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Biomedical subjects

M Abe

Publications and source records attributed to M Abe.

At least 901 records · Page 50Linked to original sources
PubMed1991

Evaluation of a new 2-nitroimidazole nucleoside analogue, RK-28 as a radiosensitizer for clinical use.

The experimental data previously reported on RK-28, a hypoxic cell sensitizer which is now being tested in a phase I clinical trial, are confusing. Some data indicate superiority of RK-28 over misonidazole (MISO), whereas others do not. This paper presents our experimental data on the efficacy, toxicity, and pharmacokinetics of RK-28, in comparison with those of MISO, and also summarizes the data of other investigators. In our experiments, RK-28 had a 1.5-2.5 times higher sensitizing activity in vitro on EMT6 and SCCVII cells than MISO, and the difference was larger when the pre-irradiation incubation time was longer. The latter was considered to be due to the time-dependent cellular uptake and reactivity of RK-28 with non-protein sulphydryls. In vivo, RK-28 was almost as efficient as or slightly inferior to MISO against SCCVII and EMT6 tumours when assayed with an in vivo/in vitro assay and a growth delay time assay. The LD50/7 by a single injection of RK-28 was half that of MISO, but when 60% of LD50/7 was injected into mice every day, the total dose that could be given was higher for RK-28 than for MISO. Pharmacokinetic studies using mice, rats, rabbits, and a dog showed that RK-28 was rapidly eliminated from the blood and various tissues. From our results it was concluded that the possible success of the clinical trial of RK-28 depends on its low cumulative toxicity.

Animals↗
PubMed1991

V(D)J recombinase activity in primary and secondary murine lymphoid organs: assessment by a PCR assay with extrachromosomal plasmids.

We developed a highly specific and sensitive polymerase chain reaction (PCR) assay to measure V(D)J recombinase activity using extrachromosomal plasmids and PCR. Extrachromosomal plasmids were prepared by eukaryotic replication origin, and a combination of the DQ52 and JH2 regions of the murine IgH gene, or of the D beta 2-1 and J beta 2.6 regions of the murine TCR beta gene, both with recombination signal sequences. Plasmids, transfected into cells to be examined and recovered after 48 h, were processed to detect recombined molecules by PCR with primers for the expected sequences produced by the precise signal joint. The PCR assay, when compared with a Camr assay that we prepared with the DQ52 and JH2 regions of the murine IgH gene, seems to have the following advantages. It detects only the recombined products produced by V(D)J recombinase activity and is therefore highly specific. It detects V(D)J recombinase activity in cells, including those with low replication frequency, which our Camr assay failed to do. This also enables detection of the recombinase activity not only in murine cell lines, but also in cells of murine lymphoid organs. The assay detects V(D)J recombinase activity in cell lines of human origin by replacing the eukaryotic replication origin of plasmids. High V(D)J recombinase activity was detected in bone marrow cells followed by thymic cells, and apparently lower activity was detected in cells of the lymph node and spleen of normal mice.

Animals↗
PubMed1991

Ossifying fibroma in the sylvian fissure: case report.

A rare case of an ossifying fibroma that developed in the sylvian fissure is reported here. During surgery, branches of the middle cerebral artery were encased in osseous tumor. The encased branches were divided and reanastomosed after the mass was removed. Postoperative angiograms demonstrated patency of the anastomosed arteries and a postoperative magnetic resonance imaging scan revealed no infarction distal to the arterial anastomoses. The authors recommend division and anastomosis of the encased arteries rather than partial removal of tumor from around the encased arteries, resulting in residual tumor being left behind.

Adult↗
PubMed1991

Effects of tumor necrosis factor and hyperthermia on Meth-A tumors.

The combined effects of purified human natural tumor necrosis factor (TNF) and hyperthermia were investigated in a transplanted TNF-sensitive Meth-A tumor model. We assessed the sequence and interval for the two treatments, the temperature that caused maximal heat sensitization, and the effects of pH modification on this combination therapy. Tumor response was evaluated by means of a tumor growth delay assay. TNF at a dose of 50 JRU/g caused significant tumor growth delay. A synergistic effect of TNF and hyperthermia was observed when TNF was administered 10 min before heating. This thermal enhancement of the action of TNF became more prominent with an increase in the heating temperature. Tumor growth delay was maximal when TNF was given immediately before or after hyperthermia. However, after an increase in the time interval to more than 2 h, there was no enhancement of growth delay. Injection of glucose (5 g/kg) caused a significant fall in pH at 10 and 30 min after administration. Further enhancement in tumor growth delay was seen with the trimodality of glucose, TNF, and heat compared to combined treatment with heat and either TNF or glucose at a hyperthermia of 42 degrees C. This effect was not obtained with heating to 40 degrees C. TNF appears to be a potent heat sensitizer when an appropriate temperature and time interval between hyperthermia and TNF administration are used. Trimodality treatment with hyperthermia, TNF, and glucose may be a new method of anticancer therapy.

Animals↗
PubMed1991

Duodenal glands of the pony (Equus caballus).

The ultrastructure and histochemistry of the duodenal glands of the pony (Equus caballus) was examined in four horses. Unlike that of most species except for the rabbit, the submucous glands of the horse contain two distinct cell types, serous and mucous. These cells are described.

Animals↗
PubMed1991

A novel monoclonal antibody specific for human pre-B cell leukemia/lymphoma.

A novel monoclonal antibody, designated WH14-antibody (WH14-Ab), was produced by using a non-T ALL cell line (HBL-3) as an immunogen. 35S-labelled immunoprecipitate revealed that the antigen reacting with WH14-Ab was estimated to be 30 Kd. Immunoglobulin isotype of WH14-Ab was IgG1. In the normal hematopoietic tissue, WH14-Ab reacted with a small number of monocytes (less than 30%) in the peripheral blood, but neither with the lymphocytes nor granulocytes. WH14-Ab reacted with HBL-3 and REH, but not with other B-cell leukemia/lymphoma and EBV-transformed cell lines. In addition, WH14-Ab reacted with most non-T ALL and pre-B lymphoblastic lymphoma. WH14-Ab did not react with all T-cell lymphomas. These findings indicate that the WH14-Ab may recognize the cell surface determinant shared by immature B cells, especially pre-B cells, in the B-cell lineage. WH14-Ab may be useful not only for the detection of pre-B cell leukemia/lymphomas but also for the investigation of maturation and differentiation of B-cell lineage.

Animals↗
PubMed1991

Statistical analysis of bilingual speaker's speech for cross-language voice conversion.

The goal of cross-language voice conversion is to preserve the speech characteristics of one speaker when that speaker's speech is translated and used to synthesize speech in another language. In this paper, two preliminary studies, i.e., a statistical analysis of spectrum differences in different languages and the first attempt at a cross-language voice conversion, are reported. Speech uttered by a bilingual speaker is analyzed to examine spectrum difference between English and Japanese. Experimental results are (1) the codebook size for mixed speech from English and Japanese should be almost twice the codebook size of either English or Japanese; (2) although many code vectors occurred in both English and Japanese, some have a tendency to predominate in one language or the other; (3) code vectors that predominantly occurred in English are contained in the phonemes /r/, /ae/, /f/, /s/, and code vectors that predominantly occurred in Japanese are contained in /i/, /u/, /N/; and (4) judged from listening tests, listeners cannot reliably indicate the distinction between English speech decoded by a Japanese codebook and English speech decoded by an English codebook. A voice conversion algorithm based on codebook mapping was applied to cross-language voice conversion, and its performance was somewhat less effective than for voice conversion in the same language.

Algorithms↗
PubMed1991

Quantitative assessment of quality of digitized portal images: receiver operating characteristic analysis applied to imaging in radiation therapy.

An objective and quantitative method for the evaluation of the quality of megavoltage portal images was developed by applying receiver operating characteristic analysis. On the basis of therapeutic use of portal images, setup errors were employed as "signals" in this experimental study that compared the original portal films with digitized images. Six readers observed 104 portal images of a chest phantom, half of which were "abnormal" (ie, had setup errors). Digital images (2,048 x 2,048 matrix) were enhanced by means of histogram equalization and then printed with a laser printer for observation. The readers showed a higher discrimination capacity with the digitally enhanced images, although a statistically significant improvement was not demonstrated. The present method of assessment of image quality proved to be both simple and clinically reasonable.

Humans↗
PubMed1991

Ultrastructure of the red pulp in spleen innervation in horse and pig.

The innervation of the red pulp in the spleen of horse and pig was investigated by electron microscopy. In addition, the neurilemma was studied by immunohistochemistry specific for S-100 protein. In the pig, a large population of smooth-muscle cells extending from the smooth-muscle trabeculae was present in the red pulp. The cytoplasmic processes of reticular cells enwrapped the smooth-muscle cells, and nerve fibres were distributed between the smooth-muscle cells and the reticular cells. The nerve terminals clustered toward the facing of the smooth-muscle cells. Nerve fibres and terminals were not disclosed within the sheathed artery. Immunohistochemically the neurilemma showed a reaction positive for S-100 protein. In the horse, no smooth-muscle cells were noted in the red pulp. The nerve fibres terminated around the cytoplasmic processes of the reticular cells. Nerve fibres and terminals were disclosed within the sheathed artery, and the terminals contained both large and small dense-cored vesicles. Immunohistochemically the neurilemma showed a reaction negative for S-100 protein. These findings support the presence of the axon-bearing reticular cells described earlier in the horse spleen.

Animals↗
PubMed1991

Neuroepithelial cyst presenting as recurrent aseptic meningitis.

A 41-year-old man had three episodes of acute aseptic meningitis from the age of thirty-six. With each episode he had severe occipital headache associated with a mononuclear pleocytosis and an increase in CSF protein. He had a neuroepithelial cyst originating from the choroid plexus of the right cerebellomedullary cistern. Spontaneous ruptures of the cyst probably caused recurrent chemical meningitis. A neuroepithelial cyst must be considered in the differential diagnosis of intracranial cystic tumors presenting with aseptic meningitis.

Adult↗
PubMed1991

Carbohydrate histochemistry of bovine duodenal glands.

The complex carbohydrates in the bovine duodenal glands were examined histochemically using 5 peroxidase-labeled lectins to achieve a better knowledge of their glycoprotein profiles. The presence of at least 2 different cell types and secretion of neutral mucin were observed in the bovine duodenal glands. The duodenal gland cells located in the central area of the lobules contained neutral glycoproteins with different saccharide residues as beta-D-gal-(1-3)-D-galNAc, alpha-D-galNAc, beta-(1-4)-D-glcNAc, NeuNAc and D-galNAc. The other cell types located in the peripheral area of the lobules contained alpha-L-Fuc, alpha-D-galNAc, beta-(1-4)-D-glcNAc, NeuNAc and D-galNAc. These findings seemed to be characteristic of a unique digestive process of the ruminant.

Animals↗
PubMed1991

Establishment of an estrogen receptor-positive cell line (HMA-1) derived from human breast carcinoma.

We have established a novel human breast carcinoma cell line, HMA-1, derived from ascites of a female breast cancer patient. HMA-1 was shown to be an epithelial cell line with intracytoplasmic duct-like vacuoles, microvilli, desmosomes and tonofibrils in accordance with human breast cancer. The cell line demonstrated a good cell growth ability in monolayer fashion with a doubling time of 46 hr. Based on a whole cell binding assay the cell line contained estrogen receptor (1.45 x 10(-4) sites/cell). Tamoxifen, an anti-estrogen agent induced a dose-dependent decrease in the cell growth rate, but estradiol stimulated the cell growth. HMA-1 could be transplanted subcutaneously into BALB/c nude mice, and was able to cause tumors approximately two months after heteroinoculation. These results indicate that HMA-1 cell line may serve as a new human breast carcinoma cell line which could be utilized in the breast cancer research.

Adenocarcinoma↗