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C Phenekos

Publications and source records attributed to C Phenekos.

13 recordsLinked to original sources
PubMed2006

Development and validation of a simple reversed-phase high-performance liquid chromatography method for the determination of testosterone in serum of males.

An isocratic high-performance liquid chromatographic method with detection at 234 nm was developed, optimized and validated for the determination of testosterone in human serum. Propylparaben was used as internal standard. A Hypersil BDS RP-C18 column (150 mmx4.6 mm, 5 microm), was equilibrated with a mobile phase composed of acetonitrile and water (35:65, v/v) and having a flow rate of 1 ml/min. The elution time for testosterone and internal standard was approximately 11.6 and 9.9 min, respectively. Calibration curves of testosterone in serum were linear in the concentration range of 1-20 ng/ml. Limits of detection and quantification in serum were 0.4 and 1.1 ng/ml, respectively. Recovery was greater than 92%. Intra- and inter-day relative standard deviation for testosterone in serum was less than 2.1 and 3.9%, respectively. This method was applied to the determination of testosterone serum levels of 12 healthy males and data were correlated with data obtained using a radioimmunoassay method.

Acetonitriles↗
PubMed2006

Effect of metformin plus roziglitazone compared with metformin alone on glycaemic control in well-controlled Type 2 diabetes.

AIMS: To investigate the effect of metformin plus roziglitazione (RSGMET) compared with metformin alone (MET) on glycaemic control in well-controlled Type 2 diabetes. METHODS: Subjects (drug naïve or those on glucose-lowering monotherapy) were randomized (n = 526), following a 4-week placebo run-in period, to RSGMET [4 mg rosiglitazone (RSG)/500 mg MET] or MET 500 mg. From weeks 2-18, medication was escalated every 4 weeks (based on gastrointestinal tolerability), then remained at RSGMET 8 mg/2 g or MET 3 g for 14 weeks. RESULTS: RSGMET reduced HbA(1c) from 7.2 +/- 0.6 to 6.7 +/- 0.8% at week 32, compared with a reduction from 7.2 +/- 0.6 to 6.8 +/- 0.9% with MET (treatment difference -0.13%; P = 0.0357). More subjects achieved an HbA(1c) value of </= 6.5% at week 32 with RSGMET (51.6 vs. 43.7%), but the treatment difference was not significant (odds ratio 1.37, P = 0.0949). RSGMET produced larger reductions from baseline in mean fasting plasma glucose (adjusted difference -0.62 mmol/l, P < 0.0001), with the odds ratio of achieving a target of < 7.0 mmol/l being 2.33 (P < 0.0001). Statistically significant differences in favour of RSGMET relative to MET were seen for homeostatic model assessment (HOMA)-derived estimates of insulin sensitivity and pancreatic B-cell function, C-reactive protein (CRP), and systolic blood pressure. Overall rates of gastrointestinal adverse events (relevant to the known profile of MET) were comparable, but with a lower incidence of diarrhoea (8 vs. 18%) with RSGMET. Hypoglycaemia was reported in </= 7% subjects per group. CONCLUSIONS: RSGMET provided similar short-term glycaemic control to MET with greater improvements in estimates of insulin sensitivity, B-cell function and CRP, with less diarrhoea and low risk of biochemical hypoglycaemia, suggesting that early use of combination therapy may be appropriate.

Blood Glucose↗
PubMed2005

Strontium ranelate reduces the risk of nonvertebral fractures in postmenopausal women with osteoporosis: Treatment of Peripheral Osteoporosis (TROPOS) study.

BACKGROUND: Strontium ranelate, a new oral drug shown to reduce vertebral fracture risk in postmenopausal women with osteoporosis, was studied in the Treatment of Peripheral Osteoporosis (TROPOS) study to assess its efficacy and safety in preventing nonvertebral fractures also. METHODS: Strontium ranelate (2 g/d) or placebo were randomly allocated to 5091 postmenopausal women with osteoporosis in a double-blind placebo-controlled 5-yr study with a main statistical analysis over 3 yr of treatment. FINDINGS: In the entire sample, relative risk (RR) was reduced by 16% for all nonvertebral fractures (P = 0.04), and by 19% for major fragility fractures (hip, wrist, pelvis and sacrum, ribs and sternum, clavicle, humerus) (P = 0.031) in strontium ranelate-treated patients in comparison with the placebo group. Among women at high risk of hip fracture (age > or = 74 yr and femoral neck bone mineral density T score < or = -3, corresponding to -2.4 according to NHANES reference) (n = 1977), the RR reduction for hip fracture was 36% (P = 0.046). RR of vertebral fractures was reduced by 39% (P < 0.001) in the 3640 patients with spinal x-rays and by 45% in the subgroup without prevalent vertebral fracture. Strontium ranelate increased bone mineral density throughout the study, reaching at 3 yr (P < 0.001): +8.2% (femoral neck) and +9.8% (total hip). Incidence of adverse events (AEs) was similar in both groups. CONCLUSION: This study shows that strontium ranelate significantly reduces the risk of all nonvertebral and in a high-risk subgroup, hip fractures over a 3-yr period, and is well tolerated. It confirms that strontium ranelate reduces vertebral fractures. Strontium ranelate offers a safe and effective means of reducing the risk of fracture associated with osteoporosis.

Aged↗
PubMed2001

Influence of fetal body weight on metabolic complications in adult life: review of the evidence.

Numerous mainly cross-sectional studies have unequivocally shown an inverse relationship between birth weight of infants born at term and the incidence of impaired glucose tolerance, type 2 diabetes mellitus, insulin resistance, hypertension and coronary heart disease. These findings apply to both sexes and are not modified by confounding factors such as age or body mass index. Although the original studies in the UK involved a relatively small number of subjects whose records of birth weight were traced back more than 50 years earlier, similar findings were recorded from larger prospective studies in the USA and Northern Europe. Studies in twins did not support the theory that genetic factors predispose both to low birth weight and morbidity from impaired glucose tolerance, insulin resistance or coronary heart disease, and current evidence points to a resetting of major hormonal axes that control growth and metabolic processes as a possible cause of this association.

Adult↗
PubMed2000

Human galanin secretion is increased upon normal exercise test in middle-age individuals.

Galanin, a neuropeptide, is found in the central nervous system and in a number of nonbrain areas including adrenal sympathetic medullar tissue and pancreas. Several studies involve galanin in the regulation of GH, which responds to stressful stimuli. This study refers to the investigation of the effect of a 20-min exercise on plasma human galanin (hGAL) and GH in middle-aged healthy volunteer adults. Thirteen individuals, 5 males and 8 females aged 40-50 years (44.7 +/- 2.95) were selected on the basis of normal body mass index (22.5 +/- 2.3 kg/m2) and the absence of endocrine or any other abnormality. Basal concentrations of GH and hGAL were measured between 0800 and 0900h after an overnight fast. Post exercise levels were recorded after termination of the stressful test and 15 min thereafter. GH and hGAL were determined by an immunoradiometric and radioimmunoassay, respectively. The exercise-potentiated GH response in all subjects with post-exercise levels significantly higher (11.09 +/- 1.8 ng/ml vs 1.27 +/- 0.7 ng/ml, p<0.0001, F=32.44) with the peak in the hormone level detected 15 min after the end of exercise (12.09 +/- 1.96 ng/ml). Plasma hGAL levels were also substantially affected by the acute exercise test, in that post exercise peripheral blood concentration was significantly higher from the basal values (21.51 +/- 9.94 vs 13.46 +/- 7.2 pg/ml, p<0.02, F=5.50). Again the hGAL values peaked 15 min after the end of exercise (24.0 +/- 10.5 pg/ml, P<0.015, F = 4.68). However, the time-correlation of the increments of GH and hGAL did not reach a statistically significant level (20 min: r=0.41, p=0.161., 35 min: r=-0.095, P=0.758). These results clearly show an independence of the two hormones. The responsivity of hGAL of middle-aged individuals to the exercise stimulus might be due to the higher releasable pool of the hormone.

Adult↗
PubMed1996

Presence of immunoreactive corticotropin-releasing hormone in human endometrium.

Immunoreactive CRH (IrCRH) is produced locally in experimentally induced and spontaneous inflammation. Where it exerts autocrine or paracrine proinflammatory effects. In addition, CRH is secreted by the human placenta, rat Leydig cells, and rat and human ovaries, where it may participate in the inflammatory processes of ovulation and luteolysis, and/or the regulation of steroidogenesis. Finally, CRH is secreted in vitro by cultured human epithelial and decidualized stromal endometrial cells. To investigate the presence of CRH in human endometrium in vivo, we examined this tissue immunohistochemically and by extraction/RIA using a polyclonal, highly specific antirat/human CRH antibody. Endometrial biopsies from 33 women, aged 23-43 yr (median age, 33.5 yr), were performed by linear endometrial curettage for diagnostic purposes at different stages of the cycle. Intense IrCRH staining was localized in the cytoplasm of cells of the endometrial glands in all samples examined. IrCRH was also found in endometrial stromal cells exhibiting decidual reaction and in local immune accessory cells. The mobility of the endometrial IrCRH molecule was similar to that of r/hCRH in reverse phase high pressure liquid chromatography. The presence of CRH in the endometrium, and more specifically in the glandular epithelium during the proliferative and secretory phases of the menstrual cycle together with its known proinflammatory properties, suggest that this neuropeptide might participate in the inflammatory-like phenomena of endometrial physiology, such as menstrual shedding, surface epithelium repair, and/or implantation of the blastocyst. The presence of CRH in decidualized stromal cells is in accordance with its previously reported production by in vitro decidualized cultured endometrial stromal cells as well as by the placental decidua.

Adult↗
PubMed1994

Effect of an acute oral protein load on microalbuminuria in uninephrectomized patients in relation to the time since nephrectomy.

To evaluate the effect of an acute oral protein load (OPL) on urinary albumin excretion (UAE) in uninephrectomized subjects with a negative Albustix test, in relation to the time since nephrectomy, the UAE was determined by a double-antibody 125I radioimmunoassay in 3-hour urine collections before and after 150 g OPL under conditions of moderate physical activity in 18 subjects who underwent unilateral nephrectomy more than 10 years (346.5 +/- 178.60 months) before evaluation and had a mean basal creatinine clearance (CCr) of 45.3 +/- 14 ml/min (group 1), in 21 subjects who underwent unilateral nephrectomy less than 10 years (31.5 +/- 28 months) before evaluation and had a mean basal CCr of 76.0 +/- 22 ml/min (group 2), and in 16 normal volunteers (controls) with a mean basal CCr of 103.1 +/- 12 ml/min. The UAE was higher in group 1 as compared with either group 2 or controls at both basal state (90.8 +/- 65, 19.6 +/- 17, and 11.0 +/- 5 micrograms/min/100 CCr for groups 1 and 2 and controls, respectively; p < 0.001) and after OPL (92.0 +/- 65, 43.6 +/- 24, and 12.0 +/- 5 micrograms/min/100 CCr for groups 1 and 2 and controls, respectively; p < 0.001). However, the increase in UAE following OPL was significant (p < 0.001) only in group 2 patients. In all patients, the basal UAE was negatively correlated with basal CCr (r = 0.63; p < 0.001) and positively correlated with the time since nephrectomy (r = 0.73; p < 0.001) and with both systolic (r = 0.57; p < 0.001) and diastolic blood pressures (r = 0.69; p < 0.001). CCr calculated using 3-hour urine collections increased more in controls (11.2 +/- 44.2%) than in patient groups 1 (1.6 +/- 0.89) and 2 (7.7 +/- 3.7%; p < 0.001). Basal CCr calculated using 24-hour urine collections the day before the test was negatively correlated with the time since nephrectomy in group 1 (r = -0.69; p < 0.001) and positively correlated with the time since nephrectomy in group 2 (r = 0.89; p < 0.001). Multiple regression analysis revealed that the relationship between CCr and duration of uninephric state was independent of age or systolic and diastolic blood pressures in both patient groups. These results suggest that UAE increase significantly after an OPL in subjects who have been nephrectomized less than 10 years before the study and have basal CCr values higher than 50% of normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1994

Presence of immunoreactive corticotropin-releasing hormone in normal and polycystic human ovaries.

Recently, we demonstrated the presence of immunoreactive (Ir) CRH and its receptors in the rat ovary. To determine whether CRH is also present in human ovaries, we examined ovaries from normal women and patients with the polycystic ovarian syndrome (PCOS). Immunoreactive CRH in normal human ovaries had a similar distribution to that of rat ovarian IrCRH, as determined by immunohistochemistry. Thus, immunoreactivity was intense in the cytoplasm of thecal cells surrounding the ovarian follicles, in luteinized cells of the stroma, and in a subpopulation of cells within the corpora lutea. No IrCRH was present in oocytes of primordial follicles. Polycystic ovaries also had IrCRH in thecal cells; however, CRH immunostaining was less prominent or completely absent from the stroma or the sparsely present corpora lutea and was clearly detected in oocytes of primordial follicles. Using a specific RIA, the IrCRH content in extracts of normal ovaries was higher than that in polycystic ovaries (mean +/- SD, 0.075 +/- 0.02 vs. 0.038 +/- 0.009 pmol/g wet tissue, respectively; P < 0.05). Human follicular fluid samples collected from women undergoing ovarian hyperstimulation for assisted reproduction had low, but detectable, levels of IrCRH (mean +/- SD, 4.975 +/- 1.179 pmol/L), whereas IrCRH was undetectable in concurrently drawn plasma samples. IrCRH detected in normal and polycystic ovaries and in follicular fluid had similar chromatographic mobility to that of rat/human CRH-(1-41) by reverse phase HPLC. We conclude that IrCRH is present in normal human ovaries and follicular fluid, suggesting that this neuropeptide may play a regulatory role in one or more of the various functions of this gonad, such as ovulation and/or luteolysis, through its proinflammatory properties and/or its auto/paracrine regulation of steroid biosynthesis, in analogy to its action on testosterone secretion by the Leydig cell. Its decreased concentration and localization in primary oocytes of polycystic ovaries may be related to the increased androgen biosynthesis by the theca and stroma and/or to the oocyte dysfunction observed in women with the polycystic ovarian syndrome, respectively.

Adolescent↗
PubMed1984

Thyroid function in patients with homozygous beta-thalassaemia.

Thyroid function was evaluated in 20 patients aged 8-30 years who were suffering from homozygous beta-thalassaemia. All patients have been receiving frequent blood transfusions and treated for the resulting transfusional iron overload with intramuscular injections of Desferrioxamine. Total thyroxine (T4), T3-uptake, total triiodothyronine (T3), and reverse triiodothyronine (rT3) were measured. In addition a standard TRH stimulation test was performed and blood samples were checked for the presence of thyroid antibodies. It was found that total T4 was significantly lower in the patients than in the controls. Total T3 and rT3 levels were similar in both patients and controls and all patients were negative for thyroid antibodies. T3 uptake in the patients was also statistically different from the controls resulting in significantly lower free thyroxine index (FT1). Basal TSH values were not different from the controls but the TSH increase following TRH stimulation was significantly higher in the patients suggesting, together with the low total T4 and FTI, a state of compensated hypothyroidism.

Adolescent↗