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Namazi M. The cellular immunodeficiency associated with post-traumatic stress disorder may be the result of sympathetic overactivity and be correctable by beta-2-blockers. Neuro Endocrinol Lett. 2003 Dec; 24(6): 469-473
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....
Luboshitzky R, Lavie L, Shen-Orr Z, Lavie P. Pituitary-gonadal function in men with obstructive sleep apnea. The effect of continuous positive airways pressure treatment. Neuro Endocrinol Lett. 2003 Dec; 24(6): 463-467
OBJECTIVES: Approximately 20% of BALB/cCF mice are born with partial or total absence of the corpus callosum. Here, we analyzed testosterone and free thyroxin blood levels in adult male mice of this strain in order to see if these hormones are related to the incidence of callosal defects.
METHODS: Blood collected from the axillary blood vessels of 12 normal and 10 acallosal deeply anesthetized adult male mice was used in order to determine testosterone and free thyroxin levels through chemiluminescence (IMMULITE, Diagnostics Products Corporation, USA).
RESULTS: No significant difference (one-way ANOVA: F = 0.11, df = 1, p > 0.10) was found between normal ((-)X= 1.95, SD = 0.62) and acallosal ((-)X= 1.86, SD = 0.62) mice for free thyroxin level. On the other hand, in those mice that had detectable testosterone levels (above 0.2 ng/ml), a significant difference was found (t = 2.8, df = 6.06, p = 0.03): normal mice (n = 7, (-)X= 8.73, SD = 7.64) had a higher level than acallosal mice (n = 4, (-)X= 0.62, SD = 0.41).
CONCLUSIONS: The present results indicate that the incidence of callosal agenesis is not related to free thyroxin levels in the blood of adult BALB/cCF mice. On the other hand, in spite of the fact that low testosterone levels seems to be frequent in male mice of this strain, acallosal mice tend to have lower levels of this hormone than normal mice....
Mourão C, Schmidt S, Manhães A. Testosterone and free thyroxin blood in congenitally acallosal male BALB/cCF mice. Neuro Endocrinol Lett. 2003 Dec; 24(6): 459-462
PURPOSE: To evaluate the function of the blood aqueous barrier(BAB) in the eyes with silicone oil emulsification (SOE).
METHODS: Protein concentrations, expressed in albumin equivalents,were determined in aqueous humor of the eyes with SOE in 11 consecutive patients by means of proton nuclear magnetic resonance (1H NMR) spectroscopy. Correlations with various clinical factors were studied.
RESULTS: Normal function of the BAB (albumin equivalents 1mg/ml and less was found in 8 eyes (73%) independently on underlying disease, early postoperative reaction after pars plana vitrectomy with SO implantation, degree of SOE and late postoperative complications. Increased permeability of the BAB (albumin equivalents equal 2, 3 and 6.5 mg/ml) was found in 3 eyes (27%) with recent acute complication (retinal detachment after SO removal in 2 eyes, and secondary angle closure glaucoma in 1 eye).
CONCLUSION: SOE in vivo was associated with increased permeability of the BAB in the minority of the eyes. Other factors should be studied to explain the variability of SOE. 1H NMR spectroscopy might be a valuable method for the study of SOE....
Soucek P, Havlícek J, Tkadlecová M, Karel I, Volka K, Cihelková I. The function of the blood aqueous barrier in eyes with emulsified silicone oil. Neuro Endocrinol Lett. 2003 Dec; 24(6): 454-458
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....
Martinek L, Oberascher-Holzinger K, Weishuhn S, Klimesch W, Kerschbaum H. Anticipated academic examinations induce distinct cortisol responses in adolescent pupils. Neuro Endocrinol Lett. 2003 Dec; 24(6): 449-453
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....
Tug N, Celik H, Cikim G, Ozcelik O, Ayar A. The correlation between plasma homocysteine and malondialdehyde levels in preeclampsia. Neuro Endocrinol Lett. 2003 Dec; 24(6): 445-448
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....
Girgert R, Bartsch C, Hill S, Kreienberg R, Hanf V. Tracking the elusive antiestrogenic effect of melatonin: a new methodological approach. Neuro Endocrinol Lett. 2003 Dec; 24(6): 440-444
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....
Liu J, Du J, Asai S, Shi Z, Watanabe G, Taya K. NMDA receptor antagonists reduce restraint-induced release of prolactin in male rats. Neuro Endocrinol Lett. 2003 Dec; 24(6): 435-439