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Biomedical subjects

T Yagi

Publications and source records attributed to T Yagi.

At least 397 records · Page 22Linked to original sources
PubMed1994

Dyskeratosis congenita showing usual interstitial pneumonia.

A 46-year-old man was admitted to our hospital with cough and dyspnea on exertion. A chest X-ray film showed diffuse interstitial shadows. He had hyperpigmentation forming a network pattern around his neck and dystrophy of the fingernails and toenails, and was diagnosed as having dyskeratosis congenita. Histological examination of the lung specimen obtained from the left S4b by open lung biopsy revealed usual interstitial pneumonia pattern with neither asbestos bodies nor silicotic nodules. Taken together with previously published findings, pulmonary involvement is considered to be an important complication of dyskeratosis congenita.

Age Factors↗
PubMed1994

Weekly low-dose methotrexate therapy for sarcoidosis.

Low-dose methotrexate therapy has been used to treat a variety of chronic inflammatory diseases; a few studies have discussed the efficacy of this therapy for sarcoidosis. We present a patient with symptomatic sarcoidosis who was successfully treated with low-dose methotrexate after being refractory to steroids. This patient showed significant clinical improvement without development of any severe side effects. These findings suggest that low-dose methotrexate therapy may be a useful alternative treatment for sarcoidosis.

Adult↗
PubMed1994

Gastric adenocarcinoma in a cougar (Felis concolor).

Diffusely invasive tumors occurred in the stomach of a 9-year-old female cougar (Felis concolor) from a zoo in Japan. The tumors consisted of tubular adenocarcinoma cells, and had infiltrative growth to the submucosa and muscularis propria. Tumor cells were positive for carcinoembryonic antigen (CEA), lysozyme, epithelial membrane antigen (EMA), gastrin, alpha-1-fetoprotein (AFP), keratin, and B72.3. Mucin-like materials occurred within cytoplasmic vacuoles.

Adenocarcinoma↗
PubMed1994

[A case of so-called benign metastasizing leiomyoma].

A 44-year-old female was admitted to our hospital for the purpose of undergoing hysterectomy for removal of multiple uterine tumors. A chest X-ray film obtained on admission revealed a solitary nodule in the right lung field. The resected specimen containing the uterine tumors revealed well differentiated leiomyoma with no nuclear atypia or mitotic figures. The resected specimen from the pulmonary tumor revealed histologic findings similar to those of the uterine myomas, being devoid of any signs of mitosis. Similar cases have been reported as so-called benign metastasizing leiomyoma, and are generally regarded as low grade malignancy or leiomyomatosis. However, we consider this case to have had a primary pulmonary leiomyoma associated with uterine myoma since the pulmonary lesion was solitary and no mitotic figures were detectable. As the concept of metastasizing leiomyoma is confusing, the accumulation of additional case reports is necessary.

Adult↗
PubMed1994

Hepatectomy with extracorporeal circulation for liver metastasis from colon carcinoma located at the confluence of the major hepatic vein: a case report.

Liver metastasis located at the confluence of the major hepatic veins developed after an operation for sigmoid colon carcinoma in a 63-year-old patient. Curative resection of the tumor was performed by in situ hypothermic perfusion of the liver and extracorporeal circulation. Intra-abdominal bleeding occurred on the first postoperative day, and ligation of the right inferior phrenic artery was performed via an emergency laparotomy. Only mild elevation of ALT and recovery of the arterial ketone body ratio to the "safety zone" was noted on the second postoperative day. Hepatic function gradually deteriorated after the 4th postoperative day with no distinct cause. Diffuse fatty liver was suspected as a cause of liver failure. The patient died on the 31st postoperative day. The problems encountered in this case are discussed in this paper.

Adenocarcinoma↗
PubMed1994

Fyn expression during early neurogenesis in mouse embryos.

Fyn is a member of the Src family of tyrosine kinases which are thought to play important roles in cell to cell interactions during morphogenesis. The developmental profile of Fyn expression was examined using mutant mice in which lacZ gene was introduced into this locus. The expression was characteristic in the neural system. Though at low levels, it was detected in the headfold at embryonic day (E) 7.5 and in the luminal surface of neuroectoderm along the entire neural groove at E8.5. The expression appeared regional in rhombomeres at E8.5 and E9.5. Consistent expression was also found at a low level in the notochord. The expression was high in later stages of the neural tube which consists of three layers; it was in the marginal layer but not in the germinal layer. High expression was also found in developing dorsal root filaments of neural crest origin. Non-expression in dividing neuroepithelial cells and expression in developing neural fibers appeared ubiquitous features of Fyn expression throughout the entire brain.

Animals↗
PubMed1994

[A case of pulmonary eosinophilic granuloma confirmed by transbronchial lung biopsy].

A case of pulmonary eosinophilic granuloma confirmed by transbronchial lung biopsy (TBLB) is reported. A 63-year-old man was admitted to our hospital complaining of productive cough and exertional dyspnea. Chest roentgenogram and computed tomography showed bilateral linear and reticular shadows predominantly in the upper and middle lung fields. TBLB was performed and the specimens showed granulomatous lesions consisting of histiocytes with infiltration of eosinophils. Histiocytes were positive for S-100 protein by immunohistochemistry. He was diagnosed as having pulmonary eosinophilic granuloma. In the diagnosis of pulmonary eosinophilic granuloma, open lung biopsy is useful, but TBLB is also useful for diagnosis in the active or early stage of this disease.

Biopsy↗
PubMed1994

Tibial torsion in patients with medial-type osteoarthrotic knees.

Computed tomography (CT) measurements of torsion of the lower extremities were evaluated in 85 knees of 68 patients with medial-type osteoarthrotic knees and in 24 normal knees of 13 adults. In addition, segmental tibial torsion and CT density of the third lumbar vertebra, reflecting general osteoporosis, were measured. Although there were no differences in the degrees of femoral torsion or knee joint rotation, external tibial torsion in the 68 patients was observed to have a mean value of 11.3 degrees, significantly smaller than the 23.5 degrees observed in the 13 normal adults (p < 0.01). Lateral torsion was 14.1 degrees in mild, 11.9 degrees in moderate, and 7.5 degrees in severe stages of osteoarthrosis. The rate of decrease in lateral tibial torsion was 59.6% in the proximal tibia, 4.2% in the tibial shaft, and 36.2% in the distal tibia. The decrease of lateral tibial torsion was correlated with decrease of CT density of the third lumbar vertebra. There is a correlation between reduction of lateral torsion with the radiographic stage of osteoarthrosis of the knee and general osteoporosity.

Bone Density↗
PubMed1994

[Fluticasone propionate reduced the production of GM-CSF, IL-6 and IL-8 generated from cultured nasal epithelial cells].

Accumulation of mast cells and eosinophils in the nasal epithelial layer occurs in nasal allergic reactions and nasal polyps. We have already demonstrated that fluticasone propionate (FP) inhibits the accumulation of mast cells and eosinophils locally, and also improves the nasal symptoms of patients with allergic rhinitis. We hypothesized that cytokines generated from nasal epithelial cells possibly contribute to the accumulation of cells and eosinophils in the nasal epithelial layer. In this experiment we examined the inhibitory effect of FP on the production of GM-CSF, IL-6 and IL-8 by culturing of nasal epithelial cells in vitro. Our results show that FP significantly reduces the level of GM-CSF, IL-6 and IL-8 in the supernatant of culture media of nasal epithelial cells for a period of 6 days. In addition, preincubation of nasal epithelial cells with FP for 6 days causes a significant reduction of GM-CSF levels in the supernatant of culture-media of cultured nasal epithelial cells during the subsequent period of 6 days without FP. These results provide evidence that FP inhibits the accumulation of mast cells and eosinophils in the mucoepithelial layer of the nasal membrane.

Administration, Topical↗
PubMed1994

Non-receptor tyrosine kinases in mammalian neurogenesis.

Several members of the Src family of non-receptor tyrosine kinases are expressed at high levels in embryonic neural tissues as well as in adult brain. Relatively little has been known, however, about their roles in neural development. Attempts to clarify this by production of mutant mice have been unsuccessful because of gene redundancy. We earlier isolated a new cytoplasmic protein tyrosine kinase, Csk, and showed that it inactivates uniquely all members of non-receptor tyrosine kinases in vitro. Here, we have generated Csk-deficient mouse embryos and shown that Csk is indeed an indispensable negative regulator for all non-receptor tyrosine kinases in vivo, and that regulated activity of these kinases is essential for normal development of mice at the neural stage. The signaling pathway through Src-family kinases during neurulation is also discussed.

Amino Acid Sequence↗
PubMed1993

Ultraviolet-specific mutations in p53 gene in skin tumors in xeroderma pigmentosum patients.

Mutations in the p53 gene were identified in five of eight non-melanoma skin tumors in the sun-exposed areas of xeroderma pigmentosum patients by the polymerase chain reaction and single strand conformation polymorphism analysis followed by sequencing of the DNA. All mutations occurred at the dipyrimidine sites, indicating that they were caused by UV irradiation. Two tumors had multiple mutations, and four tumors had nonsense mutations. Since xeroderma pigmentosum patients are extremely sensitive to UV, the solar UV should have caused the mutations in the p53 gene and the mutations must have played a significant role in UV tumorigenesis.

Adolescent↗
PubMed1993

Constitutive activation of Src family kinases in mouse embryos that lack Csk.

Csk is a novel cytoplasmic protein-tyrosine kinase that has been shown to inactivate members of the Src family of protein-tyrosine kinases in vitro. To examine the function of Csk in vivo, Csk-deficient mouse embryos were generated by gene targeting in embryonic stem cells. These embryos were developmentally arrested at the 10 to 12 somite stage and exhibited growth retardation and necrosis in the neural tissues. The kinase activity of p60c-src, p59fyn, and p53/56lyn in these embryos was greatly enhanced as an apparent consequence of enhanced specific activity. The increase in kinase activity was associated with an increase in tyrosine phosphorylation of several proteins, especially those around 85 and 120 kd. Thus, these results suggest that Csk indeed acts as an indispensable negative regulator of Src family kinases in vivo.

Animals↗
PubMed1993

DNA sequencing of the seven remaining structural genes of the gene cluster encoding the energy-transducing NADH-quinone oxidoreductase of Paracoccus denitrificans.

In our previous papers, seven structural genes (NQO1-7) of the energy-transducing NADH-quinone (Q) oxidoreductase of Paracoccus denitrificans were characterized [Xu, X., Matsuno-Yagi, A., & Yagi, T. (1991a) Biochemistry 30, 8678-8684; (1991b) Biochemistry 30, 6422-6428; (1992a) Biochemistry 31, 6925-6932; (1992b) Arch. Biochem. Biophys. 296, 40-48]. This paper reports the identification, cloning, and sequencing of seven additional structural genes in the same gene cluster (P. denitrificans enzyme complex). These seven genes, designated NQO8-14, are composed of 1038, 492, 603, 306, 2112, 1542, and 1500 base pairs, respectively. The polypeptides encoded by the NQO8-14 genes are homologous, respectively, to the ND1 product, the 23-kDa polypeptide, and the ND6, ND4L, ND5, ND4, and ND2 products of the bovine NADH-Q oxidoreductase. The order of the 14 structural genes of the Paracoccus energy-transducing NADH-Q oxidoreductase in the gene cluster is NQ07, NQO6, NQO5, NQO2, NQO1, NQO3, NQO8, NQO9, NQO10, NQO11, NQO12, NQO13, and NQO14. Downstream from the NQO14 gene an open reading frame (designated URF240) was detected which encodes a predicted polypeptide homologous to the biotin [acetyl-CoA-carboxylase] ligase of Escherichia coli. In addition, a putative terminal sequence motif was observed downstream of the NQO14 gene, suggesting that the structural gene NQO14 is the 3'-terminal gene of the Paracoccus NADH-Q oxidoreductase gene cluster. Nucleotide sequencing of the entire gene cluster revealed the presence of three unidentified reading frames: one between the NQO3 and NQO8 genes and other two between the NQO9 and NQO10 genes. These are designated URF4, URF5, and URF6 and are composed of 768, 393, and 405 base pairs, respectively. The possible functions of the putative proteins encoded by URF5 and URF6 are discussed.

Amino Acid Sequence↗
PubMed1993

Right-handed rotation of an actin filament in an in vitro motile system.

Muscle contraction occurs by mutual sliding between thick (myosin) and thin (actin) filaments. But the physical and chemical properties of the sliding force are not clear; even the precise direction of sliding force generated at each cross-bridge is not known. We report here the use of a recently developed in vitro motile assay system to show supercoiling of an actin filament in which the front part of the filament was fixed to a glass surface through cross-linked heavy-meromyosin and the rear part was able to slide on a track of heavy-meromyosin. A left-handed single turn of superhelix formed just before supercoiling, suggesting that the sliding force has a right-handed torque component that induces the right-handed rotation of an actin filament around its long axis. The presence of the torque component in the sliding force will explain several properties of the contractile system of muscle.

Actins↗