Biomedical subjects
Publications and source records attributed to S Ali.
Patients with generalized anxiety who have not responded to psychological treatment from their family doctor may require symptomatic drug treatment whilst awaiting specialist therapy. This study indicates that propranolol is effective and relatively safe for this purpose. Atenolol is also effective but has unacceptable cardiovascular effects in anxious patients.
Twenty-nine cataractous human lenses between the ages of 36 and 93 were investigated. The total water content of cortex and nucleus were obtained by vacuum dehydration. The freezable water content was measured by differential scanning calorimetry. The non-freezable water content was obtained by difference. To measure the extent that syneresis contributes to cataract formation, an excess function was designed. The excess function represents the changes that occur, for example, in non-freezable water content due to cataractogenesis. It is calculated as the difference between the non-freezable water content of a normal lens and that of a cataractous lens of the same age. On the average, there is 7% less non-freezable water in the cortex of a cataractous lens than in the cortex of a normal lens. The corresponding number for the nucleus is 9%. This represents 29 and 36% changes, respectively, in the cortex and nucleus due to syneresis during cataractogenesis.
Twenty-three human lenses from age 3-76 years were studied. Lenses obtained 24-36 post-mortem were exposed to monochromatic light (435.8 and 546.1 nm) in the I parallel and I+ modes and to white (tungsten lamp) unpolarized radiation. The light scattering intensities were obtained as a function of scattering angles from 0 to 135 degrees. The scattering intensities in the forward directions are greater than in the back scatter in all modes of illuminations. The age dependence of a number of light scattering parameters such as percent transmission; I theta/Io; dissymmetry and depolarization were obtained using regression analysis. These parameters may serve as standards of normal lenses to which similar parameters of cataractous lenses can be compared. Relationships between back scatter and forward scatter have been established using the regression coefficients. Thus, the light scattering intensity observed in the slit lamp (at 135 degrees back scatter) can be quantitatively related to the light reaching the retina at different angular displacements.
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Between July 1979 and October 1984, 61 systemic-pulmonary arterial shunts were created in 45 patients. Clinical and angiographic results with 23 classic Blalock-Taussig shunts (BTSs) and 35 modified Blalock-Taussig shunts (MBTSs) with polytetrafluoroethylene grafts between the subclavian and pulmonary arteries were compared. Forty-three of the patients studied were infants: 28 were less than 1 month old, and 19 were less than 1 week old. Weights were 1.1 to 19 kg (mean 2.9 kg). Diagnoses were complex tetralogy of Fallot (18 patients), transposition of the great arteries with small left ventricle or left ventricular outflow tract obstruction (six patients) pulmonary atresia (seven patients) with intact ventricular septum (three) and ventricular septal defect (four), tricuspid atresia (four patients), univentricular heart (six patients), atrioventricular septal defect (canal) with pulmonary stenosis (three patients), and double-outlet right ventricle (one patient). Comparison groups were concurrent and were equivalent for age, weight, and complexity of anomaly. Patients were removed from the study population at the time of subsequent open heart surgery or at death. All patients were followed for a minimum of 6 months and for up to 5 1/2 years (BTS 1 1/2 to 5 1/2 years, mean 33 months; MBTS 6 months to 3 years, mean 20 months). There were no intraoperative deaths in either group. Among the 23 BTSs, three failed at 1, 3, and 19 days, resulting in two deaths (17%). One premature infant died despite a second shunt, one died during attempted intracardiac repair at 13 days of age, and the other was well after revision of the shunt. Eight patients underwent subsequent intracardiac repair 1 to 5 years (mean 34 months) after the initial procedure. Another four patients died from complex intracardiac anomalies with patent shunts. Three patients are alive 2 to 4 years after receiving shunts and have not undergone subsequent surgery. Late postoperative angiograms demonstrate a disturbing incidence (21%) of stenosis and right pulmonary arterial deformity despite satisfactory immediate postoperative studies and good clinical function. Eight patients required a second shunt, two for anatomic discontinuity of the pulmonary arteries and six because of inadequate blood flow through the first shunt. Among the 35 patients receiving the MBTS, two required early revision (technical error and ductal tissue at the anastomosis). There were no shunt-related deaths, but three (6%) occurred within 30 days of operation from left ventricular infarct, cerebral hemorrhage, sepsis, and severe aortic stenosis with arrhythmias.(ABSTRACT TRUNCATED AT 400 WORDS)
The biochemical changes in rat lungs due to intratracheal instillation of 50 mg of slate dust have been studied up to 150 days of dust exposure. The remarkable feature of lung changes was the turnover of collagen in experimental animals after 90 days, reaching substantially higher values at 150 days. A concurrent increase in hexosamine and sialic acid contents was also observed. The phospholipid content in the whole lung tissue, as well as in the mitochondria, was generally higher in the dust-treated rats, particularly at the later stages. The mitochondrial cytochrome c oxidase and glutamate dehydrogenase activities increased, whereas monoamine oxidase was marginally affected. Mitochondria from experimental animals appeared to be in a swollen state, particularly at 120 days of exposure. The above results suggest that slate dust exerts its toxic effects by causing alterations in the tissue make-up as well as in the mitochondrial functioning of the lung.
Sixty-four consecutive patients with penetrating cardiac injuries were treated between January, 1977, and January, 1983, at the University of Maryland Hospital. Twenty-eight patients had major associated injuries of other organs. The patients were divided into groups according to their clinical status on arrival. An aggressive approach was utilized including early emergency room (ER) thoracotomy for "lifeless" or deteriorating patients. Three patients required immediate cardiopulmonary bypass for repair of their injuries. Twenty-one (57%) of the 37 patients undergoing ER thoracotomy survived; most of the deaths occurred in patients arriving "lifeless" from gunshot wounds. Twenty-four (89%) of the 27 patients who were in stable enough condition to undergo initial repair in the operating room (OR) survived. Overall survival was 45 patients (70%). Though superficial wound infections developed in 18 patients, there were no deep or systemic infections. None of the survivors sustained severe neurological sequelae. Five patients underwent late reoperations for closure of a ventricular septal defect (2), mitral valve replacement (1), and pericardiectomy (2) with no deaths. Though repair of penetrating cardiac injuries should preferably be carried out in the OR, immediate thoracotomy for "lifeless" or deteriorating patients can be performed in the ER with a low incidence of direct surgical complications and with high patient survival.
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Vibrio cholerae O1 strains belonging to both biotypes (classical and El Tor) and both serotypes (Ogawa and Inaba) produced neuraminidase which was released rather than cell bound. Classical strains made more neuraminidase than did El Tor strains. About one-third of V. cholerae non-O1 strains and one-fourth of Aeromonas hydrophila strains were neuraminidase positive. Strains of enterotoxigenic Escherichia coli, Vibrio parahaemolyticus, and Shigella spp. did not produce detectable neuraminidase.
The viscoelastic behavior of and the transport of molecules in the vitreous is influenced by the binding of water to the macromolecular components. The macromolecular components are unevenly distributed in the vitreous. Therefore, it is of interest if the bound water, which can be identified with the non-freezable water content, is also unevenly distributed in the vitreous. Differential scanning calorimetric measurements between -30 degrees C and 15 degrees C were performed on samples from different regions of bovine vitreous body. From the endotherms the amount of freezable water content was calculated. The total water content of the vitreous was measured by vacuum dehydration. There is a slight increase in the non-freezable water content when one proceeds from the lens to the retina along the optic axis. The average amount of non-freezable (bound) water content of the vitreous is high, approximately 20% of the total water content.
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The subclavian flap repair for coarctation of the aorta allows potential for growth by utilizing autogenous tissue. Although well documented in young children, its promise in the tiny neonate warrants further evaluation. Since August, 1979, 29 patients, including 24 infants, have undergone subclavian flap repair at the University of Maryland Hospital. Weights ranged from 1.4 to 5 kg (mean 3.2 kg). All patients less than 6 months old had associated intracardiac defects and were in severe congestive failure. Fifteen responded to preoperative prostaglandin infusions. The overall early mortality was 14%; among the neonates it was 21%; and among those operated upon within the first week of life, 33%. There was one intraoperative death among the eight patients who underwent simultaneous pulmonary artery banding. There were no deaths among patients older than 5 days at operation. Four of the five neonates who died had some variant of hypoplastic left heart syndrome, with severe stenosis or atresia of the systemic atrioventricular valve, critical aortic stenosis, or hypoplastic left ventricle. Twenty-two survivors continue to do well up to 3.7 years postoperatively (mean follow-up 26 months). At follow-up all patients are normotensive with brisk lower extremity pulses. Patients now weigh 1.3 to 6.9 (mean 2.3) times their operative weight, and only one patient has a measured arm-to-leg gradient greater than 10 mm Hg (mean gradient 3.7 mm Hg). Seven of the neonates have undergone repeat catheterization, and all had satisfactory growth of the subclavian flap segment of repair and no gradient. Two older patients (3 and 4 years old at operation) have undergone exercise testing 3.7 years after repair, with peak exercise gradients of only 7 and 15 mm Hg. We therefore continue to utilize this technique for the treatment of coarctation even in tiny neonates.
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A batch of lyophilised human diploid-cell-strain rabies vaccine was divided into three batches, which were exposed to different temperatures during their distribution to and storage at three centres in Pakistan. Vaccine potency after exposure to these temperatures was tested by measuring antibody response in those given the vaccine, and by three different laboratory tests. The results indicate that the vaccine retains its antigenicity for man and for laboratory tests despite continuous exposure to high ambient temperatures for up to 11 weeks. These findings, together with current developments in vaccine manufacture and treatment schedules, offer considerable hope to many countries with low budgets for health care and where rabies is poorly controlled.
By employing 5-BrdU/AO fluorescence technique to distinguish active from inactive X-chromosomes, we have, for the first time, provided evidence in support of the validity of this technique for a non-mammalian system Gryllotalpa fossor (Orthoptera). In the female somatic cells of Gryllotalpa, it is only in the active (euchromatic) arm of X-chromosome that the fluorescence is bright, whereas it is dull in the facultative and constitutive heterochromatic arms. In tetraploid spermatogonial cells one of the two X-chromosomes is inactive, suggesting that this phenomenon is probably a random one and that the inactivation process is independent of the imprinting mechanism.
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A number of isolates of Vibrio cholerae were examined with respect to their (i) surface hydrophobicity as measured by hydrophobic interaction chromatography, (ii) capacity to agglutinate erythrocytes, and (iii) ability to bind to an ion-exchange matrix. V. cholerae isolates, cultured under a variety of growth conditions, were conspicuously hydrophobic. The hydrophobicity was accentuated when these strains were (i) cultivated in a chemically defined synthetic medium, (ii) harvested at the exponential phase of growth, and (iii) cultured at a lower temperature. Rough strains were more hydrophobic than smooth strains. Of the various surface components examined, the outer membrane proteins were conspicuously hydrophobic. The cell-bound hemagglutinating activity of V. cholerae strains was increased when these strains were cultured in synthetic medium and harvested at the stationary phase of growth. This property was unaffected by the growth temperature. Only D-mannose, at a high concentration, inhibited hemagglutination of 80% of the isolates examined. L-Fucose did not inhibit the hemagglutinating activity. V. cholerae strains adhered strongly to the anion-exchange matrix DEAE-cellulose. The surface charge density was accentuated when these strains were grown in synthetic medium. These results suggest that the V. cholerae surface contains both specific (hemagglutinating) and nonspecific (hydrophobic and ionic) factors which may influence its eventual adherence to the host cell surface.