Muscular Thickness Research Articles

Does the removal of pectoralis minor impair the function of pectoralis major?

The treatment of long-standing unilateral facial palsy with cross-facial nerve graft and free pectoralis minor muscle flap to the face has been the elective choice for more than 300 patients during the last 20 years at Mount Vernon Hospital in Northwood, United Kingdom. In this study, the authors assessed the residual donor-site morbidity in the chest after the procedure. During the second stage of the operation, the medial and the lateral pectoral nerves are divided at a proximal level from the plexus. Due to the common innervation shared by the two pectoral muscles, a consequent change in pectoralis major muscle function can be expected, but so far no study has been carried out to find out whether or not this occurs. The authors have performed a subjective and an objective study on a voluntary sample of 38 patients previously operated on for facial palsy with pectoralis minor muscle transfer. Cosmetic and functional outcomes were recorded. The subjective evaluation was obtained through a questionnaire. The objective evaluation was obtained through physical examination (inspection and palpation). The following quantitative parameters were determined: thickness of the muscle, arm muscle circumference, power produced at contraction, and muscle fiber activity. Subjectively, six patients (15.8 percent) reported a reduction in the force of the muscle, and 10 patients (26.3 percent) noticed a change in muscular thickness at the site of the operation. Objectively, the results of the electromyogram were almost normal in all of the muscles sampled (17 patients). Occasionally, minor changes from the normal pattern were seen in the lower half of pectoralis major. The dynamometer adduction test showed a significant reduction in the force developed on the operated side when it was the dominant side (p = 0.02), whereas no difference was shown in the group of patients who underwent operations on the nondominant sides (p = 0.18). The pectoral fold and the arm muscle circumference did not show any difference between the side operated on and the nonoperated side. This clinical study confirms that the use of the pectoralis minor muscle as a neurovascular free flap for face reanimation is associated with a low morbidity at the donor site. The authors believe that the medial pectoral nerve has a marginal role in pectoralis major muscle innervation in contrast to the classic anatomic descriptions and some of the positions of the official surgical literature regarding the actual function of this nerve.

The development of jejunum and ileum during the fetal period

Objective: In our study, the morphologic structures of the jejunum and ileum sections of small intestine were investigated in human fetuses during the fetal period. Materials and methods: The study was realised on 131 human fetuses (male: 69; female: 62) with ages between 10 and 40 weeks, which have got no external pathology and anomalies. The external sizes of fetuses were measured, and then the structures in the abdominal cavity were determined by the abdominal dissection. The localization of jejunum and ileum, duodenojejunal flexure and ileal orifice points, the measurements of macroscopic diameters, types of the mass of jejunum and ileum and the localization according to the abdominal regions of the mass of jejunum and ileum were determined. Also, the samples of the jejunum and ileum were examined both macroscopically and microscopically. The thickness of tunica serosa, tunica muscularis and tunica mucosa was determined under the light microscope. Results: According to the sexes, gestastional ages and groups, the averages and the standard deviations of the all parameters were determined. The correlations between the parameters were determined. The percentage of parameters was compared according to sex and among groups. No differences were found in parameters between sexes ( p<0.05). The macroscopic parameters were increased according to the gestational age. The thickness of tunica serosa did not change according to the gestational age. Conclusion: It is thought that the data we have will help the evaluation of jejunum and ileum in intrauterine period; we also believe that the data in our study may help in the diagnosis and treatment of anomalies and pathologies in fetal period that belongs to jejunum and ileum.

Is constipation caused by a loss of colonic interstitial cells of Cajal?

Is constipation caused by a loss of colonic interstitial cells of Cajal?

Histologic analysis of chronic inflammatory patterns in the gallbladder: diagnostic criteria for reporting cholecystitis.

Cholecystectomy is one of the most common surgical procedures. Inflammatory disease is by far the most common pathology of the gallbladder. Terms for describing cholecystitis are numerous, thus there is no uniform terminology. One hundred cholecystectomies and 10 gallbladders from autopsies were reviewed and inflammatory changes were analyzed. Chronic cholecystitis was seen in 75% of cases with epithelial metaplasia and 73% with regenerative epithelium, the latter being associated with erosion but not with the presence of lithiasis. Muscular thickening and adipose deposits were mostly mild. Inflammation was mild in 28%, moderatein 57%, and severe in 15%. Activity was found in 29% of cases. Fibrosis was present in all cases: 26% mild, 62% moderate, and 12% severe. Autopsy cases did not show significant changes. A simple and reproducible scoring system of inflammation and fibrosis of the gallbladder is proposed. Three numbers refer to mild, moderate, or severe degrees of chronic inflammation and activity, with a final score that results from adding both values. The fibrosis is classified in three different stages. The final report uses both values to classify the chronic cholecystitis. A scoring system for chronic cholecystopathy to replace descriptive terms would give an exact transduction of the observed changes in an objective fashion that could not be misinterpreted by physicians or other pathologists.

Role of platelet-derived growth factor in vascular remodeling during pulmonary hypertension in the ovine fetus.

Platelet-derived growth factor (PDGF) is a potent smooth muscle cell mitogen that may contribute to smooth muscle hyperplasia during the development of chronic pulmonary hypertension (PH). We studied changes in PDGFalpha- and beta-receptor and ligand expression in lambs with chronic intrauterine PH induced by partial ligation of the ductus arteriosus (DA) at gestational age 124-128 days (term = 147 days). Western blot analysis performed on whole lung homogenates from PH animals after 8 days of DA ligation showed a twofold increase in PDGFalpha- and beta-receptor proteins compared with age-matched controls (P < 0.05). Lung PDGF-A and -B mRNA expression did not differ between PH and control animals. We treated PH animals with NX1975, an aptamer that selectively inhibits PDGF-B, by infusion into the left pulmonary artery for 7 days after DA ligation. NX1975 reduced the development of muscular thickening of small pulmonary arteries by 47% (P < 0.05) and right ventricular hypertrophy (RVH) by 66% (P < 0.02). Lung PDGFalpha- and beta-receptor expression is increased in perinatal PH, and NX1975 reduces the increase in wall thickness of small pulmonary arteries and RVH in this model. We speculate that PDGF signaling contributes to structural vascular remodeling in perinatal PH and that selective PDGF inhibition may provide a novel therapeutic strategy for the treatment of chronic PH.

Effects of erythropoietin and pentoxifylline on the oxidant and antioxidant systems in the experimental short bowel syndrome.

In this study, we investigated the effects of erythropoietin (Epo), and pentoxifylline (Ptx) on the oxidant and antioxidant systems in the experimental short bowel syndrome. Spraque-Dawley rats were divided into four groups and all animals underwent 75% small bowel resection. Group E was treated with 500 IU kg(- 1) Epo subcutaneously (s.c.), group P with 50 mg kg(- 1) day(- 1) s.c. Ptx and group E+P with 500 IU kg(- 1) s.c. Epo plus 50 mg kg(- 1) day(- 1) s.c. Ptx for a period of 28 days. In group C, which is the control group, no drug treatment was given. At the end of 28 days the experimented rats were killed and ileum samples excised for biochemical and histopathological testing. Malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels were determined in ileum homogenates. When compared to group C, the MDA and GSH-Px levels were significantly decreased (p < 0.05), but SOD activity was not changed (p > 0.05) in groups P and E+P, whereas both MDA and SOD and also GSH-Px activities were not changed significantly in group E (p > 0.05). The average villous length, crypt depth, muscular thickness and mucosal length were measured in all groups. The average crypt depth and mucosal length were statistically higher in the group P than group C (p < 0.001, p < 0.01, respectively). In addition, the crypt depth was statistically higher in both E and E+P groups as compared to group C (p < 0.001, p < 0.01, respectively). Therefore, our study indicates that Ptx may be more effective than Epo in reducing lipid peroxidation. Moreover, we considered that Ptx may give this protective effect by inhibiting the free oxygen radicals to a greater extent than developing the antioxidant capacity.

Esophageal ligature in experimental gastroschisis

Background/Purpose: Recently, the authors have shown that in human fetuses suffering from gastroschisis, there is an amniotic fluid inflammatory response and that amniotic fluid exchange designed to disrupt the inflammatory loop seems to have a favorable impact on outcome. The authors, therefore, designed in the fetal sheep a model of gastroschisis in which amnioinfusion significantly improved the deleterious process. They hypothesized that regurgitation and presence of digestive enzyme in the amniotic fluid triggers and maintins the process of inflammation. Methods: To test this hypothesis, the authors used their model of gastroschisis in the fetal lamb combined with esophageal ligation and compared it with gastroschisis with or without amnioinfusion. Results: Of 34 fetuses operated on at midgestation (days 70 through 80), 11 died in utero or were stillborn, 8 had gastroschisis and amnioinfusion, 8 had gastroschisis and no amnioinfusion, and 7 had gastroschisis and esophageal ligation. There were 9 control fetuses. Fetuses were killed at day 145 by cesarean section. Extraabdominal bowels with fibrous peel were processed for histologic examination. Thickness of bowel muscularis (micrometers) was 82.7 ± 19 for controls, 159 ± 56 for the nonamnioinfused fetuses, 126 ± 21 for the amnioinfused fetuses (P =.001), and 240 ± 225.8 for fetuses with esophageal ligature combined with gastroschisis. The same results were obtained for thickness of serous fibrosis and plasma cell infiltration. Assay of amniotic fluid ferritin, lipase, and protein showed that only amnioinfusion lowered ferritin and protein to levels similar to those of controls, thus, illustrating its preventive effect on inflammation and that esophageal ligature did not prevent digestive enzyme presence in the amniotic fluid. Conclusion: In this model of gastroschisis in the fetal sheep, ligature of the esophagus, which was supposed to protect the extruded bowel by preventing oral regurgitation of digestive enzymes and by creating a relative hydramnios, did not improve the inflammatory and deleterious process, which is best prevented by amnioinfusion. J Pediatr Surg 37:1160-1164. Copyright 2002, Elsevier Science (USA). All rights reserved.

Successful tolerance induction under CD40 ligation in a rodent small bowel transplant model: first report of a study with the novel antibody AH.F5.

Intestinal transplantation has been hampered by high rates of intestinal allograft rejection. One mechanism of altering rejection in other organ transplant models has been blockade of second set T-cell costimulatory signals. AH.F5, a novel hamster anti-rat monoclonal antibody to CD154, blocks CD40-dependent T-cell costimulation. We hypothesized that blockade of this pathway might abrogate rejection in a rodent orthotopic survival model of intestinal transplantation. Eight groups were studied with different dosing schema, including syngeneic transplants (group 1), untreated allogeneic transplants (group 2), allogeneic transplants plus multiple doses of AH.F5 alone given IV or s.c. (groups 3 and 4), allogeneic transplants plus donor splenocyte preconditioning with and without single dose AH.F5 (groups 5 and 6), and donor splenocyte preconditioning followed by multiple doses of AH.F5 with and without thymectomy (groups 7 and 8). Control animals all died within 12 days of transplantation, whereas antibody-alone and splenocytes-alone resulted in modest prolongation of survival to 16 days. Only animals treated with splenocytes before transplantation and AH.F5 survived long-term (>60 days, group 8). These animals tolerated donor-specific skin grafts, rejected third-party grafts, and fed normally. However, their weight gain was subnormal and they demonstrated intestinal muscular thickening, which might represent chronic rejection. Thymectomy prevented the induction of tolerance. AH.F5 prevents acute intestinal allograft rejection in combination with donor-specific splenocyte preconditioning. We achieved long-term survival and the animals appeared tolerant. Central conditioning is essential for success with this antibody when used alone. Further studies with different dosing regimens or second agents seem warranted.

Enterocele

In Brief OBJECTIVE To examine the histology of the vaginal wall in women with an enterocele confirmed by physical examination, cystoproctography, and intraoperative exploration. METHODS Thirteen women with posthysterectomy apical and posterior wall prolapse were evaluated with a detailed physical examination, cystoproctography, and intraoperative exploration. All women had enterocele repair. A specimen of full thickness vaginal wall from the leading edge of the enterocele was excised and examined histologically. The histology of these patients was compared with the histology of two comparison groups, five women undergoing hysterectomy without prolapse and 13 women undergoing radical hysterectomy. RESULTS One woman with an enterocele repaired intraoperatively did not have an enterocele by cystoproctography. One woman with an enterocele repaired intraoperatively did not have an enterocele detected by physical examination. All women with an enterocele repaired had an intact vaginal wall muscularis. No woman had vaginal wall epithelium in direct contact with the peritoneum. The average vaginal wall muscularis thickness in women with enteroceles was 3.5 ± 1.4 mm, in women with no prolapse 3.2 ± 0.8 mm, and in women undergoing radical hysterectomy 2.8 ± 0.9 mm. CONCLUSION Women with enteroceles have a well-defined vaginal muscularis between the peritoneum and vaginal epithelium. Women with enteroceles have a well-defined vaginal muscularis between peritoneum and vaginal epithelium.

Enterocele: is there a histologic defect?

OBJECTIVE: To examine the histology of the vaginal wall in women with an enterocele confirmed by physical examination, cystoproctography, and intraoperative exploration. METHODS: Thirteen women with posthysterectomy apical and posterior wall prolapse were evaluated with a detailed physical examination, cystoproctography, and intraoperative exploration. All women had enterocele repair. A specimen of full thickness vaginal wall from the leading edge of the enterocele was excised and examined histologically. The histology of these patients was compared with the histology of two comparison groups, five women undergoing hysterectomy without prolapse and 13 women undergoing radical hysterectomy. RESULTS: One woman with an enterocele repaired intraoperatively did not have an enterocele by cystoproctography. One woman with an enterocele repaired intraoperatively did not have an enterocele detected by physical examination. All women with an enterocele repaired had an intact vaginal wall muscularis. No woman had vaginal wall epithelium in direct contact with the peritoneum. The average vaginal wall muscularis thickness in women with enteroceles was 3.5 ± 1.4 mm, in women with no prolapse 3.2 ± 0.8 mm, and in women undergoing radical hysterectomy 2.8 ± 0.9 mm. CONCLUSION: Women with enteroceles have a well-defined vaginal muscularis between the peritoneum and vaginal epithelium.

Architecture and function of the gastroesophageal barrier in the piglet.

We describe the anatomy and function of the gastroesophageal barrier in the piglet. Male piglets underwent dissection (N = 6) and gastroesophageal muscle layer histometry (N = 6). Sedated, nonintubated animals (N = 13) underwent four-probe perfusion esophageal manometry and the pressure profiles were related to the muscular thickness in the four quadrants. Hiatal and gastroesophageal anatomy are similar to our own. The muscle is thicker at the point where the clasp (on the right side) and sling fibers (on the left) concentrate. The pressure profiles were axially and radially asymmetric in coincidence with the thickness variations of the corresponding muscle layers. Sphincteric pressure was recorded as a plateau, whereas diaphragmatic crural pressure appeared as phasic oscillations in synchrony with respiration. The sphincter relaxed upon deglutition. In conclusion, the gastroesophageal structure and physiology are so similar in men and piglets that piglets are excellent models for research in this area.

Ultrasonographic diagnosis criteria using scoring for hypertrophic pyloric stenosis

Purpose: For diagnosis of infantile hypertrophic pyloric stenosis (HPS), ultrasonography (US) is a useful and objective diagnostic method. In the current study, pyloric diameter, muscular thickness, and pyloric length were measured in normal infants (n = 26) and infants which is an adequate (n = 57). Each score was assigned to relevant measurements, and diagnostic criteria obtained with a scoring system were prepared using statistical skills by the probit analysis. Methods: For scoring, points were given to relevant measurements in conformity with the probit analysis. Zero points were given to patients with no possibility of HPS, 1 point to those with less than 25% probability, 2 points to those with 25% or more but less than 50% probability, and 3 points to patients with 50% or more probability. Points were totaled, and analysis was performed. Results: The composite score was evaluated by probit analysis, and cases with a composite score of 2 or less were all included in the normal group, whereas those with a composite score of 3 or more were all in the HPS group. Both groups could thereby be 100% identified. Conclusion: US was able to diagnose cases with overall score of 2 or less as normal and those with overall score of 3 or higher as having HPS. In addition, after the current diagnostic criteria were prepared, preoperative diagnoses were performed prospectively using them for vomiting neonates and infants, and all cases were correctly discriminated and diagnosed. These findings indicate our ultrasonographic diagnosis criteria are useful for diagnosing HPS. J Pediatr Surg 35:1714-1718. Copyright © 2000 by W.B. Saunders Company.

Influence of Amnioinfusion in aModel of in utero Created Gastroschisi s in the Pregnant Ewe

Objective: Recent studies on the management of human fetal gastroschisis have produced two major findings: (1) there is an inflammatory response in the amniotic fluid of these fetuses, and (2) amniotic fluid exchange designed to disrupt the inflammatory loop seems to have a favorable impact on the immediate and late outcome of these early operated neonates. To test this hypothesis, we used serial amniotic fluid exchanges in a model of gastroschisis developed in the ewe. Methods: Gastroschisis was created at midgestation in 21 lamb fetuses by an in utero technique. Saline was amnioinfused in some fetuses every 10 days to term. Fetuses were sacrificed on day 145 by cesarean section. Extra-abdominal bowels with fibrous peel were processed for histologic examination. Comparisons were done between fetuses without gastroschisis (controls), fetuses with gastroschisis and amnioinfusion, and fetuses with gastroschisis without amnioinfusion. Results: Of 21 fetuses operated, 8 died in utero or were stillborn; 5 were not amnioinfused, and 8 underwent amnioinfusion. Thickness of bowel muscularis (μm) was 92.6 ± 20.2 for controls, 126.2 ± 21 for the amnioinfused fetuses, and 182.8 ± 58.3 for the nonamnioinfused fetuses (p = 0.001). The same significant results were obtained for thickness of serous fibrosis (p = 0.02) and plasma cell infiltration (p = 0.015). Conclusions: We have created a model of gastroschisis suitable for experimentation in the fetal sheep. Our amnioinfusion data in this model indicate a clear improvement of the deleterious process. This finding correlates well with recent data on amnioinfusion as a therapeutic approach to human gastroschisis.

PULMONARY VASCULAR REMODELING DISTAL TO PULMONARY ARTERY LIGATION IS ACCOMPANIED BY UPREGULATION OF ENDOTHELIN RECEPTORS AND NITRIC OXIDE SYNTHASE

There is increasing evidence that the pathogenesis and progression of many forms of pulmonary vasculopathy are related to abnormalities in endothelial mediators, including endothelin-1 (ET-1) and nitric oxide (NO). Using a rat model of chronic unilateral pulmonary artery ligation, we investigated the role of ET-1 and NO in postobstructive pulmonary vasculopathy (POPV). Eight months after a left thoracotomy with either left main pulmonary artery ligation (ligated group) or no ligation (sham group), rat lungs, including those contralateral to the ligation (hyperperfused group), were fixed and mounted for histologic sectioning. Morphometric measurements were carried out by computer-assisted image analysis and immunohistochemical staining was performed using specific antibodies against ET-1, ETA, and EBB receptors, and endothelial NO synthase (eNOS). Compared to sham lungs, the ligated lungs showed (1) an increase in muscular, adventitial, and intimal thickness of pulmonary artery; (2) increase in external diameter of the bronchial artery (39.8+/-2.2 mum vs.16.8+/-0.9 mum in sham group; P <. 005) and number of bronchial arteries per bronchiole (3.21+/-mu0.26vs.1.86+/-mu0.21 in sham group; P <. 001); and (3) increase in the intensity of eNOS and ETA, B receptor immunoreactivity. No morphometric or immunohistochemical differences were observed between the hyperperfused and sham lungs. These ndings suggest that increased synthesis of endothelial NO may serve as a compensatory mediator in ET-1 mediated vascular remodeling.

Nitric oxide synthase inhibition prevents intestinal damage in gastroschisis: A morphological evaluation in chick embryos

Purpose : Increased small bowel nitric oxide (NO) synthase activity accused for postnatal intestinal dysmotility in gastroschisis. The purpose of this study is to evaluate the effect of prenatal NO synthase inhibition on intestinal damage in gastroschisis. Methods : Sixteen-day-old fertilized chick eggs were divided into 4 groups. In the control group, the allantoic and amniotic membranes were opened to create a common cavity. In the gastroschisis group, a defect in the abdominal wall was made, and intestinal loops were exteriorized. In the gastroschisis pretreated with l-NAME group, gastroschisis was created, and l-NAME was administered into the amnioallantoic cavity for 4 days. In the gastroschisis sham pretreated group, after the same surgical procedure as the previous group, same amount of saline was given beside l-NAME. At the end of 20th day of incubation, intestinal morphological changes were investigated macroscopically and microscopically. Results : Macroscopic changes such as shortening, thickening, and fibrous adhesions were found in the exteriorized bowels of the just gastroschisis group and the gastroschisis pretreated saline group. However, there was only mild thickening in the gastroschisis pretreated with l-NAME group. Microscopically, compared with the gastroschisis group, serosal thickness, muscular thickness, and bowel wall thickness were found to be significantly lower in the gastroschisis pretreated with l-NAME group (128.0 ± 19.3 μm and 239.5 ± 3.0 μm v 57.0 ± 8.2 μm and 145.0 ± 9.7 μm). Conclusion : It is possible to decrease intrauterine intestinal morphological changes in gastroschisis by inhibiting NO synthase.

Performance and gastro-intestinal response of broiler chickens fed on cereal grain-based foods soaked in water

1. Two experiments were carried out to investigate the addition of 1.3 kg water per kg air-dry mash diets containing high proportions (600 to 700 g/kg) of ground cereal grains (wheat, barley or oats) on broiler performance and the structure and function of the gastro-intestinal tract. 2. Chicks at the age of 7 d were fed on the wheat-, barley- or oats-based diets in the dry or wet forms for 35 d. Food and water intakes were recorded daily while body weight was measured weekly. Two birds from each treatment were killed each week to measure gut size and the viscosity of gut contents. Tissue samples from various digestive segments were histo-morphologically examined to determine the thickness of tissue layers, size of tissue glands, villa heights, crypt depths and thickness of tunica muscularis . Crypt cell proliferation rate (CCPR) for each segment was also determined using a metaphase arrest technique. 3. The results from both experiments showed that wetting food significantly ( P <0.05) increased food intake, total water intake and body weight gain of broiler chickens. The body weight gains of birds were proportional to their food intakes so that the efficiency of food utilisation was similar for all treatments. Dry matter retention of food tended to increase in birds given wet food from 7 to 21 d but not thereafter, compared to the dry-fed birds. Although water intake from the water bottle was significantly ( P <0.05) reduced in birds given wet food, total water intakes from the water bottle plus that from food were significantly ( P <0.05) higher in the wet-fed birds than in the dry-fed birds. The ratio of total water to dry food intake was, however, similar in both feeding regimens. 4. The fresh empty weight of the gut was increased by wet-feeding while its relative weight to body weight and the length of gut was not affected by dietary treatments. Significantly greater development of the tissue glands in the proventriculus and gizzard was observed in the birds given wet food; this was associated with the reduced thickness of the muscular layer of these segments. An increase in villus height was also observed in duodenum, small intestine, caeca and colon of birds given wet food, compared to those given dry food. CCPR was significantly ( P <0.05) reduced by wet-feeding throughout the digestive tract. This was associated with a significant decrease in the mean viscosity of the gut contents and the concentration of volatile fatty acids (VFAs) in the caeca. 5. Wetting diets based on cereal grains caused a significant improvement in the performance of broiler chickens. The mechanism of the beneficial effects of wet feeding could be attributed to the decreased viscosity of gut contents; the greater development of the layer of villi in the digestive segments and the reduced CCPR in the crypts of the epithelium.

Ultrasonographic quantification of muscular mass thickness in patients of intensive care unit

Ultrasonographic quantification of muscular mass thickness in patients of intensive care unit

Hymenolepis diminuta:Mucosal Mastocytosis and Intestinal Smooth Muscle Hypertrophy Occur in Tapeworm-Infected Rats

Dwinell, M. B., Wise, R. M., Bass, P., and Oaks, J. A. 1998.Hymenolepis diminuta:Mucosal mastocytosis and intestinal smooth muscle hypertrophy occur in tapeworm-infected rats.Experimental Parasitology89,92–102. The mechanisms mediating motility changes during noninvasive tapeworm infection have not been characterized. In contrast, host intestinal motility changes during invasive nematode infection are mediated by mucosal mast cells (MMC). The purpose of this study was to examine and the correlate onset of myoelectric alterations 8 days after initial tapeworm infection with changes in intestinal morphology, MMC numbers, and MMC secretory activity. Segments of the small intestine, the tapeworms normal habitat, along with stomach, colon, and bladder were taken from tapeworm-infected and control rats. Tissues were fixed and stained to identify MMC and for morphologic measurement. Tapeworm-infected and uninfected rats with chronically implanted intestinal electrodes were treated with ketotifen, a mast cell stabilizer, andin vivomyoelectric activity monitored. In tapeworm-infected rats, the muscularis externa, on day 20 postinfection, and crypts of Lieberkuhn, on day 26 postinfection, from the entire small intestine appeared thickened or deeper, respectively. Increased muscularis thickness was due to smooth muscle hypertrophy in both the circular and the longitudinal muscle layers. Mucosal mastocytosis was first observed on day 26 postinfection and occurred only in the ileum of tapeworm-infected rats. Pharmacologic stabilization of mast cells with ketotifen did not prevent onset of enteric myoelectric alterations during tapeworm infection. Stomach, colon, and bladder MMC numbers and tissue dimensions were not different betweenHymenolepis diminuta-infected rats and uninfected controls. Initiation of myoelectric alterations 8 days after infection precedes and may be a contributing factor to the onset of both smooth muscle hypertrophy and mucosal mastocytosis. Taken together, our data indicate that mast cells are not an initiating factor nor chronic stimulus maintaining intestinal myoelectric alterations duringH. diminutainfection.

Etiological analysis of focal nodular hyperplasia of the liver, with emphasis on similar abnormal vasculatures to nodular regenerative hyperplasia and idiopathic portal hypertension

Pathological studies were performed on 23 cases of focal nodular hyperplasia (FNH) under the hypothesis that FNH is a hyperplastic lesion caused by abnormal vasculatures of portal tracts within the nodule. For a comparison of the histological features of portal tracts, nodular regenerative hyperplasia (NRH), idiopathic portal hypertension (IPH), chronic hepatitis and so-called normal liver were used as control tissues. Extranodular areas of FNH nodules were also examined. Clinical data were briefly summarized. Most of the portal tracts within FNH nodules showed various abnormal findings, such as dilatation and/or stenosis of portal vein, muscular thickening of arterial wall with dilated or stenotic lumina, lymphocyte infiltration, and bile ductule proliferation. However, portal vein thrombi were not found. These findings were not thought to represent compensatory reaction to portal vein thrombosis. Similar abnormal features were also observed in extranodular areas of FNH although to a milder degree. These abnormal features resembled those of NRH and IPH. Moreover, the characteristic scar-like tissues within FNH nodules were proved to be abnormally large portal tracts including large feeding arteries, portal veins and bile ducts. It has been believed that septa and scar-like tissue within FNH nodules are not portal tracts and that arterial malformation independent of portal tracts are related to the development of FNH. In addition, venous structures within FNH modules have until now not been considered to be portal veins. However, this study revealed that severe anomaly of portal tracts including portal veins and hepatic arterial branches existed in FNH nodules. Moreover, portal tracts in extranodular areas were also abnormal. Clinically, only one patient had a history of oral contraceptives. Based on these findings, congenital anomaly of the portal tracts histologically resembling the abnormal portal tracts of NRH and IPH may be related to the pathogenesis of FNH.

Fermentation of dietary carbohydrates to short-chain fatty acids by gut microbes and its influence on intestinal morphology of a detritivorous teleost tilapia ( Oreochromis niloticus)

Fermentability of dietary cellulose, sodium alginate, chitin, α-starch and kaolin (non-fermentable control) by gut microbes was compared in a tilapia, Oreochromis niloticus, fed a diet containing one of the above supplements (150 g · kg −1) for 14 days. The thickness of the tunica muscularis was also compared among fish fed these diets. The concentration of short-chain fatty acids (SCFA) in gut contents was higher in fish fed the α-starch than in fish fed the sodium alginate, chitin, or kaolin diets. Intestinal contents from fish fed the kaolin (control) diet were incubated in batch culture with each of the other supplements. The volume of released gas and production of SCFA for 24 hr was greater with a α-starch as a substrate than in those with the other substrates. The thickness of the tunica muscularis differed among dietary groups but villus height did not. Fish fed chitin or α-starch had a thicker tunica muscularis than those fed cellulose or sodium alginate. These results suggest that this detritivorous fish digests α-starch to produce SCFA in the intestine by microbial fermentation.