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Biomedical subjects

T Doi

Publications and source records attributed to T Doi.

At least 271 records · Page 15Linked to original sources
PubMed1994

Chiral separation of diniconazole, uniconazole and structurally related compounds by cyclodextrin-modified micellar electrokinetic chromatography.

Enantiomeric separation of the structural analogs, diniconazole and uniconazole, can be achieved by cyclodextrin (CD)-modified micellar electrokinetic chromatography (MEKC). The elution behavior of other structurally related compounds was therefore investigated and compared with that in high-performance liquid chromatography (HPLC) using a CD-bonded stationary phase. From the results, it was concluded that the benzene ring of the solute plays an important role in formation of CD complexes and chiral recognition in MEKC as well as in HPLC, although the enantioselectivity with the two methods was different. Nuclear magnetic resonance (NMR) data revealed different CD effects on the solute between the MEKC and HPLC models.

Chromatography↗
PubMed1994

Immunohistochemical study of the distribution of intercellular adhesion molecule-1 and lymphocyte function-associated antigen-1 in chronic type B hepatitis.

The expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) in the livers of 11 patients with chronic hepatitis B was studied immunohistochemically by light and electron microscopy to clarify the role of these adhesion molecules in tissue damage in chronic hepatitis B. On hepatocytes, ICAM-1 expression was confined to the bile canalicular surface when the liver inflammation was mild. In contrast, when the liver inflammation was severe, ICAM-1 was distributed on the entire surface of the hepatocyte, including the sinusoidal and lateral membranes; lymphocytes which were mostly positive for LFA-1, were often observed invading deeply among these hepatocytes. The degree of ICAM-1 expression on the hepatocytes was also related to the expression of HLA class 1 antigen. In liver showing diffuse expression of ICAM-1 on the hepatocytes, strong expression of HLA class 1 antigen was observed, and amounts of HBV in the liver were decreased. Diffuse expression of ICAM-1 and HLA class 1 antigen was mostly observed after acute exacerbation of liver inflammation. These results suggest that the ICAM-1/LFA-1 pathway is involved in the immunological mechanism responsible for liver cell damage in chronic hepatitis B.

Cell Adhesion Molecules↗
PubMed1994

Usefulness of magnetic resonance imaging for detecting intrasubstance tear and/or degeneration of lateral discoid meniscus.

In order to determine the usefulness of magnetic resonance imaging (MRI) for detection of intrasubstance tears or degeneration of the lateral discoid meniscus, we compared findings obtained with MRI with those of histological examination. Sixty-four symptomatic lateral discoid menisci were studied using MRI before surgical treatment. Of these, 18 (28%) met the criteria that MRI signals did not extend to the surface and that no visible tears were observable at arthroscopy. Findings of intrameniscal regions of high signal intensity and flattening in shape on MR images were found to represent intrasubstance tears or degeneration not detected at arthroscopy. Our findings thus demonstrate that MRI is more sensitive than arthroscopy in the detection of intrasubstance pathologies of the lateral discoid menisci.

Adolescent↗
PubMed1994

Characteristics of ventricular premature contractions and their clinical course.

One hundred patients with frequent (> 1,000 beats/day) ventricular premature contractions (VPCs) were followed for 4 years. All of the patients, except those with non-cardiac death (n = 8), were classified into 3 groups based on their outcome. Group A consisted of 29 patients with idiopathic VPCs who survived the study period. Group B consisted of 49 patients with underlying diseases who survived the study period. Group C consisted of 14 patients who suffered cardiac death. There was no significant difference in the daily number of VPCs. However, groups B and C had more patients with Lown grade 4a or 4b VPCs than group A. The mean coupling interval was significantly longer in group C than in group A, and the standard deviation of the coupling interval was significantly larger in group C than in group A. Forty patients underwent serial Holter monitorings to assess changes in the number of VPCs. VPCs spontaneously decreased in 13 patients, while the other 27 patients continued to have frequent VPCs. Most of these 13 patients were classified as Lown grade 2. The results suggest that in patients with frequent VPCs, longer and more varied coupling intervals may predict a poor prognosis, and Lown grade 2 may predict a spontaneous regression.

Adult↗
PubMed1994

[Analysis of the trends of mean birth weight at an obstetric facility in Osaka during the past 30 years (1962-1991)].

Annual trends of mean birth weight (MBW) at an obstetric facility in the city of Osaka were examined, based on the data in the delivery records for 30 years from January 1962 through December 1991. MBW at this facility had been decreasing during the years of 1975-1985, after being adjusted for parity (primipara/multipara) and the infants' sex. In addition, annual trends of the rate of intrauterine growth and mean gestational period, which are considered to be the two major processes to governing birth weight, were retarded or shortened during almost the same time. Among some possible factors with causal impacts on birth weight, the advance in maternal age, the lowered parity, and the increase in premature delivery may explain these findings. Additionally, it was suggested that the change of socio-economical environment, including the lifestyle of women, may have did not agree with the decreasing trends of MBW.

Birth Weight↗
PubMed1994

[Analysis of the seasonal variations in mean birth weight and mean gestational period of 47 prefectures in Japan].

Seasonal variations of the mean gestational period (MGP) and mean birth weight (MBW) are examined by the traditional method of time-series analysis during the period from 1979 to 1983 in Japan. The results of the present study support the existence of a seasonal rhythm of MGP. Generally MGP showed a deep trough in winter and a shallow one in summer to early autumn. This pattern was similar to that of MBW. The two time series showed a statistically significant coincidence in their monthly fluctuations, and a statistically significant correlation was also observed for their amplitude. According to these results, we concluded that the seasonality in MGP plays an important role in creating the seasonality in MBW. However, the seasonality in MGP can not be the only definitive factor that totally regulates the seasonal variations in MBW. The relationship between the two time series is considered to be different among different seasons as well as regions. For example, we observed a decrease of the seasonal index in winter in the same month for both MBW and MGP, but not necessarily in summer. This suggests that the etiology of the decrease in seasonal variations is different between summer and winter.

Birth Weight↗
PubMed1994

Helminth survey of wildcats in Japan.

Two Iriomote cats (Felis iriomotensis) and 2 Tsushima leopard cats (Felis bengalensis euptilura) killed probably by traffic accidents were submitted to the helminthological examination. In Iriomote cats, 8 species of parasites (Spirometra erinacei, Toxocara cati, Molineus springsmithi, Uncinaria maya, Capillaria aerophila, C. felis-cati, larvae of an unidentifiable lung worm and one species of Acanthocephala) were found. In Tsushima leopard cats, 10 species of parasites (Pharyngostomum cordatum, Spirometra erinacei, Toxocara cati, Molineus springsmithi, Arthrostoma hunanensis, Uncinaria felidis, Capillaria felis-cati, larvae of an unidentifiable lung worm, and two species of Acanthocephala) were detected.

Animals↗
PubMed1994

Muscular dystrophy of the diaphragmatic muscles in Holstein-Friesian cows.

Six Holstein-Friesian cows suffering from recurrent rumenal tympany were pathologically investigated. Macroscopical lesions associated with the clinical symptoms were confined to the diaphragmatic muscles which were pale, and stiff on palpation. Histopathological examination revealed various degenerative changes in diaphragmatic muscles as follows: variation in muscle fiber diameter, vacuolar and hyalinized degeneration of muscle fibers, fiber splitting, central core-like structures, sarcoplasmic masses and ring fibers. These characteristic features in the present cases were consistent with dystrophy of the diaphragmatic muscles in Meuse-Rhine-Yssel cattle. From these observations, it is confirmed that muscular dystrophy of the diaphragmatic muscles dose occur in Holstein-Friesian cows, although a genetic mode was not proven.

Animals↗
PubMed1994

Coronary artery ectasia with annuloaortic ectasia.

A 50-year-old Japanese woman with annuloaortic ectasia was found to have total coronary artery ectasia without evident atherosclerosis. The coronary ectasia may have been secondary to or of similar etiology to the annuloaortic ectasia. There was neither stigmata of Marfan's syndrome nor any sign of dissection of the ascending aorta or coronary arteries. Furthermore, the patient was not elderly, and had no hyperlipidemia, diabetes mellitus, or history of smoking. There was a marked blood pressure difference between the arms, and linear calcification was present in the aortic wall. A stenotic lesion was present in the right mid-subclavian artery. Although it is impossible to rule out atherosclerosis as the etiology of these findings, the possibility that they may be a manifestation of Takayasu's arteritis is discussed.

Angiography↗
PubMed1994

Intrafamilial clustering of genotypes of hepatitis C virus RNA.

Hepatitis C virus (HCV)-RNA in the blood was measured by polymerase chain reaction (PCR) in 37 subjects from eight families in which 2 or more persons tested seropositive for antibodies against C100-3 or CP9. HCV-RNA was positive in 17 of 37 subjects. Two or more HCV-RNA-positive subjects were observed in six of the families. Intrafamilial HCV infection was studied by determining the HCV-RNA type (I, II, III or IV) by PCR using type-specific primers. In two families, all of the subjects showed type III infection, and in three other families, all of the subjects showed type II infection, with different types of HCV infections being observed in only one family. The HCV type was uniform in all but one. These findings suggest a possibility of intrafamilial infection between husbands and wives and between members of the same household.

Adolescent↗
PubMed1994

[A study on the visibility of different floor levels--experiments from a stumbling point of view].

Experiments were conducted to examine the visibility of different floor levels from a stumbling point of view. The test subjects were the elderly and the young, and we compared the difference between the two. We investigated eye movement while they were scanning the different floor levels. The results were as follows: 1) The height of different floor levels and illuminance had an influence on the visibility of different floor levels. Especially, the elderly were easily influenced by them. 2) The eye movements in scanning the different floor levels did not relate to the visibility of them, but were related to the personality of the test subjects. Eye movement patterns of the elderly differed from that of the young. The elderly were scanning mainly the lower part. The eye fixation time of the elderly was longer than that of the young. From the results, it was clarified that there were the difference between the elderly and the young. We could show it by the degree of influence. For example, the influence by the change of environmental condition.

Adult↗
PubMed1994

[Clinical study of neoadjuvant intraarterial chemotherapy (I A-MAC) for advanced bladder cancer].

The clinical efficacy of intraarterial neoadjuvant chemotherapy with MTX, ADR and CDDP in 88 patients with advanced bladder cancer (> or = T2 or TCC G3) was evaluated. The intraarterial chemotherapy was performed using Seldinger's method. The three drugs were administered at the same time among 60 patients. In sixteen patients MTX was administered intravenously before intraarterial infusion of ADR and CDDP. In twelve patients, a high dose of CDDP (more than 100 mg/m2) was administered. The mean regression rate was 70%. That of the high-dose CDDP group was rather superior to the other two groups. However, the adverse reaction and duration of recovery were inferior to those of the other two groups. When intraarterial chemotherapy is performed as a neoadjuvant chemotherapy, care must be taken to determine the suitable dose.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

A synthetic model of collagen structure taken from bovine macrophage scavenger receptor.

A putative collagen structure from macrophage scavenger receptors binds to a wide range of ligands. In order to elucidate the ligand's binding mode, this collagen structure was constructed using short peptides. This was accomplished by the reaction of a tri-bromoacetylated branched peptide with a purified unprotected 25-residue peptide, which contained Cys, 4 repeats of triplet, Gly-Pro-Hyp, and 12 residues from the bovine of the N-terminus cross-linked tripeptide show that it forms a collagen structure below 10 degrees C and an extended structure at high temperature with a midpoint of 20 degrees C.

Amino Acid Sequence↗
PubMed1993

Detection of micrometastatic prostate cancer cells in lymph nodes by reverse transcriptase-polymerase chain reaction.

We have developed a highly sensitive method for detecting prostate cancer cells using reverse transcriptase-polymerase chain reaction (RT-PCR) with primers specific for prostate-specific antigen gene. Forty-four lymph nodes obtained from 22 patients with prostate cancers were analyzed by RT-PCR to detect metastatic prostate cancer cells. RT-PCR could detect prostate-specific antigen mRNA in five lymph nodes with histologically and/or immunohistochemically identifiable metastases and in four lymph nodes with negative histological and immunohistochemical analyses for metastases. RT-PCR was a more sensitive method than histology and immunohistochemistry in detecting metastatic prostate cancer cells and could be applied for diagnosing micrometastases of prostate cancer to lymph nodes. This highly sensitive RT-PCR will be a relevant tool to allow a more accurate clinical assessment of lymph node metastases of prostate cancer and to understand lymphatic dissemination of prostate cancer biologically.

Base Sequence↗
PubMed1993

Regulation of apolipoprotein B production and secretion in response to the change of intracellular cholesteryl ester contents in rabbit hepatocytes.

In the present study, we investigated the mechanisms that regulate apolipoprotein B-100 (apoB) secretion in response to the change of intracellular cholesteryl ester contents by adding low density lipoprotein (LDL) and an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase (pravastatin) in rabbit hepatocyte culture system. LDL caused a significant dose-dependent increase in apoB secretion. On the other hand, the addition of pravastatin decreased apoB secretion significantly. LDL caused a dose-dependent increase in cellular cholesteryl ester, while cellular cholesteryl ester was decreased by pravastatin significantly. Therefore, these results indicate that the change of apoB secretion was in parallel with the change of cellular cholesteryl ester contents. Cellular contents of free cholesterol, triglyceride, and phospholipid did not change. To investigate intracellular degradation of apoB prior to secretion, pulse-chase experiments were performed. It was shown that the addition of pravastatin accelerated intracellular degradation of apoB, while LDL slowed the apoB intracellular degradation rate. We also investigated whether the change of cellular cholesteryl ester could affect the apoB mRNA level. Northern blot analysis and solution hybridization RNase protection assay demonstrated that neither LDL nor pravastatin caused a significant change in cellular apoB mRNA level. We conclude that intracellular cholesteryl ester contents play a critical role in apoB secretion, and the intracellular apoB degradation rate could be the main mechanism that regulates apoB secretion in response to the change of intracellular cholesteryl ester level.

Acetates↗
PubMed1993

Selection of an HEL-derived cell line expressing high levels of platelet factor 4.

A platelet factor 4 (PF4)-expressing cell line, HELNeo, was derived from the human erythroleukemia cell line, HEL. This was achieved by stable transfection of HEL cells with a construct containing the rat PF4 promoter driving the gene coding for resistance to neomycin, followed by selection of neomycin-resistant clones. HELNeo cells were all nonadhering and about 5% of the cells had polyploid nuclei (> or = 8N), as compared with 1% in HEL cells. Immunohistochemistry showed that about 90% of the HELNeo cells contained PF4, whereas only approximately 5% of the HEL cells contained PF4. No significant parallel enrichment was observed for other megakaryocytic markers, such as the glycoprotein complex IIb/IIIa, von Willebrand factor, and platelet activation-dependent granule to external membrane glycoprotein (PADGEM), which were present to a similar extent in both HEL and HELNeo lines. The increased expression of PF4 in HELNeo cells was confirmed by transient expression assays and was associated with a fivefold increase in trans-acting factors binding to the PF4 promoter. These cells should be a rich source for purifying trans-acting factors binding to the PF4 gene. Moreover, our study shows how a lineage-specific promoter may be used to generate lineage-specific cell lines from a multilineage hematopoietic cell line.

Base Sequence↗