Survival of neurons and interstitial cells of Cajal after autotransplantation of myenteric ganglia from small intestine in the lethal spotted mouse.

To avoid mutilating surgery in the treatment of distal aganglionosis, transplantation of autologous nervous elements to the affected intestine would be an attractive option. This treatment modality has emerged as a possible alternative for different brain disorders, mostly using fetal nervous tissue. Our objective was to evaluate whether myenteric ganglia (MG) and interstitial cells of Cajal (ICC) could survive a transplantation procedure and to evaluate possible differences between animals with distal colonic aganglionosis (lethal spotted mice) and their healthy littermates. Autologous transplantation of MG with adherent smooth muscle from small intestine to the subcapsular space of the kidney was performed in mice 3-12 weeks of age. The transplants were evaluated 5 to 9 days postoperatively. The presence of myenteric neurons in the transplants was registered using immunohistochemical detection of different neurotransmitters and markers. For identification of ICC antibodies against c-kit, a cell surface tyrosine-kinase receptor, were used. The transplants showed overall good survival. Neurons containing the general neuronal marker protein gene-related product, the neuronal nitric oxide synthesizing enzyme, and the neuropeptides vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide, calcitonin gene-related peptide, galanin, substance P, and neuropeptide Y could be shown throughout the transplants. ICC were consistently seen in the grafted tissue among the smooth muscle cells, particularly in the deep muscular plexus, and within the MG. No obvious differences in ICC or enteric neuronal tissue survival, or in the frequency of the various neuronal populations displayed could be detected between the two groups of animals. These findings support the use of autologous MG for further research on transplantation of enteric ganglia as a possible alternative treatment for colonic aganglionosis.

Functional and morphological examination of ganglionic and aganglionic distal gut from the lethal spotted mouse.

The aim of the study was to evaluate both morphologically and functionally the distal large intestine from the aganglionic lethal spotted (ls/ls) mutant mouse and their healthy litter mates. Immunohistochemically, the aganglionic murine distal large intestine showed an absence of nerve cell bodies, and a reduction or absence of nerve fibers displaying immunoreactivity (IR) for protein gene product (PGP), nitric oxide synthase (NOS), vasoactive intestinal peptide (VIP), substance P (SP), galanin and calcitonin gene-related peptide (CGRP), while in the ganglionic large intestine these neuronal populations were abundantly present throughout the gut wall. Pathological nerve trunks within the afflicted intestinal segment were found to harbour PGP- and neuropeptide Y (NPY)-IR nerve fibers. Smooth muscle specimens from the distal part of the murine distal large intestine were mounted as ring preparations in vitro and subjected to electrical field stimulation (EFS). EFS (4-20 Hz) caused a contraction in both ganglionic and aganglionic intestine. After pretreatment with atropine EFS (20 Hz) evoked a biphasic motor response, a relaxation followed by a contraction in control specimens, while no motor response was seen in aganglionic intestine. Addition of the NOS-inhibitor N-nitro-L-arginine methyl ester (L-NAME) caused per se a weak and transient contraction and reduced the amplitude of the EFS-induced relaxation in control intestine.

Personal decontamination after exposure to stimulated liquid phase contaminants: functional assessment of a new unit.

OBJECTIVE: To evaluate the efficacy of a decontamination station following exposure of volunteers to liquids with physical characteristics comparable to sarin and mustard gas. DESIGN: Twenty-four volunteers participated in the experiment which was performed with all staff wearing personal protective equipment including respiratory protection. The clothes, skin, and hair of the volunteers were contaminated with the simulated liquid phase contaminants, ethyl lactate and methyl salicylate. Sulphur hexafluoride gas was used to confirm the ventilation efficacy. Decontamination followed guidelines using a two-stage procedure. In the first chamber, all volunteers received a 3-minute shower with water at 30 degrees C, and their clothes but not their respiratory masks were removed. In the second, they were twice washed thoroughly with soap and water. After decontamination, the volunteers entered a third chamber for first aid measures. RESULTS: The air concentration of sulphur hexafluoride was reduced by 1:10,000 between the first and the third chambers. Ethyl lactate and methyl salicylate were measured in low concentrations in the third chamber. The capacity was 16 volunteers per hour with two-thirds on stretchers. After self-decontamination of the staff, the concentration of ethyl lactate increased significantly in the third chamber, consistent with residual ethyl lactate adsorbed by their underwear. This observation revealed a deficiency in the guidelines for self-decontamination. CONCLUSION: The capacity of the decontamination unit was found to be 16 volunteers per hour. The ventilation system and guidelines of the decontamination unit were demonstrated to be effective under the conditions examined. The self-decontamination of the staff was not optimal.

Balloon dilatation of oesophageal strictures in children.

During the last ten years balloon dilatation has become increasingly frequent in the therapy of oesophageal strictures, both for diagnosis and treatment. From 1983 to 1994, balloon catheterization was performed in 36 children (oesophageal atresia 28, tracheo-oesophageal fistula 3, congenital stenosis 1, acquired oesophageal stricture subsequent to gastro-oesophageal reflux 1, to caustic ingestion 3). Age at treatment varied from 2 weeks to 15 years. Thirty-nine (3 double) strictures were dilated a total of 171 times. Balloon dilatation was successful in 31 cases (79%). In two children therapy was changed to conventional bouginage and six strictures were resected. Advantages of the method may include that forces are exerted radially and that the procedure may be performed under better control since fluoroscopy is used.

Phenotype and functional properties of Vicia villosa agglutinin (VVA) binding T cells in patients with Crohn's disease: detection of contrasuppressor activity in patients lacking extra-intestinal manifestations, abscesses and fistulas.

Patients with active Crohn's disease (CD) have significantly increased numbers of T cells binding the Vicia villosa agglutinin (VVA). In patients with CD these VVA+ T cells express either the CD4 or the CD8 determinants, while in normal controls the majority of VVA+ T cells are CD8+. VVA+ T cells are significantly decreased in number in the inflamed mucosa as compared to normal controls. However, in only a subgroup of the patients do the VVA+ T cells show contrasuppressor activity with respect to the IgA and total Ig secretion upon co-cultivation with autologous B cells. Regression analysis revealed that in all data presented, contrasuppression activity correlates significantly with the absence of extra-intestinal symptoms, abscesses and fistulas.

Evidence for contrasuppression in patients with Crohn's disease.

Patients with Crohn's disease (CD) have elevated numbers of Vicia villosa agglutinin (VVA) binding cells in the peripheral blood. These cells represent a major subset of activated peripheral T cells. VVA binding T lymphocytes express either the T8 or the T4 determinant on their cell surface. In contrast in normal controls only a minor subset of peripheral T cell expresses binding sites for VVA. The majority of these cells coexpress T8. VVA binding T cells display no helper activity. Only in a subfraction of patients with CD and not in normal controls these cells mediate contrasuppressor activity for Ig and in particular for IgA. This subgroup of patients is characterized by the lack of extramucosal manifestations. It has now been shown that VVA binding T cells in their majority do not possess phenotypic features of helper inducer cells. This further supports the hypothesis of their involvement in contrasuppression. Moreover it was shown that IgA produced in the presence of VVA binding T cells is IgA1 and IgA2 (ratio 2:1) which are both modulated by VVA binding T cells.