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Biomedical subjects

N Kahn

Publications and source records attributed to N Kahn.

At least 19 recordsLinked to original sources
PubMed1990

Nucleoside inhibitors of rhodopsin kinase.

The specificity of the ATP-binding site of rhodopsin kinase was studied with adenosine analogues that are competitive inhibitors. Systematic changes in the ribose ring (position 5') and the purine ring (positions 2, 6, 7, 8, and 9) and determination of the inhibitory properties of these analogues lead to the following conclusions: (1) The N6 nitrogen in the purine ring is essential for binding at the active site, which may explain the marked preference for ATP rather than GTP as substrate. (2) The configuration of the sugar moiety is critical for the binding. (3) Positions 2, 3, and 8 of the purine ring, as well as the polyphosphate chain, play a minor role in substrate recognition by rhodopsin kinase. (4) ATP gamma S is a good substrate for rhodopsin kinase (thus rhodopsin phosphorothioate, a phosphatase-resistant product, can be formed in order to study the role of phosphorylation in rod outer segments). Pyrrolopyrimidine derivatives are very potent inhibitors of rhodopsin kinase. The Ki of one of these, sangivamycin, is 180 nM. Sangivamycin in solution assumes the anti conformation, as determined by nuclear Overhauser measurement. These measurements show that the most potent inhibitors of rhodopsin kinase, sangivamycin and toyocamycin, occur in solution preferentially in the anti conformation. Many nucleotides and nucleosides tested that are not inhibitors are syn, and many that are inhibitors form a mixture of syn and anti. The hypothesis that inhibitors may have a conformation intermediate between syn and anti was strengthened by testing a cyclic nucleoside locked in an anti conformation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1990

Behavioral and pharmacologic management of patients with Alzheimer's disease.

While as yet there are no proven effective primary treatments for Alzheimer's disease, physicians play a critical role in the evaluation and long-term supportive care of these patients and their families. The physician also plays a pivotal role in helping the patient make management decisions regarding their loved one such as organizing the process of nursing home placement in the more advanced phases of the illness. In addition, physicians provide a focal point for triage community support resources, such as the Alzheimer's Association. When necessary, the judicious and conservative use of psychopharmacologic agents can serve to partially diminish the pervasive behavioral complications of this illness.

Aged↗
PubMed1987

Hazards of 'deleading' homes of children with lead poisoning.

"Deleading" the homes of children with lead poisoning is a necessary step to terminate the child's exposure to lead. Lead poisoning as a result of lead exposure during the process of deleading has occurred in deleading workers but has not been well documented among children whose homes are deleaded. We treated four children with classes I through III lead poisoning (range of blood lead [Pb-B] level, 1.6 to 2.75 mumol/L [33 to 57 micrograms/dL]) who had significant elevation of their Pb-B levels (range, peak 4.34 to 6.27 mumol/L [90 to 130 micrograms/dL]) following deleading of their homes. The methods used for deleading included scraping, sanding, and burning of the paint. Symptoms included irritability (n = 3) and vomiting (n = 1). The elevation of the Pb-B levels was detected early, allowing prompt chelation therapy. Because exacerbation of lead poisoning may occur in children following deleading of their homes, safer approaches of deleading should be determined.

Chelating Agents↗
PubMed1987

Postpartum psychosis induced by bromocriptine.

Two multigravida patients with no prior psychiatric history were seen with postpartum psychosis, having received bromocriptine for inhibition of lactation. Bromocriptine given in high doses has been associated with psychosis in patients receiving the drug for Parkinson's disease. These cases demonstrate that bromocriptine may cause psychosis even when given in low doses.

Adult↗
PubMed1977

Pharmacology national board examinations: factors that may influence performance.

Data from a survey of pharmacology courses in 60 dental schools were used to determine whether certain teaching variables affect performance in pharmacology National Board examinations. In addition, three-year class-averaged pharmacology scores and, rarely, one-year averaged scores were correlated with several admissions variables. While correlations between some admissions variables and pharmacology scores were quite good, the averaged pharmacology scores were not powerfully affected by course length, placement of the course in the curriculum, length of the curriculum, or the presence of a dentally trained pharmacologist in the department. It is suggested that other factors, related to the student and his capabilities, influence performance on National Boards. Dental pharmacology courses should be designed to given students the best possible exposure to an important basic science, not to make them perform well on National Boards, because student performance on National Boards may be independent of the nature of the didactic courses.

Certification↗
PubMed1976

Group work with emphysema patients.

This article describes group work services to ambulatory emphysema patients in a community hospital. The group is viewed as an essential component in the treatment of patients with a chronically disabling illness. These patients experience devastating changes in their lives in the community, in the world of work, and in their families. Physical and respiratory therapy and medication comprise the medical treatment, group work provides the peer support necessary for coping with the disease in a way as to assist with maintaining health and improving the quality of life.

Adaptation, Psychological↗
PubMed1976

The teaching of pharmacology in dental schools in the United States and Canada.

The teaching of pharmacology in dental schools in the United States and Canada was studied through an analysis of information provided by course directors of 58 schools. The study focuses on the number of courses taught and their position in the curriculum, the faculty and their professional qualifications, the length and content of courses, the textbooks used, methods of teaching, and examinations and other criteria for grading.

Canada↗
PubMed1976

A home-treatment program for the cerebral-palsied child.

The process and results of a two-month intensive home-treatment program for a two-year-old athetoid cerebral-palsied boy are described in this article. The exploratory program was designed to develop methods and procedures for the mother to use to promote the child's normal postural tone and movement during daily handling and care. The foundation for the intervention program was based on a collation of the child's history, a one-day assessment of the child's activities and time schedule in the home, and a physical evaluation. Postevaluation identified changes in the child's feeding, playing, and sleep patterns that suggested more normal movement and muscle tone. Also, the mother established new physical handling patterns and the therapist gained skill and a new awareness in home intervention programs.

Cerebral Palsy↗
PubMed1967

Centrally evoked sympathetic discharge: a functional study of medullary vasomotor areas.

1. The medulla oblongata was stimulated electrically in decerebrate cats following bilateral vagotomy. Changes in splanchnic nerve discharge evoked by stimulation of pressor and depressor areas in the medulla are correlated with changes in arterial pressure. An interaction of baroreceptor afferents with the efferent sympathetic system at the level of the medulla and/or spinal cord is demonstrated. Evidence is presented which suggests that it is possible to alter activity selectively in a given division (splanchnic) of the sympathetic outflow.2. Evoked responses were categorized as follows:(a) Sustained splanchnic activation; an immediate increase in total splanchnic activity occurred with only a small, gradual decline in activity during the stimulation period. Mild stimulation (150-200 muA) raised systolic pressure by 60-80 mm Hg and stronger stimulation (300-400 muA) increased pressure by 100-150 mm Hg. When comparable pressor responses were elicited from points on either side of the mid line, splanchnic excitation was greater with homolateral stimulation (left side).(b) Unsustained splanchnic activation; an immediate increase in activity occurred which declined sharply as systolic pressure rose by 60-100 mm Hg during stimulation. Such a decline was attributed to the influence of baroreceptor afferents. Thus, if previous carotid occlusion was maintained during stimulation, the decline in activity was minimized although the pressor response increased. It is suggested that the structures yielding unsustained responses differ from those yielding sustained responses in their functional relation with the baroreceptor afferents.(c) Reduced splanchnic discharge during direct medullary stimulation; a partial or complete inhibition of splanchnic activity was obtained, which was sometimes accompanied by a 20-40 mm Hg reduction in systolic pressure. However, the direction and magnitude of the systemic pressure change were not as consistently related to the splanchnic response as they were during activation. Even if splanchnic efferent activity were elevated by carotid occlusion, stimulation still reduced discharge.

Animals↗