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.     

中国三尖杉属植物资源研究

三尖杉属（Ｃｅｐｈａｌｏｔａｘｕｓ）隶属于三尖杉科（Ｃｅｐｈａｌｏｔａｘａｃｅａｅ）。该科仅１属９种，中国产７种３变种，１引种栽培变种。分布于亚洲东部至南亚次大陆。供药用的有三尖杉（ＣｆｏｒｔｕｎｅｉＨｏｏｋｆ）、粗榧［Ｃｓｉｎｅｎｓｉｓ（ＲｅｌｄｅｔＷｉｌｓ）Ｌｉ］、海南粗榧（ＣｈａｉｎａｎｅｎｓｉｓＬｉ）和篦子三尖杉（ＣｏｌｉｖｅｒｉＭａｓｔ）。细胞组织培养技术是开辟该属资源的重要途径，对合理开发利用这一资源具有重要意义。     

Genetic Diversity of Tea Plant （Camellia Sinensis （L.） O.Kuntze） in Wuling Mountainous Area Revealed by ISSR Marker

Genetic diversity and relationship of 183 tea germplasms were assessed by inter-simple sequence repeat （ISSR） marker.The study optimized the ISSR-PCR system for tea plants.Results show that genetic similarity among 183 tea ascensions was between 0.52-0.93,indicating a wide gene pool and a broad genetic variation of Wuling tea resources.The highest similarity of all materials between No1 and No2 was 0.93.Dendrogram of the 183 tea germplasms were protracted by UPGMA clustering analysis also revealed the genetic diversity and relationship of the tea germplasms of Wuling mountainous area.Besides,fingerprint of the 183 tea germplasms were constructed.     

N and P resorption in a pioneer shrub （Artemisia halodendron） inhabiting severely desertified lands of Northern China

Nutrient resorption is an important conservation mechanism for plants to overcome nutrient limitation in the less fertile area of desertified land.In the semi-arid Horqin Sandy Land of Northern China,the shrub Artemisia halodendron usually colonizes into the bare ground of severely desertified land as a pioneer species.It is,therefore,expected that A.halodendron will be less dependent on current nutrient uptake through efficient and proficient resorption of nutrients.In this study,we found that averaged nitrogen(N)and phosphorus(P)concentrations in senesced leaves significantly varied from 12.3 and 1.2 mg/g in the shifting sand dune to 15.9 and 1.9 mg/g in the fixed sand dune,respectively,suggesting that foliar N and P resorption of A.halodendron were more proficient in the shifting sand dune.In particular,positive relationships between nutrient concentrations in senesced leaves and soil nutrient availability indicate that A.halodendron in infertile habitats is more likely to manage with a low level of nutrients in senesced leaves,giving this species an advantage in infertile soil.Moreover,foliar N-and P-resorption efficiencies and proficiencies showed limited inter-annual variability although annual precipitation varied greatly among 2007–2009.However,N and P resorption of A.halodendron were not more efficient and proficient than those previously reported for other shrubs,indicating that the pioneer shrub in sand dune environments does not rely more heavily than other plants on the process of resorption to conserve nutrients.Incomplete resorption of nutrients in A.halodendron suggests that senesced-leaf fall would return litter with high quality to the soil,and thereby would indirectly improve soil nutrient availability.The restoration of desertified land,therefore,may be accelerated after A.halodendron pioneers into shifting sand dunes.     

Ejaculation does not contribute to the stress response to electroejaculation in sheep

Electroejaculation procedures (EEPs) provoke stress; nevertheless, ejaculation produces physiological changes similar as those usually used to measure stress responses. The application of EEP to animals that cannot ejaculate—as ewes—may be useful to discriminate the responses induced by ejaculation from those provoked by EEP. The aim was to determine the stress response to EEP in rams and ewes. The EEPs were applied to 10 rams and 10 ewes during the non‐breeding season, and the number of vocalizations, the heart rate, rectal temperature, serum cortisol concentration, biochemical and haematological parameters were measured. Overall, EEP provoked increases in cortisol concentration, glycaemia, rectal temperature and concentration of creatine kinase (all them: p < .0001) as well as relative concentration of granulocytes (p = .003) and absolute granulocyte concentration (p = .0002) in both, rams and ewes. Heart rate, relative concentration of lymphocytes (p = .001), haematocrit (p = .02) and haemoglobin (p = .045) decreased in animals from both genders after EEP. Besides, cortisol (p < .0001), rectal temperature (p = .002) and glycaemia (p = .001) were greater in ewes than rams, and creatine kinase also tended to be greater in ewes than rams (p = .054). On the other hand, the number of animals that vocalized (p = .006), white blood cells (p = .02) and absolute lymphocytes (p = .02) were greater in rams than ewes. The general trends show a similar pattern of stress responses in animals from both genders. Therefore, we concluded that ejaculation does not contribute to the stress response provoked by the EEP. This procedure also provokes muscular damage and probably pain.     

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.     

靖江杉木人工林产量及栽培技术研究

论述了靖江县推广栽植杉木的可行性及其栽培技术,认为杉木能够适应当地气候条件,采取集约措施,年均生长量可达到15m~3/hm~2以上的速生丰产水平。     

国际单位制(SI)的新变化

在新版的《国际单位制（SI）》中,SI单位的含义发生了重大变化,取消了“辅助单位”这一分类类别,此外新增一个具有专门名称的一贯SI导出单位katal。基于上述变化,我国法定计量单位的构成体系也发生了相应变化。     

Effect of diets containing sulfate or chloride-based anionic salts,fed to grazing prepartum dairy cows,on concentrations of Ca in plasma,disease incidence and milk yield

AIMS: To compare the effect of two partial mixed ration diets containing either sulfate or chloride-based anionic salts, fed to grazing prepartum dairy cows, on concentrations of Ca, Mg, P and beta-hydroxybutyrate (BHB) in plasma, disease incidence and milk yield during the early postpartum period.

METHODS: The study was conducted on a seasonal-calving grazing dairy farm located in Benton (MO, USA). In August 2016, two groups of 200 cows were randomly assigned at 30 days before expected parturition to receive either a sulfate or chloride-based anionic diet, to achieve a dietary cation–anion difference (DCAD) of ?25?mEq/kg DM. Cows were fed partial mixed rations to provide 50% of their DM intake, with 50% provided by grazing fescue pasture. Urine samples were collected from 20 cows from each group once a week for 5 weeks until calving for pH assessment. At parturition, 42 cows per group were selected at random and blood samples collected on Days 1, 2, 3 and 7 postpartum. The study continued until 100 cows per group calved. Health events and cumulative milk yield until 30 days postpartum were recorded. Concentrations of Ca, P, and Mg in plasma at Days 1, 2, 3, and 7, and BHB in plasma at Day 7 postpartum were assessed.

RESULTS: Mean urine pH was lower in cows in the chloride than sulfate group (p≤0.06) on four of five sampling occasions. Mean concentrations of Ca in plasma on Day 1 were 2.00 (95% CI=1.94–2.05) and 1.91 (95% CI=1.88–1.97) mmol/L for the chloride and sulfate groups, respectively (p=0.15), and on Day 3 were 2.03 (95% CI=1.97–2.08) and 1.90 (95% CI=1.84–1.96) mmol/L, respectively (p=0.038). Concentrations of Mg, P and BHB in plasma and incidence of diseases postpartum were similar in both groups (p>0.05). There were no cases of clinical hypocalcaemia in either group.

CONCLUSIONS AND CLINICAL RELEVANCE: Prepartum cows fed a partial mixed ration with a negative DCAD containing chloride-based anionic salts and free access to a fescue pasture had lower prepartum urine pH, and higher concentrations of total Ca in plasma during the first week postpartum, than cows receiving a partial mixed ration containing sulfate-based anionic salts.     

Thalidomide pharmacokinetics in sheep

AIM: To determine the half life (T_1/2), time taken to reach maximum plasma concentration (T_max) and maximum plasma concentration (C_max) of thalidomide in sheep following I/V, oral and topical treatment with a single dose of thalidomide.

METHOD: Three groups of 4–6-month-old ram lambs were treated with thalidomide dissolved in dimethylsulphoxide (DMSO). The first group (n=10) was treated I/V with 100?mg thalidomide in 2?mL DMSO; the second group (n=8) received 400?mg thalidomide in 2?mL DMSO orally, and the third group (n=8) had 400?mg thalidomide in 4?mL DMSO applied topically. Plasma samples were collected up to 36 hours after treatment, snap-frozen at ?80°C and analysed for concentrations of thalidomide using high performance liquid chromatography.

RESULTS: Following I/V administration, T_1/2 was 5.0 (SEM 0.4) hours, volume of distribution was 3,372.0 (SEM 244.3) mL/kg and clearance was 487.1 (SEM 46.1) mL/hour.kg. Topical application of 400?mg thalidomide did not increase plasma concentrations. Following oral administration, thalidomide bioavailability was 89%, with T_1/2, T_max, and C_max being 7.2 (SEM 0.8) hours, 3.0 (SEM 0.4) hours and 1,767.3 (SEM 178.1) ng/mL, respectively.

CONCLUSION: Topical administration using DMSO as a solvent did not increase concentrations of thalidomide in plasma. The mean pharmacokinetic parameters determined following oral treatment with 400?mg of thalidomide were similar to those reported in humans receiving a single 400?mg oral dose (T_1/2 7.3 hours; T_max 4.3 hours and C_max 2,820?ng/mL). There is potential for thalidomide to be used as a model for the treatment of chronic inflammatory conditions in sheep, such as Johne's disease, where tumour necrosis factor alpha plays a pathogenic role.