Liver biopsy techniques for adult horses and neonatal foals to assess copper status

Objective To evaluate standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals, as techniques for obtaining tissue for assessment of copper status. The techniques were evaluated with respect to ease of use and effect on the animal.
Procedure Twenty of 24 Thoroughbred mares and 21 of their foals were biopsied. The animals were part of a larger study of the effect of copper supplementation on copper status and the prevalence of developmental orthopaedic disease. Livers were also collected from unrelated horses and sampled to investigate the variability in the distribution of copper in liver tissue.
Result The biopsy technique caused no lasting effect on the mares, but there was an increased risk of viscus penetration associated with taking multiple biopsy cores. The use of ultrasonography to scan the target area for the liver identified four cases that were not appropriate candidates for liver biopsy, because of large intestine being located in the biopsy area. In the foals there were no serious postoperative adverse effects, nor was there any evidence of problems caused by the procedure when the abdomen was examined post-mortem at 5 months of age. In livers collected to investigate the variability of copper concentration, copper appeared to be relatively evenly distributed through the liver.
Conclusion Standing, percutaneous, ultrasound-guided, transthoracic liver biopsy in mares, and transabdominal, laparoscopically-guided, liver biopsy under general anaesthesia in foals are convenient procedures for obtaining liver tissue for assessing copper status in horses. The use of ultrasound to identify liver tissue is recommended, especially in older mares.     

Sesbania seed collections in Southern Africa

The International Centre for Research in Agroforestry (ICRAF) is a member of the Consultative Group on International Agricultural Research (CGIAR) system and has recently established a Multipurpose Tree Germplasm Resource Unit (MPT-GRU) in Nairobi, Kenya. The first major activity of the MPT-GRU was to undertake a regional germplasm collection ofSesbania in 5 countries in southern Africa in a collaborative mode with National Agricultural Research Services (NARS). The collections took place in Botswana, Malawi, Namibia, Zambia and Zimbabwe.Key elements of a generalised collaborative mode (the model) are indicated follwed by a summary of actual events. The initial phase involved joint planning and training sessions between NARS, three sister CGIAR centres and one regional institution, the Southern Africa Development Conference (SADC) Regional Gene Bank (SRGB). This was followed by actual collections during 1993 led by National scientists with different levels of CGIAR participation in each of the five countries. The International Board of Plant Genetic Resources (IBPGR) took the lead in pre-collection training activities, ICRAF for developing the collection programme and the International Livestock Centre for Africa (ILCA) for seed drying, testing and despatch for field trials. NARS gene banks guided the necessary administrative processes. The ICRAF lead scientist for the species and provenance evaluation phase was a crucial member of the planning process thus allowing integration of the collection with the eventual field evaluation. The article focuses on the collection strategy, administrative protocols for actual collections and summary results. Some advantages and difficulties associated with the collection programme and model are discussed. The collections were important in bringing together agriculturalists and foresters in a common germplasm collection exercise.     

Further evaluation of the use of buparvaquone in the infection and treatment method of immunizing cattle against Theileria parva derived from African buffalo (Syncerus caffer).

Three experiments were undertaken to determine the efficacy of different doses of buparvaquone in the infection and treatment immunization of cattle against Theileria parva derived from African buffalo (Syncerus caffer). Two of these experiments also compared buparvaquone with standard doses of long- and short-acting formulations of oxytetracycline. In addition, different dilutions of stabilates were used in the experiments. In the first experiment, a 10(-1.0) dilution of stabilate was used to infect groups of cattle treated with buparvaquone at doses of between 5 and 0.625 mg kg-1 body weight (bwt) on Day 0 after infection. All control cattle developed severe theileriosis and none of the treatment regimes (including those utilizing long-acting oxytetracycline) prevented the development of theileriosis. Treatment with buparvaquone at 2.5 mg kg-1 bwt or oxytetracycline gave the most satisfactory results. In the second experiment when the sporozoite dose was reduced to 10(-2.0) dilution, buparvaquone treatment at 5 and 2.5 mg kg-1 bwt and short- and long-acting formulations of oxytetracycline reduced reactions greatly. While all the oxytetracycline treated animals produced a serological response and were immune to a 50-fold higher challenge with the immunizing stabilate, several animals in the buparvaquone groups did not show a serological response and were not immune to challenge. In the third experiment, groups of cattle were infected with 10(-1.2), 10(-1.4) and 10(-1.6) dilutions of stabilate and were treated with 2.5 mg kg-1 bwt of buparvaquone. No animals developed severe theileriosis and all seroconverted. On homologous challenge, however, two out of 14 cattle showed severe reactions. It was concluded that further work on immunization using buparvaquone treatment at 2.5 mg kg-1 bwt and 10(-1.6) dilution of the stabilate would have to be carried out before such a system could be used in the field.     

7500 years of prehistoric footwear from arnold research cave, missouri

Accelerator mass spectrometer dating of an assemblage of fibrous and leather footwear from Arnold Research Cave in central Missouri documents a long sequence of shoe construction by prehistoric Midwestern peoples, beginning perhaps as early as 8300 calendar years before the present (cal years B.P.). An earlier fibrous sandal form dates from 8325 to 7675 cal years B.P., and later fibrous or leather slip-ons span the period from 5575 to 1070 cal years B.P. The assemblage adds to a growing picture of the highly varied nature of prehistoric footwear production in the United States throughout the Holocene.     

Rinderpest seroprevalence in wildlife in Kenya and Tanzania, 1982-1993

Eight hundred and thirty five serum samples collected from eight wild artiodactyl species in Kenya and Tanzania between 1982 and 1993 were tested for virus-neutralising (VN) antibodies to rinderpest (RP) virus. Antibodies were found in 116 of 344 buffaloes (Syncerus caffer) but not in the other species including 349 wildebeest (Connochaetes taurinus). Most of the antibody positive buffaloes were from the Maasai Mara-Serengeti ecosystem (MM-SE) and would have had opportunity for exposure to the virus during the epidemic of rinderpest in buffalo confirmed there in 1982. Buffalo born after 1985 did not have antibody indicating that virus stopped circulating in this population at or around that time. This second demonstration that RP virus disappears from the MM-SE is further evidence that these species are not permanent reservoirs of this virus. Re-infection of wildlife is transient and they remain valuable sentinels for infection in nearby domestic livestock.     

Some preliminary observations on the susceptibility and resistance of different cattle breeds to Theileria parva infection

Theileria parva-na?ve Friesian (Bos taurus), Boran (Bos indicus) and Maasai Zebu steers (B. indicus) were infected with a T. parva sporozoite stabilate dose which had previously been shown to induce an estimated 50% mortality rate in Boran cattle. All the cattle developed patent infections with no significant differences in the length of the prepatent period to development of macroschizonts (P > 0.05) between the three groups. Clinical theileriosis occurred in all eight the Friesians (100%), five out of nine Borans (55.6%) and two out of five Zebus (40%). Three of the Friesians (37.5%), and two of the Borans (22.2%) died of theileriosis. The different cattle types were equally susceptible to the infective dose used as indicated by the length of the prepatent periods, but there was a marked difference in their development of clinical theileriosis. The gradation in resistance to disease confirms the findings of earlier less critical studies and identifies these cattle breeds as suitable for investigations into the mechanisms of resistance to theileriosis.