Showing papers by "University of Jordan published in 1993"

Hypoglycemic Effects of the Volatile Oil of Nigella sativa Seeds

Abstract: The effects of the volatile oil extracted from Nigella sativa seeds on the levels of glucose and insulin were investigated in the rabbit. The i.p. administration of the volatile oil of N. sativa seeds (50 mg/ kg) to fasting normal and alloxan-diabetic rabbits produced significant hypoglycemic effects. These effects were consistent and time-dependent. In normal animals, 15% and 23% decreases in fasting plasma glucose levels were detected 4 h and 6 h, respectively, after treatment. The same treatment produced 12% and 21% decreases in the fasting glucose levels in diabetic rabbits at the 4 h and the 6 h time intervals, respectively. The administration of the volatile oil was not found to alter basal insulin levels in all animal groups, which might suggest a non-insulin-mediated mechanism of action for the demonstrated hypoglycemic activity. The mode of action of the hypoglycemic effects exhibited by the volatile oil extracted from N. sativa seeds remains to be elucidated.

Least-square identification with error bounds for real-time signal processing and control

Abstract: Set-membership (SM) identification, which refers to a class of algorithms using certain a priori knowledge about a parametric model to constrain the solutions to certain sets, is considered. The focus is on a class of SM-based techniques that are of particular interest in applications requiring real-time processing. The optimal bounding ellipsoid (OBE) algorithms are interpreted as a blending of the classical least-square error minimization approach with knowledge of bounds on model errors arising from SM considerations. Using this interpretation, a general framework embracing all currently used OBE algorithms is developed, and strategies for adaptation and for implementation on parallel machines are discussed. Computational complexity benefits are considered for the various algorithms. The treatment is tutorial, leaving many of the formal details to an appendix that presents an archival theoretical treatment of the key results. A second appendix gives an overview of current research in the general SM identification field. >

Enhanced Heat Transfer, Missing Pin, and Optimization for Cylindrical Pin Fin Arrays

Abstract: We report an experimental investigation on the effects of interfin spacing, shroud clearance, and missing pin on the heat transfer from cylindrical pin fins arranged in staggered and in-line arrays. The interfin spacing in the spanwise direction was so small that the pins were almost touching each other. The optimum interfin spacing in both spanwise and streamwise directions is 2.5 D regardless of both type of array and shroud clearance used.

Norm inequalities for fractional powers of positive operators

Abstract: It is shown that ifA, B andX are operators on a Hilbert space such thatA andB are positive andX belongs to a norm ideal associated with some unitarily invariant norm |‖·|‖, then for 0 ≤r ≤ 1 we have |‖A r XB r |‖ ≤ |‖X|‖1-r|‖AXB|‖ r . This is an extension of the classical Heinz-Kato inequality which was originally proved for the usual operator norm. Other related inequalities are also discussed.

Treatment of childhood brucellosis: results of a prospective trial on 113 children

Abstract: Treatment of childhood brucellosis is controversial and is currently dependent on inclusion of aminoglycoside antibiotics which are both costly and potentially toxic. Hence an alternate mode of therapy preferably dependent exclusively on oral agents is desirable because this decreases medical cost. In this study we prospectively treated 113 children with a combination of two oral agents, trimethoprim-sulfamethoxazole (10 to 12 mg/kg trimethoprim, 50 to 60 mg/kg sulfamethoxazole and rifampin 15 to 20 mg/kg in two divided doses for 6 weeks. The treatment was well-tolerated and all patients responded by defervescence of fever and resolution of all symptoms within 1 to 3 weeks. Relapse after 6 months occurred in four children all of whom responded to repeat therapy by the same agents. We conclude that the combination of trimethoprim-sulfamethoxazole and rifampin is both cost-effective and safe for the treatment of childhood brucellosis.

Cucumber Vein Yellowing Virus; Host Range and Virus Vector Relationships

Abstract: Cucumber vein yellowing virus (CVYV) is transmitted by Bemisia tabaci, it has a narrow host range restricted to some cucurbitaceous plants including Cucumis sativus, C. melo, C. melo var. flexousus, Cucurbita pepo, C. foesti, Citrullus vulgaris, C. colocynthis and Lagenaria siceraria. Although a single whitefly can transmit the disease, the efficiency of transmission was low. At least 15–20 insects per plant were required to cause an infection of 55 % of inoculated plants. The minimum acquisition and inoculation feeding periods were 30 and 15 min, respectively. The latent period in the vector is about 75 min and the whitefly was infectious for not more than 5 h.

A Pan-African alkaline pluton intruding the Saramuj Conglomerate, south-west Jordan

Abstract: The geological setting, petrography and bulk mineral chemistry of a monzodiorite and a presumably consanguineous megaporphyry with large (up to 25 cm) labradorite megacrysts, both intruding the upper Proterozoic Saramuj Conglomerate in south-west Jordan (south eastern shore of the Dead Sea), were examined. The crystallization temperatures of the monzodiorite and the megaporphyry as determined from pyroxene thermometry and supported by contact metamorphic mineralogy are about 700 and 900°C, respectively. The intrusion depth of the monzodiorite is about 3–4 km. The monzodiorite was emplaced in the Saramuj Conglomerate at about 595 + 2 Ma ago according to Rb/Sr and U/Pb age determinations. The stratigraphic positions of the monzodiorite, megaporphyry and their host rock (the Saramuj Conglomerate) were compared with time-equivalent lithologies in the Arabian-Nubian Shield.

Effects of Nigella sativa Seeds on Intestinal Smooth Muscle

Abstract: The spasmolytic effects of an ethanol extract and the volatile oil of Nigella sativa seeds were tested in vitro using isolated segments of rabbit jejunum. The ethanol extract and volatile oil inhibited spontaneous movements of the rabbit jejunum. Also, the volatile oil inhibited contractions of the rabbit jejunum which were induced by high potasium (K+) solution or acetylcholine. This inhibition was dose-dependent, reversible and not affected by the addition of calcium to the organ bath. These data suggest that the plant seed has an antispasmodic effect, possibly due to a calcium antagonistic activity.

Postpartum pain due to thrombosed varicose veins of the round ligament of the uterus.

Abstract: Postpartum thrombosis of varicose veins of the round ligament may present in a clinical picture similar to an irreducible inguinal hernia. Two such unusual cases are reported. One patient underwent surgery while the other, with a presumptive diagnosis of the same condition, was observed, with no complications occurring in both patients. This condition has not to my knowledge been previously reported. The increased incidence of both varicose veins and thrombosis in the postpartum period should alert the physician to the diagnosis of such conditions.

Congenital Fibrosis of the Extraocular Muscles: Report of 24 Cases Illustrating the Clinical Spectrum and Surgical Management

Abstract: The spectrum of congenital fibrosis of the extraocular muscles is wide and includes patients with unilateral or bilateral involvement. We present the ocular findings in 24 patients with the differe...

Electrical properties of laminated epoxy-carbon fiber composite

Abstract: This work deals with the effect of temperature on the electrical properties of laminated epoxy composites containing 60% by volume of commercial unidirectional carbon fibers. The temperature was varied from 30°C to 120°C and the frequency range was from 10 Hz to 10 kHz. It is found that the impedance decreases with increasing temperature and is inversely proportional to the number of layers in the specimen. The calculated dielectric constants show a strong dependence on the frequency below 100 Hz, and attain relatively constant values for frequencies greater than 100 Hz. The decrease in impedance with increasing number of layers was explained in terms of the existence of electrical contacts and bridges both between and within the fibers, in the carbon fiber layers. The activation energy results indicate that there are two conduction mechanisms in this laminated composite.

Isolation and biological effects of 7-O-methyleriodictyol, a flavanone isolated from Artemisia monosperma, on rat isolated smooth muscles.

Abstract: The isolation for the first time from the genus Artemisia (Compositae) of the known flavanone, 7-O-methyleriodictyol (7-methoxy-5,3',4'-trihydroxy-flavanone), its identification, and its biological effects on rat isolated smooth muscles are described 7-O-Methyleriodictyol (10(-7) M to 3 x 10(-4) M) caused concentration-dependent inhibition of the amplitude of the phasic contractions and reduced the tone of the ileum, the uterus, and the urinary bladder It also caused relaxation of the phenylephrine-precontracted pulmonary artery and the acetylcholine-precontracted trachea The flavanone also shifted to the right the acetylcholine concentration-effect curve on the ileum and the oxytocin concentration-effect curve on the uterus The maximum contractions induced by acetylcholine or oxytocin were also inhibited by 7-O-methyleriodictyol These antispasmodic effects are partly consistent with the use of A monosperma in folk medicine for certain gastrointestinal disorders

A comparative fully relativistic/nonrelativistic first-principles Xα-DVM and photoelectron spectroscopic investigation of electronic structure in homologous 4f and 5f tris(η5-cyclopentadienyl)metal(IV) alkoxide complexes

Abstract: The electronic structure of ([eta][sup 5]-C[sub 5]H[sub 5])[sub 3]MOR (M = Ce, Th, U) complexes has been investigated by He I and He II UV photoelectron spectroscopy combined with SCF X[alpha]-DVM calculations. Fully relativistic Dirac-Slater calculations were also carried out for the M = Th complex. The nonrelativistic calculations indicate that metal-ligand interactions involving the highest energy ligand orbitals involve primarily metal 5f orbitals while 6d admixtures are found for lower energy orbitals. The M-O bonding is both [sigma] and [pi] in nature and involves primarily metal 6d atomic orbitals. Evidence of a charge redistribution mechanism along the CH[sub 3][yields]O[yields]M[yields]Cp[sub 3] direction provides a satisfactory explanation for the shortened M-O distances and strong propensity for nearly linear M-O-CH[sub 3] linkages observed in diffraction studies. The fully relativistic calculations show that metal d contributions are slightly underestimated at the nonrelativistic level. Such deviations do not, however, alter the overall description of the metal-ligand bonding. The nonrelativistic configuration of the metal center compares well with the relativistic data. Gas-phase ionization energies can be accurately and comparably evaluated at the computationally more efficient nonrelativistic level if optimized basis sets and potential representations are used.

Root growth, development and nutrient uptake of tomato (Lycopersicon esculentum) and Chenopodium album

Abstract: Summary: Resume: Zusammenfassung Growth, development and nutrient uptake of tomato (Lycopersicon esculentum Mill) and fathen (Chenopodium album L.) roots were investigated under glasshouse and natural conditions. There were no significant differences between the two species in total root dry weight up to 3 weeks after emergence, although C. album had a lower proportion of root dry weight in the top soil layers (0–10, 10–20 cm) and higher proportions at greater depths (20–30, 30–40 cm) for the first 2 weeks. Under natural conditions, C. album had a greater root dry weight than tomato in the top soil layer (0–10 cm) and at depths between 40 and 70 cm. Root dry weight of C. album was not greatly changed but that of tomato decreased with depth in soil layers between 10 and 60 cm. C. album had lower concentrations of N and Ca in the roots than tomato at all growth stages, but higher concentrations of P, K and Mg in the shoots. Total K and Mg uptake per unit root mass (root efficiency) was higher for C. album than tomato at all growth stages, while N and P uptake was higher from 5 and 4 weeks, respectively. Croissance, developpement et alimentation racinaires chez la tomate Lycopersicon esculentum et Chenopodium album La croissance, le developpement et l'alimentation racinaires ont eteetudies en serre et en conditions naturelles pour la tomate (Lycopersicon esculentum Mill) et le chenopode blanc (Chenopodium album L.). Il n'y a pas de differences significative entre les 2 especes pour le poids sec racinaire total jusqu'a 3 semaines apres la levee, bien que C. album ait une plus faible proportion de poids sec racinaire dans les couches superficielles de sol (0–10, 10–20 cm) et plus eleves dans les couches plus profondes (20–30, 30–40 cm) pendant les 2 premieres semaines. En conditions naturelles, C. album a un poids racinaire plus eleve que la tomate dans la couche superficielle du sol (0–10 cm) et a des profondeurs entre 40 et 70 cm. Le poids sec racinaire de C. album n'est pas tres variable, celui de la tomate diminue avec la profondeur du sol entre 10 et 60 cm. C. album a des concentrations en N et Ca plus faibles dans les racines que la tomate a tous les stades vegetatifs, mais des concentrations en P, K et Mg plus eleves dans les tiges. Le total de l'absorption de K et Mg par unite de masse racinaire (efficacite racinaire) etait plus eleve chez C. album que dans la tomate a tous les stades, tandis que l'absorption de N et P etait plus elevee a partir de 5 et 4 semaines respectivement. Wurzelwachstum, Entwicklung und Nahrstoffaufnahme von Tomate (Lycopersicon esculentum Mill.) und Chenopodium album L. Das Wurzelwachstum, die Entwicklung und die Nahrstoffaufnahme von Tomate (Lycopersicon esculentum Mill.) und Weisem Gansefus (Chenopodium album L.) wurden im Gewachshaus und unter Freilandbedingungen untersucht. 3 Wochen nach dem Auflaufen gab es zwischen den beiden Arten keine signifikanten Unterschiede der Gesamttrockenmasse, doch hatte Chenopodium album in den ersten 2 Wochen in den oberen Bodenschichten (0…10, 10…20 cm) einen geringeren Anteil der Wurzeltrockenmasse und in groserer Tief (20…30, 30…40 cm) einen hoheren. Unter Feldbedingungen entwickelte Chenopodium album in der obersten Bodenschicht (0…10 cm) und in Tiefen zwischen 40 und 70 cm eine grosere Wurzeltrockenmasse als die Tomate. Die Wurzeltrockenmasse nahm bei der Tomate mit der Bodentiefe zwischen 10 und 60 cm ab, wahrend sie bei Chenopodium album nicht sonderlich verandert war. Chenopodium album hatte in allen Entwicklungsstadien in den Wurzeln geringere N-und Ca-Konzentrationen als die Tomate, aber in den Sprossen hohere P-, K-und Mg-Konzentrationen. Die gesamte K-und Mg-Aufnahme pro Wurzeltrockenmassen-Einheit war bei Chenopodium album in allen Entwicklungsstadien hoher als bei der Tomate, wahrend die N-und P-Aufnahme ab der 5. bzw. 4. Woche groser war.

Electrical Properties of Nickel-Coated Carbon-Fiber/ Nylon 66 Composite:

Abstract: Some electrical properties of a nickel-coated carbon-fiber/nylon 66 com posite with different concentrations are investigated. The impedance behavior, loss factor, and dielectric constant of this composite have been studied at a low-frequency range (3 Hz-10 kHz). The effects of the carbon-fiber content, frequency of the applied electrical field, and temperature on the ac and dc volume electrical conductivities of the given com posite are considered. The calculated dielectric constant of the composite was found to in crease with the filler content. The dependence of the dielectric constant on frequency is attributed to some complicated polarization events. It was found that the measured dc elec trical conductivity is greatly enhanced with the filler content and exhibits temperature de pendence. The determined activation energy of the thermal rate-process of the electrical conduction was found to decrease with the carbon-fiber content

Excitation function of the nuclear reaction 19F(p,αγ)16O in the proton energy range 0.3–3.0 MeV

Abstract: The excitation function for the 19F(p,αγ)16O nuclear reaction in the proton energy range from 0.3 to 3.0 MeV has been measured with a high efficiency BGO scintillation detector. The yield curves measured with ultrathin targets ( ~ 3 nm) reveal many details, especially for those resonances noticed to be having relatively large widths as measured with the thicker “thin” targets (10–50 nm). Thus, new excited states in the 20Ne nucleus that have not been reported in the literature are documented and discrepancies in published data are discussed.

Hereditary thrombophilia among 217 consecutive patients with thromboembolic disease in Jordan.

Abstract: This is a four-year prospective study on patients admitted or referred with thromboembolic disease to Jordan University Hospital or to the Thrombosis/Haemostasis Laboratory at the University of Jordan. The aim of the study was to find the relative prevalence of hereditary thrombophilia. For the purpose of this work, hereditary thrombophilia was diagnosed in the absence of an acquired cause of thrombophilia in addition to two of the following: 1) positive family history of thrombophilia, 2) confirmed same deficiency in a closely related family member, 3) the deficient protein is constantly below 2 SD of the normal mean on repeated testing. All ages were admitted to the study. Acquired systemic factors or local factors known to cause thrombosis or affect the levels of proteins opposing thrombosis were excluded. There were a total of 217 patients (102 males and 115 females) with confirmed throm-boembolic disease. Their mean age was 34 years. A total of 49 patients (26 males and 23 females) fulfilled the criteria of hereditary thrombophilia. There were 17 cases of protein C deficiency (PC), 15 protein S deficiency (PS), 10 antithrombin III deficiency (ATIII), 3 dyfibrinogenemia, 2 heparin cofactor II deficiency, and 2 plasminogen defects. In this group most of the thrombosis was venous. A positive family history was obtained in 65.3% of patients with hereditary thrombophilia. Twenty-seven additional relatives with deficiency were identified upon family studies. The calculated prevalence of hereditary thrombophilia in Jordan is put at 1/25,000. Screening for PC, PS, and ATIII is advocated in young patients who have thromboembolic disease, especially when there is a positive family history of thrombosis. © 1993 Wiley-Liss, Inc.

Polymerized isomers of CuCl2(C8H12N2S2). The X-ray crystal structures of dichloro(5,5′-6,6′-tetrahydro-2,2′-bi-4H-1,3-thiazine-N3, N3′)copper(II) and di-μ-chloro-bis[chloro(5,5′-6,6′-tetrahydro-2, 2′-bi-4H-1,3-thiazine-N3,N3′)copper(II)]

Abstract: The monomer in the title was obtained as a first crop and the dimer as a second crop from a 95% ethanolic solution of CuCl2 and 5,5′-6,6′-tetrahydro-2,2′-bi-4H-1,3-thiazine (2,2′-bi-2-thiazine) in the mole ratio 1∶1.1. The monomeric crystals are blue, dichloro(5,5′-6,6′-tetrahydro-2,2′-bi-4H-1, 3-thiazine- N 3,N 3′)copper(II). The crystal consists of monomeric molecules with no short contacts to neighbouring molecules. The Cu atoms occupy special positions on 2-fold axes. The bidentate 2,2′-bi-2-thiazine bonds via N as it assumes a cis configuration with a twist of 10.3° about the inter-ring C—C bond. The Cu—N distance is 2.013(5) A, and Cu—Cl is 2.231(2) A. Coordination around Cu is slightly distorted square planar with a dihedral angle of 5.8(2)° between the Cu, N, Cl plane and Cu, N′, Cl′ plane. The dimeric crystals are green, di-μ-chloro-bis[chloro(5,5′-6,6′-tetrahydro-2,2′-bi-4H-1, 3-thiazine-N 3,N 3′)copper(II)]. The structure consists of discrete centrosymmetric dimers [CuCl2(C8H12N2S2)]2. Coordination around Cu is distorted square pyramidal (τ = 0.32) with two N atoms from the bidentate 2,2′-bi-2-thiazine occupying adjacent basal sites, and two Cl atoms occupying the other two basal sites. The average Cu—N distance is 2.028(4) A, Cu—Cl(1) is 2.284(2) A, Cu—Cl(2) is 2.239(1) A. Dihedral angle between the CuN2 and CuCl2 planes is 23.7°. Cl(1)′ of the adjacent inversion-related monomer, CuCl2-(C8H12N2S2), occupies the apical position. Cu—Cl(1)′, r = 2.618(2) A. Dimensions in the chloride-bridged planar dimeric moiety, Cu2Cl2, are Cu ⋯ Cu′ 3.449(1) A; Cl(1) ⋯ Cl(1)′ 3.498(2) A; Cu—Cl(1)—Cu′, φ = 89.2(1)°, φ/r = 34.07°/A. The two saturated rings in C8H12N2S2 show a twist of 11.4° about the inter-ring C—C bond.

Use of SVD for power system stabilizer signal selection

Abstract: A detailed model of a single machine infinite busbar system is considered. The stator transients are included, the rotor is represented by four blocks, and the transmission line connecting the machine to the infinite busbar is assumed to be long with series compensation. The model exhibits three types of Hopf bifurcations in different regions in the parameter space. Two approaches based on linear algebra are used for the systematic evaluation of the effectiveness of the supplementary signals used for feedback in the excitation loop to stabilize the system. The first approach is based on using the minimum singular value of a complex matrix as a measure of observability of a mode in a signal. The second approach is based on the determination of the angle between the row vector representing the signal and the nullspace of a complex matrix (A–λI). The right singular vectors are used to find a basis for the nullspace.

Coolant Optimization of a Gas Turbine Engine

Abstract: This paper describes an analysis used to study the performance of the gas turbine engine with particular emphasis on the optimum amount of coolant required for maximum overall efficiency of the engine. The effect of pre-bled air, as well as that drawn from the exit of the compressor, is also studied.The optimum amount of coolant for the engine is found to depend on the effectiveness of the heat extraction parameter A, component efficiencies of the engine and the compressor pressure ratio of the engine.

Intercropping and Poultry Manure Effects on Yields of Corn, Watermelon and Soybean Grown in a Calcareous Soil in the Jordan Valley

Abstract: This study was conducted at the University of Jordan Research Station in the central Jordan Valley during 1988 and 1989 summer growing seasons, to determine the potential and response of summer crops to intercropping system and to poultry manure addition Corn, soybean and watermelon were grown as sole crops and as intercrops in three paired combinations (corn: watermelon, corn: soybean, watermelon: soybean) with three levels of poultry manure (0, 20, 40 t/ha) The crop yields and land equivalent ratios (LERs) were determined for all treatments The highest yields for the two cropping systems were obtained in response to the highest poultry manure addition Corn gave the highest yield when intercropped with soybean, where increases in yield of 45 % and 66 % were obtained over those of corn sole crop at the same level of poultry manure (40 t/ha), in 1988 and 1989 seasons, respectively Soybean gave the highest yield when grown with corn leading to an increase of 35 % and 34 % over soybean sole crop grown at the same level of poultry manure (40 t/ha) in 1988 and 1989, respectively Watermelon gave the highest yield when grown with soybean, giving an increase which ranged from 390 to 920 kg ha−1 over the yield of sole cropping system under the same level of poultry manure (40 t/ha) The LER values for all intercrop treatments were greater than 10 which gave clearly an indication for the superiority of the intercropping over the sole cropping system especially when 40 t ha−1 poultry manure was added Zusammenfassung Mischanbau und Geflugelmist:; Wirkungen auf Ertrage von Mais, Wassermelonen und Sojabohnen im Anbau auf einem kalkhaltigen Boden im Jordan Valley Die Untersuchung wurde an der Universitat von Jordan, Forschungsstation im zentralen Jordan Valley, wahrend der Jahre 1988 und 1989 in der Sommersaison durchgefuhrt, um das Potential und die Reaktionen eines Anbaus von Kulturpflanzen im Sommer auf das Mischanbausystem und zusatzlichen Huhnermist zu untersuchen Es wurden Mais, Sojabohnen und Wassermelonen im Reinanbau und im Mischanbau mit drei Paarungskombintionen (Mais: Wassermelonen, Mais: Sojabohnen, Wassermelonen: Sojabohnen) sowie drei unterschiedlichen Mengen Geflugelmist (0, 20, 40 t/ha) angebaut Die Kulturpflanzenertrage und die land equivalent ratios (LERs) wurden fur alle Varianten bestimmt Die hochsten Ertrage in den beiden Anbausystemen wurden bei der starksten Dungung mit Geflugelmist erzielt Mais gab den hochsten Ertrag in einem Mischanbau mit Sojabohnen, wobei Erhohungen des Ertrages von 45 % und 66 %uber diejenigen des Maisreinanbaus und mit gleicher Menge verwendetem Geflugelmist (40 t/ha) in den Jahren 1988 und 1989 erzielt wurden Sojabohnen gaben den hochsten Ertrag im Mischanbau mit Mais, wobei Zunahmen von 35 % und 34 %uber den Reinanbau von Sojabohnen bei Verwendung von Geflugelmist (40 t/ha) in den Jahren 1988 und 1989 erreicht wurden Wassermelonen gaben den hochsten Ertrag im Mischanbau mit Sojabohnen; die Zunahmen betrugen 390 kg bis 920 kg/ha uber den Ertrag im Reinanbau bei gleicher Geflugelmistmenge (40 t/ha) Die LER-Werte waren bei alien Mischanbausystemen hoher als 1,0; eine deutliche Uberlegenheit des Mischanbaues uber den Reinanbau, insbesondere bei Anwendung von 40 t Geflugelmist/ha, ist danach festzustellen

Hypoglycemic Effects of Prosopis fracta

Abstract: Prosopis fracta (Leguminosae) has been used in Jordanian folk medicine as a hypoglycemic and hypotensive agent. The hypoglycemic activity of an aqueous solution of the lyophylized root extract of Prosopis fracta was tested in normoglycemic and streptozocin-induced hyperglycemic rats. Results indicate that the root extract caused significant reductions in blood glucose concentration when given orally.

Thyroid Function in Children with β-Thalassemia Major in North Jordan

Abstract: Basal thyroid function was assessed by serum thyroxine, tri-iodothyronine and thyroid-stimulating hormone levels in 90 patients 2-10 years old with beta-thalassaemia major. Based on measured serum ferritin levels, patients were classified into two groups: group (I) which included 63 patients with ferritin concentrations ranging from 300 to 7000 ng/ml (mild iron overload) and group (II) which included 27 patients with ferritin concentrations higher than 7000 ng/ml (severe iron overload). The results of thyroid function in both groups were compared with those of 50 control subjects. In group (I), the mean concentrations of all measured hormones were not significantly different from those of the controls. In group (II), the mean concentrations of thyroxine and tri-iodothyronine decreased by 29 and 35 per cent (P < 0.05), respectively, and the mean concentration of thyroid-stimulating hormone showed a 2.6-fold increase (P < 0.01) in comparison with those of the controls. The data clearly demonstrate the occurrence of impaired thyroid function and its possible association with iron overload in a considerable proportion of transfusion-dependent beta-thalassaemic patients.