scholarly journals The Circadian Rhythm of Copeptin, the C-Terminal Portion of Arginine Vasopressin

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Svetlana Beglinger ◽  
Jürgen Drewe ◽  
Mirjam Christ-Crain
Keyword(s):  
Circadian Rhythm ◽  
Healthy Subjects ◽  
Prospective Observational Study ◽  
Diagnostic Marker ◽  
Early Morning ◽  
Fasting Period ◽  
Mean Values ◽  
The Mean ◽  
Salt Homeostasis ◽  
Minor Extent

Background. Several studies have investigated copeptin as a prognostic marker of different acute diseases and as a diagnostic marker in disorders of water and salt homeostasis. However, no data of the normal circadian rhythm of copeptin in healthy subjects are available. Aim. To investigate the circadian rhythm of copeptin in healthy subjects under standardized conditions. Methods. 19 healthy volunteers aged 18 to 53 years, male and female, were studied in a prospective observational study. In all 19 participants, blood samples for copeptin were taken in regular intervals of 30 minutes for 24 hours after a fasting period of minimum 8 hours. Results. The mean values of copeptin showed a circadian rhythm, similar to that described for AVP release, with a trend towards higher levels (5.9±1 pmol/L) at night and early morning between 4 am and 6 am and lowest levels (2.3±0.2 pmol/L) in the late afternoon between 5 pm and 7 pm. This finding was only observed in individuals with initial higher copeptin levels, whereas in individuals with lower basal copeptin levels no circadian rhythm was observed. Conclusion. There is evidence for a circadian rhythm in copeptin release during 24 hours, however, of minor extent. These findings suggest that copeptin levels can be determined irrespectively of the time of the day.

scholarly journals The use of a neck brace does not influence visual vertical perception

2011 ◽  
Vol 69 (3) ◽  
pp. 509-512 ◽  
Author(s):  
Martha Funabashi ◽  
Natya N.L. Silva ◽  
Luciana M. Watanabe ◽  
Taiza E.G Santos-Pontelli ◽  
José Fernando Colafêmina ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Healthy Subjects ◽  
Afferent Input ◽  
Subjective Visual Vertical ◽  
Sensory Receptors ◽  
Ocular Torsion ◽  
Vertical Orientation ◽  
Mean Values ◽  
Visual Vertical ◽  
The Mean

Subjective visual vertical (SVV) evaluates the individual's capacity to determine the vertical orientation. Using a neck brace (NB) allow volunteers' heads fixation to reduce cephalic tilt during the exam, preventing compensatory ocular torsion and erroneous influence on SVV result. OBJECTIVE: To analyze the influence of somatosensory inputs caused by a NB on the SVV. METHOD: Thirty healthy volunteers performed static and dynamic SVV: six measures with and six without the NB. RESULTS: The mean values for static SVV were -0.075º±1.15º without NB and -0.372º±1.21º with NB. For dynamic SVV in clockwise direction were 1.73º±2.31º without NB and 1.53º±1.80º with NB. For dynamic SVV in counterclockwise direction was -1.50º±2.44º without NB and -1.11º±2.46º with NB. Differences between measurements with and without the NB were not statistically significant. CONCLUSION: Although the neck has many sensory receptors, the use of a NB does not provide sufficient afferent input to change healthy subjects' perception of visual verticality.

scholarly journals Effects of food and sucralfate on a single oral dose of 500 milligrams of levofloxacin in healthy subjects.

1997 ◽  
Vol 41 (10) ◽  
pp. 2196-2200 ◽  
Author(s):  
L J Lee ◽  
B Hafkin ◽  
I D Lee ◽  
J Hoh ◽  
R Dix
Keyword(s):  
Oral Dose ◽  
Healthy Subjects ◽  
High Fat ◽  
Time Curve ◽  
Mean Values ◽  
Treatment Groups ◽  
The Mean ◽  
The Individual ◽  
Individual Profiles ◽  
Fat Meal

The effects of food and sucralfate on the pharmacokinetics of levofloxacin following the administration of a single 500-mg oral dose were investigated in a randomized, three-way crossover study with young healthy subjects (12 males and 12 females). Levofloxacin was administered under three conditions: fasting, fed (immediately after a standardized high-fat breakfast), and fasting with sucralfate given 2 h following the administration of levofloxacin. The concentrations of levofloxacin in plasma and urine were determined by high-pressure liquid chromatography. By noncompartmental methods, the maximum concentration of drug in serum (Cmax), the time to Cmax (Tmax), the area under the concentration-time curve (AUC), half-life (t1/2), clearance (CL/F), renal clearance (CLR), and cumulative amount of levofloxacin in urine (Ae) were estimated. The individual profiles of the drug concentration in plasma showed little difference among the three treatments. The only consistent effect of the coadministration of levofloxacin with a high-fat meal for most subjects was that levofloxacin absorption was delayed and Cmax was slightly reduced (Tmax, 1.0 and 2.0 h for fasting and fed conditions, respectively [P = 0.002]; Cmax, 5.9 +/- 1.3 and 5.1 +/- 0.9 microg/ml [90% confidence interval = 0.79 to 0.94] for fasting and fed conditions, respectively). Sucralfate, which was administered 2 h after the administration of levofloxacin, appeared to have no effect on levofloxacin's disposition compared with that under the fasting condition. Mean values of Cmax and AUC from time zero to infinity were 6.7 +/- 3.2 microg/ml and 47.9 +/- 8.4 microg x h/ml, respectively, following the administration of sucralfate compared to values of 5.9 +/- 1.3 microg/ml and 50.5 +/- 8.1 microg x h/ml, respectively, under fasting conditions. The mean t1/2, CL/F, CLR, and Ae values were similar among all three treatment groups. In conclusion, the absorption of levofloxacin was slightly delayed by food, although the overall bioavailability of levofloxacin following a high-fat meal was not altered. Finally, sucralfate did not alter the disposition of levofloxacin when sucralfate was given 2 h after the administration of the antibacterial agent, thus preventing a potential drug-drug interaction.

scholarly journals Within-subject and between-subject biological variation estimates of 21 hematological parameters in 30 healthy subjects

2018 ◽  
Vol 56 (8) ◽  
pp. 1309-1318 ◽  
Author(s):  
Abdurrahman Coşkun ◽  
Anna Carobene ◽  
Meltem Kilercik ◽  
Mustafa Serteser ◽  
Sverre Sandberg ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Complete Blood Count ◽  
Hematological Parameters ◽  
Hemoglobin Concentration ◽  
Biological Variation ◽  
Mean Corpuscular Hemoglobin ◽  
Mean Values ◽  
Performance Specifications ◽  
The Mean ◽  
Variance Homogeneity

Abstract Background: The complete blood count (CBC) is used to evaluate health status in the contexts of various clinical situations such as anemia, infection, inflammation, trauma, malignancies, etc. To ensure safe clinical application of the CBC, reliable biological variation (BV) data are required. The study aim was to define the BVs of CBC parameters employing a strict protocol. Methods: Blood samples, drawn from 30 healthy subjects (17 females, 13 males) once weekly for 10 weeks, were analyzed using a Sysmex XN 3000 instrument. The data were assessed for normality, trends, outliers and variance homogeneity prior to coefficient of variation (CV)-analysis of variance (ANOVA). Sex-stratified within-subject (CVI) and between-subjects (CVG) BV estimates were determined for 21 CBC parameters. Results: For leukocyte parameters, with the exception of lymphocytes and basophils, significant differences were found between female/male CVI estimates. The mean values of all erythrocyte-, reticulocyte- and platelet parameters differed significantly between the sexes, except for mean corpuscular hemoglobin concentration, mean corpuscular volume and platelet numbers. Most CVI and CVG estimates appear to be lower than those previously published. Conclusions: Our study, based on a rigorous protocol, provides updated and more stringent BV estimates for CBC parameters. Sex stratification of data is necessary when exploring the significance of changes in consecutive results and when setting analytical performance specifications.

scholarly journals Backup ventilation during neurally adjusted ventilatory assist in preterm infants

2021 ◽  
Author(s):  
JUYOUNG LEE ◽  
Vilhelmiina Parikka ◽  
Liisa Lehtonen ◽  
Hanna Soukka
Keyword(s):  
Respiratory Rate ◽  
Preterm Infants ◽  
Prospective Observational Study ◽  
Clinical Deterioration ◽  
Neurally Adjusted Ventilatory Assist ◽  
Mean Values ◽  
Ventilatory Assist ◽  
Postmenstrual Age ◽  
Acute Increase ◽  
The Mean

Objective: To analyze the proportion of backup ventilation during neurally adjusted ventilatory assist (NAVA) in preterm infants at different gestational ages and to analyze the trends in backup ventilation in relation to clinical deteriorations. Methods: A prospective observational study was conducted in 18 preterm infants born at a median (range) 27 (23–34) weeks of gestation with a median (range) birth weight of 1,100 (460–2,820) g, who received respiratory support with either invasive or noninvasive NAVA. Data on ventilator settings and respiratory variables were collected daily; the mean values of each 24-hour recording were computed for each respiratory variable. For clinical deterioration, ventilator data were reviewed at 6-hour intervals for 30 hours prior to the event. Results: A total of 354 ventilator days were included: 269 and 85 days during invasive and noninvasive NAVA, respectively. The time on backup ventilation (%/min) significantly decreased, and the neural respiratory rate increased with increasing postmenstrual age during both invasive and noninvasive NAVA. The median time on backup ventilation was less than 15%/min, and the median neural respiratory rate was more than 45 breaths/min for infants above 26 weeks of gestation during invasive NAVA. The relative backup ventilation significantly increased prior to the episode of clinical deterioration. Conclusion: The proportion of backup ventilation during NAVA showed how the control of breathing matured with increasing gestational age. Even the most immature infants triggered most of their breaths by their own respiratory effort. An acute increase in the proportion of backup ventilation anticipated clinical deterioration.

Hyperhomocysteinemia in pre-eclampsia: is routine screening rational?

2017 ◽  
Vol 6 (4) ◽  
pp. 1271
Author(s):  
Sonia Miglani ◽  
Ruchira Nautiyal ◽  
Archana Prakash
Keyword(s):  
Prospective Observational Study ◽  
Placental Abruption ◽  
Vascular Diseases ◽  
Maternal Serum ◽  
Control Group ◽  
P Value ◽  
Routine Test ◽  
Mean Values ◽  
Serum Homocysteine ◽  
The Mean

Background: Hypertensive disorders complicate upto 5 to 10% of all pregnancies. Though the exact cause of pre-eclampsia is still undecided, maternal hyperhomocysteinemia has been implicated as a risk factor for pre eclampsia, placental abruption and other vascular diseases. The objectives of present study were to estimate the levels of serum homocysteine in antenatal patients and to study the above parameters in patients of pre-eclampsia.Methods: A prospective observational study was performed with 30 pre eclamptic patients and an equal number taken as control having comparable demographic characteristics. Level of homocysteine was measured by an enzymatic method, using Diazyme homocysteine 2 reagent enzymatic assay kit on Beckman coulter analyzer in all the patients. Obstetrics and neonatal outcomes were observed in all the patients. The statistical analysis was done using unpaired T test for determining level of significance.Results: Mean Serum homocysteine in the study group was 13.99±5.46 µmol/l and was 6.03±2.58 µmol/l in control group. This was statistically significant (p value 0.002). However the mean values of serum homocysteine did not correlate with severity of pre-eclampsia 14.32±6.72 µmol/l in mild pre-eclampsia and 13.60±3.77μmol/l in severe pre-eclampsia respectively (p value - 0.727).Conclusions: It appears that maternal serum homocysteine has a causal role in pathogenesis of pre eclampsia, however to recommend it as a routine test, larger studies are required.

Variability of resting respiratory drive and timing in healthy subjects

1988 ◽  
Vol 65 (1) ◽  
pp. 309-317 ◽  
Author(s):  
M. J. Tobin ◽  
M. J. Mador ◽  
S. M. Guenther ◽  
R. F. Lodato ◽  
M. A. Sackner
Keyword(s):  
Standard Deviation ◽  
Healthy Subjects ◽  
Breathing Pattern ◽  
Respiratory Drive ◽  
Inspiratory Time ◽  
Mean Values ◽  
Coefficients Of Variation ◽  
The Mean ◽  
Older Subjects ◽  
Young Subjects

Studies of breathing pattern have focused primarily on changes in the mean values of the breathing pattern components, whereas there has been minimal investigation of breath-to-breath variability, which should provide information on the constancy with which respiration is controlled. In this study we examined the variability of breathing pattern both on a breath-to-breath and day-to-day basis by calculating the coefficient of variation (i.e., the standard deviation expressed as a percentage of the mean). By examining breath-to-breath data, we found that the coefficients of variation of tidal volume (VT) and fractional inspiratory time (TI/TT, an index of timing) obtained with an inductive plethysmograph and spirometer were within 1% of each other. Examination of breath-to-breath variability in breathing pattern over a 15-min period in 65 subjects revealed large coefficients of variation, indicating the need to base calculations on a relatively large number of breaths. Less breath-to-breath variability was observed in respiratory frequency [f, 20.8 +/- 11.5% (SD)] and TI/TT (17.9 +/- 6.5%) than in VT (33 +/- 14.9%) and mean inspiratory flow (VT/TI, an index of drive; 31.6 +/- 12.6%; P less than 0.0001). Older subjects (60-81 yr) displayed greater breath-to-breath variability than young subjects (21-50 yr). Use of a mouthpiece did not affect the degree of variability.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

STUDIES ON THE PATTERN OF CIRCULATING STEROIDS IN THE NORMAL MENSTRUAL CYCLE

1977 ◽  
Vol 84 (2) ◽  
pp. 320-332 ◽  
Author(s):  
A. R. Aedo ◽  
M. Nuñez ◽  
B.-M. Landgren ◽  
S. Z. Cekan ◽  
E. Diczfalusy
Keyword(s):  
Circadian Rhythm ◽  
Plasma Levels ◽  
Circadian Variation ◽  
Circadian Variations ◽  
Mean Values ◽  
Normal Menstrual Cycle ◽  
Menstruating Women ◽  
The Mean ◽  
The Difference ◽  
The Individual

ABSTRACT Circadian variations of the plasma levels of dehydroepiandrosterone, 17-hydroxypregnenolone, pregnenolone and testosterone were investigated by radioimmunoassay in 10 normally menstruating women during the periovulatory period. In seven of the subjects it was also possible to estimate androstenedione and dihydrotestosterone levels. Blood was withdrawn continuously over a period of 48 h at a rate of 4 ml/h by means of a non-thrombogenic pump. The circadian rhythm was studied during 13 3-hour sampling periods (39 h) which were identical in all subjects. Dehydroepiandrosterone, 17-hydroxypregnenolone and pregnenolone showed a marked circadian rhythm with highest mean levels in the morning between 06.00 and 09.00 h and lowest mean levels during the night between 21.00 and 24.00 h. The peak levels of individual subjects coincided completely with the highest mean levels in the case of dehydroepiandrosterone, in 9 out of 10 cases with regard to 17-hydroxypregnenolone and in 8 of 10 cases as far as pregnenolone levels were concerned. The lowest individual levels were more dispersed around the means than were the individual peaks. The difference between the highest (morning hours: 06.00–09.00) and lowest (evening hours: 21.00–24.00) geometeric mean values was 404% for 17-hydroxypregnenolone, 163 % for dehydroepiandrosterone and 71 % for pregnenolone. The mean testosterone levels also exhibited an elevation between 06.00 and 09.00 h which was significant (P < 0.05). However, the individual peak values were scattered from 21.00 h of the first day to 18.00 h of the second day. The mean concentrations of androstenedione showed a significant increase between 06.00 and 18.00 h. The individual peaks were widely dispersed. Hence a uniform circadian rhythm correlated to the levels of the Δl5-steroids mentioned above could not be demonstrated in the case of testosterone and androstenedione. An analysis of variance indicated no significant differences between sampling periods as far as dihydrotestosterone levels were concerned. The extent and regularity of the circadian variation in the plasma levels of the Δl5-steroids studied makes it mandatory to standardize very carefully the exact time of blood withdrawal in any longitudinal study. In view of the sharp changes in the plasma levels during the morning hours, it is suggested that sampling during the afternoon period may provide more constant values.

scholarly journals Validity of Autotaxin as a Novel Diagnostic Marker for Liver Fibrosis in Egyptian Chronic HCV Patients

2013 ◽  
Vol 1 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Wafaa M. Ezzat ◽  
Halla M. Ragab ◽  
Nabila Abd El Maksoud ◽  
Nour A. Abdulla ◽  
Yasser A. Elhosary
Keyword(s):  
Liver Fibrosis ◽  
Diagnostic Marker ◽  
Fibrosis Score ◽  
Laboratory Assessment ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean ◽  
Group 2 ◽  
Chronic Hcv ◽  
Group 1

We aimed to detect the validity of serum ATX as a diagnostic marker for liver fibrosis. Forty-eight males and 16 females were enrolled in the current study. Their ages ranged from 29-57 years with mean of 45.09, all were chronically HCV infected. Laboratory assessment was done for all subjects in form of complete blood picture; liver function test; lipid profile and serum detection of ATX. Patients were grouped according to the stage of fibrosis into group 1: fibrosis score 0, 1, 2, 3; group 2: fibrosis score: 4, 5, 6.The mean values of ATX in all studied patients with chronic HCV infection was 63.02 ± 36.29 while that of healthy controls was 65.31 ± 12.24 without any significant difference. Surprisingly, mean values of ATX were higher among patients with group 1 but it did not reach the significant level. In each group of them, the differences between mean values of ATX among different grades of liver fibrosis were insignificant. It was also noticed that the mean values of ATX were higher among men than in women .It was concluded that Autotoxin might not be used as a useful diagnostic marker for liver fibrosis in Egyptian chronic HCV patients.

Insulin Resistance and Hyperinsulinemia in Patients with Chronic Liver Disease and Hepatocellular Carcinoma

2009 ◽  
Vol 2 ◽  
pp. CMED.S3116 ◽  
Author(s):  
Valter Donadon ◽  
Massimiliano Balbi ◽  
Antonio Perciaccante ◽  
Pietro Casarin ◽  
Giorgio Zanette
Keyword(s):  
Hepatocellular Carcinoma ◽  
Insulin Resistance ◽  
Liver Disease ◽  
Chronic Liver Disease ◽  
Healthy Subjects ◽  
Chronic Liver ◽  
Metabolic Factors ◽  
Mean Values ◽  
The Mean

Objectives To investigate the role of insulin resistance (IR) and insulin plasma levels (IRI) in patients with chronic liver disease (CLD) and hepatocellular carcinoma (HCC). Methods We recruited the following patients: 125 with HCC, 128 with liver cirrhosis (LC) and 133 with chronic hepatitis C (CHC). IR was assessed by the HOMA-IR method. To define IR and hyperinsulinemia we selected as a cut-off level, the value of the 80th percentile for HOMA-IR (2.72) and IRI (11.18) in 113 healthy subjects. Results The mean levels of HOMA-IR and IRI increase progressively among CHC (2.7 ± 2.9 and 11.5 ± 10.5, respectively), LC (5.4 ± 4.5 and 17.6 ± 11.2) and HCC (6.4 ± 9.8 and 18.2 ± 18.8). In the upper quintiles for HOMA-IR and IRI, the frequency of patients in the LC and HCC groups was twice as much in CHC cases. HCC with DM2 have the greatest percentage above the 80th percentile of HOMA-IR, their quintiles distribution is inverted and HOMA-IR mean values are significantly higher in comparison with HCC without DM2 cases. Discussion Our study shows that the association between IR and CLD begins in the early stages of liver fibrosis. DM2 increases HOMA-IR and IRI mean levels in HCC patients and these metabolic factors could play a major role in the link between diabetes mellitus and hepatocarcinoma.

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