A novel TLR2 agonist from Bordetella pertussis is a potent adjuvant that promotes protective immunity with an acellular pertussis vaccine

Bordetella pertussis causes whooping cough, a severe and often lethal respiratory infection in infants. A recent resurgence of pertussis has been linked with waning or suboptimal immunity induced with acellular pertussis vaccines (Pa) that were introduced to most developed countries in the 1990s because of safety concerns around the use of whole-cell pertussis vaccines (Pw). Pa are composed of individual B. pertussis antigens absorbed to alum and promote strong antibody, T helper type 2 (Th2) and Th17 responses, but are less effective at inducing cellular immunity mediated by Th1 cells. In contrast, Pw, which include endogenous Toll-like receptor (TLR) agonists, induce Th1 as well as Th17 responses. Here we report the identification and characterization of novel TLR2-activating lipoproteins from B. pertussis. These proteins contain a characteristic N-terminal signal peptide that is unique to Gram-negative bacteria and we demonstrate that one of these lipoproteins, BP1569, activates murine dendritic cells and macrophages and human mononuclear cells via TLR2. Furthermore, we demonstrated that a corresponding synthetic lipopeptide LP1569 has potent immunostimulatory and adjuvant properties, capable of enhancing Th1, Th17, and IgG2a antibody responses induced in mice with an experimental Pa that conferred superior protection against B. pertussis infection than an equivalent vaccine formulated with alum.

Immunity to the respiratory pathogen Bordetella pertussis

Bordetella pertussis causes whooping cough, a severe respiratory tract infection in infants and children, and also infects adults. Studies in murine models have shown that innate immune mechanisms involving dendritic cells, macrophages, neutrophils, natural killer cells, and antimicrobial peptides help to control the infection, while complete bacterial clearance requires cellular immunity mediated by T-helper type 1 (Th1) and Th17 cells. Whole cell pertussis vaccines (wP) are effective, but reactogenic, and have been replaced in most developed countries by acellular pertussis vaccines (aP). However, the incidence of pertussis is still high in many vaccinated populations; this may reflect sub-optimal, waning, or escape from immunity induced by current aP. Protective immunity generated by wP appears to be mediated largely by Th1 cells, whereas less efficacious alum-adjuvanted aP induce strong antibody Th2 and Th17 responses. New generation aP that induce Th1 rather than Th2 responses are required to improve vaccine efficacy and prevent further spread of B. pertussis.

GPs' views of discussions of prognosis in severe COPD

BACKGROUND

Modern palliative care promotes open communication between doctor and patient, which includes access to information about prognosis. GPs play a major role in managing chronic obstructive pulmonary disease (COPD) patients in the final stages of illness. Their views of discussions of prognosis are therefore important if the principles of palliative care are to be extended to COPD.

OBJECTIVE

Our aim was to investigate the role that discussions of prognosis play in GPs' management of patients with severe COPD and the factors that influence those discussions.

METHODS

We conducted a questionnaire survey of all GP principals of one inner London Health Authority (n = 389) in April 1999. Questionnaire development involved a literature review to identify issues of importance to GPs in the discussion of prognosis in COPD, and in-depth interviews with five GPs.

RESULTS

Of the 214 respondents (55% response), 72.5% thought that discussions of prognosis were often necessary or essential in severe COPD. The majority (82%) felt that GPs have an important role in these discussions. However, only a minority (41%) of GPs reported often or always discussing prognosis. Half the GPs were undecided as to whether most patients with COPD wanted to know about their prognosis. Among the GPs who reported rarely or never discussing prognosis (n = 33), a majority felt ill-prepared to discuss the subject (60% reported that there was insufficient information in the primary care notes to be able to discuss prognosis, and 64% found it hard to start discussions with patients).

CONCLUSION

Although the majority of GPs acknowledged a need to discuss prognosis in severe COPD, this was not reflected in their reported behaviour. It appears that the palliative care approach of open communication, whilst seen to be relevant to severe COPD, is not applied routinely in managing the disease in primary care. Uncertainty among GPs as to how patients view the discussion of prognosis and inadequate preparation may pose potential barriers.

Teaching professional development in medical schools

Doctors must increasingly be aware of what they should be, as well as what they should know. Professionalism, including a value system that supports the compassionate care of patients, is a means of encapsulating and prioritising these competing responsibilities. Accordingly, in this article, we assume that professionalism is an essential aspect of medical practice that needs to be taught to those entering medicine. We first describe critiques of professionalism and current challenges to it, in practice and in medical education. We then assess the current efforts of curriculum reform to incorporate professionalism and the methods used to teach it. Adopting and assessing such approaches to ensure that they are effective is of central importance in the education of future clinicians.

Changing face of medical curricula

The changing role of medicine in society and the growing expectations patients have of their doctors means that the content and delivery of medical curricula also have to change. The focus of health care has shifted from episodic care of individuals in hospitals to promotion of health in the community, and from paternalism and anecdotal care to negotiated management based on evidence of effectiveness and safety. Medical training is becoming more student centred, with an emphasis on active learning rather than on the passive acquisition of knowledge, and on the assessment of clinical competence rather than on the ability to retain and recall unrelated facts. Rigid educational programmes are giving way to more adaptable and flexible ones, in which student feedback and patient participation have increasingly important roles. The implementation of sustained innovation in medical education continues to present challenges, especially in terms of providing institutional and individual incentives. However, a continuously evolving, high quality medical education system is needed to assure the continued delivery of high quality medicine.

Frontiers in care: a case of compulsory treatment in AIDS dementia. Case study and commentaries

A patient with AIDS dementia was confronted and compulsorily prevented from flying out of the country before being admitted against his will to hospital. While finding this on balance justified in the circumstances the commentators raise moral questions about the levels of care in general practice and within the couple's own relationships.

Do studies of the nature of cases mislead about the reality of cases? A response to Pattison et al

This article questions whether many are misled by current case studies. Three broad types of style of case study are described. A stark style, based on medical case studies, a fictionalised style in reaction, and a personal statement made in discussion groups by an original protagonist. Only the second type fits Pattison's category. Language remains an important issue, but to be examined as the case is lived in discussion rather than as a potentially reductionist study of the case as text.

Advantages of raloxifene over alendronate or estrogen on nonreproductive and reproductive tissues in the long-term dosing of ovariectomized rats

For the first time, raloxifene or alendronate was administered to rats immediately after ovariectomy for 10 months and compared with estrogen to elucidate mechanisms behind the raloxifene effects observed in nonreproductive and reproductive tissues. Specifically, 75-day-old rats were randomly selected as sham controls (Sham), ovariectomized controls (Ovx) or ovariectomized rats treated with fully efficacious doses of raloxifene (RA), 17 alpha-ethynyl estradiol (EE2) or alendronate (ABP). Lumbar vertebrae and proximal tibiae were examined by computed tomography (QCT) and by histomorphometry. Histomorphometry showed differences in bone architecture between groups when QCT densities were similar, but tibial trabecular bone analysis by QCT correlated with histomorphometry with r = .86 to .93, depending on the parameter. Both techniques confirmed that Ovx had substantially less bone than Sham, with greater loss of trabecular bone in the proximal tibia than vertebrae. Both techniques showed that RA had effects similar to but not identical with EE2 in preventing bone loss in vertebrae and tibiae. ABP partially prevented loss of bone in L-5, but was not significantly different from Ovx in the proximal tibia. This may be caused by ABP suppression of bone apposition, beyond effects observed for EE2 or RA. RA appeared to be more similar to EE2 because ABP significantly depressed bone formation (bone formation rate, mineral apposition rate) to below RA or EE2 levels, especially in L-5. Mechanical loading to failure of L-6 vertebrae showed a rank order of vertebral strength of Sham > RA > EE2 > Ovx > ABP, although significant differences were not observed between treatment groups. These data show that ABP suppression of bone formation can affect bone quality with long-term treatment. In other tissues, RA had minimal uterine effects, while significantly lowering serum cholesterol to below EE2-treated levels. Both EE2 and RA rats had significantly lower body weights than the other groups. ABP had no effect on serum lipids, uterine weight or body weight. Therefore, RA appears to have a broader range of desirable effects on bone, body weight, uteri and cholesterol than ABP or EE2 in ovariectomized rats.

Primary care in the accident and emergency department: II. Comparison of general practitioners and hospital doctors

OBJECTIVE

To compare the process and outcome of "primary care" consultations undertaken by senior house officers, registrars, and general practitioners in an accident and emergency department.

DESIGN

Prospective, controlled intervention study.

SETTING

A busy, inner city accident and emergency department in south London.

SUBJECTS

Patients treated during a stratified random sample of 419 three hour sessions between June 1989 and May 1990 assessed at nurse triage as presenting with problems that could be treated in a primary care setting. 1702 of these patients were treated by sessionally employed local general practitioners, 2382 by senior house officers, and 557 by registrars.

MAIN OUTCOME MEASURES

Process variables: laboratory and radiographic investigations, prescriptions, and referrals; outcome variables: results of investigations.

RESULTS

Primary care consultations made by accident and emergency medical staff resulted in greater utilisation of investigative, outpatient, and specialist services than those made by general practitioners. For example, the odds ratios for patients receiving radiography were 2.78 (95% confidence interval 2.32 to 3.34) for senior house officer v general practitioner consultations and 2.37 (1.84 to 3.06) for registrars v general practitioners. For referral to hospital specialist on call teams or outpatient departments v discharge to the community the odds ratios were 2.88 (2.39 to 3.47) for senior house officers v general practitioners and 2.57 (1.98 to 3.35) for registrars v general practitioners.

CONCLUSION

Employing general practitioners in accident and emergency departments to manage patients with primary care needs seems to result in reduced rates of investigations, prescriptions, and referrals. This suggests important benefits in terms of resource utilisation, but the impact on patient outcome and satisfaction needs to be considered further.

Further studies on N-methyl-1(3,4-methylenedioxyphenyl)-2-aminopropane as a discriminative stimulus: antagonism by 5-hydroxytryptamine3 antagonists

Using a standard two-lever operant paradigm, male Sprague-Dawley rats were trained to discriminate 1.5 mg/kg N-methyl-1(3,4-methylenedioxyphenyl)-2- aminopropane (MDMA) from saline using a variable-interval 15-s schedule of reinforcement for food reward. Tests of stimulus antagonism were conducted to further define the mechanism of action of MDMA as a discriminative stimulus. Low doses of the 5-hydroxytryptamine1A (5-HT1A) antagonist NAN-190, the 5-HT2 antagonist pirenperone, and the dopamine antagonist haloperidol were able to somewhat attenuate the MDMA stimulus; however, none of these agents decreased MDMA-appropriate responding to less than 46%. The 5-HT3 antagonists zacopride and LY 278584 (ID50 = 0.02 micrograms/kg) antagonized the MDMA discriminative stimulus. Zacopride also attenuated the stimulus effects of 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM) in DOM-trained animals but not those of (+)amphetamine in (+)amphetamine-trained animals. Several possible mechanistic interpretations are provided but it is concluded that MDMA produces its stimulus effects via a complex mechanism involving both dopaminergic and serotonergic components.

Investigation of MDMA-related agents in rats trained to discriminate MDMA from saline

To determine whether metabolite-related analogs of N-methyl-1-(3,4-methylenedioxyphenyl)-2-aminopropane (MDMA) produce stimulus effects similar to those of the parent compound, and to determine the structural requirements associated with the MDMA stimulus, several MDMA analogs were examined in tests of stimulus generalization using rats trained to discriminate 1.5 mg/kg MDMA from saline. Although several of the analogs produced up to 50-60% MDMA-appropriate responding, none [with the exception of N-methyl-1-(4-methoxyphenyl)-2-aminopropane (PMMA)] resulted in stimulus generalization. The partial generalization, coupled with the possible reduced ability of certain of the agents to penetrate the blood-brain barrier relative to MDMA, suggests that these agents are not behaviorally inactive. PMMA, although not a metabolite of MDMA, is closely related in chemical structure to MDMA and its metabolites; PMMA produces > 80% MDMA-appropriate responding and is approximately three times more potent (ED50 = 0.2 mg/kg) than MDMA itself (ED50 = 0.76 mg/kg). PMMA is a newer scheduled substance with an as yet unknown mechanism of action; however, on the basis of the stimulus generalization observed PMMA may share some behavioral and mechanistic similarity with MDMA. These results also indicate that an intact methylenedioxy ring, such as that found in MDMA but absent in PMMA, is not a prerequisite for MDMA-like activity and further support the notion that ring-opened MDMA metabolites may produce effects that contribute to the actions of MDMA.

Managing the difficult patient: practical suggestions from a study day

A study day for general practitioners was arranged on the subject of managing the difficult patient. Participants were asked to supply written details of their most difficult patient and the problems they associated with him or her. The issues raised were addressed in a number of formal presentations and formed the basis for discussion in workshops. This paper focuses on the underlying similarities between the patients and discusses a practical approach to their management.

Identity cards for patients infected with HIV?

Dr A C Srivastava has written to us to describe a case that raises the suggestion that people infected with the human immuno-deficiency virus (HIV) should carry identity cards. We asked two physicians, a general practitioner working with patients with the acquired immune deficiency syndrome (AIDS), and a general practitioner with a special interest in medical ethics to respond to the broad issues raised by Dr Srivastava's letter.

Example of intermediate care: the new Lambeth Community Care Centre

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Making up her mind: consent, pregnancy and mental handicap

The following case was presented by a trainee general practitioner, working in inner London, to her release course for discussion. It is told, as it was presented, in the immediate aftermath of the events described. The names and some of the details have been altered.

Truth at the last--a case of obstructed death?

The following case breaks with tradition by having only one commentary upon it, and that is from the doctor who submitted the case. We invite readers to make their own analysis of his comments, and to respond as appropriate.

Gastroenteritis in London and Jamaica: a clinical and bacteriological study

The flora of both faeces and small bowel lumen was studied in children with gastroenteritis from London, England, and Kingston, Jamaica. Clinical and laboratory differences between these two groups are described. All bacterial groups in the faeces were greatly altered during gastroenteritis and this particularly affected anaerobic organisms. These changes generally reverted rapidly to normal after the illness. The small bowel flora was also altered during gastroenteritis; there was a tendency for a wider range of organisms including anaerobes to be isolated from the children in Jamacia than from those in England.