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Biomedical subjects

K Goto

Publications and source records attributed to K Goto.

At least 469 records · Page 26Linked to original sources
PubMed1994

Loss of contractile activity of endothelin-1 induced by electrical field stimulation-generated free radicals.

1. Electrical field stimulation (EFS; 10 V, 10 Hz, 2 ms) of porcine coronary artery strips precontracted with 10 nM endothelin-1 (ET-1) for 5 min caused a biphasic response, consisting of a slight contraction during EFS and a marked and irreversible relaxation just after EFS. This irreversible relaxation after EFS has never been investigated. In the present study, we have investigated the mechanism of the relaxation after EFS. 2. The EFS-induced response was not affected by the presence or absence of endothelium and was insensitive to 10 microM tetrodotoxin (TTX). 3. In the presence of free radical scavengers (40 u ml-1 superoxide dismutase (SOD), 1200 u ml-1 catalase or 80 mM D-mannitol), the relaxation after EFS was significantly inhibited. Moreover, relaxation after EFS was not observed in porcine coronary artery strips precontracted with 20 mM KCl. 4. In a cascade experiment, EFS of Krebs-Ringer solution containing 10 nM ET-1 induced marked suppression of the contractile activity of ET-1 in porcine coronary artery strips, which was in accord with the observed decrease in release of immunoreactive ET-1 (ir-ET-1). This effect of EFS was significantly inhibited by each of the free radical scavengers, 3 mM vitamin C, 40 u ml-1 SOD, 1200 u ml-1 catalase and 80 mM D-mannitol. 5. The exchange of 95% O2/5% CO2 gas for 95% N2/5% CO2 gas significantly inhibited the EFS-induced decrease in release of ir-ET-1. 6. Neither superoxide anions generated by xanthine (10 JM) plus xanthine oxidase (0.1 micro ml-1) nor hydrogen peroxide (10 microM) exogenously added to Krebs-Ringer solution containing 10 nM ET-1 affected the level of ir-ET-1.7. Generation of hydroxyl radicals was detected in the EFS-applied Krebs-Ringer solution. The EFS-induced generation of hydroxyl radicals was dependent on the period of stimulation and 02-bubbling, and significant generation of hydroxyl radicals was detectable with stimulation of over 5 min.Moreover, hydroxyl radicals generated in 50 mM NaCl solution containing 10 nM ET-1 by H202 plus Fe2 , i.e. the Fenton reaction, significantly decreased the level of ir-ET-l.8. These findings suggest that oxygen-derived hydroxyl radicals generated by EFS of porcine coronary artery strips inactivate ET-1, probably by structural modification. Thus, porcine coronary artery strips precontracted with ET-1 are potently relaxed by EFS.

Animals↗
PubMed1994

Endothelin receptor subtypes in human versus rabbit pulmonary arteries.

We studied which endothelin (ET) receptor subtypes mediate ET-1-induced vasocontraction in the human pulmonary artery (PA) compared with the rabbit PA. ET-1 produced potent contraction in both human and rabbit isolated PAs. In human PA, ET-1-induced contraction was competitively antagonized by BQ-123 (an ETA receptor antagonist) with a pA2 value of 7.68. In rabbit PA, however, even a high concentration of BQ-123 (1 microM) did not affect the contraction. BQ-3020 (an ETB receptor agonist) produced potent contraction in rabbit PA but not in human PA. Binding assays of the membrane preparations showed that human and rabbit PAs contained ETA and ETB receptors in ratios of 93:7 and 23:77, respectively. These results suggest interspecies differences in the ET receptor subtypes that mediate ET-1-induced vasocontraction; ETA receptors are dominant in the human PA, whereas ETB receptors are dominant in the rabbit PA. Furthermore, the predominance of ETA receptors in human PA was supported by autoradiographical studies. If ET-1 acts as a physiological and/or pathophysiological vasocontractor in the human pulmonary circulation, an ETA receptor antagonist would function as a pulmonary vasodilator in humans.

Aged↗
PubMed1994

Alteration of plasma endothelin-1 by exercise at intensities lower and higher than ventilatory threshold.

The purpose of this study was to investigate whether the release of endothelin-1 (ET-1), a potent vasoconstrictor peptide produced by vascular endothelial cells, is induced by exercise. Venous plasma concentrations of ET-1 were measured by sandwich-enzyme immunoassay before and after endurance exercise with a cycle ergometer at different intensities. Male intercollegiate athletes participated in the study and performed cycle ergometer exercise of 30 min duration at intensities of 90 or 130% of their individual ventilatory threshold (VT). The plasma concentration of ET-1 was slightly but significantly increased after exercise at 90% and markedly increased after exercise at 130% of individual VT. The increase in ET-1 was greatest 30 min after exercise at both intensities. It was first demonstrated that the plasma concentration of ET-1 was significantly increased after exercise: the greater the intensity, the greater the extent of the increase in plasma ET-1 concentration. However, the precise physiological roles of ET-1 during exercise remain to be elucidated.

Adolescent↗
PubMed1994

Proliferating cell nuclear antigen in needle biopsy specimens of prostatic carcinoma.

The expression of proliferating cell nuclear antigen (PCNA) was immunohistochemically determined using a monoclonal antibody PC10 in 54 prostatic carcinoma samples. The samples were taken from needle biopsy specimens which had been paraffin-embedded after routine fixation with 10% formaldehyde solution (formalin) for less than 24 h. The PCNA index was calculated as the percentage of positive tumor cell nuclei. There was a significant difference in the PCNA index according to the growth pattern (p < 0.001), nuclear anaplasia (p < 0.001) and T stage (p < 0.01). Regarding the growth pattern, solid carcinomas showed a significantly higher PCNA index than did either separate gland carcinomas (p < 0.05) or trabecular/fused gland carcinomas (p < 0.05). The PCNA index correlated closely with either the nuclear anaplasia or T stage, and increased in conjunction with the increased nuclear anaplasia (rs = 0.641; p < 0.001) or T stage (rs = 0.435; p < 0.01). The patients in the high PCNA index (> or = 15%) group showed a significantly worse survival than did those in the lower PCNA index group (p < 0.01), and multivariate analyses indicated that the PCNA index had an independent prognostic significance. These results suggest that the PCNA index, as determined by PC 10 on needle biopsy specimens of prostatic carcinoma, can thus be an objective and quantitative means for evaluating the biological malignancy of prostatic carcinoma.

Adenocarcinoma↗
PubMed1994

Urinary levels of gamma-carboxyglutamic acid and its clinical significance.

Urinary gamma-carboxyglutamic acid (gamma-Gla) levels were determined in healthy subjects of all ages. The urinary gamma-Gla levels were highest in infants (0-1 years), then fell in an age-dependent manner, again in subjects reaching a minimum value in adults, then gradually increased over 60 years of age. Urinary gamma-Gla levels therefore change markedly with aging. The relationships between the urinary gamma-Gla excretion and plasma levels of prothrombin and protein C in patients with various hepatic diseases or diabetes mellitus were examined and compared with those in healthy adults. Both plasma prothrombin and protein C levels were decreased in all patients with liver disease compared with healthy adults. In patients with hepatitis and liver cirrhosis, the decrease did not, however, affect the gamma-Gla excretion. In addition, in patients with hepatoma or carcinoma with liver metastases, the urinary gamma-Gla levels were increased. In patients with diabetes mellitus, the urinary gamma-Gla levels and plasma levels of prothrombin and protein C tended to increase, but this was not significant. The present results indicate that simultaneous measurement of the levels of urinary gamma-Gla and plasma prothrombin and protein C is a useful tool for the diagnosis of liver diseases and diabetes mellitus.

1-Carboxyglutamic Acid↗
PubMed1994

Viability of one-cell bovine embryos cultured in vitro: comparison of cell-free culture with co-culture.

In this study, the quality (number of cells) and pregnancy rates of bovine blastocysts produced by in vitro maturation/in vitro fertilization (IVM/IVF) following cultivation in either cell-free culture or co-culture were compared. Bovine one-cell IVM/IVF embryos obtained 6 h after insemination were stripped of cumulus cells and assigned to either cell-free culture or co-culture with granulosa cell monolayers for 9 days (Expt 1) or 10 days (Expts 2 and 3). In Expt 3, day-7 (day 0 = day of insemination) blastocysts, day-8 expanded blastocysts and day-9 hatched blastocysts were air-dried, fixed and stained to determine the number of cells. Expanded blastocysts obtained in Expt 1 were cryopreserved using propylene glycol as a cryoprotectant and were used later for embryo transfer. There were no significant differences between cell-free culture and co-culture in the percentage of one-cell embryos that developed to 2- to 16-cells (66.7% versus 72.4% for Expt 1, 71.0% versus 78.2% for Expt 2). However, significantly more (P < 0.05) of the one-cell embryos co-cultured with granulosa cell monolayers developed to morula, blastocyst and expanded blastocyst stages compared with those in cell-free culture (35.0 versus 27.1%, 25.1 versus 14.2%, 15.6 versus 5.4% for Expt 1; 37.6 versus 24.0%, 25.7 versus 11.0%, 16.8 versus 3.0% for Expt 2). Only embryos co-cultured with granulosa cell monolayers hatched (Expt 2). Embryos co-cultured with granulosa cell monolayers also had higher (P < 0.01) numbers of cells (92 +/- 42 versus 56 +/- 21 for blastocysts, 149 +/- 53 versus 81 +/- 29 for expanded blastocysts).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Comparison of polymerase chain reaction and culture methods for detection of Mycoplasma pulmonis from nasal, tracheal and oral swab samples of rats.

The polymerase chain reaction (PCR) and culture methods were used to detect Mycoplasma pulmonis in nasal, tracheal and oral swab samples of rats derived from 5 mycoplasma-contaminated and 2 mycoplasma-free facilities, and the results of both methods were compared. Thirty-four/54 and 30/54 in nasal samples, 31/54 and 28/54 in tracheal samples, and 12/39 and 30/39 in oral samples were positive in PCR and cultures, respectively. Agreements in the results of both tests were 48/54 (88.9%) in nasal samples and 49/54 (90.7%) in tracheal samples. This indicates that nasal and tracheal samples are useful for detecting M. pulmonis by PCR. The detection number for M. pulmonis from the oral cavity by PCR was remarkably lower than those of nasal and tracheal sites. These results show that the PCR method has significant potential as a rapid and sensitive method for detecting M. pulmonis in clinical samples collected from the nasal cavity and trachea.

Animals↗
PubMed1994

[A case of facioscapulohumeral muscular atrophy presenting unusual squatting gait, associated with tongue atrophy and sensorineural hearing loss].

A 16-year-old girl has presented speaking disturbance since early in life. Difficulty in running was noted at the age of 7. Her mother (46 years old) had moderate facial weakness and mild proximal weakness of the upper and lower limbs. Neurological examination at age 9 revealed bilateral facial weakness, tongue atrophy and weakness of the shoulder girdle, upper arms, and thighs. Deep tendon reflexes were absent in the four limbs. Gait was waddling. Over the next several years, she developed wasting and weakness around the shoulder girdle, upper arms, thighs, and increased lordosis. She lost the ability to walk by age 13. Since then, she has moved with difficulty in a squatting position. Serum CK was moderately increased and needle EMG in the extremities revealed myopathic changes. Muscle CT demonstrated marked atrophy of the proximal muscles in the left arm and lower limbs and mild atrophy of the calves. Audiogram showed bilateral mild sensorineural hearing loss. Muscle biopsy of the quadriceps at age 9 showed nondiagnostic findings. This case could be diagnosed as congenital facioscapulohumeral muscular dystrophy. Tongue atrophy and sensorineural hearing loss are rarely associated with this syndrome, as well as unusual squatting gait.

Adolescent↗
PubMed1994

[A case of mitral valve replacement with chronic idiopathic thrombocytopenic purpura after high-dose immunoglobulin infusion].

A 60-year-old female patient diagnosed as having mitral stenosis with chronic idiopathic thrombocytopenic purpura (ITP), with a platelet count of 6.8 x 10(4)/mm3, was scheduled to undergo mitral valve replacement. High-dose immunoglobulin infusion (400 mg/kg/day for five days) was begun four days before the operation and increased the platelet count to 9.1 x 10(4)/mm3 just before the operation. Intraoperative hemostasis was excellent, and the postoperative course was uneventful. High-dose immunoglobulin therapy appears to be a first choice for controlling hemorrhagic tendency in ITP patients undergoing heart surgery.

Female↗
PubMed1994

[A case of carcinomatous meningitis from transitional cell carcinoma of the urinary bladder].

We report a case of carcinomatous meningitis from transitional cell carcinoma of the urinary bladder. A 70-year-old man with invasive bladder cancer and multiple pulmonary metastases received 3 courses of systemic M-VAC (methotrexate, vinblastine, doxorubicin, and cisplatin) chemotherapy, after which the primary tumor and pulmonary metastases diminished in size and number. During the 4th course of chemotherapy, he complained of nausea, headache, diplopia, and neck stiffness. Computer tomographic (CT) scan of the brain showed no evidence of parenchymal metastases, cerebral hemorrhage, or infarction. Cerebrospinal fluid examination revealed an increase in cells along with elevated protein and depressed glucose concentrations, but no malignant cells were identified. He died two weeks after the onset of neurological symptoms. Autopsy revealed numerous tiny metastatic lesions in the leptomeninx, so called carcinomatous meningitis, without parenchymal metastases in the brain. Although metastases to the central nervous system from transitional cell carcinoma of the bladder, especially carcinomatous meningitis rarely have been reported, this unusual complication will be seen more frequently with the development of more effective systemic chemotherapy such as M-VAC.

Aged↗
PubMed1994

Detection of Bacillus piliformis by specific amplification of ribosomal sequences.

In an effort to explore a sensitive species-specific detection system using the polymerase chain reaction (PCR) for B. piliformis, we sequenced 16S ribosomal DNA (rDNA) of the organism (MSK strain) isolated from the mouse and compared it with known rDNA sequences of the RJ strain isolated from the rat. Sequence homology between the MSK strain and the RJ strain was over 97%, but homology between the MSK strain and other bacterial species was less (70-83%). The results indicated that the sequences included B. piliformis species-specific regions. On the basis of the sequences, we designed a PCR primer set which amplifies B. piliformis rDNA specifically. The PCR with the primer set detected not only these two strains but also an HN strain of hamster origin, although it did not detect other organisms. Therefore, this primer set was considered to be specific for B. piliformis species. More than one organism (RJ strain) could be detected by the PCR method. Nine Jcl:Wistar rats were infected perorally with 2x10(4) RJ strain organisms, and three rats each were sacrificed on days 1, 3 and 5 postinoculation (p.i.) to investigate the presence of the organism in the liver, heart, cecum, spleen and mesenteric lymph nodes by PCR and the immunofluorescence test. On days 1 and 3 p.i., B. piliformis was not detected in any tissues of the six rats, but B. piliformis was detected in two of the three rats sacrificed on day 5 p.i. The presence of the pathogen was seen in both liver and heart (1/3), or in the cecum (1/3) by both methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Emergency operation and perioperative management for a patient with strangulated ileus and shock associated with Rubinstein-Taybi syndrome].

A 21-year-old white male with Rubinstein-Taybi syndrome (RTS) underwent emergency laparotomy and volvulus reduction for a strangulated ileus. Low blood pressure, rapid heart rate and dusky skin color indicated that he was in a hypovolemic and/or septic shock state. Communication with the patient was impossible because of severe mental retardation, deafness, and blindness, and he was quite combative and agitated. Because of an urgent situation and in anticipation of a great risk of regurgitation, no sedatives or anesthetics were used for induction of anesthesia. A large dose of vecuronium with a priming principle technique was the only agent used for endotracheal intubation. Vigorous fluid replacement and appropriate catecholamine therapy were required for the perioperative management and recovery from the shock state. Any cardiac episodes which have been reported in patients with RTS, such as supra-ventricular or ventricular arrhythmia, did not occur throughout the perioperative period. Lack of communication with the patient was an obstacle in the postoperative care, such as respiratory management or the estimation for the timing of extubation. In conclusion, the preparations for a possibly difficult airway and the possible occurrence of arrhythmia were thought to be prudent for the management of the patient with RTS.

Adult↗
PubMed1994

HTLV-I seroprevalence in patients with undefined uveitis in central Japan.

Recently, human T-lymphotropic virus type I (HTLV-I) has been shown to cause endogenous uveitis, HTLV-I associated uveitis. To investigate the association of hereditary or environmental factors with the incidence of this uveitis, HTLV-I seroprevalence was studied in patients with undefined uveitis in central Japan, where HTLV-I infection has not been considered highly endemic. Of 129 patients with undefined uveitis, 6 (4.6%) were seropositive, and 4 of these 6 seropositive cases with undefined uveitis were born in southwestern Japan, where HTLV-I infection is highly endemic. As regards the incidence rate of uveitis, 4 of 9 (44.4%) seropositive cases from southwestern Japan developed uveitis, whereas only 2 of 21 (9.5%) seropositive cases from central Japan developed uveitis. The difference was statistically significant (P < 0.05). This results suggests that the incidence of HTLV-I associated uveitis could be influenced by environmental or hereditary factors including HLA.

Adolescent↗
PubMed1994

A retrospective study of herpes simplex keratitis over the last 30 years.

The clinical features of herpes simplex keratitis seen in 370 eyes of 356 patients (211 males and 145 females) in the outpatient clinic of the Yokohama City University hospital during the last 30 years (1963-1992) were statistically analyzed. The age of patients ranged from 1 to 75 years (mean 38.4 years). Bilateral herpetic keratitis was seen in 11 patients (10.4%) in the period of 1980-1992. Epithelial keratitis, stromal keratitis, and corneal endotheliitis were observed in 67 patients (57.3%), 46 patients (39.3%), and 4 patients (3.4%), respectively, in the period of 1980-1992. There was no significant change in the incidence of the types of corneal lesions during the last 13 years as compared with those in the previous 17 years (1963-1979). Life-table analysis revealed that 5-year recurrence rates were 17.5% in patients treated with acyclovir (ACV) and 52.9% in those treated with idoxuridine (IDU). The recurrence rate in ACV-treated patients was significantly lower than that in IDU-treated patients. Severe cases, such as those complicated by deep corneal ulcers with hypopyon, descemetoceles, or necrotizing keratitis, were decreased in number in ACV-treated patients, as compared with IDU-treated patients.

Acyclovir↗
PubMed1994

[A case of surgical treatment of sever constrictive pericarditis with biventricular failure].

A 68-year-old woman had been pointed out a calcification of pericardium on chest X-ray ten years ago. She admitted to our hospital associated with generalized edema. RA pressure.pulmonary capillary wedge pressure.RVEDP.LVEDP increased markedly and low cardiac output coexisted (C.I. = 1.77 l/min/m2). On September 9, 1992, she underwent a total pericardiectomy through mediansternotomy without cardiopulmonary bypass. She complicated a prolonged biventricular heart failure despite total pericardiectomy postoperatively. It was considered that delayed clinical improvement had based on myocardial degeneration or atrophy in long-term morbidity. We recommend a early operative intervention at the clinical hemodynamic deterioration.

Aged↗
PubMed1994

Lens-specific activity of the chicken delta 1-crystallin enhancer in the mouse.

A lens-specific enhancer was identified in the third intron of the chicken delta 1-crystallin gene by analysis based on transient transfection of primary-cultured cells. To assess the significance of this enhancer's activity in embryonic lens cells during development, tkCAT gene carrying the enhancer was introduced into mouse embryos utilizing ES (embryonic stem) cell-mediated gene transfer. In the undifferentiated culture condition, ES lines with enhancer-carrying tkCAT did not express any significant level of CAT (chloramphenicol acetyltransferase). However, when the ES cells were injected into a blastocyst and allowed to differentiate into various somatic cells of an embryo, CAT expression was observed exclusively in lens, and the expression was dependent upon the delta 1-crystallin enhancer. We concluded that the delta 1-crystallin enhancer alone is sufficient for eliciting lens-specific gene expression in developing mouse embryos and that the mechanism of lens-specific regulation effected by the delta 1-crystallin enhancer is conserved between the chicken and the mouse.

Animals↗