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Biomedical subjects

E Friedman

Publications and source records attributed to E Friedman.

At least 577 records · Page 32Linked to original sources
PubMed1981

Monoamine oxidase activity and enzyme kinetics in three subpopulations of density-fractionated platelets in chronic paranoid schizophrenics.

Platelet monoamine oxidase (MAO) activity was studied in three subpopulations of density-fractionated platelets in 15 unmedicated chronic paranoid schizophrenic patients and contrasted with normal controls. No significant difference in MAO activity was found in any of the three platelet fractions in schizophrenics compared to controls. Enzyme kinetic studies performed on the intermediate-density platelet fraction demonstrated no significant differences in Vmax or Michaelis' constant (Km) between schizophrenics and controls, but showed that the higher platelet MAO activity reported in females compared to male is due to a significantly greater Vmax rather than altered Km. It is suggested that conflicting results reported in the literature regarding platelet MAO in schizophrenia are not related to the platelet subpopulations studied but are largely due to the selected patient populations.

Adult↗
PubMed1981

Isolated bladder neck obstruction of undetermined etiology (primary) in adult male: recognition and management.

Varying degrees of isolated bladder neck obstruction of undetermined etiology were identified with micturitional vesicourethral static pressure profiles. Our experience with the urodynamic studies in 15 patients suggests that isolated bladder neck obstruction is a real entity in young adult males. Our experience also suggests that pharmacologic success with alpha-adrenergic blockade of the dosage tolerated by the patients is inconsistent. Successful clinical results achieved with appropriate bladder neck surgery could be confirmed with uroflowmetry and detailed urodynamic studies during postoperative period.

Adult↗
PubMed1981

Presynaptic cholinergic mechanisms in brain of aged rats with memory impairments.

Presynaptic cholinergic mechanisms were investigated in various brain regions of aged Fisher 344 rats with documented 24 hr retention deficits measured in a single-trial passive avoidance tasks. Sodium-dependent high affinity choline uptake was found to be decreased by 22% in hippocampus of 23-26 month old animals as compared to 6 month old controls. Prior depolarization of hippocampal or cortical synaptosomes with K+ resulted in stimulation of choline uptake which was similar in aged rats and young controls. No age-related differences were observed either in hippocampal, cortical, striatal acetylcholine or choline concentrations, or in the activity of choline acetyltransferase in hippocampus. Synthesis of acetylcholine in hippocampal and cortical slices under basal conditions, as well as under K+-stimulated concentrations, did not differ in the two age groups examined. These neurochemical findings are consistent with an age-related decrease in hippocampal cholinergic neuronal activity without an actual loss in cholinergic neuron number. It is further suggested that this reduction in cholinergic neuronal activity may be related to the deficit in cognitive performance observed in aged Fisher rats.

Acetylcholine↗
PubMed1981

Profound effects of combining choline and piracetam on memory enhancement and cholinergic function in aged rats.

In an attempt to gain some insight into possible approaches to reducing age-related memory disturbances, aged Fischer 344 rats were administered either vehicle, choline, piracetam or a combination of choline or piracetam. Animals in each group were tested behaviorally for retention of a one trial passive avoidance task, and biochemically to determine changes in choline and acetylcholine levels in hippocampus, cortex and striatum. Previous research has shown that rats of this strain suffer severe age-related deficits on this passive avoidance task and that memory disturbances are at least partially responsible. Those subjects given only choline (100 mg/kg) did not differ on the behavioral task from control animals administered vehicle. Rats given piracetam (100 mg/kg) performed slightly better than control rats (p less than 0.05), but rats given the piracetam/choline combination (100 mg/kg of each) exhibited retention scores several times better than those given piracetam alone. In a second study, it was shown that twice the dose of piracetam (200 mg/kg) or choline (200 mg/kg) alone, still did not enhance retention nearly as well as when piracetam and choline (100 mg/kg of each) were administered together. Further, repeated administration (1 week) of the piracetam/choline combination was superior to acute injections. Regional determinations of choline and acetylcholine revealed interesting differences between treatments and brain area. Although choline administration raised choline content about 50% in striatum and cortex, changes in acetylcholine levels were much more subtle (only 6-10%). No significant changes following choline administration were observed in the hippocampus. However, piracetam alone markedly increased choline content in hippocampus (88%) and tended to decrease acetylcholine levels (19%). No measurable changes in striatum or cortex were observed following piracetam administration. The combination of choline and piracetam did not potentiate the effects seen with either drug alone, and in certain cases the effects were much less pronounced under the drug combination. These data are discussed as they relate to possible effects of choline and piracetam on cholinergic transmission and other neuronal function, and how these effects may reduce specific memory disturbances in aged subjects. The results of these studies demonstrate that the effects of combining choline and piracetam are quite different than those obtained with either drug alone and support the notion that in order to achieve substantial efficacy in aged subjects it may be necessary to reduce multiple, interactive neurochemical dysfunctions in the brain, or affect activity in more than one parameter of a deficient metabolic pathway.

Acetylcholine↗
PubMed1981

Involvement of hippocampal serotonergic activity in age-related changes in exploratory behavior.

The effect of aging on exploratory behavior was investigated in adult (5 month) and aged (28 month) CB6F1 mice. During the first 10 minutes of the test session, aged mice made fewer head dip responses and spent less time exploring the novel stimuli. Because the aged mice were observed to subsequently increase their duration of exploration, it was suggested that the initial differences in exploration reflected a suppression of exploratory behavior by the aged mice. Immediately after behavioral testing, mice were sacrificed and hippocampal serotonin (5HT) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations were determined. While 5HT concentrations were not found to be significantly altered with age, significant increases in 5-HIAA concentrations and in the ratio of 5-HIAA/5HT were observed in the aged mice. Further, the elevation in the 5-HIAA/5HT ratio was found to be significantly correlated with age-related differences in the duration, but not the frequency, of head dip responses. In view of this finding, it was suggested that alterations in serotonergic function with age may selectively affect specific aspects of an animal's response to novel stimuli.

Aging↗
PubMed1981

Vision training program for myopia management.

The use of vision training to stabilize myopia appears to be helpful for many patients, while remaining ineffective for others. The myopia management approach discussed here includes minimum use of full-powered concave corrective lenses, maximum use of convex training glasses, adherence to specific visual hygiene and visuobehavioral guidelines, and a short intense program of home and office visual training procedures aimed at developing more flexible accommodative convergence (CCA) and visuobehavioral responses.

Accommodation, Ocular↗
PubMed1981

Effects of conformationally restrained analogues of serotonin on its uptake and binding in rat brain.

Two series of serotonin analogues, in which the side chain amino group is constrained in the gauche or trans conformation, were utilized to study the preferred conformation of serotonin for interaction with two different neuronal sites. 6-Hydroxytetrahydro-beta-carboline and 6-hydroxy-3-aminotetrahydrocarbazole were found to be potent inhibitors of serotonin uptake into hypothalamic synaptosomes, with IC50 values of 0.13 microM for each analogue. The type of inhibition, as determined by Dixon plots, was found to be competitive, with Ki's of 3.0 X 10(-8) M and 4.6 X 10(-8) M for the beta-carboline and carbazole derivatives, respectively. Methoxylation or lack of a hydroxy group at the 6 position of the carbazole derivative did not alter inhibitory potency, while methoxy or benzyloxy substitution decreased potency 22- to 326-fold. The serotonin analogues were 20 to 30 times less potent in inhibiting the synaptosomal transport of the catecholamines. With regard to [3H]serotonin binding to membranes obtained from brain homogenates, both analogues exhibited poor affinity compared with the transmitter. However, the beta-carboline derivative was three times as potent as the carbazole analogue. These findings and earlier ones with regard to the effect of the serotonin analogues on brain monoamine oxidase activity support the idea that serotonin analogues interact differentially with the three different serotonergic sites examined.

Animals↗
PubMed1981

Prenatal exposure to imipramine alters early behavioral development and beta adrenergic receptors in rats.

Offspring of rats exposed to water or 15 mg/kg/dy of imipramine (IMI) on gestational day 8 through 20 were examined for behavioral and neurochemical development. IMI-treated mothers gained significantly less weight during pregnancy, but the percentage giving birth, length of gestation and litter size were unaffected. Body weights of IMI-exposed offspring were significantly lower than controls until postnatal day 14 and brain weights were lower until day 30. In IMI-exposed pups, eye-opening occurred significantly earlier, development of the surface righting reflex was delayed and development of negative geotaxis was altered. Hypothalamic levels of noradrenaline and adrenaline were unchanged in IMI pups at 7, 14 and 30 days, but dopamine levels, unaffected at 7 and 14 days, were significantly lower than controls at 30 days. The number of cortical beta adrenergic receptors, measured by [3H]dihydroalprenolol binding, was significantly decreased by 18.7% at 14 days and 9.1% at 30 days. Affinity for binding was increased at 30 days. Brain levels of IMI and its metabolite desmethylimipramine were detectable in newborns prenatally exposed to IMI and desmethylimipramine/IMI ratios were 1.8 times those found in adults. The results indicate that prenatal exposure to IMI produces behavioral and neurochemical consequences lasting well past cessation of drug exposure.

Animals↗
PubMed1981

The effect of chronic lithium treatment on rat pineal N-acetyltransferase rhythm.

Lithium chloride administration to rats for 5 weeks caused a significant decrease in dark-induced activity of rat pineal N-acetyltransferase (E.C.2.3.1.5.). This effect is not observed after 3 days or 3 weeks of treatment. Furthermore, chronic lithium treatment suppressed the amplitude and may have delayed the peak of the diurnal cycle of N-acetyltransferase activity. In vitro, various concentrations of lithium chloride (2, 4 and 10 microM) did not affect N-acetyltransferase activity. Beta adrenergic receptor binding studies with [3H]dihydroalprenolol indicated a decrease in number of pineal beta adrenergic receptors in rats treated chronically with lithium. These results are consistent with a lithium-induced subsensitivity of pineal beta adrenergic receptors and may explain the effect of lithium on pineal-mediated cyclic behaviors.

Acetyltransferases↗
PubMed1981

Surgical and pathological considerations in cherubism.

Although cherubism was recognized over half a century ago, there are few reports in the literature describing the overall management of this puzzling and challenging condition. The early onset of this disease and its continued growth result in therapeutic dilemmas with respect to pathological potential, deformity, dysfunction, and possible facial and emotional scarring. This report describes a staged approach to a major case, utilizing the advantages of current advances such as surgical technology, transoral approach, pantomography, and radioscintography. Foremost consideration is given to the histopathology of this and related fibro-osseous diseases. It is concluded that a curettement-recontouring procedure is the surgical modality of choice.

Adolescent↗
PubMed1981

Postsurgical compressive dressings for the maxillofacial area.

A convenient and functional type of compressive dressing for use in oral and maxillofacial surgery has been described and illustrated. The special nature of the dressing material permits an ease of manipulation and application to particular points that has previously been lacking in this aspect of postsurgical case. The authors have found this material to be easily and quickly applied, readily cleaned, nonallergenic nonrestrictive, retentive, and highly acceptable to the patient. In addition, it may also be used to maintain wet soaks or ice packs. Its effectiveness in minimizing postoperative edema in a variety of maxillofacial surgical procedures has been clinically established.

Adult↗
PubMed1981

Inactivated chromatographic influenza vaccine.

The characteristics of laboratory parameters of inactivated whole influenza virus vaccine, obtained by the purification of allantoic virus cultures on macroporous glass, are presented. The vaccine is characterized by small reactogenicity and safety, which allows it to be used in both adolescents and adults. Seroconversions to hemagglutinin have been found in 80--95% of individuals vaccinated once during the test vaccination by the preparation containing various strains of influenza A/H3N2/virus. Post-vaccination antibody rise has been investigated in the nasal secretion of vaccinated individuals.

Adolescent↗