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N Barrett

Publications and source records attributed to N Barrett.

31 records · Page 2Linked to original sources
PubMed1989

Large-scale production and purification of a vaccinia recombinant-derived HIV-1 gp160 and analysis of its immunogenicity.

The human immunodeficiency virus (HIV-1) envelope gene was expressed in large-scale microcarrier cultures of Vero cells using a system involving coinfection with two recombinant vaccinia viruses. One recombinant contained the bacteriophage T7 RNA polymerase gene under control of a vaccinia virus promoter. The second contained the HIV-1 gp160 gene flanked by T7 promoter and termination sequences. The protein was expressed on the surface of infected cells, and it was shown to have a molecular weight of 160 kD and to react with gp41 and gp120 specific monoclonal antibodies. After purification by successive affinity and ion-exchange chromatography, the protein was demonstrated to be present in a particulate form with a diameter in the range of 15-30 nm. When injected into goats a high-titer gp160 specific antibody response was elicited and group-specific neutralizing activity could be demonstrated in vitro. The immunogenicity of the protein was also studied in conjunction with a number of adjuvant formulations, and the highest potency in mice was obtained using a preparation with 0.2% Al(OH)3 and 0.25% deoxycholate.

Adjuvants, Immunologic↗
PubMed1988

Subclavian stenosis: a major complication of subclavian dialysis catheters.

Subclavian catheterisation is frequently used for acute vascular access for haemodialysis and is thought to rarely result in long-term clinical problems. Venography in 36 cases, however, revealed subclavian stenosis in 18 (50%), of whom five developed clinical problems. The incidence of subclavian-vein stenosis was related to the duration of catheterisation (P less than 0.05). It may also be more common in black patients. Subclavian catheterisation is therefore not necessarily an ideal form of acute vascular access.

Catheterization, Central Venous↗
PubMed1987

[Comparison of two ELISA kits for the demonstration of antibodies against LAV/HTLV-III].

Eight hundred sera from a non-risk group and thousand sera from people at risk for acquiring AIDS were tested for the presence of LAV/HTLV-III specific antibodies by ELISA test kits manufactured by Du Pont and Organon. Western Blot analysis was used as a confirmatory test. All Western Blot positive sera were also positive in the Du Pont ELISA which in addition revealed a very low rate of false positive results (0.44%). In the Organon ELISA negative results were obtained with one positive and one questionable positive serum, as determined by Western Blot. The possible problem of test sensitivity being too low has been taken into account by the manufacturer by changing the calculation of cut-off values.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Composition and supramolecular organization of the tectorial membrane.

We have shown that collagen accounts for approximately 40% of the total protein of the tectorial membrane (TM) of the guinea pig and have estimated several essential parameters of TM composition including dry weight, wet weight, and water content. The major collagenous protein was definitively identified as type II collagen by SDS-PAGE, CNBr peptide mapping, and immunoblot assays. Quick-freeze, deep-etch electron microscopy of the guinea pig TM demonstrated a dense meshwork of fibers embedded in a complex microfibrillar matrix which may consist of proteoglycans; the larger fibers were similar in size and appearance to type II collagen fibers of elastic cartilage. Finally, the comparative free amino acid profiles of TM strongly suggest that the TM is chemically transparent with respect to endolymph. Thus, the TM appears to consist of a highly hydrated matrix mechanically stabilized by type II collagen fibers.

Amino Acids↗
PubMed1978

Excitation-contraction coupling in skeletal muscle: blockade by high extracellular concentrations of calcium buffers.

High concentrations (80 to 90 millimolar) of the calcium buffers EGTA and citrate (less than 10(-7) molar free calcium ion) reversibly block excitation-contraction coupling in intact frog skeletal fibers, but do not block caffeine-induced contractures. Solutions containing the same free calcium concentration but lower concentrations of calcium buffer (1 millimolar) do not block excitation-contraction coupling. These results suggest that excitation-contraction coupling requires the presence of calcium in a "protected" extracellular compartment, probably the transverse tubular network, and that calcium is actively transported into this compartment from the muscle cell cytoplasm.

Action Potentials↗
PubMedDate not supplied

Active bacterial core surveillance of the emerging infections program network.

Active Bacterial Core surveillance (ABCs) is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network. ABCs conducts population-based active surveillance, collects isolates, and performs studies of invasive disease caused by Streptococcus pneumoniae, group A and group B Streptococcus, Neisseria meningitidis, and Haemophilus influenzae for a population of 17 to 30 million. These pathogens caused an estimated 97,000 invasive cases, resulting in 10,000 deaths in the United States in 1998. Incidence rates of these pathogens are described. During 1998, 25% of invasive pneumococcal infections in ABCs areas were not susceptible to penicillin, and 13.3% were not susceptible to three classes of antibiotics. In 1998, early-onset group B streptococcal disease had declined by 65% over the previous 6 years. More information on ABCs is available at www.cdc.gov/ncidod/dbmd/abcs. ABCs specimens will soon be available to researchers through an archive.

Bacterial Infections↗