bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological, nanomechanical and cellular structural characterization of human hair and conditioner distribution using torsional resonance mode with an atomic force microscope
Authors: CHEN N. , BHUSHAN B. 
Published: November 2005

SummaryCharacterization of the cellular structure and chemical and physical properties of hair are essential to develop better cosmetic products and advance the biological and cosmetic sciences. Although the morphology of the fine cellular structure of human hair has traditionally been investigated using scanning electron microscopy and transmission electron microscopy, atomic force microscopy can be used for characterization in ambient conditions without requiring specific sample preparations and surface treatment. In this study, the tapping and torsional resonance modes in an atomic force microscope are compared for measurements of stiffness and viscoelastic properties. The materials were mapped using amplitude and phase angle imaging. The torsional resonance mode showed advantages in resolving the in‐plane (lateral) heterogeneity of materials. This mode was used for investigating and characterizing the fine cellular structure of human hair. Various cellular structures (such as the cortex and the cuticle) of human hair and fine sublamellar structures of the cuticle, such as the A‐layer, the exocuticle, the endocuticle and the cell membrane complex were easily identified. The distribution and thickness of conditioner on the treated hair surface affects the tribological properties of hair. The thickness of the conditioner was estimated using force distance measurements with an atomic force microscope.
Destruction of polymer growth substrates for cell cultures in two‐photon microscopy
Authors: THIBAUD C. , KOUBASSOV V. , DE KONINCK P. , CHIN S. L. , DE KONINCK Y. 
Published: November 2005

SummaryThe choice of the growth substrate for cell cultures used in fluorescence microscopy is guided by several factors including the type of cells studied and the type of microscopy used. Usually, cells can be cultured on either polymer or glass substrates. One type of polymer, termed Aclar, presents several attractive features: the adhesive properties are better than those of glass, the optical properties are comparable to those of glass, it is biochemically inert, unbreakable, flexible and has a high surface tension, convenient for seeding cells on the cover slip. However, here we show that when imaging with two‐photon microscopy, which is based on a femtosecond pulsed laser source, local damage of the Aclar substrate occurs, starting at an average intensity of 105 W cm−2 at the focal point and for exposure times insufficient to cause cell damage. This leads to the appearance of gas bubbles on cultures plated on Aclar cover slips, which perturb the imaging. By contrast, this phenomenon does not occur on borosilicate cover slips, probably because of their different physical (thermal conductivity, absorbance, melting point) and material homogeneity properties. Thus, for cell culture applications using pulsed lasers with high intensities, the use of glass is preferable to Aclar. The results also reveal that substrates can be more susceptible to thermal damage than the cells themselves.
Transpiration‐assisted perfusion fixation provides in situ preservation of developing ray parenchyma cells in Eucalyptus nitens
Authors: WILSON L. , TONKIN M. , BOSSINGER G. 
Published: November 2005

SummaryThe technique of animal vascular perfusion fixation was adapted for in situ fixation of the fragile and difficult to access cells of the ray parenchyma system in stems of 10‐year‐old Eucalyptus nitens trees. In situ fixation enabled tissue to be safely dissected for histological processing without risk of damage to microstructure or initiation of wound response. Fixative was perfused through the active vascular system under hydrostatic and transpiration pressure directly to vessel‐associated ray cells. Diffusion from vessels allowed fixative to access nonvessel‐associated ray cells. Acrolein was included to aid diffusion fixation and safranin dye was included to define fixed regions within the xylem. Sections prepared for light and electron microscopy from samples cut from regions showing intense safranin staining showed good microstructural preservation and were free of artefacts caused by mechanical injury or wound response.
Specific and Time‐Dependent Effects of Glucocorticoid Receptor Agonist RU28362 on Stress‐Induced Pro‐Opiomelanocortin hnRNA, c‐fos mRNA and zif268 mRNA in the Pituitary
Authors: Ginsberg A. B. , Frank M. G. , Francis A. B. , Rubin B. A. , O'Connor K. A. , Spencer R. L. 
Published: November 2005

AbstractThis study examined the effects of the glucocorticoid receptor (GR) agonist RU28362 on stress‐induced gene expression in the pituitary of rats to investigate mechanisms of glucocorticoid negative feedback in vivo. In an initial experiment, acute restraint stress produced rapid (within 15 min) induction of c‐fos mRNA, zif268 mRNA and pro‐opiomelanocortin (POMC) hnRNA within the anterior and intermediate/posterior pituitary as determined by quantitative real‐time polymerase chain reaction. Treatment with RU28362 (150 µg/kg, i.p.) 60 min before restraint inhibited adrenocorticotrophic hormone (ACTH) and corticosterone secretion and selectively suppressed the stress‐induced increase in POMC hnRNA in the anterior pituitary gland. The failure of RU28362 to surpress the stress‐induced rise in c‐fos and expression of zif268 mRNA suggests that the central release of ACTH secretagogues was not affected at this time point by treatment with the GR agonist. Rather, the inhibition of ACTH release appeared to be due to a direct effect of RU28362 within the pituitary. A follow‐up time‐course study varied the interval (10, 60 or 180 min) between RU28362 pretreatment and the onset of restraint. The stress‐induced increase in POMC hnRNA was completely blunted by RU28362 treatment within 10 min of treatment, although the stress induced hormone secretion, c‐fos mRNA and zif268 mRNA were unaffected. The rapid inhibition of the stress‐induced rise in POMC hnRNA in the anterior pituitary appears to reflect direct, GR‐mediated suppression of POMC gene expression. RU28362 pretreatment 180 min before restraint onset was sufficient to suppress the stress‐induced expression in the anterior pituitary gland of all three genes examined. Thus, the delayed negative feedback effects on hypothalamic‐pituitary‐adrenal axis activity that emerged after 180 min after glucocorticoid treatment were not evident at 60 min. Taken together, the data suggest that the inhibition of the stress‐induced release of ACTH apparent within the first hour of glucocorticoid exposure is effected at the level of the pituitary gland. The delayed glucocorticoid effects evident 180 min after RU28362 treatment may include glucocorticoid actions in the brain and additional actions within the pituitary.
Evidence for a Stimulatory Action of Melanin‐Concentrating Hormone on Luteinising Hormone Release Involving MCH1 and Melanocortin‐5 Receptors
Authors: Murray J. F. , Hahn J. D. , Kennedy A. R. , Small C. J. , Bloom S. R. , Haskell‐Luevano C. , Coen C. W. , Wilson C. A. 
Published: November 2005

AbstractThe present series of studies aimed to further our understanding of the role of melanin‐concentrating hormone (MCH) neurones in the central regulation of luteinising hormone (LH) release in the female rat. LH release was stimulated when MCH was injected bilaterally into the rostral preoptic area (rPOA) or medial preoptic area (mPOA), but not when injected into the zona incerta (ZI), of oestrogen‐primed ovariectomised rats. In rats that were steroid‐primed to generate a surge‐like release of LH, MCH administration into the ZI blocked this rise in LH release: no such effect occurred when MCH was injected into the rPOA or mPOA. In vitro, MCH stimulated gonadotrophin‐releasing hormone (GnRH) release from hypothalamic explants. Double‐label immunohistochemistry showed GnRH‐immunoreactive neurones in the vicinity of and intermingled with immunoreactive MCH processes. MCH is the endogenous ligand of the MCH type 1 receptor (MCH1‐R). Previously, we have shown a role for melanocortin‐5 receptors (MC5‐R) in the stimulatory action of MCH, so we next investigated the involvement of both MCH1‐R and/or MC5‐R in mediating the actions of MCH on GnRH and hence LH release. The stimulatory action of MCH in the rPOA was inhibited by administration of antagonists for either MCH1‐R or MC5‐R. However, in the mPOA, the action of MCH was blocked only by the MC5‐R antagonist. LH release was stimulated by an agonist for MC5‐R injected into the rPOA or mPOA; this was blocked by the MC5‐R antagonist but not the MCH1‐R antagonist. These results indicate that both MCH1‐R and MC5‐R are involved in the central control of LH release by MCH.
Efficient analysis in planet transit surveys
Authors: Schwarzenberg-Czerny A. , Beaulieu J.-Ph. 
Published: November 2005

Abstract
With the growing number of projects dedicated to the search for extrasolar planets via transits, there is a need to develop fast, automatic, robust methods with a statistical background in order to carry out the analysis efficiently. We propose a modified analysis of variance (AoV) test particularly suitable for the detection of planetary transits in stellar light curves. We show how labour savings of a factor of over 10 could be achieved by the careful organization of computations. Based on solid analytical statistical formulations, we discuss the performance of our and other methods for different signal-to-noise ratios and numbers of observations.
Enhanced salt tolerance mediated by AtHKT1 transporter‐induced Na+ unloading from xylem vessels to xylem parenchyma cells
Authors: Sunarpi  , Horie Tomoaki , Motoda Jo , Kubo Masahiro , Yang Hua , Yoda Kinya , Horie Rie , Chan Wai‐Yin , Leung Ho‐Yin , Hattori Kazumi , Konomi Mami , Osumi Masako , Yamagami Mutsumi , Schroeder Julian I. , Uozumi Nobuyuki 
Published: November 2005

SummaryAtHKT1 is a sodium (Na+) transporter that functions in mediating tolerance to salt stress. To investigate the membrane targeting of AtHKT1 and its expression at the translational level, antibodies were generated against peptides corresponding to the first pore of AtHKT1. Immunoelectron microscopy studies using anti‐AtHKT1 antibodies demonstrate that AtHKT1 is targeted to the plasma membrane in xylem parenchyma cells in leaves. AtHKT1 expression in xylem parenchyma cells was also confirmed by AtHKT1 promoter–GUS reporter gene analyses. Interestingly, AtHKT1 disruption alleles caused large increases in the Na+ content of the xylem sap and conversely reduced the Na+ content of the phloem sap. The athkt1 mutant alleles had a smaller and inverse influence on the potassium (K+) content compared with the Na+ content of the xylem, suggesting that K+ transport may be indirectly affected. The expression of AtHKT1 was modulated not only by the concentrations of Na+ and K+ but also by the osmolality of non‐ionic compounds. These findings show that AtHKT1 selectively unloads sodium directly from xylem vessels to xylem parenchyma cells. AtHKT1 mediates osmolality balance between xylem vessels and xylem parenchyma cells under saline conditions. Thus AtHKT1 reduces the sodium content in xylem vessels and leaves, thereby playing a central role in protecting plant leaves from salinity stress.
The time‐dependent effect of gluconasturtiin and phenethyl isothiocyanate on metabolic and antioxidative parameters in rats
Authors: Okulicz M. , Bialik I. , Chichłowska J. 
Published: November 2005

SummaryThe effect of gluconasturtiin (GNST) and phenethyl isothiocyanate (PEITC) on some metabolic changes and antioxidative parameters in the rat was tested using different doses of PEITC and duration of GNST or PEITC ingestion. Their effect on antioxidative processes was previously observed, however, their influence on metabolic changes is still poorly characterized. In the performed experiment, the effect of GNST (0.5 mg/kg BW) and PEITC (0.1 mg/kg BW or 0.3 mg/kg BW) administered intragastrically after 4 h or 14 days to growing male rats was studied. PEITC at both doses after 4 h of its administration caused a considerable increase in liver cholesterol and triglyceride content with a concomitant drop in the amount of glycogen. Blood glucose, free fatty acids, phospholipids and total, free, esterified cholesterol as well as cholesterol in high‐density lipoprotein were not altered. GNST, at its short‐time ingestion, augmented significantly the concentration of triglycerides in blood serum. The compounds tested had no influence on metabolic changes after a longer period of action with the exception of glycogen values in liver, which were substantially augmented by PEITC at both doses. Our trial revealed a lack of GNST and PEITC influence on the content of liver sulphhydryl groups and on glutathione peroxidase and glutathione‐S‐transferase activities. The only distinct change in the content of malonodialdehyde was observed after short‐time action of lower dose of PEITC. Our research showed that the short‐term PEITC action constituted a significant factor interfering with liver metabolism. Although PEITC has been repeatedly advocated as very promising anticancer agent, in our experiment, the lower dose of PEITC was revealed as a pro‐oxidative substance. These inconsistent properties seem to depend on its dose and time of action.
Effect of sodium phytate supplementation on fat digestion and cholesterol metabolism in female rats
Authors: Yuangklang C. , Wensing Th. , Lemmens A. G. , Jittakhot S. , Beynen A. C. 
Published: November 2005

SummaryThe effects of sodium phytate supplementation on fat digestion and cholesterol metabolism were investigated in female rats. On the basis of an in vitro experiment showing that phytate raised the solubility of bile acids, it was predicted that phytate feeding would depress faecal bile acid excretion, raise apparent fat digestibility and elevate serum cholesterol concentrations. The experimental diets with or without sodium phytate were either cholesterol‐free or cholesterol‐rich and had a normal calcium concentration. Rats fed on the cholesterol‐rich diet with sodium phytate showed enhanced faecal bile acid excretion, but there was no effect on fat digestibility. In rats fed the cholesterol‐free diets, phytate did neither affect fat digestion nor bile acid excretion. Sodium phytate inclusion in the cholesterol‐rich diet raised serum cholesterol concentrations, but reduced liver cholesterol concentration. Thus, the in vivo data do not agree with the in vitro observations. Both phytate and cholesterol feeding influenced mineral and trace element metabolism. Liver zinc concentrations were raised by phytate feeding. Cholesterol consumption reduced hepatic concentrations of copper, iron and zinc. Both phytate and cholesterol feeding reduced the apparent absorption of calcium, magnesium and phosphorus.
Vitamin A nutrition of growing cockatiel chicks (Nymphicus hollandicus)
Authors: Koutsos E. A. , Klasing K. C. 
Published: November 2005

SummaryThe experiments examined the physiological response of growing cockatiel chicks to varying levels of dietary vitamin A (VA) or β‐carotene and the rate of liver VA uptake. Adult cockatiels breeding pairs (n = 10 pairs) were fed a VA‐deficient diet for approximately 90 days prior to onset of egg laying. Breeding pairs were then allowed to feed their chicks diets containing either 0 IU VA/kg, 4000 IU VA/kg, or 2.4 mg β‐carotene/kg. After 5 weeks, chicks fed 0 IU VA developed poor feathering, facial dermatitis and reduced body weight (p < 0.05). Liver VA was higher in chicks fed 4000 IU VA or 2.4 mg β‐carotene vs. those fed 0 IU VA (p < 0.05). Duodenal β‐actin and 15,15′‐dioxygenase mRNA expression was similar to that of growing chickens, and greatest for cockatiel chicks fed 0 IU VA (p < 0.01). Chicks fed 0 IU VA had keratinization of the bursa and oral mucosa, and reduced bursa development and lymphocyte density (p < 0.05). Finally, when chicks fed 0 IU VA were orally gavaged with 20 IU VA/g body weight, maximal liver retinol uptake occurred between 0 and 24 h and reached a plateau at 36 h. These data demonstrate that VA deficiency can be prevented with 4000 IU VA/kg diet or 2.4 mg β‐carotene/kg diet, although β‐carotene conversion to VA may be lower in cockatiels than chickens.
Precaecal and faecal digestibility of inulin (DP 10–12) or an inulin/Enterococcus faecium mix and effects on nutrient digestibility and microbial gut flora
Authors: Böhmer B. M. , Branner G. R. , Roth‐Maier D. A. 
Published: November 2005

SummaryThe aim of the present study was to investigate the precaecal and faecal digestibility of inulin (DP 10–12) and inulin/Enterococcus faecium mix, and the effects of these substances on nutrient digestibility and microbial gut flora. For the experiment four of eight male pigs were fitted with an end‐to‐end ileo‐rectal anastomosis (IRA) with preserved ileo‐caeco‐colic valve. The residual pigs were used as intact partner (IN). The animals received 1.5 kg/day of a diet based on corn, wheat, barley and soybean meal, supplemented with either 8 × 109 CFU E. faecium/kg, 2% inulin or a mixture of both substances. The digestibility trial was carried out from weeks 4 to 8 after surgery. Precaecal digestibility of inulin was assessed to be 57%. The addition of E. faecium to the diet resulted in a similar precaecal digestibility of inulin of 55%. Supplementation of E. faecium, inulin, and a mixture of E. faecium and inulin did not affect precaecal and faecal nutrient digestibility with the exception of the precaecal digestibility of CF which increased when inulin alone was supplemented. Bacterial population in the digesta of IRA and IN pigs were not affected by the experimental diets except the concentration of bifidobacteria and lactobacilli. The supplementation of E. faecium to the diet significantly decreased the concentration of bifidobacteria and the population of lactobacilli inclined to decrease when IN pigs received the probiotic diet. The combination of E. faecium and inulin prevented a reduction of enterococci in faeces of IN pigs. The daily digesta excretion (DM) tended to decrease in IRA and IN pigs when inulin was supplemented. The results indicate that inulin (DP 10–12) in pig nutrition did partly react as a prebiotic as has been confirmed for humans. A combination of E. faecium and inulin improves the survival of the probiotic strain through the upper intestinal tract and allocates the synbiotic effect. Furthermore inulin might be able to show positive effects on precaecal and faecal microbial characteristics.
Phytic acid–induced metabolic changes in the rat
Authors: Szkudelski T. 
Published: November 2005

SummaryPhytic acid (PA) is present in considerable amounts in the seeds of many plant species consumed by animals. Little is known about its influence on metabolic processes. In the performed experiment the effect of rats feeding a standard laboratory diet (Murigran) with increasing supplements of PA on some hormones and biochemical parameters was tested. Male Wistar rats were divided into five groups of eight animals each. In the first group (control) rats were fed a diet without any supplement whereas the groups II–V received food with added PA: 0.1, 0.2, 0.3 and 1%. After 20 days animals were decapitated, blood serum, liver and tight muscles were sampled. In rats fed a diet enriched in PA the concentration of thyroid hormones was diminished. Simultaneously, T3/T4 ratio was slightly reduced. These changes were accompanied by a rise in blood glucose level and an augmentation in liver and muscle glycogen stores and were found in spite of unchanged blood insulin. Consumption of food with increased amounts of PA resulted in a substantial reduction of liver triglyceride content, but serum triglycerides were not affected. In rats from groups II and III serum free‐fatty acids concentration was reduced. However, in animals receiving highest PA supplement this effect was not observed. Serum calcium and magnesium were not affected by PA. Serum iron was significantly reduced, but only in rats on the highest supplement of the tested compound. Results obtained in this experiment clearly indicate that the PA is able to induce hormonal and metabolic changes in animals. These changes seem to result not only from reduced bioavailability of minerals but also from interactions of PA with nutrients and enzymes in the liver.
Comparing two commercial enzymes to estimate in vitro proteolysis of purified or semi‐purified proteins
Authors: Chaudhry A. S. 
Published: November 2005

SummaryTwo experiments compared the suitability of two commercial enzymes to estimate in vitro proteolysis of different proteins. Experiment 1 compared the proteolytic activity over various incubation times of a microbial enzyme (protease from Streptomyces griseus) with a plant enzyme (papain from Papaya latex) by using either 1.33 (high, H) or 0.4 (low, L) units (U, amount) of each enzyme per mg crude protein (CP) of purified proteins including bovine (BA) or egg albumin (EA). Experiment 2 compared the activity of 0.66 U of each of these enzymes per mg CP of semi‐purified proteins including casein, wheat gluten (WG) and maize gluten meal (MG). Each incubation was terminated by adding trichloroacetic acid (TCA) and the TCA soluble supernatant collected to estimate concentration of total amino acids (AA) as the measure of proteolysis of each protein over each time. The data on proteolysis over time were fitted into a non‐linear model to derive constants for solubility (a) and rate (c) and extents (a + b) of proteolysis of each food by each amount of each enzyme. All data on proteolysis over time and the derived constants were statistically analysed to study the effect of food, enzyme, amount and their interactions. Significant differences were observed between foods, enzymes, enzyme amount (H vs. L for Experiment 1 only) for the proteolysis at most incubation times in both experiments (p < 0.001). The mean proteolysis over all times for BA was 1.6 (SD, 0.52) times greater than EA (p < 0.001). While the protease gave about four times (SD, 2.1) more proteolysis than papain (p < 0.001), the high amount of enzyme gave only about two times (SD, 0.28) greater proteolysis than that of the low amount (p < 0.001). On average, the protease was over three times faster (c) than papain (p < 0.001) and high amount was two times faster than the low amount of enzyme (p < 0.001). While both purified foods were similar in solubility (p > 0.05), they differed in the rate and extent of proteolysis (p < 0.001). The BA was degraded about four times faster than EA (p < 0.001). Amongst semi‐pure proteins, casein gave the highest but MG the lowest proteolysis at each incubation (p < 0.001). However, the magnitude of proteolysis depended upon enzyme, food and hours of incubation. On average, casein was degraded at a much faster rate than WG or MG by both enzymes. It appeared that the protease and not papain can be used to estimate in vitro proteolysis of pure and semi‐pure food proteins. However, further studies are needed to standardise the relevant procedures when using protease to estimate proteolysis of ruminant foods.