Prevention of Toxoplasma gondii abortion in goats by vaccination with oocysts of Hammondia hammondi

Nineteen does (female goats) were dosed with 500,000 oocytes of Hammondia hammondi prior to breeding. At about 90 days of gestation these, and 18 uninoculated does were challenged with 25,000 Toxoplasma gondii oocysts. The 19 H. hammondi--inoculated does produced 26 live and one dead kid (newborn goat). The 18 does not given H. hammondi produced 12 live and 19 dead kids. However, examination of all of the kids by isolation of T. gondii in mice, serology and histology revealed that they were all infected with T. gondii. Thus, while H. hammondi "vaccination" is protective against the deleterious effects of T. gondii on pregnant does, perhaps by reducing the severity of placental lesions, it does not prevent foetal infection.     

Pathology of experimentally-induced, acute toxoplasmosis in macropods

SUMMARY Thirteen Tammar wallabies (Macropus eugenii) were dosed orally with 500, 1000 or 10 000 oocysts of Toxoplasma gondii, as part of a vaccination trial. Eleven animals died of acute toxoplasmosis 9 to 15 days after challenge. The lesions were similar in all animals, consisting of foci of necrosis and inflammation in the intestines, lymphoid tissue, adrenal cortex, heart, skeletal muscle and brain, and severe generalised pulmonary congestion and oedema. Free and intracellular tachyzoites of Toxoplasma were associated with the lesions. The remaining 2 animals had shown no signs of disease when euthanased four months after challenge. Small, focal, non-suppurative inflammatory lesions were seen in brain, heart and skeletal muscle of these animals and chronic Toxoplasma infection was confirmed by mouse inoculation.     

Off-axis crustal thickness across and along the east pacific rise within the MELT area

Wide-angle seismic data along the Mantle Electromagnetic and Tomography (MELT) arrays show that the thickness of 0.5- to 1. 5-million-year-old crust of the Nazca Plate is not resolvably different from that of the Pacific Plate, despite an asymmetry in depth and gravity across this portion of the East Pacific Rise. Crustal thickness on similarly aged crust on the Nazca plate near a magmatically robust part of the East Pacific Rise at 17 degrees15'S is slightly thinner (5.1 to 5.7 kilometers) than at the 15 degrees55'S overlapping spreading center (5.8 to 6.3 kilometers). This small north-south off-axis crustal thickness difference may reflect along-axis temporal variations in magma supply, whereas the across-axis asymmetry in depth and gravity must be caused by density variations in the underlying mantle.     

水稻分支酶基因 Sbe1和 Sbe3 cDNA的克隆及全序列分析

 通过改良的RT PCR法合成了水稻未成熟种子胚乳cDNA库，并以此为模板，用PCR技术从粳稻品种武运粳7号中克隆了分别编码淀粉分支酶SBEⅠ和SBEⅢ的2个基因Sbe1和Sbe3。序列分析表明，克隆Sbe1和Sbe3基因的大小分别为2490 bp和2481 bp，包含了基因完整的编码序列。Sbe3基因与已发表基因全序列完全相同，同源性达100%；Sbe1基因与已发表基因序列有4个碱基不同，同源性为99.84%，推导氨基酸序列的差异为2个。     

Glutathione Transferase Isozymes Involved in Insecticide Resistance of Diamondback Moth Larvae

In addition to the three glutathione transferase (GST) isozymes already identified in diamondback moth larvae, Plutella xylostella (L.), a fourth one, GST-4, was purified from a teflubenzuron (TFB)-resistant strain. This GST isozyme was similar to GST-3 in terms of biochemical and toxicological properties. GST-4, a homodimer with a subunit molecular mass of 26.6 kDa and a pI of ca. 8.9, displayed even stronger substrate preference than GST-3 for 1,2-dichloro-4-nitrobenzene and several organophosphorus insecticides, i.e., parathion, methyl parathion, and paraoxon. These two proteins were highly immunorelated and shared at least the first eight amino acids at the N-terminus. Immunoblotting analysis indicated that polyclonal antiserum raised against GST-3 cross-reacted with GST-1 and GST-2 at least 40-fold less intensely than with the antigen. Using this antiserum as probe, higher amounts and greater variations of GST-3/GST-4 were observed in larvae of a methyl parathion- and a TFB-resistant strain compared with a susceptible and a fenvalerate-resistant strain. Among the six lepidopterous insects examined, only Spodoptera exigua larvae clearly had proteins immunorelated to GST-3/GST-4 of diamondback moth. No such cross-reactivity was observed in Musca domestica, Drosophila melanogaster, and Aedes aegypti.