[Pathogens and clinical characteristics of bacterial infection in hematology department between 2010 and 2014]

OBJECTIVE

To analyze the characteristics of distribution and drug resistance of bacterial infection in several different parts of hematology department inpatients of Anhui Provincial Hospital from January 2010 to December 2014, including patients who had received hematopoietic stem cell transplantation (HSCT).

METHODS

Anti-microbial susceptibility test was done by Kirby-Bauer method and automated systems and the data were analysed by WHONET 5.6 software.

RESULTS

A total of 3 312 copies of inspection samples were analyzed, including 2 716 (82%) blood samples and other 596 specimens (18%). 634 bacterial strains were isolated from 3 312 samples (19.14%) including 488 samples (76.97%) from blood culture. 427 (67.35%) bacterial strains were gram-negative, and the other 207 (32.65%) were gram-positive. Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were most common gram-negative bacterial and the resistant rates to imipenem were 0.8%, 11.8% and 3.3%, respectively. Detection rates of Extended-spectrum beta-lactamases in Escherichia coli and Klebsiella pneumoniae were 83.9% and 75.0%, respectively. At the same time, Coagulase negative Staphylococcus, Streptococcus and Enterococcus were most common kinds of gram-positive bacteria. Methicillin-resistant coagulase negative staphylococcus accounted for 65.9% antibiotic resistance. No vancomycin and/or linezolid and/or tigecycline resistant strains of Staphylococcus spp. and Enterococcus spp. were found in those patients.

CONCLUSION

Patients with hematology diseases had a higher risk of bacterial infections, mainly caused by Gram-negative bacteria. There are different distributions of bacterial in different wards.

Lubiprostone Is Effective in the Treatment of Chronic Idiopathic Constipation and Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

To evaluate the efficacy and safety of lubiprostone in the treatment of chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C).

PATIENTS AND METHODS

We performed a literature search of the MEDLINE, Cochrane, Google Scholar, and ClinicalTrials.gov databases (from January 1, 2005, through January 31, 2015). Relevant studies meeting the inclusion criteria were manually searched by 2 independent reviewers. Efficacy outcomes evaluated at 1 week, 1 month, and 3 months of intervention were weekly frequency of spontaneous bowel movements, severity of constipation, consistency of stools, degree of abdominal pain/discomfort, degree of straining, and abdominal bloating.

RESULTS

Of 246 studies identified, data from 9 trials comprising 1468 patients (63.6%) in the lubiprostone group and 841 (36.4%) in the placebo group were analyzed. We found that lubiprostone treatment significantly improved the severity of constipation, stool consistency, abdominal pain, degree of straining, and abdominal bloating at 1 week (P≤.03) and 1 month (P≤.004), except for abdominal pain at 1 month, which was similar to that when treated with placebo (P=.21). At 3 months, except for abdominal bloating (P=.03), there was no difference between lubiprostone and placebo groups in all other outcomes (P≥.05). Adverse effects such as nausea, vomiting, and diarrhea were common (incidence rate, 2.4%-75%); however, the incidence of serious adverse effects was low (<5%) and was mostly unrelated to lubiprostone treatment.

CONCLUSION

Lubiprostone is a safe and efficacious drug for the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation, with limited adverse effects in 3 months of follow-up.

Detection of anal dysplasia is enhanced by narrow band imaging and acetic acid

AIM

Anal intraepithelial neoplasia precedes the development of anal squamous cell carcinoma. Detection of the lesion is essential to management. This paper describes a prospective study to detect and ablate anal squamous intraepithelial lesions (SILs) using white light narrow band imaging (NBI) and NBI with acetic acid (NBIA).

METHOD

Sixty patients with abnormal anal cytology and risk factors for anal dysplasia underwent examination of the anoderm with a high definition gastroscope and NBIA. Targeted biopsies were taken and the lesions were ablated and characterized histopathologically. Visualization of the anal transitional zone was facilitated by retroflexion and examination through a disposable anoscope.

RESULTS

Targeted biopsies were taken from lesions in 58 patients. No lesion was seen in two patients. Histopathology showed SIL in 48 (80.0%) of 60 biopsies. One biopsy showed lymphoid aggregates. Biopsies in nine (15%) of the 60 patients showed normal mucosa. Lesions were seen in white light in 27 (45%) of the 60 cases, NBI in 39 (65%) and NBIA in 57 (95%). There was no major morbidity. Sensitivity analysis showed that all methods were significantly different from each other.

CONCLUSION

Anal SIL in the anal transitional zone and anal canal can be identified by NBIA. Patient selection influences findings. Limitations include small sample size and non-randomization.

Metabolic approach for tumor delineation in glioma surgery: 3D MR spectroscopy image-guided resection

OBJECT The extent of resection is one of the most essential factors that influence the outcomes of glioma resection. However, conventional structural imaging has failed to accurately delineate glioma margins because of tumor cell infiltration. Three-dimensional proton MR spectroscopy ((1)H-MRS) can provide metabolic information and has been used in preoperative tumor differentiation, grading, and radiotherapy planning. Resection based on glioma metabolism information may provide for a more extensive resection and yield better outcomes for glioma patients. In this study, the authors attempt to integrate 3D (1)H-MRS into neuronavigation and assess the feasibility and validity of metabolically based glioma resection. METHODS Choline (Cho)-N-acetylaspartate (NAA) index (CNI) maps were calculated and integrated into neuronavigation. The CNI thresholds were quantitatively analyzed and compared with structural MRI studies. Glioma resections were performed under 3D (1)H-MRS guidance. Volumetric analyses were performed for metabolic and structural images from a low-grade glioma (LGG) group and high-grade glioma (HGG) group. Magnetic resonance imaging and neurological assessments were performed immediately after surgery and 1 year after tumor resection. RESULTS Fifteen eligible patients with primary cerebral gliomas were included in this study. Three-dimensional (1)H-MRS maps were successfully coregistered with structural images and integrated into navigational system. Volumetric analyses showed that the differences between the metabolic volumes with different CNI thresholds were statistically significant (p < 0.05). For the LGG group, the differences between the structural and the metabolic volumes with CNI thresholds of 0.5 and 1.5 were statistically significant (p = 0.0005 and 0.0129, respectively). For the HGG group, the differences between the structural and metabolic volumes with CNI thresholds of 0.5 and 1.0 were statistically significant (p = 0.0027 and 0.0497, respectively). All patients showed no tumor progression at the 1-year follow-up. CONCLUSIONS This study integrated 3D MRS maps and intraoperative navigation for glioma margin delineation. Optimum CNI thresholds were applied for both LGGs and HGGs to achieve resection. The results indicated that 3D (1)H-MRS can be integrated with structural imaging to provide better outcomes for glioma resection.

Plasmons in graphene moiré superlattices

Moiré patterns are periodic superlattice structures that appear when two crystals with a minor lattice mismatch are superimposed. A prominent recent example is that of monolayer graphene placed on a crystal of hexagonal boron nitride. As a result of the moiré pattern superlattice created by this stacking, the electronic band structure of graphene is radically altered, acquiring satellite sub-Dirac cones at the superlattice zone boundaries. To probe the dynamical response of the moiré graphene, we use infrared (IR) nano-imaging to explore propagation of surface plasmons, collective oscillations of electrons coupled to IR light. We show that interband transitions associated with the superlattice mini-bands in concert with free electrons in the Dirac bands produce two additive contributions to composite IR plasmons in graphene moiré superstructures. This novel form of collective modes is likely to be generic to other forms of moiré-forming superlattices, including van der Waals heterostructures.

Sum-rule constraints on the surface state conductance of topological insulators

We report the Drude oscillator strength D and the magnitude of the bulk band gap E_{g} of the epitaxially grown, topological insulator (Bi,Sb)_{2}Te_{3}. The magnitude of E_{g}, in conjunction with the model independent f-sum rule, allows us to establish an upper bound for the magnitude of D expected in a typical Dirac-like system composed of linear bands. The experimentally observed D is found to be at or below this theoretical upper bound, demonstrating the effectiveness of alloying in eliminating bulk charge carriers. Moreover, direct comparison of the measured D to magnetoresistance measurements of the same sample supports assignment of the observed low-energy conduction to topological surface states.

B-type natriuretic peptide and cirrhosis progression

Brain natriuretic peptide (BNP) is used as a marker of cardiac dysfunction to predict heart failure mortality. The significance of the prognostic ability of BNP for liver cirrhosis remains unknown, although the levels of BNP seen in cirrhosis are high. We aimed to determine whether the BNP level is related to the stage of cirrhosis and could serve as a prognostic marker of cirrhosis (predict the 1-year all-cause mortality). We recruited 92 patients at different stages of cirrhosis and 81 controls matched by age and gender for this study. At admission, cardiac physical examination and BNP measurements were performed. Upon discharge, the 89 patients were followed up for 12 months. The median BNP levels of patients with cirrhosis were 167.0 pg/mL, which were significantly higher than those of the control group (167.0 vs 34.8 pg/mL, P = 0.001). Serum BNP levels were positively correlated with the Child score, the grade of esophageal varices, a history of spontaneous bacterial peritonitis, and the presence of ascites and collateral circulation. BNP levels above the median were associated with an increased occurrence of death within 12 months of discharge (log rank P = 0.025), as determined by univariate and multivariate Cox regression analyses. Esophageal varices, large/medium volume ascites, and BNP levels were related to the clinical outcome (P = 0.034, 0.030, and 0.025, respectively). Together, these results suggested that serum BNP levels are significantly correlated with the stage of cirrhosis, suggesting that BNP levels might serve as a significant predictor for 1-year all-cause mortality.

Gene mutation profiling of primary glioblastoma through multiple tumor biopsy guided by 1H-magnetic resonance spectroscopy

Genetic mutation has served as the biomarkers for the diagnosis and treatment of glioblastoma multiforme (GBM). However, intra-tumor heterogeneity may interfere with personalized treatment strategies based on mutation analysis. This study aimed to characterize somatic mutation profiling of GBM. We collected 33 samples from 7 patients with the primary GBM associated with different Choline (Cho) to N-acetylaspartate (NAA) index (CNI) through the frameless proton magnetic resonance spectroscopy (1H-MRS) guided biopsies and investigated multiple somatic mutations profiling using the AmpliSeq cancer hotspot panel V2. We identified 53 missense or nonsense mutations in 27 genes including some novel mutations such as APC and IDH2. The mutations in EGFR, TP53, PTEN, PIK3CA genes were presented with different frequency and the majority of the mutated gene was only shared by 1-2 samples from one patient. Moreover, we found the association of CNI with histological grade, but there was no significant change of CNI in the presence of TP53, EGFR and PTEN mutations. These data suggest that gene mutations constitute a heterogeneous marker for primary GBM which may be independent of intra-tumor morphological phenotypes of GBM; therefore, gene mutation markers could not be determined from a small number of needle biopsies or only confined to the high-grade region.

Identification of conserved microRNAs and their target genes in Nile tilapia (Oreochromis niloticus) by bioinformatic analysis

MicroRNAs (miRNAs) are a class of non-coding RNAs that play important roles in posttranscriptional regulation of target genes. miRNAs are involved in multiple biological processes by degrading targeted mRNAs or repressing mRNA translation in various organisms. Their conserved nature in various organisms makes them a good source of new miRNA discovery using comparative genomic approaches. In the present study, conserved Nile tilapia (Oreochromis niloticus) miRNAs were identified using a bioinformatic strategy based on expressed sequence tag and genome survey sequence databases. A total of 21 new miRNAs were detected and were found to belong to 17 families. Using mature miRNA sequences as queries, potential targets for tilapia miRNAs were predicted using a local BLAST program and the miRanda software. Target proteins identified using miRanda and BLAST analyses included transcription factors and molecules important in metabolism, transportation, immunity, stress-related activity, growth, and development. These miRNAs and their targets in tilapia may increase the understanding of the role of miRNAs in regulating the growth and development of tilapia.

[DNA barcoding research and its application on medicinal plants of Bletilla H. G. Reichenbach]

To identify adulterants from medicinal plants of Bletilla H. G. Reichenbach, the suitable candidate DNA barcoding of Bletilla was evaluated. In this study, the internal transcribed spacer (ITS) of nuclear ribosomal DNA, the LFY homologous gene intron 2 and chloroplast ycfl gene were amplified and sequenced from forty-one samples. The intra-specific and inter-specific divergences of Bletilla were calculated, and the identification efficiency was assessed using Barcoding Gap, NJ tree by K2P distance and BLAST1 method. The result showed the intra-specific divergence of nrDNA ITS and ycJfl (0.022-0.106 and 0.017-0.106) were obviously higher than the inter-specific divergence (0-0.012 and 0-0.015), and four species of Bletilla were also accurately distinguished in NJ trees. Whereas, there was no Barcoding Gap on LFY homologous gene intron 2, thus it cannot effectively identify species of Bletilla. Using NJ tree of nrDNA ITS and ycfl gene, powdery medicine and the adulterants of Bletilla were successfully unidentified. In conclusion, nrDNA ITS and ycfl can be used as a potential DNA barcoding to identify the medicinal plants in Bletilla and its adulterants. There were only three basic differences on nrDNA ITS between "Jujing baiji" and Bletilla striata of Lu'an in Anhui province, and two basic differences in ycfl. Based on morphological and molecular data, "Jujing baiji" could be recognized as the species of Bletilla striata.

Imaging, procedural and clinical variables associated with tumor yield on bone biopsy in metastatic castration-resistant prostate cancer

BACKGROUND

Understanding the mechanisms driving disease progression is fundamental to identifying new therapeutic targets for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC). Owing to the prevalence of bone metastases in mCRPC, obtaining sufficient tumor tissue for analysis has historically been a challenge. In this exploratory analysis, we evaluated imaging, procedural and clinical variables associated with tumor yield on image-guided bone biopsy in men with mCRPC.

METHODS

Clinical data were collected prospectively from men with mCRPC enrolled on a phase II trial with serial metastasis biopsies performed according to standard clinical protocol. Imaging was retrospectively reviewed. We evaluated the percent positive biopsy cores (PPC), calculated as the number of positive cores divided by the total number of cores collected per biopsy.

RESULTS

Twenty-nine men had 39 bone biopsies. Seventy-seven percent of bone biopsies had at least one positive biopsy core. We determined that lesion size and distance from the skin to the lesion edge correlated with tumor yield on biopsy (median PPC 75% versus 42% for lesions >8.8 cm(3) versus ⩽ 8.8 cm(3), respectively, P=0.05; median PPC 33% versus 71% for distance ⩾ 6.1 versus <6.1 cm, respectively, P = 0.02). There was a trend towards increased tumor yield in patients with increased uptake on radionuclide bone scan, higher calcium levels and shorter duration of osteoclast-targeting therapy, although this was not statistically significant. Ten men had 14 soft tissue biopsies. All soft tissue biopsies had at least one positive biopsy core.

CONCLUSIONS

This exploratory analysis suggests that there are imaging, procedural and clinical variables that have an impact on image-guided bone biopsy yield. In order to maximize harvest of prostate cancer tissue, we have incorporated a prospective analysis of the metrics described here as part of a multi-institutional project aiming to use the molecular characterization of mCRPC tumors to direct individual therapy.

Pain following double-bundle anterior cruciate ligament reconstruction: correlation with morphological graft findings and dynamic contrast-enhanced MRI

AIM

To determine the relationship between knee pain following anterior cruciate ligament (ACL) graft placement with morphological graft findings and dynamic contrast enhancement as assessed at MRI.

MATERIAL AND METHODS

Following institutional review board approval, 37 consecutive patients with double-bundle ACL reconstruction were enrolled. Thirteen patients had pain and 24 were asymptomatic. Imaging was performed using a 1.5 T MRI machine an average of 7.6 months after surgery. Graft-related (increase signal intensity, abnormal orientation, discontinuity, cystic degeneration, anterior translation of lateral tibia, arthrofibrosis), and non-graft related causes of knee pain (meniscal tear, cartilage injury, loose bodies, and synovitis) were evaluated. During dynamic contrast enhancement analysis, peak enhancement (ePeak) was calculated by placing a region of interest at the osteoligamentous interface of each bundle. Student's t-test was used for continuous variables analysis and chi-square or Fisher's exact test was used for categorical variables analysis.

RESULTS

There was no difference between symptomatic and asymptomatic patients regarding morphological graft-related or non-graft-related causes of knee pain. For dynamic contrast enhancement analysis, symptomatic patients had significantly lower ePeak values than asymptomatic patients in the anteromedial (p = 0.008) and posterolateral (p = 0.001) bundles or when using the higher ePeak value in either bundle (p = 0.003).

CONCLUSION

Morphological ACL graft findings as assessed at MRI could not be used to distinguish between symptomatic and asymptomatic patients. However, lower ePeak values had a significant association with knee pain. This may indicate poor neovascularization of the graft, potentially leading to graft failure.

Implication of polymorphisms in DNA repair genes with an increased risk of hepatocellular carcinoma

We explored the association between 4 XRCC1 (Arg194Trp and Arg399Gln) and XPD (Asp312Asn and Lys751Gln) polymorphisms with the development and prognosis of hepatocellular carcinoma (HCC). A total of 218 cases with HCC and 277 healthy controls were included in the study. Genotyping of the XRCC1 (Arg194Trp and Arg399Gln) and XPD (Asp312Asn and Lys751Gln) polymorphisms was performed in a 384-well plate format on the Sequenom MassARRAY platform. We found that individuals with the XRCC1 399AA genotype had a higher risk of HCC compared with the GG genotype (odds ratio, OR = 1.85, 95% confidence interval, CI = 1.03-3.23). Similarly, individuals carrying the XPD 751GG genotype showed a greatly increased risk of HCC (OR = 2.97, 95%CI = 126- 7.38). Cox regression analysis showed that individuals carrying XPD 751Gln/Gln genotypes had a 0.30-fold increased risk of death from HCC. These results suggest that polymorphisms in XRCC1 and XPD may have functional significance in HCC.

Anatomical study of suboccipital vertebral arteries and surrounding bony structures using virtual reality technology

Background

This work aimed to evaluate the efficacy of virtual reality (VR) technology in neurosurgical anatomy through a comparison of the virtual 3D microanatomy of the suboccipital vertebral arteries and their bony structures as part of the resection of tumors in the craniovertebral junction (CVJ) of 20 patients compared to the actual microanatomy of the vertebral arteries of 15 cadaveric headsets.

Material/Methods

The study was conducted with 2 groups of data: a VR group composed of 20 clinical cases and a physical body group (PB group) composed of 15 cadaveric headsets. In the VR group, the dissection and measurements of the vertebral arteries were simulated on a Dextroscope. In the PB group, the vertebral arteries in the cadaver heads were examined under a microscope and anatomical measurements of VA and bony structures were performed. The length and course of the vertebral arteries and its surrounding bony structures in each group were compared.

Results

The distances from the inferior part of the transverse process foramen (TPF) of C1 to the inferior part of TPF of C2 were 17.68±2.86 mm and 18.4±1.82 mm in the PB and VR groups, respectively. The distances between the middle point of the posterior arch of the atlas and the medial intersection of VA on the groove were 17.35±2.23 mm in the PB group and 18.13±2.58 mm in the VR group. The distances between the middle line and the entrance of VA to the lower rim of TPF of Atlas were 28.64±2.67 mm in PB group and 29.23±2.89 mm in VR group. The diameters of the vertebral artery (VA) at the end of the groove and foramen of C2 transverse process were 4.02±046 mm and 4.25±0.51 mm, respectively, in the PB group and 3.54±0.44 mm and 4.47±0.62 mm, respectively, in VR group. The distances between the VA lumen center and midline of the foramen magnum at the level of dural penetration was 10.4±1.13 mm in the PB group and 11.5±1.34 mm in the VR group (P>0.05).

Conclusions

VR technology can accurately simulate the anatomical features of the suboccipital vertebral arteries and their bony structures, which facilitates the planning of individual surgeries in the CVJ.

Higher frequency of CD4(+)CD25(high) Treg cells in hemophilia patients with factor VIII inhibitor

The production of factor VIII inhibitor antibodies remains the most costly and serious complication in replacement therapy of hemophilia A. We investigated the clinical significance of CD4(+)CD25(high) T regulatory (Treg) cells in hemophilia patients. Our trial included 6 severe hemophilia A patients with factor VIII inhibitors, 6 hemophilia patients without inhibition of factor VIII, and 6 healthy persons (controls). Plasma factor VIII: c was measured by clotting assay. Peripheral blood samples were examined using mutiparameter flow cytometry with fluorescent-labeled monoclonal antibodies. Plasma levels of IFN-γ, IL-2, IL-10, and TGF-β were measured by ELISA. The frequency of CD4(+)CD25(high) Treg cells in CD4(+) cells was 1.07 ± 0.38% in inhibitor patients and 0.57 ± 0.14% in non-inhibitor patients. The proportion of Treg cells in healthy controls was similar to that of the non-inhibitor patients. However, there were significant differences between the inhibitor and non-inhibitor patients in levels of IFN-γ, IL-2, IL-10, and TGF-β. We conclude that the proportions of Treg cells and the concentrations of T cell cytokines in inhibitor patients are higher than those in non-inhibitor patients. The increased number of Treg cells and increased T-cell cytokines may be related to the development and efficiency of the factor VIII inhibitor.

Can diffusion tensor imaging noninvasively detect IDH1 gene mutations in astrogliomas? A retrospective study of 112 cases

BACKGROUND AND PURPOSE

IDH1 mutational status probably plays an important role in the predictive response for patients with astroglioma. This study explores whether DTI metrics are able to noninvasively detect IDH1 status in astrogliomas.

MATERIALS AND METHODS

The DTI data of 112 patients with pathologically proven astroglioma (including 25, 12, and 10 cases with IDH1 mutation and 11, 11, and 43 cases without mutation in grades II, III, and IV, respectively) were retrospectively reviewed. The maximal fractional anisotropy, minimal ADC, ratio of maximal fractional anisotropy, and ratio of minimal ADC in the tumor body were measured. In the same World Health Organization grading, the imaging parameters of patients with and without IDH1 R132H mutation were compared by means of optimal metrics for detecting mutations. Receiver operating characteristic curve analysis was performed.

RESULTS

The maximal fractional anisotropy and ratio of maximal fractional anisotropy values had statistical significance between patients with IDH1 R132H mutation and those without mutation in astrogliomas of grades II and III. The areas under the curve for maximal fractional anisotropy and ratio of maximal fractional anisotropy were both 0.92 in grade II and 0.80 and 0.82 in grade III. The minimal ADC value and ratio of minimal ADC value also demonstrated statistical significance between patients with mutation and those without mutation in all astroglioma grades. The areas under the curve for minimal ADC were 0.94 (II), 0.76 (III), and 0.66 (IV), and the areas under the curve for ratio of minimal ADC were 0.93 (II), 0.83 (III), and 0.70 (IV).

CONCLUSIONS

Fractional anisotropy and ADC from DTI can noninvasively detect IDH1 R132H mutation in astrogliomas.

Cardiac autonomic function and insulin resistance for the development of hypertension: a six-year epidemiological follow-up study

BACKGROUND AND AIMS

To explore the impact of cardiac autonomic function (CAF) and insulin resistance (IR) on incident hypertension.

METHODS AND RESULTS

In 1996, 1638 subjects finished baseline examination, which included anthropometry, blood pressures, CAF, blood biochemistry, plasma insulin, urine examination and electrocardiogram. CAF included standard deviation of normal-to-normal intervals or RR intervals (SDNN), low- and high-frequency power spectrum (LF and HF), and LF/HF ratio at supine for 5 min, the RR interval changes during lying-to-standing maneuver, and the ratio between the longest RR interval during expiration and the shortest RR interval during inspiration (E/I ratio). We used homeostasis model assessment to define beta cell function (HOMA-B) and insulin resistance (HOMA-IR). In total, 992 non-hypertensive participants completed the follow-up assessment in 2003 and 959 participants were included for the final analysis. Incident hypertension was determined by blood pressure status at follow-up. In unadjusted model, both square root of HOMA-IR (OR:3.37, 95%CI: 2.10-6.64) and HOMA-B (OR:0.996, 95%CI: 0.992-0.999) were related to incident hypertension. In multivariate model, square root of HOMA-IR (OR:1.97, 95%CI: 1.05-3.70), but not HOMA-B, was associated with incident hypertension. After further adjustment for baseline CAF, the positive relationship between the square root of HOMA-IR and incident hypertension disappeared. In contrast, LF/HF ratio (OR:1.18, 95%CI: 1.01-1.37), HF power (OR:0.98, 95%CI: 0.96-0.999), and E/I ratio (OR:0.71, 95%CI: 0.54-0.95) were each independently associated with incident hypertension after further adjustment for HOMA measures.

CONCLUSION

Sympathovagal imbalance with an apparently decreased parasympathetic tone is an important predictor of incident hypertension independent of IR.

A study on blood–brain barrier ultrastructural changes induced by cerebral hypoperfusion of different stages

OBJECTIVES

To evaluate the ultrastructural changes in the blood-brain barrier (BBB) induced by cerebral hypoperfusion of different stages, which may predispose the brain to the formation of vasogenic edema and hemorrhage under cerebral luxury perfusion.

METHODS

Twenty cerebral steal models with left neck arteriovenous fistula (AVF) were surgically created in Wistar's rats, leading to a noninfarctional reduction in the cerebral blood flow (CBF) by between 25 and 50%, resulting in cerebral hypoperfusion in the AVF side for 3 days (acute stage), 3 weeks (subacute stage) and 3 months (chronic stage), respectively. Another six sham-operated models were made in age-matched rats as control. The BBB ultrastructural changes were assessed by transmission electron microscopy. Ridit analysis was conducted to compare the positive ratio of ultrastructural changes among multiple groups.

RESULTS

Electron microscopy demonstrated no ultrastructural change at the acute stage, however, at the subacute stage, slight vacuolar degeneration was found in the astrocytic foot process layer encircling the capillaries; furthermore, at the chronic stage, the astrocytic foot processes expressed marked vacuolization associated with the adjacent astrocytic degeneration. Meanwhile, in both capillary endothelium and basal lamina layers, no abnormal ultrastructures similar to those in the astrocytic foot processes layer were identified. After cerebral luxury perfusion took place, BBB was disrupted where astrocytic foot processes vacuolization was most distinguished.

CONCLUSION

Astrocytes generate ultrastructural abnormality as a result of chronic cerebral hypoperfusion. Astrocytic foot process vacuolization, which constitutes the major ultrastructural change in the BBB, is the extension of the degeneration of astrocyte body. It is inferred that BBB is prone to structure weakness and function instability, which forms the morphological basis of cerebral luxury perfusion.

Clinical application of motor pathway mapping using diffusion tensor imaging tractography and intraoperative direct subcortical stimulation in cerebral glioma surgery: a prospective cohort study

BACKGROUND

Glioma surgery in eloquent areas remains a challenge because of the risk of postoperative motor deficits.

OBJECTIVE

To prospectively evaluate the efficiency of using a combination of diffusion tensor imaging (DTI) tractography functional neuronavigation and direct subcortical stimulation (DsCS) to yield a maximally safe resection of cerebral glioma in eloquent areas.

METHODS

A prospective cohort study was conducted in 58 subjects with an initial diagnosis of primary cerebral glioma within or adjacent to the pyramidal tract (PT). The white matter beneath the resection cavity was stimulated along the PT, which was visualized with DTI tractography. The intercept between the PT border and DsCS site was measured. The sensitivity and specificity of DTI tractography for PT mapping were evaluated. The efficiency of the combined use of both techniques on motor function preservation was assessed.

RESULTS

Postoperative analysis showed gross total resection in 40 patients (69.0%). Seventeen patients (29.3%) experienced postoperative worsening; 1-month motor deficit was observed in 6 subjects (10.3%). DsCS verified a high concordance rate with DTI tractography for PT mapping. The sensitivity and specificity of DTI were 92.6% and 93.2%, respectively. The intercepts between positive DsCS sites and imaged PTs were 2.0 to 14.7 mm (5.2 ± 2.2 mm). The 6-month Karnofsky performance scale scores in 50 postoperative subjects were significantly increased compared with their preoperative scores.

CONCLUSION

DTI tractography is effective but not completely reliable in delineating the descending motor pathways. Integration of DTI and DsCS favors patient-specific surgery for cerebral glioma in eloquent areas.

Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems.

Design and implementation of a versatile and variable-frequency piezoelectric coefficient measurement system

We present a simple but versatile piezoelectric coefficient measurement system, which can measure the longitudinal and transverse piezoelectric coefficients in the pressing and bending modes, respectively, at different applied forces and a wide range of frequencies. The functionality of this measurement system has been demonstrated on three samples, including a PbZr(0.52)Ti(0.48)O(3) (PZT) piezoelectric ceramic bulk, a ZnO thin film, and a laminated piezoelectric film sensor. The static longitudinal piezoelectric coefficients of the PZT bulk and the ZnO film are estimated to be around 210 and 8.1 pC/N, respectively. The static transverse piezoelectric coefficients of the ZnO film and the piezoelectric film sensor are determined to be, respectively, -0.284 and -0.031 C/m(2).