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Biomedical subjects

S Nakamura

Publications and source records attributed to S Nakamura.

At least 235 records · Page 13Linked to original sources
PubMed2001

Gastric carcinoma with psammomatous calcification after Billroth II reconstruction: case report and literature review.

A case of gastric carcinoma with psammomatous calcification arising in the remnant stomach after Billroth II reconstruction is reported. Borrmann type 1 gastric carcinoma was detected in the remnant stomach of an 82-year-old woman, who had a past history of distal partial gastrectomy for a perforated gastric ulcer, with Billroth II reconstruction at 40 years of age. Histologically, the tumor was a tubular adenocarcinoma that invaded the muscularis propria. Numerous psammoma bodies were found in the lumens of the tumor glands. Dystrophic calcification of gastric cancer is rare and psammomatous calcification of gastric cancer has only been reported in five cases previously. To our knowledge, this is the first case of gastric carcinoma with psammomatous calcification arising in the remnant stomach. We also review previously published reports regarding gastric carcinoma with psammomatous calcification.

Adenocarcinoma↗
PubMed2001

Morphological spectrum of cyclin D1-positive mantle cell lymphoma: study of 168 cases.

Immunostaining for cyclin D1 is essential for reliable diagnosis of mantle cell lymphoma (MCL). However, a small number of cyclin D1-positive lymphomas other than MCL have been encountered. Our goal was to investigate the morphological spectrum of MCL as a disease entity, based on cyclin D1 overexpression. We reviewed 181 biopsy specimens obtained from 168 cases of cyclin D1-positive MCL. Typical findings were the presence of nodular (53.9% of cases) or diffuse (46.1%) histological patterns, containing mantle zone patterns (16.8%), naked germinal centers (33.5%) and perivascular hyaline deposition (83.2%). Unusual findings of residual germinal centers with a mantle cuff (four cases) and follicular colonization (two cases) were seen. High magnification showed a monotonous proliferation of tumor cells with cytological diversity including small (3.0%), intermediate (43.1%), medium (34.1%), medium-large (13.2%) and large (6.6%) cells. Pleomorphic and blastic/blastoid variants were encountered in 9.6 and 7.2% of cases, respectively. Three cases had foci of cells of considerable size, with a moderately abundant pale cytoplasm resembling marginal zone B cells. Two cases showed an admixture of cells which appeared transformed and mimicked the histology of chronic lymphocytic leukemia/small lymphocytic leukemia. In one, neoplastic mantle zones were surrounded by sheets of mature plasma cells, resembling the plasma cell type of Castleman's disease. An admixture of areas characteristic of MCL and of other larger cells, indicating histological progression or a composite lymphoma, were observed in seven cases. In high-grade lesions of five cases, nuclear staining of cyclin D1 was rarely detected. In our experience, cyclin D1 expression was also found in nine lymphomas other than MCL (five plasma cell myelomas, three Hodgkin's disease and one anaplastic large cell lymphoma). The application of cyclin D1 staining prompted us to recognize the broad morphological spectrum of MCL. MCL can be diagnosed with the application of cyclin D1 immunostaining, if careful attention is given to architectural and cytological features.

Adult↗
PubMed2001

Evaluation of water and electrolyte transport of tubular epithelial cells under osmotic and hydraulic pressure for development of bioartificial tubules.

Our aim was to develop bioartificial tubules using tubular epithelial cells and artificial membranes and evaluate the function of water and electrolyte transport by various tubular epithelial cells. The cells were cultivated onto extracellular matrix (ProNectin F) coating polycarbonate membrane. Water transport from the apical to the basolateral site of cells was examined using a modified Ussing chamber module. Water transport under colloidal osmotic pressure on the apical site and hydraulic pressure on the basolateral site were higher in JTC-12, LLC-PK1 cells than in MDCK cells. Water transport under osmotic plus hydraulic pressure was highest in LLC-PK1 cells. We made bioartificial tubules using LLC-PK1 cells and polysulfone hollow fiber cartridges. Water and Na ion transport function was high, and BUN and creatinine passage was recognized in these bioartificial tubules. BUN and creatinine concentrations of reabsorption fluid in these bioartificial tubules were significantly lower than those concentrations of control media and of noncell attached polysulfone hollow fiber cartridges. Though LLC-PK1 cells were more preferable cells for the use of bioartificial tubules in terms of water and electrolyte transport, the passage of BUN and creatinine was not appropriate for clinical use. To select more preferable cells for bioartificial tubules which transport water and electrolytes and do not induce passage of uremic toxins is necessary.

Animals↗
PubMed2001

Localization of imidazolone in the peritoneum of capd patients: a factor for a loss of ultrafiltration.

The presence of dicarbonyl compounds, potent precursors of advanced glycation end products (AGEs), has been recognized in unused peritoneal dialysis (PD) fluids. Accumulation of AGEs has been implicated in the alteration of peritoneal membrane properties during continuous ambulatory peritoneal dialysis (CAPD) therapy. To determine whether imidazolone, an AGE specifically derived from 3-deoxyglucosone (3-DG), contributes to a decrease in ultrafiltration (UF) capacity of the peritoneal membrane in CAPD patients, we immunohistochemically evaluated the localization of imidazolone in peritoneal tissues from CAPD patients. Mesothelial thickening in the peritoneum was found in six of seven CAPD patients. Imidazolone distinctly accumulated in peritoneal tissues of CAPD patients, whereas it was hardly detected in those of patients with nonrenal disease. CAPD patients with a low UF capacity showed more extensive peritoneal deposition of imidazolone and more pronounced mesothelial thickening than those with a normal UF capacity. A CAPD patient with sclerosing peritonitis showed the most abundant localization of imidazolone among all CAPD patients. Gas chromatography/mass spectrometry showed that unused PD fluids contained high 3-DG concentrations (mean, 34.6 +/- 14.1 [SD] microgram/mL). In conclusion, the accumulation of imidazolone was noted in peritoneal tissues of CAPD patients, which preceded a decrease in UF capacity. Imidazolone modification may alter the quality of peritoneal membranes, presumably leading to a loss of UF and finally the development of sclerosing peritonitis.

Epithelium↗
PubMed2001

Visual demonstration of hepatitis C virus-specific memory CD8(+) T-cell expansion in patients with acute hepatitis C.

Hepatitis C virus (HCV)-specific CD8(+) T cells in peripheral blood mononuclear cells (PBMCs) from patients infected with HCV were quantitatively analyzed by flow cytometry using an HLA-B*3501-HCV epitope tetrameric complex. In chronic hepatitis C, tetramer(+)CD8(+) T cells were detected at frequencies ranging from 0.05% to 0.12% of total CD8(+) T cells. The number of tetramer(+)CD8(+) T cells in acute phase PBMCs from patients with acute hepatitis C was about 3 to 5 times higher than in recovery phase PBMCs from the same patients and in PBMCs from patients with chronic hepatitis C. Expanding tetramer(+)CD8(+) T cells in PBMCs from patients with acute hepatitis C express a CD28(+)CD45RA(-) memory T-cell phenotype. In contrast, tetramer(+)CD8(+) T cells in PBMCs from patients with chronic hepatitis C did not predominantly express this phenotype. These tetramer(+)CD8(+) T cells did not have perforin in their cytoplasma. The present study visually showed that a high number of circulating HCV-specific CD8(+) T cells in acute phase PBMCs from patients with acute hepatitis C are mostly memory T cells.

Acute Disease↗
PubMed2001

Postnatal growth of the rat palatine gland.

To elucidate how the palatine glands grow postnatally, the palatine glands of rats from 0 to 8 weeks of age were investigated histologically and immunohistochemically. Under light microscope, three dimensions of the right part of the palatine glands were measured and the total number of excretory ducts of the glands was counted from the parasagittal serial sections. Immunohistochemistry with anti-5-bromo-2'-deoxyuridine (BrdU) monoclonal antibody was also employed to detect the cellular proliferative activity. At birth (0 weeks), the palatine glands consisted of ducts and immature acini. The ducts in the glands were connected with excretory ducts. After 2 weeks, there was no duct in the glands. Most acinar cells became mature as mucous cells and took the form of tubulo-acini connected directly with excretory ducts. In the posterior region of the glands, serous acinar cells forming demilunes were occasionally seen. All three dimensions of the palatine glands became longer, and the number of excretory ducts tended to increase. Immunohistochemistry showed acinar and duct cells were highly proliferative in early stage of postnatal life and their proliferative activity decreased thereafter. This study demonstrated that immature rat palatine glands of newborn rats grow three-dimensionally during maturation, and that the parenchymal cell proliferation contributes to the growth of the rat palatine glands. In addition, it is suggested that the glandular tissue arises from the excretory ducts formed postnatally.

Animals↗
PubMed2001

Cap polyposis of the colon and rectum: an analysis of endoscopic findings.

BACKGROUND AND STUDY AIMS: Because of the rarity of cap polyposis of the colon and rectum, the endoscopic features of this condition have not been specified to date. The aim of this study is to characterize the endoscopic features of cap polyposis. PATIENTS AND METHODS: The diagnosis of cap polyposis was established by histologic findings in specimens obtained endoscopically or surgically from four patients. Colonoscopic findings in the four patients were retrospectively reviewed. RESULTS: The endoscopic features were divided into semipedunculated type (three patients) and flat-topped protruding type (one patient). In the semipedunculated type, the polyps were characterized by reddish protrusions of various configurations with eroded surface in the rectosigmoid colon. In the remaining patient, all the lesions were flat protrusions with a reddish central depression. The polyps of both types became smaller in size and fewer in number at the proximal part of the sigmoid colon. Multiple white specks were observed in the intervening mucosa in all four patients. CONCLUSIONS: The prominence of the polyps at the distal part of the colon and rectum and multiple white specks in the intervening mucosa seem to be the additional endoscopic features suggestive of cap polyposis.

Adult↗
PubMed2001

Endoscopic induction of mucosal fibrosis by argon plasma coagulation (APC) for esophageal varices: A prospective randomized trial of ligation plus APC vs. ligation alone.

BACKGROUND AND STUDY AIMS: Esophageal varices are treated by endoscopic ligation with or without sclerotherapy. Here we used argon plasma coagulation (APC) to promote mucosal fibrosis and compared the efficacy of ligation plus APC with ligation alone in the treatment of esophageal varices. PATIENTS AND METHODS: Our prospective study included 30 patients with esophageal varices randomly assigned to receive APC after ligation (combined group) and 30 patients assigned to receive ligation only (ligation group). Endoscopic ligation was performed until the varix shrank to F1 without red color sign or smaller. This was followed by induction of fibrosis of the distal esophageal mucosa using APC in the combined group. APC was performed using an argon gas at a flow rate of 1.5-2 l/min and a high frequency arc output of 50-60 W. Treatment outcome and complications were compared between the two groups. RESULTS: The mean follow-up time was 18.5+/-6.8 and 15.8+/-7.7 months (+/- SD) for the combined and ligation groups, respectively. The number of treatment sessions was slightly lower in the ligation group (2.9+/-0.6 vs. 2.5+/-0.6, P<0.05). The number of ligation bands used was not different between the two groups (13.4+/-3.1 vs. 14.9+/-2.4). The cumulative recurrence-free rate at 24 months after treatment in the combined group was significantly higher than in the ligation group (74.2% vs. 49.6%, P < 0.05). A significantly higher incidence of pyrexia was encountered in the combined group (P <0.05), but the incidences of other complications were similar in both groups. CONCLUSION: Our results indicate that endoscopic ligation of esophageal varices combined with APC is superior to ligation alone. Since APC is theoretically well suited for mucosal fibrosis therapy, it can be used for the complete elimination of esophageal varices and for fibrosis of the distal esophageal mucosa.

Argon↗
PubMed2001

Clinical significance of ST-segment elevation in lead V1 in patients with acute inferior wall Q-wave myocardial infarction.

BACKGROUND: This study was designed to determine the clinical significance of ST-segment elevation in the precordial leads (leads V1 and V2) in acute Q-wave inferior wall myocardial infarction. METHODS AND RESULTS: One hundred fifty-eight consecutive patients with acute Q-wave inferior wall myocardial infarction were classified into 3 groups on the basis of the initial ST-change in V1 (group 1 = 29 patients with ST elevation, group 2 = 97 patients with ST depression, and group 3 = 32 patients with no ST-segment change). The right coronary artery was the infarct-related artery in all the patients in group 1. Although there was no significant difference between groups 1 and 2, the number of left ventricular asynergic segments was larger and the incidence of major in-hospital arrhythmias was higher in groups 1 and 2 compared with group 3. Patients in group 1 had a significantly higher incidence of proximal lesion (86%) and right ventricular infarction (69%) than the other 2 groups did. When ST elevation in leads V1 and V2 was considered, 14 of 15 patients (93%) with ST elevation only in V1 had right ventricular infarction, whereas 6 of 14 patients (43%) with ST elevation in both V1 and V2 had right ventricular infarction (P =.011). CONCLUSIONS: ST-segment elevation in V1 on admission in patients with acute Q-wave inferior wall myocardial infarction indicates a right coronary artery lesion associated with a larger infarct size and a higher incidence of major in-hospital arrhythmias.

Adult↗
PubMed2001

Impact of repeat hepatectomy on recurrent colorectal liver metastases.

BACKGROUND: Hepatic recurrence is seen in approximately 40% of patients undergoing hepatectomy for colorectal metastases. This study was designed to assess the risks and clinical benefits of repeat hepatectomy for those patients. METHODS: Twenty-six patients underwent repeat hepatectomy for hepatic recurrence, and their clinical data were retrospectively reviewed for operative morbidity and mortality, performance level, and survival. RESULTS: There was no operative mortality after repeat hepatectomy. Operative bleeding was significantly increased in the second hepatectomy; but operating time, duration of hospital stay, and performance status after the second hepatectomy were comparable with those of the initial hepatectomy. The median survival time from the second hepatectomy was 31 months, and the 3- and 5-year survival rates were 62% and 32%, respectively. A short disease-free interval (6 months or less) between the initial hepatectomy and diagnosis of hepatic recurrence in the remnant liver was significantly associated with poor survival after the second hepatectomy. CONCLUSIONS: Repeat resection contributed to clinical benefits for selected patients with hepatic recurrence after the initial hepatectomy for colorectal liver metastases. However, appearance of hepatic recurrence within 6 months or less after the initial hepatectomy is a poor prognostic factor for repeat hepatectomy.

Adult↗
PubMed2001

Cytokine production and helper T cell subsets in Vogt-Koyanagi-Harada's disease.

PURPOSE: To investigate helper T (Th) cell subsets and cytokine production in patients with Vogt-Koyanagi-Harada's (VKH) disease. METHODS: Nine patients in the acute stage of VKH disease and 9 healthy controls were studied. Interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and IL-4 mRNA from peripheral blood mononuclear cells (PBMC) was detected by reverse transcriptase-polymerase chain reaction. Cytokine levels in plasma, cerebrospinal fluid (CSF) and PBMC culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). The proportions of each cytokine-producing CD4+ or CD8+ cells in PBMC cultured with or without anti-CD3 antibody stimulation were analyzed by flow cytometry. RESULTS: We observed a significant increase of cytokine mRNA positive cases of VKH patients in comparison with controls only in IFN-gamma mRNA detection from PBMC. ELISA detected IFN-gamma in CSF from only 1 patient and no cytokine in plasma. The levels of IFN-gamma and IL-2 were significantly higher in the stimulated cell culture supernatant of the patients than those of controls. The proportions of IFN-gamma- or IL-2-producing CD4+ cells were significantly higher in the patients than in controls in both stimulated and unstimulated conditions. However, no significant difference was found in IL-4-producing CD4+ cells. In CD8+ cells, significant difference was found only in IL-2-producing cells in the stimulated condition. CONCLUSIONS: Th cells from VKH patients produced predominantly Th1 cytokines, especially after stimulation in vitro. It is therefore suggested that activated Th cells produce predominantly Th1 cytokines, which then produce pathologic changes.

Adult↗
PubMed2001

Autoimmune disease-associated lymphadenopathy with histological appearance of T-zone dysplasia with hyperplastic follicles. A clinicopathological analysis of nine cases.

Autoimmune disease-associated lymphadenopathy shows marked histopathological and clinical diversity. We describe the clinicopathological and immunohistochemical findings of nine cases of autoimmune disease-associated lymphadenopathy, which posed a serious differential diagnostic problem regarding T-zone dysplasia with hyperplastic follicles. There were two males and seven females aged 25 to 65 years (median 37 years). The patients had multicentric lymphadenopathy in association with clinical and laboratory findings suggestive of an "autoimmune disease". Four patients were diagnosed to have systemic lupus erythematosus (SLE), and the remaining five patients had antiphospholipid antibody syndrome and Sjogren's syndrome (SS), rheumatoid arthritis (RA), chronic thyroiditis, RA and SS, and SLE and SS, respectively. None of the nine patients developed malignant lymphomas during the follow-up periods from 44 to 225 months (median 103 months). The lesions were characterized by paracortical hyperplasia with prominent vascular proliferation and many lymphoid follicles with germinal centers. The paracortical area usually contained numerous small T-lymphocytes without cytological atypia, accompanied by a variable number of plasma cells, B-immunoblasts, and histiocytes. Polymerase chain reaction analysis demonstrated no clonal rearrangement of the T-cell receptor chain gene in four cases examined, although immunoglobulin heavy chain rearrangement was detected in only one case. These findings suggest that autoimmune disease-associated lymphadenopathy, especially SLE, shares the histological features with T-zone dysplasia with hyperplastic follicles. The nine cases presented here should be differentiated from T-zone lymphoma with follicles and angioimmunoblastic lymphoma with hyperplastic germinal centers. To avoid overdiagnosis and overtreatment, we emphasize the need to turn attention to these clinical and laboratory findings as well as to the morphological features.

Adult↗