Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

At least 505 records · Page 28Linked to original sources

PubMed1995

Intraspecific variation of Taenia taeniaeformis as determined by various criteria.

The intraspecific variation of four laboratory-reared isolates of Taenia taeniaformis the SRN and KRN isolates from Norway rats, Rattus norvegicus, captured in Japan and Malaysia, respectively; the BMM isolated from a house mouse, Mus musculus, captured in Belgium; and the ACR isolate from a gray red-backed vole, Clethrionomys rufocanus bedfordiae, captured in Japan was examined by various criteria. Eggs of each of the four isolates were orally inoculated into several species of intermediate host. They were most infective to the rodent species from which the original metacestode of each isolate had been isolated in the field, and only the ACR isolate was infective to the gray red-backed vole. Although little difference was found between the SRN, KRN, and BMM isolates by the other criteria, including the morphology of rostellar hooks, the protein composition of the metacestode, and restriction endonuclease analysis of DNA, the ACR isolate was clearly different from the others. It was considered that the ACR isolate was independent as a strain distinct from the other three isolates.

Animals↗

PubMed1995

Phylogenetic relationships within Taenia taeniaeformis variants and other taeniid cestodes inferred from the nucleotide sequence of the cytochrome c oxidase subunit I gene.

Nucleotide sequence variations in a region of the mitochondrial cytochrome c oxidase subunit I (COI) gene (391 bp) were examined within seven species of the genus Taenia and two species of the genus Echinococcus, including ten isolates of T. taeniaeformis and six isolates of E. multilocularis. More than a 12% rate of nucleotide differences between taeniid species was found, allowing the species to be distinguished. In E. multilocularis, no sequence variation was observed among isolates, regardless of the host (gray red-backed vole, tundra vole, pig, Norway rat) or area (Japan, Alaska) from which each metacestode had been isolated. In contrast, six distinct sequences were detected among the ten T. taeniaeformis isolates examined. The level of nucleotide variation in the COI gene within T. taeniaeformis isolates except for one isolate from the gray red-backed vole (TtACR), which has been proposed as a distinct strain or a different species, was about 0.3%-4.1%, whereas the COI gene sequence for TtACR differed from those of the other isolates, with levels being 9.0%-9.5%. Phylogenetic trees were then inferred from these sequence data using two different algorithms.

Amino Acid Sequence↗

PubMed1995

Relation between collateral flow assessed by Doppler guide wire and angiographic collateral grades.

We investigated the relation between the angiographic collateral grade (Rentrop's classification) and the collateral flow velocity pattern in 43 patients with angina pectoris. Collateral flow velocity was measured with a Doppler guide wire during balloon occlusion in coronary angioplasty. Collateral flow was detected in 21 of the 43 patients. In 6 of the 21 patients, collateral vessels were not seen angiographically before angioplasty. The direction of collateral flow was classified as forward, backward, or bidirectional. Forward and backward collateral flows were seen in all angiographic grades. Bidirectional collateral flows were observed only in grades 0 to 2. The peak collateral flow velocity was not correlated with the angiographic grades, but the ratio of the collateral flow duration to a cardiac cycle length was correlated with them (grade 0, 44% +/- 15%; grade 1, 70% +/- 16%; grade 2, 84% +/- 11%; and grade 3, 93% +/- 3%; p < 0.0005, analysis of variance). The peak velocity integral was also correlated with the angiographic collateral grades (p < 0.05; analysis of variance). The peak velocity integral was also correlated with the angiographic collateral grades (p < 0.05; analysis of variance). Electrocardiographic signs of ischemia were less observed in patients with unidirection and longer duration of collateral flow pattern (p < 0.05, respectively). A Doppler guide wire may be useful in assessing collateral flow grade.

Aged↗

PubMed1995

Intraspecific variation of isoenzymes in Taenia taeniaeformis.

The technique of isoenzyme electrophoresis was applied to Japanese wild populations of Taenia taeniaeformis (isolated from Norway rats) and three laboratory reared isolates (KRN isolated from a Malaysian Norway rat, BMM from a Belgian house mouse and ACR from a Japanese gray red-backed vole). The average heterozygosities of Japanese wild populations were fairly small and total genetic variability was 0.0499. The genetic make-up of T. taeniaeformis in Norway rats was rather uniform in the whole of Japan. In KRN isolate, each of all 10 loci examined possessed the allele which was predominant in Japanese wild populations. Similarly, each of 9 loci in BMM isolate possessed the same alleles, but one of 2 alleles at HK locus was different from that in the others. T. taeniaeformis parasitizing house mice and rats were considered to be genetically closely related to each other. In ACR isolate, 7 out of 10 loci possessed different alleles from those in the other populations. It was considered that ACR isolate was genetically distant and its phylogenetic origin in Japan should be different from worms parasitizing Norway rats.

Animals↗

PubMed1995

Cryopreservation of wild mouse spermatozoa.

Spermatozoa of wild mice from China, Czechoslovakia, Denmark, India, Japan and Switzerland were frozen and stored at -196 degrees C. After thawing, intact oocytes were inseminated in vitro with relatively high motility frozen-thawed mouse spermatozoa from Czechoslovakia, Denmark and India, while oocytes with a partially dissected zona were inseminated with low motility frozen-thawed spermatozoa from China, Japan and Switzerland. Embryos developing to the 2-cell stage from oocytes fertilized with frozen-thawed spermatozoa were transferred to the oviducts of female recipients on the first day of pseudopregnancy (day when a vaginal plug was confirmed). Successful embryo development to the 2-cell stage was 46 to 67%. Offspring resulted from 17 to 51% of these transferred 2-cell embryos.

Journal Article↗

PubMed1995

Interleukin-1 beta (IL-1 beta) and acute leukemia: in vitro proliferative response to IL-1 beta, IL-1 beta content of leukemic cells and treatment outcome.

We evaluated the in vitro proliferative response to exogenous IL-1 beta in terms of tritiated thymidine (3H-TdR) incorporation in leukemic cells obtained from 119 patients with various types of acute leukemia. The content of IL-1 beta in leukemic cells was measured by enzyme-amplified sensitivity immunoassay. We observed a significant proliferative response to exogenous IL-1 beta in leukemic cells from 27/66 patients with de novo AML, 1/29 patients with ALL, 2/3 patients with AUL, 8/12 patients with AML arising from MDS, 4/7 patients with myeloid crisis of CML, and 0/4 patients with lymphoid crisis of CML. Proliferation was marked in myeloid leukemic cells of a more premature stem cell origin. There were no significant differences in proliferative responses among the different FAB classes of de novo AML. The IL-1 beta content of leukemic cells was low in patients with lymphoid leukemia, but there was no significant difference among the various types of myeloid leukemia. There was no correlation between the proliferative response to exogenous IL-1 beta and the IL-1 beta content of leukemic cells. When we correlated the proliferative response to exogenous IL-1 beta with treatment outcome in patients with de novo AML, we found the rate of complete remission (CR) to be lower in those with a high proliferative response. We noted a longer duration of CR (p = 0.07) and of survival (p < 0.05) in patients with a low proliferative response. Thus, a high proliferative response to IL-1 beta in the cells of AML patients may indicate a poor prognosis.

Acute Disease↗

PubMed1995

Dissociation between the mitogenic effect and antitumor activity of seed extract from Aeginetia indica L.

The extract from seeds of Aeginetia indica L. (AIL), a parasitic plant, induces potent antitumor immunity against Meth A fibrosarcomas in BALB/c mice. AIL also possesses a thymocyte co-stimulatory effect in vitro with suboptimal dose of Con A, a B cell mitogenic effect, and stimulates AIL-primed CD4+ T cells to produce Th1-type cytokines. In this study, we investigated the relationship between mitogenicity and antitumor activity with AIL. When AIL was analyzed by SDS-PAGE, there was strong and diffuse staining in the region between 14 kDa and the bottom of polyacrylamide gel and it was unaffected when AIL was digested with proteinase K (PK) before SDS-PAGE. Some bands with different molecular mass were also found in silver-stained gel and they disappeared completely by incubating AIL with PK before SDS-PAGE. The in vitro thymocyte co-stimulatory and B cell mitogenic effects were not influenced by digesting AIL with PK but were completely suppressed by the oxidation of AIL with sodium periodate before culture. In contrast, the in vivo antitumor activity was completely abolished by PK, but it was not affected by periodate oxidation. We generated mAbs specific for AIL and investigated the influence on the antitumor activity of AIL in vivo. Around 60-80% of tumor-bearing mice failed to recover from a challenge tumor when they were treated with supernatants isolated from mAb-induced precipitation reactions. Immunoblotting (Western blotting) revealed that all the mAbs reacted exclusively with a 50-60 kDa protein and that this reactivity was not influenced after oxidizing the blots with sodium periodate. We demonstrated that AIL contains polysaccharides and proteins. The polysaccharides induced B cell mitogenic and thymocyte co-stimulatory effects in vitro, while the proteins, especially a 50-60 kDa protein containing non-carbohydrate epitopes recognized by the mAbs, mediated antitumor activity in vivo.

Animals↗

PubMed1995

Early-onset respiratory syncytial virus pneumonia after allogeneic bone marrow transplantation.

A 41-year-old woman with follicular lymphoma developed sporadic respiratory syncytial virus (RSV) pneumonia shortly after allogeneic bone marrow transplantation from an HLA-matched sibling. RSV pneumonia is potentially fatal in immunosuppressed patients, but she improved along with the recovery of bone marrow function without specific treatment. Early recovery of myelosuppression supported by granulocyte colony-stimulating factor may have helped to control RSV pneumonia.

Adult↗

PubMed1995

Cloning and expression of cytochrome P450(11 beta) of porcine adrenal cortex.

Four cDNA clones were isolated from a porcine adrenal gland library by using a bovine cytochrome P450(11 beta) cDNA fragment as a probe. Nucleotide sequences of the four clones overlapped with each other. The deduced amino acid sequences indicated that these clones were derived from a porcine P450(11 beta) cDNA. Consecutive alignment of these clones covered almost 70% of a coding region of the cDNA, but its 5'-terminus was missing. The adrenal mRNA was reverse-transcribed, and polymerase chain reaction was used to obtain a cDNA fragment including the 5'-terminus. A cDNA constructed from this fragment and the isolated four fragments covered the entire apparent open reading frame of the enzyme, which was thus concluded to comprise 503 amino acids including a putative extension peptide of 24 amino acids at the NH2-terminus. The amino acid sequence was 82% identical to that of bovine P450(11 beta)-3. The cDNA was transfected into COS-7 cells, and steroidogenic activity of the cells was measured. The cells not only converted 11-deoxycorticosterone to corticosterone and 18-hydroxycorticosterone, but also produced aldosterone. Thus we conclude that the primary sequence of porcine P450(11 beta) which plays a role in the biosynthesis of glucocorticoids as well as mineralocorticoids was determined.

18-Hydroxycorticosterone↗

PubMed1995

Cytochrome P450(11 beta): structure-function relationship of the enzyme and its involvement in blood pressure regulation.

Cytochrome P450(11 beta) is deeply involved in the final steps of biosynthesis of mineralocorticoids. This paper deals with following issues about this enzyme. (1) The structure and function of the enzymes of various animal species are discussed. By making alignment of amino acid sequences of the enzymes, we identified peptide domains essential for the enzyme actions such as a putative steroid binding domain and a heme binding region. Estimates of molecular similarity among the P450(11 beta) family enzymes suggested that the enzymes having both 11 beta-hydroxylation activity and aldosterone (ALDO) synthetic activity of certain animals such as frog, cattle and pig are more similar to the ALDO synthases of the other animals, such as rat, mouse and human, than the 11 beta-hydroxylases of these animals. (2) The molecular nature of the P450(11 beta) family enzymes of genetically hypertensive rats as well as adrenal regeneration hypertension (ARH) rats is examined. (i) Mutation was found in the P450(11 beta) gene of Dahl's salt-resistant normotensive rat. Steroidogenic activity expressed by the mutated gene accounted well for abnormal plasma levels of steroid hormones in this rat. (ii) 11 beta-, 18- and 19-Hydroxylation activities of adrenal mitochondrial prepared from spontaneously hypertensive rat (SHR), Wistar-Kyoto rat (WKY), and stroke-prone (SP)-SHR were not significantly different from each other. Levels of mRNA of ALDO synthase in adrenal glands of 50-week-old SHR was significantly lower than those of 10-week-old SHR, WKY and SHR-SP. (iii) No significant difference in 19-hydroxylation activity was found between adrenal mitochondria prepared from ARH rat and those from control rat. The level of message of ALDO synthase was lower in adrenal glands of ARH rat.

Aldosterone↗

PubMed1995

Tardy ulnar nerve palsy caused by cubitus varus deformity.

Fifteen patients with tardy ulnar nerve palsy caused by cubitus varus deformity were studied. All patients had a history of previous fracture of the humerus during childhood. The mean interval between fracture and onset of symptoms was 15 years. The severity of the palsy was classified as McGowan's grade I in 12 patients, grade II in 2 patients, and grade III in 1 patient. The mean carrying angle was -2 degrees before surgery. X-ray films showed a shallow ulnar nerve groove, a dysplastic humeral trochlea, medial shift of the ulna, and deformity of the medial epicondyle. The ulnar nerve was explored in all but one patient. Operative findings suggested that the main cause of the palsy was compression by a fibrous band running between the two heads of flexor carpi ulnaris. Surgical steps included release of the fibrous band in 14 patients with anterior subcutaneous transposition of the ulnar nerve in 5 of those patients. A corrective osteotomy was done in 11 patients who requested correction of the varus deformity. Traumatic cubitus varus deformity should be recognized as another cause of cubital tunnel syndrome.

Adolescent↗

PubMed1995

Em18 and Em16, new serologic marker epitopes for alveolar echinococcosis in western blot analysis, are the only two epitopes recognized by commercially available weak positive (cut off) sera for Em2plus-ELISA.

The assay system for antibody responses against Em2, the most specific antigen for serodiagnosis of alveolar echinococcosis (AE), has been established by enzyme-linked immunosorbent assay (ELISA) but not by Western blot assay, since Em2 antigen is not protein but carbohydrate in nature. Recently we reported that previously undescribed protein epitopes, designated Em18 and Em16 due to their molecular weights, were good serologic markers for AE by Western blot analysis. It has been shown that Em18 and Em16 are the only two epitopes recognized by commercially available weak positive (cut off) sera for the Em2plus-ELISA.

Antibodies, Helminth↗

PubMed1995

Mutational and LOH analyses of p53 alleles in colon tumors induced by 1,2-dimethylhydrazine in F1 hybrid mice.

To elucidate the role of p53 in colon tumorigenesis in mice, we examined allele loss and mutational alteration of the p53 gene in colon tumors induced by 1,2-dimethylhydrazine (DMH) in F1 hybrid mice. Intragenic polymorphism of the p53 gene among parental strains enabled us to assess allele loss of the p53 gene and also to determine parental origin of mutated and/or lost alleles. Allele loss was detected in two of 163 tumors heterozygous for the p53 gene. Polymerase chain reaction-single-strand conformation polymorphism analysis of p53 exons 5-8 revealed 33 mutations in 20 of 182 colon tumors, the incidence being lower than that in human colon cancers. The majority of these mutations were of transition type: G:A transitions at non-CpG sites were most prevalent, while those at CpG sites were less common. Distribution of the mutations along p53 amino acid sequence revealed a difference in the location of 'hot spots' between mice and humans. Incidence of p53 alterations did not differ among alleles of different parental origins, suggesting that genetic changes in DMH-induced mouse colon tumors had occurred independently of parental origin and DMH susceptibility. Detailed analysis of p53 mutations on each allele revealed intratumoral heterogeneity in mouse colon tumors. The low incidence of p53 mutations and rare allele loss suggest that p53 alteration plays only a minor role in colon tumorigenesis in mice.

1,2-Dimethylhydrazine↗

PubMed1995

Usefulness of digital rectal examination, serum prostate-specific antigen, transrectal ultrasonography and systematic prostate biopsy for the detection of organ-confined prostate cancer.

The detection rate of organ-confined prostate cancer by digital rectal examination (DRE), serum prostate-specific antigen (PSA), and transrectal ultrasound (TRUS) of the prostate, as well as the value of a directed, guided transrectal core biopsy for the prostate (TRUS-guided biopsy) combined with systematic biopsy, were evaluated. The subjects were 171 patients with urinary symptoms suggestive of prostatic disease excluding those with clinical stage C and D prostate cancer. Twenty-five patients (14.6%) had prostate cancer, 127 (74.2%) had benign prostate hypertrophy, four (2.3%) had prostatic intraepithelial neoplasia, eleven (6.4%) had inflammation, and four (2.3%) had normal prostate tissue. The incidence of detection of hypoechoic findings by TRUS in the patients in whom nodules were detected by DRE or who had elevated serum PSA was higher than that in patients with negative diagnostic findings. In 22 of the 25 patients with prostate cancer, the cancer was detected by recognition of a hypoechoic area on TRUS. In 10 of these 22 patients, prostate cancer was also detected by systematic biopsy in isoechoic areas. Prostate cancer was detected by systematic biopsy in three patients without hypoechoic findings. The positive predictive value for patients with abnormal findings on all three tests was 64.3%, which is significantly higher than that for patients with any other combination of findings (p < 0.05). Our results indicate that the combination of DRE, serum PSA and TRUS is useful for the detection of organ-confined prostate cancer, and that TRUS and TRUS-guided prostate biopsy combined with systematic biopsy should be performed in patients with abnormal findings for both DRE and PSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1995

Endogenous gamma interferon, tumor necrosis factor, and interleukin-6 in Staphylococcus aureus infection in mice.

The production and roles of endogenous gamma interferon (IFN-gamma), tumor necrosis factor (TNF), and interleukin-6 (IL-6) in both lethal and nonlethal infections of Staphylococcus aureus were investigated in mice. In the case of nonlethal infection, although no bacteria were detected in the bloodstreams, bacteria that colonized and proliferated persistently for 3 weeks were found in the kidneys. All mice given lethal injections died within 7 days, and large numbers of bacteria were detected in the bloodstreams, spleens, and kidneys. The first peaks of IFN-gamma, TNF, and IL-6 were observed in the bloodstreams and spleens of the mice with nonlethal and lethal infections within 24 h. Thereafter, in the nonlethal cases, IFN-gamma, TNF, and IL-6 peaked again in the spleens and kidneys during the period of maximum growth of bacteria in the kidneys, although only IL-6 was detected in the sera. In contrast, in the case of lethal infection, the titers of IFN-gamma and IL-6 in the sera and TNF in the kidneys peaked before death. Effects of in vivo administration of monoclonal antibodies (MAbs) against IFN-gamma and TNF on the fates of S. aureus-infected mice were studied. In the nonlethal infections, anti-TNF alpha (anti-TNF-alpha) MAb-treated mice, but not anti-IFN-gamma MAb-treated mice, died as a result of worsening infection, suggesting that endogenous TNF plays a protective role in host resistance to S. aureus infection. In the mice that received lethal doses, injection of anti-TNF-alpha MAb accelerated death. However, although injection of anti-IFN-gamma MAb inhibited host resistance of the infected mice early in infection, most of the animals survived the lethal infection by injection of anti-IFN-gamma MAb, suggesting that endogenous IFN-gamma plays a detrimental role in S. aureus infection. Thus, this study demonstrated that IFN-gamma and TNF play different roles in S. aureus infection.

Animals↗

PubMed1995

Direct enantiomeric separation of platelet-activating factor receptor antagonist SM-10661 by ligand-exchange high-performance liquid chromatography with a copper (II) N,S-dioctyl-D-penicillamine complex.

The enantiomeric separation of SM-10661, a platelet activating factor receptor antagonist, was investigated by HPLC using ligand-exchange chiral stationary phases. The stereoisomers of SM-10661 could all be separated by ligand-exchange HPLC with a Cu(II) N,S-dioctyl-D-penicillamine complex (Sumichiral OA-5000). The mechanism for the resolution includes the involvement of hydrophobic interactions between SM-10661 and Cu(II) D-penicillamine.

Cations↗

PubMed1995

Application of DNA fingerprinting with digoxigenated oligonucleotide probe (CAC)5 to analysis of the genetic variation within Taenia taeniaeformis.

DNA from T. taeniaeformis digested with the restriction endonuclease was hybridized with digoxigenated oligonucleotide probe (CAC)5. Metacestode and adult showed same clear multibanding patterns, which were characteristic of multilocus DNA fingerprinting. The fingerprinting patterns were quite different from those of the rodent hosts. Genetic variations in 4 laboratory-reared isolates of T. taeniaeformis, including 3 isolates which have been reported to be indistinguishable by infectivity, morphology and protein composition of metacestode, were investigated using this technique. Each of the 4 isolates exhibited isolate-specific fingerprinting patterns and were easily distinguished from one another, thus it was considered that (CAC)5 was a highly resolvable and informative probe for cestodes. However, it was also indicated that (CAC)5 was so sensitive that applying fingerprinting with (CAC)5 to taxonomical or phylogenetic analysis was limited where habitat of the host was restricted to the small area. In comparison to fingerprinting with 32P-labeled (CAC)5, fingerprinting with digoxigenated (CAC)5 represented more and sharper bands. It was considered that a digoxigenated probe was more useful for genetic analysis of cestodes.

Animals↗

PubMed1995

The role of the left atrial appendage. A volume loading study in open-chest dogs.

Although the left atrial appendage has a quite unique structure, its function remains unclear. To clarify the function of the left atrial appendage, changes in its anteroposterior, transverse and longitudinal dimensions, and in the anteroposterior dimension of the left atrial body were measured by a sonomicrometer during volume loading in open chest dogs. In the control state, fractional shortening of the transverse dimension of the appendage was greater than that of the atrial body. After dextran infusion, each dimension of the appendage and body, measured just before atrial contraction, increased curvilinearly. The percent increase in appendage dimensions was greater than that of the atrial body dimension (p < 0.05). Systolic shortenings of the appendage increased until mean left atrial pressure reached approximately 15 mmHg but after further pressure elevation, it decreased. In postmortem isolated hearts, the appendage volume was 17.2 +/- 4.4% of the whole left atrial volume. These findings indicate that the appendage has a considerable volume with a greater compliance and assists left ventricular filling during atrial contraction by a Frank-Starling mechanism.

Animals↗