bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is low birth weight a risk factor for the development of diabetic nephropathy in patients with type 1 diabetes? A population‐based case–control study
Authors: Eshoj O. , Vaag A. , Borch‐Johnsen K. , Feldt‐Rasmussen B. , Beck‐Nielsen H. 
Published: March 2003

Abstract.  Eshoj O, Vaag A, Borch‐Johnsen K, Feldt‐Rasmussen B, Beck‐Nielsen H (Odense University Hospital, Odense, Hvidovre Hospital, Copenhagen, Steno Diabetes Centre, Gentofte, University of Copenhagen, Copenhagen, Denmark). Is low birth weight a risk factor for the development of diabetic nephropathy in patients with type 1 diabetes? A population‐based case–control study. J Intern Med 2002; 252: 524–528.Objectives.  To investigate if low birth weight as a consequence of intrauterine malnutrition is a risk factor for the later development of diabetic nephropathy.Design and subjects.  In a case–control set‐up a group of type 1 diabetic subjects with diabetic nephropathy (n = 51) and a matched control group with normal kidney function (n = 51) were compared. Diabetic nephropathy and normal kidney function were defined as urinary albumin excretion rate above 200 μg min−1 and below 20 μg min−1, respectively. The birth weights were all obtained from the midwives' original records.Setting.  The patients were identified from a population‐based study of chronic diabetic complications in the Funen County, Denmark.Main outcomes.  Birth weights according to the presence of diabetic nephropathy.Results.  The median (10–90 percentile) birth weights were 3600 g (2960–4274) in the group with diabetic nephropathy and 3600 g (2880–4220) in the group without nephropathy, P = 0.52. In the lower quartile of birth weights the median (10–90 percentile) birth weights were 3000 g (2780–3200) in the group with nephropathy versus 2850 g (2250–3175) in the group without nephropathy, P = 0.07. In the upper quartile the median (10–90 percentile) birth weights were 4225 g (4000–4741) in the nephropathy group and 4000 g in the group without nephropathy, P = 0.13. We found no significant correlation between birth weights and log urinary albumin excretion rate (r = 0.148, P = 0.14) and no difference in the number of patients with nephropathy in the lower versus upper quartiles of birth weights.Conclusion.  We found no evidence of low birth weight as a risk factor for the development of diabetic nephropathy.
Inflammatory bowel disease: new insights into pathogenesis and treatment
Authors: Ardizzone S. , Porro G. Bianchi 
Published: March 2003

Abstract. Ardizzone S, Bianchi Porro G (‘L. Sacco’ University Hospital, Milan, Italy). Inflammatory bowel disease: new insights into pathogenesis and treatment (Review).J Intern Med2002;252:475–496.Despite all the advances in our understanding of the pathophysiology of inflammatory bowel disease (IBD), we do not know the cause. Some of the most recently available data have been discussed here and yet it is now becoming increasingly accepted that immunogenetics play an important role in the predisposition, modulation, and perpetuation of IBD. The mucosal immune system is the central effector of intestinal inflammation and injury, with cytokines playing a central role in modulating inflammation. The role of intestinal milium, and enteric flora in particular, appears to be of greater significance than previously held. A review is made of the main areas of research exploring the mechanisms more intimately associated with the development of IBD, providing advances in the agents currently used, and identifying a host of new therapeutic agents potentially interacting with or interrupting specific targets in the genesis of IBD.
Risk factors for coronary heart disease in 55‐ and 35‐year‐old men and women in Sweden and Estonia
Authors: Johansson J. , Viigimaa M. , Jensen‐Urstad M. , Krakau I. , Hansson L.‐O. 
Published: March 2003

Abstract.  Johansson J, Viigimaa M, Jensen‐Urstad M, Krakau I I, Hansson L‐O (Karolinska Hospital, Stockholm, Sweden, Tartu University Hospital, Tartu, Estonia). Risk factors for coronary heart disease in 55‐ and 35‐year‐old men and women in Sweden and Estonia. J Intern Med 2002; 252:551–560.Objective.  To illustrate the geographical West‐to‐East division of coronary heart disease (CHD) by comparing a population from Sweden, that represents a Western country to a population from Estonia, that represents an Eastern country. Estonia has an approximately 2–4‐fold higher CHD prevalence for 55‐year‐old women and men, respectively, than Sweden.Design.  Randomized screening of 35‐ and 55‐year‐old men and women in Sollentuna county, Sweden and Tartu county, Estonia. Eight hundred subjects, 100 from each cohort, were invited to participate in the study, 272 Swedes and 277 Estonians participated.Setting.  Preventive cardiology, administered by a primary health care centre at the Karolinska Hospital, Sweden and a cardiology centre at Tartu University Hospital, Estonia.Main outcome measures.  The CHD risk factors (smoking, blood pressure, concentrations of lipoproteins, fibrinogen, and glucose) and certain environmental factors and attitudes related to CHD risk by questionnaires (fat‐type and alcohol ingestion, self‐assessed rating of CHD susceptibility).Results.  Of the 55‐year‐old men, 57% smoked in Estonia and 20% smoked in Sweden. Similar, although less pronounced differences showing higher smoking prevalence, were seen for 35‐year‐old Estonian men and women, whilst for 55‐year‐old women, less than 20% smoked in either country. Estonian 55‐year‐old women had lower HDL cholesterol and higher LDL cholesterol serum concentrations than Swedish 55‐year‐old women. Estonians reportedly ate food containing more saturated fats than Swedes, as indicated by the scale‐score questionnaire. Estonians, relative to Swedes, rated their chance of developing CHD higher, and paradoxically, Estonians did to a much lesser degree believe that life style influences the risk of developing CHD.Conclusions.  Elevated smoking prevalence is a striking difference between the Estonian and Swedish populations likely to explain the much higher CHD prevalence in Estonian men. The lower HDL cholesterol and higher LDL cholesterol in Estonian 55‐year‐old women may explain the higher CHD prevalence in Estonian women. Furthermore, the SWESTONIA CHD study (i.e. comparison between Sweden and Estonia) shows several environmental differences between the countries populations related to fat content in food, alcohol drinking patterns, and views on CHD risk and the importance of lifestyle intervention, that could contribute to the higher CHD prevalence in Estonia.
On the analysis of spatial binary images
Authors: Lang C. , Ohser J. , Hilfer R. 
Published: March 2003

This paper deals with the analysis of spatial images taken from microscopically heterogeneous but macroscopically homogeneous microstructures. A new method is presented, which is strictly based on integral‐geometric formulae such as Crofton's intersection formulae and Hadwiger's recursive definition of the Euler number. By means of this approach the quermassdensities can be expressed as the inner products of two vectors where the first vector carries the ‘integrated local knowledge’ about the microstructure and the second vector depends on the lateral resolution of the image as well as the quadrature rules used in the discretization of the integral‐geometric formulae. As an example of application we consider the analysis of spatial microtomographic images obtained from natural sandstones.
Direct observation of a Ti/Cu interface with atomic displacement under electron irradiation
Authors: Ohta S. , Sakaguchi N. , Shibayama T. , Takahashi H. 
Published: March 2003

A Ti film was deposited onto a Cu substrate by means of a radio frequency magnetron sputtering method. Cross‐sectional thin foils for TEM observation were prepared using a focused ion beam. Electron irradiation was carried out using a high‐resolution high‐voltage electron microscope operated at 1.25 MV. The Cu/Ti interface of the foils was irradiated at 623 K. In‐situ observation images during electron irradiation were recorded by a CCD camera with a digital video cassette. The (020)Cu plane on the Cu/Ti interface preferentially moved towards the Ti film with irradiation. Composition analysis of the diffused region showed that its composition corresponded to Ti3Cu2.
A dual path programmable array microscope (PAM): simultaneous acquisition of conjugate and non‐conjugate images
Authors: Heintzmann R. , Hanley Q. S. , Arndt‐Jovin D. , Jovin T. M. 
Published: March 2003

A programmable array microscope (PAM) incorporates a spatial light modulator (SLM) placed in the primary image plane of a widefield microscope, where it is used to define patterns of illumination and/or detection. We describe the characteristics of a special type of PAM collecting two images simultaneously. The conjugate image (Ic) is formed by light originating from the object plane and returning along the optical path of the illumination light. The non‐conjugate image (Inc) receives light from only those regions of the SLM that are not used for illuminating the sample. The dual‐signal PAM provides much more time‐efficient excitation than the confocal laser scanning microscope (CLSM) and greater utilization of the available emission light. It has superior noise characteristics in comparison to single‐sided instruments. The axial responses of the system under a variety of conditions were measured and the behaviour of the novel Inc image characterized. As in systems in which only Ic images are collected (Nipkow‐disc microscopes, and previously characterized PAMs), the axial response to thin fluorescent films showed a sharpening of the axial response as the unit cell of the repetitive patterns decreased in size.The dual‐signal PAM can be adapted to a wide range of data analysis and collection strategies. We investigated systematically the effects of patterns and unit cell dimensions on the axial response. Sufficiently sparse patterns lead to an Ic image formed by the superposition of the many parallel beams, each of which is equivalent to the single scanning spot of a CLSM. The sectioning capabilities of the system, as given by its axial responses, were similar for a given scan pattern and for processed pseudorandom sequence (PRS) scans with the same size of the unit cell. For the PRS scans, optical sectioning was achieved by a subtraction of an Inc image or, alternatively, a scaled widefield image from the Ic image. Based on the comparative noise levels of the two methods, the non‐conjugate subtraction was significantly superior. A point spread function for Ic and Inc was simulated and properties of the optical transfer functions (OTFs) were compared. Simulations of the OTF in non‐conjugate imaging did not suffer from the missing cone problem, enabling a high quality deconvolution of the non‐conjugate side alone. We also investigated the properties of images obtained by subjecting the Ic and Inc data to a combined maximum likelihood deconvolution.
Crystallographic orientation of ZrB2‐ZrC composites manufactured by the spark plasma sintering method
Authors: Shim S. H. , Niihara K. , Auh K. H. , Shim K. B. 
Published: March 2003

SummaryThe crystallographic grain orientation of ZrB2‐ZrC composites manufactured using a spark plasma sintering (SPS) method, a new sintering technique in development for poorly sinterable ceramic materials, was analysed by the scanning electron microscopy‐electron backscattered diffraction (SEM‐EBSD) method. Their crystallographic features have been compared with those of a conventionally sintered specimen using a pressureless sintering (PLS) method. In the composite sintered by PLS, (0001) planes of ZrB2 were orientated in the direction parallel to the specimen surface (RD) but (1010) and (2110) planes randomly orientated. In the case of SPS, (0001) planes of ZrB2 were orientated normal to the specimen surface (ND) and weakly to the RD. In both cases of PLS and SPS, ZrC grains had a randomly orientated grain structure. The distribution of grain boundary misorientation of PLS and SPS‐processed composites showed the same tendency that high‐angle boundaries were more prevalent than low‐angle boundaries. But in the case of ZrC grains in the SPS sample, the proportion of CSL boundaries with low sigma value (3, 5, 7, 9, 11) was relatively larger.
Is fast mapping good mapping? A review of the benefits of high‐speed orientation mapping using electron backscatter diffraction
Authors: Trimby P. , Day A. , Mehnert K. , Schmidt N.‐H. 
Published: March 2003

SummaryOrientation mapping using automated electron backscatter diffraction (EBSD) is now a common technique for characterizing microstructures. Improvements in software and hardware have resulted in high‐speed mapping capabilities above 80 000 points h−1. For ‘routine’ microstructural analyses of materials such as steel and aluminium (e.g. texture and grain size measurements and high angle boundary characterization), high‐speed orientation mapping is an ideal approach with minimal penalty on the final statistics. However, for the accurate analysis of very low angle boundaries and for routine analyses of more difficult materials (e.g. most rock samples), we advocate a more patient approach to orientation mapping with an emphasis on data accuracy and reliability. It is important that the objectives of any EBSD analysis are carefully considered before starting – in this way the maximum potential of an EBSD system can be achieved.
Minimizing scanning electron microscope artefacts by filter design
Authors: Aronsson M. , Savborg Ö. , Borgefors G. 
Published: March 2003

SummaryA new type of non‐linear filter for digital images has been developed. By using distance transforms we estimate the average point spread function for a set of fibre cross‐sectional images. Then a fast filter technique, based on lookup tables for distance layers, attenuates the uneven background response from the scanning electron microscope. Compared to the convolution‐based techniques that we tried, this approach caused less blurring effects on our fibre images and also made the background pixels more homogeneous. The only assumption we make is that we can roughly segment the background pixels by using a pixel‐wise classifier.Although the assumption that the uneven background response can be described by a circular point spread function is only approximately true in the case discussed here, this method greatly attenuates the effect and provides a fast and general filtering method that can also be of use for other applications.
Rapid cryofixation of rabbit muscle fibres after a temperature jump
Authors: Bennett P. M. , Tsaturyan A. , Bershitsky S. 
Published: March 2003

SummaryWe describe a procedure whereby structural changes that occur in muscle fibres after a rapid temperature jump can be captured by cryofixation. In the thick filament from rabbit and other mammalian skeletal muscles there is a rapid transition from a non‐helical to a helical structure as the temperature is raised from 273 K towards physiological levels. This transition is accompanied by characteristic intensity changes in the X‐ray diffraction pattern of the muscle. In our experiments to capture these changes, single fibres of glycerinated psoas muscle were subjected to a Joule temperature jump of 15–30 K from ~278 K in air. We have developed a freezing method using a modified Gatan cryosnapper in which a pair of liquid nitrogen‐cooled copper jaws were projected under pressure and closed on the fibre between 50 and 100 ms after the temperature jump. The frozen fibres were freeze‐substituted and embedded for electron microscopy. Transverse and longitudinal sections of relaxed ‘cold’ (~278 K) and temperature‐jumped fibres as well as rigor fibres were obtained. Fourier transforms of the images from the three preparations showed differences in the relative intensities of the reflections from the hexagonal filament lattice and in those of the helix‐based layer lines, similar to the differences seen by X‐ray diffraction. We conclude that we have preserved the ‘hot’ structure and that cryofixation is sufficiently fast to prevent the transition back to the ‘cold’ state.
Embedding in Spurr's resin is a good choice for immunolabelling after freeze drying as shown with chemically unfixed dendritic cells
Authors: Spehner D. , Drillien R. , Proamer F. , Hanau D. , Edelmann L. 
Published: March 2003

SummaryImmunocytochemical reactions on biological specimens depend on many factors, the most crucial one being the maintenance of antigenicity. Antigens are vulnerable at each stage during preparation for electron microscopy. One of the least traumatic methods of preparing biological tissues for post‐embedding immunolabelling includes the following steps: (1) physical stabilization of the native biological material by rapid freezing (cryofixation) and keeping the immobilized biological sample at low temperature, thereby avoiding any movements of water, ions and macromolecules; (2) dehydrating the frozen biological material by freeze‐drying at low temperature; (3) embedding of the dehydrated specimen. Here we show that embedding of chemically unfixed dendritic cells in Spurr's resin after cryofixation and freeze‐drying enables the conservation of fine ultrastructure without cell distortion or shrinkage. Furthermore, we demonstrate the feasibility of protein localization in ultrathin sections by immunolabelling of the major histocompatibility class II molecules.
Neural Circuits Regulating Pulsatile Luteinizing Hormone Release in the Female Guinea‐Pig: Opioid, Adrenergic and Serotonergic Interactions
Authors: Gore A. C. , Terasawa E. 
Published: March 2003

AbstractWe studied three neurotransmitters involved in the regulation of pulsatile luteinizing hormone (LH) release: opioid peptides, serotonin and norepinephrine, using the ovariectomized guinea‐pig. This is an attractive animal model due to the regularity of its LH pulses, enabling any disruptions to be clearly ascertained. In all experiments, a specific agonist or antagonist was administered, either alone or serially to enable detection of interactions, and effects on mean LH concentrations, pulse amplitude and interpulse interval were determined by PULSAR analysis. In the ovariectomized guinea‐pig, catecholamines are stimulatory (acting through the α1 and α2 but not β receptors, unlike other species), opioids inhibitory and serotonin permissively stimulatory to pulsatile LH release. Stimulatory effects of the opiate antagonist were not blocked by pretreatment with an α1‐ or α2‐adrenergic antagonist. Similarly, pretreatment with the opiate antagonist did not prevent the suppression of LH release by α1 and α2 antagonists. This suggests that, in the guinea‐pig, effects of opiates and catecholamines on LH release are exerted by independent pathways to luteinizing hormone releasing hormone (LHRH) neurones. For the opiate–serotonin interactions, pretreatment with the serotonergic antagonist did not block the stimulatory effect of the opiate antagonist on LH release. However, pretreatment with the opiate agonist could not be overcome by the serotonergic agonist. This suggests that the effects of the serotonin system on LHRH release may be indirectly mediated by opioid neurones. Taken together, these studies demonstrate that the three neurotransmitter systems studied are critically involved in normal pulsatile LH release in the female guinea‐pig, and demonstrate novel functional relationships between the opioid and the adrenergic and serotonergic systems.
Increased Synaptic Input to Gonadotropin Releasing Hormone Cells in Preoptic Area Grafts That Support Reproductive Development in Female Hypogonadal Mice
Authors: Rajendren G. , Gibson M. J. 
Published: March 2003

AbstractUltrastructural studies have established that gonadotropin releasing hormone (GnRH) neuronal cell bodies receive sparse synaptic input compared to other neuronal cell types. In the present studies, immunocytochemistry for the presynaptic marker synaptophysin, coupled with confocal microscopy, was employed to evaluate whether there was a difference in synaptic input to GnRH cells within preoptic area grafts (hypogonadal, HPG; preoptic area, POA) in hypogonadal female mice that did or did not show ovarian development. GnRH cells in HPG/POA mice with ovarian development exhibited significantly higher numbers of synaptophysin immunoreactive (syn‐IR) appositions as compared with HPG/POA mice without ovarian development. This suggests that synaptic input to the grafted GnRH cells is important for the correction of reproductive functions in HPG/POA mice. Following mating, Fos immunoreactivity was present in several GnRH cells in HPG mice with successful POA grafts, indicating the establishment of neuronal projections conveying somatosensory information to the GnRH cells in these mice. The presence of a higher number of syn‐IR appositions to GnRH cells in the successful grafts supports this hypothesis.
Rapid Upregulation of Aromatase mRNA and Protein Following Neural Injury in the Zebra Finch (Taeniopygia guttata)
Authors: Peterson R. Scott , Saldanha C. J. , Schlinger B. A. 
Published: March 2003

AbstractThe expression of aromatase (oestrogen synthase) within the vertebrate central nervous system (CNS) is key in the provision of local oestrogens to neural circuits. Aromatase expression appears to be exclusively neuronal under normal conditions. However, some in vitro studies suggest the presence of astrocytic aromatase in songbirds and mammals. Recently, aromatase in reactive astrocytes has been demonstrated in response to neural injury in the mammalian CNS. Since the glial aromatase expression first documented in cultures of the songbird telencephalon may reflect processes similar to those in response to mammalian neural injury, we investigated whether injury alters the pattern of aromatase‐expression in the zebra finch, a species with very high levels of forebrain aromatase expression. Adult males received a penetrating neural injury to the right hemisphere and were killed either 24 or 72 h later. Controls were anaesthetized and otherwise unmanipulated. We determined the expression of aromatase mRNA and protein using in situ hybridization and immunocytochemistry, respectively. Both the transcription and translation of aromatase is dramatically upregulated around the lesion site in response to neural injury in the zebra finch forebrain. This effect is robust and rapid, occurring within 24 h of the injury itself. Cells that upregulate aromatase appear to be reactive astrocytes based upon morphology. The hemisphere contralateral to the injury and both hemispheres in control birds showed the normal, exclusively neuronal pattern of aromatase expression. The upregulation of aromatase in astrocytes may provide high levels of oestrogen available to modulate processes such as CNS repair. Injury‐induced upregulation of astrocytic aromatase may be a general characteristic of the injured vertebrate brain.