Drivers of rare earth elements (REEs) and radionuclides in changing subarctic (Nunavik, Canada) surface waters near a mining project.

The emergence of mining projects for rare earth elements (REEs) in response to rising global demand and geopolitical factors introduces environmental concerns, such as the suspected release of anthropogenic REEs to aquatic systems and the coexistence of radionuclides (U, Th). Northern regions confront heightened challenges from limited research and accelerated climate change. Drivers of REEs in surface waters (including George and Koroc rivers, their tributaries, and thermokarst lakes) were studied (2017-2023) in subarctic Canada within a climate transition zone, near a prospective REE mine. Dissolved REEs (<0.45 µm) correlated positively with Al, Fe, Th, U, Cl- and DOC. A novel relationship with water temperature demonstrated an approximate 10-fold decrease in REE concentrations over the environmental gradient (2-20 ℃), suggesting complex implications for REE speciation under climate pressures. Optical analyses further predicted REEs were mobilized by humic-rich, terrestrial DOC, with correlations presenting a possible co-transport with Al, Fe and Th. Relationships for redox-sensitive Ce anomalies (Ce/Ce* = 0.18-1.2) with multi-valent trace metals (Al, Fe, Ti) and DOC were suggestive of a preferential adsorption of Ce by inorganic colloids in low-DOC systems. Findings emphasized the potential for changes in REE geochemistry with ongoing northern surface warming and vegetation shifts.

Etapa de diagnóstico del Cáncer de Próstata ¿Estamos llegando a tiempo? / Prostate cancer stage at diagnosis. Are we running late?

INTRODUCCIÓN: El cáncer de próstata es el segundo cáncer más diagnosticado en hombres en Chile y el mundo. El tamizaje modificó la etapa de diagnóstico, siendo actualmente en EE.UU. un 80 por cinto localizada, 12 por cinto compromiso regional y 4 por ciento metastásico. Tamizaje con APE no está considerado dentro de un programa nacional en Chile. El objetivo de este estudio es caracterizar a la población diagnosticada de cáncer de próstata en un Hospital público en Chile. MATERIALES Y MÉTODO: Estudio descriptivo, retrospectivo. Se revisaron todas las fichas de los pacientes ingresados al GES por Cáncer de Próstata en el Hospital Carlos Van Buren de Valparaíso desde el año 2014 a 2016. RESULTADOS: Se revisaron 259 fichas y se analizaron 226. Edad promedio fue 70,5 años. 46 por ciento presentó APE sobre 20 ng/dL. 31 por ciento presentó metástasis. 42 por ciento recibió tratamiento paliativo. 57 por ciento se realizó tratamiento curativo, con edad promedio 67,4 años. De estos, 31,8 por ciento a cirugía, 68 por ciento índice Gleason <6 y 90 por ciento APE <20. 68 por ciento a RDT con o sin HT, 44 por ciento índice Gleason <6, 75 por ciento APE <20. DISCUSIÓN: El tamizaje del cáncer de próstata es un tema en discusión. En Chile no hay un programa nacional para realizar APE. Centros de atención primaria con acceso a APE tienen mayor tasa de tamizaje. La etapa al diagnóstico en nuestro centro difiere a las series de países desarrollados, siendo considerablemente superior la etapa metastásica. Esto podría deberse a la poca cobertura para detección temprana. Parece ser necesario implementar un programa nacional con cobertura de tamizaje para cáncer de próstata.(AU)

INTRODUCTION: Prostate cancer is the second most diagnosed cáncer in Chile and the world. Screening modified the stage at diagnosis, beeing now in the US 80 pertcent localized, 12 pertcent with regional compromised and 4 pertcent metastatic. Screening with PSA isn't considerd within a national program in Chile. The objetive of this study is to caracterize men diagnosed with prostate cancer at a public hospital in Chile. MATERIALS AND METHODS: Retrospective and descriptive study. Every patient who entered GES because of prostate cancer at the Carlos Van Buren Hospital from Valparaiso between 2014 and 2016 was review. RESULTS: 259 clinical records were review and 226 analized. Mean age was 70,5 years. 46 pertcent had PSA above 20 ng/dL. 31 % had metástasis. 42 % received paliative treatment. 57 % had curative treatment with a mean age of 67,4 years.From this group 31,8 pertcent surgery with a Gleason index <6 and 90 pertcent PSA <20. 68 pertcent had EBRT with or without HT, 44 pertcent of this group had Gleason index <6 and 75 pertcent PSA <20. DISCUSSION: Prostate cancer screening it's a debated topic. In Chile there's no national program to do a PSA. Primary care centers with acces to PSA have more rate of screening. Stage at diagnosis in our center difers from developed countries series, beeing metastatic stage considerably superior. This could be because of the low screening rate for early diagnosis. It seems necesary to implement a national program for prostate cancer screening.(AU)

Embarazo en pacientes con enterocistoplastía / Pregnancy in patients with enterocystoplasty

Un porcentaje considerable de pacientes que requieren cirugía vesical con intestino corresponden a mujeres en edad fértil. El embarazo y parto en este grupo de pacientes sólo ha sido reportado de forma ocasional. El objetivo del presente trabajo es describir una serie clínica de mujeres que consiguieron gestación y parto, posterior a cirugía de ampliación o derivación vesical con intestino. Revisión retrospectiva de fichas clínicas de 6 mujeres que cursaron con una gestación exitosa, posterior a cirugía de enterocistoplastía. Se consideró: diagnóstico pre operatorio, cirugía realizada, embarazo, tipo de parto y complicaciones. Desde el año 1988 a la fecha, se ha realizado cirugía vesical con intestino en 37 mujeres en edad fértil. Seis de ellas han conseguido embarazo, con siete gestaciones reportadas. Los diagnósticos pre operatorios fueron: tres cistopatías intersticiales, dos vejigas neurogénicas y una hiperactividad idiopática del Detrusor. El tipo de cirugía fue ampliación vesical con intestino detubulizado en cuatro casos y ampliación con cierre de cuello y ostomía continente en dos. Los embarazos fueron: feto único en cinco pacientes y gemelar en una. Las complicaciones más significativas fueron infección del tracto urinario y parto prematuro. El parto correspondió a cesárea en cinco mujeres y parto vaginal en una. Posterior al parto, una paciente requirió revisión de la ostomía por prolapso e incontinencia. Las mujeres en edad fértil que han requerido cirugía vesical con intestino, pueden conseguir un embarazo y parto exitoso con baja incidencia de complicaciones.

Surgical manipulation of the developing chick embryo in ovo after the 4th day of incubation.

Surgical manipulations were performed on the eyes of the developing chick embryo between 6 1/2-12 days of incubation at stages when operations had to be performed through the shell and the extra-embryonic membranes. A sufficient proportion of the embryos survived a postoperative incubation period of 6-10 days to analyse the effects of surgical intervention on development.

Experimental evidence for autonomous action of the periodic albinism (ap) gene within developing retinal pigment cells and melanophores of Xenopus laevis.

Genes which affect pigment elaboration may do so by autonomous action within the developing pigment cells or by way of tissue interactions leading to pigment cell differentiation. The site of action of the periodic albinism (ap) gene was investigated by substituting presumptive neural ectoderm of gastrulae of one genotype with uncommitted ectoderm of different genotype. Retinal pigment cells and melanophores arising from such grafts were found to differentiate according to their own genotype in spite of having spent their entire developmental history in tissues of different genotype. This finding demonstrates autonomous action of the ap gene within pigment cell derivatives and does not support recent proposals that the ap gene is involved in inductive interactions leading to melanogenesis. Experiments in which portions of presumptive dorsal mesoderm, implanted in gastrulae of different genotype, induced secondary pigment cells of host phenotype further support the proposal that the ap effect on pigment cells is not mediated by inductive interactions.

The control of mealanoblast differentiation in the periodic albino mutant of Xenopus.

Studies on the incidence of melanophores in older ventral trunk tissues and in isolated regions of periodic albino embryos of Xenopus suggest that melanin granule formation in mutant melanoblasts depends on an environmental contribution which arises at stage 43 in the endodermal tissues.

An analysis of pigment cell development in the periodic albino mutant of Xenopus.

The periodic al,bino mutant (apap) of Xenopus in which the development of melanophores is impaired, is further reported here to possess an aberrant pattern of iridophore differentiation. The development of mutant and wild-type neural crest explants isolated in vesicles derived from tissues from identical and different genotypes was examined to determine if the mutant effect resides in the pigment cells or is mediated by the environmental tissues. Mutant melanophores and iridophores cultured in either mutant or wild-type tissues exhibited mutant patterns of differentiation. Wild-type pigment cells cultured in both wild-type and mutant tissues exhibited wild-type patterns of differentiation. Hence the mutation affects the capacities of melanoblasts and iridoblasts to differentiate but not the ability of the environmental tissues to support pigment cell differentiation.

Melanoblast-tissue interactions and the development of pigment pattern in Xenopus larvae.

The melanophores of larval Xenopus laevis are disparately distributed on the hypomere in that the upper region (UHT) is densely pigmented, the median region (MHT) is moderately pigmented, and the lower region (LHT) is unpigmented. The roles of the melanoblasts and their tissue environment in determining the melanophore pattern was investigated by heterotopic transplantation of hypomeric tissues, culture of neural crest explants in vesicles derived from hypomeric tissues and radioactive marking of neural crest cells. Somite-situated grafts of UHT, MHT and LHT were found to possess melanophore densities similar to those exhibited by such hypomeric tissues when in their normal situation. The number and distribution of trunk melanophores in 'crestless' second host larvae bearing grafts of UHT, MHT and LHT transferred from the somites of primary host embryos indicated that (a) many melanoblasts entered all transplants during neural crest migration in the primary host: subsequently, a small number of melanoblasts were lost from transplants of UHT, a greater number from transplants of MHT and almost all from transplants of LHT; (b) almost all melanoblasts migrated out from transplants of MHT and LHT and entered the tissues of the 'crestless' host, whereas a considerable number of melanoblasts remained in the transplant when it was formed from UHT. Grafts of UHT placed mid-ventrally in the hypomere failed to exhibit melanophores. Vesicles of (a) UHT + MHT and (b) LHT containing neural crest tissue possessed similar numbers of melanophores. Vesicles of LHT differed from those of UHT + MHT in that melanophores were densely aggregated in the implanted neural tissues. Following radioactive marking of neural crest cells labelled nuclei were found on the dorsal ridges of the somites, the surfaces of the neural tube and notochord and in the mesoderm of the upper hypomere and the fin, but were absent from the lateral surfaces of the somites. These results showed that the melanophore pattern in larval Xenopus depended upon melanoblast-tissue interactions, which influenced the migration, rather than the differentiation, proliferation or destruction, of melanoblasts and suggested that tissue selection by migrating melanoblasts enabled these cells to distribute themselves in embryonic tissues in accordance with a hierarchy of melanoblast-tissue affinities. Melanoblast-tissue affinities appeared to be related to the adhesiveness of mesodermal cells: melanoblast extensibility appeared to facilitate exploration of the surrounding tissues. The formation of pigment pattern in larval Xenopus appeared to depend upon the interaction between the melanoblast population pressure and melanoblast-tissue affinities. The present results and those of other workers on amphibian pigmentation were used to construct a model capable of accounting for species-specific differences in larval amphibian pigment patterns, in terms of interactions between species-specific differences in melanoblast-tissue affinities and melanoblast population pressure.