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Biomedical subjects

A Azzam

Publications and source records attributed to A Azzam.

14 recordsLinked to original sources

Excitation functions of (p,x) reactions on natural nickel between proton energies of 2.7 and 27.5 MeV.

Excitation functions have been measured for a number of proton induced nuclear reactions on natural nickel in the energy range from 27.5 MeV down to their threshold energy, using the activation method on stacked foils. Excitation functions for the reactions leading to the formation of (60)Cu, (61)Cu, (56)Ni, (57)Ni, (55)Co, (56)Co, (57)Co and (58)Co are presented and compared with earlier reported experimental data. Comparison with the recommended data reported by the International Atomic Energy Agency [Gul et al., 2001. Charged particle cross section database for medical radioisotope production. IAEA-TECDOC-1211, IAEA Vienna, Austria] is also presented when possible.

Computer Simulation↗

Psychiatric and neuropsychological characterization of Pallister-Hall syndrome.

Pallister-Hall syndrome (PHS) is a rare, single-gene, malformation syndrome that includes central polydactyly, hypothalamic hamartoma, bifid epiglottis, endocrine dysfunction, and other anomalies. The syndrome has variable clinical manifestations and is inherited in an autosomal dominant pattern. We sought to determine whether psychiatric disorders and/or neuropsychological impairment were characteristic of PHS. We prospectively conducted systematic neuropsychiatric evaluations with 19 PHS subjects ranging in age from 7 to 75 years. The evaluation included detailed clinical interviews, clinician-rated and self-report instruments, and a battery of neuropsychological tests. Seven of 14 adult PHS subjects met diagnostic criteria for at least one DSM-IV Axis I disorder. Three additional subjects demonstrated developmental delays and/or neuropsychological deficits on formal neuropsychological testing. However, we found no characteristic psychiatric phenotype associated with PHS, and the frequency of each of the diagnoses observed in these subjects was not different from that expected in this size sample. The overall frequency of psychiatric findings among all patients with PHS cannot be compared to point prevalence estimates of psychiatric disease in the general population because of biased ascertainment. This limitation is inherent to the study of behavioral phenotypes in rare disorders. The general issue of psychiatric evaluation of rare genetic syndromes is discussed in light of this negative result.

Abnormalities, Multiple↗

Experimental studies and nuclear model calculations on proton-induced reactions on (nat)Se, (76)Se and (77)Se with particular reference to the production of the medically interesting radionuclides (76)Br and (77)Br.

Excitation functions of the reactions (nat)Se(p,x)(75,76,77,82)Br, (76)Se(p,xn)(75,76)Br, (76)Se(p,x)(75)Se and (77)Se(p,xn)(76,77)Br were measured from their respective thresholds up to 40 MeV, with particular emphasis on data for the production of the medically important radionuclides (76)Br and (77)Br. The conventional stacked-foil technique was used. The samples were prepared by a sedimentation process. Irradiations were performed using the compact cyclotron CV 28 and the injector of COSY, both at the Research Centre Jülich. In order to validate the data, nuclear model calculations were performed using the code ALICE-IPPE which is based on the preequilibrium-evaporation model. Good agreement was found between the experimental and theoretical data, except in the high-energy region where the calculated data were somewhat higher. All the measured excitation curves were compared with the data available in the literature. From the experimental data the theoretical yields of all the investigated radionuclides were calculated and plotted as a function of proton energy. The calculated yield of (77)Br from the (nat)Se(p,x)(77)Br process over the energy range E(p)=25-->15 is 72.7 MBq/microAh and from the (77)Se(p,n)(77)Br reaction over E(p)=15-->6 MeV it is 86.2 MBq/microAh. The yield of (76)Br from the (76)Se(p,n)(76)Br reaction for E(p)=15-->8 is 360.1 MBq/microAh and from the (77)Se(p,2n)(76)Br reaction for E(p)=28-->18 MeV it is 879.2 MBq/microAh. The radionuclidic impurity levels are discussed.

Bromine Radioisotopes↗

Changes in phosphatidylcholine fatty acid composition are associated with altered skeletal muscle insulin responsiveness in normal man.

The fatty acid composition of skeletal muscle cell membrane phospholipids (PLs) is known to influence insulin responsiveness in man. We have recently shown that the fatty acid composition of phosphatidylcholine (PC), and not phosphatidylethanolamine (PE), from skeletal muscle membranes is of particular importance in this relationship. Efforts to alter the PL fatty acid composition in animal models have demonstrated induction of insulin resistance. However, it has been more difficult to determine if changes in insulin sensitivity are associated with changes in the skeletal muscle membrane fatty acid composition of PL in man. Using nicotinic acid (NA), an agent known to induce insulin resistance in man, 9 normal subjects were studied before and after treatment for 1 month. Skeletal muscle membrane fatty acid composition of PC and PE from biopsies of vastus lateralis was correlated with insulin responsiveness using a 3-step hyperinsulinemic-euglycemic clamp. Treatment with NA was associated with a 25% increase in the half-maximal insulin concentration ([ED50] 52.0 +/- 7.5 to 64.6 +/- 9.0 microU/mL, P < .05), consistent with decreased peripheral insulin sensitivity. Significant changes in the fatty acid composition of PC, but not PE, were also observed after NA administration. An increase in the percentage of 16:0 (21% +/- 0.3% to 21.7% +/- 0.4%, P < .05) and decreases in 18:0 (6.2% +/- 0.5% to 5.1% +/- 0.4%, P = .01), long-chain n-3 fatty acids (1.7% +/- 0.2% to 1.4% +/- 0.1%, P < .01), and total polyunsaturated fatty acids ([PUFAs] 8.7% +/- 0.8% to 8.0% +/- 0.8%, P < .05) are consistent with a decrease in fatty acid length and unsaturation in PC following NA administration. The change in ED50 was significantly correlated with the change in PUFAs (r = -.65, P < .05). These studies suggest that the induction of insulin resistance with NA is associated with changes in the fatty acid composition of PC in man.

Adult↗

Skeletal muscle phosphatidylcholine fatty acids and insulin sensitivity in normal humans.

The fatty acid composition of skeletal muscle membrane phospholipids (PL) is known to influence insulin responsiveness in humans. However, the contribution of the major PL of the outer (phosphatidylcholine, PC) and inner (phosphatidylethanolamine, PE) layers of the sarcolemma to insulin sensitivity is not known. Fatty acid composition of PC and PE from biopsies of vastus lateralis from 27 normal men and women were correlated with insulin sensitivity determined by the hyperinsulinemic euglycemic clamp technique at insulin infusion rates of 0.4, 1.0, and 10.0 mU . kg-1 . min-1. Significant variation in the half-maximal insulin concentration (ED50) was observed in the normal volunteers (range 24.0-146.0 microU/ml), which correlated directly with fasting plasma insulin (r = 0.75, P < 0.0001). ED50 was inversely correlated with the degree of membrane unsaturation (C20-C22 polyunsaturated fatty acids; r = 0. 58, P < 0.01) and directly correlated with fatty acid elongation (ratio of 16:0 to 18:0, r = 0.45, P < 0.05) in PC. However, no relationship between fatty acid composition and insulin sensitivity was observed in PE (NS). These studies suggest that the fatty acid composition of PC may be of particular importance in the relationship between fatty acids and insulin sensitivity in normal humans.

Adult↗

Hepatitis C antibodies in haemodialysis and pattern of end-stage renal failure in Gassim, Saudi Arabia.

As by the end of 1992, 96 (47 females; 49 females) patients were on regular dialysis treatment for end stage renal failure (ESRF) in 5 haemodialysis HD units, the Gassim region of Saudi Arabia. Because of lack of facilities, paediatric patients were under-represented, age range being 11 to 80 years. Systemic hypertension (47%), followed by hereditary/congenital conditions (23%) and non-insulin dependent diabetes mellitus NIDDM (19%) were the most common causes of ESRF in the region. One patients developed ESRF 14 years after donor nephrectomy. Overall prevalence of HCAb was 50% with a range of 17.24% to 83%. Based, especially, on the findings in two of the units which between them handle 57% (55/96) of the patients, we believe that the practice of machine isolation policy (MIP) rather than blood transfusion is largely responsible for this wide variation in prevalence between the centres. Considering the very high overall prevalence of the Kingdom, we suggest the MIP should no longer be optional and should be part of the universal infection precautions for HD patients. Comparing Gassim with findings from Taif, there may be some variation in the pattern of ESRF between different parts of the Kingdom. More reports will be needed to document this. Donor nephrectomy as a cause of ESRF is being recorded for the first time in the Kingdom. Vigilance is important. Similarly, we believe that sexual intercourse as a probable route of hepatitis C virus HCV transmission is being recorded for the first time in the Kingdom.

Adolescent↗

Wolcott-Rallison syndrome.

Two sibs with early onset diabetes and epiphysed dysplasia (Wolcott-Rallison syndrome) are described. The epiphyseal changes were radiologically apparent at 6 months of age in one of them, and both developed insulin dependent diabetes in the first few weeks of life. The clinical and radiological features of this syndrome are reviewed.

Diabetes Mellitus, Type 1↗

Interaction of naturally occurring aflatoxins in poultry feed and immunization against fowl cholera.

A total of 1,175 poultry feed samples originating from different farms were analyzed for aflatoxin. Poor growth rate and reduced egg production were the main complaints. The rate of contamination with aflatoxin ranged from 10 to 54% of all samples. Of samples examined 30.7% proved positive for aflatoxin with a concentration ranging from 1 to 2,000 ppb. Outbreaks of fowl cholera were diagnosed on two farms where aflatoxin was detected in the rations used. The impact of aflatoxin in the feed on the efficacy of immunization against fowl cholera was monitored by a hemagglutination test and the titers of the involved farms were compared with experimental groups fed on aflatoxin-free rations and vaccinated with the same polyvalent fowl cholera bacterin. The antibody titers of the experimental groups were 4 to 15 times higher than those of the involved farms.

Aflatoxin B1↗

[Thyroid ectopia and Basedow's disease].

Graves' disease was diagnosed in a 35-year old woman with a history of myxoedema in childhood. Clinical data, ultrasonography and radioisotope scanning showed that the disease had developed in an ectopic subhyoid thyroid gland. Although numerous thyroid diseases associated with an ectopic thyroid have been described, Graves' disease does not seem to be frequent since only one case has been published so far.

Adult↗

[Homozygous infant in a family with hereditary protein C deficiency].

We report on a female infant homozygous for protein C deficiency in a Jordanian family with frequent intermarriage. A protein C antigen of 0.6% was determined. The parents first noticed painful nodular indurations in subcutanous tissue as well as blue-red skin coloration at the age of 6 months. The girl repeatedly suffered from microthrombotic events in parts of the body with large areas of subcutaneous fat. In contrast, the numerous heterozygous carriers with partial protein C deficiency did not show an increased tendency to thrombosis. From the history an autosomal-recessive inheritance may be inferred. Other authors reporting on homozygous cases also postulate the presence of a recessive gene. It is of interest that the infant described here differs from those in other case reports in the age at manifestation of the disease. The homozygous infant showed the first symptoms as late as the age of 6 months, whereas other case reports describe severe symptoms immediately after birth. All symptoms of disease were treated successfully with prothrombin complex concentrate without additional heparin protection. Microthrombotic events subsided quickly, and a large ulcer in the left flank healed almost completely within 6 days.

Adult↗

[Extra-arachnoid subdural injection, an accident of peridural anesthesia].

Two cases are presented, with accidents of peridural anesthesia, Anesthesia of the entire brain stem, paralysis of the intercostal muscles, and of the upper limbs, apnoea and miosis that developed later indicate an extension of the anesthetic effects far higher that it could have been expected considering the technical details of the procedure. On the other hand the absence of any durable coma, of extreme mydriasis, and of severe arterial hypotension, as well as the relatively rapid retrocession of the additional effects of the administration of an anesthetic exclude the possibility of total rachianesthesia, and it can be concluded that there was an accidental injection of anesthetic in the extra-arachnoid subdural space.

Adult↗