Identification of hepatitis A virus mimotopes by phage display, antigenicity and immunogenicity

A phage-displayed peptide approach was used to identify ligands mimicking antigenic determinants of hepatitis A virus (HAV) for the first time. Bacteriophages displaying HAV mimotopes were isolated from a phage-display peptide library by affinity selection on serum antibodies from hepatitis A patients. Selected phage-peptides were screened for reactivity with sera from HAV infected patients and healthy controls. Four cloned peptides with different sequences were identified as mimotopes of HAV; three of them showed similarity in their amino acid sequences with at least one of the VP3 and VP1 antigenic proteins of HAV. One clone was recognised by 92% of the positive sera. The phagotopes competed effectively with HAV for absorption of anti-HAV-specific antibodies in human sera, as determined by ELISA. The four phage clones induced neutralising anti-HAV antibodies in immunised mice. These results demonstrate the potential of this method to elucidate the disease related epitopes of HAV and to use these mimotopes in diagnostic applications or in the development of a mimotope-based hepatitis A vaccine without the necessity of manipulation of the virus.     

Outcome measures to assess walking ability following stroke: a systematic review of the literature

Objectives

The recovery of independent walking is an important goal in stroke rehabilitation. The objective of this systematic review was to identify all outcome measures used in the stroke research literature that included an evaluation of walking ability and evaluate the concepts contained in these measures with reference to the International Classification of Functioning, Disability and Health (ICF) framework.

Data sources

Searches were conducted of MEDLINE, CINAHL, EMBASE and PsycINFO databases for the time period January 1990-December 2005 using appropriate keywords.

Review methods

Studies were selected for further analysis if they used one or more standardized outcome measure incorporating an aspect of walking defined by the ICF. The outcome measure had to have published psychometric properties and specifically measure walking rather than mobility. The content of each outcome measure was classified with reference to the ICF subcategories for walking. The number of times each outcome measure was used was calculated.

Results

Three hundred and fifty-seven studies met the selection criteria. Sixty-one different outcome measures were used a total of 848 times to measure walking ability. Six of the outcome measures reflected impairment and 52 reflected limitations of activity and participation. The other three outcome measures showed overlap between domains, reflecting aspects of both impairment and limitations in activity and participation. The three most frequently used measures (self-paced gait speed measured over a short distance, spatiotemporal parameters and fast gait speed) were used 350 times but only assessed one ICF subcategory. The Rivermead Mobility Index and the Adapted Patient Evaluation Conference System assessed the greatest number of ICF subcategories but were used only 19 times and once respectively.

Conclusions

The most frequently used outcome measures reflect only one aspect of walking ability: walking short distances. Mobility tasks related to function in the community, like walking long distances, around obstacles and over uneven ground, and moving around outside or in buildings other then the home are not well represented by outcome measures used in most studies.     

The Effectiveness of an Internet Support Forum for Carers of People With Dementia: A Pre-Post Cohort Study

Background

The well-being of informal carers of people with dementia is an important public health issue. Caring for an elderly relative with dementia may be burdensome and stressful, and can negatively affect the carer’s social, family, and professional life. The combination of loss, the physical demands of caregiving, prolonged distress, and biological vulnerabilities of older carers may compromise their physical health, increase social isolation, and increase the risk of anxiety and depressive disorders. Caregiver stress is also linked to negative outcomes for the recipient of care and costs to society, including increased nursing home and hospital admissions. Consequently, carer support interventions are an important component of dementia care. Computer-mediated carer support offers a range of potential advantages compared to traditional face-to-face support groups, including accessibility and the possibility of tailoring to meet individual needs, but there has been little research on its effectiveness so far.

Objective

This mixed-methods study examined the impact of a well-respected UK-based online support forum for carers of people with dementia.

Methods

A total of 61 new forum users completed measures of anxiety (7-item Generalized Anxiety Disorder scale, GAD-7), depression (9-item Patient Health Questionnaire, PHQ-9), and quality of relationship with the person with dementia (Scale for the Quality of the Current Relationship in Caregiving, SQCRC), at baseline and again after 12 weeks of forum usage, within a pre-post design. In addition, 8 participants were interviewed about their experiences with using the forum.

Results

There was an improvement in the quality of the relationship with the person with dementia (SQCRC: P=.003). There was no change in users’ depression (PHQ-9) or anxiety (GAD-7) over the 12-week study period. Interview participants reported a range of positive experiences and benefits from using the forum. Limited negative experiences were also reported.

Conclusions

Many of the reported experiences and benefits are unique to online peer support. Further research into online peer support for carers of people with dementia is needed to clarify who benefits under what conditions.     

A study of the use of maternity and child welfare clinics in case-finding for pulmonary tuberculosis in Kenya

This investigation is the seventh in a series of case-finding studies in Kenya. It explores the potential value of questioning mothers attending maternity and child welfare (M & CW) clinics to identify tuberculosis suspects (individuals aged 6 years or more with a cough for 1 month or more or hemoptysis) living in their households. The study was carried out in all the eight M & CW clinics in two divisions (populations 86,000 and 112,000) of two different districts. The mothers were asked to give a standard letter, which explained the possible importance of a chronic cough, to each suspect they identified and invited the suspect to attend the district hospital chest clinic. Each suspect attending the clinic was entered in a special register and two sputum specimens were collected. For those who failed to attend, the specimens were collected at a home visit. Of the total of 342 suspects living in the two study areas who were registered at the M & CW clinics during 1 year, 261 were identified by the mothers but 19 denied having received the standard letter. The remaining 81 had not been identified by mothers but had attended the M & CW clinics on their own initiative. Of the 242 suspects who received the letter, 89 (39%) attended the hospital chest clinic, 74% within a week of the letter being issued from the M & CW clinic. The main reasons given for not attending the hospital chest clinic by the remaining suspects were financial or because their cough had improved or disappeared. Sputum was collected from 238 suspects and examined bacteriologically: in six (2.5%) it was positive for tubercle bacilli on smear and culture and in a further two (0.8%) the sputum was positive on culture only. Of those attending the hospital chest clinic 2.9% were smear- and culture-positive and 4.7% were culture positive. This method of case-finding has yielded disappointing results, for only 4% of the estimated annual incidence of smear-positive cases was detected.     

Older people with cancer: perceptions and feelings about information, decision-making and treatment--a pilot study.

Several studies have identified inadequacies in the care and treatment received by older patients with cancer, as opposed to their younger counterparts. These include over or under diagnosis, ineffective symptom management and lower survival rates in older people with cancer. Despite these inadequacies, there is lack of evidence of older peoples' perspectives regarding their cancer diagnosis and treatment. This on going 2-site hospital based study focuses on older people's perceptions of information and decision-making in relation to treatment for cancer by using a semi-structured interview schedule. Results of the pilot study with 6 patients are presented and discussed in the light of research and clinical implications.     

Phenomics: the systematic study of phenotypes on a genome-wide scale

Phenomics is an emerging transdiscipline dedicated to the systematic study of phenotypes on a genome-wide scale. New methods for high-throughput genotyping have changed the priority for biomedical research to phenotyping, but the human phenome is vast and its dimensionality remains unknown. Phenomics research strategies capable of linking genetic variation to public health concerns need to prioritize development of mechanistic frameworks that relate neural systems functioning to human behavior. New approaches to phenotype definition will benefit from crossing neuropsychiatric syndromal boundaries, and defining phenotypic features across multiple levels of expression from proteome to syndrome. The demand for high throughput phenotyping may stimulate a migration from conventional laboratory to web-based assessment of behavior, and this offers the promise of dynamic phenotyping—the iterative refinement of phenotype assays based on prior genotype-phenotype associations. Phenotypes that can be studied across species may provide greatest traction, particularly given rapid development in transgenic modeling. Phenomics research demands vertically integrated research teams, novel analytic strategies and informatics infrastructure to help manage complexity. The Consortium for Neuropsychiatric Phenomics at UCLA has been supported by the National Institutes of Health Roadmap Initiative to illustrate these principles, and is developing applications that may help investigators assemble, visualize, and ultimately test multi-level phenomics hypotheses. As the transdiscipline of phenomics matures, and work is extended to large-scale international collaborations, there is promise that systematic new knowledge bases will help fulfill the promise of personalized medicine and the rational diagnosis and treatment of neuropsychiatric syndromes.     

Identification of alloreactive T-cell epitopes on the Rhesus D protein

Although considerable effort has been devoted to characterizing alloantibodies specific for the Rhesus D (RhD) blood group antigen, virtually nothing is known about the helper response that drives their production. Therefore, the aim of this study was to map alloreactive T-cell epitopes on the RhD protein. Peripheral blood mononuclear cells (PBMCs) were obtained from 22 RhD-negative volunteers in whom anti-D alloantibodies had developed after deliberate immunization or RhD-incompatible pregnancy. The PBMCs were stimulated with a panel of up to 68 overlapping synthetic 15-mer peptides spanning the complete sequence of the RhD protein. One or more peptides elicited proliferative responses by PBMCs from all 22 of the alloimmune volunteers but from only 2 of 8 alloantibody-negative control donors. Proliferation of PBMCs from the alloimmune donors was mediated by major histocompatibility complex class II-restricted T cells expressing the CD45RO marker of previous activation or memory. The number of peptides that induced proliferative responses was unrelated to either the frequency of, or time since, exposure to RhD-positive red blood cells, but it correlated strongly (R(s) = 0.75; P <.003) with the level of anti-D antibodies in deliberately immunized donors. The patterns of stimulatory peptides varied among alloimmune volunteers, but particular sequences were commonly recognized, with 4 peptides each eliciting a response in more than 50% of these donors. Identification of such peptides containing dominant alloreactive helper epitopes is the first step in the development of improved or new approaches to preventing hemolytic disease of the newborn that are based on modulating the T-cell response to the RhD protein.