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Biomedical subjects

Y Oishi

Publications and source records attributed to Y Oishi.

At least 73 records · Page 4Linked to original sources
PubMed1998

Coronary flow velocity patterns immediately after reperfusion reflect the pathologic characteristics of reperfused myocardium in canine models of acute myocardial infarction.

BACKGROUND: It is difficult to evaluate the extent of myocardial injury after successful reperfusion following acute myocardial infarction (AMI). We investigated the relationship between the coronary flow velocity pattern immediately after reperfusion and pathologic characteristics after myocardial reperfusion injury in dogs. METHODS: We measured distal coronary flow velocity variables in the left circumflex coronary artery in a canine model of AMI (n = 12) 10 min after the release of a clamp (3-10 h clamp procedure) using a 0.35 mm Doppler guide-wire. Dogs were divided into two groups according to presence or absence of early systolic retrograde coronary flow. Hearts were excised 2 h after reperfusion and examined histopathologically. RESULTS: The clamping time tended to be longer in dogs with early systolic retrograde coronary flow. Neutrophil infiltration was observed in the myocardium of dogs without systolic retrograde flow (n = 9); hemorrhage was rarely detectable and the myocardium maintained a bundle form. However, the bundle form of the myocardium became rough, and the severity of the incidence of hemorrhage tended to increase as the ratio of the diastolic coronary flow velocity to systolic velocity (DSVR) decreased. Vacuolar degeneration of the myocardium was also observed in hearts with a relatively low DSVR. In the group with systolic retrograde flow (n = 3), hearts were characterized by coagulation necrosis, marked vacuolar degeneration of the myocardium and diffusely distributed red cells in the intermyocytes. Systolic antegrade flow velocity was much reduced in this group, resulting in a markedly increased DSVR. These findings appeared to be related to severe myocardial damage. CONCLUSIONS: Coronary flow velocity patterns immediately after successful reperfusion appear to reflect the pathologic characteristics of the reperfused myocardium in dogs with AMI.

Animals↗
PubMed1998

Tissue inhibitors of metalloproteinases level and collagenase activity in gingival crevicular fluid: the relevance to periodontal diseases.

OBJECTIVES: To provide an overall assessment of levels of tissue inhibitors of metalloproteinases (TIMPs), collagenase activities, and of immuno-reactivities for matrix metalloproteinases (MMP)-1 and -8 in gingival crevicular fluid (GCF) obtained from healthy subjects, and gingivitis and periodontitis patients, and to analyse the relationships between periodontal tissue destruction and the GCF components in periodontal diseases by principal component analysis. MATERIALS AND METHODS: GCF was sampled with sterile paper strips from 10 gingivitis and 11 periodontitis patients. Ten volunteers served as clinically healthy controls. TIMP-1 and -2 protein amounts in GCF were measured by ELISA, and active and APMA-activatable collagenase activities were determined by functional assays using image-analysis after SDS-PAGE. RESULTS: GCF TIMP-1 level and both active and latent collagenase activities were significantly higher in the diseased groups than in the healthy group. TIMP-2 was detectable in only 29% of all subjects (mean: 2.06 ng). Western blot analysis showed that MMP-8 was the major interstitial collagenase in the GCF of the diseased groups. Principal component analysis using clinical parameters and the GCF components has indicated components one to three account for 87% of total variation when evaluating the relevance of their measurements to periodontal diseases. CONCLUSIONS: We conducted the functional and immunological characterization of MMPs and TIMPs in the GCF of periodontally diseased patients. Principal component analysis indicated components one to three explaining 87% of total variation, and further suggested that higher collagenase activity (especially in active collagenase) would be an important marker in evaluating the pathogenesis of periodontitis. Consequently, these observations may have significant therapeutic and diagnostic implications.

Adult↗
PubMed1998

Heterotopic polyodontia in a cynomolgus monkey.

A case of heterotopic polyodontia was detected in a 6-year-old male laboratory cynomolgus monkey. A heterotopic tooth had erupted through the right maxillofacial area at the side of the nose, with a crustated surface. Macroscopically, the tooth was not connected with the right parotid. Radiography and histopathology of the transverse section of the lesion showed almost normal propriodentium containing alveolar bone and partial continuity with the maxillary bone. We believe this is the first case description of heterotopic polyodontia in a monkey.

Animals↗
PubMed1998

[A longitudinal cohort study on the relation between physical condition and masticatory ability in the elderly].

The present study was conducted to determine the relation between physical condition and masticatory ability. The subjects were residents over 65 years old living in three different areas in Sagae City. The physical conditions assessed were height, weight, rate of body fat, grip strength, and bone mineral density. Masticatory ability was evaluated by the test jelly method. The results were as follows: 1) There was a difference in physical condition among subjects from the three residential areas. 2) For males, the group who maintained their masticatory ability exhibited better physical condition than those who did not. As for females, however, the physical condition was more strongly affected by age than masticatory ability.

Aged↗
PubMed1998

[A clinical study of decreased bone density in the patients treated with long-term luteinizing hormone releasing hormone analogue (LHRH-a)--the risk of iatrogenic osteoporosis due to treatment of carcinoma of prostate].

BACKGROUND: It is well known that androgens play an important role in bone metabolism and male hypogonadism induce osteoporosis. Luteinizing hormone-releasing hormone analogue (LHRH-a) which is essential for conservative therapy of prostatic carcinoma (CaP) ultimately reduces circulating testosterone to castration levels. The purpose of this study was to determine the risk of decrease of bone mineral density in men receiving LHRH-a for CaP. PATIENTS AND METHODS: Fifty-three man with CaP aged 63 to 95 years (mean 75.5 years) were included in this study. Seven patients received LHRH-a with estrogen drug, forty-six patients received LHRH-a with or without anti androgen drug. To estimate patient's bone density we use the second metacarpal bone density using a microdensitometry method. RESULTS: Blood level of sex hormone of the forty-six patients who were received LHRH-a without estrogen, was the same as that of castration. Patients who were treated more than twelve months had less bone density than patients who were treated less than eleven months. As the duration of medical castration period was prolonged, patients bone density were reduced. Whereas seven patients who received estrogen drug did not find a decrease of bone density regardless of duration of treatment period. CONCLUSIONS: Hypogonadism induced LHRH-a also reduce bone density, so there is a risk of iatrogenic osteoporosis caused by therapy for CaP with LHRH-a. Patients with osteoporosis easily suffer from a much complicated and pernicious bone fracture, so we should measure bone density of male patients same as female treated with LHRH-a for a long-term.

Aged↗
PubMed1997

Inhibition of proliferation of MCF-7 breast cancer cells by a blocker of Ca(2+)-permeable channel.

In MCF-7 breast cancer cells, insulin-like growth factor-1 (IGF-1) increased the calcium-permeability of the cells by activating a voltage-independent calcium-permeable channel. IGF-1 also induced oscillatory elevation of cytoplasmic free calcium concentration in these cells. An anti-allergic compound, tranilast, reduced the calcium-permeability augmented by IGF-1 in a dose-dependent manner and blocked the oscillatory elevation of cytoplasmic free calcium concentration. Tranilast did not affect early intracellular signals activated by IGF-1, including receptor autophosphorylation, activations of Ras, mitogen-activated protein kinase and phosphatidylinositol 3-kinase. Tranilast inhibited increases in [3H]-thymidine incorporation, DNA content and cell number induced by IGF-1. The ID50 for [3H]-thymidine incorporation and DNA content were about 10 microM. The inhibitory effect of tranilast was reversible, and cell viability was not affected. Treatment with tranilast increased the number of cells in the G1 phase suggesting that this compound induced G1 arrest. Tranilast also reduced the phosphorylation of the retinoblastoma protein. These results indicate that tranilast inhibits the IGF-1-induced cell growth in MCF-7 cells by blocking calcium entry.

Breast Neoplasms↗
PubMed1997

Antibacterial activity of quinolones against coagulase-negative staphylococci and the quinolone resistance-determining region of the gyrA genes from six species.

Antibacterial activity of quinolones against three species of coagulase-negative staphylococci was investigated. Tosufloxacin and sparfloxacin exhibited potent activities against Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus saprophyticus compared with other quinolones tested. From the analysis of the DNA sequence in the quinolone resistance-determining region (QRDR), greater than 80% homology was recognized in coagulase-negative staphylococci. A series residue was conserved in all six species at the position corresponding to position 84 in Staphylococcus aureus.

Anti-Infective Agents↗
PubMed1997

Perineal muscles and their innervation: metabolic and functional significance of the motor unit.

Cross-sectional areas and succinate dehydrogenase (SDH) activities of muscle fibers in the rat levator ani (LA) and bulbocavernosus (BC) were determined and compared with those of the soleus (SOL) and superficial (TAs) and deep (TAd) portions of the tibialis anterior (TA). In addition, cell body sizes and SDH activities of spinal motoneurons innervating the LA and BC were examined. Histochemical myofibrillar adenosine triphosphatase (mATPase) staining reactions following alkaline and acid preincubations revealed that all the muscle fibers in the LA and BC were type IIB. Gel electrophoresis, however, showed that the LA and BC contained 2.9 and 2.4% type IIx myosin heavy chain (MHC) isoform, respectively. Immunohistochemical analyses using MHC antibodies showed that the muscle fibers in the LA and BC had types IIx / IIa (approximately 3%) or type IIb MHC isoforms. The mean fiber cross-sectional areas in the LA and BC were significantly smaller than those in the SOL, TAs, or TAd. The mean fiber SDH activities in the LA and BC were significantly lower than those in the SOL or TAd, and similar to TAs. The population of alpha motoneurons innervating the LA and BC had similar SDH activities, irrespective of their cell body sizes. These data indicate that the LA and BC are comprised of a relatively homogeneous population of small, fast and low oxidative fibers innervated by a relatively homogeneous population of spinal motoneurons. These characteristics of the muscle fibers and motoneurons are consistent with their function in short, high-intensity activities.

Animals↗
PubMed1997

[A study of the clinical effect of hormone replacement therapy for patients with stress incontinence].

BACKGROUND: Our purpose was to clarify the effect of hormone replacement therapy (H.R.T.) for patients with stress incontinence. METHODS: We investigated 25 postmenopausal women, age 54-73 years, with a leakage volume is less than 15 g/day. In this study 0.625 mg of conjugated estrogen and 2.5 mg of medroxyprogesterone acetate were administrated for a total of 4 months. A clinical evaluation, measurement of volume of leakage per day and urodynamic evaluation (urethral pressure profile) were performed three times at pre administration, and at 2 months and 4 months after administration. RESULTS: Five of the 24 patients (20.8%) were improved significantly both clinically and urodynamically. Six patients (25.0%) improved clinically, and two patients (8.3%) improved urodynamically, the remaining 11 patients (45.8%) showed no change. Side effects occurred in eight cases. In one patient, it was necessary to stop administration due to severe irregular genital bleeding and leukorrhea, and in one patient the dosage was reduced due to swelling of breasts. The side effects of swelling of breasts and genital bleeding were relatively mild in the remaining six patients and they could continue H.R.T. administration. CONCLUSIONS: These results suggest that H.R.T. for patients with stress incontinence is not necessarily superior to the other non surgical methods. However, it may provide an alternative treatment method for incontinence.

Aged↗
PubMed1997

Influence of two weeks of non-weight bearing on rat soleus motoneurons and muscle fibers.

BACKGROUND: Chronic unloading of the hindlimbs of rats results in atrophy and a shift in the metabolic and mechanical properties of the soleus muscle a predominantly slow postural muscle, towards those observed in faster muscles. HYPOTHESIS: We hypothesized that the spinal motoneurons innervating the soleus muscle would also atrophy and show adaptations in their metabolic properties following a period of unloading. METHODS: For 2 weeks, 10-week-old male Wistar rats were hindlimb suspended and the mean soma size and succinate dehydrogenase activity of motoneurons innervating the soleus muscle were examined. Retrograde labeling with nuclear yellow injected in the soleus muscle was used to identify the soleus motor pool. The mean fiber size and fiber type distribution from a central region of each soleus muscle was determined. RESULTS: The soma size distribution, mean soma cross-sectional area and mean succinate dehydrogenase activity of motoneurons in the soleus motor pool were similar in control and hindlimb suspended rats. In contrast, compared to control the mean fiber size of each fiber type and the percentages of Type I fibers decreased and of Type IIa fibers increased in the soleus muscle following hindlimb suspension. CONCLUSIONS: The results indicate that significant alterations in the phenotype and size of muscle fibers can occur without concomitant adaptations in the innervating motoneurons usually associated with motor unit types (i.e., soma size and oxidative capacity).

Analysis of Variance↗
PubMed1997

[Role of TCR V alpha 24 J alpha Q+ T cells in autoimmune diseases].

We investigated the role of T cell receptor (TCR) V alpha 24+ T cells in the pathogenesis of systemic sclerosis (SSc) and systemic lupus erythematosus (SLE). The invariant V alpha 24 J alpha Q was expanded and comprised 50-90% of the total V alpha 24 in healthy individuals. In contrast, patients with SSc and SLE showed the selective reduction of the invariant V alpha 24 J alpha Q with oligoclonal expansion of V alpha 24 TCR other than V alpha 24 J alpha Q. Because human V alpha 24 J alpha Q TCR is analogous to murine invariant V alpha 14 J alpha 281 TCR which is the major genotype of NK T cells, these results suggest that the selective reduction of T cells with invariant V alpha 24 J alpha Q TCR might play an important role of the generation of autoreactive T cells including T cells bearing other V alpha 24 TCR in autoimmune disease patients.

Amino Acid Sequence↗
PubMed1996

Phosphorylation of chromogranin A and catecholamine secretion stimulated by elevation of intracellular Ca2+ in cultured bovine adrenal medullary cells.

We have recently isolated a new endogenous substrate of 70 kDa for Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) from bovine adrenal medullary cells (Yanagihara, N., Toyohira, Y., Yamamoto, H., Ohta, Y., Tsutsui, M., Miyamoto, E., and Izumi, F. (1994) Mol. Pharmacol. 46, 423-430). Here we report the sequence analysis of the 70-kDa protein and examine its phosphorylation by various protein kinases in vitro and by depolarization of the cultured cells. Protein sequencing and immunoblotting revealed that the 70-kDa protein is chromogranin A (CgA) or a closely related protein. Partially purified CgA was phosphorylated by cyclic AMP-dependent protein kinase and protein kinase C as well as CaM kinase II. Tryptic phosphopeptide mapping patterns of CgA differed among these protein kinases. In 32P-labeled bovine adrenal medullary cells, 56 mM K+ increased the phosphorylation of CgA and catecholamine secretion in similar time- and concentration-dependent manners, both of which were inhibited by 20 mM MgSO4, an inhibitor of voltage-dependent Ca2+ channels. These findings suggest that CgA serves as a substrate for several multifunctional protein kinases and that the elevation of the intracellular Ca2+ stimulates the phosphorylation of CgA associated with catecholamine secretion in cultured adrenal medullary cells.

Adrenal Medulla↗
PubMed1996

The effects of 2,5-hexanedione and acrylamide on myosin heavy chain isoforms of slow and fast skeletal muscles of the rat.

We examined the effects of 2,5-hexanedione (2,5-HD) and acrylamide (ACR) on the muscle fiber types and myosin heavy chain (MHC) isoform composition of the slow-twitch soleus and fast-twitch plantaris muscles of rats. We employed two differently designed experiments with respect to the dosage levels and treatment periods for developing clinical neuropathies. When male Wistar rats were subcutaneously injected with 4.5 mmol of 2,5-HD/kg or 0.4 mmol of ACR/kg, 5 days a week, they developed paralysis of the hindlimbs in 4 weeks (high-dosage experiment). When they were subcutaneously injected with 3.5 mmol of 2,5-HD/kg or 0.35 mmol of ACR/kg, 5 days a week, paralysis of the hindlimbs did not develop until 6 weeks (low-dosage experiment). We examined mainly the rats treated with the neurotoxicants for 4 and 8 weeks in the high-and low-dosage experiments, respectively. Significant decreases in the maximum motor conduction velocity of the sciatic nerves were observed in the hindlimbs of the rats in both experiments. The weights of the soleus and plantaris muscles were significantly reduced in the 2,5-HD-treated rats in both experiments, while in the ACR-treated rats, the weights of both muscles decreased only in the low-dosage experiment. We could not detect any changes in the fiber type composition of the muscles by any of the treatments. However, biochemical analysis revealed decreases in the values (percentage) of the relative amounts of fast-type MHC IIa and IIb isoforms to total MHC isoforms in the 2,5-HD-treated rats, but not in the ACR-treated rats in the high-dosage experiment. In contrast, significant differences in the relative amounts of MHC isoforms were not observed after administration of the low dosage of 2,5-HD. These results suggest that 2,5-HD preferentially disorders the muscle fibers which contain the MHC II isoform. These effects may occur only after the relatively acute intoxication of 2,5-HD at a high dosage.

Acrylamide↗
PubMed1996

Bilateral giant myelolipoma in the adrenal of a cotton-top tamarin (Saguinus oedipus).

A rare case of bilateral adrenal myelolipomas in a female cotton-top tamarin is reported. Large bilateral masses in the adrenal glands were composed of mature adipose cells containing varying amounts of hematopoietic cells of the myeloid, erythroid, and megakaryocytic series. The gross and histologic features of this case closely resemble human "giant" adrenal myelolipomas.

Adrenal Cortex↗
PubMed1996

[A case of ectopic familial pheochromocytoma].

This is a report of the occurrence of familial ectopic pheochromocytoma in two brothers, whose father had bilateral adrenal pheochromocytoma. Both brother complained of hypertension. In the first case, a 22-year-old man presented with much higher than normal norepinephrine. Abdominal CT and chest CT scanning and 123I-MIBG scintigraphy revealed an extraadrenal tumor in the chest on the bilateral adrenal grands. Bilateral adrenectomy was performed. In the second case, the 20-year-old brother was found to have an abdominal mass that was diagnosed as ectopic pheochromocytoma originating in the intra-abdominal paraaorta according to abdominal CT scanning and 131I-MIBG scintigraphy. The tumor was resected.

Abdominal Neoplasms↗
PubMed1996

[Clinical study of Silver Lubricath Foley catheter].

We evaluated the Silver Lubricath Foley Catheter (silver catheter) coated with silver and hydrogel developed to prevent urinary infection, in comparison with the silicone-coated catheter (silicone catheter). Twelve patients ranging from 71 to 95 years of age (median age, 82 years) were catheterized and the 16 of 18F catheter was replaced every 2 weeks. They answered a questionnaire which included inquiry about the treatment with urinary catheter. Because of less leakage and discomfort to the urethra, the silver catheter had advantages over the silicone catheter. The risk of bacteriuria after 14 days of catheterization was not significantly different between the two types of catheter. Scanning electron microscopic analysis revealed that bacterial biofilm developed on the inner surface of both catheters after 14 days of catheterization. On the other hand, the amount of bacterial biofilm on the outer surface of a silver catheter was less than that on the outer surface of a silicone catheter.

Aged↗
PubMed1996

[A case of penile cancer treated with combination of chemotherapy, radiation and radical operation].

A 60-year-old [correction of 68] male was referred to our hospital because of a penile tumor with necrosis. Pathological examination of the penile tumor and superficial inguinal lymph nodes in biopsy revealed well differentiated squamous cell carcinoma (SCC) and the SCC tumor marker was elevated. TNM classification was T2, N2, M0 according to findings obtained by computed tomography (CT) and magnetic resonance imaging (MRI). We diagnosed the tumor inoperable radically and administered 10 mg peplomycin once a week for 10 weeks intravenously. The SCC marker level was not reduced and the tumor was not changed on MRI. Then, we performed combined pirarubicin treatment and radiotherapy. The patient received linac radiotherapy between 40 Gy/4 weeks/20 fractions. Pirarubicin, 10 mg/m2, was administered once a week for 4 weeks during irradiation intravenously. After the combined therapy, the SCC marked level was reduced to the normal range and the tumor was reduced. We performed radical operation. Pathological diagnosis revealed no viable tumor cells. The patient was alive with no evidence of disease a year later. This combined therapy is suggested to be useful.

Antibiotics, Antineoplastic↗