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OBJECTIVE: To compare the applicability of two risk assessment methods for occupational health risk assessment in enterprises with 1-bromopropane(1-BP) production and utilization. METHODS: Three enterprises with 1-BP production and utilization were selected as the research subjects by a typical sampling method. The exposure concentration of time-weighted average of 1-BP-exposed in worker was detected. The non-carcinogenic health risk of 1-BP was assessed using the USA Environmental Protection Agency(EPA) inhalation risk(EPA assessment model) and the Ministry of Manpower of Singapore(MOM assessment model), and the results were compared. RESULTS: When the EPA method was used for the assessment, the risk assessment results of the four posts in the manufacturing enterprises were all negligible. In the enterprises that use 1-BP, the posts of cleaning machine B and clamping were of medium risk and the other four posts were of low risk based on the occupational exposure limit(OEL) in China used as the reference exposure concentration(RfC). When the 24-hour minimal risk level of USA Agency for Toxic Substances and Disease Registry was used as the RfC, the posts of cleaning machine B and clamping were of extreme high risk; the posts in cleaning machine A and checking were of high risk; the post in the cleaning machine D was of medium risk and the post of cleaning machine C was of low risk. When the MOM assessment model was used for evaluation, the four posts were of low risk in the 1-BP production enterprises. In the enterprises that use 1-BP, the posts of cleaning machine B and clamping were of high risk; the posts of cleaning machine A, cleaning machine D and checking were of medium risk; and the post of cleaning machine C was of low risk. CONCLUSION: When the OEL value is used for risk assessment, the MOM assessment method is more suitable than the EPA assessment method to assess occupational health risks of 1-BP.
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18F-fluoro-deoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) has been used as a crucial imaging modality for staging and prognosis evaluation in the patients with lymphoma. Since biological characteristics, treatment responses and prognosis vary in different subtypes of lymphoma, this review mainly focused on progress of 18F-FDG PET/CT evaluation in prognosis of Hodgkin lymphoma (HL) and diffused large B-cell lymphoma (DLBCL). The significance in prognostic evaluation of interim 18F-FDG PET/CT in HL is well-known, but it still remains controversy in DLBCL. Moreover, the semi-quantitative method of 18F-FDG PET/CT evaluation in lymphoma has bright future.
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Potency is one of the most important indexes of inactivated vaccines.A number of methods have been established to assay the potency,of which the NIH test and single-dose mouse protection test are the prescribed methods.Here,we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine,which uses fewer animals and takes less time to complete.Depending on the quality requirements of a vaccine(e.g.minimum potency),a rabies reference vaccine is,for example,diluted to the minimum potency,and 50 μL of the dilution is taken to inoculate 10 mice.The same amount of the test rabies vaccine is inoculated into another 10 mice.After two weeks,all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization(FAVN) test.By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine,the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality.The reliability of this method was also confirmed in dogs.The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.
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Objective: To evaluate the colonization of group mutans streptococci according to age, measuring the amount of bacteria in saliva with a semi-quantitative method in a population attended in public and private dental centers of the Metropolitan Region, Santiago, Chile. Patients and Methods: Saliva samples were obtained from 14,649 patients aged 5 to 40 years, in one public and 5 private dental centers. Bacteria concentration was estimated by the comparison with a standard counting-chart. The concentration of group mutans streptococci in saliva was test by a 3-way ANOVA. Results: Bacterial concentration of Streptococcus mutans related with the age of patients was significant (p < 0.001). Bacterial concentration in the preschool age was 4,7 x 10(5) CFU/mL at 5 years, while 6,0 x10(5) CFU/mL at 12 years of age, with a decrease in patients over 30 years. Bacterial concentration was significantly different in the six centers of the study. Conclusions: The semi-quantitative method was useful to determine the colonization by Streptococcus mutans according to age. This could help for identifying population at high risk of dental caries and to develop oral health prevention programs in specific populations.
Objetivo: Evaluar el nivel de colonización Streptococcus grupo mutans según la edad, midiendo en saliva, con un método semi-cuantitativo, la cantidad de bacterias presente en una población que acude a centros odontológicos públicos y privados de la Región Metropolitana de Chile. Pacientes y Métodos: Se obtuvieron de 14.649 muestras de saliva de pacientes incluyendo hombres y mujeres, de 5 a 40 años, en un centro de atención estatal y en cinco de atención privada. El método de recuento fue la comparación con una tabla normada de concentraciones. El análisis estadístico incluyó ANOVA. Resultados: Se encontró que el recuento de Streptococcus grupo mutans en relación a las edades de los pacientes fue significativo (p < 0,001). El recuento de bacterias en los preescolares de 5 años fue alrededor de 4.7x10(5) ufc/ mL de saliva mientras que en los niños de 12 años fue de 6.0x10(5) ufc/mL, observándose además una disminución de la carga bacteriana en los pacientes de 30 años. A edades superiores se apreció un descenso paulatino. La concentración bacteriana fue significativamente distinta en los seis centros estudiados. Conclusiones: Este método de recuento de colonias a través de la espátula permitió determinar el grado de colonización producida por Steptococcus grupo mutans según las edades, es de utilidad para identificar la población de alto riesgo de caries dentales y su aplicación ayudaría a desarrollar programas de prevención en salud oral en poblaciones especificas.