Genetic analysis of QTL for eye cross and eye diameter in common carp (Cyprinus carpio L.) using microsatellites and SNPs

A group of 107 F1 hybrid common carp was used to construct a linkage map using JoinMap 4.0. A total of 4877 microsatellite and single nucleotide polymorphism (SNP) markers isolated from a genomic library (978 microsatellite and 3899 SNP markers) were assigned to construct the genetic map, which comprised 50 linkage groups. The total length of the linkage map for the common carp was 4775.90 cM with an average distance between markers of 0.98 cM. Ten quantitative trait loci (QTL) were associated with eye diameter, corresponding to 10.5-57.2% of the total phenotypic variation. Twenty QTL were related to eye cross, contributing to 10.8-36.9% of the total phenotypic variation. Two QTL for eye diameter and four QTL for eye cross each accounted for more than 20% of the total phenotypic variation and were considered to be major QTL. One growth factor related to eye diameter was observed on LG10 of the common carp genome, and three growth factors related to eye cross were observed on LG10, LG35, and LG44 of the common carp genome. The significant positive relationship of eye cross and eye diameter with other commercial traits suggests that eye diameter and eye cross can be used to assist in indirect selection for many commercial traits, particularly body weight. Thus, the growth factor for eye cross may also contribute to the growth of body weight, implying that aggregate breeding could have multiple effects. These findings provide information for future genetic studies and breeding of common carp.

Association between the FGB gene polymorphism and ischemic stroke: a meta-analysis

To clarify the relationship between the β-fibrinogen (FGB) genetic polymorphism (-148C>T) and ischemic stroke, we identified studies by searching PubMed, EMBASE, and the Chinese National Knowledge Infrastructure (CKNI) databases. Data from eligible studies were extracted and subjected to meta-analysis. Publication bias was tested using a funnel plot. We identified 12 independent case-control studies containing 1536 ischemic stroke patients and 1329 control subjects. Our results showed that the -148C>T polymorphism in the FGB gene was associated with an increased risk of ischemic stroke [CC vs (TT+CT), odds ratio = 0.69, 95% confidence interval (CI) = 0.59-0.80, P < 0.0001; TT vs (CC+CT), odds ratio = 3.01, 95%CI = 1.29-7.05; P = 0.01; T vs C, odds ratio = 1.32, 95%CI = 1.15-1.52, P < 0.0001] by a meta-analysis. The results of our meta-analysis suggested that the -148C>T polymorphism in the FGB gene is a susceptibility marker of ischemic stroke.

Analysis of the genetic diversity of Chinese native Cannabis sativa cultivars by using ISSR and chromosome markers

Hemp (Cannabis sativa) is an important fiber crop, and native cultivars exist widely throughout China. In the present study, we analyzed the genetic diversity of 27 important Chinese native hemp cultivars, by using inter-simple sequence repeats (ISSR) and chromosome markers. We determined the following chromosome formulas: 2n = 20 = 14m + 6sm; 2n = 20 = 20m; 2n = 20 = 18m + 2sm; 2n = 20 = 16m + 4sm; and 2n = 20 = 12m + 8sm. The results of our ISSR analysis revealed the genetic relationships among the 27 cultivars; these relationships were analyzed by using the unweighted pair-group method based on DNA polymorphism. Our results revealed that all of the native cultivars showed considerable genetic diversity. At a genetic distance of 0.324, the 27 varieties could be classified into five categories; this grouping corresponded well with the chromosome formulas. All of the investigated hemp cultivars represent relatively primitive types; moreover, the genetic distances show a geographical distribution, with a small amount of regional hybridity.

BRAF mutation correlates with recurrent papillary thyroid carcinoma in Chinese patients

PURPOSE

We investigated correlations of somatic BRAF V600E mutation and RET/PTC1 rearrangement with recurrent disease in Chinese patients with papillary thyroid carcinoma (ptc).

METHODS

This prospective study included 214 patients with ptc histologically confirmed between November 2009 and May 2011 at a single institute.

RESULTS

We found somatic BRAF V600E mutation in 68.7% and RET/PTC1 rearrangement in 25.7% of the patients. Although BRAF mutation was not significantly associated with clinicopathologic features such as patient sex or age, multicentric disease, thyroid capsule invasion, tumour stage, or nodal metastasis, it was significantly associated with recurrent disease. Multivariate analysis revealed that BRAF mutation and tumour size were independent risk factors associated with recurrent disease, with odds ratios of 9.072 and 2.387 respectively. The area under the receiver operating characteristic curve increased 8.3% when BRAF mutation was added to the traditional prognostic factors, but that effect was statistically nonsignificant (0.663 vs. 0.746, p = 0.124). RET/PTC1 rearrangement and nodal metastasis were significantly associated in all patients (p = 0.042), marginally associated in ptc patients (p = 0.051), but not associated in microptc patients (p = 0.700). RET/PTC1 rearrangement was not significantly associated with recurrent disease.

CONCLUSIONS

BRAF positivity is an independent predictor of recurrent disease in ptc.

Effect of inhibition of MEK pathway on 5-aza-deoxycytidine-suppressed pancreatic cancer cell proliferation

Pancreatic adenocarcinoma is a lethal disease because it is inoperable at the time of diagnosis. Therefore, the search for new therapeutic approaches is critical. The abnormal expression of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) pathway and alteration in epigenetic modification (DNA methylation and acetylation of histones) is a common feature in the majority of human pancreatic adenocarcinomas. Because DNA methyltransferase levels are regulated by the MEK pathway, we examined the effects of an MEK inhibitor, PD98059, on the action of DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-aza-dC), the epigenetic agent in the pancreatic cell line CFPAC1. Our results showed that PD98059 significantly potentiated the capability of 5-aza-dC to induce a cessation of cell proliferation concomitant with cell cycle arrest. We also observed an increase in tumor suppressor gene expression associated with the efficacy of treatment with PD98059 and 5-aza-dC. Further studies explored the molecular mechanisms by which 5-aza-dC induced the expression of p21(WAF1). We found that 5-aza-dC induced acetylation of histone H3 on the p21(WAF1) gene promoter and demethylation status on the p21(WAF1) gene promoter region. These effects were strikingly enhanced by the concomitant blockade of the MEK pathway. Furthermore, knockdown of p21(WAF1) by small interfering RNA rescued human pancreatic cancer cells from 5-aza-dC-mediated growth inhibition. Taken together, our results show that the MEK inhibitor enhanced the effects of 5-aza-dC in human pancreatic cancer cells. These results suggest that the MEK signal pathway may be a potential target for pancreatic cancer therapy.

Correlation between oxidative stress and L-type calcium channel expression in the ventricular myocardia of selenium-deficient mice

OBJECTIVE

Expression of the Cacna1c (calcium channel, voltage-dependent, L-type, α1C subunit) gene was studied to investigate the relationship between oxidative stress and L-type calcium channels in the myocardium of selenium-deficient mice.

METHODS

Selenium levels in liver and heart tissue samples from mice fed normal or selenium-deficient diets were evaluated by fluorometry. In the same mice, glutathione peroxidase (GPx) and Cacna1c gene expression were analysed, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were measured, oxidoreductase gene expression profiles were analysed (by DNA microarray), and myocardial structural changes were studied.

RESULTS

In selenium-deficient versus control mice, GPx expression and SOD activity were decreased, and Cacna1c expression and MDA concentration were increased. Selenoprotein oxidoreductase and nonselenoprotein oxidoreductase gene expression differed significantly between selenium-deficient and control mice. In selenium-deficient mice, myocardial fibres were separated by loose collagenous tissue; electron microscopy showed shortened sarcomeres, dilated sarcoplasmic reticulum, scattered myofibril lysis and increased mitochondria with amorphous matrix densities.

CONCLUSION

L-type calcium channels were involved in selenium deficiency-induced cardiomyocyte injury, which was positively related to oxidative stress.

Seroprevalence of hepatitis C, hepatitis B virus and syphilis in HIV-1 infected patients in Shandong, China

To determine the seroprevalence of hepatitis C virus (HCV), hepatitis B virus (HBV) and syphilis in HIV-1-infected patients and related risk factors in Shandong province, China, we tested all eligible participants between 2000 and 2010 for the presence of anti-HCV antibody, hepatitis B surface antigen (HBsAg) and non-treponemal antibodies for syphilis after informed consent. Among 2087 HIV-infected patients, anti-HCV antibody was present in 41.2%, HBsAg in 12.6% and rapid plasma reagin (RPR) reactivity in 19.6%. In the multivariate logistic regression model, male gender (adjusted odds ratio [aOR] = 1.41), minority ethnicity (aOR = 1.72), syphilis infection (aOR = 1.40), former paid blood donors (aOR = 3.36), blood transfusion recipients (aOR = 2.91) and injection drug users (aOR = 1.98) were significantly associated with HCV infection. HCV infection (aOR = 1.40) and being men who have sex with men (aOR = 2.38) were significantly associated with syphilis infection. Co-infection with HCV, HBV and syphilis was observed frequently in all described subgroups of HIV infection. The results of this study suggest that it is necessary to screen for these viruses and syphilis in all Chinese HIV-infected patients.

Soil moisture effect on bacterial and fungal community in Beilu River (Tibetan Plateau) permafrost soils with different vegetation types

AIM

This study investigated the effects of environmental variables on the bacterial and fungal communities of the Beilu River (on the Tibetan Plateau) permafrost soils with different vegetation types.

METHODS AND RESULTS

Microbial communities were sampled from meadow, steppe and desert steppe permafrost soils during May, June, August and November, and they were analysed by both pyrosequencing and the use of Biolog EcoPlates. The dominant bacterial and fungal phyla in meadow and steppe soils were Proteobacteria and Ascomycota, whereas Actinobacteria and Basidiomycota predominated in desert steppe soils. The bacterial communities in meadow soils degraded amines and amino acids very rapidly, while polymers were degraded rapidly by steppe communities. The RDA patterns showed that the microbial communities differed greatly between meadow, steppe and desert steppe, and they were related to variations in the soil moisture, C/N ratio and pH. A UniFrac analysis detected clear differences between the desert steppe bacterial community and others, and seasonal shifts were observed. The fungal UniFrac patterns differed significantly between meadow and steppe soils. There were significant correlations between the bacterial diversity (H') and soil moisture (r = 0.506) and C/N (r = 0.527). The fungal diversity (Hf') was significantly correlated with the soil pH (r = 0.541).

CONCLUSION

The soil moisture, C/N ratio and pH were important determinants of the microbial community structure in Beilu River permafrost soils.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results may provide a useful baseline for predicting the variation in microbial communities in response to climate changes.

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.

Coexistent gestational choriocarcinoma and mixed adenocarcinoma of the uterus

OBJECTIVE

To report the first case of a uterine gestational choriocarcinoma coexisting with an endometrial carcinoma (EC) and to discuss its possible pathogenesis.

MATERIALS AND METHODS

All tissues were examined histologically and monoclonal antibodies were used to evaluate the expression of HCG, HPL, P53, PTEN, and ER. Genotyping was performed on DNA extracted from the freshly dissected choriocarcinoma and the paraffin-embedded endometrial carcinoma along with parental blood DNA using multiplex STR-PCR at 16 loci.

RESULTS

Histology identified two distinct tumors: a uterine tumor containing cytotrophoblastic and syncytiotrophoblastic cells and a second distinct neoplasm composed of adenocarcinoma resembling endometrioid and mucinous adenocarcinoma. Genotyping of the choriocarcinoma revealed alleles from both the patient and her husband and was classified as biparental in origin. The endometrial adenocarcinoma contained only maternal alleles and was thus classified as maternal in origin.

CONCLUSIONS

This is the first description of the simultaneous diagnosis of a uterine gestational choriocarcinoma and an EC within the same patient. DNA genotyping and immunohistochemistry are valuable tools in distinguishing the different origins of coexisting tumors.

Molecular cloning and functional characterization of a mouse ccl6 analog gene in the rat

Suppression subtractive hybridization was used to analyze differential expression of genes in rat peritoneal macrophages after granulocyte macrophage colony-stimulating factor treatment. We identified and cloned the mouse C10 analog gene in the rat, and named it as ccl6. The full-length cDNA of rat ccl6 was 467 bp, which contains a single-open reading frame and encodes 116 amino acid residues. Compared with other C-C chemokines, the rat ccl6 gene had an unusual four-exon genome structure instead of the typical three exons, it had the highest homology with murine ccl6. The rat ccl6 gene was localized on chromosome 10, where most of the C-C chemokine superfamily members are located. The recombinant rat C-C chemokine ligand 6 (CCL6) protein was expressed by the pGEX4T-1 plasmid in Escherichia coli BL21. The purified recombinant protein had bioactivity similar to that of mouse CCL6, which is a chemoattractant for macrophages and lymphocytes, but not for neutrophils.

Nitric oxide delivery by core/shell superparamagnetic nanoparticle vehicles with enhanced biocompatibility

We report the synthesis of Fe(3)O(4)/silica core/shell nanoparticles and their functionalization with S-nitrosothiols. These nanoparticles are of immense interest because of their nitric oxide (NO) release capabilities in human alveolar epithelial cells. Moreover, they act as large storage reservoirs of NO that can be targeted magnetically to the specific site with a sustainable release of NO for up to 50 h. Such nanoparticles provide an enhancement of the biocompatibility with released NO while allowing intracellular accumulation ascribed to their small size.

Characterization of PLGA based composite nerve guidance conduits: effect of F127 content on modulus over time in simulated physiological conditions

PLGA/pluronic F127 based nerve guidance conduits (NGCs) for peripheral nerve regeneration offer excellent potential for clinical use. To date, little emphasis has been directed towards the effect of pluronic F127 on their subsequent mechanical properties as a function of degradation time or the physiological environment. This report was designed to redress the balance. This study synthesised 5 groups of 20wt% PLGA NGCs with varied additions of pluronic F127 (range 0-5wt%) to obtain Young's Moduli (E) in the range of 7-107MPa, depending on degradation conditions and pluronic F127 content.

In vitro biocompatibility assessment of functionalized magnetite nanoparticles: biological and cytotoxicological effects

In the biomedical field, nanomaterials have the potential for use in the targeted delivery of drugs in the human body and in the diagnosis and therapy of certain diseases. In the category of targeted delivery, magnetite (Fe(3)O(4)) nanoparticles have received much attention. As with any similar new therapy, when such nanoparticles are functionalized with chemical groups designed to permit the specific attachment of drugs, cytotoxicological testing is necessary before moving to animal models. Here, we consider several variously functionalized magnetite nanoparticles, including those prepared with (1) a monolayer of oleic acid (Fe(3)O(4)@OA), which is subsequently converted to (2) a shell of amine-containing silane (Fe(3)O(4)@NH(2)), (3) a shell of silica (Fe(3)O(4)@SiO(2)), and (4) a shell of amine-containing silane over a shell of silica (Fe(3)O(4)@SiO(2)@NH(2)). These latter three functionalities were evaluated for biocompatibility, cellular morphology, mitochondrial function (MTT assay), lactate dehydrogenase membrane leakage (LDH assay), and proinflammatory potential through enzyme linked immunosorbent assay (ELISA) for interleukin 6 (IL-6). Controlled tests were performed over a period of 72 h, with results showing LDH leakage and abnormal Il-6 secretion at high concentrations (>50 μg/mL). The tests showed that, in addition to the surface characteristics of the nanoparticles, both the nutrient medium and the time of suspension before exposure to cells also contribute to nanoparticle cytotoxicity.

Marine fungal metabolite 1386A alters the microRNA profile in MCF-7 breast cancer cells

Marine fungal metabolite 1386A is a newly identified small molecular compound extracted from the mangrove fungus 1386A in the South China Sea. Preliminary experiments have demonstrated its amazing cytotoxity to cancer cells, while the mechanism remains poorly understood. microRNAs (miRNAs) are a newly identified class of small regulatory RNAs which play an important role in gene regulation at the post-transcriptional level. They usually function as oncogenes or tumor suppressors and are related to drug sensitivity and resistance. We aimed to test the hypothesis that the potential antineoplastic compound, 1386A, alters the miRNA profile in MCF-7 and whether its unknown mechanism may be predicted by analysis of the altered miRNA profile. Cell proliferation was analyzed by MTT assay. The alteration of the miRNA expression profile of MCF-7 cells was investigated using advanced microarray technology. Silico analysis using TargetScan was used to predict the putative targeted transcripts encoding the dysregulated miRNAs. 1386A inhibited MCF-7 cell proliferation in a time- and dose-dependent manner (the IC50 value at 48 h was 17.1 µmol/l). 1386A (17.1 µmol/l) significantly altered the global miRNA expression profile of the MCF-7 cells at 48 h. Forty-five miRNAs were differentially expressed in MCF-7 cells. Target prediction suggested that these miRNAs potentially target many oncogenes and tumor-suppressor genes associated with cancer development, progression and metastasis. The promising antineoplastic compound marine fungal metabolite 1386A alters the miRNA profiles of MCF-7 breast cancer cells. Analyzing the alteration of the miRNA profile caused by this potential antineoplastic compound may help to predict the unknown mechanism of 1386A.

Preferred structures of the atomic Ag islands on silicone oil surfaces

Varying the substrate temperature T(s) from 285 to 353 K, both the aggregation behavior of Ag atoms and the preferred structures of the atomic Ag islands on silicone oil surfaces are investigated. After deposition, the deposited Ag atoms form isolated islands with a preferred height. Our observations reveal that, as T(s) increases, the preferred island height increases from 20.0 to 33.0 nm, which results in the decrease of the Ag apparent coverage, from 9.6 ± 0.1% to 6.5 ± 0.3%. Further, the crystal structure of the Ag islands changes from amorphous to polycrystalline as the substrate temperature T(s) goes up. Subsequently a 3D aggregation mechanism of the Ag atoms on the liquid substrates is proposed.

Magnetic resonance lymphography at 3T: a promising noninvasive approach to characterise inguinal lymphatic vessel leakage

PURPOSE

To explore the feasibility of using 3T high-resolution MR lymphangiography to characterize inguinal lymphatic vessel leakage (LVL).

MATERIALS AND METHODS

Sixteen patients with known inguinal LVL underwent 3T MR lymphangiography and T(2)-weighted imaging. The presence or absence of inguinal LVL and the responsible lymphatic vessels were determined using the above imaging modalities and confirmed by surgical procedure. Afterwards, fifteen patients with recurring LVL following conservative treatment were referred to surgical intervention.

RESULTS

Specific inguinal LVL enhancement patterns and leaking lymphatic vessels were detected in 15 of 16 patients. Compared to the SNR of enhanced lymph nodes, that of the enhanced LVL was significantly greater (t = 7.149, p < 0.01), thereby making it possible to differentiate between LVL sites and enhancing inguinal lymph nodes. Furthermore, the steepest contrast enhancement curve slope of enhanced LVL was lower than that of enhanced lymph nodes (t = -2.860, p = 0.02). After MR diagnosis, 15 patients successfully underwent open exploration and ligation of the leaking lymphatic vessel. Clinical follow-up did not demonstrate recurrence of lymphatic fluid in the groin.

CONCLUSIONS

High-resolution MR lymphangiography combined with T(2)-weighted imaging is a promising approach to identifying specific features of lymphatic vessel leakage in the groin.

An inter-subspecies cloned buffalo (Bubalus bubalis) obtained by transferring of cryopreserved embryos via somatic cell nuclear transfer

The aim of this study was to explore the feasibility of cryopreservation of inter-subspecies cloned embryos in buffalo. In our experiment, river buffalo ear fibroblast nucleus was fused into swamp buffalo oocyte cytoplasm. The blastocyst formation rate for nuclear transfer of freshly thawed cells was not different from those of growing cells, confluent or serum-starved cells. A total of 122 cloned blastocysts derived from cryopreserved fibroblasts were cryopreserved and thawed, 37 were survived, the cryosurvival rate was 30.3%. The survived blastocysts were transferred into 15 recipient buffalos. Five of the recipients established pregnancy, but four of them aborted on day 53, 59, 145 and 179 of gestation respectively. One cross-bred buffalo (Murrah × Swamp buffalo (2n = 49) received three embryos delivered a 40.5 kg female calf by natural delivery on day 320 of gestation. Up to now (13-month old), the cloned calf has been growing well with no abnormity observed. These results demonstrated that cryopreservation of inter-subspecies cloned embryos is feasible to produce buffalo offspring.

Composition-property relationships for an experimental composite nerve guidance conduit: evaluating cytotoxicity and initial tensile strength

The objective of this work was to examine the main (individual), combined (interaction) and second-order (quadratic) effects of: (i) poly(D,L-lactide-co-glycolide) (PLGA), (ii) F127, and (iii) a zinc-silicate based bioactive glass, on the cytotoxicity and ultimate tensile strength of an experimental nerve guidance conduit (NGC). The experimental plan was carried out according to a Box-Behnken design matrix. The effects of each compositional factor were quantified using response surface methodology (RSM) techniques. Linear and quadratic polynomial equations were developed to examine cytotoxicity (after incubation at 3, 7 and 28 days) and initial ultimate tensile strength (UTS(0)). Multiple regression analyses showed that the developed models yielded a good prediction for each response examined. It was observed that the beneficial effects of PLGA and bioactive glass on controlling cytotoxicity appeared greater than that of F127. Furthermore, the experimental conduits (with the exception of CNGC-I and CNGC-K) generally showed superior cytocompatibility when compared with the comparable literature for the clinically used nerve guidance conduit Neurolac(®). In this investigation, optimal compositions for cell viability were obtained for the following composition: PLGA = 18.89 wt%/F127 = 0.52 wt%/glass = 12.71 wt%. The optimization of composition with respect to ultimate tensile strength was also established (desired UTS(0) being based on the properties of the control device Neurolac(®) whose UTS is c.20 MPa). The desired UTS(0) of ≤ 20 MPa was found for the composition: PLGA = 18.63 wt%/F127 = 0.77 wt%/glass = 5.54 wt%. A UTS(0) ≤ 30 MPa was recorded for the composition: PLGA = 18.34 wt%/F127 = 0.62 wt%/glass = 9.83 wt%, such tensile strengths are comparable to, reported values for Neurolac(®). Examination of the composition-property relationships with respect to combining cell viability and UTS(0) indicated preferred compositions in the range 17.97-19.90 wt% PLGA, 0.16-1.13 wt% F127 and between 5.54 and ≤ 20 wt% glass. This research demonstrates the value of a design of experiments approach for the design of novel nerve guidance conduits, and shows that the materials examined may have potential for the repair of peripheral nerve discontinuities.

Expression and activation of β-adrenoceptors in the colorectal mucosa of rat and human

BACKGROUND

The functions of the distal colon are regulated by local and extrinsic neural pathways. In previous studies, we have found that dopamine (DA) and norepinephrine (NE) could evoke colonic ion transport by activating β-adrenoceptors. The present study aims to investigate the segmental differences in expression and activation of β-adrenoceptors in the distal colon in physiological and pathophysiological conditions.

METHODS

Real-time PCR, immunofluorescence, and Western blotting were used to detect the expression of β-adrenoceptors in the rat and human distal colon. Short-circuit current measurements (Isc) were used to assess the role of β-adrenoceptors in ion transport.

KEY RESULTS

DA and NE caused greater suppression of baseline Isc in distal colon adjacent to the rectum than in segments further away from the anus. These responses were inhibited by selective antagonists of β₁- and β₂-adrenoceptors, but not β₃-adrenoceptor. The expression levels of β₁- and β₂-adrenoceptors in colonic mucosa were higher in colorectum than the regions away from the anus of rats and humans. In wrap-restraint stress (2 h), DA-, NE-induced ΔIsc and the expression of β-adrenoceptors in the colorectum were significantly reduced. However, when endogenous catecholamines were depleted by 6-hydroxydopamine (75 mg kg(-1), i.p., 3 days), DA-, NE-induced ΔIsc as well as the expression of β-adrenoceptors were significantly enhanced in the rat colorectum but not in more proximal regions of the distal colon.

CONCLUSIONS & INFERENCES

β₁- and β₂-adrenoceptors are predominantly expressed in the colorectal mucosa. Perturbation of endogenous catecholamine levels influences the expression and activation of β-adrenoceptors in the colorectal region.

Ferrocene derived carbon nanotubes and their application as electrochemical double layer capacitor electrodes

We report on the synthesis of carbon nanotubes (CNTs) by direct thermal decomposition of ferrocene (Fe(C5H5)2). Our studies indicate that presence of a small amount of sulfur along with the ferrocene in the decomposition process strongly affects the quality of the CNTs produced and is crucial for obtaining thin diameter nanotubes. Raman spectroscopic investigations suggest that the atomic ratio of sulfur to the total iron plus sulfur content of approximately 0.09 yields CNTs with highly crystalline structure having diameters ranging from 0.85 nm to 1.75 nm. Electrochemical double layer capacitor electrodes fabricated from these CNTs show impressive energy storage properties, capable of delivering a maximum power density of approximately 27 KW/kg and energy density of approximately 2.12 Wh/Kg.

Study on the inter-subspecies nuclear transfer of river buffalo somatic cell nuclei into swamp buffalo oocyte cytoplasm

The objective of this study was to explore the feasibility of inter-subspecies somatic cell nuclear transfer (SCNT) of river buffalo (50 chromosomes) somatic cell nuclei into swamp buffalo (48 chromosomes) oocyte cytoplasm. The enucleated swamp buffalo oocytes were fused with four different types of river buffalo cells: freshly thawed ear fibroblasts, serum-starved ear fibroblasts, cumulus cells and ear fibroblasts from a cloned buffalo calf. As a result, the developmental competence of embryos reconstructed with freshly thawed ear fibroblasts was the poorest (P<0.01), while those of the other three types were not different from each other. Furthermore, the efficiency of swamp-swamp buffalo, swamp-river buffalo and bovine-buffalo SCNT were also compared. The results showed that the blastocyst rate of swamp-river reconstructed embryos was not different from swamp-swamp embryos, while significantly higher than that of bovine-buffalo embryos (P<0.01). A total of thirty cloned blastocysts derived from freshly thawed ear fibroblasts were transferred into thirteen recipient buffaloes, four recipients established pregnancy, while three of them aborted on Days 65, 75 and 90 of gestation, respectively. One cross-bred buffalo (Murrah x swamp, 49 chromosomes) receiving three embryos delivered a 39 kg female calf on Day 335 of gestation. These results indicate that the inter-subspecies SCNT is feasible to produce swamp-river buffalo embryos, and these can develop to full term and result in live buffalo calves.

Endogenous calcium buffering capacity of substantia nigral dopamine neurons

Dopamine (DA)-containing cells from the substantia nigra pars compacta (SNc) play a major role in the initiation of movement. Loss of these cells results in Parkinson's disease (PD). Changes in intracellular calcium ion concentration ([Ca(2+)](i)) elicit several events in DA cells, including spike afterhyperpolarizations (AHPs) and subthreshold oscillations underlying autonomous firing. Continuous Ca(2+) load due to Ca(2+)-dependent rhythmicity has been proposed to cause the death of DA cells in PD and normal aging. Because of the physiological and pathophysiological importance of [Ca(2+)](i) in DA cells, we characterized their intrinsic Ca(2+)-buffering capacity (K(S)) in brain slices. We introduced a fluorescent Ca(2+)-sensitive exogenous buffer (200 microM fura-2) and cells were tracked from break-in until steady state by stimulating with a single action potential (AP) every 30 s and measuring the Ca(2+) transient from the proximal dendrite. DA neurons filled exponentially with a tau of about 5-6 min. [Ca(2+)](i) was assumed to equilibrate between the endogenous Ca(2+) buffer and the exogenous Ca(2+) indicator buffer. Intrinsic buffering was estimated by extrapolating from the linear relationships between the amplitude or time constant of the Ca(2+) transients versus [fura-2]. Extrapolated Ca(2+)-transients in the absence of fura-2 had mean peak amplitudes of 293.7 +/- 65.3 nM and tau = 124 +/- 13 ms (postnatal day 13 [P13] to P17 animals). Intrinsic buffering increased with age in DA neurons. For cells from animals P13-P17, K(S) was estimated to be about 110 (n = 20). In older animals (P25-P32), the estimate was about 179 (n = 10). These relatively low values may reflect the need for rapid Ca(2+) signaling, e.g., to allow activation of sK channels, which shape autonomous oscillations and burst firing. Low intrinsic buffering may also make DA cells vulnerable to Ca(2+)-dependent pathology.

PTEN polymorphisms and the risk of esophageal carcinoma and gastric cardiac carcinoma in a high incidence region of China

PTEN, as a tumor suppressor gene, plays an important role in regulating cell growth, proliferation, and apoptosis. Two common polymorphisms, -9C/G and IVS4 (-/+), may alter susceptibility to the disease. To test the hypothesis that the genetic variations of PTEN play a role in the etiology of esophageal squamous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA), a population-based case-control study was conducted in 350 ESCC patients, 257 GCA patients, and 634 healthy controls from a high-incidence region of Hebei province, China. The PTEN polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP). The results showed that the family history of upper gastrointestinal cancer (UGIC) significantly increased the risk of developing ESCC and GCA (the age, gender and smoking status adjusted OR = 1.73 and 1.67; 95% CI = 1.29-2.32 and 1.28-2.19, respectively). The overall distribution of the PTEN -9C/G genotype was not significantly different between cancer patients and controls. Compared with the PTEN IVS4-/- genotype, the IVS4+/+ genotype significantly decreased the risk of ESCC and GCA development, the adjusted OR was 0.64 (95% CI = 0.44-0.94) and 0.63 (95% CI = 0.41-0.98), respectively. Stratification analysis by gender, age, smoking status and family history of UGIC showed that the PTEN IVS4-/+ genotype only reduced the risk of ESCC (adjusted OR = 0.55, 95%CI = 0.34-0.90) among subjects with family history of UGIC. While the IVS4+/+ genotype decreased the susceptibility to both ESCC and GCA (adjusted OR = 0.61 and 0.57, 95% CI = 0.37-0.98 and 0.34-0.98, respectively) among male subjects, the IVS4+/+ genotype only decreased the risk of ESCC development among subjects younger than 55 years (adjusted OR = 0.43, 95% CI = 0.21-0.85). In addition, the haplotype analysis found that the -9C/IVS4- haplotype increased the risk of developing ESCC and GCA (OR = 1.31 and 1.24, 95% CI = 1.08-1.58 and 1.001-1.53). Our results suggested that the PTEN IVS4+/+ homozygote may play a protective role in the development of ESCC and GCA, while the haplotype -9C/IVS4- might be the risk factor of the development of ESCC and GCA in the high incidence region population of Hebei province, China.