Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Biol Reprod ; 109(3): 356-366, 2023 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-37427962

RESUMEN

Sperm storage by females after mating for species-dependent periods is used widely among animals with internal fertilization to allow asynchrony between mating and ovulation. Many mammals store sperm in the lower oviduct where specific glycans on oviduct epithelial cells retain sperm to form a reservoir. Binding to oviduct cells suppresses sperm intracellular Ca2+ and increases sperm longevity. We investigated the mechanisms by which a specific oviduct glycan, 3-O-sulfated Lewis X trisaccharide (suLeX), prolongs the lifespan of porcine sperm. Using targeted metabolomics, we found that binding to suLeX diminishes the abundance of 4-hydroxybenzoic acid, the precursor to ubiquinone (also known as Coenzyme Q), 30 min after addition. Ubiquinone functions as an electron acceptor in the electron transport chain (ETC). 3-O-sulfated Lewis X trisaccharide also suppressed the formation of fumarate. A component of the citric acid cycle, fumarate is synthesized by succinate-coenzyme Q reductase, which employs ubiquinone and is also known as Complex II in the ETC. Consistent with the reduced activity of the ETC, the production of harmful reactive oxygen species (ROS) was diminished. The enhanced sperm lifespan in the oviduct may be because of suppressed ROS production because high ROS concentrations have toxic effects on sperm.


Asunto(s)
Longevidad , Ubiquinona , Humanos , Femenino , Masculino , Porcinos , Animales , Especies Reactivas de Oxígeno/metabolismo , Semen/metabolismo , Oviductos , Espermatozoides/metabolismo , Polisacáridos/metabolismo , Trisacáridos/metabolismo , Fumaratos/metabolismo , Mamíferos/metabolismo
2.
bioRxiv ; 2023 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-36712093

RESUMEN

Sperm storage by females after mating for species-dependent periods is used widely among animals with internal fertilization to allow asynchrony between mating and ovulation. Many mammals store sperm in the lower oviduct where specific glycans on epithelial cells retain sperm to form a reservoir. Binding to oviduct cells suppresses sperm intracellular Ca 2+ and increases sperm longevity. We investigated the mechanisms by which a specific oviduct glycan, 3-O-sulfated Lewis X trisaccharide (suLe X ), prolongs the lifespan of porcine sperm. Using targeted metabolomics, we report that binding to suLe X diminishes the abundance of the precursor to ubiquinone and suppresses formation of fumarate, a specific citric acid cycle component, diminishing the activity of the electron transport chain and reducing the production of harmful reactive oxygen species (ROS). The enhanced sperm lifespan in the oviduct may be due to suppressed ROS production as many reports have demonstrated toxic effects of high ROS concentrations on sperm.

3.
F S Rev ; 2(2): 160-168, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36268475

RESUMEN

Albumin, a vital protein in cell culture systems, is derived from whole blood or blood products. The culture of human gametes and developing embryos for assisted reproduction (ART) uses albumin of human origin. Human serum albumin (HSA) is derived from expired blood obtained from blood banks. This blood has been stored in polyvinyl chloride bags made clear and flexible with di-2-ethylhexyl phthalate (DEHP). But DEHP can leach from the bags into stored blood and co-fractionate with HSA during albumin isolation. DEHP and its metabolite mono-ethylhexyl phthalate (MEHP), are known endocrine disruptors that are reported to have negative effects when directly supplemented in media for IVF using gametes from a variety of animals. Therefore, the contamination of ART media with DEHP and MEHP through HSA supplementation may have effects on the outcomes of ART procedures. While the embryology laboratory is strictly monitored to prevent a wide variety of contamination, phthalate contamination of HSA has not been broadly examined. This review outlines the function of HSA in ART procedures and the production of HSA from whole blood. Finally, the review highlights the effects of acute phthalate exposures on gametes during in vitro procedures.

4.
Food Chem Toxicol ; 136: 110979, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31786350

RESUMEN

Equol (EQ) is a prominent microbial metabolite of the soy isoflavone, daidzein, with estrogen-like properties. The major soy isoflavone, genistein (GEN), stimulated growth of estrogen-dependent breast cancer (EDBC) cells in vitro and tumor growth in vivo but EQ did not. To understand possible interactions of EQ and GEN on EDBC, EQ was used with GEN in combination in vitro and in vivo. Effects of EQ, GEN and EQ + GEN were evaluated using MCF-7 and T47D EDBC. Ovariectomized athymic mice were used as a model for in vivo tumor growth. Dietary EQ had no effect on MCF-7 tumor growth and the absence of effect was confirmed using a T47D EDBC in vivo model. EQ alone or in combination with GEN increased EDBC cell proliferation in vitro. EQ alone neither stimulated EDBC tumor growth in vivo at various doses nor suppressed tumor growth induced by dietary GEN. In summary, EQ has similar estrogenic effect as GEN in vitro but does not interact with GEN on EDBC tumor growth. Based on the evidence presented here, dietary EQ is unlikely to have estrogenic effects in vivo.


Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Proliferación Celular/efectos de los fármacos , Equol/uso terapéutico , Genisteína/uso terapéutico , Fitoestrógenos/uso terapéutico , Animales , Neoplasias de la Mama/patología , Línea Celular Tumoral , Suplementos Dietéticos , Femenino , Humanos , Glándulas Mamarias Animales/patología , Ratones Endogámicos BALB C , Ratones Desnudos
5.
J Anat ; 232(3): 515-522, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29205333

RESUMEN

Apical blebbing, a non-classical secretion mechanism, occurs in the mature porcine epididymis as part of its normal function. Proteins secreted by this mechanism contribute to the modification of the sperm plasma membrane during epididymal transit and are thought to contribute to acquisition of fertilizing ability. However, little is known about the regulation of this secretion mechanism in an in vivo model. Previous work demonstrated apical blebbing in the epididymis developed pubertally, suggesting androgens, sperm or other luminal factors regulated this process. Hence, the objective was to evaluate the hypothesized regulation of apical blebbing in the epididymis of pubertal boars by androgens and luminal factors. Androgen receptor blockade (flutamide) and surgical interventions (efferent duct ligation, orchidectomy or transection of the caput epididymis) were used to alter signaling, and the subsequent effects on apical blebbing were evaluated histologically. Apical blebbing was not altered by androgen receptor blockade with flutamide, but was significantly reduced 24 h after efferent duct ligation and after orchidectomy, treatments that eliminated luminal flow from the testis (P < 0.05). Like efferent duct ligation, epididymal transection altered luminal flow without removing the androgen source and significantly reduced the appearance of apical blebbing (P < 0.05). In conclusion, apical blebbing in the porcine epididymis appears to be regulated by luminal factors.


Asunto(s)
Micropartículas Derivadas de Células/metabolismo , Epidídimo/metabolismo , Animales , Masculino , Porcinos
6.
Cancer Prev Res (Phila) ; 3(10): 1342-50, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20724470

RESUMEN

Preclinical and correlative studies suggest reduced breast cancer with higher lignan intake or blood levels. We conducted a pilot study of modulation of risk biomarkers for breast cancer in premenopausal women after administration of the plant lignan secoisolariciresinol given as the diglycoside (SDG). Eligibility criteria included regular menstrual cycles, no oral contraceptives, a >3-fold increase in 5-year risk, and baseline Ki-67 of ≥2% in areas of hyperplasia in breast tissue sampled by random periareolar fine-needle aspiration (RPFNA) during the follicular phase of the menstrual cycle. SDG (50 mg/d) was given for 12 months, followed by repeat RPFNA. The primary end point was change in Ki-67. Secondary end points included change in cytomorphology, mammographic breast density, serum bioavailable estradiol and testosterone insulin-like growth factor-I and IGF-binding protein-3, and plasma lignan levels. Forty-five of 49 eligible women completed the study with excellent compliance (median = 96%) and few serious side effects (4% grade 3). Median plasma enterolactone increased ∼9-fold, and total lignans increased 16-fold. Thirty-six (80%) of the 45 evaluable subjects showed a decrease in Ki-67, from a median of 4% (range, 2-16.8%) to 2% (range, 0-15.2%; P < 0.001, Wilcoxon signed rank test). A decrease from baseline in the proportion of women with atypical cytology (P = 0.035) was also observed. Based on favorable risk biomarker modulation and lack of adverse events, we are initiating a randomized trial of SDG versus placebo in premenopausal women.


Asunto(s)
Mama/efectos de los fármacos , Mama/patología , Butileno Glicoles/farmacología , Antígeno Ki-67/biosíntesis , Lignanos/farmacología , Fitoestrógenos/farmacología , Adulto , Mama/metabolismo , Ensayo de Inmunoadsorción Enzimática , Estradiol/sangre , Femenino , Humanos , Hiperplasia/tratamiento farmacológico , Hiperplasia/metabolismo , Hiperplasia/patología , Inmunohistoquímica , Antígeno Ki-67/efectos de los fármacos , Mamografía , Persona de Mediana Edad , Proyectos Piloto , Premenopausia , Progesterona/sangre , Factores de Riesgo , Testosterona/sangre
7.
Pediatr Crit Care Med ; 8(3): 220-4, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17417129

RESUMEN

OBJECTIVE: There is a paucity of literature evaluating the effects of family member presence during bedside medical rounds in the pediatric intensive care unit. We hypothesized that, when compared with rounds without family members, parental presence during morning medical rounds would increase time spent on rounds, decrease medical team teaching/education, increase staff dissatisfaction, create more stress in family members, and violate patient privacy in our open unit. DESIGN: Prospective, blinded, observational study. SETTING: Academic pediatric intensive care unit with 12 beds. PARTICIPANTS: A total of 105 admissions were studied, 81 family members completed a survey, and 187 medical team staff surveys were completed. INTERVENTIONS: Investigators documented parental presence and time allocated for presentation, teaching, and answering questions. Surveys related to perception of goals, teaching, and privacy of rounds were distributed to participants. MEASUREMENTS: Time spent on rounds, time spent teaching on rounds, and medical staff and family perception of the effects of parental presence on rounds. RESULTS: There was no significant difference between time spent on rounds in the presence or absence of family members (p = NS). There is no significant difference between the time spent teaching by the attending physician in the presence or absence of family members (p = NS). Overall, parents reported that the medical team spent an appropriate amount of time discussing their child and were not upset by this discussion. Parents did not perceive that their own or their child's privacy was violated during rounds. The majority of medical team members reported that the presence of family on rounds was beneficial. CONCLUSIONS: Parental presence on rounds does not seem to interfere with the educational and communication process. Parents report satisfaction with participation in rounds, and privacy violations do not seem to be a concern from their perspective.


Asunto(s)
Educación Médica , Unidades de Cuidado Intensivo Pediátrico , Padres , Confidencialidad , Humanos , Estudios Prospectivos , Método Simple Ciego , Enseñanza , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...