Search NEL Online

Clinical Trial 2004; 25(1-2): 75-77 PubMed PMID: 15159687 Citation  Keywords:  Adaptation, Physiological, Adolescent, Adult, Altitude, Atmospheric Pressure, Fasting:blood, Humans, Jordan, Luteinizing Hormone:blood, Male, Reference Values, Religion, Testosterone:blood,.   

OBJECTIVES: To study a possible effect of Ramadan fasting on luteinizing hormone and testosterone in people of the Jordan Valley.

METHODS: A comparative study (n=40) of serum levels of luteinizing hormone (LH) and testosterone (T) between people living in the Jordan Valley (JV), n=20, 360 meters below sea level, and those living in Ramtha City (RC), n=20, 600 meters above sea level, was conducted in December, 1998. A similar study (n=40) was also done during January 1999 in fasting people during the month of Ramadan.

RESULTS: Serum levels of LH in non-fasting people of the JV were statistically similar to those in people of RC. There was also no difference in serum levels of T between non-fasting people of the JV and those in RC. Serum levels of LH in fasting people of the JV were statistically indifferent from those fasting in RC. Serum T levels in fasting people of the JV, on the other hand, were higher than those in fasting people of RC (76+/-18.3 ng/ml compared to 62.7+/-24.2 ng/ml).

CONCLUSIONS: It is probably the environmental factors such as the higher barometric pressure of the JV compared to that at above sea level that play a role in higher serum levels of T in people of the JV. Other factors, such as genetic background and/or the cultural and nutritional characteristics of the people of the JV, may also contribute to this difference in serum T levels....

Read abstract  Full text PDF

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,.   

...

Read abstract  Full text PDF

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....

Read abstract  Full text PDF

Journal Article 2003; 24(6): 459-462 PubMed PMID: 15073576 Citation  Keywords:  Agenesis of Corpus Callosum, Animals, Brain Diseases:blood, Corpus Callosum:pathology, Incidence, Male, Mice, Mice, Inbred BALB C, Mice, Mutant Strains, Testosterone:blood, Thyroxine:blood,.   

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....

Read abstract  Full text PDF

Journal Article 2003; 24(6): 392-396 PubMed PMID: 15073562 Citation  Keywords:  Animals, Circadian Rhythm, Male, Melatonin:blood, Models, Animal, Pineal Gland:secretion, Postoperative Complications:metabolism, Pressure, Rats, Rats, Sprague-Dawley, Surgical Instruments,.   

OBJECTIVES: Pineal gland hormone, melatonin, is a current issue of interest for accumulating data concerning its diverse physiological functions. The disturbances in melatonin secretion are observed in different pathological conditions involving pineal regions, but it is not ascertained if those disturbances present any clinical implications. The aim of this work was to examine whether pineal gland compression changes melatonin secretion.

SETTING AND DESIGN: The experiment was carried out on adult rats, divided into four equal groups: (i) control (no surgery was performed), (ii) sham-operated, (iii) with sham pineal gland compression and (iv) with pineal gland compression performed by cotton piece application.

METHODS: The profile of melatonin secretion was assessed in blood samples collected five times daily, every second day, starting from 8 to 14 day following surgery.

RESULTS: We found that surgery itself significantly increased night melatonin secretion in comparison to controls. By contrast, in pineal-gland compressed rats, melatonin secretion was lower than in control group, suggesting that the influence of pineal compression overcame that induced by operation stress.

CONCLUSIONS: In conclusion, we presume that pineal gland compression (like in case of some tumors) results in decrease of the concentration of blood melatonin, that may possibly result in decreased protective action of the indoleamine....

Read abstract  Full text PDF

Journal Article 2003; 24(5): 345-347 PubMed PMID: 14647010 Citation  Keywords:  Animals, Antioxidants:pharmacology, Hyperthyroidism:drug therapy, Injections, Intraperitoneal, Male, Melatonin:pharmacology, Rats, Rats, Sprague-Dawley, Testis:drug effects, Testosterone:metabolism, Thyroid Gland:drug effects, Thyroid Hormones:metabolism,.   

OBJECTIVE: Melatonin has a general inhibitory effect on the reproductive system and thyroid functions. Testosterone secretion increases in parallel to thyroid hormones in hyperthyroidism. The aim of this study was to investigate the effects of melatonin application on total T3, T4 and testosterone in hyperthyroid rats.

METHODS: This study was performed on 4 groups each consisted of 6 male Spraque Dawley rats. Control group (G1); sham group (G2); applied 0.5 ml/day of serum physiologic intraperitoneally for 2 weeks, hyperthyroid group (G3); applied 0.3 mg/kg/day thyroxine intraperitoneally for 2 weeks, and hyperthyroid and melatonin supplemented group (G4); applied 0.3 mg/kg/day thyroxine and 3 mg/kg/day melatonin. Blood samples taken by way of decapitation were analysed for total T3, T4 and testosterone by RIA.

RESULTS: Serum total T3 and total testosterone levels were the highest in hyperthyroid group (G3), whereas in hyperthyroid and melatonin supplemented group (G4) were the lowest (P<0.001). Total T4 levels were higher in group 3 than group 1, 2 and 4 (P<0.001).

CONCLUSION: Results revealed that melatonin supplementation in hyperthyroidism suppress secretion of thyroid hormones and testosterone secretion....

Read abstract

Clinical Trial 2003; 24(5): 334-338 PubMed PMID: 14647007 Citation  Keywords:  Adenoma:drug therapy, Adult, Antineoplastic Agents:administration & dosage, Apoptosis:drug effects, Female, Humans, Male, Middle Aged, Peptides, Cyclic:administration & dosage, Pituitary Neoplasms:drug therapy, Somatostatin:administration & dosage,.   

OBJECTIVES: Apoptosis of endocrine cells represents one of factors significantly affected the control of hormones secretion. Present study aimed to examine whether treatment of somatotropinoma types tumours with somatostatine analogue (lanreotide) results in apoptosis.

MATERIAL AND METHODS: The studies were performed on 35 patients with somatotropinoma type tumours on whom adenomectomy was performed by transsphenoidal approach. The operative material was examined by cellular morphology, based on light and electron microscopy and chromosomal ladder formation assay.

RESULTS: The number of apoptotic cells showed features typical for the process as condensation and fragmentation of chromatin, vacuolisation, damage of the inner structure of mitochondria and oligonucleosomal fragmentation of DNA was found in the study material. The results of the studies demonstrated the occurrence of lanreotide induced apoptosis in somatotropinoma type tumours. The grade of apoptotic cells in macroadenomas type adenomas, treated with lanreotide, ranged from 4.0% to 17.1% (mean 8.7+/-2.6%). Patients in whom hypophysectomy was not preceded by lanreotide treatment demonstrated low level of apoptotic cells (no more than 3.5%).

CONCLUSIONS: The studies showed that treatment with somatostatine analogue-lanreotide induced apoptosis of tumour cell suggesting that the induction of apoptotic cell death may be involved in the anticancer activity of somatostatine analogue....

Read abstract

Journal Article 2003; 24(5): 325-328 PubMed PMID: 14647005 Citation  Keywords:  Aldosterone:urine, Blood Pressure:genetics, Genetic Markers, Humans, Hypertension, Renal:genetics, Insulin:genetics, Middle Aged, Minisatellite Repeats, Phenotype, Pilot Projects, Polymorphism, Restriction Fragment Length, Potassium:urine, Quantitative Tr.   

BACKGROUND: Blood pressure regulation is a complex process influenced by numerous environmental and genetic factors. Consequently, there's no cookie-cutter approach for the elucidation of of the genetic mechanism involved. One of the goals of molecular geneticists in the field of hypertension is to unravel the genetic architecture of blood pressure regulation.

METHODS: With the aim of identifying quantitative trait loci participating in the control of blood pressure, we carried out a pilot study on a sample population of middle-aged, U.S. Caucasians (44 subjects). The design of the study was to search for associations between clinical variables of blood pressure regulation pertaining to the renin-angiotensin-aldosterone system (systolic and diastolic blood pressures, urinary excretion of sodium, potassium and aldosterone, plasma renin activity) and a genetic marker at a candidate gene locus - the human insulin gene (INS) RESULTS: We observed significant associations between a variable number of tandem repeats (VNTR) marker (visualized as a biallelic, class I/class III marker system) localized at the 5' end of the human INS gene, and plasma renin activity and urinary sodium, potassium and aldosterone.

CONCLUSION: Our results indicate that between 6 and 10 QTLs with comparable effects could be involved in blood pressure regulation via the rennin angiotensin system....

Read abstract