An Evaluation of Nephrology Literature for Transparency and Reproducibility Indicators: Cross-Sectional Review.

INTRODUCTION: Reproducibility is critical to diagnostic accuracy and treatment implementation. Concurrent with clinical reproducibility, research reproducibility establishes whether the use of identical study materials and methodologies in replication efforts permits researchers to arrive at similar results and conclusions. In this study, we address this gap by evaluating nephrology literature for common indicators of transparent and reproducible research. METHODS: We searched the National Library of Medicine catalog to identify 36 MEDLINE-indexed, English-language nephrology journals. We randomly sampled 300 publications published between January 1, 2014, and December 31, 2018. RESULTS: Our search yielded 28,835 publications, of which we randomly sampled 300 publications. Of the 300 publications, 152 (50.7%) were publicly available, whereas 143 (47.7%) were restricted through paywall and 5 (1.7%) were inaccessible. Of the remaining 295 publications, 123 were excluded because they lack empirical data necessary for reproducibility. Of the 172 publications with empirical data, 43 (25%) reported data availability statements and 4 (2.3%) analysis scripts. Of the 71 publications analyzed for preregistration and protocol availability, 0 (0.0%) provided links to a protocol and 8 (11.3%) were preregistered. CONCLUSION: Our study found that reproducible and transparent research practices are infrequently used by the nephrology research community. Greater efforts should be made by both funders and journals. In doing so, an open science culture may eventually become the norm rather than the exception.

Characteristics and Prognosis of Exercise-Related Sudden Cardiac Arrest.

Introduction: The previous studies about exercise-related sudden cardiac arrest (SCA) have mainly focused on sports activity, but information related to SCA in other forms of physical exercise is lacking. Our aim was to identify characteristics and prognosis of SCA victims in the general population who suffered SCA during physical activity. Methods and results: We collected retrospectively all cases of attempted resuscitation in Oulu University Hospital Area between 2007 and 2012. A total of 300 cases were of cardiac origin. We only included witnessed cases with Emergency Medical System arrival time ≤15 min. Cases of low-intensity physical activity were excluded. A total of 47 SCAs occurred during moderate-to-vigorous physical activity (exercise-group) and 43 cases took place at rest (rest-group). The subjects in exercise-group were younger compared to the rest-group (60 ± 14 years vs. 67 ± 14 years, p = 0.016). The initial rhythm recorded was more often ventricular fibrillation (VF) in exercise-group compared to the rest-group (77 vs. 50%, p = 0.010). Pulseless electrical activity (PEA) was rare in exercise-group compared to the rest -group (2.1 vs. 14%, p = 0.033, respectively). Bystander cardiopulmonary resuscitation (CPR) was more often performed when SCA took place during physical exercise (47 vs. 23 %, p = 0.020). Survival rates to hospital discharge were higher in the exercise-group compared to the rest -group (49 vs. 9.3%, p < 0.0001). Conclusions: SCA occurring during physical activity is more frequently a result of VF and bystander CPR is more often performed. There is also a notably better survival rate to hospital discharge.

Effect of serotonin transporter genotype on self-reported efficacy and activity changes of brain prefrontal area in response to placebo.

Patients benefit from drug therapy not only through pharmacological mechanisms, but also through non-pharmacological action (placebo effect), which may be mediated in part by the prefrontal area of the brain. We consider that the difference between responders and non-responders to placebo might be related to polymorphisms in the serotonin transporter-linked polymorphic region (5-HTTLPR). To study this idea, we performed a randomized double-blind clinical trial using caffeine and lactose (placebo). Activity in the prefrontal area of the brain was measured in terms of blood flow by means of near-infrared spectroscopy (NIRS) as an objective indicator. Self-reported feelings of drowsiness on established scales were used as subjective indicators. Twenty-one subjects in block A took caffeine on the first day and placebo on the third day, and 21 in block B took placebo on the first day and placebo on the third day. After placebo administration, improvement of sleepiness was significantly enhanced, a similar extent to that after caffeine medication. Among the 42 subjects, 22 showed S/S type polymorphism in the serotonin transporter (52.4 %), 17 showed S/L type (40.5 %) and 3 showed L/L type (7.10 %). Statistical analysis of the results indicate that subjects with L/L genotype showed a significantly greater placebo response in terms of both self-reported feeling of drowsiness and blood flow in the prefrontal area of the brain associated with working memory (46 area). Our results indicate that the L/L genotype of 5-HTTLPR, which is rare in Japanese (3.2 %) but common in Americans (32.2 %), may be associated with a greater placebo effect.

Protective effect of hypotaurine against oxidative stress-induced cytotoxicity in rat placental trophoblasts.

INTRODUCTION: Hypotaurine is a precursor of taurine and an antioxidant, and is concentrated in fetal plasma compared to maternal plasma. Hypotaurine is significantly decreased in fetal plasma of ezrin (Vil2) knock-out mice, and fetuses show intrauterine growth retardation. The aim of this study was to characterize the mechanism through which cellular hypotaurine level is maintained in placental trophoblasts, and the effect of hypotaurine on oxidative stress induced by hydrogen peroxide (H2O2). METHODS: Hypotaurine transfer from extracellular fluid and antioxidant effect of hypotaurine were analyzed in rat placental trophoblast TR-TBT 18d-1 cells. RESULTS: We found that hypotaurine is concentrated into rat placental trophoblast TR-TBT 18d-1 cells, and the level of hypotaurine was markedly reduced by culture in medium supplemented with dialyzed fetal bovine serum (FBS) instead of normal FBS. The hypotaurine level recovered almost completely when hypotaurine was added to the culture medium, indicating that intracellular hypotaurine is predominantly supplied by transport across the plasma membrane from extracellular fluid rather than by biosynthesis. Hypotaurine showed a cytoprotective effect against H2O2-induced oxidative damage in TR-TBT 18d-1 cells. Hypotaurine treatment of TR-TBT 18d-1 cells increased antioxidant capacity against hydroxyl radical and peroxyl radical. The concentration of intracellular hydroxyl radical induced by H2O2 in TR-TBT 18d-1 cells was significantly reduced by hypotaurine treatment. DISCUSSION: These results indicate that intracellular hypotaurine is mainly supplied to placental trophoblasts by transfer from extracellular fluid across the plasma membrane, and may play a role in cell protection by scavenging reactive oxygen species.

An epigenome-wide association study of total serum immunoglobulin E concentration.

Immunoglobulin E (IgE) is a central mediator of allergic (atopic) inflammation. Therapies directed against IgE can alleviate hay fever and allergic asthma. Genetic association studies have not yet identified novel therapeutic targets or pathways underlying IgE regulation. We therefore surveyed epigenetic associations between serum IgE concentrations and methylation at loci concentrated in CpG islands genome wide in 95 nuclear pedigrees, using DNA from peripheral blood leukocytes. We validated positive results in additional families and in subjects from the general population. Here we show replicated associations--with a meta-analysis false discovery rate less than 10(-4)--between IgE and low methylation at 36 loci. Genes annotated to these loci encode known eosinophil products, and also implicate phospholipid inflammatory mediators, specific transcription factors and mitochondrial proteins. We confirmed that methylation at these loci differed significantly in isolated eosinophils from subjects with and without asthma and high IgE levels. The top three loci accounted for 13% of IgE variation in the primary subject panel, explaining the tenfold higher variance found compared with that derived from large single-nucleotide polymorphism genome-wide association studies. This study identifies novel therapeutic targets and biomarkers for patient stratification for allergic diseases.

Role of protein kinase A in regulating steroid sulfate uptake for estrogen production in human placental choriocarcinoma cells.

The purpose of this study is to assess the role of the protein kinase A (PKA) in regulating uptake of dehydroepiandrosterone sulfate (DHEAS), an estrogen precursor, by syncytiotrophoblasts. Forskolin, a PKA activator, significantly increased [(3)H]DHEAS uptake and the mRNA expression levels of organic anion transporter (OAT) 4 and CYP19A1 in choriocarcinoma JEG-3 cells, while other steroid sulfate transporters present in the placenta showed no change in expression level. KT5720, a PKA inhibitor, attenuated these effects of forskolin. Accordingly, the PKA pathway appears to play an important role in estrogen synthesis by cooperatively regulating OAT4 and steroidogenic enzymes in syncytiotrophoblasts.

IFPA Meeting 2012 Workshop Report II: epigenetics and imprinting in the placenta, growth factors and villous trophoblast differentiation, role of the placenta in regulating fetal exposure to xenobiotics during pregnancy, infection and the placenta.

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2012 there were twelve themed workshops, four of which are summarized in this report. These workshops related to various aspects of placental biology: 1) epigenetics and imprinting in the placenta; 2) growth factors and villous trophoblast differentiation; 3) role of the placenta in regulating fetal exposure to xenobiotics during pregnancy; 4) infection and the placenta.

Roles of TauT and system A in cytoprotection of rat syncytiotrophoblast cell line exposed to hypertonic stress.

The purpose of this study was to clarify the cytoprotective mechanism(s) induced in a conditionally immortalized syncytiotrophoblast cell line (TR-TBT 18d-1) exposed to hypertonic conditions. Hypertonicity-induced apoptosis of TR-TBT 18d-1 cells, but this was blocked by addition of 1 mM taurine to the culture medium. TauT-knockdown using siRNA revealed that TauT is a major contributor to taurine uptake by TR-TBT 18d-1 cells, at least under normal conditions. Cellular uptake of [(3)H]taurine and [(14)C]betaine by TR-TBT 18d-1 cells cultured under hypertonic conditions was increased compared to that under normal conditions. TauT, BGT-1, ATA2 and HSP70 mRNAs were upregulated by hypertonicity, while OCTN2, ENT1 and CNT1 mRNAs were downregulated. [(3)H]Taurine uptake was strongly inhibited by TauT inhibitors such as hypotaurine and ß-alanine. MeAIB, a system A specific substrate, inhibited hypertonic stress-induced [(14)C]betaine uptake. These results suggest that TauT and system A play cytoprotective roles in syncytiotrophoblasts exposed to hypertonic stress.

Analysis of the impact of genetic variation on human gene expression.

Interindividual variation in gene expression has been convincingly shown to be controlled, in part, by genetic differences. Determining the architecture of genetic variation, the underlying gene expression may allow deeper insight into complex phenotypes, such as differences in disease susceptibility. Mapping genetic variants accounting for expression phenotypes in human cell and tissue panels has rapidly progressed from proof-of-principle experiments to general tools in biomedical discovery. We discuss the general approach and critical considerations for carrying out expression quantitative trait mapping in human tissues.

Common sequence variation in FLNB regulates bone structure in women in the general population and FLNB mRNA expression in osteoblasts in vitro.

Previous data from our group indicate that BMD is linked to chromosome 3p14-p21. Because the filamin B (FLNB gene resides in this region, is the cause of skeletal dysplasias, and was identified among the top genes in our bioinformatics analysis, we hypothesized a role for FLNB in the regulation of bone structure in the general population. Using a tag single nucleotide polymorphism (SNP) approach, a family study of 767 female sibs in which the 3p14-p21 linkage with BMD was previously shown was examined. FLNB variants showing a BMD association were tested in two additional data sets, a study of 1085 UK female twins and a population study (CAIFOS) of 1315 Australian women. Genotype-expression studies were performed in 96 human osteoblast lines to examine the variants in vitro. rs7637505, rs9822918, rs2177153, and rs2001972 showed association with femoral neck (p = 0.0002-0.02) in the family-based study. The twin study provided further support for an association between rs7637505 and femoral neck and spine BMD (p = 0.02-0.03). The CAIFOS study further suggested an association between rs2177153 and rs9822918 and femoral neck BMD (p = 0.004-0.03). Prevalent fractures were increased in carriers of the A allele of rs2177153 (p = 0.009). In vitro studies showed association between rs11130605, itself in strong LD with rs7637505, and FLNB mRNA expression. These findings suggest common variants in FLNB have effects on bone structure in women. Although the location of variants having effects is not entirely consistent, variation at the 5' end of the gene may reflect effects on levels of FLNB transcription efficiency.

Shot noise in ballistic graphene.

We have investigated shot noise in graphene field effect devices in the temperature range of 4.2-30 K at low frequency (f=600-850 MHz). We find that for our graphene samples with a large width over length ratio W/L, the Fano factor F reaches a maximum F ~ 1/3 at the Dirac point and that it decreases strongly with increasing charge density. For smaller W/L, the Fano factor at Dirac point is significantly lower. Our results are in good agreement with the theory describing that transport at the Dirac point in clean graphene arises from evanescent electronic states.

Conditionally immortalized retinal capillary endothelial cell lines (TR-iBRB) expressing differentiated endothelial cell functions derived from a transgenic rat.

The objective of this study was to establish and characterize a retinal capillary endothelial cell line (TR-iBRB) from a newly developed transgenic rat harboring the temperature-sensitive simian virus 40 (SV 40) large T-antigen gene (Tg rat). Retinal capillary endothelial cells were isolated from a Tg rat and cultured in collagen-coated dishes at 37 degrees C for a period of 48 hr. Cells were subsequently cultured at 33 degrees C to activate the large T-antigen. At the third passage, cells were cloned by colony formation and isolated from other cells. Nine immortalized cell lines of retinal capillary endothelial cells (TR-iBRB1 approximately 9) were obtained from a Tg rat. These cell lines had a spindle-fiber shape morphology, expressed the typical endothelial marker, von Willebrand factor, and internalized acetylated-low density lipoprotein. Moreover, vascular endothelial growth factor (VEGF) receptor-2 was expressed in TR-iBRBs. TR-iBRBs expressed a large T-antigen and grew well at 33 degrees C with a doubling time of 19-21 hr. In contrast, cells did not grow at 37 and 39 degrees C due to the reduced expression of large T-antigen, supporting temperature-dependent cell growth. TR-iBRBs expressed GLUT1 and exhibited 3- O -methyl- D -glucose (3-OMG) uptake activity. This 3-OMG uptake was saturable with a Michaelis-Menten constant of 5.56 +/- 0.51 m M and a maximum uptake rate of 45.3 +/- 2.6 nmol min(-1) mg protein(-1). P-Glycoprotein, with a molecular weight of approximately 180 KDa, was expressed in TR-iBRBs. In addition, mdr 1a, mdr 1b and mdr 2 were detected in TR-iBRB2 using RT-PCR. In conclusion, conditionally immortalized retinal capillary endothelial cell lines were established from a transgenic rat harboring the temperature-sensitive SV 40 large T-antigen gene and these lines were shown to exhibit the properties of retinal capillary endothelial cells.

MCT1-mediated transport of L-lactic acid at the inner blood-retinal barrier: a possible route for delivery of monocarboxylic acid drugs to the retina.

PURPOSE: The aim of this study was to characterize L-lactic acid transport using a conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB2) as a model of in vitro inner blood-retinal barrier (iBRB) to obtain a better understanding of the transport mechanism at the iBRB. METHODS: TR-iBRB2 cells were cultured at 33 degrees C, and L-lactic acid uptake was monitored by measuring [14C]L-lactic acid at 37 degrees C. The expression and mRNA level of monocarboxylate transporter (MCT)1 and MCT2 were determined by reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR with specific primers, respectively. RESULTS: The [14C]L-lactic acid uptake by TR-iBRB2 cells increased up to a pH of 5.0 and was inhibited in the presence of 10 mM L-lactic acid. The [14C]L-lactic acid uptake at pH 6.0 was both temperature- and concentration-dependent with a Michaelis-Menten constant of 1.7 mM and a maximum uptake rate of 15 nmol/(30 s mg of protein). This process was reduced by carbonylcyanide p-trifluoromethoxyphenylhydrazone (protonophore), alpha-cyano-4-hydroxycinnamate, and p-chloromercuribenzenesulfonate (typical inhibitors for H+-coupled monocarboxylic acid transport), suggesting that L-lactic acid uptake by TR-iBRB2 cells is a carrier-mediated transport process coupled with an H+ gradient. [14C]L-Lactic acid uptake was markedly inhibited by monocarboxylic acids but not dicarboxylic acids and amino acids. Moreover, salicylic and valproic acids competitively inhibited this process with an inhibition constant of 4.7 mM and 5.4 mM, respectively. Although MCT1 and MCT2 mRNA were found to be expressed in TR-iBRB2 cells, MCT1 mRNA was found to be present at a concentration 33-fold greater than that of MCT2 mRNA using quantitative real-time PCR. [14C]L-Lactic acid was significantly reduced by 5-(N,N-hexamethylene)-amiloride at pH 7.4 and Na+/H+ exchanger I mRNA was expressed in TR-iBRB2 cells. CONCLUSION: L-Lactic acid transport at the iBRB is an H-coupled and carrier-mediated mechanism via MCT1 that is competitively inhibited by monocarboxylate drugs.

Conditionally immortalized brain capillary endothelial cell lines established from a transgenic mouse harboring temperature-sensitive simian virus 40 large T-antigen gene.

Five immortalized brain capillary endothelial cell lines (TM-BBB1-5) were established from 3 transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene (Tg mouse). These cell lines expressed active large T-antigen and grew well at 33 degrees C with a doubling time of about 20 to 30 hours. TM-BBBs also grew at 37 degrees C but not at 39 degrees C. However, growth was restored when the temperature of the culture was lowered to 33 degrees C. Although significant amounts of large T-antigen were shown to be present in the cell culture at 33 degrees C, there was less of this complex at 37 degrees C and 39 degrees C. TM-BBBs expressed the typical endothelial marker, von Willebrand factor, and exhibited acetylated low-density lipoprotein uptake activity. The alkaline phosphatase and gamma-glutamyltranspeptidase activity in TM-BBBs were -10% and 50% to 80% of brain capillary fraction of normal mice, respectively. D-mannitol transport in the both apical-to-basal and basal-to-apical directions across the TM-BBB was 2-fold greater than for inulin. TM-BBBs were found to express GLUT-1 but not GLUT-3, and exhibited concentration-dependent 3-O-methyl-D-glucose (3-OMG) uptake activity with a Michaelis-Menten constant of 6.59 +/- 1.16 mmol/l. Moreover, P-glycoprotein (P-gp) with a molecular weight of -170 kDa was expressed in all TM-BBBs. Both mdr1a and mdr1b mRNA were detected in TM-BBB4 using reverse transcription-polymerase chain reaction (RT-PCR) analysis. [3H]-Cyclosporin A uptake by TM-BBB was significantly increased in the presence of 100 micromol/l verapamil and vincristine, suggesting that TM-BBB exhibits efflux transport activity via P-gp. In conclusion, conditional brain capillary endothelial cell lines were established from Tg mice. This cell line expresses endothelial markers and transporters at the BBB and is able to regulate cell growth, due to the amount of active large T-antigen in the cell, by changing the culture temperature.

Treatment of brachymetatarsia using a semicircular lengthener. 1-3 years results in 6 patients.

6 women with brachymetatarsia involving 9 bones were treated by the use of the Ilizarov semicircular lengthener. The affected bones were the second, third and fourth metatarsals. Ilizarov half-rings were applied on the foot with 5 or 6 half-pins (3 mm in diameter) and a percutaneous osteotomy was done. The short metatarsals were lengthened 0.25 mm twice a day by the patient. The lengthened distance was 15 (10-22) mm and the overall treatment time was 15 (12-25) weeks. The postoperative course was uneventful, with smooth bone regeneration. No bone-grafting was needed. During treatment, the patients could bear full weight and tolerated the fixators well. We conclude that this technique is useful in the treatment of brachymetatarsia.

[Cardiac insufficiency caused by arteriovenous fistula. An unusual complication of spinal surgery]. / Insuffisance cardiaque par fistule artério-veineuse. Une complication inhabituelle de la chirurgie du rachis.

Arteriovenous fistula is one of the main causes of high output cardiac failure. The authors report a case following lumbar disc surgery. There are a number of features which may suggest this complication both during surgery and in the immediate postoperative period which are important because the patient may only become symptomatic a long time after operation with a clinical presentation which leads to a cardiological rather than to a surgical referral.