Biomedical subjects
Publications and source records attributed to Y Yuasa.
A 55-year-old male patient with acute onset of abdominal pain was examined. He had no apparent history of abdominal trauma or bleeding tendency. MRI showed three layered architecture, so-called "ring sign" distinctive of hematoma. MRI seemed to be very useful in non-invasively diagnosing intramural duodenal hematoma.
Eighteen cases with bladder tumors were examined by means of superconducting MRI. Sequences used were spin echo (TR/TE (msec) = 500/20 as T1WI (weighted image) and 1500/80 as T2WI) and serial "fast spin echo (fast SE)" pre/post Gd-DTPA administration. "Fast SE" was a new technique offering a distinct T1WI (TR/TE = 100/14, utilizing a 14 second breath hold). Slice thickness of "fast SE" was 10 mm and slice plane was selected perpendicular to the tumor base to detect the extent of invasion. Serial scan of "fast SE" was performed before and immediately after 0.1 mmol/kg Gd administration. Scanning was completed before the bladder was opacified by Gd. Tumor and normal mucosa were both markedly enhanced whereas the surrounding muscle layer remained hypointense. On delayed scan, the elevated character of the tumor was outlined by opacified urine but the distinction between the mucosa and the muscle layer became unclear. Total cystectomy (TC) was performed in 6 of 18 cases and pathological tumor extension was correlated with MR findings. Transurethral resection (TUR) was performed in the remaining 12 patients, and the tumor extension was assessed by follow-up biopsy after TUR. Intact liner hypointensity indicated superficial lesions (= less than pT2), while disruption of the linear hypointensity corresponded pathologically to deep muscle invasion (= greater than pT3a). Accuracy of serial "fast SE" in tumor staging was 94% (17/18). Serial "fast SE" allowed the distinction of superficial from invasive tumors more accurately than conventional studies, and therefore assisted in choosing the correct operative method.
To elucidate the mechanism of polyp formation in familial polyposis coli patients, cDNA clones, expressed differently between normal colonic mucosae and polyps, were screened. Three polyp-derived cDNA clones showed increased levels of transcription under neoplastic conditions. Among them, clone P6 was determined to be derived from the mtDNA encoding parts of subunit 1 of NADH dehydrogenase and 16S rRNA. The number of copies and restriction enzyme patterns of the mtDNA did not vary in either normal or neoplastic tissues, and a level of different mitochondrial mRNA was increased in the same proportion, suggesting a change in the rate of synthesis and/or degradation of the mtRNA. No cDNA clone which was expressed higher in normal colonic mucosae than in polyps was isolated from the cDNA library derived from normal mucosae.
Recently, some radiologists using non-ionic contrast media for angiography have noted the increased tendency of thrombus formation in the injection syringe or angiographic catheter contaminated with blood. In vitro studies by some authors have shown that non-ionic contrast media had only a slight anticoagulative effect as compared with ionic contrast media. But the in vivo studies comparing the anticoagulative effect of both ionic and non-ionic contrast media have not been performed previously. We investigated the effect of non-ionic and ionic contrast media on platelet aggregation in 40 patients undergoing angiography. The in vivo study revealed a negligible influence of both non-ionic and ionic contrast media on systemic platelet aggregation. The dose of contrast media also showed no significant correlation with platelet aggregation. Our study suggests that the data from in vitro experiments cannot be extended to in vivo study as for the relationship between contrast media and their anticoagulant effect.
Masticatory function of 10 telescope denture wearers in the Kennedy class II mandible patients was evaluated with electromyography. Electromyographic activity during mastication with kamaboko and peeled raw carrot was recorded from bilateral masseter and the anterior part of temporal muscles at each interval: Before treatment, immediately after denture insertion and 2, 4, 6, 8 weeks after respectively. Mean of duration, interval and cycle of EMG activities, coefficient of variation and average variation were calculated. The results were as follows: 1. Means of duration and cycle times decreased immediately to 2 weeks after denture insertion. 2. EMG activities during raw carrot chewing became regular immediately to 2 weeks after denture insertion, and within 4 weeks in kamaboko chewing. These results suggest that telescope dentures would be adapted to stomatognathic system within short period after denture insertion.
One of the most consistently frustrating areas of maxillofacial rehabilitation is the treatment of patients who have had radical cancer surgery of the tongue, floor of the mouth, and mandible. The patient described in this report, was a 66-year-old man who had squamous cell carcinoma of the right jaw. The right body of the mandible distal to the right cuspid was resected, and this part of the mandible was not reconstructed. For this mandibulectomy patient, we have treated with the removable partial denture using 30 degree teeth and TS telescope crown as retainer, registrating maxillomandibular relation with Gothic arch tracer and MKG. In addition, masticatory function in this patient was evaluated on tooth contact, tapping pattern, masticatory efficiency and rhythm of mastication. Consequently, 4 to 8 weeks later, tapping pattern and centric occlusion was stabilized, and masticatory function was improved. We will continue to observe this case in long term.
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Intraarterial digital subtraction angiography (IADSA) with carbon dioxide (CO2) was performed on 41 patients with liver or renal diseases. CO2 produced no hypersensitivity reactions, and the pain or feeling of warmth was relatively mild compared with iodinated contrast media. Although the image quality of the arterial or capillary phase was inferior to that with iodinated contrast media, the detectability of arteriovenous shunting was excellent. IADSA with CO2 may become an effective method for detecting arteriovenous shunting which cannot be demonstrated with conventional angiography or DSA with iodinated contrast medium.
As reported previously (Namba et al., 1985; Namba, 1985), normal human fibroblasts were transformed into immortal cells with abnormal karyotypes by Co-60 gamma-ray irradiation. These immortally transformed cells (KMST-6) showed no clonability in soft agar and were not tumorigenic. However, by treatment with Ha-ras oncogenes derived from a human lung carcinoma or Harvey murine sarcoma virus, the KMST-6 cells acquired elevated clonability in soft agar and transplantability in nude mice. All the tumors produced grew progressively without showing regression and killed the mice. The tumors were also serially transplantable into other mice. The Ha-ras oncogene alone did not convert normal human fibroblasts into either immortal or tumorigenic cells. Our current data suggest that gamma rays worked as an initiator of carcinogenesis in normal human cells, giving rise to chromosome aberrations and immortality, and the Ha-ras oncogene played a role in the progression of the immortally transformed cell population to a neoplastic one showing enhanced colony formation in soft agar and tumorigenicity in nude mice.
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The purpose of present study is to establish a method that should enable us to keep a human gall-bladder epithelial tissue alive for a period long enough to observe morphological change after an exposure to a certain carcinogenic agents. Human gall-bladder epithelia obtained from surgically resected specimen were kept as an explant organ culture in vitro for the first 2 weeks. They were, then, xenotransplanted to the subcutaneous (S.C.) space of the athymic nude mice. The gall-bladder tissues obtained from 7 cases of cholecystolithiasis and 1 case of cholecysto-choledocholithiasis were used as materials in the present study. And the longest survivor among them in the nude mice was extensively studied in the present paper. After an interval of 4 to 27 weeks, the xenografts were recovered from the recipient mice and studied by light microscopy and histochemistry. The morphological changes of the explant epithelia during the organ culture were also studied. Parts of the explants were implanted in 6 nude mice. Each of the mice received 3 pieces of explants on the s.c. space in both of their flanks. All xenografts showed subcutaneous cyst formation. The cyst obtained 4 weeks after the implantation was consisted of a monolayer of cuboidal epithelial cells and those recovered from the recipient mice 24 and 27 weeks after the implantation were consisted of well growing columnar and cuboidal epithelial cells. In addition, sinus-like structures were observed beneath the cystic epithelia. The viability of the cells was excellent.(ABSTRACT TRUNCATED AT 250 WORDS)
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We examined the distribution of trimetaphosphatase (TMPase)-positive basal lysosomes in pancreas, parotid, submandibular, sublingual, and exorbital lacrimal glands from rats, rabbits, and guinea pigs. The location of the basal lysosomes was compared to that of the acid phosphatase (AcPase)-positive lysosomes. In all of the tissues examined from rat and rabbit, AcPase activity was localized primarily to the Golgi region. Reaction product was localized in GERL, immature secretory granules, and lysosomes lying adjacent to the Golgi apparatus. TMPase activity was found in basal lysosomes and in occasional elongated lysosomes adjacent to the Golgi apparatus. In guinea pig, the distribution of TMPase activity was identical to that seen in the other two species, but a significant number of lysosomes in the basal region of the cells also contained AcPase activity. These results confirm and extend our previous finding (J Histochem Cytochem 31:1209, 1983) that exocrine acinar cells possess two distinct populations of lysosomes. The lysosomes in the Golgi region contain both AcPase and TMPase activity, whereas those in the basal portion of the cells are reactive predominantly for TMPase. The functional significance of the two populations of lysosomes is not understood at present.