Design and Fabrication of a Flexible Gravimetric Sensor Based on a Thin-Film Bulk Acoustic Wave Resonator

Sensing systems are becoming less and less invasive. In this context, flexible materials offer new opportunities that are impossible to achieve with bulky and rigid chips. Standard silicon sensors cannot be adapted to curved shapes and are susceptible to big deformations, thus discouraging their use in wearable applications. Another step forward toward minimising the impacts of the sensors can be to avoid the use of cables and connectors by exploiting wireless transmissions at ultra-high frequencies (UHFs). Thin-film bulk acoustic wave resonators (FBARs) represent the most promising choice among all of the piezoelectric microelectromechanical system (MEMS) resonators for the climbing of radio frequencies. Accordingly, the fabrication of FBARs on flexible and wearable substrates represents a strategic step toward obtaining a new generation of highly sensitive wireless sensors. In this work, we propose the design and fabrication of a flexible gravimetric sensor based on an FBAR on a polymeric substrate. The resonator presents one of the highest electromechanical coupling factors in the category of flexible AlN-based FBARs, equal to 6%. Moreover, thanks to the polymeric support layer, the presence of membranes can be avoided, which leads to a faster and cheaper fabrication process and higher robustness of the structure. The mass sensitivity of the device was evaluated, obtaining a promising value of 23.31 ppm/pg. We strongly believe that these results can pave the way to a new class of wearable MEMS sensors that exploit ultra-high-frequency (UHF) transmissions.

Wearable Heart Rate Monitoring Device Communicating in 5G ISM Band for IoHT

Advances in wearable device technology pave the way for wireless health monitoring for medical and non-medical applications. In this work, we present a wearable heart rate monitoring platform communicating in the sub-6GHz 5G ISM band. The proposed device is composed of an Aluminium Nitride (AlN) piezoelectric sensor, a patch antenna, and a custom printed circuit board (PCB) for data acquisition and transmission. The experimental results show that the presented system can acquire heart rate together with diastolic and systolic duration, which are related to heart relaxation and contraction, respectively, from the posterior tibial artery. The overall system dimension is 20 mm by 40 mm, and the total weight is 20 g, making this device suitable for daily utilization. Furthermore, the system allows the simultaneous monitoring of multiple subjects, or a single patient from multiple body locations by using only one reader. The promising results demonstrate that the proposed system is applicable to the Internet of Healthcare Things (IoHT), and particularly Integrated Clinical Environment (ICE) applications.

A compact evolved antenna for 5G communications

Flexible and bendable electronics are gaining a lot of interest in these last years. In this scenario, compact antennas on flexible substrates represent a strategical technological step to pave the way to a new class of wearable systems. A crucial issue to overcome is represented by the poor radiation properties of compact antennas, especially in the case of flexible and thin substrates. In this paper, we propose an innovative design of a miniaturized evolved patch antenna whose radiation properties have been enhanced with a Split Ring Resonator (SRR) placed between the top and the ground plane. The antenna has been realized on a flexible and biocompatible substrate polyethylene naphthalate (PEN) of 250 μm by means of a new fabrication protocol that involves a three-layer 3D-inkjet printing and an alignment step. The antenna has been characterized in terms of the scattering parameter S₁₁ and the radiation pattern showing a good agreement between simulations and measurements.

Rapid Prototyping of Bio-Inspired Dielectric Resonator Antennas for Sub-6 GHz Applications

Bio-inspired Dielectric Resonator Antennas (DRAs) are engaging more and more attention from the scientific community due to their exceptional wideband characteristic, which is especially desirable for the implementation of 5G communications. Nonetheless, since these antennas exhibit peculiar geometries in their micro-features, high dimensional accuracy must be accomplished via the selection of the most suitable fabrication process. In this study, the challenges to the manufacturing process presented by the wideband Spiral shell Dielectric Resonator Antenna (SsDRA), based on the Gielis superformula, are addressed. Three prototypes, made of three different photopolymer resins, were manufactured by bottom-up micro-Stereolithography (SLA). This process allows to cope with SsDRA's fabrication criticalities, especially concerning the wavy features characterizing the thin spiral surface and the micro-features located in close proximity to the spiral origin. The assembly of the SsDRAs with a ground plane and feed probe was also accurately managed in order to guarantee reliable and repeatable measurements. The scattering parameter S11 trends were then measured by means of a Vector Network Analyzer, while the realized gains and 3D radiation diagrams were measured in the anechoic chamber. The experimental results show that all SsDRAs display relevant wideband behavior of 2 GHz at -10 dB in the sub-6 GHz range.

Systematic review: interferon-free regimens for patients with HCV-related Child C cirrhosis

BACKGROUND

It is unclear whether the efficacy and long-term outcome of treating patients with hepatitis C virus (HCV)-positive cirrhosis with the new protease inhibitors will extend to those with Child C cirrhosis.

AIM

To assess the effectiveness of the interferon-free regimens in Child C cirrhotic patients with HCV infection.

METHODS

A systematic Medline search was conducted to retrieve studies describing the treatment of Child C patients with direct-acting agents. Citations from identified studies were cross-referenced and abstracts from European Association for the Study of the Liver (EASL) and American Association for the Study of Liver Disease (AASLD) meetings were checked. Extracted data were evaluated using a meta-analysis to calculate a weighted response rate.

RESULTS

Seven full-text records and two conference abstracts were retained for analysis from the 649 records identified. Data from an Italian real-life trial were also interrogated. Information on treatment outcome was available for 228 of the 240 Child C patients evaluated in the 10 trials. Overall, the weighted mean sustained virological response (SVR12) was 74.9% (95% CI: 65.6-82.4%). Neither duration of treatment (24 or 12 weeks), nor addition of ribavirin influenced these rates. The weighted SVR12 was 65.4% (95% CI: 46.8-80.2) after sofosbuvir/simeprevir, 76.0% (95% CI: 54.4-89.3%) after sofosbuvir/daclatasvir and 83.0% (95% CI: 73.4-89.6) after sofosbuvir/ledipasvir. Some studies did not provide information on the rate of post-treatment relapse or functional improvement. However, in those studies that did provide such data, a relapse was documented in 12.1% of patients and an improvement of ≥2 points on the model for end-stage liver disease (MELD) score in 61.1% of patients.

CONCLUSION

The improvement in MELD scores strongly suggests HCV-positive patients with Child C cirrhosis should be treated with these agents.

Variations of serum levels of adiponectin and resistin in chronic viral hepatitis

BACKGROUND AND AIMS

Several studies investigated the possible role of adipokines during chronic viral hepatitis, not producing defined results neither clearly establishing their behavior in course of anti-viral treatment. Our study evaluated blood concentrations of adiponectin and resistin in patients with chronic hepatitis C (CHC), B (CHB), and D (CHD) receiving anti-viral treatment, at baseline and after therapy.

METHODS

We examined 122 subjects, divided into two groups: 64 patients with chronic hepatitis C virus (HCV) infection (38 males and 26 females, mean age 47.25 yr) and 58 patients including 39 ones with chronic hepatitis B virus (HBV) infection (26 males and 13 females, mean age 48.46 yr) and 19 ones with chronic HBV-hepatitis D virus (HDV) infection (15 males and 4 females, mean age 45.79 yr). Serum levels of adiponectin and resistin were assayed by enzyme-linked immunosorbent assay.

RESULTS

In the group of CHC patients we observed a significant decrease in resistin after therapy (p=0.006), while not a significant increase in adiponectin after treatment (p=0.32). Evaluation of changes in adiponectin and resistin levels after anti-viral treatment, both in responders and non-responders, revealed no significant variations. In the group of HBV+ and HBV-HDV+ patients, we found a decrease in resistin after therapy (p=0.0016) and a not significant reduction in adiponectin after treatment (p=0.13). Furthermore, we noticed a significant reduction of resistin (p=0.006) in the sub-group of responders.

CONCLUSIONS

Our data suggested the possible marker role of adiponectin and resistin in the inflammatory process in course of chronic viral hepatitis.

Estimates of HCV-1 patients attaining RVR following dual therapy with peg-interferon and ribavirin

BACKGROUND

Given the significant side-effects and healthcare costs associated with telaprevir- or boceprevir-combination therapy, identifying patients likely to respond to dual therapy peg-interferon (Peg-IFN)/ribavirin is highly desirable. Since the perception of how large the pool of patients who may achieve rapid virologic response (RVR) is vaguely ascertained, we searched the literature for this information.

METHODS

Studies on patients treated with Peg-IFN/ribavirin were identified by searching MEDLINE and analyzed by meta-analysis. The primary end point was weighted estimates of RVR. The influence on race/ethnicity, baseline viremia, type of Peg-IFN, ribavirin dosage, and significant hepatic fibrosis on the results was evaluated.

RESULTS

Across 38 studies on 13,219 patients, the fraction of RVR patients was 19.6 %. The only baseline factor influencing RVR was race/ethnicity, with higher rates in Asian (26.7 %) and Caucasian patients (22.5 %). Of the 1,735 RVR patients, 85.1 % attained sustained virologic response (SVR). In these, SVR was influenced by ribavirin dose (86.8 vs. 72.8 % for high or low), type of Peg-IFN (91.8 % for alpha-2b vs. 82.9 % for alpha-2a), and treatment duration (91.7 % for 48 weeks vs. 79.4 % for 24 weeks).

CONCLUSIONS

One fifth to one fourth of hepatitis C virus genotype 1 (HCV-1) patients can be safely treated with dual therapy of Peg-IFN/ribavirin, and may be spared from cost and inconvenience of regimens considering the addition of HCV protease inhibitors.

Plasma adiponectin levels in primary biliary cirrhosis: a novel perspective for link between hypercholesterolemia and protection against atherosclerosis

INTRODUCTION

Hypercholesterolemia is a common finding in primary biliary cirrhosis (PBC), but the risk of cardiovascular events in PBC patients is not increased in respect to the general population. High serum adiponectin levels appear to play a protective role in the development of either metabolic syndrome or cardiovascular disease.

AIM

To investigate factors potentially preventing atherosclerosis in PBC patients.

METHODS

Circulating levels of adiponectin, resistin, leptin, and tumor necrosis factor-alpha (TNF-alpha) were measured in 137 consecutive PBC patients (125 women, 12 men; mean age 61.6 +/- 12.3 yr), 137 sex- and age-matched healthy controls, and 30 female patients with nonalcoholic steatohepatitis (NASH) and associated metabolic syndrome.

RESULTS

The body mass index (BMI) was comparable in the three groups, whereas total cholesterol was significantly higher in both PBC and NASH cases than in controls (221.6 +/- 50.5 mg/dL in PBC vs 221.7 +/- 39.7 mg/dL in NASH vs 209.8 +/- 39.2 mg/dL in controls, P < 0.05). Serum concentrations of adiponectin, resistin, and leptin were significantly higher in PBC patients than in either NASH cases or controls (P < 0.05). Among the PBC patients, only adiponectin correlated positively with histological progression of the disease (P= 0.001) and negatively with BMI (P= 0.01). Logistic regression analysis revealed that adiponectin correlated independently with age, BMI, Mayo score, and gamma-glutamyl transpeptidase.

CONCLUSIONS

The high adiponectin concentrations observed in PBC patients should be regarded as a possible protective factor against atherogenesis. The search for further protective factors should be encouraged.

The use of molecular assays in the management of viral hepatitis

Molecular assays are instrumental in the clinical management of viral hepatitis. During the past years, a wide variety of molecular assays have been developed and implemented. This considerably improved the understanding of the natural history and pathogenesis of Hepatitis B virus (HBV), Hepatitis C virus (HCV) or Hepatitis delta virus (HDV) hepatitis, but also caused uncertainties in the selection of the most appropriate assays for clinical requirements. Indeed, a rational choice and application of these assays requires adequate knowledge of the performance of the single test. Moreover, the choice of the most accurate assay for patients' needs and physicians' objectives, needs to be oriented to specific contexts, such as diagnosis, management or treatment. In the past, a hurdle in the routine use of assays for hepatitis viruses nucleic acid quantification was represented by the availability of only "home brew" methods which lacked standardization. Major improvement in addressing the use of molecular assays for viral hepatitis has been derived from recent standardization procedures that allowed a comparison between different tests after results were given as International Units. In addition, it should be reminded that, before getting into the market, molecular assays should be approved by European regulation authorities and validated using internationally recognized standards. A subsequent clinical validation should address the diagnostic accuracy of the assay. These proceedings have the aim of identifying which molecular tests, among those currently available, meet clinical requirements for each specific application.

Type I autoimmune hepatitis: clinical course and outcome in an Italian multicentre study

BACKGROUND

Many reports of autoimmune hepatitis (AIH) were written in the 'pre-Hepatitis C era' and data on the natural history are still incomplete.

AIM

To evaluate the clinical presentation and the natural history of type I AIH.

METHODS

Seventy-three consecutive patients with a regular follow-up of at least 2 years were prospectively included in the study. The mean follow-up was 91 +/- 61 months.

RESULTS

Patients with 'acute' onset at presentation were significantly older than patients with 'chronic' onset (P < 0.05) and had significantly higher serum levels of transaminase, gamma-glutamyltransferase and bilirubin; Prothrombin time was significantly lower in the said group compared with AIH patients with 'chronic' onset. In 4 of 63 (6.3%) female patients, AIH had the onset during pregnancy; in all of them the outcome of pregnancy was favourable. The major events during the follow-up included oesophageal varices (n = 9) and ascites (n = 4), and 60 patients remained in remission while receiving immunosuppression. None of the patients died during the follow-up, but seven patients were transplanted. The cumulative transplant-free probability of survival was 73.5% at 280 months.

CONCLUSIONS

Elderly patients have more frequently an acute onset at presentation. Survival in AIH is apparently good; with early diagnosis, and improved medical therapy, liver transplantation for AIH will become a rare event in future.

Ultrasonographic and biochemical parameters in the non-invasive evaluation of liver fibrosis in hepatitis C virus chronic hepatitis

BACKGROUND

Prior studies suggest that platelet counts of <140 000/microL can discriminate patients with different stages of fibrosis.

AIM

To determine the added value of abdominal ultrasound analysis of morphological liver features in increasing the diagnostic accuracy of platelet counts for the prediction of liver fibrosis at histology.

METHODS

In a retrospective study, clinical records of 1143 chronic hepatitis C patients at their first presentation, naives to both liver biopsy and anti-viral treatment, were reviewed. Sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios of following indices were evaluated singularly or in combination: platelet counts <140 000/microL; nodular liver surface, spleen and portal vein size.

RESULTS

All indices had specificity rate of > or =90% in excluding bridging fibrosis/cirrhosis, whereas sensitivity was acceptable (51%) for only platelet counts <140 000/microL. None of the ultrasonographic parameters singularly evaluated and reached an acceptable sensitivity rate. For ruling cirrhosis in or out, specificity rate was > or =82% for all tests, with the highest value reported by portal vein size. Low platelet counts plus nodular liver surface had the best sensitivity.

CONCLUSIONS

No additional significant predictive value was given by adding ultrasonographic parameters to low platelet counts, whereas only a mild non-significant improvement in sensitivity was obtained combining platelet counts <140 000/microL with the presence of nodular liver surface. The platelet counts <140 000/microL showed the best predictive value for including both significant fibrosis and cirrhosis.

Four years of treatment with lamivudine: clinical and virological evaluations in HBe antigen-negative chronic hepatitis B

AIM

To evaluate the clinical and virological impact of the prolonged use of lamivudine in 94 patients with HBe antigen-negative chronic hepatitis B.

METHODS

Initial virological and biochemical responses were obtained in 84 (89%) and in 83 (88%) patients respectively.

RESULTS

The virological response peaked within the first 12 months, but diminished to 39% at 48 months because of drug resistance. Overall a virological breakthrough developed in 44 patients (52.4%). After virological breakthrough, the actuarial probability of maintaining biochemical remission diminished to 15% at 24 months and 0% at 29 months. There was no response in 10.6%. Polymerase gene mutations were observed in 82.5% of virological breakthroughs but also in 75% of the non-responders. Overall 7.4% of patients developed a hepatocellular carcinoma.

CONCLUSION

Almost 90% of patients responded initially to lamivudine but the emergence of drug resistance progressively reduced the rate of virological remission to 39% at the fourth year of therapy. YMDD mutants explained the 75% of lamivudine resistances and were also selected very early in non-responders. Although the biochemical response is invariably lost within 29 months of the YMDD mutant's duration, the clinical outcome was benign despite severe postvirological breakthrough hepatitic flares in about 12% of cases.

Pharmacologic treatment can prevent pancreatic injury after ERCP: a meta-analysis

BACKGROUND

The identification of therapeutic agents that can prevent the pancreatic injury after endoscopic retrograde cholangiopancreatography (ERCP) is of considerable importance.

METHODS

We performed a meta-analysis including 28 clinical trials on the use of somatostatin (12 studies), octreotide (10 studies), and gabexate mesilate (6 studies) after ERCP. Outcome measures evaluated were the incidence of acute pancreatitis, hyperamylasemia, and pancreatic pain. Three analyses were run separately: for all available studies, for randomized trials only, and for only those studies published as complete reports.

RESULTS

When all available studies were analyzed, somatostatin and gabexate mesilate were significantly associated with improvements in all three outcomes. Odds ratios (OR) for gabexate mesilate were 0.27 (95% CI [0.13, 0. 57], p = 0.001) for acute pancreatitis, 0.66 (95% CI [0.48, -0.89], p = 0.007) for hyperamylasemia, and 0.33 (95% CI [0.18, 0.58], p = 0. 0005) for post-procedural pain. Somatostatin reduced acute pancreatitis (OR 0.38: 95% CI [0.22, 0.65], p < 0.001), pain (OR 0. 24: 95% CI [0.14, 0.42], p < 0.001), and hyperamylasemia (OR 0.65: 95% CI [0.48, 0.90], p = 0.008). Octreotide was associated only with a reduced risk of post-ERCP hyperamylasemia (OR 0.51: 95% CI [0.31, 0.83], p = 0.007) but had no effect on acute pancreatitis and pain. The statistical significance of data did not change after analyzing randomized trials only or studies published as complete reports. For each considered outcome, the publication bias assessment and the number of patients that need to be treated to prevent one adverse effect were, respectively, higher and lower for somatostatin than for gabexate mesilate.

CONCLUSIONS

The pancreatic injury after ERCP can be prevented with the administration of either somatostatin or gabexate mesilate, but the former agent is more cost-effective. Additional studies comparing the efficacy of short-term infusion of somatostatin versus gabexate mesilate in patients at high risk for post-ERCP complications seem warranted.

Changing pattern of chronic hepatitis D in Southern Europe

BACKGROUND & AIMS

The aim of this study was to assess changes in the clinical pattern of hepatitis D virus (HDV) infection in Italy, brought about by improved control of hepatitis B and D viruses, and to establish the natural history of chronic hepatitis D.

METHODS

Histological diagnosis and clinical features of 122 patients with HDV recruited from 1987 to 1996 in three Italian tertiary referral centers (Torino, northern Italy; San Giovanni Rotondo and Castellana Grotte, southern Italy) were compared with those of 162 patients collected in the same centers in the previous decade. Patients from both groups with at least 6 months of follow-up were included in a new subgroup to assess the natural history of the disease.

RESULTS

Among 162 patients referred from 1977 to 1986, 9 (6%) had mild hepatitis at histology vs. 9 (8%) of 122 patients referred in the second decade; 105 (65%) vs. 21 (17%) had severe hepatitis; 46 (28%) vs. 38 (31%) had histological asymptomatic cirrhosis; and 2 (1%) vs. 54 (44%) had clinically overt cirrhosis. For 159 patients (121 men and 38 women; mean age, 34 +/- 11), a follow-up of more than 6 months was documented, and they were included in the natural history subgroup. After 78 +/- 59 months of follow-up, 112 (70%) survived free of liver transplantation: 9 underwent transplantation, 32 died of liver failure, and 6 of acquired immunodeficiency syndrome. Estimated 5- and 10-year probability of survival free of orthotopic liver transplantation was 100% and 100% for patients with mild hepatitis, 90% and 90% for severe hepatitis, 81% and 58% for histological asymptomatic cirrhosis, and 49% and 40% for clinical cirrhosis (P < 0.01), respectively.

CONCLUSIONS

Occurrence of fresh and severe forms of hepatitis D has diminished greatly in Italy. Contemporary patients represent cohorts infected years ago who survived the immediate medical impact of hepatitis D. The disease has been asymptomatic and nonprogressive in a minority; in the majority, it rapidly advanced to cirrhosis but thereafter subsided with stable clinical conditions for more than a decade.

Intraduodenal lipase activity in celiac disease assessed by means of 13C mixed-triglyceride breath test

BACKGROUND

In patients with celiac disease, the occurrence of exocrine pancreatic insufficiency has been related to an impairment of the gut-mediated stimulatory effect of the meal on the pancreas. The purpose of this study was to assess the intraduodenal lipase activity in patients with celiac disease by means of the 13C mixed-triglyceride breath test and to monitor pancreatic function after the institution of a gluten-free diet.

METHODS

Seventeen untreated patients with celiac disease (mean age, 17.4 +/- 10.5 years) were studied. After an overnight fast, patients were given a standard test meal consisting of 100 g of white bread and 0.25 g of butter per kilogram of body weight, to which 16 mg di-stearyl-13C-octanoyl-glyceride (mixed triglyceride) had been added. Breath samples were taken twice at baseline and at 30-minute intervals for 6 hours after the meal. 13C enrichment in breath was determined by means of Isotope Ratio Mass Spectrometer (IRMS) (ANCA-NT; Europa Scientific, Crewe, UK). Results were expressed as the maximum percentage of 13C recovery per hour at any time, the time to reach peak excretion of 13C, and the percentage of 13C cumulative dose over 6 hours.

RESULTS

Mixed-triglyceride breath test results were pathologic in three patients and at the lower limit of the normal range in another patient. In the remaining 13 patients, the results were within normal values. At the 6- and 12-month follow-ups, all patients showed normal intraduodenal lipase activity.

CONCLUSIONS

In approximately 24% of patients with celiac disease, the intraduodenal pancreatic lipolytic activity is impaired. The mixed-triglyceride breath test could be used to assess fat maldigestion and to monitor the need for enzyme replacement therapy in such patients.

Helicobacter pylori infection may undergo spontaneous eradication in children: a 2-year follow-up study

BACKGROUND

Helicobacter pylori infection is generally acquired early in life. However, it is still unknown whether a spontaneous eradication can occur. The purpose of this study was to evaluate whether H. pylori infection can undergo spontaneous eradication in children.

METHODS

Three hundred and four Italian children (age range, 4.5 to 18.5 years) were tested for H. pylori by means of 13C-urea breath test. Infected children were followed up every 6 months for as long as 2 years. Parents were instructed to record consumption of antibiotics. At each visit, children underwent a repeat 13C-urea breath test.

RESULTS

Eighty-five out of 304 (27.9%) children were H. pylori infected. Forty-eight out of 85 infected children (56.4%) participated in the follow-up study. After 2 years, 8 (16.6%) infected children had negative results on 13C-urea breath tests; 2 of them were given antibiotics for concomitant infections. One child was negative at 6 months but became positive again at the next 6-month 13C-urea breath test. Forty children remained persistently positive; of them, 10 were treated with a short course of antibiotics.

CONCLUSIONS

Our findings support the hypothesis that, at least during childhood, H. pylori infection may be a fluctuating disease with spontaneous eradication and possible recurrence.

Relationship between the results of pre-treatment urea breath test and efficacy of eradication of Helicobacter pylori infection

AIMS

This study was carried out to evaluate whether the 13C-urea breath test could assess the intragastric Helicobacter pylori load and predict the outcome of infected subjects undergoing short-term triple therapy.

METHODS

A total of 108 infected patients underwent upper endoscopy with antral biopsies and histological grading of Helicobacter pylori density. These patients received omeprazole 20 mg b.i.d., clarithromycin 500 mg b.i.d., and amoxycillin 1000 mg b.i.d. or tinidazole 500 mg b.i.d. for one week. 13C-urea breath test (75 mg 13C-urea; results expressed as Delta Over Baseline values at 30') was performed before and after therapy. According to pre-treatment Delta Over Baseline at 30' values, patients were assigned to low (< 16/1000), intermediate (16-35/1000) and high (> 35/1000) Delta Over Baseline at 30' groups.

RESULTS

A significant correlation was found between pre-treatment Delta Over Baseline at 30' values and the density of Helicobacter pylori (rs = 0.76). The eradication rates were 82%, 67%, and 17% in the low, intermediate, and high Delta Over Baseline at 30' groups, respectively (p = 0.0001). When classified according to the outcome of therapy, the median pre-treatment Delta Over Baseline at 30' value was 15.7 in eradicated subjects vs 21.6 in non eradicated patients (p = 0.002). In patients who failed eradication, a significant difference was also observed between pre- and post-treatment Delta Over Baseline at 30' values (21.6 vs 15.6, p = 0.019).

CONCLUSIONS

The 13C-urea breath test can be used to evaluate the intragastric bacterial load and to predict the outcome of standard eradication treatment.

13C-octanoic acid breath test: a reliable tool for measuring gastric emptying

Non-invasive evaluation of gastric emptying is generally performed by scintigraphy which is, however, not always applicable and is not suitable for children and child-bearing women. Recently, a new method based on stable isotope breath testing has been introduced in clinical practice i.e., the 13C-octanoic acid breath test. An overview is made here of the current knowledge on this technique with special emphasis on the principle of the test, the mathematics used to analyse the results, and the physiological, pathological, and pharmacological aspects of gastric emptying studied with this new method. Possible pitfalls of the test are also reported.