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Biomedical subjects

W Jack

Publications and source records attributed to W Jack.

14 recordsLinked to original sources
PubMed2004

Diagnostic delay in breast cancer.

BACKGROUND: Delay in the diagnosis of breast cancer has important clinical and medicolegal implications. This study assessed the frequency, causes and effects of delay in the diagnosis of breast cancer in a specialist breast unit. METHODS: Details of women who attended the breast clinic between 1988 and 1999 inclusive, and for whom the interval between first attendance and diagnosis of invasive breast cancer was greater than 2 months, were reviewed. Potential causes of delay were identified and the consequence of the delay assessed. The clinical features were compared with those of patients diagnosed with breast cancer during a 2-year period from 1999 and 2001. RESULTS: Breast cancer was diagnosed in 5283 women during the interval reviewed; delay in diagnosis was suggested in 72 women (1.4 per cent). Women with a delayed diagnosis were younger (P < 0.001) and had a smaller tumour at diagnosis (P = 0.011) compared with all women diagnosed with breast cancer between 1999 and 2001. There were no differences in the rate of axillary node positivity or the need for mastectomy. Women unsuitable for conservation therapy in the delayed group had a significantly longer interval to diagnosis (P = 0.006). CONCLUSION: The likelihood that conservation therapy will be appropriate is reduced when the hospital delay in the diagnosis of breast cancer is more than 240 days. All patients with a palpable mass require triple assessment to minimize delay in diagnosis of breast cancer.

Adult↗
PubMed2001

The public economics of tuberculosis control.

This paper identifies specific sources of the failure of private markets to allocate TB control resources efficiently. These market failures, as well as the concentration of the disease amongst the poor, suggest a number of roles for public intervention. Government intervention should aim to either increase, add to, or substitute for private supply, depending on the type of market failure and the institutional capacity of the public sector.

Communicable Disease Control↗
PubMed2001

What is the evidence for a reduced risk of local recurrence with age among older patients treated by breast conserving therapy?

With the rising age of the population and the proposed extension of the breast screening programme to older women, increasing numbers of older patients are becoming eligible for breast conserving surgery and post-operative breast irradiation. Women over the age of 70 have traditionally been omitted from randomized controlled trials for assessing the role of breast radiotherapy after local surgery. The majority of trials suggest that local recurrence rates do decline with age. Similar conclusions are suggested by many non-randomized studies. Comparison of randomized and non-randomized studies is limited by differing extent of classifying tumour margins, nodal status, use of adjuvant systemic therapy, sample size, analytical approaches and duration of follow-up. Large randomized trials in older women are needed to assess whether, with careful attention to obtaining clear tumour margins, radiotherapy is required in low risk, ER positive, node negative breast cancer patients following wide excision and adjuvant tamoxifen. Within both randomized and non-randomized studies, only a few studies have failed to demonstrate an impact of age on recurrence rates following breast conserving treatment, with the majority finding a reduction in local recurrence rates with increasing age. Importantly for interpretation, no studies suggest that recurrence rates increase with age. The variation in analytical approaches and sample sizes are such that the variety of conclusions is not surprising. The results are compatible with a tendency for local recurrence rates to fall with age, but the variability is such that one cannot quantify this change with any precision.

Journal Article↗
PubMed2000

Public spending on health care: how are different criteria related? A second opinion.

A natural response to difficult questions is to increase the number of objectives one pursues in the hope that each of them separately will be easy to satisfy. This note critically evaluates this strategy as employed in a recent paper in this journal [Musgrove, Health Policy 1999;47:207-223], especially its evaluation of the role of cost-effectiveness in priority setting in the health sector. It is suggested that cost-effectiveness measures provide information of limited use, and that the tools of applied welfare economics are sufficient to guide the policy choices addressed in the paper. Students of health economics and health policy makers would do well to be exposed to these tools.

Cost-Benefit Analysis↗
PubMed2000

Management of the axilla in operable breast cancer treated by breast conservation: a randomized clinical trial. Edinburgh Breast Unit.

BACKGROUND: In the treatment of operable breast cancer by breast conservation, the extent of axillary dissection, the need for radiotherapy to the axilla and the morbidity associated with these procedures have not been assessed adequately. METHODS: Patients with operable breast cancer were randomized to have level III axillary node clearance (232 patients) or axillary node sample (234 patients). Radiotherapy to the axilla was given selectively. Radiotherapy was not given to those who had an axillary clearance. In the early part of the study all patients who had node sample were treated by radiotherapy (54 patients); subsequently this was modified to include only those who were node positive. The morbidity to the shoulder and arm was assessed before and after operation by measuring upper limb volume and circumference, and combined glenohumeral and scapular movement and muscle power. RESULTS: Comparing the two surgical policies, no difference was found in local (axillary clearance 14 versus sample 15), axillary (eight versus seven) or distant (29 versus 29) recurrence. There was no statistically significant difference in 5-year survival rate (clearance 82.1 versus sample 88.6 per cent). Morbidity was least in those who had a node sample and no radiotherapy to the axilla. Radiotherapy to the axilla in patients who had a node sample resulted in a significant reduction in range of movement of the shoulder, e.g. mean(s.e.) 2.2(0.6) cm reduction in lateral rotation at 3 years. Surgical axillary clearance was associated with significant lymphoedema of the upper limb, e.g. 4.1(0.7) per cent increase in arm volume at 3 years. CONCLUSION: A selective policy for the management of the axilla is associated with no increase in axillary recurrence or mortality rate compared with routine axillary node clearance. Patients who are node negative after axillary sample can avoid radiotherapy or axillary clearance.

Aged↗
PubMed1996

High-dose chemotherapy supported by peripheral blood progenitor cells in poor prognosis metastatic breast cancer--phase I/II study. Edinburgh Breast Group.

Current treatments for metastatic breast cancer are not associated with significant survival benefits despite response rates of over 50%. High-dose therapy with autologous bone marrow transplantation (ABMT) has been investigated, particularly in North America, and prolonged survival in up to 25% of women has been reported, but with a significant treatment-related mortality. However, in patients with haematological malignancies undergoing autologous transplantation, haematopoietic reconstruction is significantly quicker and mortality lower than with ABMT, when peripheral blood progenitor cells (PBPCs) are used. In 32 women with metastatic breast cancer, we investigated the feasibility of PBPC mobilisation with high-dose cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) after 12 weeks' infusional induction chemotherapy and the subsequent efficacy of the haematopoietic reconstitution after conditioning with melphalan and either etoposide or thiotepa. PBPC mobilisation was successful in 28/32 (88%) patients, and there was a rapid post-transplantation haematopoietic recovery: median time to neutrophils > 0.5 x 10(9) l-1 was 14 days and to platelets > 20 x 10(9) l-1 was 10 days. There was no procedure-related mortality, and the major morbidity was mucositis (WHO grade 3-4) in 18/32 patients (56%). In a patient group of which the majority had very poor prognostic features, the median survival from start of induction chemotherapy was 15 months. Thus, PBPC mobilisation and support of high-dose chemotherapy is feasible after infusional induction chemotherapy for patients with metastatic breast cancer, although the optimum drug combination has not yet been determined.

Adult↗
PubMed1994

Expression, purification, and crystallization of restriction endonuclease PvuII with DNA containing its recognition site.

We have overexpressed the type II restriction endonuclease PvuII (R-PvuII) in E. coli, prepared large amounts of the homogeneous enzyme, and crystallized it with an oligonucleotide carrying a PvuII recognition site. The cocrystals are orthorhombic space group P2(1)2(1)2(1) with cell constants a = 95.8 A, b = 86.3 A, c = 48.5 A, and diffract X-rays to at least 2.7 A. There is a complex of two protein subunits and one oligonucleotide duplex in the asymmetric unit.

Base Sequence↗
PubMed1993

Tumour cyclic AMP binding proteins: an independent prognostic factor for disease recurrence and survival in breast cancer.

In two separate cohorts of breast cancer patients presenting without evidence of distant metastatic disease, high levels of tumour cyclic AMP binding proteins (> 8 pmol/mg cytosol protein) have been shown to be associated with poor prognosis in terms of both disease recurrence and overall survival. This association is independent of known established prognostic factors and allows the identification of a small subgroup of patients whose outlook warrants the implementation of aggressive systemic therapy.

Breast Neoplasms↗
PubMed1990

Influence of naftidrofuryl, a serotonergic antagonist, on erythrocyte aggregation.

Erythrocyte aggregation is an important determinant of the rheological behavior of blood and may play a critical role in nutritive tissue perfusion at the level of the microcirculation, particularly in situations of low flow. Thus, abnormal red blood cell aggregation may contribute to the pathophysiology of a variety of vascular diseases with associated microcirculatory disturbances. The action of serotonergic antagonists has a hemorheological component, although red blood cell aggregation specifically has not been addressed previously. Therefore, the effect of naftidrofuryl, a 5-hydroxytryptamine-2 receptor antagonist (5-HT2), on erythrocyte aggregation was studied in whole blood obtained from adult human volunteers. Red blood cell aggregation was measured using a Myrenne aggregometer the operation of which is based on nephelometric principles. The results demonstrate that red blood cell aggregation is significantly reduced in comparison to controls on incubation of whole blood in the presence of naftidrofuryl. This inhibitory effect is concentration dependent and reaches a maximum (approximately 30%) between 1 and 10 microM naftidrofuryl. Furthermore, naftidrofuryl (5 microM) also inhibits red blood cell aggregation in the presence of exogenously added serotonin (1 microM) on average by approximately 18%. Significant inhibition of red blood cell aggregation could not be observed in similar experiments using whole blood suspensions essentially devoid of platelets, suggesting that these blood cellular elements are involved in mediating the effects of naftidrofuryl.

Adult↗
PubMed1976

The oxidation of terminal D-galactofuranose residues of a galactan and a glycoprotein by a D-galactose oxidase preparation from Dactylium dendroides.

A galactan, isolated from the unicellular organism Prototheca zopfii, and a glycoprotein from a hyphal cell-wall fraction of the fungus Pithomyces chartarum have been oxidised by a D-galactose oxidase preparation from Dactylium dendroides. The oxidised polymers were subsequently reduced with sodium borotritide. The site of oxidation was identified as C-6 of non-reducing D-galactofuranosyl residues in both polymers.

Alcohol Oxidoreductases↗