International and Specialty Trends in the Use of Prophylactic Antibiotics to Prevent Infectious Complications after Insertion of External Ventricular Drainage Devices

Background  

External ventricular drains (EVD) are used as a method of diverting cerebral spinal fluid out of the cranium. After placement of these drains, it has been customary to initiate antibiotics to prevent drain-related infections. Prophylactic regimes include peri-operative and prolonged administration of antibiotics. Little evidence exists to support either regime. To determine current practices or to determine if an unintended consensus has developed, a survey was taken concerning antibiotic prophylaxis with EVD insertion.     

Oncolytic virotherapy in veterinary medicine: current status and future prospects for canine patients

Oncolytic viruses refer to those that are able to eliminate malignancies by direct targeting and lysis of cancer cells, leaving non-cancerous tissues unharmed. Several oncolytic viruses including adenovirus strains, canine distemper virus and vaccinia virus strains have been used for canine cancer therapy in preclinical studies. However, in contrast to human studies, clinical trials with oncolytic viruses for canine cancer patients have not been reported. An 'ideal' virus has yet to be identified. This review is focused on the prospective use of oncolytic viruses in the treatment of canine tumors - a knowledge that will undoubtedly contribute to the development of oncolytic viral agents for canine cancer therapy in the future.     

Influence of evolutionary events on the Indian subcontinent on the phylogeography of dengue type 3 and 4 viruses

During 1960–80 dengue disease profile in India was mild despite circulation of all four serotypes of dengue virus (DENV). Increase in disease severity with a concomitant change in the population of DENV-1 and 2 have been reported since then. To determine population dynamics of DENV-3 and 4, the envelope (E) gene sequence was determined for 16 Indian isolates of DENV-3 and 11 of DENV-4 and analyzed together with 97 DENV-3 and 43 DENV-4 global sequences.All Indian DENV-3 isolates belonged to genotype III, lineages C, D, E and F. Lineage F was newly identified and represented non-circulating viruses. Three non-conservative amino acid changes in domain I, II & III were identified during the transition from lineages F/E, associated with mild disease, to A–D, associated with severe disease. For DENV-4, the current viruses clustered in genotype I, lineage C, whilst the isolates from 1960s formed the new genotype V. A 1979 Indian isolate of DENV-4 was found to be an inter-genotypic recombinant of Sri Lankan isolate (1978) of genotype I and Indian isolate (1961) of genotype V. The rates of nucleotide substitution and time to the most recent common ancestor (tMRCA) estimated for DENV-3 (1782–1934) and DENV-4 (1719–1931) were similar to earlier reports. However, the divergence time for genotype III of DENV-3, 1938–1963, was a more accurate estimate with the inclusion of Indian isolates from the 1960s. By phylogeographical analysis it was revealed that DENV-3 GIII viruses emerged from India and evolved through Sri Lanka whilst DENV-4 emerged and dispersed from India.The present study demonstrates the crucial role that India/Sri Lanka have played in the evolution and dispersion of the major genotypes, GIII of DENV-3 and GI of DENV-4 which are more virulent and show higher dissemination potential.     

Improved hospital-level risk adjustment for surveillance of healthcare-associated bloodstream infections: a retrospective cohort study

Background  

To allow direct comparison of bloodstream infection (BSI) rates between hospitals for performance measurement, observed rates need to be risk adjusted according to the types of patients cared for by the hospital. However, attribute data on all individual patients are often unavailable and hospital-level risk adjustment needs to be done using indirect indicator variables of patient case mix, such as hospital level. We aimed to identify medical services associated with high or low BSI rates, and to evaluate the services provided by the hospital as indicators that can be used for more objective hospital-level risk adjustment.     

Evolutionary dynamics of the immunodominant repeats of the Plasmodium vivax malaria-vaccine candidate circumsporozoite protein (CSP)

The circumsporozoite protein (CSP) of Plasmodium vivax, a major target for malaria vaccine development, has immunodominant B-cell epitopes mapped to central nonapeptide repeat arrays. To determine whether rearrangements of repeat motifs during mitotic DNA replication of parasites create significant CSP diversity under conditions of low effective meiotic recombination rates, we examined csp alleles from sympatric P. vivax isolates systematically sampled from an area of low malaria endemicity in Brazil over a period of 14 months. Nine unique csp types, comprising six different nonapeptide repeats, were observed in 45 isolates analyzed. Identical or nearly identical repeats predominated in most arrays, consistent with their recent expansion. We found strong linkage disequilibrium at sites across the chromosome 8 segment flanking the csp locus, consistent with rare meiotic recombination in this region. We conclude that CSP repeat diversity may not be severely constrained by rare meiotic recombination in areas of low malaria endemicity. New repeat variants may be readily created by nonhomologous recombination even when meiotic recombination is rare, with potential implications for CSP-based vaccine development.     

Morphological changes in degrading PLGA and P(DL)LA microspheres: implications for the design of controlled release systems.

The in vitro degradation of microspheres of polymers of lactic and glycolic acids were investigated by monitoring the mass loss from the device, the molecular weight of the polymer and the morphological changes of the particles with time. Two different sequences of morphological changes were found to be operative, depending upon the polymer from which they were made--one, (I) for the high molecular weight P(DL)LA, and the other, (II) for all PLGAs and the low molecular weight P(DL)LA. Microspheres of category I showed clear evidence of heterogeneous degradation, where the initially dense microsphere developed a hollow interior. Microspheres of category II plasticized on hydration due to reduction in the Tg of the polymer below the incubation temperature of 37 degrees C. There was suppression of release of entrapped globular proteins from microspheres that underwent plasticization (category II), while slow and sustained release was seen from those that did not (category I). It is proposed that plasticization renders the matrix of category II microspheres non-porous, which prevents release by pore-diffusion. The mass loss profiles of PLGA were found to be different from those reported in the literature, in that the rates of mass loss after an initial lag time were not as rapid as has been reported. The experimental conditions used, namely the use, or otherwise, of agitation, is suggested as the reason for these differences and the need to draw a correlation between in vitro experimental conditions and in visa behaviour is emphasized.