Biomedical subjects

K Araki

Publications and source records attributed to K Araki.

At least 55 records · Page 3Linked to original sources

PubMed2001

Truncated hantavirus nucleocapsid proteins for serotyping Hantaan, Seoul, and Dobrava hantavirus infections.

Truncated recombinant nucleocapsid proteins (rNPs) of Hantaan virus (HTNV), Seoul virus (SEOV), and Dobrava virus (DOBV) were expressed by a baculovirus system. The truncated rNPs, which lacked 49 (rNP50) or 154 (rNP155) N-terminal amino acids of the NPs of HTNV, SEOV, and DOBV, were able to differentiate HTNV-, SEOV-, and DOBV-specific immune sera. Recombinant NP50s retained higher reactivities than rNP155s and were proven useful for enzyme-linked immunosorbent assay (ELISA). The ELISAs based on the rNP50s of HTNV, SEOV, and DOBV successfully differentiated three groups of patient sera, previously defined by neutralization tests: 17 with HTNV infection, 12 with SEOV infection, and 20 with DOBV infection. The entire rNP of Puumala virus (PUUV) distinguished PUUV infection from the other types of hantavirus infection. Serotyping with these rNP50s can be recommended as a rapid and efficient system for hantavirus diagnosis.

Animals↗

PubMed2001

Immunohistochemical analysis of small cell carcinoma of the head and neck: a report of four patients and a review of sixteen patients in the literature with ectopic hormone production.

Small cell carcinoma (SCC) occurs mostly in the lung, and in some patients is accompanied by production of ectopic hormones. Small cell carcinoma of the head and neck is very rare. We report 4 patients with SCC of the head and neck (larynx, tonsil, maxillary sinus, and parotid gland). The patient with SCC of the maxillary sinus demonstrated a high level of plasma serotonin and overexpression of parathyroid hormone; however, he did not show any related symptoms. The patient with SCC of the tonsil showed the syndrome of inappropriate secretion of antidiuretic hormone associated with antidiuretic hormone hyperproduction at the terminal stage. In the literature, 16 patients with SCC of the head and neck with ectopic hormone production have been reported. Antidiuretic hormone and adrenocorticotropic hormone were the hormones that caused clinical symptoms (paraneoplastic syndromes). We believe that the evaluation of hormonal syndromes is valuable for diagnosis and treatment.

Aged↗

PubMed2001

Epizootiological survey of hantavirus among rodent species in Ningxia Hui Autonomous Province, China.

Hantaviral antibodies were detected in the sera from Apodemus (A.) agrarius and A. peninsulae captured in Ningxia province, China by several different serological diagnostic methods. A total of 409 sera from rodent and insectivore species were collected in 1999 and examined by indirect immunofluorescent antibody assay (IFA). Among them, 19 of 191 (9.9%) sera of A. agrarius and 1 of 13 (7.7%) sera of A. peninsulae were positive for hantaviral antibodies. The other species (Rattus norvegicus, Mus musculus, Cricetulus triton, and Sorex cylindricauda) were negative. The reaction pattern of positive serum was characterized as scattered and granular virus antigens in the cytoplasm of hantavirus infected Vero E6 cells. Some of the A. agrarius sera positive for hantavirus were further examined by Western blotting (WB), enzyme-linked immunosorbent assay (ELISA), and the focus reduction neutralization test (FRNT). By WB, positive sera showed the same specific reaction pattern of baculovirus-expressed recombinant hantaviral nucleocapsid protein, as shown in hantavirus-immune serum. By ELISA, IFA-positive sera showed significantly higher optical densities (around 1.0) than the negative A. agrarius sera. Hantaan type hantavirus was neutralized with the positive sera. These results suggest that A. agrarius have hantavirus infection and may play a role as a reservoir animal for hantavirus in Ningxia Hui Autonomous Province, China.

Animals↗

PubMed2000

Genetic diversity of hantaviruses isolated in china and characterization of novel hantaviruses isolated from Niviventer confucianus and Rattus rattus.

The antigenic and genetic properties of 46 hantaviruses from China, 13 from patients, 23 from rodents, and 10 from unknown hosts, were compared with those of other hantaviruses. The viruses were classified as either Hantaan (HTN) or Seoul (SEO) viruses. A phylogenetic analysis of the partial M (300 bp) and S (around 485 bp) genomes of HTN viruses identified nine distinct genetic subtypes, one consisting of isolates from Korea. The SEO viruses were divided into five genetic subtypes, although they had less variability than the HTN subtypes. There was a correlation between the subtype and province of origin for four subtypes of HTN viruses, confirming geographical clustering. Hantaan virus NC167 isolated from Niviventer confucianus and SEO virus Gou3 isolated from Rattus rattus were the basal clades in each virus. The phylogenetic trees constructed from the entire S and M segments suggested that NC167 was introduced to N. confucianus in a host-switching event. The reactivity of a panel of 35 monoclonal antibodies was almost exactly the same in NC167 and a representative HTN virus and in Gou3 and a representative SEO virus. However, there was a one-way cross-neutralization between them. These results confirm the varied nature of Murinae-associated hantaviruses in China.

Animals↗

PubMed2000

A reliable method for culture of dissociated mouse cerebellar cells enriched for Purkinje neurons.

The cerebellar Purkinje neuron (PN) serves as an important model in studies of neuronal development in the mammalian central nervous system. Dissociated PN preparations maintained in an in-vitro environment with simplified cellular and biochemical conditions can facilitate molecular analyses of neuronal development. Here we describe a reliable method to prepare dissociated cultures of mouse cerebellar neurons maintained with a serum-free, Dulbecco's modified Eagle's medium/F-12 nutrient-based medium, which facilitates PN survival and dendritic differentiation. The survival of mouse PNs in this culture was maximized when cerebellar cells were (1) taken from prenatal animals, (2) dissociated with papain, and (3) seeded at a density of 5 000 000 cells/ml or higher. Dissociated PNs prepared by our method from mice of embryonic day 18 (E 18) reproduced several morphological and electrophysiological changes seen in intact postnatal rodents with similar time-courses. Therefore, our culture method offers a useful model for investigating molecular mechanisms underlying postnatal neuronal development.

Action Potentials↗

PubMed2000

Observation of a spin-flip M1 transition in 7(lambda)Li.

Using a large-acceptance germanium detector array (Hyperball), we have observed a spin-flip M1 gamma transition between the ground-state spin doublet of (7)(Lambda)Li (3/2(+)-->1/2(+)). The observed energy of 691.7+/-0.6(stat)+/-1.0(syst) keV provides crucial information on the strength of the spin-spin interaction between a Lambda and a nucleon. This is the first observation of well-identified hypernuclear gamma transitions using germanium detectors.

Journal Article↗

PubMed2000

p53 polymorphism in human papillomavirus-associated esophageal cancer.

Human papillomavirus type 16/18 (HPV-16/18) is implicated in the pathogenesis of squamous cell carcinoma (SCC) of the cervix and esophagus. The arginine allele at codon 72 of p53 was found to be more susceptible to degradation by HPV E6 protein than is the proline allele in vivo, thus resulting in a high frequency of cervical SCC in individuals homozygous for arginine at the codon. There are controversial results from several clinical studies of cervical SCC. In the present study, encoding regions of p53 codon 72 and HPV-16/18 E6 were directly sequenced, using pairs of primary esophageal SCC tissue and corresponding normal mucosa, which were from 75 patients (Japanese, n = 38; Chinese, n = 37). The arginine allele alone was detected in 70.6% (12 of 17) of HPV-positive cases but only in 43.1% (25 of 58) of HPV-negative cases (P < 0.05). In contrast, such a significant correlation between p53 polymorphism and HPV infection was not evident in corresponding normal mucosae. Because our findings between tumor specimens and the normal mucosae differed, we suggest that the frequent loss of proline allele in HPV-associated carcinogenesis of the esophagus major plays some role. The particular type of p53 polymorphism may indicate a potential candidate for HPV-associated SCC.

Alleles↗

PubMed2000

Effects of pH and chloride concentration on resonance Raman spectra of human myeloperoxidase and Raman microspectroscopic analysis of enzyme state in azurophilic granules.

Resonance Raman spectra of human myeloperoxidase were examined at pH 3.3-10.5 in the absence and presence of chloride ions. Among the porphyrin vibrational bands, the core-size marker bands showed particularly large wavenumber downshifts on going from pH 8.7 to 5.3 with a transition midpoint at pH 6.5 in the absence of chloride ions. The chloride ions did not affect the spectrum at a pH below 5.3 and above 8.7 whereas an increase of chloride concentration at neutral pH caused spectral changes similar to those observed upon pH lowering. Analogous effects were also observed on the Raman intensity. In addition, the stretching mode of the bond between the heme Fe and proximal histidine shifted by -2 cm(-1) on going from pH 8.7 to 5.3. Decomposition of the nu(3) band revealed the presence of two components, which was confirmed by an isosbestic point in the absorption spectra. The observed spectral changes indicated the existence of alkaline and acidic forms of the enzyme. The pK of interconversion was 6.5, and it was increased by binding of chloride ions. The porphyrin core was slightly expanded in the acidic form compared to that in the alkaline form. A molecular mechanism of the porphyrin core expansion was proposed on the basis of the X-ray crystal structure. The pH-spectrum relationships obtained for the isolated enzyme were applied to in situ analysis of the state of myeloperoxidase in azurophilic granules of living neutrophils. The enzyme was stored in the acidic form and kept inactive in catalyzing HOCl production.

Chlorides↗

PubMed2000

Bronchial cuff pressure change caused by left-sided double-lumen endobronchial tube displacement.

PURPOSE: The bronchial cuff pressures (BCPs) of left-sided double-lumen endobronchial tubes (DLTs) manufactured by Rüsch and Mallinckrodt were measured in 80 patients when the tubes were withdrawn to compare the effect of tube design on BCP change. METHODS: During general anesthesia with muscle relaxation, the cephalad surface of the endobronchial cuff was positioned either 2.5 cm distal to the carina (Rüsch Group R-I; n = 20 and Mallinckrodt Group B-I; n = 20) or just below the carina (Rüsch Group R- II; n = 20 and Mallinckrodt Group B- II; n = 20) and the cuff was inflated to 35 cm H2O. The tube was then withdrawn in 0.5-cm steps until the cuff was 2.0 cm proximal to the carina, the position just before the capnogram or pressure-volume loop of tracheal lumen changed. The BCP at each step was measured. The rate of decrease in BCP was defined as the decrease of BCP divided by the length of displacement of DLT. RESULTS: The rates of decrease from the +2.5 cm position to the end point in Group B-I (7.7+/-0.8 cm H2O x cm(-1) and those from the most proximal acceptable position to the end point in Group B-II (19.5+/-4.8 cm H2O x cm(-1) were greater than those in Group R-I (6.9+/-0.9 cm H2O x cm(-1) (P<0.01) and in Group R-II (12.4+/-3.1 cm H2O x cm(-1)) (P<0.01), respectively. CONCLUSION: The BCP decreased in both of the Mallinckrodt and Rüsch DLTs, and the rates of decrease of the former were greater than those of the latter.

Adult↗

PubMed2000

Stromal sarcoma of the breast with lung metastasis successfully treated by radiotherapy: report of a case.

We report herein the case of a 42-year-old woman in whom a solitary lung metastasis from stromal sarcoma of the breast was effectively treated by radiotherapy. The original breast tumor had been extirpated in a local hospital, and she was subsequently referred to our outpatient clinic for nonsurgical treatment. Pathological examination of the breast tumor had confirmed a diagnosis of stromal sarcoma. Radiation and systemic chemotherapy for the remnant disease were administered at our hospital; however, 8 months later, local recurrence and a solitary lung metastasis were recognized on a chest X-ray. A second lumpectomy of the recurrent breast tumor along with radiation for the lung metastasis and systemic chemotherapy were performed. After a 4-year disease-free period, there is still no sign of recurrence. This case serves to demonstrate the effectiveness of radiotherapy for the treatment of lung metastasis from stromal sarcoma of the breast.

Adult↗

PubMed2000

Morphological study of the regeneration mechanism of acetic acid-injured colon crypts in the rat.

The regeneration mechanism of injured rat colonic mucosa with 1% acetic acid was certified in this study. The injured colons were studied periodically on experimental days 1, 3, 5, 7, 15, and 20 with light and scanning electron microscopy. Specimens were examined in paraffin sections stained with hematoxylin and eosin; crypts were isolated with the HCl digestion method; and three-dimensional stromal collagen tissue was prepared with the NaOH cell maceration method. Damage to the mucosal and submucosal layers peaked between the 1st and 3rd days with edema, regeneration, necrosis, and inflammation. The edema and inflammation subsided, and mucosal atrophy and crypt reduction remained at around 1 week. At 2 weeks the mucosa became thick, and crypts showed many branches in their lower two-thirds; and by 3 weeks the mucosa had recovered to almost normal. The ratio of number of crypts at the base and surface was almost 1.5 on the 15th day and 1.0 on the 20th day, suggesting that each branch progresses upward to create an independent crypt. We believe that the fission mechanism plays an important role in crypt repair after acetic acid injury of the colonic mucosa. As the proliferative zone of the colonic crypt is localized at the crypt base, fission of the crypt starting at the base and progressing up to the surface is the most reasonable and efficient mechanism for repair by increasing the number of crypts.

Acetic Acid↗

PubMed2000

Zinc tetraruthenated porphyrin binding and photoinduced oxidation of calf-thymus DNA.

The photooxidation of calf-thymus DNA has been investigated in the presence of a supramolecular tetraruthenated zincporphyrin (ZnTRP) sensitizer. A strong interaction of ZnTRP with DNA has been observed, exhibiting a gradual transition from a non-specific electrostatic binding mode to a more specific one at high DNA concentrations. Formation of O2(1delta(g)) has been detected from its near-infrared emission, after the excitation of ZnTRP in dioxygen-containing solutions. In the presence of DNA and dioxygen, ZnTRP promotes efficient photocatalytic oxidation of the 2'-deoxyguanosine sites, via their direct reaction with O2(1delta(g)), as in a previous work on the ZnTRP-photoinduced oxidation of the free nucleosides.

Animals↗

PubMed2000

Cochlear findings in the white spotting (Ws) rat.

White spotting (Ws) rats possess a c-kit gene mutation at the W locus, resulting in a variety of characteristics including a lack of intermediate cells of the stria vascularis. The present study employs a light microscope (LM), scanning (SEM) and transmission electron microscopes (TEM), diaminobenzidine (DAB) staining techniques and auditory brainstem response (ABR) to investigate the structure and function of the cochlea in 26 homozygous Ws/Ws rats aged 1-6 months. A slight thinning of the stria vascularis and moderate elevation of ABR threshold were about the only defects noted in 1 month animals, while older animals displayed various defects that tended to worsen with age. At 3 months LM revealed pigment granules in the basal turn of most animals, with a loss of pigmentation in the upper turns. The stria vascularis and organ of Corti tended to be well preserved in the lower, pigmented portion, while the upper, unpigmented portion showed severe strial degeneration and some outer hair cell loss. DAB staining revealed a well developed strial capillary net throughout the pigmented portion of the cochlea, with severe degradation in the unpigmented apical portion. ABR thresholds were slightly elevated over 1 month values. At 6 months great differences in degeneration were noted between right and left ears of the same animal.

3,3'-Diaminobenzidine↗

PubMed2000

Infantile convulsions with mild gastroenteritis.

The development of sensitive new molecular genetic techniques has led to the detection of rotavirus in cerebrospinal fluid, stools and throat swabs from patients with gastroenteritis with accompanying clinical symptoms similar to infantile benign convulsions. Small round structured virus (SRSV) has also been found in stools of patients with similar clinical symptoms by a new procedure. However, the mechanism by which these viral infections induce benign convulsions remains to be elucidated. The present paper reviews recent virological and clinical studies of seizures probably caused by gastroenteritis viruses including rotavirus, SRSV and other viruses.

Caliciviridae Infections↗

PubMed2000

Medical markup language (MML) for XML-based hospital information interchange.

Medical Markup Language (MML) has been developed over the last 6 years in order to create a set of standards by which medical data, within Japan and hopefully worldwide, can be stored, accessed and exchanged in any number of physical locates. The MML version 2.21 is characterized by XML as meta-language, module structure for each document and enhancement of linking function among documents. Data exchange specification has been also added for query and reply. MML instances are composed of MML header and MML body. The MML header includes information for data transmission, while MML body includes several module items. One module item contains two elements: document information and module content. Nine MML module contents are defined at the present time: patient information, health insurance information, diagnosis information, lifestyle information, basic clinic information, particular information at the time of first visit, progress course information, surgery record information and clinical summary information.

Clinical Laboratory Techniques↗

PubMed2000

Small Gtpase rab3A is associated with melanosomes in melanoma cells.

Rab3A is a small guanosine triphosphate (GTP)-binding protein that has been recently implicated in intracellular vesicle transport and the secretion of neurotransmitters in neuronal cells. We demonstrate here that Rab3A is associated with melanosomes in pigment cells. Rab3A as well as Rabphilin3A, a putative target protein of Rab3A, were detected in the melanosome fraction, purified from B16 murine melanoma cells by sucrose density gradient ultracentrifugation. In contrast, Rab GDP dissociation inhibitor (GDI), a GDP/GTP exchange protein for Rab3A, was found in the cytosol fraction. Further studies using confocal laser scanning microscopy and immunoelectron microscopy revealed that immunoreactive Rab3A is localized in conjunction with the melanosomal membrane. These results suggest the possibility of involvement of Rab3A-Rabphilin3A complex, regulated by Rab GDI, in the intracellular transport of melanosomes in pigment cells.

Adaptor Proteins, Signal Transducing↗

PubMed2000

An objective comparison of four digital intra-oral radiographic systems: sensitometric properties and resolution.

OBJECTIVES: To compare the sensitometric properties and resolution of four digital intra-oral radiographic systems. METHODS: Three CCD-based systems were evaluated, RVG-4 (Trophy Radiologic, Paris, France) CDR (Schick Technologies Inc, Long Island, NY, USA) and Dixel (Morita, Kyoto, Japan) and a photostimulable phosphor system (Digora, Soredex-Orion, Helsinki, Finland). The sensitometric properties were determined by measuring the gray levels at increasing exposures without making any gray-scale adjustments. MTF was measured using images of a 10 microns width slit inclined to the long and short axes of the detectors. RESULTS: The CCD-based systems showed a linear relationship between exposure and gray level although there were some differences in sensitivity. In RVG-4, the gray level saturated at a lower exposure. Digora showed a logarithmic relationship at uniform exposure. However, there was a linear relationship when it was exposed below the calibration dose. The MTF was highest with RVG-4 and the lowest with the Digora. CONCLUSIONS: Each system has its own specific properties; RVG-4 has the highest resolution with the narrowest latitude, whereas Digora has the wider latitude but the lowest resolution.

Absorptiometry, Photon↗

PubMed2000

Clinical significance of serum soluble IL-2R levels in patients with adult T cell leukaemia (ATL) and HTLV-1 carriers.

The levels of soluble IL-2Ralpha (sIL-2Ralpha) in serum were measured in HTLV-1 carriers and ATL patients in order to evaluate their possible correlation with clinical status. Mean sIL-2R levels in ATL patients were found to be 9704 U/ml for the acute/lymphoma type, 1961 U/ml for the chronic type and 788 U/ml for the smouldering type. The level for asymptomatic HTLV-1 carriers was 475 U/ml, and 165 U/ml for healthy young adult HTLV-1- controls. The serial measurement of sIL-2R in ATL patients, healthy HTLV-1 carriers, and HTLV-1 carriers with diseases other than ATL showed a good correlation between serum levels of sIL-2R and the pathophysiological status of disease. Furthermore, an increase in the sIL-2Ralpha level in serum indicated the exacerbation of HTLV-1 infection and autoimmune diseases. The measurement of sIL-2Ralpha levels is therefore a very useful parameter for determining disease status.

Adult↗