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Cell Number (cell + number)
Kinds of Cell Number Selected AbstractsStudies on Cell Number and Nuclei in Spores and on Ploidy Level in Ascochyta rabiei IsolatesJOURNAL OF PHYTOPATHOLOGY, Issue 5 2001Bruns Isolates of the phytopathogenic ascomycete Ascochyta rabiei (Pass.) Labr. were stained with the DNA-specific fluorochrome 4,,6-diamidino-2-phenylindole (DAPI) and compared for differences in number of nuclei per pycnidiospore and the ploidy level. Microscopic analyses revealed that within the examined isolates five different combinations of cell number and number of nuclei in spores exist. A one-celled spore may contain one, two and four nuclei, respectively, and in the case of two-celled spores there exist types with one and two nuclei in one cell. Microfluorometric analyses of wild types and benomyl-treated isolates revealed differences in ploidy level among the wild types. [source] Control of Cell Number in the Bed Nucleus of the Stria Terminalis of Mice: Role of Testosterone Metabolites and Estrogen Receptor SubtypesTHE JOURNAL OF SEXUAL MEDICINE, Issue 4pt1 2010Shin-ichi Hisasue MD ABSTRACT Introduction., The bed nucleus of the stria terminalis (BNST) exhibits several sex differences that may be related to male sexual behavior and gender identity. In mice and rats, sex differences in the principal nucleus of the BNST (BNSTp) are due to sexually dimorphic cell death during perinatal life. Although testosterone treatment of newborn female rats increases BNSTp cell number, the relevant hormone metabolite(s) are not known, and the effect of testosterone on the development of BNSTp cell number in mice has not been examined. Aim., To identify the sex hormone metabolites and receptors controlling cell number, volume, and cell size in the BNSTp of mice. Methods., In the first experiment, C57BL/6J male mice were injected on the day of birth with peanut oil; females were injected with testosterone propionate (TP), estradiol benzoate (EB), dihydrotestosterone propionate (DHTP), or oil alone, and the BNSTp of all animals was examined in adulthood. In the second experiment, to compare effects of EB to the effects of estrogen receptor subtype specific agonists, newborn female mice were injected with EB, propyl-pyrazole-triol (PPT, a selective estrogen receptor alpha [ER,] agonist), or diarylpropionitrile (DPN, a selective estrogen receptor beta [ER,] agonist). Main Outcome Measures., Nuclear volume measurements and stereological cell counts in the BNSTp in adulthood. Results., TP treatment of newborn females completely masculinized both BNSTp volume and cell number. EB masculinized neuron number, whereas DHTP had no effect on volume or cell number. In the second experiment, EB again fully masculinized neuron number in the BNSTp and in this study also masculinized BNSTp volume. PPT and DPN each significantly increased cell number, but neither completely mimicked the effects of EB. Conclusions., We conclude that estrogenic metabolites of testosterone control sexually dimorphic cell survival in the BNSTp and that activation of both ER, and ER, may be required for complete masculinization of this brain region. Hisasue S, Seney ML, Immerman E, and Forger NG. Control of cell number in the bed nucleus of the stria terminalis of mice: Role of testosterone metabolites and estrogen receptor subtypes. J Sex Med 2010;7:1401,1409. [source] Chronic Ethanol Consumption Decreases Murine Langerhans Cell Numbers and Delays Migration of Langerhans Cells as Well as Dermal Dendritic CellsALCOHOLISM, Issue 4 2008Kristin J. Ness Background:, Chronic alcoholics experience increased incidence and severity of infections, the mechanism of which is incompletely understood. Dendritic cells (DC) migrate from peripheral locations to lymph nodes (LN) to initiate adaptive immunity against infection. Little is known about how chronic alcohol exposure affects skin DC numbers or migration. Methods:, Mice received 20% EtOH in the drinking water for up to 35 weeks. Baseline Langerhans cell (LC) and dermal DC (dDC) numbers were enumerated by immunofluorescence (IF). LC repopulation after inflammation was determined following congenic bone marrow (BM) transplant and ultraviolet (UV) irradiation. Net LC loss from epidermis was determined by IF following TNF-, or CpG stimulation. LC and dDC migration into LN was assessed by flow cytometry following epicutaneous FITC administration. Results:, Chronic EtOH consumption caused a baseline reduction in LC but not dDC numbers. The deficit was not corrected following transplantation with non-EtOH-exposed BM and UV irradiation, supporting the hypothesis that the defect is intrinsic to the skin environment rather than LC precursors. Net loss of LC from epidermis following inflammation was greatly reduced in EtOH-fed mice versus controls. Ethanol consumption for at least 4 weeks led to delayed LC migration into LN, and consumption for at least 8 weeks led to delayed dDC migration into LN following epicutaneous FITC application. Conclusions:, Chronic EtOH consumption causes decreased density of epidermal LC, which likely results in decreased epidermal immunosurveillance. It also results in altered migratory responsiveness and delayed LC and dDC migration into LN, which likely delays activation of adaptive immunity. Decreased LC density at baseline appears to be the result of an alteration in the skin environment rather than an intrinsic LC defect. These findings provide novel mechanisms to at least partially explain why chronic alcoholics are more susceptible to infections, especially those following skin penetration. [source] Chronic ethanol intake inhibits in vitro osteogenesis induced by osteoblasts differentiated from stem cellsJOURNAL OF APPLIED TOXICOLOGY, Issue 2 2008Maria L. Rosa Abstract The study investigated whether chronic ethanol (ETH) intake and subsequent ETH exposure of cell cultures affects osteoblast differentiation by evaluating key parameters of in vitro osteogenesis. Rats were treated with 5,20% (0.85,3.43 mm) ETH, increasing by 5% per week for a period of 4 weeks (habituation), after which the 20% level was maintained for 15 days (chronic intake). Bone-marrow stem cells from control (CONT) or ETH-treated rats were cultured in osteogenic medium which was either supplemented (ETH) or not supplemented (CONT) with 1.3 mm ethanol. Thus, four groups relating to rat treatment/culture supplementation were evaluated: (1) CONT/CONT, (2) ETH/CONT, (3) CONT/ETH and (4) ETH/ETH. Cell morphology, proliferation and viability, total protein content, alkaline phosphatase (ALP) activity and bone-like nodule formation were evaluated. Chronic ethanol intake significantly reduced both food and liquid consumption and body weight gain. No difference was seen in cell morphology among treatments. Cell number was affected at 7 and 10 days as follows: CONT/CONT = CONT/ETH < ETH/CONT = ETH/ETH. Doubling time between 3 and 10 days was greater in groups of CONT animals: ETH/ETH = ETH/CONT < CONT/ETH = CONT/CONT. Cell viability and ALP activity were not affected by either animal treatment or culture exposure to ethanol. At day 21, the total protein content was affected as follows: ETH/ETH = CONT/ETH < ETH/CONT = CONT/CONT. Bone-like nodule formation was affected as follows: ETH/ETH < CONT/ETH < ETH/CONT < CONT/CONT. These results show that chronic ethanol intake, followed by the exposure of osteoblasts to ethanol, inhibited the differentiation of osteoblasts, as indicated by an increased proliferation rate and reduced bone-like nodule formation. Copyright © 2007 John Wiley & Sons, Ltd. [source] Control of human articular chondrocyte differentiation by reduced oxygen tensionJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2004Christopher L. Murphy Cell number is often a limiting factor in studies of chondrocyte physiology, particularly for human investigations. Chondrocytes can be readily proliferated in monolayer culture, however, differentiated phenotype is soon lost. We therefore endeavored to restore normal phenotype to human chondrocytes after serial passage in monolayer culture by manipulating cell morphology and oxygen tension towards the in vivo state. Third passage cells were encapsulated in alginate and exposed to either 20% or more physiologic 5% oxygen tensions. To assess cell phenotype, gene expression was measured using TaqMan real-time PCR. Encapsulated, primary chondrocytes cultured in 20% oxygen were used as a positive reference. Passaged human chondrocytes were fibroblastic in appearance and had lost normal phenotype as evidenced by a decrease in expression of collagen II, aggrecan, and sox9 genes of 66, 6, and 14 fold, respectively; with concomitant high expression of type I collagen (22 fold increase). A partial regaining of the differentiated phenotype was observed by encapsulation in 20% oxygen; however, even after 4 weeks, collagen II gene expression was not fully restored. Collagen II and aggrecan expression were increased, on average, 3 fold, in 5% oxygen tension compared to 20% cultures. Furthermore, matrix glycosaminoglycan (GAG) levels were significantly increased in reduced oxygen. In fact, after 4 weeks in 5% oxygen, encapsulated third passage cells had collagen II expression fully regained and aggrecan and sox9 levels actually exceeding primary cell levels in 20% oxygen. Our results show that the phenotype of serially passaged human articular chondrocytes is more fully restored by combining encapsulation with culture in more physiological levels of oxygen. Sox9, an essential transcription factor for chondrocyte differentiation is strongly implicated in this process since its expression was upregulated almost 27 fold. These findings have implications for the optimal conditions for the in vitro culture of chondrocytes. © 2004 Wiley-Liss, Inc. [source] Retinal Endothelial Angiogenic Activity: Effects of Hypoxia and Glial (Müller) CellsMICROCIRCULATION, Issue 7 2004YOUSEF YAFAI ABSTRACT Objective: To explore the impact of retinal glial (Müller) cells on survival and neovascularization-related activities of cultured retinal endothelial cells under normoxic and hypoxic conditions. Methods: Bovine retinal endothelial cells (BRECs) were cultured under normoxia or hypoxia (0.5% O2) either alone, together with the human Müller cell line MIO-M1, or in normoxia- or hypoxia-conditioned media of MIO-M1 cells. Cell number, proliferation, apoptotic cell death, and migration of BRECs were determined. Results: Exposure of BRECs to hypoxia for 24 h decreased the number of adherent cells and the proliferation rate, but increased apoptosis and cell migration. Increased apoptosis and decreased proliferation of the BRECs occurred also in the presence of conditioned media of MIO-M1 cells. Under normoxic conditions, co-culture with MIO-M1 cells resulted in increased proliferation, but decreased apoptosis and migration rates of BRECs. Under hypoxic conditions, the Müller cells released elevated amounts of VEGF but their presence decreased proliferation, apoptosis and the migration rates of BRECs. Conclusions: Hypoxia inhibits the proliferation of retinal endothelial cells. Müller cells release soluble mediators that enhance this hypoxia-mediated effect but, under certain conditions (i.e., in co-culture), may protect retinal endothelial cells from apoptosis, thus supporting their survival. Altogether the findings indicate that the key signal necessary to trigger retinal endothelial proliferation under hypoxia remains to be determined. [source] Oestrogen deficiency causes DNA damage in uterine leiomyoma cells: a possible mechanism for shrinkage of fibroids by GnRH agonistsBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 1 2001Ya-Min Cheng Objective To examine whether gonadotrophin-releasing hormone agonist or oestradiol can directly affect DNA in leiomyoma cells. Design In vitro explant culture of leiomyoma cells. Setting University research group. Sample Leiomyoma cells were cultured from the specimens of four premenopausal women at myomectomy. Methods The presence of gonadotrophin-releasing hormone receptor in leiomyoma cells was determined by reverse transcriptase,olymerase chain reaction. Leiomyoma cells were treated with gonadotrophin-releasing hormone agonist or cultured in different concentrations of oestrogen, progesterone or fetal calf serum for one, four or seven days. Main outcome measures Cell number, expression of proliferating cell nuclear antigen, and DNA damage after one, four or seven days of treatment. Results Gonadotrophin-releasing hormone receptor messenger ribonucleic acid was detected on cultured leiomyoma cells. Leiomyoma cell growth was not affected by the addition of gonadotrophin-releasing hormone agonist or progesterone, but increased with oestrogen or fetal calf serum supplementation. Overexpression of proliferating cell nuclear antigen was prevented in cultures added with oestrogen or fetal calf serum, but not related to gonadotrophin-releasing hormone agonist treatment. Significant decreases in DNA damage as indicated by decreased comet number were found in the leiomyoma cultures treated with oestrogen or fetal calf serum for four and seven days but not with gonadotrophin-releasing hormone agonist or progesterone. Furthermore, 5% fetal calf serum supplementation was more growth supporting and more significantly reduced the comet number than 250 pM 17 , -oestradiol. Conclusion Cell growth, proliferating cell nuclear antigen expression and DNA damage are dependent on oestrogen or fetal calf serum, but independent of gonadotrophin-releasing hormone agonist or progesterone. Our findings suggest that gonadotrophin-releasing hormone agonist-induced leiomyoma shrinkage may be due in part to a mechanism involving DNA damage, and support the hypothesis that gonadotrophin-releasing hormone agonist exerts its action indirectly through oestrogen action on the tumour level. [source] In vitro polydeoxyribonucleotide effects on human pre-adipocytesCELL PROLIFERATION, Issue 5 2008E. Raposio Objectives: Adipose tissue is the most abundant and accessible source of adult stem cells. Human processed lipoaspirate contains pre-adipocytes that possess one of the a characteristic pathways of multipotent adult stem cells and are able to differentiate in vitro into mesenchymal and also neurogenic lineages. Because stem cells have great potential for use in tissue repair and regeneration, it would be significant to be able to obtain large amounts of these cells in vitro. As demonstrated previously, purine nucleosides and nucleotides mixtures can act as mitogens for several cell types. The aim of this study was to evaluate the effects of polydeoxyribonucleotides (PDRN), at appropriate concentrations, on human pre-adipocytes grown in a controlled medium, also using different passages, so as to investigate the relationship between the effect of this compound and cellular senescence, which is the phenomenon when normal diploid cells lose the ability to divide further. Materials and methods: Human pre-adipocytes were obtained by liposuction. Cells from different culture passages (P6 and P16) were treated with PDRN at different experimental times. Cell number was evaluated for each sample by direct counting after trypan blue treatment. DNA assay and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test were also carried out in all cases. Results and Conclusions: PDRN seemed to promote proliferation of human pre-adipocytes at both passages, but cell population growth increased in pre-adipocyte at P16, after 9 days as compared to control. Our data suggest that PDRN could act as a pre-adipocyte growth stimulator. [source] Use of a novel nonantibiotic triple marker gene cassette to monitor high survival of Pseudomonas fluorescens SBW25 on winter wheat in the fieldFEMS MICROBIOLOGY ECOLOGY, Issue 2 2008Lotta Jäderlund Abstract Pseudomonas fluorescens SBW25 was tagged with a triple marker gene cassette containing gfp, encoding green fluorescent protein; luxAB, encoding luciferase; and telABkilA, encoding tellurite resistance, and the tagged strain was monitored in the first Swedish field release of a genetically modified microorganism (GMM). The cells were inoculated onto winter wheat seeds and the GMM cells (SBW25,tgl) were monitored in the field from September 2005 to May 2006 using plating, luminometry and microscopic analyses. Cell numbers were high on all sampling occasions and metabolically active cells were detected on all plant parts. Field results were similar to those obtained in a parallel phytotron study, although the amount of SBW25,tgl detected on shoots was significantly higher in the phytotron than in the field. After winter, cell counts were 100-fold higher on the roots and root-associated soil compared with prewinter measurements, although the cells had a lower relative metabolic activity. The wheat seeds were naturally infested with Microdochium nivale, but no treatment resulted in reduction of disease symptoms. No SWB25,tgl cells were ever found in bulk soil or uninoculated plants. The Swedish field trial results complement and contrast with prior field studies performed with the same parent organism in the United Kingdom under different soil, plant and climatic conditions. [source] Hippocampal neuron and glial cell numbers in Parkinson's disease,A stereological study,HIPPOCAMPUS, Issue 10 2006F.C. Joelving Abstract Hippocampal atrophy and neuron loss are early and reproducible findings in Alzheimer's disease, and recent magnetic resonance imaging studies indicate that hippocampal atrophy may also be present in Parkinson's disease (PD). To determine whether or not cell loss occurs in PD, we estimated the total neuron and glial cell numbers as well as the total volume unilaterally in the hippocampi of eight demented PD patients and eight control subjects. Cell numbers were estimated in the neuron-containing layers of CA1, CA2-(3), CA4, the dentate gyrus, and subiculum using the optical-fractionator technique. The Cavalieri method was used to estimate the volume of the total hippocampus and its subregions. We did not find significant differences in cell numbers or volumes in PD brains when compared with control subjects. Our results thus indicate that hippocampal atrophy and cell loss are not necessarily involved in the memory impairment and dementia observed in PD. © 2006 Wiley-Liss, Inc. [source] The effect of butyric acid on adhesion molecule expression by human gingival epithelial cellsJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2008S. Takigawa Background and Objective:, Short-chain fatty acids, such as butyric acid, are detected in periodontal pockets and are thought to be involved in the initiation and progression of periodontal disease. In the present study, we examined the effects of butyric acid on adhesion molecule expression by human gingival epithelial cells. Material and methods:, The human gingival carcinoma cell line, Ca9-22, was cultured in media that contained different concentrations of butyric acid. Results:, Cell numbers were significantly decreased in a dose-dependent manner by butyric acid at concentrations of , 0.2 mm. The expression of intercellular adhesion molecule-1 mRNA was significantly increased 6 h after stimulation. By contrast, the expression levels of integrins ,6 and ,4 were decreased. Similar results were obtained by flow cytometry. Conclusion:, The results of the present study indicate that butyric acid alters the expression of adhesion molecules by Ca9-22 cells. The elucidation of the mechanism of action of butyric acid on the periodontium may help to clarify several aspects of the onset and progression of periodontal disease. [source] Antibiotic-resistant obligate anaerobes during exacerbations of cystic fibrosis patientsCLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2009D. Worlitzsch Abstract Pseudomonas aeruginosa and Staphylococcus aureus are thought to cause the majority of lung infections in patients with cystic fibrosis (CF). However, other bacterial pathogens may contribute to the pathophysiology of lung disease. Here, obligate anaerobes were identified in a cross-sectional study, and cell numbers and antibiotic susceptibilities of facultative and obligate anaerobes from 114 sputum samples from nine children and 36 adults with CF were determined. Furthermore, in 12 CF patients, we investigated whether conventional intravenous antibiotic therapy, administered during acute exacerbations, would affect the numbers of obligate anaerobes. Fifteen genera of obligate anaerobes were identified in 91% of the CF patients. Cell numbers (mean: 2.2 × 107 ± standard deviation 6.9 × 107 CFU/mL of sputum sample) were comparable to those of P. aeruginosa and S. aureus. Staphylococcus saccharolyticus and Peptostreptococcus prevotii were most prevalent. Infection with P. aeruginosa did not increase the likelihood that obligate anaerobes are present in sputum specimens. Single obligate anaerobic species persisted for up to 11 months in sputum plugs in vivo. Patients with and without obligate anaerobes in sputum specimens did not differ in lung function. Intravenous therapy directed against P. aeruginosa during acute exacerbations increased lung function, but did not reduce the numbers of obligate anaerobes. Obligate anaerobic species differed widely in their patterns of resistance against meropenem, piperacillin,tazobactam, clindamycin, metronidazole and ceftazidime. In 58% of patients with acute exacerbations, obligate anaerobes were detected that were resistant to the antibiotics used for treatment. Antibiotic therapy, optimized to target anaerobes in addition to P. aeruginosa, may improve the management of CF lung disease. [source] Gravitational unloading inhibits the regenerative potential of atrophied soleus muscle in miceACTA PHYSIOLOGICA, Issue 3 2009Y. Matsuba Abstract Aim:, The present study was performed to investigate the influence of unloading on the regeneration of atrophied and injured skeletal muscle. Methods:, Male mice (C57BL/6J), aged 8 weeks, were used. Cardiotoxin (CTX) was injected into soleus muscles bilaterally. Gravitational unloading on soleus muscle was performed by hind limb suspension for 2 weeks before and additionally 6 weeks after CTX injection in one group. Soleus muscles in the remaining groups were loaded keeping the mice in the cages and were dissected 14, 28 and 42 days after the injection. Results:, Recovery of the wet weight and protein content of soleus in the CTX-injected group was inhibited by unloading. Increase in satellite cell number, induced by CTX injection and loading, was also inhibited by unloading. Disappearance of infiltration of mononucleated cells into the necrotic area was also delayed. This phenomenon suggests that regeneration, which is indicated by the appearance of fibres with central nuclei, was inhibited by unloading. Conclusion:, Results suggested that loading plays an important role in the activation of the regenerating potential of injured skeletal muscle. [source] Cleavage-like cell division and explosive increase in cell number of neonatal gonocytesDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 1 2004Yasuhiro Sakai Based on previous conventional quantitative observations of rat testes, it was proposed that large numbers of gonocytes degenerate after birth and this notion was widely accepted. However, many studies show that neonatal gonocytes display high levels of mitotic activity. In order to resolve the apparent contradiction of increased mitotic activity in gonocytes despite a decrease in their numbers at the neonate stage, quantitative analysis using a marker of suitably higher resolution is required. It has been shown that the vasa protein could be used as a marker of germ cells. In this study, quantitative changes in gonocytes were re-examined using a germ-cell-specific marker in order to delineate more clearly the process of development from gonocytes to spermatogonia after birth. The vasa -positive cells, which correspond to gonocytes and spermatogonia, increased exponentially after birth. This observation suggests that all gonocyte divide actively after birth and do not degenerate as previously believed. Surprisingly, the cell volume of gonocytes decreased during their division. The largest population size was 2000,4000 µ3 at day 2, 1000,2000 µ3 at day 4 and 500,1000 µ3 at day 6. This finding suggests that gonocytes divide in a similar way to cleavage, which can be considered a special mode of fertilized eggs. Judging from the growth of seminiferous tubules and the degree of volume reduction, 60% of the contribution rate is estimated to be due to ordinal cell growth, and 40% due to volume reduction as in cleavage of a fertilized egg. This unique cleavage-like division may contribute to the supply of large numbers of spermatogonia. [source] Two neuron clusters in the stem of postembryonic zebrafish brain specifically express relaxin -3 gene: First evidence of nucleus incertus in fishDEVELOPMENTAL DYNAMICS, Issue 12 2008Aldo Donizetti Abstract We examined the spatial expression of the relaxin -3 gene in the developing zebrafish brain, one of the vertebrate model systems in which this gene has been identified. Until the pharyngula stage, the gene is expressed diffusely in the brain, where, starting at about 40 hpf, the transcripts appear restricted in a midbrain cell cluster of the periaqueductal gray. Later, at 72 hpf, the transcripts are still evident in that cluster and distributed in a larger cell number; at this stage, the gene is also expressed posteriorly, in a smaller cell group that, as we report for the first time, could be homologous to mammalian nucleus incertus. The gene expression persists in both cell clusters at 96 hpf. This pattern indicates both conserved and divergent expression features of the relaxin -3 gene among developing zebrafish and rat brains, where only scattered cells express the gene in the periaqueductal gray. Developmental Dynamics 237:3864,3869, 2008. © 2008 Wiley-Liss, Inc. [source] Homocysteine inhibits cardiac neural crest cell formation and morphogenesis in vivoDEVELOPMENTAL DYNAMICS, Issue 1 2004Brent J. Tierney Abstract Elevated homocysteine increases the risk of neurocristopathies. Here, we determined whether elevating homocysteine altered the proliferation or number of chick neural crest cells that form between the midotic and third somite in vivo. Homocysteine increased the number of neural tube cells but decreased neural crest cell number. However, the sum total of cells was not different from controls. In controls, the 5-bromo-2,-deoxyuridine-labeling index was higher in newly formed neural crest cells than in their progenitors, paralleling reports showing these progenitors must pass the restriction point before undergoing epithelial,mesenchymal transition. Homocysteine decreased the labeling index of newly formed neural crest cells, suggesting that it inhibited cell cycle progression of neural crest progenitors or the S-phase entry of newly formed neural crest cells. Homocysteine also inhibited neural crest dispersal and decreased the distance they migrated from the neural tube. These results show neural crest morphogenesis is directly altered by elevated homocysteine in vivo. Developmental Dynamics 229:63,73, 2004. © 2003 Wiley-Liss, Inc. [source] Environment and prednisone interactions in the treatment of recurrent airway obstruction (heaves)EQUINE VETERINARY JOURNAL, Issue 5 2000C. A. Jackson Summary Recurrent airway obstruction (RAO) or heaves is a manifestation of a hypersensitivity to dust, moulds, and spores in the environment of a susceptible horse. Although in the majority of RAO-affected horses, clinical remission can be achieved by keeping horses at pasture to reduce their allergen exposure, this often is not practicable. For this reason, we investigated if changing the environment of a single stall in a 4 stall stable was sufficient to improve lung function and reduce inflammation in RAO-affected horses. In addition, we determined if addition of oral prednisone provided additional benefit. Twelve RAO-susceptible horses were stabled, fed hay, and bedded on straw until they developed airway obstruction. At this point, bedding was changed to wood shavings and they were fed a pelleted diet for 2 weeks. Lung function was measured and bronchoalveolar lavage was performed before and 3, 7, and 14 days after environmental modification. In a crossover design, horses were treated for the 14 days with prednisone tablets (2.2 mg/kg bwt, q. 24 h). Horses then returned to pasture for 30 days. Airway obstruction was greatest before environmental modification. Significant improvement in lung function occurred within 3 days of the change in environment and continued to Day 7. Airway function was best after 30 days at pasture. The clinical response achieved by environmental modification was not significantly improved by addition of oral prednisone. The total number of cells, total neutrophils, and percent neutrophils was greatest before environmental modification. In the absence of prednisone, total and percent neutrophils did not decrease until Day 14 and total cell number until 30 days at pasture. In the presence of prednisone, total cells and total and percent neutrophils decreased by Day 3 and again at pasture. The fact that lung function can be improved within 3 days by environmental management alone emphasises the need for allergen reduction as the cornerstone of treatment of RAO. Although prednisone induced a more rapid reduction in airway inflammation, this was not associated with a more rapid improvement in airway function. [source] Four peptide hormones decrease the number of human breast adenocarcinoma cellsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2005B. A. Vesely Abstract Background, A family of six hormones, i.e. atrial natriuretic peptide, brain natriuretic peptide, C-natriuretic peptide, long-acting natriuretic peptide, vessel dilator, and kaliuretic peptide's main known biologic properties are sodium and water excreting and blood pressure lowering. Methods and materials, These six hormones, each at their 1-µm concentrations, were evaluated for their ability to decrease the number and/or proliferation of breast adenocarcinoma cells in culture for 24, 48, 72, and 96 h. Results, Within 24 h, vessel dilator, long-acting natriuretic peptide, kaliuretic peptide, atrial natriuretic peptide and 8-bromo-cyclic GMP, a cell-permeable analogue of their intracellular mediator cyclic GMP (each at 1 µm), decreased the number of breast adenocarcinoma cells 60%, 31%, 27%, 40%, and 31%, respectively. There was no proliferation in the 3 days following this decrease in breast adenocarcinoma cell number. These same hormones decreased DNA synthesis 69% to 85% (P < 0·001). Brain natriuretic peptide and CNP did not decrease the number of breast adenocarcinoma cells or inhibit their DNA synthesis. Vessel dilator, long-acting natriuretic peptide, kaliuretic peptide and 8-bromo-cyclic GMP (each at 1 µM) decreased the number of cells in the S phase of the cell cycle by 62%, 33%, 50%, and 39%, respectively (all P < 0·05). Natriuretic peptide receptors-A and -C were present in the breast adenocarcinoma cells. Conclusions, Four peptide hormones significantly decrease the number of human breast adenocarcinoma cells within 24 h and inhibit the proliferation of these cells for at least 96 h. Their mechanism of doing so involves inhibition of DNA synthesis and a decrease in cells in the S phase of the cell cycle mediated in part by cyclic GMP. [source] The fate of heterologous CD4+ T,cells during Leishmania donovani infectionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2005Rosalind Polley Abstract Little is currently understood about the consequences of chronic parasitic infection for the fate of memory CD4+ T,cells that recognize heterologous antigens, e.g. resulting from prior infections or vaccination. Here, we address how Leishmania donovani infection affected the fate of non-cross-reactive (OVA)-specific memory CD4+ T,cells. DO11 cells were adoptively transferred into naive recipient mice, which were then immunized to generate memory DO11 cells. After 6,weeks, mice were infected with L. donovani and the fate of DO11 cells was determined. L. donovani infection stimulated an approximately threefold expansion in the total number of CD4+ T,cells and DO11 cells, compared to that observed in uninfected mice. DO11 T,cells were more actively dividing in infected mice, as judged by 5-bromo-2, deoxyuridine labeling, whereas their rate of apoptosis in control and infected mice was identical. Both CD45RBhiCD44lo naive T,cells and to a greater extent CD45RBloCD44hi memory DO11 cells increased in number in the spleens of infected mice, whereas no changes occurred to DO11 cell number or phenotype in the draining lymph nodes. These data indicate that heterologous CD4+ T,cells may actively divide during chronic infectious diseases, with important implications for how chronic infection may impact on heterologous immunity. [source] Maintenance of the relative proportion of oligodendrocytes to axons even in the absence of BAX and BAKEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2009Kumi Kawai Abstract Highly purified oligodendroglial lineage cells from mice lacking functional bax and bak genes were resistant to apoptosis after in-vitro differentiation, indicating an essential role of the intrinsic apoptotic pathway in apoptosis of oligodendrocytes in the absence of neurons (axons) and other glial cells. These mice therefore provide a valuable tool with which to evaluate the significance of the intrinsic apoptotic pathway in regulating the population sizes of oligodendrocytes and oligodendroglial progenitor cells. Quantitative analysis of the optic nerves and the dorsal columns of the spinal cord revealed that the absolute numbers of mature oligodendrocytes immunolabeled for aspartoacylase and adult glial progenitor cells expressing NG2 chondroitin sulfate proteoglycan were increased in both white matter tracts of adult bax/bak -deficient mice and, to a lesser extent, bax -deficient mice, except that there was no increase in NG2-positive progenitor cells in the dorsal columns of these strains of mutant mice. These increases in mature oligodendrocytes and progenitor cells in bax/bak -deficient mice were unexpectedly proportional to increases in numbers of axons in these white matter tracts, thus retaining the oligodendroglial lineage to axon ratios of at most 1.3-fold of the physiological numbers. This is in contrast to the prominent expansion in numbers of neural precursor cells in the subventricular zones of these adult mutant mice. Our study indicates that homeostatic control of cell number is different for progenitors of the oligodendroglial and neuronal lineages. Furthermore, regulatory mechanism(s) operating in addition to apoptotic elimination through the intrinsic pathway, appear to prevent the overproduction of highly mitotic oligodendroglial progenitor cells. [source] Inactivation of the gene for the nuclear receptor tailless in the brain preserving its function in the eyeEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2007Thorsten Belz Abstract During embryogenesis, tailless, an orphan member of the nuclear receptor family, is expressed in the germinal zones of the brain and the developing retina, and is involved in regulating the cell cycle of progenitor cells. Consequently, a deletion of the tailless gene leads to decreased cell number with associated anatomical defects in the limbic system, the cortex and the eye. These structural abnormalities are associated with blindness, increased aggressiveness, poor performance in learning paradigms and reduced anxiousness. In order to assess the contribution of blindness to the behavioural changes, we established tailless mutant mice with intact visual abilities. We generated a mouse line in which the second exon of the tailless gene is flanked by loxP sites and crossed these animals with a transgenic line expressing the Cre recombinase in the neurogenic area of the developing brain, but not in the eye. The resulting animals have anatomically indistinguishable brains compared with tailless germline mutants, but are not blind. They are less anxious and much more aggressive than controls, like tailless germline mutants. In contrast to germline mutants, the conditional mutants are not impaired in fear conditioning. Furthermore, they show good performance in the Morris water-maze despite severely reduced hippocampal structures. Thus, the pathological aggressiveness and reduced anxiety found in tailless germline mutants are due to malformations caused by inactivation of the tailless gene in the brain, but the poor performance of tailless null mice in learning and memory paradigms is dependent on the associated blindness. [source] Hippocampal granule neuron production and population size are regulated by levels of bFGFEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2002Yinghong Cheng Abstract Numerous studies of the proliferative effects of basic fibroblast growth factor (bFGF) in culture, including neonatal and adult hippocampal precursors, suggest that the factor plays a ubiquitous and life-long role in neurogenesis. In contrast, in vivo, bFGF is devoid of effects on neurons in mature hippocampus, raising the possibility that bFGF exhibits developmental stage-specific activity in the complex animal environment. To define neurogenetic effects in the newborn, a single subcutaneous injection of bFGF (20 ng/gm) was administered to postnatal day 1 (P1) rats, and hippocampal DNA content was quantified: bFGF elicited an increase in total DNA throughout adulthood, by 48% at P4, 25% at P22, and 17% at P180, suggesting that bFGF increases hippocampal cell number. To define mechanisms, bromodeoxyuridine (BrdU) was injected at P1 and mitotically labelled cells were assessed at P22: there was a twofold increase in BrdU-positive cells in the dentate granule cell layer (GCL), indicating that bFGF enhanced the generation of neurons, or neuronogenesis, from a cohort of precursors. Moreover, enhanced mitosis and survival led to a 33% increase in absolute GCL neuron number, suggesting that neuron production depends on environmental levels of bFGF. To evaluate this possibility, bFGF-knockout mice were analyzed: hippocampal DNA content was decreased at all ages examined (P3, ,42%; P21, ,28%; P360, ,18%), and total GCL neuron and glial fibrillary acidic protein (GFAP)-positive cell number were decreased by 30%, indicating that bFGF is necessary for normal hippocampal neurogenesis. We conclude that environmental levels of bFGF regulate neonatal hippocampal neurogenesis. As adult hippocampal neuronogenesis was unresponsive to bFGF manipulation in our previous study [Wagner, J.P., Black, I.B. & DiCicco-Bloom, E. (1999) J. Neurosci., 19, 6006], these observations suggest distinct, stage-specific roles of bFGF in the dentate gyrus granule cell lineage. [source] Mass Fabrication of Small Cell Spheroids by Using Micro-patterned Tissue Culture Plate,ADVANCED ENGINEERING MATERIALS, Issue 10 2009Akinari Iwasaki A newly designed micro-patterned chamber was utilized to fabricate cell spheroids with a constant size (<200,,m) and cell number. By applying cytochalasin D as a chemical to control cell adhesion and aggregation, thousands of aggregated cells were formed in each patterned chamber. Importantly, the formed cell spheroids were collected by a simple pipetting process without using proteinase. [source] DIFFERENT CELL SIZE AND CELL NUMBER CONTRIBUTION IN TWO NEWLY ESTABLISHED AND ONE ANCIENT BODY SIZE CLINE OF DROSOPHILA SUBOBSCURAEVOLUTION, Issue 3 2003Federico C. F. Calboli Abstract Latitudinal genetic clines in body size occur in many ectotherms including Drosophila species. In the wing of D. melanogaster, these clines are generally based on latitudinal variation in cell number. In contrast, differences in wing area that evolve by thermal selection in the laboratory are in general based on cell size. To investigate possible reasons for the different cellular bases of these two types of evolutionary response, we compared the newly established North and South American wing size clines of Drosophila subobscura. The new clines are based on latitudinal variation in cell area in North America and cell number in South America. The ancestral European cline is also based on latitudinal variation in cell number. The difference in the cellular basis of wing size variation in the American clines, which are roughly the same age, together with the similar cellular basis of the new South American cline and the ancient European one, suggest that the antiquity of a cline does not explain its cellular basis. Furthermore, the results indicate that wing size as a whole, rather than its cellular basis, is under selection. The different cellular bases of different size clines are most likely explained either entirely by chance or by different patterns of genetic variance,or its expression,in founding populations. [source] Dictyostelium differentiation-inducing factor-1 induces glucose transporter 1 translocation and promotes glucose uptake in mammalian cellsFEBS JOURNAL, Issue 13 2007Waka Omata The differentiation-inducing factor-1 (DIF-1) is a signal molecule that induces stalk cell formation in the cellular slime mold Dictyostelium discoideum, while DIF-1 and its analogs have been shown to possess antiproliferative activity in vitro in mammalian tumor cells. In the present study, we investigated the effects of DIF-1 and its analogs on normal (nontransformed) mammalian cells. Without affecting the cell morphology and cell number, DIF-1 at micromolar levels dose-dependently promoted the glucose uptake in confluent 3T3-L1 fibroblasts, which was not inhibited with wortmannin or LY294002 (inhibitors for phosphatidylinositol 3-kinase). DIF-1 affected neither the expression level of glucose transporter 1 nor the activities of four key enzymes involved in glucose metabolism, such as hexokinase, fluctose 6-phosphate kinase, pyruvate kinase, and glucose 6-phosphate dehydrogenase. Most importantly, stimulation with DIF-1 was found to induce the translocation of glucose transporter 1 from intracellular vesicles to the plasma membranes in the cells. In differentiated 3T3-L1 adipocytes, DIF-1 induced the translocation of glucose trasporter 1 (but not of glucose transporter 4) and promoted glucose uptake, which was not inhibited with wortmannin. These results indicate that DIF-1 induces glucose transporter 1 translocation and thereby promotes glucose uptake, at least in part, via a inhibitors for phosphatidylinositol 3-kinase/Akt-independent pathway in mammalian cells. Furthermore, analogs of DIF-1 that possess stronger antitumor activity than DIF-1 were less effective in promoting glucose consumption, suggesting that the mechanism of the action of DIF-1 for stimulating glucose uptake should be different from that for suppressing tumor cell growth. [source] Ouabain stimulates endothelin release and expression in human endothelial cells without inhibiting the sodium pumpFEBS JOURNAL, Issue 5 2004Robert Saunders Ouabain, a sodium pump (Na+/,K+ -ATPase) inhibitor, has been shown to act as a hormone and is possibly involved in the pathogenesis of hypertension. The mechanism by which ouabain may act was investigated using primary cultures of human umbilical artery endothelial cells (HUAECs), which are known to express and release the vasoconstrictive hormone endothelin (ET-1). Five minutes after application, low concentrations of ouabain induced Ca2+ oscillations and stimulated ET-1 release from endothelial cells into the medium. To investigate whether the observed effects were due to inhibition of the sodium pump, the effects of ouabain on the uptake of 86Rb+ by HUAECs were examined. Unexpectedly, ouabain concentrations below 10 nm stimulated 86Rb+ uptake by 15,20%, and in some experiments by 50%, results that are consistent with a stimulation of the pump. Within the concentration range 1,10 nm, ouabain induced a 2.5-fold stimulation (phosphorylation) of mitogen-activated protein kinase (MAP kinase). After incubation of HUAECs with ouabain for 12 h, the glycoside stimulated cell growth by 49 ± 4%, as measured by cell number, with a maximum response at 5 nm. At similar concentrations, ouabain also increased ET-1 mRNA abundance by 19.5 ± 3.1%. The results indicate that, by influencing ET-1 expression and release, ouabain may contribute to the regulation of vascular tone. The data also confirm that it is not a global inhibition of the sodium pump that is involved in the mechanism of action of this cardiac glycoside. [source] Effect of suramin on the human pathogen Candida albicans: implications on the fungal development and virulenceFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2007Lys Adriana Braga-Silva Abstract Candida albicans is an opportunistic pathogen that is of growing medical importance because it causes superficial, mucosal and systemic infections in susceptible individuals. Here, the effect of suramin, a polysulfonated naphthylurea derivative, on C. albicans development and virulence was evaluated. Firstly, it was demonstrated that suramin (500 ,M) arrested its growth, showing a fungicidal action dependent on cell number. Suramin treatment caused profound changes in the yeast ultrastructure as shown by transmission electron microscopy. The more important changes were the enlargement of the fungi cytoplasmic vacuoles, the appearance of yeasts with an empty cytoplasm resembling ghost cells and a reduction in cell wall thickness. Suramin also blocked the transformation of yeast cells to the germ-tube and the interaction between C. albicans and epithelial cells. In order to ascertain that the action of suramin on C. albicans growth is a general feature instead of being strain-specific, the effects of suramin on 14 oral clinical strains isolated from healthy children and HIV-positive infants were analyzed. Interestingly, the strains of C. albicans isolated from HIV-positive patients were more resistant to suramin than strains isolated from healthy patients. Altogether, the results produced here show that suramin interfered with essential fungal processes, such as growth, differentiation and interaction with host cells. [source] Temporal dynamics and growth of Actinophrys sol (Sarcodina: Heliozoa), the top predator in an extremely acidic lakeFRESHWATER BIOLOGY, Issue 6 2006ELANOR M. BELL Summary 1. The in situ abundance, biomass and mean cell volume of Actinophrys sol (Sarcodina: Heliozoa), the top predator in an extremely acidic German mining lake (Lake 111; pH 2.65), were determined over three consecutive years (spring to autumn, 2001,03). 2. Actinophrys sol exhibited pronounced temporal and vertical patterns in abundance, biomass and mean cell volume. Increasing from very low spring densities, maxima in abundance and biomass were observed in late June/early July and September. The highest mean abundance recorded during the study was 7 × 103 Heliozoa L,1. Heliozoan abundance and biomass were higher in the epilimnion than in the hypolimnion. Actinophrys sol cells from this acidic lake were smaller than individuals of the same species found in other aquatic systems. 3. We determined the growth rate of A. sol using all potential prey items available in, and isolated and cultured from, Lake 111. Prey items included: single-celled and filamentous bacteria of unknown taxonomic affinity, the mixotrophic flagellates Chlamydomonas acidophila and Ochromonas sp., the ciliate Oxytricha sp. and the rotifers Elosa worallii and Cephalodella hoodi. Actinophrys sol fed over a wide-size spectrum from bacteria to metazoans. Positive growth was not supported by all naturally available prey. Actinophrys sol neither increased in cell number (k) nor biomass (kb) when starved, with low concentrations of single-celled bacteria or with the alga Ochromonas sp. Positive growth was achieved with single-celled bacteria (k = 0.22 ± 0.02 d,1; kb = ,0.06 ± 0.02 d,1) and filamentous bacteria (k = 0.52 ± <0.01 d,1; kb = 0.66 d,1) at concentrations greater than observed in situ, and the alga C. acidophila (up to k = 0.43 ± 0.03 d,1; kb = 0.44 ± 0.04 d,1), the ciliate Oxytricha sp. (k = 0.34 ± 0.01 d,1) and in mixed cultures containing rotifers and C. acidophila (k = 0.23 ± 0.02,0.32 ± 0.02 d,1; maximum kb = 0.42 ± 0.05 d,1). The individual- and biomass-based growth of A. sol was highest when filamentous bacteria were provided. 4. Existing quantitative carbon flux models for the Lake 111 food web can be updated in light of our results. Actinophrys sol are omnivorous predators supported by a mixed diet of filamentous bacteria and C. acidophila in the epilimnion. Heliozoa are important components in the planktonic food webs of ,extreme' environments. [source] Nerve growth factor attenuates proliferation of astrocytes via the p75 neurotrophin receptorGLIA, Issue 13 2009Andrea B. Cragnolini Abstract The p75 neurotrophin receptor has been implicated in the regulation of multiple cellular functions that differ depending on the cell context. We have observed that p75NTR is strongly induced on astrocytes as well as neurons in the hippocampal CA3 region after seizures; however, the function of this receptor on these glial cells has not been defined. We have employed a primary culture system to investigate the effects of neurotrophins on astrocytes. Treatment of hippocampal astrocytes with nerve growth factor (NGF) caused a reduction in cell number, but did not elicit an apoptotic response, in contrast to hippocampal neurons. Instead, activation of p75NTR by NGF attenuated proliferation induced by mitogens such as EGF or serum. These studies demonstrate the cell type specificity of neurotrophin functions in the brain. © 2009 Wiley-Liss, Inc. [source] Alloantigen gene therapy for head and neck cancer: Evaluation of animal models,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 4 2003Lyon L. Gleich MD Abstract Background. Human trials of alloantigen gene therapy, using the class I major histocompatibility complex (MHC) HLA-B7, have demonstrated the potential efficacy of this treatment for head and neck cancer. Its mechanism remains unclear. An immune-competent mouse model of MHC gene therapy to test factors potentially important to the tumor response is needed. Methods. Two cell lines were used, B4B8 cells that grow in Balb/c mice and SCC-VII cells that grow in C3H mice. The mouse MHC H2-Kb was used as the therapeutic gene, because it is an alloantigen to both mice strains. Plasmids that encode the H2-Kb cDNA were prepared, and the cell lines were transfected. Mice were injected subcutaneously with naive cells to determine the tumor kinetics and serve as controls. Mice were injected with H2-Kb transfected cells and tumor growth was compared with controls. Mice that did not grow tumor were rechallenged with naive cells to assess for tumor immunity. Mice were injected with transfected and naive cells admixed to determine whether the concentration of the alloantigen is important. Results. B4B8 tumors grew slowly, whereas SCC-VII tumors grew rapidly. Transfection with H2-Kb plasmid prevented or inhibited tumor growth of both the B4B8 and SCC-VII tumors. This growth inhibition was independent of the number of cells injected. In the mice that did not grow tumor, tumor immunity was demonstrated after challenge with naive cells in both models. There was no relationship between induction of immunity and the timing of the challenge or initial cell quantity. The mice injected with a mixture of naive and transfected cells grew tumor, although growth was delayed in the B4B8 model. Conclusions. The results demonstrate that the two mouse models can serve as a rapid and slow growing tumor model of alloantigen gene therapy. In addition, it was noted that initial tumor cell number is not a significant factor for predicting tumor response and demonstrated that in both of these models alloantigen gene therapy results in significant antitumor immunity. © 2003 Wiley Periodicals, Inc. Head Neck 25: 274,279, 2003 [source] | |||||||||||||||||||||||||||||||||||||