Biomedical subjects

T Yagi

Publications and source records attributed to T Yagi.

785 records · Page 44Linked to original sources

PubMedDate not supplied

Local pulsatile intramyocardial pressure (IMP) as a vector force: simultaneous measurements of IMP and tissue oxygen availability.

A directional nonuniformity of the intramyocardial pressure (IMP) was observed in anesthetized open-chest dogs using a piezoelectric pressure sensor implanted in the left ventricular myocardium. The nonuniformity seemed to be attributable to the variation in myocardial fiber orientation. The IMP, which developed in a direction parallel to the base-apex line, was measured in the deep portion of the myocardium, simultaneously with local O2 availability. In some cases, IMP decreased quickly as soon as a decrement in O2 availability had proceeded only slightly as a result of ligation of the anterior descending artery (LAD). In other cases, the once decreased IMP recovered gradually even when O2 availability remained lowered by continuation of the ligation. These observations indicated that IMP had no direct dependency on O2 availability in the case of acute LAD.

Animals↗

PubMedDate not supplied

A case of colon cancer recurrence with P-glycoprotein treated by methotrexate, fluorouracil, and leucovorin.

A 68 year-old female underwent right hemicolectomy for an advanced cecum cancer and had been well without any evidence of recurrence for a year after surgery. Despite post-operative treatment with oral Tegafur (400 mg/m2/day), CEA level increased gradually beginning 15 months after surgery. Sequential chemotherapy with methotrexate (MTX) and 5-Fluorouracil (5-FU), followed by leucovorin rescue (MFL) was started on an outpatient basis, and has been continued every 4 weeks since then. It consisted of MTX (100 mg/m2) and 5-FU (600 mg/m2) started 24 hours after MTX, followed by oral leucovorin (15 mg/body) started 30 hours after MTX 6 times at intervals of 6 hours. CEA level declined initially, but increased slowly for 3 years on MFL, although no evidence of recurrence was detected by imaging studies with computed tomography, ultrasound, and scintigram. Four years after surgery, a tumor recurrence developed in the abdominal wall. The patient underwent resection of the tumor, resulting in a decline of the CEA level. She has been alive and well for 5 years on MFL after the primary surgery. Both the original tumor and recurrent tumor showed immunoreactivity for P-glycoprotein. The present case demonstrates the feasibility of using MFL on an outpatient basis, and its potential to suppress the colon cancer growth with P-glycoprotein expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMedDate not supplied

Mouse embryonic stem (ES) cell lines established from neuronal cell-derived cloned blastocysts.

We have established mouse embryonic stem (ES) cell lines from blastocysts derived by transfer of nuclei of fetal neuronal cells. These neuronal cell-derived embryonic cell lines had properties that characterize them as ES cells, including typical cell markers and alkaline phosphatase activity. Moreover, the cells had a normal karyotype and were pluripotent, as they were capable of differentiating into all three germ layers. Although they were derived from neuronal donor nuclei, the cells no longer expressed neuronal markers; however, they were capable of differentiating into cells with neuronal characteristics. These results suggest that the clone-derived cells have fully acquired an ES cell character. Thus, ES cells can be derived from embryos resulting from nuclear transfer, which results in reprogramming of the genetic information and acquisition of pluripotency. ES cells established from somatic cell-derived blastocysts could be useful not only as research tools for studying reprogramming but also as models for cell-based transplantation therapy.

Alkaline Phosphatase↗

PubMedDate not supplied

Postsurgical sequential methotrexate/5-FU and leucovorin on outpatient basis for advanced colorectal carcinoma.

BACKGROUND/AIMS: The present study compared the effects of sequential methotrexate and 5-fluorouracil followed by leucovorin rescue (MFL), as an adjuvant chemotherapy versus a combination of UFT and mitomycin C (MMC), on patient survival and recurrence after surgery for colorectal carcinoma. METHODOLOGY: Between January 1990 and December 1997, a total of 55 patients with advanced colorectal cancer were treated postsurgically by adjuvant chemotherapy using MFL or UFT-MMC. Surgical treatment was performed according to standardized procedures for radical resection of colorectal cancer. The patients were divided into 2 groups after surgery. The MFL regimen consisted of MTX (100 mg/m2) and 5-FU (600 mg/m2) at hour 24, followed by leucovorin rescue. The UFT-MMC regimen consisted of MMC (12 mg/m2) intraoperatively and MMC (6 mg/m2) every other week after surgery for 2 months, and oral UFT (375 mg/m2/day), a combination of tegafur and uracil in a molar ratio of 1:4, was continued for 3 years or longer depending on the patients tolerance. RESULTS: The overall survival rates after surgery were significantly (P < 0.05) higher in the MFL than the UFT-MMC group. Recurrence rates were significantly lower in the MFL than the UFT-MMC group, especially for liver recurrence. Disease-free survival was significantly (P < 0.05) higher in the MFL than the UFT-MMC group. CONCLUSIONS: These results demonstrated the superiority of MFL therapy for improving postsurgical survival in patients with advanced colorectal cancer, in particular those patients with a high risk of recurrence following potential curative resection.

Aged↗

PubMedDate not supplied

Detection of single-stranded DNA (ssDNA) in the vestibule of guinea pigs after the application of cisplatinum (CDDP).

BACKGROUND: Cisplatinum (CDDP) has a toxic effect on the inner ear. CDDP reacts with DNA and leads to apoptotic cell death. In this study, the presence of single-stranded DNA (ssDNA) was examined immunohistochemically. MATERIALS AND METHODS: CDDP (10 mg/kg b.w.) was injected into the guinea pigs intra-peritoneally. Animals were sacrificed three days after the injection. The temporal bones were fixed via cardiac infusion. The tissues were embedded in paraffin and then used for immunohistochemical examination. RESULTS: That ssDNA was detected in the CDDP treated vestibule. The sensory epithelium, transitional area, dark cells and vestibular ganglion cells exhibited a positive immunoreactivity to ssDNA. CONCLUSIONS: DNA fragmentation is a characteristic feature of apoptosis. Fragmented DNA is detected as ssDNA. Our results indicate that CDDP involves the apoptosis in the inner ear and this is the cause of the ototoxicity of CDDP.

Animals↗

PubMedDate not supplied

Blood transfusion and postoperative plasma cytokine antagonist levels in colorectal cancer patients.

BACKGROUND/AIMS: Postoperative cytokine antagonist response affects various factors. However, excessive stress responses are deleterious as increased plasma concentration of cytokine antagonists may induce an impaired immune system. METHODOLOGY: We determined plasma levels of cortisol, IL-1ra, and sTNF-R55 in 20 patients who had undergone resection of colorectal carcinoma. Ten patients had a blood transfusion during the operation (invasive group), but 10 patients had received no blood transfusion (less invasive group). Plasma levels of cytokine antagonists were determined before operation (POD 0) and POD-1, -2 and -7. RESULTS: Postoperative plasma cortisol and sTNF-R55 levels were significantly elevated on POD-1 in the invasive group. Plasma IL-1ra levels were significantly increased on POD-1 in both the invasive and less invasive groups. CONCLUSIONS: The present study demonstrated that perioperative allogeneic blood transfusion can induce an excessive production of cortisol and sTNF-R55, and might be deleterious.

Adult↗

PubMedDate not supplied

Induction of apoptotic pathway in the vestibule of cisplatin (CDDP)-treated guinea pigs.

BACKGROUND: During the process of apoptosis, double-stranded DNA is broken into single-stranded DNA by the action of caspases and caspase-activated deoxyribonuclease. We immunohistochemically examined the apoptotic changes induced by cisplatin in the vestibule of guinea pigs. MATERIALS AND METHODS: Cisplatin (10 mg/kg b.w.) was intraperitoneally injected into guinea pigs and, 3 days after the injection, the animals were sacrificed by intracardiac perfusion of fixative. The temporal bones were then removed and immunohistochemically stained for caspase-activated deoxyribonuclease or caspase 3. RESULTS: Both caspase-activated deoxyribonuclease and caspase 3 were observed in the dark cell area, transitional area and the sensory epithelium. CONCLUSION: These findings suggest that apoptosis is involved in the vestibular dysfunction of the CDDP-treated patients.

Animals↗

PubMedDate not supplied

Transepiphyseal plate osteotomy for severe tibia vara in children: follow-up study of four cases.

Transepiphyseal plate osteotomy of the medial tibial condyle was performed in three children (four knees) with severe progressive tibia vara and excessive ligamentous laxity. Two knees with Blount disease underwent tibial valgus osteotomy and epiphysiodesis associated with transepiphyseal plate osteotomy, and two knees with pseudoachondroplasia underwent tibial valgus osteotomy. Follow-up study at the time of skeletal maturity revealed satisfactory alignment of the leg, favorable congruity of the joint, and good ligamentous stability in all cases. Our experience indicates that the present procedures are excellent, although there are very few documented cases and almost no description of the postoperative clinical courses.

Achondroplasia↗

PubMedDate not supplied

An in vitro method for testing the sensitivities to drugs of human osteosarcomas grafted onto nude mice.

Sensitivities to anticancer drugs were tested with cultured cells from six osteosarcomas transplanted onto nude mice and those of six human osteosarcomas cultured in vitro directly from the original tumor. The suppression by the anticancer drugs of 3H-TdR incorporation into the cultured cells was examined. The cells that had been grafted onto nude mice were highly sensitive to ADM and MMC and less sensitive to BLM and MTX in all of the tumors tested. Similar results were obtained with cells cultured directly in vitro from the original tumor. These results were somewhat comparable with those achieved by measuring cell survival and the success of back transplants onto nude mice after treatment with drugs. If further information on appropriate labeled precursors can be developed, testing the sensitivity of tumors to drugs by measuring the suppression of nucleic acid synthesis should prove useful in clinical applications.

Animals↗

PubMedDate not supplied

Small cell carcinoma of the stomach: a case report.

A case of a gastric small cell carcinoma discovered incidentally by screening ultrasonography is presented. Ultrasonography demonstrated a subcardial metastatic lymph node and multiple hepatic metastatic lesions. Upper GI series and gastroendoscopy revealed a large ulcerated tumor in the cardia of the stomach, and a Borrmann type II tumor, 4 x 2.5 cm, was found in the resected stomach. We describe the radiological findings of the upper GI series, ultrasonography, CT, and gastroendoscopy, and review the literature.

Aged↗

PubMedDate not supplied

Advanced endocrine cell carcinoma of the gallbladder: a patient with 12-year survival.

Gallbladder carcinoid is a rare disease. In previous reports, classical carcinoid, an entity with a good prognosis, has not been distinguished from endocrine cell carcinoma, a tumor associated with marked cell atypia and mitosis, and a poor prognosis. The patient was a 66 year old woman who presented to our hospital with a chief complaint of jaundice. Pre-operatively, she was diagnosed as having advanced gallbladder carcinoma invading the liver and the hepatic hilus. The patient underwent right hepatic trisegmentectomy with en bloc resection of the caudate lobe and extrahepatic bile ducts, extended lymph node clearance and left hepaticojejunostomy. Histopathological examination showed positive Grimelius staining, marked mitosis, and intense atypism, hence, the tumor was diagnosed as an endocrine cell carcinoma. Twelve years after surgery, the patient is healthy, without any sign of recurrence. We present this novel case of long-term survival and review the literature.

Aged↗