Serological and pathological studies of Newcastle disease viruses isolated from caged birds from Southeast Asia

Eleven isolates of Newcastle disease virus (NDV), from caged birds imported from or captured in Southeast Asia in 1979-80, were antigenically divided into five distinct groups. Most of them were distinguishable from more classical NDVs (vaccine B1 strain and Miyadera strain) on the basis of their reactivity to eight monoclonal antibodies against the HN molecule of NDV in hemagglutination-inhibition tests. However, when three representative isolates were evaluated for their biological properties and pathogenicity against 1-day-old chickens, all three were found to be velogenic types that could induce serious symptoms of Newcastle disease and which eventually killed all of the chickens, regardless of the route of infection. There was not any significant correlation between their reactivity patterns with the monoclonal antibodies and their virulence.     

Protection against atypical Aeromonas salmonicida infection in carp (Cyprinus carpio L.) by oral administration of humus extract

Humic substances are formed during the decomposition of organic matter in humus, and are found in many natural environments in which organic materials and microorganisms have been present. In the present study, oral administration of humus extract to common carp (Cyprinus carpio L.) induced effective protection against experimental atypical Aeromonas salmonicida infection. Mortality of fish and development of skin lesions such as hemorrhages and ulcers were significantly suppressed in carp treated with 10%, 5% or 1% humus extract adsorbed on dry feeding pellets. The median surviving days was also greater in fish treated with 10% or 5% humus extract than in untreated fish. Atypical A. salmonicida was isolated from ulcerative lesions of part of dead fish, but Aeromonas hydrophila and Flavobacterium sp. were also isolated from these fish, verifying bacterial population changes during the progression of skin lesions. These results clearly show that treatment of fish with humus extract is effective in preventing A. salmonicida disease.     

Antitumor effect of humus extract on murine transplantable L1210 leukemia

Humic substances are formed during the decomposition of organic matter in humus that found in many natural environments in which organic materials and microorganisms have been present. In the present study, humus extract exhibited antitumor effect on L1210 tumor development in isogeneic DBA/2 mice with the delay of tumor formation and a significant smaller tumor mass that infer a significant increase of life span of mice. The antitumor effect was not due to direct killing of L1210 or induction of apoptosis in tumor cells by humus extract.     

In vitro enhancement by CpG ODN of phagocytic activity of rainbow trout head kidney phagocytes against fish pathogen Vibrio ordalii, but not against polystyrene particles

Rainbow trout (Oncorhynchus mykiss) head kidney phagocytes precultured with a synthetic cytidine-phosphate-guanosine (CpG) oligodeoxynucleotide (ODN) displayed significantly higher phagocytic activity against Vibrio ordalii than phagocytes precultured with non-CpG ODN. However, head kidney phagocytes precultured with CpG ODN did not show enhanced phagocytic activity against polystyrene particles.     

Development of a multiplex polymerase chain reaction method for simultaneous detection of eight events of genetically modified maize

In this study, we developed a novel multiplex polymerase chain reaction (PCR) method for simultaneous detection of up to eight events of genetically modified (GM) maize within a single reaction. The eight detection primer pairs designed to be construct specific for eight respective GM events (i.e., Bt11, Event176, GA21, MON810, MON863, NK603, T25, and TC1507) and a primer pair for an endogenous reference gene, ssIIb, were included in the nonaplex(9plex) PCR system, and its amplified products could be distinguished by agarose gel and capillary electrophoreses based on their different lengths. The optimal condition enabled us to reliably amplify two fragments corresponding to a construct specific sequence and a taxon specific ssIIb in each of the eight events of GM maize and all of nine fragments in a simulated GM mixture containing as little as 0.25% (w/w) each of eight events of GM maize. These results indicate that this multiplex PCR method could be an effective qualitative detection method for screening GM maize.     

Effect of fulvic acid on the crystallization of aluminum hydroxides

Effects of addition of increasing amounts of fulvic acid (FA) on the crystallization of aluminum hydroxides from AlCl₃, solution, neutralized to different degrees, were investigated. All systems were allowed to age at 30°C for 70 days.In the absence of FA, gibbsite was formed at pH 6, a mixture of nordstrandite and bayerite at pH 8, and bayerite crystallized at pH 10. At pH 6 and 8, the addition of increasing amounts of FA (up to 10 mg/l or $\text{FA/Al molar ratio}\text{? 10}{}^{\mathrm{?2}}$) first delayed and then inhibited the crystallization of these aluminum-hydroxide polymorphs but tended to favor the crystallization of pseudoboehmite, an aluminum oxyhydroxide. At pH 10, the addition of FA totally inhibited crystallization and precipitation.Our data suggest that FA so strongly complexes Al that it prevents its full hydroxylation to Al(OH)₃. Another explanation is that the action of FA on the crystallization of aluminum hydroxides resembles that of salts in that FA appears to favor the formation of Al-O-Al (oxo) over that of

(ol) linkages. Either reaction mechanism throws new light on the genesis of some bauxites, which consist of submicroscopic boehmite-like particles which are very similar to pseudoboehmite.     

Solubility and application effects of African low-grade phosphate rock calcinated with potassium carbonate

This article indicates solubility improvement of African low-grade phosphate rock (PR) through calcination with potassium carbonate. We showed calcination with potassium carbonate made its citric acid solubility up to 100%, and reinforcement of its application effect. In sub-Saharan Africa, although many phosphate deposits have been found, farmers are facing high prices of P fertilizers because of the low solubility of the African PRs. We previously reported PR calcination with Na carbonate improves the solubility, but their application produced limited crop growth, especially in upland conditions. It was speculated soil Na accumulation caused plant growth inhibition. Therefore, we tried to elucidate the effect of calcination with potassium carbonate on PR solubility and its application effects for lowland rice and maize through pot experiments. We used Kodjari PR produced in Burkina Faso for the calcination. Powdered PRs were mixed with K₂CO₃ in five doses to achieve the target K₂O compositions of 200, 250, 300, 350, and 400 g kg^-1. The pelletized PR-K₂CO₃ mixtures were calcined at 900, 1000, 1050, and 1100 °C for 10 min. The pot experiments were conducted for 56 days, monitoring the growth of rice and maize under several application rates. Calcination with K carbonate generated K-rhenanite (KCaPO₄) and kaliophilite (KAlSiO₄), and the solubility reached about 100% in 20 g L^-1 citric acid and about 40% in water. This shows that K carbonates behave like Na carbonate in the solubilization of Kodjari PRs. Although the calcinated Burkina PR (CB) application significantly reduced plant growth when it was applied at an excessive rate, reduced application rates yielded comparable plant growth to that of triple super phosphate (TSP). K carbonate calcination deterred Na accumulation in the soil, and it was effective for plant growth. However, CB easily causes plant damage in excessive application, and it may contain phytotoxicant substances.     

Motility and fertility of boar semen after liquid preservation at 5°C for more than 2 weeks

This study investigated the effects of skim milk on the quality and fertility of boar spermatozoa under long‐term chilled preservation. Semen samples were stored in Modena solution supplemented with 0 (control) to 50 mg/mL skim milk at 5°C for 4 weeks; spermatozoa stored with 7.5 and 15 mg/mL of skim milk (7.5‐SM and 15‐SM groups, respectively) exhibited significantly higher motility indices than those of the control group up to 3 weeks (P < 0.05), and the 7.5‐SM group showed improved motility indices even after 4 weeks (P < 0.05). In vitro fertilization using spermatozoa in the 7.5‐SM and 15‐SM groups stored at 5°C for 2 weeks showed significantly higher fertilization rates of spermatozoa and the development rates to blastocyst than the control group (P < 0.05), and the 7.5‐SM group showed similar rates of fertilization and blastocyst formation in the fresh non‐stored spermatozoa group. After artificial insemination using spermatozoa stored for 2 weeks in the 7.5‐SM group, healthy piglets were obtained. Boar spermatozoa can be stored at 5°C in a Modena solution containing skim milk. Supplementation of 7.5 mg/mL skim milk improves boar spermatozoa motility and fertility even after liquid preservation at 5°C for 2 weeks.