24 research outputs found
Brownian bridges to submanifolds
We introduce and study Brownian bridges to submanifolds. Our method involves
proving a general formula for the integral over a submanifold of the minimal
heat kernel on a complete Riemannian manifold. We use the formula to derive
lower bounds, an asymptotic relation and derivative estimates. We also see a
connection to hypersurface local time. This work is motivated by the desire to
extend the analysis of path and loop spaces to measures on paths which
terminate on a submanifold
Pilot trial of simvastatin in the treatment of sporadic inclusion-body myositis
Sporadic inclusion-body myositis (s-IBM) is a chronic progressive inflammatory myopathy leading to severe disability. It has been suggested that statins may benefit s-IBM patients based on their pleiotropic effects on autoimmunity and possible adverse influence of increased cholesterol on muscle pathological changes. We carried out a pilot, open-label trial to evaluate safety and tolerability of oral simvastatin in s-IBM patients. Fourteen patients were treated with 40 mg of simvastatin over 12 months. Primary outcome measures included the assessment tools proposed by International Myositis Outcome Assessment Collaborative Study group and the IBM-Functional Rating Scale. As additional data, we report the results obtained from muscle MRI, biopsy and oropharyngeal scintigraphy. Ten patients completed the trial and the treatment appeared safe and well tolerated. None of the patients showed a significant clinical improvement. Outcome measures used in this study proved to be valuable tools for global assessment of s-IBM patients. At present, we cannot recommend simvastatin as a treatment for s-IBM though our data may warrant a placebo-controlled study
Evidence for the involvement of gamma delta T cells in the immune response in Rasmussen encephalitis
Rasmussen encephalitis (RE) is a rare neuroinflammatory disease characterized by intractable seizures and progressive atrophy on one side of the cerebrum. Perivascular cuffing and clusters of T cells in the affected cortical hemisphere are indicative of an active cellular immune response. Methods: Peripheral blood mononuclear cells (PBMCs) and brain-infiltrating lymphocytes (BILs) were isolated from 20 RE surgery specimens by standard methods, and CD3+ T cell populations were analyzed by flow cytometry. Gamma delta T cell receptor spectratyping was carried out by nested PCR of reversed transcribed RNA extracted from RE brain tissue, followed by high resolution capillary electrophoresis. A MiSeq DNA sequencing platform was used to sequence the third complementarity determining region (CDR3) of δ1 chains. Results: CD3+ BILs from all of the RE brain specimens comprised both aαβ and γδ T cells. The median aαβ:γδ ratio was 1.9 (range 0.58-5.2) compared with a median ratio of 7.7 (range 2.7-40.8) in peripheral blood from the same patients. The aαβ T cells isolated from brain tissue were predominantly CD8+, and the majority of γδ T cells were CD4- CD8-. Staining for the early activation marker CD69 showed that a fraction of the aαβ and γδ T cells in the BILs were activated (median 42 %; range 13-91 %, and median 47 %; range 14-99 %, respectively). Spectratyping T cell receptor (TCR) Vδ1-3 chains from 14 of the RE brain tissue specimens indicated that the γδ T cell repertoire was relatively restricted. Sequencing δ1 chain PCR fragments revealed that the same prevalent CDR3 sequences were found in all of the brain specimens. These CDR3 sequences were also detected in brain tissue from 15 focal cortical dysplasia (FCD) cases. Conclusion: Neuroinflammation in RE involves both activated aαβ and γδ T cells. The presence of γδ T cells with identical TCR δ1 chain CDR3 sequences in all of the brain specimens examined suggests that a non-major histocompatibility complex (MHC)-restricted immune response to the same antigen(s) is involved in the etiology of RE. The presence of the same δ1 clones in CD brain implies the involvement of a common inflammatory pathway in both diseases
Requirement of translocated lysosomal V1 H+-ATPase for activation of membrane acid sphingomyelinase and raft clustering in coronary endothelial cells
The activation of translocated lysosomal H+-ATPase is attributed to FasL-induced formation and maintenance of an acid microenvironment around the endothelial cell membrane, which facilitates the activation of ASM and production of ceramide, thereby leading to MR clustering and redox signaling platform formation