Search PubMed⌕ Search

Biomedical subjects

M Zakaria

Publications and source records attributed to M Zakaria.

At least 19 recordsLinked to original sources
PubMed2005

[Percutaneous compression plate for pertrochanteric fixation of hip fractures: surgical technique and first results].

We have used a minimally invasive technique for fixation of trochanteric fractures since 2003. We use the percuntaneous compression plate described by Gotfried. We describe here the osteosynthsis technique and our special approach which limits operative time. This technique avoids wide opening of the aponeurosis of the tensor fascia lata, major detachment, and section of the vastus lateralis. The plate is inserted via a 2-cm incision over the greater trochanter. Head and shaft screws are inserted via a second incision measuring 3 to 4 cm. Perfect reduction before plate insertion is the key to success. The results of our first twenty cases have demonstrated an uneventful postoperative period and a short operative time of 25 minutes on average. Peri-operative bleeding has been very limited. Radiographic healing was obtained in three months. Weight bearing was possible immediately after fixation in five cases and was delayed in fifteen. There were two early displacements which were analyzed.

Aged↗
PubMed2004

Human metabolism of radiocaesium revisited.

Three adult volunteers (2 males and 1 female) have ingested radioactive caesium in two edible forms in order to compare the gastrointestinal uptake and the subsequent short-term and long-term biokinetics. Foodstuffs made of fresh-water fish or mushrooms from regions in Sweden of high 137Cs deposition was ingested together with a 134CsCl-solution mixed with soft drinks. Whole-body countings of 134Cs and 137Cs were performed in the Malmo whole-body counter during a period of approximately 50 d prior to, and 200-300 d after the ingestion. Urine and faeces were collected the day before and up to 7-10 d after the test meals, and analysed for 134Cs and 137Cs. No significant difference in the gastrointestinal uptake fraction, f0=0.98, between caesium incorporated into a foodstuff matrix and caesium in ionic form was detected. Cumulated faecal excretion during 7 d after ingestion accounted for 2-3% of the intake. No significant difference in the long-term biological half-time was found between caesium present in a food matrix and in an aqueous solution in any of the volunteers.

Administration, Oral↗
PubMed1999

Divergent roles for thyroid hormone receptor beta isoforms in the endocrine axis and auditory system.

Thyroid hormone receptors (TRs) modulate various physiological functions in many organ systems. The TR alpha and TR beta isoforms are products of 2 distinct genes, and the beta 1 and beta 2 isoforms are splice variants of the same gene. Whereas TR alpha 1 and TR beta 1 are widely expressed, expression of the TR beta 2 isoform is mainly limited to the pituitary, triiodothyronine-responsive TRH neurons, the developing inner ear, and the retina. Mice with targeted disruption of the entire TR beta locus (TR beta-null) exhibit elevated thyroid hormone levels as a result of abnormal central regulation of thyrotropin, and also develop profound hearing loss. To clarify the contribution of the TR beta 2 isoform to the function of the endocrine and auditory systems in vivo, we have generated mice with targeted disruption of the TR beta 2 isoform. TR beta 2-null mice have preserved expression of the TR alpha and TR beta 1 isoforms. They develop a similar degree of central resistance to thyroid hormone as TR beta-null mice, indicating the important role of TR beta 2 in the regulation of the hypothalamic-pituitary-thyroid axis. Growth hormone gene expression is marginally reduced. In contrast, TR beta 2-null mice exhibit no evidence of hearing impairment, indicating that TR beta 1 and TR beta 2 subserve divergent roles in the regulation of auditory function.

Animals↗
PubMed1998

Successful repair of cardio-Behçet's disease with aortic and mitral regurgitation.

A case of Behçet's disease with cardiac involvement of aortic and mitral regurgitation is presented. The patient underwent aortic and mitral valve replacement, along with plication of the ascending aorta. Histological examination revealed chronic inflammation with degenerative changes, consistent with Behçet's disease. Anti-inflammatory therapy using prednisolone was maintained throughout the postoperative period. This is the first case of cardio-Behçet's disease surgically treated for both aortic and mitral valves with a successful long-term survival.

Aortic Valve Insufficiency↗
PubMed1997

Regulation of gonadotropin-releasing hormone (GnRH) gene expression by insulin-like growth factor I in a cultured GnRH-expressing neuronal cell line.

A GnRH-expressing neuronal cell line (NLT) was used to determine whether insulin-like growth factor I (IGF-I) regulates GnRH gene expression. A receptor-binding assay demonstrated the expression of IGF-I receptors on NLT cells. Activation of IGF-I receptors induced the Ras/Raf-1/mitogen-activated protein kinase pathway and increased c-fos expression. NLT cells treated with IGF-I underwent cell proliferation and exhibited a growth-independent increase in mouse GnRH mRNA expression. In cells transfected with DNA constructs containing the human GnRH promoter, which includes a consensus AP-1 binding site fused to the luciferase reporter gene, a significant increase in reporter activities was induced by IGF-I, whereas mutation of this AP-1 site significantly reduced IGF-I-induced promoter activation. These results demonstrate that IGF-I serves as an important signal in the regulation of both human and rodent GnRH gene expression.

Animals↗
PubMed1997

Detection of Chlamydia trachomatis in urine samples by polymerase chain reaction and enzyme immunoassay.

First-void urine samples collected from sexually transmitted diseases (STD) clinic patients were examined by a nested polymerase chain reaction (PCR) and a commercial enzyme immunoassay (IDEIA Chlamydia) for the diagnosis of Chlamydia trachomatis urethritis or cervicitis. The primers for the PCR amplified a target in the major outer membrane protein (MOMP) gene in C trachomatis while the IDEIA detected genus-specific chlamydial lipopolysaccharide. Discrepant results were resolved by retesting urine specimens with a second (plasmid-based) PCR and taking urethral or endocervical swab results into consideration. For 231 men (chlamydial prevalence 20.4%), the sensitivity, specificity, positive and negative predictive values were 59.6%, 99.5%, 96.6% and 90.6% for urine IDEIA, 68.1%, 99.5%, 97% and 92.4% for urethral swab IDEIA and 97.9%, 99.5%, 97.9% and 99.5% for urine PCR. The corresponding rates for 66 women (chlamydial prevalence 54.6%) were 19.4%, 100%, 100% and 50.8% for urine IDEIA, 86.1%, 96.7%, 96.9% and 85.3% for endocervical swab IDEIA and 91.7%, 93.3%, 94.3% and 90.3% for urine PCR. Hence, in a high prevalence population, the urine IDEIA was a suitable alternative to the male urethral swab IDEIA but significantly less sensitive than the endocervical swab IDEIA. The urine PCR was, however, much more sensitive than the urine IDEIA for both men and women and could replace the endocervical swab IDEIA for the diagnosis of chlamydial cervicitis.

Adolescent↗
PubMed1997

Haemodynamic correlation with lung biopsy findings in isolated ventricular septal defect with or without pulmonary hypertension.

Pulmonary hypertensive patients have been found to have greater morbidity and mortality from isolated ventricular septal defect closure than those pulmonary non-hypertensive patients. In this study, the author evaluated the relation between pulmonary artery muscularity and pulmonary artery pressure and resistance and compared the haemodynamic effects between normal and raised pulmonary artery pressure groups in isolated ventricular septal defect. The patients were divided into two groups, group-I (n = 14): pulmonary artery pressure of 50 mmHg or less than 50 mmHg, and group-II (n = 6): pulmonary artery pressure more than 50 mmHg. The group-II patients were further studied during cardiac catheterization by inhaling 100% oxygen for 15 minutes to detect any fall in pulmonary artery pressure. The patients whose pulmonary artery pressure did not drop were considered to have operative intervention after lung biopsy. The mean pulmonary artery pressure, right ventricular pressure and pulmonary vascular resistance in group-I and group-II were 26.9 +/- 7.0 mmHg, 44.0 +/- 2.5 mmHg, 2.2 +/- 0.6 units/m2 vs 84.2 +/- 20.7 mmHg, 100.5 +/- 7.0 mmHg, 10.0 +/- 0.9 units/m2, respectively (p < 0.001). The left to right shunt flow in group-I and group-II was 50.6 +/- 6.0% vs 44.0 +/- 8.6%, respectively and was not significantly different (p < 0.1). In the operated group (n = 17), pulmonary artery pressures ranged 20-110 mmHg, size of the VSD 7.5-11.5 mm, and pulmonary vascular resistance 1.7-8.2 units/m2. In isolated ventricular septal defect, when the pulmonary vascular change was reversible, there was a positive correlation both between the VSD size and the level of pulmonary arterial pressure (r = 0.94, p < 0.001) and between the pulmonary arterial pressure and pulmonary vascular resistance (r = 0.95, p < 0.001). Lung biopsy (n = 9) showed grade I Heath-Edward change in 6 cases (66.6%), grade II change in 1 case (11.1%), and grade III in 2 cases (22.2%). From these findings, when pulmonary vascular resistance is 8 units/m2 or more, operative indication should be determined on the basis of lung biopsy. Not only the gradings of pulmonary vascular changes, but the extent of vascular involvement and the duration of the lung exposure to the shunt anomally also need to be considered before surgery.

Adolescent↗
PubMed1996

Phorbol ester regulation of the gonadotropin-releasing hormone (GnRH) gene in GnRH-secreting cell lines: a molecular basis for species differences.

Phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) regulation of the GnRH gene was studied in two mouse GnRH neuronal cell lines, Gn11 and NLT. TPA treatment of NLT cells grown in low serum conditions did not alter endogenous mouse GnRH mRNA levels, indicating that the endogenous mouse gene is not regulated by phorbol esters under these conditions. This result is confirmed in transfection studies in which TPA treatment did not change expression of a mouse GnRH-luciferase reporter gene construct. In contrast, TPA treatment stimulated expression of a human GnRH-luciferase reporter construct, correlating with the expression of the protoon-cogenes c-fos and c-jun. TPA stimulation of the human GnRH gene is mediated by a consensus AP-1 site located at -402 to -396 bp, TGACTCA, which specifically binds c-fos and c-jun in Gn11 and NLT cells and recombinant c-jun in gel mobility shift studies. In contrast, the rodent GnRH genes, when aligned for maximum homology, contain a DNA sequence with a 1-bp difference, TGTCTCA from the human gene. In gel mobility shift studies, this DNA sequence does not form a complex with Gn11 or NLT nuclear extract or with recombinant c-jun. This is the first demonstration of species-specific differences in phorbol ester regulation of GnRH gene transcription and could, in part, explain differences in reproductive function among mammals.

Animals↗
PubMed1992

[Totally implantable systems for long-term chemotherapeutic treatment].

The authors report their own experience with completely implantable systems for the long-term chemotherapeutic treatment, compared with a review of modern literature. The experience even if low demonstrates a good methodology in reducing the number of complications associated with the use of percutaneous catheters.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

The effect of arterial pressure alterations during halothane anesthesia on residual flow and infarct size with transient regional ischemia of the dog.

The present study was designed to determine if infarct size under halothane anesthesia could be reduced by increasing the pressure gradient across the collateral vascular bed, thereby increasing flow within the occluded vascular bed. Forty-nine mongrel dogs were anesthetized with halothane under identical physiologic conditions with the exception of systemic arterial blood pressure. The control group of 18 animals anesthetized with halothane was compared to two experimental groups. In one group of 15 dogs, the mean systemic pressure was raised 25% above control with phenylephrine (BP25). In the second group of 15 dogs, systemic pressure was raised 50% above control (BP50). Adjacent marginal branches of the left circumflex coronary artery were ligated for 90 minutes followed by 90 minutes of reflow. The area of the occluded vascular bed was similar in all groups, but the area of infarction as a percentage of the occluded vascular bed was reduced from 47.7 +/- 4.7% to 25.4 +/- 4.3% in the BP25 group (P < or = .05 v control) and to 33.1 +/- 5.0% in the BP50 group. Flow measurements using microspheres showed a larger zone of ischemic tissue receiving adequate residual flow in the BP25 and BP50 groups compared to the control. It is concluded that infarct size during halothane anesthesia in the dog can be reduced by increasing systemic blood pressure with phenylephrine.

Analysis of Variance↗
PubMed1987

Beneficial effect of thyrotropin-releasing hormone in canine hemorrhagic shock.

The effects of thyrotropin-releasing hormone (TRH) on hemodynamic variables, oxygen delivery (DO2), and oxygen consumption (VO2) variables in canine hemorrhagic shock were studied. Anesthetized adult dogs were bled over 30 min to a mean arterial pressure (MAP) of 50 mm Hg. Shock was maintained at this level for half an hour. The animals were divided alternatively into two groups. In the first group (n = 5) a bolus of TRH (2 mg/kg) was given intravenously. The second group (n = 5) served as control and received equal amounts of D5W. Blood samples were obtained regularly up to 120 minutes after TRH or placebo. Differences in the two groups were statistically tested. After TRH, MAP pressure, cardiac output, and systemic vascular resistance increased significantly. DO2 improved after TRH but VO2 remained unchanged. In all dogs, sequential beta endorphin level were measured and were shown to rise after induction of shock. This data indicates that TRH may be of therapeutic benefit in the treatment of hemorrhagic shock and that beta endorphin may be an important pathophysiologic factor.

Animals↗
PubMed1986

Evolution of cardiorespiratory variables in myxedema coma--a case report.

Normalization of hemodynamic, oxygen transport and oxygen consumption indices occurred within a week of treatment in a patient with myxedema coma. Ventilatory weaning and extubation was achieved using aminophylline, physical therapy and pleural drainage. Before extubation, naloxone was administered without any significant ventilatory improvement or change in endorphin levels.

Coma↗
PubMed1983

Liquid chromatographic profile classification of acute and chronic leukemias.

Reversed-phase high performance liquid chromatography and multivariate discriminant analysis are used for the classification of acute and chronic leukemias. Plasma or serum profiles, mainly of nucleosides, bases, and aromatic amino acids, are segmented into specific retention time intervals. Peak areas in each retention time interval are summed such that the chromatographic profile can be represented as a pattern vector formed from the linear combination of peak areas. The preprocessing techniques of autoscaling and variance weighting minimized inadvertent weighting and reduced the contribution of nondescriptive data components in the development of the discriminant function. The acute lymphocytic leukemia plasma samples and controls were classified with 100% sensitivity and specificity. Chronic leukemia serum samples and controls were categorized with sensitivity and specificity values of 93.7 and 87.6%, respectively.

Acute Disease↗
PubMed1983

Poxvirus infection in a rat (Rattus norvegicus) in Kuwait.

A poxvirus was isolated from skin lesions on the tail of a rat (Rattus norvegicus) in Kuwait in February, 1982. The virus grew on the chorioallantoic membrane (CAM) developing chicken embryos and induced small generalized haemorrhagic pock lesions, 72 hours post-inoculation. It grew also with cytopathic effect (CPE) in CER and Vero cell lines. In cultured cells it produced cell rounding and syncytia 48-72 hours post-infection. The virus was resistant to the effect of ether as well as to chloroform, and showed haemagglutinating activity against chicken red blood cells in a low titer (1:16). It induced in the rabbit skin nodular lesions 4-5 days post-infection. Electron microscopy of the negatively stained preparations revealed brick-shaped typical poxvirus virions measuring 220-250 millmicron in diameter. By using vaccinia antiserum the virus antigen was precipitated in the agargel immunodiffusion test and this indicates its relation to the genus Orthopoxvirus.

Animals↗
PubMed1982

HPLC analysis of aromatic amino acids, nucleosides, and bases in plasma of acute lymphocytic leukemia on chemotherapy.

Plasma chromatograms--obtained by the reversed-phase mode of high performance liquid chromatography (HPLC)--of 19 subjects with acute lymphocytic leukemia (ALL) were compared to those of 19 normal individuals. ALL patients were in remission and on a methotrexate and 6-mercaptopurine maintenance regimen. The concentrations of the aromatic amino acids L-phenylalanine and L-tyrosine, the nucleosides uridine, adenosine, inosine, and guanosine, as well as the bases hypoxanthine and xanthine, were elevated in the leukemic in comparison to the normal chromatograms. Highest inosine levels corresponded to leukemic subjects whose condition severely deteriorated with time. Patients with lower inosine levels are still in continuous remission.

Adenosine↗
PubMed1982

Rapid assay for plasma chlorambucil and phenyl acetic mustard using reversed-phase liquid chromatography.

A rapid assay for chlorambucil, a drug used for the treatment of chronic lymphocytic leukemia, and its major metabolite is described. Chromatographic behaviour of the two compounds on two different reversed-phase columns is discussed, as well as the kinetics of their hydrolysis in aqueous medium. The developed analysis can be applied to the determination of the plasma levels of the drug and its metabolite. No sample preparation is required and the spectrophotometric detection affords the sensitivity in the picomole range. Total analysis time is between 10 and 15 min.

Chlorambucil↗