Measurement of polarization observables T, P, and H in π0 and η photoproduction off quasi-free nucleons.

The target asymmetry T, recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive π0 and η photoproduction off quasi-free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γp→π0p and γp→ηp reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the ηn system at W=1.68GeV. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S11(1535) and S11(1650) resonances within the S11-partial wave.

Measurement of the Charge-Averaged Elastic Lepton-Proton Scattering Cross Section by the OLYMPUS Experiment.

We report the first measurement of the average of the electron-proton and positron-proton elastic scattering cross sections. This lepton charge-averaged cross section is insensitive to the leading effects of hard two-photon exchange, giving more robust access to the proton's electromagnetic form factors. The cross section was extracted from data taken by the OLYMPUS experiment at DESY, in which alternating stored electron and positron beams were scattered from a windowless gaseous hydrogen target. Elastic scattering events were identified from the coincident detection of the scattered lepton and recoil proton in a large-acceptance toroidal spectrometer. The luminosity was determined from the rates of Møller, Bhabha, and elastic scattering in forward electromagnetic calorimeters. The data provide some selectivity between existing form factor global fits and will provide valuable constraints to future fits.

Measurement of the helicity asymmetry E for the reaction γ p → π 0 p : The CBELSA/TAPS Collaboration.

A measurement of the double-polarization observable E for the reaction γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C 4 H 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from E γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

Observation of the pη

Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.

Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering Determined by the OLYMPUS Experiment.

The OLYMPUS Collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, R_{2γ}, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01 GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of ≈20° to 80°. The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved gas electron multiplier and multiwire proportional chamber detectors at 12°, as well as symmetric Møller or Bhabha calorimeters at 1.29°. A total integrated luminosity of 4.5 fb^{-1} was collected. In the extraction of R_{2γ}, radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of R_{2γ}, presented here for a wide range of virtual photon polarization 0.456<ε<0.978, are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data.

N(1520) 3/2(-) helicity amplitudes from an energy-independent multipole analysis based on new polarization data on photoproduction of neutral pions.

New data on the polarization observables T, P, and H for the reaction γp→pπ(0) are reported. The results are extracted from azimuthal asymmetries when a transversely polarized butanol target and a linearly polarized photon beam are used. The data were taken at the Bonn electron stretcher accelerator ELSA using the CBELSA/TAPS detector. These and earlier data are used to perform a truncated energy-independent partial wave analysis in sliced-energy bins. This energy-independent analysis is compared to the results from energy-dependent partial wave analyses.

Preventive effects of perioperative parecoxib on post-discectomy pain.

BACKGROUND: Cyclooxygenase inhibitor treatment is viewed increasingly critical because of safety considerations, and there are several open questions on their optimal use. METHODS: In a randomized placebo-controlled study in 320 patients undergoing discectomy, we administered parecoxib 40 mg either perioperatively (before operation and after operation), after operation (first dose given in the evening after surgery), or before operation (single parecoxib dose given 45 min before surgery). We measured the main outcome variables: average pain score, morphine consumption, and opioid-related symptom distress at 25, 49, and 73 h after surgery. RESULTS: Perioperative parecoxib significantly (i) improved the pain score compared with both placebo and postoperative parecoxib, (ii) decreased morphine consumption, and (iii) reduced the opioid-related symptom distress score. Neither a single preoperative dose nor postoperative parecoxib (first dose given in the evening after surgery) significantly improved morphine's analgesic effectiveness. CONCLUSIONS: Perioperative parecoxib compared with postoperative parecoxib improves post-discectomy pain and results in a reduction in adverse effects associated with opioid therapy. Postoperative parecoxib, or a single pre-incisional parecoxib dose, does not significantly improve post-discectomy pain or opioid side-effects up to 3 days after surgery.

Cinacalcet hydrochloride reduces the serum calcium concentration in inoperable parathyroid carcinoma.

BACKGROUND: Management of inoperable parathyroid carcinoma presents a challenge because until recently, effective medical therapy was not available. Morbidity and mortality result primarily from severe hypercalcemia. We assessed the ability of the calcimimetic cinacalcet HCl to reduce serum calcium in patients with parathyroid carcinoma as well as its effect on PTH concentrations, bone turnover markers, safety, and health-related quality of life variables. METHODS: Twenty-nine patients with parathyroid carcinoma were enrolled in this open-label, single-arm study consisting of titration and maintenance phases. Cinacalcet doses were titrated (30 mg twice daily to 90 mg four times daily) for 16 wk or until serum calcium was no more than 10.0 mg/dl. The study endpoint was the proportion of patients with at least a 1 mg/dl reduction in serum calcium at the end of the titration phase (responders). RESULTS: Mean (+/- se) serum calcium (14.1 +/- 0.4 mg/dl) and PTH (697 +/- 94 pg/ml) were markedly elevated at baseline. At the end of the titration period, serum calcium was reduced by at least 1 mg/dl in 62% of patients (mean decline to 12.4 +/- 0.5 mg/dl). In the 18 responders, serum calcium fell from 15.0 +/- 0.5 to 11.2 +/- 0.3 mg/dl (P < 0.001). The greatest reductions in serum calcium were observed in patients with highest baseline calcium levels. PTH levels decreased, but not significantly, to 635 +/- 73 pg/ml (-4.6%). Adverse events included nausea, vomiting, headache, and fracture. CONCLUSIONS: Cinacalcet effectively reduces hypercalcemia in approximately two thirds of patients with inoperable parathyroid carcinoma and may represent an important new treatment option for these patients.

Cinacalcet HCI (Sensipar/Mimpara) is an effective chronic therapy for hemodialysis patients with secondary hyperparathyroidism.

AIMS: This 1-year double-blind, placebo-controlled, multicenter study evaluated the long-term safety and efficacy of cinacalcet for the treatment of secondary hyperparathyroidism in patients receiving hemodialysis. METHOD: Patients were randomly assigned in a 1:1 ratio to cinacalcet or control treatment groups. The initial dose of cinacalcet (or matching placebo) was 30 mg. Doses were titrated every 3 or 4 weeks based on the intact parathyroid hormone (iPTH) response and safety profile. Sequential doses included 30, 60, 90, 120 and 180 mg/d. Phosphate binders and vitamin D sterols were adjusted per protocol as needed to control levels of calcium and phosphorus. Efficacy and safety were compared between treatment groups among patients who completed the study (52 total weeks of treatment). Reasons for withdrawal are presented for patients who did not complete the study. RESULTS: A total of 210 patients completed 52 weeks of double-blinded treatment with cinacalcet (n = 99) or placebo (n = 111). Over the last 6 months of the study, a greater proportion of patients in the cinacalcet group than the control group achieved an iPTH level < or = 250 pg/ml (61.6 vs. 9.9%, p < 0.001) or a > or = 30% decrease in iPTH from baseline (81.8 vs. 21.6%, p < 0.001). Mean iPTH levels decreased by -47.8% in the cinacalcet group and increased by +12.9% in the control group. Mean percentage changes in other laboratory values in the cinacalcet and control groups included the following: serum calcium -6.5 vs. +0.9% (p < 0.001), serum phosphorus -3.6 vs. -1.1% (p = 0.465), and Ca x P -9.9 vs. -0.3% (p = 0.006). The most commonly reported adverse events related to study drug by the investigators included nausea (13% cinacalcet, 5% control), investigator-reported hypocalcemia (11% cinacalcet, 1% control), vomiting (9% cinacalcet, 2% control), dyspepsia (5% cinacalcet, 4% control), and diarrhea (5% cinacalcet, 2% control). CONCLUSIONS: Treatment with cinacalcet is a safe and effective therapy for long-term control of secondary hyperparathyroidism. 1-year therapy with cinacalcet was associated with sustained, clinically significant reductions in calcium, Ca x P and iPTH which allowed a greater percentage of patients to achieve NKF-KDOQI target goals for PTH and Ca x P.

Selenium and the immune response: 2. Enhancement of murine cytotoxic T-lymphocyte and natural killer cell cytotoxicity in vivo.

An inverse correlation between cancer incidence and dietary intake of the trace mineral element selenium has been well established in epidemiological and experimental studies. The mechanisms for this chemoprotective effect are unresolved. Much attention has been focused on the antiproliferative effects of selenium on various normal and neoplastic cell types. However, dietary selenium supplementation can also enhance the expression of various humoral and cellular immune responses. In examining the effects of dietary selenium on cell-mediated immunity in mice, we observed that selenium supplementation caused the enhanced expression of spontaneous natural killer (NK) cytotoxicity in spleen cells and of specific cytotoxic T-lymphocyte (CTL) cytotoxicity in peritoneal exudate cells (PEC). NK activity of spleen-cell suspensions from selenium-supplemented mice increased an average of 70% over that of the control group (basal diet). Cytotoxic activity of PEC from mice injected with tumors intraperitoneally peaked earlier in selenium-supplemented animals, and the appearance of cells staining positively for Thy 1.2 surface antigen in selenium-supplemented animals also preceded the values observed in control animals. We propose here that enhancement of in vivo cytotoxic mechanisms, is likely to act synergistically with tumor growth inhibition in the reduction of tumor incidence associated with selenium intake.

Patient-reported quality of life in a randomized placebo-controlled trial of naltrexone/bupropion for obesity.

Weight loss is associated with improved quality of life in some, but not all, weight loss trials. We evaluated changes at 56 weeks in quality of life, measured by the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) questionnaire, in a pooled analysis of patient-level data from four randomized controlled Phase 3 studies of naltrexone/bupropion (NB32 or Contrave®). The total number of subjects was 3362 (NB32 = 2043; placebo = 1319; mean body mass index = 36.3 kg m(2); mean age = 46). Improvements in IWQOL-Lite Total Score were greater in subjects treated with NB32 (11.9 points [SE 0.3]) vs. placebo (8.2 points [SE 0.3]; P < 0.001), corresponding to weight reductions of 7.0% (SE 0.2) and 2.3% (SE 0.2), respectively. Greater improvements were also observed for NB32 vs. placebo on all five subscale scores of the IWQOL-Lite. Fifty per cent of NB32-treated subjects achieved clinically meaningful improvements in IWQOL-Lite Total Score vs. 32.3% of placebo-treated subjects (odds ratio, 95% confidence interval; 2.09, 1.79-2.44). Subjects losing the most weight (≥ 15% of baseline weight) experienced the greatest improvement in IWQOL-Lite Total Score (19.3 points [SE 0.7] for NB32 and 18.7 points [SE 1.3] for placebo; P = 0.624). Improved quality of life was associated with weight reduction and was achieved in more subjects treated with NB32 than placebo.

Plasma free amino acid concentrations in healthy Guatemalan adults and in patients with classic dengue.

BACKGROUND: Plasma free amino acid patterns in health and disease have been reported. However, amino acid concentrations in adult populations in developing countries and in patients with dengue, as a model for an acute infectious viral disease endemic to the tropics, have not been reported. OBJECTIVE: The purpose of this study was to determine the amino acid profile in both healthy Guatemalan adults from different socioeconomic backgrounds and at 3 time points during the course of classic dengue. DESIGN: The study was carried out in Guatemala and included measurement of plasma free amino acids in 22 healthy control subjects (14 low income, 8 middle class) and 17 febrile patients. Measurements of amino acids were repeated within a 48-h interval in 20 of the healthy Guatemalans. In 9 patients with dengue, amino acids were assayed 3 times: on admission to a local hospital in the coastal plain of Guatemala, on hospital discharge, and 7 d after hospital discharge. RESULTS: Branched-chain amino acid concentrations in healthy adults and dengue patients in Guatemala were lower than normal values reported in the literature for healthy Swedish adults. With the exception of increased phenylalanine concentrations and an increased ratio of phenylalanine to tyrosine, all amino acids as well as the Fischer molar ratio were decreased in the acute phase of dengue. CONCLUSIONS: Healthy Guatemalans have different amino acid patterns than do Swedish subjects independent of socioeconomic status. The systemic viral disease dengue is associated with changes in the plasma free amino acid pattern, reflecting infection-related alterations in amino acid metabolism.

Diagnosis and management of BK polyomavirus interstitial nephritis in renal transplant recipients.

BACKGROUND: Interstitial nephritis caused by BK polyomavirus is a recognized complication of renal transplantation. A study of renal transplant recipients at Duke University Medical Center was undertaken to evaluate diagnostic modalities and assess clinical outcomes in transplant polyomavirus infections. METHODS: Polyomavirus nephritis was identified in 6 of 240 patients who received renal transplants between January 1996 and June 1998 and an additional patient who underwent transplantation in 1995. The clinical records of these seven patients were reviewed, as were all renal biopsy and nephrectomy specimens. Electron microscopy (EM) was performed on negatively stained urine samples from 6 patients with polyomavirus infection and 23 patients with other diagnoses. RESULTS: Patients with polyomavirus infection shared several clinical features, including ureteral obstruction (5/7 patients), lymphocele (3/7), bacterial urinary tract infection (3/7), hematuria (3/7), cytomegalovirus infection (3/7), and immunosuppression with mycophenolate mofetil (6/7). All patients experienced elevations in serum creatinine, which stabilized or decreased in four patients with altered or decreased immunosuppression. The diagnosis of polyomavirus infection was established by renal biopsy and EM of urine in five patients, by biopsy alone in one, and by EM alone in one. Sequential examinations of urine by EM were used to monitor the course of infection in six patients. CONCLUSIONS: Interstitial nephritis due to BK polyomavirus occurred in 2.5% of patients receiving renal transplants at our center since 1996. Polyomavirus infection can cause transplant dysfunction and graft loss, but progression of the infection can frequently be abrogated with alterations in immunosuppressive therapy. Both renal biopsy and EM of urine samples are useful in the diagnosis and monitoring of polyomavirus infections.

Hydrational status assessed by bioelectrical impedance spectroscopy and dilution methods in patients with classical dengue fever.

The effects of an episode of acute classical dengue fever on extracellular water (ECW), intracellular water (ICW), and total body water (TBW) were measured in nine patients using conventional dilution techniques; and the findings were compared with the outcome variables from whole body impedance spectroscopy (BIS), extracellular fluid resistance (Recf), and intracellular fluid resistance (Ricf). The patients were assessed on admission with febrile presentation (DI), at discharge after the defervescence of the fever cycle at about five days postadmission (DII), and seven days thereafter (DIII). As a reference group, 15 persons without acute or chronic illness were enrolled. Total body water was unaltered during the course of disease and was not different from that in normal healthy subjects. However, body water shifted from the intracellular to the extracellular compartment in patients from the acute phase to convalescence, as reflected in the ratios of ECW/TBW and ECW/ICW. These ratios were significantly higher in convalescent dengue patients (DIII) than in the reference group (p < 0.05). Increasing ECW, from the acute phase of the disease to convalescence, was associated with a significant decrease in Recf (719 +/- 95, 693 +/- 89, 643 +/- 81 omega; p < 0.0001) and in Recf/Ricf (p < 0.01). Recf and Recf/Ricf were higher in the acute phase (DI) of dengue fever compared to controls (p < 0.05). We conclude that dengue fever is characterized by a relative expansion of ECW during the course of disease and convalescence. BIS was sensitive in determining the hydrational profile in dengue fever patients.

Bioelectrical impedance spectroscopy in health and disease. Correspondence between whole body and segmental bioelectrical impedance spectroscopy indices in patients with classical dengue fever.

Bioelectrical impedance spectroscopy (BIS) can provide estimates of body composition for both whole body (WB) and body segments (BS). In normal, healthy subjects, BS measurements may be expected to serve as surrogates for WB indices; however, very little is known about this correspondence in people suffering from acute illnesses. The aim of this study was to evaluate the degree of this correspondence in patients with an acute, systemic illness, such as classical dengue fever. Ten adult patients were examined upon admission to the community hospital on the Pacific Coast of Guatemala and after clinical recovery about two weeks later, and compared with a group of healthy subjects living in the same region. BIS was measured with a Xitron 4000B analyzer (Xitron Technologies Inc., San Diego, CA, USA). BS measurements were carried out using Organ et al.'s approach. The BIS data were modeled with the manufacturer's software: extra- (Recf) and intracellular- (Ricf) resistances, and the Recf/Ricf ratio. BIS BS measurements correlate closely with WB in both the acute and the recovery stages of dengue fever, with the leg showing the highest degree of correspondence and the trunk the lowest. Recf indices, per se, generally showed higher correspondence than Ricf or the Recf/Ricf ratio.

Haemodynamic modelling for the arterial pulsatile component of the intracranial pulse wave.

Vasospasm of cerebral arteries narrows the amplitude of the intracranial pressure wave, indicating that the arterial segment of the cerebral circulation is partially responsible for its formation. We investigated the fundamental mechanism of pressure pulse transmission from an artery to the surrounding environment. A mathematical model was derived expressing the amplitude of container pulsation (delta Po) as a function of mean intraluminal pressure (MPi), mean container pressure (MPo) and arterial pulse amplitude (delta Pi): delta Po = (-2(MPi - MPo) + b) (MPo + 1) delta Pi. This mathematical model was experimentally validated using an in vivo system of a single artery sealed inside a fluid-filled elastic container.

Diagnosis and management of renovascular hypertension.

Renovascular hypertension caused by renal artery stenosis accounts for a small portion of overall hypertension but remains important as the most common potentially curable form of high blood pressure. Diagnosis depends on developing an index of suspicion for renovascular hypertension based on the history and physical exam, as well as judicious use of noninvasive and invasive testing. Determining which noninvasive diagnostic test to use remains a persistent dilemma. Treatment options include renal artery angioplasty, arterial stenting, surgery, and medical therapy. The goals of therapy are reduction of blood pressure and protection of renal function. This review discusses the pathophysiology and epidemiology of renovascular hypertension, various noninvasive tests used in diagnosis, and results offered by different treatment modalities. A diagnostic and therapeutic algorithm is offered based on a review of the literature and the experience at our institution.

Intestinal helminths and their influence on the indicators of iron status in the elderly.

The intestinal helminthiasis and hematological status was assessed in 100 elderly residents of two low-land communities, one at sea-level and the other at 61; m, equally representative of men and women. These are beth low-income communities. The population showed a 48% helminth infection rate which consisted of hookworm, Trichuris, and Ascaris infection. The prevalence of each of the individual parasites was considered light to moderate and the intensity of infection was generally low in this population. A strong inverse association between intensity of hookworm infection and hemoglobin levels was observed but only at intensities greater than 2,000 eggs/gram feces. Lower intensities of infection had no apparent influence on hematological status. The evaluation of hematological status using hematocrit and hemoglobin showed different prevalences of risk of anemia of 14.1% and 43.8%, respectively. These differences may reflect the chosen cut-off values. Iron deficiency does not appear to be a major problem in this population with only 5% or 11% having absent stores using the low and high cut-off values of circulating serum ferritin, respectively.

Sensitivity and specificity of the phallometric test for pedophilia in nonadmitting sex offenders.

The specificity of phallometric testing for pedophilia has been calculated using sex offenders against adult women. Does the offender's actual number of prior sexual contacts with women affect such estimates? To answer this, the authors' studied 82 male sex offenders against adult women, 172 offenders against unrelated children, and 70 offenders against their own biological children or stepchildren. Phallometric testing included visual and auditory depictions of prepubescent, pubescent, and adult males and females. The results for offenders against women showed that those who had had sexual contact with the greatest number of women (consenting or nonconsenting) had the lowest probability of being diagnosed as pedophilic. Specificity, calculated for those who had sexual contact with the most women and thus the most evidence of attraction to them, was 96%. Sensitivity, calculated analogously for men with the most offenses against children, was 61%.

[Diarrhea]. / Diarrhöe.

A 54-year-old man had recurrent watery diarrhea with up to 10 stools per day for 4 years. The initial evaluation including coloscopy did not disclose a pathologic finding. The symptoms subsided initially after four weeks. Three years later massive watery diarrhea recurred with up to fifteen daily stools. A reevaluation of the patient disclosed the diagnosis of collagen colitis in the colonic biopsy.