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Biomedical subjects

H Rosenkrantz

Publications and source records attributed to H Rosenkrantz.

At least 37 records · Page 2Linked to original sources
PubMed1981

Raeder syndrome associated with lesions of the internal carotid artery.

The authors describe 3 patients with Raeder syndrome who also had lesions of the internal carotid artery in the region of the ascending sympathetic chain. One patient apparently had weakening of the artery wall, caused by extension of inflammatory disease, with hemorrhage brought on by exertion; another patient had a psuedoaneurysm possibly related to biopsy or irradiation, while a third had an aneurysm which may have been caused by a carotid artery dissection at the time of a whiplash injury many years earlier.

Adult↗
PubMed1980

Cannabinoid-induced hormone changes in monkeys and rats.

Previous findings at various laboratories indicated that cannabinoids distribute to sexual behavior centers in the brain, and endocrine aberrations have consistently been observed in animals treated with cannabis constituents. Subacute and chronic studies were performed to monitor hormone changes in rats and monkeys exposed to marihuana smoke or pure cannabinoids. In oral studies, young Fischer rats of both sexes were given delta 9-tetrahydrocannabinol (delta 9-THC) doses of 2, 10, or 50 mg/kg for 14--180 d and pregnant rats received 1, 5 or 10 mg/kg during gestation and lactation. Other male rats were exposed to marihuana smoke at delta 9-THC doses of 2 or 4 mg/kg for 14 d. Rhesus monkeys of either sex were given oral cannabidiol doses of 30, 100, and 300 mg/kg for 90 d. Serum pituitary, steroid, and thyroid hormone levels were determined by radioimmunoassay. Marihuana smoke (and oral delta 9-THC) depressed testosterone 20--30% and triiodothyronine 17--29%. In pregnant rats, small doses of delta 9-THC suppressed luteinizing hormone, but larger doses elevated both follicle-stimulating hormone and estrogens (approximately 50--100%) without affecting progesterone levels. Prolonged oral administration of delta 9-THC to young rats tended to increase gonadotropins, to which tolerance developed in males. Cannabidiol-treated monkeys responded with slight elevations in luteinizing hormone and follicle-stimulating hormone in males, whereas steroid hormones were essentially unchanged for both sexes. Hormone imbalance may explain cannabinoid-induced embryotoxicity and impaired gonadal function.

Administration, Oral↗
PubMed1980

Long-term controlled delivery of levonorgestrel in rats by means of small biodegradable cylinders.

Hormone release rates from biodegradable cylindrical implants consisting of a physical matrix of [14C]levonorgestrel and copolymers of [3H]lactic and glycolic acids have been monitored in rats. Two copolymers were evaluated: one consisted of 90 parts L-lactide/10 parts glycolide (90L/10G) containing 33 or 50% hormone by weight, and the other of 50 parts DL-lactide/50 parts L-lactide (50DL/50L) containing 50% hormone. For each system, 4-6 rods (0.8 x 16 mm) providing 19 mg of steroid per rat were subcutaneously implanted into the scapular regions of 5 rats, and 14C and 3H in faeces and urine were determined weekly for 90-724 days. An initial burst of hormone release, peaking at approximately 90 microgram day-1, occurred in the first two weeks. This was followed by an approximately 10-30 microgram day-1 for the 90L/10G system containing 33% hormone, a more uniform rate of approximately 25 microgram day-1 for the 50DL/50L system and the highest rate of approximately 40 microgram day-1 for the 90L/10G system containing 50% hormone. 3H and 14C in residual implants of 90L/10G with 33% hormone removed from animals dying of natural causes during the test were assayed. For this system 3H activity decreased by over 50% within 250 days, compared with < 25% loss in 14C activity. The amounts of 3H and 14C released were similar over much of the subsequent test period. At the end of the test both polymer and drug were essentially depleted. All animals with the 50DL/50L system died late in the test period. Between days 609 and 724 from 13.7-27.2% initial 14C and from 10.0-22.1% initial 3H was measured in recovered rods. Microscopic inspection of recovered rods showed a loss of core material and tissue encapsulation. There were no signs of local tissue irritation or systemic toxicity.

Animals↗
PubMed1980

Assessment of tolerance to immunosuppressive activity of delta 9-tetrahydrocannabinol in rats.

Immunosuppression evoked by delta 9-tetrahydrocannabinol (delta 9-THC) has been a consistent finding in rats but the development of tolerance to this phenomenon has not been explored. Therefore, Fischer rats of both sexes were orally given delta 9-THC at 6 or 12 mg/kg or sesame oil as vehicle control for 5-26 days before and after I.P. antigenic stimulation with sheep red blood cells (SRBC). delta 9-THC doses were relevant to those of man and produced mild CNS-inhibition followed by CNS-stimulation, tolerance developing to both behavioral phases. The primary immune response was evaluated by determining splenic antibody-forming cells (AFC), hemagglutinin (HT) and/or hemolysin (HS) titers. Simultaneous administration of delta 9-THC and SE induced dose-related splenic atrophy and reduced AFC proliferation as well as HT and HS responses. These changes were not elicited by sesame oil. Tolerance did not develop to immunosuppression during 26 days of cannabinoid treatment. delta 9-THC given 3 days post SRBC inoculation induced immunosuppression at 12 but not 6 mg/kg. Immunosuppression was directly related to delta 9-THC rather than to non-specific debilitating factors since body weights are stable. The inductive phase of the primary immune response was most sensitive to impairment although the reproductive phase was also affected at the high dose level.

Animals↗
PubMed1980

Iron tissue and excreta changes induced by ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid) in dogs.

The use of EDBPHA as a potential iron chelator in cases of hemochromatosis provided impetus for investigating its toxicology. Because a reddish coloration of excreta was observed during subchronic administration of the drug to dogs, measurements of iron concentrations in blood, excreta, and hematopoietic tissues were made. Groups of beagle dogs of both sexes were injected i.v. with EDBPHA doses of 6, 12, or 18 mg/kg or were given capsules containing doses of 30, 100, or 240 mg/kg for 14 days. Control dogs received either saline i.v. or empty gelatin capsules orally. In addition to the monitoring of toxicological effects, iron levels in plasma, urine, feces, liver, spleen, and kidney were monitored before drug, at the end of treatment, and after a 16-day recovery period. In the absence of hemoglobin and hematocrit changes, i.v. EDBPHA reduced renal iron 40% and hepatic iron 15% to 25% without altering splenic iron. Serum iron rose 34% to 54%, urinary iron 80% to 119%, and fecal iron 23% to 41%. Oral EDBPHA did not induce changes in tissue iron or excreta iron, but serum iron was increased 22% to 29%. These alterations in iron concentrations were transient and may be related to iron redistribution and inactivation of drug by liver.

Animals↗
PubMed1979

The selection and evaluation of new chelating agents for the treatment of iron overload.

A large-scale systematic evaluation of potential iron chelators for the treatment of hemosiderosis was conducted. The compounds were identified and evaluated using a hypertransfused mouse screen in which deferrioxamine B was a standard. This screen was designed to measure iron depletion in the tissues as well as iron excretion. Groups of 10 previously hypertransfused BDF1 male mice received a single daily i.p. injection of either vehicle, standard, or test compound for 7 days. Iron in daily urine pools and individual spleen and liver homogenates was determined by atomic absorption. More than 70 chelators were evaluated, including natural and synthetic hydroxamic acids, phenols, catechols and tropolones known to have a high affinity for iron (III) in vitro. Ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid) was shown to be considerably more effective than deferrioxamine B (i.p.) and, in addition, was orally active. Factors determining the efficacy of this and other chelating agents are discussed.

Animals↗
PubMed1976

Volumetric instillation of fixatives and inert substances into mouse lungs.

Mouse lungs were instilled with various fixatives to establish the optimum volume necessary to fix the lung without distortion and to compare the efficacy of the fixatives. Fixation with either Stieve's or Bouin's fluid was found preferable to 2.5% and 5% glutaraldehyde, 4% neutral buffered formalin, and to a mixture of formalin and Stieve's fixative. In addition, a comparison was made between diluted Ames O.C.T. Compound and 4% aq. gelatin as supportive substances for unfixed lungs in preparation of cryostat sections and for histochemistry. A 1:2 dilution of O.C.T. was found to be superior to 4% gelatin in preparative, cutting and adhesive properties. The optimal instilled volume for mouse lungs was found to be 0.1 ml for every 7 grams of body weight, introduced at a rate of 0.1 ml per 10 seconds.

Acid Phosphatase↗
PubMed1975

Effects of delta-9-tetrahydrocannabinol administered subcutaneously to rabbits for 28 days.

Subcutaneous (s.c.) administration of delta-9-tetrahydrocannabinol (delta-9-THC) to rabbits produced dose-related cumulative toxicity. Five groups of three New Zealand albino rabbits each received 28 daily treatments with isotonic saline, sesame oil of 15.9, 45.0 or 153.4 mg/kg/day of delta-9-THC dissolved in sesame oil. Dose-related dermal responses included erythema, edema, ulceration and nodule formation. Some of the granulomatous nodules contained an oily substance and exhibited liquefactive necrosis. The severities of erythema and ulceration were generally maximal during the first week of treatment, but edema and nodule formation were most severe after days 12 and 14, respectively. All rabbits survived treatment, but body weights, liver weights and liver glycogen levels were decreased in a dose-related manner. Maximal body weight effects occurred after day 19. Hemochemical changes occurred only in rabbits treated with 153.4 mg/kg/day and included decreased blood sugar and alkaline phosphatase, and increased serum potassium. Hematology parameters were normal throughout the treatment period. No drug-related pathological lesions occurred in internal organs. The cumulative body weight changes, significantly decreased hepatic glycogen levels and reduced blood sugar and alkaline phosphatase values may have indicated drug-induced metabolic changes.

Animals↗