Yuji Nirasawa
Kyorin University
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Journal of Pediatric Surgery | 1998
Yuji Nirasawa; Toshiyuki Mori; Yasuo Ito; Hiroyuki Tanaka; Nobuo Seki; Yutaka Atomi
A large trichobezoar has been traditionally removed by open surgery, which has entailed an upper abdominal incision. With the advent of laparoscopic surgery, it became feasible to retrieve a foreign body from the stomach without the necessity of a large skin incision in the upper abdomen. A 7-year-old girl presenting with abdominal pain, nausea, and appetite loss was admitted and evaluated. Results of an upper gastrointestinal series showed a large mass in the stomach that extended into the duodenum. Endoscopical removal had been tried twice under general anesthesia and resulted only in the retrieval of the small portion of the trichobezoar in the duodenum; total removal seemed impossible with endoscopic techniques. Laparoscopic removal was then under-taken to avoid the surgical scar in the upper abdomen. The trichobezoar was successfully retrieved through a gastrotomy and removed via a small suprapubic incision. This approach may be the treatment of choice for future cases of trichobezoar when surgery is indicated.
Journal of Pediatric Surgery | 2000
Sachiyo Suita; Takao Okamatsu; Tetsuro Yamamoto; Noritoshi Handa; Yuji Nirasawa; Yasuhiro Watanabe; Jun Yanagihara; Eiji Nishijima; Seiichi Hirobe; Masaki Nio; Akira Gomi; Minoru Horisawa
BACKGROUND/PURPOSE The incidence of gastroschisis has increased over the past 3 decades in a number of countries. To elucidate the Japanese status of anterior abdominal wall defects, the Japanese Society of Pediatric Surgeons conducted a national survey in Japan. METHODS Information was obtained by sending out a questionnaire to 192 University Hospitals, Childrens hospitals, and general hospitals that each had more than 200 beds. The characteristics of the patients including the birth date, birth weight, gestations, rate of associated anomalies, rate of antenatal diagnosis and prognosis, maternal age, gravidity, history of smoking, and drug use were analyzed. RESULTS The authors obtained answers from 149 institutions, including 1,785 cases of omphalocele and 970 cases of gastroschisis, which were treated between 1975 to 1997. There was a significant increase in the incidence of gastroschisis, from 0.131 in 1975 to 1980, 0.269 in 1981 to 1985, 0.337 in 1986 to 1990, 0.461 in 1991 to 1995 to 0.467 per 10,000 births in 1996 to 1997. The incidence of omphalocele was 0.322 in 1975 to 1980, 0.567 in 1981 to 1985, 0.657 in 1986 to 1990, 0.741 in 1991 to 1995 to 0.626 per 10,000 births in 1996 to 1997, respectively. In the omphalocele group, 43.1% of the mothers were between 25 to 29 years of age, whereas in the gastroschisis group 42.6% of the mothers were 20 to 24 years of age. In the gastroschisis group, the number of primipara mothers was larger than that of multipara mothers. In the omphalocele group, approximately 10% of the mothers smoked during each period, whereas in the gastroschisis group, the percentage of smoking mothers increased chronologically from 12.9% in 1981 to 1985, 18.7% in 1986 to 1990, 23.5% in 1991 to 1995 and 29.3% in 1996 to 1997. A history of drug use by the mother was approximately 10% for both the omphalocele and gastroschisis groups. In the omphalocele group, 55.9% had associated anomalies against 21.8% in the gastroschisis group. Approximately 10% in the omphalocele group and less than 3% in the gastroschisis group showed chromosomal abnormalities. From 1986, a significant number of cases detected antenatally has been observed. CONCLUSIONS There have been substantial changes in the incidence of anterior abdominal wall defects, particularly regarding gastroschisis in Japan. The reasons for such changes are most likely multifactorial, further epidemiological monitoring is thus called for.
Journal of Pediatric Surgery | 1983
Masao Endo; Keizo Katsumata; Jotaro Yokoyama; Yasuhide Morikawa; Hiromichi Ikawa; Shoichiro Kamagata; Miwako Nakano; Yuji Nirasawa; Shigeru Ueno
This paper introduces a new operation for biliary atresia that establishes successful biliary drainage by extending the portahepatic dissection, and decreases ascending cholangitis by incorporating a nonrefluxing intussuscepted draining conduit. An analysis of the postoperative results is presented. The usual dissection of the portahepatis is extended to include the area between and beneath the branches of the right portal vein to incorporate all potentially usable remnants of the intrahepatic ducts. Ascending cholangitis is decreased by interposing an intussuscepted ileocolic segment between the portahepatis and the abdominal wall. This extended dissection of the portahepatis was performed since 1978 in 15 infants with noncorrectable biliary atresia, and bile drainage was achieved in all. In ten infants an intussuscepted ileocolic conduit was constructed. Ascending cholangitis in these ten infants has been either completely absent or easily controlled by antibiotics. The draining bile was highly concentrated due to the water-absorbing capacity of the interposed colonic segment; therefore, fluid and electrolyte disturbances, which develop frequently in patients having jejunal conduits, have never been encountered.
European Journal of Pediatrics | 2000
Tetsuo Sakai; Yuji Nirasawa; Yasuo Itoh; Akira Wakizaka
Abstract We report on mutation analysis of five genes involved in the receptor tyrosine kinase (RET) or the endothelin-signalling pathways in 28 sporadic Japanese patients with Hirschsprung disease. Analysis of DNA obtained from peripheral blood cells revealed six mutations in the RET proto-oncogene, four of which were disease-causing mutations in exon 9 (D584G), the splice donor site of intron 10 (+2T to A), exon 11 (A654T), and exon 12 (T706A). A heterozygous A to G transition was found in 47 bases upstream from the 5′ end of exon 2 in two HD patients but was also seen in one control subject (2/28; 1/24). A silent 2307T to G transversion was observed in exon 13. Two disease-causing mutations were detected in the endothelin receptor (EDNRB) gene, in the non-coding region of exon 1 (−26 G to A) and in exon 4 (A301T); the latter mutation was a novel one. One silent mutation was observed in exon 4 (codon 277). One heterozygous T to C mutation was found in the glial cell line-derived neurotrophic factor gene in 25 bases upstream of the coding region in exon 1. No nucleotide changes were detected in either the endothelin-3 or neurturin genes. Disease-causing mutation rates in the RET proto-oncogene and the EDNRB gene were estimated at 14.3% (4/28) and 10.7% (3/28), respectively. In addition to mutations in the RET and EDNRB genes, embryonic environmental factors and/or other genetic factors appear to be involved in the development of Hirschsprung disease. Further systematic studies of genetic variation in a large series of patients and controls are necessary for elucidating the pathogenesis of this disorder. Conclusion This study provides further gene alterations as disease-causing mutations in Japanese cases of sporadic Hirschsprung disease. However, the low mutation rate of the susceptibility genes may indicate that Hirschsprung disease arises from a combination of genetic and environmental factors.
Journal of Pediatric Surgery | 1986
Yuji Nirasawa; Jotaro Yokoyama; Hiromichi Ikawa; Yasuhide Morikawa; Keizo Katsumata
In order to assess abnormalities in the adrenergic mechanism in the intestine of Hirschsprungs disease, catecholamine concentrations, alpha-adrenoceptors, and the effect of electrical field stimulation were examined in aganglionic segments of colon or rectum. The aganglionic segment had a higher concentration of norepinephrine, assayed with high performance liquid chromatography with an electrochemical detector, whereas concentrations of epinephrine or dopamine were similar in normal and pathological segments. In four patients with extensive aganglionosis, the norepinephrine concentration in aganglionic colon segments decreased progressively in descending, transverse, and ascending colon. The tissue content of alpha-adrenoceptors and their affinity assayed from the specific binding of [3H]dihydro-alpha-ergocryptine appeared similar in normal and aganglionic segments of the rectosigmoidal colon. Electrical field stimulation of normal rectosigmoidal colon segments caused relaxation at low frequencies and contraction at a very high frequency. Relaxation was not abolished by blocking concentrations of propranolol or phentolamine. In aganglionic segments, the predominant response to electrical field stimulation was contraction, which was inhibited by either atropine or tetrodotoxin. These results indicate that an alpha-adrenergic system and cholinergic innervation apparently exist in aganglionic colon segments and that dysfunction of the colon appears to result from lack of a nonadrenergic inhibitory system.
Pediatric Surgery International | 1995
Yuji Nirasawa; Yasuo Ito
The accepted surgical treatment of unilateral large ovarian cystic teratoma has been oophorectomy, since there seems to be no apparent residual ovarian tissue to salvage or reconstruct. However, there is no guarantee that the other ovary will remain healthy. Therefore, we attempted to preserve the ovarian tissue and reproductive potential in a reproduction-preserving technique (cystectomy) performed in seven patients whose ages ranged from 2 to 14 years. A circumferential incision was made several centimeters from the hilum; the cyst was then removed from the hilar attachment and the capsule was repaired with absorbable sutures. The weight of the resected cysts ranged from 120 to 800 g. The time required for this operation was twice that of simple oophorectomy. Although the preserved hilum did not appear to contain recognizable ovarian tissue, normal oocytes were found in biopsied specimens taken from the thin hilar attachment. Ultrasonography performed 1 year after the operation revealed a normal, round-shaped ovary. For benign cystic teratoma of the ovary, cystectomy with preservation of the hilar structure should be tried.
Pediatric Surgery International | 1999
Yuji Nirasawa; Yasuo Ito; Hiroyuki Tanaka; Nobuo Seki
Abstract Urachal anomalies are frequent and may exhibit many anatomical variations. We report a case of a urachal cyst that had a sinus tract extending to the lower abdomen just above the pubic symphysis. Histologic examination of the specimens showed a squamous-epithelium-lined sinus tract and a columnar-epithelium-lined cyst, which suggested a developmental disorder. This may be an extremely rare case where the urachal cyst opened into the suprapubic sinus.
Journal of Molecular Neuroscience | 2001
Yuji Nirasawa; Yasuo Ito; Tomonori Fujiwara; Nobuo Seki; Hiroyuki Tanaka; Kimio Akagawa
To clarify the pathogenesis of excessive proliferation of extrinsic nerve fibers in the aganglionic colon of patients with Hirschsprung’s disease (HD), we immunohistochemically determined the role that exocytosis-related proteins play in the regulation of exocytosis using the antibody to HPC-1/syntaxin 1A, an exocytosis-related protein. Localization of exocytosis-related proteins (HPC-1/syntaxin 1A, N-ethylmalemide-sensitive fusion protein (NSF), soluble NSF attachment protein (SNAP), synaptotagmin, synaptobrevin, and synaptosome-associated protein 25 (SNAP-25)) was determined in surgical specimens obtained from normal proximal and aganglionic distal segments of the colon of 7 infant patients with HD. In the normal ganglionic colon, Auerbach’s plexus, Meisner’s plexus, nerve fibers in the muscle layer, and ganglion cells were immunopositive for all six kinds of antisera. In the aganglionic segments, numerous proliferated nerve fibers and hypertrophied nerve bundles were detected in the submucosal layer and myenteric layer by NSF, SNAP, synaptotagmin, synaptobrevin, and SNAP-25. However, HPC-1/syntaxin 1A was not recognized in the proliferated nerve fibers of the submucosal layer or the hypertrophied nerve bundles of the aganglionic segment. These findings show that immunoreactivity of HPC-1/syntaxin 1A was decreased in the affected bowel segments of patients with HD and may be related to the pathogenesis of extrinsic nerve-fiber proliferation in the aganglionic colon of HD.
Pediatrics International | 2012
Etsuji Ukiyama; Yuji Nirasawa; Yoshiko Watanabe; Atsushi Makino; Kentaro Masuko; Tomohiro Mochizuki; Yasuo Ito
Background: The Canadian Paediatric Triage and Acuity Scale (P‐CTAS) is used and modified at hospitals as a triage tool for pediatric patients before they are seen in emergency rooms. Pediatric surgery patients account for very few of the many patients in emergency departments, but they should be triaged as emergency or urgent because they might be candidates for surgery. Problems with and improvements for triaging pediatric surgery patients using the P‐CTAS were studied.
Histochemical Journal | 2002
Hiroyuki Tanaka; Yasuo Ito; Yuji Nirasawa; Hayato Kawakami; Hiroshi Hirano
The lectin-binding patterns in Auerbachs plexus in the distal portions of the rat colon from 15- to 21-day-old foetuses, newborns, and adults were examined by light and electron microscopy using 16 different lectins (ConA, RCA-1, WGA, PNA, SBA, UEA-1, DBA, LCA, PHA-L, DSA, GS-1, VVA, MPA, BPA, MAA, and PSA). The binding of ConA was shown to increase after day 19 of gestation in parallel with differentiation of Auerbachs plexus, whereas the staining intensity for DSA and RCA-1 increased after day 17 of gestation in accordance with the appearance of the plexus. At the electron microscopical level, DSA binding sites were observed to be localized mainly in the plasma membrane, Golgi apparatus, and nuclear membrane of nerve cells. Positive sites were also observed in the axolemma and in the plasma membrane of nerve cell processes, Schwann cells, and the surrounding smooth muscle cells. PSA, PHA-L, LCA, and WGA showed constant staining during the development after day 15 of gestation. Other lectins, most of which are specific for O-glycosidic mucin-type sugar residues, were essentially negative throughout the developmental stages. Moreover, N-glycanase digestion significantly diminished the positive reactions. N-linked oligosaccharides may thus play important roles in the development and maturation of the Auerbachs plexus, and may be involved in the developmental defect of the plexus, e.g. as occurs in Hirschsprungs disease.