Serum Concentrations Of Peptide Research Articles

Influence of the Apelinergic System on Conduction Disorders in Patients after Myocardial Infarction.

There is a growing body of evidence for an important role of the apelinergic system in the modulation of cardiovascular homeostasis. The aim of our study was to (1) examine the relationship between apelin serum concentration at index myocardial infarction (MI) and atrioventricular conduction disorders (AVCDs) at 12-month follow-up, and (2) investigate the association between initial apelin concentration and the novel marker of post-MI scar (Q/QRS ratio) at follow-up. In 84 patients with MI with complete revascularization, apelin peptide serum concentrations for apelin-13, apelin-17, elabela (ELA) and apelin receptor (APJ) were measured on day one of hospitalization; at 12-month follow-up, 54 of them underwent thorough examination that included 12-lead electrocardiography (ECG), Holter ECG monitoring and echocardiography. The mean age was 58.9 years. At 12-month follow-up, AVCDs were diagnosed in 21.4% of subjects, with AV first-degree block in 16.7% and sinoatrial arrest in 3.7%. ELA serum concentration at index MI correlated positively with the occurrence of AVCD (p = 0.003) and heart rate (p = 0.005) at 12-month follow-up. The apelin-13 serum concentration at index MI correlated negatively with the Q/QRS ratio. The apelin peptide concentration during an acute phase of MI impacts the development of AVCD and the value of Q/QRS ratio in MI survivors.

Subtyping intractable functional constipation in children using clinical and laboratory data in a classification model.

Children with intractable functional constipation (IFC) who are refractory to traditional pharmacological intervention develop severe symptoms that can persist even in adulthood, resulting in a substantial deterioration in their quality of life. In order to better manage IFC patients, efficient subtyping of IFC into its three subtypes, normal transit constipation (NTC), outlet obstruction constipation (OOC), and slow transit constipation (STC), at early stages is crucial. With advancements in technology, machine learning can classify IFC early through the use of validated questionnaires and the different serum concentrations of gastrointestinal motility-related hormones. A hundred and one children with IFC and 50 controls were enrolled in this study. Three supervised machine-learning methods, support vector machine, random forest, and light gradient boosting machine (LGBM), were used to classify children with IFC into the three subtypes based on their symptom severity, self-efficacy, and quality of life which were quantified using certified questionnaires and their serum concentrations of the gastrointestinal hormones evaluated with enzyme-linked immunosorbent assay. The accuracy of machine learning subtyping was evaluated with respect to radiopaque markers. Of 101 IFC patients, 37 had NTC, 49 had OOC, and 15 had STC. The variables significant for IFC subtype classification, according to SelectKBest, were stool frequency, the satisfaction domain of the Patient Assessment of Constipation Quality of Life questionnaire (PAC-QOL), the emotional self-efficacy for Functional Constipation questionnaire (SEFCQ), motilin serum concentration, and vasoactive intestinal peptide serum concentration. Among the three models, the LGBM model demonstrated an accuracy of 83.8%, a precision of 84.5%, a recall of 83.6%, a f1-score of 83.4%, and an area under the receiver operating characteristic curve (AUROC) of 0.89 in discriminating IFC subtypes. Using clinical characteristics measured by certified questionnaires and serum concentrations of the gastrointestinal hormones, machine learning can efficiently classify pediatric IFC into its three subtypes. Of the three models tested, the LGBM model is the most accurate model for the classification of IFC, with an accuracy of 83.8%, demonstrating that machine learning is an efficient tool for the management of IFC in children.

Feature Tracking of Global Longitudinal Strain by Using Cardiovascular MRI Improves Risk Stratification in Heart Failure with Preserved Ejection Fraction

Background In heart failure with preserved ejection fraction (HFpEF), echocardiographic studies suggest that global longitudinal strain (GLS) has an impact on survival. Feature-tracking cardiovascular MRI also allows for strain analysis; however, to the knowledge of the authors, little is known about its prognostic value and whether it reflects severity of diffuse fibrosis, as assessed by cardiovascular MRI T1 mapping. Purpose To investigate the association between myocardial strain at cardiovascular MRI with extracellular volume by T1 mapping and outcome in participants with HFpEF. Materials and Methods In this secondary analysis of a prospective study (NCT03405987), consecutive participants with HFpEF underwent cardiovascular MRI between July 2012 and March 2018, including T1 mapping and three-dimensional strain analysis. Extracellular volume and strain results were assessed to determine if there was a correlation between these two factors. Cox regression was performed to determine the prognostic relevance of MRI-derived myocardial strain for a combined end point (events) of heart failure hospitalizations and cardiovascular death. Results In total, 206 consecutive participants with HFpEF (mean age, 71 years ± 8 [standard deviation]; 69% women) were included. Median myocardial global longitudinal strain (GLS) at MRI was -8.5% and showed low correlation with extracellular volume (r = 0.28; P = .003). A total of 109 events (53%) were recorded during a follow-up of 38 months ± 29. Participants with a GLS above the median had higher event rates (log-rank test, P < .001). By multivariable Cox regression analysis, GLS remained independently associated with outcome (hazard ratio, 1.06 per 1% strain increase; 95% confidence interval: 1.01, 1.11; P = .03) when corrected for risk factors including age, diabetes, renal function, N-terminal pro-b-type natriuretic peptide serum concentration, and right ventricular size and function. Conclusion In participants with heart failure with preserved ejection fraction, global longitudinal strain at cardiovascular MRI was correlated with extracellular volume by T1 mapping and was associated with cardiovascular events. © RSNA, 2020 Online supplemental material is available for this article.

The Differences in Postprandial Serum Concentrations of Peptides That Regulate Satiety/Hunger and Metabolism after Various Meal Intake, in Men with Normal vs. Excessive BMI.

The energy balance regulation may differ in lean and obese people. The purposes of our study were to evaluate the hormonal response to meals with varying macronutrient content, and the differences depending on body weight. Methods. The crossover study included 46 men, 21–58 years old, normal-weight and overweight/obese. Every subject participated in two meal-challenge-tests with high-carbohydrate (HC), and normo-carbohydrate (NC) or high-fat (HF) meals. Fasting and postprandial blood was collected for a further 240 min, to determine adiponectin, leptin and total ghrelin concentrations. Results. In normal-weight individuals after HC-meal we observed at 60min higher adiponectin concentrations (12,554 ± 1531 vs. 8691 ± 1070 ng/mL, p = 0.01) and significantly (p < 0.05) lower total ghrelin concentrations during the first 120 min, than after HF-meal intake. Fasting and postprandial leptin levels were significantly (p < 0.05) higher in overweigh/obese men. Leptin concentrations in normal-weight men were higher (2.72 ± 0.8 vs. 1.56 ± 0.4 ng/mL, p = 0.01) 180 min after HC-meal than after NC-meal intake. Conclusions. Our results suggest that in normal-body weight men we can expect more beneficial leptin, adiponectin, and total ghrelin response after HC-meal intake, whereas, in overweight/obese men, the HC-meal intake may exacerbate the feeling of hunger, and satiety may be induced more by meals with lower carbohydrate content.

Role of Pro-Brain Natriuretic Peptide Serum Concentration in the Detection of Pulmonary Hypertension in Patients With End-Stage Lung Diseases Referred for Lung Transplantation

BackgroundSerum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration is elevated in patients with pulmonary hypertension (PH); however, its role in the detection of PH associated with lung disease is not well established. AimThe aim of this study was to assess the value of NT-proBNP in the detection of PH in patients with end-stage lung disease (esLD) referred for lung transplantation. Materials and methodsThe study population consisted of 65 patients: 37 with idiopathic pulmonary fibrosis (IPF), 20 with chronic obstructive pulmonary disease, and 8 patients with other interstitial lung diseases (75% men, mean age 53.3 ± 9.5 years). Serum concentration of NT-proBNP was assessed with an immunoradiometric assay kit. The mean pulmonary artery pressure (mPAP) was measured using a Swan-Ganz catheter. PH was defined as mPAP ≥ 25 mm Hg. ResultsMedian NT-proBNP concentrations were significantly higher in patients with PH than in patients without PH: 139 (49–1236) pg/mL vs 67 (38–116) pg/mL, respectively; P = .016. Receiver operating characteristic (ROC) analysis revealed that NT-proBNP concentration higher than 131.5 pg/mL was a predictor of PH with good specificity (81%) and positive predictive value (78.9%) but low sensitivity (55.6%) and negative predictive value (58.6%). The area under the ROC curve of serum NT-proBNP concentration for PH was 0.71 (95% confidence interval 0.57–0.85, P = .039). ConclusionSerum concentration of NT-proBNP may be useful in the diagnosis of PH in patients with esLD referred for lung transplantation.

Transcription factor 7-like 2-gene polymorphism is related to fasting C peptide in latent autoimmune diabetes in adults (LADA)

Common polymorphisms in the transcription factor 7-like 2 gene (TCF7L2) have been associated with type 2 diabetes in different populations and recently with LADA, but not with type 1 diabetes. The aim of our study was to investigate association between the rs7903146 polymorphism in the TCF7L2 gene and LADA in Polish patients. Link between the "high risk for type 2 diabetes genotype" with clinical features was analyzed. 68 newly diagnosed patients with LADA and 195 healthy controls were genotyped for the rs7903146 polymorphism in the TCF7L2 gene using the PCR-based RFLP method. Fasting C peptide level was measured by ELISA. We observed increased frequencies of the TT genotype of the rs7903146 polymorphism in the TCF7L2 gene in LADA patients compared to controls (15 vs. 6%, P = 0.03). Fasting C peptide serum concentration was significantly lower in group of patients with LADA carrying the TT genotype (P < 0.01). In conclusion, the data from this study confirmed previous results showing genetic similarities between patients with LADA and type 2 diabetes. Non-autoimmune mechanism may be related to beta cell dysfunction in patients with LADA.

Atrial natriuretic peptide serum concentration decreases in donors undergoing discontinuous plasmapheresis involving a large extracorporeal blood volume

In donor plasmapheresis, circulatory reactions occur at a similar frequency as in whole-blood donation although the large extracorporeal blood volume (ECV) occurring during discontinuous plasmapheresis might predispose donors to hypovolemic reactions. The regulatory mechanisms compensating for this intradonation blood volume (BV) deficit are not well understood. It was the aim of this study to delineate whether atrial natriuretic peptide (ANP) is involved in the BV regulation of plasmapheresis donors. Because ANP regulates volume overload, it might decrease during BV decrease in plasmapheresis. ANP serum concentrations were determined in 60 donors undergoing discontinuous plasmapheresis. Samples were taken before the start of the procedure and when maximum ECV (ECV(max)) was reached at the end of the last withdrawal. Donors were randomly selected after stratification for sex and BV. In a control investigation, the same donors were kept in a reclined position for the duration of a plasmapheresis session without plasma withdrawal. ANP plasma concentration changes were correlated with changes of hemodynamic variables, which were recorded noninvasively with bioelectrical impedance cardiography. Median ANP concentration decreased from 13.0 to 8.4 pg per mL during donation and from 11.6 to 10.5 pg per mL during the control session. The mean control-adjusted ANP change due to plasma withdrawal was -2.62 pg per mL (p = 0.006). This decrease was not attributable to a dilution effect. ANP change did not correlate with changes of recorded hemodynamic variables. The decrease of the ANP serum concentration during plasmapheresis demonstrates that the ECV(max) constitutes a hypovolemic challenge of the donors, which elicits a neurohormonal regulatory mechanism aimed at maintaining cardiovascular homeostasis.

Assessing pulmonary permeability by transpulmonary thermodilution allows differentiation of hydrostatic pulmonary edema from ALI/ARDS

To test whether assessing pulmonary permeability by transpulmonary thermodilution enables to differentiate increased permeability pulmonary edema (ALI/ARDS) from hydrostatic pulmonary edema. Retrospective review of cases. A 24-bed medical intensive care unit of a university hospital. Forty-eight critically ill patients ventilated for acute respiratory failure with bilateral infiltrates on chest radiograph, a PaO(2)/FiO(2) ratio < 300 mmHg and extravascular lung water indexed for body weight >/= 12 ml/kg. We assessed pulmonary permeability by two indexes obtained from transpulmonary thermodilution: extravascular lung water/pulmonary blood volume (PVPI) and the ratio of extravascular lung water index over global end-diastolic volume index. The cause of pulmonary edema was determined a posteriori by three experts, taking into account medical history, clinical features, echocardiographic left ventricular function, chest radiography findings, B-type natriuretic peptide serum concentration and the time-course of these findings with therapy. Experts were blind for pulmonary permeability indexes and for global end-diastolic volume. ALI/ARDS was diagnosed in 36 cases. The PVPI was 4.7+/-1.8 and 2.1+/-0.5 in patients with ALI/ARDS and hydrostatic pulmonary edema, respectively (p<0.05). The extravascular lung water index/global end-diastolic volume index ratio was 3.0 x 10(-2)+/-1.2 x 10(-2) and 1.4 x 10(-2)+/-0.4 x 10(-2) in patients with ALI/ARDS and with hydrostatic pulmonary edema, respectively (p<0.05). A PVPI >/= 3 and an extravascular lung water index/global end-diastolic index ratio >/= 1.8 x 10(-2) allowed the diagnosis of ALI/ARDS with a sensitivity of 85% and specificity of 100%. These results suggest that indexes of pulmonary permeability provided by transpulmonary thermodilution may be useful for determining the mechanism of pulmonary edema in the critically ill.

A fragment of apolipoprotein B with insulin-like immunoreactivity

&#x0D; The purpose of this study was immunochemical analysis of a fragment of apolipoprotein В with insulin-like immunoreactivity. We denoted it as peptide B. The peptide isolated by electrophoretic elution was used to obtain specific antibodies. Antibodies to peptide В reacted with apolipoprotein B-100, whole serum, serum after precipitation of β-lipoproteins, and with supernatant after removal of all lipoproteins by ultracentrifugation. Enzyme immunoassay was optimized for evaluation of serum peptide В after precipitation of β-lipoproteins. Serum concentrations of peptide В were increased in patients with type 2 diabetes mellitus in comparison with donors. The content of peptide В increased with increase of body weight index and disease duration.

Dissociation of hemodynamic and renal effects of i.v. alpha-hANF (99-126) in conscious calves.

The effects of i.v. human atrial natriuretic factor (alpha-hANF [99-126]) was investigated in 5 conscious calves (age 4 months, weight 94 +/- 14kg) with constant fluid (300 ml/h) and sodium intake over a period of 24 hours before and during the 3 hours of experimentation. We administered 200 micrograms, 400 micrograms and 800 micrograms ANF at hourly intervals. Immediately (+2 min) after the i.v. injection the peptide's serum-concentration rose from, basal 13 +/- 3 to 802 +/- 191 (200 micrograms), 1707 +/- 419 (400 micrograms) and 3483 +/- 878 pmol/l (800 micrograms) (p < 0.0001), respectively. Mean arterial pressure decreased from, basal, 108 +/- 18 to 85 +/- 17, 76 +/- 16 and 69 +/- 18 mmHg (p < 0.0001), and central venous pressure decreased from, basal, 5.1 +/- 3 to 1.2 +/- 1, 0.4 +/- 1 and 0.8 +/- 2 mmHg (p < 0.001). Heart rate increased from, basal, 66 +/- 5 to 84 +/- 23, 111 +/- 29 and 114 +/- 13 b/min (p < 0.001). Following the administration of ANF the urine volume decreased from, basal, 261 +/- 145 to 195 +/- 72, 121 +/- 41 and 102 +/- 33 ml/h (p < 0.0041). The urinary sodium excretion rates decreased from, basal, 50 +/- 17 to 30 +/- 13, 22 +/- 10 and 19 +/- 10 mmol/h (p < 0.007), and the potassium excretion rates decreased from, basal, 43 +/- 19 to 39 +/- 16, 26 +/- 11 and 23 +/- 10 mmol/h (p < 0.0047). Endogenous clearance of creatinine (basal: 182 +/- 30 ml/min) did not change (260 +/- 84, 218 +/- 66 and 224 +/- 76 ml/h) following i.v. ANF. Inspite of this marked fluid retention, the hematocrit, expressed as relative change, was increased by 7.5%, 11.8% and 10.4%. In 2 calves we additionally measured an increased whole blood and plasma density possibly indicating increased liquid permeation to an extravascular compartment. Thus, in calves the hemodynamic effects of ANF are comparable to those seen in man. However, the failure of ANF to stimulate diuresis and natriuresis indicates a dissociation of hemodynamic and renal effects of ANF in calves.

Increased serum concentrations of procollagen type III peptide in severely injured patients

To determine the serum concentrations of procollagen type III peptide in severely injured patients with different outcomes and to evaluate the relationship between serum procollagen type III peptide concentrations, sources of increased posttraumatic fibrotic activity (wounds, lung, liver, kidney), and decreased elimination of procollagen type III peptide (liver). Prospective study. Surgical ICU, university hospital. Fifty-seven patients (mean injury severity score: 38.5 points, range 13 to 75 points), between 16 and 70 yrs of age, treated in our institution within 6 hrs after the accident. Serial measurements were started on admission and continued on a 6-hr basis. After 48 hrs, the monitoring interval was extended to 24 hrs until recovery (but at least until day 14) or death. At each point of evaluation, pulmonary and circulatory function parameters and chest radiographs (once a day) were evaluated, the results were recorded, and blood samples were drawn to determine procollagen type III peptide, total bilirubin, creatinine, gamma-glutamyl transferase, polymorphonuclear elastase, and other parameters. Statistic evaluation was done with the Wilcoxon test, Spearman rank correlation, and a multiple regression model. Mean procollagen type III peptide serum concentrations (+/- SD) were significantly different in patients who died (8.0 +/- 3.8 U/mL) compared with those patients who survived with organ failure (2.7 +/- 1.3 U/mL) or without complications (1.4 +/- 0.5 U/mL), respectively. Significant correlations of procollagen type III peptide concentrations with the serum bilirubin concentrations (r = .7), days with need of mechanical ventilation (r = .64), PaO2/FIO2 ratio (r = -.6), polymorphonuclear elastase (r = .6), serum creatinine concentrations (r = .55), and injury severity score (r = .33) were observed. There was a tendency toward higher serum procollagen type III peptide concentrations in patients with severe skeletal injuries. Serum procollagen type III peptide concentrations in severely injured patients may be considerably increased in correlation with injury severity and outcome. Procollagen type III peptide serum concentrations seem to reflect the sum of increased collagen formation from wound healing and fibrogenesis of mediator-related organ damage (especially lung) and decreased procollagen type III peptide excretion due to impaired liver function. Further data are necessary to evaluate the role of hepatic elimination in these patients.