Tamiki Yamataka

Abnormal distribution of intestinal pacemaker (C-KIT-positive) cells in an infant with chronic idiopathic intestinal pseudoobstruction

BACKGROUND Chronic idiopathic intestinal pseudoobstruction (CIIPO) is a rare syndrome with an obscure pathogenesis. The proto-oncogene c-kit encodes a transmembrane tyrosine kinase receptor C-KIT that is critical for the development of the interstitial cells of Cajal, cells that are regarded as being the pacemaker cells of the gut. Thus, C-KIT immunopositive (C-KIT-) cells in the muscle layers of the bowel are considered to be intestinal pacemaker cells. METHODS In this study, the distribution of intestinal pacemaker cells was examined for the first time using C-KIT immunohistochemistry in an infant with CIIPO. RESULTS C-KIT+ cells were found lying on either side of the border between the two muscle layers (longitudinal and circular) of the bowel and dispersed unevenly throughout both muscle layers. Myenteric plexuses were not demarcated by C-KIT+ cells. In contrast, in controls, C-KIT+ cells were located distinctly between the two muscle layers of the small bowel and dispersed evenly throughout the muscle layers of the colon. Myenteric plexuses were clearly demarcated by C-KIT+ cells. CONCLUSIONS This case demonstrates for the first time that there is abnormal distribution of intestinal pacemaker cells in CIIPO and provides new evidence that abnormal c-kit gene expression may be responsible for autonomic gut dysmotility. C-KIT immunohistochemistry may be an indispensable tool for diagnosing CIIPO.

Comparison of the pulmonary vasculature in newborns and stillborns with congenital diaphragmatic hernia

Abstract The purpose of this study was to compare structural changes in the pulmonary vasculature in newborns with congenital diaphragmatic hernia (CDH) complicated by persistent pulmonary hypertension (PPH) and stillborns with CDH. Victorian blue van Gieson (VVG) staining and immunostaining with anti-alpha smooth-muscle actin (ASMA) was performed on lung tissue obtained at autopsy from 23 newborns with CDH complicated by PPH, 7 stillborns with CDH, and 11 age-matched controls with sudden infant death syndrome (SIDS). The degrees of adventitial and medial thickness and area were measured in pulmonary arteries with an external diameter (ED) of <75 μm, 75–100 μm, 100–150 μm, 150–250 μm, 250–500 μm, and >500 μm by image analyzer and compared statistically. The degrees of adventitial and medial thickness and area were measured in pulmonary veins with an ED of <100 μm, 100–200 μm, and >200 μm by image analyzer and compared statistically. In order to determine whether the characteristic structural changes were size-related, each was related to ED. There was a significant increase in adventitial thickness and area in arteries of all sizes in both newborns and stillborns with CDH compared to SIDS patients (P < 0.05). The degree of medial thickness in newborns and stillborns with CDH was significantly increased compared to SIDS patients (P < 0.01). The degree of medial area was significantly increased for arteries with ED less than 100 μm (P < 0.05) in newborns and stillborns with CDH compared with SIDS patients. There was a significant increase in adventitial thickness and area in veins of all sizes in newborns with CDH compared to stillborns with CDH and SIDS (P < 0.05). The degree of adventitial thickness and area of pulmonary veins were similar in stillborns with CDH and SIDS. There were no significant differences in medial thickness of veins between the three groups. The presence of abnormally thick-walled pulmonary arteries in stillborns with CDH suggests that the intrapulmonary arteries in CDH may become excessively muscularized during fetal life, becoming unable to adapt normally at birth. The absence of structural changes in pulmonary veins in stillborns with CDH suggests that the pulmonary venous changes observed in newborns with CDH complicated by PPH occur after birth as a result of increases in transvascular pressure or a response to release of peptide growth factors.

Administration of antenatal glucocorticoids prevents pulmonary artery structural changes in nitrofen-induced congenital diaphragmatic hernia in rats☆

BACKGROUND/PURPOSE The aim of this study was to investigate whether maternal administration of dexamethasone has any effect on pulmonary vasculature in nitrofen-induced experimental congenital diaphragmatic hernia (CDH) in a rat model. METHODS A CDH model was induced in pregnant rats after administration of 100 mg nitrofen on day 9.5 of gestation. Antenatal dexamethasone, 0.25 mg/kg was given intraperitoneally on day 18.5 and 19.5 of gestation. The fetuses were divided into three groups: group I (n = 10), normal controls; group II (n = 10), nitrofen-induced CDH; group III (n = 10), nitrofen-induced CDH with maternal antenatal dexamethasone treatment. The fetuses were killed by cesarean section at term. Victorian blue van Gieson staining and immunostaining with antialpha smooth muscle actin (ASMA) were performed on lung tissue. The degree of adventitial thickness and area, and medial thickness and area were measured in pulmonary arteries by image analyzer and analyzed statistically. RESULTS There was a significant increase in adventitial thickness and area in group II compared with group I and III (P < .01). There was also a significant increase in medial thickness in group II compared with group I and III (P < .01). The degree of adventitial thickness and area and degree of medial thickness and area were similar in controls and maternal dexamethasone-treated CDH group. CONCLUSION This study demonstrates that antenatal maternal dexamethasone treatment prevents pulmonary artery structural changes in nitrofen-induced CDH in rats.

Hyaluronic acid: A specific prognostic indicator of hepatic damage in biliary atresia

BACKGROUND/PURPOSE Hepatic fibrosis can progress in biliary atresia (BA) and is associated with capillarization of hepatic sinusoids. The significance of serum hyaluronic acid (HA) as a noninvasive indicator of histological sinusoidal endothelial cell (SEC) damage and hepatic fibrosis in BA, is investigated. METHODS A total of 28 postoperative BA patients (mean age, 11.0+/-3.7 years) and 20 normal controls (mean age, 10.5+/-2.8 years) were studied. BA patients were divided into group I, good liver function (n = 8); group II, moderate liver dysfunction (n = 10); and group III, severe liver dysfunction (n = 10). Serum HA was determined using a one-step sandwich enzyme immunoassay, and liver histological damage was confirmed immunohistochemically using an antibody against factor VIII-related antigen (FVIIIRAg), which is specific for detecting damaged SEC. RESULTS Serum HA was significantly higher (P < .0001) in group III (84.6+/-36.5 ng/mL) than in group I (15.9+/-6.9 ng/mL) or group 11 (28.7+/-10.7 ng/mL). Although immunoreactive products of FVIIIRAg were abundant in group III, they were not detected in SEC from group II. CONCLUSION Serum HA may be of value for monitoring postoperative BA patients as a noninvasive indicator of SEC damage and progressive hepatic fibrosis.

Adventitial changes in pulmonary vasculature in congenital diaphragmatic hernia complicated by pulmonary hypertension

PURPOSE The purpose of this study was to characterize structural changes in the pulmonary vasculature in congenital diaphragmatic hernia (CDH) complicated by persistent pulmonary hypertension (PPH) with particular emphasis on adventitial thickness. METHODS Victorian blue Van Gieson (VVG) staining and immunostaining with antialpha smooth muscle actin (ASMA) were performed on lung tissues obtained at autopsy from 23 patients with CDH complicated by PPH and 11 age-matched control tissues of sudden infant death syndrome patients (SIDS). The degree of medial and adventitial thickening was measured in pulmonary arteries with an external diameter (ED) of less than 75 microm, 75 to 100 microm, 100 to 150 microm, 150 to 250 microm, 250 to 500 microm, and greater than 500 microm by IPS-4.01 image analyzer and compared statistically. The degree of medial thickening and adventitial thickening was also measured in pulmonary veins with an ED of less than 100 microm, 100 to 200 microm, and greater than 200 microm. To determine whether the characteristic structural changes were size related, each was related to ED. The area of adventitia and media of the pulmonary arteries and veins was measured using image analyzer. RESULTS There was a significant increase in medial and adventitial thickness in arteries of all sizes in CDH patients compared with controls (P < .01). The degree of adventitial area was significantly increased for arteries of all sizes (P < .01) and the degree of medial area was significantly increased only for arteries less than 100 microm size (P < .05) in CDH patients compared with controls. Calculation of the areas of the various components in the wall of each artery showed that for small arteries (<100 microm ED), the area of the lumen was smaller, and the areas of the media and adventitia were larger in CDH patients compared with controls (P < .01). There was a significant increase in adventitial thickness and area in veins of all sizes in CDH patients compared with controls (P < .01). The adventitial thickness of pulmonary veins were ED of less than 100 microm: CDH, 13.5 microm +/- 3.5; control, 9.21 microm +/- 2.0; ED 100 to 200 microm: CDH, 21.3 microm +/- 7.5; control, 13.0 microm +/- 4.8; ED greater than 200 microm: CDH, 34.4 microm +/- 12.5; control, 22.3 microm +/- 4.2. CONCLUSIONS The present study provides the first quantitative demonstration of structural alterations in pulmonary veins in addition to pulmonary arteries in CDH complicated by PPH. The structural remodeling of the pulmonary vein is perhaps as a result of an increase in transvascular pressure in PPH.

Management of vesicoureteral reflux secondary to neurogenic bladder

Abstract The authors encountered 108 cases of vesicoureteral reflex (VUR) in 231 cases of neurogenic bladder complicating spina bifida. Bladder compliance and percent volume (% vol.) were measured pre- and postoperatively and the patients were divided into four groups retrospectively according to the treatment. Ninety-five percent of low-grade VUR (grades I and II) disappeared spontaneously with conservative therapy or after augmentation cystoplasty without antireflux surgery; 92% of high-grade VUR (grade III or more) required ureteral reimplantation with or without bladder augmentation. Reflux did not recur in any case of ureteral reimplantation with bladder augmentation, however, it did recur in 20.4% of the cases of simple ureteral reimplantation without bladder augmentation. Percent volume and bladder compliance in cases of recurrence following simple ureteral reimplantation were significantly lower than in the successful cases. This study suggests that low-grade VUR can resolve spontaneously with conservative therapy or with a suitable maneuver to improve bladder compliance. High-grade reflux in cases of preserved bladder volume (% vol.>75%) and compliance (>7 ml/cmH2O) can be treated successfully with simple ureteral reimplantation, however, in cases of low volume (% vol.<60%) and low compliance (<4 ml/cmH2O), reimplantation with bladder augmentation is recommended.

Active collagen synthesis in infantile hypertrophic pyloric stenosis

Abstract M-57 antibody, which is capable of distinguishing newly-synthesized type I procollagen from fully-processed, mature collagen, was used to examine the expression of collagen synthesis in hypertrophic pyloric muscle from patients with infantile hypertrophic pyloric stenosis (IHPS). Seven specimens from IHPS patients were removed at the time of operation; age-matched normal pyloric tissue of 5 post-mortem cases was obtained as controls. Immunohistochemistry was performed using antibody of the amino-terminal end of the procollagen type I propeptide (M-57). Newly-synthesized procollagen (M-57) was strongly detected in both the connective tissue septa between circular muscle bundles, and among the circular-muscle fibers in patients with IHPS. No M-57 staining was observed among the circular-muscle fibers in controls. Our findings show that the hypertrophic circular muscle in IHPS is actively synthesizing collagen, and this may be responsible for the characteristic “firm” nature of the pyloric tumor.

The effect of anti-ICAM-1 monoclonal antibody treatment on the transplantation of the small bowel in rats

At present, organ transplantation has been conducted in various areas. But the most crucial problem is to find an efficient way to determine whether allograft rejection could be interfered by a novel approach, namely interference of adhesive interaction between cytotoxic cells and target organs with a monoclonal antibody (mAb) to intercellular adhesion molecule 1 (ICAM-1). We have studied the effect of anti-rat-ICAM-1 mAb on small bowel transplantation. Inbred Fischer and Lewis rats weighing 250 g were utilized. In allotransplantation, Fischer donor small bowel was transplanted to Lewis recipient. Group 1 consisted of untreated controls (n = 15). Group 2 was treated with the anti-ICAM-1 mAb (1 mg/kg/d intraperitoneally) for the first 5 days posttransplantation (n = 15). A dramatic inhibitory effect on allograft rejection was observed in the early stage of posttransplantation. On histological studies of grafted small intestine, group 2 showed normal morphological appearance while group 1 showed graft rejection until postoperative 5 days. However, changing around crypt cells and endothelial cells of microvasculature have appeared at 15 days of posttransplantation. These findings suggest that anti-ICAM-1 antibody is quite useful for delaying the occurrence of graft rejection in the early stage. Electron microscopic examination demonstrated the same results as conventional HE staining. Endothelial cells of the vessels and crypt cells may have an important role as target cells on graft rejection. Therefore, anti-ICAM-1 mAb may have potential as an alternative to conventional treatment for prevention of allograft rejection.

Prolongation of Rat Cardiac Allograft Survival by a Monoclonal Antibody: Anti-Rat Intercellular Adhesion Molecule-1

A mouse monoclonal antibody 1A29, which binds to the rat intercellular adhesion molecule-1 (ICAM-1), was studied for its effect on cardiac allograft survival. Expression of ICAM-1 was detectable only on vascular endothelium in normal heart, but was induced on myocardium associated with interstitial mononuclear cell infiltration during acute rejection. Treatment with monoclonal antibody 1A29 for 10 days after transplantation in 15 rats significantly prolonged allograft survival (mean(s.d.) 18(2) days; P<0.001), as compared with 15 isotype-matched control monoclonal antibody (mean(s.d.) 10(1) days) recipients. Five-day treatment with monoclonal antibody 1A29, when started at 5 days after transplantation (the time for which acute rejection is ongoing), also significantly extended the survival (mean(s.d.) 12(1) days; P<0.01) in seven rats. On histological examination, treatment with monoclonal antibody 1A29 reduced the degree of T-cell infiltration of both CD4+ and CD8+ subsets, and greatly reduced myocardial necrosis, vascular injury and intravenous thrombi. These results indicate that an anti-ICAM-1 monoclonal antibody can be used to prevent or treat acute rejection in the rat cardiac allograft model and suggest that human ICAM-1 is an important target for immunosuppression in clinical organ transplantation.

Lack of C-KIT+ mast cells and the development of idiopathic gastric perforation in neonates.

BACKGROUND/PURPOSE The proto-oncogene c-kit encodes a receptor tyrosine kinase C-KIT. W/Wv mice, which are devoid of C-KIT+ mast cells as a result of mutations in the c-kit gene, develop spontaneous gastric ulceration or perforation after day 7 of life at a high frequency, whereas normal litter mates do not. The authors hypothesized that a lack of C-KIT+ mast cells may be implicated in the development of idiopathic gastric perforation (GP) in neonates. METHODS Postmortem gastric wall specimens were taken from neonates who died of GP (idiopathic, n = 6; secondary, n = 4), and other causes (controls, n = 6). Specimens were taken at random from various sites in the stomach and labeled with antibody to C-KIT. The number of C-KIT+ mast cells from five random fields per specimen were compared under light microscopy (200x). RESULTS Overall, the number of C-KIT+ mast cells was significantly lower in gastric wall specimens from cases of idiopathic GP when compared with controls or cases of secondary GP irrespective of the sites of sampling (P<.01, analysis of variance test) with the distribution of cells being uniform and unique for each stomach. CONCLUSION A lack of C-KIT+ mast cells may underlie the development of idiopathic GP in neonates.