Biomedical subjects
Publications and source records attributed to M Terauchi.
A new 200 kV Omega-filter electron microscope was developed under a project supported by a Grant-in-Aid for Specially Promoted Research of the Ministry of Education, Science, Sports and Culture of Japan. The performance of the microscope is described.
We have developed a high energy resolution electron energy-loss spectroscopy (EELS) microscope, which can take spectra from specified small specimen areas and specified small reciprocal space areas to investigate detailed electronic structures. The EELS microscope is equipped with retarding Wien filters as the monochromator and the analyser. The filters are designed to achieve a stigmatic focus. The energy resolutions are 12 meV and 25 meV for cases without and with a specimen, respectively. Spatial and momentum resolutions are 30-110 nm in diameter and 1.1 nm-1 in angular diameter, respectively. EELS spectra are presented to show the performance of this instrument.
Susceptibility to insulin-dependent diabetes mellitus (IDDM) is determined by both environmental and genetic factors. The main gene associated with predisposition to IDDM is HLA. Recent studies have described linkage and association of IDDM to the CTLA-4 gene (IDDM12) in Caucasians. CTLA-4 is a candidate gene for T-cell-mediated autoimmune diseases because it is a negative regulator of T-cell proliferation. We investigated the distribution of a CTLA-4 gene polymorphism in 110 Japanese patients with IDDM and 200 control subjects. In 84 patients, we also investigated associations between this CTLA-4 gene polymorphism and GAD65 antibody positivity. An A/G transition at position 49 of exon 1 was analyzed by the polymerase chain reaction-restriction fragment length polymorphism method. GAD65 antibody was detected using a radioligand binding assay. There was no significant difference in the distribution of CTLA-4 alleles in patients and controls and no difference was observed in prevalence of CTLA-4 alleles when GAD65 antibody-positive and -negative individuals in the IDDM groups were compared. The present study did not support an association between the CTLA-4 gene and IDDM in the Japanese population.
PURPOSE: Although median raphe cysts of the penis have been widely reported the pathogenesis is obscure. We describe the microstructural detection of 3 cases of median raphe to study the true pathogenesis. MATERIALS AND METHODS: Three patients presented to our clinic of plastic surgery complaining of abnormal shape of the penis or mass recurrence. High magnification light microscopy and electron microscopy were performed. RESULTS: Microstructural study revealed that all 3 cases had similar findings to those of the common urethral mucosa. CONCLUSIONS: Median raphe cysts are derived from the external paraurethral ducts and contain features that to our knowledge have not been previously reported.
We studied 37 patients with varus osteoarthritis of the knee to determine the influence of the bone mineral density (BMD) on the varus deformity. There were 15 men (21 knees) and 22 women (38 knees). The mean age of the men was 69 years and of the women 68 years. BMD was measured in the L1-L4 spinal region using dual X-ray absorptiometry. In the women a low level of BMD was associated with varus deformity originating at the proximal tibia, but a high level was predominantly linked with deformity originating in the joint space. Similar findings were obtained in the men. Our results suggest that a low BMD predisposes to trabecular microfractures and consequently increased stress on the articular cartilage. A low BMD does not preclude osteoarthritic change in the knee.
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Arthroscopy was performed on 53 consecutive patients with acutely torn ACL within two weeks after the initial injury. Arthrography was performed on 42 of the 53 patients prior to arthroscopy. Four Segond's fractures, twenty-six meniscus tears (eight medial, eighteen lateral) and nineteen medial collateral ligament (MCL) ruptures were revealed. One medial meniscectomy was performed under arthroscopy, and ten MCL tears were repaired in the acute phase. No surgical procedure was done on the torn ACL, but three excisions of ACL stubs were performed due to a restriction of full extension. The patients were re-examined clinically and radiographically after a period of from 3 years 7 months to 11 years 1 month, averaging 6 years 2 months. Four late meniscectomies were performed on the medial menisci in the chronic phase. Anterior translations of the tibia and knee rating scores of the patients with MCL tears and with Segond's fractures did not differ from those of the others. Anterior translations of the tibia in patients with medial meniscectomies increased (P < 0.05), and their functional scores significantly decreased (P < 0.01) more than those of the other patients. Patients with repaired MCL tears showed significantly higher functional scores than those of the patients with unrepaired MCL ruptures (P < 0.05).
Lower limb alignment of 46 knees treated with high tibial osteotomy was studied to find a method for determining the precise correction angle. The femorotibial angle was divided into several axial alignment parameters. Before the operations, the femorotibial angle correlated with the tilting angle of the femoral shaft toward the horizontal (femoral shaft-horizontal angle) and that of the tibial shaft toward the horizontal (tibial shaft-horizontal angle). After the operations, the femorotibial angle correlated with the tibial shaft-horizontal angle, but not with the femoral shaft-horizontal angle. The postoperative femoral shaft-horizontal angle tends to be constant regardless of the degree of valgus. In preoperative varus knees, the varus deformity increases the degree of shift of the femoral and tibial shaft toward the varus direction. In postoperative valgus knees, the more valgus the knee the more the tibial shaft shifted toward the valgus direction, which was not true for the femoral shaft. The femorotibial angle was influenced more by the tibial axial alignment in the postoperative valgus knee. The slope of the distal femoral articular surface influenced the tilt of tibial articular surface toward the horizontal which, in turn, influenced the tibial shaft-horizontal angle. The authors recommend relying on the tibial axial alignment parameter to determine the amount of correction. The slope of the distal femoral articular surface should be considered in preoperative planning.
A followup study was performed to elucidate the natural course of acutely torn anterior cruciate ligaments in recreational athletes. Fifty-six consecutive patients had arthroscopy within 2 weeks of their initial injuries; however, no surgery was done on the torn anterior cruciate ligament. Twenty anterior cruciate ligament and medial collateral ligament combined ruptures occurred. Patient ages ranged from 14 to 50 years old (mean, 28.9 years). Followup periods ranged from 2 to 10 years (mean, 5 years 6 months). Through examination with the KT-1000 arthrometer, side-to-side differences of anterior translation of the tibia of > or = 3 mm in 72% patients at reexamination were seen. Eight of 46 patients had mild osteoarthritic changes of Grade 1 visible on radiographs, but only 1 patient reported knee trouble. Nine patients had repeat injuries, 3 of whom had late reconstructions and 4 late meniscectomies. Functional scores averaged 95 +/- 6.5 points. Activity scores averaged 4.8 +/- 1.6 points. Operative management for the medial structure did not improve the stability better than nonoperative management. Anterior translation and functional scores of patients with medial meniscectomies showed significant differences from those of other patients. Anterior cruciate ligament reconstruction for recreational athletes should be considered when the patients have reparable meniscal tears, and meniscal repairs should be performed simultaneously.
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The radial artery runs between the Flexor Carpi Radialis tendon and the Brachioradialis tendon in the distal one-third of the forearm. Here it is covered only by the superficial fascia, subcutaneous tissue and skin, so that it is easy to palpate. However, the case reported here describes a rare anomaly of the radial artery which has relevance to use of the forearm flap.
As a continuation of the study on the biological roles of furan fatty acids (F acids) which are still vague, their inhibitory effects on the hemolysis of erythrocytes induced by singlet oxygen were examined. Hemolysis proceeded smoothly in the absence of F acids, but was suppressed significantly and dose dependently in their presence. No significant differences in inhibitory effects on the hemolysis induced by singlet oxygen between tetra-alkylsubstituted F acid (F3) and di-alkylsubstituted F acid (NMF) could be detected. The acids underwent oxidation to give the corresponding diketo-enes, indicating a reaction with singlet oxygen to suppress hemolysis. The inhibitory effects of F acids on hemolysis were compared with those of known singlet oxygen quenchers such as dimethylfuran, alpha-tocopherol, ascorbic acid and uric acid and F acids were found to be the most effective quenchers.
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Retinoblastoma (Rb) occurs in hereditary, non-hereditary, and chromosomal deletion forms and the locus for the Rb gene (Rb-1) is closely linked to the locus for esterase D (ESD) assigned to the chromosome 13q14.11. We describe a patient who was predicted to have Rb from the genetic analysis of the chromosome and ESD phenotype. Furthermore, the gene for lymphocyte cytosol polypeptide with molecular weight of 64,000 (LCP1: McKusick catalogue No. 15343, 1983) was assigned to chromosome 13 by deletion mapping. A 3-month-old female had many characteristics of chromosome 13q-syndrome, including dolichocephaly, epicanthus, ptosis, depressed nasal bridge, micrognathia, short webbed neck, and short fifth fingers with clinodactyly and single crease. The karyotype of the patient was 46,XX,del(13) (q14.1-q32), though both the parents had normal karyotypes. As expected, the phenotype of ESD derived from one of the parents, the father in this case, was not detected in peripheral blood lymphocytes by two-dimensional gel electrophoresis (two-DE), indicating that ESD from the father was deleted in the abnormal chromosome 13. The possibility of paternity was calculated to be 0.996 based on the data using 22 genetic markers. Bilateral retinoblastomas could be diagnosed by ophthalmologic examinations before the manifestation of any clinical signs of the tumor and immediately intensive care was taken. In addition, the phenotype of LCP1 derived from the father was not expressed in the lymphocyte proteins from the patient. These data indicate that the gene for LCP1 (LCP1) is located in the region q14.1-q32 of chromosome 13 and may be a useful genetic marker for preclinical diagnosis of Rb.
The function of Mn(III) in plant acid phosphatase has been investigated by a metal-substitution study, and some properties of the Fe(III)-substituted enzyme were compared with those of the native Mn(III) enzyme and mammalian Fe(III)-containing acid phosphatases. 19F nuclear magnetic resonance (NMR) and proton relaxation rate measurements showed that inhibitors such as F- and nitrilotriacetic acid interact with paramagnetic Mn(III) active site. The 31P-NMR signal of the enzyme-phosphate complex was also broadened by the paramagnetic effect of Mn(III). In the metal-substitution experiments of the Mn(III)-acid phosphatase with Fe(III), Zn(II) and Cu(II), only the iron gave satisfactory substitution. The Fe(III)-substituted plant acid phosphatase exhibited an absorption maximum at 525 nm (epsilon = 3000), typical high-spin ferric ESR signal at g = 4.39, and lower pH optimum (pH 4.8) than the native Mn(III)-enzyme (pH 5.8). The phosphatase activity of the Fe(III)-substituted enzyme was reduced to about 53% of that of the native enzyme. The substrate specificities of both metallophosphatases were remarkably similar, but different from that of the Fe(III)-containing uteroferrin. The present results indicate that Mn(III) and Fe(III) in the acid phosphatase play an important role on effective binding of phosphate and acceleration of hydrolysis of phosphomonoesters at pH 4-6.
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The metabolism of benzo(a)pyrene (BP) in epidermal keratinocytes and dermal fibroblasts of humans and mice was investigated with emphasis on variation among species, individuals, and cell types. Human epidermal and dermal cells were isolated from the skin of normal subjects by trypsinization at 4 degrees overnight, followed by separation of the epidermis from the dermis with forceps. In confirmation of previous studies metabolic activity of human epidermal cells on BP was consistently demonstrated by cell-mediated assay, in which V79 Chinese hamster cells were plated on top of sheets of epidermal cells and treated with BP for 48 hr. Mutation of the V79 cells, measured as ouabain resistance, was induced in a dose-related fashion, although the extent of induced mutation varied from 5 to 22 ouabain-resistant colonies per 10(6) survivors/10 microM BP in cultures derived from different individuals. The most striking observation was that human dermal fibroblasts did not activate BP to a form that was mutagenic to cocultured V79 cells. This was observed without exception in all nine cultures of dermal fibroblasts and the one culture of embryo fibroblasts (MR-90) tested. Analysis by high-pressure liquid chromatography indicated that human epidermal and dermal cells both metabolized BP, producing almost the whole series of known metabolites of BP. The amount of BP 7, 8-dihydrodiol, a proximate metabolite of BP, produced by human dermal cells varied from 0.2 to 2.7% of the total BP added and seemed to be enough to induce mutation. Furthermore, human dermal cells not necessarily activated exogenously added BP 7,8-dihydrodiol to a form being mutagenic to V79 cells. These observations suggest that further metabolism of BP 7,8-dihydrodiol is partially or entirely blocked in human fibroblasts. In contrast to human fibroblasts, mouse fibroblasts isolated from the dermis of embryos did activate BP and induced mutation in cocultured V79 cells to a higher extent than did mouse epidermal cells, indicating interspecies variation in metabolic activation of BP between human and mouse fibroblasts.
A large subcutaneous mass was noted in the buttock of a 79-year-old man. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a thin-walled cystic mass that involved the ischiorectal fossa. The content appeared hyperintense on T1-weighted images. T2-weighted images demonstrated a considerable amount of debris. At surgery an epidermal cyst with markedly keratinized squamous epithelium was found. It contained much keratin and cholesterin.