Biomedical subjects
Publications and source records attributed to Y Takagi.
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Though the mechanism of 201Tl accumulation in thyroid tumours is not known yet, there are some hypotheses. In order to study the mechanism, potassium contents and Na, K-ATPase, of various organs of rats and human thyroid glands were analyzed . The conclusion through these experiments is as follows, 1 as the potassium contents and Na, K-ATPase activity of thyroid glands are not obviously higher than those of other organs, the 201Tl accumulation in thyroid is thought to be not owing to the similarity to the potassium ion, 2 pointing out high activity of Na, K-ATPase in heart and kidney, the accumulation mechanism of 201Tl in these organs has high relation to this activity, 3 though there is a tendency to have higher potassium contents among thyroid tumours, the difference in potassium contents between their histopathology is small; so that the tumour specificity is not explained from the potassium contents, and 4 as for Na, K-ATPase activity of thyroid tumours, papillary adenocarcinoma and follicular adenoma, which take more in 201Tl, have tendency to show higher activity; adenomatous goitre, which take less in 201Tl, has tendency to show lower activity. We suggested that the factor relating to the accumulation mechanism of 201Tl may be multiple, and Na, K-ATPase plays an important role in 201Tl specific uptake in thyroid tumours.
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A retrospective study of post-transfusion hepatitis (PTH) has been made of 168 patients who had open-heart surgery between 1978 and 1981 at the Nagasaki University Hospital. The criteria of PTH was defined as an elevation of SGPT over 50 units with more than 2 weeks duration that occurred later than 3 weeks after the transfusion. PTH developed in 27 of the 168 patients (16%) and 26 of them were of the non-A, non-B type. The statistical analysis of these patients demonstrated that the following clinical factors significantly increased the incidence of PTH subsequent to open-heart surgery: (1) Use of plasma fractionating products made from pooled plasma, such as PPSB (p less than 0.001). (2) A large amount of blood and blood component transfusion (over 21 units, p less than 0.01). (3) Prolongation of the operation time (more than 330 minutes, p less than 0.05), cardiopulmonary bypass time (more than 90 minutes, p less than 0.05) and aortic cross-clamping time (more than 45 minutes, p less than 0.01), and (4) Surgery for cardiac lesions with left heart overloads (p less than 0.01).
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To assess a possible mechanism of abnormal interventricular septal motion following cardiac surgery, 16 patients were studied during cardiac surgery by M-mode and two-dimensional echocardiography. All 16 patients underwent open heart surgery using cardiopulmonary bypass. M-mode echocardiogram and short-axis views of the left ventricle by two-dimensional echocardiography were obtained before and after pericardiotomy, and before and after the closure of the pericardium. Interventricular septal motion did not change after pericardiotomy. Interventricular septal motion just after cardiac surgery was variable and dependent on each underlying condition. In all the 16 patients, interventricular septal motion became abnormal after the closure of pericardium. The abnormal septal motion persisted following the chest closure. We conclude that pericardial closure is responsible for post-operative abnormal septal motion.
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Hydroxyapatite crystal deposition and stabilization within the collagen matrix of bone and dentin have been linked to the presence of noncollagenous proteins (NCP). Dentinogenesis imperfecta (DI), a genetic disorder of dentin mineralization, is being studied as a model for the analysis of mineralization mechanisms. A comparative study of the NCP in normal human dentin and dentinogenesis imperfecta Type II (hereditary opalescent dentin) dentin has been performed. The proteins of each tissue were extracted and separated using a variety of techniques. The calcium-binding, highly phosphorylated protein phosphophoryn was one of the principal NCP in normal human teeth dentin, whereas there was no evidence for the presence of such a component in the DI teeth. These data imply that dentin phosphophoryn may be related in function to the mineralization process. A similar calcium-binding protein defect should be sought in the various types of osteogenesis imperfecta.
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The delta-globin genes of a normal Japanese and a Japanese patient with homozygous delta-thalassemia were cloned, and the nucleotide sequence of a region including the gene was determined. Comparison of the nucleotide sequences of these two individuals with that of pH delta 1, delta-globin clone from the gene library constructed by Maniatis et al., showed differences in the large intervening sequence (IVS 2), at positions 137, 151, 186, 188, 291, 292 and 540 as one base substitutions, at 339 and 823 as one base additions, at 548 as a one base deletion, and a 9 bp duplication between positions 651 and 659, and differences in the 3'-flanking sequence at 51 and 98 nucleotides 3' to the AATAAA sequence. However, in the region studied, no differences was observed in the nucleotide sequences of the normal subject and the patient with delta-thalassemia. Therefore, these differences may represent polymorphisms of the delta-globin gene present in Japanese individuals. These data suggest that IVS 2 is more divergent than other regions, and that a DNA region(s) other than the globin gene may affect expression of the gene.