bluuebunny/crossref_metadata_2025_split huggingface dataset:
An electron microscopic study of the cardiac innervation in larval lamprey
Authors: Nakao Taisuke , Suzuki Satoru , Saito Mitsuo 
Published: February 2005

AbstractLarval lampreys (Lampetra japonica) 13 and 21 mm in body length were examined by serial section electron microscopy and it was found that the young 13‐mm larvae which was 26 days old had no nerves to, and in, the heart. However, the heart of 21‐mm larval lampreys had two sets of nerve fibers entering the heart. One of the nerve fibers entered the heart via the porta venosa, ran along the vena jugularis impar, and ended in the sinus venosus. The other nerve entered with the porta arteriosa and terminated in the proximal region of the bulbus cordis. Two characteristic types of nerve endings were observed. One type of nerve ending contained numerous, small, clear vesicles about 40 nm in diameter. These endings were found only in the walls of the vena jugularis impar and the sinus venosus. The second type of ending characteristically contained distinctive large‐cored vesicles 60–130 nm in diameter mixed with numerous small, clear vesicles. These endings were present in the walls of the vena jugularis impar, the sinus venosus, and the bulbus cordis. It should be emphasized that the bulbus contained only the second type of nerve ending. The nerves in the heart were confined to specific regions and those from the two sources remained separate. Furthermore, the atrium, ventricle, ducts of Cuvier, and hepatic veins were completely devoid of nerves. There were no ganglion cells in any region of the heart.
Methods for the isolation of intact epithelium from the mouse intestine
Authors: Bjerknes Matthew , Cheng Hazel 
Published: February 2005

AbstractMethods are described for the isolation of intact intestinal epithelium in several novel forms. The first method described is for application to segments of bowel that must be studied without killing the animal, e.g., a resected length of bowel. In this method, the isolated segment is everted onto a glass rod and incubated at 37°C in fresh 30 mM ethylenediaminetetraacetic acid (EDTA) in calcium‐magnesium‐free Hank's balanced salt solution (CMF) for either 15 or 20 minutes. At the end of the incubation, the epithelium is isolated by vibration into a tube of cold CMF. If it is incubated for 20 minutes, the entire epithelium is isolated in the form of single crypt‐villus units. If it is incubated for 15 minutes, the epithelium is isolated in the form of small intact sheets, but not all of the epithelium is removed.The second method requires the death of the animal but yields better results. The anesthetized animal is perfused through the left ventricle with a fresh 37° solution of EDTA (0.01–30 mM) in CMF. Then the segment of gut is removed, everted onto a glass rod, and the epithelium isolated by vibration into cold CMF. The whole of the epithelium is isolated with this procedure and, with higher concentrations of EDTA, it is isolated in the form of large sheets (1–2 cm2). Structurally inact units could be obtained with either procedure. There was no contamination with underlying nonepithelial elements.The best results, as determined by morphology and viability, were obtained with the perfusion method using 30 mM EDTA. With this concentration, the whole procedure, from sacrifice of the animal to isolation of the epithelium, requires less than 4 minutes. Procedures are also described for the isolation of either pure intact crypts or of pure intact vill from small intestine. Each of the methods described could be used to isolate the epithelium from any region of the intestinal tract with equal ease. Some applications of the methods are also discussed.
The behavior of substances labeled with 3H‐proline and 3H‐fucose in the cellular processes of odontoblasts and ameloblasts
Authors: Warshawsky H. , Josephsen K. 
Published: February 2005

AbstractOdontoblasts are cells with single cytoplasmic processes that grow longer as more dentin is elaborated. Ameloblasts also have single processes and it has been postulated that they too grow longer as more enamel is made. Support for this hypothesis was obtained using rat incisors to investigate the behavior of substances labeled with 3H‐proline and 3H‐fucose. A comparison was made between odontoblasts, which have processes known to grow and remain within the dentin, and the ameloblasts whose Tomes' processes are hypothesized to grow and leave remnants in the completed enamel. With 3H‐proline, the odontoblast bodies are labeled at the early time intervals. They synthesize and secrete a layer of intensely labeled predentin, which by 1 and 2 days is converted to mineralized dentin. Matrix deposited after the main pulse is weakly labeled. Odontoblast processes are never labeled in dentin formed prior to injection. With 3H‐fucose, the cell bodies are labeled at the early intervals and the newly formed glycoproteins are deposited into the predentin. Almost immediately, these are progressively added to the dentin at the calcification front. With time a gradient of labeling extends from the unlabeled dentin toward the odontoblast bodies. Unlike the behavior of labeled proteins, by 1 and 2 days labeled glycoproteins appear along the entire length of the odontoblast processes. In the enamel, no Tomes' processes are present during maturation. With 3H‐proline, reactions are adjacent to the cells and diffuse toward, but do not reach the dentino‐enamel junction by 1 and 2 days. With 3H‐fucose, reactions appear over the enamel near the cells. By 1 and 2 days no diffusive pattern is seen, but grains are concentrated near the dentino‐enamel junction, in a region containing holes known to be the beginning of Tomes' processes. Since odontoblast glycoproteins migrate along odontoblast processes, it was postulated that cytoplasmic remnants were present in enamel along which ameloblast glycoproteins could also migrate to reach the holes at the dentino‐enamel junction.
Effects of acid‐stress on epidermal mucous cells of the brown bullhead Ictalurus nebulosus (LeSeur): A morphometric study
Authors: Zuchelkowski Edwin M. , Lantz R. Clark , Hinton David E. 
Published: February 2005

AbstractThe effects of acid water on alcian blue‐periodic acid Schiff's stainable mucosubstances of epidermis from theanterior abdominal wall of brown bullhead catfish, Ictalurus nebulosus, were studied. Standard morphometric techniques were used to determine mucous cell volume density (MCVv) and number density (MCNv) of control (pH 6.8–7.0) and acid‐stressed (pH 5.7–6.15) fish. Mucous cell volume density was significantly increased (P < 0.005) in fish which had been exposed to acid‐stress for five days. Since increase in volume density can arise from either an increase in the size of individual mucous cells (hypertrophy), an increase in the number of mucous cells per unit volume (hyperplasia), or a combination of the two, average cell data were computed. No significant difference in cell diameter or cell volume between treated and control groups was seen. However, the number of mucous cells in acid‐stressed fish was nearly twice (P < 0.005) that of controls. These results demonstrated that acid‐stress resulted in increased number but not volume of mucous cells (i.e., hyperplasia without hypertrophy).
Ultrastructural evidence indicating reorganization at the neuromuscular junction in the normal rat soleus muscle
Authors: Cardasis Constance Ann , Padykula Helen A. 
Published: February 2005

AbstractThe ultrastructural organization of 40 soleus neuromuscular junctions from ten normal young adult male and female Sprague‐Dawley (SD)‐derived rats (Charles River Breeders, CD‐Crl:COBS (SD)BR) has been studied. A smaller sample of motor endplates from the gastrocnemius, diaphragm, and extensor digitorum longus muscles of these rats as well as from the soleus muscles of two adult Wistar (W) rats (Crl:COBS(WI)BR) was included. Widespread ultrastructural reorganization was evident at the soleus neuromuscular junction during the growth period from three to five months of age. A major characteristic of reorganization is the presence of junctional folds not associated with axonal terminals; such sites occur within a single endplate adjacent to areas with typical intact synaptic associations. Additional features possibly related to remodelling are: (1) spatial separation of axonal terminals from the myofiber, (2) intervention of Schwann cell cytoplasm between an axon terminal and myofiber, (3) aggregates of satellite cells, and (4) folded or multilayered basal lamina. These features are most pronounced in the soleus muscle but occur to varying degrees in the neuromuscular junctions of other muscles of SD‐derived rats.Distinctive characteristics of the rat soleus postjunctional sarcoplasm include the widespread occurrence of myofibrillar components, abundant free and membrane‐associated polysomes, and triads oriented in various planes. Away from such discrete sites, myofibers possess the usual highly oriented organization of myofibrils, T tubules, sarcoplasmic reticulum, and mitochondria.The soleus muscle is a postural muscle that responds directly to rising workload imposed by continuous body growth during young adulthood by steady myofiber hypertrophy and conversion of motor units (Kugelberg, '76). This changing structural‐functional relationship may be reflected also by ultrastructural remodelling of the neuromuscular junctions reported here.
Prenatal and postnatal development of the cervical portion of the spine in the short‐finned pilot whale Globicephala macrorhyncha
Authors: Ogden John A. , Lee Kendrick E. , Conlogue Gerald J. , Barnett James S. 
Published: February 2005

AbstractFusion of the cervical spine in Globicephala macrorhyncha is a prenatal rather than postnatal phenomenon which encompasses all cervical vertebra. This results in a relatively short, nonarticulated, composite cervical spine in this particular species. Cervicothoracic spine segments removed from fetuses demonstrated complete fusion of all cervical vertebra commencing during early prenatal development. C1 and C2 initially developed as a composite central cartilaginous unit, although laterally there was some separation through rudimentary interzone formation. However, C3 through C7 formed individual cartilaginous centra which were divided from each other by thin, well‐demarcated interzones, but without the formation of intervertebral discs (which were concomitantly evident dividing the thoracic, lumbar, and caudal vertebra, and were also present between the seventh cervical and first thoracic vertebra, although this was a very rudimentary intervertebral region). The first primary ossification center appeared in C2. Subsequently, primary ossification occurred in C7, and finally in C2 through C6, with ossification progressing in a craniocaudal fashion in these four vertebra. The centra ossification centers then progressively coalesced in the midline, from C2 to C7, in a craniocaudal sequence. This entire chondroosseous fusion process was completed during early gestation (probably less than 2 to 3 months of prenatal development), so that a composite “single” cervical vertebra developed that characterizes this species at birth and throughout postnatal development. Postnatally, ossification spreads laterally within each centrum, and also progressively removes the vestiges of the intervertebral material. C7 also develops a secondary ossification center, but only in the caudal region. The cranial end of C7 and the remainder of the cervical vertebra do not form secondary centers. An extensive fibrocartilaginous/hyaline cartilage bridge remains between C1 and C2, even after closure of the vertebral physes. Undoubtedly, this allows continued growth in C1 and C2, which become the dominant portion of the cervical unitary vertebra. Eventually, even this synchondrosis will disappear to form a completely osseous cervical mass.
Membrane‐type 1 matrix metalloproteinase is required for normal alveolar development
Authors: Atkinson Jeffrey J. , Holmbeck Kenn , Yamada Susan , Birkedal‐Hansen Henning , Parks William C. , Senior Robert M. 
Published: February 2005

AbstractMatrix metalloproteinases (MMPs) are expressed during lung development, but their role may be limited, as mice deficient in MMP‐3, 7, 9, or 12 develop a normal adult lung. Because membrane‐type 1 matrix metalloproteinase (MT1‐MMP) is expressed in the developing lung epithelium, we examined the lung structure of MT1‐MMP–deficient (−/−) mice. Branching morphogenesis was normal, but alveolar development was abnormal in the MT1‐MMP−/− lungs with 40% less alveolar surface area at 1 month (P < 0.01). MT1‐MMP−/− airways and alveoli had an abnormal ultrastructural appearance, but epithelial cell differentiation markers were distributed similarly in both strains. There was no evidence of excess extracellular matrix deposition or inflammation at the time points examined. In contrast, by adulthood MMP‐2−/− mice had normal alveolar size and structure, indicating normal alveolar development was not dependent on the ability of MT1‐MMP to activate pro–MMP‐2. These data indicate that MT1‐MMP is required for normal lung development. Developmental Dynamics 232:1079–1090, 2005. © 2005 Wiley‐Liss, Inc.
Optically Active Poly[{methyl(1‐naphthyl)silylene}(o‐phenylene)methylene]‐Poly(ethylene glycol) Block Copolymer Micelles
Authors: Park Sung Young , Kawakami Yusuke 
Published: February 2005

AbstractSummary: Optically pure (+) and isotactic poly[{methyl(1‐naphthyl)silylene}(o‐phenylene)methylene] terminated with methylphenylchlorosilyl was obtained by the Pt‐catalyzed ring‐opening polymerization of optically pure 1‐methyl‐1‐(1‐naphthyl)‐2,3‐benzosilacyclobut‐2‐ene in the presence of methylphenylchlorosilane as a chain transfer agent. The polymer formed was transformed into a block copolymer by reacting the terminal chlorosilyl group with a commercial poly(ethylene glycol) monomethyl ether. The formation of micelles by the block copolymer in THF‐water mixtures was investigated by fluorescence and UV. More detailed information about the aggregation of the polymer in the micelles was obtained by circular dichroism spectroscopy. It was found that dense aggregates were formed at a concentration higher than the critical micelle concentration. This concentration was higher for lower molecular weight polymer, at higher temperatures, and in more hydrophobic solvent systems. The highly aggregated structure was altered by changing the solvent system.
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The production‐to‐respiration ratio and its implication in Lake Biwa, Japan
Authors: Urabe Jotaro , Yoshida Takehito , Gurung Tek Bahadur , Sekino Tatsuki , Tsugeki Narumi , Nozaki Kentaro , Maruo Masahiro , Nakayama Eiichioro , Nakanishi Masami 
Published: February 2005

AbstractProduction‐to‐respiration (P:R) ratio was estimated at an offshore site of Lake Biwa in order to examine whether the plankton and benthic community is subsidized with allochthonous organic carbon, and to clarify the role of this lake as potential source or sink of carbon dioxide. The respiration rate of protozoan and metazoan plankton was calculated from their biomass and empirical equations of oxygen consumption rates, and that of bacterioplankton was derived from their production rate and growth efficiency. In addition, the carbon mineralization rate in the lake sediments was estimated from the accumulation rate of organic carbon, which was determined using a 210Pb dating technique. On an annual basis, the sum of respiration rates of heterotrophic plankton was comparable to net primary production rate measured by the 13C method. However, when the mineralization rate in the lake sediments was included, the areal P:R ratio was 0.89, suggesting that Lake Biwa is net heterotrophic at the offshore site with the community being subsidized with allochthonous organic carbon. Such a view was supported by the surface water pCO2 that was on average higher than that of the atmosphere. However, the estimate of net CO2 release rate was close to that of carbon burial rate in the sediments. The result suggests that the role of Lake Biwa in relation to atmospheric carbon is almost null at the offshore site, although the community is supported partially by organic carbon released from the surrounding areas.
Distribution of population-based indicators across multiple taxa to assess the status of Gulf of Alaska and Bering Sea groundfish communities
Authors: Mueter Franz J. , Megrey Bernard A. 
Published: February 2005

AbstractEcosystem-based approaches to fisheries management require researchers and managers to take into account effects of fishing on other components of the ecosystem, including non-commercial species. Currently, stock assessments in the Northeast Pacific are limited to the most important commercial species, little being known about the status of non-commercial species. Nevertheless, standardized bottom-trawl surveys conducted in the eastern Bering Sea (EBS) and Gulf of Alaska (GoA), although primarily designed to assess commercial species, provide valuable information on the abundance, distribution, and mean weight of numerous taxa. Using a novel statistical approach and survey data for the years 1993–2003, we examined trends in catch per unit effort (cpue), frequency of occurrence, and mean weight of individuals for each taxon. Time trends were computed as the slope of a linear regression of each indicator on year, and were summarized separately for the eastern and western GoA and for the EBS. Within each system, trends were further compared between commercial and non-commercial taxa. Simulations were used to obtain reference distributions for the expected distribution of slopes across many dependent populations. Observed distributions of trends were compared with simulated distributions, suggesting that more taxa than expected showed a decreasing trend in cpue in the EBS, but not in the GoA. These trends likely resulted from low groundfish productivity in the EBS during the 1990s. At the same time, the frequency of occurrence of significantly more taxa than expected increased in the EBS and, to a lesser extent, in the western GoA. Increases in frequency of occurrence were much more common among non-commercial, invertebrate taxa, and may be a response to reductions in trawl fishing effort during the 1990s.
Comparison of pap smear, visual inspection with acetic acid, human papillomavirus DNA‐PCR testing and cervicography
Authors: De Vuyst H. , Claeys P. , Njiru S. , Muchiri L. , Steyaert S. , De Sutter P. , Van Marck E. , Bwayo J. , Temmerman M. 
Published: February 2005

AbstractObjectiveTo assess the test qualities of four screening methods to detect cervical intra‐epithelial neoplasia in an urban African setting.MethodSix hundred fifty‐three women, attending a family planning clinic in Nairobi (Kenya), underwent four concurrent screening methods: pap smear, visual inspection with acetic acid (VIA), PCR for high risk human papillomavirus (HR HPV) and cervicography. The presence of cervical intra‐epithelial neoplasia (CIN) was verified by colposcopy or biopsy.ResultSensitivity (for CIN2 or higher) and specificity (to exclude any CIN or cancer) were 83.3% (95% CI [73.6, 93.0]) and 94.6% (95% CI [92.6, 96.5]), respectively, for pap smear; 73.3% (95% CI [61.8, 84.9]) and 80.0% (95% CI [76.6, 83.4]) for VIA; 94.4% (95% CI [84.6, 98.8]) and 73.9% (95% CI [69.7, 78.2]) for HR HPV; and 72.3% (95% CI [59.1, 85.6]) and 93.2% (95% CI [90.8, 95.7]) for cervicography.ConclusionThe pap smear had the highest specificity (94.6%) and HPV testing the highest sensitivity (94.4%). The visual methods, VIA and cervicography, were similar and showed an accuracy in between the former two tests.
Transcarboxylase: One of Nature's Early Nanomachines
Authors: Carey Paul R. , Sönnichsen Frank D. , Yee Vivien C. 
Published: February 2005

AbstractThe enzyme transcarboxylase (TC) catalyzes an unusual reaction; TC transfers a carboxylate group from methylmalonyl‐CoA to pyruvate to form oxaloacetate and propionyl‐CoA. Remarkably, to perform this task in Propionii bacteria Nature has created a large assembly made up of 30 polypeptides that totals 1.2 million daltons. In this nano‐machine the catalytic machinery is repeated 6 ‐ 12 times over using ordered arrays of replicated subunits. The latter are sites of the half reactions. On the so‐called 12S subunit a biotin cofactor accepts carboxylate, ‐ CO2‐, from methylmalonyl‐CoA. The carboxylated‐biotin then translocates to a second subunit, the 5S, to deliver the carboxylate to pyruvate. We have not yet characterized the intact nanomachine, however, using a battery of biophysical techniques, we have been able to derive novel, and sometimes unexpected, structural and mechanistic insights into the 12S and 5S subunits. Similar insights have been obtained for the small 1.3S subunit that acts as the biotin carrier linking the 12S and 5S forms. Interestingly, some of these insights gained for the 12S and 5S subunits carry over to related mammalian enzymes such as human propionyl‐CoA carboxylase and human pyruvate carboxylase, respectively, to provide a rationale for their malfunction in disease related mutations.
IUBMB Life, 56: 575‐583, 2004
Detailed 3D seismic imaging of a fault zone beneath Lake Geneva, Switzerland
Authors: Scheidhauer M. , Marillier F. , Thierry P. 
Published: February 2005

AbstractAn efficient high‐resolution (HR) three‐dimensional (3D) seismic reflection system for small‐scale targets in lacustrine settings was developed. In Lake Geneva, near the city of Lausanne, Switzerland, the offshore extension of a complex fault zone well mapped on land was chosen for testing our system. A preliminary two‐dimensional seismic survey indicated structures that include a thin (<40 m) layer of subhorizontal Quaternary sediments that unconformably overlie south‐east‐dipping Tertiary Molasse beds and a major fault zone (Paudèze Fault Zone) that separates Plateau and Subalpine Molasse (SM) units.A 3D survey was conducted over this test site using a newly developed three‐streamer system. It provided high‐quality data with a penetration to depths of 300 m below the water bottom of non‐aliased signal for dips up to 30° and with a maximum vertical resolution of 1.1 m. The data were subjected to a conventional 3D processing sequence that included post‐stack time migration. Tests with 3D pre‐stack depth migration showed that such techniques can be applied to HR seismic surveys.Delineation of several horizons and fault surfaces reveals the potential for small‐scale geologic and tectonic interpretation in three dimensions. Five major seismic facies and their detailed 3D geometries can be distinguished. Three fault surfaces and the top of a molasse surface were mapped in 3D. Analysis of the geometry of these surfaces and their relative orientation suggests that pre‐existing structures within the Plateau Molasse (PM) unit influenced later faulting between the Plateau and SM. In particular, a change in strike of the PM bed dip may indicate a fold formed by a regional stress regime, the orientation of which was different from the one responsible for the creation of the Paudèze Fault Zone. This structure might have later influenced the local stress regime and caused the curved shape of the Paudèze Fault in our surveyed area.