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Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 811 records · Page 45Linked to original sources
PubMed1994

Association of a nocturnal rise in plasma alpha-atrial natriuretic peptide and reversed diurnal blood pressure rhythm in hospitalized normotensive subjects with non-insulin dependent diabetes mellitus.

Diurnal changes in plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA) and plasma aldosterone as related to those in blood pressure (BP) were studied under hospital conditions in 18 diabetic subjects without proteinuria and 8 age-matched control subjects. Of 18 diabetic subjects, 10 had a normal diurnal BP rhythm with the peak value in the afternoon (group 1) and 8 had a reversed BP rhythm with the peak value during the night (group 2). Autonomic dysfunction estimated by measuring orthostatic BP and heart-rate changes and beat-to-beat heart-rate variations was more pronounced in group 2 than in group 1. Fasting plasma glucose and HbA1c were similarly high in both diabetic groups. Group 1 showed modestly elevated mean 24-h MBP and plasma ANP levels, modestly low mean 24-h PRA and plasma aldosterone levels, and a lack of diurnal ANP changes similar to that in controls. Group 2 showed markedly elevated mean 24-h BP and plasma ANP levels, markedly low mean 24-h PRA and plasma aldosterone levels, and nocturnal rises in plasma ANP and BP. PRA and plasma aldosterone exhibited circadian rhythms with their peak values found in the early morning in all three groups. The daytime/overnight excretion ratios of sodium and water were normal in group 1 and low in group 2. These results indicate that diurnal changes in plasma ANP, PRA and plasma aldosterone are altered in diabetic subjects with normal and reversed diurnal BP rhythms, predominantly in the latter.

Aged↗
PubMed1994

[Changes in serum lipid and lipoproteins in alloxan-diabetic rats--studies for one year].

Alloxan-diabetic rats were kept on an ordinary or 0.25% cholesterol supplemented diet for up to 12 months, and changes in the serum lipid and lipoprotein levels were examined. The diabetic rats showed IRI levels of 3-5 IU/ml, which were 1/5-1/10 that of the normal rats, and about 10 times higher serum glucose levels than the normal rats. The diabetic rats consumed 1.5-2 fold amounts of diet but their body weights were almost constant. The diabetic rats showed marked hyperlipidemia, especially in the cholesterol and triglyceride levels. The phospholipid level also increased but for a lesser extent and the c/p ratio increased. The serum lipoprotein levels increased in the diabetic rats, 5-10 times in the ordinary diet fed groups and 10-20 times in the cholesterol diet fed groups. Chylomicron, VLDL, IDL and LDL increased but HDL decreased. These changes were more significant in the diabetic rats fed the cholesterol diet. The triglyceride levels in the lipoprotein fractions increased in the diabetic rats, but the increase in cholesterol was more significant and the relative composition ratios of triglyceride decreased. The composition ratios of phospholipids, however, remained almost constant in all the lipoprotein fractions. The increase in IDL, especially cholesterol in the IDL fraction, was remarkable in the diabetic rats. The responsiveness of the diabetic rat VLDL to lipoprotein lipase (release of free fatty acids) was less than a half of that of the normal rat VLDL. In conclusion, the diabetic rats showed an increase in triglyceride but more significant increase in cholesterol in the lipoprotein fractions. These changes in serum lipid and lipoprotein levels and compositions appeared as early as 3 months after the alloxan injection and lasted for 12 months without any progress in the disturbance.

Alloxan↗
PubMed1994

Electrocochleography in experimental endolymphatic hydrops.

This study investigated whether dominant negative summating potential (DNSP) is absent at all stages of induced hydrops development, including the early stages of hydrops formations. Electrocochleography (ECoG) was done 3 days to 20 weeks after obliteration of the endolymphatic sac in guinea pigs, by electrodes attached to the cochlear bony wall on the scala vestibuli of the basal turn. DNSP was noticed only during the early stages of endolymphatic hydrops formation, before hydrops was fully developed. There was no DNSP when the distension of Reissner's membrane was marked. Increased endolymphatic pressure and/or changes in biochemical composition were thought to be the causes of DNSP.

Action Potentials↗
PubMed1994

Effect of atmospheric pressure on hearing in normal subjects.

Hearing is assumed to be altered during or immediately after a change in atmospheric pressure, although this has not been tested experimentally. We used a soundproof pressure chamber to examine the effect of alterations in atmospheric pressure on hearing in 26 normal healthy subjects. The subjects were placed in the soundproof pressure chamber in a supine position and instructed to actively equilibrate middle ear pressure or to abstain from doing so. When the pressure was changed to +/- 500 mmH2O at 33 mmH2O/s the results were as follows: When subjects did not equilibrate middle ear pressure, air conduction at low frequency tones increased more than bone conduction. The degree of deterioration in hearing was greater when the chamber pressure was increased (descent) than where pressure was decreased (ascent). When the subjects equilibrated middle ear pressure, little change in the levels of air or bone conduction was observed. Most of the deterioration in bone conduction was considered to reflect functional loss due to increased stiffness and damping of the sound transmission mechanism.

Adult↗
PubMed1994

Effect of light intensity on polymerization of light-cured composite resins.

The depths of cure and the distributions of degree of conversion (DC), polymerization conversion (PC) and percent pendant double bonds (PDB) of light-cured composite resins cured under various intensities of light were investigated. When the total amount of exposure, represented by the product of the light intensity and the irradiation time, was kept constant, each of the depth of cure and the distributions of DC, PC and PDB were the same for each material regardless of the light intensity and irradiation time. The depth of cure could be expressed as a logarithmic function of the total amount of exposure. From regression analysis, the attenuation coefficient and the critical total amount of exposure capable of initiating polymerization of each composite resin could be determined.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1994

Development of atherosclerosis in alloxan diabetic rats.

Rats with alloxan-induced diabetes developed severe atherosclerotic lesions when they were maintained on a 0.25% cholesterol diet for one year. The atheromatous changes developed at the aortic arch, appeared as early as 3 months after the start of the experiment, and increased thereafter. The diabetic rats also developed atherosclerosis when they were fed standard rat chow, but the area of the atheromatous lesion was about one tenth of that in rats fed the high-cholesterol diet. Normal rats did not develop atherosclerosis even when fed the high-cholesterol diet for one year. The alloxan diabetic rats showed no increase in body weight, but developed serum glucose levels as high as 600-800 mg/dl as well as high serum cholesterol levels and lower serum HDL-cholesterol levels. The development of atherosclerosis in these rats was significantly related to an increase in the serum cholesterol/phospholipid ratio, the atherogenic index (TC-HDLC/HDLC), and the serum total cholesterol level, but was not related to the serum glucose, HDL-cholesterol, triglyceride, or lipid peroxide levels. These relationships were found as early as B-16 weeks after the start of the experiment. These data suggest that the serum cholesterol/phospholipid ratio, the atherogenic index, and the total cholesterol level are important risk factors for the development of atherosclerosis in rats with alloxan diabetes.

Animals↗
PubMed1994

Decreased susceptibility of glycated very low density lipoproteins to lipoprotein lipase in vitro and prevention by glutathione.

In vitro glycation of very low density lipoprotein (VLDL) reduced the susceptibility to lipoprotein lipase (LPL) as the level of glycation increased. Addition of reduced glutathione to an incubation medium of serum and glucose interfered with glycation of serum proteins when the concentration of reduced glutathione was higher than 10 mM. At concentrations higher than 25 mM, it also significantly prevented the glycation induced reduction of fatty acid releases from VLDL by LPL. There were no such effects on glycation of serum protein and the fatty acid release from the addition of aminoguanidine. By contrast, addition of D-lysine enhanced glycation of serum proteins by glucose and further decreased fatty acid release from VLDL by LPL. From these results, it is suggested that glycation of VLDL decreases the susceptibility of VLDL to LPL. Delayed catabolism of VLDL in diabetic patients is considered partly caused by glycation of apoproteins, which renders VLDL less sensitive to LPL, in addition to the decreased LPL activity in diabetes mellitus.

Catalysis↗
PubMed1994

[Adult Wilms's tumor with histologically dissisimilar lung metastasis].

A 41-year-old man incidentally found to have a right renal and left large lung tumor in the course of screening for liver dysfunction was admitted to our hospital. Needle biopsy of each tumors revealed histologically renal cell carcinoma and pulmonary blastoma. The renal tumor grew rapidly and soon he died of DIC. Autopsy was performed and the final diagnosis was adult Wilms' tumor and its metastasis to the lung. Histological findings of each large tumors showed different histologic pattern. The renal tumor revealed diffuse nephroblastic subtype and the lung tumor showed epitherial type. This is a rare case of Wilms' tumor in terms of its adult onset and different histologic pattern between the primary tumor and its metastatic lesion.

Adult↗
PubMed1994

Relationship between plasma levels of type II phospholipase A2, PAF acetylhydrolase, endothelin-1, and thrombomodulin in patients with infected burns.

The relations between type II phospholipase A2 (PLA2) and PAF acetylhydrolase (PAFAH) levels and those of endothelin-1 (ET-1) and thrombomodulin (TM) were examined in samples containing the maximum amount of TNF-alpha detected over the clinical course for each patient with burn wound infection. The study included 23 patients with a total burn surface area of > 20%. Plasma levels of tumor necrosis factor-alpha (TNF-alpha), type II PLA2, PAFAH, TM, and ET-1 were 174.1 +/- 239.5 pg/ml, 229.5 +/- 190.8 ng/ml, 22.68 +/- 7.07 nmol/min per ml, 6.62 +/- 2.78 ng/ml, and 7.45 +/- 2.99 pg/ml, respectively. There were significant correlations between plasma levels of type II PLA2 and TM (r = 0.767, p < 0.0001), between PAFAH and TM (r = 0.542, p = 0.0076), between type II PLA2 and ET-1 (r = 0.688, p = 0.0003), and between PAFAH and ET-1 (r = 0.516, p = 0.0117). These results suggest that the increases in plasma type II PLA2 and PAFAH are related to vascular endothelial disorders in patients with infected burns.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1994

[Effectiveness of oral treatment with terbinafine in a guinea pig model of tinea pedis].

In order to perform a preclinical evaluation of effectiveness of oral terbinafine (TBF) in tinea pedis, an animal model was produced using guinea pigs by experimentally infecting the plantar skin with Trichophyton mentagrophytes. TBF was administered orally to groups of the infected guinea pigs once-a-day for 4 consecutive weeks. The therapeutic efficacy was assessed on the basis of recovery of fungal cultures from the plantar skin. The group of guinea pigs treated with 12.5 mg/kg/day of TBF resulted in complete cure. The animal group treated with 3.13 mg/kg/day of TBF showed significantly better mycological response to the therapy than the group treated with 12.5 mg/kg/day of griseofulvin. These results suggest clinical usefulness of oral TBF for the treatment of tinea pedis.

Administration, Oral↗
PubMed1994

[A study on effectiveness of treatment and prevention of relapse using topical administration of terbinafine in a guinea pig model for tinea pedis].

The effectiveness of topical terbinafine (TBF) to tinea pedis was evaluated an animal model in which guinea pigs were experimentally infected through their planta pedis with Trichophyton mentagrophytes, then a 1% TBF or butenafine (BTF) cream was administered topically once daily for 4 consecutive weeks. The therapeutic efficacy was assessed on the basis of recovery of fungal cultures from the planta pedis. The cured guinea pigs were reared in a clean environment that protected the animals from reinfection. The dermal tissues were cultured 2, 4, and 8 weeks post-treatment to examine for relapse of tinea. Complete cure was achieved after 4 weeks of administration of TBF or BTF cream. In animals receiving 4 weeks of treatment with TBF, relapse was not observed up to 8 weeks after the termination of treatment. In animals treated with BTF for 4 weeks, while no relapse occurred 4 weeks after cessation of the treatment, relapse was detected in 2 out of 10 feet at 8 weeks after the termination of treatment. These results suggest that topical TBF is effective in curing the infection and in preventing relapse in a guinea pig model of tinea pedis.

Administration, Topical↗
PubMed1994

[Association of cell cycle and protein kinase C with the expression of cytoskeletal protein in cultured rat mesangial cells].

We conducted a study to investigate whether expression of the contractile proteins in cultured rat mesangial cells (MC) was associated with the cell cycle and protein kinase C (PKC). When growth-arrested MC were stimulated with 100 nM phorbol myristate acetate (PMA) for 24 hours, an increased expression of smooth muscle alpha-actin and vimentin was detected by immunocytochemistry. A proportion of the S- and G2/M-phase in MC was increased in accordance with the enhanced expression of contractile proteins on flow cytometry. Immunoblot analysis revealed that 100 nM PMA stimulated expression of alpha-actin and vimentin as a single band. These results indicate that expression of contractile proteins, such as alpha-actin and vimentin, is dependent on the cell cycle and PKC, suggesting a phenotypic change in which MC assume smooth muscle cell characteristics.

Animals↗
PubMed1994

[Changes in luminal diameter of internal thoracic arteries five years after coronary artery bypass grafting].

Five years after coronary artery bypass grafting, 23 internal thoracic arteries (ITAs) were reexamined angiographically, and their luminal diameters were compared with those of one month after the operation. Proximal diameter, just below the subclavian artery, and distal diameter, just above the anstomosis, were measured. One month after surgery, these were 2.38 +/- 0.48 mm and 1.69 +/- 0.39 mm, respectively. After five years, the proximal diameter had not changed significantly (2.48 +/- 0.47 mm), but the distal diameter had increased to 1.96 +/- 0.58 mm (p < 0.05). Especially when there was no competitive flow with the ITA, the distal diameter showed a marked increase from 1.80 +/- 0.35 mm to 2.27 +/- 0.42 mm (p < 0.01). Twelve ITAs were grafted to coronary arteries having less than critical stenosis, and five of them showed distal narrowing or so-called string sign after five years. This seemed to be a form or physiological atrophy resulting from competitive flow, and the patients had no anginal pain in spite of their poor ITA runoff. When coronary artery stenosis is less than 75%, a choice is difficult between an ITA or a saphenous vein graft. We think that the graft must be selected considering the possibility of stenosis progression, if the jeopardized area is important for the patient. An ITA graft would be advisable in such cases.

Aged↗
PubMed1994

The relationship between vasopressin and endolymphatic hydrops in the guinea pig.

Clinical studies have shown that plasma vasopressin level is significantly elevated in patients with Meniere's disease. Other reports indicated that histamine induced a very quick and high elevation of vasopressin level and caused nystagmus in experimentally produced endolymphatic hydrops. We became interested in further investigating the details of this relationship by studying the effect of experimental endolymphatic hydrops and histamine upon plasma vasopressin level in the guinea pig. The results are as follows: 1) Histamine increased the plasma vasopressin level in normal guinea pigs. 2) There was no statistically significant difference in the plasma vasopressin level between the hydrops model and normal guinea pigs. 3) Histamine increased the plasma vasopressin level more in the hydrops model group than in normals. 4) Plasma vasopressin level was elevated in the vertiginous model caused by inner ear anesthesia. Our results support those of clinical investigators who reported that the plasma vasopressin level was elevated more in the Meniere's disease group than any other equilibrium disorder group. It is possible that vasopressin is in someway involved in the development of endolymphatic hydrops.

Animals↗
PubMed1994

Establishment and characterization of an immortalized bovine glomerular endothelial cell line.

Bovine subcultures (second passage) of glomerular endothelial cells (GEN) isolated from one-year-old kidney were successfully transfected by recombinant plasmids containing the simian virus (SV)-40 T antigen (Tag) using a lipofectin-mediated procedure. One cell clone was selected, propagated and characterized. This clone can be grown in RPMI 1640 medium supplemented with 10% fetal calf serum. The advantage of this cell line is the cultivation of bovine GEN without the addition of fibroblast growth factor or a coating of fibronectin or gelatin on the culture plate. More than 80 passages were achieved and the doubling time was 32 h. The Tag was easily identified in transfected-GEN by indirect immunofluorescence. These cells weakly expressed factor VIII-related antigen, slightly took up acetylated-low density lipoprotein and secreted a detectable amount of angiotensin-converting enzyme. Immunocytochemical staining for UAE-1 was also positive. Moreover, oncoproteins, such as Ki-67 and p53, were expressed in these cells. Cell cycle analysis by flow cytometry revealed that the percentages of G1, S, and G2/M stages in cycling transfected-GEN culture in RPMI 1640 medium supplemented with 10% fetal calf serum were 34%, 52.9%, and 13.1%, respectively. The conditioned medium from confluent transfected-GEN stimulated [3H]thymidine incorporation into glomerular mesangial cells. This cell line may provide a useful tool for examining modulators of mesangial cell growth. Thus this cell line is the first immortalized bovine GEN that retain the morphologic, phenotypic, and functional characteristics of bovine GEN.

Animals↗
PubMed1994

Relationships between plasma levels of type-II phospholipase A2, PAF-acetylhydrolase, leukotriene B4, complements, endothelin-1, and thrombomodulin in patients with sepsis.

We determined the plasma levels of type-II phospholipase A2 (type II PLA2), platelet-activating factor acetylhydrolase (PAFAH) leukotriene B4 (LTB4) and of several complements (C3a, C4a, and C5a), which are considered to be among the cytokines and eicosanoids involved in vascular endothelial disorders and that vary in concentration during sepsis. We investigated the relationship between those levels and those of ET-1 and TM levels in plasma. Plasma levels of type II PLA2, PAFAH, LTB4, C3a, C4a, ET-1, and TM at the time that sepsis was diagnosed in 30 patients were 218.3 +/- 179.9 ng/ml, 23.92 +/- 9.66 nmol/min/ml, 90.35 +/- 31.49 pg/ml, 838.73 +/- 2.30 pg/ml, 1951.46 +/- 1697.78 pg/ml, 6.98 +/- 4.08 pg/ml and 7.80 +/- 3.34 ng/ml, respectively. The C5a plasma level was below the limit of detection in all cases. There were significant correlations between type II PLA2 and ET-1 plasma levels (r = 0.39, p = 0.032) and C3a and ET-1 plasma levels (r = 0.60, p = 0.03). There were also significant correlations between type II PLA2 and TM levels in plasma (r = 0.76, p = 0.0017), PAFAH and TM plasma levels (r = 0.53, p = 0.037), LTB4 and TM plasma levels (r = 0.46, p = 0.016) and C4a and TM plasma levels (r = 0.58, p = 0.037). Results suggest that the elevation of type II PLA2, PAFAH, LTB4 and complement in plasma is involved in vascular endothelial disorders in patients with sepsis.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1994

Preliminary results of bladder-preserving therapy with definitive radiotherapy and intraarterial infusion of chemotherapy.

PURPOSE: For management of muscle-invading bladder cancer (clinical stages T2 to T4), combined treatment of definitive radiotherapy (RT) and intraarterial (IA) administration of chemotherapy was carried out for local cure and bladder preservation. METHODS AND MATERIALS: Between 1987 and 1990, a pilot study (Protocol-1) was initially conducted in 16 patients to investigate the efficacy of chemoradiotherapy where RT was combined with TURB and continuous IA infusion of cisplatin. We then performed a regimen of possible bladder-preservation treatment (Protocol-2) in which 19 patients were treated with combination of TURB, full-dose RT and one-shot IA infusion of cisplatin and methotrexate. In RT small pelvis irradiation was performed with x-rays followed by proton beam boost irradiation to the original tumor site. RESULTS: Among patients treated on Protocol-1, a tumor-free bladder was observed in 50% (2/4) after 50-76 Gy but only 8% (1/14) after 30-40 Gy. In this regimen, planned cystectomy was performed in 10 patients and 13 patients (81%) are alive. Among 19 patients treated on Protocol-2, 17 patients (89%) are alive and 13 patients (68%) retained intact bladders without any recurrence. There were 3 cystectomies performed because of persistent tumors. Using a conformal mode of proton beam irradiation, a total dose of 60-80 Gy was safely administered with acceptable morbidities. CONCLUSION: In the light of good complete response and survival rates achieved in the patients treated on Protocol-2, the combined treatment of definitive RT and IA administration of chemotherapy is considered as an effective bladder-preserving strategy.

Aged↗