Large-intestinal nematoda in bison

In the Bia?owieza Forest the parasitological autopsy of large intestine of 6 bisons was made at the beginning of winter of 1987-1988, and 9 dissections were made in the latter part of both seasons. Four species of nematodes were found to occur together: Chabertia ovina, Oesophagostomum radiatum, Oe. venulosum and Trichocephalus ovis. At the end of wintering in bisons the invasion of Ch. ovina appeared in high percent of animals, but the intensity of it was low. However, the extensity and intensity of invasion of three remaining species of nematodes distinctly arose. In comparison with bisons in closed reserves, free living bisons assimilated Oe. venulosum and Ch. ovina. It is likely that the winter quarters are the source of invasion. It can be explained by the permanent accumulation of feaces with invasive forms of nematodes, and by feeding bisons on the great amount of hay, in which the invasive forms of nematodes may also occur.     

福州市2003年人体肠道线虫感染调查

1988～1990年首次全国人体寄生虫分布调查,福州市查出的肠道寄生虫多达23种,人群感染率达86.6%[1],居全省首位,属于寄生虫病流行严重的地区之一。13年来,随着人民生活水平的提高,农村饮用水和居住条件改善,施用化肥比例增加,施用人粪比例减少,人群寄生虫感染情况发生变化。为了解目前人体重要寄生虫感染情况,按照《福建省人体重要寄生虫病现状调查实施方案》要求,于2003年对福州市6个县(市、区)中的9个中签点进行了人体肠道线虫感染调查,并与1990年调查资料进行对比分析。1对象与方法1.1调查对象根据中国预防医学科学院全国统一抽样方案,在…     

三种方法体外同步分离培养大鼠肝枯否细胞和星状细胞的比较

目的比较淋巴细胞分离液（LS）、Percoll液（PS）和Nycodenz液（NS）同步分离培养大鼠肝枯否细胞（KC）和星状细胞（HSC）的优缺点。方法①采用链酶蛋白酶E、胶原酶Ⅳ联合原位灌流消化，分别以LS、PS和NS的非连续密度梯度离心法同步分离培养大鼠KC和HSC。②碳素墨汁吞噬试验鉴定KC；α-SMA免疫细胞化学染色法鉴定HSC。③倒置相差显微镜下观测细胞形态，台盼蓝染色显示细胞活性，计数后计算细胞的得率、存活率和纯度。结果体外成功地同步分离培养了KC和HSC；培养的KC吞噬功能明显，而传代HSCα—SMA免疫细胞化学染色阳性者几乎达100％；采用PS或NS体外同步分离KC的细胞得率和纯度均显著高于采用LS分离细胞所得（P〈0．01），而采用NS体外同步分离肝KC的细胞存活率显著高于PS或LS分离细胞的存活率（P〈0．05）；分别采用LS、PS和NS同步分离HSC，三者的细胞存活率逐次升高（P〈0．05或P〈0．01），而使用LS同步分离的细胞虽然细胞得率比较高（P〈0．05），但其细胞纯度较使用PS和NS明显降低（P〈0．05），PS和NS分离获得的HSC得率和纯度均无明显统计学差异。结论采用Percoll液和Nycodenz液体外同步分离培养大鼠肝KC和HSC效果好，且后者的细胞存活率最高。     

Effects of host serum on feeding by Trichostrongylus colubriformis (nematoda)

The effect of host serum on in vitro feeding by Trichostrongylus colubriformis was studied by incubating adult helminths in goat serum containing the dye, Rhodamine B. The amount of dye ingested was determined by fluorometric analysis. Immune serum from goats infected with T. colubriformis suppressed helminth feeding, while normal serum from uninfected goats did not. Suppression of feeding by immune serum increased with the duration of the host's infection. Heat-inactivation (56 degrees C) of immune serum did not affect its suppressive activity. Pre-exposure of worms to immune serum decreased subsequent feeding activity. However, rigorous washing of helminths restored their feeding to levels that were similar to untreated worms. Indirect immunofluorescent studies with immune serum and FITC conjugated rabbit anti-goat IgG demonstrated binding of immunoglobulin to the cuticle, stoma and excretory pore of whole worms. Feeding inhibition of immune serum was associated with IgG1 isotype. Results of the present studies indicated that IgG was responsible for in vitro suppression of T. colubriformis feeding and may be one effector of immunity to T. colubriformis in the goat.     

A new species of nematoda parasite of the cerambicid eucalyptus longhorned borer from Argentina

Artigasia indigena n. sp. is characterized by the cuticle thin, annulated and with spines arranged in regular longitudinal rows from the first ring to the base of medial bulb. The first ring is differentiated with eight spines, the second ring is bigger and without spines, and then a series of small rings with spines come up to the base of medial bulb. Lateral alae absent, stoma short with four thickening cuticle like teeth, excretory pore posterior situated at the beginning of the intestine, V = 67 %, eggs oval with smooth shell, male without spicule, and genital papillae arranged with one pair of preanal papillae and one pair of postanal papillae.     

Telomerase in kinetoplastid parasitic protozoa

We have identified telomerase activity in extracts of three evolutionarily diverse kinetoplastid species: Trypanosoma brucei, Leishmania major, and Leishmania tarentolae. Telomerase activity was initially detected in extracts from insect form cells of all three kinetoplastid species by using a modification of the one-tube telomere repeat amplification protocol [Kim, N., et al. (1994) Science 266, 2011-2015], although better results were subsequently achieved with the two-tube telomere repeat amplification protocol [Autexier, C., Pruzan, R., Funk, W. & Greider, C. (1996) EMBO J. 15, 5928-5935]. The activity in T. brucei extracts was sufficiently robust to enable its detection in a direct assay of telomerase; enzyme processivity was found to be relatively low. The in vitro properties of telomerase suggest a possible templating domain sequence for the telomerase RNA of T. brucei. Telomerase activity is likely to contribute to telomere maintenance in these parasitic organisms and provides a new target for chemotherapeutic intervention.     

Ocular parasitic infection in Thailand

Parasitic infestation is a major health problem in tropical countries. Increasing tourism and the influx of refugees from Southeast Asia demand a greater awareness of ocular parasitology. In Thailand, cysticercosis, gnathostomiasis, and angiostrongyliasis are the three commonest ocular parasitic diseases. No antiparasitic drugs are yet available to treat ocular involvement, and therapeutic success depends upon early and complete surgical removal. Because the eye is the only site at which direct visualization and surgical removal are possible, ocular examination is crucial to diagnosis and treatment.     

Nutritional requirements in parasitic diseases

"Nutritional requirements" means different things in different contexts. Generally, the term refers to national or international standards or allowances of nutrients. Concern here involves the potential need for a change of standards where conditions of disease prevail, because disease increases the nutritional requirements of most individuals. "Nutritional requirements" may also be viewed in terms of food supplies. Analysis of a number of studies indicates that the average growth deficit due to endemic infectious diseases in early life is less than or equal to 20 kcal per day (calculated as 5 kcal/g of tissue). Increased weight gain following treatment of intestinal parasites such as Ascaris lumbricoides or Giardia lamblia provides similar estimates, as does measurement of energy and protein absorption. These values are within normal variance estimates. Sick children do not eat well and apparently do not eat enough on healthy days to correct for the accrued food deficit. Research on nutritional requirements of children needs to focus on management of food resources in entire families.