Classification criteria for Sjogren's syndrome (SS) were developed and validated between 1989 and 1996 by the European Study Group on Classification Criteria for SS, and broadly accepted. These have been re-examined by consensus group members, who have introduced some modifications, more clearly defined the rules for classifying patients with primary or secondary SS, and provided more precise exclusion criteria.

https://ard.bmj.com/content/annrheumdis/61/6/554.full.pdf

Classification criteria for Sjögren's syndrome: a revised version of the European criteria proposed by the American-European Consensus Group

Laboratory Features Elevation of sarcoplasmic enzymes in serum (creatine phosphokinase, aldolase, transaminases and lactic dehydrogenase) is valuable both for diagnosis and for following the clinic...

Polymyositis and dermatomyositis (first of two parts)

Retrospective study: The diagnostic accuracy of conventional forceps biopsy of gastric epithelial compared to endoscopic submucosal dissection (STROBE compliant).

Mammalian skeletal muscle comprises different fiber types, whose identity is first established during embryonic development by intrinsic myogenic control mechanisms and is later modulated by neural and hormonal factors. The relative proportion of the different fiber types varies strikingly between species, and in humans shows significant variability between individuals. Myosin heavy chain isoforms, whose complete inventory and expression pattern are now available, provide a useful marker for fiber types, both for the four major forms present in trunk and limb muscles and the minor forms present in head and neck muscles. However, muscle fiber diversity involves all functional muscle cell compartments, including membrane excitation, excitation-contraction coupling, contractile machinery, cytoskeleton scaffold, and energy supply systems. Variations within each compartment are limited by the need of matching fiber type properties between different compartments. Nerve activity is a major control mechanism of the fiber type profile, and multiple signaling pathways are implicated in activity-dependent changes of muscle fibers. The characterization of these pathways is raising increasing interest in clinical medicine, given the potentially beneficial effects of muscle fiber type switching in the prevention and treatment of metabolic diseases.

Fiber types in mammalian skeletal muscles.

/pdf/polymyositis-and-dermatomyositis-second-of-two-parts-4t4ldab41i.pdf

Polymyositis and dermatomyositis (second of two parts).

Metabolic profiles of three fiber types of skeletal muscle in guinea pigs and rabbits.

Computer-assisted analysis of 153 patients with polymyositis and dermatomyositis.

BARNARD, R. JAMES, V. REGGIE EDGERTON, TETSUO FURUKAWA, AND J. B. PETER. Histochemical, biochemical, and contractile properties of red, white, and intermediate jibers. Am. J. Physiol. 220 (2) : 41 O-41 4. 197 1 .-Individual fibers from guinea pig muscles (soleus, flexor hallucis longus (FHL), flexor digitorium longus (FDL), medial gastrocnemius (MG) and the portion of the vastus lateralis (RV) which is grossly red) were classified as “red,” “white,” or “intermediate” according to their histochemical activity of NADHdiaphorase and myosin ATPase. Actomyosin and myosin ATPase activities of these muscles were determined biochemically and contraction times were measured in situ. The data demonstrate that in guinea pigs the soleus, which is composed entirely of intermediate fibers, is a slow-twitch muscle and has the lowest myosin and actomyosin ATPase activities. Conversely, muscles composed predominately of white fibers (FHL and FDL) or predominately of red fibers (MG and RV) are both fast-twitch muscles and have higher ATPase activities. Since both the soleus and RV are red in appearance the generalization that red muscles have slow contraction times is not valid. We suggest that these fibers be referred to as fast-twitch red, fast-twitch white, and slow-twitch intermediate.

James B. Peter

Papers

Polymyositis and dermatomyositis (first of two parts)

Polymyositis and dermatomyositis (second of two parts).

Metabolic profiles of three fiber types of skeletal muscle in guinea pigs and rabbits.

Computer-assisted analysis of 153 patients with polymyositis and dermatomyositis.

Histochemical, biochemical, and contractile properties of red, white, and intermediate fibers