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Biomedical subjects

N Sato

Publications and source records attributed to N Sato.

At least 613 records · Page 34Linked to original sources
PubMed1997

Establishment of a primary culture of Echinococcus multilocularis germinal cells.

This study was designed to establish an in vitro primary culture of germinal cells of Echinococcus multilocularis, a parasite that causes alveolar echinococcosis of the liver (AEL). We also investigated the temperature-dependency of the cultured cells. The germinal cells, which originated from a human lesion, were cultured by an original fluid-suspension method at 25 degrees C or 37 degrees C for 4 weeks. Anchorage-dependent and -independent cells were observed by light microscopy, transmission electron microscopy, and immunocytochemistry to confirm their origin. Cell number and viability were examined by immunocytochemistry and mitochondrial exclusion test. The cultured cells were also inoculated into jirds (Meriones unguiculatus) to evaluate metacestode formation. Morphology and immunocytochemistry showed that the cultured cells were typically germinal cells. The cell number declined gradually over the 4-week culture period, but viability remained at 50% at 3 weeks. These findings were not associated with either of the two culture temperatures; moreover, host-associated cells were not noted in the cultured cells at 25 degrees C. The implanted cells formed metacestodes in the jird peritoneal cavity, and their histology demonstrated mature and typical alveolar-type echinococcal cysts. We successfully established an in vitro primary culture of germinal cells. This should contribute to future studies, and, hence, a better outcome for patients with AEL.

Animals↗
PubMed1997

Contribution of mass screening system to resectability of hepatic lesions involving Echinococcus multilocularis.

The prognosis for patients with alveolar echinococcosis of the liver (AEL) is excellent when the lesion is completely resected. Early detection of the disease and subsequent resection of the lesion are thus indispensable; however, the usefulness of screening systems is now controversial. This study was designed to compare screened and non-screened patients according to stage classification and to re-evaluate the effect of screening. We studied a total of 82 patients (63 screened and 19 non-screened). The stage classification showed a significant intergroup difference (P < 0.002). The largest tumors ranged from 30 to 100 mm, and there was a significant intergroup difference (P < 0.0014). Ultrasonography showed even small lesions in the screened patients. The complete resection rate was 74.6% for the screened patients, and 21.1% for the non-screened patients, showing a significant difference (P < 0.0001). The rate of unresectable lesions was higher in the non-screened patients (32%) than in the screened patients (11%), showing a significant difference (P < 0.04). The present screening system contributes to early detection and subsequent resection of AEL, leading to a better outcome.

Animals↗
PubMed1997

Multiple early esophageal cancers arising from Barrett's esophagus, and a review of cases of early adenocarcinoma in Barrett's esophagus in Japan.

A case of early esophageal adenocarcinoma arising in Barrett's esophagus is reported. Many cases of Barrett's esophagus, which is considered a premalignant condition, have been reported in Western countries, but few cases have been reported in Japan. The patient, a 53-year-old man with nausea and vomiting, was a drinker (four glasses wine/day for about 30 years), but did not smoke. He had had a hiatal hernia of the esophagus. Since endoscopic biopsies demonstrated an early adenocarcinoma in Barrett's esophagus, subtotal esophagectomy was performed. In the resected esophageal material, Barrett's esophagus was seen to extend for 12 cm. In addition to the cancer detected preoperatively as a 0-IIc lesion (1.5 cm in diameter), a 0-IIb lesion (1.5 cm in diameter) was also detected in the postoperative survey. Both lesions were well differentiated adenocarcinoma that had invaded only into the lamina propria mucosa. The 23 cases of early adenocarcinoma in Barrett's esophagus that have been reported in Japan were reviewed, and it was learned that the present case is the second of multiple early cancer arising in Barrett's esophagus so far reported in Japan.

Adenocarcinoma↗
PubMed1997

Analysis of the cluster of ribosomal protein genes in the plastid genome of a unicellular red alga Cyanidioschyzon merolae: translocation of the str cluster as an early event in the rhodophyte-chromophyte lineage of plastid evolution.

The nucleotide sequence of a cluster of ribosomal protein genes in the plastid genome of a unicellular red alga, Cyanidioschyzon merolae, which has been supposed to be the most primitive alga, was determined. The phylogenetic tree inferred from the amino acid sequence of ribosomal proteins of two rhodophytes, a chromophyte, a glaucophyte, two chlorophytes (land plants), a cyanobacterium, and three eubacteria suggested a close relationship between the cyanobacterium Synechocystis PCC6803 and the plastids of various species in the kingdom Plantae, which is consistent with the hypothesis of the endosymbiotic origin of plastids. In this tree, the two species of rhodophytes were grouped with the chromophyte, and the glaucophyte was grouped with the chlorophytes. Analysis of the organization of the genes encoding the ribosomal proteins suggested that the translocation of the str cluster occurred early in the lineage of rhodophytes and chromophytes after these groups had been separated from chlorophytes and glaucophytes.

Cyanobacteria↗
PubMed1997

Extradural spinal meningioma: MRI.

We report a case of extradural spinal meningioma with pathologically proven features of malignant transformation. The MRI findings of extradural spinal meningioma and differences in the findings from intradural meningiomas are discussed.

Adult↗
PubMed1997

Imaging diagnosis of alveolar echinococcosis in young patients.

We review the imaging findings in seven children with alveolar echinococcosis of the liver. Calcification was seen on plain abdominal films in five of seven patients (66.6 %); the calcifications were small or coarse with irregular margins. Ultrasound was performed in four cases, identifying the lesions in all four as small calcifications with or without cysts. Computed tomography (CT) was performed in four cases and showed small calcifications, calcifications surrounding a cyst, or an aggregate of calcifications. Angiography was performed in all seven patients and showed changes of intrahepatic arterial stretching, overgrowth of small arteries, and a honeycomb pattern in the capillary phase. Venography revealed compression of the inferior vena cava in two patients. Serum screening together with ultrasonography and CT are useful for diagnostic imaging of alveolar echinococcosis.

Adolescent↗
PubMed1997

Intraperitoneal dissemination probably caused by needle biopsy of alveolar echinococcosis of the liver: experimental study.

Alveolar echinococcosis of the liver (AEL) is a parasitosis with a potential for malignant tumor-like behavior. The disease is diagnosed by a combination of serologic tests, diagnostic images, and the histology of needle biopsy specimens. It remains unresolved whether the biopsy induces subsequent troubles. We designed this study to investigate critical problems after needle biopsy of AEL lesions using an experimental model. Five samples were prepared from the resected lesions of AEL patients: (A) 10% suspension of trypsin digests of the minced lesion; (B) 10% suspension of mesh-filtered sediment of the minced lesion; (C) 10% sediment suspension after washing the nonminced lesion; (D) supernatant after centrifuging intracystic fluid; (E) 10% sediment suspension after centrifuging intracystic fluid. A 1-ml aliquot of each sample was injected intraperitoneally into jirds (gerbils) or cotton rats, respectively. The animals were sacrificed 12 weeks later, and intraperitoneal metacestodes were observed. All samples except D developed metacestodes, and their histologies were all lesions of typical alveolar echinococcosis. These results suggest that a needle biopsy may cause intraperitoneal dissemination or tracial implantation of the parasites along the track of the needle.

Animals↗
PubMed1997

Esophageal carcinosarcoma: a genetic analysis.

Carcinosarcoma of the esophagus is a rare malignant neoplasm that consists of both carcinomatous and sarcomatous elements. The histogenesis of the sarcomatous component is generally considered to result from metaplasia of carcinomatous cells toward mesenchymal differentiation. True carcinosarcoma, characterized as a collision between a carcinoma and a sarcoma, is extremely rare. We describe a patient with primary achalasia who developed a true carcinosarcoma of the esophagus in which clonal differences between carcinomatous and sarcomatous elements were genetically and immunohistochemically demonstrated. A polypoid tumor located in the middle third of the esophagus developed in a 51-year-old man with longstanding achalasia. The tumor was predominantly composed of spindle-shaped sarcomatous cells. Squamous cell carcinoma in situ and islands of well-differentiated squamous cell carcinoma in the sarcomatous element were histologically observed. The sarcomatous element was immunoreactive for both mesenchymal and myoid markers. The carcinomatous component expressed type I and type II cytokeratins as well as epithelial membrane antigen. Analysis for chromosomal loss of heterozygosity performed in multiple microdissected samples of each sarcomatous and carcinomatous element revealed distinct genetic clonalities. These differences in immunohistochemical and genetic clonalities suggest that the tumor composed of squamous cell carcinoma and leiomyosarcoma originated separately from epithelial and mesenchymal precursors.

Carcinosarcoma↗
PubMed1997

Efficacy and safety of preoperative percutaneous transhepatic portal embolization with absolute ethanol: a clinical study.

BACKGROUND: Preoperative portal embolization has been performed by using various thrombogenic substances to increase the safety and resectability of liver surgery. We evaluated the clinical safety and efficacy of using absolute ethanol in preoperative portal embolization. METHODS: Our study included 19 patients who had undergone right hepatic lobectomy. According to our criteria for right lobectomy of the liver, seven patients were not appropriate for the operation because of a high risk in each of postoperative liver failure. Those patients received preoperative right portal embolization with 11 to 32 ml absolute ethanol. The remaining 12 patients satisfied our criteria and received no preoperative embolization. RESULTS: Although alanine aminotransferase concentrations increased dramatically after the embolization, all serologic changes reverted within 3 weeks. The mean volume of the nonembolized lobe increased from 320 cm3 to 619 cm3 and 667 cm3 2 and 4 weeks, respectively, after embolization. The mean regeneration rate of this lobe was 21.3 cm3 per day for the first 2 weeks and 11.4 cm3 per day for the first 4 weeks after embolization. All patients underwent right lobectomy of the liver and survived; none of the patients had severe complications associated with embolization or surgery. The postoperative survival periods were not statistically significant between the patients with and without preoperative portal embolization. CONCLUSIONS: According to our criteria for liver surgery, the seven patients should not have undergone major surgery, but each underwent right lobectomy of the liver and all survived, showing that portal embolization with absolute ethanol brings about compensatory hepatic hypertrophy for major surgery and that its extreme effect on liver regeneration could widen the range of patients appropriate for liver surgery.

Adult↗
PubMed1997

Molecular and epidemiological studies of Werner syndrome in the Japanese population.

Werner syndrome (WS) is an autosomal recessive genetic disease characterized by many age-related features. The gene responsible for WS (WRN) has been isolated and contains a helicase domain, but its function is unknown. Six different mutations throughout the WRN gene have been reported in the Japanese population. We have studied whether patients with a specific mutation exhibit distinct phenotypes from others. Fourteen patients with different mutations showed almost the same signs and symptoms and, therefore, the C terminal part of the product appears to be crucial for its functions, although other parts may be important as well. Haplotype analyses using 13 microsatellites covering the 2.8-3.0 cM WRN region showed that two out of six different mutations had founder chromosomes. These two founder chromosomes may be evenly distributed throughout the western part of Japan, suggesting that these mutations go back to a time earlier than 1400 years ago.

Chromosome Mapping↗
PubMed1997

Presence of adrenomedullin-like immunoreactivity in the human cerebrospinal fluid.

The presence of adrenomedullin-like immunoreactivity in the cerebrospinal fluid was studied by radioimmunoassay in 13 subjects with various neurological diseases. The concentrations of adrenomedullin-like immunoreactivity in the cerebrospinal fluid were 9.4 +/- 3.1 pmol/l (mean +/- SD, n = 13). Reverse-phase high performance liquid chromatography of the extract of the pooled cerebrospinal fluid showed that approximately 40% of the adrenomedullin-like immunoreactivity was chromatographically identical to human adrenomedullin (1-52). This is the first report that demonstrates the presence of adrenomedullin-like immunoreactivity in the human cerebrospinal fluid.

Adrenomedullin↗
PubMed1997

Leptin stimulates insulin secretion and synthesis in HIT-T 15 cells.

Leptin, an ob gene product, corrects hyperinsulinemia in ob/ob mice. The leptin receptor may exist in pancreatic islets. The present studies were undertaken to determine the direct effect of 1-100 ng/ml recombinant leptin on insulin secretion and synthesis in HIT-T 15 cells by using static culture system. The addition of recombinant leptin significantly increased insulin secretion for 20 min at the highest concentration (100 ng/ml). The addition of recombinant leptin dose-dependently increased insulin secretion for 24 h in the 7 mM glucose-containing F-12 K medium. The incubation with recombinant leptin for 24 h increased preproinsulin mRNA expression, assessed with reverse transcription-polymerase chain reaction (RT-PCR) method. It was furthermore demonstrated that HIT-T 15 cells possessed the specific binding site for [125I]-labeled leptin. The present study demonstrated the existence of the leptin-specific binding sites that mediate its stimulatory effect on insulin secretion and synthesis in HIT-T 15 cells.

Actins↗
PubMed1997

Polymorphism of angiotensin converting enzyme, angiotensinogen, and apolipoprotein E genes in a Japanese population with cerebrovascular disease.

The homozygous deletion allele of the angiotensin converting enzyme gene (ACE/DD), homozygous threonine allele of the angiotensinogen gene (AGN/TT), and the epsilon4 allele of the apolipoprotein E gene (apoE/epsilon4) are reported to be associated with ischemic heart disease. Cerebrovascular disease (CVD) is another atherosclerotic disease; and the effects of these polymorphisms on CVD have been confusing. In this study, we investigated whether ACE/DD, AGN/TT, and apoE/epsilon4 genotypes are associated with CVD and whether genetic risk is enhanced by the effect of one upon another. We ascertained these genotypes in patients with cerebral infarction (n = 55) and cerebral hemorrhage (n = 38), diagnosed by brain computed tomography. Control subjects for the infarction group and the hemorrhage group were randomly selected from 583 subjects matched for age, gender, and history of hypertension with patients. Frequency of ACE/DD genotype was higher in the patients with infarction than in the controls (chi2 = 6.1, P < .05). The AGN/TT genotype was not associated with either infarction or hemorrhage, but it increased the relative risk for cerebral infarction in the subjects with ACE/DD genotype (chi2 = 8.0, P < .01, odds ratio; 11.7, 95% confidence intervals: 1.4 to 96.0). There was no significant association between apoE/epsilon4 and CVD. These results suggest that ACE/DD predicts cerebral infarction, but not cerebral hemorrhage, and that AGN/TT enhances the risk for cerebral infarction associated with ACE/DD.

Adult↗
PubMed1997

Serial changes in contribution of substrates to energy expenditure after transthoracic esophagectomy for cancer.

This study was designed to examine the metabolic response of patients following transthoracic esophagectomy for carcinoma of the esophagus during the administration of total parenteral nutrition. Thirty-five patients underwent a right thoracotomy and transthoracic esophagectomy with nodal dissection in the neck, mediastinum, and abdomen. The resting energy expenditure (REE) was measured preoperatively, and on the 1st, 3rd, 5th, and 7th postoperative days (PODs) using indirect calorimetry. The REE was significantly higher following transthoracic esophagectomy on PODs 1, 3, 5, and 7 than preoperatively. The caloric contribution of fat was significantly less on 3rd, 5th, and 7th PODs than on the 1st POD. In contrast, carbohydrate oxidation increased significantly on the 3rd, 5th, and 7th PODs compared to that of the 1st POD. These results may help optimize the nutritional support regimen for post-esophagectomy patients.

Adult↗
PubMed1997

Autologous bone marrow transplantation for patients with advanced chronic myelogenous leukemia.

We report on seven chronic myelogenous leukemia (CML) patients who received autologous bone marrow transplantation (ABMT) using bone marrow (BM) cells while at the chronic phase (CP) under the various treatments. Of the seven patients, four progressed to accelerated phase (AP) in 83-248 weeks after onset and three patients entered blastic crisis (BC) in 84-171 weeks after onset. All patients received high-dose chemoradiotherapy followed by infusion with 11.3 +/- 12.1 x 10(7) (average +/- S.D.) of bone marrow mononuclear cells (BM-MNCs)/kg IFN-alpha was resumed shortly after platelet recovery. Of the four patients in AP, one developed a recurrence of blastoma in 7 weeks, one progressed to second AP in 138 weeks after ABMT and two patients have survived the second CP for 159 and 330 weeks since ABMT, respectively. One of them achieved the complete disappearance of Ph1-positive metaphases for 33 weeks after ABMT. Of patients who received AMBT in BC, three relapsed within 8 weeks and died in 9, 17 and 58 weeks after ABMT, respectively. Hematological recovery was delayed in four patients. Therefore, we retrospectively re-evaluated the number of BM-MNCs collected through 50 procedures from 40 patients with CML-CP. The total MNCs obtained from 30 collections under IFN-alpha treatment was 27.4 +/- 30.9 x 10(8) cells (average +/- S.D.), being significantly lower than that obtained from 20 collections in pre-treatment state or with single chemotherapy other than IFN-alpha treatment (81.8 +/- 68.2 x 10(8) cells) (P < 0.005). The total number of MNCs correlated to white blood cell (WBC) count at BM collection (P < 0.01), which was also lower in the IFN-alpha(+) group than in the IFN-alpha(-) group (7.2 +/- 5.7 and 25.6 +/- 32.3 x 10(9)/l; P < 0.005). Our findings suggested that ABMT with the use of a sufficient number of progenitor cells might be helpful to CML patients in early AP and reach in extended periods of second CP. In addition, we suggest that BM collection is required before the start of IFN-alpha therapy because the total number of BM-MNCs correlated to the WBC count, which might be lower in IFN-alpha treatment.

Adolescent↗
PubMed1997

Intravenous avidin chase improved localization of radiolabeled streptavidin in intraperitoneal xenograft pretargeted with biotinylated antibody.

In the present study, we examined the effect of avidin administered intravenously (i.v.) on the biodistribution of radiolabeled streptavidin in mice bearing intraperitoneal (IP) xenografts pretargeted with biotinylated antibody. Tumors were established in nude mice by IP inoculation of LS180 human colon cancer cells. Monoclonal antibody MLS128, which recognizes Tn antigen on mucin, was biotinylated and injected IP into the IP tumor-bearing mice. Radioiodinated streptavidin was administered IP or i.v. 48 h after pretargeting of biotinylated antibody. Avidin was administered i.v. 30 min prior to streptavidin injection. The localization of radioiodinated streptavidin in the tumor pretargeted with biotinylated antibody was significantly higher than that without pretargeting and that of radioiodinated MLS128 by the one-step method. Avidin administration significantly accelerated the clearance of radioiodinated streptavidin in blood and other normal tissues and increased the tumor-to-blood radioactivity ratio regardless of administration route of streptavidin. The i.v. avidin chase improved tumor localization of radiolabeled streptavidin in the IP xenografts pretargeted with biotinylated antibody.

Animals↗