Characterization of a cell population which amplifies the anticryptococcal delayed-type hypersensitivity response.

Cell-mediated immunity to Cryptococcus neoformans can be detected by delayed-type hypersensitivity (DTH) to a culture filtrate antigen of C. neoformans. Recently, we have identified a population of cells in spleens of mice immunized with cryptococcal antigen that, when transferred to recipient mice at the time of immunization, amplifies the anticryptococcal DTH response. If the cell donor mice are treated with cyclosporin A during induction of the anticryptococcal DTH response, the amplifier cells are not induced, whereas the cells which transfer DTH (TDH cells) are induced. The purpose of this study was to characterize the amplifier cells with respect to their surface and functional properties and, in so doing, determine whether or not the amplifier cells are analogous to long-lived memory cells. We demonstrated that the amplifier cells were nylon-wool-nonadherent, antigen-specific, CD4 (L3T4+ Lyt-2-) T lymphocytes which appear in the spleens of mice 5 days postimmunization with cryptococcal culture filtrate antigen in complete Freund adjuvant. The amplifier T (Tamp) cells are not considered to be memory cells because they are relatively short-lived, being present 14 but not 18 days after the stimulating immunization. Moreover, the amplified anticryptococcal DTH response does not fulfill the criteria of the typical secondary immune (anamnestic) response in that the amplified response does not appear early relative to the appearance of the primary anticryptococcal DTH response, and it does not persist longer than the primary DTH response. We speculate that Tamp cells are not long-lived memory cells but rather act in a T-helper cell capacity to amplify the anticryptococcal DTH response.     

Resistance of T-cell receptor delta-chain-deficient mice to experimental Candida albicans vaginitis

Conditions consistent with tolerance or immunoregulation have been observed in experimental Candida albicans vaginal infections. The present study investigated the role of gamma/delta T cells in experimental vaginal candidiasis. Results showed that T-cell receptor delta-chain-knockout mice had significantly less vaginal fungal burden when compared to wild-type mice, suggesting an immunoregulatory role for gamma/delta T cells in Candida vaginitis.     

Thrombolytic therapy with recombinant streptokinase for prosthetic valve thrombosis

BACKGROUND: Thrombosis is a serious complication of prosthetic heart valves, and management is often difficult. Thrombolytic therapy is a promising alternative to valve re-operation in the prosthetic valve thrombosis. METHODS: Fifteen consecutive patients with prosthetic heart valve thrombosis (10 mitral, 3 aortic, 2 tricuspid) were treated with intravenous recombinant streptokinase: 250,000 UI given over 30 minutes followed by an infusion an 100,000 UI per hour, always with clinical monitoring and echocardiographic examinations repeated at 24, 48, and 72 hours after starting thrombolytic therapy. Doppler echocardiography was the primary method use for diagnosis and was also used to follow the response to therapy RESULTS: Fibrinolytic treatment was successful in 14 (93.3%) patients. Total response was achieved in 13 (86.6%)patients and partial response in 1 (6.7%) patient; one patient died of ventricular fibrillation. No major hemorrhagic events were observed, peripheral embolism occurred in two cases, and one case of minor peripheral bleeding occurred in another. Some patients experienced fever and chills. CONCLUSIONS: The present study demonstrates the feasibility, safety and efficacy of thrombolytic therapy, which may be considered as first-line therapy for prosthetic heart valve thrombosis.     

Co-site digital optical microscopy and image analysis: an approach to evaluate the process of dentine demineralization

AIM: To introduce and explore the potential of digital optical co-site microscopy and image analysis for the observation of changes in dentine surfaces during demineralization. The effect of ethylenediamine tetraacetic acid (EDTA) was evaluated quantitatively and longitudinally. METHODOLOGY: Three maxillary human molars were sectioned transversely at the cemento-enamel junction, and the crowns discarded. Subsequently, discs approximately 3 mm thick were cut in the cervical third of the root and a standardized smear layer produced. Co-site image sequences of the dentine surface subjected to 17% EDTA were obtained over the experimental period (15, 30, 60, 180 and 300 s). Sixteen images were obtained in each dentine sample for each experimental time, thus, a total of 48 image fields were obtained. For each field, an image analysis routine automatically discriminated open dentine tubules and measured their number, area fraction and minimum diameter, thus allowing the quantification of the demineralization process. The Student t-test was used to analyse the data. RESULTS: The number of open tubules remained essentially constant during the demineralization process. The area fraction increased from 9% to 32%. Tubule minimum diameter increased from 1.5 to 3.0 microm. The changes over time for the area fraction and minimum diameter were significant for comparison between all experimental times (P<0.05). CONCLUSIONS: The methodology developed for longitudinal observation of dentinal surfaces was fast, robust and reproducible. It could be easily extended to other chelating substances, thus contributing to the understanding of the demineralization process and in establishing an optimal time-effect relationship in the clinical application.     

Incidence of class A extended-spectrum beta-lactamases in Champagne-Ardenne (France): a 1 year prospective study

OBJECTIVES: To assess the frequency and diversity of extended spectrum beta-lactamases (ESBLs) in the Champagne-Ardenne region France, and to identify genetic elements associated with the bla(CTX-M) genes. METHODS: During 2004, all the non-duplicate isolates of Pseudomonas aeruginosa and Acinetobacter baumannii resistant to ceftazidime and of Enterobacteriaceae intermediate or resistant to ceftazidime and/or cefotaxime, screening samples excluded, were collected in 10 public hospitals and 3 private clinics. bla genes were sequenced and bla(CTX-M) environment characterized by PCR mapping. RESULTS: In Enterobacteriaceae (138/21 861; 0.6%), ESBLs were predominantly TEM-24 (n = 52; 37.7%) and CTX-M-15 (n = 37; 26.8%). Three new enzymes were identified, CTX-M-61 (CTX-M-1 group), TEM- and SHV-type. A. baumannii (n = 5) produced VEB-1 and P. aeruginosa (n = 2) SHV-2a. ISEcp1 was detected in 22/27 strains, disrupted in 7 of them. The IS903-like element was downstream of bla(CTX-M-14) and bla(CTX-M-16). ISCR1 was found upstream of bla(CTX-M-2) and bla(CTX-M-9), and ISCR1 and bla(CTX-M-2) were located on a sul1-type class 1 integron. In comparison with 2001-02, ESBL distribution among Enterobacteriaceae showed an increase in CTX-M-type (44.9% vs 3.7% P < 10(-7)) due to Escherichia coli CTX-M-15 and to the almost total disappearance of TEM-3 (0.9% vs 51.2%). E. coli was the most frequent species (50.0% vs 5.1% in 1998) despite a similar prevalence to that in 1998 (0.5% vs 0.2%). CONCLUSIONS: A careful detection of bla(CTX-M)-type spread to other species would help to anticipate clonal endemics such as those observed in Enterobacter aerogenes TEM-24.     

Full-Length Plasmodium falciparum Circumsporozoite Protein Administered with Long-Chain Poly(I·C) or the Toll-Like Receptor 4 Agonist Glucopyranosyl Lipid Adjuvant-Stable Emulsion Elicits Potent Antibody and CD4+ T Cell Immunity and Protection in Mice

The Plasmodium falciparum circumsporozoite (CS) protein (CSP) is a major vaccine target for preventing malaria infection. Thus, developing strong and durable antibody and T cell responses against CSP with novel immunogens and potent adjuvants may improve upon the success of current approaches. Here, we compare four distinct full-length P. falciparum CS proteins expressed in Escherichia coli or Pichia pastoris for their ability to induce immunity and protection in mice when administered with long-chain poly(I·C) [poly(I·C)LC] as an adjuvant. CS proteins expressed in E. coli induced high-titer antibody responses against the NANP repeat region and potent CSP-specific CD4⁺ T cell responses. Moreover, E. coli-derived CS proteins in combination with poly(I·C)LC induced potent multifunctional (interleukin 2-positive [IL-2⁺], tumor necrosis factor alpha-positive [TNF-α⁺], gamma interferon-positive [IFN-γ⁺]) CD4⁺ effector T cell responses in blood, in spleen, and particularly in liver. Using transgenic Plasmodium berghei expressing the repeat region of P. falciparum CSP [Pb-CS(Pf)], we showed that there was a 1- to 4-log decrease in malaria rRNA in the liver following a high-dose challenge and ∼50% sterilizing protection with a low-dose challenge compared to control levels. Protection was directly correlated with high-level antibody titers but not CD4⁺ T cell responses. Finally, protective immunity was also induced using the Toll-like receptor 4 agonist glucopyranosyl lipid adjuvant-stable emulsion (GLA-SE) as the adjuvant, which also correlated with high antibody titers yet CD4⁺ T cell immunity that was significantly less potent than that with poly(I·C)LC. Overall, these data suggest that full-length CS proteins and poly(I·C)LC or GLA-SE offer a simple vaccine formulation to be used alone or in combination with other vaccines for preventing malaria infection.     

Dietary Pattern among Schoolchildren with Normal Nutritional Status in Navarre,Spain

A nutrition survey was carried out (food intake registration of three consecutive school days) in a randomly selected group of 353 schoolchildren (188 males and 165 females) with normal nutritional status. The average age of the surveyed students was 10.5 years (CI 95%: 10.3–11.7). There were no significant differences between both sexes in mean values for calorie intake (males: 2072.7 ± 261.7 and females: 2060.9 ± 250.6) and intake of macronutrients, minerals and vitamins. Cereals (34%), dairy products (19%) and meats (17%) were responsible for approximately 70% of total calorie intake. Protein accounted for 20.3% of energy intake, carbohydrates for 48.8%, total fat for 30.9%, and saturated fat for 12.6%. Cholesterol intake was excessive and over two-thirds of protein intake was from animal sources. The mean intakes of calcium, iodine and Vitamins A, D and E were below recommended levels. The dietary patterns of the schoolchildren with normal nutritional status differed from the Mediterranean diet. Intakes of meat were too high and dairy products and cereals consumption was relatively limited; while that of vegetables; legumes; fruits and fish were insufficient; leading to excessive protein and fat intake from animal sources and insufficient mineral (calcium and iodine) and Vitamins A; D and E intake.     

Effect of final irrigation protocols on push‐out bond strength of an epoxy resin root canal sealer to dentin

The purpose of the present study was to evaluate the effect of different final irrigation protocols on push‐out bond strength of an epoxy resin root canal sealer to dentin. Eighty single‐rooted anterior teeth were used. The root canals were partially prepared using a rotary system and the final diameter was standardised using a #5 Gates‐Glidden drill prior to the push‐out bond test. During chemomechanical preparation, 5.25% NaOCl or 2% CHX gel was used. For smear layer removal, 17% ethylenediaminetetraacetic acid (EDTA) or QMix 2 in 1 was applied for 3 min. As final irrigant, 1 mL of NaOCl, CHX solution or distilled water was used. On conclusion of preparation, canals were filled with gutta‐percha/AH Plus sealer. Bond strength was measured by the push‐out test. Data were statistically analysed by Kruskal–Wallis and Mann–Whitney U‐tests. The group NaOCl/EDTA/NaOCl showed significantly higher bond strength values than other groups. In all groups, there were mainly mixed failure patterns. It can be concluded that 5.25% NaOCl proved to be the best solution for the final irrigation when combined with EDTA. The final irrigation protocols affect the push‐out bond strength of AH Plus to dentin.