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D Greenberg

Publications and source records attributed to D Greenberg.

At least 109 records · Page 6Linked to original sources
PubMed1991

Failure to detect increases in brain dopamine metabolism in rats sham feeding sucrose and corn oil.

In a recent study we found that when rats sham fed 6% sucrose, 10% sucrose, and 100% corn oil, the rank order of inhibitory potency for D-1 and D-2 receptor antagonists was 6% sucrose greater than 10% sucrose greater than 100% corn oil. In a complementary study, sham-feeding rats preferred 100% corn oil greater than 10% sucrose greater than 6% sucrose as measured by two-bottle preference tests. The preferences are evidence for the rank order of reward value of these solutions. In the present study we tested the hypothesis that the relative antagonist potencies were due to differential release of DA, dependent on the reward value of the sham-fed solution. Dopamine metabolism, estimated by the ratio of dihydroxphenylacetic acid (DOPAC) to DA, was measured in forebrain-DA terminal fields during sham feeding of 100% corn oil, 6% sucrose, and 10% sucrose. The results did not support our hypothesis: no increase in DA metabolism was observed after the sham feeding of any solution.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

Treatment of Charcot spinal arthropathy following traumatic paraplegia.

Four cases of Charcot's spinal arthropathy in patients with complete traumatic paraplegia were diagnosed an average of 12 years (range, 4-22 years) postinjury. Each patient had previous posterior spinal fusion with Harrington instrumentation. The Charcot joint occurred just below the fusion near the thoracolumbar junction and well below the level of spinal cord injury. All four patients experienced progressive kyphosis, flexion instability, and loss of height. Each underwent a treatment protocol that included anterior fusion with partial resection of the Charcot joint and staged posterior spinal fusion and stabilization with Cotrel-Dubousset (CD) rods. At follow-up evaluation 18-30 months postoperatively, three of four patients showed complete healing with kyphosis correction. One patient developed loosening of his lower hooks at 6 months postoperatively and required posterior revision with ultimate healing. Resection of the involved segments along with two-stage fusion with segmental instrumentation provides excellent management of this difficult problem.

Adult↗
PubMed1991

Effects of flow on recombinant tissue plasminogen activator-induced pulmonary thrombolysis.

We employed a canine model of pulmonary embolism induced by injection of radioactive blood clots to investigate effects of changes in cardiac output (CO) on recombinant tissue plasminogen activator- (rtPA) induced pulmonary thrombolysis. Rate and extent of thrombolysis were assessed with a gamma camera. Eighteen dogs were studied. Emboli increased mean pulmonary arterial pressure and decreased CO from 2.6 to 1.9 l/min (P less than 0.001). Subsequently, dogs were randomly divided into three groups: group 1 received 0.5 mg/kg of rtPA over 30 min; 30 min before the same dose regimen of rtPA, in the six group 2 dogs, mean CO was increased to approximately 3.25 l/min by opening one systemic arteriovenous fistula; in the six group 3 dogs, before rtPA, mean CO was increased to approximately 4.5 l/min by opening two or three fistulas. After embolization, CO remained low in group 1; the mean 2-h time-averaged CO was 1.8 l/min. CO was much higher in groups 2 and 3 (3.3 and 4.6 l/min, respectively; both P less than 0.001 compared with group 1; and P less than 0.001, group 2 vs. group 3). Compared with group 1, corresponding to the increased flow in groups 2 and 3, rate and extent of pulmonary thrombolysis significantly increased. These results indicate that an increase in flow per se augments rtPA-induced pulmonary thrombolysis. Also, because thrombolysis was similar between groups 2 and 3, these results define an upper limit to the flow-thrombolytic relationship with rtPA.

Animals↗
PubMed1991

Problems in the treatment of religious patients.

Members of religious groups are bound together by doctrine, ritual, and social organization. These factors also separate religious people from members of other groups or cultures. This division is apparent during interactions with other groups, and critical when members of religious groups are referred for help for psychiatric problems. In this paper we discuss four problems that therapists may encounter with strictly religious patients. Religious patients are often suspicious of secular therapists and therapy, and therapists too, may be influenced by their personal attitudes toward religion. Differentiating religious beliefs and rituals from delusions and compulsions is difficult for therapists ignorant of the basic tenets of that religion. Clinical examples of the four problems are presented from our work with patients from the ultra-orthodox Jewish community of North Jerusalem and we provide guidelines for their resolution. Therapists need a basic knowledge of the religion's doctrines and rituals, should assess patients using its terminology, and approach the patients through the social organization of their religious group. We consider that attention to these issues is vital for effective communication and assessment of strictly religious patients.

Adult↗
PubMed1991

Cryptosporidium in Bedouin and Jewish infants and children in southern Israel.

We conducted a 1-year prospective study in two clinics and a hospital in the Negev region of southern Israel to determine the epidemiological and clinical patterns of Cryptosporidium diarrhea among Jewish and Bedouin infants and children living in the same geographical area. A total of 612 episodes were studied: 398 in Bedouins and 214 in Jews, of which 449 occurred in patients with diarrhea and 164 in controls. Cryptosporidium was detected in 13 of 382 patients (3.4%) with diarrhea and in 1 of 138 controls (0.7%) (P = 0.078). In 5 of 13 Cryptosporidium-positive patients (38%) another pathogen was detected. No significant difference in Cryptosporidium detection rates was observed between Jews and Bedouins or between hospitalized or nonhospitalized patients. The frequency of Cryptosporidium detection did not differ significantly when three age-groups were compared (less than 6 months old, 7-12 and 13-36 months old). The rate of Cryptosporidium detection was similar among malnourished and well-nourished patients, as determined by weight-for-height percentiles. Cryptosporidium was detected more frequently during the summer months (8.3%) than during the rest of the year (1.2%) (P less than 0.001). Patients with Cryptosporidium diarrhea did not differ clinically from patients with other causes of diarrhea. However, they were characterized by the absence of fecal leukocytes. Cryptosporidium is not a rare cause of diarrhea in southern Israel. It is more prevalent during the hot and dry season and can be detected in a relatively high prevalence among very young infants. Its clinical features are indistinguishable from those of patients with non-cryptosporidial diarrhea.

Child, Preschool↗
PubMed1990

The fraud squad.

Explore the source record for details and available documents.

Biomedical Research↗
PubMed1990

Corn oil and mineral oil stimulate sham feeding in rats.

To determine the orosensory effects of oils on ingestion, we measured the 1-bottle intake of corn oil and of mineral oil during 30 minutes of sham feeding in rats that were food deprived overnight or nondeprived. Rats sham fed both oils. Food-deprived rats ingested significantly more of both oils than nondeprived rats. Rats discriminated corn oil from mineral oil and as little as 0.78% corn oil emulsion from water. When rats sham fed 8 dilutions of corn oil, intake was an inverted-U function of concentration with maximal intakes produced by 12.5%, 25% and 50% corn oil emulsions. Despite similar, sometimes equal, intakes of corn oil and mineral oil in 1-bottle tests, food-deprived and nondeprived rats showed a strong preference for corn oil in 2-bottle, sham-feeding, preference tests. The sensory mechanisms that mediate the oral effects of oil on intake and preference are not known, but the olfactory and trigeminal sensory systems are the most likely candidates. Further work is required to characterize the potency, sensitivity, and discriminability of the orosensory effects of oils, the mechanisms that mediate them, and their role in the control of fat intake.

Animals↗
PubMed1990

The potency of D-1 and D-2 receptor antagonists is inversely related to the reward value of sham-fed corn oil and sucrose in rats.

Intraperitoneal injection of 50 micrograms.kg-1 of the selective dopamine D-1 receptor antagonist, SCH 23390, significantly decreased sham feeding of 6% and 10% sucrose solutions, but not sham feeding of 100% corn oil. Intraperitoneal injection of raclopride, a D-2 antagonist, elicited a significant dose-dependent (200-400 micrograms.kg-1) decrease in sham intake of both sucrose concentrations and corn oil at doses that did not increase the latency to sham feed or produce overt motor impairment. The rank order of inhibitory potency for both SCH 23390 and raclopride was 6% sucrose greater than 10% sucrose greater than 100% corn oil. In a second experiment, we found that in 2-bottle preference tests, the rank order of preference for these three liquids was 100% corn oil greater than 10% sucrose greater than 6% sucrose. Assuming that preference measured the relative reward value of the liquids, the potencies of the two antagonists were inversely related to the reward value of the liquid that was sham fed. This result supports but does not prove the dopamine hypothesis of the positive reinforcing effect of orosensory stimulation by nutrients. In addition, the differential selectivity of the two antagonists for different classes of nutrients suggests that normal sensory and/or hedonic processing of sham-fed sucrose depends on stimulation of both D-1 and D-2 receptors, but the normal sensory and/or hedonic processing of sham-fed corn oil depends primarily, perhaps exclusively, on stimulation of D-2 receptors.

Animals↗
PubMed1990

Rotavirus diarrhea in Jewish and Bedouin children in the Negev region of Israel: epidemiology, clinical aspects and possible role of malnutrition in severity of illness.

We conducted a 1-year prospective study in the Negev region of southern Israel to determine the epidemiologic and clinical patterns of rotavirus diarrhea. A total of 605 patients were studied, 392 Bedouins and 213 Jews, 441 of whom had diarrhea (449 episodes) and 164 did not. Rotavirus was the most common organism detected in children with diarrhea (63 of 444; 14%) but was rarely found in controls (3 of 163; 2%) (P less than 0.001). In 22% (12 of 54) of the rotavirus-positive patients, at least one other organism was also detected. The rate of rotavirus detection decreased as age increased, from 18% in the first year to 8% in the third year of life. Hospitalization with rotavirus diarrhea occurred more frequently in the summer. However, during winter, when diarrhea was less prevalent in the community, the proportion of cases associated with rotavirus was higher. Compared with controls, malnourished children were more likely to be hospitalized. However, rotavirus was detected in similar proportions among well-nourished and malnourished cases with diarrhea. The most prevalent rotavirus serotype was type 1 (in 69%), followed by types 4 and 2 (18 and 13%, respectively). We estimated that during the study period, approximately 2% of all Bedouin infants vs. only 0.2% of Jewish infants were hospitalized with rotavirus disease in their first year of life. Clinical signs and symptoms and stool appearance were not useful in predicting rotavirus detection. Malnutrition seems to be an important indicator of disease severity, which may explain why the toll of rotavirus-associated morbidity and mortality is particularly high among children in developing countries.

Acute Disease↗
PubMed1990

Gene mapping in the idiopathic generalized epilepsies: juvenile myoclonic epilepsy, childhood absence epilepsy, epilepsy with grand mal seizures, and early childhood myoclonic epilepsy.

Idiopathic generalized epilepsies, i.e., juvenile myoclonic epilepsy (JME), childhood absence epilepsy, and epilepsy with grand mal [generalized tonic-clonic seizures (GTCS)], are the most common genetic epilepsies. Linkage studies using Bf, HLA serologic, and DNA markers by three independent investigators, one from Los Angeles and two from Berlin, have localized the JME locus to the short arm of chromosome 6 (6p). Because members of the same JME family have the same JME phenotype of childhood absence epilepsy, epilepsy with grand mal (GTCS) seizures, or early childhood myoclonic epilepsy (ECME), our observations give evidence for a single-locus etiology in 6p for JME and for at least some of the childhood absence seizures, epilepsy with grand mal (GTCS) seizures, and ECME. Studies should now address whether locus heterogeneity exists within childhood absence epilepsy, epilepsy with grand mal (GTCS) seizures, or ECME. Markers linked to JME (Bf, HLA serologic, and DNA markers in the DQ region) can be used to resolve etiologic heterogeneity. Using such markers, both linked and unlinked forms of phenotypes that are clinically indistinguishable may be detected and provide evidence for etiologic heterogeneity. Studies should also concentrate on narrowing the JME locus to 2 to 3 cm by screening families with recombinant events using RFLPs, candidate genes, and new expressed sequences on chromosome 6.

Adolescent↗
PubMed1990

Experimental boron neutron capture therapy for melanoma: systemic delivery of boron to melanotic and amelanotic melanoma.

The boron-containing melanin precursor analogue p-boronophenylalanine (BPA) has previously been shown to selectively deliver boron to pigmented murine melanomas when administered in a single intragastric dose. If boron neutron capture therapy is to become a clinically useful method of radiation therapy for human malignant melanoma, the boron carrier must be capable of delivering useful amounts of boron to remote tumor sites (metastases) and to poorly pigmented melanomas. We have now determined the ability of BPA to accumulate in several nonpigmented melanoma models including human melanoma xenografts in nude mice. The absolute amount of boron in the nonpigmented melanomas was about 50% of that observed in the pigmented counterparts but was still selectively concentrated in the tumor relative to normal tissues in amounts sufficient for effective neutron capture therapy. Single intragastric doses of BPA resulted in selective localization of boron in the amelanotic Greene melanoma carried in the anterior chamber of the rabbit eye and in a pigmented murine melanoma growing in the lungs. The ratio of the boron concentration in these tumors to the boron concentration in the immediately adjacent normal tissue was in the range of 3:1 to 4:1. These distribution studies support the proposal that boron neutron capture therapy may be useful as a regional therapy for malignant melanoma.

Animals↗
PubMed1990

Mental illness and religious change.

Over the last 20 years there has been a revival of interest in orthodox Judaism in Israel. In an area of Jerusalem with a large concentration of academies of study for 'baalei teshuva' (those who have undergone change to orthodox Judaism), it was noted that 12.6 per cent of referrals to the community mental health centre were newly religious. These referrals tended to have schizophrenia or severe personality disorders and were less likely than other referrals to have anxiety, depressive or adjustment disorders. Most of the newly religious referrals had psychiatric problems prior to becoming religious. Subsequent to religious change, many married and started a family before their psychiatric referral. The link between religious change and mental illness is explored.

Adaptation, Psychological↗
PubMed1990

Intraduodenal infusions of fats elicit satiety in sham-feeding rats.

The satiating effect of duodenally administered fats was investigated with intraduodenal infusions of Intralipid in sham-feeding rats. Intralipid rapidly inhibited sham feeding and elicited the behavioral sequence of satiety. The satiating potency of Intralipid infusions in concentrations of 0.125-1 kcal/ml was a function of the concentration infused. The time course for Intralipid-induced satiety showed that fats inhibited feeding and led to the behavioral sequence of satiety within 15 min after the infusions began. This time course is evidence for a preabsorptive site of action to the small intestine. To test this hypothesis we added the local anesthetic tetracaine to Intralipid infusions. Tetracaine significantly reduced the satiating potency of Intralipid infusion. This result supports the hypothesis of a preabsorptive site of action. We also tested the specificity of intraduodenal Intralipid for feeding by administering Intralipid to rats that were sham drinking. The effect of Intralipid was relatively specific because the threshold concentration of Intralipid necessary to inhibit sham drinking was higher than the threshold for sham feeding. In addition, at superthreshold concentrations, Intralipid inhibited sham drinking less than sham feeding and elicited different behaviors than were observed during sham feeding.

Animals↗
PubMed1990

Effect of fourth ventricular neuropeptide Y and peptide YY on ingestive and other behaviors.

We studied the effect of fourth intracerebroventricular administration of neuropeptide Y (NPY) and peptide YY (PYY) on ingestive and other behaviors in awake nondeprived rats. Injection of NPY or PYY into the fourth ventricle produced a significant dose-related increase in food intake and reduction in the latency to eat. PYY was more potent than NPY in increasing food intake and decreasing latency to eat, suggesting that PYY-preferring receptors sensitive to the orexigenic effects of NPY and PYY exist in the hindbrain. In addition, both peptides increased water intake when food was present but not when food was absent, suggesting that a neural substrate supporting a direct action of NPY and PYY on water intake is not present in the hindbrain. In time sampling of behaviors occurring during a 90-min feeding test, we found that both peptides increased the time spent eating and reduced grooming. In addition PYY, but not NPY, reduced apparent sleep and increased exploratory activity. This suggests that PYY, but not NPY, influences a hindbrain neural substrate involved in sleep and activity.

Animals↗
PubMed1990

Obese and lean Zucker rats differ in preferences for sham-fed corn oil or sucrose.

Obese Zucker rats show greater preference for fatty foods in dietary selection studies than do lean rats. We wished to evaluate the preference for dietary fats in Zucker rats in the absence of postingestive cues. Zucker rats (6 lean and 6 obese) were fitted with gastric cannulas for sham feeding. All sham-feeding tests lasted for 30 min. On training days, rats were sham fed 100% corn oil or, on alternate days, rats were sham fed various concentrations of sucrose in volumes yoked to intakes of corn oil. On preference test days, rats were offered 100% corn oil and one sucrose concentration simultaneously for sham feeding. During preference tests, obese rats preferred 100% corn oil to 10% sucrose, whereas lean rats preferred 10% sucrose to 100% corn oil. Obese rats equally preferred 17.5% sucrose and 100% corn oil, whereas lean Zucker rats equally preferred 2.5% sucrose and 100% corn oil. When sucrose concentration was increased to 20% both obese and lean Zucker rats preferred sucrose to 100% corn oil. These results combined with our previously reported results showing that intraduodenally administered fats do not differ in satiating potency for obese and lean Zucker rats (6) strongly suggest that the preference of obese rats for fatty foods is largely mediated by orosensory mechanisms.

Animals↗
PubMed1990

Thrombolytic therapy in canine pulmonary embolism. Comparative effects of urokinase and recombinant tissue plasminogen activator.

We compared thrombolytic and pulmonary hemodynamic effects of recombinant tissue plasminogen activator (rtPA) and urokinase (UK) in canine micropulmonary thromboembolism. Dogs were embolized with radioactive autologous blood clot to increase mean pulmonary artery pressure (from 13 to 34 mm Hg, p less than 0.005) and decrease cardiac output (2.5 to 1.6 L min, p less than 0.005). Four groups of six dogs were treated. We employed two doses of UK, 30,000 U/kg (UK30) and 60,000 U/kg (UK60), and two doses of rtPA, 1 mg/kg (rtPA1) and 2 mg/kg (rtPA2). Drugs were infused over 15 min. Rate and extent of pulmonary thrombolysis were assessed by continuously counting over both lung fields with a gamma camera. Compared with treatment with UK, both rtPA regimes significantly increased thrombolysis. Mean total pulmonary thrombolysis was 14 and 23% with UK30 and UK60, respectively, and 35 and 43% with rtPA1 and rtPA2. Corresponding to the increased thrombolysis, pulmonary hemodynamics improved most with rtPA. From 90 min to 3 h, pulmonary artery pressure was significantly lower with both rtPA regimes than with either UK regime. These results indicate, at least in the model employed, that compared with treatment with UK, pulmonary thrombolysis and corresponding hemodynamic improvement are greatest with rtPA.

Animals↗