Novel strategies for targeting innate immune responses to influenza.

We previously reported that TLR4(-/-) mice are refractory to mouse-adapted A/PR/8/34 (PR8) influenza-induced lethality and that therapeutic administration of the TLR4 antagonist Eritoran blocked PR8-induced lethality and acute lung injury (ALI) when given starting 2 days post infection. Herein we extend these findings: anti-TLR4- or -TLR2-specific IgG therapy also conferred significant protection of wild-type (WT) mice from lethal PR8 infection. If treatment is initiated 3 h before PR8 infection and continued daily for 4 days, Eritoran failed to protect WT and TLR4(-/-) mice, implying that Eritoran must block a virus-induced, non-TLR4 signal that is required for protection. Mechanistically, we determined that (i) Eritoran blocks high-mobility group B1 (HMGB1)-mediated, TLR4-dependent signaling in vitro and circulating HMGB1 in vivo, and an HMGB1 inhibitor protects against PR8; (ii) Eritoran inhibits pulmonary lung edema associated with ALI; (iii) interleukin (IL)-1ß contributes significantly to PR8-induced lethality, as evidenced by partial protection by IL-1 receptor antagonist (IL-1Ra) therapy. Synergistic protection against PR8-induced lethality was achieved when Eritoran and the antiviral drug oseltamivir were administered starting 4 days post infection. Eritoran treatment does not prevent development of an adaptive immune response to subsequent PR8 challenge. Overall, our data support the potential of a host-targeted therapeutic approach to influenza infection.

Neuroimmune semaphorin 4A as a drug and drug target for asthma.

Neuroimmune semaphorin 4A (Sema4A) has been shown to play an important costimulatory role in T cell activation and regulation of Th1-mediated diseases such as multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE), and experimental autoimmune myocarditis (EAM). Sema4A has three functional receptors, Tim-2 expressed on CD4+ T cells, Th2 cells in particular, and Plexin B1 and D1 predominantly expressed on epithelial and endothelial cells, correspondingly. We recently showed that Sema4A has a complex expression pattern in lung tissue in a mouse model of asthma. We and others have shown that corresponding Plexin expression can be found on immune cells as well. Moreover, we demonstrated that Sema4A-deficient mice displayed significantly higher lung local and systemic allergic responses pointing to its critical regulatory role in the disease. To determine the utility of Sema4A as a novel immunotherapeutic, we introduced recombinant Sema4A protein to the allergen-sensitized WT and Sema4A(-/-) mice before allergen challenge. We observed significant reductions in the allergic inflammatory lung response in Sema4A-treated mice as judged by tissue inflammation including eosinophilia and mucus production. Furthermore, we demonstrated that in vivo administration of anti-Tim2 Ab led to a substantial upregulation of allergic inflammation in WT mouse lungs. These data highlight the potential to develop Sema4A as a new therapeutic for allergic airway disease.

Neuroimmune semaphorin 4D is necessary for optimal lung allergic inflammation.

Neuroimmune semaphorin 4D (Sema4D) was found to be expressed and function in the nervous and immune systems. In the immune system, Sema4D is constitutively expressed on T cells and regulates T cell priming. In addition, it displays a stimulatory function on macrophages, DC, NK cells, and neutrophils. As all these cells are deeply involved in asthma pathology, we hypothesized that Sema4D plays a critical non-redundant regulatory role in allergic airway response. To test our hypothesis, we exposed Sema4D(-/-) and WT mice to OVA injections and challenges in the well-defined mouse model of OVA-induced experimental asthma. We observed a significant decrease in eosinophilic airway infiltration in allergen-treated Sema4D(-/-) mice relative to WT mice. This reduced allergic inflammatory response was associated with decreased BAL IL-5, IL-13, TGFß1, IL-6, and IL-17A levels. In addition, T cell proliferation in OVA323₋339-restimulated Sema4D(-/-) cell cultures was downregulated. We also found increased Treg numbers in spleens of Sema4D(-/-) mice. However, airway hyperreactivity (AHR) to methacholine challenges was not affected by Sema4D deficiency in either acute or chronic experimental disease setting. Surprisingly, lung DC number and activation were not affected by Sema4D deficiency. These data provide a new insight into Sema4D biology and define Sema4D as an important regulator of Th2-driven lung pathophysiology and as a potential target for a combinatory disease immunotherapy.

Neuroimmune semaphorin 4A downregulates the severity of allergic response.

To define the role of semaphorin 4A (Sema4A) in allergic response, we employed Sema4A⁻/⁻ and wild-type (WT) mice in the experimental model of ovalbumin (OVA)-induced allergic airway inflammation. We observed a selective increase in eosinophilic airway infiltration accompanied by bronchial epithelial cell hyperplasia in allergen-treated Sema4A⁻/⁻ mice relative to WT mice. This enhanced inflammatory response was associated with a selective increase in bronchoalveolar lavage (BAL) interleukin 13 (IL-13) content, augmented airway hyperreactivity, and lower regulatory T cell (Treg) numbers. In vivo allergen-primed Sema4A⁻/⁻ CD4+ T cells were more effective in transferring T helper type 2 (Th2) response to naive mice as compared with WT CD4+ T cells. T-cell proliferation and IL-13 productions in OVA323₋339-restimulated Sema4A⁻/⁻ cell cultures were upregulated. Generated bone marrow chimeras showed an equal importance of both lung-resident cell and inflammatory cell Sema4A expression in optimal disease regulation. These data provide a new insight into Sema4A biology and define Sema4A as an important regulator of Th2-driven lung pathophysiology.

Medical students' assessments of skill development in rural primary care clinics.

INTRODUCTION: This study assessed the impact of a rural primary care preceptorship on medical students' self-perceived ability to provide acute, chronic, and preventive care, to perform procedures, to communicate with patients, and to understand the community and healthcare system. METHODS: Students were surveyed about their self-assessed skills on 11 major components (97 items) immediately before and after a 16 week preceptorship in a rural primary care clinic. Responses were analyzed for 96 medical students using a paired comparisons t-test and univariate statistics. RESULTS: Students' skills significantly increased on all components and items. The skills most highly assessed post-preceptorship were those skills related to the management of chronic problems, the provision of patient education and health maintenance, and the ability to handle undifferentiated and acute problems. Among the 11 components assessed, students ranked their skills in performing procedures the lowest. The largest cumulative gain in skills was in the areas of understanding health systems and the community. CONCLUSIONS: This study provides a unique opportunity to look at skill development before and after a rural clerkship. From the student's perspective, the 16 week preceptorship appears to be of significant educational benefit. Future studies need to examine other measures of performance and outcomes of training in rural primary care settings.

From idea to market: the drug approval process.

BACKGROUND: Each year many new prescription drugs are approved by the Food and Drug Administration (FDA). The process of developing and bringing new drugs to market is important for primary care physicians to understand. METHODS: We describe the drug development process based on a review of the literature and Web sites addressing FDA processes and policies. RESULTS: The process starts with preclinical testing. For drugs that appear safe, an investigational new drug application is filed with the FDA. If approved, clinical trials begin with phase 1 studies that focus on safety and pharmacology. Phase 2 studies examine the effectiveness of the compound. Phase 3 is the final step before submitting a new drug application (NDA) to the FDA. An NDA contains all the information obtained during all phases of testing. Phase 4 studies, or postmarketing studies, are conducted after a product is approved. Recent changes in legislation have streamlined the approval process. Critics contend that these changes have compromised public safety, resulting in the need to recall several products from the market. Proponents claim that changes in the approval process help patients with debilitating diseases, such as acquired immunodeficiency syndrome, that were previously denied critical medication because of bureaucratic regulations.

Accuracy of CPT evaluation and management coding by family physicians.

BACKGROUND: Limited data are available on physicians' accuracy in coding for their services. The purpose of this study was to determine the current procedural terminology (CPT) evaluation and management coding accuracy of family physicians and define demographic variables associated with coding accuracy. METHODS: Six hundred randomly selected active members of the Illinois Academy of Family Physicians were sent six hypothetical progress notes of office visits along with a demographic survey. The study group assigned CPT evaluation and management codes to each of the progress notes and completed the demographic survey. Five expert coders also assigned codes to each of the cases. The accuracy of family physicians in determining CPT E/M codes was determined relative to that of expert coders. RESULTS: Family physicians agreed with the experts' CPT evaluation and management codes for 52% of established patient progress notes, the most common error being undercoding. In contrast, for new patient progress notes, family physicians agreed with the experts only 17% of the time, the predominant error being overcoding. No surveyed demographic variable was associated with coding accuracy. CONCLUSIONS: The error rate for physician CPT coding is substantial and occurs more commonly with new patients. The complexity of the CPT coding guidelines, along with limited physician training in CPT coding, likely account for these results.

A national survey of procedural skill requirements in family practice residency programs.

BACKGROUND AND OBJECTIVES: Procedural skill training is a controversial but important component of family practice residency programs. This study examines the use and composition of required procedure lists in US family practice residency programs. METHODS: The study used a cross-sectional nine-item questionnaire. This survey was sent to 467 residency program directors listed in the 1999 American Academy of Family Physicians Directory of Family Practice Residency Programs. RESULTS: A total of 326 programs (70%) responded to the survey. Of these, 242 programs (74% of respondents) reported use of a required procedure list. Sixty-six programs provided a list. Of these, 63 lists were interpretable. The number of required procedures on the lists ranged from a minimum of 3 procedures to a maximum of 117, with an average of 42. A total of 265 distinct procedures were identified, with 25 procedures named on more than half of the lists. Thirteen programs (21%) mandated competency in required procedures, but only five programs (8%) gave clear definitions of what constituted competency. There were no significant differences in lists among training program type, university affiliation, number of hospitals used for rotation, size of affiliated hospital, or number of residents. CONCLUSIONS: The expectations of individual programs vary greatly in terms of required procedures. Few programs define how to evaluate the technical competency of their residents.

Diagnosis of vaginitis.

Vaginitis is the most common gynecologic diagnosis in the primary care setting. In approximately 90 percent of affected women, this condition occurs secondary to bacterial vaginosis, vulvovaginal candidiasis or trichomoniasis. Vaginitis develops when the vaginal flora has been altered by introduction of a pathogen or by changes in the vaginal environment that allow pathogens to proliferate. The evaluation of vaginitis requires a directed history and physical examination, with focus on the site of involvement and the characteristics of the vaginal discharge. The laboratory evaluation includes microscopic examination of a saline wet-mount preparation and a potassium hydroxide preparation, a litmus test for the pH of vaginal secretions and a "whiff" test. Metronidazole is the primary treatment for bacterial vaginosis and trichomoniasis. Topical antifungal agents are the first-line treatments for candidal vaginitis.

Differential expression of two CYP1A genes in rainbow trout (Oncorhynchys mykiss).

Differential expression of two rainbow trout CYP1A genes was measured in vivo and in vitro in response to treatment with the model CYP1A inducers beta-naphthoflavone (BNF), 3-methylcholanthrene (3-MC), isosafrole (ISF), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, only in vitro). Originally described by Berndtson and Chen (Arch. Biochem. Biophys. 310, 187-195, 1994) as CYP1A1 and CYP1A2, these genes were renamed CYP1A3 and CYP1A1, respectively, by the P450 nomenclature committee. A significant, differential, inducer-dependent induction of the two CYP1A mRNAs, as measured by RNase protection assay, was observed in vivo. CYP1A3 and CYP1A1 mRNA levels in liver were significantly induced 50- and 18-fold, respectively, following ip injection with BNF. Conversely, CYP1A3 and CYP1A1 mRNA levels were significantly induced 5- and 66-fold, respectively, following ip injection with 3-MC. Isosafrole had no significant effect on in vivo induction of CYP1A mRNA levels. In primary cultures of hepatocytes, BNF, 3-MC, ISF, as well as TCDD all significantly induced CYP1A3 and CYP1A1 mRNA levels compared to controls. The differential induction of the two CYP1A genes was not as evident in vitro as in vivo. In addition, reanalysis and sequence comparison of the these two trout CYP1A genes with the first trout CYP1A cDNA described by Heilmann et al. (DNA 7, 379-387, 1988) indicate that the Heilmann cDNA is a hybrid of the two trout genes. The 5' portion of the cDNA sequence (212 bp) was determined by sequencing of a genomic clone and is 100% identical to the trout CYP1A3 gene. The majority of the cDNA sequence (2377 bp), however, was sequenced from a partial cDNA clone and is 99.2% identical to trout CYP1A1. Although the nomenclature of these two trout CYP1A genes is undergoing revision, these results demonstrate a differential, inducer-dependent response to model mammalian CYP1A inducers.

Impact of vaginal antifungal products on utilization of health care services: evidence from physician visits.

BACKGROUND: Recently many medications formerly available only by prescription have been approved for over-the-counter (OTC) status. In 1990, clotrimazole became the first available OTC drug to treat candidal vaginitis. Subsequently several other prescription antifungal medications have also been available in OTC products. One proposed benefit of these switches from prescription to OTC status is a reduction in the utilization of health care services. METHODS: Using National Ambulatory Medical Care Survey data, the average numbers of annual visits for vaginal complaints were estimated for 1985, 1990, and 1994. These years were chosen because they represented periods before, close to, and after the approval of the OTC antifungal preparations. The estimated visits for each year were compared using a chi-square analysis with a sample weight correction. RESULTS: There was a 15% decline in the number of vaginitis visits from 1990 to 1994 that potentially could be attributed to the availability of the OTC antifungal preparations. The decrease in physician visits results in approximately $45 million in direct cost savings and another $18.75 million in indirect savings by reducing time lost from work. CONCLUSIONS: It appears that the availability of OTC anticandidal fungal preparations reduces the number of physician visits for vaginitis, resulting in cost savings.

Evaluation of nursing home patients. A systematic approach can improve care.

As the US population ages, the proportion of patients receiving long-term care is increasing. To meet the challenge of providing quality care for these patients, physicians need to be prepared to efficiently evaluate their needs and formulate individualized care plans. In this article, Drs King and Lipsky discuss the unique aspects of caring for nursing home patients, including the role of patients' families in the overall plan. They present a practical, structured approach to evaluation and follow-up care, which they have encapsulated into two handy assessment forms.

The short-term impact of a continuing medical education program on providers' attitudes toward treating diabetes.

OBJECTIVE: The objective of this study was to evaluate the short-term impact of a 7-h type 2 diabetes continuing medical education (CME) program. Outcomes included a measure of health care providers' diabetes knowledge and the Diabetes Attitude Scale (DAS), a validated measure of attitudes toward diabetes. RESEARCH DESIGN AND METHODS: A CME program on type 2 diabetes was presented by an expert panel in Chicago during November 1998. A before-after trial with pre- and postintervention measurements of diabetes knowledge and attitudes toward diabetes was administered as part of the program. A convenience sample of the 129 health care providers in attendance resulted in 91 (71%) completed pre- and postintervention surveys. RESULTS: Within-subjects analysis revealed increases in knowledge and more favorable attitudes toward diabetes after the program. Between-subjects analysis revealed that attitude changes differed for physicians as compared with allied health care providers. CONCLUSIONS: A CME program was associated with an increase in knowledge of diabetes and more favorable attitudes toward diabetes as measured by the DAS. The DAS changes were subtly different for the physician group as compared with the allied health care provider group. These results suggest that the DAS can be a useful instrument for measuring the short-term impact of educational interventions.

Using compensation to improve primary care.

Progressive primary care networks are now placing significant portions of physician salaries at risk by linking compensation to quantifiable measures such as net medical revenue (collections), reduced practice expenses, cost and utilization, quality of care and patient satisfaction. For most networks, a combination of productivity increases and expense reductions are critical to ensure financial survival. This case study illustrates how one network's unique incentive compensation program targeted higher productivity levels by incentivizing desirable behaviors.

Students' evaluations of teaching and learning experiences at community- and residency-based practices.

BACKGROUND: Research has identified students' preferences for clinical sites and the clinical teaching behaviors of preceptors valued by students. This study investigated medical students' perceptions of preceptor teaching behaviors and student performance information at community- and residency-based sites. METHODS: The sample was 594 third-year medical students who completed a 4-week rotation in family medicine at community- and residency-based sites. Students completed two evaluation instruments that addressed clinical experiences and perceptions of effective teaching by clinical preceptors. RESULTS: For the majority of items, no statistically significant differences were found between students' rating of preceptors at private practices and residency sites. Generally, the students rated both types of preceptors as favorable. Student clinical performance was rated higher at community sites. CONCLUSIONS: Overall, preceptor teaching behaviors at community practices and residency programs were rated favorably by students. Differences were noted between site types in their clinical evaluation of students.

The "prescription-to-OTC switch" movement. Its effects on antifungal vaginitis preparations.

More than 600 over-the-counter (OTC) products have ingredients or dosages that were previously available by prescription only. The criteria for switching drugs include a low potential for misuse or abuse, safety and efficacy, and the ability for effective use by the average person. In addition, the conditions the drugs treat should be benign and self-limited. In 1990, the first topical imidazole for candidal vaginitis was approved by the Food and Drug Administration for over-the-counter use. Suggested benefits of this switch were increased patient autonomy and reduced costs. Risks include potential for misdiagnoses, resulting in inappropriate use, unnecessary use, or delay in treatment, which could lead to increased cost and morbidity. Despite the wide use of these products, there is little evidence examining the outcome of the switch. Limited available data suggest that the switch of the antifungal preparations reduces costs with little objective evidence of harm resulting from the switch.

Febrile-range temperature modifies early systemic tumor necrosis factor alpha expression in mice challenged with bacterial endotoxin.

Fever improves survival in acute infections, but the effects of increased core temperature on host defenses are poorly understood. Tumor necrosis factor alpha (TNF-alpha) is an early activator of host defenses and a major endogenous pyrogen. TNF-alpha expression is essential for survival in bacterial infections but, if disregulated, can cause tissue injury. In this study, we show that passively increasing core temperature in mice from the basal (36.5 to 37.5 degrees C) to the febrile (39.5 to 40 degrees C) range modifies systemic TNF-alpha expression in response to bacterial endotoxin (lipopolysaccharide). The early TNF-alpha secretion rate is enhanced, but the duration of maximal TNF-alpha production is shortened. We identified Kupffer cells as the predominant source of the excess TNF-alpha production in the warmer animals. The enhanced early TNF-alpha production observed at the higher temperature in vivo could not be demonstrated in isolated Kupffer cells or in precision-cut liver slices in vitro, indicating the participation of indirect pathways. Therefore, expression of the endogenous pyrogen TNF-alpha is regulated by increments in core temperature during fever, generating an enhanced early, self-limited TNF-alpha pulse.