Biomedical subjects

Y Tada

Publications and source records attributed to Y Tada.

At least 181 records · Page 10Linked to original sources

PubMed1997

Evolutionary analysis of influenza C virus M genes.

The previous study of the 25 hemagglutinin-esterase (HE) glycoprotein genes of influenza C viruses identified four discrete lineages represented by C/Yamagata/26/81, C/Aichi/1/81, C/Aomori/74 and C/Mississippi/80, respectively. Here we compared the M gene sequence among the 24 viruses isolated between 1964 and 1991. A phylogenetic analysis showed that these genes have evolved into three distinct lineages. Lineage I included most of viruses with the HE genes of C/Yamagata/26/81-related lineage. The predominant members of lineage II were viruses having the HE genes of either C/Aichi/1/81- or C/Mississippi/80-related lineage. Lineage III contained only C/Aomori/74. Phylogenetic positions of several strains (C/Yamagata/64, C/Kanagawa/1/76, C/Miyagi/77 and C/Nara/1/85) were different between the M and HE gene trees, suggesting that they are reassortants. Furthermore, phylogenetic relationships between C/Mississippi/80-like and C/Aichi/1/81-like viruses were much closer for the M gene than the HE gene, raising the possibility that these two virus groups are genetically related by a reassortment event. Nucleotide changes in the M genes occurred at about 7% positions with a uniform distribution throughout the molecules. However, the predicted amino acid sequence of the matrix protein (M1) was conserved almost completely among the isolates analyzed. The amino acid sequence of the second protein (CM2) encoded by M gene was also highly conserved, but was more divergent than the M1 protein sequence, suggesting that the two M gene products are evolving differently in response to selective pressures or structural and functional constraints.

Amino Acid Sequence↗

PubMed1997

M3 muscarinic receptor mediates regulation of protein secretion in rabbit lacrimal gland.

PURPOSE: To identify which muscarinic receptor subtypes mediate protein secretion in isolated rabbit lacrimal glands. To compare protein secretory profiles in vitro with those in rabbit tears. METHODS: Rabbit lacrimal gland slices were incubated with carbachol in the presence and absence of different muscarinic antagonists. Protein secretion into the incubation medium was characterized with a Bio-Rad protein assay dye reagent in conjunction with Laemmli's method of SDS-PAGE. The medium protein profile was compared to that in tear samples. RESULTS: Dose dependent increases in protein secretion were elicited by carbachol between 10(-7) and 10(-4) M. During the first 20 min period, a maximal increase of 64% above the basal level was seen at the highest concentration. With 10(-4) M carbachol, the response was transient because after 100 min it decreased to its basal level. The increases in protein secretion caused by 10(-4) M carbachol were completely suppressed in the presence of 10(-5) M atropine. On the other hand, the relatively selective M1 antagonist, pirenzepine, at concentrations from 10(-6) M to 10(-4) M, had no effect on either the basal levels or the stimulatory effects of carbachol. Similarly, the relatively selective M2 antagonist, gallamine, at concentrations from 10(-6) M to 10(-4) M, had no effect on either of these levels. In contrast, the relatively selective M3 antagonist, 4-DAMP, at concentrations from 10(-6) M to 10(-4) M, progressively suppressed the stimulated level of protein secretion elicited by 10(-4) M carbachol without affecting the basal level. The protein profiles found in the tears and in the incubation medium were similar to one another. CONCLUSION: In vitro rabbit lacrimal gland protein secretion is comparable to that in vivo. Cholinergic-mediated control of rabbit lacrimal gland protein secretion occurs through stimulation of the M3 muscarinic receptor subtype.

Animals↗

PubMed1997

[Evaluation of the assay technique for detection of anti-chlamydial IgA and IgG antibodies in PID patients].

The purpose of this study is to evaluate the usefulness and limitation of Rapizyme CHLAMYDIA, enzyme-linked immunosorbent assay (ELISA) for qualitative detection of anti-chlamydial IgG and IgA antibodies, in the serum of 92 PID patients and 73 pregnant women, compared with those of Sero IPALISA CHLAMYDIA. The result of Rapizyme analysis was obtained within 10 minutes with no special devices. Overall agreements of Rapizyme and Sero IPALISA were 90.9% (IgG) and 90.3% (IgA) in the total patients, 88.0% (IgG) and 85.9% (IgA) in PID patients, and 94.5% (IgG) and 95.9% (IgA) in pregnant women. The positive rate of Chlamydia in PID was 17.4% (16/92). Positive agreement of Rapizyme in Chlamydia positive PID and pregnant women was 100% in both IgG and IgA, and negative agreement was also 100%. Positive agreement in Chlamydia negative PID was 100% in both IgG and IgA, and negative agreement was 90.0% (IgG) and 83.3% (IgA). The results of Rapizyme were in close agreement with those of Sero IPALISA. COI (cut off index) of Sero IPALISA clearly decreased in 3 of 6 PID patients during a 3 to 6 months period after chemotherapy, but those changes were not observed in Rapizyme. These results suggest that Rapizyme CHLAMYDIA is a useful diagnostic kit for Chlamydial PID of outpatients.

Antibodies, Bacterial↗

PubMed1997

Perforin-secreting killer cell infiltration in the aortic tissue of patients with atherosclerotic aortic aneurysm.

Cell-mediated immunity has been implicated in the pathogenesis of vascular cell injury in patients with atherosclerotic aortic aneurysms. To clarify the immunologic mechanisms involved, we examined the expression of a cytolytic factor, perforin, in infiltrating cells from aortic tissue samples taken from 6 patients with atherosclerotic aortic aneurysms. Immunohistochemical studies showed that the infiltrating cells consisted mainly of macrophages, natural killer (NK) cells, cytotoxic T lymphocytes (CTLs), and T helper cells, and that perforin was expressed in NK cells and CTLs. Immunoelectron microscopic studies demonstrated that the infiltrating cells released massive amounts of perforin directly on to the surface of arterial vascular cells. These findings provide the first direct evidence that some of the infiltrating cells in the aortic tissue consist of killer cells, and strongly suggest that these killer cells, especially NK cells and CTLs, may play a critical role in the vascular cell injury caused by atherosclerotic aortic aneurysm by releasing perforin.

Aged↗

PubMed1997

[A case of Wegener's granulomatosis associated with refractory bowel granulomatous ulcers].

We describe a 58-year-old woman who developed Wegener's granulomatosis (WG) complicated by a perforation of the transverse colon caused by necrotizing granulomatous vasculitis. In addition, her colon lesion continued in spite of high dose corticosteroid and cyclophosphamide therapy. She was admitted to our hospital because of her severe tonsillitis in Dec., 1994. She was diagnosed as having WG because she had oral ulcer, antibiotics-resistant lung infiltration, renal dysfunction and positive C-ANCA. Just after we started high dose steroid therapy, the transverse colon was perforated because of vasculitis, and she underwent emergency operation. Many vasculitic lesions were found in the small intestine, colon, and mesenterium. The disease was improved by corticosteroid and cyclophosphamide therapy except for a sustained ulcer with necrotizing vasculitis in the sigmoid colon region even 1 year after the operation. Although WG rarely complicates digestive tract lesions as initial manifestations, they reach 12% of the causes of death of WG in Japan. Therefore, we should take care of digestive tract lesions when we follow-up patients with WG.

Antibodies, Antineutrophil Cytoplasmic↗

PubMed1997

[Surgical management of extracranial internal carotid artery aneurysms].

Aneurysms of the extracranial internal carotid artery are rare but may present as a mass, with ischemic symptoms, or with fatal hemorrhage. We operated on aneurysms in four patients, two males and two females, whose ages ranged from 47 to 57 years. While a lot of etiological factors for the aneurysms have been known to include trauma, vascular dysplasia, infection or surgery using patch graft for carotid endarterectomy, three aneurysms in our series were atherosclerotic and one was spontaneously dissecting. One patient had focal neurological deficit due to embolism, two presented with a growing cervical mass, and one was symptom-free. The aneurysm was located proximal below the angle of the mandible in three patients and was distal above the angle in one. All patients were found able to tolerate test occlusion of the internal carotid before surgery. The aneurysm was trapped in one case (case 1) and was encased by vascular prosthesis in another (case 4). In the other two cases, arterial reconstruction after aneurysmal resection was carried out. In one case out of the two, the aneurysm was located at the level of 2nd cervical vertebral body (case 2). Vertical mandibular osteotomy was performed posteriorly to the exit of the inferior alveolar nerve from the bone, which gave a good view of the upper third of the internal carotid artery and facilitated primary end-to-end anastomosis. In the other case in which there was a dilated distal carotid artery and multiple aneurysms at the basilar and bilateral vertebral arteries (case 3), an extracranial-intracranial (EC-IC) saphenous vein bypass was inserted so as not to increase the hemodynamic stress in the posterior circulation. Except for a transient lower cranial nerve palsy in one case (case 2), there were no incidences of morbidity or death. Magnetic resonance angiography (MRA), Doppler ultrasonography or three-dimensional CT angiography (3-D-CT-A) was found useful in evaluating the change of aneurysmal size. It is essential in surgery for an internal carotid artery aneurysm to choose an appropriate approach characterized by its size and location. It may be important in cases with associated vascular lesions to estimate the potential hemodynamic change that might be induced by aneurysmal surgery.

Aneurysm↗

PubMed1997

[Immunomodulatory effect of daily low-dose cisplatin treatment].

Immunomodulatory effects of daily low-dose cisplatin treatment were investigated on compromised patients with advanced or recurrent gastrointestinal cancer. One case of esophageal cancer, 7 of gastric cancer, 2 of colorectal cancer, 1 of carcinomatous peritonitis from unknown origin, and 1 of hepatocellular carcinoma, were treated by daily low-dose cisplatin combined with 5-FU or tegafur, and their ECOG Performance Status Score (PS), number of lymphocytes, and CD3 zeta chain expression of peripheral blood lymphocytes were studied to compare with the effects of treatment. Seven patients with esophageal cancer and gastric cancer showed a partial response and their PS was improved, and the number of lymphocytes and CD3 zeta chain expression of lymphocytes was increased. However, in two patients with progressive disease, a decreased number of lymphocytes and less expression of CD3 zeta chain were seen.

Adjuvants, Immunologic↗

PubMed1997

Remitting seronegative symmetrical synovitis with pitting edema associated with gastric carcinoma.

We report a case of remitting seronegative symmetrical synovitis with pitting edema (RS3PE syndrome) associated with gastric carcinoma in an 80-year-old woman who developed polyarthritis with marked pitting edema of the dorsa of both hands and feet 7 days after fiberscopic examination of the stomach. A mass lesion was identified and histology of the biopsy specimen revealed gastric carcinoma. Polyarthritis and edema were partially relieved by an intraarticular injection of corticosteroid. Shortly after resection of the gastric carcinoma, her symptoms and signs disappeared. She has been free of symptoms for 3 yrs without medication.

Adenocarcinoma↗

PubMed1997

[Assessment of left ventricular systolic function derived from ECG-gated myocardial SPECT with 99mTc-tetrofosmin: automatic determination of LV epi- and endocardial surface].

Non-invasive assessment of ischemic heart disease requires information of both LV function and myocardial perfusion. Recently, ECG-gated myocardial SPECT with technetium-labeled radiopharma-ceuticals can provide both of them. Gated myocardial SPECT were performed in thirty-three patients with cardiac disease using a two-headed rotating gamma camera system (ADAC; VERTEX), 30-60 minutes after resting injection of 555-740 MBq of 99mTc-Tetrofosmin. Then, the SPECT data were used to determine the LV epi- and endocardial surface, and LV volume for measurement of LVEF was calculated automatically. This entire computational process required only 210 seconds per 16 frame study. Interobserver agreement of EF values obtained from gated SPECT was excellent (r = 0.996, n = 10, p < 0.01). LVEFs obtained from gated SPECT showed good correlation to those calculated from radionuclide ventriculography (MUGA) (r = 0.91, p < 0.01). In conclusion, this automatic method using gated myocardial SPECT data was considered to be useful for assessment of LV function with reproducibility.

Aged↗

PubMed1997

[Pathological and immunohistochemical analysis of giant cells of pancreas].

Multinucleated giant cells in the pancreas (five giant cell carcinomas, a mucinous cystadenocarcinoma attended with many osteoclast-like giant cells, 42 invasive ductal carcinomas and 29 chronic pancreatitises) were examined. Three types of multinucleated giant cell were identified: epithelial type, coexpressive type, mesenchymal type. Epithelial type expressed epithelial markers, such as keratin and EMA in 23 ductal carcinomas. Coexpressive type expressed both epithelial markers and mesenchymal marker vimentin was in four ductal carcinomas. Mesenchymal type expressed mesenchymal markers, vimentin and CD68 in four osteoclastoid type giant cell carcinomas, the mucinous cystadenocarcinoma, six ductal carcinomas and ten chronic pancreatitises. Epithelial and coexpressive type were considered to be epithelial neoplastic origin, those had bizarre appearance and transitional area from definite adenocarcinoma area. Vimentin expression is associated with sarcomatous proliferation. Mesenchymal type was considered to be nonneoplastic and a certain type of macrophage polykaryons.

Adult↗

PubMed1997

Localised thrombus in the distal aortic arch: its aetiology analysed by three-dimensional mould model of the thoracic aorta.

Isolated thrombus of the thoracic aorta without aneurysmal change or dissection is a relatively rare event. A case presenting with aortic thrombus and successive distal embolism is reported herein and the aetiology of the thrombus of the distal aortic arch is analysed by a three dimensional aortic model. A 61-year-old man suffered acute ischaemia in his right leg on January 26, 1994. Enhanced computed tomography (CT) showed a localized thrombus in the distal aortic arch expanding towards the descending aorta, and partial infarction of the left kidney and the spleen. Angiography demonstrated abrupt occlusion of the right superficial femoral artery. Immediate anticoagulation with heparin and coumadin was administered, and the thrombus in the aorta disappeared following 1 month of this medical treatment, leaving the renal and splenic infarction unchanged. The unresolved occlusion of the superficial femoral artery and the popliteal artery was treated with a bypass from the right superficial femoral artery to the peroneal artery using a reversed saphenous vein graft. The mould model of the thoracic aorta was reconstructed from CT, and the thrombus was found to be at the most distal and medial site of the lesser curvature of the aortic arch. This specific location is referred mostly as the site for thrombus formation in the literature. The case is reported briefly and the risk of this specific region of the thoracic aorta for thrombus formation is discussed using this mold model.

Angiography↗

PubMed1997

[Modification of the surgical strategy based on intraoperative echographic findings of atherosclerotic ascending aorta].

To prevent the atheroembolic complications such as brain infarction due to the manipulation of atherosclerotic ascending aorta during cardiac surgery, the ascending aorta of 55 patients including 6 emergencies (mean age: 67.7 +/- 6.9 years, valvular disease: n = 12, ischemic heart disease only or combined with valvular disease: n = 43) were evaluated with intraoperative echography as a routine, to enable a proper placement of the cannulae, clamp etc. Irregular elevated lesions into the aortic lumen from the intima were identified in 7 patients (13%, mean age: 71.0 +/- 6.9 years) of ischemic heart disease, which included 2 emergent cases. Arch cannulation was employed in 3 patients with wide-spread lesions on the posterior wall and femoral cannulation was done in 1 patient with wide-spread lesions on the anterior wall. Two of these patients received CABG with in situ arterial conduits under ventricular fibrillation, and the other 2 patients received CABG with aortic cross clamping at the lesion-free site during proximal anastomosis of vein grafts (single clamp technique). Two patients with localized lesion were done CABG with partial aortic clamping and one of them had cerebral infarction during the operation. We recognized that manipulation of the ascending aorta has to be done with a meticulous care and well away from the diseased site. In another patient with localized lesion, the arch cannulation and the single clamp technique were used 2 cm away from that lesion. The brain infarcted patient completely recovered without any sequelae and the others also had no atheroembolic complications. Although calcified lesions on CT were correlated with atheromatous lesions on echogram (p = 0.004), these atheromatous plaques were not detected by enhanced CT, except in only one patient. For screening of the atherosclerosis of ascending aorta, the CT examination was not so effective and the intraoperative echography was the most sensitive and could be easily accomplished. In conclusion, in order to prevent the atheroembolism that might occur due to the improper manipulation of the diseased ascending aorta during usual procedures, surgical strategies have to be modified according to the position, extent and quality of the atherosclerotic lesions, diagnosed by intraoperative echoscanning of the aorta.

Aged↗

PubMed1996

Reduction of 14-16 kDa allergenic proteins in transgenic rice plants by antisense gene.

An antisense gene strategy was applied to suppress the 14-16 kDa allergen gene expression in maturing rice seeds. Gene constructs producing antisense RNAs of the 16 kDa allergen under the control of some rice seed-specific promoters were introduced into rice by electroporation. Immunoblot and RNA blot analyses of the seeds from the transgenic rice plants using the allergen-specific monoclonal antibody and a sequence-specific antisense RNA probe demonstrated that the 14-16 kDa allergen proteins and their transcripts of the seeds from several transgenic lines were present in much lower in amounts than those of the seeds from parental wild-type rice. The high levels of reduction observed were stably inherited in at least three generations.

Allergens↗

PubMed1996

Collagen-induced arthritis in CD4- or CD8-deficient mice: CD8+ T cells play a role in initiation and regulate recovery phase of collagen-induced arthritis.

Collagen-induced arthritis (CIA) is an experimental autoimmune disease induced by immunization with collagen type II (CII). We studied CIA in CD4- or CD8-deficient DBA/1 mice to further define the roles of CD4+ and CD8+ T cells in the disease. CD4-deficient mice developed severe arthritis, and no differences in incidence, clinical course, and severity were observed between CD4 -/- and CD4 +/- mice. Proliferative responses of lymph node T cells to CII was, however, reduced in CD4 -/- mice, and inflamed joints revealed relative accumulation of CD4-CD8-TCR(alpha)(beta)+ cells. A CII-specific T cell line generated from CD4-deficient mice responded to CII in a MHC-restricted fashion and had a CD4-CD8-TCR(alpha)(beta)+ phenotype. Disease incidence in CD8 -/- mice was significantly decreased compared with CD8 +/- mice, even though the severity of arthritis in arthritic mice was not different. These results suggests a role for CD8+ T cells in initiating CIA. Interestingly, CD8-deficient mice were more susceptible to a second induction of arthritis after remission of initial disease, pointing towards an immunoregulatory role for CD8+ T cells. CD8-deficient mice did not, however, show any defect in oral tolerance induction using CII. Taken together, our findings demonstrate that CD4-CD8-TCR(alpha)(beta) cells can trigger systemic arthritis in CD4-deficient mice and that CD8+ T cells can play dual and opposing roles, important both in initiation of CIA and in providing resistance to reinduction of CIA after recovery from initial disease.

Animals↗

PubMed1996

Restricted usage of T-cell receptor Valpha-Vbeta genes in infiltrating cells in aortic tissue of patients with Takayasu's arteritis.

BACKGROUND: Infiltration by perforin-secreting killer lymphocytes, such as T cells and natural killer cells, has been shown to be involved in the pathogenesis of vascular cell damage in Takayasu's arteritis. METHODS AND RESULTS: To investigate the immunological mechanisms involved, especially the nature of T-cell infiltration in Takayasu's arteritis as well as atherosclerosis, we analyzed the expression of T-cell receptor (TCR) Valpha and Vbeta genes in infiltrating cells in the aortic tissue of patients with Takayasu's arteritis and the atherosclerotic aortic aneurysm by polymerase chain reaction (PCR). We also analyzed the expression of cytokine genes by PCR. We found that the repertoires of TCR Valpha as well as Vbeta gene transcripts in Takayasu's arteritis were restricted. The infiltrating cells expressing Valpha2, Valpha16, Valpha17, Vbeta7, and Vbeta13.1 were found in 3 of 4 patients. In contrast, TCR Valpha-Vbeta repertoires in atherosclerotic aortic aneurysm were polyclonal. There was no significant difference in the pattern of cytokine gene expression between the two diseases. CONCLUSIONS: The restricted usage of TCR Valpha as well as Vbeta genes by infiltrating T cells in Takayasu's arteritis may indicate that a specific antigen in the aortic tissue was targeted. Our findings provide the evidence that distinct immunological mechanisms are involved in the pathogenesis of Takayasu's arteritis and atherosclerotic aortic aneurysm.

Aged↗

PubMed1996

CD34-deficient mice have reduced eosinophil accumulation after allergen exposure and show a novel crossreactive 90-kD protein.

CD34 is expressed on the surface of hematopoietic stem/progenitor cells, stromal cells, and on the surface of high-endothelial venules (HEV). CD34 binds L-selectin, an adhesion molecule important for leukocyte rolling on venules and lymphocyte homing to peripheral lymph nodes (PLN). We generated CD34-deficient mutant animals through the use of homologous recombination. Wild-type and mutant animals showed no differences in lymphocyte binding to PLN HEV, in leukocyte rolling on venules or homing to PLN, in neutrophil extravasation into peritoneum in response to inflammatory stimulus, nor in delayed type hypersensitivity. Anti-L-selectin monoclonal antibody (MEL-14) also inhibited these immune responses similarly in both CD34-deficient and wild-type mice. However, eosinophil accumulation in the lung after inhalation of a model allergen, ovalbumin, is several-fold lower in mutant mice. We found no abnormalities in hematopoiesis in adult mice and interactions between mutant progenitor cells and a stromal cell line in vitro were normal. No differences existed in the recovery of progenitor cells after 5-fluorouracil treatment, nor in the mobilization of progenitor cells after granulocyte colony-stimulating factor treatment compared with wild-type animals. Surprisingly, although CD34 was not expressed in these mice, a portion of its 90-kD band crossreactive with MECA79 remained after Western blot. Thus, we have identified an additional molecule(s) that might be involved in leukocyte trafficking. These results indicate that CD34 plays an important role in eosinophil trafficking into the lung.

Allergens↗

PubMed1996

Use of a nondissection method in lower extremity revascularization: a report on our 12-year experience of autogenous vein bypass surgery.

We report herein on our 12-year experience of performing autogenous vein grafting in the lower extremity using a nondissection method. This method involves limiting preparation for the distal anastomosis to exposure of the anterior surface of the vascular sheath, and substituting an Esmarch's rubber bandage or a pneumatic tourniquet for vascular clamps. A series of 86 consecutive patients who received 101 autogenous vein grafts employing this method were retrospectively analyzed. The causes of arterial occlusion were atherosclerosis in 55 patients, Buerger's disease in 23, and other causes in 9. There was one operative death, and 12 late deaths were recorded within a follow-up period extending to 12 years. Of four early occlusions and two stenoses, three were successfully revised within 30 days of surgery. A total of 11 revision operations were required for 10 grafts during the follow-up period, and late graft closure occurred in 9 bypasses. The primary, primary revised, and secondary patency rates at 5 years for the entire series (n = 101) were 65%, 85%, and 86%, respectively, with 42 bypasses to the tibial or peroneal artery having 84% primary revised and 86% secondary patency rates. These findings led us to conclude that minimization of the surgical injury at the distal anastomosis contributed to the long-term patency of the distal bypass.

Adult↗

PubMed1996

Effects of high-density lipoproteins on intracellular pH and proliferation of human vascular endothelial cells.

We investigated the effects of high-density lipoprotein (HDL) on the intracellular pH ([pH]i), and on the proliferation of human vascular endothelial cells (HUVEC), as well as on their production of prostacyclin (PGI2). The [pH]i was slightly acidified when extracellular Ca2+ was chelated with EGTA. Pretreatment of HUVEC with amiloride, the Na+/H+ exchange inhibitor, caused the [pH]i to become strongly acidic. The addition of HDL produced a biphasic shift in [pH]i, with a brief initial acidification followed by a rapid alkaline shift. The initial decrease in [pH]i was abolished in the cells pretreated with EGTA, and subsequent alkalinization was inhibited. The alkalinization of [pH]i disappeared in the cells pretreated with amiloride. These results suggest that [pH]i depends mainly on Na+/H+ exchange and partially on the extracellular Ca2+ of the HUVEC either in the resting unstimulated state or during HDL stimulation. In contrast, the addition of LDL produced an acidification of [pH]i, which was increased by LDL in the Ca(2+)-free condition. In the cells pretreated with amiloride, [pH]i was not further acidified by LDL. As a result, HDL promoted the proliferation of cells, an action that was inhibited by pretreatment with EGTA. However LDL inhibited cell proliferation, an action unaffected by EGTA pretreatment. The addition of HDL also enhanced the generation of prostacyclin in endothelial cells, the enhancement of PGI2 generation resulted from an increase in the release of Ca2+ from storage sites, due not only to an increased production of inositol 1,4,5-trisphosphate (IP3), but also to the alkalinization of [pH]i. These effects may be involved in the mechanism of HDL's anti-atherosclerotic action.

Amiloride↗