[Procedural skills training in a developing country: 10 tips]. / Vaardigheidstraining in ontwikkelingslanden: 10 tips.

Procedural skills training in a developing country is challenging, but can improve the quality of care for patients with an important regional health problem. A structured, brief, teach-the-teacher-based training course supports physicians in developing countries to acquire skills needed to perform a complex procedure independently. A case of a patient diagnosed with esophageal cancer is presented and 10 tips are given for training procedural skills in a developing country.

Effectiveness of endosponge therapy for the management of presacral abscesses following rectal surgery.

BACKGROUND: Anastomotic leak after rectal surgery is reported in 9% (range 3-28%) of patients. The aim of our study was to evaluate the effectiveness of endosponge therapy for anastomotic. Endpoints were the rate of restored continuity and the functional bowel outcome after anastomotic leakage. METHODS: This was a multicenter retrospective observational cohort study. All patients with symptomatic anastomotic leakage after rectal surgery who had endosponge therapy between January 2012 and August 2017 were included. Functional bowel outcome was measured using the low anterior resection syndrome (LARS) score system. RESULTS: Twenty patients were included. Eighteen patients had low anterior resection (90%) for rectal cancer. A diverting ileostomy was performed at primary surgical intervention in 14 patients (70%). Fourteen patients (70%) were treated with neoadjuvant (chemo-)radiotherapy. The median time between primary surgical intervention and first endosponge placement was 21 (5-537) days. The median number of endosponge changes was 9 (2-28). The success rate of the endosponge treatment was 88% and the restored gastrointestinal continuity rate was 73%. A chronic sinus occurred in three patients (15%). All patients developed LARS, of which 77% reported major LARS. CONCLUSIONS: Endosponge therapy is an effective treatment for the closure of presacral cavities with high success rate and leading to restored gastrointestinal continuity in 73%. However, despite endosponge therapy many patients develop major LARS.

Quality colonoscopy and risk of interval cancer in Lynch syndrome.

PURPOSE: Despite colonoscopic surveillance, Lynch syndrome patients develop colorectal cancer (CRC). Identification of modifiable factors has the potential to improve outcome of surveillance. The aims of this study were to determine (1) characteristics of patients with CRC, (2) endoscopic and histological features of these cancers, and (3) quality of the previous colonoscopy. METHODS: Approximately 2,200 medical reports from proven and obligate mutation carriers identified at the Dutch Lynch Syndrome Registry and two large hospitals were retrospectively analyzed for the presence of an interval cancer defined as CRC diagnosed within 24 months of previous colonoscopy. RESULTS: Thirty-one interval cancers were detected in 29 patients (median age of 52 [range 35-73]), after a median time of 17 months. All were MLH1 or MSH2 mutation carriers, and 39 % had a previous CRC. In patients without previous surgery for CRC, 84 % was proximally located. Of all interval cancers, 77 % were at local stage (T1-3N0Mx). In three patients (9 %) with an incomplete previous colonoscopy, CRC was located in the unexamined colon. In six of the nine patients with an adenoma during previous colonoscopy, the cancer was detected in the same colonic segment as the previously removed adenoma. CONCLUSIONS: Interval cancers were detected in MLH1 and MSH2 mutation carriers, especially in those with a history of previous CRC and between 40 and 60 years. Interval cancer could be related to incompleteness of previous endoscopy and possibly residual adenomatous tissue. Further reduction of the interval cancer risk may be achieved by optimizing endoscopy quality and individualization of surveillance guidelines.

Microscopic colitis: an unfamiliar but treatable disease.

Chronic diarrhoea is a frequent complaint in clinical practice. Microscopic colitis is the cause of this symptom in 10% of these cases and the prevalence is rising. To exclude microscopic colitis a colonoscopy with multiple biopsies of different regions of the colon is mandatory. A sigmoidoscopy alone is insufficient. Two histopathological types of microscopic colitis can be distinguished: collagenous colitis and lymphocytic colitis. Nowadays, there is sufficient evidence to recommend budesonide as the first-choice treatment. Bismuth can also be recommended, but this drug is not easily available in the Netherlands. Evidence of efficacy of other drugs is scant.

Quantification of electrical field-induced flow reversal in a microchannel.

We characterize the electroosmotic flow in a microchannel with field effect flow control. High resolution measurements of the flow velocity, performed by micro particle image velocimetry, evidence the flow reversal induced by a local modification of the surface charge due to the presence of the gate. The shape of the microchannel cross-section is accurately extracted from these measurements. Experimental velocity profiles show a quantitative agreement with numerical results accounting for this exact shape. Analytical predictions assuming a rectangular cross-section are found to give a reasonable estimate of the velocity far enough from the walls.

Directional flow induced by synchronized longitudinal and zeta-potential controlling AC-electrical fields.

Electroosmotic flow (EOF) in a microchannel can be controlled by electronic control of the surface charge using an electrode embedded in the wall of the channel. By setting a voltage to the electrode, the zeta-potential at the wall can be changed locally. Thus, the electrode acts as a "gate" for liquid flow, in analogy with a gate in a field-effect transistor. In this paper we will show three aspects of a Field Effect Flow Control (FEFC) structure. We demonstrate the induction of directional flow by the synchronized switching of the gate potential with the channel axial potential. The advantage of this procedure is that potential gas formation by electrolysis at the electrodes that provide the axial electric field is suppressed at sufficiently large switching frequencies, while the direction and magnitude of the EOF can be maintained. Furthermore we will give an analysis of the time constants involved in the charging of the insulator, and thus the switching of the zeta potential, in order to predict the maximum operating frequency. For this purpose an equivalent electrical circuit is presented and analyzed. It is shown that in order to accurately describe the charging dynamics and pH dependency the traditionally used three capacitor model should be expanded with an element describing the buffer capacitance of the silica wall surface.

[A schizophrenic patient with loss of teeth]. / Een schizofrene patiënte met verlies van gebitselementen.

A 53-year-old woman, known with a schizophrenic disorder and a history of drug addiction, was referred because of progressive hematomas of the lower extremities and fatigue. Her medical history included hyperplastic gums, tooth hypermobility and anaemia. Scurvy was diagnosed as a result of an insufficient diet due to drug addiction and a paranoid psychosis. After suppletion of vitamin C and starting highly nutritious food a rapid amelioration of the scurvy related complaints was observed. While dreaded and often fatal in earlier eras, in the 21st century scurvy is easily treatable if this diagnosis is recognised.

[Bruises, loose teeth and fatigue in a patient with schizophrenia]. / Blauwe plekken, uitvallende tanden en vermoeidheid bij een patiënte met schizofrenie.

A 53-year-old woman was referred because of progressive haematomas of the lower extremities and fatigue. Her medical history included hyperplastic gums and tooth loss. Scurvy was diagnosed; this was the result of an insufficient diet due to a paranoid psychosis. There was a dramatic improvement within a few days after addition of vitamin C and starting highly nutritious food. Scurvy is easily treated, but is not a disease of the past.

[Devastating community-acquired Staphylococcus aureus bacteremia]. / Verwoestende bacteriëmie met Staphylococcus aureus van buiten het ziekenhuis.

Three patients, two men aged 52 and 62 years and a woman aged 83 years, experienced non-specific flu-like symptoms for a few days but subsequently developed a complicated disease with multiple metastatic infections and endocarditis due to bacteraemia. Only the man aged 62 years had a port of entry, a finger wound. Two patients died. Community-acquired S. aureus bacteraemia is a much more serious disease than nosocomial bacteraemia. The community-acquired bacteraemia is characterised by the absence of a primary focus and non-specific flu-like symptoms in the beginning. This results in a long-duration bacteraemia with a high incidence of metastatic infections, endocarditis and a high mortality rate. A multidisciplinary treatment approach with a careful search for and treatment of endocarditic and metastatic infections in combination with long-duration, high-dose antibiotics is warranted.

Six-year follow-up after successful triple therapy for Helicobacter pylori infection in patients with peptic ulcer disease.

OBJECTIVE & DESIGN: We question whether Helicobacter pylori eradication in peptic ulcer disease patients leads to a decrease in symptoms and reduced use of anti-dyspeptic drugs. Therefore, the recurrence rate of H. pylori, upper abdominal symptoms and the use of acid-suppressive drugs were determined 6 years after successful triple therapy. METHODS: Peptic ulcer disease patients successfully treated in 1990-1993 with 'classic' triple therapy were eligible. Patients were asked about symptoms and invited for a 13C-urea breath test or endoscopy in 1997-1998. Data on the use of anti-dyspeptic drugs were obtained from the pharmacy or general practitioner. RESULTS: Of the 113 eligible patients, 90 could be included in the study. The mean follow-up time was 6 years (range 4.6-7.6 years). H. pylori infection recurred in one patient (recurrence rate: 0.19% per patient-year; 95% confidence interval: 0.01-1.1%). Moderate or severe symptoms were experienced before therapy by 79% of the patients and after therapy by 18% of the patients (P< 10(-7)). Before triple therapy, 98% of the patients used H2-receptor antagonists and 54% were on maintenance treatment. After treatment, 30% used anti-dyspeptic medication and only 13% were on maintenance treatment (P < 10(-7)). CONCLUSIONS: Six years after successful triple therapy in peptic ulcer disease patients, the recurrence rate of H. pylori infection is low and both symptoms and the use of anti-dyspeptic drugs have decreased significantly.

Implications of the simultaneous presence of metronidazole-susceptible and -resistant Helicobacter pylori colonies within a single biopsy specimen.

This study examined whether the simultaneous presence of metronidazole-susceptible and -resistant Helicobacter pylori colonies in a single biopsy specimen is caused by a multiple strain infection with a susceptible and a resistant strain or by two subpopulations within a single strain. Single colonies obtained from seven biopsy specimens known to harbour both susceptible and resistant Helicobacter pylori were fingerprinted by restricted fragment length polymorphism typing of the ureC gene and by the random amplified polymorphic DNA procedure. Metronidazole susceptibility was determined by the E test. The results indicated that the occurrence of metronidazole-resistant and metronidazole-susceptible bacteria within a single biopsy does not imply the presence of a multiple strain infection with one resistant and one sensitive strain.

Mechanism and clinical significance of metronidazole resistance in Helicobacter pylori.

Metronidazole was introduced in 1959 for the treatment of Trichomonas vaginalis, but was subsequently shown to be active against anaerobic and some micro-aerophilic bacteria as well. In anaerobic microorganisms with their low redox potential, metronidazole is reduced to its active metabolite by a one-electron transfer step. Metronidazole is often used in treatment regimens for Helicobacter pylori, a microaerophilic bacterium, but resistance to this drug is frequently encountered. The metabolism of metronidazole in H. pylori must differ from that in anaerobic bacteria as metabolites formed by a one-electron transfer are readily re-oxidized in the micro-aerophilic environment of H. pylori. This process is called 'futile cycling' and is accompanied by the formation of toxic oxygen radicals that are neutralized by an active scavenger system. Recently, it has been shown that in H. pylori, in contrast to the situation in anaerobes, an oxygen-insensitive nitroreductase. encoded by the rdxA gene, is responsible for the activation of metronidazole. Activation by this enzyme is by a two-electron transfer step, preventing futile cycling' and thereby enabling the activation of metronidazole in a micro-aerophilic environment. Metronidazole resistance has been shown to be associated with null mutations in the rdxA gene in most clinical isolates. However, there may be some 'background metronidazole susceptibility' in metronidazole-resistant strains caused by other (oxygen-sensitive) nitroreductases. Recently, three meta-analyses of the impact of metronidazole resistance on treatment efficacy have all shown a significant reduction in efficacy of metronidazole containing regimens in patients infected with a resistant strain. The impact of resistance proved to be dependent on the other components of the regimen and on treatment duration.

Review article: nitroimidazole resistance in Helicobacter pylori.

The efficacy of a nitroimidazole-containing regimen for the treatment of Helicobacter pylori infection is decreased by nitroimidazole resistance. Nitroimidazoles are meta- bolized by H. pylori by several nitro-reductases of which an oxygen-insensitive NADPH nitroreductase encoded by the rdxA gene is the most important. Null mutations in this gene are associated with resistance. Susceptibility testing to nitroimidazoles may give variable results. This is not only related to the slow growth under specific conditions, but also to variability in the activity of the other nitroreductases and the ability to deactivate toxic metabolites of an NI and to repair DNA damage. Moreover, co-infections with resistant and susceptible bacteria are frequently found. The presence of nitroimidazole resistance is related to the previous use of this drug. The prevalence of resistance is rising and nowadays 10-50% of the isolates are resistant. Resistance reduces the efficacy of a treatment regimen to a variable degree. This is related to efficacy of the other components of the regimen and the treatment duration. Whether a nitroimidazole is still effective in resistant strains remains unresolved. When nitroimidazole resistance is present, a nitro-imidazole-containing regimen should be avoided or a regimen with other highly effective components should be used.

Reliability of biopsy-based diagnostic tests for Helicobacter pylori after treatment aimed at its eradication.

OBJECTIVE: Recurrence of Heliobacter pylori after apparently successful treatment mostly represents resurgence of the infection, rather than a new one. Therefore, the reliability of biopsy-based tests after treatment was investigated. METHODS: Four weeks or more after treatment, antral biopsy samples were taken for culture, histology, urease test and polymerase chain reaction (PCR), and a corpus specimen for culture. Treatment failure was defined as > or = 2 tests positive. If one test was positive, a 13C-urea breath test was performed and considered conclusive. RESULTS: One hundred and ninety-seven patients were evaluated. Endoscopy was performed 53 days (27-92 days) after treatment. Twenty-one patients with missing test results and 19 patients on acid-suppressive drugs were excluded. In 140 of 156 patients (89.7%), H. pylori was eradicated. Sensitivity and specificity of culture of antrum were, respectively, 100% and 100%; culture of corpus, 100% and 100%; rapid urease test, 87% and 99%; haematoxylin/eosin stain, 94% and 95%; Giemsa stain, 81% and 99%; and PCR, 88% and 100%. CONCLUSION: Although all biopsy-based tests are reliable after treatment, culture is the biopsy-based test of first choice as it is the most accurate and gives additional information on antibiotic resistance.

The influence of in vitro nitroimidazole resistance on the efficacy of nitroimidazole-containing anti-Helicobacter pylori regimens: a meta-analysis.

OBJECTIVE: The aim of this study was to determine the influence of nitroimidazole resistance (NIR) on the efficacy of treatment for Helicobacter pylori (H. pylori) infections by meta-analysis of the world literature. METHODS: A MEDLINE search, a manual search of all major gastroenterological journals from 1993 to 1997, and abstracts of gastroenterological and H. pylori meetings from 1993 to 1997 were performed. All treatment studies using a nitroimidazole and providing data about the medication used, dose frequency, total daily dose, duration of treatment, and eradication results in relation to NIR were included. Eradication had to be assessed by two biopsy-based tests or a urea breath test > or = 4 wk after treatment. Individual studies were pooled into groups according to the medication used and the duration of treatment. The pooled estimate of the odds ratio (OR) of NIR for treatment failure and its 95% confidence interval (95% CI) were calculated for each group using the logit method. To detect any possible bias, funnel plots (plots of effect estimates against sample size) were constructed. RESULTS: A total of 91 treatment arms, including a total of 4823 patients, were evaluated. The pooled ORs of NIR for treatment failure (95% CI) of proton pump inhibitors, bismuth, and quadruple regimens were 5.2 (3.8-7.1), 5.9 (4.1-8.3), and 7.0 (3.1-16.0), respectively. Eradication rates were 90% in susceptible strains but <75% in resistant strains. In susceptible strains, neither treatment duration nor the choice of the second antibiotic influenced efficacy. In resistant strains, tetracycline was more effective than amoxicillin (bismuth regimens), and the longer the duration of regimens (bismuth-amoxicillin regimens) the more effective they were. Only quadruple regimens given for > or = 1 wk were effective in resistant strains. CONCLUSIONS: NIR decreases treatment efficacy. Treatment duration and choice of other drugs influence the impact of NIR on treatment efficacy. If NIR is present, a nitroimidazole-containing regimen should be avoided or a quadruple regimen should be given for > 1 wk.