Biomedical subjects

Y Ando

Publications and source records attributed to Y Ando.

At least 181 records · Page 10Linked to original sources

PubMed1999

AVP inhibits LPS- and IL-1beta-stimulated NO and cGMP via V1 receptor in cultured rat mesangial cells.

The present study examined how arginine vasopressin (AVP) affects nitric oxide (NO) metabolism in cultured rat glomerular mesangial cells (GMC). GMC were incubated with test agents and nitrite, and intracellular cGMP content, inducible nitric oxide synthase (iNOS) mRNA, and iNOS protein were analyzed by the Griess method, enzyme immunoassay, and Northern and Western blotting, respectively. AVP inhibited lipopolysaccharide (LPS)- and interleukin-1beta (IL-1beta)-induced nitrite production in a dose- and time-dependent manner, with concomitant changes in cGMP content, iNOS mRNA, and iNOS protein. This inhibition by AVP was reversed by V1- but not by oxytocin-receptor antagonist. Inhibition by AVP was also reproduced on LPS and interferon-gamma (IFN-gamma). Protein kinase C (PKC) inhibitors reversed AVP inhibition, whereas PKC activator inhibited nitrite production. Although dexamethasone and pyrrolidinedithiocarbamate (PDTC), inhibitors of nuclear factor-kappaB, inhibited nitrite production, further inhibition by AVP was not observed. AVP did not show further inhibition of nitrite production with actinomycin D, an inhibitor of transcription, or cycloheximide, an inhibitor of protein synthesis. In conclusion, AVP inhibits LPS- and IL-1beta-induced NO production through a V1 receptor. The inhibitory action of AVP involves both the activation of PKC and the transcription of iNOS mRNA in cultured rat GMC.

Animals↗

PubMed1999

Identification of a new transthyretin variant (Ile49) in familial amyloidotic polyneuropathy using electrospray ionization mass spectrometry and nonisotopic RNase cleavage assay.

Mutation of the transthyretin (TTR) plasma protein and gene in a Japanese patient with amyloid polyneuropathy was investigated by electrospray ionization mass spectrometry (ESI-MS) and nonisotopic RNase cleavage assay (NIRCA), respectively. ESI-MS analysis showed normal TTR peaks and additionally a variant TTR with 12-dalton-higher molecular weight than normal TTR. NIRCA suggested that the mutation existed near either the 5' or 3' end of exon 3. Direct DNA sequencing revealed both a normal ACC (threonine) and a variant ATC (isoleucine) at codon 49, which was located near the 5' end of exon 3. The molecular weight shift of this mutation was 12 D, consistent with the result of ESI-MS.

Aged↗

PubMed1999

Caries risk factors among three-year old children in Chiba, Japan.

In order to predict the factors which affect the occurrence of dental caries in children after the age 18-months, we analyzed the relationship between the increment of the decayed, missing, and filled teeth (dmft) in children from 18-months to three-years of age and caries risk factors. Subjects were 392 infants who received both an 18-month-old check-up and a three-year-old check-up in Chiba city. Stepwise multiple logistic regression analyses were used to analyze the results with the increment of the dmft by various combinations of independent variables (sex, order of birth, sweets intake, beverage intake, tooth brushing and feeding). The most predictive factors for the increment of the dmft in upper anterior and molar were "breast feeding" and "bottle feeding" respectively. From these results, we concluded that bottle feeding and breast feeding were the risk factors for the increment of the dmft from the age of 18-months to three years.

Child, Preschool↗

PubMed1999

Analysis of transthyretin amyloid fibrils from vitreous samples in familial amyloidotic polyneuropathy (Val30Met).

The aim of the present study was to analyze the forms of wild type and mutated monomeric transthyretin (Val30Met) in the amyloid fibrils of patients with familial amyloidotic polyneuropathy by electrospray ionization mass spectrometry (ESI-MS). The solubility of amyloid fibrils from the vitrectomized samples was examined to determine the appropriate solution for ESI-MS. ESI-MS analysis revealed that heterozygotic Val30Met amyloid fibrils contained 14.6 +/- 7.5% normal TTR. In all samples, 3 different types of variant ATTR could be identified: Full length ATTR, and -57, and -157 (or 156) Da from ATTR Val30Met were found. The two peaks showing -57, and -157 (or 156) Da from ATTR Val30Met corresponded to the -Gly, and -Gly-Pro sequences of ATTR Val30Met from the N-terminal. The results illustrate the heterogeneity of ATTR amyloid deposits and this method may be very useful for analyzing amyloid fibrils in ATTR related amyloidosis.

Aged↗

PubMed1999

Gastrointestinal dysfunction in familial amyloidotic polyneuropathy (ATTR Val30Met)--comparison of Swedish and Japanese patients.

The aim of the present study was to compare the clinical symptoms of Swedish and Japanese patients with familial amyloidotic polyneuropathy (ATTR Val30Met), especially gastrointestinal disturbances, and to correlate the findings with survival. Seventy-three Swedish and 47 Japanese patients were available for the study. Thirty-two Swedish and 7 Japanese patients had undergone liver transplantation. The mean age at onset was 50 for Swedish and 35 for Japanese patients (P < 0.001; non-transplanted patients). Fifty-five percent of Japanese patients had gastrointestinal disturbances from onset, compared to 22% of Swedish patients (P < 0.05; whole population). The Swedish patients average survival after the onset was significantly longer than Japanese patients (P < 0.05; non-transplanted patients). An early onset of gastrointestinal symptoms was correlated to a decreased survival for Swedish, but not for Japanese patients. Age at onset was not correlated to survival neither for Swedish nor for Japanese patients. We conclude that the clinical expressions of familial amyloidotic polyneuropathy ATTR Val30Met are different in Swedish and Japanese patients. The survival after the onset was shorter for Japanese patients, who also had an earlier onset of gastrointestinal disturbances, especially diarrhea than Swedish patients.

Adolescent↗

PubMed1999

Impact of age and amyloidosis on thiol conjugation of transthyretin in hereditary transthyretin amyloidosis.

Variant forms and post-translational modifications of transthyretin (TTR) can be identified by electrospray ionisation mass spectrometry (ESI-MS). The aim of the present study was to investigate thiol conjugation of transthyretin and it's relation to age and symptomatic amyloid disease in different populations of variant TTR carriers. Plasma samples from 70 individuals from Denmark, Argentina, Sweden and Japan, with 2 different TTR mutations were analysed. The percentage cysteine (Cys) conjugated wild and variant TTR were calculated from the corresponding peaks of the spectra, and multiple regression analysis was employed to disclose relationships between age, symptomatic amyloid disease and origin. Age, origin and presence of symptomatic disease, were found to be independent factors related to transthyretin conjugation. A higher percentage of conjugated to unconjugated TTR was disclosed in symptomatic, but not in asymptomatic carriers. In summary: Thiol conjugation of TTR is dependent on age and presence of symptomatic amyloid disease. Furthermore, it varies between different populations. Variant TTR is more susceptible to thiol conjugation than the wild type. Post-translational factors may be related to amyloid formation and/or toxicity.

Adolescent↗

PubMed1999

Endocrine cells in the upper gastrointestinal tract in relation to gastrointestinal dysfunction in patients with familial amyloidotic polyneuropathy.

Gastrointestinal (GI) dysfunction is a common complication of familial amyloidotic polyneuropathy (FAP). In previous reports, a decreased content of small and large intestinal endocrine cells has been found in patients with FAP and it has been suggested that this may contribute to the development of GI disturbances. The aim of the present study was to investigate the endocrine cell content in the stomach and duodenum of FAP patients, and to correlate the findings with gastric emptying. Fifteen patients with FAP were included in the study. Twenty-eight subjects with macroscopically and histologically normal mucosa were used as controls for endocrine cell contents and 14 healthy subjects for gastric scintigraphy. The endocrine cells were identified by immunohistochemistry and quantified with image analysis. Gastric emptying time was detected by scintigraphy and endoscopy. The number of chromogranin A-immunoreactive (IR) cells was reduced in all investigated parts of the GI tract except bulbus duodeni. Gastrin/CCK cell content was reduced in duodenum, but tended to be increased in antrum of the stomach (P = 0.07). Otherwise, the content of all other endocrine cells types in the upper GI tract was reduced compared with controls. A correlation with malnutrition was found for gastric inhibitory polypeptide and secretin cell content in bulbus duodeni. Gastric scintigraphy disclosed delayed gastric emptying of solid food, but the finding was not correlated to the decreased content of neuroendocrine cells. The severity of endocrine cell depletion was not correlated to duration of GI disturbances. The present study showed that the endocrine cells of the stomach are affected in FAP patients and that the abnormalities in the upper GI endocrine cells occur early during the course of the disease.

Adult↗

PubMed1999

Liver transplantation in transthyretin familial amyloid polyneuropathy: first report from Argentina.

This is the first report from Argentina of liver transplantation in patients with transthyretin related familial amyloidotic polyneuropathy. The aims of the study were to analyze the clinical characteristics of this new focus and evaluate the postoperative complications and long term follow up. Five of ten patients evaluated underwent liver transplantation. During the waiting period the polyneuropathy disability score in each patient progressed one or two stages. Pretransplant modified body mass index was 723. The procedure was done with full size grafts in four cases and a split right graft in one. All patients presented postoperative complications related to disease: severe edema of the legs, recurrent choledochal lithiasis, postoperative hernia, necrotizing fasciitis and ischemic rectosigmoidal perforation. Assessment of three patients after 20 months of transplantation showed improvement in somatic and mental symptoms. No improvement was noted in cardiac denervation and gastric stasis. Liver transplantation is a rational therapeutic option for transthyretin familial amyloidotic polyneuropathy in Argentina and should be indicated in earlier stages of the symptomatic disease to reduce the postoperative morbidity and mortality. Family studies and follow up of asymptomatic carriers will define the epidemiological behavior in this country and facilitate early therapeutic intervention.

Adult↗

PubMed1999

[Clinical computer applications in the radiology department].

The information society is currently developing. In the field of radiology, the PACS (picture archiving and communication system) and teleradiology are widely employed in medical practice. The Ministry of Health and Welfare (MHW) reported that physicians should consider some problems in Telemedicine in December 1997. The technology of storage media is improving and we encourage the standardization of data formatting and the transmission protocol to utilize medical electronic information. Several standards exist in the medical imaging field, the DICOM (digital imaging and communications in medicine) standard, the IS&C (image save and carry) standard and the Common Standard that the Medical Information System Development Center (MEDIS-DC) defined for the electronic storage. The PACS requires high transmission speed, integrated services digital network and an asynchronous transfer mode switching system. The MHW needed a technical requirement for the electronic image storage without films in March 1994. The requirement was divided into three parts, (1) security, (2) long-term reproducibility, (3) common usage. The MEDIS-DC published the Common Standards for electronic storage in 1996. When we use the PACS via network, we must consider the security. The present network may have low security, and falsification, such as illegal login may occur. In the future, these problems will be solved, and the network-wide PACS will likely become a commonly used system.

Computer Storage Devices↗

PubMed1999

[Factors related to the QT prolongation in chronic renal failure].

QT prolongation, a risk factor for arrhythmia and cardiac death, is observed in uremic patients. Though hypocalcemia, autonomic nerve dysfunction and cardiac hypertrophy are assumed to cause the uremic QT prolongation, the exact mechanism remains unspecified. We therefore examined factors related to the QT interval in chronic renal failure (CRF). Corrected QT interval (QTc) was significantly prolonged in CRF just before the induction of dialysis therapy (group A) compared with nephrotic syndrome with the intact or mildly impaired renal function (group B). QTc was also prolonged in acute renal failure (group C). Cardio-thoracic ratio, serum albumin and Ca correlated with QTc in group A, but not in B or C. A single HD session in group A failed to shorten QTc, despite a significant increase in serum Ca++. Autonomic dysfunction did not appear to be a major determinant of QT prolongation, since QTc was not different between diabetics and non-diabetics in group A and in chronic HD patients (group D). In group D, QTc did not correlate with SV1 + RV5 on ECG or left ventricular wall thickness (LVWT) on echocardiography. In another group of chronic HD patients (group E), there was no significant correlation between QTc and the parameters of left ventricular mass, plasma brain natriuretic peptide (BNP). However, in the patients subjected to repeated echocardiography in group D, QTc and LVWT changed in parallel. In a retrospective analysis of QTc in group D, QTc was maximally prolonged at the time of starting HD therapy, and gradually improved in the following 1-5 years in both diabetics and non-diabetics. In contrast, chronic CAPD patients (group F) revealed no improvement of QTc. Thus, uremic QT prolongation cannot be explained simply by any of the previously assumed factors, but appears to be affected by multiple factors, which are partially correctable by chronic HD therapy.

Autonomic Nervous System Diseases↗

PubMed1999

Pharmacological analysis of etoposide in elderly patients with lung cancer.

To analyze the pharmacological characteristics of etoposide in elderly patients, we conducted a Phase I trial of a 14-day administration of oral etoposide on 12 chemotherapy-naive patients, ages 75 years or older, with lung cancer. The pharmacological profiles of etoposide in elderly patients were compared with those of younger patients in our previous studies (H. Minami et al., J. Clin. Oncol., 11: 1602-1608, 1993; H. Minami et al., J. Clin. Oncol., 13: 191-199, 1995; Y. Ando et al., Jpn. J. Cancer Res., 87: 200-205, 1996). The sigmoid Emax model and logistic regression model were used for pharmacodynamic analysis. The maximum tolerated dose for elderly patients was 75 mg/body/day. The apparent oral clearance in elderly patients was 37+/-10 (mean +/- SD) ml/min, which was not different from that in younger patients (44+/-12 ml/min). The area under the concentration-versus-time curve of etoposide over the treatment period (total AUC) that produced a 50% decrease in absolute neutrophil counts was significantly different between elderly and younger patients, 14.3+/-2.5 and 21.6+/-2.7 mg x min/ml, respectively (P = 0.048). The incidence of grade 3 or 4 neutropenia at total AUC of 30 mg x min/ml (corresponding to a plasma concentration of 1.5 microg/ml for 14 days) was 81% in elderly patients but only 48% in younger patients. Although there was no pharmacokinetic difference between elderly and younger patients, equivalent exposure to etoposide resulted in severer myelosuppression in elderly patients. These findings suggest that prolonged etoposide administration with plasma concentration maintained at 1-2 microg/ml may cause severe myelotoxicity in elderly patients.

Administration, Oral↗

PubMed1999

Expression of cholesterol 7alpha-hydroxylase and delta(4)-3-ketosteroid 5beta-reductase genes in rat pancreatic hepatocyte-like cells.

Hepatocyte-like cells have been observed in the pancreas of the rat. We examined the bile acid biosynthetic function of these cells to determine whether they were real hepatocytes. This study investigated the existence of two liver-specific enzymes involved in bile acid biosynthesis (cholesterol 7alpha-hydroxylase and delta(4)-3-ketosteroid 5beta-reductase) in the hepatocyte-like cells. We could demonstrate cholesterol 7alpha-hydroxylase activity and its circadian rhythm in the hepatocyte-like cells. Northern blot analysis demonstrated the expression of messenger RNA for the 7alpha-hydroxylase and delta(4)-3-ketosteroid 5beta-reductase in the pancreatic hepatocyte-like cells. To measure the amount of the messenger RNA, we used the competitive polymerase chain reaction method for the 7alpha-hydroxylase. This quantitation revealed the existence of a circadian rhythm of cholesterol 7alpha-hydroxylase messenger RNA in the hepatocyte-like cells. These results indicated that bile acid biosynthesis was performed in the pancreatic hepatocyte-like cells as noted as in the liver parenchymal cells.

Animals↗

PubMed1999

[Hard-copy (film) versus soft-copy (CRT) reading performance between compressed and uncompressed images: SOLs in abdominal CT images].

The objective of this study was to examine the feasibility of soft-copy (CRT) reading and suitable compression. Forty abdominal CT images with a space-occupying lesion (SOL) in liver and 40 normal images were selected for receiver-operating-curve (ROC) analysis. Each image was compressed by JPEG extended mode into 1/10 its original capacity, and then an expanded image was printed on film. Ten radiologists evaluated the presence of liver SOLs (primary and secondary tumors) on soft-copy (CRT) and hard-copy (film) images. Each radiologist reviewed four types of images (original and compressed hard-copy and original and compressed soft-copy images). Values of the area under the curve in the various ROC analyses were 0.858 (FILM) and 0.842 (CRT) for original images and 0.879 (FILM) and 0.846 (CRT) for compressed images. The results of ROC analysis showed better reading performance with hard-copy than soft-copy images, but the difference was not statistically significant. Compressed images showed a higher value (0.879) than original images (0.858), a difference that was statistically significant (p < 0.029) by the paired t-test but not by the jackknife method. The results indicate that soft-copy reading is a clinically acceptable alternative to hard-copy reading. We have had no difficulty in reading abdominal CT images compressed to 1/10 of the original size by the JPEG method. This study was supported in part by a grant from the Japanese Ministry of Health and Welfare.

Humans↗

PubMed1999

[Inhibitory effects of therapeutic reagents on the PCR detection of hepatitis C virus in serum and their elimination by RNA extraction methods].

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 inhibitory effects of the therapeutic reagents on the PCR detection of HCV and to evaluate the efficacy of their elimination by RNA extraction methods. RNA was extracted using a manual method based on organic extraction and precipitation of RNA (SepaGene RV-R, Sanko Junyaku) or an automated system based on specific capture of HCV-RNA with probes and magnetic bead/fluid (B/F) separation (Roche Molecular Systems). When RNA was extracted by SepaGene RV-R from serum containing 10(5) copies per ml of HCV and amplified for HCV-RNA in the presence of hemoglobin, bilirubin, or heparin by Amplicor HCV (Roche Molecular Systems), results tended to be negative. In addition to these, two therapeutic reagents, ATP and dextran sulfate sodium were also found to have inhibitory effects. When ATP at concentrations up to 5 mM was added to the sera and RNA was extracted with SepaGene RV-R, there were no inhibitory effect on the detection of either HCV-RNA or the internal control. In contrast, when dextran sulfate sodium up to 1 mM was added to the sera, there was a dose dependent inhibitory effect on detection of both HCV-RNA and the internal control. When HCV-RNA was extracted by the automated system, the inhibitory effect of dextran sulfate sodium was successfully eliminated. In conclusion, dextran sulfate sodium and ATP were newly identified as inhibitors that may be present in serum, and the efficacy of eliminating these substances varied among RNA extraction methods.

Adenosine Triphosphate↗

PubMed1999

[A case of malignant hypertension in whom steroid improved renal function].

We report a case whose renal failure was due to malignant hypertension and in whom steroid facilitated the recovery of renal function. The patient, a 41-year-old man, was admitted to our hospital because of malaise and macrohematuria. On admission, his blood pressure was 270/160 mmHg. The plasma renin activity (PRA) and aldosterone were markedly elevated. Chest X-ray, echo cardiography and electrocardiogram revealed marked hypertrophy. Hypertensive retinopathy and arteriosclerotic change were noted on ophthalmoscopy. Because of renal dysfunction (blood urea nitrogen 45.6 mg/dl, serum creatinine 4.9 mg/dl with massive proteinuria and increased FENa, renal biopsy was performed on the 8th clinical day. The specimens showed slight proliferation of mesangial cells with mesangiolysis and interstitial cell infiltration, in addition to marked arteriosclerosis and partial collapse of the glomerular tuft. After the administration of a Ca antagonist and angiotensin converting enzyme inhibitor (ACE-I), his mean blood pressure decreased to 100-130 mmHg, and urinary protein decreased as well. Nevertheless, renal dysfunction remained unchanged during the following 3 weeks. Thus, prednisolone (PSL, 30 mg/day) was administered on the 22nd clinical day and renal function improved thereafter without a significant change in blood pressure. The improved renal function was maintained after PSL tapered off on the 184th clinical day. It is suggested that PSL might be the therapy of choice in malignant hypertension, when the renal function has not been improved by anti-hypertensive treatment alone.

Adult↗

PubMed1999

Subjective duration of every three-year period for 3 to 18 years of age, estimated by students.

Results indicated that both subjective time durations, one day and three years, are well described by the normal distribution if the time scale is logarithmic rather than linear. A remarkable finding obtained here is that in reference to the mean subjective time duration of the junior high school (three years), the mean subjective time durations for each of the three-year periods before elementary school were significantly longer than unity (about 1.2), and the subjective duration of the three year period of the senior high school is significantly shorter (about 0.8). When subjects transferred to other elementary schools at 6 to 11 years of age, the mean subjective time duration of the periods below 11 years of age was much longer, more than 1.3.

Adolescent↗

PubMed1998

Post-translational modification of transthyretin in plasma.

To determine the behavior of transthyretin (TTR) in blood circulation, TTR purified from normal subjects' plasma was injected to rats, and blood and urine were collected time dependently. Although TTR in plasma was proven to be a predominantly cysteine (Cys) conjugated form by electrospray ionization mass spectrometry (ESI-MS) analysis, it was gradually converted into free, 32 Da (dihydroxylation), 80 Da (phosphorylation), and 306 Da (glutathionylation), increased forms in molecular weight of TTR. The plasma levels of TTR were decreased in a time-dependent manner with the half life of 72.4 min. No secretion of TTR into the urine was observed by ESI-MS. In conclusion, this method can be simply performed without loading a radioactive molecule to the targeted protein. It offers a possibility to determine natural protein behaviors in the blood stream.

Animals↗

PubMed1998

Intramammary Extension of Breast Cancer: Diagnosis with MR Mammography.

Purpose: Intramammary extension of breast cancer was investigated using contrast-enhanced magnetic resonance (MR) imaging by comparing MR findings with the histopathology of specimens used for pretreatment planning. Materials and Methods: Thirty-nine breast cancers were examined. The dynamic protocol was performed with a 2- or 3-dimensional fast spin echo sequence (1.5 T), once before and 2-5 times immediately after Gd-DTPA administration with an original fat suppression technique. The findings were correlated with the histopathology. Results: All main tumors showed early enhancement. All with direct invasion histopathologically showed spicular enhancement. The four patients who had separate nodular enhancement showed satellite lesions histopathologically. Three-typed MR findings were found to be indicative of an intraductal component. Conclusion: Various forms of breast cancer were reliably demonstrated using MR imaging. MR imaging could be useful for the pretreatment planning for patients with breast cancer.

Journal Article↗