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Dive into the research topics where Yasunobu Yamazaki is active.

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Featured researches published by Yasunobu Yamazaki.


Annals of Surgery | 1991

Intra-abdominal abscess in regional enteritis

Mauro B. Ribeiro; Adrian J. Greenstein; Yasunobu Yamazaki; Arthur H. Aufses

Intra-abdominal abscess (IAA) developed in 129 of 610 patients (21.2%) with Crohns disease confined to the small bowel. The location of the abscess was intraperitoneal (IPA) in 109 (17.9%) and retroperitoneal (RPA) in 20 (3.3%). There was a marked preponderance of male patients in the retroperitoneal group (ratio, 18:2) (p less than 0.0001). All 129 patients were operated on. Thirteen of one hundred nine patients (12%) with IPA were reoperated on for recurrent abscess, and nine (8.2%) for other reasons. External fistula developed in 24 patients (22%) after simple incision and drainage. Four (3.7%) died; one from hepatitis, and three from sepsis 5, 14, and 90 days after surgery. Of the 20 patients with RPA, two (10%) were reoperated on for recurrent abscess and four (20%) for other reasons. External fistula developed in two patients (10%). There were no deaths in this group. A small number of patients with IAA complicating regional enteritis had persistent sepsis causing postoperative death, which is, however, six times lower than in our comparable series of Crohns (ileo)colitis.


Surgery Today | 2000

Ileal duplication presenting as perforation: Report of a case

Kazuhiro Sakamoto; Seiji Hasegawa; Yasunobu Yamazaki; Tatsuo Makino; Takashi Suda; Toshio Imada

We describe herein the case of a 10-year-old boy in whom generalized peritonitis was caused by perforation of a tubular communicating ileal duplication cyst. Alimentary tract duplication cysts are rare congenital malformations, found primarily in children under the age of 15 years. The perforation was caused by heterotopic gastric mucosa within the duplication, giving rise to peptic ulceration in the adjacent intestinal mucosa. The presence of heterotopic gastric tissue is a primary cause of perforation that has been reported in as many as one third of patients with small intestine duplications; however, the detection of such ectopic tissue is timeconsuming, and there is no readily available method of diagnosing tubular duplications. Although very few patients present with peritonitis as the initial manifestation, the possibility should be borne in mind when diagnosing and planning therapy for such emergencies, particularly in children.


Surgery Today | 1983

Cancer in Inflammatory Bowel Disease

Adrian J. Greenstein; Akira Sugita; Yasunobu Yamazaki

ConclusionsCancer in inflammatory bowel disease is clearly increased in incidence in the intestinal tract, and probably in certain extraintestinal sites as well. The absolute number of patients developing such malignancies are low compared to overall cancer rates in the general population, but because of higher relative risks, younger ages of onset, distinctive clinicopathological features, and the difficulties of making a diagnosis, it is important that this complication of inflammatory bowel disease be widely appreciated. The prognosis today is no worse for colorectal cancer in ulcerative colitis, and only slightly poorer for Crohn’s colorectal cancer (especially for those occurring in excluded bowel) than forde novo cancers of the large bowel, but it remains exceedingly poor for small bowel cancers in Crohn’s disease. Surveillance can probably be advised for ulcerative colitis-related colorectal cancers, but there is still doubt as to whether it will be costeffective or how it will affect prognosis and survival. There is even greater doubt concerning its role in monitoring patients with Crohn’s colorectal cancer, or small bowel cancers. A cooperative study of endoscopic surveillance to diagnose dysplasia or malignant change in the mucosa of patients with Crohn’s disease has yet to be widely accepted as a worthwhile idea, much less actually designed or undertaken.


World Journal of Surgery | 2002

Changes in the response of neutrophils to endotoxin priming following major abdominal surgery

Yoshihiro Moriwaki; Mitsugi Sugiyama; Yukihiro Ozawa; Yasuhisa Mochizuki; Chikara Kunisaki; Noriyuki Kamiya; Yasunobu Yamazaki; Takashi Suda

Endotoxin (ETX) primes polymorphonuclear cells (PMNs) for the subsequent release of reactive oxygen species (ROS) in response to various stimulants such as phorbol myristate acetate (PMA). Although PMNs contribute to oxidative stress after stimulation by standard stimulants and after priming by many humoral factors, it is unknown whether the PMNs from patients at different postoperative times exhibit the same response to the same standard stimulant. We examined the response of PMA—induced production of ROS from PMNs at various intervals after major abdominal surgery in response to ETX priming. This study was a prospective clinical and laboratory study conducted over a 7-day period that involved 25 patients who were referred for elective major abdominal surgery (8 for gastric cancer, 9 for colonic cancer, 8 for rectal cancer). Blood was sampled on the day before operation and on postoperative days (PODs) 1, 3, and 7. For each sample we measured luminol-dependent chemiluminescence (CL), the time to peak counts (Tmax) of PMNs stimulated by PMA, and the serum ETX level. We studied the correlation between CL and ETX in samples from PODs 1 and 3. We also studied the CL of PMNs on PODs 1 and 3 preincubated (primed) with various concentrations of ETX (0, 20, 40, 60, and 100 pg/ml). We found that CL decreased on POD 1 compared with the preoperative level (p<0.05) because of the decreased Tmax. The level of CL per 1 µl of whole blood, however, was higher on PODs 1 and 3 than preoperatively. During this time, leukocytosis should compensate for the impaired production of ROS by an individual PMN. The serum ETX level was increased on POD 1 (p<0.05). There was a negative correlation between CL and ETX on POD 1 (correlation coefficient −0.62, p<0.01) and a positive correlation on POD 3 (0.61, p<0.01). CL on POD 3 was accelerated by ETX priming, but the CL on POD 1 was depressed by the priming using a low concentration of ETX. The mode of the response of PMNs to ETX priming differed between PODs 1 and 3. On POD 1 the responses of PMNs to environmental stimulants is suppressed, but by POD 3 these responses had increased.RésuméL’endotoxine (ETX) potentialise les leucocytes polvmorphes (LP) pour le largage ultérieur des types oxygène réactifs (TOR) en réponse à différents stimulants tels que l’acétate de phorbol mvristate (APM). Bien que l’APM contribue à une agression d’oxvdation après stimulation par des stimulants standards et après une potentialisation par plusieurs facteurs humoraux, on ne sait pas si les LP des patients à des moments différents de leur évolution ont les mêmes réponses aux mêmes stimulants. Nous avons examiné la réponse de la production des TOR à partir des LP à des moments différents après chirurgie abdominale majeure en réponse à la stimulation par des ETX. Cette étude prospective, clinique et paraclinique, sur une période de sept jours, comprenait 25 patients ayant besoin de chirurgie majeure (huit pour un cancer gastrique, neuf pour un cancer du côlon et huit un cancer rectal). On a prélevé du sang le jour avant l’intervention et aux jours postopératoires 1, 3 et 7. Pour chaque échantillon, nous avons mesuré le chimioluminescence luminol-dépendante (CL) ainsi que le temps pour atteindre un nombre maximal (TNmax) de LP stimulés par l’APM et les taux sériques d’ETX. Pour les échantillons des jours postopératoires 1 et 3, nous avons étudié la corrélation entre la CL et i’ETX. Nous avons également étudié la CL des LP des jours postopératoires 1 et 3, préincubés (potentialisés) avec différentes concentrations d’ETX (0, 20, 40, 60, et 100 pg/ml). La CL a diminué au Jl comparée au taux du jour préopératoire (p<0.05), provoquant une diminution du TNmax. Le taux de CL par 1 µL de sang entier, cependant, était plus élevé aux jours postopératoires 1 et 3 par rapport aux taux préopératoires. Pendant cette période, l’hyperleucocytose doit pouvoir compenser la mauvaise production de TOR par chaque LP. Les taux sériques d’ETX ont augmenté au jour postopératoire 1 (p<0.05). Il y avait une corrélation négative entre la CL et l’ETX au jour postopératoire 1 (coefficient de corrélation=−0.62, p<0.01) et une corrélation positive au jour postopératoire 3 (0.61 p<0.01). A partir du jour postopératoire 3, la CL a été accéléré par l’ETX mais déprimée lorsque la concentration en ETX était basse, et pour ce dernier, à partir du jour postopératoire 1. Le mode de réponse des LP à l’ETX différait entre les jours postopératoires 1 et 3. Au jour postopératoire 1, la réponse aux stimulants environmentaux est supprimée alors qu’au jour 3, ces réponses augmentaient.ResumenLa endotoxina (ETX) prepara las células poîimorfonucleares (PMNs) para la liberación subsiguiente de especies reactivas de oxígeno (ROS) en respuesta a diversos estímulos tales como el acetato de forbol miristato (phorbol myristate acetate, PMA). Aunque los PMNs contribuyen al estrés oxidative luego de ser estimulados por estimulantes estándar y de su preparación por múltiples factores humorales, se desconoce si los PMNs de los pacientes en diferentes periodos postoperatorios exhiben la misma respuesta al mismo estimulante estándar. Estudiamos la respuesta de la producción de ROS inducida por PMA de PMNs en varios intervalos de tiempo luego de cirugía abdominal en respuesta a la preparación por ETX. El presente es un estudio clínico prospectivo realizado durante siete años, que involucró 25 pacientes referidos para cirugía abdominal mayor (8 para cáncer gástrico, 9 para cáncer de colon y 8 para cáncer de recto). Se tomaron muestras de sangre el día preoperatorio y en el primero, tercero y séptimo días postoperatorios. En cada muestra se hizo la determinación de quimioluminiscencia luminol-dependiente (chemiluminescence, CL) así como en el momento de los recuentos máximos (Tmax) de PMNs estimulados por PMA y de los niveles séricos de ETX. En las muestras de los días primero y tercero postoperatorios, se estudió la correlación entre CL y ETX. También estudiamos la CL de los PMNs de los días primero y tercero postoperatorios, preincubado (primed) con varias concentraciones de ETX (0, 20, 40, 60, y 100 pg/ml). La CL disminuyó en el primer día postoperatorio en comparación con el nivel preoperatorio (p<0.05) como resultado de disminución del Tmax. Sin embargo, el nivel de CL por 1 µl de sangre total apareció elevado en los días primero y tercero postoperatorios. Durante este tiempo, la leucocitosis debe compensar la alterada producción de ROS por el PMN. El nivel sérico de ETX apareció aumentado en el primer día postoperatorio (p<0.05). Se demostró una correlación negativa entre CL y ETX en el primer día postoperatorio (coeficiente de correlación −0.62; p<0.01) y correlación positiva en el tercer día postoperatorio (0.61, p<0.01). La CL del tercer día postoperatorio apareció acelerada por la ETX, pero la CL del primer día postoperatorio apareció deprimida utilizando una concentración baja de ETX. El modo de acción preparatoria del PMN a la preparación de ETX fue diferente entre el primer y el tercer día postoperatorios. En el primer día postoperatorio las respuestas de los PMNs a los estimulantes ambientales estuvieron controladas hacia la supresión, y en el tercer día postoperatorio tales respuestas se vieron aumentadas.


Jpn J Gastroenterol Surg, Nihon Shokaki Geka Gakkai zasshi | 2000

Synchronous Gastric Adenocarcinoma and MALT-type Lymphoma with Helicobacter Pylori Infection. A Case Report.

Yoshinari Mochizuki; Tatsuo Makino; Yasunobu Yamazaki; Takashi Suda; Hiroshi Takemura; Nobuko Nakamura

症例は62歳の男性. 1997年5月より心窩部痛が出現. 近医で多発胃癌を疑われ, 当院を紹介受診. 血清学検査でHelicobacter pylori (以下, HP) 抗体が陽性であった. 上部消化管造影検査と胃内視鏡検査では, 体上部前壁に3型の病変を前庭部後壁に2型の病変とその肛門側に小隆起を認めた. 生検の結果, 体上部の病変は低分化腺管癌であり, 前庭部の病変はともに異型細胞の増殖であった. また, 生検材料からはHP の菌体も認めた. 同時性多発胃癌を疑い, 1997年8 月14日胃全摘術+脾臓摘出術を施行した. 病理組織学的検査では体上部の病変はpor2, t3 (se), n2 (#8a,#9,#10,#11), H0, P0, M0, stage IIIbであった. 前庭部の病変は胃MALT 腫であり, 深達度はsm, リンパ節転移はなかった. 胃癌と胃MALT リンパ腫の共在はまれとされるが, HP感染は胃癌や胃MALT リンパ腫発生の共通の危険因子であり, 互いの共存も念頭に入れた精査が必要である.


Jpn J Gastroenterol Surg, Nihon Shokaki Geka Gakkai zasshi | 1992

The Effect of Surgical Treatment of Growth Retardation in Children with Ulcerative Colitis.

Masayoshi Yamamoto; Akira Sugita; Yasunobu Yamazaki; Hirofumi Harada; Atsushi Takimoto; Katsuhiko Arai; Nobumichi Takeuchi; Naoki Ishiguro; Tsuneo Fukushima

横浜市大第2外科で治療した若年者の潰瘍性大腸炎25例中, 成長障害の合併は5例であり, それらに対して手術の効果を検討した.全例, 全大腸炎型で男女比は4: 1であった.手術適応は重症発作が2例, 難治例が3例であり, 3例に回腸直腸吻合術, 2例に回腸肛門吻合術を行った.手術時の平均年齢は14歳 (13~15歳), 発症より手術までの病悩期間は平均3.8年 (4か月~10年2か月) で, prednisolone投与量は平均10,066mg (1, 560~23,375mg) と多量であった.成長障害は身長, 体重を指標に.手術前と手術後平均3.8年後 (2~6年) とを比較した.手術前の身長は全例-1SD以下であったが, 手術後は3例が-1SD以内に改善し, 改善度は平均+0.8SDであった.手術前の体重は4例で-1SD以下であったが.手術後は3例が一1SD以内に改善し, 改善度は平均+0.9SDであった.重症例やステロイドを長期投与された成長障害をもつ若年者は術後に改善がみられ, 手術治療が有効であった.


Journal of Gastroenterology | 1995

Surgery for Crohn's anal fistulas

Akira Sugita; Kazutaka Koganei; Hirofumi Harada; Yasunobu Yamazaki; Tsuneo Fukushima; Hiroshi Shimada


The Japanese Journal of Gastroenterological Surgery | 2009

Parahiatal Hernia Complicated with Gastric Volvulus: Report of a Case

Satoshi Hasegawa; Yoshihiro Suzuki; Yukihiko Hiroshima; Yasunobu Yamazaki; Hideyuki Ike


Jpn J Gastroenterol Surg, Nihon Shokaki Geka Gakkai zasshi | 2007

Perforation of Gastric Ulcer into the Giant Cyst of the Liver: Report of a Case

Atsushi Ishibe; Hideyuki Ike; Yukihiko Hiroshima; Kenichi Matuzu; Yoshihiro Suzuki; Haruhiko Chou; Takashi Chishima; Yasunobu Yamazaki; Takashi Suda; Hiroshi Shimada


Jpn J Gastroenterol Surg, Nihon Shokaki Geka Gakkai zasshi | 1992

Urinary Changes after Proctocolectomy and Correction of these Changes with a Citrat Emixture.

Katsuhiko Arai; Akira Sugita; Naoki Ishiguro; Hiroshi Suwa; Yasunobu Yamazaki; Hirofumi Harada; Katsumi Go; Kazutaka Koganei; Tsuneo Fukushima

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Takashi Suda

Yokohama City University

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Yoshihiro Moriwaki

Yokohama City University Medical Center

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Akira Sugita

Yokohama City University

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Tatsuro Makino

Yokohama City University

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Tatsuo Makino

Yokohama City University

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Hideyuki Ike

Yokohama City University

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