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Biomedical subjects

Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 487 records · Page 27Linked to original sources
PubMed1997

Analysis of bile acids in colon residual liquid or fecal material in patients with colorectal neoplasia and control subjects.

Bile acids are believed to play a role in the etiology of colorectal cancer. To examine the relationship between bile acids and colorectal neoplasia, bile acids in colon residual liquid or fecal material were analyzed in 18 patients with colorectal adenoma, 12 patients with colorectal cancer, and 18 healthy control subjects. High-performance liquid chromatography combined with immobilized 3 alpha-hydroxysteroid dehydrogenase in column form showed a significant elevation in the proportion of deoxycholic acid (P < 0.05), lithocholic acid (P < 0.05), secondary bile acids (deoxycholic acid plus lithocholic acid) (P < 0.02), and the chenodeoxycholic acid-lithocholic acid family (chenodeoxycholic acid plus lithocholic acid) (P < 0.05) in the colon residual liquid or fecal material of the patients with colorectal adenoma compared with proportions in the control subjects. A similar trend was noted in the patients with colorectal cancer compared to the control subjects. These findings suggested that an increase in the proportion of secondary bile acids, in particular, of lithocholic acid, was closely related to the pathogenesis of colorectal neoplasia.

Adenoma↗
PubMed1997

Incidence of cardiac sarcoidosis in Japanese patients with high-degree atrioventricular block.

In Japan the majority of sarcoidosis-related deaths are due to cardiac sarcoidosis. One of the most common electrocardiographic abnormalities in patients with this disease is atrioventricular block. This study surveyed the incidence of cardiac sarcoidosis in Japanese patients (40 men and 49 women; mean age, 69.1 years) with high-degree atrioventricular block who were admitted to the hospital to receive a permanent pacemaker. We excluded cases in which sarcoidosis had been diagnosed from the involvement of other organs. Patients with the characteristic signs of sarcoidosis underwent echocardiography, radionuclide imaging, and biopsy. Ten cases (11.2%) of cardiac sarcoidosis were diagnosed, most frequently in women aged 40 to 69 years (8 of 25, 32%). Thus the possibility of cardiac sarcoidosis should be carefully considered in middle-aged or elderly Japanese women who show high-degree atrioventricular block.

Aged↗
PubMed1997

Clinical application of transluminal endovascular graft placement for aortic aneurysms.

BACKGROUND: In recent years, transluminal endovascular graft placement techniques have been developed for the treatment of aortic aneurysms. We report our initial clinical experience with endovascular graft placement using a graft developed in our laboratory. METHODS: The procedure was performed in 20 patients with a diagnosed aortic aneurysm. The graft is constructed from a Dacron cylinder, and the surface of the graft is supported with multiple rings of extraflexible wire. After the compactly folded graft is delivered through the sheath to the predetermined target point, the graft is deployed and then pressed against the vessel by balloon inflation. Straight graft insertion was attempted in 10 patients, bifurcated graft insertion in 8, and branched graft insertion in 2. RESULTS: Graft placement was successful in 19 of the patients and unsuccessful in 1. There were no cases of graft migration, aneurysm rupture, or graft destruction during a mean follow-up period of 9 months. CONCLUSIONS: Initial clinical results demonstrated the efficacy and safety of endovascular graft placement using this graft.

Adolescent↗
PubMed1997

Expression of vasoactive intestinal polypeptide receptor mRNA and secretory regulation by vasoactive intestinal polypeptide in rat submandibular and sublingual salivary glands.

Vasoactive intestinal polypeptide (VIP)-receptor mRNA was strongly expressed in the acinar cells in the submandibular gland but not in the sublingual gland. VIP-containing nerve fibres were richly distributed around acini in the submandibular gland but were rare around acini of the sublingual gland. In the submandibular gland, the chorda was stimulated at various frequencies (1-40 Hz) together with an infusion of (N-Ac-Tyr1, D-Phe2)-GRF(1-29)-NH2 (109 M), VIP antagonist, which reduced salivary flow from the submandibular gland only at high-frequency stimulation (> 20 Hz), and more markedly reduced the salivary protein concentration. When the chorda was continuously stimulated the antagonist reduced the salivary flow only during the initial 5 min. Exogenous VIP 10(-12) - 10(-8) M) infusion at the same time as chorda stimulation caused no increase in salivary flow, but the salivary protein concentration was increased in a dose-dependent manner. In the sublingual gland, neither VIP nor the VIP antagonist affected chorda-evoked salivary flow and protein concentration. Thus, endogenous VIP may play a part in the regulation of both fluid and protein secretion, especially of protein, evoked by chorda stimulation at high frequency in the submandibular gland. These phenomena occurred only in the initial phase of secretion. In the sublingual gland, it seems likely that VIP plays no part in the regulatory mechanism, at least with regard to salivary fluid secretion in the acinar cells.

Animals↗
PubMed1997

Effects of clomiphene citrate on the endometrial thickness and echogenic pattern of the endometrium.

OBJECTIVE: To study the effects of clomiphene citrate (CC) on the endometrium by ultrasound and to reveal the echogenic difference between the control cycle and the CC cycle. DESIGN: Retrospective study of patients before and during a CC treatment. SETTING: Department of Obstetrics and Gynecology, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan. PATIENT(S): Seventy-nine infertile women who had a spontaneous ovulation and a normal luteal function. INTERVENTION(S): Patients received 50 mg/d CC between days 5 and 9 of the menstrual cycle. MAIN OUTCOME MEASURE(S): Endometrial thickness, echogenic pattern of the endometrium, serum E2 content, and E2 and P receptor contents in the endometrium. RESULT(S): Endometrial thickness was significantly thinner during the CC cycle (7.6 +/- 1.4 mm, mean +/- SD, n = 79) than during the control cycle (8.5 +/- 1.7 mm, n = 79) on late proliferative days, but there was no significant difference on midsecretory days (10.8 +/- 2.2 mm during the CC cycle, n = 79; 11.2 +/- 2.2 mm during the control cycle, n = 79). The echogenic patterns, however, were different between the two cycles on midsecretory days. Moreover, the incidence in which patients showed a grade 3 endometrium on midsecretory days was significantly higher during the conceived CC cycle compared with the not-conceived CC cycle. Serum E2 levels were significantly higher, but E2 receptor contents in the endometrium were significantly lower during the CC cycle (67 +/- 46 fmol/mg, n = 13) compared with the control cycle (123 +/- 89 fmol/mg, n = 15) on late proliferative days. CONCLUSION(S): Clomiphene citrate affected the echogenic pattern of the endometrium, and most of the endometrium showed a grade 3 pattern on midsecretory days during the conceived CC cycle. Under the CC treatment, the comfortable endometrium for embryos might be different from the control cycle.

Adult↗
PubMed1997

Adenovirus-mediated transfer of tissue-type plasminogen activator gene to human endothelial cells.

BACKGROUND: Seeding of vascular grafts with genetically engineered human endothelial cells (hECs) secreting antithrombogenic or fibrinolytic agents has considerable clinical potential. METHODS: An adenoviral vector was used to transfer the human tissue-type plasminogen activator (htPA) gene to hECs, and the ability of the transduced hECs to secrete htPA was examined. Cultured hECs on plates were incubated with various concentrations of recombinant adenoviruses containing the htPA or LacZ gene for various times to determine the optimal transfer conditions. Transduced hECs were seeded onto fibronectin-coated expanded polytetrafluoroethylene grafts (4 mm in diameter), some of which were exposed to pulsatile flow in vitro. RESULTS: Effective transduction of the htPA gene into hECs (htPAhECs) was achieved with viral soup at a multiplicity of infection of 30 after incubation for 1 day, which yielded 4.8 +/- 0.20 x 10(3) ng/10(6) cells/6 hr htPA antigen on plates (n = 3), 2.2 +/- 2.0 x 10(3) ng/10(6) cells/6 hr on grafts (n = 6), and 6.8 +/- 1.7 x 10(2) ng/10(6) cells/6 hr on perfused grafts (n = 6). The retention of htPAhECs by perfused grafts was 84.0% +/- 3.0%, comparable with the noninfected (82.1% +/- 8.0%) and mock-infected (94.2% +/- 0.4%) hEC values. CONCLUSIONS: By adenoviral vector-mediated gene transfer, 10(2-3)-fold enhancement of htPA secretion was demonstrated, which did not affect cell retention by grafts.

Adenoviridae↗
PubMed1997

Mode of disease progression in primary myelodysplastic syndromes: a Japanese co-operative study. The Refractory Anemia Study Group of The Ministry of Health and Welfare, Japan.

Chronological changes in hematological findings were analyzed in 225 patients with myelodysplastic syndromes (MDS). They were diagnosed between 1990 and 1992. Their hematological findings, i.e. hemoglobin levels, leukocyte and platelet counts, proportions of peripheral blood (PB) blasts and monocytes, and proportion of blasts in bone marrow (BM), were recorded for up to 42 months after diagnosis, when available. BM was examined regularly in only a few patients. Therefore, it was impractical to use the French-American-British Cooperative Group criteria for subtype classification during the disease course. Thus, we used the percentage of PB blasts as the only indicator of stage evolution. We classified the disease into four stages: stage 1, less than 1% PB blasts; stage 2, 1-5% PB blasts; stage 3, 5-30% PB blasts; and stage 4, 30% or more PB blasts. There were 171 patients initially in stage 1, 37 initially in stage 2, and 17 initially in stage 3. Less than half (45%) of the patients initially in stage 1 progressed to stage 2, while 91% of the patients initially in stage 2 and all of the patients initially in stage 3 showed stage evolution. Eight variables, i.e. BM blasts 5% or more, male sex, karyotypic abnormalities, micromegakaryocytes, mononuclear large megakaryocytes, platelet counts 50 x 10(9)/l or higher, abnormal nucleus of granulocytes, and abnormal granules of granulocytes, were found to be significant risk factors for evolution from stage 1 to 2. Evolution from stage 1 to a higher stage within 15 months of diagnosis was associated with impending poor prognosis in most patients. However, of the 67 patients initially in stage 1 who died, 30 did not show stage evolution. Evolution from stage 2 to a higher stage and from stage 3 to stage 4 was also associated with impending poor prognosis. Higher levels of cytopenia were not associated with poorer prognosis in the stage 1 patients. In conclusion, our grading system proved to be useful in evaluating the chronological changes in MDS patients.

Disease Progression↗
PubMed1997

Ca2+/Mg(2+)-dependent endonuclease in marrow CD34 positive and erythroid cells in myelodysplasia.

Endonucleases capable of producing internucleosomal DNA cleavage are one of the key enzymes in apoptosis. We examined endonuclease activities contained in nuclei of CD34+ and erythroid cells in the bone marrow (BM) from 12 patients with the myelodysplastic syndromes. The levels of Mg(2+)-dependent and acidic endonucleases showed little changes as compared with those from normal BM. By contrast, the level of Ca2+/Mg(2+)-dependent endonuclease was appreciably higher in MDS erythroid cells than normal counterparts, although the activity varied markedly in CD34+ and erythroid cells. Our results suggested that Ca2+/Mg(2+)-dependent endonuclease is related to ineffective erythropoiesis in MDS.

Adult↗
PubMed1997

B cell stimulating activity of seaweed extracts.

The activity of seaweed extracts on murine and human lymphocytes was studied in vitro. The extracts of some kind of seaweed, such as Hizikia fusiformis and Meristotheca papulosa, stimulated normal mouse spleen cells to proliferate. The responder cells are B cells, because the response was depleted by the treatment of spleen cells with anti-immunoglobulin (Ig) antibody and complement and being passed through a nylon wool column. This response is not due to lipopolysaccharide (LPS) contamination, because seaweed extracts can stimulate spleen cells of C3H/HeJ mice which are LPS low responders. Seaweed extracts also enhanced Ig production by B cells and tumor necrosis factor (TNF) production by macrophages. Furthermore, seaweed extracts stimulated human lymphocytes to proliferate. All these B cell stimulating activities of seaweed extracts associated with glycoproteins whose molecular weights resided in 100 kD. These results suggest that seaweed extracts have stimulating activity on B cells and macrophages and this ability could be clinically for the modulation of immune responses.

Animals↗
PubMed1997

Immunomodulating activity of Chinese medicinal herbs and Oldenlandia diffusa in particular.

The effect of eight different Chinese medicinal herbs (CMHs) on lymphocytes was studied in vitro using murine spleen cells. Among the studied eight CMHs, Astragalus membranaceus and Oldenlandia diffusa markedly stimulated murine spleen cells to proliferate. The responder cells for CMHs were B cells, because the response was depleted by the treatment of spleen cells with anti-immunoglobulin (i.g.) antibody and complement and after purification by nylon wool column. This response was not due to contamination by lipopolysaccharide (LPS), because CMHs could stimulate C3H/HeJ spleen cells which are low responders to LPS. CMHs enhanced the production of Ig. CMHs also enhanced the induction of allo-antigen specific cytotoxic T lymphocytes. However, CMHs had no effect on natural killer cells. Furthermore, CMHs stimulated macrophages to produce interleukin-6 and tumor necrosis factor. The electroelution of the proteins from SDS-PAGE gel showed that the active components of Oldenlandia diffusa had an apparent molecular weight of 90-200 kD and were sensitive to pronase E and NaIO4 treatment, suggesting glycoproteins in nature. These results suggest that CMHs have immunomodulating activity in vitro and this activity could be used clinically for the modulation of immune responses.

Adjuvants, Immunologic↗
PubMed1997

Assessment of encephalo-galeo-myo-synangiosis with dural pedicle insertion in childhood moyamoya disease: characteristics of cerebral blood flow and oxygen metabolism.

In the surgical treatment of childhood Moyamoya disease, we have been performing a new non-anastomotic bypass surgery using encephalo-galeo-myo-synangiosis (EGMS) with dural pedicle insertion over the brain surface. To assess the results obtained using this procedure, the long-term clinical outcome and the characteristics of cerebral blood flow and oxygen metabolism using PET were evaluated. The subjects were 19 patients with childhood Moyamoya disease admitted to our institution over 8 years from 1988 to 1996. This type of surgery was performed 39 times and the patients have been followed up from 10 months to 8 years. Preoperatively, although cerebral blood flow and oxygen metabolism were varied from individual to individual, low values of regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of oxygen (rCMRO2) with relatively high values of regional oxygen extraction fraction (rOEF) were found in the frontal region in most of the patients compared to normal children. Postoperatively, obvious improvement of cerebral blood flow and hemodynamics in all the areas in the operative site and clinical symptoms and signs ameliorated or disappeared during the follow-up period. In conclusion, the present method appeared to be useful to improve the hemodynamic in the brain and its long-term clinical outcome was satisfactory.

Age Distribution↗
PubMed1997

Effect of a prostaglandin I2 analogue, beraprost sodium, on burn-induced gastric mucosal injury in rats.

Stress ulcers still have a high mortality in critically burned patients and the pathophysiology remains relatively unknown. Impaired gastric mucosal perfusion is one of the factors contributing to gastric mucosal ulceration. Burn injury causes thrombosis and vascular occlusion by increasing the blood viscosity, resulting in decreased organ perfusion. Reduced blood flow is one of the most important factors in gastric mucosal ulceration. Beraprost sodium is a chemically stable prostaglandin I2 (PGI2) analogue with antiplatelet, vasodilator and cytoprotective actions. In the present study, we examined the effects of a PGI2 analogue, beraprost sodium (Procylin, Kaken Pharmaceutical Company, Tokyo, Japan) on burn-induced gastric mucosal changes in rats. Twenty male Sprague-Dawley rats weighing an average of 400 g were burned with hot water (90 degree C) and then divided into two groups of 10 animals. One group received 0.015 mg of beraprost sodium intraperitoneally immediately after burn injury, while the control group received the same volume of saline. Gastric mucosal blood flow was measured with a laser Doppler flowmeter and the area of mucosal necrosis was also determined macroscopically and histologically. Gastric mucosal damage was significantly reduced in the beraprost sodium-treated rats and gastric mucosal blood flow was significantly improved (p < 0.05). These findings demonstrate that PGI2 plays a very important role in the pathophysiology of burn-induced Curling's ulcer and that beraprost sodium can improve gastric mucosal blood flow and reduce mucosal damage.

Animals↗
PubMed1997

Reduction of burn-induced gastric mucosal injury by an endothelin receptor antagonist in rats.

Burn-induced stress ulcers may be a major complication in critically burned patients. The pathophysiology of gastric mucosal ulceration is relatively unknown, however reduced gastric mucosal blood flow is one contributing factor. Endothelin (ET) is a well known vasoconstrictor peptide produced by vascular endothelial cells. Endothelin has been reported to have a fundamental role in the regulation of the systemic circulation. The plasma ET level is increased by burn injury, which also causes thrombosis and vessel occlusion. Endothelin has potent ulcerogenic and vasoconstrictor actions in the stomach where it induces gastric mucosal damage and increases gastric vascular tone. In the present study, we examined the effects of a new non-selective ET receptor antagonist, TAK-044, on burn-induced gastric mucosal injury in rats. Twenty male Sprague-Dawley rats weighting an average of 400 g were burned with hot water (90 degrees C) and then divided into two equal groups. The treatment group received 1 mg/kg of TAK-044 via the dorsal vein of the penis immediately after burn trauma, while the control group received the same volume of saline. Gastric mucosal blood flow was measured with a laser Doppler flowmeter and the area of mucosal necrosis was also determined macroscopically and histologically. Inhibition of ET activity by TAK-044 after burn injury significantly improved microvascular perfusion in the gastric mucosa and prevented the progression of mucosal damage in the stomach (P < 0.05). The present study supports the role of ET in burn-induced gastric ulceration (Curling's ulcer).

Animals↗
PubMed1997

Experimental approaches for the treatment of murine B16 melanomas of various sizes. I: Local injection of ethanol with a combination of interleukin-2 or microwaval hyperthermia for B16 melanomas with a size of less than 7 mm in diameter.

The effects of local absolute ethanol injection combined with administration of interleukin-2 (IL-2) or microwaval hyperthermia in murine B16 melanomas with a size of approximately 7 mm in diameter were investigated. The groups of melanoma-burdened mice treated with both local ethanol injection and local or intra-abdominal administration of IL-2 showed clear suppression of any recurrence of melanoma once the melanomas had been destroyed by ethanol injection and a concomitant prolongation of the survival times. Also, local injection of ethanol in combination with local microwaval hyperthermia at 43 degrees C for 15 min twice a week caused complete cures in B16 melanomas with a size of less than 7 mm in diameter. The infiltrations of T lymphocytes and NK cells were augmented in the melanomas treated with ethanol injection and local injection of IL-2. However, the melanomas treated with ethanol injection and intra-abdominal injection of IL-2 hardly showed any infiltration of such immune cells, although the growth of melanomas was effectively suppressed. In the case of treatment with ethanol and hyperthermia, slight infiltration of NK cells was observed in the melanoma nests as well as in the interstitials. Thus, the direct injection of absolute ethanol in combination with IL-2 or microwaval hyperthermia is effective or even curative in the treatment of murine B16 melanomas with a size of less than 7 mm in diameter.

Animals↗