Factors associated with lesion detection in colonoscopy among different indications

BACKGROUND AND OBJECTIVE

Different factors may influence colonoscopy performance measures. We aimed to analyze procedure- and endoscopist-related factors associated with detection of colorectal lesions and whether these factors have a similar influence in the context of different colonoscopy indications: positive fecal immunochemical test (+FIT) and post-polypectomy surveillance colonoscopies.

METHODS

This multicenter cross-sectional study included adults aged 40-80 years. Endoscopists (N = 96) who had performed ≥50 examinations were assessed for physician-related factors. Adenoma detection rate (ADR), adenomas per colonoscopy rate (APCR), advanced ADR, serrated polyp detection (SDR), and serrated polyps per colonoscopy rate (SPPCR) were calculated.

RESULTS

We included 12,932 procedures, with 4810 carried out after a positive FIT and 1967 for surveillance. Of the 96 endoscopists evaluated, 43.8% were women, and the mean age was 41.9 years. The ADR, advanced ADR, and SDR were 39.7%, 17.7%, and 12.8%, respectively. Adenoma detection rate was higher in colonoscopies after a +FIT (50.3%) with a more than doubled advanced ADR compared to non-FIT procedures (27.6% vs. 13.0%) and similar results in serrated lesions (14.7% vs. 13.5%). Among all the detection indicators analyzed, withdrawal time was the only factor independently related to improvement (p < 0.001). Regarding FIT-positive and surveillance procedures, for both indications, withdrawal time was also the only factor associated with a higher detection of adenomas and serrated polyps (p < 0.001). Endoscopist-related factors (i.e., weekly hours dedicated to endoscopy, annual colonoscopy volume and lifetime number of colonoscopies performed) had also impact on lesion detection (APCR, advanced ADR and SPPCR).

CONCLUSIONS

Withdrawal time was the factor most commonly associated with improved detection of colonic lesions globally and in endoscopies for + FIT and post-polypectomy surveillance. Physician-related factors may help to address strategies to support training and service provision. Our results can be used for establishing future benchmarking and quality improvement in different colonoscopy indications.

Bioinformatics approaches to the study of antimicrobial resistance

Detection and monitoring of antimicrobial resistance are two pillars on which clinical microbiology will be based in the coming decades. The implementation of certain technologies such as whole genome sequencing (WGS) or mass spectrometry and the creation of national and international databases that include and gather data on antimicrobial resistance from around the world has allowed the application of bioinformatics in the study of antimicrobial resistance in microorganisms involved in human pathology.

Clinical impact of rapid molecular detection of respiratory pathogens in patients with acute respiratory infection

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Diagnosis with FilmArray-RP was associated with changes in medical management.

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Accurate and rapid diagnosis decreased antibiotic use and complementary studies, and improved oseltamivir use.

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The multiplex PCR respiratory panel permitted a high viral detection rate not only in children but in adults.

Background

Acute respiratory infections (ARI) are a leading cause of morbidity and mortality worldwide. There is a need to demonstrate the clinical impact of using the new, rapid and sensitive molecular assays in prospectively designed studies.

Objectives

To study the impact on medical management of a rapid molecular assay in patients with respiratory infections.

Study design

A prospective, randomized, non-blinded study was performed in patients presenting to the Emergency Department during two respiratory seasons (2016–2017). Diagnosis was performed by FilmArray Respiratory Panel (FilmArray-RP) or by immunofluorescence assay (IFA).

Results

A total of 432 patients (156 children and 276 adults) were analyzed. Diagnosis with FilmArray-RP was associated with significant changes in medical management including withholding antibiotic prescriptions (OR:15.52, 95%CI:1.99–120.83 in adults and OR:12.23, 95%CI:1.56–96.09 in children), and reduction in complementary studies in children (OR:9.64, 95%CI:2.13–43.63) compared to IFA. Decrease in oseltamivir prescriptions was significantly higher in adults in the FilmArray-RP group (p = 0.042; OR:1.19, 95%CI:0.51-2.79) compared to adults managed with IFA. Diagnostic yield was significantly higher by FilmArray-RP (81%) than by IFA (31%)(p < 0.001). The median time from sample collection to reporting was 1 h 52 min by FilmArray-RP and 26 h by IFA (p < 0.001).

Conclusions

The high respiratory viruses’ detection rate and availability of results within two hours when using FilmArray-RP were associated with decreases in antibiotic prescriptions and complementary studies and more accurate use of oseltamivir.

A comparative study of the target volume definition in radiotherapy with «Slow CT Scan» vs. 4D PET/CT Scan in early stages non-small cell lung cancer

OBJECTIVES

To evaluate the use of 4D PET/CT to quantify tumor respiratory motion compared to the «Slow»-CT (CTs) in the radiotherapy planning process.

MATERIAL AND METHODS

A total of 25 patients with inoperable early stage non small cell lung cancer (NSCLC) were included in the study. Each patient was imaged with a CTs (4s/slice) and 4D PET/CT. The adequacy of each technique for respiratory motion capture was evaluated using the volume definition for each of the following: Internal target volume (ITV) 4D and ITVslow in relation with the volume defined by the encompassing volume of 4D PET/CT and CTs (ITVtotal). The maximum distance between the edges of the volume defined by each technique to that of the total volume was measured in orthogonal beam's eye view.

RESULTS

The ITV4D showed less differences in relation with the ITVtotal in both the cranio-caudal and the antero-posterior axis compared to the ITVslow. The maximum differences were 0.36mm in 4D PET/CTand 0.57mm in CTs in the antero-posterior axis. 4D PET/CT resulted in the definition of more accurate (ITV4D/ITVtotal 0.78 vs. ITVs/ITVtotal 0.63), and larger ITVs (19.9 cc vs. 16.3 cc) than those obtained with CTs.

CONCLUSION

Planning with 4D PET/CT in comparison with CTs, allows incorporating tumor respiratory motion and improving planning radiotherapy of patients in early stages of lung cancer.

Efficacy of a multifactorial strategy for bowel preparation in diabetic patients undergoing colonoscopy: a randomized trial

Background and study aims: Previous studies have reported that diabetes mellitus is an independent risk factor for inadequate bowel preparation. Current guidelines do not recommend a specific preparation for this patient population. The aims of this study were to assess the efficacy, safety, and tolerability of an adapted preparation protocol for colon cleansing in patients with type 2 diabetes mellitus. Patients and methods: This randomized, single-blind, parallel group, superiority trial compared a conventional bowel preparation protocol (CBP) with a diabetes-specific preparation protocol (DSP). The CBP included a low-fiber diet for 3 days followed by a clear liquid diet for 24 hours before colonoscopy. The DSP included a multifactorial strategy combining an educational intervention, a low-fiber diet, and adjustment of blood glucose-lowering agents. All patients received 4 L of a polyethylene glycol solution in a split-dose regimen. The endoscopists were blinded to the preparation protocol. The primary outcome measure was inadequate bowel preparation according to the Boston Bowel Preparation Scale. Secondary outcome measures included hypoglycemic events, tolerability, and acceptability. Results: A total of 150 patients were included in the study (74 CBP and 76 DSP). Both groups were comparable in terms of baseline characteristics. Inadequate bowel cleansing was more frequent following CBP than DSP (20 % vs. 7 %, P = 0.014; risk ratio 3.1, 95 % confidence interval 1.2 - 8). Only CBP and performance status were independently associated with inadequate bowel preparation. Both preparations were equally tolerated and accepted by patients, and side-effects were similar between the groups. Conclusions: A multifactorial strategy for bowel preparation in patients with diabetes undergoing colonoscopy showed a threefold reduction in the rate of inadequate bowel preparation, with no differences in safety and tolerability compared with conventional preparation.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02300779).

Folic acid enhances the apoptotic and genotoxic activity of carboplatin in HeLa cell line

In human tumor cells, experimental and clinical evidence indicates that some factors involved in signal transduction and cell growth can also modulate the response to chemotherapeutic treatment. The aim of the present study was to investigate the role of folic acid (FA) as a modulator of carboplatin (CBDCA) activity. Genotoxicity and cytotoxicity induced by CBDCA alone and in combination with FA were assessed in cultured HeLa cells. We used comet assay, mitotic index analysis, MTT and NR assays, cytokinesis-block micronucleus cytome assay and annexin V-IP as different cytotoxicity and genotoxicity approaches for human cervical carcinoma cell line studies. The results showed that addition of 900nM FA together with 40.4mM CBDCA enhanced the activity of the platinum compound, increasing its effect on cell death by nearly 20%, as evidenced by the MTT and NR assays. Moreover, not only higher levels of DNA and chromosomal damage were reached but also the number of necrotic and apoptotic cells were significantly increased when cell cultures were treated with the combined procedure. This situation opens the possibility to explore the use of FA in platinum-based chemotherapy protocols to reduce the platinum doses for patient treatment and decrease the chance of developing the known side effects without losing biological activity.

Outcome in obscure gastrointestinal bleeding after capsule endoscopy

AIM: To investigate the clinical impact of capsule endoscopy (CE) after an obscure gastrointestinal bleeding (OGIB) episode, focusing on diagnostic work-up, follow-up and predictive factors of rebleeding.

METHODS: Patients who were referred to Hospital del Mar (Barcelona, Spain) between 2007 and 2009 for OGIB who underwent a CE were retrospectively analyzed. Demographic data, current treatment with non-steroid anti-inflammtory drugs or anticoagulant drugs, hemoglobin levels, transfusion requirements, previous diagnostic tests for the bleeding episode, as well as CE findings (significant or non-significant), work-up and patient outcomes were analyzed from electronic charts. Variables were compared by χ² analysis and Student t test. Risk factors of rebleeding were assessed by Log-rank test, Kaplan-Meier curves and Cox regression model.

RESULTS: There were 105 patients [45.7% women, median age of 72 years old (interquartile range 56-79)] and a median follow-up of 326 d (interquartile range 123-641) included in this study. The overall diagnostic yield of CE was 58.1% (55.2% and 63.2%, for patients with occult OGIB and overt OGIB, respectively). In 73 patients (69.5%), OGIB was resolved. Multivariate analysis showed that hemoglobin levels lower than 8 g/dL at diagnosis [hazard ratios (HR) = 2.7, 95%CI: 1.9-6.3], patients aged 70 years and above (HR = 2.1, 95%CI: 1.2-6.1) and significant findings in CE (HR = 2.4, 95%CI: 1.1-5.8) were independent predictors of rebleeding.

CONCLUSION: One third of the patients presented with rebleeding after CE; risk factors were hemoglobin levels < 8 g/dL, age ≥ 70 years or the presence of significant lesions.

Interlaboratory comparison of dicentric chromosome assay using electronically transmitted images

The bottleneck in data acquisition during biological dosimetry based on a dicentric assay is the need to score dicentrics in a large number of lymphocytes. One way to increase the capacity of a given laboratory is to use the ability of skilled operators from other laboratories. This can be done using image analysis systems and distributing images all around the world. Two exercises were conducted to test the efficiency of such an approach involving 10 laboratories. During the first exercise (E1), the participant laboratories analysed the same images derived from cells exposed to 0.5 and 3 Gy; 100 images were sent to all participants for both doses. Whatever the dose, only about half of the cells were complete with well-spread metaphases suitable for analysis. A coefficient of variation (CV) on the standard deviation of ∼15 % was obtained for both doses. The trueness was better for 3 Gy (0.6 %) than for 0.5 Gy (37.8 %). The number of estimated doses classified as satisfactory according to the z-score was 3 at 0.5 Gy and 8 at 3 Gy for 10 dose estimations. In the second exercise, an emergency situation was tested, each laboratory was required to score a different set of 50 images in 2 d extracted from 500 downloaded images derived from cells exposed to 0.5 Gy. Then the remaining 450 images had to be scored within a week. Using 50 different images, the CV on the estimated doses (79.2 %) was not as good as in E1, probably associated to a lower number of cells analysed (50 vs. 100) or from the fact that laboratories analysed a different set of images. The trueness for the dose was better after scoring 500 cells (22.5 %) than after 50 cells (26.8 %). For the 10 dose estimations, the number of doses classified as satisfactory according to the z-score was 9, for both 50 and 500 cells. Overall, the results obtained support the feasibility of networking using electronically transmitted images. However, before its implementation some issues should be elucidated, such as the number and resolution of the images to be sent, and the harmonisation of the scoring criteria. Additionally, a global website able to be used for the different regional networks, like Share Points, will be desirable to facilitate worldwide communication.

Study of regulatory T-cells in patients with gastric malt lymphoma: influence on treatment response and outcome

Purpose

FOXP3+ regulatory T cells (Treg) play an essential role in modulating host responses to tumors and infections. The role of these cells in the pathogenesis of MALT lymphomas remains unknown. The aims of the study were to quantify the number of infiltrating FOXP3+ and CD3+ cells in patients with gastric MALT lymphoma at diagnosis and to study kinetics of these cells and CD20+ tumor cells after treatment and during long-term follow-up.

Methods

FOXP3+, CD3+ and CD20+ cells were analyzed by immunohistochemistry and the number of cells was quantified using a micrometric ocular. Samples of 35 patients with gastric MALT lymphoma at diagnosis and after treatment were included. Diagnostic samples were compared to 19 cases of chronic gastritis and diffuse large B-cell lymphoma (DLBCL) of the stomach.

Results

The median number of FOXP3+ infiltrating cells was higher (27 cells/cm²) in gastric MALT patients than in DLBCL (10 cells; p = 0.162) but similar to chronic gastritis (20 cells; p = 0.605). No characteristic or specific distribution pattern of infiltrating FOXP3+ cells was found. Gastric MALT lymphoma patients responding to bacterial eradication therapy had higher number of FOXP3+ cells at study entry. Kinetics of both infiltrating FOXP3+ cells and tumor CD20+ cells were strongly dependent on the treatment administered.

Discussion

Gastric MALT lymphomas have a number of Treg cells more similar to chronic gastritis than to DLBCL. Patients with higher number of tumor infiltrating FOXP3+ cells at study entry seem to have better response to antibiotics. Kinetics of Treg and tumor cells are influenced by type of treatment.

Effects of copper sulphate concentrations during in vitro maturation of bovine oocytes

THE OBJECTIVES WERE TO EVALUATE: 1) copper (Cu) concentrations in plasma and follicular fluid (FF) from cattle ovaries; 2) the effects of supplemental Cu during in vitro maturation (IVM) on DNA damage of cumulus cells and glutathione (GSH) content in oocytes and cumulus cells; and 3) supplementary Cu during IVM on subsequent embryo development. Copper concentrations in heifer plasma (116 ± 27.1 μg/dL Cu) were similar (P > 0.05) to concentrations in FF from large (90 ± 20.4 μg/dL Cu) and small (82 ± 22.1 μg/dL Cu) ovarian follicles in these heifers. The DNA damage in cumulus cells decreased with supplemental Cu concentrations of 4 and 6 μg/mL (P < 0.01) in the IVM medium (mean ± SEM index of DNA damage was: 200.0 ± 27.6, 127.6 ± 6.0, 46.4 ± 4.8, and 51.1 ± 6.0 for supplementation with 0, 2, 4, and 6 μg/mL Cu respectively). Total GSH concentrations increased following supplementation with 4 μg/mL Cu (4.7 ± 0.4 pmol in oocytes and 0.4 ± 0.04 nmol/10(6) cumulus cells) and 6 μg/mL Cu (5.0 ± 0.5 pmol in oocytes and 0.5 ± 0.05 nmol/10(6) cumulus cells, P < 0.01) compared with the other classes. Cleavage rates were similar (P ≥ 0.05) when Cu was added to the IVM medium at any concentration (65.1 ± 2.0, 66.6 ± 1.6, 72.0 ± 2.1, and 70.7 ± 2.1 for Cu concentrations of 0, 2, 4, and 6 μg/mL). Percentages of matured oocytes that developed to the blastocyst stage were 18.7 ± 0.6, 26.4 ± 0.03, and 29.0 ± 1.7% for 0, 2, and 4 μg/mL Cu, and was highest (33.2 ± 1.6 %) in oocytes matured with 6 μg/mL Cu (P > 0.01). There was an increase (P > 0.05) in mean cell number per blastocyst obtained from oocytes matured with 4 and 6 μg/mL Cu relative to 0 Cu (IVM alone) and 2 μg/mL Cu. In conclusion, Cu concentrations in the FF and plasma of heifers were similar. Adding copper during oocyte maturation significantly increased both intracellular GSH content and DNA integrity of cumulus cells. Since embryo development was responsive to copper supplementation, we inferred that optimal embryo development to the blastocyst stage was partially dependent on the presence of adequate Cu concentrations during IVM.

Biological dosimetry intercomparison exercise: an evaluation of triage and routine mode results by robust methods

Well-defined protocols and quality management standards are indispensable for biological dosimetry laboratories. Participation in periodic proficiency testing by interlaboratory comparisons is also required. This harmonization is essential if a cooperative network is used to respond to a mass casualty event. Here we present an international intercomparison based on dicentric chromosome analysis for dose assessment performed in the framework of the IAEA Regional Latin American RLA/9/054 Project. The exercise involved 14 laboratories, 8 from Latin America and 6 from Europe. The performance of each laboratory and the reproducibility of the exercise were evaluated using robust methods described in ISO standards. The study was based on the analysis of slides from samples irradiated with 0.75 (DI) and 2.5 Gy (DII). Laboratories were required to score the frequency of dicentrics and convert them to estimated doses, using their own dose-effect curves, after the analysis of 50 or 100 cells (triage mode) and after conventional scoring of 500 cells or 100 dicentrics. In the conntional scoring, at both doses, all reported frequencies were considered as satisfactory, and two reported doses were considered as questionable. The analysis of the data dispersion among the dicentric frequencies and among doses indicated a better reproducibility for estimated doses (15.6% for DI and 8.8% for DII) than for frequencies (24.4% for DI and 11.4% for DII), expressed by the coefficient of variation. In the two triage modes, although robust analysis classified some reported frequencies or doses as unsatisfactory or questionable, all estimated doses were in agreement with the accepted error of ±0.5 Gy. However, at the DI dose and for 50 scored cells, 5 out of the 14 reported confidence intervals that included zero dose and could be interpreted as false negatives. This improved with 100 cells, where only one confidence interval included zero dose. At the DII dose, all estimations fell within ±0.5 Gy of the reference dose interval. The results obtained in this triage exercise indicated that it is better to report doses than frequencies. Overall, in both triage and conventional scoring modes, the laboratory performances were satisfactory for mutual cooperation purposes. These data reinforce the view that collaborative networking in the case of a mass casualty event can be successful.

Effect of increasing zinc sulphate concentration during in vitro maturation of bovine oocytes

The objective was to investigate the effects of supplementary zinc (Zn) during in vitro maturation (IVM) of bovine oocytes. The DNA damage in cumulus cells was low with supplemental Zn concentrations of 1.1 and 1.5 μg/mL in the IVM medium (mean ± SEM index of DNA damage was 67.52 ± 9.32, 68.52 ± 13.34, 33.80 ± 4.89, and 34.65 ± 7.92 for supplementation with 0, 0.7, 1.1, and 1.5 μg/mL Zn, respectively; P < 0.01). Total glutathione concentrations did not differ following Zn supplementation of 1.1 and 1.5 μg/mL (3.7 ± 0.4 vs. 4.0 ± 0.5 pmol, respectively, in oocytes; and in cumulus cells, 0.5 ± 0.04 nmol/10(6) cells, combined for both treatments), but were greater (P < 0.01) than supplementation with 0.7 μg/mL (1.8 ± 0.5 pmol in oocytes and 0.2 ± 0.02 nmol/10(6) cumulus cells). Cleavage rate increased (P < 0.05) when Zn was added to the IVM medium at any concentration (67.16 ± 1.17, 73.15 ± 1.15, 74.05 ± 1.23, and 72.76 ± 0.74 for 0, 0.7, 1.1, and 1.5 μg/mL Zn). For these concentrations, subsequent embryo development to the blastocyst stage was 17.83 ± 2.15, 21.95 ± 0.95, 27.65 ± 1.61, and 30.33 ± 2.78%, highest (P < 0.01) in oocytes matured with 1.5 μg/mL Zn. There was an increase (P < 0.05) in mean cell number per blastocyst obtained from oocytes matured with 1.1 and 1.5 μg/mL Zn relative to 0 Zn (IVM alone) and 0.7 μg/mL Zn. In conclusion, Zn during oocytes maturation significantly affected intracellular GSH content and DNA integrity of cumulus cells, and improved preimplantational embryo development. We inferred that optimal embryo development to the blastocyst stage was partially dependent on the presence of adequate Zn concentrations.

Genetic instability induced by low doses of x-rays in hamster cells

PURPOSE

Genomic instability involves time delayed events and can be manifested as elevated rates of heritable changes in the progeny of irradiated cells. To study the induction of chromosomal instability by very low doses of radiation Chinese Hamster Ovary (CHO) cells were exposed to 10-50 milisieverts (mSv) (approximately 10-50 miligrays (mGy)) of x-rays.

MATERIALS AND METHODS

Control and irradiated cell populations were assayed for chromosomal aberrations and assessed using a micronucleus test and anaphase-telophase analysis at the first cell division post-irradiation and at every four population doublings thereafter up to 16 population doublings post-irradiation.

RESULTS

Frequencies of micronuclei, anaphase-telophase alterations and chromosomal aberrations were increased when the cells were analysed immediately after x-ray exposure. Micronuclei and anaphase-telophase alterations showed significantly increased frequencies when they were analysed at 12 and 16 population doublings after exposure to 50 mSv. Chromosomal aberrations increased significantly at 12 and 16 population doublings after exposure to 10 mSv and 50 mSv.

CONCLUSIONS

Our results are consistent with the presence of a phenomenon by which the initial DNA damage in the surviving cells is memorized. Micronuclei and achromatic lessions were the main cytogenetic damage observed in cells exposed to very low doses of x-rays, indicating that these low doses are able to induce genetic instability.

Cytogenetic analysis in Chinese hamster cells chronically exposed to low doses of X‐rays

PURPOSE

It is important to develop simple experimental models to assess the induction of DNA damage and study the different factors involved under controlled conditions. This paper describes the cytogenetic analysis carried out in Chinese hamster cells (CHO) sequentially exposed to very low doses of X-rays.

MATERIALS AND METHODS

CHO cells were cultured for 14 passages. Irradiation treatment was performed once per passage, and three irradiation doses were employed: 2.5, 5.0 and 10.0 mSv.

RESULTS

Sequential irradiation of CHO cells did not increase the yield of chomatid- or chromosome-type aberrations. However, a significant increase of achromatic lesions (gaps) was found after the first or second X-ray dose, with all three irradiation doses employed.

CONCLUSIONS

The variation in the frequency of gaps as well as that in the mitotic index during the 14 cycles of radiation could be an indication of the induction of genomic instability. According to this, continuous rises and falls in the frequency of gaps as well as in the mitotic index reflects the simultaneous induction of endogenous DNA damage, cell death and cell survival.

Variation among endoscopy units in the achievement of the standards of colonoscopic performance indicators

BACKGROUND/AIMS

To assess the achievement of quality standards of colonoscopy at six endoscopy units.

METHODOLOGY

Three indicators were used to assess the quality of 1056 colonoscopies performed at six hospitals: cecal intubation; adequate colon cleansing; and removal and recovery of all detected polyps. Analyses were performed on the total number of colonoscopies and on colonoscopies in which polyps were actually detected. The accomplishment of each indicator and a global compound index of all three indicators, named the Problem Rate, were analyzed. Results from each endoscopy unit were compared to previously established standards.

RESULTS

Adequate colon cleansing was the most frequent problem for quality in all centers; adequate colon preparation was 67% (range 50 to 84%). The cecum was reached in 84% of all colonoscopies (range 76 to 90%). 75% of all patients (range 28. 79%) had all polyps excised and recovered. All centers had rates below standard for one or several indicators (p<0.01, all cases). Two of the participant hospitals had an overall problem rate above the estimated standard (p<0.01).

CONCLUSIONS

There is a significant variation in the achievement of quality standards of colonoscopy between endoscopy units. Colon cleansing is the most frequent quality problem for colonoscopy.

Role of Helicobacter pylori in stomach cancer after partial gastrectomy for benign ulcer disease

OBJECTIVE

To determine the prevalence of Helicobacter pylori infection in patients having undergone gastrectomy for non-neoplastic disease who later developed gastric stump cancer.

MATERIAL AND METHODS

Retrospective study of all patients with partial gastrectomy for non-malignant peptic disease who were submitted to an endoscopic exploration between 1995 and 2001. A comparison was made of major clinical and histological characteristics, and the presence of Helicobacter pylori among patients with and without gastric cancer in the stomach remnant.

RESULTS

A total of 73 patients were studied in this period. Fifteen patients (20.5%) had remnant-stump gastric cancer. All but one were adenocarcinomas (71% intestinal and 29% diffuse, respectively). The average time between diagnosis of gastric cancer and previous gastrectomy was 32 (14-48) years. There was a higher detection rate of Helicobacter pylori in patients with cancer in the gastric remnant (100 vs. 81.5%, respectively, p < 0.07). No relationship was seen between type of gastric reconstruction (Billroth I or II) and rate of Helicobacter pylori detection.

CONCLUSIONS

Helicobacter pylori infection is frequent in patients with previous gastrectomy for non-neoplastic disease. The results of the study suggest that Helicobacter pylori infection may play a role in gastric stump cancer.

Applicability of the Rockall score in patients undergoing endoscopic therapy for upper gastrointestinal bleeding

BACKGROUND

The Rockall score is used to assess the prognosis of patients with upper gastrointestinal bleeding.

AIM

To assess the applicability of the Rockall score in patients undergoing endoscopic therapy for upper gastrointestinal bleeding.

METHODS

Retrospective evaluation of the Rockall score in the period 1995-2001. To evaluate the applicability of the Rockall system, two groups were created: group I (Rockall<or=5 points) and group II (Rockall>or=6 points).

RESULTS

Two hundred and twenty-two patients were included. The median age of patients was 65 +/ -17 years. Hypotension and associated diseases were present in 20 and 50% of patients, respectively. Re-bleeding occurred in 50 patients (23%) whose median score was 7, whereas the median score of patients without re-bleeding was 6 (p=0.14). There were 20 deaths (9%) with a median score of 8, whilst the median score of surviving patients was 6 (p<0.001). Sixteen patients in group I (18.4%) and 34 in group II (25.2%) re-bled (p=0.25). All the patients who died belong to group II with a Rockall score>or=6 (15% versus 0% in groups II and I, respectively, p<0.001).

CONCLUSION

The Rockall score can be used in patients who undergo therapeutic endoscopy for upper gastrointestinal bleeding to identify those with high risk for mortality.

Differential effects oftrans-crotononitrile and 3-acetylpyridine on inferior olive integrity and behavioural performance in the rat

The inferior olive climbing fibre projection is key to cerebellar contributions to motor control. Here we present evidence for a novel tool, trans-crotononitrile (TCN), to selectively inactivate the olive to study its functions. Anatomical, electrophysiological and behavioural techniques have been used in rats to assess the CNS effects of TCN, with a focus on the olivocerebellar projection. These findings were compared with those obtained with 3-acetylpyridine (plus nicotinamide administered 3.5 h later, 3AP + 3.5 h). Fluoro-Jade B cell labelling showed that TCN and 3AP + 3.5 h induce neurodegeneration primarily within the inferior olive, with no other targets in common. Recordings of evoked field potentials on the cerebellar cortical surface showed that both neurotoxins can reduce transmission in climbing fibre but not mossy fibre pathways. Both histological and electrophysiological differences suggest that TCN and 3AP have distinct mechanisms of action. Estimates of the numbers of surviving cells within individual subdivisions of the olive indicate that TCN and 3AP + 3.5 h cause different patterns of subtotal olivary lesion: most surviving neurons are present in the rostral (TCN) or caudal (3AP + 3.5 h) parts of the medial accessory olive, which are associated with two different cerebellar modules: the C2 and A modules, respectively. In behavioural studies, TCN and 3AP + 3.5 h produced differences in motor deficits consistent with the notion that these cerebellar modules have distinct functional responsibilities. Thus, studies using TCN as compared with 3AP + 3.5 h have the potential to shed light on the contributions of different cerebellar modules in motor control.

[Helicobacter pylori and gastric cancer: relationship with histological subtype and tumor location]

INTRODUCTION

Helicobacter pylori (HP) has been implicated in the pathogenesis of gastric adenocarcinoma. Published data on HP infection and its association with both histological subtype and tumor localization are contradictory and few data are available on this topic in Spain. The aim of the present study was to evaluate the association of HP infection with histological subtype and tumor localization in a series of patients with gastric adenocarcinoma.

MATERIAL AND METHOD

We retrospectively reviewed all the patients diagnosed with gastric neoplasms in Hospital del Mar in Barcelona between 1995 and 2001. The histological subtype was established using Lauren's classification. Tissue samples were obtained from the surgical specimen or from endoscopic biopsies. HP infection was histologically determined through hematoxylin-eosin, Masson's trichromic, and Giemsa staining.

RESULTS

During the study period, 304 gastric neoplasms, 275 (90.4%) adenocarcinomas, 22 (7.2%) lymphomas, 3 (1.0%) leiomyosarcomas, 2 (0.7%) degenerated gastrointestinal stromal tumors (GIST) and 2 (0.7%) Kaposi's sarcomas were diagnosed. In patients with adenocarcinoma, the mean age at diagnosis was 69 years and most patients were male (62%). A total of 48.1% of the neoplasms were located in the gastric antrum, 23.7% in the body and 19.1% in the fundus (13.6% in the period 1994-1997 and 25.4% in the period 1998-2001, p = 0.018). Intestinal-type gastric carcinoma was observed in 56% of the patients, diffuse-type in 28% and indeterminate-type in 16%. HP infection was confirmed in 69% of the patients (68% in intestinal subtype, 69% in diffuse subtype, and 69% in indeterminate subtype, p = 0.84), and was significantly associated with distal adenocarcinomas vs. proximal adenocarcinomas (73.6% vs 48.6%, p < 0.05).

CONCLUSIONS

No differences were observed between the histological type of adenocarcinoma and HP infection. In the last few years, the incidence of fundic adenocarcinomas has increased. These tumors show a lower association with HP infection.

Relationship between insult intensity and mode of hair cell loss in the vestibular system of rats exposed to 3,3'-iminodipropionitrile

A variety of stimuli cause sensory hair cell loss in the mammalian inner ear. This loss occurs by several differing processes, the significance of which remains undetermined. This study examines the relationship between the intensity of the damaging stimulus and the mode of hair cell loss found in the vestibular sensory epithelia of the rat. The ototoxin 3,3'-iminodipropionitrile (IDPN) was administered to rats at three different intoxication rates: acute exposure to high doses, repeated exposure to intermediate doses, and subchronic exposure to low doses. The morphology of the vestibular epithelia was examined by light microscopy and by scanning and transmission electron microscopy (SEM and TEM). In addition, DNA fragmentation in the epithelia was assessed by terminal deoxynucleotidyl transferase (tdt)-dUTP-nick-end-label (TUNEL). One day after acute IDPN, necrosis of hair cells was observed. However, at day 4 with this dose, and 1 and 4 days after repeated exposure, apoptotic figures and positive TUNEL labeling predominated. Subchronic IDPN resulted in a slowly evolving extrusion of basically intact hair cells in the crista and utricle. The data demonstrate that extrusion is a major mechanism of hair cell demise in mammals, that necrosis, apoptosis, and extrusion form a continuum of modes of hair cell loss, and that the intensity of the damaging stimulus determines the prevalence of each mode: Necrosis was most evident when the intensity was at its highest, whereas extrusion predominated when the intensity was at the lowest end of the scale.

Pathology of the rat vestibular sensory epithelia during subchronic 3,3'-iminodipropionitrile exposure: hair cells may not be the primary target of toxicity

3,3'-Iminodipropionitrile (IDPN) is a neurotoxic compound that causes proximal neurofilamentous axonopathy and loss of the vestibular sensory hair cells. During subchronic exposure, the hair cells are eliminated by extrusion of the virtually intact cell from the sensory epithelia towards the luminal cavity. We describe the alterations of the vestibular epithelia before and during hair cell extrusion. Adult male Long-Evans rats were exposed to 0.2% IDPN in the drinking water for 1, 3, 5, 8 or 14 weeks, or to 0.1% IDPN for 14 weeks. Protrusion and subsequent extrusion of hair cells were observed in the cristae and utricular maculae of rats exposed to 0.2% IDPN for at least 5 weeks. At earlier time points and at lower doses, we observed the following pathological signs: blebbing of hair cells, swelling, retraction and fragmentation of the afferent nerve terminals, detachment of hair cells from the surrounding structures and loss of the pre- and post-synaptic membrane thickenings between hair cells and their afferent terminals. Widespread enlargement of the intercellular spaces also preceded and accompanied the extrusion process. The present data challenge the hypothesis that IDPN specifically affects hair cells.

Efferent function of vestibular afferent endings? Similar localization of N-type calcium channels, synaptic vesicle and synaptic membrane-associated proteins

We investigated the distribution of N-type voltage-dependent calcium channels that mediate Ca(2+) entry initiating transmitter release in the rat vestibular sensory epithelium. We used confocal microscopy to assess the in vitro labeling by fluorescent specific ligand binding, omega-conotoxin-GVIA and also the immunolabeling of presynaptic soluble N-ethylmaleimide-sensitive fusion factor attachment protein receptor (SNARE) proteins, syntaxin, 25,000 mol. wt synaptosome-associated protein and synaptotagmin: components of the neurotransmitter exocytosis machinery. We found that there was a close anatomical association between the voltage-gated calcium channels, the synaptic vesicle and synaptic membrane-associated proteins on the afferent nerve calyces and probably afferent boutons, which are postsynaptic compartments. Our data suggest that these peripheral afferent endings possess the presynaptic Ca(2+) channels and the components of the presynaptic SNARE proteins involved in synaptic vesicle docking and calcium-dependent exocytosis. They provide additional evidence for a secretory function and efferent role of these endings in hair cell neurotransmission.

Aneugenic effects of some metal compounds assessed by chromosome counting in MRC-5 human cells

Development of a comprehensive test battery is necesary for the evaluation and detection of aneugenic chemicals. The chromosome couting method was used in the present study. The aneugenic ability of cadmium choride (1.0, 2.0 and 4.0x10(-3) mM), cadmium sulfate (3. 3, 6.7x10(-5) and 1.3x10(-4) mM), potassium dichromate (2.5, 5. 0x10(-4) and 1.0x10(-3) mM) and cacodilic acid (1.25, 2.5 and 5. 0x10(-2) mM) were analysed using MRC-5 cells which have a modal diploid number of 2 n=46 with a spontaneous aneuploid or polyploid cells not higher than 13% and 8%, respectively.All compounds induced significant increments of aneuploid cells in relation to negative controls. The frequency of aneuploid cells increased in all treatments with cadmium chloride. Cadmium sulfate induced significant increments of aneuploid cells with the two higher doses. All the doses of potassium dichromate increased the frequency of aneuploid cells although to a lesser degree than the other compounds. In these cases, differences were in the borderline of statistical significance (p<0.05). Moreover, a low number of cells could be analysed in treatments with the highest dose due to the decrease in the mitotic index. Results obtained are coincident with previous reports using the same methodology in the sense that induced aneuploidy was mainly evidenced by the increase of hypodiploid but not hyperdiploid cells. In addition, anaphase-telophase analysis of the effects of the same doses of these metal compounds in CHO cells showed significant increments of lagging chromosomes and increased frequencies of kinetochore positive micronuclei in MRC-5 cells. These findings could be considered as an indication that the main cause of unequal chromosome separation is the failure of kinetochores to attach the spindle apparatus either by alteration of its protein components or by the altered chromatid separation in anaphase.

Identification of a streptogramin A acetyltransferase gene in the chromosome of Yersinia enterocolitica

Streptogramins are polypeptide antibiotics inhibiting protein synthesis by the prokaryotic ribosome. Gram-positive organisms are susceptible to streptogramins, while most gram-negative bacteria are intrinsically resistant. We have found a genomic fragment from a Yersinia enterocolitica isolate with an open reading frame coding for a polypeptide similar to the virginiamycin acetyltransferases found in various plasmids from gram-positive bacteria. The susceptible Escherichia coli strain DB10 was transformed to resistance to the type A streptogramins and to mixed (A + B) streptogramins upon introduction of a plasmid containing that gene. In addition, we showed streptogramin acetylating activity in vitro dependent on the presence of the Y. enterocolitica sat gene. Southern blot hybridization experiments showed that the sat gene was present in all the Y. enterocolitica isolates examined. These data together show that the gene in the Y. enterocolitica chromosome encoded an active streptogramin acetyltransferase. The deduced sequence of the Y. enterocolitica Sat protein was close to those of sat gene products found in gram-positive bacteria and cyanobacteria, suggesting a common evolutionary origin.

[Anti-A antibodies and bacterial contamination of platelet concentrates]

OBJECTIVES

The possible ABO group antibodies protective function against several infections has been classically described. We analyze the platelet concentrates (PC) bacterial control results and their ABO antibodies.

MATERIAL AND METHODS

We studied 245 outdated PCs (> 5 days). The samples were sterilely collected for adequate microbiological investigation studies on sheep-blood agar plates. If bacterial growth is found, the microbiological identification is performed on the basis of standard tests, the specific anti-biotype being achieved by disk-diffusion method on Müeller-Hinton agar plates, and the red cell concentrate was analyzed.

RESULTS

Bacterial growth by negative coagulase Staphylococcus was found in 10 PCs (4.1%; CI95%; 1.97-7.37). The contaminated PCs lacked natural anti-A antibodies. There were no statistical differences when we analyzed the PC's age, colour or blood group.

COMMENTS

The anti-A antibodies may be a protective factor versus PCs contamination caused by resident bacteria.

[UTIscreen versus UROQUICK: two semiautomatic systems for bacteriuria detection]

BACKGROUND

The aim of the study is to find a rapid and reliable method for urine screen. With this purpose two semiautomatic systems have been evaluated: UTIscreen and UROQUICK.

MATERIAL AND METHODS

We have carried out a prospective study of a total 1,070 urine specimens from patients with suspected urinary infection. Each sample has been inoculated in the two semiautomatic systems and compared with the semiquantitative plate culture as the reference method.

RESULTS

Both semiautomatic systems showed similar specificity and sensitivity at an interpretative breakpoint of 30,000 CFU/ml, with a low number of false positives. Uninfected specimens can be reported the same day of reception.

CONCLUSIONS

Both UTIscreen and UROQUICK systems seem to be adequate for urinary tract infection screening. They are reliable and easy to perform, but in our particular case we find advantage in using UTIscreen because the faster reading of this system makes posible to report the negative results in the same morning of reception of the specimen and do the culture of all the positive samples during our usual working schedule.

Degeneration and gliosis in rat retina and central nervous system following 3,3'-iminodipropionitrile exposure

3,3'-Iminodipropionitrile (IDPN) exposure causes a neurofilamentous axonopathy and olfactory, audiovestibular and visual toxicity. Many events relevant to these effects and the neurotoxic properties of nitriles as a class remain to be elucidated. We characterized the gliosis associated with the IDPN-induced retinal degeneration in comparison to other effects on the visual and central nervous systems. Gliosis was quantified using an ELISA for the intermediate filament protein, glial fibrillary acidic protein (GFAP). IDPN (0-400 mg kg-1 day-1x3 days, i.p.) caused corneal opacity and dose- and time-dependent increases in retinal GFAP, up to 26-28 fold of control values at 4 weeks post-exposure; a second peak occurred at 16 weeks. In contrast, GFAP peaked at 1 week in olfactory bulbs (OB), cingulate cortex and hippocampus. Cerebellum and striatum showed no gliosis. Retinal dopamine decreased within 2 weeks. Delayed GFAP increases occurred in superior and inferior colliculi. Retina and superior colliculi also showed increased [3H]PK-11195 binding. Histological analysis demonstrated progressive degeneration and gliosis in retina and colliculi. Taken together, the data indicate that primary and secondary degenerative events occur in the retina, and that this retinal degeneration induces GFAP increases in retina and superior colliculus. In addition, GFAP assays demonstrated that the retinal toxicity of IDPN is enhanced by CCl4 hepatotoxicity and blocked by methimazole inhibition of flavin-mono-oxygenases, similarly to its ototoxicity. GFAP assays also indicated that neither vestibulotoxic doses of crotononitrile nor olfatotoxic doses of dichlobenil damage the retina. The data support the use of GFAP assays for assessing the retinal toxicity of IDPN and other nitriles.

[Incidence of Cryptosporidium in Zaragoza: an 8-year study (1989-1996)]

BACKGROUND

To study the incidence of Cryptosporidium infections over an eight year period in an urban area, together with the patients background and the season of the year.

MATERIALS AND METHODS

From January 1989 to December 1996, all 32,733 stool samples from 13,639 patients: children and immunocompromised adults, with presumed infective diarrhoea, were investigated for Cryptosporidium oocysts by the Department of Microbiology, Miguel Servet Hospital, Zaragoza (Spain).

RESULTS

Cryptosporidial infection was identified in a 3% of the total children, been the positivity rate highest in the 2-year old group. We visualized oocysts in the 8% of the immunocompromised patients, all of them HIV-positive. The prevalence was higher in winter (February-March).

CONCLUSIONS

According to these findings we conclude that Cryptosporidium should be systematically searched by clinical laboratories, specially in children and in immunocompromised patients suffering from infectious diarrhoea.

[Resection of hepatic colorectal metastases]

Between October 1986 and March 1995, 35 patients had hepatic resections because of metastases of colorectal cancer: 24 (68.6%) metastasectomies were carried out and 11 formal resections. The surgical morbility was 34.3% (12/35 patients) and the mortality 5.7% (2/35 patients). The medium hospitalization was 13.1 days (range: 6-68). The medium follow up of our population was 30.3 months. From the 33 evaluable patients (2 out of the 35 patients were discarded from the analysis for intraoperatory death) 21 relapsed. The medium disease free survival was 18.9 months; 19/33 patients died (all from progressive disease). The medium survival for the 33 patients was 26.6 months. The 5 years survival was 42.4%, comparable with other international series. We consider that factors related with the strict selection of the patients contributed to achieve these encouraging results. The multidisciplinary work (that made easier the selection of the better candidates for surgery) involving surgeons, anesthesiologists, oncologists, radiologists and internists, were made possible in a public hospital.