Breast and prostate glands affected by environmental substances (Review).

Environmental endocrine disruptor chemicals are substances that can alter the homeostasis of the endocrine system in living organisms. They can be released from several products used in daily activities. Once in the organism, they can disrupt the endocrine function by mimicking or blocking naturally occurring hormones due to their similar chemical structure. This endocrine disruption is the most important cause of the well­known hormone­associate types of cancer. Additionally, it is decisive to determine the susceptibility of each organ to these compounds. Therefore, the present review aimed to summarize the effect of different environmental substances such as bisphenol A, dichlorodiphenyltrichloroethane and polychlorinated biphenyls in both the mammary and the prostate tissues. These organs were chosen due to their association with the hormonal system and their common features in carcinogenic mechanisms. Outcomes derived from the present review may provide evidence that should be considered in future debates regarding the effects of endocrine disruptors on carcinogenesis.

Effect of polychlorinated biphenyls 118 and 153 on Th1/Th2 cells differentiation.

The objective of this study was evaluate the effect of coplanar polychlorinated biphenyls (PCB) 118-congener (PCB like-dioxin) and noncoplanar PCB 153-congener (PCB no like-dioxin) on differentiation of humans T-CD4+ lymphocytes into Th1 or Th2 subpopulations. Peripheral blood mononuclear cells (PBMC) were isolated from healthy volunteers (aged 25-30 years); T-CD4+ lymphocytes were separated from PBMC. Then, the differentiation of T-CD4+ cells into Th1 or Th2 subpopulation was performed and the intracellular cytokines analyses were assessed. No effect on IFNγ (produced by Th1 cells) production was observed when the cells were treated with both PCBs congeners. However, the PCB 118-congener induced an increase of IL-4-producing T-CD4 cells (produced by Th2 cells), PCB153 not exerted any effect on IL-4 production. The clinical significance of our data is uncertain, therefore, more studies are necessary in order to elucidate the effects generated in exposed human individual.

Structural features of cytochrome P450 1A associated with the absence of EROD activity in liver of the loricariid catfish Pterygoplichthys sp.

The Amazon catfish genus Pterygoplichthys (Loricariidae, Siluriformes) is closely related to the loricariid genus Hypostomus, in which at least two species lack detectable ethoxyresorufin-O-deethylase (EROD) activity, typically catalyzed by cytochrome P450 1 (CYP1) enzymes. Pterygoplichthys sp. liver microsomes also lacked EROD, as well as activity with other substituted resorufins, but aryl hydrocarbon receptor agonists induced hepatic CYP1A mRNA and protein suggesting structural/functional differences in Pterygoplichthys CYP1s from those in other vertebrates. Comparing the sequences of CYP1As of Pterygoplichthys sp. and of two phylogenetically related siluriform species that do catalyze EROD (Ancistrus sp., Loricariidae and Corydoras sp., Callichthyidae) showed that these three proteins share amino acids at 17 positions that are not shared by any fish in a set of 24 other species. Pterygoplichthys and Ancistrus (the loricariids) have an additional 22 amino acid substitutions in common that are not shared by Corydoras or by other fish species. Pterygoplichthys has six exclusive amino acid substitutions. Molecular docking and dynamics simulations indicate that Pterygoplichthys CYP1A has a weak affinity for ER, which binds infrequently in a productive orientation, and in a less stable conformation than in CYP1As of species that catalyze EROD. ER also binds with the carbonyl moiety proximal to the heme iron. Pterygoplichthys CYP1A has amino acid substitutions that reduce the frequency of correctly oriented ER in the AS preventing the detection of EROD activity. The results indicate that loricariid CYP1As may have a peculiar substrate selectivity that differs from CYP1As of most vertebrate.

Bioactive polychlorinated bibenzyls from the liverwort Riccardia polyclada.

GC-MS and (1)H NMR spectroscopic profiling of a CDCl 3 extract of the liverwort Riccardia polyclada (syn. R. umbrosa) revealed the presence of four main compounds bearing several chlorine atoms on a bibenzyl skeleton. Separation of a CH 2Cl 2 extract was achieved using preparative TLC, and structures 1- 4 were proposed on the basis of spectroscopic evidence. Compounds 1- 4 were active in a brine shrimp lethality bioassay ( Artemia salina). In addition, 2 and 4 displayed moderate antifeedant activity in disk-choice bioassays with Spodoptera littoralis larvae and inhibited the growth of Cladosporium herbarum cultures on TLC plates.

Motility and chemotaxis of Pseudomonas sp. B4 towards polychlorobiphenyls and chlorobenzoates.

The polychlorinated biphenyl (PCB)-degrading Pseudomonas sp. B4 was tested for its motility and ability to sense and respond to biphenyl, its chloroderivatives and chlorobenzoates in chemotaxis assays. Pseudomonas sp. B4 was attracted to biphenyl, PCBs and benzoate in swarm plate and capillary assays. Chemotaxis towards these compounds correlated with their use as carbon and energy sources. No chemotactic effect was observed in the presence of 2- and 3-chlorobenzoates. Furthermore, a toxic effect was observed when the microorganism was exposed to 3-chlorobenzoate. A nonmotile Pseudomonas sp. B4 transformant and Burkholderia xenovorans LB400, the laboratory model strain for PCB degradation, were both capable of growing in biphenyl as the sole carbon source, but showed a clear disadvantage to access the pollutants to be degraded, compared with the highly motile Pseudomonas sp. B4, stressing the importance of motility and chemotaxis in this environmental biodegradation.

Degradation of polychlorinated biphenyls (PCBs) by Staphylococcus xylosus in liquid media and meat mixture.

We investigated the growth of the meat starter Staphylococcus xylosus (10(4) cells mL(-1)) in liquid media containing 0.01 ppm of each polychlorinated biphenyls (PCBs 10, 28, 52, 138, 153, and 180) and its ability to degrade PCBs during 168 h of incubation in liquid media (10(4) cells mL(-1), 0.01 ppm of each PCB congener) and cured meat mixture (0.1% of meat starter, 1 microg g(-1) fat of each PCB congener). PCBs did not affect the growth of the starter microorganism in nutritive (brain heart infusion, BHI) or mineral salts medium (MSM) when compared to control (no PCB). S. xylosus degraded some of the PCB congeners tested. PCBs 138 and 153 were degraded both in BHI (78% and 68%, respectively; p<0.05) and in MSM (71% and 66%, respectively; p<0.05), with maximum degradation being observed within 24 h. Highly significant negative exponential relationships was observed between incubation time and concentrations of PCB 28 and 180 in BHI, as well as for PCBs 52 and 180 in MSM. In the cured meat mixture highly significant negative exponential relationship was observed between incubation time and the concentration of PCB 10. These results indicate that although S. xylosus reduced residues of various PCB congeners in liquid media, it was less effective in cured meat.

Childhood growth and exposure to dichlorodiphenyl dichloroethene and polychlorinated biphenyls.

OBJECTIVES: Dichlorodiphenyl dichloroethene (DDE) and polychlorinated biphenyls (PCB), toxic contaminants known to be persistent in the environment, may affect growth. We investigated whether growth from birth to 10 years of age is associated with blood concentrations of DDE and PCB taken at 8 years of age. STUDY DESIGN: We ambispectively followed up a cohort of 343 German children. DDE and PCB blood concentrations were determined in 1995. Height measurements were conducted prospectively between 1994 and 1997 and obtained retrospectively from each Child's Health Card. Linear regression models for repeated measurements, controlling for confounding factors, were applied. RESULTS: Growth was significantly reduced by an average of 1.8 cm (P <.0275) for girls in the highest DDE concentration quartile (>.44 microg/L in whole blood) compared with girls in the lowest quartile (0.08-0.2 microg/L). There was no observed growth effect of DDE in boys. PCB blood concentrations were not related to growth reduction in either girls or boys. CONCLUSIONS: Background level concentrations to DDE, but not PCB, during childhood are associated with a small reduction in growth for girls evident through the age of 8 years. The observed differences narrow at the year 9 examination and disappear at the year 10 examination. No effects on boys' heights were observed.

Effects of perinatal polychlorinated biphenyls and dichlorodiphenyl dichloroethene on later development.

OBJECTIVE: Determining whether early developmental effects of perinatal exposure to polychlorinated biphenyls (PCBs) or dichlorodiphenyl dichloroethene (DDE) persist. DESIGN: Cohort followed from birth; ages now 5 1/2 to 10 1/2 years. SETTING: General community. PARTICIPANTS: Volunteer sample of 859 children, of whom 712 had been examined with the McCarthy Scales of Children's Abilities at 3, 4, or 5 years; 506 sent report cards. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Neither transplacental nor breast-feeding exposure to PCBs or DDE affected McCarthy scores at 3, 4, or 5 years. There was no statistically significant relationship between poorer grades and PCB or DDE exposure by either route. CONCLUSIONS: The deficits seen in these children on the Bayley Scales of Infant Development through 2 years of age are no longer apparent.

Effect of extra-hepatic Walker sarcoma 256 on the synthesis and degradation of liver cytochromes P-450 and b5.

Extra-hepatic Walker sarcoma 256 produced a marked decrease (approximately 60%) in the levels of cytochrome P-450 and NADP-cytochrome P-450 reductase in rat liver endoplasmic reticulum, and a lesser decrease (approximately 20%) of cytochrome b5 and NADH-cytochrome b5 reductase. Polychlorinated biphenyls induced the synthesis of these cytochromes and reductases to approximately the same extent both in normal and tumor-bearing rats. The double-label technique was used to demonstrate that the synthesis of cytochromes P-450 and b5 was reduced in the liver of tumor-bearing rats. The turnover of P-450 was not affected by the tumor, whereas cytochrome b5 turnover was decreased. It is proposed that Walker sarcoma 256 mainly affects the transcription of cytochromes P-450 and b5 through a toxohormone, and that a regulatory mechanism coordinates the level of each cytochrome and its respective reductase.