bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cardiovascular risk factors and electrographical characteristics and abnormalities in middle‐aged males
Authors: LIND L. , SUNDSTRÖM J. , LITHELL H. 
Published: November 2003

Objectives. To evaluate if characteristics and abnormalities found at the electrocardiogram (ECG) are related to common cardiovascular risk factors included in the insulin‐resistance metabolic syndrome. Design. Cross‐sectional. Setting. Tertiary university hospital. Subjects. Over 2000 middle‐aged males in whom ECG abnormalities were recorded, together with ECG characteristics measured in a random sample of men with no ECG abnormalities (n=113). Interventions. None. Results. All three components of the metabolic syndrome; elevated blood pressure, dyslipidaemia and hyperinsulinaemia were found to be related to the heart rate (P<0.002) and the QRS‐duration (P<0.01) and inversely to the QoT‐interval (P<0.05), the early diastolic phase (P<0.05) and the T‐wave amplitude (P<0.02). The components of the metabolic syndrome was furthermore found to be associated with the occurrence of T‐wave abnormalities (n=64, P<0.01) and to a lesser degree also to the occurrence of Q‐waves (n=21). Conclusions. The components of the insulin‐resistance metabolic syndrome were related both to certain ECG characteristics in subjects with a normal ECG and to some ECG abnormalities. A raised sympathetic activity is likely to be the link between some of the described associations, whilst coronary heart diseases may explain others.
Influence of menopause on blood cholesterol levels in women: the role of body composition, fat distribution and hormonal milieu
Authors: PASQUALI R. , CASIMIRRI F. , PASCAL G. , TORTELLI O. , MORSELLI LABATE A. M. , BERTAZZO D. , VICENNATI V. , GADDI A. , Virgilio Menopause Health Group  
Published: November 2003

Objectives. In this study we investigated the relationships between blood lipids and menopausal status. Setting and subjects. All data were obtained from the first cross‐sectional examination of the Virgilio Menopause Health Project in a large cohort of middle‐aged women in pre, peri‐, and postmenopausal age. The data refer to 426 women without metabolic or endocrine diseases, relevant hepatic, renal and cardiovascular abnormalities, none were dieting or taking medications. Main outcome measures. A precoded questionnaire including full clinical history, socio‐economic and personal information, habitual diet, physical activity, drug use and smoking habits, careful recording of gynaecological events and family history for disease was completed. Several anthropometric parameters and the bioelectrical impedance analysis was used to measure free fatty mass. Blood samples for hormones and biochemistry were also obtained. Results. There were no significant differences on body mass index, fatty mass, free fatty mass and parameters of body fat distribution between the three groups. Again, there were no differences in smoking habits, dietary intake or indices of physical activity amongst the groups. There was a significant increase from pre to postmenopause of LH and FSH and a decrease of oestradiol and testosterone, whereas no difference was found in sex hormone‐binding globulin. Age‐adjusted values of glucose, triglycerides and high density lipoprotein (HDL‐) cholesterol were similar in all groups, whereas postmenopausal women had significantly higher values of total and low density lipoprotein (LDL‐) cholesterol. On the contrary, there was a significant fall in insulin levels passing from pre to postmenopause. In multiple regression models, total and LDL‐cholesterol correlated positively with body mass index, waist‐to‐hip ratio and age, and negatively with free fatty mass and oestradiol blood levels. Conclusions. These results are consistent with the hypothesis that menopausal status may have a significant and independent effect in determining increased total and LDL‐cholesterol concentrations in postmenopausal women.
On the detection of MX‐precipitates in microalloyed steels using energy‐filtering TEM
Authors: Hofer F. , Warbichler P. , Buchmayr B. , Kleber S. 
Published: November 2003

The properties of microalloyed steels and HSLA steels depend predominantly on the size and composition of nanometre‐sized MX precipitates consisting of Nb, Ti, V, C and N. In this work we present a rapid and powerful method for visualizing these small precipitates directly in the steel matrix.This can be achieved by energy‐filtering TEM in a 200‐kV microscope. We have recorded elemental maps (three‐window method) and jump‐ratio images (two‐window method) using the inner‐shell ionization edges; e.g. Fe‐M23, Fe‐L23, V‐M23, V‐L23, Nb‐N23, Nb‐M45, C‐K and N‐K edges. We have found that precipitates in a steel matrix can be best visualized by recording the jump‐ratio image of the matrix element. If the specimens are thinner than 30 nm and high resolution in the images and low detection limits are essential, low energy‐loss edges should be used preferentially; in the case of steels the Fe‐M23 edge should be used instead of the Fe‐L23 edge. If the jump‐ratio images are recorded with the Fe‐M23 edge, precipitates about 2 nm in diameter may be detected. With thicker samples and if high resolution is not as essential, higher energy‐loss edges are preferable, because diffraction effects are less possible.The chemical composition of the larger precipitates (10 nm) could be determined by recording EDX spectra using an STEM probe. We found Nb and V with an atomic ratio of about 3, but we could not detect carbon or nitrogen in the spectra. The Nb and V distribution could be best visualized with a jump‐ratio image including both the Nb‐N23 and the V‐M23 edges. However, it was not possible to image the carbon or nitrogen content of the precipitates unequivocally due to overlapping of the C‐K and N‐K edges with the Nb‐M45 edge.
ESI contrast analysis: a new approach for element analysis with energy‐filtering transmission electron microscopy (EFTEM)
Authors: Körtje K.‐H. 
Published: November 2003

Element microanalysis with energy‐filtering transmission electron microscopy can be performed in different ways. Electron energy‐loss spectroscopy (EELS) records the intensity as a function of the energy loss from selected regions. Elemental mapping with electron spectroscopic imaging (ESI) uses energy‐filtered images at an element‐specific energy loss from which a background image has to be subtracted. A combination of these two approaches is Image‐EELS, which records a series of energy‐filtered images, each at a different energy loss and measures the intensity of selected regions as a function of the energy loss. As an additional procedure ESI contrast analysis is introduced; with this we can investigate the image contrast as a function of the energy loss. The contrast can be measured for the total image or for selected regions as the standard deviation of the grey levels divided by the mean grey level. This procedure is added as a new feature to the existing Image‐EELS program, so that EELS intensity spectra and the contrast can be directly compared. Alternatively, the contrast can be calculated step by step from individually recorded electron spectroscopic images, so that only simple equipment for image analysis is sufficient to realize this new method.Inner shell ionizations produce characteristic, but often weak element edges in energy‐loss spectra which can be detected more sensitively and reliably as a rapid increase in contrast. Regional analysis of the contrast as a function of the energy loss, combination of data from different regions and the possibility to increase the intensity during recording of the images expand the application range of this new analytical method which bridges the gap between ESI and EELS analysis. With ESI contrast analysis it is possible to discriminate between faint element signals and artefacts in elemental mapping.This new approach for element detection is especially advantageous for biological objects which usually contain very small amounts of the interesting elements in heterogeneous and complex objects. As an example, nervous tissue of a fish was analysed after cytochemical precipitation of endogenous calcium.
Extended energy‐loss fine structure spectroscopy of structural modifications in Nd2CuO4−δ at the oxygen K edge
Authors: VAN AKEN P. A. 
Published: November 2003

The discovery of the superconducting electron‐doped compound Nd185Ce015CuO4−δ has stimulated great interest in its micro‐ and crystal structure, since the superconducting properties depend on parameters such as nonstoichiometry, phase composition, heat treatment and microstructure. The work presented herein is focused on the determination of the oxygen environment in the undoped parent compound Nd2CuO4 and in the structural modification Nd2CuO35The analysis of the oxygen K (O 1s) edge extended electron energy‐loss fine structure (EXELFS) of the tetragonal parent compound Nd2CuO4 and of the orthorhombic modification Nd2CuO35 is reported by using electron energy‐loss spectroscopy in combination with transmission electron microscopy. Nd2CuO35 is produced by in situ heating and reduction of Nd2CuO4 in the transmission electron microscope. The EXELFS of the O 1s electron energy‐loss edges is analysed with the classical extended X‐ray absorption fine structure (EXAFS) treatment and compared with ab initio multiple scattering EXAFS calculations for both structural modifications. Highly accurate information on the local atomic environment of the oxygen atoms in Nd2CuO35 is obtained from EXELFS analysis using Nd2CuO4 as a standard. The results are in accordance with the structural data gained from X‐ray diffraction analysis. This applies especially to the more complicated structure of Nd2CuO35 determined recently.
Visualization and electron diffraction on cryosections of stratum corneum: a utopia?
Authors: WIJDEVELD M. M. G. , KOERTEN H. K. , ONDERWATER J. J. M. , PARROTT D. T. , BOUWSTRA J. A. 
Published: November 2003

The skin acts as an effective barrier to protect the body against penetration of substances from the environment and against desiccation. The main barrier function resides in the stratum corneum, and more specifically in the intercellular lipid domains. Several techniques have been used to elucidate the local lipid crystal arrangements in these domains, but they either needed an extensive pretreatment of the skin with the risk of damaging the native structure, or were not suited to obtain local structure information as bulk quantities of stratum corneum were required. In this paper a method of performing local structure analysis (electron diffraction) on cryo‐fixed specimens is described. Therefore a cold chain procedure was used to obtain cryosections of stratum corneum. On these sections visualization and electron diffraction at low temperature were carried out.Using a so‐called tape sandwich method, cryosections were prepared in which corneocytes and lipid matrix could easily be distinguished. Moreover, detailed cellular components such as desmosomes and intracellular lipid domains were observed. However, probably due to the limited amount of intercellular lipids in the stratum corneum, electron diffraction on cryosections did not result in diffraction patterns that were undoubtedly originating from the intercellular lipids. In the electron diffraction patterns of a skin lipid model system reflections were present that were indicative of hexagonal and orthorhombic sublattices. The d‐spacings of these reflections were similar to the spacings of the high‐intensity reflections of the X‐ray diffraction pattern of the same mixture. This showed agreement between a bulk and a local technique, X‐ray and electron diffraction.
Microscopy of interfaces in model oxide composites
Authors: Johnson M. T. , Heffelfinger J. R. , Kotula P. G. , CARTER C. B. 
Published: November 2003

Solid‐state reactions are known to occur in composite materials during fabrication, processing or service. In the present study, a model approach for studying such reactions is illustrated. The goal of this approach is to understand the effects of, for example, temperature, time and other driving forces on the earliest stages of such reactions. Three different materials systems were used in order to investigate some of the fundamental processes occurring. Two of the systems involve spinel formation while the other is more complicated, since three different compounds can form between the end‐members. For all of these systems a thin‐film reaction geometry was utilized. High‐quality thin films of the various oxides were deposited on bulk substrates by pulsed‐laser deposition.NiO was deposited on four orientations of α‐Al2O3 in order to study the effect of crystal orientation (and therefore interfacial structure) on the growth kinetics of the nickel–aluminate spinel. The effect of an external electric field at elevated temperatures on the spinel‐forming reaction between Fe oxide and monocrystalline (001) MgO has been analysed. Thin films of Y2O3 were reacted with monocrystalline substrates of α‐Al2O3 at elevated temperatures to determine the reaction sequence: up to three different yttrium aluminates can form.
Development of an optimal protocol for the ultrastructural examination of skin by transmission electron microscopy
Authors: Van den Bergh B. A. I. , Swartzendruber D. C. , Bos‐van der Geest A. , Hoogstraate J. J. , Schrijvers A. H. G. J. , Boddé H. E. , Junginger H. E. , Bouwstra J. A. 
Published: November 2003

The intercellular lipid bilayers of the stratum corneum provide the permeability barrier of the skin. To perform an electron microscopical examination of the ultrastructure of these bilayers, ruthenium tetroxide fixation is required. In this study an optimal fixation protocol was developed and selected upon comparing seven different fixation procedures, using glutaraldehyde (GA) and the postfixatives ruthenium red, osmium tetroxide (OsO4) and ruthenium tetroxide (RuO4) in combination with potassium ferrocyanide (K4Fe(CN)6) and potassium ferricyanide (K3Fe(CN)6). Instead of fixing skin with either OsO4 or RuO4, these two fixatives were combined in one protocol. In addition, the use of RuRed was introduced and the influence of both K4Fe(CN)6 and K3Fe(CN)6 in combination with RuO4 were examined. Furthermore, we compared two dehydration solvents, methanol and acetone.The most satisfying results were obtained when the skin was prefixed in GA and postfixed in OsO4 and RuO4 with K3Fe(CN)6, i.e. with Fe in its highest oxidation state (Fe3+). No differences were observed between dehydration in methanol and acetone.
Improved preservation of the ram spermatozoan plasma membrane using betaine in the primary fixative
Authors: SWAN M. A. , ALBOGHOBEISH N. 
Published: November 2003

Improved preservation of ram spermatozoa was obtained by filtration onto a Millipore filter followed by fixation in a fixative containing 23 mm betaine, which raised fixative osmolality only slightly. In samples fixed in control preparations with betaine omitted the plasma membrane had a ruffled appearance, while the betaine‐containing fixative gave the plasma membrane a smooth contour which closely followed underlying structures.Betaine is known to function as an osmoprotectant in other situations, and may protect the cells from osmotic damage during the initial stages of fixation.
Growth Hormone (GH)‐Releasing Peptide and GH Releasing Hormone Stimulate GH Release from Subpopulations of Somatotrophs in Rats
Authors: Mitani Maki , Kaji Hidesuke , Abe Hiromi , Chihara Kazuo 
Published: November 2003

The synthetic hexapeptide GH‐releasing peptide (His‐D‐Trp‐Ala‐Trp‐D‐Phe‐Lys‐NH2; GHRP‐6) and GH releasing hormone (GHRH) are both potent stimulators of GH release in rats. Using reverse hemolytic plaque assay (RHPA), we have compared the effects of human GHRH and GHRP‐6 on GH release from the dispersed individual cells of rat anterior pituitary.In a single RHPA, we quantified the percentage of plaque forming cells (% PFC) and their mean plaque area (MPA) after 30 min‐incubation, and calculated a total secretion index (TSI) by multiplying % PFC and MPA. 10 nM GHRH and 100 nM GHRP‐6 each caused a significant increase in % PFC (%) (GHRH 39.15, GHRP‐6 29.4, vs vehicle 24.3, P<0.01), MPA (×10−2 μm2) (GHRH 124.04, GHRP‐6 94.80, vs vehicle 44.57, P<0.01) and TSI (×10−2) (GHRH 54.46, GHRP‐6 32.87, vs vehicle 10.84, P<0.01). Simultaneous addition of both secretagogues caused a further increase in GH release (%PFC 46.4, MPA 142.55, TSI 69.82, P<0.01 vs vehicle), although the effect was additive but not synergistic. Somatostatin analog, SMS201–995 (SMS) partially suppressed all parameters in GH secretion after stimulation by GHRH and/or GHRP‐6.A double RHPA was then performed to test whether all somatotrophs respond equally to GHRH and GHRP‐6 or some cells formed plaques only by either GHRH or GHRP‐6. There were somatotrophs responsive to only GHRH (23.3%vs control 6.2%, P<0.01), those responsive to only GHRP‐6 (11.9%vs control 6.1%, P<0.01), and those responsive to both GHRH and GHRP‐6 (7.8%vs control 0.2%, P<0.01).These results confirmed the previous findings that GHRP‐6 and GHRH directly but independently stimulate GH release from the pituitary cells, and further suggest the presence of at least three functionally distinct somatotroph subpopulations concerning the responsiveness to GHRP‐6 and GHRH in rats.
Production of an Oxytocin like Substance by the Subcommissural Organ (SCO), Related to the Reproductive Cycle in Oviparous and Viviparous Reptiles
Authors: D’Uva Ermelinda Limatola , Maria Gaia Monti  , Di Montefiano Rosita 
Published: November 2003

The subcommissural organ (SCO) is a circumventricular organ of glial origin typical of all vertebrates. The SCO releases its secretion into the third ventricle to constitute Reissner’s fibre (RF). Reportedly, in reptiles, SCO has cyclic secretory activity related to the reproductive cycle.In this immunocytochemical study we show that, in females of oviparous reptiles (Lacertidae: Podarcis sicula) and in a viviparous species (Scincidae: Chalcides chalcides), SCO secretion consists of hormones, in part of the oxytocin‐like (OXY‐like) type. The amount of OXY‐like material in the cells and in the third ventricle varies according to the different stages of the reproductive cycle. In the oviparous species, OXY‐like hormone secretion can be induced by FSH administration at 28 °C, in the period of winter reproductive stasis as well. In the viviparous skink, showing an annual single ovulatory cycle, OXY‐like secretion is present in the basal region of the cells, and is released into the third ventricle only at delivery. The role of an OXY‐like hormone in the SCO is here discussed in relation to the different stages of the reproductive cycle. Its influence on the hypothalamus‐hypophysis‐gonad axis and its role in the transport of eggs into the ducts in the oviparous species, and at delivery in the viviparous one, are also suggested.
Overexpression of nitric oxide synthases in tendon overuse
Authors: Szomor Z. L. , Appleyard R. C. , Murrell G. A. C. 
Published: November 2003

AbstractTendon disorders with a chronic nature, including the rotator cuff, are extremely common, and represent a major clinical problem. Mechanical overload has been proposed as an important etiologic factor in tendinopathies. Nitric oxide (NO), a free radical produced by nitric oxide synthases (NOSs), is a potent regulator and stimulator of biological processes including tendon degeneration and healing. It is also involved in response to mechanical stimuli in different tissues. In an animal model of acutely injured tendon healing temporal and differential expression of NOS isoforms has been demonstrated, suggesting that different patterns of NOSs expression may have different biological functions. Therefore, we hypothesized that tendon overuse may result in a differential upregulation of NOSs, particularly iNOS. An animal model of supraspinatus tendon overuse was utilized, which consisted of treadmill running. A group of animals of the same strain and age subjected to normal cage activity were used as controls. Following a 4‐week exercise protocol supraspinatus tendons were harvested, RNA was extracted, and subjected to competitive reverse transcription and polymerase chain reaction (RT‐PCR) to determine the expression levels of inducible‐, endothelial‐, and neuronal‐NOS isoforms (i‐, e‐, and nNOS). The mRNA expression of all three NOS isoforms increased in the supraspinatus tendons as a result of overuse exercise. iNOS and eNOS mRNA expression increased fourfold (p < 0.01), and there was an increase, but statistically not significant, in nNOS mRNA expression in the overused tendons when compared with the controls. This study is the first to show that NOS isoforms are upregulated in rotator cuff tendon as a result of chronic overuse, and suggests the involvement of nitric oxide in the response of tendon tissue to increased mechanical stress. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Collagen degradation products modulate matrix metalloproteinase expression in cultured articular chondrocytes
Authors: Fichter M. , Körner U. , Schömburg J. , Jennings L. , Cole A. A. , Mollenhauer J. 
Published: November 2003

AbstractDestruction of collagen within osteoarthritic cartilage depends in part on collagen‐degrading matrix metalloproteases (MMP). Degradative fragments of type II collagen (Col II) occur in normal and in osteoarthritic cartilage, and may contribute to regulation of matrix turnover by interfering with normal cell–matrix communication pathways. Therefore, the effects of different types of collagen fragments on mRNA and protein levels of MMP‐2, MMP‐3, MMP‐9, and MMP‐13 in cultured bovine articular knee chondrocytes and explants were examined. Primary chondrocytes and explants were incubated with fragments from whole cartilage collagen matrix (Colf) and from purified type II collagen (Col2f), or with a synthetic 29‐mer peptide representing the amino‐terminal domain of type II collagen (Ntelo). Gelatin zymography revealed increases of proMMP‐2, a shift towards active MMP‐2 and increases in proMMP‐9, depending on the type of fragment. In situ hybridization of cartilage sections displayed MMP‐3 mRNA in virtually all cells. Moderate to strong increases in MMP‐2, MMP‐3, MMP‐9, and MMP‐13 mRNA levels were detected by quantitative PCR. The results demonstrate stimulating effects of collagen fragments on both mRNA and/or protein from MMP ‐2, ‐3, ‐9, and ‐13, and suggest a novel mechanism of MMP induction and activation that includes a particular role for N‐telo in controlling catabolic pathways of matrix turnover. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Ecological interaction between sympatric Mytilus species on the west coast of Canada investigated using PCR markers
Authors: HEATH D. D. , HATCHER D. R. , HILBISH T. J. 
Published: November 2003

Abstract M. californianus is the dominant marine mussel species on exposed rocky shores, while M. trossulus is usually the dominant mussel species in more sheltered waters on the west coast of North America. Since these species are physically indistinguishable when small (< 10.0 mm), we developed two polymerase chain reaction (PCR) ‐based markers to discriminate between them. Using these markers, we identified mussels taken from an exposed coast (n= 114), a sheltered harbour (n= 80), and an upper‐intertidal pool (n= 42) on the west coast of Vancouver Island, British Columbia, Canada. M. californianus were found only on the open coast. Small M. trossulus (< 20.0 mm) were common to all three sample sites, but were extremely rare at larger sizes (> 20.0 mm) on the open coast. Our results indicate that M. californianus are excluded from sheltered waters via early life factors, while M. trossulus are excluded from the open coast due to mortality later in life.