AChE-positive Nerve Fibers Research Articles

Intestinal Neuronal Dysplasia Type B: Timely Diagnosis and Management

Abstract A 23-year-old female presented to the emergency department with abdominal pain and constipation. She reported an extensive history of constipation. Imaging showed distended bowel without an obstruction. During laparotomy, no obvious mechanical cause was found and a total colectomy was performed. Gross examination of the colectomy specimen showed cobblestoning in a 10-cm portion of the colon. Microscopic examination demonstrated hypoganglionosis of the myenteric plexus, hyperganglionosis of Auerbach’s plexus, and “giant ganglia.” This case met the 2006 Meier-Ruge criteria and diagnosis of intestinal neuronal dysplasia (IND) was established. IND was first described in 1971. The frequency of IND varies widely due to lack of consensus of diagnostic criteria and has a geographic distribution with the highest rates in Europe, which correlates to published research in this region. Diagnostic criteria are controversial and require standardization. Meier-Ruge suggests a quantitative analysis of the number of ganglion cells in the submucosal plexuses and the identification of at least 20% giant ganglia with at least 8 neurons each, in 25 analyzed ganglia. More recent diagnostic criteria are conservative with differences, including (1) elimination of increased AChE-positive nerve fibers around submucosal blood vessels, (2) stipulation that a giant ganglion contains more than 8 ganglion cells, (3) the requirement that more than 20% of at least 25 ganglia be giant ganglia, and (4) diagnostic exclusion of patients <1 year. Clinical management is also controversial. Schimpl et al reported satisfactory results in 80% of 105 patients treated with dietary changes, cisapride, and laxatives with a median 7.2 years follow-up. Since colonic peristalsis is impaired by dysganglionosis, subtotal colectomy procedures have been widely successful. Clinicians should be mindful of IND in patients with a history of chronic constipation with abdominal pain and nonspecific imaging, as timely diagnosis can spare the patient from total colectomy and improve quality of life.

Cholinesterase activity in quail primary lymphoid organs

The present histochemical study was carried out to analyze the distribution and topography of acetylcholinepositive nerve fibers in the thymus and bursa of Fabricius of quails. The AChE-positive nerve fibers were demonstrated by direct thiocholine histochemical method. Nerve fibers present in the thymuses form periarterial nerve plexuses located mostly in the interlobular septa and on the cortico-medullary junction. Vessels-independent nerve fibers occur also in the parenchyma of thymic medulla, but rarely in parenchyma of the cortex. Within the connective tissue between the bursa of Fabricius and the wall of proctodeum we observed conspicuous AChE-positive ganglia, often in close relationship to greater arteries. Within the wall of bursa of Fabricius, AChE-positive nerve fibers create nerve plexuses around arteries. We observed a close relationship between lymphoid follicules in bursal submucosa and mucosa and AChE-positive nerve fibers. Nerve fibers create a ring around lymphoid follicles, but do not penetrate into the germinal center of the follicle. Arteries inside quail thymuses and bursae of Fabricius contain rich AChE-positive nerve plexuses, when compared to the veins, which have a very poor presence of AChE-positive nerves. According to lesser presence and decreased density of AChE-positive nerve fibers in older animals, we described age-dependent changes in both quail primary lymphoid organs.

Influence of surgical and chemical orchidectomy on weight and distribution of AChE-nerve fibres in thymuses of adult rats

The thymus is a crossroad between the immune and neuroendocrine systems. As such, it is innervated by acetylcholinesterase (AChE)-positive fibres of the vagus, the recurrent laryngeal and the phrenic nerves. It is well know, that the innervations density of the thymus increases with age. In our study, adult rats were orchidectomized (surgically and chemically by the application of a luteinizing hormone-releasing hormone). The density of AChE-positive nerve fibres in thymuses, as well as the weight of thymuses was examined. The authors found that both surgical and chemical orchidectomy result in macroscopic and microscopic regeneration of the atrophied thymuses. In regenerated rat’s thymuses after orchidectomy the density of AChE-positive nerve fibres was markedly higher in comparison with the control animals. The distribution, as well as the density of AChE-positive nerve fibres in regenerated thymuses after orchidectomy evokes the images of its innervations like in young animals before age-related involution. The authors also found a markedly higher weight of thymuses of orchidectomized rats in comparison with the control groups. In recent study the authors proved that after 8 weeks surgical orchidectomy leads to the regeneration of thymic AChE-positive innervation and chemical orchidectomy by administration of luteinizing hormone-releasing hormone after 4 weeks of adult rats.

Is acetylcholinesterase activity in neorectum after laparoscopic endorectal pull-through method for Hirschsprung’s disease a primary or a secondary condition?

Between 1996 and 2002, 22 cases of Hirschsprung's disease were treated laparoscopically by endorectal pull-through operation. The proximal margin of the resected bowel materials from these 22 patients were examined histologically by frozen sections at surgery and also after surgery using H&E staining, and complete resection of the aganglionic segment was confirmed. Eleven patients, in whom an informed consent was obtained at randomly, underwent suction biopsy from the pulled-though neorectum after surgery. Of these 11 patients, 2 revealed many AchE-positive nerve fibers in the lamina propria, the muscularis mucosa and around the ganglion cells in the submucosal plexuses. These structural changes were similar to intestinal neuronal dysplasia that was characterized by hyperganglionosis and other neuronal abnormalities. The remaining 9 revealed no AchE activity. Unexpectedly, the two patients showing AchE activity in their neorectum continued to have persistent constipation and were treated with laxatives or glycerin enema. It was suggested that their persistent constipation was caused by intestinal neuronal dysplasia showing an abnormal increase of AchE activity in spite of presence of ganglion cells of the neorectum after surgery, but it was uncertain that they were primary condition as a HaIND or secondary reactions after surgery.

Histochemical study of Dom mouse: a model for Waardenburg-Hirschsprung’s phenotype

Background/Purpose The spontaneous mouse mutant Dominant megacolon (Dom) represents the model of the Waardenburg-Hirschsprung’s disease, a syndromic pathology, characterized by the association of pigmentation defects (PD), deafness, and Hirschsprung’s disease (HD). The defect in Dom mouse is caused by a spontaneous mutation of the gene encoding the Sry-related transcription factor Sox10. This mutation affects several aspects of neural crest development leading to combined enteric innervation and pigmentation defects, both in mouse and human. The purpose of this report is to define, by enzymo-histochemical techniques routinely used for the diagnosis of human Hirschsprung’s disease (AChE, LDH, NADPH-diaphorase), the innervative patterns of the affected gut. Methods Fifty-four siblings of Heterozygous Dom/+ mice underwent autopsy and were genotyped by direct sequencing of polymerase chain reaction (PCR) products for Sox10 mutations. The enteric nervous system of all the mice was studied by histochemical techniques indicated above. Results Genotyping showed that 43 mice were Dom/+ and 11 were Wild type +/+. Wild-type +/+ mice were used as control. The correspondence between genotype and at least 1 phenotypic aspect (PD or dysganglionosis) was present in 93% of cases (41 of 43). Among the Dom/+ mice, dysganglionosis was present in 79% of cases and PD in 90% of cases. Moreover, among Dom/+ mice, excluding those whose mantle was not evaluated as dead just after birth, PD and dysganglionosis (complete phenotype) were present in 68% of cases. Conclusions The histochemical methods that we used proved to be useful for identification of different aganglionic (AG), hypoganglionic (HG), and normoganglionic segments of Dom/+ mouse gut studied in longitudinal sections. Unlike humans, control mice ( Wild type +/+) presented a rich component of AChE nerve fibers, whereas Dom/+ mice with dysganglionosis presented a decrease in AChE-positive nerve fibers. These data confirm the variable phenotypic penetrance in heterozygous mice. Because dysganglionosis in this animal model ( Dom/+) was evident in 79% of cases (AG or HG), we concluded that Dom mice could represent important models for further experimental studies.

Localization of cholinergic innervation in guinea pig heart by immunohistochemistry for high-affinity choline transporters.

Previous studies have used acetylcholinesterase (AChE) histochemistry to identify cholinergic nerves in the heart, but this enzyme is not a selective marker for cholinergic neurons. This study maps cholinergic innervation of guinea pig heart using a new antibody to the human high-affinity choline transporter (CHT), which is present only in cholinergic nerves. Immunohistochemistry was used to localize CHTs in frozen and paraffin sections of heart and whole mount preparations of atrial ganglionated nerve plexus. AChE-positive nerve fibers were identified in sections from separate hearts for comparison. Control experiments established that the antibody to human CHT selectively labeled cholinergic neurons in the guinea pig. CHT-immunoreactive nerve fibers and AChE-positive nerves were very abundant in the sinus and AV nodes, bundle of His, and bundle branches. Both markers also delineated a distinct nerve tract in the posterior wall of the right atrium. AChE-positive nerve fibers were more abundant than CHT-immunoreactive nerves in working atrial and ventricular myocardium. CHT-immunoreactive nerves were rarely observed in left ventricular free wall. Both markers were associated with numerous parasympathetic ganglia that were distributed along the posterior atrial walls and within the interatrial septum, including the region of the AV node. Comparison of labeling patterns for CHT and AChE suggests that AChE histochemistry overestimates the density of cholinergic innervation in the heart. The distribution of CHT-immunoreactive nerve fibers and parasympathetic ganglia in the guinea pig heart suggests that heart rate, conduction velocity, and automaticity are precisely regulated by cholinergic innervation. In contrast, the paucity of CHT-immunoreactive nerve fibers in left ventricular myocardium implies that vagal efferent input has little or no direct influence on ventricular contractile function in the guinea pig.

Acetylcholinesterase (AChE) – Positive Innervation of the Guinea-Pig Spleen

The presence and intraorgan distribution of the acetylcholinesterase (AChE)-positive nerve structures in the guinea-pig spleen were studied by means of the direct thiocholine method. Visualized AChE-positive nerve fibres entered the guinea-pig spleen at its hilum in the vicinity of the splenic artery branches and intra parenchyma were gradually distributed to form thicker periarterial nerves and also fine adventitial nerve plexus. In described topography the AChE-positive nerve fibres were identified in association with the central artery running through the white pulp. Some of the perivascular nerve fibres associated with the central artery extended away and passed into the periarterial lymphatic sheath (PALS) to reach the marginal zone and in continuation entered into the mantle zone of lymphatic follicles. Several AChE-positive nerve fibres were seen in the red pulp but less in the splenic capsule. We did not find any AChE-positive nerve cells in the guinea-pig spleen.

Effect of interferon on human thymus microenvironment

Interferon, a thymic immunostimulator, was used with the aim of assessing the importance of adrenergic nerve fibers (ANF) and/or AChE-positive nerve fibers (AChENF) in the regulation of some immunological functions in humans. Thymic normal control fragments and/or thymic fragments of immunostimulated patients were removed during surgical biopsies. Thymic slices were stained with eosin-orange (for the recognition of microanatomical details of the microenvironment) and with Bodian's method for staining of nerve fibers. Histofluorescence microscopy was employed for staining ANF. AChENFs were detected by means of the direct-coloring thiocholine method. All images were submitted to quantitative morphometrical analysis and statistical comparisons of data. Moreover, the amount of proteins and noradrenaline was measured on thymic homogenates of the same patients. Treatment with interferon induces substantial changes in the thymic microenvironment, on ANF, on AChENFs and on the total amount of proteins and noradrenaline in thymic tissue homogenates. In conclusion immunostimulation with interferon induces substantial changes in the whole thymus and in its microenvironment, involving both sympathetic and parasympathetic nerve fibers.

Acetylcholinesterase distribution and refractory constipation - a new criterion for diagnosis and management.

To describe manifestations of acetylcholinesterase (AchE) activity in the bowel of patients presenting with refractory constipation and correlate them with outcome, rectal biopsy specimens (RBS) from 165 patients who presented with refractory constipation between 1988 and 1999 were examined. Age at biopsy ranged from 4 days to 17 years; 45 subjects were excluded because they satisfied diagnostic criteria for Hirschsprung's disease, intestinal neuronal dysplasia, or hypoganglionosis. Thirty-five autopsy subjects were used as controls. All RBS were compared and AchE activity was assessed in the lamina propria (LP), muscularis mucosae (MM), and around the submucosal vessels (V). Variations in AchE distribution were classified as grade I (no AchE-positive nerve fibers in the LP or MM), grade II (some positive fibers in the LP or MM), grade III (moderate positive fibers in the LP or MM), grade IV (many positive fibers in the LP, MM, or V), or grade V (fibrillar, foamy, or amorphous staining for AchE). All grade I (11/120) and V (12/120) subjects achieved normal bowel control with laxatives alone and all grade II subjects (58/120) did with laxatives and enemas. Grade III subjects (34/120) required addition of cisapride. All grade IV subjects (5/120) were unresponsive to conservative management and 4/5 were found to have a megarectum, which was treated surgically. AchE distribution correlated well with eventual outcome and requirement for surgery. AchE distribution could also be used to classify bowel motility disorders, and we suggest the term AchE-positive disease be used to describe them.

Adrenergic and Cholinergic Innervation of the Mammary Gland in the Pig

Adrenergic and acetylcholinesterase-positive (AChE-positive) innervation of the mammary gland in the sexually immature and mature pigs was studied using histochemical methods. Upon examining the adrenergic and cholinergic innervation, the adrenergic innervation was found to be much more developed. The majority of both sub-populations of the nerve fibres studied was localized in the subcutaneous tissue of the mammary gland. Adrenergic and AChE-positive nerve fibres also supplied structures of the nipple (subcutaneous tissue, blood vessels, smooth muscles fibres) and glandular tissue (blood vessels, lactiferous ducts). The glandular tissue contained the smallest number of adrenergic and AChE-positive nerve fibres. No distinct differences were observed in the adrenergic and AChE-positive innervation of the porcine mammary gland between the juvenile and non-pregnant adult animals.

Adrenergic and acetylcholinesterase-positive innervation of palatine tonsils in mammals

Innervation of human, feline and rabbit palatine tonsils was investigated. Adrenergic nerve components were visualized by formaldehyde-induced fluorescence of catecholamines and 5-HT, or by glyoxylic acid fluorescence, whereas acetylcholinesterase (AChE)-positive nerve structures were demonstrated by the direct thiocholine method. The largest density of adrenergic and AChE-positive nerve profiles was found in the adventitia of arterial branches in the fibrous capsula and septa, mainly in the form of periarterial nerve plexuses of different density. Fine nerve fibres lined the wall of small arteries which penetrated into extrafollicular lymphoid tissue and marginal layers of follicles. It is concluded that there are significant species-specific differences related to density, nature and topographic relations of adrenergic and AChE-positive nerve fibres in the various structural parts of palatine tonsils.

Intrinsic interrelation of lymphatic endothelia with nerve elements in the monkey urinary bladder

Histochemical staining techniques for 5'-nucleotidase (5'-Nase) and acetylcholinesterase (AChE) were undertaken to localize the lymphatic network and nerve plexus in the monkey urinary bladder. Abundant 5'-Nase-positive lymphatic networks were characterized by increased number of valve-like structures and decreased calibre of blind-ends from the subepithelium to the subserosa. AChE-positive nerve fibers were visible throughout the vesical walls as fine plexuses, the densest being the neuromuscular plexus among the detrusor muscle cells or in each muscle bundle. AChE-positive nerve fibers or terminals were more frequently discernible around blood vessels than around lymphatics, and showed more intimate association with the lymphatics in the muscularis than those in the subepithelium. The nerve terminals in the subepithelium were frequently separated from attenuated lymphatic endothelium by the long processes of fibroblasts or some connective tissue cells. An ultrastructural observation revealed that unmyelinated nerve fibers with numerous neurofilaments and neurotubules run in close apposition to the lymphatic endothelium. Noteworthily, fewer terminal varicosities containing numerous small agranular vesicles (30-50 nm) and mitochondria, partially or completely bare of their Schwann cell covering in the vicinity of the lymphatic endothelium, were found in the subendothelium of initial lymphatics than in collecting ones. These terminals were occasionally identified at a distance of 120-350 nm from the subendothelial aspect of valve-originating roots, although no direct innervation of the vascular muscle cells could be found. A loose fibro-elastic connective tissue was usually interlaced between glial cell covering and lymphatic endothelium. The intrinsic interrelation of the lymphatic wall with the nerve plexus implies that the twisted subendothelial nerve terminals might be involved in intramural lymph drainage of the bladder.

Acetylcholinesterase‐positive innervation is present at undifferentiated stages of the sea turtle Lepidochelis olivacea embryo gonads: Implications for temperature‐dependent sex determination

In embryos of different reptile species, incubation temperature triggers a cascade of endocrine events that lead to gonad sex differentiation. The cellular and molecular mechanisms by which temperature sets in motion this process are still controversial. Here, we begin evaluating the possible participation of the nervous system in temperature-dependent sex determination by showing the existence and origin of acetylcholinesterase (AchE)-positive nerve fibers in undifferentiated gonads of the Lepidochelys olivacea (L. olivacea) sea turtle putative male and female embryos, along the thermosensitive period for sex determination (TPSD; stages 20–27). AChE-positive nerve bundles and fibers were readily visualized until developmental stage 24 and thereafter. DiI injections and confocal imaging showed that some of these gonadal nerves arise from the lower thoracic and upper lumbar spinal cord levels, and might thus be sensory in nature. Because the vertebrate spinal cord is capable of integrating by itself thermoregulatory responses with no intervention of uppermost levels of the central nervous system, we also evaluated spinal cord maturation during the TPSD. The maturation of the spinal cord was more advanced in putative female than in male embryos, when sex determination is taking place for each sex; this process starts and ends earlier in male than in female embryos. Together these observations open the possibility that the spinal cord and the innervation derived from it could play a direct role in driving or modulating the process of temperature-dependent gonad sex determination and/or differentiation, particularly in female L. olivacea embryos. J. Comp. Neurol. 410:90–98, 1999. © 1999 Wiley-Liss, Inc.

Acetylcholinesterase-positive innervation is present at undifferentiated stages of the sea turtle Lepidochelis olivacea embryo gonads: implications for temperature-dependent sex determination.

In embryos of different reptile species, incubation temperature triggers a cascade of endocrine events that lead to gonad sex differentiation. The cellular and molecular mechanisms by which temperature sets in motion this process are still controversial. Here, we begin evaluating the possible participation of the nervous system in temperature-dependent sex determination by showing the existence and origin of acetylcholinesterase (AchE)-positive nerve fibers in undifferentiated gonads of the Lepidochelys olivacea (L. olivacea) sea turtle putative male and female embryos, along the thermosensitive period for sex determination (TPSD; stages 20-27). AChE-positive nerve bundles and fibers were readily visualized until developmental stage 24 and thereafter. DiI injections and confocal imaging showed that some of these gonadal nerves arise from the lower thoracic and upper lumbar spinal cord levels, and might thus be sensory in nature. Because the vertebrate spinal cord is capable of integrating by itself thermoregulatory responses with no intervention of uppermost levels of the central nervous system, we also evaluated spinal cord maturation during the TPSD. The maturation of the spinal cord was more advanced in putative female than in male embryos, when sex determination is taking place for each sex; this process starts and ends earlier in male than in female embryos. Together these observations open the possibility that the spinal cord and the innervation derived from it could play a direct role in driving or modulating the process of temperature-dependent gonad sex determination and/or differentiation, particularly in female L. olivacea embryos.

Morphology and histochemistry of the rabbit pancreatic innervation.

Stimulation of extrinsic nerves markedly alters pancreatic endocrine and exocrine secretion, yet little is known of the neurochemical organization and physiologic roles of specific neural pathways within the pancreas. Here we report histochemical staining for acetylcholinesterase (AChE), NADPH-diaphorase (NADPH-d), nitric oxide synthase (NOS), and several neuropeptides to identify the neurotransmitter content of rabbit pancreatic nerves. An extensive network of AChE-positive nerve fibers was found throughout the islets, acini, ducts, ganglia, and blood vessels. All pancreatic neurons were AChE positive, two thirds were NADPH-d positive, and many were NOS positive. Ganglia in the head/neck region were connected to the duodenal myenteric plexus by AChE- and NADPH-d-positive fibers, and NADPH-d-positive pancreatic neurons appeared to send processes toward both the duodenum and pancreas. Many pancreatic neurons were vasoactive intestinal peptide (VIP) positive, and VIP nerve terminals were abundant in ganglia, acini, islets, and ducts. Pituitary adenylate cyclase-activating peptide (PACAP-38)-positive fibers also were observed within acini and passing through ganglia. Substance P (SP)-, calcitonin gene-related peptide (CGRP)-, and dopamine beta-hydroxylase (DBH)-positive fibers were abundant along blood vessels and ducts, and varicose fibers were observed in pancreatic ganglia. Fine galanin-positive fibers were also occasionally observed running with blood vessels and through ganglia. Thus the rabbit pancreas receives a dense, diverse innervation by cholinergic, adrenergic, and peptidergic nerves and cholinergic pancreatic neurons, most also containing VIP or NOS or both, appear to innervate both endocrine and exocrine tissue, and may mediate local communication between the duodenum and pancreas.

Studies on the intrinsic nervous system of the wild rodent Calomys callosus digestive tract. II. The submucous plexus.

The submucous plexus of the normal small and large intestine of Calomys callosus was studied by NADH and AChE histochemical techniques and by transmission and scanning electron microscopy. The plexus contains (X +/- SD) 7,488 +/- 293 neurons/cm2 in the duodenum, 5,611 +/- 836 in the jejunum, 2,741 +/- 360 in the ileum, 3,067 +/- 179 in the cecum, and 3,817 +/- 256 in the proximal colon. No ganglia or nerve cell bodies were seen in the esophagus, stomach, distal colon or rectum. The neurons are pear-shaped with a round or oval nucleus and the neuronal cell profile areas were larger in the large intestine than in the small intestine. Most of the neurons display intense AChE activity in the cytoplasm. AChE-positive nerve fibers are present in a primary meshwork of large nerve bundles and in a secondary meshwork of finer nerve bundles. At the ultrastructural level, the ganglia are irregular in shape and covered with fibroblast-like cells. The nucleoplasm of the neurons is finely granular with a few condensations of chromatin attached to the nuclear envelope. In the neuropil numerous varicosities filled with vesicles of different size and electron densities are seen. The pre- and post-synaptic membrane thickenings are asymmetric. Characteristic glial cells with oval nuclei and few organelles are numerous. These data provide a detailed description of this submucosal meshwork.

Morphometry and acetylcholinesterase activity of the myenteric plexus of the wild mouse Calomys callosus.

The myenteric plexus of the digestive tract of the wild mouse Calomys callosus was examined using a histochemical method that selectively stains nerve cells, and the acetylcholinesterase (AChE) histochemical technique in whole-mount preparations. Neuronal density was 1,500 +/- 116 neurons/cm2 (mean +/- SEM) in the esophagus, 8,900 +/- 1,518 in the stomach, 9,000 +/- 711 in the jejunum and 13,100 +/- 2,089 in the colon. The difference in neuronal density between the esophagus and other regions was statistically significant. The neuron profile area ranged from 45 to 1,100 microns2. The difference in nerve cell size between the jejunum and other regions was statistically significant. AChE-positive nerve fibers were distributed within the myenteric plexus which is formed by a primary meshwork of large nerve bundles and a secondary meshwork of finer nerve bundles. Most of the nerve cells displayed AChE activity in the cytoplasm of different reaction intensities. These results are important in order to understand the changes occurring in the myenteric plexus in experimental Chagas' disease.

Abnormal internal anal sphincter innervation in patients with Hirschsprung's disease and allied disorders

The morphology of the intrinsic innervation of internal anal sphincter (IAS) in Hirschsprung's disease (HSCR) and allied disorders has not been clearly defined. At the time of IAS myectomy, specimens of the IAS were taken from four patients with HSCR, five patients with intestinal neuronal dysplasia (IND), five patients with IAS achalasia, and two patients with hypoganglionosis. Specimens also were taken from five normal controls. The specimens were examined using neural cell adhesion molecule (NCAM) immunohistochemistry, NADPH-diaphorase histochemistry, and acetylcholinesterase (AChE) histochemistry. The number of AChE-positive nerve fibers was markedly increased in the IAS of patients with HSCR, IND, and IAS achalasia compared with controls. NCAM and NADPH-diaphorase activity was absent or markedly reduced in the IAS of patients with HSCR, IND, and IAS achalasia. The IAS of patients with hypoganglionosis show markedly reduced NCAM and NADPH-diaphorase activity and occasional AChE-positive nerve fibers. These findings show that patients with HSCR, IND, hypoganglionosis, or IAS achalasia have abnormal innervation of the IAS and this may contribute to disturbances in gut motility in these conditions.

Initial increase and subsequent loss of vasoactive intestinal polypeptide immunoreactivity in acetylcholinesterase-positive neurons of mouse islets transplanted to the kidney.

Collagenase-isolated pancreatic islets from C57BL/6J mice were cultured overnight and transplanted under the kidney capsule of non-diabetic syngeneic hosts. Cryostat sections of grafts and fresh islets were stained for acetylcholinesterase (AChE) and vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI). Immediately after isolation, as well as 2-5 days after transplantation, VIP-LI- and AChE-positive nerve cell bodies were clearly seen in the periphery of the islets. Grafts 3-5 days old exhibited a transient and marked increase in VIP-LI nerve cell bodies and fibres. Seven days after transplantation VIP-LI nerve structures began to decrease in number and after 26-52 weeks they were no longer detectable. In contrast, AChE-positive nerve cell bodies and fibers, which showed a relatively constant pattern of distribution, were observed throughout the entire observation period. Restaining experiments demonstrated the coexistence of VIP-LI and AChE activity in the neurons. It is concluded that the grafts were extensively equipped with an intrinsic VIP-ergic and AChE-positive innervation. The initial, transient enhancement of VIP-LI expression probably reflects an adaptation of the neuro-insular complex to the preganglionic denervation, or to the ectopic environment, or both.

What are the diagnostic criteria for intestinal neuronal dysplasia?

The incidence of isolated intestinal neuronal dysplasia (IND) has varied from 0.3% to 62% of all suction rectal biopsies in different centres. The uncertainty regarding the incidence has resulted from the considerable confusion regarding the essential diagnostic criteria. In an attempt to clarify the diagnostic criteria for IND, we examined biopsy material from the following three groups using acetylcholinesterase (AChE) histochemistry: (1) full-thickness normal colon from 23 controls; (2) suction rectal biopsies from 9 patients who had isolated IND; and (3) full-thickness biopsies from 10 patients with Hirschsprung's disease (HD) who demonstrated IND in the proximal margin of the resected segment. Our data show that hyperganglionosis is the most consistent finding in both IND associated with HD and isolated IND. Other histochemical criteria of IND were dependent upon whether the biopsy was full-thickness or a suction rectal biopsy. Where full-thickness biopsies were available, giant ganglia and ectopic ganglion cells were seen in all cases. Increases in AChE-positive nerve fibres in the mucosa was a frequent finding in patients with IND diagnosed by suction rectal biopsies. We recommend that patients suspected to have IND on suction rectal biopsy should have a full-thickness biopsy for detailed examination of the submucous and myenteric plexuses.