beta-Sitosterol activates the sphingomyelin cycle and induces apoptosis in LNCaP human prostate cancer cells.

Epidemiological evidence has shown that men consuming a low-fat, high-fiber diet containing high amounts of plant products have a lower risk of prostate cancer than men consuming a Western diet. One of the main differences between these two diets is the type of dietary fat, including dietary sterols. This study was undertaken to compare the effect of two dietary sterols on prostate cancer cells in vitro.

Kinetics and energetics of specific intermolecular interactions.

Taking into account the energy vs. distance functions of the aspecific (macroscopic) repulsion that usually prevails between antigen (Ag) and antibody (Ab) molecules in polar media, as well as the specific (microscopic) attraction between epitope and paratope of Ag and Ab, it proved possible to determine the kinetic constants (von Smoluchowski, 1917; Hammes, 1978) of Ag-Ab interactions, from the surface properties of Ag, Ab and the aqueous medium. The kinetic constants thus found correlate well with experimentally determined kinetic constants in comparable systems, and confirm the importance of the influence of the concentration of one of the reagents (e.

Oxidative stress and lung function.

It has been suggested that lung function can be altered by both free radical and oxidant exposure, while antioxidant vitamin intake is positively related to lung function. However, the information on the relation of blood levels of oxidants and antioxidants to lung function is sparse. The present cross-sectional study, conducted from September 1995 to May 1996, analyzes the association between lung function measured as forced expiratory volume in 1 second (FEV1) with 1) levels of thiobarbituric acid-reactive substances in plasma (p-TBARS) and in low and very low density lipoprotein cholesterol (LDL cholesterol/VLDL cholesterol-TBARS) as indicators of lipid peroxidation and 2) compounds with antioxidant activity, erythrocytic glutathione, plasma glutathione peroxidase, trolox equivalent antioxidant capacity, and serum bilirubin, which may protect against lipid peroxidation.

Body mass index and mortality in a general population sample of men and women. The Buffalo Health Study.

The objective of this research was to investigate the long-term relation between body mass index (BMI) and mortality from all causes and from specific causes in the general population. A 29-year follow-up study was conducted in a random sample of white men (n = 611) and women (n = 697) aged 20-96 years who were residents of Buffalo, New York, in 1960. At baseline, height and weight were determined by self-report.

Effects of ibogaine on performance in the 8-arm radial maze.

The effects of ibogaine were studied in 12 rats trained to perform in an 8-arm radial maze. In Phase I, the mean number of sessions to criterion and cumulative errors to criterion, as well as mean response rate, were determined for two groups of six animals in a task where only four arms were baited. Group 1 received a potentially neurotoxic dose of ibogaine (50 mg/kg IP administered twice, with approximately 8 h between injections), and group 2 received vehicle.

The effects of age on continuous learning in the radial maze.

Two groups of male Fischer 344 rats were trained in 1 session per day on a series of tasks in a food-reinforced radial maze. The younger group (n = 10) was 3 months old at the start of these experiments; the older group (n = 10) was 21 months old at the start. Following acclimation to the maze, subjects were trained successively on an 8-arm task (8A1) in which entry into all arms was reinforced and a 4-arm task (141) in which only entry into arms 1 through 4 was reinforced.

Morphometric evidence that the total number of synapses on Purkinje neurons of old F344 rats is reduced after long-term ethanol treatment and restored to control levels after recovery.

Clinical symptoms of alcohol abuse may be confused with symptoms of age-related neuropathologies in human patients. It is important, therefore, to determine the relationships between alcohol abuse and changes in brain structures in well-controlled studies of ageing subjects. Currently there is little well-documented information of this type available.

The effects of noribogaine and harmaline in rats trained with ibogaine as a discriminative stimulus.

In the present investigation, Fischer-344 rats were trained to discriminate 10.0 mg/kg of ibogaine from water using a pretreatment time of 60 minutes. Analysis of dose response data generated an ED50 of 4.

Ibogaine and noribogaine potentiate the inhibition of adenylyl cyclase activity by opioid and 5-HT receptors.

The effects of the putative anti-addictive compound ibogaine and its principal metabolite, noribogaine, on adenylyl cyclase activity were determined in various areas of the rat brain. Neither compound altered either basal or forskolin-stimulated adenylyl cyclase activities in the frontal cortex, midbrain or striatum. However, in all three brain areas the addition of ibogaine and noribogaine significantly enhanced inhibition of adenylyl cyclase activity by a maximally effective concentration of morphine.

The alpha-hemolysin of Streptococcus gordonii is hydrogen peroxide.

The alpha-hemolysin of viridans group streptococci, which causes greening of intact erythrocytes, is a potential virulence factor as well as an important criterion for the laboratory identification of these bacteria; however, it has never been purified and characterized. The alpha-hemolysin of Streptococcus gordonii CH1 caused characteristic shifts in the A403, A430, A578, and A630 of sheep hemoglobin. A spectrophotometric assay was developed and used to monitor purification of alpha-hemolysin during extraction in organic solvents and separation by reverse-phase high-performance liquid chromatography (HPLC).

Effects of ibogaine and noribogaine on phosphoinositide hydrolysis.

The effects of the antiaddictive compound, ibogaine, and its primary metabolite, noribogaine (12-hydroxyibogamine), on phosphoinositide hydrolysis were investigated. Although ibogaine did not alter phosphoinositide turnover in either striatal or hippocampal slices, noribogaine elicited a concentration-dependent increase in the generation of [3H]inositol phosphates. This stimulation was not altered by inclusion of tetrodotoxin, cadmium or omega-conotoxin indicating that the increased production of [3H]inositol phosphates was not secondary to a release of one or more neurotransmitters.

The accuracy of computed tomography-based linear measurements of human femora and titanium stem.

Rationale And Objectives: The authors investigate the accuracy of computed tomography linear measurement of femora with titanium stem, and the effect of the stem on these measurements.

Materials And Methods: Two embedded cadaveric femora, one of them containing a titanium stem, and two cortical bone parallelepipeds were scanned. Thirty-six cross-sections were studied, each measured in two linear directions by the profile window technique.

Mismeasurement and the resonance of strong confounders: uncorrelated errors.

Greenland first documented (Am J Epidemiol 1980; 112:564-9) that error in the measurement of a confounder could resonate--that it could bias estimates of other study variables, and that the bias could persist even with statistical adjustment for the confounder as measured. An important question is raised by this finding: can such bias be more than trivial within the bounds of realistic data configurations? The authors examine several situations involving dichotomous and continuous data in which a confounder and a null variable are measured with error, and they assess the extent of resultant bias in estimates of the effect of the null variable. They show that, with continuous variables, measurement error amounting to 40% of observed variance in the confounder could cause the observed impact of the null study variable to appear to alter risk by as much as 30%.

Potentiation of LSD-induced stimulus control by fluoxetine in the rat.

The present investigation examined the interaction between fluoxetine enantiomers and LSD in rats trained with LSD as a discriminative stimulus. The dose response relationships for LSD alone and in combination with either (+)- or (-)-fluoxetine were determined. In both instances, the LSD dose response relationship was shifted to the left.

Nutrition and oral cancer.

Epidemiologic evidence on the relationship between nutrition and oral cancer is reviewed. Ecologic and case-control studies provide most of the evidence regarding the nutritional epidemiology of oral cancer. The ecologic evidence is that the considerable geographic variation in the incidence of oral cancer is consistent with variation in nutrition.

The interaction of clozapine with the meta-chlorophenylpiperazine (mCPP) discriminative stimulus.

The psychotropic effects of the 5-HT2C agonist mCPP in human subjects are blocked by the atypical antipsychotic clozapine, but not by typical antipsychotics. An understanding of the mechanistic basis for the interaction of clozapine and mCPP would provide further insight into the basis for its unique therapeutic effects in humans. Drug-induced stimulus control provides an animal model for the subjective effects of psychotropic agents in humans.

Isolation and functional characterization of the human gene encoding the myeloid zinc finger protein MZF-1.

The expression of the human myeloid zinc finger gene (MZF-1) by human bone marrow cells is necessary for granulopoiesis. We have analyzed the structure and function of the MZF-1 gene by diagnostic polymerase chain reaction, genomic cloning, and promoter analysis. Comparison of human promyelocytic HL-60 cell cDNA with isolated MZF-1 genomic clones indicated that the human MZF-1 gene is without introns and spans approximately 3 kb.

Measurements of dendritic path lengths provide evidence that ethanol-induced lengthening of terminal dendritic segments may result from dendritic regression.

The present study proposed to determine the significance of previously reported ethanol-induced dendritic lengthening in mature cerebellar Purkinje neurons (PN). An analysis of dendritic path lengths (PL) was used to make this determination. A PL is the curvilinear length from the origin of the dendritic root segment to the free tip of a dendritic terminal.

Interactions of clozapine with the stimulus effects of DOM and LSD.

Two groups of rats were trained with the 5-HT2 agonists 2,5-dimethoxy-4-methylamphetamine (DOM) or lysergic acid diethylamide (LSD) in a two-lever discrimination task. Tests of generalization and antagonism were then carried out with clozapine. DOM did not generalize to clozapine.

Characterization of the purinergic P2 receptors in PC12 cells. Evidence for a novel subtype.

The properties of the purinergic receptors in the PC12 cells were studied. The rank order of potency to increase [Ca2+]i was: adenosine 5'-O-(1-thiotriphosphate) > ATP > adenosine 5'-O-(3-thiotriphosphate) >>> 3'-O-(4-benzoyl-benzoyl)ATP. ADP, AMP, GTP, UTP, alpha, beta- and beta,gamma-methylene adenosine 5'-triphosphates, 5'-adenylylimido-diphosphate, and adenosine analogues were ineffective.

Chronic ethanol exposure potentiates muscarinic receptor and alpha 2-adrenoceptor-mediated inhibition of cAMP accumulation in PC 12 cells.

The effects of ethanol on receptor-mediated inhibition of cAMP production were investigated in PC 12 cells. The in vitro addition of ethanol enhanced N-ethylcarboxyadenosine (NECA)-stimulated cAMP production without altering the inhibitory action of carbachol or epinephrine. A 4 day exposure of PC 12 cells to ethanol decreased the stimulation of cAMP production by NECA, but increased the inhibition of NECA-stimulated cAMP production by carbachol and epinephrine.