Immunohistochemical localization of the progesterone and oestrogen receptors in the shell gland of sexually immature ostriches (Struthio camelus) with active or inactive ovaries

The immunohistochemical localization of progesterone and oestrogen receptors was studied in the shell gland of the immature ostrich (Struthio camelus) during periods of ovarian activity and inactivity. In birds with active ovaries moderate to strong immunostaining for the progesterone receptor was observed in the surface epithelium and tubular glands. In contrast faint progesterone receptor immunostaining was observed in the surface epithelium of the shell gland in ostriches with inactive ovaries. In addition, bud-like invaginations of the surface epithelium, which signaled tubular gland development, were negative for the progesterone receptor. Oestrogen receptor immunostaining, which was seen only in birds with active ovaries, was weak and restricted to nuclei of the surface epithelium. These results suggest that steroid hormones secreted by the active ovary regulate the differentiation of the shell gland. Furthermore, the influence of these hormones on the shell gland appears to be mediated predominantly through the activation of the progesterone receptor.     

Ultrastructural features of atretic follicles in the sexually immature ostrich (Struthio camelus)

The aim of this study was to describe the ultrastructural features of atresia in follicles of the immature ostrich (12–14 months old); a ratite that displays seasonal, precocious ovarian activity. The early stage of atresia in primordial, pre-vitellogenic and vitellogenic follicles was characterized by the accumulation of lipid droplets in the granulosa cells. Granulosa cells with condensed cytoplasm and nuclei were a prominent feature during the intermediate phase of atresia. The degenerating follicles were then infiltrated by stroma during the terminal stages of atresia. The results of this study provide further information on the morphology of atretic ovarian follicles in the immature ostrich.     

Epidemiology of Bartonella Infection in Rodents and Shrews in Taiwan

During the period of August 2002 and November 2004, an epidemiological investigation for Bartonella infection was conducted in small mammals in Taiwan. Using whole blood culture on chocolate agar plates, Bartonella species were successfully isolated from 41.3% of the 310 animals tested. The isolation rate of Bartonella species varied among different animal species, including 52.7% of the 169 Rattus norvegicus, 28.6% of the 126 Sucus murinus, 10% of the 10 Rattus rattus and 66.7% of the three Rattus losea. Bacteremia prevalence also varied with the origin of the animals, as 56.2% of the animals captured on farms, 38.6% of the ones captured at harbour sites and 11.8% of the animals captured from urban areas were bacteremic. Through molecular analysis of the gltA gene and 16S/23S intergenic spacer region, genetic diversity of Bartonella organisms was identified, including strains closely related to Bartonella tribocorum, Bartonella grahamii, Bartonella elizabethae, Bartonella phoceensis and Bartonella rattimassiliensis. Moreover, this is the first report of zoonotic B. elizabethae and B. grahamii identified in R. losea, the lesser rice‐field rat. Various Bartonella species were identified in R. norvegicus, compared to 97.2% of Suncus murinus with unique Bartonella species. By indirect immunofluorescence antibody test, using various rodent Bartonella species as antigens, consistently low percentage of seropositivity implied that small mammals may play a role as competent reservoirs of Bartonella species in Taiwan. Future studies need to be conducted to determine whether these Bartonella species would be responsible for human cases of unknown fever or febrile illness in Taiwan, especially zoonotic B. elizabethae and B. grahamii.     

Online RP-HPLC-DPPH screening method for detection of radical-scavenging phytochemicals from flowers of Acacia confusa

Acacia confusa is traditionally used as a medicinal plant in Taiwan. In this study, phytochemicals and antioxidant activities of extracts from flowers of A. confusa were investigated for the first time. In addition, a rapid screening method, online RP-HPLC-DPPH system, for individual antioxidants in complex matrices was developed. Accordingly, six antioxidants including gallic acid ( 1), myricetin 3-rhamnoside ( 2), quercetin 3-rhamnoside ( 3), kaempferol 3-rhamnoside ( 4), europetin 3-rhamnoside ( 5), and rhamnetin 3-rhamnoside ( 6) were detected using the developed screening method. Of these, compounds 2, 3, and 5 were found to be major bioactive phytochemicals, and their contents were determined as 11.3, 6.7, and 8.7 mg/g of crude extract, respectively. By comparison with quercetin, a well-known antioxidant, these compounds had the order of compound 2 > compound 5 > quercetin > compound 3 for DPPH radical-scavenging activity. Their IC 50 values were 3.0, 3.2, 4.5, and 7.4 microM, respectively. Moreover, the same order was observed for superoxide radical-scavenging activity, and their IC50 values were 2.6, 2.7, 4.3, and 5.3 microM, respectively. However, for lipid peroxidation, quercetin, an aglycon, showed the best inhibitory activity. The IC50 values of quercetin, compound 2, compound 5, and compound 3 were 46.7, 88.5, 90.7, and 124.6 microM, respectively. These results indicated that a rhamnoside at the C3 position of flavonoids had a negative effect on radical-scavenging activity and antilipid peroxidation. In contrast, the number of hydroxyl groups on the B-ring exhibited a positive relationship with their inhibitory activities.     

Genetic variation of highly pathogenic H5N1 avian influenza viruses in Vietnam shows both species-specific and spatiotemporal associations

Domestic poultry act as a reservoir for persistent H5N1 endemicity in Vietnam, and the circulation of poultry flocks across farms and to market is thought to drive the spatial movement and evolution of avian influenza viruses. Using a dataset of complete or nearly full genomic sequences from highly pathogenic H5N1 avian influenza viruses collected in domestic poultry in Vietnam from 2003 to 2007, we explore potential differences in genetic characteristics according to species of isolation and the spatiotemporal characteristics of the viruses. Clustering algorithms and ANOVA indicate that H5N1 viruses in Vietnam show differences in the amount of genetic change that chicken viruses experience as compared to duck viruses, with duck viruses showing higher rates of molecular evolution on all eight of influenza's gene segments. There also exist distinct patterns of genetic differentiation according to the year in which they were isolated. These findings suggest that genetic evolution of avian influenza viruses is continuous through time but could also be mediated by the species in which the viruses occur, information that has implications for prevention efforts.     

In Vitro Suppression of Growth of Murine WEHI-3 Leukemia Cells and in Vivo Promotion of Phagocytosis in a Leukemia Mice Model by Indole-3-carbinol

Indole-3-carbinol (I3C), a potential anticancer substance, can be found in cruciferous (cabbage family) vegetables, mainly cauliflower and Chinese cabbage. However, the bioactivity of I3C on the apoptotic effects of murine leukemia WEHI-3 cells and promotion of immune responses in leukemia mice model are unclear. In this study, we investigated the effect of I3C on cell-cycle arrest and apoptosis in vitro and immunomodulation in vivo. I3C decreased the viable WEHI-3 cells and caused morphological changes in a concentration- and time-dependent manner. I3C also led to G0/G1 phase arrest, decreased the levels of cyclin A, cyclin D, and CDK2, and increased the level of p21(WAF1/CIP1). Flow cytometric analyses further proved that I3C promoted ROS and intracellular Ca(2+) production and decreased the levels of ΔΨ(m) in WEHI-3 cells. Cells after exposure to I3C for 24 h showed DNA fragmentation and chromatin condensation. Comet assay also indicated that I3C induced DNA damage in examined cells. I3C increased the levels of cytochrome c, FADD, GADD153, GRP78, and caspase-12 as well as induced activities of caspase-3, -8, and -9. Moreover, I3C attenuated NF-κB DNA binding activity in I3C-treated WEHI-3 cells as shown by EMSA and Western blotting analyses. In the in vivo study, we examined the effects of I3C on WEHI-3 leukemia mice. Results showed that I3C increased the level of T cells and decreased the level of macrophages. I3C also reduced the weights of liver and spleen, and it promoted phagocytosis by macrophages as compared to the nontreated leukemia mice group. On the basis of our results, I3C affects murine leukemia WEHI-3 cells both in vitro and in vivo.     

Observation of quantum criticality with ultracold atoms in optical lattices

Quantum criticality emerges when a many-body system is in the proximity of a continuous phase transition that is driven by quantum fluctuations. In the quantum critical regime, exotic, yet universal properties are anticipated; ultracold atoms provide a clean system to test these predictions. We report the observation of quantum criticality with two-dimensional Bose gases in optical lattices. On the basis of in situ density measurements, we observe scaling behavior of the equation of state at low temperatures, locate the quantum critical point, and constrain the critical exponents. We observe a finite critical entropy per particle that carries a weak dependence on the atomic interaction strength. Our experiment provides a prototypical method to study quantum criticality with ultracold atoms.     

A procedure to estimate cover coefficient and parameters of soil moisture stress function using soil moisture monitoring data

A procedure to determine soil moisture threshold (θ*), cover coefficient (k _c), and parameters of soil moisture stress function (k _s) is proposed in this study. These coefficients can be further applied to estimate daily actual evapotranspiration in a hydrological model. Two soil moisture stress functions are used to describe k _s. One of the functions is proposed by this study, which assumes moisture stress is inversely proportional to matric potential described by van Genuchten retention curve. The procedure is applied to identify the coefficients for three kinds of reference potential evapotranspiration based on soil moisture monitoring. Soil moisture was measured by Watermark soil moisture sensors. These sensors were tested in a laboratory to establish the relationship between soil moisture and recorded tensor. Then, these sensors were installed in an experimental forest watershed. The verification study shows that the calibrated coefficients can provide reasonable estimate of actual evapotranspiration. The R ² = 0.85 for using the Penman–Montieth equation for tall maize along with k _c = 1.81 can be obtained for the validation period with soil moisture stress. Besides, the results also indicate the proposed soil moisture stress function can have better performance on estimating daily actual evapotranspiration at early stage of a dry period. The proposed procedure and soil moisture stress functions can be successfully applied to estimate daily evapotranspiration when soil moisture is known. However, their performance in a hydrological model requires further study, since a hydrological model can only provide estimated soil moisture.     

Phytotoxicity of Sunflower Residues against Some Summer Season Crops

The growth of four summer season crops, namely Cyamopsis tetragonoloba , Sorghum vulgare , Pennisetum americanum and Zea mays , in fields with or without residues of the preceding sunflower crop was poor. Crop density, weight of seed or grain and total yield were significantly lower in sunflower fields than in the control fields (i.e. those without previous sunflower crops). Growth in terms of plant height and biomass was drastically reduced after 60 days. The effect was more pronounced in the fields where sunflower residues were allowed to decompose than in those where residues were completely removed. The soil collected from sunflower fields (both with and without residues) was found to be rich in phenolics, which in a laboratory bioassay were found to be phytotoxic. The reduced growth and yield of crops can be attributed to the release of phytotoxic phenolics from decomposing sunflower residues.