Measurement of equilibrium beam polarization in the KEK e+e- storage ring TRISTAN.
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Journal Article↗
Biomedical subjects
T Kawamoto
Publications and source records attributed to T Kawamoto.
Absorption of cadmium after a long-term oral administration of cadmium to dogs.
A long-term experiment using beagle dogs to investigate the absorption of cadmium was conducted. The dogs in the experimental groups were given a commercial diet and pelleted food containing 1, 3, 10, 50, and 100 mg of cadmium per day. The cadmium concentration in the blood increased continuously, gradually reaching a steady state following the administration of cadmium. The cadmium excreted daily in urine increased continuously. The cumulative excreted amount of cadmium in urine was calculated by using the trapezoidal rule based on the data of excretion of cadmium in urine. Then the absorbed fraction of administered cadmium was estimated on the basis of the relationship between the cumulative excreted amount of cadmium in urine and the cumulative administered dose of cadmium after the cadmium concentration in blood reached a steady state. The absorbed fraction of cadmium decreased with an increase in the administered dose of cadmium. A dose-dependent increase between the absorbed amount and the administered dose was observed.
Administration, Oral↗
Toxic effects of ingested lead shots in domestic fowls.
Lead poisoning from ingested shots is thought to be a major cause of high mortality in waterfowls throughout the world, and some millions of fowls die each year. However, there have been no other Japanese studies regarding lead toxicity in birds from ingested lead shots. We used domestic fowls instead of waterfowls as the experimental birds, in order to make clear the distribution and the toxic effects of lead shot in the birds. In a 1-wk follow-up study, two, four, and eight #4 lead shots were administered orally. A dose-dependent increase of the lead concentrations in blood, brain, liver, kidney, lung, spleen, bone, and epidermis of the gizzard was observed. In the 12-wk follow-up study, twenty domestic fowls were used and eight #4 lead shots were administered to the experimental birds. Lead concentrations in brain, liver, kidney, bone, ovary, fat tissue, and breast muscle increased more than in the 1-wk follow-up study. The observed lead concentrations of organs in the domestic fowls were lower than those of the other species used in past studies. The blood lead concentrations increased up to the third week and a remarkable suppression of delta-aminolevulinic acid dehydratase activity in red blood cells and elevation of free erythropoietic protoporphyrin were observed in the exposed group. Body weight loss, loss of hair, and neurological symptoms were also observed. However, there were no mortalities during the 1- and 12-wk studies.
Administration, Oral↗
Isolation of a full-length cDNA encoding mouse aromatase P450.
A full-length cDNA clone for aromatase P450 has been isolated from a pregnant mouse ovarian cDNA library. The insert of this clone (2394 bp) contains a 1509-bp open reading frame encoding 503 amino acid residues together with a 46-bp 5'-untranslated stretch and an 839-bp 3'-untranslated region to which a poly(A) tract is attached. Northern blot analysis of ovarian RNA from pregnant mice reveals a major mRNA band of 2.5 kb with a minor band of 2.1 kb. Comparison of mouse aromatase P450 with that of rat, human, and chicken shows 91, 81, and 69% identity in the nucleotide sequence and 92, 79, and 69% identity in the deduced amino acid sequence, respectively. The membrane-spanning domain of mouse aromatase P450 is estimated to be an extremely hydrophobic segment located within the N-terminal region of the molecule. Furthermore, a highly conserved heme-binding domain is noticed.
Amino Acid Sequence↗
Selective depletion of immature thymocytes by oral administration of ethylene glycol monomethyl ether.
Although immunotoxicity of ethylene glycol monomethyl ether (EGME) has been strongly suspected, functional evaluation of the immune response in EGME-treated animals was negative in previous studies. We observed a decrease in thymic cellularity and increases in the various ex vivo immunological assays in mice, orally administered with EGME 0.5 or 1.0 mg/g body weight daily for 5 or 10 days: ex vivo lymphoproliferative responses to concanavalin A, in vitro induction of trinitrophenyl (TNP)-specific cytotoxic T-cell activity of thymocytes and splenocytes. Histopathological examination of the thymus of the treated mice disclosed a markedly atrophic cortex and almost intact thymic medulla. Study of thymocyte surface markers revealed that CD4+/CD8+, Thy-1+, PNA+ immature thymocytes were relatively decreased in EGME-gavaged mice and that, thus, ratios of CD4-/CD8+, H2+ mature thymocytes were enriched. These findings indicate that oral administrations of EGME selectively deplete immature thymocytes in mice. Although the mechanism of action remains unknown, the EGME-induced immature thymocyte depletion is not considered to be due to lymphocidal action of corticosteroids.
Administration, Oral↗
Expression of c-erbB-2 gene product in urinary bladder cancer.
Expression of the c-erbB-2 gene product and the epidermal growth factor receptor (EGF-R) was investigated in 54 cases of human bladder cancer immunohistologically and by Western blot analysis. For detection of the c-erbB-2 product, two specific antibodies, a rabbit polyclonal antibody directed to the intracellular domain and a murine monoclonal antibody recognizing an epitope in the extracellular domain, were used. Seventeen cases of bladder cancer were stained by the anti-c-erbB-2 polyclonal antibody, while 20 cases were stained by the monoclonal antibody, with good correlation on both stainings (p less than 0.01). There were four c-erbB-2 positive cases in 26 G1 tumors, four in 15 G2 tumors, and nine in 13 G3 tumors. There were also eight erbB-2 positive cases in nine muscle-invasive tumors, nine of 45 superficial tumors, four of five with lymph node metastasis, and seven of 14 without metastasis, as revealed by staining with the polyclonal antibody. Thus, the c-erbB-2 gene product was more frequently expressed in high grade tumors (p less than 0.01), in high stage tumors (p less than 0.01), and nodal metastatic tumors (N.S. by Chi-square test). Twenty-two of the 54 tumors were stained by an anti-EGF-R monoclonal antibody, 528 IgG. The expression of EGF-R was independent of histological grading, tumor stage, and nodal status, and no correlation was observed between expression of the c-erbB-2 product and EGF-R. The c-erbB-2 product may be applicable as a tumor marker for evaluation of malignant potential, invasiveness, and probably metastatic potential of human bladder cancer.
Antibodies, Monoclonal↗
Quantitative assay of epidermal growth factor receptor in human squamous cell carcinomas of the oral region by an avidin-biotin method.
A quantitative assay method for epidermal growth factor receptors (EGFRs) of human tumor tissues was established, based on enzyme-labeled avidin-biotin (LAB) interaction with anti-human EGFR monoclonal antibody 528IgG. A standard calibration curve for EGFR estimation in human tumor tissues was obtained with A431#8 cells cloned from A431 human epidermoid carcinoma cell line. The coefficient of variance for the standard curve was below 35% in the application to tumor tissues from nude mice implanted with human tumor cell lines. The minimum tissue amount required for the quantitative assay was around 0.1 g (wet weight). Using the LAB method, the correlation between the level of EGFR number and tumor malignancy was examined for 14 human squamous cell carcinomas (SCCs) from the oral region. Seven of the SCCs showed a more than two-fold higher EGFR number compared to normal gingival tissues. Three highly aggressive carcinomas with poor prognosis possessed five to ten times higher levels of EGFR number than normal tissues. The elevated EGFR level in the SCCs seems to correlate to increasing tumor size and the stage of SCCs as clinically classified according to the 1987 UICC TNM system.
Adult↗
Effect of long-term treatment with an angiotensin-converting enzyme inhibitor on the renin-angiotensin system in spontaneously hypertensive rats.
1. To obtain information on regulation of the brain renin-angiotensin system, the effect of long-term administration of angiotensin-converting enzyme (ACE) inhibitor on brain renin and angiotensinogen mRNA was studied. 2. Spirapril (3 mg/kg) was orally administered daily for 8 weeks to spontaneously hypertensive rats (SHR) from 12 weeks after birth. Renin and angiotensinogen mRNA in the brain and kidney were then quantitated by Northern blot analyses with [32P]-labelled rat renin and angiotensinogen cDNA as hybridization probes. Plasma renin activity (PRA), angiotensin II (AII) concentration, plasma ACE activity and brain tissue ACE activity were also measured. 3. Compared with the control group, the Spirapril-treated group had significantly lower blood pressure (P less than 0.01), significantly higher PRA (P less than 0.01), a not significantly different plasma AII concentration, and lower plasma and brain ACE activities (P less than 0.01). Interestingly, the brain renin and angiotensinogen mRNA levels of the two groups were similar, but the renal renin mRNA level was significantly higher in the Spirapril-treated group (P less than 0.01). 4. These results indicate that the mRNA levels of brain renin and angiotensinogen were not affected by chronic ACE inhibition in the circulation and suggest that AII in the brain might not be affected by systemic ACE inhibition.
Actins↗
Pathogenetic role of vascular angiotensin-converting enzyme in the spontaneously hypertensive rat.
1. This study was undertaken to examine the possibility that the level of angiotensin-converting enzyme (ACE) increases in vascular tissue, and that this may participate in the pathogenesis of hypertension in spontaneously hypertensive rat (SHR). 2. In SHR, at the established hypertensive stage, the prolonged antihypertensive effect induced by a single oral dose of spirapril was closely correlated to the long-lasting inhibition of ACE in aortae and mesenteric arteries. In contrast, ACE in plasma, lung, heart and kidney recovered from inhibition faster than in vessels. 3. Prolonged daily oral treatment of SHR with spirapril, initiated at the age of 8 weeks and continued for 8 weeks, prevented the development of hypertension with concomitant decrease in aortic ACE activity. Blood pressure continued to be suppressed after the drug was withdrawn, as did the aortic ACE activity. 4. Spontaneously hypertensive rats developed hypertension with age as well as with the increase in aortic ACE activity which became higher with age than that of Wistar-Kyoto (WKY) normotensive control rats. On the contrary, ACE activity in plasma and lung of SHR was substantially lower than that of WKY at any age from 4 to 20 weeks old. Brain ACE activity of SHR did not differ from that of WKY at any age. Aged SHR showed the lower enzyme activity in the kidney compared with that of age-matched WKY. 5. Our results support the hypothesis that increased vascular ACE may play an essential role in the development and maintenance of hypertension in SHR.
Aging↗
Immobilized enzymes in organic solvents.
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Biotechnology↗
Age-related changes in adrenergic alpha 1, alpha 2, and beta receptors of rat white fat cell membranes: an analysis using [3H]bunazosin as a novel ligand for the alpha 1 adrenoceptor.
Age-related changes in alpha 1-, alpha 2-, and beta-catecholamine receptors on membrane of rat epididymal fat cells were investigated. Both young (6 weeks old, weight about 190 g) and aged (20 weeks old, weight about 490 g) Sprague-Dawley male rats were used. For the alpha 1-adrenoceptor binding experiment, we developed a novel analytical method using the hydrophilic alpha 1-receptor selective antagonist, [3H]bunazosin. The binding of [3H]bunazosin to its binding sites was rapid, reversible, saturable, and stereospecific. Scatchard binding analysis showed a single class of binding site. The sites were characterized as alpha 1-adrenoceptors by inhibition experiments using various agonists and antagonists. The number of maximum binding sites (Bmax) of alpha 1-receptor binding was 37.0 +/- 6.5 (young) versus 24.0 +/- 3.2 (aged) fmol/mg protein (P less than 0.01). [3H]Rauwolscine and [3H]CGP-12177 were used for alpha 2- and beta-receptor binding, respectively. In alpha 2-receptor detection using [3H]rauwolscine as a ligand, Bmax increased markedly from 19.8 +/- 4.9 to 86.2 +/- 19.5 fmol/mg protein (P less than 0.01). In contrast, Bmax for beta-receptor decreased from 69.7 +/- 9.7 to 45.4 +/- 13.9 fmol/mg protein with increasing rat age (P less than 0.05). Kd showed no change in each of the binding experiments between young and aged rats. The cell volume increased from 0.07 +/- 0.02 to 0.15 +/- 0.06 nl. It is implied that anti-lipolytic activity strengthened on the whole mainly with the marked increase of alpha 2-receptor number and decrease of beta-receptor number.(ABSTRACT TRUNCATED AT 250 WORDS)
Adipose Tissue↗
Improvement of glucose and lipid metabolism associated with selective reduction of intra-abdominal visceral fat in premenopausal women with visceral fat obesity.
Visceral fat obesity (VFO) with predominant intra-abdominal fat accumulation has been shown to be more often associated with metabolic disorders than subcutaneous fat obesity (SFO). In the present study, changes in fat distribution and their effects on metabolic complications were investigated in forty premenopausal female obese patients in whom substantial weight reduction was obtained by means of a low calorie diet. Analysis of fat distribution by CT scanning demonstrated that visceral fat decreased to a greater extent than abdominal subcutaneous fat, which was particularly evident in VFO patients. On the other hand, change of fat distribution was small in SFO patients. That is, visceral to subcutaneous abdominal fat ratio (V/S ratio) decreased from 0.62 +/- 0.36 to 0.46 +/- 0.33 in VFO, whereas from 0.23 +/- 0.07 to 0.20 +/- 0.09 in SFO after weight reduction. Although obese patients, especially those with VFO, were frequently associated with glucose intolerance and hyperlipidemia, marked diminution was observed in the elevated levels of plasma glucose area on 75g OGTT, serum total cholesterol and triglyceride after weight reduction. By the examination of interrelationship between the changes in body weight, BMI, total and regional fat volume and changes in glucose and lipid metabolism, we found that the decrease in the V/S ratio and visceral fat volume were more strongly correlated with the improvement in plasma glucose and lipid metabolism compared to the decrease in body weight, BMI, total fat volume and abdominal subcutaneous fat volume. Furthermore, partial correlation analyses demonstrated that the metabolic improvements were associated with changes in visceral abdominal fat after control for changes in total adipose tissue volume.(ABSTRACT TRUNCATED AT 250 WORDS)
Abdomen↗
[Timing of operation based on evaluation of postoperative left ventricular contractility in patients with aortic regurgitation].
To evaluate the effect of aortic valve replacement on left ventricular function in aortic regurgitation, the ratio of end-systolic wall stress to end-systolic volume index (ESS/ESVI) and standard ejection phase indexes of left ventricular function were measured angiographically in 29 patients with isolated, chronic aortic regurgitation before and an average of 26 months after aortic valve replacement. The patients were divided into three groups based on preoperative left ventricular volume at end-systole (ESVI); 12 patients had an ESVI smaller than 100 ml/m2 (group I), 11 had an ESVI of 100 to 200 ml/m2 (group II) and 6 had an ESVI greater than 200 ml/m2 (group III). Postoperatively, end-diastolic volume index and ESVI decreased markedly in all 3 groups and end-systolic stress also decreased. Systolic pump performance assessed as ejection phase indexes improved in all groups with group I and group II showing normal or near-normal ejection fraction, while group III still had a depressed ejection fraction. Left ventricular contractile function as assessed by ESS/ESVI improved significantly in each group postoperatively. After operation, group I patients had normal values. However, both group II and group III still had a subnormal ratio, suggesting a depressed contractility despite normal or near normal systolic pump performance. Surgical correction for aortic regurgitation should be considered before a preoperative ESVI exceeds 100 ml/m2, to preserve postoperative left ventricular contractility.
Adult↗
Analyses of survival rate of unresectable pancreatic adenocarcinoma in aspect of data analyses.
Using Cox's proportional hazard model and Weibull's proportional hazard model and taking into account the covariates involved, estimation of survival time was made on 94 confirmed deceased cases of unresectable pancreatic adenocarcinoma (excluding cases of cystadenocarcinoma) from the data of their admission for confirmation of diagnosis. The following results were obtained: 1) The covariates which were related to the prognosis of unresectable pancreatic adenocarcinoma were presence or absence of metastasis to the liver and lung, type of treatment for obstructive jaundice, and whether in such treatment, chemotherapy, or radiotherapy was conducted. 2) Estimation of the survival time after adjusting these factors showed that the median survival time was 57 days in untreated cases with metastasis, 107 days in untreated cases without metastasis, 284 days in cases with metastasis in which surgical treatment for obstructive jaundice, chemotherapy, and radiotherapy was administered, and 350 days in cases without metastasis in which the same positive treatment was administered. It can therefore be deduced that multidisciplinary treatment is effective in prolonging life.
Adenocarcinoma↗
A case report of 21 years' survival after aortic valve replacement with beta-propiolactone-preserved aortic allograft.
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Aortic Valve↗
A five-year appraisal and hemodynamic evaluation of the Björk-Shiley Monostrut valve.
Two hundred forty-four Björk-Shiley Monostrut valves were implanted in 225 consecutive patients from October 1983 to December 1988. Aortic valve replacement was performed in 90 patients, mitral valve replacement in 118, and double valve replacement in 16 patients. One patient had tricuspid valve replacement. There were 100 female patients and 125 male patients with a mean age of 54 years (range 2 to 71 years). Present data were completely available for all patients. The cumulative follow-up was 541 patient-years with a mean of 2 years, 5 months. The closing date for follow-up was July 1989, and the closing interval was 2 months. The early mortality rate was 3.1%, and the late mortality rate, 3.1%. The 5-year survival rate was 88% +/- 2.0%: 87% +/- 3.0% for aortic valve replacement, 91% +/- 3.3% for mitral valve replacement, and 75% +/- 9.6% for double valve replacement. The actuarial rates of freedom from thromboembolism at 5 years were 93% +/- 3.2% for aortic, 96% +/- 1.4% for mitral, and 94% +/- 6.1% for double valve replacement. There were no instances of structural valve deterioration. Actuarial rate of freedom from valve-related morbidity and mortality was 86% +/- 2.0% at 5 years: 86% +/- 9.5% for aortic, 87% +/- 3.3% for mitral, and 75% +/- 7.3% for double valve replacement. Effective valve areas (average) of 12 mitral and 12 aortic valve prostheses were calculated at rest and during bicycle exercise: 2.4 cm2 at rest and 2.8 cm2 during exercise in 27 mm aortic valves, 2.4 cm2 at rest and 3.0 cm2 during exercise in 25 mm aortic valves, 2.0 cm2 at rest and 2.4 cm2 during exercise in 27 mm mitral valves, and 2.6 cm2 at rest and 2.5 cm2 during exercise in 29 mm mitral valve. On the basis of our follow-up period of 5 years, we have judged the Björk-Shiley Monostrut valve reliable, with a low incidence of valve-related morbidity and with acceptably satisfactory hemodynamic characteristics at rest and during exercise.
Adolescent↗
High sucrose diet increases visceral fat accumulation in VMH-lesioned obese rats.
We have previously reported that metabolic abnormalities in obese subjects are closely related to intraabdominal fat accumulation. In order to clarify the causal relationship between high sucrose intake and intraabdominal visceral fat accumulation, the effects of a high sucrose diet on mesenteric fat weight, fasting plasma glucose (FPG) and triglyceride (TG) levels were investigated in bilateral ventromedial hypothalamic-lesioned obese rats (VMH) and control rats (control). The mesenteric fat weight (g)/abdominal subcutaneous fat weight (g) (M/S ratio), a parameter of visceral fat accumulation, was significantly higher in a high sucrose diet fed group (HSD group) (VMH 1.94 +/- 0.71, control 1.63 +/- 0.28) than in a lab chow fed group (LC group) (VMH 1.30 +/- 0.31, control 1.27 +/- 0.33) (P less than 0.01). In addition, the fat cell volume of mesenteric fat deposits was significantly greater in the HSD group (VMH 1.17 +/- 0.26 nl, control 0.24 +/- 0.10 nl) than in the LC group (VMH 0.74 +/- 0.27 nl, control 0.14 +/- 0.07 nl) (P less than 0.001), although the fat cell number did not differ among any experimental rat groups. FPG and TG levels were higher in the HSD group than in the LC group in VMH-lesioned rats, and a significant correlation was observed between mesenteric fat volume and FPG levels (VMH r = 0.58, P less than 0.05; control r = 0.50, P less than 0.05) as well as between mesenteric fat volume and TG levels (VMH r = 0.49, P less than 0.05; control r = 0.56, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Adipose Tissue↗
Human poly(ADP-ribose) polymerase gene. Cloning of the promoter region.
The promoter region of the poly(ADP-ribose) polymerase gene has been isolated using a Sau3AI genomic library derived from human leukocyte. It lacks typical transcriptional regulatory elements such as TATA and CAAT boxes, but it contains two potential Sp1 binding sites and three putative AP-2 binding elements. The region up to nucleotide position-99 in relation to the predominant transcriptional initiation site exhibits promoter activity as judged by chloramphenicol acetyltransferase assay and the activity is enhanced both by cAMP and by phorbol ester. Northern blot and Western blot analyses have revealed that expression of the polymerase gene is also stimulated by both of these compounds in cultured HeLa cells. Southern blot hybridization of genomic DNA separately digested with various endonucleases gives a discrete single band in each case when the 5'-untranslated region of the polymerase cDNA is used as a probe. These results indicate that poly(ADP-ribose) polymerase is encoded by a unique gene whose expression is regulable by cAMP and by phorbol ester.
Amino Acid Sequence↗