bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantification of Mycophenolic Acid and Glucuronide Metabolite in Human Serum by HPLC-Tandem Mass Spectrometry
Authors: Annesley Thomas M , Clayton Larry T
Published: March 2005

Background: The potent immunosuppressant mycophenolic acid (MPA) is metabolized to an inactive glucuronide (MPAG). The extent of metabolism varies among individuals, and the MPAG formed can be hydrolyzed to MPA and can displace MPA from serum albumin, creating a potential need to monitor both MPA and MPAG.

Methods: After addition of the carboxybutoxy ether of MPA (MPAC) as internal standard, MPA and MPAG were isolated from serum by acidification followed by solid-phase extraction. Gradient chromatographic separation was performed on a Waters Atlantis reversed-phase liquid chromatography (HPLC) column, and the compounds were quantified by electrospray ionization tandem mass spectrometry (MS/MS) in the multiple-reaction monitoring mode. Results obtained by HPLC-MS/MS were compared with an HPLC assay using ultraviolet detection (HPLC-UV) performed at a reference laboratory.

Results: MPAG, MPA, and MPAC were fully separated during a 7.0-min run time. Precision at both low and high concentrations of MPA ad MPAG met the suggested method validation criteria from a consensus panel report on MPA. The extraction efficiencies were 99% for MPA and MPAG. The assay was linear to 16 mg/L for MPA and 200 mg/L for MPAG. Limits of quantification were 0.1 mg/L for MPA and 1 mg/L for MPAG. Regression analysis gave the following results: HPLC-MS/MS = 1.03(HPLC-UV) − 0.03 mg/L (R2 = 0.982) for MPA; and HPLC-MS/MS = 0.93(HPLC-UV) + 0.89 mg/L (R2 = 0.967) for MPAG.

Conclusion: This HPLC-MS/MS assay can be used to reproducibly quantify MPA and MPAG across a large analytical range in serum from organ transplant patients.
Role of actin cytoskeleton in mammalian sperm capacitation and the acrosome reaction
Authors: Breitbart Haim , Cohen Gili , Rubinstein Sara
Published: March 2005

In order to fertilize, the mammalian spermatozoa should reside in the female reproductive tract for several hours, during which they undergo a series of biochemical modifications collectively called capacitation. Only capacitated sperm can undergo the acrosome reaction after binding to the egg zona pellucida, a process which enables sperm to penetrate into the egg and fertilize it. Polymerization of globular (G)-actin to filamentous (F)-actin occurs during capacitation, depending on protein kinase A activation, protein tyrosine phosphorylation, and phospholipase D activation. F-actin formation is important for the translocation of phospholipase C from the cytosol to the sperm plasma membrane during capacitation. Prior to the occurrence of the acrosome reaction, the F-actin should undergo depolymerization, a necessary process which enables the outer acrosomal membrane and the overlying plasma membrane to come into close proximity and fuse. The binding of the capacitated sperm to the zona pellucida induces a fast increase in sperm intracellular calcium, activation of actin severing proteins which break down the actin fibers, and allows the acrosome reaction to take place.
Serine protease activity, bovine sperm protease, 66 kDa (BSp66), is present in hamster sperm and is involved in sperm–zona interaction
Authors: Cesari A , Katunar M R , Monclus M A , Vincenti A , de Rosas J C , Fornés M W
Published: March 2005

Bovine sperm protease, 66 kDa (BSp66) is a serine protease previously characterized in bovine spermatozoa. Like other proteases, it may be present in sperm from other mammalian species different from bovine, playing a role in the fertilization process. In this study, we looked for BSp66 in hamster spermatozoa using heterologous antibodies against bovine BSp66. An immunoreactive protein was detected by Western blotting in mature and immature sperm. The detected protein had two isoforms similar to the ones reported in bovine sperm. Furthermore, indirect immune detection by fluorescence and electron microscopy assays, showed BSp66 signal at the acrosomal region similar to bovine sperm. As it was determined in bovine sperm, the acrosomal reaction displays the antigen within the acrosomal content. When live hamster sperm was incubated with polyclonal antibody against bovine BSp66 a decrease in the number of sperm bound to zona pellucida in homologous IVF and an impairment of head–head agglutination, were observed. These results suggest that a protease homologous to bovine BSp66 is present in golden hamster spermatozoa, with a conserved molecular mass and cellular location. Moreover, hamster BSp66 is probably involved in zona pellucida recognition.
Long-term effects of deslorelin implants on reproduction in the female tammar wallaby (Macropus eugenii)
Authors: Herbert C A , Trigg T E , Renfree M B , Shaw G , Eckery D C , Cooper D W
Published: March 2005

The contraceptive and endocrine effects of long-term treatment with implants containing the GnRH agonist deslorelin were investigated in female tammar wallabies (Macropus eugenii). Fertility was successfully inhibited for 515 ± 87 days after treatment with a 5 mg deslorelin implant (n= 7), while control animals gave birth to their first young 159 ± 47 days after placebo implant administration (n= 8). The duration of contraception was highly variable, ranging from 344 to 761 days. The strict reproductive seasonality in the tammar wallaby was maintained once the implant had expired. This inhibition of reproduction was associated with a significant reduction in basal LH concentrations and a cessation of oestrous cycles, as evidenced by low progesterone concentrations. There was evidence to suggest that some aspect of either blastocyst survival, luteal reactivation, pregnancy or birth may be affected by deslorelin treatment in some animals. These results show that long-term inhibition of fertility in the female tammar wallaby is possible using slow-release deslorelin implants. The effects of deslorelin treatment were fully reversible and there was no evidence of negative side effects. Slow-release GnRH agonist implants may represent a practicable method for reproductive management of captive and semi-wild populations of marsupials.
Endometrial tumor necrosis factor α (TNFα) is a likely mediator of early luteal phase mifepristone-mediated negative effector action on the preimplantation embryo
Authors: Lalitkumar PGL , Sengupta J , Ghosh D
Published: March 2005

Cytokines and growth factors are important mediators of progesterone-regulated endometrial receptivity and embryo development. Early luteal phase administration of a potent antiprogestin-like mifepristone to the rhesus monkey results in endometrial desynchrony, loss of embryo viability and implantation failure. In the present study, administration of mifepristone (2 mg/kg body weight, s.c.) on day 2 after ovulation resulted in a significant increase (P< 0.01) in the level of tumor necrosis factor α (TNFα) in glandular and vascular compartments of endometrium, and in endometrial secretion and luminal fluid on day 6 after ovulation in the rhesus monkey. There was an associated lag in embryonic development, characterized by delayed mitochondrial maturity, poorly developed junctional complexes, a relative absence of intra-cytoplasmic filaments and a high degree of intra-cellular degenerative features. Exposure of TNFα (0, 0.5, 5, 50 ng/ml) to preimplantation stage mouse embryosin vitroshowed a dose-dependent arrest in growth and development at both morula and blastocyst stages along with ultra-structural features of degeneration similar to those observed in embryos collected from early luteal phase mifepristone-treated monkeys. Thede novosynthesized and released proteins in terms of trichloroacetic acid precipitable35S by morulae and blastocystsin vitroshowed a marked depression following exposure to TNFα compared with control embryos. Based on the above observation and the fact that preimplantation stage embryos express receptors for TNFα, we suggest that increased levels of TNFα in endometrial and luminal compartments around the time of uterine receptivity following early luteal phase administration of mifepristone adversely affect the growth and viability of preimplantation stage embryos.
Membrane fluidity and the ability of domestic bird spermatozoa to survive cryopreservation
Authors: Blesbois E , Grasseau I , Seigneurin F
Published: March 2005

The ability to survive cryopreservation varies in spermatozoa from different bird species. Among the biological factors potentially responsible for such differences, species variations in membrane fluidity have a role in the restoration of the physiological state after freezing. Membrane fluidity may be assessed by measuring fluorescence polarization anisotropy with a fluorescent dye. Anistropy values are proportional to membrane rigidity and consequently inversely proportional to membrane fluidity. In the present study, polarization anisotropy of spermatozoa originating from species differing in the freezability of their semen (chicken, turkey and guinea fowl) was measured in addition to lipid composition (cholesterol/phospholipid ratio), sperm viability (membrane permeability to eosine) and morphological integrity before and after cryopreservation.

The percentages of viable and normal spermatozoa in fresh sperm were highest in the chicken (87%), lowest in guinea fowl (64%), and intermediate in turkeys (69%). Anisotropy values were highest in guinea fowl (0.205), lowest in chickens (0.155), and intermediate in turkeys (0.180). As a consequence, membrane fluidity was highest in chickens and lowest in guinea fowl. Cryopreservation significantly decreased sperm viability and morphological integrity and increased anisotropy in all species but did not change the inter species hierarchy. Initial cholesterol/phospholipid ratios were lower in chickens than in guinea fowl, and intermediate in turkeys (0.25, 0.26 and 0.29, respectively). Cryopreservation induced a severe decrease in cholesterol/phospholipid ratios in turkeys and guinea fowl.

Sperm membrane fluidity in chickens, turkeys and guinea fowl behaves as an indicator of sperm freezability in these species. Inter species differences for this parameter may be partly explained by differences in initial cholesterol/phospholipids content of spermatozoa. On the other hand, the rigidifying process induced by cryopreservation is not related to lipid damage by the same mechanisms.
Photoreduction of Ag+ in aluminoborate glasses induced by irradiation of a femtosecond laser
Authors: Hua Bin , Qiu Jianrong , Shimotsuma Yasuhiko , Fujita Koji , Hirao Kazuyuki
Published: March 2005

We report on photoreduction of Ag+ in aluminoborate glasses induced by irradiation of a femtosecond laser. Novel fluorescence was observed in the femtosecond laser irradiated glass when excited by a 365 nm ultraviolet lamp. Optical absorption, emission, and electron spin resonance spectra of the glass samples demonstrated that after the laser irradiation, portions of silver ions near the focused part of the laser beam inside the glass were reduced to silver atoms, which resulted in the formation of the characteristic fluorescence. The observed phenomenon may have promising applications in the fabrication of functional optical devices.
Monolithic nanocrystalline Au fabricated by the compaction of nanoscale foam
Authors: Hodge A.M. , Biener J. , Hsiung L.L. , Wang Y.M. , Hamza A.V. , Satcher J.H.
Published: March 2005

We describe a two-step dealloying/compaction process to produce nanocrystalline Au. First, nanocrystalline/nanoporous Au foam was synthesized by electrochemically driven dealloying. The resulting Au foams exhibited porosities of ∼60% with pore sizes of 40 and 100 nm and a typical grain size of <50 nm. Second, the nanoporous foams were fully compacted to produce nanocrystalline monolithic Au. The compacted Au was characterized by transmission electron microscopy and x-ray diffraction and tested by depth-sensing nanoindentation. The compacted nanocrystalline Au exhibited an average grain size of <50 nm and hardness values ranging from 1.4 to 2.0 GPa, which were up to 4.5 times higher than the hardness values obtained from polycrystalline Au.
Explosive shock processing of Pr2Fe14B/α–Fe exchange-coupled nanocomposite bulk magnets
Authors: Jin Z.Q. , Thadhani N.N. , McGill M. , Ding Y. , Wang Z.L. , Chen M. , Zeng H. , Chakka V.M. , Liu J.P.
Published: March 2005

Explosive shock compaction was used to consolidate powders obtained from melt-spun Pr2Fe14B/α–Fe nanocomposite ribbons, to produce fully dense cylindrical compacts of 17–41-mm diameter and 120-mm length. Characterization of the compacts revealed refinement of the nanocomposite structure, with approximately 15 nm uniformly sized grains. The compact produced at a shock pressure of approximately 1 GPa maintained a high coercivity, and its remanent magnetization and maximum energy product were measured to be 0.98 T and 142 kJ/m3, respectively. The compact produced at 4–7 GPa showed a decrease in magnetic properties while that made at 12 GPa showed a magnetic softening behavior. However, in both of these cases, a smooth hysteresis loop implying exchange coupling and a coercivity of 533 kA/m were fully recovered after heat treatment. The results illustrate that the explosive compaction followed by post-shock heat treatment can be used to fabricate exchange-coupled nanocomposite bulk magnets with optimized magnetic properties.
Silver-copper oxide based reactive air braze for joining yttria-stabilized zirconia
Authors: Kim J.Y. , Hardy J.S. , Weil K.S.
Published: March 2005

We investigated a new method of ceramic-to-metal joining, referred to as reactive air brazing, as a potential method of sealing ceramic components in high-temperature electrochemical devices. Sessile drop wetting experiments and joint strength testing were conducted using yttria stabilized zirconia (YSZ) substrates and CuO–Ag-based air brazes. Results from our studies indicate that the wettability of the braze improves substantially with increasing CuO content, over a compositional range of 1–8 mol% CuO, which is accompanied by an increase in the bend strength of the corresponding brazed YSZ joint. The addition of a small amount of TiO2(0.5 mol%) to the CuO–Ag braze further improves wettability due to the formation of a titanium zirconate reaction product along the braze/substrate interface. However, with one notable exception, the bend strength of these ternary braze joints remained nearly identical to those measured in comparable binary braze joints. Scanning electron microscopy analysis conducted on the corresponding fracture surfaces indicated that in the binary braze joints, failure occurs primarily at the braze/YSZ interface. Similarly in the case of the ternary, TiO2-doped brazes joint failure occurs predominantly along the interface between the braze filler metal and the underlying titanium zirconate reaction layer.
Fabrication of microchannel arrays in borophosphosilicate glass
Authors: Callender Claire L. , Ledderhof Christopher J. , Dumais Patrick , Blanchetière Chantal , Noad Julian P.
Published: March 2005

Two-dimensional arrays of embedded channels with cross-sectional diameters of 1–3 μm were fabricated in silica-on-silicon thin film structures. The channel arrays were fabricated using void-forming borophosphosilcate glass (BPSG) deposited by plasma-enhanced chemical vapor deposition (PECVD) over templates patterned and etched using standard photolithographic methods and reactive ion etching. The sizeand shape of the channels could be controlled by adjusting the depth, width, and spacing of the template ridges, the dopant levels in the BPSG, and the annealing conditions. Optimization of the channel fabrication process through detailed investigation of the process variables is presented. Potential applications inphotonics, sensors, and microfluidics are discussed.
Methods of Assessment of Cleft-Related Facial Deformity: A Review
Authors: Al-Omari I. , Millett D. T. , Ayoub A. F.
Published: March 2005

Objective

To review the stimulus media, measurements and scoring system, rater's characteristics, and facial region used in assessment of the appearance of cleft-related deformity.

Methods

A review of the literature was conducted using MedLine from January 1966 to June 2003. Key orthodontic journals and The Cleft Palate–Craniofacial Journal were hand searched as well.

Results

Most studies used a static two-dimensional means of assessment. Direct clinical assessment, three-dimensional media, or both have been used to a lesser extent. Only one study utilized all three assessment media. Three studies, however, attempted to compare the direct clinical assessment with that obtained using two-dimensional media. Most of the studies demonstrated that appearance of the cleft-related deformity could be measured by a variety of judges. The reliability and validity of the three different media as methods of assessment have received limited attention. The facial area assessed has varied from the full face, nasolabial area, or specific features of the lip or nose.

Conclusions

Wide variation exists in the study design related to assessment of cleft-related deformity. An internationally agreed objective method of assessment for this facial deformity is required. A three-dimensional, rather than a two-dimensional, means of assessment should be adopted.
Pacifier Sucking in a Child with Cleft Palate: Occlusal Consequences
Authors: Romero Martin , Bravo Luis A. , Romero Pilar
Published: March 2005

Objective

The case of a child with a repaired cleft palate and a pacifier habit is presented. The influence of both the cleft and the habit on the malocclusion is discussed. The malocclusion disappeared as the habit ceased.
Infant Orthopedics in UCLP: Effect on Feeding, Weight, and Length: A Randomized Clinical Trial (Dutchcleft)
Authors: Prahl Charlotte , Kuijpers-Jagtman Anne M. , Van't Hof Martin A. , Prahl-Andersen Birte
Published: March 2005

Objective

To study the effects of infant orthopedics (IO) on feeding, weight, and length.

Design

Prospective two-arm randomized controlled trial in three academic Cleft Palate Centers. Treatment allocation was concealed and performed by means of a computerized balanced allocation method.

Setting

Cleft Palate Centers of Amsterdam, Nijmegen, and Rotterdam, the Netherlands.

Patients

Infants with complete unilateral cleft lip and palate (UCLP), no other malformations.

Interventions

One group (IO+) wore passive maxillary plates during the first year of life, but the other group (IO−) did not. All other interventions were the same for both groups.

Main Outcome Measures

Bottle feeding velocity (mL/min) at intake, 3, 6, 15, and 24 weeks (T0 to T24); weight-for-age, length-for-age, and weight-for-length using z scores; reference values from the Netherlands’ third nationwide survey on growth.

Results

Feeding velocity increased with time from 2.9 to 13.2 mL/min in the IO− group and from 2.6 to 13.8 mL/min in the IO+ group; no significant differences were found between groups. Weight-for-age, length-for-age, and weight-for-length (z scores) did not differ significantly between groups, but overall the infants with unilateral cleft lip and palate in both groups had significantly lower mean z scores for weight-for-age and height-for-age than the reference during the first 14 months, and had lower mean values for weight-for-length after soft palate closure.

Conclusion

Infant orthopedics with the aim of improving feeding and consequent nutritional status in infants with unilateral cleft lip and palate can be abandoned.
Comparison of Plaster Casting with Three-Dimensional Cranial Imaging
Authors: Littlefield Timothy R. , Cherney Jennifer C. , Luisi Jerry N. , Beals Stephen P. , Kelly Kevin M. , Pomatto Jeanne K.
Published: March 2005

Objective

The development of a new cranial imaging system to capture a three-dimensional (3D) model of an infant's head has been previously reported. The accuracy of this new system has been independently established. However, before replacing the traditional plaster casting technique, the two methods require a comparison to ensure that the models they produce are equivalent.

Methods

Ten sequential infants were digitized by the 3D imaging system and the plaster casting technique following previously reported protocols. The cast models were also digitized so they could be compared with the digitized images. The two models (3dImage and Cast) were then imported into dimensional analysis software and aligned and registered with well-established registration algorithms. Difference maps that identified the variation between the two surfaces were generated for each pair, and descriptive statistics of these differences were recorded.

Results

The mean difference between the cast and the digitized models was 0.052 mm (standard deviation = 0.988), with a root mean square (RMS) difference of 1.028 mm. Two-dimensional slices obtained from the registered 3D surfaces demonstrated excellent agreement between the cranial contours.

Conclusions

In this investigation, the 3D models created by the new imaging system were found to be within 1.0 mm RMS of the models created by the plaster casting technique. Two-dimensional cranial contours demonstrated excellent agreement between the two methods. The results of this investigation confirmed that the new cranial imaging system and the traditional plaster casting technique yield equivalent models.
Neurons Derived From Human Mesenchymal Stem Cells Show Synaptic Transmission and Can Be Induced to Produce the Neurotransmitter Substance P by Interleukin-1α
Authors: Cho Kyung Jin , Trzaska Katarzyna A. , Greco Steven J. , McArdle Joseph , Wang Fu Shun , Ye Jiang-Hong , Rameshwar Pranela
Published: March 2005

Mesenchymal stem cells (MSCs) exhibit immune-suppressive properties, follow a pattern of multilineage differentiation, and exhibit transdifferentiation potential. Ease in expansion from adult bone marrow, as well as its separation from ethical issues, makes MSCs appealing for clinical application. MSCs treated with retinoic acid resulted in synaptic transmission, based on immunostaining of synaptophysin and electrophysiological studies. In situ hybridization indicated that the neurotransmitter gene preprotachykinin-I was expressed in these cells. However, translation of this gene only occurred after stimulation with interleukin (IL)-1α. This effect was blunted by costimulation with IL-1 receptor antagonist. This study reports on the ability of MSCs to be transdifferentiated into neurons with functional synapses with the potential to become polarized towards producing specific neurotransmitters.
Improvement of metabolic state in an animal model of nutrition-dependent type 2 diabetes following treatment with S 23521, a new glucagon-like peptide 1 (GLP-1) analogue
Authors: Üçkaya G , Delagrange P , Chavanieu A , Grassy G , Berthault M-F , Ktorza A , Cerasi E , Leibowitz G , Kaiser N
Published: March 2005

Glucagon-like peptide 1 (GLP-1) analogues are considered potential drugs for type 2 diabetes. We studied the effect of a novel GLP-1 analogue, S 23521 ([a8-des R36] GLP-1-[7–37]-NH2), on the metabolic state and β-cell function, proliferation and survival in the Psammomys obesus model of diet-induced type 2 diabetes. Animals with marked hyperglycaemia after 6 days of high-energy diet were given twice-daily s.c. injection of 100 μg/kg S 23521 for 15 days. Food intake was significantly decreased in S 23251-treated P. obesus; however, there was no significant difference in body weight from controls. Progressive worsening of hyperglycaemia was noted in controls, as opposed to maintenance of pre-treatment glucose levels in the S 23521 group. Prevention of diabetes progression was associated with reduced mortality. In addition, the treated group had higher serum insulin, insulinogenic index and leptin, whereas plasma triglyceride and non-esterified fatty acid levels were decreased. S 23521 had pronounced effect on pancreatic insulin, which was 5-fold higher than the markedly depleted insulin reserve of control animals. Immunohistochemical analysis showed islet degranulation with disrupted morphology in untreated animals, whereas islets from S 23521-treated animals appeared intact and filled with insulin; β-cell apoptosis was approximately 70% reduced, without a change in β-cell proliferation. S 23521 treatment resulted in a 2-fold increase in relative β-cell volume. Overall, S 23521 prevented the progression of diabetes in P. obesus with marked improvement of the metabolic profile, including increased pancreatic insulin reserve, β-cell viability and mass. These effects are probably due to actions of S 23521 both directly on islets and via reduced food intake, and emphasize the feasibility of preventing blood glucose deterioration over time in type 2 diabetes.
Control of adipose tissue lipid metabolism by tumor necrosis factor-α in rainbow trout (Oncorhynchus mykiss)
Authors: Albalat A , Liarte C , MacKenzie S , Tort L , Planas J V , Navarro I
Published: March 2005

Tumor necrosis factor-α (TNFα) is a cytokine with multiple biological functions which, in mammals, has been shown to modulate muscle and adipose tissue metabolism. In fish, TNFα has been identified in several species. However, few studies have examined the role of TNFα in fish outside the immune system. In this study, we assessed the effects of human recombinant TNFα and conditioned media from rainbow trout lipopolysaccharide (LPS)-stimulated macrophages (LPS-MCM) on lipolysis in isolated rainbow trout adipocytes. Furthermore, we studied the effects of an LPS injection in vivo on lipid metabolism. In our study, human recombinant TNFα stimulated lipolysis in trout adipocytes in a time- and dose-dependent manner. Similarly, LPS-MCM stimulated lipolysis in trout adipocytes when compared with control conditioned medium. Experiments using specific inhibitors of the MAP kinase pathway showed that p44/42 and p38 are partially involved in the lipolytic effects of TNFα. On the other hand, adipocytes from LPS-injected rainbow trout showed higher basal lipolysis than adipocytes from control fish after 24 h, while this effect was not seen at 72 h. Furthermore, lipoprotein lipase (LPL) activity in adipose tissue of LPS-injected fish was lower than in the controls at 24 h. These data suggest that TNFα plays an important role in the control of lipid metabolism in rainbow trout by stimulating lipolysis in vitro and in vivo and by down-regulating LPL activity of adipose tissue in vivo.
Hypothalamic responses to peripheral glucose infusion in food-restricted sheep are influenced by photoperiod
Authors: Archer Z A , Rhind S M , Findlay P A , Kyle C E , Barber M C , Adam C L
Published: March 2005

Nutritional feedback provided by systemic hormones, such as insulin and leptin, influences reproductive neuroendocrine output within the hypothalamus, yet the mechanisms and their interaction with photoperiodic cues remain unresolved in seasonal species. Here, peripheral glucose (G) infusion was used to increase endogenous concentrations of insulin and leptin in food-restricted sheep kept in either long-day (LD) or short-day (SD) photoperiod, and responses were examined in terms of pulsatile luteinising hormone (LH) (gonadotrophin-releasing hormone by inference) output and hypothalamic gene expression for nutritionally sensitive neuropeptides and receptors. We addressed the hypothesis that these hypothalamic responses were correlated and influenced by photoperiod. Oestradiol-implanted, castrated male sheep were kept 16 weeks in SD (8 h light/day) or LD (16 h light/day) and then transferred to the opposite photoperiods for 8 weeks, during which food was restricted to 90% requirement to maintain body weight (maintenance). For the final 6 days, food was reduced to 75% maintenance, and sheep in both photoperiods were infused intravenously with G (60 mM/h) or saline (S) (n=8/group). G-infused sheep had higher mean plasma concentrations of G, insulin and leptin than S-infused sheep, with no effect of photoperiod. In LD, but not in SD, G infusion increased LH pulse frequency and pulse amplitude. In LD, but not in SD, gene expression in the hypothalamic arcuate nucleus was lower in G- than S-infused sheep for neuropeptide Y (NPY) and agouti-related peptide (AGRP) and was higher in G- than S-infused sheep for pro-opiomelanocortin (POMC). Gene expression for leptin and insulin receptors was not affected by photoperiod or infusion. These results are consistent with the involvement of NPY, AGRP and POMC in mediating the reproductive neuroendocrine response to increased systemic nutritional feedback, and they support the hypothesis that hypothalamic responses to nutritional feedback are influenced by photoperiod in sheep.
Finite‐element modeling of the anthropoid mandible: The effects of altered boundary conditions
Authors: Marinescu Ruxandra , Daegling David J. , Rapoff Andrew J.
Published: March 2005

Finite‐element modeling provides a full‐field method for describing the stress environment of the skull. The utility of finite‐element models, however, remains uncertain given our ignorance of whether such models validly portray states of stress and strain. For example, the effects of boundary conditions that are chosen to represent the mechanical environment in vivo are largely unknown. We conducted an in vitro strain gauge experiment on a fresh, fully dentate adult mandible of Macaca fascicularis to model a simplified loading regime by finite‐element analysis for purposes of model validation. Under various conditions of material and structural complexity, we constructed dentate and edentulous models to measure the effects of changing boundary conditions (force orientation and nodal constraints) on strain values predicted at the gauge location. Our results offer a prospective assessment of the difficulties encountered when attempting to validate finite‐element models from in vivo strain data. Small errors in the direction of load application produce significant changes in predicted strains. An isotropic model, although convenient, shows poor agreement with experimental strains, while a heterogeneous orthotropic model predicts strains that are more congruent with these data. Most significantly, we find that an edentulous model performs better than a dentate one in recreating the experimental strains. While this result is undoubtedly tied to our failure to model the periodontal ligament, we interpret the finding to mean that in the absence of occlusal loads, teeth within alveoli do not contribute significantly to the structural stiffness of the mandible. © 2005 Wiley‐Liss, Inc.
Using finite‐element analysis to investigate suture morphology: A case study using large carnivorous dinosaurs
Authors: Rayfield Emily J.
Published: March 2005

Finite‐element analysis (FEA) can be used to investigate the mechanical significance of sutures and regions of intracranial flexibility in skulls. By modeling the stress response to feeding forces in a finite‐element skull model (with appropriate boundary conditions), one can compare the axis of distortion and orientation of stress and strain in the model to the degree of movement at actual sutural contacts in the real skull. Hypotheses detailing the effect of introducing patency or flexibility on mechanical performance can be constructed and subsequently tested. In this study, the correlation between stress environment, cranial strength, and sutural morphology and mobility is investigated in the cranium of the large theropod dinosaurAllosaurus fragilis. Theropods are an especially interesting model system as their skulls were massive (over 100 cm in some cases), may have generated extremely large bite forces, yet patent sutures persisted between many of the facial bones. In this analysis, it was discovered thatAllosauruscranial sutures appear generally capable of accommodating stress and strain patterns generated during biting. This study highlights the potential of FEA in devising and testing hypotheses of form and function and argues that useful information can be obtained from finite‐element models of extinct animals, providing that adequate assumptions are made and appropriate questions asked. © 2005 Wiley‐Liss, Inc.
Mechanical behavior and quantitative morphology of the equine laminar junction
Authors: Thomason Jeffrey J. , McClinchey Heather L. , Faramarzi Babak , Jofriet Jan C.
Published: March 2005

The horse's hoof is structurally modified for its mechanical functions, but studying the functional design of internal structures is hampered by the external keratinous capsule. Finite‐element analysis offers one method for evaluating mechanical function of components within the capsule, such as the laminar junction. This is the epidermodermal connection that binds the hoof wall strongly to the distal phalanx. Primary epidermal laminae (PEL), projecting inward from the wall, vary in morphology and are remodeled despite being keratinous. The aim of this study is to investigate the suggestion that remodeling of PEL is influenced by mechanical stress. Circumferential and proximodistal stress distribution and relative displacement in the laminar junction are assessed by finite‐element analysis (FEA) of nine hoof models. Spacing, orientation, and curvature of PEL are assessed from sections through 47 other hooves and compared with the stress and displacement data. Significant correlations are found between laminar spacing and seven displacement and stress variables, supporting the link between stresses and remodeling. Differences in external hoof shape cause regional variation in stress magnitudes around the laminar junction. This finding is in accord with previous observations that laminar morphology is individually regionally variable. This work provides the first concrete link between mechanical behavior and laminar morphology. © 2005 Wiley‐Liss, Inc.
Finite‐element model construction for the virtual synthesis of the skulls in vertebrates: Case study of Diplodocus
Authors: Witzel Ulrich , Preuschoft Holger
Published: March 2005

The measurement of strains in real skulls is an inductive method that yields information about the stresses occurring in the a priori existing shape. In contrast, the approach taken here to determine the relationship between skull function and skull shape applies Wolff's law through a deductive technique of structure synthesis. This article describes the application of this method in the exact virtual synthesis of a sauropod skull, e.g., Diplodocus longus Marsh from Wyoming. An unspecific homogeneous solid is first constructed, giving the stresses ample volume to spread between points of force application and constraint. ANSYS 7.0 is used to form 10‐noded tetrahedral finite elements with a maximum of 130,000 nodes. The initial conditions are the functional spaces for the eye openings, muscle forces, and the placement of the dental arcade, including assumed bite forces. Enforcing equilibrium of forces, the primary 3D stress flows in each load case are summarized by a physiological superposition, which accumulates the highest value of stress in each finite element. If the stress free parts are eliminated and the summarized stress flows are maintained, a reduced model appears, which is very similar to the real skull. This reduction of shape can be repeated iteratively and leads to a more exact form. Changes in the form of the dental arcade, its position relative to the braincase, the origins of muscles, or the height of the face lead to models that clearly resemble morphological differences between genera. The synthesis of a skull in this way demonstrates the direct correlation between functional loading and the biological structure and shape and can be used to test hypotheses regarding the relationship between structure and function during skull evolution. © 2005 Wiley‐Liss, Inc.
Rosiglitazone induces interleukin‐1 receptor antagonist in interleukin‐1β–stimulated rat synovial fibroblasts via a peroxisome proliferator–activated receptor β/δ–dependent mechanism
Authors: Moulin David , Bianchi Arnaud , Boyault Sandrine , Sebillaud Sylvie , Koufany Meriem , Francois Mathias , Netter Patrick , Jouzeau Jean‐Yves , Terlain Bernard
Published: March 2005

Objective

To study the potency of 2 peroxisome proliferator–activated receptor γ (PPARγ) agonists, 15‐deoxy‐Δ12,14‐prostaglandin J2 (15‐deoxy‐PGJ2) and rosiglitazone, to modulate the expression of interleukin‐1 receptor antagonist (IL‐1Ra) in rat synovial fibroblasts.

Methods

Levels of messenger RNA for IL‐1Ra and PPAR isotypes (α, β/δ, γ) were assessed by real‐time polymerase chain reaction in rat synovial fibroblasts exposed to 10 ng/ml of IL‐1β. PPAR levels were assessed by Western blotting and secreted IL‐1Ra levels by immunoassay. The potency of PPARγ agonists and the PPARβ/δ agonist GW‐501516 on IL‐1Ra levels was tested in the range of 1–10 μM and at 100 pM, respectively. The contribution of PPARγ to the effects of rosiglitazone on IL‐1Ra secretion was examined either by its overexpression or by inhibition using wild‐type or dominant‐negative constructs and the antagonist GW‐9662 (10 μM), respectively. The dominant‐negative strategy was also performed to investigate the possible contribution of PPARβ/δ and NF‐κB activation.

Results

IL‐1β–induced IL‐1Ra production was increased by 10 μM rosiglitazone but was reduced dose‐dependently by 15‐deoxy‐PGJ2. Both agonists lowered IL‐1β secretion, but rosiglitazone alone reduced the imbalance of IL‐1β/IL‐1Ra toward basal levels. Enhancement of IL‐1β–induced IL‐1Ra production by rosiglitazone was not affected by PPARγ overexpression or by its inhibition with dominant‐negative PPARγ or GW‐9662. Inhibition of NF‐κB was also ineffective against rosiglitazone but abolished the stimulating effect of IL‐1β on IL‐1Ra. All PPAR isotypes were expressed constitutively in rat synoviocytes, but PPARγ decreased dramatically upon IL‐1β exposure, whereas PPARβ/δ remained stable. Dominant‐negative PPARβ/δ abolished the enhancement of IL‐1Ra by rosiglitazone, whereas GW‐501516 reproduced the effect of rosiglitazone on IL‐1Ra secretion.

Conclusion

Rosiglitazone stimulates IL‐1Ra production by a PPARβ/δ mechanism in activated rat synovial fibroblasts, further contributing to its potential antiarthritic properties and opening new perspectives for the modulation of inflammatory genes by specific PPAR agonists in articular cells.
Classification analysis of the transcriptosome of nonlesional cultured dermal fibroblasts from systemic sclerosis patients with early disease
Authors: Tan Filemon K. , Hildebrand Bernard August , Lester Malisa S. , Stivers David N. , Pounds Stanley , Zhou Xiaodong , Wallis Debra D. , Milewicz Dianna M. , Reveille John D. , Mayes Maureen D. , Jin Li , Arnett Frank C.
Published: March 2005

Objective

To compare the transcriptosome of early‐passage nonlesional dermal fibroblasts from systemic sclerosis (SSc) patients with diffuse disease and matched normal controls in order to gain further understanding of the gene activation patterns that occur in early disease.

Methods

Total RNA was isolated from early‐passage fibroblasts obtained from nonlesional skin biopsy specimens from 21 patients with diffuse SSc (disease duration <5 years in all but 1) and 18 healthy controls who were matched to the cases by age (±5 years), sex, and race. Array experiments were performed on a 16,659‐oligonucleotide microarray utilizing a reference experimental design. Supervised methods were used to select differentially expressed genes. Quantitative polymerase chain reaction (PCR) was used to independently validate the array results.

Results

Of the 8,324 genes that passed filtering criteria, classification analysis revealed that <5% were differentially expressed between SSc and normal fibroblasts. Individually, differentially expressed genes included COL7A1, COL18A1 (endostatin), DAF, COMP, and VEGFB. Using the panel of genes discovered through classification analysis, a set of model predictors that achieved reasonably high predictive accuracy was developed. Analysis of 1,297 gene ontology (GO) classes revealed 35 classes that were significantly dysregulated in SSc fibroblasts. These GO classes included anchoring collagen (30934), extracellular matrix structural constituent (5201), and complement activation (6958, 6956). Validation by quantitative PCR demonstrated that 7 of 7 genes selected were concordant with the array results.

Conclusion

Fibroblasts cultured from nonlesional skin of patients with SSc already have detectable abnormalities in a variety of genes and cellular processes, including those involved in extracellular matrix formation, fibrillogenesis, complement activation, and angiogenesis.
Erythropoietin reduces the degree of arthritis caused by type II collagen in the mouse
Authors: Cuzzocrea Salvatore , Mazzon Emanuela , di Paola Rosanna , Genovese Tiziana , Patel Nimesh S. A. , Britti Domenico , de Majo Massimo , Caputi Achille P. , Thiemermann Christoph
Published: March 2005

Objective

Erythropoietin (EPO) is a potent stimulator of erythroid progenitor cells, and its expression is enhanced by hypoxia. The aim of this study was to investigate the effect of EPO on collagen‐induced arthritis (CIA) in the mouse.

Methods

CIA was induced by intradermal injection of bovine type II collagen (CII) and Freund's complete adjuvant. Starting on day 25, some of the mice with CIA received daily subcutaneous injections of EPO (1,000 units/kg). Two other groups of mice received sham treatment alone or sham treatment followed by EPO treatment, respectively. Arthritis was assessed clinically, radiologically, and histologically. Cytokine and chemokine levels were measured, and neutrophil infiltration into inflamed joints was quantitated. Immunohistochemistry studies were performed to measure protein nitrosylation. Chondrocyte apoptosis was assessed by TUNEL assay.

Results

Macroscopic clinical evidence of CIA first appeared as periarticular erythema and edema in the hind paws. The incidence of CIA was 100% by day 27 in the CII‐challenged mice, and the severity of CIA progressed over a 35‐day period, with radiographic evaluation revealing focal resorption of bone. Histopathologic features of CIA included erosion of the cartilage at the joint margins. Treatment with EPO starting at the onset of arthritis (day 25) ameliorated the clinical signs on days 26–35 and improved histologic status in the joints and paws. The degree of oxidative and nitrosative damage was significantly reduced in EPO‐treated mice as indicated by decreased nitrotyrosine formation and poly(ADP‐ribose) polymerase activation. Plasma levels of the proinflammatory cytokine tumor necrosis factor α were also significantly reduced by EPO treatment. In addition, EPO reduced the levels of apoptosis in chondrocytes in articular cartilage, as indicated by decreased TUNEL staining.

Conclusion

These findings demonstrate that EPO exerts an antiinflammatory effect during chronic inflammation and is able to ameliorate the tissue damage associated with CIA.
Febuxostat, a novel nonpurine selective inhibitor of xanthine oxidase: A twenty‐eight–day, multicenter, phase II, randomized, double‐blind, placebo‐controlled, dose‐response clinical trial examining safety and efficacy in patients with gout
Authors: Becker Michael A. , Schumacher H. Ralph , Wortmann Robert L. , MacDonald Patricia A. , Palo William A. , Eustace Denise , Vernillet Laurent , Joseph‐Ridge Nancy
Published: March 2005

Objective

Gout affects ∼1–2% of the American population. Current options for treating hyperuricemia in chronic gout are limited. The purpose of this study was to assess the safety and efficacy of febuxostat, a nonpurine selective inhibitor of xanthine oxidase, in establishing normal serum urate (sUA) concentrations in gout patients with hyperuricemia (≥8.0 mg/dl).

Methods

We conducted a phase II, randomized, double‐blind, placebo‐controlled trial in 153 patients (ages 23–80 years). Subjects received febuxostat (40 mg, 80 mg, 120 mg) or placebo once daily for 28 days and colchicine prophylaxis for 14 days prior to and 14 days after randomization. The primary end point was the proportion of subjects with sUA levels <6.0 mg/dl on day 28.

Results

Greater proportions of febuxostat‐treated patients than placebo‐treated patients achieved an sUA level <6.0 mg/dl at each visit (P < 0.001 for each comparison). The targeted sUA level was attained on day 28 in 0% of those taking placebo and in 56% of those taking 40 mg, 76% taking 80 mg, and 94% taking 120 mg of febuxostat. The mean sUA reduction from baseline to day 28 was 2% in the placebo group and 37% in the 40‐mg, 44% in the 80‐mg, and 59% in the 120‐mg febuxostat groups. Gout flares occurred with similar frequency in the placebo (37%) and 40‐mg febuxostat (35%) groups and with increased frequency in the higher dosage febuxostat groups (43% taking 80 mg; 55% taking 120 mg). During colchicine prophylaxis, gout flares occurred less frequently (8–13%). Incidences of treatment‐related adverse events were similar in the febuxostat and placebo groups.

Conclusion

Treatment with febuxostat resulted in a significant reduction of sUA levels at all dosages. Febuxostat therapy was safe and well tolerated.
A novel ultrasonographic synovitis scoring system suitable for analyzing finger joint inflammation in rheumatoid arthritis
Authors: Scheel Alexander K. , Hermann Kay‐Geert A. , Kahler Elke , Pasewaldt Daniel , Fritz Jacqueline , Hamm Bernd , Brunner Edgar , Müller Gerhard A. , Burmester Gerd R. , Backhaus Marina
Published: March 2005

Objective

To develop an ultrasonographic (US) synovitis scoring system suitable for evaluation of finger joint inflammation in patients with active rheumatoid arthritis (RA) and to compare semiquantitative US scoring with quantitative US measurements.

Methods

US was performed at the palmar and dorsal sides of the second through fifth metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints in 10 healthy subjects and in the clinically more affected hand in 46 RA patients. Ten patients additionally underwent magnetic resonance imaging (MRI). Synovitis was measured, standardized, and scored according to a semiquantitative method. The 2 methods (semiquantitative US scoring, quantitative US) were compared and statistical cutoffs were identified using receiver operating characteristic (ROC) curve analysis. MRI results were compared with semiquantitative US scoring and quantitative US results. The optimal US scoring method from 6 joint combinations was identified (ROC curve analysis).

Results

Synovitis was most frequently detected in the palmar proximal area (86% of affected joints). We found no significant differences between individual PIP joints or between individual MCP joints, indicating that all fingers within each of these joint groups should be treated equally for statistical calculations, although each joint group as a whole should be treated separately. The optimal cutoff point to distinguish between “health” and “pathology” was 0.6 mm both for MCP joints (sensitivity 94%, specificity 89%) and for PIP joints (sensitivity 90%, specificity 88%). There was no significant difference between semiquantitative US scores and quantitative US measurements. The best results for joint combinations were achieved using the “sum of 4 fingers” (second through fifth MCP and PIP joints) and “sum of 3 fingers” (second through fourth MCP and PIP joints) methods. Comparison of MRI results with semiquantitative US scores revealed high concordance.

Conclusion

US evaluation of finger joint synovitis can be considerably simplified by focusing on the palmar side and by applying semiquantitative grading instead of quantitative measurements. For evaluation of treatment efficacy based on synovitis in RA patients, we recommend using the “sum of 3 fingers” method in longitudinal trials.