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Editorial 2003; 24(6): 386-388 PubMed PMID: 15077063 Citation  Keywords:  Allergy and Immunology, Neuroendocrinology, Peer Review, Research:trends, Periodicals as Topic:trends,.   

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Journal Article 2003; 24(6): 469-473 PubMed PMID: 15073579 Citation  Keywords:  2',3'-Cyclic-Nucleotide Phosphodiesterases:metabolism, Animals, Antineoplastic Agents:pharmacology, Astrocytes:cytology, Cell Division:drug effects, Cell Line, Tumor, Curcumin:pharmacology, Glioma, Glutamate-Ammonia Ligase:metabolism, Oligodendroglia:cyto.   

OBJECTIVES: Curcumin (CUR), the active chemical of the Asian spice turmeric, has strong anti-oxidant and anti-inflammatory properties. CUR inhibits proliferation and growth of several cell types, e.g. cancer cells. While CUR inhibitory effects on microglial cells are demonstrated, little is known of its effects on neuroglia, astrocytes (AST) and oligodendrocytes (OLG). Our work focuses on CUR's effects on neuroglial proliferation and growth in vitro, utilizing C-6 rat glioma 2B-clone cells, a mixed colony of both neuroglial cells, in 6 day trials.

METHODS: The doses studied included 4, 5, 10, 15, and 20 microM - concentrations slightly smaller than those shown to stimulate protein expression in ASTs. Automated particle counter was used to determine proliferation, and marker enzyme assays were used to determine AST and OLG activity.

RESULTS: CUR inhibited neuroglial proliferation, with the degree of inhibition correlated directly with the CUR concentration. Proliferative inhibition was observed after a concentration as low as 5 microM by day 6, while inhibition of 20 microM doses occurred by day 2 of culture. Proliferative inhibition is associated with morphological changes, e.g. cell elongation and neurite prolongation, and increased activity of a marker enzyme corresponding to differentiation of OLG and with a reduced activity of the marker enzyme for AST.

CONCLUSIONS: Our data suggests CUR acts continuously over a period of time, with low doses being as effective as higher doses given a longer period of treatment. It has been suggested that CUR's anti-inflammatory and anti-oxidant actions may be useful in the prevention-treatment of neurodegenerative diseases, e.g. Alzheimer's and Parkinson's Diseases. Given neuroglial involvement in these diseases, and CUR's observed actions on neuroglia, the data presented here may provide further explanations of CUR's preventative-therapeutic role in these diseases....

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Letter 2003; 24(6): 469-473 PubMed PMID: 15073578 Citation  Keywords:  Adrenergic beta-Antagonists:therapeutic use, Autonomic Nervous System Diseases:drug therapy, Humans, Immunity, Cellular:drug effects, Immunocompromised Host:drug effects, Stress Disorders, Traumatic:complications,.   

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Clinical Trial 2003; 24(6): 463-467 PubMed PMID: 15073577 Citation  Keywords:  Adult, Continuous Positive Airway Pressure, Humans, Luteinizing Hormone:blood, Male, Middle Aged, Pituitary Gland:physiology, Sleep Apnea, Obstructive:physiopathology, Testis:physiology, Testosterone:blood, Treatment Outcome,.   

OBJECTIVES: Decreased libido and a decline in morning serum testosterone levels were reported in men with obstructive sleep apnea (OSA). Our study aimed to evaluate the pituitary-gonadal axis in middle age men with OSA before and after treatment with nasal continuous positive airway pressure (CPAP).

MATERIAL AND METHODS: Measurement of the nocturnal serum luteinizing hormone (LH) and testosterone levels and sleep recordings before and after nine months of CPAP treatment in five men with OSA aged 49.5+/-5.2 years. Patients were evaluated during nocturnal sleep at base line and during CPAP treatment. Serum LH and testosterone levels were determined at 20 minutes interval between 1900h and 0700h with concomitant determination of sleep quality, respiration and oxygen saturation.

RESULTS: At base line, patients had higher RDI and PaO2<90%, lower mean and integrated (AUC) values of LH and testosterone. During CPAP treatment, RDI and PaO2<90% were normal. Mean and AUC values of testosterone and LH increased.

CONCLUSIONS: OSA in men is associated with dysfunction of the pituitary-gonadal axis. The central suppression of nocturnal testosterone in these patients is partially corrected during chronic CPAP treatment....

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Journal Article 2003; 24(6): 449-453 PubMed PMID: 15073574 Citation  Keywords:  Adolescent, Adult, Educational Measurement, Exploratory Behavior, Female, Humans, Hydrocortisone:metabolism, Male, Psychometrics, Saliva:metabolism, Stress, Psychological:diagnosis, Students:psychology,.   

OBJECTIVES: Although it is widely accepted that academic examinations are accompanied by a cortisol increase, some recent studies reported either no effect or even a decline of the cortisol level. To reevaluate these discrepancies, we investigated whether personality traits predict the cortisol response upon academic examinations.

SETTING AND DESIGN: Nineteen male and female adolescent pupils (17 to 19 years) participated in the study. Two anticipated, mandatory, routine written examinations were used as familiar stressful conditions, whereas an anticipated, mandatory oral examination in front of a board of known and unknown examiners was used as a novel stressful situation.

METHODS: Baseline, pre- and postexamination salivary cortisol were quantified and correlated with psychometric measures, including self-estimated stress level, obtained from a five-point scale, and sensation seeking subscales according to Zuckerman.

RESULTS: Salivary cortisol response, taken as an average of all subjects, showed a transient increase upon examinations. However, comparing individual cortisol responses revealed three distinct cortisol profiles, including a transient increase (Type 1), a transient decline (Type 2), or no response (Type 3). Type 1 predominates in examinations combined with novelty. A moderate negative association was noted between saliva cortisol concentrations on some sensation seeking subscales. Self-reported stress levels did not significantly correlate with salivary cortisol concentration.

CONCLUSION: Our findings show that upon academic examinations the cortisol response varies among subjects. A moderate negative association was unveiled by correlating individual cortisol responses with sensation seeking subscales....

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Journal Article 2003; 24(6): 445-448 PubMed PMID: 15073573 Citation  Keywords:  Adult, Female, Homocysteine:blood, Humans, Lipid Peroxidation, Lipid Peroxides:metabolism, Malondialdehyde:blood, Pre-Eclampsia:blood, Pregnancy, Severity of Illness Index,.   

OBJECTIVE: To investigate the possible correlation between plasma malondialdehyde and homocysteine levels of preeclamptic patients.

DESIGN: Venous blood samples of 20 preeclamptics and 20 healthy pregnant controls were collected. Plasma malondialdehyde and homocysteine concentrations were measured and the correlation between them was investigated. Mann Whitney U test and Spearman correlation analysis were used for statistical analysis.

SETTING: University of Firat, Medical School.

RESULTS: Plasma malondialdehyde and homocysteine concentrations were higher in preeclamptic patients (p<0.05) and a positive correlation between these parameters was found (r: 0.77, p<0.01, n:20).

CONCLUSION: Our results may put forward some new strategies in the research of etiopathogenesis and treatment of preeclampsia....

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Journal Article 2003; 24(6): 440-444 PubMed PMID: 15073572 Citation  Keywords:  Adjuvants, Immunologic:pharmacology, Breast Neoplasms, Cell Division:drug effects, Cell Line, Tumor:cytology, Drug Interactions, Estradiol:pharmacology, Estrogen Receptor alpha, Estrogen Receptor beta, Female, Gene Expression Regulation, Neoplastic:drug e.   

OBJECTIVES: Detection of the antiestrogenic effect of melatonin on various breast cancer cell lines and its dependence of the differential expression of estrogen receptors (ERalpha and ERbeta) and melatonin receptors (mt1 and RZRalpha).

SETTING AND DESIGN: Dose-response curves of estradiol were determined in 6 different breast cancer cell lines using a colorimetric proliferation assay in the absence or presence of various melatonin concentrations.

METHODS: In order to detect the minor growth inhibitory effect of melatonin, a simple yet novel approach was employed: instead of incubating cells at single estradiol-concentrations at increasing melatonin levels, breast cancer cells were grown in microwell-plates for 4 days at increasing concentrations of estradiol (10(-12)M - 10(-10)M) in the absence or presence of melatonin (10(-9)M - 10(-8)M). Cell number was determined using Alamar blue and colorimetry. RT-PCR was performed for the expression of ERalpha, ERbeta, RZRalpha and mt1.

RESULTS: Melatonin at concentrations of 10(-9)M and 5 x 10(-9)M shifted the dose-response curves of estradiol to higher concentrations. Responsiveness to melatonin depended on expression of ERalpha but not on ERbeta. mRNA of ERbeta was not detectable in the breast cancer cell lines used. Only small amounts of mt1 transcripts were detectable in MCF-7 cells of one source. In MCF-7 cells transfected with the mt1 gene and in an ovarian cancer cell line mt1 was expressed at significant levels. RZRalpha was expressed in all tested cell lines at different amounts.

CONCLUSION: The growth of all ERalpha-positive breast cancer cell lines can be inhibited by melatonin. The effect in most cell lines is weak yet clearly reproducible. RZRalpha clearly contributes to the growth inhibitory effect of melatonin....

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Journal Article 2003; 24(6): 435-439 PubMed PMID: 15073571 Citation  Keywords:  2-Amino-5-phosphonovalerate:pharmacology, Age Factors, Animals, Dizocilpine Maleate:pharmacology, Excitatory Amino Acid Antagonists:pharmacology, Hypothalamus:drug effects, Injections, Intraventricular, Male, Prolactin:metabolism, Rats, Rats, Wistar, Rece.   

OBJECTIVE: To investigate the effects of N-methyl-D-aspartate (NMDA) receptor antagonists on restraint-induced release of prolactin (PRL) in male Wistar rats of different ages.

DESIGN: Rats were implanted with a brain ventricular for icv injection, and with a jugular vein cannula for iv injection. Competitive NMDA receptor antagonist AP-5 and noncompetitive NMDA receptor blocker MK-801 was injected via brain cannula or vein cannula and was restrained for 3 hours. The blood sample was collected through vein cannula during the restraint. The plasma concentration of prolactin was measured by RIA.

RESULTS: The restraint-induced PRL release in the adult rat (12-weeks) was significantly suppressed by MK-801 (50 microg/rat, icv; or 5 mg/kg, iv) and was partially inhibited by pretreatment of AP-5 (50, 100 microg/rat, icv), but was not changed by systemic administration of AP-5 (10 mg/kg, iv). MK-801 (5 mg/kg, iv) prevented the restraint-induced PRL release in the peripuberal rat (45-days) and in the middle-aged rat (16-months).

CONCLUSION: Central NMDA receptors mediate restraint-induced PRL release in the male rat....

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