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Biomedical subjects

M Feinberg

Publications and source records attributed to M Feinberg.

84 records · Page 5Linked to original sources
PubMed1979

Effects of dopamine agonists and antagonists in Tourette's disease.

The actions of haloperidol, dextroamphetamine sulfate, levamfetamine succinate, apomorphine, and piribedil were studied in two patients with Giles de la Tourette's disease in an attempt to clarify the catecholamine mechanisms involved in this condition. Both dextroamphetamine and levamfetamine increased the severity of the symptoms; dextroamphetamine was more potent. Haloperidol controlled the symptoms and also antagonized the effect of dextroamphetamine. Apomorphine injections reduced the severity of symptoms, even in the presence of dextroamphetamine. We conclude that dopamine rather than norepinephrine is the principal catecholamine responsible for the symptoms. The effect of apomorphine may be understood through its action on postulated presynaptic inhibitory dopamine receptors, or other presynaptic mechanisms of action.

Adolescent↗
PubMed1979

Rapid development of cirrhosis secondary to squamous cell carcinoma of the common bile duct.

A 68-year-old male underwent cholecystectomy with a normal operative wedge liver biopsy. Five months later he presented with secondary biliary cirrhosis and signs of portal hypertension and hepatocellular failure. At autopsy, a squamous cell carcinoma of the bile duct was found. This case represents an unusually rapid development of cirrhosis secondary to extrahepatic biliary obstruction with documentation of normal liver histology five months prior to his last admission.

Aged↗
PubMed1977

Carcinoma arising in the wall of a breast cyst during pregnancy.

A 23-year-old patient developed a carcinoma in the wall of a breast cyst during the second trimester of an otherwise uncomplicated pregnancy. A review of the literature revealed 7 reported cases of carcinoma of the breast arising in a cyst wall. However, none of these these cases has been associated with pregnancy. The relationship of fibrocystic disease and carcinoma of the breast is discussed. The possible influence of pregnancy and age on the prognosis of this patient are also considered.

Adult↗
PubMed1975

Pulmonary talc embolization.

A young woman with a history of drug abuse rapidly developed cor pulmonale, restrictive pulmonary defect, low diffusion capacity, and a suggestion of left ventricular dysfunction. She died from complications after a lung biopsy. Microscopic examination showed talc granulomas and arteritis. Some form of closed biopsy is probably safer, and trial of corticosteroid therapy seems warranted for this diagnosis. Talc ia a dangerous ingredient for any oral preparation that is likely to be used parenterally.

Adult↗
PubMed1975

The solution of pharmacological problems with computers. Part 9: Kinetics of the inhibition of the enzyme morphine-N-demethylase by N-allylnormorphine. Mathematical analysis by a FORTRAN-program.

In this paper, we present a method for statistical analysis of enzyme-kinetic data. This analysis allows determination of the character of the inhibition of an enzyme reaction, and computes the 95% confidence limits of the dissociation constants and of Vmax. This method involves the solution of the Michaelis-Menten equation, (see article for formula), using the Guass-Newton iteration.

Animals↗
PubMedDate not supplied

Adolescent, parent, and observer perceptions of parenting: genetic and environmental influences on shared and distinct perceptions.

Agreement among reporters on features of family life, whether family members or outside observers, is considered to be low. This study, which involved a national sample of 720 families comprised of identical and fraternal twins, full siblings, half siblings, and biologically unrelated stepsiblings, examined the issue of low interrater agreement by decomposing the common and unique variance among parent, child, and observer reports of parenting behaviors (warmth and negativity) into genetic and environmental factors. Quantitative genetic analyses were employed to decompose the "Social" level of perception (common variance among parents, children, observers), the level of "Family" subculture (common variance only among parents and children), and the unique "Individual" level into genetic and environmental components. It was predicted that genetic factors would account for substantial portions of the variance at the Social and Family levels; nonshared environmental factors were expected to influence variance unique to child reports; and shared environmental factors were expected to influence variance unique to parent reports. A second and related aim of the study was to examine the subjective-objective dimension of genetic effects on measures of the environment. Results of model-fitting analyses generally supported the predictions for parental warmth and negativity at the Family and Individual levels. At the Social level, genetic factors were predominant for parental negativity and shared environmental factors for parental warmth. The findings are discussed in terms of genetically influenced child effects on parenting and methodological difficulties in constructing latent variables.

Adolescent↗
PubMedDate not supplied

The problems of anticholinergic adverse effects in older patients.

The old saying 'red as a beet, dry as a bone, blind as a bat, hot as a hare, mad as a hatter' is often quoted when describing the autonomic effects of drugs that block the muscarinic cholinergic system. These effects may be subtle or dramatic, yet can be overlooked or discounted as a natural consequence of old age. Elderly patients can be particularly sensitive to the anticholinergic action of drugs because of physiological and pathophysiological changes that often accompany the aging process. The use of multiple drugs, a common finding in older patients, may result in pharmacodynamic and pharmacokinetic drug interactions that heighten anticholinergic effects. While the classic anticholinergic problems of decreased secretions, slowed gastrointestinal motility, blurred vision, increased heart rate, heat intolerance, sedation and possibly mild confusion, may be uncomfortable for a younger patient in relatively good health, these effects can be disastrous for older patients. Even the most common peripheral anticholinergic complaint of dry mouth can reduce the ability to communicate, predispose to malnutrition, promote mucosal damage, denture misfit or dental caries, and increase the risk of serious respiratory infection secondary to loss of antimicrobial activity of saliva. Mydriasis and the inability to accommodate will impair near vision and may precipitate narrow angle glaucoma in predisposed patients, but less obviously could lead to an increased risk of accidents, including falls. Somatic complaints of constipation and urinary hesitancy, could, in the presence of anticholinergic challenge, result in faecal impaction or urinary retention. Cardiac effects may be poorly tolerated. Increases in heart rate may precipitate or worsen angina. Finally, thermoregulatory impairment induced by anticholinergics, which block the ability to sweat, may lead to life threatening hyperthermia. Central anticholinergic effects range from sedation, mild confusion and inability to concentration to frank delirium. Even mild effects can reduce function and increase dependency. At any level of care, the loss of independence increases the caregiver burden, costs, and most importantly, can negatively affect quality of life. Many age-related and disease-related conditions may predispose elderly patients to anticholinergic drug toxicity. Careful attention to anticholinergic effects when prescribing drugs, patient education, regular review of the entire drug regimen, and familiarity with the signs and symptoms of anticholinergic toxicity will help to reduce the risk of drug-induced problems.

Aged↗
PubMedDate not supplied

Determination of carbohydrates in soluble coffee by anion-exchange chromatography with pulsed amperometric detection: interlaboratory study.

A collaborative study was conducted to validate a liquid chromatographic (LC) method to determine the free and total (after acid hydrolysis) carbohydrate profile of soluble coffee. Carbohydrates were separated on a pellicular anion-exchange column using pure water as mobile phase, and were detected by pulsed amperometry. Eleven collaborators were sent 6 test samples of commercial soluble coffee for duplicate analysis. They were also sent a practice sample with known levels of free and total carbohydrates and material for preparation of all standard solutions. The reproducibility relative standard deviations (RSDR) were 9.9-59.5% for mannitol, 35.6-72.6% for fucose, 4.9-21.1% for arabinose, 4.1-13.0% for galactose, 6.1-24.3% for glucose, 10.0-41.6% for sucrose, 20.2-37.7% for xylose, 10.6-40.0% for mannose, 15.5-71.7% for fructose, and 17.8-97.9% for ribose. Precision in the determination of free and total carbohydrates was very similar. The average repeatability RSDr and RSDR values were 4.5 and 14.3%, respectively, for carbohydrate levels above 0.3%. The precision of the technique was considered good, regardless of the usual peak integration problems always encountered in LC, the low levels of free carbohydrates, the hydrolysis step, and the relative lack of experience of most participating laboratories. The method allows good and reproducible separation of all major carbohydrates found in soluble coffee and is, therefore, suitable for routine analysis.

Carbohydrates↗