bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flexural Properties and Surface Finishing of Acetal Resin Denture Clasps
Authors: Turner Jonathan W. , Radford David R. , Sherriff Martyn 
Published: March 2005

PurposeThis study examined flexural properties of acetal resin to determine the appropriate design for an acetal resin removable partial denture clasp. The effectiveness of various acetal resin polishing procedures was also evaluated using scanning electron microscopy.Materials and MethodsLoads of up to 1,500 g were applied to cylindrical acetal resin specimen lengths of 5, 10, and 15 mm, and the degree of deflection of the specimen tip was measured. Specimens were 2 mm and 1.5 mm in diameter with a round cross‐section (R2 and R1.5, respectively), as well as 2 mm in diameter and half‐round in cross‐section. Half‐round specimens were loaded with their flat surface vertical and then horizontal (HRV and HRH, respectively). Contour plots showing load and deflection for varying lengths of resin were developed for each cross‐sectional type based on specimen length, and the stiffness was calculated. Additional acetal resin specimens underwent polishing techniques including tungsten carbide burs, aluminium oxide stones, abrasive impregnated rubber points, and “Polish‐D.” Polished specimens were examined with scanning electron microscopy to compare surface roughness.ResultsFor the 5‐mm‐length specimens, the median stiffness values decreased in the following order: R2 > HRV > HRH > R1.5. The median stiffness values for the 10‐mm and 15‐mm lengths followed a similar trend. At each length, the R2 specimen was generally at least twice as stiff as other designs. Regarding polishing, the smoothest surface was seen on the specimen that was polished with the rubber point followed by “Polish‐D.”ConclusionsTo have stiffness similar to a cast cobalt‐chromium clasp 15 mm long and 1 mm in diameter, a suitable acetal resin clasp must be shorter (approximately 5 mm) with greater cross‐sectional diameter (approximately 1.4 mm). To obtain a smooth surface, the acetal resin clasp should be polished with a rubber point followed by a material such as “Polish‐D.”
TRAINING EFFECTS ON PERFORMANCE OF DESCRIPTIVE PANELISTS
Authors: CHAMBERS DELORES H. , ALLISON ANN‐MARIE A. , CHAMBERS EDGAR 
Published: March 2005

ABSTRACT The amount of training necessary to adequately “train” a descriptive panel is a matter of contention. The objectives of this research were to compare the performance of descriptive panelists after short‐term (4 h), moderate (60 h) and extensive training (120 h). Seven screened panelists were chosen to evaluate three commercial tomato pasta sauces after each training period. Panelist performance improved with increased training. Sample differences were observed in all texture attributes and some flavor attributes, even after the shortest training time (4 h). However, more differences were found with at least 60 h of product training. After 120 h of training, product differences for all texture attributes and most of the flavor attributes studied could be ascertained by the trained panelists. These results suggested that only limited training may be necessary to find differences among products for many texture attributes and some flavor attributes. However, extensive training may be required to reduce variation among panelists and increase the discriminant abilities of panelists.
Intracellular Glycosylphosphatidylinositols Accumulate on Endosomes: Toxicity of Alpha-Toxin toLeishmania major
Authors: Zheng Zhifeng , Tweten Rodney K. , Mensa-Wilmot Kojo 
Published: March 2005

ABSTRACTGlycosylphosphatidylinositols (GPIs) are ubiquitous glycolipids in eukaryotes. In the protozoanLeishmania major, GPIs occur “free” or covalently linked to proteins (e.g., gp63) and polysaccharides. While some free GPIs are detected on the plasma membrane, specific sites where GPIs accumulate intracellularly are unknown in most cells, although the glycolipids are synthesized within the secretory system. Herein, we describe a protocol for identifying intracellular sites of GPI accumulation by using alpha-toxin (fromClostridium septicum). Alpha-toxin bound to gp63 and GPIs fromL. major. Intracellular binding sites for alpha-toxin were determined in immunofluorescence assays after removal of GPI-anchored macromolecules (e.g., gp63) from the plasma membrane of fixed cells by using detergent. Endosomes were a major site for GPI accretion inL. major. GPI-less gp63 was detected at the endoplasmic reticulum. In studies with live parasites, alpha-toxin killedL. majorwith a 50% lethal concentration of 0.77 nM.
Regulation of the Cdc42/Cdc24 GTPase Module during
Candida albicans
Hyphal Growth
Authors: Bassilana Martine , Hopkins Julie , Arkowitz Robert A. 
Published: March 2005

ABSTRACT

The Rho G protein Cdc42 and its exchange factor Cdc24 are required for hyphal growth of the human fungal pathogen
Candida albicans
. Previously, we reported that strains ectopically expressing Cdc24 or Cdc42 are unable to form hyphae in response to serum. Here we investigated the role of these two proteins in hyphal growth, using quantitative real-time PCR to measure induction of hypha-specific genes together with time lapse microscopy. Expression of the hypha-specific genes examined depends on the cyclic AMP-dependent protein kinase A pathway culminating in the Efg1 and Tec1 transcription factors. We show that strains with reduced levels of
CDC24
or
CDC42
transcripts induce hypha-specific genes yet cannot maintain their expression in response to serum. Furthermore, in serum these mutants form elongated buds compared to the wild type and mutant budding cells, as observed by time lapse microscopy. Using Cdc24 fused to green fluorescent protein, we also show that Cdc24 is recruited to and persists at the germ tube tip during hyphal growth. Altogether these data demonstrate that the Cdc24/Cdc42 GTPase module is required for maintenance of hyphal growth. In addition, overexpression studies indicate that specific levels of Cdc24 and Cdc42 are important for invasive hyphal growth. In response to serum,
CDC24
transcript levels increase transiently in a Tec1-dependent fashion, as do the G-protein
RHO3
and the Rho1 GTPase activating protein
BEM2
transcript levels. These results suggest that a positive feedback loop between Cdc24 and Tec1 contributes to an increase in active Cdc42 at the tip of the germ tube which is important for hypha formation.
The Acetate Switch
Authors: Wolfe Alan J. 
Published: March 2005

SUMMARYTo succeed, many cells must alternate between life-styles that permit rapid growth in the presence of abundant nutrients and ones that enhance survival in the absence of those nutrients. One such change in life-style, the “acetate switch,” occurs as cells deplete their environment of acetate-producing carbon sources and begin to rely on their ability to scavenge for acetate. This review explains why, when, and how cells excrete or dissimilate acetate. The central components of the “switch” (phosphotransacetylase [PTA], acetate kinase [ACK], and AMP-forming acetyl coenzyme A synthetase [AMP-ACS]) and the behavior of cells that lack these components are introduced. Acetyl phosphate (acetyl∼P), the high-energy intermediate of acetate dissimilation, is discussed, and conditions that influence its intracellular concentration are described. Evidence is provided that acetyl∼P influences cellular processes from organelle biogenesis to cell cycle regulation and from biofilm development to pathogenesis. The merits of each mechanism proposed to explain the interaction of acetyl∼P with two-component signal transduction pathways are addressed. A short list of enzymes that generate acetyl∼P by PTA-ACKA-independent mechanisms is introduced and discussed briefly. Attention is then directed to the mechanisms used by cells to “flip the switch,” the induction and activation of the acetate-scavenging AMP-ACS. First, evidence is presented that nucleoid proteins orchestrate a progression of distinct nucleoprotein complexes to ensure proper transcription of its gene. Next, the way in which cells regulate AMP-ACS activity through reversible acetylation is described. Finally, the “acetate switch” as it exists in selected eubacteria, archaea, and eukaryotes, including humans, is described.
Signaling by Target of Rapamycin Proteins in Cell Growth Control
Authors: Inoki Ken , Ouyang Hongjiao , Li Yong , Guan Kun-Liang 
Published: March 2005

SUMMARY
Target of rapamycin (TOR) proteins are members of the phosphatidylinositol kinase-related kinase (PIKK) family and are highly conserved from yeast to mammals. TOR proteins integrate signals from growth factors, nutrients, stress, and cellular energy levels to control cell growth. The ribosomal S6 kinase 1 (S6K) and eukaryotic initiation factor 4E binding protein 1(4EBP1) are two cellular targets of TOR kinase activity and are known to mediate TOR function in translational control in mammalian cells. However, the precise molecular mechanism of TOR regulation is not completely understood. One of the recent breakthrough studies in TOR signaling resulted in the identification of the tuberous sclerosis complex gene products, TSC1 and TSC2, as negative regulators for TOR signaling. Furthermore, the discovery that the small GTPase Rheb is a direct downstream target of TSC1-TSC2 and a positive regulator of the TOR function has significantly advanced our understanding of the molecular mechanism of TOR activation. Here we review the current understanding of the regulation of TOR signaling and discuss its function as a signaling nexus to control cell growth during normal development and tumorigenesis.
Glucose production and substrate cycle activity in a fasting adapted animal, the northern elephant seal
Authors: Champagne Cory D. , Houser Dorian S. , Crocker Daniel E. 
Published: March 2005

SUMMARYDuring prolonged fasting physiological mechanisms defend lean tissue from catabolism. In the fasting state, glucose is derived solely from gluconeogenesis, requiring some catabolism of amino acids for gluconeogenic substrates. This creates a conflict in animals undergoing fasts concurrently with metabolically challenging activities. This study investigated glucose metabolism in fasting and developing neonatal elephant seals. Glucose production and glucose cycle activity were measured early (2 weeks) and late(6 weeks) in the postweaning fasting period. Additionally the role of regulatory hormones on glucose production and glucose cycle activity were investigated. Glucose cycle activity was highly variable throughout the study period, did not change over the fasting period, and was not correlated with insulin or glucagon level. Endogenous glucose production (EGP) was 2.80±0.65 mg kg–1 min–1 early and 2.21±0.12 during late fasting. Insulin to glucagon molar ratio decreased while cortisol levels increased over the fast (t=5.27,2.84; P=0.003, 0.04; respectively). There was no relationship between EGP and hormone levels. The glucose production values measured in this study were high and exceeded the estimated gluconeogenic substrate available. These data suggest extensive glucose recycling via Cori cycle activity occurring in northern elephant seals, and we propose a possible justification for this recycling.
Contextual effects of small environments on the electric images of objects and their brain evoked responses in weakly electric fish
Authors: Pereira Ana Carolina , Centurión Viviana , Caputi Angel Ariel 
Published: March 2005

SUMMARYThis article reports some contextual effects of fish hovering in small environments on active imaging. Foveal electrosensory images of objects and their corresponding evoked responses in the electrosensory lobe are altered in amplitude and waveform when the fish are inside tubes. The article describes:(i) the physical basis of the changes imposed by small environments on electric images, (ii) the field potential responses at the electrosensory lobe of chronically implanted animals when entering and leaving tubes, and (iii)the effect of context on object discrimination. Biophysical analysis indicates that tubes cause a change in the efficiency of a previously described pre-receptor/post-effector mechanism responsible for the electric`illumination' of nearby objects (as mirrors change the illumination of visual scenes). Field potential responses at the electrosensory lobe showed two components corresponding to the fast- and slow-electrosensory pathways respectively: (a) an early spike following the input without adaptation; (b) a series of waves lasting the rest of the cycle and exhibiting different degrees of adaptation. Discrimination experiments showed that fish react to changes in image rather than to changes in object resistance. The amplitude of the novelty responses evoked by similar changes in the total energy of electric images was constant despite the large change in basal stimulus amplitude and waveform caused by hovering in the tubes. These facts may be explained by the presence of adaptive responses observed at the slow pathway in the electrosensory lobe.
UV incites diverse levels of DNA breaks in different cellular compartments of a branching coral species
Authors: Baruch Rinkevich , Avishai Nanthawan , Rabinowitz Claudette 
Published: March 2005

SUMMARY
This study evaluates in vitro the effects of UVB irradiation on three cellular compartments of a shallow water coral species. Coral tissues were dissociated by Ca2+-Mg2+-free artificial seawater. Cell suspensions were divided into the major cellular compartments (animal cells, algal cells, holobiont entities) by sucrose gradient and then by detergent treatments. Cell fractions were irradiated by UVB lamp (4.05, 8.1 and 12.2 kJ m–2) and subjected to the comet assay. UVB radiation, at levels that induced a moderate DNA breakage to the non-symbiotic coral and algal cell compartments, caused dramatic increase in DNA breakage to the holobiont entities. After a 1 h repair period, DNA breakage levels in the algal and animal cell fractions were augmented as compared with a reduction in DNA breakage in the holobiont fraction. This discordancy in DNA breakage between the three cellular compartments reveals that the holobiont cell fraction is more vulnerable to increased natural UV irradiation and associated anthropogenic genotoxic impacts, providing another possible explanation for recent increase in worldwide coral bleaching events.
Effects of levothyroxine treatment on biochemical and hemostasis parameters in patients with hypothyroidism
Authors: Gullu Sevim , Sav Hasan , Kamel Nuri 
Published: March 2005

Objective: The aims of the study were to evaluate the disturbances in the coagulation system in patients with overt hypothyroidism (OH), to assess the effects of levothyroxine (LT4) on the coagulation parameters, and to determine whether subclinical hypothyroidism (SH) affects concentrations of coagulation markers and several biochemical parameters, thereby supporting early substitution.Design: The study included 15 patients with SH (TSH levels 5–10 mU/l), 15 patients with OH and 15 euthyroid controls.Methods: Blood urea nitrogen, creatinine, creatine phosphokinase, aspartate aminotransferase, lactate dehydrogenase, total-cholesterol, high density lipoprotein-cholesterol, low density lipoprotein-cholesterol and triglyceride levels, and bleeding time, prothrombin time (PT), activated partial thromboplastin time (APTT), factor VIII activity, von Willebrand factor activity (vWF), platelet count and clotting time were evaluated just before and three months after the maintenance of euthyroidism with LT4 treatment.Results: Factor VIII and vWF activities were lower in patients with SH than in controls (P< 0.01). Increased bleeding time, PT, APTT and clotting time and decreased factor VIII activity and vWF activity were observed in patients with OH when compared with controls. Bleeding time, PT, APTT and clotting time decreased and factor VIII activity, vWF and platelet count increased after LT4 in patients with OH. Increases in factor VIII activity and vWF (P< 0.01) were detected also in the SH group with treatment.Conclusions: OH is associated with significant abnormalities in clotting parameters which are reversed by LT4. In contrast, SH is associated with minor changes in factor VIII activity and vWF which are reversible by LT4. Serum lipids and other measured parameters are not improved by LT4 in patients with TSH < 10 mU/l and these data fail to demonstrate a need to treat such patients.
Androgen receptor gene CAG and GGC repeat lengths in cryptorchidism
Authors: Ferlin Alberto , Garolla Andrea , Bettella Andrea , Bartoloni Lucia , Vinanzi Cinzia , Roverato Alberto , Foresta Carlo 
Published: March 2005

Objective: Cryptorchidism is the most common congenital birth defect in male children, and accumulating evidence suggests that genetic abnormalities may be associated with it. The androgen receptor has two polymorphic sites in exon 1, with different numbers of CAG and GGC repeats, resulting in variable lengths of polyglutamine and polyglycine stretches. Longer CAG repeats result in a reduced androgen receptor transcriptional activity, but the role of the GGC triplets is less clear. In this study we analysed CAG and GGC repeat lengths in men with a history of cryptorchidism, associated or not with impairment of sperm production, in comparison with normal fertile subjects.Methods: We analysed CAG and GGC repeat lengths in a group of 105 ex-cryptorchid men in comparison with 115 fertile non-cryptorchid men.Results: No difference was found between patients and controls in the mean and median values, and in distribution of CAG and GGC, when considered separately. However, the analysis of the joint distribution of CAG and GGC showed that some combinations are significantly more frequent in men with bilateral cryptorchidism (who frequently presented severe testiculopathies), in a manner similar to that found in idiopathic infertile subjects.Conclusions: Although further studies are needed to elucidate the possible role of specific CAG/GGC combinations as a causative factor, these data suggest a possible association between androgen receptor gene polymorphisms and cryptorchidism.
Evidence for altered adipocyte function in polycystic ovary syndrome
Authors: Carmina E , Orio F , Palomba S , Cascella T , Longo R A , Colao A M , Lombardi G , Lobo R A 
Published: March 2005

Background: Adipocytokines are produced by adipose tissue and have been thought to be related to insulin resistance and other health consequences. We measured leptin, adiponectin, and resistin simultaneously in women with polycystic ovary syndrome (PCOS) and age- and weight-matched controls. Our hypothesis was that these simultaneous measurements would help determine whether adipocytokine secretion is abnormal in PCOS independent of body mass and whether these levels are related to insulin resistance as well as other hormonal changes.
Methods: Fifty-two women with PCOS and 45 normal ovulatory women who were age- and weight-matched were studied. Blood was obtained for adipocytokines (leptin, adiponectin, and resistin) as well as hormonal parameters and markers of insulin resistance as assessed by the quantitative insulin-sensitivity check index. Body mass index (BMI) was stratified into obese, overweight, and normal subgroups for comparisons between PCOS and controls.
Results: Adiponectin was lower (P < 0.05) and resistin was higher (P < 0.05) while leptin was similar to matched controls. Breakdown of the groups into subgroups showed a strong body mass relationship for leptin with no changes in resistin although adiponectin was lower in PCOS, even controlling for BMI. In controls, leptin and adiponectin and leptin and resistin correlated (P < 0.05) but not in PCOS. In controls, all adipocytokines correlated with markers of insulin resistance but not in PCOS.
Conclusions: When matched for BMI status, decreased adiponectin in PCOS represent the most marked change. This alteration may be the result of altered adipose tissue distribution and function in PCOS but no correlation with insulin resistance was found.
Serum markers of GH and insulin action in 12-year-old children born small for gestational age
Authors: Tenhola Sirpa , Halonen Pirjo , Jääskeläinen Jarmo , Voutilainen Raimo 
Published: March 2005

Objectives: Our aim was to determine whether markers of growth hormone and insulin action differ between children born small for gestational age (SGA) and those born of an appropriate size for gestational age (AGA).
Design: Fifty-five SGA children and their 55 age- and sex-matched AGA control subjects were studied in a case-control setting at 12 years of age.
Methods: We examined serum concentrations of insulin-like growth factor (IGF)-I, IGF-II, IGF-binding protein (IGFBP)-1 and IGFBP-3, sex hormone binding globulin (SHBG), leptin, fasting insulin, and blood glucose. Insulin sensitivity was evaluated by the homeostasis model assessment for insulin resistance (HOMA-IR).
Results: The body mass index (BMI), sex, and puberty-adjusted mean serum IGF-I concentration was higher in the SGA than in the AGA children (303.4 vs 282.3 μg/l, P = 0.006). The mean serum concentrations of IGF-II, IGFBP-I, IGFBP-3, SHBG, fasting insulin, blood glucose and HOMA-IR did not differ between the SGA and the AGA group. The BMI, sex, and puberty-adjusted mean serum leptin concentration was lower in the SGA than in the AGA children (7.9 vs 10.1 μg/l, P = 0.037). In multiple logistic regression analysis, high HOMA-IR predicted high serum IGF-I levels in the SGA children (odds ratio 8.3; 95% confidence interval 1.7–41; P = 0.010), whereas in the AGA group HOMA-IR did not associate with the serum IGF-I level.
Conclusions: The BMI, sex, and puberty-adjusted mean serum IGF-I concentration was significantly higher and the leptin concentration was lower in the SGA than in the AGA children. No differences were found in the indices of insulin action or sensitivity between the SGA and AGA children at 12 years of age. However, HOMA-IR strongly associated with serum IGF-I levels in the SGA children.
Ordered‐subset analysis of savant skills in autism for 15q11‐q13
Authors: Ma D.Q. , Jaworski J. , Menold M.M. , Donnelly S. , Abramson R.K. , Wright H.H. , Delong G.R. , Gilbert J.R. , Pericak‐Vance M.A. , Cuccaro Michael L. 
Published: March 2005

AbstractAutism is a complex disorder characterized by genetic and phenotypic heterogeneity. Analysis of phenotypically homogeneous subtypes has been used to both confirm and narrow potential autism linkage regions such as the chromosomal region 15q11‐q13. Increased evidence for linkage in this region had been found in a subgroup of 21 autism families (total families = 94) stratified based on a savant skill factor (SSF) from the Autism Diagnostic Interview, Revised (ADI‐R). We examined the savant phenotypic finding in our sample of 91 multiplex autism families. Using two‐point parametric analysis in stratification with a cutoff point of a savant skill score of 0.16, our families failed to demonstrate linkage to 15q11‐q13. In addition, ordered subset analysis (OSA) using SSF as a covariate also failed to show evidence for linkage. Our findings do not support savant skills as an informative phenotypic subset for linkage in our sample. © 2005 Wiley‐Liss, Inc.