Biomedical subjects
S Sobue
Publications and source records attributed to S Sobue.
Epidemiological survey of Streptococcus mutans among Japanese children. Identification and serological typing of the isolated strains.
An epidemiological investigation was carried out to identify and determine the serotypes of Streptococcus mutans from carious lesions of young Japanese children. For this purpose, a direct fluorescent antibody technique was mainly used. Fluorescein isothiocyanate-conjugated antibodies were prepared for the five known serotypes of S. mutans. Cross reactions and nonspecific reactions were eliminated by adsorption, counterstaining, or DEAE-cellulosecolumn chromatography. Agar-gel immunodiffusion was used to distinguish between serotypes a and d. The epidemiological survey suggested that serotype c strains were most prevalent in dental plaques of Japanese children. The d and e serotypes were rare and serotypes a and b were not detected. It was also noted that more than one serotype of S. mutans could be found in the same locus of a carious lesion and that there might be no relationship between the degree of caries and the causative serotype(s) of S. mutans.
Inhibition of rat dental caries by dextranase from a strain of Spicaria violacea.
Dextranase AD17 obtained from a culture liquor of a strain of Spicaria violacea was assessed for its ability to inhibit the development of dental caries in conventional Sprague-Dawley rats which had been infected with one of the Streptococcus mutans strains. MT6R (serotype c), OMZ 176R (d), or MT-703R (e). These experiments showed that caries was significantly inhibited when rats were given cariogenic diets No. 2000 and drinking water containing AD17 at a concentration of 10 units/g, as compared to control rats not given dextranase. The inhibitory effects of AD17 were more prominent in smooth surface caries than in total caries. AD17 had a tendency to retard both the establishment of inoculated S. mutans and plaque deposition on tooth surfaces. However, S. mutans could be implanted in the rat oral cavity after repeated inoculation of the bacteria, even in the presence of AD17. These results suggest that the anticaries activity of AD17 is due to not only inhibition of adherence of S. mutans cells on tooth surfaces but also to physiochemical changes of dental plaque formed under the enzymatic action of AD17. Preliminary histophatological examination showed that AD17 had no significant toxicity in rats.
[X-ray microbeam diffraction studies on the effect of diamine silver fluoride].
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Caries preventive effects of SrF2-cement filled in the proximal portion of acrylic space maintainer.
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Effects of diammine silver fluoride on tooth enamel.
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Effect of topically applied ammoniacal silver fluoride on dental caries in children.
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Inhibitory effects of oolong tea extract on caries-inducing properties of mutans streptococci.
The inhibitory effects of oolong tea extract (OTE) on the caries-inducing properties of mutans streptococci were examined in vitro. OTE reduced the rate of acid production by mutans streptococci accompanied with the retardation of growth rate of mutans streptococci, while the action by chromatographically isolated oolong tea polyphenol (OTF6) was weak. On the other hand, both oolong tea products decreased cell surface hydrophobicity of almost all the oral streptococci examined in the present study, and also induced cellular aggregation of Streptococcus mutans, Streptococcus oralis, Streptococcus sanguis or Streptococcus gordonii. In these reactions, OTF6 showed a more pronounced activity than OTE. Furthermore, the oolong tea products inhibited the adherence of mutans streptococci to saliva-coated hydroxyapatite. These results suggest that OTF6 may inhibit bacterial adherence to the tooth surfaces by reducing the hydrophobicity of mutans streptococci, and OTE may inhibit caries-inducing activity of mutans streptococci by reducing the rate of acid production.
Effect of dextranase prepared from Spicaria violacea on dental caries in the hamster.
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Dentin malformation with alveolar bone loss and periapical abscess formation.
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Endoscopic injection sclerotherapy for esophagogastric variceal bleeding in children with biliary atresia.
BACKGROUND/AIMS: To determine the safety and effectiveness of endoscopic injection sclerotherapy (EIS) for children with biliary atresia. METHODOLOGY: Subjects were 7 patients with biliary atresia with esophagogastric varices and variceal bleeding. Intravariceal injection using 5% ethanolamine oleate was performed under fluoroscopy until varices were eradicated. RESULTS: Endoscopic examination revealed that bleeding occurred in the junctional gastric varices in most of the cases. The mean number of EIS sessions required for obliteration of the varices was 2.3. In the observation period (mean: 21 months), recurrent esophagogastric varices occurred in 2 patients. One had variceal bleeding that was treated successfully by additional EIS. There were no severe complications associated with EIS. CONCLUSIONS: EIS under fluoroscopy was safe and effective for variceal bleeding in children with biliary atresia.
Coexistence of primary biliary cirrhosis and myasthenia gravis: a case study.
We present a case that suggests a relationship between primary biliary cirrhosis and myasthenia gravis. A 43-year-old Japanese woman was admitted to the Nagoya City University Medical School, First Department of Internal Medicine with abnormal liver function in August 1991. She had had ptosis of the right eye since 1990. She had not been treated for liver disease. Ptosis of the right eye and hepatomegaly were present. Serum laboratory examinations revealed elevated biliary enzymes and IgM levels; tests were positive for antimitochondrial antibody and antiacetylcholine antibody. Liver histology revealed chronic non-suppurative destructive cholangitis and led to a diagnosis of primary biliary cirrhosis. The tensilon test was positive. Electromyography with repetitive motor nerve stimulation revealed a neuromuscular junction defect; i.e., the primary characteristic of myasthenia gravis. The patient was diagnosed with myasthenia gravis. Although the development of myasthenia gravis has previously been reported in patients with primary biliary cirrhosis during D-penicillamine administration, this is a very rare case of the coexistence of both diseases before such treatment.
Treatment of solitary small hepatocellular carcinoma: consideration of hepatic functional reserve and mode of recurrence.
BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) recurs frequently after initial treatment. The subsequent prognosis varies with the mode of recurrence. Some patients die of hepatic failure even though the HCC is controlled. We consider the clinical stage (CS), using the modified Child-Pugh classification, to be an important factor influencing the prognosis of these patients. METHODOLOGY: To determine the most effective treatment for HCC, we examined 105 patients with solitary small HCC who were followed-up for more than 1 year after initial treatment. All of them were judged to be cured according to imaging or histological studies. The initial treatments were hepatic resection (n = 43), percutaneous ethanol injection therapy (PEIT, n = 33), and percutaneous microwave coagulation therapy (PMCT, n = 29). The modes of recurrence were divided into intrahepatic metastasis (IM) and multicentric occurrence (MO). RESULTS: Prognosis of MO was superior to that of IM in CS I patients, but there was no difference in prognosis between these modes in CS II. The hepatic resection group had more MO recurrences in CS I patients and more IM recurrences in CS II patients. IM developed frequently after PEIT and PMCT, regardless of the CS. Prognosis with hepatic resection was superior to that of the other treatments in CS I patients, but there was no difference in prognosis among the 3 treatment modalities in CS II patients. CONCLUSIONS: These data indicate that hepatic resection is the first choice for treating HCC in CS I patients, and that PEIT or PMCT is preferable for CS II patients.
Diagnosis of small hepatocellular carcinoma--imaging diagnosis and significance of tumor biopsy.
BACKGROUND/AIMS: To compare the effectiveness of different imaging modalities and the significance of tumor biopsy for diagnosing small hepatocellular carcinoma. METHODOLOGY: Nodules (n = 352) with diameters of 30 mm or less newly detected by periodic ultrasonography and computed tomography in 234 patients with chronic liver disease were investigated with magnetic resonance imaging and digital subtraction angiography. These findings were compared with histologic findings. Histologic diagnoses were dysplastic nodule (n = 23), well-differentiated hepatocellular carcinoma (n = 163), moderately differentiated hepatocellular carcinoma (n = 159), and poorly differentiated hepatocellular carcinoma (n = 7). We compared three groups based on-diameters of 10, 11-20, and 21-30 mm. Nodules were diagnosed as hepatocellular carcinoma if they had hypervascular staining on digital subtraction angiography, hyperintensity on magnetic resonance T2-weighted images, arterial phase enhancement on enhanced magnetic resonance imaging, or low-high-low density on enhanced computed tomography. RESULTS: Imaging alone was sufficient to diagnose hepatocellular carcinoma in 66.3% of the well-differentiated nodules and 91.6% of the moderately and poorly differentiated nodules (P < 0.001) The size of the nodule influenced the diagnosis of hepatocellular carcinoma by imaging alone in 65.5% (< or = 10 mm), 77.2% (11-20 mm), and 92.3% (21-30 mm) (< or = 10 vs. 21-30: P < 0.0001, 11-20 vs. 21-30: P < 0.0005). It was impossible to determine the degree of differentiation of the hepatocellular carcinoma by imaging alone. CONCLUSIONS: The effectiveness of imaging for the diagnosis of hepatocellular carcinoma improved with decreasing differentiation and increasing diameter of the nodules. Tumor biopsy was required to make a histological accurate diagnosis.
Simultaneous presence of a congenitally missing premolar and supernumerary incisor in the same jaw: report of case.
Supernumerary teeth and hypodontia can be regarded as opposite developmental phenomena. An eight-year-old girl presented a concomitant occurrence of a supernumerary tooth and two congenitally missing teeth. The supernumerary tooth was found in the left maxillary incisor region, while the left second premolar in the maxilla and the left lateral incisor in the mandible were congenitally missing. The supernumerary tooth showed a similar color and morphology to those of the maxilla lateral incisor, and the lateral incisor on the mesial side was diagnosed as a supernumerary tooth from dental age, eruption time, and mesiodistal crown dimension. The supernumerary incisor was guided labially to cure an anterior cross-bite, and the lateral incisor, canine, and first premolar were guided distally to compensate for the space left by the congenitally missing left second premolar.
Oral manifestations of Ehlers-Danlos syndrome type VII: histological examination of a primary tooth.
A two-year, 2-month old girl with Ehlers-Danlos syndrome Type VII is described. The patient presented with bleeding after tooth brushing, and exhibited microdontia and yellow discoloration of teeth. She had carious teeth, but did not exhibit periodontal disease, poor wound healing after extraction, radiographic evidences of pulp stones, or malformed roots. Microscopic examination of a decalcified section of an extracted tooth stained with H & E demonstrated some inclusions in the dentin, around which collagen was either missing or scanty, as confirmed by counterstaining with van Gieson's solution. The sections of pulp stained with van Gieson's solution showed an abnormal pattern of fibrous tissue. Furthermore, the radiopacity of the dentin of this patient was significantly higher than that of the control dentin.
Dental findings of children with biliary atresia: report of seven cases.
Patients with congenital biliary atresia (CBA) showed green staining of the teeth and soft tissues. Current cases of biliary atresia show various degrees of green staining in the primary and/or permanent dentition, suggesting a correlation between the degree of staining and the severity of the disease. Rampant caries was found in five out of seven patients. The importance of meticulous oral hygiene should be emphasized.
Oligodontia in the primary dentition with permanent successors: report of case.
A case of oligodontia in the primary dentition with corresponding permanent successors is described. A two-year-old Japanese boy was admitted to the pedodontic clinic with the chief complaint of congenitally missing primary teeth. The boy appeared to be normally developed and was in good physical health. There was no history of trauma, extraction, or exfoliation of primary teeth. Clinical examination showed that eight anterior teeth were missing. Also, a canine and three first molars were much smaller in size and were malformed. However, radiographic examination at age four years, ten months showed that all of the permanent tooth germs--including the corresponding successors of congenitally missing primary teeth--were evident.