bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of roughness as determined by atomic force microscopy on the wetting properties of PTFE thin films
Authors: Miller J. D. , Veeramasuneni S. , Drelich J. , Yalamanchili M. R. , Yamauchi G.
Published: April 2004

The influence of film roughness on the wetting properties of vacuum‐deposited polytetrafluorethylene (PTFE) thin films has been investigated using atomic force microscopy (AFM) and contact angle goniometry. Surface roughness has been characterized by atomic force microscopy in terms of RMS roughness (Rq) and fractal dimensions. A contact angle correlation with surface roughness, as determined by AFM, is evident from these results, which are discussed on the basis of wetting theory. The results also confirm that the high water contact angles (as high as 150°) recently observed at the surface of a new water repulsive coating material (mixture of PTFE and binder) are because of surface roughness. Such measurements clarify the effect of nanometer‐size surface asperities on the wetting properties of hydrophobic coating.
A constitutive model for nonlinear viscoelastic behavior of polymers
Authors: Drozdov A. D. , Kalamkarov A. L.
Published: April 2004

A new constitutive model for the nonlinear behavior of noncrosslinked polymers with infinitesimal strains is derived. It generalizes a model of adaptive links for the viscoelastic behavior of crosslinked polymers. According to the model, a viscoelastic medium is treated as a set of elastic springs that replace each other. The springs model chemical links between polymer molecules, which arise and collapse because of the micro‐Brownian motion, a law for replacing the springs determines the stress relaxation in a viscoelastic medium. Unlike crosslinked polymers, noncrosslinked polymers demonstrate steady‐state creep flow after some transition period. To describe both the transition process and the steady creep, the model distinguishes two different types of adaptive links. Links of the first type are ruptured under loading, whereas links of the second type replace one another. Both these processes (destruction and replacement) are treated as kinetic, and equations of chemical kinetics are introduced for their description. The nonlinearity of the model arises because of a dependence of rates of kinetic processes on the stress intensity. The constitutive equations derived are testified by comparing theoretical results with data for polypropylene fibers. For the verification we use data presented by three independent sources. The results demonstrate good agreement between experimental observations and their theoretical predictions. Finally, the effect of molecular weight of polymers on parameters of the model is studied.
Prediction of cellular structure in free expansion polymer foam processing
Authors: Shafi Muhammad A. , Lee James G. , Flumerfelt Raymond W.
Published: April 2004

A model is presented for free expansion polymer foam processing that includes simultaneous nucleation and bubble growth. The nucleation model includes dissolved gas, small critical cluster size, elastic, and non‐ideal solution effects. An influence volume approach, which couples nucleation and bubble growth, is used to account for the limited supply of dissolved gas. The resulting set of equations are solved using a combination of numerical techniques. A parametric study is conducted to examine the effects of key process variables on bubble growth, nucleation, and final bubble size distribution.
The effect of the packing parameters, gate geometry, and mold elasticity on the final dimensions of a molded part
Authors: Leo V. , Cuvelliez Ch.
Published: April 2004

Despite a significant number of publications and the increasing use of numerical simulation, there is still a debate about the optimum gate design and packing conditions in the molding industry. Shrinkage uniformity for unfilled polymers is dominated by the time dependent pressure distribution in the cavity and the resulting volumetric shrinkage; gate freeze‐off is obviously important and difficult to predict; and pressure gradients during the packing phase, depend on process and design parameters and are also affected by the mold elasticity. Molding trials have been conducted on an instrumented mold (fan gated rectangular slab, 2 mm thick) under a variety of processing conditions and with different gate thicknesses using HDPE (Solvay Eltex A1050). Pressure decay during the molding cycle at different locations along the flow path have been correlated with sample thickness distribution. Overpacking at moderate packing pressure is shown to be a direct consequence of mold elasticity and to be related to both filling flow rate and gate thickness. The decay to a finite residual pressure can be computed by coupling the mold elasticity with the PVT behavior of the polymer. The results highlight the importance of gate design and processing parameters on the dimensional accuracy of the part and low internal stress level. When dealing with thick gates, packing pressure profiling appears to be the best way to avoid gate area overpacking. Mold elastic deformation can play a significant role in the cavity pressure‐time history, even for a seemingly stiff mold construction.
Estimates for process conditions during the vibration welding of thermoplastics
Authors: Nonhof C. J. , Riepen M. , Melchers A. W.
Published: April 2004

The aim of this work is to interpret experimental findings of Stokes and Schlarb on the basis of analytical formulas and finite element calculations. In the analytical approach, some simplifications that had to be made proved to be inappropriate. Only computer calculations may reveal the details of the processes involved in vibration welding. Comparison of the computer calculations with the experiments reveals that even transient effects in viscosity have to be considered. Viscosity is dependent not only on temperature and shear rate, but also on the frequency or amplitude of vibration. After correction for these effects, the correlation between theory and experiments proved to be excellent. Based on the calculations, some recommendations are presented to improve weld quality, as ascertained by the type of fracture in a tensile test, by changing the welding parameters.
A micromechanical model for the elastic properties of semicrystalline thermoplastic polymers
Authors: Guan X. , Pitchumani R.
Published: April 2004

This paper presents a micromechanical analysis of the elastic properties of semicrystalline thermoplastic materials. A lamellar stack aggregate model reported in the literature is used to derive tighter bounds and a self‐consistent scheme for the elastic modulus, and it is shown that the existing geometric models of the microstructures are not effective in predicting experimentally measured modulus of semicrystalline materials. Toward addressing this limitation, a model based on Mori‐Tanaka's mean field theory is developed by treating the semicrystalline materials as short‐fiber reinforced composites, in which the lamella crystalline phase is modeled as randomly embedded anisotropic ellipsoidal inclusions, and the amorphous phase as an isotropic matrix. The lamellae are characterized by two independent aspect ratios from three distinct geometric axes in general. Existing morphological studies on polyethylene (PE) and a syndiotactic polystyrene (sPS) are used to deduce the corresponding lamella aspect ratios, based on which the theoretical model is applied to predict the elastic modulus of the two material systems. The model predictions are shown to compare well with the reported measurements on the elastic moduli of PE and sPS. Polym. Eng. Sci. 44:433–451, 2004. © 2004 Society of Plastics Engineers.
Curing kinetics and chemorheological analysis of polyurethane formation
Authors: Dimier F. , Sbirrazzuoli N. , Vergnes B. , Vincent M.
Published: April 2004

The cross‐linking kinetics and the rheological behavior of a polyurethane system during curing are investigated by DSC and small amplitude oscillatory shear rheometry. In this study, isoconversional methods are applied to understand the reaction complexity. The activation energy depends on the extent of conversion. It can be shown that three parallel reactions occur during the evolution of the global reaction in non‐isothermal conditions. An original multi‐step model can involve these three parallel independent reactions. Dynamic viscosity is measured as a function of time and is found independent of shear rate. Isothermal viscosity rise is related to reaction extent by a phenomenological model. The gelation time is determined by the tanδ crossover at different frequencies. Polym. Eng. Sci. 44:518–527, 2004. © 2004 Society of Plastics Engineers.
Essential work of fracture (EWF) analysis for compression molded alternating poly(propylene carbonate)
Authors: Fung K. L. , Zhao H. X. , Wang J. T. , Meng Y. Z. , Tjong S. C. , Li R. K. Y.
Published: April 2004

In this investigation, the main objective was to study the mechanical properties of alternating poly(propylene carbonate) copolymer (PPC). The PPC used in this study was derived from propylene oxide and carbon dioxide using zinc glutarate as catalyst. The molecular weight of the PPC copolymer used in this study has M̄n∼33,000. The synthesized PPC was compression molded into sheets of thickness ∼1mm. The fracture toughness of the PPC films was determined using the essential work of fracture (EWF) technique, at a laboratory temperature of 20°C, and a loading rate of 1 mm/min. During the EWF measurement, a significant amount of plastic deformation has taken place around the initial ligament region. The measured specific total fracture work (wf) was observed to vary in a linear fashion with the specimen ligament (l), and hence satisfied the basic requirement for EWF analysis. The specific essential fracture work (we) for the PPC film was measured to be 11.0 kJ/m2. The PPC showed a prominent recovery behavior. The severely deformed region surrounding the fracture ligament was observed to recover completely 8 days after fracture testing. Polym. Eng. Sci. 44:580–587, 2004. © 2004 Society of Plastics Engineers.
Mechanical properties and crystallization behavior of poly(lactic acid) blended with dendritic hyperbranched polymer
Authors: Zhang Jian‐Feng , Sun Xiuzhi
Published: April 2004

Mechanical properties of poly(lactic acid) (PLA) blended with a small amount of dendritic hyperbranched polymer (DHP) were investigated. Effects of DHP and starch on mechanical properties of PLA were compared. DHP significantly improved tensile strength and elongation at break of PLA. A small amount of starch in PLA slightly improved PLA's elongation, but had no effect on tensile strength. Isothermal crystallization kinetics of PLA blended with DHP and starch were also studied. Both DHP and starch acted as nucleation agents and significantly increased crystallization rate and crystallinity of PLA. Copyright © 2004 Society of Chemical Industry
Using the common sense model to understand perceived cancer risk in individuals testing for BRCA1/2 mutations
Authors: Kelly Kimberly , Leventhal Howard , Andrykowski Michael , Toppmeyer Deborah , Much Judy , Dermody James , Marvin Monica , Baran Jill , Schwalb Marvin
Published: April 2004

The common sense model posits that individuals' understanding of illness is based upon somatic symptoms and life experiences and thus may differ significantly from the biomedical view of illness. The current study used the common sense model to understand cancer risk perceptions in 99 individuals testing for BRCA1/2 mutations. Specifically, we examined change from post‐counseling to post‐result in (1) absolute risk (risk of developing cancer in one's lifetime) and (2) comparative risk (risk relative to the general population). Results indicated that absolute risk showed a trend such that those with a personal history of cancer receiving uninformative negative results reported decreased absolute risk. Further, individuals receiving uninformative negative results reported decreased comparative risk. Those with no personal cancer history receiving informative negative results did not decrease in risk over time nor did their risk differ from those with a personal cancer history, evidencing unrealistic pessimism regarding their risk of cancer. The reasons provided for individuals' risk perceptions could be classified in terms of attributes of the common sense model and included the: (1) causes of cancer (e.g. family history, mutation status); (2) control or cure of cancer through health behaviors and/or surgery; and (3) perceived timeline for developing cancer (e.g. time left in life to develop cancer). We conclude that key to developing interventions to improve understanding of cancer risk and promoting effective cancer control mechanisms is an understanding of the specific reasons underlying individuals' perceptions of cancer risk. Copyright © 2004 John Wiley & Sons, Ltd.
Generation of cytotoxic T lymphocytes specific for the prostate and breast tissue antigen TARP
Authors: Carlsson Björn , Tötterman Thomas H. , Essand Magnus
Published: April 2004

BACKGROUND

Expansion of cytotoxic T lymphocytes (CTL) directed against peptide epitopes from antigens that are specifically expressed by normal and neoplastic prostate epithelial cells has during the last years emerged as an interesting therapeutic approach to treat advanced prostate cancer. TCRγ alternate reading frame protein (TARP) is a protein that in males is specifically expressed by normal prostate epithelial cells and prostate cancer cells. We have evaluated TARP for human leukocyte antigen (HLA)‐A*0201‐restricted peptides capable of triggering TARP‐specific CTL.

METHODS

Dendritic cells (DC) were pulsed either with synthetic peptides derived from the natural amino acid sequence of TARP or with cognate peptides having enhanced affinity for HLA‐A*0201 due to an N‐terminal anchor residue substitution. The peptide‐pulsed DC were used to stimulate autologous T cells ex vivo.

RESULTS

We were able to generate T cells against TARP27–35 and TARP4–13 and their mutated counterparts TARP(V28L)27–35 and TARP(P5L)4–13. The use of affinity‐enhanced peptides resulted in the generation of T cells recognizing target cells displaying either wild‐type or mutated peptide. We further show that TARP‐specific T cells can be tetramer‐sorted and subsequently expanded to large numbers by general T cell stimulation, with retained specificity and activity. Sorted and expanded T cells, obtained by stimulation with TARP(P5L)4–13, exert moderate lysis of the TARP‐expressing prostate cancer cell line, LNCaP, and breast cancer cell line, MCF‐7, indicating that the TARP4–13 epitope may be endogenously processed and presented by TARP‐positive, HLA‐A*0201‐positive cells.

CONCLUSIONS

Our findings suggest that synthetic TARP peptides, such as TARP(P5L)4–13, may play a role in prostate and breast cancer immunotherapy. © 2004 Wiley‐Liss, Inc.
Therapeutic activity of 3,3′‐diindolylmethane on prostate cancer in an in vivo model
Authors: Nachshon‐Kedmi Maya , Fares Fuad A. , Yannai Shmuel
Published: April 2004

BACKGROUND

Prostate cancer (PC) is the second leading cancer‐related death in men in Western countries. Hence, efficient anti‐carcinogenic and therapeutic compounds against PC are badly needed. We have previously shown that 3,3′‐diindolylmethane (DIM) has a suppressive effect on the growth of human breast and PC cell lines. The objective of this study was examination of the potential therapeutic effects of DIM in an in vivo model.

METHODS

TRAMP‐C2, a mouse PC cell line, was injected into the flank of male C57BL/6 mice. When tumors appeared, mice were injected intraperitoneally with either corn oil (vehicle) or DIM (2.5, 5, or 10 mg per kg body weight) 3‐times a week, for 3 weeks, and tumor volumes were measured bi‐weekly with calibermeters. Later, the tumors were removed, their final weights and volumes were measured, and tumor sections were tested for histological studies.

RESULTS

DIM had a significant inhibitory effect, caused by diminished tumor growth. Histological examination of tumors from treated groups revealed apoptosis and decreased cell proliferation, compared with the controls. DIM didn't affect body weights or kidney and liver functioning.

CONCLUSIONS

The inhibitory action of DIM on tumor growth was demonstrated in vivo. Hence, this compound at the concentrations tested may offer an effective and non toxic therapeutic means against tumor growth in rodents, and may serve as a potential natural anti‐carconigenic compound in humans. © 2004 Wiley‐Liss, Inc.
Restoration of fibroblast growth factor receptor2 suppresses growth and tumorigenicity of malignant human prostate carcinoma PC‐3 cells
Authors: Yasumoto Hiroaki , Matsubara Akio , Mutaguchi Kazuaki , Usui Tsuguru , McKeehan Wallace L.
Published: April 2004

BACKGROUND

Fibroblast growth factors (FGFs) and their receptors (FGFRs) expedite stromal–epithelial communication in development and homeostasis of the human prostate. Loss of resident epithelial cell FGFR2IIIb that responds to stromal FGF7 and FGF10 accompanies malignant progression of both model animal and human prostate tumors.

METHODS

We examined whether restoration of FGFR2IIIb by transfection in the malignant human prostate tumor PC‐3 cell line restored cellular properties associated with less malignant tumors. Cell proliferation, apoptosis, and tumor cell implants were used to monitor malignant properties. Activity of FGFR2IIIb was assessed by immunoblot of FRS2 and p44/42 MAP kinase. Immunochemical analysis of pancytokeratin and lactoferrin expression was utilized to assess changes in cellular differentiation.

RESULTS

Expression of FGFR2IIIb in PC‐3 cells by transfection resulted in growth suppression in vitro and reduced tumor formation in vivo concurrent with increased cellular differentiation and apoptosis.

CONCLUSIONS

The results indicate that restoration of FGFR2IIIb to the malignant human prostate epithelial cell prototype PC‐3 restores properties associated with nonmalignant tumors and normal cells. This further suggests that epithelial cell resident, homeostasis‐promoting FGFR2 may be involved in suppression of malignancy and that restoration may be a candidate for gene therapy of hormone‐refractory prostate cancer. © 2004 Wiley‐Liss, Inc.
Trefoil factor 3 overexpression in prostatic carcinoma: Prognostic importance using tissue microarrays
Authors: Faith Dennis A. , Isaacs William B. , Morgan James D. , Fedor Helen L. , Hicks Jessica L. , Mangold Leslie A. , Walsh Patrick C. , Partin Alan W. , Platz Elizabeth A. , Luo Jun , De Marzo Angelo M.
Published: April 2004

BACKGROUND

Human intestinal trefoil factor 3 (TFF3) is a member of a family of polypeptides encoded by a cluster of genes on chromosome 21. Through gene expression profiling studies TFF3 mRNA has been found to be overexpressed in prostate cancer.

METHODS

We used immunochemistry on tissue microarrays and software tools, collectively referred to as TMAJ, for online assessment of staining to analyze samples from 294 primary tumors and 61 metastatic lesions.

RESULTS

Applying a cutoff of 20% of cells staining as positive, the frequency of staining was 18.8% in normal (51 of 272) and 47.0% in primary tumors (126 of 268), P < 0.0001, Wilcoxon rank sum). Expression of TFF3 in metastatic prostate cancer was similar to that in primary tumors. TFF3 expression was not associated with time to biochemical recurrence, development of distant metastasis, or death due to prostate cancer. Scoring data derived from visual estimation of expression correlated highly with semi‐automated image analysis using the Automated Cellular Imaging System (ACIS™) from Chromavision, Inc.

CONCLUSIONS

These studies validate that TFF3 is overexpressed at the protein level in a subset of primary and metastatic prostate cancers, show the first use of the TMAJ database, and demonstrate the ability to semi‐automatically scan and score immunohistochemically stained tissue microarray slides. © 2004 Wiley‐Liss, Inc.
Trefoil factor 3 is overexpressed in human prostate cancer
Authors: Garraway Isla P. , Seligson David , Said Jonathan , Horvath Steve , Reiter Robert E.
Published: April 2004

The trefoil factors are secreted peptides produced by normal intestinal mucosa. Members of the trefoil family are overexpressed in a variety of cancers and are associated with tumor invasion, resistance to apoptosis, and metastasis. Recent cDNA array analyses suggest that human intestinal trefoil factor 3 (TFF3) may be overexpressed in human prostate cancer. Immunohistochemistry was performed on a prostate cancer tissue microarray containing tumor tissue samples from 246 primary radical retropubic prostatectomy cases with antibodies specific for TFF3. Prostatic intraepithelial neoplasia (PIN), benign prostatic hyperplasia (BPH), and morphologically normal prostatic epithelium were represented on this array. Additionally, 18 metastatic lesions were also stained. Two independent pathologists scored the tissue arrays, with positive cases defined as those containing TFF3 staining in a majority of target cells within any spots representing the appropriate designated histology. Forty‐two percent of 236 cases containing prostate cancer stained positive for TFF3, while only 10% of 145 cases containing normal tissue and 18% of 91 cases containing BPH, stained positive. Seven of 18 (39%) metastatic lesions analyzed stained positive. Although TFF3 expression correlates significantly with prostate cancer, TFF3 expression did not correlate with Gleason grade, tumor stage, or rate of recurrence. These studies validate that TFF3 is overexpressed in a subset of primary and metastic prostate cancers. © 2004 Wiley‐Liss, Inc.
Correlation corrected band structures of homopolypeptides v. B3LYP band structures of 19 homopolypeptides
Authors: Bogar F. , Ladik J.
Published: April 2004

Ab initio B3LYP crystal orbital (CO) calculations have been performed on the 19 homopolypeptides (PolyGly, PolyAla, PolySer, PolyThre, PolyLeu, PolyiLeu, PolyVal, PolyAspAc, PolyAsp, PolyGlutAc, PolyGlut, PolyHist, PolyProl, PolyCyst, PolyMeth, PolyTyr, PolyPhenAla, PolyArg, and PolyLys) in their β pleated sheet conformation. Keeping the main chain conformation fixed as in PolyGly, the side chain geometries were optimized. For the calculation 2n+1 different k points were used with n = 8 for the case of simpler and n = 10 for more complicated side chains. The basis set applied was the double ζ one of Clementi. According to the results obtained, the conduction bands are shifted upward and the valance band downward, compared with the results of previous BLYP 1 and LDA 7 CO calculations. The bandwidths are similar to the previous cases. The band edges are in many cases not at the endpoints of the first Brillouin zones, causing nonmonotonous dispersion of both the conduction bands (CB) and the valance bands (VB), respectively. The fundamental gap values due to the upward shifts of the CB and downward shifts of the VB are substantially larger than in the case of our previous DFT CO calculations (values 6.0–7.0 eV). They are very close to the gap values, which can be estimated on the basis of experimental ultraviolet (UV) spectra of some homopolypeptides and on the basis of intermediate exciton theoretical calculations (6.5–7.5 eV). These surprisingly good results for the gaps are due to the compensation of errors (LDA or BLYP gives too small and simple HF provides too large gap values) in the B3LYP method. The admixture of the exact HF exchange with a weight of 0.19 obviously compensates the self interaction error occurring in the LDA or BLYP methods. This article discusses whether/how this result could be established by other B3LYP CO calculations on simple polymer chains and on stacked systems (e.g., nucleotide base stacks). Furthermore, a comparative analysis of the ground state DFT methods, the HF method and of the optimized effective potential method could throw more light on our successful theoretical results for the gaps of the homopolypeptides. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Mass spectra of nitro‐β,β‐dihalostyrenes
Authors: Lin Shaw‐Tao , Lee Chun‐Jen , Chen Li‐Chwen , Huang Keh‐Feng
Published: April 2004

The electron ionization (EI) fragmentation of nitro‐β,β‐dihalostyrenes depends strongly on the specific halogens present as well as on the position of the nitro group. β,β‐Difluorostyrenes yielded mainly fluoroacetylene ions as the base peaks and o‐nitro‐β,β‐dihalostyrene possibly furnished the ion with a structure similar to that of benzo[a]isoxazole (11). The structural identity of the ion was verified by comparing the collision‐induced dissociation (CID) spectra of m/z 119 ions from p‐ and o‐nitro‐β,β‐difluorostyrene, o‐nitro‐β,β‐dibromostyrene and compound 11. Copyright © 2004 John Wiley & Sons, Ltd.
The development and use of farm‐level indicators in England
Authors: Tzilivakis John , Lewis Kathy A.
Published: April 2004

In recent years the concept of ‘sustainability indicators’ has become important within agricultural policy development. However, as policy tools, many indicators are highly technical in nature and often appear relevant only at national level. Consequently, the key messages underpinning the indicators can easily become lost at farm level.

In order to drive progress towards sustainability it is important to define indicators at a level that is meaningful to the target audience and that encapsulates the spatial and temporal diversity of the farm environment.

In support of policy objectives the pilot national set of indicators of agricultural sustainability has been re‐cast into indicators that can be collected, interpreted and compared at a farm level. A software package that prioritizes the indicators according to farm type and that links trends with farm management decisions and practices, identifying steps for improvements, is used as the main means of knowledge transfer. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Synaptic arrangements between inner hair cells and tunnel fibers in the mouse cochlea
Authors: Sobkowicz Hanna M. , August Benjamin K. , Slapnick Susan M.
Published: April 2004

Hair cells, the sensory cells of the organ of Corti, receive afferent innervation from the spiral ganglion neurons and efferent innervation from the superior olivary complex. The inner and outer hair cells are innervated by distinctive fiber systems. Our electron microscopical studies demonstrate, however, that inner hair cells, in addition to their own innervation, are also synaptically engaged with the fibers destined specifically to innervate outer hair cells, within both the afferent and efferent innervation. Serial sections of the afferent tunnel fibers (destined to innervate outer hair cells) in the apical turn demonstrate that, while crossing toward the tunnel of Corti, they receive en passant synapses from inner hair cells. Each inner hair cell (in a series of five in the apical turn) was innervated by two tunnel fibers, one on each side. We show here for the first time that, in the adult, the afferent tunnel fibers receive a ribbon synapse from inner hair cells and form reciprocal contacts on their spines. Vesiculated efferent fibers from the inner pillar bundle (which carries the innervation to outer hair cells) form triadic synapses with inner hair cells and their synaptic afferent dendrites; the vesiculated terminals of the lateral olivocochlear fibers from the inner spiral bundle synapse extensively on the afferent tunnel fibers, forming triadic synapses with both afferent tunnel fibers and their synaptic inner hair cells. This intense synaptic activity involving inner hair cells and both afferent and efferent tunnel fibers, at their crossroad, implies functional connections between both inner and outer hair cells in the process of hearing. Synapse 52:299–315, 2004. © 2004 Wiley‐Liss, Inc.
Diet and chronic haloperidol effects on rat midbrain dopamine neurons
Authors: Hamilton Margaret E. , Freeman Arthur S.
Published: April 2004

The effects of dietary glucose (chow containing 0%, 10%, 20%, or 40% glucose, w/w) on chronic haloperidol‐induced changes in dopamine (DA) neuronal activity were tested. Rats were treated daily by oral gavage for 21 days with either water or 0.5 mg/kg haloperidol, then anesthetized for in vivo electrophysiological recording. The numbers of spontaneously active DA neurons in the substantia nigra (A9) and ventral tegmental area (A10) regions of the midbrain were estimated with the cells‐per‐track sampling method. In rats fed standard chow, haloperidol significantly reduced the number of active neurons in both regions compared to water controls. In water controls there were no differences in DA cells per track between rats fed standard chow or chow containing 10% or 20% glucose, whereas these glucose diets significantly attenuated the effects of chronic haloperidol on DA cells per track. The 40% glucose diet itself nonsignificantly reduced cells per track and, in turn, nonsignificantly attenuated the effects of haloperidol. The results demonstrate that dietary glucose content can alter haloperidol‐induced changes in the activity of midbrain DA neurons. Synapse 53:1–5, 2004. © 2004 Wiley‐Liss, Inc.
Chemical speciation and toxicity of metals assessed by three bioluminescence‐based assays using marine organisms
Authors: Deheyn Dimitri D. , Bencheikh‐Latmani Rizlan , Latz Michael I.
Published: April 2004

Metal toxicity is a function of the biology of the target organism and the chemical speciation of the metal. The toxicity of 11 metals was assessed with three cell‐based bioassays based on marine organisms: the bacterium Photobacterium phosphoreum of the Microtox® bioassay, an environmental strain of P. phosphoreum, and photocytes isolated from the brittlestar Ophiopsila californica. Metal speciation was calculated for three commonly used media: NaCl‐based Microtox® bioassay medium, artificial seawater glycerol, and artificial seawater. Decreased bioluminescence was considered a proxy for cell toxicity. In all three assays the elements Cd and Hg exhibited similar speciation as well as similar toxicity profiles. The element Cu was toxic in all three assays despite different metal speciation for the P. phosphoreum bioassay. The element Ag was toxic to both bacterial strains but not to photocytes despite a similar chemical speciation for all three assays. In general, the Microtox® bioassay was sensitive to all metals (except Pb), whereas the photocytes were the least sensitive to the metals. The heightened response of the Microtox® bioassay probably resulted from a combination of the limited complexing power of the medium and the greater sensitivity of the bacterial strain. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 161–178, 2004.
Anatoxin‐a toxin in the cyanobacterium Planktothrix rubescens from a fishing pond in northern Italy
Authors: Viaggiu Emanuela , Melchiorre Serena , Volpi Fabrizio , Di Corcia Antonio , Mancini Roberta , Garibaldi Letizia , Crichigno Giuseppe , Bruno Milena
Published: April 2004

A heavy algal bloom occurring in a fishing pond in northern Italy full of Salmo trutta was examined for algae taxonomy and toxic production. The dominant algal species (98%) was identified as the cyanobacterium Planktothrix rubescens (D.C. ex GOMONT) Komarek Anagnostidis, based on morphological examination, and it was revealed to be toxic in mouse and Vibrio fischeri bioassays. The toxin was identified as anatoxin‐a using high‐performance liquid chromatography and confirmed using liquid chromatography–mass spectrometry (LC‐MS). The mouse bioassay gave signs of poisoning, as previously reported for anatoxin‐a. The LC‐MS confirmed the presence of an anatoxin‐a peak at m/z 166 (M+H+). The content of toxin in the field population was estimated at 12.13 μg/g of fresh cells. The bloom was sustained by the very high N/P ratio in the water. This is the first report in Italy of an anatoxin‐a‐producing Planktothrix rubescens population. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 191–197, 2004.
Differential Diagnosis of Stenosing Lesions at the Hepatic Hilus
Authors: Koea Jonathan , Holden Andrew , Chau Kai , McCall John
Published: April 2004

A significant number of stenosing lesions at the hepatic hilus represent benign disease rather than hilar cholangiocarcinoma. It is unclear, however, which perioperative investigations are useful for defining benign lesions in this location. A series of 49 consecutive patients who presented with obstructive jaundice due to a stenosing lesion at the hepatic hilus were investigated by documenting elevated plasma bilirubin levels, the presence of weight loss, and elevated carcinoembryonic antigen (CEA) and Ca 19‐9 concentrations. Radiologic investigations included direct cholangiography, transabdominal ultrasonography, computed tomographic (CT) scans and magnetic resonance imaging (MRI). A tissue diagnosis was obtained in all patients, and the preoperative investigations were reviewed to assess their accuracy for predicting malignancy. The final tissue diagnosis was a benign lesion in 12 patients (benign idiopathic strictures 10, choledocholithiasis 2). Among the 37 patients who presented with a malignant lesion, 2 had metastatic colorectal cancer, 7 had gallbladder cancer, and 28 had hilar cholangiocarcinoma. Of the 12 patients with benign lesions, 4 (33%) had elevated tumor markers (CEA and CA 19‐9), 12 (100%) had cholangiograms suspicious for malignancy, and 9 (75%) had CT and MRI features consistent with a malignant diagnosis. Thus among patients presenting with hilar strictures approximately one‐fifth are due to nonmalignant causes, but the preoperative diagnosis is difficult and resection remains the most reliable way to rule out malignancy in this site.
Preoperative Ultrasonographic Examination for Lymph Node Metastasis: Usefulness when Designing Lymph Node Dissection for Papillary Microcarcinoma of the Thyroid
Authors: Ito Yasuhiro , Tomoda Chisato , Uruno Takashi , Takamura Yuuki , Miya Akihiro , Kobayashi Kaoru , Matsuzuka Fumio , Kuma Kanji , Miyauchi Akira
Published: April 2004

Papillary microcarcinoma has an excellent prognosis after surgical treatment, but how to dissect the lymph nodes remains an open question. In this study, we investigated whether modified radical neck dissection (MND) affected the lymph node recurrence‐free survival (LN‐RFS) rate for 590 patients with papillary microcarcinoma and recurrence in the lateral compartment who underwent surgery in our hospital between 1993 and 2001. MND was performed in 316 patients, and metastasis in lateral compartment was preoperatively detected on ultrasonography in 67. These 67 patients showed significantly worse LN‐RFS (p = 0.0038) than the remaining 249 patients without preoperatively detectable lateral node metastasis. Of the 523 patients (590 minus the 67 patients) whose lateral node metastasis was not detected preoperatively, 249 underwent MND; the remaining 274 patients did not. There was no significant difference in LN‐RFS between these two groups. Our preliminary data suggest that with papillary microcarcinoma: (1) MND is not necessary in patients without lateral node metastasis detected on ultrasonography preoperatively, and (2) patients with preoperatively detected lateral node metastasis are more likely to develop recurrence in the lymph nodes so careful MND should be performed.
Methods Used by the Hippocratic Physicians for Weight Reduction
Authors: Christopoulou‐Aletra Helen , Papavramidou Niki
Published: April 2004

In classical antiquity, particularly in the Hippocratic Corpus, obesity was considered the cause of disease and, in the extreme, death. This attitude mirrors the general ideology of the times where any deviation from the norm and from logic was unacceptable. The image of balance and of the ideal body weight was clearly depicted in ancient Greek art. The same attitude is reflected in the Hippocratic texts where obesity is again condemned as a deviation from the norm. The cause of obesity refers to the surplus of one of the liquids circulating in the body. Thus treatment points mainly to restoring the balance of liquids. This is accomplished by diet, drugs, and most importantly exercise. Walking, running, wrestling, and other practices are advised together with baths, massage, rest, and the “appropriate” life style.
Impaired postural control in patients affected by tension‐type headache
Authors: Giacomini P.G. , Alessandrini M. , Evangelista M. , Napolitano B. , Lanciani R. , Camaioni D.
Published: April 2004

Sixteen subjects, affected by chronic tension‐type headache (TTH) accordingly to the International Headache Society Classification (1988) criteria, in presence of tenderness in pericranial muscles, with a mean age of 37 ± 11.8 years, and ten healthy volunteer subjects, age and sex matched, were submitted to postural analysis by Static Posturography (S.Ve.P. Amplaid). Aim of the study was to evaluate whether patients with TTH have disturbed postural control, as compared to normal subjects. Postural analysis considered all posturographic variables but focused on spectral frequency analysis of body sway. In both open (OE) and closed eyes (CE) condition, spectral frequency analysis showed a significantly increased body sway at low (OE=p≤0.01; CE=p≤0.01) and middle (OE=p≤0.01; CE=p≤0.01) frequencies on the antero‐posterior (y) plane and at low frequencies (OE=p≤0.05; CE=p≤0.05) on the lateral (x) plane. Statistical analysis was performed using the Student's t test for unpaired data, p value ≤0.05 defined significant.

The proprioceptive input seems to be predominant at middle and high frequencies in maintaining posture, our results seem then to suggest a proprioceptive disturbance in TTH patients. The disturbance is likely related to chronic pericranial muscle contraction and tenderness. Posturography and spectral analysis may help not only in the diagnosis of a postural disturbance but even more in the follow‐up of TTH patients, during and after a medical and/or a rehabilitative treatment.
Stress relaxation of bone significantly affects the pull‐out behavior of pedicle screws
Authors: Inceoglu Serkan , McLain Robert F. , Cayli Suleyman , Kilincer Cumhur , Ferrara Lisa
Published: April 2004

The initial fixation strength of pedicle screws is commonly tested using a standard pull‐out test with load applied at a constant rate. This method overlooks the cyclic nature of in situ loading responsible for clinical failure. This study was undertaken to determine the effects of stress relaxation properties at the bone–screw interface on screw fixation strength. Pedicle screws were inserted into calf lumbar vertebrae using a paired testing array. After embedding and mounting in a custom fixture, axial pull‐out tests were performed at the rates of 1, 5, and 25 mm/min. For each vertebra, one screw was pulled at a continuous rate. The other screw was pulled at increments of 0.5 mm, at the same rate, with 1000 s pause between increments. Peak load, energy‐to‐failure, displacement‐to‐failure, and stiffness were calculated for each screw pull‐out test. Two‐way ANOVA showed that the standard pull‐out method yielded significantly higher peak loads (p < 0.05) at faster pull‐out rates and higher stiffnesses (p < 0.05) at all rates compared to the stress relaxation pull‐out protocol. These results suggest that the stress relaxation properties of bone significantly affect the pull‐out behavior of pedicle screws, reducing the peak load and stiffness values observed during testing. This mode of testing may provide a better biomechanical model of screw pull‐out failure and a more accurate estimate of initial fixation strength. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Prophylactic Effect of Pentoxifylline on Radiotherapy Complications: A Clinical Study
Authors: Aygenc Erdinc , Celikkanat Serdar , Kaymakci Mustafa , Aksaray Ferdi , Ozdem Cafer
Published: April 2004

OBJECTIVE

The purpose of this study was to assess the prophylactic effect of pentoxifylline (Ptx) on complications related to radiation.

STUDY DESIGN AND SETTING

Seventy‐eight patients who had postoperative radiotherapy for squamous cell carcinoma of the head and neck were enrolled into a prospective study. Patients were randomly assigned to the Ptx group (40 patients) and the control group (38 patients). Ptx was given to the patients at a dose of 400 mg 3 times a day orally to a total of 1200 mg. We noted radiotherapy complications in each group.

RESULTS

Four patients were not able to tolerate this drug due to the development of gastrointestinal symptoms and dizziness. Late skin changes, fibrosis, and soft tissue necrosis were more severely in the control group than in the Ptx group (P < 0.05). We could find no positive effects on acute skin reactions and pain (P > 0.05).

CONCLUSION

Our study suggests that Ptx has a prophylactic effect on the radiation complications. This can be explained by protective effect of Ptx against vascular pathology. (Otolaryngol Head Neck Surg 2004;130:351–6.)
Radiofrequency Ablation versus Electrocautery in Tonsillectomy
Authors: Hall Daniel J. , Littlefield Philip D. , Birkmire‐Peters Deborah P. , Holtel Capt Michael R.
Published: April 2004

OBJECTIVES

The objective of this study was to compare the safety, difficulty of removal, and postoperative pain profile of radiofrequency ablation versus standard electrocautery removal of tonsils.

STUDY DESIGN AND SETTING

A prospective, blinded study was designed to remove 1 tonsil with each of the 2 methods. Time of operation, estimated blood loss, difficulty of operation, postoperative pain, rate of postoperative hemorrhage, and the patient's preferred technique were evaluated.

RESULTS

The operating time was significantly longer (P < 0.007) and the patients reported significantly less pain (P < 0.001) with radiofrequency ablation. There were no differences in blood loss, difficulty of operation, or postoperative hemorrhage rates. The patients preferred the radiofrequency ablation technique (P < 0.001).

CONCLUSION

Radiofrequency ablation is a viable method to remove tonsillar tissue. Operating time for this procedure will likely decrease with experience. There was significantly less pain reported with radiofrequency ablation compared with standard electrocautery. (Otolaryngol Head Neck Surg 2004;130:300–5.)
Minimizing Complications in the Use of Titanium Condylar Head Reconstruction Prostheses
Authors: Daniel Elena , Browne J. Dale
Published: April 2004

OBJECTIVE

The study goals were to evaluate the use of titanium condylar prostheses in the setting of tumor resection and to discuss the techniques used to minimize complications.

STUDY DESIGN AND SETTING

We conducted a retrospective review of a case series in a tertiary care hospital. Six patients underwent mandibulectomy, including the condyle, with primary reconstruction using titanium condylar prostheses. Charts were reviewed for operative technique, pathology, and complications.

RESULTS

Pathology included squamous cell carcinoma, Ewing's sarcoma, embryonic rhabdomyo‐sarcoma, giant cell granuloma, and adenocarcinoma. Three patients are alive without disease. Follow‐up spanned 6.4 years with premorbid occlusion established in all cases, and there were no prosthesis extrusions or erosions. The condylar head was wrapped in preserved joint capsule or adjacent temporalis muscle/fascia and secured with permanent purse‐string sutures; careful duplication of the length, and angulation of the native mandible from the angle to the superior extent of the condylar head.

CONCLUSION

Titanium condylar prostheses are a viable choice in the setting of tumor resection and reconstruction, with appropriate technical precautions. (Otolaryngol Head Neck Surg 2004;130: 344–50.)
Outcomes after Nasal Septoplasty: Results from the Nasal Obstruction Septoplasty Effectiveness (NOSE) Study
Authors: Stewart Michael G. , Smith Timothy L. , Weaver Edward M. , Witsell David L. , Yueh Bevan , Hannley Maureen T. , Johnson Jonas T. ,   The Nose Study Investigators
Published: April 2004

OBJECTIVE

Our goal was to assess disease‐specific quality of life outcomes after nasal septoplasty in adults with nasal obstruction.

DESIGN, SETTINGS, AND PATIENTS

We conducted a prospective observational outcomes multicenter study with 14 sites and 16 investigators, including private practice and academic settings. Patients had had septal deviation and symptomatic nasal obstruction for at least 3 months, and medical management had failed.

METHODS

Patients with septal deviation completed a validated outcomes instrument (the Nasal Obstruction Septoplasty Effectiveness (NOSE) scale) before and 3 and 6 months after septoplasty, with or without partial turbinectomy.

RESULTS

Fifty‐nine patients underwent surgery; there was a significant improvement in mean NOSE score at 3 months after septoplasty (67.5 versus 23.1, P < 0.0001), and this improvement was unchanged at 6 months. Patient satisfaction was very high, and patients used significantly fewer nasal medications.

CONCLUSIONS

In patients with septal deformity, nasal septoplasty results in significant improvement in disease‐specific quality of life, high patient satisfaction, and decreased medication use. (Otolaryngol Head Neck Surg 2004;130:283–90.)
Venous Drainage of the Platysma Myocutaneous Flap
Authors: Agarwal Anurag , Schneck Carson D. , Kelley Daniel J.
Published: April 2004

OBJECTIVES

The platysma myocutaneous flap offers a regional reconstruction option for relatively small soft tissue defects in the head and neck area. However, epidermolysis of its skin paddle with resultant fibrosis and tongue tethering has been documented. This has been attributed to arterial and/or venous vascular compromise. We investigated the venous drainage patterns of this flap in a cadaveric study.

STUDY DESIGN AND SETTING

We made selective Microfil dye injections into the external and internal jugular veins of 5 cadavers. A wide cervical flap was then raised, and anatomic dissection of the superficial and deep venous systems was performed to identify the dominant draining veins of the platysma flap.

RESULTS

Universally, small communicating veins from the internal jugular venous system were noted to drain the platysma flap anteriorly. The external jugular vein was noted to drain the flap posteriorly.

CONCLUSIONS

Although it is difficult to preserve the anterior communicating veins with 180° flap rotation, the results of this study suggest a possible benefit of external jugular vein harvest in continuity with the platysma flap. Further clinical studies are needed to assess whether flap venous congestion, epidermolysis, and resultant fibrosis can be minimized with this technique. (Otolaryngol Head Neck Surg 2004;130:357–9.)