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Biomedical subjects

M Hatanaka

Publications and source records attributed to M Hatanaka.

At least 343 records · Page 19Linked to original sources
PubMed1980

Insertion of muntjac gene segment into hamster cells by cell fusion.

Indian muntjac diploid cells that have only three pairs of easily discernible large chromosomes were fused with hamster cells deficient in hypoxanthine guanine phosphoribosyltransferase (HGPRT) using polyethylene glycol. Cells that survived in hypoxanthine-aminopterine-thymidine (HAT)-oubaine medium were analyzed. Hybrid cells containing both muntjac and hamster chromosomes in a given cell were not found. Instead, the cells had the same chromosomal sets as those of either parental muntjac or hamster cells. A clonal isolate that had the same chromosomal sets as those of parental hamster cells were analyzed in detail and showed the following characteristics: (1) portions of the survival curve in various concentrations of HAT medium were intermediate between those of parental cells; (2) expressions of both muntjac and hamster antigen(s) were detected by immunofluorescence staining; (3) the mobility of the enzyme HGPRT in gel electrophoresis differed from that of parental hamster or muntjac cells. These results indicate that the clonal isolate (AD202h) is a somatic cell hybrid of hamster and muntjac that contains chromosomal sets of hamster with an inserted segment of the muntjac genome, including HGPRT. The formation of such an unusual hybrid and a possible explanation of transfer of some gene segments in the hybrid cell in this system are discussed.

Animals↗
PubMed1980

Conserved sequence related to the 3'-terminal region of retrovirus RNA'S In normal cellular DNAs.

The nucleotide sequences related to the 3'-terminal protion of retrovirus genomic RNA have been detected in the DNA of animals, including humans. The DNA complementary to the 400 to 700 nucleotides from the 3'-terminal end of retrovirus RNA (cDNA3'), which contains the enriched conserved region, was hybridized with DNA from a variety of animal cells. Under the conditions of annealing in 0.72 M NaCl at 67 degrees C and hydroxyapatite chromatography at 55 degrees C, 20 to 50% of the radioactivity of the cDNA3' prepared from two retroviruses, a murine Rauscher virus (RLV) and a baboon virus (M7), annealed with normal cellular DNA of animals, including human tissue. The thermal denaturation profile revealed considerable mismatching between the duplex of the cDNA3' and human DNA, cDNA3' of retroviruses is most homologous to cellular DNA of the host species of origin and is less homologous to cellular DNA of species that are distant in the phylogeny of the host species. The conservation and evolution of nucleotide sequences related to the 3' end of retrovirus genomes in animal DNAs, including humans, suggest that the sequences may have important functions.

Animals↗
PubMed1980

Anterior communicating artery aneurysms with associated anomalies.

In 296 cases with a single aneurysm of the anterior communicating artery (ACoA), fenestration or the presence of more than two ACoA's was observed in 17 cases (5.7%), and abnormal vessels of ACoA origin, such as a median artery of the corpus callosum, were observed in 13 cases (4.4%). As more than one anomaly was found in some of these cases, anomalies of the ACoA were found in total of 26 cases (8.8%). This occurrence rate was no higher than that observed in other cerebral aneurysm cases and in the control cases, which were reported previously. There was no significant increase of hypoplasia of the A1 portion if the ACoA aneurysm was complicated by other arterial anomalies.

Corpus Callosum↗
PubMed1980

[Postoperative transient occlusion of internal carotid artery due to shift of the clip used for neck clipping of the huge left internal carotid aneurysm (author's transl)].

A 49-year-old female, having had suffered from a huge left internal carotid (IC) aneurysm and a right IC aneurysm, was treated surgically. The neck of huge aneurysm, was treated surgically. The neck of huge aneurysm was clipped with Sugita's spring clip after its body was dissected and the otherone was clipped simply. Right hemiparesis was seen postoperatively. And the angiograms, taken on the 4th postoperative day, showed not only an aneurysmal disappearance but also an occlusion of the left ICA which presumably due to shift of the spring clip to the direction of antero-lateral. Right hemiparesis disappeared, however, suddenly on the 40th postoperative day and reopening of the left ICA was confirmed angiographically despite the further shift of the clip. The possible genesis of the curious course in this case and the possible complications in the use of large aneurysmal clip was discussed.

Carotid Artery Diseases↗
PubMed1979

Tumorigenicity of Indian muntjac diploid cells by the proviral integration of sarcoma gene of a mouse retrovirus.

The transformed clonal isolates of Indian muntjac diploid cells by a mouse sarcoma virus, 43-2XV, were tested for tumorigenicity in athymic nude mice. In spite of the indistinguishable transformed morphology, the tumorigenicity exhibited four different patterns: (a) no tumor formation; (b) slowly growing regressive tumor formation; (c) rapidly growing regressive tumor formation; and (d) rapidly growing progressive tumor formation. This demonstrates that the same diploid host cells transformed by the same virus reveal variable patterns of tumorigenic expression and some transformed host cells lack the tumorigenicity entirely. The findings that there are at least two chromosomes and four recombinant sites assigned for the proviral integrations of the sarcoma gene into the Indian muntjac gene (M. Hatanaka, R. Klein, R. Kominami, T. Oikawa, H. Okabe, N. Tsuchida, E. C. Connors, and A. Carrano. Transformation of Indian muntjac diploid cells by the proviral integration of sarcoma gene of a mouse retrovirus. Manuscript in preparation.) lead us to propose a hypothesis that variable expressions of tumorigenicity under the neutral background of immune responses, may arise from variable integrations of the sarcoma gene into the host chromosome.

Animals↗
PubMed1979

An ultramicrochemical test for mycoplasmal contamination of cultured cells.

A sensitive ultramicrochemical enzyme test for mycoplasmal contamination of cultured cells, based on the determination of the activity of adenosine phosphorylase, is described. The test was performed by assaying the enzymatic conversion of [8-14C]adenine and ribose-1-phosphate to [8-14C]adenosine by incubating a plastic leaflet carrying a counted number of cells (1 to 10). These leaflets were isolated from the bottom of the same plastic film dish in which the cells were cultured for experimental or diagnostic purposes, e.g. prenatal diagnosis or inborn errors of metabolism. The present test should be several 1000-fold more sensitive than the originally reported enzymatic method because (a) the adenosine-phosphorylase reaction is measured in the nucleoside forming direction which is by far the most active; and (b) the assay is performed with the cells and not with the culture medium. The latter is of special importance for the detection of those low-grade contamination in which most of the mycoplasma particles are attached to cell membranes.

Cell Line↗
PubMed1979

Conserved region of mammalian retrovirus RNA.

The viral RNAs of various mammalian retroviruses contain highly conserved sequences close to their 3' ends. This was demonstrated by interviral molecular hybridization between fractionated viral complementary DNA (cDNA) and RNA. cDNA near the 3' end (cDNA(3')) from a rat virus (RPL strain) was fractionated by size and mixed with mouse virus RNA (Rauscher leukemia virus). No hybridization occurred with total cDNA (cDNA(total)), in agreement with previous results, but a cross-reacting sequence was found with the fractionated cDNA(3'). The sequences between 50 to 400 nucleotides from the 3' terminus of heteropolymeric RNA were most hybridizable. The rat viral cDNA(3') hybridized with mouse virus RNA more extensively than with RNA of remotely related retroviruses. The related viral sequence of the rodent viruses (mouse and rat) showed as much divergence in heteroduplex thermal denaturation profiles as did the unique sequence DNA of these two rodents. This suggests that over a period of time, rodent viruses have preserved a sequence with changes correlated to phylogenetic distance of hosts. The cross-reacting sequence of replication-competent retroviruses was conserved even in the genome of the replication-defective sarcoma virus and was also located in these genomes near the 3' end of 30S RNA. A fraction of RD114 cDNA(3'), corresponding to the conserved region, cross-hybridized extensively with RNA of a baboon endogenous virus (M7). Fractions of similar size prepared from cDNA(3') of MPMV, a primate type D virus, hybridized with M7 RNA to a lesser extent. Hybridization was not observed between Mason-Pfizer monkey virus and M7 if total cDNA's were incubated with viral RNAs. The degree of cross-reaction of the shared sequence appeared to be influenced by viral ancestral relatedness and host cell phylogenetic relationships. Thus, the strikingly high extent of cross-reaction at the conserved region between rodent viruses and simian sarcoma virus and between baboon virus and RD114 virus may reflect ancestral relatedness of the viruses. Slight cross-reaction at the site between type B and C viruses of rodents (mouse mammary tumor virus and RPL virus, 58-2T) or type C and D viruses of primates (M7, RD114, and Mason-Pfizer monkey virus) may have arisen at the conserved region through a mechanism that depends more on the phylogenetic relatedness of the host cells than on the viral type or origin. Determining the sequence of the conserved region may help elucidate this mechanism. The conserved sequences in retroviruses described here may be an important functional unit for the life cycle of many retroviruses.

Animals↗
PubMed1979

[Aneurysm surgery in the older patients (author's transl)].

A series of 9 patients over 70 years of age with saccular aneurysms, operated on by a direct surgery is reviewed in order to discuss the aneurysm surgery in the older patients. The median age of the patients was 74 years, and median interval from the hemorrhage to surgery was 18 days. Operative mortality was 11% and morbidity was 33%. Result of intracranial aneurysm surgery in the older patients depends on the surgical technique for the arteriosclerosis. 1. Treatment of the aneurysm neck must be abandoned when a severe arteriosclerosis exists around it. Subsequent to exposure of the whole aneurysm, a complete reinforcement of the aneurysm wall should be undertaken. 2. Especially gentle manipulation of the brain is necessary since small arteries are easily pulled out from the sclerotic artery. 3. The cerebral veins must be preserved as well as possible to avoid the venous congestion, which easily causes an intracerebral hematoma following brain retraction. 4. The frequency of pre and postoperative complications is high, but through vigorous care, they are kept under control. 5. It is best not to judge the surgical indication simply by the chronological age, but rather to consider the physical age including the laboratory findings. Therefore, other than cases of severe arteriosclerosis, the same principles for surgical indication in younger patients should be used for older patients.

Aged↗
PubMed1979

Vein graft bypass in treatment of giant aneurysm.

A case of giant internal carotid artery aneurysm which was successfully treated by trapping and internal decompression of the aneurysm is presented. Proximal vascular occlusion of the involved internal carotid artery and long vein bypass graft were performed under hypothermia. This is the first long vein bypass graft reported for the treatment of a giant aneurysm.

Adult↗
PubMed1978

Reiteration frequency of feline type C viral genomes in homologous and heterologous host cell DNA.

Differences in the multiplicity of proviral sequences of two feline endogenous viruses, RD-114 and FeLV, in homologous and heterologous host DNA were examined by viral cDNA hybridization using cellular DNA fractionated with respect to reiteration frequency. The endogenous proviral DNAs in cat cells were fractionated predominantly with intermediate-repeated sequences, while RD-114 proviral DNA in virus-infected human cells was fractionated together with unique-sequence DNA. These differences were consistent with the results of kinetic analysis using unfractionated DNA.

Animals↗
PubMed1978

Effects of hydroxyurea on murine type C virus-specific DNA synthesis in newly infected cells.

Cell transformation and replication of the Rauscher pseudotype of Moloney murine sarcoma virus in mouse embryo fibroblasts were inhibited by hydroxyurea within a critical time period of 30 to 90 min postinfection. In cells infected by Rauscher leukemia virus, treatment with 1mM hydroxyurea during the critical time period resulted in the accumulation of minus-strand DNA (molecular weight, 3 x 10(6)) in association with the parental viral genoma RNA. This 5 to 6 x 10(6) dalton RNA:DNA hybrid was found in the cytoplasm. Positive-strand DNA of genomic or smaller size was not detected in the presence of hydroxyurea, but virus-specific DNA was found in the nucleus 30 min after removal of drug.

Cell Transformation, Neoplastic↗
PubMed1978

[Anterior communicating artery aneurysms accompanied with anomalies or anterior communicating artery (author's transl) ].

The investigation was carried out on arterial anomalies complicated with 296 cases of single aneurysm of anterior communicating artery and on the etiological significance of the anomalies in the development of cerebral aneurysms. Either the fenestration in anterior communicating artery or the presence of more than 2 anterior communicating arteries was observed in 17 cases (5.7%). As the anomaly was duplicated in some of these cases, the total number of cases with anomalies of anterior communicating artery became to be 26 cases (8.8%) out of 296 cases investigated. This occurrence rate was not higher than those observed in other cerebral aneurysmal cases and the control cases, which were reported previously. There was no significant difference as to the occurrence rate of hypoplasia of the A1 portion between the cases whose aneurysms of anterior communicating artery were complicated with arterial anomalies and the cases without the arterial anomalies.

Circle of Willis↗