Recent results from the KASCADE-Grande data analysis

KASCADE, together with its extension KASCADE-Grande measured individual air showers of cosmic rays in the primary energy range of 100 TeV to 1 EeV. The data collection was fully completed at the end of 2013 and the experiment was dismantled. However, the data analysis is still in progress. Recently, we published a new result on upper limits to the flux of ultra-high energy gamma rays, which set constraints on some fundamental astrophysical models. We also use the data to investigate the validity of the new hadronic interactions models like SIBYLL version 2.3c or EPOS-LHC. In addition, we updated and improved the webbased platform of the KASCADE Cosmic Ray Data Centre (KCDC), where now the data from KASCADE and KASCADE-Grande of more than 20 years measurements is available, including corresponding Monte-Carlo simulated events based on three different hadronic interaction models. In this contribution, recent results from KASCADE-Grande and the update of KCDC is briefly discussed.

Study of themuon content of high-energy air showers with KASCADE-Grande

In this work, we report measurements on the muon content (Eth > 230 MeV) of extensive air showers (EAS) induced by cosmic rays with primary energy from 10 PeV up to 1 EeV performed with the KASCADE-Grande experiment. The measurements are confronted with SIBYLL 2.3. The results are focused on the dependence of the total muon number and the lateral density distribution of muons in EAS on the zenith angle and the total number of charged particles in the shower. We also present updated results of a detailed study of the attenuation length of shower muons, which reveal a deviation between the measured data and the predictions of the post-LHC hadronic interaction models SIBYLL 2.3, QGSJET-II-04 and EPOS-LHC.

Summary of the main results of the KASCADE and KASCADE-Grande experiments

The KASCADE and KASCADE-Grande experiments operated in KIT-Campus North, Karlsruhe (Germany) from 1993 to 2012. The two experiments studied primary cosmic rays in the energy range from 1014 eV to 1018 eV, investigating the change of slope of the spectrum detected at 2 - 4 × 1015 eV, the so called knee. We briefly review the performance of the experiments and then the main results obtained in the operation of both experiments: the test of hadronic interaction models, the all particle primary spectrum, the elemental composition of primary cosmic rays (with the first claim of a knee-like feature of the heavy primaries spectrum) and the search for large scale anisotropies.

High risk of hypogonadism in young male cancer survivors

OBJECTIVE

Cancer and its treatment in childhood and young adulthood can cause hypogonadism, leading to increased risk of long-term morbidity and mortality. The aim of this study was to evaluate the risk of presenting with biochemical signs of hypogonadism in testicular cancer survivors (TCS) and male childhood cancer survivors (CCS) in relation to the type of treatment given.

DESIGN

Case-control study.

PATIENTS

Ninety-two TCS, 125 CCS (mean age 40 and median age 34 years, respectively; mean follow-up time 9.2 and 24 years, respectively) and a corresponding number of age-matched controls.

MEASUREMENTS

Fasting morning blood samples were analysed for total testosterone (TT), follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The odds ratios (OR) for hypogonadism, defined as primary, secondary, compensated or ongoing androgen replacement, were calculated for TCS and CCS and for subgroups defined by diagnosis and treatment.

RESULTS

Hypogonadism was found in 26% of CCS and 36% of TCS, respectively (OR: 2.1, P = .025 and OR = 2.3, P = .021). Among CCS, the OR was further increased in those given testicular irradiation (OR = 28, P = .004). Radiotherapy other than cranial or testicular irradiation plus chemotherapy, or cranial irradiation without chemotherapy, associated also with increased ORs (OR = 3.7, P = .013, and OR = 4.4, P = .038, respectively). Among TCS, those receiving >4 cycles of cisplatin-based chemotherapy had OR = 17, P = .015.

CONCLUSIONS

Biochemical signs of testosterone deficiency are recognized as markers of decreased life expectancy. Thus, the risk of hypogonadism in TCS and CCS should be recognized and emphasizes the need of long-term follow-up for these men.

Tests of the SIBYLL 2.3 high-energy hadronic interaction model using the KASCADE-Grande muon data

The KASCADE-Grande observatory was a ground-based air shower array dedicated to study the energy and composition of cosmic rays in the energy interval E = 1 PeV –1 EeV. The experiment consisted of different detector systems which allowed the simultaneous measurement of distinct components of air showers (EAS), such as the muon content. In this contribution, we study the total muon number and the lateral density distribution of muons in EAS detected by KASCADE-Grande as a function of the zenith angle and the total number of charged particles. The attenuation length of the muon content of EAS is also measured. The results are compared with the predictions of the SIBYLL 2.3 high-energy hadronic interaction model.

Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory

Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (E_{CM}=110-170  TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8±0.7(stat)±6.7(syst)  MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

Modeling Immune Response to BK Virus Infection and Donor Kidney in Renal Transplant Recipients

In this paper we develop and validate with bootstrapping techniques a mechanistic mathematical model of immune response to both BK virus infection and a donor kidney based on known and hypothesized mechanisms in the literature. The model presented does not capture all the details of the immune response but possesses key features that describe a very complex immunological process. We then estimate model parameters using a least squares approach with a typical set of available clinical data. Sensitivity analysis combined with asymptotic theory is used to determine the number of parameters that can be reliably estimated given the limited number of observations.

Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with [Formula: see text] eV by analyzing cosmic rays with energies above [Formula: see text] eV arriving within an angular separation of approximately 15[Formula: see text]. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.

Model Comparison Tests to Determine Data Information Content

In the context of inverse or parameter estimation problems we demonstrate the use of statistically based model comparison tests in several examples of practical interest. In these examples we are interested in questions related to information content of a particular given data set and whether the data will support a more complicated model to describe it. In the first example we compare fits for several different models to describe simple decay in a size histogram for aggregates in amyloid fibril formation. In a second example we investigate whether the information content in data sets for the pest Lygus hesperus in cotton fields as it is currently collected is sufficient to support a model in which one distinguishes between nymphs and adults. Finally in a third example with data for patients having undergone an organ transplant, we question whether the data content is sufficient to estimate more than 5 of the fundamental parameters in a particular dynamic model.

First Experimental Characterization of Microwave Emission from Cosmic Ray Air Showers

We report the first direct measurement of the overall characteristics of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the signals of the microwave antennas of the Cosmic-Ray Observation via Microwave Emission experiment have been read out and searched for signatures of radio emission by high-energy air showers in the GHz frequency range. Microwave signals have been detected for more than 30 showers with energies above 3×10^{16}  eV. The observations presented in this Letter are consistent with a mainly forward-directed and polarized emission process in the GHz frequency range. The measurements show that microwave radiation offers a new means of studying air showers at E≥10^{17}  eV.

Compression and venous ulcers

Compression therapy is considered to be the most important conservative treatment of venous leg ulcers. Until a few years ago, compression bandages were regarded as first-line therapy of venous leg ulcers. However, to date medical compression stockings are the first choice of treatment. With respect to compression therapy of venous leg ulcers the following statements are widely accepted: (1) Compression improves the healing of ulcers when compared with no compression; (2) Multicomponent compression systems are more effective than single-component compression systems; (3) High compression is more effective than lower compression; (4) Medical compression stockings are more effective than compression with short stretch bandages.

Healed venous leg ulcers show a high relapse rate without ongoing treatment. The use of medical stockings significantly reduces the amount of recurrent ulcers. Furthermore, the relapse rate of venous leg ulcers can be significantly reduced by a combination of compression therapy and surgery of varicose veins compared with compression therapy alone.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.

A comparison of computational efficiencies of stochastic algorithms in terms of two infection models

In this paper, we investigate three particular algorithms: a stochastic simulation algorithm (SSA), and explicit and implicit tau-leaping algorithms. To compare these methods, we used them to analyze two infection models: a Vancomycin-resistant enterococcus (VRE) infection model at the population level, and a Human Immunodeficiency Virus (HIV) within host infection model. While the first has a low species count and few transitions, the second is more complex with a comparable number of species involved. The relative efficiency of each algorithm is determined based on computational time and degree of precision required. The numerical results suggest that all three algorithms have the similar computational efficiency for the simpler VRE model, and the SSA is the best choice due to its simplicity and accuracy. In addition, we have found that with the larger and more complex HIV model, implementation and modification of tau-Leaping methods are preferred.

Kneelike structure in the spectrum of the heavy component of cosmic rays observed with KASCADE-Grande

We report the observation of a steepening in the cosmic ray energy spectrum of heavy primary particles at about 8×10(16) eV. This structure is also seen in the all-particle energy spectrum, but is less significant. Whereas the "knee" of the cosmic ray spectrum at 3-5×10(15) eV was assigned to light primary masses by the KASCADE experiment, the new structure found by the KASCADE-Grande experiment is caused by heavy primaries. The result is obtained by independent measurements of the charged particle and muon components of the secondary particles of extensive air showers in the primary energy range of 10(16) to 10(18) eV. The data are analyzed on a single-event basis taking into account also the correlation of the two observables.

GAD65 vaccination: 5 years of follow-up in a randomised dose-escalating study in adult-onset autoimmune diabetes

AIMS/HYPOTHESIS

The aim of this study was to ascertain whether treatment of GAD65 autoantibody (GADA)-positive diabetic patients with alum-formulated recombinant GAD65 (GAD-alum) is safe and does not compromise beta cell function.

METHODS

This Phase 2, placebo-controlled, dose-escalation clinical trial, which was randomized through a central office, was performed in 47 GADA-positive type 2 diabetic patients, who received subcutaneous injections of GAD-alum (4 [n = 9], 20 [n = 8], 100 [n = 9] or 500 [n = 8] microg) or placebo (n = 13) at weeks 1 and 4 of the trial. Participants and caregivers were blinded to group assignments. The primary outcome was safety as assessed by neurological tests, medications and beta cell function evaluated over 5 years, representing the end of the trial.

RESULTS

No severe study-related adverse events occurred during the 5 year follow-up. None of the dose groups was associated with an increased risk of starting insulin treatment compared with the placebo group. The use of oral hypoglycaemic agents did not differ between the dose groups. After 5 years, fasting C-peptide levels declined in the placebo group (-0.24; 95% CI -0.41 to -0.07 log(10) nmol/l; p = 0.01) and the 500 microg dose group (-0.37; 95% CI -0.57 to -0.17 log(10) nmol/l; p = 0.003), but not in the 4 microg (-0.10; 95% CI -0.28 to 0.07 log(10) nmol/l; p = 0.20), 20 microg (0.04; 95% CI -0.12 to 0.19 log(10) nmol/l; p = 0.58) and 100 microg (0.00; 95% CI -0.20 to -0.20 log(10) nmol/l; p = 0.98) dose groups.

CONCLUSIONS/INTERPRETATION

The primary outcome of safety was achieved, since no severe study-related adverse events occurred.

TRIAL REGISTRATION

Because the study was initiated before 1 July 2005, the protocol was not registered in a registry.

Association of gene-linked SSR markers to seed glucosinolate content in oilseed rape (Brassica napus ssp. napus)

Breeding of oilseed rape (Brassica napus ssp. napus) has evoked a strong bottleneck selection towards double-low (00) seed quality with zero erucic acid and low seed glucosinolate content. The resulting reduction of genetic variability in elite 00-quality oilseed rape is particularly relevant with regard to the development of genetically diverse heterotic pools for hybrid breeding. In contrast, B. napus genotypes containing high levels of erucic acid and seed glucosinolates (++ quality) represent a comparatively genetically divergent source of germplasm. Seed glucosinolate content is a complex quantitative trait, however, meaning that the introgression of novel germplasm from this gene pool requires recurrent backcrossing to avoid linkage drag for high glucosinolate content. Molecular markers for key low-glucosinolate alleles could potentially improve the selection process. The aim of this study was to identify potentially gene-linked markers for important seed glucosinolate loci via structure-based allele-trait association studies in genetically diverse B. napus genotypes. The analyses included a set of new simple-sequence repeat (SSR) markers whose orthologs in Arabidopsis thaliana are physically closely linked to promising candidate genes for glucosinolate biosynthesis. We found evidence that four genes involved in the biosynthesis of indole, aliphatic and aromatic glucosinolates might be associated with known quantitative trait loci for total seed glucosinolate content in B. napus. Markers linked to homoeologous loci of these genes in the paleopolyploid B. napus genome were found to be associated with a significant effect on the seed glucosinolate content. This example shows the potential of Arabidopsis-Brassica comparative genome analysis for synteny-based identification of gene-linked SSR markers that can potentially be used in marker-assisted selection for an important trait in oilseed rape.

Risk for severe hypoglycaemia with unawareness in GH-deficient patients during the insulin tolerance test

OBJECTIVE

The insulin tolerance test (ITT) has been suggested as the gold standard for diagnosing GH deficiency (GHD). The ITT is, however, potentially hazardous. Glucose monitoring during the ITT varies between centres and there is surprisingly little information on the actual level of blood glucose nadir and the duration of hypoglycaemia in patients undergoing the ITT. The aim of the present study was to closely monitor the blood glucose level and to register the presence of symptoms and signs of hypoglycaemia during the ITT.

DESIGN AND PATIENTS

Sixteen patients (seven women), aged 22-59 years were consecutively recruited for an ITT, and showed GHD (peak GH < 3 microg/l).

RESULTS

In five (31%) of the patients unawareness of hypoglycaemia was recorded, the median nadir blood glucose level was 1.4 mmol/l (range 1.1-1.9) and the duration of blood glucose < 2.2 mmol/l was 25 min (range 20-33). The remaining 11 patients were symptomatic, and tiredness (n=6) and dizziness (n=3) were the most frequent symptoms. In these symptomatic patients the median nadir blood glucose level was 1.3 mmol/l (range 1.0-1.6) and the duration of blood glucose < 2.2 mmol/l was 25 min (range 15-30).

CONCLUSIONS

In patients with GHD subjected to the ITT, symptoms of hypoglycaemia were scarce and a third showed unawareness. Close blood glucose monitoring is recommended at the ITT as low nadir blood glucose levels and long duration of hypoglycaemia may be present irrespective of symptoms of hypoglycaemia. Recommendations for intervention with intravenous glucose, at unacceptable low blood glucose levels or at prolonged hypoglycaemia, are warranted.

Palliative second-line treatment with weekly high-dose 5-fluorouracil as 24-hour infusion and folinic acid (AIO) plus oxaliplatin after pre-treatment with the AIO-regimen in colorectal cancer (CRC)

BACKGROUND AND AIMS

The aim of this work was to evaluate the efficacy and safety of second-line treatment with weekly high-dose 5-Fluorouracil (5-FU) as a 24-hour infusion (24-h inf.) and folinic acid (FA) (AIO-regimen) plus Oxaliplatin (L-OHP) after pre-treatment with the AIO regimen, focusing in particular on the efficacy of palliative first- and second-line treatment in colorectal carcinoma (CRC).

PATIENTS AND METHODS

Patients with non-resectable distant CRC metastases were enrolled in a prospective phase II study for palliative second-line treatment after previous palliative first-line treatment in accordance with the AIO regimen. On an outpatient basis, the patients received a treatment regimen comprising biweekly 85 mg/m2 L-OHP in the form of a 2-hour intravenous (i.v.) infusion and 500 mg/m2 FA as a 1 to 2-hour i.v. infusion, followed by 2,600 mg/m2 5-FU administered as a 24-h inf. i.v. once weekly. A single treatment cycle comprised 6 weekly infusions followed by 2 weeks of rest.

RESULTS

During second-line treatment, a total of 26 patients received 340 chemotherapy applications. As the main symptom of toxicity, diarrhoea (NCI-CTC toxicity grade 3+4) presented in 5 patients (19%; 95% CI: 4-34), followed by nausea (CTC grade 3) in one patient (4%; 95% CI: 0-11). Twenty-three patients were evaluable for treatment response. The remission data can be summarised as follows: Complete remission (CR): n=1 (4%; 95% CI: 0-13); partial remission (PR): n=3 (13%; 95% CI: 0-27); stable disease (SD): n=11 (48%; 95% CI: 27-68) and progressive disease (PD): n=8 (35%; 95% CI: 15-54). The median progression-free survival (PFS) rate (n=26) was 3.3 months (range 0-11.5), the median survival time counted from the start of second-line treatment (n=26) 11.6 months (range 2.1-33.0) and the median survival time counted from the start of first-line treatment (n=26) 19.9 months (range 7.7-49.8).

CONCLUSION

Palliative second-line treatment according to the AIO regimen plus L-OHP is feasible in an outpatient setting and well tolerated by the patients. Tumour control (CR + PR + SD) was achieved in 65% of the patients, the median survival time being 11.6 months. The AIO regimen followed by the 'AIO regimen plus L-OHP' therapy sequence led to a promising median survival time of 19.9 months (range 7.7-49.8).

European Study Group for Pancreatic Cancer-1 interim results: a European randomized study to assess the roles of adjuvant chemotherapy and chemoradiation in resectable pancreatic cancer

Background

Pancreatic cancer affects 8–12 per 100 000 population per year in Europe. Following resection, the long-term survival rate is only 10–15 per cent and the role of adjuvant treatment is uncertain. The aims of the study were to answer two questions: (1) whether there is a role for chemoradiation (40 Gy and 5-fluorouracil (5-FU), and (2) whether there is a role for chemotherapy (5-FU–folinic acid (FA)) weekly).

Methods

A multicentre European prospective randomized controlled trial was organized by the European Study Group for Pancreatic Cancer (ESPAC). A 2 × 2 factorial design was used, asking both questions of the same patient, and a pragmatic design asking only one of the two questions of each patient. The data were reviewed at regular intervals by the Independent Data and Safety Monitoring Committee (IDSMC).

Results

Some 531 patients with pancreatic ductal adenocarcinoma were randomized from 80 clinicians in 11 countries. Randomization was stratified by resection margin involvement; 82 per cent of patients were negative. Some 239 patients (45 per cent) are alive to date, at a median follow-up of 9 (interquartile range 1–24) months. Preliminary results show no evidence of a benefit for chemoradiation treatment (median survival 14 months with chemoradiation versus 15·7 months without; P = 0·24). There is some evidence of a survival benefit for patients having chemotherapy (median survival 19·5 months versus 13·5 months with no chemotherapy; P = 0·003). The effect is reduced when taking into account whether patients received radiotherapy (P = 0·01), indicating that radiotherapy may reduce the overall benefit of the chemotherapy. The IDSMC recommended closing recruitment to the chemoradiotherapy arm.

Conclusion

There is no role for adjuvant chemoradiotherapy in pancreatic cancer, but there may be a role for chemotherapy. ESPAC-3 is now randomizing between (1) surgery alone, (2) 5FU–FA and (3) gemcitabine.

Low individualized growth hormone (GH) dose increased renal and cardiac growth in young adults with childhood onset GH deficiency

OBJECTIVE

In childhood onset GH deficiency (GHD) a reduction in left ventricular mass (LV-mass) and impairment of systolic function as well an impairment in glomerular filtration rate (GFR) has been shown. The aim of the present study was to assess if a low GH dose resulted in an improvement in morphological and functional parameters of these organs.

DESIGN AND PATIENTS

Eleven patients with childhood onset GHD were investigated before and after 10 months of GH treatment at a dose of 1.5 IU/day (range 1-2), corresponding to 0.02 IU/kg/day or 7 microg/ kg/day. The GH dose resulted in a serum IGF-I level in the normal range in all but one patient.

MEASUREMENTS

Doppler echocardiography of the heart and ultrasound examination of the kidneys was performed. Glomerular filtration rate (GFR) was estimated with iohexol clearance and urinary proteinuria was measured with 24-h urinary samples collected for analyses of albumin, alpha-1-microglobulin, IgG and albumin/creatinine clearance ratio. Body composition was measured by bioelectric impedance analysis.

RESULTS

L V-mass index increased significantly after GH treatment (P = 0.04), and there was a clear trend for a positive correlation between the increase in serum IGF-I and the increase in LV-mass index, although it did not reach significance (r= 0.57, P = 0.07). GH treatment did not increase cardiac fractional shortening. Kidney length increased significantly (P = 0.02) with an average increase of 1 cm (range - 0.5-1.5 cm). No significant changes in median GFR or serum creatinine were recorded. Three patients with subnormal GFR before GH treatment normalized after 10 months of treatment. Urine analysis showed no abnormalities before or after GH treatment. A significant decrease in percentage fat mass was recorded (P = 0.03).

CONCLUSION

A low individualized GH dose to adults with childhood onset GHD resulted in an increase in LV-mass index and kidney length. Re-establishing GH treatment with a low dose in this patient group can lead to a further somatic maturation of these organs, probably not accomplished previously.

Adjuvant chemoradiotherapy and chemotherapy in resectable pancreatic cancer: a randomised controlled trial

BACKGROUND

The role of adjuvant treatment in pancreatic cancer remains uncertain. The European Study Group for Pancreatic Cancer (ESPAC) assessed the roles of chemoradiotherapy and chemotherapy in a randomised study.

METHODS

After resection, patients were randomly assigned to adjuvant chemoradiotherapy (20 Gy in ten daily fractions over 2 weeks with 500 mg/m(2) fluorouracil intravenously on days 1-3, repeated after 2 weeks) or chemotherapy (intravenous fluorouracil 425 mg/m(2) and folinic acid 20 mg/m(2) daily for 5 days, monthly for 6 months). Clinicians could randomise patients into a two-by-two factorial design (observation, chemoradiotherapy alone, chemotherapy alone, or both) or into one of the main treatment comparisons (chemoradiotherapy versus no chemoradiotherapy or chemotherapy versus no chemotherapy). The primary endpoint was death, and all analyses were by intention to treat. Findings 541 eligible patients with pancreatic ductal adenocarcinoma were randomised: 285 in the two-by-two factorial design (70 chemoradiotherapy, 74 chemotherapy, 72 both, 69 observation); a further 68 patients were randomly assigned chemoradiotherapy or no chemoradiotherapy and 188 chemotherapy or no chemotherapy. Median follow-up of the 227 (42%) patients still alive was 10 months (range 0-62). Overall results showed no benefit for adjuvant chemoradiotherapy (median survival 15.5 months in 175 patients with chemoradiotherapy vs 16.1 months in 178 patients without; hazard ratio 1.18 [95% CI 0.90-1.55], p=0.24). There was evidence of a survival benefit for adjuvant chemotherapy (median survival 19.7 months in 238 patients with chemotherapy vs 14.0 months in 235 patients without; hazard ratio 0.66 [0.52-0.83], p=0.0005). Interpretation This study showed no survival benefit for adjuvant chemoradiotherapy but revealed a potential benefit for adjuvant chemotherapy, justifying further randomised controlled trials of adjuvant chemotherapy in pancreatic cancer.

Effect of condoms on reducing the transmission of herpes simplex virus type 2 from men to women

CONTEXT

Herpes simplex virus type 2 (HSV-2) is one of the most common sexually transmitted infections in the United States. No prospective study has shown the ability of condoms to reduce transmission of HSV-2.

OBJECTIVE

To evaluate risk factors for HSV-2 acquisition and efficacy of condoms in prevention of HSV-2 transmission.

DESIGN

Analysis of data from a randomized, double-blind, placebo-controlled trial conducted December 13, 1993, to June 28, 1996, of an ineffective candidate HSV-2 vaccine with 18 months of follow-up.

SETTING

Eighteen clinical trial centers in the United States.

PARTICIPANTS

A total of 528 monogamous couples discordant for HSV-2 infection, including an HSV-2-susceptible population of 261 men and 267 women.

MAIN OUTCOME MEASURE

Acquisition of HSV-2 infection by susceptible partners, compared with those remaining free of HSV-2 with regard to demographic characteristics, sexual activity, and condom use.

RESULTS

Twenty-six women (9.7%) vs 5 men (1.9%) acquired HSV-2, for a rate per 10 000 sex acts (episodes of sexual intercourse) of 8.9 vs 1.5, respectively (P<.001). In multivariable analysis, younger age (adjusted hazard ratio [HR] per 5 years, 1.57; 95% confidence interval [CI], 1.22-2.04), seropositivity for HSV-1 and HSV-2 vs HSV-2 alone in the source partner (adjusted HR, 2.34; 95% CI, 1.14-4.82), and more frequent sexual activity (adjusted HR per additional sex act per week, 1.10; 95% CI, 1.01-1.19) were associated with higher risk of HSV-2 acquisition. Condom use during more than 25% of sex acts was associated with protection against HSV-2 acquisition for women (adjusted HR, 0.085; 95% CI, 0.01-0.67) but not for men (adjusted HR, 2.02; 95% CI, 0.32-12.50). Risk of HSV-2 transmission declined from 8.5 per 100 person-years in the initial 150-day interval to 0.9 per 100 person-years in the final 150-day interval (P =.002 for trend), concurrent with a decrease in sexual activity and proportion of sex acts occurring when the source partner had genital lesions.

CONCLUSIONS

Condom use offers significant protection against HSV-2 infection in susceptible women. Changes in sexual behavior, correlated with counseling about avoiding sex when a partner has lesions, were associated with reduction in HSV-2 acquisition over time. These data suggest that identification of discordant couples can reduce transmission of HSV-2, especially for heterosexual couples in which the male partner has HSV-2 infection.

Formation of the single-layer beta-sheet of Borrelia burgdorferi OspA in the absence of the C-terminal capping globular domain

Borrelia outer surface protein A (OspA) contains a unique single-layer beta-sheet that connects N and C-terminal globular domains. This single-layer beta-sheet segment (beta-strands 8-10) is highly stable in solution, although it is exposed to the solvent on both faces of the sheet and thus it does not contain a hydrophobic core. Here, we tested whether interactions with the C-terminal domain are essential for the formation of the single-layer beta-sheet. We characterized the solution structure, dynamics and stability of an OspA fragment corresponding to beta-strands 1-12 (termed OspA[27-163]), which lacks a majority of the C-terminal globular domain. Analyses of NMR chemical shifts and backbone nuclear Overhauser effect (NOE) connectivities showed that OspA[27-163] is folded except the 12th and final beta-strand. (1)H-(15)N heteronuclear NOE measurements and amide H-(2)H exchange revealed that the single-layer beta-sheet in this fragment is more flexible than the corresponding region in full-length OspA. Thermal-denaturation experiments using differential scanning calorimetry and NMR spectroscopy revealed that the N-terminal globular domain in the fragment has a conformational stability similar to that of the same region in the full-length protein, and that the single-layer beta-sheet region also has a modest thermal stability. These results demonstrate that the unique single-layer beta-sheet retains its conformation in the absence of its interactions with the C-terminal domain. This fragment is significantly smaller than the full-length OspA, and thus it is expected to facilitate studies of the folding mechanism of this unusual beta-sheet structure.

Design of single-layer beta-sheets without a hydrophobic core

The hydrophobic effect is the main thermodynamic driving force in the folding of water-soluble proteins. Exclusion of nonpolar moieties from aqueous solvent results in the formation of a hydrophobic core in a protein, which has been generally considered essential for specifying and stabilizing the folded structures of proteins. Outer surface protein A (OspA) from Borrelia burgdorferi contains a three-stranded beta-sheet segment which connects two globular domains. Although this single-layer beta-sheet segment is exposed to solvent on both faces and thus does not contain a hydrophobic core, the segment has a high conformational stability. Here we report the engineering of OspA variants that contain larger single-layer beta-sheets (comprising five and seven beta-strands) by duplicating a beta-hairpin unit within the beta-sheet. Nuclear magnetic resonance and small-angle X-ray scattering analyses reveal that these extended single-layer beta-sheets are formed as designed, and amide hydrogen-deuterium exchange and chemical denaturation show that they are stable. Thus, interactions within the beta-hairpin unit and those between adjacent units, which do not involve the formation of a hydrophobic core, are sufficient to specify and stabilize the single-layer beta-sheet structure. Our results provide an expanded view of protein folding, misfolding and design.

Bacterial complications of strongyloidiasis: Streptococcus bovis meningitis

We report the case of a 64-year-old veteran who had Streptococcus bovis meningitis as a result of a long latent Strongyloides infection that became acute when he was treated with prednisone. We reviewed 38 reported cases of serious bacterial infections associated with strongyloidiasis. Patients most frequently had nonspecific gastrointestinal symptoms. Of these 38 patients, 21 (55%) had meningitis, and 28 (73%) had bacteremia that was polymicrobial in 3 cases (8%). Other sites of infection included lung, bone marrow, ascites, mitral valve, and lymph node. Most infections were due to enteric gram-negative bacteria. There is one previously reported case of S bovis meningitis. Thirty-four of the patients (89%) were immunosuppressed; 21 of these (55%) were taking pharmacologic doses of adrenal corticosteroids. Thirty-three of the 38 (87%) patients died. Patients with enteric bacterial infection without an obvious cause should be tested for the presence of strongyloidiasis.

ESPAC-1 trial progress report: the European randomized adjuvant study comparing radiochemotherapy, 6 months chemotherapy and combination therapy versus observation in pancreatic cancer

At the joint International Association of Pancreatology and European Pancreatic Club meeting at King's College, London (July 9-12, 1997), a satellite meeting of the European Study Group for Pancreatic Cancer (ESPAC) met to discuss the progress of the ESPAC-1 trial. This study will address which, if any, of the following adjuvant treatments are of benefit in patients with resectable pancreatic cancer: radiotherapy (40 Gy with 5-fluorouracil as a sensitising agent); 6 months chemotherapy (5-fluorouracil and folinic acid), or a combination of these treatments. The study, which commenced in 1994, had already recruited 348 patients into the 3 treatment arms and 1 control arm of the study by May 31, 1997. This is the largest study of its kind in pancreatic cancer and should definitively address the question of the role of conventional methods of adjuvant treatment in pancreatic cancer.

Postictal neurogenic pulmonary edema: experience from an ECT model

Neurogenic pulmonary edema (NPE) is thought to rarely occur after seizures. Paradoxically, NPE is frequently found (>80%) at autopsy in epileptic patients who die unexpectedly. The reason for the discrepancy between the frequency of NPE found at autopsy and that after uncomplicated seizures is unclear. The literature suggests that subclinical NPE occurs rarely after uncomplicated seizures and resolves within a few hours, but is undetected because of infrequent use of routine chest radiographs early after a seizure occurs. This pilot study examined the frequency of subclinical, radiographically confirmed NPE after electroconvulsive therapy (ECT)-induced seizures. If shown to occur, ECT-induced subclinical NPE would provide an easily reproducible model to study NPE after seizures in patients with epilepsy. Given that sudden unexplained death syndrome accounts for approximately 10% of the deaths in patients with epilepsy, an easily reproducible model for NPE would have heuristic value. We examined 12 patients undergoing ECT for depression with chest radiographs before and after ECT. In this group, only 1 of the 12 patients had subclinical NPE in their post-ECT radiograph. We conclude that subclinical NPE does not significantly occur after seizures in patients undergoing ECT and therefore, would not serve as an application for research.

Progress report. A randomized multicenter European study comparing adjuvant radiotherapy, 6-mo chemotherapy, and combination therapy vs no-adjuvant treatment in resectable pancreatic cancer (ESPAC-1)

CONCLUSION

The ESPAC-1 trial is the largest study of its kind in pancreatic cancer and should definitively address the question of the role of conventional methods of adjuvant treatment in pancreatic cancer.

BACKGROUND

At the joint International Association of Pancreatology and the European Pancreatic Club meeting in Mannheim, Germany (June 12-15, 1996) a satellite meeting of the European Study Group for Pancreatic Cancer (ESPAC) met to discuss the progress of the ESPAC-1 trial.

METHODS

A randomized multicenter study to address which, if any, of the following adjuvant treatments are of benefit in patients with resectable pancreatic cancer: radiotherapy (40 Gy with 5-FU as a sensitizing agent), 6 mo of chemotherapy (5-FU and folinic acid), or a combination of these treatments.

RESULTS

From February 1994 to June 1996 (the time of the Mannheim meeting) 221 patients so far have been recruited into the three treatment arms and one control arm.

[Clinical studies of the incidence of pulmonary and extrapulmonary tuberculosis]

On the whole 797 patients (mean age 49.5 +/- 18.6 years) with tuberculosis who were hospitalized during 1987 and the first half of the year 1994 were investigated. 148 (18.6%) of these patients were foreigners. Regarding the age, the patients of German origin were mostly above 40 years (70.5%). Within the group of foreigners, 61.5% were below 40 years. 83.3% of the patients suffered from pulmonary and 11.4% from extrapulmonary and 11.4% from extrapulmonary tuberculosis. 5.3% of these patients had both manifestations. The tuberculin tine test was positive in 95.7% and negative in 4.3%. In 63.9% of all patients the tuberculosis was localized in the upper lobe of the lung. The tuberculosis was established bacteriologically in 56.0% and histologically in 16.5%. Both methods were applied in 13.6%. The tuberculosis was deteriorated by chronic alcoholism. Malignant diseases were recorded in 17 (2.1%) of the patients. 22 (2.8%) died during their stay at the hospital.

Correlation of serum ibuprofen concentration with clinical signs of toxicity in three canine exposures

The clinical signs and serum concentrations of ibuprofen are reported for 3 canine exposures. No adverse clinical signs or abnormal laboratory parameters were observed when serum ibuprofen concentrations were less than 31 micrograms/mL. Melena and 38 mg blood urea nitrogen/dL (normal 7-26 mg/dL) were present in an animal with a serum ibuprofen of 138 micrograms/mL.

Rapid antimicrobial susceptibility testing of gram-negative bacilli using Baxter MicroScan rapid fluorogenic panels and autoSCAN-W/A

The MicroScan Rapid Neg MIC/Combo panels and autoSCAN-W/A (Walk Away) system utilize automated fluorescence technology for rapid antimicrobial susceptibility testing of Gram-negative bacilli. In a three site clinical study eleven antimicrobial agents were evaluated by comparing results obtained with 741 clinical isolates, using rapid fluorogenic expanded dilution MIC panels and corresponding frozen microdilution reference panels determined visually. Results for 31%, 40%, 12% and 9% of the isolates were available within 3.5, 4.5, 5.5 and 7.0 hours respectively. Results for 7.3% were not available within that time period. For the seven drugs analyzed using a Minimum Inhibitory Concentration range of dilutions, overall agreement (+/- 1 dilution) was 94%, with 1.5% very major, 0.9% major and 2.5% minor errors. For the four drugs analyzed using a Breakpoint range of dilutions, overall agreement (+/- 1 dilution) was 97%, with two percent very major, and one percent major errors. The MicroScan Rapid Neg MIC system is an accurate and rapid method for same day determination of susceptibility of Gram-negative bacilli.