[Comparison of radiofrequency catheter ablation for paroxysmal supraventricular tachycardia guided by three dimensional navigation with X-ray]

Objective: To compare the therapeutic efficiency and safety of radiofrequency catheter ablation (RFCA) for paroxysmal ventricular tachycardia (PSVT) guided by three-dimensional navigation with X-ray. Methods: One hundred and seventy-six patients with PSVT hospitalized in Department of Cardiology, Zhejiang Provincial People's Hospital between January 2013 and December 2014 were enrolled in this study. RFCA was performed on 95 patients (Group A) guided by the three dimensional electric-field navigation system (NavX) and the procedures were done with the spatial localization method, unless X-ray was needed in some cases.Eighty-one patients (Group B) underwent RFCA guided by X-ray only.The success rate, complications, recurrence rate, operation time, and X-ray exposure were compared between the two groups. Results: The immediate success rate of operation was 100% in the 176 PSVT patients without complications.There were recurrences in 2 cases of Group A, while in 1 case of Group B. The average operation time in Group A was (97±20) min, while (91±26) min in Group B. The median X-ray fluoroscopy time was 3.0 min and radiation dose was 18.5 μGym² in Group A, which were significantly reduced compared with those in Group B (34.5 min, 167.3 μGym²) (P<0.05). There was no significant difference in immediate procedure success rate, complications, recurrence, and operative time between this two groups (P>0.05). Conclusions: The RFCA for PSVT guided by three-dimensional navigation is safe and feasible in the experienced electrophysiological center.Most patients suffer less or no X-ray radiation.

Multidetector computed tomography for detecting left atrial/left atrial appendage thrombus: a meta-analysis

BACKGROUND

The diagnostic accuracy of multidetector computed tomography (MDCT) in the detection of left atrial/left atrial appendage (LA/LAA) thrombus had been tested in many studies; however, the results are controversial.

AIM

The aim of the present study was to evaluate synthetically the diagnostic accuracy of MDCT in LA/LAA thrombus.

METHODS

PubMed and Embase were searched for published prospective studies which compared computed tomography with transoesophageal echocardiography (TEE) in detecting LA/LAA thrombus prior to March 2014. Descriptive and quantitative information was extracted and MetaDiSc 1.4 was used to perform a meta-analysis.

RESULTS

Fifteen prospective clinical controlled trials with 2540 patients fulfilled the inclusion criteria. The pooled sensitivities (SEN): 0.957; pooled specificities (SPE): 0.917; pooled positive likelihood ratio (PLR): 22.017; pooled negative likelihood ratio (NLR): 0.060; pooled diagnostic odds ratio (DOR): 437.43; the area under the curve (AUC): 0.9883; Q*-value: 0.9544. However, in the abovementioned indexes, the heterogeneities were statistically significant between studies (P < 0.05, inconsistency index (I(2) ) > 50%). In a sub-analysis of studies in which delayed imaging, electrocardiogram (ECG) gating and heart rate control were performed, not only the diagnostic accuracy, but also the heterogeneities were significantly improved (pooled SEN 0.991; pooled SPE 0.989; pooled PLR 60.768; pooled NLR 0.034; pooled DOR 2561.7; AUC 0.9972; Q*-value 0.9806; all the indexes' P-value were greater than 0.05 and the I(2) were 0%, except for SPE, I(2) = 54.6%).

CONCLUSION

For patients with TEE intolerance or contraindications, MDCT may be an alternative method, especially when the delayed imaging, ECG gating and heart rate control were performed.

Plexin-B2 promotes invasive growth of malignant glioma

Invasive growth is a major determinant of the high lethality of malignant gliomas. Plexin-B2, an axon guidance receptor important for mediating neural progenitor cell migration during development, is upregulated in gliomas, but its function therein remains poorly understood. Combining bioinformatic analyses, immunoblotting and immunohistochemistry of patient samples, we demonstrate that Plexin-B2 is consistently upregulated in all types of human gliomas and that its expression levels correlate with glioma grade and poor survival. Activation of Plexin-B2 by Sema4C ligand in glioblastoma cells induced actin-based cytoskeletal dynamics and invasive migration in vitro. This proinvasive effect was associated with activation of the cell motility mediators RhoA and Rac1. Furthermore, costimulation of Plexin-B2 and the receptor tyrosine kinase Met led to synergistic Met phosphorylation. In intracranial glioblastoma transplants, Plexin-B2 knockdown hindered invasive growth and perivascular spreading, and resulted in decreased tumor vascularity. Our results demonstrate that Plexin-B2 promotes glioma invasion and vascularization, and they identify Plexin-B2 as a potential novel prognostic marker for glioma malignancy. Targeting the Plexin-B2 pathway may represent a novel therapeutic approach to curtail invasive growth of glioblastoma.

Expression profiles of MMP-1 and TIMP-1 in lumbar intervertebral disc degeneration

Lumbar intervertebral disc degeneration (IDD) is a common clinical pathology and has become a focus for research in recent years. Matrix metalloproteinases (MMPs) are enzymes responsible for the degradation of almost all extracellular matrix proteins (ECM). The over-expression of MMPs or tissue inhibitors of metalloproteinases (TIMPs) may disrupt the dynamic balance of the ECM. Therefore, in the current study, the expression levels of MMP-1 and TIMP-1 in lumbar IDD patients were evaluated in an attempt to elucidate their role in IDD pathogenesis and progression. In total, 60 IDD patients were recruited as the experimental group, along with 20 cases of lumbar vertebral injury without disc degeneration as the control group. Preoperative venous blood samples were collected, and intervertebral disc tissues were collected from the lesion during surgery. Serum and tissue levels of MMP-1 and TIMP-1 were quantified by enzyme-linked immunosorbent assay and immunohistochemical staining, respectively. Serum and tissue MMP-1 levels in IDD patients were significantly higher than those in the control group (P < 0.05). Additionally, sub-group analysis revealed that severe IDD patients had higher MMP-1 levels compared with mild or moderate IDD patients (P < 0.05). However, there were no significant differences in TIMP- 1 levels in either the serum or tissues of IDD patients compared to patients in the control group (P > 0.05). These results demonstrate that MMP-1 expression is increased in IDD, with higher expression observed in more severe cases, whereas TIMP-1 expression was similarly expressed in both normal and degenerated discs.

Impaired cortical neurogenesis in plexin-B1 and -B2 double deletion mutant

Mammalian cortical expansion is tightly controlled by fine-tuning of proliferation and differentiation of neural progenitors in a region-specific manner. How extrinsic cues interface with cell-intrinsic programs to balance proliferative versus neurogenic decisions remains an unsolved question. We examined the function of Semaphorin receptors Plexin-B1 and -B2 in corticogenesis by generating double mutants, whereby Plexin-B2 was conditionally ablated in the developing brain in a Plexin-B1 null mutant background. Absence of both Plexin-Bs resulted in cortical thinning, particularly in the caudomedial cortex. Plexin-B1/B2 double, but not single, mutants exhibited a reduced neural progenitor pool, attributable to decreased proliferation and an altered division mode favoring cell cycle exit. This resulted in deficient production of neurons throughout the neurogenic period, proportionally affecting all cortical laminae. Consistent with the in vivo data, cultured neural progenitors lacking both Plexin-B1 and -B2 displayed decreased proliferative capacity and increased spontaneous differentiation. Our study therefore defines a novel function of Plexin-B1 and -B2 in transmitting extrinsic signals to maintain proliferative and undifferentiated states of neural progenitors. As single mutants displayed no apparent cortical defects, we conclude that Plexin-B1 and -B2 play redundant or compensatory roles during forebrain development to ensure proper neuronal production and neocortical expansion. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 882-899, 2016.

Allelic polymorphism of KIR2DL2/2DL3 in a southern Chinese population

KIR2DL2 and KIR2DL3 segregate as alleles of the same killer cell immunoglobulin-like receptor (KIR) gene locus. They have been associated with viral infectious diseases and certain cancers and their allelic information may help to better comprehend mechanisms. The allelic polymorphism of KIR2DL2/2DL3 has been shown to influence their binding specificity and affinity to the HLA-C1 ligands. The present study aims to investigate the distribution of the allelic polymorphism of KIR2DL2/2DL3 in a southern Chinese population using sequence-specific primer polymerase chain reaction (PCR-SSP) and PCR-sequence-based typing (SBT) at the entire coding sequence. Of the 306 tested individuals, 1.96% were positive for KIR2DL2 only, 78.10% for KIR2DL3 only, and 19.93% for both KIR2DL2 and 2DL3. KIR2DL3 showed a high degree of diversity in the study population with 15 alleles detected including 8 novel ones. The predominant 2DL3 allele in the study population is 2DL3*00101 (92.81%) followed by 2DL3*00201 (24.18%), 2DL3*023 (4.25%), and 2DL3*00109 (1.31%). The remaining 11 2DL3 alleles all had a frequency below 1%. Three detected 2DL2 alleles were 2DL2*00301 (18.95%), 2DL2*00101 (3.59%), and the novel 2DL2*013 (0.33%). These results provide further insight into the KIR gene diversity in Southern Chinese and may help to better understand the role played by KIR genes in associated diseases.

Attenuation of Cerebral Ischemic Injury in Smad1 Deficient Mice

Stroke results in brain tissue damage from ischemia and oxidative stress. Molecular regulators of the protective versus deleterious cellular responses after cerebral ischemia remain to be identified. Here, we show that deletion of Smad1, a conserved transcription factor that mediates canonical bone morphogenetic protein (BMP) signaling, results in neuroprotection in an ischemia-reperfusion (I/R) stroke model. Uninjured mice with conditional deletion of Smad1 in the CNS (Smad1 cKO) displayed upregulation of the reactive astrocyte marker GFAP and hypertrophic morphological changes in astrocytes compared to littermate controls. Additionally, cultured Smad1^-/- astrocytes exhibited an enhanced antioxidant capacity. When subjected to I/R injury by transient middle cerebral artery occlusion (tMCAO), Smad1 cKO mice showed enhanced neuronal survival and improved neurological recovery at 7 days post-stroke. This neuroprotective phenotype is associated with attenuated reactive astrocytosis and neuroinflammation, along with reductions in oxidative stress, p53 induction, and apoptosis. Our data suggest that Smad1-mediated signaling pathway is involved in stroke pathophysiology and may present a new potential target for stroke therapy.

Association between metabolically unhealthy overweight/obesity and chronic kidney disease: the role of inflammation

AIM

Our study explored the association between subtypes of increased fat mass (with or without associated metabolic alterations) and the presence of chronic kidney disease (CKD).

METHODS

In this cross-sectional survey in China, body mass index (BMI) was used to assess fat mass. Metabolically healthy was defined as no insulin resistance or any metabolic syndrome components except abdominal obesity. We also used two previous definitions of metabolically healthy. Multiple logistic regression models were used. Normal weight with metabolic health was designated the reference group. Three other subgroups included normal weight with metabolic unhealthiness, overweight/obesity with metabolic health and overweight/obesity with metabolic unhealthiness.

RESULTS

Of the 2324 subjects, 11.77% overweight/obese subjects were metabolically healthy. Compared with normal-weight subjects who were metabolically healthy, overweight/obese subjects who were metabolically healthy did not have an increased risk of CKD (OR: 0.79, 95% CI: 0.29–2.14; P = 0.64), whereas overweight/obese subjects who were metabolically unhealthy had a significantly higher risk of CKD (OR: 2.47, 95% CI: 1.5–3.95; P < 0.001). Normal-weight subjects who were metabolically unhealthy also had a higher risk of CKD, but the P value was of borderline significance. On further adjusting for C-reactive protein (CRP) levels, ORs were much attenuated, but did not alter the associations observed. Using two other definitions of metabolically healthy resulted in similar results.

CONCLUSION

Metabolically unhealthy overweight/obesity, but not metabolically healthy overweight/obesity, is associated with an increased risk of CKD. Inflammation might mediate at least part of the association between metabolic changes and CKD prevalence.

Temporal Variation of Chemical Persistence in a Swedish Lake Assessed by Benchmarking

Chemical benchmarking was used to investigate the temporal variation of the persistence of chemical contaminants in a Swedish lake. The chemicals studied included 12 pharmaceuticals, an artificial sweetener, and an X-ray contrast agent. Measurements were conducted in late spring, late autumn, and winter. The transformation half-life in the lake could be quantified for 7 of the chemicals. It ranged from several days to hundreds of days. For 5 of the chemicals (bezafibrate, climbazole, diclofenac, furosemide, and hydrochlorothiazide), the measured persistence was lower in late spring than in late autumn. This may have been caused by lower temperatures and/or less irradiation during late autumn. The seasonality in chemical persistence contributed to changes in chemical concentrations in the lake during the year. The impact of seasonality of persistence was compared with the impact of other important variables determining concentrations in the lake: chemical inputs and water flow/dilution. The strongest seasonal variability in chemical concentration in lake water was observed for hydrochlorothiazide (over a factor of 10), and this was attributable to the seasonality in its persistence.

A novel null HLA allele, HLA-DRB1*15:115N, identified in a Chinese family

The novel allele HLA-DRB1*15:115N differs from HLA-B*15:80N by a nucleotide substitution at position 227 T > A.

Association of the IRF5 SNP rs2004640 with systemic sclerosis in Han Chinese

Systemic sclerosis (SSc) is a complex disease involving multiple genetic factors. An association of the IRF5 polymorphism with SSc was reported in Caucasian populations of Europe and North America, as well as in Japanese populations. The present study aimed to examine whether the SSc-associated SNP rs2004640 of IRF5 gene confer susceptibility to SSc and clinical features of SSc in a Han Chinese population. A Han Chinese cohort consisting of 424 SSc patients and 502 healthy controls were examined in the study. TaqMan assays were carried out to examine the SNP. Exact p-values were obtained (Fisher’s test) from 2x2 tables of allele counts and disease status. SSc patients of Han Chinese showed increased homozygous TT genotype of the rs2004640 (p = 0.027, odds ratio (OR) = 1.4, CI =1.03-1.93), which was significantly associated with pulmonary fibrosis of SSc and ATA-positive SSc of Han Chinese. The lcSSc and ACA-positive SSc of Han Chinese appeared also in association with the increased T allele frequency. However, the Chinese dcSSc did not show any association with the rs2004640. The results were consistent with previous reports in other ethnic populations in supporting the notion that polymorphisms of IRF5 may play an important role in susceptibility to SSc.

Effect of estrogen deficiency on the fixation of titanium implants in chronic kidney disease mice

We established a chronic kidney disease (CKD) mouse model with estrogen deficiency and inserted titanium implants into the femur of such mice to investigate the fixation of the implants. Both the histomorphometry and implant resistance indicated that estrogen deficiency impaired the fixation of titanium implants inserted into such mice.

INTRODUCTION

CKD has been regarded as a worldwide public health problem. Estrogen is a critical factor for both renal protection and bone remodeling. A previous study demonstrated that CKD impairs the early healing of titanium implants. However, the combined effect of estrogen deficiency and CKD on the fixation of titanium implants is largely unknown.

METHODS

Forty 9-week-old female C57BL mice were randomly divided into sham, ovariectomy (OVX), CKD, and CKD + OVX groups. Uremia and estrogen deficiency were induced by 5/6 nephrectomy and OVX, respectively. Experimental titanium implants were inserted into the distal end of the femur. Bone-implant contact (BIC) ratio and bone volume (BV/TV) around the implants were histomorphometrically analyzed. The fixation strength of the implant was measured by a biomechanical push-in resistance test.

RESULTS

Serum measurement confirmed a significant increase in serum blood urea nitrogen (BUN) in the CKD group, which was further increased by OVX. Estrogen deficiency led to significant decreases in the BIC ratio, BV/TV, and the push-in resistance in CKD animals. There was a significant interaction between the effects of OVX and CKD, with OVX exacerbating the effects of CKD on BIC ratio and push-in resistance.

CONCLUSIONS

The results indicated that estrogen deficiency exerts a synergistic effect with CKD and further impairs the fixation of titanium implants in CKD mice.

MicroRNA-29A/PTEN pathway modulates neurite outgrowth in PC12 cells

PTEN serves as an intrinsic brake on neurite outgrowth, but the regulatory mechanism that governs its action is not clear. In the present study, miR-29a was found to increase neurite outgrowth by decreasing PTEN expression. Results showed that miR-92a-1, miR-29a, miR-92b, and miR-29c expression levels increased during nerve growth factor (NGF)-induced differentiation of PC12 cells. Based on in silico analysis of possible miR-29a targets, PTEN mRNA may be a binding site for miR-29a. A protein expression assay and luciferase reporter assay showed that miR-29a could directly target the 3'-UTRs (untranslated regions) of PTEN mRNA and down-regulate the expression of PTEN. PC12 cells infected with lentiviral pLKO-miR-29a showed far higher levels of miR-29a and Akt phosphorylation level than those infected with control. This promoted neurite outgrowth of PC12 cells. Collectively, these results indicate that miR-29a is an important regulator of neurite outgrowth via targeting PTEN and that it may be a promising therapeutic target for neural disease.

Using chemical benchmarking to determine the persistence of chemicals in a Swedish lake

It is challenging to measure the persistence of chemicals under field conditions. In this work, two approaches for measuring persistence in the field were compared: the chemical mass balance approach, and a novel chemical benchmarking approach. Ten pharmaceuticals, an X-ray contrast agent, and an artificial sweetener were studied in a Swedish lake. Acesulfame K was selected as a benchmark to quantify persistence using the chemical benchmarking approach. The 95% confidence intervals of the half-life for transformation in the lake system ranged from 780-5700 days for carbamazepine to <1-2 days for ketoprofen. The persistence estimates obtained using the benchmarking approach agreed well with those from the mass balance approach (1-21% difference), indicating that chemical benchmarking can be a valid and useful method to measure the persistence of chemicals under field conditions. Compared to the mass balance approach, the benchmarking approach partially or completely eliminates the need to quantify mass flow of chemicals, so it is particularly advantageous when the quantification of mass flow of chemicals is difficult. Furthermore, the benchmarking approach allows for ready comparison and ranking of the persistence of different chemicals.

[Analysis of ambiguities in HLA sequencing-based typing and its solutions]

OBJECTIVE

To investigate the number and ratio of ambiguous allele combinations from human leukocyte antigen (HLA) confirmatory test by sequencing based typing for unrelated donor marrow transplantation, and to establish an efficient strategy for identifying such ambiguities.

METHODS

A total of 650 donor-receipt samples were genotyped for 5 loci of the HLA gene using an Atria SBT commercial kit. Exons 2, 3 and 4 of HLA-A, -B and -C, exon 2 of HLA-DRB1 and exons 2 and 3 of HLA-DQB1 were tested by routine HLA genotyping. The ratio of usual ambiguous allele combination was calculated. The ambiguities were subjected to further confirmatory test by PCR-SSP or PCR-SBT retest at outside of the routine sequencing region.

RESULTS

Among the 650 tested samples, the ratio of ambiguity at HLA-A, B, C, DRB1 and DQB1 were 76.31% (496/650), 91.08% (592/650), 97.69% (635/650), 88.62% (576/650) and 43.38% (141/650), respectively. A total of 36 ambiguous allele combinations inside the routine sequencing region and 22 ambiguous allele combinations outside of the routine sequencing region were discovered. After removing rare alleles based on the Chinese common and well documented (CWD) Allele Table (Version 1.01), 9 ambiguous CWD allele combinations inside the routine sequencing region, including 3 located in HLA-B, HLA-C and 1 located in other three HLA loci were found. Ten ambiguous CWD allele combinations outside of the routine sequencing region, including 4 located in HLA-C, -DRB1 and 1 in HLA-A, -B respectively were determined. All samples with ambiguous CWD allele combinations could be distinguished by high-resolution PCR-SSP commercial kits or PCR SBT retest at outside of the routine sequencing region.

CONCLUSION

The common and well documented allele combinations in sequencing-based typing at five HLA loci have been analyzed. Our strategy may provide valuable information for more efficient, low cost and accurate method for high resolution genotyping of HLA genes.