Search PubMed⌕ Search

Biomedical subjects

B J Carter

Publications and source records attributed to B J Carter.

At least 19 recordsLinked to original sources
PubMed2001

Genome-wide linkage analysis of inherited hydrocephalus in the H-Tx rat.

Inherited hydrocephalus in humans has received very little attention, most probably because known occurrences are sporadic and systematic investigation is difficult. The H-Tx rat, one of a number of rodent strains with inherited hydrocephalus, has a complex inheritance with more than one postulated susceptibility gene and 40% penetrance. The aim of this study was to perform a genome-wide scan on backcross progeny derived from H-Tx and Fisher F344 rats, to identify genomic regions associated with hydrocephalus. Penetrance of hydrocephalus in (H-Tx x F344) F1 x H-Tx was 12.3%. All severely hydrocephalic progeny (n = 185) and a subset of normal progeny (n = 128) were screened with 110 simple sequence length polymorphisms (SSLPs) with 83% coverage of the genome. A significant susceptibility locus was found on chromosome (Chr) 11 (LOD = 3.1). Three loci with suggestive linkage were found on Chr 17 (LOD = 2.4), on Chr 9 (LOD = 1.94), and on Chr 19 (LOD = 1.91). For the loci on Chr 11 and 19, hydrocephalus was associated with the heterozygous genotype, while the other two were recessive. Although none of the four loci was essential for the hydrocephalic phenotype, the additive effects of two, three, or four loci increased the penetrance in a linear fashion. Altogether these four loci accounted for 13.5% of the total variance. It is concluded that hydrocephalus in the H-Tx rat is associated with two, possibly four genetic loci, but that there may be additional undefined genetic and environmental influences.

Animals↗
PubMed2001

Chromosomal linkage associated with disease severity in the hydrocephalic H-Tx rat.

Infantile hydrocephalus results in neurological deficits despite surgical treatment. Fetal-onset hydrocephalus in humans can be caused by developmental abnormalities that are genetic in origin. The H-Tx rat has hydrocephalus with 40% penetrance and a polygenic inheritance. A backcross with Fisher F344 inbred strain produced a total of 1500 progeny with 17.5% hydrocephalus. Of these, only 12.3% had overt disease and the remaining 5.2% had mild disease seen only after fixation of the brain. Disease severity was measured for all affected rats using the ratio of ventricle to brain width. The severity measure confirmed that there are two populations, mild hydrocephalus (M; ratio, <0.4) and severe hydrocephalus (S; ratio, >0.4), with a small overlap. For genotyping, the two populations were each subdivided based on the ratio measure to give a total of four groups of increasing severity. After an initial genome scan with microsatellite markers, all hydrocephalic rats and a subset of 128 normal progeny were genotyped on chromosomes 4, 9, 10, 11, 17 and 19. Rats in the mildest group had association with a locus on chromosome 4 (LOD 2.4), whereas those in the severest group were associated with a locus on chromosome 17 (LOD 3.2). All except the least affected group were associated with a heterozygous genotype on chromosomes 10 and 11 (LOD 4.5 and 3.5, respectively). Chromosomes 9 and 19 had weak linkage to hydrocephalus. The number of hydrocephalus-associated loci carried by each rat correlated with the severity of disease. It is concluded that the severity of hydrocephalus in H-Tx is influenced by different genetic loci.

Animals↗
PubMed2000

The expression of inherited hydrocephalus in H-Tx rats.

OBJECTIVES: H-Tx rats develop severe hydrocephalus in late gestation. The breeding colony maintained at the University of Florida stems from one pair obtained in 1992. The aims of this study were to characterize the expression of hydrocephalus in the H-Tx rat colony, to perform within-strain and between-strain DNA analysis and to examine hydrocephalus expression in specific breeding experiments. METHODS AND OBSERVATIONS: Matings between normal rats produce hydrocephalic offspring almost without exception, and the overall frequency is stable between generations at 40%. However, frequency varies with parity, being only 27% in the first litters, and it also varies with sex, there being an excess of male hydrocephalics. Mating between shunt-treated hydrocephalic rats did not increase the frequency. DNA typing with microsatellite markers showed that there was some residual heterogeneity in the colony despite inbreeding for 22 generations, although it did not segregate with hydrocephalus. Test mating with two other inbred strains, F344 and LEW produced some affected pups in the LEW cross only. A backcross experiment between H-Tx and F344 produced 12.3% severely-affected pups and 5.4% pups with a mild form, indicating the presence of several susceptibility genes. CONCLUSIONS: All animals in our H-Tx colony are homozygous for the hydrocephalus loci, but there is incomplete penetrance.

Animals↗
PubMed1999

The presence of transforming growth factor e in bovine mammary gland.

Transforming growth factor e (TGFe) was demonstrated immunohistochemically in the bovine mammary gland, mainly in the glandular and ductal epithelium. In the teat, its expression was largely limited to the skin keratinocytes, ductal epithelium and ductal glands. It is suggested that this growth factor plays a role in lactation.

Animals↗
PubMed1999

Safety and biological efficacy of an adeno-associated virus vector-cystic fibrosis transmembrane regulator (AAV-CFTR) in the cystic fibrosis maxillary sinus.

OBJECTIVE: The host immune response and low vector efficiency have been key impediments to effective cystic fibrosis transmembrane regulator (CFTR) gene transfer for cystic fibrosis (CF). An adeno-associated virus vector (AAV-CFTR) was used in a phase I dose-escalation study to transfer CFTR cDNA into respiratory epithelial cells of the maxillary sinus of 10 CF patients. STUDY DESIGN: A prospective, randomized, unblinded, dose-escalation, within-subjects, phase I clinical trial of AAV-CFTR was conducted. PATIENTS: Ten patients with previous bilateral maxillary antrostomies were treated. MAIN OUTCOME MEASURES: Safety, gene transfer as measured by semiquantitative polymerase chain reaction (PCR), and sinus transepithelial potential difference (TEPD) were measured. RESULTS: The highest level of gene transfer was observed in the range of 0.1-1 AAV-CFTR vector copy per cell in biopsy specimens obtained 2 weeks after treatment. When tested, persistence was observed in one patient for 41 days and in another for 10 weeks. Dose-dependent changes in TEPD responses to pharmacologic intervention were observed following treatments. Little or no inflammatory or immune responses were observed. CONCLUSION: AAV-CFTR administration to the maxillary sinus results in successful, dose-dependent gene transfer to the maxillary sinus and alterations in sinus TEPD suggestive of a functional effect, with little or no cytopathic or host immune response. Further study is warranted for AAV vectors as they may prove useful for CFTR gene transfer and other in vivo gene transfer therapies. A prospective, randomized, double-blind, placebo-controlled, within-subjects, phase II clinical trial of the effect AAV-CFTR on clinical recurrence of sinusitis will determine the clinical efficacy of AAV gene therapy for CF.

Adult↗
PubMed1999

Repeated delivery of adeno-associated virus vectors to the rabbit airway.

Efficient local expression from recombinant adeno-associated virus (rAAV)-cystic fibrosis (CF) transmembrane conductance regulator (CFTR) vectors has been observed in the airways of rabbits and monkeys for up to 6 months following a single bronchoscopic delivery. However, it is likely that repeated administrations of rAAV vectors will be necessary for sustained correction of the CF defect in the airways. The current study was designed to test the feasibility of repeated airway delivery of rAAV vectors in the rabbit lung. After two doses of rAAV-CFTR to the airways, rabbits generated high titers of serum anti-AAV neutralizing antibodies. Rabbits then received a third dose of a rAAV vector containing the green fluorescent protein (GFP) reporter gene packaged in either AAV serotype 2 (AAV2) or serotype 3 (AAV3) capsids. Each dose consisted of 1 ml containing 5 x 10(9) DNase-resistant particles of rAAV vector, having no detectable replication-competent AAV or adenovirus. Three weeks later, GFP expression was observed in airway epithelial cells despite high anti-AAV neutralizing titers at the time of delivery. There was no significant difference in the efficiency of DNA transfer or expression between the rAAV3 and rAAV2 groups. No significant inflammatory responses to either repeated airway exposure to rAAV2-CFTR vectors or to GFP expression were observed. These experiments demonstrate that serum anti-AAV neutralizing antibody titers do not predict airway neutralization in vivo and that repeated airway delivery rAAV allows for safe and effective gene transfer.

Animals↗
PubMed1997

Stabilization of the B conformation in unoriented films of calf thymus DNA by NaCl: a Raman and IR study.

Unoriented films of calf thymus NaDNA with either 3.0 or 5.0 NaCl per base pair were prepared by dehydrating unstressed gels. These films were studied by Raman and ir spectroscopy. The 5.0 samples showed very strong vibrational modes characteristic of the B conformation at relative humidities (RH) as low as 30%, indicating that those samples were entirely in the B conformation. The 3.0 samples showed weaker features: some of the DNA in these samples were in the B conformation at 80% RH while the DNA is essentially in a disordered phase at 30% RH.

Animals↗
PubMed1997

Women's experiences of lymphedema.

PURPOSE/OBJECTIVES: To explore women's experiences of lymphedema. DESIGN: Qualitative descriptive. SETTING: An urban community in the midwestern United States. SAMPLE: Ten women who experienced lymphedema after breast cancer treatment and who had (a) completed their treatment for stage I or stage II breast cancer at least one year before the study, (b) experienced an onset of lymphedema at least two months after surgery, (c) no current evidence of cancer disease or cancer recurrence, (d) lymphedema not caused by cancer in the brachial plexus, and (e) no history of hospitalization for alcoholism, substance abuse, or psychiatric conditions. The women ranged in age from 36-75 years. Mean survival time was seven years, and the mean time since onset of lymphedema was four years. METHODS: Two in-depth interviews per participant. PATIENTS: Most women were able to continue living their normal lives. Some women experienced depression, anxiety, and impairments related to their intimate, work, and social relationships. Physicians' limited knowledge about lymphedema, conflicting treatment information, and the limited number of available treatment centers caused distress for the participants. Their experiences can be categorized into three predominant themes: Abandonment by Medicine, Concealing the imperfect image, and Living the Interrupted Life. CONCLUSIONS: Research efforts to expand the knowledge base regarding the epidemiology, prevention, and treatment of lymphedema are needed. Also needed is research that explores the impact of lymphedema on quality of life and functional ability as well as the psychosocial impact of lymphedema on body image, self esteem, and social support. IMPLICATIONS FOR NURSING PRACTICE: Care providers and breast cancer survivors should be educated about the prevention and treatment of lympedema. Nurses should refer patients to advocacy hot lines and support groups for information and support when appropriate. Women with lymphedema should be assessed periodically for psychosocial distress and referred for care as needed.

Activities of Daily Living↗
PubMed1996

Interaction of wild-type and mutant adeno-associated virus (AAV) Rep proteins on AAV hairpin DNA.

Both the Rep68 and Rep78 proteins of adeno-associated virus type 2 (AAV) bind to AAV terminal repeat hairpin DNA and can mediate site-specific nicking in vitro at the terminal resolution site (trs) within the terminal repeats. To define the regions of the Rep proteins required for these functions, a series of truncated Rep78 derivatives was created. Wild-type and mutant proteins were synthesized by in vitro translation and analyzed for AAV hairpin DNA binding, trs endonuclease activity, and interaction on hairpin DNA. Amino-terminal deletion mutants which lacked the first 29 or 79 amino acid residues of Rep78 did not bind hairpin DNA, which is consistent with our previous identification of a DNA-binding domain in this region. Progressive truncation of the carboxyl-terminal region of Rep78 did not eliminate hairpin DNA binding until the deletion reached amino acid 443. The electrophoretic mobility of the Rep-specific protein-DNA complexes was inversely related to the molecular weight of the Rep derivative. Analysis of the C-terminal deletion mutants by the trs endonuclease assay identified a region (amino acids 467 to 476) that is essential for nicking but is not necessary for DNA binding. When endonuclease-positive, truncated Rep proteins that bound hairpin DNA were mixed with full-length Rep78 or Rep68 protein in electrophoretic mobility shift assays, a smear of protein-DNA complexes was observed. This smear migrated at an intermediate position with respect to the bands generated by the proteins individually. An antibody recognizing only the full-length protein produced a novel supershift band when included in a mixed binding assay containing Rep68 and a truncated Rep mutant. These experiments suggest that the Rep proteins can form hetero-oligomers on the AAV hairpin DNA.

DNA↗
PubMed1996

In vivo model of adeno-associated virus vector persistence and rescue.

Gene therapy vectors based on human DNA viruses could be mobilized or rescued from individuals who are subsequently infected with the corresponding wild-type (wt) helper viruses. This phenomenon has been effectively modeled in vitro with both adenovirus (Ad) and adeno-associated virus (AAV) vectors but has not previously been studied in vivo. In the current study, we have developed an in vivo model to study the interactions of a recombinant AAV vector (AAV-CFTR) with wt AAV type 2 (AAV2) and a host range mutant Ad (Ad2HR405) for which monkey cells are permissive (D.E.Brough, S.A.Rice, S.Sell, and D.F.Klessig, J. Virol. 55:206-212, 1985). AAV-CFTR was administered to the respiratory epithelium of the nose or lung of rhesus macaques. Primary cells were harvested from the infusion site at time points up to 3 months after vector administration to confirm vector DNA persistence. Vector DNA was present in episomal form and could be rescued in vitro only by addition of wt AAV2 and Ad. In in vivo rescue studies, vector was administered before or after wt-AAV2 and Ad2HR405 infection, and the shedding of AAV-CFTR was examined. Ad2HR405 and wt-AAV2 infections were established in the nose with concomitant administration. wt-AAV2 replication occurred in the lung when virus was administered directly at a high titer to the lower respiratory tract. AAV-CFTR vector rescue was also observed in the latter setting. Although these studies were performed with small numbers of animals within each group, it appears that AAV-CFTR DNA persists in the primate respiratory tract and that this model may be useful for studies of recombinant AAV vector rescue.

Adenoviridae↗
PubMed1996

Safety of single-dose administration of an adeno-associated virus (AAV)-CFTR vector in the primate lung.

Gene therapy for cystic fibrosis (CF) would ideally be accomplished with a vector capable of long-term expression of the cystic fibrosis transmembrane conductance regulator (CFTR) in the absence of a host inflammatory response. Recombinant adeno-associated virus (AAV)-CFTR vectors possess these characteristics in rabbits. Because the utility of AAV vectors as gene transfer agents has only been recognized recently, AAV vector-mediated transduction has never been modeled in a primate host, which is an important step before its use in humans. In order to test the safety and biological activity of AAV-CFTR, single doses of AAV-CFTR vector were administered by fiberoptic bronchoscopy to the posterior basal segment of the right lower lobe (RLL) of the lungs of 10 rhesus macaques with four matched vehicle-treated controls. Animals were followed for 10, 21, 90 or 180 days following vector instillation. Vector DNA transfer occurred in bronchial epithelial cells in the RLL of each animal that received vector as assessed by in situ DNA PCR. Vector mRNA was detectable for 180 days after administration as detected by RT-PCR and by RNase protection assay. Safety of vector administration was determined by measurements of pulmonary mechanics, arterial blood gas analysis, chest radiographs, and bronchoalveolar lavage (BAL) fluid analysis including cell count and quantification of inflammatory cytokines. Gross and microscopic pathologic examination were also performed. There was no evidence of inflammation or other toxicity, although vector DNA was found in extrapulmonary organs of some animals. These results indicate that transduction of the primate airway epithelium with the AAV-CFTR mediates long-term CFTR cDNA transfer and is relatively safe.

Animals↗