22 research outputs found

    Holocene carbon fluxes and palaeoproductivity in aquatic ecosystems: a multiproxy, palaeolimnological approach

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    Inland waters act as an important control on the global carbon cycle. Deep tectonic lakes may provide a key link between short‐term and long‐term carbon cycles as buried carbon is essentially locked away from the atmosphere over geological timescales. Here we investigate Holocene carbon dynamics in one of the world’s most important lake ecosystems, Lake Baikal, Siberia

    Mapping of a novel MEN-like syndrome locus to rat Chromosome 4.

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    Multiple endocrine neoplasia-like syndrome (MENX) is a hereditary cancer syndrome in the rat characterized by inborn cataract and multiple tumors affecting the neuroendocrine system developed within the first year of life. The spectrum of affected organs is intermediate between MEN type 1 (MEN1) and MEN type 2 (MEN2) syndromes in human, but, in contrast to them, MENX is inherited in a recessive fashion. Here we report the mapping of the MENX locus to rat Chromosome (Chr) 4 by a genome-wide linkage analysis. This analysis was done in 41 animals obtained from a (Wistar/Nhg x SDwe) x SDwe interstrain backcross, where SDwe (Sprague-Dawley white eye) indicates the affected animals. The MENX disease locus was ultimately mapped to a similar to22-cM interval on Chr 4 that includes the rat homolog of the human RET proto-oncogene. As activating point mutations of RET are known to be responsible for MEN2 in human, we analyzed several markers located in the proximity of Ret for linkage to the disease phenotype. Our data exclude Ret involvement in MENX and establish that a second gene, playing a role in endocrine tumor formation, lies within the distal. part of rat Chr 4. Although heritable human endocrine tumors are quite rare, sporadic tumors of MEN-affected tissues occur at a much higher frequency, and their pathogenesis is poorly understood. The identification of the MENX gene should contribute to our understanding of the genetic mechanisms of neuroendocrine tissue tumorigenesis and may assist in developing new and more appropriate therapeutic strategies for these diseases

    Transitions between socio-emotional and cognitive vulnerability profiles from early to middle childhood: a population study using multi-agency administrative records

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    Published online: 4 February 2020Adult psychosocial difficulties, including psychiatric disorders, are often preceded by childhood psychosocial vulnerabilities, presenting critical windows of opportunity for preventative intervention. The present study aimed to identify longitudinal patterns (representing transitions between profiles) of childhood socio-emotional and cognitive vulnerability in the general population from early to middle childhood, in relation to key risk factors (e.g. parental mental illness and offending). Data were drawn from the New South Wales Child Development Study, which combines intergenerational multi-agency administrative records with cross-sectional assessments using data linkage methods. We analysed data from childhood assessments of socio-emotional and cognitive functioning at two time points (ages 5-6 and 10-11 years) that were linked with administrative data from government departments of health, child protection, and education for 19,087 children and their parents. Latent profile analyses were used to identify socio-emotional and cognitive profiles at each time point, and latent transition analyses were used to determine the probability and potential moderators of transition between profiles at each age. Three developmental profiles were identified in early childhood, reflecting typically developing, emotionally vulnerable, and cognitively vulnerable children, respectively; two profiles were identified in middle childhood, reflecting typically developing and vulnerable children. Child's sex, child protection services contact, parental mental illness, and parental offending influenced children's transitions between different vulnerability profiles, with the strongest effects for parental mental illness and child protection contact. Early detection of vulnerable children and factors promoting resilience are important steps in directing future health and social policy, and service planning for vulnerable children.Patrycja J. Piotrowska, Tyson Whitten, Stacy Tzoumakis, Kristin R. Laurens, Ilan Katz, Vaughan J. Carr, Felicity Harris, Melissa J. Gree

    Recessive Transmission of a Multiple Endocrine Neoplasia Syndrome in the Rat.

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    We describe a novel hereditary cancer syndrome in the rat that is transmitted by a recessive gene mutation. Animals exhibiting the mutant phenotype develop multiple neuroendocrine malignancies within the first year of life. The endocrine neoplasia is characterized by bilateral adrenal pheochromocytoma, multiple extra-adrenal pheochromocytoma, bilateral medullary thyroid cell neoplasia, bilateral parathyroid hyperplasia, and pituitary adenoma. The appearance of neoplastic disease is preceded by the development of bilateral juvenile cataracts. Although the spectrum of affected tissues is reminiscent of human forms of multiple endocrine neoplasia (MEN), no germ-line mutations were detected in the Ret or Menin genes that are responsible for the dominantly inherited MEN syndromes in humans. Segregation studies in F1 and F2 crosses yielded frequencies of affected animals entirely consistent with a recessive autosomal mode of inheritance. The lack of the phenotype in F1 animals effectively excludes a germ-line tumor suppressor gene mutation as the causal event. The absence of mutation of known MEN genes and the unique constellation of affected tissues, plus the recessive mode of inheritance, lead us to conclude that the mutation of an as yet unknown gene is responsible for this syndrome of inherited neuroendocrine cancer

    Coumestrol and its metabolite in mares' plasma after ingestion of phytoestrogen rich plants : potent endocrine disruptors inducing infertility

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    Articles in International JournalsPhytoestrogens exist in plants that are present in forages fed to horses. They may compete with 17-ÎČ estradiol and influence the estrous cycle. Therefore, the objective was to determine whether coumestrol from clover-mixed pastures is present in mare's plasma after their ingestion (experiment I), and when this phytoestrogen was present in mare's plasma after ingestion (experiment II). The effect of a long-term ingestion of phytoestrogens on estrous cycle disruption was assessed (experiment III; clinical case). Experiment I was carried out in nonpregnant anestrous and cyclic Lusitano mares (n = 14) kept on clover and grass-mixed pastures, and supplemented with concentrate and hay or cereal straw. Blood and feedstuff were obtained from November to March. In experiment II, stabled cyclic Lusitano mares (n = 6) were fed for 14 days with increasing amounts of alfalfa pellets (250 g to 1 kg/day). Sequential blood samples were obtained for 8 hours after feed intake on Day 0 (control) and on Days 13 and 14 (1 kg/day alfalfa pellets). Experiment III mares were fed with a mixture of alfalfa and clover haylage for 5 months (group 1; n = 4) or for 9 months (group 2; n = 12). Estrous cycle was determined on the basis of plasma estradiol (E2), progesterone (P4), and ultrasound (experiment III). Concentrations of phytoestrogen coumestrol and its metabolite methoxycoumestrol were determined by high-performance liquid chromatography coupled with mass spectrometry. Phytoestrogens decreased in pasture from November until March (P < 0.01) (experiment I), but were always detected in mares' plasma. In experiment II, plasma-conjugated forms of coumestrol and methoxycoumestrol were higher on Days 13 and 14 than in control (P < 0.05). The highest concentrations of conjugated form of coumestrol were at 1.5 and 4 hours (P < 0.001), whereas its free forms peaked at 1 and at 3.5 hours after ingestion (P < 0.05). Methoxycoumestrol-conjugated form concentration was the highest at 1.5 and 5 hours (P < 0.001), whereas its free form peaked at 1 hour (P < 0.05) and at 1.5 hours (P < 0.001). Long-term intake of coumestrol caused lack of ovulation, uterine edema, and uterine fluid accumulation (experiment III). Coumestrol and methoxycoumestrol in both forms were higher in group 2 (while still ingesting haylage) than in group 1, after haylage withdrawal (P < 0.001). These data show that in the mare, coumestrol and its metabolite increase in blood after ingestion of estrogenic plants and can influence reproduction in mares as potent endocrine disruptors
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