Biomedical subjects

J I Perlman

Publications and source records attributed to J I Perlman.

22 records · Page 2Linked to original sources

PubMed1984

Cycloheptatrienylidene analog of 11-cis retinal. Formation of pigment in photoreceptor membranes.

In biochemical and electrophysiologic studies employing the bullfrog (Rana catesbeiana) and the rat, the authors examined the interaction of opsin and an 11-cis-locked analog of retinal. In previously bleached preparations of bullfrog receptor outer segments (ROS) and isolated retinas, incubation with the aldehyde form (I) of the analog leads to the appearance of a pigment that is degraded slowly by hydroxylamine but is relatively resistant to photolysis. In the ROS preparation, the analog pigment (lambda max of difference spectrum congruent to 497 nm) also forms on incubation with NADP+ and the alcohol form (II) of the analog. In vitamin A deprived rats possessing only approximately 45% of the normal complement of rhodopsin, intraperitoneal injection of II leads within 1 day to the appearance of the analog pigment in the photoreceptors, at levels representing a major fraction of the opsin initially available for pigment formation. Formation of the analog pigment appears to have no significant effect on the sensitivity of electroretinographic b-wave responses recorded from the rat eye; furthermore, administration of II appears to suppress the sensitizing activity of all-trans retinol injected 1 day later. The data are discussed in relation to other studies examining chromophore-opsin interactions and electrophysiologic changes associated with the formation of rhodopsin in situ.

Animals↗

PubMed1982

Utilization of retinoids in the bullfrog retina.

The capacity to generate 11-cis retinal from retinoids arising naturally in the eye was examined in the retina of the bullfrog, Rana catesbeiana. Retinoids, co-suspended with phosphatidylcholine, were applied topically to the photoreceptor surface of the isolated retina after substantial bleaching of the native visual pigment. The increase in photoreceptor sensitivity associated with the formation of rhodopsin, used as an assay for the appearance of 11-cis retinal in the receptors, was analyzed by extracellular measurement of the photoreceptor potential; in separate experiments using the isolated retina or receptor outer segment preparations, the formation of rhodopsin was measured spectrophotometrically. Treatments with the 11-cis isomers of retinal and retinol induced significant increases in both the rhodopsin content and photic sensitivity of previously bleached receptors. The all-trans isomers of retinyl palmitate, retinol, and retinal, as well as the 11-cis isomer of retinyl palmitate, were inactive by both the electrophysiological and spectrophotometric criteria for the generation of rhodopsin. Treatment with any one of the "inactive" retinoids did not abolish the capacity of subsequently applied 11-cis retinal or 11-cis retinol to promote the formation of rhodopsin. The data are discussed in relation to the interconversions of retinoids ("visual cycle of vitamin A") thought to mediate the regeneration of rhodopsin in vivo after extensive bleaching.

Animals↗

PubMedDate not supplied

Co-prescribing of medications used to treat obstructive lung disease, congestive heart failure and depression among users of topical beta blockers: estimates from three US Veterans Affairs Medical Centers.

PURPOSE: To estimate the frequency of co-prescribing of medications used to treat obstructive lung disease, congestive heart failure, and depression among US armed service veterans for whom topical beta blockers (TBB) have been prescribed. METHODS: Prescription data from the computerized medical record systems of three US Veterans Affairs Medical Centers were obtained during Fall 1999 to identify patients for whom active prescriptions existed for TBB and/or drugs commonly used to treat obstructive lung disease, congestive heart failure, and depression. RESULTS: Among TBB users, the estimated co-prescribing rate of medications used to treat obstructive lung disease is in the range of 7.8-9.7%, of medications used to treat congestive heart failure is in the range of 4.3-25.1%, and of medications used to treat depression is in the range of 8.8-11.7%. The total number of TBB users with a concurrent prescription for one or more of the conditions studied was in the range of 30.2-45.7%. CONCLUSIONS: Since TBB may cause systemic side-effects and thus potentially cause exacerbations of selected chronic conditions, it is important for researchers and prescribers to be aware of the frequency with which their patients with glaucoma may have other concomitant conditions.

Administration, Topical↗

PubMedDate not supplied

Oncocytic adenocarcinoma of the lacrimal sac: report of a case with paranasal sinus and orbital extension.

A 92-year-old man has had multiple recurrent oncocytic tumors involving the right paranasal sinuses and orbit. A benign oncocytoma that arose from the right lacrimal sac was initially diagnosed at age 80 years. The tumor recurred at 3 and 7 years after initial resection. There was greater histologic atypia in the first recurrent tumor, which extended into the right paranasal sinuses. The second recurrence had zones on oncocytic adenocarcinoma exhibiting prominent nuclear atypia and mitotic activity; this tumor massively invaded the right paranasal sinuses and orbit. We describe the clinical and pathologic features of this rare case.

Adenocarcinoma↗