Learning from SARS Preparing for the Next Disease Outbreak: Workshop Summary (2004) / Chapter Skim
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4. Diagnostics, Therapeutics, and Other Technologies to Control SARS
4. Diagnostics, Therapeutics, and Other Technologies to Control SARS
Pages 173-205
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From page 173... ...
, a method to detect viral nucleic acids, is considered to be a likely platform for early SARS testing due to its high analytical sensitivity and speed. An evaluation of two RT-PCR protocols presented in this chapter found them to be highly specific for the SARS coronavirus; however, the tests were determined to be insufficiently sensitive to reliably detect the virus in respiratory specimens.
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From page 174... ...
Research has proceeded rapidly to develop antiviral drugs and vaccines to combat SARS. Previous antiviral discovery efforts by researchers at Pfizer on the human rhinovirus protease 3C -- a functional, genetic, and structural analog to a key SARS coronavirus protease that has therefore been named "3C-like" (3CL)
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severe acute respiratory syndrome (SARS) network laboratories (WHO SARS network laboratories at The University of Hong Kong [WHO-HKU]
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For each patient, paired acute- and convalescent-phase serum samples and at least one respiratory specimen were collected for study. A total of 303 specimens (124 nasopharyngeal aspirate specimens, 65 throat swab specimens, 95 urine specimens, and 19 stool specimens)
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177 of 1°C/cycle) buffer by (http://www/ Gold product primer volume online (Roche)
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A sample was scored as a positive result if the fluorescent intensity was equal to or higher than that of the positive control. Determination of the End Points of the RT-PCR Assays A 96-well microtiter plate containing 0.1 ml of confluent Vero cells was used to determine the 50 percent tissue culture infective dose (TCID50)
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From page 179... ...
Using seroconversion as the gold standard for SARS diagnosis, the sensitivities of the WHO-HKU and WHO-Hamburg RT-PCR assays were found to be 61 and 68 percent (nasopharyngeal aspirate specimens) , 65 and 72 percent (throat swab specimens)
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180 and positive 43 0 33 39 11 0 0 samples six assay WHO-HKU WHO-Hamburg B, Both virus RT-PCR by nxa influe positive 49 39 42 12 0 0 for SARS WHO-Hamburg with positive specimens of sample No. done.
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for providing DNA primers used in the WHO-Hamburg RT-PCR protocol. We also thank the staff of the Department of Microbiology, Queen Mary Hospital, The University of Hong Kong for their technical assistance.
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of the PCR amplicons. The measured base compositions from strategically selected locations of the genome are used as a signature to identify and distinguish the organisms present in the original sample.
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183 to to to rs intact sample. number back a prime each primers accuracy.
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During the SARS epidemic outbreak in early 2003, we demonstrated that the above-described paradigm of identification of microbial nucleic acid signatures by mass spectrometry could be adapted to identify the SARS virus. In the absence of a SARS genome sequence at the onset of the epidemic, pairs of broad primers that were designed to broadly target all other known coronaviruses were used to test clinical isolates obtained from the Centers for Disease Control and Prevention (CDC)
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From page 185... ...
Clonal propagation of specific infectious agents, as occurs in the epidemic outbreak of infectious disease, can be tracked with base composition signatures, analogous to the pulse field gel electrophoresis fingerprinting patterns used in tracking the spread of specific food pathogens in the CDC Pulse Net system (Swaminathan et al., 2001)
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. Severe acute respiratory syndrome (SARS)
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DIAGNOSTICS, THERAPEUTICS, AND OTHER TECHNOLOGIES 187 P4 P3 P2 P1 O NH O O H3C N N H H O N O CO2Et F AG7088 O NH O O N H3C N N H H O N O CO2Et AG7404 O NH O N H CO2Et AG7122 FIGURE 4-2 Compounds tested in cell culture for antiviral activity against SCoV.
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From page 188... ...
In this communication, we report an alternate computational assessment of the potential for several Pfizer compounds to inhibit SARS 3CL along with their experimentally determined antiviral activities against SCoV in cell culture. Our homology model for SARS 3CL protease was created using the atomic coordinates of TGEV 3CL protease (PDB accession code 1LVO)
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as an orally delivered compound. Unfortunately, our computational evaluation detected relatively poor complementarity between the compounds' P3 and P4 substituents and SARS 3CL that resulted in numerous TABLE 4-3 Residues Employed for the Superposition of Human Rhinovirus (HRV)
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. Bottom: AG7088 docked into the SCoV 3CL protease homology model (Connolly surface shown)
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to inhibit the SARS virus in cell culture was evaluated. Stocks of tested compounds were made by dissolving them in DMSO to a concentration of 20 mg/mL.
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AG7088 >100 >100 AG7404 >100 >100 AG7122 14.1 >100 observed activity of AG7088 and AG7404 against SCoV in cell culture. While this inactivity is disappointing, the antiviral effects displayed by AG7122 encouragingly suggest that proper optimization of such Michael acceptor-containing protease inhibitors may lead to agents with improved anti-SCoV properties.5 Since the majority of the Michael acceptors contained in the Pfizer chemical archive are optimized against HRV 3CP, we do not anticipate that their exhaustive screening against SCoV will afford ideal therapeutic agents.
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FailSafe has not used these devices directly in an outbreak of severe acute respiratory syndrome (SARS) , and thus actual clinical experience will not be reported here.
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From page 194... ...
Both of the Medical Isolation Units can be rolled to the location of a suspected infected patient, where aerosols containing SARS viruses are drawn into the system while clean air is filtered and recirculated into the air. The flexibility of the FASS Medical Isolation Units allows for a wide variety of applications: · Immediate isolation of patients with SARS, tuberculosis, or unknown respiratory infection.
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· Removal of toxic smoke or fumes. The FASS Medical Isolation Units offer the following benefits: · Minimal set-up time to respond immediately to an emergency situation.
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· Clean air for extended use. FASS Applications The FASS Medical Isolation Units are fume hoods on wheels that combine the proven HEPA filter capacity of 99.97 percent capture at 0.1 microns with ultraviolet light.
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The FailSafe Mobile Containment Systems also have the capability of generating very high ozone levels that can be used for neutralizing pathogens on surfaces such as walls, ceilings, and floors. Setup and Operation The Medical Isolation Units for health care are designed with operational simplicity to make it a "turnkey" operation and to allow health providers to focus on the individual patient and the biological contamination itself.
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From page 198... ...
There are no adverse safety, health, or environmental aspects to HEPA filters. HEPA filters are now the primary filtration media for electronic clean room assembly, hospital surgery rooms, bioengineering, pharmaceutical processes, and any applications where maximum reduction or removal of submicron particulates is required.
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From page 199... ...
Ultraviolet radiation, in the wavelength range of 2,250 to 3,020 angstroms as used for air/surface disinfection and sterilization, is referred to as ultraviolet germicidal irradiation or UVGI. Ultraviolet germicidal radiation was first applied to disinfect water systems in 1909.
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The upper limit of kill rate is obtained by mixing the air within the UVGI exposure chamber. This mixed airflow will have an average velocity that will determine the exposure time required for all microbes in the air stream.
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Air cleaners based on ozone must not generate ozone levels above the Public Health Standards, which are far below any antimicrobial activity or effective odor control. Low ozone concentrations, below the EPA-acceptable indoor limit, have been used as air cleaners, but their effectiveness has been questioned by many studies (Dyas et al., 1983; Foard et al., 1997)
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(ACH) 9' × 12' × 8' 864 43.8 62.5 125.0 12' × 12' × 8' 1,152 32.8 46.9 93.8 15' × 12' × 8' 1,440 26.3 37.5 75.0 15' × 20' × 8' 2,400 15.8 22.5 45.0 20' × 20' × 8' 3,200 11.8 16.9 33.8 20' × 30' × 8' 4,800 7.9 11.3 22.5 30' × 30' × 8' 7,200 5.3 7.5 15.0 Summary The described FASS Medical Isolation Units are available in the United States, Canada, and Asia from FailSafe Air Safety Systems Corporation of Tonawanda, NY.
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2003. Epidemiological determinants of spread of causal agent of severe acute respiratory syndrome in Hong Kong.
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2003. A major outbreak of severe acute respiratory syndrome in Hong Kong.
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2003. A cluster of cases of severe acute respiratory syndrome in Hong Kong.
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