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Biomedical subjects

S Umemoto

Publications and source records attributed to S Umemoto.

At least 19 recordsLinked to original sources
PubMed2002

Cimetidine increases survival of colorectal cancer patients with high levels of sialyl Lewis-X and sialyl Lewis-A epitope expression on tumour cells.

Cimetidine has been shown to have beneficial effects in colorectal cancer patients. In this study, a total of 64 colorectal cancer patients who received curative operation were examined for the effects of cimetidine treatment on survival and recurrence. The cimetidine group was given 800 mg day(-1) of cimetidine orally together with 200 mg day(-1) of 5-fluorouracil, while the control group received 5-fluorouracil alone. The treatment was initiated 2 weeks after the operation and terminated after 1 year. Robust beneficial effects of cimetidine were noted: the 10-year survival rate of the cimetidine group was 84.6% whereas that of control group was 49.8% (P<0.0001). According to our previous observations that cimetidine blocked the expression of E-selectin on vascular endothelium and inhibited the adhesion of cancer cells to the endothelium, we have further stratified the patients according to the expression levels of sialyl Lewis antigens X (sL(x)) and A (sL(a)). We found that cimetidine treatment was particularly effective in patients whose tumour had higher sL(x) and sL(a) antigen levels. For example, the 10-year cumulative survival rate of the cimetidine group with higher CSLEX staining, recognizing sL(x), of tumours was 95.5%, whereas that of control group was 35.1% (P=0.0001). In contrast, in the group of patients with no or low levels CSLEX staining, cimetidine did not show significant beneficial effect (the 10-year survival rate of the cimetidine group was 70.0% and that of control group was 85.7% (P=n.s.)). These results clearly indicate that cimetidine treatment dramatically improved survival in colorectal cancer patients with tumour cells expressing high levels of sL(x) and sL(a).

Administration, Oral↗
PubMed2002

Application of an automatic sampling and measurement system to a mountainous stream investigation during rain events.

An automatic sampling and measurement system was developed to take water samples efficiently during rain events. The system consisted of an automatic sampler, a rain gauge and a data logger as well as sensors for pH, electrical conductivity (EC), and both water and air temperature. The system was tested in a stream in a forested watershed (5.8 km2) located in the middle of Hyogo prefecture, Japan. The sampling program has been improved gradually. For several rain events of 30 to 157 mm, most water samples were in agreement with the hydrograph from the beginning of each rainfall until the rain had stopped and the water level had begun to fall. The fluctuations in water quality in the samples taken by the automatic sampler during those rain events showed patterns similar to those of water samples taken by hand. There were also no problems with the water level or the EC sensor during the investigation periods, but the pH values were lower than those in the laboratory. The results showed that the system is suitable for taking water samples from mountainous streams during rain events.

Altitude↗
PubMed2001

Characterization of T cell receptor beta chains of accumulating T cells in chronic ongoing myocarditis demonstrated by heterotopic cardiac transplantation in mice.

Autoimmne mechanisms have been implicated in the pathogenesis of chronic ongoing mycarditis. An earlier study of murine chronic ongoing myocarditis reported that infiltrating T cells and macrophages were prominent in the normal donor heart, in a heterotopic cardiac transplantation model. It was demonstrated that myocarditis was transferred to a normal heart transplanted into a mouse with chronic myocarditis. The present study investigated an autoimmune link to the pathogenesis of chronic ongoing myocarditis by analyzing the T cell clonalities in the model. To characterize the accumulating T cells in the donor heart, the T cell receptor beta genes (TCRBG) were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) from mRNA in the donor hearts and accumulating TCRBG clonotypes were contrasted with those from recipient hearts. Inbred 3-week-old A/J mice were inoculated intraperitoneally with Coxsackievirus B3 (Nancy strain), 2 x 10(4) PFU, and housed for more than 60 days. Normal A/J mouse hearts were transplanted into the same strain of mice without myocarditis, as well as into the mice with chronic ongoing myocarditis. Both recipient and donor hearts were evaluated histologically 2 weeks after the transplantation. TCRBG were amplified by RT-PCR from mRNA of recipient and donor hearts and spleens. The specific accumulating TCRBG clonotypes were identified by their single strand conformation polymorphism. Multiple clonotypic accumulations occurred in the donor heart after cardiac transplantation. Distinct oligoclonal accumulation of TCR Vbeta1, 10, and 13 T cells was found in both recipient and donor hearts in 3 of 4 mice. Moreover, these clonotypes were not observed in spleen cells of the recipient mice. T specific cells expanding clonotypes of TCRBG are responsible for transferring myocarditis to the donor heart. An autoimmune response may, therefore, play a key role in the progression of chronic ongoing myocarditis.

Animals↗
PubMed2001

Heterogeneous expression of nonmuscle myosin heavy chain-B in mesangial cells of patients with Gitelman's syndrome.

AIMS: It has been suggested that angiotensin II (Ang II) promotes hypertrophy and hyperplasia of mesangial cells. Nonmuscle myosin heavy chain-B (NMHC-B) and alpha-smooth muscle (SM) actin are considered to be molecular markers for phenotypic change ofproliferative mesangial cells. One of the clinical characteristics in Gitelman's syndrome (GS) is the elevation of plasma Ang II. However, little is known about the relation between Ang II and phenotypic change of mesangial cells in patients with GS. In this report, we examined the expression of NMHC-B and alpha-SM actin in mesangial cells of two GS patients. MATERIALS AND METHODS: Plasma renin activity, and the concentrations of Ang II, 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha), urinary kallikrein, and 6-keto-PGF1alpha were measured. Immunohistochemical staining of NMHC-B and alpha-SM actin in mesangial cells of GS patients was also performed. RESULTS: Both cases of GS showed normal glomerular function, few histological abnormalities, and higher than normal plasma concentrations of renin and Ang II. Furthermore, one case showed a high urinary concentration of kallikrein and the expression of both NMHC-B and alpha-SM actin in mesangial cells. The other case showed a high urinary concentration of 6-keto-PGF1alpha but not kallikrein and without the expression of NMHC-B and alpha-SM actin. CONCLUSION: Not only plasma kinin-kallikrein and prostaglandins, but the renal expression of NMHC-B and alpha-SM actin may be variable in different patients with GS.

Actins↗
PubMed2001

Runoff characteristics of major ionic species during rain events in forested watershed.

The runoff characteristics of major ionic species from a stream in a forested watershed were investigated during two rain events. The values of EC and the concentrations of alkalinity, anions and cations, except for NO3-, decreased according to the increase of discharge, and showed a sharp lower peak. On the other hand, the concentrations of NO3- and K+ indicated an opposite change. The amount of output of anions and cations was also larger than those of the input, especially in a storm event. During a storm event, the NO3- concentrations in soil water 20 cm deep taken by a tension lysimeter were not detected, even though the surface soil of 0-5 cm deep included 20 to 50 mg/kg of NO3-. The direct contribution for NO concentrations by suspended solids in water was estimated through three percentages of the stream water output. Surface runoff was also not observed. These results suggest that the prompt subsurface runoff of the direct runoff from surface layer of soil may be predominant during rainfall in the forested area, and the increase of NO3- concentrations in the stream may be caused through the process.

Environmental Monitoring↗
PubMed2001

Runoff characteristics of nutrients in the forest streams in Hyogo Prefecture, Japan.

Nutrients and other pollutant runoffs from streams in artificial forest areas in central Hyogo Prefecture in southwest Japan have been investigated to estimate pollutant loads since 1995. The orthophosphate and ammonium nitrogen contents were usually low and constant during the investigation. When the flowrates of the streams were normal, the concentrations of suspended solids, COD(Mn), TOC and total phosphorus were very low, and did not change much. However, when stream flows were increased by rainstorms or other precipitation, higher concentrations of these parameters occurred. Otherwise, the average concentrations of nitrate nitrogen and total nitrogen were 0.26 mg/l and 0.31 mg/l, respectively, and they were often increased by precipitation events. They changed at the same time because the ratio of nitrate nitrogen per total nitrogen was high, about 80%. The fluctuation of concentrations of total phosphorus was similar to SS concentrations, which suggested that phosphorus was discharged in the types of suspended solids from forest areas. The specific loads of the nutrients and some other pollutants did not differ among the three watersheds investigated. However, the difference among them between fine days and rainy days was fairly large. It was presumed that pollutant runoff from forest areas is strongly dependent on precipitation events.

Agriculture↗
PubMed2000

Eosinophil counts and plasma fibrinogen in patients with vasospastic angina pectoris.

Epidemiologic studies have suggested a relation between white blood cell (WBC) counts and the incidence of coronary heart disease. However, the relation between vasospastic angina pectoris (VAP) and WBC counts remains to be elucidated. To clarify the relation between differential and WBC counts in VAP, we compared the hematologic values, blood chemical values, plasma fibrinogen levels, C-reactive protein levels, and coronary risk factors in patients with spontaneous attacks of VAP (n = 39) with those in patients with stable effort angina pectoris (EAP, n = 35) and in control subjects (n = 19). Patients with VAP were further divided into mild VAP (n = 22) and severe VAP groups (n = 17). There were no differences in the coronary risk factors, body temperature, total WBC counts, and C-reactive protein levels among the control, EAP, mild VAP, and severe VAP groups, except that the high-density lipoprotein cholesterol in the EAP group was significantly lower than that in the control group (p <0.01). In contrast, the eosinophil counts were significantly higher in the severe VAP group than in the other 3 groups (p <0.01). Plasma fibrinogen levels were also significantly higher in the severe VAP group than in the other 3 groups (p <0.05). The follow-up study for differential and WBC counts in patients with VAP (n = 23) demonstrated that, after medical therapy, the eosinophil counts were significantly decreased to the some level as those in the control group (p <0.0001). Thus, the eosinophil counts and plasma fibrinogen levels could predict the severity of VAP. Furthermore, a follow-up study in patients with VAP suggests that coronary vasospasm could result in an increase in eosinophil counts.

Angina Pectoris↗
PubMed2000

Dilazep, a nucleoside transporter inhibitor, modulates cell cycle progression and DNA synthesis in rat mesangial cells in vitro.

The direct effects of the nucleoside transporter inhibitor dilazep on the cell cycle of mesangial cells have not before been investigated. The purpose of this study was to elucidate whether dilazep can inhibit the proliferation of mesangial cells and how it interferes with the cell cycle of these cells. DNA histograms were used and BrdUrd uptake rate was measured by flow cytometry. There was no significant difference in the cell numbers among the untreated group and the 10(-5) M, 10(-6) M or 10(-7) M dilazep-treated groups at 24 h of incubation. However, at 48 and 72 h, the cell numbers in the dilazep-treated groups were significantly lower compared with that of the untreated group (P < 0.005). The DNA histograms of cultured rat mesangial cells at 12, 24, and 48 h of incubation with 10(-5) M dilazep showed that the ratio of the S phase population in the dilazep-treated group decreased by 2.2% at 12 h, by 9.6% at 24 h, and by 18.9% at 48 h compared with the untreated group. The ratio of the G0/G1 phase population in the dilazep-treated group significantly increased: 6.8% at 12h (P < 0.05), 13.9% at 24 h (P < 0.001), and 76.5% at 48 h (P < 0.001) compared with the untreated group. A flow cytometric measurement of bivariate DNA/BrdUrd distribution demonstrated that the DNA synthesis rate in the S phase decreased after 6 h (P < 0.005) and 12 h (P < 0.05) of incubation compared with the untreated group. These results suggest that dilazep inhibits the proliferation of cultured rat mesangial cells by suppressing the G1/S transition by prolonging G2/M and through decreasing the DNA synthesis rate.

Animals↗
PubMed2000

Mixed connective tissue disease with multiple organ damage: successful treatment with plasmapheresis.

A 24-year-old-woman with mixed connective tissue disease (MCTD) developed multiple organ failure, disseminated intravascular coagulation (DIC), metabolic acidosis, and respiratory and renal failure resulting from visceral vasospasm, so-called visceral Raynaud's phenomenon. After plasmapheresis, the condition of multiple organ failure was markedly improved. The successful treatment with plasmapheresis was dependent upon the removal of immune complexes in serum and improvement of visceral circulation. Thus plasma exchange is recommended as a possible a treatment for multiple organ damage in MCTD.

Acidosis↗
PubMed1999

Angiotensin II type 1 receptor antagonist downregulates nonmuscle myosin heavy chains in spontaneously hypertensive rat aorta.

The aim of this study was to clarify the differences between the angiotensin II type 1 (AT1) receptor antagonist and the angiotensin-converting enzyme (ACE) inhibitor on smooth muscle and nonmuscle myosin heavy chain isoforms in aortic smooth muscle cells of Wistar-Kyoto rats and spontaneously hypertensive rats. All 4 myosin heavy chain isoforms are heterogeneously expressed in the smooth muscle cells of the aortic tunica media in 20-week-old rats, and the contractile-type myosin heavy chains are highly expressed in smooth muscle cells of the aortic tunica media compared with the synthetic-type myosin heavy chains. Both the AT1 receptor antagonist and the ACE inhibitor had the same effects on hemodynamics, smooth muscle cell hypertrophy and proliferation, fibrosis, and vascular remodeling in spontaneously hypertensive rats. However, the AT1 receptor antagonist had a more potent effect on the downregulation of the synthetic-type myosin heavy chains than the ACE inhibitor in spontaneously hypertensive rat aortic tunica media. In contrast, these effects of the AT1 receptor antagonist and the ACE inhibitor on hemodynamics, morphology, fibrosis, and expression of myosin heavy chain isoforms in smooth muscle cells of the aortic tunica media were not observed in Wistar-Kyoto rats. Thus, within 6 weeks, the AT1 receptor antagonist might modulate the cellular composition of myosin heavy chain isoforms in smooth muscle cells more efficiently than the ACE inhibitor, without morphological changes in the spontaneously hypertensive rat aorta.

Angiotensin Receptor Antagonists↗
PubMed1999

Fas expression and apoptosis correlate with cardiac dysfunction in patients with dilated cardiomyopathy.

Fas is a transmembranous glycoprotein that mediates apoptosis. To elucidate the roles of Fas and of myocyte apoptosis in patients with dilated cardiomyopathy (DCM), the expression of Fas and the fragmentation of DNA were compared in endomyocardial biopsy specimens obtained from patients with DCM. Endomyocardial biopsy was performed on 19 subjects (16 with DCM and 3 control subjects) who also underwent cardiac catheterization and echocardiography. Fas and bcl-2 expression were assayed immunohistochemically, and in situ TdT staining was performed to estimate the number of apoptotic cells. Samples from the DCM patients stained more intensely with anti-Fas antibody than those from control patients (p<0.05). The percentage of in situ TdT-positive cells was significantly higher in the DCM group than in the control group (p<0.05). A correlation between Fas expression and in situ TdT staining was observed in 67% of myocytes in the DCM group. Moreover, the percentage of in situ TdT staining was significantly higher in subjects with severely impaired left ventricular systolic function than in those whose systolic function was mild to moderately impaired, or who had normal systolic function (p<0.05). The samples showed little expression of bcl-2. These results suggest that Fas expression and apoptosis may be involved in the progression of cardiac dysfunction in DCM.

Adult↗
PubMed1999

Repetitive coxsackievirus infection induces cardiac dilatation in post-myocarditic mice.

The relation between mycarditis and dilated cardiomyopathy (DCM) is controversial. To clarify the pathogenic mechanism of these diseases, the present study examined the effect of repetitive inoculation with coxsackievirus B3 (CVB3) in post-myocarditic mice. Inbred 3-week-old A/J mice were inoculated intraperitoneally with CVB3 (Nancy strain; 2x10(4) plaque-forming units) and reinfected in the same manner with CVB3 at 40 weeks (3W+/40W+). All mice were killed at 42 weeks old. The weight of the hearts of the 3W+/40W+ group were significantly increased compared with those of the 3W-/40W+ group, and both the heart weight/body weight and lung weight/body weight ratios of the 3W+/40W+ group were also significantly increased over those of the 3W-/40W- group, although the levels of serum neutralizing antibody titers were significantly increased in the 3W+/40W+ group over the level of the other groups. No increase in inflammatory cell infiltration or fibrosis progression was observed in the 3W+/40W+ group relative to the 3W+/40W- group, but the second inoculation resulted in a significant left ventricular dilatation and in left and right ventricular free wall thinning (3.31+/-0.20 mm vs 2.61+/-0.19 mm, p<0.05; 0.54+/-0.09 mm vs 0.72+/-0.16 mm, p<0.05, respectively). The sarcomere length was also significantly increased in the 3W+/40W+ group compared with that of the other groups, as determined by electron microscopy. Degenerative or necrotic areas in the infected hearts were not stained with anti-mouse IgG antibody, but were stained, only in 3W+/40W+ mice, with anti-mouse IgM antibody. The concentrations of TNF-alpha in the hearts of the 3W+/40W+ group were increased significantly over those of the 3W+/40W- group. Repetitive CVB3 infection produced cardiac dilatation without inflammatory cell infiltration in post- myocarditic mice. Autoimmunity mediated by the circulation of certain antibodies (eg, antibodies against the CVB3 genome or a CVB3-related protein) may be part of the pathogenic mechanism for this phenomenon. Thus, repetitive virus infection might contribute to the pathogenesis of cardiac dilatation.

Animals↗
PubMed1997

A tactile sensor for laparoscopic cholecystectomy.

During laparoscopic surgery, surgeons observe the three-dimensional abdominal cavity on a two-dimensional TV monitor, which is a limitation. Another limitation is that surgeons are unable to estimate the softness of organs or tissues during laparoscopic surgery as they are only allowed to use instruments which touch objects and direct palpation is not permitted during the procedure. The tactile sensor which we used displays the object softness immediately as a digital score, which can then be superimposed on a TV monitor as a graph. With the tactile sensor, we were able to ascertain the presence of a gallstone in the gallbladder or cholecystic duct during laparoscopic cholecystectomy and also able to discriminate between a stone and an air bubble during intraoperative cholangiography. We were convinced that the tactile sensor would be useful in laparoscopic surgery, which does not permit surgeons to palpate objects with human fingers.

Cholangiography↗
PubMed1997

The effects of phacoemulsification cataract surgery via local anesthesia on preoperative and postoperative blood pressure levels.

PURPOSE: The authors prospectively evaluated the preoperative and postoperative blood pressure (BP) levels of 2270 patients with cataracts. METHODS: All surgeries were performed by the same surgeon using the same method of phacoemulsification and aspiration (PEA) with posterior chamber intraocular lens implantation with the patients under local anesthesia. RESULTS: The daily systolic BP was 140.7 +/- 22.9 mmHg; the preoperative and postoperative systolic BPs were 149.5 +/- 23.9 and 145.6 +/- 23.8, respectively. The tendency for the preoperative BPs to increase and the postoperative BPs to decrease also was evident in the diastolic and the mean BPs. However, when the authors categorized the cases into normal, intermediate, and hypertension groups, the preoperative BP increased less and the postoperative BP decreased more when the daily BP was higher. CONCLUSION: Overall, the daily, preoperative, and postoperative BPs were relatively stable with the patients under local anesthesia. However, the BP change was characteristic of each group when the patients were categorized as normal, intermediate, and hypertensive. Surgeons should be aware of the greater-than-anticipated BP change during cataract surgery.

Adult↗
PubMed1997

Chronic glucocorticoid administration as well as repeated stress affects the subsequent acute immobilization stress-induced expression of immediate early genes but not that of NGFI-A.

We reported that repeated immobilization for six days attenuates the subsequent acute immobilization stress-induced expression of the immediate early genes c-fos, fos B, jun B and nerve growth factor-induced gene-B (NGFI-B), but not of NGFI-A, in the rat paraventricular hypothalamic nucleus. In this study, we confirmed these findings by means of a time-course study, and further investigated whether the elevated plasma basal glucocorticoid level induced by repeated stress underlies the attenuated response of immediate early genes and the preserved reactivity of NGFI-A. Rats implanted with 100, 200 or 400 mg corticosterone or placebo pellets (control), were immobilized for 1 h and decapitated seven days later. In control rats acute immobilization induced c-fos, fos B, jun B, NGFI-A and NGFI-B messenger RNA in the paraventricular hypothalamic nucleus, whereas all of them except NGFI-A, were significantly reduced in rats given 200 and 400 mg corticosterone implants. The similarity of the results from the two procedures suggests that glucocorticoid is involved in regulating immediate early genes in the paraventricular hypothalamic nucleus under repeated stress and that the NGFI-A gene is not regulated by this mechanism. However, the plasma basal corticosterone level in repeatedly stressed rats was lower than that of rats implanted with 100 mg corticosterone, suggesting that a repetitive stress-induced corticosterone surge also contributes to this mechanism.

Animals↗
PubMed1997

In vivo aortic wall characteristics at the early stage of atherosclerosis in rabbits.

To assess whether vascular responsiveness to alpha-receptor agonist is altered at the early stage of atherosclerosis, in vivo aortic pressure-diameter relationship of the aorta over a wide range of pressures was analyzed before and after the acute administration of alpha-receptor agonist (phenylephrine) in nine hypercholesterolemic fat-fed (7-wk-old) rabbits and eight normal diet-fed (7-wk-old) rabbits. In hypercholesterolemic fat-fed rabbits, there was no major structural change in the aortic wall except fatty streak, despite a marked increase in the level of plasma cholesterol, indicating the early stage of atherosclerosis of the aorta. By using a modified three-element Maxwell model, diastolic stress-strain relationship was computed after applying several assumptions to the actual aortic pressure-diameter relationship. After the intravenous administration of phenylephrine at a rate of 5 micrograms.kg-1.min-1, the stress (ordinate)-strain (abscissa) relationship curves were shifted to the left, indicating the activation of aortic smooth muscle by phenylephrine. The difference between the stress before and after phenylephrine showed a single peak at a certain strain. The peak difference in the stress was smaller in hypercholesterolemic fat-fed rabbits than in normal diet-fed rabbits, indicating the reduction of vascular responsiveness at the early stage of atherosclerosis of the aorta.

Adrenergic alpha-Agonists↗