Production of HanWoo (Bos taurus coreanae) fetuses following interbreed somatic cell nuclear transfer

The possibility of producing HanWoo (Bos taurus coreanae) calves from transferable bovine embryos, obtained by interbreed nuclear transfer using Holstein cytoplasts and surrogates, was investigated. As donor nuclei, HanWoo fetal fibroblasts were used. Cells were induced into quiescence by serum deprivation for 4-7 days before nuclear transfer. In vitro matured Holstein oocytes were enucleated, and single donor cell was placed into the perivitelline space of enucleated oocyte. After reconstruction, the embryos were fused. activated and cultured. On day 7, the embryos that developed to the blastocyst stages were transferred into Holstein recipient cows on day 6 to 7 of estrous cycle (estrus=0). The reconstructed embryos were successfully fused (58.8%; 47/80), cleaved (91.5%; 43/47), and developed to blastocysts (29.8%; 14/47). Eleven blastocysts were transferred into 5 Holstein recipient cows. Two recipients were pregnant, confirmed by ultrasonography at day 60 of gestation. But, one of them was opened between on day 80 to 100 of pregnancy, and the other had a stillbirth on day 255. The stillborn calf was physically normal, and we couldn't find any evidence of anomaly. These results show that cells derived from HanWoo somatic cell lines can be reprogrammed by interbreed nuclear transfer and develop subsequently in vivo as well as in vitro.     

Immunogenicity and efficacy of the oral rabies vaccine SAD B19 in foxes

Studies on the immunogenicity and efficacy of SAD B19 attenuated rabies virus vaccine in foxes under laboratory conditions were conducted. Twenty-seven foxes (Vulpes vulpes) were offered a vaccine bait containing 10(6.3) FFU/ml SAD B19. Blood samples were collected 60, 110 and 190 days post-vaccination. On day 190 post vaccination the animals and 14 controls were challenged with a canid street rabies virus. Twenty-four of the 26 vaccinated foxes (92.3%) survived the challenge, whereas all the controls died from rabies. The two vaccinated foxes that did not survive the challenge did not show any detectable level of rabies neutralizing antibodies at any time after vaccination. The geometric mean titres (GMT) of foxes that seroconverted after vaccination were 43.5, 33.9 and 43.5 IU/ml 60, 110 and 190 days post-vaccination, respectively. Furthermore, to test the vaccine virus under sub-optimal conditions five naive and nine previously vaccinated vixens received 2 ml SAD B19 (10(6.7) FFU/ml) by direct administration of the vaccine virus into the oral cavity shortly before or during pregnancy. All vixens seroconverted above the threshold of 0.5 IU/ml. No booster effect was observed in the immune response of the previously vaccinated animals.     

Effect of supplementation of dry cat food with D,L-methionine and ammonium chloride on struvite activity product and sediment in urine

Feeding dry foods supplemented with urine acidifier (D,L-methionine (Met) or ammonium chloride) decreased urinary pH and struvite activity product in clinically normal cats. As a result, the number of struvite crystals in urine was greatly reduced. Supplementation with 3% Met but not 1% Met caused decrease in the urinary concentration of sediment, which resulted from a reduction in the HCl-soluble fraction. The concentration of HCl-insoluble sediment was not affected by supplementation with the urine acidifier.     

Changes in ascorbic acid content in primary cultured rat hepatocytes exposed to 2,2'-azobis (2-amidinopropane) dihydrochloride, a radical initiator

Changes in ascorbate content in primary cultured rat hepatocytes exposed to oxidative stress derived from water soluble radical initiator 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) were examined. Cells were exposed to 0.05 and 5 mg/ml of AAPH as 'mild' and severe' oxidative stresses, respectively. Lipid peroxidation in hepatocytes was induced by 'severe' oxidative stress, but not by 'mild' oxidative stress. Ascorbate decreased at 6 hr after administration of both mild' and severe' oxidative stresses, and recovered to the control level after a further 6 hr. In cells treated with 'severe oxidative stress, however, total ascorbate (reduced form plus oxidized form) had increased 24 hr after administration. These results indicated that consumption alone did not account for the increase of ascorbate in hepatocytes under oxidative stress.     

Adjuvant post-operative chemotherapy in bitches with mammary cancer

The survival time in a group of eight bitches with malignant mammary tumours given adjuvant post-operative chemotherapy was compared with survival in another group of eight bitches with mammary cancer which were treated by surgical excision alone. The same surgical procedure was used in both groups. All bitches had stage III disease according to the World Health Organization clinical staging system. Histologically, 10 of the bitches had complex carcinomas (carcinomatous mixed tumours), the remaining six bitches had carcinosarcomas. The chemotherapeutic protocol used was a combination of 5-fluorouracil (150 mg/m2 of body surface area) and cyclophosphamide (100 mg/m2) given on the same day, intravenously, every week for four consecutive weeks. Chemotherapy was started one week post-surgery. Selected haematological parameters (packed cell volume, white blood cell count, platelet count and differential white blood cell count) and serum biochemical parameters (alanine aminotransferase, alkaline phosphatase, blood urea nitrogen and creatinine) were measured before and during chemotherapy. Survival analysis indicated that the chemotherapeutic regimen had a positive influence on the disease-free interval and the survival time of the eight bitches (P < 0.05). Although leucocyte numbers were significantly decreased (P < 0.001) during chemotherapy, the mean leucocyte counts remained within normal limits. Temporary leukopenia was noted only in one bitch. Packed cell volume and alkaline phosphatase increased significantly (P < 0.05) but within normal limits. Creatinine was also increased significantly (P < 0.01) but the mean creatinine concentrations were within normal limits, although in half of the bitches the concentrations occasionally rose above normal.     

Greenhouse tomato limited cluster production systems: crop management practices affect yield

Limited-cluster production systems may be a useful strategy to increase crop production and profitability for the greenhouse tomato (Lycopersicon esculentum Mill). In this study, using an ebb-and-flood hydroponics system, we modified plant architecture and spacing and determined the effects on fruit yield and harvest index at two light levels. Single-cluster plants pruned to allow two leaves above the cluster had 25% higher fruit yields than did plants pruned directly above the cluster; this was due to an increase in fruit weight, not fruit number. Both fruit yield and harvest index were greater for all single-cluster plants at the higher light level because of increases in both fruit weight and fruit number. Fruit yield for two-cluster plants was 30% to 40% higher than for single-cluster plants, and there was little difference in the dates or length of the harvest period. Fruit yield for three-cluster plants was not significantly different from that of two-cluster plants; moreover, the harvest period was delayed by 5 days. Plant density (5.5, 7.4, 9.2 plants/m2) affected fruit yield/plant, but not fruit yield/unit area. Given the higher costs for materials and labor associated with higher plant densities, a two-cluster crop at 5.5 plants/m2 with two leaves above the cluster was the best of the production system strategies tested.     

Factors Affecting Latent Infection of Prune Fruit by Monilinia fructicola

ABSTRACT Experiments were conducted in three prune orchards in California. In each orchard, inoculations with Monilinia fructicola, the causal agent of brown rot of stone fruits, were performed on branches of trees at bloom and fruit developmental stages. Five inoculum concentrations were used in each inoculation. Six and four wetness durations were created for each inoculum concentration at bloom and fruit developmental stages, respectively. Fruit were harvested 3 weeks before commercial harvest. The overnight freezing incubation technique was used to promote sporulation and to determine incidence of latent infection (ILI) of fruit brown rot. No differences in ILI among locations were found. A seasonal pattern of bloom and fruit susceptibility to latent infection was determined. Susceptibility to latent infection at bloom stage was at a moderate level and increased to reach the highest level at pit hardening stage. Subsequently, fruit susceptibility to latent infection decreased, reaching the lowest level in early June at embryo growth stage. Thereafter, the susceptibility increased again with fruit development and maturity until harvest. Linear relationships between ILI and inoculum concentration were obtained for most combinations of growth stage and wetness duration. Incidence of latent infection increased linearly with increased wetness duration at bloom stage and increased exponentially with increased wetness duration at early and late fruit developmental stages. The optimum temperatures for latent infection at pit hardening stage ranged from 14 to 18 degrees C, but the effect of temperature on latent infection was reduced at resistant stages. The temperature range favorable to latent infection varied for different wetness durations.     

Antimicrobial Activity of Culture Filtrate of Bacillus amyloliquefaciens RC-2 Isolated from Mulberry Leaves

ABSTRACT A potential antagonist, Bacillus amyloliquefaciens strain RC-2, against Colletotrichum dematium, mulberry anthracnose fungus, was obtained from healthy mulberry leaves by in vitro and in vivo screening techniques. Application of culture filtrate of RC-2 inhibited disease on mulberry leaves, indicating that suppression was due to antifungal compounds in the filtrate. Development of mulberry anthracnose on mulberry leaves was inhibited only when the culture filtrate was applied before fungal inoculation, and it was not inhibited by application after inoculation. These results suggest that the antifungal compounds in the filtrate exhibit a preventive effect on the disease. Peptone significantly increased production of the antifungal compounds. The culture filtrate of RC-2 also inhibited the growth of several other phytopathogenic fungi and bacteria, such as Rosellinia necatrix, Pyricularia oryzae, Agrobacterium tumefaciens, and Xanthomonas campestris pv. campestris, in vitro. From the culture filtrate of RC-2, seven kinds of antifungal compounds were isolated by high performance liquid chromatography analysis, and one of the compounds was determined as iturin A2, a cyclic peptide, by nuclear magnetic resonance and fast atom bombardment mass analysis.     

Genetic Control and Host Range of Avirulence Toward Brassica napus Cultivars Quinta and Jet Neuf in Leptosphaeria maculans

ABSTRACT Leptosphaeria maculans causes blackleg of oilseed rape. Gene-for-gene interactions between race PG3 and Brassica napus cv. Quinta were related to interaction between the fungal avirulence (Avr) gene AvrLm1 and the corresponding resistance gene Rlm1. AvrLm1 isolates were aviru-lent on cvs. Doublol, Vivol, Columbus, and Capitol, and no recombinant phenotypes were observed in the progeny of two AvrLm1 x avrLm1 crosses, suggesting that all of these cultivars may possess Rlm1 or genes displaying the same recognition spectrum, or that a cluster of Avr genes is present at the Avrlm1 locus. In one cross, segregation distortion was observed at the AvrLm1 locus that could be explained by interaction between AvrLm1 and one unlinked deleterious gene, termed Del1. Incompatibility toward cvs. Jet Neuf and Darmor.bzh was governed by a single gene, unlinked to AvrLm1 or Del1. This avirulence gene was termed AvrLm4. Preliminary plant genetic analysis suggested the occurrence of a corresponding dominant resistance gene, termed Rlm4, present in the Quinta line analyzed and linked to Rlm1.     

Using mini-rockwool blocks as growing media for limited-cluster tomato production

Rockwool is an excellent growing medium for the hydroponic production of tomato; however, the standard size rockwool blocks [4 x 4 x 2.5 inches (10 x 10 x 6.3 cm) or 3 x 3 x 2.5 inches (7.5 x 7.5 x 6.3 cm)] are expensive. The following experiments were conducted with less expensive minirock wool blocks (MRBs), on rayon polyester material (RPM) as a bench top liner, to reduce the production cost of tomatoes (Lycopersicon esculentum) grown in a limited-cluster, ebb and flood hydroponic cultivation system. Fruit yield for single-cluster plants growing in MRBs [2 x 2 x 1.6 inches (5 x 5 x 4 cm) and 1.6 x 1.6 x 1.6 inches (4 x 4 x 4 cm)] was not significantly different from plants grown in larger sized blocks (3 x 3 x 2.5 inches). When the bench top was lined with RPM, roots penetrated the RPM, and an extensive root mat developed between the RPM and the bench top. The fruit yield from plants on RPM was significantly increased compared to plants without RPM due to increases in fruit size and fruit number. RPM also significantly reduced the incidence of blossom-end rot. In a second experiment, single- and double-cluster plants were grown on RPM. Fruit yield for double-cluster plants was 40% greater than for single-cluster plants due to an increase in fruit number, although the fruit were smaller in size. As in the first experiment, fruit yield for all plants grown in MRBs was not significantly different from plants grown in the larger sized blocks. MRBs and a RPM bench liner are an effective combination in the production of limited-cluster hydroponic tomatoes.