Biomedical subjects

M Abe

Publications and source records attributed to M Abe.

At least 793 records · Page 44Linked to original sources

PubMed1993

Pharmacologic profile of endothelinA/B antagonist, [Thr18, gamma methyl Leu19]endothelin-1.

The pharmacologic profile of [Thr18,gamma methyl Leu19]endothelin-1 (TM ET-1) was investigated in several in vitro and in vivo studies. We found that TM ET-1 inhibited 125I-ET-1 binding in porcine cardiac membrane (ETA receptor) and in bovine brain membrane (ETB receptor), with IC50 values of 0.7 and 0.25 nM, respectively. These values were almost comparable to those for ET-1. TM ET-1 had no effect on intracellular Ca2+ concentration ([Ca]i) in A10 cells mediated by ETA receptors, even at 10(-5) M, or in mouse peritoneal macrophages (MPMs) mediated by ETB receptors, even at 10(-6) M. Increases in [CA]i in A10 cells by ET-1 and in MPMs by ET-3 were completely blocked by pretreatment with 10(-7) M of TM ET-1. In porcine right coronary arteries (PCAs) and in great cardiac veins (PCVs), TM ET-1 caused no contraction at concentrations < or = 10(-6) and 10(-7) M, respectively, although it competitively inhibited ET-1-induced contraction of PCAs and Ala1,3,11,15-ET-1-induced constriction of PCVs with pA2 values of 7.0 and 9.2, respectively. Furthermore, TM ET-1 was more potent than BQ123, an ETA-specific antagonist, in inhibiting the rise in perfusion pressure in a hind-limb preparation in vitro and the increase in blood pressure in rats. These results suggest that TM ET-1 is a potent ETA and ETB antagonist without agonistic effects and can be used in future studies to help clarify the physiological role of ET.

Animals↗

PubMed1993

Osteocyte viability after high-dose irradiation in the rabbit.

The effects of high-dose irradiation on the metabolism of osteocytes were examined with respect to RNA synthesis. A single 50-Gy dose of high-energy electron beam was given to the proximal tibia of rabbits. RNA synthesis by osteocytes was quantified by counting the silver grains on autoradiographs of cultured bone fragments, using 3H-cytidine as a tracer. At four, 12, and 52 weeks after irradiation, RNA synthesis by the irradiated osteocytes was 72, 62, and 79%, respectively, of that by nonirradiated osteocytes. The proportion of labeled osteocytes, conversely, was not reduced at four and 12 weeks, but was significantly reduced at 52 weeks after irradiation. The reduction in the RNA synthesis of osteocytes occurs fairly quickly, whereas reduction in the number of viable osteocytes occurs slowly as a delayed sequela. Histologic examination showed that the partial recovery of RNA synthesis observed at 52 weeks was attributable to the appearance of a fraction of new osteocytes, i.e., subendosteal apposition of new bone to the original, degrading cortex. These observations demonstrate the process of recovery from radiation damage.

Animals↗

PubMed1993

Is left ventricular systolic dysfunction in hypertensive patients with heart failure normalized by long-term antihypertensive therapy?

The critical left ventricular (LV) mass when hypertensive heart failure appears, and whether LV dysfunction in hypertensives with heart failure is normalized by long-term antihypertensive therapy were investigated. LV dimension, LV mass, LV mass index, LV ejection time (LVET) and pre-ejection period (PEP) were measured in 27 normal subjects and 56 essential hypertensives, the latter divided into three groups: group I, without LV hypertrophy; group II, with LV hypertrophy; and group III, with hypertensive heart failure. LV mass and LV mass index were 135.0 +/- 23.8 g and 85.8 +/- 11.7 g/m2, respectively, in normal controls, 133.0 +/- 30.8 g and 82.0 +/- 18.4 g/m2 in group I, 222.3 +/- 38.0 g and 136.1 +/- 19.9 g/m2 in group II, and 422.0 +/- 30.3 g and 235.7 +/- 19.6 g/m2 in group III of essential hypertensives. The upper limits of LV mass and LV mass index in group II (mean + 2SD) were about 300 g and 180 g/m2, respectively. Significant shortening of LVET was observed only in group III, but PEP was prolonged with an increase in LV mass. LV diastolic dimension and PEP were not normalized by long-term antihypertensive therapy (mean: 16 months). These results indicate that the critical LV mass marking the transition from non-failing hypertrophied left ventricle to failing ventricle associated with essential hypertension is about 300 g, or LV mass index of 180 g/m2, and that LV dilatation and depressed myocardial contractility in essential hypertensives with a past history of congestive heart failure were not normalized by chronic antihypertensive therapy.

Adult↗

PubMed1993

[The significance of preoperative chemotherapy for thermopreservation of limbs].

Preoperative chemotherapeutic effects on 42 osteosarcomas treated with CDDP intra-arterial infusion protocol were compared with the effects of treatment of same by local perfusion only, following administration of adriamycin (ADR) or high doses methotrexate and leucovorin (HD-MTX). Thirteen cases were further given local hyperthermic perfusion (LHP) treatment. The preoperative local treatment resulted in a poor response in cases in which the serum ALP failed to fall down the normal range, those with angiographically demonstrated tumor stains remaining, and those with reactive zones remaining as indicated by T2 MR imaging. The ratios of necrotic areas were significantly higher in the LHP group, while those of viable areas were significantly lower in the LHP group compared to other groups. Total tumor cell killing was possible in six of 13 cases in the LHP group. Post-necrotic fibrosis and post-necrotic osteosclerosis were significantly higher in the LPH group. The results suggested that, in selected cases treated with LHP, conservative surgery may well be possible so as to preserve all functional activity.

Adolescent↗

PubMed1993

A rapid radioassay and some properties for leukotriene C4 synthase.

Incubation of glutathione, containing 35S-glutathione (GSH), and leukotriene (LTA4) in the presence of LTC4 synthase produced 35S-LTC4. The LTC4 was ether extracted and detected by ultraviolet absorbance (280 nm) after reverse phase-high performance liquid chromatography (RP-HPLC) separation. The 35S-LTC4 was quantitated by scintillation counting. LTC4 production increased in a dose-dependent manner for GSH concentrations from 10(-8) to 10(-2) M. On the contrary, the 35S detected in the ether phase and the 35S-LTC4 recovered from RP-HPLC decreased inversely with the concentration of unlabeled GSH added but did not with the addition of L-cysteine. This decrease in 35S-LTC4 production versus increased GSH levels results from a direct competition between unlabeled GSH and 35S-GSH reacting with the LTA4. Incubation of GSH (0.5 mM), containing 35S-GSH (0.3 uCi, 10 nM) and LTA4 (10 microM) with LTC4 synthase produced 35S-LTC4 at a linear rate over 5 min. The 35S-LTC4 increased in proportion to the LTC4 synthase added. Therefore, we have demonstrated that LTC4 synthase activity can be monitored by a simple radioassay procedure that measures 35S counts in ether extracts from incubation mixtures. This reliable and rapid assay procedure promises to facilitate characterization and purification of LTC4 synthase, a membrane-bound GSH S-transferase of unique specificity.

Chromatography, High Pressure Liquid↗

PubMed1993

[Breast conservation treatment for breast cancer].

Breast conserving treatment is defined as a combination of conservative surgery for resection of the primary tumor (lumpectomy, segmental mastectomy, or quadrantectomy), mostly with dissection of the axillary nodes, followed by radiation therapy for the eradication of residual microscopic disease in the breast and, in some cases, draining nodal tissues. The goal of this treatment is to provide highly satisfactory cosmetic results, without compromising local tumor control or survival compared with total mastectomy. This review article summarizes the results of prospective randomized trials comparing breast conserving treatment with mastectomy, the NIH consensus conference statement, patient selection, complications, cosmetic outcomes, the present situation of this treatment in Japan and our clinical results using CT simulator for radiotherapy treatment planning.

Breast Neoplasms↗

PubMed1993

Evaluation of experimental liver tumors using fluorine-18-2-fluoro-2-deoxy-D-glucose PET.

Japanese white rabbits transplanted with VX2 liver tumors are considered to be a suitable experimental model for the evaluation of therapeutic modalities. However, there has been no adequate method of assessing the changes of tumor metabolism during treatment. In the present study, 15 rabbits with VX2 liver tumors were examined by PET using 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG). After an intravenous injection of 18F-FDG, serial arterial blood sampling was performed. One hour after tracer injection, small pieces of normal liver tissue and tumor tissue were excised to determine radioactivity. Dynamic PET images were obtained in 11 of the tumor-bearing rabbits, and tumor enzyme activities were determined in six rabbits. Fluorine-18-FDG uptake by the VX2 liver tumors was 3.5 +/- 0.9 times higher than that by the normal liver tissue; so good contrast between tumor and normal liver tissue was achieved on PET scans. The enzyme activity study showed that VX2 tumors had increased levels of hexokinase and pyruvate kinase activity, suggesting an increase of glycolysis. We conclude that transplanted VX2 liver tumors could be appropriately evaluated by 18F-FDG PET.

Animals↗

PubMed1993

[Efficacy and safety of long-term erythropoietin therapy in chronic hemodialysis patients with renal anemia].

In order to examine the efficacy and safety of long-term erythropoietin (rHuEPO) therapy, 103 hemodialysis patients were treated with rHuEPO for their renal anemia and the effects were observed for 1 year. Within 3 or 4 months after starting the rHuEPO therapy, the hematocrit (Ht) value rose up to nearly 30% and the level was maintained thereafter by approximately 4500 IU per week of rHuEPO. Tachyphylaxis did not occur even after 1 year of rHuEPO treatment. Symptoms such as headache, dizziness or palpitation were markedly reduced with the improvement of anemia. Although blood pressure was modestly elevated (systolic by 9 mmHg, p < 0.01 and diastolic by 5 mmHg, p < 0.01 at 6-month-stage), only 1 patient was forced to stop the therapy. Moreover, the blood pressure was successfully controlled to the original level after 11 months. This blood pressure elevation was not related to the increase of Ht level nor the dose of rHuEPO. Serum protein, lipid, electrolytes and liver enzymes did not change during 1 year of rHuEPO therapy. These results indicate that rHuEPO treatment is effective and innocuous as a long-term therapy of renal anemia in hemodialysis patients.

Anemia↗

PubMed1993

Human chromosome 8 (p12-->q22) complements radiosensitivity in the severe combined immune deficiency (SCID) mouse.

The severe combined immune deficiency (SCID) mouse shows two kinds of phenotypic abnormalities, a high radiosensitivity and an abnormal immunoglobulin gene recombination. A genetic study has revealed that a mutation exists in chromosome 16. However, several attempts to isolate the gene responsible for these phenotypes have been unsuccessful. By making use of the characteristics of radiosensitivity, we conducted complementation experiments to identify a human chromosome which contains the responsible gene. Radioresistant cells were selected from the hybrid cells of the SCID mouse and human fibroblasts. Based on this approach, the gene complementing the SCID phenotype was assigned to human chromosome 8 p12-->q22.

Animals↗

PubMed1993

[Measurement and its fluctuation of urinary glucaric acid in newborns].

It is known that urinary excretion of glucaric acid(GA) is an indirect index of hepatic P-450 microenzyme induction. We measured and analyzed urinary excretion of GA in 56 newborns and 26 mothers by a new method for the inhibition of beta-glucuronidase activity and obtained the following results. 1. The concentration of urinary GA was correlated with that of urinary creatinine and total bilirubin in newborns. 2. There were no significant correlations between gestational age, sex, body weight at birth, placental weight and the urinary GA concentration. 3. The urinary excretion of GA in newborns was decreased the in first few days after birth, but a transitional increase was observed on the fifth day after birth. 4. The concentration of urinary GA was correlated with that of direct bilirubin in serum on the fifth day after birth. 5. There was a negative correlation between the urinary GA concentration on the first day after birth and that of direct bilirubin in serum on the fifth day after birth. These results suggested that hepatic P-450 microsomal enzyme was induced by bilirubin in newborns and it was possible to estimate the clinical course of jaundice by measuring the urinary excretion of GA.

Bilirubin↗

PubMed1993

[Full thickness chest wall resection for recurrent breast cancer with reference to prognostic factors].

Full thickness chest wall resection surgery has been carried out in 16 patients with local recurrence after previous mastectomy. Seven of 16 patients had isolated chest wall recurrence, but 9 had mediastinal invasion and/or distant metastasis of carcinoma. Recurrent breast carcinoma involving the bony chest wall was resected, and the chest wall defects were reconstructed with myocutaneous flaps using rectus abdominis or latissimus dorsi, or breast flap. Marlex mesh was utilized under the flap in 10 patients. The 3 year survival probability was 79% and the 5 year one was 57% with mean follow-up period of 43 month. Local recurrence was classified into 3 types according to cancer infiltration; i.e., demarcated, scattered and diffuse types. The patients with demarcated type showed better prognosis than those with diffuse type. Patients who received curative surgery showed better prognosis than those receiving palliative surgery. A disease free interval (DFI) after mastectomy longer than 5 years correlated well with a long survival rate after chest wall resection. Thus, local recurrence presenting demarcated tumor with possible curative surgery as well as a longer DFI after mastectomy is a favorable prognostic factor for full thickness chest wall resection.

Adult↗

PubMed1993

[Two cases of coarctation complex associated with congenital esophageal atresia (Gross type C)].

Two cases of coarctation complex (CoA + VSD + PDA) associated with congenital esophageal atresia (Gross type C) were successfully treated with esophageal and two-staged cardiac surgery. The perioperative management of the two cases is discussed with special reference to circulatory, respiratory and nutritional problems. Case 1; A newborn was diagnosed as esophageal and cardiac anomalies and gastrostomy was performed followed by end to end anastomosis of the esophagus under receiving Prostaglandin E1 infusion. Although subclavian flap angioplasty (SFA) and pulmonary artery banding (PAB) were performed 1 month later, she had recurrent respiratory complications and malnutrition postoperatively due to bronchomalacia and gastroesophageal reflux (GER). Case 2; A newborn was diagnosed as esophageal atresia and underwent corrective surgery of it on the 1st day of life. After esophageal surgery congestive heart failure (CHF) developed progressively and CoA complex was evident by echocardiography 5 days later. SFA and PAB were performed 26th day of life. In spite of the palliative surgery for cardiac lesions, both patients had growth failure because of CHF, respiratory complications and malnutrition. As soon as the circulatory and respiratory condition improved, corrective surgery was performed and resulted in full recovery.

Aortic Coarctation↗

PubMed1993

[A case of Werner syndrome associated with spastic paraparesis and peripheral neuropathy].

A 33-year-old woman, whose parents were consanguineously married, was admitted to our hospital because of progressive difficulty in walking and hoarseness in speech. She had been in good health as a child, at age 16 ulcerations appeared on the skin of feet, and have been recurrent. AT age 22, bilateral cataracts were removed. From the age of 26 years, the deformities in the toes and fingers worsened and she had difficulty in walking. At age 32, hoarseness was noticed. The patient was a diminutive woman and the skin was dry, thin and hyperpigmented. The neurological examination revealed mental retardation, spastic paraparesis and polyneuropathy. Electrophysiological studies revealed a slowing of central and peripheral nerve conduction. Sural nerve biopsy revealed a significantly higher incidence of de- and remyelination and a loss of myelinated fibers. These data suggest that the central and peripheral nervous systems are affected in Werner syndrome.

Adult↗

PubMed1993

[Current status of thermoradiotherapy in cancer therapy].

The current status of thermoradiotherapy for cancer is reviewed. The usefulness of this combined treatment for superficial tumors, in which heating and thermometry are relatively easy to apply, has been clearly demonstrated by many clinical results. With recent technological advancements, the application of thermoradiotherapy to deep-seated tumors is increasing, and encouraging results have been reported for various tumors including brain tumors, carcinomas of the breast, lung, esophagus, liver, rectum, urinary bladder, and soft tissue tumors. Thermoradiotherapy seems a very promising treatment modality for various refractory malignancies.

Brain Neoplasms↗

PubMed1992

Induction of c-fos gene expression by exposure to a static magnetic field in HeLaS3 cells.

Effects of a static magnetic field on cell growth and c-fos oncogene expression were investigated. HeLaS3 cells exposed to the magnetic field of 0.18-0.2 T for 1-6 days were not affected in the cell growth. Exposure to the magnetic field did not enhance the effects of X-rays or heat treatment which caused the transient cell growth delay. c-fos mRNA in the HeLaS3 cells was undetectable in untreated cells, but the expression was induced in cells by the magnetic field exposure for 2-24 h. The amounts of the mRNA expression changed time dependently with a peak at a 6-h exposure. c-fos was expressed following the heat treatment at 45 degrees C for 10 and 15 min, and the expression was further enhanced by the treatment of cells with heating followed by 4 h of the magnetic field exposure. Exposure of the cells to a static magnetic field may affect some cellular metabolic events leading to the c-fos gene expression.

Cell Division↗

PubMed1992

Corn kernel cysteine proteinase inhibitor as a novel cystatin superfamily member of plant origin. Molecular cloning and expression studies.

A full-length cDNA clone for a cysteine proteinase inhibitor (cystatin) was isolated from a lambda gt10 cDNA library of immature corn kernels by screening with a mixture of cDNA inserts for oryzacystatins I and II. The cDNA clone spans 960 base pairs, encoding a 135-amino-acid protein containing a signal peptide fragment. The protein, named corn cystatin I, is considered to be a member of the cystatin superfamily, since it contains the commonly conserved Gln-Val-Val-Ala-Gly region that exists in most known cystatins as a probable binding site and is significantly similar to other cystatins in its overall amino acid sequence. Corn cystatin I expressed in Escherichia coli showed a strong papain-inhibitory activity. Northern blot analysis showed that the amount of mRNA for corn cystatin I reaches a maximum 2 weeks after flowering and then decreases gradually.

Amino Acid Sequence↗

PubMed1992

A rat model of human T lymphocyte virus type I (HTLV-I) infection. 1. Humoral antibody response, provirus integration, and HTLV-I-associated myelopathy/tropical spastic paraparesis-like myelopathy in seronegative HTLV-I carrier rats.

Human T lymphocyte virus type I (HTLV-I) can be transmitted into several inbred strains of newborn and adult rats by inoculating newly established HTLV-I-immortalized rat T cell lines or the human T cell line MT-2. The transmission efficiency exceeds 80%, regardless of strain differences or the age at transmission. The production of anti-HTLV-I antibodies significantly differs among the strains and depends on the age at the time of transmission. Rats neonatally inoculated with HTLV-I-positive rat or human cells generally become seronegative HTLV-I carriers throughout their lives, whereas adult rats inoculated with HTLV-I-positive cells at 16 wk of age become seropositive HTLV-I carriers. The HTLV-I provirus genome is present in almost all organs, regardless of whether the carriers are seronegative or seropositive. According to antibody titers to HTLV-I, there are three groups of inbred rat strains: ACI, F344, and SDJ (high responders); WKA, BUF, and LEJ (intermediate responders); and LEW (low responder). Three of three 16-mo-old seronegative HTLV-I carrier rats of the WKA strain developed spastic paraparesis of the hind legs. Neuropathological examinations revealed that the lesions were confined primarily to the lateral and anterior funiculi of the spinal cord. Both myelin and axons were extensively damaged in a symmetrical fashion, and infiltration with massive foamy macrophages was evident. The most severe lesions were at levels of the thoracic cord and continued from the cervical to the lumbar area. These histopathological features as well as clinical symptoms largely parallel findings in humans with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). These HTLV-I carrier rats, in particular the WKA rats described above, can serve as a useful animal model for investigating virus-host interactions in the etiopathogenesis of HTLV-I-related immunological diseases, particularly HAM/TSP.

Aging↗

PubMed1992

[Fluid-fluid levels in bone and soft tissue tumors demonstrated by MR imaging].

Fluid-fluid levels in bone tumors have been described in aneurysmal bone cysts and other cystic tumors of bones and soft tissue tumors. We experienced three bone tumors (simple bone cyst, bone metastasis, and osteosarcoma) and three soft tissue tumors (fibrosarcoma, two cases of cavernous hemangioma) that showed fluid-fluid levels on MR, and investigated their cause. Causes included blood in the cystic spaces, hemorrhage in the tumor, the telangiectatic component of the osteosarcoma, and the cavernous component of the hemangioma. No specific diagnosis could be made based on the finding of fluid-fluid levels. We conclude that fluid-fluid levels on MR are rather nonspecific findings in bone and soft tissue tumors and that the diagnosis should be made on the basis of other radiological and clinical findings.

Adult↗