[Advanced progress of ex vivo biosensor assay in toxicological evaluation].

The ex vivo biosensor assay is developed to assess the health effects and toxicological mechanism of environmental pollutants with internal environment homeostasis changes by integrating the in vivo exposure evaluation, in vitro outcomes analysis, and systematic environment component screening. This toxicology testing model combines the real-world exposure of people in the field and the study of molecular mechanism exploration in lab experiments to overcome the shortcomings of a single toxicology method. It provides a new technique and perspective for toxicity testing and risk assessment in mesoscale between macroscopic population study and microscopic mechanism exploration.

Establishment of a novel, eco-friendly transgenic pig model using porcine pancreatic amylase promoter-driven fungal cellulase transgenes.

Competition between humans and livestock for cereal and legume grains makes it challenging to provide economical feeds to livestock animals. Recent increases in corn and soybean prices have had a significant impact on the cost of feed for pig producers. The utilization of byproducts and alternative ingredients in pig diets has the potential to reduce feed costs. Moreover, unlike ruminants, pigs have limited ability to utilize diets with high fiber content because they lack endogenous enzymes capable of breaking down nonstarch polysaccharides into simple sugars. Here, we investigated the feasibility of a transgenic strategy in which expression of the fungal cellulase transgene was driven by the porcine pancreatic amylase promoter in pigs. A 2,488 bp 5'-flanking region of the porcine pancreatic amylase gene was cloned by the genomic walking technique, and its structural features were characterized. Using GFP as a reporter, we found that this region contained promoter activity and had the potential to control heterologous gene expression. Transgenic pigs were generated by pronuclear microinjection. Founders and offspring were identified by PCR and Southern blot analyses. Cellulase mRNA and protein showed tissue-specific expression in the pancreas of F1 generation pigs. Cellulolytic enzyme activity was also identified in the pancreas of transgenic pigs. These results demonstrated the establishment of a tissue-specific promoter of the porcine pancreatic amylase gene. Transgenic pigs expressing exogenous cellulase may represent a way to increase the intake of low-cost, fiber-rich feeds.

A Drug Repurposing Approach Reveals Targetable Epigenetic Pathways in Plasmodium vivax Hypnozoites.

Radical cure of Plasmodium vivax malaria must include elimination of quiescent 'hypnozoite' forms in the liver; however, the only FDA-approved treatments are contraindicated in many vulnerable populations. To identify new drugs and drug targets for hypnozoites, we screened the Repurposing, Focused Rescue, and Accelerated Medchem (ReFRAME) library and a collection of epigenetic inhibitors against P. vivax liver stages. From both libraries, we identified inhibitors targeting epigenetics pathways as selectively active against P. vivax and P. cynomolgi hypnozoites. These include DNA methyltransferase (DNMT) inhibitors as well as several inhibitors targeting histone post-translational modifications. Immunofluorescence staining of Plasmodium liver forms showed strong nuclear 5-methylcystosine signal, indicating liver stage parasite DNA is methylated. Using bisulfite sequencing, we mapped genomic DNA methylation in sporozoites, revealing DNA methylation signals in most coding genes. We also demonstrated that methylation level in proximal promoter regions as well as in the first exon of the genes may affect, at least partially, gene expression in P. vivax. The importance of selective inhibitors targeting epigenetic features on hypnozoites was validated using MMV019721, an acetyl-CoA synthetase inhibitor that affects histone acetylation and was previously reported as active against P. falciparum blood stages. In summary, our data indicate that several epigenetic mechanisms are likely modulating hypnozoite formation or persistence and provide an avenue for the discovery and development of improved radical cure antimalarials.

Characterization of hTERT-immortalized caprine mammary epithelial cells.

The aim of this article is to demonstrate and characterize caprine mammary epithelial cells (CMC) immortalized with human telomerase reverse transcriptase (hTERT) gene. Five immortalized CMCs were assigned to either myoepithelial or luminal epithelial groups based on their morphology and expression of cell lineage-specific intermediate filaments. Telomeric repeat amplification protocol revealed various telomerase activities in CMCs associated with their distinct proliferation potential. Karyotypic analysis showed three CMCs retained their modal Capra hircus chromosome number (2n = 60), whereas the remaining two CMCs were abnormal at 2n = 19 and 2n = 36. CMCs with abnormal karyotypes lost p53 protein after chemical-induced DNA damage and showed anchorage-independent growth in soft agar assay. In terms of functional differentiation, luminal CMCs organized into alveolus-like structures when grown in Matrigel. Furthermore, αs1- and ß-casein gene was induced in luminal CMCs in response to lacto-hormones stimulation. Together these results showed that hTERT-immortalized CMCs retained major characteristics of mammary epithelial cells, and stability of the genome is required for maintaining normal mammary epithelium function. Application of CMCs can provide valuable models to study alveologenesis and lactogenesis of mammary epithelium and test the feasibility of recombinant constructs designed for the generation of transgenic livestock.

Differential gene expression between the porcine morula and blastocyst.

The survival and development of pre-implantation embryos are determinant factors affecting the outcome of animal reproduction. It is essential to transfer the expression of the genetic material from maternal sources, that is the ovum to the zygote before implantation to ensure successful development. Differentiation and transformation of blastomeres initiated during the morula and blastocyst stages is an important step of the embryonic development prior to implantation. We collected morula and early blastocyst samples from pure-bred Landrace pigs in vivo to study the differential gene expression patterns at these two stages. Total RNA was extracted from individual embryos and two rounds of amplification were employed. Two micrograms of antisense RNA, targets, were prepared and hybridized with each of four custom made oligo microarrays representing 24,000 porcine genes. The analyses of replicate hybridizations showed that among the 24,000 genes, 162 genes were expressed fivefold or greater in the morula compared to early blastocysts and 2126 genes were expressed fivefold or greater in early blastocysts compared to the morula. Of these differentially expressed genes, 1429 genes were functionally annotated with related human Gene Ontology terms. In addition to basic metabolic processes, genes related to signal transduction, transportation and cell differentiation were found in both stages and were up-regulated as embryo development proceeded. Real time polymerase chain reaction was utilized to quantify 12 genes differentially expressed in the 2 embryonic stages and validated the reliability of major evidences shown in microarrays. In conclusion, we have obtained a preliminary landscape of genes differentially expressed during the transition from morula to early blastocysts in pigs and showed a generally increased transcriptional activity, perhaps in preparation for implantation. Our results provide an opportunity to study the functions of these genes in relation to the development and survival of pre-implantation porcine embryos.

Human coronavirus NL63 in children: epidemiology, disease spectrum, and genetic diversity.

1. Human coronaviruses (HCoVs)were detected in 2.5% of 2982 local children hospitalised for acute respiratory infections in 2005 to 2007. 2. Using the 'pancoronavirus' reverse transcription-polymerase chain reaction assay, detection rates were 0.6% for HCoVNL63,1.2% for HCoV-OC43,0.5% for HCoV-HKU1, and 0.2% for HCoV-229E. Notably, HCoV-NL63 infections were significantly more common among children hospitalised in 2006/2007 (1.2%) than in 2005/2006 (0.3%).3. The peak season for HCoVNL63 infection was autumn(September to October). 4. HCoV-NL63 infection was associated with younger age,croup, febrile convulsion, and acute gastroenteritis. Such disease associations were not found with the other three HCoVs. 5. Most local HCoV-NL63 isolates were closely related to the prototype strain in Netherlands(NL496), but a few were phylogenetically distinct from the major cluster.

Characterization of yeasts colonizing in healthy individuals.

Opportunistic yeast pathogens may switch from harmless commensal to pathogenic relationships with the host under different conditions. They usually cause superficial infections, but may be the agents of more significant infections in immunocompromised patients. To investigate yeast colonization in the oral cavities of clinically healthy individuals, we collected oral swabs from 323 students and staff at the National Health Research Institutes, Taiwan. A total of 49 (15.2%) volunteers were colonized by low levels of yeasts and of these, only 3 (6.1%) were co-colonized by more than one species. Among the 52 isolates, comprising seven fungal genera and 13 species, Candida albicans (57.7%) was the dominant species, followed by Candida parapsilosis (15.4%). There was only one isolate of C. parapsilosis that showed, in vitro, a high (2 µg/ml) minimum inhibitory concentration (MIC) to amphotericin B. There were six (11.5%) isolates with fluconazole MICs ≥ 64 µg/ml and all of them were non-Candida species. With the exception of Cryptococcus albidus, the remaining five isolates had voriconazole MICs ≥ 4 µg/ml. In addition, there was one C. albicans isolate with relatively high fluconazole (32 µg/ml) and voriconazole (4 µg/ml) MICs.

Feasibility assessment of a tunnel-ventilated, water-padded barn on alleviation of heat stress for lactating Holstein cows in a humid area.

The use of evaporative cooling for mitigating heat stress in lactating cows in humid areas is controversial. In Taiwan, Holstein cow performance is significantly restricted by hot and humid weather. This study investigated the efficacy of using a tunnel-ventilated, water-padded freestall (TP) barn for reducing heat stress in lactating cows. From August to October 2006, 36 cows allocated in a 3×3 Latin square were raised in 3 barn cooling treatments: a conventional freestall barn with fans and sprinklers in the feed line (Fan+SP, control), a TP barn, and a TP barn with sprinkler cooling (TP+SP). Daytime air speeds in the 3 barns were 1.23, 2.38, and 2.06 m/s, respectively. Both TP barns were more efficient than the control in reducing the daytime temperature and temperature-humidity index. The barn temperature was <26°C for an extra 4.2h per day, but the relative humidity was >96% in both TP barns. Cows in both TP barns had higher respiration rates and skin temperatures at 0300 h than cows in the Fan+SP barn. The TP environment increased the cows' serum cholesterol level and the activities of alkaline phosphatase and alanine aminotransferase, but blood partial pressure of CO(2) was not affected. Vaginal temperature was persistently high in cows in the TP barn; in the 2 SP barns, it decreased 0.4 to 0.6°C following sprinkling and milking. The intake activity and rumen digestion of cows raised in the 3 environments were similar. Cows in both TP barns ingested more dry matter. Cows in the TP+SP barn tended to produce more milk than those in the Fan+SP barn (25.4 vs. 24.7 kg). Although heat stress was not completely alleviated in these 3 barns, the TP+SP treatment resolved the negative effect of a previous TP barn built in 2004 on intake and milk yield by increasing air speed and using sprinkler cooling. Thus, it is expected that TP+SP barns will be beneficial in regions with high humidity. Adequate air speed and sprinkler cooling are likely to be key factors for further study.

The distribution of species and susceptibility of amphotericin B and fluconazole of yeast pathogens isolated from sterile sites in Taiwan.

To study the demographic changes of yeasts causing invasive infections in Taiwan, especially with respect to species distribution and antifungal susceptibility, we analyzed isolates obtained from four sterile sites of patients in 19 hospitals in 2002 (155 strains) and again from the same hospitals in 2006 (208 strains). Blood was the most common source of the yeasts, accounting for 73.8% of the total isolates, followed by ascites (21.5%), cerebrospinal fluid (3%), and synovia (1.7%). Candida albicans was the most frequently recovered species (50.1% of the total), followed by Candida tropicalis (20.7%), Candida glabrata (11.6%), Candida parapsilosis (8.5%), Cryptococcus neoformans (3.9%), Candida krusei (0.8%), and nine other species (4.3%). There were one (0.3%) and seven (1.9%) isolates with minimum inhibitory concentrations (MICs) of amphotericin B > or =2 mg/l after 24 h and 48 h incubation, respectively. In addition, there were 15 (4.3%) and 31 (8.6%) isolates with MICs of fluconazole > or =64 mg/l under the same conditions. The MIC(90) value of amphotericin B was 1 mg/l. The MIC(90) values of fluconazole were 4 mg/l after 24 h incubation and 32 mg/l after 48 h incubation. Interestingly, MICs for fluconazole > or =64 mg/l after 24 h were significantly higher for isolates obtained in 2006 than those in 2002 after 24 h (7.1% vs. 0.7%, p =0.009) and 48 h (13.5% vs. 2%, p =0.0003) incubations. The demographic difference between these two surveys is mainly due to one species, C. tropicalis.

Selective COX2 inhibition improves whole body and muscular insulin resistance in fructose-fed rats.

BACKGROUND: The effects of cyclooxygenase-1 (COX1) and cyclooxygenase-2 (COX2) inhibition on insulin resistance in subjects with the metabolic syndrome remain elusive. Aims of this study were to examine the effects of COX1 and COX2 inhibitors on whole body and muscular insulin resistance in fructose-fed rats, an animal model of the metabolic syndrome. MATERIALS AND METHODS: The rats on regular or 60% fructose-enriched diets for 6 weeks were further divided into rats combined with or without piroxicam (a selective COX1 inhibitor) or celecoxib (a selective COX2 inhibitor) treatment for an additional 2 weeks. Euglycaemic hyperinsulinaemic clamp (EHC) with a tracer dilution method was performed at the end of the study. RESULTS: The present result showed that fructose-induced increases in systolic blood pressure and fasting plasma insulin levels were significantly suppressed in rats treated with celecoxib but not piroxicam. In the EHC period, celecoxib significantly reversed fructose-induced decreases in whole body glucose uptake, mainly by glucose storage. Hepatic glucose production and whole body glycolysis were not significantly changed among groups. Celecoxib but not piroxicam significantly reversed fructose-induced decreases in glycogen synthase activities in red and white quadriceps muscles and insulin-stimulated membrane GLUT4 recruitment in soleus muscles. Celecoxib and piroxicam both significantly diminished fructose-induced increases in plasma thromboxane B2 and 6-keto prostaglandin (PG) F1alpha; but only celecoxib treatment significantly attenuated a fructose-induced increase in 8-isoprostane levels. Plasma PGE metabolites were not different among groups. CONCLUSIONS: This study demonstrates that a therapeutic dose of celecoxib, but not piroxicam, could significantly attenuate fructose-induced whole body and muscular insulin resistance in rats.

The effect of activation treatments on the development of reconstructed bovine oocytes.

The purpose of this study was to investigate the effect of different activation treatments on the development of IVM-derived and cloned bovine embryos. The effect of oocyte age (20h versus 24h after IVM) on the blastocyst rate was also investigated. No differences in the percentage of blastocyst development were observed between the oocytes matured for 20 and 24h (15% versus 27%, p>0.05). Reconstructed oocytes activated 4h after fusion (fusion before activation, FBA) had a higher blastocyst rate than those oocytes activated immediately after electrofusion (fusion and activation simultaneously, FAS) (26% versus 5%, p<0.01). Blastocyst rates were significantly greater (p<0.01) for the reconstructed oocytes activated by calcium ionophore (A23187) combined with 6-dimethylaminopurine (6-DMAP) (51.6%) than for those activated with cycloheximide (CHX) plus cytochalasin B (CB) treatment (1h, 8.2%; 5h, 14.3%). However, the blastocyst rates were similar among reconstructed oocytes activated by electric pulses and A23187 (30.5% versus 42.2%) or by A23187 and ionomycin (36.7% versus 33.3%) combined with 6-DMAP, respectively. Blastocysts that developed from reconstructed oocytes activated by A23187 and 6-DMAP resulted in three pregnancies (3/9) and one live birth from 18 embryos transferred to recipient cows. Genotypic analysis of six bovine microsatellite markers by polymerase chain reaction confirmed that the cloned calf was genetically identical to the nuclear donor. In conclusion, reconstructed oocytes that derived from oocytes exposed to activation treatment 4h after electrofusion are more likely to develop to the blastocyst stage. The best treatment to activate reconstructed bovine oocytes in this study was A23187 combined with 6-DMAP.

[Impact of HIV/HBV infection and HIV/HBV co-infection on outcomes of pregnancy].

Both HIV and HBV infection have become major health problems, of global concern, due to the high prevalence in the past few decades. Data from cumulated epidemiological surveys have shown the links between maternal HIV or HBV infection and adverse outcomes on pregnancy. Maternal HIV or HBV infection may also increase the mother-to-child (MTCT) transmission of the two diseases. However, association between HIV-HBV co-infection and adverse pregnancy is still inconclusive. Does maternal HIV-HBV co-infection have an impact on mother-to-child transmission on either HIV or HBV? Study on effective precautionary measures to promote both maternal and child's health is deemed necessary.

[A survey of HIV, HBV and HCV infections in children aged 1-13 years in Yi ethnic area, Sichuan province].

Objective: To investigate the prevalence of HIV, HBV and HCV infections in children aged 1-13 years in Yi ethnic area in Sichuan province. Methods: A cross-sectional study was conducted in the form of field survey in four townships selected from Yi ethnic area of Sichuan during 2014-2015. Participants were children aged 1-13 years by sample size of 900 and were screened for HIV antibody, HBV surface antigen and HCV antibody, and laboratory comfirmation was conducted. The area, age, gender and ethnic group specific infection rates were compared by using Fisher's exact test, and multiple comparisons were corrected by using Bonferroni correction. Results: A total of 677 children aged 1-13 years were surveyed. The infection rates of HIV, HBV and HCV were 1.03% (7/677, 95%CI: 0.42%-1.12%), 6.65% (45/677, 95%CI: 4.89%-8.79%) and 0.15% (1/677, 95%CI: 0%-0.82%), respectively. The infection rates of HIV differed among townships (P=0.000), the infection rate was higher in township D than in township B, the difference was significant (P<0.001). The differences in HIV infection rate among different age, gender and ethnic groups were not significant. The differences in HBV and HCV infections were not significant among different townships, age, gender and ethnic groups. The difference in HBV viral load between age group 5-9 years and age groups 10-13 years was not significant (U=115.000, P=0.967). Conclusions: The burden of HIV and HBV infections in children aged 1-13 years was heavy in rural area of Yi ethnic area in Sichuan. Therefore, it is necessary to take effective measures to block the vertical transmission of HIV and HBV as well as to increase the coverage of HBV vaccination.

The effect of electrical field strength on activation and development of cloned caprine embryos.

The activation procedure used in nuclear transfer (NT) is one of the critical factors affecting the efficiency of animal cloning. The purpose of this study was to compare the effect of two electrical field strengths (EFS) for activation on the developmental competence of caprine NT embryos reconstructed from ear skin fibroblasts of adult Alpine does. The NT embryos were obtained by transfer of the quiescent fibroblasts at the fourth passage into the enucleated metaphase II (M II) oocytes. Four to five hours after electrical fusion, the NT-embryos were activated by EFS either at 1.67 or at 2.33 kV/cm and immediately incubated in 6-DMAP (2 mM) for 4 h. The cleavage rate of the NT-embryos activated with 2.33 kV/cm was greater than that activated with 1.67 kV/cm after in vitro culture for 18 h (65.6% versus 19.6%, p < 0.001). No pregnancy was found in 14 recipient does after transferring 51 NT embryos at 1-2 cell stages activated with 1.67 kV/cm. In contrast, two of the seven recipients were pregnant and gave birth to three kids after transferring 61 NT embryos at 1-2 cell stages activated by 2.33 kV/cm. The birth weights of three cloned kids were within the normal range of Alpine goats. However, one kid died 1h after birth while the remaining two are still healthy. DNA analysis by polymerase chain reaction (single-strand conformation polymorphism, SSCP) confirmed that the three kids were genetically identical to the nuclear donor.

Use of nonautologous microencapsulated fibroblasts in growth hormone gene therapy to improve growth of midget swine.

The aim of the present study was to investigate the expression activity, both in vitro and in vivo, of the porcine growth hormone complementary DNA (pGH cDNA) in porcine fetal fibroblast (PFF) cells. The pGH gene had been constructed inside the bicistronic retroviral vector PSN and subsequently transfected into PFF cells further encapsulated with immunoprotective microcapsules. This would provide a way to evaluate the improvement in growth performance of Tao-Yuan swine by the use of nonautologous microencapsulated fibroblasts carrying the pGH cDNA via the technique of somatic gene therapy. Results from Southern blot analysis confirmed that the full length of the pGH cDNA was completely integrated into the genome of the PFF cells after they had been infected one to four times using a PSN retroviral vector. Moreover, Northern blot analysis showed that high transcription activity was present in clones infected twice, and exogenous pGH secretion was found when the pGH-infected PFF had been further cultured for 48 hr in vitro and subjected to immunoblot assay. Encapsulation of the pGH-PFF with an alginate-poly-L-lysine-alginate membrane did not show any deterioration in their proliferation and survival both in vitro and in vivo. The pGH gene in encapsulated recombinant fibroblasts was fully expressed after it had been transplanted into the peritoneal cavity of the Tao-Yuan swine, and reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed on the microcapsules retrieved 1 month later. The feasibility of pGH gene therapy to improve midget Tao-Yuan swine growth enhancement is further supported by the fact that transplantation of the encapsulated recombinant fibroblast cells resulted in a much more significant increase in weight gain than in those swine in either the age-matched untreated control group or in those that had been transplanted with uncapsulated recombinant PFF cells (10.56 +/- 1.01 kg versus 6.95 +/- 0.94 and 5.27 +/- 1.30 kg; p < 0.05). These experimental data suggest that growth hormone gene therapy did provide an alternative approach for growth improvement in midget Tao-Yuan swine.

Progesterone receptor gene expression in preimplantation pig embryos.

OBJECTIVE: It is not known whether progesterone, which plays a key role in establishing and maintaining pregnancy, acts directly on embryos or indirectly through the mother's reproductive tract. Since the physiological effects of progesterone are mediated by progesterone receptors (PR), the expression of PR during the preimplantation stages of pig embryos was determined. DESIGN AND METHODS: Preimplantation pig embryos at different developmental stages were examined using reverse transcription-polymerase chain reaction techniques for the purpose of determining PR gene expression. Immunocytochemistry procedures were used to determine whether PR mRNA is translated into PR protein in preimplantation embryos. RESULTS: PR mRNA was found in pig embryos at the two-cell stage, but levels started to decline at the four-cell stage; none was detected at the five- to eight-cell stage, nor at any time during the morula and blastocyst stages. Results showed that PR protein was immunostained in pig oocytes and embryos at the 4-cell stage, but that no significant immunostaining occurred during the morula and blastocyst stages. CONCLUSION: These results indicate that the effects of PR on early embryogenesis appear to be indirect, perhaps via PR-regulated growth-promoting factors produced in the maternal reproductive tract.

Growth enhancement of fowls by dietary administration of recombinant yeast cultures containing enriched growth hormone.

In present study the methylotrophic yeast, Pichia pastoris, was used to express a recombinant growth hormone (rGH) gene of swine. A synthetic secretion cassette was constructed using the promoter of the alcohol oxidase1 gene (AOX1), and a alpha-factor signal peptide. After electroporatic transformation and zeocin selection, several clones exhibited high levels of rGH protein expression constituting more than 20% of total yeast protein. Over 95% of rGH was shown to be export into the culture supernatant. Yeast transformant containing the highest recombinant growth hormone level (rGH yeast) and native GS115 Pichia pastoris (non-rGH yeast, as a control) were separately cultured, harvested and adsorbed by wheat bran. Yeast cultures of four dosages (0.05, 0.1, 0.2, and 0.4%) were mixed respectively with chick basal diet and fed to simulated country chickens for 9 weeks. The results showed that, when compared to control chicks, the percentage of body weight gain was improved significantly (P<0.05) in chicks fed with diets containing 0.1 or 0.2% rGH-rich yeast culture at brooding stage, and in chicks fed with 0.4% rGH-rich yeast culture at growing stage. The average weight gain in rGH yeast treated groups for the full-term (0 to 63d) and short term (43 to 63d) of growth were 10.6 and 9.4%, respectively, better than the non-rGH yeast control group. These experimental data suggest that the use of rGH-containing yeast as a supplement in fed provided an alternative approach for growth improvement in simulated country chickens.

Dispersion of organic pigments using supercritical carbon dioxide.

This research describes dispersion of organic pigments using supercritical fluids. With low surface tension and high diffusivity of fluids in supercritical states, aggregated particles may be effectively wetted and swelled to form the primary constituent of the dispersing solution by volume. In this paper, the conditions of temperature and pressure are used to control the density of supercritical carbon dioxide subject to PGMEA as cosolvent for dispersing organic powder in a solution. As shown from measurement with a laser scattering particle analyzer, the average diameter of phthalocyanine green 36 with the haloid structure can be significantly reduced to 93.5 nm; for aminoanthraquinone red containing and amino group (-NH(2)) and phthalocyanine blue 15:6 with symmetry benzene and inner hydrogen bond, the mean particle sizes are 178.5 and 188.7 nm, respectively, using supercritical CO(2). Additionally, the transmittance of UV light is used to confirm the dispersing performance in this study.

Growth hormone gene polymorphisms and growth performance traits in Duroc, Landrace and Tao-Yuan pigs.

This study investigated the restriction fragment length polymorphism (RFLP) of the porcine growth hormone (pGH) gene in Duroc, Landrace, and Tao-Yuan pigs and its effects on growth performance and levels of plasma growth hormone in peripheral circulation. Genomic DNA extracted from 81 Tao-Yuan, 60 Landrace and 48 Duroc pigs were subjected to Southern blot hybridization with a pGH cDNA probe. Polymorphism was detected with the restriction enzymes TaqI and DraI. A comparison of these three breeds showed significant differences in allelic frequencies. Blood samples for radioimmunoassay (RIA) of GH were collected biweekly during the experimental period from pigs 12 to 40 weeks of age. Tao-Yuan pigs showed a mean plasma GH level (2.51 +/- 1.23 ng/mL) that was much lower than that of the Landrace (3.80 +/- 1.52 ng/mL) and Duroc (4.20 +/- 1.03 ng/mL) pigs (P < 0.05). Moreover, the Tao-Yuan pigs also showed poorer growth performance than the Landrace and the Duroc pigs both in the daily weight gain (0.37 +/- 0.06 vs. 0.67 +/- 0.05 and 0.70 +/- 0.05 kg/day, P < 0.01) and feed efficiency (3.12 +/- 0.28 vs. 2.60 +/- 0.14 and 2.52 +/- 0.12, P < 0.05). These results suggest that the growth performance trait in these pigs is highly correlated with their growth hormone genotype.

Rewards of automated testing. Identifying problems before rollout can avoid system disruption.

PROBLEM: Needed order management application that performed consistently and met high demands. SOLUTION: Load testing identified specific problem areas. RESULTS: Precise description of problems and their occurrence helped speed resolution and ensured successful implementation. KEYS TO SUCCESS: Testing of conditions that emulated expected demands at early stage of design and planning.