bluuebunny/crossref_metadata_2025 huggingface dataset:
Lévy flights and Lévy-Schrödinger semigroups
Authors: Garbaczewski Piotr
Published: November 2009

We analyze two different confining mechanisms for Lévy flights in the presence of external potentials. One of them is due to a conservative force in the corresponding Langevin equation. Another is implemented by Lévy-Schrödinger semigroups which induce so-called topological Lévy processes (Lévy flights with locally modified jump rates in the master equation). Given a stationary probability function (pdf) associated with the Langevin-based fractional Fokker-Planck equation, we demonstrate that generically there exists a topological Lévy process with the same invariant pdf and in reverse.
Gamma-ray production in the 170Er(p,n)170Tm nuclear reaction
Authors: Mihailescu Alexandru , Cata-Danil Gheorghe
Published: November 2009

For the first time discrete gamma-rays following the nuclear reaction 170Er(p,n)170Tm with enriched target were measured with a high resolution GeHP spectrometer. Protons delivered by the Bucharest FN Tandem Van de Graaff accelerator bombarded a thin self-supporting film of enriched erbium. Measured γ-ray energies (Eγ), their relative intensities (Iγ) and corresponding excitation functions for the beam energy range 2.0–3.6 MeV are reported in the present work. The measured excitation functions were fairly well reproduced by compound nucleus calculations based on the Hauser-Feshbach formalism.
The telomere-specific non-LTR retrotransposons SART1 and TRAS1 are suppressed by Piwi subfamily proteins in the silkworm, Bombyx mori
Authors: Tatsuke Tsuneyuki , Sakashita Kosuke , Masaki Yuki , Lee Jae , Kawaguchi Yutaka , Kusakabe Takahiro
Published: November 2009

The telomere structures in Bombyx mori are thought to be maintained mainly by the transposition of the specialized telomeric retroelements SART and TRAS. The silkworm genome has telomeric TTAGG repeats and telomerase, but this telomerase displays little or no activity. Here, we report that the transcription of the telomeric retroelements SART1 and TRAS1 is suppressed by the silkworm Piwi subfamily proteins BmAgo3 and Siwi. The silkworm Piwi subfamily was found to be expressed predominantly in the gonads and early embryo, as in other model organisms, but in BmN4 cultured cells, these proteins formed granules that were separate from the nuage, which is a different behaviour pattern. The expression of TRAS1 was increased in BmN4 cells when BmAgo3 or Siwi were silenced by RNAi. Our results suggest that B. mori Piwi proteins are involved in regulating the transposition of telomeric retroelements, and that the functional piRNA pathway is conserved in BmN4 cultured cells.
The historical anthropology of thought
Authors: Humphreys S. C.
Published: November 2009

This article illustrates the need for a historical anthropology of the longue durée, dealing with pre-modern societies, by analyzing the work of Jean-Pierre Vernant on the development of thought in ancient Greece. Vernant's anthropologies began with Marx and the historical psychologist Ignace Meyerson; he was influenced by the Durkheimian Louis Gernet and later by Lévi-Strauss. His early interest in relating Greek rationality to social organization led him increasingly into work on Greek religion and tragedy. This article builds on his work by studying the social contexts of communication that facilitated the proposal and elaboration of unconventional ideas.
Hepatitis C virus infection: Diagnosis and treatment
Authors: Sultan Md Tipu , Haque Mahmudul , Dewanjee Arup Kanti , Mazed MA
Published: November 2009

doi: 10.3329/jcmcta.v18i1.3817Journal of Chittagong Medical College Teachers' Association 2007: 18(1):23-28
Types and outcomes of spinal cord tumors: A study of 30 cases attending the Department of Neurosurgery in Chittagong Medical College Hospital, Chittagong
Authors: Nath Haradhan Den , Rahman Md Zillur , Uddin Md Kamal , Rahman Md Lutfor , Hasan Suzon Al , Mustafa Sheikh Golam , Das Khokan Kanti
Published: November 2009

Key words: extradural; intradural; extramedullary; intramedullary; metastasisdoi: 10.3329/jcmcta.v18i2.3824Journal of Chittagong Medical College Teachers' Association 2007: 18(2):11-15
Clinical profile of the patients with chronic low back pain - A study of 102 cases
Authors: Shakoor M Abdus , Islam Md Ariful , Ullah Md Ahsan , Ahmed Md Mozaffor , Hasan Suzon Al
Published: November 2009

doi: 10.3329/jcmcta.v18i2.3825Journal of Chittagong Medical College Teachers' Association 2007: 18(2):16-20
Role of flurochrome stain in the diagnosis of leprosy
Authors: Ahamad M Shahab Uddin , Ahmed ASM Mostaque , Rahman AJEN
Published: November 2009

doi: 10.3329/jcmcta.v19i1.3845Journal of Chittagong Medical College Teachers' Association 2008: 19(1):15-16
Study of plasma fibrinogen in cases with hypertriglyceridemia
Authors: Aziz Rehana , Haque Mahmudul , Chowdhury Md Sirajul Islam , Ghose Sankar Kumar , Taher MA , Sultan Md Tipu
Published: November 2009

doi: 10.3329/jcmcta.v19i1.3846Journal of Chittagong Medical College Teachers' Association 2008: 19(1):17-19
Fentanyl as a premedication for anaesthesia in paediatric surgery
Authors: Matin Md Abdul , Ali Mohammad , Mannan Md Abdul , Chowdhury ASM Alamgir
Published: November 2009

doi: 10.3329/jcmcta.v19i1.3848Journal of Chittagong Medical College Teachers' Association 2008: 19(1):23-27
Caroli's disease presenting with haematemesis and melaena
Authors: Das Uzzwal Kanti , Chowdhury Mohammad Ibrahim
Published: November 2009

Key words: Caroli's disease; cholangitis; oesophageal varices; ductal stone; ductal plate; ductal plate malformation central dot sign; common bile ductdoi: 10.3329/jcmcta.v19i1.3853Journal of Chittagong Medical College Teachers' Association 2008: 19(1):46-49
Laparoscopic adrenal cystectomy - report of two cases
Authors: Hossain GM Zakir , Rahman Mofizur , Hasan Mohammad Rashedul
Published: November 2009

Key words: laparoscopic; adrenal cystectomydoi: 10.3329/jcmcta.v19i1.3854Journal of Chittagong Medical College Teachers' Association 2008: 19(1):50-53
Between the Artwork and its ‘Actualization’: a Footnote to Art History in Benjamin's ‘Work of Art’ Essay
Authors: Doherty Brigid
Published: November 2009

This article analyses a footnote to the third version of the ‘Work of Art’ essay in which Walter Benjamin presents an account of ‘a certain oscillation’ between ‘cult value’ and ‘exhibition value’ as typical of the reception of all works of art. Benjamin's example in that footnote is the Sistine Madonna (1512–13), a painting by Raphael in the Dresden Gemäldegalerie that has played an important part in German aesthetics since Winckelmann. Benjamin's footnote on the Sistine Madonna, along with his critique of Hegel's aesthetics in that context, demand to be understood in relation to his remarks on Dada elsewhere in the artwork essay, and to his claim that technological reproducibility leads to the ‘actualization’ of the original reproduced. In that connection, the article concludes with an analysis of Kurt Schwitters's 1921 montage picture Knave Child Madonna with Horse.
Muslim–Christian Relations and the Third Crusade: Medievalist Imaginings
Authors: Bradford Clare
Published: November 2009

This article takes as its starting-point the responsiveness of children's literature to socio-political events, considering how contemporary anxieties about relationships between Muslim and Christian individuals and cultures inform three historical novels set in the period of the Third Crusade (1189–92): Karleen Bradford's Lionheart's Scribe (1999), K. M. Grant's Blood Red Horse (2004), and Elizabeth Laird's Crusade (2008). In these novels, encounters between young Christian and Muslim protagonists are represented through language and representational modes which owe a good deal to the habits of thought and expression which typify orientalist discourses in Western fiction. In effect, the novels produce two versions of medievalism: a Muslim medieval world which is irretrievably pre-modern, locked into rigid practices and beliefs against which individuals are powerless; and a Christian medieval world which offers individuals the possibility of progressing to an enhanced state of personal fulfilment. The article argues that the narratives of all three novels incorporate particularly telling moments when Christian protagonists return to England, regretfully leaving Muslim friends. The impossibility of enduring friendships between Muslims and Christians is based on the novels’ assumptions about the incommensurability of cultures and religions; specifically, that there exists an unbridgeable gulf between Islam and Christianity.
Ignorant Armies on a Darkling Plain: The New World Disorder of Global Economics, Environmentalism and Urbanisation in Philip Reeve's Hungry Cities
Authors: McCallum Robyn
Published: November 2009

As world economies have become increasingly globalised, cities have undergone dramatic transformations, resulting in a new economic order with minimal localisable terrain; simultaneously, there has been enormous urban growth. These developments have had significant implications for natural environments and the lived physical/social environments of human beings. Philip Reeve's Hungry Cities [Mortal Engines] Chronicles explores the complex relationships between global economics, urbanisation and environmentalism by mapping these onto two utopian models: utopianisms of process; and spatial utopias. This paper examines the paradigmatic function of these two models within Reeve's tetralogy, focusing on the implications of each for thinking through interrelationships between capitalism, environmentalism and urbanisation. Economic, urban and natural spaces are envisaged throughout the Chronicles as ‘cyborgian’, and, hence, capable of adaptation but also apt to stagnation. They thus embody both threat and promise: they warn of an annihilation of the human spirit, but also remember the humanity's heterogeneity. Reeve directly invokes these diverse possibilities in his depiction of warring cities, envisaging a distinctly posthuman world, but one within which human relationships, alongside a sense of the importance of history and narrative, offer certainty and the possibility at least for the construction of urban communities grounded on utopian ideals.
‘The world of television microwave dinners, air-conditioning and Have a Nice Day’: Representations of Globalisation in Two Young Adult Novels
Authors: Wortley Emma
Published: November 2009

Young adult fiction that overtly engages with globalisation has emerged over the past decade, reflecting a growing cultural attendance to a phenomenon that purportedly shapes our world. Fictional narratives, including young adult novels, provide one sphere of information, ideas and attitudes related to globalisation. This paper examines globalisation as represented by discourses associated with mass media and consumerism in two young adult novels: So Yesterday by Scott Westerfeld (2004) and Deep Fried by Bernard Beckett and Clare Knighton (2006) . With a focus on the depiction of brand names and advertising in So Yesterday and television in Deep Fried, this article presents textual examples that convey ambivalence toward discourses associated with globalisation and argues that in this respect the texts are somewhat open and questioning rather than entirely deterministic or didactic. While, overall, So Yesterday and Deep Fried are not particularly radical, the ambivalent aspects of the texts suggest that young adult fiction has the potential to produce more interrogative narratives in which the globalised world and the young adult's place within it are negotiable rather than inevitable.
Factors Affecting Template Usage in the Development of K65R Resistance in Subtype C Variants of HIV Type-1
Authors: Coutsinos Dimitrios , Invernizzi Cédric F , Xu Hongtao , Brenner Bluma G , Wainberg Mark A
Published: November 2009

Background:

We have shown that the K65R resistance mutation in HIV type-1 (HIV-1) reverse transcriptase (RT) is selected more rapidly in subtype C than subtype B HIV-1 in biochemical, cell culture and clinical studies. Template-usage experiments demonstrated that subtype C nucleotide coding sequences caused RT to preferentially pause, leading to K65R acquisition. This new study now further establishes the basis for differential occurrence of both K65R and thymidine analogue mutations (TAMs) between subtypes.

Methods:

Gel-based nucleotide extension assays were used to study the homopolymeric sequence surrounding K65.

Results:

When positive double-stranded DNA synthesis was evaluated from a negative single-stranded DNA template, pausing at the 67 region, which is linked to occurrence of TAMs, was alleviated with both subtype B and C templates at high dCTP concentrations, but this alleviation was more pronounced with the subtype C template. By contrast, pausing at the 65 region on the subtype C but not subtype B template always occurred and was not alleviated at high levels of nucleotide triphosphates or by other means. Furthermore, templates containing repeats of the homopolymeric sequence spanning codons 64–66 of pol showed corresponding pausing repeats at the 65 region with the subtype C template only. Inverted RNA and DNA templates both displayed pausing at position K65 for the subtype C template and a ladder of pausing events culminating at codon 67 for the subtype B templates.

Conclusions:

These results further establish a mechanistic basis for the exclusion of both K65R and TAMs on single templates as well as the preferential acquisition of K65R in subtype C viruses.
Synthesis and characterization of new (N‐diphenylphosphino)‐isopropylanilines and their complexes: crystal structure of (Ph2P S)NHC6H44CH(CH3)2 and catalytic activity of palladium(II) complexes in the Heck and Suzuki cross‐coupling reactions
Authors: Aydemir Murat , Baysal Akın , Gürbüz Nevin , Özdemir İsmail , Gümgüm Bahattin , Özkar Saim , Çaylak Nagihan , Yıldırım Leyla Tatar
Published: November 2009

Three new (N‐diphenylphosphino)‐isopropylanilines, having isopropyl substituent at the carbon 2‐ (1) 4‐ (2) or 2,6‐ (3) were prepared from the aminolysis of chlorodiphenylphosphine with 2‐isopropylaniline, 4‐isopropylaniline or 2,6‐diisopropylaniline, respectively, under anaerobic conditions. Oxidation of 1,2 and 3 with aqueous hydrogen peroxide, elemental sulfur or gray selenium gave the corresponding oxides, sulfides and selenides (Ph2PE)NHC6H42‐CH(CH3)2, (Ph2PE)NHC6H44‐CH(CH3)2 and (Ph2PE)NHC6H42,6‐{CH(CH3)2}2, where E = O, S, or Se, respectively. The reaction of [M(cod)Cl2] (M = Pd, Pt; cod = 1,5‐cyclooctadiene) with two equivalents of 1,2 or 3 yields the corresponding monodendate complexes [M((Ph2P)NHC6H42‐CH(CH3)2)2Cl2], M = Pd 1d, M = Pt 1e, [M((Ph2P)NHC6H44‐CH(CH3)2)2Cl2], M = Pd 2d, M = Pt 2e and [M((Ph2P)NHC6H42,6‐(CH(CH3)2)2)2Cl2], M = Pd 3d, M = Pt 3e, respectively. All the compounds were isolated as analytically pure substances and characterized by NMR, IR spectroscopy and elemental analysis. Furthermore, representative solid‐state structure of [(Ph2PS)NHC6H44‐CH(CH3)2] (2b) was determined using single crystal X‐ray diffraction technique. The complexes 1d–3d were tested and found to be highly active catalysts in the Suzuki coupling and Heck reaction, affording biphenyls and stilbenes, respectively. Copyright © 2009 John Wiley & Sons, Ltd.
A study on the heterobinuclear site of Co(salen)/TiO2SiO2 catalysts in the oxidative carbonylation of aniline
Authors: Mei Fu‐Ming , Chen Li‐Juan , Li Guang‐Xing
Published: November 2009

Titania‐silica immobilized Co(salen) complexes containing the heterobinuclear site were prepared by the sol–gel method for the catalytic synthesis of methyl N‐phenylcarbamate (MPC) by the oxidative carbonylation of aniline. It was found that the Ti:Si mole ratio had an important effect on the catalytic performance of Co(salen) complexes. When the Ti:Si ratio was 0.1, titania‐silica supported Co(salophen) showed the best catalytic activity. Under the reaction conditions, Co(salophen)/TS‐0.1, 0.5 g, aniline 11 mmol, methanol 25 ml, KI 2.2 mmol, CO:O2 9:1, total pressure 6 MPa, 150 °C, 3 h, the conversion of aniline and the selectivity of MPC were 60.7 and 88.1%, respectively. The XRD studies showed that titania was highly dispersed in the silica matrix. Co(salophen)/TS‐0.1 was reused five times with no significant loss of the activity, and no Co leaching was observed in the reaction. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and reactivity of some diselenasila cycles containing an annelated dicarba‐closo‐dodecaborane(12) unit
Authors: Wrackmeyer Bernd , Klimkina Elena V. , Milius Wolfgang
Published: November 2009

The use of 1,2‐diselenolato‐1,2‐dicarba‐closo‐dodecaborane(12) dianions [1,2‐(1,2‐C2B10H10)Se2]2− prepared in situ as the dilithium salt may lead to irreproducible results. This is shown by the straightforward synthesis of silanes using the purified and isolated dianions, in contrast with previous less successful attempts. Thus, the reactions of the dianions with dichlorosilanes afford the five‐membered diselenasila cycles containing the SiMe2 or the SiPh2 units, and with 1,2‐dichloro‐tetramethyldisilane the six‐membered cycle containing the Si2Me4 unit. The latter was studied by X‐ray diffraction, and all products were characterized by multinuclear magnetic resonance (1H, 13C, 29Si, 77Se NMR) in solution. Novel isotope effects were detected in 13C and 77Se NMR spectra. Exchange reactions of the five‐ and six‐membered diselanasila cycles with chlorosilanes were studied. Copyright © 2009 John Wiley & Sons, Ltd.
Palladium(II)‐catalyzed catalytic aminocarbonylation and alkoxycarbonylation of terminal alkynes: regioselectivity controlled by the nucleophiles
Authors: Suleiman Rami , Tijani Jimoh , El Ali Bassam
Published: November 2009

The aminocarbonylation and alkoxycarbonylation reactions of terminal alkynes took place smoothly and efficiently using a catalyst system Pd(OAc)2–dppb–p‐TsOHCH3CNCO under relatively mild experimental conditions. The catalytic system was tested and optimized using two different nucleophiles: alcohols and amines. Phenylacetylene (1a) was considered as an alkyne along with diisobutylamine (2b1) and methanol (2c1) as nucleophiles. The results showed significant differences in the conversion of 1a and in the selectivity towards the gem or trans unsaturated esters or amides with these nucleophiles. The effects of the type of palladium catalysts, the type of ligands, the amount of dppb and the solvents were carefully studied. With diisobutylamine (2b1), excellent regioselectivity towards the 2‐acrylamides (gem isomer, 3ab1) was almost always observed, while trans‐α,β‐unsaturated esters 4ac1 was the predominant product with methanol (2c1) as a nucleophile. This remarkable sensitivity in the selectivity of the reaction indicates two different possible mechanistic pathways for these carbonylation reactions. Copyright © 2009 John Wiley & Sons, Ltd.
Evaluation of the Brain Network Organization From EEG Signals: A Preliminary Evidence in Stroke Patient
Authors: De Vico Fallani Fabrizio , Astolfi Laura , Cincotti Febo , Mattia Donatella , la Rocca Daria , Maksuti Elira , Salinari Serenella , Babiloni Fabio , Vegso Balazs , Kozmann Gyorgy , Nagy Zoltan
Published: November 2009

Synchronous brain activity in motor cortex in perception or in complex cognitive processing has been the subject of several studies. The advanced analysis of cerebral electro‐physiological activity during the course of planning (PRE) or execution of movement (EXE) in a high temporal resolution could reveal interesting information about the brain functional organization in patients following stroke damage. High‐power (128 channels) electroencephalography registration was carried out on 8 healthy subjects and on a patient with stroke with capsular lacuna in the right hemisphere. For activation of motor cortex, the finger tapping paradigm was used. In this preliminary study, we tested a theoretical graph approach to characterize the task‐related spectral coherence. All of the obtained brain functional networks were analyzed by the connectivity degree, the degree distribution, and efficiency parameters in the Theta, Alpha, Beta, and Gamma bands during the PRE and EXE intervals. All the brain networks were found to hold a regular and ordered topology. However, significant differences (P < 0.01) emerged between the patient with stroke and the control subjects, independently of the neural processes related to the PRE or EXE periods. In the Beta (13–29 Hz) and Gamma (30–40 Hz) bands, the significant (P < 0.01) decrease in global‐ and local‐efficiency in the patient's networks, reflected a lower capacity to integrate communication between distant brain regions and a lower tendency to be modular. This weak organization is principally due to the significant (P < 0.01 Bonferroni corrected) increase in disconnected nodes together with the significant increase in the links in some other crucial vertices. Anat Rec, 292:2023–2031, 2009. © 2009 Wiley‐Liss, Inc.
Ischemic Tolerance: The Mechanisms of Neuroprotective Strategy
Authors: Lehotský Jan , Burda Jozef , DanielisovÁ Viera , Gottlieb Miroslav , Kaplán Peter , Saniová Beata
Published: November 2009

The phenomenon of ischemic tolerance perfectly describes this quote “What does not kill you makes you stronger.” Ischemic pre‐ or postconditioning is actually the strongest known procedure to prevent or reverse neurodegeneration. It works specifically in sensitive vulnerable neuronal populations, which are represented by pyramidal neurons in the hippocampal CA1 region. However, tolerance is effective in other brain cell populations as well. Although, its nomenclature is “ischemic” tolerance, the tolerant phenotype can also be induced by other stimuli that lead to delayed neuronal death (intoxication). Moreover, the recent data have proven that this phenomenon is not limited to application of sublethal stimuli before the lethal stress but reversed arrangement of events, sublethal stress after lethal insult, is rather equally effective. A very important term is called “cross conditioning.” Cross conditioning is the capability of one stressor to induce tolerance against another. So, since pre‐ or post‐conditioners can be used plenty of harmful stimuli, hypo‐ or hyperthermia and some physiological compounds, such as norepinephrine, bradykinin. Delayed neuronal death is the slow development of postischemic neurodegeneration. This allows an opportunity for a great therapeutic window of 2–3 days to reverse the cellular death process. Moreover, it seems that the mechanisms of ischemic tolerance‐delayed postconditioning could be used not only after ischemia but also in some other processes leading to apoptosis. Anat Rec, 292:2002–2012, 2009. © 2009 Wiley‐Liss, Inc.
Toward the Treatments with Neural Stem Cells: Experiences from Amyotrophic Lateral Sclerosis
Authors: Mitrečić Dinko , Gajović Srećko , Pochet Roland
Published: November 2009

Common pathological features of neurodegenerative diseases are progressive dysfunction and neuronal death. In amyotrophic lateral sclerosis (ALS), motor neurons are selectively affected, leading to death because of paralysis. The main therapeutic goal in neurodegenerative diseases is to diminish neural dysfunction and to replace non‐functional cells with the new ones. “Cell‐oriented” treatment strategies include isolation of neural stem cells (NSC), their controlled differentiation, and cellular injections targeting the affected region. Beneficial effects of injected cells result from the combination of cell replacement and secretion of the growth factors. Here, we summarize the current state of isolation and differentiation of NSC, and emphasize the embryo tail bud as a particular region where neuroepithelium differentiates from undifferentiated mesenchymal cells over the course of normal development. The possibility to obtain cells from autologous mesenchyme capable of integrating into affected regions represents a major challenge whose achievement should circumvent the pitfall of the immune reaction against transplanted cells. We also present our own results: when intravenously injected in symptomatic ALS rats, NSC migrated to the motor cortex and continued to differentiate. Thus, we illustrate that the use of NSC in rodent models of ALS may represent a paradigm for other neurodegenerative diseases. Anat Rec, 292:1962–1967, 2009. © 2009 Wiley‐Liss, Inc.
From Birth Till Death: Neurogenesis, Cell Cycle, and Neurodegeneration
Authors: Demir Ozlem , Singh Sheila , Klimaschewski Lars , Aksan Kurnaz Isil
Published: November 2009

Neurogenesis in the embryo involves many signaling pathways and transcriptional programs and an elaborate orchestration of cell cycle exit in differentiating precursors. However, while the neurons differentiate into a plethora of different subtypes and different identities, they also presume a highly polar structure with a particular morphology of the cytoskeleton, thereby making it almost impossible for any differentiated cell to re‐enter the cell cycle. It has been observed that dysregulated or forced cell cycle reentry is closely linked to neurodegeneration and apoptosis in neurons, most likely through changes in the neurocytoskeleton. However, proliferative cells still exist within the nervous system, and adult neural stem cells (NSCs) have been identified in the Central Nervous System (CNS) in the past decade, raising a great stir in the neuroscience community. NSCs present a new therapeutic potential, and much effort has since gone into understanding the molecular mechanisms driving differentiation of specific neuronal lineages, such as dopaminergic neurons, for use in regenerative medicine, either through transplanted NSCs or manipulation of existing ones. Nevertheless, differentiation and proliferation are two sides of the same coin, just like tumorigenesis and degeneration. Tumor formation may be regarded as a de‐differentiation of tissues, where cell cycle mechanisms are reactivated in differentiated cell types. It is thus important to understand the molecular mechanisms underlying various brain tumors in this perspective. The recent Cancer Stem Cell (CSC) hypothesis also suggests the presence of Brain Tumor Initiating Cells (BTICs) within a tumor population, although the exact origin of these rare and mostly elusive BTICs are yet to be identified. This review attempts to investigate the correlation of neural stem cells/precursors, mature neurons, BTICs and brain tumors with respect to cell cycle regulation and the impact of cell cycle in neurodegeneration. Anat Rec, 292:1953–1961, 2009. © 2009 Wiley‐Liss, Inc.
In Vivo Morphological Changes in Animal Models of Amyotrophic Lateral Sclerosis and Alzheimer's‐Like Disease: MRI Approach
Authors: Andjus Pavle R. , Bataveljić Danijela , Vanhoutte Greetje , Mitrecic Dinko , Pizzolante Fabrizio , Djogo Nevena , Nicaise Charles , Kengne Fabrice Gankam , Gangitano Carlo , Michetti Fabrizio , van der Linden Annemie , Pochet Roland , Bačić Goran
Published: November 2009

Magnetic resonance imaging (MRI) is the only noninvasive technique that provides structural information on both cell loss and metabolic changes. After reviewing all the results obtained in clinical studies, reliable biomarkers in neurological diseases are still lacking. Diffusional MRI, MR spectroscopy, and the assessment of regional atrophy are promising approaches, but they cannot be simultaneously used on a single patient. Thus, for further research progress, reliable animal models are needed. To this aim, we have used the clinical MRI to assess neurodegenerative processes in the hSOD‐1G93A ALS rat model and in the trimethyltin (TMT)‐treated model of Alzheimer's‐like disease. T2‐weighted (T2W) hyperintensive neurodegenerative foci were found in the brainstem of the ALS rat with apparent lateral ventricle dilation (T1W—hypointensity vs. T2W—hyperintensity). Degenerative processes in these areas were also confirmed by confocal images of GFAP‐positive astrogliosis. MRI after i.v.i. of magnetic anti‐CD4 antibodies indicated an accumulation of inflammatory cells near dilated ventricles. TMT‐treated rats also revealed the dilation of lateral ventricles. Expected deterioration in the hippocampus was not observed by clinical MRI, but immunocytochemistry could reveal significant redistribution of macro‐ and microglia in this structure. In both models, Gd‐DTPA contrast revealed a compromised blood brain barrier that may serve as the passage for inflammatory immune cells in the vicinity of dilated lateral ventricles. Moreover, in both models the midbrain region of the dorsal hippocampus was the target of BBB compromise, thus revealing a potentially vulnerable point that can be the primary target of neurodegeneration in the central nervous system. Anat Rec, 292:1882–1892, 2009. © 2009 Wiley‐Liss, Inc.
Synaptotagmins in Neurodegeneration
Authors: Glavan Gordana , Schliebs Reinhard , Živin Marko
Published: November 2009

Synaptotagmins (Syts) are transmembrane proteins involved in the regulation of membrane trafficking. Here, we summarize literature data that provide growing evidence that several Syts are involved in the pathophysiological mechanisms of temporal lobe epilepsy and Parkinson's disease, as well as few reports related to brain ischemia and Alzheimer's disease (AD). We also report new data from our laboratories, showing changes of the expression of several Syts in Tg2576 mouse model of AD that may be related to neuroinflammation surrounding the β‐amyloid plaques. Furthermore, we demonstrate N‐methyl‐D‐aspartate receptor‐mediated upregulation of Syt 4 mRNA in a model of excitotoxic striatal lesion induced by unilateral striatal injection of quinolinic acid, associating the upregulation of Syt 4 with mechanisms of excitotoxicity. We propose that phamacological manipulation of Syt expression in animal models of neurodegeneration should be further explored, as it may help to clarify the role of individual Syt isoforms in the regulation of membrane trafficking in neurodegeneration. Anat Rec, 292:1849–1862, 2009. © 2009 Wiley‐Liss, Inc.
Plasticity and Neural Stem Cells in the Enteric Nervous System
Authors: Schäfer Karl‐Herbert , Ginneken Chris Van , Copray Sjef
Published: November 2009

The enteric nervous system (ENS) is a highly organized part of the autonomic nervous system, which innervates the whole gastrointestinal tract by several interconnected neuronal networks. The ENS changes during development and keeps throughout its lifespan a significant capacity to adapt to microenvironmental influences, be it in inflammatory bowel diseases or changing dietary habits. The presence of neural stem cells in the pre‐, postnatal, and adult gut might be one of the prerequisites to adapt to changing conditions. During the last decade, the ENS has increasingly come into the focus of clinical neural stem cell research, forming a considerable pool of neural crest derived stem cells, which could be used for cell therapy of dysganglionosis, that is, diseases based on the deficient or insufficient colonization of the gut by neural crest derived stem cells; in addition, the ENS could be an easily accessible neural stem cell source for cell replacement therapies for neurodegenerative disorders or traumatic lesions of the central nervous system. Anat Rec, 292:1940–1952, 2009. © 2009 Wiley‐Liss, Inc.
Laser‐Induced Autofluorescence Measurements on Brain Tissues
Authors: Pascu Alexandru , Romanitan Mihaela Oana , Delgado Josè‐Maria , Danaila Leon , Pascu Mihail–Lucian
Published: November 2009

It was demonstrated that comparison of the autofluorescence spectra induced with laser radiation in ultraviolet and visible allows the identification of brain tumor tissues and normal tissues as well as the difference between them. The measurements were performed on homogenates to ensure an optimal reproducibility of the results. We conclude that the autofluorescence spectra of the tumor samples are close to those measured for normal tissues, but there are differences between them that allow distinguishing the tumor from the normal tissue. One difference is that for each pair of tumor/normal tissue samples, the peak autofluorescence for the normal tissue is shifted with respect to that for the tumor–typically between 10 and 20 nm; overall autofluorescence intensity is also different for the components of the same pair, the difference being in the range 15%–30%. A parameter that can also be used is the variation of the ratio of some fluorescence intensity peaks between normal and tumor tissue samples. Measurements of this parameter yielded variations ranging between 10% and 40%. Another conclusion of the study is that in vitro experiments show that it is mandatory to use pairs of samples (normal/tumor tissue) taken from the same patient. The results show that, after further experimental in vitro tests, the method may be adapted to real‐time intraoperative conditions by measuring the autofluorescence of the tumor and of the adjacent normal tissue. Anat Rec, 292:2013–2022, 2009. © 2009 Wiley‐Liss, Inc.
Significance and importance: some common misapprehensions about statistics
Authors: Currey John D. , Baxter Paul D. , Pitchford Jonathan W.
Published: November 2009

There are many common misapprehensions about statistics that occur in the literature. We are sure that the three misapprehensions we deal with in this short review are widespread. They concern:

what P values mean;

what an insignificant result means, and what it does not mean; the question of the ‘power’ of a statistical test;

the difference between importance and statistical significance.

We produce no formulae or recipes for dealing with particular situations, instead we concentrate on the commonsense use of simple statistics. We emphasise that if the use of any but the simplest statistics is intended, it is much better to get proper statistical help before starting experiments, rather than afterwards. Copyright © 2009 John Wiley & Sons, Ltd.
Molecular and Supramolecular Structural Studies on Significant Repetitive Sequences of Resilin
Authors: Tamburro Antonio M. , Panariello Simona , Santopietro Valentina , Bracalello Angelo , Bochicchio Brigida , Pepe Antonietta
Published: November 2009

Resilin is a member of the family of elastomeric proteins and is found in specialised regions of the cuticle of most insects, and provides low stiffness, high strain and efficient energy storage. It is best known for its role in insect flight and the remarkable jumping ability of fleas and spittle bugs. In common with other elastomeric proteins, the recently identified Drosophila melanogaster proresilin shows glycine‐rich repetitive sequences; in particular the N‐ and C‐terminal regions of the protein are dominated by 18 repeats of a 15‐residue sequence (SDTYGAPGGGNGGRP) and eleven repeats of a 13‐residue sequence (GYSGGRPGGQDLG), respectively. We synthesised and analysed the molecular and supramolecular structure of some polypeptides with sequences belonging to the glycine‐rich repeated domain of D. melanogaster resilin. The conformational studies performed by CD, FTIR and NMR spectroscopies pointed to the coexistence of two main conformational features, such as folded β‐turns and (quasi)extended structures (e.g., poly‐L‐proline II conformation) in common with other elastomeric proteins; this suggests an elasticity mechanism for resilin common to other elastomeric proteins. Our data show that also in the case of resilin, repetitive sequences are characterised by autonomous structures almost independent of the remaining parts of the molecule as already extensively found for elastin. From a supramolecular point of view, a great tendency to aggregate in fibrous structures is observed, particularly for the resilin‐ inspired polypeptide (PGGGN)10. This is encouraging for the development of resilin‐based biomaterials for the production of biocompatible medical devices, as well as high performing elastic materials.
Biocatalysis with Thermostable Enzymes: Structure and Properties of a Thermophilic ‘ene’‐Reductase related to Old Yellow Enzyme
Authors: Adalbjörnsson Björn V. , Toogood Helen S. , Fryszkowska Anna , Pudney Christopher R. , Jowitt Thomas A. , Leys David , Scrutton Nigel S.
Published: November 2009

We report the crystal structure of a thermophilic “ene” reductase (TOYE) isolated from Thermoanaerobacter pseudethanolicus E39. The crystal structure reveals a tetrameric enzyme and an active site that is relatively large compared to most other structurally determined and related Old Yellow Enzymes. The enzyme adopts higher order oligomeric states (octamers and dodecamers) in solution, as revealed by sedimentation velocity and multiangle laser light scattering. Bead modelling indicates that the solution structure is consistent with the basic tetrameric structure observed in crystallographic studies and electron microscopy. TOYE is stable at high temperatures (Tm>70 °C) and shows increased resistance to denaturation in water‐miscible organic solvents compared to the mesophilic Old Yellow Enzyme family member, pentaerythritol tetranitrate reductase. TOYE has typical ene‐reductase properties of the Old Yellow Enzyme family. There is currently major interest in using Old Yellow Enzyme family members in the preparative biocatalysis of a number of activated alkenes. The increased stability of TOYE in organic solvents is advantageous for biotransformations in which water‐miscible organic solvents and biphasic reaction conditions are required to both deliver novel substrates and minimize product racemisation.
Entwicklung einer Enzymplattform für die biokatalytische C–C‐Verknüpfung
Authors: Pohl M. , Gocke D. , Müller M. , Kolter G.
Published: November 2009

Trotz der wachsenden Beliebtheit von Enzymen als Biokatalysatoren in der organischen Synthese wird deren Anwendung oft dadurch eingeschränkt, dass ein geeignetes Enzym für eine spezielle gewünschte Reaktion nicht schnell genug verfügbar ist. Der Aufbau von Enzymplattformen kann die Suche nach geeigneten Enzymen entscheidend verkürzen. Es wird eine Enzymplattform für die Herstellung chiraler 2‐Hydroxyketone durch C–C‐Verknüpfung von Aldehyden vorgestellt. Chirale 2‐Hydroxyketone sind wertvolle Bausteine für die Herstellung von bioaktiven Molekülen z. B. in der Pharmazie und im Pflanzenschutz. Die Enzymplattform besteht aus diversen natürlichen und gentechnisch veränderten Enzymen. Durch die genaue Kenntnis von Reaktionsmechanismus und der dreidimensionalen Strukturen war es möglich, gezielt Enzymvarianten mit ganz speziellen Eigenschaften herzustellen, die eine große Vielfalt an 2‐Hydroxyketonen zugänglich machen können.
Vom Gen zum Produkt: Maßgeschneiderte Oligosaccharide durch Substrat‐, Enzym‐ und genetisches Engineering
Authors: Seibel J.
Published: November 2009

Neue Strategien sind erforderlich für die Synthese und den Zugang komplexer Oligosaccharide und Glycokonjugate. Die Kombination von Enzym‐ und Substrat‐Engineering eröffnet eine Vielzahl neuer synthetischer Möglichkeiten bezüglich der Synthese von Oligosacchariden. Durch das Engineering der Enzyme gelingen das Steuern der Stereoselektivität und auch das Erweitern der Substratspezifität. Doch auch durch geeignete Wahl der Substrate können enzymatische Reaktionen in gewünschte Richtungen dirigiert werden. Jedoch liegt die besondere Stärke der Synthese in der Kombination beider Ansätze, die die synthetischen Möglichkeiten eines „althergebrachten Enzymes”︁ um ein Vielfaches erweitern kann.
New Antimicrobial Hexapeptides: Synthesis, Antimicrobial Activities, Cytotoxicity, and Mechanistic Studies
Authors: Sharma Rohit K. , Sundriyal Sandeep , Wangoo Nishima , Tegge Werner , Jain Rahul
Published: November 2009

Synthetic antimicrobial peptides have recently emerged as promising candidates against drug‐resistant pathogens. We identified a novel hexapeptide, Orn‐D‐Trp‐D‐Phe‐Ile‐D‐Phe‐His(1‐Bzl)‐NH2, which exhibits broad‐spectrum antifungal and antibacterial activity. A lead optimization was undertaken by conducting a full amino acid scan with various proteinogenic and non‐proteinogenic amino acids depending on the hydrophobic or positive‐charge character of residues at various positions along the sequence. The hexapeptide was also cyclized to study the correlation between the linear and cyclic structures and their respective antimicrobial activities. The synthesized peptides were found to be active against the fungus Candida albicans and Gram‐positive bacteria such as methicillin‐resistant Staphylococcus aureus and methicillin‐resistant Staphylococcus epidermidis, as well as the Gram‐negative bacterium Escherichia coli; MIC values for the most potent structures were in the range of 1–5 μg mL−1 (IC50 values in the range of 0.02–2 μg mL−1). Most of the synthesized peptides showed no cytotoxic effects in an MTT assay up to the highest test concentration of 200 μg mL−1. A tryptophan fluorescence quenching study was performed in the presence of negatively charged and zwitterionic model membranes, mimicking bacterial and mammalian membranes, respectively. The results of the fluorescence study demonstrate that the tested peptides are selective toward bacterial over mammalian cells; this is associated with a preferential interaction between the peptides and the negatively charged phospholipids of bacterial cells.
Hydrogen Radical Additions to Unsaturated Hydrocarbons and the Reverse β‐Scission Reactions: Modeling of Activation Energies and Pre‐Exponential Factors
Authors: Sabbe Maarten K. , Reyniers Marie‐Françoise , Waroquier Michel , Marin Guy B.
Published: November 2009

The group additivity method for Arrhenius parameters is applied to hydrogen addition to alkenes and alkynes and the reverse β‐scission reactions, an important family of reactions in thermal processes based on radical chemistry. A consistent set of group additive values for 33 groups is derived to calculate the activation energy and pre‐exponential factor for a broad range of hydrogen addition reactions. The group additive values are determined from CBS‐QB3 ab‐initio‐calculated rate coefficients. A mean factor of deviation of only two between CBS‐QB3 and experimental rate coefficients for seven reactions in the range 300–1000 K is found. Tunneling coefficients for these reactions were found to be significant below 400 K and a correlation accounting for tunneling is presented. Application of the obtained group additive values to predict the kinetics for a set of 11 additions and β‐scissions yields rate coefficients within a factor of 3.5 of the CBS‐QB3 results except for two β‐scissions with severe steric effects. The mean factor of deviation with respect to experimental rate coefficients of 2.0 shows that the group additive method with tunneling corrections can accurately predict the kinetics and is at least as accurate as the most commonly used density functional methods. The constructed group additive model can hence be applied to predict the kinetics of hydrogen radical additions for a broad range of unsaturated compounds.
Global Minimum‐Energy Structure and Spectroscopic Properties of I2.−⋅n H2O Clusters: A Monte Carlo Simulated Annealing Study
Authors: Pathak Arup Kumar , Mukherjee Tulsi , Maity Dilip Kumar
Published: November 2009

The vibrational (IR and Raman) and photoelectron spectral properties of hydrated iodine‐dimer radical‐anion clusters, I2.−⋅n H2O (n=1–10), are presented. Several initial guess structures are considered for each size of cluster to locate the global minimum‐energy structure by applying a Monte Carlo simulated annealing procedure including spin–orbit interaction. In the Raman spectrum, hydration reduces the intensity of the II stretching band but enhances the intensity of the OH stretching band of water. Raman spectra of more highly hydrated clusters appear to be simpler than the corresponding IR spectra. Vibrational bands due to simultaneous stretching vibrations of OH bonds in a cyclic water network are observed for I2.−⋅n H2O clusters with n≥3. The vertical detachment energy (VDE) profile shows stepwise saturation that indicates closing of the geometrical shell in the hydrated clusters on addition of every four water molecules. The calculated VDE of finite‐size small hydrated clusters is extrapolated to evaluate the bulk VDE value of I2.− in aqueous solution as 7.6 eV at the CCSD(T) level of theory. Structure and spectroscopic properties of these hydrated clusters are compared with those of hydrated clusters of Cl2.− and Br2.−.
Electrochemical Properties of Phospholipid Monolayers at Liquid–Liquid Interfaces
Authors: Santos Hélder A. , García‐Morales Vladimir , Pereira Carlos M.
Published: November 2009

Biomembrane models built at the interface between two immiscible electrolytes (ITIES) are useful systems to study phenomena of biological relevance by means of their electrochemical processes. The unique properties of ITIES allow one either to control or measure the potential difference across the biomimetic membranes. Herein we focus on phospholipid monolayers adsorbed at liquid–liquid interfaces, and besides discussing recent developments on the subject, we describe electrochemical techniques that can be used to get insight on the interfacial processes and electrostatic properties of phospholipid membranes at the ITIES. In particular, we examine the electrochemical and physicochemical properties of (modified) phospholipid monolayers and their interaction with other biologically relevant compounds. The use of liquid–liquid electrochemistry as a powerful tool to characterize drug properties is outlined. Although this review is not a survey of all the work in the field, it provides a comprehensive referencing to current research.
Using End Groups to Tune the Linear and Nonlinear Optical Properties of Bis(dioxaborine)‐Terminated Polymethine Dyes
Authors: Matichak Jonathan D. , Hales Joel M. , Ohira Shino , Barlow Stephen , Jang Sei‐Hum , Jen Alex K.‐Y. , Brédas Jean‐Luc , Perry Joseph W. , Marder Seth R.
Published: November 2009

Six anionic pentamethine dyes with different 2,2‐difluoro‐4‐aryl‐1,3,2(2 H)‐dioxaborin‐6‐yl termini were synthesized and isolated as tetra‐n‐octylammonium salts with a variety of aryl groups appended to increase conjugation beyond the dioxaborine termini. The increased conjugation was expected to decrease the energy of the lowest‐lying excited state, and increase the transition dipole moment linking this state to the ground state, which would be anticipated to result in an increase in the real part of the third‐order polarizability, Re(γ). UV/Vis‐NIR absorption spectroscopy indicates that the absorption maxima in DMSO vary from 691 to 761 nm, with the longest wavelength transitions observed for a derivative where the aryl group is 4‐nitrophenyl. Closed‐aperture Z‐scan measurements at 1.3 μm in DMSO indicate that Re(γ) varies from −2.9×10−33 to −5.4×10−33 esu in these systems. The largest magnitude of Re(γ) was observed for a dye with E‐4‐styrylphenyl aryl groups. This result can be rationalized using a two‐state expression which relates Re(γ) to the energy and transition dipole moment of the transition from the ground state to the lowest‐lying excited state. A nonamethine analogue of this compound was also synthesized and exhibits a slightly larger Re(γ) with respect to a previously reported bis(dioxaborine)‐terminated nonamethine. The extension of conjugation beyond the dioxaborine termini seems to result in an overall increase in Re(γ). However, the effects are smaller than those found by increasing conjugation in the polymethine bridge due to reduced participation of terminal groups in the HOMO.
Churg‐Strauss and Goodpasture's syndromes: A rare association
Authors: Carrilho Patricia , Cruz Pedro , Natario Ana , Rocha Carla , Assuncao Jose , Barreto Carlos , Vaz Alvaro , Martins Ana Paula , Vinhas Jose
Published: November 2009

Churg‐Strauss is a rare syndrome with only a few hundred cases reported in the literature. Overlap with other vasculitic disorders is even more unusual, although some cases have been described. Patients may have several phases of the syndrome over many years, before the development of systemic vasculitis. We report the case of a patient whose clinical and pathological evolution suggests an initial presentation consistent with Churg‐Strauss and a subsequent evolution to Goodpasture disease, a sequential development that had not yet been reported. Recent efforts to classify vasculitis according to clinical and pathological features have been most helpful in guiding diagnosis and therapeutic options, although some clinical cases still represent a challenge.