[Anorectal manometry]. / Empfehlungen zur Anorektalen Manometrie im Erwachsenenalter.

This document contains the guidelines of the German Societies of Neurogastroenterology and Motility, Gastroenterology (committee for proctology), Abdominal Surgery (coloproctology working group), and Coloproctology for anorectal manometry in adults. Recommendations are given about technical notes, study preparation (equipment; patient), technique for performing manometry and data analysis, reproducibility, and indications. Minimum standards for anorectal manometry are measurement of resting and squeeze pressure, testing of rectoanal inhibitory reflex, determination of rectal sensation (first perception and urge), and calculation of rectal compliance. Anorectal manometry is indicated in patients with fecal incontinence and constipation in the context of a structured programme.

[The enteric nervous system and interstitial cells of Cajal. Changes in chronic constipation in adults]. / Enterisches Nervensystem und interstitielle Cajal-Zellen. Veränderungen bei chronischer Obstipation im Erwachsenenalter.

Intestinal innervation disorders are part of the broad etiological spectrum of chronic constipation and need to be specifically addressed in differential diagnosis. The enteric nervous system constitutes the largest peripheral nervous system of its own ("brain in the gut"), and is involved in the mediation of intestinal motility. Morphologically different nerve cell types aggregate into intramural plexus layers and release a multitude of neurotransmitters. Malformations or lesions of the enteric nervous system may lead to a severely prolonged intestinal transit time resulting in chronic constipation resistant to conservative treatment. In contrast to the early manifestation of aganglionosis, non-aganglionic or acquired alterations to the intramural nerve plexus often remain unrecognised up to adulthood. Histopathological diagnosis is carried out by enzyme or immunohistochemical staining, either on sections or whole mount preparations, allowing an optimal visualization of the nerve plexus architecture. To diagnose hypoganglionosis, enteric ganglionitis or alterations in interstitial cells of Cajal, full-thickness biopsies are required. Interstitial cells of Cajal contribute significantly to the mediation of intestinal motility by generating "slow wave" activity. In adult patients with slow-transit constipation and megacolon, the intramuscular networks of the interstitial cells of Cajal show a significantly reduced density.

[Probiotic drug therapy with E. coli strain Nissle 1917 (EcN): results of a prospective study of the records of 3,807 patients]. / Probiotische Arzneimitteltherapie mit E. coli Stamm Nissle 1917 (EcN): Ergebnisse einer prospektiven Datenerhebung mit 3,807 Patienten.

INTRODUCTION: Living microorganisms that enter the gut in an active state and exert a positive influence on the host are called probiotics. Numerous experimental and clinical studies were performed recently and confirm both the efficacy and modes of action of probiotic drugs. PATIENTS AND METHODS: In a post-marketing-surveillance study with the probiotic Escherichia Coli strain Nissle 1917 (EcN) data on the range of indications as well as on efficacy and tolerance were gathered prospectively in 446 centres. The intended treatment duration was limited to a maximum of 12 weeks. RESULTS: EcN was used in 3,807 patients with more than 20 different indications, n = 3,511 of whom had gastrointestinal complaints: Among others, 1,067 patients presented with chronically recurring (n = 728) or protracted diarrhoea (n = 339), 415 with inflammatory bowel disease, 679 with irritable bowel syndrome, and 253 with chronic constipation. The overall efficacy was assessed as good to very good by an average of 81.4 % of the therapists. The stool frequency and consistency as well as the symptoms of meteorism and abdominal pain were improved in very many patients. Suspected cases of side effects were documented in only 2.8 % of the patients. CONCLUSION: EcN is frequently used in practice for the treatment of various, mostly gastrointestinal, complaints and is well tolerated.

[Probiotics as therapeutic agents in irritable bowel syndrome]. / Probiotika in der Therapie des Reizdarmsyndroms.

Probiotics are defined as living micro-organisms which, when administered in large amounts, confer a health benefit on the host. The use of probiotics in the therapy of infectious bowel diseases as well as maintaining remission of ulcerative colitis and in pouchitis is evidence-based. Also, in several studies proof could be supplied that specific probiotics relieve the symptoms and the course of irritable bowel syndrome. Some trials showed a significant improvement of irritable bowel syndrome-related constipation via Lactobacillus casei Shirota and E. coli Nissle 1917. Lactobacillus plantarum has been proven effective in reducing pain and abdominal bloating. However, in most of the studies rather small numbers of patients were examined. Furthermore, these studies do not always closely follow scientific standards (randomised, double-blind, placebo-controlled). Therefore, confirmatory studies are necessary to examine the effect of probiotics in irritable bowel syndrome.

Molecular genetics of colorectal motility disorders.

In the last years, several genes have been identified which are involved in the development and differentiation of the enteric nervous system (ENS). Among the congenital intestinal innervation disorders described (aganglionosis, hypoganglionosis, heterotopic ganglia, intestinal neuronal dysplasia), up to now Hirschsprung's disease (HSCR) has been linked to mutational defects in these genes. GDNF and its co-receptor RET are the genes with the most mitogene potency on precursor cells of the ENS. The endothelin system (EDNRB/EDN3) also plays a key role in the development of the ENS by preventing its premature differentiation. Our own studies could show that, whereas a homozygous mutation of EDNRB causes long-segment HSCR, a heterozygous EDNRB deficiency leads to alterations of the ENS resembling the histopathology observed in intestinal neuronal dysplasia. Modern molecular genetic technologies combined with a subtle phenotypic assessment of the ENS will allow investigators to identify other genes within the complex signalling cascade required for the formation of the ENS. The recognition that intestinal innervation disorders are, at least in part, a multigenetic disease should provide support for consequent genetic screening in these patients.

Mitochondrial myopathy (complex I deficiency) associated with chronic intestinal pseudo-obstruction.

We report a patient presenting with severe muscular impairment and chronic intestinal pseudo-obstruction (CIP) at the age of eight months. Due to the aggravated symptoms, assisted ventilation, an ileostomy and total parenteral nutrition were required. Later on, the patient developed a locked-in syndrome (Leigh's subacute necrotising encephalomyelopathy) and finally died due to recurrent pneumonia and chronic renal failure. The assessment of muscle biopsies revealed a moderate single-fibre type II atrophy, a variation of muscle fibre calibre with focal fatty degeneration and a decreased reactivity of cytochrome-c oxidase. Although ragged red fibres had not been found, mitochondrial enzyme activities were markedly decreased with the lowest residual activity detected for NADH:Q1 oxidoreductase and NADH:O2 oxidoreductase (complex I deficiency), thereby confirming the diagnosis of mitochondrial myopathy. A molecular genetic analysis could not identify known mutations of mitochondrial DNA. Gastrointestinal full-thickness biopsies revealed myenteric hypoganglionosis of the colon and stomach and hyperplasia of the submucosal plexus of the ileum. Some of the intestinal smooth muscle cells displayed bulbous protrusions filled with lateralised mitochondria. Mitochondrial myopathies are known to be associated with a variety of clinical syndromes including CIP. However, in contrast to previous reports in which CIP has been attributed to visceral intestinal myopathies, the present case is characterised by neuronal intestinal malformations. Therefore, a mitochondrial myopathy associated with CIP requires a subtle assessment of both the intestinal smooth muscle and the enteric nervous system to identify the underlying pathology.

Abnormalities of the enteric nervous system in heterozygous endothelin B receptor deficient (spotting lethal) rats resembling intestinal neuronal dysplasia.

BACKGROUND: A homozygous mutation of the endothelin B receptor (EDNRB) gene in spotting lethal (sl/sl) rats leads to Hirschsprung's disease (HSCR) with long segmented aganglionosis. However, the effects on the development of the enteric nervous system (ENS) promoted by a heterozygous mutation of the EDNRB gene are not known. The present study aimed to describe and morphometrically assess the phenotypic abnormalities of the ENS in heterozygous (+/sl) EDNRB deficient rats in comparison with homozygous (sl/sl) EDNRB deficient and wild-type (+/+) rats. METHODS: The distal small intestine, caecum, and colon were obtained from sl/sl, +/sl, and +/+ rats. To demonstrate the three dimensional organisation of the ENS, the intestinal wall was microdissected into wholemounts and incubated against the pan-neuronal marker protein gene product 9.5. Assessment of the ENS included morphometric quantification of ganglionic size and density, the number of nerve cells per ganglia, and the diameter of nerve fibre strands within both the myenteric and submucous plexus. RESULTS: Sl/sl rats were characterised by complete aganglionosis resembling the same histopathological features observed in patients with HSCR. +/sl rats revealed more subtle abnormalities of the ENS: the submucous plexus was characterised by a significantly increased ganglionic size and density, and the presence of hypertrophied nerve fibre strands. Morphometric evaluation of the myenteric plexus did not show statistically significant differences between +/sl and +/+ rats. CONCLUSIONS: In contrast with sl/sl rats, +/sl rats display non-aganglionated malformations of the ENS. Interestingly, these innervational abnormalities resemble the histopathological criteria for intestinal neuronal dysplasia (IND). Although IND has been described in several intestinal motility disorders, the concept of a clearly defined clinical-histopathological entity is still controversially discussed. The present findings support the concept of IND based on clearly defined morphological criteria suggesting a genetic link, and thus may provide a model for human IND. Furthermore, the data underline the critical role of the "gene dose" for the phenotypic effects promoted by the EDNRB/EDN3 system and confirm that the development of the ENS is not an "all or none" phenomenon.

Oligoneuronal hypoganglionosis in patients with idiopathic slow-transit constipation.

PURPOSE: Several alterations of the enteric nervous system have been described as an underlying neuropathologic correlate in patients with idiopathic slow-transit constipation. To obtain comprehensive data on the structural components of the intramural nerve plexus, the colonic enteric nervous system was investigated in patients with slow-transit constipation and compared with controls by means of a quantitative morphometric analysis. METHODS: Resected specimens were obtained from ten patients with slow-transit constipation and ten controls (nonobstructive neoplasias) and processed for immunohistochemistry with the neuronal marker Protein Gene Product 9.5. The morphometric analysis was performed separately for the myenteric plexus and submucous plexus compartments and included the quantification of ganglia, neurons, glial cells, and nerve fibers. RESULTS: In patients with slow-transit constipation, the total ganglionic area and neuronal number per intestinal length as well as the mean neuron count per ganglion were significantly decreased within the myenteric plexus and external submucous plexus. The ratio of glial cells to neurons was significantly increased in myenteric ganglia but not in submucous ganglia. On statistical analysis, the histopathologic criteria (submucous giant ganglia and hypertrophic nerve fibers) of intestinal neuronal dysplasia previously described in patients with slow-transit constipation were not completely fulfilled. CONCLUSION: The colonic motor dysfunction in slow-transit constipation is associated with quantitative alterations of the enteric nervous system. The underlying defect is characterized morphologically by oligoneuronal hypoganglionosis. Because the neuropathologic alterations primarily affect the myenteric plexus and external submucous plexus, superficial submucous biopsies are not suitable to detect these innervational disorders.

Structural organization of the enteric nervous system in the cattle esophagus revealed by wholemount immunohistochemistry.

In ruminants the motility patterns of the esophageal tube are characterized by physiological regurgitations including both anterograde and retrograde peristaltic movements. These complex motor functions require an elaborated enteric nervous system (ENS) for the generation of the underlying intrinsic reflex circuits. The structural organization of the esophageal ENS was studied in fetuses of cattle (n=6) by means of wholemount preparations obtained from different segments of the esophagus. Demonstration of nerve cells, ganglia and nerve fibers strands (NFS) was achieved by immunohistochemistry using the general neuronal marker protein gene product (PGP) 9.5. The myenteric plexus represented the most prominent nerve network composed of differently shaped ganglia and interconnecting NFS. Frequenitly the myenteric ganglia were arranged in two separate layers interweaving with the adjacent muscle coat. From the cervical towards the thoracic segment of the esophagus the density and size of myenteric ganglia increased and the NFS exhibited thicker diameters. The submucosal and mucosal plexus consisted of NFS ramifying throughout the tela submucosa and the lamina propria mucosae. The networks showed no evidence of ganglia nor single nerve cells. The findings illustrate that intrinsic esophageal nerve cells are confined to the myenteric plexus. Since the esophageal tube has no secretory functions, secreto-motor neurons are not required in the submucosal and mucosal plexus layers. The structural organization of the intramural nerve networks--in particular the specific arrangement of the myenteric plexus--reflects the substantial contribution of the esophageal ENS to the coordination and mediation of esophageal motility in ruminants.

Estradiol has a direct impact on the exocrine pancreas as demonstrated by enzyme and vigilin expression.

BACKGROUND: Estrogen receptors have been found in the exocrine pancreas; however, the exact role of estrogen in pancreatic enzyme synthesis and secretion remains to be elucidated. Vigilin, a multi-KH domain protein, is part of a tRNA-containing ribonucleoprotein complex and may be a suitable marker for stimulation of the translational machinery. In the present study, we investigated the influence of estradiol and compared it to CCK on the expression of vigilin, trypsin and amylase in rat pancreatic acini. METHODS: Acini were isolated and incubated with CCK or estradiol. The change in amylase and trypsin levels in the medium and in cell extracts were determined using a photometric method. The change in vigilin mRNA and protein expression were determined by RT-PCR and Western blotting, respectively. RESULTS: Treatment of isolated exocrine pancreatic cells with estradiol caused stimulation of amylase and trypsin production and inhibition of secretion, while treatment with CCK showed only a minor effect on enzyme production and resulted mainly in a stimulation of secretion. Further we found an increase in vigilin mRNA and protein expression in acini stimulated with both CCK-8 and estradiol. CONCLUSION: Our data suggest that estradiol may play a role in inducing exocrine enzyme production but not secretion, and that vigilin, as a marker for translational activity, is stimulated in parallel to the pancreatic enzymes: amylase and trypsin.

Phenotype, intestinal morphology, and survival of homozygous and heterozygous endothelin B receptor--deficient (spotting lethal) rats.

BACKGROUND/PURPOSE: Spotting lethal (sl) rats, a model for Hirschsprung's disease, recently have been found to carry a deletion in the endothelin B (ET(B)) gene, causing functional lack of ET(B) receptors. The ET(B) receptor mediates, together with and in counterbalance to the ET(A) receptor, endothelin actions on vessels, cell proliferation, and migration. The authors investigated the effect of homozygosity (sI/sI) or heterozygosity (+/sl) on phenotype, intestinal morphology, and survival. METHODS: Weight, circumference, and serum albumin were measured. Histological tests of major organs and immunoperoxidase reaction for Peripherin, glial fibrillary acid protein (GFAP), and S-100 in small and large intestine were performed. Peripherin-immunostained sections of colon and jejunum were analyzed morphometrically. Screening for sepsis included search for enterocolitis, bacterial infection, endotoxin, and iNOS mRNA. RESULTS: Sl/sl rats died within 4 weeks of life, showing an early and a later death group. Serum albumin levels were decreased in sl/sl rats, whereas signs of sepsis were rare. Immunostaining uncovered alterations in nerve and glial cells in the whole gut of sl/sl rats, and to a subtle degree also in +/sl rats, which appear clinically normal. Morphometric quantification yielded statistically significant alterations in sl/sl rats only. No obvious abnormalities were found in other organs. CONCLUSIONS: Sl/sl rats die from malnutrition rather than sepsis, too early for ischemic complications to occur. Rats of the later death group are a suitable model for studying the ET8 receptor in vivo. Subtle abnormalities in the enteric nervous system of heterozygous rats underline the critical role of the "gene dose" for functional compensation.

[Disorders of intestinal innervation as a possible cause for chronic constipation]. / Intestinale Innervationsstörungen als mögliche Ursache der chronischen Obstipation.

The gastrointestinal tract contains the largest amount of nerve cells apart from the central nervous system constituting together with glial cells the enteric nervous system (ENS). The morphology of the ENS is characterized by intramurally located ganglionated and non-ganglionated plexus of different structure. The diversity of neurotransmitters synthesized by the different nerve cell types as well as the complex neuronal circuits establish the basis for the mediation of a coordinated intestinal motility. Subsequently abnormalities of the ENS may cause severe constipation. The most acknowledged intestinal innervation disorder represents aganglionosis (Hirschsprung's disease) characterized by the absence of intramural nerve cells and the hypertrophy of nerve fiber bundles within the affected intestinal segment. Non-aganglionic intestinal innervation disorders include intestinal neuronal dysplasia (IND), hypoganglionosis and heterotopic ganglia. The pathogenesis of intestinal neuronal malformations is mainly attributed to development disorders of the ENS, in part caused by genetic defects. Furthermore, the ENS can sustain damage during the postnatal period by ischemic, inflammatory, autoimmunological processes or neurotoxic agents. The histopathological diagnosis of intestinal innervation disorders is achieved by enzyme- and immunohistochemical methods. The examination of the ENS can be carried out on mucosal, deep submucosal or full-thickness biopsies using serial transverse sections as well as on intestinal whole-mount preparations allowing a three-dimensional demonstration and assessment of the intramural plexus. Structural abnormalities of the myenteric and submucosal plexus and an abnormal content of neurotransmitters have been considered to be responsible for primary chronic constipation. However, until now no unified pathophysiological concept has been established due to the partly contradictory findings. Therefore, an important goal in patients with chronic constipation should be a detailed quantitative and qualitative assessment of the underlying neurohistopathology. The correlation of these data with functional parameters of intestinal motility may represent an useful tool for the differential diagnostic and therapeutic considerations.

Organization of the enteric nervous system in the human colon demonstrated by wholemount immunohistochemistry with special reference to the submucous plexus.

To demonstrate the normal topography and structure of the enteric nervous system (ENS) in the human colon, the colonic wall of patients (n = 10, mean age 66.3 years), who underwent abdominal surgery unrelated to intestinal motility disorders, was submitted to wholemount immunohistochemistry. The specimens were stretched out and separated into the tunica muscularis, the outer and inner portion of the tela submucosa and the tunica mucosa. Prior to the application of the neuronal marker Protein Gene Product (PGP) 9.5, the laminar preparations were pretreated with the maceration agent KOH. The plexus myentericus was composed of prominent ganglia and interconnecting nerve fiber strands (NFS) forming a polygonal network, which was denser in the descending than in the ascending colon. Nerve cells were observed within the ganglia as well as in primary, secondary and tertiary NFS. The latter ramified into the adjacent smooth muscle layers, which contained the aganglionated plexus muscularis longitudinalis and circularis. The submucous plexus comprised three nerve networks of different topography and architecture: the delicate plexus submucosus extremus consisted of parallel orientated NFS with isolated nerve cells and small ganglia and was located at the outermost border of the tela submucosa adjacent to the circular muscle layer. The plexus submucosus externus was closely associated with the plexus submucosus extremus and composed of larger ganglia and thicker NFS. The plexus submucosus internus was situated adjacent to the lamina muscularis mucosae and formed a network with denser meshes but smaller ganglia and NFS than the plexus submucosus externus. The NFS of the aganglionated plexus muscularis mucosae followed the course of the smooth muscle cells of the lamina muscularis mucosae. The honeycomb-like network of the plexus mucosus was located within the lamina propria mucosae and divided into a subglandular and a periglandular portion. Single and accumulated nerve cells were observed within the plexus mucosus as a regular feature. The findings confirm the complex structural organisation of the ENS encountered in larger mammals, in particular the subdivision of the submucous plexus into three different compartments. PGP 9.5-immunohistochemistry applied to wholemount preparations comprehensively visualized the architecture of the intramural nerve plexus in human colonic specimens. In addition to conventional cross-sections, this technique allows a subtle assessment and classification of structural alterations of the ENS in patients with colorectal motor disorders.

Ultrastructural features of nerve fascicles and basal lamina abnormalities in Hirschsprung's disease.

Although the pathogenesis of Hirschsprung's disease (HD) is not completely resolved, both the absence of nerve cells and the hypertrophy of nerve fascicles within the aganglionic colonic segment have been attributed to an abnormal intestinal microenvironment. Studies on animal models for HD revealed an altered ultrastructure of ingrowing nerve fascicles and abnormalities of basal laminae (BL). Therefore, the purpose of this study was to examine the ultrastructure of hypertrophied nerve fascicles in human HD with special reference to structural abnormalities of BL. Colonic specimens were obtained from patients with HD (n = 10) and controls (n = 5) and processed for electron-microscopical examination. Hypertrophied nerve fascicles were characterized by a prominent perineural sheath surrounded by large amounts of collagen bundles, a collagen-filled endoneurium, vasa nervorum and abundant glial cells of extraenteric ultrastructure, which were arranged in mono- or oligoaxonal units and frequently displayed different stages of myelination. As these ultrastructural characteristics resembled typical features of extrinsic nerves and were similar to those observed in subserosal nerves, the prominent intramural nerve fascicles were considered to be of extraenteric origin. Most likely their overabundance contributes to the functional obstruction of the terminal colon. Morphological abnormalities of BL encountered in the aganglionic colonic segment consisted of an extensive multilamination of BL surrounding glial processes and an irregular thickening of BL surrounding perineurocytes and smooth muscle cells of the muscularis mucosae. Similar alterations in BL have also been described in inherited peripheral and diabetic autonomic neuropathies and attributed to reactivated schwann cells. Thus, the overproduction of BL material within the hypertrophied nerve fascicles in HD may reflect an increased activity of proliferating glial cells. Since the smooth muscle cells of the muscularis mucosae showed abnormalities of BL similar to those observed in murine models for HD, it is suggestive that also in human HD the aganglionic colon is affected by a disturbed intestinal micro-environment impairing the neuronal colonisation and promoting the ingrowth of extrinsic nerves. The ultrastructurally observed alterations in BL of both neuronal and non-neuronal cells, as well as the increased amount of perineural and endoneural collagen provide further evidence that extracellular matrix components are abnormally distributed and overproduced within the bowel wall of patients affected by HD.

Structural differences of the enteric nervous system in the cattle forestomach revealed by whole mount immunohistochemistry.

The specific motility patterns of the forestomach of ruminants, composed of three structurally distinct compartments (rumen, reticulum, omasum), require an elaborate intramural innervation. To demonstrate the complex structure of the enteric nervous system (ENS), whole mount preparations obtained from different sites of the bovine forestomach were submitted to immunohistochemical procedures in which neuronal (protein gene product 9.5, neurofilament 200) and glial (protein S-100, glial fibrillary acid protein) markers were applied. Immunohistochemistry performed on whole mounts allowed a detailed two-dimensional assessment of the architecture of the intramural nerve networks. Generally, the myenteric and submucosal plexus layers were composed of ganglia and interconnecting nerve fiber strands, whereas the mucosal plexus consisted of an aganglionated nerve network. However, the texture of the ENS showed considerable regional differences concerning the ganglionic size, shape and density and the arrangement of nerve fiber strands. The myenteric plexus of the ruminal wall, showing a low ganglionic density and wide polygonal meshes, contrasted with the nerve network within the ruminal pillar which consisted of ropeladder-like nerve fiber strands and parallel orientated ganglia. The highest ganglionic density was observed at the reticular groove, the most prominent ganglia were found within the omasal wall. Branches of the vagal nerve frequently ramified within the myenteric plexus layers. The submucosal plexus of the rumen was divided into an external and internal layer; the reticular submucosal plexus followed the cristae and cellulae reticuli, the omasal submucosal (sublaminar) plexus showed intra- and parafascicular ganglia apart from ganglia located at the junctions of the nerve network. The mucosal plexus of the rumen consisted of thin nerve fascicles ramifying between the ruminal papillae, and reticular mucosal nerve fibers passed throughout the base of the cellulae reticuli. The highly specialised nerve network of the intralaminar omasal plexus showed radial and transverse trajectories reflecting the spatial arrangement of the intralaminar musculature. The demonstrated structural complexity of the ENS reflects the functional complexity of the ruminant forestomach and indicates the relatively high degree of autonomy in coordinating the different motility patterns required for the processing of the ingesta.

Morphologic alterations of the enteric nervous system and deficiency of non-adrenergic non-cholinergic inhibitory innervation in neonatal necrotizing enterocolitis.

Although damage to intramural nervous tissue should be expected in neonatal necrotizing enterocolitis (NNEC), as the pathology of NNEC is defined by substantial destruction of the bowel wall, only a few studies have considered its implication. Thus, the aim of the study has been to examine morphological alterations of the enteric nervous system (ENS) in intestinal segments affected by NNEC. Immunohistochemical methods allowed the demonstration of both neuronal and glial elements and the assessment of an altered localization of non-adrenergic non-cholinergic (NANC) inhibitory mediators within the intramural plexuses. Intestinal segments from patients with NNEC (n = 8) and control subjects (n = 3) were obtained and submitted to immunohistochemical examination incubating with antibodies against protein gene product (PGP) 9.5, protein S-100, vasoactive intestinal polypeptide (VIP) and nitric oxide synthase (NOS). The most severe damage of nervous tissue was found within the plexus mucosus and plexus submucosus internus. The ganglionated plexuses showed a loss ot both glial and nerve cells with various stages of cell deterioration and the formation of central lesions within the myenteric ganglia. The observed neuropathologic changes correspond to the group of acquired segmental hypoganglionosis. Specimens from patients with NNEC were also characterized by an absence of immunoreactive VIP and NOS in the plexus submucosus and within the circular muscle layer. The deficiency in NANC inhibitory innervation may contribute to the formation of functional obstructions following acute NNEC. Furthermore, it is likely that the neuropathological lesions induced in early stages of NNEC may result in dysfunctional intestinal motility facilitating intraluminal bacterial overgrowth and translocation, and therefore, possibly promote the self-perpetuating pathophysiologic cycle culminating in progressive NNEC. As an additional finding, two patients with NNEC showed typical features of intestinal neuronal dysplasia (IND). The association of NNEC and IND is reviewed in the literature and possible causalties are discussed.

Alterations of the enteric nervous system in neonatal necrotizing enterocolitis revealed by whole-mount immunohistochemistry.

Pathology reports on neonatal necrotizing enterocolitis (NNEC) rarely consider its effects on the enteric nervous system (ENS). Thus, the aim of this study has been to perform a two-dimensional assessment of neuropathologic lesions within the three ganglionated plexuses of the intestinal wall by means of whole-mount immunohistochemistry. Resected segments of ileum and colon affected by acute NNEC were submitted to immunohistochemical procedures using antibodies against neuronal (protein gene product 9.5) and glial (protein S-100, glial fibrillary acidic protein) proteins. Examination of the myenteric plexus and external submucosal plexus revealed a noticeable reduction in glial cells concomitant with the gradual deterioration of nerve cells, both findings predominating in the antimesenteric intestinal circumference, where ischemic lesions tend to appear first. The most severe damage of nervous tissue was observed in the plexus submucosus internus dependent on the depth of mucosal injury. The destroyed ganglia appeared like "empty baskets" (residual tangles) and housed deteriorated nerve and glial cells. Taking the anatomy of the intestinal vascular blood supply into consideration, the characteristic topography of neuropathologic lesions gives further support to an ischemic event within the cascade of different pathogenetic factors culminating in NNEC. Moreover, the demonstrated alterations of the ENS and their potential adverse effects on intestinal motility and neuroimmunologic interactions may contribute to the complex pathogenesis of NNEC, which remains a field of further investigation.

Production of trypsin by cells of the exocrine pancreas is paralleled by the expression of the KH protein vigilin.

Vigilin, a protein with a continuous series of 14 KH motifs, forms part of a multiprotein complex containing tRNA. Several lines of evidence have suggested that vigilin expression is enhanced in those cells which were actively engaged in protein synthesis. Accordingly, we show here by immunoelectronmicroscopy a close association of vigilin with the rough endoplasmic reticulum in rat pancreatic cells. Histological examination of these cells furthermore demonstrates the highest intensity of vigilin staining in the perinuclear, intranuclear, and basolateral regions where the endoplasmic reticulum is mainly amassed. In vivo challenge of starving rats fed prior to sacrifice raised in parallel the protein levels of both trypsin and vigilin when compared to unchallenged animals and was associated with enhanced expression of the vigilin gene. In contrast, in human and rat cell lines of pancreatic tumors with a constitutively high expression of vigilin no further stimulation by cholecystokinin treatment could be achieved. Our data provide circumstantial evidence that vigilin may play a crucial role in the ability of an organ, e.g., pancreas, to cope with the physiological demand to upregulate protein synthesis.

Distribution, morphology and projections of nitrergic and non-nitrergic submucosal neurons in the pig small intestine.

Sequential nitric oxide synthase immunohistochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry in pig small intestinal wholemounts revealed a complete colocalisation of the two nitrergic markers in submucous neurons. The external submucous plexus (ESP) contained nitrergic neurons throughout. In the internal submucous plexus (ISP) we found a moderate number of nitrergic neurons in the duodenum, while they were rare in the jejunum and nearly absent in the ileum. Combined NADPHd histochemistry and silver impregnation showed morphological ESP type III and VI neurons to be NADPHd positive whereas ESP type II, IV and V neurons were NADPHd negative. Axons of ESP type III, IV and VI neurons were often observed to enter interconnecting strands directed abluminally. ESP type II neurons projected mainly to the ISP. In special silver-impregnated wholemounts containing both external muscle layers and the abluminal part of the submucous layer, i.e. the myenteric plexus and the ESP, the great majority of impregnated axons within the interconnecting strands were observed to run between both plexuses and did not enter the circular muscle layer. We conclude that ESP type III and VI neurons are nitrergic while ESP type II, IV and V neurons are non-nitrergic. Furthermore, we assume that ESP type III, IV and VI neurons may represent a submucosal input to the myenteric plexus.