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Biomedical subjects

A Murakami

Publications and source records attributed to A Murakami.

At least 469 records · Page 26Linked to original sources

Apoptosis after butyrate-induced differentiation in retinoblastoma cell line Y-79.

PURPOSE: To study the fate of Y-79 human retinoblastoma cells after induction of differentiation. METHODS: Y-79 cells were cultured in a synthetic medium and were induced to neuronal differentiation by butyrate treatment. Neurofilaments, p53, and DNA-synthesizing nuclei labeled with 5-bromodeoxyuridine were immunostained, and apoptotic cells were labeled by in situ DNA nick end labeling (TUNEL). We combined these immunostaining and labeling methods to determine whether the cells expressed these markers at the same time. DNA fragmentation and p53 levels were also determined by electrophoresis. RESULTS: Y-79 cells proliferated in the synthetic medium. After butyrate treatment, they extended protrusions and increased neurofilament immunoreactivity. The differentiated features were striking on day 7. Thereafter, differentiated cells decreased and apoptotic cells increased. DNA synthesis was detected in the cells expressing immunoreactivity for neurofilaments or p53. At day 7, most of the cells with p53-positive nuclei were alive and neurofilament-positive. However at day 10, the p53-positive cells were apoptotic and neurofilament-positive apoptotic cells accumulated. CONCLUSIONS: We conclude that the Y-79 cells express p53 and undergo apoptosis after neuronal differentiation. There could be a p53-dependent apoptotic pathway in butyrate-induced differentiated Y-79 cells due to the inability to regulate cell cycling.

Apoptosis↗

Apoptosis in retinal ganglion cell decrease in human glaucomatous eyes.

Hematoxylin-eosin staining, the TUNEL method for in situ detection of the intranuclear DNA fragmentation, which indicates apoptosis, and electron microscopy were used to study the morphologic changes in specimens from the eyes of 8 patients with secondary glaucoma and 2 normal control eyes to evaluate our hypothesis that apoptosis causes a decrease in retinal ganglion cells in human glaucomatous eyes. The TUNEL method permits identification of intranuclear DNA fragmentation. Apoptosis was found in the ganglion cells of 2 glaucomatous eyes with recent sight loss, and in the ganglion cells of a control eye from a 95-year-old subject, taken at autopsy. Results of our study indicate that a decrease in retinal ganglion cells in glaucomatous eyes is caused by apoptosis. In addition, apoptosis resulting from aging must be considered in order to understand the reduction of retinal ganglion cells in the glaucomatous eyes of elderly patients.

Adult↗

Mast cells in pterygium: number and phenotype.

PURPOSE: To investigate the pathogenesis of pterygium. METHODS: The number and phenotype of mast cells were examined in excised tissue from 35 pterygia patients and compared with those in normal conjunctival specimens obtained during cataract or other intraocular surgery. RESULTS: Toluidine blue staining showed that the mean number of mast cells in the pterygia specimens was twice as high as that in the normal conjunctival tissues. Immunohistochemistry with a primary antibody to tryptase, specific for mast cells, also revealed a twofold increase in the mast cell number in the pterygia specimens compared with the normal conjunctival tissues. In the pterygia, more than 94% of the tryptase-positive mast cells were found to express chymase and c-kit. Almost all mast cells in the pterygia were tryptase-positive, chymase-positive mast cells (MC(TC)S). There was no phenotypic difference between the mast cells in the pterygia and those in the normal conjunctival tissues. CONCLUSIONS: The MC(TC)S appear not to be immune system-related and to have functions in angiogenesis and tissue remodeling. The increase in the number of mast cells caused by nonallergic stimulation may contribute to the pathogenesis of pterygium.

Antibodies, Monoclonal↗

Expression of stem cell factor in pterygium.

PURPOSE: To investigate the possible role of stem cell factor (SCF) in the pathogenesis of pterygium. METHODS: The localization of SCF was examined immunohistochemically in excised tissue from 4 primary pterygia and 5 normal conjunctival specimens. RESULTS: Three of the four pterygia showed strong immunoreactivity of SCF in the subepithelial connective tissue at the cap area. This immunoreactivity was completely blocked by using a primary antibody preincubated with recombinant SCF. The SCF-positive cells were identified as a population of fibroblasts by immunostaining for vimentin and prolyl 4-hydroxylase in adjacent sections. No apparent immunoreactivity of SCF was observed in the subepithelial connective tissues in the head and body of the pterygia and in the normal conjunctiva. CONCLUSION: Stem cell factor is overexpressed in fibroblasts at the cap area of most pterygia.

Antibodies, Monoclonal↗

Treatment of PCB-contaminated soil in a pilot-scale continuous decomposition system.

The BCDP (Base Catalyzed Decomposition Process) is a process by which difficult-to-decompose organic chlorine compounds, such as PCBs, are chemically decomposed and dechlorinated. Pilot-plant tests for PCB contaminated soil were carried out. PCB contaminated soil (32 mg/kg-530 mg/kg) was decontaminated to a level (0.038 mg/kg-4.8 mg/kg) which satisfied the corresponding Japanese environmental standard which stipulates, "there must be no discharge of PCB containing leachate".

Environmental Pollution↗

Control of ribonucleic acid function by oligonucleoside methylphosphonates.

Oligodeoxyribonucleoside methylphosphonates contain nonionic 3'-5' linked methylphosphonate internucleotide bonds in place of the normal charged phosphodiester linkage of natural nucleic acids. These oligomers are resistant to nuclease hydrolysis, can pass through the membranes of mammalian cells in culture and can form stable hydrogen-bonded complexes with complementary nucleotide sequences of cellular RNAs such as mRNA. The oligomers are readily synthesized on insoluble polymer supports. Their chainlength and nucleotide sequence can be determined by chemical sequencing procedures. Oligonucleoside methylphosphonates which are complementary to the 5'-end, initiation codon region, or coding region of rabbit globin mRNA inhibit translation of the mRNA in rabbit reticulocyte lysates and globin synthesis in rabbit reticulocytes. This inhibition is due to the interaction of the oligomers with mRNA and the extent of inhibition is influenced by the secondary structure of the mRNA and the location of oligomer binding site on the mRNA. Oligomers complementary to the initiation codon regions of N, NS and G protein mRNAs of Vesicular stomatitis virus (VSV) inhibit virus protein synthesis in VSV-infected Mouse L-cells. These oligomers do not affect L-cell protein synthesis or growth. Virus protein synthesis and growth can also be selectively inhibited by oligonucleoside methylphosphonates which are complementary to the donor or acceptor splice junctions of virus pre mRNA. An oligomer complementary to the donor splice junction of SV40 large T antigen mRNA inhibits T-antigen synthesis in SV40-infected African green monkey kidney cells but does not inhibit overall cellular protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Spontaneous recovery after experimental manipulation of the plane of beat in sperm flagella.

It is generally accepted that the oscillatory beating characteristic of sperm flagella is the result of an ATP-induced sliding between the doublet microtubules of the flagellar axoneme, with these longitudinal forces being converted into a lateral bending moment by resistive components of the structure that limit the displacement. However, little is known about the mechanisms that regulate this sliding among the nine doublets of the cylindrical axoneme to produce the coordinated planar bending waves required for efficient sperm propulsion. We have investigated these mechanisms with a new procedure in which the sperm head is held in the tip of a vibrating micropipette. Data obtained by gradually rotating the plane of imposed vibration around the sperm axis indicate that the pattern of active sliding between the outer doublet tubules can rotate relative to the sperm head, and suggest that this active sliding is regulated in part by the central tubule complex.

Animals↗

Hereditary dilated cardiomyopathy in Holstein-Friesian cattle in Japan: association with hereditary myopathy of the diaphragmatic muscles.

This report deals with the pathology and genetic basis of dilated cardiomyopathy in 10 Holstein-Friesian cows aged 3-6 years, a disease similar to that reported in Simmental-Red Holstein and Holstein-Friesian cattle in several other countries. The main clinical signs were associated with systemic circulatory failure, and at necropsy the animals showed cardiomegaly, severe congestion and fibrosis of the liver, and systemic cardiac oedema. Histologically, hypertrophy and vacuolation of the cardiac muscle fibres and severe fibrosis were noted. Electron microscopically, the sarcoplasm of the hypertrophic fibres was seen to be filled with fine structures of low electron-density, together with thin filamentous material, suggesting myofibrillar lysis. The mitochondria showed increased size, an abnormal cristae pattern and vacuolation due to partial loss of cristae. Pedigree analysis of the affected cattle indicated an autosomal recessive mode of inheritance. The family line of this cardiomyopathy overlapped with that of hereditary myopathy of the diaphragmatic muscles in Holstein-Friesian cattle, the pathological aspects and inheritance mode of which were reported previously. The available evidence suggested a genetic association between these two pathologically distinct diseases.

Animals↗

Preparation of stereoregulated antisense oligodeoxyribonucleoside phosphorothioate and interaction with its complementary DNA and RNA.

Diastereoisomeric specificity of oligodeoxyribonucleoside phosphorothioate (OPT) in DNA/OPT and RNA/OPT hybrid formation was investigated. The difference in the configuration between RRRR and SSSS was reflected in the conformation and the stability of the DNA/OPT and RNA/OPT hybrids. Therefore, findings of this report rationalize the antisense effect by non-stereoregulated OPT and the difference of diastereoisomerism in susceptibility to RNase H.

Circular Dichroism↗

A congenic line of the DDD mouse strain, DDD/1-Mtv-2/Mtv-2: establishment and mammary tumorigenesis.

A single dominant gene on chromosome 18, Mtv-2, controls both the early appearance of mammary tumors and expression of mouse mammary tumor virus (MMTV) in the milk. A congenic DDD mouse strain, DDD/1-Mtv-2/Mtv-2 (DDD-Mtv-2), was developed by introducing this gene from GRS/AJms (GR) into DDD/1 mice by repeating 12 backcrosses and subsequent inbreeding using mammary tumors as a marker for selection. Southern blot analysis of the liver DNA from the resulting congenic mice with EcoRI and MMTV-U3 prove revealed that two DNA fragments corresponding to Mtv-2 were specifically transferred from GR to congenic mice. Detection of MMTV-gp52 antigen in the mammary gland and mammary tumor development in DDDfDDD-Mtv-2 mice demonstrated the production of infectious mature MMTV by Mtv-2 in congenic mice. About 80% of breeding DDD-Mtv-2 females developed mammary tumors in the course of one-year follow-up. The tumor incidence was lower and the tumor age higher than those in GR mice, suggesting less active functioning of the gene on the DDD genetic background. About 70% of these tumors were morphologically classified as pale cell and type P carcinomas peculiar to GR mice. The gene seemed to control the histologic features of mammary tumors. Congenic mice carried an MMTV provirus in an incomplete form on Y chromosome. The DDD-Mtv-2-strain will provide a new model for biological and molecular researches into mouse mammary tumorigenesis.

Animals↗

Primary hypertrophic pyloric stenosis in the adult.

A case is reported of a 55 year old male patient with primary hypertrophic pyloric stenosis who was subjected to distal gastrectomy. Adult hypertrophic pyloric stenosis is an uncommon condition which is usually misdiagnosed as carcinoma of the antrum. It is a benign disease resulting from hypertrophy of the circular fibres of the pyloric canal and is recognizable radiologically by narrowing and elongation of the pyloric canal and endoscopically by appearances resembling those of the cervix. This condition is probably congenital although aetiology has not been established. In the absence of symptoms, no clinical treatment is required. However, surgical intervention is advocated, when stenosis gives rise to symptoms, there is a suspicion of malignancy, or the ulceration due to the disease. Distal gastrectomy with gastroduodenostomy is the treatment of choice.

Diagnostic Errors↗

Specific detection and quantitation of SCC antigen 1 and SCC antigen 2 mRNAs by fluorescence-based asymmetric semi-nested reverse transcription PCR.

Squamous cell carcinoma antigen (SCCA) is expressed in normal squamous epithelia and malignant squamous cell tissues. The serum level of SCCA has been used to evaluate treatment efficacy, clinical course of disease, and recurrence. SCCA is produced by at least two genes (SCCA1 and SCCA2); both of them have been located on chromosome 18q21.3. It has been difficult to examine the expression levels of SCCA1 and SCCA2 mRNAs separately because of their high homology at nucleotide level. In the present study, asymmetric semi-nested reverse transcription PCR, based on the principle of fluorescence energy transfer, enabled to quantitate the copy numbers of both SCCA1 and SCCA2 mRNAs. Using this method, the expression levels of these mRNAs were evaluated in normal and malignant squamous tissues. The copy number of SCCA2 mRNA was higher in malignant tissues than in normal tissues, while those of SCCA1 mRNA did not significantly differ between normal and malignant tissues. These data indicate that specific quantitation of the expression level of SCCA2 mRNA may be useful for the diagnosis and management of patients with squamous cell carcinoma.

Antigens, Neoplasm↗

1'-Acetoxychavicol acetate, a superoxide anion generation inhibitor, potently inhibits tumor promotion by 12-O-tetradecanoylphorbol-13-acetate in ICR mouse skin.

The anti-tumor-promoting activity of 1'-acetoxychavicol acetate (ACA) was examined in a two-stage carcinogenesis experiment in ICR mouse skin using 7,12-dimethylbenz[a]anthracene (0.19 mumol) and 12-O-tetradecanoylphorbol-13-acetate (TPA; 1.6 nmol). Topical application of ACA (160 nmol) markedly reduced the average number of tumors per mouse and the ratio of tumor-bearing mice: inhibition ratios 90% (p < 0.001) and 42% (p < 0.005), respectively. ACA even at a dose equimolar to TPA (1.6 nmol) significantly reduced the average number of tumors per mouse: inhibitory ratio 44% (p < 0.05). ACA potently inhibited TPA-induced superoxide (O2-) generation in differentiated HL-60 cells (IC50 = 4.3 microM) and suppressed the lipid hydroperoxide formation by 42% (p < 0.001) in the ethyl linoleate autoxidation test.

Animals↗

Attempt to induce total-body hyperthermia by whole-abdominal hyperthermia using a radiofrequency capacitive-heating system: an experimental study in dogs.

The effects of whole-abdominal hyperthermia (WAH), using an 8 MHz radiofrequency capacitive-heating system, on the intraperitoneal and extraperitoneal distribution of heat and on the functions of visceral organs were studied. Eight female mongrel dogs were divided into two groups. Five were infused and three were not infused intraperitoneally with physiological saline. The mean increase in systemic temperature during WAH was 6.4 degrees C for the saline-infused group and 5.1 degrees C for the non-infused group. The systemic temperature reached 40 degrees C about 50 min after the start of heating in four of five animals in the saline-infused group; three of the four animals died, and in these the maximum temperature of the liver exceeded 43.5 degrees C. The infusion of saline into the peritoneal cavity may facilitate the elevation of systemic temperature. The effects on the liver of WAH were very marked, as analysed by biochemical and histological techniques. Visceral organs tolerated heating to less than 43 degrees C by WAH alone. It appears that elevation of the systemic temperature to 40.5 degrees C or more can be safely achieved under conditions where the temperature in the peritoneal cavity is kept below 43.5 degrees C during WAH.

Abdomen↗

A biometrical study on esophageal invasion of carcinoma of the upper stomach. Part II: Radiographic evaluation of esophageal invasion on the basis of its occurring point and size.

Esophageal invasion of upper stomach cancer was analized on the resected specimen based on its occurring point and size. The distance of esophageal invasion was calculated by subtracting the distance between the occurring point and esophagogastric junction (EJG) from the radius of the cancer on the preoperative X-ray films. Fifty-six (76.7%) out of 73 resected cancers of the upper stomach invaded the esophagus. The average distance of invasion was 19.8 +/- 12.7 mm; the longest distance was 64.0 mm. The shorter was the distance of the occurring point from the EGJ, the longer was the esophageal invasion. The calculated distance of esophageal invasion of the cancer was correlated significantly with its histological distance (p less than 0.01). The distance of esophageal invasion can be seen with acceptable accuracy on the X-ray films preoperatively, even when the proximal edge of esophageal invasion is not clear on the films.

Adenocarcinoma↗

A biometrical study on esophageal invasion of carcinoma of the upper stomach. Part I: Determination of occurring point of the cancer and analysis of its horizontal extension.

In order to detect the occurring point of gastric cancer, and to determine its horizontal extension from this point, we performed a histological examination of 30 resected specimens of upper stomach cancer and 31 of middle and lower stomach cancers. The center of the horizontal extension (Oh) and that of the vertical extension (Ov) were calculated using a paper model. The mean distance between Ov and Oh (Ov-Oh D) was as little as 5.7 +/- 5.0 mm, and the ratio of Ov-Oh D to the size of the lesion was as low as 8.3 +/- 6.7%. There was a linear correlation between the oral and anal radii of the cancer. There was also a linear correlation between anterior and posterior radii of the cancer. In conclusion, either the Oh or the Ov can be considered as the occurring point, and the cancer grows concentrically around this point.

Adenocarcinoma↗