Learn More
Because complex structural differences in adult extraocular muscles may have physiological and pathophysiological significance, the three-dimensional pattern of myosin heavy chain (MHC) isoform expression within the orbital and global layers of the muscle bellies compared with the distal tendon ends was quantitatively assessed. Three of the six extraocular(More)
Fiber type shifts in aging skeletal muscle have been studied with myofibrillar ATPase histochemistry and gel electrophoresis, but less commonly with immunohistochemistry. Immunohistochemical study of myosin heavy chains (MHCs) in single myofibers yields additional information about aged skeletal muscle. Furthermore, many studies of aging rodent skeletal(More)
PURPOSE Mammalian extraocular muscles (EOMs) are both physiologically and biochemically unique when compared with nonocular skeletal muscles. Recent studies have demonstrated a process of continuous myonuclear addition in normal uninjured myofibers in adult EOMs of rabbits and mice. The current study was conducted to determine whether this process of(More)
Many neuromuscular diseases are characterized by involuntary and forceful muscle contraction. Doxorubicin has been shown to chemically remove the orbicularis oculi muscle after injection into the eyelid. The chemomyectomy effect of doxorubicin was quantified after injection of a 2-mg dose into the right lower eyelid. A significant loss of muscle was seen in(More)
PURPOSE Botulinum toxin type A and, more recently, the immunotoxin ricin-mAb35 have been effective as means of pharmacologically weakening the extraocular muscle. However, currently there are no drug treatments to strengthen an underacting extraocular muscle. In limb muscle, treatment with insulin-like growth factor causes myofiber hypertrophy. In this(More)
PURPOSE This study examined the subacute myotoxic effects of injection of the local anesthetic bupivacaine on the orbicularis oculi muscle in the rabbit eyelid. In contrast to other muscles, the orbicularis oculi was resistant to injury by the usual anesthetic doses of bupivacaine when local infiltration is used. An attempt was made to assess the(More)
The orbicularis oculi muscle is a complex facial muscle involved in eyelid closure. The central parts of pretarsal and preseptal regions of the palpebral part of the orbicularis oculi muscle in rabbit and cynomolgus monkey lower eyelids were examined histologically and were analyzed for muscle fiber number, muscle fiber cross-sectional area and fiber type(More)
PURPOSE Extraocular muscles express a number of characteristics not normally seen in mature skeletal muscle. The expression of neural cell adhesion molecule, N-CAM, was assessed immunohistochemically in the extraocular muscles of rabbits, monkeys, and humans to examine the hypothesis that there is greater complexity to extraocular muscle fiber types than(More)
The optic nerve of the developing rat was examined for the presence of laminin, an adhesive glycoprotein, to assess whether it might serve as a substrate for retinal axon growth in vivo. The optic stalk and nerve of developing rats were screened immunohistochemically for the presence of laminin before, during, and after the period of retinal axon growth. On(More)
PURPOSE Doxorubicin is effective in permanently removing muscle after direct injection into the eyelid for treatment of blepharospasm and hemifacial spasm. However, patients often require two or more injection series before full abatement of their spasms is achieved. Local anesthetics cause muscle necrosis, followed by regeneration, a process that requires(More)