Induction of matrix metalloproteinase-9 in mice during Toxocara canis larvae migration

The relationships between inflammation in organs with Toxocara canis larval migration and matrix metalloproteinase-9 (MMP-9) were investigated following the infection of mice with 1,000 infective eggs. Gelatinase activity was defined by gelatin zymography, optimum pH, inhibitor specificity and Western blot analysis. MMP-9 activity was present in the lungs, liver, muscles, and brain during T. canis larval migration. This enzyme had a molecular weight of about 94 kDa and showed maximum activity in the pH range of 6–8. The increased MMP-9 proteinases coincided with larval recovery and the degree of inflammation among the four organs. These results suggest that MMP-9 may be associated with the inflammatory reaction to larval toxocariasis during early migration, and may therefore be a useful marker during T. canis larvae migration.     

Effectiveness of mefloquine against Clonorchis sinensis in rats and Paragonimus westermani in dogs

The aim of the study is to explore the effect of mefloquine against Clonorchis sinensis and Paragonimus westermani. For anti-C. sinensis study, a total of 71 rats were divided into four batches for oral infection of each rat with 50 C. sinensis metacercariae. Five to 7 weeks post-infection, groups of rats were treated orally with mefloquine at single doses or multiple daily doses while infected, but untreated rats served as control. All treated rats were euthanized 2 weeks post-treatment for assessment of efficacy. For anti-P. westermani study, two batches of eight and ten dogs were each infected intraperitoneally with 100 P. westermani metacercariae. Eighty-five to 96 days post-infection, groups of two or three dogs were treated orally with mefloquine and groups of two dogs were treated with praziquantel at a single dose or multiple doses. In each batch of test, three untreated but infected dogs served as control. All treated dogs were euthanized 26–30 days post-treatment for evaluation of efficacy. In rats infected with C. sinensis and treated orally with mefloquine at a single dose of 75 and 150 mg/kg, no effect against C. sinensis was observed. When the dose of mefloquine was increased to 250 mg/kg, one third (five out of 15) rats died 3–5 days post-treatment. Although the mean worm burden was lower than that of the control, the difference between the treated and control groups was not statistically significant (P > 0.05) with worm burden reduction of 22.4%. Whereas, the group of infected rats received mefloquine at a daily dose of 100 mg/kg for 3 days, one out of five rats died after the last administration. The mean worm burden was significantly lower than that of the control with worm burden reduction of 67.6% (P < 0.01). In the first test of mefloquine against P. westermani, three infected dogs received two oral doses of the drug, 50 mg/kg, given at a 4-h interval, the mean worm burden were similar to that of the control. While other two dogs were treated with praziquantel at the same dose schedule, the worm burden reduction of 78% was observed. In the second test, three and two dogs were treated with mefloquine 50 mg/kg daily for 5 days or 100 mg/kg daily for 2 days; the mean worm burdens of the two groups were lower than that of the control with worm burden reduction of 65.6% and 51.9%, respectively. However, only the difference of mean worm burdens between mefloquine 50 mg/kg given daily for 5 days and the control was statistically significant (P < 0.05). Other two dogs treated with praziquantel at a single dose of 100 mg/kg were cured. The results indicate that under the appropriate dose schedule mefloquine exhibits less effect against C. sinensis in rats and P. westermani in dogs.     

The effect of tribendimidine and its metabolites against Necator americanus in golden hamsters and Nippostrongylus braziliensis in rats

The antinematode effect of tribendimidine (TBD) and its metabolites has been studied. A total of 107 hamsters were each infected with 250 Necator americanus third stage infective larvae (NaL3) for 25 days. In the first test, 75 hamsters were divided equally into 15 groups for determination of ED₅₀ and ED_90. Among them, five groups were treated orally with TBD or its metabolite, p-(1-dimethylamino ethylimino)aniline (aminoamidine, deacylated amidantel, BAY d 9216, dADT), at single doses of 1, 2, 4, 8, and 16 mg/kg. The remaining five groups were administered with acetylated dADT (AdADT) at single oral doses of 8, 12, 18, 24, and 30 mg/kg. In the second test, 20 hamsters were equally divided into four groups. Two groups were treated intramuscularly with TBD and dADT at a single dose of 16 mg/kg, while in the remaining two groups, single intramuscular dose of AdADT 15 or 30 mg/kg was administered. In the third test, two groups of six hamsters were treated orally with terephthalaldehyde (TPAL) and terephthalic acid (TPAC) at a single dose of 1,000 mg/kg. Other 85 rats, each infected with 300 Nippostrongylus braziliensis third stage infective larvae (NbL3), were used in three tests. For determination of ED₅₀ and ED₉₀ in the first test, five groups of five rats were treated orally with TBD or dADT at single doses of 3.0, 4.2, 5.9, 8.2, and 11.5 mg/kg or 2.0, 2.9, 4.2, 6.1, and 8.8 mg/kg, respectively. In the second test, three groups of eight to nine rats were treated orally with TBD at a single 8.4-mg/kg dose (ED₉₀) and AdADT 100 or 200 mg/kg, respectively. In the third test, two groups of four rats were treated orally with TPAL and TPAC at a single dose of 1,000 mg/kg. Twenty-four to 48 h post-treatment, all the feces of each hamster and rat were collected for recovery of worms expelled from the feces. Following this period, all of the animals were sacrificed, and the adult hookworm or N. braziliensis from small intestine and large intestine were recovered and counted for calculation of worm burden reduction. The results showed that the ED₅₀ and ED₉₀ for TBD, dADT, and AdADT determined in treatment of N. americanus-infected hamsters were 1.849 and 13.598, 3.922 and 54.354, as well as 20.966 and 51.633 mg/kg, respectively. In intramuscular administration of TBD and dADT at single dose of 16 mg/kg or AdADT 30 mg/kg, similar worm burden reductions of 71.4–76.3% were observed. Two other metabolites, i.e., TPAL and TPAC, exhibited no effect against N. americanus. The ED₅₀ and ED₉₀ for TBD and dADT determined in treatment of rats infected with N. braziliensis were 3.234 and 8.435, as well as 2.345 and 5.104 mg/kg. Oral administration of AdADT at a higher single dose of 100 or 200 mg/kg resulted in worm burden reductions of 11.9–46.3%, which was significantly lower than 84.5% of worm burden reduction obtained from rats treated with TBD 8.4 mg/kg. The results indicate that in oral administration, TBD exhibits slightly better effect against N. americanus in hamsters than dADT, but AdADT possesses less effect; TBD, dADT, and AdADT show promising effect in intramuscular treatment of N. americanus-infected hamsters; the effect of oral dADT against N. braziliensis in rats is somewhat better than TBD, while AdADT endorses poor effect; and TPAL and TPAC are ineffective metabolites of TBD against both species of nematodes.     

Effect of mefloquine administered orally at single, multiple, or combined with artemether, artesunate, or praziquantel in treatment of mice infected with Schistosoma japonicum

The purpose of the study is to better understand the antischistosomal properties of artemether, praziquantel, and ozonide (OZ) compounds (synthetic trioxolanes, secondary ozonides) in hamster (Mesocricetus auratus) model. A total of 230 male hamsters infected each with 100 Schistosoma japonicum cercariae were used in the study. Groups of five to ten hamsters were treated orally with artemether, praziquantel, and OZ78 or OZ277 7–35 days post-infection at single doses of 50, 100, 150, or 200 mg/kg. Untreated but infected hamsters in each batch of test served as the control. All treated hamsters were sacrificed 4 weeks post-treatment for collection of residual worms using perfusion technique. Nonparametric method (Mann–Whitney test) was used to analyze the data. In groups of five hamsters treated with artemether 7, 14, 21, 28, and 35 days post-infection at single doses of 150 and 200 mg/kg, the difference of mean worm burden between each treated group and control group was statistically significant (P < 0.01). Apart from individual group, no difference in mean worm burden between each two groups of them was seen (P > 0.05). Further test with various single doses of 50–200 mg/kg confirmed the similar susceptibility of 7-day-old juvenile and 35-day-old adult schistosomes to artemether. After administration of praziquantel 100 mg/kg to groups of five hamsters 7, 21, and 35 days post-infection, higher worm burden reduction of 95.5% was seen in the group with 35-day-old adult schistosomes while in the groups with 7- and 21-day-old juvenile schistosomes, poor efficacy was seen with mean worm burden reductions of 36.6% and 35.6%. In the same batch of hamster treated with praziquantel 200 mg/kg, the moderate effect of the drug against 7- and 21-day-old worms was seen, but their mean worm burden was significantly higher than that of the group with adult schistosomes. In comparison of artemether and praziquantel against various stages of schistosomes, the results further demonstrated that artemether possessed similar effect against juvenile and adult schistosomes in hamsters, while praziquantel was more effective against adult schistosomes than the juvenile ones in the same host. Finally, after administration of OZ78 and OZ277 to the groups of four to six hamsters with 14- and 35-day-old schistosomes at a single dose of 200 mg/kg, promising effect against juvenile and adult schistosome was observed with the mean worm burden and female worm burden reductions of 69.6–94.2% and 64.2–100% as well as 73.3–80.7% and 68.3–81.1%, respectively. The results indicate that in hamster model, praziquantel exhibits higher effect against adult schistosomes than the juvenile ones, while artemether and OZ compound display similar effect against both juvenile and adult schistosomes.     

不同剂量环磷酰胺诱导正常小鼠免疫抑制的对比研究

目的观察不同剂量环磷酰胺对正常小鼠免疫抑制的影响。方法采取不同的时间给予正常小鼠腹腔内注射小同剂量的环磷酰胺(CY),观察对小鼠免疫学指标的影响。结果正常小鼠腹腔注射20、80、100mg/kg的CY后,各剂量组均出现不同程度的免疫抑制。结论给予正常小鼠腹腔注射20、80、100mg/kg的CY,可建立免疫抑制模型,并且连续3d腹腔注射剂量为80mg/(kg·d)1CY的效果盛明显。     

Comparable seropositivity for ascariasis and toxocariasis in tropical slum children

The seropositivities for infection byAscaris lumbricoides andToxocara canis were determined in children (1–15 years old) of a slum area of Caracas, Venezuela, and the levels that indicate the presence of active infection were defined. In children aged from 1 to 3 years, approximately 10% were positive for either parasite, and this figure increased to about 30% in 4- to 6-year-olds. For toxocariasis, the percentage of positivity remained at this level up to the age of 15 years. Whilst the positivity in children 10–15 years of age was comparable forAscaris andToxocara, a peak of positivity (50%) was found forAscaris at 7–9 years of age. These results indicate that for these urban slum children, infection byToxocara is essentially as common as that byAscaris and, thus, that toxocariasis represents a potential public health problem in the tropical environment that is largely overlooked.     

Recombinant expression of the larval excretory-secretory antigen TES-120 of<Emphasis Type="Italic"> Toxocara canis</Emphasis> in the methylotrophic yeast<Emphasis Type="Italic"> Pichia pastoris</Emphasis>

A gene encoding the larval excretory-secretory antigen TES-120 of the dog ascarid worm Toxocara canis was cloned into the methylotrophic yeast Pichia pastoris. Specificity of the recombinant TES-120 antigen produced by the yeast was investigated. Forty-five human serum samples from patients infected with differentparasitic organisms, including 8 cases of toxocariasis, were tested against the recombinant antigen in immunoblot assays. Results from the assays showed that the recombinant TES-120 antigen reacted with sera from toxocariasis patients only. This highly specific recombinant TES-120 antigen can potentially be used for the development of an inexpensive serodiagnostic assay for human toxocariasis.     

The Effect of Two Glucan Carboxymethyl Derivatives with Various Substitution Degrees on Cyclophosphamide Immunosuppression in Mice

Abstract

Carboxymethylglucan (CMG)¹ in two different degrees of substitution of carboxymethyl groups (0.56 and 0.89) was administered to cyclophoshamide (CY) treated (200 mg/kg) C57B1/6 mice in three doses (10, 50, and 100 mg/kg) 24 h after CY. The influence of CMG administration on the cell suppression caused by CY was observed in the subsequent days. The cellularity of spleen, bone marrow and peripheral blood was quantified on days 2, 5, 8, 11, 15, and 21 after CY treatment.

CY treated mice developed a significant decrease in peripheral blood cell counts, and spleen and bone marrow cellularity during the initial 5 days, followed by recovery in the next 15 days, with an overshoot reaction in spleen cellularity and erythrocyte levels.

The initial cellularity depression and the following recovery was modified by both carboxymethyl derivatives of glucan. Cyclophosphamide treated mice exhibited less pronounced immunosuppression and more rapid hematopoietic recovery when administered with CMG, althought this reaction was only of a modest degree. The effects were not dose dependent and the differences between the two glucans were not significant.     

Comparative effect of mebendazole, albendazole, tribendimidine, and praziquantel in treatment of rats infected with Clonorchis sinensis

The aim of the study is to understand the anti-Clonorchis sinensis properties of mebendazole and albendazole, and compare to praziquantel and tribendimidine. Two hundred and thirty rats were divided into five batches for experimental treatment. In four batches, each rat was infected orally with 50 or 100 C. sinensis metacercariae. Twenty-eight to 46 days post-infection, groups of rats were treated orally with single doses of mebendazole, albendazole, praziquantel, tribendimidine, or multiple daily doses of albendazole. While in the remaining batch, mebendazole or praziquantel was administered to groups of rats infected each with 50 metacercariae for 7 or 14 days. In each batch of test, untreated but infected rats served as control. All rats were euthanized 2–4 weeks post-drug administration for assessment of efficacy. In the first batch of test, rats treated with mebendazole or tribendimidine at single doses of 150, 75, and 37.5 mg/kg resulted in worm burden reductions of 99.0%, 94.0%, and 73.1%, or 98.0%, 80.6%, and 60.4%, respectively. When rats were treated with albendazole at the same dose levels, no or poor effect was seen. In the second batch of test, promising effect against adult C. sinensis in rats treated with mebendazole or tribendimidine at single doses of 100 and 50 mg/kg were also observed, but under the single dose of 25 mg/kg, only tribendimidine still remained the effect. In the third batch of test, the aforementioned three single dose levels of mebendazole, albendazole and praziquantel were applied. Again, mebendazole exhibited higher effect and albendazole exhibited no or poor effect. While praziquantel, administered at a higher dose of 300 mg/kg, also showed promising effect. In the fourth batch of test, oral administration of albendazole at a daily dose of 150 or 100 mg/kg for 2 or 3 days resulted in moderate or higher efficacy with worm burden reductions of 79.2% and 91.9%, respectively. In the fifth batch of test, single mebendazole doses of 150 or 75 mg/kg exhibited promising effect against 14-day-old C. sinensis in rats with worm burden reductions of 95.3% and 86.4%, respectively, but mebendazole was short of the effect against 7-day-old worms. Under the same dose level, praziquantel possessed an effect against both 7- and 14-day-old juvenile C. sinensis. The results confirm that in infected rats, mebendazole administered orally at a single dose of 150 mg/kg exhibits potential effect against juvenile (14-day-old) and adult C. sinensis. No or less effect is obtained from albendazole under the same dose levels, but extension of treatment course may enhance the effect of albendazole against this species of fluke. The single effective dose ranges of mebendazole and tribendimidine against C. sinensis in rats are similar with a broad window, while the window for praziquantel is narrow.     

<Emphasis Type="Italic">Toxocara canis</Emphasis> larvae reinfecting BALB/c mice exhibit accelerated speed of migration to the host CNS

Using a small animal imaging system, migratory activity of Toxocara canis larvae stained by carboxyfluorescein succinimidyl ester (CFSE) was observed post primary infection (PPI) and post reinfection (PR) of BALB/c mice. Each infection was performed with 1,000 larvae per mouse. Primary infections were performed with labeled larvae, while for challenge infections the reinfecting larvae were stained by CFSE. The worm burden in mouse organs was determined during a period from 6 h to 21 days and 4 months PPI and PR. In comparison with primary infections that led to the first larvae appearance in the brain after 60 h, greatly accelerated migration of the parasites administered 3 weeks PPI to the CNS and eyes of challenged mice was noted—in both organs the larvae appeared 6 h PR. In all challenged mice, reinfecting larvae prevailed in the resident parasite population. Preliminary experiments with Toxocara cati larvae also revealed early brain involvement in primarily infected mice. Staining of T. canis larvae by CFSE had no effect on the development of a humoral antibody response against T. canis excretory–secretory antigens. In ELISA, elevated levels of specific IgG and IgG1 were noted on day 14 PPI and the levels of antibodies increased till the end of experiment. Reinfection induced an increase in the levels of both antibodies. In terms of optical density, IgG1 antibodies gave higher values in all sera examined. In ELISA for IgG antibodies, an increase in the avidity index of around 50% was detected 1 month PPI; higher-avidity antibodies were also detected in sera of reinfected animals.     

Cytokine-dependent activation of small hepatocyte-like progenitor cells in retrorsine-induced rat liver injury

Complete liver regeneration after partial hepatectomy (PH) in rats exposed to the pyrrolizidine alkaloid retrorsine is accomplished through the activation, expansion, and differentiation of a population of small hepatocyte-like progenitor cells (SHPCs). The mechanism(s) governing activation of SHPCs after PH in retrorsine-injured rats has not been investigated. We examined the possibility that SHPCs require cytokine priming prior to becoming growth factor responsive in this model of liver injury and regeneration. Male Fischer 344 rats were treated with retrorsine (30 mg/kg ip) at 6 and 8 weeks of age. Retrorsine-exposed and age-matched control rats were randomized into dexamethasone-treated and no DEX groups. DEX-treated animals were either given a single dose of DEX (2 mg/kg ip) at the time of PH or multiple DEX treatments (2 mg/kg ip each) at 24 and 1 h before PH and 1, 2, and 3 days post-PH. A subset of rats received 10 μg of recombinant IL6 protein, administered intravenously 30 min after PH. Liver tissues were harvested at 7, 14, 21, and 30 days post-PH. Treatment of retrorsine-exposed rats with the cytokine inhibitor dexamethasone (DEX) effectively blocked the emergence of SHPCs resulting in an inhibition of liver regeneration and producing significant short-term mortality. The livers of DEX-treated retrorsine-exposed rats displayed decreased numbers and smaller SHPC clusters compared to retrorsine-exposed rats in the absence of DEX treatment. Administration of recombinant IL6 to DEX-treated retrorsine-exposed rats restored the emergence of SHPCs and SHPC-mediated regenerative response. The livers of DEX-treated retrorsine-exposed rats that received IL6 displayed numbers of expanding SHPC clusters comparable to that of retrorsine-exposed rats in the absence of DEX treatment. These results combine to suggest that SHPC activation after PH in retrorsine-exposed rats is cytokine dependent and may specifically require IL6.     

The Effect of Two Glucan Carboxymethyl Derivatives with Various Substitution Degrees on Cyclophosphamide Immunosuppression in Mice

Carboxymethylglucan (CMG)¹ in two different degrees of substitution of carboxymethyl groups (0.56 and 0.89) was administered to cyclophoshamide (CY) treated (200 mg/kg) C57B1/6 mice in three doses (10, 50, and 100 mg/kg) 24 h after CY. The influence of CMG administration on the cell suppression caused by CY was observed in the subsequent days. The cellularity of spleen, bone marrow and peripheral blood was quantified on days 2, 5, 8, 11, 15, and 21 after CY treatment.

CY treated mice developed a significant decrease in peripheral blood cell counts, and spleen and bone marrow cellularity during the initial 5 days, followed by recovery in the next 15 days, with an overshoot reaction in spleen cellularity and erythrocyte levels.

The initial cellularity depression and the following recovery was modified by both carboxymethyl derivatives of glucan. Cyclophosphamide treated mice exhibited less pronounced immunosuppression and more rapid hematopoietic recovery when administered with CMG, althought this reaction was only of a modest degree. The effects were not dose dependent and the differences between the two glucans were not significant.     

Failure of combination therapy with imidocarb dipropionate and toltrazuril to clear <Emphasis Type="Italic">Hepatozoon canis</Emphasis> infection in dogs

Current treatments with imidocarb dipropionate for infected dogs with Hepatozoon canis do not always provide parasitological cure. The objective of this study is to determine whether concomitant use of toltrazuril may potentiate the effect of imidocarb dipropionate in the management of H. canis infection (HCI). Twelve dogs were determined to have naturally HCI based on clinical signs, identification of the parasite in blood smears, and serologic assay. The animals were allocated randomly to one of two groups (n = 6 in each group). Dogs in Imi group were given imidocarb dipropionate at a dose of 6 mg/kg body weight subcutaneously in two injections 14 days apart. Imi plus Toltra group was given imidocarb dipropionate as dose mentioned above and toltrazuril at 10 mg/kg/day orally for the first five treatment days. Clinical findings, blood counts and parasitaemia levels in blood before and 14, 28 and 56 days after the initial treatment were performed to evaluate treatment response. The overall clinical efficacy of imidocarb dipropionate with and without toltrazuril was 83.3% and 66.7%, respectively; with a mean recovery time of 21.0 and 25.6 days, respectively. A substantial main effect of time on mean PCV, Hb, WBC, neutrophil and PLT and gradual reduction of parasitaemia were significantly observed in both groups (P < 0.05), whereas no significant difference was noticed between the studied protocols. The parasitologic cure rate at the end of eight weekly observation period was 16.6% and 33.3% in Imi and Imi plus Toltra groups, respectively. Similar clinicopathologic and parasitologic responses were observed in both treated groups; thus, it was concluded that toltrazuril does not reveal additional benefit to imidocarb therapy in dogs with HCI.     

Antiplasmodial activity of Xanthium strumarium against Plasmodium berghei-infected BALB/c mice

The present work was undertaken to evaluate the antiplasmodial activity of ethanolic leaves extract of traditional medicinal plant Xanthium strumarium in Plasmodium berghei-infected BALB/c mice along with phytochemical screening and acute toxicity test to support its traditional medicinal use as a malaria remedy. The ethanolic leaves extract of X. strumarium (ELEXS) 150, 250, 350 and 500 mg/kg/day demonstrated dose-dependent chemosuppression during early and established infection long with significant (p < 0.001) repository activity. The oral administration of 500 mg/kg/day concentration showed a maximum of 88.6% chemosuppression during early infection, which was more than that of the standard drug chloroquine (5 mg/kg/day) with 88.3% chemosuppression. However, 60% mortality has been found in this group. The LD₅₀ of ELEXS was found to be 1.5 g/kg/mouse. The administration of 350 mg/kg/day concentration of extract have been found to exert 90.40% chemosuppression during repository infection, which was well comparable to standard drug pyrimethamine (1.2 mg/kg/day) exerting 92.91% chemosuppression. The extract has been found to enhance mean survival time of mice from 21 to 26 days with 250 and 350 mg/kg/day concentrations, while 150 mg/kg/day concentration has been found to sustain all the mice up to 29 days which was similar to the employed standard drug chloroquine (5 mg/kg/day). All these findings support the ethanopharmacological use of X. strumarium as malarial remedy and indicate the potential of plant for active antiplasmodial components.     

Efficacy of artesunate and artemether against <Emphasis Type="Italic">Clonorchis sinensis</Emphasis> in rabbits

Artesunate and artemether display promising clonorchicidal properties in rats. In this study, we assessed the efficacy of artesunate and artemether against Clonorchis sinensis in rabbits. Rabbits were each fed with 300 C. sinensis metacercariae. At day 28 postinfection, the rabbits were administered oral artesunate at doses of 7.5–120 mg/kg and oral artemether of 15–120 mg/kg. Two groups of rabbits were treated with single oral praziquantel at 75 and 150 mg/kg. Untreated rabbits served as controls. Fourteen days after treatment, all rabbits were sacrificed, and C. sinensis adults were collected from the bile ducts and counted. At the highest doses tested (120 mg/kg) artesunate and artemether achieved statistical significant worm burden reductions of 88.8% and 67.2%, respectively. These rates were lower than worm burden reductions observed with praziquantel (88% and 100%, respectively). It is suggested that artesunate and artemether have moderate anthelminthic efficacy against C. sinensis in rabbits.     

Efficacy of Emodepside plus Praziquantel Tablets (Profender? Tablets for Dogs) against Mature and Immature Infections with Toxocara canis and Toxascaris leonina in Dogs

The efficacy of emodepside plus praziquantel tablets (Profender? tablets for dogs) against mature adult, immature adult and larval stages of Toxocara canis and Toxascaris leonina was evaluated in ten randomised, blinded and placebo-controlled dose confirmation studies in naturally or experimentally infected dogs. The tablets were used at the proposed minimum dose of 1 mg emodepside and 5 mg praziquantel per kg body weight. Efficacy was calculated based on worm counts after necropsy. Five studies demonstrated >99% efficacy against mature adult, >92% efficacy against immature adult, >98% efficacy against L4 and >94% efficacy against L3 larval stages of T. canis. Another five studies demonstrated >99% efficacy against mature and immature adult and >95% efficacy against L4 larval stages of T. leonina. No side effects of the treatment were observed. Emodepside plus praziquantel tablets thus provide a comprehensive new treatment option for ascarid infections in the dog.     

Fungus dose-dependent primary pulmonary aspergillosis in immunosuppressed mice.

We report on a model of primary pulmonary aspergillosis occurring after intranasal instillation of concentrated suspensions of conidia of Aspergillus fumigatus in immunocompromised mice. Unconcentrated suspensions of inoculum contained ca. 2 x 10(7) conidia per ml (1x). These suspensions were concentrated by centrifugation, adjusted to give ca. 2 x 10(8) (10x) or 2 x 10(9) (100x) conidia per ml, and delivered in 30-microliters droplets to the nares of anesthetized mice. Mice were untreated or injected with cortisone acetate (CA) or cyclophosphamide (CY) in various dosage regimens. It was not possible to obtain mortality of more than 50% with sublethal immunosuppressive treatment and 1x fungus. In contrast, mortality followed a fungus dose response in mice receiving sublethal immunosuppression with either CA or CY. Mortality rates of up to 100% were obtained with 100x fungus and a single dose of CY (200 mg/kg) or CA (250 mg/kg) or three alternate doses (125 mg/kg per day) of CA prior to infection. This model is applicable to the study of acute, fatal primary pulmonary aspergillosis and chemotherapy trials.     

The effect of combined inositol hexakisphosphate and inositol supplement in streptozotocin‐induced type 2 diabetic rats

Inositol hexakisphosphate (IP6) and inositol both regulate insulin secretion, but their combined use in the management of diabetes deserves investigation. The combined effects of IP6 and inositol supplementation were investigated in streptozotocin‐induced type 2 diabetic rats. The following groups of rats were studied for 8 weeks: non‐diabetic control, non‐diabetic high‐fat diet control, diabetic untreated, diabetic rats treated with the combination of IP6 and inositol (650 mg/kg bw) and diabetic rats treated with glibenclamide (10 mg/kg bw). High‐fat diet and streptozotocin were used to induce type 2 diabetes mellitus in Sprague–Dawley rats. Body weight, blood glucose, glycated haemoglobin, insulin, serum leptin, HOMA‐insulin resistance scores, intestinal amylase activity, serum and faecal lipids and food and fluid consumption were measured. Treatment with the combination significantly reduced blood glucose (306 ± 53 mg/dl) and insulin resistance score (1.93 ± 0.45) compared with diabetic controls (522 ± 24 mg/dl and 5.1 ± 0.69 respectively). Serum leptin (2.8 ± 0.6 ng/dl) and faecal triglycerides (108 ± 8 mg/dl) were significantly increased in rats treated with the combination compared with the diabetic control (1.8 ± 0.06 ng/dl and 86 ± 4 mg/dl). Serum triglyceride (47 ± 5.1 mg/dl), total cholesterol (98 ± 3.2 mg/dl) and food intake (26 ± 0.3 g) were significantly reduced by 45%, 25% and 25%, respectively, in rats treated with the combination compared with the diabetic control. Inositol and IP6 combined supplementation may be effective in the management of type 2 diabetes mellitus and related metabolic disorders by regulating some aspects of lipid and carbohydrate metabolism.     

Matrix metalloproteinases activation in Toxocara canis induced pulmonary pathogenesis

BackgroundToxocara canis, a source of visceral larva migrans, causes toxocariasis and induces respiratory symptoms. The reasons by which the pulmonary pathological alteration in the lungs infected with T. canis remain unclear.MethodsThe involvement of the pulmonary pathological alteration by histology, enzyme activity, and Western blot analysis in the lungs of BALB/c mice after the infection of 2000 embryonated eggs.ResultsThe pathological effects gradually increased after the infection culminated in severe leukocyte infiltration and hemorrhage from days 4–14 post-inoculation. Gelatin zymography using substrate showed that the relative activity of matrix metalloproteinase (MMP) −9 and MMP-2 significantly increased in T. canis-infected mice. Western blot analysis indicated that the MMPs protein level of fibronectin monomer significantly increased in T. canis-infected mice compared with that in uninfected control. T. canis larvae mainly initiated leukocyte infiltration and hemorrhage in the lungs.ConclusionThese phenomena subsequently induced the activities of MMPs in parallel with the pathological changes in early stage pulmonary inflammation. In conclusion, T. canis larval migration activated the MMPs and caused pulmonary pathogenesis.     

Effect of various doses of infectiveToxocara canis andToxocara cati eggs on the humoral response and distribution of larvae in mice

The effect of 5–2,500 infectiveToxocara canis and 5–1,000T. cati eggs on the humoral immune response and on the distribution of larvae in the organism was studied in paratenic hosts — inbred C57BL6/J mice. With each dose ofT. canis eggs the maximal antibody level was recorded on day 56 post infection and was followed by a moderate decline that lasted until day 154 of the experiment. A correlation between the antibody level and the egg count was observed only with the infective dose of 5–50 eggs. A more rapid occurrence of antibodies was recorded in mice infected with a high dose of eggs. In those given 5 and 7T. cati eggs the antibody level exceeded the extinction threshold value only from day 21 to day 84. Low doses ofT. canis (n=5) andT. cati (n=7) eggs caused a comparable distribution of larvae in mice, and the larval recoveries on day 70 post infection ranged between 10.00% and 25.74%. Following a dose of 500T. cati eggs, 22.28% of the larvae were recovered, although only 1.08% were localized in the brain. A dose of 1,000T. canis eggs yielded, 36.37% of the larvae, with as much as 28.13% being found in the brain.