The application of intravenous, intrathecal, and inhalation enhancement techniques to the CT evaluation of the nonhuman primate (Papio cynocephalus/anubis) is described. The falx cerebri cortical vasculature, vein of Galen, straight sinus and tentorium cerebelli were defined with intravenous enhancement. Intrathecal CT enhancement with air was limited by distortion in cerebrospinal fluid spaces. Intrathecal CT enhancement using a low dose of metrizamide accurately delineated the subarachnoid spaces and the brain substance they surrounded with minimal morbidity. Symmetrical brain enhancement (perfusion) was prominent following inhalation CT enhancement; the degree of enhancement correlated with the estimated xenon concentration in the bloodstream. In addition, by performing repeated CT scans during the clearance of xenon from the brain, an approximate analysis of regional cerebral blood flow was obtained.

Animals↗

PubMedDate not supplied

Dobesilate diminishes activation of the mitogen-activated protein kinase ERK1/2 in glioma cells.

Fibroblast growth factors (FGFs) and their receptors, regularly expressed at high levels in gliomas, are further upregulated during the transition of the tumor from low- to high-grade malignancy, and are essential for glioma progression. FGFs induce upregulation of the mitogen-activated protein kinase (MAPK) signaling cascade in cultured glioma cells, which suggests that MAPK pathway participates in the FGF-dependent glioma development. Recently, it has been shown that dobesilate, an inhibitor of FGF mitogenic activity, shows antiproliferative and proapoptotic activities in glioma cell cultures. Accordingly, it should be expected this new synthetic FGF inhibitor to affect the activation levels of MAPK. Here we report that immunocytochemical and Western blot data unequivocally show that treatment of cell cultures with dobesilate causes a significant decrease of the intracellular levels of ERK1/2 activation, one of the components of the MAPK signalling cascade. This finding supports an important role for dobesilate in glioma growth, suggesting that dobesilate should be a treatment to be born in mind for glioma management.

Calcium Dobesilate↗

PubMedDate not supplied

Low molecular weight dextran in experimental embolectomy.

The canine middle cerebral artery (MCA) was embolized with a pliable cylinder 8 mm long by 1.6 mm in diameter via the internal carotid artery. Both control and experimental embolectomies were performed 6 hours following embolization. The experimental animals were treated with low molecular weight dextran (LMD). In the control animals, the average volume of infarction in the brain was 1.45 cm.3 In the experimental animals the average volume of infarction was 0.13 cm.3

Animals↗

PubMedDate not supplied

Selective lenticulostriate occlusion in the primate. A highly focal cerebral ischemia model.

A highly reliable model for the study of focal cerebral ischemia has been developed using a retro-orbital approach to occlude the lateral lenticulostriate arteries of the baboon. An infarction of the caudate, putamen and the anterior limb of the internal capsule has consistently been produced. Reliability has been attained because the anatomical variations of the lenticulostriate arteries of each animal can be fully appraised, permitting selective vessel occlusion. A well-defined clinical and radiographic lesion has also resulted from this procedure which was clinically well tolerated by all animals. Selective lenticulostriate occlusion provides a new approach to the study of focal cerebral ischemia in the sub-human primate, and serves for the evaluation of proposed therapies for treatment of focal cerebral ischemia.

Animals↗

PubMedDate not supplied

Acute canine cerebral ischemia: a preliminary model to evaluate microvascular mammary-carotid anastomosis.

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Acute Disease↗

PubMedDate not supplied

Evoked potential changes during brain retraction in dogs.

Brain retraction and induced hypotension are surgical adjuncts capable of compromising cerebral blood flow. To evaluate their effects upon brain function, cortical evoked potentials, neurological status and cortical histological changes were determined as a function of graded levels of brain retractor and systemic perfusion pressure in the dog. Somatosensory evoked potentials recorded from the site of application of brain retraction showed a decrement as a function of both the amount of retraction pressure and the systemic perfusion pressure. An electrode distant from the retractor site showed similar, though reduced and more variable changes in amplitude. For higher levels of brain retractor pressure, induced hypotension to 50 mm Hg systemic perfusion pressure produced greater reductions in evoked potentials than in normotensive subjects. It was demonstrated that a reduction of 50% of the evoked potential amplitude after sixty minutes brain retraction signaled, with high probability, the occurrence of postoperative sensory and/or motor deficits and cortical histopathology. It was concluded that cortical evoked potentials represent a reliable indicator of the functional effects produced by applied cortical retraction pressure at several levels of systemic perfusion pressure. It was suggested that the recording of evoked potentials would prove most useful during neurosurgical procedures employing induced hypotension and brain retraction.

Animals↗