bluuebunny/crossref_metadata_2025 huggingface dataset:
Synaptic Depolarizing GABA Response in Adults Is Excitatory and Proconvulsive When GABAB Receptors Are Blocked
Authors: Kantrowitz Joshua T. , Francis N. Noelle , Salah Alejandro , Perkins Katherine L.
Published: April 2005

In the presence of 4-aminopyridine, interneurons fire synchronously, causing giant GABA-mediated postsynaptic potentials (GPSPs; GPSCs in voltage clamp) in CA3 pyramidal cells in hippocampal slices from adult guinea pigs. These triphasic GPSPs are composed of a GABAA-mediated hyperpolarizing component, a depolarizing component, and a GABAB-mediated hyperpolarizing component. We propose that GABAB receptors exert control over the postsynaptic depolarizing GABA response. Microelectrode and cell-attached recordings demonstrated that the mean number of action potentials during the depolarizing component of the GPSP increased dramatically in the presence of the GABAB receptor antagonist (2S)-3-[[(1S)-1-(3,4-dichlorophenyl)ethyl]amino-2- hydroxypropyl](phenylmethyl) phosphinic acid (CGP 55845A; P = 0.003 and 0.0005, respectively). Whole cell voltage-clamp recordings showed that the postsynaptic GABAB and depolarizing GABA components of the GPSC overlap substantially, allowing the GABAB-mediated hyperpolarization to suppress the excitation mediated by the depolarizing GABA component. Further voltage-clamp recordings showed that CGP 55845A increased the duration of the depolarizing GABA component of the GPSC even when the GABAB component had already been blocked by internal QX-314, suggesting that CGP 55845A also increased the duration of GABA release. When glutamatergic transmission is intact, GPSPs directly precede epileptiform afterdischarges. We hypothesize that the depolarizing component of the GPSP triggers the epileptiform events and show here that enhancement of the depolarizing component with CGP 55845A increased epileptiform activity. CGP 55845A increased the likelihood of a GPSP triggering an epileptiform event from 32 to 99% ( P = 0.0000001), and significantly increased the number of afterdischarges per epileptiform event ( P = 0.001). Loss of GABAB receptor function is associated with temporal lobe epilepsy in rodents and humans. We show here that GABAB receptors exert control over the synaptic depolarizing GABA response and that block of GABAB receptors makes the depolarizing GABA response excitatory and proconvulsive.
Response Characterstics of Spinothalamic Tract Neurons That Project to the Posterior Thalamus in Rats
Authors: Zhang Xijing , Giesler Glenn J.
Published: April 2005

A sizeable number of spinothalamic tract axons terminate in the posterior thalamus. The functional roles and precise areas of termination of these axons have been a subject of recent controversy. The goals of this study were to identify spinothalamic tract neurons (STT) within the cervical enlargement that project to this area, characterize their responses to mechanical and thermal stimulation of their receptive fields, and use microantidromic tracking methods to determine the nuclei in which their axons terminate. Forty-seven neurons were antidromically activated using low-amplitude (≤30 μA) current pulses in the contralateral posterior thalamus. The 51 points at which antidromic activation thresholds were lowest were surrounded by ineffective tracks indicating that the surrounded axons terminated within the posterior thalamus. The areas of termination were located primarily in the posterior triangular, medial geniculate, posterior and posterior intralaminar, and suprageniculate nuclei. Recording points were located in the superficial and deep dorsal horn. The mean antidromic conduction velocity was 6.4 m/s, a conduction velocity slower than that of other projections to the thalamus or hypothalamus in rats. Cutaneous receptive fields appeared to be smaller than those of neurons projecting to other areas of the thalamus or to the hypothalamus. Each of the examined neurons responded exclusively or preferentially to noxious stimuli. These findings indicate that the STT carries nociceptive information to several target nuclei within the posterior thalamus. We discuss the evidence that this projection provides nociceptive information that plays an important role in fear conditioning.
Polyamorous Women, Sexual Subjectivity and Power
Authors: Sheff Elisabeth
Published: April 2005

This article explores polyamorous women’s potential to enlarge the concept of sexual subjectivity through their engagement in nontraditional relationships and their attempts to reject sexual objectification. Polyamorous people openly engage in romantic, sexual, and/or affective relationships with multiple people simultaneously. Polyamory differs from swinging with its emphasis on long-term, emotionally intimate relationships and from adultery with its focus on honesty and (ideally) full disclosure of the network of sexual relationships to all who participate in or are affected by them. Both men and women have access to additional partners in polyamorous relationships, distinguishing them from polygamy. This ethnographic analysis expands sociological understanding of women’s sexuality by investigating this previously unexamined area of sexual subjectivity. Specifically, the author analyzes some of the ways that polyamorous women expand so-called normal social roles, discusses their sexual lives and identities, and explores novel and traditional forms of power polyamorous practice engenders for these women’s relationships.
Style and Action
Authors: Kidder Jeffrey L.
Published: April 2005

Using a social world’s perspective, this article looks at the style of New York City bike messengers. Combining the works of Hebdige and Biernacki, it is argued that messenger style is intertwined with messenger practice. Five stylistic elements are analyzed: riding behaviors, the use of helmets, bicycle choice, clothing, and language. In each case, evidence is presented to illustrate how a liminal social position and an outlaw character is expressed within the signs messengers display.
Altered gene expression in human cells induced by the agricultural chemical Enable
Authors: Mankame T , Hokanson R , Chowdhary R , Busbee D
Published: April 2005

Steroid hormones bind to highly specific nuclear receptors, regulating gene expression that results in normal fetal growth and development and/or in normal adult physiological function. Many industrial and agricultural chemicals may bind one or more nuclear receptors, acting as mimics of steroid hormones, and are called endocrine disruptive chemicals (EDC) because they alter the expression of endocrine-regulated genes. A widely used fungicide, Enable (fenbuconazole), was evaluated to examine its capacity to alter endocrine-regulated gene expression. Cells of an oestrogen-dependent human breast cancer-derived line, MCF-7, were treated with a range, 0.033-3.3 ppb (ng/mL), of Enable, and gene expression was compared to that of untreated cells. Microarray analysis using a chip with 600 gene spots showed downregulation of eight genes and upregulation of 34 genes in cells treated with 3.3 ppb of Enable, compared to untreated cells. Specific genes were selected for consideration. Real-time PCR confirmed results obtained from analysis of the microarray data for the genes phenol sulphotransferase (PST), intercellular adhesion molecule-1 (ICAM-1), transforming growth factor b-3 (TGF b-3) and calreticulin. These studies were designed to provide base-line data on the gene expression-altering capacity of a specific chemical at a low dose, and will allow assessment of the possible deleterious effects that may be caused in human cells by exposure to the agricultural chemical Enable.
Morphometric analysis of mice uteri treated with the preservatives methyl, ethyl, propyl, and butylparaben
Authors: Lemini C , Hernández A , Jaimez R , Franco Y , Avila ME , Castell A
Published: April 2005

The alkyl esters of p-hydroxybenzoic acid (PHBA) known as parabens (Pbens) are widely used as preservatives in food, pharmaceuticals, and cosmetics. Several in vivo and in vitro studies have shown these compounds to be estrogenic. Here, for the first time, we present evidence of their estrogenicity using a morphometric analysis of uteri from mice treated with the preservatives methylparaben (MePben), ethylparaben (EtPben), propylparaben (PrPben), and butylparaben (BuPben) compared with estradiol (E2). Different groups of adult ovariectomized (Ovx) CD1 mice were subcutaneously (sc) treated daily for three days with two different equimolar doses (362 and 1086 mmol/kg) of the Pbens: MePben (55 and 165 mg/kg), EtPben (60 and 180 mg/kg), PrPben (65 and 195 mg/kg), BuPben (70 and 210 mg/kg), E2 (10 mg/kg; 0.036 mmol/kg), and vehicle (propyleneglycol; V, 10 mL/kg). On the fourth day, uteri were dissected, blotted, weighed, and placed in a fixative solution for 24 h. The paraffin embeded uteri were cut to obtain 7 mm thick transversal sections. Luminal epithelium heights (LEH), glandular epithelium heights (GEH), and myometrium widths (MW) were measured. The highest Pbens dose was able to produce uterotrophic effects (38 to 76%) compared to E2 efects (100%). The relative uterotrophic potency to E2 (100) was from 0.02 to 0.009. Significant increases ( P <0.05) in LEH, GEH, and MW as compared with V were obtained: LEH from 87 to 113% (E2 153%), GEH from 10 to 40% (E2 60%), and MW from 35 to 43% (E2 88%). These results confirm that Pbens at the doses assayed here induce estrogenic histological changes in the uteri of Ovx mice.
Loss ofpatchedand disruption of granule cell development in a pre-neoplastic stage of medulloblastoma
Authors: Oliver Trudy G. , Read Tracy Ann , Kessler Jessica D. , Mehmeti Anriada , Wells Jonathan F. , Huynh Trang T. T. , Lin Simon M. , Wechsler-Reya Robert J.
Published: April 2005

Medulloblastoma is the most common malignant brain tumor in children. It is thought to result from the transformation of granule cell precursors (GCPs) in the developing cerebellum, but little is known about the early stages of the disease. Here, we identify a pre-neoplastic stage of medulloblastoma in patched heterozygous mice, a model of the human disease. We show that pre-neoplastic cells are present in the majority of patched mutants,although only 16% of these mice develop tumors. Pre-neoplastic cells, like tumor cells, exhibit activation of the Sonic hedgehog pathway and constitutive proliferation. Importantly, they also lack expression of the wild-type patched allele, suggesting that loss of patched is an early event in tumorigenesis. Although pre-neoplastic cells resemble GCPs and tumor cells in many respects, they have a distinct molecular signature. Genes that mark the pre-neoplastic stage include regulators of migration, apoptosis and differentiation, processes crucial for normal development but previously unrecognized for their role in medulloblastoma. The identification and molecular characterization of pre-neoplastic cells provides insight into the early steps in medulloblastoma formation, and may yield important markers for early detection and therapy of this disease.
Six3functions in anterior neural plate specification by promoting cell proliferation and inhibitingBmp4expression
Authors: Gestri Gaia , Carl Matthias , Appolloni Irene , Wilson Stephen W. , Barsacchi Giuseppina , Andreazzoli Massimiliano
Published: April 2005

Although it is well established that Six3 is a crucial regulator of vertebrate eye and forebrain development, it is unknown whether this homeodomain protein has a role in the initial specification of the anterior neural plate. In this study, we show that exogenous Six3 can expand the anterior neural plate in both Xenopus and zebrafish, and that this occurs in part through Six3-dependent transcriptional regulation of the cell cycle regulators cyclinD1 and p27Xic1, as well as the anti-neurogenic genes Zic2 and Xhairy2. However, Six3 can still expand the neural plate in the presence of cell cycle inhibitors and we show that this is likely to be due to its ability to repress the expression of Bmp4 in ectoderm adjacent to the anterior neural plate. Furthermore, exogenous Six3 is able to restore the size of the anterior neural plate in chordino mutant zebrafish, indicating that it has the ability to promote anterior neural development by antagonising the activity of the BMP pathway. On its own, Six3 is unable to induce neural tissue in animal caps, but it can do so in combination with Otx2. These results suggest a very early role for Six3 in specification of the anterior neural plate, through the regulation of cell proliferation and the inhibition of BMP signalling.
Use of bioelectrical impedance analysis to determine body composition changes in HIV-associated wasting
Authors: Klauke Stephan , Fischer Harald , Rieger Armin , Frühauf Lukas , Staszewski Schlomo , Althoff Peter-Henning , Helm Eilke Brigitte
Published: April 2005

AIDS wasting syndrome results in loss of lean body mass and body cell mass. This 12-week, open-label study used bioelectrical impedance analysis to measure body composition changes in 24 patients with AIDS wasting syndrome receiving recombinant human growth hormone (r-hGH). The primary endpoint was percentage monthly change in body weight before/after r-hGH. Secondary endpoints included change from baseline in body composition (bioelectrical impedance analysis), isometric strength and CD4+count. Twenty patients completed the study: r-hGH resulted in mean weight gains (+2.7%, P=0.146), and significant increases in mean body cell mass (+8.0%, P=0.0211), lean body mass (+4.8%, P=0.0373) and water (+5.5%, P<0.023). Body fat decreased throughout, but not significantly. r-hGH was generally well tolerated; the most frequent adverse events were fever (7.3%) and diarrhoea (6.3%). Thus, bioelectrical impedance analysis can detect improved body cell mass independent of changes in body weight resulting from r-hGH treatment in patients with AIDS wasting syndrome.
Higher vaginal pH is associated with Chlamydia trachomatis infection in women: a prospective case–controlled study
Authors: Das Satyajit , Sabin Caroline , Allan Sriskandab
Published: April 2005

This is a prospective case–controlled study of female attendees in Coventry. This study found an association of higher vaginal pH with chlamydial infection, independent of any other factors. Studies in vitro have shown that an acidic vaginal secretion inhibits chlamydial infection. Our objective was to analyse the association of vaginal pH and chlamydial infection in women attending a genitourinary medicine clinic. Chlamydial infections were diagnosed with ELISA and confirmed with indirect immunofluorescence. Vaginal pH was measured by a pH indicator tape ranging from 3 to 8. Consecutive female attendees with no sexually transmitted infections (STIs) were included as controls. In all, 144 female cases, diagnosed with chlamydial infection, had a median age of 20 years. Seventeen women had associated bacterial vaginosis. Eighty-two women had no other STIs. Ninety-eight women were using the oral contraceptive pill (OCP). The 145 control women had a median age of 26 years and 52 were receiving the OCP. A significantly higher vaginal pH was seen in the cases ( P=0.0001, Wilcoxon test), even after adjusting for other risk factors associated with vaginal pH, including OCP use (odds ratio: 6.49, 95% confidence interval, 3.59–11.73, P=0.0001). Chlamydial infection in women was associated with a higher vaginal pH level, independent of any other factors. This study has implications for the treatment of other conditions known to lead to an increase in vaginal pH, even in asymptomatic individuals.
The role of the nurse in screening asymptomatic male and female patients in a sexual health clinic
Authors: Munday P E , Allan A , Hearne S , Gubbay A
Published: April 2005

We allocated 278 patients, who said they were asymptomatic and agreed to be randomized to a nurse or doctor clinic, to appointments using a random number system. In all, 35 patients did not attend and 16 were excluded because they did not meet the entry criteria. We used a screening protocol which excluded microscopy from the immediate assessment of patients. The outcome measures were completeness of documentation, proportion of patients accepting HIV tests, infections detected and patient satisfaction. Overall, 3% of items were not completed by doctors and 6% by nurses. HIV tests were carried out on 65% of patients who saw a doctor and 52% who saw a nurse. Thirteen infections were detected by doctors and 27 by nurses. No new cases of gonorrhoea, syphilis or HIV infection were identified. Eighty-eight patients completed a questionnaire after their attendance. Almost all patients were very satisfied with the service and most were prepared to see a nurse on a subsequent visit. We concluded that there are few differences between the performance of doctors and nurses in routine screening of asymptomatic patients.
ASP, The Art and Science of Practice: Elements of a Theory of the Practice of Operations Research: A Framework
Authors: Murphy Frederic H.
Published: April 2005

The ultimate value of operations research (OR) is making real differences in organizations. Yet little has been written on how one becomes good at doing OR and successful in practice. I propose a framework for understanding what makes good practice and an expert practitioner that encompasses the technical skills required to do OR through the managerial and marketing skills necessary to run an OR enterprise. The potential for success with OR methods depends on the nature of the problem, whether the initial and goal states are well defined or ill defined. The tools of artificial intelligence are useful for organizing the expertise in being a successful practitioner.
Editorial Notes
Authors: Sambamurthy Vallabh
Published: April 2005

This editorial describes the journal’s philosophy to encourage a diversity of submissions to Information Systems Research. While acknowledging the contributions of previous Editors-in-Chief, new initiatives are introduced. In particular, the journal encourages submission of research notes and will commission an annual special issue on a novel topic of significance to the information systems community. Editorial changes to the board are discussed and the incoming senior editors and associate editors are introduced.
A Production-Inventory System with Markovian Capacity and Outsourcing Option
Authors: Yang Jian , Qi Xiangtong , Xia Yusen
Published: April 2005

We study the optimal production-inventory-outsourcing policy for a firm with Markovian in-house production capacity that faces independent stochastic demand and has the option to outsource. We find very simple optimal policy forms under fairly reasonable assumptions. In addition, when the capacity Markov process is stochastically monotone, the policy parameters decrease in the firm’s current capacity level under additional assumptions. All these results extend to the infinite-horizon and undiscounted-cost cases. We analyze comparative statics and the necessity of some technical conditions, and discuss when the outsourcing option is more valuable.
Maximum Pressure Policies in Stochastic Processing Networks
Authors: Dai J. G. , Lin Wuqin
Published: April 2005

Complex systems like semiconductor wafer fabrication facilities (fabs), networks of data switches, and large-scale call centers all demand efficient resource allocation. Deterministic models like linear programs (LP) have been used for capacity planning at both the design and expansion stages of such systems. LP-based planning is critical in setting a medium range or long-term goal for many systems, but it does not translate into a day-to-day operational policy that must deal with discreteness of jobs and the randomness of the processing environment.

A stochastic processing network, advanced by J. Michael Harrison (2000, 2002, 2003), is a system that takes inputs of materials of various kinds and uses various processing resources to produce outputs of materials of various kinds. Such a network provides a powerful abstraction of a wide range of real-world systems. It provides high-fidelity stochastic models in diverse economic sectors including manufacturing, service, and information technology.

We propose a family of maximum pressure service policies for dynamically allocating service capacities in a stochastic processing network. Under a mild assumption on network structure, we prove that a network operating under a maximum pressure policy achieves maximum throughput predicted by LPs. These policies are semilocal in the sense that each server makes its decision based on the buffer content in its serviceable buffers and their immediately downstream buffers. In particular, their implementation does not use arrival rate information, which is difficult to collect in many applications. We also identify a class of networks for which the nonpreemptive, non-processor-splitting version of a maximum pressure policy is still throughput optimal. Applications to queueing networks with alternate routes and networks of data switches are presented.
A Continuous Model for Multistore Competitive Location
Authors: Dasci Abdullah , Laporte Gilbert
Published: April 2005

This paper presents a simple model to determine the location strategies of two retail firms planning to open a number of stores in a geographical market. Firms try to maximize their profit under a leader-follower type competition in which the number of stores is made endogenous by the introduction of fixed costs. A novel methodology is developed in which firms’ strategies are defined in terms of their location densities. This methodology leads to a model that is solvable analytically, and to several results on competitive location strategies. First, it is shown that if the follower decides to enter a market, he enters at least as strongly as the leader. Second, the leader can effectively deter entry even if she is severely cost-disadvantaged. However, in some cases the leader is better off by allowing the follower to enter the market. Third, the leader may also let the follower enter the market in some situations where she has a cost advantage. It is also shown that in situations where both firms enter the market, their location strategies are quite insensitive to model parameters.
Alterations in net glucose uptake and in the pancreatic B-cell GLUT2 transporter induced by diazoxide and by secretory stimuli
Authors: Zhao L , Li Z , Kullin M , Borg L A H , Karlsson F A
Published: April 2005

The pancreatic B-cell GLUT2 transporter and glucose metabolism were examined in isolated rat islets subjected to treatments affecting insulin secretion. Diazoxide was used to inhibit, while glipizide or depolarization of the plasma membrane with a high extracellular K+ concentration were used to stimulate insulin release in short-term experiments. Islet GLUT2 and insulin were determined by quantitative immunohistochemistry and GLUT2 was also determined by Western blot analysis. Islet net glucose uptake and glucose oxidation were measured using radioactively labelled glucose. Exposure of the islets to diazoxide was associated with a marked increase in the B-cell plasma membrane staining for GLUT2 and increased net glucose uptake. Glucose oxidation was not changed, which may reflect a lowered energy requirement. Conversely, islets subjected to a stimulated insulin secretion with glipizide or a high extracellular K+ concentration showed a reduced staining of the GLUT2 transporter. The net glucose uptake and glucose oxidation were also reduced. In islets exposed to the high K+ concentration no change in the molecular weight or phosphorylation of GLUT2 was observed but a lesser amount of the transporter was found by Western blot analysis. Thus, GLUT2 and glucose uptake in the pancreatic B-cell are modified by the secretory process, which suggests that changes in the glucose transporter have a functional role in normal B-cell physiology.
Suppression of experimental autoimmune encephalomyelitis using estrogen receptor-selective ligands
Authors: Elloso M Merle , Phiel Kristen , Henderson Ruth A , Harris Heather A , Adelman Steven J
Published: April 2005

Estrogens have been shown to modulate disease activity in experimental autoimmune encephalomyelitis (EAE), the mouse model for multiple sclerosis. Consistent with these findings, the severity of disease is reduced in pregnant women with multiple sclerosis when levels of estrogens are high. Estrogens bind to two known estrogen receptors (ER), ERα and ERβ. The relative contribution of these receptors to estrogen-mediated suppression of EAE was explored using ER-selective ligands. The ER antagonist ICI 182 780 reversed the suppressive effects of 17β-estradiol (E2), demonstrating that the protective effects of E2 on disease are dependent upon ER signaling. Treatment of SJL mice with the ERα-selective agonist proteolipid protein (PPT) prior to the induction of disease resulted in suppression of clinical symptoms of disease, whereas treatment with an ERβ-selective agonist (WAY-202041) had no effect. Treatment of mice with PLP peptide 139–151 (PPT) was also associated with decreased immune responses associated with disease. Consistent with its lack of effect on disease, the ERβ agonist had minimal effects on immune responses. The use of selective estrogen receptor modulators (SERMs) in this model was also explored, and we show that raloxifene and WAY-138923 were also effective in suppressing disease. These results demonstrate the beneficial effects of estrogen receptor ligands, in particular ERα-selective ligands, and may have implications in the development of therapeutic strategies for multiple sclerosis.
Surface metrology of engineering surfaces by means of the multi-pinhole technique
Authors: Brodmann R , Weber M
Published: April 2005

Surface metrology by means of optical principles is widely used in production and research of engineering surfaces and micro-electronics parts. This paper presents the latest development in confocal white-light microscopy with multi-pinhole technique. After a brief introduction and
discussion of the main features and benefits of this new confocal measurement system, the advantages and limits are described and compared with the well-established white-light interferometry technique. It can clearly be shown that, due to the physical filter technique with pinholes and the
use of large-aperture microscope objectives, the confocal method is superior for engineering surfaces with steep slopes. This is illustrated by comparing the results of measurements of the white-light confocal technique with white-light interferometry.
Amine Fluoride/Stannous Fluoride and Chlorhexidine Mouthwashes as Adjuncts to Single‐Stage Dental Implants: A Comparative Study
Authors: Horwitz Jacob , Machtei Eli E. , Zuabi Otman , Peled Micha
Published: April 2005

Background: The growing popularity of non‐submerged dental implants in recent years requires a greater emphasis on microbial plaque control. Chlorhexidine (CHX), the most commonly used mouthwash in implant surgery, is sometimes associated with tooth staining and alteration in taste perception. Amine fluoride/stannous fluoride (AmF/SnF2) mouthwash has been shown to have anti‐infective properties; however, it has not been tested as an adjunct anti‐infective means in non‐submerged dental implants. The purpose of this trial was to compare AmF/SnF2 and CHX mouthwashes as adjuncts to single‐stage dental implants.

Methods: Thirty‐three patients aged 34 to 79 (mean 54.30 ± 8.69 SD) requiring dental implants were accepted into the study. Following comprehensive periodontal therapy patients received one to three non‐submerged dental implants (maxilla: 17; mandible: 45; anterior: 3, posterior: 59). After surgery patients were given analgesics and antibiotics as well as 2,400 ml of coded mouthwash bottles previously randomized between the two above mentioned formulations. Clinical and radiographic parameters were recorded at baseline and 3 and 12 months post‐surgery.

Results: Twelve‐month survival rates were 100% and 92.9% for the AmF/SnF2 and CHX groups, respectively. Compliance was slightly higher in the AmF/SnF2 group (84.35% ± 3.39% versus 78.15% ± 4.59% SE) but statistically similar. There was no statistically significant difference between the AmF/SnF2 and CHX groups in staining index at 3 months (1.519 ± 0.22 versus 1.457 ± 0.24 SE) and patient subjective evaluation of the mouthwashes. Radiographic bone loss was 0.79 ± 0.23 and 1 ± 0.13 SE at 3 months and 1.06 ± 0.13 and 1.27 ± 0.25 at 12 months for the CHX and AmF/SnF2 groups, respectively; the difference was statistically insignificant (P = 0.388 and 0.504, respectively).

Conclusion: Both CHX and AmF/SnF2 mouthwashes can be used post‐surgically after one‐stage implant surgery. J Periodontol 2005;76: 334‐340.
An 8‐Year Retrospective Study: 1,100 Patients Receiving 1,557 Implants Using the Minimally Invasive Hydraulic Sinus Condensing Technique
Authors: Chen Leon , Cha Jennifer
Published: April 2005

Background: For many clinicians, inadequate alveolar bone height and anatomical features of the maxillary sinus complicate sinus lift procedures and placement of endosseous implants. We present a new internal crestal approach that addresses these issues.

Methods: Sinus burs and condensers of increasing width are used in conjunction with pliable atraumatic bone grafting mixture and hydraulic pressure from a surgical handpiece. The risk of a membrane perforation is minimized when the surgeon's tactile skill is administered in a two‐stage process to first loosen and then graft bone particulate under the Schneiderian membrane. Threaded implants can then be placed in the same visit and secured via primary closure.

Results: A retrospective investigation of 1,100 cases showed that eight implants failed and 14 required longer healing periods in patients with alveolar ridge heights varying between <1 to 5 mm.

Conclusions: Our experience suggests that hydraulic sinus condensing is a predictable and minimally invasive alternative for prosthetic rehabilitation of maxillary anterior and posterior regions in the presence of anatomical restrictions to implant placement. J Periodontol 2005;76:482‐491.
Microstructural and Nano‐Mechanical Characterisation of Multicomponent Composites Nanocrystalline Matrix
Authors: Woodcock T. G. , Alcalá G. , Mato S. , Gebert A. , Löser W. , Eckert J. , Schultz L.
Published: April 2005

Multicomponent, Ti‐based, in situ formed composites with a nanocrystalline matrix are a promising new type of material for structural applications. The materials exhibit an excellent combination of mechanical properties resulting from the composite microstructure. This paper contains a detailed introduction to such materials and a review of the most recent developments in the specific areas of microstructural and nano‐mechanical characterization.
Approaching Representative Volume Element size in Interpenetrating Phase Composites
Authors: Heggli M. , Etter T. , Wyss P. , Uggowitzer P. J. , Gusev A. A.
Published: April 2005

Based on the results of 3‐D X‐ray microtomography measurements, the authors built realistic computer models of graphite/aluminium interpenetrating composites and use them to investigate the representative volume element size for the effective electrical conductivity of such composites. Nonetheless, by averaging the numerical estimates obtained with computer models, one can obtain accurate estimates for the effective properties.
Cellular Ceramics in Metal Filtration
Authors: Olson R. A. , Martins L. C. B.
Published: April 2005

In most molten metal processing operations, the acts of melting, transporting and alloying the metal in preparation for casting into desired shapes introduces undesirable non‐metallic inclusions to the melt. Molten metals are highly reactive and tend to interact with gases and refractories during processing steps; undesirable phases are absorbed either as liquid or solid. Such examples of inclusion introduction are molten aluminum reacting with oxygen in air to form solid aluminum oxide, or molten cast iron reacting with oxygen in air to form liquid slag phases.
Konjugierte Oligomere mit terminaler Donor‐Acceptor‐Substitution
Authors: Meier Herbert
Published: April 2005

Konjugierte Oligomere sind in theoretischer, präparativer und materialwissenschaftlicher Hinsicht eine prominente Substanzklasse. Die Push‐pull‐Substitution durch einen Elektronendonor an einem Ende und einen Elektronenacceptor am anderen Ende verleiht den Verbindungen D‐π‐A besondere optische und elektronische Eigenschaften. Der vorliegende Aufsatz schildert die grundsätzlichen Strategien zur Synthese solcher Oligomerenreihen mit n Wiederholungseinheiten (n=1, 2, 3, 4, …︁) und die für ihre linearen und nichtlinearen optischen Eigenschaften (Absorption, Frequenzverdoppelung und ‐verdreifachung) geltenden Gesetzmäßigkeiten. Aus den chemischen, physikalischen und theoretischen Aspekten der push‐pull‐substituierten konjugierten Oligomere soll sich ein interdisziplinäres Bild dieser Verbindungsklasse zusammenfügen.
Molecular Organization and Signal Transduction at Intermembrane Junctions
Authors: Groves Jay T.
Published: April 2005

Surfaces create an environment in which multiple forces conspire together to yield a wealth of complex chemical processes. This is especially true of cell membranes, whose fluidity and flexibility enables responsive feedback with surface chemical interactions in ways not generally seen with inorganic materials. Spatial pattern formation of cell‐surface proteins at intermembrane junctions provides many beautiful examples of these phenomena, and is also emerging as a functional aspect of intercellular signaling. Correspondingly, the study of interactions of cell‐membrane surfaces is attracting significant attention from cell biologists and physical chemists alike. This convergence is fueled be recent, exquisite observations of protein pattern formation events within living immunological synapses along with parallel advances in membrane reconstitution, manipulation, and imaging technologies.
Polyoxometalate Monolayers in Langmuir–Blodgett Films
Authors: Clemente‐León Miguel , Coronado Eugenio , Gómez‐García Carlos J. , Mingotaud Christophe , Ravaine Serge , Romualdo‐Torres Gemma , Delhaès Pierre
Published: April 2005

Langmuir and Langmuir–Blodgett (LB) films of a variety of polyoxometalates of different shapes, sizes, and charges were prepared by taking advantage of the adsorption properties of these polyanions on a positively charged monolayer of an organic surfactant spread on water. Three different aspects were investigated. 1) The electrochemical and electrochromic properties of LB films containing the easily reducible polyoxoanion [P2Mo18O62]6−. Absorbance changes of these LB films deposited onto an ITO substrate have been induced by repeated switching of the applied potential. These changes are due to the formation of the colored reduced forms of the polyanion. Coloration and bleaching of the LB film occur very quickly and are reversible. 2) The preparation of LB films based on magnetic polyoxometalates, such as the Keggin anions, [CoW12O40]6− and [SiMn(OH2)W11O39]6−, or containing magnetic clusters of increasing nuclearities such as [Co4(H2O)2(PW9O34)2]10− and [Co4(H2O)2(P2W15O62)2]16− based on a Co4O16 ferromagnetic cluster, and the polyoxometalates [Co9(OH)3(H2O)6(HPO4)2(PW9O34)3]16− and [Ni9(OH)3(H2O)6(HPO4)2(PW9O34)3]16− based on a nonanuclear M9O36 cluster. 3) The preparation of LB films of the giant heteropolyoxomolybdate, [Na3(NH4)12][Mo57Fe6(NO)6O174(OH)3(H2O)24]⋅76 H2O.
Long distance selective fiber outgrowth of transplanted hNT neurons in white matter tracts of the adult rat brain
Authors: Baker K. Adam , Mendez Ivar
Published: April 2005

Terminally differentiated neurons derived from a human teratocarcinoma cell line (NT2N or hNT neurons) are promising as a cell source for transplantation, as they have been shown to be safe for transplantation in humans. We have shown previously that hNT neurons can express a catecholaminergic phenotype in a rat Parkinson model. In this study, we investigated the long‐term survival and ability of hNT neurons to express tyrosine hydroxylase and reconstruct the dopamine‐denervated nigrostriatal pathway. Hemiparkinsonian rats received grafts of 400,000 viable hNT neurons into each of the denervated striatum and substantia nigra. Robust hNT grafts were detected up to 24 weeks posttransplantation, although few cells expressed tyrosine hydroxylase. Many hNT fibers were often associated with ipsilateral and contralateral white matter tracts—corpus callosum, rostral migratory stream, optic tract, and external capsule. Fewer fibers were associated with the superior cerebellar peduncle, medial lemniscus, and nigrostriatal pathway. Axons also projected into the frontal cortex and extended parallel to the surface of the brain in the superficial cortical layers. These pathways were seen in all grafted animals, suggesting that specific guidance cues exist in the adult brain governing hNT fiber outgrowth. Injured adult axons and transplanted embryonic neuronal axons rarely extend for such distances in the adult nervous system. We propose that elucidating the factors promoting and guiding hNT axonal outgrowth could provide important clues to enhancing regeneration and target reinnervation in the adult brain, two factors of critical importance for cell restoration strategies aimed at brain repair. J. Comp. Neurol. 486:318–330, 2005. © 2005 Wiley‐Liss, Inc.
An Efficient Keim‐Type Catalyst Based on an Electron‐Poor P,O‐Chelate; Tuning the Selectivity of Ethylene Oligomerisation towards Short α‐Olefins
Authors: Kuhn Pierre , Sémeril David , Jeunesse Catherine , Matt Dominique , Lutz Pierre , Welter Richard
Published: April 2005

The tertiary phosphane Ph2P‐pzONa, in which the phosphorus atom is substituted by an electron‐withdrawing pyrazol‐onato unit, reacts with trans‐[NiPhCl(PPh3)2] to afford quan‐titatively trans‐P,P'‐[NiPh(Ph2P‐pzO)(PPh3)] (4), the first Keim‐type catalyst derived from an amide. In the absence of any cocatalyst, complex 4 converts ethylene in high selectivity and activity into α‐olefins. The product distribution is drastically shifted towards lower oligomers when compared to the outcome of the reaction carried out with the conventional SHOP catalyst. Thus, when operating at 1 bar, over 99 wt.‐% of the oligomers formed are C4–C16 oligomers. In ethylene‐free solvents, 4 was shown to slowly undergo reductive elimination to produce the stabilised phosphorus ylide Ph3P‐pzO (5). Both compounds (4 and 5) were characterised by single‐crystal X‐ray diffraction analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Luminescence from Lanthanide(3+) Ions in Solution (Eur. J. Inorg. Chem. 8/2005)
Authors: Dessing Anders
Published: April 2005

The cover picture shows the absorbance of incident UV light in the bipyridine chromophore of a polypyridyl complex of terbium(3+). Subsequent energy transfer to the metal centre results in a metal‐centred emission of VIS light. Topical aspects are presented in the Microreview by A. Døssing on p. 1425ff.
Toxic event detection by respirometry and adaptive principal components analysis
Authors: Le Bonté Sébastien , Potier Olivier , Pons Marie‐Noëlle
Published: April 2005

Two methods based on adaptive principal components analysis (APCA) are compared to extract, from primary measurements, information related to the changes of wastewater characteristics induced by variable weather conditions and/or to the presence of toxic substances. The primary measurements are activated sludge respiratory data obtained by short‐term experiments in an on‐line batch respirometer, combined with indirect information on soluble pollution (UV‐visible absorbance, turbidity, pH, etc.) and wastewater flow rate. The Benchmark Simulation Model 1 (BSM1), which simulates the functioning of a large wastewater treatment plant by activated sludge, has been used to obtain large data sets and to test the proposed APCA method, which has then been applied to real wastewater characteristics. Copyright © 2005 John Wiley & Sons, Ltd.
Glial nitric oxide and ischemia
Authors: Gibson Claire L. , Coughlan Teresa C. , Murphy Sean P.
Published: April 2005

One of the responses to cerebral ischemia is an increase in the production of nitric oxide, catalyzed by enzymes expressed in both resident and infiltrating cells. The nitric oxide that is generated does contribute to the ensuing pathology, but it can also be beneficial. The effects of nitric oxide depend on the cell site of production, the amount generated, and the chemical nature of the products of further oxidation. Understanding how nitric oxide production from microglia and astrocytes contributes to ischemic pathology is important for the development and application of future therapeutics based on inhibiting or amplifying its production in the injured brain. © 2005 Wiley‐Liss, Inc.
Astrocytes in cerebral ischemic injury: Morphological and general considerations
Authors: Panickar Kiran S. , Norenberg Michael D.
Published: April 2005

Asrocytic responses constitute one of the earliest and most prominent changes in the CNS following ischemic injury. Astrocytes are known to carry out critical functions such as maintenance of ionic homeostasis, prevention of excitotoxicity, scavenging free radicals, provision of nutrients and growth factors, promotion of neovascularization, and support of synaptogenesis and neurogenesis that potentially may influence the outcome of ischemic injury. This article reviews ischemia‐associated alterations in astrocytes and their potential significance. Interactions with neurons, microglia, and endothelial cells are also considered. This article highlights the critical role of astrocytes in the CNS response to ischemic injury. © 2005 Wiley‐Liss, Inc.
Role of glial cells in cerebral ischemia
Authors: Nedergaard Maiken , Dirnagl Ulrich
Published: April 2005

Despite intense efforts at the bench and at the bedside, few therapeutic strategies exist to combat the consequences of cerebral ischemia. Traditionally, a “neurocentric” view has dominated research in this field. Evidence is now accumulating that glial cells, in particular astrocytes, play an active and important role in the pathophysiology of cerebral ischemia. Brain energetics, water and ion homeostasis, inflammation, trophic factor production, vascular regulation, neuroneogenesis, and vasculogenesis, among others, are all under the control of glial cells. As a consequence, glial cells have been identified as promising targets for novel therapeutic approaches in brain protection. This review aims at dissecting possible protective as well as destructive roles of astrocytes (and other glial cells) in cerebral ischemia. By emphasizing open issues in this field, we hope to stimulate further research into this relatively unexplored aspect of brain pathophysiology. © 2005 Wiley‐Liss, Inc.
Targeted expression of anti‐apoptotic protein p35 in oligodendrocytes reduces delayed demyelination and functional impairment after spinal cord injury
Authors: Tamura Mutsuhiro , Nakamura Masaya , Ogawa Yuto , Toyama Yoshiaki , Miura Masayuki , Okano Hideyuki
Published: April 2005

Functional impairment after spinal cord injury (SCI) is attributed to neuronal cell necrosis death and axonotmesis, with further worsening caused by the accompanying apoptosis of myelin‐forming oligodendrocytes (OLGs). However, it is unclear as to how much OLG apoptosis contributes to functional impairment. To address this issue, we used transgenic mice characterized by the targeted expression of p35, a broad‐spectrum caspase inhibitor, in OLGs using the cre/loxP system (referred to as cre/p35 transgenic mice). In this study, we examined the motor function and histopathologic changes after a contusive thoracic spinal cord injury in the cre/p35 transgenic mice. A larger number of OLGs and a lesser extent of demyelination were observed after SCI in the cre/p35 transgenic mice than in the control cre mice, which did not carry the p35 transgene. Furthermore, the motor function of the hindlimbs recovered to a significantly better degree in the cre/p35 transgenic mice than in the control cre mice. Thus, the inhibition of OLG apoptosis decreased the extent of functional impairment after SCI. These findings suggest that the inhibition of OLG apoptosis may be a potential treatment for SCI. © 2005 Wiley‐Liss, Inc.
A new approach to neuroimaging with magnetoencephalography
Authors: Hillebrand Arjan , Singh Krish D. , Holliday Ian E. , Furlong Paul L. , Barnes Gareth R.
Published: April 2005

We discuss the application of beamforming techniques to the field of magnetoencephalography (MEG). We argue that beamformers have given us an insight into the dynamics of oscillatory changes across the cortex not explored previously with traditional analysis techniques that rely on averaged evoked responses. We review several experiments that have used beamformers, with special emphasis on those in which the results have been compared to those observed in functional magnetic resonance imaging (fMRI) and on those studying induced phenomena. We suggest that the success of the beamformer technique, despite the assumption that there are no linear interactions between the mesoscopic local field potentials across distinct cortical areas, may tell us something of the balance between functional integration and segregation in the human brain. What is more, MEG beamformer analysis facilitates the study of these complex interactions within cortical networks that are involved in both sensory‐motor and cognitive processes. Hum. Brain Mapp 25:199–211, 2005. © 2005 Wiley‐Liss, Inc.
Voxel‐based analysis of MRI detects abnormal visual cortex in children and adults with amblyopia
Authors: Mendola Janine D. , Conner Ian P. , Roy Anjali , Chan Suk‐Tak , Schwartz Terry L. , Odom J. Vernon , Kwong Kenneth K.
Published: April 2005

Amblyopia, sometimes called “lazy eye,” is a relatively common developmental visual disorder well characterized behaviorally; however, the neural substrates associated with amblyopia in humans remain unclear. We hypothesized that abnormalities in the cerebral cortex of subjects with amblyopia exist, possibly as a result of experience‐dependent neuronal plasticity. Anatomic magnetic resonance imaging (MRI) and psychophysical vision testing was carried out on 74 subjects divided into two age ranges, 7–12 years and 18–35 years, and three diagnoses, strabismic amblyopia, anisometropic amblyopia, and normal vision. We report a behavioral impairment in contrast sensitivity for subjects with amblyopia, consistent with previous reports. When the high‐resolution MRI brain images were analyzed quantitatively with optimized voxel‐based morphometry, results indicated that adults and children with amblyopia have decreased gray matter volume in visual cortical regions, including the calcarine sulcus, known to contain primary visual cortex. This finding was confirmed with a separate region‐of‐interest analysis. For the children with amblyopia, additional gray matter reductions in parietal‐occipital areas and ventral temporal cortex were detected, consistent with recent reports that amblyopia can result in spatial location and object processing deficits. These data are the first to provide possible neuroanatomic bases for the loss of binocularity and visual sensitivity in children and adults with amblyopia. Hum Brain Mapp 25:222–236, 2005. © 2005 Wiley‐Liss, Inc.