Integrated Pest Management Strategies for Asian Citrus Psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) and Huanglongbing in Citrus for Sarawak, East Malaysia, Borneo.

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, transmits 'Candidatus Liberibacter asiaticus' (CLas), a phloem-limited bacterium associated with the severe Asian form of huanglongbing (HLB), and the most destructive disease of citrus. The pathogen and the psyllid, both of South Asian origin, are now widespread in citrus regions of Asia and the Americas. There is no cure for the disease. Application of synthetic pesticides, in some instances more frequently than fortnightly, to minimise incidence of ACP in citrus orchards, has not prevented inevitable impacts of the disease in regions of Asia where CLas is present. Despite the inevitable spread of the disease, significant progress has been made in Sarawak since the mid-1990s towards effectively implementing integrated pest management (IPM) programs for stemming the impact of the disease and detrimental consequences of over-reliance on synthetic pesticides. Growers are encouraged to plant pathogen-free trees, remove diseased trees, monitor incidence of the psyllid, and to use pesticides judiciously to reduce their detrimental impacts on natural enemies. Knowledge has been enhanced through research on seasonal incidence of the psyllid, use of mineral oils, development of protocols and iodine−starch test kits for detecting infected trees, PCR for confirming the presence of CLas in symptomatic leaves, methods for monitoring incidence the psyllid, and training extension staff and growers. However, major impediments to increasing the average longevity of trees beyond <5 years in poorly managed orchards, based on marcotting (air layering), and >12 years in well-managed orchards, based on pathogen-free trees, still need to be addressed. These include grower knowledge, marcotting, aggressive marketing of synthetic pesticides, high prices of mineral oils, spray application procedures, and better reliance on natural enemies of the psyllid.

Effect of Horticultural Mineral Oil on Huanglongbing Transmission by Diaphorina citri Kuwayama (Hemiptera: Psyllidae) Population in a Commercial Citrus Orchard in Sarawak, Malaysia, Northern Borneo.

Diaphorina citri Kuwayama transmits a destructive citrus disease caused by a fastidious bacterium 'Candidatus Liberibacter asiaticus' (CLas) designated as Huanglongbing (HLB) which posed a risk of detrimental threat to the Malaysian citrus industry. All D. citri life stages show a lumped habit on young flushes and its population fluctuations was closely related to accessibility of young flushes. The study aimed to investigate if the appearance of young flush shoots on citrus influences ACP population fluctuation and if horticultural mineral oil (HMO) could reduce spread of HLB transmission by ACP in a commercial healthy orchard. Field research was carried out from 1 April 2011 to 1 December 2014 in a 2-year-old 1 ha citrus farm that consisted of 200 PCR-certified disease-free grafted non-bearing honey tangerine (Citrus reticulata L.) in southwestern Sarawak, Malaysia. The experiment had two treatments namely control (unsprayed) and nC24 HMO with four replications arranged in a simple randomized block design. ACP eggs, nymphs, and adults per flush shoot was assessed and HLB incidence was monitored for visual inspection of the citrus trees for the current existence of usual signs of characteristic symptoms of HLB such as yellowing shoots, leaf mottling, and corky or enlarged veins on leaves. HLB-specific primer was employed in 16S rDNA polymerase chain reaction to detect the CLas gene in diseased trees. Increase in abundance of D. citri is mainly affected by the citrus flushing cycles and their life stages are completed on these flush shoots. Relative degree of aggregation index for D. citri adults increased during periods of cyclic production of new flush. HMO-treated plots produced a significantly lower percentage up to 11.43% of diseased trees against 42.20% in untreated control plots. HMO is effective against D. citri and recommended to be incorporated in the IPM program to prevent infection and reduce the spread of HLB.

Plasmid-Mediated Antibiotic Resistant Escherichia coli in Sarawak Rivers and Aquaculture Farms, Northwest of Borneo.

BACKGROUND: The emergence of plasmid-mediated antibiotic resistance in Escherichia coli in water resources could pose a serious threat to public health. The study aims to investigate the dispersion of plasmid-mediated antibiotic-resistant E. coli from six rivers in Sarawak and two aquaculture farms in Borneo. METHODS: A total of 74 water samples were collected for the determination of their bacteria colony count. An IMViC test identified 31 E. coli isolates and tested their susceptibility against twelve clinically important antibiotics. The extraction of plasmid DNA was done using alkali lysis SDS procedures. Characteristics, including plasmid copy number, molecular weight size, resistance rate and multiple antibiotic resistance (MAR), were assessed. RESULTS: Our findings revealed that bacterial counts in rivers and aquaculture farms ranged from log 2.00 to 3.68 CFU/mL and log 1.70 to 5.48 cfu/mL, respectively. Resistance to piperacillin (100%) was observed in all E. coli; resistance to amoxicillin (100%) and ampicillin (100%) was observed in E. coli found in aquaculture farms; resistance to streptomycin (93%) was observed in E. coli found in rivers. All E. coli were resistant to ≥2 antibiotics and formed 26 MAR profiles, ranging from an index of 0.17 to 0.83, indicating that there are high risks of contamination. Some (48.4%) of the E. coli were detected with plasmids (1.2 to >10 kb), whereas 51.6% of the E. coli did not harbor any plasmids. The plasmid copy numbers reported were one plasmid (n = 7), two plasmids (n = 4), ≥ two plasmids (4). E. coli isolated from the Muara Tuang River showed the highest-molecular-weight plasmids. A statistical analysis revealed that there is no significant correlation (r = 0.21, p = 0.253) between the number of plasmids and the MAR index of the tested isolates. CONCLUSION: The distribution of MAR in E. coli from rivers is higher compared to the aquaculture environment. Our study suggests that MAR in isolates could be chromosome-mediated. Our results suggest that riverbed sediments could serve as reservoirs for MAR bacteria, including pathogens, under different climatic conditions, and their analysis could provide information for public health concerns.

Activation of the ERK1/2 signaling pathway enhances proliferation and apoptosis of trophoblast in preeclampsia rats.

OBJECTIVE: The aim of this study was to investigate the influences of the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway on preeclampsia rats as well as the proliferation and apoptosis of trophoblasts. MATERIALS AND METHODS: A proper number of conceived rats were applied to prepare the preeclampsia model (group P). Meanwhile, others were enrolled as control group (group C). The differences in placental structure between the two groups were compared via hematoxylin-eosin (HE) staining. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were compared between the two groups as well. In addition, T25 cell lines were divided into three groups, including Control group, hypoxia/reoxygenation (H/R) group and H/R + Staurosporine group (an activator of the ERK1/2 signaling pathway). The protein expression of phosphorylated (p)-ERK1/2 in the aforementioned model groups and cells was detected through Western blotting. Cell apoptosis rate was determined by a flow cytometer. Moreover, methyl thiazolyl tetrazolium was utilized to measure the proliferative capacity of trophoblasts in the three groups. Transwell chamber assay was adopted to count the transmembrane cells. RESULTS: The cells in group P were arranged disorderly. Group P had remarkably lower SOD activity but higher MDA content than group C (p<0.05). The protein expression levels of ERK1/2 and p-ERK1/2 in the placenta of group C were evidently higher than those of group P (p<0.05). Besides, the protein expression levels of ERK1/2 and p-ERK1/2 were markedly up-regulated in Control group when compared with H/R + Staurosporine group, with the lowest in H/R group (p<0.05). The proliferative capacity of cells was gradually enhanced in the three groups with the increase of culture time. Cell proliferation was the strongest in Control group, followed by H/R + Staurosporine group and H/R group (p<0.05). The apoptosis and death rates of cells were the highest in H/R group, followed by H/R + Staurosporine group and Control group (p<0.05). However, the number of transmembrane cells was the largest in Control group, followed by H/R + Staurosporine group and H/R group (p<0.05). CONCLUSIONS: The ERK1/2 signaling pathway is associated with preeclampsia in rats, whose activation can enhance cell proliferation and weaken cell apoptosis.

Nesfatin-1 alleviates acute lung injury through reducing inflammation and oxidative stress via the regulation of HMGB1.

OBJECTIVE: Acute lung injury (ALI) is the most common complication of sepsis, with rapid onset and high mortality. There is currently no effective treatment for ALI. Therefore, we looked for a good method of treating ALI by studying the effect and mechanism of Nesfatin-1 on ALI. MATERIALS AND METHODS: We used LPS to induce mouse and human alveolar epithelial cell line BEAS-2B to construct an ALI model. Recombinant Nesfatin-1 was administered subcutaneously to mice or used to stimulate BEAS-2B cells. We collected mouse bronchoalveolar lavage fluid and mouse lung tissue to detect changes in inflammatory factors and oxidative stress levels. In addition, we examined the expression changes of HMGB1 to study the mechanism of Nesfatin-1. RESULTS: Exogenous Nesfatin-1 significantly attenuated LPS-induced ALI and reduced inflammation levels and oxidative stress levels in mouse lung tissue. In cell experiments, Nesfatin-1 also reduced inflammation levels and oxidative stress levels in BEAS-2B cells. In addition, Nesfatin-1 reduced the expression of HMGB1 in mouse lung tissues and BEAS-2B cells, and decreased the activity of p38MAPK and NF-κB signaling pathways in the inflammation-related pathway downstream of HMGB1. However, after overexpression of HMGB1, the therapeutic effect of Nesfatin-1 on ALI was attenuated. CONCLUSIONS: Nesfatin-1 regulates the expression of HMGB1 in alveolar epithelial cells. By reducing the expression of HMGB1, Nesfatin-1 can reduce the inflammation-related signaling pathway downstream of HMGB1 to reduce the level of inflammation and oxidative stress in alveolar epithelial cells, thereby alleviating ALI.

Compressed SENSE single-breath-hold and free-breathing cine imaging for accelerated clinical evaluation of the left ventricle.

AIM: To assess the accuracy of compressed SENSE (CS-SENSE) cine cardiac magnetic resonance imaging (CMR) with and without breath-hold in comparison to standard cine CMR with breath-hold for the assessment of left ventricular (LV) function. MATERIALS AND METHODS: Thirty-three healthy volunteers underwent balanced turbo field-echo cine CMR with breath-hold (BTFE-BH; reference standard), single breath-hold CS-SENSE (csBTFE-BH) cine CMR, and free-breathing (FB) CS-SENSE (csBTFE-FB) cine CMR on a 3 T MRI system. All images were acquired in stacks of eight short-axis sections. Image quality was assessed and compared by the Wilcoxon matched-pairs signed-rank test. End-diastolic volume, end-systolic volume, stroke volume, ejection fraction, LV end-diastolic (LVED) mass, regional myocardial wall motion, and scan time were compared by paired t-test, linear regression, and Bland-Altman analyses. RESULTS: All techniques provided acceptable image quality (score ≥3) for LV volumetric analysis in all participants (BTFE-BH [reference standard]: 5.00±0.00; csBTFE-BH: 4.03±0.17 [p<0.001]; csBTFE-FB: 3.76±0.44 [p<0.001]), with good agreement in LV function assessment; however, there was a slight but significant underestimation of LVED mass by csBTFE-FB (csBTFE-FB: 73.63±17.31 g versus BTFE-BH [reference standard]: 75.12±18.18 g, p=0.037). All methods showed a strong correlation with quantitative regional myocardial wall motion. Acquisition times for both csBTFE-BH and csBTFE-FB were significantly shorter than that for BTFE-BH (BTFE-BH [reference standard]: 89.3±5.70 seconds; csBTFE-BH: 24.42±2.18 seconds [p<0.001]; csBTFE-FB: 22.48±1.85 seconds [p<0.001]). CONCLUSION: LV function assessment with the novel CS-SENSE cine CMR is not inferior to standard cine CMR, irrespective of BH; however, LVED mass is underestimated by csBTFE-FB.

Clostridium butyricum promotes intestinal motility by regulation of TLR2 in interstitial cells of Cajal.

OBJECTIVE: Clostridium butyricum (C. butyricum) as a probiotic has been reported to have an important role in the pathogenesis of gastrointestinal diseases. However, the effects of C. butyricum on regulation of intestinal motility of ulcerative colitis (UC) remain unclear. Our study aimed to explore the cross-regulation effect of C. butyricum and toll-like receptor 2 (TLR-2) on UC. MATERIALS AND METHODS: Interstitial cells of Cajal (ICCs) were treated by C. butyricum for 2 h, the mRNA and protein levels of TLR-2, IL-6, and IL-8 were detected by RT-qPCR and Western blot. Then, TLR2-specific small interfering RNA (si-TLR2) was transfected into ICCs, and the relative expressions of IL-6 and IL-8, SCF, cell viability, ghrelin, SP, and ET were measured by RT-qPCR, Western blot, CCK-8, and ELISA. Besides, the signal pathways of NF-κB and JNK were determined by Western blot. RESULTS: C. butyricum significantly increased TLR2, IL-6, and IL-8 expressions in ICCs. However, TLR2 silence alleviated C. butyricum-induced IL-6 and IL-8 expressions. Moreover, TLR2 silence significantly inhibited C. butyricum-induced cell viability in ICCs. Additionally, C. butyricum significantly increased SCF expression and promoted the secretion of ghrelin and SP. However, a significant reduction in the levels of SCF, ghrelin, and SP was evident in the silence of TLR2 expression. Besides, TLR2 silence reduced C. butyricum-activation NF-κB and JNK signal pathways in ICCs. CONCLUSIONS: These findings revealed that C. butyricum promoted intestinal motility by regulation of TLR2 in ICCs, which contributed to understand the molecular mechanisms of C. butyricum on UC.

Tmax is a sensitive indicator of myocardial ischaemia under adenosine stress as determined by static PET imaging: a study in a porcine model.

AIM: To evaluate Tmax, defined as the time of residual function R(t) reaching its maximum, as an indicator of myocardial ischaemia and compare its efficacy with other computed tomography perfusion (CTP) parameters. MATERIALS AND METHODS: Eight Bama miniature pigs with 50-90% left anterior descending artery stenosis underwent adenosine stress myocardial CTP and 13NNH3 position-emission tomography (PET) perfusion imaging. Tmax, myocardial blood flow (MBF), myocardial blood volume (MBV), mean transit time (MTT), and time to peak (TTP) were calculated from CTP images. PET images were evaluated as ischaemia or non-ischaemia. Using PET as a reference standard, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. Multiple comparisons of the receiver operating characteristic (ROC) curves between Tmax and other parameters were performed. The diagnostic performance of the combination of each two parameters was calculated and compared with Tmax. RESULTS: Tmax was significantly higher in ischaemic segments compared with non-ischaemic segments. Multiple comparisons of the ROCs indicated that Tmax was better than MBF or TTP but not statistically different from MBV. Tmax was superior to the combination of (MBF + MBV) but not to (MBF + TTP) or (MBV + TTP). CONCLUSION: Tmax in dynamic stress CTP provides good diagnostic accuracy for detecting myocardial ischaemia, especially in sensitivity and NPV, compared with PET method. Tmax has better performance than MBF or TTP or combination of (MBF + MBV) in diagnosing myocardial ischaemia.

Genome-wide association analysis reveals genomic regions on Chromosome 13 affecting litter size and candidate genes for uterine horn length in Erhualian pigs.

Litter size has a great impact on the profit of swine producers. Uterine development is an important determinant of reproduction efficiency and could hence affect litter size. Chinese Erhualian pig is one of the most prolific breeds in the world, even though large phenotypic variation in litter size was observed within Erhualian sows. To dissect the genetic basis of the phenotypic variation, we herein conducted genome-wide association studies for total number born and number born alive (NBA) of Erhualian sows. In total, one significant single nucleotide polymorphism (SNP) (P<1.78e-06) and 11 suggestive SNPs (P<3.57e-05) were identified on 10 chromosomes, confirming seven previously reported quantitative trait loci (QTL) and uncovering six QTL for litter size or uterus length. One locus on Sus scrofa chromosome (SSC) 13 (79.28 to 90.43 Mb) harbored a cluster of suggestive SNPs associated with multiparous NBA. The SNP (rs81447100) within this region was confirmed to be significantly (P<0.05) associated with litter size in Erhualian (n=313), Sutai (n=173) and Yorkshire (n=488) populations. Retinol binding protein 2 and retinol binding protein 1 functionally related to the development of uterus were located in a region of 2 Mb around rs81447100. Moreover, four genes related to embryo implantation and development were also detected around other significant SNPs. Taken together, our findings provide a potential marker (rs81447100) for the genetic improvement of litter size not only in Chinese Erhualian pigs but also in European commercial pig breeds like Yorkshire, and would facilitate the final identification of causative variant(s) underlying the effect of SSC13 QTL on litter size.

[The specific cytotoxicities of chimeric antigen receptor-engineered T cells on different lymphomas].

Objective: To investigate the specific cytotoxicities of the second and third generations of chimeric antigen receptor (CAR) -engineered T cells (CAR-T) on different lymphomas. Methods: CAR-Ts were prepared by lentivirus packaging and infection of T cells. CCK-8, ELISA and Lactate dehydrogenase cytotoxicity assay were applied to detect the proliferation capacity, the secretion level of inflammatory factor and the specific cytotoxicity. Flow cytometry assay showed the specific cytotoxicity and residual level of CAR-T in lymphomas of treated mice. Results: The results showed that the third generation CAR-T had greater capacity of the specific cytotoxicity and proliferation capacity than of the second generation CAR-T. But there was no prominent change of the secretion level of inflammatory factor. The specific cytotoxicity of the second generation CAR-T on highly aggressive lymphomas Raji was more prominent than in inert EHEB, but also could achieve satisfactory effect. The tumor burden in the mice injected with Raji was lower than in the mice injected with EHEB from nude mice experiment. But the residual level of CAR-T in the EHEB-injected mice was higher than in the Raji-injected ones. So the second generation CAR-T was more suitable for the treatment of indolent lymphoma. Conclusion: The second generation CD19 CAR-T could treat aggressive lymphoma in a relatively short period, while the second generation CD19 CAR-T need a longer time in vivo to achieve satisfactory curative effect on the noble lymphoma.

In Vivo Imaging of Glutamine Metabolism to the Oncometabolite 2-Hydroxyglutarate in IDH1/2 Mutant Tumors.

The oncometabolite 2-hydroxyglutarate (2-HG) is a signature biomarker in various cancers, where it accumulates as a result of mutations in isocitrate dehydrogenase (IDH). The metabolic source of 2-HG, in a wide variety of cancers, dictates both its generation and also potential therapeutic strategies, but this remains difficult to access in vivo. Here, utilizing patient-derived chondrosarcoma cells harboring endogenous mutations in IDH1 and IDH2, we report that 2-HG can be rapidly generated from glutamine in vitro. Then, using hyperpolarized magnetic resonance imaging (HP-MRI), we demonstrate that in vivo HP [1-13C] glutamine can be used to non-invasively measure glutamine-derived HP 2-HG production. This can be readily modulated utilizing a selective IDH1 inhibitor, opening the door to targeting glutamine-derived 2-HG therapeutically. Rapid rates of HP 2-HG generation in vivo further demonstrate that, in a context-dependent manner, glutamine can be a primary carbon source for 2-HG production in mutant IDH tumors.

Efficacy and Therapeutic Potential of Curcumin Against Sepsis-Induced Chronic Lung Injury in Male Albino Rats.

The present study investigates curcumin effect against sepsis-induced chronic lung injury (CLI) of male albino rats. Rats were grouped into four groups such rats undergoing a sham cecal ligature puncture (CLP), rats undergoing CLP, rats undergoing CLP and treated with saline and rats undergoing CLP and treated with curcumin (100 mg/kg bwt). After 45 days of treatment, bronchoalveolar fluid (BALF), blood and lung tissues were collected from the each animal. The total protein content, wet and dry (W/D) weight of lung tissues and some inflammatory cells in the BALF were measured. Histopathological analysis was carried out to investigate the alteration of the cellular architecture of lung tissues. Lipid peroxidation malondialdehyde (MDA), superoxide dismutase (SOD) and myeloperoxidase (MPO) levels were determined. Cytokines such as interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-a) and macrophage inhibitory factor (MIF) were measured in the BALF. Curcumin administration significantly reduced CLP-induced inflammation and pulmonary edema. Curcumin treatment is significantly reduced MPO activity, and inflammatory cell accumulation in the BALF and also protein level, MDA, SOD, and W/D ratio were significantly reduced in the lung tissues. Also, curcumin reduced the expression of IL-A, TNF-a and MIF levels in the lung tissues. Histopathological study revealed the significant reduction of CLP-induced CLI in the curcumin-treated male albino rats. Taking all these data together, it is concluded that curcumin can act as a suitable therapeutic agent against CLP-induced CLI of male albino rats.

Identification of new single nucleotide polymorphisms affecting total number born and candidate genes related to ovulation rate in Chinese Erhualian pigs.

The Chinese Erhualian pig has the highest record for litter size in the world. However, the genetic mechanism of its high prolificacy remains poorly understood. In our study, large phenotypic variations in litter size were found among Erhualian sows. Significant differences in total number born (TNB) and corpora lutea numbers were observed between sows with high and low estimated breeding values (EBVs) for TNB. To identify single nucleotide polymorphisms (SNPs) associated with TNB, a selective genomic scan was conducted on 18 sows representing the top 10% and 18 sows representing the bottom 10% of EBVs of 177 sows using Illumina Porcine SNP60 genotype data. Genome-wide fixation coefficient (FST ) values were calculated for each SNP between the high- and low-EBV groups. A total of 154 SNPs were significantly differentiated loci between the two groups. Of the top 10 highest FST SNPs, rs81399474, rs81400131 and rs81405013 on SSC8 and rs81434499 and rs81434489 on SSC 12 corresponded to previously reported QTL for litter size. The other five SNPs, rs81367039 on SSC2, rs80891106 on SSC7, rs81477883 on SSC12 and rs80938898 and rs80971725 on SSC14, appeared to be novel QTL for TNB. Significant associations between rs81399474 on SSC8 and TNB were confirmed in 313 Erhualian sows. Forty genes were identified around the top 10 highest FST SNPs, of which UCHL1, adjacent to rs81399474, and RPS6KB1 and CLTC, adjacent to rs81434499, have been reported to affect the ovulation rate in pig. The findings can advance understanding of the genetic variations in litter size of pigs.

Experimental investigation on dynamic characteristics and strengthening mechanism of laser-induced cavitation bubbles.

The dynamic features of nanosecond laser-induced cavitation bubbles near the light alloy boundary were investigated with the high-speed photography. The shock-waves and the dynamic characteristics of the cavitation bubbles generated by the laser were detected using the hydrophone. The dynamic features and strengthening mechanism of cavitation bubbles were studied. The strengthening mechanisms of cavitation bubble were discussed when the relative distance parameter γ was within the range of 0.5-2.5. It showed that the strengthening mechanisms caused by liquid jet or shock-waves depended on γ much. The research results provided a new strengthening method based on laser-induced cavitation shotless peening (CSP).

Effects of diet and stress mimicked by corticosterone administration on early postmortem muscle metabolism of broiler chickens.

Three experiments were conducted to evaluate the effects of preslaughter physiological states mimicked by long- or short-term administration of corticosterone (CORT) and dietary energy sources on muscle glycogen contents and meat quality of broiler chickens. In experiment 1, the broilers were fed a high lipid diet (LD) or a normal diet (ND) that differed in carbohydrate (3.8%) and lipid (2.5%) contents from 21 d of age. From 28 d of age onwards, 50% of the chickens in each dietary treatment were subjected to CORT treatment (30 mg/kg of diet). At 7 and 11 d after CORT supplementation, musculus pectoralis major was sampled before and immediately after slaughter and analyzed for glycogen, pH, and R-value. In experiment 2, broilers, fed with the LD or ND diet from 21 d of age were subjected to 1 single s.c. injection of CORT (4 mg/kg of BW) for 3 h to mimicked acute stress at 46 d of age. In experiment 3, broiler chickens were supplied with water supplemented with glucose (30 g/L) for 1 wk before slaughter and were then subjected to the same CORT treatment as experiment 2. Blood and muscle samples were respectively obtained before and immediately after slaughter and analyzed for plasma glucose, urate and lactic acid, and muscle variables. Plasma concentrations of glucose and urate were significantly increased by acute CORT administration, whereas the lactic acid was not changed. Neither dietary energy source nor water glucose supplementation had any influence on the plasma variables. Dietary energy source or water glucose supplementation could not alter glycogen stores in musculus pectoralis major. Breast muscle glycogen stores were increased by stress mimicked by long-term CORT administration rather than by acute treatment. Preslaughter stress reactions had no relation to the depletion of breast muscle glycogen during the initial postmortem period. The initial breast muscle pH was significantly decreased by long-term CORT administration. The result suggests that short-term upregulation of circulating CORT is not involved in the elevated drip loss induced by preslaughter stress.

Impaired development of broiler chickens by stress mimicked by corticosterone exposure.

The effects of corticosterone (CORT) administration on the development of muscular tissues of broiler chickens (Gallus gallus domesticus) fed with diets differing in lipid content were investigated. The experimental chickens were given one of two experimental diets: high lipid diet (9.9% crude fat) or control diet, from 21 d of age. At 28 d of age, half of the chickens in each dietary treatment were exposed to CORT treatment, supplemented with 30 mg CORT/kg diet for 12 days, while the other half continued to consume the former diet. The zootechnical parameters were recorded at 21, 28, 35 and 39 d, and a blood sample was obtained from 8 birds of each group, respectively. The growth performance of broiler chickens was significantly depressed by CORT administration, but not by dietary treatment. Corticosterone treatment resulted in enhanced energy expenditure. The results indicate that the development of breast muscle was more susceptible to stress mimicked by CORT administration. The results suggest that corticosterone administration enhanced hepatic fatty acid synthesis and resulted in the redistribution of energy to abdominal store from peripheral tissues. Diet rich in lipid content was favorable to the central fat deposit in stressed broiler chickens.

Thermoregulation responses of broiler chickens to humidity at different ambient temperatures. I. One week of age.

Three trials were conducted to investigate the effect of RH (35, 60, and 85%) on thermoregulation of 1-wk-old broiler chickens at different temperatures (35, 30, and 25 degrees C). The response to humidity in rectal temperature and plumage temperature at the back and breast within 24 h after exposure were recorded at 5 time points (1,4,8,16, and 24 h). Humidity affected the thermoregulation of 1-wk-old broiler chickens by redistributing heat within the body at high, low, and thermoneutral temperatures. The redistribution of heat resulted in decreased rectal temperature and increased peripheral temperature, which were, respectively, beneficial and unfavorable at high and low temperatures. These results suggested that feedback effects of surface temperature on core temperature also exist in poultry, as already observed in mammals, and could be induced not only by changed ambient temperature but also by the changes in humidity at high temperature. The disturbance of thermal equilibrium could not be established solely by changes in RT, but rather core and surface temperatures had to be considered. The daily rhythms in rectal and surface temperatures were affected by humidity.

Molecular mechanisms of survival and apoptosis in RAW 264.7 macrophages under oxidative stress.

Organisms living in an aerobic environment are continuously exposed to reactive oxygen species (ROS). Apoptosis of cells can be induced by ROS and cells also develop negative feedback mechanisms to limit ROS induced cell death. In this study, RAW264.7 murine macrophage cells were treated with H(2)O(2) and cDNA microarray technique was used to produce gene expression profiles. We found that H(2)O(2) treatment caused up-regulation of stress, survival and apoptosis related genes, and down-regulation of growth and cell cycle promoting genes. Numerous genes of metabolism pathways showed special expression patterns under oxidative stress: glycolysis and lipid synthesis related genes were down-regulated whereas the genes of lipid catabolism and protein synthesis were up-regulated. We also identified several signaling molecules as ROS-responsive, including p53, Akt, NF-kappa B, ERK, JNK, p38, PKC and INF-gamma . They played important roles in the process of apoptosis or cell survival. Finally, an interactive pathway involved in cellular response to oxidative stress was proposed to provide some insight into the molecular events of apoptosis induced by ROS and the feedback mechanisms involved in cell survival.

Study of beta-amyloid peptide (Abeta40) insertion into phospholipid membranes using monolayer technique.

beta-Amyloid peptide (Abeta), a normal constituent of neuronal and non-neuronal cells, has been proved to be the major component of extracellular plaque of Alzheimer's disease (AD). The interaction of Abeta with lipid membranes may be essential for its neurotoxicity. Our previous study revealed that membrane insertion may provide a possible pathway by which Abeta prevents itself from aggregation and fibril formation. In the present work we studied the membrane insertion of Abeta and the factors that affect its insertion ability using a monolayer approach. The results show that Abeta is surface active and can insert into lipid monolayers. When a high level of cholesterol is present, Abeta40 can insert into the phospholipid mixtures simulating physiological membrane composition. Acidic pH enhances Abeta insertion, while the effect of ionic strength is rather complex. Abeta insertion ability may be ultimately relative to cholesterol-rich domains in the monolayers, which indicates strong interaction between Abeta and cholesterol.

Specific binding of integrin alphaIIbbeta3 to RGD peptide immobilized on a nitrilotriacetic acid chip: a surface plasmon resonance study.

Nitrilotriacetic acid has been routinely used in protein purification for its high affinity for His-tagged protein in the presence of Ni2+. Here we reported a type of nitrilotriacetic acid chip (NTA-chip) prepared by transferring NTA-DOGS containing a lipid monolayer to a 50 nm thick gold layer deposited on a glass slide. The surface binding ability of His-tagged protein and regeneration of NTA chip were characterized using a synthetic polypeptide P1 (His-His-His-His-His-His-epsilon-aminohexanoic-Gly-Gly-Arg-Gly-Asp-Ser). The effect of divalent cations on integrin binding affinity for RGD ligand was investigated after P1 had been immobilized onto the sensor chip. The results show that the NTA-chip is a useful tool to immobilize His-tagged protein on the chip surface, and can provide a functional orientation for further investigation. The results also show that removing of Ca2+ bound on low affinity sites or adding of Mn2+ can increase the binding ability of integrin.