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T Carter

Publications and source records attributed to T Carter.

At least 55 records · Page 3Linked to original sources
PubMed1992

Formation of a multilayer cellular lining on a polyurethane vascular graft following endothelial cell sodding.

Small-diameter (less than 6 mm) clinically available vascular grafts often fail due in part to the inherent thrombogenicity of artificial polymers. Transplantation of endothelial cells onto the lumen of these vascular grafts has been suggested as one method to overcome this thrombogenicity. We have developed a compliant polyurethaneurea (PEUU) 4-mm graft with a luminal surface modified by a glow discharge gas plasma. Autologous microvessel endothelial cells were isolated from canine falciform ligament fat, were transplanted onto the luminal surface of the grafts using an intraoperative isolation and sodding technique, and both endothelial-cell-treated and non-cell-treated grafts were placed as bilateral carotid interposition grafts in a canine model. After 5 weeks of implantation, explanted control (non-cell-treated) grafts exhibited a deposition of platelets, white cells and fibrin characteristic of a thrombogenic surface. MVEC sodded grafts exhibited a multicellular lining within but distinct from the lumen of the PEUU graft. The blood-contacting surface of this lining exhibited an antithrombogenic endothelial cell monolayer. We suggest that the PEUU graft supported the initial deposition of MVEC and development of and endothelial cell lining. During the 5 weeks of implantation this lining continued to proliferate and detached from the PEUU graft substratum. The final neocellular lining exhibited a luminal diameter and histological features similar to a native artery.

Animals↗
PubMed1990

Frequency and organization of pap homologous DNA in relation to clinical origin of uropathogenic Escherichia coli.

The pap operon encodes the gal alpha 1-4gal beta specific adhesins of Escherichia coli. The presence and organization of pap homologous DNA was determined using two probes specific for pap in 217 uropathogenic E. coli samples by dot blot and Southern blot analysis. The frequency of pap homologous DNA was 76% in pyelonephritis, 69% in cystitis, and 52% in an asymptomatic bacteriuria group. Further, the gal alpha 1-4gal beta binding phenotype among the pap-positive strains was expressed more often in acute pyelonephritis (91%) than the cystitis (60%) or asymptomatic bacteriuria (52%) strains. This was explained in part by difference in organization of pap homologous DNA between the genotypically positive pyelonephritis and asymptomatic bacteriuria strains. The pyelonephritis isolates contained three copies of pap significantly more often than the asymptomatic bacteriuria strains, and the pyelonephritogenic O-antigen types had a general increase in pap copy number. The difference in expression of gal alpha 1-4gal beta adhesins between pyelonephritis and asymptomatic bacteriuria isolates was thus not only a function of the frequency of pap homologous DNA but also of phenotypic expression among genotypically pap-positive strains.

Acute Disease↗
PubMed1990

A DNA-activated protein kinase from HeLa cell nuclei.

A DNA-activated protein kinase (DNA-PK) was purified from nuclei of HeLa cells. Activity was associated with a single high-molecular-mass (approximately-300,000 Da) polypeptide when analyzed by gel filtration, denaturing polyacrylamide gel electrophoresis, and Western immunoblotting using a monoclonal antibody that also inhibits enzyme activity. Nuclear localization was indicated by subcellular fractionation and confirmed by immunofluorescence on whole cells. Double-stranded DNA stimulated phosphorylation of the 300-kDa polypeptide in purified preparations as well as phosphorylation of the exogenous substrates alpha-casein, simian virus 40 large T antigen, and the human heat shock protein hsp90. Autophosphorylation led to inactivation of the enzyme. The phosphorylation of casein was stimulated over 30-fold by DNA and was specific for serine and threonine residues. Bovine serum albumin and histone H1 were poor substrates for DNA-PK, and no phosphorylation of immunoglobulin G or histones other than H1 was observed. Supercoiled or heat-denatured DNA and synthetic double-stranded RNA or RNA-DNA copolymers did not stimulate casein phosphorylation by DNA-PK. Interaction of the enzyme with DNA in the absence of exogenous substrates was demonstrated by thermal inactivation and gel mobility shifts. These characteristics identify DNA-PK as distinct from other protein kinases described in the literature and suggest that activation by DNA is an important feature of the enzyme's in vivo function.

Antibodies, Monoclonal↗
PubMed1987

Induction of integrated adenovirus E1A and E1B genes in transformed human cells by phorbol ester tumor promoters.

The effect of phorbol esters on transcription of human type 5 adenovirus (Ad5) early region 1 (E1) genes was studied in two human cell lines (293 and KB16) that contain integrated viral DNA. In 293 cells 12-O-tetradecanoylphorbol-13-acetate (TPA), phorbol 12,13-dibutyrate and phorbol 12,13-didecanoate caused a 2- to 3-fold increase in cytoplasmic levels of E1 RNA within 90 min, whereas the nonpromoting TPA analogues 4-alpha-phorbol 12,13-didecanoate and phorbol, or the addition of serum to serum-starved cells, had no effect on E1 RNA. Stimulation by TPA was transient, and the concentrations of all E1 RNA species returned to basal levels by 5 h. The kinetics of E1 RNA accumulation in the presence of TPA were unaffected by cycloheximide, although levels of E1 RNA remained elevated in these conditions. The apparent molecular sizes of major RNA species synthesized from the E1A and E1B regions in 293 cells were the same as those seen early in productive infection by Ad5, and were not changed after induction by TPA. Nuclear run-on assays showed that E1 transcription, as well as transcription of c-fos, c-myc, and beta-actin was stimulated in 293 cells within 30 min of TPA exposure and returned to basal levels by 60 min. In contrast to the 293 cells, expression of Ad5 E1 genes in a second transformed human cell line, KB16, was not altered by TPA. These results show that the induction of Ad5 E1 genes by TPA does not require their presence on infecting genomes, but suggest that inducibility of integrated, functionally expressed E1 genes can be influenced by factors other than their primary sequence.

Adenovirus Early Proteins↗
PubMed1979

[Prenatal diagnosis. Review, personal and prospective studies].

1. In a review of methods developed for the identification of fetal malformations, the technique, risks and results of amniocentesis are presented. 2. Large series already published have demonstrated the relative simplicity and feasibility of the procedure as well as current indications for its utilization. These include the detection of chromosomal anomalies, the determination of sex (in certain sex-linked disorders), documentation of enzymatic and metabolic deficiencies, and the demonstration of open lesions of the neural tube by appropriate techniques. 3. Experience with over 500 cases personally tested by the authors entirely confirms the major indications for and benefits of this modern method for the detection and prevention of severe congenital anomalies during early pregnancy. 4. The identification of chromosomal alterations is currently the major objective of the method. Increased risks are associated with pregnancies involving a maternal age of 35 years or older (which account for 1-3% of aneuploidies), the birth of a previous infant with free trisomy 21 (1% recurrence risk) or secondary to a parental chromosome translocation (as much as 10% risk of aneuploidy). Fetal karyotyping for determination of sex, in cases where the mother is a carrier of an X-linked recessive gene (on average, 50% of male offspring will be affected), is an inadequate method of diagnosis to be utilized only until alternative techniques render possible specific diagnosis of the anomalies under consideration (hemophilias A and B, muscular dystrophy, etc). 5. Several of these techniques are now nearing development through the advent of fetoscopy and advanced ultrasound methodology, and have already been applied to the detection of certain sex-linked disorders and also for diagnosis of hemoglobinopathies (thalassemias, sickel cell anemia) and other conditions requiring the obtaining of fetal blood for diagnosis. Technology allowing direct examination of fetal parts by means of optical instruments is particularly useful in cases where a severe fetal morphologic malformation cannot currently be identified by indirect visualization (ultrasound) or by analysis of cytogenetic or molecular markers. 6. Pathological accumulations of alpha-fetoprotein which are associated with diverse feto-placental abnormalities (particularly open malformations of the neural tube) can be detected in the amniotic fluid and/or maternal blood. In extension of this approach, it is foreseeable that conditions existing prenatally will be diagnosed in a growing number of cases from the study of fetal cells and molecules which can be isolated from the venous blood of pregnant women. This will become feasible as a result of some well-developed techniques which allow separation of fetal from maternal cells and metabolites, and also to some extremely fine analytic techniques, notably examination of the DNA itself by means of restriction enzymes.

Adult↗