Contrasting magma chemistry in the Candelaria IOCG district caused by changing tectonic regimes

Iron oxide-copper-gold (IOCG) deposits are a vital source of copper and critical elements for emerging clean technologies. Andean-type IOCG deposits form in continental arcs undergoing extension, and they have a temporal relationship with magmatism although they do not exhibit a close spatial relation with the causative intrusions. The processes required to form IOCG deposits and their potential connections to iron oxide-apatite (IOA)-type mineralization remain poorly constrained, as well as the characteristics of magmatism linked to both deposit types. Here we combine zircon U-Pb geochronology with zircon trace element geochemistry of intrusive rocks associated with the Candelaria deposit, one of the world's largest IOCG deposits, to unravel distinctive signatures diagnostic of magmatic fertility. Our results reveal a marked transition in the geochemistry of intrusions in the Candelaria district, characterized by changes in the redox state, water content and temperature of magmas over time. The oldest magmatic stage (~ 128-125 Ma), prior to the formation of the Candelaria deposit, was characterized by zircon Eu/Eu* ratios of 0.20-0.42, and redox conditions of ΔFMQ - 0.4 to + 1.0. The earliest magmatic stage related to the formation of Fe-rich mineralization at Candelaria (118-115 Ma) exhibits low zircon Eu/Eu* ratios (0.09-0.18), low oxygen fugacity values (ΔFMQ ~- 1.8 to + 0.2) and relatively high crystallization temperatures. In contrast, the youngest stage at ~ 111-108 Ma shows higher zircon Eu/Eu* (~ 0.37-0.69), higher oxygen fugacity values (ΔFMQ ~  + 0.4 to + 1.3) and a decrease in crystallization temperatures, conditions that are favorable for the transport and precipitation of sulfur and chalcophile elements. We conclude that Candelaria was formed through two distinct ore-forming stages: the first associated with a reduced, high temperature, water-poor magma developed under a low tectonic stress, followed by a more oxidized, water-rich, and low temperature magmatic event related to a compressional regime. The first event led to Fe-rich and S-poor IOA-type mineralization, while the second event with geochemical signatures similar to those of porphyry copper systems, generated the Cu- and S-rich mineralization. This late stage overprinted preexisting IOA mineralization resulting in the formation of the giant Candelaria IOCG deposit.

O-309 Surgery versus IVF/ICSI in infertile women with rectosigmoid endometriosis: the FERTILITY-RECTOSIGMOID study

Study question

To compare the live birth rate in infertile patients with rectosigmoid endometriosis treated by surgery or IVF/ICSI.

Summary answer

In infertile women with rectosigmoid endometriosis, IVF/ICSI is associated with a higher live birth rate and a shorter time to conceive than first-line surgery.

What is known already

The choice between surgery and IVF/ICSI is based on several variables including concomitant infertility factors, presence of (sub)occlusive symptoms, preference of patients. Until now, there is no evidence to favor first-line IVF/ICSI or first-line surgery in women affected by rectosigmoid endometriosis wishing to conceive.

Study design, size, duration

This was a prospective patient’s preference study enrolling infertile women with rectosigmoid endometriosis who underwent first-line surgery or IVF/ICSI. Symptoms and fertility outcomes were compared between the two groups.

Participants/materials, setting, methods

Rectosigmoid endometriosis was diagnosed by transvaginal ultrasonography and magnetic resonance enema. All study patients underwent computed tomographic colonography (CTC) to assess the degree of stenosis of the intestinal lumen. Inclusion criteria were infertility; bilateral tubal patency; age < 40 years. Exclusion criteria were history of surgery for endometriosis; previous IVF/ICSI cycles; oocyte donation or vitrified oocyte procedures; poor ovarian reserve; estimated bowel stenosis > 70% at CTC; (sub)occlusive symptoms; oligospermia (sperm count < 15 million/mL).

Main results and the role of chance

Two hundred twenty-nine patients underwent IVF/ICSI. Patients underwent up to 4 IVF/ICSI cycles. Overall, 128 women had a live birth (55.9%; 95% C.I., 49.2%-62.4%). Two bowel sub occlusions occurred during IVF-ICSI. 198 patients underwent surgical treatment of rectosigmoid endometriosis. Nine patients have postoperative complications: four rectovaginal fistula, two anastomotic leakage, two pelvic abscess and one postoperative bleeding. At a median follow-up of 23 months after surgery (range, 12-56 months), 91 women had a live birth (44.9%; 95% C.I., 38.0%-56.1%). The live-birth rate was significantly higher in patients who underwent IVF/ICSI than in those who underwent surgery (p = 0.047). The time to conception that resulted in live birth was significantly shorter in patients who underwent IVF/ICSI (mean ± SD, 11.9 ± 7.6 months) than in those who underwent surgery (18.5 ± 8.1 months; p = 0.037). Six months after surgery or first IVF/ICSI cycle, there was a higher improvement of pain (p < 0.001) and intestinal symptoms (p < 0.001) in women surgically treated. No bowel endometriosis-related complication occurred during pregnancy. There was no difference in perinatal outcomes between the two groups.

Limitations, reasons for caution

The nonrandom allocation to treatments and the relatively small sample sized limits the strength of our results.

Wider implications of the findings

IVF/ICSI is associated with a higher live birth rate and a shorter time to conceive than surgery. The disadvantages of IVF/ICSI are potential endometriosis-related complications during the procedure and persistence of symptoms. Surgery improves symptoms but it has a higher risk of postoperative complications, which may negatively impact spontaneous conception.

Trial registration number

CE Liguria - ID 10766 - n. 394 (Approval: 10/2020)

Trabectedin for the therapy of ovarian cancer

Trabectedin is a marine-derivate antitumor drug with a relevant cytotoxic activity and good safety profile. It has been investigated for the treatment of solid diseases, including ovarian cancer (OC), breast cancer, and soft-tissue sarcoma. In 2009, results from the pivotal trial OVA-301 led the European Medicines Agency (EMA) to the approval of trabectedin in combination with PEGylated liposomal doxorubicin for the treatment of platinum-sensitive recurrent OC; further studies revealed an additional benefit also in the subgroup of patients with partially platinum-sensitive disease and in those with a BRCA-mutated status. Additionally, trabectedin demonstrated to prolong the time interval to the subsequent chemotherapy line. Recently, the improved understanding of the antitumor action exerted by trabectedin paved the way to new investigational trials exploring its combination with targeted therapies.

Relugolix for the treatment of uterine fibroids

Uterine leiomyomas represent the most common form of benign gynecological tumors affecting 20-40% of women during their life. Several therapeutic options are available for treating these patients. The use of medical treatment for myomas has largely grown in the last years, in particular for women who would refuse, postpone or are not candidates for surgery. In the last years, the clinical investigation of gonadotropin-releasing hormone (GnRH) antagonists (GnRH-ants) has emerged. This class of drugs exerts pure competitive antagonistic activity on the GnRH receptor at the pituitary gland, producing an immediate stop in the release of gonadotropins and sex steroids. Relugolix is an orally active nonpeptide GnRH-ant, recently licensed for marketing in Japan for the treatment of symptoms related to uterine myomas. Currently, several phase III clinical trials are ongoing to evaluate this molecule in this setting in the U.S. and Europe.

Elagolix sodium for the treatment of women with moderate to severe endometriosis-associated pain

First-line medical therapies for treating pain associated with endometriosis mainly consist in combined oral contraceptives and progestins. However, some women, having persistence of symptoms, may require further therapeutic options. Among these, gonadotropin-releasing hormone (GnRH) agonists (GnRH-as) have been widely employed in the last 30 years, despite being characterized by an unfavorable safety profile. Currently, new alternative investigational options are being investigated to treat this benign chronic disease. GnRH antagonists (GnRH-ants) are innovative hormonal drugs that do not induce flare-up effects and present also a limited onset of hypoestrogenic symptoms; in fact, their pharmacological mechanism of action, which consists in pure antagonistic activity, differs from that of traditional GnRH-as. In July 2018, the U.S. Food and Drug Administration (FDA) approved elagolix sodium for the management of moderate to severe pain associated with endometriosis, after the drug showed promising efficacy and safety results in previous phase III trials. This monograph aims to provide a complete overview of the pharmacokinetics, clinical efficacy and safety of this GnRH-ant for treat¬ing patients with endometriosis.

Transvaginal sonography with vs without bowel preparation in diagnosis of rectosigmoid endometriosis: prospective study

OBJECTIVES

The primary aim of this study was to compare the diagnostic accuracy of transvaginal sonography (TVS) with vs without bowel preparation (BP) in detecting the presence of rectosigmoid endometriosis. Secondary objectives were to compare the diagnostic accuracy of the two techniques in estimating infiltration of the submucosa, length of the largest rectosigmoid nodules, distance of the nodules from the anal verge and presence of multifocal disease.

METHODS

This was a prospective study of patients with symptoms of pelvic pain for more than 6 months and/or suspicion of endometriosis referred to our institution between October 2016 and April 2018. Participants underwent a first TVS without BP followed by TVS with BP within a time interval of 1 week to 3 months. The examinations were performed independently and blindly by two sonographers. Only patients who underwent laparoscopy within the 6 months following the second ultrasound examination were included. Ultrasound results using the two techniques were compared with surgical and histological findings.

RESULTS

Of the 262 patients included in the study, 118 had rectosigmoid endometriosis confirmed at surgery. There was no significant difference in accuracy between TVS with and that without BP in diagnosing the presence of rectosigmoid endometriosis (93.5% vs 92.3%; P = 0.453). No significant difference was observed in accuracy between TVS with and that without BP in diagnosing submucosal infiltration (88.8% vs 84.6%; P = 0.238) and multifocal disease (97.2% vs 95.2%; P = 0.727) in patients diagnosed sonographically with rectosigmoid endometriosis. The accuracy of TVS with BP was similar to that of TVS without BP in estimating the maximum diameter of the largest nodule (P = 0.644) and the distance between the more caudal rectosigmoid nodule and the anal verge (P = 0.162).

CONCLUSION

BP does not improve the diagnostic performance of TVS in detecting rectosigmoid endometriosis and in assessing characteristics of endometriotic nodules. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Influence of adenomyosis on pregnancy and perinatal outcomes in women with endometriosis

OBJECTIVES

Several studies have investigated the correlation between endometriosis and adverse pregnancy and perinatal outcomes. However, the role of adenomyosis as a risk factor for adverse perinatal outcome in women with endometriosis has yet to be established. The aim of this study was to explore if fetal and maternal outcomes, in particular the incidence of a small-for-gestational-age (SGA) infant, are different in pregnant women with endometriosis only from in those with the concomitant presence of diffuse or focal adenomyosis.

METHODS

This was a retrospective analysis of data collected prospectively during a 3-year period. We included 206 pregnant women with endometriosis: 148 (71.8%) with endometriosis only, 38 (18.4%) with focal adenomyosis and 20 (9.7%) with diffuse adenomyosis. Adenomyosis was diagnosed using ultrasonography and was classified as focal or diffuse. The study included patients who conceived spontaneously or by an assisted reproductive technique. Demographics, ultrasound variables and outcome were compared between women with endometriosis only and those with diffuse and those with focal adenomyosis. Logistic regression analysis was performed to assess the association of variables with SGA at birth in women with diffuse and those with focal adenomyosis.

RESULTS

The three groups were similar in demographic characteristics (age, body mass index, mode of conception). Patients with diffuse adenomyosis compared with those with endometriosis only had significantly lower pregnancy-associated plasma protein A (0.61 vs 0.88 multiple of the median, P < 0.001), higher mean uterine artery pulsatility index in the first (2.23 vs 1.67, P < 0.001) and second (1.30 vs 0.94, P < 0.001) trimesters of pregnancy, and higher incidence of SGA (40% vs 10.8%, P < 0.001). No statistically significant differences were found in patients with focal adenomyosis compared with those with endometriosis only. Logistic regression analysis demonstrated that diffuse adenomyosis (odds ratio = 3.744; 95% CI, 1.158-12.099; P = 0.027) was the only independent risk factor for SGA.

CONCLUSIONS

The presence of diffuse adenomyosis in pregnant women with endometriosis is strongly associated with delivery of a SGA infant. Women with diffuse adenomyosis should be treated as being at high risk of placental dysfunction, and these pregnancies might therefore need closer monitoring. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Photodynamic therapy with 5-aminolaevulinic acid and DNA damage: unravelling roles of p53 and ABCG2

OBJECTIVES

In spite of high sensitivity of A549 cells (p53(+/+) ) to lethal effects of photodynamic therapy with 5-aminolaevulinic acid (5-ALA/PDT), DNA damage was observed only in H1299 cells (p53(-/-) ), suggesting that p53 may exert a protective effect. Studies on human colon adenocarcinoma cell lines HCT-116, and their cognate knockouts for p53, were not entirely consistent with the assumption above. Exploring alternative explanations for such conflicting behaviour, we observed that expression of the ATP-binding cassette G2 (ABCG2), a regulator of cell component efflux, had important effects on PDT-generated DNA injury in PC3 cells (prostate) which are p53(-/-) and positive for ABCG2. Addition of an ABCG2 inhibitor in ABCG2 positive A549 (p53(+/+) ) and PC3 (p53(-/-) ) cells eliminated resistance to DNA damage.

MATERIALS AND METHODS

All cell lines investigated were incubated with 5-ALA and irradiated. Effects of PDT were evaluated assessing residual cell viability, cell-cycle profiles, PpIX localization, comet assay and Western blotting. Identical measurements were made in the presence of ABCG2 inhibitor, in cells expressing the transporter.

RESULTS

Our data show that cell aptitude to defend its DNA from PDT-induced injury was mainly ruled by ABCG2 expression. These findings, while providing helpful information in predicting effectiveness of 5-ALA/PDT, may indicate a way to shift PDT from a palliative to a more effective approach in anti-cancer therapy.

Strabometry precision: intra-examiner repeatability and agreement in measuring the magnitude of the angle of latent binocular ocular deviations (heterophorias or latent strabismus)

BACKGROUND AND PURPOSE

This study was designed to compare heterophoria measurements obtained using the methods: prisms cover test (prism alternate cover test), von Graefe technique, Maddox rod test and modified Thorington test. Given the different methodological features of these tests, our working hypothesis was that these tests would not be interchangeable and repeatability would vary.

METHODS

Horizontal deviation measurements were made at: far distance (six meters) and near distance (40 centimeters) on two occasions in 61 young subjects of mean age 19.7 years (range 18 -32 years), with essentially normal eyes and vision, who were not familiar with the methods used. Statistical repeatability and agreement were determined using the Bland and Altman method.

RESULTS

Repeatability: No difference between the results of the various heterophoria tests was statistically significant. Coefficients of repeatability were always best when the tests were conducted at far, the cover test being the most repeatable. Agreement: Mean differences between absolute values ranged from 1.7 prism diopters to 5.1 prism diopters for measurements at far and from 2.1 prism diopters to 3.4 prism diopters at near.

CONCLUSIONS

The alternating prism cover test was the most repeatable test for measuring latent horizontal deviations. Among the subjective tests, the modified Thorington test was the most repeatable. The low level of agreement observed between the different tests makes their interchangeable use in clinical practice not recommended.

Repeatability intraexaminer and agreement in amplitude of accommodation measurements

BACKGROUND

Clinical measurement of the amplitude of accommodation (AA) provides an indication of maximum accommodative ability. To determine whether there has been a significant change in the AA, it is important to have a good idea of the repeatability of the measurement method used. The aim of the present study was to compare AA measurements made using three different subjective clinical methods: the push-up, push-down, and minus lens techniques. These methods differ in terms of the apparent size of the target, the end point used, or the components of the accommodation response stimulated. Our working hypothesis was that these methods are likely to show different degrees of repeatability such that they should not be used interchangeably.

METHODS

The AA of the right eye was measured on two separate occasions in 61 visually normal subjects of mean age 19.7 years (range 18 to 32). The repeatability of the tests and agreement between them was estimated by the Bland and Altman method. We determined the mean difference (MD) and the 95% limits of agreement for the repeatability study (COR) and for the agreement study (COA).

RESULTS

The COR for the push-up, push-down, and minus lens techniques were +/-4.76, +/-4.00, and +/-2.52D, respectively. Higher values of AA were obtained using the push-up procedure compared to the push-down and minus lens methods. The push-down method also yielded a larger mean AA than the negative-lens method. MD between the three methods were high in clinical terms, always over 1.75D, and the COA differed substantially by at least +/-4.50D. The highest agreement interval was observed when we compared AA measurements made using minus lenses and the push-up method (+/-5.65D).

CONCLUSIONS

The minus lens method exhibited the best repeatability, least MD (-0.08D) and the smallest COR. Agreement between the three techniques was poor.

High AC/A accommodative esotropia strabismus treated with contact lenses: a single case design (N=1) study

BACKGROUND AND PURPOSE

The purpose was to determine the efficacy of two types of contact lenses (spherical disposable and aplanatic) as treatment in a patient with esotropia with a high Accommodative Convergence/Accommodation Ratio (AC/A). Due to the possibility of the appearance of accommodative insufficiency in this kind of patient, (i.e., following many years of bifocal glasses use), the elimination of the plus addition lens is advisable. Nevertheless, in some patients, this change leads to the appearance of a residual angle of esodeviation in near vision. It was expected that monofocal aplanatic contact lenses could achieve, due to their optical characteristics, an accurate and orthotropic binocular alignment, without aggravating an undesirable manifestation of the accommodative insufficiency.

METHODS

An experimental design of a single case (N=1) was used in which the subject acted as his own control. With bifocal glasses the subject displayed stability in his binocular and accommodative system at every distance of vision for the past three years. We compared the efficacy of two different types of hydrophilic contact lenses to control the angle of deviation, both at distance and at near vision.

RESULTS

Neither of the two contact lenses produced the results of stability and the correct binocular alignment that had been achieved with bifocal glasses. This subject experienced a worse manifest esodeviation in distance vision with aplanatic lenses than with the disposable ones.

CONCLUSIONS

These monofocal contact lenses did not create acceptable binocular alignment and stability in a subject with a high AC/A accommodative esotropia.

Transport and dynamics on open quantum graphs

We study the classical limit of quantum mechanics on graphs by introducing a Wigner function for graphs. The classical dynamics is compared to the quantum dynamics obtained from the propagator. In particular, we consider extended open graphs whose classical dynamics generate a diffusion process. The transport properties of the classical system are revealed in the scattering resonances and in the time evolution of the quantum system.

Laplacian growth and diffusion limited aggregation: different universality classes

It had been conjectured that diffusion limited aggregates and Laplacian growth patterns (with small surface tension) are in the same universality class. Using iterated conformal maps we construct a one-parameter family of fractal growth patterns with a continuously varying fractal dimension. This family can be used to bound the dimension of Laplacian growth patterns from below. The bound value is higher than the dimension of diffusion limited aggregates, showing that the two problems belong to two different universality classes.

Classical dynamics on graphs

We consider the classical evolution of a particle on a graph by using a time-continuous Frobenius-Perron operator that generalizes previous propositions. In this way, the relaxation rates as well as the chaotic properties can be defined for the time-continuous classical dynamics on graphs. These properties are given as the zeros of some periodic-orbit zeta functions. We consider in detail the case of infinite periodic graphs where the particle undergoes a diffusion process. The infinite spatial extension is taken into account by Fourier transforms that decompose the observables and probability densities into sectors corresponding to different values of the wave number. The hydrodynamic modes of diffusion are studied by an eigenvalue problem of a Frobenius-Perron operator corresponding to a given sector. The diffusion coefficient is obtained from the hydrodynamic modes of diffusion and has the Green-Kubo form. Moreover, we study finite but large open graphs that converge to the infinite periodic graph when their size goes to infinity. The lifetime of the particle on the open graph is shown to correspond to the lifetime of a system that undergoes a diffusion process before it escapes.

Nonlinear Schrodinger flow in a periodic potential

We report a study of solutions of the defocusing nonlinear Schrodinger equation in a spatially periodic potential. The ground-state solution and the steady flows of the system are studied analytically. Above a critical current, a steady state no longer exists and time-dependent solutions are generated, which are numerically simulated and described.