18 research outputs found
Fibrin-mediated Protection Against Infection-stimulated Immunopathology
Fibrin, a product of the blood coagulation cascade, accompanies many type 1 immune responses, including delayed-type hypersensitivity, autoimmunity, and graft rejection. In those settings, fibrin is thought to exacerbate inflammation and disease. Here, we evaluate roles for coagulation during infection with Toxoplasma gondii, a pathogen whose control requires robust type 1 immunity. We establish that fibrin prevents infection-stimulated blood loss, thereby performing a protective function that is essential for survival. Remarkably, fibrin does not simply protect against vascular damage caused directly by the infectious agent, but rather, protects against hemorrhage evoked by interferon-γ, a critical mediator of type 1 immunity. This finding, to our knowledge, is the first to document a beneficial role for coagulation during type 1 immunity, and suggests that fibrin deposition protects host tissue from collateral damage caused by the immune system as it combats infection
12-Month progression of motor and functional outcomes in congenital myotonic dystrophy
Background: We aim to describe 12-mo functional and motor outcome performance in a cohort of participants with congenital myotonic dystrophy (CDM). Methods: CDM participants performed the 6 Minute Walk Test (6MWT), 10 Meter Run, 4 Stair Climb, Grip Strength, and Lip Force at baseline and 12-mo visits. Parents completed the Vineland Adaptive Behavior Scale. Results: Forty-seven participants, aged 0 to 13 y old, with CDM were enrolled. 6MWT, 10 Meter Run, and 4 Stair Climb were completed in \u3e85% of eligible participants. The only significant difference between mean baseline and 12-mo performance was an improvement in 6MWT in children 3-6 y old (P =.008). This age group also had the largest mean % improvement in performance in all other timed functional testing. In children \u3e7 y, the slope of change on timed functional tests decreased or plateaued, with further reductions in performance in children ≥10 y. Participants with CTG repeat lengths \u3c500 did not perform differently than those with repeat lengths \u3e1000. Conclusions: The 6MWT, 10 Meter Run, and 4 Stair Climb were the most feasible measures. Our findings are consistent with the clinical profile and prior cross-sectional data, helping to establish reasonable expectations of functional trajectories in this population as well as identifying points in which therapeutic interventions may be best studied. Further study of outcomes in children \u3e10 y old and \u3c3 y is warranted, but this new information will assist planning of clinical trials in the CDM population
Consensus-based care recommendations for congenital and childhood-onset myotonic dystrophy type 1
Purpose of reviewMyotonic dystrophy type 1 is a multisystemic disorder caused by a noncoding triplet repeat. The age of onset is variable across the lifespan, but in its most severe form, the symptoms appear at birth (congenital myotonic dystrophy) or in the pediatric age range (childhood-onset myotonic dystrophy). These children have a range of disabilities that reduce the lifespan and cause significant morbidity. Currently, there are no agreed upon recommendations for caring for these children.Recent findingsThe Myotonic Dystrophy Foundation recruited 11 international clinicians who are experienced with congenital and childhood-onset myotonic dystrophy to create consensus-based care recommendations. The experts used a 2-step methodology using elements of the single text procedure and nominal group technique. Completion of this process has led to the development of clinical care recommendations for this population.SummaryChildren with myotonic dystrophy often require monitoring and interventions to improve the lifespan and quality of life. The resulting recommendations are intended to standardize and improve the care of children with myotonic dystrophy
Disease Burden and Functional Outcomes in Congenital Myotonic Dystrophy: A Cross-Sectional Study
OBJECTIVE: Herein, we describe the disease burden and age-related changes of congenital-onset myotonic dystrophy (CDM) in childhood.
METHODS: Children with CDM and age-matched controls aged 0 to 13 years were enrolled. Participants were divided into cohorts based on the following age groups: 0-2, 3-6, and 7-13 years. Each cohort received age-appropriate evaluations including functional testing, oral facial strength testing, neuropsychological testing, quality-of-life measurements, and ECG. Independent-samples t test or Wilcoxon 2-sample test was used to compare the differences between children with CDM and controls. Probability values less than 0.05 are reported as significant.
RESULTS: Forty-one participants with CDM and 29 healthy controls were enrolled. The 6-minute walk was significantly different between CDM (258.3 m [SD 176.0]) and control participants (568.2 m [SD 73.2]). The mean lip force strength was significantly different in CDM (2.1 N [SD 2.8)] compared to control participants (17.8 N [SD 7.6]). In participants with CDM, the mean IQ (65.8; SD 18.4) was 3 SDs below the mean compared to standardized norms. Measurements of grip strength, sleep quality, and quality of life were also significantly different. Strength measures (oral facial strength, grip strength, and 6-minute walk) correlated with each other but not with participant IQ.
CONCLUSIONS: This work identifies important phenotypes associated with CDM during childhood. Several measures of strength and function were significantly different between participants with CDM and controls and may be useful during future therapeutic trials
Consensus-based care recommendations for adults with myotonic dystrophy type 1
Purpose of review
Myotonic dystrophy type 1 (DM1) is a severe, progressive genetic disease that affects between 1 in 3,000 and 8,000 individuals globally. No evidence-based guideline exists to inform the care of these patients, and most do not have access to multidisciplinary care centers staffed by experienced professionals, creating a clinical care deficit.
Recent findings
The Myotonic Dystrophy Foundation (MDF) recruited 66 international clinicians experienced in DM1 patient care to develop consensus-based care recommendations. MDF created a 2-step methodology for the project using elements of the Single Text Procedure and the Nominal Group Technique. The process generated a 4-page Quick Reference Guide and a comprehensive, 55-page document that provides clinical
care recommendations for 19 discrete body systems and/or care considerations.
Summary
The resulting recommendations are intended to help standardize and elevate care for this patient population and reduce variability in clinical trial and study environments. Described as “one of the more variable diseases found in medicine,” myotonic dystrophy type
1 (DM1) is an autosomal dominant, triplet-repeat expansion disorder that affects somewhere between 1:3,000 and 1:8,000 individuals worldwide.1 There is a modest association between increased repeat expansion and disease severity, as evidenced by the average age of onset and overall morbidity of the condition. An expansion of over 35 repeats typically indicates an unstable and expanding mutation. An expansion of 50 repeats or higher is consistent with a diagnosis of DM1. DM1 is a multisystem and heterogeneous disease characterized by distal weakness, atrophy, and myotonia, as well as symptoms in the heart, brain, gastrointestinal tract, endocrine, and respiratory systems. Symptoms may occur at any age. The severity of the condition varies widely among affected individuals, even among members of the same family.
Comprehensive evidence-based guidelines do not currently
exist to guide the treatment of DM1 patients. As a result, the international patient community reports varied levels of care and care quality, and difficulty accessing care adequate to manage their symptoms, unless they have access to multidisciplinary neuromuscular clinics.
Consensus-based care recommendations can help standardize
and improve the quality of care received by DM1 patients
and assist clinicians who may not be familiar with the significant variability, range of symptoms, and severity of the disease. Care recommendations can also improve the landscape for clinical trial success by eliminating some of the inconsistencies in patient care to allow more accurate understanding of the benefit of potential therapies
Feasibility of A Novel Treatment of Abstract Verbs in Aphasia and Apraxia of Speech
Introduction
Models of sentence meaning emphasize the central role of the verb (Fillmore, 1968; Miller, 1972). These models are the theoretical basis of language production treatments for persons with aphasia such as VNeST (Edmonds, Nadeau, & Kiran, 2009) and “verb is core” treatment (Loverso, Selinger, & Prescott, 1979). However, these treatments have focused on concrete verbs, despite evidence pointing to the frequency of abstract verbs in spoken language (Renvall, Nickels, & Davidson, 2013) and recent evidence supporting the trainability of abstract concepts in persons with aphasia (Kiran, Sandberg, & Abbott, 2009). This study was designed to examine the efficacy of a novel treatment on production of sentences with abstract verbs, in two persons with nonfluent aphasia and apraxia of speech (AOS).
Methods
Participants
Two patients with chronic Broca’s aphasia and AOS due to CVA were enrolled as participants. Extensive pretreatment testing was performed and will be discussed. This testing included assessments of argument structure production, abstract versus concrete lexical access, sentence repetition, speech rate, and narrative discourse.
Treatment Description
The treatment was largely based on VNeST (Edmonds et al., 2009). Due to lack of imageable stimuli, written and verbal models of the target word were given, along with a request for a sentence with subject and object arguments. Elements of RET (Kearns, 1985) were added to facilitate expansion of initial attempts. Suggestions for expansions were predominantly taken from a corpus (Davies, 2008-2012) to increase ecological validity of practiced sentences. Also, a contrastive stress exercise was included as an AOS treatment component to provide additional motor practice and facilitate flexibility of speech motor plans. Treatment was administered three times per week by certified SLPs and a supervised clinical fellow.
Experimental Design
The experimental design was a multiple baseline single-subject design across behaviors and participants.
Dependent Measure
Treatment probes were conducted prior to each second treatment session. Probes included written and verbal models of the target verb, along with an instruction to create a sentence with the target verb that included a “doer” (subject) and an object. Complete instructions will be provided. Probes were scored based on a novel system that emphasized semantic relatedness and plausibility of arguments and order of sentence elements.
Stimuli
Lexical verbs with high frequencies (Brysbaert & New, 2009) and SVO argument structures were selected as stimuli. Concreteness ratings (Brysbaert, Warriner, & Kuperman, 2014) were used to sort verbs into three abstract lists and one concrete list. Treatment was intended for two of the abstract lists, with the other lists for measuring response generalization.
Results
Results were been obtained for the first of two planned treatment phases for both participants. Results indicated improved sentence production attributable to the treatment for one of the two participants. The Conservative Dual Criterion (CDC; Swoboda, Kratochwill, & Levin, 2010) was used to aid in visual inspection of graphed probe data. These results indicate the feasibility of the treatment for increasing sentence production with abstract verbs in persons with chronic aphasia and AOS
Cell-Mediated Protection against Pulmonary Yersinia pestis Infection
Pulmonary infection with the bacterium Yersinia pestis causes pneumonic plague, an often-fatal disease for which no vaccine is presently available. Antibody-mediated humoral immunity can protect mice against pulmonary Y. pestis infection, an experimental model of pneumonic plague. Little is known about the protective efficacy of cellular immunity. We investigated the cellular immune response to Y. pestis in B-cell-deficient μMT mice, which lack the capacity to generate antibody responses. To effectively prime pulmonary cellular immunity, we intranasally vaccinated μMT mice with live replicating Y. pestis. Vaccination dramatically increased survival of μMT mice challenged intranasally with a lethal Y. pestis dose and significantly reduced bacterial growth in pulmonary, splenic, and hepatic tissues. Vaccination also increased numbers of pulmonary T cells, and administration of T-cell-depleting monoclonal antibodies at the time of challenge abrogated vaccine-induced survival. Moreover, the transfer of Y. pestis-primed T cells to naive μMT mice protected against lethal intranasal challenge. These findings establish that vaccine-primed cellular immunity can protect against pulmonary Y. pestis infection and suggest that vaccines promoting both humoral and cellular immunity will most effectively combat pneumonic plague
Yersinia pestis V Protein Epitopes Recognized by CD4 T Cells
Pneumonic plague, an often-fatal disease for which no vaccine is presently available, results from pulmonary infection by the bacterium Yersinia pestis. The Y. pestis V protein is a promising vaccine candidate, as V protein immunizations confer to mice significant protection against aerosolized Y. pestis. CD4 T cells play central roles during vaccine-primed immune responses, but their functional contributions to Y. pestis vaccines have yet to be evaluated and optimized. Toward that end, we report here the identification of three distinct epitopes within the Y. pestis V protein that activate CD4 T cells in C57BL/6 mice. To our knowledge, these are the first identified CD4 T-cell epitopes in any Y. pestis protein. The epitopes are restricted by the I-A(b) class II major histocompatibility complex molecule and are fully conserved between Y. pestis, Yersinia pseudotuberculosis, and Yersinia enterocolitica. Immunizing mice with a V protein-containing vaccine or with short peptides containing the identified epitopes primes antigen-specific production of interleukin 2 and gamma interferon by CD4 T cells upon their restimulation in vitro. Consistent with prior studies documenting protective roles for CD4 T cells during Y. enterocolitica infection, vaccinating mice with a 16-amino-acid peptide encoding one of the epitopes suffices to protect against an otherwise lethal Y. enterocolitica challenge. The identification of these epitopes will permit quantitative assessments of V-specific CD4 T cells, thereby enabling researchers to evaluate and optimize the contribution of these cells to vaccine-primed protection against pneumonic plague