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Biomedical subjects

M Ono

Publications and source records attributed to M Ono.

At least 307 records · Page 17Linked to original sources
PubMed1997

Peripheral framework of carrot cell nucleus contains a novel protein predicted to exhibit a long alpha-helical domain.

A monoclonal antibody, CML-1, raised against carrot (Daucus carota L.) nuclear-matrix proteins selectively labeled the nuclear periphery of carrot protoplasts when visualized by confocal and electron microscopy. To identify the constituent proteins of higher plant cells structurally homologous to the vertebrate nuclear lamina, we cloned overlapping cDNAs partially encoding a CML-1-recognized protein and determined the entire sequence including the open reading frame. When the deduced amino acid sequence was compared with other known protein sequences contained in major databases, no protein was found to show high sequence identity across the whole region of the protein, while the partial sequence showed strong similarities with myosin, tropomyosin, and some intermediate filament proteins. The protein, designated NMCP1, had an estimated molecular mass of 133.6 kDa and showed three characteristic domains. The central domain contains long alpha-helices exhibiting heptad repeats of apolar residues, demonstrating structural similarity to that of filament-forming proteins. The terminal domains are predominantly nonhelical and contain potential sequence motifs for nuclear localization signals. NMCP1 has many recognition motifs for different types of protein kinases, including cdc2 kinase and PKC. These results suggest that NMCP1 protein forms coiled-coil filaments and is a constituent of the peripheral architecture of the higher plant cell nucleus.

Amino Acid Sequence↗
PubMed1997

Chromatin structure of the rat somatotropin gene locus and physical linkage of the rat somatotropin gene and skeletal-muscle sodium-channel gene.

Cosmid clones from -32 kb to +74 kb region of the rat somatotropin gene locus were isolated for examination of the chromatin structure in the region from -39 kb to +47 kb by DNase I-sensitivity analysis using rat pituitary-derived GC (somatotropin+, prolactin-), and 235 (somatotropin-, prolactin+) cells, and liver-derived BRL (somatotropin-, prolactin-) cells. DNase I-hypersensitive sites (DHS) specific for somatotropin-producing cells were previously shown to be located exclusively in the -2 kb to +9 kb region [Aizawa, A., Yoneyama, T., Kazahari, K. & Ono, M. (1995) Nucleic Acids Res. 23, 2236-2244]. No other DHS having this specificity was found in the region examined in this study. Except for these and two other DHS located in a cluster in this region, no DHS could be found from -23 kb to +22 kb. DHS having no or less cell-type specificity were scattered about in the -39 kb to -23 kb and +22 kb to +47 kb regions. The polyadenylation site of the human skeletal-muscle Na-channel alpha-subunit gene has been shown present 22 kb upstream from the somatotropin gene [Bennani-Baiti, I. M., Jones, B. K., Liebhaber, S. A. & Cooke, N. E. (1995) Genomics 29, 647-652]. Polyadenylation site of the rat skeletal-muscle Na-channel gene was shown in this study to be at -15.7 kb. The skeletal-muscle Na-channel gene was specifically expressed in skeletal-muscle cells but not in somatotropin-producing cells, and thus the boundary region that ensures the cell-type-specific expression of each gene would appear to be situated between two genes. The region prerequisite for cell-type-specific expression of the rat somatotropin gene was estimated based on the present findings.

Animals↗
PubMed1997

Purification and characterization of a carboxylesterase associated with organophosphate resistance in the greenbug, Schizaphis graminum (Homoptera: Aphididae).

The Type II esterase associated with organophosphate resistance in the greenbug, Schizaphis graminum, was purified by column chromatography and preparative electrophoresis resulting in over 100-fold purification and approximately 11% recovery. The native enzyme appears to exist as a heterodimer with the subunits equal to 52 and 56 kDa. The mass of the native enzyme was estimated at 102 kDa by gel filtration chromatography and the isoelectric focusing point was 4.8. The enzyme was inhibited by both paraoxon and mercuric chloride, suggesting that it is a serine hydrolase, although it was not inhibited by carbamate insecticides or eserine. The enzyme was active toward both beta- and alpha-naphthol esters, although the length of the side chain (C-2 or C-4) also affected activity. The enzyme displayed no activity toward acetylthiocholine. N-Terminal amino acid sequence analysis of the enzyme subunits indicates that residues Val-4 and Gly-10 of the larger fragment were highly conserved among 11 other carboxylesterase sequences. Sequence data from the smaller fragment did not reveal any similarity with other esterase sequences.

Amino Acid Sequence↗
PubMed1997

Arteriovenous malformations of the basal ganglia region: rationale for surgical management.

Surgical indications for arteriovenous malformations (AVMs) arising at the region of the basal ganglia are questionable and the majority of cases are considered inoperable. Albeit not free from risks of morbidity and mortality, the treatment of choice is usually radiosurgery for small lesions, and embolization plus radiosurgery for larger lesions. Nevertheless, some lesions may be amenable for surgical resection due to their favorable location. Eighteen cases of such AVMs were selected for a direct approach in our series. Seventeen cases were classified as Spetzler and Martin [22] grade III, and one case was a grade V. Ten patients were males and eight females. The mean age was 28.3 years (ranged from 2 to 43 years). Sixteen patients had had previous hemorrhagic events prior to hospital admission. Eleven patients had pre-operative well established neurological deficits, and seven patients although symptomatic had a normal neurological exam at admission. Fifteen patients had their AVMs completely resected. Among the eleven patients with previous neurological deficits nine had no change in their pre-operative condition and two experienced postoperative neurological worsening. In the long-term follow-up six patients had a complete recovery and five recovered only partially. Among the seven patients whose neurological examination was normal pre-operatively five remained unchanged, one had a transient motor deficit, and one died due to a thalamic venous infarction and massive bleeding into the thalamus. The anatomical knowledge and the precise localization of the arteriovenous malformation through the aid of neuroimage studies has provided the means to classify these AVMs and plan operative strategies for some small selected cases with relatively low morbidity.

Adolescent↗
PubMed1997

Acute acalculous cholecystitis with a decrease in CD4/CD8 ratio.

Acute acalculous cholecystitis (AAC) usually occurs in the elderly and in those with severe pre-existing pathological conditions. However, there have recently been reports of AAC in relatively young immunosuppressed patients, such as those with acquired immunodeficiency syndrome (AIDS). We report here a 27-year-old woman with AAC who received an emergent cholecystectomy. Although anti-human immunodeficiency virus antibody (anti-HIV) was not detected, a decrease in the CD4/CD8 ratio in sera was found. This rare case of AAC in a patient with decreased CD4/CD8 ratio who showed no other related diseases suggests that surgeons should keep in mind the possible presence of immunosuppression in this condition.

Acute Disease↗
PubMed1997

Expression of the feline herpesvirus type 1 ICP4 gene is controlled by two alternative promoters.

Feline herpesvirus type 1 (FHV-1) produces a single 5.4 kb immediate-early (IE) transcript encoding FHV-1 ICP4 which acts as a trans-acting factor [Kawaguchi et al. (1994) Virology 204: 430-435]. Our earlier study has shown that the FHV-1 IE transcript is spliced in the leader region and the FHV-1 IE gene product (ICP4) down-regulates its own promoter through the region which includes its transcription initiation site [Kawaguchi et al. (1996) J Vet Med Sci 58: 715-721]. Here we investigated FHV-1 ICP4 gene expression throughout FHV-1 productive infection and demonstrated that (i) a novel promoter is located downstream of the IE promoter and an early transcript is transcribed from this promoter region, (ii) a negative regulatory element, which is composed of a 20 bp direct repeat unit repeated 20 times, is located between the two promoters and the repeat unit shows high homology to a motif called direct repeat 2 in "a" sequence of herpes simplex virus type 1, (iii) the IE promoter and synthesis of the IE mRNA appear to be turned off after IE phase and the second promoter becomes active during early and late stages, and (iv) a gene product expressed only by the second promoter also possesses regulatory function. These findings indicate that expression of the FHV-1 ICP4 gene is alternatively regulated by the two promoters.

Animals↗
PubMed1997

Use of high-speed, high-resolution thermography to evaluate the tear film layer.

PURPOSE: To evaluate the tear film layer in patients with dry eye and in normal subjects by measuring the corneal temperature with infrared radiation thermography. METHODS: One eye of each of 13 patients with dry eye and one eye of each of seven normal subjects were evaluated randomly. The corneal temperature was measured continuously with a recently improved infrared radiation thermography technique. We calculated the k value, which reflected the steepness of the corneal temperature change. The bigger the k value was, the more rapid was the decrease in corneal temperature, and this was directly related to increased evaporation. RESULTS: With normal blinking, the mean k value for patients with dry eye (5.6 +/- 2.9 per second) was significantly less than that in the control subjects (9.3 +/- 5.0 per second; P < .05). Keeping the eyes open after closing the eyes significantly decreased the k values compared with normal blinking in both groups (P < .05). CONCLUSIONS: Our findings demonstrate the usefulness of this method of measuring corneal temperature to evaluate the tear film layer. High-speed, high-resolution thermography detected subtle changes in corneal temperature with enhanced sensitivity and spatial and temporal resolution. We found that the mean k value, and therefore the rate of decline in corneal temperature in patients with dry eye, was significantly less than that in normal subjects. The k value may therefore reflect tear film layer stability. The measurement of the changes in the corneal temperature can thus give us valuable information on the tear film layer.

Adult↗
PubMed1997

Chronic expanding hematoma in the chest.

We herein report the successful surgical treatment of 2 cases of chronic expanding hematoma in the chest. The first patient, who had undergone thoracoplasty 42 years earlier due to tuberculosis, became aware of a slowly growing mass protruding in the lateral thoracic wall. The second patient, who had tuberculous pleurisy 36 years earlier, was referred to our department because of a slowly expanding intrathoracic mass revealed by a roentgenogram. The tumors, which were encapsulated chronic hematomas, were both surgically resected. These cases are rare because of the development of a very large mass after undergoing treatment for tuberculosis more than 30 years previously.

Aged↗
PubMed1997

Effects of clomiphene citrate on the endometrial thickness and echogenic pattern of the endometrium.

OBJECTIVE: To study the effects of clomiphene citrate (CC) on the endometrium by ultrasound and to reveal the echogenic difference between the control cycle and the CC cycle. DESIGN: Retrospective study of patients before and during a CC treatment. SETTING: Department of Obstetrics and Gynecology, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan. PATIENT(S): Seventy-nine infertile women who had a spontaneous ovulation and a normal luteal function. INTERVENTION(S): Patients received 50 mg/d CC between days 5 and 9 of the menstrual cycle. MAIN OUTCOME MEASURE(S): Endometrial thickness, echogenic pattern of the endometrium, serum E2 content, and E2 and P receptor contents in the endometrium. RESULT(S): Endometrial thickness was significantly thinner during the CC cycle (7.6 +/- 1.4 mm, mean +/- SD, n = 79) than during the control cycle (8.5 +/- 1.7 mm, n = 79) on late proliferative days, but there was no significant difference on midsecretory days (10.8 +/- 2.2 mm during the CC cycle, n = 79; 11.2 +/- 2.2 mm during the control cycle, n = 79). The echogenic patterns, however, were different between the two cycles on midsecretory days. Moreover, the incidence in which patients showed a grade 3 endometrium on midsecretory days was significantly higher during the conceived CC cycle compared with the not-conceived CC cycle. Serum E2 levels were significantly higher, but E2 receptor contents in the endometrium were significantly lower during the CC cycle (67 +/- 46 fmol/mg, n = 13) compared with the control cycle (123 +/- 89 fmol/mg, n = 15) on late proliferative days. CONCLUSION(S): Clomiphene citrate affected the echogenic pattern of the endometrium, and most of the endometrium showed a grade 3 pattern on midsecretory days during the conceived CC cycle. Under the CC treatment, the comfortable endometrium for embryos might be different from the control cycle.

Adult↗
PubMed1997

Identification and DNA sequence analysis of the Marek's disease virus serotype 2 genes homologous to the thymidine kinase and UL24 genes of herpes simplex virus type 1.

The thymidine kinase (TK) gene has been used as a safe and convenient locus for expression of heterologous proteins in some alphaherpesviruses including herpesvirus of turkeys (HVT) antigenically related to Marek's disease virus (MDV) serotypes 1 (MDV1) and 2 (MDV2). In MDV2 strain HPRS 24 genome, genes equivalent to the TK and UL24 homologues of herpes simplex virus type 1 were identified and sequenced. The MDV2 UL24 gene overlaps the 5' end of the TK gene in a head-to-head orientation. The predicted region encoding for the MDV2 TK gene is 1,056 nucleotides, corresponding to a polypeptide of 352 amino acids in length. Putative nucleotide- and thymidine-binding sites were identified within the predicted amino acid sequence. The predicted region encoding for the UL24 gene is 948 nucleotides, corresponding to a polypeptide of 316 amino acids in length. By northern blot analyses using MDV2 TK- and UL24-specific DNA probes, four transcripts of approximately 7.8, 5.0, 3.5, and 1.1 kb for the TK gene, and a transcript of 3.8 kb for the UL24 gene were detected in MDV2-infected cells. Alignment of the amino acid sequence of MDV2 TK homologue with those published for TK homologues of other MDV serotypes showed 73.9% (MDV1 vs. MDV2), 58.2% (MDV1 vs. HVT), and 56.8% (MDV2 vs. HVT) identities. Comparison to other alphaherpesvirus TK homologues revealed amino acid sequence homologies varying from 34.5% to 27.8%. The putative MDV2 UL24 homologous protein had identity with the well conserved five motifs among alphaherpesviruses.

Amino Acid Sequence↗
PubMed1997

FP-21399 blocks HIV envelope protein-mediated membrane fusion and concentrates in lymph nodes.

The identification of fusin and other chemokine receptors as coreceptors for HIV-1 has renewed the interest in agents that may prevent viral entry. Polyanionic compounds such as dextran sulfate, curdian sulfate, and suramin act on the V3 loop of the viral envelope and may prevent its interaction with fusin. These agents show activity against a wide range of HIV-1 strains, but have undesirable circulating half-life, bioavailability, and toxicity. We have developed a small molecule inhibitor of HIV-1 that has several advantages over these other agents. FP-21399 is a novel compound of the bis(disulfonaphthalene) dimethoxybenzene class that blocks entry of HIV into CD4+ cells and blocks fusion of infected and noninfected CD4+ cells. This compound only weakly inhibits binding of CD4 and gp120, at concentrations much greater than are required to block viral entry. Furthermore, FP-21399 can block the interaction between gp120 and antibodies directed against the V3 loop, but does not block binding of antibodies directed against the V4 loop. Animal studies demonstrate that FP-21399 is concentrated in lymph nodes, making it a promising compound for anti-HIV therapy. In SCID mice reconstituted with human immune cells, maintenance of HIV-1 infection was blocked by a 5-day treatment with low doses of FP-21399, suggesting that lymph node accumulation may contribute to antiviral activity. Finally, attempts to generate drug-resistant virus in cell culture resulted in only weakly resistant variants with IC90 values that are much lower than concentrations of FP-21399 found in lymph nodes.

Animals↗
PubMed1997

A novel brain-specific p53-target gene, BAI1, containing thrombospondin type 1 repeats inhibits experimental angiogenesis.

The genetic alteration of p53 is associated with neovascularization during progression of glioma to its more malignant form, glioblastoma. Hence, one or more of the genes transactivated by p53 is likely to function as an angiogenesis inhibitors. We isolated a novel p53-inducible gene that encodes a 1584-amino-acid product containing five thrombospondin type 1 (TSP-type 1) repeats and is specifically expressed in the brain. A recombinant protein corresponding to the TSP-type 1 repeats of this gene product inhibited in vivo neovascularization induced by bFGF in the rat cornea. The expression of this gene, designated BAI1 (brain-specific angiogenesis inhibitor 1) was absent or significantly reduced in eight of nine glioblastoma cell lines, suggesting BAI1 plays a significant role in angiogenesis inhibition, as a mediator of p53.

Amino Acid Sequence↗
PubMed1997

Growth hormone-releasing hormone (GHRH)-GH-somatic growth and luteinizing hormone (LH)RH-LH-ovarian axes in adult female transgenic mice expressing human GH gene.

We have examined alterations in the hypothalamo-pituitary GH-somatic growth axis and the hypothalamo-pituitary LH-ovarian axis in a line of transgenic ICR mice expressing human GH (hGH) under the influence of the whey acid protein promoter. Transgenic female mice weighed twice as much as control females and were infertile. The size of the anterior pituitary (AP) was 1/3 that of the controls. In transgenic mice, acinar cells in the mammary and mandibular glands displayed hGH-immunoreactivity, and plasma hGH was detected by radioimmunoassay. In the medial basal hypothalamus (MBH) of transgenic females, the immunoreactive-GHRH level was decreased (P<0.01). There was a corresponding reduction in the number of GHRH-immunoreactive neurons in the arcuate nucleus (ARC) and in the immunostaining of GHRH nerve terminals in the median eminence. The level of somatostatin (SRIH) in the MBH was increased (P<0.05), and SRIH-immunoreactive neurons in the periventricular nucleus (PeV) were increased in size and number in transgenic mice. The MBH level of LHRH in transgenic animals was greater (P<0.01) than in controls, although there was no apparent difference in the number of LHRH-immunoreactive neurons or in LHRH level in the preoptic area. There are fewer SRIH- and LHRH-immunoreactive neurons in the ARC in transgenic mice. Cells in the AP for GH, PRL, and LH were fewer in transgenic mice. The ovary suffered disturbance of follicular development and of corpora lutea formation. These results demonstrate that chronic overproduction of hGH may profoundly affect the organization of the GHRH/SRIH-GH-somatic growth axis and the LHRH-LH-ovarian axis due to reduction of GHRH-, SRIH- and LHRH-neurons in the ARC and increase of SRIH-neurons in the PeV.

Animals↗
PubMed1997

All-trans-retinoic acid-dependent inhibition of E-cadherin-based cell adhesion with concomitant dephosphorylation of beta-catenin in metastatic human renal carcinoma cells.

We previously described an in vitro invasion assay model, using a monolayer of vascular endothelial cells grown on collagen gel, that mimics the metastatic abilities of the highly metastatic human renal carcinoma cell lines, MM-1,3 and 8 and their poorly metastatic counterparts, SN12C and Cl-8. MM-1, 3 and 8 cells were observed to penetrate the monolayer of vascular endothelial cells and grew in a spreading or scattering manner with loose cell-cell contact on collagen gel or on vascular endothelial cells. SN12C and Cl-8 cells failed to penetrate and grew in a clustering manner with tight cell-cell contact. Treatment with all-trans-retinoic acid (ATRA) at non-toxic concentrations induced clustering or growth of MM-1, 3 and 8 cells on collagen gel or on vascular endothelial cells with tight cell-cell contact, and inhibited penetration. The clustering induced by ATRA was virtually blocked in the presence of anti-E cadherin antibody. E-Cadherin and beta-catenin were each localized mainly at the cell-cell adherent junctions of colonizing cell populations that had been treated with ATRA. While the cellular levels of E-cadherin and beta-catenin did not change significantly following ATRA treatment, the tyrosine residue of beta-catenin was rapidly dephosphorylated. The concomitant administration of Na vanadate, an inhibitor of tyrosine dephosphorylase, inhibited both the ATRA-induced clustering and the dephosphorylation of beta-catenin tyrosine. ATRA-induced clustering of MM-3 cells may be linked to the state of tyrosine phosphorylation of beta-catenin.

Adult↗
PubMed1997

Involvement of interleukin-8, vascular endothelial growth factor, and basic fibroblast growth factor in tumor necrosis factor alpha-dependent angiogenesis.

Tumor necrosis factor alpha (TNF-alpha) is a macrophage/monocyte-derived polypeptide which modulates the expression of various genes in vascular endothelial cells and induces angiogenesis. However, the underlying mechanism by which TNF-alpha mediates angiogenesis is not completely understood. In this study, we assessed whether TNF-alpha-induced angiogenesis is mediated through TNF-alpha itself or indirectly through other TNF-alpha-induced angiogenesis-promoting factors. Cellular mRNA levels of interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and their receptors were increased after the treatment of human microvascular endothelial cells with TNF-alpha (100 U/ml). TNF-alpha-dependent tubular morphogenesis in vascular endothelial cells was inhibited by the administration of anti-IL-8, anti-VEGF, and anti-bFGF antibodies, and coadministration of all three antibodies almost completely abrogated tubular formation. Moreover, treatment with Sp1, NF-kappaB, and c-Jun antisense oligonucleotides inhibited TNF-alpha-dependent tubular morphogenesis by microvascular endothelial cells. Administration of a NF-kappaB antisense oligonucleotide almost completely inhibited TNF-alpha-dependent IL-8 production and partially abrogated TNF-alpha-dependent VEGF production, and an Sp1 antisense sequence partially inhibited TNF-alpha-dependent production of VEGF. A c-Jun antisense oligonucleotide significantly inhibited TNF-alpha-dependent bFGF production but did not affect the production of IL-8 and VEGF. Administration of an anti-IL-8 or anti-VEGF antibody also blocked TNF-alpha-induced neovascularization in the rabbit cornea in vivo. Thus, angiogenesis by TNF-alpha appears to be modulated through various angiogenic factors, both in vitro and in vivo, and this pathway is controlled through paracrine and/or autocrine mechanisms.

Animals↗