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Biomedical subjects

A Yamataka

Publications and source records attributed to A Yamataka.

At least 55 records · Page 3Linked to original sources
PubMed1998

Necrotizing enterocolitis and C-KIT.

BACKGROUND/PURPOSE: In the gut, C-KIT is important for immune system homeostasis, and C-KIT+ cells are known to increase during inflammation. Recently the authors identified that spontaneous intestinal mucosal erosion develops in C-KIT-depleted W/Wv mice after day 14 of life at a high frequency, whereas genotypically normal litter mates do not. The authors hypothesized that a lack of C-KIT may be implicated in the development of necrotizing enterocolitis (NEC). METHODS: Bowel specimens were taken during surgery or postmortem from nine cases of NEC (mean gestational age, 32.0 weeks), six age-matched cases of enteritis, and 10 age-matched controls. Specimens were formalin fixed, paraffin embedded, and labeled with antibody to C-KIT. The number of C-KIT+ cells from five random fields per specimen were compared under light microscopy (200x). Results were expressed as the mean +/- SD and compared using the analysis of variance (ANOVA) test. RESULTS: In enteritis, the number of C-KIT+ cells in the lamina propria and submucosa was significantly higher than in controls (P<.01) indicative of their involvement in inflammation. However, in NEC, the number of C-KIT+ cells in the lamina propria and submucosa was significantly lower than in controls (P<.05) despite histological evidence of inflammation. CONCLUSION: A lack of C-KIT+ cells may exert a causal influence on the development of NEC.

Analysis of Variance↗
PubMed1998

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.

Chronic Disease↗
PubMed1998

Multiple bowel atresias after syngeneic fetal small bowel transplantation in rats.

PURPOSE: The aim of this study was the assessment of atresia formation after syngeneic fetal small bowel transplantation (SBTx) to clarify its pathogenesis. METHODS: Seventy Lewis rat fetuses (gestational age, 18 to 19 days) were obtained by hysterotomy, and a 30-mm long section of small bowel was excised from each fetus. Each bowel graft was then transplanted into the space between the peritoneum and the rectus abdominis in 70 adult Lewis rats to expose the grafts to ischemic stress. Transplantation was successful in 63 of 70 grafts (90%). Successfully transplanted bowel grafts were harvested for macroscopic and microscopic examination 10 days posttransplantation. RESULTS: Of the successfully transplanted grafts, only two (3%) were atresia free; 127 atretic segments were found in the remaining 61 grafts. Twenty-four grafts (38%) had a single atresia comprised of membranous stenosis (MS) in two, membranous atresia (MA) in 10, and blind ends (BEs) with or without a connecting tissue remnant in 12. Thirty-seven grafts (59%) had multiple atresias, comprised of MS, MA, or both in six, BEs alone in seven, and a combination of BEs with MS or MA in 24. CONCLUSIONS: Our model is the first to succeed in inducing experimentally membranous stenosis and a high incidence (59%) of multiple atresias. These results suggest that bowel ischemia is responsible for multiple bowel atresia formation.

Animals↗
PubMed1998

[2D-FASE MRCP for pediatrics with congenital biliary dilatation: usefulness of non-breath-hold one-shot MRCP].

The usefulness of magnetic resonance cholangiopancreatography (MRCP) using the non-breath-hold one-shot technique was evaluated. Ten children suffering from congenital biliary dilatation (CBD) were included. Four of them were preoperative cases, and the remaining six postoperative. All MR images taken were compared with endoscopic retrograde cholangiopancreatography or intraoperative cholangiography. MR images using the non-breath-hold one-shot technique clearly showed the confluence of the common bile duct and the main pancreatic duct in seven of the cases. The confluence of the common bile duct and main pancreatic duct was obscure in the other three cases, mainly due to motion artifact. These results show that this non-breath-hold one-shot technique is useful for diagnosis and postoperative follow-up of congenital biliary dilatation in children.

Adolescent↗
PubMed1997

Modified Boerema technique for the closure of congenital abdominal wall defects to prevent incisional herniation and infection.

Tension and infection often cause wound dehiscence or incisional herniation after the fascial closure of congenital abdominal wall defects in neonates. To overcome these problems, a modification of the Boerema technique (a method for repairing large incisional hernia in adults) was applied to repair abdominal wall defects in 14 neonates. The efficacy of this technique is discussed in this report.

Abdominal Muscles↗
PubMed1997

Torsion of autotransplanted splenic tissue in Gaucher disease.

A 12-year-old girl who underwent a splenectomy followed by heterotopic splenic autotransplantation for treatment of hypersplenism secondary to Gaucher disease at the age of 3 years presented with acute lower abdominal pain. Radiological investigations were highly suggestive of torsion of the autotransplanted splenic tissue, which was confirmed during subsequent laparotomy. This is the first known report of torsion of autotransplanted splenic tissue.

Child↗
PubMed1997

Use of synaptophysin polyclonal antibody for the rapid intraoperative immunohistochemical evaluation of functional bowel disorders.

Intraoperative biopsies are essential for accurately distinguishing between Hirschsprung's disease (HD) and intestinal neuronal dysplasia (IND), and vital for determining the extent of abnormal bowel for surgical correction. IND can be associated with HD and can be a cause of postoperative complications. Routine hematoxylin and eosin (H&E) staining is sometimes inadequate for identification of ganglion cells in biopsy specimens and can be the cause of confusion. The authors found synaptophysin (SY) to be more specific as an indicator of abnormal bowel innervation and invaluable for surgical planning. Twenty patients (15 with HD, 3 with IND, and 2 with IND complicating HD) received biopsies intraoperatively. There was markedly reduced immunoreactivity (ie, a decreased number of SY-positive synapses) seen in the intestinal smooth muscle layers of transitional, aganglionic, and IND bowel segments, whereas immunoreactive synapses were abundantly present in the smooth muscle layers of ganglionic colon in HD. SY immunoreactivity also showed ganglion cells and hypertrophic nerve trunks clearly. Rapid SY staining is a simple and consistently reliable method for the intraoperative evaluation of the distribution of synapses in myenteric plexuses as well as smooth muscle layers.

Antibodies↗
PubMed1997

Intestinal pacemaker C-KIT+ cells and synapses in allied Hirschsprung's disorders.

The cause of bowel dysmotility in allied Hirschsprung's disorders (AHDs) such as hypoganglionosis (HYPG), immature ganglia (IMG) and neuronal intestinal dysplasia (NID) remains unexplained. Recent experimental studies in mice have shown that c-kit gene product positive (C-KIT+) cells are responsible for intestinal pacemaker activity and that c-kit is also closely involved in synapse formation. To further understand the pathophysiology of AHDs, the authors used immunohistochemistry to study the distribution of C-KIT+ cells and synapses in the muscle layers of normal bowel from controls (12 cases) and bowel from patients with AHDs (10 patients; mean age, 3.0 years; 5 HYPG, 3 NID, 2 IMG). Anti-human C-KIT serum and monoclonal antibody 171B5 (a novel marker of synapses) were used for visualization of C-KIT+ cells and 171B5+ synapses, respectively. In normal bowel from controls and patients with AHDs, moderate to many C-KIT immunoreactive (C-KIT-IR+) cells were observed in the muscle layers. Myenteric plexuses were clearly demarcated by C-KIT-IR+ cells. 171B5 immunoreactive (171B5-IR+) synapses were abundant in the muscle layers and within the myenteric plexuses. In contrast, the number of C-KIT-IR+ cells or 171 B5-IR+ synapses was reduced in the muscle layers of bowel affected by AHDs, except within the myenteric plexuses, where there was a moderate to large number of 171B5-IR+ synapses identified. A lack of intestinal pacemaker C-KIT+ cells may be of great significance with respect to the bowel dysmotility associated with AHDs and also to the abnormal synapse formation seen in the muscle layers of bowel affected by these disorders.

Adolescent↗
PubMed1997

Complications after cyst excision with hepaticoenterostomy for choledochal cysts and their surgical management in children versus adults.

The aim of this study was to review the cases 200 children and 40 adults who had cyst excision combined with hepaticoenterostomy (CEHE) for choledochal cyst, with particular emphasis on post-CEHE complications and their surgical management. Patients who had CEHE at the age of 15 years or less were defined as children, and those aged 16 years or older were defined as adults. The mean age when patients became initially symptomatic was 3 years in children and 26 years in adults. Eleven adults became symptomatic as children (< or = 15 years of age). The mean age of CEHE in children and adults was 4.2 years and 35 years, respectively. The time interval between the onset of initial symptoms and CEHE was significantly less in children than in adults (P < .0001). Of the 200 children, 176 had primary CEHE, and 24 had secondary CEHE converted from cystoenterostomy or other biliary surgery. Seventy children had intraoperative cyst endoscopy, which enabled us to examine the proximal intrahepatic bile ducts for stenosis and debris, and to wash out debris, protein plugs, and stones from the intrapancreatic ducts. Of the 40 adults, 22 had primary CEHE, 18 had secondary CEHE. The mean follow-up period was 10.9 years in children and 10.7 years in adults. The number of patients with post-CEHE complications in children and adults was 18 (9.0%) and 17 (42.5%), respectively. The post-CEHE complication rate in children was significantly lower than in adults (P < .0001). The 18 children had 25 post-CEHE complications such as cholangitis, intrahepatic bile duct stones, pancreatitis, stone formation in the intrapancreatic terminal choledochus or pancreatic duct, and bowel obstruction. Twenty-seven post-CEHE complications developed in the 17 adults including 2 cases of cholangiocarcinoma. There were no post-CEHE complications in the 70 children who had intraoperative cyst endoscopy. No stone formation was seen in the 145 children who had CEHE at the age of 5 years or less. Eight stone formations were seen in seven (12.7%) of the remaining 55 children aged over 5 years. Stones developed in seven (17.5%) adults. The incidence of post-CEHE stone formation in children aged 5 years or less was significantly lower than in other children and adults (P < .0001). Reoperation was required in 15 children: revision of hepaticoenterostomy in 4, percutaneous transhepatic cholangioscopic lithotomy (PTCSL) in 1, excision of intrapancreatic terminal choledochus in 2, endoscopic sphincterotomy of the papilla of Vater in 1, pancreaticojejunostomy in 1, and laparotomy for bowel obstruction in 6. Ten adults required reoperations: revision of hepaticoenterostomy in 2, PTCSL in 2, left hepatic lobectomy in 1, endoscopic sphincterotomy in 2, exploratory laparotomy in 2, and adhesiolysis in 1. The authors conclude that early diagnosis followed by CEHE is the treatment of choice for choledochal cyst, and intraoperative cyst endoscopy is recommended as a valuable adjunct to CEHE.

Adolescent↗
PubMed1997

Initial experience with non-breath-hold magnetic resonance cholangiopancreatography: a new noninvasive technique for the diagnosis of choledochal cyst in children.

BACKGROUND/PURPOSE: Magnetic resonance cholangiopancreatography (MRCP) is an emerging tool for the noninvasive evaluation of the pancreaticobiliary tree. METHODS: Non-breath-hold MRCP was used in three children to evaluate choledochal cyst; a first for this new modality of diagnostic imaging. In all cases, the intrahepatic and extrahepatic bile ducts, and the pancreatic duct were clearly visualized. RESULTS: Two cases were found to have a fusiform choledochal cyst, and non-breath-hold MRCP demonstrated pancreaticobiliary malunion and a long common channel. In the remaining case, the size and location of the huge cyst prevented visualization of any pancreaticobiliary malunion. Endoscopic retrograde cholangiopancreatography (ERCP) in this patient failed to provide any additional information. All patients underwent cyst excision with hepaticoenterostomy, and made an uneventful recovery. CONCLUSIONS: Our initial experience suggests that non-breath-hold MRCP is a reliable method for the diagnosis of choledochal cyst in children and could replace ERCP.

Age of Onset↗
PubMed1997

Pulmonary expression of vascular endothelial growth factor and myosin isoforms in rats with congenital diaphragmatic hernia.

Abnormalities of the pulmonary vasculature are well documented in cases of congenital diaphragmatic hernia (CDH). Vascular endothelial growth factor (VEGF), an angiogenic factor, is a recently described endothelial cell-specific growth factor. Myosin heavy chain (MHC) isoforms such as SMemb, SM1 and SM2 are important molecular markers used to study vascular smooth muscle cell differentiation. SMemb is predominantly expressed in immature smooth muscle cells (SMC), and SM2 is expressed in mature SMCs. The authors investigated the expression of VEGF and SMC differentiation in pulmonary vessels in CDH rat lungs and in controls. The lungs of nitrofen-induced CDH rat fetuses (n = 16, gestational age 16, 18, 20, and 22 days) were stained immunohistochemically using antibodies against VEGF, SMemb and SM2, while alpha-actin was used as a general marker of vascular smooth muscle cells. In the CDH group VEGF expression was negative in pulmonary vessels before birth, and in the control group VEGF was positive in smooth muscle cells in vessel walls from 20 days both in vessels at the hilum and in pulmonary parenchyma. In both control and CDH groups, SMemb expression was positive from 16 days' gestation. SM2 expression was negative in vessel walls during the prenatal period in both groups. Alpha-actin was localized in both lungs obtained from control and CDH groups in the lung hilum from 16 days and around peripheral vessels from 18 days. Differences in vascular smooth muscle cell differentiation were not observed between control and CDH lung. These findings suggest that differences in pulmonary vascular development exist between control and CDH rats for VEGF expression, and maturational differences in smooth muscle cell differentiation are not present. This role of altered endothelial cell growth might be related to the different pulmonary vascular reactivity present in CDH lungs.

Animals↗
PubMed1997

Choledochal cysts.

Choledochal cysts are a relatively rare abnormality in the West but are more common in the East. The etiology of choledochal cysts remains unknown. Recently, the incidence in neonates and young infants has been increasing due to advances in diagnostic imaging, including antenatal diagnosis. Choledochal cysts can present at any age, but the clinical manifestation differs according to the age of onset. Early diagnosis followed by cyst excision is the treatment of choice, even in asymptomatic children. Recently, attention has been paid to the treatment of intrahepatic and intrapancreatic ductal diseases such as intrahepatic duct dilatation, debris in the intrahepatic ducts, and protein plugs in the common channel. Intraoperative cyst endoscopy is strongly recommended as a valuable adjunct to cyst excision for the prevention of postoperative complications due to intrahepatic or intrapancreatic ductal diseases.

Adolescent↗
PubMed1996

Induction of immediate-early, ornithine decarboxylase and antizyme gene expression in the rat small intestine after transient ischaemia.

The expression of the immediate early genes (IEG)s c-fos, c-jun and zif/268, and the genes coding for ornithine decarboxylase (ODC) and its regulatory protein antizyme (AZ), was studied in rat small intestine following transient ischemia. The ischemic stimulus for 10 min alone did not alter the expression of these genes. A rapid and transitory induction of all IEG mRNAs occurred in a coordinated manner peaking at 30 min following recirculation and returned to basal levels 3 hr after recirculation. Protein products of the IEGs accumulated in the smooth muscle layer of the intestine by 2-3 hr after recirculation. Expression of both ODC and AZ mRNAs initially decreased to 70% of control levels 1 hr after recirculation but markedly increased at 2 to 4 hr after recirculation. The functional significance of these changes in gene expression in relation to tissue integrity and function after the ischaemia/reperfusion is discussed.

Animals↗
PubMed1996

Heterotopic splenic autotransplantation in a neonate with splenic rupture, leading to normal splenic function.

Loss of the spleen in infants and young children frequently results in overwhelming infection. To preserve splenic function, heterotopic splenic autotransplantation after splenectomy was performed on a newborn in whom the spleen was traumatized beyond repair because of birth trauma. Postoperatively, the percentage of pitted red blood cells that accurately reflects splenic reticuloendothelial function was normal. Splenic scintigrams obtained 3 weeks after the operation showed uptake by the reimplanted tissue. The otherwise mandatory long-term antibiotic prophylaxis could be reduced to 3 weeks in the newborn. At 7 years of age, the patient has not shown any increased susceptibility to infections.

Antibiotic Prophylaxis↗
PubMed1996

Lack of intestinal pacemaker (C-KIT-positive) cells in infantile hypertrophic pyloric stenosis.

The pathogenesis of infantile hypertrophic pyloric stenosis (IHPS) is not well understood. Recent studies have shown that the protonocogene c-kit is essential for the development or maintenance of autonomic gut motility, and also show that the c-kit gene protein product (C-KIT) positive cells in the mammalian gut are responsible for intestinal pacemaker activity. This study examines cells in the pyloric muscles of 23 patients (16 with IHPS, 7 controls) for the presence of the C-KIT (C-KIT+), using immunohistochemical techniques with antihuman C-KIT sera. In the controls, many C-KIT immunoreactive (IR+) cells were observed in the muscle layers. The myenteric plexuses were demarcated by a moderate number of C-KIT-IR+ cells. However, in the IHPS patients, C-KIT-IR were either absent or significantly reduced. No C-KIT-IR+ cells were found around the myenteric plexuses. These findings suggest that a lack of c-kit expression (as an indicator of intestinal pacemaker activity) in the hypertrophic pyloric smooth muscles may be an important factor in the pathogenesis of IHPS.

Biological Clocks↗
PubMed1996

Localization of intestinal pacemaker cells and synapses in the muscle layers of a patient with colonic hypoganglionosis.

Bowel dysmotility in association with hypoganglionosis remains unexplained. The proto-oncogene c-kit encodes a transmembrane tyrosine kinase receptor, and the c-kit protein-product (C-KIT) positive cells in the mammalian gut are responsible for intestinal pacemaker activity. The authors examined the localization of intestinal pacemaker cells in the muscle layers of a patient with colonic hypoganglionosis, using an antihuman C-KIT serum. In the normoganglionic ileum, many C-KIT immunoreactivity positive (C-KIT-IR+) cells were present in the muscle layers. In contrast, there were no C-KIT-IR+ cells in the muscle layers of the hypoganglionic colon. These findings suggest that a lack of c-kit expression may be responsible for the autonomic gut dysmotility in hypoganglionic bowels.

Colon↗
PubMed1996

Hepaticoenterostomy after excision of choledochal cyst in children: a 30-year experience with 180 cases.

In the long-term follow-up of patients with choledochal cyst, postoperative ascending cholangitis and/or stone formation in the intrahepatic bile ducts (IHBD) owing to anastomotic stricture present serious problems. To prevent the formation of anastomotic strictures, some surgeons recently have performed hepaticoenterostomy at the hepatic hilum, with a wide stoma, in all patients with choledochal cyst. The authors of the present study review the surgical procedures performed on a total of 180 children with choledochal cyst and discuss the treatment of choice, with special reference to the types of hepaticoenterostomy. The medical records and radiographs of all patients treated for choledochal cyst between January 1964 and December 1993 at the authors' institutions were reviewed. A total of 180 patients (mean age at time of surgery, 4.3 years) had follow-up for a mean of 11.1 years; 174 of them had cyst excision and hepaticoenterostomy, and six had cystoenterostomy. Of the 174 patients who underwent cyst excision, 171 had a conventional hepaticoenterostomy; two had an intrahepatic cystoenterostomy, and one had a hepaticoenterostomy at the hepatic hilum. IHBD stones with or without cholangitis developed postoperatively in four (2.3%) of the 171 patients who had conventional hepaticoenterostomy. The age at time hepaticoenterostomy of these four patients was 12, 7, 16, and 6 years. Postoperative IHBD stone formation and cholangitis were not found in 121 patients under 5 years of age. The authors recommend conventional hepaticoenterostomy as the treatment of choice for children with choledochal cyst. Hepaticoenterostomy at the hepatic hilum is indicated in only selected cases.

Adolescent↗