Effects of nitroquine on the development of Plasmodium yoelii at different stages in Anopheles stephensi / 中国血吸虫病防治杂志

Objective To investigate the effects of nitroquine on the development of different stages of Plasmodium yoelii in Anopheles stephensi. Methods An. stephensi mosquitoes were fed with conventional sucrose water or sucrose water containing 100 μmol/L nitroquine one day prior to P. yoelii infection. Following starvation for 24 hours, mosquitoes were fed with the blood of Kunming mice infected with P. yoelii, and the number of oocysts was observed in the stomach of An. stephensi. After 6 days and 14 days of infection, the mosquitoes were starved for 24 hours, and then fed with conventional sucrose water or nitroquine treated sucrose water. The An. stephensi mosquitoes were starved for 24 hours 6 and 14 days post-infection with P. yoelii, and then fed with conventional sucrose water or nitroquine-containing sucrose water, the numbers of P. yoelii sporozoites were examined in the hemolymph and salivary glands of An. stephensi. Results Following exposure to nitroquine-containing sucrose water one day prior to P. yoelii infections, the number of P. yoelii oocysts was significantly lower in the An. stephensi stomach on day 7 (119.2 ± 16.1 vs. 207.3 ± 21.8; t = 3.207, P < 0.05). After conventional sucrose water was ceased for 24 hours on day 6, and An. stephensi was fed with nitroquine-containing sucrose water, the number of P. yoelii sporozoites peaked in the hemolymph on day 14 in the nitroquine treatment group (952.3 ± 22.7) and on day 12 in the sucrose water treatment group (1 287.0 ± 39.0), and there was a significant difference in the number of sporozoites in the salivary glands between the nitroquine treatment group and the sucrose water treatment group (9 467.0 ± 1 304.0 vs. 10 533.0 ± 758.7; t = 0.707, P = 0.506) on day 17. After conventional sucrose water was ceased for 24 hours on day 14, and An. stephensi was fed with nitroquine-containing sucrose water, the number of sporozoites in the salivary glands was significantly greater in the nitroquine treatment group than in the sucrose water treatment group (21 900.0 ± 2 613.0 vs. 10 533.0 ± 732.3; t = 4.188, P < 0.05). Conclusions Nitroquine treatment exhibits diverse effects the development of different stages of P. yoelii, and nitroquine treatment may reduce the transmission of P. yoelii in uninfected An. stephensi.

Anti-tumor effect of Plasmodium yoelii infection on melanoma in mice / 中国血吸虫病防治杂志

Objective To explore the anti-tumor effect of 17XL strains of Plasmodium yoelii(P.y)infection on melanoma in mice. Methods B16F10 tumor cells were axillarilly injected into the right flank of 20 C57BL/6 mice to establish tumor-bearing mouse models. The next day,the mice were randomly divided into a P.y infection group and control group,10 mice each group. Each mouse of the P.y infection group was intraperitoneally injected with 1×106 red blood cells including 20% P.y infection red blood cells,and each one of the control group were intraperitoneally injected with 1×106 normal red blood cells of C57BL/6 mice. The time of tumor formation of the mice in the two groups was observed and the tumor volumes were measured. Results The time of tumor formation in the P.y infection group[(11.30 ± 0.21)d]was significantly later than that in the control group [(10.40 ± 0.22)d](P < 0.05). From the tumors could be accurately measured to the study end point,both the tumors of mice in the two groups were growing,and the tumor volumes of mice in the P.y infection group were significantly less than those in the control group at each time point(all P < 0.05). The growth rate of tumors in the P.y infection group[(71.10 ± 6.29)mm3/d]was significantly slower than that in the control group[(302.80 ± 49.94)mm3/d](P < 0.05),and the growth rates of tumors every day in the P.y infection group were significantly slower than those in the control group(all P < 0.05). Conclusion The P.y in-fection can delay the occurrence of tumor and inhibit the growth of melanoma.

Isolation and Characterization of Vaccine Candidate Genes Including CSP and MSP1 in Plasmodium yoelii

Malaria is an infectious disease affecting humans, which is transmitted by the bite of Anopheles mosquitoes harboring sporozoites of parasitic protozoans belonging to the genus Plasmodium. Despite past achievements to control the protozoan disease, malaria still remains a significant health threat up to now. In this study, we cloned and characterized the full-unit Plasmodium yoelii genes encoding merozoite surface protein 1 (MSP1), circumsporozoite protein (CSP), and Duffy-binding protein (DBP), each of which can be applied for investigations to obtain potent protective vaccines in the rodent malaria model, due to their specific expression patterns during the parasite life cycle. Recombinant fragments corresponding to the middle and C-terminal regions of PyMSP1 and PyCSP, respectively, displayed strong reactivity against P. yoelii-infected mice sera. Specific native antigens invoking strong humoral immune response during the primary and secondary infections of P. yoelii were also abundantly detected in experimental ICR mice. The low or negligible parasitemia observed in the secondary infected mice was likely to result from the neutralizing action of the protective antibodies. Identification of these antigenic proteins might provide the necessary information and means to characterize additional vaccine candidate antigens, selected solely on their ability to produce the protective antibodies.

Potentiation of antimalarial activity of arteether in combination with Vetiver root extract.

In malaria, development of resistance towards artemisinin derivatives has urged the need for new drugs or new drug combinations to tackle the drug resistant malaria. We studied the fresh root extract of Vetiver zizanioides (Linn.) Nash (VET) with a CDRI-CIMAP antimalarial α/β arteether (ART) together for their antimalarial potential. Our results showed additive to synergistic antimalarial activity of VET and ART with sum fractional inhibitory concentrations Σ FICs 1.02±0.24 and 1.12±0.32 for chloroquine sensitive (CQS) and chloroquine resistant (CQR) strain of Plasmodium falciparum (William H. Welch), respectively. Further, these combinations were explored against multidrug resistant rodent malaria parasite i.e. P. yoelii nigeriensis. Analysis of in vivo interaction of ART and VET showed that 10 mg/kg×5days of ART with 1000 mg/kg of VET ×5 days cured 100% mice infected with MDR parasite, while the same dose of ART could produce only up to 30% cure and VET fraction was not curative at all. Synergism/additiveness, found between VET and ART is reported for the first time. The curative dose of ART in the combination was reduced to its one fourth, and thus limits the side effects, if any. Although antimalarial potential of ART was enhanced by VET, action mechanism of later needs to be elucidated in detail.

Antioxidant and antiplasmodial activities of curcuma longa and aegle marmelos on malaria infeced mice (in vitro and in vivo).

The purpose of this study is to evaluate the antioxidant activity of Thai Curcuma longa and Aegle marmelos, and their parasite suppressive effects on malaria infection in mouse model. The polyphenol content and antioxidant activities (Oxygen radical absorbance capacity (ORAC) and Ferric Reducing Antioxidant Power (FRAP)) were measured in crude extracts of Curcuma longa and Aegle marmelos. Seven-week old female ICR mice were divided into 5 groups randomly. First two groups served as control and placebo, the other 3 served as experimental groups with various concentrations; 20, 40 and 60 mg/kg, respectively. On day 0, 106 Plasmodium yoelii 17X (lethal) strain were inoculated to all mice. At day 1, placebo mice were given 30% ethanol. The latter 3 groups were treated with each concentration of each herb. Parasitemia was checked daily by tail snip bleed staining with Giemsa staining. Suppressive effects on day 4 were calculated. Student t-test was performed to display the difference among groups. Significantly different was justified at p <0.05. The antioxidant activities (both ORAC and FRAP) and polyphenol content of A. marmelos were higher than those of C. longa significantly. The suppressive effect on parasite in infected mice, there showed no effect of C. longa treatment, oppositely, at the doses of 20 and 40 mg/ kg body weigh of A. marmelos showed suppressive effect on infection by the parasite. In conclusion, a Thai traditional fruit, A. marmelos exhibited high antioxidant and antiplasmodial activities, this might be one of the candidates of the traditional plants for curing malaria.

A single injection of 19 kDa carboxy-terminal fragment of Plasmodium yoelii merozoite surface protein 1 (PyMSP119) formulated with Montanide ISA and CpG ODN induces protective immune response in mice.

Objective: To investigate the efficacy of a vaccine formulation of the 19 kDa conserved carboxyl-terminal fragment of Plasmodium yoelii merozoite surface protein-1 (PyMSP119) formulated with CpG ODN 1826 and Montanide ISA51 or ISA720 when used to immunize mice by a single injection. Methods: Groups of BALB/c mice were immunized parenterally with one, two or four injections with PBS or PyMSP119 formulated with CpG ODN in ISA51 or ISA720. Sera were collected weekly and assessed for total IgG and IgG subclass titers. Protection was tested by challenge infection with P. yoelii YM. Results: Interestingly, single injection immunization showed the same kinetics of antibody responses as two- or four-injection immunization. However, the peak antibody response induced by PyMSP119 in CpG ODN and ISA51 appeared earlier than that induced by PyMSP119 in CpG ODN and ISA720 (28 days vs 41 days). At day 63 after the first injection, the PyMSP119-specific IgG antibody levels by single injection and four- injection immunizations were not different. However, the levels of the IgG2a antibody subclass were significantly lower by single injection immunization with PyMSP119 in CpG ODN and ISA720. The antibodies were sustained at high levels for at least 20 weeks. After challenge infection, all mice immunized by a single injection of PyMSP119 in CpG ODN and ISA51 survived with low-grade parasitemia, while 50% of mice immunized with PyMSP119 in CpG ODN and ISA720 died with high levels of parasitemia. Conclusion: These findings suggest that MSP119 immunization by a single injection can induce protective immunity, particularly when formulated with an appropriate strong adjuvant.

Role of Toll-like receptor in the dendritic cell response during early Plasmodium yoelii infection / 中国人兽共患病学报

To investigate the role of Toll like receptor (TLR) in the activation of dendritic cells (DC) during early Plasmodium yoelii infection of the lethal strain 17XL (P.y 17XL), susceptible BALB/c and resistant DBA/2 mice were infected by i.p.injection of the P.y l7XL-parasitized erythrocytes, and the parasitemia of individua1 mice was monitored by the microscopic examination of blood smear stained with Giemsa.Mice from norma1 and infected groups were sacrificed on 0,3 and 5 days post-infection to collect their spleen cells.And the expressions of TLR-9 and TLR-4 on the cell surface of DCs in spenonocytes of these two strains of mice were assayed by applying flow cytometry to quantitatively analyze the percentages of CD11c+TLR9+ DCs and CD11c+TLR4+ DCs. It was found that the population of CD11c+DCs expressing TLR9 was significantly increased on day 3 and peaked on 5 p.i. in BALB/c (P<0.01) and DBA/2 mice(P<0.01). However, there was no statistical significance between these two strains of mice. Meanwhile, there was no change on the population of CD11c+ DCs expressing TLR4 in BALB/c and DBA/2 mice. These results indicate that TLR9 may contribute to the DC activation during early stages of P.y17XL infection.

Study on Protective Immunity against Infection of Plasmodium yoelii 17XL in DBA/2 Mice / 中国寄生虫学与寄生虫病杂志

Objective To investigate the development and dynamic changes of host immune response in DBA/2 mice infected with Plasmodium yoelii 17XL. Methods Female DBA/2 mice were infected by intraperitoneal ( i. p. ) injection of 106 P. yoelii 17XL parasitized erythrocytes ( PRBC). Levels of IL-12, IFN-γ, IL-4, IL-10 and P. yoelii 17XL-specific antibody in sera were measured by ELISA. Concentrations of NO in cell supernatants were measured by the Griess reaction. Parasitemia,percentage of mononuclear-macrophages of individual mice were monitored daily, and phagocytosis of mononuclear macrophages was also observed. Results Primary parasitemia in vein blood was developed on day 3 postinfection, which peaked with a level of 46. 9% on day 9. Most mice cleared the infection and survived by day 20 postinfection. From day 6 to day 16, the phagocytosis of PRBC by rodent macrophages was observed on the blood smear. Infected mice had a continuously increased level of IL-12 in serum from day 1 postinfection. Accordingly, high level of IFN-γ was also detected in sera from day 1 postinfection,which peaked on day 6. Infected mice produced higher level of IL-4 and IL-10 in serum on day 6 postinfection, which peaked on day 9 and day 15 postinfection respectively. In addition, splenocytes from infected mice produced significantly higher level of NO on day 6 and 20 postinfection. Level of P. yoelii 17XL-specific IgG was determined in the sera of infected mice with a steadily increased trend after infection, which peaked on day 70 postinfection. Conclusions Effective polarizing of Thl cells is significant in inhibition of parasitemia and eventual clearance of the Plasmodium parasites. Activated mononuclear-macrophages play a key role in inhibiting parasitemia in the early phase of infection with P. yoelii 17XL.

Effect of blood-feeding and plasmodium yoelii infection on the transcript abundance of ribosomal protein S7 from Anopheles dirus hemocyte / 第三军医大学学报

Objective To observe the effect of blood feeding and plasmodium yoelii infection on the transcript abundance of ribosomal protein S7 from Anopheles dirus hemocyte Methods Anopheles dirus of 3～5 days old were divided into normal group (N), blood feeding group(B) and Plasmodium yoelii infection group(I) Hemocytes of 50 Anopheles dirus from each group were collected by centrifuge method on days 1, 2, 3, 4, 7 and 11 after blood feeding, respectively Then, all hemocyte samples were used for total RNA isolation and analyzed by RT PCR Finally, the same volume(10 ?l) of all the PCR products from each group was used for agarose gel electrophoresis and the data obtained were analyzed statistically Results There was no significant difference in ribosomal protein S7 signal between the three groups Conclusion Similar to Anopheles gambiae and human rpS7, Anopheles dirus rpS7 might be also used as an internal control for the studies of the role of Anopheles dirus related immune factors in attacking Plasmodium infection

SDS-PAGE analysis of differentially expressed proteins from Anopheles stephensi hemolymph produced during the Plasmodium yoelii oocysts melanization / 第三军医大学学报

Objective To explore primarily the differentially expressed proteins in the hemolymph from adult female Anopheles stephensi ( An stephensi ) infected with Plasmodium yoelii ( P yoelii ) after being fed with sucrose solution containing nitroquine or not at different time points Methods Hemolymph of 2 groups of adult female An stephensi was collected with the expulsion method from the first day to the fifth day after the feeding Hemolymph samples were examined with SDS PAGE The protein gels were visualized by either Coomassie brilliant blue or silver staining, scanned and automatically analyzed by the BioRad1000 gel image analysis system for differential proteins bands Results On the second day of feeding with nitroquine, a few oocysts were partially melanized Furthermore, during the period from the fifth day to the ninth day, the number of mosquitoes with malanized oocysts and the number of melanized oocysts gradually increased The number of hemolymph protein binds in the treatment group was markedly more than that in the control Many different bands, mainly located at the molecular weight of (20～40)?10 3 and (60～80)?10 3, were visualized in the 2 groups The number of protein bands stained by the silver staining was more than that by the Coomassie brilliant blue staining Conclusion There are differentially expressed proteins in the hemolymph in An stephensi infected with P yoelii after being fed with sucrose solution containing nitroquine These differential proteins may be the melanization engaging proteins

Expressions of B7.1 and B7.2 in macrophagus of rats infected by Plasmodium yoelii / 第三军医大学学报

Objective To study the expression levels of B7.1 and B7.2 in the macrophagus of rats infected with the Plasmodium yoelii sporozoites and investigate the roles of these costimulators in parasite infection immunity. Methods The mammal model was established by infecting rats with the sporozoites, then macrophagus was separated from the rat abdominal cavity 2, 12, 24, 48, 72 h after infection. The expressions were quantitative analyzed by immunofluorescence staining and laser scanning confocal microscopy. Result The expressions of B7.1 and B7.2 were upregulated after infected with the sporozoites. The expression of B7.1 was slowly induced and then descended at 72 h. B7.2 was rapidly induced and maximally expressed at 48 h and downregulation at 72 h. The expression of B7.2 was significantly higher than that of B7.1 at all time points assayed after stimulation (P

Gene expression of circumsporozoite protein and erythrocyte binding protein of Plasmodium yoelii in the sporozoites from oocyst and salivary gland at different phases / 第三军医大学学报

Objective To study the gene expression change of circumsporozoite protein (CSP) and erythrocyte binding protein (MAEBL) in the Plasmodium yoelii sporozoites from oocyst and salivary gland at different phases during Plasmodium yoelii development in mosquitos. Methods The total RNA of plasmodium was extracted from the abdomen on day 5, 7, 10 and the thoraces on day 12, 15, 18 after Anopheles stephensi was infected by Plasmodium yoelii, then the expression of CSP and MAEBL mRNA was analyzed by semiquantitative RT-PCR with rRNA 28S as control. Results The transcription of CSP and MAEBL of plasmodium sporozoite were obviously up-regulated during the mosquito stage (P

The study of the effective mechanism of infected host serum on the infectivity of gametocytes of Plasmodium yoelii (P.yoelii) / 中国免疫学杂志

Objective:To clarify the mechanism of crisis serum' mediated gametocyte infectivity to the mosquito vector Methods:Observing the effects of mouse serum , which was obtained 5 days after P yoelii infection (D5 serum) on gametocyte infectivity by IFA and mosquito live feeds, and the production of IFN ??TNF ??IL 4 and NO - 2 in the hosts in vivo and in vitro by ELISA and Griess reaction And to investigate the ability of malaria parasitized red blood cell extract (PRBC extract) to induce NO Results:The development of the gametocytes from mice 5 days postinfection into ookinetes were completely inhibited D5 serum was not immediate to inhibit gametocyte development, which was injected intravenously into the mice 3 days after P yoelii infection But 4 h later after injection D5 serum stimulated the increasing IFN ? and NO production and inhibited gametocyte infectivity Moreover, PRBC extract showed the ability to induce NO Conclusion:Infected host serum blocks transmission of P yoelii via a nitric oxide dependent mechanism

Enrichment and Screening of Up-regulated Genes of the Mosquito Anopheles stephensi in Response to Malaria Parasite / 中国寄生虫学与寄生虫病杂志

Objective To isolate and identify genes related to malaria parasite infection in vector mosquito, and to explore the mechanisms. Methods Anopheles stephensi infected with Plasmodium yoelii was used as tester (T) group, while uninfected but normal blood fed as driver (D) one. Engorged female mosquitoes of two groups were collected separately at 24 hours after biting. An enriched subtractive cDNA pool was generated through the course of suppression subtractive hybridization (SSH) and selective PCR amplification. The subtracted library was screened by hybridization using T and D cDNA mixture as probes, respectively. The positive clones, which produced stronger signal when probed with T than with D, were sequenced and their sequence homologues in GenBank database were searched with BLAST by internet. Results The analysis of subtraction efficiency showed that the differentially expressed genes in T comparing to in D were enriched significantly. In dot blot screening, 24 of 58 randomly selected clones (41.4%) were shown up regulation in malaria infected mosquitoes. The BLAST search of 23 genes revealed that 12 were homologous to functionally known genes, 4 were homologous to functionally unknown entries, and 7 were novel without any relatives. Nine of the 23 genes (39.1%) also hit homologous sequences in the An. gambiae EST database generated from an immune competent cell line treated with lipopolysaccharide (LPS). Conclusion An enriched cDNA pool of the mosquito genes which up regulated responsively at the early stage of malaria parasite infection was obtained. Expression screening against the pool indicated that various biochemical processes and mechanisms might be involved in the response of mosquito to parasite infection, especially those related with the innate immune system and energy metabolism.

The Internal Control Role of Ribosomal Protein S7 in the Defense of Anopheles dirus Against Plasmodium Infection / 中国寄生虫学与寄生虫病杂志

Objective To investigate the role of ribosomal protein S7(rpS7) in the defense of Anopheles dirus against infection. Methods rpS7 was amplified from Anopheles dirus hemocytes with degenerated primers designed according to the conservative region of S7, rpS7 was then cloned using T/A cloning kit and the inserted fragment was sequenced. The difference of the transcript abundance of rpS7 from Anopheles dirus hemocyte among non-blood-fed (N), normal-blood-fed (B) and Plasmodium yoelii infected groups (I) was also analyzed by RT-PCR and gel scanning system at d1, d2, d3, d4, d7 and d11 after blood feeding. Results There is no significant difference of rpS7 signal between the three groups. Conclusion Anopheles dirus S7 can be used as an internal control to study the role of Anopheles dirus related immune factors in Plasmodium infection.

Effect of Anti-Midgut-Protein-Ingredient Antibodies of Anopheles stephensi on the Oocysts of Plasmodium yoelii / 中国寄生虫学与寄生虫病杂志

Objective To observe the inhibitory effect of the antibodies against midgut-protein-ingredient of Anopheles stephensi on the oocysts of Plasmodium yoelii.Methods Female An.stephensi mosquitoes raised in laboratory were dissected and the midguts were collected.Eight BALB/c mice were immunized using midgut-protein(100 ?g/mouse,4 times with an interval of 7～10day).Ten days after the last immunization,blood was taken from mice armpit artery and serum separated.The immune active antigen of the midgut protein was analyzed by Western blotting.Protein with Mr 38 000～50 000 was separated by sephadex filtering and used to immunize 12 BALB/c mice(100 ?g/mouse,4 times with interval of 7～10 days).PBS control group was established.Seven days after the last immunization,serum antibody was detected by ELISA.When the antibody titer in immunized mice reached ≥1:2 560,mice in both groups were infected by P.yoelii(about 2?107 plasmodium-infected RBC) by abdominal injection.The mosquitoes were fed on the infected mice when the number of female gametes was higher than 2 per 10 microscopical fields 3 days later.After 9 days,the mosquitoes were dissected and the amount of oocysts in midgut was counted.Results Eight protein bands were shown in midgut-protein of An.stephensi by Western blotting and the band of Mr 38 000～50 000-midgut-protein appeared clearer.The infection rate of oocysts in the experiment and control groups were 28.70%(62/216) and 51.09%(47/92) respectively(P

Enhanced transcript abundance of AdsP1 and AdsP3 from Anopheles dirus haemocytes after Plasmodium yoelii infection / 第三军医大学学报

Objective To investigate the expression patterns of serine proteases Adsp1 and Adsp3 in the main tissue of Anopheles dirus and the effects of blood feeding and Plasmodium infection on the transcript abundance of Adsp1 and Adsp3 from Anopheles dirus haemocytes. Methods Haemocytes were collected by centrifugation. The midguts and salivary glands were dissected from 50 adult female Anopheles dirus of 3-5 d old for the extraction of total RNA for amplification by RT PCR. Anopheles dirus of 3-5 d old were divided into normal group (N), blood feeding group (B), and Plasmodium yoelii infection group (I). Haemocytes of 50 adult female Anopheles dirus from each group after blood feeding were also collected, and the total RNA was isolated at 1, 2, 3, 4, 7, and 11 d, respectively. Then, the same volume (10 ?l) of total RNA was analyzed by semi quantitative RT PCR with Ads7 as the internal control. Agarose gel analysis was performed on PCR products from each group. Results Expression of both Adsp1 and Adsp3 mRNA was found in the haemocytes and salivary glands, but not in the midguts. Semi quantitative RT PCR indicated that transcript abundance of AdsP1 and AdsP3 from Anopheles dirus haemocytes was enhanced after blood feeding and Plasmodium yoelii infection, especially during melanotic encapsulation of Plasmodium yoelii . Conclusion AdsP1 and AdsP3 may be involved in the melanotic encapsulation response of Plasmodium yoelii by Anopheles dirus , and may be the prophenoloxidase activating enzyme of Anopheles dirus .

Changes of prophenoloxidase in the midguts of Anopheles stephensi and Anopheles dirus before and after infection with Plasmodium yoelii / 第三军医大学学报

Objective To investigate the relationship between the immune defence reaction against Plasmodium infection and the prophenoloxidase (PPO) of the midgut by comparative analysis of the distributions and the changes of PPO in the midgut of Anopheles stephensi and Anopheles dirus before and after infection with Plasmodium yoelii . Methods Midguts were dissected out from both Anopheles stephensi and Anopheles dirus at 3, 5, 7, 11 and 15 d before and after infection with Plasmodium yoelii . Immunohistochemistry and Western blotting were performed respectively on the collected midguts using Manduca Sexta PPO IgG polyantibody. Results PPO in the midguts from both Anopheles stephensi and Anopheles dirus was mainly located in the circulation conduit of midgut before infection with Plasmodium yoelii , but aggregated and distributed at the interspace of midguts as pieced or/and stripped forms after infection. Furthermore, PPO in the midgut of Anopheles dirus was more concentrated than that of Anopheles stephensi . Western blotting revealed that the PPO band with about molecular weight of 67?10 3 was detected in the midguts of both Anopheles stephensi and Anopheles dirus before and after Plasmodium yoelii infection. There was significant difference before and after infection, and the PPO band was obviously enhanced after infection. PPO bands in the midgut of Anopheles dirus were more prominent than those of Anopheles stephensi . Conclusion PPO in the midgut of Anopheles mosquitoes may come from the hemolymph by the circulation conduit before Plasmodium yoelii infection. However, the different distributions and changes of PPO in the midguts resulted from the Anopheles mosquitoes infected with Plasmodia may be closely correlated with Plasmodia infection, which may be of important physiological significance and may be involved in the immune defensive reaction against Plasmodium .

The effects of nitroquine on the ultrastructures of nitraery-throcytic stage of Plasmodium yoelii in mice / 第三军医大学学报

After a single oral dosed mg/kg) of nitroquine to the mice infected with Plasmodium yoelii,the morphological changes of the parasites were studied with optical and electron microscopy.Enlarged nucleus and some red granules scattered over the cytoplasm in the late trophozoites were observed under optical microscope,which may correspond to the autophagocytic vacuo-les or membranous residual bodies seen under electron microscope.Thirty minutes after the drug administration,the number of mitochondria with matrix cavitation was increased,the endoplasmic reticulum dilated,and ribosomes separated,detached,or disaggregated.Then the pelliculous complex and nuclear membrane of the parasites proliferated to form multi-layered structure with spiral curv?s or myelin sheath-like structure in the cytoplasm.The nuclear membrane was swollen and proliferated and the perinuclear cisterna was widened.In the late stage of drug action,the structure of the parasites was broken down to form a large number of autophagocytes.The findings indicate that nitroquine interferes with the structure and function of the cell membrane,cytoplasm and nucleus of malaria parasites and exerts its anti-malarial effects from many aspects.

Inhibition of CpG Oligodeoxynucleotide on the Development of Pre-erythrocytic Stage of Plasmodium / 中国寄生虫学与寄生虫病杂志

Objective To study the role of cytidine-phosphate-guanosine oligodeoxynucleotide(CpG ODN) on the development of Plasmodium liver stage.Methods Plasmodium yoelii BY265 18S rRNA was cloned,and the TaqMan real-time PCR was established on P.yoelii BY265 18S rRNA and mouse GAPDH as quantitative analysis model.The model was tested by the level of liver Plasmodium load with the liver cDNA in BALB/c mice infected by salivary gland sporozoites for 42 hours.Twelve BALB/c mice were randomly divided into CpG group,CpG control group and PBS control group which were injected respectively by ODN1826 30 ?g,ODN1826 control 30 ?g and 0.01 mol/L PBS 200 ?l via vena caudalis.Twenty-four hours later,each mouse was inoculated with 100 sporozoites.Mice were sacrificed in 42 hours after infection,and the liver load of Plasmodium was analyzed by TaqMan real-time PCR.Results The cloned Py BY265 18S rRNA gene showed 98% similarity to Py 17XNL.The quantitative analysis model consisted by 18S rRNA and GAPDH showed positive correlation between the level of liver Plasmodium load and the sporozoite inoculation dose to mice.The Plasmodium load in CpG ODN pre-treated mice was reduced to one fifth of the control group(0.28/1.33)(P