Biomedical subjects

A Hurwitz

Publications and source records attributed to A Hurwitz.

At least 91 records · Page 5Linked to original sources

PubMed1989

The benefit of a home exercise regimen for ambulatory Parkinson's disease patients.

The Home Visiting Exercise Project assessed the impact (benefit) of a weekly home exercise regimen for ambulatory patients with Parkinson's disease (PD). The exercises were taught by senior nursing students. In a case control study with 29 patients, half were assigned to a home-supervised exercise regimen and the other half were assigned a home visit without an exercise regimen. The hypothesis was that PD patients who received a weekly home nursing student-supervised exercise regimen would experience better mobility, feeding and self-care as compared to patients who received a weekly home visit from a nursing student without exercises. Patients who participated in the exercise regimen showed significant improvement in recent memory, diminution of nausea, improved sucking ability, and less urinary retention and incontinence. This research was supported by a grant from the National Parkinson's Foundation, Miami, Florida.

Activities of Daily Living↗

PubMed1989

The pharmacology of antiulcer drugs.

The use of medications for the treatment of gastrointestinal ulcers has evolved to a great extent since the early days of therapy with diet and antacids. Today a number of different agents are available to treat the causative factors of ulcer formation. Currently, antacids, histamine2-receptor antagonists, and sucralfate are considered frontline therapies suitable for most patients. The future also looks promising for newer agents, such as omeprazole and prostaglandin analogs. The purpose of this article is to provide practitioners with an understanding of the achieved more efficiently and effectively.

Anti-Ulcer Agents↗

PubMed1989

In-vitro steroid production by human granulosa lutein cells in long-term cultures.

delta 4 and delta 5 pathway steroidogenesis by human granulosa lutein cells (GLC) in long-term cultures (6-8 days) was investigated under basal (10% serum + medium + GLC) and stimulated (human chorionic gonadotropins (hCG), 100 mIU/ml) conditions. In the delta 4 pathway, 17-hydroxyprogesterone (17-OHP) secretion increased from 160-fold at 48 hours of culture to 360-fold at 144 hours under basal conditions, when compared with the respective controls (concentrations in the 10% serum added to the medium) (p less than 0.005). HCG further augmented 17-OHP production significantly at 96, 144 and 192 hours of culture. Progesterone (P) secretion behaved similarly, and increased from 150-fold at 48 hours to 560-fold at 96 hours when compared with controls, being further stimulated by hCG. In contrast, androstenedione (A) secretion throughout the entire culture period increased only slightly (3-5-fold) under both basal and stimulated conditions, when compared with the respective controls. In the delta 5 pathway, the secretory pattern of 17-hydroxypregnenolone (17-OHPregn) and dehydroepiandrosterone (DHEA) was similar to that observed with A, and both steroids increased only slightly under basal and stimulated conditions, when compared with their respective controls. In conclusion, 17-OHP and P are secreted in very significant amounts during the entire culture period while 17-OHPregn, DHEA and A are secreted in extremely small amounts. These results demonstrate that the delta 5 pathway is inactive in long-term human GLC cultures while the delta 4 pathway is active in certain portions only.(ABSTRACT TRUNCATED AT 250 WORDS)

17-alpha-Hydroxypregnenolone↗

PubMed1988

The significance and importance of prenatal diagnosis of fetal cardiac malformations by Doppler echocardiography.

Pulsed Doppler echocardiography is an excellent technique for cardiac diagnosis and assessment of cardiac performance in combination with M-mode and two-dimensional echocardiography. Its exact role in fetal cardiac diagnosis has not been established. We examined 67 high-risk fetuses for cardiac malformations and found cardiac abnormalities or malfunction in 15. In four fetuses pulsed Doppler echocardiography played a primary or a definitive diagnostic role: One fetus had a complete atrioventricular canal, another lacked the pulmonary valve, the third had transposition of the great vessels without ventricular septal defect, and the fourth had high cardiac output failure caused by placental chorioangioma. Pulsed Doppler echocardiography is an integral part of the ultrasonic cardiac examination in high-risk fetuses and should be used in combination with two-dimensional and M-mode echocardiography. It has an important place in the diagnosis of high-risk fetuses and may have a primary role in the diagnosis of fetuses when ultrasound resolution is poor, where cardiac circulatory hemodynamics are essential for diagnosis, and in complicated cardiac malformations in which a comprehensive and accurate diagnosis can be achieved only with pulsed Doppler echocardiography.

Echocardiography↗

PubMed1988

Morphine effects on gentamicin disposition and toxicity in mice.

Morphine has been shown to reduce renal and hepatic clearance of several xenobiotics in rodents. After iv administration of gentamicin, 10 to 30 mg/kg, its plasma levels were elevated in mice given morphine, 20 mg/kg sc. Plasma clearance of gentamicin was nearly halved by morphine, due primarily to lowering of the elimination constant of gentamicin from 0.03 to 0.02 min-1 (p less than 0.01). Morphine also significantly reduced urine levels of gentamicin and urine volume. In mice given naloxone, 2 mg/kg sc, morphine did not significantly raise plasma levels of gentamicin nor reduce its elimination into urine. Mice were made tolerant by morphine administration for 9 days at ascending doses to 100 mg/kg twice daily. An acute challenge with morphine, 20 mg/kg, was less effective in raising plasma levels of gentamicin or lowering its urinary elimination in tolerant mice than after chronic saline treatment. Partial tolerance to acutely administered morphine and reversal of morphine effects by naloxone suggest opioid receptor-mediated reduction of glomerular filtration by morphine in mice. Despite marked elevation of plasma gentamicin levels in morphine-treated mice, narcotic administration did not significantly increase the acute toxicity of a single dose of gentamicin. LD50 of acutely administered iv gentamicin was 51.6 mg/kg after saline and 45.3 mg/kg after treatment with morphine, 20 mg/kg sc. However, this dose of morphine enhanced the lethality of intravenously infused gentamicin. Morphine administration significantly reduced the dose of infused gentamicin needed to achieve the critical lethal plasma level.

Animals↗

PubMed1988

Effect of viscous macromolecules on peritoneal plasminogen activator activity: a potential mechanism for their ability to reduce postoperative adhesion formation.

Activity of peritoneal plasminogen activator and its regulation by dextran and other macromolecules that clinically suppress postoperative adhesions was studied. Plasminogen activator activity was assayed by a two-stage globinolytic assay that monitors formation of plasmin, as well as by cleavage of a chromogenic peptide substrate (S-2444) in the presence of aprotinin (Trasylol). Plasminogen activator activity was located on the outer surface of human peritoneum. Incubation of peritoneal tissue with buffer in vitro (conditioning) prompted release of plasminogen activator into the conditioning medium. The released plasminogen activator formed a single band on sodium dodecyl sulfate-gel electrophoresis at an apparent molecular weight of 174,000 and was markedly suppressed by antiserum raised against human melanoma tissue-type plasminogen activator. Nonspecific proteolytic activity did not accumulate in the medium during conditioning. The presence of dextran 80 during conditioning of peritoneum reversibly suppressed tissue-bound plasminogen activator activity and reduced plasminogen activator activity in the spent medium. A similar inhibition of peritoneal plasminogen activator was induced by dextran 500, methyl cellulose, and polyvinylpyrrolidone. Dextran, when added to the medium after conditioning, had no direct inhibitory effect on plasminogen activator activity. Dextran did not induce peritoneal production of inhibitor(s) of trypsin, chymotrypsin, or urokinase. On the basis of these findings, two possible mechanisms for the effect of viscous polymers in the reduction of adhesion formation are proposed. These mechanisms consider the importance of peritoneal tissue-type plasminogen activator for removal of fibrin clots and suggest that polymer coating either prevents the shedding of plasminogen activator into the abdominal cavity or reduces the access of fibrin clots to the serosal surfaces.

Abdomen↗

PubMed1988

Clonidine effects on disposition of xenobiotics in rats: inhibited elimination of flow-limited but not extraction-limited agents.

1. The alpha 2-adrenoceptor agonist, clonidine, reduces the hepatobiliary clearance of the anionic dye, sulphobromophthalein (BSP) in rodents. We now compare the effects of clonidine on BSP elimination with its effects on disposition of compounds which are metabolized by hepatic microsomal mixed function oxidases. 2. BSP, 100 mg kg-1 was administered i.v. to rats at 4 h after s.c. saline or clonidine, 0.2 mg kg-1. Thirty min later, plasma BSP levels were 121.4 +/- 2.25 micrograms ml-1 in saline-treated rats, while in clonidine-treated rats they were 631.5 +/- 141.0 micrograms ml-1. Clonidine raised hepatic BSP levels from 256.0 +/- 28.9 micrograms g-1 tissue to 568.5 +/- 86.5 micrograms g-1. 3. Acute administration of clonidine (0.2 mg kg-1 s.c.) or repeated clonidine dosing (0.2 mg kg-1, s.c. twice daily for 10 days) did not affect the disposition of intravenously administered [14C]-antipyrine (15 mg kg-1). 4. Activities of the P450 mixed function oxidase enzymes, aniline hydroxylase and aminopyrine N-demethylase, were identical in liver microsomes from saline-treated rats and in microsomes from rats given single or multiple s.c. doses of clonidine (0.2 mg kg-1). 5. Addition of clonidine or other 2-substituted imidazoles at concentrations up to 2 microM did not affect the activities of aniline hydroxylase or of aminopyrine N-demethylase in suspensions of rat liver microsomes. Other substituted imidazoles, including cimetidine, clotrimazole and metronidazole, at concentrations of 0.2 microM or higher, inhibited the activities of these microsomal enzymes. 6. Clonidine slowed BSP elimination, which is probably hepatic blood flow-limited, but not the extraction-limited elimination of antipyrine, which is metabolized by hepatic microsomal enzymes.

Animals↗

PubMed1988

The management of persistent clear pelvic cysts diagnosed by ultrasonography.

Between December 1981 and June 1986, 52 women examined by ultrasonography were found to have clear pelvic cysts more than 5 cm in average diameter, without septa or solid areas. The cysts were persistent and did not respond to contraceptive pills for four to eight weeks. In all cases, there were histologic or cytologic results from surgical specimens or fluid aspirated from the cysts. In 15 women, the cysts were aspirated and revealed no malignant cells. Thirty-seven women underwent laparotomy, of whom 11 (29%) were found to have benign ovarian neoplasms (nine cystadenomas and two dermoid cysts). Because benign ovarian neoplasms are potentially malignant, and because a large number was found in our study, we recommend removal of the cysts by excision rather than aspiration.

Adolescent↗

PubMed1987

A novel acute toxicity resulting from the administration of morphine and adriamycin to mice.

The toxic potential of the combination of morphine and Adriamycin (doxorubicin) has been evaluated in mice. Intravenous administration of 20 or 40 mg Adriamycin/kg resulted in a dose-related mortality beginning 4 days postdose. Increasing the dose of Adriamycin to 75 mg/kg caused a biphasic mortality pattern, with 30% of the animals dying within 30 min of drug treatment. Pretreatment with morphine (20 mg/kg) reduced by 80% the dose of Adriamycin required to induce a 30% mortality at 30 min post-Adriamycin administration. Morphine pretreatment also caused a dose-dependent increase in plasma Adriamycin, as measured by total plasma fluorescence. Morphine or Adriamycin administered alone resulted in a slight hematocrit increase. The combination of morphine and Adriamycin caused an increase in hematocrit to maximal levels of approximately 75% from basal levels of about 48%. The increase in hematocrit after morphine plus Adriamycin exceeded the rise caused by higher doses of Adriamycin which, without morphine, resulted in similar plasma Adriamycin levels. The temporal relationship between the elevated hematocrit and early (30 min) mortality suggest a cause/effect relationship between these two events following combined morphine plus Adriamycin treatment.

Animals↗

PubMed1987

Mechanism of hematocrit increase induced by the combined administration of morphine and adriamycin: role of histamine release.

The mechanism by which morphine interacts with Adriamycin to increase hematocrit has been investigated in mice. Treatment with Adriamycin (12.8 mg/kg, iv) or morphine (20 mg/kg, sc) resulted in slight increases in hematocrit 30 min postdose, while animals given sc morphine 30 min prior to iv Adriamycin exhibited significant increases in hematocrit as early as 1 min post-Adriamycin. The hematocrit increase reached maximal levels 12 min post-Adriamycin and returned to basal values 4 hr postdose. Splenectomizing animals prior to morphine and Adriamycin treatment had no effect on the drug-induced hematocrit increase. This indicates that red cell release from splenic contracture is not the mechanism for the hematocrit increase. Measurement of plasma histamine levels following drug treatment demonstrated a marked and rapid rise in plasma histamine levels reaching maximal values 1 min post-Adriamycin. Adriamycin alone triggered this release; however, morphine pretreatment resulted in a higher maximum and more prolonged elevation of plasma histamine levels. Treatment with pyrilamine (3.1-50 mg/kg, ip) prior to morphine and Adriamycin administration partially reversed drug-induced hematocrit increase and protected against resultant lethality. Cimetidine (50-200 mg/kg, ip) treatment was not effective. The temporal relationship between hematocrit and histamine increases suggests a cause/effect relationship between released histamine and hematocrit elevation. Protection by pyrilamine and not cimetidine further supports this cause/effect relationship and indicates the effects is mediated via histamine type 1 receptors.

Animals↗

PubMed1987

Effects of adrenoceptor agonists and antagonists on sulfobromophthalein disposition in mice.

The effects of alpha 2-adrenoceptor agonists on sulfobromophthalein (BSP) disposition in mice were studied. It was found that agents with both central and peripheral activities (clonidine, guanabenz, B-HT 920 and methyldopa) as well as peripherally acting alpha 2-adrenoceptor agonists (para amino-clonidine and St 91) inhibited sulfobromophthalein disposition in the mouse, and also caused substantial hypothermia. The effects of these agonists were inhibited by yohimbine, a specific alpha 2-antagonist, except for those of para amino-clonidine where only partial reversal was achieved. The effects of clonidine on BSP disposition were also reversed by piperoxan but not by the alpha 1-adrenoceptor antagonists, prazosin and phenoxybenzamine, nor by the beta-blocker, propranolol. These results suggest that, in mice, peripheral alpha 2-adrenoceptors are involved in the effects of the alpha-agonists on BSP disposition.

Animals↗

PubMed1987

Tolerance to effects of clonidine and morphine on sulfobromophthalein disposition in mice.

Chronic treatment of mice with clonidine or morphine caused tolerance to the analgesic and thermoregulatory effects of these drugs. After chronic morphine, mice also became tolerant to the analgesic and thermoregulatory effects of clonidine. Cross tolerance to the hypothermic effect of morphine was demonstrated after chronic clonidine administration, but no diminution of morphine-induced analgesia could be shown. Morphine and clonidine acutely increased the retention of sulfobromophthalein (BSP) in plasma and liver. Chronic dosing with morphine or clonidine caused partial tolerance and cross-tolerance to the rise in hepatic BSP caused by an acute challenge with either agonist. However, both drugs elevated plasma BSP levels similarly in tolerant and non-tolerant mice. Thus, regimens which readily induced tolerance to the analgesic and hypothermic effects of morphine or clonidine were only partially effective in modifying the acute hepatobiliary effects of these drugs.

Animals↗

PubMed1987

Migraine prophylaxis. A comparison of propranolol and amitriptyline.

The comparative efficacy of propranolol and amitriptyline in the prophylaxis of migraine headache was studied in 30 patients in a double-blind, placebo-controlled, crossover design. Headache response to medication was measured monthly by compilation of headache scores derived from quantitative data recorded by patients in a daily diary; at each visit, Zung and Hamilton tests for depression and the Spielberger state test for anxiety were performed. In the absence of clinical toxicity at monthly visits, the decision to maintain the current dose or raise it was made by a computer, which compared current headache score with that of the previous month. Both drugs were superior to placebo. Neither drug was superior to the other. The effectiveness of neither drug correlated with a decrease in anxiety or depression demonstrated by psychological testing.

Adult↗

PubMed1987

Theophylline absorption from sustained-release products: comparative steady-state bioavailability of once-daily Theo-Dur, Theo-24, and Uniphyl.

Theophylline absorption from three sustained-release formulations was evaluated in 18 healthy men. First, a 600-mg oral dose of aminophylline, a rapidly absorbed formulation, was studied to confirm that theophylline clearance was in the expected range (mean +/- SD, 0.710 +/- 0.096 mL/min/kg), t1/2 = 6.9 +/- 1.1 hr. Then each of the three sustained-release formulations was given at one hour before breakfast for eight days to achieve steady state. Multiple blood samples were drawn on days 7 and 8 over two complete dosing intervals. After a six-day drug-free period each subject was crossed over to the next product. At steady state, mean fluctuations of serum theophylline levels were more than 200% with Theo-Dur (Key Pharmaceuticals, Miami, FL), more than 150% with Uniphyl (Purdue-Frederick, Norwalk, CT), and about 75% with Theo-24 (Searle Laboratories, Chicago, IL). Theophylline Cmax levels averaged 16.5 micrograms/mL after 900 mg Theo-Dur, with 8% exceeding 20 micrograms/mL. Despite these high peak levels, nearly half of the Cmin levels were below 5 micrograms/mL. Uniphyl administration resulted in three-fourths of trough levels to be at 5 micrograms/mL or lower. Peak levels from 800-mg daily doses of Uniphyl were also low, with 42% never reaching 10 micrograms/mL. With Theo-24 only 17% of trough levels were below 5 micrograms/mL, as compared to 47% with Theo-Dur and 72% with Uniphyl. The three products differed in the areas under the serum concentration-time curves (AUC), which reflect bioavailability. Theo-Dur AUC was nearly equivalent to that of rapidly absorbed aminophylline (when adjusted for dosage).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1987

Multiple comparisons and nonparametric statistical tests on a programmable calculator.

Calculator programs are provided for statistical tests for comparing groups of data. These tests can be applied when t-tests are inappropriate, as for multiple comparisons, or for evaluating groups of data that are not distributed normally or have unequal variances. The programs, designed to run on the least expensive Hewlett-Packard programmable scientific calculator, Model HP-11C, should place these statistical tests within easy reach of most students and investigators.

Analysis of Variance↗

PubMed1987

In utero ponderal index as a prognostic factor in the evaluation of intrauterine growth retardation.

The in utero ponderal index has become a method of estimating fetal growth. Several methods have been used in the formulation of the in utero ponderal index. In the present study, 1040 pregnant women underwent ultrasonic examination between 24 and 41 weeks of gestation, and the in utero ponderal index was determined by dividing the estimated fetal weight by the third power of the femur length, rendering a relatively constant value of 8.345 +/- 2.5 (2 SD). Fifty-one cases were defined as intrauterine growth retardation due to an estimated fetal weight lower than the tenth percentile for gestational age. The in utero ponderal index proved to be a valuable index in the prediction of fetal outcome in those cases of intrauterine growth retardation in which the in utero ponderal index was smaller than 1 SD from the average of 8.345. Fetal and neonatal well-being was clearly compromised when intrauterine growth retardation was associated with a low in utero ponderal index.

Birth Weight↗

PubMed1987

The effect of insulin on progesterone production and cellular growth in long-term cultures of human granulosa lutein cells.

The direct action of insulin on human granulosa lutein cells (GLCs) in long-term cultures obtained from in vitro fertilization (IVF) cycles was investigated. Progesterone (P) secretion by GLC increased progressively in both basal and human chorionic gonadotropin (hCG; 100 mIU/ml) stimulated conditions up to 4 days in culture, and plateaued thereafter. Insulin (0.0025 mU/ml to 2500 mU/ml) had no effect on either basal or hCG stimulation during the culture period. GLC in culture formed a monolayer and multiplied at a rate of approximately once every 3 days. Neither morphology nor cell division was affected by insulin in supraphysiologic levels (25 mU/ml). These results suggest that GLC obtained from preovulatory follicles in an IVF program are already stimulated maximally by in vivo exposure to high doses of human menopausal gonadotropin (hMG)/hCG administered to the women. Contrary to its stimulatory effect on early preovulatory granulosa cells, insulin dose not affect P production, cellular morphology, or growth rate of luteinized granulosa cells.

Cell Division↗

PubMed1987

Progesterone enhancement of prostaglandin E2 production by fetal placental macrophages.

The role of progesterone in immunoregulation at the fetomaternal interface at physiological concentrations (2-6 micrograms/ml) is controversial. This study examines the effect of progesterone on maternal lymphocyte proliferation in a one-way mixed lymphocytic reaction (MLR) stimulated by allogenic lymphocytes as well as on prostaglandin production and secretion by fetal placental macrophages. No suppressive effect on maternal lymphocyte proliferation was found at progesterone levels of up to 20 micrograms/ml. However, physiological concentrations of progesterone were found to induce a significant increase in the fetal macrophage release of PGE2, which is well known as a strong immunosuppressant. PGI2 production and secretion by these cells, measured by the appearance of its 6-keto-PGF1 alpha product, was not affected by incubation with progesterone. Enhancement of PGE2 secretion by progesterone may partly explain the roles of progesterone and fetal placental macrophages in immunosuppression at the fetomaternal interface.

Cells, Cultured↗