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Biomedical subjects

T Matsuda

Publications and source records attributed to T Matsuda.

At least 937 records · Page 52Linked to original sources
PubMed1992

Role of endothelin in disseminated intravascular coagulation.

We examined the changes in plasma levels of endothelin-1 (ET-1), a potent vasoconstrictor peptide, in 47 cases of disseminated intravascular coagulation (DIC) to investigate the role of ET-1 in DIC and its relation to multiple organ failure (MOF). A significant elevation of plasma levels of ET-1 was observed in some cases of DIC, especially in patients with sepsis, blastic crisis of chronic myelogenous leukemia, and cancer. However, no such significant elevation was observed in patients with acute promyelocytic leukemia (APL), acute leukemias except for APL, or non-Hodgkin lymphoma. Plasma levels of ET-1 were higher in patients with DIC with MOF than in those without MOF. Although the levels of ET-1 were decreased or remained low with clinical improvement in most DIC patients, the levels were further increased or remained high in patients who showed no improvement in DIC. It is suggested that ET-1 must play an important role in further progression of MOF with the vasoconstriction and microcirculatory disorders.

Disseminated Intravascular Coagulation↗
PubMed1992

Decreased response to epidermal growth factor during cellular senescence in cultured human microvascular endothelial cells.

We have previously demonstrated that epidermal growth factor (EGF) induces cell migration, tissue-type plasminogen activator synthesis, as well as tubular formation in microvascular endothelial cells from human omental tissue. In this study, we compared the responsiveness to EGF of late passaged (senescent) human omental microvascular endothelial (HOME) cells with that of early passaged (young) HOME cells. We have employed HOME cells derived from surgically resected omental samples from 14 patients. EGF-stimulated cell migration significantly more in the young cells than in the senescent cells during serial cultivation (aging) in vitro. Scatchard analysis demonstrated that the number for both high and low affinity receptors for EGF in HOME cells was decreased dramatically during serial cultivation. The expression of EGF receptor mRNA was also decreased in the senescent HOME cells. Treatment of HOME cells with EGF significantly increased cellular mRNA levels of tissue-type plasminogen activator, and two protooncogenes, c-fos and c-myc, in young HOME cells, but not in senescent HOME cells. Thus HOME cells aged in vitro show a decreased responsiveness to EGF, resulting in decreased migration of human endothelial cells. The serial cultivation of human endothelial cells in vitro may downregulate EGF receptor and decrease responsiveness to exogenous EGF, a potent angiogenic factor.

Blotting, Northern↗
PubMed1992

Slice thickness reduction by partial overlapping presaturation.

We present a new approach to slice thickness reduction that does not require strengthening the selection gradient or increasing the RF pulse duration. The basis of the approach is to employ a thick slice and suppress a portion of its width, thereby forming a thin slice. Two distinct implementations of the technique are introduced and demonstrated by imaging slice profiles in a phantom and generating images of a volunteer's knee.

Humans↗
PubMed1992

Spin-echo M-mode NMR imaging.

A nuclear magnetic resonance (NMR) imaging and display method for the observation of the continuous motion of objects is presented. By modifying a line scan technique, the spin-density distribution along a line is displayed in succession. Although spatial information is limited to only one dimension, the motion of the object is recorded at intervals of 55 ms by using a commercially available NMR imaging system. In a phantom study, this method yielded accurate velocity measurements along a single axis. When the method was applied to the human chest, an image analogous to that of M-mode echocardiography was obtained. This method, which can be called spin-echo M-mode NMR imaging, approaches the functional analysis of cardiac wall motion in regions where echocardiography is not possible. The effects of respiratory motion on the left ventricular wall were recorded in addition to its intrinsic contractile motion in an image obtained along a line parallel to the cranio-caudal axis of the body. The advantages of this method to assess cardiac wall motion in a patient with an arrhythmia were also demonstrated.

Atrial Fibrillation↗
PubMed1992

Protothecosis: a report of two cases in Japan and a review of the literature.

Protothecosis is an emerging opportunistic infection caused by species belonging to the genus Prototheca. Two Japanese cases of protothecosis are documented with a critical review of the literature. A current perspective concerning the microbiology and disease entity of protothecosis is described in detail.

Adolescent↗
PubMed1992

Glomerular tuft ballooning in mitomycin-C-induced renal impairment.

Severe ballooning of the glomerular tufts was observed in a 65-year-old man who was treated with mitomycin C (MMC) and had typical MMC-induced renal lesions. He developed renal failure and severe anaemia 6 months after initiation of chemotherapy. Ballooned tufts were caused by enormous expansion of the sub-endothelial space simultaneously associated with mesangiolysis. Glomerular cysts, described in a variety of disorders including thrombotic microangiopathy and diabetes mellitus, are derived from cystically dilated and united capillary luminae secondary to mesangiolysis. The morphogenesis of this unusual lesion when induced by MMC differs from that of the glomerular cysts previously reported.

Aged↗
PubMed1992

Tachyphylaxis to capsaicin-induced cough and its reversal by indomethacin, in patients with the sinobronchial syndrome.

Cough reflex testing with capsaicin has been used to study the pathophysiology of the cough reflex and the antitussive effects of various drugs. Although the reproducibility of capsaicin-induced cough has been well established in normal subjects, it is not known if prior challenge with capsaicin reduces the subsequent cough response to inhaled capsaicin in patients with the sinobronchial syndrome, a condition characterized by chronic upper and lower airway inflammation. Measurement of the capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was repeated four times at intervals of 15, 30 and 60 min in eleven patients with the SBS and ten normal subjects. The cough thresholds at 15, 30 and 60 min were greater than the initial value in patients with the SBS but not in normal subjects. In addition, we examined the effect of 4 days treatment with indomethacin (100 mg/day) on the cough thresholds measured twice at an interval of 15 min in eight patients with the SBS. Indomethacin increased the initial cough threshold and reduced the increment in the post-15 min cough threshold from the initial value compared with placebo, thus reducing the tachyphylaxis. These results indicate that chronic airway inflammation may be responsible for the decreased response (tachyphylaxis) to repeated inhalation of capsaicin, and suggest that cyclooxygenase products released by the airway inflammation may be involved in tachyphylaxis, cough receptor sensitivity to inhaled capsaicin, or both, in patients with the SBS.

Adult↗
PubMed1992

Antidiuretic effects of purinoceptor agonists injected into the hypothalamic paraventricular nucleus of water-loaded, ethanol-anesthetized rats.

The effects of injection of various purinoceptor agonists into the hypothalamic paraventricular nucleus in water-loaded and ethanol-anesthetized rats were investigated. Adenosine triphosphate (ATP), beta,gamma-methyleneadenosine 5'-triphosphate (AMP-PCP) and beta,gamma-imidoadenosine 5'-triphosphate (AMP-PNP) potently decreased the outflow of urine in a time- and dose-dependent manner. The ED50 values were approx 70 and 37 nmol for ATP and AMP-PCP, respectively. Adenosine diphosphate (ADP), AMP and adenosine reduced the outflow of urine much less than ATP. Adenosine triphosphate induced concomitant increases in the osmotic pressure of the urine and in the level of arginine-vasopressin (AVP) in plasma. The antidiuretic effect of ATP was blocked by prior injection of quinidine (a P2-purinoceptor antagonist) into the paraventricular nucleus, but not by the prior injection of theophylline (a P1-purinoceptor antagonist). The effect of ATP was also blocked by intravenous injection of an AVP(V1V2)-receptor antagonist, d(CH2)5-D-Tyr(Et)VAVP. The results suggest that ATP injected into the paraventricular nucleus may stimulate a purinoceptor, releasing AVP and inducing the antidiuretic effect through renal AVP(V2) receptors.

Adenosine↗
PubMed1992

Solidifying liquid with novel initiation system for detachable balloon catheters.

In endovascular surgery, to permanently hinder blood inflow into an aneurysm for example, a catheter is percutaneously introduced into an artery and the balloon is positioned and inflated by a solidifying liquid and then released into the diseased part. A novel solidifying liquid for the inflated balloon curable under the continuous feeding of oxygen through the wall of the balloon is described here. Glucose oxidase which oxidizes glucose producing hydrogen peroxide was used for polymerization of the solidifying liquid. This solidifying liquid cured even in the presence of oxygen and water. It was radiopaque when mixed with the iodinated X-ray contrast chemical iopamidol. In addition, the solidified liquid had appropriate mechanical properties. The endovascular surgery could be carried out safely using it.

Catheterization↗
PubMed1992

RGD-albumin conjugate: expression of tissue regeneration activity.

Albumin conjugated with Arg-Gly-Asp (RGD) has cellular adhesive activity comparable to that of fibronectin in vitro. This study examined whether RGD-albumin conjugate (RGD-ALB) can promote soft tissue ingrowth into a porous matrix in vivo. Polyurethane sponges with 150-500 microns pore size adsorbed with RGD-ALB, fibronectin and albumin were implanted in the subcutaneous tissue of rats. The RGD-ALB-adsorbed sponge exhibited tissue ingrowth comparable to that of the fibronectin-adsorbed sponge at the early period of implantation. On the other hand, the tissue ingrowth was markedly retarded for non-adsorbed and albumin-adsorbed sponges. The enhanced tissue ingrowth found for RGD-ALB and fibronectin was deduced to be mainly a result of its cell-adhesion activity. It is concluded that RGD-ALB exhibits tissue ingrowth-promoting activity at the initial stage of wound healing as effectively as fibronectin.

Albumins↗
PubMed1992

Characterization of growth inhibitory factors for mouse monocytic leukemia cells.

Growth inhibitory (GI) factors for mouse monocytic leukemia cells were previously found in conditioned medium (CM) of a clone of mouse myeloblastic leukemia Ml cells (R1-GI factor) and in CM of mouse lung tissue (L-GI factor). In the present study, the effects of these GI factors on the growth of variant cell lines (Mm-A, Mm-P and Mm-S2) of mouse monocytic line Mm-1 cells were examined. Mm-A are highly leukemogenic to syngeneic SL mice, Mm-P cells are moderately leukemogenic, while Mm-S2 cells have little or no leukemogenicity. The R1-GI factor markedly suppressed the growth of Mm-A cells, whereas it inhibited the growth of Mm-P and Mm-S2 cells only moderately. Recombinant mouse interferon beta (IFN beta) had similar target specificities to those of the R1-GI factor on these variant cells. Moreover, anti-mouse IFN beta antibody completely neutralized the GI activity of the R1-GI factor on Mm-A cells. These results show that the R1-GI factor and mouse IFN beta are very similar and probably identical proteins. The L-GI factor had different target specificities from the R1-GI factor: it showed strongest GI activity on Mm-P cells, moderate GI activity on Mm-S2 cells and weak GI activity on Mm-A cells. Recombinant human interleukin 6 (IL-6) had similar target specificities to the L-GI factor on these Mm-1 variant cells. Furthermore, the L-GI factor could support the proliferation of IL-6-dependent MH60.BSF2 cells. Anti-mouse IL-6 antiserum neutralized the GI activity of the L-GI factor on Mm-P cells. Thus the L-GI factor and mouse IL-6 seem to be closely related and possibly to be identical proteins.

Animals↗
PubMed1992

Voltage-dependent capacitance as a probe for albumin adsorption onto a solid surface.

The process of adsorption of bovine serum albumin onto a platinum electrode was monitored through the measurement of a nonlinear electrochemical property. The principle of the new method is that a sinusoidal voltage source is applied to a test solution and the waveform of the output current is analyzed by Fourier transformation. It was found that the intensities of the higher harmonics in the Fourier transformation change depending on the concentration of albumin and with time. From the higher harmonics, voltage dependence of the capacitance was quantitatively evaluated. The change of the state of albumin adsorbed onto the platinum plate was also monitored from the pattern of 'crack' of adsorbed albumin by using scanning electron microscopy. These results were discussed in relation to the mechanism of bimodal adsorption of albumin.

Journal Article↗
PubMed1992

High-dose vitamin C therapy for extensive deep dermal burns.

We studied the haemodynamic effects of antioxidant therapy with high-dose vitamin C administration (170 mg/kg/24 h) in guinea-pigs with 70 per cent body surface area deep dermal burns. The animals were divided into three groups of six animals each. Group 1 was resuscitated with Ringer's lactate solution according to the Parkland formula; group 2 with 25 per cent of the Parkland formula with vitamin C; and group 3 with 25 per cent of the Parkland formula without vitamin C. There were no significant differences in heart rates or in blood pressures between the groups throughout the 24-h study period. Group 3 showed significantly higher haematocrit values at 3 h postburn and thereafter as compared with those of group 2. The cardiac output values of group 2 were significantly higher than those of group 3, but equivalent to those of group 1. The water content of the burned skin in group 2 was significantly lower than that in the other groups, indicating that increased postburn capillary permeability was minimized by the administration of vitamin C. With adjuvant high-dose vitamin C administration, we were able to reduce the 24-h resuscitation fluid volume from 4 ml/kg/per cent burn to 1 ml/kg/per cent burn, while maintaining adequate cardiac output.

Animals↗
PubMed1992

Outflow refreshment angiography: a bright blood, bright static tissue technique.

A new "bright blood" strategy, outflow refreshment imaging, is introduced in which a number of overlapping slices are excited in rapid succession. Flowing spins that refresh each overlapped slice portion contribute a bright signal. Additionally, static tissue in each non-overlapped slice portion also yields a bright signal. However, the flow/static contrast is comparable to that produced in inflow refreshment images, and angiograms can be generated by conventional maximum intensity projection processing. The dual ability to visualize angiograms and static tissue images is a major benefit of the strategy. Computer simulations of flow sensitivities and in vivo results are presented which compare the outflow and inflow refreshment imaging strategies.

Blood Flow Velocity↗
PubMed1992

Unilateral obstruction of the vas deferens caused by childhood inguinal herniorrhaphy in male infertility patients.

OBJECTIVE: To study the incidence, diagnosis, and treatment of unilateral obstruction of the vas deferens caused by inguinal herniorrhaphy (IH) during childhood. DESIGN: Retrospective. SETTING: Kyoto University Hospital. PATIENTS: Unilateral obstruction of the vas deferens after IH was diagnosed and treated in 10 of 724 subfertile patients. INTERVENTIONS: Reanastomosis of the vas deferens using a microsurgical two-layer technique. MAIN OUTCOME MEASURES: Follow-up seminal analysis of the patients and the occurrence of pregnancy in their wives. RESULTS: The incidence of unilateral vas deferens obstruction caused by IH was 26.7% for subfertile patients with a history of IH during childhood. Unilateral vas deferens obstruction was detected through palpation of the scrotal vas deferens in 7 of the 10 patients. After vasovasostomy, the semen quality improved in 5 patients, and pregnancy was achieved by 2 patients. CONCLUSIONS: The incidence of vas deferens obstruction was unexpectedly high in subfertile patients with a history of IH during childhood. Careful palpation of the scrotal content was a useful and noninvasive method to diagnose unilateral vas deferens obstruction, and microsurgical vasovasostomy was treatment of choice.

Adult↗
PubMed1992

Laparoscopic varicocelectomy: a simple technique for clip ligation of the spermatic vessels.

Less invasive laparoscopic surgery is replacing the conventional open operation for the treatment of several conditions. We performed laparoscopic clamping of the internal spermatic vessels in 12 subfertile patients to treat varicocele of the testis. Seven operations were performed with the patient under general anesthesia, whereas a local anesthetic was used in the 5 most recent patients. The internal spermatic vessels were successfully clipped in all 12 patients. Postoperative physical examination with a Doppler stethoscope showed that the venous reflux had disappeared in all patients. Semen quality was improved in 7 patients with a followup of 3 to 10 months. Neither hydrocele nor testicular atrophy was observed postoperatively. Laparoscopic varicocelectomy was effective and minimally invasive, especially when performed with the patient under local anesthesia.

Adult↗
PubMed1992

Abnormal distribution of IL-6 receptor in aged MRL/lpr mice: elevated expression on B cells and absence on CD4+ cells.

A mAb against murine IL-6 receptor (IL-6R), KMH7, was obtained by immunization of hamster with recombinant soluble murine IL-6R. Flow cytometry analysis of IL-6R distribution on lymphocytes in BALB/c showed that IL-6R was expressed on peripheral lymph node (LN) T cells of either CD4+ or CD8+ phenotype, and Peyer's patch IgA+ B cells, but not on splenic B cells and thymocytes. A similar distribution was observed in 5 week old MRL/lpr and 16-week-old MRL/n mice. In contrast, in 16 week old MRL/lpr mice of both sexes, IL-6R was expressed on splenic IgM+ cells. Peripheral LN CD4+ T cells in 16 week old female MRL/lpr mice did not express IL-6R. Thymocytes in any population with a phenotype of CD4+ or CD8+, double negative, and double positive were not stained with KMH7 in both BALB/c and MRL/lpr mice. In both strains, IL-6R was induced in CD4+ or CD8+ thymocytes after 2 days of culture, suggesting that CD4+ thymocytes in MRL/lpr have a potential to express IL-6R. Our results suggest that overexpression of IL-6R on B cells and absence of IL-6R on peripheral CD4+ cells are concurrent with, or may contribute to, B cell hyperreactivity and T cell abnormality in this strain.

Aging↗