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Biomedical subjects

N Tanaka

Publications and source records attributed to N Tanaka.

At least 307 records · Page 17Linked to original sources

Generalized peritonitis due to spontaneously perforated pyometra presenting as pneumoperitoneum: report of a case.

We report a rare case of generalized peritonitis due to a ruptured pyometra in an 86-year-old woman, and also conduct a review of the previous Japanese literature. The patient presented with muscle guarding and rebound tenderness. Computed tomography (CT) disclosed a cystic mass in the peritoneal cavity, in which an air-fluid level was noted. Pneumoperitoneum around the uterus due to gas production of anaerobic bacteria was noted on a CT. At laparotomy, the uterus was markedly enlarged with a necrotic area on the uterine fundus, which was found to be perforated. A supravaginal hysterectomy and drainage were performed. We found only eight cases of a ruptured pyometra presenting as pneumoperitoneum in the Japanese literature between 1977 and 1999. The most common cause of pneumoperitoneum is a perforation of the gastrointestinal tract. However, other possible causes, as seen in our patient, should also be taken into consideration. Although it is rare, a perforated pyometra should therefore also be considered when elderly women present with acute abdominal pain.

Aged↗

Microvilli and desmosomes of squamous cell carcinoma cells in tongue carcinoma related to regional lymph node metastasis: ultrastructural and immunohistochemical studies with transferrin receptor.

Squamous cell carcinomas of the tongue (n = 49), consisting of 21 cases with cervical lymph node metastasis and 28 nonmetastatic cases, were examined by electron microscopy with special emphasis on tumor cell attachment. No difference of tumor size (T classification) or pathological findings between the metastatic group and the nonmetastatic group was found. The metastatic cases had numerous microvilli and a small number of desmosomes regardless of the width of the intercellular spaces. The nonmetastatic cases had few microvilli in relatively wide intercellular spaces, or, in the cases in which numerous microvilli were present in the narrow intercellular spaces, the tumor cells were connected by a large number of desmosomes. Transferrin receptor, which is a marker of cell proliferation, was localized in the cell membrane by immunohistochemistry and especially in microvilli by immunoelectron microscopy. It is suggested that microvilli might be related to the proliferation and the metastasis of squamous cell carcinoma cells.

Adult↗

Investigation of titanium leak to bone tissue surrounding dental titanium implant: electron microscopic findings and analysis by electron diffraction.

This study investigated the tissue response associated with dental titanium implants. The mandibular third and fourth premolars and first molar of three adult beagle dogs were extracted bilaterally. Healing was then allowed for 3 months. Six titanium implants were placed in the mandibles of a dog. Three weeks after the implantation, mandibular sections containing the implants were retrieved with the use of a bone saw and investigated by light and electron microscopy, X-ray microanalyzer, and electron diffraction. Scanning electron microscopic observation showed titanium particles on the implant-bone interface, and investigation by microanalyzer revealed titanium not only on the implant-bone interface but also in the bone tissue. Transmission electron microscopic observation and investigation by electron diffraction showed titanium in the bone matrix and cells other than macrophages. In this study, titanium particles from the dental implant were recognized morphologically in the surrounding bone tissue. Thus, study of the influence of titanium particles on the human body is needed.

Animals↗

Elevation of serum interleukin-18 levels and activation of Kupffer cells in biliary atresia.

BACKGROUND/PURPOSE: Interleukin-18 (IL-18)/interferon-gamma-inducing factor (IGIF) is a novel proinflammatory cytokine that can induce interferon gamma (IFN-gamma). In addition, IL-18 enhances intracellular adhesion molecule-1 (ICAM-1) expression as well as Fas ligand (FasL) expression, and induces apoptosis in hepatic injury. The aim of this study was to clarify the potential role of IL-18 in the pathogenesis of the progressive inflammation and fibrosis in biliary atresia (BA). METHODS: Six children with BA before hepatic portoenterostomy (HPE), 13 with BA including 7 without jaundice and 6 with persistent jaundice after HPE, and 16 healthy controls were examined. Blood samples were obtained preoperatively from 6 patients, after HPE from 13, and after liver transplantation from 4. The IL-18 level was determined by an enzyme-linked immunosorbent assay (ELISA). Immunohistochemically, liver specimens from BA patients were studied using a monoclonal antibody to macrophage-associated antigen (CD68). RESULTS: IL-18 levels were elevated in the patients before HPE compared with those of the controls (349+/-54 pg/mL v. 138+/-13 pg/mL, P<.0001). After HPE, extremely high concentrations of IL-18 were observed in patients with persistent jaundice (532+/-95 pg/mL, P<.0001), and the IL-18 levels were significantly high even in the patients without jaundice (249+/-29 pg/mL, P<0.005). The high IL-18 level lasted for a long time even in the patients without jaundice after HPE. In contrast, the IL-18 levels immediately decreased after liver transplantation. Immunohistochemically, the number of CD68-positive Kupffer cells was significantly higher, and the size was larger in the livers of the patients than in the controls. The proliferation of CD68-positive cells was much more conspicuous in the liver specimens obtained during liver transplantation than in those at the time of HPE. CONCLUSIONS: Our findings showed elevation of serum IL-18 levels and activation of Kupffer cells in BA. IL-18 released from activated Kupffer cells might play an important role in the pathophysiology of the progressive inflammation and fibrosis in BA. Furthermore, IL-18 level may be related to the prognosis in patients with BA.

Antigens, CD↗