Radiomic biomarkers informative of cancerous transformation in neurofibromatosis-1 plexiform tumors.

BACKGROUND: This study explores whether objective, quantitative radiomic biomarkers derived from magnetic resonance (MR), positron emission tomography (PET), and computed tomography (CT) may be useful in reliably distinguishing malignant peripheral nerve sheath tumors (MPNST) from benign plexiform neurofibromas (PN). METHODS: A registration and segmentation pipeline was established using a cohort of NF1 patients with histopathological diagnosis of PN or MPNST, and medical imaging of the PN including MR and PET-CT. The corrected MR datasets were registered to the corresponding PET-CT via landmark-based registration. PET standard-uptake value (SUV) thresholds were used to guide segmentation of volumes of interest: MPNST-associated PET-hot regions (SUV≥3.5) and PN-associated PET-elevated regions (2.0

Neuronal Ceroid Lipofuscinosis Type 6 (CLN6) clinical findings and molecular diagnosis: Costa Rica's experience.

BACKGROUND: Commonly known as Batten disease, the neuronal ceroid lipofuscinoses (NCLs) are a genetically heterogeneous group of rare pediatric lysosomal storage disorders characterized by the intracellular accumulation of autofluorescent material (known as lipofuscin), progressive neurodegeneration, and neurological symptoms. In 2002, a disease-causing NCL mutation in the CLN6 gene was identified (c.214G > T) in the Costa Rican population, but the frequency of this mutation among local Batten disease patients remains incompletely characterized, as do clinical and demographic attributes for this rare patient population. OBJECTIVE: To describe the main sociodemographic and clinical characteristics of patients with a clinical diagnosis for Batten Disease treated at the National Children's Hospital in Costa Rica and to characterize via molecular testing their causative mutations. METHODS: DNA extracted from buccal swabs was used for CLN6 gene sequencing. Participants' sociodemographic and clinical characteristics were also obtained from their medical records. RESULTS: Nine patients with a clinical diagnosis of Batten disease were identified. Genetic sequencing determined the presence of the previously described Costa Rican homozygous mutation in 8 of 9 cases. One patient did not have mutations in the CLN6 gene. In all cases where the Costa Rican CLN6 mutation was present, it was accompanied by a substitution in intron 2. Patients were born in 4 of the 7 Costa Rican provinces, with an average onset of symptoms close to 4 years of age. No parental consanguinity was present in pedigrees. Initial clinical manifestations varied between patients but generally included: gait disturbances, language problems, visual impairment, seizures and psychomotor regression. Cortical and cerebellar atrophy was a constant finding when neuroimaging was performed. Seizure medication was a common element of treatment regimens. CONCLUSIONS: This investigation supports that the previously characterized c.214G > T mutation is the most common causative NCL mutation in the Costa Rican population. This mutation is geographically widespread among Costa Rican NCL patients and yields a clinical presentation similar to that observed for CLN6 NCL patients in other geographies.

A comparative assessment of the effects of integrin inhibitor cilengitide on primary culture of head and neck squamous cell carcinoma (HNSCC) and HNSCC cell lines.

BACKGROUND: Integrins are highly attractive targets in oncology due to their involvement in angiogenesis in a wide spectrum of cancer entities. Among several integrin inhibitors, cilengitide is suggested to be one of the most promising inhibitors. However, little is known about the cellular processes induced during cilengitide chemotherapy in head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: For the current study, 3 HNSCC cell lines, SCC4, SCC15 and SCC25; and 3 primary culture cells, TU53, TU57, and TU63 were used. CD90, cytokeratin, and vimentin were stained immunohistochemically to identify the biological characteristics of these cell lines and primary culture cells and the cytostatic effect of cilengitide was evaluated. Quantitative polymerase chain reaction (qPCR) arrays were applied to evaluate target protein genes ITGAV, ITGB3, and ITGB5 of integrin αvß3 and αvß5 at respective concentrations of 50 and 100 µM cilengitide for 72 h. RESULTS: Cilengitide has significantly inhibited the proliferation of HNSCC cells in a dose-dependent way. At the same concentration, cilengitide suppressed the proliferation of primary culture cells even more strongly than it did that of cell lines, suggesting that primary culture cells retain more of their internal biological characteristics than do cell lines. qPCR assay detected downregulation of ITGAV, ITGB3, and ITGB5 gene expression after exposure to 50 µM of cilengitide. However, after exposure to 100-µM cilengitide, expression of these genes significantly increased both in cell lines and primary culture cells. CONCLUSIONS: RGD-containing small-molecule synthetic peptides might be considered in tumor chemotherapy in the near future. The different reactions of primary culture cells and cell lines demonstrated that individualized chemotherapy plans may be a feasible option. However, research on the role of cilengitide in HNSCC therapy is still in its early stages, and further investigations are required.

MARCKS Is Necessary for Netrin-DCC Signaling and Corpus Callosum Formation.

Axons of the corpus callosum (CC), the white matter tract that connects the left and right hemispheres of the brain, receive instruction from a number of chemoattractant and chemorepulsant cues during their initial navigation towards and across the midline. While it has long been known that the CC is malformed in the absence of Myristoylated alanine-rich C-kinase substrate (MARCKS), evidence for a direct role of MARCKS in axon navigation has been lacking. Here, we show that MARCKS is necessary for Netrin-1 (NTN1) signaling through the DCC receptor, which is critical for axon guidance decisions. Marcks null (Marcks-/-) neurons fail to respond to exogenous NTN1 and are deficient in markers of DCC activation. Without MARCKS, the subcellular distributions of two critical mediators of NTN1-DCC signaling, the tyrosine kinases PTK2 and SRC, are disrupted. Together, this work establishes a novel role for MARCKS in axon dynamics and highlights the necessity of MARCKS as an organizer of DCC signaling at the membrane.

MARCKS regulates neuritogenesis and interacts with a CDC42 signaling network.

Through the process of neuronal differentiation, newly born neurons change from simple, spherical cells to complex, sprawling cells with many highly branched processes. One of the first stages in this process is neurite initiation, wherein cytoskeletal modifications facilitate membrane protrusion and extension from the cell body. Hundreds of actin modulators and microtubule-binding proteins are known to be involved in this process, but relatively little is known about how upstream regulators bring these complex networks together at discrete locations to produce neurites. Here, we show that Myristoylated alanine-rich C kinase substrate (MARCKS) participates in this process. Marcks-/- cortical neurons extend fewer neurites and have less complex neurite arborization patterns. We use an in vitro proteomics screen to identify MARCKS interactors in developing neurites and characterize an interaction between MARCKS and a CDC42-centered network. While the presence of MARCKS does not affect whole brain levels of activated or total CDC42, we propose that MARCKS is uniquely positioned to regulate CDC42 localization and interactions within specialized cellular compartments, such as nascent neurites.

Acute Cytotoxic and Vasogenic Edema after Subarachnoid Hemorrhage: A Quantitative MRI Study.

BACKGROUND AND PURPOSE: The mechanism of early brain injury following subarachnoid hemorrhage is not well understood. We aimed to evaluate if cytotoxic and vasogenic edema are contributing factors. MATERIALS AND METHODS: A retrospective analysis was conducted in patients with SAH undergoing diffusion-weighted MR imaging within 72 hours of onset. Apparent diffusion coefficient values derived from DWI were evaluated by using whole-brain histograms and 19 prespecified ROIs in patients with SAH and controls with normal findings on MRI. Cytotoxic edema observed outside the ROIs was assessed in patients with SAH. The average median ADC values were compared between patients with SAH and controls and patients with SAH with mild (Hunt and Hess 1-3) versus severe early brain injury (Hunt and Hess 4-5). RESULTS: We enrolled 33 patients with SAH and 66 controls. The overall average median whole-brain ADC was greater for patients with SAH (808 × 10-6 mm2/s) compared with controls (788 × 10-6 mm2/s, P < .001) and was higher in patients with SAH across ROIs after adjusting for age: cerebral gray matter (826 versus 803 × 10-6 mm2/s, P = .059), cerebral white matter (793 versus 758 × 10-6 mm2/s, P = .023), white matter tracts (797 versus 739 × 10-6 mm2/s, P < .001), and deep gray matter (754 versus 713 × 10-6 mm2/s, P = .016). ADC values trended higher in patients with Hunt and Hess 4-5 versus those with Hunt and Hess 1-3. Early cytotoxic edema was observed in 13 (39%) patients with SAH and was more prevalent in those with severe early brain injury (87.5% of patients with Hunt and Hess 4-5 versus 24.0% of those with Hunt and Hess 1-3, P = .001). CONCLUSIONS: Age-adjusted ADC values were globally increased in patients with SAH compared with controls, even in normal-appearing brain regions, suggesting diffuse vasogenic edema. Cytotoxic edema was also present in patients with SAH and correlated with more severe early brain injury.

Proof of partial imbalances 6q and 11q due to maternal complex balanced translocation analyzed by microdissection of multicolor labeled chromosomes (FISH-MD) in a patient with Dandy-Walker variant.

We report on a family in which a daughter is described with mental retardation, as well as malformations of the heart, and of the brain (Dandy-Walker variant). The patient's phenotype suggests a chromosomal rearrangement. However, her karyotype was unremarkable by conventional cytogenetic analysis. In order to detect chromosome rearrangements overseen by this method, the subtelomere regions of suspicious chromosomes were verified by fluorescence in situ hybridization (FISH). A rearranged derivative chromosome 6 was identified. Further examinations by FISH-microdissection (FISH-MD) revealed a maternal complex balanced translocation. The patient inherited the derivative chromosome 6 from her mother and therefore carries a partial monosomy 6q26-->qter and a partial trisomy 11q23.3-->qter.

Delineation of a complex karyotypic rearrangement by microdissection and CGH in a family affected with split foot.

We report on a male patient and members of his family with additional material in chromosome 3. This derivative chromosome 3 was transmitted from his mother who had a complex rearrangement between chromosomes 2, 3, and 7. It was possible to delineate her chromosomal rearrangement by microdissection and reverse painting and to exclude these aberrations from being responsible for neonatal deaths and several abortions in this family. Two members of this family suffer from ectrodactyly or split hand/foot malformations (SHFM) of the feet which possibly correlates with the derivative chromosome 7 containing a breakpoint in the SHFM1 critical region involving several homeobox genes.

Clathrin assembly protein AP-2 is detected in both neurons and glia, and its reduction is prominent in layer II of frontal cortex in Alzheimer's disease.

There are several adaptor proteins associated with clathrin coated vesicles. Among them are AP180 and AP-2. We and others have previously described synaptic localization of AP180. AP180 immunoreactivity is altered in both the superior frontal gyrus and hippocampus in Alzheimer's disease (AD). We here investigate the location and alteration of another adaptor protein, AP-2. In contrast to AP180, we have found that AP-2 is expressed by both neurons and glia. Furthermore, the only noticeable change of AP-2 in AD is a loss of its immunoreactivity in layer II of the superior frontal gyrus.

The effect of nitrogen diffusion hardening on the surface chemistry and scratch resistance of Ti-6A1-4V alloy.

Modular, head-stem, mixed-metal connections are susceptible to mechanically mediated electrochemical interactions. Any attempt to improve the performance of these connections should center around increasing their resistance to mechanical damage, particularly the titanium alloy (Ti64). This study investigated the effect of a nitrogen-diffusion-hardening process on Ti64, with specific reference to changes in composition, chemistry, electrochemistry and its ability to resist and/or repassivate scratch damage. The nitrogen-diffusion-hardened Ti64 alloy had TiN and TiNO complexes at the immediate surface and sub-surface layers. The diffusion-hardened samples also had a deeper penetration of oxygen compared to regular Ti64 alloy samples. The electrochemical impedance spectroscopy data corroborated the increased thickness of the barrier oxide on the diffusion-hardened samples. The nitrogen-diffusion-hardened samples were more resistant to scratch damage and repaired/repassivated faster after such damage. The results suggest that the nitrogen-diffusion-hardened titanium alloy should exhibit increased resistance to mechanical-electrochemical interactions in mixed-metal modular interfaces in total hip prostheses.

Surface topography, corrosion and microhardness of nitrogen-diffusion-hardened titanium alloy.

Mechanical-electrochemical interactions accelerate corrosion in mixed-metal modular hip prostheses. These interactions can be reduced by improving the modular component machining tolerances or by improving the resistance of the components to scratch or fretting damage. Wrought cobalt-alloy (CoCrMo) is known to have better tribological properties compared to the titanium alloy (Ti64). Thus, improving the tribological properties of this mixed-metal interface should center around improving the tribological properties of the Ti64 alloy. This study used scanning probe microscopy (contact, tapping and phase contrast mode), scanning electron microscopy, corrosion testing, and microhardness testing to determine the effect of a nitrogen-diffusion hardening process on the surface morphology, electrochemistry and surface hardness of the Ti64 alloy. The nitrogen-diffusion-hardened titanium alloy samples (N-Ti64) had a more pronounced grain structure, more nodular surface, and significantly (P<0.01) higher mean roughness values than the control-Ti64 samples. The N-Ti64 samples also exhibited at least equivalent corrosion behavior and a definite increase in surface hardness compared to the control Ti64 samples. The equivalent corrosion behavior and improved surface hardness indicate the potential for N-Ti64 samples to resist similar and mixed-metal scratch and fretting damage. The use of N-Ti64 as opposed to control-Ti64 may therefore reduce the occurrence of mechanical-electrochemical degradation in mixed-metal modular total hip prostheses.

Comparison of comparative genomic hybridization and interphase fluorescence in situ hybridization in ovarian carcinomas: possibilities and limitations of both techniques.

Comparative genomic hybridization (CGH) is a valuable technique for cytogenetic analysis of solid tumors. To evaluate the reliability of CGH, we examined DNA of 10 ovarian carcinomas after CGH analysis with single- and double-locus fluorescence in situ hybridization (FISH). The FISH experiments, involving 5 chromosomes (chromosomes 3, 6, 8, 12, and 18) with different FISH probes, confirmed the CGH results in 66.2% of cases (92 of 139 investigated loci). In 4 patients, inconsistent results (41 loci) were related to polyploidy, because CGH cannot detect polyploid karyotypes. The remaining 6 discordant loci can be referred to limitations in both techniques. Re-evaluation of FISH and CGH results by one other is therefore recommended to overcome these technical artifacts. Nevertheless, CGH is of potential value in characterizing chromosomal alterations and might help in generating tumor-specific sets of FISH probes to obtain genetic information of prognostic value within a few days.

Surface characterization of titanium-based implant materials.

This study examined the effects of different treatments (polished, electropolished, and grit-blasted) on the surface morphology and chemistry of commercially pure titanium and titanium-6% aluminum-4% vanadium. The structure and composition of the surfaces were evaluated using scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy, Auger microprobe analysis, and x-ray photoelectron spectroscopy. Surface roughness values at large scales were nearly identical for grit-blasted and electropolished samples, while at smaller scales, electropolished and polished samples had nearly identical quantitative roughness values. The surface oxide compositions were found to be primarily titanium dioxide on both materials for all surface treatments. No vanadium was seen with either x-ray photoelectron spectroscopy or Auger microprobe analysis for the alloy, indicating a possible surface depletion. Calcium was present on the grit-blasted samples, and calcium and chlorine were detected on the electropolished samples.

Cleaning and heat-treatment effects on unalloyed titanium implant surfaces.

This study tested the following hypotheses: (1) acid-cleaned and passivated unalloyed titanium implants have higher surface energies (which are considered desirable for bone implants) than ethanol-cleaned titanium; (2) higher temperatures of heat treatment of unalloyed titanium result in higher surface energies; and (3) these changes can be related to changes in surface composition and roughness. Thus, unalloyed titanium specimens were either acid-cleaned and passivated (CP) or ethanol-cleaned (Et). Each set was then divided into 3 groups and heat-treated for 1 hour at 316 degrees C (600 degrees F), 427 degrees C (800 degrees F), and 538 degrees C (1,000 degrees F), respectively. Surface roughness values for each of these groups were determined using atomic force microscopy, while surface compositions were determined using Auger electron, x-ray photoelectron, and Raman spectroscopic techniques. Surface energies were estimated using a 2-liquid geometric mean technique and correlated with surface roughness, elemental composition, and elemental thickness. The CP surfaces were slightly rougher than the Et specimens, which had greater oxide thickness and hydrocarbon presence. The surface oxides were composed of TiO2, Ti2O3, and possibly titanium peroxide; those heat-treated at 427 degrees C or above were crystalline. The CP specimens had carbonaceous coverage that was of a different composition from that on Et specimens. The CP specimens had significantly higher surface energies, which showed statistically significant correlations with oxide thickness and carbonaceous presence. In conclusion, ethanol cleaning of unalloyed titanium dental implants may not provide optimal surface properties when compared to cleaning with phosphoric acid followed by nitric acid passivation.

First storage of ion beams in the Double Electrostatic Ion-Ring Experiment: DESIREE.

We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (C(n)(-), n = 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C2 (-) molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s ± 18 s with two independent detector systems. Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10(-14) mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.

The double electrostatic ion ring experiment: a unique cryogenic electrostatic storage ring for merged ion-beams studies.

We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate "rings" and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.

Heterogeneous expression of serine protease inhibitor maspin in ovarian cancer.

UNLABELLED: Ovarian cancer (OC) is a disease with poor prognosis, and molecular markers are needed to improve understanding of disease progression and resultant treatment. Only limited data concerning the expression of maspin, a serine protease inhibitor, in ovarian cancer (OC) are available. This study investigates the prognostic value of maspin expression (ME) in various OC cell lines and clinical tissue specimens from OC patients. PATIENTS AND METHODS: Tumour purified mouse anti-human maspin monoclonal antibody was applied to tissue specimens from 87 OC patients. ME was recorded by an immunoreactive score, which was correlated with grading, stage, histopathological subtypes and overall survival. Additionally ME was evaluated in established ovarian cancer cell lines (HEY, SKOV3, OVCAR3/8) and paclitaxel- and docetaxel-resistant HEY cells by QRT-PCR. RESULTS: There was significant correlation between cytoplasmatic ME and overall survival (p<0.05). OC patients with high levels of ME had a median survival of 28 vs. 57 months for those with low levels. Significant differential ME was detected between benign, borderline ovarian lesions and OC, as well as among different tumour gradings. Normal ovarian epithelial cells expressed less maspin than ovarian cancer cells as measured by QRT-PCR. Docetaxel- and paclitaxel-resistant ovarian cell lines showed an even higher level of ME, suggesting an unfavourable role of ME in OC cell lines. CONCLUSION: Maspin is expressed differentially in OC, and low expression levels of maspin are correlated with a longer survival.

FISH-microdissection (FISH-MD) analysis of complex chromosome rearrangements.

We combined the techniques of fluorescence in situ hybridization (FISH) and chromosomal microdissection in one experiment (FISH-MD). This novel method permits rapid identification of the composition, origin, and breakpoints of rearranged chromosomes. Rearranged chromosomes are first identified by multicolor-FISH, then the fluorophore-labeled derivative chromosomes are directly isolated by microdissection and reverse painted to identify the breakpoints.

Binding of nuclear factors to an upstream region of the human A gamma globin gene.

Two regions in the 5' flanking sequence of the human A gamma globin gene have been identified which bind nuclear factors. One of these regions is located between nucleotides -299 and -140 while the other lies between nucleotides -140 and -60. The former sequence is of interest as this region contains several mutations associated with non-deletion HPFHs. It is possible that factors responsible for the formation of these complexes are involved in developmental regulation of this gene. At the present time it is unknown whether this protein binds at or near the site of the mutations associated with HPFH. It is possible that a protein normally binds to this region in adult erythroid cells and represses expression of the gamma globin genes. When this sequence is altered the factor can not bind and expression of gamma globin genes in adult cells occurs. This could explain the continued production of fetal hemoglobin into adult life. In this model the sites of DNA-factor interaction include the nucleotides at -202, -198, -196 etc. such that nucleotide changes at these positions directly affect factor binding. Alternatively, the sites of DNA factor interaction may be sufficiently proximal to the -202 and -196 region such that single base change at -202, -198, and -196 cause perturbations in the DNA that indirectly effect the DNA-factor interaction. Careful footprinting must be carried out to define the exact binding site. The assay described here provides the basis for the purification of this factor and a study of its interaction with DNA.