Biomedical subjects
M Nonaka
Publications and source records attributed to M Nonaka.
Perception of white in a 10 degree field.
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Intramitochondrial band-like structures in the epithelial cells of the rat seminal vesicle.
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Molecular cloning of rat and mouse membrane cofactor protein (MCP, CD46): preferential expression in testis and close linkage between the mouse Mcp and Cr2 genes on distal chromosome 1.
Human membrane cofactor protein (MCP, CD46) is widely distributed and is one of the plasma membrane complement inhibitors. We isolated cDNA clones encoding genetic homologues of human MCP from a rat testis cDNA library. Northern blot analysis indicated that rat MCP is preferentially expressed in testis, similar to what is found with guinea pig MCP. We identified several different cDNAs, which were presumably generated by alternative splicing from a single-copy gene. The most prevalent isoform corresponded to the Ser/Thr/Pro-rich C type of human MCP. Mouse MCP cDNA was cloned by polymerase chain reaction based on the nucleotide sequence of rat MCP. The deduced amino acid sequence showed 77.8% identity to rat MCP. Mouse MCP was also preferentially expressed in testis. Unique expression in testis in rat and mouse as well as guinea pig suggests that MCPs in these species not only act as complement regulatory proteins but may also have more specialized functions in fertilization or reproduction. Genetic mapping by linkage analysis indicated that the mouse Mcp gene is located on distal chromosome 1, closely linked to the complement receptor 2 (Cr2) gene.
Retroperitoneal bronchogenic cyst: a rare case showing the characteristic imaging feature of milk of calcium.
Bronchogenic cysts are rare congenital anomalies of the primitive foregut that are usually found above the diaphragm, and a retroperitoneal location is extremely unusual. Due to the low prevalence of these pathologies, their imaging features have seldom been described. We report a rare case of retroperitoneal bronchogenic cyst showing characteristic imaging features of milk of calcium on plain abdominal radiography and computed tomography.
Opsonic complement system of the solitary ascidian, Halocynthia roretzi.
To elucidate the molecular architecture and function of the possibly primitive complement system of the solitary ascidian. Halochynthia roretzi, cDNA clones for the third component (C3) and mannose-binding lectin (MBL)-associated serine protease (MASP) were isolated from the hepatopancreas cDNA library. The deduced primary structure of ascidian C3 (AsC3) shows overall similarity to mammalian C3 including a typical thioester site. Two distinct ascidian MASPs, termed AsMASPa and AsMASPb, have the same domain structure as mammalian Clr/ Cls/MASP-1/MASP-2. Both of them show a closer similarity to mammalian MASP-1 than to mammalian Clr/Cls/ MASP-2. Ascidian body fluid contains an opsonic activity which enhances phagocytosis of yeast by ascidian blood cells, and an antibody against AsC3 inhibits this opsonic activity. These results indicate that the lectin-dependent, opsonic complement system was present prior to the emergence of the vertebrates and well ahead of the establishment of adaptive immunity.
Benign solitary fibrous tumor of the parietal pleura which invaded the intercostal muscle.
A 29-year-old woman who underwent evaluation for a 3-month history of left-sided back pain proved to have a left pleural tumor accompanied by a bloody pleural effusion (cytological class II). Three years previously, a chest roentgenogram had been normal. The tumor originated from the parietal pleura at the level of the first three intercostal muscles and was excised completely in continuity with these muscles, including a margin of normal muscle. The tumor measured 15x12 cm and the pathologic diagnosis was benign solitary fibrous tumor; while the tumor invaded the intercostal muscles, no histologically malignant features were present. Long-term follow-up is planned because a possibility of local recurrence exists.
The mouse factor H allotypes with multiple amino acid replacement, H.1 and H.2 show indistinguishable co-factor activity for factor I.
The authors report the functional analysis of the purified mouse factor H allotypes H.1 and H.2, which were clearly distinguished from each other by an immunodiffusion test. Both allotypes acted as a co-factor for factor I in cleaving mouse C3b and we found no significant difference between their activities. The results strongly suggest that the function of mouse factor H for the co-factor activity has been well conserved between two allotypes.
Changes in tissue-plasminogen activator mRNA expression following cortical ablation in the rat brain.
Tissue plasminogen activator (tPA) has been used to treat acute thrombotic lesions. Roles other than the activation of fibrinolytic pathways have been suggested for tPA in the mature brain. We used the in situ hybridization technique to investigate the changes in tPA mRNA expression within the brain after cortical ablation. We found that expression of tPA mRNA started to increase diffusely in the cortex ipsilateral to the injury 6 h after ablation. This increase had become prominent 24 h after ablation. On d 5, the expression of tPA mRNA had returned to that of the control animals except for the area near the injury. We also found that administration of MK-801 before injury suppressed the increase of tPA mRNA in the ipsilateral cortex. These results suggest that the increase in tPA mRNA is likely to be mediated via activation of NMDA receptors.
A macrolide antibiotic, roxithromycin, inhibits the growth of nasal polyp fibroblasts.
Recently, the efficacy of macrolide antibiotics in cystic fibrosis and bleomycin-induced lung injury was reported. Nasal polyposis is a chronic inflammatory disease of the upper airway characterized by structural abnormalities including stromal fibrosis. Fibroblasts are resident cells thought to play an important role in the development of fibrosis. Although the effect of Roxithromycin (RXM) on inflammatory cells is well known, there is no evidence on the effect of RXM on fibroblasts. The purpose of the present study was two-fold: to examine the effect of RXM on the growth of fibroblasts in vitro and to examine the effect of RXM on the proliferation of fibroblasts in vivo. Nasal polyp fibroblast lines were generated from untreated patients, and those who were treated with RXM (300 mg/day) for one month before biopsy. Nasal polyp fibroblast lines from untreated patients were cultured for 72 hours with or without RXM, and the direct effect of RXM on fibroblast growth in vitro was examined by cell counting and 3H thymidine uptake. Next, we examined the in vivo effect of RXM on nasal polyp fibroblasts (NPFs) by comparing the growth characteristics of NPF lines from RXM treated and untreated patients. Finally, we examined the proliferating rate of NPF lines from the same patient before and after treatment with RXM. NPF lines that were treated with RXM exhibited a lower proliferating rate in vitro as compared to those that were not treated with RXM. Treatment of NPF lines with RXM suppressed the proliferation of fibroblasts in a dose-dependent manner. In addition, NPF lines from patients treated with RXM exhibited a lower proliferating rate in vitro as compared to NPF lines from the same patient taken before RXM treatment. We demonstrated that RXM directly suppressed nasal polyp fibroblast proliferation, and that this effect of RXM on fibroblast growth was persistent, indicating that RXM may prevent the progression of nasal polyposis by inhibiting the development of fibrosis.
In vitro fitting accuracy of copy-milled alumina cores and all-ceramic crowns.
PURPOSE: The purpose of this study was to evaluate the marginal and internal fit of alumina cores and all-ceramic crowns in a new preparation design for abutment teeth devised for copy milling. MATERIALS AND METHODS: Using conventional dies and dies from the new type of preparation design, 20 alumina cores were produced by copy milling, 10 cores in each die type. Also using the new type of die, another 10 final crowns were fabricated. Each of the 30 specimens was returned to its original die and embedded in epoxy resin. Each specimen was then sectioned labiolingually and measured for gaps at the margin, in the central area, and at the incisal edge. RESULTS: The alumina cores fabricated using the new type of die had mean gaps of 30 to 40 microns at the margins of the labial and lingual sides, which was significantly smaller than the gaps (67 to 130 microns) found in the alumina cores produced with the conventional type of die. The final crowns had mean gaps of 44 to 63 microns at the margins and on the inner surfaces. There was no significant difference in the gaps between the alumina cores produced using the new type of die and those found in the final crowns. CONCLUSION: The new type of die was effective in allowing the fabrication of all-ceramic crowns that provide excellent marginal and internal fit by copy milling.
Retrospective study on the effects of lipiodolization before a potentially curative hepatectomy for colorectal liver metastases: long-term results of a pilot study.
BACKGROUND/AIMS: Lipiodolization, a selective regional cancer chemotherapeutic modality using lipiodol plus anticancer drugs, can prolong the survival time of patients with unresectable liver cancer. A preliminary study was conducted with adjuvant lipiodolization before a potentially curative hepatectomy for patients with metachronous colorectal liver metastases. The ultimate aim of this study was to improve the long-term survival after hepatectomy. METHODOLOGY: Twenty-one consecutive patients with colorectal hepatic metastases were included in this study. Seven patients underwent preoperative lipiodolization, while the remaining 14 patients did not receive any preoperative adjuvant therapy. The clinicopathological features and prognoses of these patients were investigated. The median follow-up period after a curative hepatectomy was 56 months. RESULTS: The clinicopathological factors did not differ markedly between the 2 groups. However, the cumulative survival rate of the 7 patients receiving preoperative lipiodolization was significantly (P < 0.05) better than that in those not receiving any preoperative treatment. CONCLUSIONS: Based on the above encouraging findings, we therefore propose that a prospective randomized trial should be carried out to confirm the beneficial effects of our adjuvant chemotherapeutic modality on patient survival following a curative hepatectomy for the patients with colorectal liver metastases.