R. Pottathil | Florida International University (original) (raw)
Papers by R. Pottathil
Cancer Research, 1977
We describe the antitumor effects of a certain RNA(s) isolated from murine tumors and embryos. A ... more We describe the antitumor effects of a certain RNA(s) isolated from murine tumors and embryos. A single i.v. injected of 10 to 30 microgram of this RNA(s) induces necrosis, hemorrhages, and regression of solid tumors in the strain of origin; in pregnant mice it is embryotoxic, causing resorption of the embryos, but has no toxic effect upon the tumor-bearing or pregnant host. Its action is highly specific, and its presence in both tumors and embryos suggests that it may result from reexpression of embryonic genes in tumor cells.
ABSTRACT-Pregnant rabbits of two partially inbred strains. WH/J and IIIVO/J. were given ten conse... more ABSTRACT-Pregnant rabbits of two partially inbred strains. WH/J and IIIVO/J. were given ten consecutive daily ip injections of 10 mg N-ethyl-N-nitrosourea (ENU)/kg dissolved In trioctanoin starting on either day 10. 15. or 18 of gestation. Of 7 WH/J progeny weaned. 3 developed primary renal tumors at 6.8±0.6 months of age (mean ± SE). Similarly. of 12 IIiVO/J progeny weaned. 10 developed primary renal tumors at 6.3±0.6 months of age (mean ± SE); in addition. 1 fibroblastic osteosarcoma and 5 neurofibromas. some associated with neurilemma cysts. were observed. Renal tumors were nephroblastomas. which appeared to develop within small renal cortical cysts. The frequency of tumor induction for each strain was similar to that in our previous experiments with acute administration of ENU and ethyl-urea plus NaN0 2 • but the latency period (6.4±0.5 mol was almost doubled. In addition. chronic treatment of ENU induced terato-
Texas reports on biology and medicine, 1981
Journal of Biological Chemistry
Journal of immunology (Baltimore, Md. : 1950), 1985
Human cytomegalovirus contains approximately 30 to 35 structural polypeptides. Although antibodie... more Human cytomegalovirus contains approximately 30 to 35 structural polypeptides. Although antibodies to several of these proteins are made during natural infection, their relationship to T cell recognition of this virus and subsequent control of infection is poorly understood. We have purified one of these proteins (HCMVgp64) that is found in abundance in infected cell lysates in order to delineate the relationship of single viral proteins to the immune response caused by the virus. HCMVgp64 induced T cell reactivity only in individuals with serologic evidence of past infection. In addition, HCMVgp64 elicited similar in vitro immune reactions as the whole virus including T cell proliferation, interleukin 2 production, and receptor expression as well as interferon production. These studies suggest that single proteins of HCMV such as HCMVgp64 are capable of inducing T cell responses and may be important in the development of immune reactivity to HCMV.
Proceedings of the National Academy of Sciences, 1988
Genome Research, 1992
To simplify our procedure for blood sample processing for PCR, we introduced a simpler, shorter, ... more To simplify our procedure for blood sample processing for PCR, we introduced a simpler, shorter, and more cost-effective method for the separation of peripheral blood lymphocytes (PBL) and DNA extraction for amplification with Taq polymerase. By this method, blood samples are processed in two simple 15-min steps: (1) separation of PBLs from whole blood by red blood cell lysis with the Roche Specimen Washing Solution, and (2) DNA extraction by heat-detergent treatment of separated PBLs. This new method is simpler than the standard Ficoll-Hypaque method for PBLs separation and Proteinase K digestion for DNA extraction. It is not inhibitory to DNA amplification and it allows effective processing of blood samples even after prolonged storage (as long as 8 days) at room temperature.
Biochemical and Biophysical Research Communications, 1981
... ACYL CHAINS OF PHOSPHOLIPIDS INDUCED BY INTERFERON IN MOUSE SARCOMA S180 CELLS Kuttikkatt Cha... more ... ACYL CHAINS OF PHOSPHOLIPIDS INDUCED BY INTERFERON IN MOUSE SARCOMA S180 CELLS Kuttikkatt Chandrabose and Pedro Cuatrecasas Department ... Pfeffer, LM, Wang, E.,Landsberger, FR, and Tamm, E. (1980) Methods in Enzymology, Interferons ed. S. Pestka ...
Biochemical and Biophysical Research Communications, 1985
Analytical Biochemistry, 1987
Diagnostic reagents for detection of human immunodeficiency virus (HIV) exposure with improved re... more Diagnostic reagents for detection of human immunodeficiency virus (HIV) exposure with improved reliability may be provided by viral encoded proteins produced by recombinant DNA techniques or by synthetic peptides corresponding to appropriate viral epitopes. We have expressed at high levels in E. coli a gag gene segment corresponding to approximately 97% of the p55 gag precursor protein, as well as a novel gag/env fusion protein that contains antigenic determinants in common with gag p24, env gp41, and env gp120. The gag and gag/env proteins were purified from insoluble inclusion bodies by sequential extraction with increasing concentrations of urea. These components were tested for reactivity with antisera to HIV proteins and peptides. We have also chemically synthesized a peptide corresponding to env residues 578-608, representing a portion of env gp41. The final preparation of gag and gag/env proteins in 8 M urea reacted with sheep anti-HTLV-III p24 gag antibodies and acquired immune deficiency syndrome (AIDS) patient sera. The gag/env fusion protein also reacted with rabbit anti-HIV env 500-511 peptide antibody. Both recombinant proteins and the env peptide were suitable as reagents for evaluation of serum samples by enzyme-linked immunosorbent assay (ELISA). Results of ELISA assays utilizing the recombinant viral proteins and synthetic peptide were in good agreement with results obtained using disrupted virus as antigen in ELISA assays and immunoblotting.
Transfusion Medicine Reviews, 1989
Human immunodeficiency virus (HIV) is the etiological agent in acquired immunodeficiency syndrome... more Human immunodeficiency virus (HIV) is the etiological agent in acquired immunodeficiency syndrome (AIDS). The presence of antibodies against HIV is indicative of prior exposure to HIV. Currently available antibody screening tests use HIV-infected cells as a source of viral antigens. This approach has resulted in inherent flaws, including a high rate of false-positive results. In order to develop a highly specific and sensitive test, various proteins of HIV [envelope (env), gag, pol] were cloned and expressed. In addition, we synthesized peptides corresponding to various regions of envelope (gp120, gp41), tat, art, and the protease gene products were synthesized. Using these synthetic peptides and cloned proteins, several conserved and highly antigenic epitopes in viral envelope were identified. Fusion proteins were made from the highly conserved and antigenic epitopes of env and gag. One of these fusion proteins, env-gag, was used to develop an enzyme immunoassay that would detect the antibodies against both env and gag epitopes. A clinical study of 13,781 samples demonstrated the very high specificity (99.9%) and sensitivity (100%) of this assay.
Progress in clinical and biological research, 1983
Interferon exhibits pleotropic effects on homologous cells. Interferons may be used clinically fo... more Interferon exhibits pleotropic effects on homologous cells. Interferons may be used clinically for both antiviral and antitumor therapy. A better understanding of how interferon achieves its hormonal effects should be useful in developing more judicious and specific applications of these natural substances in therapy. Interferon induces increased activity of two enzymes, 2'5'-oligoadenylate synthetase and a protein kinase, that depend on double-stranded RNA for activation. 2'5' A polymerizes ATP into a novel 2'5'-linked oligonucleotide, which in turn can activate a latent cellular nuclease (RNase L) which degrades mRNA. The second dsRNA-dependent enzyme, a protein kinase, phosphorylates a protein of approximately 67,000 daltons as well as the small subunit of eukaryotic initiation factor (eIF-2). The phosphorylation of eIF-2 results in the inhibition of protein synthesis. The extent of sensitivity to exogenous interferon could be influenced by several factors...
Rapid Methods and Automation in Microbiology and Immunology, 1991
ABSTRACT Influenza viruses are usually associated with epidemic respiratory infections in all age... more ABSTRACT Influenza viruses are usually associated with epidemic respiratory infections in all age groups (Glenzen 1982; Kendal and Walls 1987). Influenza A and B produce symptoms in humans that are not pathognomonic. During epidemics, the infection may be diagnosed on a clinical basis. However, isolated cases, as well as patients seen at the beginning of an outbreak between epidemics, are difficult to diagnose clinically. A series of infectious agents such as respiratory syncytial virus, adenovirus, corona virus, rhinovirus, the parainfluenza virus group, and Mycoplasma pneumonia can produce the clinical symptoms often designated as “the flu” (Huley 1987). Definitive diagnosis of influenza virus infection has traditionally relied on viral isolation or serology. However, the time required for laboratory diagnosis has often exceeded the duration of the disease. These delayed laboratory reports coupled with the lack of specific therapy resulted in decreased interest in obtaining a laboratory diagnosis. However, the recent availability of specific antiviral agents and rapid diagnostic techniques have revived the interest in laboratory diagnosis.
Cellular Responses to Molecular Modulators, 1981
Journal of the National Cancer Institute, 1980
Pregnant rabbits of two partially inbred strains, WH/J and IIIVO/J, were given ten consecutive da... more Pregnant rabbits of two partially inbred strains, WH/J and IIIVO/J, were given ten consecutive daily ip injections of 10 mg N-ethyl-N-nitrosourea (ENU)/kg dissolved in trioctanoin starting on either day 10, 15, or 18 of gestation. Of 7 WH/J progeny weaned, 3 developed primary renal tumors at 6.8 +/- 0.6 months of age (mean +/- SE). Similarly, of 12 IIIVO/J progeny weaned, 10 developed primary renal tumors at 6.3 +/- 0.6 months of age (mean +/- SE); in addition, 1 fibroblastic osteosarcoma and 5 neurofibromas, some associated with neurilemma cysts, were observed. Renal tumors were nephroblastomas , which appeared to develop within small renal cortical cysts. The frequency of tumor induction for each strain was similar to that in our previous experiments with acute administration of ENU and ethyl-urea plus NaNO2, but the latency period (6.4 +/- 0.5 mo) was almost doubled. In addition, chronic treatment of ENU induced teratogenic effects. In a number of these progeny, a disproportionat...
Progress in clinical and biological research, 1983
Interferon exhibits pleotropic effects on homologous cells. Interferons may be used clinically fo... more Interferon exhibits pleotropic effects on homologous cells. Interferons may be used clinically for both antiviral and antitumor therapy. A better understanding of how interferon achieves its hormonal effects should be useful in developing more judicious and specific applications of these natural substances in therapy. Interferon induces increased activity of two enzymes, 2'5'-oligoadenylate synthetase and a protein kinase, that depend on double-stranded RNA for activation. 2'5' A polymerizes ATP into a novel 2'5'-linked oligonucleotide, which in turn can activate a latent cellular nuclease (RNase L) which degrades mRNA. The second dsRNA-dependent enzyme, a protein kinase, phosphorylates a protein of approximately 67,000 daltons as well as the small subunit of eukaryotic initiation factor (eIF-2). The phosphorylation of eIF-2 results in the inhibition of protein synthesis. The extent of sensitivity to exogenous interferon could be influenced by several factors...
Texas reports on biology and medicine
Cancer Research, 1977
We describe the antitumor effects of a certain RNA(s) isolated from murine tumors and embryos. A ... more We describe the antitumor effects of a certain RNA(s) isolated from murine tumors and embryos. A single i.v. injected of 10 to 30 microgram of this RNA(s) induces necrosis, hemorrhages, and regression of solid tumors in the strain of origin; in pregnant mice it is embryotoxic, causing resorption of the embryos, but has no toxic effect upon the tumor-bearing or pregnant host. Its action is highly specific, and its presence in both tumors and embryos suggests that it may result from reexpression of embryonic genes in tumor cells.
ABSTRACT-Pregnant rabbits of two partially inbred strains. WH/J and IIIVO/J. were given ten conse... more ABSTRACT-Pregnant rabbits of two partially inbred strains. WH/J and IIIVO/J. were given ten consecutive daily ip injections of 10 mg N-ethyl-N-nitrosourea (ENU)/kg dissolved In trioctanoin starting on either day 10. 15. or 18 of gestation. Of 7 WH/J progeny weaned. 3 developed primary renal tumors at 6.8±0.6 months of age (mean ± SE). Similarly. of 12 IIiVO/J progeny weaned. 10 developed primary renal tumors at 6.3±0.6 months of age (mean ± SE); in addition. 1 fibroblastic osteosarcoma and 5 neurofibromas. some associated with neurilemma cysts. were observed. Renal tumors were nephroblastomas. which appeared to develop within small renal cortical cysts. The frequency of tumor induction for each strain was similar to that in our previous experiments with acute administration of ENU and ethyl-urea plus NaN0 2 • but the latency period (6.4±0.5 mol was almost doubled. In addition. chronic treatment of ENU induced terato-
Texas reports on biology and medicine, 1981
Journal of Biological Chemistry
Journal of immunology (Baltimore, Md. : 1950), 1985
Human cytomegalovirus contains approximately 30 to 35 structural polypeptides. Although antibodie... more Human cytomegalovirus contains approximately 30 to 35 structural polypeptides. Although antibodies to several of these proteins are made during natural infection, their relationship to T cell recognition of this virus and subsequent control of infection is poorly understood. We have purified one of these proteins (HCMVgp64) that is found in abundance in infected cell lysates in order to delineate the relationship of single viral proteins to the immune response caused by the virus. HCMVgp64 induced T cell reactivity only in individuals with serologic evidence of past infection. In addition, HCMVgp64 elicited similar in vitro immune reactions as the whole virus including T cell proliferation, interleukin 2 production, and receptor expression as well as interferon production. These studies suggest that single proteins of HCMV such as HCMVgp64 are capable of inducing T cell responses and may be important in the development of immune reactivity to HCMV.
Proceedings of the National Academy of Sciences, 1988
Genome Research, 1992
To simplify our procedure for blood sample processing for PCR, we introduced a simpler, shorter, ... more To simplify our procedure for blood sample processing for PCR, we introduced a simpler, shorter, and more cost-effective method for the separation of peripheral blood lymphocytes (PBL) and DNA extraction for amplification with Taq polymerase. By this method, blood samples are processed in two simple 15-min steps: (1) separation of PBLs from whole blood by red blood cell lysis with the Roche Specimen Washing Solution, and (2) DNA extraction by heat-detergent treatment of separated PBLs. This new method is simpler than the standard Ficoll-Hypaque method for PBLs separation and Proteinase K digestion for DNA extraction. It is not inhibitory to DNA amplification and it allows effective processing of blood samples even after prolonged storage (as long as 8 days) at room temperature.
Biochemical and Biophysical Research Communications, 1981
... ACYL CHAINS OF PHOSPHOLIPIDS INDUCED BY INTERFERON IN MOUSE SARCOMA S180 CELLS Kuttikkatt Cha... more ... ACYL CHAINS OF PHOSPHOLIPIDS INDUCED BY INTERFERON IN MOUSE SARCOMA S180 CELLS Kuttikkatt Chandrabose and Pedro Cuatrecasas Department ... Pfeffer, LM, Wang, E.,Landsberger, FR, and Tamm, E. (1980) Methods in Enzymology, Interferons ed. S. Pestka ...
Biochemical and Biophysical Research Communications, 1985
Analytical Biochemistry, 1987
Diagnostic reagents for detection of human immunodeficiency virus (HIV) exposure with improved re... more Diagnostic reagents for detection of human immunodeficiency virus (HIV) exposure with improved reliability may be provided by viral encoded proteins produced by recombinant DNA techniques or by synthetic peptides corresponding to appropriate viral epitopes. We have expressed at high levels in E. coli a gag gene segment corresponding to approximately 97% of the p55 gag precursor protein, as well as a novel gag/env fusion protein that contains antigenic determinants in common with gag p24, env gp41, and env gp120. The gag and gag/env proteins were purified from insoluble inclusion bodies by sequential extraction with increasing concentrations of urea. These components were tested for reactivity with antisera to HIV proteins and peptides. We have also chemically synthesized a peptide corresponding to env residues 578-608, representing a portion of env gp41. The final preparation of gag and gag/env proteins in 8 M urea reacted with sheep anti-HTLV-III p24 gag antibodies and acquired immune deficiency syndrome (AIDS) patient sera. The gag/env fusion protein also reacted with rabbit anti-HIV env 500-511 peptide antibody. Both recombinant proteins and the env peptide were suitable as reagents for evaluation of serum samples by enzyme-linked immunosorbent assay (ELISA). Results of ELISA assays utilizing the recombinant viral proteins and synthetic peptide were in good agreement with results obtained using disrupted virus as antigen in ELISA assays and immunoblotting.
Transfusion Medicine Reviews, 1989
Human immunodeficiency virus (HIV) is the etiological agent in acquired immunodeficiency syndrome... more Human immunodeficiency virus (HIV) is the etiological agent in acquired immunodeficiency syndrome (AIDS). The presence of antibodies against HIV is indicative of prior exposure to HIV. Currently available antibody screening tests use HIV-infected cells as a source of viral antigens. This approach has resulted in inherent flaws, including a high rate of false-positive results. In order to develop a highly specific and sensitive test, various proteins of HIV [envelope (env), gag, pol] were cloned and expressed. In addition, we synthesized peptides corresponding to various regions of envelope (gp120, gp41), tat, art, and the protease gene products were synthesized. Using these synthetic peptides and cloned proteins, several conserved and highly antigenic epitopes in viral envelope were identified. Fusion proteins were made from the highly conserved and antigenic epitopes of env and gag. One of these fusion proteins, env-gag, was used to develop an enzyme immunoassay that would detect the antibodies against both env and gag epitopes. A clinical study of 13,781 samples demonstrated the very high specificity (99.9%) and sensitivity (100%) of this assay.
Progress in clinical and biological research, 1983
Interferon exhibits pleotropic effects on homologous cells. Interferons may be used clinically fo... more Interferon exhibits pleotropic effects on homologous cells. Interferons may be used clinically for both antiviral and antitumor therapy. A better understanding of how interferon achieves its hormonal effects should be useful in developing more judicious and specific applications of these natural substances in therapy. Interferon induces increased activity of two enzymes, 2'5'-oligoadenylate synthetase and a protein kinase, that depend on double-stranded RNA for activation. 2'5' A polymerizes ATP into a novel 2'5'-linked oligonucleotide, which in turn can activate a latent cellular nuclease (RNase L) which degrades mRNA. The second dsRNA-dependent enzyme, a protein kinase, phosphorylates a protein of approximately 67,000 daltons as well as the small subunit of eukaryotic initiation factor (eIF-2). The phosphorylation of eIF-2 results in the inhibition of protein synthesis. The extent of sensitivity to exogenous interferon could be influenced by several factors...
Rapid Methods and Automation in Microbiology and Immunology, 1991
ABSTRACT Influenza viruses are usually associated with epidemic respiratory infections in all age... more ABSTRACT Influenza viruses are usually associated with epidemic respiratory infections in all age groups (Glenzen 1982; Kendal and Walls 1987). Influenza A and B produce symptoms in humans that are not pathognomonic. During epidemics, the infection may be diagnosed on a clinical basis. However, isolated cases, as well as patients seen at the beginning of an outbreak between epidemics, are difficult to diagnose clinically. A series of infectious agents such as respiratory syncytial virus, adenovirus, corona virus, rhinovirus, the parainfluenza virus group, and Mycoplasma pneumonia can produce the clinical symptoms often designated as “the flu” (Huley 1987). Definitive diagnosis of influenza virus infection has traditionally relied on viral isolation or serology. However, the time required for laboratory diagnosis has often exceeded the duration of the disease. These delayed laboratory reports coupled with the lack of specific therapy resulted in decreased interest in obtaining a laboratory diagnosis. However, the recent availability of specific antiviral agents and rapid diagnostic techniques have revived the interest in laboratory diagnosis.
Cellular Responses to Molecular Modulators, 1981
Journal of the National Cancer Institute, 1980
Pregnant rabbits of two partially inbred strains, WH/J and IIIVO/J, were given ten consecutive da... more Pregnant rabbits of two partially inbred strains, WH/J and IIIVO/J, were given ten consecutive daily ip injections of 10 mg N-ethyl-N-nitrosourea (ENU)/kg dissolved in trioctanoin starting on either day 10, 15, or 18 of gestation. Of 7 WH/J progeny weaned, 3 developed primary renal tumors at 6.8 +/- 0.6 months of age (mean +/- SE). Similarly, of 12 IIIVO/J progeny weaned, 10 developed primary renal tumors at 6.3 +/- 0.6 months of age (mean +/- SE); in addition, 1 fibroblastic osteosarcoma and 5 neurofibromas, some associated with neurilemma cysts, were observed. Renal tumors were nephroblastomas , which appeared to develop within small renal cortical cysts. The frequency of tumor induction for each strain was similar to that in our previous experiments with acute administration of ENU and ethyl-urea plus NaNO2, but the latency period (6.4 +/- 0.5 mo) was almost doubled. In addition, chronic treatment of ENU induced teratogenic effects. In a number of these progeny, a disproportionat...
Progress in clinical and biological research, 1983
Interferon exhibits pleotropic effects on homologous cells. Interferons may be used clinically fo... more Interferon exhibits pleotropic effects on homologous cells. Interferons may be used clinically for both antiviral and antitumor therapy. A better understanding of how interferon achieves its hormonal effects should be useful in developing more judicious and specific applications of these natural substances in therapy. Interferon induces increased activity of two enzymes, 2'5'-oligoadenylate synthetase and a protein kinase, that depend on double-stranded RNA for activation. 2'5' A polymerizes ATP into a novel 2'5'-linked oligonucleotide, which in turn can activate a latent cellular nuclease (RNase L) which degrades mRNA. The second dsRNA-dependent enzyme, a protein kinase, phosphorylates a protein of approximately 67,000 daltons as well as the small subunit of eukaryotic initiation factor (eIF-2). The phosphorylation of eIF-2 results in the inhibition of protein synthesis. The extent of sensitivity to exogenous interferon could be influenced by several factors...
Texas reports on biology and medicine