The rates of acid production were compared in thin strips of muscle biopsy samples isolated from malignant hyperpyrexia and control vastus internus human muscle. Halothane doubled the rate of acid production by malignant hyperpyrexia susceptible muscle but had no effect on control samples. This increased rate of release of acid from muscle was not from lactate. In addition, the pyruvate dehydro...

BACKGROUND Studies on airway remodeling in children with cystic fibrosis (CF) may be hampered by difficulty in obtaining evaluable endobronchial biopsy specimens because of large amounts of mucus and inflammation in the CF airway. We prospectively assessed how the quality of biopsy specimens obtained from children with CF compare with those from children with other airway diseases. METHODS Fi...

Ten healthy sedentary subjects underwent 35-days bed rest (BR) and needle biopsy samples of the vastus lateralis muscle were collected pre-BR and post-BR. One portion of the biopsy was glycerinated and used to dissect individual muscle fibers, which were studied for measuring fiber size, myosin content and myosin actin ratio by quantitative electrophoresis. Another portion of the biopsy was imm...

BACKGROUND Clinically, it is difficult to differentiate multiple acyl-CoA dehydrogenase deficiency (MADD) from immune-mediated necrotizing myopathy (IMNM) because they display similar symptoms. This study aimed to determine whether muscle magnetic resonance imaging (MRI) could be used for differential diagnosis between MADD and IMNM. METHODS The study evaluated 25 MADD patients, confirmed by ...

BACKGROUND Eosinophilic granulomatosis with polyangiitis is a complex multisystemic syndrome with heterogeneous presentation. Most often, there is a clinical history of asthma or other atopic conditions, and current presentation generally includes signs of cutaneous or pulmonary involvement. Very few reports described myalgia or weakness as the chief complaint. Of these, only a few included mus...

We retrospectively reviewed 118 muscle biopsy specimens from 113 patients with clinical and/or biochemical evidence of mitochondrial cytopathy. Light microscopic evaluation revealed histologic abnormalities in 65 specimens. The most common histologic findings included angular atrophic esterase-positive muscle fibers, type II muscle atrophy, regenerating muscle fibers, and scattered cytochrome-o...

We describe a method for obtaining skeletal muscle and subcutaneous adipose tissue in a single percutaneous needle biopsy procedure. Biopsies were performed in a double-blind randomized, sham-exercise controlled clinical trial of power training in 103 older adults with type 2 diabetes. In total 110 biopsies (73.3%) were performed in the first 50 participants at 3 time points. Muscle samples wer...

BACKGROUND The clinical features of myositis related with Human T-cell leukemia virus type 1 (HTLV-1) remains unclear despite epidemiological studies suggesting inflammatory myopathy associated with the virus. CASE PRESENTATION Here, we described the clinical presentations, muscle biopsy studies and laboratory results of two siblings with HTLV-1-associated myelopathy / tropical spastic parapa...

IMPORTANCE Documentation of muscle pathology compatible with targeting of sarcolemmal aquaporin-4 (AQP4) by complement-activating IgG implies involvement of organs beyond the central nervous system in neuromyelitis optica spectrum disorders. OBSERVATIONS We report on a 51-year-old woman who had relapsing optic neuritis, transverse myelitis, AQP4-IgG seropositivity, and recurrent myalgias with...

Limb girdle muscular dystrophies are heterogeneous autosomal hereditary neuromuscular disorders. They produce dystrophic changes on muscle biopsy and they are associated with mutations in several genes involved in muscular structure and function. Detailed clinical, laboratorial, imaging, diagnostic flowchart, photographs, tables, and illustrated diagrams are presented for the differential diagn...