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Biomedical subjects

Y Okuda

Publications and source records attributed to Y Okuda.

At least 109 records · Page 6Linked to original sources
PubMed1999

Propofol prevents delayed neuronal death following transient forebrain ischemia in gerbils.

PURPOSE: This study was conducted to ascertain whether propofol may protect against delayed neuronal death in the hippocampal CA1 subfield in gerbils. METHODS: Thirty-five gerbils were randomly assigned to five groups: Group I, the control group, a sham operation treated with physiological saline solution (PSS); Group II, ischemia/reperfusion treated with PSS; Group III, ischemia/reperfusion treated with 50 mg x kg(-1) propofol; Group IV, ischemia/reperfusion treated with 100 mg x kg(-1) propofol; Group V ischemia/reperfusion treated with 150 mg x kg(-1) propofol. Transient forebrain ischemia was induced by occluding the bilateral common carotid arteries for four minutes under N2O/O2/halothane anesthesia after administration of propofol or PSS. Five days later, histopathological changes in the hippocampal CA1 subfield were examined using a light microscope and degenerative ratio of the pyramidal cells were measured according to the following formula: (number of degenerative pyramidal cell/total number of pyramidal cells per 1 mm of hippocampal CA1 subfield) x 100. RESULTS: In group II, the pyramidal cells were atrophic and pycnotic; vacuolation and structural disruption of the radial striated zone was observed. In the other four groups, these changes were not observed. The degenerative ratios of pyramidal cells were as follows; group I: 5.9 +/- 1.9%, group II: 94.6 +/- 2.5% (P < 0.01), group III: 10.7 +/- 1.7%, group IV: 9.7 +/- 1.8%, group V: 9.2 +/- 1.9%. CONCLUSION: This study suggests that propofol may prevent delayed neuronal death in the hippocampal CA1 subfield after cerebral ischemia/reperfusion in gerbils.

Analysis of Variance↗
PubMed1999

Effects of intraocular or systemic administration of neutralizing antibody against vascular endothelial growth factor on the murine experimental model of retinopathy.

Vascular endothelial growth factor (VEGF), the strongest known angiogenic cytokine and also a potent enhancer of vascular permeability, is closely associated with diabetic ocular complications and other intraocular neovascular diseases. The therapeutic effect of VEGF-neutralizing antibody on oxygen-induced retinopathy in an experimental murine model of proliferative retinopathy was investigated. Intraocular and systemic injection of the antibody resulted in 46% and 18% reductions in the number of nuclei of newly formed vessels of this model, respectively. The results demonstrated that a neutralizing antibody against VEGF was highly effective in the treatment of intraocular neovascularization and suggested possible modes of therapy in human intraocular neovascular diseases, including diabetic proliferative retinopathy.

Animals↗
PubMed1999

A new biflavonoid from Calophyllum panciflorum with antitumor-promoting activity.

A new biflavonoid named pancibiflavonol (1) was isolated from an EtOH extract of the stem bark of Calophyllum panciflorum, along with six known biflavonoids, and its structure was elucidated by spectroscopic methods. These biflavonoids all exhibited significant inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate-induced Epstein-Barr virus early antigen activation in Raji cells.

Antineoplastic Agents↗
PubMed1999

Troglitazone and pioglitazone attenuate agonist-dependent Ca2+ mobilization and cell proliferation in vascular smooth muscle cells.

1. The effects of troglitazone and pioglitazone on agonist-induced Ca2+ mobilization and cell proliferation were studied using fluorescent Ca2+ indicator fura-2 AM and incorporation of [3H]-thymidine in rat aortic smooth muscle cells. The patch clamp techniques were also employed. 2. Vasopressin and platelet-derived growth factor-BB (PDGF) caused a transient elevation in [Ca2+]i by Ca2+ mobilization from intracellular stores, followed by a sustained rise due to Ca2+ entry. Nicardipine partly inhibited the sustained phase, but La3+ completely abolished it. 3. Troglitazone and pioglitazone did not significantly affect the transient rise elicited by these agonists, but preferentially inhibited the sustained phase of [Ca2+]i. 4. Under voltage clamp conditions, troglitazone and pioglitazone inhibited voltage-dependent L-type Ca2+ current (ICa.L). They also inhibited nonselective cation channels (Icat) elicited by vasopressin in a concentration-dependent manner. The half maximal inhibitory concentrations of troglitazone on ICa.L and Icat were 4.6 and 5.7 microM, respectively. On the other hand, nifedipine and nicardipine did not inhibit Icat. 5. Vasopressin and PDGF increased incorporation of [3H]-thymidine, and nifedipine and nicardipine partly suppressed it. However, the inhibitory effects of La3+ and exclusion of extracellular Ca2+ were more potent than the Ca2+ blocking agents. Troglitazone and pioglitazone also inhibited it concentration-dependently. 6. These results suggest that troglitazone and pioglitazone preferentially inhibited agonist (vasopressin and PDGF)-induced Ca2+ entry and proliferation in rat vascular smooth muscle cells, where the inhibitory effects of thiazolidinediones on ICa.L and Icat might be partly involved. Thus, thiazolidinediones may exert hypotensive and antiatherosclerotic effects.

Animals↗
PubMed1999

Klinefelter's syndrome in the male infertility clinic.

The clinical features of patients with Klinefelter's syndrome attending a male infertility clinic have been investigated in order to consider their assisted reproduction treatment options. Over 12 years, a total of 148 patients with sterility due to azoospermia had Klinefelter's syndrome. Eight patients were shown by fluorescence in-situ hybridization (FISH) on metaphase spreads to be mosaic (46,XY/47,XXY), and 140 patients showed only 47,XXY. Small testes were observed in 95% of patients and gynaecomastia was seen in 12.4%. Half of the patients showed hypergonadotrophic hypogonadism, while others showed normogonadism (usually hypergonadotrophic). Spermatozoa were observed in semen from one patient with mosaicism and one without. Three-colour FISH revealed hyperploidy in 2.7% and 2.3% of these spermatozoa respectively. Multiple-site testicular biopsies in five recent patients were performed and yielded a specimen with round and elongated spermatids in one patient with 47,XXY karyotype. This sample was cryopreserved for future intracytoplasmic sperm injection. At follow-up, 46% of couples had chosen artificial insemination with donor sperm, and none had chosen adoption. Two patients developed testicular tumours, one a mature teratoma and the other a Leydig cell tumour. Two patients required androgen replacement therapy.

Adult↗
PubMed1999

The effects of combined sympathetic block and intravascular infusion of prostaglandin E1 on brachial arterial blood flow in dogs.

UNLABELLED: We compared the effects of stellate ganglion block (SGB) with those of SGB combined with an intravascular infusion of prostaglandin E1 (PGE1) on brachial arterial blood flow (BABF) in 24 mongrel dogs. The experimental protocol was designed so that the dogs received one of the following: SGB with 0.5% mepivacaine 1.0 mL (n = 8); combined SGB and IV infusion of PGE1 at a rate of 150 ng x kg(-1) x min(-1) for 10 min (n = 8); or combined SGB and intraarterial (IA) infusion of PGE1 at a rate of 0.1 ng x kg(-1) x min(-1) for 10 min (n = 8). BABF increased significantly in all groups and reached a maximum of 67% 10 min after SGB, 124% with the combined SGB and IV infusion of PGE1, and 117% with the combined SGB and IA infusion of PGE1. We conclude that combined SGB and IV or IA infusion of PGE1 increases BABF significantly compared with SGB alone. IMPLICATIONS: Combined stellate ganglion block and intraarterial or IV infusion of prostaglandin E1 increases brachial arterial blood flow significantly compared with stellate ganglion block alone.

Alprostadil↗
PubMed1999

Selective ablation of porcine and rabbit liver tissue using radiofrequency: preclinical study.

Temperature changes and their distribution induced by 13.56-MHz radiofrequency (RF) heating of agar phantom and porcine and rabbit liver were investigated. It was possible to produce selective local heating of approximately 50 degrees C in the RF field of 2 x 2 x 2 cm(3) of the pig or rabbit liver. Coagulation necrosis after heating became pronounced and the margin between the coagulated lesion and normal tissue became clearer with time. Within 1 week after RF heating at 50 degrees C for 20 min, the coagulated area was replaced selectively and totally by necrotic tissue.

Animals↗
PubMed1999

[Reproductive and developmental toxicity study of gadobenate dimeglumine formulation (E7155) (3)--Study of embryo-fetal toxicity in rabbits by intravenous administration].

Gadobenate dimeglumine formulation (E7155) was daily administered by intravenous injection at 0.3, 0.9 or 2.0 mmol/kg/day to mated NZW female rabbits (20/group) to assess the effect on embryo-fetal development. Treatment with 2.0 mmol/kg/day caused initial, notable loss of body weight and reduction in food consumption. Slightly reduced body weight gain and food intake were recorded at 0.9 mmol/kg/day. There were no obvious adverse effects in dams given E7155 at 0.3 mmol/kg/day. There was a slightly higher incidence of early intrauterine deaths at 0.9 and 2.0 mmol/kg/day. Morphological examination of fetuses at 2.0 mmol/kg/day revealed small eye/microphthalmia and/or retinal irregularities in three fetuses from three separate litters. There was also an increase in the incidence of additional and/or fused sternebral centres and 20-thoracolumbar vertebrae at this dosage. From these results, the No Observed Adverse Effect Level (NOAEL) for general toxicity of dams and embryo-fetal development was 0.3 mmol/kg/day.

Abnormalities, Drug-Induced↗
PubMed1999

[Differential epidural block for definitive diagnosis of snapping hip joint].

Snapping hip joint syndrome is defined as snapping phenomenon accompanied by motion of the hip joint. It occurs from various causes, and its diagnosis and treatment are often difficult. We gave anesthesia for surgery against snapping hip joint under patient's active motion for definitive regional diagnosis. Differential epidural block, which precludes pain while maintaining motor function, was performed by 0.25% bupivacaine, 0.5% lidocaine, and additional administration of fentanyl by 25 micrograms. Although the mechanism of differential nerve block remains to be unknown, the case suggests that effective pain block preserving motor function may be achieved by differential epidural block in combination with low concentration of local anesthetics and small dose of opioid.

Adult↗
PubMed1999

[Patient-controlled sedation in a patient with respiratory dysfunction for reconstructive surgery of submandibular fracture under local anesthesia].

A 70-year-old male with respiratory dysfunction, chronic obstructive pulmonary disease associated with asthmatic component, received patient-controlled sedation (PCS) using propofol for reconstructive surgery of submandibular fracture under local anesthesia. PCS produced sedation levels between eyelid closure with prompt response to verbal commands and drowsiness. Respiratory disturbance and hemodynamic change were not recognized. The patient was very cooperative, and felt comfortable during the operation. Propofol PCS is an appropriate method for a patient with respiratory dysfunction under local anesthesia.

Aged↗
PubMed1999

[Serum amyloid A (SAA) 1, SAA 2 and apolipoprotein E isotype frequencies in rheumatoid arthritis patients with AA amyloidosis].

OBJECTIVES: To examine the relationship between polymorphism of serum amyloid A (SAA) 1, SAA 2 and Apolipoprotein E (Apo E) and susceptibility to AA amyloidosis (AA) in rheumatoid arthritis (RA). METHODS: We compared the frequencies of SAA 1 alleles (alpha, beta, gamma), SAA 2 alleles (alpha, beta) and apo E alleles (epsilon 2, epsilon 3, epsilon 4) in AA-positive RA with those in AA-negative RA. Each isotype was analyzed by the following method: SAA 1 and SAA 2 by PCR-RFLP and Apo E by Western blotting method. Blood samples were obtained from 50 AA-positive RA patients with SAA 1 isotype, 50 AA-negative RA patients with SAA 1 isotype, 27 AA-positive RA patients with SAA 2 isotype, and 26 AA-negative RA patients with SAA 2 isotype, respectively. Likewise, Apo E isotype was determined by withdrawing blood samples from 61 AA-positive RA cases and 51 AA-negative RA cases. RESULTS: In AA-positive RA, each frequency of three different alleles of SAA 1, i.e., alpha, beta and gamma was 15%, 32% and 53%, while it was 32%, 28% and 40% in AA-negative RA. The allelic distribution between AA-positive RA group and AA-negative RA group was significantly different (P = 0.00163) with a lower frequency of alpha allele and a higher gamma allele frequency observed in AA-positive RA group. The frequency of each SAA 2 alleles (alpha & beta) was almost identical: 88.9% and 11.1% in AA-positive RA versus 90.4% and 9.6% in AA-negative RA with p value of 0.8007. Each frequency of three different Apo E alleles (epsilon 2, epsilon 3 & epsilon 4) was 4.9%, 85.2% and 9.8% in AA-positive RA, while in AA-negative RA it was 7.8%, 86.3% and 5.9%, respectively. The AA-positive RA group showed a slightly higher prevalence of epsilon 4 allele than the AA-negative RA group, yet the difference did not reach statistical significance (P = 0.3969). CONCLUSIONS: These results suggest the possibilities that SAA 1 alpha may be working protectively against and SAA 1 gamma provocatively for the development of AA amyloidosis in RA. However, there was no significant association between SAA 2 isotype patterns and the development of AA amyloidosis in RA. Furthermore, there was no discernible association between AA amyloidosis in RA and Apo E 4 isotype.

Amyloidosis↗
PubMed1999

[A case of total intravenous anesthesia with propofol, fentanyl and ketamine for lateral segmentectomy of the liver under pringle maneuver].

We successfully anesthetized an 80-year-old female for Pringle maneuver which was applied at the time of liver transection and consisted of cross-clamping the hepatoduodenal ligament for 25 minutes and releasing the clamp for 2 minutes until the completion of the liver transection. Anesthesia chosen was total intravenous anesthesia with propofol, fentanyl and ketamine (PFK) in combination with epidural anesthesia. The plasma concentrations of propofol at pre-, intra-, and post-Pringle maneuver under the intravenous infusion of propofol at 3 mg.kg-1.h-1 were 0.84, 1.49, and 1.29 micrograms.ml-1, respectively. All operative procedures were done uneventfully and recovery from anesthesia was prompt after the end of propofol infusion. Transient increases in liver enzymes were seen during early postoperative period, but no signs of hepatic failure were observed. In this patient, PFK anesthesia was useful and safe for the liver transection with Pringle maneuver.

Aged↗
PubMed1999

[Leak test for the internal circuit of anesthesia machines].

In spite of detailed periodic inspection performed by specialized engineers, a great number of anesthesia machines fail to meet the standard of low flow leak test because of leak in the internal circuit. To find out the background and the solution to the problem, we sent questionnaire to 11 major manufacturers and/or dealers each responsible for periodic inspection of anesthetic machines. According to the responses to the questionnaire, the manufacturers and/or the dealers had various methods of internal circuit leak test without a unified standard in detail. The mismatch of the test methods with those anesthesia machines equipped with check valve mechanism has also led to poor evaluation of internal circuit leak. Leak test must be standardized for its appropriate application to work effectively for the problem of leak in the internal circuit of anesthesia machines.

Anesthesiology↗
PubMed1999

[The current state of leak in anesthetic machines detected by low flow leak tests].

To assess the current state of leak in anesthetic machines, we selected 66 units of anesthetic machines for inspection and repair from various medical institutions. Based on a newly designed inspection flow chart a low flow leak test for internal circuits of the anesthetic machines was performed. The conventional low flow leak test was also performed for smooth detection of leak for rational evaluation. Only 39% of the anesthetic machines met the standard of the low flow leak tests, and leak was detected in the remaining 61%. The average residual leak mounted to 0.97 l.min-1, with the maximum of 5.3 l.min-1. Canisters, corrugated tubes, and vaporizers were considered the primary causes of leak. After the inspection and repair, leak in 77.5% of the anesthetic machines either disappeared or decreased and the average residual leak dropped to 0.34 l.min-1. However, 47% of the anesthetic machines still failed to meet the standard of the low flow leak tests. To further improve the situation, more detailed inspection and repair are necessary especially for precise detection of the cause of leak in the internal circuit of anesthetic machines which often remains undetected.

Anesthesiology↗