Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
2.
Curr Biol ; 34(13): 2997-3004.e3, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38876101

RESUMO

Providing outdoor recreational opportunities to people and protecting wildlife are dual goals of many land managers. However, recreation is associated with negative effects on wildlife, ranging from increased stress hormones1,2 to shifts in habitat use3,4,5 to lowered reproductive success.6,7 Noise from recreational activities can be far reaching and have similar negative effects on wildlife, yet the impacts of these auditory encounters are less studied and are often unobservable. We designed a field-based experiment to both isolate and quantify the effects of recreation noise on several mammal species and test the effects of different recreation types and group sizes. Animals entering our sampling arrays triggered cameras to record video and broadcast recreation noise from speakers ∼20 m away. Our design allowed us to observe and classify behaviors of wildlife as they were exposed to acoustic stimuli. We found wildlife were 3.1-4.7 times more likely to flee and were vigilant for 2.2-3.0 times longer upon hearing recreation noise compared with controls (natural sounds and no noise). Wildlife abundance at our sampling arrays was 1.5 times lower the week following recreation noise deployments. Noise from larger groups of vocal hikers and mountain bikers caused the highest probability of fleeing (6-8 times more likely to flee). Elk were the most sensitive species to recreation noise, and large carnivores were the least sensitive. Our findings indicate that recreation noise alone caused anti-predator responses in wildlife, and as outdoor recreation continues to increase in popularity and geographic extent,8,9 noise from recreation may result in degraded or indirect wildlife habitat loss.


Assuntos
Ruído , Recreação , Animais , Ruído/efeitos adversos , Comportamento Animal/fisiologia , Animais Selvagens/fisiologia , Ecossistema
3.
PLoS One ; 11(1): e0141983, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26731652

RESUMO

Increased popularity of recreational activities in natural areas has led to the need to better understand their impacts on wildlife. The majority of research conducted to date has focused on behavioral effects from individual recreations, thus there is a limited understanding of the potential for population-level or cumulative effects. Brown bears (Ursus arctos) are the focus of a growing wildlife viewing industry and are found in habitats frequented by recreationists. Managers face difficult decisions in balancing recreational opportunities with habitat protection for wildlife. Here, we integrate results from empirical studies with expert knowledge to better understand the potential population-level effects of recreational activities on brown bears. We conducted a literature review and Delphi survey of brown bear experts to better understand the frequencies and types of recreations occurring in bear habitats and their potential effects, and to identify management solutions and research needs. We then developed a Bayesian network model that allows managers to estimate the potential effects of recreational management decisions in bear habitats. A higher proportion of individual brown bears in coastal habitats were exposed to recreation, including photography and bear-viewing than bears in interior habitats where camping and hiking were more common. Our results suggest that the primary mechanism by which recreation may impact brown bears is through temporal and spatial displacement with associated increases in energetic costs and declines in nutritional intake. Killings in defense of life and property were found to be minimally associated with recreation in Alaska, but are important considerations in population management. Regulating recreation to occur predictably in space and time and limiting recreation in habitats with concentrated food resources reduces impacts on food intake and may thereby, reduce impacts on reproduction and survival. Our results suggest that decisions managers make about regulating recreational activities in time and space have important consequences for bear populations. The Bayesian network model developed here provides a new tool for managers to balance demands of multiple recreational activities while supporting healthy bear populations.


Assuntos
Recreação , Ursidae , Abate de Animais/legislação & jurisprudência , Abate de Animais/estatística & dados numéricos , Distribuição Animal , Animais , Teorema de Bayes , Comportamento Animal , Conservação dos Recursos Naturais , Técnica Delphi , Ecossistema , Europa (Continente) , Comportamento Alimentar , Feminino , Abastecimento de Alimentos , Humanos , Masculino , Desnutrição/etiologia , Desnutrição/veterinária , Modelos Teóricos , América do Norte , Propriedade/legislação & jurisprudência , Recreação/economia , Reprodução , Pesquisa
5.
Gynecol Oncol ; 89(2): 233-5, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12713985

RESUMO

OBJECTIVE: The goal of this study was to determine the clinical implications of a progressively rising serum CA-125 level in the normal (< 35 U/ml) range in ovarian cancer patients with complete response to therapy. METHODS: A multi-institutional investigation was undertaken to identify patients with CA-125-producing epithelial ovarian cancers who experienced progressively rising antigen levels in the normal (<35 U/ml) range after completion of therapy. All patients had (1) histologic documentation of epithelial ovarian cancer and (2) complete clinical remission (CR) as defined by negative imaging studies, normal clinical examination, and a normal (<35 U/ml) serum CA-125 value. All patients had serum CA-125 determinations at 1- to 3-month intervals after treatment. A rising serum CA-125 level was defined as a progressive increase in at least three CA-125 values above the coefficient of variation (CV) for the assay. No patient had a known episode of pelvic or gastrointestinal inflammatory disease during the period when the progressive rise in serum CA-125 took place. RESULTS: Eleven patients with rising serum CA-125 levels in the normal range were identified. Original stage of disease was as follows: stage IIA, 1; stage IIIC, 10. Cell type was as follows: endometrioid adenocarcinoma, 4; serous adenocarcinoma, 6; clear cell carcinoma, 1. Of the 11 patients identified, all developed recurrent ovarian cancer. Tumor recurrence was documented either by new lesions appearing on imaging studies (6/11) or by histologic confirmation (5/11). The mean time from CR to recurrence was 21 months (median = 22, range = 12-33). The mean time from the third early rising serum CA 125 value to clinical or radiographic confirmation of recurrence was 189 days (range = 84-518). All recurrences were intraabdominal with the exception of one axillary recurrence. CONCLUSION: In patients with a history of ovarian cancer, three progressively rising serum CA-125 values in the normal range (< 35 U/ml) at 1- to 3-month intervals are associated with a high likelihood of tumor recurrence. Patients with such a pattern should undergo immediate investigation to rule out and/or identify recurrent cancer.


Assuntos
Antígeno Ca-125/sangue , Neoplasias Ovarianas/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Epiteliais/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/imunologia , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/terapia
6.
Gynecol Oncol ; 92(2): 553-8, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14766247

RESUMO

OBJECTIVE: Expression analysis of estrogen receptor-beta (ER-beta) and estrogen receptor-alpha (ER-alpha) in tamoxifen-associated malignant endometrial tumors (TAMET) has not previously been published. Antiestrogens complexed with ER-beta have been reported to result in activation of the activator protein-1 (AP-1) pathway that may result in cell proliferation and tumor growth. In this study, the pathologic features and expression of ER-alpha, ER-beta and progesterone receptor (PR) in TAMET were determined and compared to matched cases of non-tamoxifen-associated endometrial cancers. METHODS: TAMET (n = 33) were evaluated for pathologic features (tumor type, grade, depth of myometrial invasion, lymphvascular space invasion and lymph node status), expression of ER-alpha, ER-beta and PR, and survival data (mean follow-up: 28.7 months). Each case was matched to two control patients with spontaneous endometrial cancers according to tumor type, grade and stage as well as patient age and weight (mean follow-up: 51.5 months). Formalin-fixed paraffin-embedded tissue sections were immunostained with anti-ER-alpha (1D5, Dako, Carpinteria, CA) and anti-PR (PgR636, Dako). Expression scores were determined as a sum of the product of staining intensity and proportion of cells staining (H-score). Deparaffinized sections of tumor were microdissected followed by RNA isolation. Quantification of ER-beta mRNA was performed by real-time quantitative RT-PCR with results expressed as a percentage of beta-actin mRNA. RESULTS: Of the 33 cases 20 were endometrioid (8 grade 1, 10 grade 2, 2 grade 3), 9 papillary serous and 4 malignant mullerian mixed tumors. Using a multivariate conditional regression model, TAMET had lower ER-alpha expression (P = 0.018), higher PR expression (P = 0.029), and more frequent expression of ER-beta (P = 0.032) as compared to control cases. Cases with TAMET had more deaths from cancer and significantly worse survival from disease than controls (P = 0.01 by a log rank test). CONCLUSION: TAMET are characterized by a lower expression of ER-alpha, higher expression of PR and more frequent expression of ER-beta as compared to spontaneous tumors. Differential expression of ER-alpha and ER-beta may alter the expression of key target genes (such as those induced by AP-1-dependent gene transcription), and contribute to the pathogenesis and clinical behavior of these tumors. Survival from disease was significantly worse for cases with TAMET as compared to controls.


Assuntos
Antineoplásicos Hormonais/efeitos adversos , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Receptores de Estrogênio/biossíntese , Receptores de Progesterona/biossíntese , Tamoxifeno/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Neoplasias do Endométrio/induzido quimicamente , Receptor alfa de Estrogênio , Receptor beta de Estrogênio , Feminino , Humanos , Pessoa de Meia-Idade
7.
Gynecol Oncol ; 91(1): 9-14, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14529657

RESUMO

OBJECTIVE: Several tumors express the protein product of the protooncogene c-KIT. Some of these respond to imatinib mesylate, a tyrosine kinase inhibitor. The tumors that respond frequently have mutation(s) in exon 11 of c-KIT that encodes for the regulatory juxtamembrane helix. Some tumors that express KIT protein have mutation(s) in exon 17 of c-KIT; however, these do not respond to imatinib mesylate. This investigation was performed to determine the expression of KIT protein and mutational status of exons 11 and 17 of c-KIT in uterine sarcomas. METHODS: Twenty-five uterine sarcomas treated from 1990 to 2002 were evaluated. These included 14 malignant mullerian mixed tumors (MMMT), 7 leiomyosarcomas (LMS), 2 endometrial stromal sarcomas (ESS), and 2 high-grade heterologous sarcomas (HGHS). Formalin-fixed, paraffin-embedded tissue sections were immunostained with anti-KIT antibody (Santa Cruz Biotechnology, Santa Cruz, CA) with a semiquantitative assessment. Normal myometrium when present in the section was used as an internal negative control. Areas of tumor were microdissected followed by DNA extraction, polymerase chain reaction (PCR) amplification of exons 11 and 17, single-strand conformational polymorphism (SSCP), and DNA sequencing to detect the presence of mutation(s). RESULTS: All 25 tumors expressed KIT protein at varying levels as assessed by immunohistochemistry. The staining was diffuse and of moderate to strong intensity in 22 tumors. In three tumors (one of each type except MMMT) the staining intensity was weak. In MMMT the epithelial and sarcomatous foci stained similarly. No mutation(s) in exons 11 or 17 of c-KIT were identified in 24/25 tumors. One LMS had deletion of both exons 11 and 17. CONCLUSIONS: Although uterine sarcomas express KIT protein, they lack KIT-activating mutation(s) in exon 11 or 17 of c-KIT. Therefore, these tumors are unlikely to respond to imatinib mesylate.


Assuntos
Proteínas Proto-Oncogênicas c-kit/biossíntese , Proteínas Proto-Oncogênicas c-kit/genética , Sarcoma/genética , Sarcoma/metabolismo , Neoplasias Uterinas/genética , Neoplasias Uterinas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA de Neoplasias/genética , Éxons/genética , Feminino , Humanos , Imuno-Histoquímica , Leiomiossarcoma/genética , Leiomiossarcoma/metabolismo , Pessoa de Meia-Idade , Tumor Mulleriano Misto/genética , Tumor Mulleriano Misto/metabolismo , Mutação , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Sarcoma/patologia , Sarcoma do Estroma Endometrial/genética , Sarcoma do Estroma Endometrial/metabolismo , Neoplasias Uterinas/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA