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Biomedical subjects

N Takeda

Publications and source records attributed to N Takeda.

At least 217 records · Page 12Linked to original sources

Analysis of IFN-gamma-induced cell cycle arrest and cell death in hepatocytes.

The mechanism by which IFN-gamma induces cell cycle arrest and cell death in primary cultured hepatocytes was examined. The cell death exhibits apoptotic characters such as the appearance of apoptotic bodies and DNA fragmentation. IFN-gamma induced cell cycle arrest at the initial stage, followed by cell death. A protein synthesis inhibitor, cycloheximide, significantly inhibited cell death, implying that IFN-gamma induces de novo proteins involved in the death of hepatocytes. One of the most important apoptosis-related proteins, p53, was induced by IFN-gamma in hepatocytes in a dose- and time-dependent manner. Northern blot analysis demonstrated that IFN-gamma enhanced p53 mRNA expression as well as p21(WAF1/Cip1/Sdi1) mRNA expression, which is mediated by the increased expression of the p53 protein. Interestingly, IFN-gamma also induced cell death in p53-deficient hepatocytes. The cell death occurred rather earlier in p53-deficient cells than in normal hepatocytes. However, the cell death was not accompanied by apoptotic bodies. Therefore, IFN-gamma-induced hepatocyte cell death is p53-independent, and p53 may contribute to the apoptotic characters. In conclusion, IFN-gamma is supposed to cause cell cycle arrest by inducing p53 and p21(WAF1/Cip1/Sdi1), and it was demonstrated that IFN-gamma induces p53-independent cell death in primary cultured hepatocytes.

Animals↗

Pelvic reconstruction with a free fillet lower leg flap.

The free fillet lower leg flap was applied for immediate reconstruction after hemipelvectomy including the overlying soft tissue and the internal and external iliac vessels. The flap, harvested from the amputated lower extremity, is a versatile reconstructive technique for such a large pelvic defect.

Amputation, Surgical↗

Pelvic ring reconstruction with a vascularized bone flap of femur.

We have used a vascularized bone flap of femur for pelvic ring reconstruction after tumor resection in which amputation of the lower extremity was required. The vascularized femoral graft is an alternative technique in restoration of pelvic ring continuity with vascularized bone autografts.

Adult↗

Case report: right-sided periadrenal metastasis supplied by the hepatic artery. Clue to the genesis of pedunculated hepatocellular carcinoma.

The adrenal is the second most common site of haematogenous metastasis of hepatocellular carcinoma (HCC). The right adrenal is much more frequently affected than the left, but no reason has been offered for this difference. An aetiological connection has never been suggested between adrenal metastasis and pedunculated HCC. Hepatocellular carcinoma was resected in two patients who subsequently developed right-sided adrenal metastasis diagnosed by imaging. The adrenal mass was enhanced by hepatic arteriography and took up lipiodol injected into the hepatic artery. Reoperation was performed to remove the adrenal mass, which was abutting on the liver but was readily separable. Histopathologically, the adrenal gland was compressed by a metastatic HCC that developed in the immediate periadrenal tissue or adrenal capsule. By conventional imaging, the adrenal gland could not be recognized and the mass was thought to have arisen within the adrenal gland. In conclusion, periadrenal growth of HCC is a hitherto unrecognized type of metastasis and must have been mistaken either for an adrenal metastasis or a pedunculated HCC in the past. If left unresected, it would have fused with the liver and grown into a pedunculated HCC. Cancer cell invasion through an adrenohepatic fusion is the most likely mode of periadrenal metastasis; it explains the arterial communication between the mass and the liver.

Adrenal Gland Neoplasms↗

A case of Kawasaki disease with coronary artery aneurysms documenting Yersinia pseudotuberculosis infection.

A case of a 5-year-old boy who fulfilled all the criteria for Kawasaki disease (KD) was described. He had associated bilateral coronary artery aneurysms. Our study revealed the isolation of Yersinia pseudotuberculosis in stool cultures, and the elevation and seroconversion of the agglutination antibody titres, and hence he was diagnosed as Y. pseudotuberculosis infection-positive. We also demonstrated the positive mitogenic activity of the culture supernatant of the isolated bacterium from the patient and detected Y. pseudotuberculosis-derived mitogen by PCR. This case therefore suggests that Y. pseudotuberculosis might be closely related to the cause of KD.

Angiography↗

[Serotype determination of enteroviruses that cause hand-foot-mouth disease; identification of enterovirus 71 and coxsackievirus A16 from clinical specimens by using specific probe].

Coxsackievirus A16 (CA16) and enterovirus 71 (EV71) are known to be major causative agents of hand-foot-and-mouth disease prevalent in summer in Japan. Discrimination and identification of these viruses were often hampered by a nonneutralizable or nontypable virus. Therefore, a Southern blot hybridization that utilizes mixed probes specific to serotype was developed. Firstly, an approximately 650 bases spanning 5'-noncoding region to one third of VP2 including entire VP4 was amplified with a set of primers containing enterovirus common sequences and a genomic RNA as template. Secondary, the nucleotide sequences were determined using seven CA16 and eighteen EV71 strains including the standard strains, and the deduced amino acid sequences of VP4 were searched to find residues which are conserved in the same serotypes but diverged among different serotypes. Candidate positions for the mixed probes were defined at the carboxyl terminus of VP4. Thirdly, Southern blot analyses were carried out using thirty-nine enterovirus standard strains, seven CA16 isolates and sixty-six EV71 isolates previously identified by the neutralization test. The results revealed that each mixed probe exclusively bound to the homologous DNAs but not to the heterologous ones. In an attempt to determine serotypes without virus isolation, clinical specimens from hand-foot-and-mouth disease were examined. Of 78 throat swabs and 15 vesicular fluids, 71 (91.0%) and 13 (86.7%) specimens were clearly identified, indicating that the method described here offer advantages over the traditional neutralization assay: It is rapid, specific and less labor-consuming.

Amino Acid Sequence↗

Expression and self-assembly of empty virus-like particles of hepatitis E virus.

Hepatitis E virus (HEV) is a pathogenic agent that causes fecally-orally transmitted acute hepatitis. The genome, a single-stranded positive-sense RNA, encodes three forward open reading frames (ORFs), in which an approximately 2-kb structural protein is located in the 3' end. To produce HEV-like particles the structural protein, with its N terminus truncated (amino acid residues 112 to 660 of ORF2), was expressed in insect Tn5 cells by a recombinant baculovirus. In addition to the primary translation product with a molecular mass of 58 kDa, a large amount of a further-processed molecule with a molecular mass of 50 kDa was generated and efficiently released into the culture medium. Electron microscopic observation of the culture medium revealed that the 50-kDa protein self-assembled to form empty virus-like particles (VLPs). The buoyant density of the VLPs in CsCl was 1.285 g/cm3 and their diameter was 23.7 nm, a little smaller than the 27 nm of native HEV particles secreted into the bile or stools of experimentally infected monkeys. The yield of the VLPs was 1 mg per 10(7) cells as a purified form. The particles possess antigenicity similar to that of authentic HEV particles and, consequently, they appear to be a good antigen for the sensitive detection of HEV-specific immunoglobulin G (IgG) and IgM antibodies. Furthermore, the VLP may be the most promising candidate yet for an HEV vaccine, owing to its potent immunogenicity.

Animals↗

Human immunodeficiency virus type 2 envelope glycoprotein binds to CD8 as well as to CD4 molecules on human T cells.

We report here that human immunodeficiency virus type 2 (HIV-2) envelope glycoprotein (gp105), but not HIV-1 gp120, can bind to CD8 molecules as well as to CD4 molecules on human T cells. This phenomenon may lead to differences in the life cycles of HIV-1 and HIV-2, and it may be related to the differences in disease manifestations of HIV-1 and HIV-2 infection, including longer survival of HIV-2-infected patients.

CD4 Antigens↗

Emx1 and Emx2 functions in development of dorsal telencephalon.

The genes Emx1 and Emx2 are mouse cognates of a Drosophila head gap gene, empty spiracles, and their expression patterns have suggested their involvement in regional patterning of the forebrain. To define their functions we introduced mutations into these loci. The newborn Emx2 mutants displayed defects in archipallium structures that are believed to play essential roles in learning, memory and behavior: the dentate gyrus was missing, and the hippocampus and medial limbic cortex were greatly reduced in size. In contrast, defects were subtle in adult Emx1 mutant brain. In the early developing Emx2 mutant forebrain, the evagination of cerebral hemispheres was reduced and the roof between the hemispheres was expanded, suggesting the lateral shift of its boundary. Defects were not apparent, however, in the region where Emx1 expression overlaps that of Emx2, nor was any defect found in the early embryonic forebrain caused by mutation of the Emx1 gene, of which expression principally occurs within the Emx2-positive region. Emx2 most likely delineates the palliochoroidal boundary in the absence of Emx1 expression during early dorsal forebrain patterning. In the more lateral region of telencephalon, Emx2-deficiency may be compensated for by Emx1 and vice versa. Phenotypes of newborn brains also suggest that these genes function in neurogenesis corresponding to their later expressions.

Animals↗

Cis-acting elements conserved between mouse and pufferfish Otx2 genes govern the expression in mesencephalic neural crest cells.

Previous studies suggested that the Otx2 gene plays an essential role in the development of cranial skeletons and nerves of mesencephalic neural crest origin. To clarify this role, we have identified the cis-acting elements in mouse and pufferfish Otx2 genes responsible for the expression in the crest cells using a transgenic approach with the lacZ reporter gene. In mouse, 49 bp sequences in the proximal 5' region upstream were essential and sufficient to direct the transgene expression in the cephalic mesenchyme. In pufferfish, the 1.1 kb distal region, located far downstream (from +14.4 to +15.5 kb), had almost identical activity. Between them, several DNA sequences were conserved, and mutational analyses indicated that motif A was critical for the transgene expression in the premandibular region while motif B was critical in both premandibular and mandibular regions. Motif B, CTAATTA, contains the core motif for binding of homeodomain proteins while motif A, TAAATCTG, does not match any known consensus binding sequences for transcriptional factors. The cephalic mesenchyme that expressed beta-galactosidase under these cis-elements is most likely to correspond to mesencephalic crest cells. Thus the molecular machinery regulating Otx2 expression in these cells appears to be conserved between mouse and fish, implying a crucial role of the Otx2 gene in development of the neural-crest-derived structures of the gnathostome rostral head.

Animals↗

[A study of health behavior of the elderly without occupation--correlation between participation in health examinations and health behavior].

A survey on the health behavior of inhabitants without occupations, aged 60 or over who lived in city A in Kagawa prefecture (400 people), was performed. The results are summarized as follows: 1. The rates of participation in the general health checkup and the screening for colon cancer were high. In females, significant correlations were observed between the rates of participation in health examinations/screenings and age, but they were not significant in males. 2. The rates of good health practices were high in the items "Taking breakfast", "No change of body weight", "Sleeping adequately" and "Drinking moderately or no drinking". The rate of "Exercise" for males was higher than for females, and the rate of "No smoking" was lower for males than for females. For females, a correlation was observed between the score of good health practices and age, and this score decreased with age, but in males there was no significant difference. 3. The rate of participation in health education or health consultation was about 40 percent, and the rate of participation was larger for female inhabitants than for male inhabitants. 4. Persons who participated in the health examinations/screenings had more healthful practices than who did not participate. A correlation was observed between the rates of participation in health examinations/screenings and "Exercise." 5. Persons who participated in health education or health consultation had more healthful practices than who did not participate. 6. Correlations were observed between the rates of participation in health examinations/screenings and the rate of participation in the health education, or health itself. In this analyzed sample population, the health behavior of primary prevention and secondary prevention were related to each other, and the existence of common factors among health behavior for primary prevention and secondary prevention was estimated. Differences were observed between males and females concerning correlations between health behavior and age. It is thus necessary to improve health behavior via a continuous approach to the lifestyle for women. We think that good health behavior which continues over a long period of time can be instilled by approaching the lifestyle at the time of retirement for men.

Adult↗

[Clinical features and utricular dysfunction in patients with benign paroxysmal positional vertigo].

We report the clinical features in patients with benign paroxysmal positional vertigo (BPPV), who met the following criteria; (1) a history of brief episodes of positional vertigo, and (2) a characteristic torsional paroxysmal positional nystagmus that was observed visually. The mean age of onset was 55 years. There was no sex predominance. In most patients, positional vertigo disappeared within 2 months. We then used the eccentric rotatory test to examine the patients otolithic function. In the eccentric rotatory test, a patient is rotated around an axis located behind his head (eccentric rotation, ECR). We have demonstrated that the enhancement of vestibulo-ocular reflex (VOR) gain in ECR can be used as an index of the utricular function. Enhancement of VOR gain was observed in ECR to the lower ear in positional vertigo, but not to the uppermost ear. The findings suggest an imbalance in utricular function in patients with BPPV. Otoconia dislodged from the deranged utricle may be a source of canalolithiasis/cupulolithiasis.

Adult↗

[A 29-year-old man with diabetes insipidus and cerebellar ataxia and development of spinal cord swelling 15 years after the onset].

We report a 29-year-old man with diabetes insipidus and cerebellar ataxia who developed spinal cord swelling 15 years after the onset. He was well until 14 years of the age when he noted dizziness. Two years after there was an onset of gait disturbance and slurred speech. He also noted polydipsia and polyuria. He was evaluated at the neurosurgery service of our hospital when he was 17 years of the age. Neurologic examination at that time revealed memory loss, horizontal nystagmus, cerebellar ataxic gait, dysmetria and decomposition more on the left. Cranial CT scan revealed a mass lesion involving the left subthalamic region and the head of the caudate area. Spinal fluid was unremarkable, however, human chorionic gonadotropin was increased to 27 mIU/ml. He was treated by radiation therapy (3,000 rads for total brain area and 5,460 rads for focal region). His CT scan and memory loss improved, however, cerebellar ataxia was unchanged. Three years after the radiation, he started to show choreic movement in his neck and left upper extremity. He was admitted to our service in August 14, 1995 when he was 29 years of the age. On admission, he was alert but disoriented to time; calculation was also poor. Higher cerebral functions were intact. The optic fundi were normal without papilledema. Visual field appeared intact. Gaze nystagmus was observed in all the directions, but more prominent in the horizontal direction. Speech was slurred. Otherwise, cranial nerves were unremarkable. Motor wise, he showed marked truncal and gait ataxia; he was unable to walk because of ataxia. Muscle atrophy and marked weakness was noted in both upper extremities more on the left side. Deep tendon reflexes were diminished in the upper extremities but active in the lower extremities. He was polyuric; urinary specific gravity was low. Spinal fluid contained 6 cells/cmm and 113 mg/ dl of protein; Queckenstedt was positive. MRI revealed swelling of the cervical cord; in addition, the entire cervical region and the medullar oblongata appeared as high signal intensity areas. No mass lesion was noted in the supratentorial structures but the third ventricle was markedly enlarged. Surgical biopsy was performed on the cervical lesion. The patient was discussed in neurologic CPC, and the chief discussant arrived at the conclusion that the patient had germinoma with syncytiotrophoblastic giant cells in the diencephalic region which appeared to have been cured by radiation therapy; he thought that the cervical lesion was the seeding of germinoma. Cerebellar ataxia was ascribed to the remote effect of germinoma. Most of the participants thought that the original tumor was germinoma and the cervical lesion was its spread. Some participants thought that his ataxia was caused by germinoma cells involving the medulla and the inferior cerebellar peduncles. Histologic observation of the biopsied tissue from the spinal cord revealed the typical two cell patterned germinoma. Most of the tumor cells were not stained for an antibody against HCG, but some tumor cells were positively stained. Germinoma is very radio-sensitive; this patient showed T2 high signal lesion involving the medulla oblongata and cervical cord continuously. Probably, tumor cells in the lower brain stem escaped radiation, and gradually spread to the spinal cord over many years. At the time of operation, the surface of the spinal cord was free from tumor cells. Therefore, tumor cells invaded the spinal cord continuously from the medulla oblongata. He was treated with cervical radiation, and his neurologic as well as radiologic findings showed marked improvement.

Adult↗

[Variations in mesenchymal cell activity between rheumatic and non-rheumatic valve disease].

Deoxyribonucleic acid (DNA) synthesis of mesenchymal cells in the diseased valve tissue of patients with rheumatic and non-rheumatic valve diseases were compared. Surgically resected mitral valves from eight rheumatic and eight non-rheumatic patients in their 40s were examined immunohistochemically to estimate the activity of the various mesenchymal cells by cell cycle analysis, using monoclonal antibodies to cyclin E, A, B1, p53, and b cl-2 after routine tissue fixation, paraffin embedding and sectioning. Cyclin B1-positive fibrocytes and fibroblasts of the spongiosa and fibrosa were observed in all non-rheumatic cases, whereas some lymphocytes in the perivascular area were cyclin B1-, p53- and b cl-2-positive in rheumatic cases. The distinct qualitative difference in the mesenchymal cells of valve tissue between rheumatic and non-rheumatic etiologies suggests a different mode of valve pathology.

Adult↗

[A prospective controlled study of sairei-to in childhood IgA nephropathy with focal/minimal mesangial proliferation. Japanese Pediatric IgA Nephropathy Treatment Study Group].

To determine the effect of the Chinese herbal medicine, Sairei-to (TJ-114) in children with newly diagnosed IgA nephropathy showing focal/minimal mesangial proliferation, we undertook a prospective controlled study. One hundred and one patients were randomly assigned to receive Sairei-to for 2 years (group 1) or no drug for 2 years (group 2). Forty-six of the 50 patients in group 1 and 48 of the 51 patients in group 2 completed their trial. At entry, the two groups of patients did not differ in the clinical, laboratory and pathologic findings. At the end of the trial, urinary protein excretion and hematuria were significantly reduced in group 1, but were unchanged in group 2. Twenty-one group 1 patients (46%) had normal urine, but only 5 group 2 patients (10%) had normal urine at the end of the trial (p < 0.001). Blood pressure and creatinine clearance were normal at the end of the trial in all but one group 2 patient, who developed chronic renal failure. The present study demonstrates that 2-year Sairei-to treatment early in the course of disease is effective in children with IgA nephropathy showing focal/minimal mesangial proliferation.

Adolescent↗

Cardiomyopathies and mitochondrial DNA mutations.

Our former studies concerning mitochondrial DNA mutations were reviewed in this article. A 7.4 kb deletion between the D-loop and ATPase 6 genes was detected in myocardial tissue obtained at autopsy from patients with myocardial infarction, diabetes mellitus and also patients treated with adriamycin. A case with diabetes mellitus and hypertrophic cardiomyopathy is demonstrated which revealed a point mutation from adenine to guanine at position 3243 within tRNA Leu(UUR).

Adenosine Triphosphatases↗