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Biomedical subjects

T Miyano

Publications and source records attributed to T Miyano.

At least 73 records · Page 4Linked to original sources
PubMed1999

Modified soave pull-through for Hirschsprung's disease: intraoperative internal sphincterotomy.

BACKGROUND/PURPOSE: Anorectal achalasia (AA) may persist after pull-through (PT) for Hirschsprung's disease (HD), which may cause postoperative enterocolitis (POE) and constipation. The authors modified the Soave PT (modified Soave PT, MSPT) to eliminate AA, and present their results. METHODS: This was a 16-year retrospective review of 43 patients with histologically proven HD of the rectosigmoid or sigmoid colon treated by MSPT. The MSPT involves excision of the posterior rectal cuff and an intraoperative internal sphincterotomy, allowing the PT colon to fit nicely. RESULTS: Mean age at MSPT was 16.7 months (16 were < or =3 months old [37%]; 7 were neonates [16%]). Mean follow-up was 9.2 years. Six of 43 cases (14%) had preoperative enterocolitis; only 2 of 43 (5%) had single episodes of POE. At review, 37 of 43 were older than 4 years; 29 (78%) had normal bowel function (14 had experienced soiling after MSPT, which resolved after a mean of 6.4 years); and 8 (21%) had problematic bowel function: 3 had occasional soiling, 1 had soiling only before defecation, 3 (8%) had constipation requiring laxatives or enemas, and 1 had significant soiling. CONCLUSION: MSPT is safe and may contribute to a reduction in the incidence of POE and constipation.

Digestive System Surgical Procedures↗
PubMed1999

Fetal esophageal transplantation in rats: a treatment option for long-gap esophageal atresia.

PURPOSE: The aim of this study is to determine if fetal esophageal transplantation can create viable esophageal tissue that may be used for treating long gap esophageal atresia. METHODS: Fetuses of gestational age 19 to 20 days were obtained by hysterotomy of pregnant 15-week-old Lewis rats. A 10-mm long segment of esophagus was obtained from each fetus by thoracolaparotomy and transplanted by wrapping it in a pouch created in the distal omentum of a 5-week-old Lewis rat (syngeneic transplantation: n = 15). Transplanted fetal esophageal grafts were harvested 10 days post-transplantation and fixed in 10% formalin and embedded in paraffin. H&E was used for histological examination, and PGP 9.5 (a neuronal antibody) was used for immunohistochemistry. Esophageal segments obtained from 10-day-old Lewis rats were used as controls. RESULTS: Thirteen of 15 (87%) grafts were transplanted successfully. The successfully transplanted graft could be mobilized to the thoracic cavity without tension or compromising of vascularity, because of the long omental pedicle. H&E staining and PGP 9.5 immunohistochemistry showed normal esophageal structure with intact esophageal nervous system, comparable with control specimens. CONCLUSIONS: Fetal esophageal transplantation produces viable esophageal tissue that may find application for treating long gap esophageal atresia providing rejection can be controlled adequately.

Animals↗
PubMed1999

Complications after sigmoidocolocystoplasty: review of 100 cases at one institution.

BACKGROUND/PURPOSE: The aim of this study was to review complications after sigmoidocolocystoplasty (SCP) performed at a single institution from 1984 to 1997. METHODS: The medical records of 100 patients who underwent SCP were reviewed retrospectively. RESULTS: Mean age at SCP was 10.8 years. Urinary control was improved in 75 cases and unchanged in 25. Post-SCP complications included death, abdominal wound infection or dehiscence, adhesive bowel obstruction, vesical calculi, vesicocolonic anastomosis stenosis, metabolic acidosis, and transient renal hypertension. Fifty-one patients underwent ureteric re-implantation (URI) at the time of, or before, SCP, and 7 had recurrence of VUR post-URI (spontaneous regression in 6); 3 patients had new onset of contralateral VUR post-URI (spontaneous regression in 2). Transient pleural effusion was seen after reinsertion of ventriculo-pleural shunts to ventriculo-thoracic in 12 cases, but there was no incidence of infection. Squamous metaplasia of the bladder mucosa was identified in 5 patients on routine mucosal biopsy results but resolved in all cases after regular bladder irrigation was commenced. Preoperative constipation or fecal incontinence was better managed after sigmoidectomy in approximately one third of cases (38%). CONCLUSIONS: SCP with or without URI can improve the quality of life of patients with neurogenic or small-capacity bladder, but it can be associated with long-term complications. Regular bladder irrigation is recommended to maintain bladder mucosa integrity.

Adolescent↗
PubMed1998

Establishment of the enzyme-linked immunosorbent assay for connective tissue growth factor (CTGF) and its detection in the sera of biliary atresia.

Connective tissue growth factor (CTGF) is a mitogenic, chemotactic, and cell matrix-inducing factor for fibroblasts. We generated murine monoclonal antibodies against CTGF and established a sandwich enzyme-linked immunosorbent assay (ELISA) for detection of CTGF. By using the ELISA, we confirmed that CTGF was specifically induced in human fibroblasts by TGF-beta but not by PDGF, FGF, IGF-I, or EGF. We also found that the serum levels of CTGF were significantly correlated with the progression of hepatic fibrosis in biliary atresia. These results indicated that CTGF is potentially a useful parameter for monitoring certain types of fibrotic disorders.

Biliary Atresia↗
PubMed1998

Clinical significance of plasma endothelin levels in patients with biliary atresia.

Biliary atresia (BA) is the end-result of a destructive inflammatory process that affects intra- and extrahepatic bile ducts, leading to fibrosis and obliteration of the biliary tracts with the development of biliary cirrhosis and portal hypertension (PH). Endothelins (ET) are 21-amino-acid peptides of endothelial origin with potent vasoconstrictor activity that bind to various cells of the liver. Nothing is presently known about plasma ET levels in BA. The aim of this study was to determine the clinical significance of plasma ET levels in patients with BA after hepatic portoenterostomy (Kasai's procedure) and to correlate these with liver function tests (LFT) and PH. We measured plasma concentrations of ET in 19 patients with BA (5 boys and 14 girls; mean age 11.6 +/- 5.5 years) after portoenterostomy and 10 age-matched controls. Patients were grouped according to outcome based on LFT: group A consisted of 9 patients with an "unfavorable outcome" and Group B 10 patients with a "favorable outcome". The plasma ET levels were measured using a highly sensitive and specific enzyme immunometeric assay (EIA). No patient had ascites or hepatorenal syndrome. Plasma ET levels were significantly higher in patients with BA than in controls (3.42 +/- 0.42 vs 1.75 +/- 0.39 pg/ml, respectively; P < 0.01) and in patients in group A than in group B. (3.75 +/- 0.25 vs 3.06 +/- 0.23 pg/ml, respectively; P < 0.01). In group A, plasma ET levels were higher in patients with PH (n = 4) than in those without PH (n = 5) (3.99 +/- 0.06 vs 3.64 +/- 0.22 pg/ml, respectively; P < 0.05). We conclude that plasma ET levels are high in patients with BA, especially those with severe biliary cirrhosis, and that ET may partially contribute to development of PH in BA. The results of the present study also suggest that plasma ET concentrations may be a useful marker in the follow-up of patients with BA.

Biliary Atresia↗
PubMed1998

Management of vesicoureteral reflux secondary to neurogenic bladder.

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.

Adolescent↗
PubMed1998

Pedicled external spermatic fascia flap for urethroplasty in hypospadias and closure of urethrocutaneous fistula.

PURPOSE: To prevent the development of urethrocutaneous fistula after urethroplasty for hypospadias or recurrence after closure of a urethrocutaneous fistula, the authors developed a new simple technique wherein the readily available external spermatic fascia (ESF) surrounding the testis and cord is used as a pedicled blanket flap to cover the neourethra or the site of closure of a urethrocutaneous fistula. RESULTS: In three patients who had urethroplasty for hypospadias incorporating our ESF flap procedure, no urethrocutaneous fistula developed. It was also effective for closure of urethrocutaneous fistula in five patients, some of whom had had recurrent fistula formation.

Adult↗
PubMed1998

Prognostic value of serum procollagen III peptide and type IV collagen in patients with biliary atresia.

BACKGROUND/PURPOSE: Progressive hepatic fibrosis, in spite of a successful Kasai procedure, is a major problem in patients with biliary atresia (BA). Early identification of patients at risk would be of great value. N-terminal procollagen-III peptide (PIIIP) (which is a marker of fibrogenesis and, therefore, of on going inflammation), and type IV collagen (found in basement membrane extracellular matrix), were measured in patients with BA to determine their potential as prognostic markers. METHODS: Thirty-three postoperative BA patients (11.0+/-3.7 years old) and 20 normal controls (10.5+/-2.8 years old) were studied. The BA patients were classified on the basis of their current liver function test results into three outcome groups. Group I (n = 9) had severe liver dysfunction, group II (n = 13) had moderate, and group III (n = 11) had good liver function. Serum P-III-P and type IV collagen values were determined by radioimmunoassays and one step sandwich enzyme immunoassay. RESULTS: In group I, serum PIIIP (1.93+/-0.64 U/mL) and type IV collagen levels (363.5+/-69.5 ng/mL) were significantly higher than in group II (PIIIP [1.32+/-0.25 U/mL], type IV collagen [225.3+/-45.4 ng/mL]; P < .01). There were increased levels in serum PIIIP and serum type IV collagen in group II compared with group III (PIIIP [1.01+/-0.25 U/mL], type IV collagen [171.3+/-47.2 ng/mL]; P < .01). There were no significant differences in serum PIIIP and type IV collagen levels between group III and controls. CONCLUSION: The authors conclude that serum levels of PIIIP and type IV collagen may be useful in the long-term follow-up of BA patients after Kasai's portoenterostomy.

Biliary Atresia↗
PubMed1998

Correlation of prostaglandin E2 production and gastric acid secretion in infants with hypertrophic pyloric stenosis.

PURPOSE: The aim of this study was to evaluate the relationship between gastric acid secretion and prostaglandin E2 (PGE2) generation in gastric mucosa and the role of PGE2 in the pathogenesis of hypertrophic pyloric stenosis (HPS). METHODS: The authors measured the levels of PGE2 and gastric acidity in the gastric juice of HPS patients before and after a Ramstedt operation. RESULTS: The PGE2 concentration in the gastric juice of nine HPS patients before the Ramstedt operation was significantly higher than that of eight controls, and the concentration significantly decreased after the operation. A significant inverse correlation between the PGE2 concentration and the pH level in the gastric juice was shown in HPS patients before and after the operation. CONCLUSION: These results suggest that the enhanced generation of PGE2 in gastric mucosa in cases of HPS is a secondary phenomenon caused by hyperacidity and is not responsible for the pathogenesis of HPS.

Dinoprostone↗
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

Promotion of follicular antrum formation by pig oocytes in vitro.

Pig oocyte-cumulus-granulosa cell complexes (OCG complexes) from pig early antral follicles reorganise an antrum under the stimulation of FSH. The purpose of this study was to examine the role of the oocytes in antrum formation. In the first experiment, oocyte-cumulus complexes were removed from pig OCG complexes, and the antrum formation of parietal granulosa cells themselves (PGs) was examined. Antrum formation by sham-operated OCG complexes (OC/G complexes), in which the connections between the oocytes-cumulus complexes and the parietal granulosa cells had been disrupted, was also examined. The complexes were cultured for 8 days in collagen gels in the presence of 10 ng/ml FSH. Antra were formed in about 60% of the intact OCG complexes and the sham-operated OCG complexes, while only 20% of the PGs formed antra. In the second experiment, oocyte-cumulus complexes in the OCG complexes were replaced by denuded oocytes (O/G complexes) or Sephadex G-25 beads (B/G complexes) similar in diameter to the oocytes, and the two types of complexes were cultured under the same conditions. The O/G complexes formed antra to a similar extent as the OC/G complexes, whereas the B/G complexes scarcely formed any antra. The histological sections showed that the granulosa cells in the OC/G and O/G complexes were in intimate contact with each other and retained a shape similar to those in the ovarian follicles, while the granulosa cells in the PGs and B/G complexes became quite irregular in shape. These results suggest that pig oocytes promote contact between the granulosa cells to induce antrum formation in a physiological manner.

Animals↗
PubMed1998

Spontaneous perforation of choledochal cyst: a study of 13 cases.

Of the 187 cases of infantile choledochal cyst treated at our hospitals, we encountered 13 with spontaneous perforation. All cases were under 4 years old. Eight cases were found to have biliary peritonitis and 5 had a sealed perforation. The shape of the extrahepatic bile duct was cystic in 8 and fusiform in 5. The cyst wall around the perforation was filmy and bile was found to be oozing through the thinned wall. Nine perforations were single while 4 cases had multiple perforations. Four of 17 perforations occurred in the posterior part of the cyst wall. Only 1 case of perforation was associated with protein plugs in a common channel, while 7 of the 10 cases of choledochal cyst requiring percutaneous biliary drainage due to signs of raised intrabiliary pressure were found to have protein plugs. We consider that spontaneous perforation of a choledochal cyst is not rare in infancy. The etiology of a perforation must be epithelial irritation of the biliary tract due to refluxed pancreatic juice caused by pancreatico-biliary malunion associated with mural immaturity due to infancy, rather than an abnormal rise in ductal pressure or congenital mural weakness at a certain point.

Abdominal Pain↗
PubMed1998

Effects of glycosaminoglycans on the development of in vitro-matured and -fertilized porcine oocytes to the blastocyst stage in vitro.

We examined the effects of four glycosaminoglycans (GAGs) on the development of in vitro-matured (IVM) and -fertilized (IVF) porcine oocytes to the blastocyst stage. IVM and IVF oocytes were cultured in Whitten's medium supplemented with hyaluronic acid, chondroitin sulfate A, dermatan sulfate, or heparin at 38.5 degrees C in an atmosphere of 5% CO2 in humidified air for up to 6 days. After 2 days in culture, 28-34% of the inseminated oocytes cleaved to the 2- to 8-cell stage, and the GAGs showed no significant effect on development. After 6 days in culture, blastocysts were observed in all groups. The percentage of blastocysts was significantly higher in hyaluronic acid-supplemented medium (14%) than in dermatan sulfate-supplemented (5%), heparin-supplemented (2%), or nonsupplemented (2%) media. In addition, the percentage of blastocysts was significantly higher in chondroitin sulfate A-supplemented medium (11%) than in heparin-supplemented and nonsupplemented media, although the number of blastocysts in chondroitin sulfate A was not significantly different from that in hyaluronic acid- and dermatan sulfate-supplemented media. There were no significant differences in the mean number of nuclei per blastocyst cultured in any group. The effects of hyaluronic acid and chondroitin sulfate A on development to the blastocyst stage was examined at various concentrations. After 6 days in culture, development of IVM and IVF oocytes to the blastocyst stage was best supported in 0.5 mg/ml hyaluronic acid-supplemented (17%) and in 0.1 or 0.5 mg/ml chondroitin sulfate A-supplemented (10% or 9%, respectively) media. It is concluded from these results that hyaluronic acid and chondroitin sulfate A supported the development of porcine oocytes matured and fertilized in vitro to the blastocyst stage.

Animals↗
PubMed1998

Esophageal strictures in children with recessive dystrophic epidermolysis bullosa: experience of balloon dilatation in nine cases.

BACKGROUND: Recessive dystrophic epidermolysis bullosa is a rare disorder characterized by extreme vulnerability of the squamous epithelium and mucous membranes. Minor trauma such as is caused by swallowing solid food is followed by blistering and scarring. Stricture formation at the pharyngoesophageal junction (C6 or C7) is the severest complication of this disease. METHODS: We evaluate the effectiveness of Microvasive Rigiflex balloon dilatation and extensive nutritional support as a primary treatment for this condition. Nine of 21 recessive dystrophic epidermolysis bullosa patients developed esophageal strictures at the level of the pharyngo-esophageal junction (C6). We treated them with intensive nutritional therapy followed by balloon dilatation, which produces longitudinal pressure and provides prompt relief from esophageal stricture. Eleven balloon dilatations have been performed in 9 patients. RESULTS: All patients had poor physical development and were severely malnourished; extensive nutritional support was required before treatment could begin. Balloon dilatation was performed once in seven patients and twice in two patients. No recurrent stricture formation was observed after balloon dilatation. CONCLUSION: Intensive nutritional support followed by balloon dilatation is the first choice of treatment for esophageal strictures complicating recessive epidermolysis bullosa. By following this regime, invasive surgery can be avoided.

Adolescent↗
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↗