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Biomedical subjects

M Okada

Publications and source records attributed to M Okada.

At least 415 records · Page 23Linked to original sources
PubMed1999

An experimental study of surgical treatment for lymphedema in rats: A modified Kinmonth procedure and autologous lymph node capsule-venous anastomosis with lymph node transfer.

This study was carried out in order to determine the effect of various surgical procedures on lymphedema in a rat model. In 26 adult male Sprague-Dawley rats, randomly divided into four groups, surgical lymphedema was created in the left hind limbs.: The control group had no drainage, Group 1 had a conventional Kinmonth operation, Group 2 had a modified Kinmonth operation using the greater omentum and Group 3 had autologous lymph node capsule-venous anastomosis with lymph node transfer. Circumference measurement was performed to calculate percent difference and circumferential reduction rate. In Groups 2 and 3, patent blue violet was injected to identify lymphatics. In all groups, hematoxylin-eosin (H-E) and 5'-nucleotidase stainning were done to evaluate lymphatics histopathologically. The percent difference and the circumferential reduction rate respectively showed the smallest and largest values in Group 2. A significant difference was found between the control group and Group 2 (p < 0.05). Lymphatic vessels were shown by patent blue violet injection in Groups 2 and 3. H-E and 5'-nucleotidase staining revealed patency of lymphatics. A modified Kinmonth procedure using the greater omentum was the most effective procedure for early lymphedema in a rat model and autologous lymph node capsule-venous anastomosis with lymph node transfer was effective for lymph draining in certain conditions, so it may assist in elucidating surgical treatment of lymphedema.

Anastomosis, Surgical↗
PubMed1999

Pharmacological properties of J-104132 (L-753,037), a potent, orally active, mixed ETA/ETB endothelin receptor antagonist.

J-104132 [(+)-(5S,6R, 7R)-2-butyl-7-[2-((2S)-2-carboxypropyl)-4-methoxyphenyl]-5-(3, 4-methylenedioxyphenyl)cyclopenteno[1,2-b]pyridine-6-carboxylic; also referred to as L-753,037] is a potent, selective inhibitor of ETA and ETB endothelin (ET) receptors (e.g., Ki: cloned human ETA = 0.034 nM; cloned human ETB = 0.104 nM). In both ligand-binding and isolated tissue preparation protocols, the inhibition of ET receptors with J-104132 is reversible and competitive. In vitro, J-104132 is a potent antagonist of ET-1-induced accumulation of [3H]inositol phosphates in Chinese hamster ovary cells stably expressing cloned human ETA receptors (IC50 = 0.059 nM), ET-1-induced contractions in rabbit iliac artery (pA2 = 9.70) and of BQ-3020-induced contractions in pulmonary artery (pA2 = 10.14). J-104132 is selective for ET receptors because it had no effect on contractions elicited by norepinephrine or KCl in the vascular preparations. The in vivo potency of J-104132 was assessed using challenges with exogenous ET-1. In conscious mice, 5 nmol/kg i.v. ET-1 causes death. Pretreatment with J-104132 prevents the lethal response to ET-1 when administered i.v. (ED50 = 0.045 mg/kg) or p.o. in fed animals (ED50 = 0.35 mg/kg). In conscious, normotensive rats, pressor responses to 0.5 nmol/kg i.v. ET-1 are inhibited by J-104132 after i.v. (0.1 mg/kg) or p.o. (1 mg/kg) administration. In anesthetized dogs, ET-1 was administered directly into the renal artery or brachial artery to generate dose-response (blood flow) curves, and the inhibitory potency of J-104132 (i.v. infusion) was quantified. J-104132 produced greater than 10-fold shifts in the ET-1 dose-response curves at 0.03 mg/kg/h (renal) and 0.3 mg/kg/h (brachial). Oral bioavailability of J-104132 in rats was approximately 40%. These studies indicate that J-104132 is a selective, potent, orally active antagonist of both ETA and ETB receptors and is an excellent pharmacological tool to explore the therapeutic use of a mixed ETA/ETB receptor antagonist.

Animals↗
PubMed1999

Simultaneous surgery for infective endocarditis and endophthalmitis.

A 54-year-old woman was diagnosed as having septicemia secondary to infective endocarditis with aortic regurgitation which was complicated by endophthalmitis. Her septicemia was controlled by intravenous antibiotic therapy. Then the localized eye infection and the aortic regurgitation with a massive vegetation were surgically treated simultaneously. She had no relapse of infection after intensive postoperative antibiotic therapy.

Endocarditis, Bacterial↗
PubMed1999

[Comparison of the therapeutic effects and acid suppression of H2-receptor antagonist and proton pump inhibitor in patients with gastric body ulcer--a prospective controlled trial].

We studied, the rate and the affecting factor of ulcer healing of patients with gastric body ulcer treated by H2-receptor antagonist (H2-RA) and proton pump inhibitor (PPI). Gastric acidity was also examined using 24 hr pH monitoring. No difference was observed between the affecting factor of ulcer healing and healing rate (94.7% and 94.9%) among the patients treated by H2-RA or PPI. The average time below pH3 during treatment with H2-RA or PPI were 17.4 +/- 4.3 hr and 23.0 +/- 1.5 hr, respectively. Acid suppression was superior in PPI treated group than in H2-RA group. From these findings, we concluded that H2-RA had sufficient therapeutic efficacy in treating gastric body ulcer.

Anti-Ulcer Agents↗
PubMed1999

Clinical study on recurrence in bladder cancer patients undergoing total cystectomy--statistical analysis of factors related to recurrence.

A clinico-pathological study was performed retrospectively for 77 patients undergoing total cystectomy for primary transitional cell carcinoma of the urinary bladder between 1981 and 1995 to clarify the mode of recurrence, the risk factors which may affect recurrence following cystectomy and prognostic factors. Postoperative recurrence was recognized in 27 (35.1%) out of 77 patients and the one-, two- and three-year non-recurrent rates by the Kaplan-Meier method were 75.3, 64.9% and 63.3%, respectively. The duration from cystectomy to recurrence was 1 to 102 months with a mean of 12.1 months, and approximately 92.6% of recurrence occurred within two years. Among 27 patients with recurrence, pelvic recurrence, distant metastasis, both of them and urethral recurrence were recognized in 6 (22.2%), 18 (66.7%), 1 (3.7%) and 2 (7.4%), respectively as the first site of recurrence. The overall one-, three- and five-year cause-specific survival rates of the 77 patients were 84.7, 71.1% and 65.6%, respectively. Of the 27 patients with recurrence, 25 (92.6%) died of bladder cancer. Of the factors related to recurrence or prognosis, pathological stage, lymphatic invasion, venous invasion, type of infiltration and lymph node metastasis but not pathological grade or adjunctive chemotherapy were significant risk factors for recurrence and prognostic factors in univariate analysis. However, lymphatic invasion was the only significant risk factor for recurrence and prognosis in multivariate analysis using Cox's proportional hazard model.

Adult↗
PubMed1999

[A case of subclinical IgA nephropathy and cyclosporin associated arteriolopathy diagnosed by non-episode biopsy of graft kidney after renal transplantation].

We report a case of subclinical immunoglobulin A (IgA) nephropathy and cyclosporin associated arteriolopathy following renal transplantation. A 39-year-old male with chronic glomerulonephritis received kidney transplantation from a two- human leukocyte antigen (HLA) mismatched cadaveric donor. The initial immunosuppressive therapy was triple-drug therapy with cyclosporin, prednisolone and mizoribine. Four months after transplantation, he had an acute rejection episode, and the renal function was recovered by steroid pulse and 15-deoxyspergualin therapy. Eight years after transplantation, we conducted a non-episode biopsy of the renal allograft to examine subclinical lesions. The histopathological findings showed cyclosporin associate arteriolopathy (CAA) and IgA nephropathy. There was no sign of acute or chronic rejection. At the present time, the renal function of the allograft is good. In conclusion, the non-episode biopsy of renal allograft is useful for examination of subclinical lesions.

Biopsy↗
PubMed1999

Experimental studies on application of small-caliber vascular prosthesis produced by polyurethane.

It has been suggested that a microporous structure enhances fast and complete endothelialization. For long-term patency, antithrombogenicity and microporous structure are very important factors. In this paper, we have developed a new technique to give a micro-porous structure to small-caliber vascular prosthesis produced by polyurethane which has favorable antithrombogenecity. A mixed solution (tetrahydrofuran: dimethylformamide = 1:1) containing 13 wt% of segmented polyurethane and a variable amount of calcium carbonate (mean particle size of 8 mm in diameter) was dip-coated on a glass mandril of 3 mm and 6 mm in diameter and placed into distilled water for 24 hours. After the glass mandrill was removed, this polyurethane tube was placed into 1 mmol hydrochloric acid for 1 hour, and a microporous polyurethane vascular prosthesis of 20 mm in length was completed. These prostheses of 3 mm and 6 mm in diameter were implanted into the femoral and the carotid arteries, and the abdominal aorta of the dogs, respectively. Patency was recognized by arteriography and Duplex scanning and the removed grafts were inspected macro- and microscopically. Greater hydraulic permeability of this graft was obtained with an increase in the quantity of calcium carbonate mixed with polyurethane. In elasticity, this graft was more similar to the canine jugular vein than the polytetrafluoroethylene graft. Patency was observed 8 weeks after implantation on the arteriogram, and neointima was observed microscopically on the smooth and lustrous lumen. The new polyurethane vascular prosthesis we developed might provide a potential prosthesis for small-caliber vascular reconstruction.

Animals↗
PubMed1999

Effect of oleanolic acid-cyclodextrin inclusion compounds on dental caries by in vitro experiment and rat-caries model.

Earlier work in vitro showed that oleanolic acid (OA) was a potential inhibitor of insoluble glucan (ISG) synthesis from mutans streptococci (MS). In this study, two oleanolic acid-cyclodextrin inclusion compounds (OA-CDs), oleanolic acid-G1-beta-cyclodextrin (OA-G1-beta CD) and oleanolic acid-beta-cyclodextrin (OA-beta CD), were assayed for their effects on ISG synthesis from Streptococcus mutans MT8148R, and on the growth of oral bacteria. OA-beta CD inhibited ISG synthesis by 55.3 and 37.4% at 62.5 and 15.6 micrograms/ml of OA, respectively. Both OA-CDs inhibited the growth of MS, S. sanguis, and S. salivarius at 4 to 8 micrograms/ml of OA. The anticariogenic effect of the OA-beta CD was examined in a rat-caries model. Rats in the infected control groups showed the highest caries score. The infected treatment group B (0.5% OA in diet) showed lower scores than the control group. These results suggest that OA-beta CD is a potential anti-caries agent.

Animals↗
PubMed1999

[Denervation of the cervical sympathetic nerve inhibited the splenic natural killer cell activity by modulation of the splenic sympathetic nerve activities in rats].

It is known that the splenic natural killer cell (NK) activity 4 weeks after unilateral resection of the cervical sympathetic nerve (csn) is significantly lower than that after sham operation in rats. To investigate the role of the splenic sympathetic nerve, the splenic NK activity after csn was compared in the control animals (n = 9) and the splenic sympathetic nerve denervated animals (n = 8). The splenic NK activity in control group was reduced significantly after csn, whereas that in splenic nerve denervated group did not reveal significant change after csn. The results suggest that the reduction of the splenic NK activity after csn is induced through the modulation of the splenic sympathetic nerve activities.

Animals↗
PubMed1999

Fluconazole versus amphotericin B for the prevention of fungal infection in neutropenic patients with hematologic malignancy.

Effective prophylaxis against fungal infection is important in neutropenic patients with hematologic malignancies, but the best method remains unclear. We investigated the effectiveness of fungal prophylaxis with amphotericin B or fluconazole. We reviewed the data on fungal isolates, plasma (1-->3)-beta-D glucan (beta-D glucan) levels, febrile periods (the number of days with an axillary temperature > 38 degrees C), and the duration of an axillary temperature > 38 degrees C when the neutrophil count was < 500/microliter. Of the 124 patients studied, 57 had acute myelogenous leukemia, 19 had acute lymphoblastic leukemia, 18 had non-Hodgkin's lymphoma, six had chronic myeloid leukemia, three had adult T-cell leukemia, and five had chronic lymphocytic leukemia. There were no significant differences in clinical characteristics between the 70 patients treated with amphotericin B and the 54 patients given fluconazole. There was a significant decrease of fungal isolates (chi 2-test, p < 0.001), the plasma beta-D glucan level (Wilcoxon test, p = 0.0001), and the febrile period (t-test, p < 0.05) in the patients given fluconazole compared with those given amphotericin B. In neutropenic patients with hematologic malignancies, prophylaxis with fluconazole significantly decreased fungal isolation and other indicators of fungal infection when compared with amphotericin B. Fluconazole may therefore be more effective for fungal prophylaxis in these patients.

Adolescent↗
PubMed1999

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1997)].

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 17 institutions around the entire Japan, 512 strains of presumably etiological bacteria were isolated mainly from the sputa of 440 patients with lower respiratory tract infections during the period from October in 1997 to September in 1998. MICs of various antibacterial agents and antibiotics were determined against 100 strains of Staphylococcus aureus, 81 strains of Streptococcus pneumoniae, 85 strains of Haemophilus influenzae. 71 strains of Pseudomonas aeruginosa (non-mucoid strains), 27 strains of Pseudomonas aeruginosa (mucoid strains), 33 strains of Moraxella subgenus Branhamella catarrhalis, 17 strains of Klebsiella pneumoniae etc., and the susceptibilities of these strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 55.0%. The frequency of the drug resistant bacteria decreased comparing to the previous year's 67.3%. Arbekacin (ABK) and vancomycin (VCM) showed the most potent activities against MRSA. Imipenem (IPM) and panipenem (PAPM) of carbapenems showed the most potent activities with MIC80S of 0.063 microgram/ml against S. pneumoniae. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP)+PC-resistant S. pneumoniae (PRSP) had decreased gradually, that is, in 1995 the frequency of it was 40.3%, but that was 30.9% in 1997. Against H. influenzae and M.(B.) catarrhalis, all the drugs showed good activities. But the sensitive strains of them against ceftazidime (CAZ) had decreased in 1997, compared those in 1995 and 1996. Meropenem (MEPM), IPM and tobramycin (TOB) showed the most potent activity against P. aeruginosa (mucoid strains). And TOB and ciprofloxacin (CPFX) showed the most potent activities against P. aeruginosa (non-mucoid strains). All drugs except ampicillin (ABPC) were more active against K. pneumoniae in 1997 than that in 1996. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 45.5% of all the patients showing a slight increase year by year. About the proportion of diagnosed diseases, not so particular changes were recognized as follows: Bacterial pneumonia and chronic bronchitis were the most frequent with 33.6% and 29.1%, respectively. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these had reversed in bacterial pneumonia. The tendency in bacterial pneumonia had been acknowledged since 1995. The increase of S. aureus and P. aeruginosa (both mucoid and non-mucoid strains) isolated after administration of antibiotics, has suggested the decrease of the susceptibility of these strains against antibiotics. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 24.5%, H. influenzae 21.4%, S. aureus 18.4% and P. aeruginosa 12.2%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa was not affected. The frequencies of P. aeruginosa was 47.8% after administration over 15 days. From patients administered antibiotics of penicillins and cephems. S. aureus was mainly detected with 31.7-58.3%, and from patients administere

Adult↗
PubMed1999

Evaluation of acute aortic dissection by cine-MRI.

UNLABELLED: We investigated operative indication of acute aortic dissection by analyzing the movement of the intimal flap using cine-MRI. METHODS: Ten consecutive cases of acute aortic dissection diagnosed between December 1997 and September 1998 participated in this study. Six of these patients had in Stanford type A and four Stanford type B aortic dissection. The diagnosis of aortic dissection was based on demonstration of two aortic channels with each cardiac cycle. After obtaining SE(spin-echo) images, gradient echo sequences (FFE) were obtained such that the false lumen was maximally imaged and the intimal flap was depicted perpendicularly. During one RR-interval of ECG, 12 to 16 measurements were recorded and combined in a cineloop mode. We defined the intimal flap, the site of the entry and thrombosis in the false lumen, and evaluated the movement of the intimal flap as the flap movement index (FMI). Maximum and minimum aortic diameters (ADmax, ADmin), as well as maximum and minimum false lumen diameters (FDmax, FDmin) were measured. FMI was defined as[(FDmax/ADmax) - (FDmin/ADmin)]/(FDmin/ADmin) x 100(%). RESULTS: Total thrombosis was noted in four cases, partial thrombosis in 3, and in the remaining 3 no thrombosis of the false lumen was noted. The FMI ranged between 4% and 87% (mean 26.3 +/- 8.6%). Among the 4 cases with the large FMI of greater than 30%, 3 underwent emergency surgery and were confirmed to have no thrombosis in the false lumen. The fourth case, who had partial thrombosis, underwent medical therapy, but since complete thrombosis in the false lumen never did occur in this case, surgery became absolutely necessary. The other 6 cases with a FMI of less than 30% showed a tendency toward gradual reduction of the false lumen. CONCLUSION: FMI is a potentially useful parameter in cases with acute aortic dissection to determine whether or not emergency surgery is indicated.

Acute Disease↗
PubMed1999

Strategy for prevention of myonephropathic metabolic syndrome (MNMS): comparison of cooling and perfusion.

UNLABELLED: To evaluate the usefulness of cooling and perfusion methods for acute ischemic legs, we performed the experimental study using adult mongrel dogs. As creation of acute ischemic legs, the abdominal aorta was cross-clamped below the renal arteries, where all branches were ligated, for 6 hours. After release of clamp, the various parameters were examined for 18 hours. All dogs were divided into four groups according to the suppressive methods. CONTROL GROUP: cross-clamping for 6 hours with no suppressive method, Group 1: cooling legs using crushed ice during 6 hour-clamping, Group 2: perfusion by heparinized saline of 2.5-10.0 ml/kg before declamping, Group 3: cooling during latter half of 6-hour clamping and perfusion same as Group 2. The serum levels of metabolites and the tissue pressure of the thigh showed significantly lower in the suppression groups than CONTROL GROUP after declamping. In addition, GOT, CPK and aldolase revealed significantly lower values in Group 3 than Group 2. The tissue blood flow of the thigh recovered to the same extent as before ischemia in Groups 2 and 3, while it did not so in CONTROL GROUP and Group 1. Microscopic findings in hematoxylin and eosin (H-E) staining indicated a marked destruction of muscle fiber and interstitial edema in the striated muscle in CONTROL GROUP. These changes were not found so much in Group 2, and almost no changes in Group 1 and 3. The immunostaining for Mb in the striated muscle showed negative in CONTROL GROUP and Group 2, while it showed positive staining in Groups 1 and 3. The immunostaining for Mb in the kidneys showed the most dense deposits of Mb in the renal tubules in CONTROL GROUP. These changes were less in Group 2, little in Group 3, and no change in Group 1. In conclusions, cooling method revealed the minimal metabolic change, and combined method with perfusion was still more effective for prevention of MNMS.

Animals↗
PubMed1999

Assessment of left ventricular function using dobutamine stress echocardiography and myocardial scintigraphy in valvular heart disease.

To assess the left ventricular (LV) function in valvular heart disease, we employed the preoperative dobutamine stress echocardiography and the myocardial scintigraphy. During the past 13 years, 37 of 324 the patients showed LV dysfunction with the % fractional shortening (%FS) of 25% or less in the preoperative echocardiogram. These patients were retrospectively divided into two groups; Group A (n = 21): %FS has improved late after operation; Group B (n = 16): %FS has deteriorated or LV failure occurred. The mean follow-up period was 84 +/- 54 months after valve surgery. No significant differences were observed in the preoperative characteristics and operative variables between these two groups. The dobutamine stress test had been performed in 8 patients in Group A and 9 patients in Group B preoperatively, and the maximum increase ratio of %FS (delta %FS) was used for assessment. Seven patients in Group A had showed delta %FS of more than 9%, while all patients in Group B had showed delta %FS of less than 9%. Myocardial scintigraphy was performed in 11 patients of them, and another 22 patients with %FS of above 25% acted as the control group. The Defect Score, which was defined as the sum of defect scales in 25 LV segments, showed a significant difference between 11 patients with LV dysfunction and control group. The distribution of the Defect Score in each myocardial segment, showed significantly higher in the posterior and inferior LV segments. In addition, the perfusion defect on myocardial imaging was initiated in the junction between the septal and LV free wall, and extended from the posterior to the lateral wall along with deterioration of LV function. In conclusion, preoperative dobutamine stress echocardiography proved to be very useful for prediction of the postoperative LV function, and myocardial scintigraphy might be indicative of LV function even in valvular heart disease.

Adult↗
PubMed1999

Paramalleolar bypass concomitantly with extended endarterectomy for limb-threatening ischemia: A case report.

A 74-year-old male was admitted to our university hospital with a refractory ulcer of the left third toe. The ankle pressure index was 0.43. On his angiogram, the popliteal artery was totally occluded in the distal site, while the peroneal artery was solely patent and inflowed into the distal posterior tibial artery. At surgery, endarterectomy of 7 cm in length was performed on the tibioperoneal trunk of the occluded popliteal artery following patch repair using a saphenous vein to restore the genicular arterial network and infrapopliteal arteries. Thereafter, the bypass surgery was performed using the in situ saphenous vein from the patent proximal popliteal artery to the distal posterior tibial artery. The postoperative angiogram showed patency of the graft as well as restoration of the genicular arterial network and infrapopliteal arteries. The ankle pressure index improved to 1.04, and the refractory ulcer was completely cured one month after revascularization.

Aged↗
PubMed1999

Analysis of mutant p53 and telomerase activity in non-small cell lung cancer.

The number of mutant p53 protein-positive tumor cells in primary non-small cell lung carcinoma (NSCLC) cases were quantitated by flow cytometry (FCM) and the relationships of these data to various factors were evaluated. Furthermore, the method of quantitating telomerase activity was investigated. Forty patients with primary lung carcinoma encountered between December 1995 and December 1997 were investigated. Among these cases, telomerase activity was measured. Using PAb421, cells were reacted with fluorescent antibody and fluorescence was quantitated by FCM. Fluorescence index (FI) was estimated in relation to the positivity rates of negative controls and were quantitatively evaluated. FI values of normal lung tissue were obtained from normal lung tissue excised from young patients with pulmonary bulla. Values that were 2SD or more above the mean value of normal lung tissue (> 2.19) were regarded as mutant p53-positive, and 14 (35.0%) of 40 lung carcinoma cases were positive by this criterion. Of 13 poorly differentiated carcinoma cases, seven cases (53.8%) were positive, which was significantly high. Furthermore, the telomerase activity was converted to numerical values in 40 cases using the telomelic repeat amplication protocol (TRAP) method as well as the total product generated (TPG) method. The mean TPG value of the 40 cases was 75.21 +/- 15.63. Among these cases, the mean value of fourteen p53-positive cases was 124.49 +/- 37.19, which was higher than that of 26 negative cases, 48.68 +/- 10.88, showing a significant difference. The method used in this study was considered a useful method that allows accurate and objective evaluation of mutant p53 expression. It was suggested that mutant p53 expression may affect the degree of tumor cell differentiation. Consequently, it was confirmed in this study that mutant p53 expression and telomerase activity were closely associated in lung cancer.

Aged↗