude of vibration caused an increase in the number of voids on the die surface. CONCLUSION: Use of high frequency of vibration 6000 cycles/min and 0.40 mm amplitude produced significantly fewer voids (P < .0001) compared with steps 4 (0.45 mm) and 5 (0.80 mm) amplitude.

Analysis of Variance↗
PubMed1997

Childhood goitre in Saudi Arabia.

Thirty-two Saudi children (aged 1.5-14 years) with goitre were seen over a 6.5-year period in a paediatric endocrinology clinic. There was a female to male ratio of 1.9:1. Of these, 27 (84.3%) had diffuse thyroid enlargement and five (15.7%) nodular goitre. The commonest causes were dyshormonogenesis (37.5%) followed by Hashimoto's thyroiditis (34.4%). Three boys and one girl had Graves' disease. There were three (9.4%) with simple goitre and one case each of iodine deficiency goitre and tuberculous thyroiditis. Further study of the prevalence and causes of goitre, including iodine deficiency goitre, in Saudi Arabia is suggested.

Adolescent↗
PubMed1996

A cross-sectional study of canine dimorphism in establishing sex identity: comparison of two statistical methods.

The occurrence of canine tooth dimorphism in Indian subjects has been investigated and the use of two statistical methods of evaluation compared. These were the methods of N.G. Rao and co-workers published in 1988 and quadratic discriminant analysis for correct classification of sex. Parameters considered were (i) the mesiodistal width of maxillary and mandibular canines, (ii) the maxillary canine arch width (intercanine distance) and (iii) the mandibular canine arch width. The results indicated significant dimorphism of the maxillary and mandibular canine teeth. When the results of the arch widths were subjected to the two statistical methods, differing results were obtained in the accuracy of sex classification. The percentage of correct classifications of sex was higher when using quadratic discriminant analysis.

Adolescent↗
PubMed1996

Tuberculous anterior neck mass simulating goitre.

A 13-year-old Saudi boy was referred to the paediatric endocrinology clinic for evaluation of rapidly progressive goitre with weight loss of 6 months duration. A clinical diagnosis of possible thyroid malignancy was made. On exploration the mass was found to be tuberculous in origin, attached to the thyroid gland, and responded to partial excision and anti-tuberculous chemotherapy. Tuberculosis should be considered in the differential diagnosis of anterior midline neck masses.

Adolescent↗
PubMed1995

Study of the acceptability of lateral interocclusal records by a modular articulator.

Semiadjustable articulators are extensively used for routine restorative procedures. The instruments may be adjusted by lateral interocclusal records. However, it has been reported that semiadjustable articulators do not accept lateral interocclusal records from all patients. The Hanau modular system 194 semiadjustable articulator was introduced to develop occlusion with minimal error. The manufacturer recommends that the instrument should be adjusted by means of lateral interocclusal records. This study investigated the acceptability of lateral interocclusal records. Sixty lateral interocclusal records were made for 30 edentulous subjects, and the acceptability of the records was evaluated by use of the split-cast mounting procedure. Out of 60 lateral interocclusal records, 52 (87%) records were accepted by the articulator. A Z test was used for two proportions and was statistically significant (p < 0.05).

Adult↗
PubMed1995

Ambiguous genitalia: comparative role of pelvic ultrasonography and genitography.

Ambiguous genitalia represents a true medical and social emergency which needs a multi-disciplinary team approach for elucidation. The paediatric radiologist plays an important role in defining the genital anatomy which remains one of the most important factors in sex determination. Aiming to compare the predictive value of pelvic ultrasonography and genitography in sex determination in patients with ambiguous genitalia, we retrospectively reviewed the medical records of 69 patients, 53 females and 16 males, where both procedures were employed. In female pseudohermaphroditism, the presence of a uterus with or without vagina was predicted in 46 (86.8%) patients by ultrasound compared with 44 (83%) patients in whom a genitogram revealed a vagina +/- uterus. In six (11.3%) patients, a genitogram revealed a male-type urethra. The combination of ultrasound and genitogram, however, was more sensitive and predicted the presence of a uterus with or without vagina in 52 (98.1%) patients. In male pseudo-hermaphroditism, there was no false positive by ultrasound, and a genitogram revealed a male-type urethra in 12 (75%) patients. In conclusion, although real time pelvic ultrasonography is less invasive than genitography, its yield in elucidating genital anatomy is comparable. The combination of both procedures is more informative and has a better yield.

Child↗
PubMed1995

Gangrene of the penis.

A case of gangrene of the penis, rarely seen at our University Hospital is reported. Urolithiasis, urinary tract infection, infected piles and anaemia were found to be associated with the condition. Because of rapid spread of the gangrene, partial amputation was required in this reported case.

Aged↗
PubMed1995

Distribution and ecology of the mosquito fauna in the southwestern Saudi Arabia.

A mosquito Larval survey was carried out in the Southwestern region of Saudi Arabia for a two subsequent years period. Nine mosquito species were identified; 4 Anopheline species; Anopheles arabiensis, An. sergentii, An. multicolor and An. tenebrosus and 3 Culicine species, Culex pipiens, Cx. quinquefaciatus and Cx. theileri as well as one Aedine species, Aedes caspius and Culiseta subochrea. A map was made showing the distribution of the encountered species and a full description of all breeding places was made also. The association of different species in each breeding site was also recorded.

Aedes↗
PubMed1994

The in vitro metabolism of 17-hydroxyprogesterone by ovaries of the goldfish, Carassius auratus, is affected by substrate concentration.

Ovaries of mature goldfish (Carassius auratus) were incubated with 17-[3H]hydroxyprogesterone and 0, 0.01, 0.1, 1, 10, and 100 micrograms/ml 17-hydroxyprogesterone (17P). The major products were quantified after separation by thin-layer and high-performance chromatography. The results show that substrate concentration markedly affects the pattern of metabolites. Glucuronides and sulfates decreased from 7.2 +/- 2.0 and 28.5 +/- 4.4% of recovered radioactivity, respectively, in the absence of added 17P to insignificant yields at 10 micrograms/ml 17P. 7 alpha-Tetrols were the major products (36-52%) with 0-1 microgram/ml substrate, but at 10 and 100 micrograms/ml 17,20 alpha-dihydroxy-4-pregnen-3-one (17,20 alpha P) was the major metabolite and there were low yields of other products. 11-Deoxycortisol was produced in significant amounts only at low substrate concentrations. The results support the hypothesis that 5 alpha-reduced-7 alpha-hydroxylated metabolites are formed by enzymes of high activity but low capacity and serve to limit secretion of 17,20 alpha P and its 20 beta epimer to the period of maximum GtH stimulation.

17-alpha-Hydroxyprogesterone↗
PubMed1994

Increased substrate concentration causes a shift from production of 11-oxygenated androgens to 17,20-dihydroxyprogestogens during the in vitro metabolism of 17-hydroxyprogesterone by goldfish testes.

Goldfish testes were incubated with [3H]17-hydroxyprogesterone in the presence of 0 to 100 micrograms/ml of unlabeled substrate and metabolites examined by thin-layer and high performance liquid chromatography. Conjugated steroids, predominantly sulfates, accounted for 50% of recovered activity with radiolabeled substrate alone, but percentage yields decreased to very low levels with substrate concentrations of 1 micrograms/ml and above. The 11-oxygenated androgens, androstenetrione and 11-ketotestosterone, were the major products with 0 to 0.1 micrograms/ml substrate, but at concentrations of 1 to 100 micrograms/ml the major products were 17,20 alpha-dihydroxy-4-pregnen-3-one (30% of recovered activity) with smaller amounts of the 20 beta-epimer. 11-Deoxycortisol was a minor product at all substrate concentrations. Production of 11-oxygenated androgens in the medium reached a maximum value of 40 ng/100 mg tissue/3 hr with 2 micrograms substrate, but progestogen production continued to increase up to the maximum substrate used (30 micrograms at 200 micrograms substrate). The results demonstrate a clear switch from production of 11-oxygenated androgens to that of 20-reduced progestogens with increased substrate concentration. This switch shows similarities to that observed for in vivo plasma steroid concentrations during the prespawning period of many male teleosts and it is suggested that this, at least in part, may be due to increased substrate availability resulting from elevated gonadotropin secretion.

17-Hydroxysteroid Dehydrogenases↗