Biomedical subjects
Publications and source records attributed to K Ando.
The relative configuration of the title compound, C(23)H(29)NO(11), prepared in a synthetic study on the natural product sphingofungin E, has been determined. The six-membered ring adopts a chair form and the five substituents are all axial.
The new method of chemical-induced premature chromosome condensation combined with fluorescence in situ hybridization was used to analyze chromosomal damage in peripheral blood mononuclear lymphocytes of patients undergoing radiation treatment for esophageal cancer with high-energy X-rays or accelerated carbon ions at the National Institute of Radiological Sciences (Chiba, Japan). Total number of aberrant cells correlated with radiation field size, but no correlation was found with acute toxicity. A high frequency of complex-type exchanges were also recorded. This aberration type presented a high individual variability, and correlated well with the acute morbidity. Cytogenetic analysis by interphase chromosome painting is proposed as a useful tool for monitoring normal tissue effects during radiotherapy.
To overcome low efficiency of retroviral infection into immature T cells, we modified reaggregation fetal thymus organ culture by closely packed co-culture with virus-producing cells (VPC). The viral vector was constructed in chimeric vector, pMX, with IRES and tailless-rat CD2 as a surface marker of infected cells. A rearranged TCR beta gene (Vbeta8.2) was further inserted into the construct for investigating effect of the introduced gene in T cell development. Using this system, we succeeded to transfer the viral vector into immature thymocytes at a remarkably higher efficiency compared to conventional methods using medium containing retrovirus. Moreover, the introduced TCR beta gene was expressed on thymocytes of RAG2-deficient mice to induce in the transition of CD4-CD8- double-negative (DN) into CD4+CD8+ double-positive (DP) cells by transducing beta-selection signaling. Thus, our modified reaggregation culture system is useful for studying the molecular mechanism of T cell development due to a highly efficient gene transfer into immature T cells.
A high-performance liquid chromatographic method has been developed for the determination of saccharides in sake, an alcoholic beverage brewed from rice. Saccharides in sake were separated on a normal phase (carbamoyl bonded silica) column using a linear gradient elution of water in acetonitrile. Seven saccharides, glucose, maltose, isomaltose, maltotriose, panose, isomaltotriose and ethyl alpha-D-glucoside, were determined by a polarized photometric detector. Unidentified peaks suggesting saccharides with polymerization degrees over 4 were also observed. The proposed method did not require any sample clean-up treatment. As an application, saccharide compositions in various kinds of sake were compared.
The p21(WAF1)induces cell cycle arrest at G(1)and its expression is regulated by the functional p53. TNF-alpha induced expression of p21(WAF1)at protein and mRNA levels in a dose-dependent fashion with an association with G(1)-arrest in human colon cancer cells WiDr that carry mutated p53 at codon 273 (His(273)). However, TNF-alpha did not affect the levels of the Bax protein, which also has p53-binding sites on its promoter and causes apoptosis. Further experiments suggested that cycloheximide (CHX), a protein synthesis inhibitor, increased the levels of p21(WAF1)mRNA and the induction of p21(WAF1)mRNA by TNF-alpha did not require new protein synthesis. Co-transfection of the p53 His(273)expression construct with a luciferase gene controlled by the p21(WAF1)promoter showed that the p53 His(273)was inactive, although TNF-alpha increased the transcriptional rate of p21(WAF1)in these cells. Further study found that TNF-alpha markedly stabilized the p21(WAF1)protein. These findings suggest that TNF-alpha induces expression of p21(WAF1)through a distinct pathway from Bax and that protein stabilization is an important mechanism in the expression of p21(WAF1)independent of p53.
Severe osteoarthritis due to acetabular dysplasia (n = 17) was treated with valgus-extension osteotomy, and the patients' clinical outcomes 10-14 years after operation were evaluated according to clinical factors (Japanese Orthopaedic Association hip score; JOA score) and by roentgenography. The mean JOA score 10 years or later had improved by 22 points compared with the preoperative score. On roentgenography, joints which had preoperative roof osteophyte had better postoperative formation of roof osteophyte. The JOA score was higher in the 12 joints which had osteophyte 5 mm or longer than in those joints with osteophyte that was 5 mm or shorter. Postoperative joint space widening occurred in 15 joints (88.2%) 3-6 months postoperatively, and it reached the maximum at 3-5 years. In patients who had a large bone cyst in the femoral head preoperatively, the cyst collapsed, and deformation of femoral head occurred after operation, but remodeling of the joint surface occurred naturally and the congruity improved. In the 6 joints in which the preoperative acetabular head index was less than 60% and the acetabular angle was larger than 30 degrees, the JOA score at 10 years or later was lower than that of the other joints. Based on these findings, valgus-extension osteotomy was evaluated as a useful surgical method for advanced or terminal osteoarthritis in young or middle-aged patients. Predictive factors for long-term prognosis would be the preoperative length of roof osteophyte, joint space widening, and the degree of femoral head covering.
Dietary restriction (DR) retards physical growth, resulting in small body size, reduced liver weight and reduced number of hepatocytes in rats. We examined the effects of DR on proliferation and apoptosis of hepatocytes during development and explained these changes subcellularly using immunohistochemistry for bromodeoxyuridine (BrdU) incorporation, proliferating cell nuclear antigen (PCNA) and p53, terminal dUTP nick end labeling (TUNEL) and quantitative reverse transcription-polymerase chain reaction (RT-PCR) for TGFalpha, TGFbeta1, p53, Fas and TNF receptor (TNFr). Tissue samples included the livers of 3-month-old male Fischer 344 rats fed ad libitum (AL) or on 70% DR. DR significantly reduced the proportions of BrdU-positive and PCNA-strongly-positive hepatocytes compared with AL rats but not the proportions of PCNA-positive hepatocytes and TUNEL-positive hepatocytes. On the other hand, DR enhanced the expression of p53 and Fas mRNAs but failed to influence the expression of TGFalpha, TGFbeta1 and TNFr mRNAs. Moreover, DR significantly increased the proportion of p53-positive hepatocytes. Our findings suggest that DR suppresses the proliferation of hepatocytes, resulting in a reduced number of hepatocytes during development. This process may be mediated by overexpression of p53 suppressor gene. While DR accelerates the expression of Fas antigen, this result does not influence the rate of apoptosis of hepatocytes under physiological conditions.
During the period from December 1980, when we began using Ender nails for the treatment of tibial shaft fractures, to December 1995, 274 unions of 280 fractures in 275 patients treated by Ender nailing were successfully achieved. Ender nailing for tibial shaft fractures can be classified into three methods A, B, and C, according to the insertion points of the nails. In method A, which is used for the proximal one-third fractures of the tibia, the nails are inserted from the distal tibia medially and laterally towards the proximal tibia. In method B, which is for middle or distal one-third fractures of the tibia, the nails are inserted from the proximal tibia medially and laterally directed distally. In method C, which is for long oblique or double fractures, one nail is inserted from a proximal site, and the other is inserted distally; these two nails must form an X-shape. Ender nailing is an excellent semiconservative treatment for tibial shaft fractures, maintaining adequate elasticity at the fracture sites where much callus is formed, leading to a good union.
The present study was undertaken in order to reexamine the effect of n-3 polyunsaturated fatty acid (PUFA)-rich diet supplementation on lipid peroxidation and vitamin E status of rat organs. Male Wistar rats were fed a diet containing safflower or fish oil at 50 g/kg diet and an equal amount of vitamin E at 59 mg/kg diet (1.18 g/kg oil; and 1.5 g/kg PUFA in safflower oil diet, and 4.3 g/kg PUFA in fish oil diet) for 6 wk. Fatty acid composition of total lipids of brain, liver, heart, and lung of rats fed fish oil was rich in n-3 PUFA, whereas that of each organ of rats fed safflower oil was rich in n-6 PUFA. The vitamin E levels in liver, stomach, and testis of the fish oil diet group were slightly lower than those of the safflower oil diet group, but the levels in brain, heart, lung, kidney, and spleen were not different between the two diet groups. The levels of phospholipid hydroperoxides were determined by the high-performance liquid chromatography-chemiluminescence method and the levels of thiobarbituric acid-reactive substances (TBARS) were determined at pH 3.5 in the presence of butylated hydroxytoluene with or without EDTA. Levels of phospholipid hydroperoxides and TBARS in the brain, liver, heart, lung, kidney, spleen, stomach and testis of the fish oil diet group were similar to those of the safflower oil diet group. The results indicate that high fish oil intake does not induce increased levels of phospholipid hydroperoxides and TBARS in rat organs.
We report here a case of refractory anemia with ringed sideroblasts (RARS) with a low risk group by the International Prognostic Scoring System (IPSS) at the time of diagnosis but had a rapid disease progression. Although the patient showed a normal male karyotype at the time of RARS diagnosis, his marrow cells had del(5)(q14) and add(17)(p12) abnormalities 2 months after the diagnosis, and later the marrow cells had multiple abnormalities and the patient expired 6 months after the initial diagnosis of RARS. The patient was diagnosed as having RARS with a low risk group by the IPSS classification, however, one should keep in mind that some patients with myelodysplastic syndromes with low risks by either the French-American-British (FAB) classification or the IPSS classification may have progressive disease and subsequential cytogenetic analysis could predict the disease progression.
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Primary mixed cultures of astrocytes and microglia were obtained from neonatal mice, and were irradiated with high-LET carbon ions. Immunohistochemical staining showed astrocytes survived more prominently than microglia. Tagged with specific antibodies, astrocytes and microglia surviving after irradiation were counted by flow cytometry. Decreases in the number of microglia and astrocytes were detected at a dose as small as 2 Gy when Day 5 cultures were irradiated with 13 keV/micrometer carbon ions. When the cultures were irradiated on Day 10, the dose-dependent decrease of microglia was more prominent for 13 keV/micrometer carbon ions than 70 keV/micrometer carbon ions. Astrocytes showed a marginal decrease at Day 10 and Day 14. We concluded that microglia are more sensitive than astrocytes to carbon ions and X-rays, and that the radiosensitivity of microglia depends on both differentiation/proliferation status and radiation quality.
Human CD34(-) hematopoietic stem cells (HSCs) have been identified as potential precursors of CD34(+) HSCs by using xenogeneic transplantation systems. However, the properties of CD34(+) cells generated from CD34(-) cells have not been precisely analyzed due to the lack of an in vitro system in which CD34(+) cells are continuously produced from CD34(-) cells. We conducted this study to determine whether CD34(+) cells generated in vitro from CD34(-) cells have long-term multilineage reconstitution abilities. Lin(-)CD34(-) population isolated from human cord blood was cultured in the presence of murine bone marrow stroma cell line, HESS-5, and human cytokines, thrombopoietin, Flk2/Flt3 ligand, stem cell factor, granulocyte colony-stimulating factor, interleukin 3 (IL-3), and IL-6. They were analyzed weekly for their surface markers expressions, colony-forming cells, long-term culture initiating cells (LTC-IC), and SCID repopulating cells (SRC) abilities up to 30 days of culture. In this culture system, more than 10(7) CD34(+) cells can be continuously generated from 10(4) CD34(-) cells over 30 days. These CD34(+) cells produce colony-forming units, LTC-IC, and SRC with multi-lineage differentiation, all of which are characteristic features of hematopoietic stem/progenitor cells. These findings suggest that CD34(-) HSCs have extensive potential for the generation of CD34(+) HSCs in vitro. This system provides a novel and potentially useful procedure to generate CD34(+) cells for clinical transplantation and gene therapy.
Walker-Warburg syndrome (WWS) is an autosomal recessive disorder characterized by type II lissencephaly, cerebellar and retinal anomalies, and congenital muscular dystrophy. We report a female diagnosed with WWS based on clinical criteria. This patient was found to have fetal hydrocephalus on ultrasonography at 29 weeks of gestation, and exhibited severe hypotonia, ocular malformations, and hydrocephalus at birth. MRI revealed type II lissencephaly, hydrocephalus, and other severe brain malformations. Genetic analysis was performed to distinguish WWS from severe Fukuyama-type congenital muscular dystrophy (FCMD), which has numerous findings in common. This revealed no expression of the founder haplotype or single-stranded conformation polymorphism (SSCP) abnormalities. Since the life expectancy of patients with FCMD is longer, differential diagnosis should be performed precisely.
Utilizing the experimental model in Syrian golden hamsters, we explored the role of immunization in carcinogenesis. The animals, which were infected with liver flukes (Opisthorchis viverrini), and administered a subcarcinogenic dose of dimethylnitrosamine, developed cancer. Pre-immunizing with a crude somatic antigen did not reduce cancer development, but accelerated carcinogenesis. Histopathological analysis of the cancer tissues was done once at week 30 and again at week 39 using H and E staining, immunostaining for the p53 tumor suppressor phosphoprotein, and electron microscopy. Thirty weeks after immunization, the immunized hamsters developed tubular adenocarcinoma at a higher rate (71.43%) than the non-immunized group (20.00%). This rate (20.00%) increased to 63.64% by week 39. The small foci cancer in the non-immunized group decreased in frequency from 80.00% (at week 30) to 36.36% (by week 39), suggesting the small foci cancer progressed to tubular adenocarcinoma during the 9-week interval. Most of the observed tubular adenocarcinoma was well differentiated. Nearly all hamsters that tested positive for cancer also tested positive for p53 immunostaining in the epithelia of the small bile ducts. The positive reaction for p53-immunostaining was localized in the rough endoplasmic reticulum, Golgi apparatus and perinuclear membranes. The electron micrographs of these positive p53-immunostained cells showed characteristics of early cancer. The detection of p53 in early cancer development makes it a candidate as a tumor marker.
Recent studies have demonstrated the presence of human lineage- (lin-)CD34- cells that are capable of differentiating into CD34+ cells in xenogeneic transplantation systems. We developed a new filter system that can enrich lin-CD34- cells, a precursor cell population of CD34+ cells. The filter consists of polyethylene terephthalate non-woven fabrics coated with hydrophilic polymer. The frequency of lin-CD34- cells in the cell population after filtration was 7.45 +/- 4.41%, a 16.8 +/- 8.81-fold enrichment compared with 0. 49 +/- 0.31% in the cell population before filtration. The mean recovery of lin-CD34- cells was 48.57 +/- 13.59% (n = 15). Purified lin-CD34- cells, obtained by sorting the filtrated cell population, acquired CD34 expression and colony-forming activity after 7 d of culture. Our results indicate that this filter system is useful for isolating lin-CD34- cells, including precursors of CD34+ cells, and will help further the study of lin-CD34- cells.
Haemangioma of the oesophagus is uncommon in patients with benign oesophageal tumours. We present a patient with an oesophageal haemangioma detected during mass screening of the upper gastrointestinal tract. The patient, a 59-year-old man, had neither abdominal complaints nor a history of gastrointestinal diseases. Endoscopic examination revealed a blue-coloured submucosal tumour (approximately 3 cm in diameter) at the middle portion of oesophagus. Endoscopic Doppler ultrasonography showed an homogeneous and hypoechoic mass without blood flow in the submucosal layer of the oesophagus. However, a magnetic resonance imaging scan did not give a typical image for oesophageal haemangioma. Therefore, partial resection of the tumour was performed to obtain a differential diagnosis using the procedures of endoscopic ligation and polypectomy. Histological examination of the resected tissue showed a cavernous haemangioma in the oesophagus. This endoscopic technique may be useful for the differential diagnosis of oesophageal haemangioma.
The mature form of Alzheimer's beta-amyloid precursor protein (APP) is phosphorylated specifically at Thr(668) in neurons. In mature neurons, phosphorylated APP is detected in neurites, with dephosphorylated APP being found mostly in the cell body. In vitro, active cyclin-dependent kinase 5 (Cdk5) phosphorylated the cytoplasmic domain of APP at Thr(668). Treatment of mature neurons with an antisense oligonucleotide to Cdk5 suppressed Cdk5 expression and significantly diminished the level of phosphorylated APP. The expression of APP was unaffected in antisense-treated neurons. These results indicate that in neurons APP is phosphorylated by Cdk5, and that this may play a role in its localization.