An epidemiological study of Fasciola hepatica in the Netherlands

Summary

Transmission of F.hepatica under natural conditions was analysed in a three year programme. The variables used were the indirect haemagglutination (IHA) technique, worm establishment in tracer lambs and the population dynamics, infection rate and shedding pattern of Lymnaea truncatula.

It is concluded that fluke eggs, infected snails and metacercariae on herbage can survive the winter in the Netherlands. Metacercarial availability was positively correlated to the amount of rainfall in the grazing period. The role of developed eggs that survive the winter is important, because this results in earlier infections in the herd.

The use of the serological diagnosis method IHA is important to detect F. hepatica infection in an early stage. Use of cellophane paper on floats is a useful method for determining the shedding pattern of cercariae from L. truncatula. It is concluded that collection of metacercariae on cellophane floats, inventarization of L. truncatula and its infection level are useful tools for the prediction of liverfluke infections.     

Nasopharyngeal cryptococcosis

Naturally occurring cryptococcosis in five cats, a dog and a koala is described. Involvement of the nasopharynx was documented in all patients, and nasopharyngeal mass lesions accounted for the major presenting complaints in four. Signs referable to nasopharyngeal disease included snoring, stertor, inspiratory dyspnoea and aerophagia. Diagnoses were made by caudal rhinoscopy using a retroverted flexible endoscope, vigorous orthograde flushing with saline, or at necropsy. Concurrent cryptococcal rhinitis was present in all cases, although involvement appeared limited to the caudal nasal cavity in most cases. Typical signs of nasal cavity disease, such as sneezing and nasal discharge, were often absent. Treatment of nasopharyngeal cryptococcosis should include physical dislodgement or debulking of lesion(s) to provide immediate alleviation of upper airway obstruction, followed by systemic antifungal therapy to eliminate residual infection from the nasal cavity. Infections caused by Cryptococcus neoformans var gattii accounted for a disproportionately large number of these cases.     

Suppression of volcanism during rapid extension in the basin and range province, united states

Continental extension and volcanism are generally thought to be complementary. Stratigraphic and structural data from some highly extended parts of the Basin and Range province reveal instead that rapid extension appears to have suppressed volcanism. This relation may reflect enhanced crystallization of midcrustal magmas during extension resulting from exsolution of magmatic volatiles, increased interaction of magmas with meteoric water, and dispersal of magma into smaller bodies. Some rift environments may thus be characterized by voluminous synextensional plutonism with little or no concomitant volcanism.     

牧草新品种黔草1号高羊茅的选育

黔草1号高羊茅是利用贵州地方野生资源作亲本,采用改良混合选择法,经10余年的选育研究育成的新品种。该品种抗逆性强、适应性广、坪用性好、耐践踏、持续性好、绿期长,返青期比引进品种凌志提前7 d,枯黄期晚3 d;种子成熟期集中,种子平均产量比对照品种高20%以上。适应我国长江中下游低山、丘陵等地区种植,是运动场草坪、环境绿化、生态治理的优良草种。     

周小舟教授治疗肝癌经验

周小舟教授认为肝癌的病因是内因正气亏虚和外因外染疫毒相互作用所致,其主要病机是气虚血瘀,针对主要病机设立芪术抗癌方辨证加减治疗,临床疗效显著;周教授通过实验及临床研究亦初步阐明了芪术抗癌方的作用机制,值得临床借鉴。     

Early Pregnancy Diagnosis by Serum Progesterone and Ultrasound in Sheep Carrying Somatic Cell Nuclear Transfer-Derived Pregnancies

Early pregnancy diagnosis and monitoring play an important role following embryo transfer in sheep. The aims of the current study were to investigate (i) the pattern of serum progesterone profiles in sheep carrying somatic cell nuclear transfer (SCNT)‐derived (clone) pregnancies, and (ii) the frequency of pregnancy loss during development following SCNT embryo transfer. Sheep SCNT embryos were made using standard nuclear transfer techniques. Day 7 embryos were surgically transferred to oestrus‐synchronized recipients (n = 27). As a control, normal fertile ewes (n = 12) were bred by natural breeding. Serum was collected from all the ewes on the day of estrus (day 0 sample), 7 days post‐estrus (day 7 sample) and 19 days post‐estrus (day 19 sample) and every 10 days thereafter until lambing or pregnancy loss occurred. Serum progesterone (P4) was assessed using enzyme immunoassay. Pregnancy was confirmed by ultrasound scanning on day 35 of pregnancy followed by subsequent scanning every 10 days. In control ewes, pregnancy rate on day 35 was 83.3% (10/12), whereas in the ewes that received SCNT embryos, it was 22.2% (6/27; p < 0.05). The day 45 pregnancy rate in the control ewes was 83.3%, whereas in the SCNT embryo recipients it was 11.0% (p < 0.05). Hormone analysis revealed that SCNT embryo recipients exhibited a significantly lower P4 profiles at different time points in pregnancy compared to controls (p < 0.05). This study highlights the use of serum progesterone in combination with ultrasound for the investigation of embryo loss and crucial times during development of normal and SCNT embryos in sheep. Further, the serum P4 levels directly reflect the degree of placental development in these two groups.     

热处理对水牛乳稳定特性的影响

为比较不同热处理条件对水牛乳稳定性的影响,实验采用不同条件热处理后的pH缓冲容量、总溶解固体（total dissolved solids,TDS）、蛋白沉淀量及表观黏度等指标研究杂交高代水牛乳样品。结果表明：与未经处理的水牛乳样品相比,水牛乳经不同条件热处理后,其pH缓冲容量、TDS、蛋白沉淀量及表观黏度皆发生显著变化。其中水牛乳分别在经121℃/15 min和95℃/5 min处理后,其pH缓冲容量、TDS、蛋白沉淀量及表观黏度分别达到最大值和最小值。因此,认为在本实验研究范围内,水牛乳经121℃/15 min及95℃/5 min处理后,对其稳定性影响最大。     

Linkage of downy mildew resistance genes Pd 1 and Pd 2from Allium roylei Stearn in progeny of its interspecific hybrid with onion (A. cepa L.)

Summary Male meiosis of the interspecific hybrid between Allium roylei and A. cepa is undisturbed relative to its parents. Based on meiotic data, A. roylei is concluded to be a closer relative of A. cepa than A. fistulosum. Segregation ratios for downy mildew resistance among BC₁ and F₂ progenies from the F₁ between A. roylei and A. cepa indicate the presence of two dominantly inherited, weakly linked nuclear resistance genes, Pd ₁ and Pd ₂, in A. roylei (recombination frequency 0.32±0.03). Presumably Pd ₁ and Pd ₂are the first genes described in Allium residing in one linkage group. The prospects of exploiting A. roylei in onion breeding seem very promising.