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Biomedical subjects

J S Oh

Publications and source records attributed to J S Oh.

27 records · Page 2Linked to original sources
PubMed1992

Clinical efficacy of topical homologous fibronectin in persistent corneal epithelial disorders.

The clinical efficacy was investigated of topical homologous fibronectin on persistent corneal epithelial defects of various etiologies. Fibronectin was purified from blood bank homologous plasma by gelatin-Sepharose 4B affinity chromatography. Twenty eight eyes of twenty five patients with persistent corneal epithelial defects and sterile corneal ulcers that failed to improve with standard therapy were treated by the instillation of homologous fibronectin eyedrops 5 times a day (500 micrograms/ml). Complete reepithelialization was achieved in all patients except two eyes due to uncontrolled glaucoma and the taking of steroids. The healing time tended to be different depending on the duration of persistent corneal epithelial defects and the severity of underlying diseases. The mean +/- standard deviation duration of epithelial defect was 68.18 +/- 77.80 days. Average healing time was 42.07 +/- 17.47 days. Ocular symptoms were relieved significantly and no side effects were observed. Over an average follow-up period of about 8 months, two cases of recurrences were noted. These results show that homologous fibronectin was also effective in patients with persistent corneal epithelial defects and corneal ulcers.

Administration, Topical↗
PubMed1990

Effect of snuff extract on the replication and synthesis of viral DNA and proteins in cells infected with herpes simplex virus.

The water-extractable component of snuff (snuff extract) inhibits the replication of herpes simplex virus (HSV) by suppressing the synthesis of viral DNA. This process probably causes HSV to be oncogenic. To further understand the mechanism of inhibitory action of snuff extract on HSV replication, the effect of snuff extract on the synthesis of viral DNA and proteins in type 1 HSV (HSV-1) infected cells was investigated. Snuff extract inhibited the synthesis of viral DNA and altered the production of certain classes of viral proteins. The syntheses of ICP4, a viral alpha-protein, and ICP8, a beta-protein, were not generally reduced by noncytotoxic concentrations of snuff extract (where ICP = infected cell polypeptide). However, snuff extracts significantly inhibited the production of ICP gC (glycoprotein C), a gamma 2-protein, and the inhibition was in a concentration-dependent fashion: the higher the concentration of snuff extracts, the greater the inhibition. Based on the fact that the production of alpha- and beta-proteins is absolutely necessary for and precedes the viral DNA synthesis and that viral gamma 2-proteins are mostly produced by the newly synthesized viral DNA, it is concluded that snuff extract inhibits HSV-1 DNA replication directly rather than indirectly via the alteration of viral protein synthesis.

Cell Line↗
PubMed1990

Topical fibronectin treatment in persistent corneal epithelial defects and corneal ulcers.

Topical fibronectin, autologous and homologous, was used to treat nine patients (eleven eyes) with persistent corneal epithelial defects and corneal ulcers that failed to improve with standard therapy. The fibronectin was purified from autologous and homologous plasma by gelatin-Sepharose 4B affinity chromatography and administered topically, 500 micrograms/ml five times a day, for three weeks. Complete or nearly complete reepithelialization was achieved in all patients regardless of the source of fibronectin, autologous or homologous. But healing times varied. The average healing time was 41.7 +/- 14.7 days (35.7 +/- 12.4 days for autologous, 50.8 +/- 14.4 days for homologous). Ocular symptoms were relieved significantly, and no side effects were observed. Over an average follow-up period of 5.2 months, no recurrences were noted. The results showed that homologous, as well as autologous, fibronectin was effective in patients with persistent corneal epithelial defects and corneal ulcers.

Administration, Topical↗
PubMed1989

Herpes simplex virus enhances the 7,12-dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis and amplification and overexpression of c-erb-B-1 proto-oncogene in hamster buccal pouch epithelium.

We studied the effects of herpes simplex virus type 1 (HSV-1) inoculation and topical 7,12-dimethylbenz[a]anthracene (DMBA) application, alone or in combination, on the carcinogenesis and on the amplification and expression of various cellular proto-oncogenes in hamster buccal pouch tissue. Topical DMBA treatment produced tumor formation in pouches, but HSV-1 inoculation, alone caused no neoplastic changes. In pouch tissues receiving both DMBA application and HSV-1 inoculation, the development of initial leukoplakia and tumor has hastened and enhanced in comparison with those receiving DMBA alone. Topical DMBA application to pouch tissue induced an amplification and an increase in the expression of cellular erb-B-1 (c-erb-B-1) proto-oncogene in the epithelial tissue, whereas repeated infection with HSV-1 alone did not. Topical DMBA combined with HSV-1 inoculation, however, resulted in greater amplification and expression of c-erb-B-1 proto-oncogene in the pouch epithelial tissue compared to the DMBA alone. These data indicate that HSV-1 inoculation significantly increases the carcinogenic activity of DMBA, in part, by probably enhancing DMBA-induced amplification and expression of c-erb-B-1 proto-oncogene in hamster buccal pouch tissue.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1989

Effect of smoked tobacco tar on the growth, cytolytic action, DNA synthesis, and gene expression of herpes simplex virus.

Previous experiments have shown that topical application of smoked tobacco tar condensate to HSV-infected oral mucosae of mice promotes neoplastic changes. Although HSV is an oncogenic virus, the virus must be inactivated and lose its cytolytic activity to be oncogenic in vitro and in vivo. Therefore, we investigated the effect of the water-extractable components of smoked tobacco tar condensate (smoked tobacco tar extract) on the growth, cytolytic activity, DNA synthesis, and gene expression of type 1 herpes simplex virus (HSV-1). Diluted tar extracts in tissue culture medium markedly inhibited the replication and cytolytic activity of HSV-1 in vitro. The smoked tobacco tar extract also notably inhibited the synthesis of viral DNA and late gene expression in a dose-dependent manner. The synthesis of alpha- and beta-classes of viral proteins was not affected by the extract. Therefore, it is probable that the smoked tobacco tar extract inhibits the synthesis of viral DNA directly rather than indirectly by depressing early gene expression.

Animals↗
PubMedDate not supplied

Insulin-like growth factor-1 inscribes a gene expression profile for angiogenic factors and cancer progression in breast epithelial cells.

Activation of the insulin-like growth factor-1 receptor (IGF-1R) by IGF-1 is associated with the risk and progression of many types of cancer, although despite this it remains unclear how activated IGF-1R contributes to cancer progression. In this study, gene expression changes elicited by IGF-1 were profiled in breast epithelial cells. We noted that many genes are functionally linked to cancer progression and angiogenesis. To validate some of the changes observed, the RNA and/or protein was confirmed for c-fos, cytochrome P450 1A1, cytochrome P450 1B1, interleukin-1 beta, fas ligand, vascular endothelial growth factor, and urokinase plasminogen activator. Nuclear proteins were also temporally monitored to address how gene expression changes were regulated. We found that IGF-1 stimulated the nuclear translocation of phosphorylated AKT, hypoxic-inducible factor-1 alpha, and phosphorylated cAMP-responsive element-binding protein, which correlated with temporal changes in gene expression. Next, the promoter regions of IGF-1-regulated genes were searched in silico. The promoters of genes that clustered together had similar regulatory regions. In summary, IGF-1 inscribes a gene expression profile relevant to cancer progression, and this study provides insight into the mechanism(s) whereby some of these changes occur.

Blotting, Western↗