Analysis of Heart Rate Variability and Cardiac Autonomic Nerve Remodeling in Streptozotocin-induced Diabetic Rats

BACKGROUND

Diabetes mellitus (DM) is associated with both cardiovascular and autonomic nervous system dysfunction. Spectral analysis of heart rate variability (HRV) can be used to monitor changes in response to autonomic innervation and stimulation of the heart. In this study, conducted in a rat model of diabetes, HRV and changes in associated neurotransmitters and neurotrophic factors in the right atrium (RA) were monitored.

METHODS

Diabetes was induced by streptozotocin (STZ) (60 mg/kg) in male Wistar rats, and HRV data were collected for 10 weeks by telemetry. Time and frequency domains of HRV data were analyzed using established metrics. The levels of various neural enzymes in the RA were determined by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence to characterize autonomic nerve remodeling. Insulin and methycobal were used to block the effects of STZ.

RESULTS

HRV parameters reflecting parasympathetic tone (SDNN, RMSSD and HF domains) sharply decreased in the first 3 weeks after STZ administration; measures of sympathetic tone (SDANN) increased. After a series of adjustments, cardiac autonomic nerve innervation reached a new equilibrium, with a dominance of sympathetic tone. RA levels of tyrosine hydroxylase (TH) increased, and choline acetyltransferase (ChAT) decreased, indicating autonomic nerve remodeling. Levels of growth associated protein-43 (GAP43) and nerve growth factor (NGF) increased during the period of diabetes-induced cardiac-nerve damage; however, the level of ciliary neurotrophic factor (CNTF) decreased. The physical condition and indexes of rats were normalized in different degree after administration of the insulin and methycobal, but not completely recovered.

CONCLUSION

STZ-induced diabetes was associated with cardiac autonomic nerve dysfunction at both the organ and molecular levels. Parasympathetic nerves exhibited severe damage and/or weak recovery; remodeling of sympathetic nerves predominated during 10-weeks of STZ-induced diabetes.

Tevatron constraints on models of the Higgs boson with exotic spin and parity using decays to bottom-antibottom quark pairs

Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value JP=0+. Both collaborations analyzed approximately 10  fb(-) of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with JP=0- and JP=2+ are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the JP=0- hypothesis and the JP=2+ hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the JP=0- and JP=2+ hypotheses, respectively.

Study on water-rock interactions of trace elements in groundwater with leaching experiments

Measurements of trace elements leached from host rocks can indicate the source of flowing groundwater and provide the host rock's fingerprint information that may be useful in understanding the mixing patterns of different groundwaters and flowpaths. In this study, the leaching characteristics of three widely-distributed aquifer host rocks in Southern Nevada were investigated through leaching experiments of 13 trace elements under different experimental conditions (leaching time, pH, grain size, and rock mineralogy). The fraction of leached trace elements from different aquifer host rocks was calculated for examining the water-rock interaction in different conditions. The effect of host rock mineralogy on leachate composition was examined, which could provide useful information about groundwater source. Solute speciation and saturation indices were simulated using geochemical modeling to further explore the redistribution and leaching process of trace elements.

Analysis of structure, function and epitopes of Spirometra erinaceieuropaei casein kinase I

Spirometra erinaceieuropaei casein kinase I (SeCKI) was analyzed using bioinformatical methods to predict its structure and function based on the deduced amino acid sequence from full length cDNA sequence of SeCKI gene with online sites and software programs. The longest open reading frame contains 448 amino acids, 50 kDa and theoretical pI of 4.73, with a complete tubulin domain, a SMART tubulin_C domain and a low complexity region. SeCKI has no signal sequence and no transmembrane domain, but is predicted to be located extracellularly. The secondary structure of SeCKI contains 12 α-helixes, 11 β-strands and 22 coils. SeCKI had 19 potential antigenic epitopes and 25 HLA-I restricted epitopes. Based on phylogenetic analysis of SeCKI sequence, S. erinaceieuropaei has the closest evolutionary status with Hymenolepis microstoma. Information from this study could provide important insights into the identification of diagnostic antigens and molecular targets of anti-sparganum drugs.

Measurement of the B(s)(0) lifetime in the flavor-specific decay channel B(s)(0)→D(s)(-)μ(+)νX

We present an updated measurement of the B(s)(0) lifetime using the semileptonic decays B(s)(0)→D(s)(-)μ(+)νX, with D(s)(-)→ϕπ(-) and ϕ→K(+)K(-) (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at √[s]=1.96  TeV, comprising an integrated luminosity of 10.4  fb(-1). We find a flavor-specific lifetime τ(fs)(B(s)(0))=1.479±0.010(stat)±0.021(syst)  ps. This technique is also used to determine the B(0) lifetime using the analogous B(0)→D(-)μ(+)νX decay with D(-)→ϕπ(-) and ϕ→K(+)K(-), yielding τ(B(0))=1.534±0.019(stat)±0.021(syst)  ps. Both measurements are consistent with the current world averages, and the B(s)(0) lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio τ(fs)(B(s)(0))/τ(B(0))=0.964±0.013(stat)±0.007(syst).

Measurement of the forward-backward asymmetry in the production of B(±) mesons in pp̄ collisions at √s=1.96 TeV

We present a measurement of the forward-backward asymmetry in the production of B(±) mesons, A(FB)(B(±)), using B(±)→J/ψK(±) decays in 10.4  fb(-1) of pp̄ collisions at sqrt[s]=1.96  TeV collected by the D0 experiment during Run II of the Tevatron collider. A nonzero asymmetry would indicate a preference for a particular flavor, i.e., b quark or ̄b antiquark, to be produced in the direction of the proton beam. We extract A(FB)(B(±)) from a maximum likelihood fit to the difference between the numbers of forward- and backward-produced B(±) mesons. We measure an asymmetry consistent with zero: A(FB)(B(±))=[-0.24±0.41  (stat)±0.19  (syst)]%.

Survey and genetic variation of Spirometra erinaceieuropaei sparganum in frogs and snakes from Guangxi of southern China

The prevalence of sparganum infection in wild frogs (Rana rugulosa and R. temporaria) and snakes (Enhydris chinensis) was investigated in Guangxi Zhuang Autonomous Region of Southern China from June 2013 to August 2013. The results showed that 30.37% (65/214) of the caught wild frogs and 50% (3/6) of examined snakes were found to be infected with plerocercoids (spargana) of the genus Spirometra. To investigate the genetic variation of the collected spargana, three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 1 and 3 (cox1 and cox3), NADH dehydrogenase subunits 4 (nad4) were amplified, sequenced, and analyzed. The sequences of cox1, cox3 and pnad4 are 444, 387 and 585 bp in length, respectively. The base composition of cox1, cox3 and pnad4 were generally AT rich with a mean of 62.7%, 67.2% and 64.9%, respectively. Phylogenetic analyses using Bayesian inference (BI) and maximum parsimony (MP) indicated that all the Spirometra sparganum isolates in Guangxi represented S. erinaceieuropaei.

Chronic stress causes neuroendocrine-immune disturbances without affecting renal vitamin D metabolism in rats

INTRODUCTION

Vitamin D (VD) insufficiency has been repeatedly observed in the medical conditions associated with inflammation, such as cardiovascular disease, diabetes and depression. However, contrasting to the observational evidence, randomized trials of VD supplementation failed to demonstrate such link. Given the recent evidence that the inflammatory process can in turn alter VD metabolism, it has been hypothesized that the insufficient VD status could be the result rather than the cause of chronic inflammation involved in the onset of depression and other disease conditions.

MATERIALS AND METHODS

Chronic mild stress (CMS) is a valid animal model of depression that accompanied with neuroendocrine-immune disturbances. In the present research, we assessed serum VD concentrations and renal expression of the cytochromes P450 enzymes involved in VD activation (CYP27B1) and catabolism (CYP24A1) of rats following 8-week exposure to CMS.

RESULTS

While CMS induced the rats to a depression-like state and increased serum levels of the proinflammatory cytokines and corticosterone, and the antidepressant, sertraline, mitigated depression-like behaviors and neuroendocrine-immune disturbances, neither the stress regimen nor sertraline significantly affected endocrine metabolism of VD.

CONCLUSION

Our data suggest that the stress-induced neuroendocrine-immune disturbances may account for the development of depression, but are not responsible for the insufficient VD status that frequently observed in depressed patients.

Constraints on models for the Higgs boson with exotic spin and parity in VH → Vbb final states

We present constraints on models containing non-standard-model values for the spin J and parity P of the Higgs boson H in up to 9.7 fb(-1) of pp collisions at sqrt[s] = 1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider. These are the first studies of Higgs boson J(P) with fermions in the final state. In the ZH → ℓℓbb, WH → ℓνbb, and ZH → ννbb final states, we compare the standard model (SM) Higgs boson prediction, J(P) = 0(+), with two alternative hypotheses, J(P) = 0(-) and J(P) = 2(+). We use a likelihood ratio to quantify the degree to which our data are incompatible with non-SM J(P) predictions for a range of possible production rates. Assuming that the production rate in the signal models considered is equal to the SM prediction, we reject the J(P) = 0(-) and J(P) = 2(+) hypotheses at the 97.6% CL and at the 99.0% CL, respectively. The expected exclusion sensitivity for a J(P) = 0(-) (J(P) = 2(+)) state is at the 99.86% (99.94%) CL. Under the hypothesis that our data are the result of a combination of the SM-like Higgs boson and either a J(P) = 0(-) or a J(P) = 2(+) signal, we exclude a J(P) = 0(-) fraction above 0.80 and a J(P) = 2(+) fraction above 0.67 at the 95% CL. The expected exclusion covers J(P) = 0(-) (J(P) = 2(+)) fractions above 0.54 (0.47).

In vitro and in vivo anticancer effects of mevalonate pathway modulation on human cancer cells

Background:

The increasing usage of statins (the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) has revealed a number of unexpected beneficial effects, including a reduction in cancer risk.

Methods:

We investigated the direct anticancer effects of different statins approved for clinical use on human breast and brain cancer cells. We also explored the effects of statins on cancer cells using in silico simulations.

Results:

In vitro studies showed that cerivastatin, pitavastatin, and fluvastatin were the most potent anti-proliferative, autophagy inducing agents in human cancer cells including stem cell-like primary glioblastoma cell lines. Consistently, pitavastatin was more effective than fluvastatin in inhibiting U87 tumour growth in vivo. Intraperitoneal injection was much better than oral administration in delaying glioblastoma growth. Following statin treatment, tumour cells were rescued by adding mevalonate and geranylgeranyl pyrophosphate. Knockdown of geranylgeranyl pyrophosphate synthetase-1 also induced strong cell autophagy and cell death in vitro and reduced U87 tumour growth in vivo. These data demonstrate that statins main effect is via targeting the mevalonate synthesis pathway in tumour cells.

Conclusions:

Our study demonstrates the potent anticancer effects of statins. These safe and well-tolerated drugs need to be further investigated as cancer chemotherapeutics in comprehensive clinical studies.

Precision measurement of the top quark mass in lepton + jets final States

We measure the mass of the top quark in lepton+jets final states using the full sample of pp collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at sqrt[s] = 1.96 TeV, corresponding to 9.7 fb(-1) of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from tt production or background. The overall jet energy scale is constrained in situ by the mass of the W boson. We measure m(t) = 174.98 ± 0.76 GeV. This constitutes the most precise single measurement of the top-quark mass.

Observation of s-channel production of single top quarks at the Tevatron

We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb(-1) per experiment. The measured cross section is σ(s) = 1.29(-0.24)(+0.26) pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8 × 10(-10), corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.

Direct, reagentless electrochemical detection of the BIR3 domain of X-linked inhibitor of apoptosis protein using a peptide-based conducting polymer sensor

In this work, we report a reagentless electrochemical peptide (AVPFAQKG) sensor to directly detect the BIR3 domain of X-linked inhibitor of apoptosis protein (XIAP-BIR3). The bioreceptor was based on a conducting copolymer film electrosynthesized from juglone and a juglone-peptide conjugate (JP) newly designed. The peptide-protein interactions generated an important increase of steric hindrance at the interface and a current decrease (signal off) of the redox reaction from quinone embedded in the polymer backbone as evidenced by Square Wave Voltammetry. This allowed a specific and sensitive detection of XIAP-BIR3 with a detection limit of 1 nM (13 ng mL(-1)). The peptide-protein complex could be then dissociated by adding the free precursor peptide (AVPFAQKG) into solution, causing a shift-back on the signal, i.e. an increase in the current intensity (signal-on). This "off-on" detection sequence was used in this work as a double verification of the specificity and this approach can be employed as a general way to increase the reliability of the results. In general, the approach described in this work may be inspired to develop other direct and reagentless electrochemical protein assays with high specificity and sensitivity.

Measurement of the W boson production charge asymmetry in pp̄→W+X→eν+X events at √s=1.96 TeV

We present a measurement of the W boson production charge asymmetry in pp̄→W+X→eν+X events at a center of mass energy of 1.96 TeV, using 9.7  fb-1 of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The neutrino longitudinal momentum is determined by using a neutrino weighting method, and the asymmetry is measured as a function of the W boson rapidity. The measurement extends over wider electron pseudorapidity region than previous results and is the most precise to date, allowing for precise determination of proton parton distribution functions in global fits.

Reference-frame-independent quantum-key-distribution server with a telecom tether for an on-chip client

We demonstrate a client-server quantum key distribution (QKD) scheme. Large resources such as laser and detectors are situated at the server side, which is accessible via telecom fiber to a client requiring only an on-chip polarization rotator, which may be integrated into a handheld device. The detrimental effects of unstable fiber birefringence are overcome by employing the reference-frame-independent QKD protocol for polarization qubits in polarization maintaining fiber, where standard QKD protocols fail, as we show for comparison. This opens the way for quantum enhanced secure communications between companies and members of the general public equipped with handheld mobile devices, via telecom-fiber tethering.