Dietary supplementation with <Emphasis Type="Italic">Astragalus</Emphasis> polysaccharide enhances ileal digestibilities and serum concentrations of amino acids in early weaned piglets

Two experiments were conducted to evaluate the effects of dietary supplementation with Astragalus polysaccharide (APS) on growth performance, apparent ileal digestibilities (AID) of amino acids (AA), and their serum concentrations in early weaned piglets. In Exp. 1, 60 pigs were weaned at 21 days of age (BW 7.35 ± 0.23 kg) and allocated to three treatments (20 pigs/treatment), representing supplementing 0.0% (control), 0.02% colistin (antibiotic), or 0.1% APS to a corn- and soybean meal-based diet. Average daily gain (ADG), average daily feed intake (ADFI), and feed/gain ratio (F/G) were measured weekly. Blood samples were obtained from five pigs selected randomly from each treatment for the measurement of serum free AA concentrations on days 7, 14, and 28. In Exp. 2, 12 pigs were weaned at 21 day of age (BW 7.64 ± 0.71 kg), assigned to three treatment groups as in Exp. 1, and surgically fitted with a simple T-cannula at the terminal ileum. Ileal digesta samples were obtained for the measurement of AID of AA on days 7, 14 and 28. Dietary APS did not affect ADFI, but enhanced (P < 0.05) ADG by 11 and 4.4%, and improved F/G by 5.6 and 8.4%, respectively, compared with the control and antibiotic groups. Addition of APS to the diet increased AID and serum concentrations of most nutritionally essential and non-essential AA (including arginine, proline, glutamate, lysine, methionine, tryptophan, and threonine) on days 14 and 28. Circulating levels of total AA were affected by the age of pigs and treatment × time interaction. Collectively, these findings indicate that APS may ameliorate the digestive and absorptive function and regulate AA metabolism to beneficially increase the entry of dietary AA into the systemic circulation, which provide a mechanism to explain the growth-promoting effect of APS in early weaned piglets.     

Dietary supplementation with Chinese herbal powder enhances ileal digestibilities and serum concentrations of amino acids in young pigs

This study was designed to determine the effect of ultra-fine Chinese herbal powder as a dietary additive on serum concentrations and apparent ileal digestibilities (AID) of amino acids (AA) in young pigs. In Experiment 1, 60 Duroc x Landrace x Yorkshire piglets weaned at 21 days of age were randomly assigned to one of three treatments, representing supplementation with 0 or 2 g/kg of the powder, or 0.2 g/kg of colistin (an antibiotic) to corn- and soybean meal-based diets (n = 20 per group). Blood samples from five piglets per group were collected on days 7, 14, and 28 to determine serum AA concentrations. In Experiment 2, 12 barrows with an average initial body weight of 7.64 kg were randomly assigned to one of the three dietary treatments, followed by surgical placement of a simple T-cannula at the terminal ileum. All of the diets contained 0.1% titanium oxide as a digestibility marker. The samples of terminal ileal digesta were collected on day 7 for determining AID of AA. Results show that dietary supplementation with the herbal powder increased (P < 0.05) serum concentrations and AID of most AA by 10-50% and 10-16%, respectively. As an indicator of improved intestinal function, AID values of calcium were also enhanced in piglets supplemented with the herbal powder. Dietary supplementation of colistin increased serum concentrations and AID values of some AA by 8-44% and 10-15%, respectively, in comparison with the non-supplemented group. These novel findings demonstrate that the herbal powder can enhance the digestibility of dietary protein and the intestinal absorption of AA into the systemic circulation in post-weaning pigs, therefore providing a new mechanism for its growth- and immunity-promoting efficacy.     

Remediation of chromite ore processing residue by pyrolysis process with sewage sludge

The present work developed a novel technique to treat chromite ore processing residue (COPR). The process involved mixing the COPR with sewage sludge followed by pyrolysis. The gaseous organic fraction generated during pyrolysis of sludge was beneficial to Cr(VI) reduction. Process variables, such as the amount of sludge added to COPR (sludge-to-COPR (S/C) ratio), heating temperature, reaction time and particle size, were systematically varied, and their influences on the Cr(VI) reduction in COPR were investigated. Cr(VI) content had decreased greatly, from 3384 mg kg⁻¹ for untreated COPR to less than 30 mg kg⁻¹ for COPR treated at 600 °C.     

The WRKY6 Transcription Factor Modulates PHOSPHATE1 Expression in Response to Low Pi Stress in Arabidopsis

Arabidopsis thaliana WRKY family comprises 74 members and some of them are involved in plant responses to biotic and abiotic stresses. This study demonstrated that WRKY6 is involved in Arabidopsis responses to low-Pi stress through regulating PHOSPHATE1 (PHO1) expression. WRKY6 overexpression lines, similar to the pho1 mutant, were more sensitive to low Pi stress and had lower Pi contents in shoots compared with wild-type seedlings and the wrky6-1 mutant. Immunoprecipitation assays demonstrated that WRKY6 can bind to two W-boxes of the PHO1 promoter. RNA gel blot and β-glucuronidase activity assays showed that PHO1 expression was repressed in WRKY6-overexpressing lines and enhanced in the wrky6-1 mutant. Low Pi treatment reduced WRKY6 binding to the PHO1 promoter, which indicates that PHO1 regulation by WRKY6 is Pi dependent and that low Pi treatment may release inhibition of PHO1 expression. Protein gel blot analysis showed that the decrease in WRKY6 protein induced by low Pi treatment was inhibited by a 26S proteosome inhibitor, MG132, suggesting that low Pi–induced release of PHO1 repression may result from 26S proteosome–mediated proteolysis. In addition, WRKY42 also showed binding to W-boxes of the PHO1 promoter and repressed PHO1 expression. Our results demonstrate that WRKY6 and WRKY42 are involved in Arabidopsis responses to low Pi stress by regulation of PHO1 expression.     

Delivery of Human Immunodeficiency Virus Vaccine Vectors to the Intestine Induces Enhanced Mucosal Cellular Immunity

Effective vaccines for human immunodeficiency virus type 1 (HIV-1) will likely need to stimulate protective immunity in the intestinal mucosa, where HIV-1 infection causes severe CD4⁺ T-cell depletion. While replication-competent recombinant adenovirus (rAd) vectors can stimulate adenovirus-specific mucosal immunity after replication, oral delivery of replication-defective rAd vectors encoding specific immunogens has proven challenging. In this study, we have systematically identified barriers to effective gut delivery of rAd vectors and identified sites and strategies to induce potent cellular and humoral immunity. Vector-mediated gene transfer by rAd5 was susceptible to low-pH buffer, gastric and pancreatic proteases, and extracellular mucins. Using ex vivo organ explants, we found that transduction with rAd5 was highest in the ileum and colon among all intestinal segments. Transgene expression was 100-fold higher after direct surgical introduction into the ileum than after oral gavage, with rAd5 showing greater potency than the rAd35 or the rAd41 vector. A single immunization of rAd5 encoding HIV-1 gp140B to the ileum stimulated potent CD8⁺ T-cell responses in the intestinal and systemic compartments, and these responses were further enhanced by intramuscular rAd5 boosting. These studies suggest that induction of primary immune responses by rAd5 gut immunization and subsequent systemic boosting elicits potent antigen-specific gut mucosal responses.Human immunodeficiency virus type 1 (HIV-1) infection is characterized by uncontrolled virus replication and cytopathicity in the intestinal mucosa, the site of major T-cell depletion after primary infection. The gastrointestinal (GI) tract is the predominant site of a pronounced CD4⁺ T-cell loss in the early stages of HIV infection and simian immunodeficiency virus (SIV) infection in the nonhuman primate model (3, 23, 26, 43). It has been suggested that a mucosal vaccine which generates HIV-specific CD8⁺ T cells in the gut could prevent the loss of CD4⁺ cells in gut-associated lymphoid tissue, establishment of infection, or spread of virus (13, 34). Therefore, targeted delivery of vaccines to the GI tract to stimulate mucosal responses has the potential to improve the efficacy of immune protection against HIV-1; however, the site of gene-based transduction and the barriers to vaccine delivery have not been well defined.Adenoviruses (Ads) have been used extensively as vectors for both gene transfer and vaccine development. They offer several advantages as tools for vaccine delivery, such as the ability to transduce both dividing and nondividing cells, relative safety and stability in vivo, ease of production in high titers, and lack of integration (2, 35). These vectors are promising because parenteral administration in both animals and humans has been shown to generate strong and long-lasting humoral and cellular immune responses. The immune responses surpass those achieved with other types of gene vectors and genetic vaccines (5, 38, 46). As a result, recombinant Ad (rAd) vectors have been developed and tested as vaccine vehicles to immunize against a number of pathogens (4, 10, 15, 18, 41).Orally (p.o.) delivered vaccines are attractive in theory because of their ease of administration and potential to deliver antigen to gut-associated lymphoid tissue, permitting induction of immune responses in both mucosal and systemic compartments. At the same time, p.o. delivery of replication-defective rAd vectors has posed a challenge and has met with variable levels of success. Immunization with rAd5 encoding rabies virus antigens, influenza virus antigens, or other antigens has generated some protection against infection in animal models (9, 27, 31, 39, 41), but p.o. immunization has elicited much lower CD8⁺ T-cell responses than systemic delivery (33), and a much higher dose is required to induce immune responses (37). We have recently shown in an HIV vaccine model that rAd41, a human enteric Ad-based vector, induced potent CD8⁺ T-cell responses in both systemic and mucosal compartments when primed p.o. or in the ileum (17). The previous study showed that rAd41 vectors delivered through direct ileal injection elicited mucosal cell immunity, but whether other rAd vectors could stimulate these responses and which factors affected delivery and immunogenicity were unknown. In this report, we have investigated the mechanisms associated with the low immunogenicity of rAd5 dosed through the p.o. route in mice. The purpose was to identify barriers to effective delivery of rAd vectors to gut tissues and to ascertain sites and strategies for induction of potent cellular and humoral immunity. To investigate the mechanism of the low immunogenicity of rAd vectors through the p.o. route and develop effective delivery of rAd5 and rare serotype rAd35 vectors as gut mucosal HIV vaccines, we have analyzed the obstacles to p.o. immunization, characterized vector transgene expression, and systematically compared immune responses induced by p.o. and local immunization strategies. These studies demonstrated that the higher immune responses were strongly associated with higher gene expression in the intestine and support further study of gut mucosal immunization in SIV challenge models as a potential HIV vaccine strategy.     

Purification of aquarium water by PVA gel-immobilized photosynthetic bacteria during goldfish rearing

This study was conducted to evaluate the ability of a PVA-gel beads filtration (PVA) system using photosynthetic bacteria to purify water. To accomplish this, duplicate long-term goldfish rearing experiments were conducted using four different types of aquarium systems (COF, PSB, EMC, and PVA). The results revealed that the concentrations of NH₄ ⁺-N on the day of a goldfish’s death were significantly higher than the concentrations on other days for all the aquarium systems. In addition, the mean concentration of NH₄ ⁺-N during goldfish rearing occurred in the following order: COF system > EMC system > PSB system > PVA system. Furthermore, the mean values of all other ion concentrations (NO₃ ⁻-N, NO₂ ⁻-N, and PO₄ ²⁻-P) were found to be lowest in the PVA system. As a result, there was more prominent decomposition of organic matter in the aquarium tank containing the PVA system, as well as less turbid aquarium water and more active goldfish. Additionally, the PVA-gel beads resulted in almost complete denitrification, even after six-months of goldfish rearing. To our knowledge, this is the first study to report that PVA gel-immobilized photosynthetic bacteria have the ability to purify water. Overall, the results of this study indicate that this immobilized photosynthetic bacteria system has the potential for use as a component in circulating filtration systems.     

NGFI-B targets mitochondria and induces cardiomyocyte apoptosis in restraint-stressed rats by mediating energy metabolism disorder

NGFI-B/Nur77/TR3, originally identified as an immediate-early gene rapidly induced by serum and growth factors, is a member of the steroid hormone nuclear receptor superfamily with no identified endogenous ligand. NGFI-B induces apoptosis in a number of cell lineages exposed to proapoptotic stimuli by directly targeting the mitochondria, inducing cytochrome c release. The present study was designed to determine the role of NGFI-B in cardiomyocytes of restraint-stressed rats. The NGFI-B content was increased in mitochondria and reduced in plasma as apoptosis increased. Analysis showed that NGFI-B induces cardiomyocyte apoptosis in restraint-stressed rats by mediating mitochondrial energy metabolism disorder. Several novel mitochondrial proteins, which correlate with NGFI-B, were reported in cardiomyocyte apoptosis of restraint-stressed rats. Five proteins associated with NGFI-B participate directly in mitochondrial energy metabolism. Studies of mitochondrial respiratory efficiency and ATP synthase activity strongly support the findings. These results provide significant information for comprehensively understanding the cellular mechanism of cardiovascular diseases.