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Biomedical subjects

T Sakae

Publications and source records attributed to T Sakae.

At least 73 records · Page 4Linked to original sources
PubMed1986

Demonstration of structural variation in rat incisor dentin as determined by the x-ray Laue method.

Rat incisor dentin was studied by an x-ray micro-Laue method to investigate the relationship between crystal orientation and structural variation in the dentin. The results showed that crystal orientation was very poor in the labial dentin, but that the crystals were well-oriented in the lingual dentin. In the lingual dentin, the axis of crystal orientation was parallel to the tooth axis. It is suggested that the difference in crystal orientation between the lingual and labial dentin is due to the different mode of calcification between the two.

Animals↗
PubMed1985

Analysis of vaterite microspherolith deposits on a pure cholesterol gallstone by X-ray diffraction, X-ray microanalysis and infrared absorption techniques.

Minute globular concretions of light-green and light-brown colour were found as deposits in the pits at the rough surface of a pure cholesterol gallstone. They were analyzed by scanning electron microscopic, X-ray diffraction, X-ray microanalytical and infrared absorption spectrometric methods. In scanning electron microscopy, the concretions appeared as ovoid microspheroliths varying from 5 to 30 micron in size. The microspheroliths presented smooth and rough surfaces; the reason for these different types of surface remained unclear. X-ray diffraction and infrared absorption analysis revealed that the microspheroliths were mainly composed of vaterite and the host plate-like crystals were cholesterol. By energy-dispersive X-ray microanalysis, large quantities of calcium without significant quantities of phosphorus were detected in the microspheroliths. Calcium was absent in the plate-like crystals and could not be detected in the central part of the stone. In the pigmented periphery of the stone, some silicon and iron were found. The presence of calcite, aragonite and iron-containing pigment materials in the concretion is suggested. From the textural point of view, the analytical data strongly suggest that the stone-forming conditions suddenly changed from a cholesterol-favourable stasis condition to a condition favoring the deposition of calcium carbonate possible as the result of haemorrhage.

Absorption↗
PubMed1985

Crystallographical analysis of tooth enamel using milligram samples.

An X-ray diffraction microanalytical method, in which sample is loaded onto a silver membrane filter, was applied to assess the crystal content in tooth enamel. Each enamel powder was first examined at room temperature, and then examined again at intervals after heating to 200, 400, 600, 800, and 1000 degrees C. The hydroxyapatite composition weight and crystal weight of the samples were derived from the standard calibration curves. The "crystal content ratio" was defined as the ratio of crystal weight to sample weight. The following results were obtained: (1) beta-tricalcium phosphate (beta-TCP) replaced the hydroxyapatite after heating at the high temperatures; (2) the "crystal content ratio" in the tooth enamel increased with the rise in temperature; and (3) the lattice parameters of the enamel apatite and the beta-TCP were changed by the heating. The X-ray diffraction technique has the potential to analyze the crystal content using milligram samples.

Calcium Phosphates↗
PubMed1984

Scanning electron microscopic and X-ray microdiffractometeric studies on sialolith-crystals in human submandibular glands.

The crystalline structures of 18 submandibular gland calculi were studied by radiomicrography , scanning electron microscope, and X-ray microdiffractometeric techniques. The following observations were made by SEM: Granular or globular structure was seen on the surface of all cases and pyramidal crystal in one case. In the inside, all showed lamellar pattern with amorphous nucleus in the center, and granular, plate-like and rhombohedral structures were also observed. X-ray microdiffractometeric analyses: Apatite was frequently observed in both outside and inside of the calculi. Whitlockite was next frequently detected and was seen more often in the inside. Brushite and weddellite were noted in the outside of calculi in one case each. Thus, it is suggested that brushite and weddellite were present in the front portion of calculus formation and then transformed into the more stable form e.g. apatite.

Apatites↗
PubMed1983

Fifty years survival after cervical fracture and fusion.

A patient who survived for 50 years after two cervical injuries is described. Among other effects he showed remarkable compensatory changes in the vertebrae above and below a cervical fusion operation. He also developed a meningeal pseudocyst following lumbar laminectomy. The history and pathological findings are considered to be instructive.

Aged↗
PubMed1983

Weddellite in submandibular gland calculus.

Scanning electron microscopy of a submandibular sialolith showed octahedral and dipyramidal crystals located at the surface layer of cortex. The crystal habits observed were consistent with those of a tetragonal crystal system. X-ray microdiffraction revealed the presence of weddellite. The origin of weddellite within the calculus remains to be determined.

Adult↗
PubMed1982

A review of cervical spine injuries with neurological dysfunction.

The authors have studied 193 cases of cervical injury with tetraparesis or paralysis in a similar way to a previous study completed in 1973 (Bedbrook 1973). Comparison with three other centres, Stoke Mandeville, Tokushima and South West Region has shown similarities and regional dissimilarities--for example in aetiology. Only in cases with bilateral facet dislocation was reduction considered to have any effect on neurological recovery in all four geographical areas. The observations recorded strengthen the view that the result of the neurological injury is largely determined at the time of the accident.

Adult↗
PubMed1981

Mode of occurrence of brushite and whitlockite in a sialolith.

A micro-focus X-ray diffractometer was applied to a ground section of sialolith, and localization of brushite and whitlockite was found. The sialolith was composed of a central core of organic material and a layered cortex of mineral components. The major component of the mineral cortex is apatite. Brushite and whitlockite locate independently at the surface layer of the cortex.

Apatites↗
PubMedDate not supplied

Ossification of posterior longitudinal ligaments: evaluation with MRI.

Ossification of the posterior longitudinal ligament is a special subcategory of degenerative disease responsible for compression of the spinal cord. On MR images, T2-weighted sequences are the most effective to evaluate both spinal cord compression due to the ossification and abnormal signal intensity of the cord. Although ossification of the ligaments is well demonstrated on CT and plain radiographs, MRI noninvasively provides useful information about the degree and extent of spinal cord compression, as well as the character of the ossification.

Diagnosis, Differential↗
PubMedDate not supplied

Calcium crystal deposition in cervical ligamentum flavum: CT and MR findings.

We report three patients with calcium pyrophosphate dihydrate crystal deposition disease within the ligamenta flava of the cervical spine who presented with progressive myelopathy. Plain radiography showed oval calcified nodules at the level of C4-C5 and C5-C6. On computed myelography, oval calcified nodules were seen in the ligamenta flava of the posterior cervical spinal canal compressing the dural sac. Magnetic resonance revealed oval corresponding hypointense foci both on T1-and T2-weighted images. In two cases, the cervical cord showed hyperintensity at the compression site on T2-weighted images.

Aged↗