bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological analysis of gastro‐esophageal diseases by molecular cell techniques
Authors: Jankowski Janusz , Henders Karen , Viaene Anne , Baert Johann , Long Lu Qi 
Published: February 2005

AbstractThe molecular cell sciences have had a great impact in the analysis of the genetic and epigenetic events of esophageal and gastric tumorigenesis. In other regions of the alimentary tract such as the colon, the serial identification of the molecular events in the corresponding morphological lesions is perhaps most advanced. This is, in part, due to the relative ease of the histological characterisation of the premalignant lesions. In this regard the analysis of morphological and molecular adaptation in the alimentary tract is inextricable. This review aims, therefore, to judiciously assess the relative applications of contemporary techniques in investigative histopathology. © 1995 Wiley‐Liss, Inc.
Scanning electron microscopy of the human esophagus: Application to barrett's esophagus, a precancerous lesion
Authors: Shields H. M. , Sawhney R. A. , Zwas F. , Boch J. A. , Kim S. , Goran D. , Antonioli D. A. 
Published: February 2005

AbstractIn Barrett's esophagus, metaplastic columnar epithelium replaces the normal squamous epithelium. The importance of this lesion lies in the increased incidence of adenocarcinoma of the esophagus occuring in patients with Barrett's esophagus. We characterized the surface epithelial cells of Barrett's esophagus using quantitative scanning electron microscopy. Three distinct surface cell types, in addition to the goblet cell, were recognized in Barrett's epithelium: the gastric‐like cell and the intestinal‐like cell, both of which were similar to normal gastric and small intestinal surface cells, respectively, by quantitative scanning electron microscopy, and the variant cell which had a range of surface features. In four biopsy specimens from the squamo‐Barrett's junction in three patients, we found the distinctive cell that had features intermediate between those of squamous and columnar epithelium. On the distinctive cell's surface there are two disparate structures not normally present on the same cell in the gastrointestinal tract: microvilli (a scanning electron microscopy feature of glandular epithelium) and intercellular ridges (a scanning electron microscopy feature of squamous epithelium). The surface characteristics of this cell were almost identical to those of cells found in the transformation zone of the uterine cervix, an area in which squamous epithelium physiologically replaces columnar epithelium. Scanning electron microscopy of Barrett's esophagus has increased our understanding of this precancerous lesion by showing striking cellular heterogeneity. It has also identified the distinctive cell which may represent an intermediate step in the development of Barrett's epithelium during which the surface characteristics of two different cell types, columnar and squamous, coexist in the same cell. © 1995 Wiley‐Liss, Inc.
Quantitation of fibroblast population growth rate in situ using computerized image analysis
Authors: Perricone Michael A. , Saldate Veronica , Hyde Dallas M. 
Published: February 2005

AbstractThe development of computer‐assisted image analysis has provided the technology to rapidly determine the population size of cultured cell monolayers in situ. We have adapted this technology to determine the population growth rate of cultured fibroblasts for use in a highreplicate format. Human lung fibroblasts were seeded into 1/2 A 96‐well plates that had one‐half the culture area of standard 96‐well plates. The cells were cultured in medium supplemented with different concentrations of FBS and on days 0, 1, 2, 3, 5, and 7, and their nuclei were stained with propidium iodide. A microscopic field representing one‐quarter of a well of fluorescent nuclear images was captured onto a Macintosh computer, and the number of nuclei were counted using an image analysis software program. There were no significant differences between the number of nuclei counted manually and the number counted using computer‐assisted software, until day 7 where the cells were multilayered (P < 0.05). This image analysis method was compared to other assays typically used to estimate cell proliferation or population size, namely hemocytometer counting, a rapid colorimetric staining assay using naphthol blue‐black, and [3H]‐thymidine incorporation. The growth rates derived using image analysis were in close agreement with results derived from hemocytometer counts and [3H]‐thymidine incorporation. However, the growth rates of cells grown in high concentrations of FBS as determined using naphthol blue‐black were substantially lower than results from image analysis. We conclude that this adaptation of computer‐assisted image analysis provides a method to derive accurate growth curves by directly counting the number of cells in a large number of replicates. © 1995 Wiley‐Liss, Inc.
On the use of local statistical properties in focusing microscopy images
Authors: Lipton Alan , Breen Edmond J. 
Published: February 2005

AbstractTechniques to extract focus properties of microscopy images are many and varied. Many of them, however, rely on the summation of local statistical properties. Presented here is an examination of conventional focus determination algorithms, and a new method based on planar histograms of these local statistical properties. It is shown that this new method provides finer discernment of the focus properties of an image, and provides a means to extend the focus of an optical microscopy system. © 1995 Wiley‐Liss, Inc.
Myocardial gap junction organization in ischemia and infarction
Authors: Peters Nicholas S. 
Published: February 2005

AbstractIschemia causes an increase in myocardial resistivity and a decrease in conduction velocity, thereby enhancing cardiac contractile dysfunction and arrhythmic tendency. Myocardial gap junctions, as principal determinants of conduction velocity, may, therefore, be expected to be deranged in ischemia. Despite a lack of consensus, attempts at correlating gap junction ultrastructural morphology with functional state have revealed the component connexons of gap junctions in freeze‐fractured myocardium to be in multiple small hexagonal arrays, tending to become randomly distributed and compacted under uncoupling conditions. Further hypoxic uncoupling causes ultrastructural damage and a reduction in gap‐junctional surface area. Immunohistochemical detection of connexin43 gap junctions in chronically ischemic non‐infarcted human myocardium demonstrates a reduction in junctional surface area within a normal number of intercalated disks per myocyte, and with a normal distribution of junction sizes. In healed canine infarction there are smaller and fewer gap junctions in the fibrotic myocardium adjacent to infarcts, with reductions in overall gap‐junctional content and the proportion of side‐to‐side vs. end‐to‐end intercellular connections. Immunohistochemical examination of intact human ventricular myocardium shows the myocytes immediately abutting healed infarcts to hve connexin43 gap junctions spread longitudinally over the cell surfaces, and not in discrete transversely orienated intercalated disks as in normal myocardium. Early after canine infarction, and before fibrotic healing, the connexin43 gap junctions in myocytes abutting the infarct show disorganization similar to that described in healed human infarcts, suggesting that this disturbance is an early pathophysiological cellular response, and not simply due to later fibrotic distortion. Such changes in gap‐junctional organization in myocardial ischemia and infarction may be implicated in the elusive link between subcellular structure, contractile dysfunction and arrhythmogenesis. © 1995 Wiley‐Liss, Inc.
Ultrastructure and histochemistry of acid mucus glycoproteins in the estrous mammal oviduct
Authors: Jansen Robert P. S. 
Published: February 2005

AbstractThe mucous surfaces of the oviducts of mammals, especially humans, are dependant on estradiol. The mucus glycoproteins and glycocalyceal glycoproteins have, however, barely been studied. Biochemical analyses have focussed on the relatively low molecular weight glycoproteins likely to be found in more serous‐type granules of the ampulla and not on the very high MW glycoproteins typical of mucus and represented in the isthmus by morphological evidence of mucus secretion. Quantitatively, secretion from the ampulla is likely to predominate, because of its huge surface area compared with the isthmus. But functional closure of the isthmus under the influence of estradiol in the absence of progesterone means that it is the isthmus where luminal secretions accumulate—and where mucus glycoproteins will exert their most important effects on spermatozoa ascending the reproductive tract, and then on fertilized ova en route to the uterus. Further study of the extracellular, intraluminal, carbohydrate‐rich environment of the oviductal isthmus, especially in humans, is likely to prove rewarding. Sampling of these secretions is now feasible using transvaginal, transuterine fallopian tube catheters that are in clinical use. © 1995 Wiley‐Liss, Inc.
Myelin mutants: New models and new observations
Authors: Lunn Katharine F. , Fanarraga Monica L. , Duncan Ian D. 
Published: February 2005

AbstractThe myelin mutants have been extensively used as tools to study the complex process of myelination in the central and peripheral nervous system. A multidisciplinary approach to the study of these models ultimately allows a correlation to be made between phenotype and genotype. This correlation may then lead to the formation of new hypotheses about the functions of the products of genes involved in myelination. This review presents a number of new myelin mutants which have recently been described. The species involved include mouse, rat, rabbit, hamster, and dog models. The genetic defect has not been elucidated in all of these animals, but most have been characterized clinically and pathologically, and, in some cases, biochemically. In addition, a better known myelin mutant, the trembler mouse, is discussed. Recent molecular findings have brought this fascinating mutant to the forefront of the field of peripheral nervous system research. The range of abnormalities in the mutants described in this review includes defects in specific myelin proteins, suspected abnormalities in membrane formation, and apparent defects of the oligodendrocyte cytoskeleton. These findings underscore the complexity of the myelination process and highlight the numerous ways in which it can be disrupted. © 1995 Wiley‐Liss, Inc.
Two models of multiple sclerosis: Experimental allergic encephalomyelitis (EAE) and theiler's murine encephalomyelitis virus (TMEV) infection. A pathological and immunological comparison
Authors: Dal Canto Mauro C. , Melvold Roger W. , Kim Byung S. , Miller Stephen D. 
Published: February 2005

AbstractTheiler's murine encephalomyelitis virus (TMEV) infection and experimental allergic encephalomyelitis (EAE) are considered among the best models of human multiple sclerosis (MS). In both models, clinical disease is characterized by paralysis, while pathological changes consist of inflammatory demyelination. In both models there is a genetic influence on susceptibility/resistance to the development of disease. This has been thoroughly studied in TMEV infection, and it has been found to depend on both major histocompatibility complex (MHC) and non‐MHC genes. At least four genes have been so far identified. Because of this genetic influence, some strains of mice are more susceptible to both clinical and pathological changes than others, and susceptibility appears to best correlate with the ability of a certain murine strain to develop a delayed‐type hypersensitivity (DTH) response to viral antigens. We have also observed that even among mice which are equally susceptible clinically, striking differences may be seen under pathological examination. These consist of different gradients of severity of inflammation, particularly in regards to the macrophage component. There is an inverse relationship between the number of macrophages, and their length of stay in the CNS, and the ability of mice to remyelinate their lesions. The most severe lesions are in SJL/J mice, and remyelination in this strain is extremely poor. The least severe lesions in terms of macrophage invasion are in strains such as NZW and RIIIS/J, and these are able to remyelinate lesions very successfully. Murine chronic relapsing EAE (CR‐EAE) shows pathological changes in many ways similar to those in TMEV‐infected SJL/J mice, although less severe in terms of degrees of macrophage infiltration and tissue destruction. Mice with CR‐EAE have a correspondingly limited ability to remyelinate their lesions. In both models the pathology appears to be mediated through a DTH response. However, while in EAE the DTH response is clearly against neuroantigens, the response in TMEV infection is against the virus itself. The end result in both models would be that of myelin destruction through a lymphotoxincytokine‐mediated mechanism. The importance of the DTH response in both models is well illustrated by the effects of tolerance induction in EAE and TMEV infection to neuroantigens and virus, respectively. These are important models of human MS, since the current hypothesis is that a viral infection early in life, on the appropriate genetic background, may trigger a secondary misdirected immune response which could be directed either against myelin antigens and/or possible persistent virus(es). © 1995 Wiley‐Liss, Inc.
Effects of extracellular matrix on differentiation of mouse fetal gonads in the absence of mesonephros in vitro
Authors: Kanai Yoshiakira , Kanai‐Azuma Masami , Kurohmaru Masamichi , Yazaki Kazumori , Hayashi Yoshihiro 
Published: February 2005

AbstractThe influence of mesonephric tissues and the extracellular matrix on mouse gonadal differentiation was examined in vitro. Gonadal ridges, with or without the adjacent mesonephric region, were removed from mouse embryos on day 12 post coitum (p.c.), and cultured in the presence or absence of reconstituted basement membrane (matrigel) for 5 days. Culturing control undifferentiated testes with mesonephric tissues induced normal testicular differentiation. When testes without mesonephric tissues were cultured in the absence of matrigel, testicular cord formation was not observed in the explants. Sertoli cells were irregularly arranged in the testicular parenchyma, and no continuous basal lamina was formed around the Sertoli cells. However, when testes without mesonephric tissues were embedded in matrigel and cultured for 5 days, the Sertoli cells were organized into testicular cord‐like structures. The Sertoli cells positioned at the base of the cord‐like structures were closely connected to the matrigel at their basal surface, and showed a polarized distribution of vimentin filaments in their basal cytoplasm. Leydig cells, on the other hand, were differentiated in all testicular explants. In all ovarian explants, germ cells normally entered meiotic prophase. Therefore, these findings indicate that the extracellular matrix permits testicular differentiation in the absence of the mesonephros, and that removal of mesonephric tissues leads to developmental failure of cord formation because the components of the extracellular matrix around pre‐Sertoli cells are incomplete. © 1995 Wiley‐Liss, Inc.
A transmission electron microscope (TEM) calibration standard sample for all magnification, camera constant, and image/diffraction pattern rotation calibrations
Authors: McCaffrey J. P. , Baribeau J.‐M. 
Published: February 2005

AbstractA calibration sample for transmission electron microscopy (TEM) has been developed that performs the three major instrument calibrations for a transmission electron microscope: the image magnification calibration for measurements of images, the camera constant calibration for indexing diffraction patterns, and the image/diffraction pattern rotation calibration for relating crystal directions to features in the image. This offers an improvement over commercially available calibration standards, where up to five different samples are required to perform these three calibrations. The new calibration sample consists of an electron‐transparent cross‐sectional TEM sample made from a molecular beam epitaxy (MBE)‐grown, single‐crystal semiconductor wafer. When the calibration structure is viewed in a TEM, it appears as a series of light and dark layers where the layer thicknesses are very accurately known. The calibrated thickness measurements of these light (silicon) and dark (SiGe alloy) layers are based on careful TEM measurements of the {111} lattice spacing of silicon which is visible on the calibration sample itself, and are supported by X‐ray diffraction measurements. Furthermore, the layer thickness variation across the entire silicon wafer has been verified to be less than 1%, allowing all samples prepared from the same wafer to have errors in the given layer thickness values of less than 1%. As the sample is a single crystal of silicon, the calibrations requiring electron diffraction information such as the camera constant calibration and the image/diffraction pattern rotation calibration can also be performed easily and unambiguously. One single calibration sample can therefore be used to provide all three of the major TEM instrument calibrations at all magnifications and all camera lengths. © 1995 Government of Canada.Exclusive worldwide publication rights in the article have been transferred to Wiley‐Liss, Inc., in perpetuity.
A specimen holder for high‐resolution low‐temperature scanning electron microscopy
Authors: Bastacky Jacob , Lee Charles , Freeman Tony , Weber George , Baeza Armando , Hubbins Ted , Chen Ya 
Published: February 2005

AbstractA miniature vise built into a 5 mm diameter copper capsule is described that holds small pieces of prefrozen, hydrated specimens at low temperatures within the lens of the Hitachi S900 high‐resolution scanning electron microscope.
Distribution and possible role of perinuclear theca proteins during bovine spermiogenesis
Authors: Oko R. , Maravei D. 
Published: February 2005

AbstractThe perinuclear theca (PT) is a unique cytoskeletal element that encapsulates the mammalian sperm nucleus. It is divided into subacrosomal and postacrosomal regions. The objective of this study was to analyze and stage the intracellular distribution of several promiment bull PT proteins during spermatogenesis. For this purpose, polyclonal antibodies raised and affinitypurified against the 15.5‐, 25‐, 28‐, 32‐, 36‐, and 60‐kDa bull PT polypeptides were used as probes on sections of aldehyde‐fixed testes. Immunoperoxidase staining revealed that the PT polypeptides first appeared early in spermiogenesis, concomitant with early steps of development of the acrosomic system. Immunogold labeling further showed that these polypeptides were peripherally associated with the entire acrosomal membrane, before and during the attachment of the acrosomic vesicle onto the spermatid's nucleus. Once the acrosome had capped the nucleus the labeling resided mainly in the subacrosomal region of the spermatid, between the inner acrosomal membrane and nuclear envelope. Later, during the elongation of the spermatid's nucleus, the labeling with all antibodies except the anti‐15.5‐kDa antibody extended caudally over the assembling postacrosomal sheath. This study suggests that the perinuclear theca proteins play an instrumental role in the attachment, spreading, and binding of the acrosome onto the nucleus of spermatids. © 1995 Wiley‐Liss, Inc.
The acyclic edge chromatic number of a random d‐regular graph is d + 1
Authors: Nešetřil Jaroslav , Wormald Nicholas C. 
Published: February 2005

AbstractWe prove the theorem from the title: the acyclic edge chromatic number of a random d‐regular graph is asymptotically almost surely equal to d + 1. This improves a result of Alon, Sudakov, and Zaks and presents further support for a conjecture that Δ(G) + 2 is the bound for the acyclic edge chromatic number of any graph G. It also represents an analog of a result of Robinson and the second author on edge chromatic number. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 69–74, 2005
Improved Anti‐Inflammatory and Pharmacokinetic Properties for Superoxide Dismutase by Chemical Glycosidation with Carboxymethylchitin
Authors: Valdivia Aimara , Perez Yunel , Dominguez Amalia , Caballero Julio , Gomez Leissy , Schacht Etienne H. , Villalonga Reynaldo 
Published: February 2005

AbstractSummary: O‐Carboxymethylchitin (molecular weight = 1.07 × 105, degree of carboxymethylation = 80%, degree of N‐acetylation = 91%) was chemically attached to superoxide dismutase by the formation of amide linkages through a carbodiimide catalyzed reaction. The glycosidated enzyme contained about 1.8 mole of polysaccharide per mole of protein and retained 57% of the initial catalytic activity. The anti‐inflammatory activity of the enzyme was 2.4 times increased after conjugation with the polysaccharide. The modified superoxide dismutase preparation was remarkably more resistant to inactivation with H2O2 and its plasma half‐life time was prolonged from 4.8 min to 69 h.Superoxide dismutase‐O‐carboxymethylchitin conjugate.magnified imageSuperoxide dismutase‐O‐carboxymethylchitin conjugate.
Alkaline and Enzymatic Degradation of L‐Lactide Copolymers, 1
Authors: Tsuji Hideto , Tezuka Yasufumi 
Published: February 2005

AbstractSummary: Films of poly(L‐lactide) [i.e., poly(L‐lactic acid) (PLLA)] and L‐lactide copolymers with glycolide [P(LLA‐GA)(81/19)], ε‐caprolactone [P(LLA‐CL)(82/18)], D‐lactide [P(LLA‐DLA)(95/5), (77/23), and (50/50)] were prepared and a comparative study on the effects of comonomer type and content on alkaline and proteinase K‐catalyzed hydrolyses of the films was carried out. The hydrolyzed films were investigated using gravimetry (weight loss and water absorption), differential scanning calorimetry (DSC), polarimetry, and gel permeation chromatography (GPC). To exclude the effects of molecular weight and crystallinity on the hydrolysis, the films were prepared from polymers having similar molecular weights and made amorphous by melt‐quenching. It was found that incorporation of hydrophilic glycolide units in L‐lactide chains raises the alkaline and enzymatic hydrolyzabilities, whereas incorporation of hydrophobic ε‐caprolactone units in L‐lactide chains reduces the alkaline and enzymatic hydrolyzabilities. On the other hand, incorporation of D‐lactide units with the same hydrophilicity of L‐lactide units increases the alkaline hydrolyzability but decreases the enzymatic hydrolyzability. The alkaline hydrolyzability of the films of L‐lactide copolymers with different kinds of comonomers and P(LLA‐DLA) with different D‐lactide unit contents can be closely related to their hydrophilicity. On the other hand, the enzymatic hydrolyzability of L‐lactide copolymer films with different kinds of comonomers is mainly determined by hydrophilicity, while that of P(LLA‐DLA) films is determined by the averaged L‐lactyl and D‐lactyl unit sequence lengths. The catalytic effect of proteinase K relative to that of alkali on the hydrolysis of P(LLA‐DLA)(77/23) and P(LLA‐GA)(81/19) films normalized by that of PLLA was lower than unity, whereas the normalized relative catalytic effect of proteinase K on the hydrolysis of P(LLA‐CL)(82/18) film was higher than unity, meaning that despite low absolute alkaline and enzymatic hydrolyzability of the P(LLA‐CL)(82/18) film, the catalytic effect of proteinase K may be maintained for this copolymer film, probably because of its blocky structure.
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