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Biomedical subjects

Andrew Ross

Publications and source records attributed to Andrew Ross.

7 recordsLinked to original sources
PubMed2006

Characterization of the anti-fungal activity of a Bacillus spp. associated with sclerotia from Sclerotinia sclerotiorum.

Sclerotinia sclerotiorum fruiting bodies (sclerotia) were found to harbour bacteria that possess anti-fungal activity. Among 1,140 bacterial isolates collected, 32 were found to inhibit the growth of four common fungal pathogens of canola, S. sclerotiorum, Rhizoctonia solani, Alternaria brassicae and Leptosphaeria maculans. One of these broad-spectrum isolates, LEV-006, was found to be closely related to Bacillus subtilis based on 16S rRNA analysis. The anti-fungal activities were purified and found to be associated with a low molecular weight peptide complex consisting mostly of the cyclic lipopeptide fengycin A and B, as revealed by matrix-assisted laser desorption/ionization time-of-flight and post-source decay analysis, as well as two proteins of 20 and 55 kDa. Peptide mass fingerprinting revealed that the 55-kDa protein was similar to vegetative catalase 1; however, when the enzyme was expressed in Escherichia coli, it exhibited catalase but not anti-fungal activity. The sequences of several peptides from the 20-kDa protein were obtained and indicated that it was a unique anti-fungal protein.

Antibiosis↗
PubMed2006

What is the learning curve associated with double-balloon enteroscopy? Technical details and early experience in 6 U.S. tertiary care centers.

BACKGROUND: Performance parameters for double-balloon enteroscopy (DBE) have not been described. OBJECTIVE: To determine the learning curve for DBE. DESIGN: Prospective cohort study. SETTING: Six U.S. tertiary centers. PATIENTS: A total of 188 subjects undergoing 237 DBE procedures; 130 (69%) with obscure GI bleeding. INTERVENTIONS: Performance parameters from each center's initial 10 cases were compared to the subsequent examinations. MAIN OUTCOME MEASUREMENTS: Exam duration, depth of insertion, and findings on DBE examination. RESULTS: DBE was introduced by mouth in 149 (63%) cases, by rectum in 77 (33%) cases, and through a stoma in 6 (2.5%) patients. The mean (+/-SD) duration was 109.1 +/- 44.6 minutes for the first 10 cases and 92.4 +/- 37.6 minutes for subsequent cases (P = .005) but did not change for rectal DBE procedures. There was no change in mean depth of insertion, but the mean fluoroscopy time declined significantly (P = .025). Diagnostic or therapeutic maneuvers were performed in 64% of cases; DBE led to a diagnosis in 81 (43%) patients. A total of 78% of patients had prior capsule endoscopy (CE) with significant agreement between DBE and CE (kappa = 0.74). One perforation occurred (0.4%). Per-rectal cases failed to reach the small bowel in 24 (31%) cases. LIMITATIONS: All patients did not undergo initial CE. The therapeutic DBE scope was not available for the initial 8 months of the study. CONCLUSIONS: There was a significant decline in overall procedural time and fluoroscopy time after the initial 10 DBE cases. There was no improvement in performance parameters when DBE was performed via the rectal approach despite increased, but limited, operator experience.

Adolescent↗
PubMed2004

Localisation of centromeric proteins to a fraction of mouse minor satellite DNA on a mini-chromosome in human, mouse and chicken cells.

Centromeres are required for faithful segregation of chromosomes in cell division. It is not clear how centromere sites are specified on chromosomes in vertebrates. We have previously introduced a mini-chromosome, named ST1, into a variety of cell lines including human HT1080, mouse LA9 and chicken DT40. This mini-chromosome, segregating faithfully in these cells, contains mouse minor and major, and human Y alpha-satellite DNA repeats. In this study, after determining the organisation of the satellite repeats, we investigated the location of the centromere on the mini-chromosome by combined immunocytochemistry and fluorescence in situ hybridisation analysis. Centromeric proteins were consistently co-localised with the minor satellite repeats in all three cell lines. When chromatin fibres were highly stretched, centromeric proteins were only seen on a small portion of the minor satellite repeats. These results indicate that a fraction of the minor satellite repeats is competent in centromere function not only in mouse but also in human and chicken cells.

Animals↗
PubMed2002

Use of augmented rectus muscle transposition surgery for complex strabismus.

PURPOSE: Full tendon rectus muscle transposition surgery augmented with posterior fixation sutures has been shown to be effective in the treatment of abducens palsy and Duane's syndrome. The purpose of this study is to summarize our experience with the use of this procedure and a three fourths partial tendon transposition modification of this procedure for a variety of complex vertical and horizontal paralytic eye movement disorders. DESIGN: Retrospective noncomparative interventional consecutive case series. PARTICIPANTS: Eighteen patients with paralytic strabismus. INTERVENTION: Full tendon rectus muscle transposition procedure augmented with posterior fixation sutures (13 patients) or a three fourths partial tendon transposition augmented with posterior fixation sutures (5 patients). MAIN OUTCOME MEASURES: Resolution of diplopia in the primary position and improved ocular alignment. RESULTS: Comparing preoperative to postoperative status, presence of primary position diplopia decreased from 64% to 14%, anomalous head posture decreased from 56% to 6%, and primary position alignment improved in all patients. CONCLUSIONS: Full tendon rectus muscle transposition surgery augmented with posterior fixation sutures and the vessel-sparing three fourths partial tendon transposition modification of this technique are effective for the treatment of a variety of complex vertical and horizontal paralytic ocular motility disorders.

Adolescent↗
PubMedDate not supplied

Generation of a telomere-based episomal vector.

We have developed a telomere-based episome by large-scale amplification in Escherichia coli cells. This episome consists of a PAC vector in which a 6 Kb sequence, containing an array of telomeric repeats spaced by a synthetic sequence, is tandemly repeated by large-scale multimerization in E. coli. After transfection in human HT1080 cells, the construct, called clone 106, was able to persist in episomal form or integrated into some endogenous chromosomes. Integrations occurred exclusively at the telomeres. Episomes were still present in HT1080 cells after more than 100 days in the absence of selection. Integrations of clone 106 into the telomeric regions were retained only under selective conditions, and when the selection was removed the construct was progressively eliminated from the chromosome. The long-term maintenance of clone 106 into human cells as an episome and its ability to integrate transiently into the telomeres of the host chromosomes suggest that this PAC-based episome is potentially a good candidate vector for gene therapy applications.

Cell Line, Tumor↗