Satellite cell activity is differentially affected by contraction mode in human muscle following a work-matched bout of exercise
Optimal repair and adaptation of skeletal muscle is facilitated by resident stem cells (satellite cells). To understand how different exercise modes influence satellite cell dynamics, we measured satellite cell activity in conjunction with markers of muscle damage and inflammation in human skeletal muscle following a single work- and intensity-matched bout of eccentric (ECC) or concentric contractions (CON). Participants completed a single bout of ECC (n = 7) or CON (n = 7) of the knee extensors. A muscle biopsy was obtained before and 24 h after exercise. Functional measures and immunohistochemical analyses were used to determine the extent of muscle damage and indices of satellite cell activity. Cytokine concentrations were measured using a multiplexed magnetic bead assay. Isokinetic peak torque decreased following ECC (p < 0.05) but not CON. Greater histological staining of the damage marker Xin was observed in muscle samples of ECC vs. CON. Tenasin C immunoreactivity increased 15 fold (p < 0.01) following ECC and was unchanged following CON. The inflammatory cytokines interferon gamma-induced protein 10 (IP-10) and monocyte chemotactic protein 1 (MCP-1) increased pre- to post-ECC (4.26 Â± 1.4 vs. 10.49 Â± 5.8 pg/ml, and 3.06 Â± 0.7 vs. 6.25 Â± 4.6 pg/ml, respectively; p < 0.05). There was no change in any cytokine post-CON. Satellite cell content increased 27% pre- to post-ECC (0.10 Â± 0.031 vs. 0.127 Â± 0.041, respectively; p < 0.05). There was no change in satellite cell number in CON (0.099 Â± 0.027 vs. 0.102 Â± 0.029, respectively). There was no fiber type-specific satellite cell response following either exercise mode. ECC but not CON resulted in an increase in MyoD positive nuclei per myofiber pre- to post-exercise (p < 0.05), but there was no change in MyoD DNA binding activity in either condition. In conclusion, ECC but not CON results in functional and histological evidence of muscle damage that is accompanied by increased satellite cell activity 24 h post-exercise.
Carcinomatous meningitis from urachal carcinoma: the first reported case
Carcinomatous meningitis (CM) occurs in less than 10% of cancer patients. Although patients frequently present with a focal complaint, multifocal signs are often found following careful neurological examination. The gold standard for diagnosis remains the demonstration of neoplastic cells in the cerebrospinal fluid. Despite the discouraging prognosis, palliative treatment may improve quality of life and lengthen lifespan. We report a patient with known primary carcinoma of the urachus who presented with headaches, nausea, vomiting and ataxia 1 week following resection of a nodular arachnoidal metastasis (indenting the cerebellum). Lumbar cerebrospinal fluid subsequently confirmed carcinomatous meningitis. This is the first reported case of carcinomatous meningitis resulting from metastatic urachal carcinoma
Cerebellar pilocytic astrocytoma with auditory presentation: case study [Case Report]
An 8-year-old girl complained of decreased hearing and difficulty hearing from her right ear while on the telephone. Pure-tone and speech audiometry, immittance (tympanometry, acoustic reflex thresholds), auditory brainstem response, and transient click-evoked otoacoustic emissions were administered. The results were suggestive of a space-occupying lesion, and the patient was referred to a pediatric neurologist and neurosurgeon. A cerebellar pilocytic astrocytoma was found. The patient's audiologic profile is described, along with implications for pediatric neurologic evaluations.
Surgical management of dissociated motor loss following complex cervical spine reconstruction [Case Report]
STUDY DESIGN/METHODS:A case of surgical management of dissociated motor loss after decompression of the cervical spine is reported. OBJECTIVES/OBJECTIVE:To present a rationale for surgical treatment of postdecompressive cervical radiculopathy with an illustrative case example. SUMMARY OF BACKGROUND DATA/BACKGROUND:The unusual complication of radiculopathy after multilevel cervical decompressive procedures is characterized by pain or dissociated motor weakness of the C5 and C6 nerve roots. Conservative management paradigms, including analgesics and steroids, are the rule, but symptoms often persist for many months. There are currently no reports describing foraminotomy as a means of more rapidly alleviating the symptoms of radicular pain and deltoid and biceps brachii weakness seen in the postoperative setting. METHODS:We present a case of bilateral C5 and C6 radiculopathy following multilevel cervical decompression for cervical spondylotic myelopathy, which we treated with posterior foraminotomies. RESULTS:The patient reported complete resolution of his dermatomal pain and demonstrated rapid improvement in upper extremity strength as compared to traditional conservative treatments. The historical experience and pathogenesis regarding this postoperative complication are reviewed. The rationale of root-specific posterior decompression for this debilitating complication is discussed. CONCLUSIONS:Foraminal decompression of the affected nerve roots as demonstrated here has not been described for postdecompressive dissociated motor loss. Such an approach may offer earlier and more complete relief to patients suffering from this unfortunate complication.