Search PubMed⌕ Search

Biomedical subjects

S Nishida

Publications and source records attributed to S Nishida.

At least 271 records · Page 15Linked to original sources
PubMed1992

[Studies on early stage changes of peroxide lipid in isoproterenol-induced myocardial injury].

The amount of peroxide lipid in vivo in the early stage of the experimental model of myocardial infarction in a rat induced by the administration of isoproterenol (Isp) was measured as the value of malonic dialdehyde (MDA). The model of myocardial infarction was made by giving 75 mg/kg of Isp to the rat weighing 270 +/- 10 g. After the administration of Isp, the amounts of lipid in the serum and in the myocardial tissue were measured, and a blood chemistry test (glutamic oxaloacetic dehydrogenase, glutamic pyruvic transaminase, lactate dehydrogenase, free fatty acid, creatine kinase) was simultaneously carried out on the serum. The value of the amount of peroxide lipid in the serum began to elevate 3 h after the administration of Isp and reached a maximum value at 6 h. The value of the amount of peroxide lipid in the tissue began to elevate 30 min after the administration and reached a maximum at 3 h. Each blood chemistry disclosed the elevation 30 min after the administration. As mentioned above, the production of peroxide lipid in vivo on the myocardial disorder in the early stage after the administration of Isp and the biochemical changes showed a significant correlation. From these results it is suggested that the myocardial disorder induced by the administration of Isp has already developed at 30 min after the administration.

Animals↗
PubMed1992

Quantitative and morphometric studies of age-related changes in human ciliary muscle.

The age-related changes in ciliary muscles were studied morphologically in 20 human eyes ranging from 3 months to 90 years of age. The meridionally cross-sectioned area and the volume of ciliary muscles increased with age until 70 years, but then decreased. The circular fiber in the ciliary muscle was undeveloped in the infantile eye. However, it continued to develop until about 70 years of age, and then decreased. The connective tissue in the ciliary muscle showed a proportional age-related increase. Over 71 years of age the proportion of connective tissue became larger than that of the muscle fiber. The number of nuclei in the ciliary muscle was maximum in eyes between 21 to 40 years of age, and subsequently there was a continuous and distinct decrease in the circular fiber with age. The age-related increase of connective tissue and decrease of nuclei in the ciliary muscle together with the decreasing circular fiber suggested a possibility of atrophy in the ciliary muscle with age-related deterioration of accommodation.

Adult↗
PubMed1992

Enzyme-histochemical identification of the human lymphatic capillary by adenylate cyclase.

This investigation was performed in order to establish a new histochemical method for the identification of lymphatic capillaries. The microvasculature in specimens from human foreskin was examined for adenylate cyclase and alkaline phosphatase activity by light and electron microscopy. Lymphatic capillaries showed positive adenylate cyclase reactivity and negative alkaline phosphatase reactivity whereas the blood capillaries showed a positive reaction for alkaline phosphatase and a negative one for adenylate cyclase. The presence of adenylate cyclase activity in the endothelium of the lymphatic capillary may relate to microvascular function including the transcapillary exchange of water and solutes.

Adenylyl Cyclases↗
PubMed1992

[Significance of the factors in wound healing for the origin of chronic subdural hematoma--fibronectin and its related substances].

The role of substances for wound healing in chronic subdural hematoma was investigated. Fibronectin, blood coagulation factor XIII (F X III), alpha 2 -plasmin inhibitor (alpha 2-PI) and alpha 2-PI plasmin complex (PIC) in hematoma fluid were measured, sixty cases of hematoma fluid (15 cases were bilateral chronic subdural hematomas) were used for analysis. The levels of fibronectin in hematoma fluid ranged widely from 40 to 1068 micrograms/ml. The levels of F XIII (except 1 case) in the hematoma fluid were less than 70% (normal plasma level 72-144%). And also the levels of alpha 2-PI in the hematoma fluid were lower than that in normal blood plasma (85-115%). Fibrin, fibronectin, alpha 2-PI and collagen crosslinks to these proteins by the catalytic action of the activated F XIII. These substrate proteins (except fibronectin) and F XIII were extremely low levels for wound healing. Histological analysis of the membrane with dura mater obtained from 13 patients was performed by Abidin-Biotin peroxidase Complex Method. Fibronectin was identified in outer membrane especially in sinusoidal layer. In normal wound healing, fibronectin appears early with the invading fibroblast and disappeares within 5 weeks from injury. But in chronic subdural hematoma it was not disappeares in 8 weeks after the head injury. The fact indicates the neomembrane of the chronic subdural hematoma is not in healing stage. This condition in chronic subdural hematoma is unfavorable for wound healing. Thus, author suspected that in early phase of wound healing after the head injury fibronectin and its related substances may play a role in the formation of chronic subdural hematoma.

Adolescent↗
PubMed1992

[Deterioration of amplitude of the accommodation with age and its possible restoration in the intraocular lens implanted eye].

This study aimed to determine whether pseudophakia which have deteriorated amplitude of accommodation with age, i.e., presbyopia and which received implantation of refractively changeable intraocular lenses after cataract extraction are able to regain accommodative function. According surveys on aging in the literature, functional deterioration of the ciliary muscle and the zonular fiber is not so striking compared to the changes of crystalline lens material and capsule. Consequently the artificially pseudophakic eye can be expected to regain accommodative function when the crystalline lens material could be replaced by an appropriately visco-elastic material before 80 years of age when the crystalline lens capsule still retain its elasticity.

Accommodation, Ocular↗
PubMed1992

[Open-heart surgery without donor-blood transfusion--a clinical study].

Since October 1987, 80 patients underwent open-heart surgery without donor-blood transfusion. 50 (Group I) out of these 80 cases were selected to be paired with 50 patients (Group II) who underwent open-heart surgery with homologous blood transfusion in the same period. Twelve cases (Group III) underwent open-heart surgery without homologous blood transfusion but were transfused after surgery. To decrease the homologous blood requirements, ultra-filtration system as well as conservation and autotransfusion of autologous blood was employed. Peripheral blood count, blood chemistry for liver and renal function were analyzed and compared among these three groups. Although hematocrit of Group I was lower than that of Group II until the third postoperative day, there was no difference after the seventh postoperative day. The platelet count was more in Group I than in Group II or III on the first and the seventh postoperative day. The level of lactate dehydrogenase was higher in Group II than in Group I. Total bilirubin was more elevated in Group II than in Group I on the first and the fourteenth postoperative day. Direct bilirubin was also higher in Group II than in Group I till fourteenth postoperative day. Five cases in Group II fulfilled the criteria of the serum hepatitis. Blood urea nitrogen and creatinine were less in Group I than in Group II. The duration of the intra-tracheal intubation was shorter in Group I than in Group II or III. There was no difference in postoperative dosage or duration of catecholamines among three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Freeze-fracture and deep etch replica of monkey ciliary muscle].

The author observed freeze fracture and deep etch replica of monkey ciliary muscle in order to study it's fine three dimensional structure. A three dimensional structure of the ciliary muscle cell and the relationship between the adjoining cells were elucidated. A lot of myofilaments which were meshy in shape were observed in the cytoplasm of ciliary muscle cells, and adhered to just beneath the cell membrane, nucleus membrane and limiting membrane of mitochondria directly. The arrangement direction of myofilaments was either parallel or oblique to the longitudinal axis of the cell, and then myofilaments formed dense bodies together with 10 nm filaments in some places. Myofilaments and 10 nm filaments also formed dense plaques together just beneath the cell membrane. Myofilaments and 10 nm filaments suggested to concern the cytoskeleton and the functional characteristics of the ciliary muscle cell.

Actin Cytoskeleton↗
PubMed1992

[Functional pulmonary atresia: a case report].

A male neonate, two days of age, was admitted with cyanosis and tachypnea. Chest roentgenograms showed massive cardiomegaly and decreased pulmonary vasculatures. Echocardiographic and the right ventriculographic findings were interpreted as showing primary pulmonary atresia with secondary tricuspid incompetence. At a Brock operation, however, there was no resistance in passing the instrument through the pulmonary valve. The baby died twelve hours after surgery. Postmortem examination showed that the tricuspid regurgitation was a cause of the functional pulmonary atresia (FPA). It is important to distinguish FPA from pure pulmonary atresia because conservative therapy is the first choice for the FPA.

Diagnosis, Differential↗
PubMed1991

Thomsen-Friedenreich (T)-active glycoproteins, blood group N antigen precursor glycoproteins and N antigen precursor glycoproteins with T activity from ascitic fluids of liver cancer patients.

1. Five perchloric acid-soluble fractions (PASFs) obtained from ascitic fluids of three patients with primary hepatocellular carcinoma (HCC), a patient with liver metastatic carcinoma (LUC) from ureteral carcinoma and human normal serum (NS) were subjected to DEAE-cellulose column chromatography to separate seven glycoprotein fractions, respectively. 2. In this chromatography, two HCC-PASFs gave a Thomsen-Friedenreich (T)-active glycoprotein, respectively. 3. Other HCC-PASF gave a T-active glycoprotein, two blood group N antigen precursor glycoproteins and an N antigen precursor glycoprotein with T activity. 4. LUC-PASF gave two T-active glycoproteins and an N antigen precursor glycoprotein with T activity. 5. NS-PASF did not give these serologically active glycoproteins.

Amino Acids↗
PubMed1991

Tryptophan residues of phospholipase A2 from the venom of an Australian elapid snake (Pseudechis australis).

Tryptophan residues 31 and 69 (Trp-31 and Trp-69) in phospholipase A2 (Pa-11) from the venom of an Australian elapid snake, Pseudechis australis, were modified with N-bromosuccinimide (NBS) or with 2-nitrophenylsulphenylchloride (NPSC1). NBS oxidized only Trp-31, whereas NPSC1 reacted with both Trp-31 and Trp-69. Treatment of the enzyme with NBS at various pH values resulted in losses of enzymic and lethal activities. No protective effect on the oxidation with NBS was observed by the addition of calcium ion (20 mM) or lecithin (4 mM). The observations suggest that Trp-31 is exposed to the surface of the molecule, composes a part of the lipid-water interface recognition site around the active site and is essential for enzymic activity. Calcium ion addition to the solution caused a change in ultraviolet spectrum of the native enzyme Pa-11. The difference spectrum indicates that a charge effect caused a typical tryptophan blue shift in the Ca(2+)-enzyme complex. Pa-11 oxidized with NBS showed a smaller ultraviolet absorption difference on the addition of Ca2+ ion. The results show that the hypochromic effect induced upon the binding of Ca2+ is due to perturbation of the specific tryptophan residue (Trp-31) which is involved in the active site. Dissociation constant, Kd, of the Ca(2+)-enzyme complex was calculated to be 3.4 x 10(-4) M at pH 8.0.

Amino Acids↗
PubMed1991

Contribution of transient and sustained responses to the perception of apparent motion.

The likelihood of seeing apparent motion (AM) was measured as a function of inter-stimulus-interval (ISI) between two isolated Gabor patches separated by 4 deg with spatial frequency (0.75, 2.0 and 4.5 c/deg) and exposure duration (33 and 1000 msec) as parameters. For the short stimuli, the likelihood of AM for the low-spatial-frequency of 0.75 c/deg was higher than that for the high-spatial-frequency of 4.5 c/deg, but for the long stimuli, the former was similar to, or lower than the latter. Decreasing the mean luminance from 190 to 0.8 cd/m2 impaired AM for the short stimuli of 2.0 c/deg, but improved AM for the long stimuli. The dependencies of AM on spatial frequency, exposure duration and adaptation level may be ascribed to the changing contribution of the transient and the sustained responses.

Adaptation, Ocular↗
PubMed1991

Method for predicting an EEG waveform as an aid to the accurate recording of evoked potentials.

Evoked potentials are the brain's responses to incoming stimuli and are usually recorded under noisy circumstances. To improve the signal-to-noise ratio, signal averaging has been widely applied to the recorded data, but an improved method is required. A method of EEG waveform prediction for the accurate recording of evoked potentials is proposed, and an electroencephalographic waveform predicted by using an EEG model and a nonlinear exponentially weighted least squares method, subtracting the predicted EEG waveform from the raw data and extracting the evoked waveform. By the use of this method, we have successfully predicted the EEG waveform and detected the evoked potential with only a small number of averages.

Adult↗
PubMed1991

Deterioration of average evoked potential waveform due to asynchronous averaging and its compensation.

In order to improve the signal-to-noise ratio of evoked potentials, the responses to repetitive stimuli are usually recorded, and the averaging method is applied to them. If each starting point of the averaging varies with respect to the response because of asynchronous sampling of the measurement data, the average waveform of the evoked potential signal is distorted by the averaging. We analyzed the asynchronous averaging in the frequency domain and derived a relationship between the fluctuating time and the degree of the deterioration. By using this relationship, a required sampling rate was derived to ensure the accuracy of the averaging. Furthermore, we also deduced a compensation procedure for the asynchronous averaging in case of coarse sampling.

Evoked Potentials↗
PubMed1991

Antiplatelet glycoprotein Ib monoclonal antibody (OP-F1) totally abolishes ristocetin-induced von Willebrand factor binding, but has minimal effect on the botrocetin-induced binding.

We describe here a new antiplatelet glycoprotein (GP) Ib monoclonal antibody (MoAb) designated OP-F1 (IgG1 kappa). Both OP-F1 and a well-characterized anti-GPIb MoAb, AP-1, totally abolished ristocetin-induced von Willebrand factor (vWF) binding to platelets and desialylated vWF binding to platelets at an IgG concentration of 2-8 micrograms/ml. AP-1 also blocked snake venom botrocetin-induced vWF binding at a similar IgG concentration, whereas OP-F1 had a minimal effect on botrocetin-induced binding. At a higher IgG concentration (150 micrograms/ml), OP-F1 inhibited botrocetin-induced binding by 50%. AP-1 (IgG) did not interfere with binding of [125I]OP-F1 (IgG) to platelets. Thus, the epitope involved in the binding of OP-F1 or AP-1 appears to be quite different. These results suggest that the vWF binding site(s) on the GPIb molecule generated by these inducers is in close proximity but not completely identical.

Antibodies, Monoclonal↗
PubMed1991

Effects of changes in angiotensin converting enzyme activity on renin release: pretreatment with dexamethasone enhances a plasma renin activity response to captopril in normal subjects.

Healthy adults were given captopril (25 mg and 75 mg) po with or without dexamethasone (DXM) pretreatment (1 mg po 2 h before and simultaneously with the captopril). We determined the serum potassium and sodium concentrations, plasma prostaglandin E2 level, PRA, serum angiotensin converting enzyme (ACE) activity, and aldosterone level from 20 min before to 120 min after administration of captopril. DXM pretreatment stimulated the PRA response to captopril. This stimulation was suppressed by indomethacin. However, the administration of DXM did not induce a consistent rise in the prostaglandin E2 level. The administration of DXM induced a significant rise in the potassium concentration, but since simultaneous administration of indomethacin with captopril induced the suppression of PRA without affecting the potassium level, the PRA increase in response to captopril with DXM was not caused directly by the potassium increase. There were no significant differences in the PRA increase between 25 mg captopril and 75 mg captopril, or between DXM-25 mg captopril and DXM-75 mg captopril, though the inhibitions of ACE activity by captopril differed according to dose. The PRA increases, but not the captopril-induced inhibition of ACE activity, were significantly different between captopril alone and captopril with DXM pretreatment at either dose of captopril. Thus, the inhibition of ACE activity perhaps allows PRA to increase in response to captopril. These results suggest that the DXM stimulation of PRA may have been dependent on the inhibition of ACE activity by captopril.

Adult↗