Biomedical subjects

E Kudo

Publications and source records attributed to E Kudo.

At least 19 recordsLinked to original sources

PubMed1998

Polymorphisms of thymidine kinase gene in herpes simplex virus type 1: analysis of clinical isolates from herpetic keratitis patients and laboratory strains.

Drug-resistance of herpes simplex virus (HSV) is caused most frequently by mutation of the viral thymidine kinase (TK) gene. To elucidate the significance of detecting nucleotide changes of the TK gene for screening drug-resistant viruses, the frequency and variation of the genetic polymorphisms in the whole coding region of the TK gene were studied in 14 acyclovir-susceptible HSV type 1 (HSV-1) clinical isolates from 14 patients with epithelial herpetic keratitis. Two reference HSV-1 laboratory strains, McKrae and PH, and two acyclovir-resistant variants of the PH strain were also studied as controls. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing detected nucleotide differences at 24 positions, and amino acid substitutions at 12 codons in the TK gene of the examined viruses. Nucleotide diversity of 0.0029 per base (the average number of nucleotide substitutions of 3.3 per 1,131 base pairs) in the TK gene in the clinical isolates was comparable to 0.0037 per base of the whole HSV-1 genome in Japanese isolates reported previously. PCR-SSCP analysis of the acyclovir-resistant strains easily detected aberrantly shifted bands by comparing them with those of the parental strain, followed by the quick determination of mutated sequences. These results suggest that detection of nucleotide changes of the TK gene is useful for serial observation of persistent or recurrent HSV infection as observed in immunocompromised hosts, but that it is not useful for screening drug-resistant viruses from nonepidemic clinical isolates because of the comparable genetic polymorphisms in the TK gene as in the whole HSV-1 genome.

Acyclovir↗

PubMed1998

[In vitro antibacterial activity of vancomycin in combination with panipenem against carbapenem-resistant MRSA].

The synergistic relationship between vancomycin (VCM) and carbapenem (CRB) has been reported in antibacterial activity against CRB-resistant strains of MRSA. The purpose of this study is to investigate the antibacterial activity against CRB-resistant MRSA using VCM, panipenem (PAPM), and a combination of both. 8 strains of CRB-resistant MRSA were used to examine the effects of these antibiotics by the broth microdiluton technique. The effect of pH (pH 6, 7, 8) on MIC of VCM alone was not observed in 7 out of 8 strains; MICs were between 1.0-2.0 micrograms/ml. PAPM alone, however, showed an enhancing tendency in alkaline condition in 6 out of 8 strains. There was no influence of pH on MICs in the combination use of VCM and PAPM, showing additive effect in 1 strain and synergistic in 6 strains. Killing-curves against PAPM-resistant MRSA were examined under the following drug combinations; 1/4 MIC of VCM (0.5 micrograms/ml) plus 1/4 MIC of PAPM (16 micrograms/ml), and 1/4 MIC of VCM plus 1/8 MIC of PAPM (8 micrograms/ml). The former drug combination showed synersistic effect; decrease from 1.05 x 10(5) to 6.45 x 10(4) CFU/ml after 6 hours' incubation and to less than 10 CFU/ml after 24 hours. The latter drug combination showed synergistic activity (2.68 x 10(2) CFU/ml) after 24 hours' incubation, but lost antibacterial activity after 48 hours. In conclusion, PAPM in combination with VCM showed synergistic effects on CRB-resistant MRSA. This combination therapy should be evaluated for the treatment of MRSA infection in patients with renal dysfunction.

Carbapenems↗

PubMed1997

p53 gene mutation in N-butyl-N-(4-hydroxybutyl)nitrosamine-induced urinary bladder tumors and N-methyl-N-nitrosourea-induced colon tumors of rats.

We analyzed p53 mutations in 17 N-butyl-N-(4-hydroxybutyl) nitrosamine-induced bladder transitional cell carcinomas (TCCs) with or without areas of squamous cell carcinoma (SCC) of Long-Evans Cinnamon (LEC) and F344 rats, and in 7 N-methyl-N-nitrosourea-induced colon adenocarcinomas of LEC rats by polymerase chain reaction-single strand conformation polymorphism analysis and DNA sequencing. Of these bladder tumors, one TCC with moderately differentiated SCC had a T to G transversion mutation at codon 141, leading to a Val to Gly amino acid change. No p53 mutation was found in colon adenocarcinomas. Thus a p53 gene mutation seems infrequent in these rat bladder and colon carcinogenesis models even in the late stage.

Animals↗

PubMed1997

Robertsonian translocations in Paget's disease of bone.

The karyotypes of 14 patients with Paget's disease of bone were studied. The patients were recruited from our bone metabolism clinic where they received specific therapy for their skeletal disease. Eight of the 14 patients had chromosomal translocations localized to the D and G groups. None of the patients were related to one another, nor had any had the same lifelong environment. Thus, 57% of a sample of active patients with Paget's disease had Robertsonian translocations. By comparison, an age and sex-matched group of eight controls and 13 patients with osteoporosis who had been treated with bisphosphonates demonstrated no Robertsonian translocations. The prevalence of Robertsonian translocations in 14,000 newborns was reported to be 0.1%. These data suggest that a factor from the environment introduced during the lifetime of the patient could be present and could, in addition to genetic factors, affect gene replication during the development of Paget's disease.

Aged↗

PubMed1997

[In vitro combination effect of vancomycin and carbapenems against carbapenem-resistant MRSA].

We determined in vitro combined effects of vancomycin (VCM) plus carbapenems (CRBs) on 12 methicillin-resistant Staphylococcus aureus (MRSA) which are resistant to CRBs. Combinations of VCM plus imipenem (IPM) and VCM plus panipenem (PAPM) and VCM plus meropenem (MEPM) indicated synergistic effects, fractional inhibitory concentration (FIC) indices of < or = 0.05, against 67%, 75%, 67% of the strains, respectively. Against forty two percent of strains tested, 1 MIC of VCM was equal to 1 MBC, and similarly, IPM, PAPM and MEPM had 1 MIC = 1 MBC against 42%, 67% and 75% of the strains tested, respectively. Combinations of VCM plus IPM and VCM plus PAPM and VCM plus MEPM showed synergistic effects, hence a fractional bactericidal concentration (FBC) index of < or = 0.50, against 42%, 50%, 75% of the strains, respectively, and the combination of VCM plus MEPM was most synergistic. These results suggest that combination therapy of VCM with CRB is useful for the treatment of MRSA infection in patients with renal dysfunction.

Anti-Bacterial Agents↗

PubMed1996

Detection of herpes simplex virus DNA in tear fluid of stromal herpetic keratitis patients by nested polymerase chain reaction.

The value of the polymerase chain reaction (PCR) in the diagnosis of stromal herpetic keratitis was examined using tear fluid specimens; the sensitivity of the nested PCR method in detecting the herpes simplex virus (HSV) genome was 1 plaque-forming unit/mL. PCR assay of 72 tear samples from the eyes of 15 patients with stromal herpetic keratitis detected the HSV genome in 5 (33.3%). No positive band was detected in 20 tear samples from both eyes of 10 healthy volunteers. Seven of 38 tear samples (18.4%) and 1 of 34 samples (2.9%) collected from the diseased eye and the contralateral normal eye, respectively, produced positive results; the difference in rates was statistically significant (P < 0.05). The positive rate of samples collected from the diseased eye during an active phase was 16.0% (4 of 25 samples); in the quiescent phase, 23.1% (3 of 13 samples); the difference was not significant (P = 0.45). In HSV genome-positive cases, the average number of tear collections needed to detect the HSV genome was 3.3. Results indicate that PCR assay of tear fluid provides valuable information for the diagnosis of stromal herpetic keratitis, and that repeated tear samples should be collected regardless of the phase of the phase of disease activity.

Administration, Topical↗

PubMed1995

[Determinants of task preferences when performance is indicative of individual characteristics: self-assessment motivation and self-verification motivation].

The present study was conducted to examine determinants of information-gathering behavior with regard to one's own characteristics. Four tasks with different self-congruent and incongruent diagnosticity were presented to subjects. As self-assessment theory predicted, high diagnostic tasks were preferred to low tasks. And as self-verification theory predicted, self-congruent diagnosticity had a stronger effect on task preference than self-incongruent diagnosticity. In addition, subjects who perceived the relevant characteristics important inclined to choose self-assessment behavior more than who did not. Also, subjects who were certain of their self-concept inclined to choose self-verification behavior more than who were not. These results suggest that both self-assessment and self-verification motivations play important roles in information-gathering behavior regarding one's characteristics, and strength of the motivations is determined by the importance of relevant characteristics or the certainty of self-concept.

Adult↗

PubMed1994

Transgenic expression of IL-10 in pancreatic islet A cells accelerates autoimmune insulitis and diabetes in non-obese diabetic mice.

To study the paracrine effect of IL-10 on autoimmune insulitis and diabetes, we produced IL-10 transgenic non-obese diabetic (NOD) mice (NOD-IL-10) in which murine IL-10 was expressed in pancreatic islet A cells under the control of a rat glucagon promoter without directly manipulating pancreatic islet B cells. Among 11 founder mice, four of four males and three of seven females developed diabetes by 10 weeks of age. Histological analysis of six NOD-IL-10 revealed severe insulitis and prominent ductal proliferation. NOD-IL-10 also showed spotty lymphocytic infiltration in the lung and liver in four of six founder mice. The onset of diabetes in NOD-IL-10 was remarkably earlier than that of 14 weeks of age at the earliest in female non-transgenic NOD mice. When the NOD-IL-10 mouse was backcrossed to C57BL/6 mice, none of the resulting F1, B-N2 or B-N3 generation toward C57BL/6 mice showed diabetes even at 39 weeks of age, in spite of the presence of peri-insulitis and prominent ductal proliferation, while two of four mice of the N-N2 generation toward NOD mice showed early-onset diabetes. Thus, transgenic paracrine expression of IL-10 in situ in the NOD genetic background enhances autoimmune insulitis and diabetes in their onset and severity, ignoring gender difference. Because expression of IL-10 was detected by polymerase chain reaction in pancreatic islets of non-transgenic NOD mice after 5 weeks of age, IL-10 secreted in situ is regarded to enhance cell-mediated autoimmune diabetes, in spite of established in vitro anti-Th1 activity of IL-10.

Animals↗

PubMed1994

Multiple fluorescence-based PCR-SSCP analysis.

Multiple fluorescence-based polymerase chain reaction single-strand conformation polymorphism (MF-PCR-SSCP) was developed. The target sequence was amplified by PCR using forward and reverse primers labeled with two different fluorescent dyes at their 5' ends. The amplified products were then heat-denatured, mixed with internal standard DNA markers labeled with a third fluorescent dye and applied to a temperature-controlled gel in an automated DNA sequencer, with a gel-temperature-controlling system. Mutations were detected as positional shifts of two-colored peaks in the electrophoretogram. The image data were analyzed by the computer program GENESCAN 672. The peak positions were standardized to internal DNA size markers. MF-PCR-SSCP analysis of 7 human tumor cell lines with 7 different single base mutations of the human K-ras oncogene detected all mutations even under the same electrophoresis conditions. Complete loss of heterozygosity was detected in two cell lines simultaneously. A gel temperature at 20 degrees C and polyacrylamide concentration of 10% gave the best separation. MF-PCR-SSCP is superior to the current PCR-SSCP in several ways: it does not involve radioactivity, migration patterns are standardized to internal standard DNA markers, there is a strict temperature-controlling system and the higher percentage of the gel enables better separation with resultant 100% detection of mutations most likely under one set of electrophoresis conditions.

Base Sequence↗

PubMed1993

Molecular cloning of human amidophosphoribosyltransferase.

The cDNA of human amidophosphoribosyltransferase (EC 2.4.2.14, ATase), which is the supposed regulatory allosteric enzyme of de novo purine nucleotide biosynthesis, has been cloned from human hepatoma (HepG2) cDNA library. The predicted open reading frame encodes a protein of 517 amino acids with a deduced molecular weight (Mr) of 57,398, which is consistent with the molecular mass of 56 kDa on SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of the ATase subunit purified from human placenta. The derived amino acid sequence exhibits 93, 82, 41, 37, and 33% identity with the sequences of rat, chicken, Bacillus subtilis, Escherichia coli, and Saccharomyces cerevisiae ATases, respectively. Southern blot analysis suggested that the ATase gene exists as multiple copies. ATase mRNA (3.5 kb) is ubiquitously expressed in various human tissues. Comparison with rat and chicken ATases showed that two cysteine residues for an iron-sulfur cluster were conserved. Four consensus phosphorylation sites for cAMP-dependent protein kinase were found.

Amidophosphoribosyltransferase↗

PubMed1993

Development of T cells in SCID mice grafted with fetal thymus from AKR mice or F344 rats.

To examine the development of T cells within an allogeneic or xenogeneic environment, we engrafted the fetal thymus from AKR mice or F344 rats under the kidney capsule of SCID mice (mTG and rTG mice). T lymphopoiesis developed in SCID mice 2 months after transplantation, although the ratio of CD4/CD8 in both experimental groups was different from that of normal control. T cells in mTG mice did not show in vitro proliferation or cytotoxicity against either host-type C.B-17 (H-2d) or donor-type AKR (H-2k) cells, while they exerted potent activities against third-party B10 (H-2b) cells. In contrast, T cells in rTG mice exhibited proliferation against both host-type C.B-17 and donor-type F344 rat cells. Consistently, graft-vs.-host disease symptoms developed in these mice and histological examination showed impressive infiltration of lymphocytes into the skin or into the mucosal layers of the stomach. Activated state of T cells in rTG mice was also evidence by the positive expression of interleukin-2 receptor. Taken together, fetal thymus appears to contain progenitor cells which are sufficient for in vivo reconstitution of T lymphopoiesis, but species-specific environment is important for the induction of tolerance. In mTG mice, V beta 6+ T cells reactive to donor Mlsa determinants and V beta 3+ T cells reactive to host Mlsc determinants were deleted, suggesting that tolerance was regulated mainly by clonal deletion. By contrast, V beta 11+ T cells reactive to Mlsf determinants were not deleted possibly due to the lack of their ligands.

Animals↗

PubMed1992

Malignant peripheral nerve sheath tumors: an immunohistochemical study in relation to ultrastructural features.

The constituent cells in malignant peripheral nerve sheath tumors were examined by studying the expression of immunohistochemical markers for Schwann cells and perineurial cells in relation to ultrastructural features in 12 malignant peripheral nerve sheath tumors. Ultrastructural studies demonstrated mixed proliferation of Schwann cells, perineurial cells, fibroblastic cells, and primitive cells in many malignant peripheral nerve sheath tumors. Expression of S-100 protein was well correlated with Schwann cell-like differentiation of tumor cells. However, Leu-7 and epithelial membrane antigen, which have been considered to be specific to Schwann cells and perineurial cells, respectively, were common to Schwann cells, perineurial cells, and primitive cells. The common immunophenotypic expression suggests a close relationship among these cell types. The unusual expression of cytokeratin could be explained by the plasticity of intermediate filament expression.

Adult↗

PubMed1992

Epitopic heterogeneity of the CD36 antigen expressed by normal and neoplastic endothelial cells. An immunohistochemical study with a novel monoclonal antibody 8C9.

Phenotypic and functional heterogeneity of endothelial cells (ECs) is being recognized with increasing frequency. Here we report a novel murine monoclonal antibody (MoAb), named 8C9, that detects a unique epitope on the leukocyte differentiation antigen CD36 (platelet glycoprotein IV or IIIb) expressed by both normal and neoplastic ECs. In immunohistochemical and flow-cytometric studies, 8C9-immunoreactivity was detected on capillary ECs, adipocytes, monocytes, platelets and a human monocytoid cell line U-937, which are known to express the CD36 antigen. Blocking experiments using U-937 cells and studies on cryostat sections revealed that a murine MoAb OKM5, which detects the CD36 antigen, blocked the binding of 8C9 to its antigen. Immunoblot analysis showed that 8C9 bound to a 97-kDa membrane protein expressed by U-937 cells treated with phorbol ester. These results indicate that 8C9 detects the CD36 antigen. However, the findings that some OKM5-positive normal ECs in the liver, spleen and lymph nodes as well as neoplastic ECs in a cutaneous angiosarcoma did not react with 8C9, together with the fact that the CD36 antigen does not form a complex or associate with other proteins, suggest epitopic heterogeneity of the CD36 antigen expressed by these tissues.

Antibodies, Monoclonal↗

PubMed1991

Immunophenotypic heterogeneity in osteosarcomas.

Eighteen osteosarcomas were studied immunohistochemically. The tumors were classified into the following six histologic subtypes: five osteoblastic, four chondroblastic, four malignant fibrous histiocytoma-like, two telangiectatic, two low-grade central, and one giant cell-rich. Variable amounts of osteocalcin immunoreactivity were found in all tumors. Factor XIIIa-positive cells, which may be of fibrohistiocytic lineage, were present in three tumors of the malignant fibrous histiocytoma-like type, one of the telangiectatic type, one of the low-grade central type, and the tumor of the giant cell-rich type. One tumor of the osteoblastic type showed cytokeratin and epithelial membrane antigen immunoreactivities. The positive reactions for desmin in four tumors, for alpha-smooth muscle actin in 11 tumors, and for type IV collagen in one tumor seemed to indicate myofibroblastic differentiation of some tumor cells. S-100 protein-positive tumor cells were detected not only in all four tumors of the chondroblastic type, but also in three of the osteoblastic type, one of the low-grade central type, and in the tumor of the giant cell-rich type. These immunohistochemical results suggest that osteosarcomas are composed of heterogeneous cell populations, such as those of the osteoblastic, chondroblastic, myofibroblastic, and fibrohistiocytic types, and occasionally also of cells with epithelial features.

Adolescent↗

PubMed1991

Undifferentiated carcinoma of the vulva mimicking epithelioid sarcoma.

We report an undifferentiated sweat gland carcinoma of the vulva in an 80-year-old woman. The tumor, which was located in the right labium majus, resembled an epithelioid sarcoma histologically; it had a granulomatous appearance with multiple tumor nodules containing epithelioid tumor cells. The tumor also contained rhabdoid cells; a large cluster of them showed histological features indistinguishable from those of a malignant rhabdoid tumor. Immunohistochemically, the tumor cells reacted not only for epithelial markers such as cytokeratins, EMA, and CEA, which are known to be expressed by epithelioid sarcoma, but also for CA125 and with monoclonal antibodies recognizing sweat gland structures--namely, EKH5 and EKH6. For comparison, two epithelioid sarcomas and two extrarenal malignant rhabdoid tumors were also studied. Of these tumors, only one extrarenal rhabdoid tumor reacted with EKH5, and none reacted for CA125. Electron-microscopic examination of the present tumor showed the presence of discontinuous basal laminae and tonofibril-like structures as well as primitive cell junctions and interdigitating filopodia. From these findings, we conclude that the tumor was an undifferentiated sweat gland carcinoma mimicking an epithelioid sarcoma. Findings in this case support the idea of the diverse histogenesis of extrarenal malignant rhabdoid tumors and indicate that electron microscopy is important for differentiating epithelioid sarcoma from skin adnexal carcinoma.

Aged↗

PubMed1991

Atypical primitive neuroectodermal tumors. Comparative light and electron microscopic and immunohistochemical studies on peripheral neuroepitheliomas and Ewing's sarcomas.

Recently, primitive neuroectodermal tumors (PNETs) have been shown to cover a wide spectrum of small round cell sarcomas, probably including some Ewing's sarcomas (ESs) and extraskeletal Ewing's sarcomas (EESs), in addition to classical peripheral neuroepitheliomas (PNs). In studies of small cell sarcomas, we found a group of undifferentiated tumors resembling PNETs with some features of neuroectodermal differentiation, but possessing areas of relatively large, pleomorphic cells. To clarify the nature of these tumors and their relationship to PNETs, we examined the variety of histological, immunohistochemical and ultrastructural features of 11 small cell sarcomas. Five of these tumors were composed of uniform, small round cells and were classified as PNs because of the presence of definite Homer-Wright rosettes and fibrillary processes. The presence of well developed neurite-like processes containing neurosecretory granules and immunoreactivities for various neural markers suggested that these PNs showed more advanced neuronal differentiation. Two tumors, with the classical features of ES, showed no ultrastructural evidence of neuronal differentiation, although only gamma-gamma neuron-specific enolase (NSE) positivity was detected. Four undifferentiated tumors with atypical features, included in this study as an atypical PNET group, showed certain neuroectodermal characteristics, such as ganglion cell differentiation, perivascular pseudorosettes, and gamma-gamma NSE reactivity. It is concluded from this study that PNETs may include small round cell tumors showing different degrees of neuro-ectodermal differentiation and some histological variations.

Adolescent↗

PubMed1990

Cytoskeletal characteristics of myofibroblasts in benign neoplastic and reactive fibroblastic lesions.

The characteristics of the cytoskeleton of myofibroblasts were examined immunohistochemically in 10 extra-abdominal desmoid tumours, 3 palmar and 2 plantar fibromatoses and 5 nodular fasciitis; in the cultured cells of one desmoid tumour, and also ultrastructurally in 3 desmoid tumours. Polyclonal anti-desmin antibody reacted with the cells in 7 extra-abdominal desmoid tumours, 1 palmar fibromatosis, 1 plantar fibromatosis and 3 nodular fasciitis. Monoclonal antidesmin antibody reacted with cells in only 2 desmoid tumours. Desmin-positive spindle cells were scattered throughout these lesions. There were no marked ultrastructural differences between desmin-positive and desmin-negative desmoids. All specimens except one specimen of nodular fasciitis showed immunoreactivity for alpha-smooth muscle actin and vimentin. Muscle actin-positive cells were observed in all specimens. Cultured cells gave positive reactions with polyclonal desmin antibody as well as to vimentin antibodies and two preparations of actin antibodies, whereas the original tumour did not react with desmin antibody. The present studies suggested that the cytoskeleton of some myofibroblasts in both neoplastic and reactive lesions resembles that of smooth muscle cells.

Actins↗

PubMed1990

Cytoskeletal properties of alveolar soft part sarcoma.

The immunohistochemical expression of cytoskeletal proteins in alveolar soft part sarcoma (ASPS) was studied by light and electron microscopy. Of the five cases examined by the avidinbiotin-peroxidase complex method, variable numbers of immunoreactive cells for desmin were found in three, for vimentin in two, for muscle-specific actins in three, and for alpha-smooth muscle actin in four. Immunoelectron microscopic study demonstrated that desmin and vimentin were localized on whorled bundles of intermediate filaments in the perinuclear cytoplasm. In addition, a few dispersed intermediate filaments became evident in specimens treated with saponin and fixed with tannic acid. These immunohistochemical results indicate that a few tumor cells of ASPS may express some properties of the cytoskeleton of smooth muscle cells in addition to those of skeletal muscle cells. Considering the discrepancies reported in the actin isoforms demonstrated in myogenic tumors, we conclude that ASPS is probably a peculiar, primitive myogenic tumor that does not show any distinctive features of rhabdomyogenic or leiomyogenic differentiation.

Actins↗