bluuebunny/crossref_metadata_2025 huggingface dataset:
Synaptic Vesicles: Test for a Role in Presynaptic Calcium Regulation
Authors: Macleod Greg T. , Marin Leo , Charlton Milton P. , Atwood Harold L.
Published: March 2004

Membrane-bound organelles such as mitochondria and the endoplasmic reticulum play an important role in neuronal Ca2+homeostasis. Synaptic vesicles (SVs), the organelles responsible for exocytosis of neurotransmitters, occupy more of the volume of presynaptic nerve terminals than any other organelle and, under some conditions, can accumulate Ca2+. They are also closely associated with voltage-gated Ca2+channels (VGCCs) that trigger transmitter release by admitting Ca2+into the nerve terminal in response to action potentials (APs). We tested the hypothesis that SVs can modulate Ca2+signals in the presynaptic terminal. This has been a difficult question to address because neither pharmacological nor genetic approaches to block Ca2+permeation of the SV membrane have been available. To investigate the possible role of SVs in Ca2+regulation, we used imaging techniques to compare Ca2+dynamics in motor nerve terminals before and after depletion of SVs. We used the temperature-sensitiveDrosophiladynamin mutantshibire, in which SVs can be eliminated by stimulation. There was no difference in the amplitude or time course of Ca2+responses during high-frequency trains of APs, or single APs, in individual presynaptic boutons before and after depletion of SVs. SVs have a limited role, if any, in the rapid sequestration of Ca2+within the neuronal cytosol or the synaptic microdomain. We also conclude that SVs are not important for regulation of synaptic VGCCs.
Role of Calcium in Neurotensin-Evoked Enhancement in Firing in Mesencephalic Dopamine Neurons
Authors: St-Gelais Fannie , Legault Mark , Bourque Marie-Josée , Rompré Pierre-Paul , Trudeau Louis-Eric
Published: March 2004

Neurotensin (NT) increases neurotransmission within the mesolimbic dopamine system by enhancing the firing rate of dopaminergic (DAergic) neurons and by acting at the nerve terminal level. The signal transduction pathways involved in these effects have not been characterized, but NT receptors are coupled to the phospholipase C pathway and Ca2+mobilization. However, an enhancement of intracellular Ca2+concentration ([Ca2+]i) evoked by NT in DAergic neurons has yet to be demonstrated. Furthermore, the hypothesis that the excitatory effects of NT in DAergic neurons are Ca2+dependant is currently untested. In whole-cell recording experiments, DAergic neurons in culture were identified by their selective ability to express a cell-specific green fluorescent protein reporter construct. These experiments confirmed that NT increases firing rate in cultured DAergic neurons. This effect was Ca2+dependent because it was blocked by intracellular dialysis with BAPTA. Using Ca2+imaging, we showed that NT caused a rapid increase in [Ca2+]iin DAergic neurons. Most of the Ca2+originated from the extracellular medium. NT-induced excitation and Ca2+influx were blocked by SR48692, an antagonist of the type 1 NT receptor. Blocking IP3receptors using heparin prevented the excitatory effect of NT. Moreover, Zn2+andSKF96365both blocked the excitatory effect of NT, suggesting that nonselective cationic conductances are involved. Finally, although NT can also induce a rise in [Ca2+]iin astrocytes, we find that NT-evoked excitation of DAergic neurons can occur independently of astrocyte activation.
Stress Enables Synaptic Depression in CA1 Synapses by Acute and Chronic Morphine: Possible Mechanisms for Corticosterone on Opiate Addiction
Authors: Yang Ya , Zheng Xigeng , Wang Yongfu , Cao Jun , Dong Zhifang , Cai Jingxia , Sui Nan , Xu Lin
Published: March 2004

The hippocampus, being sensitive to stress and glucocorticoids, plays significant roles in certain types of learning and memory. Therefore, the hippocampus is probably involved in the increasing drug use, drug seeking, and relapse caused by stress. We have studied the effect of stress with morphine on synaptic plasticity in the CA1 region of the hippocampusin vivoand on a delayed-escape paradigm of the Morris water maze. Our results reveal that acute stress enables long-term depression (LTD) induction by low-frequency stimulation (LFS) but acute morphine causes synaptic potentiation. Remarkably, exposure to an acute stressor reverses the effect of morphine from synaptic potentiation (∼20%) to synaptic depression (∼40%), precluding further LTD induction by LFS. The synaptic depression caused by stress with morphine is blocked either by the glucocorticoid receptor antagonist RU38486 or by the NMDA-receptor antagonistd-APV. Chronic morphine attenuates the ability of acute morphine to cause synaptic potentiation, and stress to enable LTD induction, but not the ability of stress in tandem with morphine to cause synaptic depression. Furthermore, corticosterone with morphine during the initial phase of drug use promotes later delayed-escape behavior, as indicated by the morphine-reinforced longer latencies to escape, leading to persistent morphine-seeking after withdrawal. These results suggest that hippocampal synaptic plasticity may play a significant role in the effects of stress or glucocorticoids on opiate addiction.
Al2O3 Nanotubes Fabricated by Wet Etching of ZnO/Al2O3 Core/Shell Nanofibers
Authors: Hwang J. , Min B. , Lee J. S. , Keem K. , Cho K. , Sung M.‐Y. , Lee M.‐S. , Kim S.
Published: March 2004

In nanotube‐based electronics, Al2O3 nanotubes will play a very important role. A method is reported that yields nanotubes with controllable, uniform wall thickness. The Figure represents the stage of the synthesis in which ZnO nanowires synthesized on a thick polycrystalline ZnO layer on a Si substrate have been coated with Al2O3 and the ZnO partially etched away. When the etching is complete, Al2O3 nanotubes remain.
Regular Arrays of Copper Wires Formed by Template‐Assisted Electrodeposition
Authors: Zhang M. , Lenhert S. , Wang M. , Chi L. , Lu N. , Fuchs H. , Ming N. B.
Published: March 2004

An easy, cheap, high‐throughput way to generate metallic wire arrays by patterned electrodeposition is reported. Copper is electrodeposited on the surface of a regularly striped Langmuir–Blodgett film, forming an array of submicrometer‐wide wires with homogeneous width (see Figure). Width and separation of the wires can be tuned by the template.
Preparation of Gold Nanowires and Nanosheets in Bulk Block Copolymer Phases under Mild Conditions
Authors: Kim J.‐U. , Cha S.‐H. , Shin K. , Jho J. Y. , Lee J.‐C.
Published: March 2004

Gold nanostructures—nanowires and nanosheets—are reported to have been prepared from the gold salt HAuCl4 in a solid bulk phase of a block copolymer. The Figure shows a SEM image of nanosheets formed by thermal reduction at 70 °C. If water is included in the initial mixture and the reduction occurs by UV irradiation, predominantly nanowires are produced. Reasons for this distinction are discussed.
Semiconductive Polymer Blends: Correlating Structure with Transport Properties at the Nanoscale
Authors: Ionescu‐Zanetti C. , Mechler A. , Carter S. A. , Lal R.
Published: March 2004

Multimodal atomic force microscopy (AFM) was used to map charge transfer properties in correlation to the molecular superstructure of poly(ethyldioxythiophene)–poly(styrenesulfonic acid) (see Figure). The lamellar domains of the polymer blend are indicated by phase shifts. Efficient charge injection occurs when lamellar edges of the superstructure are exposed to a conductive AFM probe. Efficiency of charge injection at polymer–electrode interfaces could be enhanced by controlling lamellar orientation.
Polyelectrolyte Micropatterning Using a Laminar‐Flow Microfluidic Device
Authors: Shchukin D. G. , Kommireddy D. S. , Zhao Y. , Cui T. , Sukhorukov G. B. , Lvov Y. M.
Published: March 2004

Laminar‐flow microfabrication is shown to produce complex micrometer‐resolved polyelectrolyte micropatterns at ambient conditions (see Figure). This simple deposition procedure shows great versatility, with the capacity to fabricate micropatterns containing unstable and sensitive biological objects on the surface of any appropriate substrate.
Carbon Nanotubes with a Triangular Cross‐section, Fabricated Using Anodic Porous Alumina as the Template
Authors: Yanagishita T. , Sasaki M. , Nishio K. , Masuda H.
Published: March 2004

The fabrication of carbon nanotubes (CNTs) with controlled cross‐sectional shapes is reported for the first time. Anodic porous alumina with triangular openings is used as a template for the chemical vapor deposition synthesis of the CNTs with triangular cross‐sections (see Figure). The CNTs can be applied to the fabrication of nanoscale devices that require modified electronic characteristics.
Molecular “Glass” Blowing: From Carbon Nanotubes to Carbon Nanobulbs
Authors: Zhu Z. P. , Su D. S. , Lu Y. , Schlögl R. , Weinberg G. , Liu Z. Y.
Published: March 2004

Molecular‐scale “glass” blowing of multi‐wall carbon nanotubes into nanobulbs (see Figure) is achieved in a unique tube growth environment generated by the explosive decomposition of picric acid. Results indicate that carbon nanotubes have remarkable thermoplasticity and structural fluidity during their generation, and can be engineered into various shaped micro‐vessels or devices.
Microcontact Printing of CdS/Dendrimer Nanocomposite Patterns on Silicon Wafers
Authors: Wu X. C. , Bittner A. M. , Kern K.
Published: March 2004

Micrometer‐scale patterns of blue photoluminescing CdS nanoparticles can be produced by microcontact printing on a hydroxyl‐terminated silicon wafer surface (see Figure). The CdS nanoparticles were synthesized with amine‐terminated generation eight dendrimers as stabilizers. The resulting CdS/dendrimer composite is directly printable due to hydrogen bonds between dendrimer and surface.
New Solvothermal Routes for GaN Nanocrystals
Authors: Sardar K. , Rao C. N. R.
Published: March 2004

GaN nanocrystals (see Figure) of hexagonal structure and varying diameters have been prepared by the reaction of hexamethyldisilazane (HMDS) with gallium cupferron or GaCl3 under solvothermal conditions. The nanocrystals show a size‐dependent photoluminescence band in the 260–320 nm region, characteristic of quantum confinement.
The Dependence of Crystal Structure of Te‐Based Phase‐Change Materials on the Number of Valence Electrons
Authors: Luo M. , Wuttig M.
Published: March 2004

A simple criterion to identify potential phase‐change materials is developed using density functional theory. These compounds rely on the switching between an amorphous and a crystalline state. Here it is demonstrated that suitable alloys have an average valence electron number larger than 4.1 and show p‐electron bonding leading to a six‐fold coordination, while materials with a smaller number of valence electrons favor sp3‐bonding (see Figure).
High‐Conductivity Elastomeric Electronics
Authors: Gray D. S. , Tien J. , Chen C. S.
Published: March 2004

Stretchable electronic circuits have been microfabricated using tortuous gold wires embedded in silicone elastomer. With appropriate geometric parameters, the wires could elongate by more than 50 % while maintaining stable conductivity (see Figure). This technology represents a key development towards conductive fabrics, flexible displays, and other applications that require electronics to withstand unprecedented degrees of stress and vibration.
Material Storage Mechanism in Porous Nanocarbon
Authors: Ajima K. , Yudasaka M. , Suenaga K. , Kasuya D. , Azami T. , Iijima S.
Published: March 2004

Material storage in the inner spaces of nanocarbon materials is visualized for the first time. It is shown that creating paths of a specific size to the inner space (see Figure) is indispensable for material storage in carbon nanopores, and that the adsorption rate for fullerene molecules is largely dependent on the nanoscale curvature of the graphitic planes composing the nanospaces.
Direct Nanopatterning of Metal Surfaces Using Self‐Assembled Molecular Films
Authors: Azzaroni O. , Fonticelli M. H. , Benítez G. , Schilardi P. L. , Gago R. , Caretti I. , Vázquez L. , Salvarezza R. C.
Published: March 2004

A new method for direct patterning of metal surfaces with sub‐50 nm resolution based on molecular films is described (see Figure). Thermal vapor deposition of different metals on chemically surface‐modified nanostructured silicon or metallic masters allows direct pattern transfer and easy film detachment. Patterned metallic surfaces are also used as platforms to grow nanostructured hybrid materials by controlled chemical reactions.
Inorganic Nanocomposites of n‐ and p‐Type Semiconductors: A New Type of Three‐Dimensional Solar Cell
Authors: Nanu M. , Schoonman J. , Goossens A.
Published: March 2004

A new approach to the ‘3D solar‐cell concept’ is reported. Atomic layer chemical vapor deposition is employed to infiltrate CuInS2 into the pores of nanostructured TiO2. In this way it is possible to obtain a nanometer‐scale interpenetrating network between n‐type TiO2 and p‐type CuInS2. Cells created this way show photovoltaic activity with a maximum monochromatic incident photon‐to‐ current conversion efficiency of 80 %.
Ligand‐Directed Assembly of Preformed Titania Nanocrystals into Highly Anisotropic Nanostructures
Authors: Polleux J. , Pinna N. , Antonietti M. , Niederberger M.
Published: March 2004

Highly anisotropic TiO2 nanostructures (see Figure) of several hundreds of nanometers in length were obtained by oriented assembly of preformed TiO2 nanoparticles with typical diameters of 5 nm. The assembly is directed by a particularly small amount of a polydentate ligand with a low molecular weight, which binds selectively to specific crystal faces of the titania nanoparticles.
Highly Efficient Green Phosphorescent Organic Light‐Emitting Diodes Based on CuI Complexes
Authors: Zhang Q. , Zhou Q. , Cheng Y. , Wang L. , Ma D. , Jing X. , Wang F.
Published: March 2004

Mononuclear CuI complexes with mixed ligands are used to fabricate green phosphorescent organic light‐emitting diodes. The electroluminescence (EL) maximum at 524 nm coincides well with its photoluminescent (PL) spectrum in poly(methyl methacrylate) film (see Figure). A maximum current efficiency of 10.5 cd A–1 at 105 cd m–2 and a maximum brightness up to 1663 cd m–2 are demonstrated.
Two‐ and Three‐Dimensional Ordered Structures of Hollow Silver Spheres Prepared by Colloidal Crystal Templating
Authors: Chen Z. , Zhan P. , Wang Z. L. , Zhang J. H. , Zhang W. Y. , Ming N. B. , Chan C. T. , Sheng P.
Published: March 2004

The preparation of ordered arrays of metal hollow spheres via colloidal crystal templating is reported. A seeded growth technique for metal coatings on isolated colloids in solution and a confined template‐directed synthesis method for metal patterning were combined. The polymer colloidal crystal template was prepared and kept stable using a microchannel. 2D and 3D ordered microstructures of silver hollow spheres were obtained (see Figure).
Musculoskeletal stress markers in Natufian hunter‐gatherers and Neolithic farmers in the Levant: The upper limb
Authors: Eshed Vered , Gopher Avi , Galili Ehud , Hershkovitz Israel
Published: March 2004

This paper attempts to quantify the changes in activity patterns of early farming populations in the Levant through the musculoskeletal stress markers (MSM) of the upper limb as seen in skeletal remains. The transition to an agricultural way of life resulted in higher loads on the upper limb in Neolithic populations compared to the Natufian hunter‐gatherer populations that preceded them. The MSM pattern for males and females indicates a gender‐based division of labor both in the Natufian and the Neolithic. It may also suggest that people in the Neolithic period were engaged in different (new) activities and occupations compared to the Natufian. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Petrosal orientation and mandibular ramus breadth: Evidence for an integrated petroso‐mandibular developmental unit
Authors: Bastir Markus , Rosas Antonio , Kuroe Kazuto
Published: March 2004

The absolute and relative breadths of the mandibular ramus (MRB) display substantial variation in modern humans, and are of analytical value in paleoanthropology. According to Enlow et al. ([1969] Am. J. Orthod. 56:6–23), the ramus is the growth counterpart of the middle cranial fossa (MCF) and the pharynx. Such counterpart principles state that variation in ramus breadth is a frequent function of the horizontal alignment of the MCF, and both structures tend to covary within and between populations. These authors also suggested that lateral parts of the basicranium have a particular importance in the positioning of facial components. In the present study, this hypothesis is tested, and relationships between midline and lateral basicranial elements and ramus breadth variation are explored. Two‐dimensional landmarks taken from lateral radiographs of adult crania representative of three modern human populations (Europeans, West Africans, and Japanese) were analyzed by geometric morphometry. Our results are consistent with previous counterpart analyses. Furthermore, our findings highlight the significance of the orientation of the petrous temporal to modern human mandibular ramus variation. Variation in the orientation of the petrosal bone appears to alter the spatial position of the mandible and influences MRB. Developmental integration of a petroso‐mandibular unit may have important paleoanthropological implications. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Effects of birthplace and individual genetic admixture on lung volume and exercise phenotypes of Peruvian Quechua
Authors: Brutsaert Tom D. , Parra Esteban , Shriver Mark , Gamboa Alfredo , Palacios Jose‐Antonio , Rivera Maria , Rodriguez Ivette , León‐Velarde Fabiola
Published: March 2004

Forced vital capacity (FVC) and maximal exercise response were measured in two populations of Peruvian males (age, 18–35 years) at 4,338 m who differed by the environment in which they were born and raised, i.e., high altitude (Cerro de Pasco, Peru, BHA, n = 39) and sea level (Lima, Peru, BSL, n = 32). BSL subjects were transported from sea level to 4,338 m, and were evaluated within 24 hr of exposure to hypobaric hypoxia. Individual admixture level (ADMIX, % Spanish ancestry) was estimated for each subject, using 22 ancestry‐informative genetic markers and also by skin reflectance measurement (MEL). Birthplace accounted for the ∼10% larger FVC (P < 0.001), ∼15% higher maximal oxygen consumption (VO2max, ml . min−1 . kg−1) (P < 0.001), and ∼5% higher arterial oxygen saturation during exercise (SpO2) (P < 0.001) of BHA subjects. ADMIX was low in both study groups, averaging 9.5 ± 2.6% and 2.1 ± 0.3% in BSL and BHA subjects, respectively. Mean underarm MEL was significantly higher in the BSL group (P < 0.001), despite higher ADMIX. ADMIX was not associated with any study phenotype, but study power was not sufficient to evaluate hypotheses of genetic adaptation via the ADMIX variable. MEL and FVC were positively correlated in the BHA (P = 0.035) but not BSL (P = 0.335) subjects. However, MEL and ADMIX were not correlated across the entire study sample (P = 0.282). In summary, results from this study emphasize the importance of developmental adaptation to high altitude. While the MEL‐FVC correlation may reflect genetic adaptation to high altitude, study results suggest that alternate (environmental) explanations be considered. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Population history of native groups in pre‐ and postcontact Spanish Florida: Aggregation, gene flow, and genetic drift on the Southeastern U.S. Atlantic coast
Authors: Stojanowski Christopher M.
Published: March 2004

Evolutionary trends and population history and structure are discussed for a series of late prehistoric and historic‐period skeletal samples from the Georgia coast and interior (the Guale). Phenotypic dental measurement data were collected for nine samples from the late prehistoric (AD 1200–1400) and historic (AD 1608–1702) periods and subjected to population genetic and statistical analyses. The primary trends were for an increase in tooth size through time, and for an initial increase in dental variability in the early historic period, followed by a subsequent decline in dental variability in the late historic period. Given the increasing stress levels, evidenced by previous bioarchaeological analyses (Larsen [2001] Bioarchaeology of Spanish Florida, Gainesville: University Press of Florida), an environmental explanation for the increase in tooth size is unlikely. It is proposed that the early historic period witnessed aggregation and gene flow with extraregional populations, possibly African slaves or nonlocal Native American population groups. The late historic period may have experienced significant loss of phenotypic variability due to genetic drift. In both time periods, the evolutionary mechanism increased average tooth size, with independent variance effects.

Because microevolutionary trends obscure patterns of gene flow and population ancestry, the data were detrended following Konigsberg ([1990a] Hum. Biol. 62:49–70), and submitted to standard population genetic analyses (Relethford et al. [1997] Hum. Biol. 69:443–465). Analysis of the precontact samples in isolation (Irene Mound, Irene Mortuary, and an aggregate coastal sample) indicated little genetic microdifferentiation (FST = 0.008), limited extralocal gene flow, and a small distinction between interior and coastal samples. The inclusion of the historic data dramatically increased variability levels (FST = 0.019). The analysis of extralocal gene flow indicates that the late mission period experienced significantly less external gene flow, which is consistent with historic models that suggest the social organization of the Guale during this time period may have been significantly altered. Genetic distances also indicate a primary division between inland and coastal precontact samples and a maintenance of biological populations along the coast. In other words, the coastal, early historic, and late historic period samples are phenotypically homogenous, supporting the notion that the mission populations were drawn from the local population base. The late mission period sample was also, however, more closely related to the interior samples. This may suggest that the late mission period population was an aggregate sample composed of both remnant interior and coastal population groups. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Is cribra orbitalia synonymous with anemia? Analysis and interpretation of cranial pathology in Sudan
Authors: Wapler Ulrike , Crubézy Eric , Schultz Michael
Published: March 2004

Cribra orbitalia is a porotic or sieve‐like lesion in the bony orbital roof. Its cause has been the object of research and discussion since the end of the 19th century. Since about 1960, most scientists have started to agree on the hypothesis that the lesion is a result of hypertrophy of the red bone marrow, and therefore is proof of anemia. However, recent investigations showed that in some cases, the histologic bone structure does not support the diagnosis of anemia. The status of cribra orbitalia as an indicator then becomes uncertain. We carried out a histologic examination of thin‐ground sections in polarized light to clarify the possible sources of orbital roof lesions in a Nubian population from Missiminia, northern Sudan (n = 333). In at least 56.5% of cribra orbitalia cases, there were no histologic features indicating changes due to anemia. Signs of other pathological conditions, such as inflammation or osteoporosis, as well as pseudopathological cases, were found. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Genetic analysis and ethnic affinities from two Scytho‐Siberian skeletons
Authors: Ricaut François‐Xavier , Keyser‐Tracqui Christine , Cammaert Laurence , Crubézy Eric , Ludes Bertrand
Published: March 2004

We extracted DNA from two skeletons belonging to the Sytho‐Siberian population, which were excavated from the Sebÿstei site (dating back 2,500 years) in the Altai Republic (Central Asia). Ancient DNA was analyzed by autosomal short tandem repeats (STRs) and by the sequencing of the hypervariable region 1 (HV1) of the mitochondrial DNA (mtDNA) control region. The results showed that these two skeletons were not close relatives. Moreover, their haplogroups were characteristic of Asian populations. Comparison with the haplogroup of 3,523 Asian and American individuals linked one skeleton with a putative ancestral paleo‐Asiatic population and the other with Chinese populations. It appears that the genetic study of ancient populations of Central Asia brings important elements to the understanding of human population movements in Asia. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Illness, injury, and disability among Shiwiar forager‐horticulturalists: Implications of health‐risk buffering for the evolution of human life history
Authors: Sugiyama Lawrence S.
Published: March 2004

Human life history is distinguished by long lifespan, delayed reproduction, intergenerational asymmetric benefit transfers from adults to juveniles and between adults, and a large brain able to engage in unprecedented levels of learning, reasoning, and insight. The evolution of these traits depends on relatively low human mortality. Understanding why humans have low mortality is therefore critical for understanding the evolution of key human traits. One explanation is that the evolution of food provisioning during periods of health crisis reduced mortality. This hypothesis turns on health risk having posed a significant adaptive problem that could be effectively buffered by healthcare provisioning. Unfortunately, the frequency, duration, and fitness effects of temporary disability are difficult to estimate based on osteological evidence alone, and systematic ethno‐biological research on these issues among extant small‐scale societies with little access to Western medical care is lacking. Here I present data on 678 injuries and illnesses suffered by 40 Shiwiar forager‐horticulturalists, based on physical evidence and informant reports. A subsample of 17 individuals provided data on incidence and duration of disability for 215 pathological incidents. Results indicate that injury and illness occur frequently across the lifespan. Most living individuals have suffered temporarily disabling health crises likely to have been lethal without provisioning. The fitness effects of surviving these episodes are high, suggesting that the Shiwiar population structure and lifeway are dependent on infrequent extended provisioning to temporarily disabled individuals, and that provisioning of aid during healthcare crises effectively lowers mortality in this small‐scale society. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Early population differentiation in extinct aborigines from Tierra del Fuego‐Patagonia: Ancient mtDNA sequences and Y‐Chromosome STR characterization
Authors: García‐Bour Jaume , Pérez‐Pérez Alejandro , Álvarez Sara , Fernández Eva , López‐Parra Ana María , Arroyo‐Pardo Eduardo , Turbón Daniel
Published: March 2004

Ancient mtDNA was succesfully recovered from 24 skeletal samples of a total of 60 ancient individuals from Patagonia‐Tierra del Fuego, dated to 100–400 years BP, for which consistent amplifications and two‐strand sequences were obtained. Y‐chromosome STRs (DYS434, DYS437, DYS439, DYS393, DYS391, DYS390, DYS19, DYS389I, DYS389II, and DYS388) and the biallelic system DYS199 were also amplified, Y‐STR alleles could be characterized in nine cases, with an average of 4.1 loci per sample correctly typed. In two samples of the same ethnic group (Aonikenk), an identical and complete eight‐loci haplotype was recovered. The DYS199 biallelic system was used as a control of contamination by modern DNA and, along with DYS19, as a marker of American origin. The analysis of both mtDNA and Y‐STRs revealed DNA from Amerindian ancestry. The observed polymorphisms are consistent with the hypothesis that the ancient Fuegians are close to populations from south‐central Chile and Argentina, but their high nucleotide diversity and the frequency of single lineages strongly support early genetic differentiation of the Fuegians through combined processes of population bottleneck, isolation, and/or migration, followed by strong genetic drift. This suggests an early genetic diversification of the Fuegians right after their arrival at the southernmost extreme of South America. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Offene Metallcarboxylat‐Architekturen
Authors: Rao C. N. R. , Natarajan Srinivasan , Vaidhyanathan R.
Published: March 2004

Alumosilicate und Metallphosphate sind die wichtigsten Beispiele für anorganische Materialien mit offenen Gerüsten. In den letzten Jahren stieß zu dieser Gruppe die Familie der Metallcarboxylate, zu der nicht nur Mono‐ und Dicarboxylate von Übergangs‐, Seltenerd‐ und Hauptgruppenmetallen, sondern auch eine Vielzahl von Hybridstrukturen zählen. Einige Carboxylate weisen neuartige magnetische Eigenschaften und Adsorptionseigenschaften auf. Mithilfe von Dicarboxylaten und verwandten Verbindungen kann man effektiv neue poröse Hybridstrukturen erhalten. In einigen dieser Strukturen verbrücken die Dicarboxylateinheiten zwei anorganische Einheiten. Bemerkenswert sind auch die neuen Hybridnanokomposite, in denen Gitter aus Cadmiumoxalat als Wirte für aufgeweitete Alkalimetallhalogenidstrukturen dienen. In diesem Aufsatz beschreiben wir die Synthesen, Strukturen und Eigenschaften von Metallcarboxylaten mit verschiedenartigen offenen Gerüsten.
Titelbild: Combinatorial Catalysis with Bimetallic Complexes: Robust and Efficient Catalysts for Atom‐Transfer Radical Additions (Angew. Chem. 12/2004)
Authors: Quebatte Laurent , Scopelliti Rosario , Severin Kay
Published: March 2004

Hoch effiziente Rh‐Ru‐Katalysatoren für Atomtransfer‐Radikaladditionen wurden durch schnelles Screening identifiziert. Die Katalysatorbibliothek wurde in situ durch Mischen von chlorverbrückten Komplexen von RuII, RuIII, RuIV, RhI, RhIII, IrI, IrIII, PdII und PtII mit drei unterschiedlichen RuII‐Phosphan‐Komplexen erzeugt. Auf S. 1546 beschreiben K. Severin et al. Strukturen und Reaktivitäten der neuen Katalysatoren.
Metal Carboxylates with Open Architectures
Authors: Rao C. N. R. , Natarajan Srinivasan , Vaidhyanathan R.
Published: March 2004

The field of inorganic open‐framework materials is dominated by aluminosilicates and phosphates. The metal carboxylates have emerged as an important family in the last few years. This family includes not only mono‐ and dicarboxylates of transition, rare‐earth, and main‐group metals, but also a variety of hybrid structures. Some of the carboxylates possess novel adsorption and magnetic properties. Dicarboxylates and related species provide an effective means of designing novel hybrid structures with porous and other properties. In some of these structures, the dicarboxylate acts as a linker between two inorganic units. Hybrid nanocomposites are also of particular note, for example, cadmium oxalate host lattices that can accommodate extended alkali‐metal halide structures. This Review discusses the synthesis, structure, and properties of various types of open‐framework metal carboxylates.
Cover Picture: Combinatorial Catalysis with Bimetallic Complexes: Robust and Efficient Catalysts for Atom‐Transfer Radical Additions (Angew. Chem. Int. Ed. 12/2004)
Authors: Quebatte Laurent , Scopelliti Rosario , Severin Kay
Published: March 2004

Highly efficient Rh–Ru catalysts for atom‐transfer radical additions have been discovered in a fast screening assay. The catalyst library used in this assay was generated in situ by mixing chloro‐bridged complexes of RuII, RuIII, RuIV, RhI, RhIII, IrI, IrIII, PdII, and PtII with three different RuII–phosphane complexes. On page 1520 ff., K. Severin and co‐workers describe the structures and reactivities of the new catalysts.
Dissemination of information on legislative mandates and consensus‐based programs addressing payment of the costs of routine care in clinical trials through the World Wide Web
Authors: Kelahan Andrew M.
Published: March 2004

BACKGROUND

Legislative and consensus‐based programs that ensure payment for routine care costs in a trial have been enacted by a number of states and government‐sponsored health benefits programs. To eliminate the potential for denial of payment by a health plan that can act as a barrier to participation, the public must be aware that these programs exist and what they entail.

METHODS

World Wide Web sites are utilized by patients and their surrogates as a prime source of healthcare‐related information. A review of cancer research organization and advocate group web sites was performed to document the degree to which these sites provided information on clinical trial coverage programs. The objective was to determine whether patients were being given sufficient information to overcome barriers to participation related to the existence of clinical trials, their potential benefits, and health plan payment.

RESULTS

Fewer than 5% of the 373 sites reviewed provided sufficient information to communicate to a patient that 1) the institution participates in sponsored cancer clinical research, 2) patients can derive direct benefits by participating in a clinical trial, and 3) payment for treatment in a clinical trial is largely provided by their health plan.

CONCLUSIONS

Sites on the World Wide Web are a key source of healthcare‐related information for patients and their surrogates. Organizations involved in clinical cancer research should examine their web sites to ensure that the content it contains is sufficiently detailed, accessible, and readable to inform potential participants fully of the clinical trial options. Cancer 2004. © 2004 American Cancer Society.
The ethics of reporting and disseminating results of clinical research trials
Authors: Bell Jeffrey G. , Brady Mark , Copeland Larry J.
Published: March 2004

A frank and ethical discussion of results from clinical trials should provide patients with all data that may influence the patient's decision regarding treatment options. Such discussion should include the best available estimate of the treatment benefits as well as a description of the anticipated toxicities.
The impact of testicular carcinoma and its treatment on sperm DNA integrity
Authors: Ståhl Olof , Eberhard Jakob , Jepson Katarina , Spano Marcello , Cwikiel Magdalena , Cavallin‐Ståhl Eva , Giwercman Aleksander
Published: March 2004

BACKGROUND

In patients with testicular germ cell carcinoma (TGCC), spermatogenesis and fertility are impaired. Intracytoplasmic sperm injection has improved their possibility of fatherhood, but might also impose a risk of transmitting DNA defects to the offspring. The aim of the current study was to evaluate the impact of chemotherapy and irradiation on sperm DNA integrity.

METHODS

The study included 74 patients with TGCC. Semen samples were collected before and at specific time points after patients received therapy. Sperm DNA integrity was assessed by the sperm chromatin structure assay. Controls comprised 278 military conscripts.

RESULTS

There was no significant difference in the fraction of sperm with fragmented DNA (DNA fragmentation index [DFI]) between controls and patients with TGCC before postoperative cancer treatment (11% vs. 13%). Men treated with adjuvant radiotherapy had a transiently (up to 2 years) higher DFI than nontreated patients (18% vs. 13%; P = 0.03). Patients who received 1–2 cycles of adjuvant chemotherapy had a significantly lower DFI 6 months after treatment than after 1–2 years (9.1% vs. 13%; P = 0.004). Higher doses of chemotherapy among patients resulted in a significantly lower DFI compared with controls (7.3% vs. 11%; P = 0.028), which persisted throughout the 5 years of follow‐up.

CONCLUSIONS

Postorchiectomy, the DFI in sperm samples from patients with testicular carcinoma was at the level of controls. Radiotherapy caused a transient increase in the proportion of DFI, whereas this value decreased after chemotherapy. The biologic implications of such changes in sperm DNA after cancer therapy need to be elucidated. Cancer 2004. © 2004 American Cancer Society.
Is concurrent chemoradiation the treatment of choice for all patients with Stage III or IV head and neck carcinoma?
Authors: Garden Adam S. , Asper Joshua A. , Morrison William H. , Schechter Naomi R. , Glisson Bonnie S. , Kies Merrill S. , Myers Jeffrey N. , Kian Ang K.
Published: March 2004

BACKGROUND

Many patients with small primary tumors of the oropharynx have AJCC Stage III/IV disease on the basis of lymphadenopathy. In the current retrospective study, the authors hypothesized that these patients have high rates of locoregional control when treated with radiotherapy, either alone or combined with neck surgery, and may not require concurrent chemotherapy.

METHODS

Two hundred ninety‐nine patients met staging and inclusion criteria. Stage distribution was as follows: T1, 99 patients (33%); T2, 182 patients (61%); Tx, 18 patients (6%); N1, 74 patients (25%); N2, 170 patients (57%); N3, 39 patients (13%); and Nx, 16 patients (5%). Primary tumor resection or tonsillectomy had been performed in 36 patients (12%) and excisional lymph node biopsy or formal neck dissection in 192 patients (64%). Thirty‐three additional patients (10%) received chemotherapy and were analyzed separately.

RESULTS

The median follow‐up was 82 months (range, 8–299 months). The actuarial 5‐year rates of locoregional failure, distant metastases, and overall survival were 15%, 19%, and 64%, respectively. T status was associated with the 5‐year rate of locoregional control: 95% for patients with T1‐/Tx disease, compared with 79% for patients with T2 disease (P < 0.01). The 5‐year rate of distant metastases for patients with N1/2a disease was 11%, compared with 28% for patients with N2b/N2c/N3 disease (P < 0.001).

CONCLUSIONS

Patients with early–T status oropharyngeal carcinoma, which is considered advanced due to the presence of lymphadenopathy, have high rates of locoregional control when treated with radiotherapy without or with neck surgery. Local treatment intensification by the addition of concurrent chemotherapy to radiotherapy would not significantly benefit most of these patients. Cancer 2004. © 2004 American Cancer Society.
Thalidomide for patients with recurrent lymphoma
Authors: Pro Barbara , Younes Anas , Albitar Maher , Dang Nam H. , Samaniego Felipe , Romaguera Jorge , McLaughlin Peter , Hagemeister Fredrick B. , Rodriguez Maria A. , Clemons Marilyn , Cabanillas Fernando
Published: March 2004

BACKGROUND

Thalidomide has significant clinical activity in patients with multiple myeloma. However, its activity against other lymphoid tumors is unknown. The authors reported their experience with thalidomide in patients with recurrent/refractory non‐Hodgkin lymphoma and in patients with Hodgkin disease.

METHODS

Nineteen patients (median age, 62 years) who had undergone a median of 5 previous treatment regimens were treated with escalating doses of thalidomide (200–800 mg per day) until disease progression or prohibitive toxicity was observed. The authors measured serum levels of angiogenesis factors before and after treatment.

RESULTS

One patient (5%) with evidence of recurrent gastric mucosa—associated lymphoid tissue lymphoma achieved a complete response, and 3 patients (16%) achieved stable disease.

CONCLUSIONS

The current study suggests that thalidomide has limited single‐agent activity in heavily pretreated patients with recurrent or refractory lymphoma. Cancer 2004. © 2004 American Cancer Society.
Salvage chemotherapy with cyclophosphamide for recurrent, temozolomide‐refractory glioblastoma multiforme
Authors: Chamberlain Marc C. , Tsao‐Wei Denice D.
Published: March 2004

BACKGROUND

The primary objective of the current prospective Phase II study of cyclophosphamide (CYC) in adult patients with recurrent, temozolomide‐refractory glioblastoma multiforme was to evaluate 6‐month progression‐free survival (PFS).

METHODS

Forty patients (28 men and 12 women) ages 28–67 years (median age, 51.5 years), with recurrent glioblastoma multiforme were treated. All patients had been treated previously with surgery and involved‐field radiotherapy (median dose, 60 grays [Gy]; range, 59–61 Gy). In addition, all patients were treated adjuvantly with either nitrosourea‐based chemotherapy (21 patients: procarbazine, lomustine, and vincristine in 13 patients; carmustine in 8 patients) or temozolomide (19 patients). Twenty‐one patients who were treated previously with a nitrosourea were treated with temozolomide at the time of first recurrence. Twenty‐one patients were treated with CYC at the time of second recurrence, and 19 patients were treated with CYC at the time of first recurrence. CYC was administered intravenously on 2 consecutive days (750 mg/m2 per day) every 4 weeks (operationally defined as a single cycle). Neurologic and neuroradiographic evaluations were performed every 8 weeks.

RESULTS

All patients were evaluable. In total, 170 cycles of CYC (median, 2 cycles; range, 2–12 cycles) were administered. CYC‐related toxicity included alopecia in all patients (100%), anemia in 6 patients (3.5%), thrombocytopenia in 7 patients (4.1%), and neutropenia in 9 patients (5.3%). Four patients required transfusions (two required red blood cell transfusion, and two required platelet transfusion). One patient developed neutropenic fever without bacteriologic confirmation. No treatment‐related deaths occurred. Seven patients (17.5%; 95% confidence interval [95% CI], 8–33%) exhibited a neuroradiographic partial response, 11 patients (27.5%; 95% CI, 15–44%) had stable disease, and 22 patients (55%) had progressive disease after a single cycle of CYC. The time to tumor progression ranged from 2 months to 18 months (median, 2 months). Survival ranged from 3 months to 24 months (median, 4 months). In patients with either a neuroradiographic response or stable disease (n = 18 [45%]), the median time to tumor progression was 6 months (range, 4–18 months; 95% CI, 6–8 months), and the median survival was 10 months (range, 5–24 months; 95% CI, 8–10 months). The 6‐month PFS rate was 20%.

CONCLUSIONS

CYC exhibited modest efficacy with acceptable toxicity in the current cohort of adult patients with recurrent glioblastoma multiforme, all of whom had previously experienced treatment failure after temozolomide chemotherapy. Cancer 2004. © 2004 American Cancer Society.
Pegylated liposomal doxorubicin‐efficacy in patients with recurrent high‐grade glioma
Authors: Hau Peter , Fabel Klaus , Baumgart Ulrike , Rümmele Petra , Grauer Oliver , Bock Annekatrin , Dietmaier Christopher , Dietmaier Wolfgang , Dietrich Jörg , Dudel Christine , Hübner Franz , Jauch Tanya , Drechsel Elisabeth , Kleiter Ingo , Wismeth Cäcile , Zellner Anton , Brawanski Alexander , Steinbrecher Andreas , Marienhagen Jörg , Bogdahn Ulrich
Published: March 2004

BACKGROUND

Doxorubicin exhibits high efficacy in malignant glioma cell cultures. Nonetheless, as a standard formulation, doxorubicin has not been used clinically, due to poor penetration of the blood‐brain barrier. Furthermore, doxorubicin is known to induce tumor resistance genes. To address both of these issues, the authors investigated the use of pegylated liposomal doxorubicin (Caelyx™; Essex Pharma, Munich, Germany) alone (Trial 1) and in combination with tamoxifen (Trial 2) in two sequentially performed nonrandomized prospective Phase II trials involving patients with recurrent high‐grade glioma.

METHODS

Twenty patients were included in each trial. Progression‐free survival at 6 months (PFS‐6) and toxicity were the primary endpoints. Expression of the tumor resistance proteins multidrug resistance protein 1 (MDR‐1) and multiple resistance protein (MRP) was evaluated by immunohistochemical methods and by sestamibi–single‐photon emission computed tomography (SPECT).

RESULTS

The overall response rate (including cases of disease stabilization) was 40% in both Trial 1 and Trial 2. PFS‐6 was 15%, and the median time to disease progression was 17 weeks. It is noteworthy that 40% of patients with Grade III tumors had long‐term responses, which lasted for up to 3 years. There was no significant difference between Trial 1 and Trial 2 in terms of efficacy. Both regimens were well tolerated, with the main side effect being palmoplantar erythrodysesthesia. The authors found no correlation between clinical response and expression of tumor resistance genes or between clinical response and SPECT data.

CONCLUSIONS

Pegylated liposomal doxorubicin administered alone or in combination with tamoxifen is safe and moderately effective in patients with recurrent high‐grade glioma. None of the putative predictors for response that were evaluated proved to be significant in this setting. Cancer 2004. © 2004 American Cancer Society.
A multicenter study of the prognosis and treatment of adult brain ependymal tumors
Authors: Reni Michele , Brandes Alba Ariela , Vavassori Vittorio , Cavallo Giovanna , Casagrande Federica , Vastola Francesca , Magli Alessandro , Franzin Alberto , Basso Umberto , Villa Eugenio
Published: March 2004

BACKGROUND

The current analysis of outcomes in a large series of adult patients with intracranial ependymal tumors contributes to the characterization of the primary prognostic factors and to the therapeutic management of this rare disease, for which limited information is available in the literature.

METHODS

The authors analyzed data on patient and tumor characteristics, treatment, and survival in a series of 70 patients age > 17 years with pathologic diagnoses of brain ependymal tumors from 4 institutions.

RESULTS

The 5‐ and 10‐year overall survival (OS) rates (± standard errors) were 67% ± 6% and 50% ± 8%, respectively. The 5‐ and 10‐year failure‐free survival (FFS) rates were 43% ± 7% and 24% ± 6%, respectively. Younger age and infratentorial tumor location were associated with longer survival. Among patients with Grade 2 ependymoma (n= 51), 21 (41%) received no postsurgical treatment. These 21 patients had a 5‐year OS rate of 78% ± 10% and a 10‐year OS rate of 68% ± 13%; the 5‐ and 10‐year FFS rates for these patients were 47% ± 12% and 12% ± 11%, respectively. Twenty‐six patients with Grade 2 ependymoma (51%) received postoperative radiotherapy (RT). These 26 patients had a 5‐year OS rate of 71% ± 9% and a 10‐year OS rate of 59% ± 11%; the 5‐ and 10‐year FFS rates for these patients were 54% ± 10% and 34% ± 10%, respectively. Among patients with Grade 2 ependymoma, neither OS nor FFS differed significantly between those who did not receive postoperative RT and those who did; however, these two groups were heterogeneous with respect to prognostic factors. On multivariate analysis, RT use exhibited a trend toward improved OS and was significantly predictive of improved FFS.

CONCLUSIONS

The current analysis does not rule out the possibility that deferral of RT at the time of recurrence could have a detrimental effect on FFS or OS in patients with Grade 2 ependymoma, regardless of the degree of ablation. The role of postoperative RT for patients who undergo imaging‐based macroscopic total resection remains to be addressed. Cancer 2004. © 2004 American Cancer Society.