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Biomedical subjects

L Dalton

Publications and source records attributed to L Dalton.

13 recordsLinked to original sources
PubMed2003

Rural general practitioner preceptors--how can effective undergraduate teaching be supported or improved?

INTRODUCTION: General practitioners (GPs) as rural GP-Preceptors play an important role in medical student teaching within the Discipline of General Practice, University of Tasmania, Australia. As well a significant teaching role, they are responsible for apportioning 20% of the mark medical students receive in the General Practice examination at the end of the rotation. The contribution of the student-rural GP preceptor relationship to recruiting and retaining rural GPs has been acknowledged. Despite these important responsibilities, as honorary teaching staff rural GP preceptors receive no formal training in undergraduate education or assessment, nor did they receive formal peer support. METHOD: To address the lack of educational preparation of GP-preceptors, and in accordance with the stringent teaching and assessment standards of the Australian Medical School Accreditation, a tripartite approach was taken to educational skills development among rural GP-preceptors. The Discipline of General Practice conducted a needs-analysis of 64 rural GP-preceptors, and an evaluation by questionnaire of the teaching efficacy of those 64 rural GP-Preceptors and 76 urban GP-preceptors by 64 final-year medical students after their 3-week rural and urban GP attachments. The second intervention, based on the assessment and evaluation findings, was devised and implemented by the University Department of Rural Health. A series of workshops comprised the interdisciplinary educational and support program for GP preceptors, entitled Preceptor Onsite Preparation Program for Information Education and Support, or POPPIES. RESULTS: The rural GP-preceptor needs analysis indicated that the majority of rural preceptors had no clear understanding of how what they taught fitted into the overall curriculum; they believed that their role as a clinical teacher had not been clearly defined by the program director; and also that undergraduate students had little understanding of what they needed to learn during their attachments. In contrast, preceptors believed they understood what students needed to learn; they were confident in performing the role of preceptor; and were familiar with adult learning principles, goal setting processes, effective student evaluation and the provision of appropriate performance feedback. Evaluation of feedback from students revealed that while rural GP preceptors performed well overall in regard to providing quality teaching and learning experiences, there was a significant spread of scores across all criteria, and approximately 15%-25% of students perceived various aspects of their attachment to be mediocre or poor. CONCLUSION: The combined results of the medical student questionnaire and rural GP-preceptor survey indicated both a need and a desire for educational skills development among rural GP-preceptors. On this basis, the interdisciplinary educational and support program for GP-preceptors (POPPIES) was developed and implemented as a series of workshops throughout rural Tasmania. Although no objective data are yet available about teaching outcomes as a result of POPPIES workshops, preliminary responses from attendee GP preceptors indicated that the workshops were effective in addressing educational needs, and in providing rural clinical teachers with professional teaching development.

Journal Article↗
PubMed2002

Opening farm gates: community as educator.

This paper presents the experience of five undergraduate Bachelor of Nursing students who undertook a clinical practice placement in a rural community. This, our first engagement with nursing, was a profound learning experience. We did not expect the intense contributions the rural community as a whole would make to our understandings of rural health care in general, and rural nursing in particular. Initially, we felt like outsiders to the rural community as well as the profession of nursing. The interwoven nature of community relationships combined with our acute sense of being highly visible in the township led to us developing a sense of vulnerability. We believed we needed to portray a professional image during all social interactions with the community and this compounded our insecurities during the clinical placement. Before long, we found the rural population embracing and very supportive of our placement. However, we found ourselves questioning whether we would return to a rural community to work as nurses on the basis of our lack of privacy during this time.

Journal Article↗
PubMed1990

The area of cancer in transurethral resection specimens as a prognostic indicator in carcinoma of the prostate: a computer-assisted morphometric study.

We used a computerized interactive morphometric method to determine total area of tissue and total area of cancer in routinely stained sections from each of 79 cases of prostatic adenocarcinoma, diagnosed by transurethral resection (TURP). The ability of two morphometrically determined parameters (area of cancer and percent area of cancer) to predict survival was compared with results obtained from two estimates of tumor area commonly used in clinical practice (number of chips and percent of chips involved by cancer). Total Gleason score was also determined. All patients were diagnosed prior to 1981, allowing follow-up of at least 5 years, or until death. Using the Cox proportional hazards regression analysis, our two morphometrically determined parameters, as well as the percentage of chips involved by cancer and total Gleason score, were significant predictors of survival. In contrast, the total number of chips involved by cancer did not reach statistical significance as a predictive factor for survival. By using our morphometrically determined area measurements as a bench mark for clinical utility of area estimates of cancer in TURP specimens, we concluded that calculating the percentage of involved chips yields prognostic information that closely approaches the "ideal" of these more time-consuming computer-assisted techniques.

Adult↗
PubMed1986

Variation of nonexchangeable proton resonance chemical shifts as a probe of aberrant base pair formation in DNA.

Variation of nonexchangeable proton resonance chemical shifts for deoxycytidine and deoxy-adenosine as a function of protonation and imino tautomer formation has been determined. Protonation induces downfield shifts of proton resonances whereas formation of the rare imino tautomer induces upfield shifts. Titration curves are constructed on the basis of spectrophotometrically determined pK values. Excellent fit is obtained between theoretical titration curves and experimental data, which indicates that chemical shifts of base protons may be used to quantitatively determine the relative concentrations of either rare imino tautomeric conformations or protonated base forms. These data may be utilized as an aid in the elucidation of the nature of hydrogen bonding between mismatched base pairs in DNA oligomers containing cytosine or adenine residues. These data, in conjunction with the oligonucleotide study of Patel et al. [Patel, D. J., Kozlowski, S.A., Ikuta, S., & Itakura, K. (1984) Biochemistry 23, 3218-3226], have been used to rigorously argue the existence of a "protonated" adenine residue in the A-C mismatch. This structure allows reconciliation of the NMR solution data with crystallographic data [Hunter, W.N., Brown, T., Anand, N.N., & Kennard, O. (1986) Nature (London) 320, 552-555], which support the protonated base pair.

Base Composition↗
PubMed1983

Heterologous immunity in rodent malaria: comparison of the degree of cross-immunity generated by vaccination with that produced by exposure to live infection.

The degree of heterologous immunity occurring between the different rodent malarias was examined. Mice immunized with a killed vaccine consisting of formalin-fixed blood-stage parasites mixed with saponin, were challenged with homologous or heterologous parasites and the degree of protection assessed by monitoring the number of survivors and the duration and severity of parasitaemia. The results indicated that vaccination conferred strong cross-protection between two different Plasmodium yoelii lines and also some cross-protection between different species. The most significant inter-species cross-immunity was in P. berghei-vaccinated mice challenged with P. yoelii (33% survival rate) and in P. vinckei-vaccinated mice challenged with P. chabaudi (50% survival rate). The protection operated only in one direction since mice vaccinated against P. yoelii or P. chabaudi were fully susceptible to P. berghei and P. vinckei respectively, although extension of the survival time did occur in both cases. Significantly greater levels of homologous and heterologous immunity occurred in vaccinated mice which had cleared a primary homologous infection. All recovered animals were fully resistant to homologous secondary challenges. P. berghei-recovered mice had complete resistance to a secondary P. yoelii challenge, with partial resistance also to P. vinckei and P. chabaudi: P. vinckei-recovered mice were completely resistant to P. chabaudi challenge and showed partial resistance to P. berghei (50% survival rate). Conversely, no reduction in mortality occurred in P. chabaudi-recovered mice challenged with any heterologous parasite. Plasmodium yoelii-recovered animals were fully susceptible to P. vinckei but showed some resistance to P. berghei and P. chabaudi (33 and 17% survival respectively). Many lesser instances of cross-resistance were observed in the present study and are discussed in the text but they were not sufficiently powerful to reduce mortality. The present study provides the first reported comprehensive investigation on cross-resistance in rodent malarias generated by a killed vaccine. In addition this is the only complete cross-resistance study available which has concentrated exclusively upon highly lethal strains of each parasite species. Taken with the rechallenge experiments, the results extend, and to a certain point confirm, previous observations on cross-immunity in the rodent malarias. However, several of the present results conflict with previous reports and these are discussed in relation to the relevant literature.

Animals↗
PubMed1982

Antipsychotic effects of pimozide in schizophrenia. Treatment response prediction with acute dextroamphetamine response.

Acute behavioral response to 20 mg of dextroamphetamine (intravenous) predicted fourth-week antipsychotic response to double-blind pimozide treatment. Patients whose psychotic condition improved with dextroamphetamine administration showed more antipsychotic response to pimozide therapy than those whose condition worsened or did not change. Multiple regression analysis indicated amphetamine-induced response predicted pimozide response after four weeks for fifth-week pimozide response was more accurately predicted by prepimozide psychosis ratings. Our study provides some evidence that mechanisms underlying early and late pimozide response are not necessarily identical. Because patients who did not respond to dextroamphetamine administration still improved with pimozide therapy, our data do not support the concept that schizophrenia can be divided into two groups (dopamine-sensitive or dopamine-insensitive) but, rather, that dopamine responsiveness changes over time. Clinical application is not warranted until studies with larger samples have replicated our findings.

Adolescent↗
PubMed1982

Fluorocarbon emulsions: methodology to assess efficacy.

The fluorocarbon emulsion Fluosol-DA (20%) is an acellular O2 carrier that has potential as a red cell substitute. Clinical evaluation of efficacy requires knowledge of the ability of the perfluorochemical (pfc) phase to both load and unload O2. A method is described to measure the oxygen dissolved in the pfc and aqueous phases, and the oxygen chemically bound to hemoglobin, during use of this drug. These O2 contents are used to calculate the contribution of the pfc phase to total O2 delivery and O2 consumption (VO2) and the fractional extraction of O2 in the pfc phase. The technique requires a blood gas analyzer, a microhematocrit centrifuge, and a standard co-oximeter found in many blood gas laboratories. This technique appears to be simple and reliable, and should facilitate the evaluation of efficacy of fluorocarbon emulsions.

Animals↗
PubMed1982

A comparison of saponin with other adjuvants for the potentiation of protective immunity by a killed Plasmodium yoelii vaccine in the mouse.

The protective immunity conferred by subcutaneous injection of outbred CD-1 mice with a killed Plasmodium yoelii (YM strain) vaccine was strongly potentiated by saponin. By adjusting the dose of antigen, the number of immunizations and the number of living parasites in the challenge infection, conditions were defined where antigen alone was non-protective but 100% protection was obtained by the addition of saponin. Inbred BALB/c, CBA/CA and C57 B1 mice were much less responsive than the CD-1 mice. The following adjuvants were compared with saponin: mineral oil emulsions (Freund's incomplete and complete adjuvants); A1(OH)3(Alhydrogel); bacteria and synthetic bacterial derivatives (Bordetella pertussis, Corynebacterium parvum and muramyl dipeptide); surface active materials (digitonin, vitamin A, Arquad 18, dimethyldioctadecyl ammonium bromide, and the polyene antibiotics, Nystatin and Amphotericin B). None of these adjuvants were as effective as saponin, although FCA, A1(OH)3 and C. parvum augmented immunity considerably. The possible reasons for the efficacy of saponin as an adjuvant for protozoal vaccines are discussed. The P. yoelli/mouse system provides a sensitive and rapid screening assay for comparison of potential adjuvants suitable for use with a malaria vaccine.

Adjuvants, Immunologic↗