Search PubMed⌕ Search

Biomedical subjects

N Okada

Publications and source records attributed to N Okada.

At least 289 records · Page 16Linked to original sources
PubMed1994

Interleukin-8 in chronic renal failure and dialysis patients.

A total of 105 patients participated in this study, including 10 with chronic glomerulonephritis with normal renal function (CGN patients), 36 uraemic patients (CRF patients), 19 continuous ambulatory peritoneal dialysis patients (CAPD) without peritonitis, three CAPD patients with peritonitis, 37 patients undergoing chronic haemodialysis (HD) divided into short-term HD, 15 patients; medium-term HD, 12 patients; and long-term HD, 10 patients. IL-8 and two other proinflammatory cytokines, IL-6 and TNF alpha were tested using a specific immunoassay. IL-8, IL-6, and TNF alpha serum levels were significantly increased in patients with chronic renal failure compared to their levels in normal individuals (P < 0.0001, P < 0.05 and P < 0.0001 respectively). The most pronounced increment in IL-8, IL-6 and TNF alpha serum levels was observed in CAPD patients (P < 0.0001). CAPD patients without peritonitis showed relatively low levels of IL-8 or IL-6 in peritoneal dialysate effluents (PDE), whereas PDE-TNF alpha were not detectable in almost all patients tested. Patients with peritonitis showed very high serum and PDE levels of IL-8, IL-6 and TNF alpha. The clinical recovery from peritonitis was characterized by a rapid fall in IL-8, IL-6 and TNF alpha in serum and dialysate. HD patients showed a significant increase in serum levels of IL-8 and also IL-6 and TNF alpha compared to normal individuals (P < 0.05, P < 0.05 and P < 0.01 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Cell-surface bound complement regulatory activity is necessary for the in vivo survival of KDH-8 rat hepatoma.

The monoclonal antibody 5I2 recognizes and functionally inhibits a Crry-like complement regulator molecule on rat cells (corresponding to human decay accelerating factor and membrane cofactor protein activity). The inhibition of complement regulatory activity by 5I2 antibody results in complement deposition on rat cell membranes exposed to homologous complement. Two subclones of KDH-8 rat hepatoma were selected for the experiments; one expressing high (CrryH) and the second low (CrryL) amounts of Crry-like antigen. Both sublines grow in vivo in syngeneic rats, but at lower cell doses (< 10(5) cells/rat) the survival time of rats injected with CrryL cells is prolonged. Injection of tumour-bearing rats with 5I2 monoclonal antibody intraperitoneally did not influence the tumour growth. However, it resulted in 50% mortality within a few hours, accompanied by severe haemorrhage in the peritoneal cavity. Pretreatment of the tumour cells with 5I2 monoclonal antibody or its F(ab')2 fragment substantially increased the survival time of recipient rats. Even permanent survivors were found, indicating that cell membrane-associated complement regulatory activity, which provides protection against attack of homologous complement, is necessary for in vivo tumour growth.

Animals↗
PubMed1994

Occipital roof development in the Japanese musk shrew, Suncus murinus.

The occipital squama of the Japanese musk shrew, Suncus murinus, consists only of membrane bone which arises from the periosteal bony band of the supraoccipital cartilage. No cartilaginous tectum posterius, generally forming the dorsal border to the foramen magnum, was found in the developing chondrocranium. Also additional intramembranous ossification centres were occasionally observed, and could be interpreted as being the primordium of the interparietal bone. These observations indicate that the membrane bone is homologous not with the interparietal bone but with the tectum posterius, i.e. the membranous supraoccipital bone. This is an instance of interchangeability between cartilage and membrane bone in a mammal.

Animals↗
PubMed1994

Establishment and characterization of the T-cell line, EBT-8 latently infected with Epstein-Barr virus from large granular lymphocyte leukemia.

An Epstein-Barr virus (EBV) genome-positive T-cell line, designated EBT-8, was established from peripheral blood of a patient with EBV genome-positive large granular lymphocyte leukemia of T-cell origin. The cells have been cultured continuously in RPMI-1640 medium supplemented with 10% fetal calf serum and 40 U/ml interleukin-2 for more than 18 months. Analysis of T-cell receptor gene rearrangement demonstrated similar rearrangement between the fresh leukemic cells and EBT-8 cell line. The cell line has several azurophilic granules in its cytoplasm and activated cytotoxic/suppressor T-cell surface antigens (CD2, CD3, CD8, HLA-DR and T-cell receptor alpha/beta). Karyotypic analysis of the cell line showed several chromosomal abnormalities. EBV DNA was demonstrated in the cells by Southern blot hybridization and about five copies of covalently closed circular DNA per cell were detected by Gardella gel analysis. Clonotypic episomal EBV DNA was observed in the cells by Southern blot hybridization with EBV-terminal fragment probe. EBV-encoded small RNA, EBER1 were demonstrated in all cells by in situ hybridization. EBV-encoded proteins, EBNA and LMP1 were demonstrated by immunofluorescence technique. EBV activation was observed after 12-O-tetradecanoylphorbol-13- acetate treatment of the cells. These results demonstrated the establishment of a T-cell line with latent EBV genomes and suggested the involvement of EBV to the large granular lymphocyte leukemia of T cells.

Adult↗
PubMed1994

[Pharmacokinetic study of ofloxacin using saliva concentration in chronic renal failure].

We evaluated saliva concentration as a parameter of therapeutic drug monitoring (TDM) of Ofloxacin (OFLX) in patients with severe renal failure (CRF). Saliva OFLX concentration correlated closely with serum OFLX concentration as shown in healthy subjects, although it was significantly lower (about three-quarters), indicating that OFLX had less penetration into saliva in patients with renal failure. Saliva concentration was almost equal to serum concentration during hemodialysis, which might have been due to the constant dialysis of OFLX. In conclusion, saliva concentration was useful for TDM of OFLX in patients with CRF, as it is in healthy subjects.

Adolescent↗
PubMed1993

Determination of the phylogenetic relationships among Pacific salmonids by using short interspersed elements (SINEs) as temporal landmarks of evolution.

Several subfamilies of the salmonid Hpa I short interspersed element (SINE) family were isolated from salmonid genomes and were sequenced. For each genomic locus that represented the subfamily, amplification by PCR of the orthologous loci in the 12 fish allowed us to determine the order of branching of the Pacific salmonid species. The deduced phylogeny suggests three evolutionary lines, namely, a line of chum salmon, pink salmon, and kokanee; a line of coho salmon and chinook salmon; and a line of steelhead trout. Our data also support a change in the phylogenetic assignment of steelhead trout from Salmo to Oncorhynchus. We present here an extensive phylogenetic tree constructed from an analysis of differential insertion of SINEs, and we propose that SINE insertion analysis is one of the best available methods for clarifying the order of divergence of closely related species.

Animals↗
PubMed1993

Molecular characterization of a short interspersed repetitive element from tobacco that exhibits sequence homology to specific tRNAs.

We have characterized a family of tRNA-derived short interspersed repetitive elements (SINEs) in the tobacco genome. Members of this family of SINEs, designated TS, have a composite structure and include a region structurally similar to a rabbit tRNA(Lys), a tRNA-unrelated region, and a TTG repeat of variable length at the 3' end. Southern blot hybridization, together with a search of the GenBank data base, showed that various plants belonging to the families Solanaceae and Convolvulaceae contain sequences homologous to the TS family in the introns and flanking regions of many genes, whereas Arabidopsis in the family Cruciferae and several species of monocoytledonous plants do not. The TS family is widely involved in structural and genetic variations in the genomes of many plants that belong to the order Tubiflorae. All of nine sequences identified in a data base search are truncated at their 5' regions and lack the tRNA-related region of the TS family. We characterized the entire sequence of the members of the TS family and found that this family can be categorized as a member of a group of SINEs with a tRNA(Lys)-like structure, as can several animal SINEs. The TS family can be divided into two major subfamilies by analysis of diagnostic positions, and one of the subfamilies is clearly younger than the other. Amplification of many copies of the full sequence of the younger subfamily occurred during the recent evolution of the tobacco lineage. We also discuss mechanisms that could be involved in the generation of SINEs in animals and also in plants.

Base Sequence↗
PubMed1993

Several short interspersed repetitive elements (SINEs) in distant species may have originated from a common ancestral retrovirus: characterization of a squid SINE and a possible mechanism for generation of tRNA-derived retroposons.

Using labeled transcripts generated in vitro from squid total genomic DNA as a probe, we isolated and characterized a SINE that is present in the squid genome. The squid SINE appears to be derived from a tRNA(Lys). When the consensus sequences of five different SINEs with a tRNA(Lys)-like structure from distantly related species, including squid, were aligned, we found in the tRNA-unrelated region two sequence motifs that were almost identical among these five SINEs. This observation suggests a common evolutionary origin for these SINEs and/or some function(s) for these motifs. Similar sequences were unexpectedly found to be present in sequences complementary to the U5 regions of several mammalian retroviruses whose primer is a tRNA(Lys). On the basis of these findings, we present a model for the generation of SINEs. We propose that they are derived from a "strong-stop DNA" with a primer tRNA(Lys) that is an intermediate in the reverse transcription of certain retroviruses. Our model suggests that a certain group of SINEs may have been generated by horizontal transmission, although it is not clear whether information was transmitted via a similar retrovirus or via an RNA or DNA of a SINE.

Animals↗
PubMed1993

Isolation of cDNAs encoding the catalytic domain of poly(ADP-ribose) polymerase from Xenopus laevis and cherry salmon using heterologous oligonucleotide consensus sequences.

We have isolated and sequenced cDNAs encoding the catalytic domain of poly(ADP-ribose) polymerase (PARP) from Xenopus laevis and Oncorhyncus masou (cherry salmon). The cDNAs were amplified by polymerase chain reaction using heterologous oligonucleotides corresponding to the conserved sequences of mammalian cDNAs as primers. The deduced amino acid sequences of Xenopus laevis and cherry salmon cDNA showed 84.4% and 75.6% similarities to that of human PARP, respectively. In both species, mRNA for PARP was identified as a single band of 4 kb, and PARP mRNA was abundant in ovary and brain. Thus, mixed oligonucleotide-primed amplification is a useful method in the cloning of cDNAs from different species, and the catalytic domain of PARP is conserved structurally among phylogenetically different species, suggesting an importance of poly(ADP-ribosyl)ation.

Amino Acid Sequence↗
PubMed1993

Brachytherapy for stage I & II oral tongue cancer: an analysis of past cases focusing on control and complications.

An analysis of the therapy used for 370 tongue cancer patients has been made, said patients having been treated by interstitial irradiation alone or by combined external irradiation and brachytherapy (Stage I:90 cases, IIa: 196 cases; and IIb: 84 cases). The neck was followed by close follow-up (304 cases), treated by elective neck irradiation (56 cases), or underwent operation at the time of local recurrence (10 cases). The results have shown that the 5-year survivals for Stages I, IIa, and IIb were 84%, 78%, and 72%, respectively. further, the 5-year primary control was 85% for tumors of the superficial type, 79% for tumors of the exophytic type, and 45% for tumors of the infiltrative type (p < 0.004). In non-electively irradiated patients, a neck metastasis occurred in 31% in Stage I, 41% in Stage IIa, and 51% in Stage IIb. Finally, 110 patients incurred radiation-induced complications (110/291 = 38%) and 11 patients (11/291 = 4%) required a surgical procedure. Brachytherapy for tongue cancer achieved results that are comparable with surgery. The analysis also revealed that the introduction of computer dosimetry and the use of a spacer (a dental guard) in brachytherapy have achieved superior results in the management of a tongue cancer.

Adult↗
PubMed1993

Rapid transformant selection by human complement using HRF20 (CD59) cDNA as a selection marker.

The 20 kDa homologous restriction factor (HRF20, CD59) prevents formation of membrane attack complexes of human complement. Transfection of the cDNA of HRF20 to heterologous cells, which are sensitive to human complement, thereby renders these cells resistant to human complement attack. This property can then be used as a selection marker of transfection. In addition, the procedure is short and can be performed within 8 h. Since only 1 h is required for incubation with complement, the damage to the transfected cells is limited compared with damage resulting from selection for drug resistance which requires 10 days or more of incubation in the presence of harmful agents.

Animals↗
PubMed1993

Close phylogenetic relationship between Vestimentifera (tube worms) and Annelida revealed by the amino acid sequence of elongation factor-1 alpha.

To clarify the phylogenetic position of Vestimentifera (tube worms), 346-bp fragments of the elongation factor-1 alpha (EF-1 alpha) gene (939-1286 according to the numbering of the human gene) of a vestimentiferan, Lamellibrachia sp., a sternaspid polychaete, Sternaspis scutata, an earthworm, Pheretima sp., and a gastropod, Alviniconcha hessleri, were sequenced. From the amino acid sequences of these EF-1 alpha, and those of two other vertebrates and two arthropods, phylogenetic relationships were deduced by the maximum likelihood (ML) method, by which the phylogenetic tree can be inferred without assuming constancy of the molecular evolutionary rate. For the ML tree and all of seven alternative trees, whose log-likelihoods could not be discriminated from that of the ML tree by the criterion of the standard error, the vestimentiferan, the polychaete, and the oligochaete formed a clade, excluding the arthropods and the gastropod as outgroups. This result is convincing evidence that Vestimentifera are protostomes that are closely related to Annelida. The ML tree suggests that Vestimentifera are more closely related to Polychaeta than to Oligochaeta, though the data were not sufficient to discriminate these three groups at a significant level. From recent evidence such as morphological characteristics and molecular information, it may safely be said that vestimentiferans should be included in the Annelida provided this phylum contains polychaetes and oligochaetes.

Amino Acid Sequence↗
PubMed1993

A model for the mechanism of initial generation of short interspersed elements (SINEs).

Most animal genomes contain a large number of short interspersed elements (SINEs) that have a composite structure and contain a region that is homologous to a tRNA. The majority of SINEs have been found to be derived from a tRNA(Lys), being categorized as members of a superfamily of tRNA(Lys)-related SINEs. The consensus sequences of five SINEs that belong to this superfamily were aligned. It was found that, in the tRNA-unrelated region, there are two sequence motifs that are almost identical among these five SINEs and are at a distance of 10-11 nucleotides from each other. This observation suggests a common evolutionary origin of these SINEs and/or some function(s) for these motifs. Similar sequences were unexpectedly found to be present in the sequences complementary to the U5 regions of several mammalian retroviruses whose primer is a tRNA(Lys). On the basis of these findings, we propose a possible model for the generation of SINEs whereby they are derived from a "strong stop DNA" with a primer tRNA that is an intermediate in the process of reverse transcription of certain retroviruses.

Animals↗
PubMed1993

Elimination of HIV-infected cells by lymphocytes armed with a bifunctional antibody to gp120 of HIV and CD3.

The T-cell receptor (TCR) can acquire a new antigen binding site by treatment with a bifunctional antibody (BFA) prepared with mAb against a specified antigen and an epitope of the TCR. Lymphocytes armed with BFA directed to CD3 and an HIV antigen were able to eliminate all HIV antigen-positive cells during incubation with a mixture of HIV-infected and uninfected cells. HIV antigen-positive cells even from persistently infected cells were undetectable with immunofluorescence staining although HIV genes were detectable by polymerase chain reaction (PCR) amplification indicating that only dormantly infected or low producer cells, if any, survived. This suggests that HIV antigen-positive cells could be eliminated by administration of BFA-armed lymphocytes leaving HIV patients with only dormantly infected or low producer cells.

Antibodies, Bispecific↗
PubMed1993

Growth inhibitory effect of eicosapentaenoic acid on cultured human epidermal keratinocytes.

The effect of eicosapentaenoic acid (EPA, 20:5n-3) on the proliferation of cultured human epidermal keratinocytes was investigated. The keratinocytes were treated with 3 micrograms/ml of EPA for 48 h and then their fatty acid composition was analyzed by gas liquid chromatography. A significant amount of EPA was incorporated by the cells. The treatment with EPA at concentrations of 0.3-6.0 micrograms/ml resulted in a dose-dependent inhibition of the growth of the cells. These results indicate that EPA can be incorporated by cultured keratinocytes and change their fatty acid composition, which might endogenously affect their growth.

Adolescent↗
PubMed1993

Antisense sequences of 20-kDa homologous restriction factor (HRF20) are found in C9 and the C8 beta chain of homologous complement.

We examined, on the basis of the fact that sense and antisense peptides have affinity for each other, whether any relationship exists between homologous restriction factor (HRF20), a membrane inhibitor of the terminal stage of homologous complement attack, and the antisense sequence of the terminal complement components C8 and C9. In this article, we demonstrate that there are two regions of C9 that contain antisense sequences to one continuous region of HRF20 and that this relationship exists between human HRF20 and human C9, but not mouse C9. We also found one region of the C8 beta chain that contains an antisense sequence to HRF20.

Amino Acid Sequence↗