Search PubMed⌕ Search

Biomedical subjects

H Hayashi

Publications and source records attributed to H Hayashi.

At least 1,063 records · Page 59Linked to original sources
PubMed1992

[The analysis of subjective evaluations for hearing aids using fuzzy measure and fuzzy integral].

The important items of subjective estimations were investigated for hearing aid users. In this study, data of subjective evaluations were gathered from 166 peoples who have used a hearing aid for more than six months. Four principal factors in the subjective evaluations were found by factor analysis. Their four factors were the factor regarding loudness and noise ([S'1]), the factor regarding nature of sound and speech ([S'2]), the factor regarding feeling of fullness of sound and speech ([S'3]), and the factor regarding feeling of wear and so on ([S'4]). The model of fuzzy measure and fuzzy integral was applied to the result in order to make a mathematical model, and fifteen fuzzy measures were evaluated. Moreover, the Shapley values of four factors by fifteen fuzzy measures were solved. As a consequence, hearing aid users attach great importance to nature of sound and speech when they select their hearing aids.

Evaluation Studies as Topic↗
PubMed1992

Aminopeptidase activity of an antitumor antibiotic, C-1027.

An antitumor antibiotic C-1027, a complex protein consisting of an apoprotein and a non-covalently bound chromophore, showed some aminopeptidase activity, 1/15 (on the basis of activity per mg protein) that of porcine kidney enzyme [E.C. 3.4.11.2] by use of L-phenylalanyl 4-methyl-coumaryl-7-amide as the substrate. Neither the apoprotein alone nor the chromophore alone were active. Amastatin and bestatin but not leupeptin inhibited the activity. The enzyme activity of the holo-antibiotic, as opposed to that of the porcine kidney enzyme, was readily lost by UV irradiation, indicating that the intact structure of the chromophore was needed to maintain the native conformation of the holo-antibiotic. The cytotoxicity of the holo-antibiotic, but not that of the chromophore, to Ehrlich carcinoma cells in vitro was reduced to 1/5 by 1 microgram/ml of amastatin which alone had no effect on cell growth. The porcine aminopeptidase was not cytotoxic at all even at higher concentrations (higher enzyme activities/ml). Amastatin possibly occupied the catalytic domain of the holo-antibiotic, interfering with the binding of the holo-antibiotic with some cell-surface protein(s). Amastatin did not inhibit the holo-antibiotic to cleave isolated DNA.

Aminoglycosides↗
PubMed1992

New polyenic antibiotics active against gram-positive and gram-negative bacteria. VIII. Construction of synthetic medium for production of mono-chloro-congeners of enacyloxins.

New antibiotics enacyloxins (ENXs) are a family of non-lactonic polyene antibiotics produced by Frateuria sp. W-315. For the production of antibiotics, we had to employ two-step fermentations, the first is the production of spent medium of Neurospora crassa and the second is the production of antibiotics by Frateuria. To simplify the production of antibiotics, systematic analyses have been done on the spent medium, and factors which affect the production of antibiotics characterized. From the above results, we constructed a new medium for antibiotic production. Moreover, we could get a new antibiotic named enacyloxin IIIa (1), C33H48O11NCl (m/z 669). 1 was deduced to be one of the congeners of enacyloxins because it was similar to ENX IIa or ENX IVa both in biological and physico-chemical properties. Chlorine of 1 could be replaced by bromine, biosynthetically, and the resultant bromine-containing antibiotic also showed an antibacterial activity comparable to 1.

Acetobacteraceae↗
PubMed1992

[The successful treatment of G-CSF in autoimmune neutropenia with liver cirrhosis complicated by esophageal varices].

A 72 year-old woman was admitted to our hospital for hematoemesis. After admission, endoscopic examination showed esophageal varices with a red color sign which indicated endoscopic injection sclerotherapy (EIS). Concurrently, however, laboratory findings revealed severe neutropenia in peripheral blood, while bone marrow examination showed marked reduction of mature granulocytes with mild myeloid hyperplasia. As a result of those hematological abnormalities, EIS was halted. Concerning the pathogenesis of this neutropenia, immunofluorescence technique using flow cytometry disclosed the presence of anti-neutrophil autoantibody in the serum, giving a clinical diagnosis of autoimmune neutropenia (AIN). Thereafter, a conventional regimen of corticosteroids as an initial therapy and steroid pulse therapy as a succeeding maneuver were instituted, but in vain. As a last resort, 125 micrograms/body of rhG-CSF was given daily subcutaneously. As a consequence, significant increase in granulocyte count, though transient, was attained, which made EIS possible without any episodes of infections. It seems most likely that a high dose of rhG-CSF exerts beneficial effects as a prophylactic and therapeutic regimen against infections in patients with AIN.

Aged↗
PubMed1992

Acute inhibition of lipid transport in rat intestinal lymph by ethanol administration.

To observe the effect of acute ethanol ingestion on stable lipid transport in intestinal lymph, three groups of mesenteric lymph fistula rats were prepared. In group A rats, lipid emulsion containing 120 mumol/hr of oleate (control meal) was infused intraduodenally for 8 hr. Group B rats were infused with another lipid emulsion, which had the same basic composition as the control meal but included 0.75 g/kg body weight/hr of ethanol (alcohol meal), for 8 hr. In group C, rats were infused with the control meal for the first 4 hr, then with the alcohol meal for the next 4 hr. Lymph flow increased just after the infusion of ethanol, that is, lymph flow in group B was significantly higher than that of group A at 1 and 2 hr, and lymph flow in group C was significantly higher than that of group A at 5 hr. In group A, lymphatic triglyceride (TG) output reached a plateau of more than 30 mumol/hr after 3-hr infusion. TG output in group B was significantly lower than that in group A from 2 hr to 8 hr and was two-thirds that of group A at the plateau level. In group C, TG output was the same as in group A until 5 hr, but decreased to two-thirds of that in group A at 6 hr, 2 hr after replacing the control meal with the alcohol meal. Lymphatic phospholipid output exhibited a tendency similar to that of TG output. Comparisons of group A vs. B and A vs. C clearly demonstrated an inhibitory effect of ethanol on stable lipid transport in intestinal lymph. A 2-hr infusion was enough for ethanol to exhibit its inhibitory effect. In conclusion, stable lymphatic transport of intestinal absorbed lipid was suppressed by acute ethanol ingestion.

Animals↗
PubMed1992

Evaluation of liver tumors using fluorine-18-fluorodeoxyglucose PET: characterization of tumor and assessment of effect of treatment.

To evaluate glucose metabolism in patients with tumors involving the liver, 35 patients with liver lesions had PET using 18F-2-fluoro-2-deoxy-D-glucose (FDG). FDG (148 MBq) was injected and radioactivity of the tumor was scanned dynamically by PET. The rate constants (k1, k2, k3, k4) of FDG in a metabolic model were calculated. The results were compared to hexokinase activity in the excised tumor specimens. k3 was found to reflect tumor hexokinase activity. When k3 was used as an index (cut-off value: 0.025), it was possible to distinguish benign and malignant tumors. k4 was significantly higher in hepatocellular carcinoma. By using k3 and k4 as indices, one could assess the degree of differentiation of hepatocellular carcinoma. After treatment, k3 decreased according to the effectiveness of therapy and thus may be a useful index for quantitatively assessing tumor viability.

Adenoma, Bile Duct↗
PubMed1992

Effect of the neonatal steroid hormone treatment of rats on adult hormone levels and the reactivity of seminal vesicles to parasympathomimetic drugs.

1. Seminal vesicle reactivity to cholinergic agents, plasma testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations and seminal vesicle testosterone concentrations were determined in adult male rats treated during the first 6 h of life with 1.0 ml peanut oil (oil-treated), 1.0 mg testosterone propionate (TP-treated) or 1.2 mg 19-nor-testosterone homofarnesate (19-NT-treated). 2. At 90-100 days of age, the neonatally treated animals presented atrophied accessory genital organs and increased (TP-treated, N = 10) or unchanged (19-NT-treated, N = 11) pD2 values for acetylcholine (vehicle: 5.18 +/- 0.06, N = 10; TP-treated: 5.26 +/- 0.06, N = 10; 19-NT-treated: 5.14 +/- 0.09, N = 11), and acetyl-beta-methylcholine (vehicle: 5.19 +/- 0.07; TP-treated: 5.43 +/- 0.06; 19-NT-treated: 5.25 +/- 0.07). The relative intrinsic activity, alpha, of acetyl-beta-methylcholine increased after both hormonal treatments (vehicle: 0.85 +/- 0.03; TP-treated: 0.95 +/- 0.02; 19-NT-treated: 0.92 +/- 0.03). 3. No variation in mean adult plasma testosterone concentration was observed after neonatal treatment with either TP or 19-NT (vehicle: 752.93 +/- 273.66, N = 8; TP-treated: 459.05 +/- 88.32, N = 8; 19-NT-treated: 836.86 +/- 113.08, N = 7). However, testosterone content of seminal vesicles of adult rats was decreased in the animals treated with TP (N = 5) and 19-NT (N = 6) compared to controls. 4. These results indicate a specific effect of neonatal hormone treatment on androgen metabolism which is demonstrable in the adult.

Androgens↗
PubMed1992

[A case of prolactinoma presenting with CSF rhinorrhea and CSF otorrhea during bromocriptine therapy].

Cerebrospinal fluid (CSF) leakage is a rare complication of prolactinoma treated with bromocriptine (BC). BC is known to be effective for reducing the volume of a prolactinoma and for decreasing the serum level of prolactin (PRL). In cases of pituitary tumors, CSF leakage is thought to be caused by shunting between the subarachnoid and extradural spaces. We had a case presenting with CSF rhinorrhea and CSF otorrhea during BC therapy which was treated successfully. The mechanism and treatment of CSF leakage were studied. A 55-year-old woman complaining of nasal obstruction and headache was admitted to our hospital on Nov. 22, 1988. CT scan showed a huge intracranial mass lesion involving the sella and the supra-sellar region and invading the sphenoid sinus and ethmoid sinus. Serum PRL level was 18,000 ng/ml. The patient was diagnosed as having an invasive prolactinoma, and BC therapy (5.0 mg per day) was instituted. Three days later, CSF rhinorrhea developed, and BC treatment discontinued; radiation therapy was started. After 36 Gy irradiation the size of the tumor was same on CT, and serum level of PRL was still high. The patient underwent trans-sphenoidal operation. The tumor was removed partially and the presumed CSF fistula was repaired. The sella and sphenoid sinus were packed with fat. BC treatment was reinstituted, and the serum PRL level decreased gradually without recurrent CSF rhinorrhea. Two weeks later the patient returned complaining of bilateral hearing disturbance. With a diagnosis of exudative otitis media she underwent bilateral tympanostomy. Immediately after tympanostomy, pulsating discharge from the middle ear was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Bromocriptine↗
PubMed1992

Isolation of adult pig islet. In vitro assessment and xenotransplantation.

This study was conducted to develop an isolation method for adult pig islets and to investigate in vivo function after xenotransplantation as well as in vitro function of isolated islets. From the splenic portion of the glands (n = 20), 3277 +/- 645 islets per gram of pancreas were isolated and recovered by a five-step dextran discontinuous density gradient method. Purity of the final preparation obtained from 20 different consecutive pig pancreata was 80-90%. In vitro incubation study revealed a significant insulin release from isolated adult pig islets in response to glucose stimulation. In vitro perifusion study demonstrated a biphasic insulin response to glucose stimulation from isolated islets. Xenotransplantation of approx 2000 isolated adult pig islets into the portal vein of diabetic Wistar rats (n = 8) significantly reduced serum glucose levels from 431 +/- 24 mg/dL to 173 +/- 18 mg/dL 24 h after transplantation. This study provides a development of an isolation method for adult pig islets and demonstrates that isolated islets are viable and functioning both in vitro study and in vivo study of xenotransplantation.

Animals↗
PubMed1992

[Changes in dementia after shunt surgery for normal pressure hydrocephalus].

In order to investigate the pathogenesis of normal pressure hydrocephalus (NPH), dementia was analyzed with regard to the characteristic preoperative picture, the time when dementia improved, and what aspect of dementia was improved, retrospectively. Twenty seven patients of NPH were divided into two groups; young adult group: patients under 64 years old and geriatric group: patients above 65 years old. We found that the only difference found between these two groups was severity in dementia grading, higher in geriatric group. Postoperative course or complications did not differ. Dementia in NPH was not an essential impairment of intellectual ability, but was characterized by the subset symptoms of dementia, such as decrease in spontaneity and interest, slowness and paucity of thought and action. Improvement of memory followed postoperative recovery of these subset symptoms which was observed at earliest three days after shunt surgery. We postulate that recovery of dementia in NPH is associated with not only a decrease in intracranial pressure but also an improvement in the microcirculation of the brain or an improved metabolism.

Adult↗
PubMed1992

Permeability of brain structures and other peripheral tissues to prostaglandins D2, E2 and F2 alpha in rats.

Parenchymal tissue-uptake (TU) and permeability-surface area (PS) product of [3H]prostaglandins (PG) D2, E2 and F2 alpha [1.85 MBq, 0.5 mg/kg (270 nmol)] were examined in 98 regions of the brain and in 19 other tissues of urethane-anesthetized male rats (180-200 g) 15 sec after i.v. administration with [14C]dextran [0.185 MBq, 0.6 mg/kg (2 nmol)] used as a blood spacer. Slight and insignificant change in blood volume was observed in most of the tissues and brain regions between vehicle- and PG-administered groups. TU for the three PG was markedly high in kidney and lung (2388-3952 ng/g), exceeding the blood concentration (2021-2320 ng/ml), but low (less than 10% of the blood concentration) in epididymis, epididymal fat, testis (59-163 ng/g), brain and spinal cord (33-67 ng/g). TU in brain were detected about 0.1% of the administered PG. Based on a two-compartment model, the PS product for the three PG ranged from 0.75 to 4.16 microliters/g/sec in the latter tissues. The value of brain was 1.22 +/- 0.18 microliters/g/sec for PGD2, 1.69 +/- 0.05 for PGE2 and 1.33 +/- 0.13 for PGF2 alpha, indicating that PGE2 enters the brain more readily than PGD2 and PGF2 alpha. In various brain structures, the ranges of the PS product were large and completely overlapped among the three PG (PGD2, 0.14-1.56 microliters/g/sec; PGE2, 0.05-1.78; PGF2 alpha, 0.05-1.82). The highest PS product for the three PG was found in olfactory bulb and cerebellum (0.96-1.82 microliters/g/sec) and the lowest was in septum (0.05-0.53). However, the level of the PS product was different among the PG in each brain region as follows: PGD2 greater than PGE2, PGF2 alpha in septum and anterior part of pyriform cortex; PGE2 greater than PGD2, PGF2 alpha in olfactory bulb, frontal cortex, basal forebrain, middle part of pyriform cortex, thalamus, hippocampus and lateral neocortex; and PGF2 alpha greater than PGD2, PGE2 in posterior part of pyriform cortex, hypothalamus, amygdala and entorhinal and retrosplenial cortices. Low correlation coefficients (0.708, 0.522 and 0.562 for PGD2, PGE2 and PGF2 alpha, respectively) between the PS product and cerebrovascular volume in various regions revealed heterogeneous cerebrovascular permeabilities of PG.

Animals↗
PubMed1992

[Evaluation of diet of calcium stone patients].

To clarify the relationship between renal stone formation and the diet, the consumption of various nutrients of calcium stone formers was investigated. The study included 24 male and 12 female stone formers, between 20 and 78 years old (mean 42 years). The daily consumption of nutrients was compared to the daily nutritive requirement for the Japanese. The amounts of total and animal protein ingested by all the patients were significantly larger than the daily nutritive requirements. The animal protein ratio was also significantly higher. Concerning the total protein, animal protein and animal protein ratio, male and female patients showed similar results. Salt consumption was significantly larger for all the patients and the male patients than the daily nutritive requirement for the Japanese. Female stone formers also showed this tendency. Consumption of calcium and carbohydrate by all the patients and the male patients was significantly smaller than the daily nutritive requirement. This tendency was observed for the female patients.

Adult↗
PubMed1992

Cardiac-related sympathetic nerve activity during circulation with only the left ventricular assist device.

Circulatory maintenance with a left ventricular assist device (LVAD) alone during cardiac arrest until heart transplantation has been evaluated. To assess the effect on the autonomic nervous system, the sympathetic neurogram was analyzed by power spectrum and coherence function. LVAD were inserted between the left atrium and the descending aorta in seven adult mongrel dogs and ventricular fibrillation was induced electrically. Renal sympathetic nerve activity (RSNA) was detected by bipolar electrodes attached to the left renal sympathetic nerve. Values of squared coherence between the arterial pulse wave and RSNA were calculated. Under the condition of circulatory maintenance with only LVAD, coherence at the cardiac rhythm frequency was decreased, and coherence at the LVAD pumping rhythm frequency was increased. These results indicate that the arterial pulse wave observed during maintenance of the circulation with only LVAD contributed to the sympathetic neurogram.

Animals↗
PubMed1992

Co-deletions of the retinoblastoma gene and Wilms' tumor gene and rearrangement of the Krev-1 gene in a human insulinoma.

We found deletions of both alleles of the retinoblastoma gene (Rb) and the candidate Wilms' tumor gene (WT33) in a surgically resected human insulinoma by blot hybridization. Rearrangement of Krev-1, a transformation suppressor gene, was also detected in this case. The clinical and histological findings suggested that this tumor would be a benign insulinoma. The result suggests that the inactivation of multiple tumor suppressor genes could be involved even in the development of benign human tumors.

Aged↗
PubMed1992

Three stages of copper accumulation in hepatocellular lysosomes: X-ray microanalysis of copper-loaded golden hamsters.

Male golden hamsters were loaded with copper by supplying them for up to 12 weeks with drinking water containing 0.5% cupric acetate. The copper feeding increased hepatic copper to widely varying levels. Energy dispersive X-ray microanalysis could always identify a copper-sulphur complex in the hepatocyte lysosomes of copper-loaded hamsters and the X-ray intensity of copper was found to be a reliable parameter to measure in-situ copper accumulation. Combining this parameter with the copper binding ratio expressed by delta Cu/delta S enabled us to discern two stages of sub-histochemical copper accumulation. The first stage was marked by low levels of both lysosomal copper and binding ratio, which suggested that this initial copper transfer was mediated by unsaturated cuproproteins. The second stage was characterized by median amounts of lysosomal copper and a binding ratio of more than 0.50. At the third stage, histochemically detectable copper appeared in animals whose lysosomal copper was extraordinarily high in later experimental periods. With the copper binding ratio being in the same range of 0.50-0.83, it seemed that saturated cuproproteins were the main mediator of copper transport in the later two stages.

Animals↗
PubMed1992

[Monthly variation of viable count and coliforms count of sandpits in parks].

Field and experimental microbiological investigations of samples from sandpits from 5 parks were performed 2 times a month for 1 year, January-December 1990. Total viable count from the sandpits was highest in the surface layer sample than the inner layer throughout the year. However, there was no such tendency in the number of Coliforms and Enterobacter, Escherichia coli, Citrobacter. The number of bacteria on the surface and inner layer was high from April to June, and in September and October, while it was low in July and August. The proportion of Coliform bacteria represented in the total viable count ranged from 2.1 to 8.9% in the surface layer and from 1.6 to 19.6% in the inner layer. There was a significant correlation between the numbers of bacteria on the surface and inner layer. Relationships between the total viable count and Coliform count and between Coliform count and E. coli, Enterobacter and Citrobacter were also observed. In view of the results it can be concluded that park sandpits are not, from a hygienic point of view, to be an ideal environment for children to play in.

Colony Count, Microbial↗