bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo leptin expression in cartilage and bone cells of growing rats and adult humans
Authors: Morroni M. , De Matteis R. , Palumbo C. , Ferretti M. , Villa I. , Rubinacci A. , Cinti S. , Marotti G. 
Published: October 2004

AbstractThe present investigation was carried out to analyse, immunohistochemically, in vivo leptin expression in cartilage and bone cells, the latter restricted to the elements of the osteogenic system (stromal cells, osteoblasts, osteocytes, bone lining cells). Observations were performed on the first lumbar vertebra, tibia and femur of four rats and on the humerus, femur and acromion of four patients. Histological sections of paraffin‐embedded bone samples were immunostained using antibody to leptin. The results showed that, in growing rat bone, leptin is expressed in chondrocytes and stromal cells, but not in osteoblasts; bone lining cells were not found in the microscopic fields examined. In adult human bone, leptin is expressed in chondrocytes, stromal cells and bone lining cells; osteoblasts were not found in the microscopic fields examined. Osteocytes were found to be leptin positive only occasionally and focally in both rat and human bone. The in vivo findings reported show, for the first time, that leptin appears to be expressed only in the cells of the osteogenic lineage (stromal cells, bone lining cells, osteocytes) that, with respect to osteoblasts, are permanent and inactive, i.e. in those cells that according to our terminology constitute the bone basic cellular system (BBCS). Because the BBCS seems to be primarily involved in sensing and integrating mechanical strains and biochemical factors and then in triggering and driving bone formation and/or bone resorption, it appears that leptin seems to be mainly involved in modulating the initial phases of bone modelling and remodelling processes.
Interobserver error involved in independent attempts to measure cusp base areas of Pan M1s
Authors: Bailey Shara E. , Pilbrow Varsha C. , Wood Bernard A. 
Published: October 2004

AbstractCusp base areas measured from digitized images increase the amount of detailed quantitative information one can collect from post‐canine crown morphology. Although this method is gaining wide usage for taxonomic analyses of extant and extinct hominoids, the techniques for digitizing images and taking measurements differ between researchers. The aim of this study was to investigate interobserver error in order to help assess the reliability of cusp base area measurement within extant and extinct hominoid taxa. Two of the authors measured individual cusp base areas and total cusp base area of 23 maxillary first molars (M1) of Pan. From these, relative cusp base areas were calculated. No statistically significant interobserver differences were found for either absolute or relative cusp base areas. On average the hypocone and paracone showed the least interobserver error (< 1%) whereas the protocone and metacone showed the most (2.6–4.5%). We suggest that the larger measurement error in the metacone/protocone is due primarily to either weakly defined fissure patterns and/or the presence of accessory occlusal features. Overall, levels of interobserver error are similar to those found for intraobserver error. The results of our study suggest that if certain prescribed standards are employed then cusp and crown base areas measured by different individuals can be pooled into a single database.
A mesenchyme‐free culture system to elucidate the mechanism of otic vesicle morphogenesis
Authors: Miura Takashi , Shiota Kohei , Morriss‐Kay Gillian 
Published: October 2004

AbstractThe vertebrate inner ear has been extensively studied as a model system of morphogenesis and differentiation. The interactions between epithelium and surrounding mesenchyme have not previously been studied directly, because an appropriate experimental system had not been established. Here we describe a mesenchyme‐free culture system of E11.5 mouse otic vesicle which retains the ability for (1) formation of the cochlear loop, (2) emigration of ganglion cells from the epithelium and (3) invagination of semicircular canal epithelium. E10.5 otic vesicle was maintained using the same method, but morphogenesis was less successful. Culture of the E11.5 cochlear region alone resulted in regeneration of a structure with semicircular canal character from the cut end, indicating that region‐specific cell fate within the otic vesicle is not irreversibly determined at this stage. Co‐culturing otic vesicle with cochleovestibular ganglion (CVG) resulted in enhanced looping or ectopic diverticulum formation of the cochlear region, suggesting that the CVG provides a morphogenetic signal for cochlear looping. Cochlear looping was specifically blocked by inhibiting actin polymerization by cytochalasin D, while morphogenesis of the semicircular canal region remained intact. Hyaluronidase treatment inhibited semicircular canal morphogenesis, resulting in a cystic form of the otic vesicle. These data validate this culture system as a tool for elucidating the mechanism of morphogenesis of the otic vesicle.
Cytochemical and ultrastructural characterization of growing colonies of human embryonic stem cells
Authors: Johkura Kohei , Cui Li , Asanuma Kazuhiko , Okouchi Yasumitsu , Ogiwara Naoko , Sasaki Katsunori 
Published: October 2004

AbstractThe morphology of human embryonic stem (ES) cells changes with their colonial growth. For a better understanding of the growth of ES cell colonies in culture, we determined their cytochemical and ultrastructural characteristics focusing on images of living cells under a phase contrast microscope. During the initial growth stages, the colonies exhibited a mosaic appearance with discernible cell–cell borders. PAS staining coupled with amylase digestion demonstrated that the bright granules and dark deposits in the cytoplasm contained glycogen. Ultrastructurally they were glycogen accumulations, and clustered open spaces associated with various amounts of glycogen. Although intercellularly heterogeneous, these structures were detectable throughout colony growth. As the colonies grew, compaction towards the centre emerged and increased, accompanied by heterogeneous increases in coarse particles with or without a halo. TUNEL showed these particles to consist at least in part of apoptotic cells/bodies. Transmission electron microscopy indicated that most apoptotic cells had been phagocytosed by intact ES cells. Spontaneous differentiation was detected occasionally in the periphery of the colonies. The presence of PAS‐positive fibrous structures not susceptible to amylase digestion and laminin‐immunoreactivity indicated the accumulation of extracellular matrix in the peripheral differentiated areas. These findings made it possible to determine the growth stage of human ES cell colonies.
No change in neuron numbers in the dentate nucleus of patients with schizophrenia estimated with a new stereological method – the smooth fractionator
Authors: Andersen B. B. , Fabricius K. , Gundersen H. J. G. , Jelsing J. , Stark A. K. 
Published: October 2004

AbstractThe dentate nucleus is phylogenetically the most recent nucleus in the cerebellum. Owing to its connections to the thalamus and the prefrontal cortex it may be involved in the symptomathology in schizophrenia and other psychiatric illnesses. In this stereological study we implemented the smooth fractionator, which combines the unbiased principles of the optical fractionator with a new and more efficient sampling strategy to the dentate nucleus. The smooth fractionator represents the most efficient sampling strategy described so far in stereology, in terms of reducing the sampling variance and thus increasing the efficiency. It is the first application of the smooth fractionator to human brain tissue and presents estimations of total number of neurons in the dentate nuclei of eight patients with schizophrenia compared to eight control persons. The total number of neurons in the dentate nucleus was estimated to 3.36 × 106in subjects with schizophrenia, which was not statistically significant different from 3.65 × 106in control subjects (P = 0.63). The advantages and disadvantages of the smooth fractionator method are discussed and its precision in practical application is estimated.
A stereological evaluation of secretin and gastric inhibitory peptide‐containing mucosal cells of the perinatal small intestine of the pig
Authors: Van Ginneken C. , Weyns A. 
Published: October 2004

AbstractStereological methods were used to quantify secretin and gastric inhibitory peptide (GIP)‐immunoreactivity (GIP‐IR) in paraffin sections of the duodenum, jejunum and ileum of fetal and neonatal piglets. In addition, sections were processed for GLP‐1‐immunohistochemistry. The volume density of the tunica mucosa increased after birth, giving rise to a decreased volume density of the tela submucosa and tunica muscularis. Generally known region‐specific morphological distinctions were reflected in differing volume densities of the various layers. The highest volume density of GIP‐IR epithelial cells was observed in the jejunum of the neonate. In contrast, the volume density of secretin‐IR epithelial cells was highest in the duodenum of both fetal and neonatal piglets. The volume occupied by GIP‐IR and secretin‐IR epithelial cells increased in the jejunum after birth. Additionally, ileal secretin‐IR epithelial cells were more numerous in the neonatal piglet. In conclusion, the quantitative and qualitative presence of GIP‐IR and secretin‐IR epithelial cells agree with earlier reports of their presence and co‐localization between GIP‐IR and GLP‐1‐IR, in the pig small intestine.Furthermore, the differences suggest that age‐ and region‐related functional demands are temporally and probably causally related with the morphological diversification of the intestine and its endocrine cells.
Characterization of multiple transcripts and isoforms derived from the mouse protein tyrosine phosphatase gene Ptprr
Authors: Chirivi Renato G. S. , Dilaver Gönül , van de Vorstenbosch Rinske , Wanschers Bas , Schepens Jan , Croes Huib , Fransen Jack , Hendriks Wiljan 
Published: October 2004

The use of alternative splice sites, promoters and translation start sites considerably adds to the complexity of organisms. Four mouse cDNAs (PTPBR7, PTP‐SL, PTPPBSγ+ and PTPPBSγ−) have been cloned that contain different 5′ parts but encode identical protein tyrosine phosphatase PTPRR catalytic domains. We investigated the genomic origin and coding potential of these transcripts to elucidate their interrelationship. Mouse gene Ptprr exons were identified within a 260 kbp segment on chromosome 10, revealing PTP‐SL‐ and PTPPBSγ‐specific transcription start sites within introns two and four, respectively, relative to the 14 PTPBR7 exons. Northern and RT‐PCR analyses demonstrated differential expression patterns for these promoters. Furthermore, transfection studies and AUG codon mutagenesis demonstrated that in PTP‐SL and PTPPBSγ messengers multiple translation initiation sites are being used. Resulting 72, 60, 42 and 37 kDa PTPRR protein isoforms differ not only in the length of their N‐terminal part but also in their subcellular localization, covering all major PTP subtypes; receptor‐like, membrane associated and cytosolic. In summary, mouse gene Ptprr gives rise to multiple isoforms through the use of distinct promoters, alternative splicing and differential translation starts. These results set the stage for further investigations on the physiological roles of PTPRR proteins.
DNA topoisomerase II is required for the G0‐to‐S phase transition in Drosophila Schneider cells, but not in yeast
Authors: Hossain Muktadir S. , Kurokawa Kenji , Akimitsu Nobuyoshi , Sekimizu Kazuhisa 
Published: October 2004

We previously reported that DNA topoisomerase II (topo II) is required for the G0‐to‐S phase transition in mammalian cells [Hossain et al. (2002) ICRF‐193, a catalytic inhibitor of DNA topoisomerase II, inhibits re‐entry into the cell division cycle from quiescent state in mammalian cells. Genes Cells 7, 285–294]. In this study, we examined whether the requirement for topo II is evolutionarily conserved in Drosophila and yeast. ICRF‐193, a catalytic inhibitor of topo II, inhibited DNA synthesis in Drosophila Schneider cells released from the G0 (stationary) phase, whereas the drug did not inhibit DNA synthesis in Schneider cells released from the M phase. Depletion of topo II mRNA by RNA‐interference (RNAi) in G0‐phase Schneider cells resulted in significant inhibition of DNA synthesis after release from G0‐arrest. In the yeast topo II temperature‐sensitive (ts) mutant, the initial cycle of DNA synthesis occurred at a restrictive temperature after release from starvation‐induced G0 phase and doubling of the DNA content in the cells was confirmed by both flow cytometry and fluorescence spectrophotometry. DNA synthesis in yeast cells after release from the G0 phase was also observed in the presence of ICRF‐193. Doubling of the DNA content was observed during spore germination of topo II ts mutant yeast at a restrictive temperature as determined by fluorescence spectrophotometry. These results indicate that topo II is required for the G0‐to‐S phase transition in Drosophila Schneider cells, but not in yeast.
Cognitive reorganization and stigmatization among persons with HIV
Authors: Abel Elizabeth , Rew Lynn , Gortner Eva‐Maria , Delville Carol L. 
Published: October 2004

Background.  A diagnosis of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is a life‐changing event, where persons must deal with a life‐threatening, debilitating disease and its associated stigma and isolation. Studies over the past decade have shown that writing and talking about stressful and traumatic experiences, such as a life‐threatening illness, causes emotions surrounding the trauma to change and to become cognitively reorganized. The result is a reduction in inhibition and change in basic cognitive and linguistic processes, which have contributed to meaningful behavioural, psychological, and physical health benefits across a variety of populations.Aims.  To describe the construction of the Integrated Model of Health Promotion for persons with HIV/AIDS, and present initial empirical support of the model from a feasibility pilot study of women with HIV/AIDS.Approach.  The Integrated Model of Health Promotion is described and relevant literature in the field is reviewed. The model is implemented in a feasibility pilot study utilizing the emotional writing disclosure intervention.Results.  Participants in the experimental condition demonstrated a promising pattern of cognitive reorganization, a reduced perception of stigma, and an improvement in mental health scores compared with the control condition.Conclusion.  Implications of these findings are discussed within the framework of the Integrated Model of Health Promotion. The model explores health and behavioural benefits associated with emotional writing in individuals with HIV/AIDS. The limited sample size of this pilot study precludes testing for significance. Further studies are required prior to the development of practice guidelines.
Deletion of the genes encoding the MtrA–MtrB two‐component system of Corynebacterium glutamicum has a strong influence on cell morphology, antibiotics susceptibility and expression of genes involved in osmoprotection
Authors: Möker Nina , Brocker Melanie , Schaffer Steffen , Krämer Reinhard , Morbach Susanne , Bott Michael 
Published: October 2004

SummaryThe MtrAB two‐component signal transduction system is highly conserved in sequence and genomic organization in Mycobacterium and Corynebacterium species, but its function is completely unknown. Here, the role of MtrAB was studied with C. glutamicum as model organism. In contrast to M. tuberculosis, it was possible to delete the mtrAB genes in C. glutamicum. The mutant cells showed a radically different cell morphology and were more sensitive to penicillin, vancomycin and lysozyme but more resistant to ethambutol. In order to identify the molecular basis for this pleiotropic phenotype, the mRNA profiles of mutant and wild type were compared with DNA microarrays. Three genes showed a more than threefold increased RNA level in the mutant, i.e. mepA (NCgl2411) encoding a putative secreted metalloprotease, ppmA (NCgl2737 ) encoding a putative membrane‐bound protease modulator, and lpqB encoding a putative lipoprotein of unknown function. Expression  of  plasmid‐encoded  mepA in  Escherichia  coli led to elongated cells that were hypersensitive to an osmotic downshift, supporting the idea that peptidoglycan is the target of MepA. The mRNA level of two genes was more than fivefold decreased in the mutant, i.e. betP and proP which encode transporters for the uptake of betaine and proline respectively. The microarray results were confirmed by primer extension and RNA dot blot experiments. In the latter, the transcript level of genes involved in osmoprotection was tested before and after an osmotic upshift. The mRNA level of betP, proP and lcoP was strongly reduced or undetectable in the mutant, whereas that of mscL (mechanosensitive channel) was increased. The changes in cell morphology, antibiotics susceptibility and the mRNA levels of betP, proP, lcoP, mscL and mepA could be reversed by expression of plasmid‐encoded copies of mtrAB in the ΔmtrAB mutant, confirming that these changes occurred as a consequence of the mtrAB deletion.
HopPtoN is a Pseudomonas syringae Hrp (type III secretion system) cysteine protease effector that suppresses pathogen‐induced necrosis associated with both compatible and incompatible plant interactions
Authors: López‐Solanilla Emilia , Bronstein Philip A. , Schneider Anna R. , Collmer Alan 
Published: October 2004

Summary Pseudomonas syringae pv. tomato DC3000 causes bacterial speck disease in tomato, and it elicits the hypersensitive response (HR) in non‐host plants such as Nicotiana tabacum and Nicotiana benthamiana. The compatible and incompatible interactions of DC3000 with tomato and Nicotiana spp., respectively, result in plant cell death, but the HR cell death occurs more rapidly and is associated with effective plant defense. Both interactions require the Hrp (HR and pathogenicity) type III secretion system (TTSS), which injects Hop (Hrp outer protein) effectors into plant cells. Here, we demonstrate that HopPtoN is translocated into tomato cells via the Hrp TTSS. A hopPtoN mutant produced eightfold more necrotic ‘speck’ lesions on tomato leaves than did DC3000, but the mutant and the wild‐type strain grew to the same level in infected leaves. In non‐host N. tabacum leaves, the hopPtoN mutant produced more cell death, whereas a DC3000 strain overexpressing HopPtoN produced less cell death and associated electrolyte leakage in comparison with wild‐type DC3000. Transient expression of HopPtoN via infection with a PVX viral vector enabled tomato and N. benthamiana plants to tolerate, with reduced disease lesions, challenge infections with DC3000 and P. syringae pv. tabaci 11528, respectively. HopPtoN showed cysteine protease activity in vitro, and hopPtoN mutants altered in the predicted cysteine protease catalytic triad (C172S, H283A and D299A) lost HR suppression activity. These observations reveal that HopPtoN is a TTSS effector that can suppress plant cell death events in both compatible and incompatible interactions.
Extension of a biochemical model for the generalized stoichiometry of electron transport limited C3 photosynthesis
Authors: YIN X. , VAN OIJEN M. , SCHAPENDONK A. H. C. M. 
Published: October 2004

ABSTRACTThe widely used steady‐state model of Farquhar et al. (Planta 149: 78–90, 1980) for C3 photosynthesis was developed on the basis of linear whole‐chain (non‐cyclic) electron transport. In this model, calculation of the RuBP‐regeneration limited CO2‐assimilation rate depends on whether it is insufficient ATP or NADPH that causes electron transport limitation. A new, generalized equation that allows co‐limitation of NADPH and ATP on electron transport is presented herein. The model is based on the assumption that other thylakoid pathways (the Q‐cycle, cyclic photophosphorylation, and pseudocyclic electron transport) interplay with the linear chain to co‐contribute to a balanced production of NADPH and ATP as required by stromal metabolism. The original model assuming linear electron transport limited either by NADPH or by ATP, predicts quantum yields for CO2 uptake that represent the highest and the lowest values, respectively, of the range given by the new equation. The applicability of the new equation is illustrated for a number of C3 crop species, by curve fitting to gas exchange data in the literature. In comparison with the original model, the new model enables analysis of photosynthetic regulation via the electron transport pathways in response to environmental stresses.
Phytochrome modulation of blue‐light‐induced phototropism
Authors: WHIPPO C. W. , HANGARTER R. P. 
Published: October 2004

ABSTRACTRed light enhances hypocotyl phototropism toward unilateral blue light through a phytochrome‐mediated response. This study demonstrates how the phytochromes modulate blue‐light‐induced phototropism in the absence of a red light pre‐treatment. It was found that phytochromes A, B, and D have conditionally overlapping functions in the promotion of blue‐light‐induced phototropism. Under very low blue light intensities (0.01 µmol m−2 s−1) phyA activity is necessary for the progression of a normal phototropic response, whereas above 1.0 µmol m−1 s−2 phyB and phyD have functional redundancy with phyA to promote phototropism. PhyA also contributes to attenuation of phototropism under high fluence rates of unilateral blue light, which was previously shown to be dependent on the phototropins and cryptochromes. From these results, it appears that phytochromes are required to develop a robust phototropic response under low fluence rates, whereas under high irradiances where phototropism may be less important, phyA suppresses phototropism.
IgE binding to pepsin‐digested water soluble and insoluble wheat proteins
Authors: Mesa‐del‐Castillo M. , Martínez‐Cócera C. , Caballero M. L. , Vazquez L. , Moneo I. 
Published: October 2004

Background:  Positive skin prick tests to wheat are a common finding among atopic patients, but only a minor fraction of these patients show immediate clinical symptoms after wheat ingestion. The aim of this study was to evaluate the allergenicity of wheat proteins after pepsin treatments.Methods:  Six patients with positive specific IgE and/or skin prick test to soluble wheat proteins and to gluten were studied. Five of them had no symptoms after wheat ingestion and showed a negative oral challenge test. All sera were analysed with extracts obtained after pepsin hydrolysis during different time periods of water‐soluble and insoluble wheat proteins by IgE immunoblotting.Results:  A pepsin‐sensitive allergen of around 35 kDa was recognized by the five atopic negative wheat oral challenge patients in the undigested water‐insoluble extract. A patient showing immediate urticaria after wheat ingestion detected a pepsin‐resistant allergen with similar molecular weight. Finally, an inhalation‐induced asthma patient recognized water‐soluble proteins (of around 14 kDa) that could correspond to the α‐amylase inhibitors.Conclusions:  Our immunoblotting method shows better correlation with the clinical symptoms than skin prick test and CAP results. Pepsin resistance of the acetic acid‐soluble wheat proteins may be responsible for the immediate symptoms of the patient who presented immediate urticaria.