523 research outputs found
Modulation of left ventricular diastolic distensibility by collateral flow recruitment during balloon coronary occlusion
AbstractOBJECTIVESThe goals of this study were to elucidate the scaffolding effect of blood-filled coronary vasculature and to determine the functional role of recruited collateral flow in modulating left ventricular (LV) distensibility during balloon coronary occlusion (BCO).BACKGROUNDAlthough LV distensibility is an important factor affecting acute dilation after myocardial infarction, the response of LV diastolic pressureāvolume (P-V) relations to coronary occlusion is inconsistent in humans.METHODSMicromanometer and conductance derived LV P-V loops were serially obtained from 16 patients undergoing percutaneous transluminal coronary angioplasty. Coronary collateral flow recruitment was angiographically evaluated by contralateral and ipsilateral contrast injection during BCO.RESULTSIn the group with poor collateral flow (grades 0āI; n = 8), BCO resulted in a downward and rightward shift of the diastolic P-V relations, where end-diastolic volume (EDV) increased by 13% (p < 0.05) without appreciable change in end-diastolic pressure (EDP; 18 Ā± 6 to 18 Ā± 8 mm Hg). In contrast, BCO in the group with good collateral flow (grades IIāIII; n = 8) shifted the diastolic P-V relations upward to the right with a concomitant increase in minimal pressure (min-P; 6 Ā± 4 to 10 Ā± 5 mm Hg, p < 0.05), EDP (15 Ā± 7 to 21 Ā± 9 mm Hg, p < 0.05) and EDV (+10%, p < 0.05). Reactive hyperemia after balloon deflation caused a rapid and parallel upward shift of the diastolic P-V relations with a marked increase in min-P and EDP, especially in the group with poor collateral flow, before any improvement in LV contraction or relaxation abnormalities.CONCLUSIONSGrades of coronary filling, either retrograde or anterograde, abruptly modulate LV distensibility through the rapid scaffolding effect of coronary vascular turgor
Arsenic contamination in groundwater and residents from Ha Nam and Ha Tay Provinces of Red River Delta, Vietnam
Joint Research on Environmental Science and Technology for the Eart
Variant Spectrum of von Hippel-Lindau Disease and Its Genomic Heterogeneity in Japan
Von Hippel-Lindau (VHL) disease is an autosomal dominant, inherited syndrome with variants in the VHL gene, causing predisposition to multi-organ neoplasms with vessel abnormality. Germline variants in VHL can be detected in 80-90% of patients clinically diagnosed with VHL disease. Here, we summarize the results of genetic tests for 206 Japanese VHL families, and elucidate the molecular mechanisms of VHL disease, especially in variant-negative unsolved cases. Of the 206 families, genetic diagnosis was positive in 175 families (85%), including 134 families (65%) diagnosed by exon sequencing (15 novel variants) and 41 (20%) diagnosed by multiplex ligation-dependent probe amplification (MLPA) (one novel variant). The deleterious variants were significantly enriched in VHL disease Type 1. Interestingly, five synonymous or non-synonymous variants within exon 2 caused exon 2 skipping, which is the first report of exon 2 skipping caused by several missense variants. Whole genome and target deep sequencing analysis were performed for 22 unsolved cases with no variant identified and found three cases with VHL mosaicism (variant allele frequency: 2.5-22%), one with mobile element insertion in the VHL promoter region, and two with a pathogenic variant of BAP1 or SDHB. The variants associated with VHL disease are heterogeneous, and for more accuracy of the genetic diagnosis of VHL disease, comprehensive genome and DNA/RNA analyses are required to detect VHL mosaicism, complicated structure variants and other related gene variants
Impact of functional studies on exome sequence variant interpretation in early-onset cardiac conduction system diseases
Aims
The genetic cause of cardiac conduction system disease (CCSD) has not been fully elucidated. Whole-exome sequencing (WES) can detect various genetic variants; however, the identification of pathogenic variants remains a challenge. We aimed to identify pathogenic or likely pathogenic variants in CCSD patients by using WES and 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines as well as evaluating the usefulness of functional studies for determining them.
Methods and Results
We performed WES of 23 probands diagnosed with early-onset (&lt;65 years) CCSD and analyzed 117 genes linked to arrhythmogenic diseases or cardiomyopathies. We focused on rare variants (minor allele frequency &lt; 0.1%) that were absent from population databases. Five probands had protein truncating variants in EMD and LMNA which were classified as āpathogenicā by 2015 ACMG standards and guidelines. To evaluate the functional changes brought about by these variants, we generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the EMD or LMNA homologs in zebrafish. The mean heart rate and conduction velocities in the CRISPR/Cas9-injected embryos and F2 generation embryos with homozygous deletions were significantly decreased. Twenty-one variants of uncertain significance were identified in 11 probands. Cellular electrophysiological study and in vivo zebrafish cardiac assay showed that 2 variants in KCNH2 and SCN5A, 4 variants in SCN10A, and 1 variant in MYH6 damaged each gene, which resulted in the change of the clinical significance of them from āUncertain significanceā to āLikely pathogenicā in 6 probands.
Conclusions
Of 23 CCSD probands, we successfully identified pathogenic or likely pathogenic variants in 11 probands (48%). Functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with CCSD. SCN10A may be one of the major genes responsible for CCSD.
Translational Perspective
Whole-exome sequencing (WES) may be helpful in determining the causes of cardiac conduction system disease (CCSD), however, the identification of pathogenic variants remains a challenge. We performed WES of 23 probands diagnosed with early-onset CCSD, and identified 12 pathogenic or likely pathogenic variants in 11 of these probands (48%) according to the 2015 ACMG standards and guidelines. In this context, functional analyses of a cellular electrophysiological study and in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants, and SCN10A may be one of the major development factors in CCSD
Deoxymugineic acid increases Zn translocation in Zn-deficient rice plants
Deoxymugineic acid (DMA) is a member of the mugineic acid family phytosiderophores (MAs), which are natural metal chelators produced by graminaceous plants. Rice secretes DMA in response to Fe deficiency to take up Fe in the form of Fe(III)āMAs complex. In contrast with barley, the roots of which secrete MAs in response to Zn deficiency, the amount of DMA secreted by rice roots was slightly decreased under conditions of low Zn supply. There was a concomitant increase in endogenous DMA in rice shoots, suggesting that DMA plays a role in the translocation of Zn within Zn-deficient rice plants. The expression of OsNAS1 and OsNAS2 was not increased in Zn-deficient roots but that of OsNAS3 was increased in Zn-deficient roots and shoots. The expression of OsNAAT1 was also increased in Zn-deficient roots and dramatically increased in shoots; correspondingly, HPLC analysis was unable to detect nicotianamine in Zn-deficient shoots. The expression of OsDMAS1 was increased in Zn-deficient shoots. Analyses using the positron-emitting tracer imaging system (PETIS) showed that Zn-deficient rice roots absorbed less 62Zn-DMA than 62Zn2+. Importantly, supply of 62Zn-DMA rather than 62Zn2+ increased the translocation of 62Zn into the leaves of Zn-deficient plants. This was especially evident in the discrimination center (DC). These results suggest that DMA in Zn-deficient rice plants has an important role in the distribution of Zn within the plant rather than in the absorption of Zn from the soil
"Big Three Dragons": a z = 7.15 Lyman BreakGalaxy Detected in [OIII] 88 m, [CII] 158 m, and Dust Continuum with ALMA
We present new ALMA observations and physical properties of a Lyman Break
Galaxy at z=7.15. Our target, B14-65666, has a bright ultra-violet (UV)
absolute magnitude, , and has been spectroscopically
identified in Ly with a small rest-frame equivalent width of
\AA. Previous HST image has shown that the target is comprised of two spatially
separated clumps in the rest-frame UV. With ALMA, we have newly detected
spatially resolved [OIII] 88 m, [CII] 158 m, and their underlying
dust continuum emission. In the whole system of B14-65666, the [OIII] and [CII]
lines have consistent redshifts of , and the [OIII]
luminosity, , is about three times
higher than the [CII] luminosity, . With
our two continuum flux densities, the dust temperature is constrained to be
K under the assumption of the dust emissivity index of
, leading to a large total infrared luminosity of
. Owing to our high spatial
resolution data, we show that the [OIII] and [CII] emission can be spatially
decomposed into two clumps associated with the two rest-frame UV clumps whose
spectra are kinematically separated by km s. We also find
these two clumps have comparable UV, infrared, [OIII], and [CII] luminosities.
Based on these results, we argue that B14-65666 is a starburst galaxy induced
by a major-merger. The merger interpretation is also supported by the large
specific star-formation rate (defined as the star-formation rate per unit
stellar mass), sSFR Gyr, inferred from our SED
fitting. Probably, a strong UV radiation field caused by intense star formation
contributes to its high dust temperature and the [OIII]-to-[CII] luminosity
ratio.Comment: 24 pages, 13 figures, 9 tables. Accepted for publication in PASJ. In
addition to the dust continuum detection in ALMA Band 6 reported in the
original manuscript, we newly report the dust continuum detection in ALMA
Band 8 based on our new ALMA Cycle 5 observation
Percutaneous Cryoablation for the Treatment of Medically Inoperable Stage I Non-Small Cell Lung Cancer
BACKGROUND: To evaluate the midterm results of percutaneous cryoablation for medically inoperable stage I non-small cell lung cancer. METHODOLOGY/PRINCIPAL FINDINGS: Between January 2004 and June 2010, 160 patients underwent computer tomography guided percutaneous cryoablation for lung tumors at our institution. Of these patients, histologically proven stage I lung cancer patients with more than one year of follow-up, were retrospectively reviewed. All of these patients were considered to be medically inoperable with Charlson comorbidity index of 3 or greater. Follow-up was based primarily on computed tomography. There were 22 patients with 34 tumors who underwent 25 sessions of cryoablation treatment. Complications were pneumothoraces in 7 treatments (28%, chest tube required in one treatment), and pleural effusions in 8 treatments (31%). The observation period ranged from 12-68 months, average 29Ā±19 months, median 23 months. Local tumor progression was observed in one tumor (3%). Mean local tumor progression-free interval was 69Ā±2 months. One patient died of lung cancer progression at 68 months. Two patients died of acute exacerbations of idiopathic pulmonary fibrosis which were not considered to be directly associated with cryoablation, at 12 and 18 months, respectively. The overall 2- and 3-year survivals were 88% and 88%, respectively. Mean overall survival was 62Ā±4 months. Median overall survival was 68 months. The disease-free 2- and 3-year survivals were 78% and 67%, respectively. Mean disease-free survival was 46Ā±6 months. Pulmonary function tests were done in 16 patients (18 treatments) before and after cryoablation. Percentage of predicted vital capacity, and percentage of predicted forced expiratory volume in 1 second, did not differ significantly before and after cryoablation (93Ā±23 versus 90Ā±21, and 70Ā±11 versus 70Ā±12, respectively). CONCLUSIONS/SIGNIFICANCE: Although further accumulation of data is necessary regarding efficacy, cryoablation may be a feasible option in medically inoperable stage I lung cancer patients
The 5ā² Flanking Region and Intron1 of the Bovine Prion Protein Gene (PRNP) Are Responsible for Negative Feedback Regulation of the Prion Protein
Transcription factors regulate gene expression by controlling the transcription rate. Some genes can repress their own expression to prevent over production of the corresponding protein, although the mechanism and significance of this negative feedback regulation remains unclear. In the present study, we describe negative feedback regulation of the bovine prion protein (PrP) gene PRNP in Japanese Black cattle. The PrP-expressing plasmid pEF-boPrP and luciferase-expressing plasmids containing the partial promoter fragment of PRNP incorporating naturally occurring single-nucleotide or insertion/deletion polymorphisms were transfected into N2a cells. Transfection of pEF-boPrP induced PrP overexpression and decreased the promoter activity of PRNP in the wild-type haplotype (23-bp Del, 12-bp Del, and ā47C). Reporter gene assays further demonstrated that the 12- and 23-bp Ins/Del polymorphisms, which are thought to be associated with Sp1 (Specific protein 1) and RP58 (Repressor Protein with a predicted molecular mass of 58 kDa), in intron1 and the upstream region, respectively, and an additional polymorphism (ā47CāA) in the Sp1-binding site responded differently to PrP overexpression. With the ā47C SNP, the presence of the Del in either the 23-bp Ins/Del or the 12-bp Ins/Del allele was essential for the negative feedback caused by PrP overexpression. Furthermore, deletion mutants derived from the wild-type haplotype showed that nucleotides ā315 to +2526, which include the 5ā²-flanking region and exon1, were essential for the response. These results indicate that certain negative feedback response elements are located in these sequences, suggesting that regulation by transcription factors such as Sp1 and RP58 may contribute to the negative feedback mechanism of PRNP
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