RESUMO
A local exhaust hood was designed and built to capture and contain aerosol emissions of ribavirin during drug administration. The newly designed over-the-head hood is similar to the single hood currently used to administer the drug. This new hood was surrounded by an exhaust plenum to form a compound hood configuration. The exhaust plenum was connected to a filtered local exhaust air system to remove the waste aerosol. The compound hood and local exhaust ventilation system were evaluated for leak rate and inside hood aerosol concentration as a function of exhaust flow rates. This hood reduced the leak rate from an average of 98% with the traditional head hood to an average of less than 1% with the compound hood with exhaust port. The compound hood did not perform quite as well when not in use (set aside during infant caretaking) with the nebulizer remaining on. The leak rate was found to increase from an average of less than 1% to an average of 12% when trials were conducted that used a doll as a simulated patient versus trials without a doll, respectively. As regards therapeutic dose inside the hood, the system's performance may lead to an 18% to 25% decrease in inside hood concentration of aerosol entering the hood. Optimum hood operating parameters were identified. An exhaust flow rate in the range from 1.0 Lpm below to 1.0 Lpm above inlet flow rate from the small particle aerosol generator (SPAG nebulizer) reduced the leak rate to an average of less than 1%.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Poluentes Ocupacionais do Ar , Ribavirina/administração & dosagem , Ventilação/instrumentação , Aerossóis , Pessoal de Saúde , Humanos , Lactente , Ribavirina/toxicidadeRESUMO
With the goal of using adeno-associated viruses (AAV) as the gene-transfer vector for gene therapy of hemoglobinopathies, human beta-globin cDNA was ligated downstream from the P40 promoter of the AAV type-2 (AAV2) genome. To circumvent difficulties of cloning DNA containing palindromic sequences, two of which exist in the termini of AAV genome, a step-wise approach handling one palindrome at a time was devised to construct the chimeric expression vector. Electroporation of the construct into human 293 cells (embryonal kidney cell line) resulted in expression of the cloned human beta-globin cDNA, as evidenced by the synthesis of transcripts hybridizable to human beta-globin cDNA probe. Addition of the 3'-end region of AAV DNA that contains both the transcription termination signal and origin of DNA replication for AAV to the construct permitted the recombinant AAV genome to be rescued and replicate in the cell.
Assuntos
Replicação do DNA , DNA/genética , Dependovirus/genética , Vetores Genéticos , Globinas/genética , Transfecção , DNA Viral/genética , Genes Virais , Humanos , Regiões Promotoras Genéticas , Mapeamento por RestriçãoRESUMO
Towards a goal of using adeno-associated viruses (AAV), the human parvovirus, as the gene transfer vector for gene therapy of hemoglobinopathies, the human beta-globin (h beta G) cDNA was ligated downstream of the P40 promoter of AAV type 2 (AAV2) genome. Transfection via electroporation of the construct into human 293 cells (embryonal kidney cell line) resulted in expression of the cloned h beta G cDNA, as evidenced by the synthesis of transcripts hybridizable to h beta G probe. The transfection led to the recombinant genome to be excised out of the plasmid and replicate in the cell, followed by production of the recombinant AAV that harbors h beta G cDNA.
Assuntos
Terapia Genética , Globinas/genética , Hemoglobinopatias/terapia , Parvoviridae/genética , Southern Blotting , Linhagem Celular , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Expressão Gênica , Humanos , Plasmídeos/genética , Regiões Promotoras Genéticas , Recombinação Genética , Mapeamento por Restrição , Transfecção/genética , Replicação Viral/genéticaRESUMO
This research compared the sampling efficiencies of open- and closed-face 37 mm filter cassettes and an experimental cassette with a tapered inlet. The experiment involved challenging the cassettes with various aerosol sizes up to 24 micron Mass Median Aerodynamic Diameter (MMAD) in a wind tunnel operated at 100 cm/sec. Sampling efficiencies were determined by comparing cassette mass concentration measurements to paired isokinetic samples. It was found that sampling efficiencies dropped with increasing particle size and that the cassette with the tapered entry offered no improvement to sampling efficiency. Sampling efficiency appeared to be improved by placing cassettes on a manikin to simulate personal sampling.
Assuntos
Medicina do Trabalho/instrumentação , Aerossóis , Poeira/análiseRESUMO
The particulate filtration efficiency of industrial organic vapor sampler tubes is of interest for air sampling in work environments containing toxic materials as both vapor and particulate, or where inert particles contain adsorbed toxic material. Particulate collection efficiencies, measured with dioctylphthalate and polystyrene latex aerosols ranged from 70-90%. However, only 20% of this total is deposited on the active sorbent (charcoal granules). Considerable variability in collection efficiency between tubes was observed. Recommendations are made for obtaining improved contaminant estimates using these tubes.
Assuntos
Poluentes Ocupacionais do Ar/análise , Poluentes Atmosféricos/análise , Gases/análise , Filtração , Tamanho da PartículaRESUMO
Control of aerosol and vapor characteristics that affect the toxicity of inhaled contaminants often determines the methods of generating exposure atmospheres. Generation methods for aerosols and vapors are presented. The characteristics of the resulting exposure atmosphere and the limitations of the various generation methods are discussed. Methods and instruments for measuring the airborne contaminant with respect to various charcteristics are also described.
