Bibliothek

Notizen: As most soil phosphates exist as insoluble inorganic phosphate and organic phosphates, higher plants have developed several strategies for adaptation to low phosphorus (P). These include the secretion of acid phosphatase and organic acids, induction of the inorganic phosphate (Pi) transporter and the substitution of some enzyme activities as alternative pathways to increase P utilization efficiency. It has been proposed that plants also have a ‘pho regulon’ system, as observed in yeast and Escherichia coli; however, the detail of the regulation system for gene expression on P status is still unclear in plants. To investigate the alteration of gene expression of rice roots grown under P-deficient conditions, a transcriptomic analysis was conducted using a cDNA microarray on rice. Based on the changes of gene expression under a –P treatment, the up-regulation of some genes due to P deficiency was confirmed . Some new important metabolic changes are suggested, namely: (1) acceleration of carbon supply for organic acid synthesis through glycolysis; (2) alteration of lipid metabolism; (3) rearrangement of compounds for cell wall; and (4) changes of gene expression related to the response for metallic elements such as Al, Fe and Zn.

Notizen: Hatchery-reared juvenile black sea bream Acanthopagrus schlegeli (Bleeker) are characterized by high lipid storage and low levels of highly unsaturated fatty acids in their bodies. In the present study, we assessed the effects of dietary fortification of the diet with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the improvement of physiological activity. Black sea bream 50 days old with an average weight of 0.02 g were reared for 50 days on either a control diet (commercial diet) or a commercial diet fortified with 3% EPA and DHA. The fortification with EPA and DHA reduced lipid storage in adipocytes in the intraperitoneal cavity, but decreased muscle lipid level. Consequently, the total lipid level decreased in the bodies of the fish. The proportions of EPA and DHA in muscle, liver and adipocytes were markedly increased by diet fortification, and the EPA and DHA proportions did not differ from those of wild fish. The cell diameter of adipocytes was reduced by EPA and DHA fortification. Liver function and resistance to air-dipping were improved by fortification. The results of a starvation test revealed the efficient mobilization of lipid reserves in response to energy demands prior to protein exhaustion in the EPA/DHA-enriched group. The results implied that increasing the incorporation of dietary EPA and/or DHA should be considered in the larval stage of black sea bream culture.

Notizen: Background Asthma exacerbations are frequently associated with rhinovirus (RV) infections. However, the contribution of airway submucosal gland (SMG) to exacerbations of asthma in RV respiratory infection has not been studied.Objective This study was undertaken to examine whether RV-infected human respiratory SMG cells produce pro-inflammatory cytokines and chemokines for eosinophils, and augment eosinophil transmigration across human airway epithelium.Methods We infected cultured human tracheal SMG cells with RV14, collected culture media at 1, 3, and 5 days after infection, and measured the chemotactic activity for eosinophils in the culture supernatant using a 48-well microchemotaxis chamber and a 51Cr-labelled eosinophil transmigration assay.Results Exposing a confluent human tracheal SMG cell monolayer to RV14 consistently led to infection. Human SMG cells with RV infection secreted soluble factors activating human eosinophil chemotaxis into the culture supernatant in a time-dependent manner, and the culture supernatant significantly augmented the transmigration of 51Cr-labelled eosinophils through human airway epithelial cell layers from the basal to mucosal side. These effects were completely abolished by a mixture of a monoclonal antibody regulated on activation, normal T cells expressed and secreted (RANTES) and an antibody to granulocyte macrophage-colony stimulating factor (GM-CSF).Conclusion These results suggest that human respiratory SMG cells may augment eosinophil transmigration across the airway epithelium through the secretion of RANTES and GM-CSF after RV infection, and may contribute to exacerbations of asthma.

Notizen: DNA damage generated by reactive oxygen species (ROS) has been implicated in ageing and in the pathogenesis of cardiovascular disease. Reactive oxygen species have also been demonstrated to play a crucial role in the pathophysiology of various renal diseases. They are extremely vulnerable to oxidative stress because mitochondria are the major intracellular source of ROS and have limited protection from oxidative stress. We have found increased accumulation of 8-hydroxy-2′-deoxyguanosine (8-OH-dG), which is a product and bio-marker of oxidative DNA damage, in the mitochondria of glomeruli and tubules in patients with IgA GN. The hOGG1 gene encodes a DNA glycosylase that excises 8-OH-dG from damaged DNA. Recently, genetic polymorphism of Ser(S)326Cys(C) has been reported. In addition, the enzymatic activity of hOGG1 in the repair of 8-OH-dG has been reported to be greater with S than with C.In this study, we investigated the correlation between hOGG1 polymorphism and the clinical phenotypes in Japanese patients with IgA GN. A total of 100 patients with IgAGN with a clinical course of over 7 years duration whose diagnosis was made by renal biopsy were divided into the ‘CRF group’ and the ‘fair group’. The CRF group consisted of 30 patients whose creatinine clearance (Ccr) had fallen to less than 50% of that during the initial period or they had developed end stage renal failure (ESRF). The fair group consisted of 62 patients whose Ccr had been kept at over 80% of that during the initial period, even 7 years after the diagnosis. The patients were genotyped and their clinical findings were compared. One hundred healthy Japanese subjects with normal urinalysis and renal function were analysed. The patients and controls were informed of the ethical approval of this study before entry into the study. The genotype of the hOGG1 gene was determined using the PCR-SSCP method followed by direct sequencing analysis. The details of PCR-SSCP methods have been previously described.1 Clinical and biochemical data were extracted from case records. Blood pressure was evaluated as the average during 1 week of the patient’s hospitalization for a first renal biopsy. Proteinuria was also evaluated as the average data obtained from 24 h collected urine samples for a week. Significant differences in allele frequency and genotype between groups were tested by χ2 test. Biochemical and clinical data were tested by ANOVA and the t-test.We found a high frequency of the C allele in the CRF group compared to the fair group and controls (P 〈 0.05, 〈link href="#t1"〉Table 1). The frequency of ESRF patients was significantly higher among the patients with the CC genotype than in those woth the CS and SS genotype (CC, CS, SS = 50%, 27%, 16%; CC vs CS, P 〈 0.05; CC vs SS, P 〈 0.01; 〈link href="#f1"〉Fig. 1).〈tabular xml:id="t1"〉1〈title type="main"〉 Genotype and allele frequencies in each group 〈mediaResource alt="image" href="urn:x-wiley:13205358:NEP7:NEP_7_t1"/〉〈figure xml:id="f1"〉1〈mediaResource alt="image" href="urn:x-wiley:13205358:NEP7:NEP_7_f1"/〉Frequency of ESRF patients in each group.The creatinine increase rate CC, CS, SS = 0.6090 ± 0.924, 0.1998 ± 0.561, 0.0766 ± 0.2558 mg/dL per year, P 〈 0.05, 〈link href="#t2"〉Table 2) and proteinuria (CC, CS, SS = 1.89 ± 2.24, 1.02 ± 1.07, 1.17 ± 1.57 (g/24 h), P 〈 0.05) were significantly higher in the patients with the C allele than in those with the S allele.〈tabular xml:id="t2"〉2〈title type="main"〉 Creatinine increase rate and proteinuria in each group 〈table frame="topbot"〉〈tgroup cols="5" align="left"〉〈colspec colnum="1" colname="col1" align="left"/〉〈colspec colnum="2" colname="col2" align="center"/〉〈colspec colnum="3" colname="col3" align="center"/〉〈colspec colnum="4" colname="col4" align="center"/〉〈colspec colnum="5" colname="col5" align="left"/〉〈thead valign="bottom"〉〈row rowsep="1"〉CCCSSS〈tbody valign="top"〉Crn increase rate0.6090 ± 0.9240.1998 ± 0.5610.0766 ± 0.2558(mg/dL per year)Proteinuria1.89 ± 2.241.02 ± 1.071.17 ± 1.57(g/24 h)〈note xml:id="t2_note4" numbered="no"〉 P 〈 0.05These findings indicate that the polymorphism of the hOGG1 gene is associated with progression of IgA GN. hOGG1 polymorphism correlates with the amount of proteinuria and a decreasing speed of renal function. In this study, the patients with the CC genotype tended to fall into ESRF. A previous study disclosed that the ability to excise 8-OH-dG is greater with the S allele than with the C allele.2 These facts suggest that accumulation of oxidative DNA damage might be an important factor in the progression of IgA GN. Excision oxidative DNA damage, which is genetically decided, may play an important role in IgA GN.

Notizen: summary  The aim of this study was to investigate the relationship between thickness of sample food and bite force. We designed a new sensor that can detect the pressure distribution between the incisor and molar teeth on one side, and the contact area between the food samples and the teeth. The force and contact area were directly measured in real time using the multiple-point sheet sensor, which is a very thin and flexible pressure-sensing device. Silicone rubber blocks were used as a sample food and were chewed with incisors and molars by 10 healthy women. The peak force, contact area, duration and impulse were greater between the incisors for a thicker specimen. The active pressure, defined as the ratio of the force to contact area, at peak was similar for different thicknesses. In contrast, with a 2 mm thick sample, the peak force and force related parameters were greatest in molar chewing. The force, contact area and duration were greater for molar chewing cycles than incisor ones. We verified that the thickness of samples influenced the chewing force of humans and the effects differed between incisors and molars.

Notizen: Background  Staphylococcus skin infection is characterized by the infiltration of numerous neutrophils within the epidermis; however, the precise mechanism of epidermal infiltration of neutrophils during skin infection with staphylococci is not well understood and the factors regulating the neutrophil recruitment are yet to be determined.Objectives  We investigated the effects of staphylococci on cytokine production from keratinocytes, specifically to elucidate the mechanisms of neutrophil infiltration within the epidermis in cutaneous microbial infection.Methods  Cytokine production from human keratinocytes was examined after stimulation with heat-killed Staphylococcus aureus, S. epidermidis and S. intermedius.Results  Interleukin (IL)-6 and IL-8 were detected in the culture supernatants by enzyme-linked immunosorbent assay but IL-1β, monocyte chemotactic protein-1 and tumour necrosis factor-α were not. IL-6 and IL-8 mRNAs were also confirmed by reverse transcription–polymerase chain reaction in the keratinocytes stimulated with killed staphylococci for 1, 3, 6, 10 and 24 h.Conclusions  These results could explain the epidermal infiltration of neutrophils in cutaneous infection with staphylococci, suggesting that the analysis of cytokines might add valuable information for the pathogenesis of cutaneous infection with Staphylococcus species.

Notizen: [Auszug] The properties of an interacting electron system depend on the electron correlations and the effective dimensionality. For example, Coulomb repulsion between electrons may inhibit, or completely block, conduction by intersite electron hopping, thereby determining ...

Notizen: Summary A method was devised to obtain a correct surface tension vs. equilibrium concentration curve for a very dilute solution of surface active substance, such as sodium dodecyl sulfate dissolved in an aqueous solution of saturated ammonium sulfate, where the decrease of the bulk concentration due to the adsorption is not negligible. Adsorption isotherm was obtained by applyingGibbs adsorption equation to the curve, and the pressure vs. area curve was plotted. The latter plot is in agreement with that directly measured for the spread film on saturated ammonium sulfate solution, the surface pressure of which was obtained by the extrapolation to time zero of the plot of log surface pressure vs. square root of time. The amount of calculated saturation value is in agreement with that directly measured by the radiotracer method. These agreements show the validity of the present method of obtaining surface tension and adsorption isotherms, together with the method of extrapolation to obtain the surface pressure vs. area curve for soluble film.

Notizen: Abstract: We report low-temperature measurements 0.07 K ? T ? 2 K of the specific heat, C, of the perovskite superconductor Sr2RuO4. Based on a detailed analysis of our data with respect to both sample quality (as measured by T c = 0.43 K - 1.17 K) and magnetic-field dependence, it is shown that the electronic contribution to the specific heat, which contains the desired information on the gap structure, is superimposed by at least two additional contributions: a Schottky-type hump at T ≈ 0.1 - 0.2 K and a low-temperature upturn in C / T at T 〈 0.1 K. We discuss possible origins of these additional contributions and their implications for the interpretation of low-temperature C ( T ) data.