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Biomedical subjects

Y Ohta

Publications and source records attributed to Y Ohta.

At least 523 records · Page 29Linked to original sources
PubMed1994

Serum levels of soluble CD4 and CD8 in patients with chronic viral hepatitis.

The blood levels of soluble CD8 (sCD8) and soluble CD4 (sCD4) were measured in patients with various liver diseases, and their significance was studied. The levels of sCD8 were significantly higher in patients with chronic active hepatitis (CAH), autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), acute hepatitis (AH), fulminant hepatitis (FH) and liver cirrhosis (LC) as compared with the normal controls (NC), and correlated positively with those of GPT (r = 0.67, p < 0.001). In addition, a comparison of the exacerbation of CAH with remission showed that the sCD8 levels were significantly higher in the former. On the other hand, there was no significant rise in the level of sCD4 in patients with any liver disease, except FH, no definite relationship between sCD4 and sGPT, and no consistant tendency in sCD4 levels between exacerbation and remission. The reason for an insignificant elevation of the sCD4 level is the fact that in hepatitis the CD8-positive cells, which are cytotoxic T cells, are directly involved in hepatocyte damage; therefore the CD8-positive cells are predominantly activated, while the activity of the CD4-positive cells is considered to be lower. Instead of determining the number of CD4-positive cells and CD8-positive cells in the mononuclear cells of peripheral blood, serum sCD4 and sCD8 levels can be measured simply and inexpensively. Thus, these levels may be useful immune markers.

CD4 Antigens↗
PubMed1994

Therapeutic effects of imidapril on cerebral lesions observed by magnetic resonance imaging in malignant stroke-prone spontaneously hypertensive rats.

OBJECTIVE: Magnetic resonance imaging (MRI) was used to investigate the therapeutic effects of imidapril, a newly synthesized angiotensin converting enzyme (ACE) inhibitor, on cerebral stroke lesions. DESIGN: Pretreatment with ACE inhibitors is known to prevent stroke in stroke-prone spontaneously hypertensive rats, prolonging their lifespan. Malignant stroke-prone spontaneously hypertensive rats (M-SHRSP) were treated with imidapril after the onset of stroke. METHODS: M-SHRSP with proved stroke were divided into two groups. One group received 40 mg/kg per day imidapril and the other group was used as a control. For 4 weeks, neurological symptoms were scored daily, and MRI images were taken and scored once a week. RESULTS: In the control group the MRI score for cerebral lesions increased during the experiment, and seven out of eight control rats died within 17 days. In rats treated with imidapril the major finding was that imidapril rapidly ameliorated the damage to the blood-brain barrier and resolved brain oedema within 1 week. At the same time the neurological symptoms observed after stroke disappeared. Furthermore, none of the rats treated with imidapril showed recurrence of stroke, and their survival rate was improved. CONCLUSION: These results suggest that imidapril has therapeutic effects on stroke lesions, as well as prophylactic effects on the recurrence of stroke.

Animals↗
PubMed1994

[99mTc-pertechnetate scintigraphy in three cases with soft tissue tumors].

Three soft tissue tumors were studied with 99mTc-pertechnetate scintigraphy, 67Ga-citrate scintigraphy and MRI. These tumors included schwannoma, neurofibromatosis and malignant fibrous histiocytoma. On 99mTc-pertechnetate scintigram all patients showed more increased accumulation corresponding to the tumor than on 67Ga-citrate scintigram. In conclusion, 99mTc-pertechnetate scintigraphy may be useful in detection of soft tissue tumors.

Adolescent↗
PubMed1994

[A national surveillance study on alcoholic liver disease in Japan (1986-1991)].

National surveillance studies on alcoholic liver disease (ALD) in Japan were performed in 1978 and 1985, by a previous Japanese study group for ALD (Takeuchi group). In the present study, a subsequent nationwide surveillance study was performed from 1986 to 1991 and the results were compared with the previous two studies. In order to clarify the etiological relationships between hepatitis C virus (HCV) infection and ALD, an analysis was also done according to the new diagnostic criteria of ALD which was proposed by this group (Takada group). By the criteria of the Takeuchi group, the incidence of ALD was not significantly different during 1986 to 1991. However, the incidence of hepatocellular carcinoma (HCC) in alcoholic cirrhosis (AL-LC) clearly increased during this period. The analysis including the results of the previous study indicate that incidence of ALD reached a plateau in 1980 and then features of ALD in Japan entered a stable stage. However, HCC in AL-LC continued to show a linear increase from 1976 to 1991. Analysis with the new criteria of the Takada group was done in cases of 1990 and 1991. Approximately 2 out of 3 cases of ALD were caused by alcohol alone, and the remaining cases were caused by a combination of alcohol and HCV. Cases caused only by HCV were very rare. The main etiology in patients with alcoholic hepatitis and fibrosis was alcohol alone and that in chronic hepatitis of heavy drinkers was a combination of alcohol and HCV. In half of the patients with AL-LC, the etiology was alcohol alone and in the other half patients, it was a combination of both factors. In most patients with HCC, the etiology was a combination of alcohol and HCV, indicating that HCV infection may be important for the development of HCC in alcoholics.

Carcinoma, Hepatocellular↗
PubMed1994

Three-dimensional black blood MR angiography of the liver during breath holding. A comparison with two-dimensional time-of-flight MR angiography.

In 2-D time-of-flight MR angiography (2-D TOF MRA) of the liver, artifacts caused by respiratory motion are unavoidable. Therefore, a 3-D black blood MRA of the liver was attempted in 7 healthy volunteers, using a 3-D gradient echo sequence which allows imaging during breath holding. 2-D TOF MRA was performed as well. In all subjects, 3-D MRA allowed visualization of the trunk, 1st-, and 2nd-order branches of the portal vein without interruption. Right 3rd-order branches were visualized without interruption in 6 of 7 subjects (85%). However, with 2-D MRA, the transverse portion of the left main portal vein could not be visualized in any subject, and the periphery of the portal vein was less clear than with 3-D MRA.

Adult↗
PubMed1994

Clinical experience of 123I-IMP scintigraphy in detecting vertebral bone metastases of hepatocellular carcinoma. A comparison with bone scintigraphy with 99mTc-MDP.

Although bone scintigraphy with 99mTc-MDP is a sensitive diagnostic method to detect bone metastasis, it is not specific for malignancy. A radioactive substance which accumulates specifically into metastatic lesions should be of value. 123I-IMP and bone scintigraphy with 99mTc-MDP were consecutively performed in patients with vertebral bone metastases from hepatocellular carcinoma and lumbar spondylosis deformans in a 7-day interval or shorter. The intensity of uptake was compared. Eighteen of the 20 metastatic lesions (90%) were classified as increased uptake areas in 123I-IMP scintigraphy. MDP-scintigraphy disclosed 16 metastatic lesions (80%), 9 as "hot" lesions (56%) and 7 as "cold" lesions (44%). 123I-IMP scintigraphy was negative in all 12 lesions of lumbar spondylosis deformans. Compared to MDP-scintigraphy, 123I-IMP scintigraphy was more sensitive in detecting vertebral bone metastases of hepatocellular carcinoma with smaller rates of false-positive and false-negative findings.

Amphetamines↗
PubMed1994

[Two cases of pulmonary hypertrophic osteoarthropathy associated with primary lung cancer, in which symptoms were rapidly improved by resection of the primary lesions].

Pulmonary hypertrophic osteoarthropathy (PHO) is a syndrome of unknown etiology, presenting with osteitis of the long bones, arthritis, and clubbing of digits, associated with lung cancer or other chronic pulmonary or pleural diseases. Although about 3-10 percent of cases of lung cancer were reported to be associated with PHO in USA or Europe, reports of these cases are relatively rare in Japan. We report two cases of PHO associated with primary lung cancer, in which symptoms were rapidly improved by resection of the primary lesions. Both cases were poorly differentiated adenocarcinoma of the lung (pT2N0M0, Stage I). The bone and joint pain rapidly improved soon after the resection of the primary lesions. The abnormal findings of bone scan and bone X-ray film subsequently improved. In the 2nd case, radionuclide imaging more clearly revealed the presence and extent of subperiosteal activity than radiography. Radionuclide disclosure of PHO was considerably more sensitive than radiography.

Adenocarcinoma↗
PubMed1994

[Manometric study of the biliary sphincter zone: a comparison between the length of phasic activity and the narrow distal segment].

Motor activity of the sphincter of Oddi has been evaluated in 26 patients who underwent ERCP examination. Manometric recordings from the common bile duct and the sphincter of Oddi were performed with a single end-lumen perfused catheter. The number of successive 3 mm spaced black marks, observed during the pull-through from the first appearance of the proximal sphincter activity to that of duodenal pressure, was used to measure the length of the sphincter zone. In 14 of 26 patients, the length of phasic activity zone of the sphincter of Oddi was 9 mm. However, the narrow distal segment of the common bile duct was 15.1 +/- 3.6 mm in length. In same patients, the length of phasic activity zone was shorter than the anatomical one. The mean sphincter of Oddi pressure (SOP) at the distance of 6 mm from the papillary pore (77.8 +/- 22.1 mmHg) was greater than that of 9 mm (58.4 +/- 27.0 mmHg) and 12 mm (51.0 +/- 16.9 mmHg). These results suggest that the location of the orifice of catheter should be taken into consideration when comparing the SOP.

Adult↗
PubMed1993

Membrane topology of bovine adrenocortical cytochrome P-450C21: structural studies by trypsin digestion in vesicle membranes.

Purified adrenocortical microsomal P-450C21 was incorporated into vesicle membranes composed of phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine at a molar ratio of 5:3:1. Trypsinolysis of the incorporated P-450C21 resulted in the formation of 30-, 25-, and 20-kDa fragments. Similar fragment formation was observed by trypsinolysis of bovine adrenocortical microsomes with Western blotting using anti-P-450C21 IgG. In the detergent-solubilized state, trypsin cleaved P-450C21 into very small peptides. Washing of the trypsin-treated vesicles with 500 mM Na2CO3 failed to cause these fragments to separate from membranes. N-Terminal amino acid sequencing of these fragments showed that trypsin cleaved the 267 Arg-268Val and 332Arg-333Val bonds of P-450C21. The time course of fragment formation indicated that trypsin cleaved the 267Arg-268Val bond first to produce 30- and 25-kDa fragments and subsequently the 332Arg-333Val bond in the 25-kDa fragment to produce the 20-kDa fragment. Neither 21-hydroxylase activity, the reduced CO difference spectrum, nor the EPR spectrum of digested P-450C21 differed from those of undigested P-450C21. Heat treatment at 50 degrees C for 20 min did not cause any decrease in activity of digested P-450C21, when the substrate progesterone was present. This high stability toward heat treatment was not observed in the solubilized state. Rotational diffusion experiments on P-450C21 showed that the size of the molecule holding the heme was not changed significantly after digestion. On the basis of these results, P-450C21 is concluded to be deeply embedded in the vesicle membranes.

Adrenal Cortex↗
PubMed1993

Diversification, not use, of the immunoglobulin VH gene repertoire is restricted in DiGeorge syndrome.

Immunoglobulin (Ig) genes were isolated from unamplified conventional as well as polymerase chain reaction-generated cDNA libraries constructed from the peripheral blood cells of a patient with complete DiGeorge syndrome. Comparison of the sequences of 36 heavy chain clones to the recently expanded database of human VH genes permitted identification of the germline VH genes that are expressed in this patient as well as placement of 19 of these genes in a partially resolved 0.8-mb region of the human VH locus. The pattern of VH gene use does not resemble the fetal (early) repertoire. However, as in the fetal repertoire, there are a number of cDNAs derived from germline genes that previously have been identified as autoantibodies. Two D mu sequences also were identified, as was another sequence resulting from a unique recombination event linking JH to an unidentified sequence containing a recombination signal sequence-like heptamer. All of the DiGeorge cDNAs are closely related to germline VH genes, showing little or no evidence of somatic mutation. In contrast, comparably selected IgM VH sequences derived from normal adult and age-matched human libraries, and from a second DiGeorge syndrome patient in whom the degree of thymic dysfunction is much less severe, exhibit considerable evidence of somatic mutation. The absence of somatic mutation is consistent with the atypical development of functional antibody responses associated with complete DiGeorge syndrome and implicates a role for T cells in the generation of diversity within the B cell repertoire.

Antibody Diversity↗
PubMed1993

[Clinical usefulness of 123I-IMP scintigraphy in the diagnosis of bone metastases from hepatocellular carcinoma: comparison with 99mTc-MDP bone scintigraphy].

The diagnostic value of N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) scintigraphy was evaluated in 12 patients with 20 bone metastases from hepatocellular carcinoma, in comparison with 99mTc-methylene diphosphonate (99mTc-MDP) bone scintigraphy. Sixteen lesions (80%) were detected by 123I-IMP scintigraphy, whereas four lesions (two lesions in the rib and two lesions after a radiation of 40 Gy) were missed. Of 16 lesions demonstrated as areas of increased uptake in 123I-IMP scan, only eight (50%) showed an increased pattern of uptake in 99mTc-MDP bone scintigraphy. In conclusion, 123I-IMP is a promising radiopharmaceutical for the detection of bone metastases from hepatocellular carcinoma.

Amphetamines↗
PubMed1993

A synthetic approach to polysialogangliosides containing alpha-sialyl-(2-->8)-sialic acid: total synthesis of ganglioside GD3.

A stereocontrolled, facile total synthesis of ganglioside GD3 is described as an example of a proposed systematic approach to the preparation of gangliosides containing an alpha-sialyl-(2-->8)-sialic acid unit alpha-glycosidically linked to O-3 of a D-galactose residue in their oligosaccharide chains. Glycosylation of 2-(trimethylsilyl)ethyl 6-O-benzoyl-, 3-O-benzoyl-, or 3-O-benzyl-beta-D-galactopyrano-sides, or 2-(trimethylsilyl)ethyl 2,3,6,2',6'-penta-O-benzyl-beta-lactoside (7), with methyl [phenyl 5- acetamido-8-O-(5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D- glycero-alpha-D-galacto-2-nonulopyranosylono-1',9 lactone)- 4,7-di-O-acetyl-3,5-dideoxy-2-thio-D-glycero-D-galacto-2-nonulopyrano sid] onate (3), using N-iodosuccinimide-trifluoromethanesulfonic acid as a promoter, gave the corresponding alpha glycosides 8 (32%), 13 (33%), 14 (48%), and 17 (31%), respectively. The glycosyl donor 3 was prepared from O-(5-acetamido-3,5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosy lonic acid)-(2-->8)-5-acetamido-3,5- dideoxy-D-glycero-D-galacto-2-nonulopyranosonic acid by treatment with Amberlite IR-120 (H+) in methanol, O-acetylation, and subsequent replacement of the anomeric acetoxy group with phenylthio. Compound 8 was converted into the methyl beta-thioglycoside via O-benzoylation, replacement of the 2-(trimethylsilyl)ethyl group by acetyl, and introduction of the methylthio group by reaction with methylthiotrimethylsilane. Compound 17 was converted, via O-acetylation, selective removal of the 2-(trimethylsilyl)ethyl group, and reaction with trichloroacetonitrile, into the alpha-trichloroacetimidate, which was coupled with (2S,3R,4E)-2-azido-3-O-benzoyl-4-octadecene-1,3-diol to give the beta-glycoside. This glycoside was easily transformed, via selective reduction of the azido group, condensation with octadecanoic acid, O-deacylation, and hydrolysis of the methyl ester and lactone functions, into ganglioside GD3.

Carbohydrate Sequence↗
PubMed1993

VH gene organization in a relict species, the coelacanth Latimeria chalumnae: evolutionary implications.

The living coelacanth Latimeria chalumnae is a relict species whose higher-level phylogenetic relationships have not been resolved clearly by traditional systematic approaches. Previous studies show that major differences in immunoglobulin gene structure and organization typify different phylogenetic lineages. To date, mammalian-, avian-, and elasmobranch-type gene organizations have been identified in representatives of these different phylads. A fourth form or organization is found in Latimeria, which possesses immunoglobulin heavy-chain variable region (VH) elements separated by approximately 190 nucleotides from diversity (D) elements. Adjacency of VH and D elements is characteristic of the elasmobranch "clustered" arrangement, although many other features of coelacanth VH gene organization and structure are more similar to those of bony fishes and tetrapods. These observations strongly support a phylogenetic hypothesis in which Latimeria occupies a sister-group relationship with teleosts and tetrapods.

Amino Acid Sequence↗
PubMed1993

[Experimental study with radiofrequency-induced thermal arterial occlusion].

A preliminary experiment on arterial occlusion using radiofrequency energy was performed. A surgitron FFPF was used as a radiofrequency power generator, and a Tracker 18 catheter was used as a probe insulator. A 10 mm length of the guide wire protruding from the tip of catheter was used as the radiofrequency probe. To examine the safety of this procedure within the vessels, the following experiments were performed. A 2.5 mm diameter dimple at the surface of a sausage was filled with human blood. We inserted various lengths of non-insulated guide wire into the dimple and supplied radiofrequency power. We then measured the time until air bubbles appeared in the dimple. With a 10 mm length of non-insulated guide wire, this took over 30 sec. Animal experiments were carried out in 17 canine arteries. The diameter of these arteries ranged from 1.3 to 3.7 mm. Before the procedure, angiograms were taken using a 5 F catheter from the right femoral artery. A tracker 18 catheter and guide wire were inserted to the target position co-axially. The guide wire was attached to the radiofrequency generator. The tip of the guide wire functioned as the convergence point of an electrically conducting induced current. Treatment was performed by supplying radiofrequency power of various durations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Alcohol dehydrogenase (ADH2) from a mutant strain of Candida guilliermondii A80-03: purification and characterization.

Alcohol dehydrogenase ADH2 was purified twice from Candida guilliermondii strain A80-03, by ion exchange column chromatography on DEAE-Toyopearl 650M. The enzyme was a dimer of M(r) 98,500. ADH2 had a broad substrate specificity, oxidizing secondary alcohols as well as primary alcohols. The enzyme was sensitive to several inhibitors, such as metal chelators and thiol reagents. Kinetic studies suggested that ADH2 oxidized ethanol by an iso ordered sequential mechanism.

Alcohol Dehydrogenase↗
PubMed1993

[A study of transsplenic CO2 gas enhanced portal angioechography].

Transsplenic CO2 gas enhanced portal angioechography was examined. The spleen of three dogs was punctured by 23 gauge needle with two side holes. From 5 ml to 20 ml of CO2 gas was injected into the splenic vein via the splenic parenchyma, and elevation of echo level of the liver was observed. Hematoma was not seen at the site of puncture. Good image was obtained in the case of 5 ml CO2 injection. In one dog with pseudotumor in the liver, the hyperechoic tumor changed into negative enhanced nodule after CO2 gas enhancement. Transsplenic CO2 gas enhanced portal angioechography is thought to be useful to evaluate hepatic tumors.

Animals↗