The effect of orally and rectally administered delta 9-tetrahydrocannabinol on spasticity: a pilot study with 2 patients.

Multiple doses of delta 9-tetrahydrocannabinol (THC) capsules (Marinol) and THC hemisuccinate suppositories were administered in 24-hour intervals to 2 patients with organically caused spasticity. After oral doses of 10-15 mg THC, peak plasma levels from 2.1 to 16.9 ng/ml THC and 74.5 to 244.0 ng/ml 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (THC-COOH, major THC metabolite) were measured by GC/MS within 1-8 h and 2-8 h, respectively. After rectal doses of 2.5-5 mg THC, peak plasma levels from 1.1 to 4.1 ng/ml THC and 6.1 to 42.0 ng/ml THC-COOH were measured within 2-8 h and 1-8 h, respectively. The bioavailability resulting from the oral formulation was 45-53% relative to the rectal route of administration, due to a lower absorption and higher first-pass metabolism. The effect of THC on spasticity, rigidity, and pain was estimated by objective neurological tests (Ashworth scale, walking ability) and patient self-rating protocols. Oral and rectal THC reduced at a progressive stage of illness the spasticity, rigidity, and pain, resulting in improved active and passive mobility. The relative effectiveness of the oral vs. the rectal formulation was 25-50%. Physiological and psychological parameters were used to monitor psychotropic and somatic side-effects of THC. No differences in the concentration ability, mood, and function of the cardiovascular system could be observed after administration of THC.

Presence of growth hormone-releasing hormone-like immunoreactivity in human tumors: characterization of immunological and biological properties.

The distribution and physical and biological properties of GH-releasing hormone-like immunoreactivity (GHRH-IR) in human tissues and tumors was investigated using a specific GHRH RIA, gel chromatography, immunoaffinity chromatography, and bioassay with cultured rat anterior pituitary cells. Variable concentrations of GHRH-IR, ranging from 1.4-39.0 ng/g wet wt, were found in normal liver, lung, placenta, and pancreas. In the latter tissue, however, a different chromatographic profile and a marked decrease in GHRH-IR after immunoaffinity occurred, suggesting that GHRH-IR in pancreatic extracts is not native GHRH. In all tumors examined (n = 35) GHRH-IR could be detected, and four tumors (three carcinoids and one jejunal carcinoma) contained a very high amount of GHRH-IR (greater than 1000 ng/g wet wt). Affinity chromatography of tumor extracts led to a significant loss (greater than 50%) of GHRH-IR in nine tumors. The four tumors containing large amounts of GHRH-IR were obtained from two patients with active acromegaly and two patients who had no clinical evidence of acromegaly. Using antibodies with different specificities for GHRH-(1-44) and GHRH shortened at the C-terminus, varying concentrations of GHRH-(1-44) in these tumors were found, ranging from 10-87% of the total GHRH-IR. The biological activity of GHRH in the four tumor extracts was similar to that of synthetic GHRH alone or GHRH added to control tissue subjected to extraction. These results demonstrate the presence of GHRH-IR in the majority of normal tissues and tumors, which, though they may produce large amounts of biologically active GHRH, do not always lead to acromegaly.

Interaction of clonidine and GHRH on GH secretion in vivo and in vitro.

UNLABELLED: To investigate the mechanism by which clonidine stimulates GH-secretion in vivo and in vitro, we studied its interaction with GHRH. In vivo: eight or six normal male subjects were submitted to five protocols: (1) 150 micrograms clonidine orally followed by 50 micrograms GHRH 1-44 i.v. 2 h later, (2) 50 micrograms GHRH 1-44 i.v. followed by 150 micrograms clonidine orally 2 h later, (3) 150 micrograms clonidine orally followed by GHRH i.v. 30 min later, (4) 300 micrograms clonidine orally followed by 50 micrograms GHRH i.v. 3 h later and (5) 50 micrograms GHRH i.v. followed by 300 micrograms clonidine orally 90 min later. In vitro: Rat anterior pituitary cells were coincubated with clonidine (10(-11), 10(-9), 10(-7) and 10(-5) M) and GHRH (0.005, 0.05, 10 nM) for 4 h. RESULTS: 150 micrograms clonidine alone does not stimulate GH-secretion. Furthermore, the GH-increase was not significantly different when GHRH bolus was given before, after or together with clonidine. When 300 micrograms clonidine was given before GHRH GH-levels were significantly higher (max 28.6 +/- 8.0 mU/l) at 90 min, compared to when clonidine was given after GHRH (max 7.8 +/- 3.6 mU/l). The GHRH bolus after clonidine led to a significantly lower GH-increase (max 31.6 +/- 17.0 mU/l) compared to the GHRH-induced GH-increase (max 47.2 +/- 13.0 mU/l) before clonidine. In vitro, clonidine had no stimulatory effect on GHRH-stimulated GH secretion. These findings are compatible with clonidine leading to stimulation of GH by inducing endogenous GHRH release.

Phenotype-associated changes in the effects of 1,25-dihydroxyvitamin D3 on alkaline phosphatase and bone GLA-protein of rat osteoblastic cells.

The effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on alkaline phosphatase (AP) activity and the synthesis of gamma-carboxy-glutamic acid containing protein (BGP) were compared in phenotypically distinct cloned cell lines derived from the osteoblast-like rat osteogenic sarcoma line ROS 17/2-8. 1,25(OH)2D3 stimulated AP activity and BGP synthesis in phenotypes which exhibited relatively low basal AP activity and high basal BGP levels. In contrast 1,25(OH)2D3 inhibited AP activity in phenotypes that exhibited high basal AP activity. The latter cells had undetectable BGP levels and the synthesis of this protein failed to respond to the 1,25(OH)2D3 stimulus. In the cells that responded to 1,25(OH)2D3 with an increase in AP activity the effect of the hormone on AP could be blocked by actinomycin-D. However in the cells that responded to 1,25(OH)2D3 with inhibition of AP the effect of the hormone on AP was not influenced by actinomycin-D. The directly opposite effects of 1,25(OH)2D3 on the AP activity of the respective clones did not change qualitatively at different stages of culture and could not be accounted by differences in the 1,25(OH)2D3 receptor status nor by different effects of the hormone on cell proliferation. These data raise the possibility that the response of AP to 1,25(OH)2D3 in osteoblastic cells depends on their state of phenotypic differentiation. The stimulatory effect of the hormone in low AP-producing cells might be related to differentiation promoting properties of 1,25(OH)2D3. The inhibitory effect of 1,25(OH)2D3 on AP, unlike the stimulatory effect of the hormone does not appear to be mediated by the classical mechanism of 1,25(OH)2D3 action on the genome and might be associated with dedifferentiated osteoblastic cells.

[Rett syndrome: a progressive neurological syndrome in girls]. / Rett-Syndrom: ein progredientes neurologisches Syndrom bei Mädchen.

Rett syndrome, named after Rett's first description in 1966, evolves typically in 3 stages: after normal early psychomotor development up to the age of 6-24 months, stagnation and regression occur over a few months resulting in severe dementia, loss of speech, of social response and of purposeful hand use. This is accompanied by particular stereotyped hand movements and usually also by deceleration of head growth. The further course is often stable for a prolonged period, or only slowly progressive. Common features are seizures, episodic hyperpnea, scoliosis, spasticity and vasomotor disturbances of lower limbs. Rett syndrome has been observed only in girls, all cases (with 2 exceptions) being sporadic. This is probably explained by a X-linked dominant new mutation lethal in males. The pathogenesis is still unknown: no consistent metabolic, morphologic or neuroradiologic abnormalities have been found. According to some epidemiologic investigations, Rett syndrome affects about 1:15,000 girls and is thus responsible for a considerable proportion of severely retarded girls. Within one year the authors have retrospectively diagnosed 15 cases, which is assumed to represent only about a third of patients in Switzerland.

Mechanism of action of 1,25-dihydroxyvitamin D3-induced stimulation of alkaline phosphatase in cultured osteoblast-like cells.

1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] stimulates the alkaline phosphatase of rat and human osteoblast-like cells in culture. Here the mechanism of this effect was investigated using the rat osteogenic sarcoma cell line ROS 17/2-8. We found that 50% maximum alkaline phosphatase stimulation is elicited by 1,25(OH)2D3 at 7 X 10(-10) M. The concentration of serum in the culture medium influences inversely the effective 1,25(OH)2D3 concentration. Increased alkaline phosphatase appears after a lag period of cell exposure to 1,25(OH)2D3 which is between 8 and 24 h; during 96 h culture in the presence of 1,25(OH)2D3 the enzyme activity continues to rise. Cycloheximide (0.1-1 micrograms/ml) added in the cultures for 3 days or actinomycin-D (1-30 ng/ml) added for 24 h inhibit the 1,25(OH)2D3 effect on alkaline phosphatase in a dose-dependent fashion; withdrawal of cycloheximide restores the responsiveness of cells to 1,25(OH)2D3 completely, but withdrawal of actinomycin-D restores cell responsiveness only partially. These findings suggest that 1,25(OH)2D3-induced stimulation of alkaline phosphatase in the osteoblast-like cells involves genome activation and de novo protein synthesis.

Superfusion of dissociated pancreatic islet cells attached to Cytodex beads.

Pancreatic islets of neonatal were dissociated by collagenase and cultured for 3 days in the presence of Cytodex beads to allow attachment of the cells to these microcarriers. The bead-attached cells were packed in columns and superfused with a low bicarbonate medium using the same method that we had originally developed for dissociated anterior pituitary cells of the rat. The secretion of insulin, somatostatin, and glucagon by the cells was monitored by radioimmunoassays. The cells in the superfusion system responded as expected from experiments with islet and monolayer cultures of rat pancreas in vitro and in vivo. Increasing glucose concentrations in the superfusion medium increased the release of insulin and somatostatin (SS), whereas glucagon secretory rates remained constant or decreased. A dose-response curve was established between insulin release and D-glucose in which the ED50 of D-glucose for insulin was found between 1.5 and 2 mg/ml. The phosphodiesterase inhibitor, 3-isobutyl-methylxanthine (IBMX), significantly potentiated the insulin response to glucose. Various secretagogues such as IBMX, 8-bromo cyclic AMP, and L-arginine increased insulin, somatostatin, and glucagon secretory rates in an expected manner. The superfusion method offers the possibility to investigate the interactions of dissociated A-, B-, and D-cells and the dynamics of hormone release in short- and long-term in vitro experiments. The method is simple and avoids the problems of monolayer procedures, such as clustering of the cells and poor adherence of dissociated pancreatic islet cells to dishes.