Biomedical subjects

Y Tada

Publications and source records attributed to Y Tada.

395 records · Page 22Linked to original sources

PubMedDate not supplied

Thiabendazole (TBZ) nephrotoxicity and recovery in ICR adult mice.

The nephrotoxicity and recovery following administration of thiabendazole (TBZ) were investigated in ICR adult mice. A single oral administration of TBZ (500-2000 mg/kg body wt.) caused a dose-dependent proximal tubular necrosis in the kidney and increase in serum urea nitrogen 24 h after dosing. These changes were marked in mice of high dose groups (1000 or 2000 mg TBZ/kg body wt.). The time course of changes on kidney of mice treated with 1000 or 2000 mg TBZ/kg body weight were examined at 1, 2, 3, 5, 7 or 10 days after dosing. Light microscopy showed necrosis of proximal convoluted tubules from 1 day after dosing. Tubular necrosis was extensive 2 or 3 days after dosing. Partial regeneration from tubular necrosis was seen 3 days after dosing, and substantial regeneration had occurred from 5 days after dosing. Thus, TBZ-induced renal injury was most severe at 2 or 3 days after dosing and was followed by regeneration. Electron microscopy showed swelling of mitochondria in the proximal tubular epithelium at 1 day after dosing. The pathological changes were correlated with the changes in urinalysis, serum urea nitrogen concentration and kidney weight.

Administration, Oral↗

PubMedDate not supplied

Effects of thiabendazole (TBZ) on mitochondrial function in renal cortex of ICR mice.

The effects of thiabendazole (TBZ) on mitochondrial function of the renal cortex were investigated in ICR mice. Mice were given 1000 or 2000 mg TBZ/kg body weight by gavage and mitochondria were isolated from the renal cortex for the measurement of respiratory rates. The state 3 and DNP-uncoupled respiratory rates of renal cortical mitochondria were dose-dependently depressed at 6 hours after dosing. The depression of these respiratory rates of renal cortical mitochondria was more marked at 16 hours after dosing. There was no depression in these respiratory rates of renal cortical mitochondria at 3 hours after dosing, although renal cortical concentrations of TBZ were higher than those at 6 or 16 hours after dosing. Histochemical examination revealed that NAD-linked isocitrate dehydrogenase, a marker enzyme of mitochondria, was inhibited in renal cortical tubules at 16 hours after dosing of 1000 or 2000 mg TBZ/kg body weight. Furthermore, renal cortical ATP level was significantly decreased at 16 hours after dosing of 1000 or 2000 mg TBZ/kg body weight. The results indicate that administration of TBZ caused mitochondrial dysfunction in renal cortical tubules of mice.

Adenosine Triphosphate↗

PubMedDate not supplied

CT detection of facial canal dehiscence and semicircular canal fistula: comparison with surgical findings.

OBJECTIVE: The purpose of this study was to determine the accuracy of high resolution CT (HRCT) in the detection of facial canal dehiscence and semicircular canal fistula, the preoperative evaluation of both of which is clinically very important for ear surgery. MATERIALS AND METHODS: We retrospectively reviewed the HRCT findings in 61 patients who underwent mastoidectomy at Yamagata University between 1989 and 1993. The HRCT images were obtained in the axial and semicoronal planes using 1 mm slice thickness and 1 mm intersection gap. RESULTS: In 46 (75%) of the 61 patients, the HRCT image-based assessment of the facial canal dehiscence coincided with the surgical findings. The data for the facial canal revealed sensitivity of 66% and specificity of 84%. For semicircular canal fistula, in 59 (97%) of the 61 patients, the HRCT image-based assessment and the surgical findings coincided. The image-based assessment in the remaining two patients, who both had massive cholesteatoma, was false-positive. CONCLUSION: HRCT is useful in the diagnosis of facial canal dehiscence and labyrinthine fistula, but its limitations should also be recognized.

Adolescent↗

PubMedDate not supplied

3,5-diacetyl-1,4-dihydropyridines: synthesis and MDR reversal in tumor cells.

Eleven 4-phenyl-3,5-diacetyl-1,4-dihydropyridines (AcDHPs) [G1-11] substituted at the phenyl ring were synthesized and compared for their cytotoxic activity and multidrug resistance (MDR)-reversing activity in in vitro assay systems. Among them, compound [G7] showed the highest cytotoxic activity against human promyelocytic leukemia HL-60 and human squamous cell carcinoma HSC-2 cells. However, no compounds tested produced radicals at pH 7.4-12.5. The activity of P-glycoprotein (Pgp) responsible for MDR in tumor cells was reduced by compounds [G2, 3, 6, 5, 8, 1, 11], verapamil [VP] and nifedipine [NP]. However, compounds [G4, 7, 10] were hardly active while G9 did not show a MDR reversing effect at 2.0-20.0 micrograms/mL. These data show a relationship between chemical structures and MDR-reversing effect on tumor cells.

Antineoplastic Agents↗

PubMedDate not supplied

False aneurysms after aortic operations.

Between 1980 and August 1991, we encountered 11 non-infected aortic pseudoaneurysms after aortic surgery. The interval between the initial operation and revision varied from 1.8 to 26.8 years (mean 15.2 years). Three were found more than 20 years after operation. Pulling off of and degrading of the silk sutures were considered to be the causes. All patients underwent operative correction without mortality. In thoracic aortic pseudoaneurysm repair, a temporary bypass between the right axillary artery and left external iliac artery was generally adopted. There was no need for heparinization with this technique.

Adult↗

PubMedDate not supplied

Esmarch's bandage technique in distal bypass surgery.

Esmarch's rubber bandage technique has been applied to 49 distal bypass surgeries in 46 patients during the past ten years. The primary and secondary patency rates at 5 years after femoro-tibial bypass surgery were 82% and 92%, respectively. This technique has the following advantages: (1) it minimizes surgical injury of the arterial wall because there is less dissection around the anastomotic site; (2) it decreases scar formation in the anastomotic area after surgery; (3) it maintains abundant muscular blood flow by preserving small branches to muscles, and (4) it provides a bloodless surgical field and easy handling for fine sutures without using vascular clamps. We consider that the avoidance of long circumferential dissection of the artery may play an important role in improving long-term patency in distal bypass surgery.

Adult↗

PubMedDate not supplied

The association of Behçet's disease with myelodysplastic syndrome in Japan: a review of the literature.

OBJECTIVE: [corrected] To determine the clinical characteristics of patients with myelodysplastic syndrome (MDS)-associated Behçet's disease (BD) in Japan. METHODS: 54 Japanese cases of MDS-associated BD obtained from the literature and from our own clinical experience were reviewed. The clinical features of MDS-associated BD were compared with those of the 1991 nationwide BD survey in Japan. RESULTS: In MDS-associated BD, the average age at onset was 42.6 years, which was 6.9 years later than for all BD patients; females developed disease more frequently than males (male: female ratio = 0.80). In MDS-associated BD cases, the occurrence of eye lesions was significantly lower, the frequency of intestinal lesions was markedly higher, and the rate of HLA-B51 positivity was lower than that in all BD. BD and MDS developed nearly simultaneously in 49.0% of cases; BD preceded MDS in 31.4% of the cases. The distribution of the age at BD onset showed two peaks, one in the 3rd decade and the other in the 6th decade. Females were more likely to develop younger-onset disease, while men were more likely to develop older-onset MDS-associated BD. Furthermore, in the older-onset group, BD was diagnosed together with or after the diagnosis of MDS, while half of the younger-onset group developed BD earlier than MDS. CONCLUSION: MDS-associated BD patients form a distinct subset of patients. There may, in fact, be two major groups of MDS-associated BD patients based on age, gender, and temporal relationship of the two diseases.

Adolescent↗

PubMedDate not supplied

Measurement of peritoneal dialysate volume by CT.

Three-dimensional (3-D) graphic reconstruction of serial image data of x-ray CT on three dialysis patients was studied to measure peritoneal dialysate (PD) volume. Volume estimation with a surface reconstructed model provided a 16% error; a 35% error was found with a voxel model, although the total time required by the voxel model was 15 times less.

Aged↗

PubMedDate not supplied

Carotid artery pseudoaneurysm following internal jugular vein cannulation.

A case of right common carotid artery pseudoaneurysm following internal jugular vein cannulation is reported. The aneurysm appeared three days after removal of the catheter, which had been in the right internal jugular vein for three weeks. There was a pin-hole communication between the common carotid artery and the pseudoaneurysm, which was successfully obliterated by surgery. Carotid pseudoaneurysm formation is a rare complication of internal jugular vein cannulation, and there has been no report of its formation after apparently successful jugular vein cannulation. This complication is difficult to predict, and careful observation after removal of the catheter is mandatory.

Aged↗

PubMedDate not supplied

Surgical treatment for Takayasu's arteritis. A long-term follow-up study.

Thirty patients with Takayasu's arteritis treated surgically were followed for more than ten years postoperatively, 28 women and 2 men. The average age at the initial operation was 29 years. The clinicopathological finding was classified in four types; the distribution of cases was 6 in Type I, 17 in Type II, 4 in Type III, and 3 in Type IV. Surgical procedures performed were carotid artery reconstruction in 9 patients, thoraco-abdominal aortic bypass in 5, renal artery reconstruction in 10, combined procedures in 2, aneurysmectomy in 2, and other procedures in 2 patients. Twenty-six patients survived; four died during the study period. Twenty-three patients (77%) are well with good function of the reconstructed arteries. Six women had safe deliveries after successful operations. However, anastomotic false aneurysms occurred in 5 patients. The surgical management of Takayasu's arteritis must be distinguished from that of atherosclerotic vascular disease.

Adult↗

PubMedDate not supplied

Surgical treatment of non-specific inflammatory arterial aneurysms.

In the past thirty years, fifty arterial aneurysms due to non-specific inflammation in forty-two patients were operated on. Twenty-five patients were males and 17 were females; their average age was 38 years. The majority of the aneurysms were located in the abdominal aorta, common carotid artery, and femoral artery. Clinical diagnoses were Takayasu's disease (11), Behçet's disease (3), giant cell aortitis (2), and systemic lupus erythematosus (1). The other twenty-five cases were of undetermined etiology. There were fourteen cases of rupture, and long-term steroid administration in five cases was suspected of playing a major role in inducing this grave sequel. Aneurysmectomy with arterial reconstruction was performed on 37 cases. Various histological findings of inflammation were observed in the resected specimens. The suture aneurysms occurred in eight cases in the late period. Surgical care of non-specific inflammatory arterial aneurysms was judged to be more difficult than that of atherosclerotic aneurysms.

Adolescent↗

PubMedDate not supplied

Disseminated intravascular coagulation caused by abdominal aortic aneurysm.

A 71-year-old male with disseminated intravascular coagulation (DIC) caused by abdominal aortic aneurysm was successfully treated surgically. He had aortic regurgitation, an old myocardial infarction, and nephrotic syndrome. The infrarenal part of the inferior vena cava, which was on the left side of the aneurysm, was temporarily transected during the surgical procedure. Preoperative heparin therapy was insufficient, but infusion of blood components during the operation and minimal dissection of the aneurysm were effective in controlling intraoperative hemorrhage. Hypofibrinogenemia and thrombocytopenia were normalized immediately after operation, and hemorrhagic diathesis was completely cured. In this case, the definitive treatment of DIC caused by an abdominal aortic aneurysm war removal of the lesion and the infusion of coagulation factors during the operation was effective in minimizing blood loss.

Aged↗

PubMedDate not supplied

Clinical applications of Ga-67 DFO-DAS-fibrinogen.

Ga-67 DFO-DAS-fibrinogen scanning was performed in 15 patients to detect fresh arterial thrombus. Seven patients were preoperative cases of aortic aneurysm and eight were postoperative cases of graft bypass. Scanning was performed on the first and second days after the injection. Nine of 13 grafts in eight cases were visualized by 67Ga-DFO-DAS-fibrinogen scan. Velour Dacron grafts were more strongly visualized compared with woven Dacron or Goatex. In three patients with aortic aneurysm in whom fresh thrombus was identified by operative findings, arterial thrombus was clearly visualized by 67Ga-DFO-DAS-fibrinogen scan, whereas in three other patients with aortic aneurysm, thrombus was not visualized, although it was identified by other examinations. In one case, a marked accumulation was observed in the abdominal aorta, although no arterial thrombus was found at operation. This was thought to be an accumulation in a blood pool because it decreased on the second day. We think it important to observe the relative changes of accumulation.

Adult↗

PubMedDate not supplied

University of Wisconsin solution provides superior myocardial preservation compared with Stanford cardioplegic solution.

The efficacy of the University of Wisconsin solution to safely prolong preservation times for kidney, pancreas, and liver transplantation is established, but its efficacy in enhancing myocardial preservation is not yet clear. We studied the effects of Stanford cardioplegic solution and the University of Wisconsin solution both in preserving the myocardium and in protecting it from the effects of reperfusion injury after 6 hours of preservation. In 28 rat hearts we measured changes in high-energy phosphate content (with magnetic resonance spectroscopy) and histologic changes (edema, endothelial changes, myocyte architecture) during preservation and changes in high-energy phosphate content, histologic status, and performance (aortic systolic and diastolic pressure, heart rate, rhythm) in Langendorff and working hearts during reperfusion. No significant differences in the kinetics of high-energy phosphate changes were noted between the two cardioplegic solutions during preservation. However, at the end of 6 hours of preservation, hearts in the Stanford cardioplegic solution group were more edematous (p < 0.01) than those in the University of Wisconsin group. During reperfusion, no significant differences in the kinetics of high-energy phosphates were noted between the two cardioplegic solutions. None of the hearts in the University of Wisconsin solution group developed ventricular fibrillation at the start of reperfusion, but all hearts in the Stanford group did so. Once sinus rhythm was established no significant differences in developed pressure or heart rate were found between the two solutions. After 2.5 hours of reperfusion, hearts in the Stanford group were more edematous (p < 0.002) and had a greater disruption of myocyte architecture (p < 0.002) and greater arteriolar endothelial injury (p < 0.004). In conclusion, the University of Wisconsin solution better protects the myocardium in this rat model than does Stanford solution. The mechanism for this beneficial effect of the University of Wisconsin solution appears to be due to its better preservation of the microvasculature rather than differences in preservation of high-energy phosphates.

Adenosine↗

PubMedDate not supplied

Perianastomotic findings in canine endothelial cell seeded grafts at 3 months.

Endothelial cell seeding is one of the methods commonly used to prepare an antithrombogenic surface for small caliber vascular prostheses. In this study, we investigated the perianastomotic tissue reaction of seeded grafts, using a canine model. Eight dogs were used to harvest endothelial cells (ECs) enzymatically from their external jugular veins, with one dog being excluded because of infection. ECs were cultured and seeded, using a rotation method, onto a small caliber prosthesis woven with ultrafine polyester fibers. Each graft was implanted into the carotid artery of its cell donor dog, with another implanted contralaterally as a non seeded control. Two of seven seeded grafts were patent at 3 months, while all controls were occluded. Histologic examination revealed a continuous lining of ECs in the patent grafts, but thickening of the intima at the anastomoses was also observed. The occluded seeded grafts had organized hard thrombi and thick fibrosis at the perianastomotic area, however, with few thrombi in the midportion. These observations suggest that the investigation of a small caliber prosthesis with the ultimate aim of producing better patency should focus not only on antithrombogenicity of the surface of the lumen, but also on the perianastomotic biologic reaction.

Animals↗

PubMedDate not supplied

A reduction in accelerated graft coronary disease and an improvement in cardiac allograft survival using low molecular weight heparin in combination with cyclosporine.

Heparin compounds are a complex mixture of mucopolysaccharides that, in addition to their anticoagulant properties, have immunosuppressive activities and affect the reparative aspects of the response to arterial injury. Heparin inhibits smooth muscle cell migration and proliferation and can alter the accumulation of the components of the extracellular matrix after arterial injury. Heparin also interacts specifically with the endothelium. Our hypothesis was that if heparin compounds do affect the immune system, coagulation, smooth muscle cell proliferation, and the endothelium, then heparin combined with cyclosporine should improve allograft survival, reduce rejection, and prevent accelerated graft coronary disease. Low molecular-weight heparins are derived from the larger molecular-weight unfractionated heparin. We chose to use low molecular-weight heparins because of their longer half-life, better bioavailability, and decreased incidence of induced thrombocytopenia and bleeding. With a rat intraabdominal heterotopic model of heart transplantation (Lewis-Brown Norway to Lewis), low molecular-weight heparin in combination with a low dose of cyclosporine (0.5 mg/kg/day) significantly improved allograft survival compared to controls and either low molecular-weight heparin or cyclosporine alone. Histologically, smooth muscle cells are an important cellular component of the lesions of accelerated graft coronary disease. In comparison to animals treated with cyclosporine alone (2 mg/kg/day), the addition of low molecular-weight heparin to cyclosporine (2 mg/kg/day) reduced the frequency and the severity of accelerated graft coronary disease and the extent of parenchymal rejection.

Abdomen↗

PubMedDate not supplied

Surgical treatment of dissecting aortic aneurysm. Twenty years' experience.

Early and late results of 40 cases of dissecting aortic aneurysm were reported. 1. Result of 6 cases with acute dissection was as follows: two of three surgical patients survived, whereas all three with drug therapy died. Surgical treatment is preferred for the dissection of the ascending aorta or the arch. Some problems of the postoperative morbidity were discussed: 2. Whether medically treated or surgically, chronic dissection of the descending aorta or the abdominal aorta had better prognosis than that of the other site. Chronic dissection with no saccular enlargement had good prognosis. More than 10 years survival is to be expected. The operative result for the chronic aortic dissection was poor, especially in case of the involved ascending aorta and arch. For the saccular enlargement of the pseudolumen wrapping method with or without the resection might be the preferable procedure to avoid early rupture.

Acute Disease↗