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Nephron loss dramatically increases tubular phosphate to concentrations that exceed supersaturation. Osteopontin (OPN) is a matricellular protein that enhances mineral solubility in solution; however, the role of OPN in maintaining urinary phosphate solubility in CKD remains undefined.Here, we examined (Tubular OPN expression was dramatically increased in all studied CKD murine models. Kidney OPN gene expression and urinary OPN/Cr ratios increased before changes in traditional biochemical markers of kidney function. Moreover, a reduction of nephron numbers alone (by unilateral nephrectomy) was sufficient to induce OPN expression in residual nephrons and induction of CKD in OPN-null mice fed excess phosphate resulted in severe nephrocalcinosis. Neutralization of the ASARM motif of OPN in phosphaturic mice resulted in severe nephrocalcinosis that mimicked OPN-null CKD mice. Lastly,Kidney OPN expression increases in early CKD and serves a critical role in maintaining tubular mineral solubility when tubular phosphate concentrations are exceedingly high, as in late-stage CKD. Calcium-phosphate nanocrystals may be a proximal stimulus for tubular OPN production.

Emotional reactions and transmissions are crucial to host-tourist interaction yet lacking in research, particularly from the host viewpoint. To deepen understanding of host-tourist interaction, this study took a host perspective to examine emotional contagion from tourists to hosts. By adopting video-vignette based interaction scenarios and cutting-edge techniques (e.g., FaceReader), a real-time multi-modal investigation was undertaken to reveal mechanism underlying emotional contagion of Hong Kong residents from Mainland Chinese tourists. Results theoretically consolidated the dual-process mechanism underpinning automatic emotional contagion and empirically verified an Emotional Contagion Model (ECM) from tourists to hosts. The compelling effects of mimicry, interaction context and stereotypes explained the emotional convergence and divergence between hosts and tourists. The study extended the knowledge boundary of host-tourist interaction to micro-level interpersonal emotional connection. Moreover, the verified ECM theoretically advances emotional contagion mechanism in the social psychology literature. Practical guidelines for host-tourist relation management and sustainable destination development were provided.

Individuals with autosomal dominant polycystic kidney disease have a higher incidence of stone formation than the general population. However, there are no cystic animal models known to develop stones. Cystic mice compound heterozygous for hypomorphic Pkd1(V) and Pkd1(RC) alleles develop cystic kidneys within a few weeks of birth but live beyond 20 wk of age, allowing for the study of cystic comorbidities including stone formation. Cystic Pkd1(V)(/)(RC) mice were euthanized at 3, 13, or 26 wk of age, and their kidneys were analyzed by microcomputed tomography (µCT) for stone formation. Mice had occasional mineral aggregates that could be detected by µCT analysis at 3 wk of age. At 13 or 26 wk of age, numerous white masses were visible beneath the kidney surface. µCT analysis confirmed the masses to be large mineral stone deposits throughout the renal cortex, with mineral content increasing with age. Staining of histological sections with alizarin red and von Kossa suggested that the stone deposits were composed primarily of calcium and phosphate. Microdissection confirmed stones localized within cyst lumens. Analysis of individual stones by µCT and infrared spectroscopy confirmed apatite mineral composition. Urinalysis revealed elevated levels of phosphate and citrate at 3 wk of age and lower pH and elevated levels of calcium and citrate at 13 wk of age, suggesting altered phosphate and calcium homeostasis as a potential cause of mineralization and renal stone formation. This is the first animal model exhibiting overt kidney stone formation in the context of cystic kidney disease. NEW & NOTEWORTHY Compound heterozygous Pkd1(V/RC) mice were found to form calcium phosphate-containing stones within cysts of the renal cortex by 13 wk of age. This is the first polycystic kidney disease animal model exhibiting spontaneous stone formation. A growing body of evidence suggests a link between renal stone formation and cystic kidney disease. This mouse model may be useful for studying the interplay between stone and cyst formation and the functional role of polycystins in mineral homeostasis.

Integrating sense in a thin artificial muscle fiber for environmental adaption and actuation path tracing, as a snail tentacle does, is highly needed but still challenging because of the interfacing mismatch between the fiber’s actuation and sensing components. Here, we report an artificial neuromuscular fiber by wrapping a carbon nanotube (CNT) fiber core in sequence with an elastomer layer, a nanofiber network, and an MXene/CNT thin sheath, achieving the ingenious sense-judge-act intelligent system in an elastic fiber. The CNT/elastomer components provide actuation, and the sheath enables touch/stretch perception and hysteresis-free cyclic actuation tracing due to its strain-dependent resistance. As a whole, the coaxial structure builds a dielectric capacitor that enables sensitive touchless perception. The key to seamless integration is to use a nanofiber interface that allows the sensing layer to adaptively trace but not restrict actuation. This work provides promising solutions for closed-loop control for future intelligent soft robots.

Introduction Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cyst growth and a loss of functioning renal mass, but a decline in glomerular filtration rate (GFR) and onset of end-stage renal disease (ESRD) occur late in the disease course. There is therefore a great need for early prognostic biomarkers in this disorder. Methods We measured baseline serum fibroblast growth factor 23 (FGF23) levels in 192 patients with ADPKD from the Consortium for Radiologic Imaging Studies of PKD (CRISP) cohort that were followed for a median of 13 years and tested the association between FGF23 levels and change over time in height-adjusted total kidney volume (htTKV), GFR, and time to the composite endpoints of ESRD, death, and doubling of serum creatinine. Results Patients in the highest quartile for baseline FGF23 level had a higher rate of increase in htTKV (0.95% per year, P = 0.0016), and faster rate of decline in GFR (difference of −1.03 ml/min/1.73 m2 per year, P = 0.005) compared with the lowest quartile, after adjusting for other covariates, including htTKV and genotype. The highest quartile of FGF23 was also associated with a substantial increase in risk for the composite endpoint of ESRD, death, or doubling of serum creatinine (hazard ratio [HR] of 2.45 in the fully adjusted model, P = 0.03). Conclusion FGF23 is a prognostic biomarker for disease progression and clinically important outcomes in ADPKD, and has additive value to established imaging and genetic biomarkers., Graphical abstract

Background Recent evidence suggests the systemic accumulation of by-products of gut microbes contributes to cardiovascular morbidity in patients with CKD. Limiting the generation of toxic bacterial by-products by manipulating the intestinal microbiota may be a novel strategy for reducing cardiovascular disease in CKD. Rifaximin is a minimally absorbed, oral antibiotic that targets intestinal pathogens and is commonly used as chronic therapy for the prevention of encephalopathy in patients with cirrhosis. Methods We conducted a randomized, double-blinded, placebo-controlled trial to determine the effect of a 10-day course of oral rifaximin 550 mg BID versus placebo on circulating concentrations of gut-derived cardiovascular toxins and proinflammatory cytokines in patients with stage 3–5 CKD (n=38). The primary clinical outcome was change in serum trimethylamine N-oxide (TMAO) concentrations from baseline to study end. Secondary outcomes included change in serum concentrations of p-cresol sulfate, indoxyl sulfate, kynurenic acid, deoxycholic acid, and inflammatory cytokines (C-reactive protein, IL-6, IL-1β), and change in composition and diversity of fecal microbiota. Results A total of 19 patients were randomized to each of the rifaximin and placebo arms, with n=17 and n=14 completing both study visits in these respective groups. We observed no difference in serum TMAO change (post-therapy minus baseline TMAO) between the rifaximin and placebo groups (mean TMAO change −3.9±15.4 for rifaximin versus 0.5±9.5 for placebo, P=0.49). Similarly, we found no significant change in serum concentrations for p-cresol sulfate, indoxyl sulfate, kynurenic acid, deoxycholic acid, and inflammatory cytokines. We did observe differences in colonic bacterial communities, with the rifaximin group exhibiting significant decreases in bacterial richness (Chao1, P=0.02) and diversity (Shannon H, P=0.05), along with altered abundance of several bacterial genera. Conclusions Short-term rifaximin treatment failed to reduce gut-derived cardiovascular toxins and inflammatory cytokines in patients with CKD. Clinical Trial registry name and registration number Rifaximin Therapy in Chronic Kidney Disease, NCT02342639

Background Coronavirus disease 2019 (COVID-19) has widely spread all over the world since the beginning of 2020. It is desirable to develop automatic and accurate detection of COVID-19 using chest CT. Purpose To develop a fully automatic framework to detect COVID-19 using chest CT and evaluate its performance. Materials and Methods In this retrospective and multicenter study, a deep learning model, the COVID-19 detection neural network (COVNet), was developed to extract visual features from volumetric chest CT scans for the detection of COVID-19. CT scans of community-acquired pneumonia (CAP) and other non-pneumonia abnormalities were included to test the robustness of the model. The datasets were collected from six hospitals between August 2016 and February 2020. Diagnostic performance was assessed with the area under the receiver operating characteristic curve, sensitivity, and specificity. Results The collected dataset consisted of 4352 chest CT scans from 3322 patients. The average patient age (±standard deviation) was 49 years ± 15, and there were slightly more men than women (1838 vs 1484, respectively; P = .29). The per-scan sensitivity and specificity for detecting COVID-19 in the independent test set was 90% (95% confidence interval [CI]: 83%, 94%; 114 of 127 scans) and 96% (95% CI: 93%, 98%; 294 of 307 scans), respectively, with an area under the receiver operating characteristic curve of 0.96 (P < .001). The per-scan sensitivity and specificity for detecting CAP in the independent test set was 87% (152 of 175 scans) and 92% (239 of 259 scans), respectively, with an area under the receiver operating characteristic curve of 0.95 (95% CI: 0.93, 0.97). Conclusion A deep learning model can accurately detect coronavirus 2019 and differentiate it from community-acquired pneumonia and other lung conditions. © RSNA, 2020 Online supplemental material is available for this article.

Recreation experience has long been studied for its close relationship to human health and personal development. Previous research focused mainly on the experiential and on-site outcomes. This stud...

Studies in rodents with reduced nephron mass have suggested a strong positive correlation between dietary phosphate consumption and CKD progression. Prior work by our group demonstrated that dietary phosphate restriction can prevent tubular injury and microcyst formation in rodents with glomerulonephritis. Tubular injury and cystic dilation of tubules are key contributors to kidney function decline in polycystic kidney disease (PKD). Here, we determined whether dietary phosphate restriction slows renal cyst growth and fibrosis in a mouse model of PKD. Pcy/pcy mice received a normal phosphate (0.54%) or a phosphate-restricted (0.02%) diet ( n = 10/group) from 7 to 20 wk of age. All of the other major dietary constituents, including protein source and content, were comparable between the two diets. At 20 wk, body weight, kidney weight-to-body weight ratio (KW/BW), cystic area, cyst number, and kidney fibrosis were quantified. Pcy/pcy mice fed a phosphate-restricted diet had lower serum phosphate, fibroblast growth factor 23, and parathyroid hormone levels, along with elevated serum calcium levels and increased kidney Klotho gene expression compared with mice that consumed the control diet. Dietary phosphate restriction resulted in a 25% lower KW/BW ratio and reduced the cyst number, cystic index, and gene expression for the tubular injury markers neutrophil gelatinase-associated lipocalin and interleukin-18. Mice fed the phosphate-restricted diet exhibited lower kidney expression for pathways involved in collagen deposition and myofibroblast activation (collagen type I-α1, phosphorylated SMAD3, and α-smooth muscle actin); however, histological differences in kidney fibrosis were not appreciated. Dietary phosphate restriction slows cystogenesis and inhibits the activation of key pathways in the generation of kidney fibrosis in PKD mice.

At present, the best treatment for primary patellar dislocation (PPD) has not been unified. Moreover, meta-analyses comparing the non-surgical and surgical treatments of PPD are lacking. Thus, we aimed to compare the clinical efficacy of surgical or non-surgical treatment of PPD. Randomized controlled studies of surgical and non-surgical treatments of PPD from 1966 to 2018 were retrieved from the following databases: PubMed, EMBASE, Cochrane Library, Wanfang Database, China Knowledge Network, Google Scholar, and Weipu Database. We screened for literature that met the inclusion criteria and extracted useful data for our meta-analysis. Nine studies, involving 492 patients, met the inclusion criteria and were analyzed in this study. The recurrence rate of patellar dislocation in the surgical group was lower than that in the non-surgical group (P = 0.04]). Subgroup analysis according to the follow-up time showed that the Kujala score (P

Clustered regularly interspaced short palindromic repeats (CRISPR) and its associated protein gene system can limit the horizontal gene transfer, thereby effectively preventing the invasion of foreign gene elements such as bacteriophages. CRISPR arrays of different bacteria are diverse. Based on the differences in the CRISPR system, this review summarizes the application of CRISPR in food-borne pathogen evolution analysis, detection and typing, virulence and antibiotic resistance in recent years. We also address bacterial detection typing method developed based on the characteristics of CRISPR arrays and the association of CRISPR with virulence and drug resistance of food-borne pathogens. The shortcomings of CRISPR in evolution, detection and typing, virulence and resistance applications are analyzed. In addition, we suggest standardizing CRISPR typing methods, improving and expanding the CRISPR database of pathogenic bacteria, and further exploring the co-evolution relationship between phages and bacteria, to provide references for further exploration of CRISPR functions.

Background Recently, more and more attention has been paid to the role of oral microbiota in hypertension. It was reported that the disorder of tongue coating microbiota would significantly increase systolic blood pressure, yet the characteristics of tongue coating microbiota of hypertensives remain unknown. Microbiota is regulated by genes, G-quadruplex (G4) is a secondary structure of nucleic acid, which plays an important role in the regulation of microbial biologic features. there are many G4 ligands in oral administration, but how G4 ligands affect the bacterial biological phenotype needs further exploration. Results We used metagenomics for analysis of 58 subjects including 23 healthy subjects and 35 hypertensives, and bioinformatics technology for detecting G4 characteristic sequences, finally verified by biological and chemical experiments. We found that Actinomyces decreased significantly in the hypertension group with the highest average maximum putative G-quadruplex forming sequences (PQS) and GC quantity. We also screened out two species with significantly different abundance between two groups, Actinomyces odontolyticus and Acinetobacter baumannii. A. odontolyticus had higher GC% and frequency of PQS per 1000bp in the genome, which led to differential inhibition of bacterial growth, metabolism, biofilm formation by G4 ligand, sanguinarine. Major Facilitator Superfamily (MFS) was found to be involved in these biological phenomena, we found that sanguinarine could bind and stabilize the G4 structure related to MFS and further inhibited the expression of MFS.ConclusionsDifferent quantities of G4 sequences in the bacterial genome affect G4 ligand sensitivity in hypertension-associated tongue coating species, A. odontolyticus and A. baumannii. G4 ligand (sanguinarine) can bind and stabilize the G4 characteristic sequence of the MFS gene to inhibit the expression, and then inhibit the growth, biofilm formation and metabolism. This study provides a theoretical basis for the selection of G4 based drugs in the oral cavity.

Road construction offers a unique lens through which to investigate tourism mobility. To date, research has focused on the socio-cultural effects of road construction, such as its influence on tourists’ movements and its hindrance to tourism development, with less use of systematic methods to analyze road construction-related conflicts. Accordingly, this study comprised a systematic analysis of road construction-related conflicts in Yubeng, China, and potential strategies to solve the underlying mobility dilemmas. A geo-historical trajectory of conflicts was examined, and road construction conflicts were categorized as involving resource competition, tourism dilemma, modern anxiety, or protection paradox. Then, formal conflict analysis and an evolutionary game model were used to analyze these different conflict categories and develop a general pattern of strategies by which the dilemmas might be resolved. The theoretical implications and practical insights of the findings for tourism development, as well as other social conflict contexts, were also investigated.

Online food image detection is a key issue for intelligent food materials receiving and food supply chain applications, how to efficiently, accurately and quickly detect the image of food materials is a challenging research topic. A fast auto-clean convolutional neural network (CNN) model for online prediction of food materials is proposed, which is aiming at problems of the complex characteristics of the food images such as the complexity of the food materials, the focus of the dislocation and the uniformity of illumination. Firstly, a new approach of the auto-clean CNN models is proposed for automatic image cleaning and classification, which starting from original images and ending with multi-class prediction of clean images. Given a vocabulary of K classes, and a Yes/No clean label, two CNN models will learn a class label and a clean label respectively. Secondly, after the forward pass of two CNN models, the joint features generated from the last convolutional layers will be fed into our two loss layers. Combined with multi-class classification method, it classifies and optimizes the image dataset intelligently. Finally, an online prediction algorithm is proposed to improve the image recognition efficiency. Experimental results show that the proposed model and algorithm have good efficiency and accuracy, and the results of this study have significance to optimize the efficiency of the food supply chain industry and food quality evaluation.

Tourism as an emotional sphere, researchers' efforts on emotions lag behind the fruitful achievements of psychology, in both methods and theories. Tourism studies on emotion mostly rely on self-reports only, thus limiting the understanding to explicitly expressed emotions. This study aims to compare residents' emotional responses toward tourists expressed implicitly (through facial expressions) and explicitly (through self-reports), and interpret identified discrepancies by exploring the psychological mechanism behind the two expression channels. Using self-developed video vignettes as triggers, Hong Kong residents’ facial expressions during watching and self-reported emotions after watching the videos were recorded. Through a comprehensive comparison, desires-derived and stereotypes-elicited emotional responses of residents toward tourists were distinguished. Facial expressions conveyed more desires-derived emotions like happiness, sadness, and anger, whereas self-reports emphasized stereotypes-elicited emotions, particularly disgust. A dual-process model of emotion formation was proposed to interpret the emotional expressive discrepancies, thereby enhancing the theorization of tourism studies on emotion.

A novel and ultrasensitive electrochemiluminescent (ECL) bioassay has been developed for the detection of atrazine (ATZ), whereby bifunctional S, N-codoped carbon dots (S, N-CDs) and activated mesoporous bicarbons (BCs) have been innovatively integrated to synergistically amplify the ECL signal. When endogenous dissolved O2 is used as a coreactant, its sluggish reduction hinders the enhancement of ECL intensity of the luminophore, thus restricting its further application in bioanalysis. Here, bifunctional S, N-CDs severe as not only the ECL luminophore but the coreaction accelerator of dissolved O2 to generate more intermediates to boost the coreaction without using any other coreactant and coreaction accelerator. The as-formed nanoarchitectures of BCs possess enlarged surface area as the nanocarriers. They could provide adequate active sites for immobilization of tyrosinase (Tyr), which greatly prompts the ECL bioassay applications. Such a smart integration of bifunctional S, N-CDs, activated mesoporous BCs and the enzyme inhibition reaction achieves a unique and attractive high-performance signal-on ECL bioassay, realizing ultrasensitive detection of ATZ. Under the optimal condition, this bioassay exhibits two linear ranges, from 0.0001 to 0.01 μg L−1 and 0.01–20 μg L−1 with a detection limit of 0.08 ng L−1 at signal to noise ratio of 3. The as-fabricated assay is sensitive and economical, opening a new way for the enhancement of ECL signal output and a versatile strategy for ultrasensitive ECL bioanalysis.

Trimethlyamine-N-oxide (TMAO) was recently identified as a promoter of atherosclerosis. Patients with CKD exhibit accelerated development of atherosclerosis; however, no studies have explored the relationship between TMAO and atherosclerosis formation in this group. This study measured serum concentrations and urinary excretion of TMAO in a CKD cohort (n=104), identified the effect of renal transplant on serum TMAO concentration in a subset of these patients (n=6), and explored the cross-sectional relationship between serum TMAO and coronary atherosclerosis burden in a separate CKD cohort (n=220) undergoing coronary angiography. Additional exploratory analyses examined the relationship between baseline serum TMAO and long-term survival after coronary angiography. Serum TMAO concentrations demonstrated a strong inverse association with eGFR (r(2)=0.31, P

Fibroblast growth factor 23 (FGF23) is secreted primarily by osteocytes and regulates phosphate and vitamin D metabolism. Elevated levels of FGF23 are clinically associated with endothelial dysfunction and arterial stiffness in chronic kidney disease (CKD) patients; however, the direct effects of FGF23 on endothelial function are unknown. We hypothesized that FGF23 directly impairs endothelial vasorelaxation by hindering nitric oxide (NO) bioavailability. We detected expression of all four subtypes of FGF receptors ( Fgfr1–4) in male mouse aortas. Exogenous FGF23 (90–9,000 pg/ml) did not induce contraction of aortic rings and did not relax rings precontracted with PGF2α. However, preincubation with FGF23 (9,000 pg/ml) caused a ∼36% inhibition of endothelium-dependent relaxation elicited by acetylcholine (ACh) in precontracted aortic rings, which was prevented by the FGFR antagonist PD166866 (50 nM). Furthermore, in FGF23-pretreated (9,000 pg/ml) aortic rings, we found reductions in NO levels. We also investigated an animal model of CKD ( Col4a3 −/− mice) that displays highly elevated serum FGF23 levels and found they had impaired endothelium-dependent vascular relaxation and reduced nitrate production compared with age-matched wild types. To elucidate a mechanism for the FGF23-induced impairment, we measured superoxide levels in endothelial cells and aortic rings and found that they were increased following FGF23 treatment. Crucially, treatment with the superoxide scavenger tiron reduced superoxide levels and also restored aortic relaxation to ACh. Therefore, our data suggest that FGF23 increases superoxide, inhibits NO bioavailability, and causes endothelial dysfunction in mouse aorta. Together, these data provide evidence that high levels of FGF23 contribute to cardiovascular dysfunction.

Fibroblast growth factor 23 (FGF23) is a phosphaturic hormone that in end-stage renal disease is markedly increased in serum; however, the mechanisms responsible for this increase are unclear. Here, we tested whether phosphate retention in chronic kidney disease (CKD) is responsible for the elevation of FGF23 in serum using Col4α3 knockout mice, a murine model of Alport disease exhibiting CKD. We found a significant elevation in serum FGF23 in progressively azotemic 8- and 12-week-old CKD mice along with an increased fractional excretion of phosphorus. Both moderate and severe phosphate restriction reduced fractional excretion of phosphorus by 8 weeks, yet serum FGF23 levels remained strikingly elevated. By 12 weeks, FGF23 levels were further increased with moderate phosphate restriction, while severe phosphate restriction led to severe bone mineralization defects and decreased FGF23 production in bone. CKD mice on a control diet had low serum 1,25-dihydroxyvitamin D (1,25(OH) 2 D) levels and 3-fold higher renal Cyp24α1 gene expression compared to wild-type mice. Severe phosphate restriction increased 1,25(OH) 2 D levels in CKD mice by 8 weeks and lowered renal Cyp24α1 gene expression despite persistently elevated serum FGF23. Renal klotho gene expression declined in CKD mice on a control diet, but improved with severe phosphate restriction. Thus, dietary phosphate restriction reduces the fractional excretion of phosphorus independent of serum FGF23 levels in mice with CKD.

PKD1 (polycystin-1), the disease-causing gene for ADPKD, is widely expressed in various cell types, including osteoblasts, where its function is unknown. Although global inactivation of Pkd1 in mice results in abnormal skeletal development, the presence of polycystic kidneys and perinatal lethality confound ascertaining the direct osteoblastic functions of PKD1 in adult bone. To determine the role of PKD1 in osteoblasts, we conditionally inactivated Pkd1 in postnatal mature osteoblasts by crossing Oc (osteocalcin)-Cre mice with floxed Pkd1 (Pkd1(flox/m1Bei)) mice to generate conditional heterozygous (Oc-Cre;Pkd1(flox/+)) and homozygous (Oc-Cre;Pkd1(flox/m1Bei)) Pkd1-deficient mice. Cre-mediated recombination (Pkd1(Delta flox)) occurred exclusively in bone. Compared with control mice, the conditional deletion of Pkd1 from osteoblasts resulted in a gene dose-dependent reduction in bone mineral density, trabecular bone volume, and cortical thickness. In addition, mineral apposition rates and osteoblast-related gene expression, including Runx2-II (Runt-related transcription factor 2), osteocalcin, osteopontin, and bone sialoprotein, were reduced proportionate to the reduction of Pkd1 gene dose in bone of Oc-Cre;Pkd1(flox/+) and Oc-Cre;Pkd1(flox/m1Bei) mice. Primary osteoblasts derived from Oc-Cre;Pkd1(flox/m1Bei) displayed impaired differentiation and suppressed activity of the phosphatidylinositol 3-kinase-Akt-GSK3beta-beta-catenin signaling pathways. The conditional deletion of Pkd1 also resulted in increased adipogenesis in bone marrow and in osteoblast cultures. Thus, PKD1 directly functions in osteoblasts to regulate bone formation.

Polycystin-1 (PC1) may play an important role in skeletogenesis through regulation of the bone-specific transcription factor Runx2-II. In the current study we found that PC1 co-localizes with the calcium channel polycystin-2 (PC2) in primary cilia of MC3T3-E1 osteoblasts. To establish the role of Runx2-II in mediating PC1 effects on bone, we crossed heterozygous Pkd1m1Bei and Runx2-II mice to create double heterozygous mice (Pkd1+/m1Bei/Runx2-II+/-) deficient in both PC1 and Runx2-II. Pkd1+/m1Bei/Runx2-II+/- mice exhibited additive reductions in Runx2-II expression that was associated with impaired endochondral bone development, defective osteoblast-mediated bone formation, and osteopenia. In addition, we found that basal intracellular calcium levels were reduced in homozygous Pkd1m1Bei osteoblasts. In contrast, overexpression of a PC1 C-tail construct increased intracellular calcium and selectively stimulated Runx2-II P1 promoter activity in osteoblasts through a calcium-dependent mechanism. Site-directed mutagenesis of critical amino acids in the coiled-coil domain of PC1 required for coupling to PC2 abolished PC1-mediated Runx2-II P1 promoter activity. Additional promoter analysis mapped the PC1-responsive region to the “osteoblast-specific” enhancer element between -420 and -350 bp that contains NFI and AP-1 binding sites. Chromatin immunoprecipitation assays confirmed the calcium-dependent binding of NFI to this region. These findings indicate that PC1 regulates osteoblast function through intracellular calcium-dependent control of Runx2-II expression. The overall function of the primary cilium-polycystin complex may be to sense and transduce environmental clues into signals regulating osteoblast differentiation and bone development.

Background and objectives Elevated concentrations of fibroblast growth factor 23 (FGF23) are postulated to promote 25-hydroxyvitamin D (25[OH]D) insufficiency in CKD by stimulating 24-hydroxylation of this metabolite, leading to its subsequent degradation; however, prospective human studies testing this relationship are lacking. Design, setting, participants, & measurements An open-label prospective study was conducted from October 2010 through July 2012 to compare the effect of 8 weeks of oral cholecalciferol therapy (50,000 IU twice weekly) on the production of 24,25(OH) 2 D 3 in vitamin D–insufficient patients with CKD ( n =15) and controls with normal kidney function ( n =15). Vitamin D metabolites were comprehensively profiled at baseline and after treatment, along with FGF23 and other mineral metabolism parameters. Results Vitamin D 3 and 25(OH)D 3 concentrations increased equivalently in the CKD and control groups following cholecalciferol treatment (median D 3 change, 8.6 ng/ml [interquartile range, 3.9–25.6 ng/ml] for controls versus 12.6 ng/ml [6.9–41.2 ng/ml] for CKD [ P =0.15]; 25(OH)D 3 change, 39.2 ng/ml [30.9–47.2 ng/ml] for controls versus 39.9 ng/ml [31.5–44.1 ng/ml] for CKD [ P =0.58]). Likewise, the absolute increase in 1 α ,25(OH) 2 D 3 was similar between CKD participants and controls (change, 111.2 pg/ml [64.3–141.6 pg/ml] for controls versus 101.1 pg/ml [74.2–123.1 pg/ml] for CKD; P =0.38). Baseline and post-treatment 24,25(OH) 2 D 3 concentrations were lower in the CKD group; moreover, the absolute increase in 24,25(OH) 2 D 3 after therapy was markedly smaller in patients with CKD (change, 2.8 ng/ml [2.3–3.5 ng/ml] for controls versus 1.2 ng/ml [0.6–1.9 ng/ml] for patients with CKD; P 2 D 3 for individuals with CKD; this association was negated after adjustment for eGFR by multivariate analysis. Conclusions Patients with CKD exhibit an altered ability to increase serum 24,25(OH) 2 D 3 after cholecalciferol therapy, suggesting decreased 24-hydroxylase activity in CKD. The observed relationship between baseline FGF23 and increments in 24,25(OH) 2 D 3 further refutes the idea that FGF23 directly contributes to 25(OH)D insufficiency in CKD through stimulation of 24-hydroxylase activity.

We examined the osteoblast/osteocyte expression and function of polycystin-1 (PC1), a transmembrane protein that is a component of the polycystin-2 (PC2)-ciliary mechano-sensor complex in renal epithelial cells. We found that MC3T3-E1 osteoblasts and MLO-Y4 osteocytes express transcripts for PC1, PC2, and the ciliary proteins Tg737 and Kif3a. Immunohistochemical analysis detected cilia-like structures in MC3T3-E1 osteoblastic and MLO-Y4 osteocyte-like cell lines as well as primary osteocytes and osteoblasts from calvaria. Pkd1m1Bei mice have inactivating missense mutations of Pkd1 gene that encode PC1. Pkd1m1Bei homozygous mutant mice demonstrated delayed endochondral and intramembranous bone formation, whereas heterozygous Pkd1m1Bei mutant mice had osteopenia caused by reduced osteoblastic function. Heterozygous and homozygous Pkd1m1Bei mutant mice displayed a gene dose-dependent decrease in the expression of Runx2 and osteoblast-related genes. In addition, overexpression of constitutively active PC1 C-terminal constructs in MC3T3-E1 osteoblasts resulted in an increase in Runx2 P1 promoter activity and endogenous Runx2 expression as well as an increase in osteoblast differentiation markers. Conversely, osteoblasts derived from Pkd1m1Bei homozygous mutant mice had significant reductions in endogenous Runx2 expression, osteoblastic markers, and differentiation capacity ex vivo. Co-expression of constitutively active PC1 C-terminal construct into Pkd1m1Bei homozygous osteoblasts was sufficient to normalize Runx2 P1 promoter activity. These findings are consistent with a possible functional role of cilia and PC1 in anabolic signaling in osteoblasts/osteocytes.

A simple and sensitive method was developed for determining ivermectin in sheep serum. The sample is cleaned up on an immunoaffinity column and determined by liquid chromatography with detection at 245 nm. Recoveries ranged from 90.3 to 98.8% (93.9 ± 4.3%) for samples fortified with 2.0–50 ng ivermectin/mL. Coefficients of variation were 3.2–11.0%. The limit of detection was 1 ng/mL in 5.0 mL serum.

To reduce the frequency of administration of tamoxifen citrate so as to improve its bioavailability and patients' compliance.HPMC(K4M) was employed as major retarded-release controller. The wetting granulation and directly compressing method was used to produce the sustained release tablet. Then the in vitro release profile was applied as main criteria to evaluate six formulations according to the variation of HPMC(K4M) amount. The concentration of tamoxifen citrate was measured by UV spectrometry. Finally the releasing characteristics of sustained release and conventional tablets were compared to clarify the sustained effect of the former.At 278 nm there was no interaction between tamoxifen citrate and the recipients so that it was adopted as the wavelength of determination. The recovery efficiency of this method ranged from 95%-105%. The final formulation could release 86.40% of its loading amount in 12 h and its releasing profile fitted the Zero-order equation well. The percentages of accumulative release in 1 h were 76.81% and 7.08% for sustained release tablet and conventional tablet respectively.The sustained release tablet of tamoxifen citrate could demonstrate a continuous and stable releasing profile and last for over 12 h. It has significant retarded effect in comparison with the conventional one and could be a new choice of regimen in its clinical application.

Runx2 transcribes Runx2-II and Runx2-I isoforms with distinct N-termini. Deletion of both isoforms results in complete arrest of bone development, whereas selective loss of Runx2-II is sufficient to form a grossly intact skeleton with impaired endochondral bone development. To elucidate the role of Runx2-II in osteoblast function in adult mice, we examined heterozygous Runx2-II (Runx2-II(+/-)) and homozygous Runx2-II (Runx2-II(-/-))-deficient mice, which, respectively, lack one or both copies of Runx2-II but intact Runx2-I expression. Compared to wild-type mice, 6-week-old Runx2-II(+/-) had reduced trabecular bone volume (BV/TV%), cortical thickness (Ct.Th), and bone mineral density (BMD), decreased osteoblastic and osteoclastic markers, lower bone formation rates, impaired osteoblast maturation of BMSCs in vitro, and significant reductions in mechanical properties. Homozygous Runx2-II(-/-) mice had a more severe reduction in BMD, BV/TV%, and Ct.Th, and greater suppression of osteoblastic and osteoclastic markers than Runx2-II(+/-) mice. Non-selective Runx2(+/-) mice, which have an equivalent reduction in Runx2 expression due to the lack one copy of Runx2-I and II, however, had an intermediate reduction in BMD. Thus, selective Runx2-II mutation causes diminished osteoblastic function in an adult mouse leading to low-turnover osteopenia and suggest that Runx2-I and II have distinct functions imparted by their different N-termini.