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Biomedical subjects

N C Jones

Publications and source records attributed to N C Jones.

62 records · Page 4Linked to original sources

Transformation-defective mutant of adenovirus type 5 containing a single altered E1a mRNA species.

A mutant of adenovirus type 5 containing an octanucleotide insert in region E1a of the viral genome was constructed. The insert was present in only one (13s) of the three overlapping mRNA's synthesized from this region. The insert was within the sequences removed by RNA splicing during the production of the other two nRNA's. The insertion resulted in a shift in the translational reading frame of the 13s mRNA and the probable premature termination of translation. The mutant was defective for viral DNA replication in HeLa cells and the transformation of rat embryo and baby rat kidney cells, indicating that a product encoded by the 13s nRNA is required for these two processes. Other early regions of the genome were expressed in HeLa cells infected by this mutant although in some cases the expression was decreased as compared with wild-type-infected cells.

Adenoviruses, Human↗

Tuberculosis presenting as a pelvis mass.

Tuberculosis is one of the world's most important communicable diseases. Although it may involve the genital tract and frequently results in infertility, the presentation of the disease as a pelvic mass is uncommon. While the incidence of tuberculosis has declined in the United States, genital tuberculosis should be considered in patients presenting with adnexal mass and a history of infertility. One such case is presented here, and diagnosis and treatment are described.

Adult↗

Interaction of Salmonella typhimurium with phospholipid vesicles. Incorporation of exogenous lipids into intact cells.

Incubation of intact cells of Salmonella typhimurium with bilayer phospholipid vesicles results in significant transfer of vesicle lipids to the cells. The transfer requires Ca2+ or spermine, and is dependent on time, temperature, the concentration and composition of the vesicles, and the nature of the cellular lipopolysaccharide. The process results in bulk transfer of vesicle lipids to the cells rather than reciprocal molecular exchange between vesicles and the outer membrane. All components of mixed lipid vesicles, including cholesteryl oleate and lipopolysaccharide, are transferred to the cells in a ratio similar to that of the donor vesicles. The properties of the transfer process are consistent with direct fusion of vesicles with the outer membrane of the cell.

Calcium↗

Translocation of phospholipids between the outer and inner membranes of Salmonella typhimurium.

The reversibility and specificity of phospholipid translocation between the inner and outer membrane of Salmonella typhimurium has been investigated by incorporating exogenous lipids from phospholipid vesicles into the outer membrane of intact cells. Translocation of newly incorporated phospholipids to the inner membrane was demonstrated by decarboxylation of vesicle-derived phosphatidylserine and by recovery of vesicle constituents in both inner and outer membrane fractions. All Salmonella phospholipids tested, as well as phosphatidylcholine and cholesteryl oleate were effectively translocated to the inner membrane. However, no translocation of vesicle-derived lipopolysaccharide or an incomplete biosynthetic precursor of lipid A could be detected. Translocation of phospholipids and cholesteryl ester was rapid and extensive, and appeared to lead to equilibration of the lipids between the two membranes. The mechanism of intermembrane translocation has not been established, but the results are suggestive of diffusional flow across zones of adhesion between the inner and outer membranes.

Cell Membrane↗