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Biomedical subjects

H Miyamoto

Publications and source records attributed to H Miyamoto.

At least 199 records · Page 11Linked to original sources
PubMed1996

Molecular characterization of the Drosophila Mo25 gene, which is conserved among Drosophila, mouse, and yeast.

To study the general physiological role of the Mo25 gene, which has been cloned from mouse cleavage-stage embryos, we isolated a Drosophila equivalent, dMo25, cDNA from an embryo cDNA library. The 2,222 nucleotides contained a single open reading frame encoding a polypeptide of 339 amino acid residues with a calculated molecular mass of 39,278 daltons. The deduced amino acid sequence of the dMo25 cDNA had 69.3% identity with mouse Mo25. A homology search revealed that these were similar to a protein encoded in an open reading frame near the calcineurin B subunit gene on chromosome XI in Saccharomyces cerevisiae. In particular, the carboxy-terminal region was highly conserved in Drosophila, mouse, and yeast. The dMo25 gene was mapped to the left arm of the third chromosome at 73AB, and 2.3- and 1.8-kb mRNA bands were detected during development and in adult Drosophila. Conservation of the gene structure and the wide expression profile indicated that the function of the gene is likely to be fundamental in many cell types as well as during development.

Amino Acid Sequence↗
PubMed1996

Selective enhancement by tumor necrosis factor-alpha of vascular permeability of new blood vessels induced with agarose hydrogel-entrapped Meth-A fibrosarcoma cells.

We have previously developed a simple and quantitative method for assessment of in vivo tumor cell-induced angiogenesis by means of microencapsulation of tumor cells in agarose hydrogel and mouse hemoglobin ELISA (mHb-ELISA). In this article, we report that the new blood vessels induced with agarose-encapsulated tumor cells have the same sensitivity to tumor necrosis factor-alpha (TNF-alpha) as the original solid-tumor vessels. Agarose beads (average diameter = 200 microns), in which Meth-A fibrosarcoma cells were microencapsulated, were subcutaneously implanted in non-syngeneic ddY mice. Ten days later, extensive angiogenesis was observed on the implanted sites of Meth-A agarose heads, whereas no new blood vessels were induced with cell-free agarose heads. The vascular permeability of the new blood vessels induced with agarose-microencapsulated Meth-A cells was selectively and significantly enhanced by the i.v. injection of TNF-alpha, and it reached the maximum level at 2 h after the injection of TNF-alpha. At 4 h after the injection of TNF-alpha, the vascular permeability was reduced to the basal level. This permeability profile in Meth-A agarose beads in ddY mice is very similar to that in Meth-A solid tumor in syngeneic BALB/c mice. On the other hand, TNF-alpha-treatment did not affect the vascular permeability of other normal tissues or inflammatory tissue in ddY mice. These results strongly suggest that the new blood vessels induced with agarose-microencapsulated tumor cells have the specific characteristics of tumor vessels. Our in vivo angiogenesis assay system should be useful not only to screen anti-angiogenetic agents, but also to elucidate the mechanism of tumor angiogenesis.

Animals↗
PubMed1996

Efficacy and side effects of intermittent recombinant interferon-alpha 2a in chronic aggressive hepatitis C: with or without initial daily administration.

To investigate the therapeutic effect and incidence of side effects of recombinant interferon-alpha 2a (IFN-alpha) in chronic aggressive hepatitis C under stratification by administration mode, a study was conducted by assigning patients to either group A (daily consecutive administration of 9 million units (MU) IFN-alpha for 2 weeks and, thereafter, 3 MU intermittently 3 times weekly for 22 weeks) or group B (exclusively intermittent administration; 9 MU IFN-alpha twice weekly or 6 MU IFN-alpha thrice weekly for 24 weeks). The 28 patients in group A received IFN-alpha for 24 weeks up to a total dose of 324 MU and the 53 patients in group B received the same for 24 weeks up to a total dose of 432 MU. When recovery was defined as the absence of hepatitis C virus (HCV)-RNA 6 months after the completion of treatment, the rate of recovery for group A was 32.1% and that for group B was 37.7%, the latter being higher but without significance. Side effects in groups A and B consisted of leucopenia occupying 14.3 and 7.5%, respectively, and thrombocytopenia occupying 42.9 and 11.3%, respectively; group B exhibited lower values for both side effects. No difference was detected between these groups in other side effects, including pyrexia, generalized malaise, arthralgia or psilosis. Intermittent administration from the outset permitted shortened duration of hospitalization and earlier rehabilitation. Intermittent administration of INF-alpha is required when treating patients with chronic hepatitis C showing lower leucocyte or platelet counts.

Chronic Disease↗
PubMed1996

Spectrum of Legionella species whose intracellular multiplication in murine macrophages is genetically controlled by Lgn1.

We examined the intracellular growth of 20 strains within six species of Legionella in thioglycolate-elicited peritoneal macrophages from A/J and C57BL/6 mice and a congenic strain derived from them (A.B Lgn1). With the exception of Legionella pneumophila Togus-1 and Bloomington-2, the intracellular growth of the 15 L. pneumophila strains tested was controlled by Lgn1. However, the intracellular growth of five Legionella species other than L. pneumophila was not under Lgn1's control.

Animals↗
PubMed1996

The streptozocin-diabetic state depresses saliva secretion stimulated by pilocarpine and noradrenaline in mice.

We investigated the influence of the streptozocin (STZ)-diabetic state on the dose-response curves for salivary flow and protein content in saliva stimulated by pilocarpine and noradrenaline in mice. The diabetic state increased the relative weights of parotid and sublingual salivary glands but not the weight of submandibular glands, despite body weight loss. In the dose-response curves, (1) the maximal responses to stimulation with pilocarpine and noradrenaline on salivary flow, and with noradrenaline on protein content in saliva, were depressed by the diabetic state, and (2) the value of the 50% effective dose for salivary flow with pilocarpine, but not with noradrenaline, was decreasingly altered by diabetic mice. These results suggest that xerostomia, one of the complications of non-insulin-dependent diabetes mellitus, is caused in part by muscarinic and adrenergic receptor dysfunction in the salivary glands.

Animals↗
PubMed1996

Effects of the mycelial extract of cultured Cordyceps sinensis on in vivo hepatic energy metabolism in the mouse.

Mice were given the extract of cultured Cordyceps sinensis (Cs) (200 mg/kg daily, p.o.) for 3 weeks. In vivo phosphorus-31 nuclear magnetic resonance (NMR) spectra of the liver were acquired at weekly intervals using a surface coil. From 1 to 3 weeks, a consistent increase in the ATP/inorganic phosphate ratio, which represents the high energy state, was observed in the Cs extract-treated mice. The intracellular pH of the Cs extract-treated mice was not significantly different from that of the control mice. No steatosis, necrosis, inflammation or fibrosis were observed in the liver specimens from Cs extract-treated mice.

Adenosine Triphosphate↗
PubMed1996

Loss of heterozygosity at the p53, RB, DCC and APC tumor suppressor gene loci in human bladder cancer.

PURPOSE: Allelic losses within several tumor suppressor genes have been detected frequently in various types of human cancer. We investigated the roles and possible interactions of the tumor suppressor genes p53, Rb, DCC and APC in bladder cancer. MATERIALS AND METHODS: Loss of heterozygosity (LOH) of these 4 genes was examined in 45 human bladder cancers by polymerase chain reaction and restriction fragment length polymorphism assay. RESULTS: Of the evaluated cases, LOH was seen at P53 in 38%, at Rb in 22%, at DCC in 36% and at APC in 6% of tumors. Loss of heterozygosity at p53 and Rb was predominantly observed in high grade (grade 3) and/or invasive (T2 or greater) tumors, whereas LOH at DCC was present irrespective of tumor grade and stage. Allelic losses at either p53, Rb, DCC or APC were seen in 82% of high grade tumors, but in only 21% of low grade (grade 1 and 2) tumors (p<0.005). Similarly, 71% of invasive tumors had LOH at one or more loci compared with 20% of superficial (Ta and T1) tumors (p<0.005). Interestingly, p53-LOH and Rb-LOH were often observed simultaneously in the same tumor. CONCLUSIONS: These results suggest that loss of the p53, Rb and/or DCC genes is involved in most of the late and some of the early steps of bladder carcinogenesis.

Base Sequence↗
PubMed1996

[Questionnaire survey of AIDS examination recipients at government-run public health center regarding AIDS awareness promotion and HIV examinations].

An anonymous questionnaire survey was conducted among persons who had undergone screening for AIDS at public health centers under the auspices of 7 local government bodies (Hokkaido, Metropolitan Tokyo, Aichi Prefecture, Osaka Prefecture, Kobe City, Saga Prefecture, Okinawa Prefecture). There were 1,230 replies, for a response rate of 46.8%. Questions in the survey pertained to general knowledge of AIDS, information desired by the recipients, desired ways to foster awareness, and a desirable examination system. A comparison was made in terms of gender, marriage status (married, single) and age (less than 40 years of age, more than 40 years of age), respectively. The survey results were as follows. 1. Concerning the infection route, accurate response rate was low with regard to the mother-child infection, mosquito transmission, and use of contaminated needles. 2. Desired methods to promote AIDS awareness expressed among replies were given in the following order or frequency: "information via radio and TV," "spread of knowledge through telephone consultation," and "holding an AIDS Week or similar kinds of campaigns." 3. Information sought by respondents frequently included AIDS treatment, pathology, and spread. This trend was most obvious among those under 40 years of age. 4. As for the AIDS examination system, replies most often reflected the hope that the examination site would be the Public Health Center, the charge would be gratis, and that one could be examined at night during the week, and on days off. 5. For those undergoing examination where there was no actual concern of possibility of HIV infection, single persons, accounted for around 80% of the overall. 6. More than half of those who had been examined mentioned having experienced concerns about maintaining confidentiality at the time they were examined.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Helicobacter pylori infection in childhood: H. pylori isolation rate in gastric juice in relation to positive serum antibody rates.

We investigated the prevalence of Helicobacter pylori infection by isolation of H. pylori and by antibody detection in the serum of Japanese children. The children were distributed into four groups by age: group I, under 1 year; group II, 1-5 years; group III, 6-11 years; and group IV, 12-15 years. For the isolation of H. pylori, gastric juice was obtained from 115 children from middle class families. In the 103 samples obtained from asymptomatic children, H. pylori was not isolated in any from group I. The isolation rate in groups II, III, and IV was 3% (1/32), 20% (5/25), and 75% (3/4), respectively. In symptomatic children, H. pylori was isolated only in group IV (66.7%). The antibody positive rate in group I, II, III, and IV was 13% (6/47), 10% (11/112), 18% (16/89), and 26% (11/43), respectively, in asymptomatic children. In group I, however, 4 of 25 samples (18%) were obtained from babies under 3 months of age; this result was regarded as reflecting maternal antibodies. Nineteen samples were obtained from children with hepatitis A who lived in Nanki hospital for handicapped children, where hygiere was poor. The antibody positive rate in this population was 60% (3/5) in group III and 90% (9/10) in group IV. These results suggest that H. pylori infection in Japanese children is related to age and hygiene conditions. The antibody positive rate was similar to that reported in other countries.

Adolescent↗
PubMed1996

Telomerase activity in human bladder cancer.

Telomerase can synthesize telomeric DNA repeats onto chromosome ends. Telomere length and telomerase activity have recently been implicated in the control of the proliferative capacity of normal and malignant cells. The expression of telomerase activity is concomitant with the attainment of immortality in tumor tissues and cells. Thus, enzyme activity may indicate a prevalent or even ubiquitous tumor producer. In this report, telomerase activity was analyzed in 40 human bladder cancers, 7 normal tissues, and 2 bladder epithelia with dysplasia using a PCR-based telomeric repeat amplification protocol assay. Telomerase activity was detected in almost all bladder tumors (97.5%); only one sample, which was in an early stage, did not express telomerase activity. None of the normal tissues displayed telomerase activity. One of the two bladder epithelia with dysplasia expressed low telomerase activity. The expression of telomerase activity has a clear association with the pathological grade and clinical stage. Most of the tumors with high telomerase activity were in an advanced grade and had deep invasion. Thus, telomerase activity might be suggested to represent an additional required event in the multigenetic process of tumorigenesis in human bladder cancer.

Humans↗
PubMed1995

Decreased capacity of aged mice to produce interferon-gamma in Legionella pneumophila infection.

We investigated the difference in natural resistance to Legionella pneumophila infection between aged (18-20-month-old) and young (3-month-old) mice of ddY strain. Aged mice were more susceptible to the bacterial infection than young mice; 50% lethal doses of L. pneumophila for aged and young mice were 2.2 x 10(7) and 8.5 x 10(7) colony forming units (CFU), respectively, after intraperitoneal injection of the bacteria. The bacterial burden in the livers was larger in aged than young mice after a challenge with a sublethal dose of L. pneumophila. However, peritoneal macrophages of aged mice paradoxically had a greater capacity to kill intracellular L. pneumophila than those of young mice. Interferon-gamma (IFN-gamma) production from naive spleen cells was compared after an in vitro stimulation with formalin-killed L. pneumophila. Spleen cells of aged mice produced significantly less IFN-gamma than those of young mice. When anti-murine IFN-gamma monoclonal antibody was administered before the bacterial infection, the subsequent bacterial burden in the livers significantly increased in young but not in aged mice. These data suggest that, in aged mice, IFN-gamma production is depressed at an early phase of L. pneumophila infection and it renders aged mice more susceptible to the infection.

Aging↗
PubMed1995

Female reproductive properties and prenatal development of a senescence-accelerated mouse strain.

Female reproductive properties, early embryonic development, and serum estradiol and progesterone levels of the senescence-accelerated mouse (SAM)-prone (SAM-P) strain were compared with those of a SAM-resistant (SAM-R) strain. The reproductive life span of SAM-P (from 11.4 to 25.0 weeks old) was shorter than that of SAM-R (11.1 to 41.6 weeks old), and the total number of SAM-P pups was 41.7% less than from SAM-R. The reproductive senescence of SAM-P is more accelerated than that of SAM-R. At 15 weeks old, the maximum litter size of SAM-P was noted and was 33.7% smaller than that of SAM-R. Although no differences in the numbers of ovulated and fertilized ova were observed between two strains, the number of implants in SAM-P was 21.6% less than in SAM-R. Cell cleavage was delayed in embryos of SAM-P (8% morula, at day 2 of pregnancy) compared to SAM-R (48%). At day 3 of pregnancy, 9% and 33% of the embryos were blastocysts in SAM-P and SAM-R, respectively. At day 1 of pregnancy, serum estradiol level in SAM-P was 18.2% higher than in SAM-R, whereas the serum progesterone level in SAM-P was 46.2% lower than in SAM-R. The unbalance of estradiol and progesterone levels in SAM-P was considered to be the cause of the delay in early embryonic development, and then the decrease of implantation and a smaller litter size.

Aging↗
PubMed1995

Expression of transforming growth factor-beta 1 in human bladder cancer.

BACKGROUND: Elevated expression of transforming growth factor-beta 1 (TGF-beta 1) has been reported in several types of human cancer. However, the significance of TGF-beta 1 expression in clinical bladder cancer is not well known. METHODS: The levels of TGF-beta 1 expression were quantitated using a polymerase chain reaction-based method in tissue specimens obtained from 51 patients with bladder cancer. RESULTS: Transforming growth factor-beta 1 expression in bladder cancer was higher than that found in normal bladder epithelium (P < 0.01). Significantly higher levels of TGF-beta 1 transcripts were observed in low and intermediate grade (Grade 1 and 2) tumors than in high grade (Grade 3) tumors (P < 0.02). Superficial (pTa and pT1) tumors had higher levels of TGF-beta 1 than invasive (pT2 or higher) tumors (P < 0.05). CONCLUSIONS: These results suggest that enhanced expression of TGF-beta 1 is specific to low grade and stage bladder cancer. Transforming growth factor-beta 1 may play an important role in the early stages of human bladder cancer development, and TGF-beta 1 expression could provide a new relevant tumor marker for determining tumor progression in patients with bladder cancer.

Actins↗
PubMed1995

canoe encodes a novel protein containing a GLGF/DHR motif and functions with Notch and scabrous in common developmental pathways in Drosophila.

The canoemisty1 (cnomis1) mutation was isolated by virtue of its severe rough eye phenotype from approximately 500 fly lines, each harboring a single autosomal insertion of a P element (Bm delta w). Excision of the P element generated a lethal, null allele, cnomis10, together with many revertants with normal eye morphology. Ommatidia homozygous for cnomis10, produced in an otherwise wild-type eye by somatic recombination, typically contain a reduced number of outer photoreceptors. Some cnomis1 homozygous adults bear extra macrochaetes on the head, notum, humerus and/or scutellum. cnomis1 hemizygotes often show conspicuous wing phenotypes such as a notched blade and the loss of a cross vein. The sequence of cno cDNA clones isolated from an embryonic cDNA library revealed a long open reading frame that potentially encodes a 1893-amino-acid protein with the GLGF/DHR motif, a conserved sequence in Discs large, Dishevelled, and some other proteins associated with cellular junctions. Flies doubly mutant for cnomis1 and scabrous1 (sca1) and those for cnomis1 and the split (spl) allele of Notch (N) always have rumpled wings curved downward. The spl; cnomis1 double mutant flies also exhibit a "giant socket" phenotype. These phenotypes are rarely observed flies singly mutant for either cnomis1, sca1 or spl. The wing vein gaps caused by Abruptex1, a N allele producing an activated form of N protein, are dominantly suppressed by cnomis1. Heterozygosity for shaggy and myospheroid promotes formation of extra wing veins in cnomis1 homozygotes. The genetic interactions suggest that cno participates with members of the N pathway in regulating adhesive cell-cell interactions for the determination of cell fate.

Amino Acid Sequence↗
PubMed1995

Structural changes in the oviductal wall during passage of unfertilized cumulus-oocyte complexes in mice.

BACKGROUND: Little information is available on the structural relationship of cumulus-oocyte complexes and the oviductal wall during the transport of cumulus-oocyte complexes. METHODS: To this end, morphological changes of the oviductal wall during the passage of unfertilized cumulus-oocyte complexes were examined chronologically in ICR mice 25-27 days of age injected with PMSG and hCG. Mice were sacrificed at 12, 14, 16, 18, and 24 hr after the injection of hCG to remove oviducts, and the height of mucosal folds, muscle layers, and epithelial cells was measured in the serial sections stained with hematoxylineosin or colloidal iron. RESULTS: The height of the mucosal fold and muscle layer where cumulus-oocyte complexes were located was less than that of the adjacent portions. At 12-18 hr of hCG injection (approximately 2-8 hr after ovulation), the ova with surrounding cumulus cells lie free in a wide lumen, and the muscular tissue consists of only 2 or 3 layers of cells, arranged mostly longitudinally. However, a neighboring portion without cumulus-oocyte complexes, where the folds meet in the middle, appreciably restricts the free space in the lumen. After 24 hr of hCG administration, structural changes in the oviductal wall, where cumulus-oocyte complexes were located, were no longer apparent. The number of cumulus cells surrounding the oocyte decreased during the passage through the oviduct. At 12-18 hr after hCG injection, approximately 140 cells were identified in the largest cross section of a cumulus-oocyte complex, but after 24 hr of hCG administration (approximately 14 hr after ovulation), an oocyte was surrounded with only approximately 25 cells. CONCLUSIONS: These results indicate that oocyte-cumulus cell complexes influence the structure of the oviductal wall during the passage in the oviduct.

Animals↗
PubMed1995

Structural changes in the oviductal wall during the passage of unfertilized cumulus-oocyte complexes in mice.

BACKGROUND: Little information is available on the structural relationship of cumulus-oocyte complexes and the oviductal wall during the transport of cumulus-oocyte complexes. Then, morphological changes of the oviductal wall during the passage of unfertilized cumulus-oocyte complexes was examined chronologically in ICR mice 25-27 days of age injected with PMSG and hCG. METHODS: Mice were sacrificed at 12, 14, 16, 18, and 24 hr after the injection of hCG to remove oviducts, and the height of mucosal folds, muscle layers, and epithelial cells were measured in the serial sections stained with hematoxylin-eosin or colloidal iron. RESULTS: The height of the mucosal fold and muscle layer where cumulus-oocyte complexes were located was less than that of the adjacent portions. At 12-18 hr of hCG injection (about 2-8 hr after ovulation), the ova with surrounding cumulus cells lie free in a wide lumen, and the muscular tissue consists of only 2 or 3 layers of cells, arranged mostly longitudinally. However, a neighboring portion without cumulus-oocyte complexes, where the folds meet in the middle, appreciably restricts the free space in the lumen. After 24 hr of hCG administration, structural changes in the oviductal wall, where cumulus-oocyte complexes were located, were no longer apparent. The number of cumulus cells surrounding the oocyte decreased during the passage through the oviduct. At 12-18 hr after hCG injection, about 140 cells were identified in the largest cross section of a cumulus-oocyte complex, but, after 24 hr of hCG administration (about 14 hr after ovulation), an oocyte was surrounded with only about 25 cells. CONCLUSIONS: These results indicate that oocyte-cumulus cell complexes influence the structure of the oviductal wall during the passage in the oviduct.

Animals↗
PubMed1995

Tumor suppressor gene p53 mutations in human prostate cancer.

The genetic background underlying the growth and development of human prostatic cancer is not yet clear. Here we searched for possible mutations in the entire coding region of tumor suppressor gene p53 in primary human prostatic carcinomas, using polymerase chain reaction and single-strand conformational polymorphism analysis of RNA. We found p53 gene mutations in 4 of 21 cases (19%). DNA sequencing of the polymerase chain reaction products revealed missense point mutations that resulted in amino acid changes in exon 5 or 3 in three cases and single base deletions in exon 7 in two cases. One case contained both a missense point mutation and a single base deletion. Three of these four cases were pathologically diagnosed as poorly differentiated adenocarcinomas, and three of the four cases were clinically localized to stage C or D. None of seven noncancerous prostate tissues nor three well-differentiated adenocarcinoma tissues showed any mutations. The present results suggest that p53 gene mutation is involved in the late progression steps of human prostate carcinogenesis.

Adenocarcinoma↗