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Rationale & Objective Management of chronic kidney disease mineral and bone disorder requires parathyroid hormone (PTH) concentrations. “Biointact” PTH immunoassays detect “whole” PTH (wPTH), whereas “intact” immunoassays measure PTH plus PTH fragments (iPTH). We aimed to determine whether longitudinal changes in PTH concentrations can be evaluated using biointact and intact immunoassays alike. Study Design Open noninterventional longitudinal cohort study. Setting & Participants PTH concentrations were measured quarterly up to 5 times in 102 hemodialysis patients. Predictors & Tests Compared Age, sex, phosphate levels, and others as clinical predictors for PTH trend. Tests compared were iPTH immunoassays from Siemens and Roche and wPTH immunoassays from Roche and DiaSorin. Outcomes PTH concentration trend; regression equations; test bias. Analytical Approach Predictive regression-to-the-mean model for PTH slope; Bland-Altman plots, Passing-Bablok regression, and reference change values for test comparisons. Results wPTH concentrations were similar with both immunoassays (wPTH-Roche = 11.7 + 0.97 × wPTH-DiaSorin, r = 0.99; mean ± 1.96 SD bias, 8.2 ± 43.3 pg/mL [17.5% ± 40.9%], by Bland-Altman plots). iPTH-Siemens concentrations were higher than iPTH-Roche concentrations (iPTH-Siemens = −5.4 + 1.33 × iPTH-Roche, r = 0.99; mean ± 1.96 SD bias, 84.0 ± 180.2 pg/mL [21.1% ± 29.8%], by Bland-Altman plots). iPTH-Roche and iPTH-Siemens concentrations were 2- and 2.5-fold higher than wPTH concentrations, respectively. Full agreement among all 4 immunoassays in detecting both significant and insignificant changes in PTH concentrations, upward or downward from one quarter to the next, was reached in 87% of consecutive measurements. In a predictive model, baseline PTH concentrations > 199 pg/mL (wPTH-Roche), 204 pg/mL (wPTH-DiaSorin), 386 pg/mL (iPTH-Roche), and 417 pg/mL (iPTH-Siemens) correctly predicted declining PTH concentration trend in 62% to 68% of patients, but age, sex, hemodialysis vintage, and calcium and phosphate levels were no significant predictors. Limitations Limited number of immunoassays, only 59 patients attended all quarterly samplings. Conclusions wPTH-Roche and wPTH-DiaSorin concentrations were similar, while iPTH was higher than wPTH concentrations. The iPTH-Siemens immunoassay is either higher calibrated or detects more fragments than iPTH-Roche. However, longitudinal PTH concentration changes largely coincided with all tested immunoassays., Graphical abstract

Introduction: Pentagastrin (Pg) stimulated calcitonin (sCT) was used to enhance accuracy in medullary thyroid cancer (MTC) diagnosis. As it is now unavailable, calcium (Ca) has been recommended as an alternative. The aim of this study was to define gender-specific cut-off values to predict MTC in patients with elevated basal CT (bCT) following Pg-sCT and Ca-sCT stimulation and to compare the time courses of CT release during stimulation. Materials and methods: The stimulation tests were applied in 62 consecutive patients with thyroid nodules. Basal calcitonin was measured by chemiluminescent immunometric assay. All patients underwent thyroidectomy and bilateral central neck dissection. C-cell pathology was confirmed by histological and immunohistochemical evaluation. Results: In 39 (0.63) patients MTC was documented while isolated C-cell hyperplasia (CCH) was identified in 23 (0.37) patients. Medullary thyroid cancer was predicted in males with bCT values > 43 pg/mL or sCT concentrations > 470 pg/mL (Pg-sCT) or > 1500 pg/mL (Ca-sCT), and in females with bCT concentrations > 23 pg/mL or sCT concentrations > 200 pg/mL (Pg-sCT) or > 780 pg/mL (Ca-sCT), respectively. Pg-sCT correctly predicted MTC in 16 (0.66) compared to 13 (0.54) after Ca-sCT in males and in 12 (0.80) compared to 11 (0.73) in females; without statistical significance. In patients with CCH or low tumor burden, there was a tendency of faster CT release after Ca stimulation (CT peak after 3min in > 60%) compared to patients with advanced MTC (CT peak after 3min in < 10%). Conclusions: Using gender-specific cut-off values, Ca could replace Pg to predict MTC with similar diagnostic power.

Increased lipid availability reduces insulin-stimulated glucose disposal in skeletal muscle, which is generally explained by fatty acid–mediated inhibition of insulin signaling. It remains unclear whether lipids also impair transcapillary transport of insulin and glucose, which could become rate controlling for glucose disposal. We hypothesized that lipid-induced insulin resistance is induced by inhibiting myocellular glucose uptake and not by interfering with the delivery of insulin or glucose. We measured changes in interstitial glucose and insulin in skeletal muscle of healthy volunteers during intravenous administration of triglycerides plus heparin or glycerol during physiologic and supraphysiologic hyperinsulinemia, by combining microdialysis with oral glucose tolerance tests and euglycemic-hyperinsulinemic clamps. Lipid infusion reduced insulin-stimulated glucose disposal by ∼70% (P < 0.05) during clamps and dynamic insulin sensitivity by ∼12% (P < 0.05) during oral glucose loading. Dialysate insulin and glucose levels were unchanged or even transiently higher (P < 0.05) during lipid than during glycerol infusion, whereas regional blood flow remained unchanged. These results demonstrate that short-term elevation of free fatty acids (FFAs) induces insulin resistance, which in skeletal muscle occurs primarily at the cellular level, without impairment of local perfusion or transcapillary transport of insulin and glucose. Thus, vascular effects of FFAs are not rate controlling for muscle insulin-stimulated glucose disposal.

Reasonable application of laboratory parameters in prevention, diagnosis, treatment and therapy monitoring of osteoporosis.Physicians from different specialist disciplines (general medicine, geriatrics, gynaecology, urology, internal medicine-especially endocrinology and metabolism, nephrology, laboratory medicine, rheumatology, nuclear medicine, orthopaedics, paediatrics, rehabilitation and physical medicine, radiology, social medicine, transplantation medicine, accident surgery), moreover social insurances, hospitals and self-help groups.Evaluation of aetiology of bone disorders, widening of the therapeutic spectrum for diseases of bone and knowledge on biochemical markers of bone turnover. Improvements in judging the success of therapy and in monitoring the compliance of patients. Research perspectives.Scientific literature and guidelines, consensus meetings. RÉSUMÉ: Basic and specialized laboratory investigations are important in differentiation between primary and secondary osteoporosis for an adequate therapy. Biochemical markers of bone turnover are an additional aid in evaluation of individual fracture risk. These markers identify responders to bone therapy faster than surveillance of bone mineral density, which helps to improve patient's compliance too. Characteristics, preanalytic precautions and applications are presented for selected markers of bone resorption and formation and for parameters regulating bone metabolism.

Primary hyperparathyroidism (PHPT) is accompanied with a reduced bone mineral density (BMD) and an increased risk of fracture. Surgery is the only option for cure. It is hypothesized that in patients with PHPT bone metabolism normalizes after parathyroidectomy (PTX) and that BMD gradually increases. Fifty-two patients with PHPT who underwent surgery were prospectively followed for 1 year. Biochemical analyses were performed at baseline and 1, 4, 7 days; 6 weeks; and 3, 6, and 12 months, and BMD before and one year after surgery. Parathyroid hormone (PTH), calcium, and the bone resorption marker dropped immediately, but transiently after PTX, bone formation decreased more slowly. Osteoprotegerin (OPG) as well as cathepsin K did not show significant changes. BMD of the lumbar spine, but not of the femoral neck, increased significantly within one year after surgery. Moderate correlations existed between the changes of total calcium, ionized calcium, as well as bone-specific alkaline phosphatase and changes of the lumbar BMD. Patients who needed postoperative supplementation with calcium and vitamin D had significantly higher PTH levels. Some gender-specific differences in patients with PHPT were observed. In patients with PHPT, males appear to be more severely affected than females. Within the first year after PTX, bone metabolism normalized, and BMD of the lumbar spine increased. Patients who needed a supplementation with calcium and vitamin D after PTX preoperatively had higher serum levels of PTH.

Eur J Clin Invest 2012; 42 (6): 649–656 Abstract Background Recent studies show associations between inorganic phosphate and risk of heart failure in the general population as well as between fibroblast growth factor 23 (FGF-23) and outcome in coronary heart disease. This study was carried out to assess whether circulating levels of inorganic phosphate and FGF-23, a new central hormone in mineral bone metabolism, predict outcome in systolic heart failure. Materials and methods Ninety-nine consecutive outpatients with systolic heart failure were enrolled. Mean (SD) age was 61 years (11), mean left ventricular ejection fraction (LVEF) was 33% (10), 82 patients were men, median estimated creatinine clearance was 83 mL/min (Q1–Q3 58–106), median NTproBNP level was 803 pg/mL (Q1–Q3 404–2757), median inorganic phosphate was 1·12 mM (Q1–Q3 1·02–1·22), median FGF-23 was 39·02 pg/mL (Q1–Q3 32·45–55·86) and median follow-up was 35 months. Associations between inorganic phosphate, FGF-23 and endpoints were assessed using Cox regression analyses. Results Inorganic phosphate and FGF-23 levels were significantly higher (P

Radiofrequency ablation of atrial fibrillation (AF) creates left atrial (LA) tissue damage with a subsequent healing process. We sought to prospectively assess the time course of biomarkers of tissue repair after ablation and to evaluate their association with clinical variables.30 consecutive patients (57.9 ± 1.7 yrs, 63% males) with paroxysmal AF underwent a CARTO-guided LA circumferential ablation, Lasso-guided segmental pulmonary vein isolation and ablation of complex fractionated atrial electrograms. Matrix metalloproteinase-9 (MMP-9) and transforming growth factor-β1 (TGF-β1), both key regulators of tissue repair, and the aminoterminal propeptide of type III procollagen (PIIINP), reflecting collagen synthesis, were determined in blood samples before and 6h, 1, 2, 7, 30, 90 and 180 days post-ablation.All markers showed a significant ablation-induced up-regulation (MMP-9: 1.8 ± 0.1-fold, TGF-β1: 2.4 ± 0.4-fold, PIIINP: 1.3 ± 0.1-fold). MMP-9 was significantly up-regulated until day 90, TGF-β1 only on day 2. PIIINP increased from day 2 to 7. The area under the curve (AUC) of MMP-9 and TGF-β1 correlated with the ablation-induced reduction of LA volume (both p0.05). The AUC of MMP-9 was additionally associated with the amount of radiofrequency energy delivered during ablation (p0.05). At 12 months of follow-up 57% of patients were free of AF off antiarrhythmic drugs. The AUC of PIIINP independently predicted recurrent AF (p0.05).Markers of healing showed a significant up-regulation after AF ablation detectable for up to 90 days. A more pronounced up-regulation of MMP-9 or TGF-β1 is associated with a greater reduction of LA size. High PIIINP levels after ablation predict a poor ablation outcome.

Introduction A controlled intervention trial was conducted to assess the impact of spinach consumption on DNA stability in lymphocytes and on health-related biochemical parameters. Methods The participants (n = 8) consumed homogenised spinach (225 g/day/person) over a period of 16 days. DNA migration was monitored in single cell gel electrophoresis—comet assays under standard conditions, which reflect single- and double-strand breaks, after treatment of nuclei with lesion-specific enzymes (formamidopyrimidine glycosylase, FPG and endonuclease III, ENDO III) and after treatment of intact cells with H2O2 before, during and after intervention. Results While no reduction in DNA damage was observed under standard conditions after different time intervals of spinach intake, other endpoints, namely ROS sensitivity and DNA migration attributable to the formation of oxidatively damaged DNA bases (i.e. pyrimidinesENDO III-sensitive sites and purines-FPG sensitive sites) were reduced 6 h after consumption of the first portion and after 11 days of continuous consumption. In the case of ENDO III-sensitive sites, also after 16 days, a decrease in comet formation was observed. At the end of a 40 days washout period, the DNA stability parameters were not significantly different from the background values. Other biochemical parameters which were significantly altered by spinach intake were the folate (?27%) and homocysteine (-16%) concentrations in blood, and it was found in an earlier human study that folate may prevent oxidative damage to DNA bases. Conclusions Taken together, our results show that moderate consumption of spinach causes protection against oxidative DNA damage in humans and that this phenomenon is paralleled by alterations of health-related biochemical parameters.

Systemic infection and inflammation in men are associated with bone loss. Rodent studies have elucidated the pathways mediating the effects of bacterial lipopolysaccharide (LPS), activated immune cells and hormones on bone. Here we investigate the changes in biochemical parameters of bone turnover following human endotoxemia, an experimental model of self-limiting systemic infection and inflammation. Ten healthy men received in a randomised, placebo-controlled, cross-over trial once placebo and once 2 ng/kg Escherichia coli endotoxin (LPS). During the following 6 h we monitored parathyoid hormone (PTH) and osteopontin (OPN), a multifunctional protein related to bone pathophysiology, as well as biochemical markers of bone turnover: C-terminal telopeptide of type I collagen (CTX), N-terminal propeptide of type I collagen (P1NP) and osteocalcin (OC). In LPS sessions there was a transient fall in PTH at 3 h (p=0.009) and a nearly two-fold increase in OPN levels after 6 h (LPS: 155+/-19 pg/ml; placebo: 85+/-13 pg/ml, p

Susceptibility to osteoporosis seems to be influenced genetically. Previous studies on the effects of genetic polymorphisms on bone mineral density (BMD) showed controversial results. Vitamin K hydrochinon is an important cofactor for gamma carboxylation of osteocalcin. The reduction of vitamin K to vitamin K hydrochinon depends on the vitamin K epoxide reductase complex subunit 1 (VKORC1). We evaluated the impact of polymorphisms in VKORC1 on BMD and fractures. In this single-center study, 184 individuals (141 female subjects and 43 male subjects, mean age: 63.2 +/- 14.3 years) were recruited. In all, 149 of 184 could be genotyped by allele-specific polymerase chain reaction (PCR) for the VKORC1 variants 3673G>A or 9041G>A. The genotypes were correlated with clinical parameters. Vitamin K(1) concentrations were determined by high-performance liquid chromatography (HPLC); carboxylated (GlaOC) and undercarboxylated osteocalcin (GluOC) was determined by enzyme-linked immunosorbent assays (ELISAs). The 9041 GG and GA genotypes were significantly more frequent in patients with low BMD (P = 0.012). Thus, carriers of at least 1 G-allele seem to have a higher risk for low BMD. No statistically significant association was found for the 3673 G>A variant and BMD. GluOC concentrations were higher in patients who carried a 3673 GA and GG genotypes (P = 0.07). For both variants, no association with fractures could be observed. In our cohort, a genetic variation in the 3'-region of the VKORC1 gene (9041 AG and GG) was associated significantly with low BMD. This finding suggests that VKORC1 may play a role in osteoporosis. The results of our pilot study should be confirmed as our findings may be important for treatment decisions.

Serotonin modulates the activity of the hypothalamic-pituitary-adrenal (HPA) axis particularly via the serotonin-1A receptor (5-HT(1A)). Therefore, the rationale of this positron emission tomography (PET) study was to investigate the influence of the 5-HT(1A) receptor distribution in the human brain on plasma levels of dehydroepiandrosterone sulfate (DHEAS) and cortisol in vivo. Eighteen healthy female were measured with PET and the selective 5-HT(1A) receptor radioligand [carbonyl-(11)C]WAY-100635. Nine a priori defined brain regions (hypothalamus, orbitofrontal cortex, amygdala, hippocampus, anterior and posterior cingulate cortices, dorsal raphe nucleus, retrosplenial cortex, and insula) and the cerebellum (reference region) were delineated on coregistered MR images. DHEAS and cortisol plasma levels were collected by blood sampling in the morning of the PET day. Linear regression analysis of DHEAS plasma level as dependent variable and hypothalamic 5-HT(1A) receptor binding potential (BP) as independent variable showed a highly significant association (r=.691, p=.002). The hypothalamic 5-HT(1A) BP predicted 47.7% of the variability in DHEAS plasma levels. Regressions were borderline significant (p.01, Bonferroni corrected threshold.0056) between 5-HT(1A) BP in the anterior cingulate and orbitofrontal cortices and free cortisol levels. No significant associations between DHEAS or cortisol and the 5-HT(1A) receptor BP in other investigated brain regions were found. In conclusion, the serotonergic system may influence the DHEAS plasma level by modulating CRH and ACTH release via hypothalamic 5-HT(1A) receptors as reported for cortisol before. As disturbances of the HPA axis as well as changes of the 5-HT(1A) receptor distribution have been reported in affective disorders, future studies should focus on these interactions.

Two major pathways of human myeloid dendritic cell (DC) subset differentiation have previously been delineated. Langerhans cells (LCs) reside in epithelia in the steady state, whereas monocytes can provide dendritic cells (DCs) on demand in response to inflammatory signals. Both DC subset pathways arise from shared CD14+ monocyte precursors, which in turn develop from myeloid committed progenitor cells. However, the underlying hematopoietic mechanisms still remain poorly defined. Here, we demonstrate that the vitamin D3 receptor (VDR) is induced by transforming growth factor β1 during LC lineage commitment and exerts a positive role during LC generation. In contrast, VDR is repressed during interleukin-4 (IL-4)–dependent monocyte-derived DC (moDC) differentiation. We identified GATA-1 as a repressor of VDR. GATA-1 is induced by IL-4 in moDCs. Forced inducible expression of GATA-1 mimics IL-4 in redirecting moDC differentiation and vice versa, GATA-1 knockdown arrests moDC differentiation at the monocyte stage. Moreover, ectopic GATA-1 expression stabilizes the moDC phenotype under monocyte-promoting conditions in the presence of vitamin D3 (VD3). In summary, human myeloid DC subset differentiation is inversely regulated by GATA-1 and VDR. GATA-1 mediates the repression of VDR and enables IL-4–dependent moDC differentiation. Conversely, VDR is induced downstream of transforming growth factor β1 and is functionally involved in promoting LC differentiation.

Zusammenfassung Osteoporose wird von der WHO zu den ökonomisch bedeutsamsten Erkrankungen des 21. Jahrhunderts gezählt. Abgesehen von Anamnese, klinischer Untersuchung und bildgebenden Verfahren sind Laboruntersuchungen wichtige Werkzeuge in der Diagnose, Therapieüberwachung und Verlaufskontrolle der Osteoporose. Man unterscheidet Basis-Laboruntersuchungen von weiterführenden Laboruntersuchungen. Das Basislabor dient zur Differentialdiagnose zwischen primären und sekundären Formen der Osteoporose. Ursachen der sekundären Formen der Osteoporose müssen unter anderem durch weiterführende Untersuchungen abgeklärt werden. Spezielle Biomarker des Knochenstoffwechsels werden hauptsächlich zur Therapieüberwachung und Verlaufsbeurteilung der Osteoporose genutzt.

‘Calcitonin screening’ is not accepted as the standard of care in daily practice. The clinical and surgical consequences of ‘calcitonin screening’ in a series of patients with mildly elevated basal calcitonin and pentagastrin stimulated calcitonin levels are presented. 260 patients with elevated basal (>10 pg/ml) and stimulated calcitonin levels (>100 pg/ml) were enrolled in this prospective study. None of the patients was member of a known medullary thyroid carcinoma family. Thyroidectomy and bilateral central and lateral neck dissections were performed. Testing for the presence of germ-line mutations was performed in all patients. Histological and immunohistochemical findings were compared with basal and stimulated calcitonin levels. All patients were subsequently followed biochemically. C-cell hyperplasia (CCH) was found in 126 (49%) and medullary thyroid cancer was found in 134 (51%) patients. RET proto-oncogen mutations were documented in 22 (8%) patients (medullary thyroid cancer:18, CCH:4). In 56 (46%) of 122 patients, sporadic CCH was classified neoplastic (‘carcinoma in situ’). Of 97 (72%; 10 with hereditary medullary thyroid cancer) had pT1 (International Union against Cancer recommendations 2002) and 33 (25%) had pT2 or pT3 and 4 (3%) pT4 tumors. Of 39 (29.1%) had lymph node metastases. 106 (79.1%; 15 (38.5%) with lymph node metastases) patients were cured. Evaluation of basal and stimulated calcitonin levels enables the prediction of medullary thyroid cancer. All patients with basal calcitonin >64 pg/ml and stimulated calcitonin >560 pg/ml have medullary thyroid cancer. Medullary thyroid cancer was documented in 20% of patients with basal calcitonin >10 pg/ml but 100 pg/ml but

OBJECTIVES High-grade prostate cancer is associated with low serum testosterone levels, which generally recover after radical prostatectomy. The cause of this low testosterone level is unclear, and it has been hypothesized that cancer cells produce a factor that disturbs the pituitary-gonadal axis. Inhibin is a hormone that has a negative feedback effect on this axis. The aim of this study was to investigate the role of serum inhibin in patients with prostate cancer. METHODS The serum hormone levels of the pituitary-gonadal axis, including inhibin levels, in patients with prostate cancer were compared with those in patients with benign prostatic hyperplasia. Testosterone levels of less than 3 ng/mL were classified as hypogonadal. Prostate cancer was classified according to Gleason score as high grade (Gleason score 7 to 10) or low grade (Gleason score 2 to 6). RESULTS A total of 196 men (126 with prostate cancer and 70 with benign prostatic hyperplasia) were entered into the study. The serum inhibin levels did not differ significantly between the patients with benign prostatic hyperplasia and those with prostate cancer (150.0 versus 131.75 pg/mL, P = 0.062), between men with hypogonadal and eugonadal disease (143.0 versus 146.5 pg/mL, P = 0.573), or between those with low-grade and high-grade cancer (151.5 versus 146.0 pg/mL, P = 0.830). Men with high-grade cancer had lower levels of serum testosterone than did those with low-grade cancer (3.49 versus 4.09 ng/mL, P = 0.056). CONCLUSIONS The results of our study have shown that although high-grade prostate cancer is associated with low serum testosterone levels, inhibin does not appear to be the cause of this phenomenon.

Aims Chronic heart failure (CHF) is frequently associated with a decreased haemoglobin level, whereas the mechanism remains largely unknown. Methods and results One hundred consecutive CHF patients without anaemia or renal dysfunction based on non-cardiac reasons were enrolled. We explored determinants of anaemia (as iron parameters, erythropoietin, hepcidin and kidney function) including red cell volume (RCV) (by a 51 Cr assay) as well as related markers and plasma volume. The influence of each factor on haemoglobin concentrations was determined in a multiple regression model. Mean haemoglobin concentrations were 11.7 +/- 0.8 mg/dL in anaemic CHF patients and 14.4 +/- 1.2 mg/dL in non-anaemic patients. Corrected reticulocytes were lower in anaemic patients (35.1 +/- 15.7 vs. 50.3 +/- 19.2 G/L, P = 0.001), but the RCV was not reduced (1659.3 +/- 517.6 vs. 1826.4 +/- 641.3 mL, P = 0.194). We found that plasma volumes were significantly higher in anaemic CHF patients (70.0 +/- 2.4 vs. 65.0 +/- 4.0%, P0.001). Plasma volume was the best predictor of haemoglobin concentrations in the regression model applied (B = -0.651, P0.001, R(2) = 0.769). Conclusion Haemodilution appears to be the most potent factor for the development of low haemoglobin levels in patients with CHF. Our data support an additional independent, but minor influence of iron deficiency on haemoglobin concentrations in CHF patients.

Summary Heart transplantation (HTX) is associated with a reduction in bone mineral density (BMD). Different markers of bone metabolism have been used, and the applied immunosuppressive regimens have also changed over time. This study was performed to re-investigate bone metabolism in HTX recipients. Twenty-five HTX recipients were compared with 25 HTX candidates in respect of biochemical parameters of bone metabolism, BMD, and the frequency of fractures for 1 year. Osteopenia or osteoporosis was observed in approximately two-thirds of the HTX recipients. Nevertheless, only three (12%) HTX recipients developed a vertebral fracture within 1 year after transplantation; no peripheral fractures occurred. Compared with HTX candidates, HTX recipients had lower serum levels of osteocalcin, and higher serum levels of cross-linked-N-telopeptide of type I collagen (NTX). In HTX recipients, osteocalcin initially reached a nadir, increased during the first 3 months, and decreased thereafter. Bone-specific alkaline phosphatase initially increased and then decreased. Serum levels of NTX and parathyroid hormone remained high throughout the year. Despite a high bone turnover, an unexpectedly low rate of vertebral fractures was registered. Nevertheless, each fragility fracture is a serious complication and we need to take steps to prevent this complication.

Purpose: We did a controlled study to assess adverse psychological reactions (APR) associated with high-dose glucocorticoid therapy and tried to detect somatic correlates for the observed reactions. Patients and Methods: Our study included 37 patients with acute lymphoblastic leukemia (ALL) and 11 patients with Morbus Hodgkin (MH) disease, who were treated with high-dose glucocorticoid therapy, and 26 control patients with other types of malignancies. APRs were assessed with a standardized measure via parent-report. Patients with ALL and MH were further analyzed for signs of neuronal cell death in the cerebrospinal fluid, polymorphisms of the glucocorticoid receptor gene, as well as cortisol, adrenocorticorticotropic hormone, and dehydroepiandrosterone sulfate blood levels. Results: Fifty-four percent of ALL, 36% of MH, and 23% of control patients developed APR in the first few weeks of therapy. Approximately 3.5 months later, the majority of patients with ALL showed no APR, similar to control patients. Patients demonstrating a higher, nonsuppressible secretion of cortisol and/or adrenocorticorticotropic hormone during glucocorticoid therapy were found to be more likely to develop APR. No sign of neuronal cell destruction and no correlation of APR with specific glucocorticoid receptor polymorphisms were found. Conclusion: Our results suggest that the development of APR due to glucocorticoid therapy is measurable and correlates with hormonal reaction patterns.

Background The decrease of calcitonin levels after curative operation in patients with medullary thyroid cancer is characterized by individual variation; therefore, intraoperative calcitonin measurements to evaluate the completeness of the resection seem to not be feasible. The aim of this study was to evaluate whether an intraoperative pentagastrin test after thyroidectomy and central neck dissection is useful to predict lymph node involvement of the lateral neck. Methods A group of 30 consecutive patients underwent primary surgery. After thyroidectomy and dissection of the central lymph node compartment, an intraoperative pentagastrin test was performed. Biochemical and histologic data were compared retrospectively. Results Of the group, 20 patients (67%) showed no, or only central neck lymph node, involvement and no increase in calcitonin after intraoperative stimulation. Lymph node involvement was documented histologically in the lateral neck of 10 patients (33%), and 8 patients showed an increase of calcitonin as an indication of lymph node involvement. In two patients, each with 1 single micrometastasis in the lateral neck, the intraoperative pentagastrin test was negative. Conclusions Intraoperative calcitonin monitoring after pentagastrin stimulation seems promising in predicting lymph node involvement of the lateral neck to aid selection of patients for lateral lymph node dissection. The development of a highly sensitive, quick calcitonin assay is imperative.

OBJECTIVE—In response to hyperglycemia, β-cells release insulin and C-peptide, as well as islet amyloid pancreatic polypeptide, which is involved in glucose homeostasis. After successful pancreas-kidney transplantation (PKT), type 1 diabetic patients may revert to a nondiabetic metabolism without exogenous insulin therapy and re-secrete all β-cell hormones. RESEARCH DESIGN AND METHODS—Using mathematical models, we investigated hormone (amylin, insulin, C-peptide) and metabolite (glucose, free fatty acids) kinetics, β-cell sensitivity to glucose, and oral glucose insulin sensitivity index (OGIS) in 11 nondiabetic type 1 diabetic patients after PKT (BMI 25 ± 1 kg/m2, 47 ± 2 years of age, 4 women/7 men, glucocorticoid-free), 6 matching nondiabetic patients after kidney transplantation (25 ± 1 kg/m2, 50 ± 5 years, 3 women/3 men, on glucocorticoids), and 9 matching nondiabetic control subjects (24 ± 1 kg/m2, 47 ± 2 years, 4 women/5 men) during a 3-h 75-g oral glucose tolerance test (OGTT). RESULTS—PKT patients had higher fasting amylin (19 ± 3 vs. control subjects: 7 ± 1 pmol/l) and insulin (20 ± 2 vs. control subjects: 10 ± 1 μU/ml; each P < 0.01) levels. Kidney transplant subjects showed increased OGTT plasma insulin at 90 min and C-peptide levels (each P < 0.05). In PKT patients, plasma glucose from 90 to 150 min was 9–31% higher (P < 0.05 vs. control subjects). Amylin clearance was comparable in all groups. Amylin’s plasma concentrations and area under the concentration curve were up to twofold higher in PKT patients during OGTT (P < 0.05). OGIS was not significantly different between groups. β-Cell sensitivity to glucose was reduced in PKT patients (−64%, P < 0.009). Fasting plasma amylin was inversely associated with β-cell sensitivity to glucose (r = −0.543, P < 0.004). CONCLUSIONS—After successful PKT, type 1 diabetic patients with nondiabetic glycemia exhibit increased fasting and post–glucose load plasma amylin, which appears to be linked to impaired β-cell function. Thus, higher amylin release in proportion to insulin might also reflect impaired β-cell function in type 1 diabetic patients after PKT.

Primary hyperparathyroidism (PHP; serum calcium 2.75 mmol/L, PTH 226 pg/ml) had been the first clinical manifestation of MEN-2A in a female patient (aged 55 years) with a mutation (Y791F, TAT--TTT) in exon 13 of the RET proto-oncogene. The patient has a pentagastrin-induced rise in serum calcitonin (up to 57 pg/ml) considered normal for noncarriers but abnormal in family members of MEN-2 patients. This is the first case of MEN-2 due to this specific mutation with primary hyperparathyroidism as the first manifestation of the disease. In addition, the patient harbored, within the Menin gene, a polymorphism (D418D) reportedly associated with sporadic primary hyperparathyroidism. This case report indicates that molecular biological tests in MEN- 2 may only suggest a certain phenotype but cannot predict it with certainty. It may also suggest that genetic screening for MEN-2 may be advisable in patients with primary hyperparathyroidism and a borderline-high pentagastrin stimulation test, even in the absence of a positive family history.

To identify patients with medullary thyroid carcinoma (MTC) at a potentially curable stage of the disease, serum concentrations of calcitonin (hCT) were determined in 14,000 patients (including 10,158 patients with thyroid nodules) referred to a thyroid outpatient clinic. Excluding patients in whom elevated basal hCT concentrations had already been known at the time of their referral, 507 patients with thyroid nodules presented basal concentrations of hCT of more than 10 pg/ml. Following stimulation by IV pentagastrin (0.5 microg/kg BW), hCT concentrations of more than 100 pg/ml were seen in 103 patients. This group included 32 new cases of MTC (29 patients with sporadic MTC and 3 new index cases of the familial form) and 43 patients with C cell hyperplasia (CCH). Among the 3,843 patients without thyroid nodules, 2 were found to harbor sporadic MTC while 4 had CCH. As compared to 1.1 cases of MTC per 1,000 patients with nodular thyroid diseases diagnosed in our institution before hCT screening was begun, 3.2 cases of MTC per 1,000 patients were identified when hCT was determined in all patients with thyroid nodules. The determination of hCT in all patients with thyroid nodular disease facilitates the timely diagnosis of MTC, thus providing the chance of curative surgery.

Summary Anderson-Fabry disease is a glycosphingolipid storage disorder with an X-linked recessive inheritance. The α-galactosidase A deficiency leads to a progressive accumulation of globotriaosylceramide in the endothelium and tissue cells of various organs. The kidney, heart and brain are predominantly affected. Reports on endocrine function and fertility rates in patients with Anderson-Fabry disease are sparse. In the present study, we assessed ovarian, testicular and adrenal function in a cohort of patients with Anderson-Fabry disease. Plasma follicle-stimulating hormone, luteinizing hormone, prolactin, estradiol, testosterone, sex hormone-binding globulin, somatotropin, insulin-like growth factor-I and serum cortisol were measured in 13 patients (six female and seven male), currently observed in an outpatient clinic. The profile revealed an undisturbed hormonal function and a normal fertility rate in both male and female Anderson-Fabry patients when compared with the corresponding Austrian population.

Hemodialysis patients are prone to deficiency of vitamin C, which constitutes the most abundant nonenzymatic antioxidant in blood. Because antioxidants are involved in the pathogenesis of atherosclerosis, the authors examined the association of total vitamin C plasma level with cardiovascular outcomes in such patients. One hundred thirty-eight consecutive maintenance hemodialysis patients (median age 61 yr, 90 males) were enrolled in a single-center study. At baseline, routine laboratory parameters were recorded, and predialysis total vitamin C plasma levels were measured by high-pressure liquid chromatography. Patients were prospectively followed-up for the occurrence of a primary composite endpoint consisting of fatal and nonfatal major adverse cardiovascular events (MACE) and for all-cause and cardiovascular mortality. MACE occurred in 35 patients (25%) over a period of median 30 mo, and 42 patients (30%) died [29 cardiovascular deaths (21% of total)]. Using Cox proportional hazards modeling, adjusted hazard ratios for the occurrence of MACE were 3.90 (95% confidence interval [CI]: 1.42 to 10.67; P = 0.008) and 3.03 (95% CI: 1.03 to 8.92; P = 0.044) for patients in the lower (32 micromol/L) and middle (32 to 60 micromol/L) tertile of total vitamin C levels, compared with patients in the upper tertile (60 micromol/L). Hazard ratios for cardiovascular death were 3.79 (95% CI: 1.23 to 11.66; P = 0.020) and 2.89 (95% CI: 0.89 to 9.37; P = 0.076). Total vitamin C levels were not independently associated with all-cause mortality. This study concludes that low total vitamin C plasma levels predict adverse cardiovascular outcomes among maintenance hemodialysis patients. Future studies should address the potential protective effect of an adequate vitamin C supplementation.

Contradictory reports on the value of intraoperative quick parathyroid hormone (PTH) monitoring in renal hyperparathyroidism have been published.Thirty-five consecutive patients underwent total parathyroidectomy, central neck dissection, bilateral thymectomy, and immediate autotransplantation. PTH levels were measured by PTH assay at induction of anesthesia (baseline level) and in 5-minute intervals after excision of the last parathyroid gland. Parathyroidectomy was considered "total" in patients with PTH levels10 pg/mL (subgroup 1), "subtotal" between 10 and 65 pg/mL (subgroup 2) and "insufficient" at65 pg/mL (subgroup 3) within the first postoperative week.Fifteen minutes after excision of the last gland, PTH levels dropped to 19.4 +/- 15.7% (subgroup 1), 14.9 +/- 5.9% (subgroup 2), and 18 +/- 6.7% (subgroup 3) from baseline among 22 patients on hemodialysis, to 22.1 +/- 18.7% and 17.5% in 9 patients (subgroups 1 and 2) after successful kidney transplantation, and to 10.7% and 17.5% (subgroup 1) and 12.8% and 31.4% (subgroup 2) in 4 patients with reduced renal function after kidney transplantation.Currently available QPTH assays are not useful to predict insufficient resection of hyperfunctioning parathyroid tissue.

Plasma malondialdehyde (MDA), a reactive product of lipid peroxidation, may be influenced by anti-oxidant therapy. The aim of the present study was to investigate if elevated MDA as induced by increased free fatty acids (FFA) correlates with endothelial function and is affected by high doses of vitamin C.The study design was randomised, placebo-controlled, double blind, 2-way cross over. Plasma MDA concentrations and forearm blood flow (FBF) responses to intra-arterial acetylcholine (ACh) and glyceryl trinitrate were assessed during co-administration of vitamin C or placebo in the presence of increased plasma FFA by Intralipid/heparin infusion in 10 healthy male subjects.The seven-fold rise in plasma FFA was associated with an increase in plasma MDA concentrations (r=0.7, p0.001) and decreased FBF responses to ACh (r=-0.4, p0.01). Co-administration of vitamin C restored the impaired reactivity of FBF to ACh but had no effect on elevated MDA concentrations.Anti-oxidant vitamin C improves lipid-induced impairment of endothelium-dependent vasodilation, but does not alter MDA formation or breakdown.

Background. Intravenous vitamin C supplementation to haemodialysis patients might ameliorate responsiveness to recombinant human erythropoietin (rHuEpo). This study was performed to analyse the relation between vitamin C plasma concentration and response to rHuEpo. Methods. In a cross-sectional, single-centre observational study including all haemodialysis patients, pre-dialysis plasma vitamin C concentrations were measured by high-performance liquid chromatography and response to rHuEpo (haemoglobin concentration/ international units rHuEpo/kg/week) was recorded together with baseline laboratory data. Results. Univariate analysis yielded a significant correlation between vitamin C plasma levels and response to rHuEpo (n ¼ 130, r ¼ 0.25, P ¼ 0.004), which still persisted after adjustment for transferrin saturation, C-reactive protein, malondialdehyde, parathyroid hormone, route of rHuEpo administration, residual renal function and diabetes mellitus (adjusted r ¼ 0.23, P ¼ 0.014). Analysis per quartiles of vitamin C plasma level revealed a significantly lower response to rHuEpo with decreasing vitamin C values (P ¼ 0.026). Conclusions. In unselected haemodialysis patients, vitamin C plasma levels account, at least partially, for the response to rHuEpo. Larger-sized interventional studies are needed to find out whether vitamin C plasma levels may or may not appropriately reflect the potential beneficial effect of vitamin C supplements on rHuEpo responsiveness.

We investigated the bone metabolism of 22 patients (median age 38 years) over 6 years after allogeneic bone marrow transplantation (BMT). Biplanar roentgenograms of the thoracic and lumbar spine were used to diagnose vertebral deformities caused by fractures. The actual bone mineral density (BMD) of the lumbar spine and the femoral neck were measured. Laboratory tests included calcium, phosphate, parathyroid hormone, a marker of bone resorption (beta-crosslaps, CTX), markers of bone formation (osteocalcin, bone-specific alkaline phosphatase), osteoprotegerin (OPG) – an antagonist of the osteoclast differentiation factor RANKL, and sex hormone status. One patient had a vertebral fracture. Seven patients (28%) had osteopenia in the lumbar spine while 12 patients (48%) had osteopenia in the femoral neck. Bone resorption was increased in nine patients (43%) and bone formation was increased in four patients (20%). BMT recipients had significantly increased serum levels of OPG (P=0.029). Three women (75%) and four men (25%) were hypogonadal. The data showed that BMD is reduced and bone metabolism is still disturbed more than 6 years after BMT. The RANKL/osteoprotegerin system appears to play an important role in the pathophysiology of late post transplantation osteoporosis.

Routine measurement of serum calcitonin (CT) has been recently proposed for all patients with neoplastic thyroid disease to detect clinically occult medullary thyroid carcinoma (MTC). Data on the prevalence of elevated CT levels in nonneoplastic thyroid disease or in healthy subjects have not been reported to date. Four hundred and fourteen consecutive patients with suspected thyroid disease and 362 healthy controls underwent thyroid examination with measurement of basal serum CT. Whenever serum CT was 10 pg/ml or more, a pentagastrin (PG) stimulation test was performed. Twenty-eight of 414 patients (6.8%) showed elevated basal serum CT levels, 15 of them with nonneoplastic thyroid disease, and the remaining 13 subjects with neoplastic thyroid disease. Four patients with abnormal PG testing (stimulated CT,or = 100 pg/ml) were identified. Three of them had biochemical and sonographical evidence of thyroiditis. Elevated basal CT levels were significantly more frequent in patients with Hashimoto's thyroiditis (HT; P0.05). One female patient with HT had a 5-mm nodule, which was classified as MTC. None of the 6 out of 362 healthy controls with elevated basal CT (1.7%) presented an abnormal PG test. Our data suggest that basal CT measurements can be of use in the detection/screening of MTC not only in subjects with neoplastic thyroid disorders, but also in patients with immunological evidence of HT. They also confirm earlier reports on the essential value of PG stimulation testing, even when basal plasma CT levels are only modestly elevated, with regard to establishing the diagnosis of MTC or its premalignant associated conditions (micro-MTC and neoplastic C cell hyperplasia).

BACKGROUND: Citrate-related side effects are common adverse reactions during PBPC apheresis. To reduce the incidence of citrate-related reactions, the effect of a continuous calcium-gluconate infusion on the appearance of hypocalcemic symptoms and on the subjective tolerance toward large-volume leukapheresis (LVL) was tested. STUDY DESIGN AND METHODS: A double-blinded, placebo-controlled trial was carried out in 50 patients undergoing standardized LVL at a median ACD-A ratio of 1.99 mg per kg and minute. Patients were randomly assigned to receive a continuous IV infusion of either saline or calcium-gluconate at a dose of 1.8 mmol calcium per hour. Subjective tolerance toward LVL was determined by standardized rating systems. Further, hormonal and electrolyte changes were monitored to assess the effect of continuous calcium infusion on calcium homeostasis. RESULTS: Continuous IV administration of calcium-gluconate throughout LVL reduced the incidence of citrate-related effects by 65 percent. In patients who developed signs of hypocalcemia, the symptoms were weaker, and less medical intervention was needed to resolve clinical symptoms. The subjective tolerance toward LVL was superior in patients receiving calcium support compared to control patients. Continuous calcium infusion attenuated changes in serum phosphorus compared to patients receiving saline. No differences were observed in the variation of serum potassium and serum magnesium between the control group and the treatment group. The administration of calcium was not associated with technical problems related to the apheresis procedure, neither was any effect of calcium support on the total number of CD34+ cells collected observed. CONCLUSION: These results indicate that continuous support of calcium-gluconate during LVL is an effective means of reducing the incidence of citrate-related symptoms and improving subjective tolerance toward LVL, without affecting the technical performance or the number of CD34+ cells collected.

Background Heart transplantation (HTX) is associated with decreased bone mineral density and changes in bone metabolism. We conducted this study to evaluate the pathophysiology of bone metabolism in HTX candidates and recipients. Methods Thirty-six HTX recipients were compared with 36 HTX candidates concerning biochemical parameters of bone metabolism and bone mineral density. Results Osteocalcin, bone-specific alkaline phosphatase, cross-linked-N-telopeptide of type I collagen, estradiol, serum creatinine, and blood urea nitrogen concentrations were significantly higher, whereas the calcium–creatinine ratio, thyrotropin, thyroxine, and bone mineral density were significantly lower in HTX recipients than in HTX candidates. Compared with a control group, HTX candidates had decreased renal function and increased bone resorption, whereas HTX recipients additionally had increased alkaline phosphatase and osteocalcin levels. In HTX recipients, we found positive correlations between creatinine clearance and bone mineral density; daily and cumulative cortisone doses were not associated with bone mineral density. Conclusion In HTX candidates, disturbances in bone metabolism with increased bone resorption may be caused partly by existing low-grade renal insufficiency, regular intake of loop diuretics, and restriction of mobility. In HTX recipients, immunosuppressive therapy—glucocorticoids and cyclosporine—seem to be responsible for changes in bone metabolism.

BACKGROUND Transcapillary insulin transfer is considered a rate-limiting step in insulin action at supraphysiological insulin concentrations. However, it remains unclear whether this concept also applies for physiological conditions. MATERIALS AND METHODS In the present study we set out to characterize transcapillary insulin transfer by measuring insulin concentrations in plasma and interstitial space fluid of skeletal muscle during an oral glucose tolerance test and euglycaemic hyperinsulinaemic clamp conditions, respectively. For this purpose we employed in vivo microdialysis of skeletal muscle in conjunction with an ultrasensitive insulin assay in eight healthy lean male volunteers (aged 25 +/- 1 years). RESULTS Insulin concentrations at baseline were 48 +/- 8 pmol x L(-1) in plasma and 19 +/- 4 pmol x L(-1) in the interstitium (P = 0.002). The mean interstitium to plasma ratio at baseline was 0.48 +/- 0.09 pmol x L(-1). During the oral glucose tolerance test the interstitium to plasma ratio remained unchanged (0.43 +/- 0.12, P = NS vs. baseline), but was significantly reduced during euglycaemic hyperinsulinaemic clamp conditions at steady-state hyperinsulinaemia (0.12 +/- 0.01, P = 0.01 vs. baseline). CONCLUSION In summary there is a substantial transcapillary insulin gradient in healthy human skeletal muscle under baseline and glucose-stimulated conditions. Our findings support the hypothesis of a saturable transcapillary insulin transport representing a partly rate-limiting step for insulin action.

SummaryHigh factor VIII (FVIII) is a risk factor for venous thromboembolism (VTE). The pathomechanism by which high FVIII leads to an increased risk of VTE is unknown. Physical activity and infusion of adrenalin provoke a rise in FVIII, which can be blocked by a nonselective β-blockade. We tested the hypothesis that in patients with a VTE β-blockade decreases FVIII and inhibits coagulation activation.17 male patients with high FVIII (> 170 IU/dL, n = 7) or low FVIII (The mean FVIII level before propranolol was 192 IU/dL and 115 IU/dL in patients with high and low FVIII, respectively. During and 28 days after propranolol, no significant change in FVIII was seen in both groups. Changes in f1.2 and TAT were not detectable in either venous blood or in shed blood.β-receptor blockade did not lower FVIII or inhibit haemostatic system activation in patients with VTE and persistently high FVIII. Administration of propranolol cannot be recommended as secondary thromboprophylaxis in patients with high FVIII.

Influence of mycophenolic acid and tacrolimus on homocysteine metabolism.BackgroundThe effect of mycophenolate mofetil (MMF) on homocysteine (Hcy) metabolism is unknown.MethodsThis in vitro study examined whether mycophenolic acid or tacrolimus influences the formation of Hcy as determined by measuring the total Hcy (tHcy) concentrations in supernatants of human renal proximal tubule epithelial cells. Cells were incubated with and without vitamins (folate, vitamin B6 and B12) in the presence of low or high methionine concentrations at different mycophenolic acid (0, or 5, or 20 μg/mL) or tacrolimus (0, or 10, or 25 ng/mL) concentrations for 24, 48 or 72 hours. The concentration of tHcy in culture supernatants was measured by a fluorescence polarization immunoassay. The effect of MMF on tHcy plasma levels was also examined in 454 kidney graft recipients.ResultsComparisons of tHcy levels in culture supernatants over time by four way ANOVA showed that methionine concentration (P < 0.00001), time (P < 0.00001), vitamins (P = 0.002728), and mycophenolic acid concentration (P = 0.000095) were all significant predictors of tHcy concentrations. This was due to significantly lower tHcy levels with using mycophenolic acid at a high concentration versus control at the 48- and 72-hour time points. By contrast, tacrolimus showed no effect in vitro. Among the kidney graft recipients, male patients on MMF therapy showed lower plasma tHcy concentrations as compared to those on azathioprine (P = 0.03).ConclusionOur study suggests a tHcy lowering effect of MMF in male transplant recipients, which improves the cardiovascular disease risk profile, whereas tacrolimus showed no effect.

Summary: Efficacy data as well as correlations of test results measured by different automated immunoassay analysers are obligatory for organisational and medical decisions on a rational scientific basis. Thus, we compared the serum concentrations of reproductive hormones (lutropin, follitropin, estradiol, progesterone, testosterone and prolactin) measured by automated immunoassay-procedures performed on ARCHITECT (Abbot-Laboratories, USA), Elecsys 2010 (Roche-Diagnostics, Switzerland) and IMMULITE 2000 (Diagnostic Products Corporation, USA). Similarly, concentrations of hormones for the estimation of thyroid function (thyreotropin, thyroxin, free thyroxin, triiodothyronine and free triiodothyronine) were measured by these analysers and in addition by AxSYM (Abbot-Laboratories, USA) and ACS:Centaur (Bayer, Germany). At low hormone concentrations we observed for all investigated immunoassays a low day-to-day precision, which might be clinically relevant especially for testosterone and estradiol measurements in women and children. The different assays for reproduction-hormones generally showed a high correlation, whereby a higher scattering of data around the regression lines was observed in the lower measuring range. However, IMMULITE 2000 measured higher testosterone concentrations than the other methods. Differences between results obtained by diverse lutropin and prolactin assays were apparently due to different test calibrations. Most automated thyroid-hormone assays correlated quite well. Higher levels for free triiodothyronine were, however, measured by Elecsys 2010. Although results from the new generation of automated immunoassay-analysers showed some improvements regarding intermethod comparability, it seems still partly unavoidable to establish method specific reference ranges.

The pyridostigmine (PD)/growth hormone-releasing hormone (GHRH) stimulation test was used to determine growth hormone (GH) secretion in patients with pituitary adenomas prior to (n = 55) and after (n = 72) transsphenoidal adenomectomy, as well as in 98 controls. In controls, maximum concentrations of GH showed a strong negative relationship both with body mass index (BMI) and age. Having calculated the 95% confidence intervals for maximum GH concentrations to be expected for any given age and BMI according to a statistical model, we compared these individually predicted ranges to GH concentrations actually observed in patients with pituitary disease during PD/GHRH stimulation. Preoperatively and postoperatively, a maximum GH concentration below the calculated confidence intervals was seen in 29 of 55 (52%) and in 57 of 72 (79%) of these patients, respectively. In the remaining patients, maximum GH concentrations were in or above the range defined by these confidence intervals. Our results indicate that maximum concentrations of GH during the PD/GHRH test depend to a large extent on the individuals' age and BMI. The results obtained with the PD/GHRH stimulation must, in each individual patient, be compared with a large control group taking into account both age and BMI. In individuals older then 55 years and with a BMI greater than 35 kg/(2), the diagnosis of GH deficiency cannot safely be made, at least not with this test.

Is there a role of cyclosporine A on total homocysteine export from human renal proximal tubular epithelial cells?BackgroundImmunosuppressive therapy may influence homocysteine metabolism in allograft recipients. We examined whether cyclosporine A influences the in vitro formation of homocysteine as determined by the measurement of total homocysteine (tHcy) concentrations in supernatants of human renal proximal tubule epithelial cells (hRPTEC), an important site of homocysteine metabolism.MethodsCells were incubated with and without vitamins in the presence of low or high methionine concentrations at different cyclosporine A concentrations for 24, 48 and 72 hours (N = 7 for each experiment). The concentration of tHcy in culture supernatants was measured by a fluorescence polarization immunoassay. Data were analyzed by four-way ANOVA, three-way ANOVA andt tests.ResultsThe Hcy export from hRPTEC (tHcy in the culture supernatant) was 2.69 μmol/L during standard cell culture conditions at time point 24 hours and increased by 28.3% at 48 hours and by 44.6% at 72 hours. Comparisons of tHcy levels in culture supernatants over time by four way ANOVA showed that cyclosporine A at 200 or 800 ng/mL had no influence on tHcy export from hRPTEC (P = 0.67991). In contrast, the presence of vitamins in the medium (P = 0.000001), in vitro methionine loading (P < 0.000001), and prolonged incubation time (P < 0.000001) were associated with an increase of tHcy export from hRPTEC. Significant interactions in this analysis were “vitamins × methionine” (P = 0.001804), “vitamins × time” (P = 0.001478), “methionine × time” (P < 0.000001), and “vitamins × methionine × time” (P = 0.018128), pointing to a combined effect of vitamins in the presence of high methionine concentrations at the later time points.ConclusionOur study shows that hRPTEC export Hcy into the cell culture medium, an effect that is enhanced by in vitro methionine loading and modulated by the presence of vitamins. Cyclosporine A had no major influence on Hcy export from tubule cells. Therefore, our findings do not support the assumption that cyclosporine A elevates total homocysteine plasma levels in organ transplant patients.

OBJECTIVE: To compare plasma concentrations and cardiovascular effects of epinephrine after application via a conventional endotracheal airway and via the esophageal lumen of a new emergency airway, the esophageal tracheal Combitube. DESIGN: Prospective, randomized study. SETTING: Center for Biomedical Research, University of Vienna. SUBJECTS: Fourteen juvenile swine received either an endotracheal tube (Group A) or a Combitube in esophageal position (Group B). INTERVENTIONS: In Part I of the study, epinephrine was administered during spontaneous beating of the heart; in Part II, epinephrine was administered during cardiopulmonary resuscitation, using a ten-fold higher dosage in Group B, respectively. MEASUREMENTS: Plasma epinephrine levels were measured 1, 2, 3, 5, 7, 10, 15, and 30 mins after application. Systolic arterial blood pressure and cardiac output in Part I, and end-tidal CO2 and coronary perfusion pressure in Part II were recorded. MAIN RESULTS: In Part I, increased levels of plasma epinephrine and systolic arterial pressure were maintained significantly longer in Group B when compared with Group A. In Part II, no significant differences between the groups were found with regard to plasma epinephrine levels and hemodynamic variables. CONCLUSION: Epinephrine applied via the esophageal lumen of the Combitube in a ten-fold higher dosage has similar effects on plasma epinephrine levels and hemodynamic variables compared to endotracheal administration.

Objective: To test the hypothesis that the prevalence of hyperhomocysteinemia is increased in critically ill patients and correlates with disease severity and mortality in these patients. Design: A prospective study. Setting: Three medical intensive care units at the University of Vienna Medical School serving both medical and surgical patients. Patients: All consecutive admissions (n = 56) during a period of 4 wks. A total of 112 age- and gender-matched healthy individuals constituted the control group. Interventions: None. Measurements and Main Results: Blood samples were drawn within 24 hrs after admission for analysis of total homocysteine (tHcy), folate, vitamin B 6 levels, and vitamin B 12 levels as well as to identify the 677C→T polymorphism in the gene coding for the enzyme 5,10-methylenetetrahydrofolate reductase. Acute Physiology and Chronic Health Evaluation III scores at admission and 24 hrs after admission as well as 30-day survival were documented in all patients. Hyperhomocysteinemia was more prevalent in critically ill patients (16.1%; 95% confidence interval, 7.6% to 28.3%) compared with age- and gender-matched healthy individuals (5.4%; 95% confidence interval, 2.0% to 11.3%; chi-square test; p =.022). There was no difference in tHcy plasma concentrations in the first 24 hrs after admission to an intensive care unit between survivors and nonsurvivors. The 5,10-methylenetetrahydrofolate reductase 677C→T polymorphism had no influence on tHcy levels and survival of intensive care unit patients. Conclusions: The prevalence of hyperhomocysteinemia is increased in critically ill patients compared to age- and gender-matched healthy individuals. The clinical significance of this finding remains to be determined.

Objective To compare the antipyretic efficacy of aspirin and acetaminophen (INN, paracetamol) in 30 male volunteers with the use of endotoxin (lipopolysaccharide) to elicit a standardized febrile response. Methods A randomized, double-blind, placebo-controlled trial was conducted in parallel groups. Subjects received an intravenous endotoxin bolus of 4 ng/kg after premedication with either placebo, 1000 mg aspirin, or 1000 mg acetaminophen by mouth. Results Peak body temperatures were 38.5°C ± 0.2°C in the placebo group, 37.6°C ± 0.2°C in the acetaminophen group (P = .001 versus placebo), and 38.6°C ± 0.2°C in the subjects treated with aspirin (P = .001 versus acetaminophen; P = .570 versus placebo) at 4 hours after lipopolysaccharide infusion. Subjective symptom scores for chills and perception of fever were higher in the placebo group than in the acetaminophen group (chills, 2.5 ± 0.3 versus 1.0 ± 0.2, P = .009 and fever, 2.5 ± 0.2 versus 2.0 ± 0.2, P = .021). Tumor necrosis factor–α, interleukin-6, and interleukin-8 levels rose by several orders of magnitude (P < .001 versus baseline in all groups), without significant intergroup differences. Conclusions Acetaminophen was the superior antipyretic drug in endotoxemia compared with aspirin. Treatment with acetaminophen ameliorates subjective symptoms induced by endotoxemia without compromising the humoral response of a subject to endotoxin. This observation has clinical interest and may also help to improve the lipopolysaccharide model, which can be used to test anti-inflammatory and anticoagulatory drugs. Clinical Pharmacology & Therapeutics (1999) 66, 51–57

Previous studies have reported divergent findings on the function of the hypothalamic-pituitary-adrenal axis in patients with chronic renal failure (CRF). The low-dose adrenocorticotropin (ACTH) test offers the possibility of unmasking adrenal dysfunction, which might remain undiscovered using the ACTH test with the standard 250-microg dose. Furthermore, the choice of renal replacement therapy (either hemodialysis or continuous ambulatory peritoneal dialysis [CAPD]) might have an impact on adrenal function. To investigate these possibilities, ACTH tests were performed with three different doses (ie, 1, 5, and 250 microg) in 14 CRF patients and in seven healthy controls. Seven of the CRF patients were receiving chronic hemodialysis and seven were receiving CAPD. Basal plasma concentrations of cortisol were comparable in the three groups tested (5.3+/-0.4 microg/dL in the controls, 6.6+/-0.7 microg/dL in the hemodialysis patients, and 7.9+/-1.0 microg/dL in the CAPD patients), whereas basal ACTH concentrations were significantly elevated in the CRF patients (28.5+/-3.8 pg/mL in the hemodialysis patients and 33.0+/-6.0 pg/mL in the CAPD patients) when compared with normal controls (17.0+/-1.4 pg/mL; P < 0.05). All three doses of ACTH resulted in a rapid increase of plasma cortisol concentrations that was comparable in all three groups. In the hemodialysis patients, a trend toward a diminished response to the lowest dose of 1 microg was noticed. We conclude, therefore, that adrenal response to ACTH in various doses is unaffected in CRF independent of whether hemodialysis or CAPD is chosen for renal replacement therapy.

Background Macro-hormones are circulating conjugates of hormones with immunoglobulins, which often artefactually elevate biochemical test results. Particularly when causing only moderate elevation no suspicion will be raised. By far the most frequently encountered macro-hormone is macro-prolactin. Here we report a female patient with rheumatoid arthritis who had persistently and grossly elevated thyroid stimulating hormone (TSH) but normal free thyroxine in electrochemiluminescent assays. Although clinically euthyroid, she was put on thyroxine therapy which caused hyperthyroid symptoms. Methods An analytic interference by macro-TSH was assumed by dilution experiments, polyethylene-glycol-precipitation, the addition of a heterophilic antibody blocking reagent and size exclusion chromatography. Results Further workup, however, revealed the presence of anti-ruthenium antibodies. Conclusions To our knowledge this is the first report of anti-ruthenium antibodies selectively interfering with a TSH assay and causing erratic gross elevation of TSH mimicking macro-TSH.

Background. The coincidence of climacteric symptoms and the beginning of skin aging suggests that estrogen deficiency may be a common and important factor in the perimenopausal woman. Often hormones have been considered important in endogenous aging of the skin, but their role has not been clearly defined. Therefore, we investigated, whether topical treatment of the skin with estrogen could reverse some of the changes in the aging skin. Materials and Methods. The effects of 0.01% estradiol and 0.3% estriol compounds were compared in 59 preclimacteric women with skin aging symptoms. Monthly determinations of estrodiol (E2), follicle-stimulating hormone (FSH), and prolactin (PRL) were done and the monthly clinical monitoring was supplemented by measurements of skin hydration by corneometry and profilometry. In 10 patients, skin biopsies were taken for immunohistochemical determination of collagen types I and III. Results. After treatment for 6 months, elasticity and firmness of the skin had markedly improved and the wrinkle depth and pore sizes had decreased by 61 to 100% in both groups. Furthermore, skin moisture had increased and the measurement of wrinkles using skin profilometry, revealed significant, or even highly significant, decreases of wrinkle depth in the estradiol and the estriol groups, respectively. On immunohistochemistry, significant increases of Type III collagen labeling were combined with increased numbers of collagen fibers at the end of the treatment period. As to hormone levels, only those of PRL had increased significantly and no systemic hormonal side effects were noted. Conclusion. Both estrogen compounds were found to be highly effective in preventing or treating skin aging in perimenopausal women, clinically, by measurement data, and by an increase in collagen Type III.

Objective Parathyroid hormone (iPTH) and fibroblast growth factor 23 (FGF23) are elevated in secondary hyperparathyroidism . In hemodialysis , higher dialysate calcium (1.5 mmol/L) induces intradialytic suppression of iPTH, whereas its impact on FGF23 and markers of bone metabolism is unknown. We assessed the time course of FGF23 and markers of bone metabolism in relationship to dialysate calcium. Design and methods In this prospective cohort study of 19 patients on maintenance hemodialysis, we measured serum calcium (sCa), inorganic phosphate (iP), blood urea nitrogen (BUN), β2-microglobulin (sMG), iPTH, FGF23, aminoterminal propeptide type 1 procollagen (P1NP), C-telopeptide of type I collagen for bone degradation (CTX-I), osteocalcin (OC), bone specific alkaline phosphatase (BALP), and tartrate-resistant acid phosphatase (TRAP5b) during a single hemodialysis session at baseline, 1, 2, and 3 h of dialysis. The time course of measured parameters was compared according to groups of prescribed dialysate calcium of 1.25 mmol/L and 1.5 mmol/L. Results iPTH declined in the 1.5 mmol/L dialysis group as serum calcium increased whereas it tended to increase in the 1.25 mmol/L group without significant changes in serum calcium. Patients on long-term dialysate calcium of 1.5 mmol/L had significantly lower CTX-I levels and tended to lower levels of iPTH, FGF23, OC, P1NP and TRAP5b at the start of dialysis compared to those on 1.25 mmol/L. CTX-I, FGF23 and OC but not BALP, P1NP and TRAP5b decreased during dialysis independent of dialysate calcium. Conclusions In spite of immediate effects on iPTH, dialysate calcium does not acutely affect other parameters of bone and mineral metabolism. Short summary Dialysate calcium concentration is known to have both immediate and longer-term impact on parathyroid hormone levels in hemodialysis patients. Little is known about the acute impact of dialysate calcium on bone metabolism. In this cross-sectional study of prevalent hemodialysis patients, we found no evidence of immediate short-term dialysate calcium-induced changes of fibroblast growth factor 23 or anabolic and catabolic markers of bone turnover during hemodialysis. However, differences in CTX-I and to a lesser extent other parameters between groups of higher and lower dialysate calcium suggest a longer-term effect that remains to be validated.

Postoperative pain is a major cause of ineffective breathing after lung surgery, predisposing patients to hypoxemia. Because potent analgesics like opioids depress ventilation and other analgesic techniques are time-consuming, efficient postoperative pain therapy is difficult. Therefore, a less painful surgical approach could be beneficial. Forty-seven patients with diagnosis of a pulmonary nodule were prospectively studied. Patients were assigned to a video-assisted thoracic surgery (VATS) group (n=22) or a group undergoing axillary thoracotomy (n=25). Visual analogue scale (VAS) scores, plasma glucose levels, plasma epinephrine and plasma norepinephrine levels, as well as arterial oxygen (Pao 2 ) and carbon dioxide (PaCO 2 ) tension were determined the day before surgery, and 3, 15, 24, 48, and 72 h after surgery. Postoperative piritramide (a synthetic morphine compound) demand was recorded. VAS values were significantly lower (p 2 values but PaO 2 values were higher in the VATS group over 72 h, with maximum differences occurring at 15 h after operation: 60.9±1.9 vs 49.2±2.4 mm Hg (p