Mutant KIT as imatinib-sensitive target in metastatic sinonasal carcinoma.

Background: Sinonasal carcinomas (SNCs) comprise various rare tumor types that are characterized by marked histologic diversity and largely unknown molecular profiles, yet share an overall poor prognosis owing to an aggressive clinical course and frequent late-stage diagnosis. The lack of effective systemic therapies for locally advanced or metastatic SNC poses a major challenge to therapeutic decision making for individual patients. We here aimed to identify actionable genetic alterations in a patient with metastatic SNC whose tumor, despite all diagnostic efforts, could not be assigned to any known SNC category and was refractory to multimodal therapy. Patients and methods: We used whole-exome and transcriptome sequencing to identify a KIT exon 11 mutation (c.1733_1735del, p.D579del) as potentially druggable target in this patient and carried out cancer hotspot panel sequencing to detect secondary resistance-conferring mutations in KIT. Furthermore, as a step towards clinical exploitation of the recently described signatures of mutational processes in cancer genomes, we established and applied a novel bioinformatics algorithm that enables supervised analysis of the mutational catalogs of individual tumors. Results: Molecularly guided treatment with imatinib in analogy to the management of gastrointestinal stromal tumor (GIST) resulted in a dramatic and durable response with remission of nearly all tumor manifestations, indicating a dominant driver function of mutant KIT in this tumor. KIT dependency was further validated by a secondary KIT exon 17 mutation (c.2459_2462delATTCinsG, p.D820_S821delinsG) that was detected upon tumor progression after 10 months of imatinib treatment and provided a rationale for salvage therapy with regorafenib, which has activity against KIT exon 11/17 mutant GIST. Conclusions: These observations highlight the potential of unbiased genomic profiling for uncovering the vulnerabilities of individual malignancies, particularly in rare and unclassifiable tumors, and underscore that KIT exon 11 mutations represent tractable therapeutic targets across different histologies.

Glibenclamide reduces secondary brain damage after experimental traumatic brain injury.

Following traumatic brain injury (TBI) SUR1-regulated NCCa-ATP (SUR1/TRPM4) channels are transcriptionally up-regulated in ischemic astrocytes, neurons, and capillaries. ATP depletion results in depolarization and opening of the channel leading to cytotoxic edema. Glibenclamide is an inhibitor of SUR-1 and, thus, might prevent cytotoxic edema and secondary brain damage following TBI. Anesthetized adult Sprague-Dawley rats underwent parietal craniotomy and were subjected to controlled cortical impact injury (CCI). Glibenclamide was administered as a bolus injection 15min after CCI injury and continuously via osmotic pumps throughout 7days. In an acute trial (180min) mean arterial blood pressure, heart rate, intracranial pressure, encephalographic activity, and cerebral metabolism were monitored. Brain water content was assessed gravimetrically 24h after CCI injury and contusion volumes were measured by MRI scanning technique at 8h, 24h, 72h, and 7d post injury. Throughout the entire time of observation neurological function was quantified using the "beam-walking" test. Glibenclamide-treated animals showed a significant reduction in the development of brain tissue water content(80.47%±0.37% (glibenclamide) vs. 80.83%±0.44% (control); p<0.05; n=14). Contusion sizes increased continuously within 72h following CCI injury, but glibenclamide-treated animals had significantly smaller volumes at any time-points, like 172.53±38.74mm(3) (glibenclamide) vs. 299.20±64.02mm(3) (control) (p<0.01; n=10; 24h) or 211.10±41.03mm(3) (glibenclamide) vs. 309.76±19.45mm(3) (control) (p<0.05; n=10; 72h), respectively. An effect on acute parameters, however, could not be detected, most likely because of the up-regulation of the channel within 3-6h after injury. Furthermore, there was no significant effect on motor function assessed by the beam-walking test throughout 7days. In accordance to these results and the available literature, glibenclamide seems to have promising potency in the treatment of TBI.

Depression of neuronal activity by sedatives is associated with adverse effects after brain injury.

Analgesics and sedatives are frequently used in the treatment of acute brain injury and subsequent brain swelling. Most agents act on specific receptors to modulate neuronal activity, which is normally involved in feedback loops that direct system building and maintenance. We investigated the neurodegenerative effects of midazolam and isoflurane in a rat model of controlled cortical impact injury (CCII). Two hours prior to CCII, four experimental groups were treated with different agents including a minimum alveolar concentration (MAC 1.0) of isoflurane. For additional sedation, isoflurane MAC 1.67, midazolam alone, or midazolam in combination with flumazenil was used. Blood pressure and blood gas analysis were monitored to investigate systemic side effects. Two days after treatment, relative apoptotic cell counts were determined by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. With isoflurane and midazolam, electroencephalographic (EEG) recordings revealed a decrease in amplitude size and altered frequency distribution. Treatment using deep sedation with isoflurane MAC 1.67 or midazolam increased relative apoptotic cell count by 14.8% (95% CI 3.6 to 26.1, p<0.01) and 18.0% (95% CI 6.8 to 29.3, p<0.01), respectively. Co-treatment with flumazenil reversed the neurodegenerative effect of midazolam by -13.2% (95% CI -24.5 to -2.0, p<0.05). Functional neurological outcome was worse after isoflurane MAC 1.67 (18.8 score points; p<0.01) and midazolam (21.4 score points, p<0.001). Flumazenil antagonized the neurodegenerative effects of midazolam. In conclusion, neuronal survival and functional recovery are reduced by sedative use in a rat model of acute brain injury.

Electro-optical properties of nano-thickness polymer film.

We report the electro-optical (E/O) characteristics of the Langmuir-Blodgett film of poly(vinylidene fluoride with trifluoroethylene) copolymers. The structural origin of E/O response of nano LB films was discussed with the result of temperature dependent E/O response at a temperature range from 20 to 100 degrees C. Thermal hysteresis of E/O response and the ferroelectric-paraelectric phase transition were observed at a 20 monomolecular layers Langmuir-Blodgett films.

Influence of isoflurane on neuronal death and outcome in a rat model of traumatic brain injury.

In the developing brain agents clinically used for the purpose of analgosedation can cause severe neurodegeneration. In patients with TBI analgosedation is a first-line treatment for intracranial hypertension. At the same time, damaged neuronal networks undergo conformational changes and use developmental mechanisms to restore brain function. Inhibition of repair mechanisms by sedatives may cause brain dysfunction and neuronal cell death during development and after traumatic brain injury. To test this hypothesis, the influence of sedation was experimentally evaluated in a controlled cortical impact injury model (CCII). One experimental group was preconditioned with regular sedation (isoflurane 1.0 MAC(50)) and the second group with deep sedation (isoflurane 1.67 MAC(50)). After controlled cortical impact injury (CCII) we tested the outcome at 4 h and 48 h using histological methods and a neurological test. Increased apoptosis was found in referenced cortical areas as early as 48 h after trauma (TUNEL-positive cells/field of view, mean ± SEM, 116.6 ± 9.3 and 45.3 ± 4.1, both n = 12). Along with histological findings neurological outcome was worst as indicated by a higher score in the experimental group with deep sedation (mean ± SEM 4 h, 13.9 ± 0.6, n = 14 and 20 ± 0.7, n = 15; 48 h, 8.1 ± 0.6, n = 14 and 13.3 ± 0.6, n = 15). Although blood pressure was lower with deep sedation, no frank hypotension occurred. In our experiments deep sedation with high doses of isoflurane caused neurodegeneration and worse outcome compared with regular sedation.

Diagnostic markers for glioblastoma.

Glioblastoma (GBM) is the most malignant form of cerebral gliomas, and despite distinct progress in surgical resection, radiation and chemotherapy, the prognosis of patients with GBM is still very poor. In the past decades knowledge of genomics and proteomics and of diagnostic, prognostic, predictive and pharmakodynamic markers measured in cerebrospinal-fluid (CSF), serum, or tumor tissue biomarkers has improved. This review briefly compiles our concepts on diagnostic markers for GBM, focusing on the latest developments.

Nitric oxide synthase inhibitors and cerebral vasospasm.

L-arginine is a source of nitric oxide (NO) that is cleaved from the terminal guanidino nitrogen atom by nitric oxide synthase (NOS). NO evokes, because of its free radical properties and affinity to heme, ferrous iron and cysteine, a wide spectrum of physiological and pathophysiological effects. For many years, different exogenous NOS inhibitors were used to elucidate the role of NOS and NO in health and disease. Later, endogenous NOS inhibitors, as asymmetric dimethylarginine (ADMA) were discovered. Endogenous inhibitors as ADMA are produced by post-translational methylation of L-arginine which is catalyzed by a family of protein N-methyltransferases (PRMT), using S-adenosylmethionine as a methyl group donor. ADMA is eliminated by dimethylarginine dimethylaminohydrolases (DDAH I or II). ADMA hydrolysis increases NOS activity and NO production. Furthermore, L-citrulline, a by-product of ADMA hydrolysis as well as of NO production by NOS, can in turn inhibit DDAH. Therefore, endogenous inhibition of NOS can be modified via different ways (1) changing the availability of L-arginine and/or of L-citrulline; (2) stimulating or inhibiting DDAH activity; (3) modifying methylation via regulating availability of adenosylmethionine; or (4) modifying PRMT activity. Research elucidating the role of NOS inhibitors in respect of delayed cerebral vasospasm after subarachnoid hemorrhage is summarized.

Hemangiopericytomas grade II are not benign tumors.

BACKGROUND: Hemangiopericytomas (HPs) of the central nervous system are rare tumors and afflicted with a high propensity of recurrences and metastases. Histopathologically, HPs correspond to differentiated (WHO grade II) and anaplastic (WHO grade III) tumors. With respect to the available literature and our own experiences, the aggressiveness, especially of differentiated grade II HPs, seems to be underestimated. METHODS: Thus, in this retrospective study, we describe tumor behavior and examined the effect of radio- and chemotherapy on tumor control with respect to the WHO classification of grade II and III neoplasms. This study consists of 15 patients with cerebral (n = 10) and spinal (n = 5) HPs. RESULTS: Seven HPs were histopathologically classified as grade II and eight as anaplastic grade III tumors. Complete surgical resection could be achieved in 60% of cerebral and in 25% of spinal HPs. In total, local recurrences occurred in 20% of patients within 17.3 months after the primary operation. Recurrences occurred both from differentiated (n = 1) and anaplastic (n = 2) neoplasms. Treatment comprised re-operation followed by radio- and chemotherapy. Pointing out the importance of the extent of surgical resection, in this study, we could not detect a single patient showing any recurrences or systemic metastases after complete surgical resection of grade II HPs. During primary diagnostics, four patients showed systemic metastases. Although these tumors could be controlled via surgery, systemic metastases appeared in further four patients within 60.4 months. Interestingly, two of them were classified as differentiated tumors (WHO grade II). To control tumor progress, radiotherapy seemed to be partially effective. On the other hand, however, chemotherapy did not show any effect on tumor control. With respect to these results, screening investigations seem to be indispensable and are highly recommended during primary diagnostics and after the appearance of recurrences or metastases, independent of the histopathological staging of the tumor. CONCLUSION: With respect to our results, radical surgical resection offers the best treatment option to control tumor progress. In case of subtotal resection or histopathologically diagnosed anaplasia (WHO III), radiotherapy seems to be indicated; however, chemotherapy did not show effectiveness to control tumor progress.

Serum GFAP is a diagnostic marker for glioblastoma multiforme.

A serum marker for malignant cerebral astrocytomas could improve both differential diagnosis and clinical management of brain tumour patients. To evaluate whether the serum concentration of glial fibrillary acidic protein (GFAP) may indicate glioblastoma multiforme (GBM) in patients with single supratentorial space-occupying lesions, we prospectively examined 50 consecutive patients with histologically proven GBM, World Health Organization (WHO) grade IV, 14 patients with anaplastic astrocytoma (WHO grade III), 4 patients with anaplastic oligodendroglioma, 13 patients with diffuse astrocytoma (WHO grade II), 17 patients with a single cerebral metastasis and 50 healthy controls. Serum was taken from the patients before tumour resection or stereotactic biopsy. Serum GFAP levels were determined using a commercially available ELISA test and were detectable in 40 out of the 50 GBM patients (median: 0.18 microg/l; range: 0-5.6 microg/l). The levels were significantly elevated compared with those of the non-GBM tumour patients and healthy controls (median: 0 mug/l; range: 0-0.024 microg/l; P < 0.0001, respectively). Non-GBM tumour patients and all healthy subjects showed zero serum GFAP levels. There was a significant correlation between tumour volume (Spearman Rho, CC = 0.47; 95% confidence interval, 0.2-0.67; P < 0.001), tumour necrosis volume (CC = 0.49; 95% confidence interval, 0.2-0.72; P = 0.004), the amount of necrotic GFAP positive cells (CC = 0.61; 95% confidence interval, 0.29-0.81; P = 0.007) and serum GFAP level among the GBM patients. A serum GFAP level of >0.05 microg/l was 76% sensitive and 100% specific for the diagnosis of GBM in patients with a single supratentorial mass lesion in this series. Therefore, it can be concluded that serum GFAP constitutes a diagnostic biomarker for GBM. Future studies should investigate whether serum GFAP could also be used to monitor therapeutic effects and whether it may have a prognostic value.

Molecular, biochemical and histochemical characterization of two acetylcholinesterase cDNAs from the German cockroach Blattella germanica.

Full length cDNAs encoding two acetylcholinesterases (AChEs; Bgace1 and Bgace2) were cloned and characterized from the German cockroach, Blattella germanica. Sequence analyses showed that both genes possess all the typical features of ace, and that Bgace1 is orthologous to the insect ace1 whereas Bgace2 is to the insect ace2. Transcript level of Bgace1 was significantly higher (c. 10 fold) than that of Bgace2 in all 11 tissues examined, suggesting that Bgace1 likely encodes a predominant AChE. Multiple AChE bands were identified by native polyacrylamide gel electrophoresis and isoelectricfocusing from various tissue preparations, among which ganglia produced distinct two major and two minor AChE bands, indicative of the presence of at least two active AChEs. B. germanica AChEs appeared to be mainly localized in the central nervous system as demonstrated by histochemical activity staining, together with quantitative analysis of Bgace transcripts. Fluorescence in situ hybridization of the 1st thoracic ganglion confirmed that Bgace1 is predominantly transcribed and further showed that its transcript is found in almost entire region of inter or motor neurones including the cell bodies and axonal/dendritic branches. Bgace2 transcript is found only in the subset of neurones, particularly in the cell body. In addition, certain neurones were observed to express Bgace1 only.

Xanthogranuloma of the sellar region.

The incidence of diagnosed xanthogranuloma of the sellar region is very low [1, 2, 5, 6]. We report about two cases 1) in a 57-year-old female and 2) in a 5-year-old boy. In both cases radiographic findings revealed an inhomogeneous, contrast enhancing sellar lesion. Histopathology showed the typical features of a xanthogranuloma of the sellar region with cholesterol clefts, lympho-plasmacellular infiltrates, marked hemosiderin deposits, multinucleated foreign body giant cells around cholesterol clefts, accumulation of macrophages and only small epithelial cell clusters [6]. As xanthogranuloma of the sellar region are rarely diagnosed we want to draw attention to this rather unusual diagnosis.

Analysis of surface second-harmonic generation by orientational distribution function in a chiral polymer film.

By adopting classical models of molecular chirality, contributions of the coupled-oscillator and helix natures to the chiral surface second-order susceptibilities are identified through introduction of a molecular orientational distribution. Experimentally, surface orientational distribution functions at interfaces of an isotropic chiral chitosan polymer film are determined from second harmonic generation measurement. The largest chiral component of surface nonlinear optical susceptibility is from the electric-magnetic coupling with dominant contribution from the helix nature of chitosan.

Clivus lymphoma.

Lymphoma as primary infiltration of the skull base, especially the clivus, is unusual and rare. However, increasing incidence of atypical lymphoma manifestations have been reported. As cranial base surgery becomes more common, it is important to be aware of lymphoma as a possible differential diagnosis of clivus lesions. This case presents a primary malignant lymphoma of the clivus, histologically confirmed after intra-operative MRI-guided transnasal-transsphenoidal biopsy.

Removal of cholesterol from Cheddar cheese by beta-cyclodextrin.

This study was carried out to determine the cholesterol removal rate and resulting changes in flavor, fatty acid and bitter amino acid production in reduced-cholesterol Cheddar cheese, made by cream separation followed by 10% beta-cyclodextrin (beta-CD) treatment. The cholesterol removal from the cheese was 92.1%. The production of short-chain free fatty acids (FFAs) increased the ripening time in control and cream-treated cheeses. The quantity of short-chain FFAs released between treatments during ripening was different, while not much difference was found in the production of neutral volatile compounds in the samples. Reduced-cholesterol cheese produced much higher levels of bitter amino acids than the control. In sensory analysis, the texture score of control Cheddar cheese increased significantly with ripening time; however, that of the cream treatment group decreased dramatically with ripening time. On the basis of our results, we conclude that the cheese made from beta-CD-treated cream had a higher rate of cholesterol removal and ripened rapidly.

Effect of endothelin-converting enzyme inhibitors on big endothelin-1 induced contraction in isolated rat basilar artery.

INTRODUCTION: The aim of this study was to investigate whether blocking functional endothelin-converting enzyme (ECE) activity may offer a new approach to inhibit the development of cerebral vasopasm after subarachnoid hemorrhage (SAH) by preventing transformation of big Endothelin-1 (big ET-1) to vasoactive Endothelin-1 (ET-1). METHODS: In vitro, the effect of potential ECE inhibitors was determined by measurement of isometric contractions, induced by big ET-1, in isolated rat basilar arteries. Endothelium intact (E+) and de-endothelialized (E-) segments were examined after pre-incubated with the putative ECE inhibitors: Phosphoramidon (10(-4) M), Captopril (10(-3) M and 10(-4) M) and [(22)D-Val] big ET-1 (16-38) (10(-5) M and 10(-6) M). RESULTS: Application of 10(-4) M Phosphoramidon resulted in a statistically significant decrease in big ET-1 induced contraction in endothelium intact (E+) and de-endothelialized (E-) segments; 10(-3) M Captopril in E- segments caused a statistically significant inhibitory effect; 10(-4) M and 10(-3) M Captopril in E+ segments showed no statistically significant effect; 10(-5) M and 10(-6) M [(22)D-Val] big ET-1 (16-38) in E- segments produced no statistically significant effect. The application of 10(-6) M [(22)D-Val] big ET-1 (16-38) in E+ segments caused increased contractions as shown by the shift to the left of the concentration-effect curve (CEC). CONCLUSION: The present study indicates the existence of functional ECE activity in rat basilar artery, which is different in the endothelium and the smooth muscle layer. This ECE-activity could be inhibited by Captopril and Phosporamidon, suggesting a potency for prevention and therapy of cerebral vasospasm. However, the structural analogue of big ET-1, [(22)D-Val] big ET-1 (16-38), was ineffective in reducing big ET-1 induced vasoconstriction and rather increased contraction in E+ vessels. Therefore further studies of the biochemical nature of the functional relevant cerebrovascular ECE activity are required for better understanding and development of other efficient ECE inhibitors.

Run-up of gamma-aminobutyric acid(C) responses in catfish retinal cone-horizontal cell axon-terminals is modulated by protein kinase A and C.

Using whole-cell voltage-clamp techniques, we investigated the protein kinase modulation of gamma-aminobutyric acid(C) (GABA(C))-activated currents relating to run-up regulation in dissociated cone-horizontal cell (HC) axon-terminals from catfish retina. GABA induced an inward chloride current in cells voltage-clamped at -70 mV. With repetitive applications of 10 microM GABA, the peaks of the GABA responses increased up to approximately 135% of the control responses during a period of 10 min. Intracellular application of forskolin, an adenylate cyclase activator, decreased the run-up of GABA(C) responses. H8 dihydrochloride, a cAMP inhibitor, enhanced this run-up to 190% of the control responses. 1-oleoyl-2-acetyl-sn-glycerol, a protein kinase C activator, accelerated the run-up of GABA(C) responses. GF 109203X, a PKC inhibitor, decreased the run-up. These results suggest that retinal GABA(C) responses in cone-HC axon-terminals are modulated by both protein kinase A and C.

The GABA(C) receptor is present in cone-horizontal cell axon terminals isolated from catfish retina.

Whole cell voltage-clamp recordings were performed on isolated terminals and somata from catfish retina to compare the distribution of excitatory and inhibitory receptors in both structures. Saturating concentrations of glutamate or kainate produced small currents in axon terminals, averaging less than 8% of the current evoked in the soma. In contrast, application of high concentrations of gamma-aminobutyric acid (GABA) produced approximately similar current amplitudes in both structures. Based on estimates of membrane surface area, GABA-induced current densities were around 0.05 pA/microm2 for both structures. The GABA-activated current in the axon terminal was not blocked by bicuculline or SR95531, but was completely inhibited by picrotoxin. Baclofen did not mimic the GABA effect, but trans-4-aminocrotonic acid (TACA, 300 microM) and muscimol (1 mM) elicited currents of 100 and 40 pA, respectively. These results suggest that the axon terminals of cone-horizontal cells possess GABA(C) receptors at a high density, do not possess GABA(A) or GABA(B) receptors, and have few glutamate receptors. The GABA(C) receptors could function as postsynaptic receptors in the inner plexiform layer or as autoreceptors.

Serial inhibitory synapses in retina.

Whole-cell voltage clamp in the retinal slice and intracellular current clamp in the intact retina were used to study inhibitory interactions in the inner plexiform layer. Picrotoxin or strychnine reduced inhibitory, light-evoked currents in a majority of ganglion cells. However, in nearly a third of the ganglion cells, each of these antagonists enhanced the inhibitory synaptic current. All inhibitory current was blocked by the addition of the other antagonist. This indicates a cross-inhibition between GABAergic and glycinergic feedforward pathways. Blocking of GABAARs with SR95531 shortened the time course of both excitatory and inhibitory synaptic currents in ganglion cells. Application of picrotoxin, which blocked both GABAARs and GABACRs, produced the opposite effect. Recordings in the intact retina indicated that the light responses of ON bipolar cells, sustained ON, and transient ON-OFF third-order neurons were all made more transient by SR95531 and made more sustained by picrotoxin. The data suggest that a GABAC feedback pathway to bipolar cells makes light responses more phasic and that this feedback is inhibited through a GABAAR pathway. Consequently, the balance between GABAAR and GABACR inhibition regulates the time course of inputs to ganglion cells.