Efficient phagocytosis of Klebsiella pneumoniae strains that poorly bind to human polymorphonuclear leukocytes

The phagocytosis process of unencapsulated MIAT-negative strains that, although binding very poorly to human polymorphonuclear leukocytes (PMN) at 4°C, are efficiently killed by these cells at 37°C, was studied. At 37°C the number of bacteria bound to the PMN external surface was similar to that observed at 4°C (about 100 bacteria/100 PMN after 60 min); on the contrary the number of internalized bacteria was much higher (from 500 bacteria/100 PMN after 60 min). Interactions between phagocytosis-sensitive Klebsiella pneumoniae strains (PSK) and PMN were then compared with those of two isogenic Escherichia coli strains with and without type 1 fimbriae. Whereas PSK strain binding to blocked PMN was very slow and became significant only after 5–6 h, that of phagocytosis-sensitive fimbriated E. coli was rapid and efficient. Phagocytosis-resistant, non fimbriated E. coli strain bound with an efficiency that, within the first 60 min, was not very different from that of the PSK strains. However, longer incubations led to increases in PSK binding, whereas unfimbriated E. coli remained constant. PSK and fimbriated E. coli strains were efficiently internalized and killed, whereas the unfimbriated E. coli strain was not. It is suggested that PMN can phagocytize unopsonized bacteria through two different mechanisms. By one mechanism, observed with the fimbriated E. coli strain, PMN bind many more bacteria than those they can internalize. By the other, observed with PSK strains, PMN bind only the bacteria they can immediately internalize

Specific Lung Mucosal and Systemic Immune-Responses After Oral Immunization of Mice with Salmonella-Typhimurium-Aroa, Salmonella-Typhi Ty21a, and Invasive Escherichia-Coli Expressing Recombinant Pertussis Toxin S1 Subunit

Pertussis toxin (PT) is considered an essential protective component for incorporation into new generation vaccines against Bordetella pertussis, the causative agent of whooping cough. Traditionally, antipertussis vaccination has employed an intramuscular route. An alternative to this approach is to stimulate mucosal and systemic immune responses by oral immunization with live vaccine carrier strains of Salmonella spp. or Escherichia coli. Recombinant S1 subunit of pertussis toxin was expressed in the attenuated aroA mutant of Salmonella typhimurium, SL3261, in the human typhoid vaccine strain Salmonella typhi Ty21a, and in E. coli CAG629 containing the Shigella flexneri plasmid pWR110, which encodes bacterial invasiveness of epithelial cells. Expression of recombinant PT S1 subunit (rPT-S1) did not affect in vitro invasiveness of the tested strains, which retained the ability to adhere to and invade the embryonic human intestinal cell line HI-407. Following oral immunization of mice with the live vaccine strains expressing rPT-S1, immunoglobulin G (IgG), IgA, and IgM responses were monitored. IgG specific to PT was detected in serum samples of mice, while IgG and IgA specific to PT were detected in lung washes after oral immunization with living Salmonella spp. or E. coli (pWR110) expressing rPT-S1. Utilization of live oral vaccines expressing B. pertussis antigens, which stimulate both a systemic and lung mucosal response, may provide an attractive alternative to purified component vaccines against whooping cough

Direct Expression of Bordetella-Pertussis Filamentous Hemagglutinin in Escherichia-Coli and Salmonella-Typhimurium Aroa

Nonfused (i.e., nonhybrid) filamentous hemagglutinin (FHA) of Bordetella pertussis was efficiently expressed in Escherichia coli K-12 and Salmonella typhimurium aroA at levels higher than those found in wild-type B. pertussis when the upstream signals of the gene were replaced and the translation initiation region was engineered to optimize translational efficiency. Inclusion of part of the C-terminal FHA open reading frame, whose translation product does not appear to be part of the major secreted species of FHA, was shown to be important in achieving protein expression in both E. coli and S. typhimurium aroA; removal of the downstream gene sequence abolished recombinant FHA production. The levels of expression observed varied widely according to the construct and host bacterium used

Compression Behavior of Fluted-Core Composite Panels

In recent years, fiber-reinforced composites have become more accepted for aerospace applications. Specifically, during NASA s recent efforts to develop new launch vehicles, composite materials were considered and baselined for a number of structures. Because of mass and stiffness requirements, sandwich composites are often selected for many applications. However, there are a number of manufacturing and in-service concerns associated with traditional honeycomb-core sandwich composites that in certain instances may be alleviated through the use of other core materials or construction methods. Fluted-core, which consists of integral angled web members with structural radius fillers spaced between laminate face sheets, is one such construction alternative and is considered herein. Two different fluted-core designs were considered: a subscale design and a full-scale design sized for a heavy-lift-launch-vehicle interstage. In particular, axial compression of fluted-core composites was evaluated with experiments and finite-element analyses (FEA); axial compression is the primary loading condition in dry launch-vehicle barrel sections. Detailed finite-element models were developed to represent all components of the fluted-core construction, and geometrically nonlinear analyses were conducted to predict both buckling and material failures. Good agreement was obtained between test data and analyses, for both local buckling and ultimate material failure. Though the local buckling events are not catastrophic, the resulting deformations contribute to material failures. Consequently, an important observation is that the material failure loads and modes would not be captured by either linear analyses or nonlinear smeared-shell analyses. Compression-after-impact (CAI) performance of fluted core composites was also investigated by experimentally testing samples impacted with 6 ft.-lb. impact energies. It was found that such impacts reduced the ultimate load carrying capability by approximately 40% on the subscale test articles and by less than 20% on the full-scale test articles. Nondestructive inspection of the damage zones indicated that the detectable damage was limited to no more than one flute on either side of any given impact. More study is needed, but this may indicate that an inherent damage-arrest capability of fluted core could provide benefits over traditional sandwich designs in certain weight-critical applications

Development of a functional stack of soil microbial fuel cells to power a water treatment reactor:From the lab to field trials in North East Brazil

Worldwide over 700 million people lack access to energy and safe water. Population growth and climate change severely stress limited freshwater reserves, and the search for innovative and sustainabledecentralised water treatment technologies is more urgent than ever; especially in vulnerable areas like North East Brazil, where water access is heavily restricted. In this context, in this study the development and implementation, from the lab to the field, of a low-cost, sustainable and self-powered system for water treatment, is presented for the first time. The system consists of an array of soil microbial fuel cells (SMFCs) that powers an electrochemical reactor for water treatment. Each SMFC is characterised by a flat geometry, with the anode embedded into the soil and the cathode exposed to air. The soil acts as the electrode separator and as a source of both electroactive bacteria and organic matter. Each SMFC generates a power of 0.4 mW, which is increased up to 12.2 mW by electrically connecting 16 SMFCs in parallel, with stable performance over 140 days of operation. An upscaled system, consisting of a stack of 64 SMFCs, was subsequently installed at a primary school in Icapuí, North East of Brazil, demonstrating a treatment capacity of up to three litres of water per day when integrated with the electrochemical reactor. By demonstrating implementation from the lab to the field, our work provides an effective route for the scalability and practical application of SMFC stacks for energy generation and self-powered water purification in remote areas.</p

TRANSVAC workshop on standardisation and harmonisation of analytical platforms for HIV, TB and malaria vaccines: 'how can big data help?'.

High-throughput analyses of RNA and protein expression are increasingly used for better understanding of vaccine-induced immunity and protection against infectious disease. With an increasing number of vaccine candidates in clinical development, it is timely to consider standardisation and harmonisation of sample collection, storage and analysis to ensure results of highest quality from these precious samples. These challenges were discussed by a group of international experts during a workshop organised by TRANSVAC, a European Commission-funded Research Infrastructure project. The main conclusions were: Platforms are rarely standardised for use in preclinical and clinical studies. Coordinated efforts should continue to harmonise the experimental set up of these studies, as well as the establishment of internal standards and controls. This will ensure comparability, efficiency and feasibility of the global analyses performed on preclinical and clinical data sets

Diagnostic Mock-Up as a Surgical Reduction Guide for Crown Lengthening: Technique Description and Case Report.

Background and Objectives: The report describes a technique using a diagnostic mock-up as a crown-lengthening surgical guide to improve the gingival architecture. Materials and Methods: The patient's primary concern was improving her smile due to her "gummy smile" and short clinical crowns. After clinical evaluation, surgical crown lengthening accompanied by maxillary central full-coverage single-unit prostheses and lateral incisor veneers was recommended. The diagnostic mock-up was placed in the patient's maxillary anterior region and used as a soft tissue reduction guide for the gingivectomy. Once the planned gingival architecture was achieved, a flap was reflected to proceed with ostectomy in order to obtain an appropriate alveolar bone crest level using the overlay. After six months, all-ceramic crowns and porcelain veneers were provided as permanent restorations. Results: A diagnostic mock-up fabricated with a putty guide directly from the diagnostic wax-up can be an adequate surgical guide for crown-lengthening procedures. The diagnostic wax-up was used to fabricate the diagnostic mock-up. These results suggested that it can be used as a crown-lengthening surgical guide to modify the gingival architecture. Several advantages of the overlay used in the aesthetic complex case include: (1) providing a preview of potential restorative outcomes, (2) allowing for the appropriate positioning of gingival margins and the desired alveolar bone crest level for the crown-lengthening procedure, and (3) serving as a provisional restoration after surgery. Conclusions: The use of a diagnostic mock-up, which was based on a diagnostic wax-up, as the surgical guide resulted in successful crown lengthening and provisional restorations. Thus, a diagnostic overlay can be a viable option as a surgical guide for crown lengthening

Costos de la aplicación de diferentes productos para el control de garrapata (Rhipicephalus microplus) en ganado vacuno

The objective of this work was to compare the costs of the application of acaricides used in the control of Rhipicephalus microplus ticks, considering the necessary inputs for the application, the personnel involved and the indirect expenses generated in each treatment. The methodology consisted of applying different products Cypermethrin®, Azuntol®, Fluazuron®, Ivermectin®, and a parasitic fungus (Metarhizium anisopliae) to control the tick and identify the costs of the application. The highest cost per year of treatment per head of cattle corresponded to Fluazuron® with an amount of $1,282.50 per head of cattle, secondly Ivermectin® with a total of$1,053.45, followed by Metarhizium anisopliae with the amount of $279.00, Azuntol® with a total of$162.85 and finally Cypermethrin® $109.93. Although the use of the parasitic fungus was not the most economical, it offers environmental advantages over the other products.El presente trabajo tuvo como objetivo realizar la comparación de costos de la aplicación de acaricidas usados en el control de garrapata Rhipicephalus microplus, considerando los insumos necesarios para la aplicación, el personal que interviene y los gastos indirectos generados en cada tratamiento. La metodología consistió en aplicar diferentes productos Cipermetrina®, Azuntol®, Fluazurón®, Ivermectina®, y un hongo parasitario (Metarhizium anisopliae) para controlar la garrapata e identificar los costos de la aplicación. El mayor costo por año de tratamiento por cabeza de ganado correspondió al Fluazuron® con un importe de$1,282.50 por cabeza de ganado, en segundo lugar la Ivermectina® con un total de $1,053.45, seguido por Metarhizium anisopliae con la cantidad de$279.00, Azuntol® con un total de $162.85 y finalmente Cipermetrina®$109.93. A pesar de que el uso del hongo parasitario no fue el más económico, este ofrece ventajas ambientales sobre los demás productos