Confocal Laser and Electron Microscopic Investigation of Gap Junctions in Anaplastic Astrocytomas.

Connexin 43 (Cx43) is a multifunction protein that forms gap junction channels and hemichannels and is suggested to play an essential role in oxygen-glucose deprivation, induced via neuroinflammation during astrocytoma expansion into healthy tissue. To prove this assumption we studied connexin 43 localisation and ultrastructure of gap junctions in samples of malignant brain tumour (anaplastic astrocytomas grade III). For confocal laser microscopy, vibratome sections of tumour fragments were incubated in a mixture of primary antibodies to connexin 43 and glial fibrillary acidic protein (GFAP), then in a mixture of secondary antibodies conjugated with a fluorescent label. After the immunofluorescence study, sections were washed in phosphate buffer, additionally postfixed with 1% OsO4 solution, dehydrated and embedded in epoxy resin by a plane-parallel method. Ultra-thin sections obtained from these samples were contrasted with uranyl acetate and lead citrate and viewed under a Jem 1011 electron microscope. Confocal laser examination detected a positive reaction to Cx43 in the form of point fluorescence. These points were of various sizes. Most of them were localised around or at the intersection of small processes containing GFAP. Electron microscopy of the tumour samples containing the most significant number of Cx43 revealed single and closely spaced gap junctions with a typical ultrastructure on the processes and bodies of tumour cells. Sequential analysis in the fields of view revealed 62 gap junctions in the area of 100 µm2. Numerous gap junctions in anaplastic astrocytomas revealed in our study may indicate electrotonic and metabolic transmission between glioma cells, possibly promoting its progression.

How I do it: decompressive hemicraniectomy supplemented with resection of the temporal pole and tentoriotomy for malignant ischemic infarction in the territory supplied by the middle cerebral artery.

Malignant ischemic infarction in the territory supplied by the middle cerebral artery is an extremely severe form of ischemic stroke associated with development of massive uncontrollable postischemic edema of the affected cerebral hemisphere; the end result of which is development of transtentorial herniation and death. METHOD: The surgical technique of performance of decompressive hemicraniectomy involves removal of an extensive bone flap in the fronto-temporo-parieto-occipital zone with resection of the temporal squama and of the greater wing of the sphenoid bone to visualize the level of entrance of the middle meningeal artery to the cranial cavity, which, in its turn, allows resection of the upright margin of the middle cranial fossa. Decompressive hemicraniectomy is supplemented with resection of the temporal pole and tentoriotomy. CONCLUSION: Performance of decompressive hemicraniectomy in combination with resection of the resection of the temporal pole and tentoriotomy is an effective surgical method of treatment of malignant ischemic stroke in the territory supplied by the middle cerebral artery, capable of reducing the lethality rate during the postoperative period.