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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Sex reassignment: A challenging problem - current medical and islamic guidelines

Sexual ambiguity is a complex and often confusing medical problem. In addition to the life-threatening adrenal crises which may accompany some forms, ambiguity of the genitalia may lead to incorrect sex assignment by parents and/or health personnel. Children who present to medical attention beyond the neonatal period constitute a challenging problem due to the grave consequences of this condition. Thirty cases in whom sex reassignment was indicated were seen at King Khalid University Hospital, Riyadh, over a 10-year period. Of these, 27 (90%) were genetic females (20 were 21- and seven were 11-hydroxylase deficient) and three (10%) were genetic males (two partial androgen insensitive and one 5alpha-reductase deficient). All genetic males who were incorrectly assigned as females accepted reassignment. But 9 out of 27 (33%) of the genetic females who were incorrectly assigned as males refused reassignment. Preference for male sex assignment, delayed diagnosis and sociocultural circumstances seem to be the contributing factors for refusal. A national consensus about this important issue strengthened by the existing religious recommendations in demanded.

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.

Non-fatal strangulation: an uncommon parachute-related accident

A case of non-fatal strangulation of the neck by rigging lines of a parachute during military training is presented. It is an unusual but potentially life-threatening injury. Probable factors leading to such injury are discussed.

Congenital adrenal hypoplasia: A disorder frequently missed

Congenital adrenal hypoplasia is a rare disease which is known to cause severe salt wasting in the neonatal period. In this report, we describe three patients from two different families who were seen at King Khalid University Hospital, Riyadh, Saudi Arabia. All patients presented with classical clinical, biochemical, hormonal and radiological findings of congenital adrenal hypoplasia. To the best of our knowledge, no similar cases were reported from this part of the world.

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).

Congenital adrenal hyperplasia in a referral hospital in Saudi Arabia: Epidemiology, pattern and clinical presentation

Eighty-two children (30 males and 52 females) with congenital adrenal hyperplasia (CAH) were seen at King Khalid University Hospital (KKUH) over a 10-year period. Of these, 74 (90.2%) were Saudis and eight (9.8%) non-Saudis. Fifty-nine (72%) patients were 21-hydroxylase deficient. Of these, 56 (95%) had variable degrees of salt depletion. Nineteen (23.2%) patients had a deficiency of 11-ss-hydroxylase enzyme and four (4.8%) showed deficiency of 3-ss-hydroxysteroid dehydrogenase. The consanguinity rate was high (71.2%) and positive family history was documented in 45.8%. Thirty-nine infants deaths occurred within 25 families. The diagnosis was often delayed. Of the 52 females, 27 (52%) were initially assigned male sex. These results indicate the importance of physicians' awareness and the need for a neonatal screening program for early detection and appropriate management.

Effect of gender, birth weight and gestational age on serum 17-hydroxyprogesterone concentration and distribution among neonates in Saudi Arabia

Blood samples from 813 newborns were spotted on to filter paper and the 17-hydroxyprogesterone concentration was measured using the Delfia (R) fluorometric immunoassay. The median, mean, and standard deviation (SD) for the total population were 20, 21 and (11) nmol/L respectively. Males had significantly higher levels than females with median, mean and (SD) of 22, 22 and (12) nmol/L. Similarly, low birth weight babies were found to have significantly higher levels than normal birth weight babies with median, mean and (SD) of 21, 24 (12) nmol/L. Preterm babies were also found to have significantly higher levels than full term babies, with median, mean and (SD) of 25, 29 (16) nmol/L. As experienced elsewhere, those factors should be taken into consideration when considering a cut-off point in any neonatal screening program for congenital adrenal hyperplasia.

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.

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.

Substrate concentration affects the in vitro metabolism of 17-hydroxyprogesterone by ovaries of the carp, Cyprinus carpio

Carp ovarian tissue was incubated with (3)H-17-hydroxyprogesterone in the presence of 0, 0.1, 1, 10, and 100 μg ml(-1) unlabeled 17-hydroxyprogesterone. The pattern of metabolites formed showed a marked variation with substrate concentration. Formation of glucuronide and sulphate conjugates was important only at low substrate concentration. At high substrate concentration (10 and 100 μg ml(-1)) 17,20α-dihydroxy-4-pregnen-3-one was the major metabolite, but at intermediate concentrations polar 7α-hydroxypregnanetetrols predominated. The results support the hypothesis that at low substrate concentrations conjugating, 5α-reducing and 7α-hydroxylating enzymes, of high activity but low capacity, act as scavengers to deactivate any steroids formed during the relatively low pituitary gonadotrophin secretions which are necessary for oocyte development, but that during the prespawning gonadotrophin surge when high levels of substrate are present these enzymes are saturated and 17,20α-dihydroxy-4-pregnen-3-one (17,20αP) becomes the major ovarian steroid. The possible role of 17,20αP during oocyte final maturation requires further examination.

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.

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.

Antithyroid antibodies and thyroid dysfunction in Saudi children with Down syndrome

Fifty children (ages seven months to nine years) with Down syndrome compared with age and sex matched controls were tested for antithyroid antibodies. Seven (14%) of the Down group were found to b seropositive; six (12%) for antimicrosomal antibodies; three for both antimicrosomal and antithyroglobulin; none was positive for antithyroglobulin alone. All the control group were seronegative and had no clinical evidence of thyroid disease. Three (6%) of the Down group had hypothyroidism, two due to autoimmune thyroiditis and one had disease. Thyroid dysfunction was not previously suspected in the two symptomatic children. In view of our findings, recommendations are made to regularly screen these children for autoantibdies and evidence of thyroid dysfuntion.

Predation of Acacia seeds by bruchid beetles and its relation to altitudinal gradient in south-western Saudi Arabia

The distribution of the Acacia trees and their bruchid seed beetles in south-western Saudi Arabia revealed that each of the host-insect pair occupied a specific range along the altitudinal gradient from sea level to 2500 m. At low to intermediate altitudes, between sea level and 1750 m, at hot to worm environments, the following host-insect pairs were recorded: Acacia asak--Bruchidius. sp., A. ehrenbergiana--B.saudicus, A.hamulosa--B.sp., A.oerfota--B.sp., A.seyal--B. sp., A.tortilis--B. aurivilli and A.tortilis--B. sahelicus. At high altitudes between 1750 and 2500m, at cool environment the following host insect pairs were recorded: A.negrii--B.arabicus and A.gerrardii--B.arabicus. The rate of seed predation varied among Acacia spp., but the highest were recorded in A. tortilis and A. ehrenbergiana.

Effect of different polymerization techniques on dimensional stability of record bases

In this study, discrepancies in the adaptation of the posterior borders of maxillary record bases to their casts were analyzed with five polymerization techniques: (1) bench curing, (2) curing under a coat of petroleum jelly, (3) curing in a monomer atmosphere, (4) curing under air pressure, and (5) curing under warm water and air pressure. Ten record bases were made with each of the five techniques and were tested immediately for dimensional accuracy. Measurements of adaptations were made at three points that represent the right and left crest of the ridge and midpalatal region with a measuring microscope equipped with a filar unit-measuring eyepiece. Dimensional changes were observed under all test conditions. The monomer atmosphere technique produced the least dimensional change when compared with other techniques.