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Biomedical subjects

T Umeda

Publications and source records attributed to T Umeda.

At least 163 records · Page 9Linked to original sources
PubMed1993

Endogenous erythropoietin and salt sensitivity of blood pressure in patients with essential hypertension.

To investigate a possible involvement of endogenous erythropoietin (EPO) in the salt sensitivity of blood pressure in essential hypertensive (EHT) patients, plasma EPO concentrations were measured during different salt intakes in 14 patients with EHT. All patients were given low salt (34 mmol NaCl/day) and high salt (342 mmol NaCl/day) diet of 7 days each. The plasma EPO concentrations were significantly higher on the high salt diet than those of low salt diet (23.5 +/- 1.9 v 18.7 +/- 1.8 mIU/ml, mean +/- SD, P < .05). The percentage change of plasma EPO concentration with salt loading correlated positively with hematocrit (Ht) at high salt diet (r = -0.62, P < .02) and tended to be correlated with plasma hemoglobin at high salt diet (r = 0.52, P < .10). These results suggest that the secretion of EPO is increased in response to hemodilution caused by the salt loading and the increased EPO concentration in plasma which may contribute to the increase in blood pressure through an expansion of total blood volume due to an enhanced red cell generation in combination with salt and water retentions.

Adult↗
PubMed1993

The usefulness of the captopril test as a simultaneous screening for primary aldosteronism and renovascular hypertension.

The usefulness of the captopril test as a simultaneous screening method for primary aldosteronism (PA) and renovascular hypertension (RVH) was evaluated in 111 patients with essential hypertension, and in 79 patients with secondary hypertension, which included 16 patients with PA and 18 with RVH. Plasma renin activity (PRA, ng/mL/h) and plasma aldosterone concentration (PAC, ng/dL) were determined before and 90 min after administration of 50 mg of captopril in the supine position on a normal NaCl diet. A cutoff point or a discriminant function in the screening was determined by discriminant analysis. A quadratic discriminant function of PRA and PAC after the captopril test identified patients with PA with a false negative rate of 6.3% (1/16), and a false positive rate of 0.6% (1/174) which was significantly lower than that of 3.4% at the basal state (P < .05). In the screening for RVH, the criterion of a postcaptopril PRA of greater than 10.6 ng/mL/h had a false negative rate of 5.6% (1/18) and a false positive rate of 15.1% (26/172). This false positive rate was also significantly lower than that using a criterion for precaptopril PRA of 2.21 ng/mL/h (P < .05). Accordingly, the captopril test was a useful method in the simultaneous screening for PA and RVH, and it may be particularly applicable in specialized hypertension clinics.

Adult↗
PubMed1993

Effect of sevoflurane on hypoxic pulmonary vasoconstriction in the perfused rabbit lung.

BACKGROUND: In vitro studies have shown that isoflurane, enflurane, and halothane inhibit the hypoxic pulmonary vasoconstriction (HPV) with essentially the same potency. The aim of this study is to compare the effects of sevoflurane and isoflurane on HPV in constant-flow perfused rabbit lungs. METHODS: Constant-flow perfused lungs from Japanese white rabbits were tested. The lungs were divided into three groups: isoflurane alone (n = 6), sevoflurane alone (n = 6), and sevoflurane with ibuprofen pretreatment (n = 6). Baseline HPV responses were measured as the pulmonary arterial pressure increased after changing inspired oxygen concentration from 95% for 15 min to 3% (with 5% CO2) for 5 min without anesthetic administration. Next, three different concentrations of anesthetics were added to the inspired gas for 15 min in random order. The HPV response in the presence of anesthetic was expressed as a percentage of the pressor response in the absence of anesthetics, and dose-response relationships were calculated using the nonlinear least-squares method. RESULTS: Isoflurane and sevoflurane both depressed the HPV response in a dose-related manner. The half-inhibition values (ED50) of HPV with isoflurane and sevoflurane were 0.85 +/- 0.22 MAC and 1.00 +/- 0.12 MAC (mean +/- SD), respectively, and were not statistically different. Ibuprofen pretreatment did not alter ED50 and slope of dose-response curve, although the absolute value of pressor response in the sevoflurane group with ibuprofen pretreatment was greater than that in the sevoflurane alone group at every concentration of sevoflurane. CONCLUSIONS: Sevoflurane inhibits the HPV response in a dose-related manner, and its potency is similar to that of isoflurane in vitro. Cyclooxygenase products do not mediate the inhibition of HPV by sevoflurane.

Anesthetics↗
PubMed1993

Promotion of metastases by tumor necrosis factor in rats bearing Dunning R3327 MAT-LyLu prostatic cancer.

We examined the effects of recombinant human tumor necrosis factor (rTNF) on highly metastatic rat prostatic cancer, Dunning R3327 MAT-LyLu, in vivo. It seemed that the inhibition of tumor growth needed more than 5 x 10(5) units of rTNF and this dose was near the lethal dose. Concerning the effect of rTNF on metastasis, we found that the metastasis to lung was promoted by 1 x 10(5) units of rTNF and the promotion of metastasis was restricted by indomethacin. Although MAT-LyLu cells were producing a significant amount of prostaglandin E2, rTNF did not enhance the production. We therefore consider that the promotion of metastasis was not mediated by prostaglandin E2 from MAT-LyLu cells but was mediated by other very complicated conditions. Further studies are necessary to resolve the mechanisms.

Adenocarcinoma↗
PubMed1993

[Expression of the blood group related antigens (Lewis(a), Lewis(b), Lewis(x), Lewis(y), and other gastroenterological tissue related antigens(CEA, APF, and NSE) in poorly differentiated adenocarcinoma of gastric cancer with medullary growth pattern].

To clarify the clinico-pathological characteristic of poorly differentiated adenocarcinoma of gastric cancer with medullary growth pattern, the immunohistochemical study was performed using antibodies against blood group related antigens (Lewis(a), Lewis(b), Lewis(x), Lewis(y)) and gastrointestinal tissue related antigens (CEA, AFP and NSE). The following results were obtained. 1. Foveolar epithelium of normal gastric mucosa has type 1 blood group associated antigen (Lewis(a), Lewis(b)) and deep gland has type 2 antigen (Lewis(x), Lewis(y)) respectively, as the differentiation antigens. 2. Expression of Lewis(a) and Lewis(b) are more often observed in poorly differentiated adenocarcinoma with medullary and scirrhous growth pattern than in well and moderately differentiated adenocarcinoma. Poorly differentiated adenocarcinomas postulated to have closer relation with normal gastric deep gland in terms of antigen expression. 3. Poorly differentiated adenocarcinoma with medullary growth pattern is characterized as more differentiated type cancer than scirrhous type with respect to expression of blood group related antigen. 4. Poorly differentiated adenocarcinoma with medullary growth pattern may be divided into 3 subgroups by each antigen expression of CEA, NSE, and AFP.

Adenocarcinoma↗
PubMed1993

Two forms of acidic arginine amidases in human kidney.

Two forms of acidic arginine amidases were separated from human kidney extract using the techniques of basic ion exchange adsorption and elution as well as lima bean trypsin inhibitor (LBTI) and aprotinin affinity adsorptions and elutions. The enzymes were tentatively named acidic human renal arginine amidase-L (AHRAA-L, with affinity to an LBTI column) and -A (AHRAA-A, with affinity to an aprotinin column). Both enzymes showed a similar molecular mass of approximately 3.0 x 10(4) daltons, differing from that of human renal kallikrein (HRK, molecular mass of 4.8 x 10(4) daltons). The specific activity of AHRAA-L and -A were 106 and 680 nmol/min/A280 of Val-Leu-Arg-pNA amidolysis, respectively, and they were strongly inhibited by LBTI and human urinary trypsin inhibitor (UTI), while ethylenglycol-bis(beta-amino ethylether)-N,N,N',N'-tetraacetic acid (EGTA) showed a weak or no effect on both enzymes.

Esterases↗
PubMed1993

Pharmacological studies on a new dihydrothienopyridine calcium antagonist. 3rd communication: antihypertensive effects of S-(+)-methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2, 3-b] pyridine-5-carboxylate in hypertensive rats and dogs.

Hypotensive and antihypertensive effects of S-312-d (S-(+)-methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2, 3- b]pyridine-5-carboxylate, CAS 120056-57-7) in Wistar Kyoto rat (WKY), spontaneously hypertensive rat (SHR), stroke-prone SHR (SHRSP), and DOCA-salt hypertensive rat (DOCA-HR) were compared with those of other representative calcium antagonists. The minimal effective hypotensive dose of S-312-d in WKY was 3 mg/kg p.o. and those in SHR, SHRSP, and DOCA-HR were 1 mg/kg p.o. in gum arabic suspension. The minimal antihypertensive dose of S-312-d in polyethylene glycol solution was 0.3 mg/kg p.o. in SHRSP. The antihypertensive effects of S-312-d was the most potent and long-lasting compared with the calcium antagonists, nifedipine, nicardipine, nimodipine, nilvadipine, and flunarizine. In conscious two-kidney Goldblatt-type hypertensive dogs, a significant antihypertensive effect and concomitant increases of heart rate with S-312-d at 1 mg/kg lasted for 4 to 6 h after oral administration. Determination of the plasma concentration of S-312-d by HPLC showed that more than 4.3 ng/ml of S-312-d is required for a significant antihypertensive effect. Subcutaneous administration of atenolol at 20 mg/kg 30 min before S-312-d significantly inhibited the tachycardia with S-312-d at 1 mg/kg p.o. but not its antihypertensive effect. S-312-d is considered useful for the treatment of essential hypertension and related organ disorders.

Animals↗
PubMed1993

[Chemotherapy for soft tissue sarcoma--current concepts and review].

The role of chemotherapy for soft tissue sarcoma with the exception of rhabdomyosarcoma remains controversial. Several randomized trials have suggested only doxorubicin (ADR) and ifosfamide produced a single-agent response rate above 20% in advanced sarcoma. As a combination chemotherapy, the doxorubicin-based combination, ADR + DTIC (ADIC) and CYVADIC, showed a higher response rate. Ifosfamide in addition to doxorubicin (Ifos + ADR or ADIC) appeared to have major activity with a higher complication rate. The role and value of adjuvant chemotherapy have not yet been established. Most randomized studies have suggested that no survival benefit was observed in the chemotherapy group relative to the control group. Further basic and clinical investigation is necessary to obtain a better prognosis in high-grade malignant soft tissue sarcoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

[A case report of condyloma acuminatum of urethral meatus in a boy].

A 4-year-old boy was referred for treatment of papillary tumor at the urethral meatus. He was well until December 1990, when his mother noticed a tumor at the urethral meatus. The tumor was resected elsewhere. However, a similar tumor was noted again at the urethral meatus in May, 1991. The patient was admitted on September 16, 1991. Retraction of the phimotic foreskin revealed a well-demarcated papillary mass, approximately 2 x 2 mm in diameter, at the urethral meatus. There were no tumors on foreskin or glans. Under general anesthesia endoscopy was performed to locate other tumors at the urethra and bladder. No tumors were found elsewhere. Then the meatal tumor was resected surgically. Pathology was condyloma acuminatum. There was no recurrence one year after surgery. We also reviewed 24 boys with condyloma acuminatum, including 13 boys with a solitary condyloma at the urethral meatus, reported in Japan.

Child, Preschool↗
PubMed1993

Establishment of a cell line from a human giant cell tumor of bone.

A cell line (CG-1) was established from a specimen of a 21-year-old woman with giant cell tumor of bone. Inverted-phase microscopic analysis showed that the cultured cells were spindle-shaped in appearance. Multinucleated giant cells and macrophagelike round cells characterizing the histology of giant cell tumor of bone were not found. It is believed that the spindle-shaped cells were the neoplastic element of this tumor, because they were cultured more than 40 passages over the course of one year and subsequent cytogenetic analysis with a G-band technique showed constant loss of chromosomes 14 and 19. The cell line was found to produce several cytokines: M-CSF, IFN-gamma and TNF-alpha, as demonstrated by Western blotting analysis. These cytokines are known to show chemotactic, differentiation-inducing, and activating effects on macrophages. Because it has been recently reported in the literature that there are many infiltrated macrophages in giant cell tumor of bone, and because multinucleated giant cells are formed by fusion of macrophages, the newly established cell line may prove a useful system in studying the nature of giant cell tumor of bone.

Adult↗
PubMed1993

[Toxic effects of ifosfamide in the treatment of bone and soft tissue sarcomas].

A total of 64 courses of ifosfamide (IFM) treatments for sarcoma patients were evaluated for toxic effects. A dose of 100 ml of 1/2 diluted Maalox by normal saline was instilled into urinary bladder with clump of catheter for 15 min for uroprotection instead of Mesna that was not available in Japan at that time. Forty-six courses of ifosfamide treatment in 12-16 g/m2 doses with daily Maalox instillation resulted only one hemorrhagic cystitis, while 18 courses at a dose of 6-10 g/m2 of IFM without Maalox eventuated in 5 cases of hemorrhagic cystitis. Forty-six courses of ifosfamide treatment at a dose of 12-16 g/m2 (mean dose of 14.4 g/m2) for 5 to 6 day continuous infusion were evaluated also for myelosuppression, nephrotoxicity, neurotoxicity, and other toxicities. Myelosuppression was acceptable, although the absolute neutrophil count of the 80% course was below 500. No patient showed neurotoxicity characterized by confusion or somnolence. No course resulted in abnormal serum creatinine elevation, although two of 46 courses caused an abnormal decrease of creatinine clearance. One patient had arrhythmia that required medical treatment after 5 courses of IFM treatment.

Administration, Intravesical↗
PubMed1992

[Image processing of early gastric cancer cases].

Computer image processing was used to enhance gastric lesions in order to improve the detection of stomach cancer. Digitization was performed in 25 cases of early gastric cancer that had been confirmed surgically and pathologically. The image processing consisted of grey scale transformation, edge enhancement (Sobel operator), and high-pass filtering (unsharp masking). Gery scale transformation improved image quality for the detection of gastric lesions. The Sobel operator enhanced linear and curved margins, and consequently, suppressed the rest. High-pass filtering with unsharp masking was superior to visualization of the texture pattern on the mucosa. Eight of 10 small lesions (less than 2.0 cm) were successfully demonstrated. However, the detection of two lesions in the antrum, was difficult even with the aid of image enhancement. In the other 15 lesions (more than 2.0 cm), the tumor surface pattern and margin between the tumor and non-pathological mucosa were clearly visualized. Image processing was considered to contribute to the detection of small early gastric cancer lesions by enhancing the pathological lesions.

Adult↗
PubMed1992

Oral diagnostic reporting and synchronized image filing using magneto-optical disks.

An experimental radiologic reporting system has been developed and tested. The rewritable and compact magneto-optical disk (MOD) is applied to storing medical images with oral diagnostic reports of these radiologic images. The disk is 5.25 inches in diameter, has 600 MB memory capacity, is erasable, light and compact. Advantages are simultaneous recording of radiologic images and their oral reports by radiologists, and application to circulation of media inside the hospital as well as to filing of medical images. The MOD has a multimedia function of communication and filing. When medical images are taken and stored, oral interpretation by radiologists can be simultaneously added. Physicians can get information of the images and their reports by oral speech at the same time in front of computer workstation. Furthermore, integration of a voice recognition capability is now being undertaken.

Image Processing, Computer-Assisted↗
PubMed1992

Ingrown toenails: an evaluation of elevating the nail bed-periosteal flap.

Many procedures to correct ingrown toenails are available; however, they cannot avoid recurrence and nail deformities. We have performed a procedure which corrects ingrown toenail without reducing the width of the nail plate by elevating the nail bed-periosteal flap. Sixty patients were observed for longer than six months and exhibited excellent results. Only two cases of incurvated nails (2) required re-operation.

Humans↗
PubMed1992

Calcitonin release from medullary thyroid carcinoma by thyrotropin-releasing hormone: comparison with calcium injection.

The effects of thyrotropin-releasing hormone on the release of calcitonin were investigated in 15 normal subjects and 12 patients with medullary thyroid carcinoma. The present study also compared the effect of TRH stimulation with calcium infusion test on calcitonin release in patients with medullary thyroid carcinoma. In normal subjects, calcitonin increased from a basal value of 7.5 +/- 2.5 pmol/l to a peak value of 9.4 +/- 3.0 pmol/l (p less than 0.01) after iv injection of synthetic TRH (500 micrograms). Basal calcitonin values in patients with medullary thyroid carcinoma were high (1216 +/- 2230 pmol/l, p less than 0.05), and TRH induced a further increase in calcitonin to 1842 +/- 3149 pmol/l in all the patients (p less than 0.05). They had a peak value of 7891 +/- 13,528 pmol/l after the calcium infusion, which was significantly higher than the basal value of 1463 +/- 2630 pmol/l (p less than 0.05). All medullary thyroid carcinoma patients displayed a marked calcitonin increase after TRH and calcium stimulation. Although the increase in serum calcitonin after TRH injection was lower than that after calcium injection (1.6-fold vs 5.4-fold, p less than 0.05), there was no significant difference in mean peak calcitonin value following TRH and calcium injection in patients with medullary thyroid carcinoma. These results indicated that TRH could stimulate calcitonin release from the thyroid C-cells in both normal subjects and patients with medullary thyroid carcinoma.

Adult↗
PubMed1992

The least number of phosphate groups for crosslinking of casein by colloidal calcium phosphate.

Artificial casein micelles were formed with whole human casein at 20 mM calcium, 17 mM phosphate, and 10 mM citrate. The casein micelles disaggregated by 6 M urea were separated by high performance gel chromatography on a TSK-GEL G4000SW column into crosslinked and monomeric fractions. When the crosslinked casein fraction was analyzed by high performance ionexchange chromatography on a TSK-GEL DEAE-5PW column, a small peak, representing the 3-P component of human beta-casein, and distinct peaks of the 4-P and 5-P components were found. Artificial casein micelles were formed from mixtures of each purified component of human beta-casein and bovine kappa-casein, disaggregated by urea, and separated on a TSK-GEL G4000SW column. The casein aggregates crosslinked by colloidal calcium phosphate were formed in artificial casein micelles of the 3-P and 4-P components. In contrast, no crosslinkage was formed in artificial micelles of the 1-P and 2-P components. The results indicate that at least three phosphate groups are needed for crosslinking of casein by colloidal calcium phosphate.

Animals↗
PubMed1992

[Concentration of 5-fluorouracil in the blood and tissues of gastric and colo-rectal cancer patients after oral administration of UFT].

UFT is given to the patients with digestive cancer from the time before operation to prevent intra- and post-operative cancer dissemination and metastases. UFT (400 mg/day in terms of tegafur) was given preoperatively for 1-6 days in 6 patients with gastric cancer and 13 with colorectal cancer. The interval between the last administration and the beginning of the operation was 3.9 +/- 1.5 hours (mean +/- SD). The concentrations of tegafur, 5-FU, and uracil in the blood collected at the time of tumor resection were 9.68, 0.017, and 0.08 microgram/ml, respectively. In the patients with gastric cancer 5-FU concentration was 5.5 times higher in the normal mucosa, 3.3 times in lymph nodes, and 10.7 times in the tumor tissues than in the blood. In colorectal cancer patients, also, the 5-FU concentration was 5.6, 8.3 and 20.8 times higher in the normal mucosa, lymph nodes, and the tumor tissue, respectively, than in the blood. The 5-FU concentration in gastric cancer and colorectal cancer tissues decreased with time after administration of UFT but remained above the effective concentration 1.5-7 hours after administration of 200 mg. The tissue concentrations of FT-207, uracil, and 5-FU were correlated with each other.

Administration, Oral↗