Hypovitaminosis D in Chinese type 2 diabetes: lack of impact on clinical metabolic status and biomarkers of cellular inflammation

OBJECTIVE

Low vitamin D (25 OH vitamin D) is implicated in the development of diabetes and the metabolic syndrome. We examined whether hypovitaminosis D has a clinically significant impact on glycaemia, metabolic status and inflammatory markers in Chinese patients with established type 2 diabetes.

METHODS

Characteristics of 109 patients aged over 50 years were stratified by 25 OH vitamin D status. Patients identified as 25 OH vitamin D deficient (<or= 50 nmol/L) received cholecalciferol 2,000 IU daily for three months. Measurement of HbA1c, metabolic syndrome parameters, 25 OH vitamin D, calcium, phosphate, PTH, hsCRP and ferritin were taken at baseline and then 25 OH vitamin D, PTH, calcium, phosphate monthly for three months in those on replacement therapy.

RESULTS

Vitamin D deficiency was common, affecting 36% of patients. There was no impact of hypovitaminosis D on metabolic syndrome status, HbA1c or insulin use (p >or= 0.4 for all) and no association between 25OHVitD and ferritin or hsCRP (p >or= 0.3 for all). Neither BMI nor the metabolic syndrome affected the incremental rise in 25OHVitD levels during supplementation.

CONCLUSION

There is no relationship between hypovitaminosis D and metabolic control or inflammatory markers in established type 2 diabetes.This suggests that at least in Chinese populations, the effect of low vitamin D is not clinically significant once diabetes is established. Future 25OHVitD intervention trials should therefore focus on prevention in pre-diabetes.

Open reduction and internal fixation of proximal humeral fractures with use of the locking proximal humerus plate. Results of a prospective, multicenter, observational study

BACKGROUND

The treatment of unstable displaced proximal humeral fractures, especially in the elderly, remains controversial. The objective of the present prospective, multicenter, observational study was to evaluate the functional outcome and the complication rate after open reduction and internal fixation of proximal humeral fractures with use of a locking proximal humeral plate.

METHODS

One hundred and eighty-seven patients (mean age, 62.9 +/- 15.7 years) with an acute proximal humeral fracture were managed with open reduction and internal fixation with a locking proximal humeral plate. At the three-month, six-month, and one-year follow-up examinations, 165 (88%), 158 (84%), and 155 (83%) of the 187 patients were assessed with regard to pain, shoulder mobility, and strength. The Constant score was determined at each interval, and the Disabilities of the Arm, Shoulder and Hand (DASH) score was determined for the injured and contralateral extremities at the time of the one-year follow-up.

RESULTS

Between three months and one year, the mean range of motion and the mean Constant score for the injured shoulders improved substantially. Twelve months after surgery, the mean Constant score for the injured side was 70.6 +/- 13.7 points, corresponding to 85.1% +/- 14.0% of the score for the contralateral side. The mean DASH score at the time of the one-year follow-up was 15.2 +/- 16.8 points. Sixty-two complications were encountered in fifty-two (34%) of 155 patients at the time of the one-year follow-up. Twenty-five complications (40%) were related to incorrect surgical technique and were present at the end of the operative procedure. The most common complication, noted in twenty-one (14%) of 155 patients, was intraoperative screw perforation of the humeral head. Twenty-nine patients (19%) had an unplanned second operation within twelve months after the fracture.

CONCLUSIONS

Surgical treatment of displaced proximal humeral fractures with use of the locking proximal humeral plate that was evaluated in the present study can lead to a good functional outcome provided that the correct surgical technique is used. Because many of the complications were related to incorrect surgical technique, it behooves the treating surgeon to perform the operation correctly to avoid iatrogenic errors.

Vascular Pathology in Male Lewis Rats following Short-Term, Low-Dose Rotenone Administration

The long-term administration of low doses of rotenone has been used to produce a model of Parkinson disease (PD) in rats. However, only about 50% of similarly treated rats develop the PD-like syndrome, with many dying during the first few days of treatment. The lesions in male Lewis rats that became moribund or died after short-term, low-dose rotenone administration are described. Dosed rats had fibrinoid change and acute hemorrhage involving small arteries and arterioles of the brain and lungs. The thalamus, hypothalamus, and medulla oblongata were most frequently and severely affected. Blood vessels in the brain of some male Lewis rats appeared acutely susceptible to the effects of rotenone. Understanding the selective nature of the fibrinoid change and hemorrhage might explain how rotenone produces PD-like signs and lesions in rats, and it might also provide the basis for a model of intraparenchymal hemorrhagic cerebrovascular disease (i.e., hemorrhagic strokes) in humans.

Quantitative detection of cytokeratin 20 mRNA in urine samples as diagnostic tools for bladder cancer by real-time PCR

AIM

To determine and compare cytokeratin 20 (CK20) mRNA expression in urine of patients with transitional cell carcinomas of bladder (TCCB), urological benign diseases, and healthy volunteers.

METHODS

Taqman probe was designed according to the sequence of CK20 cloned gene. The quantitative PCR reaction system was optimized and evaluated. The CK20 mRNA level was screened by real-time polymerase chain reaction (RT-PCR) in 95 urine samples and analyzed according to the following parameters: urinary cytology, nuclear matrix protein 22 (NMP22) expression, tumor stage and grade.

RESULTS

For 60 TCCB patients urinary cytology was positive in 28 (46.7%), control group had no false-positive results (specificity 100%). CK20 expression was positive in RT-PCR of 51 cases (85%) of TCCB, but control group was positive in 2 cases (specificity 94.3%) with a cutoff value of crossover point (CT) = 30. Two methods have significant variation in sensitivity (p < 0.001), NMP22 expression was positive in 47 cases (78.3%), but control group was positive in 9 cases (specificity 85%). In the simultaneous evaluation of CK20 and NMP22 mRNA expression, there were 54 positive cases (90%). CK20 mRNA values in TCCB group (mean 27712.57 copies/microl) were significantly higher than in non-cancer disease urological group (mean 74.45 copies/microl) and control group (mean 8.47 copies/microl) (p < 0.001, p < 0.001, respectively). CK20 mRNA values increased gradually with higher tumor grade and stage: G1 differs significantly from G2 (p = 0.016); T(is) /T(a) differs significantly from T(1-2) (p = 0.022).

CONCLUSION

Our results indicate that CK20 mRNA expression could be regarded as a potential marker for TCCB. We demonstrated correlation between CK20 expression and the clinicopathologic features of TCCB (tumor stage and grade); simultaneous use of CK20 and NMP22 markers will elevate the sensitivity of the method. CK20 RT-PCR is a sensitive, quantitative, rapid and specific method to detect free cancer cells in the urine, and could be recommended for be wide application in the diagnostics of TCCB and evaluation of therapeutic effect.

A mechanical model of the human heart relating septal function to myocardial work and energy

A thorough understanding of ventricular interaction and the effects of septal function on right and left ventricular performance in the human heart requires measurement of interventricular pressure gradients using high fidelity pressure transducers. The advent of newer echocardiographic techniques provides an opportunity to combine high resolution images with bi-ventricular catheterization data in the cardiac catheterization laboratory, and obtain the detailed hemodynamic and echocardiographic information necessary to more fully understand the clinical manifestations of normal and abnormal septal and free wall mechanical function. We have anticipated these developments and modified the description of heart mechanics in our integrated multi-scale model of the human cardio-respiratory system (H-CRS) to closely analyze how the mechanical properties of the inter-ventricular septum affect the work, energy utilization, and oxygen consumption of the atria, ventricles, septum, and each ventricular free wall. Combined with the H-CRS model, these modifications allow one to observe how tissue properties of the septum affect the entire heart and circulation. For example, the normal septum transfers energy from the left to the right ventricle, and assists the pre-load of both, acting as a third pump. Diseases that increase septal elastance cause abnormalities resembling left ventricular diastolic dysfunction (LVDD), including a decrease in cardiac output and an increase in pulmonary pressures despite a normal left ventricular ejection fraction. Similar applications of the H-CRS model to other regional disorders such as hypertrophic obstructive cardiomyopathy and myocardial infarction might likewise allow one to study their clinical implications in greater detail.

Biologic diversity of polyomavirus BK genomic sequences: Implications for molecular diagnostic laboratories

Data on polyomavirus genomic diversity has greatly expanded in the past few years. The implications of viral DNA sequence variation on the performance of molecular diagnostic assays have not been systematically examined. 716 BK, 1626 JC, and 73 SV40 virus sequences available in GenBank were aligned using Clustal-X. Five different published BKV PCR assays currently in use at major medical centers were evaluated for primer and probe mismatches with available GenBank sequences. Coverage of naturally occurring BKV strains varied amongst different assay methods. Targeted viral sequences showed major mismatch with primer or probe sequence in up to 30.7% of known BKV strains. BKV subtypes IVa, IVb, and IVc were more prone to this problem, reflecting common use of Type I Dun sequence for assay design. Despite the known polymorphism of this gene, 484 VP-1 sequences with conserved areas potentially suitable for PCR assay design are available. Assay targets in the Large T-antigen and agnogene are less subject to genetic variation, but sequence information corresponding to the latter two genes is available only for 164 and 174 published strains, respectively. Cross reactivity of appropriately selected BKV primers with JCV and SV40 sequences available in current databases was not a significant problem.

Oncolytic virotherapy with an HSV amplicon vector expressing granulocyte–macrophage colony-stimulating factor using the replication-competent HSV type 1 mutant HF10 as a helper virus

Direct viral infection of solid tumors can cause tumor cell death, but these techniques offer the opportunity to express exogenous factors to enhance the antitumor response. We investigated the antitumor effects of a herpes simplex virus (HSV) amplicon expressing mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) using the replication-competent HSV type 1 mutant HF10 as a helper virus. HF10-packaged mGM-CSF-expressing amplicon (mGM-CSF amplicon) was used to infect subcutaneously inoculated murine colorectal tumor cells (CT26 cells) and the antitumor effects were compared to tumors treated with only HF10. The mGM-CSF amplicon efficiently replicated in CT26 cells with similar oncolytic activity to HF10 in vitro. However, when mice subcutaneously inoculated with CT26 cells were intratumorally injected with HF10 or mGM-CSF amplicon, greater tumor regression was seen in mGM-CSF amplicon-treated animals. Furthermore, mGM-CSF amplicon treatment prolonged mouse survival. Immunohistochemical analysis revealed increased inflammatory cell infiltration in the solid tumor in the mGM-CSF amplicon-treated animals. These results suggest that expression of GM-CSF enhances the antitumor effects of HF10, and HF10-packaged GM-CSF-expressing amplicon is a promising agent for the treatment of subcutaneous tumors.

Maternal mortality in Yunnan, China: recent trends and associated factors

OBJECTIVE

Yunnan Province, located in southwest China, is one of the poorest province in China. The maternal mortality ratio (MMR) is about twice the national average (56.2/100,000 live births), and in remote mountainous regions, the rate is five times higher. This study aimed to examine the progress in reduction of maternal mortality in the 1990s and early 2000s and the factors associated with this reduction in Yunnan.

DESIGN

A population-based, longitudinal, ecological correlation study.

SETTING

A remote province of China with a proportionately large indigenous population.

POPULATION

Populations at county, prefecture and provincial level.

METHODS

Using maternal mortality data collected at the province, prefecture/region and county levels, trend and time series analyses and multivariate linear regression analyses were performed using SPSS (Version 13).

MAIN OUTCOME MEASURE

MMR and its change over time.

RESULTS

MMR declined substantially in the 1990s at a rate of 3.0% per year. Utilisation of prenatal and obstetric care increased and was significantly correlated with the declining trend in MMR. Hospital delivery was a strong predictor of MMR, independent of social and economic development. Both low income and illiteracy were significantly associated with increased MMR.

CONCLUSIONS

Declines in maternal mortality in Yunnan over the past 14 years appear to reflect health, social and economic interventions implemented in the 1990s. The association of hospital delivery with maternal mortality may be due to the effective management of severe pregnancy and birth complications. Low income and illiteracy were associated with MMR but primarily through their impact on the use of prenatal and obstetric care.

Generation of shock-free pressure waves in shaped resonators by boundary driving

Investigation of high amplitude pressure oscillations generated by boundary driving in shaped resonators has been carried out both theoretically and experimentally. In the theoretical modeling, the acoustic resonance in an axisymmetric resonator is studied by the Galerkin method. The resonator is exponentially expanded and the boundary driving is provided by a piston at one end. The pressure wave forms, amplitudes, resonance frequencies, and ratio of pressures at the two ends of the resonator are calculated for various expansion flare constants and driving strengths. These results are partially compared with those generated by shaking the resonator. They are also verified in the experiment, in which an exponentially expanded resonator is connected to a speaker box functioning as the piston. The experiment is further extended to a horn-shaped resonator with a rectangular cross section. The boundary driving in this case is generated by a circular piezoelectric disk, which forms one sidewall of the resonator cavity. The characteristics of axisymmetric resonators, such as the resonance frequency and amplitude ratio of pressures at the two ends, are observed in this low aspect ratio rectangular resonator with the sidewall driving.

Polymorphism of Growth-Correlated Genes Associated with Fatness and Muscle Fiber Traits in Chickens

Thirty single nucleotide polymorphisms (SNP) and one 6-bp insertion-deletion (indel) from 8 genes of somatotropic axis were used to study the association with chicken fatness and muscle fibers. The allele frequency difference between Xinghua and White Plymouth Rock chickens was observed, and their effects on fatness and muscle fiber traits were also evaluated by linkage analyses. The G143831A (G+1705A) SNP of the growth hormone (GH) gene was related to fat width, and the G144762A (G+119A) SNP of the GH gene was significantly associated with abdominal fat pad weight, abdominal fat pad ratio, and crude fatty content of the breast muscle. The 6-bp indel of the growth hormone secretagogue receptor (GHSR) gene was significantly linked with the fat traits. The C51978309T SNP of the insulin-like factor-I (IGF-I) gene was significantly linked with the transversal area of the leg muscle fiber and transversal area of the breast muscle fiber. There was significant linkage between the insulin (INS) gene and 2 traits of the transversal area of transversal area of the leg muscle fiber and transversal area of the breast muscle fiber. Association of 30 SNP and one 6-bp indel from 8 genes of somatotropic axis with chicken fatness and muscle fiber traits was analyzed in the present study. The GH, GHSR, and leptin receptor genes were significantly related to chicken fatness. The INS and IGF-I genes were linked with muscle fiber density. Therefore, the genes of somatotropic axis not only affected chicken growth and body composition but also were associated with fatness and muscle fiber traits.

Using a Human Cardiopulmonary Model to Study and Predict Normal and Diseased Ventricular Mechanics, Septal Interaction, and Atrio-Ventricular Blood Flow Patterns

We upgraded our human cardiopulmonary (CP) model with additional data that enables it to more accurately simulate normal physiology. We then tested its ability to explain human disease by changing two parameter values that decrease ventricular compliance, and found that it could predict many of the hemodynamic, gas exchange, and autonomic abnormalities found in patients with left ventricular diastolic dysfunction (LVDD). The newly incorporated information includes high-fidelity pressure tracings simultaneously recorded from the RV and LV of a normal human in a cardiac catheterization laboratory, Doppler echocardiographic inlet flow velocity patterns, measures of right and left ventricular impedance, and atrial volumes. The revised cardiovascular section details the hemodynamics of a normal subject to the extent that it can now explain the effects of septal compliance on ventricular interaction, the differences in left and right ventricular pressure development, and venous blood gas mixing in the right atrium. The model can isolate the highly interrelated features of normal and abnormal physiology, and simultaneously demonstrate their interaction in a manner that would be very difficult or impossible using an intact organism. It may therefore help physicians and scientists understand, diagnose, and improve their treatment of complicated cardiovascular and pulmonary diseases. It could also simulate the hemodynamic and respiratory effects of ventricular and pulmonary assist devices, and thus help with their development.

TNF-alpha downregulates the leukotriene C4 synthase gene in mononuclear phagocytes

We studied the effect of tumor necrosis factor (TNF)-alpha exposure on cysteinyl leukotriene (LT) synthesis by cells of monocyte/macrophage lineage. TNF-alpha conditioning of monocytic THP-1 cells and primary human monocytes resulted in a decreased capacity for LTC(4) release. TNF-alpha exposure (for 16-24 h) decreased LTC(4) synthase mRNA in THP-1 cells, primary mouse bone marrow-derived macrophages, and eosinophilic AML14.3D10 cells. TNF-alpha downregulated LTC(4) synthase mRNA in THP-1 cells in a dose- and time-dependent manner, with downregulation observed as early as 4 h. The effect of TNF-alpha on LTC(4) synthase mRNA expression was mediated via the MEK/ERK pathway, but not via cyclooxygenase or nitric oxide synthase pathways. Conditioning of actinomycin D-treated cells with TNF-alpha did not accelerate degradation of LTC(4) synthase mRNA. TNF-alpha produced sustained activation of p50 and p65, which were previously reported by our group to decrease LTC(4) synthase promoter activity. In transiently transfected THP-1 cells, TNF-alpha decreased promoter activity via an element located within the first 620 bp of the promoter. We conclude that TNF-alpha exposure downregulates the synthetic capacity for cysteinyl LT release and LTC(4) synthase gene expression in monocytes/macrophages via a transcriptional mechanism.

Oculomotor plasticity during vestibular compensation does not depend on cerebellar LTD

Vestibular paradigms are widely used for investigating mechanisms underlying cerebellar motor learning. These include adaptation of the vestibuloocular reflex (VOR) after visual-vestibular mismatch training and vestibular compensation after unilateral damage to the vestibular apparatus. To date, various studies have shown that VOR adaptation may be supported by long-term depression (LTD) at the parallel fiber to Purkinje cell synapse. Yet it is unknown to what extent vestibular compensation may depend on this cellular process. Here we investigated adaptive gain changes in the VOR and optokinetic reflex during vestibular compensation in transgenic mice in which LTD is specifically blocked in Purkinje cells via expression of a peptide inhibitor of protein kinase C (L7-PKCi mutants). The results demonstrate that neither the strength nor the time course of vestibular compensation are affected by the absence of LTD. In contrast, analysis of vestibular compensation in spontaneous mutants that lack a functional olivo-cerebellar circuit (lurchers) shows that this form of motor learning is severely impaired. We conclude that oculomotor plasticity during vestibular compensation depends critically on intact cerebellar circuitry but not on the occurrence of cerebellar LTD.

A macrophage cell model for pH and volume regulation

A whole-cell model of a macrophage (mphi) is developed to simulate pH and volume regulation during a NH4Cl prepulse challenge. The cell is assumed spherical, with a plasma membrane that separates the cytosolic and extracellular bathing media. The membrane contains background currents for Na+, K+ and Cl-, a Na(+)-K+ pump, a V-type H(+)-extruder (V-ATPase), and a leak pathway for NH4+. Cell volume is controlled by instantaneous osmotic balance between cytosolic and extracellular osmolytes. Simulations reveal that the mphi model can mimic alterations in measured pH(i) and cell volume (Vol(i)) data during and after delivery of an ammonia prepulse, which induces an acid load within the cell. Our analysis indicates that there are substantial problems in quantifying transporter-mediated H+ efflux solely from experimental observations of pH(i) recovery, as is commonly done in practice. Problems stemming from the separation of effects arise, since there is residual NH4+ dissociation to H+ inside the mphi during pH(i) recovery, as well as, proton extrusion via the V-ATPase. The core assumption of conventional measurement techniques used to estimate the H+ extrusion current (I(H)) is that the recovery phase is solely dependent on transporter-mediated H+ extrusion. However, our model predictions suggest that there are major problems in using this approach, due to the complex interactions between I(H), NH3/NH4+ buffering and NH3/NH4+ efflux during the active acid extrusion phase. That is, the conventional buffer capacity-based I(H) estimation must also take into account the perturbation that a prepulse challenge brings to the cytoplasmic acid buffer itself. The importance of this whole-cell model of mphipH(i) and volume regulation lies in its potential for extension to the characterization of several other types of non-excitable cells, such as the microglia (brain macrophage) and the T-lymphocyte.

High Diversity of the Chicken Growth Hormone Gene and Effects on Growth and Carcass Traits

The chicken growth hormone (cGH) gene plays a crucial role in controlling growth and metabolism, leading to potential correlations between cGH polymorphisms and economic traits. In this study, DNA from four divergent chicken breeds were screened for single nucleotide polymorphisms (SNPs) in the cGH gene using denaturing high-performance liquid chromatography and sequencing. A total of 46 SNPs were identified, of which 4 were in the 5' untranslated region, 1 in the 3' untranslated region, 5 in exons (two of which are nonsynonymous), with the remaining 36 in introns. The nucleotide diversity in the cGH gene ( theta = 2.7 x 10(-3)) was higher than that reported for other chicken genes, even within the same breeds. The associations of five of these SNPs and their haplotypes with chicken growth and carcass traits were determined using polymerase chain reaction-restriction fragment length polymorphism analysis in a F2 resource population cross of two of the four chicken breeds (White Recessive Rock and Xinghua). This analysis shows that, among other correlations, G+1705A was significantly associated with body weight at all ages measured, shank length at three of four ages measured, and average daily gain within weeks 0 to 4. Thus, this cGH polymorphism, or another polymorphism that is in linkage disequilibrium with G+1705A, appears to correspond to a significant growth-related quantitative trait locus difference between the two breeds used to construct the resource population.

Measurement of dijet azimuthal decorrelations at central rapidities in pp collisions at sqrt s =1.96 TeV

Correlations in the azimuthal angle between the two largest transverse momentum jets have been measured using the D0 detector in p (-)p collisions at a center-of-mass energy sqrt[s]=1.96 TeV. The analysis is based on an inclusive dijet event sample in the central rapidity region corresponding to an integrated luminosity of 150 pb(-1). Azimuthal correlations are stronger at larger transverse momenta. These are well described in perturbative QCD at next-to-leading order in the strong coupling constant, except at large azimuthal differences where contributions with low transverse momentum are significant.

Increased noise level of purkinje cell activities minimizes impact of their modulation during sensorimotor control

While firing rate is well established as a relevant parameter for encoding information exchanged between neurons, the significance of other parameters is more conjectural. Here, we show that regularity of neuronal spike activities affects sensorimotor processing in tottering mutants, which suffer from a mutation in P/Q-type voltage-gated calcium channels. While the modulation amplitude of the simple spike firing rate of their floccular Purkinje cells during optokinetic stimulation is indistinguishable from that of wild-types, the regularity of their firing is markedly disrupted. The gain and phase values of tottering's compensatory eye movements are indistinguishable from those of flocculectomized wild-types or from totterings with the flocculus treated with P/Q-type calcium channel blockers. Moreover, normal eye movements can be evoked in tottering when the flocculus is electrically stimulated with regular spike trains mimicking the firing pattern of normal simple spikes. This study demonstrates the importance of regularity of firing in Purkinje cells for neuronal information processing.

Increased production of reactive oxygen species contributes to motor neuron death in a compression mouse model of spinal cord injury

STUDY DESIGN

Experimental laboratory investigation of the role and pathways of reactive oxygen species (ROS)-mediated motor neuron cell death in a mouse model of compression spinal cord injury.

OBJECTIVES

To analyze ROS-mediated oxidative stress propagation and signal transduction leading to motor neuron apoptosis induced by compression spinal cord injury.

SETTING

University of Louisville Health Science Center.

METHODS

Adult C57BL/6J mice and transgenic mice overexpressing SOD1 were severely lesioned at the lumbar region by compression spinal cord injury approach. Fluorescent oxidation, oxidative response gene expression and oxidative stress damage markers were used to assay spinal cord injury-mediated ROS generation and oxidative stress propagation. Biochemical and immunohistochemical analyses were applied to define the ROS-mediated motor neuron apoptosis resulted from compression spinal cord injury.

RESULTS

ROS production was shown to be elevated in the lesioned spinal cord as detected by fluorescent oxidation assays. The early oxidative stress response markers, NF-kappaB transcriptional activation and c-Fos gene expression, were significantly increased after spinal cord injury. Lipid peroxidation and nucleic acid oxidation were also elevated in the lesioned spinal cord and motor neurons. Cytochrome c release, caspase-3 activation and apoptotic cell death were increased in the spinal cord motor neuron cells after spinal cord injury. On the other hand, transgenic mice overexpressing SOD1 showed lower levels of steady-state ROS production and reduction of motor neuron apoptosis compared to that of control mice after spinal cord injury.

CONCLUSION

These data together provide direct evidence to demonstrate that the increased production of ROS is an early and likely causal event that contributes to the spinal cord motor neuron death following spinal cord injury. Thus, antioxidants/antioxidant enzyme intervention combined with other therapy may provide an effective approach to alleviate spinal cord injury-induced motor neuron damage and motor dysfunction.

The accuracy of dynamic wedge dose computation in the ADAC Pinnacle RTP system

The nonphysical wedge is a modality that uses computer‐controlled jaw motion to generate wedge‐shaped dose distributions. There are Varian enhanced dynamic wedges (EDWs) and Siemens virtual wedges (VWs). We recently commissioned dynamic wedges on both Varian and Siemens LINACs. The beam data, acquired with a Wellhöfer chamber array and a Sun Nuclear profiler, are used for modeling in the ADAC Pinnacle system. As recommended by ADAC, only a limited number of beam data is measured and used for beam modeling. Therefore, the dose distributions of dynamic wedges generated by Pinnacle must be examined. Following the commissioning of the dynamic wedges, we used Pinnacle to generate a number of dose distributions with different energies, wedge angles, field sizes, and depths. The computed data from Pinnacle are then compared with the measured data.

The deviations of the output factor in all square and rectangular fields are mostly within 2.0% for both EDW and VW. For asymmetric fields, the deviations are within 3%. However, exceptions of differences more than 3% have been found in a larger field and large wedge combinations. The precision of the beam profiles generated by Pinnacle is also evaluated. As a result of this investigation, we present a scope of quality assurance tests that are necessary to ensure acceptable consistency between the delivered dose and the associated treatment plan when dynamic wedges are applied.

PACS numbers: 8753 Dq, 87.53.Xd

Recovery of hippocampal cell proliferation and BDNF levels, both of which are reduced by repeated restraint stress, is accelerated by chronic venlafaxine

The present study investigated the poststress (PS) cellular and molecular changes in the hippocampus of rats subjected to repeated restraint stress (RS) and the effects of chronic administration of an antidepressant drug, venlafaxine, on these changes. It was found that RS suppressed hippocampal cell proliferation, decreased brain-derived neurotrophic factor (BDNF) levels, and increased both the levels of copper/zinc superoxide dismutase (Cu/Zn-SOD) and the number of Cu/Zn-SOD immunostained hippocampal interneurons. In venlafaxine-treated rats, the changes in cell proliferation, BDNF levels, and the number of Cu/Zn-SOD interneurons returned to control levels on PS Days 21, 14, 7, respectively. In vehicle-injected rats, BDNF and the number of Cu/Zn-SOD interneurons returned to control levels on PS Days 21 and 14, respectively, but cell proliferation was still suppressed on PS Day 21. The stress-induced elevation of Cu/Zn-SOD protein remained during the 3-week PS period, and it was further increased by about 20% after 3 weeks of venlafaxine administration.

Search for supersymmetry with gauge-mediated breaking in diphoton events at D0

We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest SUSY particle.

Measurement of the B0s lifetime in the exclusive decay channel B0s-->J/psiphi

Using the exclusive decay B0s-->J/psi(mu+mu-)phi(K+K-), we report the most precise single measurement of the B0s lifetime. The data sample corresponds to an integrated luminosity of approximately 220 pb(-1) collected with the D0 detector at the Fermilab Tevatron Collider in 2002-2004. We reconstruct 337 signal candidates, from which we extract the B0s lifetime, tau(B0s)=1.444(+0.098)(-0.090)(stat)+/-0.020(sys) ps. We also report a measurement for the lifetime of the B0 meson using the exclusive decay B0-->J/psi(mu+mu-)K*0(892)(K+pi-). We reconstruct 1370 signal candidates, obtaining tau(B0)=1.473(+0.052)(-0.050)(stat)+/-0.023(sys) ps, and the ratio of lifetimes, tau(B0s)/tau(B0)=0.980(+0.076)(-0.071)(stat)+/-0.003(sys).

Effect of resonator dimensions on nonlinear standing waves

An investigation of the effect of resonator dimensions on nonlinear standing waves in shaped resonators is conducted. Simple forms of the shear viscosity term in the momentum equations are developed for an axisymmetric (2D) resonator and a low aspect ratio rectangular (3D) resonator. The cross sections of the resonators are exponentially expanded and the one-dimensional wave equations are solved by using the Galerkin's method. The quality factors, pressure waveforms, compression ratios, and resonance frequencies are calculated for different dimensionless cross sections and lengths of the resonators. The results show that, apart from the resonator length, the ratio of the cross-section dimension to the length of the resonator is an important parameter. If the ratio is greater than 0.04, the characteristics of the shaped resonator are not affected significantly. However, when the ratio is less than 0.01, the resonance becomes weak, the compression ratio drops substantially, and the frequency response changes as well.

Observation and properties of the X(3872) decaying to J/psipi(+)pi(-) in pp collisions at sqrt[s]=1.96 TeV

We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in pp collisions at sqrt[s]=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state.

Search for doubly charged higgs boson pair production in the decay to mu(+)mu(+)mu(-)mu(-) in pp collisions at sqrt[s]=1.96 TeV

A search for pair production of doubly charged Higgs bosons in the process pp -->H(++)H(--) -->mu(+)mu(+)mu(-)mu(-) is performed with the D0 run II detector at the Fermilab Tevatron. The analysis is based on a sample of inclusive dimuon data collected at an energy of sqrt[s]=1.96 TeV, corresponding to an integrated luminosity of 113 pb(-1). In the absence of a signal, 95% confidence level mass limits of M(H(+/-+/-)(L))>118.4 GeV/c(2) and M(H(+/-+/-)(R))>98.2 GeV/c(2) are set for left-handed and right-handed doubly charged Higgs bosons, respectively, assuming 100% branching into muon pairs.

A precision measurement of the mass of the top quark

The standard model of particle physics contains parameters--such as particle masses--whose origins are still unknown and which cannot be predicted, but whose values are constrained through their interactions. In particular, the masses of the top quark (M(t)) and W boson (M(W)) constrain the mass of the long-hypothesized, but thus far not observed, Higgs boson. A precise measurement of M(t) can therefore indicate where to look for the Higgs, and indeed whether the hypothesis of a standard model Higgs is consistent with experimental data. As top quarks are produced in pairs and decay in only about 10(-24) s into various final states, reconstructing their masses from their decay products is very challenging. Here we report a technique that extracts more information from each top-quark event and yields a greatly improved precision (of +/- 5.3 GeV/c2) when compared to previous measurements. When our new result is combined with our published measurement in a complementary decay mode and with the only other measurements available, the new world average for M(t) becomes 178.0 +/- 4.3 GeV/c2. As a result, the most likely Higgs mass increases from the experimentally excluded value of 96 to 117 GeV/c2, which is beyond current experimental sensitivity. The upper limit on the Higgs mass at the 95% confidence level is raised from 219 to 251 GeV/c2.

Search for narrow tt resonances in pp collisions at square root of (s)=1.8 TeV

A search for narrow resonances that decay into tt pairs has been performed using 130 pb(-1) of data in the lepton + jets channel collected by the Dphi detector in pp collisions at square root of (s)=1.8 TeV. There is no significant deviation observed from the standard-model predictions at a top-quark mass of 175 GeV/c2. We therefore present upper limits at the 95% confidence level on the product of the production cross section and branching fraction to tt for narrow resonances as a function of the resonance mass MX. These limits are used to exclude the existence of a leptophobic top-color particle with mass MX<560 GeV/c2, using a theoretical cross section for a width GammaX=0.012MX.

Anomalous dispersion relations by symmetry breaking in axially uniform waveguides

We show that modes of axially uniform waveguides of arbitrary cross section can be made to have anomalous dispersion relations resulting from strong repulsion between two modes. When the axial wave vector k is 0, the two modes have different TE/TM symmetry and thus can be brought arbitrarily close to an accidental frequency degeneracy. For nonzero k, the symmetry is broken causing the modes to repel. When the modes are sufficiently close together this repulsion leads to unusual features such as extremely flattened dispersion relations, backward waves, zero group velocity for nonzero k, atypical divergence of the density of states, and nonzero group velocity at k=0.

Increased oxidative stress is associated with chronic intermittent hypoxia-mediated brain cortical neuronal cell apoptosis in a mouse model of sleep apnea

Chronic intermittent hypoxia (CIH), as occurs in obstructive sleep apnea (SA), is associated with substantial cortico-hippocampal damage leading to impairments of neurocognitive, respiratory and cardiovascular functions. Previous studies in a rat model have shown that CIH increases brain cortical neuronal cell death. However, the molecular events leading to CIH-mediated neuronal cell death remain largely undefined. The oscillation of O2 concentrations during CIH remarkably mimics the processes of ischemia/re-oxygenation and could therefore increase cellular production of reactive oxygen species (ROS). We extended the CIH paradigm to a mouse model of SA to identify the molecular mechanisms underlying cortical neuronal cell death. A significant increase of ROS production in mouse brain cortex and cortical neuronal cells was detected by fluorescent oxidation assays upon exposure of mice to CIH, followed by increased expression of oxidative stress response markers, c-Fos, c-Jun and NF-kappaB in mouse brain cortex, as revealed by immunohistochemical and LacZ reporter assays respectively. Long-term exposure of mice to CIH increased the levels of protein oxidation, lipid peroxidation and nucleic acid oxidation in mouse brain cortex. Furthermore, exposure of mice to CIH induced caspase-3 activation and increased some cortical neuronal cell apoptosis. On the other hand, transgenic mice overexpressing Cu,Zn-superoxide dismutase exposed to CIH conditions had a lower level of steady-state ROS production and reduced neuronal apoptosis in brain cortex compared with that of normal control mice. Taken together, these findings suggest that the increased ROS production and oxidative stress propagation contribute, at least partially, to CIH-mediated cortical neuronal apoptosis and neurocognitive dysfunction.

A novel applicator for low-dose-rate brachytherapy of gynecological cancers

The standard low-dose-rate (LDR) delivery system utilized in the definitive management of patients with cervical carcinoma involves an intrauterine tandem and a pair of vaginal colpostats (ovoids). This well-known application system may deliver inadequate dosage if the tumor extends to the lower vaginal mucosa. During the gauze packing of the ovoids, either operator error or narrowing of the vaginal apex can result in mal-alignment of the colpostats and subsequent inadequate dosing to the ecto-cervix. A novel vaginal cylinder has been designed to address these concerns. Beginning January 1, 2001, patients with cancer of the cervix, endometrium, or vagina requiring LDR brachytherapy have been enrolled into an institutionally sanctioned clinical trial. As of May 31, 2001, a total of 11 patients have been entered but only 10 were successfully implanted with the test device. Patient follow-up has ranged from 0.81 years to 1.2 years (median: 0.96 years). Using our study applicator, all patients received within 10% of the preimplant prescribed dose to tumor. Also, no one had cumulative dosage that exceeded 10% of the maximum allowed dose to the critical normal tissues. Thus far, all study patients have had no clinical evidence of persistence/recurrence of disease or complications from treatment. The preliminary results presented herein clearly demonstrate the feasibility of this novel LDR vaginal cylinder in the treatment of a variety of clinical situations involving gynecological cancers. Our institutional trial is continuing.

Search for large extra dimensions in the monojet+E(T) channel with the DØ detector

We present a search for large extra dimensions (ED) in pp collisions at a center-of-mass energy of 1.8 TeV using data collected by the DØ detector at the Fermilab Tevatron in 1994-1996. Data corresponding to 78.8+/-3.9 pb(-1) are examined for events with large missing transverse energy, one high-p(T) jet, and no isolated muons. There is no excess observed beyond expectation from the standard model, and we place lower limits on the fundamental Planck scale of 1.0 and 0.6 TeV for 2 and 7 ED, respectively.

Diploid-dependent regulation of gene expression: a genetic cause of abnormal development in fish haploid embryos

A diploid-dependent regulatory mechanism of gene expression for spatial patterning of the eye in vertebrates has been determined by analyzing the phenotypes of haploid goldfish embryos. There are two gene loci in charge of eye spatial patterning during embryonic morphogenesis. The expressional probability for each copy of the two genes in a set of chromosomes is 50%. A pair of genes in two sets of homologous or heterologous chromosomes is 100% and essential for normal gene expression. The haploid condition itself would result in the obstruction of gene expression and abnormal development because the diploid-dependent regulatory apparatus will regulate gene expression in a haploid embryo according to the same rule as in the diploid embryo.

A novel applicator for low-dose-rate brachytherapy of gynecological cancers

The standard low-dose-rate (LDR) delivery system utilized in the definitive management of patients with cervical carcinoma involves an intrauterine tandem and a pair of vaginal colpostats (ovoids). This well-known application system may deliver inadequate dosage if the tumor extends to the lower vaginal mucosa. During the gauze packing of the ovoids, either operator error or narrowing of the vaginal apex can result in mal-alignment of the colpostats and subsequent inadequate dosing to the ecto-cervix. A novel vaginal cylinder has been designed to address these concerns. Beginning January 1, 2001, patients with cancer of the cervix, endometrium, or vagina requiring LDR brachytherapy have been enrolled into an institutionally sanctioned clinical trial. As of May 31, 2001, a total of 11 patients have been entered but only 10 were successfully implanted with the test device. Patient follow-up has ranged from 0.81 years to 1.2 years (median: 0.96 years). Using our study applicator, all patients received within 10% of the preimplant prescribed dose to tumor. Also, no one had cumulative dosage that exceeded 10% of the maximum allowed dose to the critical normal tissues. Thus far, all study patients have had no clinical evidence of persistence/recurrence of disease or complications from treatment. The preliminary results presented herein clearly demonstrate the feasibility of this novel LDR vaginal cylinder in the treatment of a variety of clinical situations involving gynecological cancers. Our institutional trial is continuing.

Search for the production of single sleptons through R-parity violation in pp; collisions at square root (s) =1.8 TeV

We report the first search for supersymmetric particles via s-channel production and decay of smuons or muon sneutrinos at hadronic colliders. The data for the two-muon and two-jets final states were collected by the D0 experiment and correspond to an integrated luminosity of 94+/-5 pb(-1). Assuming that R parity is violated via the single coupling lambda'211, the number of candidate events is in agreement with expectation from the standard model. Exclusion contours are given in the (m(0),m(1/2)) and (m(x),m(v)) planes for lambda(')(211)=0.09, 0.08, and 0.07.

Motor performance and motor learning in Lurcher mice

In adult Lurcher mice virtually all cerebellar Purkinje cells have degenerated as a direct consequence of mutant gene action, providing a natural model for studying the effect of cerebellar cortical lesions on the generation of compensatory eye movements. Lurcher mice possess both optokinetic (OKR) and vestibular (VOR) compensatory reflexes. However, clear differences were observed in control of the OKR consisting of a large reduction in gain and a moderate increase in phase lag. Minor differences were also observed in the VOR in that gain and phase lead of the reflex were both increased in Lurcher animals. Subjecting Lurcher animals to eight days of visuovestibular training tested the assumption that increased VOR gain reflected an adaptive mechanism within remaining brainstem oculomotor pathways to compensate for the reduced OKR. Contrary to control animals, Lurcher animals were unable to modify either VOR or OKR in the course of training and therefore confirmed that an intact cerebellum is indispensable for the implementation of adaptive modifications to the oculomotor system.