bluuebunny/crossref_metadata_2025_split huggingface dataset:
Branchial innervation
Authors: Sundin Lena , Nilsson Stefan 
Published: August 2002

AbstractInspection of the dorsal end of fish gills reveals an impressive set of nerve trunks, connecting the gills to the brain. These trunks are branches of cranial nerves VII (the facial) and especially IX (the glossopharyngeal) and X (the vagus). The nerve trunks carry a variety of nervous pathways to and from the gills. A substantial fraction of the nerves running in the branchial trunks carry afferent (sensory) information from receptors within the gills. There are also efferent (motor) pathways, which control muscles within the gills, blood flow patterns and possibly secretory functions. Undertaking a more careful survey of the gills, it becomes evident that the arrangement of the microanatomy (particularly the blood vessels) and its innervation are strikingly complex. The complexity not only reflects the many functions of the gills but also illustrates that the control of blood flow patterns in the gills is of crucial importance in modifying the efficiency of its chief functions: gas transfer and salt balance. The “respiratory–osmoregulatory compromise” is maintained by minimizing the blood/water exchange (functional surface area of the gills) to a level where excessive water loss (marine teleosts) or gain (freshwater teleosts) is kept low while ensuring sufficient gas exchange. This review describes the arrangement and mechanisms of known nervous pathways, both afferent and efferent, of fish (notably teleosts) gills. Emphasis is placed primarily on the autonomic nervous system and mechanisms of blood flow control, together with an outline of the afferent (sensory) pathways of the gill arches. © 2002 Wiley‐Liss, Inc.
Retinal photoreceptors and visual pigments in Boa constrictor imperator
Authors: Sillman Arnold J. , Johnson Jacqueline L. , Loew Ellis R. 
Published: August 2002

AbstractThe photoreceptors of Boa constrictor, a boid snake of the subfamily Boinae, were examined with scanning electron microscopy and microspectrophotometry. The retina of B. constrictor is duplex but highly dominated by rods, cones comprising 11% of the photoreceptor population. The rather tightly packed rods have relatively long outer segments with proximal ends that are somewhat tapered. There are two morphologically distinct, single cones. The most common cone by far has a large inner segment and a relatively stout outer segment. The second cone, seen only infrequently, has a substantially smaller inner segment and a finer outer segment. The visual pigments of B. constrictor are virtually identical to those of the pythonine boid, Python regius. Three different visual pigments are present, all based on vitamin A1. The visual pigment of the rods has a wavelength of peak absorbance (λmax) at 495 ± 2 nm. The visual pigment of the more common, large cone has a λmax at 549 ± 1 nm. The small, rare cone contains a visual pigment with λmax at 357 ± 2 nm, providing the snake with sensitivity in the ultraviolet. We suggest that B. constrictor might employ UV sensitivity to locate conspecifics and/or to improve hunting efficiency. The data indicate that wavelength discrimination above 430 nm would not be possible without some input from the rods. J. Exp. Zool. 290:359–365, 2001. © 2001 Wiley‐Liss, Inc.
Covariance of ion flux measurements allows new interpretation of Xenopus laevis oocyte physiology
Authors: Faszewski Ellen E. , Kunkel Joseph G. 
Published: August 2002

AbstractAn animal‐vegetal net ionic current identified previously using voltage probe techniques in maturing Xenopus laevis oocytes has now been investigated using noninvasive ion‐selective microelectrodes. Three‐dimensional fluxes of hydrogen (H+), potassium (K+), and bicarbonate (HCO3–) were characterized with respect to the developmental stage and hemisphere of the oocyte and presence of surrounding follicular tissue. Variable effluxes of H+ and HCO3– were recorded from both the animal and vegetal hemispheres. Variable influxes and effluxes of K+ were also observed. The equatorial region, silent by voltage probe, exhibited fluxes of H+ and K+. Simultaneous measurement of pairs of ions allowed correlation analysis of two ion types. Notably for H+ and K+ data, positive and negative correlation at animal and vegetal poles respectively offer an explanation of the unpredictable results obtained when individual ions were observed independently. J. Exp. Zool. 290:652–661, 2001. © 2001 Wiley‐Liss, Inc.
Aid policies and growth: in search of the holy grail
Authors: Hudson John , Mosley Paul 
Published: August 2002

AbstractIn this paper we consider the hypothesis that aid effectiveness can be linked to ‘good policies’ and thus that aid, if it is to have maximum impact, should be directed at countries following good policies. This is an idea which we have considerable sympathy with in principle and have built upon in the past. Indeed at one level it is almost a truism and yet in practice we find little empirical evidence in support of it when we restrict good policies to mean free market policies. ‘Good policies’ appear to matter in stimulating growth, but they do not appear to impact on aid effectiveness. Unlike much of other recent work the analysis is of a simultaneous system of equations of which growth is just one. The results suggest a complex interaction between macroeconomic variables and good policies, but it also suggests the need to widen our definition of good policies to increase both the theoretical and empirical relevance of the hypothesis. Copyright © 2001 John Wiley & Sons, Ltd.
Multi‐national corporations and agricultural development: a study of contract farming in the Indian Punjab
Authors: Singh Sukhpal 
Published: August 2002

AbstractThis paper examines the rationale, practice and implications of contract farming under the MNCs in vegetable crops in the Indian Punjab from the new institutional economics perspective. It is found that the MNCs deal with relatively large producers, their contracts are biased against the farmer, and the contract crops perpetuate many of the existing problems of the farming sector like high chemical input intensity, unstable future incomes, and social differentiation, though contracting has led to higher farm incomes and labour employment, especially for women. There is an inherent contradiction in the objectives of the contracting parties and that of the local economy and suitable institutions and organisations are not present in the state. Copyright © 2002 John Wiley & Sons, Ltd.
Origin of evolutionary novelty: Examples from limbs
Authors: Shubin Neil H. 
Published: August 2002

AbstractClassic hypotheses of vertebrate morphology are being informed by new data and new methods. Long nascent issues, such as the origin of tetrapod limbs, are being explored by paleontologists, molecular biologists, and functional anatomists. Progress in this arena will ultimately come down to knowing how macroevolutionary differences between taxa emerge from the genetic and phenotypic variation that arises within populations. The assembly of limbs over developmental and evolutionary time offers examples of the major processes at work in the origin of novelties. Recent comparative developmental analyses demonstrate that many of the mechanisms used to pattern limbs are ancient. One of the major consequences of this phenomenon is parallelism in the evolution of anatomical structures. Studies of both the fossil record and intrapopulational variation of extant populations reveal regularities in the origin of variation. These examples reveal processes acting at the level of populations that directly affect the patterns of diversity observed at higher taxonomic levels. J. Morphol. 252:15–28, 2002. © 2002 Wiley‐Liss, Inc.
Are Echiura derived from a segmented ancestor? Immunohistochemical analysis of the nervous system in developmental stages of Bonellia viridis
Authors: Hessling René , Westheide Wilfried 
Published: August 2002

AbstractDespite several unquestionably homologous characters with Annelida, the Echiura have generally been considered to form a distinct taxon due to apparent lack of segmentation: neither in the body cavity nor in any other structures of the adult animals have clear signs of a metameric organization been observed. However, it must be considered that this lack of segmentation could represent a secondary condition and that Echiura are derived from segmented ancestors. An immunohistochemical analysis visualized with confocal laser‐scanning microscopy (cLSM) shows the development of serially repeated units in the nervous system of Bonellia viridis. This organization corresponds to the metameric ganglia typical of Annelida. Antibodies against the neurotransmitters serotonin (5‐hydroxytryptamine) and FMRFamide label distinct subsets of neurons. Their perikarya are arranged in discrete repetitive units in the ventral nerve cord of different larval stages. Labeling of neurotubuli using antibodies against different tubulin isoforms provides additional support for the metameric character of the nervous system. Contrary to previous descriptions, the peripheral nerves extending from the ventral nerve cord into the body wall musculature are paired and are evenly distributed; their arrangement corresponds to that of the serotoninergic perikarya. Morphological and neurochemical differentiation of the nervous system clearly proceeds from anterior to posterior, indicating the occurrence of a posterior growth zone. The serial ganglionic organization of the nervous system of Articulata is generally regarded as having evolved in conjunction with repetitive muscular units, in particular with the formation of typical annelid segments. Therefore, these results are interpreted as an indication that Echiura are derived from segmented ancestors and thus support the systematic inclusion of the Echiura within the Annelida. J. Morphol. 252:100–113, 2002. © 2002 Wiley‐Liss, Inc.
Quantitative measurements of cerebral blood flow in patients with unilateral carotid artery occlusion: A PET and MR study
Authors: Lin Weili , Celik Azim , Derdeyn Colin , An Hongyu , Lee Yueh , Videen Tom , Ostergaard Leif , Powers William J. 
Published: August 2002

AbstractAlthough it has been demonstrated that quantitative measures of cerebral blood flow (CBF) can be obtained with the singular value decomposition (SVD) algorithm, the extent to which quantitative CBF measurements can be utilized under pathophysiological conditions has not been systematically studied. A total of five healthy volunteers and five patients with unilateral carotid artery occlusion were studied. Only magnetic resonance (MR) images were acquired for the volunteer group while both MR and positron emission tomography (PET) images were acquired for the patient group. Assessments of CBF from normal volunteers compared favorably with values reported in the literature. However, while a linear relationship was observed for each patient when MR measured CBF was compared to that obtained from PET, this linear relationship diminished when all patients were analyzed as a group (r = 0.41). A correction factor (CF) was proposed that was equal to the ratio of the area of the venous output function (VOF) in each patient to the mean VOF obtained from the volunteer group. After globally scaling the CBF of each patient based on the experimentally derived CF, a substantial improvement was observed (a slope of 1.02 and r = 0.8 for the linear regression line) in the relationship between MR estimated CBF and those obtained from PET. J. Magn. Reson. Imaging 2001;14:659–667. © 2001 Wiley‐Liss, Inc.
MRI‐guided thermal therapy of transplanted tumors in the canine prostate using a directional transurethral ultrasound applicator
Authors: Hazle John D. , Diederich Chris J. , Kangasniemi Marko , Price Roger E. , Olsson Lars E. , Stafford R. Jason 
Published: August 2002

AbstractPurposeTo evaluate MRI‐based techniques for visual guidance, thermal monitoring, and assessment during transurethral ultrasound thermal therapy of implanted tumors in an in vivo canine prostate model.Materials and MethodsTransmissible venereal tumors (TVT) were grown in the right lobe of the prostate in four dogs. High‐temperature thermal therapy was selectively applied to the tumor‐bearing lobe using a transurethral ultrasound applicator with a 180° directional heating pattern. Temperature‐sensitive MRI (MRTI) using a fast interleaved gradient‐echo echo‐planar (iGE‐EPI) imaging sequence was used for cumulative thermal dose calculations in multiple image planes during the treatment. The results from MRTI‐based dose maps and post‐treatment MRI were compared to those from histologic analysis.ResultsMRTI monitoring in multiple planes across the prostate guided the use and control of a directive ultrasound applicator for the selective ablation of the sections of the prostate that contained implanted tumors. Findings in gadolinium enhanced MRI obtained immediately after thermal therapy slightly underestimated the size of tissue necrosis after treatment, as verified by histopathologic analysis.ConclusionThe use of multiplanar MRTI with a transurethral ultrasound applicator shows significant potential for selective thermal ablation of prostate tumor and tissue. J. Magn. Reson. Imaging 2002;15:409–417. © 2002 Wiley‐Liss, Inc.
Evaluation of the anatomical and functional properties of deglutition with various kinetic high‐speed MRI sequences
Authors: Anagnostara A. , Stoeckli S. , Weber O.M. , Kollias S.S. 
Published: August 2002

AbstractWe evaluated various fast MR sequences for obtaining anatomical and dynamic functional information during deglutition. Seven healthy volunteers underwent MRI of the oropharynx during swallowing of an oral positive‐contrast agent. Single‐slice imaging was performed in the median sagittal plane while subjects were in a supine position. Twenty serial images were obtained using EPI, FLASH, and turbo‐FLASH sequences. The dynamic (movement‐related) information and the anatomical resolution of the soft tissues were evaluated during deglutition. The FLASH sequence provided high‐quality images at rest. During swallowing, however, the images were significantly degraded by movement artifacts and had inferior temporal resolution. The EPI evidenced better temporal resolution, but was degraded by strong distortions and movement artifacts. The turbo‐FLASH sequence provided the best temporal resolution and sufficient spatial resolution during motion. This sequence proved optimal for the investigation of swallowing function, and is expected to be of value for the documentation of functional disturbances in patients with oropharyngeal pathology. J. Magn. Reson. Imaging 2001;14:194–199. © 2001 Wiley‐Liss, Inc.
The metabolism of norethandrolone in the horse: characterization of 16‐, 20‐ and 21‐oxygenated metabolites by gas chromatography/mass spectrometry
Authors: McKinney Andrew R. , Ridley Damon D. , Suann Craig J. 
Published: August 2002

AbstractAfter oral administration to a thoroughbred gelding, the anabolic steroid norethandrolone was converted into a complex mixture of oxygenated metabolites. These metabolites were extracted from the urine, deconjugated by methanolysis and converted to their O‐methyloxime trimethylsilyl derivatives. Gas chromatographic/mass spectrometric analysis indicated the major metabolites to be 19‐norpregnane‐3,16,17‐triols, 19‐norpregnane‐3,17,20‐triols and 3,17‐dihydroxy‐19‐norpregnan‐21‐oic acids. Some minor metabolites were also detected. Copyright © 2001 John Wiley & Sons, Ltd.
Identification and sequencing analysis of intact proteins via collision‐induced dissociation and quadrupole time‐of‐flight mass spectrometry
Authors: Nemeth‐Cawley Jennifer F. , Rouse Jason C. 
Published: August 2002

AbstractIdentifying unknown proteins has become a central focal point for proteomic and biopharmaceutical development laboratories. Our laboratory investigated using quadrupole time‐of‐flight mass spectrometry (Qq/TOFMS) for the analysis of intact proteins for the purpose of identifying unknowns while limiting the number of sample‐handling steps between protein extraction and identification. Eight standard proteins, both unmodified and disulfide‐bonded and ranging in mass from 5 to 66 kDa, were analyzed using nanoelectrospray and collision‐induced dissociation to generate peptide sequence tags. An MS analysis, followed by MS/MS analyses on two to five individual protein charge states, were obtained to make an identification. Peptide sequence tags were extracted from the MS/MS data and used, in conjunction with molecular mass and source origin, to obtain protein identifications using the web‐based search engine ProteinInfo (www.proteometrics.com). All of the proteins were unambiguously identified from the input data, after which, all of the major product ions were identified for structural information. In most cases, N‐ and/or C‐terminal ions, and also stretches of consecutive product ions from the protein interior, were observed. This method was applied to the analysis and identification of an unknown detected via reversed‐phase high‐performance liquid chromatography. Copyright © 2002 John Wiley & Sons, Ltd.
Experimental hepatitis A virus infection in guinea pigs
Authors: Hornei Britt , Kämmerer Regine , Moubayed Pierre , Frings Werner , Gauss‐Müller Verena , Dotzauer Andreas 
Published: August 2002

AbstractAlthough many of the properties of hepatitis A virus (HAV) are known, several aspects of HAV pathogenesis are still not understood, such as the mechanism underlying the hepatotropism or HAV replication in extrahepatic sites. Detailed studies of these aspects were hampered mostly by the lack of accessible animal models, since only nonhuman primates are susceptible to experimental infections. An alternative animal model would also be of interest to assess the primary replication site and for the evaluation of the safety and efficacy of vaccines. A study was undertaken to determine whether HAV can infect guinea pigs and whether they are useful as a model for studying aspects of HAV pathogenesis and for the evaluation of vaccines. HAV variants adapted to primate or guinea pig tissue culture were used to inoculate guinea pigs intraperitoneally and by the oral route. The animals were observed for clinical disease, shedding of HAV in stools, viremia, seroconversion, evidence for liver damage by biochemical liver function tests, virus presence in the liver, development of hepatic histopathological changes, and occurrence of HAV in extrahepatic organs. The animals developed an active, clinically inapparent infection with specific histopathological changes in the liver. Although virus replication occurred, as shown by RT‐PCR and isolation of infectious virus from feces and serum, it seems unlikely that guinea pigs are suitable for studying the clinical features of hepatitis A, because the clinical and laboratory parameters remained normal. However, guinea pigs appear useful for studying some aspects of HAV pathogenesis and for testing the safety of vaccines. J. Med. Virol. 64:402–409, 2001. © 2001 Wiley‐Liss, Inc.
Chronic hepatitis C infection: Influence of the viral load, genotypes, and GBV‐C/HGV coinfection on the severity of the disease in a Brazilian population
Authors: Pereira Leila M.M.B. , Spinelli Victorino , Ximenes Ricardo A. , Cavalcanti Maria S. , Melo Raul , Jucá Norma , Mizokami Masashi , McFarlane Ian G. 
Published: August 2002

AbstractThe distributions of the different genotypes of the hepatitis C virus (HCV) and GBV‐C virus (GBV‐C/HGV) vary geographically and information worldwide is still incomplete. In particular, there are few data on the distribution of genotypes (and their relationship to the severity of liver disease) in South America. Findings are described in 114 consecutive patients from Northeast Brazil (median age 52 years, range 18–72 years) who had abnormal levels of serum aminotransferases and seropositivity for HCV RNA. The patients were recruited from an outpatient clinic between November 1997 and April 1998. Quantitative HCV RNA and GBV‐C/HGV RNA estimations were carried out by double‐nested polymerase chain reaction (PCR) using primers from the 5′‐untranslated regions (UTRs) of the genomes. HCV genotypes were determined by restriction fragment length polymorphism (RFLP) analysis with 5′‐UTR primers and by PCR with type‐specific 5′‐UTR primers. GBV‐C/HGV‐RNA genotypes were determined by RFLP with specific 5′‐UTR primers and phylogenetic trees were constructed using the Neighbour‐Joining and Drawtree programs. Histological features were graded and staged according to international criteria. Of the 114 patients, 35 (30.7%) patients had cirrhosis and 22 (27.8%) had mild, 51 (64.6%) had moderate, and 6 (7.6%) had severe chronic hepatitis. Median HCV viral load was 106 genome equivalents per millilitre (range 104–109/ml). Frequencies of genotypes were 5.3% type 1a, 44.7% type 1b, 3.5% type 2, 41.2% type 3, and 5.3% mixed types. GBV‐C/HGV‐RNA was detected in the sera of 12 (10.5%) patients and was distributed among three phylogenetic groups. There were no significant differences between patients with the predominant HCV genotypes (1b and 3) with respect to gender, age group, viral load, severity of liver disease, or coinfection with GBV‐C/HGV. J. Med. Virol. 67:27–32, 2002. © 2002 Wiley‐Liss, Inc.
Expression of mRNA for plasminogen activators and protease nexin‐1 in innervated and denervated mouse skeletal muscle
Authors: Magnusson Caroline , Högklint Lars , Libelius Rolf , Tågerud Sven 
Published: August 2002

AbstractPlasminogen activators (urokinase‐type, u‐PA and tissue‐type, t‐PA) are serine proteases that have been suggested to play important roles in synaptic remodeling. The enzymatic activity of u‐PA in particular has previously been shown to increase dramatically after denervation of skeletal muscle. Using 32P‐labeled riboprobes and Northern blots the expression of mRNA for u‐PA, t‐PA and the inhibitor protease nexin‐1 (PN‐1) has been studied in innervated and 1–10‐days denervated hind‐limb muscle from mouse. Using RNA extracted from innervated and 6‐days‐denervated mouse hemidiaphragm muscles the expression of these mRNAs has also been investigated in synaptic and extrasynaptic muscle regions. For both u‐PA and t‐PA the observed autoradiographic signals were similar for RNA extracted from innervated and denervated leg muscles. The signals were also similar for RNA extracted from perisynaptic and extrasynaptic regions of hemidiaphragm muscle but u‐PA signals were lower in denervated than in innervated hemidiaphragm. No such difference was observed for t‐PA. PN‐1 mRNA levels were also found to decrease after denervation in the hemidiaphragm but no substantial decrease was observed in denervated hind‐limb muscles. No difference was observed between PN‐1 expression in perisynaptic and extrasynaptic regions. The effect of denervation on PA enzymatic activity in skeletal muscle is therefore likely to be mediated at some post‐transcriptional level. J. Neurosci. Res. 66:457–463, 2001. © 2001 Wiley‐Liss, Inc.