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Biomedical subjects

A S Bloom

Publications and source records attributed to A S Bloom.

53 records · Page 3Linked to original sources
PubMed1981

Adrenalectomy reverses the effects of delta-9-THC on mouse brain 5-hydroxytryptamine turnover.

Acute administration of certain cannabinoids, including delta 9-tetrahydrocannabinol (delta 9- THC), resulted in elevated levels of plasma corticosterone in mice. The rank order potency of these cannabinoids is the same as others have reported using behavioral tests. The maximally effective dose of delta 9-THC (30 mg/kg) in this test also increased the amount of 3H-tryptophan found in the brains of mice given an intravenous injection of 3H-tryptophan 10 min prior to decapitation. This effect was associated with an increase in the amount of 3H-5-hydroxytryptamine synthesized during the pulse period. Adrenalectomy was found to inhibit these effects of delta 9-THC. The possibility that corticosterone may mediate the effects of delta 9-THC on tryptophan disposition and metabolism is discussed.

Adrenalectomy↗
PubMed1980

WISC-R Verbal-Performance IQ discrepancies: a comparison of learning disabled children to the normative sample.

Compared the WISC-R Verbal-Performance IQ discrepancies of learning-disabled children (N = 100) and of the normative sample. There were frequent occurrences of statistically significant discrepancies in both groups, as well as similar mean discrepancy scores and distributions of Verbal greater than Performance and Performance greater than Verbal patterns. It was concluded that without clinical evidence to suggest otherwise, it cannot be assumed automatically that child's discrepancy score, unless of extreme magnitude, is related to the learning disability itself. The importance to clinicians of making both normative and statistical interpretations of WISC-R discrepancy scores was stressed.

Adolescent↗
PubMed1980

Interaction of ambient temperature with the effects of delta 9-tetrahydrocannabinol on brain catecholamine synthesis and plasma corticosterone levels.

The effects of delta 9-tetrahydrocannabinol (THC) on body temperature, catecholamine synthesis and plasma corticosteroid levels were examined in the mouse at ambient temperatures of 31 degrees, 20 degrees and 10 degrees C in order to study the role of hypothermia in the THC's other actions. THC produced hypothermia at 10 degrees and 20 degrees C, but not at 31 degrees C. Dose related increases in dopamine and norepinephrine synthesis rates and plasma corticosterone levels were produced by THC at both 31 degrees and 20 degrees C. The effects of THC at 10 degrees C were biphasic. These data indicate that the effects of THC on brain catecholamines are not a result of drug induced hypothermia and may be a result of a direct action on neurons.

Animals↗
PubMed1978

A comparison of some pharmacological actions of morphine and delta9-tetrahydrocannabinol in the mouse.

The effects of morphine and delta9-tetrahydrocannabinol(THC)on the tail-flick reflex, body temperature, and catecholamine synthesis were examined in the mouse in order to compare their effects in a single species and strain under uniform conditions. Naloxone antagonism of THC and cross-tolerance between morphine and THC were also studied. Both morphine and THC produced antinociception, hypothermia, and increased catecholamine synthesis at 30 min after s.c. injection. Morphine produced greater increases in dopamine synthesis and was a more potent antinociceptive agent, while THC produced greater increases in norepinephrine synthesis and was a more potent hypothermic agent. Naloxone pretreatment (1 mg/kg) partially antagonized the hypothermia and increase in catecholamine synthesis produced by THC. There was also cross-tolerance between morphine and THC, but it was asymmetric in that THC-tolerant animals were cross-tolerant to only the hypothermic action of morphine and morphine-tolerant animals cross-tolerant to only the antinociceptive action of THC.

Analgesics↗
PubMed1978

The assessment of developmentally disabled children with the WISC-R, Binet and other tests.

Administered the WISC-R, Revised Stanford-Binet, Bender, VMI, and WRAT to 50 children referred for a multidisciplinary evaluation of developmental disabilities. The correlations among the various WISC-R measures (Standard Scores and IQs) and Binet IQ were significant, with relatively strong relationships among the Binet IQ and those WISC-R subtests that require concentration, short-term auditory memory, visual-motor integration, and the acquisition of new learning. Data showed that the Binet MA correlated as well or better with the other tests than did the various scores from the WISC-R.

Bender-Gestalt Test↗
PubMed1977

A comparison of the Stanford-Binet abbreviated and complete forms for developmentally disabled children.

Three abbreviated versions of the Stanford-Binet were reviewed and compared for 50 children with developmental disabilities. The children ranged in age from 6 years - 0 months to 15 years - 11 months. While the IQs obtained from the abbreviated forms correlated highly with the complete Binet IQ, it was felt that the 2-item test yielded too many "misses" both in terms of IQ and classification to be of significant value for use with developmentally disabled children. Although the Terman and Merrill 4-item and Wright versions both yielded considerable "misses" in classification, they were believed to be of definite value to the time-harried examiner. Caution was advised, however, in the use of abbreviated-form IQs as a basis for important diagnostic decisions.

Adolescent↗
PubMed1977

Effects of d-amphetamine and strychnine on cycloheximide- and diethyldithiocarbamate-induced amnesia in mice.

Groups of C57BL/6J mice were administred cycloheximide (CYC) 30 min before or immediately after training on a passive avoidance task and tested 72 hr later. Some CYC-pretreated groups were given strychnine or d-amphetamine (d-amp) immediately after training and others were given d-amp 1 hr after training. Other groups were given diethyldithiocarbamate (DDC) at various times before or after training. Some DDC-pretreated groups were gived-amp or strychnine as described above for CYC groups. Immediate posttraining administration of 5 mg/kg d-amp, but not strychnine, prevented amnesia in CYC-pretreated mice. The DDC induced an apparent amnesia when administered from 30 min before training to 3 hr after training. Posttraining administration of d-amp or strychnine did not prevent DDC-induced amnesia. These results are discussed in relation to previous suggestions that CYC- and DDC-induced amnesia may be the result of a functional impairment of catecholamine neurotransmitter systems by these drugs.

Amnesia↗
PubMed1977

9-nor-9beta-hydroxyhexahydrocannabinol, a cannabinoid with potent antinociceptive activity: comparisons with morphine.

The effects of (+/-)9-nor-9beta-hydroxyhexahydrocannabinol (beta-HHC) on tail-flick test activity and the accumulation of newly synthesized dopamine and norepinephrine were studied in the male albino mouse. The same parameters were also studied in naloxone-pretreated and morphine-tolerant mice. beta-HHC was about equipotent with morphine in the mouse tail-flick (ED50 = 7.12 mg/kg). The cannabinoid also produced dose-dependent increases in the accumulation of newly synthesized DA and NE. Pretreatment with 2 mg/kg of naloxone antagonized both the tail-flick activity and blocked the increases in catecholamine synthesis produced by beta-HHC. Cross-tolerance between beta-HHC and morphine did not exist in regard to either tail-flick activity or increased catecholamine synthesis. These studies suggest that beta-HHC may share some properties with the narcotic analgesics but that significant differences exist. Furthermore, these studies offer further evidence for the involvement of catecholamine containing neurons in the central mediation of the tail-flick response.

Analgesics↗
PubMed1976

The correlation between antinociceptive activity of narcotics and their antagonists as measured in the mouse tail-flick test and increased synthesis of brain catecholamines.

The effects of several narcotics, narcotic antagonists-analgesics and narcotic antagonists on the synthesis of dopamine and norepinephrine in mouse brain were estimated and related to their activity in the tail-flick test. Catecholamine synthesis was estimated by measuring the accumulation of 3H-dopamine and 3H-norepinephrine formed from an injection of 3H-tyrosine. Morphine produced dose-related increases in both tail-flick activity and catecholamine synthesis. Each of the narcotic analgesics produced a significant increase in catecholamine synthesis 30 minutes after the subcutaneous injection of an antinociceptive dose (ED80). Under these same conditions, drugs which are inactive in the tail-flick test, such as pentazocine, produced a decrease in catecholamine synthesis and cyclazocine; naloxone and naltrexone were without significant effect. However, cyclazocine, which was inactive in the tail-flick test and did not alter catecholamine synthesis 30 minutes after administration, demonstrated tail-flick activity and produced increased catecholamine synthesis 2 minutes after its administration. Morphine was devoid of either activity 2 minutes after administration. Similarly, at 2 hours after the administration of a dose of morphine (10 mg/kg) that was active in the tail-flick test and increased catecholamine synthesis at 30 minutes, neither tail-flick activity nor increased catecholamine synthesis was observed. Naloxone blocked both the antinociceptive action and the increased catecholamine synthesis produced by both morphine and methadone. The results of these studies indicate that a correlation exists between tail-flick activity of narcotic-like drugs and their ability to increase catecholamine synthesis. These data support the hypothesis that brain catecholamines may be involved in the central mediation of the tail-flick response and other actions of the narcotic analgesics.

Analgesics, Opioid↗
PubMedDate not supplied

Effects of pyrethroid insecticides on operant responding maintained by food.

The pyrethroids are potent insecticides with low concomitant mammalian lethality when compared with other major insecticides. While high doses can lead to hyperactivity, tremors, convulsion and death, low doses have not been as well studied. Since operant behavior can be a sensitive measure of CNS function, male Holtzman rats were trained on a VR25 schedule maintained by 45 mg food pellets. Rats were injected IP with one of four different technical grade pyrethroids: permethrin, allethrin, deltamethrin and fenvalerate. All agents were effective in reducing operant responding and did so in a dose-dependent manner at levels 10 to 100 times below their LD50 values. Time course studies indicated a relatively short duration of action for the Type I agents of less than 60 min for permethrin and 15 min for allethrin. Type II agents were generally effective for greater than 60 min. Results of these studies indicate that operant responding maintained by food is a sensitive measure of the behaviorally disruptive effects of subconvulsive doses of pyrethroids.

Allethrins↗
PubMedDate not supplied

Leukocyte hexokinase activity in aging and Alzheimer disease.

We determined the effects of clinical variables on hexokinase (HK) activity in leukocytes from Alzheimer's disease (AD) patients and controls. Age accounted for 51% of the variance in HK activity in the young and 23% in the old. Duration of illness in both familial and sporadic AD accounted for HK levels by 32 and 38%, respectively. Hexokinase activity increases with age and does not discriminate between familial and sporadic AD.

Adult↗
PubMedDate not supplied

Pyrethroid effects on operant responding and feeding.

The effects of permethrin, its cis and trans isomers, and deltamethrin on operant behavior and food intake were examined. Male Sprague-Dawley rats were trained to respond on a VI20 second schedule of food reinforcement. Rats were injected intraperitoneally with pyrethroids or their Emulphor vehicle 20 minutes prior to testing. Technical grade permethrin (15-60 mg/kg) produced a dose-related decrease in operant response rate. The 60 mg/kg dose decreased rates by 60%. Lower doses of cis-permethrin (30 mg/kg) and deltamethrin (2 mg/kg) also produced significant decreases in response rate. A 30 mg/kg dose of trans-permethrin was without effect. Food intake was also measured for 1.5 and 24 hour periods after tech-permethrin treatment. Food intake was decreased over both intervals by the 60 mg/kg dose. The results of these studies indicate that subconvulsive doses of pyrethroid insecticides can have significant effects on learned behavior and food intake.

Animals↗