An acute case of Pimelea elongata toxicity in cattle in western New South Wales.

In May 2019, 96 cattle died from Pimelea toxicity in a period of 19 days after potential exposure, with the first deaths occurring within 5 days. After examining the circumstances, we suspect that several factors contributed to the deaths. These included that recently purchased stock and transported had access to flooded land containing Pimelea elongata. This weed species contains simplexin and 18 other compounds. Roots, flowers and seeds are significantly more toxic than the stem, branches and leaves. We suspect that thirsty and hungry stock consumed seed and roots from flooded pastures and consumed lethal doses of simplexin. Blood tests were not good indicators of the conditions. Management strategies are suggested.

Evaluating irradiation dose for sterility induction and quality control of mass-produced fruit fly Bactrocera tryoni (Diptera: Tephritidae).

The sterile insect technique has been routinely used to eradicate fruit fly Bactrocera tryoni (Froggatt) incursions. This study considers whether fly quality in a mass-rearing facility can be improved by reducing irradiation doses, without sacrificing reproductive sterility. Pupae were exposed to one of five target irradiation dose ranges: 0, 40-45, 50-55, 60-65, and 70-75 Gy. Pupae were then assessed using routine quality control measures: flight ability, sex ratio, longevity under nutritional stress, emergence, and reproductive sterility. Irradiation did not have a significant effect on flight ability or sex ratio tests. Longevity under nutritional stress was significantly increased at 70-75 Gy, but no other doses differed from 0 Gy. Emergence was slightly reduced in the 50-55, 60-65, and 70-75 Gy treatments, but 40-45 Gy treatments did not differ from 0 Gy, though confounding temporal factors complicate interpretation. Reproductive sterility remained acceptable (> 99.5%) for all doses--40-45 Gy (99.78%), 50-55 Gy (100%), 60-65 Gy (100%), and 70-75 Gy (99.99%). We recommend that B. tryoni used in sterile insect technique releases be irradiated at a target dose of 50-55 Gy, providing improved quality and undiminished sterility in comparison with the current 70-75 Gy standard while also providing a substantial buffer against risk of under dosing.

Inferring modes of colonization for pest species using heterozygosity comparisons and a shared-allele test.

Long-range dispersal of a species may involve either a single long-distance movement from a core population or spreading via unobserved intermediate populations. Where the new populations originate as small propagules, genetic drift may be extreme and gene frequency or assignment methods may not prove useful in determining the relation between the core population and outbreak samples. We describe computationally simple resampling methods for use in this situation to distinguish between the different modes of dispersal. First, estimates of heterozygosity can be used to test for direct sampling from the core population and to estimate the effective size of intermediate populations. Second, a test of sharing of alleles, particularly rare alleles, can show whether outbreaks are related to each other rather than arriving as independent samples from the core population. The shared-allele statistic also serves as a genetic distance measure that is appropriate for small samples. These methods were applied to data on a fruit fly pest species, Bactrocera tryoni, which is quarantined from some horticultural areas in Australia. We concluded that the outbreaks in the quarantine zone came from a heterogeneous set of genetically differentiated populations, possibly ones that overwinter in the vicinity of the quarantine zone.

Modified procedure for isolation of epithelial cells of rat epididymal caput.

Epithelial cells of the rat's epididymal caput were cultivated according to own modification of the Kierszenbaum's method [1981]. The said modification consisted in developing primary cultures of the epithelial cells in the epididymal duct by making use of small tubular segments instead of deisolated cells of the whole epididymal duct wall. Such small segments of the tubules were procured by resorting to mechanical isolation and a 4-grade enzymatic isolation with trypsin and collagenase, whereupon the produced suspension of cells and tubules was filtered through a grid, the meshes of which being 40 X 50 microns in diameter. The cultures were made up exclusively of the tubular segments that had remained on the grid. The utilized technique of isolation gets rid of tubules from the external layer of muscle cells and fibroblasts as well as spermatozoa still prior to the inception of the culture, and provides the possibility to obtain a pure population of epithelial cells. The latter cells have the capacity to migrate from tubular fragments, and to form monolayer cultures. In the conducted cultures the epithelial cells commence secreting PAS-positive substance which was evidenced by means of histochemical and microscope-electron examinations.

[Morphologic evaluation of the effect of long-term administration of ammonium fluoride on the seminiferous epithelium and epididymis in the rat]. / Morfologiczna ocena wplywu przewleklego stosowania fluorku amonowego na nablonek plemnikotwórczy i najadrze szczura.

Male rats were subjected to 9-month-long exposure to ammonium fluoride. The performed evaluation covered the seminiferous epithelium and epididymis. The greatest changes in animals used in the experiment were observed in epididymis. A small number of spermatozoa were seen in the lumen of ductus epididymis, while in the epithelial cells there were increased phagocytic processes, providing a proof that injured reproductive cells were eliminated from the genital tract.

Leukaemic cell growth and aggregation in vitro.

Experiments were performed with two lymphoblastic mouse leukaemia, L1210 VA II cell population growing in vitro for 90 and 400 days. These cells were cultured for 9 days in Eagle's solution without exchanging the medium, and each day a sample was taken for determination of its density, viability of cells and cell diameter. In the cells of the 400 day old population the presence and number of aggregates was checked. Lipid, nucleotide, nucleic acid, DNA and protein contents were determined in these cells. The present experiment in vitro was arranged to observe an aggregation of leukaemia cells during culture without change of the medium. The density and viability of cells changes of their metabolism in this system may stimulate the situation in vivo after dissemination of cells to a new place.

Zinc content in epididymal spermatozoa of metoclopramide-treated rats.

Zinc content was determined separately in spermatozoa taken from epididymal caput and cauda in rats. It was revealed that spermatozoa transported from the epididymal caput to the cauda reduce about 54% of zinc. This reduction is significantly inhibited in spermatozoa of rats receiving metoclopramide. That is also accompanied by a fall of testosterone level in blood serum and of delta 5, 3 beta-HSD activity in Leydig cells. It was found out that the reduction of zinc in spermatozoa at the time of their passage through the epididymis is the process that depends on androgens.