bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exemptions to School Immunization Requirements: The Role of School-Level Requirements, Policies, and Procedures
Authors: Salmon Daniel A. , Omer Saad B. , Moulton Lawrence H. , Stokley Shannon , deHart M. Patricia , Lett Susan , Norman Bryan , Teret Stephen , Halsey Neal A. 
Published: February 2005

Objectives. Our goal was to determine whether school-level variability in implementation of immunization requirements is associated with the likelihood of a child having received an exemption to school immunization requirements. Methods. We surveyed 1000 school immunization personnel in Colorado, Massachusetts, Missouri, and Washington. We explored associations between school implementation of immunization requirements and the likelihood of a child having an exemption using logistic regression models. Results. School policies associated with an increased likelihood of children having exemptions included lack of provision of written instructions for completing the school immunization requirement before enrollment, administrative procedures making it easier to claim an exemption, and granting of philosophical exemptions. In the 2 states we surveyed where philosophical exemptions are not authorized (Massachusetts and Missouri), 17.0% and 18.1% of schools reported permitting philosophical exemptions. Conclusions. Inconsistencies in the interpretation and implementation of school immunization laws contribute to variability in rates of exemptions. School policies should be reviewed to ensure consistency with the intent of state laws.
Fall-Induced Deaths Among Elderly People
Authors: Kannus Pekka , Parkkari Jari , Niemi Seppo , Palvanen Mika 
Published: February 2005

Falls and fall-induced injuries in older people are a major public health problem in modern societies with aging populations. Injury is the fifth leading cause of death in older adults, and most of these fatal injuries are related to falls. We have assessed the nationwide trends in fall-induced deaths of older people in Finland for more than 3 decades (1971–2002), and the results showed that the number of fall-induced deaths among elderly Finns is clearly increasing, especially among men.
Helper‐Dependent Adenoviral Vectors
Authors: Oka Kazuhiro , Chan Lawrence 
Published: February 2005

AbstractThe helper‐dependent adenovirus (HDAd) is a recently developed adenovirus‐based vector with an improved safety profile and long‐term transgene expression. In this unit, a basic procedure for HDAd production using the Cre‐loxP system is presented. Amplification and large‐scale production of the vector can be done in both adherent and suspension cell culture systems. Included are protocols for Southern blot analysis to monitor vector amplification, slot blot assay to determine the infectious titer of the purified HDAd, and real‐time PCR to detect helper virus contamination in the preparation.
Basics of Digital Microscopy
Authors: Bernas Tytus 
Published: February 2005

AbstractDigital microscopy combines the equipment of classic light microscopy with a computerized imaging system, i.e., a digital camera. This technique comprises image formation by optics, image registration by a camera, and saving of image data in a computer file. This chapter describes limitations that are particular to each of these processes, including optical resolution, efficiency of image registration, and characteristics of image file formats. Knowledge with regard to these limitations serves, in turn, to help construct a set of guidelines aimed at optimization of digital microscopic imaging.
Time‐Lapse Microscopy Approaches to Track Cell Cycle Progression at the Single‐Cell Level
Authors: Errington Rachel J. , Marquez Nuria , Chappell Sally C. , Wiltshire Marie , Smith Paul J. 
Published: February 2005

AbstractTime‐lapse microscopy can be described as the repeated collection of a field of view from a microscope at discrete time intervals. The duration of the time interval defines the temporal resolution, which in turn characterizes the type of event detected. This unit describes the implementation of time‐lapse microscopy to link initial cell cycle position during acute exposures to anti‐cancer agents with anti‐proliferative consequences for individual cells. The approach incorporates fundamental concepts arising from the ability to capture simple video sequences of cells from which it is possible to extract kinetic descriptors that reflect the interplay of mitosis and cell death in the growth of an unsynchronized tumor population. Utilizing a multi‐well format enables the user to test different drug derivatives, multiple dose ranges, or cell cultures with unique genetic backgrounds. The objective of this unit is to present a generic methodology for capturing time‐lapse sequences and subsequently mining the data for comprehensive event analysis.
A comparative study of the fine structure of the trophoblast in several hemochorial placentas
Authors: Enders Allen C. 
Published: February 2005

AbstractPortions of the labyrinth or villi of placentas from late pregnancy from nine species in four orders of mammals were examined with the electron microscope. Pronounced patterns of layering of the trophoblast were found in these placentas which were all of the hemochorial type. The laboratory rat, laboratory mouse, hamster, and deer mouse have three layers of trophoblast between the maternal blood space and fetal vessels (hemotrichorial), the rabbit two layers (hemodichorial), the guinea pig and chipmunk one layer (labyrinthine hemomonochorial), and the human and armadillo one layer (villous hemomonochorial).The outer layer of trophoblast of the hemotrichorial placentas (the layer next to the maternal blood) is cellular, but the next two layers are apparently syncytial and are closely apposed to one another. The outer layer of the rabbit placenta is syncytial, while the inner layer contains some pockets of cells. In all of the hemomonochorial placentas examined, the continuous layer of trophoblast was syncytial. It was found that the surface layer of trophoblast of all the placentas studied is rich in granular endoplasmic reticulum, whereas in subsequent layers this element is less abundant. All of the placentas show both surface and basal modifications of trophoblast, but caveolae (pinocytotic vesicles) were found to be most commonly located in crypts, pockets, or other regions somewhat removed from the surface. It is suggested that an area of relative stasis of maternal plasma may be important for absorption of some substances by the placenta.
Osmium impregnation of the Golgi apparatus
Authors: Friend Daniel S. , Murray Michael J. 
Published: February 2005

AbstractThe Golgi complex consists of a heterogeneous assemblage of small vesicles, larger vacuoles and characteristic packets of flattened cisternae morphologically distinct from other membranous organelles of the cytoplasm. It is polarized with respect to its position in the cell and also shows recognizable polarity in the arrangement of structural components within the complex. This polarity holds for cells in which the Golgi complex seems to have quite different functions, such as in the epithelial cells of mouse epididymis and of Brunner's gland, and plasma cells in the lamina propria of the intestine examined in this study. The present investigation employs a classical method for impregnation of the Golgi apparatus with the objective of more accurately localizing with the electron microscope the sites of osmium reduction within this heterogeneous organelle and of comparing the distribution of these sites with morphological indications of polarization within the Golgi lamellar systems. The osmium impregnation procedure generally used in this study consisted of fixing the tissues in 1.3% osmium tetroxide buffered with s‐collidine followed by osmication in 2% aqueous osmium tetroxide for 40 hours at 40°C. After osmication the three cell types studied consistently exhibited a selective localization of osmium in the cisternae and vesicles on one side of the Golgi complex. The observations that only the outer vesicles and cisternae contain osmium while other cytologically similar elements under the same conditions do not, emphasizes the heterogeneous, bipolar nature of the Golgi apparatus. The substances responsible for osmium reduction are quite dependent on the local environment provided are apparently formed during the prolonged phase of the exposure of the tissue to osmium and are most likely localized at the inner face of the membrane of the outer cisternae and vesicles.
On the cytology and cytochemistry of the opossum's bronchial glands
Authors: Sorokin Sergei Pitirimovitch 
Published: February 2005

AbstractThe numerous compound acinar, mixed, bronchial glands of the opossum's lungs collectively provide a large surface for secretion. The secretory materials are made by two types of cells located in the acini and smaller ducts. Mucus is produced by mucous cells that are similar to those found elsewhere. A fluid of unknown composition appears to be secreted by hydrotic cells. The acini are encircled by myoepithelium and the larger ducts are lined by morphologically unspecialized cells. The hydrotic cell, a type of “special serous cell,” is cytologically the most interesting of the elements present. It is not appreciably basophilic and lacks secretion granules, but it is rich in glycogen and contains many mitochondria with high succinoxidase activity. The basal surface is divided into irregular compartments by grooves, some of which are occupied by processes from stellate myoepithelial cells. The apical surface is villous and extends far down the sides of the cell as intercellular canaliculi. This surface has adenosine triphosphatase activity and is contacted by the agranular reticulum and numerous small vesicles in the subjacent cytoplasm. The bronchial glands are classified in the discussion, and special features of the hydrotic cells are compared with those possessed by other types of cells that engage in ion‐segregation or ion‐secretion. The glands are thought to assist in temperature regulation.
Morphologic heterogeneity of mouse Paneth cell granules before and after secretory stimulation
Authors: Staley Mary W. , Trier Jerry S. 
Published: February 2005

AbstractPaneth cells from fasted, fed and pilocarpine stimulated mice were studied with the light and electron microscopes. While human and rat Paneth cells contain structurally homogeneous granules, most mouse Paneth cell granules were found to be structurally heterogeneous both by light and electron microscopy. These structurally heterogeneous granules consisted of an outer rim or halo which surrounded the central core of the granule. These halos varied strikingly in electron density ranging from much paler to much darker than the granule core. Electron density of the halos correlated well with their affinity for toluidine blue in light microscopic preparations. The granule halo could be stained with both alcian blue and with PAS indicating that it contained acid mucopolysaccharide while the central core of the granule could be stained only with PAS and not with alcian blue.While actively secreting Paneth cells were seen in preparations from fasting mice, the secretory activity was increased after feeding and after stimulation with pilocarpine. The actively secreting mouse Paneth cells discharged their granules into the crypt lumen by merocrine secretion. The fine structure of mouse Paneth cell granules was the same in resting and in actively secreting cells.
Vestibular projections to the nuclei of the extraocular muscles Degeneration resulting from discrete partial lesions of the vestibular nuclei in the monkey
Authors: McMasters Robert E. , Weiss Arthur H. , Carpenter Malcolm B. 
Published: February 2005

AbstractIn 35 monkeys attempts were made to produce localized unilateral lesions in individual vestibular nuclei in order to study vestibular projections to nuclei of the extraocular muscles. Portions of the medial, superior and inferior vestibular nuclei were destroyed selectively; lesions in Deiters' nucleus involved small portions of either the superior or inferior vestibular nuclei. Fiber degeneration was studied by the Nauta‐Gygax technic.Exclusively ascending fibers from the superior vestibular nucleus project to ipsilateral extraocular nuclei. Ascending fibers from the inferior vestibular arise only from rostral portions of the nucleus, are not numerous and pass to all extraocular nuclei. The medial vestibular nucleus projects ascending fibers via the MLF bilaterally, asymmetrically and differentially to all extraocular nuclei. Prominent projections pass to: (a) the contralateral trochlear nucleus, and (b) the contralateral intermediate cell column and the ipsilateral ventral nucleus of the oculomotor complex. Ascending fibers from Deiters' nucleus, arising only from ventral portions of the nucleus, project primarily to: (a) the contralateral abducens and trochlear nuclei, and (b) specific asymmetrical portions of the oculomotor complex.Ascending vestibular fibers from the medial and lateral vestibular nuclei appear capable of mediating all patterned eye movements resulting from stimulation of ampullary nerves from individual semicircular canals. Vestibular projections to nuclei of the extraocular muscles are most abundant to those nuclei innervating muscles whose primary functions concern horizontal and rotatory eye movements.
Histogenesis of choroid plexus in man
Authors: Shuangshoti Samruay , Netsky Martin G. 
Published: February 2005

AbstractFour stages of development can be recognized in the histogenesis of the human telencephalic choroid plexus. Division into stages is based on alterations of outline of the plexus, characteristic appearance and biochemical content of the epithelial cells, and the components of the stroma. The stages are less distinctive in the myelencephalic and diencephalic plexus where differentiation is accomplished sooner than in the telencephalic plexus. Neuroepithelial‐lined tubules are common in the choroid plexus, and are formed by folding of choroidal epithelium into the stroma. Some tubules are large enough to be designated as incipient neuroepithelial (colloid) cysts. Cysts having only connective tissue walls are also present. The choroidal epithelial cells proliferate focally, stratify and desquamate into intervillous clefts, or flow into the stroma by disruption of the epithelial basement membrane or tubular wall. These findings are confirmed by use of serial sections. The size of the developing telencephalic plexus relative to the ventricular system is small at first, then large, occupying almost the entire telencephalon, but gradually decreases during development. Glycogen is prominent in developing choroidal epithelial cells, but disappears in the mature plexus. Both epithelial and mesenchymal mucin and muco‐polysaccharides are identified in the plexus. The paraphysis is re‐emphasized as an extraventricular choroid plexus on the basis of a common neuroepithelial origin. It is rudimentary and inconstant in man.
On anatomy of nerves by galen of pergamon
Authors: Goss Charles Mayo 
Published: February 2005

AbstractIn this treatise Galen gives a synopsis of the description of the nerves contained in his long anatomical work “On Anatomical Procedures.” He omits the olfactory nerves from the cranial group, considering them a part of the brain. Out of loyalty to his teacher, Marinos, he numbers seven cranial nerves but actually identifies ten, misconstruing the fourth, omitting the sixth, and describing all the others. The sympathetic is linked with the trigeminal but most parts of it are described. The spinal nerves and their plexuses are briefiy but quite accurately described. He leaves no doubt that he identified these nerves anatomically and understood much of their function.
The fine structure of the stria vascularis of the cat inner ear
Authors: Hinojosa R. , Rodriguez‐Echandia E. L. 
Published: February 2005

AbstractThe fine structure of the cat stria vascularis was studied with the electron microscope. It consists of three layers of epithelial cells in close association with intraepithelial capillaries. The cells of the superficial row have a convex luminal surface bordering on the cochlear duct lumen. The apical cytoplasm contains numerous coated vesicles and vesicular invaginations which are interpreted as a type of micropinocytosis. Deep infoldings of the plasmalemma divide the lower two‐thirds of these cells into thin compartments containing numerous mitochondria. It is suggested that marginal cells are well adapted by their fine structure to participate in regulation of the ion composition of endolymph. The cells of the intermediate and basal rows have pale cytoplasm and numerous processes Ascending processes of the basal cells form cup‐like structures which partially isolate each apical cell from the rest of the epithelium.The endothelium of the strial capillaries is not remarkable and no discontinuities of the endothelial lining were observed. The endothelial basement lamina sends out numerous extensions into a system of interconnected extracellular passages that permeate the epithelium. These are interpreted as pathways for the rapid diffusion of materials from the capillaries.
On the occurrence of a fibrous lamina on the inner aspect of the nuclear envelope in certain cells of vertebrates
Authors: Fawcett Don W. 
Published: February 2005

AbstractThe fine structure of the fibrous lamina on the inner aspect of the nuclear envelope in cells of various invertebrates is reviewed, and attention is drawn to the common occurrence of a similar but thinner layer in nuclei of cells in vertebrates. Certain superficial similarities are pointed out in the relations of fibrous lamina to the nuclear pores and of the basement lamina to the endothelial capillary pores. It is suggested that in future considerations of the physiological exchange of materials between nucleoplasm and cytoplasm the properties of the fibrous lamina must be taken into account.
Bone fractures produced by high velocity impacts
Authors: Huelke Donald F. , Buege Lynn J. , Harger James H. 
Published: February 2005

AbstractThe effects of high velocity impact to the distal end of 122 human femurs were studied using one‐quarter inch steel spheres as projectiles, with impact velocities from 500 to 1700 feet per second. In the lower velocity range, a “drill hole” fracture was produced with low energy expenditure, and the diameter of this type of fracture was increased as a function of increasing velocity. At the higher impact velocities the bone exploded with a violent radial displacement of the material surrounding the missile path, similar to the cavitation effect often seen in soft tissues. At increasing impact velocities, increasing amounts of energy were expended in producing the fracture.
Morphogenesis of the palate in normal human embryos with special emphasis on the mechanisms involved
Authors: Burdi Alphonse R. , Faist Kathleen 
Published: February 2005

AbstractThe aim of this study was to re‐evaluate the classical description of fusion as the closure mechanism of both the hard and soft palates in normal human embryos. Does the soft palate develop by a posterior continuation of shelf apposition, epithelial lamination and disintegration, and by mesenchymal cell fusion as described for the hard palate? Or does the soft palate develop by proliferation and migration of subepithelial mesenchymal growth centers at the posterior edge of the fused hard palate so that the early furrow which separates the two primordial processes of the soft palate is progressively obliterated by mesenchymal merging at the furrow base?Observations of human embryos prior to, during, and after palatal closure (7–12 wks, 18–75 mm C‐R length) indicated (1) an anteroposterior gradient of palatal closure beginning at the primary palate and (2) epithelial fusion remnants found only in the hard palate regions. These observations suggest that the soft palate develops by a displacement of epithelium by mesenchymal merging rather than by epithelial fusion of the entire secondary palatine processes.
The development of the facial muscles in man
Authors: Gasser Raymond F. 
Published: February 2005

AbstractMorphogenesis and histogenesis of the facial muscles is described in human embryos and fetuses 4.2–360.0 mm (crown‐rump length). The microscopic study was performed on 50 specimens that had been variously serially‐sectioned and stained. Graphic or wax reconstructions were made from transverse serial sections at 11 representative ages. Three late fetuses and a term infant were studied grossly.Second branchial arch mesenchyme in early embryos (4.2–6.5 mm) becomes increasingly dense, but is not subdivided into distinct premuscle masses. By 8–20 mm, sheet‐like collections (laminae) of premyoblasts and early myoblasts extend from the superficial part of the arch into the temporal, occipital, cervical and mandibular regions. Premuscle condensations deep in the arch become the stapedius, posterior digastric and stylohyoid muscles. The infraorbital lamina and the occipital platysma appear by 20–23 mm. The superficial muscles differentiate rapidly between 26 and 37 mm. Most are composed of myoblasts at 41 mm. By 80 mm, all the muscles contain myotubes and are in their definitive positions. At 80–140 mm, the myotubes become young muscle fibers. From 140 mm to 360 mm (term) the muscles increase in size and gain definitive attachments. Superficial muscles differentiate later than the deep and those in the cervicomandibular and occipital regions differentiate earlier than those in the frontal and midfacial regions. The muscle masses form pari passu with the muscular branches of the facial nerve which develop deep to them.
A light and electron microscopic study of the pecten of the pigeon eye
Authors: Raviola Elio , Raviola Giuseppina 
Published: February 2005

AbstractThe pecten in the pigeon is a pleated lamina that consists of blood vessels and interstitial pigment cells. Arterioles with thin, unspecialized endothelium give origin to an exceedingly dense capillary network. The endothelial cells of the capillaries are provided on both the luminal and basal surfaces with thin lamellar processes, constricted at their origins from the cell body. Luminal lamellae are long, erect and have a prevailing longitudinal orientation. Basal lamellae are shorter, more irregularly oriented and more closely compressed. Besides the usual complement of cytoplasmic organelles, a moderate number of coated vesicles and of coated and uncoated inpocketings of the plasmalemma is present in the endothelial cells. A labyrinthine system of interstices surrounds the stalks of the basal lamellae and contains a material that resembles the substance of the basement lamina in density and texture. A similar material is found on the outer surface of the basal lamellae and imperceptibly merges with the ground substance of an unusually thick adventitial layer that is permeated by numerous unit fibrils of collagen. The capillary network is drained by venules, whose wall resembles the capillary wall. The pigment cells contain melanin granules, large mitochondria and many bundles of filaments. They are sandwiched between two basement laminae and separate the blood vessels from the vitreous body. The bridge of the pecten consists of pigment cells with a few interspersed capillaries.