Biomedical subjects
Publications and source records attributed to M Gross.
We describe a multi-factorial model for the diagnosis of speech development disorders. The model serves as the basis for an individually designed course of therapy covering all aspects of the disorder. The separate diagnostic steps are in accordance with a classification of speech development disorders based on aetiology and pathology.
40 children were treated for progressive sensorineural hearing loss with infusions of prednisolone and pentoxifylline. After this treatment pure tone audiometric findings showed improved auditory thresholds in 52.5%. The results are discussed dependent on aetiologic findings.
The red blood cell (RBC) content of urine specimens was determined both by direct counts by a hemocytometer and by the number of RBCs per high-power field (HPF) in the sediment by routine urine analysis. The sensitivity of a finding of 1 to 3 and 2 to 4 RBCs/HPF in detecting greater than or equal to 2,000 RBCs/ml unspun urine was 63% (73/116) and 54% (63/116), respectively. There was a wide range of values of RBCs/ml determined by direct counts for each degree of microscopic hematuria as defined by the HPF method. We conclude that examination of the urinary sediment by the HPF method is not sufficiently sensitive to be used as a screening test for the detection of microhematuria in asymptomatic subjects.
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The visual acuity of 38 helicopter pilots experiencing serious air accidents was compared to that of a control group of 72 pilots, matched for age, aircraft, and hours of flight. Decrease in visual acuity was divided into two groups: 1) minor decreases in vision up to 20/25 (not requiring corrective lenses); and 2) visual acuity of 20/30 or less with correction to 20/20. Minor decreases in visual acuity were found in 23.7% (9/38) of those in the accident group compared to 25.0% (18/72) in the control group. There were more pilots in the control group who needed corrective lenses (12.5% (18/72) versus 2.8% (1/38), p less than 0.07). We conclude that helicopter pilots with corrective lenses or minor uncorrected decreases in visual acuity are not at increased risk for serious air accidents.
During 1981-1984, a total of 52 airpersonnel had 24-h continuous ambulatory electrocardiographic (ECG) monitoring at the Israel Air Force Aeromedical Center because of an incidental finding of a first or second degree atrio-ventricular block on a resting 12-lead ECG. There were 230 other airpersonnel without AV block on the resting ECG monitored during the same period. Altogether 17 cases of second degree Mobitz type I (Wenckebach) block were identified. Mobitz type I was detected on Holter monitoring in 2 (0.9%) of the 230 cases with a normal PR interval on the resting ECG, in 6 (15.4%) of 39 cases with a PR interval of 0.22-0.25 s, in 5 (55.5%) of 9 cases with a PR interval of 0.26 s or more, and in all 4 cases with Mobitz type I on the resting ECG. It is concluded that the PR interval on the resting ECG may be useful in predicting an intermittent Mobitz type I AV block on Holter monitoring.
Pilots were examined in order to determine whether the cumulative incidence or point prevalence of asymptomatic microscopic hematuria is associated with air duty. The cumulative incidence of recurrent microscopic hematuria over a 12-15-year period was 11.3%(17/151) in fighter pilots, 10.0%(8/80) in helicopter pilots, and 13.8% (11/80) in transport pilots. Similarly, the point prevalence of microscopic hematuria in those who had flown the day prior to the urinalysis was no higher than found in the control group. We conclude that air duty does not cause microscopic hematuria either chronically or during the day after the stress of air flight.
There were 21 pilots followed for 12-131 months in order to determine the natural history of spondylolithesis (SLL). Of these 21, 16 had follow-up X-ray examinations, and only 1 was found with significant progression of the posterior vertebral displacement. Of the 12 pilots with SLL and low back pain (LBP), 4 had recurrent single episodes of acute LBP, but all remained active and continued to fly over the follow-up period. None of the 9 pilots who had SLL discovered on routine X-ray examination developed LBP over the follow-up period. We conclude that pilots with SLL can continue to fly with minimal risk of morbidity and loss of flight time.
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The records of 719 male air force personnel, aged 18-30 in 1968, were searched for the results of the systolic blood pressure (SBP), and height and weight examinations at entry in 1968 and after 12-15 years follow-up. The body mass index (BMI = weight/height2) was calculated and an elevated value was defined as one in the upper quintile. An elevated blood pressure, defined as an SBP greater than or equal to 140 mm Hg, was found on follow-up in 4.7% of the entire cohort, in 6.0% (4/67) of those with an elevated SBP and a normal BMI at entry, in 10.2% (12/117) of those with a normal SBP and an elevated BMI at entry, and in 20.0% (7/35) of those with both elevated BMI and SBP greater than or equal to 140 mm Hg at entry. Of those with a normal SBP and BMI at entry, 2.2% (11/500) had an elevated SBP on follow-up. We conclude that BMI in young men can predict SBP 12-15 years later, and that this predictive value is at least as high as that of the resting blood pressure.
Tumours originating from the ceruminous glands can be classified into five types: adenomas, adenocarcinomas, adenoid-cystic carcinomas, pleomorphic adenomas and mucoepidermoid carcinomas. The diagnosis is based on histological findings and can be quite difficult if the tumour status has to be determined. Classification into one of the five types of tumours may be facilitated at times by studying the clinical pattern. Three case reports are quoted as examples to illustrate that neoplasias originating from the ceruminous glands can assume considerable proportions and must be considered in differential diagnosis when assessing space-occupying growths in the soft tissue of the neck. Whereas prognosis of adenomas and pleomorphic adenomas can be considered to be good, it must be regarded as likely to be infaust in the case of adenocarcinomas, adenoid-cystic carcinomas and mucoepidermoid carcinomas. The use of cytostatics resulted in a marked reduction of the tumour in one of the described cases of adenocarcinoma.
The records of 726 male air force personnel aged 18 to 34 years in 1968 were searched for the results of examination of the systolic blood pressure (SBP) in 1968 and during the following 15 years ending in 1983. An elevated recent blood pressure (BP), defined as an SBP greater than or equal to 140 mm Hg on two or more of the last three follow-up examinations, done 13, 14, and 15 years after entry, was found in 3.2% of the cohort. An elevated recent BP was found in 12% of those with an SBP greater than or equal to 140 mm Hg on the first examination, in 31.7% (13 of 41 individuals) of those with an SBP greater than or equal to 140 mm Hg on two or more of the three initial annual examinations, and in 46.2% (6 of 13 men) of those with an SBP greater than or equal to 140 mm Hg on all three initial examinations. It is concluded that three annual determinations of SBP are better predictors of elevated SBP than a single causal BP measurement on entry. Still, their predictive value remains limited; 49% of those with an SBP greater than or equal to 140 mm Hg on two or more of the three initial annual examinations had a normal SBP on all of the last three annual examinations.
This cross-sectional study revealed a prevalence of reduced calcaneal bone density in a population of 49 chronic continuing care patients with restricted mobility. Calcaneal bone density was measured using the Compton gamma ray scattering technique, which permits examination of trabecular bone. Predicted densities were determined from the ages and weights of the subjects. Descriptive factors such as gender, diagnosis, duration of the condition, and muscle tone were correlated with bone density. Twenty-eight patients (57%) had indications of reduced calcaneal bone density. None of the descriptive factors was associated with the variability in bone density ratio (forward stepwise regression analysis, p = NS). The reduced calcaneal density found in these patients with restricted mobility is probably a result of their not bearing weight and the inevitable severe reduction in their physical activity.
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A 55 years old patient suffering from exercise-induced muscle pain and stiffness due to primary myoadenylate deaminase deficiency has been successfully treated with D-ribose since 1984: single doses of 4 grams administered at the beginning of exercise prevented the symptoms completely; on continuation of exercise this dose had to be repeated all 10-30 min. Total doses of 50-60 g per day were tolerated without side-effects.
Inhibition of polypeptide chain initiation in rabbit reticulocyte lysate by phosphorylation of eukaryotic initiation factor-2(alpha) results, secondarily, in the enzymatic deacylation of Met-tRNAf on the 48 S initiation complexes that accumulate. We have prepared an antibody to a highly purified preparation of the major Met-tRNAf deacylase activity on rabbit reticulocyte ribosomes, termed deacylase II. Antibody, but not similarly purified normal IgG, completely neutralizes the activity of Met-tRNAf deacylase II and has no effect on Met-tRNAf deacylase I, a separate, minor, reticulocyte activity with the same substrate specificity but very different physical and enzymatic properties, strongly suggesting that deacylase I and II are distinct proteins. We partially purified Met-tRNAf deacylase activities from rabbit liver, myocardium and bone marrow ribosomes and found them to be similar to each other and to reticulocyte deacylase I in their enzymatic properties and insensitivity to anti-deacylase II, suggesting that deacylase I may be a general form of this enzyme, present in many cells, while deacylase II may be induced specifically during erythroid differentiation. Addition of the antibody to reticulocyte lysate incubated in the absence of hemin or presence of hemin plus 0.1 microgram/ml poly(I X C) did not reverse the inhibition of protein synthesis but did reduce the rate of turnover/utilization of Met-tRNAf and increase the level of Met-tRNAf bound to 48 S initiation complexes, demonstrating that the deacylase does not directly inhibit protein synthesis under these conditions but does mediate the deacylation, loss, and thus greater than expected turnover of Met-tRNAf in the 48 S complexes that accumulate.
Mammary glands are target tissues for 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). We have examined a mouse mammary tumor cell line (GR) for receptors of 1,25(OH)2D3 and have examined alterations in the growth and morphology of these cells in response to 1,25(OH)2D3. GR cells contain a high affinity (Kd approximately 10(-11)), low-capacity receptor with a high specificity for 1,25(OH)2D3. The 1,25(OH)2D3 receptor in GR cells has a sedimentation coefficient of 3.5 and elutes from DEAE cellulose columns with approximately 0.15 M KCl. These properties of the receptor are similar to those reported for other 1,25(OH)2D3 receptors. 1,25(OH)2D3 is internalized by GR cells in situ and specifically bound 1,25(OH)2D3 is found predominantly, if not entirely, in the nucleus as determined by cell fractionation and autoradiographic techniques. The incubation of GR cells in culture for 7 days with 1,25(OH)2D3 markedly alters cell growth. Cell growth is retarded in a dose-dependent manner; physiologic concentrations (10(-10) M) of 1,25(OH)2D3 retard cell growth by approximately 50%. In addition, GR cells incubated with 10(-9) to 10(-8) M 1,25(OH)2D3 undergo marked morphological changes. The incubation of GR cells with other vitamin D metabolites such as 25-hydroxyvitamin D3 (25(OH)D3) at a concentration of 10(-9) M does not significantly alter cell growth or morphology. The presence of high affinity receptors for 1,25(OH)2D3, the specific internalization of 1,25(OH)2D3 predominantly into the nuclei, and the significant effects of physiological concentrations of 1,25(OH)2D3 on cell growth suggest a direct, specific, nuclear effect of 1,25(OH)2D3 on GR cells. The mouse mammary tumor model might be useful in examining the effect of 1,25(OH)2D3 on tumor formation.
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