Analysis of the Protein Kinase A-Regulated Proteome of Cryptococcus neoformans Identifies a Role for the Ubiquitin-Proteasome Pathway in Capsule Formation.

UNLABELLED: The opportunistic fungal pathogen Cryptococcus neoformans causes life-threatening meningitis in immunocompromised individuals. The expression of virulence factors, including capsule and melanin, is in part regulated by the cyclic-AMP/protein kinase A (cAMP/PKA) signal transduction pathway. In this study, we investigated the influence of PKA on the composition of the intracellular proteome to obtain a comprehensive understanding of the regulation that underpins virulence. Through quantitative proteomics, enrichment and bioinformatic analyses, and an interactome study, we uncovered a pattern of PKA regulation for proteins associated with translation, the proteasome, metabolism, amino acid biosynthesis, and virulence-related functions. PKA regulation of the ubiquitin-proteasome pathway in C. neoformans showed a striking parallel with connections between PKA and protein degradation in chronic neurodegenerative disorders and other human diseases. Further investigation of proteasome function with the inhibitor bortezomib revealed an impact on capsule production as well as hypersusceptibility for strains with altered expression or activity of PKA. Parallel studies with tunicamycin also linked endoplasmic reticulum stress with capsule production and PKA. Taken together, the data suggest a model whereby expression of PKA regulatory and catalytic subunits and the activation of PKA influence proteostasis and the function of the endoplasmic reticulum to control the elaboration of the polysaccharide capsule. Overall, this study revealed both broad and conserved influences of the cAMP/PKA pathway on the proteome and identified proteostasis as a potential therapeutic target for the treatment of cryptococcosis. IMPORTANCE: Fungi cause life-threatening diseases, but very few drugs are available to effectively treat fungal infections. The pathogenic fungus Cryptococcus neoformans causes a substantial global burden of life-threatening meningitis in patients suffering from HIV/AIDS. An understanding of the mechanisms by which fungi deploy virulence factors to cause disease is critical for developing new therapeutic approaches. We employed a quantitative proteomic approach to define the changes in the protein complement that occur upon modulating the cAMP signaling pathway that regulates virulence in C. neoformans. This approach identified a conserved role for cAMP signaling in the regulation of the ubiquitin-proteasome pathway and revealed a link between this pathway and elaboration of a major virulence determinant, the polysaccharide capsule. Targeting the ubiquitin-proteasome pathway opens new therapeutic options for the treatment of cryptococcosis.

Home-based rehabilitation for people with stroke: a comparative study of six community services providing co-ordinated, multidisciplinary treatment.

OBJECTIVE: To describe and compare six community services providing co-ordinated, multidisciplinary rehabilitation to people with stroke. DESIGN: Prospective, descriptive, quantitative study. SETTING: England and Northern Ireland. SUBJECTS: Community rehabilitation teams and the patients treated by them. MAIN OUTCOME MEASURES: Annual numbers treated, Barthel Index, mortality, place of discharge, crude costs. RESULTS: Between mid-1997 and mid-1999, data were collected on 1076 patients who received community-based rehabilitation of whom 48.7% were male. Mean age (SD) was 71 years (13.11; 115 (10.7%) were under 55 years of age and 278 (25.9%) under 65 years of age. Median time between stroke and intervention by the community service was six weeks (25th, 75th percentiles 2.6, 14.4 weeks) and 80.5% had been admitted to hospital. The median Barthel score at the start of community rehabilitation was 15 (11.0, 18.0) and at the end was 18.0 (14.0, 20.0). Median duration of intervention was 12 weeks (6.0, 22.0). At the end of community rehabilitation 912 patients (86.5%) were in the community, 52 (4.9%) had died, 10 (0.9%) were in hospital and 77 (7.3%) in long-term care. Comparative data given here are for one year, 1998, when a total of 519 patients began community rehabilitation. Details of 1855 face-to-face interventions were also recorded from subsets of 10 consecutive patients. CONCLUSIONS: Community rehabilitation teams differed in their target populations, in the timing and duration of intervention. A taxonomy of four types of co-ordinated community-based rehabilitation for people with stroke is proposed: (1) Early-supported discharge rehabilitation aimed to reduce length of hospital stay and offered an alternative to hospital rehabilitation. (2) Post-discharge rehabilitation provided additional rehabilitation and aimed for a seamless transfer of patients from hospital to community. (3) General practitioner-oriented post-stroke rehabilitation provided an alternative to hospital admission and rehabilitation. (4) Late community rehabilitation provided patients with the opportunity of an autonomous service, unconnected with hospital or GP referral. Purchasers need to decide for what purpose a team is to be set up. Researchers need to be similarly aware of diversity in community rehabilitation before comparisons are made.

The Leeds Assessment Scale of Handicap: its operationalisation, reliability, validity and responsiveness in in-patient rehabilitation.

PURPOSE: This paper describes the application of the handicap dimension of the International Classification of Impairments, Disabilities and Handicaps. METHOD: A method of assessing four of the six roles (or areas of expected competency) was developed and applied to an in-patient population, aged 16 to 65 years, receiving specialist rehabilitation following neurological damage. Handicap assessment was a collaborative process by a multidisciplinary team. Difficulties were experienced in measuring inter-rate reliability in the busy, clinical setting. RESULTS: We conclude that handicap assessment in an in-patient rehabilitation unit which uses a multidisciplinary approach to treating patients with complex physical, sensory and cognitive problems is both feasible and useful. CONCLUSION: The developed scale, The Leeds Assessment Scale of Handicap, provides a valid and valuable summary of human disadvantage, complementing the common disability assessments.

The influence of prior stroke on the prosthetic rehabilitation of lower limb amputees.

Concurrent stroke is believed to have an adverse influence on the process and outcome of prosthetic rehabilitation, but there is limited published evidence for this. The aim of this study was to establish a clearer picture in order to assist decision making for both patients and professionals. Demographic and clinical data were collected from all lower limb amputees referred from North and West Yorkshire for prosthetic rehabilitation. Additional data were collected from all new lower limb amputees in three of the referring health districts, irrespective of prosthetic referral. Patients with prior stroke were less likely to be referred for prosthetic rehabilitation. Improved mobility and independence were seen following prosthetic rehabilitation irrespective of prior stroke. The group with prior stroke compared well with the non-stroke group in terms of walking aid usage, but a smaller proportion of the stroke group were able to walk 30 m without stopping and there were trends for smaller gains in independence in the stroke group. Nevertheless, this study demonstrates that prosthetic rehabilitation can be successful in a selected amputee population with prior stroke. In those who continue prosthetic use for one year, outcome is similar to that in patients without stroke.

Outcome following stroke.

A community study based on an age-stratified sample of those aged 55 years and older in a northern health district in the United Kingdom has been used to consider the implications for purchasing health-care services for those who have survived a stroke. The study showed that while almost a quarter of those reporting a stroke had made a full recovery, a wide range of impairments and disabilities persisted. Almost half reported needing help at least daily. A logistic regression model to predict this level of dependency found that impairments, disabilities and other factors, such as locality, were also predictive of dependency. A second model predicting mobility handicap (dwelling restricted) was found to have a similar mix of predictors. These results show how purchasers must consider the broad outcome in terms of a continuum of impairment, disability and handicap. The results also show that handicap is a distinct concept that draws together many influences which act upon the individual.

Prevalence of self reported stroke in a population in northern England.

STUDY OBJECTIVE: The aim of this study was to determine the prevalence of stroke survivors in a health district population aged 55 years and over. DESIGN: This was a point prevalence study using two-stage postal questionnaires sent to an age stratified random sample of the population. SETTING: A district health authority in northern England with a resident population of 723,000. SUBJECTS: Altogether 18,827 residents aged 55 years or over. MAIN RESULTS: Prevalence was found to increase with age and, apart from the very elderly, males had a higher prevalence than females. Overall prevalence was found to be 46.8/1,000 (95% CI 42.5, 51.6). 23% of respondents reported full recovery from stroke. Cognitive impairments (33%), problems with lower limbs (33% for right leg; 27% for left leg) and speech difficulties (27%) were the most common residual impairments. CONCLUSIONS: Current guidelines to purchasers on the provision of services to those who have had a stroke may under-estimate prevalence rates by as much as 50%. This could lead to a shortfall in provision of services designed to support people in the months and years following their stroke.