A Synergistic Combination of AuNRs and C Dots as a Multifunctional Material for Ice Recrystallization Inhibition and Rapid Rewarming.

Robust platforms and advanced biocompatible materials having diverse performances are in tremendous demand for cryopreservation of biocells, which are greatly limited by the crystallization, formation, and growth of ice crystals. The fickle structure and the arduous extraction process of modern attainable antifreezing proteins cause fatal cryoinjury of the cells making it challenging to develop anti-icing materials. Thus, designing Au colloids is an effective way to combat cell-damaging concerns during the ice freezing-thawing process. Herein, we propose an emerging biomimetic hybrid nanomaterial (AuNR@SiO2-CDs) prepared by combining the photoheating and rewarming controlling characteristics of carbon dots (CDs) and gold nanorods (AuNRs), respectively, via a SiO2 scaffold that has an optimal aspect ratio of ∼4.4. The performance of the material is applied in the freezing and resuscitation of Hela cells. The typical linkage between the AuNR and CDs not only retains the stable structure but also possesses the symmetric functional characteristics of affirmative cryoprotectant materials and sustained low cytotoxicity of cell viability >90%. The cell recovery rate of the Hela cell is significantly improved to ∼60%, which is propped up to >4% higher by the laser irradiation dose. The above hybrid material is paving a path toward novel bionic antifreezing proteins and is envisioned for ice recrystallization inhibition and rapid rewarming.

Spatial Analysis of Schistosomiasis in Hunan and Jiangxi Provinces in the People's Republic of China.

Understanding the spatial distribution of schistosome infection is critical for tailoring preventive measures to control and eliminate schistosomiasis. This study used spatial analysis to determine risk factors that may impact Schistosoma japonicum infection and predict risk in Hunan and Jiangxi Provinces in the People's Republic of China. The study employed survey data collected in Hunan and Jiangxi in 2016. Independent variable data were obtained from publicly available sources. Bayesian-based geostatistics was used to build models with covariate fixed effects and spatial random effects to identify factors associated with the spatial distribution of infection. Prevalence of schistosomiasis was higher in Hunan (12.8%) than Jiangxi (2.6%). Spatial distribution of schistosomiasis varied at pixel level (0.1 × 0.1 km), and was significantly associated with distance to nearest waterbody (km, ß = -1.158; 95% credible interval [CrI]: -2.104, -0.116) in Hunan and temperature (°C, ß = -4.359; 95% CrI: -9.641, -0.055) in Jiangxi. The spatial distribution of schistosomiasis in Hunan and Jiangxi varied substantially and was significantly associated with distance to nearest waterbody. Prevalence of schistosomiasis decreased with increasing distance to nearest waterbody in Hunan, indicating that schistosomiasis control should target individuals in close proximity to open water sources as they are at highest risk of infection.

A case of severe hookworm infection. / 临床极重症钩虫感染1例.

With the improvement of sanitation, the infection rate of hookworm is greatly reduced and the severe infected case is rarely reported. Combined morphological and molecular biological examinations, a severe hookworm infection patient was diagnosed in Department of Laboratorial Examination, Quanzhou First Affiliated Hospital of Fujian Medical University. The morphological methods such as direct fecal smear microscopy, saturated brine flotation and hookworm larvae culture methods were used to identify the eggs and larvae from stool samples of the patient. There were a large number of hookworm eggs in patient's stool samples, and the average count was 60 840 per gram by modified Kato method, which belonged to severe hookworm infection. Meanwhile, to distinguish the hookworm species, the semi-nested RT-PCR assay was employed to detect hookworm internal transcribed spacer series from eggs in patient's stool samples, and the result showed that the hookworm species was confirmed to be Necator americanus.

Schistosomiasis in the People's Republic of China - down but not out.

Schistosomiasis has been subjected to extensive control efforts in the People's Republic of China (China) which aims to eliminate the disease by 2030. We describe baseline results of a longitudinal cohort study undertaken in the Dongting and Poyang lakes areas of central China designed to determine the prevalence of Schistosoma japonicum in humans, animals (goats and bovines) and Oncomelania snails utilizing molecular diagnostics procedures. Data from the Chinese National Schistosomiasis Control Programme (CNSCP) were compared with the molecular results obtained.Sixteen villages from Hunan and Jiangxi provinces were surveyed; animals were only found in Hunan. The prevalence of schistosomiasis in humans was 1.8% in Jiangxi and 8.0% in Hunan determined by real-time polymerase chain reaction (PCR), while 18.3% of animals were positive by digital droplet PCR. The CNSCP data indicated that all villages harboured S. japonicum-infected individuals, detected serologically by indirect haemagglutination assay (IHA), but very few, if any, of these were subsequently positive by Kato-Katz (KK).Based on the outcome of the IHA and KK results, the CNSCP incorporates targeted human praziquantel chemotherapy but this approach can miss some infections as evidenced by the results reported here. Sensitive molecular diagnostics can play a key role in the elimination of schistosomiasis in China and inform control measures allowing for a more systematic approach to treatment.

Voltage-Stabilizer-Grafted SiO2 Increases the Breakdown Voltage of the Cycloaliphatic Epoxy Resin.

Cycloaliphatic epoxy (CE) resin plays a vital role in insulation equipment due to its excellent insulation and processability. However, the insufficient ability of CE to confine electrons under high voltage often leads to an electric breakdown, which limits its wide applications in high-voltage insulation equipment. In this work, the interface effect of inorganic nano-SiO2 introduces deep traps to capture electrons, which is synergistic with the inherent ability of the voltage stabilizer m-aminobenzoic acid (m-ABA) to capture high-energy electrons through collision. Therefore, the insulation failure rate is reduced owing to doping of the functionalized nanoparticles of the m-ABA-grafted nano-SiO2 (m-ABA-SiO2) into the CE. It is worth noting that the breakdown field strength of this m-ABA-SiO2/CE reaches 53 kV/mm, which is 40.8% higher than that of pure CE. In addition, the tensile strength and volume resistivity of m-ABA-SiO2/CE are increased by 29.1 and 140%, respectively. Meanwhile, the glass transition temperature was increased by about 25 °C and reached 213 °C. This work proves that the comprehensive performance of CE-based nanocomposites is effectively improved by m-ABA-SiO2 nanoparticles, showing great application potential in high-voltage insulated power equipment.

Bioinformatics analysis of epitope-based vaccine design against the novel SARS-CoV-2.

BACKGROUND: An outbreak of infection caused by SARS-CoV-2 recently has brought a great challenge to public health. Rapid identification of immune epitopes would be an efficient way to screen the candidates for vaccine development at the time of pandemic. This study aimed to predict the protective epitopes with bioinformatics methods and resources for vaccine development. METHODS: The genome sequence and protein sequences of SARS-CoV-2 were retrieved from the National Center for Biotechnology Information (NCBI) database. ABCpred and BepiPred servers were utilized for sequential B-cell epitope analysis. Discontinuous B-cell epitopes were predicted via DiscoTope 2.0 program. IEDB server was utilized for HLA-1 and HLA-2 binding peptides computation. Surface accessibility, antigenicity, and other important features of forecasted epitopes were characterized for immunogen potential evaluation. RESULTS: A total of 63 sequential B-cell epitopes on spike protein were predicted and 4 peptides (Spike315-324, Spike333-338, Spike648-663, Spike1064-1079) exhibited high antigenicity score and good surface accessibility. Ten residues within spike protein (Gly496, Glu498, Pro499, Thr500, Leu1141, Gln1142, Pro1143, Glu1144, Leu1145, Asp1146) are forecasted as components of discontinuous B-cell epitopes. The bioinformatics analysis of HLA binding peptides within nucleocapsid protein produced 81 and 64 peptides being able to bind MHC class I and MHC class II molecules respectively. The peptides (Nucleocapsid66-75, Nucleocapsid104-112) were predicted to bind a wide spectrum of both HLA-1 and HLA-2 molecules. CONCLUSIONS: B-cell epitopes on spike protein and T-cell epitopes within nucleocapsid protein were identified and recommended for developing a protective vaccine against SARS-CoV-2.

Multi-layer-stacked Co9S8 micro/nanostructure directly anchoring on carbon cloth as a flexible electrode in supercapacitors.

Rational design and synthesis of electrode materials containing uniformly stacked lamella structures with high surface areas are attractive for efficient storage of electrochemical energy. In this work, Co9S8 clusters with a uniformly stacked lamella structure was directly anchored onto carbon cloth (CC) by an easy-to-implement chemical solution processing method, which involves the homogeneous growth of the CoCO3 precursor, promoting the formation of nanosheets during the subsequent sulfurization process. Due to the conductive substrate (CC) and special multi-layer micro/nanostructure (Co9S8), the flexible Co9S8/CC electrode, which can be tailored, bent and twisted arbitrarily without affecting its electrochemical properties, also exhibits excellent electrochemical properties with a high specific capacitance (1475.4 F g-1 at 1 A g-1), a good rate capacity (80.2% retention at 20 A g-1) and excellent cycling stability (92.9% retention over 5000 cycles). In addition, the assembled solid-state asymmetric supercapacitor device containing the fabricated Co9S8 as the positive electrode and activated carbon as the negative electrode, also exhibits a high energy density of 20.3 W h kg-1 at a power density of 22 796.1 W kg-1 and a high energy density of 33.2 W h kg-1 at a power density of 817.9 W kg-1. Because of its good electrochemical properties and flexibility, the flexible Co9S8/CC electrode material is very promising to be used in flexible supercapacitors and wearable electronic technology.

Prime-Boost Vaccine Regimen for SjTPI and SjC23 Schistosome Vaccines, Increases Efficacy in Water Buffalo in a Field Trial in China.

Schistosomiasis remains a serious zoonotic disease in China and the Philippines. Water buffalo and cattle account for the majority of transmission. Vaccination of water buffalo is considered a key strategy to reduce disease prevalence. Previously, we showed that vaccination of water buffalo with SjC23 or SjCTPI plasmid DNA vaccines, induced 50% efficacy to challenge infection. Here, we evaluated several parameters to determine if we can develop a two dose vaccine that maintains the efficacy of the three dose vaccine. We performed four trials evaluating: (1) lab produced vs. GLP grade vaccines, (2) varying the time between prime and boost, (3) the influence of an IL-12 adjuvant, and (4) a two dose heterologous (DNA-protein) prime-boost. We found the source of the DNA vaccines did not matter, nor did increasing the interval between prime and boost. Elimination of the IL-12 plasmid lowered homologous DNA-DNA vaccine efficacy. A major finding was that the heterologous prime boost improved vaccine efficacy, with the prime-boost regimen incorporating both antigens providing a 55% reduction in adult worms and 53% reduction in liver eggs. Vaccinated buffalo produced vaccine-specific antibody responses. These trials suggest that highly effective vaccination against schistosomes can be achieved using a two dose regimen. No adjuvants were used with the protein boost, and the potential that addition of adjuvant to the protein boost to further increase efficacy should be evaluated. These results suggest that use of these two schistosome vaccines can be part of an integrated control strategy to reduce transmission of schistosomiasis in Asia.

[Cp*RhIII ]/Ionic Liquid as a Highly Efficient and Recyclable Catalytic Medium for C-H Amidation.

A [Cp*RhIII ]-catalyzed direct C-H amidation is carried out in ionic liquid. Both C(sp2 )-H bonds of (hetero)arenes and alkenes and unactivated C(sp3 )-H bonds can be easily amidated with high functional-group tolerance and excellent yields under these conditions. Notably, using [Cp*RhIII ]/[BMIM]BF4 (BMIM=1-butyl-3-methylimidazolium) as the green and recyclable medium is environmentally benign, in light of characteristics such as the reusability of the expensive rhodium catalyst, avoidance of highly toxic organic solvents, and mild reaction conditions, as well as a short reaction time.

Rhodium-Catalyzed Direct C-H Bond Cyanation in Ionic Liquids.

A Cp*Rh(III)/IL-based direct C-H bond cyanation system was developed for the first time. The system is a mild, efficient, and recyclable method for the synthesis of aryl nitriles. Many different directing groups can be used in this cyanation, and the reaction tolerates a variety of functional groups.

Dynamic mapping of spontaneously produced H2S in the entire cell space and in live animals using a rationally designed molecular switch.

Hydrogen sulfide (H2S) is a key signaling molecule in the cytoprotection, vascular mediation and neurotransmission of living organisms. In-depth understanding of its production, trafficking, and transformation in cells is very important in the way H2S mediates cellular signal transductions and organism functions; it also motivates the development of H2S probes and imaging technologies. A fundamental challenge, however, is how to engineer probes with sensitivity and cellular penetrability that allow detection of spontaneous production of H2S in the entire cell space and live animals. Here, we report a rationally designed molecular switch capable of accessing all intracellular compartments, including the nucleus, lysosomes and mitochondria, for H2S detection. Our probe comprised three functional domains (H2S sensing, fluorescence, and biomembrane penetration), could enter almost all cell types readily, and exhibit a rapid and ultrasensitive response to H2S (≤120-fold fluorescence enhancement) for the dynamic mapping of spontaneously produced H2S as well as its distribution in the whole cell. In particular, the probe traversed blood/tissue/cell barriers to achieve mapping of endogenous H2S in metabolic organs of a live Danio rerio (zebrafish). These results open-up exciting opportunities to investigate H2S physiology and H2S-related diseases.

Synthesis of CHF2-substituted 3-azabicyclo[3.1.0]hexanes by photochemical decomposition of CHF2-pyrazolines.

A practical synthesis of CHF2-substituted 3-azabicyclo[3.1.0]hexanes was developed for the first time. The key step was photochemical decomposition of CHF2-substituted pyrazolines. This protocol has the advantages of simple operation, and mild conditions, as well as excellent functional group tolerance, giving the desired products in moderate to excellent yields.

Field evaluation of a recombinase polymerase amplification assay for the diagnosis of Schistosoma japonicum infection in Hunan province of China.

BACKGROUND: Current diagnostic methods for Schistosoma japonicum infection are insensitive for low-density infections. Therefore, a new diagnostic assay based on recombinase polymerase amplification (RPA) technology was established and assessed for field applification. METHODS: The S.japonicum RPA assay was developed to target highly repetitive retrotransposon SjR2 gene of S japonicum, and its sensitivity and specificity were assessed by serial dilution of S. japonicum genomic DNA and other related worm genomic DNA respectively. The RPA diagnostic validity was first evaluated in 60 fecal samples from healthy people and patients, and then compared with other diagnostic tests in 200 high-risk individuals living in endemic areas. RESULTS: The real time RPA assay could detect 0.9 fg S. japonicum DNA within 15 min and distinguish S. japonicum from other worms. The validity analysis of RPA for the detection of S. japonicum in stool samples from 30 S. japonicum-infected patients and 30 healthy persons indicated 100% sensitivity and specificity. When testing 200 fecal or serum samples from a high-risk population, the percentage sensitivity of RPA was 100%, whereas that of indirect hemagglutination assay (IHA) and enzyme-linked immunosorbent assay (ELISA) were 80.3% and 85.2% respectively. In addition, the RPA presented better consistency with the stool-based tests than IHA and ELISA. Overall, the RPA was superior to other detection methods with respect to detection time, sensitivity, and convenience. CONCLUSIONS: This is the first time we applied the RPA technology to the field evaluation of S. japonicum infection. And the results suggest that RPA-based assays can be used as a promising point-of-care test for the diagnosis of schistosomiasis.

Recombinase polymerase amplification combined with a lateral flow dipstick for rapid and visual detection of Schistosoma japonicum.

BACKGROUND: With the continuous decline in prevalence and intensity of Schistosoma japonicum infection in China, more accurate and sensitive methods suitable for field detection become much needed for schistosomiasis control. Here, a novel rapid and visual detection method based on the combination of recombinase polymerase amplification (RPA) and lateral flow dipstick (LFD) was developed to detect S. japonicum DNA in fecal samples. RESULTS: The LFD-RPA assay targeting SjR2 could detect 5 fg S. japonicum DNA, which was identical to qPCR and real-time RPA assay, and showed no cross-reaction with other parasites. The detection could be finished within 15-20 min at a wide temperature range (25-45 °C), and the results could be visualized by naked eye. The diagnostic validity of LFD-RPA assay was further assessed with 14 fecal samples of infected patients diagnosed by Kato-Katz method and 31 fecal samples of healthy persons, and compared with that of Enzyme-linked immunosorbent assay (ELSIA) and Indirect Hemagglutination Assay (IHA). The LFD-RPA assay showed 92.68 % sensitivity, 100 % specificity and excellent diagnostic agreement with the gold standard Kato-Katz test (k = 0.947, Z = 6.36, P < 0.001), whereas ELISA showed 85.71 % sensitivity, 93.55 % specificity, and substantial diagnostic agreement (k = 0.793, Z = 5.31, P < 0.001), and IHA showed 78.57 % sensitivity, 83.87 % specificity, and moderate diagnostic agreement (k = 0.600, Z = 4.05, P < 0.001), indicating that the LFD-RPA was much better than the traditional methods. CONCLUSIONS: The LFD-RPA assay established by us is a sensitive, specific, rapid and convenient method for the diagnosis of schistosomiasis, and shows a great potency in field application.

An ultra-sensitive assay targeting the circulating anodic antigen for the diagnosis of Schistosoma japonicum in a low-endemic area, People's Republic of China.

The downward trend in prevalence and intensity of Schistosoma japonicum infection in the People's Republic of China (P.R. China) has reached a level where accurate methods are required for monitoring the national schistosomiasis control programme and to verify whether transmission has been interrupted. We have assessed the prevalence of active S. japonicum infection by use of an up-converting phosphor lateral-flow (UCP-LF) assay for determination of circulating anodic antigens (CAA) in urine and serum, and compared the findings with those of the Kato-Katz technique for egg detection in stool and an immunohaemagglutination assay (IHA) for specific antibodies in serum. The study was carried out in three villages located in a remaining S. japonicum-endemic area in P.R. China. Overall, 423 individuals were investigated by Kato-Katz, 395 by IHA, 371 with the UCP-LF CAA assay adapted for urine and 178 with the UCP-LF CAA assay applied on serum. The IHA showed the highest number of positive results (n=107, 27.1%). The UCP-LF CAA urine assay detected 36 CAA positives (9.7%) and the serum-based CAA assay 21 positives (11.8%). The Kato-Katz technique revealed only six positive stool samples (1.4%). Among those 166 individuals with complete data records, sensitivities of the different assays were determined versus a combined 'gold' standard, showing the highest sensitivity for the urine CAA assay (93%), followed by the serum CAA (73%) and IHA (53%), whilst triplicate Kato-Katz thick smears had a very low sensitivity (13%). Serum CAA concentrations were about 10-fold higher than in urine and were significantly correlated. Highest prevalences as determined by CAA were found in older age groups (>40 years). Half of the CAA- or egg-positive cases were negative for antibodies by IHA, thereby revealing an important obstacle for the effectiveness of the current schistosomiasis control and elimination efforts. The significantly higher prevalence of active schistosome infections as shown by the urine and serum UCP-LF CAA assays has implications for the national control and elimination programme in P.R. China, particularly in respect to case-finding and intervention strategies.

[Analysis of epidemiological characteristics of advanced schistosomiasis in Hu-nan province, 2012].

OBJECTIVE: To understand the epidemiological characteristics of patients with advanced schistosomiasis in Hunan Province, so as to provide the evidence for formulating the advanced schistosomiasis prevention strategies and measures. METHODS: The data of advanced schistosomiasis patients were collected and analyzed retrospectively with the cross section research method and description method in Hunan Province, 2012. RESULTS: There were 5 722 advanced schistosomiasis patients in Hunan Province, and among them, 4 112 patients were male (71.86%), and 1610 were female (28.14%). Totally 5311 patients came from the schistosomiasis endemic areas (92.82%) and 411 patients from non-schistosomiasis endemic areas (7.18%). The prevalence rate of advanced schistosomiasis was 8.46/10,000. The mean age of advanced schistosomiasis patients was 60.30 +/- 11.63 years, and the youngest was 17 years old and the oldest 92 years old. In the age composition of advanced schistosomiasis patients, the greatest number of cases was in the 60-70 years age group (32.72%). There were 3 595 cases of ascites type (62.83%), 2107 cases of splenomegaly type (36.82%), 11 cases of dwarf type (0.16%), and 11 cases of colon proliferation type (0.35%). CONCLUSION: The prevalence rate of advanced schistosomiasis is relatively stable in Hunan Province, and the age of the patients showed an old aging trend. The salvation of advanced schistosomiasis patients in non-endemic areas should be strengthened.

Local immune responses of the Chinese water buffalo, Bubalus bubalis, against Schistosoma japonicum larvae: crucial insights for vaccine design.

Asian schistosomiasis is a zoonotic parasitic disease infecting up to a million people and threatening tens of millions more. Control of this disease is hindered by the animal reservoirs of the parasite, in particular the water buffalo (Bubalus bubalis), which is responsible for significant levels of human transmission. A transmission-blocking vaccine administered to buffaloes is a realistic option which would aid in the control of schistosomiasis. This will however require a better understanding of the immunobiology of schistosomiasis in naturally exposed buffaloes, particularly the immune response to migrating schistosome larvae, which are the likely targets of an anti-schistosome vaccine. To address this need we investigated the immune response at the major sites of larval migration, the skin and the lungs, in previously exposed and re-challenged water buffaloes. In the skin, a strong allergic-type inflammatory response occurred, characterised by leukocyte and eosinophil infiltration including the formation of granulocytic abscesses. Additionally at the local skin site, interleukin-5 transcript levels were elevated, while interleukin-10 levels decreased. In the skin-draining lymph node (LN) a predominant type-2 profile was seen in stimulated cells, while in contrast a type-1 profile was detected in the lung draining LN, and these responses occurred consecutively, reflecting the timing of parasite migration. The intense type-2 immune response at the site of cercarial penetration is significantly different to that seen in naive and permissive animal models such as mice, and suggests a possible mechanism for immunity. Preliminary data also suggest a reduced and delayed immune response occurred in buffaloes given high cercarial challenge doses compared with moderate infections, particularly in the skin. This study offers a deeper understanding into the immunobiology of schistosomiasis in a natural host, which may aid in the future design of more effective vaccines.

[Influence factors of Schistosoma japonicum infection among fishermen in eastern Dongting Lake Region].

OBJECTIVE: To investigate schistosome infection among the professional fishermen in Yueyang County, East Dongting Lake Region and its influence factors. METHODS: A total of 275 fishermen from two fisherman villages in Yueyang County were selected in 2009. They were investigated by fecal examination and questionnairing. The stool-egg positive individuals were detected by B ultrasound. The multivariate unconditional Logistic regression analysis was used to explore the related factors of schistosome infection and liver in fishermen. RESULTS: The total infection rate in fishermen was 40.4% (111/275), and the geometric mean of EPG was 17.4 +/- 4.4. B ultrasound data showed among 111 egg positive individuals, 39 (35.1%) cases manifested as hepatomegaly, 22 (19.8%) had splenomegaly, 11 (9.9%) had portal vein expansion and 65 (58.6%) had hepatic fibrosis. Multivariate unconditional Logistic regression analysis showed that age groups (OR = 0.630), fishing working years (OR = 2.470), chemotherapy frequency (OR = 0.425) and chemotherapy in 2008 (OR = 0.290) were the influence factors on schistosome infection (P < 0.01). CONCLUSION: Schistosome infection rate is high, Schistosoma japonicum-induced liver and spleen injuries are still severe in fisherman of Eastern Dongting Lake Region.

[Protective effect of SjC23-Hsp70 DNA vaccine and interleukin-12 on Schistosoma japonicum infection in water buffalos].

OBJECTIVE: To determine the immune-protective effect of Japan Schistosoma (Chinese mainland strain) 23 kD membrane protein-heat shock protein (SjC23-Hsp70) DNA vaccine plus adjuvantinduced interleukin-12 (IL-12) plasmid DNA on Schistosoma japonicum infection in water buffalos. METHODS: Forty-five health water buffalos (8-10 months old) in non-endemic area of schistosomiasis were randomly assigned into group A (SjC23-Hsp70+IL-12, 300 µg), group B (SjC23+IL-12, 300 µg) and group C (pVAX+IL-12, 300 µg), 15 in each group. Each buffalo was immuned by shoulder intramuscular injection for 3 times, at an interval of 28 days. Twenty-eight days after the last immunization, each buffalo was infected with 1000 Japan cercariae of Schistosoma. Fecal examinations were conducted 2 days and 1 day before the perfusion, and on the day of perfusion. The number of hatching miracidia and eggs per gram feces was recorded. Fifty-six days after the infection, the buffalos were sacrificed and perfused via the descending aorta. The recovered adult worms and eggs in the liver tissue were counted. RESULTS: We compared group A and B with group C: the estrogen reduction rate was 45.7% and 26.61%; bug reduction rate was 44.51% and 25.84%; the fecal egg reduction rate was 41.1% and 31.63%; the miracidium reduction rate was 48.11% and 38.07%; and the liver egg reduction rate was 43.39% and 31.95%. The above rates in group A were higher than those in group B (P<0.05). CONCLUSION: SjC23-Hsp70 DNA vaccine combined with IL-12 may have a significant immunoprotective effect on buffalos.

[Infectivity difference between mice challenged by the laboratory-cultivated and field collected Schistosoma japonicum-infected Oncomelania hupensis].

OBJECTIVE: To explore the infectivity difference between the mice challenged by laboratory-cultivated and field collected Schistosomajaponicum-infected Oncomelania hupensis snails. METHODS: A total of 120 Kunming mice were randomly divided into two groups. S. japonicum-infected O. hupensis releasing cercariae was according to routine cercaria shedding method. Each mouse was challenged by 40 cercariae. The worm-load, the development rate, EPG of liver and EPG of feces in the mice were calculated. RESULTS: The mean worm-load, adult worm development rate, EPG of liver and EPG of feces in the group of mice infected by field collected S. japonicum-infected snails were 27.43 +/- 3.78, 68.53 +/- 9.44, 19 800.97 +/- 6 752.59 and 196.37 +/- 11.56, respectively, which were significantly higher than those in the group challenged by cercariae from laboratory-cultivated S. japonicum-infected snails (23.93 +/- 4.93, 59.83 +/- 12.32, 5 803.69 +/-1 560.49 and 107.73 +/- 10.32) (P < 0.05). The mean worm-load, adult worm development rate and EPG of liver in the male mouse group were higher than those in the female mouse group (P < 0.05). CONCLUSION: The cercariae released from field collected S. japonicum-infected snails have more aggressive infection ability, compared with the cercariae released from the laboratory-cultivated S. japonicum-infected snails and the results also show male mice are more susceptibility to the schistosome infection than female mice.