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Biomedical subjects

K Yasuda

Publications and source records attributed to K Yasuda.

At least 451 records · Page 25Linked to original sources
PubMed1997

Allelic losses on 18q21 are associated with progression and metastasis in human prostate cancer.

We analyzed normal/tumor DNA pairs obtained from 46 patients with prostate cancers (stage B, 16 cases; C, 10 cases; D1, 4 cases; and endocrine therapy-resistant cancer-death, 16 cases) for loss of heterozygosity using 32 microsatellite markers on chromosome 18. Seventeen of the 46 cases (37%) showed loss of heterozygosity (LOH) for at least one locus on the long arm. Detailed deletion mapping in these tumors identified a distinct commonly deleted region within a 5-cM interval in 18q21.1. There was a statistical correlation between the frequency of LOH on 18q and clinical stage (chi 2 = 12.3; P = 0.0064). LOH on 18q was observed more frequently in Stage D1 cases (4/4; 100%) than in stage B+C cases (5/26; 19%; P = 0.0046, Fisher's exact test). In 8 of 9 (89%) cancer-death patients from whom DNAs were available from both primary and metastatic tumors, the primary tumors had either no detectable abnormality of chromosome 18 or the region involving loss of heterozygosity was limited while the metastatic foci showed more frequent and extended allelic losses on this chromosome. No abnormalities were detected in the DCC and DPC4 genes when their exons were analyzed separately by single strand conformation polymorphism assay. These results suggest that inactivation of one or more putative tumor suppressor genes on 18q21 other than DCC and DPC4 plays an important role in the progression of human prostate cancer.

Adenocarcinoma↗
PubMed1997

Micturitional disturbance in Wernicke's encephalopathy.

A 24-year-old pregnant woman started to have hyperemesis gravidarum 6 weeks before admission. Four weeks later she had vertigo, diplopia, staggering gait, mild dyspnea, dysphagia, and incontinence of urine. On admission she presented with ophthalmoplegia, ptosis, ataxia, decreased tendon reflex, and memory disturbance. Brain magnetic resonance imaging revealed abnormal intensities in medial thalamic-hypothalamic regions and the periaqueductal area, and she was diagnosed with Wernicke's encephalopathy. Urodynamic studies revealed decreased bladder volume and detrusor hyperreflexia. Six weeks after the administration of 100 mg/day of thiamine, urge incontinence gradually recovered, together with neurological signs. Lesions of the medial thalamic-hypothalamic area and the periaqueductal gray matter seemed to be mainly responsible for micturitional disturbance in our patient with Wernicke's encephalopathy.

Adult↗
PubMed1997

Effects of in situ freezing and stress-shielding on the ultrastructure of rabbit patellar tendons.

The effects of in situ freezing and the combination of in situ freezing and stress-shielding on the microstructure and ultrastructure of the patellar tendon were studied with use of 20 mature rabbits. The patellar tendon was frozen in situ with liquid nitrogen to kill fibroblasts and then was completely released from stress by chronically pulling a stainless-steel wire installed between the patella and the tibial tubercle. Microstructurally, the freezing treatment induced separation of collagen fiber bundles and fibroblast necrosis at 3 weeks, although the separation disappeared at 6 weeks. Ultrastructurally, small collagen fibrils with a diameter of less than 90 nm were predominant; at 6 weeks, the area occupied by collagen fibrils had decreased. In the frozen-shielded tendon, numerous large spaces were observed in the matrix at 3 weeks. This treatment increased the number of fibrils with a diameter greater than 360 nm and decreased the number of collagen fibrils per unit of area and the area occupied by collagen fibrils at 3 weeks. This study demonstrated that in situ freezing and the combination of in situ freezing and stress-shielding leads to a smaller volume of collagen fibrils per unit of cross section of the patellar tendon by mechanisms that remain to be defined.

Animals↗
PubMed1997

Extensive replacement of the aorta from the ascending aorta to the supraceliac abdominal aorta during a one-stage operation.

A successful replacement of the aorta from the ascending aorta to the supraceliac abdominal aorta in one operation is herein reported. The patient was 66-year-old woman who had DeBakey type I chronic aortic dissection with a pre-disseminated intravascular coagulation (DIC) condition. The image diagnosis revealed a markedly enlarged false lumen with a narrow true lumen in the ascending aorta extending to the diaphragm level while below the diaphragm level, the aortic dilatation was mild. The operation was performed through both a thoracoabdominal incision and a median sternotomy to expose the whole thoracic aorta, and the aorta was replaced from the ascending aorta to the supraceliac abdominal aorta. Selective cerebral perfusion was used for cerebral protection and this was a useful adjunct since no time limitations were thus required during repair of the aortic arch. Although the patient developed several complications postoperatively, she eventually recovered and was discharged from the hospital without any neurological disorders.

Aged↗
PubMed1997

Urodynamic and cardiovascular measurements in patients with micturition syncope.

We describe the findings of urodynamic studies, together with blood pressure and heart rate monitoring, in five patients with micturition syncope. All patients had almost normal storage and evacuation function and no evidence of prostate hypertrophy. Conventional head-up tilt testing with an empty urinary bladder caused no change in arterial blood pressure, but a moderate increase in heart rate. Urinary bladder filling caused minimal increases of the arterial pressure and heart rate. The sitting posture with a distended bladder caused mild orthostatic hypotension. Urinary bladder evacuation caused a fall in arterial pressure with a decrease in heart rate. These responses were similar to those described in vasovagal syncope. The central mechanism for the initiation of urinary evacuation, or sensory input from the lower urinary tract, may trigger micturition syncope.

Adult↗
PubMed1997

The McCoy levering laryngoscope in patients with limited neck extension.

PURPOSE: The McCoy levering laryngoscope is a modified Macintosh laryngoscope, which has a hinged tip controlled by a lever on the handle. The purpose of this study was to investigate whether the tip elevation of this laryngoscope results in better laryngeal visualization than using the Macintosh laryngoscope when the patient's neck is fixed in the neutral position. METHODS: Fifty female patients (ASA physical status I-II) undergoing elective surgery during general anaesthesia were investigated. The patient's neck was manually fixed in the neutral position by an assistant, and laryngeal visualization was attempted first with a size #3 Macintosh laryngoscope (Macintosh trial), and then with a size #3 McCoy levering laryngoscope with blade tip elevation (McCoy trial), and tracheal intubation was attempted. Trials of laryngeal visualization were evaluated with the Cormack score. RESULTS: In the Macintosh trial, 36 of 50 (72%) patients were evaluated grade 3, and two grade 4. In most of the patients graded 2 and 3 in the Macintosh trial (70% of the grade 2 and 83% of the grade 3 cases), the laryngeal view was improved by using the McCoy levering laryngoscope. The Cormack grade in the McCoy trial was less than that in the Macintosh trial (P < 0.01). No complications were observed during the study. CONCLUSION: The McCoy levering laryngoscope improved laryngeal visualization in patients whose neck cannot be extended.

Female↗
PubMed1997

A mutation of the beta 3-adrenergic receptor is associated with visceral obesity but decreased serum triglyceride.

The Trp64Arg mutation of the beta 3-adrenergic receptor (beta 3AR) is prevalent in several ethnic groups and is associated with weight gain, and some features of syndrome X such as insulin resistance and dyslipidaemia. Nevertheless, it is not known at present whether this mutation is associated with visceral obesity, which is an important risk factor for the development of hypertension, dyslipidaemia, insulin resistance, non-insulin-dependent diabetes mellitus, and atherosclerosis. To investigate whether this mutation may contribute to visceral obesity, we studied the relationships between beta 3AR genotypes and clinical phenotypes. The Trp64Arg allele of beta 3AR was examined in 278 Japanese men with respect to variables relating to visceral obesity assessed by computerised tomography. To detect the Trp64Arg mutation, polymerase chain reaction-restriction fragment length polymorphism analysis using Bst NI digestion was performed. This mutation was more frequently observed in subjects with higher body mass index (BMI) (p = 0.02). Moreover, in 120 subjects with a moderate degree of obesity (22 < or = BMI < 26.4 kg/m2), the mutation (homozygotes and heterozygotes) was associated with visceral obesity (higher ratio of visceral to subcutaneous fat area; V/S) (p = 0.03). Furthermore, the Trp64Arg allele was more frequent in subjects with lower serum triglyceride levels (p = 0.02) and the Trp64Arg homozygotes, but not heterozygotes, exhibited lower triglyceride levels. Thus, this mutation appears to be associated with visceral obesity but with lower serum triglyceride. It is suggested that those with the mutation may describe a subset of subjects characterized by decreased lipolysis in visceral adipose tissue.

Adult↗
PubMed1997

Magnetic resonance imaging with fluid-attenuated inversion recovery pulse sequences in MELAS syndrome.

We report the brain magnetic resonance imaging findings in the case of a 5-year-old boy with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS). Fluid-attenuation inversion recovery (FLAIR) imaging revealed multifocal abnormal cortical signals which were difficult to see on conventional T1- and T2-weighted images. Although the patient was in an advanced clinical stage of disease and had severe cortical atrophy, FLAIR imaging demonstrated characteristic findings of MELAS.

Atrophy↗
PubMed1997

Aortic arch operation using selective cerebral perfusion for nondissecting thoracic aneurysm.

BACKGROUND: Risks of increasing mortality and disability in aortic arch operations using the selective cerebral perfusion method for nondissecting aneurysm have not yet been determined. A multicenter, retrospective study was employed. METHODS: The subjects were 143 patients who were admitted to one of the nine cardiovascular centers between January 1988 and December 1993, including 15 with ruptured aneurysm. A graft replacement of the transverse aortic arch or distal arch was performed in 80 patients, extensive aortic reconstruction comprising simultaneous replacement of the ascending or descending thoracic aorta (or both) in 46, and patch repair of involved arch in 17. The mean postoperative follow-up period was 19 months. RESULTS: Hospital mortality was 36/143 patients (25.2%). Univariate analysis revealed that age of 70 years or more, ruptured aneurysm, and renal dysfunction affected hospital mortality. Neurologic deficits were noted in 15 patients (10.5%). Reoperation was performed in 13 patients for residual distal aneurysm or false aneurysm. Late death occurred in 10 patients and were due to vascular complications in 6. Multivariate analysis confirmed that aneurysmal rupture and renal dysfunction were independent predictors for vascular death including hospital mortality. CONCLUSIONS: The present study confirmed that age, aneurysmal rupture, and renal dysfunction were significant predictors for mortality and disability in the aortic arch operation using selective cerebral perfusion for nondissecting thoracic aneurysm.

Aged↗
PubMed1997

Operation for nondissecting aneurysm in the descending thoracic aorta.

BACKGROUND: Little is known about the risks of mortality and morbidity after descending thoracic aortic aneurysm repair using left heart bypass and temporary arterioarterial bypass. METHODS: A multicenter, retrospective study was performed on 120 patients who were admitted to one of nine cardiovascular centers between January 1988 and December 1993 and underwent operation for nondissecting thoracic aortic aneurysm. The present series included 10 patients with ruptured aneurysm. Graft replacement was performed in 95 patients, patch repair in 22, and suture of the ruptured aorta in 3. Venoarterial bypass was used in 45 patients, left heart bypass in 56, and temporary arterioarterial bypass in 19 as circulatory support. The mean postoperative follow-up period was 30 +/- 21 months. RESULTS: Hospital mortality occurred in 7 patients (5.8%). Univariate analysis revealed that only aneurysmal rupture was related to hospital mortality. Brain or cord injury was observed in 4. Of nine deaths that occurred after discharge, five were related to aneurysm and two were due to vascular event. No significant difference was noticed in probability of survival according to the circulatory supporting method. Only aneurysmal rupture affected probability of survival. Multivariate analysis revealed that aneurysmal rupture was the only independent predictor for vascular death including hospital mortality. CONCLUSIONS: The present study confirms that aneurysmal rupture is a significant predictor for mortality and morbidity in aortic operations for nondissecting descending thoracic aneurysm, and that a similarly good outcome would be expected when using left heart bypass, temporary arterioarterial bypass, or venoarterial bypass.

Aged↗
PubMed1997

Interhead distances in myosin attached to F-actin estimated by fluorescence energy transfer spectroscopy.

Fluorescence resonance energy transfer (FRET) spectroscopy has been used to determine distances between probes attached to the most reactive sulfhydryl (SH1) group on individual myosin "heads." We measured intramolecular and intermolecular interhead distances as well as the distance between one head of heavy meromyosin (HMM) mixed with subfragment-1 (S1) heads attached to F-actin under rigor conditions. The SH1 cysteine was specifically labeled with either a donor (5-((((2-iodoacetyl)amino)ethyl)amino)naphthalene-1-sulfonic acid) or an acceptor probe (5-iodoacetamidofluorescein). In free solution, the distance between these probes was too large to allow significant FRET, but in the rigor complex with F-actin, intermolecular interhead distances between S1 molecules, HMM molecules, or S1 and HMM were determined to be 6.0-6.3 nm. The radial coordinate of the labels relative to F-actin was 5.0-6.4 nm. However, the intramolecular interhead distance in HMMs in which the two heads were labeled with D and A probes was estimated to be larger. The binding affinity of the second head of HMM(D/A) to F-actin may be reduced because of heterogeneous modification of the SH1 groups, such that the probability of single-head binding is increased.

Actins↗
PubMed1997

Two-dimensional arrangement of a functional protein by cysteine-gold interaction: enzyme activity and characterization of a protein monolayer on a gold substrate.

We have characterized the functional protein, myosin subfragment 1 (S1), attached to a gold substrate by the sulfhydryl groups of cysteine in proteins. The amino groups of the regulatory light chain (RLC) isolated from myosin were labeled with a radioisotope (125I), and the labeled RLC was incorporated into S1 from which the RLC had been removed. The radiation from 125I showed that S1 molecules had attached to the gold and, through the interference effect of the monochromatic radiation from 125I, provided information about the position of labeled RLC sites in the S1 monolayer. The interference fringes showed that the RLC was located close to the gold surface and that all of the adsorbed S1 molecules had the same orientation. We confirmed that the motor function of S1 on the gold surface is maintained by observing sliding movement at low ionic strength and by observing the detachment at high ionic strength of fluorescent actin filaments in the presence of ATP. We also found that the adsorbed S1 molecules were not removed from the Au surface by a reducing agent. Thus the Au-S bond is more stable than the S-S bond.

Actins↗
PubMed1997

Dissociation between semantic and autobiographic memory: a case report.

We report a patient who showed a dissociation between impaired semantic memory and preserved autobiographic memory. M.N., a 56-year-old right-handed woman, developed a supra sellar meningioma and underwent multiple operations. Following Lineac radiation, necrosis occurred in the left temporal lobe. Magnetic Resonance Imaging revealed bilateral lesions in the temporal lobes and in the right basal frontal lobe. The patient's intellectual deterioration and anterograde amnesia were mild. Language was preserved, but for a subtle anomia. Autobiographic memory remained intact, while semantic memory for public events, historical figures, cultural items, knowledge of low frequency words and technical terms related to her profession was severely impaired. We hypothesize that bilateral lesions of the anterior half of the middle region of the temporal lobe plays a crucial role in causing deficits in semantic memory.

Amnesia↗
PubMed1997

Pelvic floor electrical stimulation in the treatment of stress incontinence: an investigational study and a placebo controlled double-blind trial.

PURPOSE: We designed an investigational study and a placebo controlled, double-blind study to evaluate the usefulness of electrical pelvic stimulation in stress incontinence. MATERIALS AND METHODS: We studied 44 patients with stress incontinence (six men and 38 women, age 63 +/- 13), including 9 patients in the investigational study and 35 in the double-blind study. We used 50 Hz. square waves of 1 ms. pulse duration for stimulation. A vaginal electrode was used in women and an anal electrode in men. Urethral pressure profile before, during and after 15-minute stimulation was measured in the investigational study. In the double-blind trial an active device and a dummy device were used, and efficacy was judged from patient impressions, records in frequency/volume chart, results of 1-hour pad test and urodynamic parameters after 4-week treatment. RESULTS: In the investigational study maximum urethral closure pressure (mean plus or minus standard deviation) before, during and after stimulation was 44.4 +/- 17.5, 64.5 +/- 28.8 and 46.8 +/- 25.6 cm. water, respectively. This parameter significantly increased (p = 0.0275) during stimulation. In the double-blind trial patient impressions were good in 60% of the active device group and 8% of the dummy device group (p = 0.0051). For the pad test significant improvement was noted in the active device group (p = 0.0100). Cure rate was 45% in the active device group and 7.7% in the dummy device group. There were significantly more cured or improved patients for frequency of leakage (p = 0.0196) and pad test (p = 0.0100). CONCLUSIONS: Electrical stimulation is effective for the treatment of stress incontinence.

Aged↗
PubMed1997

Effect of glucocorticoid receptor antagonist RU 38486 on acute glucocorticoid-induced insulin resistance in rat adipocytes.

We examined the mechanism of acute glucocorticoid-induced insulin resistance in rat adipocytes using the glucocorticoid receptor antagonist RU 38486. Pretreatment with dexamethasone (DEX) and prednisolone for 60 minutes resulted in 50% inhibition of insulin-induced [3H]2-deoxyglucose (DOG) uptake at 10(-8) and 10(-7) mol/L, respectively, in rat adipocytes and 20% and 25% inhibition of insulin-induced [3H]2-DOG uptake, respectively, in soleus muscles. Our previous experiments indicated that DEX and prednisolone alone stimulate protein kinase C (PKC) in rat adipocytes. Accordingly, we examined [3H]DEX binding to PKC from MonoQ column-purified rat brain cytosol. Specific [3H]DEX binding to MonoQ column-purified PKC was observed (kd, 56.8 nmol/L; Bmax, 725 fmol/mg protein). Thus, insulin-induced PKC translocation from the cytosol to the membrane was suppressed by pretreatment with 10(-7) mol/L DEX and 10(-6) mol/L prednisolone for 80 minutes. During treatment with RU 38486 for 60 minutes, there was no change in the glucocorticoid-induced inhibitory effect on insulin-induced [3H]2-DOG uptake and PKC translocation from the cytosol to the membrane. Moreover, pretreatment with RU 38486 for 120 minutes slightly prevented the DEX-mediated inhibition of insulin-induced glucose uptake. These results suggest that acute glucocorticoid-induced insulin resistance may be mainly mediated through the other non-glucocorticoid receptor pathway.

Adipocytes↗
PubMed1997

Acute effects of phorbol ester and insulin on insulin-induced glucose uptake and protein kinase C activation in rat adipocytes.

We examined the acute effect of pretreatment with phorbol ester and insulin on insulin-induced glucose uptake and protein kinase C (PKC) translocation from cytosol to the membrane in rat adipocytes. Adipocytes were preincubated with 1 microM tetradecanoylphorbol 13-acetate (TPA) and 10 nM insulin for 60 min and then stimulated with 10 nM insulin for 10 and 30 min to measure PKC activity in cytosol and membrane fractions using a Mono Q column connected onto an HPLC system and [3H]2-deoxyglucose (DOG) uptake, respectively. Pretreatment with 1 microM TPA and 10 nM insulin for 60 min resulted in the marked decreases of insulin-induced [3H]2-DOG uptake. Translocation of Mono Q column-purified cytosolic PKC enzyme activity and PKC beta immunoreactivity from cytosol to the membrane was suppressed by pretreatment with TPA and insulin for 60 min. These results indicate that acute treatment with TPA and insulin which are PKC activators suppress translocation/activation of PKC, and accordingly inhibit insulin-induced glucose uptake. We suggest that a decrease of cytosolic PKC activity may mainly-contribute to the impaired responsiveness of the glucose transport system after acute TPA and insulin treatment.

Adipocytes↗