bluuebunny/crossref_metadata_2025 huggingface dataset:
Living kidney organ donation: experiences of spousal support of donors
Authors: Taylor Laura A , McMullen Patricia
Published: August 2010

Aim.  The purpose of this study was to explore the process of living kidney donation as experienced by husbands of donors to aid nurses and all members of the health care team in promoting informed consent for those considering living donation and to promote the well being of spouses of living donors, donors and their families.

Background.  The attitudes of husbands of living kidney donors may affect their decision to donate and satisfaction with recovery from donation surgery, thus it is critical to know how husbands of living kidney donors view kidney donation.

Methods.  Eleven male spouses of living kidney donors were interviewed three months following their wife's donation. Grounded theory methodology was used to inaugurate a substantive theory that describes living kidney donation and its impact on the spousal relationship and family, as experienced by the husband of a donor.

Results.  The result of the data analysis was a substantive theory pertaining strictly to the husbands’ experiences as the spouse of the living kidney donor. The process commenced with scheduling of the living donation followed by the postoperative time frame, including bringing the donor wife home. The core variable, ‘Fulfilling Your Vows’, described attitudes, behaviours and actions that guided husbands in successfully and generously caring for their wives, their families, the recipients and themselves throughout the living kidney donation process and continuing ‘to this day’.

Relevance to clinical practice.  The substantive theory of ‘Fulfilling Your Vows’ will guide nurses and other transplant specialists in helping to improve fully informed consent of potential donors before surgery and in developing supportive strategies to maximize spouse, donor and family outcomes throughout the transplantation process.
The quality and suitability of written educational materials for patients*
Authors: Demir Fatma , Ozsaker Esma , Ilce Arzu Ozcan
Published: August 2010

Aim.  In this study, the quality and suitability of written educational materials being used for the education of patients in surgical departments of hospitals were studied.

Background.  In the literature, it is stated that most of the educational materials for patients are not suitable from the aspects of contents, structure, design, composition and language.

Method.  In this descriptive type study, which was carried out between March and May 2006, 59 examples of written educational material used for patient education at 138 surgical clinics were evaluated for quality and suitability. The written educational materials obtained were evaluated independently by researchers from the aspect of quality and suitability. The DISCERN measuring instrument was used in the evaluation of the reliability of the written educational materials and the Evaluation of the Suitability of Written Materials form was used in the evaluation of suitability.

Results.  It was determined that the educational materials received low scores for reliability and information quality. It was determined that the total scores for the written educational materials were average for suitability.

Conclusion.  It was determined that there were no written educational materials in more than half of the surgical units included in the study. It was also found that the educational materials had serious deficiencies.

Relevance to clinical practice.  This study showed that there was no adequate written patient educational material at the clinics. This deficiency in written educational materials could be eliminated by having them prepared by health professionals in accordance with guidebooks and taking the target group into account.
Attitudes toward dementia‐related aggression among staff in Japanese aged care settings
Authors: Nakahira Miwa , Moyle Wendy , Creedy Debra , Hitomi Hiroe
Published: August 2010

Aim and objective.  This study investigated attitudes of Japanese aged care staff toward aggression by people with dementia. Relationships between staff attitudes, professional characteristics and clinical practice were explored.

Background.  Aggressive behaviour is often demonstrated by people with dementia and may be influenced by many factors including an inability by the individual to appropriately express their needs, difficulties with assessment, as well as organisational and practice issues.

Design.  Survey.

Method.  Twenty‐seven facilities/organisations located in the western and middle parts of Japan were surveyed. Staff (n = 675) employed in these facilities provided personal and professional information and completed the Attitudes Towards Aggression Scale.

Results.  Staff who were older, had more clinical experience, higher education and/or a higher position reported more positive attitudes towards patient aggression. Staff with negative attitudes towards patients who are aggressive reported using chemical and/or physical restraint more often than staff with positive attitudes.

Conclusions.  Dementia education as well as restraint policy will be useful in addressing negative staff attitudes, in particular it may help to reverse the myth that restraint is necessary for staff protection. Furthermore, staff counseling may help to reduce stressors and to change staff negative attitudes towards people with dementia who display aggression.

Relevance to clinical practice.  The findings show that negative staff attitudes may adversely affect clinical decision making and patient care. Measuring attitudes can identify areas requiring education or skill development and enable changes in attitudes to be monitored over time.
Pre‐ and postpartum levels of childbirth fear and the relationship to birth outcomes in a cohort of Australian women
Authors: Fenwick Jennifer , Gamble Jenny , Nathan Elizabeth , Bayes Sara , Hauck Yvonne
Published: August 2010

Aim.  To investigate pre‐ and postpartum levels of childbirth fear in a cohort of childbearing women and explore the relationship to birth outcomes.

Background.  While results are mixed, there is evidence that fear of childbirth is associated with mode of birth. Limited theoretical work around childbirth fear has been undertaken with Australian women.

Design.  A prospective correlation design.

Method.  Women (n = 401) completed the Wijma Delivery Expectancy/Experience Questionnaire (W‐DEQ) version A at 36 weeks gestation, with 243 (61%) women also completing version B at six weeks postpartum. Scores were summarised with means and standard deviations. Content analysis of the free statements identified nine issues of concern.

Results.  Twenty‐six per cent of pregnant women reported low levels of childbirth fear, 48% were moderately fearful and 26% were highly fearful. Fear decreased after birth for those women in the high antenatal fear group, however surgical intervention at birth (n = 238, anova, F1,230 = 12·39, p = 0·001) and suspected fetal compromise (F1,230 = 4·33, p = 0·039) increased levels of postpartum fear. Univariately, high antenatal fear was associated with emergency caesarean delivery (n = 324, Wald 5·05, p = 0·025) however after adjustment for nulliparity and fetal compromise the association disappeared. Australian‐born women were more likely to report higher levels of fear and experience higher rates of caesarean section than participants of non‐Australian origin.

Conclusions.  Results support those from earlier studies in showing that nulliparous women experience more fear than parous women before birth and that there is no difference in levels of postpartum fear between these two groups. Fear levels were higher in Australian women when compared to a Swedish sample.

Relevance to clinical practice.  The results of this study add to our preliminary understanding of the phenomena of childbirth fear within an Australian context and are particularly useful in profiling women for whom secondary fear of childbirth is more likely to occur.
Living with amyotrophic lateral sclerosis/motor neurone disease (ALS/MND): decision‐making about ‘ongoing change and adaptation’
Authors: King Susan J , Duke Maxine M , O’Connor Barrie A
Published: August 2010

Aims and objectives.  To present a model that explicates the dimensions of change and adaptation as revealed by people who are diagnosed and live with amyotrophic lateral sclerosis/motor neurone disease.

Background.  Most research about amyotrophic lateral sclerosis/motor neurone disease is medically focused on cause and cure for the illness. Although psychological studies have sought to understand the illness experience through questionnaires, little is known about the experience of living with amyotrophic lateral sclerosis/motor neurone disease as described by people with the disease.

Design.  A grounded theory method of simultaneous data collection and constant comparative analysis was chosen for the conduct of this study.

Methods.  Data collection involved in‐depth interviews, electronic correspondence, field notes, as well as stories, prose, songs and photographs important to participants. QSR NVivo 2® software was used to manage the data and modelling used to illustrate concepts.

Findings.  Participants used a cyclic, decision‐making pattern about ‘ongoing change and adaptation’ as they lived with the disease. This pattern formed the basis of the model that is presented in this paper.

Conclusion.  The lives of people living with amyotrophic lateral sclerosis/motor neurone disease revolve around the need to make decisions about how to live with the disease progression and their deteriorating abilities. Life decisions were negotiated by participants to maintain a sense of self and well‐being in the face of change.

Relevance to clinical practice.  The ‘ongoing change and adaptation’ model is a framework that can guide practitioners to understand the decision‐making processes of people living with amyotrophic lateral sclerosis/motor neurone disease. Such understanding will enhance caring and promote models of care that are person‐centred. The model may also have relevance for people with other life limiting diseases and their care.
Nurses values, attitudes and behaviour related to falls prevention
Authors: Dempsey Jennifer
Published: August 2010

Aim.  To test changes in adherence to nurses’ falls prevention work resulting from improving attitudes and ownership of practice.

Background.  Workforce surveys indicate that nurses leave nursing because they cannot deliver the care they value. When challenged why, nurses claim no power of decision‐making or authority to change their work with dissatisfaction and disengagement with work ensuing. Nurses espouse ‘caring’ but are observed taking risks with patients’ safety reflecting poor congruence between values and behaviours. Attitudes and decision‐making involvement are factors that influence work behaviours. Hence, increased adherence should be achieved by improving nurses’ attitudes through active decision‐making surrounding practice.

Design.  Mixed methods study.

Methods.  Mixed methods were employed during 2004 by surveying attitudes (self‐esteem, professional values and work satisfaction) before and after re‐engineering nurses’ work using practice development (PD) to gain time to spend in prevention work. Practice behaviour was observed and measured at intervals during the study.

Results.  Initially, nurses had good self‐esteem and professional values but were not satisfied with their work. Following the PD, self‐esteem and professional values were unaffected; however, nurses expressed increased sense of ownership and greater satisfaction. Nurses were observed to engage in more prevention work. More effective ways of assessing and communicating risk and monitoring nurses’ performance of prevention work were created and evaluated. Patients’ environments were made safer and more patient‐centred.

Conclusion.  Manipulation of attitudes and values is not warranted if attitudes and values are good. However, participation in work‐related decision‐making engages practitioners and leads to greater congruence between values and behaviour. Recommendations include promoting reflection and action to achieve cultural change and person‐centred care.

Relevance to clinical practice.  This study is relevant to international readership as adds to what is known about nurses’ practice behaviours related to falls prevention and will assist others when designing and implementing programs that address patient safety and optimise nurses’ adherence.
Effect of Trimebutine on Postprandial Colonic Motor Activity in Healthy Subjects and Patients with Irritable Bowel Syndrome
Authors: Shannon S. , Hollingsworth J. , Cook I. J. , Collins S. M.
Published: August 2010

We examined the effect of orally administered trimebutine maleate (200 mg) on postprandial motor activity measured manometrically in the sigmoid colon of 11 healthy subjects and nine patients with constipation‐predominant irritable bowel syndrome (IBS) in a double‐blind, placebo·controlled trial. Eight normal subjects showed increased motor activity following the meal after placebo, with a mean increase of 21.9%± 4.5%. Seven IBS patients showed increased motor activity after placebo and the meal, with a mean increase of 49.1 % that was significantly greater than that seen in healthy subjects. Following trimebutine, the mean postprandial increase in normal subjects was 23.9%± 12.0%, a value not significantly different from placebo. In contrast, in patients with IBS, following trimebutine ingestion the mean postprandial increase was 28.9%± 5.9%, a value significantly less than placebo response in that group, but not different from that observed in normal subjects after placebo. We conclude that orally administered trimebutine has no effect on postprandial sigmoid motor activity in normal subjects, but attenuates the increase observed in patients with constipation‐predominant IBS. The results also illustrate the heterogeneous nature of postprandial motor responses in healthy subjects and patients with IBS.
Neuropeptide Y Inhibits the Migrating Myoelectric Complex and Delays Small Intestinal Transit in Rats
Authors: Hellström Per M. , Johansson Catja
Published: August 2010

The effect of neuropeptide Y (NPY) on myoelectric activity of the small intestine was related to transit of a radioactive marker in fasted conscious rats. Myoelectric activity was recorded with bipolar electrodes implanted 5, 20, and 35 em distal to pylorus. A radioactive marker was administered luminally in the duodenum immediately after an activity front of a migrating myoelectric complex (MMC) had passed the first recording site. Intravenous infusion of NPY (50–100 pmol kg−1 min −1) did not affect the MMC in the duodenum but interrupted its distal propagation and inhibited spiking in the jejunum. At higher doses, NPY (200–800 pmol kg−1 min−1) abolished the MMC at all recording sites. Effects of NPY on myoelectric activity were not prevented by guanethidine, phentolamine, propranolol, or naloxone. The effects of NPY on myoelectric activity corresponded to a dose‐related slowing of transit of the marker. In controls, the peak of the marker was propagated ahead of the activity front over the three recording sites. NPY (100 pmol kg−1 min−1) slowed transit, with the peak of the marker proximal to the third electrode site. NPY (400 pmol kg−1 min−1) further delayed transit, with the peak of the marker proximal to the second electrode site. We conclude that the activity front of the MMC exerts a high propulsive capacity. NPY produced a dose‐related nonadrenergic inhibition of the intestinal myoelectric activity, which may account for a delayed transit of intestinal contents.
Effects of Cholera Toxin on Small Intestinal Motor Activity in the Fasted State
Authors: Cowles Verne E. , Sarna Sushil K.
Published: August 2010

We sought to determine the effect of cholera toxin on small intestinal motor activity in the fasted state and relate it to secretion in conscious dogs. Motor activity was recorded by strain gauge force transducers and secretion was measured by diverting it to the outside through a two‐way cannula. Inoculation of the study segment with cholera toxin resulted in a 10‐fold increase in fluid output by 120 minutes postinjection. At the same time that fluid output increased Significantly changes in fasting motor activity occurred. The cycle length of the migrating motor complex was significantly reduced, the percentage of phase II activity was significantly increased, and migrating clustered contractions were inhibited. Perfusion of the study segment by a nonabsorbable electrolyte solution at a rate similar to the rate of secretion induced by cholera toxin did not change the cycle length of migrating motor complexes, but the percentage of phase II activity was significantly increased as with cholera toxin, and migrating clustered contractions were inhibited. The reduction in the cycle length of migrating motor complexes seems to be a direct effect of cholera toxin on the gut wall while the increase in percentage of phase II activity and inhibition of migrating clustered contractions appear to be indirect effects due to fluid accumulation.
Brainstem Viral‐like Encephalitis as a Possible Cause of a Gastroduodenal Motility Disorder: A Case Report
Authors: Bortolotti M. , Mattioli S. , Alampi G. , Giangaspero G. , Barbara L.
Published: August 2010

The case of a 36‐year‐old caucasiun woman who suffered for many years from gastric retention and duodenogastric reflux due to gastroduodenal motor dysfunction resistant to therapy with prokinetic drugs is described. As the patient died suddenly of an unexplained cardiocirculatory collapse a few hours after a low‐risk operation, an autopsy examination was carried out to clarify the cause of death. No alterations were found in the heart, lungs, and central nervous system with the exception of a subacute viral‐like brainstem encephalitis involving the dorsal motor nucleus of the nervus vagus, the nucleus XII, the nucleus tractus solitaruis, and the nucleus ambiguus. A clinico‐pathologic correlate between the clinical alterations and the lesions of the brainstem centers, which modulate gastrointestinal and cardiovascular functions, is surmised.
Analysis of Spontaneous Gastroesophageal Reflux and Esophageal Acid Clearance in Patients with Reflux Esophagitis
Authors: Dodds Wylie J. , Kahrilas Peter J. , Dent John , Hogan Walter J. , Kern Mark K. , Arndorfer Ronald C.
Published: August 2010

To characterize gastroesophageal reflux episodes and esophageal acid clearance in patients with reflux esophagitis, we obtained 12‐hour overnight esophageal pH and manometry recordings in 20 patients with macroscopic reflux esophagitis and in 15 healthy volunteers. Compared to the control subjects, the patients had less pressure in the lower esophageal sphincter (LES) and higher rates of reflux, acid clearance time, and esophageal acid exposure. However, many patients had normal values for one or more of these variables. Transient LES relaxation accounted for 96% of reflux episodes in control subjects and 60% in patients. The remaining 40% of reflux episodes in patients occurred as stress or free reflux. In the control subjects, only one reflux episode occurred during estimated sleep. Of 22 reflux episodes during estimated sleep in patients, most were associated with low basal LES pressure. During esophageal acid clearance, the major esophageal motor event was swallow‐induced peristalsis rather than secondary peristalsis. We conclude that esophagitis patients have lower LES pressures, more reflux episodes, impaired esophageal acid clearance, and more esophageal exposure to acid than control subjects. Individual patients, however, exhibit heterogeneous abnormalities with respect to these variables. Transient LES relaxation is the major mechanism of gastroesophageal reflux in both patients and healthy subjects.
Effect of 5‐Hydroxytryptamine on Gastrointestinal Contractile Activity in Conscious Dogs
Authors: Iwanaga Yuji , Mizumoto Akiyoshi , Itoh Zen
Published: August 2010

The effect of intravenous infusion of 5‐hydroxytryptamine (5‐HT) on gastrointestinal contractile activity was studied in conscious dogs during the digestive and interdigestive states. It was found that 30 to 300 μg/kg per hour of 5‐HT induced phasic contractions mainly in the gastric antrum, duodenum, jejunum, and mid‐intestine. However, when doses greater than 100 μg/kg per hour were used, a stimulatory effect was seen in the ileum and colon. The dose‐dependent stimulatory effect of 5‐HT on gastrointestinal motor activity was observed in both the frequency and amplitude of contractions. Atropine‐resistant 5‐HT‐induced contractions in the stomach were completely inhibited by methysergide. This fact strongly suggests the existence of 5‐HT receptor on the smooth muscle. The stimulatory effect of 5‐HT given intravenously quickly disappeared with the cessation of infusion. No significant side effects such as nausea, vomiting, diarrhea, or other symptoms suggesting abdominal pain were observed during or after the intravenous infusion of 5‐HT in doses between 10 and 300 μg/kg per hour in any of the dogs.
Variations in Gastric Tone Associated with Duodenal Motor Events After Activation of Central Emetic Mechanisms in the Dog
Authors: De Ponti Fabrizio , Malagelada Juan‐R. , Azpiroz Fernando , Yaksh Tony L. , Thomforde George M.
Published: August 2010

To define the variations in gastric tone associated with the intestinal motor correlates of vomiting, we studied the effects of intracerebroventricular pharmacological manipulation in four fasting, conscious dogs with an injection catheter implanted into the fourth cerebral ventricle. Simultaneous monitoring of gastric tone and duodenal motility allowed us to study the correlation between gastric and duodenal motor events. We compared the effects of i.c.v. morphine (0.1 to 1 μLg/kg), apomorphine (0.003 to 0.03 (μg/kg), and the α2‐adrenoceptor agonist ST91 (0.1 to 1 μg/kg). These agonists, by the i.c.v. route all induced gastric relaxation accompanied by a retrograde power contraction in the duodenum and, at the highest doses, emesis; subsequently, a burst of intense phasic pressure activity developed in the duodenum. However, at a dose that was fully effective i.c.v., they had no effect when given intravenously. Naloxone or domperidone, at doses that had no effect per se, blocked the effects of morphine and apomorphine, respectively, except for a residual gastric relaxation. Idazoxan failed to block the effects of ST91. We conclude that a common pattern of motor events is triggered in the upper gut by different drugs by activation of receptors involved in the mechanism of vomiting and probably located in the central nervous system, and that the effects of morphine and apomorphine are mediated respectively by opioid and dopamine receptors.
Neural Contribution to Interdigestive Lower Esophageal Sphincter Pressure Phenomena in the Conscious Opossum
Authors: Blank Ellen L. , Holloway Richard H. , Dodds Wylie J. , Layman Rick D. , Sarna Sushil K. , Hogan Walter J.
Published: August 2010

The genesis of lower esophageal sphincter (LES) pressure in anesthetized opossums is a myogenic phenomenon without excitatory neural input. The mechanism responsible for generating phasic LES pressure phenomena in unanesthetized opossums, however, is not established. In this study, we evaluated the effects of potential pharmacological antagonists on LES pressure phenomena in unanesthetized opossums. We also compared LES responses to pharmacological excitatory agonists in anesthetized and unanesthetized animals. In awake animals the LES exhibited substantial tone as well as characteristic phasic activity. The tonic, or basal, LES pressure did not change during cycling of the migratory motor complex (MMC). However, atropine, 4‐diphenylacetoxy‐N‐methylpiperidine methiodide, and hexamethonium abolished the phasic, MMC‐related LES contractions while having no effect on basal pressure. Pirenzepine, prazosin, propranolol, pyrdamine, naloxone, and haloperidol did not affect either phasic or tonic LES pressure phenomena. Anesthesia substantially reduced the excitatory LES response to motilin but not to bethanechol, cholecystokinin‐octapeptide, pentagastrin, or phenylephrine. The results suggest that phasic LES contractions related to the MMC cycle are mediated by postganglionic cholinergic nerves with nicotinic ganglionic transmission. Basal LES tone, however, is maintained by a myogenic phenomenon. Anesthesia reduces excitatory LES responses induced by motilin, which acts via excitatory nerves, but has no effect on excitatory responses induced by agents that act mainly or exclusively on LES smooth muscle.
Involvement of 5‐Hydroxytryptamine in Canine Intestinal Motility Patterns
Authors: Davidson H. I. , Pilot M.‐A. , Thompson H. H.
Published: August 2010

Fasting activity seen as migrating myoelectric complexes and postprandial activity was recorded from eight conscious dogs with monopolar electrodes implanted on the serosa of the small bowel. A basal period was recorded, after which the 5‐hydroxytryptamine (5‐HT) antagonists methysergide, ketanserin, ICS 205–930, cyproheptadine, or MDL 72222 were administered by intravenous infusion. In other fasted experiments the same antagonists were administered in combination with a 5‐HT infusion. Ketanserin did not change the fed or fasted pattern in the intestine. Methysergide induced irregular spiking activity at all electrode sites in both preprandial and postprandial experiments which continued to the end of recording. Cyproheptadine prevented the distal propagation of phase III of the complex beyond the jejunum. Antagonists of the 5‐HT3receptor abolished phase II of the complex in some experiments. In postprandial experiments these antagonists increased the spiking activity recorded. 5‐HT itself produced irregular spiking, which in the proximal electrodes only was reduced by concurrent ketanserin administration. These data indicate a role for endogenous 5‐HT in the production of phase II of the migrating myoelectric complex and in its distal migration. The stimulatory action of 5‐HT in the proximal intestine is mediated by 5‐HT2receptors. Distally 5‐HT3receptors can play an inhibitory role in the contractile response.
Influence of Selective α‐ and β‐Adrenoceptor Antagonists on the Control of Motor Activity and Transmural Potential Differences in the Rabbit Ileum in Vitro
Authors: Greenwood Beverley , Davison J. S. , Dodds W. J.
Published: August 2010

Although the sympathetic nervous system influences intestinal motility and intestinal fluid and electrolyte transport, the role of sympathetic nerves in the relationship between the two processes has not been characterized. We investigated the effect of sympathetic nerve stimulation of intestinal function by monitoring concurrently predominantly longitudinal smooth muscle activity and transmural potential difference as an on‐line marker of intestinal ion transport. In a segment of rabbit small intestine in vitro, perivascular nerve stimulation inhibits spontaneous phasic motor activity and reduces transmural potential difference, which reflects enhanced absorption of fluids and electrolytes. The aim of this study was to investigate the particular adrenoceptors involved in both the smooth muscle and epithelial responses. Using the selective antagonists for the α1‐(prazonsin), α2‐(idazoxan), β1‐(atenolol), and β2‐adrenoceptors (butoxamine), we demonstrated that the enhanced fluid absorption, as shown by a fall in transmural potential difference, is α‐mediated with both α1‐and α2‐adrenoceptors being involved. However, there was considerable variation with regard to the type of α‐adrenoceptor subtype exerting the dominant effect. The sympathetically induced loss of spontaneous smooth muscle motor activity was found to be predominantly β1‐mediated, with the remainder of the response involving β2‐adrenoceptors.
Effect of Acetylcysteine on Intestinal Smooth Muscle after Small Bowel Bypass in Rats
Authors: Weisbrodt Norman W. , Green Gary M. , Belloso Raphael M. , Biskin Lawrence C. , Dudrick Stanley J.
Published: August 2010

Transit through the bypassed intestine is initially depressed in rats that have 70% of their jejunoileum bypassed. In this study, the influence of intraluminal infusion of the mucolytic N‐acetyl‐L‐cysteine on the depressed transit was determined. Beginning on the first postoperative day, the bypassed intestines were infused continuously with either saline or a 6% solution of acetylcysteine. In one group of animals, transit was determined on the third day after operation. In another group, segments of intestine were evaluated morphometrically on the twelfth day. Transit rates in bypassed intestines of those animals infused with acetylcysteine were higher than those in bypassed intestines of animals infused with saline. Compared to saline infusion, acetylcysteine infusion resulted in the following structural changes in the bypassed intestine: decreases in the total cross‐sectional area of the gut, the wet weight and cross‐sectional area of the intestinal muscle, and the thickness of the circular muscle layer. These findings support the hypothesis that the reduced transit and muscular hypertrophy seen in the uninfused bypassed intestine of rats early after operation may be due to alterations in intestinal contents which include mucus.
Composite Synthesized Relaxation Oscillators: Application to Modeling of Colonic Electrical Control and Response Activity
Authors: Bardakjian Berj L. , Sarna Sushil K. , Diamant Nicholas E.
Published: August 2010

A composite synthesized relaxation oscillator (SRO), whose output exhibits two types of interrelated rhythmic activities, is proposed. A slow rhythmic activity is present at all times, and it controls the appearance of a faster bursting activity that is not always present. The second‐order SRO dynamics for producing omnipresent and labile rhythmic activities are generalized as fourth‐order composite SRO dynamics for producing a composite rhythmic activity. To illustrate the relevance of this composite SRO to gastrointestinal electrical activities, a population of coupled SROs, which has been previously used to model colonic electrical control activity, is generalized to represent a population of coupled composite SROs to model both electrical control and response activities in the colon.
Effects of an Intestinal Smooth Muscle Calcium Channel Blocker (Pinaverium Bromide) on Colonie Transit Time in Humans
Authors: Froguel E. , Chaussade S. , Roche H. , Fallet M. , Couturier D. , Guerre J.
Published: August 2010

Pinaverium bromide, a calcium channel blocker, is often used in the treatment of the irritable bowel syndrome. Colonie transit time (CTT) was evaluated by a simplified method using radiopaque markers in 19 healthy volunteers during 2 weeks of treatment with pinaverium bromide (50 mg three times a day) or placebo according to a double‐blind crossover design. Pinaverium bromide significantly (p < .05) accelerated total CTT (30.2 ± 4.6 h, mean ± SE) compared with the placebo (38.2 ± 3.7 h). The decrease in CTT was related to accelerated transit in the descending and rectosigmoid areas of the colon (21 ± 4.5 vs. 30 ± 3.9 h, p < .05). CTT in the ascending colon was not significantly modified (9.2 ± 2.7 as compared with 9.5 ± 2.3 h). Stool frequency was not significantly increased by pinaverium bromide. These results suggest that pinaverium bromide might be effective in idiopathic constipation with slow CTT in the descending or rectosigmoid areas of the large bowel. The measurement of CTT is an easy and useful method for investigating the effects of drugs on colonie motility.
Effect of Intraesophageal Electrode Position on Signal Amplitude of the Crural Diaphragm Electromyogram
Authors: Fisher Michael J. , Mittal Ravinder K.
Published: August 2010

We studied the effect of electrode position relative to the lower esophageal sphincter (LES) on the crural diaphragm electromyogram (EMG) recording in 15 healthy human subjects. Three coil electrodes, each 1 cm in axial length and spaced 1 cm apart, were positioned on the distal 5 cm of a 6‐cm‐long Dent sleeve device. Bipolar EMG signals were recorded simultaneously from proximal and distal pairs of electrodes during spontaneous respiration, maximum inspiration with open airway, and maximum inspiration with closed airway. The catheter was positioned so that the side hole at the proximal margin of the sleeve recorded esophageal pressure just above the upper end of the LES. During spontaneous inspiration, the amplitude of the proximal diaphragm EMG signal was significantly higher than the distal. There was a significant difference in the amplitude of the two diaphragm EMG signals during maximum inspiration with open airway, and nearly significant differences in the two EMG signals during maximum inspiration with closed airway. We found that electrode position strongly influences the amplitude of the crural diaphragm EMG signals as measured by intraesophageal electrodes. Assessment of the crural diaphragm EMG with only one pair of electrodes may underestimate the signal amplitude.
Small Intestinal Manometric Studies in Patients with Familial Visceral Myopathies
Authors: Anuras Sinn , Anuras Jitra , Bozeman Terri
Published: August 2010

We studied jejunal manometry on 10 patients with type 1 familial visceral myopathy (FVM), and one patient each with types II and III. Two patients of type I and both patients of types II and III had intestinal pseudo‐obstruction syndrome. The record was obtained in each patient for 4 to 5 hours during fasting, and 1 hour after feeding. In type I FVM, migrating motor complexes were present in six and absent in four patients. In these four patients (two with intestinal pseudo‐obstruction syndrome) with absent migrating motor complexes, there was infrequent low‐amplitude contractions during fasting, and after feeding. In six patients with migrating motor complexes, the motility indices of phases 2, 3, and fed period were 59%, 49%, and 24% of those of control subjects, respectively, and the frequency of contractions of phases 2, 3 and the fed period were 70%, 79%, and 32% of those of control subjects, respectively. In both patients with types II and III FVM, only infrequent low‐amplitude contractions were recorded during fasting and after feeding. We concluded that intestinal contractions in patients with familial visceral myopathies were weak, and the weakness was more severe in patients with intestinal pseudo‐obstruction syndrome.
Interpretation of Postprandial Breath Hydrogen Excretion in Relation to Small Bowel Transit and Ileocecal Flow Patterns of a Radiolabeled Solid Meal in Man
Authors: Howard P. J. , Lazarus C. , Maisey M. N. , Dowling R. H.
Published: August 2010

Carbohydrate entering the cecum is fermented by bacteria to produce hydrogen (H2), which is excreted in the breath. The time interval between liquid meal ingestion and the “late onset” rise in breath H2 excretion is often used as an index of mouth‐to‐cecum transit time. After ingesting solid meals, however, the timing of onset of this “late” rise is difficult to determine because of erratic postprandial breath H2 patterns. Using a test meal containing both an unabsorbable carbohydrate (as a H2 source) and 99mTc‐labeled bran for radionuclide scanning studies, we were able to compare the pattern of breath H2 excretion with the pattern of entry of the isotopic label into the cecum. Repeated increases in breath H2 excretion were related, both in timing and amount, to the intermittent arrival of isotope in the cecum, showing that the entry of isotope into the cecum was periodic, rather than continuous. This information was used to define criteria for estimating mouth‐to‐cecum transit of a solid carbohydrate meal.
Actomyosin, Collagen, and Succinate Dehydrogenase Determinations in Opossum Esophageal Muscles
Authors: Bowers Rebecca L. , Dubinsky William P. , Weisbrodt Norman W.
Published: August 2010

The contractile activities of the lower esophageal sphincter (LES), esophageal body smooth muscle (SM), and esophageal body striated muscle (ST) of the opossum differ in their dependence on oxygen. One possible explanation for this difference in oxygen dependence is that the muscles differ in their oxidative capacities. The purpose of this study was to estimate the oxidative. capacity of these muscles by measuring the activity of succinate dehydrogenase (SDH). Since the muscles are structurally as well as functionally distinct, we also determined the amount of actin, myosin, collagen, and total protein in the tissues. LES contained less total protein and more collagen than SM and ST. The actin contents per unit of total protein of all three tissues were similar. The myosin contents and the actin: myosin ratios, however, were significantly different among all three muscles. The interpretation of the values of the SDH activity depended on the manner in which the data were expressed. When SDH activity was expressed relative to the tissue content of myosin, the values were different among all three muscles. These findings support the hypothesis that there is biochemical variability in these three esophageal muscles that may account in, part for their differences in contractile behavior.
Factors in the Control of Interdigestive and Postprandial Myoelectric Patterns of Canine Jejunoileum: Role of Extrinsic and Intrinsic Nerves
Authors: Sarr Michael G. , Duenes Judith A. , Zinsmeister Alan R.
Published: August 2010

Our aim was to determine the roles of extrinsic and intrinsic (enteric) neural continuity to the jejunoileum in control of postprandial and fasting motility patterns. Four groups of dogs were prepared: control, neurally intact; intrinsic transection, distal duodenal transection to disrupt intrinsic myoneural continuity with jejunum; extrinsic transection, transection of all extrinsic nerves to jejunoileum; and intrinsic/extrinsic transection, disruption of both intrinsic myoneural and extrinsic neural continuity to jejunoileum. Duodenal and jejunal electrodes were placed to monitor motility. After 2 weeks, the dogs were studied while fasting, after meals, and during intravenous infusions of cholecystokinin octapeptide at 0.5μg/(kg · h) and pentagastrin at 2μg/(kg · h). During fasting, although the migrating motor complex (MMC) occurred in each region, coordination between duodenum and jejunoileum was disrupted in intrinsic/extrinsic transection dogs, but only partially in intrinsic transection dogs. Small meals (50 g of liver) interrupted the duodenal MMC in all groups and the jejunoileal MMC only in control dogs. A larger (500‐g) meal disrupted the MMC in both regions for comparable durations in all groups. Cholecystokinin octapeptide and pentagastrin inhibited the MMC in duodenum and jejunoileum in all groups. Both intrinsic myoneural and extrinsic neural continuity play a role in regional coordination of interdigestive and digestive gut motility. Both hormonal and neural factors (central, enteric) participate in the regulation of onset of postprandial motor patterns.
Antagonism of Stress‐Induced Gastric Motor Alteration and Plasma Cortisol Release by Fedotozine (JO 1196) in Dogs
Authors: Gué M. , Junien J. L. , Pascaud X. , Buéno L.
Published: August 2010

The effects of fedotozine (a new dimethyl propylamine derivative) on gastric motor inhibition and plasma cortisol increase induced by acoustic stress were investigated in fasted dogs fitted with strain‐gauge transducers on the antrum and proximal jejunum and an implanted jugular catheter. Stress was induced by 1 hour of music (≤90 dB) played through earphones. Starting 40 to 50 minutes after the last migrating motor complex (MMC), acoustic stress delayed by 131% the next gastric MMC, whereas intestinal motility was unaffected. Plasma cortisol increased (p < 0.05) by 516%, 30 minutes after the beginning of noise. The inhibition of gastric MMC as well as the hypercortisolemia induced by acoustic stress were reduced in a dose‐related manner or abolished by previous oral administration of fedotozine (0.1–1 mg/kg) but not by intravenous injection (0.1–0.5 mg/kg). The effect of fedotozine was abolished after previous intravenous treatment with MR 2266 (0.1 mg/kg). Only the motor effects were suppressed by naloxone (0.1 mg/kg i.v.), which induced a significant (p < 0.05) increase in plasma level. Bilateral truncal vagotomy, which suppressed the effects of acoustic stress on gastric motility but not on plasma cortisol, suppressed the antagonistic influence of fedotozine on hypercortisolemia. We conclude that fedotozine administered orally reduces both stress‐induced gastric motor alterations and hypercortisolemia, probably by acting directly on K receptors present in the intestinal wall that activate vagal afferent fibers interacting, at the central nervous system level, with factors responsible for the gastric and endocrine alterations induced by stress.
Effects of Neurotensin on Gastric Smooth Muscle of Dog and Guinea Pig
Authors: Mandrek Kurt , Milenov Kiril
Published: August 2010

Mechanical activity was recorded in muscle preparations isolated from different regions of dog and guinea pig stomach. Neurotensin (10−11 to 10−8 mol/liter) produced three types of responses in canine gastric muscle: a small activation of tone infundic strips and in longitudinal strips from corpus and antrum; a transient inhibition of the rhythmic activity in circular strips from corpus, antrum, and outer pylorus; and a strong activation in the strips from inner pylorus. In guinea pig gastric muscle strong tonic responses were observed in circular fundic muscle strips, whereas in all other preparations the responses were negligible. All these effects were insensitive to atropine, dimethpyrindene, and tetrodotoxin. The neurotensin effect on strips from guinea pig stomach was strongly reduced in the presence of indomethacin or cortisone and markedly potentiated in the presence of arachidonic acid or prostaglandin F2α. contrast, the excitatory effect of neurotensin on canine inner pylorus was potentiated during indomethacin treatment.
Response of the Human Gastrointestinal Tract to Erythromycin
Authors: Zara Gian‐Paolo , Qin Xin Yu , Pilot Marie‐Anne , Thompson Hilary , Maskell Jeff
Published: August 2010

Erythromycin has been shown to increase gastrointestinal motility in dogs when given in large doses, whereas small doses of the antibiotic elicit a premature migrating motor complex (MMC) in both dogs and humans. To study the effects of therapeutic doses of erythromycin in humans, erythromycin was given to 14 human volunteers either intravenously, 7 mg (kg · 30 min), or orally (500 mg) and pressure recordings were made from perfused or solid state catheters. Migrating motor complexes were counted before and after erythromycin administration. Intravenously administered erythromycin caused a large increase in the amplitude, duration, and frequency of gastric contractions whereas the small bowel appeared to be inhibited. No MMC was observed after the onset of the intravenous infusion. After oral administration of erythromycin the number of MMC increased significantly. Erythromycin caused side effects in 71% of subjects. In conclusion, at therapeutic doses erythromycin causes a disturbance of human upper gastrointestinal motility and can prove a useful tool in motility studies.
Effect of Electrical Anterior Sacral Nerve Root Stimulation on Pelvic Floor Function in Paraplegic Subjects
Authors: Binnie N. R. , Smith A. N. , Creasey G. H. , Edmond P.
Published: August 2010

The effect of the Brindley stimulator on pelvic floor function has been studied in seven paraplegic subjects by standard manometric, radiologic, and electrophysiologic methods. There was no difference in the maximum resting pressure in the anal canal between the stimulated group and paraplegic subjects without sacral stimulators acting as controls. The fall in pressure in response to the rectosphinteric reflex as a percentage of the original resting pressure was significantly less, indicating a proportional effect on the external sphincter. There was less descent of the pelvic floor at rest in the stimulated group, but no difference in the pudendoanal reflex latency, motor unit potential duration, or resting electromyogram activity of the external anal sphincter. The maximum resting pressure in the anal canal, the pudendoanal reflex response amplitude, and the external anal sphincter electromyogram activity increased, however, with the duration of the implant. The S4 root had the dominant effect on the pelvic floor, with decreasing effects from the S3 and S2 roots on the pressure and integrated electromyogram activity generated by the external anal sphincter. The anorectal angle had not changed at rest in the group with the stimulator, but S4 root stimulation made it more acute than S3 or S2 root stimulation. The results suggest profound effects of S4 anterior root stimulation on the pelvic floor with additional effects of S3 and S2 anterior roots on pelvic function.
Electric Field Model: An Alternative Mechanism for Cell‐to‐Cell Propagation in Cardiac Muscle and Smooth Muscle
Authors: Sperelakis Nicholas
Published: August 2010

Cardiac muscle and visceral smooth muscle are similar in some regards, in that both tissues are composed of relatively short individual cells that interact in some way to allow the spread of excitation over all or much of the tissue, bringing about a synchronized and nearly simultaneous contraction of the cells to subserve a specific physiologic function. A prevailing view is that these short muscle cells possess low‐resistance interconnections, which allows local‐circuit action current to flow readily from one cell to the next, thereby allowing the propagation of excitation over the entire tissue. The gap junctions, which are observed morphologically, are thought to contain numerous low‐resistance connections. However, gap junctions are not observed in hearts of lower vertebrates or in some visceral smooth muscles. Therefore, the questions arise of what their role is in propagation and whether an alternative mechanism for transfer of excitation from cell to cell might apply in some normal physiologic circumstances and in some pathophysiologic conditions. The case for such an alternative mechanism that is electrical in nature, but does not require low‐resistance connections, is presented here. The arguments in support of low‐resistance coupling in smooth muscle are provided by Alex Bortoff in his accompanying article.
Activity Fronts of Migrating Myoelectric Complex: Initiation by Luminal Bile Acids in Rat Small Intestine
Authors: Nilsson I. , Svenberg T. , Wallin B. , Hedenborg G. , Hellström P. M.
Published: August 2010

The aim of the present study was to investigate the possible role of bile in regulation of fasting small intestinal motility in the rat. Myoelectric activity was recorded by bipolar electrodes implanted in the jejunum, 15, 25, and 35 cm distal to the pylorus. After recording migrating myoelectric complexes (MMCs), total biliary drainage was performed by cannulating the bile duct of 15 rats. After biliary drainage for 267 (222–312) minutes (mean and 95% confidence interval), a characteristic continuous irregular spiking activity appeared at all recording sites. When continuous irregular spiking had persisted for 2 hours, a mixture of 20 mM taurocholic and 10 mM taurochenodeoxycholic acid was infused into the duodenum (0.5 μ/mol/min for 90 min) of seven rats. Bile acid infusion induced three to six activity fronts within 25 to 47 minutes in all animals. Maximal bile acid secretion in response to bile acid infusion was obtained about 1 hour after the last induced activity front, when the motility pattern had returned to irregular spiking. In eight rats with biliary drainage but without bile acid infusion, irregular spiking activity persisted for at least 10 hours. In sham‐operated rats, regular activity fronts started after 221 (146–296) minutes. Thus drainage of bile changes the motility pattern from MMC to continuous irregular spiking, while duodenal bile acid infusion after biliary drainage reinstates the MMC pattern in rat small intestine.