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Biomedical subjects

I Sato

Publications and source records attributed to I Sato.

At least 253 records · Page 14Linked to original sources
PubMed1993

Reduction of nitric oxide producing activity associated with in vitro aging in cultured human umbilical vein endothelial cell.

To investigate the involvement of nitric oxide (NO) in the pathogenesis of the cardiovascular system with aging, we studied the basal release of NO in cultured endothelial cells isolated from normal human umbilical veins (HUVECs) at different population doubling levels (PDLs). The release of NO was assayed by a newly established, highly sensitive assay system monitoring guanosine 3':5'-cyclic monophosphate (cGMP) formation in a pig kidney epithelial cell line cocultured with HUVECs. The cGMP formation by NO released from HUVECs decreased 3.3-fold between PDLs 8 (14.1 pmol/ml) and 50 (4.3 pmol/ml) (P < 0.01). The result suggests that the vaso-constrictive activity of endothelial cells increases during in vitro aging which may reflect the increased vascular disorders in aged people.

1-Methyl-3-isobutylxanthine↗
PubMed1993

Effects of acetyl salicylic acid and cilostazol administration on serum thrombomodulin concentration in diabetic patients.

Serum thrombomodulin (sTM) is an endothelial cell marker which would reflect the endothelial damage. In order to examine whether some antiplatelet agents decrease the endothelial damage in diabetic patients, sTM concentrations were measured by enzyme-linked immunosorbent assay before and after oral administration of a daily 100 mg of cilostazol for 4 weeks in 9 diabetics or a daily 81 mg of acetyl salicylic acids (ASA) for 4 weeks in 8 diabetics. Basal concentrations of sTM were elevated in most of these patients as compared with healthy subjects. The sTM concentrations were decreased after administration of cilostazol from 28.1 +/- 7.1 ng/ml to 23.6 +/- 5.4 ng/ml (p < 0.01), and after ASA from 30.7 +/- 10.9 ng/ml to 27.9 +/- 11.6 ng/ml (p < 0.05). These results suggest that such drugs can decrease the endothelial damage, resulting in the reduced risk of diabetic vascular complications.

Aged↗
PubMed1993

A carcinoid tumor of the rectum removed by strip biopsy.

In a 29-year-old male complaining of constipation, total colonoscopy revealed a 5 mm yellowish submucosal tumor at a distance of 6 cm from the anal ring. The histologic diagnosis of specimens obtained by biopsy was rectal carcinoid tumor and transanal ultrasonography revealed the tumor localization within the submucosal layer in the rectum. A strip biopsy was performed. Histopathological examination confirmed the diagnosis and ascertained complete excision. Rectal carcinoid tumors should be removed completely and strip biopsy may be a suitable procedure for removal of rectal submucosal tumors less than 10 mm in diameter.

Adult↗
PubMed1993

The effects of ketamine on the excitation and inhibition of dorsal horn WDR neuronal activity induced by bradykinin injection into the femoral artery in cats after spinal cord transection.

BACKGROUND: It is now well established that wide dynamic range neurons (WDR) can possess widespread cutaneous inhibitory receptive fields, as well as excitatory receptive fields, in specific regions of the body. The ability of ketamine to depress the excitatory responses of spinal WDR neurons indicates that the analgesia produced by this agent may be a result, in part, of this spinal action. The primary purpose of this study was to investigate the effects of ketamine on the WDR propriospinal inhibitory mechanism that is induced by a bradykinin (BK) injection as a noxious test stimuli. METHODS: In decerebrate, spinal cord-transected cats (L1-L2), the effects of a low (0.5 mg.kg-1, intravenous) and a high (10 mg.kg-1, intravenous) dose of ketamine on the neuronal activity of spinal dorsal horn WDR neurons evoked by femoral artery injection of BK (10 micrograms) was examined. Extracellular activity was recorded from single WDR neurons that responded to noxious and innocuous stimuli applied to the cutaneous receptive fields on the foot pads of the left hind paw. RESULTS: After ipsilateral BK administration, the activity of the WDR neurons was found to be increased (excited) in all ten neurons that were examined. In contrast, the activity of these neurons was found to be decreased (inhibited) in five of these ten neurons after BK administration into the contralateral femoral artery. The 10 mg.kg-1 dose of ketamine significantly suppressed the excitatory activity observed in all 15 of the WDR neurons examined. A comparison of the effects produced by the 0.5-mg.kg-1 and the 10-mg.kg-1 intravenous doses reveals that the amount of suppression was dose-related. In addition, the inhibitory WDR neuronal activity induced by contralateral BK injection was also significantly reduced by both the 0.5- and the 10-mg.kg-1 doses of ketamine. CONCLUSIONS: These results indicate that this reduction of excitatory and inhibitory responses of WDR neurons after noxious stimulation is likely to be the fundamental basis for the spinal cord component of ketamine-induced analgesia.

Animals↗
PubMed1993

Ventilatory anaerobic threshold before and after cardiac valve surgery.

The purpose of this study was to objectively assess exercise tolerance before and after cardiac valve surgery by using an objectively determined ventilatory anaerobic threshold (AT). Nine patients (mean age: 38.2 +/- 8.1 years) with predominantly mitral regurgitant lesions were studied by a symptomatic maximal treadmill exercise test which included a determination of AT. The mean lengths of time from preoperative exercise testing to cardiac surgery, and from surgery to postoperative exercise testing were 5.9 +/- 4.0 and 12.1 +/- 8.3 months, respectively. The determination of AT on data plots was performed after blinding to patient identification and pre- vs postoperative status. After surgery, the clinical symptoms and NYHA class improved significantly with a decrease in the cardio-thoracic ratio and echocardiographic diastolic dimensions. The mean peak VO2 (ml/kg/min) increased significantly from 20.2 +/- 7.1 to 29.7 +/- 7.9 (p < 0.01). Together with these changes, AT (ml/kg/min in VO2) increased from a mean of 14.8 +/- 4.8 to 22.8 +/- 5.5 (p < 0.01). In conclusion, symptomatic improvement and an increase in peak oxygen uptake after cardiac valve surgery were accompanied by a significant increase in the objectively determined AT. AT determined in a blind manner provides an objective means of evaluating exercise tolerance when a double-blind intervention cannot be performed.

Adult↗
PubMed1993

Fine structure and elemental analysis of the enamel in the cryptobranchid salamander Megalobatrachus japonicus.

Teeth from Megalobatrachus japonicus were prepared for scanning electron microscopy (SEM) and electron microprobe analyzer (EMPA) to assay the elements of the enamel layer. The enamel layer of each of tooth is thin and the arrangement of the enamel crystals is regular in the Megalobatrachus japonicus. Based on calcium, phosphate and magnesium levels of distribution, the calcification level of the enamel layer differs between the labial and lingual surfaces. Concentrations of iron and fluoride are located in both portions of the enamel layer as well. The presence of trace elements and distribution of calcified levels are related to the mineral formation in the enamel layer and function of the teeth during feeding.

Animals↗
PubMed1993

Morphological study of the teeth of Ambystoma maculatum, Salamandra salamandra and Aneides lugubris: fine structure and chemistry of enamel.

The functional teeth of adult salamander (Caudata): Ambystoma maculatum, Salamandra salamandra and Aneides lugubris were prepared for transmission electron microscopy and electron microprobe analysis of the elements and trace elements of the enamel layer. The arrangement of enamel crystals in these species is variable. The outer part of the enamel layer in which hydroxyapatite elements (Ca, P) and trace elements (e.g., F, Fe, Mg) are concentrated, is most mineralized. The concentration of trace elements are arrangement of crystals in the enamel layer differed in these species, may be related to the pattern of mineralization of enamel.

Ambystoma↗
PubMed1993

[Effects of sevoflurane on spinal dorsal horn WDR neuronal activity in cats].

The effects of sevoflurane (S) (0.5%, 1.5%, and 2.5%) on the spinal dorsal horn wide dynamic range (WDR) neuronal activity were studied in either spinal cord intact or spinal cord transected cats. Extracellular activity was recorded in the dorsal horn from single WDR neurons responding to noxious and non-noxious stimuli applied to the cutaneous receptive fields on the left hind paw foot pads of intact or decerebrate and spinal cord transsected (L1-2) cats. When BK 10 micrograms was injected into the femoral artery ipsilateral to the recording site as the noxious test stimulus in the spinal cat, 7 of 8 WDR neurons gave excitatory responses which were not depressed by sevoflurane 0.5% and 1.5% but were depressed significantly by 2.5%. On the other hand, when BK 10 micrograms was injected into the femoral artery ipsilateral to the recording site in the intact cat, 6 of 13 WDR neurons (46%) gave excitatory responses, which were significantly depressed by sevoflurane 0.5%, 1.5% and 2.5%, and 7 of 13 WDR neurons (54%) gave inhibitory responses, which were significantly depressed sevoflurane at 0.5%, 1.5%, and 2.5%. In conclusion, we have found that sevoflurane reduces the excitation as well as the inhibition of dorsal horn WDR neuronal activity induced by BK injection.

Animals↗
PubMed1993

[A successful insertion of the prosthetic valve in supraannular position concomitant with pericardial enlargement of the aortic root in a child: a case report].

A 4-year-old boy admitted to our hospital due to congestive heart failure one year after the intracardiac repair of tetralogy of Fallot. Echocardiography and cineangiography revealed severe aortic regurgitation. The aortic valve replacement was performed with a prosthesis larger than the aortic annulus. Operative findings showed that the cause of aortic regurgitation was infective endocarditis. The aortic root was enlarged with pericardial patch and a 21 mm St. Jude Medical valve prosthesis was inserted in supraannular position. This technique was very useful for insertion of a prosthetic valve one or two sizes larger than the aortic annulus without risk of distorting the mitral valve or left ventricular function.

Aortic Valve↗
PubMed1993

Ten-year complete remission in an 84 year-old patient with acute myeloid leukemia.

We report an unusual case in which complete remission of acute myeloid leukemia (AML) had lasted for almost 10 years in a patient who was 94 years and 7 months old as of September 1989. An 84 year-old man was admitted to our hospital with gingival bleeding on October 15, 1979. Hematological data were: RBC 327 x 10(4) microliters, hemoglobin concentration 10 g/dl, platelets 3.8 x 10(4) microliters and WBC 9000 microliters, including 34% blastic cells. Bone marrow aspiration showed nucleated cells 48.0 x 10(4)/microliters with 69.2% blastic cells. He was diagnosed as having AML (M2). Induction chemotherapy consisted of daunorubicin, cyclocytidine, an anhydride analogue of cytosine arabinoside, and prednisolone (DCP). Complete remission was achieved after 1 month of this therapy. After two cycles of consolidation therapy (DCP), intensification therapy (DCP) was performed twice. Thereafter, complete remission lasted without any further therapy, up to September 1989, when he died of pancreatic cancer. The prolonged disease-free survival in this extremely aged patient was attributed to the high sensitivity of leukemic cells to DCP therapy and his good performance status at the time of initial induction chemotherapy. This is the oldest patient with long-term remission, lasting for over 5 years, to be reported in Japan. If an elderly patient with typical acute leukemia has a good performance status, intensive chemotherapy should be tried at least once, while carefully controlling complications specific to the elderly.

Aged↗
PubMed1992

An immunoenzymometric assay for a CA125-like antigen, CA602.

An immunoenzymometric assay (IEMA) for a new CA125-like antigen, CA602, was developed. Five monoclonal antibodies raised against a human ovarian carcinoma cell line could detect their respective antigens in the sera of ovarian carcinoma patients. The antigen levels detected in serum by the various antibodies correlated significantly to each other, and to CA125 levels. The results of epitope analyses and combined IEMAs suggested that the epitopes recognized by these antibodies are not same, but exist on the same antigen which bears the CA125 epitope. A sensitive IEMA was developed with 602-1 and 602-6 antibodies which showed high reactivity to the CA125-like antigen. The antigen defined by these two antibodies was designated as CA602, and serum CA602 levels correlated well with CA125 levels. The CA602 antigen is a CA125-like antigen. Furthermore, the serum CA602 levels did not correlate to CA54/61 levels. The combined assays of CA602 and CA54/61 may increase the detection of ovarian carcinoma.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1992

Phosphorus-31 magnetic resonance spectroscopy of forearm flexor muscles in student rowers using an exercise protocol adjusted for differences in cross-sectional muscle area.

To assess exercise energy metabolism of forearm flexor muscles in rowers, six male student rowers and six control subjects matched for age and sex were studied using phosphorus-31 magnetic resonance spectroscopy (31P-MRS). Firstly, to adjust for the effect of differences in cross-sectional muscle area, the maximal cross-sectional area (CSAmax) of the forearm flexor muscles was estimated in each individual using magnetic resonance imaging. Multistage exercise was then carried out with an initial energy production of 1 J.cm-2 CSAmax for 1 min and an increment of 1 J.cm-2 CSAmax every minute to the point of muscle exhaustion. A series of measurements of 31P-MRS were performed every minute. The CSAmax was significantly greater in the student rowers than in the control subjects [19.8 (SD 2.2) vs 17.1 (SD 1.2) cm2, P less than 0.05]. The absolute maximal exercise intensity (J.min-1) was greater in the rowers than in the control subjects. However, the maximal exercise intensity per unit of muscle cross sectional area (J.min-1.cm-2) was not significantly different between the two groups. During mild to moderate exercise intensities, a decrease in phosphocreatine and an increase in inorganic phosphate before the onset of acidosis were significantly less in the rowers, indicating a requirement of less adenosine 5'-diphosphate to drive adenosine 5'-triphosphate production. The onset of acidosis was also significantly delayed in the rowers. No difference was observed in forearm blood flow between the two groups at the same exercise intensity (J.min-1.cm-2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Detection of alpha S1-casein in vomit from bottle-fed babies by enzyme-linked immunosorbent assay.

This study describes a sensitive enzyme-linked immunosorbent assay (ELISA) using rabbit anti-bovine alpha S1-casein antibody for the detection of commercial milk and milk-containing vomit. The antibody does not react with other human body fluids such as breast milk. The stability of alpha S1-casein antigenic activity was examined after storage at different temperatures and enzyme digestion. There was no decrease after storage for one year at room temperature but 40% of the activity was lost after 6 months at 37 degrees C. Enzyme digestion (6 hours, 37 degrees C) resulted in 65 approximately 70% loss of activity but the antibody reacted with the peptide fragments of alpha S1-casein. Vomit samples from 3 normal infants were tested by ELISA, and alpha S1-casein could be detected in 1 cm2 stain.

Animals↗
PubMed1992

The incidence of cardiac events in Japanese men with atypical or nonanginal chest pain: a prospective study on the significance of exercise testing.

The incidence of cardiac events in Japanese men (mean age 54 +/- 10 years) with atypical or nonanginal chest pain was assessed prospectively. Three groups of patients, those with typical angina (TA; n = 134), those with atypical angina (AA; n = 192), and those with nonanginal chest pain (NA; n = 311) were studied with regard to cardiac events (cardiac death or nonfatal myocardial infarction), risk factors, and results of exercise testing. The total cholesterol and high-density lipoprotein-cholesterol levels were significantly different among the three groups, but no differences were observed for other risk factors. The incidences of cardiac events were 8.5%, 2.2%, and 1.3% in the TA, AA, and NA groups, respectively (p less than 0.05) during 3.2 +/- 1.5 years. Significant ST segment changes were observed in 70.1%, 25.5%, and 18.0% of the patients in the TA, AA, and NA groups, respectively, at the time of enrollment. The risk ratio for cardiac events in a positive exercise test was 1.7 (difference not significant) for the TA group and 6.1 (p less than 0.05) for the others combined (AA and NA groups). The risk ratio adjusted for risk factors (Cox model) was 2.2 (difference not significant) for the TA group and 4.9 (p less than 0.05) for the AA and NA groups combined. In conclusion, the incidence of cardiac events in those with AA or NA chest pain was relatively low in Japan, but the independent prognostic significance of positive exercise testing was demonstrated in this group of patients.

Adult↗
PubMed1992

Age-dependent decrease in histamine H1 receptor in human brains revealed by PET.

Age-related changes in histamine H1 receptors were studied using [11C]pyrilamine or [11C]doxepin by positron emission tomography (PET). The frontal, parietal and temporal cortices showed age-related decreases in binding of approximately 13% per decade. In contrast, the thalamus showed no apparent decrease in binding during normal ageing because of its higher nonspecific binding. Post mortem studies also indicated that the nonspecific binding of [3H]pyrilamine in the thalamus was approximately 112% higher than that in the cortex. However, no significant decrease in histamine H1 receptors with age was observed by in vitro binding assays of autopsied human frontal cortex. Possible reasons are given for the larger effects of age observed in the PET study than in the in vitro post mortem binding study.

Adolescent↗
PubMed1992

Analysis of the tendinous structure in human masticatory muscles.

In the masticatory muscles, the development of bundles of the tendon was examined: they were composed of many collagen fibers and a few elastic fibers. In the masseter muscle, the property of the tendon differs in the distribution and size of collagen fibers and elastic fibers in comparison with those of other masticatory muscles. This difference is concerned with the kinetic force for the stress or the stretch of each tendon and muscle during jaw movement.

Aged↗