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Biomedical subjects

Y Okuda

Publications and source records attributed to Y Okuda.

At least 289 records · Page 16Linked to original sources
PubMed1992

High glucose and hyperosmolarity increase platelet-derived growth factor mRNA levels in cultured human vascular endothelial cells.

We investigated the effects of high glucose and hyperosmolality on platelet-derived growth factor (PDGF) production and PDGF-B chain mRNA levels in cultured human umbilical vein endothelial cells. Under an excess of ambient glucose (13.8 and 27.5mM) and a hyperosmolar condition (22.0mOsm/L with mannitol), PDGF concentrations in the culture medium were both significantly increased (10.3 +/- 6.0%, 36.2 +/- 7.2%, 48.5 +/- 9.0% increase respectively compared with 5.5mM glucose). Parallel to protein secretion levels, PDGF-B chain mRNA levels showed a significant increase (57.7%, 103.7%, 210.8% increase), while no change of beta-actin mRNA levels was observed. Thus, elevated PDGF released from endothelium by high glucose may play an important role in the pathogenesis of diabetic angiopathy.

Blotting, Northern↗
PubMed1992

Effect of insulin on the proline transport activity in cultured fibroblasts from patients with Werner syndrome.

The effect of insulin on the transport of proline has been studied in cultured fibroblasts from normal individuals, non-insulin-dependent diabetic patients, and patients with Werner syndrome. In fibroblasts from normal individuals and those with diabetes mellitus, incubation with 10(-7) M insulin resulted in more than a twofold increase in the transport rate after about 14 h incubation. In contrast, fibroblasts from patients with Werner syndrome had a markedly attenuated response to insulin, suggesting a defect in insulin action on the transport of this amino acid in Werner syndrome.

Adolescent↗
PubMed1992

Absence of colorectal cancer metastasis to the cirrhotic liver.

Hepatic metastasis of colorectal cancer was found in 40 (16%) of 250 patients with colorectal cancer treated in our department during the past 5 years. Liver cirrhosis was not found among the 40 patients with metastases (16%) but was present in 46 (21.9%) of the 210 nonmetastatic patients, with a significant difference between the two groups (p less than 0.001). The rate of patients who were positive for hepatitis B surface antibody was 10% in the metastatic group and 34.3% in the nonmetastatic group, with a significant difference (p less than 0.01). These findings suggest that colorectal cancer does not metastasize to the injured liver, especially the cirrhotic liver.

Colorectal Neoplasms↗
PubMed1992

Giant fistula between the right coronary artery and the left ventricle: diagnostic significance of right posterior oblique chest radiograph.

Congenital coronary artery fistulas are uncommon. The prevalence of coronary artery fistulas in adults has been estimated as 0.13% [1]. Most of these fistulas communicate with the right atrium or ventricle or with the pulmonary artery; those emptying into the left atrium or ventricle are quite rare [2, 3]. Usually, patients with coronary artery fistula do not have clinical symptoms, and their chest radiographs do not show the corresponding shadow because the fistula is hemodynamically insignificant. When the fistula is large, however, chest radiographs show the secondary hemodynamic changes, such as cardiac enlargement or increased pulmonary vasculature, depending on the emptying site. Moreover, the silhouette of the dilated tortuous vessel itself can be seen on the chest radiograph. We have examined four patients, each of whom had a giant fistula in the right coronary artery emptying into the left ventricle, proved by coronary angiography. In this essay, we illustrate the chest radiographs of these patients and describe the radiologic features that permit a specific diagnosis or suggest a coronary artery fistula.

Adult↗
PubMed1992

[Microsurgical autotransplantation of abdominal testis].

A 32-year-old man who had bilateral non-palpable testis underwent microsurgical orchidopexy of the right abdominal testis. Inferior epigastric vessels were used for the recipient vessels. Ischemic time during the operation was 40 minutes. Postoperative doppler readings revealed excellent blood flow to the testis, and HCG-stimulating test revealed good response. Now, 2 years after surgery, no sign of atrophy is found.

Adult↗
PubMed1992

[Clinical evaluation of the measurement of hepatosplenic volume ratio by computed tomography].

The liver and spleen volume ratio (S/L ratio) was estimated with X-ray computed tomography. Clinical usefulness of S/L ratio was evaluated by comparison with other liver functions (retention rate of ICG, total bilirubin, serum albumin and cholinesterase activity) in 42 hepatocellular carcinoma patients with liver cirrhosis. The correlation between S/L ratio and retention rate of ICG, total bilirubin, serum albumin or cholinesterase activity was good (r = 0.870, r = 0.719, r = -0.691, or r = -0.606, respectively p less than 0.001). Positive correlation was observed between S/L ratio and retention rate of ICG or total bilirubin. Negative correlation was observed between S/L ratio and serum albumin or cholinesterase activity. In conclusion, the measurement of S/L ratio on computed tomography was considered to be useful as an evaluation for the degree of severity in liver cirrhosis by considering both effective hepatic blood flow and portal hypertension.

Adult↗
PubMed1992

[Repeated arterial infusion chemotherapy for inoperable hepatocellular carcinoma using implantable drug delivery system].

We performed a clinical evaluation of repeated arterial infusion chemotherapy using an implantable drug delivery system for 41 patients with inoperable hepatocellular carcinoma (HCC). About half of our patients could not undergo transcatheter arterial embolization (TAE) because of extreme tumor extension and/or accompanying advanced cirrhosis. In most patients we implanted a 5 Fr. catheter non-surgically and connected it to an implanted injection port through a subcutaneous tunnel. The treatment schedule was weekly or biweekly intrahepatic one-shot administration of mitomycin C, adriamycin, 5-fluorouracil and epirubicin. The response rate (CR + PR) was 24.4%. The median survival period was 401.1 days. The 6 month, 1-year and 2-year survival rates were 73%, 48% and 24%, respectively. There were no severe side effects nor complications. The implantable drug delivery system will contribute not only to improved therapeutic efficacy for inoperable HCC but also improve the quality of life for patients.

Adult↗
PubMed1992

Amelioration of dermal lesions in streptozotocin-induced diabetic rats by aminoguanidine.

As aminoguanidine (AG) is known to prevent non-enzymatic glycosylation in various tissues, we have histologically and biochemically evaluated AG effects on the skin in control, SZ-diabetic and AG-treated (25 mg/kgbw/day, 10w) diabetic rats. HbA1c and plasma glucose levels in diabetic and AG-treated diabetic rats were maintained about two times higher than those in control rats during the 10 weeks of the experiment. Histological findings revealed that the dermis in diabetic rats was thin and edematous, associated with swelling and degeneration of collagen fibers. Necrobiotic changes were seen in the lower dermis. These changes were greatly improved in AG-treated diabetic rats. Skin glucose contents in diabetic and AG-treated diabetic rats were about 10 times higher than those in the controls, whereas there was no difference in the sorbitol contents between three groups. Dry weight of the skin and collagen content was well correlated (r = 0.9044) and collagen represented 78.0 +/- 2.3% of the dry weight. By SDS-PAGE analysis of cyanogen bromide digests it was shown that high molecular weight peptides were increased in diabetic rats, but were decreased in AG-treated diabetic rats. The mean of glycosaminoglycan (GAG) contents of diabetic skin was 54% of that in the controls (1.58 +/- 0.09 vs. 2.94 +/- 0.39 micrograms/mg dry weight, P < 0.0025), which increased significantly in AG-treated diabetic rats (1.75 +/- 0.07 microgram/mg dry weight, P < 0.01 vs. diabetic).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Plasma catecholamine levels during air-oxygen-enflurane anesthesia compared with those during nitrous oxide-oxygen-enflurane anesthesia].

This study was designed to investigate the differences in plasma levels of epinephrine, norepinephrine and dopamine during air-oxygen-enflurane anesthesia (AOE) and those during nitrous oxide-oxygen-enflurane anesthesia (GOE). These catecholamine levels were measured at 8 carefully defined points before and during hysterectomy or ovariectomy in two groups of each ten patients. Plasma levels of epinephrine decreased significantly immediately after intubation in both groups. In the AOE group, epinephrine levels increased significantly 30 and 60 minutes after the beginning of the operation. In the GOE group, however, epinephrine levels decreased significantly 15 and 30 minutes after the beginning of the operation. The difference between the two groups was statistically significant. Plasma levels of norepinephrine increased significantly after the beginning of the operation in the GOE group but no significant differences were found in the AOE group except the levels 60 minutes after the operation. The difference between the two groups was statistically significant 15 minutes after the operation. Plasma levels of dopamine remained unchanged in the two groups. Mean arterial pressure changed with intubation and surgical stress in the two groups. The arterial pressure was significantly higher 30 minutes after the operation in the GOE group compared with AOE group. Pulse rate increased significantly during anesthesia and surgery in the GOE group. It is concluded that AOE induces more increase of plasma epinephrine and less release of plasma norepinephrine compared with GOE.

Adult↗
PubMed1992

[Differences of regional blood flow after stellate ganglion block with local anesthetic and that after stellate ganglion resection using ultrasonic Doppler flowmeter].

Ten mongrel dogs were divided into two groups; stellate ganglion block (SGB, n = 5) group and stellate ganglion resection (SGR, n = 5) group. Anesthesia was induced with pentobarbital 25 mg.kg-1. The animals were mechanically ventilated to maintain a constant PaCO2 (35-40 mmHg). Left common carotid arterial flow (CCAF), left external carotid arterial flow (ECAF), left vertebral arterial flow (VAF) and left brachial arterial flow (BAF) were measured using an ultrasonic transit time flowmeter. Internal carotid arterial flow (ICAF) was calculated by subtracting ECAF from CCAF. After thoracotomy, the first SGB with 0.5% mepivacaine 1.5 ml or SGR was performed. Ninety minutes after the first SGB, the second SGB was performed. The data were taken for 180 minutes after the first SGB or SGR. In SGB, CCAF and BAF increased significantly for the duration of action of local anesthetic. But VAF and ICAF increased significantly for a short time after the block. In SGR, CCAF, BAF and ICAF increased significantly during the experiment. But VAF showed a transitory increase immediately after the resection. The authors conclude that sympathetic ganglion block with local anesthetic should be performed repeatedly when increase of blood flow in blood vessels with strong autoregulation from the brain is anticipated.

Animals↗
PubMed1992

[Cricoarytenoid joint involvement in rheumatoid arthritis].

The cricoarytenoid (CA) joint, which controls the vocal cords, is diarthrodial; it is composed of two cartilages with a ligamentous capsule lined by synovial membrane. It has been known that inflammation of CA joint occurs sometimes in patients with rheumatoid arthritis (RA). Yet, so far, no detailed full-report on this subject has ever been made in this country. Here we report four RA cases with CA joint ankylosis or abduction disturbance due to progression of CA arthritis. Episodes of inspiratory dyspnea were observed in all cases and tracheostomy was performed in case 1 and case 2. Further surgical intervention i.e., tracheoplasty was necessary in case 2. Case 3 and case 4 have been followed conservatively thus far. Clinical surgical interventions were necessitated mainly with joint replacement, 3) there exists severe destruction of cervical spines as well as temporomandibular joints. Rheumatologist must be fully aware of how urgent this clinical entity is and not miss-diagnose+ these patients.

Arthritis, Rheumatoid↗
PubMed1992

[Electrophysiological evaluation of diazepam anesthetic effect by "automated fluctuation analysis" of high frequency EEG in human].

"Automated fluctuation analysis" of human scalp EEG was made in order to evaluate anaesthetic effect of intravenous diazepam injection. Seven patients without disturbed consciousness were utilized for this study. Analytical system is composed of high fidelity pre-amplifier and signal processor. After 10,000 amplification of the signal, A/D conversion and Fast Fourier Transform were programmed with following parameters, sweep time; 12 sec., frequency resolvability; 1.2 Hz, frequency limit; 1 kHz, Fourier points; 2048 and Fourier time; 15. Power spectral density (PSD) was displayed on log-log graph. The best curve fitting program was next applied to the following equation, S(f) = S1/[1 + (f/fcl)2]+S2/[1 + (f/fc2)2] S(f): power spectral density, S1,S2: plateau levels of the initial and the second Lorentz, fcl, fc2: the corner or half power frequencies of the initial and the second Lorentz). As results, 1) PSDs of high frequency EEG up to 1 kHz were composed of double Lorentzian fluctuations. 2) From our previous animal study, it is suggested that the initial and the second Lorentz reflect the cortical and subcortical functions, respectively. 3) After diazepam injection, the second Lorentz was suppressed according to the time and dose and disappeared when the subjects fell asleep, and reappeared when waked up. There was excellent correlation between the consciousness level and the second Lorentz. 4) The initial Lorentz reflected higher cortical function; the ability of calculation or language were reduced after diazepam injection, and the hyperfrontal activity of the initial Lorentz disappeared. These results may suggest that "Automated Fluctuation Analysis" of high frequency EEG may have a potential to develop a new field in clinical neuroelectrophysiology.

Adult↗
PubMed1992

Hemodynamic effects of cilostazol on peripheral artery in patients with diabetic neuropathy.

On the basis of vascular involvement, an open clinical trial was performed to determine whether or not the antithrombotic drug cilostazol (6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H)-quinolinone, OPC-13013, Pletaal, CAS 73963-72-1) applied as a single 100 mg tablet increases peripheral blood flow and prevents diabetic neuropathy in 30 patients with non-insulin dependent diabetes mellitus. The hemodynamic effects of this drug on the a. dorsalis pedis were examined using a new real-time two-dimensional Doppler echography. 1 h after oral administration of cilostazol, the cross-sectional area of the a. dorsalis pedis significantly increased from 2.2 +/- 0.2 to 2.9 +/- 0.3 mm2 (p less than 0.05). Also, the a. dorsalis pedis blood flow index significantly increased from 16 +/- 1 to 31 +/- 4 (p less than 0.05). Cilostazol did not affect plasma glucose level (from 213 +/- 14 to 198 +/- 15 mg/dl), but slightly plasma ratio of 6-keto PGF1a to TXB2 (from 0.71 +/- 0.09 to 0.83 +/- 0.12). These effects of cilostazol might ameliorate diabetic neuropathy by improving blood flow and preventing nerve tissue ischemia.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Testosterone dependent regulation of the enzymes involved in DNA synthesis in the rat ventral prostate.

The effects of testosterone on the activities of DNA polymerase alpha, beta, and gamma as well as topoisomerase I (all enzymes involved in DNA synthesis) were examined in the rat ventral prostate. The activities of these four enzymes decreased gradually after castration in comparison with normal controls, and continued to decrease until the 14th day. Enzyme activities were almost restored to normal within 48 to 72 hr. of the commencement of daily testosterone injections (0.3 mg./0.2 ml.), and increased successively until the 14th day. The wet weight, protein content, and DNA content of the rat ventral prostate decreased after castration, while following testosterone therapy all these parameters increased to equal or exceed the control levels. These results suggested that the activities of DNA polymerase alpha, beta, and gamma and topoisomerase I are at least partially regulated by testosterone, and that these enzymes play an important role in the regulation of prostatic cellular proliferation.

Animals↗