Randomized prospective trial of fractionated stereotactic radiosurgery with chemotherapy versus chemotherapy alone for bevacizumab-resistant high-grade glioma

Journal of Neuro-Oncology - Outcomes for patients with recurrent high-grade glioma (HGG) progressing on bevacizumab (BEV) are dismal. Fractionated stereotactic radiosurgery (FSRS) has been shown to...     

Bridge method of skin-flap delay.

Necrosis, a catastrophic complication of skin-falp use, is due to inadequate capillary blood flow. Delay procedures, which are based on newer information regarding skin vasculature and delay dynamics, can augment surviving-flap length. A delay procedure that used multiple skin bridges was studied in 121 flaps in 21 pigs. The result was a considerably greater amount of length augmentation than has previously been reported. This enhanced effect is related to a combination of nearly maximal sympathectomy in a highly ischemic, surgically defined experimental flap.     

Empathic accuracy and cognition in schizotypal personality disorder

Interpersonal dysfunction contributes to significant disability in the schizophrenia spectrum. Schizotypal Personality Disorder (SPD) is a schizophrenia-related personality demonstrating social cognitive impairment in the absence of frank psychosis. Past research indicates that cognitive dysfunction or schizotypy may account for social cognitive dysfunction in this population. We tested SPD subjects and healthy controls on the Empathic Accuracy (EA) paradigm and the Reading of the Mind in the Eyes Test (RMET), assessing the impact of EA on social support. We also explored whether EA differences could be explained by intelligence, working memory, trait empathy, or attachment avoidance. SPD subjects did not differ from controls in RMET, but demonstrated lower EA during negative valence videos, associated with lower social support. Dynamic, multimodal EA paradigms may be more effective at capturing interpersonal dysfunction than static image tasks such as RMET. Schizotypal severity, trait empathy, and cognitive dysfunction did not account for empathic dysfunction in SPD, although attachment avoidance is related to empathic differences. Empathic dysfunction for negative affect contributes to decreased social support in the schizophrenia spectrum. Future research may shed further light on potential links between attachment avoidance, empathic dysfunction, and social support.     

Neural stem cells spontaneously express dopaminergic traits after transplantation into the intact or 6-hydroxydopamine-lesioned rat

The ability to differentiate neural stem cells (NSCs) into dopamine neurons is fundamental to their role in cell replacement therapies for neurodegenerative disorders such as Parkinson's disease. We show here that when a clonal line (C17.2) of undifferentiated NSCs is transplanted into the intact or 6-hydroxydopamine-lesioned striatum, cells withdraw from the cell cycle (BrdU(-)), migrate extensively in the host striatum, and express markers associated with neuronal (beta-tubulin III(+), NSE(+), NeuN(+)) but not glial (GFAP(-), MBP(-), A2B5(-)) differentiation. Importantly, by 2-5 weeks postgrafting, in the majority of these transplants, nearly all engrafted cells express the dopamine-synthesizing enzymes tyrosine hydroxylase and aromatic L-amino decarboxylase, sometimes resulting in changes in motor behavior. In contrast, no NSCs stain for dopamine-beta-hydroxylase, choline acetyltransferase, glutamic acid decarboxylase, or serotonin. We conclude that, following transplantation into the intact or 6-hydroxydopamine-lesioned rat, the adult brain contains intrinsic cues sufficient to direct the specific expression of dopaminergic traits in immature multipotential neural stem cells.     

Pharmacologic profile of chemically stable analogs of peptide leukotrienes

Peptide leukotrienes are potent constrictors of airway smooth muscle but lack chemical stability. Replacement of the natural triene backbone of leukotrienes with 9-(x-heptylphenyl)-7-nonenoic acid (x = 2, 3, or 4) renders these analogs chemically stable and pharmacologically active. The para, meta and ortho substitutions of the heptyl (C7H15) moiety were combined with the different leukotriene peptide substitutions of glutathionyl, C-peptide of leukotriene C4, cysteinylglycinyl, D-peptide of leukotriene D4, and cysteinyl, E-peptide of leukotriene E4 rendering nine active analogs. The pharmacology of these analogs was evaluated in isolated guinea-pig tracheal strips. The para-substituted C-peptide analog was the most potent; however, it was 100-fold less potent than leukotriene C4. The contractile activities of the para- and meta-substituted C-peptide analogs were enhanced by L-serine borate (45 mM), indicating they were substrates for gamma-glutamyl transpeptidase. FPL55712 (10 microM) failed to antagonize the substituted C-peptide analogs independent of the presence of L-serine borate. The contractile activities of the three substituted D-peptide analogs were enhanced by L-cysteine, indicating they are all substrates for aminopeptidase. The para-substituted D-peptide analog was the most potent D-peptide analog, but it was 10- and 1,000-fold less active than the para-substituted C-peptide analog and leukotriene D4, respectively. The para- and meta-substituted E-peptide analogs were approximately 1,000-fold less potent than leukotriene E4, and like the substituted D-peptide analogs, they were antagonized by FPL55712. In contrast, the ortho-substituted E-peptide analog was devoid of intrinsic activity but antagonized leukotriene E4-induced contractions.(ABSTRACT TRUNCATED AT 250 WORDS)     

General anesthetics selectively modulate glutamatergic and dopaminergic signaling via site-specific phosphorylation in vivo

Isoflurane, propofol and ketamine are representative general anesthetics with distinct molecular mechanisms of action that have neuroprotective properties in models of excitotoxic ischemic damage. We characterized the effects of these agents on neuronal glutamate and dopamine signaling by profiling drug-induced changes in brain intracellular protein phosphorylation in vivo to test the hypothesis that they affect common downstream effectors. Anesthetic-treated and control mice were killed instantly by focused microwave irradiation, frontal cortex and striatum were removed, and the phosphorylation profile of specific neuronal signaling proteins was analyzed by immunoblotting with a panel of phospho-specific antibodies. At anesthetic doses that produced loss of righting reflex, isoflurane, propofol, and ketamine all reduced phosphorylation of the activating residue T183 of ERK2 (but not of ERK1); S897 of the NR1 NMDA receptor subunit; and S831 (but not S845) of the GluR1 AMPA receptor subunit in cerebral cortex. At sub-anesthetic doses, these drugs only reduced phosphorylation of ERK2. Isoflurane and ketamine also reduced phosphorylation of spinophilin at S94, but oppositely regulated phosphorylation of presynaptic (tyrosine hydroxylase) and postsynaptic (DARPP-32) markers of dopaminergic neurotransmission in striatum. These data reveal both shared and agent-specific actions of CNS depressant drugs on critical intracellular protein phosphorylation signaling pathways that integrate multiple second messenger systems. Reduced phosphorylation of ionotropic glutamate receptors by all three anesthetics indicates depression of normal glutamatergic synaptic transmission and reduced potential excitotoxicity. This novel approach indicates a role for phosphorylation-mediated down-regulation of glutamatergic synaptic transmission by general anesthetics and identifies specific in vivo targets for focused evaluation of anesthetic mechanisms.     

Validity of optical pachometry measurements made with contact lenses in situ

Traditionally changes in corneal thickness associated with contact lens wear have been measured with optical pachometers after the lenses are removed from the cornea. In studies of corneal response to the extended wearing of hydrogel and silicone elastomer contact lenses, optical pachometry measurements may be improved by uninterrupted lens wear during the measurements. Using four flexible lens types differing in design and thickness, a single observer made pachometric measurements both with and without the lenses in place on eight subjects. This study demonstrates that valid and reliable measures of corneal thickness may be made without removing flexible lenses from the eye.     

Do periodic hyperinflations improve gas exchange in patients with hypoxemic respiratory failure?

Prolonged artificial ventilation may result in worsening gas exchange and pulmonary compliance in patients with otherwise normal lungs. Prolonged hyperinflations to 40 cm H2O can completely reverse deterioration of gas exchange and compliance in such patients. Similar efforts have effectively recruited atelectatic lung regions in critically ill patients. Less aggressive hyperinflations have not improved lung function in patients with abnormal lungs with hypoxemia. However, sustained exaggerated hyperinflations may successfully open collapsed lung units in these patients when standard recruitment techniques fail. We compared periodic hyperinflations of 40 cm H2O lasting 15 to 30 sec associated with body positioning (directed recruitment [DR]) to standard bag-sigh-suctioning (BSS) for their effects on gas exchange and pulmonary compliance in 16 stable surgical ICU patients with hypoxemic respiratory failure of 24-h duration or longer. Patients were sequentially alternated between DR and BSS (group 1, BSS followed by DR; group 2, DR followed by BSS). Neither technique, alone or in sequence, resulted in a sustained (greater than or equal to 5 min) improvement or deterioration in either gas exchange or pulmonary compliance. We conclude that neither BSS nor DR reliably affects gas exchange or compliance in patients with established hypoxemic respiratory failure.