Impact of acute exposure to air pollution on the cardiorespiratory performance of military firemen

The objective of the present study was to determine the impact of acute short-term exposure to air pollution on the cardiorespiratory performance of military fireman living and working in the city of Guarujá, São Paulo, Brazil. Twenty-five healthy non-smoking firemen aged 24 to 45 years had about 1 h of exposure to low and high levels of air pollution. The tests consisted of two phases: phase A, in Bertioga, a town with low levels of air pollution, and phase B, in Cubatão, a polluted town, with a 7-day interval between phases. The volunteers remained in the cities (Bertioga/Cubatão) only for the time required to perform the tests. Cumulative load 10 ± 2 min-long exertion tests were performed on a treadmill, consisting of a 2-min stage at a load of 7 km/h, followed by increasing exertion of 1 km h-1 min-1 until the maximum individual limit. There were statistically significant differences (P < 0.05) in anaerobic threshold (AT) between Cubatão (35.04 ± 4.91 mL kg-1 min-1) and Bertioga (36.98 ± 5.62 mL kg-1 min-1; P = 0.01), in the heart rate at AT (AT HR; Cubatão 152.08 ± 14.86 bpm, Bertioga 157.44 ± 13.64 bpm; P = 0.001), and in percent maximal oxygen consumption at AT (AT%VO2max; Cubatão 64.56 ± 6.55%, Bertioga 67.40 ± 5.35%; P = 0.03). However, there were no differences in VO2max, maximal heart rate or velocity at AT (ATvel) observed in firemen between towns. The acute exposure to pollutants in Cubatão, SP, caused a significant reduction in the performance at submaximal levels of physical exertion.

Diphtheria toxin IgG levels in military and civilian blood donors in Rio de Janeiro, Brazil

Serologic data on diseases that are preventable by vaccines are necessary to evaluate the success of immunization programs and to identify susceptible subgroups. In the present study, we determined serum IgG levels against diphtheria toxin of military and civilian blood donors (N = 75; 69.3% males and 30.7% females) aged 18-64 years, from the Brazilian Army Biology Institute, Rio de Janeiro, using a commercial diphtheria kit (Diphtheria IgG ELISA; IBL, Germany). Most (63%) unprotected military donors were from the older age group of 41 to 64 years. In contrast, the majority (71%) of young military donors (18 to 30 years) were fully protected. About half of the military donors aged 31 to 40 years were protected against diphtheria. Among the civilians, about 50% of persons aged 18 to 30 years and 31 to 40 years had protective antibody levels against diphtheria as also did 64% of individuals aged 41 to 64 years. All civilians had a similar antibody response (geometric mean = 0.55 IU/mL) independent of age group. Military donors aged 18-30 years had higher IgG levels (geometric mean = 0.82 IU/mL) than military donors of 41-64 years (geometric mean = 0.51 IU/mL; P > 0.05). In conclusion, the existence of a considerable proportion of susceptible adults supports the position that reliable data on the immune status of the population should be maintained routinely and emphasizes the importance of adequate immunization during adulthood.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based scaffolds for tissue engineering

Development and selection of an ideal scaffold is of importance for tissue engineering. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a biocompatible bioresorbable copolymer that belongs to the polyhydroxyalkanoate family. Because of its good biocompatibility, PHBHHx has been widely used as a cell scaffold for tissue engineering. This review focuses on the utilization of PHBHHx-based scaffolds in tissue engineering. Advances in the preparation, modification, and application of PHBHHx scaffolds are discussed.