Observation of X-ray lines from a gamma-ray burst (GRB991216): evidence of moving ejecta from the progenitor

We report on the discovery of two emission features observed in the x-ray spectrum of the afterglow of the gamma-ray burst (GRB) of 16 December 1999 by the Chandra X-ray Observatory. These features are identified with the Ly(alpha) line and the narrow recombination continuum by hydrogenic ions of iron at a redshift z = 1.00 +/- 0.02, providing an unambiguous measurement of the distance of a GRB. Line width and intensity imply that the progenitor of the GRB was a massive star system that ejected, before the GRB event, a quantity of iron approximately 0.01 of the mass of the sun at a velocity approximately 0.1 of the speed of light, probably by a supernova explosion.

Measurement of the rate of nu(e) + d --> p + p + e(-) interactions produced by (8)B solar neutrinos at the Sudbury Neutrino Observatory

Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).

Direct evidence for neutrino flavor transformation from neutral-current interactions in the Sudbury Neutrino Observatory

Observations of neutral-current nu interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard 8B shape, the nu(e) component of the 8B solar flux is phis(e) = 1.76(+0.05)(-0.05)(stat)(+0.09)(-0.09)(syst) x 10(6) cm(-2) s(-1) for a kinetic energy threshold of 5 MeV. The non-nu(e) component is phi(mu)(tau) = 3.41(+0.45)(-0.45)(stat)(+0.48)(-0.45)(syst) x 10(6) cm(-2) s(-1), 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC) = 5.09(+0.44)(-0.43)(stat)(+0.46)(-0.43)(syst) x 10(6) cm(-2) s(-1), consistent with solar models.

Discovery of a transient absorption edge in the X-ray spectrum of GRB 990705

We report the discovery of a transient equivalent hydrogen column density with an absorption edge at approximately 3.8 kiloelectron volts in the spectrum of the prompt x-ray emission of gamma-ray burst (GRB) 990705. This feature can be satisfactorily modeled with a photoelectric absorption by a medium located at a redshift of approximately 0.86 and with an iron abundance of approximately 75 times the solar one. The transient behavior is attributed to the strong ionization produced in the circumburst medium by the GRB photons. The high iron abundance points to the existence of a burst environment enriched by a supernova along the line of sight. The supernova explosion is estimated to have occurred about 10 years before the burst. Our results agree with models in which GRBs originate from the collapse of very massive stars and are preceded by a supernova event.

Decay of the GRB 990123 optical afterglow: implications for the fireball model

Broad-band (ultraviolet to near-infrared) observations of the intense gamma ray burst GRB 990123 started approximately 8.5 hours after the event and continued until 18 February 1999. When combined with other data, in particular from the Robotic Telescope and Transient Source Experiment (ROTSE) and the Hubble Space Telescope (HST), evidence emerges for a smoothly declining light curve, suggesting some color dependence that could be related to a cooling break passing the ultraviolet-optical band at about 1 day after the high-energy event. The steeper decline rate seen after 1.5 to 2 days may be evidence for a collimated jet pointing toward the observer.

Measurement of day and night neutrino energy spectra at SNO and constraints on neutrino mixing parameters

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.

Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

Prospective comparison between double-balloon enteroscopy and spiral enteroscopy

BACKGROUND AND STUDY AIMS

Push enteroscopy, balloon-guided, and single- and double-balloon enteroscopy (DBE) are now well established techniques in gastrointestinal endoscopy for small-bowel imaging and therapy. There are no published prospective studies comparing DBE with spiral enteroscopy and so the aim of the current study was to compare the performance of the two techniques in patients undergoing diagnostic enteroscopy.

PATIENTS AND METHODS

Between January and December 2009, 35 patients referred for diagnostic enteroscopy were prospectively assigned to either spiral enteroscopy (n=18) or DBE (n=17). The performance of the two techniques was compared.

RESULTS

The patients were comparable with regard to age, sex, and indication for enteroscopy. Investigation performance, as assessed by time of insertion into the pylorus, the depth of insertion, the duration of the enteroscopy, and the amount of sedoanalgesia required were not significantly different between spiral enteroscopy and DBE. In 40% of the investigations, enteroscopy could detect abnormalities in the intestinal mucosa, in particular inflammatory changes and ulcers and, to a lesser extent, angiodysplasia. No significant difference in pathological findings could be detected between the two groups; however, clinically, diagnostic yield appeared to be higher for DBE (47.1% vs. 33.4%; n.s.).

CONCLUSION

Although this small study appears to show that DBE has a clinically higher diagnostic yield than spiral enteroscopy, larger studies are needed to confirm this preliminary finding.

Sedation-associated complications in endoscopy--prospective multicentre survey of 191142 patients

BACKGROUND/AIMS

Propofol sedation is applied as moderate sedation for almost all diagnostic and interventional endoscopies. Propofol sedation bears the risk of complications such as respiratory as well as cardiopulmonary insufficiency including sedation-induced death. According to recent guidelines, non-anesthesiologist-administered propofol (NAAP) should be performed by an additional person who has NAAP as their sole task.

METHODS

In a prospective multicentre survey involving 191,142 patients, clinically relevant endoscopy-associated complications were registered from 02/2010 to 01/2012.

RESULTS

The majority of propofol sedations were applied without additional persons for NAAP. Overall endoscopy-related complication rate was 0.0022 % (n = 424) and sedation-related complications 0.00 042 % (n = 82). Variability over time and between the clinics was low and not influenced by the number of endoscopies performed during the investigation period. Sedation-related death occurred in 6 patients (0.00 003 %), 50 % during emergency endoscopies. In all sedation-associated deaths the patients had ASA class 3 before endoscopy. All fatal complications occurred in the presence of an additional trained person for NAAP.

CONCLUSION

This large prospective survey shows that propofol sedation in gastrointestinal endoscopy is a safe procedure with a low potential of risk in daily routine. However, high risk patients (ASA ≥ 3) should be identified, especially before emergency endoscopies and managed by additional persons for NAAP and under intensive care surveillance.

Fructose malabsorption: how much fructose can a healthy subject tolerate?

BACKGROUND/AIMS

In a prospective study, we evaluated fructose absorption capacity in 17 healthy female volunteers aged 16-27 years.

METHODS

All volunteers underwent analysis of their daily food intake diary and standardized breath tests. The volunteers were challenged consecutively with oral intake of 50, 25 and 15 g of fructose.

RESULTS

The average daily ingestion of fructose (19.54 ± 14.95 g) was not different between volunteers with positive and negative breath tests. On day 1, 53% of subjects exhibited a significant (≥20 ppm) increase in breath hydrogen and gastrointestinal symptoms upon challenge with 50 g of fructose. Moreover, 37.5% of the volunteers with a negative breath test became positive upon a second challenge with 50 g of fructose but remained asymptomatic. On day 2, 1 of the 9 volunteers (12.5%) with a positive breath test on day 1 exhibited an asymptomatic positive breath test upon exposure to 25 and 15 g of fructose on day 3. The 8 volunteers with a negative test (25 g of fructose) remained negative after a second exposure to 25 g of fructose.

CONCLUSION

The results of this study indicate that hydrogen breath tests with fructose challenge of 50 g of fructose are inappropriate to characterize clinically significant fructose malabsorption.

Phenotypic and genetic relationships between age at first calving, its component traits, and survival of heifers up to second calving

The aim of this study was to answer the question whether models for genetic evaluations of longevity should include a correction for age at first calving (AFC). For this purpose, phenotypic and genetic relationships between AFC, its component traits age at first insemination (AFI) and interval from first to last insemination (FLI), and survival of different periods of the first lactation (S1: 0 to 49 d, S2: 50 to 249 d, S3: 250 d to second calving) were investigated. Data of 721,919 German Holstein heifers, being inseminated for the first time during the years from 2003 to 2012, were used for the analyses. Phenotypic correlations of AFI, FLI, and AFC to S1 to S3 were negative. Mean estimated heritabilities were 0.239 (AFI), 0.007 (FLI), and 0.103 (AFC) and 0.023 (S1), 0.016 (S2), and 0.028 (S3) on the observed scale. The genetic correlation between AFI and FLI was close to zero. Genetic correlations between AFI and the survival traits were -0.08 (S1), -0.02 (S2), and -0.10 (S3); those between FLI and the survival traits were -0.14 (S1), -0.20 (S2), and -0.44 (S3); and those between AFC and the survival traits were -0.09 (S1), -0.06 (S2), and -0.20 (S3). Some of these genetic correlations were different from zero, which suggests that correcting for AFC in genetic evaluations for longevity in dairy cows might remove functional genetic variance and should be reconsidered.

Prospective and randomized study to evaluate the clinical impact of cap assisted colonoscopy (CAC)

BACKGROUND

Although colonoscopy is the standard procedure in the diagnosis of colorectal neoplasia, a significant number of clinical relevant lesions may be missed even by experienced endoscopists using current technology. A transparent cap mounted at the tip of a colonoscope may be an easy way to extend the visual field during colonoscopy and may improve the detection rate of mucosal lesions.

MATERIAL AND METHODS

The significance of cap assisted (CAC) vs. conventional colonoscopy (CC) on polyp detection rate was evaluated in a prospective randomized controlled trial in 504 patients.

RESULTS

CC and CAC detected polyps in 39.3 % and 31.8, not significantly different. There was also no significant difference between CAC and CC according to age, sex, indication for colonoscopy, diverticulosis, sedation, bowel cleansing, withdrawal time, time/number of attempts to intubate the cecal walve, number, localization, size or histology of polyps,. However, the time to reach the cecal floor and the overall time of colonoscopy were significantly lower for CAC (1 minute).

CONCLUSION

CAC was without clinical impact on polyp detection rate or performance of colonoscopy.

Neoadjuvant chemotherapy versus surgery alone for locally advanced adenocarcinoma of the stomach and cardia: Randomized EORTC phase III trial #40954

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Background: Combined pre- and postoperative chemotherapy improves overall survival in operable gastric cancer, although postoperative treatment is not feasible in half of the patients. We conducted a randomized phase III trial with thorough attention to preoperative staging and to the extent of surgical resection to assess the value of neoadjuvant chemotherapy (CTx). Methods: Patients with locally advanced adenocarcinoma of the stomach and cardia were randomized between primary surgery or two 48-day cycles of weekly folinic acid 500 mg/m2/2h, 5-FU 2,000 mg/m2/24h plus biweekly cisplatin 50 mg/m2/1h followed by surgery. The study was designed to detect an improvement in median survival from 17 months with surgery to 24 months with CTx plus surgery (HR=0.708, power of 80%, type I error of 4% to allow for an interim analysis). It was planned to randomize 360 patients in order to observe the 262 deaths required for the final analysis. Results: From 7/99 to 2/04, 144 patients were randomized (72:72) with comparable baseline characteristics. Median follow-up is 4.4 years. Based on 67 deaths, overall survival between the two arms did not differ (HR=0.84; 95% CI: 0.52 to 1.35; p=0.466). Median survival exceeded 36 months in both arms. Due to low accrual, this trial was stopped early. The unexpected long median survival in the surgery arm would have made the primary objective difficult to reach anyway. Based on 77 events, difference in time to progression was borderline significant (HR=0.66; 95% CI, 0.42–1.03; p=0.065). Response rate to CTx was 35.2% (95% CI: 23.7%-45.7%). The R0-resection rate was 81.9 % after CTx as compared to 66.7% with surgery alone (P=0.036). There were no major differences in intra- or postoperative complications. Conclusions: This prematurely closed trial showed a significantly increased rate of R0 resections after CTx although it could not demonstrate a survival benefit. The outcome after a radical surgical procedure alone with extended lymphadenectomy was better than expected.

No significant financial relationships to disclose.

Relief of reflux symptoms after endoscopic gastroplication may be associated with reduced esophageal Acid sensitivity: a pilot study

BACKGROUND AND STUDY AIMS

Although the new endoscopic techniques for the treatment of gastroesophageal reflux disease (GERD) lead to marked clinical benefit, the underlying mechanism of this is unknown.

MATERIALS AND METHODS

In this prospective study, the effect of endoscopic gastroplication was investigated in six patients with GERD, who were assessed before and 4 weeks after treatment. The effect on reflux symptoms, quality of life, proton pump inhibitor (PPI) consumption, reflux esophagitis, acid exposure, esophageal motility, lower esophageal sphincter pressure (LESP), and gastric emptying was measured. Esophageal acid sensitivity before and after treatment was investigated using a standardized acid provocation test, and compared with that of six age- and sex-matched healthy controls.

RESULTS

Significant clinical benefit and discontinuation of PPI consumption after gastroplication was seen. Among the objectively measured parameters, only acid exposure was significantly reduced and gastric emptying significantly delayed. However, acid exposure remained pathologically high. Esophageal acid sensitivity was significantly reduced. The induction of heartburn and/or pain was abolished in four patients after gastroplication. In two patients the intensity of heartburn/pain was significantly reduced by 40 % or 60 %, and the time to provoke heartburn/pain significantly prolonged by 40% or 100%.

CONCLUSION

These preliminary data suggest that the decrease of esophageal sensitivity to acid after endoscopic gastroplication is part of the mechanism responsible for the reduction of reflux symptoms.

Activity of polymorphonuclear (PMN) leukocytes during bovine herpes virus-1 induced respiratory disease: effect of recombinant bovine interferon alpha I1

Following infection of cattle with bovine herpes virus-1 there is a state of generalized immunosuppression involving various leukocytes including polymorphonuclear (PMN) leukocytes. Since the PMN is considered to be pivotal in recovery from secondary bacterial infections during bovine respiratory disease, investigations were initiated to determine PMN activity in this disease and whether interferon could modulate PMN activity. In this study, the in vivo administration of recombinant interferon alpha-I1 was shown to increase PMN functions as measured by migration/chemotaxis and generation of reactive oxygen species. This augmented activity of PMN appeared to correlate with the reduction of overall clinical disease, that is, number of sick days, lung lesions and weight loss. In the study administration of interferon by the intranasal or intramuscular route were as effective in stimulating PMN function. Based on these studies it was concluded that the reason for improved performance of calves treated with interferon would be due to its immunomodulatory effects on leukocytes. Although interferon did not alter the initial suppression of PMN functions, these functions returned to normal and exceeded normal activities by 7-9 days post-infection, the time when maximal bacterial activity normally is present.

Multiple colon ulcerations, perforation and death during treatment of malignant melanoma with sorafenib

BACKGROUND

Sorafenib (Nexavar) is an oral multi-kinase inhibitor with anti-angiogenic and antiproliferative effects. It has shown in-vitro and clinical activity against several kinds of tumors, such as malignant melanoma.

HISTORY, DIAGNOSIS, TREATMENT AND COURSE

A 66-year-old man with malignant melanoma was treated with sorafenib, 2 yen 400 mg per day. Because of severe diarrhea and abdominal pain, sorafenib was eventually discontinued and the patient was hospitalized for further treatment. Diagnostic work-up by upper gastrointestinal endoscopy and colonoscopy revealed multiple deep ulcerations within the whole colon. One week after admission the patient developed symptoms of acute abdomen with signs of bowel perforation requiring an emergency operation. Colectomy of the right colon with ileostomy revealed multiple (20-30) acute and subacute colonic perforations. Despite intensive care treatment the patient died of septic complications 13 days after surgery.

CONCLUSION

Treatment with anti-angiogenic multi-kinase inhibitors may be associated with gastrointestinal perforations. This has been reported for sorafenib in up to 2.3 % of cases.