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G MacLachlan

Publications and source records attributed to G MacLachlan.

6 recordsLinked to original sources
PubMed2003

Measurements of GnE/GnM from the 2H(e-->,en-->)1H Reaction to Q2=1.45 (GeV/c)2.

We report new measurements of the ratio of the electric form factor to the magnetic form factor of the neutron, G(n)(E)/G(n)(M), obtained via recoil polarimetry from the quasielastic 2H(e-->,e(')n-->)1H reaction at Q2 values of 0.45, 1.13, and 1.45 (GeV/c)(2) with relative statistical uncertainties of 7.6% and 8.4% at the two higher Q2 points, which points have never been achieved in polarization measurements.

Journal Article↗
PubMed2000

Sugar-nucleotide-binding and autoglycosylating polypeptide(s) from nasturtium fruit: biochemical capacities and potential functions.

Polypeptide assemblies cross-linked by S-S bonds (molecular mass>200 kDa) and single polypeptides folded with internal S-S cross-links (<41 kDa) have been detected by SDS/PAGE in particulate membranes and soluble extracts of developing cotyledons of nasturtium (Tropaeolum majus L.). When first prepared from fruit homogenates, these polypeptides were found to bind reversibly to UDP-Gal (labelled with [(14)C]Gal or [(3)H]uridine), and to co-precipitate specifically with added xyloglucan from solutions made with 67% ethanol. Initially, the bound UDP-[(14)C]Gal could be replaced (bumped) by adding excess UDP, or exchanged (chased) with UDP-Gal, -Glc, -Man or -Xyl. However, this capacity for turnover was lost during incubation in reaction media, or during SDS/PAGE under reducing conditions, even as the glycone moiety was conserved by autoglycosylation to form a stable 41 kDa polypeptide. Polyclonal antibodies raised to a similar product purified from Arabidopsis bound to all the labelled nasturtium polypeptides in immunoblotting tests. The antibodies also inhibited the binding of nasturtium polypeptides to UDP-Gal, the uptake of UDP-[(14)C]Gal into intact nasturtium membrane vesicles and the incorporation of [(14)C]Gal into nascent xyloglucan within these vesicles. This is the first direct evidence that these polypeptides facilitate the channelling of UDP-activated sugars from the cytoplasm through Golgi vesicle membranes to lumenal sites, where they can be used as substrates for glycosyltransferases to synthesize products such as xyloglucan.

Antibodies↗
PubMed1999

Recurrence and survival after surgical management of rectal cancer.

BACKGROUND: Reported local recurrence rates for rectal cancer are significantly reduced using a combination of superior surgical technique, in the form of total mesorectal excision, and routine radiotherapy. In an attempt to determine the effectiveness of current local management strategies, a review of Vancouver Island Cancer Centre patients with rectal cancer was performed and the overall local recurrence rate was identified. METHODS: We retrospectively reviewed the charts of 272 rectal cancer patients from 1988 to 1998. Two hundred and twenty-nine patients met inclusion criteria. Analysis of patient factors included age, gender, type of surgery, and adjuvant therapy. Tumors were assessed for level, stage, and grade. Local recurrence and distant metastases were also documented. Variables influencing local recurrence in this group were identified and disease-free and actuarial survival determined. RESULTS: Of 229 patients analyzed, 12.7% (29) had local recurrences. Variables influencing local recurrence were number of positive lymph nodes, vascular invasion, and neural invasion. There was no significant difference in local recurrence between patients having anterior resection and those having abdominoperineal resection. None of the patients who received preoperative radiotherapy had a local recurrence. Actuarial disease-free survival was 87% at 5 years. CONCLUSIONS: Limiting local recurrence is one of the most important goals in the treatment of rectal cancer. It is essential to identify those patients with "high risk" tumors as identified by endorectal ultrasound or pathologic features. These patients comprise the group most likely to benefit from a routine mesorectal excision combined with adjuvant radiotherapy.

Aged↗
PubMed1993

Ifs and butts.

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Attitude to Health↗
PubMed1989

Influence of cyclosporin A and alpha-difluoromethylornithine, an inhibitor of polyamine biosynthesis, on two rodent T-cell cancers in vivo.

We have examined the influence of cyclosporin A (CsA), administered together with the polyamine antimetabolite, alpha-difluoromethylornithine (DFMO), on growth of the Roser acute T-cell leukaemia in PVG rats and on growth of the EL4 lymphoma in C57BL/6 mice. CsA or DFMO alone, administered from the time of tumour injection, markedly reduced numbers of circulating lymphoblasts in leukaemic rats, although survival was prolonged only in those animals given DFMO. Drug combination further reduced blood-borne tumour cells, but had no additional effects on tumour growth within organs or on host survival, compared to that achieved with DFMO treatment alone. Neither CsA nor DFMO, administered from the time of tumour-cell injection, nor both drugs in combination, affected peritoneal growth of the EL4 lymphoma or organ infiltration. Host survival was prolonged by DFMO. As anticipated, DFMO inhibited polyamine synthesis in vivo, but the observed anti-tumour effect of CsA was not accompanied by an alteration in polyamine biosynthesis. By reducing polyamine synthesis, however, DFMO may enhance the vulnerability of those malignant T cells which are susceptible to the as yet unexplained selective inhibitory action of CsA in vivo.

Animals↗