A novel heterozygous variant of the SALL1 gene with atypical Townes-Brocks syndrome phenotypes in Chinese family

Townes-Brocks syndrome (TBS) is an autosomal dominant disorder characterised by the triad of anorectal, thumb, and ear malformations. It may also be accompanied by defects in kidney, heart, eyes, hearing, and feet. TBS has been demonstrated to result from heterozygous variants in the SALL1 gene, which encodes zinc finger protein believed to function as a transcriptional repressor. The clinical characteristics of an atypical TBS phenotype patient from a Chinese family are described, with predominant manifestations including external ear dysplasia, unilateral renal hypoplasia with mild renal dysfunction, and hearing impairment. A novel heterozygous variant c.3060T>A (p.Tyr1020*) in exon 2 of the SALL1 gene was identified in this proband. Pyrosequencing of the complementary DNA of the proband revealed that the variant transcript accounted for 48% of the total transcripts in peripheral leukocytes, indicating that this variant transcript has not undergone nonsense-mediated mRNA decay. This variant c.3060T > A is located at the terminal end of exon 2, proximal to the 3' end of the SALL1 gene, and exerts a relatively minor impact on protein function. We suggest that the atypical TBS phenotype observed in the proband may be attributed to the truncated protein retaining partial SALL1 function.

Clinical characteristics, outcomes and risk factors for mortality in hospitalized diabetes and chronic kidney disease patients after COVID-19 infection following widespread vaccination

BACKGROUND

COVID-19 poses a significant threat to patients with comorbidities, such as diabetes and chronic kidney disease (CKD). China experienced a nationwide COVID-19 endemic from December 2022 to January 2023, which is the first occurrence of such an outbreak following China's widespread administration of COVID-19 vaccinations.

METHODS

A total of 338 patients with diabetes and CKD combined with COVID-19 infection between December 7, 2022 and January 31, 2023 were included in this study. The end follow-up date was February 10, 2023. Univariate analysis and multivariate Cox analysis were used to analyze risk factors for death.

RESULTS

During the 50-day median follow-up period, 90 patients in the study cohort died, for a mortality rate of 26.63%. The median age of the study cohort was 74 years, with a male predominance of 74%. During hospitalization, 21% of patients had incident AKI, 17% of patients experienced stroke, and 40% of patients experienced respiratory failure. Cox proportional hazard regression showed that older age, a diagnosis of severe or critically severe COVID-19 infection, incident AKI and respiratory failure, higher level of average values of fasting glucose during hospitalization, UA, and total bilirubin were independent risk factors for death in our multivariate model.

CONCLUSIONS

These findings highlight the critical importance of identifying and managing comorbid risk factors for COVID-19, especially among the elderly, in order to optimize clinical outcomes, even after COVID-19 vaccination.

Three exonic variants in the COL4A5 gene alter RNA splicing in a minigene assay

BACKGROUND

X-linked Alport syndrome (XLAS) is an inherited renal disease caused by rare variants of COL4A5 on chromosome Xq22. Many studies have indicated that single nucleotide variants (SNVs) in exons can disrupt normal splicing process of the pre-mRNA by altering various splicing regulatory signals. The male patients with XLAS have a strong genotype-phenotype correlation. Confirming the effect of variants on splicing can help to predict kidney prognosis. This study aimed to investigate whether single nucleotide substitutions, located within three bases at the 5' end of the exons or internal position of the exons in COL4A5 gene, cause aberrant splicing process.

METHODS

We analyzed 401 SNVs previously presumed missense and nonsense variants in COL4A5 gene by bioinformatics programs and identified candidate variants that may affect the splicing of pre-mRNA via minigene assays.

RESULTS

Our study indicated three of eight candidate variants induced complete or partial exon skipping. Variants c.2678G>C and c.2918G>A probably disturb classic splice sites leading to corresponding exon skipping. Variant c.3700C>T may disrupt splicing enhancer motifs accompanying with generation of splicing silencer sequences resulting in the skipping of exon 41.

CONCLUSION

Our study revealed that two missense variants positioned the first nucleotides of the 5' end of COL4A5 exons and one internal exonic nonsense variant caused aberrant splicing. Importantly, this study emphasized the necessity of assessing the effects of SNVs at the mRNA level.

Hybrid-Supervised Deep Learning for Proton-Acoustic Reconstruction for 3D In Vivo Proton Dose Verification

PURPOSE/OBJECTIVE(S)

Proton-acoustic (PA) image has shown great potential to provide real-time 3D dose verification of proton therapy. However, the PA image quality suffers from severe limited view artifacts, which significantly impairs its accuracy for dose verification. In this study, we developed a hybrid-supervised deep learning method for PA reconstruction to address the limited-view issues.

MATERIALS/METHODS

Our method consists of two stages. In the first stage, a transformer-based network was proposed to reconstruct initial pressure maps from protoacoustic signals. The network was first trained using supervision by the iteratively reconstructed pressure map and then fine-tuned using transfer learning and self-supervision based on the data fidelity constraint. In the second stage, the PA image was further enhanced by a 3D U-net. The final PA images were converted to dose maps using conversion coefficients derived from CT images. Data from 126 prostate cancer patients treated by proton therapy were collected under an IRB protocol and were split into 86 and 40 patients for model training and testing, respectively. Data of each patient contains the planning CT scan, the corresponding clinical treatment plan, and the dose map calculated by commercial software. The radiofrequency signals were generated by performing proton acoustic simulation based on CT images and the ground truth pressure map derived from the treatment plan. An ultrasound detector matrix with 64 × 64 size and 500kHz central frequency was simulated under the perineum to acquire the signals in the prostate area. In the testing results, the method's accuracy was evaluated using Root-mean-squared-error (RMSE) and structural-similarity-index-measure (SSIM) between the reconstructed and ground truth pressure map and dose distribution.

RESULTS

Testing results showed that the reconstructed pressure map achieved an average RMSE/SSIM of 0.0292/0.96, demonstrating excellent 3D information with details. Dose maps derived from the pressure map achieved an average RMSE/SSIM of 0.018/0.99 with a gamma index of 94.7% and 95.7% for 1%/3 mm and 1%/5 mm criteria compared to the ground truth dose maps. The reconstruction time was 6s, which can be further reduced using GPU.

CONCLUSION

Our study achieves start-of-the-art performance in the challenging task of direct reconstruction from limited-view radiofrequency signals, demonstrating the great promise of PA imaging as a highly efficient and accurate tool for in-vivo 3D proton dose verification. Such high-precision 3D online dose verification can substantially reduce the range uncertainties of proton therapy to significantly improve its precision and outcomes.

Minigene splicing assays reveal new insights into exonic variants of the SLC12A3 gene in Gitelman syndrome

BACKGROUND

Gitelman syndrome (GS) is a type of salt-losing tubular disease, most of which is caused by SLC12A3 gene variants, and missense variants account for the majority. Recently, the phenomenon of exon skipping, in which variants disrupt normal pre-mRNA splicing, has been related to a variety of diseases. Therefore, we hypothesize that a certain proportion of SLC12A3 variants can result in disease via interfering with the normal splicing process.

METHODS

We analyzed 342 previously presumed SLC12A3 missense variants using bioinformatics programs and identified candidate variants that may alter the splicing of pre-mRNA through minigene assays.

RESULTS

Our study revealed that, among ten candidate variants, six variants (c.602G>A, c.602G>T, c.1667C>T, c.1925G>A, c.2548G>C, and c.2549G>C) led to complete or incomplete exon skipping by affecting exonic splicing regulatory elements and/or disturbing canonical splice sites.

CONCLUSION

It is worth mentioning that this is the largest study on pre-mRNA splicing of SLC12A3 exonic variants. In addition, our study emphasizes the importance of detecting splicing function at the mRNA level in GS and indicates that minigene analysis is a valuable tool for splicing functional assays of variants in vitro.

Four novel variants identified in primary hyperoxaluria and genotypic and phenotypic analysis in 21 Chinese patients

Background: Primary hyperoxaluria (PH) is a rare genetic disorder characterized by excessive accumulation of oxalate in plasma and urine, resulting in various phenotypes due to allelic and clinical heterogeneity. This study aimed to analyze the genotype of 21 Chinese patients with primary hyperoxaluria (PH) and explore their correlations between genotype and phenotype. Methods: Combined with clinical phenotypic and genetic analysis, we identified 21 PH patients from highly suspected Chinese patients. The clinical, biochemical, and genetic data of the 21 patients were subsequently reviewed. Results: We reported 21 cases of PH in China, including 12 cases of PH1, 3 cases of PH2 and 6 cases of PH3, and identified 2 novel variants (c.632T > G and c.823_824del) in AGXT gene and 2 novel variants (c.258_272del and c.866-34_866-8del) in GRHPR gene, respectively. A possible PH3 hotspot variant c.769T > G was identified for the first time. In addition, patients with PH1 showed higher levels of creatinine and lower eGFR than those with PH2 and PH3. In PH1, patients with severe variants in both alleles had significantly higher creatinine and lower eGFR than other patients. Delayed diagnosis still existed in some late-onset patients. Of all cases, 6 had reached to end-stage kidney disease (ESKD) at diagnosis with systemic oxalosis. Five patients were on dialysis and three had undergone kidney or liver transplants. Notably, four patients showed a favorable therapeutic response to vitamin B6, and c.823_824dup and c.145A > C may be identified as potentially vitamin B6-sensitive genotypes. Conclusion: In brief, our study identified 4 novel variants and extended the variant spectrum of PH in the Chinese population. The clinical phenotype was characterized by large heterogeneity, which may be determined by genotype and a variety of other factors. We first reported two variants that may be sensitive to vitamin B6 therapy in Chinese population, providing valuable references for clinical treatment. In addition, early screening and prognosis of PH should be given more attention. We propose to establish a large-scale registration system for rare genetic diseases in China and call for more attention on rare kidney genetic diseases.

Identification of two novel variants of BCS1L gene in a patient with classical GRACILE syndrome

BCS1L pathogenic variants cause widely different clinical phenotypes. Disease phenotypes can be as mild as Björnstad syndrome, characterized by pili torti (abnormal flat twisted hair shafts) and sensorineural hearing loss, or as severe as GRACILE syndrome, characterized by growth restriction, aminoaciduria, cholestasis, iron overload, lactic acidosis, and early death. BCS1L pathogenic variants are also linked to an undefined complex III deficiency, a heterogeneous condition generally involving renal and hepatic pathologies, hypotonia, and developmental delays. So far, all patients with GRACILE syndrome carry a homozygous p.Ser78Gly variant in BCS1L gene by reviewing articles. A 24-day-old boy presented with typical clinical phenotype of GRACILE syndrome. The Whole Exome Sequencing confirmed that the patient had a missense variant (c.245C>T, p.Ser82Leu) and a small deletion (c.231_232delCA, p. Ser78Cysfs*9) in BCS1L gene inherited from his father and mother separately, he died at 5 months of age. We reported a patient with GRACILE syndrome and identified two novel variants in BCS1L gene. Our study expands the mutational spectrum of BCS1L gene associated with GRACILE syndrome and will be beneficial for genetic diagnosis. This article is protected by copyright. All rights reserved.

Preparation and Photo-Oxidation Aging Behavior of Oriented Polylactic Acid

This study employed solid hot stretching technology to produce successfully specifically oriented polylactic acid (PLA) while investigating the impact of orientation structure on its photo-oxidation aging properties. After orientation, the molecular weight and mechanical properties retention rate of PLA were improved, and the crystallinity (Xc) increased in conjunction with prolonged aging time, while the molecular orientation failed to modify the mechanism responsible for PLA deterioration. Furthermore, an examination regarding the way in which the photo-oxidation stability of PLA was enhanced, demonstrated that the increased Xc and structural orientation were beneficial for delaying the photo-oxidation aging of PLA.

High cyclic tensile stress disrupts the extracellular matrix in human chondrocyte by F-actin cytoskeletal polymerization and reactive oxygen species production

This study aims to explore the mechanism of cyclic tensile stress (CTS) on human chondrocytes (CHs) relating to the reactive oxygen species (ROS) generation and extracellular matrix (ECM) stability in vitro. A well-established CTS model with 5%, 10%, or 20% elongation was performed for CHs stretching. After CTS, the cell viability, total ROS level, main ECM components, matrix metalloproteinase (MMP), tissue inhibitor of metalloproteinase (TIMP), F-actin density, and some anti-oxidative enzymes were analyzed. Additionally, the antioxidant N-acetylcysteine (NAC) and cytochalasin D were used to suppress the ROS production and F-actin polymerization when the CHs underwent CTS, respectively. The treatment of 20% elongation-CST significantly decreased the CH viability and the expressions of collagen II, aggrecan, anti-oxidative enzymes and TIMP3/4, however, it increased the ROS accumulation, F-actin polymerization, and the expression of collagen I and MMP3/13. In contrast, the application of NAC and cytochalasin D could partly rescue the CHs from the injury caused by the high CTS. Therefore, high CTS disrupts the ECM by remodeling the F-actin cytoskeleton and promoting ROS production. Cytochalasin D and NAC are effective in rejecting F-actin cytoskeleton polymerization, and ROS accumulation through a potential synergetic process, which alleviates the ECM injury caused by High CTS.

Identification of seven exonic variants in the SLC4A1, ATP6V1B1, and ATP6V0A4 genes that alter RNA splicing by minigene assay

Primary distal renal tubular acidosis (dRTA) is a rare tubular disease associated with variants in SLC4A1, ATP6V0A4, ATP6V1B1, FOXⅠ1, or WDR72 genes. Currently, there is growing evidence that all types of exonic variants can alter splicing regulatory elements, affecting the precursor messenger RNA (pre-mRNA) splicing process. This study was to determine the consequences of variants associated with dRTA on pre-mRNA splicing combined with predictive bioinformatics tools and minigene assay. As a result, among the 15 candidate variants, 7 variants distributed in SLC4A1 (c.1765C>T, p.Arg589Cys), ATP6V1B1 (c.368G>T, p.Gly123Val; c.370C>T, p.Arg124Trp; c.484G>T, p.Glu162* and c.1102G>A, p.Glu368Lys) and ATP6V0A4 genes (c.322C>T, p.Gln108* and c.1572G>A, p.Pro524Pro) were identified to result in complete or incomplete exon skipping by either disruption of exonic splicing enhancers (ESEs) and generation of exonic splicing silencers, or interference with the recognition of the classic splicing site, or both. To our knowledge, this is the first study on pre-mRNA splicing of exonic variants in the dRTA-related genes. These results highlight the importance of assessing the effects of exonic variants at the mRNA level and suggest that minigene analysis is an effective tool for evaluating the effects of splicing on variants in vitro.

Genotypic and phenotypic analysis in 51 Chinese patients with primary distal renal tubular acidosis

The aim of this study was to analyze the genetic variants of 51 Chinese patients with distal renal tubular acidosis (dRTA) and explore the correlation between their genotype and phenotype. Eight variants of SLC4A1, 19 variants of ATP6V0A4, and 16 variants of ATP6V1B1 have been identified, and of which 14 were novel ones. Eleven patients with autosomal dominant dRTA, and four patients with autosomal recessive dRTA were caused by genetic defects in SLC4A1; 18 and nine patients with recessive dRTA were resulted by defects in ATP6V0A4 and ATP6V1B1 respectively; no causal gene was identified in seven patients. Mutation frequency of SLC4A1 in Chinese populations was more common than Europeans. The incidence of deafness in ATP6V0A4 and ATP6V1B1 groups was 16.7% and 54.5%, respectively. The frequency of CKD in adults, children and infants was 100%, 51%, and 3%, separately. Our study will further expand the mutation spectrum of primary dRTA and provide valuable references to genetic counseling of Chinese populations.

Sudden onset of nephrotic syndrome in an asymptomatic Fabry patient: a case report

Background

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by the mutation of the GLA gene, encoding the α-galactosidase, which is responsible for the catabolism of neutral glycosphingolipids. Microalbuminuria or low-grade proteinuria, and continuously progressive renal failure are common manifestations in FD males. However, sudden onset of nephrotic syndrome in FD, is rarely reported.

Case report

A 32-year-old Chinese man was admitted to our hospital because of sudden onset of generalized edema due to nephrotic syndrome. He denied hypohidrosis, nocturia, and any history of episodic hand or foot pain. A few scattered angiokeratoma can be found on the low back skin on examination. Except for the similar locating pattern of angiokeratoma, no evident abnormality was found in the laboratory work up and physical examination of his younger brother. The patient was diagnosed with FD companying with minimal change disease by renal biopsy. Genetic analysis on our patient and his sibling revealed a nonsense GLA gene variant (c.707G > A, p.Trp236*), which has been previously reported in FD. Immunotherapy alone (steroids and tacrolimus), but without enzyme replacement therapy, much improved the massive proteinuria. Follow up to date, his 24-h urine protein is stable at about 0.5 g, and renal function keeps normal.

Conclusion

Sudden onset of nephrotic syndrome, although rare, may occur in FD, even as the primary renal manifestation, but this usually suggests additional renal disease. Immunosuppressive treatment should be considered in such FD patient companying with nephrotic syndrome.

Adoptive transfer of immunomodulatory M2 macrophages suppresses experimental autoimmune encephalomyelitis in C57BL/6 mice via blockading NF-κB pathway

Macrophages play important roles in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), and M2 macrophage may have anti-inflammatory effects. In this study, we elucidated the roles of M1 and M2 macrophages in the pathogenesis of EAE and the effects of treatment with M2 macrophages that target certain proinflammatory cytokines and with immunomodulatory preparations that beneficially influence the disease course. We found macrophages increased at the onset of clinical signs in the EAE group, consistent with an increased proportion of M1 macrophages and low numbers of M2 macrophages. As the disease progressed and the symptoms worsened, M1 macrophages decreased and M2 macrophages gradually increased until the peak. In the recovery stage, M2 macrophages gradually decreased. Treatment with M2 macrophages inhibited the nuclear factor kappa B (NF-κB) pathway, alleviated the symptoms of EAE, reduced inflammatory cell infiltration and demyelination in the central nervous system and decreased the numbers of macrophages in the spleens. BAY-11-7082, an NF-κB blocking agent, could reduce the total number of macrophages both in vivo and in vitro, effectively prevented EAE development and significantly inhibited EAE symptoms in mice. Our study demonstrates that macrophages may play a crucial role in the pathogenesis of EAE, while M2 macrophages have anti-inflammatory effects. Transfer of M2 macrophages to EAE mice can block the NF-κB pathway successfully and relieve EAE symptoms. Application of NF-κB blockers is useful in the prevention and treatment of EAE.

Eight novel KCNJ1 variants and parathyroid hormone overaction or resistance in 5 probands with Bartter syndrome type 2

PURPOSE

Bartter syndrome type 2 (BS2) is an autosomal recessive renal tubular disorder, which is caused by the mutations in KCNJ1. This study was designed to analyze and describe the genotype and clinical features of five Chinese probands with BS2.

METHODS

Identify KCNJ1 gene variants by the next generation sequencing and evaluate their mutation effects according to 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines.

RESULTS

Ten variants including eight novel ones of KCNJ1 gene were found, the most common type was missense variant. The common symptoms and signs from high to low incidence were: polydipsia and polyuria (5/5), one of them (1/5) presented with diabetes insipidus; maternal polyhydramnios and premature delivery (4/5); growth retardation (3/5). Two patients presented with hypochloremic metabolic alkalosis and hypokalemia; whereas the acid-base disturbance was absent in the others. One patient had evident parathyroid hormone (PTH) resistance (hypocalcemia, hyperphosphatemia and markedly elevated PTH levels), three presented with PTH overacting (hypercalcemia, hypophosphatemia and mild elevated PTH levels), and one showed normal blood calcium and phosphorus concentrations with high-normal PTH levels. All patients had nephrocalcinosis and/or hypercalciuria, and one of them complicated with nephrolithiasis. Indomethacin has significant therapeutic effect on the growth retardation, polydipsia and polyuria and treatment was associated with a decrease in urine calcium excretion, normalization of electrolyte disturbance and PTH parameters.

CONCLUSIONS

Ten variants of KCNJ1 gene were identified in five Chinese probands. These patients had atypical BS phenotype lacking evident metabolic alkalosis and/or manifesting with PTH overaction/resistance, which reminds clinicians to carefully differentiate BS2 with other parathyroid disorders. This is the first report of BS2 from Chinese populations.

Thirteen novel CLCNKB variants and genotype/phenotype association study in 42 Chinese patients with Bartter syndrome type 3

PURPOSE

Analyze the genotype of 42 Chinese patients with Bartter syndrome type 3 (BS3) and investigate their correlation between genotype and phenotype.

METHODS

Identify CLCNKB gene variants by the next-generation sequencing and the multiplex ligation-dependent probe amplification (MLPA), and then evaluate their mutation effects according to 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines.

RESULTS

Thirty-six different variants in CLCNKB gene, including 13 novel ones, were found. The whole gene deletion of CLCNKB gene was the most frequent mutation (40%), and the rate of large deletions is up to 55%. Among 36 variants, six (c.1244T>A, c.1468G>A, c.849_851delCTT, c.359G>T, c.1052G>T, and c.1309G>A) and three (c.228A>C, c.1294_1295TA>CT, and c.1333T>G) variants were classified as "likely pathogenic variants" and "variants with uncertain significance (VUS)," respectively. The other 27 variants were classified as "pathogenic variants". The most common symptoms included: growth retardation (38/42), polydipsia and polyuria (35/42), constipation (31/42), and vomiting (27/42). All patients presented with hypokalemia, hypochloremia, and metabolic alkalosis. The genotype and phenotype association study revealed that who had mutations probably resulting in complete loss of function of both alleles might have severer phenotype. After the treatment that based on indomethacin and potassium chloride, most patients could achieve obvious recovery of growth rate and restoration of hypokalemia.

CONCLUSIONS

The present study have found 36 variants of CLCNKB gene, including 13 novel ones, which enrich the human gene mutation database and provide valuable references to diagnosis, treatment, and the genetic counseling of Chinese population.

Erratum: Avalanches triggered by Kelvin-Helmholtz instability in a cylindrical plasma device [Phys. Rev. E 100, 033212 (2019)]

This corrects the article DOI: 10.1103/PhysRevE.100.033212.

MiR-25 overexpression promotes fracture healing by activating the Wnt signaling pathway

OBJECTIVE

To study the mechanism of micro-ribonucleic acid (miR)-25 in regulating the fracture healing in rats.

MATERIALS AND METHODS

A total of 45 male Sprague-Dawley (SD) rats were selected and randomly divided into group A [Phosphate Buffered Saline (PBS), n=15], group B (mimics NC, n=15) and group C (miR-25 mimics, n=15). The fracture model in rats was established via operation in all groups. From 1 d after the successful modeling, 50 μL (2 nmoL) of PBS was intraperitoneally injected into rats in group A, an equal amount of mimics NC was injected into rats in group B, and an equal amount of miR-25 mimics was injected into rats in group C. The above agents were injected once a week for consecutive 6 weeks. Fracture healing in rats was evaluated via X-ray imaging. At the same time, miR-25 expression in the three groups was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Protein expressions of β-catenin, proliferating cell nuclear antigen (PCNA) and bone morphogenetic protein-2 (BMP-2) in the three groups were detected via Western blotting. The OCN-, PCNA- and BMP-2-positive osteoblasts in the three groups were detected via immunohistochemical staining and were further quantified. Moreover, the biomechanical properties of femoral fracture healing in the three groups were analyzed via the 4-point bending flexural test.

RESULTS

The X-ray examination of the femoral fracture healing at postoperative 1 and 7 weeks revealed that the fracture line disappeared, and both callus formation and fracture healing were good in miR-25 mimics group. In PBS group and mimics NC group, a few fracture lines could be observed, and both callus formation and fracture healing were poor. RT-PCR data showed that the expression level of miR-25 significantly increased in the miR-25 mimics group compared with that in the other two groups, and the differences were statistically significant (p<0.01). Western blotting analyses showed upregulated levels of β-catenin, PCNA and BMP-2 in the miR-25 mimics group compared with those in the control group, and the differences were statistically significant (p<0.01). Immunohistochemical staining manifested that the numbers of OCN-, PCNA- and BMP-2-positive osteoblasts in miR-25 mimics group markedly increased compared with that in the other two groups (p<0.01), suggesting that osteoblast differentiation in miR-25 mimics group was affected. The above immunohistochemical results indicated that the osteoblast differentiation at the fracture end in miR-25 mimics group was markedly enhanced compared with that in control groups. The results of the biomechanical test of femur specimens at 7 weeks after operation showed that in miR-25 mimics group, the maximum load, fracture energy and stiffness increased by 188%, 333% and 90%, respectively, compared with those in the PBS group (p<0.01). It is indicated that miR-25 promoted the mechanical properties of fracture healing.

CONCLUSIONS

The overexpression of miR-25 in the fracture in rats promotes fracture healing by activating the Wnt signaling pathway.

Avalanches triggered by Kelvin-Helmholtz instability in a cylindrical plasma device

A profile-evolving simulation of the Controlled Shear Decorrelation Experiment (CSDX) linear device is performed with our newly developed code. The simulation result shows an excellent agreement with the experimental observations of profiles and fluctuations of plasma density and electric potential in the B=1000 G standard discharges, suggesting the mechanism of their evolutions. According to our simulation, an avalanche of plasma density, featuring a rapid destruction of particle profile, is triggered every time the dominant instability transits from near adiabatic collisional drift wave to non-adiabatic Kelvin-Helmholtz instability. The avalanches always start at the point where the local vorticity is the maximum among the whole device. A critical vorticity is found for any avalanche to happen. The avalanches always lead to intermittent particle and heat convective structures outside the main plasma column, and these structures are ejected out as avaloids when zonal flow intensity at birth time is weak.

Eleven novel SLC12A1 variants and an exonic mutation cause exon skipping in Bartter syndrome type I

INTRODUCTION

Bartter syndrome type I (BS1) has been rarely reported in large groups. On the other hand, the phenomenon of exon skipping, in which exonic mutations result in abnormal splicing, has been reported to be associated with various diseases. Specifically, mutations that result in the disruption of exonic splicing enhancers (ESEs) and/or the creation of exonic splicing silencers (ESSs) can promote exon skipping. However, the aberrant exon skipping caused by an exonic variant in such splicing regulatory elements (SREs) sequences has never been reported in the causal gene of SLC12A1 in BS1.

METHODS

We analyze the variants in nine Chinese families with BS1, including eight with antenatal BS (aBS) and one presenting as classical BS (cBS), by next-generation sequencing. Then we used bioinformatics programs to analyze all these variants found in this study and identify candidate mutations that may induce exon skipping. Furthermore, the effects of identified variants were classified according to the 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines.

RESULTS

Fifteen different variants of SLC12A1 gene were identified, including 11 novel ones. Two of the nine probands were homozygotes, the rest seven ones were compound heterozygotes. One candidate variant (c.1435C>G), not only significantly reduced ESEs scores but also markedly increased ESSs scores, were further investigated by mini-gene splicing assay, and found this single-nucleotide substitution causes abnormal splicing in vitro (exclusion of exon 11). Finally, among 15 variants, 9, 3, and 3 were classified as "pathogenic variants", "likely pathogenic variants", "variants with uncertain significance", respectively.

CONCLUSION

These data would enrich the human gene mutation database (HGMD) and would provide valuable references to the genetic counseling and diagnosis of BS1 for Chinese population. Additionally, our results suggest that aberrant exon skipping is one previously unrecognized mechanism by which an exonic variant in SLC12A1 can lead to BS1.

Novel compound heterozygous ATP6V1B1 mutations in a Chinese child patient with primary distal renal tubular acidosis: a case report

BACKGROUND

Distal renal tubular acidosis (dRTA) is a heterogeneous disorder characterized by normal anion gap metabolic acidosis. Autosomal recessive dRTA is usually caused by mutations occurring in ATP6V1B1 and ATP6V0A4 genes,encoding subunits B1 and a4 of apical H⁺-ATPase, respectively. The heterogeneous clinical manifestations of dRTA have been described in different ethnic groups harboring distinct mutations. Most of the reported cases are from Europe and Africa. At present, the prevalence of primary dRTA is still poorly elucidated in Chinese population.

CASE PRESENTATION

A 2-year and six-month-old female patient was hospitalized because of recurrent hypokalemia, hyperchloremic metabolic acidosis and growth retardation. Laboratory investigations presented a normal anion gap hyperchloremic metabolic acidosis, hypokalemia, and inappropriate alkaline urine. Renal ultrasound indicated bilateral nephrocalcinosis. Bilateral sensorineural hearing loss (SNHL) was confirmed with moderately severe (45 dB) on the left ear and severe (80 dB) on the right ear, which was accompanied with enlarged vestibular aqueduct (EVA) on both sides. According to these findings, a diagnosis of dRTA was made. To identify the pathogenic gene mutation, all coding regions of ATP6V1B1 and ATP6V0A4 gene, including intron-exon boundaries, were analyzed using PCR followed by direct sequence analysis. The splicing variants were verified in peripheral blood leucocytes of the patient by RT-PCR. As a result, two novel heterozygous mutations in ATP6V1B1 were identified in the child. One mutation was a successive 2-nucleotide deletion in exon 2(c.133-134delTG), which caused a marked nonsense mediated mRNA decay. The other was a guanine to adenine substitution of the first nucleotide of intron 8(c.785 + 1 G > A), which led to the exclusion of exon 8. After treatment with sodium citrate, potassium citrateand citric acid, metabolic acidosis and hypokalemia were corrected, but her hearing decreased gradually during the 2 years and had to accept the use of bilateral hearing aids.

CONCLUSIONS

We described two novel dRTA associated mutations in ATP6V1B1 identified in a Chinese child patient accompanying with SNHL and EVA. Our study will help to expand the understanding of this rare disease in Chinese population.

Identification of a novel TSC2 c.3610G > A, p.G1204R mutation contribute to aberrant splicing in a patient with classical tuberous sclerosis complex: a case report

Background

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by hamartomas in any organ systems. Mutations in the TSC1 or TSC2 gene lead to the dysfunction of hamartin or tuberin proteins, which cause tuberous sclerosis complex.

Case presentation

We describe the clinical characteristics of patients from a Chinese family with tuberous sclerosis complex and analyze the functional consequences of their causal genetic mutations. A novel heterozygous mutation (c.3610G > A) at the last nucleotide of exon 29 in TSC2 was identified. On the protein level, this variant was presumed to be a missense mutation (p.Gly1204Arg). However, the splicing assay revealed that this mutation also leads to the whole TSC2 exon 29 skipping, besides the wild-type transcript. The mutated transcript results in an in-frame deletion of 71 amino acids (p.Gly1133_Thr1203del) and its ratio with the normal splice product is of about 44:56.

Conclusions

The novel c.3610G > A TSC2 mutation was identified in association with tuberous sclerosis complex. And it was proven to code both for a missense-carrying transcript (56%), and for an isoform lacking exon 29 (44%).

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0686-6) contains supplementary material, which is available to authorized users.

Familial hypomagnesaemia, Hypercalciuria and Nephrocalcinosis associated with a novel mutation of the highly conserved leucine residue 116 of Claudin 16 in a Chinese patient with a delayed diagnosis: a case report

Background

Sixty mutations of claudin 16 coding gene have been reported in familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) patients. Recent investigations revealed that a highly conserved glycine-leucine-tryptophan (¹¹⁵G-L-W¹¹⁷) motif in the first extracellular segment (ESC1) of claudin 16 might be essential for stabilization of the appropriately folded ECS1 structure and conservation of normal claudin 16 function. However, neither missense nor nonsense mutation has ever been described in this motif. Our study aimed at identifying mutations in a Chinese patient with FHHNC and exploring the association between genotype and phenotype.

Case presentation

A 33-year-old female presented with 4 years history of recurrent acute pyelonephritis without other notable past medical history. Her healthy parents, who aged 56 and 53 respectively, were second cousins, and her only sibling died from renal failure without definite cause at age 25. Renal ultrasound imaging demonstrated atrophic kidneys and bilateral nephrocalcinosis. The laboratory workup revealed impaired renal function (Stage CKD IV), hypocalcemia and mild hypomagnesemia, accompanied with marked renal loss of magnesium and hypercalciuria. During the follow-up, treatment with calcitriol and calcium but not with magnesium was difficult to achieve normal serum calcium levels, whereas her serum magnesium concentration fluctuated within normal ranges. In the end, the patient unavoidably reached ESRD at 36 years old. The clinical features and family history suggested the diagnosis of FHHNC. To make a definite diagnosis, we use whole-exome sequencing to identify the disease-causing mutations and Sanger sequencing to confirm the mutation co-segregation in the family. As a result, a novel homozygous mutation (c.346C > G, p.Leu116Val) in ¹¹⁵G-L-W¹¹⁷ motif of claudin 16 was identified. Her parents, grandmother and one of her cousins carried heterozygous p.Leu116Val, whereas 200 unrelated controls did not carry this mutation.

Conclusions

We described a delayed diagnosis patient with FHHNC in the Chinese population and identified a novel missense mutation in the highly conserved ¹¹⁵G-L-W¹¹⁷ motif of claudin 16 for the first time. According to the reported data and the information deduced from 3D modeling, we speculate that this mutation probably reserve partial residual function which might be related to the slight phenotype of the patient.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0979-1) contains supplementary material, which is available to authorized users.

A novel mutation in exon 9 of Cullin 3 gene contributes to aberrant splicing in pseudohypoaldosteronism type II

Pseudohypoaldosteronism type II (PHAII) is a rare renal tubular disease that is inherited in an autosomal dominant manner. Mutations in four genes (WNK1,WNK4,CUL3, and KLHL3) have been identified to be responsible for this disease. Cullin 3 (CUL3) and KLHL3 are subunits of Cullin–RING E3 ubiquitin ligase complexes, and the serine–threonine kinases WNK1 and WNK4 are substrates of this ubiquitin ligase. For CUL3, all mutations associated with PHAII exclusively lead to exon 9 skipping. In this study, we identified a Chinese PHAII kindred caused by a novel synonymous mutation (c.1221A > G p.Glu407Glu) in CUL3, and explored its effects on exon 9 abnormal splicing through an in vitro splicing assay and study of the patients’ RNA. We obtained evidence that this synonymous mutation leads to complete exon 9 skipping, and in silico bioinformatics analysis demonstrated that the CUL3 c.1221A > G mutation might decrease the ratio of exonic splicing enhancers and silencers. This is the first report of PHAII in Chinese patients with a novel CUL3 mutation. Our findings add a novel pathogenic splicing variant to the CUL3 mutational spectrum and provide reference for further research on mechanisms of splicing modulation and development of potential therapeutic reagents for PHAII.

A recurrent deletion in the SLC5A2 gene including the intron 7 branch site responsible for familial renal glucosuria

Familial renal glycosuria (FRG) is caused by mutations in the SLC5A2 gene, which codes for Na⁺-glucose co-transporters 2 (SGLT2). The aim of this study was to analyze and identify the mutations in 16 patients from 8 families with FRG. All coding regions, including intron-exon boundaries, were analyzed using PCR followed by direct sequence analysis. Six mutations in SLC5A2 gene were identified, including five missense mutations (c.393G > C, p.K131N; c.1003A > G, p.S335G; c.1343A > G, p.Q448R; c.1420G > C, p.A474P; c.1739G > A, p.G580D) and a 22-bp deletion in intron 7 (c.886(-10_-31)del) removing the putative branch point sequence. By the minigene studies using the pSPL3 plasmids, we confirmed that the deletion c.886(-10_-31)del acts as a splicing mutation. Furthermore, we found that this deletion causes exclusion of exon 8 in the SCL5A2 transcript in patients. The mutation c.886(-10_-31)del was present in 5 (62.5%) of 8 families, and accounts for about 37.5% of the total alleles (6/16). In conclusion, six mutations resulting in FRG were found, and the c.886(-10_-31)del may be the high frequency mutation that can be screened in FRG patients with uniallelic or negative SLC5A2 mutations.

Genotype/Phenotype Analysis in 67 Chinese Patients with Gitelman's Syndrome

BACKGROUND

Gitelman's syndrome (GS) is an autosomal recessive renal tubular disorder, which is caused by the mutations in SLC12A3. This study was designed to analyze the characteristics of the genotype and phenotype, and follow-up in the largest group of Chinese patients with GS.

METHODS

Sixty-seven patients with GS underwent SLCl2A3 analysis, and their clinical characteristics and biochemical findings as well as follow-up were reviewed, aiming to achieve a better description of GS. Additionally, the association of genotype and phenotype was explored.

RESULTS

Forty-one different mutations were identified within these 67 GS patients, including 11 novel mutations and 5 recurrent ones. Typical hypocalciuria and hypomagnesemia were not found in 6 (9%) and 8 (11.9%) patients, respectively. Male patients and those harboring severe mutations in both alleles had significant higher urinary fractional excretion (FE) of potassium, magnesium and chlorine. In addition, there were 2 patients who had chronic kidney disease (estimated glomerular filtration rate <60 ml/min/1.73 m2) and 32 patients with abnormal glucose metabolism.

CONCLUSIONS

We identified 41 mutations related to GS, containing 11 novel variants and 5 high-frequency ones, which should facilitate earlier and more accurate diagnosis of GS. FE of electrolytes in urine may be more sensitive in the phenotype evaluation and differential diagnosis than corresponding serum electrolytes. Hypokalemia and hypomagnesemia in GS were difficult to correct; however, spironolactone might be helpful for hypokalemia to some degree. Compared with normal people, patients with GS were at higher risk of developing type 2 diabetes.

Diabetes mellitus and risk of hip fractures: a meta-analysis

This meta-analysis revealed that diabetic adults had a twofold greater risk of hip fractures compared with non-diabetic populations, and this association was more pronounced in type 1 diabetes.

INTRODUCTION

The relationship between diabetes mellitus and risk of hip fracture yielded conflicting results. We conducted a meta-analysis to investigate the association between diabetes mellitus and the risk of hip fractures based on observational studies.

METHODS

We conducted a systematic literature search of PubMed and Embase databases through May 2015. We selected cohort and case-control studies providing at least age-adjusted risk ratio (RR) and corresponding 95 % confidence intervals (CI) of hip fractures among diabetic and non-diabetic subjects. Moreover, we pooled the female-to-male RR of hip fractures from studies that reported gender-specific risk estimate in a single study.

RESULTS

Twenty-one studies involving 82,293 hip fracture events among 6,995,272 participants were identified. Diabetes mellitus was associated with an increased risk of hip fractures (RR 2.07; 95 % CI 1.83-2.33) in a random effects model. Subgroup analysis indicated that excess risk of hip fracture was more pronounced in type 1 diabetes (RR 5.76; 95 % CI 3.66-9.07) than that in type 2 diabetes (RR 1.34; 95 % CI 1.19-1.51). The pooled female-to-male RR of hip fractures was 1.09 (95 % CI 0.93-1.28).

CONCLUSIONS

Individuals with diabetes mellitus have an excessive risk of hip fractures, and this relationship is more pronounced in type 1 diabetes. The association between diabetes and hip fracture risk is similar in men and women.

Two Novel HOGA1 Splicing Mutations Identified in a Chinese Patient with Primary Hyperoxaluria Type 3

BACKGROUND

Twenty-six HOGA1 mutations have been reported in primary hyperoxaluria (PH) type 3 (PH3) patients with c.700 + 5G>T accounting for about 50% of the total alleles. However, PH3 has never been described in Asians.

METHODS

A Chinese child with early-onset nephrolithiasis was suspected of having PH. We searched for AGXT, GRHPR and HOGA1 gene mutations in this patient and his parents. All coding regions, including intron-exon boundaries, were analyzed using PCR followed by direct sequence analysis.

RESULTS

Two heterozygous mutations not previously described in the literature about HOGA1 were identified (compound heterozygous). One mutation was a successive 2 bp substitution at the last nucleotide of exon 6 and at the first nucleotide of intron 6, respectively (c.834_834 + 1GG>TT), while the other one was a guanine to adenine substitution of the last nucleotide of exon 6 (c.834G>A). Direct sequencing analysis failed to find these mutations in 100 unrelated healthy subjects and the functional role on splicing of both variants found in this study was confirmed by a minigene assay based on the pSPL3 exon trapping vector. In addition, we found a SNP in this family (c.715G>A, p.V239I). There were no mutations detected in AGXT and GRHPR.

CONCLUSION

Two novel HOGA1 mutations were identified in association with PH3. This is the first description and investigation on mutant gene analysis of PH3 in an Asian.

Synthesis of polymer-silica hybrid microparticles with defined geometry using surface initiated atom transfer radical polymerization

In vivo functionalization of the diatom with an initiator site allows grafting from the surface via SI-ATRP.

Overexpression of ubiquitin-specific protease 22 predicts poor survival in patients with early-stage non-small cell lung cancer

Ubiquitin-specific protease 22 (USP22), a novel ubiquitin hydrolase, has been implicated in oncogenesis and cancer progression in various types of human cancer. However, the clinical significance of USP22 expression in non-small cell lung cancer (NSCLC) has not been determined. In the present study, USP22 messenger RNA (mRNA) and protein levels were analyzed by quantitative real-time polymerase chain reaction (PCR) and western blot analysis in 30 cases of NSCLC and in corresponding non-tumor tissue samples. Furthermore, immunohistochemistry was performed to detect USP22 protein expression in 86 primary tumor tissues derived from clinically annotated NSCLC cases at stage I-II. In our analysis we found that both USP22 mRNA and protein levels in NSCLC tissues were significantly higher than those in corresponding non-tumor tissues and that there was a significant correlation between the expression of USP22 mRNA and protein (P=0.000, κ=0.732). In addition, a high-level of USP22 expression was observed in 53.3% (39 out of 86) cases and it was correlated with large tumor size (P=0.029) and lymph node metastasis (P=0.026). Patients with tumors displaying a high-level of USP22 expression showed significantly shorter survival (P=0.006, log-rank test). Importantly, multivariate analysis showed that high USP22 protein expression was an independent prognostic factor for NSCLC patients (P=0.003). In sum, our data suggest that USP22 plays an important role in NSCLC progression at the early stage, and that overexpression of USP22 in tumor tissues could be used as a potential prognostic marker for patients with early clinical stage of NSCLC.

Percutaneous Transluminal Revascularization following an Angiotensin Receptor Blocker: Successful Treatment for Flash Pulmonary Edema and Hyponatremic Hypertensive Syndrome

Either flash pulmonary edema or hyponatremic hypertensive syndrome has been described in renal artery stenosis. However, coexistence of these two disorders has never been previously reported. We describe a patient who presented with flash pulmonary edema and hyponatremic hypertensive syndrome associated with bilateral renal artery disease (one complete occlusion, one highly critical renal artery stenosis, the equivalent of unilateral stenosis of a solitary functioning kidney). His blood pressure, hyponatremia, and symptoms of acute heart failure were much improved by an angiotensin receptor blocker. After the procedure of percutaneous transluminal revascularization, his stenotic kidney function and serum sodium levels were completely restored.

High-frequency variant p.T60M in NaCl cotransporter and blood pressure variability in Han Chinese

OBJECTIVE

Frequent studies have confirmed that homozygous or compound heterozygous loss-of-function mutation p.Thr60Met in NaCl cotransporter (NCC) lead to the salt-wasting Gitelman's syndrome (GS) of hypotension. The finding that Thr60 is a key SPAK/OSR1 phosphorylation site on NCC also raises the possible importance of Thr60 in regulating the activity of NCC and blood pressure (BP). However, the association of heterozygous NCC mutation p.Thr60Met and BP has not yet been studied.

METHODS

We collected 38 heterozygous mutation p.Thr60Met carriers, respectively, from 14 GS families confirmed by our previous studies and 1,000 unrelated Han Chinese, and matched them pairwise (sex, age ±2 years and BMI ±1) with 38 unrelated healthy controls. BP and biochemistry data were obtained. Student's t test and χ(2) test were used to compare the differences between these study subjects with the heterozygous variant p.T60M and the controls. p < 0.05 was considered statistically significant.

RESULTS

p.Thr60Met carriers had markedly lower BP (systolic 110.3 ± 13.5 vs. 119.1 ± 15.0 mm Hg; diastolic 70.2 ± 7.0 vs. 75.4 ± 8.2 mm Hg, p < 0.01) than controls. p.Thr60Met heterozygotes had higher fasting plasma glucose concentration (5.35 ± 0.73 vs. 4.95 ± 0.69 mmol/l, p < 0.01). 14 carriers versus 6 control subjects had impaired fasting glucose (36.8 vs. 15.8%, p < 0.01), and p.Thr60Met carriers had higher 24-hour urinary sodium excretion than controls but not significantly (170.2 ± 35.6 vs. 159.5 ± 39.0 mmol, p = 0.10).

CONCLUSIONS

The NCC mutation p.Thr60Met carriers in Han populations have markedly lower BP and slightly higher fasting plasma glucose compared with normal controls.

Pharmacological activity of ibuprofen released from mesoporous silica

Novel drug delivery systems (DDS) to improve the pharmacokinetic profile of hydrophobic drugs following oral administration are an area of keen interest in drug research. An ideal DDS should not adversely affect drug activity, be capable of delivering a therapeutic dose of drug, and allow homogenous drug loading and drug release. Mesoporous silica has been proposed for this application, with ibuprofen employed as the model drug. It was hypothesised that mesoporous silica MCM-41 is capable of delivering a pharmacologically therapeutic dose of ibuprofen. Ibuprofen-loaded MCM-41 can be prepared reproducibly at a drug to carrier ratio of 30% (wt/wt). The release profile was seen to be 90% within 2 h. Initial assessment of COX-1 inhibitory activity suggests the absence of adverse effects attributable to drug-carrier interaction. The results of this study provide further evidence in support of the proposed use of mesoporous silica in drug delivery.

A novel SLC4A1 variant in an autosomal dominant distal renal tubular acidosis family with a severe phenotype

Mutations in SLC4A1, encoding the chloride-bicarbonate exchanger AE1, cause distal renal tubular acidosis (dRTA), a disease of defective urinary acidification by the distal nephron. We searched for SLC4A1 gene mutations in six patients from a Chinese family with a severe phenotype of dRTA (growth impairment, severe metabolic acidosis, with/or without gross nephrocalcinosis and renal impairment). All coding regions of kidney isoform of AE1, including intron-exon boundaries, were analyzed using PCR followed by direct sequence analysis. A novel 1-bp duplication at nucleotide 2713 (c.2713dupG, band 3 Qingdao) in exon 20 of SLC4A1 in this family was identified by direct sequencing analysis. This duplication alters the encoded protein through codon 905, and results in a reading frame for 15 extra condons (instead of 8) before the new stop condon at position 919 (p.Asp905Glyfs15). We suggest that RTA should be considered as a diagnostic possibility in adult subjects with nephrocalcinosis and chronic renal insufficiency, and family survey should be carefully performed.

Clinical trial: benefits and risks of immunomodulators and maintenance infliximab for IBD-subgroup analyses across four randomized trials

BACKGROUND

Benefits and risks of concomitant immunomodulators and maintenance infliximab in inflammatory bowel disease (IBD) patients have not been adequately evaluated.

AIM

To assess the effect of concomitant immunomodulator and infliximab maintenance therapy using data from four prospective, randomized Phase 3 trials in IBD patients.

METHODS

Overall, 1383 patients from ACCENT I and ACCENT II [luminal and fistulizing Crohn's disease trials] and ACT 1 and ACT 2 [ulcerative colitis trials] were analysed. Patients were treated with placebo or infliximab 5 or 10 mg/kg at weeks 0, 2 and 6 followed by every-8-week maintenance therapy. Clinical response, clinical remission, fistula response, complete fistula response, infection and infusion reaction rates; serum infliximab concentrations and immunogenicity were summarized by baseline concomitant immunomodulator subgroup (use or non-use).

RESULTS

Overall, almost 40% of evaluated IBD patients received concomitant immunomodulators. Efficacy, infection, and serious infection rates were generally similar in patients who received maintenance therapy with or without concomitant immunomodulators. There were no consistent differences in serum infliximab concentrations with or without immunomodulators in patients who received scheduled maintenance therapy. Concomitant immunomodulators reduced infusion reactions and immunogenicity.

CONCLUSION

Concomitant immunomodulators did not improve efficacy or pharmacokinetics in IBD patients who received maintenance infliximab.

Coexistence of normotensive primary aldosteronism in two patients with Gitelman's syndrome and novel thiazide-sensitive Na-Cl cotransporter mutations

BACKGROUND

Primary aldosteronism (PA) is the most common form of secondary hypertension, while Gitelman's syndrome (GS) is the most common inherited renal tubular disease. However, coexistence of these two diseases has never been previously reported. AIM AND SUBJECTS: The aim of our study was to describe the association of GS and PA in two unrelated patients and compare their clinical presentation with a group of patients with GS.

METHODS

Ten subjects suspected to have only GS were assigned to the control group. Saline infusion test was used to confirm the diagnosis of PA. GS was confirmed by sequencing of the causal genes (SLC12A3 and CLCNKB) and functional analyses in Xenopus laevis oocytes.

RESULTS

Confirmatory tests, gene analysis, and functional studies demonstrated the coexistence of GS and PA in both patients. In total, nine novel SLC12A3 gene variants, including seven missense mutations, one splice mutation, and one frameshift deletion, were found in 12 subjects. Four mutations (p.T60M, p.T304M, p.T465P, and p.N611T) harbored by the two patients with both PA and GS were revealed to be loss-of-function variants. Although both patients were normotensive, neither of them had normal nocturnal dip.

CONCLUSIONS

Two rare diseases GS and PA may occasionally coexist in one subject. In these patients, salt depletion and volume constriction might explain the absence of hypertension normally seen in PA patients. However, the protective mechanism against hypertension via down-regulation of renal sodium handling was probably not sufficient in those patients, since their normal circadian rhythm of blood pressure was disrupted.

Clinical trial: benefits and risks of immunomodulators and maintenance infliximab for IBD-subgroup analyses across four randomized trials

BACKGROUND

Benefits and risks of concomitant immunomodulators and maintenance infliximab in inflammatory bowel disease (IBD) patients have not been adequately evaluated.

AIM

To assess the effect of concomitant immunomodulator and infliximab maintenance therapy using data from four prospective, randomized Phase 3 trials in IBD patients.

METHODS

Overall, 1383 patients from ACCENT I and ACCENT II [luminal and fistulizing Crohn's disease trials] and ACT 1 and ACT 2 [ulcerative colitis trials] were analysed. Patients were treated with placebo or infliximab 5 or 10 mg/kg at weeks 0, 2 and 6 followed by every-8-week maintenance therapy. Clinical response, clinical remission, fistula response, complete fistula response, infection and infusion reaction rates; serum infliximab concentrations and immunogenicity were summarized by baseline concomitant immunomodulator subgroup (use or non-use).

RESULTS

Overall, almost 40% of evaluated IBD patients received concomitant immunomodulators. Efficacy, infection, and serious infection rates were generally similar in patients who received maintenance therapy with or without concomitant immunomodulators. There were no consistent differences in serum infliximab concentrations with or without immunomodulators in patients who received scheduled maintenance therapy. Concomitant immunomodulators reduced infusion reactions and immunogenicity.

CONCLUSION

Concomitant immunomodulators did not improve efficacy or pharmacokinetics in IBD patients who received maintenance infliximab.

A novel SLC12A3 splicing mutation skipping of two exons and preliminary screening for alternative splice variants in human kidney

BACKGROUND

Gitelman's syndrome is a mild autosomal recessive disorder caused by inactivating mutations of SLC12A3. However, severe phenotype may be associated with compound heterozygous nonfunctional variants such as frameshift and splicing mutations. Because most multi-exon genes are alternatively spliced as shown by recent studies, SLC12A3, with 26 exons, is likely to be alternatively spliced as well.

METHODS

A case of Gitelman's syndrome with both physical and mental retardation was investigated by genetic analysis. In addition, the alternative splice variants of SLC12A3 were screened by RT-PCR.

RESULTS

A novel intron 7 and exon 8 boundary mutation (a successive 13-nucleotide transition: intron 7 as -1 G>A plus exon 8 +1 to +12 delCGGACATTTTTGinsCCGAAAATTTT) was identified in this patient besides a missense mutation Thr60Met. Further cDNA analysis revealed the novel mutation led to skipping of exons 7 and 8. Furthermore, we found an aberrant splice product skipping of exon 7 and identified two high-abundance alternative splice transcripts.

CONCLUSION

This is the first report of a splice mutation of SLC12A3 with multiple-exon skipping in Gitelman's syndrome. This study provides further evidence for the severe phenotype of Gitelman's syndrome and its association with underlying mutations. Additionally, we demonstrated that the pre-mRNA of SLC12A3 was complex spliced.

Favorable effects of lacrimal plugs in patients with an anophthalmic socket

BACKGROUND

The use of punctal plugs in the treatment of dry eyes is well established. Anophthalmic patients have less tears in the anophthalmic socket in comparison to their normal side, due to an absent corneal reflex (Lee & Elsie, 1981a,b). Many of those patients complain of dry eye symptoms, even when they are treated with tear replacement therapy. The authors wished to examine whether they could improve their dry socket complaints with punctal plugs.

PURPOSE

To evaluate the clinical efficacy and tolerability of punctal plug (Smart Plugs) insertion in anophthalmic patients with symptoms of dry eye.

PATIENTS AND METHODS

Interventional case series. Fifteen anophthalmic patients with dry eye symptoms, a Schirmer test of less than 3 mm and an open lacrimal passage were examined before and after insertion of punctal plugs. The patients were asked for their subjective evaluation of the treatment and were examined to evaluate the change. Schirmer tests were compared. Bacterial cultures were taken at both visits.

RESULTS

Schirmer results of less than 3 mm in the anophthalmic socket were obtained in 75% of patients with dry eyes symptoms; 87% of patients in whom punctal plugs were inserted reported an improvement in dry eye sensation. More than half of the patients demonstrated less discharge (p < or = 0.05). Schirmer tests improved from 1.4 mm to 1.9 mm (p < or = 0.05). Patients with a Schirmer outcome of 2 mm or more tended to have less pathogenic bacterial cultures (p = 0.11).

CONCLUSION

Punctal plugs improve the symptoms and signs of dry socket. Punctal plugs seem to reduce the pathogenic bacterial growth in the anophthalmic socket.

Optimal screw diameter for interference fixation in a bone tunnel: a porcine model

The study investigates the optimal interference screw dimensions required to secure a tendon graft in a bone tunnel. A standard 8 mm pig flexor-tendon graft was inserted into a standard open-ended 8 mm bone tunnel of a porcine distal femur and secured using either 7 mm, 8 mm or 9 mm diameter metal interference screws (Arthrex Inc, Naples, FL). The construct was tested to failure using a Shimadzu ASG 10KN Universal Material Testing Machine (Shimadzu, Tokyo, Japan). Load and mode of construct failure were recorded for 37 individual constructs. There was no significant difference in the load at failure between the 7 mm screw (192 N; range 151-232) and 8 mm screw (181 N; range 150-212) (p>0.05). There was a significant difference between the 7 mm screw and the 9 mm screw (109 N; range 67-151) (p=0.006) and between the 8 mm screw and the 9 mm screw (p=0.015). When using a 9 mm screw, 100% of the constructs failed by cut out of the graft at the tunnel opening. The 7 mm constructs failed by slippage of the tendon from the bone tunnel in 83% of cases, with only 17% failing by cut out at the tunnel opening. The 8 mm constructs demonstrated a mixture of failure modes, with slippage occurring in 58% of cases, cut out in 38% and failure of the graft substance in one case (4%). In this model, screw diameters equal to or 1 mm less than the tunnel/tendon diameter provides better fixation than using a screw 1 mm larger. The mode of failure differs for each of these screws.

Vitrectomy to remove a posteriorly dislocated endocapsular tension ring

We treated a patient who had a posteriorly dislocated endocapsular ring associated with decreased vision and intravitreal cortical remnants. The ring was removed by uneventful pars plana vitrectomy. By the last examination, best corrected visual acuity had improved to 6/12 and intraocular pressure had stabilized to within normal limits. A posteriorly dislocated endocapsular ring is a rare complication of cataract surgery. Its removal by pars plana vitrectomy under direct observation is effective and safe.