Search PubMed⌕ Search

Biomedical subjects

A L Berman

Publications and source records attributed to A L Berman.

At least 55 records · Page 3Linked to original sources
PubMed1984

[Heat denaturation of opsin in warm-blooded animals as a possible mechanism of light-induced retinal damage].

The rate of thermal denaturation of bovine and rat opsin in the photoreceptor membranes was studied within a wide temperature range (between 37 and 70 degrees C). It was found that the rate of thermal denaturation of opsin at a physiological temperature (37 degrees C) might be commensurable or even exceed the known rate of rhodopsin renewal produced by photoreceptor disk formation and shedding. Lipid peroxidation caused an increase in the rate of opsin denaturation at a physiological temperature. It is assumed that accumulation of denatured opsin in the photoreceptor membranes during raised illumination together with lipid peroxidation induction may be one of the mechanisms leading to vision deterioration under raised illumination.

Animals↗
PubMed1982

Suicide and the standard of care: optimal vs. acceptable.

The accepted standard of care in the treatment of suicidal patients is discussed from the perspectives of the law, malpractice insurance claims, the mental health professions, and the ideal. A review of decisions of professional liability in suits for wrongful death provides guidelines for what the court considers to be adequate care. Out of court settlements further connote accepted standards of reasonable care. Although attention to potential malpractice issues is necessary and appropriate, what appear to result are an acceptance of minimal standards and the practice of defensive care. It is argued that by demanding more optimal standards the consequent quality of care not only serves the patient best but provides the best legal protection as well.

Adult↗
PubMed1981

Light-induced changes of cyclic GMP content in frog retinal rod outer segments measured with rapid freezing and microdissection.

Cyclic GMP concentration was measured in the rod outer segments (ROS) of the isolated frog retinas. Retinas were quickly frozen in 0.5 s after the short light flash producing 90%-saturated late receptor potential (2,000 rhodopsins bleached per rod). ROS were obtained by microdissection, the cGMP levels were determined by radioimmunoassay method. No detectable changes in cGMP concentration was found in this stimulus condition. Dark-adapted ROS contained 46.3 +/- 2 pmol/mg. 3-s bright illumination (ca. 10(7) rhodopsins bleached per rod per second) led to approximately 30% drop in cGMP content. It is supposed that the main part of cGMP with the ROS is in the bound state and therefore fast light-induced changes in its minor free fraction may escape the detection.

Animals↗
PubMed1980

[Light-induced changes in activity of Na, K-ATPase from the retinal photoreceptors of vertebrates: possible mechanism].

The mechanism of light-induced changes in the activity of Na,K-ATPase from plasma membranes (PM) of photoreceptor cells was studied in vitro. Illumination resulted in inhibition of the ATPase activity and an increase of 18O exchange between water and Pi. The maximum light effect was revealed when the PM contained both the inner segments of the rods (RIS) and rod outer segments (ROS) of the photoreceptor cells. Lipid peroxidation stimulated by the FeSO4+ascorbate system induced a decrease of the ATPase activity. Antioxidants (ionol, Na2SeO3, vitamin E) prevented the effect of the lipid peroxidation products on NA,K-ATPase and the photoinduced changes of the enzyme activity. It is supposed that the photoinduced changes of the Na,K-ATPase activity in vitro are due to lipid peroxidation of photoreceptor PM.

Animals↗
PubMed1980

Diagnosis and treatment of childhood depression and self-destructive behavior.

This paper presents the results of a survey of Washington, DC, area physicians who confront the diagnosis and treatment of childhood depression and potential suicide. Questions addressed included the prevalence of childhood depression and self-destructive behavior, beliefs about such phenomena, criteria used in the diagnosis of depression, and treatment preferences for both childhood depression and self-destructive behavior. Nearly half of respondent physicians reported knowing of suicide attempts among patients under 14 years old; almost two thirds currently had a patient in treatment for depression with a mental health professional. Physicians subscribed to a number of traditional but false beliefs about young children's capacity for intentional self-destruction and the incidence of such acts being disguised as "accidents." Wide variation was observed in the symptoms physicians used to diagnose depression. In general, physicians attended most to overt behavior and family history, followed by psychological problems. Physicians need to be alert to the diagnostic significance of "masked" symptoms of depression, such as somatic complaints and acting-out, antisocial behaviors.

Adolescent↗
PubMed1979

Dyadic death: murder-suicide.

Twenty homicide-suicides, drawn from death records of three major eastern United States cities, were analyzed in comparison to prior studies and samples of homicide offenders and suicide victims. Results indicated a lower incidence for this event than reported previously and several distinguishing characteristics of the murderer who subsequently commits suicide. Two primary types, from the perspective of ego fusion, are discussed.

Adult↗
PubMed1978

[Protein inhibitor of the retinal cyclic nucleotide phosphodiesterase: its localization in the outer segment of a photoreceptor].

The content of a protein inhibitor of the cyclic nucleotides phosphodiesterase (PDE) in different retinal preparations as well as its distribution in the subfractions of rod outer segments (ROS) was studied. The content of protein inhibitor of PDE in different preparations of the retina was found to correlate with the rhodopsin content. The distribution of this protein over different ROS subfractions appeared to be exactly the same as that of rhodopsin, the content of protein inhibitor of PDE being more than a half of its content in the native ROS. The protein inhibitor of PDE could be easily washed out from the ROS fractions. It is concluded that the cattle protein inhibitor of PDE is localized in ROS, and is absent in the other retinal layers.

Animals↗
PubMed1978

[Modification of retinal photoreceptor membranes and Ca ion binding].

Calcium binding by modified photoreceptor membranes of cattle retina has been studied. Ca2+-binding the membranes significantly changes after C-phospholipase treatment, displaying the initial growth (less than 65% of lipid phosphorus removed) with subsequent decrease (more than 65% of phosphorus removed). Liposomes of the photoreceptor membranes lipids were found to bind more calcium than do the native photoreceptor membranes. Proteolytic enzymes (papaine, pronase) splitting some rhodopsin fragments do not affect the ability of the membrane to bind Ca2+. The increase of light-induced Ca-binding is observed only after the outer segments preincubation under conditions providing for rhodopsin phosphorylation. This effect was observed also after the splitting of the rhodopsin fragment by papaine. It is concluded that calcium binding in the photoreceptor membranes is mainly due to the phosphate groups of phospholipids.

Animals↗