Efficacy of two commercially available dentifrices in reducing dentinal hypersensitivity.

OBJECTIVE: A parallel design clinical study evaluated reduction in hypersensitivity after brushing for 12 weeks with Anchor toothpaste (containing potassium citrate, zinc citrate, triclosan and sodium monofluorophosphate) (test) and Colgate Total (sodium fluoride, silica, triclosan and copolymer) (control) dentifrices. MATERIALS AND METHODS: Sixty adults with sensitivity to hot and cold stimulus in at least two tooth surfaces were stratified at the baseline examination by tactile, hot and cold stimuli scores in two balanced groups. Subjects were randomly allocated the test and control dentifrices and evaluated after 6 and 12 weeks of dentifrice use for hypersensitivity. RESULTS: The two teeth that were selected in each patient were designated as two different sets. The 12th-week scores as compared to baseline scores for tactile, heat and cold tests in the test group showed a reduction in tooth hypersensitivity by 36.67% (P < 0.01), 20.35% (P < 0.01) and 53.64 % (P < 0.01), respectively, in the first set of teeth and 43.75% (P < 0.01), 24.48% (P < 0.01) and 59.78% (P < 0.01), respectively, in the second set of teeth. The 12th-week scores as compared to baseline scores for tactile, heat and cold tests in the control group showed a reduction in tooth hypersensitivity by 42.86% (P < 0.01), 13.02% (P < 0.01) and 45.14% (P < 0.01), respectively, in the first set of teeth and 40% (P < 0.01), 16.59% (P < 0.01) and 44.16% (P < 0.01), respectively, in the second set of teeth. CONCLUSIONS: Both the products reduced dentinal hypersensitivity in the study subjects at the end of the 12-week period. However, there was no statistically significant difference in reduction in hypersensitivity between the two products.

Sera from lupus patients inhibit growth of P. falciparum in culture.

A large number of malaria immune persons from Eastern India were found to possess antibodies to the ribosomal phosphoprotein P0 (PfP0) of the human malarial parasite Plasmodium falciparum. The characterization of PfP0 has been reported recently, and it has been shown that antibodies against PfP0 inhibit P. falciparum in vitro. About 10-15% of the patients suffering from the autoimmune disorder Systemic Lupus Erythematosus (SLE) possess autoantibodies to the human ribosomal P proteins. In order to test the cross-reactivity of the human and Plasmodium falciparum P0 proteins and to compare the SLE patients' and malaria immune persons' response, sera from 41 Indian SLE patients were tested against the P. falciparum PfP0 by Western blot analysis. Four of these samples (9.75%) were found to be cross-reactive to the carboxy-terminal domain of PfP0, but not to the amino-terminal domain of PfP0. The PfP0 reactive SLE sera inhibited the growth of Plasmodiumfalciparum in vitro. IgG purified from one such cross-reactive serum sample inhibited the growth of P. falciparum. Depletion of anti-P0 antibodies from this IgG preparation resulted in the removal of growth inhibition. Sera samples were collected from one of the PfP0 positive SLE patient from Mumbai, India, at different stages of the disease progression, and screened for the presence of anti-PfP0 antibodies. This patient's serum inhibited the parasite growth in vitro only during the phase in which anti-PfP0 antibodies were detected.

Antibodies against ribosomal phosphoprotein P0 of Plasmodium falciparum protect mice against challenge with Plasmodium yoelii.

Antibodies against the Plasmodium falciparum P0 ribosomal phosphoprotein (PfP0) have been detected exclusively but extensively in malaria-immune persons. Polyclonal rabbit and mice sera were raised against two recombinant polypeptides of P. falciparum P0 protein, PfP0N and PfP0C, covering amino acids 17 to 61 and the remaining amino acids 61 to 316, respectively. Sera against both these domains detected a 35-kDa protein from Plasmodium yoelii subsp. yoelii, a rodent malarial parasite, and stained the surface of merozoites in immunofluorescence assays. Total immunoglobulin G (IgG) purified from rabbit and mouse anti-PfP0 sera by ammonium sulfate and DEAE-cellulose chromatography was used for passive transfer experiments in mice. Mice passively immunized with both anti-PfP0N and anti-PfP0C showed distinctly lower levels of parasitemia than control mice. With immunizations on days -1, 0, 1, 3, and 5, about 50% of both sets of mice receiving anti-PfP0N and anti-PfP0C cleared the lethal 17XL strain of P. yoelii and revived by day 25. All the control mice died by day 10. By extending the immunization schedule, the survival period of the mice could be extended for every mouse that received anti-PfP0 IgG. These data demonstrate the cross-protection of the anti-PfP0 IgG and establish parasite P0 protein as a target for invasion-blocking antibodies.

Characterization of domains of the phosphoriboprotein P0 of Plasmodium falciparum.

Antibodies against the amino-terminal domain of the Plasmodium falciparum P0 phosphoriboprotein were detected extensively in immune people living in malaria endemic areas of India. It has been shown earlier that specific antibodies raised against the PfP0N domain (17-61 amino acid) of the PfP0 protein inhibit P. falciparum growth in vitro. To study the properties of the rest of the protein, the remaining 61-316 amino acids on the carboxy-side of the PfP0 protein were expressed as a glutathione-S-transferase fusion protein (PfP0C). Antibodies raised against PfP0C identified the 38 kDa P0 protein on a parasite Western blot analysis. An ELISA assay using both the PfP0N and PfP0C fusion proteins showed no reactivity with malaria patient sera samples, but showed extensive reactions with the immune sera. Antibodies against both the PfP0C and PfP0N domains were raised in rabbits and different inbred strains of mice. T-cells from immunized mice showed lymphoproliferation when presented with PfP0 protein domains. IgG from both anti-PfP0N and anti-PfP0C sera inhibited the growth of P. falciparum in vitro in a concentration dependent manner. The IgG did not show any significant effect on the growth of intraerythrocytic stages, but specifically inhibited re-invasion of red cells. Merozoites and sexual stages showed surface reactivity to both anti-PfP0N and anti-PfP0C antibodies in immunofluorescence assays. These properties strongly indicate PfP0 as a possible target for invasion-blocking antibodies.