Recharging Family Medicine: A Perspective from the Keystone IV Conference.

A historic perspective of family medicine's development, the work of Gayle Stephens, and prior Keystone conferences constitute an important backdrop for the fourth Keystone Conference. Decisions made in the past constrain what can be done now, but they may also offer opportunities for family medicine. A major challenge for Keystone IV was to discern what is a constraint and what is an opportunity-in particular when it comes to the role of the personal physician. This article provides reflections based on decades of observation and study and confirms that knowing something and doing something are not the same.

Palliative radiotherapy regimens for patients with thoracic symptoms from non-small cell lung cancer.

BACKGROUND: Palliative radiotherapy to the chest is often used in patients with lung cancer, but radiotherapy regimens are more often based on tradition than research results. This is an update of a Cochrane review first published in 2001 and previously updated in 2006. OBJECTIVES: The two objectives of this review were:1. To assess the effects of different palliative radiotherapy regimens on improving thoracic symptoms in patients with locally advanced or metastatic non-small cell lung cancer who are not suitable for radical RT given with curative intent.2. To assess the effects of radiotherapy dose on overall survival in patients with locally advanced or metastatic non-small cell lung cancer who are not suitable for radical RT given with curative intent. SEARCH METHODS: The electronic databases MEDLINE (1966 - Jan 2014), EMBASE and the Cochrane Central Register of Controlled Trials, reference lists, handsearching of journals and conference proceedings, and discussion with experts were used to identify potentially eligible trials, published and unpublished.Two authors (FM and RS) independently identified all studies that may be suitable for inclusion in the review.We updated the search up to January 2014. SELECTION CRITERIA: Randomised controlled clinical trials comparing different regimens of palliative thoracic radiotherapy in patients with non-small cell lung cancer. DATA COLLECTION AND ANALYSIS: The reviewers assessed search results independently and possible studies were highlighted and the full text obtained. Data were extracted and attempts were made to contact the original authors for missing information.The primary outcome measure was improvement in major thoracic symptoms (degree and duration). Secondary outcome measures were short and long term toxicities, effect on quality of life and overall survival.Patient reported outcomes were reported descriptively. Quantitative data such as survival and toxicity were analysed as dichotomous variables and reported using relative risks (RR).For this update of the review a meta-analysis of the survival data was carried out. MAIN RESULTS: Fourteen randomised controlled trials (3576 patients) were included, with no new studies added in this update.There were important differences in the doses of radiotherapy investigated, the patient characteristics including disease stage and performance status and the outcome measures.The doses of RT investigated ranged from 10 Gy in 1 fraction (10Gy/1F) to 60 Gy/30F over six weeks, with a total of 19 different dose/ fractionation regimens.Potential biases were identified in some studies. Methods of randomisation, assessment of symptoms and statistical methods used were unclear in some papers. Withdrawal and drop-outs were accounted for in all but one study.All 13 studies that investigated symptoms reported that major thoracic symptoms improved following RT.There is no strong evidence that any regimen gives greater palliation. Higher dose regimens may give more acute toxicity and some regimens are associated with an increased risk of radiation myelitis. Variation in reporting of toxicities, in particular the absence of clear grading, means results of the meta-analysis should be treated with caution.Meta-analysis of overall survival broken down by performance status, a key variable, is included in this update. Further information was sought from all the original authors if stratified data was not included in the original publication. Three published studies contained sufficient data and seven authors were able to provide further information which represented 1992 patients (56% of all patients). The absence of data for nearly half of the patients has affected the quality of evidence.The meta-analysis showed no significant difference in 1-year overall survival between regimens with fewer radiotherapy fractions compared with regimens with more when patients were stratified by performance status. The results of the meta-analysis of 1-year overall survival for patients with good performance status (WHO performance status 0-1) showed moderately high heterogeneity and a summary result was not thought meaningful. The results of 1-year overall survival for patients with poor performance status was RR 0.96 (95% CI 0.91 to 1.02; moderate quality of evidence). AUTHORS' CONCLUSIONS: Radiotherapy for patients with incurable non-small cell lung cancer can improve thoracic symptoms. Care should be taken with the dose to the spinal cord to reduce the risk of radiation myelopathy. The higher dose, more fractionated palliative radiotherapy regimens do not provide better or more durable palliation and their use to prolong survival is not supported by strong evidence. More research is needed into reducing the acute toxicity of large fraction regimens and into the role of radical compared to high dose palliative radiotherapy. In the future, large trials comparing different RT regimens may be difficult to set up because of the increasing use of systemic chemotherapy. Trials looking at how best to integrate these two modalities, particularly in good PS patients, need to be carried out.

Toxin-coupled MHC class I tetramers can specifically ablate autoreactive CD8+ T cells and delay diabetes in nonobese diabetic mice.

There is compelling evidence that self-reactive CD8(+) T cells are a major factor in development and progression of type 1 diabetes in animals and humans. Hence, great effort has been expended to define the specificity of autoimmune CD8(+) T cells and to alter their responses. Much work has focused on tolerization of T cells using proteins or peptides. A weakness in this approach is that residual autoreactive T cells may be activated and exacerbate disease. In this report, we use a novel approach, toxin-coupled MHC class I tetramers. Used for some time to identify Ag-specific cells, in this study, we use that same property to delete the Ag-specific cells. We show that saporin-coupled tetramers can delete islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)-reactive T cells in vitro and in vivo. Sequence analysis of TCRbeta-chains of IGRP(+) cells reveals the repertoire complexity in the islets is markedly decreased as NOD mice age and significantly altered in toxic tetramer-treated NOD mice. Further tetramer(+) T cells in the islets are almost completely deleted, and, surprisingly, loss of tetramer(+) T cells in the islets is long lasting. Finally, we show deletion at 8 wk of age of IGRP(+) CD8(+) T cells, but not dystophia myotonica kinase- or insulin B-reactive cells, significantly delays diabetes in NOD mice.

Charles E. Rosenberg and the multifaceted promise of medical history.

Charles E. Rosenberg has had a major influence in defining the history of medicine as a field. However, critics who focus on his leadership or "school" in terms of defined scholarly perspectives, including those of social history and the framing of disease, offer inadequate descriptions of the messages, breadth, and scope of his scholarly work as a whole. Shoehorning the history of medicine into prescribed patterns in order to build a more unitary discipline would weaken rather than strengthen the field and is not in the Rosenberg tradition.

Identical beta cell-specific CD8(+) T cell clonotypes typically reside in both peripheral blood lymphocyte and pancreatic islets.

A major issue regarding T cell responses in autoimmunity is how the repertoire compares between the periphery and target organ. In type 1 diabetes, the status of at-risk or diabetic individuals can be monitored by measuring beta cell-specific T cells isolated from PBL, but whether these T cells accurately reflect the repertoire residing in the pancreatic islets is unclear. The TCR repertoire of disease-relevant, tetramer-sorted CD8(+) T cells was examined at the single-cell level in PBL, pancreatic lymph nodes (PLN), and the islets of individual NOD mice. CDR3alpha and CDR3beta sequences demonstrated that the same repertoire of T cells in PBL was detected in the islets and PLN, although the frequency of specific clonotypes varied. Albeit infrequent, clonotypes that were prevalent in the islets but not found in PBL were also detected. beta cell Ag immunization expanded immunodominant PBL clonotypes present in the islets and PLN. These results show that insight into repertoire profiles of islet-infiltrating T cells can be obtained from PBL.

Feline cytokine ELISPOT: issues in assay development.

The enzyme-linked immunospot (ELISPOT) assay is a sensitive and relatively simple assay for detecting secreted cellular products such as cytokines and has become an invaluable immunological tool. The ELISPOT has been used extensively in human and murine research but has only recently been used to assess the feline immune system. For researchers studying feline disease or using the cat as a model of human disease, the quantification of cytokine-producing cells by ELISPOT is an invaluable technique for investigations of disease immunopathogenesis and vaccine efficacy. For example, use of the interferon (IFN)-gamma ELISPOT to measure the frequency of antigen-specific T-cells during feline immunodeficiency virus (FIV) infection or after immunization with candidate FIV vaccines is of particular interest. This application of the ELISPOT may serve to expand the utility of FIV as a model for human immunodeficiency virus. Broader applications of the ELISPOT should further our understanding of feline diseases and be useful in the rational development of more efficacious vaccines and therapeutic modalities for the enhancement of feline health. This chapter discusses important parameters of ELISPOT design that will enable researchers to develop and analyze the feline-specific assays within their own laboratory.

Pre-existing immunity to pathogenic Listeria monocytogenes does not prevent induction of immune responses to feline immunodeficiency virus by a novel recombinant Listeria monocytogenes vaccine.

Listeria monocytogenes is an attractive biologic vaccine vector against HIV because it induces a strong cell mediated immune response, can be delivered by mucosal routes, can be readily manipulated to express viral antigens, and is easy and inexpensive to produce. Proof of concept studies have been performed using HIV Gag expressing recombinant L. monocytogenes in the mouse. Here we report the development and validation of recombinant L. monocytogenes to be evaluated in the FIV/cat model of HIV. Using a simplified approach to introduce individual and polyprotein FIV gag genes, we show that recombinant L. monocytogenes containing the entire gag expresses the full-length Gag polyprotein in a soluble secreted form. A DNA vaccine plasmid (pND14-Lc-env) that replicates in Gram positive bacteria and contains the FIV SU (gp100) and the ectodomain of TM (gp40) in a eukaryotic expression cassette was transfected into LM-gag to create LM-gag/pND14-Lc-env. After infection of target cells with LM-gag/pND14-Lc-env in vitro, both FIV Gag and Env proteins were detected in soluble cell lysates. Whether previous exposure to L. monocytogenes affects the immunogenicity of LM-gag/pND14-Lc-env was determined in cats infected with wild-type L. monocytogenes orally and/or subcutaneously. After a single oral dose of LM-gag/pND14-Lc-env, cats with existing anti-L. monocytogenes immune responses developed anti-FIV Gag IgA titers in vaginal secretions, saliva, and feces. Similarly, FIV Gag and Env specific IFN-gamma ELISPOT responses were measurable in spleen and lymph node but at a statistically higher frequency in cats exposed to a single subcutaneous dose of wild-type L. monocytogenes versus cats exposed both subcutaneously and orally. The FIV/cat model will provide a useful challenge system to determine whether recombinant L. monocytogenes can protect against a lentivirus in its natural host after challenge by the routes common to HIV transmission.

Oral immunization with recombinant listeria monocytogenes controls virus load after vaginal challenge with feline immunodeficiency virus.

Recombinant Listeria monocytogenes has many attractive characteristics as a vaccine vector against human immunodeficiency virus (HIV). Wild-type and attenuated Listeria strains expressing HIV Gag have been shown to induce long-lived mucosal and systemic T-cell responses in mice. Using the feline immunodeficiency virus (FIV) model of HIV we evaluated recombinant L. monocytogenes in a challenge system. Five cats were immunized with recombinant L. monocytogenes that expresses the FIV Gag and delivers an FIV Env-expressing DNA vaccine (LMgag/pND14-Lc-env). Control cats were either sham immunized or immunized with wild-type L. monocytogenes (LM-wt). At 1 year after vaginal challenge, provirus could not be detected in any of the nine tissues evaluated from cats immunized with the recombinant bacteria but was detected in at least one tissue in 8 of 10 control animals. Virus was isolated from bone marrow of four of five LMgag/pND14-Lc-env-immunized cats by use of a stringent coculture system but required CD8(+) T-cell depletion, indicating CD8(+) T-cell suppression of virus replication. Control animals had an inverted CD4:CD8 ratio in mesenteric lymph node and were depleted of both CD4(+) and CD8(+) intestinal epithelial T cells, while LMgag/pND14-Lc-env-immunized animals showed no such abnormalities. Vaginal FIV-specific immunoglobulin A was present at high titer in three LMgag/pND14-Lc-env-immunized cats before challenge and in all five at 1 year postchallenge. This study demonstrates that recombinant L. monocytogenes conferred some control of viral load after vaginal challenge with FIV.

Themes in the history of medical professionalism.

Professionalism in medicine is an ambiguous term. Discussions are hampered by understandings of the past that are counterproductive to today s debates. Three decades of criticism of physicians as self-interested and arrogant, and of professional organizations as unfairly monopolistic have shaken the confidence of professional leaders and their constituents in their ability to act as a positive social force, and left the concept of professional autonomy without a useful meaning. Inherited assumptions about conflict between the profession, government and the market have encouraged organizational policies to fight familiar enemies for short-term gains, rather than reinvent professionalism as a social force or seek new strategic alliances. This article stresses the importance of distancing the present from the past in re-inventing professionalism for the future, and lists eight fundamental goals.