Simultaneous detection of mycotoxins and pesticides in human urine samples: A 24-h diet intervention study comparing conventional and organic diets in Spain.

Pesticides and mycotoxins, prominent chemical hazards in the food chain, are commonly found in plant-based foods, contributing to their pervasive presence in the human body, as evidenced by biomonitoring programs. Despite this, there is limited knowledge about their co-occurrence patterns. While intervention studies have demonstrated that organic diets can significantly reduce pesticide levels, their impact on mycotoxin exposure has been overlooked. To address this gap, this study pursued two objectives: first, to characterize the simultaneous presence of mycotoxins and pesticides in human urine samples by means of the control of the biomarkers of exposure, and second, to investigate the influence of consuming organic foods on these co-exposure patterns. A pilot study involving 20 healthy volunteers was conducted, with participants consuming either exclusively organic or conventional foods during a 24-h diet intervention in autumn 2021 and spring 2022 to account for seasonal variability. Participants provided detailed 24-h dietary records, and their first-morning urine samples were collected, minimally treated and analysed using LC-Q-ToF-MS by means of a multitargeted method in order to detect the presence of these residues. Results indicated that among the 52 screened compounds, four mycotoxins and seven pesticides were detected in over 25% of the samples. Deoxynivalenol (DON) and the non-specific pesticide metabolite diethylphosphate (DEP) exhibited the highest frequency rates (100%) and concentration levels. Correlations were observed between urine levels of mycotoxins (DON, ochratoxin alpha [OTα], and enniatin B [ENNB]) and organophosphate pesticide metabolites DEP and 2-diethylamino-6-methyl-4-pyrimidinol (DEAMPY). The pilot intervention study suggested a reduction in ENNB and OTα levels and an increase in ß-zearalenol levels in urine after a short-term replacement with organic food. However, caution is advised due to the study's small sample size and short duration, emphasizing the need for further research to enhance understanding of the human chemical exposome and refine chemical risk assessment.

Assessing human exposure to pesticides and mycotoxins: optimization and validation of a method for multianalyte determination in urine samples.

Humans are exposed to an increasing number of contaminants, with diet being one of the most important exposure routes. In this framework, human biomonitoring is considered the gold standard for evaluating human exposure to chemicals. Pesticides and mycotoxins are chemicals of special concern due to their health implications. They constitute the predominant border rejection notifications for food and feed in Europe and the USA. However, current biomonitoring studies are focused on a limited number of compounds and do not evaluate mycotoxins and pesticides together. In this study, an analytical method has been developed for the determination of 30 pesticides and 23 mycotoxins of concern in urine samples. A salting-out liquid-liquid extraction (SALLE) procedure was optimized achieving recoveries between 70 and 120% for almost all the compounds and limits as lower as when QuEChERS was applied. The compounds were then determined by liquid chromatography coupled to triple quadrupole mass spectrometry. Different chromatographic conditions and analytical columns were tested, selecting a Hypersild gold aQ column as the best option. Finally, the method was applied to the analysis of 45 urine samples, in which organophosphate and pyrethroid pesticides (detection rates (DR) of 82% and 42%, respectively) and ochratoxin A and deoxynivalenol (DR of 51% and 33%, respectively) were the most detected compounds. The proposed analytical method involves the simultaneous determination of a diverse set of pesticides and mycotoxins, including their most relevant metabolites, in human urine. It serves as an essential tool for biomonitoring the presence of highly prevalent contaminants in modern society.

Cuff-assisted versus cap-assisted colonoscopy for adenoma detection: results of a randomized study.

BACKGROUND: The adenoma detection rate (ADR) is the most important marker of colonoscopy quality. Devices to improve adenoma detection have been developed, such as the Endocuff and transparent cap. The aim of the current study was to examine whether there was a difference in ADR between Endocuff-assisted (EAC) and cap-assisted colonoscopy (CAC). METHODS: A randomized prospective trial was conducted. Eligible patients included adults ≥ 18 years referred because of symptoms, surveillance, or colonoscopies as part of the Bowel Cancer Screening Programme (BCSP). The primary outcome measure was ADR. Secondary outcomes included mean number of adenomas, mean number of polyps, polyp detection rate, cecal intubation rate, and time to cecal intubation. Procedural measures, device removal rate, and adverse events were also recorded. RESULTS: A total of 711 patients (51.1 % men; median age 63 years) were included, of whom 357 patients were randomized to EAC and 354 patients to CAC. In the intention-to-treat analysis, the ADR was similar in both groups: EAC 50.4 % (95 % confidence interval [CI] 45.1 - 55.7) vs. CAC 50.6 % (95 %CI 45.2 - 55.9). Similar results were obtained in the per-protocol analysis: EAC 51.6 % (95 %CI 46.2 - 57) vs. CAC 51.4 % (95 %CI 46 - 56.8). There were no differences between the two devices in ADR according to the mean number of adenomas and polyps per procedure, polyp detection rate, cecal intubation rate, and time to cecal intubation. Device removal rate and adverse events were also similar. CONCLUSION: In this randomized study, no differences in ADR were found between Endocuff- and cap-assisted colonoscopy.

Simultaneous determination of atropine and scopolamine in buckwheat and related products using modified QuEChERS and liquid chromatography tandem mass spectrometry.

A method was developed for the determination of atropine and scopolamine in buckwheat and related products. A modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction procedure was evaluated. Dispersive solid phase extraction (d-SPE) was studied as clean-up step, using graphitized black carbon (GBC) and primary secondary amine (PSA). The extract was diluted with water (50:50, v/v) prior to chromatographic analysis. The method was validated and recoveries (except chia samples spiked at 10µg/kg) ranged from 75% to 92%. Intra and inter-day precision was lower than or equal to 17%. The limit of quantification of atropine and scopolamine was 0.4 and 2µg/kg, respectively. Eight types of samples (buckwheat, wheat, soy, buckwheat flour, buckwheat noodle, amaranth grain, chia seeds and peeled millet) were analyzed. Target compounds were not found above the detection limits of the method, but three transformation products of scopolamine (norscopine, hydroscopolamine and dihydroxyscopolamine) were putative identified in the tested samples using high resolution mass spectrometry (Exactive-Orbitrap).

Enantiomeric determination and evaluation of the racemization process of atropine in Solanaceae seeds and contaminated samples by high performance liquid chromatography-tandem mass spectrometry.

A new method has been developed for the enantioselective separation of (-) and (+) hyoscyamine in Solanaceaes seeds and contaminated buckwheat. Chromatographic separation was optimized, evaluating two chiral columns, Chirobiotic V and Chiralpal-AY3. Better resolution was obtained using a Chiralpak-AY3 column, utilizing as mobile phase ethanol (0.1% diethanolamine). An extraction procedure based on a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) was applied, using water and acetonitrile containing 1% of acetic acid, and a clean-up step utilizing primary secondary amine (PSA) and graphitized carbon black (GCB) as sorbents. The extract was diluted with ethanol (50/:50, v/v) prior to chromatographic analysis, and the separation was carried out avoiding the racemization during this stage. Enantiomerization process of atropine was studied in samples at different conditions such as temperature (30, 50 and 80°C) and pH (3, 5, 7 and 9), observing that racemization occurs at high pH (9) and temperature (80°C). Stramonium and Brugmansia seeds were analyzed and the concentration of (-)-hyoscyamine was 1500mg/kg and 320mg/kg respectively. Contaminated buckwheat was also determined and (-)-hyoscyamine was detected at 170µg/kg.

Accuracy for optical diagnosis of colorectal polyps in clinical practice.

BACKGROUND: Optical diagnostic involves predicting polyp histopathology from its endoscopic characteristics. It is only recommended for diminutive polyps ( < or = 5 mm) and for predictions made with high confidence. OBJECTIVES: To evaluate the accuracy of optical imaging in clinical practice and to assess if optical diagnosis is useful for predicting future colonoscopy surveillance intervals without waiting for histopathological analysis. METHODS: consecutive > 18 years patients were enrolled in this prospective study. Colonoscopies were performed by five expert endoscopists who previously participated in an ex-vivo training. Colonoscopes CF-H180AL and CF-Q180AL were used together with Exera II (Olympus Medical System, Tokyo, Japan) processors. Each polyp was characterized in real time using white light and Narrow Band Imaging. Accuracy of optical diagnosis (S, E, NPV, PPV) and correlation between surveillance interval based on optical diagnosis and histopathological analysis were calculated. RESULTS: 311 colon polyps < 10 mm (216 diminutive) in 195 patients were analyzed. Accuracy of optical diagnostics for predictions made with high confidence: Diminutive polyps(sensitivity 0.59, specificity 0.92, NPV 0.48); polyps < 10 mm (sensitivity 0.73, specificity 0.88, NPV 0.50). An optical diagnosis based surveillance recommendation was given to 90 patients. Concordance with histopathology based recommendation was 92.2% according to the European guideline and 93.3% according to the ESGE guideline. CONCLUSIONS: Optical diagnostics can be used to predict future surveillance intervals immediately after colonoscopy. However, in this study, based on clinical practice, the accuracy of optical imaging is below the recommended standards.

Relationship between tobacco, cagA and vacA i1 virulence factors and bacterial load in patients infected by Helicobacter pylori.

BACKGROUND AND AIM: Several biological and epidemiological studies support a relationship between smoking and Helicobacter pylori (H. pylori) to increase the risk of pathology. However, there have been few studies on the potential synergistic association between specific cagA and vacA virulence factors and smoking in patients infected by Helicobacter pylori. We studied the relationship between smoking and cagA, vacA i1 virulence factors and bacterial load in H. pylori infected patients. METHODS: Biopsies of the gastric corpus and antrum from 155 consecutive patients in whom there was clinical suspicion of infection by H. pylori were processed. In 106 patients H. pylori infection was detected. Molecular methods were used to quantify the number of microorganisms and presence of cagA and vacA i1 genes. A standardized questionnaire was used to obtain patients' clinical data and lifestyle variables, including tobacco and alcohol consumption. Adjusted Odds Ratios (ORadjusted) were estimated by unconditional logistic regression. RESULTS: cagA was significantly associated with active-smoking at endoscope: ORadjusted 4.52. Evidence of association was found for vacA i1 (ORadjusted 3.15). Bacterial load was higher in active-smokers, although these differences did not yield statistical significance (median of 262.2 versus 79.4 copies of H. pylori per cell). CONCLUSIONS: The association between smoking and a higher risk of being infected by a virulent bacterial population and with higher bacterial load, support a complex interaction between H. pylori infection and environmental factors.

Factors related to the effectiveness of variable stiffness colonoscope: results of a multivariate analysis.

BACKGROUND: Various studies and two meta-analysis have shown that a variable stiffness colonoscope improves cecal intubation rate. However, there are few studies on how this colonoscope should be used. OBJECTIVE: The aim of this study was to identify factors related to the advancement of the colonoscope when the variable stiffness function is activated. METHODS: Prospective study enrolling consecutive patients referred for colonoscopy. The variable stiffness colonoscope (Olympus CF-H180DI/L®) was used. We performed univariate and multivariate analyses of factors associated with the success of the variable stiffness function. RESULTS: After the data inclusion period, 260 patients were analyzed. The variable stiffness function was used most in the proximal colon segments (ascending and transverse colon 85%; descending/sigmoid colon 15.2%). The body mass index was lower in patients in whom the endoscope advanced after activating the variable stiffness than those in which it could not be advanced (25.9 + or - 4.8 vs. 28.3 + or - 5.4 kg/m2, p = 0.009). The endoscope advanced less frequently when the stiffness function was activated in the ascending colon versus activation in other segments of the colon (25% vs. 64.5% ascending colon vs. other segments; p < 0.05). In the multivariate analysis, only the colon segment in which the variable stiffness was activated was an independent predictor of advancement of the colonoscope. CONCLUSIONS: The variable stiffness function is effective, allowing the colonoscope advancement especially when applied in the transverse colon, descending colon and sigmoid. However, when used in the ascending colon it has a lower effectiveness.

Quantification of Helicobacter pylori in gastric mucosa by real-time polymerase chain reaction: comparison with traditional diagnostic methods.

The aim of this study was to determine the main diagnostic validity parameters of a quantitative real-time polymerase chain reaction (PCR) system for detecting Helicobacter pylori in gastric biopsies. Prospective study. The real-time PCR has an internal control for eliminating the false negatives. Our system has a good diagnostic capacity compared with the gold standard and was superior in antral mucosa: area under the curve was 0.91 for antrum (95% confidence interval [CI] 0.87 to 0.96) and 0.83 for corpus (95% CI 0.77 to 0.9). The optimum cut-off point was 3.56 microorganisms/cell for antrum (sensitivity 83.5% [95% CI 74.2 to 89.9]; specificity 91.3% [95% CI 82.3 to 96.0]; positive predictive value 92.2%; negative predictive value 81.8%). The positive likelihood ratios were 9.61 and 8.52 for antrum and corpus, respectively. With the cut-off point that maximises the Youden index, 8.7% false positives were obtained. Our methodology is useful for diagnosing infection due to H. pylori and the false positives detected probably correspond to patients who were actually infected but the infection was not detected by traditional techniques. The clinical importance of these cases should be studied in greater detail since they may involve colonisations unrelated to the patient's digestive pathology.

Real-time PCR for diagnosing Helicobacter pylori infection in patients with upper gastrointestinal bleeding: comparison with other classical diagnostic methods.

The aim of this study was to determine the diagnostic usefulness of quantification of the H. pylori genome in detection of infection in patients with upper gastrointestinal bleeding (UGB). A total of 158 consecutive patients with digestive disorders, 80 of whom had clinical presentation of UGB, were studied. The number of microorganisms was quantified using a real-time PCR system which amplifies the urease gene with an internal control for eliminating the false negatives. A biopsy sample from the antrum and corpus of each patient was processed. The rapid urease test, culture, histological study, stool antigen test, and breath test were done. The gold standard was a positive culture or positive results in at least two of the other techniques. When a positive result was defined as any number of microorganisms/human cell, the sensitivity of real-time PCR was greater in bleeding patients, especially in the gastric corpus: 68.4% (95% confidence interval [CI], 52.3 to 84.5%) in non-UGB patients versus 91.5% (95% CI, 79.6 to 97.6%) in UGB patients. When a positive result was defined as a number of microorganisms/human cell above the optimal value that maximizes the Youden index (>3.56 microorganisms/human cell in the antrum and >2.69 in the corpus), the sensitivity and specificity in UGB patients were over 80% in both antrum and corpus. Our findings suggest that some bleeding patients with infection caused by H. pylori may not be correctly diagnosed by classical methods, and such patients could benefit from the improved diagnosis provided by real-time PCR. However, the clinical significance of a small number of microorganisms in patients with negative results in classical tests should be evaluated.

Does the use of a variable stiffness colonoscope offer advantages during colonoscopy under deep sedation? Results of a randomized trial.

INTRODUCTION: Variable stiffness colonoscope may be useful in performing colonoscopies in nonsedated patients or under endoscopist-controlled sedation. The objective of this study is to evaluate whether this instrument facilitates colonoscopy in patients under deep sedation monitored by an anaesthesiologist. METHODS: Prospective and randomized study enroling consecutive patients referred for colonoscopy under deep sedation monitored by an anaesthesiologist. In group I, a variable stiffness colonoscope was used, whereas in group II, a standard colonoscope was used. The main variable was the need to change the position of the patient during the endoscopy. RESULTS: Fifty-six patients were included in group I (variable stiffness colonoscope) and 54 in group II (standard colonoscope). The caecum was reached in 92.9% of patients in group I and in 90.7% of group II (P=0.7). The time required to reach the caecum was significantly less in group I (6.14±3.5 vs. 7.7±3.8; P=0.035). The variable stiffness colonoscope was effective in 66.7% of cases. Changing the position of the patient was necessary in 12.5% of cases in group I compared with 33.3% of cases in group II (P=0.01). CONCLUSION: The variable stiffness colonoscope avoids the need to change the patient's position and reduces caecal intubation time in patients undergoing colonoscopy under deep sedation controlled by an anaesthesiologist.

Factors associated with non-attendance at outpatient endoscopy.

OBJECTIVE: Non-attendance at endoscopy procedures leads to wasted resources and increased costs. The purpose of this study was to investigate the factors associated with non-attendance. MATERIAL AND METHODS: All patients who attended the outpatient clinic for gastroscopy or colonoscopy examinations were included in the study. Patients who missed their appointment were identified and their data were collected prospectively. Patients who kept their appointment in the same period of time served as controls. RESULTS: Between August 2002 and February 2003, 1051 gastroscopies and 756 colonoscopies were scheduled. A total of 265 patients (14.7%) missed their appointment. No significant differences were found between attendees and non-attendees for mean age, gender, type of examination and day of the week on which the examination was scheduled. The time on the waiting list was longer in patients who did not keep their appointment than in those who did. Fewer appointments were missed in patients with a preferent referral, and among patients referred by their general practitioner a higher percentage failed to keep their appointment compared with those referred by a specialist. In the multivariate analysis, length of time on the waiting list and the source of referral were the only two independent predictive factors for non-attendance. CONCLUSIONS: A longer time on the waiting list and referral by a general practitioner are factors associated with patients failing to keep their endoscopy appointment.

Clinical value of rapid urine trypsinogen-2 test strip, urinary trypsinogen activation peptide, and serum and urinary activation peptide of carboxypeptidase B in acute pancreatitis.

AIM: To assess the usefulness of urinary trypsinogen-2 test strip, urinary trypsinogen activation peptide (TAP), and serum and urine concentrations of the activation peptide of carboxypeptidase B (CAPAP) in the diagnosis of acute pancreatitis. METHODS: Patients with acute abdominal pain and hospitalized within 24 h after the onset of symptoms were prospectively studied. Urinary trypsinogen-2 was considered positive when a clear blue line was observed (detection limit 50 microg/L). Urinary TAP was measured using a quantitative solid-phase ELISA, and serum and urinary CAPAP by a radioimmunoassay method. RESULTS: Acute abdominal pain was due to acute pancreatitis in 50 patients and turned out to be extrapancreatic in origin in 22 patients. Patients with acute pancreatitis showed significantly higher median levels of serum and urinary CAPAP levels, as well as amylase and lipase than extrapancreatic controls. Median TAP levels were similar in both groups. The urinary trypsinogen-2 test strip was positive in 68% of patients with acute pancreatitis and 13.6% in extrapancreatic controls (P<0.01). Urinary CAPAP was the most reliable test for the diagnosis of acute pancreatitis (sensitivity 66.7%, specificity 95.5%, positive and negative predictive values 96.6% and 56.7%, respectively), with a 14.6 positive likelihood ratio for a cut-off value of 2.32 nmol/L. CONCLUSION: In patients with acute abdominal pain, hospitalized within 24 h of symptom onset, CAPAP in serum and urine was a reliable diagnostic marker of acute pancreatitis. Urinary trypsinogen-2 test strip showed a clinical value similar to amylase and lipase. Urinary TAP was not a useful screening test for the diagnosis of acute pancreatitis.

A study of intestinal permeability in relation to the inflammatory response and plasma endocab IgM levels in patients with acute pancreatitis.

BACKGROUND: There is scarce information regarding intestinal permeability (IP) in patients with acute pancreatitis (AP) and its relationship with systemic inflammatory response and bacterial translocation (BT). AIMS: To study IP in patients with mild and severe forms of AP as compared with controls and the presumed correlations between IP, the inflammatory response, and endotoxin. PATIENTS AND METHODS: Sixty-eight patients with AP and 13 healthy controls were included. IP was assessed by means of the lactulose/mannitol (L/M) test, at admission (LMR1), and at the 15th day (LMR2). The presence of endotoxin was assessed by means of endotoxin-core antibodies type IgM (EndoCab IgM), at admission and 15 days later in patients with severe AP. Plasma levels of interleukins 6, 8, 10, and tumor necrosis factor alpha were tested within the first 72 hours from the onset of pain. RESULTS: Both LMR1 and LMR2 were significantly higher in patients than in controls, and in patients with severe versus mild forms of AP. Plasma levels of Endocab IgM increased significantly in patients with severe AP. Basal plasma levels of pro- and anti-inflammatory cytokines were significantly higher in patients with severe AP. A significant correlation was found between LMR2 and Endocab IgM levels in patients with severe AP (r = 0.73, P = 0.02). CONCLUSIONS: Patients with AP show an increased IP when compared with controls, being more relevant and persistent in severe cases. This seems related to an increase of endotoxemia late in the course of the disease, but not with an exacerbation of the systemic immune response.

Comparison of stool immunoassay with standard methods for detection of Helicobacter pylori infection in patients with upper-gastrointestinal bleeding of peptic origin.

OBJECTIVE: To assess the accuracy of the determination of Helicobacter pylori infection by a stool immunoassay in patients with upper-gastrointestinal bleeding (UGB) of peptic origin, in comparison with the routine histological study, serology, rapid urease and 13C-breath tests. METHODS: Sixty-eight patients with endoscopically proven UGB of peptic origin were included. The presence of H. pylori was considered when observed on histology or, if negative, by the positive indications of two of the remaining tests (serology, rapid urease,13C-breath test). The accuracy of stool immunoassay was estimated according to results obtained with other diagnostic methods. RESULTS: Lesions causing gastrointestinal bleeding were 49 duodenal ulcers, 11 gastric ulcers, six pyloric channel ulcers, 13 acute lesions of the gastric mucosa, and 16 erosive duodenitis. H. pylori infection was present in 59 (86.76%) patients. Forty-one patients had received nonsteroidal anti-inflammatory drugs. The sensitivity and specificity of the diagnostic methods were 47.5% and 100% for the rapid urease test, 93% and 87.5% for the breath test, 86.4% and 77.7% for serology, 89.4% and 100% for histology, and 96.6% and 33.3% for the stool test. CONCLUSIONS: The detection of H. pylori antigen in stools in patients with UGB of peptic origin has a good sensitivity (96.6%) but a low specificity (33.3%) for the diagnosis of H. pylori infection, which probably makes this test an inadequate tool in this setting if utilized alone.