Biomedical subjects

K Kurisu

Publications and source records attributed to K Kurisu.

At least 253 records · Page 14Linked to original sources

PubMed1991

[Basic and clinical studies of total body irradiation for bone marrow transplantation].

Basic and clinical studies of total body irradiation (TBI) with respect to the dose distribution are described. TBI was performed with 10 MV X-rays at the Department of Radiology of Hyogo College of Medicine Hospital. Two opposed bilateral fields were used, the source-axis distance was 400 cm, and the dose rate was 10 cGy/min. At 55 cm from the rear concrete wall, the back-scattered radiation from the wall was 0.91% of the radiation dose. The beam flatness was +/- 2.9% within 130 cm of the diagonal by using a beam flattening filter improved. The surface dose was 93.5% of the peak dose by the acrylic bolus (1.5 cm thickness) placed on the source side 45 cm from the center of the body axis. We devised compensating filters using lead plates to improve dose distribution of the head, neck and thorax. The effectiveness of the compensating filters in producing a homogeneous dose distribution was checked by the thermoluminescent dosimeters (TLDs) in a Rando phantom. The average dose distribution to each site when the compensators used was 94% for the head, 104% for the neck, and 99% for the thorax when the scheduled dose was taken as 100%. TBI was performed 4 to 1 days before bone marrow transplantation, and 10 Gy was given in equal daily fractions of 2.5 Gy over 4 days. During TBI, the patients were placed in the supine position with the knees bent. The body surface dose was measured with pairs of TLDs at the head, neck, thorax, and pelvis in 32 patients. At the pelvis, the dose was measured simultaneously with an ionization chamber. The average doses were 91% for the head, 95% for the neck, 93% for the thorax, and 106% for the pelvis.

Bone Marrow Transplantation↗

PubMed1991

Immunohistochemical demonstration of amelogenin penetration toward the dental pulp in the early stages of ameloblast development in rat molar tooth germs.

In order to examine the synthesis and secretion of enamel protein by ameloblasts in their early stages of development, immunohistochemical localization was carried out at light and electron microscopic levels using a monoclonal antibody produced in a preliminary experiment. Materials used were tooth germs of mandibular first molars of rats at 0-5 days after birth. Immunoblot analysis after two-dimensional electrophoresis revealed that antigen molecules recognized by the monoclonal antibody were amelogenins of 26-28 kDa (pI, 6.6-7.0). An immunohistochemical examination using this monoclonal antibody demonstrated that the presecretory ameloblasts in their early stages of differentiation both synthesized amelogenin and secreted through a classical merocrine secretory pathway. In some presecretory ameloblasts as well as ameloblasts we observed the distended cisternae of rough endoplasmic reticulum (rER) which demonstrated heterogenous immunolabelling. The immunolabellings were also detected in the predentin as well as the intercellular spaces of odontoblasts and dental pulp cells which indicated penetration of amelogenin from the presecretory ameloblast layer to the dental pulp. The presence of coated pits at the plasma membrane of odontoblasts in close proximity to enamel protein along with the immunolabelling of lysosomes of the odontoblasts suggests the phagocytosis of the enamel protein into the odontoblasts. These observations suggest the possibility that the penetration of enamel protein toward the dental pulp and odontoblasts plays a role in the interaction between ameloblasts and odontoblasts.

Ameloblasts↗

PubMed1991

Vasospasm after traumatic subarachnoid haemorrhage: transcranial Doppler evaluation. Case report.

A case of vasospasm after traumatic subarachnoid haemorrhage (SAH) is reported here. Transcranial Doppler Sonography (TCD) was used to evaluate mean flow velocity (MFV) changes of the basal cerebral arteries related to vasospasm. Acceleration of MFV of the right middle cerebral artery (MCA) indicating vasospasm was first noted on TCD evaluation, and then proved by carotid angiography (CAG). Evaluation of all TCD results revealed that the process of relaxation or normalization of the spastic artery started from the proximal side of the basal intracranial artery and gradually moving to the distal side. This interesting phenomenon could be a common process found in vasospasm cases.

Blood Flow Velocity↗

PubMed1991

High-dose-rate intraluminal brachytherapy for esophageal cancer: 10 years experience in Hyogo College of Medicine.

From May 1980 through December 1989, 148 patients with thoracic esophageal cancer were treated with high-dose-rate intraluminal brachytherapy (HDRIBT) following external radiotherapy (ERT). The standard treatment protocol was 60 Gy/6 weeks of ERT and 12 Gy/1 week of HDRIBT. The patients were divided into two groups according to disease stage. Sixty-six patients had limited disease (LD), and 82 patients had extensive disease (ED). The 2-year survival rate was 37% in LD group, and 7% in ED group. The 5-year survival rate of LD group was 18%. The 1- and 2-year actuarial local control rate was 66% and 64% in LD group, and 49% and 45% in ED group, respectively. In the total patients, ulceration, stricture, and fistula were found in 42 (28%), 15 (10%) and 6 (4%) patients, respectively; however, major complication defined as one resulting in a second hospitalization or requiring surgical intervention was 3 of the 42 patients with ulceration, 1 of the 15 patients with stricture, and all of the six patients with fistula. As to cause of death, local failure, local failure with distant metastasis, distant metastasis, intercurrent disease, and unknown reason was 14, 6, 15, 16 and 0 in LD group, and 13, 24, 30, 9 and 1 in ED group, respectively. The technique and method of combined treatment are described in detail.

Brachytherapy↗

PubMed1991

High-dose-rate intraluminal brachytherapy for bile duct carcinoma after surgery.

Five patients with recurrent or residual bile duct carcinoma after surgery were treated with high-dose-rate intraluminal brachytherapy (HDRIBT) using a remote afterloader. External radiotherapy was also given in three cases. HDRIBT is considered to be an effective mode of radiotherapy for residual or recurrent bile duct tumors.

Bile Duct Neoplasms↗

PubMed1991

Radiotherapy for carcinoma of the esophagus in patients aged eighty or older.

Between 1980 and 1988, 206 patients with esophageal cancer were treated initially with radiotherapy. The patients were classified into three groups according to age. Ninety-four patients aged 43-69 years comprised Group A, 83 patients aged 70-79 years comprised Group B, and 29 patients aged 80-86 years comprised Group C. There were no statistically significant differences in background factors between Groups A, B, and C, except for the sex ratio. The male:female ratio was 7.5:1 in Group A, 3.9:1 in Group B, and 1.9:1 in Group C, with the difference between Groups A and C being statistically significant (p less than 0.05). High-dose-rate intracavitary irradiation (HDRII) with or without external irradiation (EI) was performed in 64%, 69%, and 83% of the patients from Groups A, B, and C, respectively. Patients in Groups A, B, and C achieved CR in 23%, 24%, and 34% of cases following radiotherapy. Two- and 5-year survival rates were 16.7% and 6.7% in Group A, 17.2% and 6.0% in Group B, and 27.1% and 20.3% in Group C. No significant differences were found in the patterns of failure and in the radiation-induced injuries between the three groups. Our data suggested that radiotherapy was the treatment of first choice for patients 80 years old and older.

Adult↗

PubMed1991

High-dose-rate intraluminal brachytherapy (HDRIBT) for esophageal cancer.

High-dose-rate intraluminal brachytherapy (HDRIBT) for patients with esophageal cancer has been performed with and without external radiotherapy (ERT) in our department since May 1980. From May 1980 through December 1986, 92 patients with esophageal squamous cell carcinoma were treated with HDRIBT following ERT. These patients were divided into a limited disease (LD) group and an extensive disease (ED) group. Complete response and partial response rates after treatment were 48% and 38% in the LD group, and 9% and 65% in the ED group, respectively. The median survival time and 2-year survival rate was 13 months and 39% in the LD group, and 8.5 months and 7% in the ED group, respectively. The 5-year survival was 17% in the LD group. HDRIBT without ERT was used to treat six patients with small, superficial esophageal squamous cell carcinoma from August 1987 through July 1988. No patients were candidates for surgery because of coexisting medical problems. Each patient received 6 Gy per treatment, twice weekly with a total of 24 Gy; five of the six patients were treated on an outpatient basis. The tumor had disappeared completely in all six patients at the time of first follow-up endoscopic study less than 1 month after treatment, and no local recurrence had occurred after 11 to 22 months in five of the six patients. Five of the six patients were alive after 11 to 22 months, and one died with mediastinal metastasis at 15 months.

Aged↗

PubMed1991

Distribution of type I and type III collagen in the developing periodontal ligament of mice.

In order to localize type I and type III collagen in developing periodontal ligament, immunofluorescent and immunoelectron microscopic examinations were undertaken. The materials used were the maxillary molars of CF1 mice, 13 days to 6 months old. The antibodies used were monospecific polyclonal antibodies against type I or type III collagen raised in rabbits or guinea pigs, respectively. Single- and double-staining methods were employed in immunofluorescent as well as immunoelectron microscopic examinations. In immunofluorescent examinations, during the development of the periodontal ligament, periodontal fibers showed intense and homogenous staining for both type I and type III collagen; while Sharpey's fibers in the alveolar bone showed a heterogenous staining in cross and longitudinal sections for both types of collagen. In immunoelectron microscopic examinations, fibrils of periodontal fibers showed positive staining for type I and type III collagen simultaneously and had characteristic cross-banding and had a large diameter (ranging 40 approximately 80 nm) which remained constant during development. Sharpey's fibers in the alveolar bone or in the cementum showed the same staining pattern as the periodontal fibers, except for an afibrillar area which showed negative staining for both type I and type III collagen. The results obtained suggest that periodontal fibers and Sharpey's fibers consist of cofibrils of at least type I and type III collagen.

Aging↗

PubMed1991

Effects of glibenclamide and nicorandil on cardiac function during ischemia and reperfusion in isolated perfused rat hearts.

We examined influences of a blocker (glibenclamide) and an opener (nicorandil) of the ATP-sensitive potassium (KATP) channel on extracellular K concentration [( K+]e), as well as the myocardial function and metabolites during global ischemia and reperfusion in Langendorff-perfused rat heart preparation. In control hearts, [K+]e began to rise 20 s after the onset of ischemia up to an initial peak (8.3 +/- 0.3 mM) at 2.5 +/- 0.7 min, then fell to 6.0 +/- 0.8 mM after 8.2 +/- 0.7 min, and then rose progressively to 14.6 +/- 0.8 mM at the end of 30 min of ischemia. Glibenclamide (50 microM) reduced the initial peak of [K+]e to 7.2 +/- 0.3 mM (P less than 0.01), and nicorandil (200 microM) increased it to 9.4 +/- 0.6 mM (P less than 0.01). There were no significant differences in [K+]e values among all groups at the end of ischemia. During ischemia, nicorandil decreased the time to mechanical arrest from 1.9 +/- 0.1 min to 1.5 +/- 0.1 min, whereas it was increased by glibenclamide to 2.7 +/- 0.4 min. In control hearts, the time to onset of ischemic contracture was 14.7 +/- 1.8 min. Nicorandil delayed onset of contracture and glibenclamide accelerated it. Thus we have confirmed that some part of the early increase in [K+]e during ischemia is attributable to K+ efflux through the KATP channel in our model, and opening of the KATP channel may contribute to a rapid reduction of the contractility of the ischemic myocardium that subsequently protects the myocardium against further ischemic injury.

Adenosine Triphosphate↗

PubMed1991

Influence of pregnancy on the serum prolactin level following prolactinoma surgery.

We studied the influence of pregnancy on the serum prolactin levels after surgery in 35 patients with prolactinomas. Eighteen out of 22 patients with postoperative normalization of the prolactin level were able to achieve repeated spontaneous pregnancies and endocrine cure by surgery alone, but the other 4 had recurrent hyperprolactinemia. Thirteen patients with persistent hyperprolactinemia after surgery achieved one pregnancy with or without bromocriptine treatment, but did not achieve a second one owing to an increase in the prolactin level after delivery. None of the patients with postoperative hyperprolactinemia showed spontaneous normalization of the prolactin level or restoration of menstruation after delivery. In these 13 patients, the mean increase from the postoperative to the post-delivery prolactin level was less for the patients with bromocriptine-induced pregnancy than for those with spontaneous pregnancy. It is concluded that pregnancy did not adversely affect the serum prolactin level in the patients with a normal postoperative level.

Adult↗

PubMed1991

Outcome of primary central nervous system lymphoma--a study of 32 patients.

The outcomes in 32 cases of histologically diagnosed primary central nervous system lymphoma were investigated. The 1-, 2-, and 5-year survival rates were 54, 36, and 8%, respectively. Good outcome was indicated by extensive surgical removal with 50-Gy irradiation and lower ages. 61% of patients receiving radiation therapy suffered recurrence within 1 year. The incidence of multiple lesions increased at recurrence. These lesions were almost all remote from the initial site in the brain, occurring more frequently in the central part of the supratentorial regions near the ventricle. Multiple lesions recurred more rapidly than single lesions. Longer survival times were indicated by a long tumor-free period after initial treatment. Extensive surgical removal results in long survival times for patients with a localized single tumor in the early stage. Radiochemotherapy should be given as part of the initial treatment.

Adolescent↗

PubMed1991

[Establishment of ACNU-resistant rat gliosarcoma cell lines and their characteristics].

One of the most serious problems in cancer chemotherapy is the acquired drug resistance of tumor cells. In order to investigate the mechanism of acquired resistance to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU), nine resistant cells were isolated from rat gliosarcoma 9L cells and characterized. ACNU-resistant cells were easily isolated after a single treatment even with low-dose ACNU (5 micrograms/ml). However, in spite of repeatedly high-pressure dose of ACNU, more than 30 fold increase to parental 9L cell resistance was not achieved. At this time, further increase in selection pressure resulted in cell death. The resistant ratios of these resistant cells were stable in the absence of ACNU for more than 1 year. Luria and Delbrück's fluctuation test indicated that the appearance of ACNU-resistant cells occurred spontaneously at a rate of (4.40-8.02) x 10(-7)/cell/generation. In karyotypic analysis, the mode was higher in the resistant cells than in 9L cells, but a homogeneously staining region or double minute chromosome, which was considered to be a result of gene amplification, was not observed. In growth kinetics, all the resistant cells except R1 and R12 cells had higher saturation density and plating efficacy than parental 9L cells. These findings seemed to be due to cellular modification associated with ACNU resistance.

Animals↗

PubMed1991

Cross-resistance patterns in ACNU-resistant glioma sublines in culture.

Three ACNU-resistant clones (R1, R3, and R12) were isolated from 9L rat glioma cells under selection pressure of ACNU in vitro. The authors have investigated the mechanisms of resistance and characteristics of these clones at the cellular level by studying cross-resistance patterns to chemical and physical agents. Although these resistant sublines showed complete cross-resistance to methyl-chloroethylnitrosourea (MCNU), no cross-resistance was observed for other alkylating agents, while each of the resistant sublines showed partial cross-resistance to structurally dissimilar toxic agents (vinblastine, Adriamycin, and VP-16). No difference in ACNU uptake was observed between 9L and R3 cells, and resistance patterns among alkylating agents suggested that the mechanism of ACNU resistance was specific to bifunctional nitrosoureas. Based on a transport study, this multidrug resistance could be explained by reduced intracellular uptake of these drugs, but there seemed little possibility that membrane P-glycoprotein, which usually is observed in typical multidrug-resistant cells, was expressed in these ACNU-resistant cells because enhanced drug efflux was not found in ACNU-resistant sublines. Significant collateral sensitivity to L-asparaginase indicated that ACNU might disturb the asparagine synthetic pathways by its mutagenic action. The increased level of total glutathione in the resistant sublines may be one mechanism of radiation or ACNU resistance.

Animals↗

PubMed1991

Hypersensitivity of rat glioma sublines with acquired ACNU resistance to L-asparaginase.

Cell lines resistant to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) show a high degree of collateral sensitivity to L-asparaginase. The mechanism for this phenomenon was investigated by comparing the nutritional requirements and asparagine synthetase activity of the resistant sublines to those of parent cells. Nine ACNU-resistant sublines were isolated from rat glioma 9L cells after incubation with various concentrations of ACNU in Ham's F-12 medium. The 9L cells grew independently of asparagine, developing well in asparagine-deficient Dulbecco's modified Eagle's medium. In contrast, the growth rates of all nine ACNU-resistant sublines decreased under the same conditions and required the addition of 10(-4) M asparagine for maximum growth. Asparagine synthetase activity in the ACNU-resistant cells was much lower than in the 9L cells, suggesting that the requirement for asparagine in the resistant sublines was due to reduced activity of this enzyme. A growth-inhibition assay showed that the ACNU-resistant sublines were more sensitive to L-asparaginase than 9L cells by up to 2 x 10(5)-fold. These results suggest that L-asparaginase therapy has the potential to become a new approach for treating acquired ACNU resistance.

Animals↗

PubMed1991

[Effects of EGF and retinoic acid on differentiation of squamous cell carcinoma cells].

Using monoclonal antibody, G6K12, a novel differentiation marker of keratinocyte, we examined the effect of EGF and retinoic acid on the differentiation of SCC-25, a cell line established from human squamous cell carcinoma. EGF inhibited the expression of cell-surface differentiation marker in low cell-density, but not in high cell-density. Retinoic acid (more than 10(-8) M) inhibited the expression of the antigens. The terminal differentiation of SCC-25 cells occurred at the condition of high cell density. These results obtained demonstrate that EGF and retinoic acid inhibit the terminal differentiation of SCC-25 cells, and that the cell density is the important factor for the commitment of the terminal differentiation.

Carcinoma, Squamous Cell↗

PubMed1991

Establishment and characterization of human medulloblastoma xenograft line.

A new xenotransplantable tumor line, MED-FU, was derived from a 6-year-old female patient with cerebellar medulloblastoma. This tumor was grown in nude mice as serially transplantable subcutaneous xenografts composed of small round cells with hyperchromatic nuclei and scant cytoplasm. Many rosettes and mitoses were observed. Immunohistochemically, glial fibrillary acidic protein (GFAP), S-100 protein, and neuron specific enolase (NSE) were not detected. The doubling time of the subcutaneous tumors was 6.8 days. Highly concentrated polyamines were detected in the tumor tissue and serum of tumor-bearing mice. This xenotransplanted tumor line, MED-FU, is considered to provide an available experimental model for the study of human medulloblastoma.

Animals↗

PubMed1991

[Selective enhancement of tumor blood flow and drug delivery to brain tumors in experimental rat gliomas under angiotensin II-induced hypertension].

Regional blood flow of brain tumors and normal brain tissue of rats before and during angiotensin II (AT II)-induced hypertension were measured using an electrolytic flowmeter and a laser flowmeter. Etoposide concentration in the tumor and brain tissue after intracarotid administration were also measured in brain tumor bearing rats with or without AT II-induced hypertension. A suspension of 5 x 10(5)/10 microliters 9L gliosarcoma cells was inoculated into the left caudate-putamen of CD Fischer 344 rats. Before induced hypertension, regional blood flow of the tumor (28.2 +/- 2.6 ml/100 g/min; mean +/- SEM) and the contralateral caudate-putamen (23.0 +/- 1.8 ml/100g/min) in the tumor bearing rats were significantly lower than that of the caudate-putamen (43.9 +/- 4.1 ml/100g/min) in the normal rats (p less than 0.01). Intravenous administration of AT II at a dose of 0.4-0.6 microgram/body/min increased the mean arterial blood pressure from 96.5 +/- 4.7 mmHg to 138.0 +/- 3.6 mmHg. AT II-induced hypertension resulted in an approximate 1.8(1.1 - 3.6)-fold increase in the regional tumor blood flow. On the other hand the regional blood flow of the contralateral caudate-putamen was slightly decreased at the rate of 6%. The mean concentration of etoposide with AT II-induced hypertension in the tumor tissue was 2.2-fold higher than that without AT II-induced hypertension. However, etoposide delivery to normal brain tissue was small. From these results, induced hypertension with intravenously administrated AT II selectively increase the tumor blood flow and drug delivery to brain tumor tissue. Intracarotid chemotherapy with AT II-induced hypertension might contribute to enhance therapeutic effect of malignant brain tumors.

Angiotensin II↗

PubMed1991

[A case of pituitary adenoma with simultaneous secretion of TSH and GH detected by double immunostaining method].

A rare case of simultaneous hypersecretion of thyroid stimulating hormone (TSH) and growth hormone (GH) in a pituitary adenoma is reported. A 59-year-old male complaining of general fatigue, dyspnea on exertion and finger tremor was admitted. Examination on admission, he revealed with hyperthyroidism and hypersecretion of TSH and thyroid hormones. Administration of TRH did not further increase serum TSH level, and administration of T3 also had no effect on TSH secretion. CT scan showed a pituitary macroadenoma 13mm in diameter. MRI demonstrated a homogenously hypointense mass with Gd-DTPA enhancement in the left side of the sella turcica. The entire chromophobic adenoma was removed by trans-sphenoidal surgery. Immunostaining of the specimen showed that the cytoplasm of the adenoma cells was positive for both TSH and GH. Double immunostaining using avidin-biotin-peroxidase complex (ABC) method and immunogold silver staining (IGSS) method, showed that the adenoma cells had been secreting both GH and TSH at the same time. After the adenomectomy, the hyperthyroidism disappeared, and all altered indicators of pituitary function returned to normal.

Adenoma, Chromophobe↗