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Direct current-superconducting quantum interference devices (SQUIDs) characterized by asymmetric Josephson junctions have never been used for applications. In order to demonstrate their potential advantages, a throughout numerical analysis of different asymmetric configurations has been carried out. A damping resistance has been included in the SQUID circuit and the thermal noise associated with junction and damping resistances has been considered in the numerical model. Magnetic modulations and flux noise spectral densities have been computed as a function of many parameters (bias current, asymmetry, SQUID inductance, and damping resistance) and the performance of symmetric and asymmetric devices have been compared. The results show that, by properly optimizing the SQUID design, asymmetric SQUIDs are characterized by higher magnetic flux to voltage transfer coefficient and lower flux noise. As a result, asymmetric configurations can be very useful in all the applications where high sensitivity is required. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Background Acid exposure time ( AET) is considered the most useful parameter to predict response of reflux-related heartburn to medical or surgical treatment. However, recent studies showed high rates of heartburn response to proton pump inhibitor ( PPI) therapy in patients with normal AET. We aimed to compare the efficacy of postreflux swallow-induced peristaltic wave ( PSPW) index and mean nocturnal baseline impedance ( MNBI) with AET in linking PPI-responsive heartburn to reflux. Methods Off-therapy impedance- pH tracings from 425 patients, 317 with PPI-responsive and 108 with PPI-refractory heartburn were blindly re-analyzed. Demographic and endoscopic characteristics, conventional impedance- pH variables, PSPW index, and MNBI were assessed with multivariate logistic regression to identify factors independently associated with PPI responsiveness. Prediction models were developed to assess the strength of reflux linkage with factors independently associated with PPI responsiveness by calculating the area under the curve ( AUC) at receiver-operating-characteristic ( ROC) analysis. Key Results At multivariate logistic regression analysis, AET, MNBI, and PSPW index were the only factors independently associated with PPI responsiveness, abnormal values found in 60%, 76%, and 92% of PPI-responsive cases ( P<.017). At ROC analysis, PSPW index ( AUC:.794, P=.002) and MNBI ( AUC: 0.742, P=.003), both separately and combined ( AUC: 0.811, P<.001) linked reflux with PPI-responsiveness better than AET ( AUC: 0.687). Conclusions & Inferences AET, PSPW index, and MNBI are independently associated with PPI-responsive heartburn. PSPW index and MNBI can link PPI-responsive heartburn to reflux better than AET and should become part of the standard analysis of impedance- pH tracings. [ABSTRACT FROM AUTHOR]

Background On-therapy impedance- pH monitoring in proton pump inhibitor ( PPI)-refractory gastroesophageal reflux disease ( GERD) yielded conflicting results. We aimed to assess the diagnostic value of postreflux swallow-induced peristaltic wave ( PSPW) index and mean nocturnal baseline impedance ( MNBI) in PPI-refractory heartburn. Methods On-therapy impedance- pH tracings from 189 consecutive patients with PPI-refractory heartburn were blindly reviewed. Patients were subdivided into refractory reflux esophagitis ( RRE), healed reflux esophagitis ( HRE), non-erosive reflux disease ( NERD), and functional heartburn ( FH) according to endoscopic and conventional impedance- pH findings. The diagnostic accuracy of PSPW index and MNBI in separating NERD from FH was assessed with receiver-operating-characteristic ( ROC) analysis. Objectively documented persistent reflux remission at 3-year follow-up in 53 patients who underwent laparoscopic fundoplication served to evaluate PSPW index and MNBI as independent predictors of PPI-refractory GERD confirmed by positive surgical outcome. Key Results Median PSPW index and MNBI values were significantly lower in 39 RRE (16%; 1145 Ω) than in 41 HRE (25%; 1741 Ω) and in 68 NERD (29%; 2374 Ω) patients, and in all three GERD subgroups compared to 41 FH cases (67%; 3488 Ω) ( P<.008). At ROC analysis, comparing NERD to FH the area under the curve was 0.886 with PSPW index and 0.677 with MNBI ( P=.005). PSPW index was an independent predictor of PPI-refractory GERD (odds ratio 0.6983, P=.012). Conclusions & Inferences At on-therapy impedance- pH monitoring, PSPW index and MNBI efficiently distinguish PPI-refractory NERD from FH. The PSPW index represents an independent predictor of PPI-refractory GERD. [ABSTRACT FROM AUTHOR]

Gastroesophageal reflux disease (GERD) is a common disorder of the upper gastrointestinal tract which is typically characterized by heartburn and acid regurgitation. These symptoms are widespread in the community and range from 2.5% to more than 25%. Economic analyses showed an increase in direct and indirect costs related to the diagnosis, treatment and surveillance of GERD and its complications. The aim of this review is to provide current information regarding the natural history of GERD, taking into account the evolution of its definition and the worldwide gradual change of its epidemiology. Present knowledge shows that there are two main forms of GERD, that is erosive reflux disease (ERD) and non-erosive reflux disease (NERD) and the latter comprises the majority of patients (up to 70%). The major complication of GERD is the development of Barrett esophagus, which is considered as a pre-cancerous lesion. Although data from medical literature on the natural history of this disease are limited and mainly retrospective, they seem to indicate that both NERD and mild esophagitis tend to remain as such with time and the progression from NERD to ERD, from mild to severe ERD and from ERD to Barrett's esophagus may occur in a small proportion of patients, ranging from 0 to 30%, 10 to 22% and 1 to 13% of cases, respectively. It is necessary to stress that these data are strongly influenced by the use of powerful antisecretory drugs (PPIs). Further studies are needed to better elucidate this matter and overcome the present limitations represented by the lack of large prospective longitudinal investigations, absence of homogeneous definitions of the various forms of GERD, influence of different treatments, clear exclusion of patients with functional disorders of the esophagus. [ABSTRACT FROM AUTHOR]

Background Multiple rapid swallowing ( MRS) during high-resolution manometry ( HRM) is increasingly utilized as provocative test to assess esophageal peristaltic reserve. The aim of this study was to evaluate the correlation between MRS response and impedance and pH ( MII-pH) parameters in endoscopy negative heartburn ( ENH) patients. Methods We enrolled consecutive ENH patients, who underwent HRM and MII-pH study, with a selected MII-pH profile: abnormal MII-pH (pH+/ MII+); normal MII-pH (pH−/ MII−). HRM was performed with 10 wet swallows ( WS) and one MRS. Mean distal contractile integral ( DCI) during WS and MRS were calculated. MII-pH parameters including acid exposure time ( AET), reflux events, baseline impedance levels ( BI) and the efficacy of chemical clearance evaluated with the postreflux swallow-induced peristaltic wave ( PSPW) index were measured. Key Results We analyzed 103 patients: 49 MII+/pH+ (27 male), and 54 MII−/pH− (19 male). Mean age was similar between the two groups. As expected, mean AET and number of refluxes were higher in pH+/ MII+ ( p < 0.05). HRM was normal in all selected patients. Mean DCI- WS was similar between two groups ( p = n.s.). Mean DCI- MRS- was higher in MII−/pH− vs MII+/pH+ ( p < 0.05). The increase in DCI- MRS was inversely correlated with AET (−0.699; p < 0.001) and directly correlated with BI values (0.631; p < 0.001) and PSPW index (0.626; p < 0.001). Conclusions & Inferences Following MRS, patients with abnormal impedance-pH test showed suboptimal contraction response as compared with those with normal impedance-pH test. Moreover, MRS response was inversely correlated with AET and directly correlated with BI values and PSPW index. [ABSTRACT FROM AUTHOR]

A wide variety of pieces of evidence has suggested that obesity is associated with a significant increase in the risk for gastroesophageal reflux disease ( GERD) symptoms and its complications. The aim of this study was to evaluate the effect of weight loss on reflux symptoms in overweight/obese patients with proven GERD. We enrolled overweight/obese patients with typical GERD symptoms and erosive esophagitis. At baseline, patients underwent detailed reflux symptoms evaluation and anthropometric assessment, and were divided into two treatment groups: group A received proton pump inhibitor ( PPI) and a personalized hypocaloric diet and aerobic exercise; and group B received PPI and a 'standard of care diet'. The dietetic treatment was considered effective if at least 10% of weight loss was achieved within 6 months. All patients were evaluated in terms of anthropometric data, GERD symptoms, and PPI use. In group A, mean body mass index ( BMI) decreased from 30.3 ± 4.1 to 25.7 ± 3.1 ( P < 0.05), and mean weight decreased from 82.1 ± 16.9 kg to 69.9 ± 14.4 kg ( P < 0.05). In group B, there was no change in BMI and weight. Symptom perception decreased ( P < 0.05) in both groups during PPI therapy, but a higher improvement was recorded in group A. In group A, PPI therapy was completely discontinued in 27/50 of the patients, and halved in 16/50. Only 7/50 continued the same PPI dosage. In group B, 22/51 halved the therapy and 29/51 maintained full dosage of therapy, but none was able to discontinue PPI due to a symptom recurrence. Overall, weight loss of at least 10% is recommended in all patients with GERD in order to boost the effect of PPI on reflux symptom relief and to reduce chronic medication use. [ABSTRACT FROM AUTHOR]

Background The role of esophagogastric junction contractile integral ( EGJ- CI) as assessed by high-resolution manometry ( HRM) is unclear. We aimed to correlate the EGJ- CI with impedance-pH findings in gastro-esophageal reflux disease ( GERD) patients. Methods Consecutive patients with GERD symptoms were enrolled. All patients underwent upper endoscopy, HRM, and impedance-pH testing. The EGJ- CI was calculated using the distal contractile integral tool box during three consecutive respiratory cycles. The value was then divided by the duration of these cycles. A value below 13 was considered as a defective EGJ- CI. We also assessed EGJ morphology, esophageal acid exposure time ( AET), number of reflux episodes ( NRE), and symptom association analysis ( SAA). A positive impedance-pH monitoring was considered in case of abnormal AET and/or NRE and/or positive SAA. Key Results Among 130 patients we enrolled, 91 had GERD (abnormal AET and/or elevated NRE and/or positive SAA) and 39 had functional heartburn ( FH) (negative endoscopy, normal AET, normal NRE, and negative SAA). The GERD patients had a lower median value of EGJ- CI (11 [3.1-20.7] vs 22 [9.9-41], p < 0.02) compared to FH patients. Patients with a defective EGJ- CI had, more frequently, a positive impedance-pH monitoring or esophageal mucosal lesions at endoscopy ( p < 0.05 and p < 0.05, respectively) than patients with a normal EGJ- CI. An EGJ- CI cut-off value of 5 mmHg cm yielded the optimal performance in identifying GERD at impedance-pH (sensitivity 89%-specificity 63%). Conclusions & Inferences A defective EGJ- CI at HRM is clearly associated with evidence of GERD at impedance-pH monitoring. Evaluating EGJ- CI may be useful to predict an abnormal impedance-pH testing. [ABSTRACT FROM AUTHOR]

Full-arch immediate loading implant rehabilitations provide patients with compromised dentition an effective treatment to improve their aesthetic and function. Aim of this prospective cohort study was to investigate the correlation between masticatory ability and gastric emptying rates among these patients. Ten subjects (five men and five women) with compromised dentition were tested in two occasions: before treatment and 30 days after the immediate loading rehabilitation. Masticatory ability was evaluated using the sieves test, and the gastric half emptying time (T1/2) was assessed by means of the 13C-octanoic acid breath test. A statistically significant increment (P < 0.005) in masticatory ability was found only in reference to the particles smaller than or equal to 4.75 mm, whereas the gastric emptying rate showed a statistically significant reduction between pre- and post-treatment (P = 0.003). A moderate negative correlation (rho = 0.64, P = 0.048) between the percentage change in masticatory ability and the percentage change in gastric emptying rate was evidenced. Patients with compromised dentition rehabilitated with full-arch immediate implant prostheses present a significant improvement of the gastric process. [ABSTRACT FROM AUTHOR]

Background High-resolution manometry ( HRM) provides information on esophagogastric junction ( EGJ) morphology, distinguishing three different subtypes. Data on the correlation between EGJ subtypes and impedance-pH detected reflux patterns are lacking. We aimed to correlate the EGJ subtypes with impedance-pH findings in patients with reflux symptoms. Methods Consecutive patients with suspected gastroesophageal reflux disease ( GERD) were enrolled. All patients underwent HRM and impedance-pH testing off-therapy. EGJ was classified as: Type I, no separation between the lower esophageal sphincter ( LES) and crural diaphragm ( CD); Type II, minimal separation (>1 and <2 cm); Type III, ≥2 cm separation. We measured esophageal acid exposure time ( AET), number of total reflux episodes and symptom association analysis. Key Results We enrolled 130 consecutive patients and identified 46.2% Type I EGJ, 38.5% Type II, and 15.4% Type III patients. Type III subjects had a higher number of reflux episodes (61 vs 45, p < 0.03, vs 25, p < 0.001), a greater mean AET (12.4 vs 4.2, p < 0.02, vs 1.5, p < 0.001) and a greater positive symptom association (75% vs 72%, p = 0.732 vs 43.3%, p < 0.02) compared with Type II and I patients, respectively. Furthermore, Type II subjects showed statistically significant (overall p < 0.01) increased reflux when compared with Type I patients. Type III and II EGJ morphologies had a more frequent probability to show a positive multichannel intraluminal impedance pH monitoring than Type I (95% vs 84% vs 50%, p < 0.001). Conclusions & Inferences Increasing separation between LES and CD can cause a gradual and significant increase in reflux. EGJ morphology may be useful to estimate an abnormal impedance-pH testing in GERD patients. [ABSTRACT FROM AUTHOR]

Background Gastro-oesophageal reflux disease (GERD) may contribute to the onset of chronic cough (CC); however, the multichannel intraluminal impedance-pH (MII-pH) monitoring is often within the normal range and the response to proton pump inhibitors (PPIs) unsatisfactory. The measure of impedance baseline (IB) increases the sensitivity of MII-pH in patients with typical symptoms. Aim To evaluate the role of MII-pH variables, including IB, in predicting PPI response and to define the characteristics of the reflux pattern in CC patients. Methods Prospectively selected CC patients suspected GERD-related underwent MII-pH monitoring and, therefore, received a double dose of PPIs for at least 6 weeks. Patients filled symptom scores before MII-pH and after PPI therapy. MII-pH data were compared with those obtained in 60 non-erosive reflux disease patients with typical symptoms. Results A total of 156 CC patients entered the study: 68 (43.5%) responders and 88 (56.5%) nonresponders to PPIs. The number of reflux episodes was significantly higher in CC compared with that in typical symptoms patients. Nonresponder CC patients with a pathological acid exposure time ( AET) and/or IB value were 43/88 (49%), while 15/88 (17%) presented only pathological AET ( P < 0.001). CC patients with a pathological AET or IB, or with both a pathological AET and IB, showed a probability of PPI response twofold greater than patients with normal AET and IB. Conclusions The presence of a pathological AET or pathological IB in CC patients is associated with a greater probability of PPI response. IB is a promising variable in patients with CC, as it increases the diagnostic yield of MII-pH and allows confirmation of the GERD diagnosis in these patients. [ABSTRACT FROM AUTHOR]

Background A short-course of proton pump inhibitors ( PPIs) is often used to confirm gastroesophageal reflux disease ( GERD). However, some patients with PPI responsive heartburn do not seem to have evidence of GERD on impedance-pH monitoring (MII-pH). The aim of the study was to evaluate patients with reflux symptoms and a negative endoscopy, who well respond to PPIs with MII-pH. Methods We enrolled 312 patients with GERD symptoms and negative endoscopy: 144 reported well-controlled symptoms after 8-week PPIs and 155 were non-responders. Symptom relief was evaluated with GERD Impact Scale and visual analog scale score. All patients underwent MII-pH off-therapy. Thirteen patients were excluded from analysis. Patients were grouped as follows: non-erosive reflux disease ( NERD; increased acid exposure time, AET); hypersensitive esophagus ( HE; normal AET, positive symptom association, SI/ SAP); MII-pH-/ PPI+ (normal AET, negative SI/ SAP) in the responder group; MII-pH-/ PPI- in non-responders. Key Results MII-pH in PPI responders (symptom relief during PPI therapy > 75%) showed: 79/144 NERD (54.9%); 37/144 HE (25.7%); 28/144 MII-pH-/ PPI+ (19.4%). MII-pH-/ PPI+ patients reported the same symptom relief when compared with NERD and HE. In non-responder (symptom relief during PPI therapy < 50%) group, 27/155 patients were NERD (17.4%); 53/155 were HE (34.2%); 75/155 were MII-pH-/ PPI- (48.4%). NERD diagnosis was significantly higher in responder group (p < 0.01). Conclusions & Inferences In a substantial subgroup of patients responding to PPI with typical reflux symptoms, the diagnosis of GERD cannot be confirmed with pH-impedance monitoring. Proton pump inhibitor response and presence of typical symptoms are thus not reliable predictors of the diagnosis and antireflux surgery should always be preceded by reflux monitoring. [ABSTRACT FROM AUTHOR]

Aliment Pharmacol Ther 2010; 32: 1000-1006 Summary Background Abnormal intestinal clearance is involved in the pathogenesis of small intestinal bacterial overgrowth (SIBO). It is known that partially hydrolysed guar gum affects intestinal motility. Eradication therapy of SIBO is based on antibiotic treatment: no data are available on the role of fibre supplementation in eradicating SIBO. Aim To assess whether the combination of partially hydrolysed guar gum and rifaximin is more effective than rifaximin alone in the treatment of SIBO. Methods A 50 g-glucose breath test was given to 500 consecutive patients. Patients with a positive glucose breath test and predisposing conditions to SIBO entered into the study, and were randomized to receive rifaximin 1200 mg/day or rifaximin 1200 mg/day plus partially hydrolysed guar gum 5 g/day for 10 days. Patients completed a symptom questionnaire and glucose breath test both in basal condition and 1 month after withdrawal of therapy. Results Seventy-seven patients had SIBO. Eradication rate of SIBO was 62.1% in the rifaximin group (both on per-protocol and intention-to-treat analyses), and 87.1% (per-protocol, P = 0.017) and 85.0% (intention-to-treat, P = 0.036) in the rifaximin-plus-partially hydrolysed guar gum group. Clinical improvement was observed in 86.9% and 91.1% of eradicated cases in rifaximin and rifaximin-plus-partially hydrolysed guar gum groups respectively ( P = 0.677). Conclusion The combination of rifaximin with partially hydrolysed guar gum seems to be more useful in eradicating SIBO compared with rifaximin alone. [ABSTRACT FROM AUTHOR]

Semantic web and grid technologies offer a promising approach to facilitate semantic information retrieval based on heterogeneous document repositories. In this paper the authors describe the design and implementation of an Ontology Server (OS) component to be used in a distributed contents management grid system. Such a system could be used to build collection document repositories, mutually interoperable at the semantic level. From the contents point of view, the distributed system is built as a collection of multimedia documents repository nodes glued together by an OS. A set of methodologies and tools to organize the knowledge space around the notion of contents community is developed, where each content provider will publish a set of ontologies to collect metadata information organized and published through a knowledge community, built on top of the OS. These methodologies were deployed while setting up a prototype to connect about 20 museums in the city of Naples (Italy). [ABSTRACT FROM AUTHOR]

Bronchial artery embolisation (BAE) is an accepted method of controlling haemoptysis in patients with cystic fibrosis. However, anomalous origin of the bronchial arteries, documented in anatomical and angiographic studies, makes the procedure more difficult and increases the number of recurrences. Clinical records and films from three patients affected by cystic fibrosis with haemoptysis, in which the origin of the bleeding vessels was considered anomalous, out of a total of seven patients who underwent BAE, were reviewed. In two patients the source of bleeding was identified from, respectively, the left and the right internal mammary artery and in one from the left thyrocervical trunk. All the vessels considered to be the possible source of haemoptysis were embolised; immediate control of haemoptysis after embolisation was achieved in all patients, but minor haemoptysis recurred in two patients who were conservatively treated. In haemoptysis in patients with cystic fibrosis the possibility of anomalous origin of the bronchial arteries should be considered. This frequency may be higher than in other pulmonary diseases that cause haemoptysis, so a search for anomalous bronchial arteries is mandatory to achieve accurate embolisation and reduce the rate of recurrence. [ABSTRACT FROM AUTHOR]

SQUID configurations with an asymmetry in both the critical current and the normal resistance of the two Josephson junctions have been numerically analyzed. The analysis has been carded out on a high performance computer, by choosing parameters typical of low critical temperature SQUIDs, In particular the dependence of both the magnetic flux noise S[sub θ] and the flux to voltage transfer function V[sub θ] on the bias current and the normalized SQUID inductance β have been investigated. Thermal noise effects, including contributions of both junction and damping resistance, have been introduced in the calculations. The results show that an increase of the asymmetry leads to higher V[sub θ] and lower S[sub θ] values. This suggests to use asymmetric dc-SQUIDs to improve the device performance for both small and large inductance values. [ABSTRACT FROM AUTHOR]

Direct current superconducting quantum interference devices made by Josephson junctions with asymmetric shunt resistances have been numerically investigated in the low temperature regime. When combined with a damping resistance, the asymmetry leads to a flux to voltage transfer coefficient several times larger than the one typical of symmetric devices, together with a lower magnetic flux noise. These results show that this type of asymmetric device may replace the standard ones in a large number of magnetometric applications, improving the sensitivity performance. The large transfer coefficient may also simplify the readout electronics allowing a direct coupling of asymmetric devices to an external preamplifier, without the need of an impedance matching flux transformer. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Investigation of faecal volatile organic metabolites as novel diagnostic biomarkers in inflammatory bowel disease" in the previous issue is presented.

The article presents a case study of two patients with signet ring cell (SRC) cancer of the stomach, wherein the results of endocytoscopy (ECS) correlated with histologic examination.

A letter to the editor is presented in response to the article "Meta-analysis: Antibiotic therapy for small intestinal bacterial overgrowth" by S. C. Shah and colleagues in the 2013 issue.