Biomedical subjects

R J Jariwalla

Publications and source records attributed to R J Jariwalla.

23 records · Page 2Linked to original sources

PubMed1980

Tumorigenic transformation induced by a specific fragment of DNA from herpes simplex virus type 2.

Transfection of Syrian hamster embryo cells with limit digests of Bgl II-, Hpa I-, or Bgl II/Hpa I-cleaved DNA from herpes simplex virus type 2 (strain S-1) but not with salmon sperm DNA resulted in the appearance of refractile, morphologically altered cells at a frequency of 10(-5)/0.005 microgram of viral DNA within two to four passages. Transformed lines manifested reduced serum requirement and anchorage-independent growth and were tumorigenic in newborn hamsters. They expressed ICP10, a viral protein immunologically identical to the cervical-tumor-associated AG-4 antigen. Transforming activity was localized in the 16.5 x 10(6)-dalton Bgl II/Hpa I double-digest fragment CDs-1, which exhibited sequence homology to the Bgl II/Hpa I fragment CD of DNA from herpes simplex virus type 2 strain 333, mapping between coordinates 0.43 and 0.58 on the physical map of strain 333 DNA. This fragment, CD333, was also shown to induce neoplastic transformation.

Adenoviruses, Human↗

PubMed1979

Neoplastic transformation of cultured Syrian hamster embryo cells by DNA of herpes simplex virus type 2.

Syrian hamster embryo cells were transformed to a neoplastic phenotype after exposure to herpes simplex virus type 2 (S-1) DNA at concentrations (less than or equal to 0.01 microgram per 60-mm dish) at which infectivity was no longer demonstrable. Transformed cells manifested in vitro phenotypic properties characteristic of the neoplastic state, expressed herpes simplex virus-specific antigens, and induced invasive tumors in vivo. Transfection and transformation of Syrian hamster embryo cells with herpes simplex virus type 2 DNA or its fragments is a suitable system for investigating the structure and function of herpes simplex virus-transforming gene(s).

Animals↗

PubMed1977

Effect of chaotropic salts and protein denaturants on the thermal stability of mouse fibroblast interferon.

Altering the aqueous environment, especially with agents that affect hydrogen bonds, markedly affects the stability of mouse L cell interferon. Low pH stabilizes interferon whereas high pH labilizes it; heavy water further enhances interferon thermostability at pH 2 but not at pH 9. Exposure to the protein denaturants, 4 M-guanidine hydrochloride and 6 M-urea, significantly decreases the activity of interferon at pH 2 and pH9; however, the residual interferon activity is relatively thermostable. Certain chaotropic salts protect interferon against thermal destruction, and in terms of effectiveness, their sequence is in the order SCN- greater than 1- larger than or equal to Cl- = CiO4- - Br- greater than NO3-. Interferon becomes more stable to heat as the NaSCN concentration is increased from 0-25 M to 2-0 M. Molecular sieve chromatography of interferon in the presence of 1-5 M-NaSCN at pH 7 shows a shift in its apparent mol. wt. from 25000 to 42000. Unlike most proteins, the unfolded conformation of interferon appears to be more stable to heat than the molecule with a smaller Stokes' radius.

Deuterium↗

PubMedDate not supplied

Inositol hexaphosphate (IP6) as an anti-neoplastic and lipid-lowering agent.

IP6, a major dietary source of inositol phosphates, is a physiological antioxidant with potential to form complexes with cations linked to cell proliferation and hypercholesterolemia. Accordingly, we have examined the action of IP6 on dietary modulation of neoplasia and hyperlipidemia in a Fischer rat model (1, 2). Two studies were conducted on the effects of naturally-derived IP6, administered as purified phytate, a salt form of phytic acid (inositol hexaphosphoric acid). One study examined the effect on the growth of tumors promoted in syngeneic rats transplanted with a viral oncogene-transformed cell line. Increases in tumor incidence and growth rate of fibrosarcomas seen following administration of a special diet (containing 5% saturated fatty acids and 1.2% magnesium oxide) were completely mitigated by supplementation of the same diet with purified potassium-magnesium phytate (8.9% phytic acid by weight). The other study examined the IP6 effect on serum lipid and mineral levels in animals fed a cholesterol-enriched or standard diet. Elevated levels of serum total cholesterol, triglycerides and zinc/copper ratio associated with administration of the cholesterol-enriched diet were significantly lowered by supplementation of this diet with monopotassium phytate. Addition of monopotassium phytate to the standard diet also reduced serum lipid levels but did not significantly affect the zinc/copper ratio. These studies support a role for IP6 as a potential therapeutic agent in the treatment of cancer and hyperlipidemia.

Animals↗

PubMedDate not supplied

Ascorbate effect on cytokine stimulation of HIV production.

We have recently shown that ascorbic acid (AA) suppresses the production of HIV in a latently infected T-lymphocytic cell line (ACH-2) following stimulation with the tumor promoter, PMA. To evaluate the effect of ascorbic acid on virus activation following treatment with inflammatory cytokine, we tested tumor necrosis factor alpha (TNF-alpha) whose levels are elevated in patients with HIV/AIDS. ACH-2 cultures, pretreated with various nontoxic concentrations of ascorbate or AZT were stimulated for 2 h with TNF-alpha, and incubated further with fresh supplements of ascorbate or AZT. At 24 to 48 h post-treatment, the RT activity released into culture supernatant was determined. Results showed that TNF-alpha alone caused approximately 13- to 16-fold stimulation in the level of extracellular RT. Pretreatment with ascorbic acid at 200 micrograms/ml caused a little more than about 2- to 4-fold reduction in extracellular RT levels. Most remarkably, exposure to 300 micrograms/ml ascorbate resulted in approximately 5- to 10-fold lowering of the extra-cellular RT titer. In contrast, no significant suppression in extracellular RT levels was seen with concentrations of AZT in the range of 1-5 micrograms/ml.

Ascorbic Acid↗