Skeletal muscles change length and develop force both passively and actively. Gearing allows muscle fiber length changes to be uncoupled from those of the whole muscle-tendon unit. During active contractions this process allows muscles to operate at mechanically favorable conditions for power or economical force production. Here we ask whether gearing is constant in passive muscle; determining ...

Neurogenic ATP and nitric oxide (NO) may play important roles in the physiological control of gastrointestinal motility. However, the interplay between purinergic and nitrergic neurons in mediating the inhibitory neurotransmission remains uncertain. This study investigated whether neurogenic NO modulates the purinergic transmission to circular smooth muscles of the hamster proximal colon. Elect...

LEARNING OBJECTIVES After reviewing the article, the participant should be able to: (1) Describe the anatomy of the extensor tendons at the level of the forearm, wrist, hand, and fingers. (2) Recognize variations in the anatomy. (3) Master the hand examination and define the relevant findings in acute injuries of the extensor tendon(s). (4) Delineate the techniques for extensor repair in both a...

This case report describes a young woman who presented with slowly progressing weakness of the proximal limb muscles and slight decrease of muscle tone but otherwise unremarkable neurological history. Diagnostic workup revealed fatty degeneration of the girdle muscles and an excessive increase of the parathyroid hormone as a result of severe vitamin D deficiency. Secondary hyperparathyroidism w...

This case report describes a young woman who presented with slowly progressing weakness of the proximal limb muscles and slight decrease of muscle tone but otherwise unremarkable neurological history. Diagnostic workup revealed fatty degeneration of the girdle muscles and an excessive increase of the parathyroid hormone as a result of severe vitamin D deficiency. Secondary hyperparathyroidism w...

Small-conductance Ca2+-activated K+ (SK) channels are important participants in inhibitory neurotransmission in gastrointestinal smooth muscles. Three isoforms of an SK channel family were cloned from murine proximal colon smooth muscle. The transcripts encoding these subunits (SK1, SK2, and SK3) were detected in murine proximal colon and other peripheral tissues. The mRNA of each subunit was e...

X-linked spinobulbar muscular atrophy (Kennedy's disease) affects muscles and motor neurons, manifesting as weakness and wasting of bulbar, facial, and proximal limb muscles due to loss of anterior horn cells in the brain and spinal cord. We present the case of a patient with X-linked spinobulbar muscular atrophy with rapidly worsening bulbar symptoms caused by laryngopharyngeal irritation asso...

Polyneuropathy is a rare but possible manifestation of severe hyperthyroidism. The patient reported here developed a polyneuropathy affecting mostly leg muscles (Basedow's paraplegia) during the course of severe thyrotoxicosis. The polyneuropathy was confirmed with sequential electrophysiological studies of nerves and muscles and by muscle biopsy. The involvement of the proximal leg muscle is a...

Hirayama's disease is a rare clinical variant of amyotrophic lateral sclerosis where distal muscles are involved more compared to proximal muscles and vice-versa occurs only in 10% cases and so it is differentiated from O'Sullivan McLeod syndrome which involves only small muscles of single limb. Here, we present a case of Hirayama's disease where disease achieved a plateau after 3 years with no...

This is a report of a 30-year-old male patient with a six-year history of chronic polymyositis. There was no family history of muscular or cardiac disease. Three years after the onset of the illness the patient developed congestive cardiac failure with evidence of complete heart block. Treatment with steroids failed to arrest the course of the disease. Necropsy showed abnormalities in the proxi...