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Mice immunized intragastrically (i.g.) with a genetically constructed chimeric protein consisting of the saliva-binding region (SBR) of Streptococcus mutans AgI/II coupled to cholera toxin (CT) A2 and B subunits (CTA2/B) develop serum immunoglobulin G (IgG) and mucosal IgA antibody responses against AgI/II that are enhanced by the coadministration of CT as an adjuvant. To investigate the development of antigen-specific T cells in the gut-associated lymphoid tissues, mice were immunized i.g. with SBR, SBR-CTA2/B, or SBR-CTA2/B plus CT. AgI/II-specific T cells in Peyer's patches (PP), mesenteric lymph nodes (MLN), and spleen were assayed by lymphoproliferation and flow cytometry for the expression of T-cell surface markers, and cytokine mRNA expression was evaluated by reverse transcription-PCR. T-cell responses were consistent with antibody responses but were detectable after the first immunization. Proliferative responses of PP and MLN cells upon stimulation with AgI/II in vitro were low and delayed in mice given SBR alone, and these cells displayed a mixed type 1 and 2 (or Th0) pattern of cytokine expression. Immunization with SBR-CTA2/B resulted in greater AgI/II-specific proliferative responses in PP cells and an increase in the proportion of CD4+ T cells. Coadministration of CT with SBR-CTA2/B led to greater proliferative responses especially in the MLN cells, which then showed an increase in CD4+ cells. Immunization with SBR-CTA2/B (with or without CT) skewed the cytokine expression pattern in PP and MLN cells toward Th2. The results indicate that T helper cells were induced in gut-associated lymphoid tissues by i.g. immunization with SBR-CTA2/B, concomitantly with and prior to the appearance of circulating and mucosal antibodies.

Mice immunized intragastrically (i.g.) with a genetically constructed chimeric protein consisting of the saliva-binding region (SBR) of Streptococcus mutans AgI/II coupled to cholera toxin (CT) A2 and B subunits (CTA2/B) develop serum immunoglobulin G (IgG) and mucosal IgA antibody responses against AgI/II that are enhanced by the coadministration of CT as an adjuvant. To investigate the development of antigen-specific T cells in the gut-associated lymphoid tissues, mice were immunized i.g. with SBR, SBR-CTA2/B, or SBR-CTA2/B plus CT. AgI/II-specific T cells in Peyer's patches (PP), mesenteric lymph nodes (MLN), and spleen were assayed by lymphoproliferation and flow cytometry for the expression of T-cell surface markers, and cytokine mRNA expression was evaluated by reverse transcription-PCR. T-cell responses were consistent with antibody responses but were detectable after the first immunization. Proliferative responses of PP and MLN cells upon stimulation with AgI/II in vitro were low and delayed in mice given SBR alone, and these cells displayed a mixed type 1 and 2 (or Th0) pattern of cytokine expression. Immunization with SBR-CTA2/B resulted in greater AgI/II-specific proliferative responses in PP cells and an increase in the proportion of CD4+ T cells. Coadministration of CT with SBR-CTA2/B led to greater proliferative responses especially in the MLN cells, which then showed an increase in CD4+ cells. Immunization with SBR-CTA2/B (with or without CT) skewed the cytokine expression pattern in PP and MLN cells toward Th2. The results indicate that T helper cells were induced in gut-associated lymphoid tissues by i.g. immunization with SBR-CTA2/B, concomitantly with and prior to the appearance of circulating and mucosal antibodies.

1. The electrical properties of red muscle fibres of the silver carp (Carassius auratus(Linné)) were investigated and compared with those of white fibres. The resting membrane potential of red muscle was −73·1 mV, and of white muscle −82·4 mV. The effective resistance of fibre, time constant and space constant were 1·43 MΩ, 26·6 msec and 2·1 mm for red muscle and 1·0 MΩ, 48·4 msec and 1·9 mm for white muscle.

1. The membrane properties of the guinea‐pig ureter were studied in physiological Krebs solution by intra‐ and extracellular stimulating methods.

The effects of various chemical agents on the spontaneous membrane activities and those electrically elicited in the smooth muscles of small intestine were investigated.

The membrane properties of single cells of intestinal smooth muscle of duodenum, jejunum, ileum, caecum and rectum of guinea‐pig have been studied.

THE electrical properties of the myelinated nerve fibre in potassium-rich solution were observed by Stämpni1, Mueller2and Tasaki3. Those of the unmyelinated nerve fibre were observed by Segal4, Tasaki3and Moore5. When the membrane potential is depolarized by potassium, the potential difference across the membrane produced by the inward current pulse is larger than that produced by the outward one and exhibits a kind of discontinuous increase at a certain current intensity (the current-potential relation is non-linear). The time-course of the potential difference produced by the inward current has two steps. This phenomenon is called “anodal threshold phenomenon” by Segal4and “hyperpolarizing response” by Tasaki3. Tasaki reported that the hyperpolarizing response in the giant axon of the squid was slightly different from that in the myelinated nerve fibre.