1,721,050 research outputs found
Pentraxina 3 come potenziale marcatore di danno endoteliale in gravidanze complicate da preeclampsia e ritardato accrescimento intrauterino.
Full text linkObjectives: Endothelial dysfunction typical of preeeclampsia (PE) is the result of an excessive maternal inflammatory response to pregnancy. PE can occur alone or together with intrauterine growth restriction (IUGR). We investigated PTX3 in maternal, fetal and placental compartments in complicated pregnancies.
Study design: Maternal blood samples were collected during the III trimester in 53 PE, 43 IUGR and 50 normal pregnancies. Fetal samples were collected from the umbilical vein in 26 PE, 23 IUGR and 26 normal pregnancies at elective cesarean section. PTX3 plasma levels were determined by ELISA. Pattern and site of expression of PTX3 was studied by immunohistochemistry (IHC) on placenta, decidual bed and maternal peritoneum.
Results: PE and IUGR pregnancies showed significantly higher median maternal PTX3 levels vs normal pregnancies (24.8 and 9.9 vs 3.8 ng/ml; p<0.001). IUGR showed significantly lower levels than PE (p<0.001). Severe PE revealed higher levels (33.1 vs 17.1 ng/ml, p<0.001) than mild PE. Severe PE with HELLP presented significantly higher levels. IHC on placenta and decidual bed biopsies showed similar expression in pathologic compared to normal cases. Maternal peritoneum expressed a significantly higher signal in the endothelium of pathological vs normal pregnancies. PTX3 was detected in the fetal circulation with values significantly higher in IUGR thsn in normal fetuses with a trend towards higher values in correlation with IUGR severity.
Conclusions: We report elevated maternal levels of PTX3 in PE and IUGR pregnancies. PTX3 levels correlated to clinical severity of disease with higher PTX3 levels in severe than in mild PE, IUGR without clinical PE were significantly different from both normal and PE pregnancies. PTX3 increase may represent the expression of endothelial systemic damage on the maternal side. Moreover, PTX3 is detected in fetal blood and is significantly incresased in IUGR fetuses likely reflecting endothelial damage
Fetal development after assisted reproduction--a review
No full textDespite the success of assisted reproduction technologies (ART) in allowing conception in couples with infertility problems, a growing body of evidence points to implication of ART on fetal birth weight alterations, fetal malformations, chromosomal aneuploidies and syndromes related to genomic imprinting modifications. Different causes can be accounted for to explain the increased risk of fetal defects. Pregnancies generated by ART differ from spontaneously achieved pregnancies in that gametes and embryos are cultured in vitro, more than one conceptus is transferred into the uterine cavity, and the time of transfer is different to what occurs in normal conditions. Epigenetic reprogramming of gene expression has been advocated in relation to the gamete and embryo manipulation, with a significant role of genomic imprinting in determining changes in fetal growth. Moreover, the maternal environment, with the ovarian hyperstimulation of the beginning of pregnancy, could alter the maternal response to the early phases of trophoblast invasion. There are suggestions that placental weights and placental/fetal weight ratios are increased in these pregnancies resembling the model of maternal undernutrition in the early phases of pregnancy. Therefore concern has also arisen around the possible long term and transgenerational effects of assisted reproduction procedures and studies should be carried out to evaluate these possibilities
Infertility as a cancer risk factor – a review
Full text linkOvarian, endometrial and breast cancers are associated with several risk factors, such as low parity,infertility, early age at menarche, and late age at menopause. Frequently most of these risk factors coexist
in infertile patients and some studies suggested that the different infertility causes can be involved in cancer risk development. In particular case–control and cohort studies investigated the possible role of ovulatory disorders, endometriosis and unexplained infertility in increasing the risk of this disease. Most studies have shown no overall increased risk in invasive ovarian cancer in subfertile patients, although nulliparity has been consistently associated with increased rates of ovarian tumor, in particular with borderline and endometrioid cancers in patients with a history of endometriosis. Different studies
reported that infertile women are not at risk for breast cancer. However, women affected by infertility may be more at risk for endometrial cancer, particularly if affected by ovulatory disorders. Moreover, infertility is now often treated with medical devices that could by themselves modify the hormonal environment and be cofactors in the cellular changes towards cancer development. However, although early studies suggested that infertility medications were associated to increased risk in ovarian cancer, subsequent studies have been mainly reassuring, although suggesting that type and duration of
medical treatment can increase the malignancy risk. An increased risk of endometrial cancer in patients undergoing infertility treatment has been reported,
as expected by the similar structure shared by clomiphene and tamoxiphene. Since breast cancer is widely recognized as having a hormonal etiology, a possible role of fertility medications to promote cancer has been hypothesized. However, many large studies were not able to find an associated risk of breast cancer. In conclusion, nowadays, firm answers about the precise effects of infertility and its treatment on cancer risk are not available but findings are generally reassuring. Further studies about fertility drug treatments on larger populations may offer in the future longer follow-up and more precise data with better
adjustments for confounding factors
Amino acids and mitochondrial biogenesis
No full textMitochondria are sources of energy production through their role in producing adenosine triphosphate for cell metabolism. Defective mitochondrial biogenesis and function play relevant roles in the pathophysiology of relevant diseases, including obesity, diabetes mellitus, myopathies, and neurodegenerative diseases. Their function is the product of synthesis of macromolecules within the mitochondria and import of proteins and lipids synthesized outside the organelles. Both are required for mitochondrial proliferation and may also facilitate the growth of preexisting mitochondria. Recent evidence indicates that these events are regulated in a complex way by several agonists and environmental conditions, through activation of specific signaling pathways and transcription factors. Nitric oxide (NO) appears to be a novel modulator of mitochondrial biogenesis. High levels of NO acutely inhibit cell respiration by binding to cytochrome c oxidase. Conversely, chronic, low-grade increases of NO stimulate mitochondrial biogenesis in diverse cell types. Here, we suggest that some types of nutrients, including specific mixtures of amino acids, may improve mitochondrial biogenesis and energy production in energy-defective conditions by increasing endothelial NO synthase expression
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Counseling e trattamento della PROM pre-termine
Full text linkQuando la rottura spontanea delle membrane avviene prima della 37a settimana di gestazione si parla
di “pre-term premature rupture of membranes” (pPROM). Tale evento si verifica nel 3% di tutte le gravidanze.
La pPROM è gravata da un’elevata incidenza di complicanze materne e/o feto-neonatali, che sono
tanto maggiori tanto più è precoce in termini di epoca gestazionale la rottura delle membrane. Rimane
un’importante causa di mortalità/morbilità perinatale, soprattutto perché associata ad una breve latenza all’espletamento
del parto: 50-60% delle donne con pPROM partorisce entro una settimana dalla rottura delle
membrane. Le complicanze materne sono prevalentemente correlate al rischio infettivo: sviluppo di corioamniosite
ed endometrite post-partum. Fra le complicanze neonatali quella di maggior rilievo è la prematurità,
che si associa a sindrome da distress respiratorio, broncodisplasia, emorragia intraventricolare, enterocolite
necrotizzante e retinopatia del prematuro. Seguono poi le complicanze infettive fetali e neonatali e quelle
specifiche correlate all’oligoidramnios, quali ipoplasia polmonare, comparsa di deformità scheletriche, sofferenza
fetale dovuta al prolasso di funicolo o al distacco di placenta normalmente inserta. La gestione clinica
delle pPROM è strettamente dipendente dall’epoca gestazionale in cui avviene la rottura. Se l’evento si verifica
in epoche molto precoci è d’obbligo una consulenza realistica alla coppia sul possibile outcome neonatale
in termini di mortalità e morbidità. A volte ci si trova a far fronte ad una situazione clinica estremamente
delicata che impone decisioni etiche opinabili. Senza dubbio l’outcome di questi bambini dipende strettamente
dalla struttura ospedaliera in cui avviene il parto, per cui è fondamentale un centro che disponga di
unità di terapia intensiva neonatale
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