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Biomedical subjects

Y Ando

Publications and source records attributed to Y Ando.

At least 235 records · Page 13Linked to original sources
PubMed1998

Oxidative stress and amyloidosis.

From recent findings concerning free radical injury in several types of amyloidosis, it appears that free radical injury is involved either amyloid formation or in post-fibrillar modification. As we show in this review, among the more than 20 different types of amyloidosis, only a few types of amyloidosis present direct evidence of free radical involvement in amyloid formation. However, if we search further for other types of amyloidosis, other important information on free radical injury may be forthcoming. Free radical injury is probably central for the toxic properties of amyloid deposits.

Alzheimer Disease↗
PubMed1998

Monitoring of inhibitors of enzymatic amplification in polymerase chain reaction and evaluation of efficacy of RNA extraction for the detection of hepatitis C virus using the internal control.

Inhibitors of enzymatic amplification in serum may cause false-negative results for direct detection of hepatitis C virus (HCV) by polymerase chain reaction (PCR). This study was undertaken to demonstrate the importance of the internal control in a PCR assay for detection of HCV-RNA to monitor false-negatives due to inhibitors. HCV-RNA was extracted using RNA extraction kit (SepaGene RV-R, Sanko Junyaku) and a prototype instrument for automated specific capture of HCV-RNA with probes and magnetic bead/fluid separation (Roche Molecular Systems). The extracted HCV-RNA and internal control were detected by an automated PCR machine (Cobas Amplicor, Roche Diagnostic Systems). Addition of hemoglobin (up to 4.5 g/l) to the sera followed by RNA extraction with SepaGene RV-R had no inhibitory effect on the detection of either HCV-RNA or the internal control. In contrast, addition of heparin to the sera showed an inhibitory effect with a dose-dependent manner on the detection of both HCV-RNA and the internal control, with a greater effect at lower copy number of HCV. When HCV-RNA was extracted by the automated system, the inhibitory effect of heparin was successfully eliminated. In the assays of 65 serum samples positive for anti-HCV antibodies, positivity for the internal control indicated efficient amplification and validated 14 negative and two equivocal results for detection of HCV-RNA. Detection of the internal control was negatively correlated with viral copy number in sera suggesting competitive inhibition of high viral copy number on amplification of the internal control. Extraction, co-amplification and detection of the internal control appears useful for estimating effects of inhibitors on amplification in each assay for the detection of HCV-RNA, and for evaluating efficacy of RNA extraction methods.

Enzyme Inhibitors↗
PubMed1998

Patient information exchange guideline MERIT-9 using medical markup language MML.

To realize clinical data exchange between healthcare providers, there must be many standards in many layers. Terms and codes should be standardized, syntax to wrap the data must be mutually parsable, then transfer protocol or exchange media should be agreed. Among many standards for the syntax, HL7 and DICOM are most successful. However, everything could not be handled by HL7 solely. DICOM is good for radiology images, but, other clinical images are already handled by other "lighter" data formats like JPEG, TIFF. So, it is not realistic to use only one standard for every area of clinical information. For description of medical records, especially for narrative information, we created SGML DTD for medical information, called MML (Medical Markup Language). It is already implemented in more than 10 healthcare providers in Japan. As it is a hierarchical description of information, it is easily used as a basis of object request brokering. It is again not realistic to use MML solely for clinical information in various level of detail. Therefore, we proposed a guide-line for use of available medical standards to facilitate clinical information exchange between healthcare providers. It is called MERIT-9 (MEdical Records, Images, Texts,--Information eXchange). A typical use is HL7 files, DICOM files, referred from an MML file in a patient record, as external entities. Both MML and MERIT-9 are research projects of Japanese Ministry of Health and Welfare, and the purpose is to facilitate clinical data exchanges. They are becoming to be used in technical specifications for new hospital information systems in Japan.

Hospital Information Systems↗
PubMed1998

[Is medical linac suitable for high-precision stereotactic irradiation?: investigations in geometrical accuracies of gantry and couch].

Linac-based radiosurgery has many advantages over the gamma knife, including low initial cost and no need of source replacement. On the other hand, most of the medical linacs currently in use were not originally designed to be applied for radiosurgery, and, therefore, careful quality assurance programs are required. In the gantry-head of a linac, a small CCD video camera is mounted in a position optically identical to that of the x-ray source. The video signal from the camera was digitalized to be evaluated for geometrical errors. A metal ball fixed to the stereotactic base frame via XYZ-sliding rods was used as a simulated target. Displacements of the target from the isocenter were measured during rotation of the gantry. Displacements in the gantry-rotation plane were satisfactorily small, while those perpendicular to it were maximal at gantry position angles of 0 degree and 180 degrees. This error night be caused by gravitational vending of the heavy gantry head. Although other major errors of the linac were within one millimeter, the center of coach rotation around the isocenter did not coincide with the center of gantry rotation, probably owing to gravitational vending. Special care should be taken when very small collimators are employed.

Quality Control↗
PubMed1998

[Analysis of microsatellite alteration in colorectal cancer].

We investigated the possible correlation between the microsatellite alterations (replication error: RER, and loss of heterozygosity: LOH) and clinicopathologic factors and survival in colorectal cancer. A total of 78 colorectal cancers was examined for microsatellite alteration at three microsatellite loci containing D2S123, D18S58 and C117-703. RER is considered positive when at least one microsatellite locus is detected. RER was positive in 28.2%, and the respective positivity was 12.8%, 15.3% and 11.5%. The positivity of LOH was 6.4%, 10.3% and 19.2%, in that order. RER-positive cancers were more significantly found in the proximal colon than the distal colorectum. Node-negative colorectal cancers were more noted in RER (+)-positive cancers. Multivariate analysis showed that LOH in D18S58 locus and RER in CI17-703 locus were independent prognostic factors.

Aged↗
PubMed1998

[Nuclear DNA content of parathyroid tumor with hyperparathyroidism].

It is not easy to make a differential diagnosis among adenoma, hyperplasia and carcinoma with hyperparathyroidism (HPT). We investigated the flowcytometric nuclear DNA content and analysis of cell cycle for 29 patients (39 parathyroid glands) with HPT and 16 normal parathyroid glands at the Department of Surgery II, Fukushima Medical College. Flowcytometry was performed by EPICS 751 flowcytometer (Coulter Co.) in paraffin-embedded tissue. Each fraction of cell cycle was analyzed by the PARAI software program. All controls and secondary hyperplasia showed diploid. Aneuploid pattern was found in 27.6% of all HPTs (50% of carcinomas, 30% of adenomas and 6.7% of primary hyperplasia). The S phase fraction (SPF) and proliferative index (PI) were increased in carcinomas. PIs, especially the fraction of G2M, in primary and secondary hyperplasias were more decreased than those in normal controls and adenomas. Preoperative intact-PTH, c-PTH, ionized calcium, ALP and weight of parathyroid gland had no significant correlation with DNA ploidy, DNA index and SPF. PI had tended to correlate only with the weight of parathyroid gland. When DNA content shows aneuploid, high SPF or PI in parathyroid adenoma and hyperplasia, strict follow-up is required because of the malignant potential. If G2M or PI is lower, we should pay attention not to leave any remaining glands in parathyroidectomy in the light of hyperplasia.

Adenoma↗
PubMed1998

[The clinical features of 9 cases of intraocular malignant lymphoma of oculocerebral origin].

We reviewed a series of 13 eyes in 9 cases of intraocular lymphoma with or without intracranial involvement during the past 15 years. The cases were characterized by moderate or no inflammation in the anterior ocular segment and by the presence of vitreous opacity and fundus lesions. Contrary to the accepted view that this disease simulates uveitis with various manifestations, the fundus lesions in the present series showed disseminated or tumorous subretinal lesions suggestive of proliferation of tumor cells. Only a few cases showed retinal vasculitis or retinal exudates. Electrooculograms showed findings suggestive of widespread impairment of the retinal pigment epithelium. Because of poor prognosis and sensitivity to radiation, we advocate early diagnosis and treatment for this disease.

Adult↗
PubMed1998

Mesenteric venous thrombosis: a case report.

We describe herein a 41-year-old man who complained of abdominal pain. He underwent surgery, and the diagnosis of mesenteric venous thrombosis was made. The small intestine, mainly the jejunum, presented necrosis on laparotomy, and a 155-cm long segment of it was successfully resected. Anticoagulant therapy was initiated postoperatively, and he is well at present.

Adult↗
PubMed1998

[IS&C image viewing and conversion software for Macintosh computer].

Although standardized data-transmission protocols such as DICOM are very beneficial, on-line transmission on images is often difficult to establish because of cost or security concerns. On the other hand, media-based data exchange is simple and adequate for the private use of medical images. We developed a viewing software program for medical images stored in magneto-optical disks with IS&C standard format. It displays images with gray-scale tone and stores them in Macintosh PICT format. The software is available for personal use from the first author.

Diagnostic Imaging↗
PubMed1997

The Clinical Value of Microsatellite Instability and a Loss in Heterozygosity in Sporadic Breast Cancers.

We analyzed loss of heterozygosity (LOH) and microsatellite instability (MI) in 108 cases of sporadic breast cancers using 22 microsatellite markers on 12 chromosomes. LOH was frequently seen in 1p(13%), 6p(18%), 8p(11%), 11p(18%), 13q(21%),16q(31%), 17p(44%) and 17q(29%). Individual patients were scored according to the degree of LOH at the above eight chromosomal markers. Patients with no LOH were scored as 1, patients with one to three LOH were scored as 2, and patients with four or more LOH were scored as 3. A high LOH score correlated with a high histological grade (p=0.019) and a poor prognosis (p=0.0035). Eleven(10.2%) of 108 patients with breast cancer showed MI, with 6 cases showing MI at a single locus and 5 at multiple loci. Of the 11 MI-positive patients only one had lymph node involvement(p=0.015), none had histological grade 3 disease, and MI-positive patients tended to have a better prognosis than MI-negative ones. These data suggest that MI may be an early event in mammary tumorigenesis, and that LOH occurs at a later stage. The LOH score may be a useful prognostic marker of operable breast cancer.

Journal Article↗
PubMed1997

Changes in nitrite and nitrate (NO2-/NO3-) levels in cerebrospinal fluid of patients with multiple sclerosis.

To compare the change in nitric oxide (NO) metabolism in patients with multiple sclerosis (MS) in different clinical stages, such as exacerbation, remission, and 1-2 months after methylpredonisolone administration, we measured the nitrite and nitrate (NO2-/NO3-) levels in the cerebrospinal fluid (CSF). In the extreme stage of MS exacerbation, those levels were remarkably elevated, compared with those both after methylpredonisolone administration and remission. These results suggest that, in addition to MRI study, measurement of NO metabolites in the CSF may give information to help us understand the activity of MS and effect of drugs on the disease.

Adult↗
PubMed1997

Detection of different forms of variant transthyretin (Met30) in cerebrospinal fluid.

To detect the variant transthyretin (TTR; Met30) in cerebrospinal fluid (CSF) of familial amyloidotic polyneuropathy (FAP) patients, we have applied a new method using a centrifugal concentrator device and electrospray ionization mass spectrometry (ESI-MS). Only 100 microl of CSF and 30 microl of the antibody for TTR was needed for the analysis. After preparation of the samples with anti-TTR antibody, they were passed through a 1000 kDa cut-off centrifugal concentrator which retained the antibody. By analyzing the obtained filtrate with ESI-MS, three predominant forms of normal and their variant forms of TTR were detected in CSF samples. TTR (Met30), with a molecular weight 32.0 Da higher than the normal form of TTR, was found in all FAP patients' materials. Although the ratio of the three major peaks of TTR were different in each individual, they were always found in CSF and sera. This method will contribute to make a diagnosis of neurologic disorders having a mutant protein in CSF as well as serum.

Adult↗
PubMed1997

Down regulation of a harmful variant protein by replacement of its normal protein.

To compensate for the hypoprotein and hypoalbuminemia of familial amyloidotic polyneuropathy (FAP) patients, 800 ml of fresh frozen plasma (FFP) was intravenously administered and change in total and variant transthyretin (TTR) levels were measured in the plasma. After injection of FFP, total plasma TTR levels were elevated and variant TTR levels decreased from 24 to 48 h, accompanied by an elevation of plasma total protein, albumin levels and TTR levels. To elucidate the mechanism of this phenomenon, a large amount of purified normal TTR from normal human plasma was intravenously injected in mice and FAP patients. By intravenous injection of 3 mg of the purified TTR to C57Black6, the expression of TTR mRNA decreased from 6 to 24 h post injection, and gradually increased up to 48 h post injection. After injecting 400 mg of normal TTR in each of 3 FAP patients, total plasma TTR levels were elevated and variant TTR levels decreased significantly from 24 to 48 h. These results suggested that down regulation of the harmful protein by replacement of its normal form of the protein occurred by this method. This phenomenon should be applied as the basis for one of the useful methods for decreasing the harmful proteins in the circulation.

Adult↗