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PubMed1997

The effects of the peptides AF3 (AVPGVLRFamide) and AF4 (GDVPGVLRFamide) on the somatic muscle of the parasitic nematodes Ascaris suum and Ascaridia galli.

AF3 (AVPGVLRFamide) and AF4 (GDVPGVLRFamide) are endogenous RFamide-like peptides isolated from the parasitic nematode Ascaris suum. Here the actions of these peptides on the somatic musculature of Ascaris have been investigated and compared to the action of acetylcholine (ACh), the excitatory transmitter at the neuromuscular junction. ACh, AF3 and AF4 contracted muscle with EC50S of 13 +/- 1 microM, 24 +/- 6 nM and 37 +/- 2 nM, respectively (n = 6). The muscle cells were depolarized by ACh (3 microM; 5.2 +/- 0.4 mV, n = 42), AF3 (1 microM; 2.6 +/- 0.3 mV, n = 19) and AF4 (1 microM; 3.3 +/- 0.4 mV, n = 19). EC50S were 681 +/- 329 nM (AF3) and 901 +/- 229 nM (AF4), but an estimate could not be made for ACh due to muscle contraction at concentrations greater than 10 microM. The depolarization to 3 microM ACh was abolished by the nicotinic receptor antagonist mecamylamine (10 microM; n = 5) but the responses to the peptides were not (111 +/- 7% and 108 +/- 17% with respect to control; n = 5). The depolarization elicited by ACh was reduced to a greater extent by a 50% reduction in extracellular Na+ concentration than the response to AF3 and AF4 (P < 0.02). Cobalt was more effective at blocking the AF3 and AF4 depolarizations than those to ACh. These observations suggest that AF3 and AF4 contract Ascaris muscle without an action at the Ascaris nicotinic receptor. Furthermore, the ionic mechanism through which AF3 and AF4 depolarize Ascaris muscle is different from that for ACh. ACh, AF3 and AF4 were also found to contract Ascaridia galli somatic muscle with EC50S of 13 +/- 3 microM, 721 +/- 236 nM and 371 +/- 177 nM, respectively (n = 7). The muscle cells were depolarized by ACh (EC50 = 14 +/- 5 microM, n = 5), AF3 (EC50 = 5 +/- 3 microM, n = 4) and AF4 (EC50 = 10 +/- 5 microM, n = 4). Therefore the response to these peptides is not unique to Ascaris and they may subserve a functional role in the motor nervous system of parasitic nematodes.

Acetylcholine↗
PubMed2004

An asthma-associated genetic variant of STAT6 predicts low burden of ascaris worm infestation.

Th-2 immune mechanisms are involved in the pathology of asthma and in the protective immune response to parasitic worms. Common upregulating genetic variants of Th-2 immune signalling are risk factors for asthma, and we tested whether they may confer a counteradvantage in protecting against parasitic worms. We examined the intensity of infection by the parasitic worm, Ascaris lumbricoides, by microsopic counting of ascaris eggs in the stool of 614 schoolchildren from an area of endemic ascaris infection in China. We investigated the relationship between the intensity of ascaris infection and common, asthma-associated genetic variants of Th-2 and Th-1 immune signalling. Ascaris egg counts per gram of stool (epg), mean 1068 epg, ranged from barely detectable (<240 epg) to heavy (approximately 9600 epg) in a skewed distribution. Logistic regression, after exploratory discriminant analysis, showed a major association between a common genetic variant of the 3'-UTR regulatory elements of the signal transducer and transactivating factor (STAT6) (P=0.0002) and egg counts, at the 77 th centile. Linear regression after log transformation of egg counts confirmed a highly significant association with this STAT6 variant (P=0.001). Thus, a common, asthma-associated, genetic variant of the pivotal transduction and transactivating factor for Th-2 immune signalling, STAT6, predicts increased resistance to ascaris worm infection. The evolution of enhanced resistance to parasitic worm infection, through human genetic variation in Th-2 immune signalling, may represent one origin for asthma.

3' Untranslated Regions↗
PubMed1991

The pharmacology of cholinoceptors on the somatic muscle cells of the parasitic nematode Ascaris suum.

1. Acetylcholine (ACh) elicited depolarization and an increase in input conductance of the somatic muscle cells of the parasitic nematode Ascaris suum. 2. The relative potency of nicotinic and muscarinic agents was studied in this preparation. The order of potency of these compounds was metahydroxy-phenylpropyltrimethylammonium (HPPT) greater than 1.1 dimethyl-4-phenylpiperazinium (DMPP) greater than ACh greater than carbachol greater than nicotine greater than tetramethylammonium (TMA+) greater than muscarone greater than furtrethonium greater than arecoline. Decamethonium was also a weak agonist. McN-A-343 elicited a very weak depolarization at concentrations above 1 mmol l-1. Bethanechol and methacholine were without effect up to 1 mmol l-1. Pilocarpine and muscarine elicited a slight hyperpolarization of up to 3 mV with a threshold for the response of around 500 mumol l-1. Oxotremorine (1 mmol l-1) was without effect. 3. The nitromethylene insecticide 2(nitromethylene)tetrahydro 1,3-thiazine (NMTHT), an agonist at insect nicotinic receptors, was without effect on Ascaris muscle cells up to 1 mmol l-1. 4. Mecamylamine and benzoquinonium were the most potent antagonists of the acetylcholine response. The order of potency of the other antagonists was tetraphenylphosphonium (TPP) greater than quinacrine greater than pancuronium, curare greater than trimethaphan greater than atropine greater than chlorisondamine, decamethonium greater than hexamethonium greater than dihydro-beta-erythroidine. 5. The agonist profile of the Ascaris muscle cell ACh receptor clearly indicates that it is nicotinic. The potency of ganglionic and neuromuscular nicotinic receptor antagonists in Ascaris does not enable a further subclassification of this nicotinic receptor. The Ascaris nicotinic receptor seems to possess some of the pharmacological properties of each type of vertebrate nicotinic receptor. The pharmacology of the Ascaris nicotinic receptor is discussed in relation to that of nicotinic receptors in other invertebrate preparations and in vertebrate preparations.

Acetylcholine↗
PubMed1975

Specificity and sensitivity of skin test reactions to extracts of Toxocara canis and Ascaris suum. I. Skin tests done on infected guinea pigs.

The specificity and sensitivity of adult and larval somatic antigens, and perienteric fluid of Toxocara canis and Ascaris suum were investigated by using intradermal skin tests in guinea pigs. These animals were infected with low doses (0.01, 0.1 or 1.0 egg/g) of these helminths. Toxocara larval antigen (TL) induced larger reactions in Toxocara-infected animals than did the other antigens, suggesting a superior sensitivity for this antigen. In addition, Ascaris perienteric fluid (AP) provoked skin responses in these animals of a magnitude similar to those induced by TL. The reciprocal relationship, i.e., comparable reactivity of AP and TL in Ascaris-infected animals, was not apparent. In general, Ascaris larval antigen and AP elicited larger intradermal reactions than other antigens in Ascaris-infected animals. The results of this study indicated no superiority of adult antigens in differentiating Ascaris and Toxocara infections.

Animals↗
PubMed2005

[Antibody response to Ascaris lumbricoides among the children population in the Ustí Region].

A group of 156 children aged between 10 and 12 years were screened for IgG and IgE antibodies to Ascaris lumbricoides. The study subjects were 64 children of Romany origin and 92 children from the majority population. IgG antibodies to Ascaris lumbricoides were detected in 112 (71.8%) children. No difference in the prevalence of IgG antibodies was found between Romany children and those from the majority population. As many as 34.1% of the study subjects had IgE antibodies to Ascaris lumbricoides, again with no difference between the two ethnic groups. Children with IgG antibodies to Ascaris lumbricoides had significantly higher total IgE levels compared to those who had tested IgG negative. To demonstrate induction of a non-specific IgE response was one of the study objectives. The high prevalence rates of IgG and IgE antibodies to Ascaris lumbricoides are suggestive of a high frequency of cross- and non-specific reactions. Possible effect of cross-reactivity to other antigens on the specific IgG and IgE antibody response to Ascaris lumbricoides is discussed.

Animals↗
PubMed1989

Airway responses to inhaled Ascaris suum antigen in naturally sensitized beagle dogs.

To characterize the airway responses to inhaled Ascaris suum antigen in a group of adult Beagle dogs with cutaneous Ascaris sensitivity, 9 dogs were challenged with aerosolized Ascaris antigen and 6 were subsequently challenged 1 to 2 weeks later with aerosolized saline. Changes in lung resistance, dynamic lung compliance, and responsiveness to aerosolized histamine were measured during the ensuing 6 hours. Inhalation of Ascaris antigen produced immediate bronchoconstriction, but no spontaneous late bronchoconstrictive responses were noted. Two dogs demonstrated increased histamine responsiveness 6 hours after Ascaris challenge, and 4 dogs were histamine hyperresponsive 1 to 2 weeks later. We conclude that exposure to Ascaris antigen in naturally sensitized Beagle dogs produces an immediate asthmatic response and may result in airway hyperresponsiveness for several weeks. However, spontaneous late responses do not occur.

Airway Resistance↗
PubMed1979

Ascaris lumbricoides and allergic asthma: A new perspective.

Infestation of humans with the parasite Ascaris lumbricoides may induce high total serum IgE levels, but the influence of this immunogenic response on allergic asthma has not been defined. In this study, the specific antiparasitic IgE-mediated response as determined by skin-prick testing was related to the incidence of allergic asthma in Ascaris-infested patients. A limited number--17% of the non-allergic controls and 51% of the allergic asthmatics--had a clinically detectable immunogenic response to the parasite. The predicted incidence of asthma was significantly higher than the observed incidence in the subjects in whom the Ascaris skin test was positive. This was not found in subjects in whom the Ascaris skin test was negative. Inhalation of Ascaris antigen induced asthmatic reactions in 7 of 8 patients who were Ascaris-positive on skin testing, but not in the negative controls. The groups of patients who respond immunogenically to parasite infestation need to be defined, as they may be predisposed to allergic diseases such as asthma.

Adolescent↗
PubMed2001

Efficacy of DEC against Ascaris and hookworm infections in schoolchildren.

Diethylcarbamazine (DEC) is an important drug for treatment and control of lymphatic filariasis. To assess its possible effect on Ascaris and hookworm infections, we conducted a double-blind two-armed study with children in Tanzania. Twenty six Ascaris-infected children were given a single dose of DEC (6 mg/kg body weight) and 25 were given a placebo. Twenty children in the treatment group and eighteen controls were also infected with hookworms. One month after treatment the geometric mean intensity (GMI) of Ascaris egg output was reduced by 60.2% in the treatment group; two children (7.7%) had stopped excreting Ascaris eggs, and some Ascaris worms were also expelled. In hookworm-infected children in the treatment group, the geometric mean intensity of hookworm egg output was reduced by 6.7% 1 month after treatment. Neither for Ascaris nor for hookworm, however, was the observed reduction in egg output at 1 month after treatment statistically significant. The treatment efficacy of a single dose of DEC (6 mg/kg) in these infections therefore was low.

Adolescent↗
PubMed2001

[On cleanliness of hands in diminution of Ascaris lumbricoides infection in children].

OBJECTIVE: To study the relationship between cleanliness of children's hands and diminution of Ascaris lumbricoides infection. METHODS: Before the study all persons positive for ascaris eggs in the preliminary survey were treated with albendazole. Hand-washing habit before meal and after defecation was kept in children of experimental group, but not in the control group. Kato thick smear stool examination was done once every two months for one year to compare the new infection rates in children without ascaris infection in the two groups, and the reinfection rates in the cured negative cases were also compared between them in half a month after chemotherapy. RESULTS: All the new infection rates as well as reinfection rates of each reexamination in the experimental group were significantly lower than that of the control group (P < 0.001). Reexamination one year later showed that the ascaris infection rate of the experimental group was 35.2%, reducing by 48.5% as compared with 68.3% before the operation of the project; while ascaris infection rate of the control group was 73.7%, increasing by 78.0% as compared with 41.4% before the operation of the project. CONCLUSION: Washing hands with toilet soap to keep hands clean can significantly reduce ascaris infection rate.

Ascariasis↗
PubMed1996

Effect of removing Ascaris on the growth of Guatemalan schoolchildren.

OBJECTIVE: To determine whether successful deworming for 6 months in children with high levels of Ascaris improves physical growth. SUBJECTS: Two hundred twenty-eight children (mean age, 9.7 years) in a highland Indian town in Guatemala. DESIGN: Children were randomly assigned to receive albendazole or placebo at baseline and 12 weeks. Children and field workers were both blind to the group assignment. OUTCOME MEASURES: Children's heights, weights, and mid-upper-arm circumferences were measured at baseline and 12 and 24 weeks. Fecal egg counts were taken at 0, 2, 12, 14, and 24 weeks to estimate the helminth burden (eggs per gram of feces [epg]). RESULTS: Baseline helminth prevalences were Ascaris, 91%, and Trichuris, 82%. Ascaris intensities were high: half of the children had moderate burdens (10 000 to 50 000 epg), and 25% had heavy burdens ( > 50 000 epg). Trichuris burdens were light (72% < 1000 epg). The albendazole and placebo groups did not differ at baseline in epg, age, anthropometry, or socioeconomic status. The two rounds of treatment successfully reduced the Ascaris burdens but had less effect on Trichuris. At 6 months the treatment group showed a small gain in weight (0.18 kg) compared with the placebo group but no improvement in height or mid-upper-arm circumference. CONCLUSIONS: The successful removal of ascaris in a population of school-aged children with relatively high loads may have modest effects on weight gain. Ascaris is one of the most common infections in school-aged children, but its effect on the host may be less than that of other helminths.

Albendazole↗
PubMed1961

Antigenic properties of purified fractions from Ascaris lumbricoides var. Suum on naturally sensitized guinea-pig.

Purified extract of Ascaris injected intravenously into guinea-pigs produced a reaction very similar to the anaphylactic reaction. As shown by the ratio of deaths to survivals the toxic fraction contained in Ascaris extract was purified 3 to 4 times. After intravenous injection animals presented both anaphylaxis-like shock and mast cell damage similar to that observed in anaphylaxis. Perfusion of the lungs with Ascaris fractions released histamine. Isolated guinea-pig ileum when in contact with Ascaris fractions showed a response followed by desensitization. Heating the ileum to 45 degrees C or previous desensitization to anaphylatoxin excluded the participation of the latter in this contraction. In vitro, sensitization from one guinea-pig could be transferred to another, using spleen extract or a 50% ammonium sulphate precipitate obtained from the spleen extract. On the basis of these results it is concluded that guinea-pigs are naturally sensitized to antigen or antigens present in Ascaris lumbricoides.

Anaphylaxis↗
PubMed1995

[Interstitial nephritis with acute renal failure in Ascaris lumbricoides infection].

A girl aged 14 years, 8 months presented with painful swelling of cervical lymph nodes. On frozen section malignancy could be ruled out. There were nonspecific inflammatory changes. In the presence of a prominent eosinophilic reaction the possibility of a drug reaction had been suggested. Because of decreasing renal function, dialysis was started 1 day after lymph node extirpation. A renal biopsy revealed acute interstitial nephritis-again with eosinophils. At this point parasitosis was discussed. There was a slightly elevated titer for filariasis. Shortly thereafter, also eggs of Ascaris lumbricoides were found in the feces. A pulmonary infiltrate made its appearance, with eosinophils in the pleural fluid. About 20 days later, after dialysis and anti-Ascaris therapy, the patient was discharged with no further complaints. Repeated controls revealed no further complaints, especially no more Ascaris lumbricoides. This case had two special aspects: (1) initial presentation with painful cervical lymph node swelling, and (2) subsequent acute renal failure. The literature revealed only four patients with Ascaris lumbricoides infection and acute interstitial nephritis, all described by one author (Zollinger). Perhaps a special hyperergic situation in this patient was responsible for the renal involvement; however, this complication should be watched for in all cases Ascaris lumbricoides infections.

Acute Kidney Injury↗
PubMed1980

Control of pyrimidine biosynthesis in the Ascaris ovary: regulatory properties of glutamine-dependent carbamoyl-phosphate synthetase and copurification of the enzyme with aspartate carbamoyltransferase and dihydroorotase.

Glutamine-dependent carbamoyl-phosphate synthetase, the first enzyme of the de novo biosynthetic pathway for pyrimidine nucleotides, was purified about twenty-fold from 105 000 x g supernatant of the Ascaris ovary homogenate. The enzyme activity was feedback-inhibited by UDP and UTP while it was stimulated by 5-phosphoribosyl 1-pyrophosphate. Most of the catalytic and regulatory properties of the Ascaris synthetase were similar to those of the mammalian synthetase. A significant difference is that the Ascaris enzyme was more strongly inhibited by UDP than by UTP whereas the mammalian enzyme is more sensitive to UTP than to UDP. The Ascaris enzyme was also inhibited by other various nucleoside diphosphates, such as dUDP, dADP and CDP, generally more strongly than by the corresponding nucleoside triphosphates. Aspartate carbamoyltransferase and dihydroorotase, the second and third enzymes of the pathway, were also demonstrated in the supernatant fraction. These two enzymes were copurified with the synthetase and the relative activities of the three enzymes remained nearly constant (1:850-890:50-60) throughout the purification. In a sucrose gradient centrifugation, the enzymes cosedimented as a single peak with a sedimentation coefficient (s20,w) of about 32 S under the condition used. These results strongly suggest that the enzymes exist as a multienzyme complex similar to those found in higher animals. The activity of the carbamoyltransferase was insensitive to nucleotides and related compounds. These results indicate that the synthetase plays a key role in the control of pyrimidine biosynthesis in the Ascaris ovary.

Amidohydrolases↗
PubMedDate not supplied

Liming as an advanced treatment for sludge sanitisation: helminth eggs elimination--Ascaris eggs as model.

The presence of helminth eggs (Ascaris eggs) in sewage sludge may constitute a sanitary risk when used as agricultural fertiliser. Sanitisation of sewage sludge can be achieved by treatment with quick lime, a process that destroys sludge pathogens in two ways: pH increase and temperature rise. Among the pathogens of epidemiological relevance, Ascaris eggs are the most resistant to liming, and, hence, may serve as indicators of hygienic quality of biosolids. This research aims at defining, between 50 degrees C and 60 degrees C, the time required in the case of limed sludge to obtain a product with a negligible level of viable Ascaris eggs. To achieve this objective, investigations on inactivation kinetics of Ascaris eggs were conducted in the following products: contaminated milk of lime; naturally contaminated sludge treated with slaked lime and heat; naturally contaminated sludge treated with quick lime; and sludge treated at full scale with quick lime. For the inactivation kinetics where a negligible level of Ascaris eggs was reached, the inactivation threshold was determined. Depending on the experimental situation, the inactivation threshold period was found to fluctuate between 5 and 75 min at 55 degrees C and between 1 and 8 min at 60 degrees C.

Animals↗
PubMed1999

Characterisation of Ascaris from human and pig hosts by nuclear ribosomal DNA sequences.

The sequences of the nuclear ribosomal DNA region spanning the first internal transcribed spacer, the 5.8S rRNA gene and the second internal transcribed spacer were determined for Ascaris samples from pigs and humans from different geographical regions. The sequences of the 5.8S gene and the second internal transcribed spacer were the same for all samples examined, whereas all Ascaris samples from humans had six (1.3%) nucleotide differences in the first internal transcribed spacer compared with those from pigs. These differences provided some support for the existence of separate species of Ascaris or population variation within this genus. Using a nucleotide difference within a site for the restriction enzyme HaeIII, a PCR-linked restriction fragment length polymorphism method was established which allowed the delineation of the Ascaris samples from pigs and humans used herein. Exploiting the sequence differences in the first internal transcribed spacer, a PCR-based single-strand conformation polymorphism method was established for future analysis of the genetic structure of pig and human Ascaris populations in sympatric and allopatric zones.

Animals↗
PubMed1998

Ascaris-specific IgE and allergic sensitization in a cohort of school children in the former East Germany.

BACKGROUND: Helminthic infections induce an IL-4-dependent polyclonal stimulation of IgE synthetization. It is still unclear, however, what role helminths play in allergic sensitization. OBJECTIVE: We sought to determine the relationship between Ascaris-specific IgE and allergic sensitization in a nontropical country. METHODS: In 2 consecutive cross-sectional surveys in 1992-1993 and 1995-1996, data from school entrants (age range, 5 to 7 years), third graders (age range, 8 to 10 years), and sixth graders (age range, 11 to 14 years) were collected. The 2 younger groups were reexamined in the second survey. Data for about 2300 children, including a cohort of 700 subjects, were analyzed. Ascaris IgE and total and specific IgE to inhalant allergens were measured, and skin prick tests were performed. Information about asthma and allergic rhinitis was collected by a questionnaire. RESULTS: Children who were Ascaris-IgE seropositive (>0.35 IU/mL) in both surveys had 10-fold higher levels of total IgE (451 IU/mL vs 45 IU/mL, P < .001) and higher prevalence rates of allergen-specific IgE seropositivity (56.3% vs 26.6%, P < .001). They also had a higher prevalence of allergic rhinitis (12.6% vs 3.7%, P < .001) and asthma (5.7% vs 1.6%, P < .05). In subjects who were Ascaris-seronegative in the first survey but seropositive in the second survey, total and specific IgE increased markedly. Sensitization to Dermatophagoides pteronyssinus increased nearly 3-fold in this group. In contrast, in children who became Ascaris-seronegative, total and specific IgE decreased. CONCLUSIONS: Contact with low doses of helminthic antigen is associated with an increase of total and specific IgE production. Helminthic infections in East German children are not the cause for a low prevalence of allergies in the former East Germany.

Adolescent↗
PubMed2006

Skin test reactivity and Der p-induced interleukin 10 production in patients with asthma or rhinitis infected with Ascaris.

BACKGROUND: Helminth infections have been associated with reduced reactivity to aeroallergens, which could be related to interleukin 10 (IL-10) production, as reported in schistosomiasis. OBJECTIVE: To compare skin responses to aeroallergens with Der p specific IL-10 production in patients with asthma or rhinitis according to Ascaris infection status. METHODS: Cross-sectional study of 113 patients with asthma or rhinitis from a region endemic for geohelminths. Stool examinations and skin prick tests to aeroallergens were performed in all the patients. Der p specific IL-10 production was measured in the supernatant of peripheral blood mononuclear cell (PBMC) cultures of a subsample of 53 patients. RESULTS: Forty-seven patients had Ascaris in their stool samples. Skin test results were positive in 77% of Ascaris-infected patients and in 71% of uninfected individuals. Median levels of Der p specific IL- 10 in PBMC cultures of infected and uninfected patients were similar (7.8 and 8.4 pg/mL, respectively). The lack of association remained when parasite load was taken into account and when patients with evidence of previous infection were removed from the uninfected group. CONCLUSIONS: In patients with asthma or rhinitis living in an urban area endemic for geohelminths, we found no association between Ascaris infection and skin reactivity to aeroallergens. Furthermore, there was no difference in Der p specific IL-10 production by PBMCs. These negative findings indicate that different from what is observed in Schistosoma infection, Ascaris lumbricoides infection in individuals living in an urban area does not induce strong regulatory responses.

Adolescent↗
PubMed1989

Synergistic effect of migrating Ascaris larvae and Escherichia coli in piglets.

The effect of intestinal flora on the establishment, development and pathogenicity of Ascaris suum larvae in piglets (Large White breed) was investigated. The infected piglets with Ascaris and Escherichia coli showed signs of pneumonia, cough with respiratory difficulties initially even though these moderated with time. They lost appetite and showed signs of unthriftiness with loss of weight. The packed cell volume was normal but the differential leucocyte counts of the pigs infected with Ascaris larvae and bacteria had high neutrophils, unlike the very high lymphocyte count observed in piglets with ascarids only. The piglets had generalized serous atrophy of body fat. The pericardial and perirenal fats were gelatinous. There was a firm and nodular grey and red hepatization with abscess pockets in the intermediate and anterior one third of the diaphragmatic lobes of the lungs. The liver contained greyish-white and depressed focus immediately dorsal to the area of attachment to the gall bladder with multifocal areas. There was no significant gross lesion in the control animals. Cultural and microscopic examinations of some internal organs of the infected animals showed that bacteria were carried to the lungs by the migrating Ascaris larvae. The combined synergistic effect of Ascaris larvae and E. coli was also investigated and it was concluded that the two agents (A. suum larvae and E. coli) worked together synergistically.

Animals↗