Management of gastrointestinal motility disorders. A practical guide to drug selection and appropriate ancillary measures

Curcumin improves expression of SCF/c-kit through attenuating oxidative stress and NF-κB activation in gastric tissues of diabetic gastroparesis rats

BACKGROUND

Diabetes mellitus is associated with many kinds of complications. Recent studies have shown that oxidative stress and inflammatory reactions have critical roles in the pathogenesis of diabetic gastroparesis. Curcumin is known to have antioxidant and anti-inflammatory properties. In the present study, we investigated the effect of curcumin on diabetic gastric motility in a Sprague Dawley rat model of type 1 diabetes mellitus.

METHODS

Male SD rats were divided into a control group, a control group receiving curcumin, a diabetic group, and a diabetic group receiving curcumin. Diabetes was induced by intraperitoneal injection of streptozotocin. Curcumin (150 mg/kg) was given intragastrically for 6 weeks, and blood glucose levels and body weights were measured. Stomachs were excised for analysis of gastric emptying rates, and levels of oxidative stress. NF-κB, I-κB, and stem cell factor (SCF)/c-kit protein levels were assessed by western blot analysis, while the apoptosis of interstitial cells of Cajal (ICCs) was assessed by TUNEL staining.

RESULTS

Curcumin-treated diabetic rats showed significantly improved gastric emptying rates [(59.4 ± 7.5)%] compared with diabetic rats [(44.3 ± 5.7)%], as well as decreased levels of MDA [21.4 ± 1.8 (nmol/mg) vs 27.9 ± 2.1 (nmol/mg)], and increased SOD activity [126.2 ± 8.8 (units/mg) vs 107.9 ± 7.5 (units/mg)]. On the other hand, the gastric emptying level in the control group was not significantly different from that in the control group receiving curcumin treatment. In addition, curcumin-treated diabetic rats showed significantly increased levels of SCF/c-kit protein in stomach tissues, inhibited I-κB degradation and NF-κB activation, and reduced ICC apoptosis index [(26.2 ± 4.1)% vs (47.5 ± 6.2)%], compared with the diabetic group.

CONCLUSION

Curcumin treatment improved gastric emptying by blocking the production of oxidative stress, abolishing NF-κB signal transduction and enhancing expression of SCF/c-kit in rats with diabetic gastroparesis.

Diffuse esophageal spasm: the surgical approach

Diffuse esophageal spasm (DES) is a rare primary motility disorder of unknown cause, that can be found in patients complaining of chest pain and dysphagia and in whom ischemic heart disease and GERD have been excluded. The manometric hallmark of DES is the presence of simultaneous contractions in the distal esophagus alternating with a normal peristalsis. Even at specialized esophageal motility laboratories, DES is considered an uncommon diagnosis. In this review, the authors discuss the clinical and diagnostic aspects of this disease, as well as the possible therapeutic options (medical, endoscopic or surgical therapy). Surgery (esophageal myotomy performed through a thoracotomy or with a thoracoscopic access) seems to have a better outcome than medical or endoscopic treatment, and it is considered "the last resource" in these patients. However, satisfactory results are reported, from highly skilled centers, in only about 70% of treated cases, certainly inferior to those achieved in other esophageal disorders. The role of surgery in this disease requires therefore further study, even if controlled trials are probably difficult to perform, due to the rarity of the disease.

Ameliorating effects and mechanisms of electroacupuncture on gastric dysrhythmia, delayed emptying, and impaired accommodation in diabetic rats

The aim of this study was to investigate the effects and mechanisms of electroacupuncture (EA) on gastric accommodation, gastric dysrhythmia, and gastric emptying (GE) in streptozotocin (STZ)-induced diabetic rats. Five experiments were performed in five groups of STZ-induced diabetic rats to study the effects of EA at ST-36 (Zusanli) on gastric slow-wave dysrhythmia, delayed GE and intestinal transit, impaired gastric accommodation, and the mechanisms of EA involving the autonomic and opioidergic pathways. We found the following: 1) EA improved gastric dysrhythmia in the diabetic rats. The normal percentage of slow waves was 55.4 +/- 2.9% at baseline and significantly increased to 69.2 +/- 2.2% with EA (P = 0.01); this effect was blocked by naloxone. 2) EA resulted in a 21.4% increase in GE and 18.2% increase in small intestinal transit in the diabetic rats. 3) EA restored diabetes-induced impairment in gastric accommodation. Gastric accommodation was 0.98 +/- 0.13 ml with sham EA and significantly increased to 1.21 +/- 0.15 ml with EA (P = 0.01), and this effect was blocked by naloxone. 4) EA increased vagal activity assessed by the spectral analysis of the heart rate variability. We concluded that EA at ST-36 improves gastric dysrhythmia, delayed GE and intestinal transit, and impaired accommodation in STZ-induced diabetic rats, and the improvement seems to be mainly mediated via the vagal pathway. EA may have a promising therapeutic potential for diabetic gastroparesis.

Current diagnosis and therapy for diffuse esophageal spasm

Diffuse esophageal spasm is a primary esophageal motility disorder characterized by incoordinate esophageal contraction. The etiology is still not clear. This study systemically elucidates the latest advancement in pathogenesis, diagnosis and therapy of diffuse esophageal spasm, and then gives an objective and analytic evaluation. In this article, we also provide new diagnostic and therapeutic strategies for patients with diffuse esophageal spasm.

Diffuse esophageal spasm

The purpose of this article is to review the clinical features, pathophysiology, diagnosis, and management of patients with diffuse esophageal spasm (DES). The PubMed database was searched with a focus on recent publications, using keywords "DES," plus "epidemiology," "prevalence," "diagnosis," "pathogenesis," "calcium channel blocker," "nitrates," "botulinum toxin," "antidepressants," "dilation," and "myotomy." The reference lists of papers identified in the initial PubMed search were reviewed for further relevant publications.

Synchronized gastric electrical stimulation improves delayed gastric emptying in nonobese mice with diabetic gastroparesis

The aim of this study was to investigate the effect and mechanism of synchronized gastric electrical stimulation (SGES) on gastric emptying in nonobese mice with diabetic gastroparesis (DB-GP). Eight control mice and 48 nonobese diabetic (NOD) mice with two pairs of gastric electrodes were used in this study. The study included seven groups in a randomized order [control, diabetes (DB), DB-GP, DB + SGES, DB-GP + SGES, DB-GP + Atropine, and DB-GP + SGES + Atropine groups]. In the control, DB, DB-GP, and DB-GP + Atropine groups, gastric emptying was measured in BLAB/cJ mice (control group) or NOD mice with a duration of diabetes of 0-7 days (DB group) or 28-35 days (DB-GP or DB-GP + Atropine group). In the DB + SGES, DB-GP + SGES, and DB-GP + SGES + Atropine groups, the experiment was the same as the corresponding DB, DB-GP, and DB-GP + Atropine groups except that SGES was applied during the experiment. SGES was applied via the proximal pair of electrodes and synchronized with the intrinsic gastric slow waves. The following results were obtained: 1) gastric emptying was delayed in NOD mice with a duration of diabetes of 28-35 days; 2) SGES was able to significantly increase gastric emptying in both diabetic mice and diabetic gastroparetic mice; and 3) the excitatory effect of SGES was completely blocked by atropine. SGES accelerates gastric emptying in NOD mice with diabetic gastroparesis. The effect of SGES on gastric emptying is mediated via the cholinergic pathway. These findings suggest that SGES may have a therapeutic potential for treating patients with diabetic gastroparesis.

Current concepts on pathophysiology, diagnosis and treatment of diffuse oesophageal spasm

Diffuse oesophageal spasm is a functional oesophageal motility disorder of unknown aetiology, which appears to be due to a disturbance of the normal pharmacological timing of propulsive contraction occurring in the oesophageal body after swallowing. The lack of pathophysiological understanding may be due to the fact that there is more than one pathophysiological pathway causing symptoms of diffuse oesophageal spasm. Barium studies, oesophageal scintigraphy and fiberoptic examination can be helpful in finding the correct diagnosis, but manometry is still the gold standard of diagnostic procedures. Similar to other spastic oesophageal motility disorders, pharmacological treatment of diffuse oesophageal spasm includes nitrates, calcium antagonists, anticholinergics and antidepressants with varying beneficial effects. Botulinum toxin, which provides sufficient treatment as measured by symptom score and manometric patterns in patients with achalasia, was recently evaluated for the treatment of diffuse oesophageal spasm in small patient selections with promising results.

Enteral feeding: drug/nutrient interaction

Enteral nutrition support via a feeding tube is the first choice for artificial nutrition. Most patients also require simultaneous drug therapy, with the potential risk for drug-nutrient interactions which may become relevant in clinical practice. During enteral nutrition, drug-nutrient interactions are more likely to occur than in patients fed orally. However, there is a lack of awareness about its clinical significance, which should be recognised and prevented in order to optimise nutritional and pharmacological therapeutic goals of safety and efficacy.

LEARNING OBJECTIVES

To raise the awareness of potential drug-nutrient interactions and influence on clinical outcomes. To identify factors that can promote drug-nutrient interactions and contribute to nutrition and/or therapeutic failure. To be aware of different types of drug-nutrient interactions. To understand complex underlying mechanisms responsible for drug-nutrient interactions. To learn basic rules for the administration of medications during tube-feeding.

Failure of a motilin receptor agonist (ABT-229) to relieve the symptoms of functional dyspepsia in patients with and without delayed gastric emptying: a randomized double-blind placebo-controlled trial

INTRODUCTION

Motilin-receptor agonists are prokinetics; whether they relieve the symptoms of functional dyspepsia is unknown. We aimed to test the efficacy of the motilin agonist ABT-229 in functional dyspepsia patients with and without delayed gastric emptying.

METHODS

Patients were randomized with postprandial symptoms and documented functional dyspepsia by endoscopy (n=589 in intention-to-treat analysis). Patients were assigned to either the delayed or normal gastric emptying strata, based on a validated 13C octanoic acid breath test. Patients were then further randomized within each strata, to receive one of four doses of ABT-229 (1.25, 2. 5, 5 or 10 mg b.d. before breakfast and dinner) or placebo for 4 weeks, following a 2-week baseline. The primary outcome was the assessment of change in symptom severity over the 2 weeks from baseline to final visit, based on a self-report questionnaire measuring severity on visual analogue scales.

RESULTS

Baseline characteristics across the treatment arms were very similar. No significant differences in the upper abdominal discomfort severity score (maximum 800 mm) were observed for any active treatment arm vs. placebo (mean change from baseline -139, -141, -145, -160 and -134 mm for placebo, 1.25, 2.5, 5, and 10 mg, respectively, at 4 weeks by intention-to-treat). More patients on placebo reported a good or excellent global response than patients on 1.25 or 5 mg of active therapy (both P < 0.05). The results were very similar in those with and without delayed gastric emptying. Helicobacter pylori status did not predict response. Excluding patients with any baseline heartburn (total remaining n=240), ABT-229 10 mg was inferior to placebo in relief of upper abdominal discomfort.

CONCLUSIONS

ABT-229 was of no value for relief of symptoms in functional dyspepsia, compared with placebo.

Ogilvie's syndrome after cesarean delivery

Ogilvie's syndrome is a rare postsurgical complication that can be associated with cesarean delivery. It is characterized by massive dilation of the colon, much like that which occurs with an obstruction but in the absence of a mechanical obstruction. Early detection and intervention are necessary to avoid serious morbidity and/or mortality. Conservative treatment is effective in many cases, but surgical intervention may be required. Nursing assessment of the gastrointestinal system in the postsurgical patient is reviewed using a case report of a patient who developed Ogilvie's syndrome after a cesarean delivery.

Functional gut disorders: from motility to sensitivity disorders. A review of current and investigational drugs for their management

Functional gut disorders include several clinical entities defined on the basis of symptom patterns (e.g., functional dyspepsia, irritable bowel syndrome, functional abdominal pain, functional abdominal bloating), for which there is no established pathophysiological mechanism. Because there is no well-defined pathophysiological target, treatment should be aimed at symptom improvement. Prokinetics and antispasmodics have been widely used in the treatment of functional gut disorders on the assumption that disordered motility is the underlying cause of symptoms, and symptom improvement is indeed achievable with these compounds in some, but not all, patients with features of hypo- or hypermotility, respectively. In the first part of this review, we cover the basic pharmacology and discuss the rationale for the clinical use of prokinetics and antispasmodics. On the other hand, in the past few years, the explosive growth in the research focusing on visceral sensitivity and visceral reflexes has suggested that at least some patients with functional gut disorders have altered visceral perception. Thus, the second part of the review covers these developments and focuses on studies addressing the issue of drugs modulating visceral sensitivity.