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Biomedical subjects

K Asada

Publications and source records attributed to K Asada.

At least 145 records · Page 8Linked to original sources
PubMed1987

Inactivation of 2-oxoglutarate dehydrogenase in rat liver mitochondria by its substrate and t-butyl hydroperoxide.

Ketoacid oxidation in rat liver mitochondria was very sensitive to t-butyl hydroperoxide (t-BuOOH). Furthermore, 2-oxoglutarate and pyruvate each enhanced t-BuOOH-induced oxidative stresses of mitochondria, such as oxidation of pyridine nucleotides and GSH, inhibition of respiration with the other NAD-linked substrates, and peroxidation of mitochondrial lipids. We provide evidence that the t-BuOOH and ketoacid-induced effects are due to the failure of supply of NADH by 2-oxoglutarate dehydrogenase, and report the inactivation of the dehydrogenase in mitochondria by simultaneous addition of 2-oxoglutarate and t-BuOOH. Using the purified enzyme, we confirmed that t-BuOOH-induced inactivation of 2-oxoglutarate dehydrogenase was enhanced by its substrate and thiamine pyrophosphate protected the dehydrogenase from the inactivation. In contrast, succinate-dependent oxidation of mitochondria was not only scarcely affected by t-BuOOH, but also succinate protected against inactivation of 2-oxoglutarate dehydrogenase by t-BuOOH in mitochondria.

Animals↗
PubMed1987

Development of alumina ceramic bipolar hip prosthesis and clinical application.

The concept of the bipolar type prosthesis is that the articular motion is observed primarily between the HDP bearing insert and the inner head, thereby avoiding the greater frictional shear force between the prosthetic head and acetabulum found with the traditional one piece endoprosthesis. A newly developed ceramic bipolar hip prosthesis utilizes an outer head composed of bio-inert fine alumina ceramic rather than a metal head. The mechanical strength of this prototype bipolar hip prosthesis was tested with static load and impact force, and the dynamic fatigue strength was also tested with repeated loads. Results were judged to show that the device has strength adequate for clinical use. The hip prostheses has been clinically applied in replacement of the femoral head of a neck fracture, femoral head necrosis and osteoarthritic hip. Finally, using a mathematical model, the so-called self-centering effect due to center offset between outer and inner heads is discussed.

Adult↗
PubMed1986

Sizes of Mn-binding sites in spinach thylakoids.

The sizes of the Mn-binding sites in spinach thylakoids were estimated by target size analysis, assaying the membrane-bound Mn that was resistant to EDTA washing after radiation inactivation. The inactivation curve showed well the inactivation of two independent Mn-binding sites of different sizes: about two-thirds of the Mn coordinated to a binding site of 65 kDa, and the rest bound to a much smaller site of only about 3 kDa. In the large site, there was about 1 g atom of Mn/110 mol of chlorophyll in spinach thylakoids, which was constant in normally grown plants, although the Mn level in the small site depended on culture conditions. Thylakoids that had been incubated with hydroxylamine or in 0.8 M Tris lost Mn exclusively from the large binding site.

Binding Sites↗
PubMed1986

Aesthetic considerations of the cleft lip operation.

The results of a cleft lip operation are checked from the anterior, the profile, and the caudal views and even if the deformities are minimal, for aesthetic reasons they should be repaired. Philtrum length, philtrum shape, philtrum depth, nasolabial triangular area, vermilion thickness, Cupid's bow peak, horizontal upper lip groove, vermilion border, alar size, depth of alar groove, nasal deviation, nostril shape, nasal tip, columella height, sill shape, columella width, and facial balance of the anterior, profile, and caudal views are used as aesthetic checkpoints for the results of a cleft lip operation. If deformities are found, the aesthetic plastic surgeon should repair them to achieve a more satisfactory result. In addition, augmentation rhinoplasty, augmentation mentoplasty, or other craniofacial surgery may be performed.

Chin↗