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進化における両生類の陸生適応と腎臓の多様性
Get PDFapplication/pdfThe amphibia bridge the phyletic gap between the aquatic fishes and the terrestrial vertebrates. This transition has involved many interesting changes of metabolism. In this short review, we have attempted to summarize the kidney structure and functions of osmoregulation in the amphibia. Amphibians excrete the water absorbed through their skin as a dilute urine. The pronephros of tadpoles may start to work in the hatching stages, and the metanephros of tadpoles is well developed and functioning. The glomerular filtration rate is relatively large and glomerular intermittency is important for regulating urine production. The proximal tubule reabsorbs approximately 20-45% of filtered water and sodium. Absorption is driven by the basolateral Na^+, K^+-ATPase common to all tubular cells. The diluting segment, an early part of the distal nephron, highly develops basolateral interdigitation and reabsorbs approximately 40% offiltered Na^+, K^+, and Cl^-, but is impermeable to water; thus, this part results in the formation of hypo-osmotic tubular fluid. In the late distal tubule, the primary mechanism of reabsorption may be via a luminal NaCl synporter, driven by the ubiquitous Na^+, K^+-ATPase on the basolateral membrane. In collecting tubules, there are two types of cells, the principal cells and the intercalated cells. Many hormonal and nervous regulations are involved in the glomerular filtration rate and reabsorptions in the amphibian nephrons.journal articl
口内法X線撮影法の技術評価:臨床研修医の相互実習から
Get PDFapplication/pdfClinical training of dental interns will be required by law, starting in 2006. In view of this Matsumoto Dental University set up the Department of Interdisciplinary Dentistry in 2001. In this department, one-year training of clinical interns is given, and as a curriculum for clinical interns in intra-oral radiography, the interns' mutual practice is performed, so that interns can reconfirm the techniques and prepare themselves for performing this radiography in patients. We recently conduted a technical evaluation of the intra-oral radiography performed by clinical interns in 2001 and 2002, the results of which were as follows: 1. In intra-oral radiography, individual interns' degree of success was 89% at the highest and 29% at the lowest, with an average of 58%. 2. The degree of success by region in the upper jaw was in the order of the anterior teeth region, the canine site, bicuspid site, and the molar region. In the lower jaw, the degree of success was in the order of the anterior teeth region, the canine site, the bicuspid site, and the molar region. 3. Failure by region in radiography was due to poor vertical angle, poor positioning of X-ray film, corncut, and poor horizontal angle. 4. In the analysis of causes of failure in radiography at the molar region in the upper and lower jaws, many cases of poor positioning of film and poor vertical angle were observed in the upper jaw. In the molar region of the lower jaw, many cases of poor positioning of film and corncut were noted. From the above, it is considered necessary hereafter to train interns, before they perform radiography, regarding the correct techniques of radiography, using such aids as phantoms, models of the jaw, and videos ofintra oral-radiography actually being performed.journal articl
Laboratory evaluation of 10 permanent soft lining materials and some clinical observations
Get PDFapplication/pdfTen commercial soft lining materials were selected to be representative of the types currently available including plasticised acrylic, silicone and fluorine-containing materials. These have been investigated in terms of their tensile, tear and hardness properties. With the exception of tear strength, where silicone materials had the lowest values, there appeared to be no correlation between material type and property. All but two of the materials had hardness values in the range of 30.3 to 43.7. The general conclusion was that the materials selected showed a large variability in the properties investigated. Regarding clinical aspects of some soft lining materials used for acrylic resin denture bases, it was appeared that colour change and deterioration occurred.journal articl
咬合高径の生理的意義
Get PDFapplication/pdfOcclusal vertical dimension, the distance between the mandible and maxilla, is considered to be the main factor in the determination of an individual's ability to effectively perform oral functions such as mastication, speaking, and swallowing. The present paper first describes the physiological significance of determining an occlusal vertical dimension appropriate for each patient, utilizing the subject's occlusal sensation. Secondly, the physiological mechanism producing occlusal sensation and its relation to masticatory force control are discussed, depending on the behavior of muscle spindles in the jaw-closing muscles. Raising or reducing the occlusal vertical dimension alters the length of jaw-closing muscles, resulting in changing the sensitivity of the muscle spindles. The higher brain must always be required to compensate for such change in spindle sensitivity to perform mastication smoothly, which may fatigue the brain and cause neurological symptoms associated with malocclusion. The occlusal vertical dimension should not arbitrarily be changed, exceeding the physiological range for the individval patient to feel comfortable.journal articl
上下顎第三大臼歯までの排列を行った抜歯症例
Get PDFapplication/pdfAfter correction of discrepancy by four first premolar extractions in cases of severe crowding, we occasionally extract four third molars. This means the extraction of eight teeth for the purpose of orthodontic treatment. In this article, a case of crowding treated by a multibracket appliance in order to get good occlusion and profile, not only with three premolars and one canine extracted, but also with the correction of four third molars was reported. The patient was diagnosed as Angle Class I with severe crowding and impacted upper left canine with a woman for age 15 years old 10 months in the first examination. The treatment plan was as follows: 1) tooth brush instruction 2) left upper side canine, right upper side premolar and lower premolar extraction 3) reinforced anchorage by Nance' holding arch 4) retention by removal appliance Correction of both profile and severe crowding was achieved after treatment, and the patient obtained stability of occlusion due to the alignment of the four third molars into each arch. In extraction cases, it is important that we predict eruption space and that we align all third molars after their eruptions. We should keep stable results in this case for a long period.journal articl
Co-Cr合金の鋳造に関する研究 : 各種リン酸塩系埋没材による比較
Get PDFapplication/pdfChromium Cobalt alloy exhibits excellent corrosion resistant and mechanical properties, with half of a specific gravity than that of gold alloy.Since, Co-Cr alloy has high melting temperature, casting is usually done with phosphate bonded investment.There arise problems with the handling of phosphate bonded investment in investing procedure and, fusing of the investment to castings, resulting to surface roughness and, final fitness of the casting. Three kinds of phosphate bonded investment, VELVETY, UNIVEST Silky, and CERAMIGOLD, were examined with several points of interests. In conclusion, VELVETY exhibited excellent handling ease, suitable mold strength, and good fitness of casting among the three investments tested.journal articl