Hanaa S. Sallam

Transcutaneous Electrical Nerve Stimulation (TENS) Improves Upper GI Symptoms and Balances the Sympathovagal Activity in Scleroderma Patients

To assess the impact of transcutaneous electrical nerve stimulation (TENS) at gastrointestinal (GI) acupoints on GI symptoms and quality of life in scleroderma patients, 17 patients filled out SF-36 and GI symptom questionnaires before the electrocardiogram was recorded for two intervals: baseline and TENS. At home, patients applied TENS for 14 days, then were reassessed.Acutely, TENS application significantly increased sympathetic and vagal activities vs. baseline (P= 0.02 and P= 0.004), respectively. Prolonged TENS application normalized the sympathovagal balance (P= 0.04), decreased GI symptom scores (P= 0.02) and increased the physical functioning score (SF36), which strongly correlated with the change in the sympathovagal balance (r= 0.6, P= 0.02). In conclusion, TENS at GI acupoints offers a potential option in the treatment of upper GI symptoms, but further study is necessary.

Feasibility of gastric electrical stimulation by percutaneous endoscopic transgastric electrodes.

BACKGROUND Gastric electrical stimulation has been used for the treatment of drug refractory GI motility disorders and for the treatment of obesity. Both these indications have involved surgical placement of gastric electrodes, which adds to the complexity and cost of the procedure. Endoscopic placement is therefore an attractive alternative approach for this therapy. OBJECTIVE Our purpose was to investigate the feasibility, safety, and efficacy of percutaneous endoscopic electrodes for gastric electrical stimulation. DESIGN AND SETTING Experimental animal study in hound dogs. INTERVENTIONS Percutaneous endoscopic transgastric electrode (PETE) placement was carried out by using a pair of gastric pacing wires attached to a percutaneous endoscopic gastrostomy tube. In addition, 4 pairs of gastric serosal electrodes were implanted surgically for comparison. The efficacy of the percutaneous endoscopic electrodes was defined by their ability to entrain gastric slow waves and the induction of dysrhythmia. RESULTS (1) The PETE recorded gastric slow waves comparable to the serosal electrodes. (2) Gastric electrical stimulation with long pulses delivered by the PETE, at a frequency of 10% higher than the intrinsic gastric slow wave frequency, entrained gastric slow waves. (3) Gastric electrical stimulation delivered by the PETE, at a tachygastric frequency, induced gastric dysrhythmia. LIMITATIONS This was an animal study; however, its results are expected to be reproducible in humans, with PETE kept in place for even a longer duration than 6 to 8 weeks. CONCLUSION PETE placement is both feasible and safe. PETEs are effective, having a potential for use in treatment of both gastroparesis and obesity.

Resistin: An Inflammatory Cytokine. Role in Cardiovascular Diseases, Diabetes and the Metabolic Syndrome

Resistin is an adipocyte- and monocyte-derived cytokine which has been implicated in the modulation of insulin action, energy, glucose and lipid homeostasis. Resistin has been associated with insulin resistance and many of its known complications. As a molecular link between metabolic signals, inflammation, and vascular dysfunction, resistin can be proposed as playing a significant role in the heightened inflammatory state induced by metabolic stress linked to excessive caloric intake, thus contributing to the risk for metabolic syndrome (MetS), type 2 diabetes (T2DM), and cardiovascular diseases (CVD). In this review, we highlighted the role of resistin, as an inflammatory cytokine, in the development of CVD, T2DM and the MetS.

Gastric slow waves, gastrointestinal symptoms and peptides in systemic sclerosis patients

Abstract  Impaired gastric slow waves, frequent gastrointestinal (GI) symptoms and altered GI peptides have been reported in Scleroderma (SSc) patients. The aim of this study was to investigate the associations among these three important components in GI dysmotility. Seventeen fasted SSc patients underwent four channel surface electrogastrography, measuring % of normal gastric slow waves or dysrhythmia. Patients completed a questionnaire designed by us to assess demographics, upper and lower GI symptoms (symptom presence, frequency and impact on quality of life, QOL), by YES/NO, Likert Scales and Visual Analogue Scales 1–100 mm (called GI Dysmotility Questionnaire, GIDQ) and health‐related QOL by SF‐36. Fasting plasma vasoactive intestinal peptide (VIP) and motilin levels were measured by peptide immunoassays. There were significant correlations between percentages of gastric dysrhythmias (bradygastria or arrhythmia) and a number of major GI symptoms such as nausea, abdominal bloating and pain. The plasma level of VIP was correlated positively with % dysrhythmia but negatively with % normal slow waves. Motilin was positively correlated with slow wave coupling (coordination). No major differences were noted in the measured peptides or gastric slow waves between limited SSc and diffuse SSc. Correlations were noted between SF‐36 domain scores and our GIDQ scores. In SSc patients, gastric dysrhythmias are correlated with certain GI symptoms. Correlations are also noted between plasma VIP/Motilin levels and gastric slow waves. Thus in SSc, gastric dysrhythmias may be predictive of development of certain dyspeptic symptoms. Plasma VIP may be involved in the development of dysrhythmias.

Electroacupuncture improves burn-induced impairment in gastric motility mediated via the vagal mechanism in rats

Delayed gastric emptying (GE) is common in patients with severe burns. This study was designed to investigate effects and mechanisms of electroacupuncture (EA) on gastric motility in rats with burns.

The prokinetic face of ghrelin.

This review evaluated published data regarding the effects of ghrelin on GI motility using the PubMed database for English articles from 1999 to September 2009. Our strategy was to combine all available information from previous literature, in order to provide a complete structured review on the prokinetic properties of exogenous ghrelin and its potential use for treatment of various GI dysmotility ailments. We classified the literature into two major groups, depending on whether studies were done in health or in disease. We sub-classified the studies into stomach, small intestinal and colon studies, and broke them down further into studies done in vitro, in vivo (animals) and in humans. Further more, the reviewed studies were presented in a chronological order to guide the readers across the scientific advances in the field. The review shows evidences that ghrelin and its (receptor) agonists possess a strong prokinetic potential to serve in the treatment of diabetic, neurogenic or idiopathic gastroparesis and possibly, chemotherapy-associated dyspepsia, postoperative, septic or post-burn ileus, opiate-induced bowel dysfunction and chronic idiopathic constipation. Further research is necessary to close the gap in knowledge about the effect of ghrelin on the human intestines in health and disease.

Gastric and small bowel ileus after severe burn in rats: The effect of cyclooxygenase-2 inhibitors

Gastrointestinal (GI) ileus is a common complication after severe burns. Selective cyclooxygenase-2 inhibitors (COX-2i) improved post-operative ileus, but its effect on burn-induced GI dysmotility is unknown. Our aim was to test whether a COX-2i improves gastric emptying (GE) and small bowel transit (SBT) after burn. Experiment on GE: rats were anesthetized and randomized into sham/scald burn, treated/untreated with COX-2i. Six hours after burn, rats received a phenol red meal and were sacrificed 30 min later. Gastric emptying was determined based on the percentage of phenol red recovered in harvested stomachs. Experiment on SBT: rats received a duodenostomy and were scald/sham burned 5 days later. Six hours after burn, rats received a phenol red meal through the duodenostomy catheter and were sacrificed 100 min later. Geometric center (GC) was calculated for SBT. GE was decreased significantly in burned vs. sham animals (p<0.001). SBT was significantly impaired in burned vs. sham animals (p<0.001). The COX-2i improved GE in the burn rats but not GE in the control rats or SBT in the burn rats. COX-2i improves burn-induced delayed GE, suggesting the mediation of the latter via the prostaglandin pathway.

Effects of audio stimulation on gastric myoelectrical activity and sympathovagal balance in healthy adolescents and adults

Aim:  The primary aim of this study was to investigate the effects of different audio stimulations on gastric myoelectrical activity and sympathovagal balance in adolescents compared with adults.

Colorectal and rectocolonic reflexes in canines: involvement of tone, compliance, and anal sphincter relaxation

Distention of the proximal colon may have inhibitory or excitatory effects on the rectum and vice versa. The reflexes between the proximal colon and the rectum have not been well studied due to difficulties in accessing the proximal colon. The aim of this study was to investigate the reflex responses and their mechanisms between the proximal colon and the rectum in consideration of distention-related changes in tone and compliance of these regions as well as anal sphincter relaxation in a canine model. Proximal colon/rectal tone, compliance, and anal sphincter relaxation were investigated in six dogs chronically implanted with a proximal colon cannula while in the fasting state and during proximal colon distention or rectal distention. It was found that: 1) both rectal distention and proximal colon distention significantly and substantially decreased the compliance of the opposite regions, and guanethidine abolished proximal colon distention-induced changes in rectal compliance; 2) rectal/proximal colon distension decreased proximal colonic/rectal tone, and guanethidine abolished both of these inhibitory effects; 3) the anal sphincter was more sensitive to rectal distention than proximal colon distention; and 4) the minimal distention pressure required to induce anal inhibitory reflex was lower for rectal distention than proximal colon distention. It was concluded that distention-related changes in tone and compliance suggest the long inhibitory reflexes between the proximal colon and the rectum with the sympathetic involvement in rectal responses. The anal sphincter is more sensitive to the distention of the rectum than that of the proximal colon.

Mechanisms of burn-induced impairment in gastric slow waves and emptying in rats

Delayed gastric emptying is common following severe large cutaneous burns; however, the mechanisms of burn-induced delayed gastric emptying remain unknown. The aim of this study was to explore the possible involvement of hyperglycemia and cyclooxygenase-2 receptors in the burn-induced gastric dysrhythmias. Gastric slow waves and gastric emptying were assessed in rats 6 h following sham or burn injury. Animals were randomized to one sham-burn and seven burn groups: untreated; two groups of saline treated (control); insulin treated (5 IU/kg); cyclooxygenase-2 inhibitor treated (10 mg/kg); ghrelin treated (2 nmol/rat); and gastric electrical stimulation treated. It was found that 1) severe burn injury impaired gastric slow waves postprandially and delayed gastric emptying; 2) the impairment in gastric slow waves included a decrease in the slow-wave frequency and in the percentage of normal slow waves, and an increase in the percentage of bradygastria (P = 0.001, 0.01, and 0.01, respectively vs. preburn values). None of the gastric slow-wave parameters was significantly correlated with gastric emptying; 3) cyclooxygenase-2 inhibitor normalized burn-induced delayed gastric emptying (P = 0.3 vs. sham-burn), but not gastric dysrhythmias (P < 0.002 vs. sham), whereas insulin normalized both gastric emptying (P = 0.4 vs. sham-burn) and gastric dysrhythmias (P = 0.3 vs. sham-burn); 4) both gastric electrical stimulation and ghrelin accelerated burn-induced delayed gastric emptying (P = 0.002 and 0.04, respectively, vs. untreated burn). In conclusion, hyperglycemia alters gastric slow-wave activity and delayed gastric emptying, while cyclooxygenase-2 inhibition delays gastric emptying without altering gastric slow-wave activity.