[Changes of IFN-gamma, IL-4 and T cells in Schistosoma japonicum-infected mice after praziquantel treatment].

OBJECTIVE: To investigate the serum levels of IFN-gamma and IL-4, and the dynamic changes of IFN-gamma-specific and IL-4-specific lymphocytes in mice with Schistosoma japonicum infection after treatment by praziquantel. METHODS: Ninety BALB/c mice were randomly divided into three groups (n = 30) named as infection group, treatment group and control group. The mice in treatment group and infection group were infected with (25 +/- 2) S. japonicum cercariae through the abdominal skin. At 6 weeks post-infection, the mice in treatment group were administered orally with praziquantel [300 mg/(kg x d)] for 3 d. At 4, 6, 8 and 12 weeks post-treatment, the mice were weighed, and serum samples were collected. Serum levels of IFN-gamma and IL-4 were measured by ELISA. At the same time, the spleens were aseptically removed to prepare cell suspension, and the counts of IFN-gamma and IL-4 specific lymphocytes were examined by ELISPOT after stimulation of Schistosoma japonicum soluble egg antigen (SEA). RESULTS: From 4 to 12 weeks after praziquantel treatment, the body weight of mice in treatment group were significantly heavier than that of infection group (P < 0.05), but no significant difference was found between treatment group and control group (P < 0.05). At 4 weeks posttreatment, there was no significant difference in serum levels of IFN-gamma and IL-4 between treatment group and infection group (P > 0.05). At 6, 8, and 12 weeks after treatment, the serum levels of IFN-gamma (0.038 +/- 0.013, 0.028 +/- 0.001, and 0.027 +/- 0.007) and IL-4(0.051 +/- 0.020, 0.045 +/- 0.019, and 0.043 +/- 0.016) in treatment group were significantly lower than that of infection group (IFN-gamma: 0.057 +/- 0.004, 0.060 +/- 0.023, and 0.052 +/- 0.017; IL-4: 0.150 +/- 0.014, 0.148 +/- 0.014, and 0.123 +/- 0.017) (P < 0.05). Serum IFN-gamma and IL-4 levels in treatment group and infection group were significantly higher than that of control group (P < 0.05). ELISPOT results showed that at 4, 6 weeks post-treatment, there was no significant difference in the number of IFN-gamma-specific lymphocytes between treatment group and infection group (P > 0.05). While at 8 and 12 weeks after treatment, the IFN-gamma-specific lymphocytes in treatment group (39.9 +/- 22.8 and 38.5 +/- 6.2) were significantly less than that of infection group (141.9 +/- 39.3 and 106.8 +/- 28.6) (P < 0.05). At 4-week post-treatment, the IL-4-specific lymphocytes in treatment group were much more than that of infection group (175.6 +/- 62.3) (P < 0.05), and then began to decline. At 8 and 12 weeks after treatment, the IL-4-specific lymphocytes (111.3 +/- 14.3 and 113.0 +/- 44.2) in treatment group were significantly less than that of infection group (220.3 +/- 107.1 and 208.1 +/- 17.2) (P < 0.05). The IFN-gamma-specific and IL-4-specific lymphocytes in treatment group and infection group were significantly more than that of control group (P < 0.05). CONCLUSION: After praziquantel treatment, the serum levels of IFN-gamma and IL-4 in mice with S. japonicum infection decrease, and the number of IFN-gamma and IL-4 specific lymphocytes reduces.

Visualization of chromosomes in the binucleate intestinal parasite Giardia lamblia.

Mitosis of Giardia lamblia is a complex and rapid event that is poorly understood at the cellular and molecular levels. Therefore, we conducted this study to determine (1) whether the two nuclei have similar or different chromosomes, (2) the number of chromosomes of G. lamblia, and (3) the morphology and karyotype of the chromosomes. Trophozoites of the C2 and WB strains of G. lamblia were grown in modified TYI-S-33 medium at 37°C. The trophozoites were collected, and sample slides were prepared for conventional light and scanning electron microscopy. Light microscopy revealed five pairs of chromosomes. The chromosomes were approximately 0.64-0.94 µm long with a short rod-like shape and were usually arranged in pairs. Scanning electron microscopy yielded similar findings, and 10 chromosomes could be seen in each nucleus. Thus, the chromosome number of G. lamblia is 2n = 10. Chromosomes in pair 1 are submetacentric chromosomes, while pairs 2-5 are telocentric chromosomes. The present study shows that G. lamblia trophozoites have typical condensed chromosomes during mitosis and contains five pairs of chromosomes. The karyogram shows good fit to the formula 2n = 10 = 2sm + 8t revealed by scanning electron microscopy.

[Construction of GCV-specific hammerhead ribozyme recombinant vector of alpha-8 giardin in Giardia lamblia].

OBJECTIVE: To construct a GCV-ribozyme recombinant vectors of alpha-8 giardin in Giardia lamblia. METHODS: The secondary structure of alpha-8 giardin mRNA (GenBank Accession No. AY781323) was analyzed with the RNA draw software. According to the proportion of G:C and principles of designing hammerhead ribozyme, suitable ribozyme cleavage points were chosen. A specific antisense-hammerhead ribozyme (H8) was designed and synthesized. The ribozyme was cloned into Giardia canis virus (GCV) vector to construct a recombinant viral vector-pGCV634/H8/1423. The vector was linearized and transcript into the trophozoites of G. lamblia by electroporation method. The alpha-8 giardin mRNA level of the transfectants and normal trophozoites were analyzed 24 h after electroporation by RT-PCR. RESULTS: The recombinant vector of GCV-specific hammerhead ribozyme of alpha-8 giardin in Giardia lamblia (pGCV634/H8/ 1423) was constructed. RT-PCR assays showed the ribozyme (H8) mRNA can be detected 24h after transfection and alpha-8 giardin mRNA was cleaved effectively by ribozyme (H8) intracellularly. CONCLUSION: pGCV634/H8/1423 can transfect Giardia trophozoites and cleave mRNA of alpha-8 giardin intracellularly.

Giardia lamblia: intracellular localization of alpha8-giardin.

Alpha8-giardin (α8-giardin) is a member of the multi-gene α-giardin family in the intestinal parasitic protozoan, Giardia lamblia. This gene family shares an ancestry with the annexin super family, whose common characteristic is calcium dependent binding to membranes that contain acidic phospholipids. In the present study, the antigenicity, hydrophilicity, flexibility, surface probability, and secondary structure of α8-giardin amino acids were predicted by bioinformatics applications. A specific anti-peptide antiserum, anti-P3, was used to determine the intracellular location of α8-giardin with confocal immunofluorescence microscopy and immunoelectron microscopy. The results indicated that α8-giardin was located on the plasma membrane and flagella, but not on the ventral disk. Reduction of α8-giardin transcript levels by ribozyme-mediated cleavage decreased trophozoite motility and growth rate, indicating the functional importance of α8-giardin to Giardia trophozoite biology.

Identification of the nucleoli of Giardia lamblia with TEM and CFM.

Giardia species are flagellated parasites of vertebrates and belong to the diplomonads, most of which have two nuclei. These organisms were classified among the earliest branching eukaryotes on the basis of small subunit rDNA sequences and their lack of many canonical organelles. However, some of these organelles have subsequently been identified in rudimentary form, such as Golgi that become apparent during encystation. One of the "missing" organelles has been the nucleolus, the site of rRNA synthesis, since it was not identified in earlier ultrastructural studies. In the current study, we visualized in-vitro-grown Giardia lamblia trophozoites by transmission electron microscopy and laser scanning confocal microscopy. We found that each of the two nuclei contains a single small and deeply stained granular nucleolus, thus demonstrating that Giardia does indeed have nucleoli.

The effects of dihydroartemisinin on Giardia lamblia morphology and cell cycle in vitro.

Several anti-Giardia drugs, such as metronidazole, tinidazole, mebendazole, albendazole and furazolidone, are usually effective but have severe side effects and potential toxicity. An urgent need exists for more effective and less toxic agents that can act against this protozoan. For this purpose, the effects of dihydroartemisinin (DHA) on Giardia lamblia were investigated in vitro. Axenically grown G. lamblia trophozoites were treated with DHA (LD(50) = 200 microg/mL) at different time intervals. The morphological and ultrastructural changes of the treated trophozoites were observed by both light and transmission electron microscopy (TEM). Changes in the cell cycle of the treated cells were observed by flow cytometry. By light microscopy, we observed that DHA-treated trophozoites were detached from the wall of the culture tube and shown bradypraxia and bubbles in the dorsal and ventral surfaces. Ultrastructural observations by TEM revealed that DHA promoted modifications of the cell shape, pronounced dorsal vesiculation, plasma membrane blebbing, disaggregation of ribosomes, depletion of cytoplasmic matrix and heavy deposition of electron-dense precipitates on the cytoplasm and nucleus. The main changes observed in the treated group included the following: (1) trophozoites were rounder in shape and the endoplasmic reticulum was dilated, (2) enlarged trophozoites contained lamella structures and deformed nuclei, (3) trophozoites displayed dissolved cytoplasm with large vacuole spaces or decreased cytoplasmic volume, (4) adhesive disc bubbles or the lamella structures of cytoplasm were clearly observed, and (5) cell division was arrested. Using microscopy and cytometry techniques, we demonstrate that changes in G. lamblia morphology and cell cycle state were induced by DHA.

[Facial Demodex infection among college students in Tangshan].

A survey indicated that the prevalence of Demodex infection among 512 college students in Tangshan was 36.3% (186/512), that of males and females was 39.3% (81/206) and 34.3% (105/306) respectively (P>0.05). The infection of Demodex folliculorum accounted for 82.3% (153/186), followed by D. brevis (7.5%, 14/186) and mixed infection (10.2%, 19/186). The prevalence was 47.0% (93/198) in subjects with oily skin, 26.6% (37/139) in those with dry skin, and 33.9% (56/165) in mixed-type skin (P<0.05). Subjects with facial diseases (62.0%, 75/121), such as rosacea and acne, were more likely to be infected with Demodex than those with healthy skin (27.6%, 80/290) (P<0.05). Prevalence in those lived in humid environment (67.9%, 95/140) was higher than those lived in the desiccating environment (24.5%, 91/372) (P<0.05).

[Entamoeba gingivalis infection among college students in Tangshan].

OBJECTIVE: To investigate the prevalence of Entamoeba gingivalis infection in college students in Tangshan, and analyze the relationship between the infection and human behaviors. METHODS: 551 students of grades 1-3 from six colleges in Tangshan received questionnairing, which covered the oral health state, teeth-brushing, xylitol gum-chewing, diet fondness, and smoking. Specimens were taken from the tooth surface of the lesion or fouling materials by using disinfected toothpicks and the smears were observed microscopically to examine Entamoeba gingivalis infection. RESULTS: The prevalence of Entamoeba gingivalis infection was 28.3% (156/551), 30.4% (55/181) and 24.6% in males and females (91/370) respectively (chi2=2.09, P>0.05). The prevalence in students with or without oral disorders was 41.2% (84/204) and 20.8% (72/347) respectively, with a significant statistical difference (chi2=26.41, P<0.01); it was 22.5% (53/236) and 32.7% (103/315) among students who cleaned their teeth regularly or irregularly (chi2=6.97, P<0.01); it was 18.3% (17/93) and 30.4% (139/458) among those usually with or without chewing xylitol gum (chi2=5.55, P<0.05). CONCLUSION: Entamoeba gingivalis infection is common in the college students in Tangshan and it has a close relation to the oral hygiene habits and the presence of oral disorders.

[The injury of metronidazole on morphology of Giardia lamblia in vitro].

Trophozoites of Giardia lamblia were axenically cultivated with modified TYI-S-33 medium contained 500 microg/ml metronidazole (12h LC50). The morphology of drug-treated trophozoites was observed with light and electron micro-scopes at 2, 4, 8, 12 h respectively. The light microscopy revealed that the trophozoites treated with MTZ showed swollen, detached from the wall of the culture tube, and were with vacuoles in the cytoplasm. Movement of the flagella become slowly or stopped. Electronic microscopy showed that the trophozoites were swollen and deformed; lots of vacuoles were seen in the cytoplasm; the contents of cytoplasm were depleted and the nuclei deformed. This study indicated that MTZ has injured the morphology of G. lamblia.

[Human parasitology teaching in the 21st century].

Multimedia techniques were applied in parasitological teaching and experimental practices. In order to strengthen the practical ability of the undergraduate students, reform was conducted including a prioritization of the teaching content, use of series micro-slides and video show, etc.

The mediating role of emotional intelligence between negative life events and psychological distress among nursing students: A cross-sectional study.

BACKGROUND: Previous studies have highlighted that negative life events and emotional intelligence are significant predictors of mental health. However, whether emotional intelligence mediates the relationship between negative life events and psychological distress among nursing students have not been given adequate attention. OBJECTIVES: To explore the relationship among negative life events, emotional intelligence and psychological distress and to examine the mediating role of emotional intelligence in psychological distress among Chinese nursing students. DESIGN: A cross-sectional survey using convenience sampling. SETTINGS AND PARTICIPANTS: A total of 467 nursing students who were enrolled in a university in mainland of China. METHODS: A structured questionnaire was administered from September-November in 2013 to participants who consented to participate in the study. Independent variables were personal variables, emotional intelligence and negative life events. Outcome variable was psychological health. The means and standard deviations were computed. Student's t-test and one-way analysis of variance (ANOVA) were performed, to test the differences among the demographic characteristics on the psychological distress scores. Pearson correlation analyses and hierarchical regression analyses were performed. RESULTS: Negative life events were positively associated with psychological distress. Emotional intelligence was negatively associated with psychological distress and negative life events. Emotional intelligence mediated the relationship between negative life events and psychological distress. CONCLUSIONS: The findings support the theory of Salovey and his colleagues, and provide evidence for emotional intelligence as a factor that buffers effects of negative life events on psychological distress.

[Effect of dihydroartemisinin on ultrastructure of Giardia lamblia in vitro].

OBJECTIVE: To study the in vitro effect of dihydroartemisinin (DHA) on Giardia lamblia. METHODS: Trophozoites of G. lamblia were cultivated with modified TYI-S-33 medium that contains dihydroartemisinin (DHA). The trophozoites were morphologically observed respectively with light and electron microscopes after treated with the drug. RESULTS: The mortality increased with the prolongation of the time of the drug action and the increase of drug concentration (P<0.01). While at the same concentration of 100 microg/ml, the mortality increased from 46.6% for 12 h to 100% for 24 h (P<0.05). For 12 h, the mortality of G. lamblia was from 46.6% at concentration of 100 microg/ml to 100% at 200microg/ml. Under optical microscope, deformation and swelling of the parasites were observed when treated with DHA for 12, 24 and 48 h. Movement of the flagella became slow or stopped. Under electron microscope, the trophozoites were swollen and deformed, vacuoles were seen in the cytoplasm, and the cell membrane ruptured and fell off. The cytoplasm protrusions appeared on the surface of the plasma membrane. The adhesive disc changed into large bubbles and the perinuclear space became wider and the deformed nucleus was seen. CONCLUSION: DHA shows a strong impairment on the plasma membrane and cytoskeleton of Giardia lamblia.

Co-circulation of Hantaan, Kenkeme, and Khabarovsk Hantaviruses in Bolshoy Ussuriysky Island, China.

Hemorrhagic fever with renal syndrome (HFRS) was first recognized in far eastern Asia in the 1930s, and has been highly prevalent in this region ever since. To reveal the molecular epidemiology of hantaviruses in this region, a total of 374 small mammals (eight species of rodents and one species of shrew) were captured in the Chinese part of the Bolshoy Ussuriysky Island (Heilongjiang Province). Hantavirus sequences were recovered from three striped field mice (Apodemus agrarius), 11 Maximowicz's voles (Microtus maximowiczii), and one flat-skulled shrew (Sorex roboratus). Genetic and phylogenetic analysis revealed the presence of three viruses: Hantaan virus (HTNV), Khabarovsk virus (KHAV), and Kenkeme virus (KKMV). HTNV sequences recovered from A. agrarius were closely related to those identified in Apodemus mice from the surrounding areas, while a new lineage of KHAV was present in M. maximowiczii. Additionally, while the viral sequences recovered from one flat-skulled shrew were most closely related to KKMV, their divergence to the prototype strain suggests that they represent a new viral subtype. Overall, these results suggest that Bolshoy Ussuriysky Island harbors considerable hantavirus diversity.

Toll-like receptor 5 agonism protects mice from radiation pneumonitis and pulmonary fibrosis.

Radiation pneumonitis and pulmonary fibrosis are the main complications with radiotherapy for thoracic neoplasms, directly limiting the efficient dose in clinical application and currently there are few medicines that effectively function as radioprotectants. However, a TLR5 agonist, CBLB502, was confirmed to have protective efficacy against hematopoietic and gastrointestinal radiation syndromes in mice and primates. This study points to a new direction for protection against thoracic radiation-induced pulmonary syndromes and skin injury by CBLB502. We utilized the TUNEL assay, pathological analysis and immunohistochemistry to obtain evidence that CBLB502 could alleviate the occurrence of radiation pneumonitis and pulmonary fibrosis as well as radiation- induced skin injury. It may thus play a promising role in facilitating clinical radiotherapy of thoracic neoplasms.

Construction and characterization of a full-lengh cDNA library from non-fresh Giardia lamblia.

OBJECTIVE: To construct rapidly a full-length cDNA library from nanogram amounts total RNA of Giardia lamblia (G. lamblia) trophozoites stocked in RNA stabilization reagent. METHODS: Total RNA of Giardia was extracted using Trizol reagent. A full-length cDNA library of G. lamblia trophozoites was constructed by a long-distance PCR (LD-PCR) method. The recombinant rate and the coverage rate of full-length clones of the library were evaluated. The inserted fragments were identified and sequenced by PCR amplification. RESULTS: The titer of cDNA library was 3.85 × 10(7) pfu/mL. The length of inserted fragments ranged from 0.4 to 2.5 kb, and the recombination efficiency accounted for 100% (20/20). The coverage rate of full-length clones is high (17/20). CONCLUSIONS: The RNA stabilization reagent may be used to fix the cells and prevent the RNA in cells even though delivered under normal atmospheric temperature. The long-distance PCR can be used to construct a full-length cDNA library rapidly and it needs less RNA than the traditional method from mRNA.