Effect of an acute injection of melatonin on the basal secretion of hypophyseal hormones in prepubertal and pubertal healthy subjects

1986 ◽  
Vol 111 (3) ◽  
pp. 305-311 ◽  
Author(s):  
P. Lisoni ◽  
M. Resentini ◽  
R. Mauri ◽  
C. De Medici ◽  
F. Morabito ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Healthy Subjects ◽  
Pubertal Development ◽  
Venous Blood ◽  
Pituitary Hormones ◽  
Significant Rise ◽  
Saline Infusion ◽  
Blood Samples ◽  
The Mean ◽  
Acute Injection

Abstract. It is well known that the pineal gland can modulate the secretion of pituitary hormones. Melatonin, the main hormone produced by the pineal gland, acts at the hypothalamic site, whereas hypophyseal sensitivity to melatonin seems to change with age. To investigate the influence of pubertal development on the role of the pineal gland in the regulation of the secretion of pituitary hormones, FSH, LH, Prl, TSH and GH responses to melatonin were evaluated in a group of 9 prepubertal and 10 pubertal healthy subjects of both sexes. Melatonin was given im at a dose of 0.2 mg/kg body weight at 3 p.m. Venous blood samples were drawn −20, 0, 20, 40, 60, 90, 120, 180 and 240 min, after melatonin injection. According to the same experimental protocol, venous blood samples were collected during a saline infusion on a separate occasion. FSH, LH, Prl, TSH and GH plasma levels were measured with RIA. In pubertal subjects, a significant rise in the mean Prl levels was seen 90 min after melatonin as compared with those during saline infusion. The Prl melatonin response area was significantly lower in prepubertal treated subjects and significantly higher in pubertal ones compared with the respective controls. The mean GH values showed a significant decrease 120 min after melatonin only in prepubertal subjects; no significant variations were seen in 8 of 10 pubertal subjects, whereas in the last 2 a marked increase was observed. Finally, under these conditions, melatonin did not influence the basal FSH LH and TSH levels. These results seem to suggest that hypophyseal hormone reponses change with pubertal development.

Myoelectric effects of vasoactive intestinal peptide on rabbit small intestine

1983 ◽  
Vol 244 (1) ◽  
pp. G46-G51
Author(s):  
C. A. Sninsky ◽  
M. M. Wolfe ◽  
J. L. Martin ◽  
B. A. Howe ◽  
T. M. O'Dorisio ◽  
...  
Keyword(s):  
Vasoactive Intestinal Peptide ◽  
Venous Blood ◽  
Intestinal Secretion ◽  
Similar Rate ◽  
Myoelectric Activity ◽  
Rabbit Ileum ◽  
Blood Samples ◽  
Rabbit Small Intestine ◽  
The Mean ◽  
Potential Complex

Myoelectric recording techniques were used to study the motility of rabbit ileum during infusions of vasoactive intestinal peptide (VIP). VIP was infused intravenously at a rate of 300 pmol X kg-1 X h-1, and peripheral venous blood samples were obtained hourly for VIP assay. VIP was also infused intraluminally at a similar rate, and hourly portal vein blood samples were obtained for VIP assay. Alterations in motility were observed after both intravenous and intraluminal infusions of VIP. These alterations in motility consisted of the migrating action potential complex and repetitive bursts of action potentials. The VIP infusion rate used and the mean peripheral plasma VIP level of 267 +/- 29 pg/ml attained during intravenous VIP infusion were similar to those that induced intestinal secretion in other animal species. Portal venous VIP levels (93 +/- 21 pg/ml) were unchanged during the intraluminal infusion of VIP. These studies show that intravenous infusion of VIP causes alterations in motility of rabbit ileum. These alterations in motility with concomitant secretion of water and electrolytes may contribute to the diarrhea induced by VIP infusion. In addition, intraluminal infusion of VIP also induced alterations in myoelectric activity, which suggested that this peptide has a luminal effect as well as a hormonal effect.

High Plasma Levels of Human Chromogranin a and Adrenomedullin in Patients with Pheochromocytoma

2005 ◽  
Vol 91 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Dario Cotesta ◽  
Chiara Caliumi ◽  
Piero Alò ◽  
Luigi Petramala ◽  
Maria Gabriella Reale ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Biochemical Parameters ◽  
Chromogranin A ◽  
Solid Phase ◽  
High Plasma ◽  
Tumor Removal ◽  
Blood Samples ◽  
Adrenocortical Adenomas ◽  
Specific Radioimmunoassay ◽  
The Mean

Aims and background The aim of our study was to investigate the plasma chromogranin A (CgA) and adrenomedullin (AM) levels in patients with pheochromocytomas. Methods and study design We collected blood samples for measurement of plasma CgA and AM in 21 patients with pheochromocytomas, 43 healthy subjects and 26 patients with solid non-functioning adrenocortical adenomas. In 11 patients with pheochromocytomas plasma CgA and AM were measured again four weeks after tumor removal. CgA and AM were measured by means of a novel solid-phase two-site immunoradiometric assay based on monoclonal antibodies (CgA-RIA CT, CIS bio international) and by a specific radioimmunoassay (RIA, Phoenix Pharm. Inc.), respectively. Results The mean plasma CgA level (±SD) in patients with pheochromocytomas (204 ± 147.9 ng/mL) was significantly higher (P <0.001) than that in healthy subjects (41.6 ± 10.7 ng/mL) and in patients with non-functioning adrenocortical adenomas (47.3 ± 17.6 ng/mL). The mean plasma AM concentration (±SD) in patients with pheochromocytomas (27.5 ± 10.4 pg/mL) was significantly higher (P <0.001) than that in HS (13.8 ± 4.5 pg/mL) and in patients with non-functioning adrenocortical adenomas (16.6 ± 7.3 pg/mL). Plasma CgA levels correlated with plasma AM levels (r = 0.501; P <0.02) and with plasma metanephrine levels (r = 0.738; P <0.0001) in patients with pheochromocytomas. In 11 patients with pheochromocytomas plasma CgA and AM concentrations significantly decreased after tumor removal (P <0.001 for both). Circulating CgA and AM had a sensitivity of 76.2% and 81%, a specificity of 97.7% and 90.7%, and an accuracy of 91% and 88%, respectively. Conclusion This study demonstrates that circulating CgA and AM levels are increased in pheochromocytoma patients compared with healthy subjects and patients with non-functioning adrenocortical adenomas. Moreover, at the time of diagnosis plasma CgA levels correlated with plasma AM levels and with plasma metanephrine levels in all patients with pheochromocytomas. In conclusion, plasma CgA and AM concentrations may represent additional biochemical parameters for clinical monitoring of patients with pheochromocytomas.

Neuroimmunomodulation in Cancer Patients: Correlations between Melatonin and ß-Endorphin Blood Levels and T Helper/Suppressor Ratio

1988 ◽  
Vol 3 (2) ◽  
pp. 82-86 ◽  
Author(s):  
S. Barni ◽  
P. Lissoni ◽  
S. Crispino ◽  
G. Cattaneo ◽  
F. Rovelli ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Cancer Patients ◽  
Venous Blood ◽  
Blood Levels ◽  
Neoplastic Disease ◽  
Immune Functions ◽  
T Helper ◽  
Blood Samples ◽  
Neuroendocrine Control ◽  
Immune Dysfunctions

The pineal gland and opioid peptides play roles in the neuroendocrine control of immunity. Both neuroendocrine and immune dysfunctions have been observed in cancer but the importance of the altered secretion of neurohormones in the immunoincompetence of cancer patients has never been investigated. This study concomitantly evaluated neuroendocrine and immune functions in 40 patients with early or advanced neoplastic disease. In each patient, melatonin and β-endorphin blood levels and lymphocyte subtypes were determined on venous blood samples collected during the morning. Metastatic patients had lower melatonin levels and a lower T4/T8 ratio than patients without metastases but no significant correlation was found between melatonin and the T4/T8 ratio. β-endorphin levels appeared to be normal in all patients. These results suggest that melatonin and β-endorphin secretion have no role in determining immune dysfunctions in cancer.

Acute Effects of Various Chemotherapeutic Combinations on Hypophyseal and Pineal Hormone Secretions in Cancer Patients

1987 ◽  
Vol 73 (2) ◽  
pp. 181-185 ◽  
Author(s):  
Sandro Barni ◽  
Paolo Lissoni ◽  
Gabriele Tancini ◽  
Sergio Crispino ◽  
Franco Paolorossi ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Venous Blood ◽  
Endocrine System ◽  
Cytotoxic Drugs ◽  
Saline Infusion ◽  
Chemotherapeutic Drugs ◽  
Acute Effects ◽  
Blood Samples ◽  
Hormone Secretions ◽  
Zero Time

It is known that prolonged therapy with cytotoxic drugs may affect the endocrine system. The present study was carried out to establish whether administration of chemotherapeutic drugs acutely influences hypophyseal and pineal activities. Nineteen patients affected by solid tumors were included in the study, 5 of whom were treated with CMF, 4 with FEC, 4 with CEV, and 6 with CDDP. Cytotoxic drugs were intravenously administered. Venous blood samples were collected at zero time and at 30, 60, 120 and 180 min after drug administration. On a separate occasion, venous blood samples were drawn during a saline infusion only. In each sample FSH, LH, GH, PRL, TSH, Cortisol, melatonin and β-endorphin were determined by the RIA method. The only significant changes observed in this study were a rise in PRL and a decrease in β-endorphin after CDDP administration. Melatonin was enhanced after CDDP and CMF, and Cortisol decreased after CMF and FEC, but their variations were not statistically significant with respect to those seen during saline infusion.

Validation of Oxygen Saturation Monitoring in Neonates

2007 ◽  
Vol 16 (2) ◽  
pp. 168-178 ◽  
Author(s):  
Shyang-Yun Pamela K. Shiao ◽  
Ching-Nan Ou
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Venous Blood ◽  
Arterial Oxygen ◽  
Dissociation Curve ◽  
Oxyhemoglobin Dissociation Curve ◽  
Blood Samples ◽  
Arterial Blood ◽  
The Mean ◽  
Oxyhemoglobin Dissociation

•Background Pulse oximetry is commonly used to monitor oxygenation in neonates, but cannot detect variations in hemoglobin. Venous and arterial oxygen saturations are rarely monitored. Few data are available to validate measurements of oxygen saturation in neonates (venous, arterial, or pulse oximetric). •Purpose To validate oxygen saturation displayed on clinical monitors against analyses (with correction for fetal hemoglobin) of blood samples from neonates and to present the oxyhemoglobin dissociation curve for neonates. •Method Seventy-eight neonates, 25 to 38 weeks’ gestational age, had 660 arterial and 111 venous blood samples collected for analysis. •Results The mean difference between oxygen saturation and oxyhemoglobin level was 3% (SD 1.0) in arterial blood and 3% (SD 1.1) in venous blood. The mean difference between arterial oxygen saturation displayed on the monitor and oxyhemoglobin in arterial blood samples was 2% (SD 2.0); between venous oxygen saturation displayed on the monitor and oxyhemoglobin in venous blood samples it was 3% (SD 2.1) and between oxygen saturation as determined by pulse oximetry and oxyhemoglobin in arterial blood samples it was 2.5% (SD 3.1). At a Pao2 of 50 to 75 mm Hg on the oxyhemoglobin dissociation curve, oxyhemoglobin in arterial blood samples was from 92% to 95%; oxygen saturation was from 95% to 98% in arterial blood samples, from 94% to 97% on the monitor, and from 95% to 97% according to pulse oximetry. •Conclusions The safety limits for pulse oximeters are higher and narrower in neonates (95%–97%) than in adults, and clinical guidelines for neonates may require modification.

scholarly journals Accuracy and Precision of a Point-of-Care HbA1c Test

2019 ◽  
Vol 14 (5) ◽  
pp. 883-889
Author(s):  
William D. Arnold ◽  
Kenneth Kupfer ◽  
Randie R. Little ◽  
Meera Amar ◽  
Barry Horowitz ◽  
...  
Keyword(s):  
Whole Blood ◽  
Point Of Care ◽  
Venous Blood ◽  
Reference Laboratory ◽  
Test Results ◽  
Blood Samples ◽  
Accuracy And Precision ◽  
The Mean ◽  
Whole Blood Samples ◽  
Highly Correlated

Background: Point-of-care (POC) hemoglobin A1c (HbA1c) testing has advantages over laboratory testing, but some questions have remained regarding the accuracy and precision of these methods. The accuracy and the precision of the POC Afinion™ HbA1c Dx test were investigated. Methods: Samples spanning the assay range were collected from prospectively enrolled subjects at three clinical sites. The accuracy of the POC test using fingerstick and venous whole blood samples was estimated via correlation and bias with respect to values obtained by an NGSP secondary reference laboratory (SRL). The precision of the POC test using fingerstick samples was estimated from duplicate results by calculating the coefficient of variation (CV) and standard deviation (SD), and separated into its components using analysis of variance (ANOVA). The precision of the POC test using venous blood was evaluated from samples run in four replicates on each of three test cartridge lots, twice per day for 10 consecutive days. The SD and CV by study site and overall were calculated. Results: Across the assay range, POC test results from fingerstick and venous whole blood samples were highly correlated with results from the NGSP SRL ( r = .99). The mean bias was −0.021% HbA1c (−0.346% relative) using fingerstick samples and −0.005% HbA1c (−0.093% relative) using venous samples. Imprecision ranged from 0.62% to 1.93% CV for fingerstick samples and 1.11% to 1.69% CV for venous samples. Conclusions: The results indicate that the POC test evaluated here is accurate and precise using both fingerstick and venous whole blood.

ANNUAL VARIATIONS IN PLASMA LEVELS OF TESTOSTERONE AND LUTEINIZING HORMONE IN THE LABORATORY MALE MONGREL DOG

1980 ◽  
Vol 86 (3) ◽  
pp. 425-430 ◽  
Author(s):  
R. E. FALVO ◽  
L. R. DEPALATIS ◽  
J. MOORE ◽  
T. A. KEPIC ◽  
J. MILLER
Keyword(s):  
Plasma Levels ◽  
Plasma Concentrations ◽  
Significant Rise ◽  
Release Mechanism ◽  
Cyclic Pattern ◽  
Blood Samples ◽  
Annual Variations ◽  
Mongrel Dog ◽  
The Mean ◽  
Cyclic Changes

Blood samples, drawn every 15 days (September 1975–September 1976) from four laboratory-housed male mongrel dogs, were assayed by radioimmunoassay for levels of testosterone and LH in the plasma. The mean plasma concentrations of testosterone remained relatively constant for most of the year with the exception of a significant rise in late August and early September. Mean plasma levels of LH showed a cyclic pattern throughout the year which could be represented by a cosine function curve. However, this cyclic pattern of LH was not accompanied by cyclic changes in plasma levels of testosterone and there was no relationship between these two hormones during the period of 1 year. As the cyclic pattern of LH was altered, the plasma level of testosterone began to rise and reached its highest concentration. Since this alteration of the LH cycle occurred before the increased concentrations of testosterone, and since there was no relationship between these two hormones for the period of a year, we have concluded that there may be another hormone(s) involved which either alters the sensitivity of the canine testis to LH or alters the LH synthesis/release mechanism of the pituitary gland.

Alterations in circadian rhythm of serum thyrotropin in critically ill patients

1992 ◽  
Vol 127 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Nicola Custro ◽  
Vincenza Scafidi ◽  
Alberto Notarbartolo
Keyword(s):  
Circadian Rhythm ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Healthy Subjects ◽  
Serum Concentrations ◽  
Statistical Methodology ◽  
Blood Samples ◽  
The Mean ◽  
Disease Analysis ◽  
Serum Tsh

To evaluate the 24-h pattern of serum thyrotropin (TSH) in critically ill patients, we measured serum concentrations of TSH in blood samples collected every 2 h for 24 h from nine patients (six with malignancy, two with liver cirrhosis, one with chronic renal failure), who had subnormal levels of both triiodothyronine (T3) and thyroxine (T4), in the absence of history, symptoms or signs of thyroid disease. Analysis of the data, performed using a second-order inferential statistical methodology for rhythmometry (cosinor method), demonstrated that critically ill patients still had daily oscillations of serum TSH which significantly adapted to the function approximating the circadian rhythms (R2 = 74.3%). However, the mean level (mesor) in the rhythm of the patients was found to be significantly lower than that of healthy subjects (0.96 vs 2.18 mU/l); the amplitude of rhythmical daily variations also was lower in patients than in healthy subjects (0.23 vs 0.56 mU/l), even though the amplitude/mesor ratio was similar (23% vs 26%). Lastly, the highest level in the TSH rhythm of the patients was found to be in the late afternoon, in contrast to healthy subjects, who had a TSH surge after midnight. Although these alterations are consistent with the existence of a dysregulation at suprahypophyseal level in critically ill patients, it remains to be established whether the state of low T3 and T4 may be ascribed to anomalous circadian rhythm of TSH.

scholarly journals Neonatal and maternal platelet cytosolic calcium in normotensive and hypertensive pregnancies.

1994 ◽  
Vol 71 (1) ◽  
pp. F6-10 ◽  
Author(s):  
M D Kilby ◽  
F Broughton Pipkin ◽  
E M Symonds
Keyword(s):  
Gestational Hypertension ◽  
Venous Blood ◽  
Cytosolic Calcium ◽  
Significant Rise ◽  
Specific Factor ◽  
Pregnancy Induced Hypertension ◽  
Significant Difference ◽  
Induced Hypertension ◽  
The Mean ◽  
In Pregnancy

A prospective study investigated platelet cytosolic calcium in non-pregnant volunteers (n = 30) and samples from the umbilical veins of babies from both normotensive (n = 18) and hypertensive (n = 15) primigravidae, and their mothers. There was no significant difference between the neonatal umbilical venous platelet cytosolic calcium concentration (p[Ca2+]i) in babies born to normotensive primigravidae or to those whose pregnancies were complicated by gestational hypertension (88 x 9 (SE) 2 x 5) in normotensive primagravidae, 80 x 6 (2 x 8) in pregnancy induced hypertension without proteinuria, and 89 x 3 (3 x 2) nmol/l in pre-eclampsia. There was also no significant difference in the p[Ca2+]i from the umbilical veins of the pregnancies studied and those of non-pregnant female volunteers in the follicular phase of their menstrual cycle. This was despite a gradual and significant rise in p[Ca2+]i with increasing severity of disease in the mothers of the babies studied (119 x 9 (4 x 1) in normotensive primagravidae, 130 x 8 (7 x 3) in pregnancy induced hypertension without proteinuria, and 148 x 2 (4 x 5 ) nmol/l in pre-eclampsia). The mean maternal p[Ca2+]i in the three samples returned to concentrations comparable with those in non-pregnant subjects by 12 weeks after birth. These data demonstrate no significant difference between the mean p[Ca2+]i in non-pregnant women and those obtained from the umbilical venous blood of normotensive or hypertensive primigravidae. They suggest that the functional hypoactivity of neonatal platelets is probably not secondary to a decrease in basal p[Ca2+]i. They also suggest that the progressively raised p[Ca2+]i in normal and hypertensive pregnancies might be due to a pregnancy specific factor that does not cross the placenta,

Accuracy of Point of Care Testing in Patients on Dual Anticoagulation During Initiation of Anticoagulation or Bridging,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3360-3360
Author(s):  
Anja B Drebes ◽  
Paul Priest ◽  
Shaila Bates ◽  
Lida Moghaddam ◽  
Edward GD Tuddenham ◽  
...  
Keyword(s):  
Point Of Care ◽  
Venous Blood ◽  
Plasma Concentrations ◽  
Internal Quality ◽  
Point Of Care Testing ◽  
Blood Samples ◽  
The Mean ◽  
Group 2 ◽  
Therapeutic Doses ◽  
Group 1

Abstract Abstract 3360 Background: Point-of-care testing (POCT) is widely used for monitoring of the international normalized ratio (INR) in patients on oral anticoagulation with a vitamin-K antagonist (VKA) and numerous clinical studies have assessed the accuracy of this method in comparison with INR results from venous blood samples analysed in the laboratory. There is however a paucity of clinical data to support the use of POCT in patients on dual anticoagulation with low molecular weight heparin (LMWH) and a VKA during initiation of anticoagulation or bridging after a surgical procedure. Aim: To test the hypothesis whether therapeutic doses of LMWH interfere with INR measurements when using a POCT system during times of dual anticoagulation with LMWH and a VKA. To further investigate whether the effect is most pronounced once LMWH has reached peak plasma levels and less evident 10 hours and more after administration of LMWH. Methods: We prospectively collected 160 consecutive venous blood samples from patients on therapeutic doses of LMWH - Tinzaparin (175 IU/kg once daily) and a VKA commonly warfarin for INR testing in our laboratory. At the same time all patients had their INR determined on capillary blood collected by finger prick using a CoaguChek XS Pro and INR test strips with the same lot number (Roche Diagnostics Ltd, UK). 60 blood samples were collected within 3–6 hours after administration of LMWH (group 1) and 100 samples were collected 10 hours or more after the last injection of LMWH (group 2). For each sample the dose and time of the last injection of LMWH was recorded along with the time of the venepuncture and the result of the capillary INR. To ensure that we had a wide variation in the plasma concentrations of LMWH we carried out anti-Xa testing on a cross-section of venous samples The dosing advice for Warfarin was based on the INR result of the venous blood sample processed in the laboratory. Results: The correlation coefficient between the POCT INR and the laboratory INR was 0.98 in group 1 and 0.97 in group 2. In the Bland Altman analysis for group 1 the mean 95% confidence interval (CI) was 0.03 (range+/− 1.96 SD: −0.26 to +0.32) and for group 2 the mean 95% CI was 0.00 (range −0.28 to +0.29). These results are comparable to results of our internal quality control between POCT INR and laboratory INR in patients on VKA alone with a mean 95% CI of −0.02 (range −0.26 to +0.29). The mean INR was 1.8 by both methods in group 1 and 1.7 by both methods in group 2 and anti-Xa levels ranged from 0 to1.19 U/mL. A variation in the result of the POCT INR and laboratory INR of 0.5 or greater is thought to affect dosing decisions for Warfarin. Such a variation was observed in 3% (2/60) in group 1 and 2% (2/100) in group 2. Conclusion: There was good accuracy of the INR obtained with the POCT system used and this was not affected by the timing of the administration of LMWH in relation to testing. Disclosures: No relevant conflicts of interest to declare.

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