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Biomedical subjects

M Ando

Publications and source records attributed to M Ando.

At least 145 records · Page 8Linked to original sources

Valved conduit operation for aortic regurgitation associated with Behçet's disease.

OBJECTIVES: Aortic regurgitation associated with Behçet's disease is rare, and prosthetic valve detachment after aortic valve replacement is one of the most serious complications reported. We have investigated the surgical results of valved conduit operation in 8 patients. METHODS: Between 1987 and April 1999, 8 patients underwent surgery. There were 7 males and 1 female, and their ages ranged from 33 to 60 years (mean, 48 +/- 10 years). The valved conduit procedure was a modified Bentall operation. RESULTS: One patient died of arrhythmia during the hospital stay. The follow-up period in the other 7 patients ranged from 1 to 138 months after surgery (mean, 74 months). None of these 7 patients died during the follow-up period. Valve detachment needing redo-operation occurred in 1 patient, and he underwent a valved conduit operation again. CONCLUSIONS: Valved conduit reconstruction is indicated in patients with aortic regurgitation caused by Behçet's disease, in whom prevention of valve detachment is difficult even by current valve fixation methods.

Adult↗

Infective endocarditis affecting both systemic and pulmonary circulations predisposed by a ventricular septal defect.

A 39-year-old woman was admitted to our hospital presenting persisting fever. An echocardiographic examination showed severe aortic and mitral valve regurgitation with moderate tricuspid regurgitation. Small left-to-right shunt through the ventricular septal defect was identified. Vegetation was also detected on the tricuspid, mitral, and aortic valves. At one month after admission, the patient showed sudden onset of headache and abdominal pain. A computed tomographic scan demonstrated cerebral and splenic infarction. A pulmonary perfusion scintigram demonstrated perfusion defects in left-S1 and right-S6 regions. At 4 months after admission, as operation was performed. The aortic valve was replaced with a #23 mm CarboMedics prosthesis and the mitral valve with a #29 mm Carbo Medics prosthesis. Tricuspid valve plasty was performed, with closure of He laceration and perforation of the anterior leaflet combined with a commissuroplasty, according to Kay's method. Ventricular septal defect was closed with a bovine pericardial patch. She was discharged at 19 days after the operation, and is leading a good life. Pervasion of the organism seemed to be initiated from the mitral valve which was conveyed by the blood stream to the aortic valve, and to the tricuspid valve through the ventricula septal defect. Left heart evaluation may be important in cases with infective endocarditis and ventricula septal defect.

Adult↗

Scaphoid nonunion treated by open reduction, anterior inlay bone grafting, and Kirschner-wire fixation.

Forty-three patients with ununited fractures of the scaphoid were treated by open reduction, anterior inlay bone grafting and Kirschner wire fixation. All but one achieved bone union. The one failure was successfully treated with a second anterior inlay bone grafting procedure. The average period of cast immobilization was 7 weeks. The presence of an unstable nonunion did not adversely affect the results. In cases with carpal instability, we used a longer corticocancellous graft to restore a more normal alignment of the scaphoid by opening up the volar cortex. Preoperatively, carpal instability was present in 25 patients. In these cases, carpal alignment demonstrated by the radiolunate and scapholunate angle was improved significantly after surgery: the radiolunate angle from 15 degrees before surgery to 2 degrees after surgery, and the scapholunate angle from 67 degrees to 54 degrees, respectively. Pain, restricted motion of the wrist, and the grip strength were improved after surgery.

Adolescent↗

Operative treatment of mallet finger due to intra-articular fracture of the distal phalanx.

Treatment of a mallet finger due to an intra-articular fracture of the distal phalanx involving one-third or more of the articular surface is controversial. Thirty-three digits with such fractures were treated by open reduction and internal fixation with Kirschner wires. Of these 33 fractures, 13 were associated with subluxation of the distal phalanx. After an average follow-up period of 29 months, the average loss of extension of the distal phalanx was 4 degrees, and the average flexion of the distal interphalangeal joint was 67 degrees. Radiographs of the distal joint in 27 digits appeared normal, while in the remaining 6 digits, slight degenerative changes were noted. In one there was a minor surgical complication. By using the operative technique described, a congruous reduction of the inta-articular fracture and satisfactory function were achieved.

Adolescent↗

Assessment of renal toxicity by analysis of regeneration of tubular epithelium in rats given low-dose cadmium chloride or cadmium-polluted rice for 22 months.

To determine whether low-dose oral administration of cadmium (Cd) induces renal toxicity, six groups of female Sprague-Dawley rats were fed a diet containing low amounts of CdCl2 or Cd-polluted rice at concentrations up to 40 ppm, and were killed after 12, 18, and 22 months (experiment 1). In addition to the determination of cortical Cd levels and histopathological assessment of kidneys, labeling indices (LIs) for proliferating cell nuclear antigen (PCNA) in the renal cortical tubular epithelium of Cd-treated rats were determined as a measure of regenerative activity. For comparison, the kidneys of rats given diets containing small to large amounts of CdCl2 up to 600 ppm for 4 months were similarly examined (experiment 2). Animals in experiment 1 demonstrated spontaneous chronic nephropathy and fluctuation in the tubular PCNA LI, but these findings were not correlated with renal Cd levels at 22 months. PCNA LI on the other hand, appeared to be linked to the severity of chronic nephropathy. In experiment 2, levels of CdCl2 of 200 ppm or more clearly induced degeneration and apoptosis of proximal tubules with high correlations between renal Cd levels, PCNA LI, and the severity of tubular degeneration. The results demonstrated that, in contrast to high-dose Cd administration, treatment with 40 ppm or less for 22 months did not influence tubular regeneration as a component of nonspecific chronic nephropathy, suggesting that long-term oral administration of low levels of Cd does not injure renal tubules in female rats.

Animals↗

Effect of 4-tert-octylphenol on cytochrome P450 enzymes in rat liver.

The effects were studied of 4-tert-octylphenol (OP) on hepatic cytochrome P450 enzymes in rats. Rats were treated intraperitoneally with OP twice, at doses of 5, 10, and 20 mg/kg. Among the cytochrome P450-dependent monooxygenase activities, testosterone 2alpha-hydroxylase activity, which is associated with CYP2C11, was significantly decreased by OP at all doses. The level relative to control activity was 67-22%. CYP3A2-dependent monooxygenase, testosterone 6beta-hydroxylase activity was also decreased by 51% by OP at 20 mg/kg. Furthermore, immunoblotting showed that OP (10 or 20 mg/kg) significantly decreased CYP2C11/6 and CYP3A2/1 protein levels. However, the reduction ratio of CYP2C11/6 and CYP3A2/1 protein levels by OP treatment was lower than that of testosterone 2alpha-hydroxylase and testosterone 6beta-hydroxylase activities. The Cl(int) (Vmax/Km) value for testosterone 2alpha-hydroxylase was significantly decreased by OP at all doses, whereas the Cl(int) value for testosterone 6beta-hydroxylase was only decreased by OP at 20 mg/kg. In addition, 7-ethoxycoumarin O-deethylase activity was significantly decreased by 32% by the highest dose of OP. By contrast, CYP1A1-, CYP1A2-, CYP2A1-, CYP2B1/2-, CYP2D1-, CYP2E1- and CYP4A1/2/3-dependent monooxygenase activities were not affected by OP at any dose. These results suggest that OP changes the male-specific cytochrome P450 isoforms in rat liver, and that these changes closely relate to the toxicity of OP.

Animals↗

Bone grafting in cementless total hip replacement for congenital dysplasia of the hip.

We reviewed 27 cementless primary total hip replacements in patients with osteoarthrosis secondary to congenital dysplasia of the hip. Autogenous bone grafting was used as augmentation. On average the follow-up period was 9 years. Two hips were revised and three acetabular components were considered loose. In hips with loose cups the average graft coverage was significantly greater than in stable hips. The use of a cementless acetabular component is encouraging for reconstruction, although extensive grafting should be avoided. Our study suggests that cementless reconstruction in dysplastic hips yields a satisfactory outcome.

Adult↗

Simultaneous double interphalangeal dislocation in one finger.

Isolated dislocation of the proximal or distal interphalangeal joint of a finger is common, but simultaneous dislocation of both joints is rare. Three cases of simultaneous dislocations of both interphalangeal joints in the same finger are reported. Closed reduction was easily achieved in all cases.

Adult↗

Assessment of intestinal viability using a non-contact laser tissue blood flowmeter.

BACKGROUND: Intraoperative assessment of small intestinal viability following ischemic insult from arterial occlusion has remained difficult. The purpose of the present study was to assess the applicability of non-contact tissue blood flowmeter (NCLBF) with regard to intraoperative assessment of intestinal viability. METHODS: Using the ischemia-reperfusion model of rabbits, the relationship between the records of NCLBF, pulse oximetry (PO), and histological grade and the comparison of accuracy of intestinal viability among NCLBF, PO, and fluorescein (FL) were examined. RESULTS: There was a significant relationship between NCLBF and the histological grade (coefficient-0.80, P <0.0001); however, PO was not related. The accuracy and sensitivity of bowel viability of NCLBF (76%, 88%) were better than those of PO (58%, 23%) and FL (48%, 4%), respectively (P <0.001). CONCLUSIONS: NCLBF is useful to assess intestinal viability, suggesting the possibility of clinical use.

Animals↗

Mechanism generating endocochlear potential: role played by intermediate cells in stria vascularis.

The endocochlear DC potential (EP) is generated by the stria vascularis, and essential for the normal function of hair cells. Intermediate cells are melanocytes in the stria vascularis. To examine the contribution of the membrane potential of intermediate cells (E(m)) to the EP, a comparison was made between the effects of K(+) channel blockers on the E(m) and those on the EP. The E(m) of dissociated guinea pig intermediate cells was measured in the zero-current clamp mode of the whole-cell patch clamp configuration. The E(m) changed by 55.1 mV per 10-fold changes in extracellular K(+) concentration. Ba(2+), Cs(+), and quinine depressed the E(m) in a dose-dependent manner, whereas tetraethylammonium at 30 mM and 4-aminopyridine at 10 mM had no effect. The reduction of the E(m) by Ba(2+) and Cs(+) was enhanced by lowering the extracellular K(+) concentration from 3.6 mM to 1.2 mM. To examine the effect of the K(+) channel blockers on the EP, the EP of guinea pigs was maintained by vascular perfusion, and K(+) channel blockers were administered to the artificial blood. Ba(2+), Cs(+) and quinine depressed the EP in a dose-dependent manner, whereas tetraethylammonium at 30 mM and 4-aminopyridine at 10 mM did not change the EP. A 10-fold increase in the K(+) concentration in the artificial blood caused a minor decrease in the EP of only 10.6 mV. The changes in the EP were similar to those seen in the E(m) obtained at the lower extracellular K(+) concentration of 1.2 mM. On the basis of these results, we propose that the EP is critically dependent on the voltage jump across the plasma membrane of intermediate cells, and that K(+) concentration in the intercellular space in the stria vascularis may be actively controlled at a concentration lower than the plasma level.

4-Aminopyridine↗

Interaction of bisphenol A with rat hepatic cytochrome P450 enzymes.

The effect of bisphenol A (BPA) on the kinetics of cytochrome P450 (P450)-dependent monooxygenases in rat liver microsomes was studied. Testosterone 16beta-hydroxylase (TS16BH) and testosterone 2alpha-hydroxylase (TS2AH) activities were extensively inhibited by BPA at 100 microM (69% and 74%, respectively). The inhibition type was mixed for both P450-dependent monooxyganases. The Ki of TS16BH and TS2AH from Lineweaver-Burk plots were 25.9 and 24.9 microM, respectively. The activities of acetanilide 4-hydroxylase (AA4H), 7-ethoxycoumarin O-deethylase (ECOD), bufuralol 1'-hydroxylase (BF1'H), chlorzoxazone 6-hydroxylase (CZ6H) and testosterone 6beta-hydroxylase (TS6BH) were also effectively inhibited by BPA at 100 microM (43-52%). The inhibition type of these P450-dependent monooxygenases was mixed or uncompetitive, and the K(i)s (50.5-88.5 microM) were higher than those of TS16BH and TS2AH. By contrast, the values of IC50 and Ki of testosterone 7alpha-hydroxylase (TS7AH) and lauric acid omega-hydroxylase (LAOH) for BPA were >1000 microM. These results suggest that BPA interacts with rat hepatic CYP1A2, CYP2A2, CYP2B2, CYP2C11, CYP2D1, CYP2E1 and CYP3A2 in vitro.

Air Pollutants, Occupational↗

Three-channeled aortic dissection in Marfan syndrome.

Among the various types of aortic dissection, three-channeled aortic dissection, in which two adjacent false lumens are present, is rarely observed. The authors surgically treated 20 Marfan syndrome patients with this type of dissection, who accounted for 29.4% of 68 patients with aortic dissection in Marfan syndrome and who were surgically treated in the authors' institution prior to July 1999. Patient age ranged from 24 to 51 years (mean of 40 years). The male:female ratio was 13:7. Valved conduit procedure had been performed previously in 14 patients. Pain was observed at various times in 13 patients. Computed tomography scanning and magnetic resonance imaging were useful for preoperative diagnosis. The morphology of the first and second false lumens was Stanford type A + type B in 10 patients and type B + type B in 10 patients. Re-entry of the second false lumen was observed in five patients. The descending aorta was replaced in 13 patients, thoracoabdominal aortic replacement was performed in five, extra-anatomic bypass in one patient and iliac artery-superior mesenteric artery bypass in one. Four patients died in hospital. There were three late deaths during a follow-up of 1-208 months (mean of 51 months). When pain recurs in Marfan patients with aortic dissection, three-channeled dissection should be suspected and subsequent surgery is required. The incidence of this dissection is high in patients with Marfan syndrome.

Adult↗

Preoperative demonstration of the Adamkiewicz artery by magnetic resonance angiography in patients with descending or thoracoabdominal aortic aneurysms.

OBJECTIVE: Investigating the possibility of magnetic resonance angiography (MRA) to visualize the Adamkiewicz artery of as a preoperative study of thoracic aortic aneurysms. METHODS: From February 1998 to March 1999, 26 consecutive patients who had aneurysms of the thoracoabdominal or descending aorta underwent preoperative MRA to visualize the Adamkiewicz artery. Mean age was 60.5+/-11.5 years. Fifteen patients had non-dissecting aneurysm and 11 had aortic dissections. Nineteen patients underwent replacement of the aneurysms, four patients underwent endovascular stent-graft repair, and three patients were discharged without treatment of aneurysm. MRA was performed on a 1.5-T system (Magnetom, Siemens) and data acquisition was repeated two times following injection of gadolinium-DTPA. Source images were reconstructed with multiplanar reconstruction and maximum intensity projection. Criteria for the Adamkiewicz artery of were that the artery ascends from the dorsal branch of the intercostal or lumbar artery to the anterior mid-sagital surface of the spinal cord in the early phase. RESULTS: The Adamkiewicz arteries were demonstrated in 18 patients (69%). These arteries were originated from the left intercostal or lumbar arteries in 13 (72.2%) patients and from the right in 5 (27.8%) and from the Th8 branch in three, Th9 in seven, Th10 in two, Th11 in four, and L1 in two. All patients had graft replacement of the aorta using a partial bypass. All intercostal or lumber arteries, which were visualized as the origin of the Adamkiewicz artery, were reattached to the grafts. No spinal cord injury occurred. CONCLUSION: Preoperative detection the Adamkiewicz artery was possible by MRA and was very useful to reduce the incidence of ischemic injury of the spinal cord during surgery of the thoracoabdominal or descending aorta.

Adult↗

Psychological distress following first recurrence of disease in patients with breast cancer: prevalence and risk factors.

OBJECTIVES: To investigate the prevalence of and risk factors for psychological distress following first recurrences of breast cancer. PATIENTS AND METHODS: The sample was drawn consecutively from the inpatient and outpatient populations of the National Cancer Center Hospital in Japan during an 18-month period from July 1996 to December 1997. Of the 56 eligible patients, 55 women aged 30-73 year with recurrent breast cancer participated in the study. The prevalence of psychological distress, including major depressive disorder and adjustment disorders was evaluated according to the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Third edition-revised (DSM-III-R). Risk factors for psychological distress were analyzed with a logistic regression model. RESULTS: Of the 55 subjects, 42% met the DSM-III-R criteria for major depressive disorder or adjustment disorders. Major depressive disorder was seen in 4 (7%), and adjustment disorders in 19 (35%). Logistic regression analysis showed that a disease-free interval of less than 24 months significantly predicted a diagnosis of major depressive disorder or adjustment disorders (odds ratio 5.28, 95% confidence interval; 1.28-21.8, p = 0.02). CONCLUSIONS: These results suggest that it is important for all oncology staff to pay careful attention to the psychological health of patients who have been informed of their cancer recurrence, and that some psychosocial intervention is necessary for preventing distress in patients facing early recurrence.

Adjustment Disorders↗