Type 1 diabetic patients with peripheral neuropathy have pan-enteric prolongation of gastrointestinal transit times and an altered caecal pH profile

AIMS/HYPOTHESIS

We hypothesised that type 1 diabetic patients with established diabetic sensorimotor polyneuropathy (DSPN) would have segmental and/or pan-enteric dysmotility in comparison to healthy age-matched controls. We aimed to investigate the co-relationships between gastrointestinal function, degree of DSPN and clinical symptoms.

METHODS

An observational comparison was made between 48 patients with DSPN (39 men, mean age 50 years, range 29-71 years), representing the baseline data of an ongoing clinical trial (representing a secondary analysis of baseline data collected from an ongoing double-blind randomised controlled trial investigating the neuroprotective effects of liraglutide) and 41 healthy participants (16 men, mean age 49 years, range 30-78) who underwent a standardised wireless motility capsule test to assess gastrointestinal transit. In patients, vibration thresholds, the Michigan Neuropathy Screening Instrument and Patient Assessment of Upper Gastrointestinal Symptom questionnaires were recorded.

RESULTS

Compared with healthy controls, patients showed prolonged gastric emptying (299 ± 289 vs 179 ± 49 min; p = 0.01), small bowel transit (289 ± 107 vs 224 ± 63 min; p = 0.001), colonic transit (2140, interquartile range [IQR] 1149-2799 min vs 1087, IQR 882-1650 min; p = 0.0001) and whole-gut transit time (2721, IQR 1196-3541 min vs 1475 (IQR 1278-2214) min; p < 0.0001). Patients also showed an increased fall in pH across the ileocaecal junction (-1.8 ± 0.4 vs -1.3 ± 0.4 pH; p < 0.0001), which was associated with prolonged colonic transit (r = 0.3, p = 0.001). Multivariable regression, controlling for sex, disease duration and glycaemic control, demonstrated an association between whole-gut transit time and total GCSI (p = 0.02).

CONCLUSIONS/INTERPRETATION

Pan-enteric prolongation of gastrointestinal transit times and a more acidic caecal pH, which may represent heightened caecal fermentation, are present in patients with type 1 diabetes. The potential implication of delayed gastrointestinal transit on the bioavailability of nutrition and on pharmacotherapeutic and glycaemic control warrants further investigation.

TRIAL REGISTRATION

EUDRA CT: 2013-004375-12.

Gastrointestinal Dysfunction in Patients with Duchenne Muscular Dystrophy

Background

In adult patients with Duchenne muscular dystrophy (DMD) life-threatening constipation has been reported. Since gastrointestinal function in DMD has not been rigorously studied we investigated objective and subjective manifestations of gastrointestinal disturbances in DMD patients.

Methods

In 33 patients with DMD, age 12–41 years, eating behavior and gastrointestinal symptoms were evaluated by questionnaires. Gastric emptying half time (T_1/2) and oro-cecal transit time (OCTT) were evaluated by analyzing ¹³CO₂ exhalation curves after ingestion of ¹³C labeled test meals. Colonic transit time (CTT) was measured by abdominal radiography following ingestion of radiopaque markers.

Results

The median (quartiles) T_1/2 was 187 (168, 220) minutes, the OCTT was 6.3 (5.0, 7.9) hours, both substantially longer than normal data (Goetze 2005, T_1/2: 107±10; Geypens 1999, OCTT 4.3±0.1 hours). The median CTT was 60 (48, 82) hours despite extensive use of laxative measures (Meier 1995, upper limit of normal: 60 hours). T_1/2 and OCTT did not correlate with symptoms evaluated by the Gastroparesis Cardinal Symptom Index (GCSI) (Spearman r = -0.3, p = 0.1; and r = -0.15, p = 0.4, respectively). CTT was not correlated with symptoms of constipation assessed by ROME III criteria (r = 0.12, p = 0.5).

Conclusions

DMD patients have a markedly disturbed gastrointestinal motor function. Since objective measures of impaired gastrointestinal transport are not correlated with symptoms of gastroparesis or constipation our findings suggest that measures assuring adequate intestinal transport should be taken independent of the patient’s perception in order to prevent potentially life threatening constipation, particularly in older DMD patients.

[Preliminary exploration on accurately preoperative evaluation of colonic lesions in slow transit constipation complicated with adult megacolon]

OBJECTIVE

To investigate the application value of colonic transit test (CTT) combined with anorectal manometry (ARM), barium enema (BE) and defecography (DFG) in accurately evaluating colonic lesions of slow transit constipation complicated with adult megacolon.

METHODS

Clinical data of 47 above patients admitted between October 2007 and February 2015 in the People's Hospital of Hunan Province were analyzed retrospectively. All the patients were examined with≥2 times of CTT combined with ARM and BE, and 42 cases received additional DFG at the same time, to evaluate colonic lesions before operation. Operative biopsy pathology was used as the standard. The sensitivity, specificity, positive predictive value(PPV) and negative predictive value(NPV) of positioning in the ascending colon and caecum, transverse colon and descending colon were calculated, and the consistency was represented by Kappa test(Kappa value≥0.75 indicates good consistency, meanwhile higher Kappa value indicates better consistency). The Heikkinen score was used to evaluate defecation function at postoperative 6 months.

RESULTS

The age of 47 patients was from 18 to 56 years old. Compared with intraoperative findings and biopsy pathology, the diagnostic coincidence rate was 89.4% by CTT combined with BE and DFG positioning, which suggested pathology-changed colonic segment locating in the ascending colon and cecum (n=12), transverse colon (n=26) and descending colon (n=9), while intraoperative findings and biopsy pathology suggested pathology-changed colonic segment locating in the ascending colon and cecum (n=11), transverse colon (n=23) and descending colon (n=13). The sensitivity was 88.3%, specificity 93.5%, PPV 92.1%, NPV 94.9% and Kappa value was 0.827(P<0.001). Procedures performed included segmental colectomy (n=8), subtotal colectomy (n=29), total colectomy (n=10). There was no serious complication during and after operation. Defecatory function was excellent in 24 cases (60.0%), good in 10 (25.0%), and moderate in 6 (15.0%) evaluated by Heikkinen score at postoperative 6 months. A total of 40 patients were followed up from 1 to 7 years (median 3 years) and there was no long-term diarrhea and recurrence of constipation or giant colon after operation.

CONCLUSION

Preoperative detection of CTT combined with ARM, BE and DFG in patients with slow transit constipation complicated with adult megacolon can make a more precise assessment of the extent of colonic lesions in advance, which has a good clinical predictive value.

[Focal nonspecific ileocecum inflammation: a follow-up study of 66 cases]

OBJECTIVE

To investigate the natural disease course of nonspecific ileocecum inflammation (FNICI) and the possibility of early diagnosis of Crohn's disease (CD).

METHODS

The patients with an established diagnosis of FNICI at our hospital in the past 4 years were retrospectively analyzed for clinical manifestations, endoscopical, readigraphic and histopathological findings and laboratory data. The patients were followed up regularly for their outcomes.

RESULTS

Our analysis included 66 patients with FNICI (with a male-to-female ratio of 34:32 and a mean age of 39 years old). The patients were followed up for 10.5 months on average, and 8 (12.1%) patients developed CD. Among these 8 patients, the initial endoscopic examination upon admission revealed ulcers involving the ileocecum valve, and biopsy results showed focal active chronic mucosal inflammation. Laboratory tests showed that the patients who finally developed CD had significantly higher erythrocyte sedimentation rate (P=0.013) and C reaction protein (P<0.01) than the patients who eventually had full recovery.

CONCLUSION

FNICI is a common lesion caused by multiple factors and has not specific endoscopic or histopathological features, which makes its definite diagnosis difficult. The patients with persistent ulcer and elevated erythrocyte sedimentation rate and C reactive protein should be closely followed up for early diagnosis of CD.

Cecal Ligation and Puncture Results in Long-Term Central Nervous System Myeloid Inflammation

Survivors of sepsis often experience long-term cognitive and functional decline. Previous studies utilizing lipopolysaccharide injection and cecal ligation and puncture in rodent models of sepsis have demonstrated changes in depressive-like behavior and learning and memory after sepsis, as well as evidence of myeloid inflammation and cytokine expression in the brain, but the long-term course of neuroinflammation after sepsis remains unclear. Here, we utilize cecal ligation and puncture with greater than 80% survival as a model of sepsis. We found that sepsis survivor mice demonstrate deficits in extinction of conditioned fear, but no acquisition of fear conditioning, nearly two months after sepsis. These cognitive changes occur in the absence of neuronal loss or changes in synaptic density in the hippocampus. Sepsis also resulted in infiltration of monocytes and neutrophils into the CNS at least two weeks after sepsis in a CCR2 independent manner. Cellular inflammation is accompanied by long-term expression of pro-inflammatory cytokine and chemokine genes, including TNFα and CCR2 ligands, in whole brain homogenates. Gene expression analysis of microglia revealed that while microglia do express anti-microbial genes and damage-associated molecular pattern molecules of the S100A family of genes at least 2 weeks after sepsis, they do not express the cytokines observed in whole brain homogenates. Our results indicate that in a naturalistic model of infection, sepsis results in long-term neuroinflammation, and that this sustained inflammation is likely due to interactions among multiple cell types, including resident microglia and peripherally derived myeloid cells.

Colonic transit in the empty colon after defunctioning ileostomy: do we really know what happens?

BACKGROUND

There is disagreement amongst surgeons about the use of oral mechanical bowel preparation (MBP) prior to low anterior resection with diverting ileostomy. Colonic transit in the early post-operative period is an important factor in determining the role of MBP, as propagation of any stool remaining in the defunctioned colon may exacerbate morbidity in the event of anastomotic leak. We studied colonic transit time in the first 7 days following low anterior resection with diverting ileostomy.

METHODS

We conducted a prospective observational study of patients with rectal cancer undergoing elective low anterior resection with diverting ileostomy in a tertiary colorectal unit. Twenty radio-opaque markers were inserted into the caecum via the distal limb of the loop ileostomy at surgery. Plain abdominal radiographs were taken on post-operative days 1, 3 and 5. The primary endpoint was passage of the markers to the neorectum. Data were collected on treatment, return of gastrointestinal function and complications.

RESULTS

Twenty-two patients (mean age 68.5 years; 18 males) participated in the study. In 20 patients, all markers remained in the right colon on day 7. Three markers were present in the left colon in one patient, and eight markers were present in the neorectum in another patient, on the seventh day.

CONCLUSIONS

Colonic transit may be abolished by the presence of diverting ileostomy. It should now be established whether clearance of the left colon alone, using enemas, is sufficient for patients undergoing low anterior resection, thus avoiding the morbidity associated with oral MBP.

[Non-steroidal anti-inflammatory drugs in the correction of experimental ulcerative colitis]

Non-steroidal anti-inflammatory drugs influence the electromyogram of smooth muscle of ileum, the cecum and the ascending portion of the colon in rats during ulcerative colitis was investigated. It was shown that COX-2 inhibitors normalized the electromotor activity of ileo-ascendo complex, lowered infiltration of round cells in mucous-submucosal tissue and blood flow.

Ileocecal valve dysfunction in small intestinal bacterial overgrowth: a pilot study

AIM

To explore whether patients with a defective ileocecal valve (ICV)/cecal distension reflex have small intestinal bacterial overgrowth.

METHODS

Using a colonoscope, under conscious sedation, the ICV was intubated and the colonoscope was placed within the terminal ileum (TI). A manometry catheter with 4 pressure channels, spaced 1 cm apart, was passed through the biopsy channel of the colonoscope into the TI. The colonoscope was slowly withdrawn from the TI while the manometry catheter was advanced. The catheter was placed across the ICV so that at least one pressure port was within the TI, ICV and the cecum respectively. Pressures were continuously measured during air insufflation into the cecum, under direct endoscopic visualization, in 19 volunteers. Air was insufflated to a maximum of 40 mmHg to prevent barotrauma. All subjects underwent lactulose breath testing one month after the colonoscopy. The results of the breath tests were compared with the results of the pressures within the ICV during air insufflation.

RESULTS

Nineteen subjects underwent colonoscopy with measurements of the ICV pressures after intubation of the ICV with a colonoscope. Initial baseline readings showed no statistical difference in the pressures of the TI and ICV, between subjects with positive lactulose breath tests and normal lactulose breath tests. The average peak ICV pressure during air insufflation into the cecum in subjects with normal lactulose breath tests was significantly higher than cecal pressures during air insufflation (49.33 ± 7.99 mmHg vs 16.40 ± 2.14 mmHg, P = 0.0011). The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflations in subjects with normal lactulose breath tests was significantly higher (280.72% ± 43.29% vs 100% ± 0%, P = 0.0006). The average peak ICV pressure during air insufflation into the cecum in subjects with positive lactulose breath tests was not significantly different than cecal pressures during air insufflation 21.23 ± 3.52 mmHg vs 16.10 ± 3.39 mmHg. The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflation was not significantly different 101.08% ± 7.96% vs 100% ± 0%. The total symptom score for subjects with normal lactulose breath tests and subjects with positive lactulose breath tests was not statistically different (13.30 ± 4.09 vs 24.14 ± 6.58). The ICV peak pressures during air insufflations were significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.005). The average percent difference of the area under the pressure curve in the ICV from cecum was significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.0012). Individuals with positive lactulose breath tests demonstrated symptom scores which were significantly higher for the following symptoms: not able to finish normal sized meal, feeling excessively full after meals, loss of appetite and bloating.

CONCLUSION

Compared to normal, subjects with a positive lactulose breath test have a defective ICV cecal distension reflex. These subjects also more commonly have higher symptom scores.

Determinants of accelerated small intestinal transit in alcohol-related chronic pancreatitis

Patients with chronic pancreatitis may have abnormal gastrointestinal transit, but the factors underlying these abnormalities are poorly understood. Gastrointestinal transit was assessed, in 40 male outpatients with alcohol-related chronic pancreatitis and 18 controls, by scintigraphy after a liquid meal labeled with (99m)technetium-phytate. Blood and urinary glucose, fecal fat excretion, nutritional status, and cardiovascular autonomic function were determined in all patients. The influence of diabetes mellitus, malabsorption, malnutrition, and autonomic neuropathy on abnormal gastrointestinal transit was assessed by univariate analysis and Bayesian multiple regression analysis. Accelerated gastrointestinal transit was found in 11 patients who showed abnormally rapid arrival of the meal marker to the cecum. Univariate and Bayesian analysis showed that diabetes mellitus and autonomic neuropathy had significant influences on rapid transit, which was not associated with either malabsorption or malnutrition. In conclusion, rapid gastrointestinal transit in patients with alcohol-related chronic pancreatitis is related to diabetes mellitus and autonomic neuropathy.

Pectin/Kollicoat SR30D isolated films for colonic delivery [I]: a comparison of normal and colitis-induced models to assess the efficiency of microbially triggered drug delivery

OBJECTIVES

The purpose of the study was to evaluate digestion of pectin/Kollicoat SR30D free films for colonic delivery in vitro and in vivo.

METHODS

Free films containing different ratios of pectin to Kollicoat SR30D were prepared by casting/solvent evaporation method. An in-vitro comparison of swelling, degradation and permeability of the free films was carried out in simulated colon fluids containing caecal contents from normal rats with colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) or oxazolone. A comparative in-vivo evaluation of degradation was also conducted in normal and colitis-induced model rats.

KEY FINDINGS

The pectin within the mixed films was susceptible to rat colonic bacterial enzymes. The extent of digestion correlated with the amount of pectin present within the film. In vitro, the swelling index, drug permeability and extent of film digestion in simulated colon fluids with caecal contents obtained from normal rats were higher than from TNBS- or oxazolone-induced model rats, whereas in-vivo degradation was similar in the three groups of rats. The pectin/Kollicoat SR30D free films were completely degraded in the colitis-induced rats.

CONCLUSIONS

Pectic/Kollicoat SR30D films may be useful as coatings to target delivery of drugs to the colon.

Comparative metagenomics reveals host specific metavirulomes and horizontal gene transfer elements in the chicken cecum microbiome

BACKGROUND

The complex microbiome of the ceca of chickens plays an important role in nutrient utilization, growth and well-being of these animals. Since we have a very limited understanding of the capabilities of most species present in the cecum, we investigated the role of the microbiome by comparative analyses of both the microbial community structure and functional gene content using random sample pyrosequencing. The overall goal of this study was to characterize the chicken cecal microbiome using a pathogen-free chicken and one that had been challenged with Campylobacter jejuni.

METHODOLOGY/PRINCIPAL FINDINGS

Comparative metagenomic pyrosequencing was used to generate 55,364,266 bases of random sampled pyrosequence data from two chicken cecal samples. SSU rDNA gene tags and environmental gene tags (EGTs) were identified using SEED subsystems-based annotations. The distribution of phylotypes and EGTs detected within each cecal sample were primarily from the Firmicutes, Bacteroidetes and Proteobacteria, consistent with previous SSU rDNA libraries of the chicken cecum. Carbohydrate metabolism and virulence genes are major components of the EGT content of both of these microbiomes. A comparison of the twelve major pathways in the SEED Virulence Subsystem (metavirulome) represented in the chicken cecum, mouse cecum and human fecal microbiomes showed that the metavirulomes differed between these microbiomes and the metavirulomes clustered by host environment. The chicken cecum microbiomes had the broadest range of EGTs within the SEED Conjugative Transposon Subsystem, however the mouse cecum microbiomes showed a greater abundance of EGTs in this subsystem. Gene assemblies (32 contigs) from one microbiome sample were predominately from the Bacteroidetes, and seven of these showed sequence similarity to transposases, whereas the remaining sequences were most similar to those from catabolic gene families.

CONCLUSION/SIGNIFICANCE

This analysis has demonstrated that mobile DNA elements are a major functional component of cecal microbiomes, thus contributing to horizontal gene transfer and functional microbiome evolution. Moreover, the metavirulomes of these microbiomes appear to associate by host environment. These data have implications for defining core and variable microbiome content in a host species. Furthermore, this suggests that the evolution of host specific metavirulomes is a contributing factor in disease resistance to zoonotic pathogens.

Orocecal transit time in patients with celiac disease from North India: a case control study

AIM

The mechanisms responsible for bowel disturbances in celiac disease are still unknown. Small bowel motor abnormalities may be involved in this pathological condition; however, there is no study addressing small bowel transit in patients of celiac disease from Northern India.

METHOD

The mouth-to-cecum transit time was studied in 80 celiac patients and 80 age and sex matched apparently healthy controls.

RESULTS

Orocecal transit time in celiac patients was significantly delayed being 180+/-10.6 minutes (Mean+/-SE) as compared to 105+/-12.4 minutes in apparently healthy controls.

CONCLUSION

This prolonged orocecal transit time could be due to impaired small bowel function (deranged motility) in patients with celiac disease.

Colonic response to food in constipation

OBJECTIVES

Colonic response to food is possibly abnormal in constipation.

METHODS

The colonic response to food was evaluated in 323 patients and 60 healthy subjects by following the movements of radiopaque markers after ingestion of a standard 1,000-cal test meal. Constipated patients were divided into four groups: one with a normal, and three with a delayed colorectal transit time. When the delay was found mainly in the ascending colon, the group was labeled as suffering from "colonic inertia". In "hindgut dysfunction", the delay was predominantly found in the descending colon, whereas the term "outlet obstruction" was reserved for constipated patients whose major site of delay was the rectosigmoid area. Colonic response to food was quantified by evaluating the variation of markers in a given abdominal region and the evolution of the geometric center on the entire plain film of the abdomen.

RESULTS

Emptying of the caecum-ascending colon and filling of the rectosigmoid area characterize the colonic response to food in healthy subjects. Constipated patients also filled the rectosigmoid, but different patterns were found in the colon. In constipated patients with transit in the normal range, there was a frequent (41%) absence of colonic response to food as compared to controls (13%) and constipated patients with delayed transit (p<0.0001). The response to food of patients with colonic inertia was similar to that of healthy subjects in terms of distal progression, but less marked. The hindgut dysfunction group emptied the entire left colon but failed to empty the caecum and ascending colon. In the outlet obstruction group, there was no distal progress of the geometric center after meal.

CONCLUSIONS

Abnormal colonic response to food is frequently found in constipated patients, with different patterns according to the type of constipation.

Acute colonic pseudo obstruction (Ogilvie's syndrome): case report

Ogilvie's syndrome was first described by Sir Heneage Ogilvie in 1948 and is a rare disorder comprising acute colonic pseudo obstruction (ACPO) with gross dilation of the caecum and right hemicolon (occasionally extending to the rectum) without an anatomic lesion that obstructs the aboral flow of intestinal contents. A sixty five year old female with ACPO, perforation and septic shock is presented. A retrospective confirmation of the diagnosis was made after surgery at which a grossly dilated caecum and colon were seen and a right hemicolectomy carried out. Preoperative radiological investigations had shown a dilated caecum with massive faecal loading of the colon.

CD40 BUT NOT CD154 KNOCKOUT MICE HAVE REDUCED INFLAMMATORY RESPONSE IN POLYMICROBIAL SEPSIS: A POTENTIAL ROLE FOR ESCHERICHIA COLI HEAT SHOCK PROTEIN 70 IN CD40-MEDIATED INFLAMMATION IN VIVO

The CD40-CD154 system controls various aspects of the host inflammatory response in models of cellular and humoral immunity. Recently, we described a role for CD40 in the innate immune response in polymicrobial sepsis. However, recent data suggests that CD40 maybe activated by CD154 or directly via bacterial heat shock protein (HSP) 70. Therefore, we decided to test the mechanism of CD40 activation in murine polymicrobial sepsis. Wild-type (WT), CD40, and CD154 underwent cecal ligation and puncture (CLP). Compared with WT mice, CD40 had improved survival in association with attenuated production of IL-12, TNF-alpha, and IL-6. In contrast, CD154 mice behaved similar to WT mice with regard to mortality and cytokine production. The differential response of CD40 and CD154 mice to CLP was not due to a general attenuated response to inflammatory stimuli, as all three strains had similar survival after LPS administration, and CD40 macrophages had normal production of IL-12 in response to lipopolysaccharide. In contrast, CD40 macrophages had attenuated IL-12 production in response to Escherichia coli HSP70 (DnaK). Furthermore, intraperitoneal administration of DnaK resulted in a 4-fold increase in IL-12 in WT mice, which was absent in CD40 mice. This data demonstrates CD154-independent CD40 activation in polymicrobial sepsis and suggests that bacterial HSP70 is capable of stimulating CD40 in vitro and in vivo.

Electromotor Activity of the Cecum and Ascending Colon: The Concept of ‘Individual Pacemakers’

BACKGROUND/AIMS

The cecum is described as differing anatomically from the ascending colon (AC); yet their similarity or difference in terms of motile activity has not been studied sufficiently. The cecum is separated from the AC by the cecocolonic junction (CCJ) which contains a cecocolonic sphincter. We assumed that the motile activity of the AC is different from that of the cecum and hypothesized that both the AC and the cecum might have different pacemakers which initiate the motile activity. This hypothesis was investigated in the current study.

METHODS

The study was performed in 10 subjects (mean age 41.6 +/- 12.8 SD years; 7 women) during the repair of huge abdominal incisional hernias. The electric activity was recorded from 2 monopolar electrodes applied each to the cecum, CCJ and AC. The CCJ was then anesthetized by xylocaine and the electric waves of the cecum, CCJ and AC were registered after 10 and 90 min. The test was repeated using normal saline instead of xylocaine.

RESULTS

Electric waves were recorded from the cecum, CCJ and AC in the form of monophasic pacesetter (PPs) and action potentials (APs). The PPs occurred regularly and the APs randomly. The frequency, amplitude and conduction velocity of the waves recorded from the CCJ and AC had higher readings than those from the cecum (p < 0.05). The CCJ and AC showed similar frequency and conduction velocity (p > 0.05). Ten minutes after CCJ anesthetization, electric waves were recorded from the cecum but not from the CCJ or AC; however, electric activity returned after 90 min. Saline injection did not affect the electric activity of the cecum, CCJ and AC.

CONCLUSION

The electric wave parameters of the cecum differed from those of the CCJ and AC, suggesting that the motile activity of the CCJ and AC is not a continuation of the motile activity of the cecum and that it might be evoked by 2 different pacemakers. The similarity in frequency and conduction velocity of electric waves of the CCJ and AC, however, most likely denotes that the AC waves are a continuation of those of the CCJ, and that both are evoked by the same pacemaker probably located in the CCJ. The higher amplitude of cecal waves might be due to the thicker cecal musculature compared to that of the AC.

Pan-colonic decrease in interstitial cells of Cajal in patients with slow transit constipation

BACKGROUND

Interstitial cells of Cajal (ICC) are required for normal intestinal motility. ICC are found throughout the human colon and are decreased in the sigmoid colon of patients with slow transit constipation.

AIMS

The aims of this study were to determine the normal distribution of ICC within the human colon and to determine if ICC are decreased throughout the colon in slow transit constipation.

PATIENTS

The caecum, ascending, transverse, and sigmoid colons from six patients with slow transit constipation and colonic tissue from patients with resected colon cancer were used for this study.

METHODS

ICC cells were identified with a polyclonal antibody to c-Kit, serial 0.5 microm sections were obtained by confocal microscopy, and three dimensional software was employed to reconstruct the entire thickness of the colonic muscularis propria and submucosa.

RESULTS

ICC were located within both the longitudinal and circular muscle layers. Two networks of ICC were identified, one in the myenteric plexus region and another, less defined network, in the submucosal border. Caecum, ascending colon, transverse colon, and sigmoid colon displayed similar ICC volumes. ICC volume was significantly lower in the slow transit constipation patients across all colonic regions.

CONCLUSIONS

The data suggest that ICC distribution is relatively uniform throughout the human colon and that decreased ICC volume is pan-colonic in idiopathic slow transit constipation.

Does endotoxin-activated complement alter myocellular sodium homeostasis during sepsis?

BACKGROUND

Inappropriate complement activation is closely related to tissue injury and organ dysfunction during systemic infection. It is not clear, however, if endotoxin-induced complement activation is responsible for changes in myocellular sodium homeostasis during sepsis.

METHODS

Rats underwent cecal ligation and puncture (CLP) or sham operation. Twenty-four hours after operation, fast-twitch extensor digitorum longus (EDL) muscles were isolated, incubated at 30 degrees C for 1 hour in Krebs-Henseleit buffer (KHB) (pH 7.4), and used to measure intracellular Na+ and K+ contents. Blood samples were collected to measure serum hemolytic complement activity and endotoxin levels. In addition, EDL muscles isolated from normal animals were incubated at 30 degrees C for 1 hour with zymosan-activated (10 mg/mL at 37 degrees C for 1 hour) rat sera, with lipopolysaccharide (LPS)-activated (LPS from Escherichia coli 055:B5, 10 or 200 microg/mL at 37 degrees C for 30 minutes) rat sera, with heat-inactivated (56 degrees C for 30 minutes) rat sera, with LPS (1 or 20 microg/mL), or in KHB. EDL muscles isolated from normal animals were also incubated with septic sera collected 6 or 24 hours after CLP with or without administration of soluble complement receptor type 1 (20 mg/kg, intraperitoneally). Myocellular Na+ and K+ contents ([Na+]i and [K+]i) were assayed using "washout" technique. Soluble C5b-9 complex levels in zymosan-activated or LPS-activated human sera were determined by enzyme-linked immunosorbent assay to evaluate the degree of complement activation induced by zymosan or LPS.

RESULTS

Myocellular [Na+]i and [Na+]i/[K+]i ratios increased significantly 24 hours after CLP as compared with sham operation and were associated with decreased serum hemolytic complement activity and increased serum endotoxin levels. Zymosan-activated rat sera at sublytic concentrations markedly increased [Na+]i and [Na+]i/[K+]i ratios in isolated EDL muscles relative to heat-inactivated rat sera. LPS-activated rat sera, however, did not alter these two indices. In addition, myocellular [Na+]i and [Na+]i/[K+]i ratios were equivalent among normal EDL muscles incubated with septic sera, soluble complement receptor type 1-treated septic sera, or KHB.

CONCLUSION

These results collectively suggest that polymicrobial sepsis, as produced by CLP, alters sodium homeostasis in fast-twitch skeletal muscles in association with changes in systemic complement activation and circulating endotoxin levels. Although endotoxin can activate the complement cascade, endotoxin-induced complement activation does not appear to be responsible for changes in myocellular sodium homeostasis observed during sepsis in rats.

Relationship between cytokine mRNA expression and organ damage following cecal ligation and puncture

AIM: To investigate the role of cytokine gene expression in organ damage at different tissue sites during sepsis.

METHODS: Male NIH mice were subjected to cecal ligation and puncture (CLP) or sham operation (Sham). Pro-inflammatory cytokine (TNFα, IL-1β and IL-6) and anti-inflammatory cytokine (IL-4) gene expression in the liver and lung tissue were assessed by RT-PCR. The permeability of microvascular and water content in the lungs and liver were also examined.

RESULTS: Significant increase in TNFα, IL-1β and IL-6 gene expression was observed at 3 and 12 h after CLP both in the liver and lungs (P < 0.01).The level of IL-4 gene expression was not changed after CLP in the lungs, but increased at 12 h after CLP (P < 0.01) in the liver tissue. Both the liver and lungs showed a significant increase in microcirculatory permeability at 12 h after CLP(P < 0.01), and the increase in the lungs was higher than that in the liver. The water mass fractions in the liver (P < 0.05) and lungs (P < 0.01) were increased after CLP, and the increase in the lungs happened earlier and more severely than that in the liver.

CONCLUSION: The inflammatory response in the liver and lungs was different during sepsis. At the early stage of sepsis, pro-inflammatory reaction dominates both in the liver and lungs. But at the later stage of sepsis, induction of compensatory anti-inflammatory response was seen in the liver but not in the lungs. This difference in situ activity may contribute to the different vulnerability of organ damage during sepsis. The strategy of systemic administration of anti-inflammatory drugs to sepsis should be reconsidered.

Effect of a maldistribution of microvascular blood flow on capillary O(2) extraction in sepsis

Inherent in the remote organ injury caused by sepsis is a profound maldistribution of microvascular blood flow. Using a 24-h rat cecal ligation and perforation model of sepsis, we studied O(2) transport in individual capillaries of the extensor digitorum longus (EDL) skeletal muscle. We hypothesized that erythrocyte O(2) saturation (SO(2)) levels within normally flowing capillaries would provide evidence of either a mitochondrial failure (increased SO(2)) or an O(2) transport derangement (decreased SO(2)). Using a spectrophotometric functional imaging system, we found that sepsis caused 1) an increase in stopped flow capillaries (from 10 to 38%, P < 0.05), 2) an increase in the proportion of fast-flow to normal-flow capillaries (P < 0.05), and 3) a decrease in capillary venular-end SO(2) levels from 58.4 +/- 20.0 to 38.5 +/- 21.2%, whereas capillary arteriolar-end SO(2) levels remained unchanged compared with the sham group. Capillary O(2) extraction increased threefold (P < 0.05) and was directly related to the degree of stopped flow in the EDL. Thus impaired O(2) transport in early stage sepsis is likely the result of a microcirculatory dysfunction.

Contractile activity of gastroduodenal and ileocecal zones during stress in rabbits

Chronic experiments on rabbits showed that stress modeled by immobilization in the supine position induced different motor reactions in the gastroduodenal and ileocecal zones. Stress inhibited contractile activity in the stomach antrum, distal ileum, ileocecal valve area, and proximal colon and stimulated it in the duodenum. In the pyloric portion of the stomach both the inhibitory and potentiating effects of stress were observed.

Surgical stress shifts the intestinal Escherichia coli population to that of a more adherent phenotype: role in barrier regulation

BACKGROUND

We have shown that the combination of surgical stress and starvation in mice is associated with a defect in epithelial permeability and increased numbers of mucosa-associated Escherichia coli in the cecum. The aim of this study was to determine the specific role of mucosa-associated E coli on epithelial barrier dysfunction in this model.

METHODS

Cecal E coli were harvested from mice 48 hours after a sham operation (control mice) or after a 30% surgical hepatectomy with only water provided ad libitum (short-term starvation) after the surgical procedure. Strains were tested for their ability to adhere to and alter the transepithelial electrical resistance (TEER) of cultured young adult mouse colon epithelial cells. TEER changes were further characterized by mannitol fluxes to confirm a defect in paracellular permeability.

RESULTS

Strains of cecal E coli harvested from hepatectomy-starved mice adhered to and altered the permeability of young adult mouse colon cells, whereas E coli from the cecum of control mice were less adherent and had no effect on epithelial permeability. The effect of the strains harvested from mice after hepatectomy on the TEER of young adult mouse colon cells was inhibited by mannose and reversed by ciprofloxacin.

CONCLUSION

The combination of surgical stress and short-term starvation is associated with a greater abundance of adherent and barrier-altering strains of E coli in the mouse cecum.

Effects of germinated barley foodstuff on microflora and short chain fatty acid production in dextran sulfate sodium-induced colitis in rats

Germinated barley foodstuff (GBF) administration has been previously reported to suppress dextran sulfate sodium (DSS)-induced experimental colitis. In this study, we investigated the roles of the intestinal microflora and short chain fatty acids (SCFAs) following administration of GBF in DSS-induced rat colitis. Sprague-Dawley rats were fed 3% (w/w of diet) DSS in GBF-diets for 5 days. The control rats were fed 3% DSS in cellulose-diets for 5 days. The administration of GBF effectively prevented bloody diarrhea and mucosal damage as compared to control rats. GBF significantly elevated fecal acetic acid and n-butyric acid levels. GBF tended to increase the number of eubacteria and that of bifidobacteria as compared to control rats. In addition, the number of enterobacteriaceae, the total number of aerobes and bacteroidaseae, were significantly lower in rats fed GBF than in the control group. It is suggested that the therapeutic effects of GBF for DSS-induced colitis depend mainly on increased SCFAs, which are accompanied by changes of composition of intestinal bacteria.

In vitro evaluation of intraluminal factors that may alter intestinal permeability in ponies with carbohydrate-induced laminitis

OBJECTIVES

To study the in vitro effects of cecal contents incubated with corn starch on colonic permeability in horses.

ANIMALS

4 healthy adult ponies.

PROCEDURE

Mucosal specimens were obtained from the right ventral colon and mounted in Ussing chambers. Changes in short circuit current, conductance, and large-molecule permeability in response to addition of cecal contents and cecal contents incubated with corn starch were evaluated for 120 minutes.

RESULTS

Incubation of cecal contents with corn starch for 8 hours resulted in a decrease in cecal content pH and an increase in lactic acid concentration. These changes were similar to those reported in vivo for ponies given corn starch. Exposure of colonic mucosa to cecal contents incubated with corn starch resulted in an increase in tissue conductance and permeability of technetium Tc 99m pentetate, compared with mucosa exposed to cecal contents alone.

CONCLUSIONS AND CLINICAL RELEVANCE

In vitro exposure of colonic mucosa to cecal contents incubated with starch resulted in increased paracellular permeability. Fermentation of excessive amounts of carbohydrate in the intestinal lumen of horses may directly induce increased intestinal permeability associated with carbohydrate-induced laminitis.

Xenogeneic patch closure of the small intestine: a novel approach to fistula management

Previous work from our laboratory demonstrated the feasibility of utilizing placental-derived collagen tissue matrix (CTM) as a bowel wall substitute. We reasoned that this technique would also be suitable in managing intestinal fistulae. To test this hypothesis, we created a chronic cecal fistula in rats and randomly managed some with primary repair and others with CTM replacement. Leak rates, mortality, bursting pressures and histologic scores were similar, suggesting that a chronic fistula can be successfully managed with either a CTM or primary repair.

Effect of sodium butyric acid, sodium valerianic acid, and osmolarity on contractility of specimens of intestinal wall obtained from the cecum and spiral colon of healthy cows

OBJECTIVE

To compare the effect of various concentrations of sodium butyric acid and sodium valerianic acid, as well as various osmolarities, on contractility of ex-vivo intestinal wall specimens obtained from the cecum and spiral colon of each of several healthy cows.

SAMPLE POPULATION

Full-thickness preparations of intestinal wall, dissected parallel to the longitudinal smooth muscle layers, harvested from freshly slaughtered healthy cows.

PROCEDURE

Specimens of intestinal wall were incubated for 5 minutes with various concentrations of sodium butyric acid and sodium valerianic acid as well as various osmolar concentrations of NaCl, using a crossover design. Isometric contractions were induced 7 times with carbachol (CH; 5 X 10(-6) mol/L). Contractility was defined as the maximum amplitude of contraction and the amplitude of contraction 2 minutes after addition of CH.

RESULTS

Repeated addition of CH did not result in a significant effect on contractility of specimens from the cecum and spiral colon. Contractility after addition of CH was not significantly affected by prior incubation with various concentrations of sodium butyric acid or sodium valerianic acid or after an increase of osmolarity. Maximum amplitude of contraction was significantly higher in specimens from the spiral colon, compared with specimens from the cecum.

CONCLUSIONS

Increases in concentrations of sodium butyric acid or sodium valerianic acid and increases in osmolarity did not inhibit contractility of intestinal wall specimens from the cecum and spiral colon of a group of healthy cows.

Ion transport across the cecum in normal and colitic mice

This study was conducted to determine the ion transport mechanisms in the normal mouse cecum and compare them to an inbred mouse model of colitis. The Ussing chamber-voltage clamp technique was used to monitor the short circuit current (I(sc)). The basal I(sc) in the normal cecum was 82.6 +/- 5.8 microA/cm2. It was not affected by bumetanide, 9-anthracene carboxylate, amiloride, and phenamil or by removal of Cl- ions; but was abolished by the removal of Na+ ions. Flux measurements revealed the presence of neutral NaCl transport. In the colitic cecum, the basal current was significantly higher than the normal cecum. Basal current in the normal cecum was due primarily to Na+ absorption through a Na+ channel, while in the colitic cecum it was due to Cl- ion secretion. cAMP addition in colitic cecum did not increase Cl- secretion, further suggesting that the tissue is already secreting at a maximal rate.

[Cecum reservoir]

The choice of the best reconstruction technique following resection of either the stomach or the rectum remains a matter of discussion. While there is no problem in reconnecting intestinal segments, which do not serve as a reservoir, there are many different operation techniques to replace the stomach and rectum, producing significantly different functional results. The ileocecal segment offers an excellent intestinal reservoir combined with an antireflux mechanism, thus presenting an ideal replacement for the stomach. For replacement of the rectal reservoir as well, the ileocecal segment may be used in the first line of treatment.

METHOD

The ileocecal segment was used in 20 patients following gastric resection and lymphadenectomy to reconstruct the intestinal passage between the esophagus and the duodenal stump (group A). In some further 44 patients (group B) the ileocecal segment was used to replace the rectum between the descending colon and the dentate line following resection for very low-grade rectal cancer. Mortality and morbidity were investigated in both groups. In group A quality of life, weight loss, dumping and reflux symptoms were evaluated. In group B continence, discrimination, defecation quality, urge and the patient satisfaction were investigated. All data were recorded prospectively.

RESULTS

Early and late mortality were not different compared to other reconstruction types. In each group one patient died within 60 days postoperatively due to myocardial infarction. The morbidity following stomach replacement was 20%, following rectal replacement 4.6% during hospitalization and 13.8% during follow-up, respectively. One patient complained about heartburn, but endoscopically no pathology was detected in any patient. Three months postoperatively the patients' weight remained stable or started to increase. Three months following rectal replacement 87% of the patients were continent with further improvement over 2 years. Soiling mainly during the night remained over 2 years in 44%. 88% of the patients were completely satisfied 2 years postoperatively.

CONCLUSION

The replacement of either the stomach or the rectum using the ileocecal segment with an adequate surgical technique is safe and produces excellent functional outcome regarding the reconstruction of the intestinal passage as well as the reservoir function of the primary organ. Furthermore, preservation of the duodenal passage after gastrectomy may prevent dysregulation of the endocrine and exocrine pancreatic hormones.

Increased levels of surgical adhesions in TGFbeta1 heterozygous mice

Adhesion formation and fibrosis represent a major complication of surgical intervention. Reducing the morbidity associated with adhesions requires an understanding of the mechanisms underlying their formation. Since increased levels of transforming growth factor-beta1 (TGFbeta1) have been associated with inflammation and adhesion production, we investigated the requirement of TGFbeta1 in peritoneal adhesion formation utilizing mice carrying a targeted disruption of the TGFbeta1 allele. Mice that were either wild-type (+/+), containing two normal alleles of TGFbeta1, or heterozygous (+/-) for the TGFbeta1 null allele received injections of magnesium silicate (talc), and the extent of abdominal adhesions was determined utilizing a standard grading score. Wild-type (+/+) animals had at least twofold more TGFbeta1 protein in peritoneal fluids at 2 h posttrauma compared to heterozygous (+/-) mice (727 vs. 243 pg TGFbeta1/mg protein by enzyme-linked immunosorbent assay (ELISA) in +/+ and +/- mice, respectively), and had significantly less scar and adhesion formation (p < .05) at 7 days posttrauma (1.8 +/- 0.8 vs. 3.4 +/- 1.4, graded from 0 to 5, in +/+ and +/- mice, respectively). These results demonstrate that haploid insufficiency in TGFbeta1 levels can lead to inappropriate matrix and adhesion production during inflammation, and together with previous studies suggest that any perturbation of normal TGFbeta1 levels can modulate the injury response that regulates the extent of adhesion formation.

Familial megacecum and colon in the rat: a new model of gastrointestinal neuromuscular dysfunction

Gastrointestinal motility disorders are of considerable clinical importance in humans and animals. Abnormalities of smooth muscle and the enteric nervous system have been described. We have identified and characterized a new mutant stock of rats that develops severe megacecum and colon with pseudo-obstruction, Familial Megacecum and Colon (FMC). The inheritance pattern of FMC was characterized by selective breeding. Gastrointestinal motility was evaluated radiographically. Complete pathologic evaluations, including ultrastructural examination and staining of colonic segments for acetylcholinesterase, peripherin, vasoactive intestinal peptide, substance P, nitric oxide synthase, and somatostatin, were performed. Spontaneous contractility and contractile force in isolated colonic muscle strips were examined. Familial megacecum and colon is inherited as an autosomal recessive trait. The markedly dilated cecum and proximal portion of the colon are followed by a short, funnel-shaped segment and distal portion of the colon with normal or slightly reduced lumen. Although clinical features and gross anatomic changes of the colon resemble those of Hirschsprung's disease in humans and animals, aganglionosis is not a feature of FMC. An increase in somatostatin staining was observed in dilated regions of bowel. The spontaneous contractile frequency and contractile force were diminished in the affected colon. Familial megacecum and colon is a new mutant, distinct from previously described hereditary and targeted mutant rodent models that develop megacecum and colon as a result of distal colonic dysfunction. The functional or morphologic defect(s) that result in colonic dysfunction in rats with FMC was not determined. The disease may result from an absence or overexpression of a single or group of neurotransmitters or their respective neurons, receptor abnormalities, or defects in the intestinal pacemaker system.

Accelerated right colonic emptying after simulated upper gut hemorrhage

OBJECTIVE

Upper gastrointestinal hemorrhage delays gastric emptying. Our aim was to evaluate the effect of gastrointestinal hemorrhage on small intestinal, ileocecal, and proximal colonic transit.

METHODS

Healthy volunteers were randomized to receive either a duodenal infusion of heparinized autologous blood (n = 7) or egg white, acting as a control substance with similar composition; 1.5 mCi99mTc-DTPA was added to the infused substances. We infused 30 ml at an infusion rate of 1 ml/min. Gamma-camera images were taken for 4 h or until all radioactivity had entered the colon. Arrival of radiolabels in the colon and also counts in the ascending and transverse colon were quantified.

RESULTS

Small intestinal and ileocecal transit were not significantly different between blood and egg white infusions. However, ascending colonic emptying was significantly faster after blood infusion compared to egg white. Four hours after the start of blood infusion a median of 30% of counts were in the transverse colon (11-50%; 25th-75th percentile) versus 0% (0-7%) after egg white infusion (p < 0.001).

CONCLUSION

We concluded that simulated upper gastrointestinal bleeding hastens proximal colonic transit, but does not alter small intestinal transit and colonic filling.

Ileocecal valve resistance augmentation using glutaraldehyde cross-linked collagen: a canine model for endoscopic salvage of the leaking Indiana reservoir

PURPOSE

Periurethral injection of glutaraldehyde cross-linked collagen is a well-established modality for the treatment of patients with incontinence caused by structural defects at the bladder outlet. Little is known about the potential usefulness of this approach to the nonfunctioning continence mechanism of a leaking continent urinary reservoir. An animal model of an incontinent Indiana reservoir was created using the naturally incompetent canine ileocecal valve. The effectiveness and feasibility of endoscopic submucosal injection of glutaraldehyde cross-linked collagen into the ileocecal valve to increase resistance were examined.

MATERIALS AND METHODS

Seven beagle dogs underwent isolation of the ileocecal segment. The right colon and ileum were brought to the skin as 2 stomas. Baseline leak point pressures of the ileocecal valve were determined while infusing contrast material into the right colon. The leak point was observed fluoroscopically, and the pressure at which contrast material crossed the valve was measured. Glutaraldehyde cross-linked collagen, 4 to 10 ml., was injected endoscopically into the valve in a circumferential pattern. Leak point pressures were measured immediately, 1 month after injection and 3 months after injection.

RESULTS

An average of 7.1 gm. (range, 4.1 to 10.1 gm.) was required to create an endoscopically "closed" ileocecal valve. Leak point pressure increased from a mean 3.8 mm. water (range, 2.5 to 6.0 mm. water) at baseline to mean 35.7 mm. water after injection (range, 22.0 to 57.0 mm. water). At 1 month, mean leak point pressure decreased slightly to 26.7 mm. water. This pressure stabilized at 3 months at 29.5 mm. water.

CONCLUSIONS

Endoscopic delivery of glutaraldehyde cross-linked collagen into the ileocecal valve consistently enhanced resistance as measured by leak point pressure. This effect was durable over a 3-month period of observation. Admittedly, this period of observation is relatively short. Longer followup may have demonstrated significant diminution of collagen migration or resorption. However, this feasibility study demonstrates that collagen injections may provide a minimally invasive means of treating the incontinent continent urinary reservoir.

Gluten-free diet normalizes mouth-to-cecum transit of a caloric meal in adult patients with celiac disease

The mechanisms responsible for bowel disturbances in celiac disease are still relatively unknown. Recent reports suggested that small bowel motor abnormalities may be involved in this pathological condition; however, there are no studies addressing small bowel transit in celiac disease before and after a gluten-free diet. We studied the mouth-to-cecum transit time of a caloric liquid meal in a homogeneous group of celiac patients presenting with clinical and biochemical evidence of malabsorption and complaining of diarrhea. Sixteen patients were recruited and investigated by means of hydrogen breath test through ingestion of 20 g lactulose together with an enteral gluten-free diet formula. A urinary D-xylose test was also done in each patient. Both breath tests and D-xylose tests were carried out basally and after a period of gluten-free diet. Twenty healthy volunteers were recruited as a control group and underwent the same breath testing. At the time of the diagnosis, mouth-to-cecum transit time was significantly prolonged in celiacs with respect to controls (243 +/- 10 vs 117 +/- 6 min, P = 0.0001). The D-xylose test was also abnormal (average urinary concentration 2.8 +/- 0.25 g, normal values >4.5). No correlation was found in patients between mouth-to-cecum transit time and urinary D-xylose output (r = 0.22). After the gluten-free diet period, mouth-to-cecum transit time in celiacs was significantly reduced compared to prediet transit (134 +/- 8 vs 243 +/- 10 min, P = 0.0001) and did not show statistical difference when compared to that found in controls (P = 0.1). The D-xylose test reverted to normal in all but two subjects, who were found to be noncompliant with the diet. Mouth-to-cecum transit time is significantly prolonged in patients affected by untreated celiac disease when compared to healthy controls. This alteration might not be correlated to intestinal malabsorption, and the prolonged orocecal transit could be due to impaired small bowel function (deranged motility?). Since intestinal transit returned to normal values after an adequate gluten-free period, a link with severe active mucosal lesions is suggestive.

The influence of complex carbohydrates on Salmonella typhimurium colonization, pH, and density of broiler ceca

Salmonella typhimurium colonization, pH, and density of ceca were measured in 3-, 5-, and 6-wk-old broilers fed either a control ration or rations with added fructooligosaccharides (FOS) or lactose derivatives (LD). The purpose was to compare dietary crude FOS from Jerusalem artichokes with refined FOS and two LD for ability to reduce Salmonella colonization as determined by semi-quantitative procedures. Chicks were challenged commencing at 5 d, by exposure to chicks orally infected with S. typhimurium. With the exception of chicks fed crude FOS, the high prevalence of Salmonella infection at 3 wk declined as chicks aged. At 6 wk, broilers fed crude FOS had higher Salmonella counts than all other broiler groups, whereas broilers fed refined FOS had lower infections than control broilers. The decline of Salmonella infection of broilers fed either refined FOS or LD ceased after dietary additives were discontinued at 5 wk of age. At 6 wk, infection rates of the latter groups were at least as high as those of control broilers. Both FOS and LD reduced cecal pH and density. Broilers fed the control ration had higher pH at 5 and 6 wk and higher cecal densities at 3 and 5 wk than those of broilers fed rations containing 5% (wt/wt) carbohydrates. Treatment differences for cecal pH and density disappeared within 1 wk of withdrawal of carbohydrates from 5-wk-old broilers. No consistent effect of cecal pH and density on Salmonella infection was observed. Density was dependent on cecal volume, and at 6 wk of age, on broiler size.

Alterations in mucosal immune cell distribution in septic rats

A reduced cell-mediated immunity in the intestinal mucosa might promote gut barrier failure and bacterial translocation in shock. This study was performed to investigate changes from the normal distribution of cellular components of the immune system within the intestine during sepsis. Intra-abdominal sepsis was induced by cecal ligation and puncture. After 24 h, the animals were killed and specimens were taken from the small bowel. Immunohistochemical stainings were performed on frozen sections using monoclonal antibodies reactive with MHC class II positive cells (OX6), the alpha/beta antigen receptor on T lymphocytes (R73), CD4+ T lymphocytes (W3/25), CD8+ T lymphocytes (OX8), and macrophages (ED1). There was a significant reduction in the number of pan T lymphocytes as well as both CD4+ and CD8+ subsets in the mucosa of the septic rats as compared with sham operated rats (p < .01). In contrast, the populations of MHC class II positive cells and macrophages increased in sepsis (p < .01). We conclude that 24 h after the induction of peritonitis, there is an altered pattern of immunocompetent cells within the intestinal mucosa.

In vivo and in vitro experimental intestinal amebiasis in Mongolian gerbils (Meriones unguiculatus)

One of the main drawbacks of experimental amebiasis is the lack of an adequate animal model for invasive intestinal lesions. Mongolian gerbils are useful because both intestinal and hepatic amebiasis can be produced experimentally with Entamoeba histolytica trophozoites. In this paper we show results obtained with in vivo and in vitro models of intestinal amebiasis in gerbils. We inoculated gerbils intracecally with monoxenic cultures of a highly virulent E. histolytica HM1:IMSS substrain. In the in vivo model an increase in mucus production was observed during the first 6 h of interaction. Microulcerative mucosal lesions appeared at 24-72 h postinoculation. Inflammatory infiltrate and edema of the lamina propria were associated with superficial foci of necrosis. At 96 h the cecal mucosa had an almost normal appearance and live amebas were no longer detected. In the in vitro model, early damage was detected in cecal strips mounted in Ussing chambers as a rapid fall in potential difference, short-circuit current, and transepithelial resistance that correlated with the extent of the microscopic lesions produced. The latter consisted of cellular edema and the appearance of small, translucent vacuoles at the base of epithelial cells. Further damage led to loss of intercellular junctions, destruction of interglandular epithelial cells, and edema of the lamina propria. The present results demonstrate that the gerbil is useful as an experimental model for the analysis of early stages of invasive intestinal amebiasis both in vivo and in vitro.

Bacterial translocation and gut microflora in obstructive jaundice

Bacterial translocation from the gut is implicated in the pathophysiology of complications associated with obstructive jaundice. Absence of intraluminal bile salts and their antiendotoxic effects may result in overgrowth of bacteria, promoting bacterial translocation. The large bowel is the largest source of gram negative bacteria but the small bowel is more permeable. This study investigated the effect of obstructive jaundice on bacterial translocation and on the indigenous luminal microflora at 3 sites in the gastrointestinal tract. Significant bacterial translocation was demonstrated following 7 d of bile duct ligation compared with control or sham operated groups. A qualitative disturbance of the caecal indigenous microflora was demonstrated in jaundiced rats. There was no 'site-to-site' variation in the indigenous microflora at the 3 intestinal sites studied. We conclude that experimental obstructive jaundice for 1 wk promotes bacterial translocation without significant quantitative disturbance of the intestinal microflora in the small intestinal or caecum.

Reduction of risk following endotoxin injection in unilaterally nephrectomized rats

In this study the consequences of unilateral nephrectomy on the survival rate of rats were examined under severe pathological conditions including injection of a lethal dose of endotoxin (exogenic LPS), cecal puncture (endogenic LPS), injection of LPS concomitantly with renal ischemia as well as a simultaneous injection of LPS and glycerol to the leg muscle in order to induce acute renal failure. Sham operated rats did not exhibit higher survival rates than the nephrectomized rats. In most cases there was even a decrease in the percent age rate of deaths in the nephrectomized rats. Improvement in the resistance of the nephrectomized rats to pathophysiological stress occurred when stress was induced immediately following nephrectomy as well as when stress was induced 30 days following nephrectomy. No significant differences were found in blood pressure, heart rate, hematocrit, rate of respiration and body temperature in the nephrectomized rats as compared to rats that did not undergo nephrectomy. A possible explanation for our results is that the solitary kidney excretes more LPS into the urine.

Effects of vitamin E deficiency on autonomic neuroeffector mechanisms in the rat caecum, vas deferens and urinary bladder

1. Modified sucrose-gap, standard organ-bath techniques and transmitter release studies were used to examine neuromuscular transmission in the caecum, vas deferens and urinary bladder in normal rats and in rats maintained for 12 months on a diet free of vitamin E. 2. In the caecum circular muscle, non-adrenergic, non-cholinergic inhibitory junction potentials were absent from 48 and 15% of preparations from vitamin E-deficient and control animals, respectively. Cholinergic excitatory junction potentials were absent from 83 and 8% of vitamin E-deficient and control preparations, respectively. Responses to applied noradrenaline (0.1-30 microM), alpha,beta-methylene ATP (3-100 microM) and acetylcholine (0.1-30 microM) were attenuated or absent in vitamin E-deficient tissues. Responses to applied KCl were similar in both groups. Release of [3H]noradrenaline or endogenous acetylcholine could not be evoked from vitamin E-deficient tissues. 3. In contrast, in isolated preparations of the vas deferens and urinary bladder, neuromuscular transmission by adrenergic, cholinergic and purinergic components were unaffected by long-term vitamin E deficiency. 4. In conclusion, vitamin E deficiency causes dysfunction of autonomic neuroeffector mechanisms in the smooth muscle of the rat caecum, at both a pre- and postjunctional level. The lesions in autonomic transmission mechanisms brought about by long-term vitamin E deficiency were found only in the caecum; no changes in sympathetic neuromuscular transmission were observed in the vas deferens, or in parasympathetic neuromuscular transmission in the urinary bladder.

Scintigraphic measurement of ileocaecal transit in irritable bowel syndrome and chronic idiopathic constipation

This study investigated the hypothesis that some features of functional gastrointestinal disorders may be associated with abnormalities of ileocaecal transit by measuring ileocaecal transit using a scintigraphic technique in 43 patients with chronic constipation, 20 patients with irritable bowel syndrome (IBS), and 18 control subjects. Subjects ingested enteric coated capsules, which delivered 111-indium radionuclide to the distal ileum. Gammacamera images were acquired at hourly intervals until caecal filling was complete. Ileocaecal transit was defined as the time between peak scintigraphic activity in the terminal ileum and peak activity in the caecum. The mean (SD) ileocaecal transit of 103 (50) minutes in patients with IBS was significantly faster than that in control subjects (mean (SD) ileocaecal transit 174 (78) minutes, p < 0.002). There were no significant differences in ileocaecal transit between patients with chronic idiopathic constipation and the control subjects, or between patients with constipation predominant and diarrhoea predominant IBS. This study developed a practical scintigraphic method of measuring ileocaecal transit. The rapid ileocaecal transit in both the constipation and diarrhoea predominant forms of IBS suggests that bloating may not after all result from delayed ileal emptying.

Modulation of hemodynamics and organ blood flow by nitric oxide synthase inhibition is not altered in normotensive, septic rats

Hyperdynamic sepsis is associated with a redistribution of organ blood flow. We hypothesized that increased nitric oxide (NO) production could mediate this process. The objective of this study was to determine the effect of a NO synthesis inhibitor on systemic and organ blood flows in vivo in septic and in normal rats. Rats were instrumented for hemodynamic monitoring and randomized to undergo cecal ligation and perforation (CLP) or control laparotomy. Cardiac output and organ blood flow were measured by thermodilution and radioactive microspheres, respectively. Baseline values were obtained at 24 h after CLP or control laparotomy and after the administration of L-nitro-arginine methyl ester (L-NAME) at 2, 4, 8, and 16 mg/kg intravenously. All studies were performed in awake, unrestrained animals. Septic animals were normotensive and hyperdynamic. L-NAME decreased cardiac index and increased systemic vascular resistance and mean arterial blood pressure to an equivalent degree in control and in CLP animals. CLP was associated with significantly increased relative blood flow to the small bowel and portal circulation. Although cardiac output decreased with L-NAME, blood flow to the diaphragm, liver, and brain was relatively well preserved. Absolute blood flow to other organs, including small bowel, decreased in parallel to the cardiac output. The effect of L-NAME on organ blood flow was comparable in control and in CLP animals. We conclude that the influence of NO on organ blood flows appears to vary between organs, but that NO does not explain the redistribution of blood flow observed in hyperdynamic sepsis.

Experimental colitis alters visceromotor response to colorectal distension in awake rats

The influence of intermittent colorectal distension (CRD) on proximal colonic motility and abdominal pain perception was investigated in awake rats equipped with intraparietal electrodes on the cecum, proximal colon, and abdomen, before and three days after rectocolitis induction by trinitrobenzene sulfonic acid (TNB)/ethanol. The normal myoelectrical activities of cecum and proximal colon [5.2 +/- 0.5 and 9.7 +/- 0.7 long spike bursts (LSB) per 5 min, respectively] were significantly (P < 0.05) and gradually decreased by control CRD, at diameters above 9 mm. At the maximum CRD diameter (13.7 mm), 1.6 +/- 0.6 cecal and 3.9 +/- 0.8 colonic spike bursts occurred per 5 min (respectively, 69 and 60% decreases). This upstream inhibition was accompanied by a significant (P < 0.05) and gradual increase in abdominal contractions (0.4 +/- 0.4 per 5 min in control vs 23.4 +/- 1.9 in response to 13.7 mm in diameter). Three days after TNB/ethanol, visceromotor and abdominal responses were significantly (P < 0.05) enhanced at the least CRD diameter of 9 mm (cecum: 3.1 +/- 0.4 after TNB vs 5.0 +/- 0.7 in control; proximal colon: 5.1 +/- 0.9 vs 9.3 +/- 2.2; abdomen: 7.7 +/- 1.5 vs 0.5 +/- 0.4). We conclude that in awake rats, CRD evokes both abdominal contractions in response to pain and inhibition of cecal and proximal colonic motility, which thresholds are both lowered by TNB-induced rectocolitis.

Colic motor complex of the cecum and proximal loop of the ascending colon observed in an experimental cow with large intestinal obstruction

Myoelectric activity of the cecum and proximal loop of the ascending colon (PLAC) and the effect of xylazine on motility of this intestinal segment in an experimental cow with large intestinal obstruction are described and compared with the normal motility pattern. During obstruction, three major observations were made in the prestenotic area. (i) Mean spike duration, overall duration of spiking activity (expressed as percentage of total recording time), number of spikes propagated from the cecum towards the obstruction site, and velocity of propagated spikes were substantially increased. (ii) The spike frequency was in the physiologic range. (iii) A single injection of xylazine, administered intravenously at a dose of 0.05 mg/kg markedly reduced the mean spike duration, the overall spiking activity, and the number of propagated spike sequences, and abolished signs of abdominal discomfort. Our data indicate that obstruction of the bovine colon causes a similar pattern of prestenotic hypermotility (colic motor complex) as described for the small intestine of the horse. Xylazine may be a suitable drug to disrupt prestenotic hypermotility and alleviate abdominal discomfort during proximal colonic obstruction in cattle.

[Temperature range in bipolar high frequency coagulation of the appendiceal stump]

Since laparoscopic appendectomy is performed more frequently disturbances of cecal motility have been found postoperatively in many cases. The etiology of this "syndrome of the fifth day" has not been cleared yet. To assess whether high-frequency bipolar electrocautery could be one of the etiologic factors, measurements of temperature were performed in lamb bowel, cadaver appendices and in vivo during laparoscopic appendicectomy. Next to the appendix stump ligation at the cecum wall the mean maximal temperature was as high as 53.2 degrees C. We believe that high frequency electrocoagulation is one of the etiologic factors of disturbances of the cecal motility especially if safety distances are not followed.

Hyperglycemia modulates gallbladder motility and small intestinal transit time in man

The aim of the present study was to investigate the effect of acute hyperglycemia on (1) the intestinal phase of gallbladder contraction induced by the intraduodenal administration of emulsified fat, and (2) the small intestinal transit time measured by the lactulose breath hydrogen test. Six healthy volunteers were studied in random order during normoglycemia and hyperglycemia (blood glucose levels 15 mmol/liter). Gallbladder volumes were measured with ultrasonography. Administration of 1 and 2 g/hr of fat resulted in significant reductions in gallbladder volumes from 24 +/- 2 cm3 to 11 +/- 1 cm3 (P < 0.05) and 8 +/- 1 cm3 (P < 0.05), respectively during normoglycemia, and from 24 +/- 2 cm3 to 21 +/- 2 cm3 (P < 0.05) and 16 +/- 2 cm3, respectively (P < 0.05) during hyperglycemia. Compared to normoglycemia, the gallbladder contraction was significantly (P < 0.05) reduced during hyperglycemia. No significant differences in CCK secretion were observed between experiments. Small intestinal transit time during hyperglycemia (101 +/- 12 min) was significantly (P < 0.05) prolonged compared to normoglycemia (57 +/- 12 min). During hyperglycemia, basal PP levels and PP secretion in response to intraduodenal fat were significantly (P < 0.05) reduced compared to normoglycemia. It is concluded that (1) low doses of intraduodenal emulsified fat result in significant gallbladder contraction and CCK secretion, (2) acute hyperglycemia inhibits intraduodenal fat induced gallbladder contraction, (3) acute hyperglycemia does not affect the intraduodenal fat induced CCK secretion, (4) small intestinal transit is significantly prolonged during acute hyperglycemia, and (5) acute hyperglycemia inhibits basal and stimulated plasma PP secretion, suggesting impaired vagal-cholinergic tone during hyperglycemia.

[The morphofunctional characteristics of the cecum in experimental influenza]

On the model of experimental influenza using morphological, immunomorphological, cytochemical, electron microscopy and morphometric methods, the authors provided morphofunctional characteristics of the caecum, showed the progression of infectious process and confirmed the dissemination of the virus, availability of virus particles in different cell populations, among them in lymphoid cells.