Mathematical analysis of antigen selection in somatically mutated immunoglobulin genes associated with autoimmunity

Affinity maturation is a process by which low-affinity antibodies are transformed into highly specific antibodies in germinal centres. This process occurs by hypermutation of immunoglobulin heavy chain variable (IgH V) region genes followed by selection for high-affinity variants. It has been proposed that statistical tests can identify affinity maturation and antigen selection by analysing the frequency of replacement and silent mutations in the complementarity determining regions (CDRs) that contact antigen and the framework regions (FRs) that encode structural integrity. In this study three different methods that have been proposed for detecting selection: the binomial test, the multinomial test and the focused binomial test, have been assessed for their reliability and ability to detect selection in human IgH V genes. We observe first that no statistical test is able to identify selection in the CDR antigen-binding sites, second that tests can reliably detect selection in the FR and third that antibodies from nasal biopsies from patients with Wegener’s granulomatosis and pathogenic antibodies from systemic lupus erythematosus do not appear to be as stringently selected for structural integrity as other groups of functional sequences.

Type 2 diabetes and hypertension in older adults: a case study

The management of long-term conditions in the older adult population can be challenging and complex. After examining the literature and exploring some common issues, this article uses a reflective case study to demonstrate key findings in the management of hypertension and diabetes in an older adult that can be used to support effective interventions and positive outcomes.

The energy dependence syndrome

Two major global problems face mankind in the forthcoming decades. The rapidly increasing populations, especially in developing countries, are already causing social and economic strain in many areas, and the escalating demand for energy at both the individual and collective levels are matters requiring serious global attention. The product of increasing population and increasing energy demand compounds both problems. The origins of both population increase and escalating demand for energy originate behaviourally. That is to say that, theoretically, if the human behaviour underlying these problems could be modified, either voluntarily on an individual basis, or by educational, legislative or correctional means, then these worrying trends could be brought under control. This paper is concerned principally with the underlying behaviours and dynamics of energy usage by human beings as the present trend of ever-increasing consumption which seems to be directionless and illogical is very similar to another group of existing behavioural disorder known as addiction behaviours or dependency. These behaviours have recently received much attention and research and some of the strategies for dealing with them may be of considerable use in modifying and controlling both the per caput and collective use of energy.

A freeze-dried formulation of bacteriophage encapsulated in biodegradable microspheres

With the emergence of widespread antibiotic resistance, there has been renewed interest in the use of bacteriophages. While their potency, safety and specificity have underpinned their clinical potential, to date, little work has been focussed on their formulation with respect to controlled release and/or passive targeting. Here, we show that bacteriophages selective for Staphylococcus aureus or Pseudomonas aeruginosa can be encapsulated into biodegradable polyester microspheres via a modified w/o/w double emulsion-solvent extraction protocol with only a partial loss of lytic activity. Loss of lytic activity could be attributed to the exposure of the bacteriophages to the water-dichloromethane interface, with the lyophilization process itself having little effect. The microspheres were engineered to have an appropriate size and density to facilitate inhalation via a dry-powder inhaler and fluorescently labeled bacteriophages were distributed entirely within the internal porous matrix. The release profile showed a burst release phase (55-63% release within 30 min), followed by a sustained release till around 6h, as appropriate for pulmonary delivery. Despite the poor shelf-life of the formulation, the work is proof-of-concept for the formulation and controlled delivery of bacteriophages, as suitable for the treatment of bacterial lung infections.

Extensive perineal soft tissue disruption with 'open-book' pelvic fracture

We present a case in which direct visualisation of the nature and extent of a perineal soft tissue injury following pelvic trauma was achieved through the use of multi-modality and multi-planar imaging. The case emphasises the importance of a flexible approach to imaging as a problem-solving technique after severe pelvic trauma.

A survey of follow-up practice of urologists across Britain and Ireland following nephrectomy for renal cell carcinoma

AIM

To determine the follow-up protocol for interval assessment of patients following radical nephrectomy for renal cell cancer and to compare them with the recommendations proposed in the literature.

METHODS

Consultant urologists across Britain and Ireland completed a postal questionnaire. One follow-up mailing was used to encourage non-responders. The responses were analysed in the light of the recommendations from European Association of Urology and American guidelines. Also information was collected from the respondents on the choice of follow-up investigations for renal cell cancer and the total duration of follow-up.

RESULTS

Of the 480 urologists surveyed 292 (60.8%) responded. Most respondents recommended regular follow-up with chest radiography (CR), ultrasound and computed tomography (CT). For T1 disease CR was requested by 28, 62 and 55%; for T2 disease by 30, 66 and 51%; for T3 disease by 39, 63, and 48% at 3, 6 and 12 months, respectively. For T1 disease US was requested by 5, 23 and 30%; for T2 disease 6, 27 and 30%; for T3 disease 8, 25, and 26% at 3, 6 and 12 months, respectively. For T1 disease an abdominal CT was requested by 2, 17 and 21%; for T2 disease 3.7, 19.5 and 26%; for T3 disease 10, 31, and 33% at 3, 6 and 12 months, respectively. Only one respondent followed the guidelines suggested in the literature. Further follow-up after 12 months for 5 and 10 years was suggested by 58.2 and 21.3% for T1, 53 and 24.73% for T2, and 45.5 and 25.5% for T3, respectively. There is appreciable variation in the frequency of use and timing of imaging.

CONCLUSIONS

Most respondents perform follow-up after radical nephrectomy in patients with renal cancer, with considerable variability in their practices. In the current increasingly cost-conscious healthcare industry a scientifically justified follow-up should be considered.

Utility of biochemical screening in the context of evaluating patients with a presumptive diagnosis of osteoporosis

The ageing population is expected to increase the burden of osteoporosis on the health care system. Secondary causes of osteoporosis are found in a proportion of patients. There is much controversy regarding the best work-up for patients who have been diagnosed as having osteoporosis based on bone mineral density. It is difficult to decide where interventions should be targeted both from a patient's perspective and for cost effectiveness. We evaluated the utility of a standard panel (full blood count, plasma viscosity, plasma protein, electrophoresis, urine Bence Jones protein, thyroid function test, bone profile, fasting lipids and liver function test) of biochemical investigations in 327 consecutive patients (287 females, 40 males) referred to the new patient osteoporosis clinic from April 1999 to March 2000. Patients were characterised after measurement of spinal/femoral neck bone mineral density after a dual energy X-ray absorptiometry (DEXA) scan. There were 88 patients with osteoporosis, 91 with osteopenia, 130 had normal bone mineral density and 20 who did not have a bone scan. No case of multiple myeloma was found in this cohort of patients. There was no difference in the mean plasma viscosity of patients with and without osteoporosis (P=0.182). There was no significant difference in the abnormal urine calcium/creatinine (Ca/Cr ratio) in patients with osteoporosis and those without osteoporosis (P=0.316). There was no significant difference in the prevalence of hypothyroidism (P=0.213) or thyrotoxicosis (P=0.138) in patients with and without osteoporosis. There was no strong correlation between cholesterol concentrations and osteoporosis (r=0.069). We found no utility in performing a myeloma screen. A small proportion of patients had abnormalities of calcium homeostasis or thyroid disease. We recommend that a screening biochemical evaluation should be restricted to calcium/bone profile and thyroid function tests in patients with a presumptive diagnosis of osteoporosis.

How can experience in clinical and community settings contribute to early medical education? A BEME systematic review

REVIEW DATE

Review period January 1992-December 2001. Final analysis July 2004-January 2005. BACKGROUND AND REVIEW CONTEXT: There has been no rigorous systematic review of the outcomes of early exposure to clinical and community settings in medical education. OBJECTIVES OF REVIEW: Identify published empirical evidence of the effects of early experience in medical education, analyse it, and synthesize conclusions from it. Identify the strengths and limitations of the research effort to date, and identify objectives for future research.

SEARCH STRATEGY

Ovid search of: BEI, ERIC, Medline, CINAHL and EMBASE Additional electronic searches of: Psychinfo, Timelit, EBM reviews, SIGLE, and the Cochrane databases. Hand-searches of:Medical Education, Medical Teacher, Academic Medicine, Teaching and Learning in Medicine, Advances in Health Sciences Education, Journal of Educational Psychology.

CRITERIA

DEFINITIONS

EXPERIENCE

Authentic (real as opposed to simulated) human contact in a social or clinical context that enhances learning of health, illness and/or disease, and the role of the health professional. Early: What would traditionally have been regarded as the preclinical phase, usually the first 2 years. Inclusions: All empirical studies (verifiable, observational data) of early experience in the basic education of health professionals, whatever their design or methodology, including papers not in English. Evidence from other health care professions that could be applied to medicine was included.

EXCLUSIONS

Not empirical; not early; post-basic; simulated rather than 'authentic' experience.

DATA COLLECTION

Careful validation of selection processes. Coding by two reviewers onto an extensively modified version of the standard BEME coding sheet. Accumulation into an Access database. Secondary coding and synthesis of an interpretation.

HEADLINE RESULTS

A total of 73 studies met the selection criteria and yielded 277 educational outcomes; 116 of those outcomes (from 38 studies) were rated strong and important enough to include in a narrative synthesis of results; 76% of those outcomes were from descriptive studies and 24% from comparative studies. Early experience motivated and satisfied students of the health professions and helped them acclimatize to clinical environments, develop professionally, interact with patients with more confidence and less stress, develop self-reflection and appraisal skill, and develop a professional identity. It strengthened their learning and made it more real and relevant to clinical practice. It helped students learn about the structure and function of the healthcare system, and about preventive care and the role of health professionals. It supported the learning of both biomedical and behavioural/social sciences and helped students acquire communication and basic clinical skills. There were outcomes for beneficiaries other than students, including teachers, patients, populations, organizations and specialties. Early experience increased recruitment to primary care/rural medical practice, though mainly in US studies which introduced it for that specific purpose as part of a complex intervention.

CONCLUSIONS

Early experience helps medical students socialize to their chosen profession. It helps them acquire a range of subject matter and makes their learning more real and relevant. It has potential benefits for other stakeholders, notably teachers and patients. It can influence career choices.