bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impaired chemokine‐induced migration during T‐cell development in the absence of Jak 3
Authors: Soldevila Gloria , Licona Ileana , Salgado Alfonso , Ramírez Marcela , Chávez Ramsés , García‐Zepeda Eduardo 
Published: May 2004

SummaryThe arrival of bone marrow T‐cell progenitors to the thymus, and the directed migration of thymocytes, are thought to be regulated by the expression of chemokines and their receptors. Recent data has shown that the Jak\Stat signalling pathway is involved in chemokine receptor signalling. We have investigated the role of Jak 3 in chemokine‐mediated signalling in the thymus using Jak 3–\– mice. These mice show defects in T‐cell development, as well as in peripheral T‐cell function, resulting in a hypoplastic thymus and an altered T‐cell homeostasis. Here we demonstrate, for the first time, that bone marrow progenitors and thymocytes from Jak 3–\– mice have decreased chemotactic responses to CXCL12 and CCL25. We also show that Jak 3 is involved in signalling through CCR9 and CXCR4, and that specific inhibition of Jak 3 in wild‐type progenitors and thymocytes decreases their chemotactic responses towards CCL25 and CXCL12. Finally, quantitative reverse transcription–polymerase chain reaction analysis showed that thymocytes from Jak 3–\– mice express similar levels of CXCR4 and CCR9 compared to wild‐type mice. Altogether, deficient CCL25‐ and CXCL12‐induced migration could result in a homing defect of T‐cell progenitors to the thymus, as well as in a deficient thymocyte migration through the thymic stroma. Our results strongly suggest that the absence of Jak 3 affects T‐cell development, not only through an impaired interleukin‐7 receptor (IL‐7R)‐mediated signalling, but also through impaired chemokine‐mediated responses, which are crucial for thymocyte migration and differentiation.
Classical and alternative pathway complement activation are not required for reactive systemic AA amyloid deposition in mice
Authors: Hutchinson Winston L. , Herbert Jeff , Botto Marina , Pepys Mark B. 
Published: May 2004

SummaryDuring induction of reactive systemic amyloid A protein (AA) amyloidosis in mice, either by chronic inflammation or by severe acute inflammation following injection of amyloid enhancing factor, the earliest deposits form in a perifollicular distribution in the spleen. Because the splenic follicular localization of immune complexes and of the scrapie agent are both complement dependent in mice, we investigated the possible complement dependence of AA amyloid deposition. In preliminary experiments, substantial depletion of circulating C3 by cobra venom factor had little effect on experimental amyloid deposition. More importantly, mice with targeted deletion of the genes for C1q or for both factor B and C2, and therefore unable to sustain activation, respectively, of either the classical complement pathway or both the classical and alternative pathways, showed amyloid deposition similar to wild type controls. Complement activation by either the classical or alternative pathways is thus not apparently necessary for the experimental induction of systemic AA amyloid in mice.
The mechanism for activation of the neutrophil NADPH‐oxidase by the peptides formyl‐Met‐Leu‐Phe and Trp‐Lys‐Tyr‐Met‐Val‐Met differs from that for interleukin‐8
Authors: Fu Huamei , Bylund Johan , Karlsson Anna , Pellmé Sara , Dahlgren Claes 
Published: May 2004

SummaryNeutrophil chemotaxis has been shown to be regulated by two different signalling pathways that allow strong chemoattractants, such as bacterial‐derived formylated peptides, to dominate over endogenous attractants, such as interleukin‐8 (IL‐8). Here we show that triggering of the formyl peptide receptor (FPR) with f‐Met‐Leu‐Phe (fMLF) substantially reduced the neutrophil superoxide production induced by activation of the CXC receptors with IL‐8. When the order of agonists was reversed, the cells were primed in their response to fMLF, suggesting that the signalling hierarchy between strong, so‐called end‐type (i.e. fMLF) and weak or intermediate‐type (i.e. IL‐8) chemoattractants, is also operating during activation of the NADPH‐oxidase. The same result was obtained when fMLF was replaced with the hexapeptide, WKYMVM, specific for the formyl peptide‐like receptor 1 (FPRL1). There were additional differences between the agonist receptor pairs fMLF/FPR, WKYMVM/FPRL1 and IL‐8/CXCR. In contrast to FPR and FPRL1, no reserve pool of CXCR was present in subcellular granules and it was impossible to prime the oxidative response transduced through CXCR by the addition of priming agents such as tumour necrosis factor‐α and platelet‐activating factor. Moreover, the cytoskeleton‐disrupting substance, cytochalasin B, had no effect either on IL‐8‐triggered oxidase activation or on CXCR reactivation. A pertussis toxin‐sensitive G‐protein is involved in signalling mediated through both FPR and CXCR, and the signalling cascades include a transient intracellular calcium increase, as well as downstream p38 MAPK and phosphoinositide 3‐kinase activation. The data presented in this study provide support for two different signalling pathways to the neutrophil NADPH‐oxidase, used by ligand binding to FPR/FPRL1 or CXCR, respectively.
A Histological Study of the hph‐1 Mouse Mutant: an Animal Model of Phenylketonuria and Infantile Hypertrophic Pyloric Stenosis
Authors: Abel R. M. , Dorè C. J. , Bishop A. E. , Facer P. , Polak J. M. , Spitz L. 
Published: May 2004

Summary Aim: To quantify the chronological sequence of changes in the morphology and immunoreactivity for neurotransmitters in the pylorus of an animal model of infantile hypertrophic pyloric stenosis and phenylketonuria. Method: Thirty specimens of pylorus from hph‐1 mice and age/sex matched controls (age range: 10–180 days) were examined using conventional histology and immunohistochemistry for a variety of antigens: protein gene product 9.5, a pan neuronal marker; vasoactive intestinal polypeptide; nitric oxide synthase two antigens coalesced to the same inhibitory neurons in humans; substance P, a potent excitatory neurotransmitter; and calcitonin gene related peptide, a neurotransmitter implicated in the somatic afferent innervation of the stomach. The changes in the morphology of the muscle layers were quantified and statistically analysed for each age group (10, 20, 40, 90 and 180 days). Results: Between 10 and 90 days of age, all muscle layers of the hph‐1 mice were hypertrophied, for example, 10 days, hph‐1 longitudinal muscle mean diameter = 3.4, control = 1.8; hph‐1 circular muscle width = 11.5, control = 4.7. The hph‐1 mice were significantly smaller during this period (40 days, hph‐1 weight = 10 g, control = 25 g). There was no change in the pattern of expression of the antigens examined within the hph‐1 mice compared with the controls. Conclusion: Hph‐1 mice develop a transient smooth muscle hypertrophy of the pylorus attended by gastric distension and failure to gain weight. These changes resolve as the pyloric muscle hypertrophy resolves.
Some Segmental Features on the Structure of the Aortic Wall of the Dog
Authors: Orsi A. M. , Stefanini M. A. , Crocci A. J. , Simões K. , Ribeiro A. A. C. M. 
Published: May 2004

SummaryStructural features of segmental parts of the aorta of the dog were studied by light microscopy (LM) and scanning electron microscopy (SEM). The variability in the wall architecture composition and vascular thickness of the ascending (T2‐3 level), thoracic (T7‐8 level) and abdominal (L6‐7 infrarenal level) segments of the aorta was analysed. Morphological features such as presence of intimal folds, pattern of the medial myoconnective components with segmental variations in the number of elastic lamellae, whose relative number was higher in the thoracic aorta (ascending and descending parts), compared with the abdominal aorta, and a network of connective (stromal) elements formed by elastic and collagen lamellae and fibres in the adventitia were observed. The results were discussed on a histophysiological basis, because small but significant segmental differences had been characterized in the aortic wall structure of the dog.
Immunocytochemical Detection of Synaptophysin in Enteric Neurones during Prenatal Development in the Rat Stomach
Authors: Asar M. , Bayram Z. , Korgun E. T. , Tertemiz F. , Akkoyunlu G. , Demir R. 
Published: May 2004

SummaryIn this study, the localization and appearance of synaptophysin‐immunoreactive (IR) nerve cells and their relationships with the developing gastric layers were studied by immunocytochemistry and light microscopy in the embryonic rat stomach. The stomachs of Wistar rat embryos aged 13–21 days were used. The first neuronal bodies and their processes containing synaptophysin‐immunoreactivity were observed on embryonic day 13. In contrast, synaptophysin‐IR nerve terminals were first observed between mesenchymal cells on embryonic day 14. These results indicate that synaptophysin is expressed in growing neurits and neuronal cell bodies before these neurones have established synaptic connections. The occurrences of mesenchymal cell condensation near synaptophysin‐IR neuroblasts on embryonic day 15 reflect an active nerve element‐specific mesenchymal cell induction resulting in the morphogenesis of muscle cells. Similarly, the appearance of glandular structures after synaptophysin‐IR neuroblasts, on embryonic day 18, suggests that the epithelial differentiation may be closely related to the neuronal maturation as well as other factors. Finally, synaptophysin is functionally important in neuronal development and maturation, together with the establishment of neuroneuronal and neuromuscular contacts and in epithelial differentiation.
Histo‐anatomical Studies on the Accessory Reproductive Glands of the Anatolian Souslik (Spermophilus xanthoprymnus) (Mammalia: Sciuridae)
Authors: Çakir M. , Karataş A. 
Published: May 2004

SummaryIn this study, the histo‐anatomy of the accessory reproductive glands of the Anatolian souslik (Spermophilus xanthoprymnus) is investigated, using 102 males of the vouchers which were captured from central Anatolia and eastern Mediterranean regions. Averages of measurements taken from each part of the accessory reproductive glands were as follows: length of vesicular gland [right: 3.96 (±0.48) mm; left: 3.70 (±0.55) mm]; prostate gland [length: 2.55 (±0.38) mm; width: 2.63 (±0.45) mm]; length of bulbourethral gland [right: 2.32 (±0.33) mm; left: 2.37 (±0.39) mm], and the length of the pars pelvina of the urethra was 12.31 (±0.76) mm. Histological sections showed that vesicular gland was composed of typically branched tubulo‐alveolar glands. As the fibrous connective tissue that was found among alveoles in the prostate was dense and relatively common, only few tubulo‐alveolar glands occurred. The bulbourethral gland (Cowper's gland) was a tubulo‐alveolar gland with a large and serrated lumen and septa between the alveoles consisted of dense fibro‐muscular fibres.
Neurosteroidogenesis in Oligodendrocytes and Purkinje Neurones of Cerebellar Cortex of Dogs
Authors: Yarim M. , Kabakci N. 
Published: May 2004

SummaryThe cerebellum is a steroidogenic organ that expresses steroidogenic enzymes and produces neurosteroids. Purkinje neurones appear to be the most active steroidogenic cells in the cerebellar cortex. These neurones express 3β‐hydroxysteroid dehydrogenase (3β‐HSD), P450 side‐chain cleavage (P450scc), 17α‐hydroxylase/c17, 20lyase (P450c17), P450 aromatase (P450arom) and produce pregnenolone, progesterone, dehydroepiandrosterone, androstenedion, oestradion and oestrone. Oligodendrocytes are predominantly the producer of myeline protein. The oligodendrocytes were identified by immunohistochemistry using a monoclonal antibody against myeline 2′, 3′‐cyclic nucleotide 3′‐phosphodiesterase (CNPase), a myeline specific enzyme. In this study we have examined the distribution of 3β‐HSD and CNPase by immunohistochemistry using monoclonal antibody in canine cerebellar cortex. The localization of oligodendrocytes within the cerebellar cortex was determined to be close to Purkinje neurones. This result suggests that endogenous progesterone synthesized de novo in the Purkinje neurone can promote myeline protein synthesis in oligodentrocytes.
Quantitative Analysis of Cells in the Ganglion Cell Layer of the Chick Retina: Developmental Changes in Cell Density and Cell Size
Authors: Chen Y. , Wang Z. , Shibata H. , Naito J. 
Published: May 2004

SummaryChanges in cell density and size in the ganglion cell layer (GCL) of the retina were studied in chick embryos and post‐hatching chicks. The total number of cells in the GCL increased from 3.64 million at embryonic day 8 (E8) to the maximal 7.85 million at E14. After E14, the number of cells decreased to 6.08 million at post‐hatching day 1 (P1) and 4.87 million at P8. Cell density in the GCL decreased unevenly according to retinal regions; cell density in the presumptive central area (pCA) of P8‐chicks decreased to approximately 45% of that in E8‐embryos. Densities of the nasal peripheral retina (NP) and temporal peripheral retina (TP) of P8‐chicks decreased to 23 and 18% of E8‐embryos, respectively. Differentiation of the central (44 000 cells/mm2 in pCA) – peripheral (28 000 cells/mm2 in TP) gradient in cell density was formed by E8. The presumptive dorsal area (pDA) was shaped by E11, but became obscure with age. Although ganglion cell sizes were basically uniform at E8, differentiation occurred with the appearance of larger ganglion cells after E14. Mean size of retinal ganglion cells increased 2.8‐fold in the pCA and 3.8‐fold in the TP between E8 and P8, accompanying a similar scale of decreases in cell densities.
Stereology of the Liver in Three Species ofLeontopithecus(Lesson, 1840) Callitrichidae – Primates
Authors: Burity C. H. F. , Pissinatti A. , Mandarim‐de‐Lacerda C. A. 
Published: May 2004

SummaryStudies on liver morphology and stereology are relevant to the comparative anatomical and pathological research. They also facilitate the use of non‐human primates in basic research, which has substantially supported studies in human medicine. Quantitative studies of liver structures have also been more extensive in Old World primates and other vertebrates. Twenty‐three livers of adult lion tamarins were studied (sixLeontopithecus rosalia, sevenLeontopithecus chrysomelas, and 10Leontopithecus chrysopygus), dissected, and fixed in 10% neutral buffered formalin solution. For stereological quantification, the liver was regarded as consisting of parenchyma (hepatocytes) and stroma (non‐hepatocytes). The volume density (Vv) was determined by point counting, and the disector method was used to obtain the numerical density of hepatocytes (Nv). Hepatic stereological differences among the three species of lion tamarins were not statistically significant. Therefore, the pooledVv[hepatocyte]andVv[stroma]could be determined as 96.2 and 7.4%, respectively, andNv[hepatocyte]as 500.33 × 106 cm−3. Significantly different, the values found forVv[hepatocyte]andNv[hepatocyte]in lion tamarins were, respectively, 0.09 and 2.8 times greater than those in baboons, and 0.17 and 3.8 times greater than those in man. However, theVv[stroma]was 1.04 times smaller than that in baboons and 1.79 times smaller than that in man.
Influence of Water Deficit on Uptake and Distribution of Nitrogen in Soybeans Monitored by Soil Injected 15N
Authors: Herzog H. , Götz K.‐P. 
Published: May 2004

AbstractA pot experiment was carried out in a climatic chamber to study 15N‐uptake, translocation and recovery in soybeans [Glycine max (L.) Merr.] as affected by a 13 day interval of water deficits (wd) starting at flowering. Ten or 40 mg 15N (500 or 2000 p.p.m. 15N) was injected at 0.4 m depth into the soil 3 days after flowering (3 DAF). A dose of 10 mg 15N, resulted in a translocation of 50 and 80 % to the shoot at 7 and 13 DAF, respectively; thus the uptake of 15N into the plant organs was limited by the low remaining 15N in the soil after 7 DAF. Therefore, only results referring to the 40 mg 15N application are presented here. The daily 15N‐uptake of well‐water (ww) plants during the 10 days of investigations was about c. 2.5 mg 15N, it was significantly higher than under wd at 7 DAF and tended to be higher at 13 DAF. The reduction by wd was also evident by a lower recovery of 15N (55 % instead of 75 %) at 13 DAF. In almost all leaves and pods there was a trend to a lowered translocation (mg 15N per organ) under wd when compared with the ww plants at 7 and 13 DAF; lowering due to wd was strongest and significant in upper leaves and pods at 13 DAF, whereas translocation to stems was even slightly increased. Relative accumulation of 15N (mg g−1 dry matter) in leaves, stems and pods increased from the bottom to the top indicating an higher sink activity of younger organs. Water deficits tended to lower this relative 15N‐accumulation in all leaves and pods at 7 and 13 DAF, and caused a significant reduction in upper leaves and pods at 7 DAF. Absolute and relative 15N‐accumulation in stems tended to be affected differently by wd, being unaffected or slightly decreased at 7 DAF, but increased at 13 DAF. These differential effects of wd are discussed.
Influence of Seeding Depth and Seedbed Preparation on Establishment, Growth and Yield of Fibre Flax (Linum usitatissimum L.) in Eastern Canada
Authors: Couture S. J. , DiTommaso A. , Asbil W. L. , Watson A. K. 
Published: May 2004

AbstractResearch was conducted at the Macdonald Campus of McGill University (Québec, Canada) at three sites in 1997 and one site in 1998 to determine the effects and interactions of seeding depth (0, 1, 2, 4 or 6 cm) and seedbed preparation (i.e. soil rolling): none, rolling before or rolling after seeding on fibre flax (cv. Ariane) establishment, growth and yield. Seedbed preparation had little impact on the parameters measured while seeding depth had a variable effect on plant density, plant height, stem diameter and retted straw yield. Seeding depths of 1–4 cm provided consistently good establishment, growth and yield results. In 1997, there was an interaction between seeding depth and seedbed preparation on plant height, branching ratio and retted straw yield, although results were generally variable and tended to be site‐specific. In 1998, there was an interaction between seeding depth and seedbed preparation on plant height and stem diameter prior to harvest, with the results varying for all seeding depth‐seedbed preparation treatment combinations except for the 2‐cm depth treatment. Rolling of the seedbed before seeding on lighter soils and at a depth of 2 cm on most soils can improve establishment, growth and yields of fibre flax under eastern Canadian growing conditions.
Diet and bone health
Authors: Phillips Frankie 
Published: May 2004

SummaryThe aim of this report is to bring together, in a user‐friendly format, the progress and results of recent European Union funded projects that have investigated some of the nutritional aspects of bone health. This report provides an overview of some of the reasons why nutrition is important for healthy bones and focuses on the prevention of osteoporosis. As an introduction, some background information on bone physiology, and the nutrients which are needed for healthy bones, is provided.
Primetime television impacts on adolescents’ impressions of bodyweight, sex appeal, and food and beverage consumption
Authors: Hampl Jeffrey S. , Wharton Chris M. , Taylor Christopher A. , Winham Donna M. , Block Jillian L. , Hall Rick 
Published: May 2004

SummaryTelevision viewing is ubiquitous in adolescent culture, but the influence of television characters on adolescent behaviours and social norms is not well understood. We conducted a content analysis of 10 television programmes frequently watched by 12‐ to 17‐year‐olds in the US media market. From these data, a survey was developed to determine how adolescents interact with, and are influenced by, television programmes, especially in relation to bodyweight, sex appeal, and food and beverage consumption. The survey was posted online, and students (12–19 years) from across the state of Arizona, USA, completed it electronically (n = 524). Data were assessed by tabulation, principal axis factor analysis and linear regression analysis. The results showed 12% of sample members had a body mass index (BMI)‐for‐age over the 95th percentile, 50% reported watching >2 h of television each day, and 59% reported accruing < 60 min of exercise and physical activity each day. Over 35% of respondents indicated eating pizza and pasta frequently. Beer and wine were seen as the most frequently consumed beverages on television, while 63.9% of sample members reported soda as their personal beverage of choice. Factor extraction from the survey indicated a three‐factor solution (‘sex appeal’, ‘TV viewers and perceivers’, ‘TV viewers and doers’) provided the best conceptual explanation of the data, accounting for 34.7% of the total variance. Significant predictors (r2 = 0.448) of BMI‐for‐age included urbanicity (β = 5.6), gender (β = −14.5) and survey questions related to bodyweight perceptions. Our data showed that television's focus on sex appeal, thinness and alcohol may have a powerful impact on adolescents’ self‐esteem, body satisfaction and health behaviours. Innovative approaches related to decreased television viewing, household eating environment and media literacy warrant further exploration.
Intentional action and nearly certain success
Authors: Gert Joshua 
Published: May 2004

AbstractMany philosophers have argued that a necessary condition on an action's being intentional is that the agent has the ability to alter the probabilities of the relevant outcome. These philosophers would hold that this condition is what allows us to deny that an agent, for example, intentionally rolls something other than five fives with a set of dice, despite that agent's being virtually sure that this will be the outcome of the roll. The current paper uses some examples to cast this explanation, and the necessity of the associated condition, into doubt. It then suggests that what actually differentiates intentional from unintentional action – in the examples that falsify the hypothesis about control – is to be found in the agent's representation of the processes by which the relevant outcomes are produced. In particular, the agent must represent the outcome as happening because of what she does.
Horwich on meaning and use
Authors: Katzav Joel 
Published: May 2004

AbstractPaul Horwich claims that theories of meaning ought to accommodate the commonsense intuition that meanings play a part in explaining the use of words. Further, he argues that the view that best does so is that according to which the meaning of a word is constituted by a disposition to accept, in some circumstances, sentences in which it features. I argue that if meanings are construed thus, they will in fact fail to explain the use of words. I also argue that if we insist, as Horwich does, on the commonsense assumption that meanings are a species of entity, all versions of the view that meaning is constituted by our dispositions to use words will have to be rejected. I do not, however, claim that such theories ought to be rejected. My point is that they are incompatible with the requirements of commonsense. Further, I suggest that it is premature to impose such requirements on theories of meaning.