bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperinsulinaemia as long‐term predictor of death and ischaemic heart disease in nondiabetic men: The Malmö Preventive Project
Authors: Nilsson P. , Nilsson J‐Å. , Hedblad B. , Eriksson K‐F. , Berglund G. 
Published: March 2003

Abstract. Nilsson P, Nilsson J‐Å, Hedblad B, Eriksson K‐F, Berglund G. (University Hospital, Malmö, Sweden) Hyperinsulinaemia as long‐term predictor of death and ischaemic heart disease in nondiabetic men: The Malmö Preventive Project.J Intern Med2003;253:136–145.Objectives. Prospective studies have indicated that hyperinsulinaemia/insulin resistance is a risk factor for ischaemic heart disease (IHD), the risk decreasing with time of follow‐up. Few studies have so far investigated the role of hyperinsulinaemia in the prediction of long‐term total mortality.Setting. Section of Preventive Medicine, Department of Medicine, University Hospital, Malmö, Sweden.Subjects. A total of 6074 nondiabetic, middle‐aged, healthy Swedish males.Screening examination. We determined IHD risk factors including blood glucose and plasma insulin before and 2 h after an oral glucose tolerance test (OGTT). Total follow‐up time was 19 years. Hyperinsulinaemia was defined as values above the 10th decentile of fasting or 2 h insulin concentration.Main outcome measures. Total mortality and cardiac event (CE) rate for IHD.Results. Unadjusted relative risks (RRs) for both death and CE were J‐shaped with the highest relative risk (RR: 1.4–1.6) in the hyperinsulinaemic group compared with all other men. The RRs for death and CE were significant for fasting insulin but became nonsignificant after adjustment for other risk factors and also with a longer follow‐up. The risk of death in hyperinsulinaemic men, defined on the basis of 2‐h insulin level, increased with time of follow‐up and was still significantly increased after 19 years [RR: 1.32 (95% CI: 1.05–1.65], even after adjustment for other risk factors.Conclusions. Fasting hyperinsulinaemia was a predictor of total mortality and IHD in nondiabetic men, although not more significantly after adjustment for other risk factors and with lengthening of follow‐up time. The 2‐h postglucose hyperinsulinaemia appeared to be a stronger and independent predictor of mortality over long‐term follow‐up. These findings support the view that insulin resistance with associated cluster of risk factors predicts increased long‐term risk of mortality and IHD.
No acute impact of haemodialysis treatment on free radical scavenging enzyme gene expression in white blood cells
Authors: Schettler V. , Kühn W. , Kleinoeder T. , Armstrong V. W. , Oellerich M. , Müller G. A. , Wieland E. 
Published: March 2003

Abstract.  Schettler V, Kühn W, Kleinoeder T, Armstrong VW, Oellerich M, Müller GA, Wieland E (Georg‐August‐University, Göttingen, Germany). No acute impact of haemodialysis treatment on free radical scavenging enzyme gene expression in white blood cells. J Intern Med 2003; 253: 201–207.Objective.  Oxidative stress has been implicated in the side‐effects caused by haemodialysis (HD) treatment.Design.  In the present study we have investigated whether gene expression of the enzymatic defence system provided by cellular glutathione peroxidase (GPx‐1), phospholipid glutathione peroxidase (GPx‐4), glutathione reductase (GSSG‐R), glutathione synthethase (GSH‐S), Cu/Zn‐superoxide dismutase (SOD‐1) and catalase (CAT) is affected by HD.The GPx‐1, GPx‐4, GSSG‐R, GSH‐S, SOD‐1 and CAT mRNA were determined in white blood cells by quantitative reverse transcriptase‐polymerase chain reaction with the LightCycler® instrument and transcription elongation factor‐2 as reference gene at the start (SD) and immediately after (ED) dialysis treatment (n = 36). In a subgroup (n = 10), messenger RNA (mRNA) expression was determined hourly during a 5 h HD.Results.  The expression of GPx‐1, GPx‐4, GSSG‐R, GSH‐S, SOD‐1 and CAT mRNA was not affected by a single HD treatment. All mRNAs were significantly (P < 0.05) increased in HD patients [median (16. percentiles (perc.); 84. perc.)]: GPx‐1: 2.18 (0.89; 3.23); GPx‐4: 0.41 (0.26; 0.74); GSSG‐R: 0.04 (0.02; 0.10); GSH‐S: 0.04 (0.02; 0.08); SOD‐1: 0.32 (0.20; 0.62); CAT: 0.12 (0.06; 0.18) when compared with healthy blood donors (GPx‐1: 0.91 (0.60; 1.44); GPx‐4: 0.27 (0.16; 0.43); GSSG‐R: 0.02 (0.01; 0.02); GSH‐S: 0.02 (0.02; 0.04); SOD‐1: 0.15 (0.10; 0.18); CAT: 0.07 (0.04; 0.16).Conclusions.  These results show that the HD procedure does not acutely affect the antioxidant defence system on the gene level but suggest that the chronic stress caused by uraemia and/or HD may cause gene induction of the enzymatic defence system.
Crystallographic analysis of facets using electron backscatter diffraction
Authors: RANDLE V. 
Published: March 2003

Applications of electron backscatter diffraction (EBSD), also known as backscatter Kikuchi diffraction in the scanning electron microscope (SEM) are first and foremost microtexture and grain boundary misorientation analysis on a single polished section in the specimen. A more subtle and revealing approach to analysis of these data is to use EBSD to probe the orientations of planar surfaces, i.e. facets, which bound crystals. These surfaces include: • grain or phase boundaries • fractures • cracks It is of great interest to know the crystallography of such facets since it provides a key to understanding the physical properties of them.As far as investigation methodology is concerned, surfaces or facets associated with polycrystals are of two types: exposed or unexposed. Exposed facets, such as a fracture surface, can be viewed directly in the SEM, whereas unexposed facets, such as a grain boundary, are usually revealed as an etched trace on a polished surface. Photogrammetric methods can be used to obtain the positional orientation of an exposed facet, and the crystallographic orientation is obtained either directly from the surface or by indirect sectioning. Calibrated sectioning is required to obtain the equivalent parameters for an internal surface. The present paper compares the methods for obtaining and interpreting the crystallography of facets, with illustrations from several materials.
Methodological principles for fractal analysis of trabecular bone
Authors: Parkinson  , Fazzalari  
Published: March 2003

A standardized methodology for the fractal analysis of histological sections of trabecular bone has been established.A modified box counting method has been developed for use on a PC‐based image analyser. The effect of image analyser settings, magnification, image orientation and threshold levels was determined. Also, the range of scale over which trabecular bone is effectively fractal was determined and a method formulated to calculate objectively more than one fractal dimension from the modified Richardson plot.The results show that magnification, image orientation and threshold settings have little effect on the estimate of fractal dimension. Trabecular bone has a lower limit below which it is not fractal (λ < 25 μm) and the upper limit is 4250 μm. There are three distinct fractal dimensions for trabecular bone (sectional fractals), with magnitudes greater than 1.0 and less than 2.0.It has been shown that trabecular bone is effectively fractal over a defined range of scale. Also, within this range, there is more than one fractal dimension, describing spatial structural entities. Fractal analysis is a model‐independent method for describing a complex multifaceted structure, which can be adapted for the study of other biological systems. This may be at the cell, tissue or organ level and complements conventional histomorphometric and stereological techniques.
Image analysis of insulation mineral fibres
Authors: Talbot H. , Lee T. , Jeulin D. , Hanton D. , Hobbs L. W. 
Published: March 2003

We present two methods for measuring the diameter and length of man‐made vitreous fibres based on the automated image analysis of scanning electron microscopy images. The fibres we want to measure are used in materials such as glass wool, which in turn are used for thermal and acoustic insulation. The measurement of the diameters and lengths of these fibres is used by the glass wool industry for quality control purposes. To obtain reliable quality estimators, the measurement of several hundred images is necessary.These measurements are usually obtained manually by operators. Manual measurements, although reliable when performed by skilled operators, are slow due to the need for the operators to rest often to retain their ability to spot faint fibres on noisy backgrounds. Moreover, the task of measuring thousands of fibres every day, even with the help of semi‐automated image analysis systems, is dull and repetitive. The need for an automated procedure which could replace manual measurements is quite real.For each of the two methods that we propose to accomplish this task, we present the sample preparation, the microscope setting and the image analysis algorithms used for the segmentation of the fibres and for their measurement. We also show how a statistical analysis of the results can alleviate most measurement biases, and how we can estimate the true distribution of fibre lengths by diameter class by measuring only the lengths of the fibres visible in the field of view.
GELFISH – Graphical environment for labelling fluorescencein‐situhybridization images
Authors: Lerner B. , Dhanjal S. , Hultén M. A. 
Published: March 2003

Signal (dot) counting in fluorescencein‐situhybridization (FISH) images that relies on an automatic focusing method for obtaining clearly defined images is a time‐consuming procedure prone to errors. Our recently developed system has dispensed with automatic focusing, and instead relies on a neural network classifying focused and unfocused signals into valid and artefact data, respectively, and thereby discriminating between in‐ and out‐of‐focus images. However, to train the classifier accurate labelling of the image signals is required. GELFISH is a Graphical Environment for Labelling FISH images that enables the rejection of unanalysable nuclei and labelling of FISH signals simply and rapidly. GELFISH is flexible and can be modified easily for additional FISH applications. Also, implemented using popular software, the environment can be employed on any computer by any user. Finally, GELFISH is proposed in controlling a classifier‐based dot counting system.
Multi‐field 3D scanning light microscopy of early embryogenesis
Authors: Czirók A. , Rupp P. A. , Rongish B. J. , Little C. D. 
Published: March 2003

SummaryA computer‐controlled microscopy system was devised to allow the observation of avian embryo development over an extended time period. Parallel experiments, as well as extended specimen volumes, can be recorded at cellular resolution using a three‐dimensional scanning procedure. The resulting large set of data is processed automatically into registered, focal‐ and positional‐drift corrected mosaic images, assembled as montages of adjacent microscopic fields. The configuration of the incubator and a sterile embryo chamber prevents condensation of the humidified culturing atmosphere in the optical path and is compatible with both differential interference contrast and epifluorescence optics. As a demonstration, recordings are presented showing the large‐scale remodelling of the embryonic primordial vascular structure.
Energy dispersive spectroscopy analysis of aluminium segregation in silicon carbide grain boundaries
Authors: Zhang X. F. , Yang Q. , De Jonghe L. C. , Zhang Z. 
Published: March 2003

SummaryThe aluminium distribution in polycrystalline SiC hot‐pressed with aluminium, boron and carbon additives was studied using X‐ray energy‐dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The Al excess in homophase SiC grain boundary films was determined, taking into account dissolved Al in the SiC lattice. In the spot‐EDS analysis, an electron beam probe with a calibrated diameter was formed, and the total beam–specimen interaction volume was defined, taking the beam spreading through crystalline TEM foil into consideration. EDS spectra were collected from regions containing intergranular films and adjacent matrix grains, respectively. A theoretical treatment was presented and experimental errors were estimated, with a further discussion about the effects of foil thickness. Experimental examples are given, followed by statistical EDS analyses for grain boundary films in SiC samples hot‐pressed with increased amounts of Al additions. The results demonstrated a substantial Al segregation in the nanometer‐wide intergranular films in all samples. Al additions higher than 3 wt% saturated the Al concentrations in SiC grains and in grain boundary films. The effect of foil thickness, and the parameters for determining the optimum incident beam diameter in the EDS analysis are discussed.
Characterization of the cutting edge of glass and diamond knives for ultramicrotomy by scanning force microscopy using cantilevers with a defined tip geometry. Part II
Authors: Matzelle T. R. , Gnaegi H. , Ricker A. , Reichelt R. 
Published: March 2003

SummaryThe cutting edge of glass as well as diamond knives was studied at high resolution using a scanning force microscope (SFM). The local shape of the cutting edge was estimated from single line profiles of the SFM topographs taking into account the exact shape of the probing tip estimated by a high‐resolution field emission scanning electron microscope (FESEM). The glass knives were prepared by ‘balanced breaking’. The radius of the investigated cutting edges was found to be 3.2–4.4 nm and 4.3–6.0 nm for the 35° and 45° diamond knife, respectively, and 3.4–4.3 nm for the glass knives.Besides the opening angle and the cutting edge radius, the friction of a knife during sectioning represents a significant factor influencing the quality of sections. Thus, the roughness of both the diamond clearance angle side and the back side was characterized as well. Corresponding RMS values of the roughness were found to be smaller on the back side (≈ 0.14 nm) than on the clearance angle side (≈ 0.26 nm).
Suppression of Adrenocorticotropic Hormone Release by Stimulation of the Nerve Fibres in the Anterior Pituitary
Authors: Gao L.‐Z. , Zhang W.‐H. , Ju G. 
Published: March 2003

AbstractWith the recent revelation of considerable peptidergic innervation of the anterior pituitary in several mammalian species, including man, it becomes imperative to elucidate the physiological significance of such a morphological entity. We addressed this issue by employing an anterior pituitary slice in vitro superfusion system coupled with electrical field stimulation. Anterior pituitary slices of 0.8 mm were perfused with Krebs‐Ringer bicarbonate–bovine serum albumin buffer in a superfusion chamber for 30 min before electrical field stimulation. A square current of 30 mA, 10 Hz and 0.5 ms was then applied for 10 min. The perfusate was collected every 10 min and measured for adrenocorticotropic hormone (ACTH) by radio‐immunoassay. It was found that under the experimental condition the basal release of ACTH was suppressed by electrical field stimulation of the nerve fibres in the anterior pituitary. Furthermore, vasopressin was added as a secretagogue. The suppression of ACTH by electrical field stimulation became even more marked. This is the first physiological evidence of the effect of stimulation of the nerve fibres innervating the anterior pituitary on its secretory activity.
Blunted Pituitary‐Adrenocortical Stress Response in Adult Rats Following Neonatal Dexamethasone Treatment
Authors: Felszeghy K. , Bagdy G. , Nyakas C. 
Published: March 2003

AbstractGlucocorticoids have a prominent impact on the maturation of the stress‐related neuroendocrine system and on the postnatal establishment of adaptive behaviour. The present study aimed at investigating the stress responsiveness of the hypothalamo‐pituitary‐adrenocortical (HPA) axis in young and adult rats after neonatal treatment with the synthetic glucocorticoid agonist, dexamethasone. Newborn male Wistar rats were injected s.c. with 1 µg/g dexamethasone on postnatal days 1, 3 and 5. Circulating adrenocorticotropic hormone (ACTH) and corticosterone concentrations were measured in the resting state and following a 30‐min cold stress at the age of 10 days, as well as after a 30‐min restraint stress at the age of 14 weeks. Also in adults, pituitary and adrenocortical hormone responsiveness was evaluated after i.v. administration of 2 µg/kg corticotropin releasing hormone (CRH). In addition, glucocorticoid (GR) and mineralocorticoid receptor (MR) binding capacities were assessed in the pituitaries of adult rats. The results showed that at day 10 basal ACTH concentration was elevated while the cold stress‐evoked ACTH response was attenuated in the dexamethasone‐treated rats. As adults, treated rats showed a suppressed elevation of both ACTH and corticosterone plasma cncentrations in response to restraint, while basal hormonal concentrations were not altered. There was no difference in the magnitude of the CRH‐induced elevation of ACTH and corticosterone concentrations initially; however, the dexamethasone‐treated animals showed a prolonged secretion of both hormones. These animals also showed a selective decrease in pituitary GR binding capacity. Neonatal dexamethasone treatment strongly suppressed body weight gain, and adrenal and thymus weights in the early phase of postnatal development. By adulthood, the body and adrenal weights were normalized while thymus weight was greater than in controls. These findings indicate that neonatal dexamethasone treatment permanently alters HPA axis activity by reducing stress responses to cold and restraint probably through supra‐pituitary actions, and by decreasing the effectiveness of feedback through a diminished GR binding in the pituitary.
Selective Corticotropin‐Releasing Factor Type 1 Receptor Antagonist Blocks Conditioned Fear‐Induced Release of Noradrenaline in the Hypothalamic Paraventricular Nucleus of Rats
Authors: Otagiri A. , Wakabayashi I. , Shibasaki T. 
Published: March 2003

AbstractThe effects of conditioned fear on the release of noradrenaline in the hypothalamic paraventricular nucleus (PVN) and the involvement of corticotropin‐releasing factor (CRF) receptor type 1 (CRFR1) in conditioned fear‐induced changes in noradrenaline release were examined by intracerebral microdialysis in rats. Conditioned fear was produced by placing animals into a box where they had previously been exposed to a 5‐min period of electric footshock, 135 min prior to the start of experiment. Conditioned fear for 20 min produced a significant increase in the release of noradrenaline in the PVN. Intraperitoneal preadministration of a selective nonpeptidic CRFR1 antagonist, CRA1000, completely blocked the conditioned fear‐induced release of noradrenaline. These results suggest that CRFR1 is involved in the release of noradrenaline in the hypothalamic PVN induced by conditioned fear.
Systemic Administration of Ghrelin Induces Fos and Egr‐1 Proteins in the Hypothalamic Arcuate Nucleus of Fasted and Fed Rats
Authors: Hewson A. K. , Dickson S. L. 
Published: March 2003

AbstractGhrelin, a recently identified endogenous ligand for the growth hormone secretagogue (GHS) receptor, induces growth hormone (GH) secretion following systemic administration. We sought to determine whether systemic administration of ghrelin activates cells in the hypothalamic arcuate nucleus by examining the distribution of cells expressing Fos and Egr‐1 proteins. In normally fed rats, both ghrelin and GHRP‐6 (a synthetic GHS) significantly increased the number of cells expressing Fos and Egr‐1 in the arcuate nucleus. The effects of ghrelin and GHRP‐6 to induce Fos or Egr‐1 protein expression was significantly greater in fasted than in fed rats. Thus, we show that (i) ghrelin is a centrally active peptide; (ii) it acts in a similar manner to synthetic GHS; and (iii) its central actions are increased in fasting, presumably reflecting physiological changes that accompany altered food intake and/or nutritional state.
Differential Neuropeptide Responses to Starvation with Ageing
Authors: Kaneda T. , Makino S. , Nishiyama M. , Asaba K. , Hashimoto K. 
Published: March 2003

AbstractDuring starvation, counterregulatory responses to loss of food (i.e. responses that lead to an increase in appetite) occur in the central nervous system (CNS). This study was designed to examine whether middle‐aged rats show greater or smaller behavioural, peripheral and central hormonal responses during starvation compared to young rats. In experiment 1, refeeding following 4 days of starvation was measured in both middle‐aged (72‐week‐old) and young (9‐week‐old) rats. The level of refeeding was similar to each prestarved level until 3 days after the end of starvation in both groups. From the 4th day, the level of refeeding in young rats increased and reached beyond the prestarved level, whereas refeeding in middle‐aged rats remained similar to the prestarved level. Thus, overall refeeding throughout 7 days was greater in young rats than in middle‐aged rats. In experiment 2, middle‐aged and young rats were starved for 4 days and were killed in the morning. Middle‐aged rats showed a smaller plasma corticosterone response than that of young rats. The magnitude of decreases in plasma glucose, insulin and leptin was similar in both groups. In the arcuate nucleus, the starvation‐induced increase in neuropeptide Y (NPY) mRNA and the decrease in proopiomelanocortin (POMC) mRNA were smaller in middle‐aged rats than in young rats. In contrast, the starvation‐induced decrease in corticotrophin‐releasing hormone (CRH) mRNA in the hypothalamic paraventricular nucleus was greater in middle‐aged rats than young rats. The magnitude of decrease in type‐2 CRH receptor mRNA in the ventromedial hypothalamus was similar in both groups. The results indicate that (a) ageing impaired refeeding response (b), middle‐aged rats showed the same directional neuropeptide mRNA responses as seen in young rats during starvation and (c) the magnitude of these counterregulatory responses in the CNS in middle‐aged versus young rats was not uniform, but rather was site‐specific or neuropeptide‐specific. This study suggests the importance of NPY and POMC responsiveness in the arcuate nucleus in the age‐related differences resulting from starvation‐induced refeeding.
Effects of Vasoactive Intestinal Polypeptide on Neurones of the Rat Suprachiasmatic Nuclei In Vitro
Authors: Reed H. E. , Cutler D. J. , Brown T. M. , Brown J. , Coen C. W. , Piggins H. D. 
Published: March 2003

AbstractThe suprachiasmatic nuclei (SCN) of the hypothalamus house the main circadian pacemaker in mammals. Vasoactive intestinal polypeptide (VIP) is the most abundant neuropeptide in the SCN and has been shown to phase‐shift the electrical activity rhythm of SCN cells in vitro. However, the effects of VIP on the cellular activity of rat SCN neurones are unknown. In this study, we examined the acute effects of VIP on the extracellularly recorded spontaneous firing rate of SCN neurones in an in‐vitro hypothalamic slice preparation. Furthermore, with the use of receptor‐selective agonists and antagonists, we determined which receptors might mediate the effects of VIP in the SCN. Approximately 50% of cells responded to VIP; the main type of response was suppression in firing rate, although a few cells were activated. Suppression responses to VIP were mimicked by the VPAC2 receptor agonist Ro 25‐1553 and blocked by the selective VPAC2 receptor antagonist PG 99‐465. The PAC1 receptor agonist maxadilan evoked responses from 40% of SCN cells, and activations to this agonist were not altered by PG 99‐465. Responses to VIP were not blocked by antagonists to ionotropic glutamate receptors, but the duration of suppression was modulated by the GABAA receptor antagonist bicuculline. Our data indicate that VIP alters the electrical activity of rat SCN neurones in vitro, via both VPAC2 and PAC1 receptors.