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M Abe

Publications and source records attributed to M Abe.

At least 1,027 records · Page 57Linked to original sources
PubMed1989

Variation in tumor response to fluosol-DA (20%).

The effects of Fluosol-DA 20% (FDA) and carbogen (95% O2/5% CO2) on radiosensitivity of the three experimental tumors, SCC VII tumor, RIF-I tumor, and transplanted mammary tumor of C3H/He mouse, subcutaneously inoculated in the leg were examined. The effect of FDA plus carbogen, and carbogen alone on radiosensitivity of SCC VII and RIF-I tumors was tested using the in vivo-in vitro assay. The growth curves were obtained for both SCC VII tumor and transplanted mammary tumor. The effect of the combination of FDA and carbogen was only observed in the transplanted mammary tumor. In the other two tumors, only the effect of inspiring carbogen was observed. We concluded that the effect of FDA on the radiosensitivity of experimental tumors varies with the kind of tumor systems.

Animals↗
PubMed1989

Radiation therapy for brain stem tumor with special reference to CT feature and prognosis correlations.

Seventy-nine patients with tumors of the medulla oblongata, pons, and midbrain treated by radiation therapy between 1962 and 1987 were analyzed. According to histology obtained in 28 cases, 61% were high-grade astrocytomas and 39% were low-grade astrocytomas. The 5- and 10-year survival rates of 71 patients who completed radiotherapy were 17 and 15%, respectively. Various potential prognostic factors were analyzed, and patients with a midbrain tumor, with a low-grade tumor, and without cranial nerve paresis were found to have a better prognosis. Computed tomography (CT) was performed both before and after radiotherapy on 42 patients. The volume of the tumor estimated from the CT image was various, but the tumors could be classified into three types according to the pattern of contrast enhancement (CE). Twenty-three tumors showed no CE, 15 showed a diffuse CE, and 4 showed a ring CE. No-CE tumors were generally hypodense on plain scan and were mostly large, whereas diffuse- or ring-CE tumors were relatively small. A complete response (CR) or partial response was obtained with 77% of the no-CE tumors, 64% of the diffuse-CE tumors, and 50% of the ring-CE tumors. The CR rate was higher in the tumors with a smaller volume. The 5-year survival rates for diffuse-CE, no-CE, and ring-CE tumors were 33, 15, and 0%, respectively. The 5-year survival rate was 56% for tumors smaller than 6 cm3, 16% for tumors between 6 and 20 cm3, and 0% for tumors larger than 20 cm3. In conclusion, (a) ring-CE tumors exhibited a poor prognosis; and (b) a diffuse-CE tumor, or a small or middle-sized no-CE tumor is most likely to be controlled by conventional radiation therapy.

Adolescent↗
PubMed1989

Histopathological changes of human tumors following thermoradiotherapy.

Twenty human malignant tumors treated with thermoradiotherapy were examined histopathologically. Hyperthermia was administered regionally with a 13.56-MHz or 8-MHz RF heating device, once or twice a week after irradiation, 2 to 12 sessions in total. Fifteen tumors received a total radiation dose of 26 to 70 Gy in fractions of 1.8 Gy to 2.0 Gy a day, 5 days a week, whereas five tumors received a total dose of 20 to 60 Gy in fractions of 4 Gy each, twice a week. Microscopic examination of 4 of the 20 tumors revealed complete necrosis throughout the cross-section of the entire tumor. All the four tumors had received a total dose of over 60 Gy and a tumor center temperature of over 42 degrees C. In 10 tumors, more than 50% but less than 99% of the cross-section of the entire tumor had massive coagulation necrosis. The remaining six tumors showed relatively little change; the area of intratumor necrosis was less than 50%. The grade of tumor necrosis was dependent on both the temperatures of tumor center and periphery, and a total radiation dose. The small blood vessels and capillaries in the tumor parenchyma were markedly damaged in 16 of the 20 tumors, while the blood vessels in the tumor stroma were damaged in only 2 tumors. Condensation of the destroyed nucleus observed in 15 tumors was considered to be a typical change induced by thermoradiotherapy. Viable tumor cells remained in the tumor central area in only four tumors and around the blood vessels in only three tumors. However, in the tumor peripheral area, viable tumor cells were observed in 16 out of the 20 tumors. These results indicate that histopathological changes induced by thermoradiotherapy are greater in the tumor central area than in the tumor peripheral area, and provide strong rationale for utilizing full dose radiation therapy in combination with hyperthermia as opposed to lower doses for cancer therapy.

Adult↗
PubMed1989

KIH-802: 2-nitroimidazole-1-acetohydroxamate as a hypoxic cell radiosensitizer.

We have identified potassium 2-nitroimidazole-1-acetohydroxamate (KIH-802) as a hypoxic cell radiosensitizer potentially superior to Miso. The water-soluble acetohydroxamates of 2-nitroimidazole (KIH-802; free acid 801) and 4-nitroimidazole (KIH-852) were designed, synthesized, and evaluated by in vitro and in vivo screening against EMT6 cells. Enhancement ratios of KIH-802 and 801 were 1.92 and 1.68, respectively, compared with 1.58 for MISO all at 1 mM. These acetohydroxamates are also expected to be more effective in vitro than SR-2508 based on our previous experiments. In vivo ERs of KIH-802, 801, and 852 were 1.75, 1.50, and 1.35, respectively, compared with 1.57 for MISO all at the same dose of 200 mg/kg. The data clearly show that the addition of an acetohydroxamic acid moiety to the 2-nitroimidazole skeleton can enhance radiosensitizing ability.

Animals↗
PubMed1989

Importance of tumor affinity of nitroazoles in hypoxic radiosensitization.

In vitro and in vivo sensitizing activities of a variety of nitroazole derivatives including misonidazole (MISO), SR-2508, and RSU-1069 were correlated by the aid of pharmacokinetic measurements of the drug uptake in animal solid tumors. The sensitizer enhancement ratio in vivo (SERvivo) on solid tumors increased linearly with the square root of administrated dose (Ds). The specific activity (A) in vivo of nitroazoles was evaluated from the square-root empirical relationship, SERvivo = 1.00 + A D1/2S. The intratumor concentration of nitroazoles at a given time t after administration was in proportion to the DS, in which the proportional constant was defined as the tumor-affinity factor FT,t. The absolute molar activity alpha M defined by A(M/FT,t)1/2, where M is the molecular weight of nitroazoles, showed a linear relationship with the SER in vitro (SERvitro) at 1 mM of sensitizers. The sensitizer dose required to achieve an SERvivo of 1.5 (DS,1.5) decreased and thus the overall sensitizing efficiency on animal solid tumors increased as the FT,t became greater.

Animals↗
PubMed1989

Characteristics of fluorinated nitroazoles as hypoxic cell radiosensitizers.

Types of 2-nitroimidazoles and 3-nitro-1,2,4-triazoles bearing one or two fluorine atoms on their side chains were synthesized to evaluate their physicochemical properties, radiosensitizing effects, and toxicity. The reduction potential of the compounds containing one fluorine was similar to that of misonidazole (MISO), whereas that of the difluorinated compounds was slightly higher. Both mono- and difluorinated compounds had an in vitro sensitizing activity comparable to or slightly higher than that of MISO. The fluorinated 3-nitrotriazoles were almost as efficient as the 2-nitroimidazoles with the same substituent. In vivo, some of the compounds were up to twice more efficient than MISO, whereas others were as efficient as MISO. Toxicity in terms of LD50/7 in mice was quite variable depending on the side-chain structure; the amide derivatives were less toxic than MISO, whereas the alcohol and ether derivatives were more toxic. In view of the radiosensitizing effect and toxicity in vivo, at least one compound, KU-2285 (a 2-nitroimidazole with an N1-substituent of: CH2CF2CONHCH2CH2OH) has been found to be as useful a hypoxic cell sensitizer as SR-2508.

Animals↗
PubMed1989

The effect of arterial oxygen content on the results of radiation therapy for epidermoid bronchogenic carcinoma.

Anemia is believed to be an important prognostic factor in treating cancer patients by radiation therapy. One possible explanation for this is tumor oxygenation. With respect to tumor oxygenation, the arterial oxygen content (CaO2) may be of more importance than the hemoglobin (Hb) level. This study shows the relationship between the CaO2 and tumor response to radiation therapy. Forty-two patients with epidermoid bronchogenic carcinoma, treated by irradiation alone between April 1982 and March 1986, were reviewed. Regression of the tumor after radiation therapy was calculated as a percent change in the tumor area. Arterial oxygen partial pressure (PaO2), Hb level, and percent oxygen saturation of Hb in arterial blood (SaO2) were measured within 2 weeks of commencement of radiation therapy and the CaO2 was calculated. The rank correlation coefficients between the maximum percent regression of the tumor and the PaO2, the Hb level and the CaO2 were 0.36, 0.34, and 0.46, respectively. Statistical analyses of the data indicate that the group of patients with CaO2 over 14.5 ml/dl exhibited greater tumor regression and longer survival periods than the group of patients with CaO2 below 14.5 ml/dl. Similarly patients with PaO2 over 90 mmHg or Hb level over 11 g/dl, exhibited significantly greater tumor regression and longer survival periods than those with PaO2 below 90 mmHg and Hb level below 11 g/dl. There were no significant differences in the length of survival periods with respect solely to the Hb level or the PaO2. It was concluded that the CaO2 is more important than the Hb level in determining tumor response to radiation therapy. This is considered as important indirect evidence of the existence of hypoxic fractions of cells in human tumors.

Adult↗
PubMed1989

Mechanism whereby holotrich ciliates are retained in the reticulo-rumen of cattle.

The concentrations of holotrichs, reducing sugars and fermentation end-products, and the fluid dilution rates, in the cranial (CR), ventral (V) and caudal (CA) regions of the reticulo-rumen of cows were compared. Additionally, holotrich numbers in fluid and solid digesta samples taken from the dorsal (D) region were determined at different time-intervals. Holotrich numbers expressed per ml fluid at site D were almost twofold those expressed per g solid digesta, and the fluctuation of their numbers in fluid preceded that in solid digesta. Holotrich concentrations at site CR were higher before feeding than after feeding, while those at sites V and CA were lower before feeding than for a few hours after feeding. At sites V and CA, holotrich concentrations fluctuated in good agreement with reducing sugar concentrations, but the increase in the former always preceded that in the latter. The concentration of volatile fatty acids (VFA) tended to decrease from site CA to site CR, while the dilution rate was highest in site CR. The results suggest that migration of holotrichs from the reticulum to the rumen and vice versa are the cause of fluctuation in their numbers, and also the mechanism by which they are retained in the rumen of cattle.

Ammonia↗
PubMed1989

Are Ly1 B cells responsible for the IL2-hyperresponsiveness of B cells in autoimmune-prone NZB x NZW F1 mice?

Unlike splenic B cells from normal BALB/c mice, those from autoimmune-prone NZB x NZW (B/W) F1 young mice were hyperresponsive to interleukin 2 (IL2) and proliferated even in the absence of prior stimulation signals. We found that the B cell subpopulation responsible for this event belongs to that with 6B2 (B220)-dull, Ly1(CD5)-positive phenotypes. Cell cycle analysis revealed that the 6B2-dull, Ly1 B cell subpopulation contains a significant number of cells at stages of G1A and G1B, while the majority of 6B2-bright B cells belongs to GO. Therefore, it appears that most of the 6B2-dull, Ly1 B cells in young B/W F1 mice are already stimulated in vivo to the stage of early activation, so that they respond to IL2 without prior stimuli. Unlike other strains of mice, including parental NZB and NZW, the B/W F1 mice showed a rapid decrease in the proportion of splenic Ly1 B cells, beginning at about 6 months of age. This was associated with the hyporesponsiveness to IL2 of 6B2-dull splenic B cell population in the old B/W F1 mice. This phenomenon seems to relate to further activation and differentiation, which occur in Ly1 B cells with aging.

Aging↗
PubMed1989

The novel murine B cell differentiation antigen Lp-3.

The unique murine lymphocyte differentiation antigen, Lp-3, with a mol. wt of approximately 125 kd, was found using a rat monoclonal antibody. The Lp-3 antigen was distributed on a wide variety of myeloid, T cell, and B cell lineages in mice. However, the expression was only found in B cells at certain stages of differentiation. The pre-B and virgin B cells in the bone marrow from 2-month-old BALB/c mice were weakly positive for Lp-3, while the resting B cells in the spleen and lymph node were Lp-3 negative. In contrast, the majority of B cells in the peritoneal cavity, mostly Ly-1 (CD5) B cells, had a brighter fluorescence for Lp-3 than did bone marrow B cells. The Lp-3 antigen could be induced in a high density in approximately one-half of lipopolysaccharide-stimulated, large, blastic spleen B cells. Cell cycle analysis showed that Lp-3 is an early B cell activation antigen which is first expressed at the G1A phase of the cell cycle. Therefore this novel B cell differentiation antigen will be useful for differentiating pre-B and virgin B cells in the bone marrow, resting B cells, and a population of activated B cells in the periphery. In contrast to findings in BALB/c mice, there was an elevated population of B cells with a bright Lp-3 expression in the spleen of autoimmune-prone NZB x NZW F1 mice.

Animals↗
PubMed1989

Preferential usage of JH2 in D-J joinings with DQ52 in murine lymphocytes.

Southern blot analysis of genomic DNA of normal mouse thymocytes with a JH4 probe, a probe for JH4 of Igh genes, consistently showed a second band in addition to a germline band. The same band was also observed in analysis with a 5' DQ probe, a 5'-flanking sequence of DQ52, thus suggesting the use of DQ52. By analyzing EcoRI- and PvuII-digested genomic DNA, the above-observed band was demonstrated to be the result of DQ52-JH2 joining. This was further confirmed utilizing a T cell leukemia line with known DQ52-JH joinings. We then quantitatively estimated the frequencies of JH segment usages in joining with DQ52, through plaque hybridization assays. Three hundred and fifty JH4-positive clones were obtained from 7 x 10(5) plaques by plaque hybridization. Forty-eight randomly selected non-germline clones were purified and the use of JH segments was determined through Southern blot analysis. Nine clones used JH1, 29 used JH2, 9 used JH3, and 1 used JH4, thus indicating an apparent preferential usage of JH2 segment. Southern blot analysis of genomic DNA of progenitor B cells in culture showed a dominant band of DQ52-JH2 joining 1 week after initiation of culture. This may indicate that the dominant DQ52-JH2 joining in thymocytes is representative of early D-J joinings in progenitor B cells.

Animals↗
PubMed1989

Surgical treatment of metastatic tumors of the spine.

The goal of surgical treatment of metastatic spinal tumors is to maintain neurologic functioning without pain for the duration of the life expectancy. Of 28 patients in this series, 25 who had metastasis in the vertebral body underwent direct decompression by removal of the tumor, followed by vertebral reconstruction. A combined anterior or posterior instrumentation provided rigid spinal stability immediately after surgery. Three patients with involvement of the posterior part of the vertebra were treated by laminectomy for removal of the tumor, followed by posterior instrumentation. As a result, of nine patients who are alive with improved neurologic functions, seven have been ambulatory for an average duration of 13 months. Of 19 patients who have already died, recurrence of neurologic deficits was observed in five (26%), and 14 had no neurologic deterioration until they succumbed to the malignancy. Removal of the tumor and reconstructive surgery may be expected to produce satisfactory results.

Adult↗
PubMed1989

Increased expression of ras genes in non-Hodgkin's lymphomas is not associated with oncogenic activation of those genes by point mutation.

Twenty-three cases of non-Hodgkin's lymphoma (NHL) were analyzed for expression of ras genes by in situ hybridization utilizing biotinylated DNA probes. Increased expression of Ki-ras, Ha-ras and N-ras genes was observed in 12 cases, 6 cases and 1 case of NHL, respectively. Genomic DNA extracted from these 23 cases of NHL was region-specifically amplified by means of polymerase chain reaction to examine the presence of point mutations at the 12th, 13th and 61st codons of Ki-, Ha- and N-ras genes. Dot hybridization assays with appropriate oligonucleotide probes showed no evidence of point mutation in any case of NHL examined. These results indicate that increased expression of ras genes in NHL is not associated with ras gene activation by point mutation.

Base Sequence↗
PubMed1989

A new, potent 2-nitroimidazole nucleoside hypoxic cell radiosensitizer, RP170.

The radiosensitizing activity, acute toxicity and pharmacokinetics of RP170, a new hypoxic cell radiosensitizer, were compared with those of misonidazole (MISO) and SR2508. RP170 belongs to the group of 2-nitroimidazole nucleosides, which are designed to be selectively excluded from the neural tissue. The reduction potential of RP170 was similar to that of MISO and SR2508. The partition coefficients in octanol/water of RP170, MISO, and SR2508 were 0.094, 0.35, and 0.021, respectively. The radiosensitizing activity of RP170 was similar to that of MISO and SR2508 in vitro and in vivo. There was no significant difference in the radiosensitizing activity of RP170 in vivo between intravenous and intraperitoneal administration. The acute toxicity of RP170 was the same as that of SR2508. Pharmacokinetic evaluation showed that the concentration of RP170 in the brain was as low as that of SR2508. RP170 is expected to have the same radiosensitizing effects as MISO and SR2508, and to be less neurotoxic than MISO.

Animals↗
PubMed1989

Suppression of contact sensitivity by local hyperthermia treatment due to reduced Langerhans cell population in mice.

The effects of local hyperthermia treatment on contact sensitivity (CS) and on the number of Langerhans cells (LCs) were studied in mice. CS was significantly suppressed when mice were sensitized in the hyperthermia treated skin I, 2 or 4 days after treatment (43 degrees C for 45 min). This suppressive effect was not observed 7 or 14 days after the treatment. CS was also suppressed when mice were sensitized in non-treated skin I day after the treatment. The density of LCs detected as ATPase-positive cells also decreased significantly 1, 2, 4 and 7 days after the treatment. There appeared to be a positive correlation between the number of LCs and the extent of CS when mice were sensitized at hyperthermia treated skin. It was observed that this suppressive effect on CS was dose- and temperature-dependent. It could be transferred by spleen cells from the hyperthermia treated and DNFB-sensitized donors, and was antigen specific when spleen cells were transferred before sensitization of the recipient mice. This indicated it was, in part, associated with the induction of suppressor cells. These findings suggest that local hyperthermia treatment reduces the number of LCs with subsequent suppression of the induction phase of delayed-type hypersensitivity by the generation of antigen-specific suppressor cells.

Animals↗
PubMed1989

Common acute lymphoblastic leukemia-associated antigen (CALLA)-positive B cell lymphoma.

We analyzed the expression of common acute lymphoblastic leukemia-associated antigen (CALLA) in 134 cases of non-Hodgkin's lymphoma of the B cell type using an immunohistochemical method. The incidence of CALLA expression in B cell lymphomas was higher in follicular lymphomas (29%) than in diffuse lymphomas (15%). Malignant lymphoma (ML), follicular small cleaved cell (FSC) according to the histologic type, showed a considerably high incidence of CALLA (43%), whereas ML, diffuse small cleaved cell (DSC) displayed a very low incidence (5%). These findings suggest the possibility that these two morphologically similar lymphomas may be derived from distinct populations of B cells [CALLA+-germinal center (GC) cells, CALLA- -germinal center (GC) cells or mantle zone (MZ) cells]. In addition, one case of DSC expressed surface immunoglobulin D (SIgD) and alkaline phosphatase (ALPase) as well as CALLA. This indicates that CALLA-positive small cleaved cell lymphoma expressing SIgD or ALPase may represent neoplastic proliferation of CALLA-positive MZ cells of secondary follicles in lymph nodes.

Antigens, Differentiation↗
PubMed1989

Clinical presentations of vascular malformations of the brain stem: comparison of angiographically positive and negative types.

Clinical and radiographic features of 63 patients with a vascular malformation of the brain stem are described. On radiological grounds they were divided into two groups: one with angiographically visible lesions (AVAVMs), the other with lesions not seen angiographically, that is, occult (AOVMs). In the first group the initial clinical manifestation was due to haemorrhage in 20 of the 33 cases and consisted of a progressive neurological deficit in 12. In the second group 29 of the 30 initially presented with a brain stem haemorrhage. The latter was often characterised by development of symptoms over two days or more (16 cases), absence of headache (48 cases) and tendency to recurrence (20 cases). Clinical diagnosis was difficult in many cases especially in the AOVM group. Several of the patients were misdiagnosed as having multiple sclerosis. Clinical data in conjunction with magnetic resonance imaging were helpful in determining the nature of these lesions.

Adult↗