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Biomedical subjects

D Salem

Publications and source records attributed to D Salem.

30 records · Page 2Linked to original sources
PubMed1989

External cardiac programmed stimulation for noninvasive termination of sustained supraventricular and ventricular tachycardia.

To examine the feasibility of using a noninvasive temporary pacemaker for termination of well-tolerated supraventricular (SVT) and ventricular tachycardia (VT), a standard external demand pacemaker was modified to allow stimulation with single or multiple extrastimuli and overdrive pacing. To evaluate the efficacy, safety and tolerance of external cardiac programmed stimulation, a standard arrhythmia termination protocol was used in 223 tachycardias in 22 patients. The technique of external cardiac programmed stimulation was used in 209 episodes of SVT in 13 patients. It terminated 95% of the episodes with success in 19 of 20 episodes of atrioventricular nodal reentrant tachycardia and 179 of 189 episodes of atrioventricular reciprocating tachycardia. Of 198 episodes of SVT terminated by the technique 168 (85%) were terminated by a single extrastimulus and 28 (14%) by double extrastimuli. Only 2 episodes of SVT required overdrive pacing for termination. External cardiac programmed stimulation did not result in atrial fibrillation or arrhythmia acceleration. Of 14 episodes of sustained monomorphic VT 5 were terminated by external cardiac programmed stimulation. One tachycardia was terminated by a single extrastimulus, 1 by double extrastimuli and 3 by overdrive pacing. Arrhythmia acceleration occurred once and was terminated by endocardial pacing. On 27 separate occasions patient evaluation of maximal discomfort included 4 ratings of mild, 10 of moderate, 11 of severe and 2 of intolerable discomfort. External cardiac programmed stimulation is effective and safe in patients with well-tolerated sustained supraventricular or ventricular arrhythmias.

Adult↗
PubMed1986

Apolipoprotein A-I gene polymorphism associated with premature coronary artery disease and familial hypoalphalipoproteinemia.

Decreased plasma high-density-lipoprotein (HDL) cholesterol and apolipoprotein A-I levels have been associated with premature coronary artery disease. We identified a PstI restriction-endonuclease site flanking the human apolipoprotein A-I gene at its 3' end that is polymorphic. The absence and presence of this site, as determined by genomic blotting analysis of PstI-digested chromosomal DNA with the use of an apolipoprotein A-I gene probe, were associated with 3.3-kb and 2.2-kb hybridization bands, respectively. The 3.3-kb band appeared in 4.1 percent of 123 randomly selected control subjects and in 3.3 percent of 30 subjects with no angiographic evidence of coronary artery disease. In contrast, among 88 patients who had severe coronary disease before the age of 60, as documented by angiography, the 3.3-kb band occurred in 32 percent (P less than 0.0001). It was also found in 8 of 12 index cases (P less than 0.0001) of kindreds with familial hypoalphalipoproteinemia. In the two patient groups, the allele frequencies of the site that produced the 3.3-kb band were 17 and 42 percent, respectively, as compared with an allele frequency of only 2 percent in the control populations. Within kindreds with familial hypoalphalipoproteinemia and among first-degree relatives of patients with coronary artery disease, the 3.3-kb band was associated with decreased HDL cholesterol levels. Among all patients with coronary artery disease, 58 percent had HDL cholesterol levels below the 10th percentile of normal values; however, this frequency increased to 73 percent when patients with the 3.3-kb band were considered. These findings indicate that the polymorphism in the region between the apolipoprotein A-I and apolipoprotein C-III genes may be a useful marker for the risk of premature coronary artery disease and familial hypoalphalipoproteinemia.

Age Factors↗
PubMed1985

Visual acuity screening of children 6 months to 3 years of age.

The operant preferential looking (OPL) procedure allows a behavioral estimate of visual acuity to be obtained from children 6 mo to 3 yr of age. In clinical settings, there is often too little time available to obtain an acuity estimate with the standard OPL procedure. The goal of this study was to identify specific spatial frequencies, termed diagnostic grating frequencies, that could enable the OPL technique to be used as a screening procedure under conditions where completion of acuity estimation was not possible. One hundred eighty presumptively normal children, 6, 12, 18, 24, 30, and 36 mo of age, were each tested with up to 20 trials of a potential diagnostic grating frequency to determine the highest spatial frequency grating that could be resolved by 90% of children at each age. For all ages except 18 mo, there existed a spatial frequency that produced uniformly high OPL performance within the age group; this spatial frequency was separated by one-half to one octave from a higher spatial frequency that more than 30% of children at that age failed to detect. These results suggest that at all ages except 18 mo, it should be possible to use the OPL procedure as a vision screening tool by testing individual children with the diagnostic grating frequency appropriate for their age.

Child, Preschool↗
PubMed1983

Translumbar coronary arteriography.

Selective coronary angiography, using a catheter sheath placed across the lumbar region and into the abdominal aorta, has been performed for a patient with lack of other arterial access due to severe occlusive atherosclerosis in the abdominal aorta and innominate and left subclavian arteries. This approach is quick and facile, but care must be taken to prevent possible bleeding complications.

Aorta, Abdominal↗
PubMed1983

SPECT resolution and uniformity improvements by noncircular orbit.

A noncircular orbit implemented by a combination of rotational and translational motions in single photon emission computed tomography improves significantly the image resolution and uniformity. The former is realized by closer access of the detector to the object at each projection angle, and the latter by suppression of ring artifacts through the shifts in the distance between the centers of detector and object. This has been demonstrated by comparing the SPECT images for an elliptical orbit of 40 cm X 30 cm with the equivalent circular orbit of 40 cm diameter, performed by SPECT system with a high resolution collimator. Resolution FWHM improvements were 1.5-2.5 mm. Lesion contrast improved by a factor of 2.8 for a nonradioactive rod of 6 mm diam. In phantom images, the elliptical orbit showed better definition of lesion shape, sharper edge response, and clearly increased detectability. Translational motion reduced ring artifacts, particularly near the image center.

Models, Structural↗
PubMed1983

Visual acuity in infants--the effect of variations in stimulus luminance within the photopic range.

The forced-choice preferential looking technique was used to measure 2-month-old infants' visual acuity for black-and-white, square-wave gratings at six luminance values between -1.0 and 3.0 log cd/m2. The results indicated that the infants' acuity was relatively unaffected by variations in luminance above 1 log cd/m2, but was reduced by approximately 1 octave at a luminance of -0.8 log cd/m2. These results are in agreement with the results of adults tested in the same apparatus and with previously published data from adult subjects. Our results suggest that for infants, as for adults, variations in room illumination above 1.0 log cd/m2 have little effect on visual acuity.

Adult↗
PubMed1982

Immune regulatory abnormalities produced by procainamide.

The pathogenesis of procainamide-induced autoantibody production is unknown. To test the effect of procainamide on the immune system, we studied in vitro suppressor cell function and immunoglobulin G (IgG) secretion in 11 patients who developed autoantibodies while taking procainamide. The procainamide group was compared with patients with spontaneous systemic lupus erythematosus (n = 15) and a normal control population (n = 40). Impaired in vitro suppressor cell function was found in 11 of 14 patients with spontaneous systemic lupus erythematosus but in none of the patients taking procainamide. However, total in vitro IgG secretion was significantly increased in the procainamide group with regard to the control and systemic lupus erythematosus groups. There was a direct correlation between the circulating anti-SS DNA antibody titer and in vitro IgG secretion. Furthermore, T cells isolated from the procainamide-treated patients stimulated IgG secretion by normal allogeneic peripheral blood lymphocytes. The added T cells did not affect in vitro suppressor cell function. We postulate that autoantibody production in patients taking procainamide is due to enhanced helper T cell function and not to impaired suppression. However, the development of clinical disease requires the participation of additional genetic or immunologic factors.

Adolescent↗
PubMed1981

Cycloplegic refractions of premature infants.

Cyclopentolate refractions of 146 premature infants disclosed higher incidences of myopia and anisometropia than those reported for full-term infants. Also, more than 70% of the premature infants had I diopter or more of astigmatism; 83% of the astigmatism was against-the-rule. Infants with shorter gestational periods had more severe myopia and astigmatism. Infants born very prematurely should undergo follow-up refractions to determine whether they retain refractive errors large enough to interfere with visual function.

Age Factors↗
PubMed1980

Cycloplegic refractions in infants and young children.

We studied groups of normal infants and infants with amblyopia and esoropia to determine the incidence of infantile astigmatism. Under cycloplegia, 19% of normal infants had astigmatism; this was at least twice the incidence in adults, but less than one-hale that found by noncycloplegic refractions of infants. During the first three postnatal years the incidence of astigmatism and distributions of spherical equivalents and anisometropia did not distinguish normal patients from most of those with esotropia and amblyopia.

Adult↗
PubMedDate not supplied

Reproductive hazards of lead exposure among urban Egyptian men.

Fifty-five urban Egyptian males, aged 20-40, were assigned to two main groups to study the effects of their exposure to lead (Pb). Group I, infertile men (INF, n = 30), was divided into environmentally exposed (INF-E, n = 15) and environmentally and occupationally exposed (INF-EO, n = 15). A matching group (II) of fertile men (F, n = 25) was divided into fertile, environmentally exposed (F-E, n = 10), which was the control group, and fertile, environmentally and occupationally exposed (F-EO, n = 15). Semen parameters (i.e., count, morphology, motility, and volume), blood and semen Pb levels, and reproductive hormonal indices (i.e., serum testosterone, FSH, and LH) were measured in all subjects. Lead levels were always higher in blood than semen. Semen lead levels were significantly higher in all groups vs. the control (F-E) group. While no changes were observed in testosterone levels across groups, variable effects on LH and FSH levels were observed. Infertile-EO subjects showed a definite pattern of impaired semen parameters in comparison with infertile-E. No abnormalities were detected in hematologic, hepatic or renal function.

Adult↗
PubMedDate not supplied

Immunoglobulin E in serum and semen of infertile men.

Determination of IgE level in serum and semen of 92 men by an enzymatic immuno-assay method verified its presence in semen of most of them (92.3%) in much smaller amount than that present in serum (2.6%). IgE levels in serum and semen were significantly correlated. Serum levels were significantly higher in men with obstructive azoospermia, specially when associated with infection. Serum levels of IgE were higher in the fertile men, and in cases without infection as compared with those with prostatitis though this difference was not significant.

Adult↗