Experience and results of office hysteroscopy at a primary hospital.

Our aim was to analyse, retrospectively, the perioperative outcomes of 3,488 office hysteroscopies. Age, menopausal status, parity, medical indications, use or not of anaesthesia, incidents, presence of pathology in the cavity, endometrial pathology, type of surgery and pain assessment details were collected. The mean age of patients was 52.1 years. The most common medical indication was suspicious ultrasound for endometrial disease, and the most frequent symptom was metrorrhagia. We did not use any type of anaesthesia in 89.5% of patients and we could access the uterine cavity in 99.4% of cases. The complication rate was very low though 12% of patients reported severe pain while performing the test. Although office hysteroscopy in outpatients is fully established and is usually well tolerated, there is a group of patients who could benefit from analgesic treatment prior to the test, to improve their tolerance.

Revealing the role of land-use features on macrolitter distribution in Swiss freshwaters.

Macrolitter, especially macroplastics, (> 0.5 cm) negatively impact freshwater ecosystems, where they can be retained along lake shores, riverbanks, floodplains or bed sediments. Long-term and large-scale assessments of macrolitter on riverbanks and lake shores provide an understanding of litter abundance, composition, and origin in freshwater systems. Combining macrolitter quantification with hydrometeorological variables allows further study of leakage, transport, and accumulation characteristics. Several studies have explored the role of hydrometeorological factors in influencing macrolitter distribution and found that river discharge, runoff, and wind only partially explains its distribution. Other factors, such as land-use features, have not yet been thoroughly investigated. In this study, we provide a country-scale assessment of land-use influence on macrolitter abundance in freshwater systems. We analyzed the composition of the most commonly found macrolitter items (referred to as 'top items', n = 42,565) sampled across lake shores and riverbanks in Switzerland between April 2020 and May 2021. We explored the relationship between eleven land-use features and macrolitter abundance at survey locations (n = 143). The land-use features included buildings, city centers, public infrastructure, recreational areas, forests, marshlands, vineyards, orchards, other land, and rivers and canals. The majority of top items are significantly and positively correlated with land-use features related to urban coverage, notably roads and buildings. Over 60% of top items were found to be correlated with either roads or buildings. Notably, tobacco, food and beverage-related products, as well as packaging and sanitary products, showed strong associations with these urban land-use features. Other types of items, however, did not exhibit a relationship with land-use features, such as industry and construction-related items. Ultimately, this highlights the need to combine measures at the local and regional/national scales for effective litter reduction.

Less-studied TCE: are their environmental concentrations increasing due to their use in new technologies?

The possible environmental impact of the recent increase in use of a group of technology-critical elements (Nb, Ta, Ga, In, Ge and Te) is analysed by reviewing published concentration profiles in environmental archives (ice cores, ombrotrophic peat bogs, freshwater sediments and moss surveys) and evaluating temporal trends in surface waters. No increase has so far been recorded. The low potential direct emissions of these elements, resulting from their absolute low production levels, make it unlikely that the increasing use of these elements in modern technology has any noticeable effect on their environmental concentrations on a global scale. This holds particularly true for those of these elements that are probably emitted in relatively high amounts from other human activities (i.e., coal combustion and non-ferrous smelting), such as In, the most studied element of the group.

Intracellular amorphous carbonates uncover a new biomineralization process in eukaryotes.

Until now, descriptions of intracellular biomineralization of amorphous inclusions involving alkaline-earth metal (AEM) carbonates other than calcium have been confined exclusively to cyanobacteria (Couradeau et al., 2012). Here, we report the first evidence of the presence of intracellular amorphous granules of AEM carbonates (calcium, strontium, and barium) in unicellular eukaryotes. These inclusions, which we have named micropearls, show concentric and oscillatory zoning on a nanometric scale. They are widespread in certain eukaryote phytoplankters of Lake Geneva (Switzerland) and represent a previously unknown type of non-skeletal biomineralization, revealing an unexpected pathway in the geochemical cycle of AEMs. We have identified Tetraselmis cf. cordiformis (Chlorophyta, Prasinophyceae) as being responsible for the formation of one micropearl type containing strontium ([Ca,Sr]CO3 ), which we also found in a cultured strain of Tetraselmis cordiformis. A different flagellated eukaryotic cell forms barium-rich micropearls [(Ca,Ba)CO3 ]. The strontium and barium concentrations of both micropearl types are extremely high compared with the undersaturated water of Lake Geneva (the Ba/Ca ratio of the micropearls is up to 800,000 times higher than in the water). This can only be explained by a high biological pre-concentration of these elements. The particular characteristics of the micropearls, along with the presence of organic sulfur-containing compounds-associated with and surrounding the micropearls-strongly suggest the existence of a yet-unreported intracellular biomineralization pathway in eukaryotic micro-organisms.

Temporal evolution of organic carbon concentrations in Swiss lakes: trends of allochthonous and autochthonous organic carbon.

Evaluation of time series of organic carbon (OC) concentrations in lakes is useful for monitoring some of the effects of global change on lakes and their catchments. Isolating the evolution of autochthonous and allochthonous lake OC might be a useful way to differentiate between drivers of soil and photosynthetic OC related changes. However, there are no temporal series for autochthonous and allochthonous lake OC. In this study, a new approach has been developed to construct time series of these two categories of OC from existing dissolved organic carbon (DOC) data. First, temporal series (longer than ten years) of OC have been compiled for seven big Swiss lakes and another 27 smaller ones and evaluated by using appropriate non-parametric statistical methods. Subsequently, the new approach has been applied to construct time series of autochthonous and allochthonous lake OC in the seven big lakes. Doing this was possible because long term series of DOC concentrations at different depths are available for these lakes. Organic carbon concentrations generally increase in big lakes and decrease in smaller ones, although only in some cases are these trends statistically significant. The magnitude of the observed changes is generally small in big lakes (<1% annual change) and larger in smaller lakes. Autochthonous DOC concentrations in big lakes increase or decrease depending on the lake and the station but allochthonous DOC concentrations generally increase. This pattern is consistent with an increase in the OC input from the lakes' catchments and/or an increase in the refractoriness of the OC in question, and with a temporal evolution of autochthonous DOC depending on the degree of recovery from past eutrophication of each particular lake. In small lakes, OC dynamics are mainly driven by decreasing biological productivity, which in many, but not all cases, outweighs the probable increase of allochthonous OC.

Temporal trends in organic carbon content in the main Swiss rivers, 1974-2010.

Increases in dissolved organic carbon (DOC) concentrations have often been reported in rivers and lakes of the Northern Hemisphere over the last few decades. High-quality organic carbon (OC) concentration data have been used to study the change in DOC and total (TOC) organic carbon concentrations in the main rivers of Switzerland (Rhône, Rhine, Thur and Aar) between 1974 and 2010. These rivers are characterized by high discharge regimes (due to their Alpine origin) and by running in populated areas. Small long term trends (a general statistically significant decrease in TOC and a less clear increase in DOC concentrations), on the order of 1% of mean OC concentration per year, have been observed. An upward trend before 1999 reversed direction to a more marked downward trend from 1999 to 2010. Of the potential causes of OC temporal variation analysed (water temperature, dissolved reactive phosphorus and river discharge), only discharge explains a significant, albeit still small, part of TOC variability (8-31%), while accounting for barely 2.5% of DOC variability. Estimated anthropogenic TOC and DOC loads (treated sewage) to the rivers could account for a maximum of 4-20% of the temporal trends. Such low predictability is a good example of the limitations faced when studying causality and drivers behind small variations in complex systems. River export of OC from Switzerland has decreased significantly over the period. Since about 5.5% of estimated NEP of Switzerland is exported by the rivers, riverine OC fluxes should be taken into account in a detailed carbon budget of the country.

COST action TD1407: network on technology-critical elements (NOTICE)--from environmental processes to human health threats.

The current socio-economic, environmental and public health challenges that countries are facing clearly need common-defined strategies to inform and support our transition to a sustainable economy. Here, the technology-critical elements (which includes Ga, Ge, In, Te, Nb, Ta, Tl, the Platinum Group Elements and most of the rare-earth elements) are of great relevance in the development of emerging key technologies-including renewable energy, energy efficiency, electronics or the aerospace industry. In this context, the increasing use of technology-critical elements (TCEs) and associated environmental impacts (from mining to end-of-life waste products) is not restricted to a national level but covers most likely a global scale. Accordingly, the European COST Action TD1407: Network on Technology-Critical Elements (NOTICE)-from environmental processes to human health threats, has an overall objective for creating a network of scientists and practitioners interested in TCEs, from the evaluation of their environmental processes to understanding potential human health threats, with the aim of defining the current state of knowledge and gaps, proposing priority research lines/activities and acting as a platform for new collaborations and joint research projects. The Action is focused on three major scientific areas: (i) analytical chemistry, (ii) environmental biogeochemistry and (iii) human exposure and (eco)-toxicology.

Lead (II)-dithiothreitol equilibria and their potential influence on lead inhibition of 5-aminolevulinic acid dehydratase in in vitro assays.

Dithiothreitol (threo-2,3-dihydroxy-1,4-dithiobutane = DTT) has recently been used to activate 5-aminolevulinic acid dehydratase in kinetic studies for the inhibition of this zinc enzyme by lead. Since the DTT molecule contains donor groups capable of forming metal ion complexes, its presence in the experimental medium used for this kind of assay may largely influence the concentration of lead available for the active sites of the enzyme. Before any quantitative investigation of this phenomenon can be contemplated, all possible complexes formed by lead with DTT must first be identified and their stabilities determined. Accordingly, formation equilibria of DTT complexes with lead(II) have been investigated under physiological conditions (37 degrees C, NaCl, 0.15 mol. dm-3 using glass electrode potentiometry. Corresponding stability constants were refined with MINIQUAD and ESTA computer programs. DTT log protonation constants have been found equal to 9.811 +/- 0.002 and 18.672 +/- 0.002. The following lead-dithiothreitol complexes have been characterized: ML (12.243 +/- 0.063), MLH-1 (2.391 +/- 0.061), M2LH-1 (13.285 +/- 0.059), and M4L3 (51.668 +/- 0.157). Appropriate computer simulations show that the interactions of the two reactants are indeed most significant under the pH and concentration conditions used in the above mentioned biological investigations. In particular, the influence of lead(II)-DTT equilibria on the free concentration of lead available for the active sites of the enzyme is described.

Aluminum speciation studies in biological fluids. Part 3. Quantitative investigation of aluminum-phosphate complexes and assessment of their potential significance in vivo.

Following the discovery that specific health disorders affecting patients with renal disease were due to their excessive body accumulation of aluminum, it was established that aluminum toxicity was mainly due to the ingestion of aluminum-containing phosphate binders. Suspicion of toxicity was thus cast on aluminum-containing antacids, and subsequent tests held on healthy subjects did reveal that aluminum hydroxide gels were also potential oral sources of aluminum, especially in the presence of citric acid. Nevertheless, authors of these tests concluded that there was only marginal absorption of aluminum phosphate. In contrast with these clinical conclusions, it has recently been contended on theoretical grounds that aluminum phosphate represents a serious health hazard. To help elucidate this issue, this paper first deals with a quantitative investigation of aluminum-phosphate equilibria under physiological conditions. Then appropriate computer simulations based on corresponding results are used to assess the actual extent to which phosphate can influence aluminum bioavailability. These simulations confirm that aluminum phosphate is not expected to induce absorption of high amounts of aluminum when administered by itself. Nevertheless, this result may no longer apply in the presence of food, whose various acidic components are likely to modify the involved chemical equilibria. Moreover, it is shown that rising blood plasma phosphate levels should tend to increase aluminum tissue penetration and hence favor its potential toxicity.

Quantitative investigation of copper(II) and zinc(II) complexes with S-carboxymethyl-L-cysteine and computer-simulated appraisal of their potential significance in vivo.

S-carboxymethyl-L-cysteine (SCC) is a mucolytic agent extensively used in the treatment of respiratory tract disorders. Some of the undesirable side effects observed during SCC therapy being reminiscent of symptoms characteristic of copper and zinc imbalances, the objective of this paper was to test the possible interference of SCC with the metabolism of these two metals. Copper(II)- and zinc(II)-SCC complex equilibria have thus been investigated under physiological conditions by means of classical potentiometry combined with computer-assisted calculation techniques. Formation constants derived from these studies have then been used to simulate 1) the potential influence of SCC on the distribution of the above metals in blood plasma and 2) the extent to which gastrointestinal interactions between the drug and each metal ion in turn are likely to affect the bioavailability of each other. The results of these simulations show that 1) plasma therapeutic levels of SCC are not likely to induce dramatic changes in the distributions of copper(II) and zinc(II) low molecular weight fractions, 2) the gastrointestinal distribution of the drug is not affected by standard dietary doses of these metals, and 3) in contrast, therapeutic concentrations of SCC are capable of mobilizing significant fractions of both metals into tissue-diffusible electrically neutral complexes. In conclusion significant depletions of neither copper nor zinc are to be expected from oral administration of SCC. While the drug may to some extent facilitate the excretion of Cu2+ and Zn2+ ions from blood plasma, its gastrointestinal influence is, on the contrary, favorable to a better absorption of these two metals.

Thallium (I) interactions in biological fluids: a potentiometric investigation of thallium(I) complex equilibria with some sulphur-containing amino acids.

Formation constants for thallium(I) complexes of L-cysteine (CysH2), DL-penicillamine (PenH2), N-acetyl-L-cysteine (AcyH2), and N-acetyl-DL-penicillamine (ApeH2) in aqueous solution have been determined in 150 mmol dm-3 NaCl medium at 37 degrees C by potentiometric titrations using a glass electrode. Glycine has been used as a model for simple amino acids. The experimental data may be explained by the formation of the complexes T1(Cys)-, T1(Cys)H, T1(Pen)-, T1(Pen)H, T1(Acy)-, and T1(Ape)- with log formation constants 3.26, 11.28, 3.60, 12.05, 2.27, and 2.45, respectively. Analysis of the results obtained and comparison of thallium(I) complexing ability with that of dimethyl-thallium(III) seem to indicate that thallium(I) toxicity does not directly stem from its interference with the metabolism of sulphur-containing compounds.

Formation constants for the complexes of 2-mercapto-3-phenylpropanoate with nickel(II) and hydrogen ions.

The system formed by 2-mercapto-3-phenylpropanoate (MPP), nickel(II) and hydrogen ions in 30% (v/v) ethanol-water at 25 degrees and I = 100mM (nitrate) has been characterized by means of glass-electrode potentiometry. Protonation constants for 2-mercapto-3-phenylpropanoate and formation constants for the complexes Ni(3)(MPP)(2-)(4) and Ni(MPP)(2-)(2) are reported.

Heterogeneity and liability of Pb(II) complexation by humic substances: practical interpretation tools.

The complexation of Pb(II) by natural organic matter (NOM) is better described by taking into account the dependence of the strength of binding on metal loading conditions. The utility of a linear differential equilibrium function for interpretation of metal ion binding data is demonstrated. This approach considers the binding intensity (log K*) as a function of metal ion loading (theta = bound metal/binding site concentration). Three methods for calculating this function are presented: -direct calculation from metal titration curves, -direct calculation from polarograms, and -compilation of data derived from interpretation of complexation in terms of one- or two- binding sites (e.g. Scatchard analysis), i.e. Cc (complexation capacity = effective site concentration)-K pairs. Heterogeneity also impacts on the apparent lability of complexes; complexes formed at the lowest metal loadings are the least labile.

Can N-acetyl-L-cysteine affect zinc metabolism when used as a paracetamol antidote?

N-Acetyl-L-cysteine (NAC) has long been used in the treatment of chronic lung diseases. Inhalation and oral administration of the drug are both effective in reducing mucus viscosity. In addition, NAC oral therapy allows to restore normal mucoprotein secretion in the long term. Although displaying heavy metal-complexing potential, NAC exerts no detectable influence on the metabolism of essential trace metals when used in the above context (i.e. at doses near 600 mg day-1). However, this may no longer be the case when NAC is used as an oxygen radical scavenger, like in the treatment of paracetamol poisoning. In the latter case, intravenous doses as high as 20 g day-1 are administered, which may induce excessive zinc urinary excretion. In order to allow a better appreciation of the risk of zinc depletion during NAC therapy, the present work addresses the role of this drug towards zinc metabolism at the molecular level. First, formation constants for zinc-NAC complexes have been determined under physiological conditions. Then, computer simulations for blood plasma and gastrointestinal fluid have been run to assess the influence of NAC and its metabolites (e.g. cysteine and glutathione) on zinc excretion and absorption. Blood plasma simulations reveal that NAC can effectively mobilise an important fraction of zinc into urinary excretable complexes as from concentrations of 10(-3) mol dm-3 (which corresponds to a dose of about 800 mg). This effect can still be enhanced by the action of NAC metabolites, among which cysteine is the most powerful zinc sequestering agent. In contrast, simulations relative to gastrointestinal conditions suggest that NAC should tend to increase zinc absorption, regardless of its dose.

Obtaining the 'best values' of stability constants: the protonation constants of five thioether carboxylates as a case study.

Computer speciation models often require large numbers of equilibrium constant values. For this purpose, state-of-the-art methods for experimental constant determination, best value constant selection from published values, and constant prediction based on quantitative structure-activity relationships, are evaluated through their application to the study of the protonation constants of five thioether carboxylates in aqueous solution at 37 degrees C and I = 150 mmol dm(-3) (NaCl).