Somatic antigen of Ascaris lumbricoides was purified to homogeneity (molecular mass, 34 kDa) by ammonium sulfate fractionation and successive chromatographic procedures, namely, gel permeation, ion exchange, and high-performance gel permeation liquid chromatographies. The antigen showed strong binding with immunoglobulin G (IgG) in Ascaris-infested patients and was cross-reactive with IgE and IgG in patients infested with other nematodes. It reacted specifically with IgG4 (P < 0.001) in 63 Ascaris-infested patients, which represented 65% of the total IgG response, though cross-reactivity with IgG1, IgG2, and IgG3 subclasses was observed, indicating the unique specificity of this test system and its potential utility in the serodiagnosis of ascariasis.Ascaris lumbricoides infects about one-fourth of the world's population (21) and is considered to be one of the causes of various other ailments, namely, intestinal obstruction, acute pancreatitis, acute appendicitis (12), and malnutrition in children (9). Despite the high prevalence of Ascaris infection, no good method for diagnosing ascariasis in the context of an epidemiological investigation has yet been devised except for parasitological screening for the presence of eggs in stool. However, this method poses logistical and social problems. The use of an alternative method, such as serodiagnosis, is limited by the extensive cross-reactivity between the antigenic epitopes of different nematodes infective to humans. Ascariasis is associated with elevated immunoglobulin E (IgE) and IgG responses in humans and animals (11,24). Serological tests based on IgG detection may overestimate the prevalence of infection, due to the persistence of antibodies for a long time after the deworming of patients. Although a novel, specific, and sensitive technique for the serodiagnosis of ascariasis that involves the assessment of Ascaris excretory-secretory (ES) antigen-specific IgG4 has been developed (3), procurement of ES antigen from living worms is limited due to the small number and death of the worms after deworming.As a substance released from living worms, ES antigen possesses a significant antibody response; however, the source of the ES antigen is unknown. The possibility of its derivation from the worm's somatic cell component could not be ruled out. If ES antigen responsible for the IgG4 response in the infected host persists in the worm's somatic cell component(s), this could be a chief alternative source of IgG4-specific antigen for the diagnosis of ascariasis, due to its easy availability from the whole worm rather than from the ES antigen.The present study describes the purification of the A. lumbricoides somatic antigen and its reactivity with serum IgE and IgG, especially with subclasses of IgG by enzyme-linked immunosorbent assay (ELISA), which may be useful markers for diagnosis of Ascaris infection in an epidemiological study.Sixty-three patients (29 males and 34 females, 8 to 65 years of age) from urban and rural areas of West Bengal, India, infested with Asc...

Epithelial cells in vivo exist as confluent cell sheets, but this confluence is disrupted if the sheets are wounded, if the cells are undergoing morphogenesis, or if they are taking part in invasion and metastasis. Desmosomes are one of the principal types of adhesive junctions in epithelia and are responsible for maintaining tissue integrity. It is likely that modulation of desmosomal adhesion is required to facilitate cell motility in response to alterations in the tissue architecture. Desmosomal adhesion changes from a calcium-dependent state to a calcium-independent state when cells become confluent. Our laboratory has shown that the alpha isoform of protein kinase C is involved in signaling the response of desmosomes to calcium concentration and wounding, in cultured epithelial cells and in mouse epidermis (in vivo).

The immunodominant part in the O-antigenic polysaccharide from Escherichia coli O128 was immunologically characterized by an enzyme-linked immunosorbent assay (ELISA). The antibody specificity was determined by the inhibitory effects of the methyl glycosides of constituent mono- and oligosaccharides synthesized related to the O-antigenic polysaccharide from E. coli O128. It was found that methyl alpha-L-fucopyranoside was the most effective inhibitor amongst the monosaccharides while the highest antibody specificity was directed towards the trisaccharide with the structure: beta-D-GalpNAc-(1-->6)-[alpha-L-Fucp-(1-->2)]-beta-D-Galp-1-->OMe suggesting that the monospecific antibody has the extended combining site.

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