PGD to reduce reproductive risk: the case of mitochondrial DNA disorders.

This paper discusses the pros and cons of introducing PGD for mitochondrial DNA (mtDNA) disorders such as NARP (Neurogenic muscle weakness, Ataxia, Retinis Pigmentosa)/Leigh, MELAS (Mitochondrial myopathy, Encephalopathy, Lactic acidosis, and Stroke-like episodes), private mtDNA mutations and LHON (Leber Hereditary Optic Neuropathy). Although there is little experience with PGD for mtDNA disorders, it is reasonable to assume that in many cases, the best one can achieve is the selection of the 'least' affected embryos for transfer. So instead of 'promising' parents a healthy child, PGD in these cases can only aim at reducing reproductive risk.

Impedance-pH monitoring: new standard for measuring gastro-oesophageal reflux.

Impedance monitoring is a new technique that can be used to detect the flow of fluids and gas through hollow viscera. With impedance monitoring gastro-oesophageal reflux can be detected independent of its acidity by differences in electrical impedance between the mucosal surface, fluids and gas that surround the catheter. Clinically, it is used in combination with oesophageal pH monitoring, and the combination of impedance-pH monitoring allows recognition of both acidic and weakly acidic reflux episodes.

[Sigmoid carcinoma as a long-term complication following ureterosigmoidostomy].

A 45-year-old woman, known to have a congenital exstrophy ofthe bladder, for which she underwent a ureterosigmoidostomy in her infancy, presented with fever. This was due to pyelonephritis, from which she recovered with antibiotic therapy. During colonoscopy a carcinoma of the sigmoid was found at the level of the anastomosis of the ureters.

Refractory gastrooesophageal reflux disease.

The introduction of proton pump inhibitors (PPIs) has facilitated the treatment of gastrooesophageal reflux disease (GORD) enormously; however, treatment of GORD still fails in a small proportion of patients. This small proportion of therapy-resistant patients encompasses a substantial part of the working load of physicians and has become a common clinical problem. A strong variability in acid-suppressive effect of PPI treatment exists depending on compliance, Helicobacter pylori status and genotype.

High-resolution manometry.

Recently, high-resolution oesophageal manometry was added to the armamentarium of researchers and gastroenterologists. Current studies suggest that the yield of high-resolution oesophageal manometry is higher than that of conventional pull-through manometry and is at least comparable to that of sleeve sensor manometry. Probably the most important advantage of solid-state high-resolution manometry is that it makes oesophageal manometry faster and easier to perform.

Dealing with uncertainties: ethics of prenatal diagnosis and preimplantation genetic diagnosis to prevent mitochondrial disorders.

This paper aims to address the ethical issues regarding prenatal diagnosis and preimplantation genetic diagnosis (PGD) of mitochondrial disorders. Owing to the absence of effective treatment, the prevention of the transmission of mitochondrial disorders is considered to be of key importance. The characteristics of mtDNA, such as heteroplasmy and the genetic bottleneck, make it difficult to estimate recurrence risks correctly and to provide an accurate prognosis for many mtDNA mutations.

High-resolution manometry of the esophagus: more than a colorful view on esophageal motility?

Since the introduction of pressure measurement of the esophagus, there has been a stepwise improvement in manometric techniques and the recognition of esophageal manometry as a useful tool to evaluate esophageal function in clinical practice. The newest development in this field is high-resolution manometry of the esophagus. In this review, we will briefly discuss the indications for esophageal manometry and we will focus on the development of the technique of high-resolution manometry and the new insights that were obtained by using this emerging tool.

Oesophageal high-resolution manometry: moving from research into clinical practice.

Manometry measures pressure within the oesophageal lumen and sphincters, and provides an assessment of the neuromuscular activity that dictates function in health and disease. It is performed to investigate the cause of functional dysphagia, unexplained "non-cardiac" chest pain, and in the pre-operative work-up of patients referred for anti-reflux surgery. Manometric techniques have improved in a step-wise fashion from a single pressure channel to the development of high-resolution manometry (HRM) with up to 36 pressure sensors.

Mechanisms of acid, weakly acidic and gas reflux after anti-reflux surgery.

Background: Whereas it is well documented that fundoplication reduces acid reflux, the effects of the procedure on non-acid and gas reflux and the mechanisms through which this is achieved have not been fully elucidated.

Methods: In 14 patients, reflux was measured with impedance-pH monitoring during a postprandial 90 min stationary recording period before and 3 months after fundoplication. Concomitantly, the occurrence of transient lower oesophageal sphincter relaxations (TLOSRs) and morphology of the oesophagogastric junction were studied with high-resolution manometry.

Physiologic and pathologic belching.

Accumulation of air in the stomach increases gastric volume, which activates receptors in the gastric wall. A reflex is initiated, leading to relaxation of the lower esophageal sphincter, upward movement of the air through the esophagus, and finally passage through the upper esophageal sphincter, during which an audible belch can sometimes be heard. Excessive belching is often reported in patients with gastroesophageal reflux disease and functional dyspepsia.

Air swallowing, belching, acid and non-acid reflux in patients with functional dyspepsia.

Background: Frequent belching is a common symptom in patients with functional dyspepsia with a reported incidence up to 80%. We hypothesized that patients with functional dyspepsia possibly have a higher frequency of belching than healthy subjects secondary to frequent air swallowing.

Aim: To assess air swallowing, belching, acid and non-acid reflux patterns of patients with functional dyspepsia.

The gastro-oesophageal common cavity revisited.

The manometric common cavity phenomenon has been used as indicator of gastro-oesophageal reflux of liquid or gaseous substances. Using combined pH and impedance recording as reference standard the value of a common cavity as indicator of gastro-oesophageal reflux was tested. Ten healthy male subjects underwent combined stationary pressure, pH and impedance recording for 4.

Technology review: Esophageal impedance monitoring.

Intraluminal impedance monitoring is a new technique that can be used to detect the flow of liquids and gas through hollow viscera. In combination with manometry, it is used for esophageal function testing and while manometry provides information on contractile activity, impedance provides information on esophageal bolus transit. This is especially useful in patients with nonobstructive dysphagia.

Characteristics of gastroesophageal reflux in symptomatic patients with and without excessive esophageal acid exposure.

Objective: In some patients with a physiological esophageal acid exposure, an association between reflux episodes and symptoms can be demonstrated. Besides acidity, other factors such as proximal extent may determine whether a reflux episode is perceived or not. We aimed to investigate the reflux profile of gastroesophageal reflux disease (GERD) patients with physiological acid exposure.

Assessment of oesophageal emptying in achalasia patients by intraluminal impedance monitoring.

Oesophageal emptying can be assessed by radiographic and scintigraphic tests with radiation exposure or by multichannel intraluminal impedance monitoring (MII). The aim of this study was to evaluate the applicability of MII for the assessment of oesophageal emptying in achalasia patients. In 10 achalasia patients, impedance tracings were scored independently by three observers after ingestion of a 100-mL barium bolus.

Psychological factors affect the frequency of belching in patients with aerophagia.

Background: In patients with aerophagia and excessive belching an organic cause is seldom found and a psychogenic cause is often suspected.

Aim: To investigate the effects of attention and distraction on the frequency of belching in patients with aerophagia.

Methods: In 10 patients with aerophagia, combined esophageal manometry and impedance monitoring was performed for 2 h, consisting of four 30-minute recording periods.

Effect of dietary sodium chloride on gastro-oesophageal reflux: a randomized controlled trial.

Objective: It has been suggested that a high consumption of sodium chloride (NaCl) is associated with reflux symptoms. The objective of this study was to investigate the effect of increased dietary NaCl intake on gastro-oesophageal reflux and reflux mechanisms.

Material And Methods: In this double-blind, placebo-controlled, crossover study 10 healthy male subjects received 5 g NaCl or placebo in capsules per day for one week, after which concurrent manometric, pH and impedance monitoring was carried out for 4.

Gastro-oesophageal reflux of liquids and gas during transient lower oesophageal sphincter relaxations.

Some transient lower oesophageal sphincter relaxations (TLOSRs) are accompanied by gastro-oesophageal reflux and others are not. We aimed to investigate what factors determine the occurrence and type of reflux during TLOSRs. In 12 healthy subjects prolonged high-resolution manometry was performed.

[Belching (ructus)].

Accumulation of air in the stomach increases the gastric volume, which activates receptors in the gastric wall. This results in a reflex that relaxes the lower oesophageal sphincter, whereby the intragastric air can escape through the oesophagus. Ventilation of the stomach via the oesophagus is known as belching (ructus).

Aerophagia and rumination: recognition and therapy.

Aerophagia and rumination syndrome are functional upper gastrointestinal disorders that are becoming increasingly recognized in otherwise-healthy children and adults. Aerophagia is primarily characterized by troublesome repetitive belching and abdominal symptoms that result from air sucking and swallowing. Rumination syndrome is primarily characterized by regurgitation occurring shortly after meal intake.

Air swallowing, belching, and reflux in patients with gastroesophageal reflux disease.

Objectives: Belching and gastroesophageal reflux share a common physiological mechanism. The aim of this study was to investigate whether air swallowing leads to both belching and reflux.

Methods: Esophageal impedance, pH, and pressure were measured during two 20-min recording periods in 12 controls and 12 patients with gastroesophageal reflux disease (GERD), before and after intragastric inflation of 600 mL of air.

Intermittent spatial separation of diaphragm and lower esophageal sphincter favors acidic and weakly acidic reflux.

Background & Aims: In small hiatal hernias, the size of the hernia is variable. Intermittent complete reduction can be observed with high-resolution manometry as a transition from a double-peak (hernia) to a single-peak (reduced) high-pressure zone. The aim of this study was to investigate whether intermittent separation of the diaphragm and lower esophageal sphincter (LES) favors the occurrence of gastroesophageal reflux.