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Biomedical subjects

Y Lin

Publications and source records attributed to Y Lin.

At least 685 records · Page 38Linked to original sources
PubMed1984

Induction of interleukin 2 messenger RNA inhibited by cyclosporin A.

Cyclosporin A blocked production of the lymphokine interleukin 2 by activated T lymphocytes. In a human and a murine cell line this inhibition reflected an absence of interleukin 2 messenger RNA. Under conditions in which these cells are normally stimulated to secrete high levels of interleukin 2, they failed to do so in the presence of cyclosporin A. In both cell lines this failure was accompanied by an absence of interleukin 2 messenger accumulation.

Animals↗
PubMed1984

Winter flounder antifreeze proteins: a multigene family.

The nucleotide sequence of a cDNA clone of winter flounder antifreeze protein was determined by the dideoxynucleotide method. The sequence would predict a protein of 91 amino acids composed of a prepropeptide of 38 amino acids and a mature protein of 53 amino acids, which includes four complete 11-amino acid repeats. This predicted sequence corresponds to an antifreeze protein of intermediate size which is one 11-amino acid repeat longer than the smallest antifreeze proteins found in the serum of winter flounder during the cold season. Southern blot hybridization analysis of winter flounder genomic DNA with radioactive cDNA probes reveals a multigene family of potential antifreeze protein genes. This conclusion is supported by amino acid sequence analysis of several serum antifreeze proteins.

Amino Acid Sequence↗
PubMed1984

Ultrastructural changes of bone marrow megakaryocytes in several types of injury.

Seventy-one dogs were used in this study. Bone marrow tissues were examined by LM and EM and the peripheral blood platelets were counted. On the basis of previous research, megakaryocytophagia in bone marrow was confirmed. It was also proved that neutrophilic granulocytes participate in the autophagocytosis reaction in the body. Megakaryocytophagia plays a major role in the elimination of degenerate megakaryocytes in the marrow. The pathological change in megakaryocytes is considered to be one of the important causes of decrease in number and impairment of function of the platelets in burn, blast injury and burn-blast combined injury.

Animals↗
PubMed1983

Passive smoking and lung cancer.

Questions about the smoking habits of parents and spouses were asked in a case-control study involving 1338 lung cancer patients and 1393 comparison subjects in Louisiana, USA. Non-smokers married to heavy smokers had an increased risk of lung cancer, and so did subjects whose mothers smoked. There was no association between lung cancer risk and paternal smoking. The association with maternal smoking was found only in smokers and persisted after controlling for variables indicative of active smoking. It is not clear whether the results reflect a biological effect associated with maternal smoking or the inability to control adequately for confounding factors related to active smoking. This preliminary finding deserves further investigation.

Adenocarcinoma↗
PubMed1983

Synthesis of 3,6-bis(aminoalkoxy)acridines and their effect on the immune System.

A series of 3,6-bis(aminoalkoxy)acridines (2) was prepared and shown to have a protective antiviral effect against an interferon-sensitive virus (Columbia SK) and to partially restore an antibody response to a T-cell-dependent antigen in leukemic immunosuppressed mice. The presence of circulating interferon and the stimulation of natural killer cell activity in mice was observed for 21.

Acridines↗
PubMed1983

Induction of plasma protein secretion in a newly established human hepatoma cell line.

To study the expression and the regulation of hepatocyte markers, we have undertaken to establish human hepatoma cell lines of various phenotypes. We now report the establishment of a new human hepatoma cell line, HA22T/VGH. This cell line has many of the properties of human hepatocellular carcinoma. Only 5 of 15 plasma proteins investigated were detected in the medium of a 10-day-old HA22T/VGH culture. However, when the HA22T/VGH cells and a clonal derivative, C5, were cultured in an aggregated form, all 15 plasma proteins were found in the culture medium. These results indicate that hepatoma cell lines with different phenotypes can be established, and they provide a good experimental framework to investigate differentiation of human hepatocytes.

Animals↗
PubMed1983

An analysis of the sensitivity of somatic cell hybrids to natural killer cell- and natural cytotoxic cell-mediated lysis.

The analysis of the NK and NC sensitivity of somatic cell hybrids formed between parental cell lines that differ in their NK and NC sensitivity has shown the following. 1) The dominant expression of both NK and NC recognition determinants on target cells; 2) the dominant expression of two post-recognitive NC resistance mechanisms, one requiring protein synthesis and one being protein synthesis independent; and 3) the dominant expression of a post-recognitive NK resistance mechanism, which is protein synthesis independent. The post-recognitive protein synthesis-independent NC resistance mechanism confers no NK resistance and the post-recognitive NK resistance mechanism confers no NC resistance. Whether the post-recognitive protein synthesis-dependent NC resistance mechanism confers NK resistance remains open to question. The analysis of the hybrids indicates that transformed cells become sensitive to either NK- or NC-mediated lysis by losing their resistance to the lytic activity of these effector cells, and it appears that differentiation plays a role in determining whether NK or NC resistance will be lost upon transformation. A model is proposed in which the differentiation into a fibroblast associates the loss of NC resistance with transformation, whereas the differentiation into a lymphocyte associates the loss of NK resistance with transformation. Because the loss of NK resistance is not associated with the transformation of fibroblasts, they remain NK resistant, and because the transformation of lymphocytes is not associated with the loss of NC resistance, they remain NC resistant. This provides the basis for the target specificity exhibited by NK and NC effectors.

Animals↗
PubMed1983

Synthesis of delta sleep-inducing peptide (DSIP) and its physiological activity.

Protected nonapeptide--Delta Sleep-Inducing Peptide (DSIP) formula: see text has been synthesized by classical method. The product has been treated with TFA and purified on DEAE-Sephadex-A25 column, pure free nonapeptide obtained and alpha to beta transposition of Asp-residue found to be absent. It has been assayed by electrophoresis at pH 3.8, microcrystallinecellulose TLC and HPLC. The physiological activities of synthetic DSIP are performed on rabbits by using intravenous administration or mesodiencephalic ventricular infusion. Its function of intensifying delta and sigma waves on rabbit's electroencephalogram (EEG) is evident. There is no concomitant increase of delta- and sigma-enhancing effect following mesodiencephalic ventricular infusion of 10 or 20 times higher than 5 microgram/rabbit doses. Results of 6-day consecutive intravenous administration (50 microgram/kg) indicate that there is no obvious sign of adaptation to DSIP. Results suggest that the physiological function of endogenous sleep-inducing peptide is different from that of general sleeping draught.

Animals↗
PubMed1982

Synthesis of biologically active interleukin 2 by Xenopus oocytes in response to poly(A)-RNA from a gibbon T-cell line.

The poly(A)-containing RNA isolated from a gibbon lymphosarcoma cell line, MLA144, known to release Interleukin 2 (IL2) was microinjected into Xenopus oocytes. The incubation medium from injected oocytes stimulated the DNA synthesis of an IL2-dependent cell culture and also maintained its viability. DNA-stimulating activity appeared in the oocyte incubation medium 6 h after injection and continued to accumulate for at least 96 h. Thymidine incorporation by the IL2-dependent cells is proportional to the concentration of oocyte incubation medium added and the IL2 activity produced by the oocytes is proportional to the amount of poly(A)-RNA injected. Incubation medium of oocytes injected with RNA from another T-cell line, 6G1, which does not produce IL2, did not contain DNA-stimulating activity. The same assay also showed that the IL2 mRNA sedimented at 14-16 S in a nondenaturing sucrose gradient. A series of monoclonal antibodies prepared against human IL2 neutralized the DNA-stimulating activity released by the injected oocytes to the same extent as they neutralized human IL2.

Animals↗
PubMed1982

Antitumor agents. 2. Bisguanylhydrazones of anthracene-9,10-dicarboxaldehydes.

9,10-Anthracenedicarboxaldehyde bis[(4,5-dihydro-1H-imidazol-2-yl)hydrazone] (bisantrene, VI-1) showed anticancer activity in mice vs. both leukemias and solid tumors. Increases in life span vs. the following neoplasms were: P-388 leukemia, 137%; B-16 melanoma, 122%; Lieberman plasma cell tumor, greater than 85%; colon tumor 26, 150%; Ridgway osteogenic sarcoma, 85%. There were significant numbers of long-term survivors. Both DNA and RNA synthesis were strongly inhibited. The drug was resistant to biodegradation and was bound strongly to tissues; in monkeys the half-life for disappearance from serum was 6 days. Related hydrazones were synthesized, and structure-activity relationships are discussed. Two routes to ring-substituted anthracene-9,10-dicarboxaldehyde intermediates were developed.

Animals↗
PubMed1982

[Acute preoperative hemodilution in radical hysterectomy for carcinoma of the uterine cervix (author's transl)].

With an attempt to diminish the post-transfusion hepatitis following radical hysterectomy, the study was made on 27 cases of cervical cancer undergone the operation. Fifty cases with blood transfusion immediately prior to the study was taken as control group. Under general anesthesia, 800 ml of venous blood was drawn from the peripheral vein under simultaneous infusion of 1,000 ml of Saviosol to maintain the circulating blood volume. The blood was returned after hemostatizing procedures. Of the study group, the blood loss, operation time, urinary output during the operation, and drainage amount were 960 g, 157 minutes, 350 ml and 160 ml respectively, while those of control group were 930 g, 164 minutes, 150 ml and 280 ml. The circulation status remained within normal limits, no bleeding tendency was appeared. Blood loss of the study group was estimated 960 g, however the actual blood loss calculated was on l6 719 g. There were no particular complication in the study group, while there was 12% of hepatitis among the control group. The advantages were concluded as 1) Patient was under normovolemic state when the operation started. 2) The blood transfused had normal O2 transport and hemostatic capacity. 3) The management of the patient was not so difficult and no special equipment and technique were needed.

Female↗
PubMed1981

Molecular cloning and characterization of winter flounder antifreeze cDNA.

Double-stranded cDNA was synthesized from partially purified winter flounder antifreeze mRNA and inserted into the endonuclease Pst I site of plasmid pBR322 by the poly(dG).poly(dC) homopolymer extension technique. The recombinant plasmids wee used to transform Escherichia coli. Clones containing antifreeze cDNA inserts were identified by the hybridization-selection technique. One of the inserts, 380 nucleotides in length, was digested with endonucleases Sau3AI and HinfI, which cleaved the insert into three fragments. The nucleotide sequences of these fragments were determined. The cDNA contains the entire coding sequence for a possible antifreeze peptide, including the leader sequence. The predicted amino acid sequence is similar to but not identical to one of the known sequences of antifreeze peptide. Within the cDNA are three segments of repeating sequences. The basic repeating sequence of 11 amino acids is maintained in the amino acid sequence coded by the cDNA and in the antifreeze peptide.

Amino Acid Sequence↗
PubMed1980

Purification and characterization of winter flounder antifreeze peptide messenger ribonucleic acid.

The serum of winter flounder contains a group of small antifreeze peptides which lower the freezing point of their body fluids during the winter months. The poly(A)-containing mRNA coding for these peptides has been isolated from livers of the winter specimens. When the isolated antifreeze mRNA was analyzed by a denaturing polyacrylamide gel electrophoresis, at least two distinct bands approximately 450 nucleotides in length are visible. In a wheat germ cell-free protein synthetic system these mRNAs direct the synthesis of small peptides which can be precipitated by antisera against purified winter flounder antifreeze peptides. Full-length cDNA was synthesized from the isolated antifreeze mRNA by avian myeloblastosis reverse transcriptase. From the RNA excess hybridization kinetic analysis, there are probably three different mRNAs coding for the antifreeze peptides. Using the radioactive cDNA probe, it was estimated that 1% of the total RNA in liver of a January specimen is antifreeze mRNA. RNA from a summar specimen showed no significant hybridization even at high concentrations of RNA. These results indicate that the control of antifreeze peptide biosynthesis relies at least in part on the synthesis or degradation of translatable mRNA.

Animals↗
PubMed1979

Environmental regulation of gene expression. In vitro translation of winter flounder antifreeze messenger RNA.

The serum of winter flounder contains a group of antifreeze peptides which lower the freezing point of their body fluid in the winter. These antifreeze peptides disappear from their serum in the summer when the water temperature rises. Messenger RNA isolated from the liver of flounder collected in January directs the synthesis of predominantly one protein in an in vitro protein synthesis system. This protein can be precipitated by the antiserum made from the purified antifreeze peptides and was identified as the precursor(s) of these peptides. There is a seasonal variation in the concentrations of mRNA coding for the antifreeze peptides in the liver which can be correlated with the appearance and disappearance of these peptides in the serum. However, the changes in the levels of mRNA occur much sooner than the changes in the levels of antifreeze peptides in the serum, suggesting that an additional control mechanism might have taken place at the translational level.

Animals↗
PubMed1978

Bisamidines of 2,6-diaminoanthraquinone as antiamebic agents.

A series of bisamidines of 2,6-diaminoanthraquinone was synthesized and tested against cecal and hepatic forms of Entamoeba histolytica infections in rats and hamsters, respectively. A number of compounds were found to have good activity against infections in both species.

Amebiasis↗
PubMed1978

Antitubercular 2,8-bis(alkylaminomethyl)phenazines.

The preparation and antitubercular properties of a series of 2,8-bis(alkylaminomethyl)phenazines are described. These compounds all inhibited the growth of Mycobacterium smegmatis ATCC 607 in vitro. 2,8-Bis(dibutylaminomethyl)phenazine (5c) was also active against a lethal Mycobacterium tuberculosis H37Rv infection in mice.

Animals↗