Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0033377 (prolapse)
 11,717 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The orbicularis oculi are the sphincter muscles of the eyelids and are involved in modulating facial expression. They differ from both limb and extraocular muscles (EOMs) in their histology and biochemistry. Weakness of the orbicularis oculi muscles is a feature of neuromuscular disorders affecting the neuromuscular junction, and weakness of facial muscles and ptosis have also been described in patients with mutations in the ryanodine receptor gene. Here, we investigate human orbicularis oculi muscles and find that they are functionally more similar to quadriceps than to EOMs in terms of excitation-contraction coupling components. In particular, they do not express the cardiac isoform of the dihydropyridine receptor, which we find to be highly expressed in EOMs where it is likely responsible for the large depolarization-induced calcium influx. We further show that human orbicularis oculi and EOMs express high levels of utrophin and low levels of dystrophin, whereas quadriceps express dystrophin and low levels of utrophin. The results of this study highlight the notion that myotubes obtained by explanting satellite cells from different muscles are not functionally identical and retain the physiological characteristics of their muscle of origin. Furthermore, our results indicate that sparing of facial and EOMs in patients with Duchenne muscular dystrophy is the result of the higher levels of utrophin expression.
 ...
PMID:Functional characterization of orbicularis oculi and extraocular muscles. 2706 19

Tolosa-Hunt syndrome is an uncommon disease that exhibits unilateral periorbital pain or headache, accompanied by cranial nerve palsies. Myasthenia gravis is an acquired immune system disease involving the neuromuscular junction. One rare case of Tolosa-Hunt syndrome combined with ocular myasthenia gravis had been reported in the literature, but not general myasthenia gravis. We present a patient with a probable coincidence of Tolosa-Hunt syndrome and general myasthenia gravis. A 63-year-old male exhibited episodes of unilateral headache with double vision, bilateral ptosis, vision decrease in the left eye and left facial hypoesthesia, muscle weakness in limbs and neck. The muscle weakness was fluctuating and could be relieved by rest. Blood analysis, cranial magnetic resonance imaging, magnetic resonance angiography/venogram) and orbit/mediastinum computed tomography demonstrated no abnormalities. Serum myasthenia gravis related antibodies detection showed positive titin- antibodies and ryanodine receptor antibodies. Corticosteroid and pyridostigmine bromide treatments were effective. Each of the patient's symptoms had almost disappeared at the third-month follow-up. We speculate on the etiology of Tolosa-Hunt syndrome with general myasthenia.
 ...
PMID:Tolosa-Hunt syndrome with general myasthenia gravis involvement. 3270