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Comparative Study 2006; 27(1-2): 85-88 PubMed PMID: 16648782 Citation  Keywords:  Adolescent, Adult, Aged, Anticonvulsants:adverse effects, Carbamazepine:adverse effects, Cardiovascular Diseases:blood, Epilepsy:blood, Female, Folic Acid:blood, Humans, Immunoassay, Luminescence, Male, Middle Aged, Phenytoin:adverse effects, Valproic Aci.   

PURPOSE: Previous studies showed an association between the blood levels of folate and vitamin B(12) and the risk for cardiovascular disease. The aim of this study is to investigate the effect of chronic use of phenytoin, carbamazepine or valproate monotherapy on the plasma levels of folate and B(12), and to compare folate and B(12) levels in epileptic patients with or without cardiovasular disorders.

METHODS: The study was conducted in the outpatient neurology clinic at Bahrain Defence Force (BDF) Hospital between January-July, 2005. Medical information was obtained by interviewing the patients and examining their hospital records. Blood folate and vitamin B(12) were measured by Immulite immunoanalysis assay using chemoluminescence.

RESULTS: A total of 26 consecutive outpatients (17 males, 9 females) were recruited in the study. Their mean age +/- SD was 38.2 +/- 20.1 year (range 15-77 year). Five (19.2%) had complex partial epilepsy and the remainder had tonic-clonic seizures. They had epilepsy for 15.7 +/- 8.1 years (range 2-35 years). Thirteen of them used phenytoin, nine carbamazepine and four used valproate. The duration of the treatment (years), dose (mg/day) and serum concentration (micromol/l) were 18.3 +/- 10.6, 376.9 +/- 180.4, 41.6 +/- 25.6, for phenytoin, 14.5 +/- 11.7, 422.2 +/- 175.0, 31.1 +/- 15.9 for carbamazepine and 18.3 +/- 6.3, 400, 567.7 +/- 78.1 for valproate, respectively. Eleven (42.3%) had established cardiovascular disorders such as hypertension, myocardial infarction or stroke. The mean level of plasma folate (12.94 +/- 6.76 ng/ml) and B12 (484.94 +/- 191.25 pg/ml) in epileptic patients with cardiovascular disorders compared to their values (11.27 +/- 5.84), (514.49 +/- 225.31) respectively in epileptics with no cardiovascular disorders were not statistically significant in the two groups.

CONCLUSION: In epileptic patients on chronic therapy with phenytoin, carbamazepine or valproate folate and B(12) levels were not different in patients with or without cardiovascular disorders....

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Journal Article 2005; 26(5): 575-580 PubMed PMID: 16264398 Citation  Keywords:  Acetylserotonin O-Methyltransferase:metabolism, Animals, Arylalkylamine N-Acetyltransferase:metabolism, Female, Melatonin:blood, Microscopy, Electron, Pineal Gland:metabolism, Pregnancy, Pregnancy, Animal:metabolism, Rabbits, Radioimmunoassay,.   

OBJECTIVES: The morphological and biochemical aspects of the pineal gland of pregnant and non-pregnant female vizcachas were investigated to examine whether there is a relationship between the pregnancy and this gland.

METHODS: Pregnant and non-pregnant adult female vizcachas were used. The ultrastructure of type I cell (dark and light pinealocytes) was studied. Pineal and serum melatonin were investigated by radioimmunoassay. Radiometric methods were applied to investigate the arylalkylamine-N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT) activities.

RESULTS: The morphological study showed the existence of dark and light pinealocytes. The differences between both cells are slight. However, the appearance of dark pinealocytes suggests that they have a high activity. These cells were more abundant in the pineal gland of pregnant females. The pineal melatonin levels and the AA-NAT activity were higher in the pregnant females. Serum melatonin and HIOMT activity did not show significant differences.

CONCLUSION: Our results suggest that the morphological and biochemical changes in the pineal gland of pregnant vizcachas are associated with the gestation. However, the relation between the pineal gland and the pregnancy is complex and further studies are necessaries to clearly establish it....

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Comparative Study 2005; 26(5): 459-462 PubMed PMID: 16264390 Citation  Keywords:  Animals, Female, Injections, Intravenous, Injections, Intraventricular, Leptin:administration & dosage, Ovariectomy, Pituitary Hormones:blood, Radioimmunoassay, Rats, Rats, Inbred WKY,.   

OBJECTIVE: It has been reported that leptin plays an important role in the regulation of food intake and energy expenditure. There are controversial opinions about effects of leptin on the hormonal system. The aim of this study was to estimate the effect of leptin on pituitary hormones release after central and peripheral administration.

METHODS: Leptin was injected intracerebroventricularly (icv) in a dose of 0.5 microg/5microl aCSF (artificial cerebrospinal fluid) for 5 min in Wistar Kyoto rats. At 60 and 120 min after injections the animals were decapitated. Leptin in a dose of 10 microg in 300 microl of saline was administered intravenously (i.v). At 60 mins the animals were decapitated. Serum rLH, rFSH, rPRL, rTSH, rGH concentrations were measured with RIA methods.

RESULTS: After central (icv) injection of leptin we observed an increase of rGH, rTSH and a decrease of rPRL. However, after peripheral (iv) injection of leptin we found a decrease of rGH and rTSH and an increase of rPRL. We did not find any significant changes in LH and FSH after icv and iv injection of leptin.

CONCLUSIONS: The opposite effects of leptin on pituitary hormones release were observed due to the method of leptin administration. Leptin may play a modulating role in the mechanism of pituitary hormones release....

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Comparative Study 2005; 26(4): 337-341 PubMed PMID: 16136013 Citation  Keywords:  Adrenocorticotropic Hormone:blood, Adult, Biomarkers:blood, Cystinyl Aminopeptidase:blood, Female, Homeostasis:physiology, Humans, Immunoassay, Pregnancy:blood, Pregnancy Trimester, First, Pregnancy Trimester, Second, Pregnancy Trimester, Third,.   

INTRODUCTION: Normal function of the hypothalamo-adrenal axis is important for the regulation of feto-maternal intrauterine homeostasis including immunomodulating activity and may influence the timing of parturition. ACTH is produced during pregnancy by mother pituitary gland and by trophoblast cells, which are the place of oxytocinase production. Oxytocinase is basically secreted by syncytiotrophoblast cells and rises progressively during pregnancy until the labor. Oxytocinase may play a role as one of the main factors suppressing uterine contractions, controlling the vascular resistance and the volume of the retroplacental blood pool.

MATERIAL AND METHODS: The study group consisted of 102 patients with pregnancy following infertility treatment. The assessment was provided longitudinally in six selected groups progressively according to the gestational age. Immunoassay was used to measure ACTH plasma concentration. Oxytocinase plasma activity was established using l-cystine-di-beta-naphthylamide as a substrate.

RESULTS: Significantly increased oxytocinase plasma level was identified during pregnancy, progressive rise was observed beginning with the first trimester of pregnancy, until the labor. ACTH plasma concentration was observed to be at comparable level in the first and second trimester of pregnancy, while sudden statistically significant increase of ACTH plasma level was noted beginning with 28th week of gestation.

CONCLUSIONS: The assessment of ACTH and oxytocinase plasma concentration might be useful for the evaluation of pregnancy development....

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Journal Article 2005; 26(4): 293-296 PubMed PMID: 16135994 Citation  Keywords:  Adult, Energy Metabolism:physiology, Female, Humans, Insulin:blood, Intracellular Signaling Peptides and Proteins:blood, Leptin:blood, Middle Aged, Neuropeptide Y:blood, Neuropeptides:blood, Obesity:blood, Orexins, Radioimmunoassay,.   

OBJECTIVE: It has been reported that the peptides such as orexins, neuropeptide Y (NPY) and leptin may play an important role in the regulation of appetite and energy metabolism. The interaction between leptin, orexins and NPY, as well as between peptides and insulin and cortisol in the different nutritional states have been investigated in animals. However, at present this relationship is poorly understood in humans.

RESEARCH METHODS: Material consisted of 36 obese women and 16 lean women. Plasma orexin A, orexin B, neuropeptide Y (NPY), leptin, insulin concentrations were measured with RIA methods.

RESULTS: Plasma orexin A concentrations were significantly lower in obese women as compared with control group. Plasma orexin A was significantly lower in severe obesity (BMI > 40 kg/m2) than that in moderate obesity (BMI < 40 kg/m2). Plasma orexin B concentrations did not change. However, plasma NPY, leptin and insulin levels were markedly higher in obese women, especially in severe obesity.

CONCLUSIONS: Our results confirmed the thesis that orexin A, NPY, leptin play an important role in the regulation of energy metabolism in humans. In obesity the activity of these peptides is disturbed....

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Journal Article 2004; 25(6): 415-418 PubMed PMID: 15665802 Citation  Keywords:  Aged, Aged, 80 and over, Aging:metabolism, Analysis of Variance, Cohort Studies, Humans, Melatonin:metabolism, Middle Aged, Radioimmunoassay, Saliva:metabolism,.   

OBJECTIVES: The purpose of this study was to investigate whether melatonin levels in older cohorts within the 'aged' population were significantly lower than in younger 'aged' individuals and hence point to a possible confound in cross-sectional studies which group individuals over 55 in one category.

SETTING AND DESIGN: Melatonin levels of 35 North Queensland residents over 55 years of age living in an aged-care facility, a retirement village or the general community were compared across three age groups.

METHODS: Subjects were ten 56-65 year olds, eighteen 66-75 year olds and seven over-75 year olds. Information was obtained on sleep, awakening, medical conditions and medications, with subsequent exclusion of those with known medical conditions and/or medications. Melatonin was collected by salivary samples at 2200 hours and concentrations were determined by immunoassay.

RESULTS: Mean melatonin levels were significantly lower (p=.03) in the 'oldest' (over 75 yrs) group compared to the 'youngest' (56-65 yrs) group.

MAIN FINDINGS: The results of this preliminary study indicate that within the older population, melatonin levels appear to decline significantly with age.

CONCLUSIONS: Future studies of melatonin and ageing may benefit from a longitudinal approach, with older subjects sampled across time....

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Journal Article 2003; 24(3-4): 227-232 PubMed PMID: 14523362 Citation  Keywords:  Amino Acid Sequence, Animals, Dose-Response Relationship, Drug, Enzyme-Linked Immunosorbent Assay, Hemolymph:metabolism, Leeches:metabolism, Lipopolysaccharides:pharmacology, Molecular Sequence Data, Peptides:metabolism, Radioimmunoassay, Spectrometry, Ma.   

: We demonstrate the presence in leech hemolymph of high levels of a peptide recognized by antiserum directed against bovine chromacin. The purification of the chromacin-like peptide was carried out by an acidic extraction, followed by solid phase and high pressure gel permeation chromatography and reversed-phase HPLC purification. Its sequence (GDFELPSIADPQATFESQRGPSAQQVDK) was established by a combination of techniques, including automated Edman degradation, MALDI-TOF measurement and DOT immunobinding assays with anti-chromogranin A. Mass spectrometry measurement revealed a m/z 3177Da, revealing the fact that the molecule is phosphorylated. ELISA titrations performed at each step of the purification revealed a major increase in the level of the peptide (ca. 125 nmol/microl of coelomic fluid) 15 min after LPS exposure. The increase in chromacin-like peptide levels is both time and concentration dependent. The level of this peptide decreased significantly 4 hours after LPS exposure. This report is the first discovery of a chromogranin derived like peptide in invertebrates....

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Journal Article 2003; 24(3-4): 224-226 PubMed PMID: 14523361 Citation  Keywords:  Animals, Cells, Cultured, Follicle Stimulating Hormone:metabolism, Luteinizing Hormone:metabolism, Male, Nerve Tissue Proteins:pharmacology, Pituitary Gland:cytology, Pituitary Hormones:metabolism, Prolactin:metabolism, Radioimmunoassay, Rats, Rats, Inbre.   

OBJECTIVE: Cocaine- and amphetamine-regulated transcript (CART) is widely expressed in the rat brain, especially in the hypothalamic nuclei and in the anterior pituitary. The aim of this study was to evaluate the effects of CART on pituitary hormone release in pituitary cell culture.

MATERIAL AND METHODS: The pituitary hormone release from pituitary cell culture after CART administration was investigated. Concentrations of LH, FSH, PRL, TSH and GH were measured with RIA methods.

RESULTS: CART in all doses (1 nMol, 10 nMol, 100 nMol) stimulated prolactin (PRL) release and inhibited TSH release. CART administration caused a dose dependent decrease in LH release. CART did not change GH release from cultured pituitary cells.

CONCLUSION: CART may affect directly pituitary hormones release in the cell culture....

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