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Biomedical subjects

M Gross

Publications and source records attributed to M Gross.

At least 487 records · Page 27Linked to original sources
PubMed1986

Excimer laser surgery of the cornea: qualitative and quantitative aspects of photoablation according to the energy density.

Using an excimer laser working in the far ultraviolet and cutting fresh corneas of human cadaver eyes, we were able to demonstrate that there is an ideal fluence (joule/cm2/pulse) that allows a maximum tissue ablation depth per shot. Above the threshold of 1 J/cm2/pulse the depth of tissue ablated does not increase and both thermal and mechanical damage appears at the cut edges.

Cornea↗
PubMed1986

The effect of age on the prevalence of asymptomatic microscopic hematuria.

The medical files of a sample of men who had been followed by annual examinations from 1968 through 1978 were selected, using a random number sequence from the records of the Israel Air Force. One group of 430 men, ages 21-23 at entry, and a second group of 264 men, ages 25-28 at entry, were studied. The results of the urinalysis at entry and after ten years of follow-up were recorded. The point prevalence of all degrees of microhematuria increased significantly with age in both groups. One to three or more red blood cells (RBCs) per high-power field (HPF) were found in 3.5% of the subjects ages 21-23 at entry and in 14.2% in the same subjects ten years later (P = 0.001). Similarly, one to three or more RBCs per HPF were found in 4.9% of men ages 25-28 at entry and in 11.7% of the same subjects ten years later (P = 0.001). The authors conclude that age needs to be taken into consideration in drawing the line between physiologic and pathologic microhematuria.

Adult↗
PubMed1986

Isolation, characterization and in vitro cultivation of subfractions of neonatal mouse keratinocytes: effects of phorbol esters.

Using discontinuous Percoll density gradient centrifugation, keratinocytes from neonatal mouse skin were separated into four fractions. The fractions were characterized by light microscopy, by indirect immunofluorescence using lectins (Bandeira simplicifolia and Ulex europaeus) or an antibody against bullous pemphigoid antigen, and by electrophoretic analysis of the keratin polypeptide patterns. Two fractions, F1 and F2, were identified as being derived from suprabasal layers and two fractions, F3 and F4, as originating from the basal cell layer. F3 and F4 cells could be cultivated on plastic substratum in the presence of 4 X minimum essential medium, 10% fetal calf serum at 34 degrees C with plating efficiencies of 80-85%. DNA labeling of cultures of F3 and F4 cells indicated that basal cells in fractions F3 and F4 exhibited different growth behaviour in culture. Confluent cultures of F3 and F4 cells responded to phorbol esters by increased DNA synthesis. This result contradicts the in vivo situation where neonatal mouse skin is resistant to the irritant and mitogenic effects of phorbol esters. The mitogenic effect of 12-O-tetradecanoylphorbol-13-acetate on F3 cells is not mediated by endogenous prostaglandin formation.

Animals↗
PubMed1986

Spontaneous pneumothorax and mitral valve prolapse.

We searched for mitral valve prolapse in patients with spontaneous pneumothorax to test the hypothesis that both may be part of a common disorder of connective tissue. Echocardiographic mitral valve prolapse was found in 11 (50 percent) of 22 patients who had suffered spontaneous pneumothorax compared to four (10 percent) of 40 age-matched control subjects (p less than 0.01). The body mass index (BMI) (weight/height2) was lower (p less than 0.001) in the group with pneumothorax; in five patients who were the thinnest in the study (BMI less than 2 standard deviations lower than mean normal value), mitral valve prolapse was present in four. The finding of a strong association of spontaneous pneumothorax with mitral valve prolapse, especially in subjects with an abnormal body build, suggests that in many patients, spontaneous pneumothorax may be a manifestation of a systemic abnormality of connective tissue.

Adult↗
PubMed1986

Low back pain in pilots.

A questionnaire on low back pain (LBP) was administered to 373 fighter pilots, 165 transport pilots, and 264 helicopter pilots. Helicopter pilots had more pain during flight than did fighter or transport pilots (34.5%, 12.9%, and 5.1%, respectively). A history of LBP temporally unassociated with flight was found in 26.5% of helicopter pilots, 31.5% of transport pilots and 25.2% of fighter pilots. We conclude that, despite the pain experienced by helicopter pilots in flight, they are not at increased risk for LBP unassociated with flight.

Adult↗
PubMed1986

The physiology of the vitamin D endocrine system.

It is clear that the vitamin D endocrine system plays a central role in the maintenance of calcium and phosphate homeostasis. It may be involved in the cellular differentiation and growth of various cells. Investigation of these properties in the future is likely to yield interesting information concerning the biology of this sterol hormone.

Animals↗
PubMed1986

Positron emission tomography.

PET is a unique tool for the direct in vivo evaluation of physiologic processes within discrete areas of the brain. Thus far, its application to the study of schizophrenia has served to confirm the subtleties of this illness. However, PET does promise to increase our knowledge of the neurochemical anatomy of the normal and abnormal mind with respect to goal-directed behavior.

Basal Ganglia↗
PubMed1986

Prevalence of postural T wave changes in mitral valve prolapse: a quantitative study.

The abnormal ECG T wave changes associated with mitral valve prolapse (MVP) were studied and quantitated in a group of 36 asymptomatic individuals with MVP and compared with a 27-member control group. The mean frontal plane T wave axis shifted markedly leftward on standing, with T wave axis less than or equal to 0 degrees in 16 (44%) of the subjects with MVP vs. only 2 (7.4%) of the control group, while the QRS-T angle widened to more than 60 degrees in 18 (50%) of those with MVP. Marked left axis deviation of the T wave on standing with T wave axis less than or equal to -30 degrees was found only in subjects with MVP, and their QTc interval was longer, P less than 0.05. In 11 subjects with mitral valve bowing or rounding on the echocardiogram (i.e., less than 2 mm posterior mitral valve displacement), intermediate grades of T wave axis shifts were seen.

Adolescent↗
PubMed1986

Central serous retinopathy (choroidopathy) in pilots.

The clinical charts of pilots in the Israeli Airforce were reviewed retrospectively for evidence of central serous retinopathy (CSR). There were 14 pilots with documented CSR identified, with an incidence of 1.3 per 1000 per year. Of 6 pilots who had recurrent attacks, 5 had a decrease of visual acuity during the initial attack to at least 20/30 in the affected eye. On the other hand, in those with visual acuity no worse than 20/25, only 1 of 7 had recurrent attacks (p less than 0.05). We conclude that CSR is a common condition in pilots, and that visual acuity during the initial attack can predict those who will have recurrent disease.

Adult↗