Biomedical subjects

M Hirai

Publications and source records attributed to M Hirai.

At least 37 records · Page 2Linked to original sources

PubMed2003

Gene arrangement at the Rhesus blood group locus of chimpanzees detected by fiber-FISH.

The Rhesus (Rh) blood group system in humans is encoded by two genes with high sequence homology. These two genes, namely, RHCE and RHD, have been implied to be duplicated during evolution. However, the genomic organization of Rh genes in chimpanzees and other nonhuman primates has not been precisely studied. We analyzed the arrangement of the Rh genes of chimpanzees (Pan troglodytes) by two-color fluorescence in situ hybridization on chromatin DNA fibers (fiber-FISH) using two genomic DNA probes that respectively contain introns 3 and 7 of human RH genes. Among the five chimpanzees studied, three were found to be homozygous for the two-Rh-gene type, in an arrangement of Rh (5'-->3') - Rh (3'<--5'). Although a similar gene arrangement can be detected in the RH gene locus of typical Rh-positive humans, the distance between the two genes in chimpanzees was about 50 kb longer than that in humans. The remaining two chimpanzees were homozygous for a four-Rh-gene type, in an arrangement of Rh (5'-->3') - Rh (3'<--5') - Rh (3'<--5') - Rh (3'<--5') within a region spanning about 300 kb. This four-Rh-gene type has not been detected in humans. Further analysis of other great apes showed different gene arrangements: a bonobo was homozygous for the three-Rh-gene type; a gorilla was heterozygous for the one-Rh- and two-Rh-gene types; an orangutan was homozygous for the one-Rh-gene type. Our findings on the intra- and interspecific genomic variations in the Rh gene locus in Hominoids would shed further light on reconstructing the genomic pathways of Rh gene duplication during evolution.

Animals↗

PubMed2002

Urinary excretion of 8-oxo-7, 8-dihydro-2'-deoxyguanosine as a predictor of the development of diabetic nephropathy.

AIMS/HYPOTHESIS: The increased oxidative stress in diabetes is known to contribute to the progression of diabetes and its complications. We have reported a significant relation between the content of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a product of oxidative DNA damage in urine or leukocytes and the severity of diabetic nephropathy and retinopathy [1]. We investigated whether 8-oxodG in urine or leukocytes is associated with the progression of diabetic nephropathy. METHODS: We measured urinary 8-oxodG contents at entry and carried out a prospective longitudinal study to assess the progression of nephropathy over 5 years. RESULTS: There was a significant progression of diabetic nephropathy in the patients with higher excretion of 8-oxodG in urine compared with the patients with moderate or lower excretion of 8-oxodG. There was no significant association between the leukocyte 8-oxodG contents and the development of nephropathy. The multivariate logistic regression analysis suggests that the urinary 8-oxodG was the strongest predictor of nephropathy among several known risk factors. CONCLUSION/INTERPRETATION: This study provides evidence that increased oxidative stress has a primary role in the pathogenesis of diabetic nephropathy. A local enhancement of oxidative stress in diabetic kidney might explain the possible linkage between the increased urinary excretion of 8-oxodG and the development of nephropathy. 8-oxodG in urine is a useful clinical marker to predict the development of diabetic nephropathy in diabetic patients.

Age of Onset↗

PubMed2002

A locust DNA-binding protein involved in gene regulation by juvenile hormone.

Although juvenile hormone (JH) has essential roles in insect development and reproduction, the molecular mechanisms of gene regulation by JH remain an enigma. In Locusta migratoria, the partially palindromic 15-nt sequence, GAGGTTCGAG(A)/(T)CCT(T)/(C), found upstream of a JH-induced gene, jhp21, was designated as a putative juvenile hormone response element (JHRE). When JH-deprived adult female locusts were treated with the active JH analog, methoprene, a fat body nuclear factor that bound specifically to JHRE appeared after 24 h. Binding exhibited a preference for an inverted repeat with GAGGTTC in the left half-site, a single nucleotide spacer, and a right half-site in which some variation is acceptable. Binding to JHRE was abolished by phosphorylation catalyzed by a C-type protein kinase present in the nuclear extracts. The DNA-binding protein is thus believed to be a transcription factor, which is brought to an active state through the action of JH and then participates in the regulation of certain JH-dependent genes.

Animals↗

PubMed2002

Adjuvant chemotherapy in stage I uterine endometrial carcinoma.

OBJECTIVE: We have assessed prognostic factors and the efficacy of adjuvant chemotherapy in stage I uterine endometrial carcinoma. METHODS: 251 primary surgically treated stage I patients were studied. Prognostic factors were evaluated and 5-year and 10-year survival rates were compared in patients with lymph-vascular space invasion to investigate whether adjuvant chemotherapy improves survival. RESULTS: The overall 5-year and 10-year survival rates were 94% and 93%. Multivariate analysis indicates that lymph-vascular space invasion is the most significant prognostic factor in both 5- and 10-year survival rates (P<0.001 at both times) and stage/depth of invasion is significant for the 10-year survival rate (P=0.04). Of 54 patients with lymph-vascular space invasion, statistically significant differences were observed in 10-year survival rate (P=0.02) between patients who had surgery followed by adjuvant chemotherapy (n=23) and patients who had surgery alone (n=31). Toxicities were mild to moderate (30%). CONCLUSIONS: The clinical importance of lymph-vascular space invasion and the efficacy of adjuvant chemotherapy were confirmed. This observation warrants a larger comparative study with adjuvant chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

cDNA cloning and characterization of Bombyx mori juvenile hormone esterase: an inducible gene by the imidazole insect growth regulator KK-42.

The insect growth regulator (IGR) imidazole KK-42 induces hemolymph juvenile hormone esterase activity and precocious metamorphosis in Bombyx mori. As an initial step to understand the molecular action of KK-42, we isolated a full-length of juvenile hormone esterase cDNA from B. mori (BmJHE). The deduced amino acid sequence of BmJHE showed high identity to JHEs of Heliothis virescens (54%) and Choristoneura fumiferana (52%). Recombinant BmJHE protein expressed in the baculovirus expression system hydrolyzed 3H-JH III and JH analog, HEPTAT, indicating that BmJHE cDNA encodes functional JH esterase. Northern blot analysis showed that the BmJHE transcript was present predominantly in the fat body at the beginning of the last larval instar. During this instar, BmJHE transcript increased gradually until day 7, then decreased, and increased again on day 10 in the fat body. This temporary expression pattern was similar to that of JHE enzyme activity in hemolymph. In contrast, in the 4th instar, the BmJHE transcript was present in the fat body even though hemolymph JHE activity was very low. Western blot analysis using anti-BmJHE antiserum showed BmJHE protein was present in hemolymph during the 5th instar but not during the 4th instar. These results indicate that BmJHE protein is secreted into hemolymph at the metamorphic stage. Hemolymph JHE activity was high in precociously metamorphosed 4th instar larvae (treated KK-42) but low in normal 4th and extra-molted 6th instar larvae (fed 20E). KK-42-treated larvae showed high expression level of BmJHE transcript in the fat body, suggesting that KK-42 enhances BmJHE gene expression in the fat body.

Amino Acid Sequence↗

PubMed2002

cDNA cloning, functional expression and characterization of kynurenine 3-hydroxylase of Anopheles stephensi (Diptera: Culicidae).

Kynurenine 3-hydroxylase (K3H) is a NADPH-dependent flavin monooxygenase involved in the tryptophan pathway. Xanthurenic acid (XA) is a metabolite of this pathway and has recently been identified as a gamete activating factor (GAF) of the malarial parasite. We cloned K3H cDNA from Anopheles stephensi (AsK3H), because anopheline mosquitoes are a vector of the human malaria parasite, Plasmodium falciparum and the catalytic function of AsK3H in XA production. Recombinant AsK3H protein was expressed in Sf-9 cells using the baculovirus system and its enzymatic properties were characterized. The specific activities of crude cell lysate and affinity purified protein were 94.9 +/- 6.2 and 865.6 +/- 10.5 nmol/min/mg protein, respectively. The optimum pH of AsK3H was 7.0. Analysis of AsK3H gene expression using RT-PCR revealed that AsK3H was constitutively expressed in egg, larva, pupa and adult.

Amino Acid Sequence↗

PubMed2002

Ventricular activation and recovery measured in electrocardiographic limb leads correlate with measurements from specific areas in body surface mapping.

AIMS: Dispersion of ventricular depolarization-repolarization in 12-lead electrocardiograms (ECGs) has been reported to provide noninvasive information on arrhythmogenicity. However, there are two methods to calculate the dispersion from ECGs including and excluding limb leads. The aim of this study was to examine whether temporal parameters from limb leads represent activation and repolarization of a particular part of the body surface. METHODS AND RESULTS: We compared the temporal parameters of activation time (AT), activation-recovery interval (ARI), and recovery time (RT) from limb leads of ECGs with those from an 87-lead body surface maps. The study population consisted of 50 normal subjects (25 men and 25 women, 19.4 +/- 1.6 years). The temporal parameters in leads I, II, and III were highly (r > 0.9) correlated with those in unipolar leads over the left lateral, left lower, and right lower chest, respectively. The temporal parameters in leads aVR, aVL, and aVF showed a significant correlation (r > 0.8) with those in unipolar leads over the right upper, left upper, and lower anterior chest, respectively. The mean AT, ARI, and RT from each limb lead of ECG were almost the same as those of unipolar leads over the corresponding areas of the body surface. CONCLUSIONS: These findings suggest that ATs, ARIs, and RTs from limb leads may represent those from unipolar leads of particular areas over the body surface in normal subjects. The temporal parameters from limb leads of ECGs may provide information on activation and repolarization as well as the precordial leads of ECGs.

Adolescent↗

PubMed2002

Combined surgical and intraoperative endovascular approach for a giant internal carotid artery aneurysm in the high cervical region.

For the obliteration of a large aneurysm located at the cranial base or high cervical region, several therapeutic strategies including a parent vessel ligation, and endovascular occlusion have been reported, because it is difficult to access the aneurysm itself. We used a combined surgical and endovascular approach for the treatment of a large internal carotid artery aneurysm in the high cervical region. In the present case, we performed superficial temporal artery to middle cerebral artery bypass, then obliterated the aneurysm with distal coil embolization and proximal ligation in one session, using portable digital subtraction angiography. The combined endovascular and surgical approach involves less invasive surgery for complex cerebrovascular lesions.

Aged↗

PubMed2001

Characterization and identification of exflagellation-inducing factor in the salivary gland of Anopheles stephensi (Diptera: Culicidae).

Gamete activation factor (GAF) induces exflagellation of Plasmodium microgametes. We found GAF in the salivary glands of female mosquitoes, Anopheles stephensi. The exflagellation was induced in a concentration-dependent manner in the supernatant of salivary gland's crude homogenate. The exflagellation-inducing activity in the salivary gland was higher than that in the midgut and the head. GAF in the salivary glands was found to be heat stable and low molecular weight (<3000 molecular weight). Analysis of the supernatant by capillary electrophoresis and UV absorbance profile showed that the salivary glands contained xanthurenic acid, which was previously identified as GAF in the head of A. stephensi. The exflagellation-inducing activity in the salivary gland declined immediately after a blood meal, implying that GAF was in the saliva, and was delivered into the midgut together with the blood and induced exflagellation in the midgut.

Animals↗

PubMed2001

Assignment of 118 novel cDNAs of cynomolgus monkey brain to human chromosomes.

In order to isolate genes that may not be represented in current human brain cDNA libraries, we have sequenced about 20,000 sequence tags of cDNA clones derived from cerebellum and parietal lobe of cynomolgus monkeys (Macaca fascicularis). We determined the entire cDNA sequence of approximately 700 clones whose 5'-terminal sequences showed no homology to annotated putative genes or expressed sequence tags in current databases of genetic information. From this, 118 clones with sequences encoding novel open reading frames of more than 100 amino acid residues were selected for further analysis. To localize the genes corresponding to these 118 newly identified cDNA clones on human chromosomes, we performed a homology search using the human genome sequence and fluorescent in situ hybridization. In total, 108 of 118 clones were successfully assigned to specific regions of human chromosomes. This result demonstrates that genes expressed in cynomolgus monkey are highly conserved throughout primate evolution, and that virtually all had human homologs. Furthermore, we will be able to discover novel human genes in the human genome using monkey homologs as probes.

Animals↗

PubMed2001

Molecular cloning and characterization of WNT3A and WNT14 clustered in human chromosome 1q42 region.

Human WNT3A and WNT14 cDNAs were cloned and characterized. WNT3A and WNT14 encoded WNT family protein of 352 and 365 amino acids, respectively. The 3.0-kb WNT3A mRNA was moderately expressed in placenta, and the 4.4-kb WNT14 mRNA was moderately expressed in skeletal muscle and heart. Although WNT3A mRNA was not detected in 35 human cancer cell lines, WNT14 mRNA was expressed in gastric cancer cell lines TMK1, MKN7, MKN45 and KATO-III. WNT3A and WNT14 genes, clustered in the head to head manner with an interval of about 58.0 kb, were mapped to human chromosome 1q42 region by fluorescence in situ hybridization. WNT3 and WNT15, clustered in human chromosome 17q21 region, are related genes of WNT3A and WNT14, respectively. WNT3A-WNT14 gene cluster and WNT3-WNT15 gene cluster might be generated due to duplication of ancestral gene cluster, just like WNT10A-WNT6 gene cluster and WNT10B-WNT1 gene cluster. Integration sites of mouse mammary tumor virus (MMTV) are located in the mouse chromosomal regions corresponding to these human WNT gene clusters. These results strongly suggest that unidentified nucleotide motif responsible for susceptibility to recombination might exist within the intergenic regions of these WNT gene clusters.

Amino Acid Sequence↗

PubMed2001

The YXXQ motif in gp 130 is crucial for STAT3 phosphorylation at Ser727 through an H7-sensitive kinase pathway.

The signal transducer and activator of transcription (STAT) 3 is essential for mediating signals from the receptors for a variety of cytokines and growth factors, including IL-6 and EGF, and from cytoplasmic tyrosine kinases. Upon stimulation, STAT3 is phosphorylated at Ser727 and Tyr705. However, the role of phosphorylation at Ser727, and the kinase pathways responsible for this phosphorylation in IL-6 signaling remain obscure. Here we show that IL-6 activates at least two distinct STAT3 serine kinase pathways and that an H7-sensitive pathway is dominant over a PD98059-sensitive one in HepG2 cells stimulated with a low concentration of IL-6. The analysis, using a series of chimeric receptors containing the extracellular domain of the G-CSF receptor, the truncated form of gp 130, and additional short peptides at the gp 130 carboxy-terminus, showed that the YXXQ motif of gp 130 was sufficient for the H7-sensitive STAT3 Ser727 phosphorylation. This YXXQ-mediated pathway does not involve Erk, p38, JNK, or PKCdelta, and requires a site in the region from 533 to 711 of STAT3 for phosphorylation in vivo. Moreover, we show that Ser727 is required for full transcriptional activity of STAT3 for two different response elements. Thus, the YXXQ motif regulates STAT3 activities in two ways in response to even a low concentration of IL-6: it recruits STAT3 to the receptor for tyrosine phosphorylation, and activates an unidentified H7-sensitive pathway leading to the serine phosphorylation of STAT3.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2001

Genomic and spectral analyses of long to middle wavelength-sensitive visual pigments of common marmoset (Callithrix jacchus).

The genetic basis of red-green color vision of common marmoset (Callithrix jacchus) is not fully understood. Here, we have cloned and characterized the three alleles at a locus that encode the long to middle wavelength-sensitive (LWS/MWS) visual pigments of this species. Using in situ hybridization, we localized this locus to the telomeric region of the long arm of X chromosome. The three visual pigments achieve the wavelengths of maximal absorption at 561, 553, and 539 nm and fully explain the red-green color vision of the common marmoset. The 'tri-allelic single-locus X-chromosome' model operates under the unique phenomenon, known as blood chimerism.

Animals↗

PubMed2001

A novel superoxide-producing NAD(P)H oxidase in kidney.

During phagocytosis, gp91(phox), the catalytic subunit of the phagocyte NADPH oxidase, becomes activated to produce superoxide, a precursor of microbicidal oxidants. Currently increasing evidence suggests that nonphagocytic cells contain similar superoxide-producing oxidases, which are proposed to play crucial roles in various events such as cell proliferation and oxygen sensing for erythropoiesis. Here we describe the cloning of human cDNA that encodes a novel NAD(P)H oxidase, designated NOX4. The NOX4 protein of 578 amino acids exhibits 39% identity to gp91(phox) with special conservation in membrane-spanning regions and binding sites for heme, FAD, and NAD(P)H, indicative of its function as a superoxide-producing NAD(P)H oxidase. The membrane fraction of kidney-derived human embryonic kidney (HEK) 293 cells, expressing NOX4, exhibits NADH- and NADPH-dependent superoxide-producing activities, both of which are inhibited by diphenylene iodonium, an agent known to block oxygen sensing, and decreased in cells expressing antisense NOX4 mRNA. The human NOX4 gene, comprising 18 exons, is located on chromosome 11q14.2-q21, and its expression is almost exclusively restricted to adult and fetal kidneys. In human renal cortex, high amounts of the NOX4 protein are present in distal tubular cells, which reside near erythropoietin-producing cells. In addition, overexpression of NOX4 in cultured cells leads to increased superoxide production and decreased rate of growth. The present findings thus suggest that the novel NAD(P)H oxidase NOX4 may serve as an oxygen sensor and/or a regulator of cell growth in kidney.

Adult↗

PubMed2001

Expression of vascular endothelial growth factors (VEGF-A/VEGF-1 and VEGF-C/VEGF-2) in postmenopausal uterine endometrial carcinoma.

OBJECTIVE: We investigated the expression of two angiogenic vascular endothelial growth factors, VEGF-A/VEGF-1 and VEGF-C/VEGF-2, in 228 cases of uterine endometrial carcinomas from postmenopausal patients to evaluate the correlation with histopathologic features and clinical outcome. METHODS: Immunohistochemistry was used to assess VEGF-A/VEGF-1 and VEGF-C/VEGF-2 expression in 228 primary surgically treated cases of postmenopausal endometrial carcinomas and the results were statistically analyzed in relation to vascular invasion, depth of invasion (myometrial vs serosal-parametrial invasion), lymphatic vessel invasion, lymph node metastasis, disease-free 5-year survival rate (DF5YR), and disease-free 10 year-survival rate (DF10YR). RESULTS: The results of univariate analysis showed that VEGF-A/VEGF-1 and VEGF-C/VEGF-2 expression correlated with vascular invasion (P < 0.0001, P = 0.0006), depth of invasion (P = 0.0004, P = 0.043), lymphatic vessel invasion (P = 0.021, P < 0.0001), lymph node metastasis (P = 0.0017, P = 0.0008), DF5YR (P = 0.0081, P = 0.0002), and DF10YR (P = 0.0077, P = 0.0001). Multivariate analysis showed that lymph node metastasis (P = 0.0017, P = 0.0008), parametrial-serosal invasion (P < 0.0001, P < 0.0001), and VEGF-C/VEGF-2-positive status (P = 0.03, P = 0.01) were significant factors in DF5YR and DF10YR. CONCLUSIONS: We conclude that VEGF-A/VEGF-1 and VEGF-C/VEGF-2 expression was predictive of these histopathologic features of endometrial carcinoma and clinical outcome.

Adult↗

PubMed2001

Risk factors for sudden unexpected death among workers: a nested case-control study in central Japan.

UNLABELLED: BACKGROUND; Few studies have focused on sudden death among apparently healthy workers, and the risk factors have not been fully discussed. METHODS: A nested case-control study was conducted among 164,017 male employees receiving annual medical checkups in Japan. Most recent medical checkup data of 242 sudden death victims (mean age, 48.0 years) were compared with corresponding data of 505 age-, workplace-, and job-type-matched male controls. Odds ratios (ORs) and their 95% confidence intervals (CIs) for each variable were calculated by logistic regression. RESULTS: OR (95% CI) significantly increased with advancing blood pressure, reaching 6.6 (3.4-13.1) for systolic blood pressure > or =160 mm Hg relative to that <120 mm Hg. Hypo-HDL-cholesterolemia, hyperuricemia, increased aminotransferases, and abnormal urinary findings were associated with the risk in a dose-dependent manner. The presence of arrhythmias and ST-T abnormalities as well as abnormal Q waves on electrocardiograms yielded a 3.5 to 4.8 times greater risk of sudden death. As for lifestyles, heavy smoking was a positive, and light drinking was a negative risk factor. Multivariate analysis revealed that hypertension, proteinuria, glucosuria, arrhythmias, ST-T abnormalities, and light drinking were independent predictors for sudden death. CONCLUSION: These findings suggest that periodic medical checkups can help to predict and prevent employee sudden death.

Blood Pressure↗

PubMed2001

Haplotype-specific sequence encoding the protein kinase, interferon-inducible double-stranded RNA-dependent activator in the human leukocyte antigen class II region.

The protein kinase, interferon-inducible double-stranded (ds)RNA-dependent activator (PRKRA) is a dsRNA-binding protein which activates a protein kinase participating in the antiviral activity of interferon. Our previous studies indicated that the nucleotide sequence encoding PRKRA, which appeared to be an intronless gene, was present in PAC HS265J14 containing the human leukocyte antigen (HLA) DR subregion. In this study, we further investigated and characterized the PRKRA gene on the human genome by means of Southern blotting and polymerase chain reaction with homozygous typing cell lines for HLA genes. Results indicated that the presence of PRKRA in the DR subregion was dependent on the DR53 group. Consistently, fluorescence in situ hybridization profiles with PRKRA as a probe showed that the hybridization signal on Chromosome (Chr) 6p21.3 was seen only in the samples carrying the DR haplotypes that belonged to the DR53 group. Interestingly, another hybridization signal, which was mapped on Chr 2q31.2-q32.1, was always detected in the samples examined, i.e., even in the samples negative for the DR53 group. The outcome of a sequence-database homology search further indicated that the PRKRA gene with introns appeared to be present in a recently opened draft-sequence, RP11-65L3 (GenBank accession number AC009948), which is located between D2S335 and D2S2257. Together, the data presented here indicate that the PRKRA gene in the DR subregion is a processed pseudogene (PRKRApsi), which could have been generated only on the DR53 common ancestor's genome, and that the master copy of PRKRApsi is most probably present on Chr 2q31.2-q32.1.

Alleles↗

PubMed2001

The genomic structure and expression of MJD, the Machado-Joseph disease gene.

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder that is clinically characterized by cerebellar ataxia and various associated symptoms. The disease is caused by an unstable expansion of the CAG repeat in the MJD gene. This gene is mapped to chromosome 14q32.1. To determine its genomic structure, we constructed a contig composed of six cosmid clones and eight bacterial artificial chromosome (BAC) clones. It spans approximately 300kb and includes MJD. We also determined the complete sequence (175,330bp) of B445M7, a human BAC clone that contains MJD. The MJD gene was found to span 48,240bp and to contain 11 exons. Northern blot analysis showed that MJD mRNA is ubiquitously expressed in human tissues, and in at least four different sizes; namely, 1.4, 1.8, 4.5, and 7.5kb. These different mRNA species probably result from differential splicing and polyadenylation, as shown by sequences of the 21 independent cDNA clones isolated after the screening of four human cDNA libraries prepared from whole brain, caudate, retina, and testis. The sequences of these latter clones relative to the MJD gene in B445M7 indicate that there are three alternative splicing sites and eight polyadenylation signals in MJD that are used to generate the differently sized transcripts.

Alternative Splicing↗