bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-fatal horse related injuries treated in emergency departments in the United States, 2001–2003
Authors: Thomas K E , Annest J L , Gilchrist J , Bixby-Hammett D M
Published: April 2006

Objective:To characterise and provide nationally representative estimates of persons with non-fatal horse related injuries treated in American emergency departments.

Methods:The National Electronic Injury Surveillance System All Injury Program (NEISS–AIP) is a stratified probability sample comprising 66 hospitals. Data on injuries treated in these emergency departments are collected and reported. NEISS–AIP data on all types (horseback riding and otherwise) of non-fatal horse related injuries from 2001 to 2003 were analysed.

Results:An estimated 102 904 persons with non-fatal horse related injuries (35.7 per 100 000 population) were treated in American emergency departments each year from 2001 to 2003 inclusive. Non-fatal injury rates were higher for females (41.5 per 100 000) than for males (29.8 per 100 000). Most patients were injured while mounted on a horse (66.1%), commonly from falling or being thrown by the horse; while not mounted, injuries most often resulted from being kicked by the horse. The body parts most often injured were the head/neck region (23.2%), lower extremity (22.2%), and upper extremity (21.5%). The most common principal diagnoses were contusions/abrasions (31.4%) and fractures (25.2%). For each year that was studied, an estimated 11 502 people sustained traumatic brain injuries from horse related incidents. Overall, more than 11% of those injured were admitted to hospital.

Conclusions:Horse related injuries are a public health concern not just for riders but for anyone in close contact with horses. Prevention programmes should target horseback riders and horse caregivers to promote helmet use and educate participants about horse behaviour, proper handling of horses, and safe riding practices.
Aerobic capacity and peak power output of elite quadriplegic games players
Authors: Goosey-Tolfrey V , Castle P , Webborn N
Published: April 2006

Background:Participation in wheelchair sports such as tennis and rugby enables people with quadriplegia to compete both individually and as a team at the highest level. Both sports are dominated by frequent, intermittent, short term power demands superimposed on a background of aerobic activity.

Objective:To gain physiological profiles of highly trained British quadriplegic athletes, and to examine the relation between aerobic and sprint capacity.

Methods:Eight male quadriplegic athletes performed an arm crank exercise using an ergometer fitted with a Schoberer Rad Messtechnik (SRM) powermeter. The sprint test consisted of three maximum-effort sprints of five seconds duration against a resistance of 2%, 3%, and 4% of body mass. The highest power output obtained was recorded (PPO). Peak oxygen consumption (V̇o2peak), peak heart rate (HRpeak), and maximal power output (POaer) were determined.

Results:Mean POaerwas 67.7 (16.2) W, mean V̇o2peakwas 0.96 (0.17) litres/min, and HRpeakwas 134 (19) beats/min for the group. There was high variability among subjects. Peak power over the five second sprint for the group was 220 (62) W. There was a significant correlation between V̇o2peak(litres/min) and POaer(W) (r =  0.74, p<0.05).

Conclusions:These British quadriplegic athletes have relatively high aerobic fitness when compared with the available literature. Moreover, the anaerobic capacity of these athletes appeared to be relatively high compared with paraplegic participants.
ABCA1 mediates high-affinity uptake of 25-hydroxycholesterol by membrane vesicles and rapid efflux of oxysterol by intact cells
Authors: Tam Shui-Pang , Mok Leo , Chimini Giovanna , Vasa Monika , Deeley Roger G.
Published: April 2006

ATP Binding Cassette (ABC) transporter, ABCA1, plays a pivotal role in reverse cholesterol transport by mediating the cellular efflux of phospholipid and cholesterol. Studies using intact cells strongly suggest that ABCA1 acts as a phospholipid floppase, but there has been no direct demonstration that the protein is a primary active sterol transporter. Using membrane vesicles from insect Sf21 cells, we found that ABCA1 mediated ATP-dependent uptake of [3H]25-hydroxycholesterol with an apparent Km of 0.7 μM. Consistent with this high apparent affinity, expression of ABCA1 in human embryonic kidney cells both increased rapid efflux of 25-hydroxcholesterol and prevented oxysterol-mediated repression of low-density lipoprotein (LDL) receptor and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase mRNAs. Comparison of wild-type and ABCA1−/− murine fibroblasts indicates that 25-hydroxycholesterol is effluxed ∼5-fold more rapidly by wild-type cells. In addition, the rate of efflux from the wild-type but not the ABCA1−/− fibroblasts is increased a further twofold by inducers of ABCA1 expression. Thus under the experimental conditions employed, endogenous ABCA1 is a major contributor to 25-hydroxycholesterol efflux from wild-type fibroblasts. Evidence from in vitro studies indicates that oxysterols are potent inducers of genes involved in cellular cholesterol efflux and metabolism, including the ABCA1 gene, and repressors of genes involved in cholesterol synthesis or uptake. Our observations raise the possibility that efflux of oxysterols by ABCA1 could contribute to a homeostatic mechanism, which both attenuates oxysterol-induced expression of its cognate gene and alleviates repression of genes encoding proteins, such as HMG-CoA reductase and LDL receptor.
Adenosine downregulates DPPIV on HT-29 colon cancer cells by stimulating protein tyrosine phosphatase(s) and reducing ERK1/2 activity via a novel pathway
Authors: Tan Ernest Y. , Richard Cynthia L. , Zhang Hong , Hoskin David W. , Blay Jonathan
Published: April 2006

The multifunctional cell-surface protein dipeptidyl peptidase IV (DPPIV/CD26) is aberrantly expressed in many cancers and plays a key role in tumorigenesis and metastasis. Its diverse cellular roles include modulation of chemokine activity by cleaving dipeptides from the chemokine NH2-terminus, perturbation of extracellular nucleoside metabolism by binding the ecto-enzyme adenosine deaminase, and interaction with the extracellular matrix by binding proteins such as collagen and fibronectin. We have recently shown that DPPIV can be downregulated from the cell surface of HT-29 colorectal carcinoma cells by adenosine, which is a metabolite that becomes concentrated in the extracellular fluid of hypoxic solid tumors. Most of the known responses to adenosine are mediated through four different subtypes of G protein-coupled adenosine receptors: A1, A2A, A2B, and A3. We report here that adenosine downregulation of DPPIV from the surface of HT-29 cells occurs independently of these classic receptor subtypes, and is mediated by a novel cell-surface mechanism that induces an increase in protein tyrosine phosphatase activity. The increase in protein tyrosine phosphatase activity leads to a decrease in the tyrosine phosphorylation of ERK1/2 MAP kinase that in turn links to the decline in DPPIV mRNA and protein. The downregulation of DPPIV occurs independently of changes in the activities of protein kinases A or C, phosphatidylinositol 3-kinase, other serine/threonine phosphatases, or the p38 or JNK MAP kinases. This novel action of adenosine has implications for our ability to manipulate adenosine-dependent events within the solid tumor microenvironment.
Translocon pores in the endoplasmic reticulum are permeable to small anions
Authors: Lizák Beáta , Czegle Ibolya , Csala Miklós , Benedetti Angelo , Mandl József , Bánhegyi Gábor
Published: April 2006

Contribution of translocon peptide channels to the permeation of low molecular mass anions was investigated in rat liver microsomes. Puromycin, which purges translocon pores of nascent polypeptides, creating additional empty pores, raised the microsomal uptake of radiolabeled UDP-glucuronic acid, while it did not increase the uptake of glucose-6-phosphate or glutathione. The role of translocon pores in the transport of small anions was also investigated by measuring the effect of puromycin on the activity of microsomal enzymes with intraluminal active sites. The mannose-6-phosphatase activity of glucose-6-phosphatase and the activity of UDP-glucuronosyltransferase were elevated upon addition of puromycin, but glucose-6-phosphatase and β-glucuronidase activities were not changed. The increase in enzyme activities was due to a better access of the substrates to the luminal compartment rather than to activation of the enzymes. Antibody against Sec61 translocon component decreased the activity of UDP-glucuronosyltransferase and antagonized the effect of puromycin. Similarly, the addition of the puromycin antagonist anisomycin or treatments of microsomes, resulting in the release of attached ribosomes, prevented the puromycin-dependent increase in the activity. Mannose-6-phosphatase and UDP-glucuronosyltransferase activities of smooth microsomal vesicles showed higher basal latencies that were not affected by puromycin. In conclusion, translationally inactive, ribosome-bound translocons allow small anions to cross the endoplasmic reticulum membrane. This pathway can contribute to the nonspecific substrate supply of enzymes with intraluminal active centers.
Gene silencing of myostatin in differentiation of chicken embryonic myoblasts by small interfering RNA
Authors: Sato Fuminori , Kurokawa Masatoshi , Yamauchi Nobuhiko , Hattori Masa-aki
Published: April 2006

Myostatin (GDF-8) is known to negatively regulate skeletal muscle mass in myogenesis, but few studies have been conducted on the function of endogenous GDF-8 in primary myoblasts. The present study was performed to assess the function of GDF-8 by RNA interference using primary culture of chicken embryonic myoblasts in which myoblasts were differentiated into myotubes. An active form of small interfering RNA (siRNA-1) targeting GDF-8 mRNA was introduced into myoblasts, and an inactive form of siRNA (siRNA-2) was used as a negative control. GDF-8 transcript level was significantly reduced 24 h after the introduction of siRNA-1 to 25% of the control, whereas a 52-kDa GDF-8 precursor was reduced to 45% of the control at 48 h. However, siRNA-2 did not decrease GDF-8 transcript level. When GDF-8-mediated promoter activity was measured chronologically by means of a pGL(CAGA)10-constructed luciferase reporter assay, a concomitant change in activity was initiated after 24 h. The activity rapidly decreased 30 h after siRNA-1 introduction, whereas high activity was maintained at 30–42 h in the control and siRNA-2-treated myoblasts. Myogenic factors such as MyoD and p21, but not myogenin, were altered after 72 h. Cell fusion of the multinucleated myotubes was delayed by the siRNA-1 introduction, and myotubes with aggregated nuclei were shorter and wider. These results strongly suggest that deficiency of GDF-8 delays cell differentiation and causes great alterations in the cellular morphology of chicken embryonic myotubes.
A Central Pattern Generator Producing Alternative Outputs: Temporal Pattern of Premotor Activity
Authors: Norris Brian J. , Weaver Adam L. , Morris Lee G. , Wenning Angela , García Paul A. , Calabrese Ronald L.
Published: April 2006

The central pattern generator for heartbeat in medicinal leeches constitutes seven identified pairs of segmental heart interneurons. Four identified pairs of heart interneurons make a staggered pattern of inhibitory synaptic connections with segmental heart motor neurons. Using extracellular recording from multiple interneurons in the network in 56 isolated nerve cords, we show that this pattern generator produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons. This pattern corresponds to a similarly asymmetric fictive motor pattern in heart motor neurons and asymmetric constriction pattern of the two tubular hearts, synchronous and peristaltic. We provide a quantitative description of the firing pattern of all the premotor interneurons, including phase, duty cycle, and intraburst frequency of this premotor activity pattern. This analysis identifies two stereotypical coordination modes corresponding to synchronous and peristaltic, which show phase constancy over a broad range of periods as do the fictive motor pattern and the heart constriction pattern. Coordination mode is controlled through one segmental pair of heart interneurons (switch interneurons). Side-to-side switches in coordination mode are a regular feature of this pattern generator and occur with changes in activity state of these switch interneurons. Associated with synchronous coordination of premotor interneurons, the ipsilateral switch interneuron is in an active state, during which it produces rhythmic bursts, whereas associated with peristaltic coordination, the ipsilateral switch interneuron is largely silent. We argue that timing and pattern elaboration are separate functions produced by overlapping subnetworks in the heartbeat central pattern generator.
Sciatic Chronic Constriction Injury Produces Cell-Type-Specific Changes in the Electrophysiological Properties of Rat Substantia Gelatinosa Neurons
Authors: Balasubramanyan Sridhar , Stemkowski Patrick L. , Stebbing Martin J. , Smith Peter A.
Published: April 2006

Peripheral nerve injury increases spontaneous action potential discharge in spinal dorsal horn neurons and augments their response to peripheral stimulation. This “central hypersensitivity, ” which relates to the onset and persistence of neuropathic pain, reflects spontaneous activity in primary afferent fibers as well as long-term changes in the intrinsic properties of the dorsal horn (centralization). To isolate and investigate cellular mechanisms underlying “centralization,” sciatic nerves of 20-day-old rats were subjected to 13–25 days of chronic constriction injury (CCI; Mosconi-Kruger polyethylene cuff model). Spinal cord slices were then acutely prepared from sham-operated or CCI animals, and whole cell recording was used to compare the properties of five types of substantia gelatinosa neuron. These were defined as tonic, irregular, phasic, transient, or delay according to their discharge pattern in response to depolarizing current. CCI did not affect resting membrane potential, rheobase, or input resistance in any neuron type but increased the amplitude and frequency of spontaneous and miniature excitatory postsynaptic currents (EPSCs) in delay, transient, and irregular cells. These changes involved alterations in the action potential-independent neurotransmitter release machinery and possible increases in the postsynaptic effectiveness of glutamate. By contrast, in tonic cells, CCI reduced the amplitude and frequency of spontaneous and miniature EPSCs. Such changes may relate to the putative role of tonic cells as inhibitory GABAergic interneurons, whereas increased synaptic drive to delay cells may relate to their putative role as the excitatory output neurons of the substantia gelatinosa. Complementary changes in synaptic excitation of inhibitory and excitatory neurons may thus contribute to pain centralization.
Contribution of M-Waves and H-Reflexes to Contractions Evoked by Tetanic Nerve Stimulation in Humans
Authors: Klakowicz Piotr M. , Baldwin Evan R. L. , Collins David F.
Published: April 2006

Tetanic neuromuscular stimulation evokes contractions by depolarizing motor axons beneath the stimulating electrodes. However, we have shown that extra torque can develop due to the discharge of spinal neurons recruited by the evoked sensory volley. The present experiments investigated whether extra torque in the ankle plantar- and dorsiflexors was associated with enhanced H-reflexes. The tibial and common peroneal nerves were stimulated using 7-s trains (20 Hz for 2 s, 100 Hz for 2 s, 20 Hz for 3 s). Extra torque was defined as significantly more torque during 20-Hz stimulation after the 100-Hz burst (time2) than before it (time1). In 9 of 11 subjects, extra plantarflexion torque developed during stimulation just above motor threshold. In these nine subjects, torque increased from 8 to 13% MVC (time1to time2), the soleus H-reflex increased from 13 to 19% Mmaxand the M-wave of ∼2% Mmaxdid not change significantly. To evoke extra dorsiflexion torque, greater stimulation intensities were required. In 6 of 13 subjects, extra torque developed at intensities that evoked an M-wave of 5–20% Mmaxat time1.In these six subjects, torque doubled from 2 to 4% MVC (time1to time2), whereas tibialis anterior (TA) H-reflexes and M-waves did not change significantly (H-reflex from 0.8 to 2% Mmax; M-wave from 12 to 14% Mmax). In 7 of 13 subjects, extra torque developed at higher stimulation intensities (35–65% Mmax). In these seven subjects, torque increased from 13 to 20% MVC, whereas TA H-reflexes and M-waves were not significantly different (H-reflex from 0.7 to 1% Mmax; M-wave from 49 to 54% Mmax). Thus enhanced H-reflexes contributed to extra plantarflexion, however, other factors generated extra dorsiflexion.
A-type K+ Current of Dopamine and GABA Neurons in the Ventral Tegmental Area
Authors: Koyama Susumu , Appel Sarah B.
Published: April 2006

A-type K+ current ( IA) is a rapidly inactivating voltage-dependent potassium current which can regulate the frequency of action potential (AP) generation. Increased firing frequency of ventral tegmental area (VTA) neurons is associated with the reinforcing effects of some drugs of abuse like nicotine and ethanol. In the present study, we classified dopamine (DA) and GABA VTA neurons, and investigated IA properties and the physiological role of IA in these neurons using conventional whole cell current- and voltage-clamp recording. DA VTA neurons had a mean firing frequency of 3.5 Hz with a long AP duration. GABA VTA neurons had a mean firing frequency of 16.7 Hz with a short AP duration. For IA properties, the voltage-dependence of steady-state IA activation and inactivation was similar in DA and GABA VTA neurons. IA inactivation was significantly faster and became faster at positive voltages in GABA neurons than DA neurons. Recovery from inactivation was significantly faster in DA neurons than GABA neurons. IA current density at full recovery was significantly larger in DA neurons than GABA neurons. In DA and GABA VTA neurons, latency to the first AP after the recovery from membrane hyperpolarization (repolarization latency) was measured. Longer repolarization latency was accompanied by larger IA current density in DA VTA neurons, compared with GABA VTA neurons. We suggest that IA contributes more to the regulation of AP generation in DA VTA neurons than in GABA VTA neurons.
Twitch and Tetanic Properties of Human Thenar Motor Units Paralyzed by Chronic Spinal Cord Injury
Authors: Häger-Ross C. K. , Klein C. S. , Thomas C. K.
Published: April 2006

Little is known about how human motor units respond to chronic paralysis. Our aim was to record surface electromyographic (EMG) signals, twitch forces, and tetanic forces from paralyzed motor units in the thenar muscles of individuals ( n = 12) with chronic (1.5–19 yr) cervical spinal cord injury (SCI). Each motor unit was activated by intraneural stimulation of its motor axon using single pulses and trains of pulses at frequencies between 5 and 100 Hz. Paralyzed motor units ( n = 48) had small EMGs and weak tetanic forces ( n = 32 units) but strong twitch forces, resulting in half-maximal force being achieved at a median of only 8 Hz. The distributions for cumulative twitch and tetanic forces also separated less for paralyzed units than for control units, indicating that increases in stimulation frequency made a smaller relative contribution to the total force output in paralyzed muscles. Paralysis also induced slowing of conduction velocities, twitch contraction times and EMG durations. However, the elevated ratios between the twitch and the tetanic forces, but not contractile speed, correlated significantly with the extent to which unit force summated in response to different frequencies of stimulation. Despite changes in the absolute values of many electrical and mechanical properties of paralyzed motor units, most of the distributions shifted uniformly relative to those of thenar units obtained from control subjects. Thus human thenar muscles paralyzed by SCI retain a population of motor units with heterogeneous contractile properties because chronic paralysis influenced all of the motor units similarly.
Are There Gender Differences in Colorectal Cancer Test Use Prevalence and Correlates?
Authors: McQueen Amy , Vernon Sally W. , Meissner Helen I. , Klabunde Carrie N. , Rakowski William
Published: April 2006

Despite evidence that screening tests reduce colorectal cancer incidence and mortality, screening prevalence is low. Gender differences in test uptake have been reported, but few studies examine correlates of test use by gender. Differences, if present, may inform strategies to increase test use. We examined gender differences in the prevalence and correlates of colorectal cancer test use [fecal occult blood test (FOBT) and endoscopy] using data from the 2002 to 2003 Health Information National Trends Survey. Male (n = 999) and female (n = 1687) respondents ages ≥50 years, without a personal history of colorectal cancer, were interviewed by telephone. Age-adjusted prevalence rates were reported for lifetime, recent, and repeat use by gender and test type. Multivariable logistic regression analyses were used to identify correlates of test use stratified by gender and colorectal cancer test type. More females reported only using FOBT in lifetime and in the past year, whereas more males reported repeat endoscopy use. The use of other tests or combinations of tests did not differ by gender. Consistent positive correlates of colorectal cancer test use for both genders included age, recent physician visits, recent breast or prostate cancer screening, and knowledge of test-specific screening intervals. Correlates that differed by gender included comparative perceived risk, belief that colorectal cancer testing was too expensive, fear of finding colorectal cancer if tested, and attention to and trust in media sources of health information. Such differences, if confirmed in future studies, may inform the use of gender-specific intervention strategies or messages to increase colorectal cancer test use. (Cancer Epidemiol Biomarkers Prev 2006;15(4):782–91)
Hepatitis Viruses, Alcohol, and Tobacco in the Etiology of Hepatocellular Carcinoma in Italy
Authors: Franceschi Silvia , Montella Maurizio , Polesel Jerry , La Vecchia Carlo , Crispo Anna , Dal Maso Luigino , Casarin Pietro , Izzo Francesco , Tommasi Luigi G. , Chemin Isabelle , Trépo Christian , Crovatto Marina , Talamini Renato
Published: April 2006

Mortality rates of hepatocellular carcinoma (HCC) are high in Italy compared with other Western countries. To elucidate further the role of hepatitis B virus (HBV), hepatitis C virus (HCV), alcohol drinking, and tobacco smoking in the etiology of HCC, we carried out a hospital-based case-control study in two areas of Italy: the province of Pordenone in the Northeast and the town of Naples in the South. A total of 229 HCC cases (median age, 66 years) and 431 controls (median age, 65 years) answered a questionnaire and provided blood samples between 1999 and 2002. Odds ratios (OR), percent attributable risks, and corresponding 95% confidence intervals were computed using unconditional multiple logistic regression. ORs for hepatitis B surface antigen (HBsAg) positive versus HBsAg negative and for anti-HCV antibody positive versus anti-HCV antibody negative were 20.2 and 15.6, respectively. Positivity for both markers was associated with an OR of 51.6. Sensitive molecular techniques applied to sera in a subset of HCC cases disclosed a very small number of occult hepatites. Maximal lifetime alcohol intake of ≥35 versus <7 drinks/wk was associated with an HBV/HCV adjusted OR of 5.9. Tobacco smoking was unrelated to HCC risk overall but seemed to enhance HCC risk among virus carriers. Overall, 61% of HCC were attributable to HCV, 13% to HBV, and 18% to heavy alcohol drinking. In conclusion, our study confirms the importance of HCV in HCC etiology in Italy where the widespread dissemination of the virus dates back four or five decades. (Cancer Epidemiol Biomarkers Prev 2006;15(4):683–9)
Plasma C-Reactive Protein and Risk of Colorectal Cancer in a Nested Case-Control Study: Japan Public Health Center–Based Prospective Study
Authors: Otani Tetsuya , Iwasaki Motoki , Sasazuki Shizuka , Inoue Manami , Tsugane Shoichiro ,   Japan Public Health Center–Based Prospective Study Group
Published: April 2006

C-reactive protein is a biomarker indicating inflammation in the body. We measured plasma C-reactive protein to assess whether this biomarker could predict subsequent colorectal cancer incidence. A nested case-control study was conducted within a Japan Public Health Center–based prospective study. During a 11.5-year follow-up, 375 newly diagnosed colorectal cancers were identified in a cohort of 38,373 adults who had returned the baseline questionnaire and provided blood samples. Two controls were selected from the cohort for each case matched by age, sex, study area, date of blood drawn, and fasting time at blood donation. The odds ratio of colorectal cancer for plasma C-reactive protein was estimated using a conditional logistic regression model adjusted for pack-years of smoking, body mass index, alcohol consumption, physical exercise, and family history of colorectal cancer. The highest quartile group of plasma C-reactive protein was significantly associated with colorectal cancer compared with the lowest group (odds ratio, 1.6; 95% confidence interval, 1.1-2.5; Ptrend = 0.053). The association became clearer after excluding cases of rectal cancer (Ptrend = 0.041) and limiting colorectal cancer to the intramucosal type (Ptrend = 0.017). This association was unchanged after deletion of the first 2-year cases. In conclusion, plasma levels of C-reactive protein were associated with a subsequent risk of colon cancer. Inflammation may be involved at the early stage of colon tumor growth. (Cancer Epidemiol Biomarkers Prev 2006;15(4):690–5)
Aberrant Neuropeptide Y and Macrophage Inhibitory Cytokine-1 Expression Are Early Events in Prostate Cancer Development and Are Associated with Poor Prognosis
Authors: Rasiah Krishan K. , Kench James G. , Gardiner-Garden Margaret , Biankin Andrew V. , Golovsky David , Brenner Phillip C. , Kooner Raji , O'Neill Gordon F. , Turner Jennifer J. , Delprado Warick , Lee C. Soon , Brown David A. , Breit Samuel N. , Grygiel John J. , Horvath Lisa G. , Stricker Phillip D. , Sutherland Robert L. , Henshall Susan M.
Published: April 2006

Studies to elucidate dysregulated gene expression patterns in premalignant prostate lesions have identified several candidate genes with the potential to be targeted to prevent the development and progression of prostate cancer and act as biomarkers of early disease. Herein, we explored the importance of two proteins, neuropeptide Y (NPY) and macrophage inhibitory cytokine-1 (MIC-1), as biomarkers of preinvasive prostate disease and investigated the relationship of expression to biochemical recurrence following treatment for localized prostate cancer. NPY and MIC-1 protein expression was determined by immunohistochemistry on tissue microarrays containing 1,626 cores of benign, low-grade prostatic intraepithelial neoplasia (PIN), high-grade PIN (HGPIN), and prostate cancer tissue from 243 radical prostatectomy patients. Both NPY and MIC-1 showed higher proportional immunostaining in HGPIN and prostate cancer compared with benign epithelium (P < 0.0001). NPY and MIC-1 immunostaining was higher in low-grade PIN compared with other benign tissues (both P < 0.0001) and was equivalent to immunostaining in HGPIN. NPY immunostaining of prostate cancer was independently associated with relapse, after adjusting for traditional prognostic factors, as a categorical variable in 20% intervals (P = 0.0449-0.0103) and as a continuous variable (P = 0.0017). Low MIC-1 immunostaining (20% categories) was associated with pathologic stage >2C after adjusting for predictors of pathologic stage (P = 0.3894-0.0176). This is the first study to show that altered NPY and MIC-1 expression are significantly associated with prostate cancer progression and suggests that these molecules be developed further as biomarkers in the management of prostate disease. (Cancer Epidemiol Biomarkers Prev 2006;15(4):711–6)
Haplotype Analysis of Common Vitamin D Receptor Variants and Colon and Rectal Cancers
Authors: Sweeney Carol , Curtin Karen , Murtaugh Maureen A. , Caan Bette J. , Potter John D. , Slattery Martha L.
Published: April 2006

Inherited variants of the vitamin D receptor (VDR) gene may influence cancer risk by altering the effect of vitamin D on cell growth and homeostasis. Studies have examined genotypes for common VDR polymorphisms, including a single nucleotide polymorphism (SNP) detected by Bsm1, a polyadenosine [poly(A)] repeat polymorphism, and a SNP detected by Fok1, as candidates for susceptibility to cancer, but most have not evaluated haplotypes for these markers. We investigated haplotypes for these polymorphisms in case-control studies of colon cancer (1,811 cases and 1,451 controls) and rectal cancer (905 cases and 679 controls). We used the expectation-maximization algorithm to estimate haplotypes for White, Hispanic, African-American, and Asian subjects, tested for differences in VDR haplotype distribution, and calculated odds ratios (OR) for association between haplotype and cancer. The distribution of haplotypes differed by race or ethnic group, but four common haplotypes accounted for the majority of alleles in all groups. VDR haplotype distributions differed between colon cancer cases and controls (P = 0.0004). The common haplotype bLF, containing Bsm1 b (Bsm1 restriction site present), poly(A) long (18-22 repeats), and Fok1 F (restriction site absent) was associated with increased risk of colon cancer, OR 1.15 (95% confidence interval, 1.03-1.28), as was the rare haplotype BLF, containing Bsm1 B (restriction site absent), poly(A) long, and Fok1 F (OR, 2.40; 95% confidence interval, 1.43-4.02). No case-control differences were detected for rectal cancer. In this analysis, haplotypes of the VDR influenced risk of colon cancer, but haplotype variables had only slightly better ability to explain case-control differences than genotype variables. (Cancer Epidemiol Biomarkers prev 2006;15(4):744–9)
C-Peptide, Insulin-like Growth Factor Binding Protein-1, Glycosylated Hemoglobin, and the Risk of Distal Colorectal Adenoma in Women
Authors: Wei Esther K. , Ma Jing , Pollak Michael N. , Rifai Nader , Fuchs Charles S. , Hankinson Susan E. , Giovannucci Edward
Published: April 2006

Background: Determinants of insulin secretion and insulin-like growth factors (IGF) have been directly associated with risk for colorectal cancer. However, few studies have evaluated whether these factors are also associated with risk of colorectal adenoma, the main precursor lesion to colorectal cancer.

Methods: We identified 380 distal colorectal adenoma cases diagnosed between 1989 and 1998 and 380 controls among nondiabetic women from the cohort of 32,826 women, nested in the Nurses' Health Study, who provided blood samples in 1989 to 1990. Cases and controls were individually matched on year of birth, time period of and indication(s) for endoscopy, and date of blood draw.

Results: High concentrations of C-peptide, an indicator of insulin secretion, were statistically significantly associated with risk of distal colorectal adenoma [multivariable relative risk (MVRR) top versus bottom quartile, 1.63; 95% confidence interval (95% CI), 1.01-2.66; P = 0.01], even after including body mass index and physical activity in the statistical model. Fasting IGF binding protein-1 (IGFBP-1) concentrations did not show any clear association with risk for adenoma (MVRR top versus bottom quartile, 1.08; 95% CI, 0.56-2.07). These associations did not differ significantly by size/stage of adenoma. Glycosylated hemoglobin (HbA1c) was associated with a nonstatistically significant increased risk of colorectal adenoma (MVRR top versus bottom quartile, 1.47; 95% CI, 0.89-2.44).

Conclusions: High HbA1c and low IGFBP-1 were not clearly associated with increased risk of distal colorectal adenoma. However, our current results and previous associations between C-peptide and colorectal cancer suggest that hyperinsulinemia may play a role throughout the development of colorectal neoplasia. (Cancer Epidemiol Biomarkers Prev 2006;15(4):750–5)
Polymorphisms in thehMSH2Gene and the Risk of Primary Lung Cancer
Authors: Jung Chi Young , Choi Jin Eun , Park Jung Min , Chae Myung Hwa , Kang Hyo-Gyoung , Kim Kyung Mee , Lee Su Jeong , Lee Won Kee , Kam Sin , Cha Seung Ick , Kim Chang Ho , Han Sung Beom , Jung Tae Hoon , Jeon Su Han , Park Jae Yong
Published: April 2006

Polymorphisms in the DNA repair genes may be associated with differences in the capacity to repair DNA damage, and so this can influence an individual's susceptibility to lung cancer. To test this hypothesis, we investigated the association of hMSH2 −118T>C, IVS1+9G>C, IVS10+12A>G, and IVS12−6T>C genotypes and their haplotypes with the risk of lung cancer in a Korean population. The hMSH2 genotypes were determined in 432 lung cancer patients and in 432 healthy controls who were frequency matched for age and gender. The hMSH2 haplotypes were estimated based on a Bayesian algorithm using the Phase program. The presence of at least one IVS10+12G allele was associated with a significantly decreased risk of adenocarcinoma, as compared with the IVS10+12AA genotype [adjusted odds ratio (OR), 0.59; 95% confidence interval (95% CI), 0.40-0.88; P = 0.01], and the presence of at least one IVS12-6C allele was associated with a significantly increased risk of adenocarcinoma, as compared with the IVS12-6TT genotype (adjusted OR, 1.52; 95% CI, 1.02-2.27; P = 0.04). Consistent with the results of the genotyping analysis, the TGGT haplotype with no risk allele was associated with a significantly decreased risk of adenocarcinoma, as compared with the TCAC haplotype with two risk allele [i.e., IVS10+12A and IVS12-6C allele; adjusted OR, 0.49; 95% CI, 0.30-0.78; P = 0.003 and Pc (Bonferroni corrected P value) = 0.012]. The effect of the hMSH2 haplotypes on the risk of adenocarcinoma was statistically significant in the never smokers and younger individuals (adjusted OR, 0.45; 95% CI, 0.27-0.75; P = 0.002 and Pc = 0.004; and adjusted OR, 0.44; 95% CI, 0.23-0.85; P = 0.014 and Pc = 0.028, respectively) but not in the ever-smokers and older individuals. These results suggest that the hMSH2 polymorphisms and their haplotypes may be an important genetic determinant of adenocarcinoma of the lung, particularly in never smokers. (Cancer Epidemiol Biomarkers Prev 2006;15(4):762–8)
Signaling by the Angiotensin-Converting Enzyme
Authors: Fleming Ingrid
Published: April 2006

Inhibition of the angiotensin-converting enzyme (ACE) protects against the progression of several cardiovascular diseases. Because of its dual role in regulating angiotensin II and bradykinin levels, the positive clinical effects of ACE inhibitors were thought to be the consequence of concomitant reductions in the production of angiotensin II and the degradation of bradykinin. Recent evidence suggests that some of the beneficial effects of ACE inhibitors on cardiovascular function and homeostasis can be attributed to novel mechanisms. These include the accumulation of the ACE substrateN-acetyl-seryl-aspartyl-lysyl-proline, which blocks collagen deposition in the injured heart, as well as the activation of an ACE signaling cascade that involves the activation of the kinase CK2 and the c-Jun N-terminal kinase in endothelial cells and leads to changes in gene expression. Moreover, at least one other ACE homologue (ACE2) is proposed to counteract the detrimental effects associated with the activation of the classical renin-angiotensin system. These data reveal hitherto unexpected levels of internal regulation of the renin-angiotensin system.
Structural stability of CmTin microclusters and nanoparticles: Molecular–dynamics simulations
Authors: Malcıoğlu O.B. , Erkoç Ş.
Published: April 2006

The minimum energy structures of CmTin microclusters and nanoparticles have been investigated theoretically by performing molecular–dynamics (MD) simulations. Selected crystalline and completely random initial geometries are considered. The potential energy function (PEF) used in the calculations includes two– and three–body atomic interactions for C-Ti binary systems. Molecular–dynamics simulations have been performed at 1 K and 300 K. It has been found that initial geometry has a very strong influence on relaxed geometry
Structures and Stabilities of Small Silicon Cluster: High-Level Ab initio Calculations of Si6
Authors: Gao Yi , Killblane Chad , Zeng X.C.
Published: April 2006

The lowest-energy structure of Si6 has been controversial. In this paper, we studied relative stability of this cluster by using the B3LYP, PBE1PBE, MP2, MP4, CCSD, CCSD(T), and QCISD(T) calculations with large basis sets (cc-pVTZ and cc-pVQZ). Our results indicate that the octahedral structure (D4h) is the lowest-energy structure among three isomer candidates studied previously. Our results are also supported by a previous experimental measurement.
Positional Isotope Effect for the Water Tetramer
Authors: Anick D. J.
Published: April 2006

Ab initio studies are carried out for the water tetramer with a single H replaced by D, (H2O)3(HDO). The isomer with D in a free position, H7DfO4, has ZPE 0.17 kcal/mol higher than the isomer with D in an H-bond, H7DbO4. The same ZPE difference is found for HbD7O4 vs HfD7O4. The difference may be large enough for a preference for H rather than D in a free position to be experimentally measurable. Exploration of the components of ZPE shows that the stretch component alone favors H7DfO4, but this is more than compensated by the bend and torsion components.
A Density Functional Study of Structures and Vibrations of Ta3O and Ta3O−
Authors: Calaminici Patrizia , Flores–Moreno Roberto , Köster Andreas M.
Published: April 2006

Density functional calculations of neutral and anionic tantalum trimer monoxide are presented. The calculations were performed employing scalar quasi–relativistic effective core potentials. Different isomers of Ta3O and Ta3O- were studied in order to determinethe ground state structures. For both systems a planar C2vstructure with an edge-boundoxygen atom was found as ground state. Equilibrium structure parameters, harmonic frequencies, adiabatic electron affinity and Kohn-Sham orbital diagrams are reported. The calculated values are in good agreement with the available experimental data obtained from negative ion photoelectron spectroscopy. The correlation diagram between the neutral and anionic Ta3O shows that, in agreement with the experimental prediction, the extra electron in the anionic system occupies a nonbonding orbital.
A theoretical study on size-dependent properties of rock-salt ZnS clusters
Authors: Pal Sougata , Goswami Biplab , Sarkar Pranab
Published: April 2006

We present the results of our theoretical calculation on structural, electronic and optical properties of rock-salt ZnnSn clusters as a function of size of the clusters. We have focused on the variation of Mulliken populations, electronic energy levels, band gap and stability as a function of size for rock-salt derived ZnS clusters. We have also compared the structural and electronic properties of rock-salt derived clusters with those of zinc-blende and wurtzite clusters, previously studied
Enhancement of fullerene stabilities from excited electronic states
Authors: Slanina Zdeněk , Uhlík Filip , Lee Shyi-Long , Adamowicz Ludwik , Nagase Shigeru
Published: April 2006

There is one factor in relative stabilities of isomeric fullerenes that has rarely been studied so far – contribution of excited electronic states. The contribution is clearly defined by the electronic partition function, supposing the related excitation energies can be evaluated. As temperatures in fullerene synthesis are high, the term should be taken into account. In this report the problem is studied on four isomeric systems. The first system is the set of five IPR (isolated pentagon rule) isomers of C78, relatively well known from experiment. The second system studied is a model set of four isomers of Mg@C72 (not yet isolated species). The third case consists of seven IPR isomers of C80. The last set is formed by six C74 cages. The electronic excitation energies are computed by limited configuration interaction (CI) approach, mostly with the ZINDO semiempirical method. Isomers of Mg@C72 are evaluated by means of the single-excitation CI or CI-Singles (CIS) in the standard LanL2DZ basis set. It is found that the electronic partition function can cause significant changes in the computed equilibrium relative concentrations of isomers at high temperatures. Metallofullerenes are more likely candidates for such enhanced effects.
Recent progress in the computational study of transition metal doped Si clusters
Authors: Han Ju-Guang , Hagelberg Frank
Published: April 2006

Computational investigations on silicon clusters (Sin) in combination with atomic transition metal (TM) impurities are reviewed in this contribution. Emphasis is placed on studies that focus on the size exohedral to endohedral evolution features of TMSin, such as the critical ligand number for the transition from equilibrium geometry. Geometric, energetic, electronic and magnetic characteristic of TMSin are discussed in the size region n ≤ 20. It is pointed out that selected TMSin systems with n = 12 and n = 16 emerge from present computational research as the most promising candidates for building blocks of novel nanomaterials.
Fusion and fission of atomic clusters: recent advances
Authors: Obolensky O. I. , Solov’yov I. A. , Solov’yov A. V. , Greiner W.
Published: April 2006

We review recent advances made by our group in finding optimized geometries of atomic clusters as well as in description of fission of charged small metal clusters. We base our approach to these problems on analysis of multidimensional potential energy surface. For the fusion process we have developed an effective scheme of adding new atoms to stable cluster isomers which provides good starting points for a global optimization procedure and thus allows one to obtain optimal geometries of larger clusters in an efficient way. We apply this algorithm to finding geometries of metal and noble gas clusters. For the fission process the analysis of the potential energy landscape calculated on the ab initio level of theory allowed us to obtain very detailed information on energetics and pathways of the different fission channels for the Na2+ 10 clusters.
On the performance of DFT methods on electric polarizability and hyperpolarizability calculations for the lithium tetramer
Authors: Maroulis George , Xenides Demetrios
Published: April 2006

We present a rigorous analysis of the performance of a set of twelve DFT methods on the calculation of the static electric polarizability and hyperpolarizability of the lithium tetramer. Our analysis reveals essential similarities and dissimilarities in the performance of these methods.
Tight-binding Calcium Clusters from Adaptive Tempering Monte Carlo Simulation
Authors: Dong Xiao , Gatica Silvina M. , Blaisten-Barojas Estela
Published: April 2006

The most stable structure of calcium clusters with 14 to 32 atoms is optimized by the Adaptive Tempering Monte Carlo method. The binding energy of the clusters is obtained within the tight-binding approach parameterized in a previous work. The optimization process is started at about 800 K and the tempering brings the structure to the global minimum ending the process at 1 K. It is found that six cluster sizes, 15, 16, 18, 21, 23 and 25 have a global minimum structure not reported in the literature. In this size range, Ca15, Ca21 and Ca23 are the preferred geometries that can be identified as magic numbers. The tight-binding one-electron levels in the valence band display a large energy gap of 0.5 eV between the last occupied and first unoccupied levels for the magic number clusters. This band gap is 5 to 10 times smaller for other cluster sizes.
Strategic Hotel Development and Positioning
Authors: O’neill John W. , Mattila Anna S.
Published: April 2006

A study of more than nineteen hundred U.S. hotels for the years 2002 and 2003 found that a hotel’s net operating income percentage is most closely tied to its occupancy, although average daily rate (ADR) has a strong influence, as does market segment (also known as chain scale), the age of the property, and brand affiliation. A hotel’s size (that is, number of rooms) and location (e.g., urban or highway) also influence net operating income (NOI), but a hotel’s region does not significantly affect NOI percentage. The year 2002 data particularly show the importance of heads in beds. Hoteliers cut ADR heavily in that recession year, and those hotels that maintained strong occupancy were the ones that enjoyed strong NOI. While resorts and urban hotels generated the highest NOI in raw dollar volume, economy hotels had the highest NOI percentage and midscale hotels with food and beverage service (F&B) had the lowest NOI percentage.
How Hospitality Students Develop Perceptions of Potential Employers
Authors: Cho Seonghee , Woods Robert H. , Sciarini Mike
Published: April 2006

This 2003 study repeats and extends a 1997 investigation of how students perceive hospitality organizations as prospective employers. Using structural equation modeling, the study confirmed five factors to examine the relationship between the factors and the likelihood of employment in eight industry segments. The greatest difference between the 1997 findings and those of 2003 is the rise of the Internet in guiding students’ attitudes toward various industry segments. With regard to quick-service restaurants (QSRs) and private clubs, company-sponsored events particularly improve the likelihood of that a student will accept employment in those segments. Word of mouth and experience as a customer, on the other hand, can decrease a student’s interest in working in economy hotels and QSRs (even though direct work experience improves notice for those two segments). Ironically, the personal recruiting visit seems to have less influence on employment decisions than one might expect.
Ethnic discrimination and global self-worth in early adolescents: The mediating role of ethnic self-esteem
Authors: Verkuyten Maykel , Thijs Jochem
Published: April 2006

Peer victimization based on one's ethnic group membership contributes to the problems and conflicts of ethnic minority children around the world. With ethnic discrimination, a part of the self is implicated. Hence, it is likely that being treated negatively on the basis of one's ethnicity has a negative influence on ethnic self-esteem and thereby on feelings of global self-worth. Following structural models of the self it was predicted that ethnic self-esteem mediates the relationship between ethnic peer discrimination and global self-worth. To test this prediction a large scale study ( N= 2682) was conducted among Turkish, Moroccan, Surinamese and Dutch young adolescents (aged 10 to 13) living in The Netherlands. Using structural equation analysis, we found the predicted mediation for all four groups of participants. In addition, to examine the precise role of ethnic discrimination we also considered other types and dimensions of peer victimization. Our distinction between reasons (personal and ethnic) and types (teasing/name calling and social exclusion form play) of peer victimization fitted the data adequately. Global self-worth was more strongly related to experiences with teasing and name calling than to social exclusion.