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M Muto

Publications and source records attributed to M Muto.

At least 91 records · Page 5Linked to original sources
PubMed1998

Isolation and characterization of apoptosis-resistant mutants from a radiosensitive mouse lymphoma cell line.

To analyze specific genes related to radiation-induced apoptosis, 12 apoptosis-resistant clones were isolated from cells of the radiosensitive mouse thymic lymphoma 3SB line after treatment with ethyl methanesulfonate. Five of 12 clonal cell lines were recloned and were examined for their susceptibility to X-ray-induced apoptosis. A cell survival assay showed that all five secondary cell lines were two to three times more resistant to X rays than 3SB cells. When 3SB cells were exposed to 5 Gy of X rays, the fraction of cells stained with erythrosin B increased quickly within 8 h of incubation after irradiation. However, no apoptosis occurred in these secondary mutant cells. In particular, the percentage of cells undergoing apoptosis in one clone, 1B1C4, was low even after incubation for 48 h. In contrast to X rays, after exposure to 20 J/m2 UV radiation, the proportion of apoptotic cells in these mutant cells increased and reached about 60 to 100% at 24 h, indicating a difference in the ability of X rays and UV radiation to induce apoptosis. A similar radioresistance was observed using agarose gel electrophoresis of DNA from cells of all X-irradiated secondary lines. Western blot analysis and a sequence-specific DNA-binding assay demonstrated that 1B1C4 cells had a functional defect in p53 protein, but the other four cell lines displayed wild-type p53 after X irradiation. Our results suggest the existence of separate radiation-specific p53-dependent and independent apoptosis in thymic lymphoma cells. Thus these apoptosis-resistant cell lines provide a useful tool to identify the genes involved in the signaling pathways leading to X-ray-specific apoptosis.

Animals↗
PubMed1998

[Correlation between functional and radiographic data, and broncho-alveolar cytology in patients with diffuse interstitial lung disease].

BACKGROUND: "Interstitial Lung Disease" is a term that includes a heterogeneous group of disorders characterized by variable degrees of parenchymal inflammation (alveolitis) and fibrosis. Alveolitis represents one of the most important aspects of ILD and its characterization by broncho-alveolar lavage (BAL) can give explanations of the different clinical features, in association with the evaluation of physiological changes and High Resolution Computed Tomography (HRCT). The aim of this study was to establish a correlation between variations in broncho-alveolar cells and anatomical-functional alterations in patients affected by ILD before and after corticoid therapy. METHODS: Thirty-one patients (14 males 17 females) were introduced in the study and were evaluated for clinical signs, functional parameters, HRCT and cyto-immunological aspects of BAL fluid. All data were acquired at the admission in the study, after 60 and 180 days. Patients had received prednisone 1 mg/kg/die for 60 days and, then, 0.25 mg/kg/die for 120 days. RESULTS: In lymphocyte alveolitis, a clinical-radiological improvement was frequently observed after therapy while in those with neutrophilic and eosinophilic components, no improvement was detected. CONCLUSIONS: In conclusion, BAL represents a useful tool in qualifying ILD which can be easily monitored by clinical, functional and radiological data. Therefore, a new method for the diagnosis and monitoring of ILD is suggested. This method has the marked advantage to reach a reliable diagnosis even in a high percentage of patients who refuse or can not undergo the biopsy assay.

Adult↗
PubMed1997

Nonsense mutation at Tyr-4046 in the DNA-dependent protein kinase catalytic subunit of severe combined immune deficiency mice.

The severe combined immune deficiency (SCID) mouse was reported as an animal model for human immune deficiency. Through the course of several studies, the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) gene came to be considered a candidate for the SCID-responsible gene. We isolated an ORF of the murine DNA-PKcs gene from SCID mice and their parent strain C.B-17 mice and determined the DNA sequences. The ORF of the murine DNA-PKcs gene contained 4128-aa residues and had 78.9% homology with the human DNA-PKcs gene. A particularly important finding is that a T to A transversion results in the substitution of termination codon in SCID mice for the Tyr-4046 in C.B-17 mice. No other mutation was detected in the ORF of the gene. The generality of this transversion was confirmed using four individual SCID and wild-type mice. The substitution took place in the phosphatidylinositol 3-kinase domain, and the mutated gene encodes the truncated products missing 83 residues of wild-type DNA-PKcs products. Furthermore, the quantity of DNA-PKcs transcript in wild-type and SCID cells was almost equal. These observations indicate that the DNA-PKcs gene is the SCID-responsible gene itself and that the detected mutation leads to the SCID aberration.

Amino Acid Sequence↗
PubMed1997

Syncope at sleep onset in a patient with nasopharyngeal carcinoma.

A patient with nasopharyngeal carcinoma developed atypical parapharyngeal-lesion syncope syndrome associated with stereotypical cycles of heart rate variation, which occurred only when he was drowsy before falling asleep. Vagal tone fluctuation is implicated.

Carcinoma, Squamous Cell↗
PubMed1997

Intraosseous pneumatocyst of the ilium: CT findings in two cases and literature review.

Intraosseous pneumatocyst of the ilium is a rare lesion of uncertain origin. It predilects male subjects and may be associated or not with sacroiliac joint degenerative disease, intra-articular gas, sacral pneumatocyst, and communication with the articular space. To our knowledge, only 16 observations have been reported in the literature. We have evaluated with plain radiographs and CT two additional cases. Plain films frequently identify these lesions, but CT is the method of choice in demonstrating their air density and assessing the possible abnormalities of the surrounding bone and sacroiliac joints.

Adult↗
PubMed1997

Association of apolipoprotein allele epsilon 2 with psoriasis vulgaris in Japanese population.

We studied phenotypic variations of apolipoprotein E (apoE) and the corresponding allele frequencies in 100 Japanese patients with psoriasis vulgaris (PV). The phenotypes of apoE were examined using analytical isoelectric focusing followed by immunoblotting with goat anti-apoE antibody and alkaline phosphatase-conjugated rabbit antigoat IgG. The phenotypic frequency of apoE3/2 in PV was significantly higher than in healthy controls, and this elevation was associated with an increased frequency of the epsilon 2 allele. Therefore, it is suggested that the apoE molecule plays an important role in the development of PV.

Adolescent↗
PubMed1997

Establishment and characterization of a novel human cell line exhibiting both immunophenotypic markers of monocyte/macrophage and natural killer cell lineages from peripheral blood of a patient with atopic dermatitis.

Large amounts of homogeneous cells are not always available for in vitro studies of inflammatory skin disorders. Here we demonstrate that a novel cell line, termed YAA, has been established from peripheral blood mononuclear cells, which were separated by the Ficoll method, of a patient with atopic dermatitis. YAA cells were grown in suspension culture. The cytochemical staining showed a positive reaction for alpha-naphthyl butyrate esterase, which was completely inhibited by sodium fluoride, but a negative result for periodic acid-Schiff, peroxidase and alkaline phosphatase. A large population of YAA cells exhibited phenotype of CD33 and CD56 but neither of CD2 nor CD3. The phorbol ester-stimulated YAA cells produced a considerable amount of tumor necrosis factor-alpha. These findings suggest that YAA might be a monocytoid line with an additional phenotype specific for natural killer cells.

Adult↗
PubMed1997

Ganglioside expression in melanomas from Japanese individuals: unusual pattern in two patients with metastatic lesions of acral lentiginous melanomas.

Melanoma among Japanese is rare, and differs in its clinical and histological characteristics from that found in Caucasians. In this study, the ganglioside expression of melanoma specimens obtained from Japanese was determined and compared with previously published data on Caucasians. The ganglioside composition of 25 biopsy melanoma specimens, including 13 primary and 12 metastatic lesions, was studied using thin layer chromatography. Four gangliosides (GM3, GD3, GM2, GD2) were most commonly expressed in melanomas in Japanese. The expression of gangliosides was quite variable in both primary and metastatic melanomas as seen in previous reports. No significant differences were observed between gangliosides from primary and metastatic sites. A new type of ganglioside expression, in which GM3 was nearly the only ganglioside (> 95%), was found in metastatic tumors from two Japanese patients with acral lentiginous melanoma (ALM), which is the most common clinical and histopathological type of melanoma among Japanese but is very unusual among Caucasians. The patterns of expression were similar to those in Caucasians except for the detection of a "new" pattern.

Adult↗
PubMed1997

Overexpression of p53 protein associated with proliferative activity as evaluated by Ki-67 immunostaining in well-differentiated squamous cell carcinoma of the skin.

BACKGROUND: Overexpression of p53 protein has been demonstrated in a variety of human malignant tumors, and its role in oncogenesis and tumor progression is thought to be important. Recently, some reports have suggested that p53 overexpression might be an indicator of immaturity or proliferative activity of cells in cutaneous lesions. OBJECTIVE: The aim of the present study was to clarify the relationship between overexpression of p53 protein and the proliferative activity evaluated by Ki-67 immunostaining in well-differentiated squamous cell carcinoma (SCC) of the skin. METHODS: Sixteen cases of well-differentiated SCC were analyzed by immunohistochemistry for the expression of p53 protein and Ki-67 antigen. RESULTS: p53 protein was detected in 12 out of the 16 cases (75%). The percentage of p53-protein-positive tumor cells (DO-7 index) ranged from 0 to 80.4 (mean +/- SD = 33.8 +/- 29.7) and the percentage of Ki-67-antigen-positive tumor cells (MIB-1 index) from 23.4 to 65.1 (mean +/- SD = 42.3 +/- 15.8). Cases with higher DO-7 indices tended to show higher MIB-1 indices and the correlation was statistically significant. CONCLUSION: Overexpression of the p53 protein seems to be a useful indicator of proliferative activity in cutaneous SCC.

Carcinoma, Squamous Cell↗
PubMed1997

Congenitally acquired herpes zoster infection in a newborn.

We report a case of congenitally acquired herpes zoster infection in a newborn whose mother suffered from varicella in her eighth month of pregnancy. The newborn had vesicles with limited distribution on the left C7 region. Herpes zoster infection was clinically suspected and confirmed by the Tzanck test and a high titer of anti-varicella-zoster-virus immunoglobulin M (x1,280).

Antibodies, Viral↗
PubMed1997

Relationship between degree of mitral protrusion assessed by use of B-mode echocardiography and degree of mitral regurgitation using an experimental model in dogs.

We studied the relationship between the degree of mitral protrusion and degree of mitral regurgitation in an experimental model in which the degree of mitral protrusion could be adjusted. The model was developed by dissecting the dorsal papillary muscle through a left atriotomy in 5 dogs and re-attaching the papillary muscle to the original site using a single mattress suture threading through the epicardium under cardiopulmonary bypass. By manipulating the suture from a position outside the epicardium, the degree of mitral protrusion could be adjusted. The long-axis view of the mitral valve was imaged by B-mode echocardiography with the transducer placed directly over the surface of the right ventricular outflow tract. The height (H) from the coaptation point or tip of the protruded cusp in relation to the mitral annular plane was measured as an index of mitral protrusion. Mitral regurgitation as a result of the mitral protrusion decreased the left ventricular systolic pressure, and increased the heart rate, mean left atrial pressure (LAPm), and ratio of left ventricular end-diastolic dimension to body weight (LVEDD/BW). H was negatively correlated to LAPm and LVEDD/BW (r = -0.723 and -0.697, respectively). Our results indicated that H expresses not only the degree of mitral protrusion but also the degree of mitral regurgitation, and were in agreement with the previous findings obtained on dogs with spontaneous mitral regurgitation.

Animals↗
PubMed1997

Prevalence, vasculature, and innervation of myocardial bridges in dogs.

OBJECTIVE: To report gross anatomic examination of the canine myocardial bridge (MB), a muscular band found above the coronary artery (CA), with respect to its occurrence, location, vascularization, and innervation. SAMPLE POPULATION: 629 canine hearts obtained within 1 to 3 hours after euthanasia. PROCEDURE: After an incision was made at the left fifth intercostal space, the pericardial sac was cut open, and if an MB was present, the heart, lungs, and annexed structures were removed together and subsequently subjected to macroscopic examination of MB musculature and innervation after formalin fixation. Vascular casting was performed by use of methyl methacrylate perfusion. RESULTS: Of the 629 canine hearts examined, 189 (30%) had MB, occurrence of which was independent of sex, age, and breed. Among 13 MB-containing specimens examined in detail, there was great variation in thickness (0.11 to 2.24 mm; mean, 0.45 mm) of MB and distance (24 to 236 microns; mean, 103 microns) between the MB and the paraconal interventricular branch of the left CA (PIBL). One pair or 2 pairs of blood vessels from the PIBL supplied the MB muscle. Venous blood returned to the coronary circulation via the branches of the great coronary vein coursing on both sides of the PIBL, in close contact with the PIBL and the groove wall. The 2 veins rejoined at the upper portion of the PIBL and passed obliquely to the coronary groove under the left auricle, and finally drained the blood through the coronary sinus into the right ventricle. Innervation to the MB muscle was derived from nerve branches of the middle cervical ganglion and left vagus nerve. CONCLUSION: Prevalence and localization of MB in dogs and human beings are similar. Vascularization of the MB muscle originates from the PIBL. The cervical ganglion and vagus nerve control the MB muscle.

Age Factors↗
PubMed1996

Countercurrent chromatographic analysis of ovalbumin obtained from various sources using the cross-axis coil planet centrifuge.

The present studies have been conducted to investigate the cause of an unusually broad peak of ovalbumin obtained by countercurrent chromatography (CCC) reported earlier [K. Shinomija et al., J. Chromatogr., 644 (1993) 215]. A series of CCC experiments using our prototyte of the cross-axis coil planet centrifuge revealed that commercial ovalbumin products were classified into two groups: group A formed two peaks of ovalbumin at pH 7.0 and 5.8, while group B showed a relatively sharp single peak in a broad range of pH. Electrophoresis indicated that the group A ovalbumin consisted of both natural and denatured products: the natural ovalbumin is a monomer (Mr 45 000) whereas the denatured products form dimers (Mr 90 000). The abnormally broad peak obtained from the group A ovalbumin at pH 9 is apparently caused by the heterogeneity of the sample protein.

Animals↗
PubMed1996

Establishment and characterization of a novel human promonocytic cell line from peripheral blood of a patient with psoriasis.

Human monocyte/macrophage lineages have unique phagocytic and immune-regulatory functions. We established a promonocytic cell line from the peripheral blood of a patient with psoriasis vulgaris. The newly established cells, termed YAP cells, grew in a suspension culture. In Wright-Giemsa-stained preparations, YAP cells were round or polygonal in shape. Transmission electron microscopy showed that the cells had clear nuclei with well-defined nucleoli. There were frequent mitochondria, a relatively abundant endoplasmic reticulum profile, free ribosomes and an occasional Golgi apparatus. Cytochemical studies showed a positive reaction for alpha-naphthyl butyrate esterase, which was completely inhibited by sodium fluoride, a diffuse positive reaction for periodic acid-Schiff, and a negative result for alkaline phosphatase and peroxidase. A large population of YAP cells reacted with the CD4, CD11b, CD25 and CD33 surface markers, but not with CD2, CD3, CD8 or CD19. We also found that YAP cells produced considerable amounts of TNF alpha, which was detected in the culture supernatant when the cells were treated with 1 ng/ml 12-O-tetradecanoylphorbol-13-acetate (TPA). Chromosome analyses showed that YAP cells contained a variety of marker chromosomes. It should be stressed that YAP cells were derived from a patient with a non-neoplastic disorder, whereas most monocytic cell lines previously reported are of malignant origin. This newly established cell line might be valuable for studying the pathogenesis of psoriasis, especially the role of monocytes/macrophages in the aetiology of the disease.

Adult↗
PubMed1996

A case of advanced gastric cancer complicated by severe toxicity induced by a combination of tegafur, uracil and mitomycin C, and associated with abnormal pharmacokinetics.

A 60-year-old female patient with gastric cancer and lymph node and liver metastases was treated with a combination of tegafur and uracil (UFT) (375 mg/m2/day) and mitomycin C (MMC) (5 mg/m2 once weekly). On day 15, when diarrhea appeared, chemotherapy was stopped immediately. On day 21, the WBC decreased to 900/microl and high fever developed. Despite treatment with granulocyte colony-stimulating factor and antibiotics, leukopenia persisted and the patient went into septic shock on day 26. On day 34, WBC increased to 5,400/microl and she recovered, with reduction in the size of the lymph node and liver metastases. Pharmacokinetic examination after intravenous injection of low-dose MMC (0.5 mg/m2) showed a markedly high peak plasma concentration (PPC), a large area under the time-versus-concentration curve (AUC) and reduced clearance. Similarly, oral administration of UFT (tegafur 300 mg/body) produced a relatively higher PPC and a larger AUC of 5-fluorouracil (FU). The activity of dihydropyrimidine dehydrogenase, the rate-limiting enzyme in the metabolism of FU, in peripheral mononuclear cells was within the normal range (0.265 nmol/min/mg). MMC is believed to have played a large part in inducing the severe toxicity observed in this patient. Physicians should be aware of the possibility of severe toxicity during treatment with UFT and MMC, although details of its incidence and mechanism are unclear.

Adenocarcinoma↗
PubMed1996

A case of herpes zoster associated with colitis.

A 58-year-old Japanese woman who had herpes zoster in association with colitis was successfully treated with intravenously administrated acyclovir. Vesicular lesions with red haloes ranged from the left side of her buttock to the left extremity, corresponding to the L4 to S2 dermatomes. Her colitis was considered to have been induced by varicella-zoster virus, based on the facts that the clinical courses were correlated and that the innervation of the affected site of the colon corresponded to an infected dermatome (S2).

Acyclovir↗