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Detectable Amounts (detectable + amount)
Selected AbstractsMicrostructural and crystallographic surface changes after grinding zirconia-based dental ceramicsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2006I. L. Denry Abstract The purpose of this study was to evaluate microstructural and crystallographic phase changes after grinding 3Y-TZP dental ceramics. Ceramic blanks were sintered according to manufacturer's recommendations and divided into four groups: (A) as-sintered control, (B) diamond-ground manually under water, (C) ground and polished, and (D) ground and annealed at 1000°C for 1 h. Bulk specimens were analyzed by X-ray diffraction to characterize the crystalline phases. The microstructure was investigated by SEM. XRD analyses showed that the control group and the group that was ground and annealed contained only tetragonal zirconia. However, after grinding or after grinding followed by polishing, rhombohedral zirconia and strained tetragonal zirconia were present, without any detectable amount of monoclinic zirconia. Annealing led to the disappearance of both residual lattice strain and the rhombohedral phase. The microstructure of the ground and polished specimens was characterized by significant residual surface damage associated with grain pullout to a depth of about 20 ,m. This type of damage could have an impact on the long-term fatigue behavior of 3Y-TZP. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source] Densitometric determination of zinc bacitracin and nystatin in animal feedJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2008Rade Injac Abstract BACKGROUND: The European Union has forbidden the use of antibiotics as additives in animal feed. Zn-bacitracin (Zn-BC) and nystatin (NYS) were frequently used for their growth-promoting effects and for feed conversion in poultry, pigs and cattle. An HPTLC method has been developed for separating Zn-BC and NYS in the mixture, for routine quality control. RESULTS: The separation was obtained using RP-18 F254S coated HPTLC plates with acetonitrile/methanol (equal volumes):toluene:KH2PO4/KOH (buffer, pH 6.8) = 57:3:40 (v/v/v), adjusted with HCl to pH 8.2, as a mobile phase. The densitograms were monitored at 192, 215 and 305 nm and both antibiotics were assayed at 215 nm. The method was shown to be specific, accurate (recoveries were 98.7 ± 0.5% and 104.8 ± 0.7% for Zn-BC and NYS, respectively), linear over the tested range (correlation coefficients, 0.9982 and 0.9884), and precise (intermediate precision RSD below 2.2% for both analytes) with efficient separation (Rs = 3.5). CONCLUSION: The method was applied for determining Zn-BC and NYS as additives in spiked matrices of commercial animal feedstuffs. According to LOD values for each antibiotic, the minimum detectable amount in feed is 4.5 and 5.5 ppm of Zn-BC and NYS, respectively. Copyright © 2008 Society of Chemical Industry [source] Antibody responses to the host-protective Taenia solium oncosphere protein TSOL18 in pigs are directed against conformational epitopesPARASITE IMMUNOLOGY, Issue 6 2010E. ASSANA Summary TSOL18 is a recombinant protein that has been shown in repeated experimental trials to be capable of protecting pigs against challenge infection with the cestode parasite Taenia solium. Antibodies raised by the vaccine are capable of killing the parasite in an in vitro culture and it is believed that antibody and complement-mediated killing of invading parasites is the major protective immune mechanism induced by vaccination with TSOL18. Investigations were undertaken to characterize whether the principal antibody specificities raised by TSOL18 in pigs were against linear or conformational determinants. TSOL18 was expressed in two truncated forms representing either the amino terminal portion or the carboxy terminal portion, with the two truncations overlapping in sequence by 25 amino acids. The original protein (designated TSOL18N,) and the two truncations (TSOL18N, -1 and TSOL18N, -2) were used in inhibition ELISA. TSOL18N, was shown to be capable of completely inhibiting the binding of pig anti-TSOL18N, antibodies to TSOL18N, in ELISA. However, neither TSOL18N, -1 nor TSOL18N, -2, either alone or when combined together, was capable of inhibiting any detectable amount of reactivity of pig anti-TSOL18N, antibodies with TSOL18N,. It is concluded that the dominant antibody specificities, and probably the host-protective specificities, of TSOL18 are conformational epitopes. [source] Secreted production of Renilla luciferase in Bacillus subtilisBIOTECHNOLOGY PROGRESS, Issue 2 2010Chung-Jen Chiang Abstract Luciferase (Rluc) from the soft coral Renilla reniformis has been widely used as a bioluminescent reporter, and its secreted production has been solely performed in mammalian cells thus far. To make the production more efficient, a series of approaches was attempted to overproduce Rluc extracellularly in Bacillussubtilis. First, Cys124 in the Rluc gene was substituted with Ala. The mutant gene was subsequently incorporated into a pUB110/R6K-based plasmid, consequently, fusing with the P43 promoter and the sacB signal peptide. With the nitrogen-rich medium, B. subtilis strain bearing the plasmid became able to secret a detectable amount of Rluc. Moreover, the secretion signal for the Rluc gene was replaced by the aprN leader peptide with or without the propeptide. The result led to a more than twofold increase in the secreted Rluc. Finally, by enhancing the transcription of the Rluc gene implementing the P43 and spac tandem promoter, it resulted in the secreted Rluc with a yield of 100 mg/L. Overall, this study illustrates a potential strategy for improving the secretion efficiency of heterologous proteins in B. subtilis. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] The concentration of hydrogen peroxide generated during aggregation of ,-synuclein in vitro is lower than 5 nmol/LCHINESE JOURNAL OF CHEMISTRY, Issue 12 2004Li-Na Ji Abstract Using a fluorometric method with a detection limit of 5 nmol/L. here it is reported that albeit positive results were got from bovine serum albumin (BSA) and chicken ovalbumin (OVA) as published in literature, no detectable amount of hydrogen peroxide (H2O2) was generated during ,-synuclein (,-Syn) aggregation in vitro even in the presence of transition metal ions Cu(II) or Fe(III). The results suggest that the concentration of H2O2 generated during aggregation of ,-Syn in vitro be lower than 5 nmol/L beyond the detection limit of the adopted method and it is far too poor to be responsible for the cytotoxicity of ,-Syn aggregates, thus allowing people to extensively elucidate the mechanism underlying neurotoxicities of the aggregates formed by some amyloidogenic proteins. [source] Low serum concentration of sulfatide and presence of sulfated lactosylceramid are associated with Type 2 diabetes.DIABETIC MEDICINE, Issue 9 2005The Skaraborg Project Abstract Aims The glycosphingolipid sulfatide (sulfated galactosyl-ceramide) increases exocytosis of ,-cell secretory granules, activates KATP -channels and is thereby able to influence insulin secretion through its presence in the islets. A closely related compound, sulfated lactosylceramide (sulf-lac-cer), is present in the islets during fetal and neonatal life when, as in Type 2 diabetes, insulin is secreted autonomically without the usual first phase response to glucose. The aim was to examine whether serum concentrations of these glycolipids are associated with Type 2 diabetes. Methods A case,control study, comprising 286 women and 283 men, was designed using a population-based sample of patients with Type 2 diabetes and a population survey. Results Low serum concentrations of sulfatide were associated with Type 2 diabetes, independent of traditional risk factors for diabetes in a sex-specific analysis: odds ratio (OR) 2.1 (95% confidence interval 1.1, 3.9) in men, and 2.3 (1.2, 4.3) in women, comparing the lowest and the highest tertiles. Type 2 diabetes was also associated with detectable amounts of sulf-lac-cer in serum: OR 1.7 (0.9, 3.4) in men, and 7.6 (3.8, 15.2) in women. After adjustment for confounding from other diabetes risk factors, these associations remained basically unchanged. The connections between sulfatide and Type 2 diabetes, and sulf-lac-cer and Type 2 diabetes were independent of each other. Insulin resistance (HOMA-IR) was negatively correlated with sulfatide concentration and positively correlated with sulf-lac-cer (both P < 0.0001, independently). Conclusions We report a new, robust and highly significant independent association between Type 2 diabetes and serum concentrations of sulfatide in both sexes, and sulf-lac-cer in females. The associations were also independent of other known diabetes risk factors. [source] Nerve growth factor ,/pro-nerve growth factor and their receptors in normal human oral mucosaEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2007Katsuhiko Hayashi Nerve growth factor , (NGF- ,) and its precursor proNGF are important for the differentiation and survival of neurons and dermal keratinocytes. The aim of this study was to determine the role that NGF might play in the differentiation and wound healing of oral mucosa. Cultured normal human oral mucosal keratinocytes expressed mRNA for NGF- ,/proNGF and for their receptors TrkA and p75NTR. Lysates from cultured oral mucosal keratinocytes did not contain detectable amounts of mature 14-kDa NGF- , but did contain several NGF proforms with molecular weights between 32 and 114 kDa. Culture medium from oral mucosal keratinocytes contained 75 kDa proNGF. The addition of NGF- , significantly enhanced the proliferation of oral mucosal keratinocyte cultures and in vitro scratch closure. Immunostaining of biopsies from normal oral mucosa showed the presence of proNGF in all epithelial layers. NGF staining was observed in the granular and upper spinous cell layers. TrkA immunoreactivity was detected in basal and parabasal cells, with weak to moderate staining in spinous and granular cell layers. p75NTR staining was seen in basal cell layers. These findings indicate that NGF- ,/proNGF have mitogenic and motogenic effects on oral mucosal keratinocytes and therefore may aid in the healing of oral wounds. Differential expression of NGF and NGF receptors throughout the epithelium suggests a role in epithelial differentiation. [source] Biogeochemical changes induced in uranium mining waste pile samples by uranyl nitrate treatments under anaerobic conditionsGEOBIOLOGY, Issue 3 2009A. GEISSLER Response of the subsurface soil bacterial community of a uranium mining waste pile to treatments with uranyl nitrate over different periods of time was studied under anaerobic conditions. The fate of the added U(VI) without supplementation with electron donors was investigated as well. By using 16S rRNA gene retrieval, we demonstrated that incubation with uranyl nitrate for 4 weeks resulted in a strong reduction in and even disappearance of some of the most predominant bacterial groups of the original sample. Instead, a strong proliferation of denitrifying and uranium-resistant populations of Rahnella spp. from Gammaproteobacteria and of Firmicutes occurred. After longer incubations for 14 weeks with uranyl nitrate, bacterial diversity increased and populations intrinsic to the untreated samples such as Bacteroidetes and Deltaproteobacteria propagated and replaced the above-mentioned uranium-resistant groups. This indicated that U(VI) was immobilized. Mössbauer spectroscopic analysis revealed an increased Fe(III) reduction by increasing the incubation time from four to 14 weeks. This result signified that Fe(III) was used as an electron acceptor by the bacterial community established at the later stages of the treatment. X-ray absorption spectroscopic analysis demonstrated that no detectable amounts of U(VI) were reduced to U(IV) in the time frames of the performed experiments. The reason for this observation is possibly due to the low level of electron donors in the studied oligotrophic environment. Time-resolved laser-induced fluorescence spectroscopic analysis demonstrated that most of the added U(VI) was bound by organic or inorganic phosphate phases both of biotic origin. [source] C-reactive protein in gingival crevicular fluid may be indicative of systemic inflammationJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2010Emma Megson Megson E, Fitzsimmons T, Dharmapatni K, Bartold PM. C-reactive protein in gingival crevicular fluid may be indicative of systemic inflammation. J Clin Periodontol 2010; 37: 797,804. doi: 10.1111/j.1600-051X.2010.01603.x. Abstract Background and Aim: Periodontitis is associated with elevated C-reactive protein (CRP) in both serum and gingival crevicular fluid (GCF). Although the liver is the primary source of CRP, extra-hepatic production of CRP has been reported. This study aimed to determine whether CRP in GCF is produced locally in the gingivae. Materials and Methods: Gingivae and GCF were collected from non-periodontitis and periodontitis sites. Presence of CRP in gingivae was assessed by immunohistochemistry. CRP in GCF was measured using ELISA. Gene expression for CRP in gingivae was determined using real-time polymerase chain reaction. Results: CRP was found in both the gingivae and GCF. No gingivae had detectable amounts of CRP mRNA. Not all patients with periodontitis had detectable levels of CRP in the GCF. Some non-periodontitis patients had detectable levels of CRP in the GCF. Conclusion: CRP in the GCF appears to be of systemic origin, and therefore may be indicative of systemic inflammation from either a periodontal infection or inflammatory disease elsewhere. The correlation between levels of CRP in GCF and serum requires validation in future studies. [source] A new precipitation technique provides evidence for the permeability of Casparian bands to ions in young roots of corn (Zea mays L.) and rice (Oryza sativa L.)PLANT CELL & ENVIRONMENT, Issue 11 2005KOSALA RANATHUNGE ABSTRACT Using an insoluble inorganic salt precipitation technique, the permeability of cell walls and especially of endodermal Casparian bands (CBs) for ions was tested in young roots of corn (Zea mays) and rice (Oryza sativa). The test was based on suction of either 100 µm CuSO4 or 200 µm K4[Fe(CN)6] into the root from its medium using a pump (excised roots) or transpirational stream (intact seedlings), and subsequent perfusion of xylem of those root segments with the opposite salt component, which resulted in precipitation of insoluble brown crystals of copper ferrocyanide. Under suction, Cu2+ could cross the endodermis apoplastically in both plant species (although at low rates) developing brown salt precipitates in cell walls of early metaxylem and in the region between CBs and functioning metaxylem vessels. Hence, at least Cu2+ did cross the endodermis dragged along with the water. The results suggested that CBs were not perfect barriers to apoplastic ion fluxes. In contrast, ferrocyanide ions failed to cross the mature endodermis of both corn and rice at detectable amounts. The concentration limit of apoplastic copper was 0.8 µm at a perfusion with 200 µm K4[Fe(CN)6]. Asymmetric development of precipitates suggested that the cation, Cu2+, moved faster than the anion, [Fe(CN)6]4,, through cell walls including CBs. Using Chara cell wall preparations (,ghosts') as a model system, it was observed that, different from Cu2+, ferrocyanide ions remained inside wall-tubes suggesting a substantially lower permeability of the latter which agreed with the finding of an asymmetric development of precipitates. In both corn and rice roots, there was a significant apoplastic flux of ions in regions where laterals penetrated the endodermis. Overall, the results show that the permeability of CBs to ions is not zero. CBs do not represent a perfect barrier for ions, as is usually thought. The permeability of CBs may vary depending on growth conditions which are known to affect the intensity of formation of bands. [source] ORIGINAL ARTICLE: Characterization of Cytokine Production by Human Term Placenta Macrophages In VitroAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 6 2008Oleg Pavlov Problem, Macrophages are apparently the only immune cells within placenta villi, yet functions of these cells remain obscure. It has been postulated that placental macrophages accomplish regulatory roles at the fetal,maternal interface by means of wide variety of secreted cytokines. We attempt to analyze the patterns of cytokine production in an isolated population of placental macrophages. Method of study, Macrophages were obtained from term placentas in the absence of spontaneous labor. The basal and lipopolysaccharide (LPS)-stimulated levels of intracellular cytokines were detected by flow cytometry. The basal cytokine secretion was determined by BDŌCytometry Bead Array (BD Biosciences, San Diego, CA, USA). Results, Intracellular IL-1,, IL-1,, IL-6, and TNF, were detected in 31, 27, 4, and 3% CD68+ cells, respectively. Stimulation with LPS increased the proportions of cytokine-producing CD68+ cells to 48, 50, 28, and 49%, respectively. Under basal conditions, levels of released TNF, and IL-6, respectively, were 20- and 25-fold higher when compared with IL-1, while IL-10 was secreted in small but detectable amounts. When a secretory activity was estimated for cytokine-producing cells, the secretion rate for TNF, and IL-6 overwhelmingly surpassed that for IL-1, (TNF,:IL-6:IL-1, ratio was 192:145:1). Conclusion, These results suggest functional heterogeneity of the placental macrophage population and contribute to the elucidation of regulatory roles of these cells in gestation. [source] A dominant nuclear mutation in Chlamydomonas identifies a factor controlling chloroplast mRNA stability by acting on the coding region of the atpA transcriptTHE PLANT JOURNAL, Issue 6 2002Dominique Drapier Summary We have characterized a nuclear mutation, mda1 -ncc1, that affects mRNA stability for the atpA gene cluster in the chloroplast of Chlamydomonas. Unlike all nuclear mutations altering chloroplast gene expression described to date, mda1 -ncc1 is a dominant mutation that still allows accumulation of detectable amounts of atpA mRNAs. At variance with the subset of these mutations that affect mRNA stability through the 5, UTR of a single chloroplast transcript, the mutated version of MDA1 acts on the coding region of the atpA message. We discuss the action of MDA1 in relation to the unusual pattern of expression of atpA that associates particularly short lived-transcripts with a very high translational efficiency. [source] Longitudinal study of the spread of ovine Johne's disease in a sheep flock in southeastern New South WalesAUSTRALIAN VETERINARY JOURNAL, Issue 4 2005L RAST Objective The aim of this study was to apply whole flock testing over time to determine the prevalence, distribution and spread of infection in a recently infected flock, with a view to planning intervention strategies for disease control. Procedure Serology, pooled faecal culture (PFC) and histology were used to determine the distribution and persistence of infection in a sheep flock in south east New South Wales between 1997 and 2002. Partial flock testing was done up to June 2000, after which annual whole flock testing, using PFC was performed. Results Faecal shedding of M a paratuberculosis was not detected in home-bred sheep until 7 years after the introduction of infected sheep in 1993. For at least 7 years there was clustering of infection and shedding within two age groups only. The infected groups appeared to have been exposed to infection (mycobacterial contamination) at an early age (< 12 months) and commenced shedding at 5 years of age or older. Groups that were exposed to contamination as adults did not shed detectable amounts of M a paratuberculosis during the study period. Conclusion Clustering of detectable infection in age groups of sheep that were exposed as lambs was a feature on this farm, providing indirect evidence of finite duration of survival of M a paratuberculosis on pasture and the influence of age on the susceptibility of sheep to develop detectable M a paratuberculosis infection. Spread of infection occurred very slowly and was probably related to the long incubation period (exposure to shedding interval) of 5 years observed on this farm. The findings suggest that partial flock culling, selective grazing management and vaccination could lead to a reduction in mycobacterial contamination on farm to a level at which patent infection no longer occurs. Better understanding of disease spread within flocks over time through flock profiling using PFC will help in devising surveillance strategies (including testing protocols for market assurance testing) to detect infected flocks where there has been clustering and slow spread of infection. [source] Recovery of Poly(3-hydroxybutyrate) from Coagulated Ralstoniaeutropha Using a Chemical Digestion MethodBIOTECHNOLOGY PROGRESS, Issue 4 2000Hee Wook Ryu For economic recovery of poly(3-hydroxybutyrate) (PHB) from culture broths of Ralstonia eutropha containing PHB, Al-based and Fe-based coagulants were used in the pretreatment step. The coagulated cells were then separated by centrifugation, and PHB was extracted by chemical digestion with a sodium hypochlorite/chloroform dispersion solution. The practical upper limits of dosage were found to be 1,500 mg-Al/L and 1,000 mg-Fe/L, respectively, for Al- and Fe-based coagulants. When the harvested cells were treated with a 50% sodium hypochlorite/chloroform dispersion solution, PHB recovery and purity were 90,94% and 98,99%, respectively. The influence of the use of coagulants on the PHB recovery process was found to be insignificant. Despite the residual Al and Fe in the recovered PHB (less than 450 mg-Al/kg-PHB and 750 mg-Fe/kg-PHB, respectively), no detectable amounts of Al and Fe were leached from films made of the recovered PHB under acidic conditions. The use of Fe-based coagulants is less recommended because the Fe impurity can cause an unwanted colorization problem in the final product. [source] Impaired host defense to Klebsiella pneumoniae infection in mice treated with the PDE4 inhibitor rolipramBRITISH JOURNAL OF PHARMACOLOGY, Issue 5 2003A C Soares The increase in levels of cAMP in leukocytes by selective inhibitors of PDE4 may result in reduction of inflammation, and may be useful in the treatment of pulmonary inflammatory disorders in humans. Here, we have assessed whether oral treatment with the prototype PDE4 inhibitor, rolipram, interfered with the antibacterial host response following pulmonary infection of mice with Klebsiella pneumoniae. K. pneumoniae infection induced a marked increase in the recruitment of neutrophils to the lungs and the production of proinflammatory cytokines and chemokines, including tumor necrosis factor- , (TNF- ,) and keratinocyte-derived chemokine (KC), in bronchoalveolar (BAL) fluid and lung tissue. There were also detectable amounts of interleukin-10 (IL-10) and significant lethality. Treatment with rolipram (3,30 mg kg,1) was associated with earlier lethality and significant inhibition of the TNF- , production. This was associated with enhanced production of IL-10 in lung tissue of rolipram-treated animals. Rolipram treatment did not affect KC expression and the recruitment of neutrophils in the lung tissue. Over 70% of neutrophils that migrated into the BAL fluid following K. pneumoniae infection ingested bacteria. Treatment with rolipram inhibited the percentage of neutrophils undergoing phagocytosis of K. pneumoniae in a dose-dependent manner. Maximal inhibition (62%) occurred at doses equal to or greater than 10 mg kg,1. Thus, treatment of mice with the PDE4 inhibitor rolipram is accompanied by earlier lethality, enhanced bacterial load and decreased capacity of the responding host to produce TNF- , and of neutrophils to phagocytose bacteria. It will be important to investigate whether the shown ability of PDE4 inhibitors to inhibit neutrophil phagocytosis and control experimental bacterial infection will translate into an inhibition of the ability of neutrophils to deal with infectious microorganisms in the clinical setting. British Journal of Pharmacology (2003) 140, 855,862. doi:10.1038/sj.bjp.0705517 [source] Allergens, Der p 1, Der f 1, Fel d 1 and Can f 1, in newly bought mattresses for infantsCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2002R. De Boer Summary Background To avoid allergen exposure of newborn babies, the use of a new mattress for the baby bed may be recommended. However, it is not certain that new mattresses are always free of allergens. Objective In the present study the allergen content of new infant mattresses was investigated. Methods Dust samples were vacuumed from 90 new mattresses for infant beds bought in 50 different Dutch shops, and the concentrations of Der p 1, Der f 1, Fel d 1 and Can f 1 were determined by radioimmunoassays. Results Most mattresses contained some allergen and often the allergen concentrations were surprisingly high. Only 15 of the 90 mattresses contained no detectable amounts of any of the four allergens. The highest concentration found for each allergen was 3.1, 46.5, 20.2 and 95.7 µg/g of dust, respectively. However, the total amount of allergen in a mattress was still rather low because the new mattresses contained only modest amounts of dust. Baby mattresses more often contained an increased allergen load than the larger, standard-sized, infant mattresses. This may be caused by differences in manufacturing procedure. Also, mattresses that were sold without a plastic encasement more often contained an increased allergen load. Conclusions It is advisable to buy a mattress that is wrapped in plastic, but it may still contain a substantial amount of allergen. Thorough vacuuming of a newly bought mattress before it is installed on a child's bed, is also advisable. After instalment, regular vacuuming of the mattress and washing of the bed linen as well as measures to eliminate allergen reservoirs in other parts of the house are important, because our observations indicate that mattresses easily pick up allergens from the environment. [source] | ||||||||||||||||