Single-Cell Information Analysis Reveals That Skeletal Muscles Incorporate Cell-to-Cell Variability as Information Not Noise.

Cell-to-cell variability in signal transduction in biological systems is often considered noise. However, intercellular variation (i.e., cell-to-cell variability) has the potential to enable individual cells to encode different information. Here, we show that intercellular variation increases information transmission of skeletal muscle. We analyze the responses of multiple cultured myotubes or isolated skeletal muscle fibers as a multiple-cell channel composed of single-cell channels. We find that the multiple-cell channel, which incorporates intercellular variation as information, not noise, transmitted more information in the presence of intercellular variation than in the absence according to the "response diversity effect," increasing in the gradualness of dose response by summing the cell-to-cell variable dose responses. We quantify the information transmission of human facial muscle contraction during intraoperative neurophysiological monitoring and find that information transmission of muscle contraction is comparable to that of a multiple-cell channel. Thus, our data indicate that intercellular variation can increase the information capacity of tissues.

Endoscopic transmastoid posterior petrosal approach for locally aggressive tumors in the petrous part of the temporal bone involving the internal auditory canal, jugular foramen, and hypoglossal canal.

OBJECTIVE: The posterior petrosal approach is an established surgical method offering wide access to skull base lesions through mastoid air cells. The authors describe their experience with the endoscopic transmastoid "posterior petrosal" approach (EPPAP) for skull base tumors involving the internal auditory canal (IAC), jugular foramen, and hypoglossal canal. METHODS: The EPPAP was performed for 7 tumors (3 chordomas, 2 chondrosarcomas, 1 schwannoma, and 1 solitary fibrous tumor). All surgical procedures were performed under endoscopic visualization with mastoidectomy. The compact bone of the mastoid air cells and posterior surface of the petrous bone are carefully removed behind the semicircular canals. When removal of cancellous bone is extended superomedially through the infralabyrinthine space, the surgeon can expose the IAC and petrous portion of the internal carotid artery to reach the petrous apex (infralabyrinthine route). When removal of cancellous bone is extended inferomedially along the sigmoid sinus, the surgeon can safely reach the jugular foramen (transjugular route). Drilling of the inferior surface of petrous bone is extended further inferoposteriorly behind the jugular bulb to approach the hypoglossal canal and parapharyngeal space through the lateral aspect of the occipital condyle (infrajugular route). RESULTS: Of the 7 tumors, gross-total resection was achieved in 4 (57.1%), subtotal resection (> 95% removal) in 2 (28.6%), and partial resection (90% removal) in 1 (14.2%). Postoperatively, 2 of 3 patients with exudative otitis media showed improvement of hearing deterioration, as did 2 patients with tinnitus. Hypoglossal nerve palsy and swallowing difficulty were improved after surgery in 2 patients and 1 patient, respectively. In 1 patient with severe cranial nerve deficits before surgery, symptoms did not show any improvement. CONCLUSIONS: The authors present their preliminary experience with EPPAP for skull base tumors in the petrous part of the temporal bone and the lateral part of the occipital condyle involving the cranial nerves and internal carotid arteries. The microscope showed a higher-quality image and illumination in the low-power field. However, the endoscope could offer wider visualization of the surgical field and contribute to minimizing the size of the surgical pathways, necessity of brain retraction, and eventually the invasiveness of surgery. Thus, the EPPAP may be safe and effective for skull base tumors in the petrous region, achieving balance between the radicality and invasiveness of the skull base surgery.

A case of more than 20 years survival with glioblastoma, and development of cavernous angioma as a delayed complication of radiotherapy.

Glioblastoma (GBM) is the most common malignant CNS neoplasm, the prognosis of which remains poor even after multidisciplinary treatment. The 5-year overall survival rate of GBM is less than 10% and has remained unchanged for more than 50 years. Because GBM patients rarely survive over a decade, only very few cases of delayed complications caused by therapy have been reported. Here, we report the case of a 24-year-old man who is still alive 21 years after surgical resection and chemoradiotherapy for GBM. This patient developed a cavernous angioma 19 years after the initial surgery as a delayed complication of radiotherapy. The diagnosis of the initial tumor was confirmed by histopathological review, which indicated that the tumor had immunohistochemical and genetic profiles consistent with GBM. Long-term survival in the case of this GBM patient likely resulted from a combination of factors, including hypermethylation of the MGMT (O(6)-methyl guanine methyl transferase) CpG island, young age at diagnosis, good performance status, and complete surgical resection of the tumor. To the best of our knowledge, this case report describes one of the longest-surviving GBM patients and is the first on radiation-induced cavernous angioma in a GBM patient.