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Biomedical subjects

Y Kurihara

Publications and source records attributed to Y Kurihara.

At least 127 records · Page 7Linked to original sources
PubMed1996

[Motor evoked potentials of transcranial magnetic stimulation for Parkinson's disease].

We studied motor evoked potential (MEP) elicited by transcranial magnetic stimulation (TMS) in 37 patients with Parkinson's disease (PD). TMS was used at high energy capacity (800 Volts) in all patients and normal subjects under resting position. MEPs were recorded from the abductor pollicis brevis and the abductor hallucis. Magnetic stimulator equipped with an 8-shaped coil and a flat type coil was used for TMS. The data were statistically evaluated using a paired Student t test. The latency of MEPs were slightly shorter in PD patients than that in normal subjects. There were significant differences between HV. (Healthy volunteers) and group B (Hoehn & Yahr's stage III) (p = 0.012), HV, and group C (Hoehn & Yahr's stage IV.V) (p = 0.002), group A (Hoehn & Yahr's stage I.II) and C (p = 0.005) respectively. The duration of MEPs became longer depending on the severity of PD evaluated by Hoehn & Yahr's disability rating. Significant correlations were found between HV, and group C (p = 0.001), group A and C (p = 0.015). The amplitude of MEPs also increased with the severity on the rating. There were significant differences between HV, and group C (p = 0.0002), group A and B (p = 0.0004), group B and C (p = 0.0009) respectively. These changes of MEP findings indicated the dysfunction of pyramidal motor pathways in PD. Thus, the disability in patients with PD can be well evaluated by MEP measurement.

Adult↗
PubMed1995

Cloning and sequencing of a cDNA encoding a taste-modifying protein, miraculin.

A cDNA clone encoding a taste-modifying protein, miraculin (MIR), was isolated and sequenced. The encoded precursor to MIR was composed of 220 amino acid (aa) residues, including a possible signal sequence of 29 aa. Northern blot analysis showed that the mRNA encoding MIR was already expressed in fruits of Richadella dulcifica at 3 weeks after pollination and was present specifically in the pulp.

Amino Acid Sequence↗
PubMed1995

Longitudinal characteristic curve of liver disease.

A longitudinal characteristic curve of chronic liver disease (LCC-LD) is derived for the first time by a new method of time series data analysis, where a hospital information system is utilized as a clinical research application of the database. It describes a typical pattern of development of disease from the beginning of chronic hepatitis to the final stage of cirrhosis. The LCC-LD is obtained by effectively using patient data with various stages of developments of liver disease and the present method is applicable to derive the LCC of other diseases. The obtained LCC-LD may be useful for a clinical decision making support such as the prospective assessment (for example, the onset time of cirrhosis) of liver disease in individual patients, an evaluation of drug effect, etc.

Algorithms↗
PubMed1995

Activity and stability of a new sweet protein with taste-modifying action, curculin.

Curculin elicited a sweet taste. After the sweetness of curculin diminished, application of deionized water or an acid to the tongue induced a sweet taste. The maximum sweetness of curculin itself was equivalent to the sweetness of 0.35 M sucrose. The maximum sweetness induced by 0.02 M citric acid or deionized water after curculin dissolved in a buffer of pH 6.0 was held in mouth for 3 min was also equivalent to that of 0.35 M sucrose. The sweetness induced by deionized water was completely suppressed by the presence of 1 mM CaCl2 or MgCl2, while that induced by an acid was not suppressed by the presence of divalent cations. Based on these results, the mechanism of the taste-modifying activity was discussed. Stability of curculin was examined under various conditions. The taste-modifying activity of curculin was unchanged when curculin was incubated at 50 degrees C for 1 h between pH 3 and 11.

Citrates↗
PubMed1995

Varied radiologic appearances of pulmonary aspergillosis.

Pulmonary aspergillosis represents a common, potentially lethal opportunistic infection that has four unique forms: allergic bronchopulmonary aspergillosis (ABPA), aspergilloma, and invasive and semi-invasive aspergillosis. In individuals who are at risk, pulmonary aspergillosis is characterized by a spectrum of clinical and radiographic findings that are intrinsically related to the status of the immune system or the presence of structural lung disease. ABPA, occurring almost exclusively in asthma patients, is characterized radiographically by fleeting pulmonary alveolar opacities caused by deposition of immune complexes and inflammatory cells within the lung parenchyma. Mucus plugging and bronchial wall thickening can be expected in time. Aspergilloma, occurring in patients with structural lung disease, typically appears radiographically as a focal intracavitary mass and is characterized initially by an increase in the wall thickness of a preexisting cavity or cyst. Invasive aspergillosis, which occurs primarily in profoundly immunocompromised patients, may exhibit nonspecific patchy nodular opacities or lobar-type air-space disease in cases with vascular invasion. Computed tomography may reveal a halo or ground-glass attenuation and is more accurate in the detection of early disease. Cavitation often develops with time and typically results in the air crescent sign. Semi-invasive aspergillosis is radiographically similar to the invasive form but differs in clinical course, being associated with mild immunosuppression or chronic illness and typically progressing over the course of months rather than weeks.

Aspergillosis↗
PubMed1995

Targeting gene expression to the vascular wall in transgenic mice using the murine preproendothelin-1 promoter.

To develop a system for overexpressing genes in the vascular wall, we created transgenic mice using the reporter gene luciferase and the murine preproendothelin-1 promoter. In vitro analysis suggested that the murine 5'-flanking region contained endothelial-specific elements in a 5.9-kb fragment. Five transgenic mice colonies established from independent founders all exhibited the highest level of luciferase activity in the aorta with up to 8,540 light units per microgram of protein. Immunohistochemistry with anti-luciferase antisera revealed high levels of expression in the endothelial cells of both large and small arteries and lower levels of expression in veins and capillaries. Significant expression was also seen in arterial smooth muscle cells and in select epithelial surfaces which is consistent with the known distribution of endothelin-1 in mammals. The further demonstrate the targeting capability of this system, we overexpressed the lipid-peroxidating enzyme, human 15-lipoxygenase, in the vessel wall of transgenic mice. As with luciferase, expression of active enzyme and immunohistochemical localization in vascular cells were documented in transgenic animals. Hence, this new system can be used to direct expression of molecules to the vascular wall for the purpose of examining the biological significance of either overexpression or inhibition of select proteins.

Animals↗
PubMed1995

Aortic arch malformations and ventricular septal defect in mice deficient in endothelin-1.

Endothelin-1 (ET-1) is a 21-amino acid peptide with various biological activities including vasoconstriction and cell proliferation. To clarify the physiological and pathophysiological role of ET-1, we disrupted the mouse Edn1 locus encoding ET-1 by gene targeting and demonstrated that ET-1 is essential to the normal development of pharyngeal arch-derived tissues and organs. In this study, we focused on the phenotypic manifestations of Edn1-/- homozygous mice in the cardiovascular system. Edn1-/- homozygotes display cardiovascular malformations including interrupted aortic arch (2.3%), tubular hypoplasia of the aortic arch (4.6%), aberrant right subclavian artery (12.9%), and ventricular septal defect with abnormalities of the outflow tract (48.4%). The frequency and extent of these abnormalities are increased by treatment with neutralizing monoclonal antibodies or a selective ETA receptor antagonist BQ123. At an earlier embryonic stage, formation of pharyngeal arch arteries and endocardial cushion is disturbed in Edn1-/- homozygotes. In situ hybridization confirmed ET-1 expression in the endothelium of the arch arteries and cardiac outflow tract and the endocardial cushion as well as in the epithelium of the pharyngeal arches. Thus, ET-1 is involved in the normal development of the heart and great vessels, and circulating ET-1 and/or other ET isoforms may cause a functional redundancy, at least partly, through the ETA receptor.

Animals↗
PubMed1995

Distributing an electronic thoracic imaging teaching file using the Internet, Mosaic, and personal computers.

A high quality film-based teaching file requires effort and expense to create and maintain. The effort is worthwhile because film collections are important vehicles for increasing a radiologist's personal data base of clinical experience. Expert clinical reasoning is to a large extent the process of comparing a current case to a data base of individual cases available in memory. A teaching file would be most helpful if it were available at the view box where it could be used to extend a radiologist's clinical experience. Unfortunately, a film-based file is confined to one area, usually remote from the view box. In addition, searching though a film file is difficult, the films wear out over time, and films are easily lost or stolen. Our goal is the creation of a thoracic imaging teaching file that solves these problems by providing a digital collection of images, videos, and text that can be used in the work place by many users simultaneously. The first part of this teaching file is now continuously available locally within our department and globally to users of the Internet.

Computer Communication Networks↗
PubMed1995

Effects of salivary immune response to Streptococcus mutans on caries occurrence and caries development in mice with autoimmune disease.

MRL/l strain mice, which possess a lymphoproliferative gene inducing swelling of systemic lymph nodes, develop a SLE (systemic lupus erythematosus)-like syndrome at around 8 w of age. MRL/n mice, which carry 99.6% of the genes of MRL/l mice, lack the gene for lymphoproliferation and exhibit only a slight degree of lymph node swelling late in life. This study investigated whether the salivary immune response caused by Streptococcus mutans(S. mutans) infection prevented dental caries in MRL/l and MRL/n mice after 8 w of age. A total of 10 MRL/l mice and 10 MRL/n mice were fed a commercial pellet diet without sucrose until 74 d of age, and then fed Diet 2000 containing 56% sucrose ad libitum from 75 to 130 d of age. On d 75, both strains of mice were inoculated with S. mutans JC-2 for 7 d. At 130 d of age, saliva samples were collected and caries scores were assessed. The results obtained suggested that the salivary immune response was one of the most important factors regulating caries occurrence.

Animals↗
PubMed1995

Impaired development of the thyroid and thymus in endothelin-1 knockout mice.

We have previously demonstrated that endothelin-1 (ET-1) is essential to the development of neural crest-derived craniofacial and cardiovascular structures. In this study we evaluated the intrauterine growth and development of the thyroid and thymus glands in Edn1-/- homozygous mice. Edn1-/- homozygous mice were smaller than their heterozygous or wild-type littermates (about 90% of normal body weight). The thyroid and thymus of Edn1-/- homozygous mice were smaller than those of normal mice and were not fused in the midline, resulting in two separate lobules. The thymus of Edn1-/- homozygous mice is not descended into the normal position. These results suggest that ET-1 is important for normal development of the glands in the neck region, as well as for systemic growth. The combination of abnormalities in Edn1-/- homozygous mice suggests that these mice might serve as an animal model for the human diseases DiGeorge syndrome and velocardiofacial syndrome.

Animals↗
PubMed1995

Gene expression of endothelin isoforms and receptors in endothelin-1 knockout mice.

Gene expression of endothelin (ET) isoforms and receptors was examined in ET-1 knockout mice and compared with that of wild-type mice. ET-1 mRNA and peptide levels were in parallel with the number of Edn1 authentic alleles. ET-2 mRNA levels in intestine and ET-3 mRNA and/or peptide levels in lung, brain, and intestine were not different among Edn1+/+ wild-type, Edn1+/- heterozygous, and Edn1-/- homozygous mice. ET(A) and ETB receptor mRNA levels in several organs also were not different among Edn1+/+ wild-type, Edn1+/- heterozygous, and Edn1-/- homozygous mice. These results suggest that gene expression of ET-2, ET-3, and ET(A/B) receptors is not affected by levels of ET-1 production and is regulated independently. Neither compensation by redundant expression of other ET isoforms nor upregulation of ET receptors could explain the elevated blood pressure in Edn1+/- heterozygous mice.

Animals↗
PubMed1995

Characterization of an HDV ribozyme which consists of three RNA oligomer strands.

Properties of a mutant hepatitis delta virus (HDV) ribozyme which consists of three RNA oligomer strands (Fig. 1c) are described. Effects of the MgCl2 concentration, pH and temperature on the cleavage reaction were examined. The dependence on these conditions did not resemble those of the published data for other HDV ribozymes (the parent) which consist of single-strand RNA of about 90 nt. The highest cleavage for the mutant was observed at 35-40 degrees C, while the parent ribozymes show higher activity at around 60 degrees C than at 40 degrees C. Thus we suppose that the most of the parent ribozymes are in inactive conformation at 40 degrees C and high temperature is needed to change the equilibrium between the inactive and active conformations. Since the Tm of the mutant was around 50 degrees C, these results suggest that the most of the mutant ribozyme complex molecules are in active conformation at 40 degrees C.

Base Sequence↗
PubMed1995

Structure of translation initiation region of c-myc mRNA and thermostability of the c-myc mRNA/antisense ODN complex.

We enzymatically synthesized c-myc mRNA fragment containing the translation initiation (TI) region (36mer) and examined the structure by CD, 1H-NMR and RNaseV1 digestion. These study demonstrated that the c-myc mRNA fragment forms a hairpin structure at 37 degrees C. Six 15-mer antisense oligodeoxynucleotides(ODNs), which hybridize to the c-myc mRNA fragment were designed, and synhesized. Thermostabilities of the antisense ODNs-mRNA fragment complexes were examined. Antisense A (complementary to the c-myc mRNA from -9 to +6)-c-myc mRNA fragment complex had the highest melting temperature(Tm), and Antisense D (complementary to the c-myc mRNA from +1 to +15)-c-myc mRNA fragment complex had the most different Tm from a predicted Tm. Furthermore, Antisense D exhibited high inhibitory effect on HL60 cell proliferation, whereas Antisense A did not. The results suggest that the difference in the antisense effect is not simply due to the complex thermostability.

Cell Line↗