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Biomedical subjects

Y Miyake

Publications and source records attributed to Y Miyake.

At least 109 records · Page 6Linked to original sources
PubMed2000

The use of sevoflurane in a 2:1 mixture of nitrous oxide and oxygen for rapid mask induction of anaesthesia in the cat.

An inhalational technique for rapid induction of anaesthesia in unsedated cats using sevoflurane and nitrous oxide is described. Using a pliable, tight-fitting, face mask, sevoflurane (7.5-8%) was delivered from an out-of-circuit precision vaporiser connected to a coaxial non-rebreathing system using a fresh gas flow of 1 l oxygen and 2 l nitrous oxide per min. Cats were restrained with gentle but firm pressure applied by scruffing the dorsal cervical skin until the righting reflex was lost and the patient could be positioned in lateral recumbency. Typically, cats could be positioned on their side in a light plane of anaesthesia within 1 min of applying the mask, at which time the sevoflurane concentration was reduced to 5% or less. A similar protocol, using a lower initial concentration of sevoflurane, is recommended for old or debilitated patients. Maintenance of light sevoflurane (2-4%) anaesthesia by mask permitted minor interventions to be performed readily, including blood collection, intravenous chemotherapy, abdominal palpation, radiography and ultrasonography. More painful procedures, such as bone marrow aspiration, required a deeper plane of anaesthesia. Cats were sufficiently deep to be intubated, if this was required, about 3 min after commencing the induction. Recovery from sevoflurane/nitrous oxide anaesthesia was smooth and rapid, with most cats being able to right within 5 min of discontinuing the agents. This protocol for rapid inhalational induction and recovery is particularly suited to feline practice, where rendering an uncooperative patient unconscious greatly facilitates the completion of many minor diagnostic and therapeutic procedures, especially when these must be performed on successive days or when peripheral vascular access is limited. For longer procedures, isoflurane may be substituted for sevoflurane for maintenance of anaesthesia in order to minimise cost.

Anesthesia Recovery Period↗
PubMed2000

Effects of beraprost and cilostazol and renal function on serum thrombomodulin levels in diabetic patients.

Serum thrombomodulin (TM) levels were determined in diabetic patients, and the effects of diabetic complications and renal function on TM were studied. Serum TM levels increased in diabetics, and patients with diabetic nephropathy tended to manifest higher levels of TM. There was a significant correlation between TM and serum creatinine levels. In addition, there was a significant elevation in serum TM levels in diabetics over time (1 year to 1 year 8 months), and the changes were particularly evident in patients who had a higher TM level from before the observation period. Furthermore, when patients were treated with an antiplatelet agent--beraprost (CAS 88475-69-8) or cilostazol (CAS 73963-72-1)--a significant reduction in TM levels was observed after 3 months. It is suggested that TM could be used as index to assess the development of clinical complications in diabetics and that anti-platelet agents have potential usefulness in delaying the aggravation of diabetic complications.

Cilostazol↗
PubMed2000

Maintenance-type DNA methyltransferase is highly expressed in post-mitotic neurons and localized in the cytoplasmic compartment.

Maintenance-type DNA methyltransferase (Dnmt1) is usually down-regulated in non-proliferating cells. In the present study, we detected significant expression of Dnmt1 protein in adult mouse brain where the majority of the cells are in a post-mitotic state. A significant amount of Dnmt1 protein was fractionated into the post-nuclear fraction for both cerebrum and cerebellum. The Dnmt1 in this fraction was enzymatically active. An immunofluorescence study revealed that Dnmt1 protein was mainly expressed in neurons and seemed to be localized in the cytoplasmic compartment. Primary culturing of neurons confirmed the expression and localization of Dnmt1 in the cytoplasmic compartment. The findings that the Dnmt1 transcript in the brain utilized the somatic-type exon and that the apparent size of the Dnmt1 protein in the cytoplasm was identical to that in proliferating culture cells indicate that the cytoplasmic Dnmt1 in neurons was of the somatic-type.

Animals↗
PubMed2000

Structural change of bovine retinal cGMP phosphodiesterase by release of its gamma subunit: direct imaging by improved low angle rotary shadowing.

Cyclic GMP phosphodiesterase (PDE), a key enzyme for phototransduction, contains two catalytic subunits, Palpha and Pbeta, and two identical regulatory subunits, Pgammas. Neither the structure of the subunits of PDE nor their changes in structure during PDE regulation have been known. Here, improved low angle rotary shadowing was applied to depict the three-dimensional structure of bovine PDE (Palphabetagammagamma) and its changes by Pgamma release. Palphabetagammagamma and Palphabetagamma were isolated from photoreceptor membranes after treatment with a hydrolysis-resistant GTP analogue, and Palphabeta was prepared from Palphabetagammagamma tryptic digestion. Images of Palphabetagammagamma consisted of two crooked strands. These two strands faced each other to make a ring shape, but this ring structure was bent at the centre line between the two strands. In Palphabetagamma, one of these strands changed its shape toward reducing the central space of the ring structure. This ring appeared to be more bent at the centre line. In Palphabeta, both strands changed their shape such that the ring structure appeared to be a twisted quasi ring shape. These observations suggest that in Palphabetagammagamma each Pgamma is complexed with a catalytic subunit, and that the shapes of Palpha and Pbeta are drastically changed by the Pgamma release. These shape changes are no doubt crucial for various PDE regulations, such as activation of cGMP hydrolysis by Palphabeta, interaction of Palphabeta with GARP2 and a GARP2-like protein and cGMP binding to non-catalytic sites on Palphabeta.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2000

Triple marker screening for trisomy 21, trisomy 18 and open neural tube defects in singleton pregnancies of native Japanese pregnant women.

OBJECTIVE: To report the results of prenatal triple marker screening on a population of Japanese pregnant women. METHODS: From April 1994 through March 1999, a total of 32,925 native Japanese women with singleton pregnancies requested a triple marker-screening test. Multiples of the median values for 3 markers and individual risks for each patient were calculated following adjustment for the Japanese weight correction factor. The risk cut-off values used for Down syndrome (T21), open spina bifida (OSB) and trisomy 18 (T18) were 1: 295, 1: 290, and 1: 100, respectively. Follow-up information was collected postpartum and statistically analyzed. RESULTS: Detection rates (DR) of T21 for women less than 35 years, over 35 years and overall were 58, 94, and 83%, respectively. DR of T18 for women less than 35 years, over 35 years and overall were 75, 79, and 79%, respectively. DR of open neural tube defects (ONTD) was 100%. CONCLUSIONS: The first cumulative data of an intervention program and prospective follow-up studies in Japan have proven to be similar to other published reports. Individual risk values were calculated for each pregnancy for T21, T18 and ONTD. This screening program is more effective than age-dependent screening for detecting T21, T18 and ONTD pregnancies.

Adult↗
PubMed2000

Effect of sarpogrelate hydrochloride on platelet-derived microparticles and various soluble adhesion molecules in diabetes mellitus.

We measured platelet-derived microparticles, activated platelets, and various adhesion molecules in 48 patients with diabetes mellitus. We also performed a comparative study of these parameters before and after administration of sarpogrelate hydrochloride. The numbers of platelet-derived microparticles and activated platelets were increased significantly in diabetic patients, and CD63-positive platelets were increased in patients with diabetic complications and poorly controlled blood glucose. Soluble adhesion molecules and thrombomodulin were also increased significantly. After administration of sarpogrelate hydrochloride, not only CD62p- and CD63-positive platelets, but also platelet-derived microparticles were decreased significantly. Soluble adhesion molecules and thrombomodulin were also significantly decreased after the treatment. These data suggest that (a) in patients with diabetes, antiplatelet therapy with sarpogrelate hydrochloride is a useful antithrombin therapy because it suppresses the production of intrinsic coagulants by activated platelets; and (b) sarpogrelate hydrochloride decreases endothelial cell damage via adhesion molecules.

Antigens, CD↗
PubMed2000

[1-11C]Octanoate as a PET tracer for studying ischemic stroke: evaluation in a canine model of thromboembolic stroke with positron emission tomography.

Octanoate is taken up by the brain and converted in astrocytes to glutamine through the TCA cycle after beta-oxidation. Consequently, [1-11C]octanoate might serve as a useful positron emission tomography (PET) probe for studying cerebral oxidative metabolism and/or astroglial functions. The present study attempted to evaluate the utility of using [1-11C]octanoate as a PET tracer for imaging and evaluating the pathophysiology of ischemic stroke. We used a canine model of thromboembolic stroke. Five male beagle dogs were implanted with an indwelling catheter in the left internal carotid artery. A single autologous blood clot was injected into the left internal carotid artery through the catheter. The brain distribution of [1-11C]octanoate and cerebral blood flow (CBF) were determined 24 h after insult using a high resolution PET scanner. Post mortem brain regions unstained with 2,3,5-triphenyltetrazolium chloride (TTC) were defined as infarcts. In the region of an infarct, accumulation of [1-11C]octanoate decreased concurrently with CBF reduction. In contrast, normal accumulation of [1-11C]octanoate was observed in ischemic but vital regions, suggesting that an increased accumulation of [1-11C]octanoate relative to CBF takes place in these regions. In conclusion, [1-11C]octanoate accumulated in ischemic but vital regions, indicating that [1-11C]octanoate is a potentially useful PET tracer for imaging and evaluating the pathophysiology of ischemic stroke.

Animals↗
PubMed2000

Risk factors for non-fatal acute myocardial infarction in middle-aged and older Japanese. Fukuoka Heart Study Group.

It remains uncertain whether established risk factors for coronary heart disease in middle-aged persons can be generalized to elderly persons. Based on a case-control study, risk factors for nonfatal acute myocardial infarction (AMI) were assessed separately in middle-aged (40-64 years) and older (65-79 years) Japanese. Eligible cases were patients who were admitted to 22 collaborating hospitals for the first AMI between September 1996 and January 1998. Community controls were recruited by using the resident registers of the municipalities with individual matching by gender, year of birth (within 2 years), and proximity in residence. The present study used 384 sets of 384 cases and 656 controls. Smoking, hypertension, and angina pectoris were associated with an increased risk of AMI, and alcohol use and leisure-time exercise were related to a decreased risk of AMI in the elderly as well as in middle-aged persons. There was no apparent relation between body mass index and AMI in either middle-aged or older adults. Diabetes mellitus was significantly associated with an increased risk of AMI in older persons, but not in middle-aged persons. Hypercholesterolemia was related to an increased risk of AMI in middle-aged individuals alone. The findings suggest that risk factors for AMI in the elderly are generally similar to those of middle-aged persons, but provide no evidence that hypercholesterolemia in the elderly is an important risk factor.

Adult↗
PubMed2000

Apoptosis induced by the flavonoid from lemon fruit (Citrus limon BURM. f.) and its metabolites in HL-60 cells.

The flavonoid from lemon fruit (Citrus limon BURM. f.) and its metabolites, particularly eriodictyol, 3,4-dihydroxyhydrocinnamic acid, and phloroglucinol had the function of DNA fragmentation in HL-60 cells when analyzed by flow cytometry. An apoptotic DNA ladder and chromatin condensation were observed in HL-60 cells when treated with these compounds. The caspase inhibitor prevented DNA fragmentation. These compounds are anticipated to be useful for medical purposes.

Apoptosis↗
PubMed2000

Depressor effect by exercise training is associated with amelioration of hyperinsulinemia and sympathetic overactivity.

OBJECTIVE: In hypertensive subjects, exercise training is a therapeutic modality that not only lowers blood pressure but also corrects metabolic abnormality, such as hyperinsulinemia. Insulin causes sympatho-excitation via the modification of baroreflex, norepinephrine release, or central sympathetic outflow. However, the link between neural and metabolic changes by exercise training in hypertensive patients remains unknown. The aim of this study was to examine whether or not the blood pressure lowering effect of exercise training is associated with the improvement of insulin sensitivity in conjunction with the inhibition of sympathetic tone in hypertensive patients. METHODS: We evaluated plasma insulin levels, arterial baroreflex function and humoral parameters before and after exercise training. Twenty-nine patients with essential hypertension under hospitalization participated in the study. Before and after three weeks of exercise training (75% max VO2, 6 min, q.i.d.), 24-hour blood pressure recordings, arterial baroreflex function testing and 75 g glucose tolerance tests were conducted. Area under the curve of insulin (sigma insulin) to glucose load was calculated as an index of hyperinsulinemia. RESULTS: Three weeks of exercise training decreased the 24-hour mean arterial pressure, heart rate and sigma insulin, and improved barorefiex function. There was a significant correlation between the reduction of arterial pressure and the change in sigma insulin. Furthermore, the reduction of sigma insulin was correlated with the improvement of baroreflex function and with the decrease in heart rate. CONCLUSIONS: Exercise training lowered the arterial pressure, with parallel changes in heart rate, baroreflex function and insulin resistance. The correction of sympathetic overactivity was closely associated with the amelioration of hyperinsulinemia. Our results suggest that the improvement of neuro-metabolic factors may be involved in the depressor effect caused by exercise training.

Area Under Curve↗
PubMed2000

Body sway induced by depth linear vection in reference to central and peripheral visual field.

PURPOSE: A significant correlation between the magnitude of linear vection and the degree of body sway induced by a visual stimulus perceived as moving in depth was previously described (Jpn J Physiol 49: 417-424, 1999). The purpose of this study was to examine the role of the central and peripheral visual fields in inducing vection and body sway. METHODS: Ten healthy volunteer students who had no vestibular or neurological disorders served as subjects. A depth optokinetic stimulus (DOKS) was projected onto a head-mounted display (HMD) and was perceived to move in depth. Different amounts of the central or peripheral visual field were masked independently. The magnitude of the linear vection induced by the DOKS was evaluated by verbal assessment and compared with the magnitude of induced body sway. Body sway was monitored by a video-motion-analyzer that recorded the movement of the head, shoulder, hip, knee and ankle. RESULTS: The magnitude of vection was correlated with the frequency of DOKS and also with the amplitude of body sway (r = 0.74). When the central visual field was restricted by 10 to 30%, there was almost no change in the induced body sway and vection. However, when central occlusion was greater than 40%, depth perception and induced body movement were greatly reduced. With increasing amounts of peripheral field occlusion from 50 to 90%, there was a greater reduction of both vection and body sway. CONCLUSION: Vection is strongly correlated with body movement, and vection and body sway were more dependent on stimulation of the peripheral visual field.

Adult↗
PubMed2000

Eye examinations at the National Institute for Longevity Sciences--Longitudinal Study of Aging: NILS-LSA.

The National Institute for Longevity Sciences--Longitudinal Study of Aging (the NILS-LSA) started in 1997, and involves many kinds of examination. The objective of this paper is to outline the eye examinations in the NILS-LSA. The eye examinations consist of checks on refractometry, visual acuity, intraocular pressure, contrast sensitivity, kinetic visual acuity, visual fields, fundus photography, and lens estimation. The subjects were 1,077 men and women aged 40-79 years who participated in the first year examination of the NILS-LSA. All subjective measurements (distant visual acuity, kinetic visual acuity, contrast sensitivity, and mean sensitivity of visual field) declined significantly from the 50s. Age-related structural changes in the lens or hypertensive and arteriosclerotic changes in retinal vessels began at least in the 40s. It is suspected that aging affects the subjective visual functions from the 50s. However, changes in the structure of eye may begin before the 40s. The data from the eye examinations of the NILS-LSA are useful to assess the aging effects on vision and to investigate the relationship between visual function and physical or psychosocial health problems among the elderly.

Adult↗
PubMed2000

[A case of an advanced aged Eisenmenger's syndrome].

We report a 70-year-old women with Eisenmenger's syndrome. Eisenmenger's syndrome with ventricular septal defect was diagnosed at another hospital when she was 32 years old. Then, she was referred to our hospital at age 60 old and she now is according to the out patient in over clinic. She have mild cardiac function, NYHA classification, was II-M, polycythemia cell blood count 535 x 10(4) and 17.2 g/dl in hemoglobin. Echocardiography suggested serious Eisenmenger's syndrome. The left ventricle was compressed, the blood pressure of the right ventricle exceeded 105 mmHg, and the onset of the right to left shunt flow was thought to be 250 msec bored on the electrocardiogram Q wave. The reason why the progression of complicated obstructive pulmonary artery disease was slow may have been become of the mildness of her polycythemia, and this is presumed to be the reason for her long survival to age 70.

Aged↗
PubMed2000

Quantification of micrometastases in lymph nodes of colorectal cancer using real-time fluorescence polymerase chain reaction.

The expression of carcinoembryonic antigen (CEA) mRNA was assessed in 102 lymph nodes (LNs) obtained from seven colorectal cancer patients by both the conventional non-quantitative RT-PCR and quantitative RT-PCR. The number of CEA-expressing cells was calculated compared with CEA-expressing MKN-45 cell line as a standard control. Using the quantitative RT-PCR, the relative number of CEA-expressing cells ranged between 1.3x103 and 5.7x106 in 16 histologically positive LNs and between 2.3x101 and 8.1x105 in 10 histologically negative and RT-PCR positive LNs. In both histologically and RT-PCR negative LNs, the relative cell number was <4.0x102. Our results demonstrated that quantifying the amount of metastasis might enhance the reliability of RT-PCR detection assay as a diagnostic tool for the detection of cancer micrometastases.

Adult↗
PubMed2000

Multifocal electroretinogram in occult macular dystrophy.

PURPOSE: Occult macular dystrophy (OMD) is an unusual macular dystrophy presenting with an essentially normal fundus and fluorescein angiography but with progressive central visual loss. The authors studied the function of local retinal areas in the posterior pole of patients with OMD using multifocal electroretinograms (ERGs). METHODS: Multifocal ERGs were recorded using the Visual Evoked Response Imaging System with 61 hexagonal elements within a visual field of 30 degrees radius from 8 OMD patients and 20 age-matched, normal subjects. The amplitudes and implicit times of the patients and normal control subjects were compared at the various retinal eccentricities. RESULTs. The amplitudes of the multifocal ERGs in the OMD patients were markedly reduced in the central 7 degrees of the fovea. The difference of the ERG amplitudes between OMD and normal subjects became smaller toward the peripheral retina. Most OMD patients had slight but significantly delayed implicit times across the whole testing field, and the differences between the OMD and the normal subjects did not change with retinal eccentricity. CONCLUSIONS: Our results for multifocal ERG amplitudes support the idea that OMD patients have localized retinal dysfunction distal to the ganglion cells in the central retina. The delayed implicit times across the whole test field suggest that the retinal dysfunction has a broader boundary than expected by ERG amplitudes and psychophysical perimetric results.

Adult↗
PubMed2000

[Neovascular maculopathy associated with rubella retinopathy].

BACKGROUND: We report three eyes of two patients with rubella retinopathy which were associated with choroidal neovascularization in the macula. CASES: A 7-year-old girl (case 1) and a 12-year-old girl (case 2) whose mothers had suffered rubella during their pregnancy revealed typical rubella retinopathy in both eyes and neovascular maculopathy in one eye at their initial visit to our clinic. Neovascular maculopathy developed in another eye of case 1 after a follow-up of 10 months. RESULTS: The clinical characteristics indicated that 1. sudden visual loss occurs in children, 2. there is no external trigger such as eye injury, and 3. the visual prognosis appears relatively good. CONCLUSION: Although neovascular maculopathy is rare in pediatric disease, the rubella retinopathy may have the potential to cause neovascular maculopathy.

Child↗