Search PubMed⌕ Search

Biomedical subjects

R Greenstein

Publications and source records attributed to R Greenstein.

At least 37 records · Page 2Linked to original sources
PubMed1990

Nicardipine infusion for postoperative hypertension after surgery of the head and neck.

The therapy of postoperative hypertension (POH) after head and neck surgery was evaluated in a prospective, randomized, double-blind trial. Nicardipine hydrochloride, a Ca channel-blocker for iv use, was compared with placebo. Patients were initially randomized to receive nicardipine infusion or placebo. Those not responding to placebo were given nicardipine infusion on an open basis. Hypertension was significantly better controlled in patients treated with nicardipine infusion compared with placebo (83% vs. 22%, p less than .002). Subsequently, six (86%) of seven of the placebo failures were successfully treated with nicardipine. There were no significant complications in either group. We conclude that the titratable infusion of nicardipine is an effective and safe method for the control of POH after surgery of the head and neck. Further studies are now warranted comparing nicardipine with other drugs currently used to treat this condition.

Blood Pressure↗
PubMed1990

Human gastric alcohol dehydrogenase: its inhibition by H2-receptor antagonists, and its effect on the bioavailability of ethanol.

Two types of alcohol dehydrogenase isoenzymes (differing in their affinity for ethanol, sensitivity to 4-methylpyrazole, and electrophoretic migration) have been identified in the human stomach. At the high ethanol concentrations prevailing in the gastric lumen during alcohol consumption, the sum of their activities could account for significant oxidation of ethanol. In vitro, these activities were inhibited by cimetidine and ranitidine, but not by famotidine. In vivo, therapeutic doses of cimetidine (but not of famotidine) increased blood ethanol levels when ethanol was given orally, but not when it was given intravenously, indicating a significant contribution of the gastric ADH to the bioavailability and thereby the potential toxicity of ethanol.

Alcohol Dehydrogenase↗
PubMed1990

Postoperative hypertension: a prospective, placebo-controlled, randomized, double-blind trial, with intravenous nicardipine hydrochloride.

Nicardipine hydrochloride, a new calcium channel blocker for intravenous use, has been compared with placebo in a prospective, randomized, double-blind trial on postoperative hypertension. Of 175 patients who signed preoperative consent, 24 (13.7%) met entry criteria. Hypertension was significantly better controlled in nicardipine-treated patients compared with those receiving placebo (93% versus 30%, p less than 0.05). All the placebo failures were subsequently successfully treated with nicardipine. There were no significant complications in either group. The authors conclude that nicardipine HC1 is an effective, safe therapy for postoperative hypertension. Further studies are now indicated comparing it with other drugs currently used to treat this condition.

Double-Blind Method↗
PubMed1990

Segmental intestinal absorption of ranitidine: investigative and therapeutic implications.

The absorption of ranitidine from different segments of the intestinal tract was studied in a subject who had an anatomically divided small intestine. The results indicate that the drug is maximally absorbed from the small bowel rather than the stomach. Subsequent animal studies have shown that absorption of ranitidine in dogs is primarily duodenal followed by jejunal and ileal. The lack of gastric absorption, with predominantly small bowel absorption, may have investigational and therapeutic implications in a variety of gastrointestinal diseases.

Animals↗
PubMed1989

Visual compatibility of enalaprilat with commonly used critical care medications during simulated Y-site injection.

Physical incompatibility studies between an intravenous angiotensin-converting enzyme inhibitor, enalaprilat, and potentially coadministrable ICU medications have been performed. Forty-one medications and four solutions were evaluated. The medications were anesthetic/narcotics, antibiotics, an anticoagulant, a bronchodilator, electrolyte solutions, fluids, H-2 receptor blocking agents, steroids and vasoactive agents. There was no turbidity, precipitation, or color change caused by the admixing of enalaprilat with any of the 45 agents studied. This study did not take bioavailability into consideration.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1989

The compatibility of nicardipine hydrochloride injection with various ICU medications during simulated Y-site injection.

Physical incompatibility studies between an intravenous calcium channel antagonist, nicardipine hydrochloride, and potentially coadministerable ICU medications have been performed. Forty-one medications and four solutions were evaluated. The medications were anesthetic/narcotics, antibiotics, an anticoagulant, a bronchodilator, electrolyte solutions, fluids, H2 receptor blocking agents, steroids and vasoactive agents. Of the forty-five substances, three showed evidence of physical incompatibility as manifested by turbidity, precipitation, or color change. All three were antibiotics. These were ampicillin, ampicillin/sulbactam sodium, and cefoperazone. We conclude that until bioavailability studies are performed these three antibiotics should not be coadministered with nicardipine HCl.

Ampicillin↗
PubMed1987

Congenital melanoma with multiple prenatal metastases.

A 1.95-kg fetus delivered at 33 weeks' gestational age survived less than 1 hour. Physical examination and autopsy disclosed an enormous, protuberant primary malignant melanoma of the skin, enveloping most of the back. A rim of surrounding hyperpigmented skin proved to be a giant congenital melanocytic nevus (GCMN), from which the cutaneous melanoma had arisen. Autopsy demonstrated metastatic melanoma in the lungs, liver, spinal cord, leptomeninges, and placenta. Radiography and dissection confirmed that the melanoma had minimal connection to spinal or neural structures. The mother was clinically free of tumor 8 months after she was delivered of the infant. Pathologic, radiographic, histologic, immunohistochemical, and ultrastructural investigations of this unique case are presented.

Female↗
PubMed1983

Secretin responses to feeding and acid load.

Secretin can be readily concentrated from 10 ml of plasma by adsorption to and elution from octadecylsilyl silica columns (C18 Sep-Pak cartridges). This method of concentration is more expedient than either ethanol extraction or adsorption to and elution from precipitated silica (QUSO G32) and permits detection of secretin in plasma at concentrations of 1 pg/ml or greater. Basal secretin in normal subjects was found to be less than 4 pg/ml of plasma. In response to an STM, plasma secretin increased on the average to twice the fasting level, but in response to an oral SAL, it generally increased about 10-fold.

Acids↗
PubMed1980

Retinitis pigmentosa and colon cancer: a previously unreported association.

Retinitis pigmentosa, a hereditary disease characterized by progressive retinal degeneration and blindness, has been associated with numerous diseases. We report the first association between retinitis pigmentosa and colon cancer in 3 of 53 hospitalized patients with retinitis pigmentosa at the Massachusetts General Hospital and Massachusetts Eye and Ear Infirmary for the period from 1962 to 1977.

Adult↗
PubMed1979

Management of asparaginase induced hemorrhagic pancreatitis complicated by pseudocyst.

Asparaginase induced hemorrhagic pancreatitis is a rare but serious development occurring in less than 0.5% of patients treated with this drug. Severe pancreatitis with progressive abdominal distention, toxemia, hypotension and respiratory insufficiency occurred in an 18-year-old patient with acute lymphoblastic leukemia following treatment with asparaginase. There was a dramatic response to high flow peritoneal lavage with rapid recovery within 24 hours from a moribund state. The subsequent development of a pseudocyst, with progressive increase in size and development of obstructive symptoms, required surgical decompression. Transgastric cystogastrostomy was successfully carried out.

Adolescent↗
PubMed1979

Effects of contingent payment on compliance with a naltrexone regimen.

The effects of several schedules of payment on duration and patterns of compliance with a naltrexone regimen were examined. Patients were paid under contingencies based on either number of doses ingested or on a fixed time schedule. Reinforcement schedules based on number of doses ingested produced more consistent treatment-oriented behavior than a time-based schedule. Covariation between behavior and alternating contingencies (A-B-A) indicated that the schedules contributed to increased duration of treatment compared to previous noncontingent payment. The issue of using extrinsic reinforcers such as monetary payment to enhance compliance is discussed and additional procedures are suggested.

Adult↗