Spin-lattice relaxation time in water/graphene-oxide dispersion.

We present the results of the calculations of the spin-lattice relaxation time of water in contact with graphene oxide by means of all-atom molecular dynamics simulations. We fully characterized the water-graphene oxide interaction through the calculation of the relaxation properties of bulk water and of the contact angle as a function of graphene oxide oxidation state and comparing them with the available experimental data. We then extended the calculation to investigate how graphene oxide alters the dynamical and relaxation properties of water in different conditions and concentrations. We show that, despite the diamagnetic nature of the graphene oxide, the confining effects of the bilayers strongly affect the longitudinal relaxation properties of interfacial water, which presents a reduced dynamics due to hydrogen bonds with oxygen groups on graphene oxide. This property makes graphene oxide an interesting platform to investigate water dynamics in confined geometries and an alternative contrast-agent for magnetic resonance imaging applications, especially in view of the possibility to functionalize graphene oxide from theranostic perspectives.

Hepatocellular liver injury in hospitalized patients affected by COVID-19: Presence of different risk factors at different time points.

BACKGROUND: Prevalence and clinical impact of increased liver function tests in patients affected by Coronavirus disease 2019 (COVID-19) is controversial. AIMS: This observational study evaluates the prevalence of transaminases elevation in hospitalized patients affected by COVID-19 and investigates the presence of factors associated with hepatocellular injury and with mortality. METHODS: Data of 292 adult patients with confirmed COVID-19 admitted to the Ente Ospedaliero Cantonale (Switzerland) were retrospectively analyzed. RESULTS: Transaminases were increased in about one-third of patients on hospital admission and two-thirds of patients during the hospital stay. On hospital admission, transaminases were more commonly elevated in younger patients, who also reported elevated C reactive protein and a higher degree of respiratory failure. Independent factors associated with abnormal transaminases during hospitalization were drugs, in particular paracetamol (OR=2.67; 95% CI=1.38-5.18; p = 0.004) and remdesivir (OR=5.16; 95% CI=1.10-24.26; p = 0.04). Mortality was independently associated to age (OR = 1.09; 95% CI=1.05-1.13; p<0.001), admission to intensive care unit (OR=5.22; 95% CI=2.28-11.90; p<0.001) and alkaline phosphatase peak (OR=1.01; 95% CI=1.00- 1.01; p = 0.01). CONCLUSIONS: On hospital admission, factors associated with liver damage were linked to demographic and clinical characteristics (age, inflammation and hypoxia) while, during hospitalization, drug treatment was related to development and progression of hepatocellular damage. Mortality was associated with alkaline phosphate peak value.

Portal vein thrombosis: an overview of current treatment options.

Portal vein thrombosis (PVT) is a splanchnic vascular disorder characterised by a recent or chronic thrombotic occlusion of the portal venous system. Its aetiology is miscellaneous, and its management is demanding since PVT can play a critical role as far as morbidity and mortality are concerned. Indeed, PVT can develop as a complication of portal hypertension (PH), in association or not with advanced chronic liver disease, and aggravate its clinical consequences such as variceal bleeding and ascites. Furthermore, a diagnosis of PVT in a non-cirrhotic context can potentially reveal a previously unknown hypercoagulable condition, requiring further diagnostic steps and specific treatment in addition to anticoagulation. In addition to established therapeutic approaches, new strategies, including newer pharmacological treatments and interdisciplinary invasive procedures, gain more attention and have been increasingly introduced into clinical practice. This review aims at discussing the current knowledge in terms of treatment options for PVT.

Variation in collagenase Clostridium histolyticum practice patterns: a Survey of ISSM Members.

Collagenase clostridium histolyticum (CCH, Xiaflex, Xiapex) is the only FDA-approved medication for treatment of Peyronie's disease. It is unclear how practitioners actually use CCH in their own practices. The objectives of the study were: (1) to identify variability in practice patterns for CCH among practitioners, (2) to assess adherence to the package insert instructions, and (3) to evaluate whether provider satisfaction was associated with adherence to instructions. A 30-question online survey was distributed to 1270 members of the International Society for Sexual Medicine (ISSM) from the EU, USA, Canada and Australia. Of the 30 questions, 10 survey questions had only one response consistent with the CCH package insert recommendations. An "adherence" score was calculated for each survey participant depending on how many of these questions were answered correctly. The average adherence scores of various groups were compared using a student's t-test. A chi-squared test was used to determine association between categorical variables. Of 202 total responses, 132 practitioners reported using CCH out of 1270 ISSM members from countries where CCH is available (10.4% response rate). Practitioners from outside the USA were more likely to be satisfied with CCH (p = 0.006), and more experienced users (>20 uses) were more likely to be satisfied than less experienced users (<10 uses) (p = 0.046). Satisfied users of CCH did not have significantly different adherence scores than non-satisfied users. Even though 67% of practitioners believed they followed the package insert guidelines, only 11% adhered to all the recommendations evaluated by the survey. Treatment adherence to package insert guidelines does not appear to be associated with provider satisfaction. We believe there is utility in seeing a snapshot of these practice patterns so practitioners may feel more comfortable adapting their own practice in light of newer data supporting alternative administration methods.

Relevance of chronic hepatitis E in liver transplant recipients: a real-life setting.

The chronic course of hepatitis E virus (HEV) infections in orthotopic liver transplant (OLT) recipients has been described previously, but prospectively collected data are rare. We aimed to study the role of chronic hepatitis E in OLT in a real-life setting. Therefore, 287 adult OLT recipients (169 male [59%], median age 56 years) were prospectively tested by HEV polymerase chain reaction assay (lower level of detection = 10 IU/mL), irrespective of their level of liver enzymes. In 4 patients (1.4%), chronic HEV infection was diagnosed. All 4 patients were male, and their age (median 48.5 years), the time since transplantation (median 45.5 months), and bilirubin level (median 0.6 mg/dL) did not differ significantly from the total cohort. However, alanine transaminase and aspartame transaminase levels were significantly higher in HEV-infected patients (75-646 U/L, median 216 U/L and 68-317 U/L, median 108 U/L) than in non-infected patients (6-617 U/L, median 41 and 6-355 U/L, median 36; P = 0.004 and 0.040, Mann-Whitney test). In 3 patients, liver biopsy was performed and revealed signs of inflammation and chronic liver disease, as enlarged densely infiltrated portal tracts with mild-to-moderate interface hepatitis. All infected patients were treated with ribavirin with the starting dose adjusted to renal function (400-800 mg/day). In 2 patients, dose reduction was necessary. Transaminases normalized in all 4 patients, and all patients cleared their infection within 3 months of ribavirin treatment. However, 1 patient experienced viral relapse 12 weeks after discontinuation. Ribavirin medication was re-started and viral clearance occurred within 8 weeks and persisted. Sequence analysis of the HEV genome of this patient revealed that he was infected with an HEV variant, which recently has been shown to have a reduced response to ribavirin in cell culture. The risk of chronic HEV infections in OLT recipients in low-endemic countries should not be overestimated. No case of chronic hepatitis E was observed in patients with normal liver enzymes, indicating that general screening of all OLT recipients is not necessary. However, if chronic hepatitis E develops, it can be treated efficiently with ribavirin.

Antagonism of histamine H4 receptors exacerbates clinical and pathological signs of experimental autoimmune encephalomyelitis.

BACKGROUND AND PURPOSE: The histamine H4 receptor has a primary role in inflammatory functions, making it an attractive target for the treatment of asthma and refractory inflammation. These observations suggested a facilitating action on autoimmune diseases. Here we have assessed the role of H4 receptors in experimental autoimmune encephalomyelitis (EAE) a model of multiple sclerosis (MS). EXPERIMENTAL APPROACH: We induced EAE with myelin oligodendrocyte glycoprotein (MOG35-55 ) in C57BL/6 female mice as a model of MS. The histamine H4 receptor antagonist 5-chloro-2-[(4-methylpiperazin-1-yl)carbonyl]-1H-indole (JNJ7777120) was injected i.p. daily starting at day 10 post-immunization (D10 p.i.). Disease severity was monitored by clinical and histopathological evaluation of inflammatory cells infiltrating into the spinal cord, anti-MOG35-55 antibody production, assay of T-cell proliferation by [(3) H]-thymidine incorporation, mononucleate cell phenotype by flow cytometry, cytokine production by elisa assay and transcription factor quantification of mRNA expression. KEY RESULTS: Treatment with JNJ7777120 exacerbated EAE, increased inflammation and demyelination in the spinal cord of EAE mice and increased IFN-γ expression in lymph nodes, whereas it suppressed IL-4 and IL-10, and augmented expression of the transcription factors Tbet, FOXP3 and IL-17 mRNA in lymphocytes. JNJ7777120 did not affect proliferation of anti-MOG35-55 T-cells, anti-MOG35-55 antibody production or mononucleate cell phenotype. CONCLUSIONS AND IMPLICATIONS: H4 receptor blockade was detrimental in EAE. Given the interest in the development of H4 receptor antagonists as anti-inflammatory compounds, it is important to understand the role of H4 receptors in immune diseases to anticipate clinical benefits and also predict possible detrimental effects.

Assessment of baseline characteristics and risk factors among Emergency Department patients presenting with recent onset atrial fibrillation: a retrospective cohort study.

BACKGROUND: The Cardioversion of Atrial Fibrillation in Emergency (CAFE) study was an observational, retrospective, multicenter study focusing on patients with recent onset atrial fibrillation (AF) seen in six different Emergency Departments (ED) of Rome, Italy. AIM: The aim of this study was to present the baseline characteristics and risk factors of the patients enrolled to the CAFE study. MATERIALS AND METHODS: We retrospectively reviewed 3085 eligible patients diagnosed with recent onset AF in any of the EDs between January 2008 and December 2009. Inclusion criteria required documented ICD-9 primary discharge/admission diagnosis of AF in the ED and stable hemodynamic conditions at presentation (systolic blood pressure > 90 mmHg). Exclusion criteria were permanent AF or an ongoing acute coronary syndrome. RESULTS: Median age was 71 years (interquartile ranges, 62-78 years) and 50.8% were men. Palpitations was the most common symptom at ED presentation and was present in 73.5% of the study subjects. Hypertension was the most prevalent comorbidity, affecting 59.3% of the patients evaluated, and the presence of previous episode(s) of AF was also common (52.3%). Regarding home treatment, the drugs most prescribed were antiplatelets (31.2%) and diuretics (25.2%). A CHADS2 score of 0 was found in 814 patients (26.4%), while a CHADS2 score of 1 was reported in 1114 patients (36.1%). Finally, a CHADS2 score ≥ 2 was reported in 1157 patients (37.5%). CONCLUSIONS: The present study represents an important snapshot of demographics, comorbidities, risk factors and anticoagulation management about patients with recent onset AF. Disparities were noted in anticoagulation management, suggesting that this is still a main problem among patients with AF.

Caracterização molecular do vírus da raiva isolado de Desmodus rotundus capturados no Estado do Rio de Janeiro / Molecular characterization of rabies virus isolated from Desmodus rotundus captured in Rio de Janeiro State

Caracterizou-se filogeneticamente o vírus da raiva, isolado de morcegos hematógafos (Demodus rotundus). Cento e noventa e nove D. rotundus foram capturados em cinco abrigos, no Norte e Noroeste do Estado do Rio de Janeiro e sul do Espírito Santo. Sete deles foram positivos para a raiva. Amostras desses vírus foram sequenciadas e comparadas com sequências provenientes de diversos estados brasileiros. As sequências de vírus da raiva isoladas, na região norte do Estado do Rio de Janeiro, mostraram características que as distinguem de amostras de vírus isoladas em outras regiões do país, no entanto foram idênticas às isoladas de bovinos no noroeste do Rio de Janeiro.

Rabies samples isolated from vampire bats captured in the Rio de Janeiro State were phylogenetically analyzed. One hundred and ninety nine vampire bats were captured from five shelters from North and Northwest of Rio de Janeiro and South of Espírito Santo States. Seven of them were positive for rabies. Theses samples were sequenced and compared with rabies virus sequences from several Brazilian states. The sequences of rabies virus, isolated in the present work, from North of Rio de Janeiro State, showed characteristics that differ of the sequences isolated from bats from other Brazilian regions. However, they were identical to samples isolated from cattle in Northwest of Rio de Janeiro state.

Cardiac autonomic regulation after lung exposure to carbon nanotubes.

The ultrafine (UF) component of airborne pollution may impair cardiovascular autonomic control, a high-risk condition for cardiovascular adverse events. Since engineered nanoparticles, such as single-walled carbon nanotubes (SWCNTs) share physicochemical properties with UF, they might have similar adverse effects. Aim of the study was to evaluate arterial baroreflex function (BRF) at baseline, 24 h after the first instillation, immediately before the second one, and 2 weeks later, in adult Wystar-Kyoto conscious rats undergoing two intratracheal instillations of SWCNT (eight rats) or phosphate buffer saline (PBS) (five rats) at 2-week interval. During each session, 30-min continuous recording of arterial pressure and pulse interval was performed by a telemetered catheter implanted in the abdominal aorta of the rats. BRF was studied by the sequence technique. SWCNTs dispersed in PBS (1 mg/ml) were administered immediately after sonication (1 microg/g body weight). A significant decrease in the number of baroreflex sequences (from 498 +/- 27.1 at baseline to 287 +/- 40.2 at the recording performed after 4 weeks; P < 0.05) was observed in SWCNT-instilled rats, whereas no significant change was detected in controls. These data suggest that SWCNTs may alter the BRF, thus affecting the autonomic cardiovascular control regulation.

Helicobacter pylori interference with micronutrients and orally administered drugs: a new mechanism explaining its role in extragastric disorders.

There is an increasing evidence that Helicobacter pylori may interfere with gastrointestinal metabolism of micronutrients and drugs such as iron, cobalamin, thyroxine and levodopa, with relevant clinical effects. In this review we examine the strength of the causal association and the plausible pathophysiologic mechanisms underlying these adverse effects.

Maternal and fetal hemodynamic effects induced by nitric oxide donors and plasma volume expansion in pregnancies with gestational hypertension complicated by intrauterine growth restriction with absent end-diastolic flow in the umbilical artery.

OBJECTIVE: To evaluate the effect of plasma volume expansion (PVE) and nitric oxide (NO) donors, in addition to antihypertensive therapy for gestational hypertensive pregnancies complicated by intrauterine growth restriction (IUGR) with absent end-diastolic flow (AEDF) in the umbilical artery (UA). METHODS: This was a case-control study into which 32 gestational hypertensive pregnancies with IUGR and AEDF were enrolled. Sixteen of these were treated with antihypertensive drugs, NO donors and PVE (Group A), and 16, matched for maternal age, gestational age and fetal conditions, were treated with antihypertensive drugs only (Group B). All patients underwent fetal and uteroplacental assessment and maternal echocardiography to evaluate total vascular resistance (TVR) and cardiac output before and 5-14 days after initiation of treatment. RESULTS: After 5-14 days of treatment, the maternal TVR in Group A fell from 2170 +/- 248 to 1377 +/- 110 dynes.s.cm(-5) (P < 0.01), and that in Group B fell from 2090 +/- 260 to 1824 +/- 126 dynes.s.cm(-5) (P < 0.01), with the reduction being greater in Group A than in Group B (P < 0.01). There was a significant increase in cardiac output in Group A after 5-14 days of treatment vs. baseline (6.19 +/- 0.77 vs. 4.32 +/- 0.66, P < 0.001), and, after treatment, cardiac output was significantly greater in Group A than it was in Group B (6.19 +/- 0.77 vs. 4.70 +/- 0.44, P < 0.001). Reappearance of end-diastolic flow in the UA occurred in 14/16 patients in Group A but in no patients in Group B (87.5% vs. 0%, P < 0.05). The interval between detection of UA-AEDF and delivery was 28 +/- 16 days in Group A and 11 +/- 6 days in Group B (P < 0.05). CONCLUSION: Administration of NO donors and PVE in gestational hypertensive pregnancies affected by IUGR and UA-AEDF appears to improve both maternal and fetal hemodynamics, inducing prolongation of gestation.

Recurrent myocardial ischaemia during combination antiviral therapy in a patient with chronic hepatitis C and normal aminotransferase levels.

A 63-year-old man with chronic hepatitis C and persistently normal alanine aminotransferase levels was treated with peginterferon alpha-2a (180 microg weekly) and ribavirin (800 mg daily). Hepatitis C virus-ribonucleic acid was negative at week 4. After 12 weeks of therapy, haemoglobin levels had decreased by 3.5mg/dL, and he developed a syncope episode with electrocardiographic signs of myocardial ischaemia. Antiviral treatment was stopped and the ischaemia-like electrocardiographic changes resolved completely within 2 months. Eight months later, because of the previous rapid virological response and patient motivation, he was treated again with peginterferon and ribavirin. Baseline and weekly electrocardiographic recordings were obtained during treatment. At week 4 hepatitis C virus-ribonucleic acid was negative. At week 8, when the haemoglobin levels had decreased by 3.4 mg/dL, the patient developed the same ischaemia-like changes that occurred during the previous treatment. Antiviral therapy was stopped and the electrocardiographic ischaemia-like changes disappeared after 1 month. The patient neither had a history of previous cardiovascular diseases, nor evidence of current disease at myocardial scintigraphy. However, a coronary microvessel spasm, possibly related to drug-toxicity and/or anaemia could not be excluded. This case indicates the need of strict electrocardiographic monitoring in elderly patients undergoing treatment with peginterferon and ribavirin.

[Guidelines for the treatment of child spasticity using botulinum toxin]. / Guía terapéutica de la espasticidad infantil con toxina botulínica.

AIMS: The introduction of botulinum toxin has been a significant step forward in the treatment of spasticity in children and is now considered to be the preferred treatment in focal spasticity. With the aim of optimising this therapeutic resource, a group of Spanish neurologists and specialists in rehabilitation have drawn up these therapeutic guidelines based on the currently available evidence on its use and indications, and on their own experience. DEVELOPMENT: Spasticity in childhood is mainly caused by infantile cerebral palsy. Its natural history is not favourable due to the negative effect of growth and it should be treated before permanent deformities in bones and joints appear. Treatment with botulinum toxin diminishes hyperactivity and muscle tone, and allows the muscle to grow longitudinally, which prevents permanent contractions. The advantages of botulinum toxin are obvious (ease of use and dosing, long-lasting effects, reversibility in case of adverse responses, and so forth) and outnumber by far the few drawbacks it offers. Before it can be used patients, treatment goals and the muscle areas to be treated must all be selected correctly and, at the same time, a tailored rehabilitation scheme must also be developed. The growing body of experience suggests that its early administration is effective in preventing or reducing the severe complications of spasticity. CONCLUSIONS: Botulinum toxin type A is very effective in the treatment of spasticity. These guidelines offer the well-documented experience gained from its use and our knowledge about its indications, effects and safety in clinical practice.

[Interaction between carbon nanotubes and cardiovascular autonomic nervous system regulation: proposal of an animal model and preliminary findings]. / Interazione tra nanotubi di carbonio e controllo cardiovascolare del sistema nervoso autonomo: presentazione di un modello sperimentale animale e risultati preliminari.

BACKGROUND: Altered autonomic cardiovascular regulation (ACR) may mediate the association between single-wall carbon nanotubes (SWCNT) exposure and adverse cardiovascular events. MATERIAL AND METHODS: 400 mg of SWCNT in 400 ml of phosphate buffer saline (PBS) or 400 ml of PBS were randomly given to 7 Wystar-Kyoto rats (400 g body wt) previously implanted in abdominal aorta with a telemetry transmitter for recordings of arterial pressure signals. Recordings were performed at baseline, 24 hours and two weeks after intratracheal instillation. The beat-by-beat time series of systolic arterial pressure (SAP) and PR interval were analyzed to identify sequences of three or more consecutive beats in which SAP and PR changed in the same (baroreflex sequences) or in the opposite direction (nonbaroreflex sequences). The mean individual slope of the sequences was calculated and taken as a measure of the baroreflex (BRS) and nonbaroreflex sensitivity for that period. RESULTS: The 24 hour BRS response showed a 100% increase (from 4.6 to 9.2 msec/mmHg) in controls, whereas it was blunted in cases (from 5.1 to 6.1 msec/mmHg) (p < 0.05). CONCLUSIONS: Our study demonstrates that this rat model is suitable to study the ACR during exposure to SWCNT and suggests a blunted BRS response after SWCNT instillation.

Shift work increases the frequency of duodenal ulcer in H pylori infected workers.

AIM: To evaluate whether shift work is associated with an increased rate of peptic ulcer in H pylori infected workers. METHODS: During a two year period, consecutive dyspeptic workers underwent non-invasive evaluation of H pylori status by means of urea 13C breath test or stool testing. Those testing positive were included in the study and divided into two main categories: day-time workers and shift workers. An upper gastrointestinal endoscopy was performed in all workers, and biopsy specimens were taken from the stomach to confirm the presence of H pylori infection (culture and histology). RESULTS: A total of 247 day-time workers and 101 shift workers were included. The prevalence of duodenal ulcer was significantly higher in shift workers than in day-time workers (29 of 101 v 23 of 247; OR = 3.92, 95% CI 2.13 to 7.21), and persisted after multivariate analysis, taking into account possible confounding factors (OR = 3.96, 95% CI 2.10 to 7.47). CONCLUSION: Shift work increases the ulcerogenic potential of H pylori infection and should be considered a risk factor for duodenal ulcer in infected shift workers. Treatment of infection in this high risk group may improve the health of workers and may reduce the economic impact of peptic ulcer.

Maternal total vascular resistance and concentric geometry: a key to identify uncomplicated gestational hypertension.

OBJECTIVE: To evaluate the prognostic impact of elevated total vascular resistance (TVR) on the outcome of pregnancy in early mild gestational hypertension (EMGH). DESIGN: Prospective observational study. SETTING: Data collected from women with EMGH referred to the obstetrics outpatient clinic of Tor Vergata University from June 2003 to June 2005. POPULATION: A total of 268 women with EMGH (systolic and diastolic blood pressure [BP] 140-150 mmHg and 90-99 mmHg, respectively, without significant proteinuria). METHODS: Women had a maternal echocardiographic examination and BP examination within 24 hours of diagnosis. From this, the TVR was calculated and the geometric pattern of the left ventricle assessed. MAIN OUTCOME MEASURES: Fetal/maternal adverse outcomes (pre-eclampsia, preterm delivery, placental abruption, other maternal medical problems, fetal distress, neonatal low birthweight, admittance to neonatal intensive care unit and perinatal death). RESULTS: Ninety-two out of the 268 pregnancies showed adverse outcomes (34.3%). The best independent predictor for the composite of maternal and fetal complications was TVR (OR 64.4, 95% CI 25.9-160.1). The cutoff value was 1340 dyn seconds/cm(5) with a sensitivity and a specificity of 90 and 91%, respectively. Concentric geometry of the left ventricle was also an independent predictor (OR 4.72, 95% CI 1.85-12.04). CONCLUSIONS: Echocardiography could help in identifying women with EMGH who subsequently develop maternal and fetal complications, allowing a classification in high-risk (TVR > 1340 dyn seconds/cm(5), concentric geometry of the left ventricle) and low-risk women (TVR < 1340 dyn seconds/cm(5), nonconcentric geometry of the left ventricle) for adverse outcomes of pregnancy.

Helicobacter pylori eradication and l-dopa absorption in patients with PD and motor fluctuations.

OBJECTIVE: To investigate if Helicobacter pylori (HP) eradication could make an effective and long-lasting improvement in the pharmacokinetic and clinical response to l-dopa in patients with Parkinson disease (PD) and motor fluctuations. METHODS: In a group of 34 HP-infected, motor-fluctuating patients with PD, the short-term (1-week) and long-term (3-month) beneficial effect of HP eradication (n = 17) was investigated in a double-blind fashion in comparison with a generic antioxidant treatment (n = 17), by means of pharmacokinetic, clinical, and gastrointestinal assessments. Results were compared with placebo treatment. RESULTS: Differently from the antioxidant-treated patients, the HP-eradicated patients showed a significant increase of l-dopa absorption, which was coupled with a significant improvement of clinical disability and with a prolonged "on-time" duration, whereas gastritis/duodenitis scores significantly decreased in line with a better l-dopa pharmacokinetics. CONCLUSIONS: These data demonstrate a reversible Helicobacter pylori (HP)-induced interference with l-dopa clinical response related to the impaired drug absorption, probably due to active gastroduodenitis. Therefore, the authors suggest that HP eradication may improve the clinical status of infected patients with Parkinson disease and motor fluctuations by modifying l-dopa pharmacokinetics.

Electron dose radiation response of dyed PMMA detectors developed at IPEN.

Dyed polymethylmethacrylate (PMMA) detectors using yellow, red, blue and green colouring compounds, commercially available in Brazil, were originally developed and characterised using the optical absorption (OA) technique for gamma radiation, with the aim of obtaining a sensitive, useful, practical and cheap dosemeter for use in the quality control of industrial gamma radiation processing. In this work these detectors were evaluated for electron OA response, for use in the quality control of electron accelerator radiation processing. The studied parameters were the absorption spectra, dose-rate dependence between 2.66 and 45.22 kGy s(-1); dose response between 1.2 and 110 kGy; and energy dependence of response between 0.8 and 1.5 MeV electron energy.

Helicobacter pylori duodenal colonization is a strong risk factor for the development of duodenal ulcer.

AIM: To test the hypothesis that duodenal colonization represents the final crucial step in the development of Helicobacter pylori related duodenal ulcer. METHODS: Patients with non-ulcer dyspepsia who had gastric colonization by H. pylori were included in the study. At baseline endoscopy, we evaluated the prevalence of duodenal colonization (culture, urease testing and histology), and cytotoxin-associated gene A status (polymerase chain reaction). No patients received eradication during 1 year follow-up. At this time, endoscopy was repeated and the incidence of duodenal ulcer was assessed. RESULTS: Among 181 patients completing follow-up, 53 (29%) had duodenal colonization: 72% of them were cytotoxin-associated gene A positive, versus 37% patients without duodenal colonization (P < 0.001). Duodenal ulcer developed in 12 (22.6%) patients with duodenal colonization and in two (1.6%) without duodenal colonization (odds ratio for duodenal ulcer: 6.29, 95% confidence intervals 2.44-17.45). The incidence of duodenal ulcer was similar among cytotoxin-associated gene A positive and cytotoxin-associated gene A negative subjects with duodenal colonization: 21.05% versus 26.6%. CONCLUSIONS: The assessment of duodenal colonization by H. pylori in patients with non-ulcer dyspepsia is strongly predictive for the subsequent development of duodenal ulcer and may help to stratify patients at risk for this disease.

CagA-positive Helicobacter pylori strains may influence the natural history of atherosclerotic stroke.

OBJECTIVE: To test the hypothesis that infection with virulent cytotoxin-associated gene-A (CagA)-bearing Helicobacter pylori strains influences the atherosclerotic process and the clinical course in atherosclerotic stroke patients. METHODS: ELISA was used to assess the seroprevalence of infection by H. pylori and CagA-positive strains in 185 patients. Intima-media thickness (IMT) was determined by Doppler ultrasound. Baseline, 1-week, and 1-month NIH Stroke Scale (NIHSS) scores were used to evaluate the short-term clinical course. RESULTS: H. pylori infection was found in 79% of patients; 58% of these tested positive for CagA. IMT was higher among CagA-positive patients than among CagA-negative ones (1.13 +/- 0.26 mm vs 0.97 +/- 0.15 mm; univariate analysis, p = 0.0001; multivariate analysis, odds ratio [OR], 2.36; 95% CI, 1.57 to 3.54; p = 0.0001) or H. pylori-negative ones (1.01 +/- 0.17 mm; univariate analysis, p = 0.007; multivariate analysis, OR, 1.90; 95% CI, 1.22 to 2.97; p = 0.005). CagA-positive patients had poorer initial outcomes based on serial measurements of the NIHSS score (repeated measures analysis of variance, p < 0.0001). No significant difference in IMT and NIHSS score was found between H. pylori-positive and H. pylori-negative patients. CONCLUSIONS: Infection with cytotoxin-associated gene-A-positive Helicobacter pylori strains in atherosclerotic stroke patients is associated with greater intima-media thickness and poorer short-term outcome compared with cytotoxin-associated gene-A-negative patients.