Levels of coplanar PCBs in human breast milk at different times of lactation

New insights on the regulation of cancer cachexia by N-3 polyunsaturated fatty acids

Cancer cachexia is a multifactorial syndrome that develops during malignant tumor growth. Changes in plasma levels of several hormones and inflammatory factors result in an intense catabolic state, decreased activity of anabolic pathways, anorexia, and marked weight loss, leading to cachexia development and/or accentuation. Inflammatory mediators appear to be related to the control of a highly regulated process of muscle protein degradation that accelerates the process of cachexia. Several mediators have been postulated to participate in this process, including TNF-α, myostatin, and activated protein degradation pathways. Some interventional therapies have been proposed, including nutritional (dietary, omega-3 fatty acid supplementation), hormonal (insulin), pharmacological (clenbuterol), and nonpharmacological (physical exercise) therapies. Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid, are recognized for their anti-inflammatory properties and have been used in therapeutic approaches to treat or attenuate cancer cachexia. In this review, we discuss recent findings on cellular and molecular mechanisms involved in inflammation in the cancer cachexia syndrome and the effectiveness of n-3 PUFAs to attenuate or prevent cancer cachexia.

A national survey of polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) in Chinese mothers' milk

Seven polybrominated diphenyl ethers (PBDEs) congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) congeners (CB-28, CB-52, CB-101, CB-138, CB-153 and CB-180) were measured in 24 pooled human milk samples comprised of 1237 individual samples from 12 provinces in China. The samples were taken to estimate the background body burden of general population and assess nursing infant exposure via human milk in China. The median concentrations of ∑(7)PBDEs and ∑(6)PCBs were 1.49 and 10.50 ng g(-1) lipid weight (lw), respectively. BDE-28, BDE-47 and BDE-153 were predominant PBDE congeners accounting for nearly 70% of ∑(7)PBDEs. As for indicator PCBs, CB-153 was the most abundant congener, followed by CB-138. In our study, there was no significantly statistical relationship between concentrations of PBDEs in milk samples and maternal age as well as dietary habits. ∑(7)PBDEs did not correlate to ∑(6)PCBs in Chinese mothers' milk. The human exposure to indicator PCBs in China was found to be significantly determined by maternal age, dietary habits and geographical factors. It is suggested that Chinese general population is probably exposed to PBDEs with multiple sources and pathways. The estimated daily intakes (EDI) of BDE-47, BDE-99 and BDE-153 for the Chinese nursing infant were much lower than corresponding threshold reference values suggested by USEPA.

Occurrence of co-planar polybrominated/chlorinated biphenyls (PXBs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in breast milk of women from Spain

In this study, for the first time, levels and accumulation profiles of eight currently available polybrominated/chlorinated biphenyl congeners (PXBs; XB-77, -105, -118, -126A, -126B, -126C, -156 and -169, named according to IUPAC nomenclature) in human breast milk collected form Spanish women in 2005 were reported. Concentrations and congener specific profiles of polychlorinated biphenyls (PCBs), including co-planar PCBs, (co-PCBs) and polybrominated diphenyl ethers (PBDEs) were also reported. A concentration of 0.45 pg g(-1) lipid weight was found for total PXBs, and arithmetic mean concentrations of 125, 25 and 5.5 ng g(-1) lipid weight were determined for total PCBs, co-PCBs and total PBDEs respectively. Detectable levels of all congeners investigated, except CB-123 and XB-169 were found. Levels of PCBs were similar to those found in Spanish samples collected after 2000, and lower than those obtained before 2000. CB-138, -153 and -180 were the predominant PCB congeners. PBDE levels, dominated by BDE-47, -99, -100 and -209, were lower than PCB levels. PXB concentrations were the lowest, with XB-156 being the most abundant. The concentration levels of PCBs and PBDEs found in this study were in the same range as those from other European countries. Levels of PXBs were much lower than published values determined in Japan which were the only data found in the literature.

Spatial and temporal trends of PCDDs and PCDFs in bivalve mollusc coming from Galicia (2000-2005). Possible relationship between biometric parameters and PCDDs and PCDFs levels

Levels and specific profiles of PCDD/F congeners were determined in bivalve mollusc coming from several Rías (estuarine bays) in Galicia (Spanish northwest Atlantic coast). Three species of bivalve mollusc, Mytilus galloprovincialis, Cerstoderma edulis and Ostrea edulis, from several points of littoral collected in the period from 2000 to 2005 were analysed. WHO-TEQ concentrations ranged from 0.08 to 1.62 pg g(-1) wet weight, values below the maximum concentration established by the EU. The PCDD/PCDF congeners profile in the studied samples was dominated by 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF. The possible influence between biometric parameters (fat and condition index) and the culture type of mussel (wild or raft) on PCDDs and PCDFs levels were studied using statistical analysis. The coefficients of Pearson product-moment correlation indicated the existence of positive significant relationship between 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF levels and fat content. There was not correlation between condition index and PCDD/Fs content. ANOVA also revealed there were significant differences between SigmaPCDD/Fs, 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF levels in raft and wild mussels. Spatial and temporal trends were supported by patterns in ANOVA, using a general linear model (GLM) showing a clear separation in the composition of these compounds in more and less contaminated Rías and a decrease of PCDD/FS levels along the years.

Occurrence of PCBs, PCDD/Fs, PBDEs and DDTs in Spanish breast milk: enantiomeric fraction of chiral PCBs

Concentrations and congener specific profile of DDTs, PCBs and PCDD/Fs have been determined in a number of Spanish breast milk samples. The concentrations found indicate a decreasing tendency compared to previous data from the 1990s. Mean concentrations of 238 ng/g fat weight, 111 ng/g fat weight and 82.1 pg/g fat weight were found for DDTs, PCBs and 2,3,7,8-PCDD/Fs, respectively. When the WHO-TEQs were calculated, PCDD/Fs was the family contributing with the highest percentage to the total (62-84%), followed by the non-ortho PCBs (10-25%) and the mono-ortho PCBs (5-24%). The congener specific accumulation patterns found were comparable to those reported in other studies in industrialised countries. In addition, the levels of 9 PBDEs congeners have been also determined in the breast milk samples. The concentrations ranged from 0.04 to 1.38 ng/g fat weight. The enantiomeric enrichment of a number of chiral PCBs in the breast milk samples, including congeners 84, 91, 95, 132, 135, 149, 171, 174, 176 and 183, has also been studied, for some of them for the first time in this matrix.

Depuration of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in breast milk from California first-time mothers (primiparae)

BACKGROUND

Little is known about the rates of loss (depuration) of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) from mothers during lactation. Depuration rates affect infant exposure to chemicals during breast-feeding, and fetal and lactational transfers during subsequent pregnancies.

OBJECTIVE

Our objective in this study was to estimate depuration rates of PBDEs and PCBs using serial samples of breast milk.

METHOD

Nine first-time mothers (primiparae) each collected samples at 4, 6, 8, 12, 16, 20, and 24 weeks after birth. Nine additional primiparae each collected two samples at varying time intervals (18 to > 85 weeks after birth). Analytical precision was assessed to evaluate the accuracy of measured monthly percentage declines in PBDEs and PCBs.

RESULTS

The four major PBDE congeners decreased 2 or 3% +/- 1% per month over the 6-month period. These decreases were consistent over a 50-fold range (21-1,330 ng/g lipid weight) of initial PBDE concentrations in breast milk. The change in PCB-153 ranged from + 0.3% to -0.6% per month, with heterogeneous slopes and greater intraindividual variability. PBDE and PCB concentrations declined 1% per month over longer periods (up to 136 weeks).

CONCLUSIONS

Our data indicate that PBDEs and PCBs are not substantially (4-18%) reduced in primiparae after 6 months of breast-feeding. Consequently, the fetal and lactational exposures for a second child may not be markedly lower than those for the first. Participants were volunteers from a larger study population (n = 82), and were typical in their PBDE/PCB levels and in many demographic and lifestyle factors. These similarities suggest that our results may have broader applicability.

Levels and profiles of PCDDs, PCDFs and cPCBs in Belgian breast milk. Estimation of infant intake

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 20 non-pooled breast milk samples collected in or close to an industrial area of Wallonia (Belgium). PCDD/F concentrations ranged between 16.0 and 52.1 pg TEQ/g fat, with a mean value of 29.4 pg TEQ/g fat. If coplanar PCBs (77, 126, 169) are included in TEQ calculations, levels ranged between 22.2 and 100.2 pg TEQ/g fat, with a mean value of 40.8 pg TEQ/g fat. It appears that 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and PCB-126 account for more than 90% of the TEQ. Estimated PCDD/F dietary intake is 76 pg TEQ/kg body weight (bw)/day. This value is almost 20 times higher than the World Health Organization tolerable daily intake. A value of 103 pg TEQ/kg bw/day represents the intake of PCDDs, PCDFs and cPCBs (no mono-ortho PCBs included).

PCB congeners transferred by human milk, with an estimate of their daily intake

The degree of exposure by nursing mothers to individual polychronated biphenyl (PCB) congeners was studied and an estimate made of the daily intake by their infants. Epidemiological data from 100 nursing mothers were collected; 11 individual PCB congeners were determined in samples of the mothers' milk and the toxicity equivalent (TEQ) calculated. The mothers' data and the congener levels were statistically correlated. In over 80% of the samples, PCB congeners nos 180, 28, 138 and 170 were identified, and in over 70%, PCB congeners nos 188, 52, 187 and 153. PCB congeners nos 183, 101 and 118 were identified in percentages of between 39 and 15% of the samples. The highest levels detected were those in PCB no. 28 (1.626 ppb), and the lowest concentrations corresponded to PCB no. 183 (0.109 ppb). The toxicity equivalent (TEQ) was calculated from the toxic equivalent factor (TEF) of the congeners studied. There were no statistical differences between the geographical place of residence, age, occupation, and the congeners studied. There was a significant differentiation with respect to the birthplace, the location of industrial estates and the irrigation facilities in the area of residence, to smoking, the consumption of a varied diet, meat, fish or industrially processed foods, the physical constitution of the mothers, number of children and lactation periods, and PCB congener levels. The total PCB daily intake estimate was under the acceptable daily intake (ADI) limits of tolerance (WHO, 1988), and it was not possible to come to any conclusions for the estimated daily intake (EDI) of the 11 congeners studied since these have not yet been established. It was thus proposed to use the EDIs obtained in order to establish the ADIs of the individual PCB congeners.

Comparison of PCB congeners and pesticide levels between serum and milk from lactating women

Samples of blood and milk were obtained from lactating women participating in the New York State Angler study. A total of seven women gave one blood and one milk sample at time intervals between blood and milk collection different for each woman. The time between samples varied from 3 to 318 days. One subject provided a second milk sample 219 days after the first milk sample. The samples were analyzed for 69 PCB congeners, DDE (a metabolite of DDT), Mirex, and hexachlorobenzene (HCB). Lipid content was determined by gravimetric analysis. The congener profiles in serum and milk were similar for each individual but different among all subjects. The sum of the concentrations of the congeners present above the limit of detection was used to estimate the total PCB concentration that was in the range of 2.6 to 5.8 ng/g of serum and 3.5 to 14.1 ng/g of milk. The ratio of serum to milk concentrations varied from 0.18 to 1.66 with a mean of 0.65+/-0.49 showing no consistency among individuals prior to adjusting the data for lipid content. The total PCB levels normalized for lipid content were 320-728 ng/g of serum lipid and 239-428 ng/g of milk lipid. The range of the lipid adjusted serum/milk ratio was 1.1 to 2.8 and the mean+/-SD serum/milk ratio was 1.9+/-0.5. The ranges of lipid adjusted serum concentration of DDE, HCB, and Mirex were 95 to 591, 8 to 48, and 3 to 29 ng/g lipid, respectively. The ranges of lipid adjusted milk concentration of DDE, HCB, and Mirex were 90 to 577, 11 to 22, and 1 to 10 ng/g lipid, respectively. For DDE, HCB, and Mirex, the means of the individual lipid adjusted serum to milk ratios were 1.5+/-0.7, 2.5+/-1.5, and 5. 3+/-4.6, respectively. Considerable differences were found among lipid adjusted concentrations of these environmental pollutants in serum and milk samples from the same individual. This suggests that body burden estimates in lactating women using different matrices may not be equivalent even when lipid adjusted values are used.

Determination of polychlorinated biphenyls in soybean infant formulas by gas chromatography

A method previously developed for the analysis of organohalogenated compounds in dairy products is now validated for polychlorinated biphenyls (PCBs) determination in soybean infant formulas. The results of this study are consistent with those found for PCBs in powdered full-fat milk. The methodology is based on a solid-liquid extraction step enabling a semi-selective extraction of the apolar lipids of the matrix without affecting the efficiency for the recovery of PCBs. Mean recoveries for the spiked coplanar congeners studied were in the 88-114% range, with relative standard deviations (R.S.D.s) lower than 9.8%. The R.S.D.s related to the determination of endogenous PCBs were in the 1.5-10.0% range. The validated methodology was applied to the PCB analysis in different trademarks of soybean infant formulas commercialised in Spain. Toxic tetraequivalents of tetrachlorodibenzo-p-dioxin and daily intake corresponding to each one were calculated and compared with values previously published and with those found in literature for human breast milk in different countries.

Gas chromatography determination of polychlorinated biphenyls in powdered and liquid soybean milks

A method previously validated for the analysis of individual congeners of polychlorinated biphenyls (PCBs) in soybean infant formulas is now used to determine PCB levels in dairy-like soybean derivatives, including liquid and powdered soybean milks. Some differences were found among PCB levels and profiles calculated from the different liquid and powdered soybean milks investigated when compared to previously reported for soybean infant formulas, and those most common in dairy-products from Spain and from other countries. PCB levels detected in liquid soybean milks were lower than those found in powdered soybean milks. Levels reported for these two dairy-like derivatives were lower than those detected in soybean infant formulas. The most apparent difference among soybean derivatives and cow's milk was that individual PCB levels detected in the former were lower than those reported for the latter, except for congeners 126 and, specifically, 77, which showed the opposite trend. This feature was common to all soybean products investigated including infant formulas, powdered and liquid soybean milks.