ABSTRACT
It is unclear if AGEs are involved in the bone fragility of type 1 diabetes (T1D). We evaluated whether skin AGEs by skin autofluorescence and serum AGEs (pentosidine, carboxymethyl-lysine [CML]) are independently associated with BMD by DXA (lumbar spine, hip, distal radius), trabecular bone score (TBS), serum bone turnover markers (BTMs: CTX; P1NP; osteocalcin), and sclerostin in participants with and without T1D. Linear regression models were used, with interaction terms to test effect modification by T1D status. In participants with T1D, correlations between skin and serum AGEs as well as between AGEs and 3-year HbA1C were evaluated using Spearman's correlations. Data are mean ± SD or median (interquartile range). We included individuals who participated in a cross-sectional study and had BMD and TBS assessment (106 T1D/65 controls, 53.2% women, age 43 ± 15 yr, BMI 26.6 ± 5.5 kg/m2). Participants with T1D had diabetes for 27.6 ± 12.3 yr, a mean 3-yr HbA1C of 7.5 ± 0.9% and skin AGEs of 2.15 ± 0.54 arbitrary units. A subgroup of 65 T1D/57 controls had BTMs and sclerostin measurements, and those with T1D also had serum pentosidine (16.8[8.2-32.0] ng/mL) and CML [48.0 ± 16.8] ng/mL) measured. Femoral neck BMD, TBS, and BTMs were lower, while sclerostin levels were similar in participants with T1D vs controls. T1D status did not modify the associations between AGEs and bone outcomes. Skin AGEs were significantly associated with total hip and femoral neck BMD, TBS, BTMs, and sclerostin before, but not after, adjustment for confounders. Serum AGEs were not associated with any bone outcome. There were no significant correlations between skin and serum AGEs or between AGEs and 3-yr HbA1C. In conclusion, skin and serum AGEs are not independently associated with BMD, TBS, BTMs, and sclerostin in participants with relatively well-controlled T1D and participants without diabetes.
ABSTRACT
Purpose: Paget's disease of bone (PDB) is a focal metabolic bone disorder characterized by an increased bone remodeling. Fifteen to 40 % of PDB patients have a familial form with an autosomal dominant inheritance. Disease-causing mutations of the SQSTM1 gene have been linked to PDB in about 40 % of families whereas genes linked to the remaining families are unknown. Several single nucleotide polymorphisms (SNPs) have been associated with PDB in unrelated patient non-carriers of a SQSTM1 mutation. The current clinical practice guidelines still recommend the measure of serum total alkaline phosphatase (sALP) for PDB screening. In unrelated individual non-carriers of SQSTM1 mutations, we previously developed a genetic test combining male sex with five genetic markers (rs499345, rs5742915, rs2458413, rs3018362, rs2234968), giving rise to an area under the curve (AUC) for PDB phenotype of 0.73 (0.69; 0.77). A combination of male sex with total calcium corrected for albumin and Procollagen type I N-terminal propeptide (P1NP), had an AUC of 0.82 (0.73; 0.92). Combining both genetic and biochemical tests increased the AUC to 0.89 (0.83; 0.95). Objective: This study aimed at estimating the performance of our previous test of PDB, in families not linked to SQSTM1 mutations with disease-causing genes yet unknown, and at developing a new algorithm if the performance is not satisfactory. Methods: We genotyped the five SNPs cited above, and measured calcium corrected for albumin and P1NP in 181 relatives, with PDB or not, from 19 PDB families not linked to SQSTM1 mutations. Bivariate and multivariate logistic regression models including male sex were fitted to search for a molecular test that could best detect PDB in these families. A receiving operating characteristics analysis was done to establish a cut-off point for continuous variables. Results: Logistic regression estimates of our previous molecular test gave rise to a high sensitivity of 78 %, 97 % and 88 % for the genetic, biochemical, and combined test but the specificity was very low, 35 %, 11 % and 21 %, respectively. This poor specificity persisted even when the cut-off point was changed. We then generated in these families, new logistic regression estimates but on the same parameters as mentioned above, giving rise to an AUC of 0.65 (0.55; 0.75) for the genetic test, of 0.84 (0.74; 0.94) for the biochemical test, and 0.89 (0.82; 0.96) for the combination test, the latter having a sensitivity of 96 % and specificity of 57 %. By comparison serum P1NP alone gave rise to an AUC of 0.84 (0.73; 0.94), with a sensitivity of 71 % and a specificity of 79 %. Conclusion: In PDB families not linked to SQSTM1 mutations, the estimates of our previous molecular test gave rise to a poor specificity. Using new estimates, the biochemical and combined tests have similar predictive abilities than our former test. Serum P1NP is a bone marker of interest for the screening for PDB in families not linked to SQSTM1 mutations.
ABSTRACT
The adult bone is continuously being remodelled to repair microdamage, preserve bone strength and mechanical competence as well as maintain calcium homeostasis. Bone turnover markers are products of osteoblasts (bone formation markers) and osteoclasts (bone resorption markers) providing a dynamic assessment of remodelling (turnover). Resorption-specific bone turnover markers are typically degradation products of bone collagen molecules (N- [NTX] and C-telopeptide cross-linked type 1 collagen [CTX]), which are released into the circulation and excreted in urine; or enzymatic activities reflecting osteoclastic resorption, tartrate-resistant acid phosphatase [TRACP]. Formation-specific bone turnover markers embrace different osteoblastic activities: type 1 collagen synthesis (Procollagen type I N- propeptide [PINP]), osteoblast enzymes (bone-specific alkaline phosphatase [BALP]), or bone matrix proteins [osteocalcin]. Among individuals not receiving osteoporosis treatment, resorption and formation markers are tightly linked and highly correlated (r = 0.6-0.8). Significant biological variability was reported in the past, but these issues have been greatly improved with automated assays and attention to pre-analytical and analytical factors that are known to influence bone turnover marker levels. Bone turnover markers are not useful in the diagnosis of osteoporosis, the individual prediction of bone loss, fracture, or rare complications, or in the selection of pharmacological treatment. Despite remaining issues with reference intervals and assays harmonization, bone turnover markers have proven to be useful in elucidating the pharmacodynamics and effectiveness of osteoporosis medications in clinical trials. As an alternative to BMD testing, BTMs may be useful to monitor osteoporosis therapies.
Subject(s)
Collagen Type I , Osteoporosis , Adult , Humans , Procollagen , Peptide Fragments , Biomarkers/metabolism , Osteoporosis/diagnosis , Osteoporosis/drug therapy , Bone Remodeling , Alkaline Phosphatase , Bone DensityABSTRACT
CONTEXT: Vertebral fracture (VF) prevalence up to 24% has been reported among young people with type 1 diabetes (T1D). If this high prevalence is confirmed, individuals with T1D could benefit from preventative VF screening. OBJECTIVE: We compared the prevalence of VFs between adults with T1D and nondiabetic controls. METHODS: This cross-sectional study included 127 adults with T1D, and 65 controls with a similar age, sex, and BMI distribution, from outpatient clinics of 2 tertiary care centers. Vertebral fracture assessment (VFA) by dual-energy x-ray absorptiometry (DXA) was used for prevalent VFs. The modified algorithm-based qualitative (mABQ) method was applied. Bone mineral density (BMD) and trabecular bone score (TBS) were assessed by DXA. Serum bone turnover markers and sclerostin were measured in a subgroup of participants. RESULTS: Participants with T1D (70 women, 57 men) had a mean age of 42.8â ±â 14.8 years, median diabetes duration of 25.8 (15.8-34.4) years, mean BMI of 26.6â ±â 5.4 kg/m2 and mean HbA1c over the past 3 years of 7.5â ±â 0.9%. Controls (35 women, 30 men) had mean age of 42.2â ±â 15.9 years and mean BMI of 26.1â ±â 5.1 kg/m2. VF prevalence was comparable between groups (2.4% vs 3.1%, Pâ =â 0.99). TBS, BMD at the total hip and femoral neck, and bone formation and resorption markers were lower while sclerostin levels were similar in participants with T1D vs controls. CONCLUSION: Our VFA results using the mABQ method do not confirm increased prevalence of VFs in men and women with relatively well-controlled T1D.
Subject(s)
Diabetes Mellitus, Type 1 , Osteoporotic Fractures , Spinal Fractures , Absorptiometry, Photon/methods , Adolescent , Adult , Bone Density , Cross-Sectional Studies , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/epidemiology , Female , Humans , Male , Middle Aged , Osteoporotic Fractures/epidemiology , Prevalence , Spinal Fractures/diagnostic imaging , Spinal Fractures/epidemiology , Spinal Fractures/etiologyABSTRACT
Paget's disease of bone (PDB) is a common chronic bone disorder. In the French-Canadian population, the p.Pro392Leu mutation within the SQSTM1 gene is involved in 46% of familial forms. In New Zealand, the emergence of PDB in offspring inheriting SQSTM1 mutations was reported to be delayed by a decade compared to their parents. We aimed at assessing the clinical phenotype of offspring carriers of this mutation in our French-Canadian cohort. We reviewed research records from adult offspring carriers of this mutation aged <90 years and their affected parents. In parents, we collected data on sex, age at diagnosis, number of affected bones, total serum alkaline phosphatase levels (tALPs) at diagnosis. In offspring, PDB extended phenotype assessment relying on tALPs, bone specific alkaline phosphatase levels (bALPs), procollagen type 1 amino-terminal propeptide (P1NP), whole body bone scan and skull and pelvis radiographs, was performed at inclusion from 1996 to 2009 and updated in 2016 to 2018, if not done during the past 8 years. The results showed that among the 36 offspring with an updated phenotype, four of them developed a clinical phenotype of PDB characterized by monostotic or polyostotic increased bone uptake associated with typical radiographic lesions in the affected sites, representing an incidence of 1.83 per 1000 person-years. Moreover, the age at PDB diagnosis was delayed by at least 10 years in the adult offspring carriers of the p.Pro392Leu mutation versus their affected parents. Our findings support the utility of a regular monitoring of the adult offspring without PDB but carriers of this mutation.
ABSTRACT
BACKGROUND: Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. However, catheter ablation of persistent atrial fibrillation is still a challenge. Various relatively complex ablation strategies exist and their results are not very favorable. Therefore, the aim of our study was to evaluate a well-defined reasonable approach to catheter ablation of persistent atrial fibrillation. The strategy consisted of a circumferential pulmonary vein ablation in combination with a linear lesion at the roof of the left atrium. METHODS: A total of 150 patients with symptomatic persistent atrial fibrillation were enrolled in this study. All patients underwent catheter ablation of persistent atrial fibrillation using the abovementioned approach. RESULTS: The ablation procedure could be performed as planned in all 150 patients. Five years after catheter ablation, the success rate was 71.3% (no arrhythmia recurrence in 107 out of 150 patients). There were no major complications during long-term follow-up. CONCLUSION: Catheter ablation of persistent atrial fibrillation can be performed safely and effectively using this ablation strategy providing favorable long-term follow-up results.
Subject(s)
Atrial Fibrillation , Catheter Ablation , Pulmonary Veins , Aged , Female , Heart Atria , Humans , Male , Middle Aged , Recurrence , Treatment OutcomeABSTRACT
Depending on populations, 15 to 40% of patients have a familial form of Paget's disease of bone (PDB), which is transmitted in an autosomal-dominant mode of inheritance with incomplete penetrance. To date, only SQSTM1 gene mutations have been linked to the disease. Several single nucleotide polymorphisms (SNPs) have been associated with PDB in patient non-carriers of SQSTM1 mutations, but they have minor size effects. The current clinical practice guidelines still recommend to measure total serum alkaline phosphatase (sALP) for PDB screening. However, genetic or bone biomarkers alone may lack sensitivity to detect PDB. Thus, the objective of this study was to develop a molecular test of PDB, combining genetic and bone biomarkers, in order to detect PDB, which is frequently asymptomatic. We genotyped 35 SNPs previously associated with PDB in 305 patients, and 292 healthy controls. In addition, serum levels of 14 bone biomarkers were assayed in 51 patients and 151 healthy controls. Bivariate and multivariate logistic regression models with adjustment for age and sex were fitted to search for a combination of SNPs and/or bone biomarkers that could best detect PDB in patient non-carriers of SQSTM1 mutations. First, a combination of five genetic markers gave rise to the highest area under the ROC curve (AUC) with 95% confidence interval [95% CI] of 0.731 [0.688; 0.773], which allowed us to detect 81.5% of patients with PDB. Second, a combination of two bone biomarkers had an AUC of 0.822 [0.726; 0.918], and was present in 81.5% of patients with PDB. Then, the combination of the five genetic markers and the two bone biomarkers increased the AUC up to 0.892 [0.833; 0.951], and detected 88.5% of patients with PDB. These results suggested that an algorithm integrating first a screen for SQSTM1 gene mutations, followed by either a genetic markers combination or a combined genetic and biochemical markers test in patients non-carrier of any SQSTM1 mutation, may detect the PDB phenotype better than biomarkers already available in the clinical practice.
Subject(s)
Genetic Techniques , Osteitis Deformans/diagnosis , Osteitis Deformans/genetics , Adaptor Proteins, Signal Transducing/genetics , Aged , Biomarkers/metabolism , Cohort Studies , DNA Mutational Analysis , Female , Genetic Association Studies , Genetic Markers , Genetic Predisposition to Disease , Humans , Male , Mutation/genetics , Polymorphism, Single Nucleotide/genetics , ROC Curve , Sequestosome-1 ProteinABSTRACT
PROBLEM: Women with antiphospholipid syndrome (APS) are at risk for pregnancy complications. Antiphospholipid antibodies (aPL) alter trophoblast function by triggering an inflammatory cytokine response; modulating angiogenic factor secretion; and inhibiting migration. While patients with APS are often treated with hydroxychloroquine (HCQ), its effect on trophoblast function is poorly understood. METHOD OF STUDY: A human first trimester trophoblast cell line was treated with or without antihuman ß2GPI mAbs in the presence or absence of HCQ. Supernatants were analyzed by ELISA. Cell migration was measured using a colormetric assay. RESULTS: Antiphospholipid antibodies-induced trophoblast IL-8, IL-1 ß, PlGF, and sEndoglin secretion were not altered by HCQ. aPL-induced inhibition of trophoblast migration was partially reversed by HCQ, even though HCQ significantly increased secretion of pro-migratory IL-6 to greater than baseline. aPL-induced upregulation of TIMP2 appears to inhibit trophoblast migration; the inability of HCQ to prevent aPL-induced TIMP2 may explain why migration was only partially restored. CONCLUSION: Hydroxychloroquine reversed the aPL-inhibition of trophoblast IL-6 secretion and partially limited aPL-inhibition of cell migration. Thus, some form of combination therapy that includes HCQ may be beneficial to pregnant APS patients.
Subject(s)
Antibodies, Antiphospholipid/metabolism , Antiphospholipid Syndrome/drug therapy , Antirheumatic Agents/pharmacology , Hydroxychloroquine/pharmacology , Trophoblasts/drug effects , Antiphospholipid Syndrome/immunology , Cell Line , Cell Movement/drug effects , Cytokines/genetics , Cytokines/metabolism , Female , Gene Expression Regulation, Developmental/drug effects , Humans , Membrane Proteins/genetics , Membrane Proteins/metabolism , Pregnancy , Pregnancy Trimester, First , Tissue Inhibitor of Metalloproteinase-2/genetics , Tissue Inhibitor of Metalloproteinase-2/metabolism , Trophoblasts/physiologyABSTRACT
Osteoporosis is the most common cause of fragility fractures. Bone remodelling is essential for repairing damaged areas within bone to preserve bone strength and for assisting in mineral homeostases. In young adults, bone remodelling is usually balanced with approximately as much bone replaced as is removed during each remodelling cycle. However, when remodelling becomes accelerated in combination with an imbalance that favours bone resorption over formation, such as during menopause, precipitous losses in bone mass occur. Bone turnover markers (BTMs) measure the rate of bone remodelling allowing for a dynamic assessment of skeletal status and hold promise in identifying those at highest risk of rapid bone loss and subsequent fracture. Further, the use of BTMs to monitor individuals administered osteoporosis therapy is attractive as monitoring anti-fracture efficacy with bone mineral density has significant limitations. This review details remodelling biology, pre-analytical and analytical sources of variability for BTMs, describes the most commonly used resorption and formation markers, and offers some guidelines for their use and interpretation in the laboratory and the clinic.
Subject(s)
Bone Remodeling/physiology , Osteoporosis, Postmenopausal/metabolism , Osteoporosis, Postmenopausal/therapy , Biomarkers/metabolism , Bone Resorption/metabolism , Bone Resorption/physiopathology , Female , Humans , Osteogenesis/physiology , Osteoporosis, Postmenopausal/physiopathologyABSTRACT
The MTG-BT estimates the hydrolysis of triacyl-glycerols by pancreatic lipase, and appears attractive for monitoring exogenous lipase requirements in patients with exocrine pancreatic insufficiency. To assess the test's discrimination capacity and repeatability, 9 CF patients with PERT and 10 healthy children underwent the (13)C-MTG-BT twice, at a 2- to 4-week interval. The test distinguished well between patients with severe exocrine pancreatic insufficiency (SEPI) and healthy subjects. However, within-subject variability for postprandial per thousand(13)C-enrichment and postprandial % dose recovery (PDR) was high in both groups. Therefore, the (13)C-MTG-BT seems useful to distinguish between SEPI and normal exocrine pancreatic function, but requires further development to improve its repeatability.
Subject(s)
Breath Tests/methods , Cystic Fibrosis , Lipase/metabolism , Pancreas/enzymology , Triglycerides , Adolescent , Child , Cystic Fibrosis/enzymology , Cystic Fibrosis/therapy , Female , Humans , Male , Pilot Projects , Reproducibility of Results , Triglycerides/chemistry , Triglycerides/metabolismABSTRACT
The hormone assay laboratory has seen incredible changes over the last 50 years. In this historical review, we describe how the evolution of fundamental concepts in endocrinology and in hormone assay technology have faceted the laboratory as we know it today. The discovery of neurohormones, hormone receptors and the evolution of the concept of free hormones had a very significant impact on our understanding of the mechanisms of hormone action in health and disease and therefore on how physicians currently prescribe endocrine tests. In the analytical field, modern hormone assays rapidly replaced crude colorimetric methods and bioassays. Starting with the pioneering work of Yalow and Berson, hormone assays have gradually evolved through improvements in all aspects of assay design. This is best exemplified by the evolution of thyroid and parathyroid hormone assays. After reviewing some of the limitations of actual hormone immunoassays, we present some reflections on what the future of the hormone laboratory may look like considering all the developments in automation, point-of-care testing, molecular biology and array technologies.
Subject(s)
Endocrinology/methods , Endocrinology/trends , Automation , Immunoassay , Laboratories , Parathyroid Hormone/analysisABSTRACT
CONTEXT: The quantitative evaluation of circulating PTH peaks revealed by PTH assays after HPLC separation constitutes the best way to study the behavior of PTH molecular forms, but it is also impractical. OBJECTIVE: The objective of the study was to investigate the regulation of circulating PTH molecular forms by calcium through the use of PTH fragments/PTH (1-84) ratios derived from PTH assays with different specificities before and after HPLC separation of circulating PTH. DESIGN: CaCl2 and Na citrate were infused in eight volunteers. PTH was measured in serum and HPLC fractions at different calcium concentrations in PTH assays reacting with regions 1-2 (CA), 12-18 (T), and 65-69 (C) of the PTH structure. RESULTS: From hypo- to hypercalcemia, the C/CA ratio had the highest range (1.92 to 9.75; P < 0.001), and the C/T ratio had a higher range (1.69 to 6.11; P < 0.01) than the T/CA ratio (1.15 to 1.86). Human (h) PTH (1-84) represented 32.7 and 4.3% of circulating PTH in hypo- and hypercalcemic HPLC profiles, respectively. These numbers were 5 and 0.9% for amino-terminal (N)-PTH, an amino-terminal form of PTH distinct from hPTH (1-84), 7.3 and 6.8% for non-(1-84) PTH or large C-PTH fragments with a partially preserved N structure, and 54.9 and 88.1% for C-PTH fragments missing a N structure. The HPLC C-PTH fragments to hPTH (1-84) ratio had the most extensive range (1.67 to 20.58). Despite their quantitative differences, all ratios identified identical behavior of PTH fragments relative to PTH (1-84). CONCLUSIONS: PTH assay ratios are an adequate tool to investigate the modulation of PTH molecular forms, even if all PTH assays show some undesirable cross-reactivity with certain circulating forms of PTH.
Subject(s)
Calcium/physiology , Parathyroid Hormone/metabolism , Adult , Algorithms , Calcium/blood , Calcium/pharmacology , Calcium Chloride/pharmacology , Chromatography, High Pressure Liquid , Citrates/pharmacology , Female , Humans , Hypercalcemia/blood , Hypocalcemia/blood , Male , Parathyroid Glands/physiology , Parathyroid Hormone/chemistry , Peptide Fragments/blood , Peptide Fragments/metabolism , Sodium CitrateABSTRACT
OBJECTIVE: Rare patients with severe primary hyperparathyroidism present with large parathyroid tumours, severe hypercalcaemia, very high PTH levels and osteitis fibrosa cystica. Some of these patients display a large amount of C-PTH fragments in circulation and present with a higher C-PTH/I-PTH ratio than seen in less severe cases of primary hyperparathyroidism. We wanted to determine how PTH levels and circulating PTH high-performance liquid chromatography (HPLC) profiles analysed with PTH assays having different epitopes could be affected by medical and surgical treatment in such patients. DESIGN: A 55-year-old man with severe hypercalcaemia (Ca(2+): 2.01 mmol/l), very high PTH levels (CA-PTH 82.1 and T-PTH 72 pmol/l) caused by a large parathyroid tumour (7.35 g) and accompanied by significant bone involvement (alkaline phosphatase of 185 UI/l and subperiostal bone resorption of hands) was referred to us. Blood was obtained at various time points during his medical treatment, before and after surgery, to measure parameters of calcium and phosphorus metabolism, and of bone turnover. HPLC separations of circulating PTH molecular forms were performed and analysed with PTH assays having 1-4 (CA), 12-18 (T), 26-32 (E) and 65-84 (C) epitopes. RESULTS: Before surgery, serum Ca2+ was nearly normalized with hydratation, intravenous (IV) pamidronate and oral vitamin D administration. Despite a decrease in Ca2+ to 1.31 mmol/l, CA-PTH and T-PTH levels decreased by half in relation to a threefold increase in basal 1,25-dihydroxyvitamin D [1,25(OH)2D] level (94 to 337 pmol/l). After this initial positive response, hypercalcaemia and elevated CA- and T-PTH levels recurred even if 1,25(OH)2D levels remained elevated. The tumour was removed surgically and proved to be poorly differentiated with nuclear atypia and mitosis. After surgery, the Ca2+ level and PTH secretion normalized. The higher CA-PTH level relative to the T-PTH level observed before surgery in this patient was related to the oversecretion of an amino-terminal (N) form of PTH recognized by PTH assays with (1-4) or (26-32) epitopes but not by the T-PTH assay with a (12-18) epitope. This molecular form represented 50% of CA-PTH measured in this patient, but only 7% in less severe cases of primary hyperparathyroidism. It was unaffected by medical therapy and disappeared after surgery. CONCLUSION: The relationship between the overexpression of this N-PTH molecular form and severe primary hyperparathyroidism remains unclear. Further studies will be required in these rare patients to see whether N-PTH is a marker of less well differentiated parathyroid tumours and/or relates to the overproduction of C-PTH fragments in the presence of severe hypercalcaemia.
Subject(s)
Adenoma/blood , Hyperparathyroidism/blood , Mediastinal Neoplasms/blood , Parathyroid Hormone/blood , Adenoma/drug therapy , Adenoma/surgery , Antineoplastic Agents/therapeutic use , Calcium/blood , Chromatography, High Pressure Liquid/methods , Diphosphonates/therapeutic use , Fluid Therapy , Humans , Hyperparathyroidism/drug therapy , Hyperparathyroidism/surgery , Male , Mediastinal Neoplasms/drug therapy , Mediastinal Neoplasms/surgery , Middle Aged , Pamidronate , Parathyroid Hormone/chemistry , Vitamin D/therapeutic useABSTRACT
BACKGROUND: Non-(1-84) parathyroid hormone (PTH) fragments are large C-terminal fragments of PTH with a partially preserved N-terminal structure. They differ from other C-terminal PTH fragments, which do not have an N-terminal structure and do not react in intact PTH assays. We aimed to identify the minimal N-terminal structure common to all non-(1-84) PTH fragments. METHODS: Sera obtained from six healthy individuals and six patients with primary hyperparathyroidism, and six serum pools from dialysis patients with different PTH concentrations were fractionated by HPLC and analyzed by four different PTH assays. Each assay was characterized by saturation analysis of its detection antibody and capacity to react with different PTH fragments. Human PTH(1-84) [hPTH(1-84)] calibrators were normalized to an in-house hPTH(1-84) calibrator. RESULTS: The cyclase-activating PTH (CA-PTH) assay had an early (1, 2,) epitope and reacted only with hPTH(1-84). The other assays had epitopes in region (13-34). Total and intact PTH assays had epitopes proximal to position 18 and reacted equally well with hPTH(1-84) and hPTH(7-84), and the Elecsys PTH assay had an epitope distal to position 19, being saturable by hPTH(18-48) and also reacting with [Tyr(34)]hPTH(19-84). The HPLC profiles obtained with these assays showed that non-(1-84) PTH fragments did not react in the CA-PTH assay, as expected. The amount of non-(1-84) PTH detected by the other three assays was similar when the assay results were normalized to a common calibrator. CONCLUSIONS: The results suggest that the amount of non-(1-84) PTH detected by epitopes proximal or distal to position 19 of the PTH structure is identical, indicating a common minimum structure starting before position 19. This in turn points to a probable high-affinity interaction with the C-PTH receptor, as observed previously with [Tyr(34)]hPTH(19-84) in various cell lines and in mouse osteocytes with PTH/PTHrP type I receptor ablation.
Subject(s)
Parathyroid Hormone/chemistry , Peptide Fragments/chemistry , Calibration , Epitopes , Humans , Hyperparathyroidism/blood , Immunoassay , Parathyroid Hormone/blood , Parathyroid Hormone/immunology , Peptide Fragments/blood , Peptide Fragments/immunologyABSTRACT
UNLABELLED: Several pharmacological interventions reduce perioperative stress hormone release during surgery under general anesthesia. Listening to music and therapeutic suggestions were also studied, but mostly in awake patients, and these have a positive effect on postoperative recovery and the need for analgesia. In this study, we evaluated the effect of listening to music under general anesthesia on the neurohormonal response to surgical stress as measured by epinephrine, norepinephrine, cortisol, and adrenocorticotropic hormone (ACTH) blood levels. Thirty female patients scheduled for abdominal gynecological procedures were enrolled and randomly divided into two groups: group NM (no music) and group M (music). In group M, music was played from after the induction of anesthesia until the end of surgery. In the NM group, the patients wore the headphones but no music was played. We established three sample times for hormonal dosage during the procedure and one in the recovery room. Hemodynamic data were recorded at all times, and postoperative consumption of morphine in the first 24 h was noted. There was no group difference at any sample time or in the postoperative period in terms of mean arterial blood pressure, heart rate, isoflurane end-tidal concentration, time of the day at which the surgery was performed, bispectral index (BIS) value, doses of fentanyl, or consumption of postoperative morphine. There was no difference between the two groups with regard to plasmatic levels of norepinephrine, epinephrine, cortisol, or ACTH at any sample time, although the blood level of these hormones significantly increased in each group with surgical stimulation. In conclusion, we could not demonstrate a significant effect of intraoperative music on surgical stress when used under general anesthesia. IMPLICATIONS: Listening to music under general anesthesia did not reduce perioperative stress hormone release or opioid consumption in patients undergoing gynecological surgery.