Surface plasmon resonance modulation in nanopatterned Au gratings by the insulator-metal transition in vanadium dioxide films.

Correlated experimental and simulation studies on the modulation of Surface Plasmon Polaritons (SPP) in Au/VO2 bilayers are presented. The modification of the SPP wave vector by the thermally-induced insulator-to-metal phase transition (IMT) in VO2 was investigated by measuring the optical reflectivity of the sample. Reflectivity changes are observed for VO2 when transitioning between the insulating and metallic states, enabling modulation of the SPP in the Au layer by the thermally induced IMT in the VO2 layer. Since the IMT can also be optically induced using ultrafast laser pulses, we postulate the viability of SPP ultrafast modulation for sensing or control.

The educational value of teaching biomedical engineering history.

It has been previously argued that science and engineering undergraduate students can benefit greatly from learning the history of their discipline. In order to successfully enhance learning by introducing history into undergraduate curriculum, it would be desirable to assess what the current educational uses of history are and to understand the needs and perceptions of teachers. Nevertheless, to our knowledge no quantitative study of the role of the history of science, engineering, and technology in the classroom has been so far conducted. In this paper we present the design of a survey aimed at assessing the current perception of teachers towards using the history of biomedical engineering (HBME) to enhance learning. This survey was part of a broader project originally led by the EMBS History Committee aimed at evaluating the educational value of the HBME, both for future biomedical engineers and for the broader public. The main goals of the survey are (1) to find out the current uses of the HBME in the classroom, and (2) to identify possible obstacles to expanding the HBME in the classroom.

Structural and immunogenicity analysis of chimeric B-cell epitope constructs derived from the gp46 and gp21 subunits of the envelope glycoproteins of HTLV-1.

B-cell epitopes were selected from the gp21 and gp46 subunits of the envelope glycoprotein of human T-cell lymphotropic virus type 1 (HTLV-1) by computer-aided analyses of protein antigenicity. Molecular modeling was used to design and synthesize the epitopes as chimeric constructs with promiscuous T-helper epitopes derived either from the tetanus toxoid (amino acids 947-967) or measles virus fusion protein (amino acids 288-302). Circular dichroism measurements revealed that the peptides had a secondary structure that correlated well with the crystal structure data or predicted structure. The chimeric peptides were then evaluated for their immunogenicity in rabbits or mice. Antibodies against one of the epitopes derived from the gp21 subunit were found to be neutralizing in its ability to inhibit the formation of virus-induced syncytia. These studies underscore the importance of the gp21 transmembrane region for the development of vaccine candidates. The applicability of a chimeric approach is discussed in the context of recent findings regarding the role of gp21 transmembrane region in the viral fusion process.

Microencapsulation of a synthetic peptide epitope for HTLV-1 in biodegradable poly(D,L-lactide-co-glycolide) microspheres using a novel encapsulation technique.

A novel procedure has been developed for the encapsulation of peptide antigens in poly(lactide-co-glycolide) (PLGA) microspheres, which employs trifluoro-acetic acid (TFA) as a carrier solvent for both the polymer and antigen. The antigen/polymer solution is emulsified in mineral oil containing sorbitan trioleate (Span 85) as an emulsifier and a low level of cottonseed oil to extract the TFA. Fluoresceinisothiocyanate-labelled bovine serum albumin (FITC-BSA) was used as a model antigen to characterize the microencapsulation. Microspheres were of the desired size (<10 microm) for targeting to antigen-presenting cells, and released the model antigen slowly after an initial burst release (11%) in PBS/0.02% Tween 80 at 37 degrees C. Subsequently, a potential peptide vaccine, designated MVFMF2, for the human T-lymphotropic virus type 1 (HTLV-1 ) was encapsulated at 4.7% loading using the novel oil-in-oil method. In vivo immune responses were examined in rabbits immunized with (i) encapsulated MVFMF2 together with encapsulated adjuvant (N-acetyl-glucosamine-3yl-acetyl-L-alanyl-D-isoglutamine, nor-MDP, (ii) encapsulated MVFMF2 without adjuvant, and (iii) free peptide with adjuvant. Inoculation of the encapsulated peptide produced an antibody response similar to that of the free peptide emulsified in adjuvant. Moreover, the elevated immune response elicited by the encapsulated peptide was observed without multiple booster immunizations and irrespective of whether an adjuvant was used. Additionally, the antibodies raised against both free and encapsulated MVFMF2 had similar affinities, as judged by competitive enzyme-linked immunosorbant assay (ELISA), indicating that the encapsulated peptide retained a significant fraction of its epitopes. Hence, these results demonstrate that peptide vaccines can be encapsulated in PLGA microspheres using a common carrier solvent for both the peptide and polymer, which produces a desirable immune response in the absence of an adjuvant.

Enhanced immunogenicity of a conformational epitope of human T-lymphotropic virus type 1 using a novel chimeric peptide.

The ability of a peptide vaccine derived from the human T-lymphotropic virus type 1 (HTLV-1) surface envelope glycoprotein protein (gp46) to mimic the native protein and elicit a protective immune response has been examined. This peptide construct, designated MVFMF2, comprises amino acids (aa) 175-218 of gp46 linked by a four residue turn (GPSL) to a promiscuous T-cell epitope from the measles virus fusion protein (MVF, aa 288-302). The peptide was structurally characterized by circular dichroism (CD) spectroscopy and was found to contain alpha-helical secondary structure. The immunogenicity of MVFMF2 in rabbits and mice was evaluated by direct ELISA and competitive ELISA using peptide constructs and the recombinant protein ACH-RE3 (aa 165-306). This peptide, when administered with adjuvant (N-acetyl-glucosamine-3yl-acetyl-L-alanyl-D-isoglutamine, nor-MDP) was immunogenic in an outbred population of both rabbits and mice. Furthermore, the peptide construct was encapsulated in biodegradable microspheres of poly(D,L-lactide-co-glycolide) to eliminate booster immunization and to examine adjuvant requirements. The data indicate that MVFMF2 shows enhanced immunogenicity when encapsulated in biodegradable microspheres. Inoculation of the encapsulated peptide produced a similar humoral response to that of the free peptide, but did not require the use of adjuvant. Elicited anti-rabbit and anti-mouse antibodies recognized whole viral preparations and the recombinant protein ACH-RE3 in ELISA assays. Additionally, inoculated rabbits exhibited enhanced reactivity to viral antigens by western blot compared to non-vaccinated controls. Although anti-rabbit and anti-mouse antibodies were capable of inhibiting syncytium formation at low dilutions, rabbits were not protected from cell-associated viral challenge. Future development of vaccines to HTLV-1 may need to incorporate the ability to elicit cell-mediated immune responses in order to protect against cell-associated viral infection.

The roles of biomedical maintenance branch, automation management & informatics departments throughout a clinical information systems's life cycle.

The introduction of new technology, such as a Clinical Information System (CIS), requires hospitals to re-evaluate the roles of the Biomedical Maintenance Branch, Automation Management, and Informatics departments. This paper describes the process a 400-bed hospital underwent to resolve role ambiguity among the three activities. The institution's goal was to reach an optimal solution to using the resources offered by each activity through redrawing lines of responsibilities. This experience demonstrated that relationships among departments are dynamic and vary depending on the stage of the CIS life cycle.

Omental lipoblastoma.

Lipoblastoma is a rare benign neoplasm of fetal fat tissue. To our knowledge, only 73 cases have been reported in the English literature. This is an unusual case of an omental lipoblastoma in a 7-month-old girl.

Serous otitis media.

Serous otitis media, as seen in children, may be an insidious disease which provides few signs and symptoms. Its effects may cause significant problems in the preschool and school-age child with respect to acquisition of necessary developmental skills. The nurse practitioner can effectively diagnose, treat, and manage children with serous otitis media. An algorithm is presented to aid in effective differential diagnosis of the disease.