Teriparatide treatment in a heart transplant patient with a chronic kidney disease and a low-turnover bone disease: a case report.

Low-turnover bone disease is a complication of chronic kidney disease and a long-term steroid therapy. Currently, the only bone anabolic treatment available is teriparatide (TPTD). So far, no data exist in heart transplant patients, and only one single case with histomorphometric analysis of a dialysis patient with a low-turnover bone disease has been published. The current report shows the effect of a 1-year TPTD therapy in a cardiac transplant patient with 10 vertebral and 3 peripheral fractures who had developed a chronic kidney failure while receiving triple immunosuppressive therapy. A transiliac bone biopsy following tetracycline labeling was performed prior and after 1 year of treatment, showing an increase in the bone formation and improvement of the structural indices (20-fold increase of osteoid volume/bone volume, fourfold increase of osteoid surface/bone surface and increases of wall thickness (+15%), trabecular thickness (+9%), and trabecular number (+38%)). Bone mineral density was stable, no new vertebral fractures had occurred, the therapy was well-tolerated, and the patient improved clinically.

Effect of vitamin D3 on bone turnover markers in critical illness: post hoc analysis from the VITdAL-ICU study.

In this post hoc analysis of the VITdAL-ICU study, an RCT in critically ill adults with 25-hydroxyvitamin D levels ≤20 ng/ml, vitamin D3 did not have a significant effect on ß-Crosslaps and osteocalcin. INTRODUCTION: Observational studies have shown accelerated bone loss in ICU survivors. A reversible contributor is vitamin D deficiency. In a post hoc analysis of the VITdAL-ICU study, we evaluated the effect of high-dose vitamin D3 on the bone turnover markers (BTM) ß-Crosslaps (CTX) and osteocalcin (OC). METHODS: The VITdAL-ICU study was a randomized, double-blind, placebo-controlled trial in critically ill adults with 25-hydroxyvitamin D levels ≤20 ng/ml who received placebo or high-dose vitamin D3 (a loading dose of 540,000 IU and starting 1 month after the loading dose five monthly maintenance doses of 90,000 IU). In this analysis on 289 survivors (209 telephone, 80 personal follow-up visits), BTM were analyzed on days 0, 3, 7, 28, and 180; self-reported falls and fractures were assessed. Bone mineral density (BMD) was measured after 6 months. RESULTS: At baseline, CTX was elevated; OC was low in both groups-after 6 months, both had returned to normal. There were no differences between groups concerning BTM, BMD, falls, or fractures. In linear mixed effects models, CTX and OC showed a significant change over time (p < 0.001, respectively), but there was no difference between the vitamin D and placebo group (p = 0.688 and p = 0.972, respectively). CONCLUSIONS: Vitamin D supplementation did not have a significant effect on BTM. Further studies should assess the effectiveness of vitamin D on musculoskeletal outcomes in ICU survivors.

Epidemiology of distal forearm fractures in Austria between 1989 and 2010.

UNLABELLED: Only few studies have been published hitherto on country-specific incidence of distal forearm fracture. In the prevailing study, incidences were estimated, and trend analyses were performed for the entire Austrian population aged ≥50á. Incidence decreased significantly in women, but not in men, over the past 12 years of observation. INTRODUCTION: To estimate incidence of distal forearm fracture and assess incidence trends in the entire Austrian population aged ≥50á from 1989-2010 for inpatient fractures and from 1999 to 2010 for all fractures. METHODS: The number of inpatient forearm fractures was obtained from the Austrian Hospital Discharge Register (AHDR) for the entire population aged ≥50á from 1989 to 2010. Total number of distal forearm fractures was modeled using patient-level data on 36,327 patients with distal forearm fractures. Crude and age-standardized incidence rates (cases per 100,000) were estimated in 5-year age intervals. To analyze the change in incidence over time, average annual changes expressed as incidence rate ratios (IRR) were calculated. RESULTS: For all distal forearm fractures, age-standardized incidence in women in 1999 and 2009 were estimated at 709 (95 % CI 675-743) and 607 (578-637), respectively. The age-standardized incidences in men the same years were estimated at 171 (156-185) and 162 (151-174), respectively. IRR analyses showed a significant decrease in women (-1.1 %, p < 0.01) but not in men (-0.8 %, p > 0.05) over the last 12 years (1999-2010). CONCLUSION: Incidence of distal forearm fracture in the entire Austrian population is comparable to hip fracture incidence which is known to be among the highest worldwide. However, trend analyses reveal a significant decrease for all distal forearm fractures in women, but not in men, over the last 12 years.

Vitamin D deficiency in the ICU: a systematic review.

In the last decade, few substances have been discussed as controversially as vitamin D. In the last few years, vitamin D research has now also found its way into the intensive care unit (ICU). Vitamin D deficiency is commonly found in the ICU and is associated with adverse outcomes including excess mortality, longer length of stay, higher sepsis incidence, longer mechanical ventilation. But how should one single vitamin be capable of such an impact? It has to be kept in mind that vitamin D is not a classic vitamin at all. It can be synthesized in sufficient amounts by the human body, it has a nuclear receptor and a large number of genes are under direct or indirect control of vitamin D. Furthermore, both the vitamin D receptor and the 1-α hydroxylase which is required to activate vitamin D are widely distributed in the human body. Unfortunately, as in other settings, a large body of observational data is opposed to only a few intervention studies. This article seeks to review the current observational and interventional literature concerning vitamin D status in the context of critical care, its effects on this highly vulnerable population and possible treatment strategies as well as an outlook on research that is necessary in the future.

Epidemiology of proximal humeral fractures in Austria between 1989 and 2008.

UNLABELLED: Incidence rates of proximal humeral fractures in Austria over a period of twenty years (1989-2008) were estimated. Age standardized incidence rates increased until 2008, primarily driven by an increase in incidence rates in women. INTRODUCTION: The aim of the prevailing study was to estimate incidence rates of proximal humeral fractures and to assess changes in trend in the Austrian population aged 50 years and above, over a period of 20 years (1989-2008). METHODS: Number of proximal humeral fractures were obtained from the Austrian Hospital Discharge Register for the entire population >50 years of age. Adjustment factors were determined for multiple registrations of the same diagnosis, and for the fact that not all patients with proximal humeral fractures are treated in an inpatient setting. To analyze the overall change in this type of fracture for the period, average annual changes expressed as incidence rate ratios were calculated. RESULTS: The estimated age-standardized incidence (fractures per 100,000 individuals) of proximal humeral fractures among Austrians >50 years of age increased in men from 112 (95% CI, 99-124) to 141 (129-153) and in women from 222 (202-241) to 383 (360-406). The increase appeared to be linear with no leveling off towards the end of the study period. CONCLUSION: While some caution is necessary when interpreting the results given the use of adjustment factors, there appears to have been a rise in the incidence of proximal humeral fractures in Austria in both men and women, with no leveling off in recent years. The reasons for this are not clear, but in the light of previously reported leveling off in the increase in the incidence of hip fractures, a change in the patterns of falls cannot be ruled out.

Low bone turnover and increase of bone mineral density in a premenopausal woman with postoperative hypoparathyroidism and thyroxine suppressive therapy.

We report the case of a 36-year-old woman who developed permanent hypoparathyroidism after thyroidectomy for differentiated thyroid carcinoma. A 6-year follow-up showed an increase of 11% in absolute bone mineral density at the spine and 6% at the hip accompanied by low bone turnover despite thyroid-stimulating hormone suppressive thyroxine therapy.

[Online information for relatives of critically ill patients : Pilot test of the usability of an ICU families website]. / Onlineinformation für Angehörige von kritisch Kranken : Pilottestung zur Nutzbarkeit der ICU Families Website.

BACKGROUND: Relatives of intensive care patients have a very high need for information. This is due to the acute and serious, often life-threatening illness of the patients and the very complex and technical environment of an intensive care unit (ICU). Unmet needs for information can increase anxiety, sleep disorders, stress, and depressive symptoms in the relatives. OBJECTIVES: The potential of the ICU families website in terms of usability and functionality during real-time testing were evaluated. METHODS: The ICU families project created a dynamic online information platform in the form of a password-protected website. It contains pictures, written explanations, 5 movies, a forum and a diary function. The usability of the website was tested among 10 lay people and 10 experts (7 nurses and 3 physicians) according to the Think Aloud Method. RESULTS: The outcome is qualitative feedback based on video documentation by laypeople and suggestions by experts. Criticisms mentioned by the test subjects were insufficient image material, small size of the operator contact link and lack of a home button. With a mean of 9.1 (rating scale, 0 = very poor, 10 = very good), the website was almost universally recommended by the experts. CONCLUSIONS: This usability test of a website for relatives of ICU patients conducted among 20 test subjects showed the biggest challenges related to solving individual test scenarios and provided valuable hints for improving website usability. Features of the website highlighted as positive were the clear layout, the symbols, the diary and the consideration of children. This information was used to improve the site for subsequent roll-out in a randomized, controlled and multicentre study.

Vitamin D and critical illness: what endocrinology can learn from intensive care and vice versa.

The prevalence of vitamin D deficiency in intensive care units ranges typically between 40 and 70%. There are many reasons for being or becoming deficient in the ICU. Hepatic, parathyroid and renal dysfunction additionally increases the risk for developing vitamin D deficiency. Moreover, therapeutic interventions like fluid resuscitation, dialysis, surgery, extracorporeal membrane oxygenation, cardiopulmonary bypass and plasma exchange may significantly reduce vitamin D levels. Many observational studies have consistently shown an association between low vitamin D levels and poor clinical outcomes in critically ill adults and children, including excess mortality and morbidity such as acute kidney injury, acute respiratory failure, duration of mechanical ventilation and sepsis. It is biologically plausible that vitamin D deficiency is an important and modifiable contributor to poor prognosis during and after critical illness. Although vitamin D supplementation is inexpensive, simple and has an excellent safety profile, testing for and treating vitamin D deficiency is currently not routinely performed. Overall, less than 800 patients have been included in RCTs worldwide, but the available data suggest that high-dose vitamin D supplementation could be beneficial. Two large RCTs in Europe and the United States, together aiming to recruit >5000 patients, have started in 2017, and will greatly improve our knowledge in this field. This review aims to summarize current knowledge in this interdisciplinary topic and give an outlook on its highly dynamic future.

Short related sequences in the cytoplasmic domains of CD4 and CD8 mediate binding to the amino-terminal domain of the p56lck tyrosine protein kinase.

We report that the cytoplasmic domains of the T-lymphocyte glycoproteins CD4 and CD8 alpha contain short related amino acid sequences that are involved in binding the amino-terminal domain of the intracellular tyrosine protein kinase, p56lck. Transfer of as few as six amino acid residues from the cytoplasmic domain of the CD8 alpha protein to the cytoplasmic domain of an unrelated protein conferred p56lck binding to the hybrid protein in HeLa cells. The common sequence motif shared by CD4 and CD8 alpha contains two cysteines, and mutation of either cysteine in the CD4 sequence eliminated binding of p56lck.p56lck also contains two cysteine residues within its CD4-CD8 alpha-binding domain, and both are critical to the interaction with CD4 or CD8 alpha. Because the interaction does not involve disulfide bond formation, a metal ion could stabilize the complex.

Serum sclerostin levels in renal cell carcinoma patients with bone metastases.

Sclerostin has been proposed as a potent inhibitor of bone formation. Sclerostin antibodies are under clinical development to treat osteoporosis and metastatic bone disease. Serum sclerostin level is elevated in multiple myeloma, an osteolytic malignancy, where it might serve as predictive marker for the use of sclerostin-directed antibodies. As renal cell carcinoma (RCC) patients often present with osteolytic metastases, we aimed to investigate serum sclerostin levels in RCC patients. Our study included 53 RCC patients (19 with bone metastases, 25 with visceral metastases and 9 with localized disease) and 53 age- and gender-matched non-osteoporotic controls. Frozen serum samples were subjected to sclerostin quantitative sandwich ELISA. The mean serum sclerostin levels of RCC patients and controls were 45.8 pmol/l and 45.1 pmol/l, respectively (p = 0.86). Analysis of variance showed no difference between the subgroups of RCC patients with regard to visceral or bone metastases or localized disease (p = 0.22). There was no significant association between eGFR (estimated glomerular filtration rate) and serum sclerostin levels in RCC patients (r = 0.05; p = 0.74) and controls (r = 0.06; p = 0.68). Our results indicate that serum sclerostin levels appear not to be a valuable biomarker to assess the occurrence of bone metastases in RCC patients.

Mapping of the p56lck-mediated phosphorylation of GAP and analysis of its influence on p21ras-GTPase activity in vitro.

The protein tyrosine kinase p56lck and other members of the src family can transduce signals from activated cell-surface receptors. As we showed earlier the GTPase-activating protein (GAP), a regulator of p21ras, is a substrate of p56lck. Here, tryptic peptides of p56lck-phosphorylated GAP were generated and analyzed by two-dimensional thin layer chromatography and mass spectroscopy. Results revealed that p56lck phosphorylates GAP specifically on Tyr-460 in vitro and in vivo. The effect of tyrosine phosphorylation of GAP on its GTPase-activating activity versus p21ras was then tested using a p21ras-dependent GTPase assay system. Our results demonstrate that p56lck-mediated tyrosine phosphorylation of GAP is not sufficient to change directly its effect on the intrinsic GTPase activity of p21ras.

Two transcripts of the same ecdysterone-controlled gene are differentially associated with ribosomes.

The ecdysterone-controlled gene I-18C of Chironomus tentans produces two transcripts by differential splicing: a 1.8-kb RNA, with an open reading frame (ORF) of 417 nucleotides (nt) and a 4.6-kb RNA, with no ORF longer than 270 nt. Centrifugation of cytoplasmic extracts in velocity sedimentation sucrose gradients and CsCl-buoyant-density gradients demonstrates that the 1.8-kb RNA is incorporated into polysomes. The 4.6-kb RNA, however, exhibits characteristics of free ribonucleic acid-protein complexes and monosomes.

Domain organization and molecular characterization of 13 two-component systems identified by genome sequencing of Streptococcus pneumoniae.

In bacteria, adaptive responses to environmental stimuli are often initiated by two-component signal transduction systems (TCS). The prototypical TCS comprises two proteins: a histidine kinase (HK, hk) and a response regulator (RR rr). Recent research has suggested that compounds that inhibit two-component systems might have good antibacterial activity. In order to identify TCS that are crucial for growth or virulence of Streptococcus pneumoniae, we have examined the genomic sequence of a virulent S. pneumoniae strain for genes that are related to known histidine kinases or response regulators. Altogether 13 histidine kinases and 13 response regulators have been identified. The protein sequences encoded by these genes were compared with sequences deposited in public databases. This analysis revealed that two of the 13 pneumococcal TCSs have been described before (ciaRH and comDE) and two are homologous to the yycFG and the phoRP genes of Bacillus subtilis. All the pneumococcal response regulators contain putative DNA binding motifs within the C-terminal output domain, implying that they are involved in transcriptional control. Two of these response regulators are obviously the first representatives of a new subfamily containing an AraC-type DNA-binding effector domain. To assess the regulatory role of these transcription factors, we disrupted each of the 13 response regulator genes by insertional mutagenesis. All the viable mutant strains with disrupted response regulator genes were further characterized with regard to growth in vitro, competence, and experimental virulence. Two response regulator genes could not be inactivated, indicating that they may regulate essential cellular functions. The possibility of using these systems as targets for the development of novel antibacterials will be discussed.

An improved vector system for insertional gene inactivation inspired by the tmRNA-tagging system of S. pneumoniae.

Insertional mutagenesis is a technique often used to inactivate genes in Streptococcus pneumoniae. Using conventional vectors, a 5' segment of the targeted gene remains under the control of the gene's authentic promoter following gene disruption. Thus, the expression of a functional peptide and the misinterpretation of results in consequence cannot be excluded. To circumvent this problem, we have developed a plasmid for insertional mutagenesis based on the tmRNA-tagging system of S. pneumoniae which ensures that any protein expressed after gene disruption is degraded. Insertional mutagenesis using this vector results in the targeted gene being tagged with a tmRNA-derived sequence coding for a proteolysis tag. Here we show that the translation product of a gene tagged by this method is not detectable by Western blotting, suggesting that the protein was degraded. This modified vector allows total inactivation of genes with a reliability that cannot be achieved by conventional vectors for insertional mutagenesis. This approach can be applied to other bacterial species.

Csk-mediated phosphorylation of substrates is regulated by substrate tyrosine phosphorylation.

Csk is a cellular protein tyrosine kinase (PTK) that has been shown to specifically regulate the activity of Src kinase family members by phosphorylation of a carboxy-terminal tyrosine residue. The molecular mechanisms controlling Csk regulation and its substrate specificity have not been elucidated. Here we report a novel type of overlay kinase assay that allows to probe for Csk-mediated phosphorylation of cellular substrates separated by polyacrylamide gel electrophoresis and transferred to nitrocellulose filters. Most of the cell lines analyzed with this method revealed only a few potential Csk substrates. However, an increased number of Csk substrates was detected in NIH3T3 cells expressing a constitutively activated form of the Src kinase Lck or in PC12 and NIH3T3 cells that had been treated with pervanadate. These cells all display an increased level of cellular protein tyrosine phosphorylation which led to the conclusion that Csk preferentially phosphorylates tyrosine-phosphorylated proteins. To verify this hypothesis we analyzed Csk-mediated phosphorylation of recombinant Lck, a known Csk substrate. Results demonstrated that autophosphorylation of Lck (at Tyr394) facilitates Csk-mediated phosphorylation of Lck at its regulatory site (Tyr505). Subsequent peptide binding studies revealed that Csk can bind to a peptide corresponding to the Lck-autophosphorylation site only when it is phosphorylated. These findings suggest that autophosphorylation of Lck at Tyr394 triggers an interaction with Csk and thereby facilitates subsequent phosphorylation and inactivation of Lck. The phosphorylation of other cellular Csk substrates may be regulated by a similar mechanism.

Reticulocyte hemoglobin content allows early and reliable detection of functional iron deficiency in blood donors.

BACKGROUND: Frequent blood donations may lead to a depletion of body iron stores resulting in manifest anemia. Reticulocyte hemoglobin content (CHr) - a marker for impaired hemoglobinisation (IH) caused by functional iron deficiency (FID) - was investigated regarding its value as a routine screening parameter in frequent whole blood donors. METHODS: In a prospective study, 917 frequent blood donors and 688 first time or reactivated donors were tested for iron status and red blood cell count, including CHr. The ferritin index as a marker to indicate absent iron stores (AIS) was calculated. RESULTS: Depending on the number of donations during the preceding 12 months, AIS were detected in up to 21.4% of male and 27.8% of female donors, respectively. IH was present in up to 6.4% male and 16.7% female donors with 2 and 4 preceding donations, respectively. The defined CHr cut-off value was 28.0 pg to detect IH in frequent whole blood donors with AIS, leading to a test specificity of 98.2% (positive predictive value, PPV: 57.7%) in male and of 97.8% (PPV: 82.9%) in female donors. CONCLUSION: Determination of CHr is feasible to detect FID resulting in IH in frequent blood donors. It may help to prevent the development of anemia in frequent blood donors and also can help to decide whether donor deferral or even iron substitution need to be recommended.

Relationship between plasma aldosterone concentration and soluble cellular adhesion molecules in patients referred to coronary angiography.

OBJECTIVE: Evidence is emerging that aldosterone contributes to the development and progression of atherosclerosis and cardiovascular disease. Little is known, however, regarding an association between circulating aldosterone levels and soluble cellular adhesion molecules in humans. METHODS: We investigated the relationship between plasma aldosterone concentration (PAC) and soluble cellular adhesion molecules in a large cohort of patients referred to coronary angiography. After exclusion of patients with ongoing mineralocorticoid receptor blocker use, oral contraceptive or hormone replacement therapy, 1,733 patients (mean age: 62.5±10.8 years; 26.4%% women; mean PAC: 101.5±93.5 pg/mL) remained eligible for analyses. RESULTS: Pearson correlation analysis as well as age and gender adjusted partial correlation analysis revealed a positive association between PAC and soluble (s) E-, L- and P-selectin levels but not with sICAM-1 and sVCAM-1, respectively. In multivariate adjusted analyses of covariance (ANCOVA) sE- (p=0.026), sL- (p=0.049) and sP-selectin (p<0.001) levels increased steadily from the first (reference) to the third gender-specific tertile of PAC. No significant variation across PAC tertiles was found for sICAM-1 (p=0.767) and sVCAM1 (p=0.425) levels, respectively. Finally, multivariate regression analyses revealed circulating aldosterone as an important predictor for soluble selectin levels. CONCLUSION: Our findings in a large cohort of patients indicate that upregulation of selectins might represent a novel mechanism of aldosterone mediated development and progression of atherosclerosis. In view of aldosterone as a novel cardiovascular risk factor independent of angiotensin II, our findings warrant further interventional studies which should evaluate anti-atherosclerotic effects of aldosterone blocking treatment strategies in humans.