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K Toriyama

Publications and source records attributed to K Toriyama.

At least 37 records · Page 2Linked to original sources
PubMed1998

A comparison of epidemiologic, histologic, and virologic studies on Hodgkin's disease in western Kenya and Nagasaki, Japan.

Rapid progress in molecular technologies has enabled the detection of several oncogenic viruses in various types of tumors. The pathogenesis of Hodgkin's disease is suggested to have a strong association with Epstein-Barr virus (EBV). However, Hodgkin's disease related to EBV shows a wide geographic variation in epidemiology. These variations among different populations suggest an interaction of environmental factors and a direct role of EBV infection. Therefore, we performed a comparative study on epidemiologic, histologic, and virologic features of Hodgkin's disease among those in the western part of Kenya and in Nagasaki, Japan. The age distribution of Hodgkin's disease showed a distinct peak in the 0-9-year-old age group in Kenya, and a higher and lower peak in the 60-69- and 30-39-year-old age groups, respectively, in Japan. The most common subtype of Hodgkin's disease in both countries was mixed cellularity, followed by nodular sclerosis, lymphocyte depletion, and lymphocyte predominance. Mixed cellularity showed a significantly high prevalence among Kenyan children nine years of age or younger. Using the in situ hybridization method, EBV-encoded RNA (EBER-1) was detected in 79% of the Kenyan cases and 59% of the Japanese cases, with the mixed cellularity subtype showing a strong correlation with EBER-1. There was 100% positivity in both countries in those less than nine years old. These results suggest that EBV plays a more direct role in the pathogenesis of Hodgkin's diseases in Kenya, especially in cases among young children and also in Japanese children. Environmental and/or genetic factors may have a role, in addition to EBV, in the pathogenesis of Hodgkin's disease, especially in Nagasaki, Japan.

Adolescent↗
PubMed1997

Direct cloning of the Brassica S locus by using a P1-derived artificial chromosome (PAC) vector.

Self-incompatibility of Brassica is regulated by the S locus, which contains several genes including SLG and SRK. We found that both SLG and SRK genes were located at an approx. 80-kb MluI fragment in an S9 haplotype of B. campestris. Therefore, we cloned this MluI fragment into a BssHII site of the P1-derived artificial chromosome (PAC) vector. The utility of the direct cloning method is discussed in this study.

Bacteria↗
PubMed1997

Three members of the S multigene family are linked to the S locus of Brassica.

Two self-incompatibility genes in Brassica, SLG and SRK (SLG encodes a glycoprotein; SRK encodes a receptor-like kinase), are included in the S multigene family. Products of members of the S multigene family have an SLG-like domain (S domain) in common, which may function as a receptor. In this study, three clustered members of the S multigene family, BcRK1, BcRL1 and BcSL1, were characterized. BcRK1 is a putative functional receptor kinase gene expressed in leaves, flower buds and stigmas, while BcRL1 and BcSL1 are considered to be pseudogenes because deletions causing frameshifts were identified in these sequences. Sequence and expression pattern of BcRK1 were most similar to those of the Arabidopsis receptor-like kinase gene ARK1, indicating that BcRK1 might have a function similar to that of ARK1, in processes such as cell expansion or plant growth. Interestingly, the region containing BcRK1, BcRL1 and BcSL1 is genetically linked to the S locus and the physical distance between SLG, SRK and the three S-related genes was estimated to be less than 610 kb. Thus the genes associated with self-incompatibility exist within a cluster of S-like genes in the genome of Brassica.

Amino Acid Sequence↗
PubMed1997

Clinical results of cultured epithelial cell grafting in the oral and maxillofacial region.

Cultured epithelium has proven to be a good grafting material for skin defects. In our experience two kinds of epithelial cells, skin keratinocytes and mucosal cells, have been used to fabricate cultured epithelial sheets and autografted to the patients. Traumatic scars of the face were treated by cultured epidermal epithelium (CEE). The skin graft in the oral cavity was replaced by mucosa using cultured mucosal epithelium (CME). Also, the CME was applied to the skin defects at the donor sites of split-thickness skin grafts. Postsurgical follow-up showed good results. As a result, CME was useful in improving the biological environment around the abutments of dental implants, and it also promoted the re-epithelialization of skin defects. From our investigations, CEE/CME are promising treatment modalities which can reduce pain and speed up the healing process in burn patients. Therefore, cultured epithelium banks are worth establishing for auto- and allografting of skin/mucosal defects.

Adult↗
PubMed1997

Evaluation of heparin-binding growth factors in rescuing morphogenesis of heparitinase-treated mouse embryonic lung explants.

In vitro development of embryonic mouse lung explants was hindered by digestion with heparitinase, which removed about 40% of [35S] sulfate-labeled heparan sulfate synthesized. The enzyme-treated explants were inhibited in branching morphogenesis and the mesenchymal tissue was thin. Addition of basic fibroblast growth factor (bFGF), a typical heparin-binding growth factor, restored the inhibition caused by heparitinase in branching morphogenesis. Addition of midkine (MK), another heparin-binding growth factor, showed a weak effect on branching morphogenesis, but exhibited an effect in restoring development of mesenchymal tissue. These data together with the distribution of the factors indicate that both are involved in development of the lung. Heparitinase-treated explants can be useful models for evaluating roles played by various heparin-binding growth factors.

Animals↗
PubMed1997

Midkine, a retinoic acid-inducible heparin-binding cytokine in inflammatory responses: chemotactic activity to neutrophils and association with inflammatory synovitis.

Midkine (MK) is a retinoic acid-inducible heparin-binding cytokine. In the inflammatory synovitis of rheumatoid arthritis and osteoarthritis, MK was detected in synovial fluid, synoviocytes, and endothelial cells of new blood vessels. Normal synovial fluid and noninflammatory synovial tissue did not contain detectable MK. Therefore, MK showed inflammation-associated expression in these cases. Furthermore, MK was found to promote chemotaxis of neutrophils in the range of 10 ng/ml. The mode of action of MK was found to be haptotactic; the substrate-bound form of MK was the active one. MK is also known to promote fibrinolysis. These activities of MK are in agreement with the modes of MK expression in various pathological statuses, and thus MK is proposed to be an important molecule regulating inflammatory responses.

Adult↗
PubMed1997

[Two clinical case of spontaneous hemopneumothorax caused by aberrant vessel].

Spontaneous hemopneumothorax is a rare disease and intrathoracic bleeding reportedly occurs in the detached region of adhesive parietal pleura, aberrant vessel and cystic wall. We experienced two cases of bleeding most likely from the aberrant vessel. One patient was a 25-year-old male who had severe chest pain with dyspnea for four days. Chest X-ray revealed left pneumothorax and mediastinal shift to the right. Approximately 1500 ml of blood was aspirated from the left thoracic cavity. Since bleeding continued, emergency thoracotomy was performed. A restiform structure was noted in the bulla at the apex of the lung and the stump of the structure was considered as the source of bleeding. The other patient was a 29-year-old male who underwent emergency operation 16 hours after the massive bleeding amounting to 1800 ml. At the thoracotomy, a ruptured bulla at the apex of the collapsed lung with restiform structure was encountered. The bleeding point in the stump of the structure was ligated and the ruptured bulla was resected. In the histological study of these patients, an aberrant blood vessel was revealed in the restiform structure, which suggests the etiology of the bleeding. Their postoperative course was uneventful and had no symptom at the discharge. In the management of spontaneous hemopneumothorax, early thoracotomy should be the first consideration taking into account the massive bleeding from the aberrant vessel as in the cases.

Adult↗
PubMed1996

The pattern of pediatric solid malignant tumors in western Kenya, east Africa, 1979-1994: an analysis based on histopathologic study.

This study analyzed histopathologic specimens of 600 pediatric solid malignant tumors seen during the period 1979-1994 at the histopathology laboratories of the Rift Valley Provincial General Hospital in Nakuru, the Nyanza Provincial General Hospital in Kisumu, and the Uasin Gishu Hospital in Eldoret in western Kenya. The crude incidence rate of each malignancy per 100,000 children per year was calculated. The patterns of malignancies were examined with a focus on tumor incidence, age, sex, geographic, and ethnic distribution to relate the tumors to putative environmental and genetic causative factors. The six common tumors were Burkitt's lymphoma (33.5%), non-Hodgkin's lymphoma (21.8%), retinoblastoma (11.5%), Kaposi's sarcoma (6.1%), nephroblastoma (4.5%), and Hodgkin's disease (4.1%). Significantly high crude incidence rates for lymphomas and Kaposi's sarcoma showed a characteristic ethnogeographic distribution. The majority of the tumors were found concentrated around Lake Victoria and showed decreasing occurrence as one moved towards the semi-arid and highland areas. We concluded that environmental factors seem to play a major role in childhood tumors in western Kenya.

Adolescent↗
PubMed1996

Short report: herpes-like DNA sequences in African-endemic and acquired immunodeficiency syndrome-associated Kaposi's sarcoma.

Recently, the unique nucleic acid closely related to the herpes-like sequences has been found in acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS). We have confirmed the presence of herpes-like DNA sequences in six cases of AIDS-associated KS and three of the nine cases of African-endemic KS in adults, but not in eight cases of KS in children from the same area. These sequences were seen in a histologically early stage of KS. Our results suggest that herpes-like DNA sequences may play an important role in the pathogenesis of AIDS-associated KS.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Clinico-pathological predictive factors of response to interferon therapy in chronic hepatitis C.

We performed a clinico-pathological study to determine which pre-treatment factors could predict the response to interferon (IFN) therapy in 55 Japanese patients with chronic hepatitis C. Responses to the IFN therapy were evaluated as sustained response, relapse and non-response by the presence or absence of serum hepatitis C virus (HCV) RNA during the course of treatment and at least 6-months post-treatment. The numbers of sustained response, relapse and non-response were 16 (29.0%), 25 (45.5%) and 14 (25.5%), respectively. Eight out of 16 sustained response cases (50%) showed HCV genotype III. Eight among 10 patients with HCV genotype III (80%) were sustained responders. HCV genotypes were found to be correlated with the response to the IFN therapy (p < 0.0001). None of the histological features, the types of the IFN therapy and other clinical factors showed significant differences. These findings suggest that outcome of the IFN therapy in chronic hepatitis C can be predicted by a virological factor, and that HCV genotype III is a useful predictor of a favorable outcome.

Biopsy↗
PubMed1995

Femoral peak bone mass and osteoclast number in an animal model of age-related spontaneous osteopenia.

BACKGROUND: SAMP6 was developed as a murine model of age-related spontaneous osteopenia characterized by low peak bone mass. A morphometric study of the growing femur in SAMP6 and sex-matched SAMP2 at 10 days to 4 months of age was done to examine the pathogenic process related to osteopenia. METHODS: Age-related changes in cortical bone thickness, femur score, trabecular bone volume, thickness of epiphyseal growth plate, number of osteoclasts, and osteoclast surface were measured with a computerized image analyzer. Osteoclasts were examined cytomorphometrically after TRAP (tartrate resistant acid phosphatase) staining of the femoral sections. RESULTS: Cortical bone thickness and femur score increased significantly with age, while trabecular bone volume decreased significantly. Comparing mean values of cortical bone thickness, femur score and trabecular bone volume, we noted significantly lower mean values in SAMP6 than in SAMP2 mice. These significant inter-stain differences first became evident in 20-40-day-old mice, but there was no significant difference in thickness of the epiphyseal growth plate between the two strains. The mean values of the number of osteoclasts per unit bone surface length and of the osteoclast surface in SAMP6 were significantly greater than in age- and sex-matched SAMP2. Histograms of distribution of size of osteoclasts of 40-day-old male mice revealed that larger ones were more frequently seen in SAMP6. Furthermore, the ratio of osteoclasts/TRAP positive cells free in the bone marrow cavity was significantly higher in SAMP6 than in SAMP2. CONCLUSION: Activated bone resorption may play a role in the osteopenia seen in SAMP6.

Aging↗
PubMed1995

A cDNA clone encoding an IgE-binding protein from Brassica anther has significant sequence similarity to Ca(2+)-binding proteins.

Thirteen cDNA clones encoding IgE-binding proteins were isolated from expression libraries of anthers of Brassica rapa L. and B. napus L. using serum IgE from a patient who was specifically allergic to Brassica pollen. These clones were divided into two groups, I and II, based on the sequence similarity. All the group I cDNAs predicted the same protein of 79 amino acids, while the group II predicted a protein of 83 amino acids with microheterogeneity. Both of the deduced amino acid sequences contained two regions with sequence similarity to Ca(2+)-binding sites of Ca(2+)-binding proteins such as calmodulin. However flanking sequences were distinct from that of calmodulin or other Ca(2+)-binding proteins. RNA-gel blot analysis showed the genes of group I and II were preferentially expressed in anthers at the later developmental stage and in mature pollen. The recombinant proteins produced in Escherichia coli was recognized in immunoblot analysis by the IgE of a Brassica pollen allergic patient, but not by the Ige of a non-allergic patient. The cDNA clones reported here, therefore, represent pollen allergens of Brassica species.

Amino Acid Sequence↗
PubMed1995

Tapetum-specific expression of the gene for an endo-beta-1,3-glucanase causes male sterility in transgenic tobacco.

A cDNA for a pathogenesis-related endo-beta-1,3-glucanase isolated from soybean, was fused to an anther tapetum-specific promoter (Osg6B promoter) isolated from rice and the resulting chimeric gene was introduced into tobacco. The Osg6B promoter became active in the anther tapetum during formation of tetrads and the tapetal glucanase activity in the transgenic plants caused in a significant reduction in the number of fertile pollen grains. Most of the pollen grains were aberrant in shape, lacked germinal apertures and aggregate of the pollen grains. Granules of beta-1,3-glucan, which have not previously been reported, were often observed to adhere to the surface of the pollen grains. Further observations revealed that the callose wall was almost absent in the pollen tetrads of transgenic plants. In wild-type plants, by contrast, the tetrads were surrounded by callose that was degraded soon after the tetrad stage to release free microspores. Thus, the introduced gene for endo-beta-1,3-endoglucanase under the control of the Osg6B promoter caused digestion of the callose wall at the beginning of the tetrad stage, a time that was just a little earlier than the time at which endogenous glucanase activity normal appears. These results demonstrate that premature dissolution of the callose wall in pollen tetrads causes male sterility and suggest that the time at which tapetally produced glucanase is activate is critical for the normal development of microspores.

Base Sequence↗
PubMed1995

Study on the aging changes of DNA and protein synthesis of bipolar and photoreceptor cells of mouse retina by light and electron microscopic radioautography.

The DNA and protein synthesis of the bipolar cells and photoreceptor cells of aging mouse retina from fetal to postnatal 1 year were studied by light and electron microscopic radioautography. Meanwhile the ultrastructure of these cells was observed by electron microscopy. The bipolar and photoreceptor cells incorporated 3H-thymidine from embryonic day 19 until 1 week after birth, while 3H-leucine from embryonic day 19 to postnatal 1 year. The 3H-thymidine labelled cells had undeveloped cell organelles in their cytoplasm. On the contrary, the unlabelled cells had well developed cell organelles, mainly mitochondria and endoplasmic reticulum in their cytoplasm. The mitochondria became elongated when the outer segments were well developed. The protein synthesis of the bipolar cells and photoreceptor cells as demonstrated with 3H-leucine labeling was vigorous at embryonic day 19 and early postnatal days when the inner and outer segments were formed. The peak of this phenomenon was observed at 1 day after birth. The activity of protein synthesis was also detected at the adult stage. However there was no significant fluctuation in any stages from 14 days after birth to 1 year.

Aging↗
PubMed1995

Molecular cloning of members of the S-multigene family in self-incompatible Brassica campestris L.

We isolated 12 groups of genomic clones that contained SLG-homologous regions from a genomic library constructed from an S9 homozygote of self-incompatible Brassica campestris. Both SLG9 and SRK9 genomic clones, which are located within the self-incompatibility (S) locus, were included in these groups. The promoter regions of SLG9 and SRK9 were completely identical for at least 200 bp upstream from their respective initiation codons (ATG). The five sequence elements (boxes I to V) that are conserved in the promoters of SLG and SRK genes were also found in the SLG9 and SRK9 clones. However, one conserved element (box III) unexpectedly lacked 7 of 11 bp, although box III has been considered necessary for expression in pistil. The other ten groups of genomic clones were classified into six SRK-like groups and four SLG-like groups. These results indicate that SLG, SRK, SLG-like, and SRK-like genes form a large S-multigene family in B. campestris.

Base Sequence↗