Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ASCARIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2006

Respiratory atopic disease, Ascaris-immunoglobulin E and tuberculin testing in urban South African children.

BACKGROUND: Epidemiological relation of intestinal helminth infection and atopic disease, both associated with a T-helper (Th) 2 immune response, is controversial, as it has been reported that helminth infection may either suppress or pre-dispose to atopic disease. This relation has not been tested in an area with a high burden of Mycobacterium tuberculosis (MTB) infection, a known Th1-stimulating infection. OBJECTIVE: To study the association of intestinal helminth infection and atopic disease in a community where helminth infection is endemic and MTB infection is high. METHODS: Three-hundred and fifty-nine randomly selected children aged 6-14 years from a poor urban suburb were tested with allergy questionnaire, skin prick test (SPT) to common aeroallergens, Ascaris-specific IgE (Ascaris-sIgE), fecal examination for pathogenic intestinal helminths and tuberculin skin testing (TST). Histamine bronchoprovocation was tested in the group of children aged 10 years and older. RESULTS: were corrected for demographic variables, socioeconomic status, parental allergy, environmental tobacco smoke (ETS) exposure in the household, recent anthelminthic treatment and for clustering in the sampling unit. Results Ascaris-sIgE was elevated in 48% of children, Ascaris eggs were found in 15% and TST was positive in 53%. Children with elevated Ascaris-sIgE had significantly increased risk of positive SPT to aeroallergens, particularly house dust mite, atopic asthma (ever and recent), atopic rhinitis (ever and recent) and increased atopy-related bronchial hyper-responsiveness. In children with negative TST (<10 mm), elevated Ascaris-sIgE was associated with significantly increased risk of atopic symptoms (adjusted odds ratio (OR(adj)) 6.5; 95% confidence interval (CI) 1.9-22.4), whereas in those with positive TST (>/=10 mm) this association disappeared (OR(adj) 0.96; 95% CI 0.4-2.8). CONCLUSIONS: These results suggest that immune response to Ascaris (Ascaris-sIgE) may be a risk factor of atopic disease in populations exposed to mild Ascaris infection and that MTB infection may be protective against this risk, probably by stimulation of anti-inflammatory networks.

Adolescent↗
PubMed1986

Purification of Ascaris suum antigen: its allergenic activity in vitro and in vivo.

Crude aqueous extracts of Ascaris suum (CE) have been used widely to study IgE-mediated reactions in various experimental preparations. Because some CE may contain a polypeptide, a mast cell degranulating peptide (MCDP), that degranulates mast cells by nonimmunologic mechanisms, various protocols have been used to ensure that the Ascaris preparation used did not contain MCPD. In general, these protocols have assumed MCDP had been without providing proof. Even protocols designed to isolate the major antigenic determinants from CE have usually been designed to evaluate immunogenic characteristics of the purified Ascaris; thus, few systematic comparisons of CE with purified Ascaris exist concerning mast cell degranulation, and few studies have demonstrated that MCDP has been removed during purification. Since Ascaris has proved to be useful in a variety of studies of IgE-mediated reactions, particularly in large animals (dog and sheep), we have developed a protocol to purify CE and MCDP and characterize their physiochemical and immunologic properties. We compared the allergenic activity of our purified Ascaris to that of CE and MCDP in skin and lung of natively sensitized dogs and in unsensitized rat peritoneal mast cells. Our results indicate that MCDP probably contaminates CE by less than 1.0%. However, the biologic activity of MCDP in dog lung appears insignificant and probably contributes little to CE-induced reactions in doses of CE commonly used (less than or equal to 100 mg injected). If a purified Ascaris preparation is essential, our protocol will yield an Ascaris preparation that has potent IgE-mediated effects in dog preparations with insignificant contamination by MCDP.

Allergens↗
PubMedDate not supplied

Relationship between specific serum IgE to Ascaris lumbricoides and onset of respiratory symptoms in Bangladesh immigrants.

The role of helminths in asthma and/or rhinitis and in allergic sensitization is still unclear. We assessed the relationship between Ascaris-specific IgE, respiratory symptoms and allergic sensitization in Bangladesh immigrants. 246 individuals were examined from 1996 to 2001. Serum total IgE, Ascaris IgE, specific IgE to inhalant allergens, skin prick tests (SPT) and parasitological evaluation of the stool were performed. Total serum IgE were significantly higher in Ascaris-IgE positive (> 0.35 kU/L) individuals (806.5 [409.0-1436.0] kU/L vs. 207.0 [127.0-332.5] kU/L; P < 0.0001) and in subjects with respiratory symptoms (413.0 [239.0-1096.0] kU/L vs. 259.5 [147.0-387.0] kU/L), (P < 0.0001), but not in SPT positive subjects (413.0 [179.0-894.0] kU/L vs. 404.6 [305.0-1201.0] kU/L (P = 0.5). Ascaris-specific IgE were detected in 48 subjects with respiratory symptoms (40.0%) and in 46 subjects without respiratory symptoms (36.5%) (P = 0.5). The SPT positivity was similar between Ascaris-IgE seropositive (38.2%) and Ascaris-IgE seronegative (38.1%) subjects (P = 0.9). Total IgE and length of stay in Italy correlated with SPT positivity (OR 5.6 [CI 95% 1.5-19.8], P = 0.007, and OR 1.5 [CI 95% 1.3-1.7], P< 0.0001), and with respiratory symptoms (OR 13.7 [CI 95% 3.0-62.4];, P = 0.0007, and OR 2.4 [CI 95% 1.9-3.0], P < 0.0001). Ascaris-IgE were negatively associated with SPT positivity (OR 0.3 [CI 95% 0.1-0.8], P = 0.02) and with respiratory symptoms (OR 0.1 [CI 95% 0.04-0.7], P = 0.01). Our findings favour the role of environmental factors in the development of respiratory symptoms in immigrants, irrespective of Ascaris-IgE.

Adult↗
PubMed1988

Role of cyclooxygenase products of arachidonic acid metabolism in Ascaris antigen-induced bronchoconstriction in sensitized dogs.

The pharmacologic modulation of Ascaris allergen-induced bronchoconstriction was investigated in beagle dogs sensitized by experimental infection with Ascaris suum ova. Ascaris-induced increases in total lung resistance (RL) and falls in dynamic lung compliance (Cdyn) were unaffected by pretreatment with an antihistamine (pyrilamine) given alone but were significantly attenuated (P less than .05) by the cyclooxygenase enzyme inhibitor, indomethacin. The combination of pyrilamine and indomethacin also produced a significant (P less than .01) inhibition of Ascaris-induced bronchoconstriction, greater than that produced by indomethacin given alone but the difference between the two treatment groups was not statistically significant. The combination of an antihistamine, the cyclooxygenase inhibitor indomethacin and the leukotriene synthesis inhibitor, U-60,257, almost completely abolished Ascaris-induced bronchoconstriction (91% inhibition of Cdyn changes; 93% inhibition of RL changes). The inhibition was significantly greater than that produced by cyclooxygenase inhibition alone. The leukotriene synthesis inhibitor piriprost (U-60,257) given alone or in combination with pyrilamine produced no inhibition of Ascaris-induced changes in RL or Cdyn. The leukotriene antagonist FPL55712 or the thromboxane synthase inhibitor U-63,557A also showed little or no activity in this model, whereas the thromboxane receptor antagonist AH23848 produced a marked inhibition of Ascaris-induced bronchoconstriction. We conclude that Ascaris-induced bronchoconstriction is mediated primarily by cyclooxygenase products of arachidonic acid metabolism. The role of histamine and lipoxygenase products can only be revealed during an effective cyclooxygenase blockade.

Animals↗
PubMed1980

[The specificity of pharmacological responses in Ascaris muscle (author's transl)].

To investigate the pharmacological properties of Ascaris muscle, comparative studies were undertaken on the actions of various drugs on Ascaris muscle, guinea pig isolated ileum and frog isolated rectus preparations. In Ascaris muscle and frog isolated rectus preparations, the contractile activities with acetylcholine (ACh, 10(-5) g/ml in Ascaris and 10(-6) g/ml in frog rectus) and 1, 1-dimethyl-4-phenylpiperazinium (DMPP, 10(-6) g/ml) were inhibited significantly and reversely by d-tubocurarine (d-Tc, 10(-5) g/ml) and mecamylamine (Meca, 10(-5) g/ml), and slightly by atropine (Atr, 10(-4) g/ml) and hexamethonium (C6, 10(-4) g/ml). In guinea pig isolated ileum preparation, the contractile activity with ACh (10(-6) g/ml) was inhibited markedly and reversely but Atr (10(-6) g/ml), while the activity with DMPP (10(-6) g/ml) was similarly inhibited by Meca (10(-6) g/ml), C6 (10(-6) g/ml) and Atr (10(-6) g/ml). Although frog isolated rectus preparation was contracted with 4-(m-chlorophenylcarbamoyloxy)-2-butynyltrimethylammonium (McN-A-343, 10(-5) g/ml) but not with pilocarpine (10(-4) g/ml), Ascaris muscle preparation was not affected by these agonists. Frog isolated rectus preparation was contracted with 5-hydroxytryptamine (5 HT, 10(-4) g/ml) but was not affected by histamine (His, 10(-3) g/ml) and gamma-aminobutyric acid (GABA, 10(-4) g/ml), whereas Ascaris muscle was contracted with His (10(-3) g/ml) and relaxed with 5-HT (10(-4) g/ml) and GABA (10(-5) g/ml). These results suggest that Ascaris muscle as well as skeletal muscle have nicotinic receptors and that the Ascaris muscle has properties which differ specifically from skeletal muscle.

Acetylcholine↗
PubMed1979

[Seasonal Fluctuation Of Ascaris Reinfection Incidences In A Rural Korean Population]

This study was undertaken to estimate the reinfection incidence of Ascaris lumbricoides after biannual blanket mass chemotherapy and to figure out the characteristic seasonal fluctuation pattern in a Korean rural village. A total of 612 residents from 4 Ri's of Hwasung Gun, Kyunggi Do, Korea was selected and divided into 6 groups according to hamlets, each of which consisted of about 100 inhabitants. Each group received blanket biannual mass chemotherapy with 10 mg/kg of pyrantel pamoate respectively in each month, during the period from April 1977 to September 1978(Group A-April and October 1977 and April 1978, Group B-May and November 1977 and May l978, and so on). 1. Beforehand Ascaris infection status was evaluated by examining eggs and worms expelled exactly after the first mass chemotherapy checked during the first 6 months and the reinfection incidences were estimated in follow-up examinations during next l2 months by the above two kinds of methods and by detection of young Ascaris positive cases. Young Ascaris was defined as worm shorter than l3 cm and lighter than 500 mg and considered to have introduced to human host during the period from the previous 2 months to 2 weeks. The results were summarized as follows: 1.Beforehand infection rate with Ascaris were 42.3% (34.4~50.6% by group) by egg detection and 46.2% (36.2~51.9% by group) by worm detection methods in average. Number of worms per infected case was 2.7 (1.5~4.2 by group) in average. 2. Reinfection rates estimated by egg detection ranged from 8.0 to 3l.5% (l6.9% in average) in the first follow-up period and from 14.0 to 20.0% (l7.5% in average) in the second follow-up. Seasonal fluctuation was found marked and there were roughly two peaks, of which the larger appeared from February to March and the smaller from August to September. 3. Reinfection rates by worm detection method ranged from 20.6 to 34.9%(25.7% in average) and from 14.3 to 21.9% (19.6% in average) in respective follow-up examinations. Seasonal fluctuation was also observed and the peak incidence appeared one month earlier than those made by egg positive conversion. Number of worms per infected case decreased to 1.6 in average in both follow-up. 4. Young Ascaris detection rates ranged from 6.0 to 12.9% (9.4% in average) and from 2.3 to 5.8% (3.8% in average) in respective follow-up. Seasonal fluctuation was also observed. From January to February, the positive rates were up to 12.9% and 12.7% respectively, which formed the higher peak. Lower one was observed during July to August. From the above results, the actual time of Ascaris reinfection were November to December for the higher peak and May to June for the lower one in Korean population. Pickled vegetable was suggested as a most probable source of Ascaris reinfection during late autumn to winter season.

Journal Article↗
PubMed1975

Studies on the subunits of myosin from muscle layer of Ascaris lumbricoides suum.

1. A purified preparation of Ascaris myosin was obtained from the muscle layer of Ascaris lumbricoides suum, using gel filtration and ion-exchange chromatography. 2. Ascaris myosin whether purified or unpurified, had almost the same ability for ATP-splitting and superprecipitation. 3. Ascaris myosin and rabbit skeletal myosin were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A significant difference in the number of light chains between both myosins was found. Ascaris myosin was found to have one heavy chain and two distinct light chain components (LC1-A and LC2-A), having molecular weights of 18000 and 16000, respectively. These light chains correspond in molecular weight to the light chain 2 (LC2-S) and light chain 3 (LC3-S) in rabbit skeletal myosin. 4. LC1-A could be liberated from the Ascaris myosin molecule reacted with 5,5'-dithio-bis(2-nirobenzoic acid( Nbs2) with recovery of ATPase activity by addition of dithiothreitol. These properties are equivalent to those of the LC2-S in rabbit skeletal myosin, although Ascaris myosin when treated with Nbs2-urea lost its ATPase activity.

Adenosine Triphosphatases↗
PubMed1995

The effect of the nematode peptides SDPNFLRFamide (PF1) and SADPNFLRFamide (PF2) on synaptic transmission in the parasitic nematode Ascaris suum.

The action of two peptides isolated from the nematode Panagrellus redivivus, PF1 (SDPNFLRFamide) and PF2 (SADPNFLRFamide) have been studied on synaptic transmission in the motornervous system of the parasitic nematode Ascaris suum. Intracellular recordings were made from Ascaris somatic muscle cells and excitatory junction potentials (EJPs) elicited by stimulation of the ventral nerve cord. The EJPs were cholinergic as they were blocked by the Ascaris nicotinic receptor antagonist, benzoquinonium. PF1 caused a slow hyperpolarization, similar to the action of this peptide first reported by Bowman, Geary & Thompson (1990) and further characterized by Franks et al. (1994). The hyperpolarization was accompanied by a marked decrease in the amplitude of the EJPs with an EC50 of 311 +/- 30 nM (n = 5). This inhibition is unlikely to be due to a post-synaptic site of action of the peptide as the muscle cell input conductance was not significantly altered by PF1 and furthermore the response to bath-applied acetylcholine was not inhibited by PF1 at concentrations up to 10 microM (n = 6). PF2 also inhibited the EJPs in a similar manner to PF1. These studies indicate that both of the peptides isolated from the free-living nematode Panagrellus redivivus have biological activity in the parasitic nematode Ascaris suum. PF1 and PF2 have inhibitory actions in contrast to the predominantly excitatory actions of the Ascaris endogenous peptides AF1 (KNEFIRFamide) and AF2 (KHEYLRFamide). The potent actions of the Panagrellus neuropeptides PF1 and PF2 in Ascaris suggest that peptides with a similar or identical sequence may also occur in Ascaris and have an inhibitory role in the motornervous system.

Acetylcholine↗
PubMed1993

Genetic structure and epidemiology of Ascaris populations: patterns of host affiliation in Guatemala.

In Guatemalan villages people commonly rear pigs, and both hosts may be infected with Ascaris. This study was designed to ask whether both humans and pigs are potential hosts in a single parasite transmission cycle in such villages, or alternatively, if there are two separate transmission cycles, one involving pigs and one involving human hosts. Parasites were collected from both host species from locations in the north and south of Guatemala. Allelic variation in the nuclear genome of Ascaris was measured using enzyme electrophoresis, while mitochondrial DNA (mtDNA) sequence variation was quantified using restriction mapping. Low levels of enzyme polymorphism were found in Ascaris, but allele frequencies at two loci, mannose phosphate isomerase and esterase, suggest that there is little gene exchange between parasite populations from humans and pigs. MtDNA haplotypes fall into two distinct clusters which differ in sequence by 3-4%; the two clusters broadly correspond to worms collected from humans and those collected from pigs. However, some parasites collected from humans have mtDNA characteristic of the 'pig Ascaris' haplotype cluster, while some parasites collected from pigs have mtDNA characteristic of the 'human Ascaris' haplotype cluster. These shared haplotypes are unlikely to represent contemporary cross-infection events. Patterns of phylogenetic similarity and geographical distribution of these haplotypes suggest, instead, that they are the result of two historical introgressions of mtDNA between the two host-associated Ascaris populations. The results clearly demonstrate that Ascaris from humans and pigs are involved in separate transmission cycles in Guatemala.

Alleles↗
PubMed1980

Homology between roundworm (Ascaris) and hookworm (N. americanus) antigens detected by human IgE antibodies.

Utilizing the techniques of radioallergosorbent test (RAST), inhibition of RAST and isoelectric focusing on polyacrylamide gels, antigenic cross-reactivity has been shown between extracts of Ascaris lumbricoides. Ascaris suum and Necator americanus (hookworm). Antigenic homology is extensive between the two Ascaris preparations. The antigens common to hookworm and Ascaris, while representing a minor component of Ascaris body fluid, are nonetheless potent stimulators of IgE antibody production in subjects infected only with hookworm larvae. These shared antigens appear to have a pI of less than 5.1. The hookworm specific antigens also have a pI of less than 5.1, whereas those specific to Ascaris have pI values in the ranges of 5.0 to 6.0 and 7.0 to 8.6. These latter antigens, i.e. those with pI between 7.0 and 8.6, apparently elicit an immune response only during an active infection with Ascaris.

Antigens↗
PubMedDate not supplied

Cellular responses and cytokine profiles in Ascaris lumbricoides and Trichuris trichiura infected patients.

The impact of intestinal helminth infection, i.e. Ascaris lumbricoides and Trichuris trichiura, on cellular responsiveness and cytokine production was investigated in young adults. Ascaris-specific cellular responsiveness was higher in parasite-free endemic controls than in patients infected with T. trichiura, or A. lumbricoides, or patients co-infected with both parasites. Also, mitogen-induced tumour necrosis factor (TNF)-alpha, interleukin (IL)-12 and interferon (IFN)-gamma secretion by peripheral blood mononuclear cells (PBMC) was higher in negative endemic controls than in infected individuals. Ascaris antigen-specific production of TNF-alpha, IL-12 and IFN-gamma was low in singly Ascaris as well as in co-infected patients, whereas secretion of IL-10 and IL-13 was elevated and similarly high in all patient groups. The detection of Trichuris-specific and Ascaris-specific IgG4 revealed significantly higher serum antibody levels in Trichuris or Ascaris patients when compared to endemic controls (P < 0.05), whereas parasite-specific IgE antibody levels were similarly high in infected individuals and in endemic controls. In summary, chronically infected Ascaris and Trichuris patients with a high parasite load presented reduced cellular reactivity and lower type 1 TNF-alpha, IFN-gamma and IL-12 responses when compared with endemic controls, whereas type 2 IL-10 and IL-13 productions were similar in all groups from the endemic area. The former may support parasite persistence, whereas substantial type 2 cytokine release may promote protective immunity, suggesting an adaptation of the host to control the parasite burden while minimizing immune-mediated host self-damage.

Adult↗
PubMed2003

Distal heme pocket conformers of carbonmonoxy derivatives of Ascaris hemoglobin: evidence of conformational trapping in porous sol-gel matrices.

We report the ligand dependence of the conformer distribution in the distal heme pocket of Ascaris suum hemoglobin (Hb) studied by resonance Raman spectroscopy. The heme-bound CO is used as a spectroscopic antenna to probe the original distribution of conformers in the dioxygen derivative of Ascaris Hb, by utilizing sol-gel encapsulation. The first step is to encapsulate the dioxygen derivative in the porous sol-gel and let the gel age, thus trapping the equilibrium conformational distribution of Ascaris dioxygen Hb. In the second step, the dioxygen ligand is replaced by CO. The sol-gel environment impedes any large scale movements, drastically slowing down the conformational relaxation triggered by the ligation change, essentially "locking in" the initial quaternary and even tertiary structure of the protein. Studying the Fe-CO frequencies of the latter sample allows evaluation of the distribution of the distal heme pocket conformers that was originally associated with the dioxygen derivative. Extending the study to the Ascaris mutants allows for examination of the effect of specific residues in the distal pocket on the conformational distribution. The choice of mutants was largely based on the anticipated variation in hydrogen bonding patterns. The results show that the sol-gel encapsulation can slow or prevent re-equilibration within the distal heme pocket of Ascaris Hb and that the distribution of distal heme pocket conformers for the CO derivative of Ascaris Hb in the sol-gel is highly dependent on the history of the sample. Additionally, we report a detailed study of the CO complex of the mutants in solution for assignment of the various heme pocket conformers, and we present a comparison of the sol-gel data with solution data. The results support a picture in which the dioxygen derivative biases the population strongly toward a tightly packed configuration that favors the network of strong hydrogen bonding interactions, and suggest that Ascaris Hb is uniquely designed for dioxygen capture.

Animals↗
PubMed1989

GABA receptors on the somatic muscle cells of the parasitic nematode, Ascaris suum: stereoselectivity indicates similarity to a GABAA-type agonist recognition site.

1. The gamma-aminobutyric acid (GABA) receptors on the somatic muscle cells of Ascaris, which mediate muscle cell hyperpolarization and relaxation, have been characterized by use of intracellular recording techniques. 2. These receptors are like mammalian GABAA-receptors in that the response is mediated by an increase conductance to chloride ions. The GABAA-mimetic, muscimol, has a relative potency of 0.40 +/- 0.02 (n = 3) compared to GABA. 3. The stereoselectivity of the GABA receptor on Ascaris is identical to that for the mammalian GABAA-receptor, as determined from the relative potency of three pairs of enantiomers of structural analogues of GABA. 4. The most potent agonist is (S)-(+)-dihydromuscimol which is 7.53 +/- 0.98 (n = 5) times more potent than GABA. 5. The Ascaris GABA receptor is not significantly blocked, at concentrations below 100 microM by the potent, competitive GABAA-receptor antagonist, SR95531. 6. The Ascaris GABA receptor does not recognise agents that are known to block the GABA gated chloride channel in mammalian preparations such as t-butylbicyclophosphorothionate (TBPS, 10 microM, n = 2) or the insecticide dieldrin (100 microM, n = 3). 7. GABAergic responses in Ascaris are not potentiated by pentobarbitone (100 microM, n = 3) or flurazepam (100 microM, n = 3). 8. The potencies of various GABA-mimetics in the Ascaris preparation have been compared with their potency at displacing GABAA-receptor binding in mammalian brain. Excluding the sulphonic acid derivatives of GABA, the correlation coefficient (r) between the potencies of compounds in the two systems is 0.74 (P less than 0.01). The significance of this correlation is discussed. 9. The pharmacology of the Ascaris GABA receptor is discussed in relation to other invertebrate systems and the mammalian subclassification of GABA receptors.

Animals↗
PubMed1976

Effect of ascaris extract applied intravenously, on segment bronchus and the influence of ipsilateral vagus blockade.

Respiratory hypersensitivity and systemic effects after local application of Ascaris suum extract on the segmental bronchus and after its intravenous infusion are studied on four boxer dogs. Influence of ipsilateral vagus blockade on the respiratory hyperreactivity after intrabronchial application of ascaris was also investigated on the same dogs. Ascaris extract was applied in liquid form directly through a catheter into the right segmental bronchus. Egg albumin was applied in the same way for control. Local application of ascaris was repeated after ipsilateral central vagus blockade and once more after recovering vagus effect by lavage. At the end of the experiments ascaris extract was infused intravenously. The parameters studied were: deltaP(oes) mm Hg/100 ml TV (as a measurement of flow resistance in the airways), respiratory rates, arterial blood gases and pH, heart frequency, systemic blood pressure and histamine concentration per milliliter of plasma. All the animals presented a remarkable respiratory distress with local ascaris application, which could be clearly avoided with ipsilateral central vagus blockade. This respiratory hyperreactivity was not observed after intravenous infusion of ascaris extract, but a significant systemic effect, which was not the case after local application, could be observed.

Airway Resistance↗
PubMed1980

Ascaris lumbricoides and the human immunogenic response: enhanced IgE-mediated reactivity to common inhaled allergens.

The relationship between the IgE-mediated immunogenic response to Ascaris and similar responses to common inhaled allergens was determined. Sixty-six of 170 allergic asthmatics from an area in which Ascaris infestation was endemic had positive skin-prick reactions to Ascaris antigen. The number and size of skin-prick reactions to common inhaled allergens were greater in this group than in the 104 Ascaris-negative allergic asthmatics. Specific serum IgE antibodies were determined by the radio-allergosorbent test. The serum IgE levels for Ascaris and three common inhaled allergens correlated well with the skin reactions induced by the same antigens. Total IgE and serum IgE antibody levels for the three inhaled allergens were higher in patients who had positive results on skin testing with Ascaris antigen than in those with negative results. There was no similar association between Dermatophagoides pteronyssinus and six common inhaled allergens. An Ascaris-induced immune response was associated with enhanced IgE-mediated reactivity to common inhaled allergens in both allergic and clinically non-allergic subjects.

Adolescent↗
PubMed1997

The prevalence of Trichuris, Ascaris and hookworm infection in Orang Asli children.

A community study on the age and sex related prevalence, intensity infection and frequency distribution of Ascaris, Trichuris and hookworm was carried out in 205 Orang Asli (Aborigines) children (95 boys, 110 girls) aged 1-13 years. The overall prevalence of Ascaris, Trichuris and hookworm was 62.9%, 91.7% and 28.8%, respectively. Almost two-thirds of the children were infected with moderate and severe intensity infection of Trichuris, 46.3% had moderate to severe intensity infection of Ascaris. However only 1.5% had moderate intensity of hookworm infection. The prevalence and mean intensity infection (measured by eggs per g) of Ascaris was age-dependent; lower in age group 1-4 years reached peak and stable at age group 5 years and above. The prevalence of Trichuris was high in all age groups and it fluctuated with age; the mean intensity of infection of Trichuris (measured by eggs per g) was age-dependent. Hookworm infection also rose with age and reached peak at 5-6 years, following that the prevalence declined. The frequency distributions of Ascaris, and hookworm were overdispersed. A strong positive correlation (p < 0.001) were observed between Ascaris and Trichuris and between hookworm and Trichuris. A positive correlation (p < 0.01) were also observed between Ascaris and hookworm.

Adolescent↗
PubMed1987

The electrophysiology of the somatic muscle cells of Ascaris suum and Ascaridia galli.

The electrophysiological properties of the bag region of the somatic muscle cells of Ascaris suum and Ascaridia galli were studied using intracellular techniques. For Ascaris muscle cells, the mean resting membrane potentials at 20 and 37 degrees C were -29.9 and -33.8 mV respectively, and the average input conductance was 2.12 microS. For the muscle cells of A. galli similar values were obtained. For example, the mean input conductance of these cells was 2.84 microS at 20 degrees C. Healthy Ascaris muscle cells at near physiological temperatures show both spontaneous depolarizing and hyperpolarizing activity and, in cells close to the nerve cords, rhythmic large amplitude (approximately 30 mV) action potentials are observed. Such action potentials, which are very sensitive to temperature variations, originate in the muscle cells. In contrast the muscle cells of Ascaridia are quiescent. The rhythmic action potentials of Ascaris are resistant to tetrodotoxin (TTX) (less than or equal to 10(-6)M), verapamil (10(-4)M) and cinnarizine (10(-4)M), but are blocked irreversibly by 22, 23 dihydroavermectin B1a (10(-7) to 5 X 10(-6) M). GABA, and the GABAA receptor agonists, muscimol and isoguvacine, hyperpolarize and increase the input conductance of both Ascaris and Ascaridia muscle cells. The antagonists + bicuculline and picrotoxin were not effective in modulating the spontaneous hyperpolarizations of Ascaris muscle cells, and picrotoxin (10(-4)M) was not effective in altering the response to GABA (5 X 10(-6)M). The significance of the results is discussed briefly.

Action Potentials↗
PubMed1996

Ascaris, people and pigs in a rural community of Jiangxi Province, China.

A longitudinal investigation on natural populations of Ascaris in humans and pigs and an investigation of soil contamination with Ascaris eggs were carried out from June 1993 to June 1994 in 2 villages, Manhu area, Xinjian County, Jiangxi Province, China. Results from these studies indicate that although human ascariasis is endemic there is significant fluctuation in both prevalence and the mean number of eggs/g faeces (epg) of the communities. Fluctuation of age-stratified prevalence and mean epg was detected in children but not in most adult groups. Most cases of human ascariasis were judged to involve low intensities of infection and a typical overdispersion distribution pattern was observed through the year. It was estimated that during the year, nearly half of the eggs discharged in the environment came from infections in children aged between 2 and 15 years which accounted for about 30% of the total population. Soil in and around houses and in vegetable gardens was found to be contaminated by Ascaris eggs and this situation remained relatively stable throughout the year. Monthly developmental rate of Ascaris eggs in soil was detected and the results suggest that the fluctuation in prevalence observed during the year should be directly attributed to the effect of seasonality of egg development. Features of Ascaris infection in pigs were found to be similar to those in humans except for a lower mean intensity of infection. The possibility of cross-infection of Ascaris between human and pig hosts is discussed.

Adolescent↗