Biomedical subjects

Y Doi

Publications and source records attributed to Y Doi.

At least 289 records · Page 16Linked to original sources

PubMed1994

Crystallization and preliminary crystallographic data of vitelline membrane outer layer protein I, VMO-I.

The vitelline membrane outer layer protein I (VMO-I), which is isolated from the vitelline membrane outer layer of hen's eggs, has been crystallized from an acetate buffer solution by the hanging-drop method. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell dimensions a = 62.42 A, b = 110.52 A, c = 44.15 A. There are two molecules (M(r) = 18,000) per asymmetric unit. The crystals diffract to at least 2.2 A Bragg spacings.

Animals↗

PubMed1994

Role of mesenchymal cells in the neovascularization of the rabbit phallus.

The neovascularization of the rabbit phallus at ages between prenatal days 15 and 21 was investigated by light- and electron microscopy, computer-aided light microscopic reconstruction, and immunocytochemistry. The phalli are embedded by an abundance of mesenchymal cells, which are in contact with the neighboring ones or with the endothelial lining of growing capillaries. They often form solid cell cords that eventually make contact with the growing capillaries. The computer-aided reconstruction of the serial light micrographs reveals that these cell cords are involved in connecting the adjacent capillaries. The incorporation of such mesenchymal cell projections into the endothelial lining, occasionally conjugated with simple attachment devices, is frequently observed by transmission and scanning electron microscopy. The contact areas between the mesenchymal and endothelial cells show immunoreactions of fibronectin. These results indicate the successive transformation of mesenchymal cells to endothelial cells of the growing capillaries. As endothelial cells of the growing capillaries show mitotic proliferation, such vasoformative mesenchymal cells seem to be involved in the acceleration of the neocapillarization of the rabbit phallus. Fibronectin actively produced in the mesenchymal cells may participate in their migration and the mechanical linkage with the endothelial cells.

Animals↗

PubMed1994

Experimental study and clinical use of poly(vinyl acetate) emulsion as liquid embolisation material.

A new material, an emulsion of poly(vinyl acetate) was experimentally developed and clinically used to overcome several disadvantages in currently used liquid embolisation materials. The emulsion microparticles, 0.3-0.7 microns in size, possessed cationic charge on the surface and hence aggregated immediately on contact with fluids containing anions. This inert polymer has the advantage that it does not induce a deleterious reaction in living tissue. Moreover, its medium is water and it is not adhesive, like the cyanoacrylates. Several concentrations of emulsion were injected into the renal arteries of dogs. For the investigation of tissue reactions and the possibility of recanalisation, the emulsion was injected into rats both subcutaneously and into the renal arteries. The renal artery injections in dogs showed adequate radiopacity and consistent complete occlusion. The lower the concentration of the emulsion, the smaller the arteries which could be occluded. Even at very low concentrations, however, venous occlusion did not occur. Histological study of the embolised rat kidney revealed no detectable damage in the vessel wall and no recanalisation for up to 6 months. The subcutaneously injected PVAc emulsion elicited mononuclear cell infiltration and gradual centripetal fibrosis, without any deleterious effect on the surrounding tissue. A cerebral arteriovenous malformation (AVM) was embolised using the material. Histology of the resected nidus showed findings similar to those in the animal experiments.

Adult↗

PubMed1994

Microbial synthesis and properties of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) in Comamonas acidovorans.

Comamonas acidovorans DS-17 was isolated from activated sludge and found to produce copolymers of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) at 30 degrees C under growth-limited conditions. When 1,4-butanediol or 4-hydroxybutyric acid was used as the sole carbon source, a P(4HB) homopolymer was produced. Random copolymers of 3HB and 4HB units were produced on the addition of glucose or 3-hydroxybutyric acid to the culture solution of 4-hydroxybutyric acid. The physical properties of P(3HB-co-4HB) copolyesters with high 4HB fractions (64-100 mol%) were investigated. The copolyester films with high 4HB fractions exhibited the characteristics of a thermoplastic elastomer, and the tensile strength increased from 17 to 104 MPa as the 4HB fraction was increased from 64 to 100 mol%. The biodegradabilities of P(3HB-co-4HB) films were studied in aqueous solutions of extracellular polyhydroxybutyrate (PHB) depolymerase from Alcaligenes faecalis or of lipase from Rhizopus delemer. The erosion rate of P(3HB-co-4HB) films by PHB depolymerase decreased as the 4HB fraction in copolyester was increased from 64 to 100 mol%. In contrast, the erosion rate of films by lipase increased with the 4HB fraction.

Biodegradation, Environmental↗

PubMed1994

Biosynthesis from gluconate of a random copolyester consisting of 3-hydroxybutyrate and medium-chain-length 3-hydroxyalkanoates by Pseudomonas sp. 61-3.

Pseudomonas sp. 61-3 isolated from soil was found to produce a polyester consisting of 3-hydroxyalkanoic acids of even carbon numbers C4, C6, C8, C10 and C12 when sodium gluconate was fed as the sole carbon source. The polyester produced was fractionated with boiling acetone. The acetone-insoluble fraction (28 wt%) of the polyester was a poly(3-hydroxybutyrate) homopolymer, while the acetone-soluble fraction (72 wt%) was composed of seven different 3-hydroxyalkanoate (3HA) units ranging from C4 to C12: 40 mol% 3-hydroxybutyrate (3HB), 5 mol% 3-hydroxyhexanoate (3HH), 20 mol% 3-hydroxyoctanoate (3HO), 24 mol% 3-hydroxydecanoate (3HD), 1 mol% 3-hydroxy-5-cis-decenoate (3H5D), 4 mol% 3-hydroxydodecanoate (3HDD) and 6 mol% 3-hydroxy-5-cis- dodecenoate (3H5DD). The copolymer was characterized by nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography and differential scanning calorimetry. The acetone-soluble fraction of this amorphous copolymer was shown to have a random sequence distribution of the seven 3HA units of C4 to C12 by analysis of the 150 MHz 13C-NMR spectrum. This is the first example of microbial synthesis of a random copolyester consisting of 3HB and medium-chain-length 3HA units.

3-Hydroxybutyric Acid↗

PubMed1994

Abnormal coronary flow dynamics at rest and during tachycardia associated with impaired left ventricular relaxation in humans: implication for tachycardia-induced myocardial ischemia.

OBJECTIVES: This study attempted to clarify the effect of ventricular relaxation abnormalities on coronary flow dynamics at rest and during tachycardia in humans. BACKGROUND: Ventricular relaxation abnormality has been demonstrated in animals to have an adverse impact on early diastolic coronary flow dynamics. However, this relation has not been established in humans. Even if the adverse effect were latent at rest, it might become evident during tachycardia because tachycardia reduces coronary flow reserve and facilitates the production of myocardial ischemia. METHODS: Doppler phasic left coronary flow velocity pattern was obtained at rest and during tachycardia in 23 patients without coronary stenosis. The time constant of left ventricular isovolumic pressure (tau) was used to assess ventricular relaxation. RESULTS: The time to peak flow velocity of the diastolic coronary flow wave was longer, and the fraction of the first third of diastolic coronary flow was smaller, in patients with a longer tau (r = 0.58, p < 0.01; r = -0.44, p < 0.05), indicating a close relation between early diastolic coronary flow dynamics and ventricular relaxation. Although rapid atrial pacing yielded an increase in the coronary flow velocity integral per minute in all patients, diastolic coronary flow velocity integral per minute increased in 9 patients with a normal (< or = 40 ms) tau at rest but decreased in 14 patients with a longer (> 40 ms) tau at rest. CONCLUSIONS: Impaired left ventricular relaxation was associated with decreased coronary flow in early diastole at rest and decreased coronary flow throughout diastole during tachycardia in patients without coronary stenosis. These findings may provide more insight into the mechanism of tachycardia-induced subendocardial ischemia in patients with impaired ventricular relaxation but without concomitant coronary stenosis.

Adult↗

PubMed1994

Effect of bis (tributyl tin) oxide on permeability of the blood-brain barrier: a transient increase.

OBJECTIVES: To study the effect of bis (tributyl tin) oxide (TBTO) on permeability of the blood-brain barrier. METHODS: Electron microscopy and an x ray microanalyser with lanthanum chloride as a tracer were used, and blood tin concentrations were determined with an atomic absorption spectrophotometer. Adult male wistar rats received 0.05 ml/kg body weight of TBTO orally. RESULTS: A transient increase in paracellular permeability at the blood-brain barrier was found 2 h after the dose of TBTO. Electron dense lanthanum deposits penetrated tight junctions of the endothelia and permeated the subendothelial space. The x ray microprobe data showed an accumulation of TBTO at the tight junctions at 2 h. Leakage of tracer did not occur at 4 h, but oedematous changes in the surrounding glial cells were prominent between 4 and 8 h and had almost returned to normal by 24 h. By atomic absorption analysis, it was seen that blood tin concentrations rapidly increased at 1 h and rose to a maximum peak at 8 h, then gradually decreased to reach zero at 24 h. CONCLUSIONS: Accumulated TBTO at tight junctions could have caused the temporary replacement of calcium ion by tin, which induces a transient increase in paracellular permeability throughout the blood-brain barrier.

Animals↗

PubMed1994

The differentiation of entero-endocrine cells of pre- and postnatal rats: light and electron microscopy and immunocytochemistry.

The differentiation of cholecystokinin/gastrin (CCK/GA)-, glucagon (GLU)- and somatostatin (SOM)-positive cells in the pre- and postnatal rat duodenum was investigated with a special emphasis on the relationship to that of the fibromuscular intestinal wall by light and electron microscopy and immunocytochemistry. Between prenatal days 16 and 21, contacts of mesenchymal cells with the epithelium are frequent, and the differentiation of the entero-endocrine cells which occasionally display a secretory function becomes advanced in close proximity to an extensive capillary network in the underlying connective tissue. CCK/GA-positive cells can be detected by immunocytochemistry in the intestinal epithelium at prenatal day 18. Other types of entero-endocrine cells are not detected until prenatal day 19. Quantitative analysis demonstrates that the volume density of CCK/GA-positive cells per 100 microns2 cytoplasmic area increases sharply at postnatal day 5 relative to earlier stages. This may be mainly due to suckling of the neonatal rat.

Animals↗

PubMed1994

[Normal ranges of blood urea nitrogen and serum creatinine levels in the community-dwelling elderly subjects aged 70 years or over--correlation between age and renal function].

To estimate normal ranges of blood urea nitrogen (BUN) and serum creatinine (Cr) levels in the aged, we measured BUN and Cr levels in 332 cases of apparent-healthy elderly subjects (male, 152; female, 180) aged 70 years or more. We measured the variables also in 315 cases of sex-matched young control subjects (male, 139; female, 176). This study was a part of the Kahoku Longitudinal Aging Study (KLAS) that aims to reveal the comprehensive functions in the aged. We calculated the mean and the standard deviation (SD) in each group, and excluded subjects with values beyond twice the SD-line. We defined the normal range as range within the single SD-line of the remainder. The estimated normal range of BUN was 14-23 mg/dl both in male and female elderly subjects, and that of Cr was 0.9-1.3 mg/dl in male and was 0.7-1.1 mg/dl in female. The mean BUN level in the elderly subjects was significantly higher than that in the control young subjects. The mean Cr level in the elderly subjects was slightly higher than that in the control subjects. Significant positive correlation was found between BUN levels and age in male elderly subjects. Although Cr levels did not correlate with age in elderly subjects, Cr levels divided by body surface area significantly correlated with age. We concluded that the normal range of BUN and Cr levels differed between young and elderly subjects, and that the decline in renal function correlated with age after the seventh decade.

Adult↗

PubMed1994

[Longitudinal change in independence in the elderly--Kahoku Longitudinal Aging Study (KLAS)].

A community based study named Kahoku Longitudinal Aging Study (KLAS) was conducted since 1990 for the purpose of evaluating the comprehensive geriatric functional assessment (CGA) and preventing a decline in CGA in the community-dwelling elderly population. It was carried out in a Japanese rural town, in which 32% of the population was over 65 years of age. This study included a questionnaire about activity of daily living (ADL), information-related physical function, mental (cognitive and affective) and social functional domains. In addition to subjective informative instruments, various types of objective assessment such as quantitative neuro-behavioral function tests and medical examinations were performed. Subjects were all the eligible elderly aged over 65 years in the community. Although the ratio of subjects who were independent in ADL decreased with advancing age in both 1991 and 1993, the ratio of the independent elderly in ADL became significant higher (74%) in 1993 than in 1991 (71%). Scores on 2 kinds of neurobehavioral function tests in the 159 subjects aged over 75 years who attended the examination every year showed a significant and slight decrease during two years. However, some test indices significantly improved during the 2 years. These results suggested that age-related dependency in ADL and some kind of neurobehavioral functions might be prevented, in part, by health promoting education and improvement of life style.

Activities of Daily Living↗

PubMed1994

[Comparative study of activity of daily living in the elderly between in Kahoku and in Yaku].

A comparative community-based study of physical activity in the elderly was carried out between two Japanese rural towns, Kahoku and Yaku. This study included a questionnaire about activity of daily living (ADL) and information-related functions in relation to lifestyle. Subjects were all the eligible elderly aged over 65 years of each community (1618 and 704 subjects in Kahoku and Yaku respectively). The ratio of the eligible elderly aged over 65 years were 32% in Kahoku and 2% in Yaku. The response rates were 91% in Kahoku and 51% in Yaku. Common findings in both towns were as below; 1) scores in ADL decreased with advancing age, 2) information-related functions were similar in each town, and between genders, 3) marital condition among males was similar in both towns, 4) ADL scores were higher in the financially rich group than in the poor one, 5) ADL scores were higher in female subjects whose husbands were alive than in widows, 6) ADL scores were higher in subjects who walked every day than those who did not, 7) ADL scores were lower in subjects who took medicine every day than those who did not, however, this finding did not apply to antihypertensive drugs, 8) ADL scores were higher in subjects who drank in beverages than in those who never imbibed. The different results between Kahoku and Yaku were supposed to be due to differences in lifestyle.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗

PubMed1994

[Comparative study of blood pressure variability in the elderly in Kahoku and in Yaku].

A comparative community-based study of blood pressure (BP) variability in the elderly was carried out in the Japanese rural towns of Kahoku and Yaku. The prevalence of hypertension, orthostatic hypotension and use of antihypertensive drugs, effects of postute on BP and the "white coat" effect in BP were examined in each town. There was no difference in the prevalence of hypertension between in the two towns. Orthostatic increase in BP and pulse rate was more common in elderly females than in elderly males in both towns, indicating that standing itself was a load for subjects and activated sympathetic nervous tone in the female elderly. The prevalence of orthostatic hypotension was 8.5% and 12% in Kahoku and Yaku respectively, and the "white coat" effect on BP was demonstrated in the elderly in each town. In conclusion, we should take orthostatic change and the "white coat" effect into consideration in the evaluation of BP among the elderly.

Aged↗

PubMed1994

[Comparative study of serum lipids and other blood chemistry factors in the elderly in Kahoku and Yaku].

A comparative community-based study of serum lipids and other blood chemistry data in the elderly was carried out in two Japanese rural towns, Kahoku and Yaku. We studied the following blood chemistry factors; total proteins (TP), albumin (Alb), blood glucose (glucose), urea nitrogen (BUN), uric acid (UA), total cholesterol (T-Cho), high density lipoprotein (HDL-C) and lipoprotein (a) (Lp(a)). Subjects were the 312 eligible elderly aged over 75 years in Kahoku, and 172 similar elderly in Yaku. There were no significant differences in TP, Alb, glucose, BUN and UA of the elderly in the two areas. Mean HDL-C level was significantly lower and mean Lp(a) concentration was significantly higher in the elderly in Kahoku than in Yaku, Mean value of T-Cho did not differ significantly between the elderly in the two areas, however, the ratio of subjects whose T-Cho concentrations were over 220 mg/dl was significantly higher in Kahoku than in Yaku. These data suggested that the risk of atherosclerosis from the standpoint of view of serum lipids was higher in the elderly in Kahoku than in those in Yaku. Epidemiological data of Kochi and Kagoshima prefecture indicated that the mortality ratio from ischemic heart disease was higher in Kahoku than in Yaku, although that from cerebral infarction was lower in Kahoku than in Yaku. Comparative study of laboratory data in various districts is useful to investigate the relationship between lifestyle and diseases.

Aged↗

PubMed1994

[Comparative study of neurobehavioral function in the elderly between in Kahoku and Yaku].

A comparative study of neurobehavioral functions in the elderly was carried out between two Japanese rural towns, Kahoku and in Yaku. To evaluate of neurobehavioral functions, we used 1) Mini Mental State Examination (MMS), 2) Hasegawa Dementia Scale Revised (HDSR), 3) Kohs block design test, 4) Visuospatial cognitive performance score (VCPS), 5) Button Score (Button-S), 6) Up & Go test, and 7) Functional reach (FR). A questionnaire about ADL, information-related function and lifestyle was also done. Subjects consisted of all the eligible 332 elderly aged over 75 in Kahoku and 194 elderly aged over 75 in Yaku. In Kahoku, each function test had a significant correlation with age. However, in Yaku, the Up & Go, FR, MMS and HDSR results showed no significant correlation with age. Scores in cognitive function tests such as MMS, VCPS, and the Kohs test were better in kahoku than in Yaku, although scores in behavioral function tests such as FR were better in Yaku than in Kahoku. MMS, HDSR and Kohs tests significantly correlated with information-related function while Button-S, Up Go and FR tests had significant correlation one with ADL in both areas. Scores on function tests were better in the living-alone group and the group who had a daily work than in other groups in Kahoku. However, differences in scores in function tests between these two types of groups failed to reach a level of significance in Yaku. These data suggested that the difference in life-style influenced neurobehavioral functions in the elderly.

Activities of Daily Living↗

PubMed1994

[Comparative study of quality of life in the elderly between in Kahoku and in Yaku].

A comparative community-based study of quality of life (QOL) in the elderly was carried out between two Japanese rural towns, Kahoku and Yaku.QOL, which included the subjective sense of health, appetite, sleep at night, mood, memory, family relationships, friendship, economic condition, life satisfaction and happiness was assessed using a visual analogue scale (VAS) as well a Geriatric depression Scale (GDS), a variety of neurobehavioral function tests, and a questionnaire about activity of daily living (ADL). Subjects were all the eligible elderly aged over 75 years in both communities. Inter-rater reproducibility in VSA was more reliable than that in GDS. Life satisfaction and a subjective sense of happiness highly correlated with mood, family relationships, friendship and economic condition. GDS and VAS significantly correlated with family relationships, active participation in a group and economic condition, however, they did not correlated with age. The subjective sense of happiness correlated with ADL and steadiness of walk as assessed by neurobehavioral function tests. Living style correlated with VAS in the male elderly, but not female. Each score in VAS for family relationships, friendship, economic condition, life satisfaction and subjective sense of happiness was significantly higher in the elderly in Yaku than in Kohoku. The diseases which elderly people wanted to avoid were dimentia cancer, stroke, and cardiovascular disease in that order. In conclusion, QOL in the elderly population was influenced by disease, neurobehavioral functions, especially walking function, gender difference, lifestyle as well as cultural environment.

Activities of Daily Living↗

PubMed1994

[Assessment of the pleural cavity with ultrasound and pleurography].

High resolution ultrasonography and ultrasonography guided needle aspiration (UGNA) are useful for the evaluation of pleural lesions. We applied the technique of UGNA for pleurography and were able to see the configuration of the pleural surface and space under physiological conditions. Here we show how these newly developed methods of pleurography and ultrasonography can be used to evaluate changes in pleural configuration and pleural involvement of bronchogenic carcinoma. Newly developed pleurography: A catheter was inserted into the narrow pleural space without making a pneumothorax. After infusion of contrast medium (0.5-1 ml/kg), pleural indentation, adhesions, bullous changes, and partial fusion of lobes were clearly visible. This pleurography is especially useful for the diagnosis of tumor invasion into the pleura and chest wall when the tumor is adjacent to the pleura. Detection of latent malignant pleurisy: Small effusions were detected by ultrasonography in 10% of patients with bronchogenic carcinoma who had no pleural effusion on chest roentgenogram. After UGNA, malignant cells were found in 35% in these tiny effusions (4% of the total). To more accurately assess latent malignant pleurisy, we now perform lavage of the pleural space with 50 ml of saline during pleurography before deciding on surgical treatment.

Adult↗

PubMed1994

Serum levels of soluble CD4 and CD8 in patients with chronic viral hepatitis.

The blood levels of soluble CD8 (sCD8) and soluble CD4 (sCD4) were measured in patients with various liver diseases, and their significance was studied. The levels of sCD8 were significantly higher in patients with chronic active hepatitis (CAH), autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), acute hepatitis (AH), fulminant hepatitis (FH) and liver cirrhosis (LC) as compared with the normal controls (NC), and correlated positively with those of GPT (r = 0.67, p < 0.001). In addition, a comparison of the exacerbation of CAH with remission showed that the sCD8 levels were significantly higher in the former. On the other hand, there was no significant rise in the level of sCD4 in patients with any liver disease, except FH, no definite relationship between sCD4 and sGPT, and no consistant tendency in sCD4 levels between exacerbation and remission. The reason for an insignificant elevation of the sCD4 level is the fact that in hepatitis the CD8-positive cells, which are cytotoxic T cells, are directly involved in hepatocyte damage; therefore the CD8-positive cells are predominantly activated, while the activity of the CD4-positive cells is considered to be lower. Instead of determining the number of CD4-positive cells and CD8-positive cells in the mononuclear cells of peripheral blood, serum sCD4 and sCD8 levels can be measured simply and inexpensively. Thus, these levels may be useful immune markers.

CD4 Antigens↗

PubMed1994

[Surgical indications and prognosis of valvular heart disease and infective endocarditis in the elderly].

To elucidate the surgical results and long-term prognosis in valvular heart disease, including infective endocarditis, in the elderly, 110 patients with valvular heart disease who underwent surgical treatment and 29 patients with infective endocarditis were studied. Among the patients with valvular heart disease, 52 patients (21 elderly, 31 young) underwent aortic valve replacement, 46 patients (24 elderly, 22 young) mitral valve replacement, and 12 patients (6 elderly, 6 young) double valve replacement. There were only 2 operative deaths (1 elderly, 1 young). The 5-year survival rate was 91.2% in elderly patients and 92.3% in younger patients. The five-year event-free rate was 67.3% in elderly patients and 79.0% in younger patients. Among 29 patients with infective endocarditis, surgical treatment was successfully performed in six of the 13 elderly patients and 10 of the 16 younger patients. There were two deaths among the younger patients and no death among the elderly patients, although recurrence was found in 2 elderly patients. Good results can be obtained from surgical intervention in elderly patients, provided they are risk-stratified before surgery followed by appropriate management.

Adult↗