Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions

We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

Does rofecoxib increase TNF-alpha levels?

OBJECTIVE

Rofecoxib (Vioxx), the first COX-2 selective non-steroidal anti-inflammatory drug (NSAID), was recently withdrawn from the market due to the increased risk of acute myocardial infarction. The precise mechanism responsible for this phenomenon still remains unknown. Tumor necrosis factor alpha (TNF-alpha) is a cytokine, possibly most responsible for mortality in patients with acute myocardial infarction. However, this study was designed to study possible effects of rofecoxib on the level of TNF-alpha by using MSU crystal induced inflammation in the rat subcutaneous air pouch model.

METHODS

Rat subcutaneous air pouches were produced and examinations commenced 6 days later. Control groups received only MSU crystals, or no crystals or drugs. To begin with, rofecoxib (30 mg/kg), indomethacin (20 mg/kg) or diclofenac (3 mg/kg) were administered to groups of 5 rats each. Thirty minutes later, MSU crystals were injected into air pouches, except for the negative control group. Twenty-four hours later, the rats were sacrificed for aspiration of fluid and for the dissection of pouch walls to determine leukocyte counts, pouch wall histology, and to assay IL-10 and TNF-alpha.

RESULTS

Intra-pouch injection of MSU crystals, compared to non-injected pouches, caused an increase in white blood cell count (WBC) (30 +/- 44.7 versus 4508 +/- 792.3 cells/mm3), in the numbers of pouch wall vessels (vascular index) (4.8 +/- 0.3 versus 11.4 +/- 1.5 vessels/high-power field) and in TNF-alpha (50.0 +/- 13.4 versus 70.34 +/- 20.9 ng/mL), but not in interleukin-10 (IL-10) (60.6 +/- 63.0versus 61.48 +/- 7.1). WBC and vascular index were significantly reduced in all study groups compared to the control group (p < 0.05). Levels of TNF- in fluids were unexpectedly and significantly (p < 0.05) increased in all cases. The highest level of TNF-alpha was found in the rofecoxib group. In contrast to TNF-alpha, IL-10 levels were significantly (p < 0.05) decreased in all three drug groups. Indomethacin tended to suppress inflammation more effectively. However, there was no significant difference between the groups for IL-10 (p > 0.05).

CONCLUSION

All three NSAIDs exhibited anti-inflammatory activity against MSU crystal induced inflammation. The difference in anti-inflammatory effects of these three non-steroidal drugs is seen not only in the anti-inflammatory effect on MSU induced inflammation but also in the nature of the effects. Refocoxib tended to increase the TNF-alpha level. Whether increased TNF-alpha levels can help explain the side effect of COX-2 specific inhibitors still requires further studies.

Snoezelen multi-sensory environments: task engagement and generalization

These experiments explored whether behavioral improvements observed during Snoezelen OT treatment sessions carried over to two different settings for three people with moderate/severe intellectual disability, autism and severe challenging behaviors. Experiment 1 explored engagement during a functional task immediately following the treatment sessions while experiment 2 explored changes in the frequencies of challenging behaviors on the days after treatment sessions. Investigators found carryover for two of the three participants to both post-session engagement as well as to the daily frequency of challenging behaviors on days following the OT sessions.

Evaluation of patterns of failure and subjective salivary function in patients treated with intensity modulated radiotherapy for head and neck squamous cell carcinomas

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Background: Conventional RT (CRT) for head and neck squamous cell carcinoma (HNSCC) is associated with severe late side effects which can worsen quality of life of surviving patients. Intensity-modulated radiotherapy (IMRT) allows the delivery of tumoricidal doses to the target volume while maintaining tolerable doses to critical organs. Several previous studies have demonstrated promising results for tumor control and disease free survival for HNSCC treated with IMRT. In this study, we correlated patterns of failure with target volume delineations in HNSCC treated with IMRT at our instittuion and evaluated subjective xerostomia outcomes after IMRT as compared to CRT. Material and Methods: Between 1/00 and 4/05, 69 patients with newly diagnosed non-metastatic HNSCC underwent curative parotid sparing IMRT at Stanford University. Sites included were oropharynx (39), oral cavity (8), larynx (8), hypopharynx (8) and unknown primary (6). Forty-six patients received definitive IMRT (66 Gy, 2.2 Gy/fraction), and 23 patients received post-operative IMRT (60.2 Gy, 2.15 Gy/fraction). Fifty-one patients also received concomitant chemotherapy. Post-treatment salivary gland function was evaluated by a validated xerostomia questionnaire (XQ) in 29 IMRT and 75 matched non-IMRT patients > 6 months after completing RT. Results: At a median follow-up of 17 months for living patients (range 6.5–60), 7 locoregional failures were observed, 5 in the gross target volume (GTV), 1 in the clinical target volume (CTV), and 1 at the junction of the IMRT and supraclavicular fields. The 2-year Kaplan Meier estimates of locoregional control and overall survival were 92% and 80% for definitive IMRT and 85% and 85% for post-op IMRT patients, respectively. The mean total XQ score was significantly better for IMRT than for non-IMRT patients (p = 0.006). Conclusions: The predominant pattern of failure in IMRT treated patients is in the GTV. Parotid sparing with IMRT resulted in decreased subjective xerostomia and may improve quality of life in irradiated HNSCC patients.

No significant financial relationships to disclose.

Increased use of selective serotonin reuptake inhibitors in patients admitted with gastrointestinal haemorrhage: a multicentre retrospective analysis

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) can adversely affect platelet function and impair haemostasis. Various bleeding complications have been reported in persons taking SSRIs including an increased risk of gastrointestinal haemorrhage (GIH).

AIM

To evaluate SSRI use in patients hospitalized with GIH compared with controls.

METHODS

A retrospective, multicentre case-control study determined use of SSRIs, non-steroidal anti-inflammatory drugs (NSAIDs), aspirin, clopidogrel, coumadin and enoxaparin in patients admitted with GIH and age- and sex-matched controls. Exclusion criteria included liver disease, portal hypertension or bleeding diathesis.

RESULTS

A total of 579 cases were matched with 1000 controls. SSRI use was 19.2% in cases and 13.6% in controls [OR (95% CI) = 1.5 (1.2-2.0); P = 0.003]. NSAIDs were used by 7.3% of cases and 3.8% of controls [OR = 2.0 (1.3-3.1); P = 0.003]. SSRI use was more strongly associated with lower [1.8 (1.2-2.8)] rather than upper [1.3 (0.83-1.9)] GIH. Significant interactions existed for SSRI use with NSAIDs and aspirin.

CONCLUSIONS

Patients admitted with GIH gastrointestinal bleeding were more likely to be taking SSRIs than controls. This association exists for lower as well as upper GIH. Physicians should be aware of this risk particularly in patients already using medications that increase GIH risk.

The effect of the levonorgestrel intrauterine system on uterine artery blood flow 1 year after insertion

OBJECTIVE

To assess whether the morphological alterations of the endometrium induced by the levonorgestrel intrauterine system affect the uterine artery vasculature.

METHODS

Forty-eight premenopausal women attending our gynecology clinic because of menorrhagia were enrolled into the study. Clinical measures of menstrual bleeding, endometrial thickness and Doppler flow of the uterine artery (resistance (RI) and pulsatility (PI) indices) were evaluated before and 1 year after insertion of the levonorgestrel intrauterine system. Thirty-three (69%) women were available for re-evaluation at the end of the first year and the continuation rate was 76% (n = 25). A paired samples t-test and the Mann-Whitney U-test were used for comparison of values between groups.

RESULTS

The mean age of the thirty-three patients was 44.3 +/- 7.6 years. Nine patients (27.3%) were amenorrheic and three patients were in menopause at the end of the year. After excluding the women in menopause, the increase in mean RI 1 year after insertion was statistically significant (0.86 +/- 0.07 vs. 0.81 +/- 0.08; P = 0.046), as was the decrease in uterine volume (736.9 +/- 276.9 mL vs. 972.75 +/- 465.71 mL; P = 0.029). The mean endometrial thickness decreased 1 year after insertion, but not significantly (4.6 +/- 1.6 mm vs. 6.6 +/- 3.5 mm; P = 0.07) and there was no statistically significant difference in mean PI between the groups (2.00 +/- 0.63 and 2.03 +/- 0.64 pre- and post-insertion, respectively; P = 0.83).

CONCLUSION

The increase in mean RI of the uterine artery and the decrease in uterine volume 1 year after insertion of the levonorgestrel intrauterine system may be related to its progestational effect. This increase in RI may have a role in cessation of menstruation.

Post-phototherapy neonatal bilirubin rebound: a potential cause of significant hyperbilirubinaemia

AIM

To determine the incidence of post-phototherapy neonatal plasma total bilirubin (PTB) rebound.

METHODS

A prospective clinical survey was performed on 226 term and near-term neonates treated with phototherapy in the well baby nursery of the Shaare Zedek Medical Center from January 2001 to September 2002. Neonates were tested for PTB 24 hours (between 12 and 36 hours) after discontinuation of phototherapy, with additional testing as clinically indicated. The main outcome measure, significant bilirubin rebound, was defined as a post-phototherapy PTB > or =256 micromol/l. Phototherapy was not reinstituted in all cases of rebound, but rather according to clinical indications.

RESULTS

A total of 30 (13.3%) neonates developed significant rebound (mean (SD) PTB 287 (27) micromol/l, upper range 351 micromol/l). Twenty two of these (73%) were retreated with phototherapy at mean PTB 296 (29) micromol/l. Multiple logistic regression analysis showed significant risk for aetiological risk factors including positive direct Coombs test (odds ratio 2.44, 95% CI 1.25 to 4.74) and gestational age <37 weeks (odds ratio 3.21, 95% CI 1.29 to 7.96). A greater number of neonates rebounded among those in whom phototherapy was commenced < or =72 hours (26/152, 17%) compared with >72 hours (4/74, 5.4%) (odds ratio 3.61, 95% CI 1.21 to 10.77).

CONCLUSION

Post-phototherapy neonatal bilirubin rebound to clinically significant levels may occur, especially in cases of prematurity, direct Coombs test positivity, and those treated < or =72 hours. These risk factors should be taken into account when planning post-phototherapy follow up.

Distributions of charged hadrons associated with high transverse momentum particles in pp and Au+Au collisions at sqrt[sNN]=200 GeV

Charged hadrons in [EQUATION: SEE TEXT] associated with particles of [EQUATION: SEE TEXT] are reconstructed in pp and Au+Au collisions at sqrt[sNN]=200 GeV. The associated multiplicity and p magnitude sum are found to increase from pp to central Au+Au collisions. The associated p distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed.

Multistrange Baryon elliptic flow in Au+Au collisions at square root of sNN=200 GeV

We report on the first measurement of elliptic flow v2(pT) of multistrange baryons Xi- +Xi+ and Omega- + Omega+ in heavy-ion collisions. In minimum-bias Au+Au collisions at square root of s(NN)=200 GeV, a significant amount of elliptic flow, comparable to other nonstrange baryons, is observed for multistrange baryons which are expected to be particularly sensitive to the dynamics of the partonic stage of heavy-ion collisions. The pT dependence of v2 of the multistrange baryons confirms the number of constituent quark scaling previously observed for lighter hadrons. These results support the idea that a substantial fraction of the observed collective motion is developed at the early partonic stage in ultrarelativistic nuclear collisions at the Relativistic Heavy Ion Collider.

Multiplicity and pseudorapidity distributions of photons in Au+Au collisions at square root of (S(NN)) = 62.4 GeV

We present the first measurement of pseudorapidity distribution of photons in the region 2.3 < or = eta < or = 3.7 for different centralities in Au+Au collisions at square root of (S(NN)) = 62.4 GeV. We find that the photon yield scales with the number of participating nucleons at all collision centralities studied. The pseudorapidity distribution of photons, dominated by pi0 decays, has been compared to those of charged pions, photons, and inclusive charged particles from heavy-ion and nucleon-nucleon collisions at various energies. The photon production has been shown to be consistent with the energy and centrality independent limiting fragmentation scenario.

Neonatal bilirubin production-conjugation imbalance: effect of glucose-6-phosphate dehydrogenase deficiency and borderline prematurity

OBJECTIVE

To evaluate relations between production and conjugation of bilirubin in the pathophysiology of jaundice in glucose-6-phosophate dehydrogenase (G6PD) deficient neonates.

METHODS

Term and borderline premature (35-37 weeks gestational age), healthy, male, G6PD deficient neonates were studied close to the beginning of the 3rd day. Blood carboxyhaemogobin corrected for inspired CO (COHbc; an index of bilirubin production) and serum total conjugated bilirubin (TCB; a reflection of bilirubin conjugation) were measured in simultaneously drawn blood samples by gas chromatography and reverse phase high performance liquid chromatography respectively. A bilirubin production-conjugation index comprising COHbc/TCB was determined; a high index reflects imbalance between the bilirubin production and conjugation processes. COHbc and TCB individually and the production-conjugation index were studied in relation to serum total bilirubin (STB) concentration.

RESULTS

Fifty one G6PD deficient neonates were sampled at 51 (8) hours. COHbc values did not correlate with STB (r=0.22, p=0.15). TCB did correlate inversely with STB (r=-0.42, p=0.004), and there was a positive correlation between the production-conjugation index and STB (r=0.45, p=0.002). The production-conjugation index (median (interquartile range)) was higher in the premature (n=8) than term neonates (2.31 (2.12-3.08) v 1.05 (0.53-1.81), p=0.003). This difference was the result of changes in TCB.

CONCLUSIONS

The data show that jaundice in G6PD deficient neonates is the result of an imbalance between production and conjugation of bilirubin with a tendency for inefficient bilirubin conjugation over increased haemolysis in its pathogenesis. Borderline premature infants are at special risk of bilirubin production-conjugation imbalance.

Open charm yields in d+Au collisions at squareroot[sNN]=200 GeV

Midrapidity open charm spectra from direct reconstruction of D0(D0)-->K-/+pi+/- in d+Au collisions and indirect electron-positron measurements via charm semileptonic decays in p+p and d+Au collisions at squareroot[sNN]=200 GeV are reported. The D0(D0) spectrum covers a transverse momentum (pT) range of 0.1<pT<3 GeV/c, whereas the electron spectra cover a range of 1<pT<4 GeV/c. The electron spectra show approximate binary collision scaling between p+p and d+Au collisions. From these two independent analyses, the differential cross section per nucleon-nucleon binary interaction at midrapidity for open charm production from d+Au collisions at BNL RHIC is dsigma(NN)cc/dy=0.30+/-0.04(stat)+/-0.09(syst) mb. The results are compared to theoretical calculations. Implications for charmonium results in A+A collisions are discussed.

Dietary antioxidants and paraoxonases against LDL oxidation and atherosclerosis development

Oxidative modification of low-density lipoprotein (LDL) in the arterial wall plays a key role in the pathogenesis of atherosclerosis. Under oxidative stress LDL is exposed to oxidative modifications by arterial wall cells including macrophages. Oxidative stress also induces cellular-lipid peroxidation, resulting in the formation of 'oxidized macrophages', which demonstrate increased capacity to oxidize LDL and increased uptake of oxidized LDL. Macrophage-mediated oxidation of LDL depends on the balance between pro-oxidants and antioxidants in the lipoprotein and in the cells. LDL is protected from oxidation by antioxidants, as well as by a second line of defense--paraoxonase 1 (PON1), which is a high-density lipoprotein-associated esterase that can hydrolyze and reduce lipid peroxides in lipoproteins and in arterial cells. Cellular paraoxonases (PON2 and PON3) may also play an important protective role against oxidative stress at the cellular level. Many epidemiological studies have indicated a protective role for a diet rich in fruits and vegetables against the development and progression of cardiovascular disease. A large number of studies provide data suggesting that consumption of dietary antioxidants is associated with reduced risk for cardiovascular diseases. Basic research provides plausible mechanisms by which dietary antioxidants might reduce the development of atherosclerosis. These mechanisms include inhibition of LDL oxidation, inhibition of cellular lipid peroxidation and consequently attenuation of cell-mediated oxidation of LDL. An additional possible mechanism is preservation/increment of paraoxonases activity by dietary antioxidants. This review chapter presents recent data on the anti-atherosclerotic effects and mechanism of action of three major groups of dietary antioxidants-vitamin E, carotenoids and polyphenolic flavonoids.

Azimuthal anisotropy and correlations at large transverse momenta in p + p and Au + Au collisions at square root sNN=200 GeV

Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au + Au collisions at square root s(NN)=200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au + Au collisions to those in p + p at the same energy. The elliptic anisotropy v(2) is found to reach its maximum at p(t) approximately 3 GeV/c, then decrease slowly and remain significant up to p(t) approximately 7-10 GeV/c. Stronger suppression is found in the back-to-back high-p(t) particle correlations for particles emitted out of plane compared to those emitted in plane. The centrality dependence of v(2) at intermediate p(t) is compared to simple models based on jet quenching.

Glucose-6-phosphate dehydrogenase activity in male premature and term neonates

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD) activity is higher in term neonates than in adults. Some studies have suggested that activity may be even higher in preterm infants.

OBJECTIVES

To determine if G6PD activity is higher in preterm than term neonates, and whether higher activity would interfere with diagnosis of G6PD deficiency in premature infants.

METHODS

G6PD activity was determined in the first 48 hours after delivery in male premature, term, and near term infants. G6PD deficient neonates were separated, and the remaining premature infants compared with healthy, male, G6PD normal, near term and term neonates.

RESULTS

Ninety four premature infants (mean (SD) gestational age 31.9 (3.8) weeks (range 23-36)) were studied. In four, G6PD activity was 0.8-1.8 U/g haemoglobin (Hb), which is clearly in the deficient range with no overlap into the normal range. G6PD activity in the remaining premature infants was significantly higher than in 24 near term and term neonates (gestational age > or = 37 weeks) (14.2 (4.6) v 12.0 (3.8) U/g Hb). Further analysis showed that significance was limited to those born between 29 and 32 weeks gestation, in which group G6PD activity was significantly higher than in those born before 29 weeks gestation, at 33-36 weeks gestation, and > or = 37 weeks gestation.

CONCLUSIONS

G6PD activity is higher in premature infants born between 29 and 32 weeks gestation than in term neonates. This did not interfere with diagnosis of G6PD deficiency.

Multistrange baryon production in Au-Au collisions at sqrt[s(NN)]=130 GeV

The transverse mass spectra and midrapidity yields for Xis and Omegas are presented. For the 10% most central collisions, the (-)Xi(+)/h(-) ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi(-)/h(-) stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi, K, p, and Lambdas.

Cross sections and transverse single-spin asymmetries in forward neutral-pion production from proton collisions at sqrt[s]=200 GeV

Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at sqrt[s]< or =20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider.

Identified particle distributions in pp and Au+Au collisions at square root of (sNN)=200 GeV

Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.

Rho0 production and possible modification in Au+Au and p+p collisions at square root [sNN] = 200 GeV

We report results on rho(770)(0)-->pi(+)pi(-) production at midrapidity in p+p and peripheral Au+Au collisions at sqrt[s(NN)]=200 GeV. This is the first direct measurement of rho(770)(0)-->pi(+)pi(-) in heavy-ion collisions. The measured rho(0) peak in the invariant mass distribution is shifted by approximately 40 MeV/c(2) in minimum bias p+p interactions and approximately 70 MeV/c(2) in peripheral Au+Au collisions. The rho(0) mass shift is dependent on transverse momentum and multiplicity. The modification of the rho(0) meson mass, width, and shape due to phase space and dynamical effects are discussed.