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Biomedical subjects

D Greenberg

Publications and source records attributed to D Greenberg.

At least 127 records · Page 7Linked to original sources
PubMed1990

A comparison of the effects of ipratropium bromide and metaproterenol sulfate in acute exacerbations of COPD.

Thirty-two patients presenting with acute exacerbations of chronic obstructive pulmonary disease were entered into the following double-blind, crossover study. First (time 0), patients inhaled either ipratropium bromide (54 micrograms) or metaproterenol sulfate (1.95 mg) via a metered dose inhaler (MDI) attached to a device (Inspirease) (phase 1). After 90 minutes, they inhaled whichever of the two medications they had not received in phase 1. This is referred to as phase 2. Pulmonary function (FEV1 and FVC) was measured at time 0, and at 30, 60, and 90 minutes following phase 1 treatment, and at 30, 60, and 90 minutes following phase 2 treatment (120, 150, and 180 minutes from the start of the study). Arterial blood gas samples (n = 20) were obtained at entry into the study and 30 and 90 minutes after phase 1 medication. The groups did not differ in age, degree of airway obstruction, hypoxemia, or theophylline usage at the start of the study. In phase 1, at 90 minutes, pulmonary function in both groups significantly and similarly improved. For ipratropium, FEV1 improved from 0.62 +/- 0.08 L to 0.88 +/- 0.11 L (p less than 0.01) and for metaproterenol FEV1 improved from 0.69 +/- 0.06 to 0.92 +/- 0.09 L (p less than 0.01). There was no further improvement with phase 2 treatment for either group. Thirty minutes after inhaling ipratropium, there was a small but significant rise in PO2 (5.8 +/- 3.0 mm Hg; p less than 0.05) while metaproterenol inhalation resulted in a 6.2 +/- 1.2 mm Hg decline in PO2 (p less than 0.05). These changes were not sustained at 90 minutes. We concluded that for acute exacerbations of COPD, both ipratropium and metaproterenol are effective medications when administered via an MDI attached to a device (Inspirease). However, ipratropium may be a safer choice as it initially did not cause a decline in blood oxygenation.

Acute Disease↗
PubMed1990

Family expressed emotion: concepts, dilemmas and the Israeli perspective.

Family characteristics of high "expressed emotion" (EE) have been found to be predictive of relapse in schizophrenia and other psychiatric disorders. A causal relationship has been postulated between relapse and components of EE as assessed in the relatives with whom the patient has close social contact. Recently, conceptual and methodological aspects of the EE paradigm have become the focus of controversy. We present the dilemmas under debate and discuss the implications relevant to the study of EE in Israel.

Emotions↗
PubMed1990

Core symptoms of posttraumatic stress disorder unimproved by alprazolam treatment.

The authors report a random-assignment, double-blind crossover trial comparing alprazolam and placebo in posttraumatic stress disorder (PTSD). Ten patients fulfilling DSM-III criteria for PTSD completed 5 weeks of treatment on each agent. Improvement in anxiety symptoms was significantly greater during alprazolam treatment but modest in extent. Symptoms specific to PTSD were not significantly altered. The impact of nonspecific symptomatic effects on the outcome of drug trials in PTSD is considered.

Adult↗
PubMed1990

Hoarding as a psychiatric symptom.

Collecting is a normal behavior in childhood and adulthood, while hoarding--the gathering, ordering, and disposal of articles without clear conscious motivation or control--is characterized as the pathologic counterpart of collecting. The literature describing the characteristics of collecting and the theories concerning its underlying mechanisms is presented along with eight case studies of adults who exhibited hoarding as a prominent symptom. It is apparent that hoarding is the final common pathway for a variety of processes: compulsive hoarding in obsessive compulsive disorder, fears of theft and poisoning in paranoid delusions, and the deterioration of habits in organic mental disorder.

Adult↗
PubMed1989

Therapeutic effects of S-35-thiouracil in BALB/c mice carrying Harding-Passey melanoma.

Thiouracil (TU) selectively binds to the pigment melanin during melanogenesis and is rapidly cleared from normal tissues. This compound shows little affinity for pre-formed melanin. BALB/c mice, carrying the subcutaneously transplanted Harding-Passey melanoma, were given i.p. injections of 35S-labeled thiouracil in a range of doses and administration schedules. Injected doses ranged from 1.3 to 10 mCi per mouse with resultant tumor dose rates of 10 to 30 cGy/hr, respectively. At the lower dose rates, growth delay of approximately 1 to 2 weeks was observed in all tumors. At the highest doses used, complete tumor regression (no regrowth) was observed in some cases, with extended growth delays of approximately 6 weeks in the rest. These results illustrate the possible utility of radiolabeled thiouracil as a systemically administered brachytherapy agent for melanoma.

Animals↗
PubMed1989

Energy expenditure during stress ulcer formation in vulnerable rats.

Rat pups separated early from their mothers at day 15 become vulnerable to hypothermia and gastric erosion formation when food deprived and physically restrained on postnatal day 30 (S.H. Ackerman, M. A. Hofer, and H. Weiner, Science Wash. DC. 201: 373-376, 1978, and Gastroenterology 75: 649-654, 1978). We tested the hypothesis that this hypothermia is associated with a decrease in oxidative metabolism. We measured O2 consumption of 30-day-old rat pups that had been previously separated at either day 15 (15w) or day 21 (21w). When food was available, 15w rats used as much O2 as 21w rats. When rats were food deprived or food deprived and restrained, 15w rats used significantly less O2 than 21w rats, implying less heat production. We hypothesized that this decrease in heat production during food deprivation and/or restraint was due to impaired thermogenesis resulting from inadequate release of endogenous norepinephrine (NE), which is a stimulant of brown adipose tissue- (BAT) mediated thermogenesis. To test this hypothesis we administered exogenous NE to 15w to 21w rats. Exogenous NE failed to increase O2 consumption in 21w or 15w rats when injected during either food deprivation or restraint. We concluded that 30-day-old 15w rats have decreased oxidative metabolism during food deprivation and restraint and therefore become hypothermic. This decreased oxidative metabolism does not appear to be attributable to insufficient endogenous NE, since it is not reversed by the addition of exogenous NE. We suggest that a decrease in oxidative metabolism may explain susceptibility to stress ulcers in a number of previously reported experimental models.

Adipose Tissue, Brown↗
PubMed1989

Endogenous cholecystokinin does not decrease food intake or gastric emptying in fasted rats.

To investigate the hypothesized inhibitory effect of cholecystokinin (CCK) released from the small intestine on food intake and gastric emptying, we infused soybean trypsin inhibitor (STI) into the stomach or duodenum of male rats deprived of food for 17 h. Intraduodenal infusions of STI (100-200 mg) before real or sham feeding, or during sham feeding, had no effect on food intake. Intragastric infusions of STI (100-200 mg) also had no effect on gastric emptying. Identical infusions of STI, however, increased bioassayable plasma CCK six to ninefold. The failure of endogenous, small intestinal CCK released by STI to decrease food intake or to decrease gastric emptying is evidence against the hypothesis that the inhibitions of food intake and of gastric emptying are physiological functions of small intestinal CCK in food-deprived rats. In contrast to the negative results with STI, administration of exogenous CCK-8 (2-4 micrograms/kg ip) significantly inhibited food intake and gastric emptying despite producing smaller increases of plasma CCK than STI produced. The reason for the differential effects of exogenous and endogenous CCK is not clear and requires further investigation.

Animals↗
PubMed1989

Recombinant tissue-type plasminogen activator in canine embolic pulmonary hypertension. Effects of bolus versus short-term administration on dynamics of thrombolysis and on pulmonary vascular pressure-flow characteristics.

We used a canine model of embolic pulmonary hypertension, induced by injection of autologous radioactive blood clots, to investigate effects of recombinant tissue-type plasminogen activator (rt-PA) on dynamics of thrombolysis and on pulmonary pressure-flow (PQ) characteristics. Over 5 (rt-PA5) or 15 (rt-PA15) minutes, 1 mg/kg rt-PA was infused. Rate and extent of thrombolysis were assessed by counting over both lung fields with a gamma camera. Emboli increased mean pulmonary artery pressure from 14 to 36 mm Hg (p less than 0.005). This change was predominantly due to an increase in the effective outflow pressure (PI) (from 9 to 29 mm Hg, p less than 0.001), obtained by extrapolation from the linear PQ relation. While pulmonary hemodynamics improved with rt-PA5 and rt-PA15, the change was greatest with rt-PA15. For example, the increase in PI that occurred with embolization was abolished with rt-PA15. Also, the decrease in pulmonary artery pressure was greatest with rt-PA15. While not significantly different, extent of total clot lysis tended to be greatest with rt-PA15 (p less than 0.07). Also, while during infusion, the concentration of rt-PA5 was threefold that of rt-PA15, the corresponding rate of thrombolysis was similar with rt-PA5 and rt-PA15. These results indicate that the improvement in pulmonary hemodynamics with rt-PA is primarily explained by a decrease in PI. Furthermore, they suggest an upper limit to the dose-thrombolytic rate relation with rt-PA.

Animals↗
PubMed1989

Prescribing patterns of neuroactive drugs in 98 schizophrenic patients.

Ninety-eight schizophrenic outpatients receiving pharmacotherapy were surveyed on two census days, 18 months apart. From this study sample it was found that, as recently as 1987, 18% of the patients were prescribed three classes of neuroactive drugs--16% two antipsychotic drugs simultaneously. Of antipsychotics receivers, 44% were prescribed anticholinergics, 3% antidepressants, and 4% benzodiazepines. Between census days, a significant shift from use of oral antipsychotics to the depot form of administration occurred, while polypharmacy frequency remained unchanged. An analysis of the data will provide guidelines for rendering a more rational pharmacological treatment.

Adolescent↗
PubMed1988

Hepatic-portal infusion reduces the satiating potency of CCK-8.

If a satiating effect of endogenous cholecystokinin (CCK) is produced through a circulating hormonal mechanism, then administration of exogenous CCK into the hepatic-portal vein should decrease meal size. We report here that when doses of CCK-8 are injected intraperitoneally, they are at least four times more potent at reducing food intake than equivalent doses infused into the hepatic-portal vein. Intraportally administered CCK-8 at a dose of 32 micrograms.kg-1 had an equivalent satiating potency to 4 micrograms.kg-1 administered intraperitoneally. In contrast, intraportal infusions of the putative satiety hormone, tetradecapeptide bombesin, were equally as effective as intraperitoneal injections for reducing food intake. Bombesin is apparently protected from significant hepatic uptake by its larger size. We conclude that the primary reason for the ineffectiveness of portally administered CCK-8 for reducing food intake is hepatic uptake. These findings support the hypothesis that any satiating effect of endogenous CCK-8 is likely to act primarily through a paracrine mechanism.

Animals↗
PubMed1988

A controlled trial of phenelzine in posttraumatic stress disorder.

Thirteen patients meeting DSM-III criteria for posttraumatic stress disorder participated in a random-assignment, double-blind crossover trial comparing phenelzine (45-75 mg/day) and placebo. Ten patients completed at least 4 weeks of each treatment phase. Clinical response to phenelzine did not differ from placebo, and overall improvement by the end of the study could not be attributed to the active drug. The findings are discussed in the light of preliminary reports suggesting that phenelzine may be an effective treatment for posttraumatic stress disorder.

Adult↗
PubMed1988

Treatment of canine embolic pulmonary hypertension with recombinant tissue plasminogen activator. Efficacy of dosing regimes.

We investigated effects of two dosing regimes of recombinant tissue plasminogen activator (rt-PA) and sodium heparin on pulmonary thrombolysis in a canine model of pulmonary hypertension, induced by injection of radioactive blood clots. By continuously counting over both lung fields with a mobile gamma camera, we correlated rate and extent of pulmonary thrombolysis with corresponding pulmonary hemodynamics. Treatment with heparin, over a 3-hour interval, did not result in significant thrombolysis or in a decrease in mean pulmonary artery pressure (PAP). In contrast, rt-PA caused marked pulmonary thrombolysis. While total clot lysis was similar when 1 mg/kg rt-PA was infused over 15 (rt-PA15) or 90 (rt-PA90) minutes (47% and 42%, respectively), rate of lysis during infusion was markedly increased with rt-PA15 (56% vs. 27%/hr, p less than 0.001). Corresponding to the increased rate of thrombolysis with rt-PA15, relative PAP decrease was greater at 15 and 30 minutes. At 4 hours, PAP decreased most with rt-PA90. However, two of the six dogs given rt-PA15 had an increase in PAP and lung radioactivity 1 hour after rt-PA. This was associated with dislodgment of a previously trapped clot. These results suggest that rt-PA may be appropriate therapy for pulmonary embolism and support further studies designed to optimize dosing regimes.

Animals↗
PubMed1988

Lack of radiographic evidence of interstitial pulmonary edema after maximal exercise in normal subjects.

Recent physiologic studies have indirectly suggested that interstitial pulmonary edema may develop at maximal exercise in normal humans at sea level. Therefore, we compared chest radiographs taken before and immediately after incremental exercise to maximum in 5 healthy young subjects. We looked for evidence of redistribution of pulmonary blood flow, pulmonary venous distension, loss of sharp definition of pulmonary vascular markings, hilar blurring, Kerley's A, B, or C lines, peribronchial or perivascular cuffing, widening of fissures, pleural effusion, and diffuse opacity. We also quantitated radiographic density in 6 areas of the film in each subject. There was no radiographic change to suggest an increase in lung water in any lung zone in any of the subjects. Given the documented sensitivity of chest radiography in this respect, we conclude that any increase in extravascular lung water during exercise must be trivial.

Adult↗
PubMed1987

Bronchial blood flow measured by video dilution technique in sheep.

Bronchial blood flow was studied with the video dilution technique (VDT) in seven sheep. All animals were anesthetized (thiamylal and halothane) and ventilated. A videodensitometer and a videotape replay of the fluoroscopic image of dye moving through the common bronchial artery were used to construct dye mass vs. time curves. The areas under the curves were inversely proportional to flow in the bronchoesophageal artery, the site of dye injection. At thoracotomy, an electromagnetic flow probe (EMFP) was placed on the common bronchial artery (the major branch of the bronchoesophageal artery) to measure blood flow changes simultaneously by EMFP and by VDT. These two methods of measurement of blood flow to the airways were compared to validate the use of VDT in this circulation. Common bronchial artery blood flow was increased by injection of radiocontrast dye into the fluoroscopically positioned bronchoesophageal artery catheter causing hyperosmotically induced hyperemia. In 160 simultaneous measurements in five sheep, the percent change in flow as measured by EMFP and VDT correlated closely (r = 0.96). When flow changed because of spontaneous aortic pressure changes or pharmacologic intervention (28 simultaneous measurements in five sheep), the percent change in flow by EMFP and VDT also correlated well (r = 0.98). Bronchial blood flow changes in sheep can be measured accurately using the video dilution technique.

Animals↗
PubMed1987

Scrupulosity: religious attitudes and clinical presentations.

The attitudes of Catholicism and Judaism to scrupulosity are presented and the similarity between their management programmes and present-day behavioural psychotherapy is noted. Two famous cases are presented from 16th-century Europe and a further four cases from our 20th-century clinic in Jerusalem. Certain common features are noted, typical of obsessive-compulsive disorders, while some features, typical of scrupulosity, are best understood by considering both their religious and psychological importance.

Adult↗
PubMed1987

Infusion of CCK-8 into hepatic-portal vein fails to reduce food intake in rats.

If the putative satiating effect of endogenous cholecystokinin (CCK) is produced through a circulating hormonal mechanism, then administration of exogenous CCK into the hepatic-portal vein should decrease meal size. To test this, one form of endogenous CCK, the C-terminal octapeptide CCK-8, was infused intraportally in doses of 4 and 8 micrograms/kg just prior to a test meal. Neither dose decreased food intake after intraportal infusion even though intraperitoneal administration of 4 micrograms/kg CCK-8 decreased meal size approximately 50% in the same rats. The results suggest that if endogenous CCK-8 has a satiating effect, it acts primarily through a paracrine mechanism.

Animals↗