Correction to: Multiple receptor tyrosine kinases converge on microRNA-134 to control KRAS, STAT5B, and glioblastoma.

Following publication of the article, the author named as "B Dey", wished to point out that his full name is "Bijan K. Dey". This was not reflected in the typesetting of the article, and as a consequence the article is not visible on Pub Med when a search is conducted on his full name.

Modular peptide-functionalized gold nanorods for effective glioblastoma multicellular tumor spheroid targeting.

Glioblastoma multiforme (GBM) contains a population of tumor initiating stem-like cells, termed cancer stem cells (CSCs). These CSCs, which are resistant to chemo- and radiotherapy, are thought to persist after treatment and drive tumor recurrence. Thus, it is believed that the elimination of CSCs can lead to GBM remission. GBM CSCs express Nestin on their surface, and can be therefore targeted via this protein. Gold nanorods (AuNRs) functionalized with an engineered, modular peptide that recognizes Nestin (NesPEG-AuNRs) were used to target the models of solid tumors originated from human GBM CSC multicellular tumor spheroids (MCTS). In our study, we show that NesPEG-AuNRs have low cytotoxicity, are efficiently taken up by MCTS, and distribute uniformly throughout our tumor models, not only at the periphery as often seen in other nanoparticle systems. NesPEG-AuNR uptake by MCTS appears to be mediated by an energy/caveolae endocytic mechanism. Moreover, plasmon excitation of AuNRs in the near-infrared (NIR) region results in the production of localized heat. Consequently, NesPEG-AuNR cytotoxicity is only observed during NIR-irradiation in MCTS with a high intracellular AuNR content. The intracellular accumulation/diffusion of NesPEG-AuNRs and NIR-irradiation result in photothermally induced GBM CSC apoptosis and MCTS growth inhibition. In summary, these data suggest that the combination of the Nestin recognizing peptide with AuNRs contributes to better tumor accumulation/penetration, and thus in GBM CSC elimination. Moreover, due to the modularity of our peptide design, the Nestin-binding peptide sequence can be exchanged for peptides targeting other surface markers for the treatment of various types of tumors.

Multiple receptor tyrosine kinases converge on microRNA-134 to control KRAS, STAT5B, and glioblastoma.

Receptor tyrosine kinases (RTKs) are co-deregulated in a majority of glioblastoma (GBM), the most common and most deadly brain tumor. We show that the RTKs MET, EGFR, and PDGFR regulate microRNA-134 (miR-134) in GBM. We find that miR-134 is downregulated in human tumors and cancer stem cells and that its expression inversely correlates with the activation of MET, EGFR, and PDGFR. We demonstrate that miR-134 inhibits cancer cell and stem-cell proliferation, survival, and xenograft growth, as well as cancer stem-cell self-renewal and stemness. We identify KRAS and STAT5B as targets of miR-134, and establish molecular and functional links between RTKs, miR-134, KRAS/STAT5B and malignancy in vitro and in vivo. We show that miR-134 induction is required for the anti-tumor effects of RTK inhibitors. We also uncover the molecular pathways through which RTKs regulate miR-134 expression and demonstrate the involvement of MAPK signaling and the KLF4 transcription factor. We therefore identify miR-134 as a novel RTK-regulated tumor-suppressive hub that mediates RTK and RTK-inhibitor effects on GBM malignancy by controlling KRAS and STAT5B.

Distribution of CD133 reveals glioma stem cells self-renew through symmetric and asymmetric cell divisions.

Malignant gliomas contain a population of self-renewing tumorigenic stem-like cells; however, it remains unclear how these glioma stem cells (GSCs) self-renew or generate cellular diversity at the single-cell level. Asymmetric cell division is a proposed mechanism to maintain cancer stem cells, yet the modes of cell division that GSCs utilize remain undetermined. Here, we used single-cell analyses to evaluate the cell division behavior of GSCs. Lineage-tracing analysis revealed that the majority of GSCs were generated through expansive symmetric cell division and not through asymmetric cell division. The majority of differentiated progeny was generated through symmetric pro-commitment divisions under expansion conditions and in the absence of growth factors, occurred mainly through asymmetric cell divisions. Mitotic pair analysis detected asymmetric CD133 segregation and not any other GSC marker in a fraction of mitoses, some of which were associated with Numb asymmetry. Under growth factor withdrawal conditions, the proportion of asymmetric CD133 divisions increased, congruent with the increase in asymmetric cell divisions observed in the lineage-tracing studies. Using single-cell-based observation, we provide definitive evidence that GSCs are capable of different modes of cell division and that the generation of cellular diversity occurs mainly through symmetric cell division, not through asymmetric cell division.

Hypoxia promotes expansion of the CD133-positive glioma stem cells through activation of HIF-1alpha.

Hypoxia contributes to the progression of a variety of cancers by activating adaptive transcriptional programs that promote cell survival, motility and tumor angiogenesis. Although the importance of hypoxia and subsequent hypoxia-inducible factor-1alpha (HIF-1alpha) activation in tumor angiogenesis is well known, their role in the regulation of glioma-derived stem cells is unclear. In this study, we show that hypoxia (1% oxygen) promotes the self-renewal capacity of CD133-positive human glioma-derived cancer stem cells (CSCs). Propagation of the glioma-derived CSCs in a hypoxic environment also led to the expansion of cells bearing CXCR4 (CD184), CD44(low) and A2B5 surface markers. The enhanced self-renewal activity of the CD133-positive CSCs in hypoxia was preceded by upregulation of HIF-1alpha. Knockdown of HIF-1alpha abrogated the hypoxia-mediated CD133-positive CSC expansion. Inhibition of the phosphatidylinositol 3-kinase(PI3K)-Akt or ERK1/2 pathway reduced the hypoxia-driven CD133 expansion, suggesting that these signaling cascades may modulate the hypoxic response. Finally, CSCs propagated at hypoxia robustly retained the undifferentiated phenotype, whereas CSCs cultured at normoxia did not. These results suggest that response to hypoxia by CSCs involves the activation of HIF-1alpha to enhance the self-renewal activity of CD133-positive cells and to inhibit the induction of CSC differentiation. This study illustrates the importance of the tumor microenvironment in determining cellular behavior.

Image-guided, direct convective delivery of glucocerebrosidase for neuronopathic Gaucher disease.

OBJECTIVE: To determine if convection-enhanced delivery (CED) of glucocerebrosidase could be used to treat targeted sites of disease progression in the brain and brainstem of a patient with neuronopathic Gaucher disease while monitoring enzyme distribution using MRI. METHODS: A CED paradigm in rodents (n = 8) and primates (n = 5) that employs co-infusion of a surrogate MRI tracer (gadolinium diethylenetriamine penta-acetic acid [Gd-DTPA]) with glucocerebrosidase to permit real-time monitoring of distribution was developed. The safety and feasibility of this delivery and monitoring paradigm were evaluated in a patient with type 2 Gaucher disease. RESULTS: Animal studies revealed that real-time, T1-weighted, MRI of Gd-DTPA accurately tracked enzyme distribution during CED. Targeted perfusion of clinically affected anatomic sites in a patient with neuronopathic Gaucher disease (frontal lobe and brainstem) with glucocerebrosidase was successfully performed. Real-time MRI revealed progressive and complete filling of the targeted region with enzyme and Gd-DTPA infusate. The patient tolerated the infusions without evidence of toxicity. CONCLUSIONS: Convection-enhanced delivery can be used to safely perfuse large regions of the brain and brainstem with therapeutic levels of glucocerebrosidase. Co-infused imaging surrogate tracers can be used to monitor and control the distribution of therapeutic agents in vivo. Patients with neuronopathic Gaucher disease and other intrinsic CNS disorders may benefit from a similar treatment paradigm.

Proteomic profiling distinguishes astrocytomas and identifies differential tumor markers.

Methods to permit more precise delineation of astrocytomas of different grades may have therapeutic utility. The authors selectively microdissected pure populations of cells from normal brain and astrocytomas. They performed two-dimensional protein gel electrophoresis (2DGE) followed by protein sequencing. Differential expression was confirmed immunohistochemically. 2DGE identified proteomic patterns and proteins that differentiated normal brain from tumor and distinguished astrocytomas of increasing grade.

C-fos expression in rat brain nuclei following incisor tooth movement.

In the rat experimental model, molar tooth movement induced by Waldo's method is known to cause a temporally and spatially defined pattern of brain neuronal activation. Since orthodontic correction usually involves the entire dental arch, we used a spring-activated appliance to extend the investigation to incisors, and we included brain regions related to antinociception. Adjustment of the non-activated appliance on incisors resulted in c-fos expression in the dorsal raphe, peri-aqueductal gray matter, and the locus coeruleus, in addition to trigeminal sensory subnuclei and the parabrachial nucleus, where neuronal activation has already been detected in previous studies on molar tooth movement. Appliance activation with a 70-g force resulted in a further increase in Fos-immunoreactive neurons in the trigeminal sensory subnucleus caudalis and in the dorsal raphe. This result suggests that there is a recruitment of neurons related to nociception and to antinociception when tooth movement is increased.

Direct muscle neurotization in rat soleus muscle.

An experimental study was conducted using rat soleus muscles to characterize reinnervation of the denervated muscles by direct muscle neurotization. Also studied was whether there is any difference in the regeneration process between original (tibial) and foreign (peroneal) nerve neurotization. For functional evaluation, an electrophysiologic study was carried out by analyzing pattern, latency, amplitude, and duration of compound motor action potential. In a histochemical study, both hematoxylin-eosin stain and nicotineamide adenin dehydrogenase stain were used to identify the morphology and the change in the type of muscle fiber. Combined silver-acetylcholinesterase stain was utilized to identify reinnervated motor endplates and axonal sprouting. Evidence of regeneration of the denervated muscle by direct muscle neurotization could be confirmed. Regenerating muscles showed type grouping of muscle fibers. The newly-formed ectopic motor endplate was connected with axonal sprouting. The giant motor endplate composed of mature axon sprouting and several new ectopic motor endplates appeared in the neurotization group. There was no specific difference in the regeneration process between original and foreign nerve neurotization.

Direct muscle neurotization in rat soleus muscle.

The authors carried out an experimental study using rat soleus muscles to evaluate reinnervation of the denervated muscles by direct muscle neurotization. They also attempted to determine whether there is any difference in the regeneration process between original (tibial) and foreign (peroneal) nerve neurotization. For functional evaluation, they did an electrophysiologic study by analyzing pattern, latency, amplitude, and duration of compound motor action potential. For histochemical studies, both hematoxyline-eosin stain and nicotineamide adenin dehydrogenase stainings were used to identify the morphology and the change of the type of muscle fiber. Combined silver-acetylcholinesterase stain was performed to identify reinnervated motor endplate and axonal sprouting. They confirmed evidence of regeneration of the denervated muscle by direct muscle neurotization. Regenerating muscles showed type groupings of muscle fibers. The newly-formed ectopic motor endplate was connected with axonal sprouting. The giant motor endplate composed of mature axon sprouting and several new ectopic motor endplates, appeared in the neurotization group. There was no significant difference in the regeneration process between original and foreign nerve neurotization.

Lamotrigine monotherapy in newly diagnosed untreated epilepsy: a double-blind comparison with phenytoin.

PURPOSE: Lamotrigine is an effective add-on therapy against a range of epileptic seizure types. Comparative studies with carbamazepine (CBZ) as monotherapy in newly diagnosed epilepsy suggest similar efficacy. In this study, lamotrigine (LTG) and phenytoin (PHT) are compared. METHODS: In a double-blind parallel-groups study, 181 patients with newly diagnosed untreated partial seizures or secondarily or primary generalised tonic-clonic seizures were randomised to two treatment groups. One group (n = 86) received LTG titrated over 6 weeks from a starting dose of 100 mg/day. The other (n = 95) received PHT titrated from 200 mg/day. Treatment continued for < or =48 weeks. RESULTS: The percentages of patients remaining on each treatment and seizure free during the last 24 and 40 weeks of the study, and times to first seizure after the first 6 weeks of treatment (dose-titration period), did not differ significantly between the treatment groups. These were measures of efficacy. Time to discontinuation, a composite index of efficacy and safety, likewise did not distinguish between treatments. Adverse events led to discontinuation of 13 (15%) patients from LTG and 18 (19%) from PHT. The adverse-event profile for LTG was dominated by skin rash [discontinuation of 10 (11.6%) patients compared with five (5.3%) from PHT] rather than central nervous system side effects: asthenia, somnolence, and ataxia were each significantly more frequent in the PHT group. The high rate of rash with LTG was probably due to the high starting dose and may be avoidable. A quality-of-life instrument, the SEALS inventory, favoured LTG. Patients taking PHT showed the biochemical changes expected of an enzyme-inducing drug, whereas those taking LTG did not. CONCLUSIONS: LTG and PHT monotherapy were similarly effective against these seizure types in patients with newly diagnosed epilepsy. LTG was better tolerated, more frequently causing rash, but with a lower incidence of central nervous system side effects.

How do patients want physicians to handle mistakes? A survey of internal medicine patients in an academic setting.

BACKGROUND: Mistakes are an inevitable part of the practice of medicine. While the frequency and severity of medical errors are documented, little is known about patients' attitudes toward physician mistakes. OBJECTIVE: To examine patient attitudes about physician errors. DESIGN: A survey instrument assessed attitudes to 3 levels of physician mistakes (minor, moderate, and severe) and 2 fundamental physician responses: disclosure or nondisclosure. One hundred forty-nine study subjects were randomly selected from an academic general internal medicine outpatient clinic. RESULTS: Virtually all patients (98%) desired some acknowledgment of even minor errors. Patient's desire for referral to another physician ranged from 14% following a minor mistake to 65% following a severe mistake. For both moderate and severe mistakes, patients were significantly more likely to consider litigation if the physician did not disclose the error. In the moderate mistake scenario, 12% of patients would sue if informed by the physician vs 20% if the physician failed to disclose the error and they discovered it by some other means (P < .001). CONCLUSIONS: Patients desire an acknowledgment from their physicians of even minor errors, and doing so may actually reduce the risk of punitive actions. These findings reinforce the importance of open communication between patients and physicians.

Botulinum toxin--a possible new treatment for axillary hyperhidrosis.

The inhibitory action of botulinum toxin is not limited to the neuromuscular junction. The toxin also blocks the autonomic cholinergic fibres, including the sympathetic fibres to sweat glands. We have previously demonstrated that the toxin produces localized anhidrosis. To determine the dosage, pattern and duration of the anhidrotic effect of botulinum toxin and to test the efficacy of axillary injections, we further studied seven healthy volunteers. Two individuals had subcutaneous injections of botulinum toxin (20 mouse units, Dysport-Porton Products) in the dorsum of the hand. Five healthy volunteers had 15-50U of botulinum toxin A (Botox) injected in one axilla. A circular area of complete anhidrosis on the dorsum of the hand was evident on day 2 and persisted for 11 months. By day 3, two of the axillae (injected with 50 U each) were totally dry and in one (injected with 30 U) the sweating was substantially reduced. The effect persisted for 6-8 months before wearing off. No effect was appreciated in two axillae (injected with 15 and 20 U). No significant side-effects were encountered. Subcutaneous injections of botulinum toxin causes chemodenervation of the sweat glands. In normal individuals axillary sweating can be abolished by 50 U of botulinum toxin A (Botox). The results offer a possible novel treatment for severe cases of axillary hyperhidrosis.

Scales for rating motor impairment in Parkinson's disease: studies of reliability and convergent validity.

Study 1 examined the reliability of the ratings assigned to the performance of five sign-and-symptom items drawn from tests of motor impairment in Parkinson's disease. Patients with Parkinson's disease of varying severity performed gait, rising from chair, and hand function items. Video recordings of these performances were rated by a large sample of experienced and inexperienced neurologists and by psychology undergraduates, using a four point scale. Inter-rater reliability was moderately high, being higher for gait than hand function items. Clinical experience proved to have no systematic effect on ratings or their reliability. The idiosyncrasy of particular performances was a major source of unreliable ratings. Study 2 examined the intercorrelation of several standard rating scales, comprised of sign-and-symptom items as well as activities of daily living. The correlation between scales was high, ranging from 0.70 to 0.83, despite considerable differences in item composition. Inter-item correlations showed that the internal cohesion of the tests was high, especially for the self-care scale. Regression analysis showed that the relationship between the scales could be efficiently captured by a small selection of test items, allowing the construction of a much briefer test.

Botulinum toxin in treating spasticity.

The value of locally injected botulinum toxin is emphasised. The toxin was injected directly into the skeletal muscles of eight patients with severe spasticity due to stroke-related hemiplegia. It produced both subjective and objective improvement. The toxin injections were well tolerated and no significant side effects were noted.

Effect of treatment with botulinum toxin on spasticity.

Botulinum toxin, a product of Clostridium botulinum, produces presynaptic neuromuscular block by preventing release of acetylcholine from nerve endings. The toxin was injected directly into the skeletal muscles of six patients with severe spasticity due to stroke-related hemiplegia. It produced both subjective and objective improvement. The toxin injections were well tolerated and no significant side effect was reported.

EEG characteristics of epileptic pattern sensitivity and their relation to the nature of pattern stimulation and the effects of sodium valproate.

Seven patients with pattern-sensitive epilepsy were examined repeatedly over a period of 4-12 months during which the dose of sodium valproate was adjusted. Patterns were presented in series in which the size of successive patterns was progressively increased until paroxysmal activity appeared, or until the largest pattern (radius 24 degrees visual angle) had been presented. As valproate dose increased, paroxysmal activity was less likely to occur. When it did occur it was less likely to include a spike; it had a lower voltage, involved fewer electrodes, and lasted a shorter time. The size of the pattern just sufficient to induce paroxysmal activity showed relatively little change with valproate dose. The degree to which the various electrodes were involved in the discharges showed considerable stability. The paroxysmal response to patterns presented in one visual half-field was almost invariably maximal over the contralateral posterior quadrant, usually at the posterior temporal electrode.