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Biomedical subjects

M Abe

Publications and source records attributed to M Abe.

At least 1,279 records · Page 71Linked to original sources
PubMed1985

Recovery from potentially lethal damage after X-irradiation in three experimental tumors in mice.

Potentially lethal damage repair or recovery (PLDR) after X-irradiation was examined in three experimental murine tumors, EMT6 sarcoma, SCCVII carcinoma and RIF1 sarcoma, by an in vivo-in vitro assay. All tumors were transplanted subcutaneously (SC) and, in the case of EMT6, also intradermally (id), in the thighs of syngeneic mice. Apparent PLDR was observed at high dose levels in the id and sc EMT6 sarcomas and in the sc SCCVII carcinoma, but not in the sc RIF1 sarcoma. In both id EMT6 and SCCVII tumors, PLDR appeared to be complete within 9 hr after X-irradiation. Dose-modifying factors due to PLDR evaluated at the surviving fraction of 0.01 were 1.34, 1.15, 1.24 and 0.97 for id EMT6, sc EMT6, SCCVII and RIF1 tumors, respectively. The amount of PLDR correlated inversely with the velocity of tumor growth in vivo, suggesting that slowly growing tumors might be proficient in PLDR. Although PLDR in id EMT6 and SCCVII tumors was evident in the dose range above 15 Gy, the capacity to recovery from PLD became smaller at lower doses; in SCCVII tumors, this phenomenon was negligible below 7.5 Gy. PLDR did not seem to be a major factor influencing the radiocurability of these murine tumors, especially at low dose levels.

Animals↗
PubMed1985

[Radiotherapy of pancreatic carcinoma].

During the 10-year period between 1974 and 1984, we treated 34 pancreatic carcinomas by radiotherapy as follows: Eight by intraoperative radiotherapy (IOR), five by external radiotherapy (ERT), and 21 by IOR in combination with ERT. The mean survival time of the eight patients treated by IOR was 5.6 months, and that of the 21 receiving the combination therapy 7.2 months. Although it is not statistically significant, patients treated by the combined regimen survived longer than those treated by IOR alone.

Aged↗
PubMed1985

[Multidisciplinary treatment of cancer of the pancreas].

During the past 18 and a half years, 285 patients with cancer of the pancreas have been treated in our hospital. By means of en-bloc resection of the lesion with the portal vein and/or hepatic artery, the resectable rate of cancer of the head of the pancreas was improved to 53% (1979-1983) from 22% (1966-1978). Postoperative deaths within 30 days after pancreatectomy were 9.8%. The five years survival rate in those with Stage I and II was 28.7%, but that with Stage III and IV was 15.2%. Intraoperative and/or external radiation therapy was adopted on 16 patients, in some of whom hyperthermia was further combined. As a result, remarkable effects on performance status were obtained. Intra-arterial infusion chemotherapy using a transfemorally implanted catheter was performed on ten patients with unresectable lesions, the median survival of whom was however, only four and a half months.

Adult↗
PubMed1985

Diagnosis of small pancreatic carcinoma.

A retrospective analysis was performed to evaluate the clinical symptoms and abnormal test findings in small pancreatic carcinoma. Five hundred and thirty-six cases of pancreatic carcinoma with the histology of duct cell carcinoma were collected from 14 medical centers in Japan. In 440 of the cases, tumor size was measured at the time of laparotomy or from the resected specimen. Three hundred and seventy-seven patients (86%) had a carcinoma larger than 3.0 cm; only 30% of these were resectable. Sixty-three patients (14%) had a carcinoma of 3.0 cm or less, with resectability of 97%. Detecting a tumor of "3 cm or less" with a high probability of resectability is the objective of early diagnosis with the resulting possibility of a cure. In most cases these small carcinomas were found easily when obstructive jaundice was present (73%). However, the estimated occurrence of obstructive jaundice associated with carcinomas of 3 cm or less was only 10% among the total cases of pancreatic carcinoma studied. Therefore, it is necessary for early diagnosis to detect carcinomas of 3 cm or less presenting without jaundice. The symptoms of small carcinoma without jaundice are weight loss, anorexia, upper abdominal pain, back pain and a palpable abdominal mass. Among the various available examinations, endoscopic retrograde cholangiopancreatography, computerized tomography and ultrasonography were valuable in diagnosing these small carcinomas.

Cholestasis↗
PubMed1985

[Puncture technology and selective renal biopsy].

An experimental study of puncture technology for the kidney: We investigated the strength characteristics of tissues which are penetrated by the puncture needle for the kidney using a tension test. The tensile strength of the fascia, the muscle, the renal capsule, the renal parenchyma and the renal pelvis were 13.9, 1.1, 29.5, 0.5 and 21.4 kg/cm2, respectively. As the strengths differ, the needles for each tissue clearly need to be changed. Needle tip shape and needle material for kidney puncture were investigated by compression test, acryl resin injection into the renal vasculature, stereo-microscopy and scanning electron microscopy. These investigations revealed that the most suitable needle tip was a sharp cone shape, and material with a smooth surface and some flexibility such as Derlin seemed to be the most appropriate for the puncture needle for the kidney. Using the acryl resin injection method, stereo-microscopy and scanning electron microscopy, we studied the relative safety of single stage puncture and the repeated dilatation method to establish percutaneous nephrostomy. Single stage puncture seems to cause less damage to the kidney than the repeated dilatation method. Selective renal biopsy: A new puncture system using real-time ultrasound was developed at our clinic in 1978. The puncture procedure is monitored in 2 dimensional real-time images by a mechanical sector scanner equipped with an attachment for needle guidance. The application of the system to percutaneous renal biopsy is called "selective renal biopsy" because the specimen can be obtained selectively from any portion of the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1985

[Physical dose distribution].

In radiotherapy planning it is essential to compose dose distribution curves on a transverse section of patient. For this purpose we have developed the radiotherapy planning system using a computer (Modulex), in which CT images and CT numbers were input on off-line with a CT magnetic tape, CT numbers were converted into relative electron densities and then, dose distribution curves calculated were output directly on CT images. One of problems lying in this system was that the three-dimensional dose distribution had to be surmised with a couple of two-dimensional ones. Clinical application of this system has been applied to planning of intraoperative radiotherapy that was considered to provide ideal dose distributions, and its effectiveness was discussed.

Computers↗
PubMed1984

Clinical results of radiofrequency hyperthermia combined with radiation in the treatment of radioresistant cancers.

Clinical results of radiothermotherapy applied to 40 radioresistant tumors in 36 patients were reported. Hyperthermia was administered locally using two radiofrequency (RF) capacitive heating equipment systems developed in our institution under the collaboration of Yamamoto Vinyter Co. Ltd. Hyperthermia was given twice weekly immediately after irradiation. Intratumor temperatures of 41 degrees C to 44 degrees C were maintained for 30 to 60 minutes. Radiation doses varied from 32 Gy to 60 Gy. Of the 40 tumors treated, 21 (53%) showed complete response, 16 (40%) partial response, and 3 (7%) no response when the tumor response was assessed by tumor size measurement. Of eight patients who had matched tumors treated with either radiation alone or radiation plus hyperthermia, six patients showed better response in tumors treated with radiothermotherapy than in tumors treated with radiation alone. Skin reactions following radiothermotherapy and radiation alone were comparable. The tumor response was greatly dependent on the tumor size. Greater response was observed in small tumors, although histologic examinations and long-term follow-up studies revealed an excellent effect of radiothermotherapy on the large tumors as well as on the small tumors. Tumor responses correlated with tumor center temperatures but not with histologic features. Our clinical results indicate that RF hyperthermia combined with radiation has a therapeutic benefit in the treatment of radioresistant cancers.

Body Temperature↗
PubMed1984

[The effect of methyleneblue on insulin and glucagon release stimulated by glucose and arginine in the isolated perfused rat pancreas].

To examine the role of NADPH in the release of insulin and glucagon, isolated rat pancreata were perfused with methyleneblue, which is known to oxidize NADPH. Hormonal release was stimulated by changes in arginine or glucose concentrations as follows. After establishing the basal secretion state during perfusion at various glucose levels for 10 min., pancreata were stimulated by the addition of arginine or a change in glucose concentration of the perfusate for 15 min. Conditions for the stimulation were: (A) addition of 10 mM arginine at constant 4 mM glucose concentration; (B) increase in glucose concentration from 2.8 mM to 11.1 mM, or (C) decrease in glucose concentration from 11.1 mM to 2.8 mM. In some experiments, methyleneblue was added throughout the perfusion period at 1 or 3 micrograms/ml. The effluent from the portal vein was collected over 1 minute intervals: Insulin and glucagon concentrations in the effluent were determined by radioimmunoassay. Insulin release. Stimulation by the addition of arginine and increased glucose concentration produced a typical biphasic insulin response. In both cases, 1 microgram/ml methyleneblue reduced the second phase, and 3 micrograms/ml methyleneblue inhibited both phases almost completely. Glucagon release: Stimulation by arginine and inhibition by increasing glucose concentration were not influenced by methyleneblue; however, glucagon release induced by lowering of glucose concentration was suppressed by 3 micrograms/ml of methyleneblue. Thus, methyleneblue specifically inhibits glucose- and arginine-induced insulin release while it has no effect on arginine-induced glucagon release.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Genetic regulation of GM2 (NeuGc) expression in liver of mouse.

GM2 containing NeuGc was a major ganglioside in mouse liver of inbred strains such as DBA/2, BALB/c, C57BL/10 and C3H/He, which are commonly used for biochemical and immunological studies. On the other hand, the liver of WHT/Ht, an inbred strain, contained GM3 (NeuGc) as a major ganglioside and lacked GM2 (NeuGc). We report here that the GM2 (NeuGc) expression was analyzed in the liver of the progeny between WHT/Ht and DBA/2 and the positive expression of GM2 (NeuGc) was proved to be a dominant trait regulated by an autosomal single gene. Moreover, the N-acetylgalactosaminyltransferase activity to convert GM3 (NeuGc) to GM2 (NeuGc) was measured in the liver microsomal fraction of WHT/Ht, BALB/c and their F1. F1 expressed almost half of the activity in BALB/c and WHT/Ht did not express a detectable amount of activity. The backcross of F1 to WHT/Ht segregated into two groups. One expressed both GM2 (NeuGc) and the transferase activity and the other expressed neither of them. There was no exceptional individual which was not grouped into either of these two groups. These results indicate that GM2 (NeuGc) expression is directly regulated by the N -acetylgalactosaminyltregated into two groups. One expressed both GM2 (NeuGc) and the transferase activity and the other expressed neither of them. There was no exceptional individual which was not grouped into either of these two groups. These results indicate that GM2 (NeuGc) expression is directly regulated by the N-acetylgalactosaminyltransferase activity, the expression of the enzyme activity is regulated by an autosomal single gene and WHT/Ht is a mutant of the recessive homozygote which cannot express the enzyme activity in its liver. WHT/Ht does not develop any neurological symptoms but grows and breeds well. The brain ganglioside composition was proved to be identical to those in BALB/c brain. The result suggests that WHT/Ht has N-acetylgalactosaminyltransferase to convert GM3 (NeuAc) to GM2 (NeuAc) in its brain. It is a subject for further study to elucidate what kind of defect is involved in the GM2 (NeuGc) biosynthesis of WHT/Ht liver.

Animals↗
PubMed1984

Cell-mediated cytotoxic islet cell surface antibodies to human pancreatic beta cells.

Sera containing islet cell surface antibodies show a complement-dependent cytotoxic reaction against islet cells, but it has not yet been clarified whether islet cell surface antibodies exhibit cell-mediated cytotoxicity to these cells. By 51Cr release assay we investigated whether islet cell surface antibodies showed a cytotoxic reaction to human pancreatic B cells (JHPI-1 clone) in the presence of normal human lymphocytes. The sera from 14 islet cell surface antibody-positive, 16 islet cell surface antibody-negative Type 1 (insulin-dependent) diabetic patients and 18 islet cell surface antibody-negative healthy subjects were studied. Four sera containing islet cell surface antibodies showed specific cytotoxicity above the mean +3SD value of healthy subjects, and the mean specific cytotoxicity of islet cell surface antibody-positive sera differed significantly from that of both islet cell surface antibody-negative groups. These results suggest that this cell-mediated cytotoxic mechanism may play an important role in the pathogenesis of Type 1 diabetes.

Adolescent↗