bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing a Scholarship Community
Authors: Cumbie Sharon , Weinert Clarann , Luparell Susan , Conley Virginia , Smith James
Published: August 2005

Purpose:

To report the results of a multidisciplinary, interinstitutional writing support group established to facilitate faculty scholarly productivity.

Organizing Concept:

The road to scholarship can be filled with many obstacles, among them time constraints, teaching and meeting demands, student needs, office interruptions, and lack of colleagueship. The problems associated with lack of colleagueship, in particular, can be compounded for faculty who work in isolated contexts with few, if any, senior faculty to serve as mentors.

Methods of Development:

The Western Writers Coercion Group evolved over a 2‐year period from a small group of nursing faculty at a single institution to include, by its second year, 21 faculty from five western university campuses and three academic disciplines. The group met biweekly via teleconference with the objectives of defining and accomplishing realistic individual scholarship goals and providing a forum for the critical exchange of ideas.

Results:

The ongoing support and mentoring of the group led to significant writing outcomes in the form of manuscripts submitted for publication, abstracts submitted for conference presentation, grant proposals developed, and collegial relationships formed.

Discussion:

Although the benefits of group participation varied somewhat for faculty at different points in the career trajectory, they seemed to accrue at all levels of development. Group members underscored the many less quantifiable advantages of group participation: exposure to broader professional perspectives, the formation of key professional relationships, the enrichment of multidisciplinary input, and individualized assistance with time management, goal setting, and actual drafts.

Conclusions:

The structure and experience of this group, which continues to meet regularly, might be a model to guide other groups of scholars who face geographic isolation and who struggle with balancing time and work and finding motivation for the process of writing.
Electrically Conductive CNT‐Dispersed Silicon Nitride Ceramics
Authors: Tatami Junichi , Katashima Tomofumi , Komeya Katsutoshi , Meguro Takeshi , Wakihara Toru
Published: August 2005

Carbon nanotube (CNT)‐dispersed Si3N4 ceramics with electrical conductivity were developed based on the lower temperature densification technique, in which the key point is the addition of both TiO2 and AlN as well as Y2O3 and Al2O3 as sintering aids. This new ceramic with a small amount of CNTs exhibits very high electrical conductivity in addition to high strength and toughness. Since Si3N4 ceramics with Y2O3–Al2O3–TiO2–AlN were originally used as a wear material, electrically conductive Si3N4 ceramics are expected to be applied for high‐performance static‐electricity‐free bearings for aerospace and other high‐performance components.
Phase Formation and Magnetoresistance of Double Perovskite Sr2FeMoO6
Authors: Li Chen , Cailei Yuan , Junmin Xue , Wang John
Published: August 2005

Phase formation behaviors of double perovskite Sr2FeMoO6 (SFMO) derived from mechanical activation were investigated. Polycrystalline double perovskite SFMO of grain sizes in nanometer range were synthesized by heat treatment of the precursors derived from mechanical activation of SrO, Fe2O3, and MoO3 at temperatures in the range of 600°–900°C in flowing atmosphere of H2/Ar. Mechanical activation at room temperature led to formation of SFMO at 700°C, which is about 200°C lower than what is required in the conventional solid state reaction. The magnetization of thus‐derived SFMO increases with increasing heat‐treatment temperature in the range of 700°–900°C. Similarly, its magnetoresistance ratio also increases with increasing heat‐treatment temperature, which is accounted for by the elimination of insulating SrMoO4 impurity phase and enhancement in crystallinity of the double perovskite SFMO phase.
A descriptive study on retrieved non‐threaded and threaded implant designs
Authors: Bolind Pia K. , Johansson Carina B. , Becker William , Langer Laureen , Sevetz Edward B. , Albrektsson Tomas O.
Published: August 2005

Objectives: In the light microscope compare the amount of bone saucerization for non‐threaded cylindrical and threaded implant designs in retrieved samples from patients.

Material and method: Consecutively received retrieved oral implants from 117 patients, whereof 85 non‐threaded cylindrical and 85 Brånemark implants, have been included in the study. For 75 non‐threaded cylindrical and 46 Brånemark implants was the entire implant length available for calculation. Undecalcified ground sections were investigated in the light microscope with calculation of percentage of implant length coronal to the first bone–implant contact and percentage of bone to implant contact.

Results: Mean value for implant length coronal to first bone–implant contact was 65%, standard error of the mean (SEM) 3 (range 0–100%), for non‐threaded cylindrical implants and 43%, SEM 6 (range 0–100%) for Brånemark implants. Mean values of bone contact along the entire implant length was 23%, SEM 2 (range 0–65%), for the non‐threaded cylindrical implants and 33%, SEM 5 (range 0–93%) for the Brånemark implants.

Conclusion: Within the limitations of this retrospective, retrieval study non‐threaded cylindrical implants demonstrated a greater bone saucerization when evaluated in the light microscope.
Three‐dimensional composites manufactured with human mesenchymal cambial layer precursor cells as an alternative for sinus floor augmentation: an in vitro study
Authors: Turhani Dritan , Watzinger Elisabeth , Weißenböck Martina , Yerit Kaan , Cvikl Barbara , Thurnher Dietmar , Ewers Rolf
Published: August 2005

Abstract: Bone tissue engineering is a promising approach for treatment of defective and lost bone in the maxillofacial region. Creating functional tissue for load bearing bone reconstruction using biocompatible and biodegradable scaffolds seeded with living cells is of crucial importance. The aim of our study was to compare the effects of poly‐lactic‐co‐glycolic acid (PLGA) and hydroxyapatite (HA) ceramic granulae on growth, differentiation, mineralization and gene expression of mandibular mesenchymal cambial layer precursor cells (MCLPCs) cultured onto tissue engineered three‐dimensional (3‐D) composites in vitro. These 3‐D composites were cultivated in a rotating cultivation system under osteogenic differentiation conditions for a maximum period of 21 days. After 6 and 21 days, histological examination was performed; scanning electron microscopy (SEM), alkaline phosphatase (ALP) activity and levels of DNA were investigated. Expression of bone‐specific genes osteocalcin, osteonectin, osteopontin, ALP, core binding factor α 1 and collagen type I were investigated by using a reverse transcription‐polymerase chain reaction (RT‐PCR) method. After 6 and 21 days of incubation an initiation of mineralization and the presence of newly formed bone at the surface of the composites were shown after evaluation of ALP activity, DNA content, SEM and histological staining. Expression of bone‐specific genes confirmed the bone‐like character of these composites and different effects of PLGA or HA granulae on the osteogenic differentiation of human MCLPCs in vitro. The results of this study support the concept that substrate signals significantly influence MCLPCs growth, differentiation, mineralization and gene expression in vitro, and that the use of these cells in the manufacturing of 3‐D cell/HA composites is a promising approach for load bearing bone reconstruction in the maxillofacial region in vivo.
Development of a Friction Component Model for Automotive Powertrain System Analysis and Shift Controller Design based on Parallel-Modulated Neural Networks
Authors: Cao M. , Wang K. W. , Fujii Y. , Tobler W. E.
Published: August 2005

In this study, a new hybrid-neural-network-based friction component model is developed for powertrain (PT) dynamic analysis and controller design. This new model, with significantly improved input-output scalability over conventional neural network configuration, has the capability to serve as a forward as well as an inverse system model. The structural information of the available physical and empirical correlations is utilized to construct a parallel-modulated neural network (PMNN) architecture consisting of small parallel sub-networks reflecting specific mechanisms of the friction component engagement process. The PMNN friction component model isolates the contribution of engagement pressure on engagement torque while identifying the nonlinear characteristics of the pressure-torque correlation. Furthermore, it provides a simple torque formula that is scalable with respect to engagement pressure. The network is successfully trained, tested and analyzed, first using analytical data at the component level and then using experimental data measured in a transmission system. The PMNN friction component model, together with a comprehensive powertrain model, is implemented to simulate the shifting process of an automatic transmission (AT) system under various operating conditions. Simulation results demonstrate that the PMNN model can be effectively applied as a part of powertrain system model to accurately predict transmission shift dynamics. A pressure-profiling scheme using a quadratic polynomial pressure-torque relationship of the PMNN model is developed for transmission shift controller design. The results illustrate that the proposed pressure profiling technique can be applied to a wide range of operating conditions. This study demonstrates the potential of the PMNN architecture as a new dynamic system-modeling concept: It not only outperforms the conventional network modeling techniques in accuracy and numerical efficiency, but also provides a new tool for transmission controller design to improve shift quality.
Compliance Control for an Anthropomorphic Robot with Elastic Joints: Theory and Experiments
Authors: Zollo Loredana , Siciliano Bruno , De Luca Alessandro , Guglielmelli Eugenio , Dario Paolo
Published: August 2005

Studies on motion control of robot manipulators with elastic joints are basically aimed at improving robot performance in tracking or regulation tasks. In the interaction between robots and environment, instead, the main objective of a control strategy should be the reduction of the vibrational and chattering phenomena that elasticity in the robot joints can cause. This work takes into account working environments where unexpected interactions are experienced and proposes a compliance control scheme in the Cartesian space to reduce the counter effects of elasticity. Two theoretical formulations of the control law are presented, which differ for the term of gravity compensation. For both of them the closed-loop equilibrium conditions are evaluated and asymptotic stability is proven through the direct Lyapunov method. The two control laws are applied to a particular class of elastic robot manipulators, i.e., cable-actuated robots, since their intrinsic mechanical compliance can be successfully utilized in applications of biomedical robotics and assistive robotics. A compared experimental analysis of the two formulations of compliance control is finally carried out in order to verify stability of the two closed-loop systems as well as the capability to control the robot force in the interaction.
Model Reduction of Large-Scale Discrete Plants With Specified Frequency Domain Balanced Structure
Authors: Zadegan Abbas H. , Zilouchian Ali
Published: August 2005

A new model reduction technique for linear time-invariant systems is proposed. A new method that reduces the order of large-scale systems by integrating singular perturbation with specified frequency domain balanced structure is proposed. Considering a frequency range at which the system actually operates guarantees a good approximation of the original full order model. Simulation experiments for model reduction of several large-scale systems demonstrate the effectiveness of the proposed technique.
Modeling and Control of a Wheel Loader With a Human-in-the-Loop Assessment Using Virtual Reality
Authors: Fales Roger , Spencer Erik , Chipperfield Kurt , Wagner Frank , Kelkar Atul
Published: August 2005

This paper presents dynamic modeling, controller design, and virtual reality (VR)-based human-in-the-loop real-time simulation for a wheel loader control system. In particular, a loader with electrohydraulic actuation is considered. A detailed nonlinear dynamic model is developed for the hydraulic system and the loader linkage. The hydraulic model includes a load sensing pump, valves, and cylinders. The linkage model represents a two degree of freedom loader with lift and tilt functions. A linear quadratic Gaussian based robust controller is designed for automatic bucket leveling to assist the operator by keeping the angle of the bucket leveled while the boom is in motion. The closed-loop control system design is tested with a nonlinear model in a real-time VR simulation. In the VR simulation, the operator interacts with the model using a joystick input. The loader linkage geometry is displayed to the operator in real time using a VR display. The controller performance was assessed in the VR environment. As expected, the controller was found to provide a significant improvement in the accuracy of the bucket leveling, particularly in the case of a novice operator controlling the linkage motion. While prototypes cannot be eliminated, the VR simulation combined with realistic physics and control dynamics provided a useful tool for evaluating hydraulic systems and controls with less reliance on prototype machines.
Using Steady Flow Force for Unstable Valve Design: Modeling and Experiments
Authors: Yuan Qinghui , Li Perry Y.
Published: August 2005

In single stage electrohydraulic valves, solenoid actuators are usually used to stroke the main spools directly. They are cheaper and more reliable than multistage valves. Their use, however, is restricted to low bandwidth and low flow rate applications due to the limitation of the solenoid actuators. Our research focuses on alleviating the need for large and expensive solenoids in single stage valves by advantageously using fluid flow forces. For example, in a previous paper, we proposed to improve spool agility by inducing unstable transient flow forces by the use of negative damping lengths. In the present paper, how steady flow forces can be manipulated to improve spool agility is examined through fundamental momentum analysis, CFD analysis, and experimental studies. Particularly, it is found that two often ignored components—viscosity effect and non-metering momentum flux, have strong influence on steady flow forces. For positive damping lengths, viscosity increases the steady flow force, whereas for negative damping lengths, viscosity has the tendency to reduce steady flow forces. Also, by slightly modifying the non-metering port geometry, the non-metering flux can also be manipulated to reduce steady flow force. Therefore, both transient and steady flow forces can be used to improve the agility of single stage electrohydraulic valves. Experimental results confirm the contributions of both transient and steady flow force in improving spool agility.
Cytotoxic Necrotizing Factor Type 1 Production by Uropathogenic
Escherichia coli
Modulates Polymorphonuclear Leukocyte Function
Authors: Davis Jon M. , Rasmussen Susan B. , O'Brien Alison D.
Published: August 2005

Many strains of uropathogenic
Escherichia coli
(UPEC) produce cytotoxic necrotizing factor type 1 (CNF1), a toxin that constitutively activates the Rho GTPases RhoA, Rac1, and Cdc42. We previously showed that CNF1 contributes to the virulence of UPEC in a mouse model of ascending urinary tract infection and a rat model of acute prostatitis and that a striking feature of the histopathology of the mouse bladders and rat prostates infected with CNF1-positive strains is an elevation in levels of polymorphonuclear leukocytes (PMNs). We also found that CNF1 synthesis leads to prolonged survival of UPEC in association with human neutrophils. Here, we tested the hypothesis that CNF1 production by UPEC diminishes the antimicrobial capacity of mouse PMNs by affecting phagocyte function through targeting Rho family GTPases that are critical to phagocytosis and the generation of reactive oxygen species. We found that, as with human neutrophils, CNF1 synthesis provided a survival advantage to UPEC incubated with mouse PMNs. We also observed that CNF1-positive UPEC down-regulated phagocytosis, altered the distribution of the complement receptor CR3 (CD11b/CD18), enhanced the intracellular respiratory burst, and increased levels of Rac2 activation in PMNs. From these results, we conclude that modulation of PMN function by CNF1 facilitates UPEC survival during the acute inflammatory response.
Sequence Variation and Immunologic Cross-Reactivity among
Babesia bovis
Merozoite Surface Antigen 1 Proteins from Vaccine Strains and Vaccine Breakthrough Isolates
Authors: LeRoith Tanya , Brayton Kelly A. , Molloy John B. , Bock Russell E. , Hines Stephen A. , Lew Ala E. , McElwain Terry F.
Published: August 2005

The
Babesia bovis
merozoite surface antigen 1 (MSA-1) is an immunodominant membrane glycoprotein that is the target of invasion-blocking antibodies. While antigenic variation has been demonstrated in MSA-1 among strains from distinct geographical areas, the extent of sequence variation within a region where it is endemic and the effect of variation on immunologic cross-reactivity have not been assessed. In this study, sequencing of MSA-1 from two Australian
B. bovis
vaccine strains and 14 breakthrough isolates from vaccinated animals demonstrated low sequence identity in the extracellular region of the molecule, ranging from 19.8 to 46.7% between the T vaccine strain and eight T vaccine breakthrough isolates, and from 18.7 to 99% between the K vaccine strain and six K vaccine breakthrough isolates. Although MSA-1 amino acid sequence varied substantially among strains, overall predicted regions of hydrophilicity and hydrophobicity in the extracellular domain were conserved in all strains examined, suggesting a conserved functional role for MSA-1 despite sequence polymorphism. Importantly, the antigenic variation created by sequence differences resulted in a lack of immunologic cross-reactivity among outbreak strains using sera from animals infected with the
B. bovis
vaccine strains. Additionally, sera from cattle hyperinfected with the Mexico strain of
B. bovis
and shown to be clinically immune did not cross-react with MSA-1 from any other isolate tested. The results indicate that isolates of
B. bovis
capable of evading vaccine-induced immunity contain an
msa-1
gene that is significantly different from the
msa-1
of the vaccine strain, and that the difference can result in a complete lack of cross-reactivity between MSA-1 from vaccine and breakthrough strains in immunized animals.
Calcineurin Is Required forCandida albicansTo Survive Calcium Stress in Serum
Authors: Blankenship Jill R. , Heitman Joseph
Published: August 2005

The calcium-activated protein phosphatase calcineurin plays a critical role in the virulence ofCandida albicans. Previous studies demonstrated that calcineurin is not required for the yeast-hypha dimorphic transition, host cell adherence, or host cell injury, which are all established virulence attributes of this organism. Calcineurin is, however, essential for survival in serum and disseminated infection. Here we identify the component of serum that is toxic to calcineurin mutant cells. Proteins, peptides, lipids, and other hydrophobic components were all excluded as essential toxic elements. Upon testing of small molecules present in serum, we discovered that calcineurin protects cells from stress caused by the endogenous levels of calcium ions present in serum. These studies illustrate how calcineurin functions in a calcium homeostatic pathway that enables a common human commensal to survive passage through the hostile environment of the bloodstream to establish deep-seated infections and cause disease.
Combined Conjugate Vaccines: Enhanced Immunogenicity with the N19 Polyepitope as a Carrier Protein
Authors: Baraldo Karin , Mori Elena , Bartoloni Antonella , Norelli Francesco , Grandi Guido , Rappuoli Rino , Finco Oretta , Del Giudice Giuseppe
Published: August 2005

The N19 polyepitope, consisting of a sequential string of universal human CD4+-T-cell epitopes, was tested as a carrier protein in a formulation of combined glycoconjugate vaccines containing the capsular polysaccharides (PSs) ofNeisseria meningitidisserogroups A, C, W-135, and Y. Good antibody responses to all four polysaccharides were induced by one single immunization of mice with N19-based conjugates. Two immunizations with N19 conjugates elicited anti-MenACWY antibody titers comparable to those induced after three doses of glycoconjugates containing CRM197 as carrier protein. Compared to cross-reacting material (CRM)-based constructs, lower amounts of N19-MenACWY conjugates still induced high bactericidal titers to all four PSs. Moreover, N19-MenACWY-conjugated constructs induced faster and higher antibody avidity maturation against meningococcal C PS than CRM-based conjugates. Very importantly, N19-specific antibodies did not cross-react with the parent protein from which N19 epitopes were derived, e.g., tetanus toxoid and influenza virus hemagglutinin. Finally, T helper epitopes of the N19 carrier protein were effectively generated both in vivo (after immunization with the N19 itself) and in vitro (after restimulation of epitope-specific spleen cells). Taken together, these data show that the N19 polyepitope represents a strong and valid option for the generation of improved or new combined glycoconjugate vaccines.
Characterization of Genetic and Phenotypic Diversity of Invasive Nontypeable
Haemophilus influenzae
Authors: Erwin Alice L. , Nelson Kevin L. , Mhlanga-Mutangadura Tendai , Bonthuis Paul J. , Geelhood Jennifer L. , Morlin Gregory , Unrath William C. T. , Campos Jose , Crook Derrick W. , Farley Monica M. , Henderson Frederick W. , Jacobs Richard F. , Mühlemann Kathrin , Satola Sarah W. , van Alphen Loek , Golomb Miriam , Smith Arnold L.
Published: August 2005

The ability of unencapsulated (nontypeable)
Haemophilus influenzae
(NTHi) to cause systemic disease in healthy children has been recognized only in the past decade. To determine the extent of similarity among invasive nontypeable isolates, we compared strain R2866 with 16 additional NTHi isolates from blood and spinal fluid, 17 nasopharyngeal or throat isolates from healthy children, and 19 isolates from middle ear aspirates. The strains were evaluated for the presence of several genetic loci that affect bacterial surface structures and for biochemical reactions that are known to differ among
H. influenzae
strains. Eight strains, including four blood isolates, shared several properties with R2866: they were biotype V (indole and ornithine decarboxylase positive, urease negative), contained sequence from the adhesin gene
hia
, and lacked a genetic island flanked by the
infA
and
ksgA
genes. Multilocus sequence typing showed that most biotype V isolates belonged to the same phylogenetic cluster as strain R2866. When present, the
infA-ksgA
island contains lipopolysaccharide biosynthetic genes, either
lic2B
and
lic2C
or homologs of the
losA
and
losB
genes described for
Haemophilus ducreyi
. The island was found in most nasopharyngeal and otitis isolates but was absent from 40% of invasive isolates. Overall, the 33
hmw
-negative isolates were much more likely than
hmw
-containing isolates to have tryptophanase, ornithine decarboxylase, or lysine decarboxylase activity or to contain the
hif
genes. We conclude (i) that invasive isolates are genetically and phenotypically diverse and (ii) that certain genetic loci of NTHi are frequently found in association among NTHi strains.
Characterization of the
dapA
-
nlpB
Genetic Locus Involved in Regulation of Swarming Motility, Cell Envelope Architecture, Hemolysin Production, and Cell Attachment Ability in
Serratia marcescens
Authors: Soo Po-Chi , Wei Jun-Rong , Horng Yu-Tze , Hsieh Shang-Chen , Ho Shen-Wu , Lai Hsin-Chih
Published: August 2005

Swarming migration of
Serratia marcescens
requires both flagellar motility and cellular differentiation and is a population-density-dependent behavior. While the
flhDC
and quorum-sensing systems have been characterized as important factors regulating
S. marcescens
swarming, the underlying molecular mechanisms are currently far from being understood.
Serratia
swarming is thermoregulated and is characterized by continuous surface migration on rich swarming agar surfaces at 30°C but not at 37°C. To further elucidate the mechanisms, identification of specific and conserved regulators that govern the initiation of swarming is essential. We performed transposon mutagenesis to screen for
S. marcescens
strain CH-1 mutants that swarmed at 37°C. Analysis of a “precocious-swarming” mutant revealed that the defect in a conserved

dapA
Sm

-nlpB
Sm

genetic locus which is closely related to the synthesis of bacterial cell wall peptidoglycan is responsible for the aberrant swarming phenotype. Further complementation and gene knockout studies showed that

nlpB
Sm

, which encodes a membrane lipoprotein, NlpB

Sm

, but not

dapA
Sm

, is specifically involved in swarming regulation. On the other hand,

dapA
Sm

but not

nlpB
Sm

is responsible for the determination of cell envelope architecture, regulation of hemolysin production, and cellular attachment capability. While the

nlpB
Sm

mutant showed similar cytotoxicity to its parent strain, the

dapA
Sm

mutant significantly increased in cytotoxicity. We present evidence that DapA

Sm

is involved in the determination of cell-envelope-associated phenotypes and that NlpB

Sm

is involved in the regulation of swarming motility.
Anti-LcrV Antibody Inhibits Delivery of Yops by
Yersinia pestis
KIM5 by Directly Promoting Phagocytosis
Authors: Cowan Clarissa , Philipovskiy Alexander V. , Wulff-Strobel Christine R. , Ye Zhan , Straley Susan C.
Published: August 2005

LcrV of
Yersinia pestis
is a major protective antigen proposed for inclusion in subunit plague vaccines. One way that anti-LcrV antibody is thought to protect is by inhibiting the delivery of toxins called Yops to host cells. The present study characterizes the relation between this inhibition and the phagocytosis of the bacteria. J774A.1 cells were infected with
Y. pestis
KIM5 in the presence of a protective polyclonal anti-LcrV antibody or a nonprotective polyclonal anti-YopM antibody, and delivery of YopH and YopE into the cytoplasm was assayed by immunoblotting. The ability to inhibit the delivery of these Yops depended upon having antibody bound to the cell surface; blocking conditions that prevented the binding of antibody to Fc receptors prevented the inhibition of Yop delivery. Anti-LcrV antibody also promoted phagocytosis of the yersiniae, whereas F(ab′)
2
fragments did not. Further, anti-LcrV antibody could not inhibit the delivery of Yops into cells that were unable to phagocytose due to the presence of cytochalasin D. However, Yops were produced only by extracellular yersiniae. We hypothesize that anti-LcrV antibody does not directly inhibit Yop delivery but instead causes phagocytosis, with consequent inhibition of Yop protein production in the intracellular yersiniae. The prophagocytic effect of anti-LcrV antibody extended to mouse polymorphonuclear neutrophils (PMNs) in vitro, and PMNs were shown to be critical for protection: when PMNs in mice were ablated, the mice lost all ability to be protected by anti-LcrV antibody.
Gene Expression Profile Analysis of
Porphyromonas gingivalis
during Invasion of Human Coronary Artery Endothelial Cells
Authors: Rodrigues Paulo H. , Progulske-Fox Ann
Published: August 2005

Microarrays were used to identify genes of
Porphyromonas gingivalis
W83 differentially expressed during invasion of primary human coronary artery endothelial cells. Analyses of microarray images indicated that 62 genes were differentially regulated. Of these, 11 genes were up-regulated and 51 were down-regulated. The differential expression of 16 selected genes was confirmed by real-time PCR.
Analysis of Cellular Phenotypes That Mediate Genetic Resistance to Tuberculosis Using a Radiation Bone Marrow Chimera Approach
Authors: Majorov Konstantin B. , Eruslanov Evgeny B. , Rubakova Elvira I. , Kondratieva Tatiana K. , Apt Alexander S.
Published: August 2005

Adoptive transfer of bone marrow cells from tuberculosis-resistant (I/St × A/Sn)F1donor mice into lethally irradiated susceptible I/St recipients changed their phenotype following infection with virulentMycobacterium tuberculosis. Compared to I/St→I/St control animals, F1→I/St chimeras demonstrated (i) prolonged survival time, (ii) increased antimycobacterial function of lung macrophages, (iii) elevated gamma interferon production by lung cells, and (iv) decreased infiltration of the lungs with CD4+and CD8+T cells and Ly-6G+neutrophils.
WHY LAW, ECONOMICS, AND ORGANIZATION?
Authors: Williamson Oliver E.
Published: August 2005

▪ Abstract  This review shows that a combined law, economics, and organization theory approach leads to different and deeper understandings of the purposes served by complex contract and economic organization. The business firm for these purposes is described not in technological terms (as a production function) but in organizational terms (as an alternative mode of governance). Firm and market are thus examined comparatively with respect to their capacities to organize transactions, which differ in their complexity, so as to economize on transaction costs. The predictive theory of economic organization that results has numerous ramifications for public policy toward business and for teaching and research in the law schools.
PKC and ERK are differentially involved in gonadotropin-releasing hormone-induced growth hormone gene expression in the goldfish pituitary
Authors: Klausen Christian , Tsuchiya Takeshi , Chang John P. , Habibi Hamid R.
Published: August 2005

Gonadotropin-releasing hormone (GnRH) is produced by the hypothalamus and stimulates the synthesis and secretion of gonadotropin hormones. In addition, GnRH also stimulates the production and secretion of growth hormone (GH) in some fish species and in humans with certain clinical disorders. In the goldfish pituitary, GH secretion and gene expression are regulated by two endogenous forms of GnRH known as salmon GnRH and chicken GnRH-II. It is well established that PKC mediates GnRH-stimulated GH secretion in the goldfish pituitary. In contrast, the signal transduction of GnRH-induced GH gene expression has not been elucidated in any model system. In this study, we demonstrate, for the first time, the presence of novel and atypical PKC isoforms in the pituitary of a fish. Moreover, our results indicate that conventional PKCα is present selectively in GH-producing cells. Treatment of primary cultures of dispersed goldfish pituitary cells with PKC activators (phorbol ester or diacylglycerol analog) did not affect basal or GnRH-induced GH mRNA levels, and two different inhibitors of PKC (calphostin C and GF109203X) did not reduce the effects of GnRH on GH gene expression. Together, these results suggest that, in contrast to secretion, conventional and novel PKCs are not involved in GnRH-stimulated increases in GH mRNA levels in the goldfish pituitary. Instead, PD98059 inhibited GnRH-induced GH gene expression, suggesting that the ERK signaling pathway is involved. The results presented here provide novel insights into the functional specificity of GnRH-induced signaling and the regulation of GH gene expression.
Effects of Different Titanium Alloys and Nanosize Surface Patterning on Adhesion, Differentiation, and Orientation of Osteoblast-Like Cells
Authors: Monsees Thomas K. , Barth K. , Tippelt S. , Heidel K. , Gorbunov A. , Pompe W. , Funk R.H.W.
Published: August 2005

To test nanosize surface patterning for application as implant material, a suitable titanium composition has to be found first. Therefore we investigated the effect of surface chemistry on attachment and differentiation of osteoblast-like cells on pure titanium prepared by pulsed laser deposition (TiPLD) and different Ti alloys (Ti6Al4V, TiNb30 and TiNb13Zr13). Early attachment (30 min) and alkaline phosphatase (ALP) activity (day 5) was found to be fastest and highest, respectively, in cells grown on TiPLD and Ti6Al4V. Osteoblasts seeded on TiPLD produced most osteopontin (day 10), whereas expression of this extracellular matrix protein was an order of magnitude lower on the TiNb30 surface. In contrast, expression of the corresponding receptor, CD44, was not influenced by surface chemistry. Thus, TiPLD was used for further experiments to explore the influence of surface nanostructures on osteoblast adhesion, differentiation and orientation. By laser-induced oxidation, we produced patterns of parallel Ti oxide lines with different widths (0.2–10 µm) and distances (2–20 and 1,000 µm), but a common height of only 12 nm. These structures did not influence ALP activity (days 5–9), but had a positive effect on cell alignment. Two days after plating, the majority of the focal contacts were placed on the oxide lines. The portion of larger focal adhesions bridging two lines was inversely related to the line distance (2–20 µm). In contrast, the portion of aligned cells did not depend on the line distance. On average, 43% of the cells orientated parallel towards the lines, whereas 34% orientated vertically. In the control pattern (1,000 µm line distance), cell distribution was completely at random. Because a significant surplus of the cells preferred a parallel alignment, the nanosize difference in height between Ti surface and oxide lines may be sufficient to orientate the cells by contact guiding. However, gradients in electrostatic potential and surface charge density at the Ti/Ti oxide interface may additionally influence focal contact formation and cell guidance.
A Morphometric Study of Age-Related Changes in Adult Human Epiglottis Using Quantitative Digital Analysis of Cartilage Calcification
Authors: Kano Mitsuhiro , Shimizu Yoshinaka , Okayama Keisuke , Igari Toshirou , Kikuchi Masayoshi
Published: August 2005

The epiglottis plays an important role in deglutition in humans. The present study investigated age-related changes in the epiglottis using macroscopic and microscopic measurements. Epiglottic specimens from 281 Japanese adult cadavers (177 males, 104 females) were obtained. Specimens were divided into three groups according to age: group I: 20–39 years old (32 males, 26 females), group II: 50–69 years old (82 males, 36 females), and group III: 80–98 years old (63 males, 42 females). Width, height, and thickness were measured macroscopically. To evaluate the degree of calcium deposition, the calcium volume in digitalized von Kossa-stained sections was assessed using a quantitative analysis. An elemental analysis of the area detected with von Kossa staining was done using energy-dispersive X-ray fluorescence spectrometer (EDX). Measurements of the thickness and cell density in the superficial and deep layers of epiglottic cartilage were performed in horizontal histological sections. No significant differences in macroscopic width or height were found across the age groups in either sex. A series of three measurements in males was significantly larger than in females (p < 0.05). The volume of the calcium deposit area was greater in males than in females (p < 0.05) and was significantly increased in group III in males (p < 0.05). The lower level of the epiglottic cartilage showed a greater calcium deposit area than the upper level. In the scanning image by line and surface analysis using EDX, the calcium deposit areas detected with von Kossa staining indicated a close association of calcium and phosphorus ions. The mean Ca/P molar ratio in the calcium deposit area was 1.32 ± 0.12. Microscopic cartilage thickness increased significantly with age (p < 0.05), and was greater in males than in females (p < 0.05). Cartilage cell density in the superficial cartilage layer was higher than in the deep layer and was decreased in group III (p < 0.05). Cartilage cell density was lower in males compared to females. Diameter of chondrocytes significantly increased in group III (p < 0.05) and was larger in males than in females in group III (p < 0.05). Epiglottic cartilage exhibited marked sex-related differences and progression of calcification with age. Calcification of epiglottic cartilage in elderly individuals may affect movement patterns in deglutition.
Parental Decision-Making after Ultrasound Diagnosis of a Serious Foetal Abnormality
Authors: Bijma Hilmar H. , Wildschut Hajo I.J. , van der Heide Agnes , Passchier Jan , Wladimiroff Juriy W. , van der Maas Paul J.
Published: August 2005

Objective: The purpose of this article is to provide clinicians who are involved in the field of foetal medicine with a comprehensive overview of theories that are relevant for the parental decision-making process after ultrasound diagnosis of a serious foetal abnormality. Methods: Since little data are available of parental decision-making after ultrasound diagnosis of foetal abnormality, we reviewed the literature on parental decision-making in genetic counselling of couples at increased genetic risk together with the literature on general decision-making theories. The findings were linked to the specific situation of parental decision-making after an ultrasound diagnosis of foetal abnormality. Results: Based on genetic counselling studies, several cognitive mechanisms play a role in parental decision-making regarding future pregnancies. Parents often havea binary perception of risk. Probabilistic information is translated into two options: the child will or will not be affected. The graduality of chance seems to be of little importance in this process. Instead, the focus shifts to the possible consequences for future family life. General decision-making theories often focus on rationality and coherence of the decision-making process. However, studies of both the influence of framing and the influence of stress indicate that emotional mechanisms can have an important and beneficial function in the decision-making process. Conclusion: Cognitive mechanisms that are elicited by emotions and that are not necessarily rational can have an important and beneficial function in parental decision-making after ultrasound diagnosis of a foetal abnormality. Consequently, the process of parental decision-making should not solely be assessed on the basis of its rationality, but also on the basis of the parental emotional outcome.
Increased C282Y Heterozygosity in Gestational Diabetes
Authors: Cauza Edmund , Hanusch-Enserer Ursula , Bischof Martin , Spak Marita , Kostner Karam , Tammaa Ayman , Dunky Attila , Ferenci Peter
Published: August 2005

Background: Hereditary hemochromatosis is an autosomal recessive disorder of iron metabolism that is characterized by excess accumulation of iron in various organs and often leads to diabetes mellitus (DM). To study whether mutations in the hemochromatosis gene (HFE) could be a risk factor for the development of gestational diabetes mellitus (GDM), the prevalence of HFE mutations in patients with GDM was compared to that of healthy pregnant controls. Methods: GDM was diagnosed in 208 of 2,421 pregnant woman screened between the 24th and 28thweek of gestation over a period of 18 months. Patients and 170 matched control subjects were screened for the HFE gene mutations C282Y and H63D. Results: In North and Central European GDM patients, the allele frequency of the C282Y mutation (7.7%) was higher than in pregnant controls (2.9%; p = 0.04), while the frequency of the H63D mutation was not different (p = 0.45). Three patients with GDM were homozygous for H63D (3.1%), 1 patient was homozygous for C282Y (1.0%), 2 patients were compound heterozygous (2.0%) and 26 were heterozygous [11 C282Y (11.2%) and 15 H63D (15.3%)]. C282Y and H63D allele frequencies were not different between controls and GDM patients of Southern European or non-European origin. Irrespective of the HFE-mutation status, serum ferritin levels were increased in patients with GDM compared to healthy pregnant controls (p = 0.01), while transferrin saturation was similar in both groups. Conclusions: In North and Central European patients with GDM, the C282Y allele frequency is higher than in healthy pregnant women, suggesting a genetic susceptibility to the development of GDM.
Ductus venosus Blood Flow Velocity Waveforms as a Predictor for Fetal Outcome in Isolated Congenital Heart Disease
Authors: Baez E. , Steinhard J. , Huber A. , Vetter M. , Hackelöer B.-J. , Hecher K.
Published: August 2005

Objective: To investigate whether pulsatility of ductus venosus (DV) flow velocity waveforms is of diagnostic value in predicting survival in fetuses with congenital heart disease (CHD). Methods: In a cross-sectional study, Doppler investigation of DV and umbilical artery blood flow was performed in 58 fetuses with isolated structural CHD, without other sonographically detectable structural or chromosomal abnormalities or tachyarrhythmia. The pulsatility index for veins of DV (DV-PIV) waveforms was expressed as multiples of the 95th centile (Mo95th) of the reference ranges for gestational age. The PIV was related to intrauterine and neonatal mortality within the first 6 months of life. Terminations of pregnancies and neonates with additional abnormalities detected after birth were excluded from statistical analysis. For statistical analysis, the different types of heart defects were separated into atrial and/or ventricular (AV) septal defects, right or left ventricular in- and outflow tract abnormalities and others. Results: After exclusion of 9 pregnancies (2 cases with failure of measurements of DV-PIV, 2 neonates with additional malformations, and 5 terminations of pregnancies), 49 cases were available for statistical analysis. The umbilical artery pulsatility index was within normal ranges in all but 1 case with AV canal and hydrops. In 7 pregnancies intrauterine fetal deaths occurred and 6 of them were hydropic. The median gestational age at birth for liveborn neonates was 39.0 weeks (range 27.8–41). There were 6 postnatal deaths, all but 1 within 28 days of delivery. The remaining fetuses survived for at least 6 months. The overall mortality rate was 27% (13/49). The DV-PIV was significantly higher in non-survivors than in survivors (median of Mo95th and interquartile ranges 1.48 (1.04–1.95) vs. 0.81 (0.70–1.15); p = 0.01). Analysis of subgroups showed significant differences for AV septal defects and abnormalities affecting predominantly the right ventricle (p = 0.046 and 0.043, respectively). Ten out of 13 non-survivors showed an abnormal DV-PIV (sensitivity 77%) as compared to 12 out of 36 survivors (specificity 67%). All hydropic fetuses (n = 6) showed an abnormal DV-PIV and ended in intrauterine deaths. Conclusions: Evaluation of the DV pulsatility is a useful additional variable for predicting the risk for mortality in fetuses with isolated structural CHD, in particular in fetuses with defects of the AV septum and with defects affecting predominantly right ventricular function. As there is no fetal hydrops without abnormal DV, this is another sign for the association of DV and cardiac failure.
Sudden Death because of Massive Pulmonary Thromboembolism and Concomitant Cerebrovascular Trophoblastic Embolism following Artificial Abortion
Authors: Habek Dubravko , Jančuljak Davor , Čerkez Habek Jasna , Jalšovec Dubravko
Published: August 2005

A rare case of sudden death due to cerebral embolization of trophoblastic tissue and concomitant massive pulmonary embolization following artificial abortion in a 42-year-old woman with poorly regulated hypertension and chronic smoking is described. Histopathological analysis showed syncytiotrophoblast cells, positive on hPL immunostaining, obstructing vascular lumina in the small perforating arteries irrigating the diencephalon. There was no trophoblast invasion of capillary walls. Severe perivascular edema and lymphocytic infiltration were observed. No trophoblastic cells were found in the pulmonary circulation.
Short Rib Polydactyly Syndrome Type 3 with Absence of Fibulae (Verma-Naumoff Syndrome)
Authors: Kumru Pınar , Aka Nurettin , Köse Gültekin , Vural Zeynep Tuzcular , Peker Önder , Kayserili Hülya
Published: August 2005

Short rib polydactyly syndrome (SRPS) is a group of skeletal dysplasias manifested by short-limb dwarfism, short ribs with thoracic dysplasia and polydactyly. SRPS is an inherited autosomal-recessive disorder with different prenatal sonographic and postnatal clinical, histological and radiologic findings. SRPS type 1 (Saldino-Noonan) and type 3 (Verma-Naumoff) are very similar and frequently get mixed. In this report, we present a case of SRPS with hydrops, thoracic hypoplasia, short limbs and postaxial polydactyly in a 27-week fetus. The visceral findings in the fetus including the central nervous system were normal. The karyotype was 46XY. The prenatal diagnosis was thought to be type 1 because of the absence of fibulae at ultrasonography. However, postmortem autopsy, histologic, and radiologic findings were reviewed and the diagnosis was type 3 SRPS because of absence of visceral anomalies, presence of fan-shaped iliac bones and short tubular bones with metaphyseal widening. We concluded that detailed ultrasonography performed in the prenatal period is very important in the diagnosis and differential diagnosis of SRPS.
Is Conservative Management of Prenatal and Neonatal Ovarian Cysts Justifiable?
Authors: Foley P.T. , Ford W.D.A. , McEwing R. , Furness M.
Published: August 2005

Objectives: To evaluate conservative management of fetal and neonatal ovarian cysts. Methods: We followed the progress of 11 fetal and 2 neonatal ovarian cysts. Results: Ten fetal cysts were simple at recognition, but 8 silently became complex by birth, with ovarian loss in 6/11 cases (54%). In 2 cases where large simple cysts presented for the first time at birth, serious complications occurred, resulting in the death of 1 newborn. Conclusions: If a fetal ovarian cyst is already complex before birth it can be managed conservatively, albeit with loss of the ipsilateral ovary in the majority of cases. As simple fetal ovarian cysts frequently become complex before birth, intervention may be justifiable to preserve the ovary. But any intervention also has the potential for complications, and may be ineffective. Intervention also requires accurate differentiation of ovarian cysts from other abdominal cysts.
Cisapride May Improve Feeding Tolerance of Preterm Infants: A Randomized Placebo-Controlled Trial
Authors: Kohl Martina , Wuerdemann Iris , Clemen Jessica , Iven Heiko , Katalinic Alexander , Moeller Jens C.
Published: August 2005

To evaluate the efficacy of cisapride in improving tolerance of enteral feeding, 59 premature infants were randomized into a blinded placebo-controlled study. Treatment was initiated with the introduction of enteral feeding and continued until 150 ml/kg/day of milk were tolerated. Only in extremely low birth weight (ELBW) infants, was the time to tolerate full enteral feeding shorter in the treatment group, whereas ECG recordings showed a significantly prolonged QTc interval during treatment. Two children developed cardiac rhythm disturbances. In conclusion premature infants may not benefit from routine use of the drug to improve enteral feeding, and seem to be more vulnerable to its side effects.