Biomedical subjects

M Hassan

Publications and source records attributed to M Hassan.

At least 109 records · Page 6Linked to original sources

PubMed1997

Alpha feto-protein and albumin in ascitic fluid in hepatocellular carcinoma patients.

Alpha-feto-protein (AFP) is the most popular tumor marker for hepatocellular carcinoma (HCC). It is used in diagnosis and follow up of cases by estimating its rise in the serum. The aim of this work is to study the value of estimating AFP in ascitic fluid of HCC patients with ascites. This work is a case control study on 32 patients, including 22 cases with ascites and HCC and 10 control group with ascites due to liver cirrhosis without HCC. The level of AFP was estimated in serum and in ascitic fluid by Radio-immuno assay RIA. The serum ascites albumin gradient (SAAG) was assessed by measuring albumin in all samples using bromocresole green dye binding. Guided aspiration liver biopsy and ascitic fluid cytology was done, stained with H & E. It was found that, AFP level in serum was elevated in 72.7% of HCC patients, and in ascitic fluid was elevated 63.6% HCC patients. Also, there was a highly significant, direct positive correlation between elevation of AFP in serum and in ascitic fluid (r = 0.778). No elevation of AFP in serum and in ascitic fluid was detected in control group. Ascitic fluid cytology showed malignant cells in one case only. SAAG was significantly lower in the HCC group 0.83 gm/dl than the control group 2.43 gm/dl (p-value < 0.001). Elevation of AFP in ascitic fluid is of high importance in evaluation of HCC, and is as significant as serum and runs parallel to it. Estimation of AFP in ascitic fluid is much more significant in evaluation of HCC cases than ascitic fluid cytology.

Ascitic Fluid↗

PubMed1997

Supratentorial parenchyma in the developing fetal brain: in vitro MR study with histologic comparison.

PURPOSE: To assess the in vitro MR signal of the developing brain through histologic comparisons. METHODS: Five healthy fetal specimens aged 16, 19, 22, 27, and 34 gestational weeks were studied in vitro using T1- and T2-weighted sequences in frontal and axial planes. Neuropathologic studies included sections in the same frontal plane. Comparison of histologic sections with measurements of the relative widths of the layers of different signal intensities enabled us to assign cellular correspondence to each MR layer. RESULTS: In the cerebral mantle, a layered pattern was observed on both T1- and T2-weighted images. In the basal ganglia, signal from the pallidum and thalamus was isointense with white matter from 16 to 22 weeks' gestation; then, from 27 and 34 weeks' gestation, the signal was relatively high on T1-weighted images and low on T2-weighted images. The neostriatum had a relatively low signal on T1-weighted images and a high signal on T2-weighted images from 16 to 27 weeks' gestation: then, at 34 weeks' gestation, the signal was relatively high on T1-weighted images and low on T2-weighted images. CONCLUSION: MR imaging can clearly show specific patterns of growing fetal brain in vitro.

Basal Ganglia↗

PubMed1997

A phase I trial of radiotherapy and simultaneous 24-hour paclitaxel in patients with locally advanced head and neck squamous cell carcinoma.

Preclinical studies have demonstrated that tumor cells exposed to paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) for protracted periods (ie, 24 hours) and then irradiated undergo enhanced radiation-induced cell kill. Importantly, paclitaxel-induced tumor cell mitotic arrest at the time of radiation was associated with the enhanced cell kill. At the Case Western Reserve Cancer Center, we have conducted a phase I trial in 24 patients with either locally advanced or recurrent/metastatic head and neck squamous cell carcinoma to evaluate the clinical and pharmacologic effects of a 24-hour paclitaxel infusion combined with radiotherapy. The maximum tolerated dose was < or =75 mg/m2. Dose-limiting toxicity was febrile granulocytopenia. Mucositis was significant and necessitated the use of enteral feeding tubes in the majority of patients. All patients with locally advanced disease demonstrated either a complete response or major partial response. At a median follow-up of 13.4 months, disease has relapsed in only two of 22 patients with locally advanced disease. Pharmacokinetic studies revealed that a dose of > or =75 mg/m2 achieved near steady-state mean paclitaxel plasma concentrations greatly exceeding the threshold concentrations shown to alter microtubule function and induce tumor cell mitotic arrest in vitro. Pharmacodynamic studies performed at 21 to 26 hours after initiation of infusion demonstrated that a dose of > or =75 mg/m2 uniformly induced tumor cell mitotic arrest and oral epithelial mitotic arrest. The pharmacologic data and outcome results provide a strong rationale for the continued use of a 24-hour paclitaxel infusion and concurrent radiation for the treatment of newly diagnosed, locally advanced head and neck squamous cell carcinoma in an experimental setting.

Adult↗

PubMed1997

[Imaging of meconium peritonitis of pseudotumor clinical presentation].

An unusual case of meconium peritonitis is reported. A neonate presented with a huge multiseptate effusion in the peritoneal cavity in relation with a small bowel perforation. No calcification was visible. Such a presentation cannot be included in one of the classical types of meconium peritonitis. It could be due to a bowel perforation occurring immediately before birth and could therefore be related to a mixed fibroadhesive and generalized form.

Diagnosis, Differential↗

PubMed1996

[Magnetic resonance imaging of the fetus. Contribution to antenatal diagnosis].

Magnetic resonance imaging (MRI) of the fetus has been developed over the last 10 to 15 years. This new imaging technique cannot remplace ultrasonography which remains the key examination for antenatal diagnosis but can add further improvements over ultrasonographic findings, particularly in evaluating the fetal brain. MRI of the fetus has thus been focused in this area, the main studies aiming at analyzing brain malformations and at searching for ischemic or hemorrhagic lesions and possible gyration anomalies. Advances in data processing software and volume acquisition and the development of the echo-planar technique and T2-weighted sequences are currently under study. MRI of the fetus has thus progressed rapidly. It is however a long costly examination which may not be well tolerated by pregnant women. Currently, routine MRI of the fetus is not possible, because of the requirement for specialized facilities. This new technique, still in the evaluation phase, should be studied using strict protocols reserved for centers specialized in antenatal diagnosis.

Female↗

PubMed1996

Optimization and visualization of molecular diversity of combinatorial libraries.

One of the major goals of rational design of combinatorial libraries is to design libraries with maximum diversity to enhance the potential of finding active compounds in the initial rounds of high-throughput screening programs. We present strategies to visualize and optimize the structural diversity of sets of molecules, which can be either potential substituents to be attached at specific positions of the library scaffold, or entire molecules corresponding to enumerated libraries. The selection of highly diverse subsets of molecules from the library is based on the stochastic optimization of 'Diversity' functions using a single-point-mutation Monte Carlo technique. The Diversity functions are defined in terms of the distances among molecules in multidimensional property space resulting from the calculation of 2D and 3D molecular descriptors. Several Diversity functions, including an implementation of D-Optimal design, are applied to select diverse subsets and the results are compared. The diversity of the selected subsets of molecules is visualized by embedding the intermolecular distances, defined by the molecules in multidimensional property space, into a three-dimensional space.

Amino Acids↗

PubMed1996

Nasal pyriform aperture stenosis and absence of the anterior pituitary gland: report of two cases.

We describe two female infants with congenital nasal pyriform aperture stenosis and severe pituitary insufficiency. The anterior pituitary gland was undetectable with magnetic resonance imaging. Consanguinity of parents in both cases suggests autosomal recessive inheritance of this disorder. An early fetal developmental defect may explain this syndrome, which affects midline craniofacial structures. In patients with congenital pyriform aperture stenosis, magnetic resonance imaging of the brain and endocrine investigations should be performed for rapid diagnosis and treatment of the latter to avoid major neurologic complications.

Abnormalities, Multiple↗

PubMed1996

Prevalence of asthma and wheeze in primary school children in northern Jordan.

In order to determine the prevalence of asthma and wheeze in Northern Jordan, a questionnaire was distributed to 3540 school children aged 6-12 years in Irbid City. The completed questionnaires were returned by 3182 children, a response rate of 90%. The prevalence of physician-diagnosed asthma was 4.1%. Wheezing was reported by 8.3% of children. The male:female ratio was 2:1 for both conditions. In order of frequency, the triggering factors were respiratory tract infections, cold environment, exercise and dust. Statistically significant associations between wheezing (including asthma) and a family history of asthma, recurrent chest infections, eczema, allergic rhinicis and parental smoking were detected. Mode of delivery, breastfeeding and the presence of pets at home were not significantly associated. The prevalence of childhood asthma in Northern Jordan is similar to that in some countries of the developed world. Underdiagnosis may explain the relatively low prevalence of asthma found in this study population.

Asthma↗

PubMed1996

3D object localization using EIT measurements at two levels.

Electrical impedance tomography (EIT) is designed essentially for two-dimensional imaging, but current flow in the third dimension causes images to be formed for objects in 3D. The present work has shown that the image of an object is shifted in position towards the centre almost linearly with the 3D distance from the electrode plane and that the slope of this linear variation depends on the radial distance of the object. An empirical curve has been fitted to this dependence, based on which a method has been developed to locate 3D point objects from EIT measurements in only two planes. This will be useful in clinical and other applications in which 3D objects are few and widely separated. This new methodology may be the basis for 3D imaging in the future.

Electric Impedance↗

PubMed1996

Visceral leishmaniasis in Pakistani children.

Visceral leishmaniasis is endemic in Pakistan. No studies of visceral leishmaniasis in childhood have been reported from Pakistan. We prospectively studied clinical and laboratory features in 58 Pakistani children with visceral leishmaniasis. Mean age of the children was 2.9 years. Fever, pallor, and abdominal distention were the most common clinical manifestations, and hematologic abnormalities were the most common laboratory findings. All children recovered after antimicrobial therapy. Pakistani children with visceral leishmaniasis tended to be younger than affected children from Africa and were less likely to have lymphadenopathy.

Abdomen↗

PubMed1996

Do nonprofit hospitals pay their way?

Using 1988 and 1991 data from nonprofit voluntary hospitals in California, we find that the vast majority of nonprofit hospitals provide community dividends in excess of the tax subsidies they receive. However, nearly 20 percent of nonprofit hospitals do not meet this standard. Further, those hospitals that do not meet the standard tend to not meet the standard over time. We recommend more explicit identification of the community dividends expected in return for special tax treatment and more explicit accounting on the part of nonprofit hospitals.

California↗

PubMed1996

Subcutaneous or intramuscular injections of insulin in children. Are we injecting where we think we are?

OBJECTIVE: This study was designed to assess the insulin injection location in a group of children who had their injection according to their daily practice, thought to lead to subcutaneous injections. RESEARCH DESIGN AND METHODS: The location of the insulin deposit at the injection site was visualized using an ultrasound device. RESULTS: The exact insulin injection location could be localized, and 18 of 59 injections (30.5%) (one injection for each child) were in the intramuscular tissue. Of the children who had intramuscular injection, 15 of 18 were boys. The children who had an intramuscular injection had a significantly lower percentile of BMI (mean +/- SE: 47 +/- 8 vs. 72 +/- 4, P = 0.004), lower distance from skin surface to muscle fascia without a skinfold (5.6 +/- 0.6 vs. 11 +/- 0.7 mm, P < 0.0001), and a lower distance from skin surface to muscle fascia with a skinfold (8.1 +/- 0.9 vs. 15.9 +/- 0.8 mm, P < 0.0001) than children who had a subcutaneous insulin injection. CONCLUSIONS: We identified a group of children at risk for intramuscular insulin injections and that may deserve specific injection technique and advice.

Analysis of Variance↗

PubMed1996

Aspects concerning busulfan pharmacokinetics and bioavailability.

Busulfan as a high-dose therapy is an important component of many of the myeloablative regimens for both allogeneic and autologous bone marrow transplantation (BMT) in adults and children. During the last decade, several studies have shown a wide inter- and intra-patient variability of busulfan disposition in adults and children. Some of the factors affecting the interpatient-variability were identified as circadian rhythmicity, age, disease, drug interaction, alteration in hepatic function and recently busulfan bioavailability. In adults, pharmacodynamic studies have shown a positive correlation between high-systemic exposure of the drug and venocclusive disease (VOD). However, pharmacodynamic studies in children did not establish any correlation between the systemic exposure and VOD. Drug-monitoring and dose adjustment in adults were used successfully to decrease the occurrence of VOD and mortality. It was observed that about 20% of the busulfan dose crosses the blood brain barrier. The high amount of the drug which enters the brain can probably be involved in the CNS toxicities reported. In children, a low rate of toxicity combined with a high rate of engraftment failure were observed. Several investigators have expressed their concern about the dosage in children and many suggested higher doses based on the body surface area for young children. However, recently it was shown that busulfan bioavailability varied by 2-fold in adults (0.5-1.03) while in children a 6-fold variation was observed (0.22-1.20). The access to an intravenous form of busulfan and a deeper understanding of pharmacodynamics of the drug might be essential to optimize the treatment, reach a successful engraftment and lower the therapy related toxicities.

Adolescent↗

PubMed1996

Risks in using siphon-reducing devices in adult patients with normal-pressure hydrocephalus: bench test investigations with Delta valves.

To elucidate the reason for malfunction of Delta valves in patients with normal-pressure hydrocephalus, the authors applied a new concept of the bench test and simulated intracranial pressure (ICP) to measure the resultant flow with a complete shunt system. Subcutaneous pressure on the valve, valve implantation site, and postural hydrostatic differential-pressure changes were simulated in this bench test designed for adult patients with normal-pressure hydrocephalus. Subcutaneous pressure ranged within 6.4 +/- 0.09 cm H2O (mean +/- standard deviation) on the 7th day after the implantation of the valve in rats. A linear correlation between valve closing pressures and the external pressure was observed: gradual increase of the latter resulted in an approximately equal rise in the closing pressure. Closing pressure ranged within the physiological variation of ICP (10 +/- 5 cm H2O) in the supine position. In the erect position it was higher than the physiological variation (+5 to -5 cm H2O) when the valve was placed at the level of the foramen of Monro and lower when placed at the level of the clavicle. This observation indicates that the subcutaneous pressure around the Delta valve significantly affects its closing pressure. An excessive reduction of flow or a functional obstruction occurs when the patient with a Delta valve implanted at the foramen of Monro assumes an erect posture. The authors conclude that Delta valves are not recommended for implantation at the level of the foramen of Monro in patients with normal-pressure hydrocephalus because of the risk of underdrainage. The mastoid process or clavicle may be the alternative levels for its implantation to prevent underdrainage; however, the possibility of shunt malfunction should be kept in mind because subcutaneous pressure is variable among patients and that might affect the performance characteristics of these valves.

Animals↗

PubMed1996

Acute respiratory infections: sentinel survey in Egypt.

A survey of 115 health centres in five governorates provided morbidity figures for acute respiratory infections (ARI) from 75,789 records. The findings give an estimate of antibiotic requirements, including dosage forms for young children, and help evaluate the performance of individual health centres and the entire ARI programme.

Acute Disease↗

PubMed1996

Busulphan kinetics and limited sampling model in children with leukemia and inherited disorders.

Busulphan pharmacokinetics were investigated in 20 children, who underwent bone marrow transplantation for either leukemia or inherited disorders. Busulphan (1.90-6.02 mg/kg/day) was administered orally as a single dose or twice daily. Busulphan kinetics were found to be linear within the studied range. Children with inherited disorders eliminated busulphan significantly faster after the first and the last dose with half-lives (t1/2) of 1.93 and 1.71 h, respectively compared to children with leukemia (3.16 and 2.70 h, respectively). The area under plasma concentration curves (AUCs, corrected for mg/kg) as an expression for the systemic exposure of busulphan were significantly higher in children with leukemia, 22.4 and 19.04 mumol/l.h (5527 and 4690 ng.h.ml-1) after the first and the last dose, respectively, compared to 11.2 and 8.2 mumol/l.h (2768 and 2029 ng.h.ml-1) found in children with inherited disorders. The present results confirm those reported by others, ie busulphan pharmacokinetics can be influenced by the underlying disease and its status. Our population pharmacokinetic analysis showed a negative correlation between the weight corrected clearance and the age in both groups of children. However, clearance was about 42% higher in children with inherited disorders compared to those with leukemia. To estimate AUC for the first dose, we evaluated a limited sampling model based on three concentrations (1, 3 and 6 h). A high correlation (r = 0.998, P < 0.0001, n = 40) between the estimated and the determined AUC was found. The present model is reliable and adequate for studying more patients, with a long-term follow-up combined with drug monitoring in correlation with drug efficacy and toxicity to define the optimal busulphan dosage required.

Administration, Oral↗

PubMed1995

Conformational analysis of endothelin-1: effects of solvation free energy.

In order to investigate conformational preferences of the 21-residue peptide hormone endothelin-1 (ET-1), an extensive conformational search was carried out in vacuo using a combination of high temperature molecular dynamics/annealing and a Monte Carlo/minimization search in torsion angle space. Fully minimized conformations from the search were grouped into families using a clustering technique based on rms fitting over the Cartesian coordinates of the atoms of the peptide backbone of the ring region. A wide range of local energy mining were identified even though two disulfide bridges (Cys1-Cys15 and Cys3-Cys11) constrain the structure of the peptide. Low energy conformers of ET-1 as a nonionized species in vacuo are stabilized by intramolecular interaction of the ring region (residues 1-15) with the tail (residues 16-21). Strained conformations for individual residues are observed. Conformational similarity to protein loops is established by matching to protein crystal structures. In order to assess the influence of aqueous environment on conformational preference, the electrostatic contribution to the solvation energy was calculated for ET-1 as a fully ionized species (Asp8, Lys9, Glu10, Asp18, N- and C-terminus) using a continuum electrostatics model (DelPhi) for each of the conformers generated in vacuo, and the total solvation free energy was estimated by adding a hydrophobic contribution proportional to solvent accessible surface area. Solvation dramatically alters the relative energetics of ET-1 conformers from that calculated in vacuo. Conformers of ET-1 favored by the electrostatic solvation energy in water include conformers with helical secondary structure in the region of residues 9-15. Perhaps of most importance, it was demonstrated that the contribution to solvation by an individual charge depends not only on its solvent accessibility but on the proximity of other charges, i.e., it is a cooperative effect. This was shown by the calculation of electrostatic solvation energy as a function of conformation with individual charges systematically turned "on" and "off". The cooperative effect of multiple charges on solvation demonstrated in this manner calls into question models that relate solvation energy simply to solvent accessibility by atom or residue alone.

Amino Acid Sequence↗

PubMed1995

Fetal bone age revisited: proposal of a new radiographic score.

In order to establish a fetal bone age score, the post-mortem skeletal radiographs of 85 selected normal fetuses aged from 15 to 41 weeks of gestation (WG) were analysed. Twenty-eight skeletal areas were selected for which quantitative and/or qualitative criteria were defined. Each new aspect was graded and statistically tested by the stepwise linear regression method. Two modalities of scores and decreasing complexity were then designed. The use of these two scores permitted the assessment of the fetal age with r2 values of 0.97 and 0.96 (standard error of estimation of 1.19 and 1.36 WG). Applied to 15 intrauterine growth retardation (IUGR) fetuses, the age estimated by these scores was well correlated with the age obtained by extraosseous criteria of maturation. This method is proposed as a tool for determining, the fetal age during necropsy and could also be useful in US prenatal evaluation.

Age Determination by Skeleton↗