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Biomedical subjects

I Bennett

Publications and source records attributed to I Bennett.

13 recordsLinked to original sources
PubMed2003

Parathyroid hormone venous sampling prior to reoperation for primary hyperparathyroidism.

BACKGROUND: The surgical cure rate for primary hyperparathyroidismis greater than 95%. For those who have recurrent or persistent disease, preoperative localization improves reoperation success rates. Selective parathyroid venous sampling (SPVS) for intact parathyroid hormone is particularly useful when non-invasive localization techniques are negative or inconclusive. METHODS: We present all known cases (n = 13)between 1994 and 2002 who had venous sampling for localization a tour institution prior to reoperation for recurrent or persistent primary hyperparathyroidism. Comparison was made with non-invasive localization procedures. Results of invasive and non-invasive localization were correlated with surgical findings. RESULTS: Of the nine reoperated cases, eight had positive correlations between SPVS and operative findings and histopathology. SPVS did not reveal the parathyroid hormone source in one case with negative non-invasive localization procedures. Comparisons between SPVS,computerized tomography (CT), and parathyroid scintigraphy (MIBI)as expressed in terms of true positive (TP), false positive (FP)and false negative (FN) were: SPVS - TP88.8%, FP 0%, FN 11.1%; CT - TP22.2%, FP 22.2%, FN 55.5%; and MIBI - TP33.3%, FP 0%, FN 66.6%. At least seven of the nine operated cases have been cured; another remained normocalcaemic 2 weeks after subtotal parathyroidectomy. CONCLUSION: In our institution SPVS has proven to be a valuable tool in cases with recurrent or persistent primary hyperparathyroidism and negative non-invasive localization procedures.

Adult↗
PubMed2002

Ultrasonic specimen radiography for non-palpable breast lesions.

A retrospective review of ultrasound guided breast excisional biopsies performed in a Surgical Unit of Princess Alexandra Hospital in 1998-99 was undertaken to assess the use of ultrasound specimen radiography. In this series a total of 55 localization biopsies were performed for impalpable lesions in 53 women. In 21 patients (38%), specimen ultrasound was used to confirm that the lesion in question had been excised, whereas for 34 lesions (62%), specimen X-ray was undertaken. In a total of six cases (10.9% overall) the radiographic abnormality was seen on ultrasound only. Real-time specimen sonography is a technique which is very appropriately utilized in conjunction with ultrasound guided excisions and can be easily performed either in the radiology department or the operative suite with minimal time delay. It could have particular application for lesions that are detected in younger women with dense breast parenchyma. The results of this review confirm specimen sonography to be a reliable technique.

Journal Article↗
PubMed1996

Confirmation of susceptibility locus on chromosome 13 in Australian breast cancer families.

Two major genes determining predisposition to breast cancer, termed BRCA1 and BRCA2, have been mapped to the long arms of chromosomes 17 and 13, respectively. Each locus is believed to account for approximately 40% of cases of familial breast cancer. We used linkage and haplotype analysis with simple tandem repeat polymorphisms at chromosomal bands 17q21 and 13q12 to determine the contribution of the BRCA1 and BRCA2 genes to predisposition to breast cancer in four Australian breast cancer kindreds, one of which had two male cousins with breast cancer. Surprisingly all families segregated a haplotype of markers on 13q and showed positive lod scores supporting linkage to BRCA2. In addition, haplotype analysis identified an informative recombination between D13S260 and D13S171 in one affected individual, which refines the localisation of BRCA2 to between D13S260 and D13S267; a distance of 2-3 cM. Tumours of the stomach and cervix, as well as melanoma and leukaemia/lymphoma also occur in these pedigrees but the numbers are too low to determine whether they may be significantly associated with BRCA2 carrier status. Our results confirm the existence of BRCA2 on the long arm of chromosome 13 and support previous findings that this locus is likely to confer risk in families with affected males. Furthermore, our observations suggest that the BRCA2 gene may also contribute to the development of other neoplasma.

Australia↗
PubMed1996

Screening protocol for Torulopsis (Candida) glabrata.

A screening test has been developed for the presumptive identification of Torulopsis (Candida) glabrata from other common clinical isolates of yeast-like fungi. An interlaboratory comparison of a protocol consisting of morphology on cornmeal Tween 80 agar and trehalose fermentation at 42 degrees C was successful in differentiating T. glabrata from other taxa that are frequent or possible clinical isolates. The screening results for 517 clinical yeast isolates, 241 of which were T. glabrata, were compared with their final identification via commercial systems (API20C Yeast Identification System [bioMERIEUX, Hazelwood, Mo.] and Rapid Yeast Identification Panel [Dade Microscan, Sacramento, Calif.]). The trehalose screening test has a sensitivity and a specificity of 97.8 and 95.8%, respectively, and a positive predictive value of 97.4% and a negative predictive value of 96.5%. Overall, the trehalose screen had an efficiency rating of 93.9% for ruling in or out T. glabrata. Since T. glabrata represents a substantial part of the workload in a clinical laboratory, a significant reduction in direct and indirect costs should be realized.

Candida↗
PubMed1994

Identification of a potentially radiosensitive subgroup among patients with breast cancer.

BACKGROUND: The description of genes and genetic syndromes, such as ataxia-telangiectasia, that predispose some women to breast cancer will provide greater insight into the genetic basis of cancer susceptibility. PURPOSE: Our goal was to establish cell lines from patients with breast and bladder cancers, to screen for enhanced levels of radiation-induced arrest in the G2 phase of the cell cycle such as is observed in ataxia-telangiectasia heterozygotes, and to correlate G2 arrest with other prognostic indicators of these cancers and in vivo radiosensitivity. METHODS: Epstein-Barr virus-transformed lymphoblastoid cells were established from 108 female patients with breast cancer and 24 age-matched female control subjects, and from 45 patients with bladder cancer and 18 age-matched control subjects. Cells were exposed to 3 Gy of gamma radiation, and the percentages of cells in G1 and G2 phases were determined at 18 and 24 hours after irradiation by fluorescence-activated cell sorter analysis. Postirradiation delay in G2 phase was determined by calculating the percentage of cells in G2 and by using the ratio G2/G1. RESULTS: When we determined the percentage of cells in G2 phase at 18 hours after irradiation in 108 lymphoblastoid cells from breast cancer patients, we observed an increase of between 3% and 38% in the number of cells in G2 phase in comparison with cells that were not irradiated. Comparison with previous G2-phase arrest data for ataxia-telangiectasia heterozygotes using a cutoff point at 29% delay demonstrated that 20% and 8% of the breast cancer cell lines of the case patients and control subjects, respectively, fell into that category (P < .001). At the same time after irradiation, it was not possible to distinguish between bladder cancer cell lines (7%) and those of the corresponding control group (6%). Assessment of radiation effects by G2/G1 ratio showed that 18% of the breast cancer patients and 8% of the control subjects were in the high range. When G2 arrest was correlated with other prognostic factors, we found that case patients with a greater G2 block were more likely to have had a family history of breast cancer (P < .006) and more aggressive tumors when assessed by number of involved lymph nodes (P < .002) and tumor size (P < .05). Furthermore, an adverse response to radiotherapy was observed in a group of patients with high G2 arrest. IMPLICATIONS: While the postirradiation increase in G2-phase arrest in cells from breast cancer patients observed in this study may indicate genetic heterozygosity for ataxia-telangiectasia, it might also reflect other genetic abnormalities important to breast cancer.

Adult↗
PubMed1991

6-(substituted methylene)penems, potent broad spectrum inhibitors of bacterial beta-lactamase. III. Structure-activity relationships of the 5-membered heterocyclic derivatives.

Sodium (5RS)-Z-6-(heterocyclylmethylene)penem-3-carboxylates (2) are a series of extremely potent inhibitors of bacterial beta-lactamases. A variety of 5-membered heteroaromatic derivatives have been prepared and structure-activity studies reveal a preferred substituent orientation. One of these derivatives, the 1-methyl-1,2,3-triazolyl compound (5m) is a more potent synergist of amoxycillin than clavulanic acid, sulbactam or tazobactam.

Amoxicillin↗