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1.
Am J Obstet Gynecol ; 229(2): 93-100, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37001577

RESUMO

The intrauterine device is one of the most effective forms of contraception. Use of the intrauterine device has increased in the United States over the last 2 decades. Two formulations are commercially available in the United States: the levonorgestrel-releasing intrauterine device and the copper intrauterine device. The levonorgestrel intrauterine device releases progestin, causing endometrial suppression and cervical mucus thickening, whereas the primary mechanism of action of the copper intrauterine device is to create a local inflammatory response to prevent fertilization. Whereas the protective effects of combined hormonal contraception against ovarian and endometrial cancer, and of tubal sterilization against ovarian cancer are generally accepted, less is known about the effects of modern intrauterine devices on the development of gynecologic malignancies. The best evidence for a protective effect of intrauterine device use against cancer incidence pertains to levonorgestrel intrauterine devices and endometrial cancer, although studies suggest that both copper intrauterine devices and levonorgestrel intrauterine devices reduce endometrial cancer risk. This is supported by the proposed dual mechanisms of action including both endometrial suppression and a local inflammatory response. Studies on the relationship between intrauterine device use and ovarian cancer risk show conflicting results, although most data suggest reduced risk of ovarian cancer in intrauterine device users. The proposed biological mechanisms of ovarian cancer reduction (foreign-body inflammatory response, increased pH, antiestrogenic effect, ovulation suppression) vary by type of intrauterine device. Whereas it has been well established that use of copper intrauterine devices confers a lower risk of cervical intraepithelial neoplasms, the effect of levonorgestrel intrauterine device use on cervical cancer remains unclear. Older studies have linked its use to a higher incidence of cervical dysplasia, but more recent literature has found a decrease in cervical cancer with intrauterine device use. Various mechanisms of protection are postulated, including device-related inflammatory response in the endocervical canal and prostaglandin-mediated immunosurveillance. Overall, the available evidence suggests that both levonorgestrel intrauterine devices and copper intrauterine devices reduce gynecologic cancer risk. Whereas there is support for the reduction of endometrial cancer risk with hormonal and copper intrauterine device use, and reduction of cervical cancer risk with copper intrauterine device use, evidence in support of risk reduction with levonorgestrel intrauterine device use for cervical and ovarian cancers is less consistent.


Assuntos
Anticoncepcionais Femininos , Neoplasias do Endométrio , Dispositivos Intrauterinos de Cobre , Dispositivos Intrauterinos Medicados , Neoplasias Ovarianas , Neoplasias do Colo do Útero , Feminino , Humanos , Colo do Útero , Anticoncepcionais Femininos/uso terapêutico , Neoplasias do Endométrio/epidemiologia , Dispositivos Intrauterinos de Cobre/efeitos adversos , Dispositivos Intrauterinos Medicados/efeitos adversos , Levanogestrel/uso terapêutico , Levanogestrel/farmacologia , Neoplasias Ovarianas/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/prevenção & controle
2.
Am J Obstet Gynecol ; 226(3): 417-419, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34774522

RESUMO

Cesarean scar pregnancies confer serious risk and severe morbidity. Appropriate management is the key to preventing complications. Although expectant management is usually contraindicated, the ideal combination of medical or surgical treatments is unclear and must be tailored to the patient's preferences and stability, provider skill, and the available resources. In this article, we present a combined medical and surgical approach that was successfully employed for the termination and excision of a cesarean scar pregnancy at 12 weeks' gestation in a patient desiring uterine preservation. A video is included, demonstrating the surgical steps of a laparoscopic approach used to safely resect the pregnancy and cesarean delivery scar with minimal blood loss. The management technique described can be utilized to effectively resolve cesarean scar pregnancy, to possibly decrease the risk of recurrence, and preserve future fertility with a minimally invasive outpatient surgery.


Assuntos
Laparoscopia , Gravidez Ectópica , Cesárea/efeitos adversos , Cicatriz/etiologia , Feminino , Humanos , Laparoscopia/métodos , Gravidez , Gravidez Ectópica/etiologia , Gravidez Ectópica/cirurgia , Útero/patologia
3.
Chemosphere ; 228: 565-576, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31055071

RESUMO

Biochar has been promoted as a soil amendment that enhances soil quality and agronomic productivity and reduces greenhouse gas production. However, these benefits are not always realized. A major hurdle to the beneficial use of biochar is our limited knowledge regarding the mechanisms directing its effects on soil systems. This project aimed to eliminate some of this uncertainty by examining the biological responses (plant productivity, greenhouse gas production, soil microbial community structure) of a suite of soils (10) to the addition of biochars produced by different processes (pyrolysis, gasification, burning) from a range of feedstocks (corn stalks, hardwood, grass). Results indicated that these three responses were not significantly impacted by the addition of pyrolysis biochars from different feedstocks at 1 and 5% (w/w) addition levels. On the other hand, both an open-air burned corn stalk (5%) and raw corn stalks (1 and 5%) additions did alter the measured soil functionality. For example, the 5% burnt corn stalks addition reduced total above ground plant biomass (∼30%), increased observed N2O production by an order of magnitude, and altered soil bacterial community structure. The bacterial groups that increased in relative abundance in the burnt corn stalks-amended soils included families associated with cellulose decomposition (Chitinophagaceae), plant pathogens (Xanthomonadaceae), and biochar/charcoal-amended media (Gemmatimonadetes). In contrast, the abundance of these bacterial groups was not impacted by the pyrolysis biochars. Therefore, this research suggests that pyrolysis biochar represents a stabilized form of carbon that is resistant to microbial mineralization and has negligible effects on soil biological responses.


Assuntos
Carvão Vegetal/farmacologia , Germinação/efeitos dos fármacos , Gases de Efeito Estufa , Microbiota/efeitos dos fármacos , Plântula/efeitos dos fármacos , Carbono , Carvão Vegetal/química , Pirólise , Solo/química
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