Maltreatment during childhood: a risk factor for the development of endometriosis?

STUDY QUESTION: Is maltreatment during childhood (MC), e.g. sexual abuse, physical abuse, emotional abuse and neglect, associated with diagnosis of endometriosis? SUMMARY ANSWER: Childhood sexual abuse, emotional abuse/neglect and inconsistency experiences were associated with the diagnosis of endometriosis while no such association was found for physical abuse/neglect and other forms of maltreatment. WHAT IS KNOWN ALREADY: Symptoms of endometriosis such as chronic pelvic pain, fatigue and depression, are correlated with MC, as are immune reactions linked to endometriosis. These factors support a case for a potential role of MC in the development of endometriosis. STUDY DESIGN, SIZE, DURATION: The study was designed as a multicentre retrospective case-control study. Women with a diagnosis of endometriosis were matched to control women from the same clinic/doctor's office with regard to age (±3 years) and ethnic background. A total of 421 matched pairs were included in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women with endometriosis and control women were recruited in university hospitals, district hospitals, and doctors' offices in Germany, Switzerland and Austria. A German-language version of the Childhood Trauma Questionnaire (CTQ) was used to evaluate MC. Diagnosis of endometriosis was confirmed histologically and classified according to ASRM criteria. MAIN RESULTS AND THE ROLE OF CHANCE: Women with endometriosis reported significantly more often than control women a history of sexual abuse (20%/14%, P = 0.0197), emotional abuse (44%/28%, P < 0.0001), emotional neglect (50%/42%, P = 0.0123) and inconsistency experiences (53%/41%, P = 0.0007). No statistically significant differences could be demonstrated for physical abuse/neglect (31%/26%, P = 0.1738). Combinations of different abuse/neglect experiences were described significantly more often in women with endometriosis. Frequencies of other MC, i.e. violence against the mother (8%/7%, P = 0.8222), drug abuse in the family (5%/3%, P = 0.0943), mentally handicapped family members (1%/1%, P = 0.7271), suicidal intentions in the family (6%/4%, P = 0.2879) and family members in prison (1%/1%, P = 0.1597) were not statistically different in women with endometriosis and control women. LIMITATIONS, REASONS FOR CAUTION: Some control women might present asymptomatic endometriosis, which would lead to underestimation of our findings. The exclusion of pregnant women may have biased the results. Statistical power for sub-analyses of physical abuse/neglect and sexual abuse was limited. WIDER IMPLICATIONS OF THE FINDINGS: A link to MC needs to be considered in women with endometriosis. As there are effective strategies to avoid long-term consequences of MC, healthcare professionals should inquire about such experiences in order to be able to provide treatment for the consequences as early as possible. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: Endo_QoL NCT02511626.

The lanthanum precipitation method. Part 2: quantification of the conditional interaction constant between technetium(IV) and humic substances.

The interaction between colloidal Tc(IV) species and colloidal Gorleben humic substances (HS) was quantified after application of the La-precipitation method on supernatant solutions obtained under various experimental conditions but at constant ionic strength of the Gorleben groundwater (0.04M). The determined interaction constant LogKHS (2.3+/-0.3) remained unchanged over a large range of Tc(IV) and HS concentrations and was independent of the pH of the original supernatant solution (pH range 6-10), Tc(IV)-HS loading (10(-3)-10(-6)molTcg(-1) HS) and the nature of the reducing surface (Magnetite, Pyrite and Gorleben sand) used for the pertechnetate reduction. The LogKHS value determined by the La-precipitation method is lower than the LogK value obtained from a previous study where the interaction between colloidal Tc(IV) species and Gorleben humic substances was quantified using a modified Schubert approach (2.6+/-0.3). The La-precipitation method allows to accurately determine the amount of Tc(IV) associated with HS but leads to a (small) overestimation of the free inorganic Tc(IV) species.

The lanthanum precipitation method. Part 1: a new method for technetium(IV) speciation in humic rich natural groundwater.

A new and quick method for direct speciation of Tc(IV) in humic rich solutions, based on the induced aggregation of humic substances in the presence of the trivalent cation La3+, is presented. This method (the "La-precipitation method") allows flocculating all the humic substances and also the Tc(IV) associated with humic substances. The method is tested on solutions containing Tc(IV) and Gorleben humic substances. The influence of different parameters (humic substance concentration, Tc concentration, reaction time and pH) is investigated on the observed free Tc(IV) concentration after precipitation of all humic substances. None of these parameters had a (significant) influence on the observed Tc(IV) concentration in solution after addition of La3+ to Tc(IV)-HS containing solutions. It is therefore proposed that the method can be used to separate the Tc(IV) bound to humic substances from the free inorganic Tc species in solution.

Quantification of the interaction of Tc with dissolved boom clay humic substances.

Technetium-99 (Tc), a fission product of uranium-238, is an important radionuclide because of its long half-life and its high yield in radioactive waste. To elucidate the Tc geochemical behavior in reducing environments relevant to geological disposal and in the presence of humic substances (HS), experiments were set up that resulted forthe first time in the determination of an interaction constant for Tc with dissolved humic substances. A number of lab-scale Boom Clay (a possible geological underground High-Level Radioactive Waste storage site in Mol, Belgium) batch experiments were set up, combining both different initial Tc(VII) concentrations and different solid/liquid ratios. On these batches several sequential extraction steps with HS-free synthetic Boom Clay water were performed. Equilibration times were fixed at 1 week for each extraction step. Tc(VII) was found to be readily reduced to Tc(IV) by the solid Boom Clay phase. This solid phase was able to sorb Tc(IV) to a very large extent (log Kd approximately 2.5-4.0), and two sorption sinks (one of which is humic substances) were detected. In solution, Tc(IV) was mainly associated with HS. Concentrations in solution were found up to the order of 2 x 10(-6) M. The results were quantitatively described as a competition for Tc(IV) between the solid phase and the dissolved HS (Schubert-like approach). It was concluded that a hydrophobic sorption of uncharged Tc(IV) species in solution would act as the dominating interaction mechanism with HS, with an interaction constant log K(HS) = 5.3 +/- 0.3.

Evidence for the interaction of technetium colloids with humic substances by X-ray absorption spectroscopy.

Spectroscopic extended X-ray absorption fine structure (EXAFS) evidence was obtained on the chemical environment of 99Tc(IV) atoms formed upon introduction of TcO4- into four types of laboratory-scale synthetic and natural systems which mimic in situ natural reducing conditions in humic-rich geochemical environments: (a) magnetite/pyrite in synthetic groundwater in the absence of humic substances (HSs), (b) magnetite/pyrite in natural Gorleben groundwater in the presence of HSs, (c) Boom clay sediment mixed with synthetic groundwater, and (d) Gorleben sand mixed with natural Gorleben groundwater. The investigated systems obey to pH 8-9 conditions, and all measured samples show similar EXAFS spectra for Tc, which could be fitted by a hydrated TcO2 x xH2O phase. The results are interpreted as follows: upon introduction of high concentrations (millimolar to micromolar) of TcO4-to chemically reducing environments, small Tc(IV) oxidic polymers are formed, which either may aggregate into larger units (colloids) and finally precipitate or may interact in their polymeric form with (dissolved and immobile) humic substances. This latter type of interaction--Tc(IV) colloid sorption onto HSs--differs significantly from the generally accepted metal--humate complexation and therefore offers new views on the possible reaction pathways of metals and radionuclides in humic-rich environments.