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Biomedical subjects

D Simpson

Publications and source records attributed to D Simpson.

At least 73 records · Page 4Linked to original sources
PubMed2001

Accuracy of sentinel lymph node biopsy for patients with T2 and T3 breast cancers.

Although numerous studies have demonstrated that sentinel lymph node (SLN) biopsy can accurately determine the axillary nodal status for early breast cancer some studies have suggested that SLN biopsy may be less reliable for tumors >2 cm in size. This analysis was performed to determine whether tumor size affects the accuracy of SLN biopsy. The University of Louisville Breast Cancer Sentinel Lymph Node Study is a prospective multi-institutional study involving 226 surgeons. The study was approved by the Institutional Review Board of each institution, and informed consent was obtained from all patients. Patients with clinical stage T1-2 N0 breast cancer were eligible for the study. Some patients with T3 tumors were included because they were clinically staged as T2 but on final pathology were found to have tumors >5 cm. This analysis includes 2148 patients who were enrolled from August 1997 through October 2000. All patients underwent SLN biopsy using a combination of radioactive colloid and blue dye injection followed by completion Level I/II axillary dissection. Statistical comparison was performed by chi-square analysis. The SLN identification rate, false negative rate, and overall accuracy of SLN biopsy were not significantly different among tumor stages T1, T2, and T3. We conclude that SLN biopsy is no less accurate for T2-3 breast cancers compared with T1 tumors.

Breast Neoplasms↗
PubMed2001

Age-specific incidence of cancer in Kingston and St Andrew, Jamaica, 1993-1997.

A total of 4285 malignant neoplasms were recorded in Kingston and St. Andrew during the period 1993-1997, 2344 in females and 1941 in males. The crude incidence rate per 100,000 (CIR) for males was 121.6 and for females 129.2. Age standardized rates per 100,000 (ASR) were 156.7 and 176.7 for males and females respectively. In males, the leading sites for cancer were prostate (619 cases), bronchus (265 cases) and large bowel (144 cases) while in females the leading sites were breast (627 cases) cervix uteri (376 cases) and large bowel (204 cases). The crude and age standardized incidence rates have remained stable as compared to those for the previous five year period (1998-1992). The leading sites for both males and females have also been maintained in the same order but there was a marked increase in prostate cancer (ASR 56.4 versus 36). Invasive cervical cancer has shown no significant change in incidence (ASR 25.2 versus 26.3) but the rate for in-situ cancers has decreased (ASR 27.4 versus 43.8). The incidence of cancer of the female breast has remained relatively stable (ASR 43.2 versus 47.1). The trends exhibited by both prostate cancer and in-situ cervical cancer probably represent the influence of screening methods for prostate cancer and ablative management for low grade dysplastic lesions of the cervix uteri respectively.

Adult↗
PubMed2000

AIDS myelopathy is not associated with elevated HIV viral load in cerebrospinal fluid.

The pathogenesis of AIDS-associated myelopathy is unknown. Elevated HIV-1 viral load in CSF has been associated with cognitive impairment. The authors investigated if a similar association exists in patients with myelopathy. The authors evaluated levels of HIV-1 RNA in the CSF of 16 individuals with AIDS myelopathy and in 16 nonmyelopathic HIV-infected control subjects. There was no correlation between levels of HIV-1 RNA and the presence or severity of myelopathy.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Ecology. The value of nature and the nature of value.

Ecosystems are capital assets: When properly managed, they yield a flow of vital goods and services. Relative to other forms of capital, however, ecosystems are poorly understood, scarcely monitored, and--in many important cases--undergoing rapid degradation. The process of economic valuation could greatly improve stewardship. This potential is now being realized with innovative financial instruments and institutional arrangements.

Australia↗
PubMed2000

Modelling stomatal ozone flux across Europe.

A model has been developed to estimate stomatal ozone flux across Europe for a number of important species. An initial application of this model is illustrated for two species, wheat and beech. The model calculates ozone flux using European Monitoring and Evaluation Programme (EMEP) model ozone concentrations in combination with estimates of the atmospheric, boundary layer and stomatal resistances to ozone transfer. The model simulates the effect of phenology, irradiance, temperature, vapour pressure deficit and soil moisture deficit on stomatal conductance. These species-specific microclimatic parameters are derived from meteorological data provided by the Norwegian Meteorological Institute (DNMI), together with detailed land-use and soil type maps assembled at the Stockholm Environment Institute (SEI). Modelled fluxes are presented as mean monthly flux maps and compared with maps describing equivalent values of AOT40 (accumulated exposure over threshold of 40 ppb or nl l(-1)), highlighting the spatial differences between these two indices. In many cases high ozone fluxes were modelled in association with only moderate AOT40 values. The factors most important in limiting ozone uptake under the model assumptions were vapour pressure deficit (VPD), soil moisture deficit (for Mediterranean regions in particular) and phenology. The limiting effect of VPD on ozone uptake was especially apparent, since high VPDs resulting in stomatal closure tended to co-occur with high ozone concentrations. Although further work is needed to link the ozone uptake and deposition model components, and to validate the model with field measurements, the present results give a clear indication of the possible implications of adopting a flux-based approach for future policy evaluation.

Journal Article↗
PubMed2000

English roots of medical education in Australasia: Kenneth F. Russell memorial lecture.

Some individuals have a heightened perception of history. K. F. Russell was one of these gifted people, and he wrote many books and papers on historical subjects. Two are classics: his history of the Melbourne medical school and his catalogue of the historical books in the library of the Royal Australasian College of Surgeons. Among the books catalogued by Russell is a small work by James Paget entitled Records of Harvey: In Extracts from the Journals of the Royal Hospital of St Bartholomew. This book recalls Paget's career as a teacher and reformer in medical education during the second half of the 19th century, and also his role in drafting a model curriculum for Australia's first university medical school, in Melbourne. Medical education in Melbourne and Adelaide was largely moulded by Paget and other leading London teachers. Cambridge was also influential in Adelaide. Scottish influences were stronger in Dunedin and Sydney. In the two decades before World War I, many graduates from these new medical schools went to Britain for postgraduate experience. They were assisted by British educational institutions inspired by the contemporary ideology of imperialism.

Australia↗
PubMed2000

Drug therapy for acute graft-versus-host disease prophylaxis.

The mechanisms of many immunosuppressive drugs have been defined, allowing for a rational approach to the use of these agents in GVHD prophylaxis. In addition to standard drugs such as methotrexate, cyclosporine, tacrolimus, and glucocorticoids, new agents-mycophenolate mofetil, tresperimus, rapamycin, basiliximab, and daclizumab-are now part of the immunosuppressive armamentarium. Improved understanding of tolerance has resulted in new approaches to prevention of GVHD. Anti-CD40L, CTLA-4-Ig, tresperimus, and rapamycin are agents that are being explored in this area and have shown impressive results in animal models. Currently, the standard therapy for acute GVHD prophylaxis in matched sibling transplants remains cyclosporine and methotrexate. Lower dose methotrexate, particularly in combination with tacrolimus, has shown good results in single arm studies with low toxicity, but this has not been tested in a randomized study. For unrelated donor transplants there is less GVHD when tacrolimus, rather than cyclosporine, is combined with methotrexate; there seems little reason to use cyclosporine in this setting. GVHD is still the major barrier to more widespread use of unrelated donor transplants and improved regimens are needed. In vivo T-cell depletion using Campath-1 or ATG is being used in high-risk patients. Data on its efficacy are so far anecdotal. Due to the variation in grading of GVHD between centers, randomized studies are needed to quantify the relative merits of different regimens, and participation in such studies is encouraged.

Acute Disease↗