Diagnostic value of ankle-brachial index in peripheral arterial disease: a meta-analysis

BACKGROUND

In a previous review, we reported that ankle brachial index (ABI) ≤ 0.90 could reliably identify patients with peripheral artery disease (PAD). Since then, more studies have been published which may extend the power of a meta-analysis of studies of diagnostic accuracy of the ABI. MEDLINE and several other databases were searched for studies on sensitivity and specificity of using ABI ≤ 0.90 for PAD diagnosis compared with angiography.

METHODS

Quality of each study was assessed by standards for reporting diagnostic accuracy initiative and quality assessment for studies of diagnostic accuracy tool. Heterogeneity was assessed using the Cochran Q statistic, χ(2), and inconsistency index. The area under the curve and Q* were estimated using summary receiver operator curve. The pooled diagnostic odds ratio (DOR), sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) of ABI ≤ 0.90 to diagnose PAD were estimated using Meta-DiSc software (Meta-DiSc, Madrid, Spain).

RESULTS

Four studies comprising 569 patients (922 limbs) met inclusion criteria. Significant heterogeneity among these studies was not detected in DOR but was evident in pooled sensitivity, specificity, PLR, and NLR. The area under the curve under the summary receiver operator curve is 0.87 (standard error = 0.02) and diagnostic accuracy (Q*) is 0.80 (standard error = 0.02). Additionally, DOR was 15.33 with corresponding 95% confidence intervals of 9.39-25.02. The pooled sensitivity and specificity of ABI ≤ 0.90 for PAD diagnosis were 75% and 86% and the pooled PLR and NLR were 4.18 and 0.29, respectively.

CONCLUSIONS

We conclude that test of ABI ≤ 0.90 can be a useful tool to identify PAD with serious stenosis in clinical practice.

Genetic diversity analysis of barley landraces and cultivars in the Shanghai region of China

We analyzed the genetic diversity of 115 barley germplasms, including 112 landraces and three new barley cultivars grown in the Shanghai region, using a set of 11 SSR markers. Sixty-six alleles were observed at the 11 SSR loci, ranged from three to ten, with a mean of six alleles per locus. The polymorphism information content ranged from 0.568 to 0.853, with a mean of 0.732, indicating considerable genetic variation in barley in the Shanghai area. Clustering analysis indicated that these barley accessions could be divided into two categories (A and B). Ninety-seven six-rowed barley cultivars were classified in the A category; sixteen two-rowed and two six-rowed barley cultivars were classified in the B category. This demonstrated genetic differences between two-rowed and six-rowed barley varieties. In addition, we found that the three new barley cultivars are closely related.

A metabolomic study of low estimated GFR in non-proteinuric type 2 diabetes mellitus

AIMS/HYPOTHESIS

We carried out a urinary metabolomic study to gain insight into low estimated GFR (eGFR) in patients with non-proteinuric type 2 diabetes.

METHODS

Patients were identified as being non-proteinuric using multiple urinalyses. Cases (n = 44) with low eGFR and controls (n = 46) had eGFR values <60 and ≥60 ml min(-1) 1.73 m(-2), respectively, as calculated using the Modification of Diet in Renal Disease formula. Urine samples were analysed by liquid chromatography/mass spectrometry (LC/MS) and GC/MS. False discovery rates were used to adjust for multiple hypotheses testing, and selection of metabolites that best predicted low eGFR status was achieved using least absolute shrinkage and selection operator logistic regression.

RESULTS

Eleven GC/MS metabolites were strongly associated with low eGFR after correction for multiple hypotheses testing (smallest adjusted p value = 2.62 × 10(-14), largest adjusted p value = 3.84 × 10(-2)). In regression analysis, octanol, oxalic acid, phosphoric acid, benzamide, creatinine, 3,5-dimethoxymandelic amide and N-acetylglutamine were selected as the best subset for prediction and allowed excellent classification of low eGFR (AUC = 0.996). In LC/MS, 19 metabolites remained significant after multiple hypotheses testing had been taken into account (smallest adjusted p value = 2.04 × 10(-4), largest adjusted p value = 4.48 × 10(-2)), and several metabolites showed stronger evidence of association relative to the uraemic toxin, indoxyl sulphate (adjusted p value = 3.03 × 10(-2)). The potential effect of confounding on the association between metabolites was excluded.

CONCLUSIONS/INTERPRETATION

Our study has yielded substantial new insight into low eGFR and provided a collection of potential urinary biomarkers for its detection.

Effects of netrin-1 and netrin-1 knockdown on human umbilical vein endothelial cells and angiogenesis of rat placenta

Angiogenesis is an important process essential for the development of placenta. Netrin-1 was first discovered in nervous system and was later found to play roles in angiogenesis. In order to better understand the functional relevance of netrin-1 in placental angiogenesis, we investigated the effect of netrin-1 on human umbilical vein endothelial cells (HUVECs) and rat placenta by employing up-regulation and down-regulation strategies. HUVECs and rat placenta were treated with recombinant netrin-1, and netrin-1 expression in the cells and placenta was reduced by short hairpin RNA (shRNA) in vitro and in vivo. The inhibition efficiency was determined by real-time quantitative polymerase chain reaction (RT-PCR) and Western blotting. The expression of netrin-1 was immunohistochemically located. The results demonstrated that netrin-1 promoted viability, proliferation, migration and tube formation of HUVECs. A strong reduction in cell capability was observed in vitro after netrin-1 expression was inhibited with shRNA. Netrin-1 accelerated neovascularization of placenta in pregnant rats. Suppression of netrin-1 expression in placenta resulted in reduced vascular sprouting in vivo. These findings suggest that netrin-1 is essential for the proper functioning of HUVECs and angiogenesis of rat placenta, and it is involved in the development of placenta and fetus. The proangiogenic effect of netrin-1 might offer an alternative therapeutic approach for the treatment of vascular disease of placenta.

Assessment of the fetal thymus by two- and three-dimensional ultrasound during normal human gestation and in fetuses with congenital heart defects

OBJECTIVES

Our objectives were to compare the size and volume of the developing fetal thymus obtained by two-dimensional ultrasound (2D-US) and three-dimensional ultrasound (3D-US), develop normative data for thymus volume (TV), and investigate TV in fetuses with congenital heart disease (CHD) and normal twin gestations.

METHODS

We studied 321 fetuses (gestational age (GA): 17-39 weeks) including 238 normal singletons, 64 normal twins and 19 singleton fetuses with CHD. We used 2D-US to assess fetal thymus maximum transverse diameter (MTD), maximum transverse area (MTA), anteroposterior diameter (APD) and superoinferior diameter (SID). TV was obtained by 3D-US using virtual organ computer-aided analysis. Measurements were adjusted for estimated fetal weight where appropriate. Linear regression analysis, general linear models and Fisher's Z-transformation were used where appropriate. A nomogram of fetal TV based on singleton gestations was produced according to previously published methods.

RESULTS

Ultrasound assessment of the fetal thymus was possible in 95.3% (306/321) of cases. Both 3D-US and 2D-US measurements were significantly correlated with GA (TV r = 0.989; MTA r = 0.918; MTD r = 0.884; APD r = 0.849; and SID r = 0.816; all P < 0.05). After Fisher's Z-transformation, the correlation between the TV and GA was significantly stronger than that between any individual 2D-US measurement and GA (P < 0.05). Normal twin fetuses had TVs similar to those of singletons adjusted for estimated fetal weight and GA (P = 0.85). TV adjusted for estimated fetal weight and GA was significantly lower in fetuses with CHD than in normal singletons (P < 0.05).

CONCLUSION

2D-US and 3D-US are useful tools for evaluation of the size and volume of the human fetal thymus through gestation. Fetal TV by 3D-US seems to reflect normal development of the thymus in utero better than do 2D-US measurements. Lower TV should be expected in association with CHDs.

Study of brain asymmetries in sporadic and familial first episode patients with schizophrenia

Introduction

Although the deviations of brain volume deficits in sporadic and familial first-episode schizophrenia patients (FEP) had been presented, the difference of brain asymmetries remained unidentified.

Objectives

To assess the potential differences of volumetric asymmetries of gray matter (GM) and white matter (WM) between groups.

Aims

To find out the different injury alteration of sporadic FEP and familial FEP.

Methods

42 sporadic and 30 familiar drug-naïve FEP with and 72 matched normal controls (NC) were recruited. Participants were assessed with neuropsychological tests and scanned by a 3.0T MRI to obtain T1-weighted and DTI images. Lateralization distribution maps of GM and WM volume were generated by employing optimized voxel-based morphometry. The asymmetries were analyzed by comparing calculating Laterality Index (LI) voxel by voxel.

Results

All three groups showed similar overall brain torque. Familiar FEP have more regional extensive GM asymmetry brain lesions compared to sporadic FEP. There was no shared regional lesion between two groups. LIGM and LIWM in right superior temporal were negatively correlated. Significant negative correlations were also found between LIGM of left superior parietal lobule and LIWM of right superior parietal lobule, and between LIGM of right inferior parietal lobule and LIWM of left inferior parietal lobule. The asymmetry in distinct brain regions were related to cognitive deficits especially in the domains of language and memory.

Conclusions

The two patient groups had different alteration in injuries of brain asymmetry. Familiar FEP has more GM extensive asymmetry brain region, which may correlate with their high genetic burdens.

Bone Cell Response to Ion Implanted Silicon Wafers

Results of preliminary investigations on the electrokinetic characterization and osteoblast morphology of ion implanted silicon wafers are presented. The goal of this study is to modify the surface of a material via ion implantation to control cellular interactions at the prosthesis-body interface.

Osteoblast - Orthopaedic Biomaterial Response

An understanding of bone cell response and extracellular matrix production to a biomaterial is crucial for development of new prosthetic devices. The nature of the cellular-biomaterial surface interface will depend upon a number of factors including substrate properties (surface chemistry, charge, topography) as well as biological cellular concerns (i.e. adsorption of attachment factors to the surface, growth factors). The quality of the matrix and bone-bonding may be influenced by these factors. Recently, a short-term in-vitro cell culture assay has demonstrated the initial attachment and spread of human derived bone cells on metallic (titanium and stainless steel) and polymeric surfaces to be dependent on the adsorption of adhesive attachment factor proteins (fibronectin and vitronectin) to the substratum surface [1]. The morphological appearance of human osteoblasts cultured on titanium and stainless steel with time also demonstrated differences compared to tissue culture plastic [2]. Little data however, is available for the mitogenic and gene expression levels of primary human bone cells cultured on commonly used orthopaedic materials and the response of these cells to growth factors. The present study examined the mitogenic response and steady state mRNA expression levels of primary human bone cells cultured on metallic substrates to provide further insight into the nature of cell-substrate interactions.

Prehypertension: a meta-analysis of the epidemiology, risk factors, and predictors of progression

We investigated the prevalence and risk factors of prehypertension, as well as the predictors of progression from prehypertension to hypertension. To do this, we performed a systematic review and meta-analysis of cross-sectional and longitudinal studies, after unrestricted searches of PubMed and The Cochrane Library through September 2010. In addition, we reviewed references, major textbooks, and review articles. Pooled prevalence, standardized mean differences, and odds ratios were estimated by using a random-effects model. Twenty-six articles met our inclusion criteria; these included 20 cross-sectional and 6 longitudinal studies, with a total sample of 250,741 individuals. The overall pooled prevalence of prehypertension was 36%. The pooled prevalence among males was higher than that among females (40% vs 33%). The pooled standardized mean difference for body mass index was 1.37 (95% confidence interval [CI], 1.20-1.55); for total cholesterol, 8.08 (95% CI, 6.71-9.46); for low-density-lipoprotein cholesterol, 5.14 (95% CI, 3.09-7.18); and for fasting plasma glucose, 4.23 (95% CI, 3.28-5.18); all of which showed more significant results in females. The pooled odds ratio was 1.13 (95% CI, 0.93-1.37) for smoking and 0.98 (95% CI, 0.69-1.39) for drinking. In addition, factors such as older age at baseline, male sex, Mongolian race, and being overweight or obese were predictors of progression to hypertension, according to descriptive analysis. The prevalence of prehypertension was relatively high, especially for males. There were many modifiable risk factors associated with prehypertension, to which healthcare providers should pay more attention.

The efficacy of YKL-40 and CA125 as biomarkers for epithelial ovarian cancer

Our objective was to estimate the efficacy of the measurement of serum YKL-40 alone or with CA125 as biomarkers for the diagnosis of epithelial ovarian cancer (EOC) using the YKL-40 ELISA kit. An experimental group of 49 ovarian cancer patients included 42 patients with EOC (53 ± 15 years, range: 19-81 years) and 7 patients (48 ± 13 years, range: 29-36 years) with borderline epithelial ovarian tumor. A control group of 88 non-malignant cases included 42 patients (43 ± 10 years, range: 26-77 years) with benign gynecological disease and 46 healthy women (45 ± 14 years, range: 30-68 years) at a teaching hospital. Both YKL-40 (220.1 ± 94.1 vs 61.6 ± 48.4 and 50.1 ± 41.2 ng/mL) and CA125 (524.9 ± 972.5 vs 13.4 ± 7.6 and 28.5 ± 29.6 U/mL) levels were significantly higher (P < 0.05) in patients with ovarian cancer compared to the healthy and non-malignant groups. YKL-40 had 92.9% sensitivity and 94.4% specificity for the diagnosis of EOC. When YKL-40 and CA125 were tested in parallel, the sensitivity was increased to 98.2%, but the specificity was decreased to 81.3%. The correlations between serum YKL-40 and tumor stage, grade histology, performance status, patient age, and extension of debulking surgery were tested. With increasing stage and grade of EOC, preoperative serum YKL-40 levels were significantly increased (P = 0.029, P = 0.05, respectively). Serum YKL-40 alone or with serum CA125 levels are useful, although with some limitations, to diagnose ovarian cancer. Our study showed that YKL-40 may not be an independent prognostic factor for ovarian cancer. This prospective study may be a new trend in looking for biomarkers that optimize diagnosis of ovarian cancer.

Improving the capacitive deionisation performance by optimising pore structures of the electrodes

In this paper, three types of ordered mesoporous carbons (OMCs) were synthesised by an original template method and a modified sol-gel process involving nickel salts. The effects of pore arrangement pattern (ordered and random), and pore size distribution (mesoporous and microporous) on the desalination performance were investigated by comparing mesoporous carbons with activated carbons (ACs). It is found that the mesoporous carbons prepared by addition of nickel salts demonstrated higher specific capacitances than mesoporous carbons without nickel salts and the activated carbon electrodes. Their electrosorptive deionisation properties were also compared in a dilute NaCl solution (conductivity 100 microS cm(-1)), the amount of adsorbed ions are measured by a flow though apparatus in the laboratory. It is found that the amounts of the adsorbed ions are 15.9 micromol g(-1) for OMCs involving nickel in the synthesis process, 10.3 micromol g(-1) for OMC not involving nickel salts and 4.7 micromol g(-1) for ACs.

Autophagy and Tamoxifen Resistance in Breast Cancer

Resistance totamoxifen in breast cancer patients is a serious therapeutic problem and majorefforts are underway to understand underlying mechanisms. Resistance can be either intrinsic or acquired. We derived matched tamoxifen sensitive and resistant MCF7 sub-clones that allow us to ask what changes occur in a breast cancer cell when it becomes drug resistant. We consider that this approach mimics de novo tamoxifen resistance and we used these sub-clones to study the factors that lead to drug resistance by two different approaches: expression profiling and an ectopic kinase expression screen. These sub-clones were challenged with steroid depleted media, estrogen, and estrogen plus tamoxifen in order to determine the differential gene response in the sensitive vs. resistant cells. We identified 227 genes that were estrogen responsive in both sub-clones but were not blunted in their response to tamoxifen in the resistant cells. We examined a subset of 67 of these genes that showed differences in baseline expression between sensitive and resistant tumors. Using publicly available data from two different clinical studies of women taking tamoxifen, we found that women classified as matching the sensitive pattern had statistically significant longer disease free survival. The tamoxifen response signature was an independent predictor of outcome compared with other clinical variables by multivariate analysis (p=0.05). The hazard ratio (1.9) was among the strongest observed for the study. Signatures like this one may help personalize therapy by planning regimens of adjuvant therapy best suited to each particular patient. In parallel, high-throughput cell-based screens, in which more than 500 human kinases were independently ectopically expressed, identified 31 kinases that conferred drug resistance on sensitive cells. Both expression profiling and an ectopic kinase expression screen led us to HSPB8, a less well known atypical kinase that has been linked to breast cancer. The ectopic expression of HSPB8 in tamoxifen sensitive cells enabled them to grow in the presence of the drug. Moreover, silencing HSPB8 by shRNA in tamoxifen resistant cells led to cell death. Loss of HSPB8 did not cause cell death by apoptosis, but rather by autophagy.Our findings indicate that HSPB8 is a negative regulator of autophagy and may play an important role in tamoxifen resistance. Interestingly, high expression level of HSPB8 predicted an earlier relapse on tamoxifen in breast cancer patients. Tamoxifen itself induced autophagy in sensitive cells but not in resistant ones and tamoxifen resistant cells were sensitive to the induction of autophagy by other drugs.These results may point to an important role for autophagy in the sensitivity to tamoxifen. We anticipate that this kind of analysis will provide insight into the signaling mechanisms related to the action of estrogen and also may facilitate efforts to identify novel targets for therapeutic intervention for ER positive breast tumors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5135.

Effects of strength training on work capacity and parasympathetic heart rate modulation during exercise in physically inactive men

This study was designed to assess the effects of strength training on work capacity and parasympathetic heart rate modulation during exercise in physically inactive men. Seventy-four men aged 20-45 were randomly assigned to training (n=52) and control (n=22) groups. Training groups underwent 10-weeks of progressive strength training. Body composition, one-repetition maximum half-squat and maximal oxygen uptake were measured before and after the intervention. Respiratory gases, heart rate and blood lactate were recorded during a VO2max test on a cycle ergometer. Parasympathetic heart rate modulation was analyzed based on the standard deviation of instantaneous beat-to-beat R-R interval variability (SD1) and its normalized unit (SD1n). Muscle strength and lean body mass increased in the training group. Compared to the control group, time to exhaustion increased significantly in the training group (p<0.05). SD1 and SD1n were elevated in the training group at submaximal exercise intensities (100 W, p<0.05). Blood lactate decreased at submaximal intensities when compared to the control group. Strength training increased exercise capacity, and improved vagal modulation of heart rate at submaximal exercise intensities. These changes may have favourable cardiovascular health implications for sedentary men during normal daily activities.

Severe burn injuries complicating psychogenic polydipsia

In rare cases, psychogenic polydipsia may develop as a post-burn complication, prevalently concerning females. Two such cases are reported, both in female patients. Their treatment and outcome are described.

Disruption of Spodoptera exigua larval development by silencing chitin synthase gene A with RNA interference

RNA interference (RNAi) is a powerful tool for rapidly analyzing gene functions. However, little is known about the possible use of dsRNA/siRNA as a pest control method. Here, we demonstrate that dsRNA/siRNA can induce the silence of chitin synthase gene A (CHSA), which is an important gene for the growth and development of cuticles and trachea in beet armyworm, Spodoptera exigua. Based on the in vitro RNAi experiments in an insect cell line (Trichoplusia ni High 5), in vivo RNAi was performed by injecting synthesized dsRNA/siRNA into the 4th instar larvae of S. exigua. Significantly lower levels of CHSA transcripts were detected. In addition, the cuticle of these insects was disordered and the epithelial walls of larval trachea did not expand uniformly in injected individuals. Moreover, Injections significantly increased abnormalities relative to control larvae. These results highlighted the possibility of dsRNA/siRNA for gene function studies in lepidopteran insects and future pest control.

Using MF-NF-RO train to produce low salt and high nutrient value recycled water for agricultural irrigation

The project investigated and demonstrated that using a selective nanofiltration (NF) membrane and a reverse osmosis (RO) membrane in sequence can produce recycled water with useful levels of nutrient ions, and lower the sodium absorption ratio (SAR) to minimise soil salinity. The recovery of nutrient and useful ions from the wastewater makes NF-RO treated recycled water an attractive option for agricultural irrigation. It was found that the addition of polyacrylic acid (PAA) significantly increased the rejection of divalent ions by SR2 NF element, and kept the sodium rejection largely unchanged. This effect enhanced the enrichment of divalent ions in the NF rejects, and allowed sodium ions to pass to the RO stage. The product water included NF reject and the RO permeate. Overall, the MF-NF-RO train with a PAA aided NF pre-treatment can produce a product water fit for agriculture irrigation purpose, and reduce the scaling on the RO membrane due to calcium ions which are removed by NF, leading to the higher RO recovery. This approach achieved overall higher water production with less waste for disposal.

Effect of placement of calcium sulphate when used for the repair of furcation perforations on the seal produced by a resin-based material

AIM

To evaluate the sealing ability of calcium sulphate when used under composite resin for the repair of furcation perforations having different diameters.

METHODOLOGY

Perforations of different diameter were created in the floors of pulp chambers in 60 extracted human molar teeth with either a number 3 (1 mm diameter) or 5 (1.5 mm diameter) round bur. The specimens of each group were divided into four sub-groups which were repaired with composite resin either alone or in combination with calcium sulphate that created an artificial floor (15 teeth group(-1)). Eight teeth without furcation perforations served as negative controls. In the leakage detection device, 1 mol L(-1) glucose solution was forced under a pressure of 1.5 KPa from the crown towards the pulp chamber floor. The concentration of leaked glucose was measured at 1, 2, 4, 7, 10, 15 and 20 days using a glucose oxidase method and the data evaluated using the rank sum test.

RESULTS

The specimens with larger perforations repaired with composite resin alone had significantly more leakage (P < 0.05). Using calcium sulphate as an artificial floor significantly decreased leakage of smaller perforations (P < 0.05). In groups repaired with calcium sulphate under composite resin, leakage in smaller perforations was markedly lower than that in larger ones (P < 0.05). No significant difference was found between the specimens with 1 or 1.5 mm perforations repaired with resin alone (P > 0.05).

CONCLUSIONS

Calcium sulphate significantly improved the sealing ability of 1 mm perforations repaired with composite resin but not for 1.5 mm perforations.