Toxocariasis is a helminthic zoonosis due to the presence in the human body of larvae of Toxocara sp., roundworms of the Ascaridae family. Less than 50 cases of central involvement related to toxocarasis have been rep...Toxocariasis is a helminthic zoonosis due to the presence in the human body of larvae of Toxocara sp., roundworms of the Ascaridae family. Less than 50 cases of central involvement related to toxocarasis have been reported in immunocompetent individuals. This involvement can result in epilepsy, meningoencephalitis, myelitis or encephalopathy. The standard treatment is albendazole at a dosage of 10 to 15 mg/kg/day. The duration of treatment varies greatly depending on the clinical cases reported, ranging from 5 days to several weeks in the case of severe forms. We report a case of myelitis due to Toxocara canis in a 14-year-old patient admitted for gait disorders. The laboratory assessment shows isolated hypereosinophilia at 8000 elements per mm3. Medullary magnetic resonance imaging (MRI) showed an intradural process of inflammatory and infectious appearance extended between T10 and L1 levels, hypointense in T1, hyperintense in T2, and homogeneous. Parasitological analysis of the stools noted the presence of high concentrations of Toxocara canis. Serology by ELISA (enzyme-linked immunosorbent assay) is strongly positive for toxocariasis, and western blot confirms the presence of antibodies directed against Toxocara larvae. Treatment with albendazole 400 mg × 2/day for 10 days associated with corticosteroid therapy (prednisone 50 mg/day for 5 days) allowed the disappearance of pain in 8 days, normalization of eosinophilia and improvement of walking.展开更多
We evaluated thirteen eyes of twelve patients diagnosed clinically and serologically with Toxocara optic neuropathy. Eleven patients had unilateral involvement and one patient had bilateral optic neuropathy. Eight pat...We evaluated thirteen eyes of twelve patients diagnosed clinically and serologically with Toxocara optic neuropathy. Eleven patients had unilateral involvement and one patient had bilateral optic neuropathy. Eight patients （66.7%） had a possible infection source to Toxocara. Six patients （50%） had painless acute optic neuropathy. Ten eyes had asymmetric, sectorial optic disc edema with peripapillary infiltration and three eyes had diffuse optic disc edema. Eosinophilia was noted in five patients （41.7%） and optic nerve enhancement was observed in eight of eleven eyes （72.7%） with available orbit magnetic resonance imaging （MRI）. Mean visual acuity significantly improved following treatment [mean logarithmic of the minimum angle of resolution （IogMAR） 0.94±0.56 at baseline and 0.47±0.59 at the final （P=0.02）]. Asymmetric optic disc edema with a peripapillary lesion and a history of raw meat ingestion were important clues for diagnosing Toxocara optic neuropathy. Additionally, Toxocara IgG enzymelinked immunosorbent assay （ELISA） test and evaluating eosinophil may be helpful for diagnosis.展开更多
Objective: To determine exon/intron organization of the Toxocara canis(T. canis) AK(TCAK) and to test green and black tea and several other chemicals against the activity of recombinant TCAK in the guanidino-specific ...Objective: To determine exon/intron organization of the Toxocara canis(T. canis) AK(TCAK) and to test green and black tea and several other chemicals against the activity of recombinant TCAK in the guanidino-specific region by site-directed mutants. Methods: Amplification of genomic DNA fragments containing introns was carried out by PCRs. The open-reading frame(1 200 bp) of TCAK(wild type) was cloned into the BamH 1/SalI site of pM AL-c2X. The maltose-binding protein-TCAK fusion protein was expressed in Escherichia coli TB1 cells. The purity of the expressed enzyme was verified by SDS-PAGE. Mutations were introduced into the guanidino-specific region and other areas of pM AL/TCAK by PCR. Enzyme activity was measured with an NADH-linked assay at 25℃ for the forward reaction(phosphagen synthesis). Results: Arginine kinase in T. canis has a seven-exon/six-intron gene structure. The lengths of the introns ranged from 542 bp to 2 500 bp. All introns begin with gt and end with ag. Furthermore, we measured the enzyme activity of site-directed mutants of the recombinant TCAK. The K_m value of the mutant(Alanine to Serine) decreased indicating a higher affinity for substrate arginine than the wild-type. The K_m value of the mutant(Serine to Glycine) increased to 0.19 mM. The Km value(0.19 mM) of the double mutant(Alanine-Serine to Serine-Glycine) was slightly greater than in the wild-type(0.12 mM). In addition, several other chemicals were tested; including plant extract Azadiracta indica(A. indica), an aminoglycoside antibiotic(aminosidine), a citrus flavonoid glycoside(rutin) and a commercially available catechin mixture against TCAK. Green and black tea(1:10 dilution) produced 15% and 25% inhibition of TCAK, respectively. The extract of A. indica produced 5% inhibition of TCAK. Moreover, green and black tea produced a non-competitive type of inhibition and A. indica produced a mixed-type of inhibition on TCAK. Conclusions: Arginine kinase in T. canis has a seven-exon/six-intron gene structure. However, further studies are needed to identify a specific compound within the extract causing the inhibitory effect and also to determine the molecular mechanisms behind inhibition of arginine kinase in T. canis.展开更多
Toxocara canis(T.canis)is one of the most important zoonotic parasites of dogs.The aim of the present study was to perform an in vitro analysis of the effect of Milbemycin oxime on T.canis eggs following exposure to a...Toxocara canis(T.canis)is one of the most important zoonotic parasites of dogs.The aim of the present study was to perform an in vitro analysis of the effect of Milbemycin oxime on T.canis eggs following exposure to a concentration gradient of the drug and to determine the inflammatory reaction produced by the infective T.canis larvae in mice.The present study was undertaken using the model nematode,T.canis,to investigate the effect of Milbemycin oxime on T.canis eggs and larvae.T.canis eggs were exposed to a concentration gradient of Milbemycin oxime in vitro,the higher concentration of Milbemycin oxime was,the lower percentage of infective stage larvae was.Light micrographs showed that Milbemycin oxime induced eggs dissolved and eggshell broken.Histological analyses of mice that stained with hematoxylin and eosin(H&E)showed in lower dosing(10-7 and 10-8 g·mL-1)drug-treated groups,atrophy of alveolar space and interalveolar septum thickening appeared,inflammatory infiltrates accompanied with erythrocytes around blood vessels and bronchioles presented.In higher dosing(10-6,10-5 and 10-4 g·mL-1)drug-treated groups,low-grade or no pathological changes occurred,indicating that Milbemycin oxime could obviously decrease the inflammatory reaction produced by the infection of T.canis larvae in vivo.展开更多
The frequency of the infective larvae of Toxocara canis, the common parasite of the dog was assessed in brain portions of male Albino mice ingested two doses： 200 mg/Kg and 400 mg/Kg of potassium dichromate-hexavale...The frequency of the infective larvae of Toxocara canis, the common parasite of the dog was assessed in brain portions of male Albino mice ingested two doses： 200 mg/Kg and 400 mg/Kg of potassium dichromate-hexavalent （VI） as an indicator. Only 2,000 ova of the parasite were inoculated orally to twenty seven healthy young male mice. Frequency of the parasite was tested 13 weeks post-inoculation. Using bio-statistical analysis （one way analysis of variance） the frequency of detected larvae of both doses in the brain portions of the experimental animals showed an insignificant difference （P〉 0.05） in comparison with control. The results indicate the safety of small and mild intoxication doses of the potassium dichromate on distribution of Toxocara canis in brain portions of mice.展开更多
Human infection of Toxocara canis in eye is usually an outcome of accidental ingestion of the embryonated eggs. The average age at diagnosis of ocular Toxocariasis is 7.5 years, ranging from 2 to 31 years. It constitu...Human infection of Toxocara canis in eye is usually an outcome of accidental ingestion of the embryonated eggs. The average age at diagnosis of ocular Toxocariasis is 7.5 years, ranging from 2 to 31 years. It constitutes 1%-2% of uveitis in children. Diagnosis is based upon the clinical features observed in a young patient and confirmed by the presence of specific Ig G in the serum or aqueous humor by Enzyme-linked immunosorbent assay test. We report a case of Presumed Toxocara infection in 45-year-old male which is unique in presentation with multifocal granulomata in retina. Our Pub Med search could not produce case with similar presentation. Probably this is the first reported case of multifocal granulomata in presumed ocular Toxocara in any age展开更多
Background Toxocara canis,the most prevalent helminth in dogs and other canines,is one of the socioeconomically important zoonotic parasites,particularly affecting pediatric and adolescent populations in impoverished ...Background Toxocara canis,the most prevalent helminth in dogs and other canines,is one of the socioeconomically important zoonotic parasites,particularly affecting pediatric and adolescent populations in impoverished communities.However,limited information is available regarding the proteomes of female and male adult T.canis.To address this knowledge gap,we performed a comprehensive proteomic analysis to identify the proteins with differential abundance(PDAs)and gender-specifically expressed proteins between the two sexes adult T.canis.Methods The comparative proteomic analysis was carried out by the Orbitrap mass spectrometry(MS)with asymmetric track lossless(Astral)analyzer.The difference analysis was conducted using t-test and the proteins verification was achieved through parallel reaction monitoring(PRM).The potential biological functions of identified adult T.canis proteins and PDAs were predicted by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)databases.The domain,transcription factor and subcellular localization of the identified proteins and PDAs were analyzed by InterPro,AnimalTFDB 4.0 and Cell-mPLOC 2.0 databases,respectively.Results A total of 8565 somatic proteins of adult T.canis were identified.Compared to male adult,682 up-regulated PDAs and 844 down-regulated PDAs were identified in female adult with P-values<0.05 and|log2FC|>1,including 139 proteins exclusively expressed in female and 272 proteins exclusively expressed in male.The GO annotation analysis using all PDAs revealed that the main biological processes,cellular components and molecular functions corresponded to aminoglycan metabolic process,extracellular region and protein tyrosine phosphatase activity,respectively.The KEGG analysis using all PDAs showed that the pathways were mainly associated with adipocytokine signaling pathway,proximal tubule bicarbonate reclamation and PPAR signaling pathway.Conclusions This study reveals the differential protein expression between female and male adult T.canis,providing valuable resource for developing the novel intervention strategies against T.canis infection in humans and animals,especially from the perspective of sexual development and reproduction.展开更多
文摘Toxocariasis is a helminthic zoonosis due to the presence in the human body of larvae of Toxocara sp., roundworms of the Ascaridae family. Less than 50 cases of central involvement related to toxocarasis have been reported in immunocompetent individuals. This involvement can result in epilepsy, meningoencephalitis, myelitis or encephalopathy. The standard treatment is albendazole at a dosage of 10 to 15 mg/kg/day. The duration of treatment varies greatly depending on the clinical cases reported, ranging from 5 days to several weeks in the case of severe forms. We report a case of myelitis due to Toxocara canis in a 14-year-old patient admitted for gait disorders. The laboratory assessment shows isolated hypereosinophilia at 8000 elements per mm3. Medullary magnetic resonance imaging (MRI) showed an intradural process of inflammatory and infectious appearance extended between T10 and L1 levels, hypointense in T1, hyperintense in T2, and homogeneous. Parasitological analysis of the stools noted the presence of high concentrations of Toxocara canis. Serology by ELISA (enzyme-linked immunosorbent assay) is strongly positive for toxocariasis, and western blot confirms the presence of antibodies directed against Toxocara larvae. Treatment with albendazole 400 mg × 2/day for 10 days associated with corticosteroid therapy (prednisone 50 mg/day for 5 days) allowed the disappearance of pain in 8 days, normalization of eosinophilia and improvement of walking.
文摘We evaluated thirteen eyes of twelve patients diagnosed clinically and serologically with Toxocara optic neuropathy. Eleven patients had unilateral involvement and one patient had bilateral optic neuropathy. Eight patients （66.7%） had a possible infection source to Toxocara. Six patients （50%） had painless acute optic neuropathy. Ten eyes had asymmetric, sectorial optic disc edema with peripapillary infiltration and three eyes had diffuse optic disc edema. Eosinophilia was noted in five patients （41.7%） and optic nerve enhancement was observed in eight of eleven eyes （72.7%） with available orbit magnetic resonance imaging （MRI）. Mean visual acuity significantly improved following treatment [mean logarithmic of the minimum angle of resolution （IogMAR） 0.94±0.56 at baseline and 0.47±0.59 at the final （P=0.02）]. Asymmetric optic disc edema with a peripapillary lesion and a history of raw meat ingestion were important clues for diagnosing Toxocara optic neuropathy. Additionally, Toxocara IgG enzymelinked immunosorbent assay （ELISA） test and evaluating eosinophil may be helpful for diagnosis.
文摘Objective: To determine exon/intron organization of the Toxocara canis(T. canis) AK(TCAK) and to test green and black tea and several other chemicals against the activity of recombinant TCAK in the guanidino-specific region by site-directed mutants. Methods: Amplification of genomic DNA fragments containing introns was carried out by PCRs. The open-reading frame(1 200 bp) of TCAK(wild type) was cloned into the BamH 1/SalI site of pM AL-c2X. The maltose-binding protein-TCAK fusion protein was expressed in Escherichia coli TB1 cells. The purity of the expressed enzyme was verified by SDS-PAGE. Mutations were introduced into the guanidino-specific region and other areas of pM AL/TCAK by PCR. Enzyme activity was measured with an NADH-linked assay at 25℃ for the forward reaction(phosphagen synthesis). Results: Arginine kinase in T. canis has a seven-exon/six-intron gene structure. The lengths of the introns ranged from 542 bp to 2 500 bp. All introns begin with gt and end with ag. Furthermore, we measured the enzyme activity of site-directed mutants of the recombinant TCAK. The K_m value of the mutant(Alanine to Serine) decreased indicating a higher affinity for substrate arginine than the wild-type. The K_m value of the mutant(Serine to Glycine) increased to 0.19 mM. The Km value(0.19 mM) of the double mutant(Alanine-Serine to Serine-Glycine) was slightly greater than in the wild-type(0.12 mM). In addition, several other chemicals were tested; including plant extract Azadiracta indica(A. indica), an aminoglycoside antibiotic(aminosidine), a citrus flavonoid glycoside(rutin) and a commercially available catechin mixture against TCAK. Green and black tea(1:10 dilution) produced 15% and 25% inhibition of TCAK, respectively. The extract of A. indica produced 5% inhibition of TCAK. Moreover, green and black tea produced a non-competitive type of inhibition and A. indica produced a mixed-type of inhibition on TCAK. Conclusions: Arginine kinase in T. canis has a seven-exon/six-intron gene structure. However, further studies are needed to identify a specific compound within the extract causing the inhibitory effect and also to determine the molecular mechanisms behind inhibition of arginine kinase in T. canis.
基金Supported by the Post-doctoral Research Foundation of Heilongjiang Province(LBH-Q18019)。
文摘Toxocara canis(T.canis)is one of the most important zoonotic parasites of dogs.The aim of the present study was to perform an in vitro analysis of the effect of Milbemycin oxime on T.canis eggs following exposure to a concentration gradient of the drug and to determine the inflammatory reaction produced by the infective T.canis larvae in mice.The present study was undertaken using the model nematode,T.canis,to investigate the effect of Milbemycin oxime on T.canis eggs and larvae.T.canis eggs were exposed to a concentration gradient of Milbemycin oxime in vitro,the higher concentration of Milbemycin oxime was,the lower percentage of infective stage larvae was.Light micrographs showed that Milbemycin oxime induced eggs dissolved and eggshell broken.Histological analyses of mice that stained with hematoxylin and eosin(H&E)showed in lower dosing(10-7 and 10-8 g·mL-1)drug-treated groups,atrophy of alveolar space and interalveolar septum thickening appeared,inflammatory infiltrates accompanied with erythrocytes around blood vessels and bronchioles presented.In higher dosing(10-6,10-5 and 10-4 g·mL-1)drug-treated groups,low-grade or no pathological changes occurred,indicating that Milbemycin oxime could obviously decrease the inflammatory reaction produced by the infection of T.canis larvae in vivo.
文摘The frequency of the infective larvae of Toxocara canis, the common parasite of the dog was assessed in brain portions of male Albino mice ingested two doses： 200 mg/Kg and 400 mg/Kg of potassium dichromate-hexavalent （VI） as an indicator. Only 2,000 ova of the parasite were inoculated orally to twenty seven healthy young male mice. Frequency of the parasite was tested 13 weeks post-inoculation. Using bio-statistical analysis （one way analysis of variance） the frequency of detected larvae of both doses in the brain portions of the experimental animals showed an insignificant difference （P〉 0.05） in comparison with control. The results indicate the safety of small and mild intoxication doses of the potassium dichromate on distribution of Toxocara canis in brain portions of mice.
文摘Human infection of Toxocara canis in eye is usually an outcome of accidental ingestion of the embryonated eggs. The average age at diagnosis of ocular Toxocariasis is 7.5 years, ranging from 2 to 31 years. It constitutes 1%-2% of uveitis in children. Diagnosis is based upon the clinical features observed in a young patient and confirmed by the presence of specific Ig G in the serum or aqueous humor by Enzyme-linked immunosorbent assay test. We report a case of Presumed Toxocara infection in 45-year-old male which is unique in presentation with multifocal granulomata in retina. Our Pub Med search could not produce case with similar presentation. Probably this is the first reported case of multifocal granulomata in presumed ocular Toxocara in any age
文摘Background Toxocara canis,the most prevalent helminth in dogs and other canines,is one of the socioeconomically important zoonotic parasites,particularly affecting pediatric and adolescent populations in impoverished communities.However,limited information is available regarding the proteomes of female and male adult T.canis.To address this knowledge gap,we performed a comprehensive proteomic analysis to identify the proteins with differential abundance(PDAs)and gender-specifically expressed proteins between the two sexes adult T.canis.Methods The comparative proteomic analysis was carried out by the Orbitrap mass spectrometry(MS)with asymmetric track lossless(Astral)analyzer.The difference analysis was conducted using t-test and the proteins verification was achieved through parallel reaction monitoring(PRM).The potential biological functions of identified adult T.canis proteins and PDAs were predicted by Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)databases.The domain,transcription factor and subcellular localization of the identified proteins and PDAs were analyzed by InterPro,AnimalTFDB 4.0 and Cell-mPLOC 2.0 databases,respectively.Results A total of 8565 somatic proteins of adult T.canis were identified.Compared to male adult,682 up-regulated PDAs and 844 down-regulated PDAs were identified in female adult with P-values<0.05 and|log2FC|>1,including 139 proteins exclusively expressed in female and 272 proteins exclusively expressed in male.The GO annotation analysis using all PDAs revealed that the main biological processes,cellular components and molecular functions corresponded to aminoglycan metabolic process,extracellular region and protein tyrosine phosphatase activity,respectively.The KEGG analysis using all PDAs showed that the pathways were mainly associated with adipocytokine signaling pathway,proximal tubule bicarbonate reclamation and PPAR signaling pathway.Conclusions This study reveals the differential protein expression between female and male adult T.canis,providing valuable resource for developing the novel intervention strategies against T.canis infection in humans and animals,especially from the perspective of sexual development and reproduction.
