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Featured researches published by Atsushi Nakamitsu.


Surgery Today | 2001

Kupffer Cell Function in Ischemic and Nonischemic Livers After Hepatic Partial Ischemia/Reperfusion

Atsushi Nakamitsu; Eiso Hiyama; Yuji Imamura; Yuichiro Matsuura; Takashi Yokoyama

Abstract Hepatic partial ischemic/reperfusion (I/R) injury, in which ischemic and nonischemic areas of the liver are likely to respond to each other after reperfusion, often occurs following hepatobiliary surgical procedures. Kupffer cells (KCs) are considered to play a major role in hepatic I/R injury. To study the activation of KCs in ischemic and nonischemic liver tissues following hepatic I/R, we investigated the superoxide generation and proinflammatory cytokine production of KCs in both liver parts in a rat model of partial hepatic I/R injury. KC superoxide generation in the ischemic and nonischemic lobes was upregulated 6 and 24 h after reperfusion, respectively, and then accelerated. The production of interleukin-1β (IL-1β) by KCs in the ischemic lobes increased during the early and late phases, 6 h and 48–72 h after reperfusion, respectively. A late increase in IL-1β production was also observed in the nonischemic lobes. Production of tumor necrosis factor-α (TNF-α) increased 6–24 h after reperfusion in both lobes. Upregulation of IL-1β mRNA in the ischemic lobes preceded the upregulation of TNF-α mRNA in both lobes. The hepatic partial I/R process results in activation of KCs in ischemic and nonischemic areas of the liver. The KCs are activated during the early phase after reperfusion in the ischemic areas, followed by activation in both the ischemic and nonischemic areas. This could be a cause of liver dysfunction after partial hepatic I/R during surgery.


Surgery Today | 1993

A study on postoperative enteritis caused by methicillin-resistant Staphylococcus aureus

Yoshio Takesue; Takashi Yokoyama; Takashi Kodama; Takahiro Santou; Atsushi Nakamitsu; Yoshiaki Murakami; Yuugi Imamura; Katsunari Miyamoto; Mitsuaki Okita; Hiroaki Tsumura; Toshiaki Hirata; Yuichiro Matsuura

We investigated the production of staphylococcal enterotoxin (SE) with respect to coagulase types by methicillin-resistant Staphylococcus aureus (MRSA). A total of 138 strains of MRSA, which were isolated from clinical materials in the surgical ward between 1983 and 1990, were studied. Coagulase type IV strains produced SE A only, whereas coagulase type II strains were classified into four groups by SE production: SE B producing strains (32.7%), SE C producing strains (29.8%), SE B and C coproducing strains (12.5%), and SE A and C coproducing strains (25.0%). Almost all of the organisms (nine of ten) which were isolated from the feces of patients with MRSA enteritis were SE A and C coproducing strains. The coincidence in time of the prevalence of MRSA enteritis and the isolation SE A and C coproducing strains also demonstrated that these strains caused MRSA enteritis. Although SE C producing strains and SE A and C coproducing strains were simultaneously prevalent in 1990, the former tended to be sensitive while the latter tended to be resistant to minocycline. Considering the variety of antibiotic sensitivity in coagulase type II strains, it is thus considered to be of critical importance for epidemiologic purposes to further characterize isolates by SE typing.


Gastroenterologia Japonica | 1991

Toxin involvement in methicillin-resistant Staphylococcus aureus enteritis in gastroenterological surgery

Yoshio Takesue; Takashi Yokoyama; Takashi Kodama; Takahiro Santou; Atsushi Nakamitsu; Yoshiaki Murakami; Yuuji Imamura; Katsunari Miyamoto; Mitsuaki Okita; Hiroaki Tsumura; Hideyuki Itaha; Yuichiro Matsuura

SummaryThe authors investigated the production of toxic shock syndrome toxin-1 (TSST-1) and staphylococcal enterotoxins (SE) by Methicillin-resistantStaphylococcus aureus (MRSA) isolates to clarify the pathogenesis of postoperative MRSA enteritis in patients undergoing gastroenterological surgery. Regarding the percentage of TSST-1-producing strains, there was a significant difference between type II MRSA strains (68.8%) and type IV MRSA strains (4.2%). Among type II strains, all those producing staphylococcal entorotoxin (SE) type C (SEC) also produced TSST-1, although other strains that produced SEB without TSST-1 were commonly isolated. Strains producing SEA were potent producers of SE which was considered to be responsible for enteritis. Therefore, we hypothesized that the strains which produced both SEA and SEC tended to cause enteritis associated with TSS-like symptoms owing to the high titer of these toxins.


Annals of Vascular Diseases | 2013

Thrombectomy under Cardiopulmonary Bypass for Inferior Vena Cava Thrombosis Induced by Liver Injury

Masaki Hamamoto; Taira Kobayashi; Hiroshi Kodama; Atsushi Nakamitsu; Masaru Sasaki; Yuta Kuroo

Inferior vena cava thrombosis (IVCT) caused by liver injury is a rare and challenging condition. A 32-year-old man sustained a severe liver injury in a traffic accident. Emergent thromboembolic procedure for the affected hepatic arteries was performed for hemostasis, resulting in hemodynamic stabilization of the patient. One month later, however, computed tomography (CT) showed liver congestion caused by IVCT from the suprahepatic IVC to the bilateral common iliac veins. As liver function deteriorated quickly despite heparin administration, surgical thrombectomy was performed under hypothermic circulatory arrest through sternotomy and laparotomy. After this operation, the liver was decongested and its function improved rapidly.


Surgery Today | 1992

Anomalous arrangement of the pancreaticobiliary ductal system without dilatation of the biliary tract.

Yoshiaki Murakami; Takashi Kodama; Yoshio Takesue; Mitsuaki Okita; Atsushi Nakamitsu; Yuji Imamura; Hitoshi Sewake; Hiroaki Tsumura; Katsunari Miyamoto; Yuichiro Matsuura; Takashi Yokoyama

A rare case of anomalous arrangement of the pancreaticobiliary ductal system without dilatation of the biliary tract (AAPBDS without DBT) associated with mucosal dysplasia of the biliary duct is described herein. A 53 year old male with a long history of diarrhea and right upper abdominal pain was diagnosed as having AAPBDS without DBT by endoscopic retrograde cholangiopancreatography and other examinations. Excision of the gallbladder and biliary duct with a Roux-en-Y hepatico-jejunostomy was performed and subsequent pathological examination of the surgical specimens showed mucosal hyperplasia of the gall-bladder and mucosal dysplasia of the biliary duct. Considering the dysplastic changes of the biliary duct as seen in our case, and the high incidence of AAPBDS without DBT developing into carcinoma of the biliary duct, being 12.2 per cent, we suggest that pancreaticobiliary ductal diversion with excision of the gall-bladder and biliary duct should also be performed for AAPBDS without DBT. However, further pathological investigations concerning the excised biliary duct in AAPBDS without DBT will be need to be carried out.


Surgery Today | 1993

Mucin-producing pancreatic tumors: A study of nuclear DNA content by flow cytometry

Yoshiaki Murakami; Takashi Yokoyama; Takashi Kodama; Yoshio Takesue; Mitsuaki Okita; Atsushi Nakamitsu; Yuji Imamura; Takahiro Santo; Hiroaki Tsumura; Katsunari Miyamoto; Yuichiro Matsuura

Nuclear DNA content in eight surgically resected mucin-producing pancreatic tumors (MPPT) consisting of two mucinous intraductal adenocarcinomas (MIDAC), two mucinous intraductal adenomas (MIDA), one mucinous cystadenocarcinoma (MCAC), and three mucinous cystadenomas (MCA) were measured by flow cytometry using paraffin-embedded tissue samples. The technique of Shutte was used for the preparation of paraffin-embedded tissue into single dissociated nuclei, while the method of Vindelov was used for staining the isolated nuclei with propidium iodine. Clinicopathologically, the four patients with MIDAC or MIDA were all male and had cystic lesions with a dilated pancreatic duct at the head of the pancreas, while the four patients with MCAC or MCA were all females and had cystic tumors at either the body or tail of the pancreas. All eight patients with MPPT had no metastasis to the regional lymph nodes and were all still alive without recurrence. In an analysis of nuclear DNA content, seven of eight patients had DNA diploid tumors while one patient with a MIDAC perforating the duodenum and choledochus had a DNA aneuploid tumor. Thus, these findings suggest that DNA diploid patterns in MPPT might be associated with a favorable prognosis in MPPT although some patients whose MPPT invaded the surrounding organs might have DNA aneuploid tumors.


World Journal of Gastroenterology | 2015

Successful treatment of conversion chemotherapy for initially unresectable synchronous colorectal liver metastasis

Kenta Baba; Akihiko Oshita; Mohei Kohyama; Satoshi Inoue; Yuta Kuroo; Takuro Yamaguchi; Hiroyuki Nakamura; Yoichi Sugiyama; Tatsuya Tazaki; Masaru Sasaki; Yuji Imamura; Yutaka Daimaru; Hideki Ohdan; Atsushi Nakamitsu

A 72-year-old woman with a sigmoid colon cancer and a synchronous colorectal liver metastasis (CRLM), which involved the right hepatic vein (RHV) and the inferior vena cava (IVC), was referred to our hospital. The metastatic lesion was diagnosed as initially unresectable because of its invasion into the confluence of the RHV and IVC. After she had undergone laparoscopic sigmoidectomy for the original tumor, she consequently had 3 courses of modified 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus cetuximab. Computed tomography revealed a partial response, and the confluence of the RHV and IVC got free from cancer invasion. After 3 additional courses of mFOLFOX6 plus cetuximab, preoperative percutaneous transhepatic portal vein embolization (PTPE) was performed to secure the future remnant liver volume. Finally, a right hemihepatectomy was performed. The postoperative course was uneventful. The patient was discharged from the hospital on postoperative day 13. She had neither local recurrence nor distant metastasis 18 mo after the last surgical intervention. This multidisciplinary strategy, consisting of conversion chemotherapy using FOLFOX plus cetuximab and PTPE, could contribute in facilitating curative hepatic resection for initially unresectable CRLM.


Surgery Today | 1995

Severity and predicted outcome of postoperative Pseudomonas aeruginosa infections

Takashi Kodama; Takashi Yokoyama; Yoshio Takesue; Mitsuaki Okita; Atsushi Nakamitsu; Eiso Hiyama; Yuji Imamura; Takahiro Santo; Yoshiaki Murakami; Hiroaki Tsumura; Kanae Shinbara; Katsunari Miyamoto; Naokuni Tatsumoto; Yuichirou Matsuura

The severity and predicted outcome of postoperative Pseudomonas aeruginosa (P. aeruginosa) infections (PPAI) was evaluated using a severity scoring system based on a simplification and modification of the APACHE II system. A total of 86 patients in whom P. aeruginosa was isolated from various sources were examined. PPAI developed in 50 patients, resulting in an overall mortality rate of 24%. An increased severity score (SS) correlated with an increased risk of developing PPAI. Thus, PPAI developed in 33% of the patients with an SS of 0–1, in 66.7% of those with an SS of 2–3, and in 100% of those with an SS of 6 or higher. Moreover, the mortality rate of the patients with an initial score of 6 or higher was 50%. The mean (±SD) initial severity score was 5.4±2.9 for survivors and 2.9±2.6 for nonsurvivors (P<0.01). In the patients who subsequently died, the SS remained high throughout the clinical course despite therapy, whereas in the survivors the SS decreased progressively, reflecting a favorable clinical course. These results suggest that our severity scoring system was useful for predicting outcome and monitoring the response of PPAI to therapy.


Asian Journal of Endoscopic Surgery | 2018

Inguinoscrotal hernia containing the urinary bladder successfully repaired using laparoscopic transabdominal preperitoneal repair technique: A case report: Inguinal bladder hernia

Tatsuya Tazaki; Masaru Sasaki; Mohei Kohyama; Yoichi Sugiyama; Shinnosuke Uegami; Ryuta Shintakuya; Yuji Imamura; Atsushi Nakamitsu

We report herein a patient with an inguinoscrotal hernia containing the urinary bladder. The hernia was safely repaired using the laparoscopic transabdominal preperitoneal repair technique. A 76‐year‐old man was admitted to our hospital with abdominal pain, vomiting, and diarrhea. His scrotum was swollen to fist size. Abdominal CT showed herniation of the sigmoid colon and the bladder into the right inguinal region, and his abdominal pain was attributed to incarceration of the sigmoid colon; this was manually reduced. About 1 month later, we performed transabdominal preperitoneal repair. After the direct hernial orifice was identified, the bladder was noted to be sliding from the medial side of the hernia; this was reduced. Peeling on the medial side was carried out to the middle of the abdominal wall, and the myopectineal orifice was covered with mesh. The patient was discharged on postoperative day 1.


Asian Journal of Endoscopic Surgery | 2016

Successful treatment of a patient with an infected urachal remnant via single-incision laparoscopic surgery: Report of a case.

Hiroyuki Nakamura; Akihiko Oshita; Yuji Imamura; Masaru Sasaki; Mohei Kohyama; Tatsuya Tazaki; Yoichi Sugiyama; Yutaka Daimaru; Atsushi Nakamitsu

We report on a case of an infected urachal remnant successfully treated via a single‐incisional laparoscopic technique. An 18‐year‐old woman was diagnosed with an infected urachal remnant. The center of the umbilicus was pulled and inverted from the skin, and the cephalic side of the urachus was dissected from the umbilicus. A single‐incision laparoscopic technique employing ultrasonic coagulating shears was used to dissect the urachal remnant from the stump of the umbilicus to the caudal end. Single‐incision laparoscopic excision of the urachal remnant can be used successfully as a minimally invasive technique with optimal cosmetic outcomes.

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Yoshio Takesue

Hyogo College of Medicine

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Katsunari Miyamoto

Memorial Hospital of South Bend

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