Simple signage and targeted education can lead to process improvement in acute appendicitis care.

INTRODUCTION: An institution-wide protocol for uncomplicated acute appendicitis was created to improve compliance with best practices between the emergency department (ED), radiology and surgery. Awareness of the protocol was spread with the publication of a smartphone application and communication to clinical leadership. On interim review of quality metrics, poor protocol adherence in diagnostic imaging and antimicrobial stewardship was observed. The authors hypothesised that two further simple interventions would result in more efficient radiographic diagnosis and antimicrobial administration. MATERIALS AND METHODS: Surgery residents received targeted in-person education on the appropriate antibiotic choices and diagnostic imaging in the protocol. Signs were placed in the emergency and radiology work areas, immediately adjacent to provider workstations highlighting the preferred imaging for patients with suspected appendicitis and the preferred antibiotic choices for those with proven appendicitis. Protocol adherence was compared before and after each intervention. RESULTS: Targeted education was associated with improved antibiotic stewardship within the surgical department from 30% to 91% protocol adherence before/after intervention (p<0.005). Visible signs in the ED were associated with expedited antimicrobial administration from 50% to 90% of patients receiving antibiotics in the ED prior to being brought to the operating room before/after intervention (p<0.005). Diagnostic imaging after the placement of signs showed improved protocol adherence from 35% to 75% (p<0.005). CONCLUSION: This study demonstrates that smartphone-based applications and communication among clinical leadership achieved suboptimal adherence to an institutional protocol. Targeted in-person education reinforcement and visible signage immediately adjacent to provider workstations were associated with significantly increased adherence. This type of initiative can be used in other aspects of acute care general surgery to further improve quality of care and hospital efficiency.

Geospatial Assessment to Improve Time to Treatment (GAITT).

INTRODUCTION: Geographic information systems (GIS) can optimize trauma systems by identifying ways to reduce time to treatment. Using GIS, this study analyzed a system in Maryland served by Johns Hopkins Suburban Hospital and the University of Maryland Capital Region Medical Center. It was hypothesized that including Walter Reed National Military Medical Center (WRNMMC) in the Maryland trauma system in an access simulation would provide increased timely access for a portion of the local population. MATERIALS AND METHODS: Using ArcGIS Online, catchment areas with and without WRNMMC were built. Catchment areas captured Johns Hopkins Suburban Hospital, University of Maryland Capital Region Medical Center, and WRNMMC at 5-, 10-, 15-, 20-, 25-, 30-, 45-, and 60-min. Various time conditions were simulated (12 am, 8 am, 12 pm, and 5 pm) on a weekday and weekend day. Data was enriched with 19 variables addressing population size, socioeconomic status, and diversity. RESULTS: All catchment areas benefited on at least one time-day simulation, but the largest increases in mean population coverage were in the 0-5 (10.5%), 5-10 (12.3%), and 10-15 min (5.7%) catchment areas. These areas benefited regardless of time-day simulation. The lowest increase in mean population coverage was seen in the 20-25-min catchment area (0.1%). Subgroup analysis revealed that all socioeconomic status and diversity groups gained coverage. CONCLUSIONS: This study suggests that incorporating WRNMMC into the Maryland trauma system might yield increased population coverage for timely trauma access. If incorporated, WRNMMC may provide nonstop or flexible coverage, possibly in different traffic scenarios or while civilian centers are on diversion status.

On-demand, hospital-based, severe acute respiratory coronavirus virus 2 (SARS-CoV-2) genomic epidemiology to support nosocomial outbreak investigations: A prospective molecular epidemiology study.

Objectives: We evaluated the added value of infection control-guided, on demand, and locally performed severe acute respiratory coronavirus virus 2 (SARS-CoV-2) genomic sequencing to support outbreak investigation and control in acute-care settings. Design and setting: This 18-month prospective molecular epidemiology study was conducted at a tertiary-care hospital in Montreal, Canada. When nosocomial transmission was suspected by local infection control, viral genomic sequencing was performed locally for all putative outbreak cases. Molecular and conventional epidemiology data were correlated on a just-in-time basis to improve understanding of coronavirus disease 2019 (COVID-19) transmission and reinforce or adapt control measures. Results: Between April 2020 and October 2021, 6 outbreaks including 59 nosocomial infections (per the epidemiological definition) were investigated. Genomic data supported 7 distinct transmission clusters involving 6 patients and 26 healthcare workers. We identified multiple distinct modes of transmission, which led to reinforcement and adaptation of infection control measures. Molecular epidemiology data also refuted (n = 14) suspected transmission events in favor of community acquired but institutionally clustered cases. Conclusion: SARS-CoV-2 genomic sequencing can refute or strengthen transmission hypotheses from conventional nosocomial epidemiological investigations, and guide implementation of setting-specific control strategies. Our study represents a template for prospective, on site, outbreak-focused SARS-CoV-2 sequencing. This approach may become increasingly relevant in a COVID-19 endemic state where systematic sequencing within centralized surveillance programs is not available. Trial registration: clinicaltrials.gov identifier: NCT05411562.

Three-Year Safety Results of SAR422459 (EIAV-ABCA4) Gene Therapy in Patients With ABCA4-Associated Stargardt Disease: An Open-Label Dose-Escalation Phase I/IIa Clinical Trial, Cohorts 1-5.

PURPOSE: To report on the safety of the first 5 cohorts of a gene therapy trial using recombinant equine infectious anemia virus expressing ABCA4 (EIAV-ABCA4) in adults with Stargardt dystrophy due to mutations in ABCA4. DESIGN: Nonrandomized multicenter phase I/IIa clinical trial. METHODS: Patients received a subretinal injection of EIAVABCA4 in the worse-seeing eye at 3 dose levels and were followed for 3 years after treatment. MAIN OUTCOME MEASURES: The primary end point was ocular and systemic adverse events. The secondary end points were best-corrected visual acuity, static perimetry, kinetic perimetry, total field hill of vision, full field electroretinogram, multifocal ERG, color fundus photography, short-wavelength fundus autofluorescence, and spectral domain optical coherence tomography. RESULTS: The subretinal injections were well tolerated by all 22 patients across 3 dose levels. There was 1 case of a treatment-related ophthalmic serious adverse event in the form of chronic ocular hypertension. The most common adverse events were associated with the surgical procedure. In 1 patient treated with the highest dose, there was a significant decline in the number of macular flecks as compared with the untreated eye. However, in 6 patients, hypoautofluorescent changes were worse in the treated eye than in the untreated eye. Of these, 1 patient had retinal pigment epithelium atrophy that was characteristic of tissue damage likely associated with bleb induction. No patients had any clinically significant changes in best-corrected visual acuity, static perimetry, kinetic perimetry, total field hill of vision, full field electroretinogram, or multifocal ERG attributable to the treatment. CONCLUSIONS: Subretinal treatment with EIAV-ABCA4 was well tolerated with only 1 case of ocular hypertension. No clinically significant changes in visual function tests were found to be attributable to the treatment. However, 27% of treated eyes showed exacerbation of retinal pigment epithelium atrophy on fundus autofluorescence. There was a significant reduction in macular flecks in 1 treated eye from the highest dose cohort. Additional follow-up and continued investigation in more patients will be required to fully characterize the safety and efficacy of EIAV-ABCA4.

Voriconazole Sequestration During Extracorporeal Membrane Oxygenation for Invasive Lung Aspergillosis: A Case Report.

The increasing use of extracorporeal membrane oxygenation (ECMO) in critical care introduces new challenges with medication dosing. Voriconazole, a commonly used antifungal and the first-choice agent for the treatment of invasive aspergillosis, is a poorly water-soluble and highly protein-bound drug. Significant sequestration in ECMO circuits can be expected; however, no specific dosing recommendations are available. We report on the therapeutic drug monitoring and clinical evolution of a patient treated with voriconazole for invasive pulmonary aspergillosis while receiving ECMO therapy. Voriconazole trough levels were persistently low (<1 µg/mL) after initiation of ECMO despite additional loading doses and dose increases. Voriconazole dose had to be increased to 6.5 mg/kg three times daily to obtain therapeutic trough levels. The inability to achieve therapeutic levels of voriconazole for a prolonged period (a minimum of 9 days) while undergoing ECMO therapy is believed to have been a significant contributing factor in the patient's fatal outcome. Therapeutic trough levels of voriconazole cannot be guaranteed with standard dosing in patients undergoing ECMO and much higher doses may be necessary. Empirical use of higher doses and/or combination therapy may be reasonable and frequent therapeutic drug monitoring is mandatory.

Impact of cobas PCR Media freezing on SARS-CoV-2 viral RNA integrity and whole genome sequencing analyses.

SARS-CoV-2 whole genome sequencing is a molecular biology tool performed to support many aspects of the response to the pandemic. Freezing of primary clinical nasopharyngeal swabs and shipment to reference laboratories is usually required for sequencing. Cobas PCR Media transport medium facilitates high throughput SARS-CoV-2 RT-PCR analyses on cobas platforms. The manufacturer doesn't recommend freezing this transport medium because of risks of degrading molecular templates and impairing test results. Our objective was to compare the quality and results of SARS-CoV-2 genomic sequencing when performed on fresh or frozen samples in cobas PCR Media. Viral genome sequencing was performed using Oxford Nanopore Technologies MinION platform. Sequencing performance, quality and results did not significantly differ between fresh and frozen samples (n = 10). Freezing of cobas PCR Media does not negatively affect SARS-CoV-2 RNA sequencing results and it is therefore a suitable transport medium for outsourcing sequencing analyses to reference laboratories.

Comparison of SARS-CoV-2 detection with the Cobas® 6800/8800 system on gargle samples using two sample processing methods with combined oropharyngeal/nasopharyngeal swab.

BACKGROUND: Gargle samples have been proposed as a noninvasive method for detection of SARS-CoV-2 RNA. The clinical performance of gargle specimens diluted in Cobas® PCR Media and in Cobas® Omni Lysis Reagent was compared to oropharyngeal/nasopharyngeal swab (ONPS) for the detection of SARS-CoV-2 RNA. STUDY DESIGN: Participants were recruited prospectively in two COVID-19 screening clinics. In addition to the ONPS, participants gargled with 5 ml of natural spring water split in the laboratory as follows: 1 ml was added to 4.3 ml of polymerase chain reaction (PCR) media and 400 µl was added to 200 µl of lysis buffer. Testing was performed with the Cobas® SARS-CoV-2 test on the Cobas® 6800 or 8800 platforms. RESULTS: Overall, 134/647 (20.7%) participants were considered infected because the ONPS or at least one gargle test was positive. ONPS had, respectively, a sensitivity of 96.3% (95% confidence interval [CI]: 91.3-98.5); both gargle processing methods were slightly less but equally sensitive (90.3% [95% CI: 83.9-94.3]). When ONPS and gargle specimens were both positive, the mean cycle threshold (Ct ) was significantly higher for gargles, suggesting lower viral loads. CONCLUSION: Gargle specimens directly added in PCR Media provide a similar clinical sensitivity to chemical lysis, both having a slightly, not significantly, lower sensitivity to ONPS.

Comparison of saliva with oral and nasopharyngeal swabs for SARS-CoV-2 detection on various commercial and laboratory-developed assays.

The accurate laboratory detection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a crucial element in the fight against coronavirus disease 2019 (COVID-19). Reverse transcription-polymerase chain reaction testing on combined oral and nasopharyngeal swab (ONPS) suffers from several limitations, including the need for qualified personnel, the discomfort caused by invasive nasopharyngeal sample collection, and the possibility of swab and transport media shortage. Testing on saliva would represent an advancement. The aim of this study was to compare the concordance between saliva samples and ONPS for the detection of SARS-CoV-2 on various commercial and laboratory-developed tests (LDT). Individuals were recruited from eight institutions in Quebec, Canada, if they had SARS-CoV-2 RNA detected on a recently collected ONPS, and accepted to provide another ONPS, paired with saliva. Assays available in the different laboratories (Abbott RealTime SARS-CoV-2, Cobas® SARS-CoV-2, Simplexa™ COVID-19 Direct, Allplex™ 2019-nCoV, RIDA®GENE SARS-CoV-2, and an LDT preceded by three different extraction methods) were used to determine the concordance between saliva and ONPS results. Overall, 320 tests were run from a total of 125 saliva and ONPS sample pairs. All assays yielded similar sensitivity when saliva was compared to ONPS, with the exception of one LDT (67% vs. 93%). The mean difference in cycle threshold (∆C t ) was generally (but not significantly) in favor of the ONPS for all nucleic acid amplification tests. The maximum mean ∆​​​​​C t was 2.0, while individual ∆C t varied importantly from -17.5 to 12.4. Saliva seems to be associated with sensitivity similar to ONPS for the detection of SARS-CoV-2 by various assays.

Regulation of invariant NKT cell development and function by a 0.14 Mbp locus on chromosome 1: a possible role for Fcgr3.

Invariant NKT (iNKT) cells are tissue-resident innate-like T cells critical to the host immune response. We previously identified a 6.6 Mbp region on chromosome 1 as a major regulator of iNKT cell number and function in C57BL/6 and 129X1/SvJ mice. Here, we fine-mapped this locus by assessing the iNKT cell response to alpha-galactosylceramide (αGalCer) in a series of B6.129 congenic lines. This analysis revealed the presence of at least two genetic elements that regulate iNKT cell cytokine production in response to αGalCer. While one of these genetic elements mapped to the B6.129c6 interval containing Slam genes, the dominant regulator in this region mapped to the 0.14 Mbp B6.129c3 interval. In addition, we found that numbers of thymic iNKT cells and DP thymocytes were significantly lower in B6.129c3 mice, indicating that this interval also regulates iNKT cell development. Candidate gene analysis revealed a fivefold increase in Fcgr3 expression in B6.129c3 iNKT cells, and we observed increased expression of FcγR3 protein on B6.129c3 iNKT cells, NK cells, and neutrophils. These data identify the B6.129c3 interval as a novel locus regulating the response of iNKT cells to glycosphingolipid, revealing a link between this phenotype and a polymorphism that regulates Fcgr3 expression.

Hiding in plain sight: A case of fever, rash, and jaundice.

A 25-year-old man presented to the emergency department with a 3-day history of fever, anorexia, jaundice, and a generalized skin eruption. His liver function tests showed marked cholestatic and cytolytic abnormalities without liver insufficiency. A liver biopsy was performed, and morphology with routine stains was considered non-specific. Because of the dermatological findings, the non-specific biopsy morphology, and the absence of an identified infectious etiology, a diagnosis of Kawasaki disease was presumed. However, additional colorations on liver biopsy with Warthin-Starry stain revealed multiple thin and coiled microorganisms compatible with spirochetes. His serology for leptospirosis was found to be positive for IgM, supporting the diagnosis of acute leptospirosis with liver involvement. Our case illustrates the diagnostic challenge of leptospirosis and highlights the utility of conventional laboratory tests to confirm the diagnosis. Exceptionally, Warthin-Starry stain allowed the identification of leptospires in liver biopsy and confirmed liver involvement of systemic leptospirosis.

Un homme de 25 ans a consulté à l'urgence parce qu'il faisait de la fièvre depuis trois jours, de l'anorexie, un ictère et une éruption cutanée généralisée. Les tests de fonction hépatique ont révélé des anomalies cholestatiques et cytolytiques marquées, sans insuffisance hépatique. La coloration standard de la biopsie hépatique a révélé une morphologie cellulaire considérée comme non spécifique. Compte tenu des observations dermatologiques, de la morphologie non spécifique de la biopsie et de l'absence d'étiologie infectieuse établie, un diagnostic de maladie de Kawasaki a été présumé. Cependant, l'ajout d'une coloration de Warthin-Starry a révélé de multiples microorganismes minces et torsadés compatibles avec des spirochètes. La sérologie pour la leptospirose s'est avérée positive pour les anticorps IgM, appuyant un diagnostic de leptospirose aiguë avec atteinte hépatique. Ce cas illustre les difficultés diagnostiques de la leptospirose et fait ressortir l'utilité des tests de laboratoire traditionnels pour confirmer le diagnostic. Exceptionnellement, la coloration de Warthin­Starry a permis d'observer des leptospires à la biopsie hépatique et confirmé la leptospirose systémique avec atteinte hépatique.

SAR228810: an antibody for protofibrillar amyloid ß peptide designed to reduce the risk of amyloid-related imaging abnormalities (ARIA).

BACKGROUND: Anti-amyloid ß (Aß) immunotherapy represents a major area of drug development for Alzheimer's disease (AD). However, Aß peptide adopts multiple conformations and the pathological forms to be specifically targeted have not been identified. Aß immunotherapy-related vasogenic edema has also been severely dose limiting for antibodies with effector functions binding vascular amyloid such as bapineuzumab. These two factors might have contributed to the limited efficacy demonstrated so far in clinical studies. METHODS: To address these limitations, we have engineered SAR228810, a humanized monoclonal antibody (mAb) with limited Fc effector functions that binds specifically to soluble protofibrillar and fibrillar forms of Aß peptide and we tested it together with its murine precursor SAR255952 in vitro and in vivo. RESULTS: Unlike gantenerumab and BAN2401, SAR228810 and SAR255952 do not bind to Aß monomers, low molecular weight Aß oligomers or, in human brain sections, to Aß diffuse deposits which are not specific of AD pathology. Both antibodies prevent Aß42 oligomer neurotoxicity in primary neuronal cultures. In vivo, SAR255952, a mouse aglycosylated IgG1, dose-dependently prevented brain amyloid plaque formation and plaque-related inflammation with a minimal active dose of 3 mg/kg/week by the intraperitoneal route. No increase in plasma Aß levels was observed with SAR255952 treatment, in line with its lack of affinity for monomeric Aß. The effects of SAR255952 translated into synaptic functional improvement in ex-vivo hippocampal slices. Brain penetration and decoration of cerebral amyloid plaques was documented in live animals and postmortem. SAR255952 (up to 50 mg/kg/week intravenously) did not increase brain microhemorrhages and/or microscopic changes in meningeal and cerebral arteries in old APPSL mice while 3D6, the murine version of bapineuzumab, did. In immunotolerized mice, the clinical candidate SAR228810 demonstrated the same level of efficacy as the murine SAR255952. CONCLUSION: Based on the improved efficacy/safety profile in non-clinical models of SAR228810, a first-in-man single and multiple dose administration clinical study has been initiated in AD patients.

A New Promoter Allows Optogenetic Vision Restoration with Enhanced Sensitivity in Macaque Retina.

The majority of inherited retinal degenerations converge on the phenotype of photoreceptor cell death. Second- and third-order neurons are spared in these diseases, making it possible to restore retinal light responses using optogenetics. Viral expression of channelrhodopsin in the third-order neurons under ubiquitous promoters was previously shown to restore visual function, albeit at light intensities above illumination safety thresholds. Here, we report (to our knowledge, for the first time) activation of macaque retinas, up to 6 months post-injection, using channelrhodopsin-Ca2+-permeable channelrhodopsin (CatCh) at safe light intensities. High-level CatCh expression was achieved due to a new promoter based on the regulatory region of the gamma-synuclein gene (SNCG) allowing strong expression in ganglion cells across species. Our promoter, in combination with clinically proven adeno-associated virus 2 (AAV2), provides CatCh expression in peri-foveolar ganglion cells responding robustly to light under the illumination safety thresholds for the human eye. On the contrary, the threshold of activation and the proportion of unresponsive cells were much higher when a ubiquitous promoter (cytomegalovirus [CMV]) was used to express CatCh. The results of our study suggest that the inclusion of optimized promoters is key in the path to clinical translation of optogenetics.

The role of CD1d-restricted NKT cells in the clearance of Pseudomonas aeruginosa from the lung is dependent on the host genetic background.

Pseudomonas aeruginosa is an important human opportunistic pathogen, accounting for a significant fraction of hospital-acquired lung infections. CD1d-restricted NKT cells comprise an unusual innate-like T cell subset that plays important roles in both bacterial and viral infections. Previous reports have differed in their conclusions regarding the role of NKT cells in clearance of P. aeruginosa from the lung. Since there is significant strain-dependent variation in NKT cell number and function among different inbred strains of mice, we investigated whether the role of NKT cells was dependent on the host genetic background. We found that NKT cells did indeed play a critical role in the clearance of P. aeruginosa from the lungs of BALB/c mice but that they played no discernible role in clearance from the lungs of C57BL/6 mice. We found that the strain-dependent role of NKT cells was associated with significant strain-dependent differences in cytokine production by lung NKT cells and that impaired clearance of P. aeruginosa in BALB/c CD1d(-/-) mice was associated with an increase in neutrophil influx to the lung and increased levels of proinflammatory cytokines and chemokines after infection. Finally, we found that the role of alveolar macrophages was also dependent on the genetic background. These data provide further support for a model in which the unusually high level of variability in NKT cell number and function among different genetic backgrounds may be an important contributor to infectious-disease susceptibility and pathology.

Polymorphisms in the CD1d promoter that regulate CD1d gene expression are associated with impaired NKT cell development.

CD1d-restricted NKT cells comprise an innate-like T cell population that exerts significant influence over early events in the developing immune response. The frequency of NKT cells is highly variable in humans and in mice, but the basis for this variability remains unclear. In this study, we report a striking deficiency of type I NKT cells in the wild-derived inbred strains PWD/PhJ, SPRET/EiJ, and CAST/EiJ. Investigation of the underlying basis for the lack of type I NKT cells revealed that one strain, PWD/PhJ, exhibited a significant impairment in thymocyte and splenocyte CD1d gene and protein expression. Accordingly, both thymocytes and bone marrow-derived dendritic cells from PWD mice exhibited a significant impairment in the ability to present α-galactosylceramide to NKT cells. The impaired PWD CD1d gene expression was due to impaired CD1d promoter activity. Fine-mapping of the promoter activity revealed that two single nucleotide substitutions at positions -331 and -164 in the proximal promoter were each sufficient to account for the diminished PWD CD1d promoter activity. Examination of the strain distribution pattern of these polymorphisms revealed that, of 19 strains analyzed, only PWD and PWK mice possessed both CD1d promoter polymorphisms. A subsequent examination of the PWK strain revealed that it also exhibited impaired thymocyte CD1d expression and very low numbers of NKT cells. Taken together, these results provide new insight into the control of CD1d gene expression, and they have implications for the evolution of CD1d and type I NKT cells.

Translational control of NKT cell cytokine production by p38 MAPK.

NKT cells are known to rapidly produce a large amount of cytokines upon activation. Although a number of signaling pathways that regulate the development of NKT cells have been identified, the signaling pathways involved in the regulation of NKT cell cytokine production remain unclear. In this study, we show that the p38 MAPK pathway is dispensable for the development of NKT cells. However, NKT cell cytokine production and NKT-mediated liver damage are highly dependent on activation of this pathway. p38 MAPK does not substantially affect cytokine gene expression in NKT cells, but it regulates the synthesis of cytokines through the Mnk-eIF4E pathway. Thus, in addition to gene expression, translational regulation by p38 MAPK could be a novel mechanism that contributes to the overall production of cytokine by NKT cells.

ABCA2 is a strong genetic risk factor for early-onset Alzheimer's disease.

Recent epidemiological, biological and genetic data indicate a relationship between cholesterol and Alzheimer's disease (AD) including the association of polymorphisms of ABCA1 (a gene that is known to participate in cholesterol and phospholipid transport) with AD prevalence. Based on these data, we postulated that genetic variation in the related and brain-specific ABCA2 gene leads to increase risk of AD. A large case-control study was conducted where the sample was randomly divided into a hypothesis-testing sample (230 cases/286 controls) and a validation sample (210 cases/233 controls). Among the 45 SNPs we tested, one synonymous SNP (rs908832) was found significantly associated with AD in both samples. Additional analyses performed on the whole sample showed a very strong association between this marker and early-onset AD (OR = 3.82, 95% C.I. = [2.00 - 7.30], P = 5 x 10(-5)). Further research is needed to understand the functional role of this polymorphism. However, together with the reported associations of AD with APOE, CYP46A1 and ABCA1, the present result adds a very significant support for the role of cholesterol and phospholipid homeostasis in AD and a rationale for testing novel cholesterol homeostasis-related therapeutic strategies in AD.

Massive CA1/2 neuronal loss with intraneuronal and N-terminal truncated Abeta42 accumulation in a novel Alzheimer transgenic model.

Alzheimer's disease (AD) is characterized by a substantial degeneration of pyramidal neurons and the appearance of neuritic plaques and neurofibrillary tangles. Here we present a novel transgenic mouse model, APP(SL)PS1KI that closely mimics the development of AD-related neuropathological features including a significant hippocampal neuronal loss. This transgenic mouse model carries M233T/L235P knocked-in mutations in presenilin-1 and overexpresses mutated human beta-amyloid (Abeta) precursor protein. Abeta(x-42) is the major form of Abeta species present in this model with progressive development of a complex pattern of N-truncated variants and dimers, similar to those observed in AD brain. At 10 months of age, an extensive neuronal loss (>50%) is present in the CA1/2 hippocampal pyramidal cell layer that correlates with strong accumulation of intraneuronal Abeta and thioflavine-S-positive intracellular material but not with extracellular Abeta deposits. A strong reactive astrogliosis develops together with the neuronal loss. This loss is already detectable at 6 months of age and is PS1KI gene dosage-dependent. Thus, APP(SL)PS1KI mice further confirm the critical role of intraneuronal Abeta(42) in neuronal loss and provide an excellent tool to investigate therapeutic strategies designed to prevent AD neurodegeneration.

Methods for rapid separation and concentration of bacteria in food that bypass time-consuming cultural enrichment.

The rapid detection of pathogenic organisms that cause foodborne illnesses is needed to insure food safety. Conventional methods for the detection of pathogens in foods are time-consuming and labor-intensive. New advanced rapid methods (i.e., polymerase chain reaction, DNA probes) are more sensitive and selective than conventional techniques, but many of these tests are inhibited by food components, rendering them dependent on slow cultural enrichment. The need for alternative methods that will rapidly separate and concentrate bacteria directly from food samples, thereby reducing the time required for these new rapid detection techniques, is evident. Separation and concentration methods extract target bacteria from interfering food components and/or concentrate bacteria to detectable levels. This review describes several methods used to separate and/or concentrate bacteria in food samples. Several methods discussed here, including centrifugation and immunomagnetic separation, have been successfully used, individually and in combination, to rapidly separate and/or concentrate bacteria from food samples in less time than is required for cultural enrichment.