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Biomedical subjects

M Todd

Publications and source records attributed to M Todd.

At least 37 records · Page 2Linked to original sources
PubMed1993

Probing the effects of individual components in multiple component prevention programs.

Assessing the contributions of individual components in multi-component interventions poses complex challenges for prevention researchers. We review the strengths and weaknesses of designs and analyses that may be useful in answering three questions: (1) Is each of the individual components contributing to the outcome? (2) Is the program optimal? and (3), Through what processes are the components of the program achieving their effects? Factorial and fractional factorial designs in which a systematically selected portion of all possible treatment combinations is implemented are used to address question 1. Response surface designs in which each component is quantitatively scaled are explored in relation to question 2. Mediational analysis, a hybrid of experimental and correlational approaches, is considered in relation to question 3. Design enhancements are offered that may further strengthen some of these techniques. These techniques offer promise of enhancing both the basic science and applied science contributions of prevention research.

Combined Modality Therapy↗
PubMed1993

Differences between "geriatric" and "medical" patients aged 75 and over.

We analysed the characteristics of patients aged 75 and over admitted to the geriatric and general medical wards over a three month period in a teaching hospital. Patients admitted to the geriatric wards were slightly older, were more often female, more likely to be admitted during the day and during a week day, more likely to have been seen by their own general practitioner, had more chronic and multiple illness with non-specific presentations, and stayed longer in hospital. Referring doctors seem to discriminate between patients needing geriatric care and those more suitable for general medical care, but there is an overlap in the characteristics of the two groups.

Age Factors↗
PubMed1991

Reduction in local cerebral blood flow induced by endothelin-1 applied topically to the middle cerebral artery in the rat.

The role of endothelin-1 (ET-1) in cerebral ischemic injury remains the subject of much debate. Vasoconstriction in large conduit vessels may not be associated with reductions in flow at the tissue level. We present two studies examining the effects on local cerebral blood flow of topical application of ET-1 to the surgically exposed middle cerebral artery (MCA) in adult male Sprague-Dawley rats. In the first series using 14C-iodoantipyrine autoradiography, 10 min following application of ET-1 (1 nmol) to the MCA, up to 80% reduction in blood flow in the territory of distribution of the MCA is seen (e.g., dorsolateral caudate nucleus--flow reduced from 131 +/- 3 ml/100 g/min to 29 +/- 25 ml/100 g/min). These levels of flow are comparable with those seen with permanent bipolar diathermy occlusion and division of the proximal MCA--a standard rat model of focal cerebral ischemia. In a second series using hydrogen clearance technique for measurement of local cerebral blood flow in the caudate nucleus, we have shown that flow ipsilateral to application of ET-1 (0.25 nmol) is significantly reduced compared with saline controls for 80 min. Such reduction of flow, at the tissue level, sustained over this duration is consistent with the induction of ischemic cell damage by ET-1.

Administration, Topical↗
PubMed1990

Reduction of local cerebral blood flow to pathological levels by endothelin-1 applied to the middle cerebral artery in the rat.

Endothelin-1 (1 nmol) was applied to the exposed left middle cerebral artery (MCA) in anaesthetised adult male Sprague-Dawley rats. Local cerebral blood flow (1CBF), using [14C]iodoantipyrine and quantitative autoradiography, was measured in 27 anatomically defined structures, 10 min after topical application of endothelin-1. In those areas supplied by the MCA, 1CBF was markedly reduced beyond the threshold for ischaemic damage (e.g. dorsolateral caudate nucleus reduced from 131 +/- 3 to 29 +/- 25 ml.100 g-1.min-1, sensorimotor cortex from 109 +/- 5 to 31 +/- 21 ml.100 g-1.min-1). Distant areas were not affected.

Animals↗
PubMed1990

In search of the perfect assessment.

Assessment tools are essential in planning individual care for people with learning difficulties, but nurses often lack confidence in using them. This article looks at why this is, and discusses 10 commonly used tools.

Child↗
PubMed1989

Comparison of one dose cefazolin versus one dose cefotetan for cesarean section prophylaxis.

During one year, 646 women who delivered by cesarean section entered into a prospective randomized clinical trial to determine if a single intraoperative dose of cefazolin was as effective as cefotetan in the prevention of postoperative endomyometritis. Of 336 patients receiving 2 gm cefazolin intravenously at the time of clamping of the cord, endomyometritis developed in 30 (8.91%), and of 310 patients who received 2 gm cefotetan intravenously at the time of clamping of the cord, endomyometritis developed in 36 (11.6%). There was no statistically significant difference in the incidence of endomyometritis between the two groups (p = .269). We conclude that since the two drugs are equal in efficacy 2 gm of cefazolin is a cost effective method of prophylaxis for cesarean section.

Adolescent↗
PubMed1984

A follow-up of a randomized study comparing two chemotherapy treatments for advanced diffuse histiocytic lymphoma.

In 1976 we began a randomized study for the treatment of patients with stage III and IV diffuse histiocytic lymphoma. The therapy was either ACOMLA (doxorubicin, cyclophosphamide, vincristine [oncovin], methotrexate with leucovorin rescue, and cytarabine) or CHOP-B (cyclophosphamide, doxorubicin [hydroxydaunorubicin], vincristine [oncovin], prednisone, and bleomycin). A complete response (CR) was achieved in 13 (65%) of 20 patients treated with ACOMLA and in 20 (71%) of the 28 patients treated with CHOP-B. Four patients achieving CR with ACOMLA and three patients treated with CHOP-B have relapsed for an overall relapse rate of 21%. Partial response (PR) was obtained in four patients treated with ACOMLA and five patients treated with CHOP-B. Median follow-up time is 36 months for the combined treatment groups. Multiple regression analysis demonstrated that those patients who were classified by the Lukes-Collins criteria as having histiocytic lymphoma not of follicular center-cell origin (combined T- and B-cell immunoblastic sarcoma) had a significantly worse survival as compared to patients classified with follicular center-cell origin lymphoma (large cell noncleaved, large cell cleaved, and large cell unclassified) with a 40% five-year survival versus an 80% five-year survival (P = .011). The CR rate however for these two large categories of patients was 63% v 73% respectively, and the relapse rates were equivalent. The increased survival in the follicular center-cell origin lymphomas may be related to a longer survival of PRs and relapsed patients as compared to the patients with nonfollicular center-cell lymphomas.

Adolescent↗
PubMed1983

Survival of women with metastatic breast cancer at Yale from 1920 to 1980.

The tumor registry at Yale--New Haven Hospital, which began recording data in 1920, was utilized to examine the ultimate outcome of all breast cancer patients who were initially diagnosed at Yale with metastatic breast cancer. Of the 5,898 patients with breast cancer seen from 1920 to 1980, 574 initially had metastatic cancer. The median survival of these patients increased steadily from 21 months in 1920 to 41 months in the decade from 1970 to 1980. The percentage of women actually surviving 5 years increased from 5% in the 1920s to approximately 25% in the 1960s. Despite the use of combination drug programs in the 1970s, the percentage of these patients remaining alive at 5 years remained near 25%. Firm conclusions cannot be made from a retrospective study spanning 60 years, although the trends depicted and lack of continued improvement indicate that our current therapeutic approach to metastatic breast cancer may not result in dramatic improvement in overall survival.

Breast Neoplasms↗