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1.
Mol Psychiatry ; 2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-38278994

RESUMEN

Neurodevelopmental disorders (NDDs) are polygenic in nature and copy number variants (CNVs) are ideal candidates to study the nature of this polygenic risk. The disruption of striatal circuits is considered a central mechanism in NDDs. The 16p11.2 hemi-deletion (16p11.2 del/+) is one of the most common CNVs associated with NDD, and 16p11.2 del/+ mice show sex-specific striatum-related behavioral phenotypes. However, the critical genes among the 27 genes in the 16p11.2 region that underlie these phenotypes remain unknown. Previously, we applied a novel strategy to identify candidate genes associated with the sex-specific phenotypes of 16p11.2 del/+ mice and highlighted three genes within the deleted region: thousand and one amino acid protein kinase 2 (Taok2), seizure-related 6 homolog-like 2 (Sez6l2), and major vault protein (Mvp). Using CRISPR/Cas9, we generated mice carrying null mutations in Taok2, Sez6l2, and Mvp (3 gene hemi-deletion (3g del/+)). Hemi-deletion of these 3 genes recapitulates sex-specific behavioral alterations in striatum-dependent behavioral tasks observed in 16p11.2 del/+ mice, specifically male-specific hyperactivity and impaired motivation for reward seeking. Moreover, RNAseq analysis revealed that 3g del/+ mice exhibit gene expression changes in the striatum similar to 16p11.2 del/+ mice exclusively in males. Subsequent analysis identified translation dysregulation and/or extracellular signal-regulated kinase signaling as plausible molecular mechanisms underlying male-specific, striatum-dependent behavioral alterations. Interestingly, ribosomal profiling supported the notion of translation dysregulation in both 3g del/+ and 16p11.2 del/+ male mice. However, mice carrying a 4-gene deletion (with an additional deletion of Mapk3) exhibited fewer phenotypic similarities with 16p11.2 del/+ mice. Together, the mutation of 3 genes within the 16p11.2 region phenocopies striatal sex-specific phenotypes of 16p11.2 del/+ mice. These results support the importance of a polygenic approach to study NDDs and underscore that the effects of the large genetic deletions result from complex interactions between multiple candidate genes.

2.
Int J Mol Sci ; 23(20)2022 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-36293482

RESUMEN

Therapeutic activation of mechanoreceptors (MStim) in osteopathy, chiropractic and acupuncture has been in use for hundreds of years with a myriad of positive outcomes. It has been previously shown to modulate the firing rate of neurons in the ventral tegmental area (VTA) and dopamine (DA) release in the nucleus accumbens (NAc), an area of interest in alcohol-use disorder (AUD). In this study, we examined the effects of MStim on VTA GABA neuron firing rate, DA release in the NAc, and behavior during withdrawal from chronic EtOH exposure in a rat model. We demonstrate that concurrent administration of MStim and EtOH significantly reduced adaptations in VTA GABA neurons and DA release in response to a reinstatement dose of EtOH (2.5 g/kg). Behavioral indices of EtOH withdrawal (rearing, open-field crosses, tail stiffness, gait, and anxiety) were substantively ameliorated with concurrent application of MStim. Additionally, MStim significantly increased the overall frequency of ultrasonic vocalizations, suggesting an increased positive affective state.


Asunto(s)
Dopamina , Área Tegmental Ventral , Ratas , Animales , Dopamina/farmacología , Neuronas GABAérgicas , Etanol/farmacología , Núcleo Accumbens
3.
Front Cell Neurosci ; 16: 944243, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35903367

RESUMEN

Dopamine (DA) is a cell-signaling molecule that does not readily cross the blood-brain barrier. Despite this, peripherally administered DA enhances DA levels in the nucleus accumbens and alters DA-related behaviors. This study was designed to investigate whether DA subtype-2 receptors are involved in the enhancement of nucleus accumbens (NAc) DA levels elicited by intravenous DA administration. This was accomplished by using microdialysis in the NAc and extracellular single unit recordings of putative DA neurons in the ventral tegmental area (VTA). Additionally, the reinforcing properties of intravenous DA were investigated using a place conditioning paradigm and the effects of intravenous DA on ultrasonic vocalizations were assessed. Following administration of intravenous dopamine, the firing rate of putative DA neurons in the VTA displayed a biphasic response and DA levels in the nucleus accumbens were enhanced. Pretreatment with domperidone, a peripheral-only DA D2 receptor (D2R) antagonist, reduced intravenous DA mediated increases in VTA DA neuron activity and NAc DA levels. Pretreatment with phentolamine, a peripheral α-adrenergic receptor antagonist, did not alter the effects of IV DA on mesolimbic DA neurotransmission. These results provide evidence for peripheral D2R mediation of the effects of intravenous DA on mesolimbic DA signaling.

4.
Community Ment Health J ; 58(6): 1121-1129, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35059936

RESUMEN

Social determinants are receiving renewed attention as research demonstrates the effects of social factors on individuals' physical and mental health and elucidates the biological and psychological mechanisms underlying those effects. Through spheres of influence from policy and regulation development to direct service provision, state mental health agencies are in a unique position to lead primary and secondary prevention efforts aimed at addressing social determinants with both client-level and structural-level interventions. A survey of social determinants-related activity was sent to the Medical Directors of the state offices of mental health in all 50 states. The survey results suggest consensus among respondents as to the importance of addressing specific social determinants. However, few state mental health agencies have taken on a comprehensive and intentional approach to addressing social determinants as a unique area of activity. Specific activities are reviewed, and implications for future work is discussed.


Asunto(s)
Salud Mental , Determinantes Sociales de la Salud , Humanos , Factores Sociales , Gobierno Estatal , Encuestas y Cuestionarios
5.
Nat Commun ; 12(1): 2875, 2021 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-34001908

RESUMEN

Polymeric drug carriers are widely used for providing temporal and/or spatial control of drug delivery, with corticosteroids being one class of drugs that have benefitted from their use for the treatment of inflammatory-mediated conditions. However, these polymer-based systems often have limited drug-loading capacity, suboptimal release kinetics, and/or promote adverse inflammatory responses. This manuscript investigates and describes a strategy for achieving controlled delivery of corticosteroids, based on a discovery that low molecular weight corticosteroid dimers can be processed into drug delivery implant materials using a broad range of established fabrication methods, without the use of polymers or excipients. These implants undergo surface erosion, achieving tightly controlled and reproducible drug release kinetics in vitro. As an example, when used as ocular implants in rats, a dexamethasone dimer implant is shown to effectively inhibit inflammation induced by lipopolysaccharide. In a rabbit model, dexamethasone dimer intravitreal implants demonstrate predictable pharmacokinetics and significantly extend drug release duration and efficacy (>6 months) compared to a leading commercial polymeric dexamethasone-releasing implant.


Asunto(s)
Corticoesteroides/administración & dosificación , Preparaciones de Acción Retardada/administración & dosificación , Dexametasona/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Corticoesteroides/química , Corticoesteroides/farmacocinética , Animales , Células Cultivadas , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Dexametasona/química , Dexametasona/farmacocinética , Dimerización , Modelos Animales de Enfermedad , Implantes de Medicamentos , Liberación de Fármacos , Polímeros/química , Conejos , Ratas , Uveítis/metabolismo , Uveítis/prevención & control
6.
J Pharm Sci ; 110(6): 2472-2478, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33450219

RESUMEN

Alginate solutions crosslink into microspheres in calcium alginate, enabling the encapsulation and subsequent release of biological macromolecules and drugs. However, release from calcium alginate into PBS is relatively fast because it will decrosslink the gel relatively quickly. In this research, FITC-dextran (MW 10 kDa) was encapsulated in 2% (w/v) calcium alginate microspheres by electrospraying. The resulting microspheres (diameter = 247 ± 13 µm) were then layered with thin polyelectrolyte films of hyaluronic acid (HA) and poly-l-lysine (PLL) to attempt to slow the diffusion of FITC-dextran out of the microspheres and the coating parameters were modified to modulate diffusion and release. Increasing the concentration of FITC-dextran encapsulated in the microspheres resulted in an increase in its release over time into PBS. Crosslinking PLL/HA layers on the microspheres did not decrease the in vitro release rates of encapsulated FITC-dextran into PBS. Increasing the number of layers on the microspheres from 3 to 5 layers significantly decreased the amount of encapsulated FITC-dextran released. However, increasing the number of layers to 7 did not further sustain the release of FITC-dextran, likely because these microspheres collapsed to a smaller size during the coating procedure, resulting in release controlled by both diffusion and swelling. Multiple layers of PLL and HA provided a robust mechanism to sustain and control release of large molecules from calcium alginate.


Asunto(s)
Alginatos , Ácido Hialurónico , Dextranos , Fluoresceína-5-Isotiocianato/análogos & derivados , Microesferas , Polilisina
7.
Eur J Pharm Biopharm ; 158: 313-322, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33259898

RESUMEN

Alginate can be gently crosslinked by calcium into hydrogels and microspheres for the encapsulation and release of proteins and drugs. However, the release is often over short periods unless alginate is also covalently modified or crosslinked. This research aims to sustain the release of encapsulated model drug FITC-dextran by covalently crosslinking alginate with short oligomers DNA because evidence suggests that DNA may also interact with alginate to further increase effective crosslinking. Furthermore, modulating the release of drugs from alginate in response to specific proteins could tailor release profiles to improve patient treatment. This research develops a DNA-crosslinked alginate hydrogel and layered alginate microspheres to encapsulate and then sustain the release FITC-dextran (model drug). An aptamer sequence to hen egg-white lysozyme is included in one DNA strand to allow for the disruption of the crosslinks by interactions with human lysozyme. Alginate was covalently modified with complementary strands of DNA to crosslink the alginate into hydrogels, which had increased crosslinking density when re-swollen (in comparison to controls crosslinked with PEG) and could sustained the release of encapsulated FITC-dextran. When an aptamer sequence for hen lysozyme was included in the DNA crosslinks, the hydrogels decrosslinked when incubated in human lysozyme for 60 days. In addition, calcium alginate microspheres were coated with 3 alternating layers of poly-Lysine, DNA-crosslinked alginate, and poly-L-lysine. FITC-dextran loaded into the microspheres released in a sustained manner past 30 days (into PBS at 37 °C) and would likely continue to release for far longer had the studies continued. When incubated with 3 µM of human lysozyme, a burst release of FITC-dextran occurred from both the hydrogels and microspheres, with no changes in the controls. The increased release was in bursts followed by similar sustained release rates suggesting that the human lysozyme temporarily disrupted the DNA crosslinks which were then re-established or were influenced by interactions between DNA and alginate. Importantly, covalently bound complementary strands of DNA could crosslink the alginate and additional interactions appeared to further sustain the release of encapsulated therapeutics.


Asunto(s)
Dextranos/farmacocinética , Portadores de Fármacos/química , Fluoresceína-5-Isotiocianato/análogos & derivados , Microesferas , Alginatos/química , Aptámeros de Nucleótidos/química , Reactivos de Enlaces Cruzados , ADN/química , Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/farmacocinética , Dextranos/administración & dosificación , Composición de Medicamentos/métodos , Liberación de Fármacos , Fluoresceína-5-Isotiocianato/administración & dosificación , Fluoresceína-5-Isotiocianato/farmacocinética , Hidrogeles/química , Tamaño de la Partícula
8.
Nat Ecol Evol ; 4(10): 1368-1376, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32778751

RESUMEN

Recent reports of dramatic declines in insect abundance suggest grave consequences for global ecosystems and human society. Most evidence comes from Europe, however, leaving uncertainty about insect population trends worldwide. We used >5,300 time series for insects and other arthropods, collected over 4-36 years at monitoring sites representing 68 different natural and managed areas, to search for evidence of declines across the United States. Some taxa and sites showed decreases in abundance and diversity while others increased or were unchanged, yielding net abundance and biodiversity trends generally indistinguishable from zero. This lack of overall increase or decline was consistent across arthropod feeding groups and was similar for heavily disturbed versus relatively natural sites. The apparent robustness of US arthropod populations is reassuring. Yet, this result does not diminish the need for continued monitoring and could mask subtler changes in species composition that nonetheless endanger insect-provided ecosystem services.


Asunto(s)
Biodiversidad , Ecosistema , Animales , Europa (Continente) , Humanos , Insectos , Investigación
9.
Toxics ; 8(1)2020 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-31991538

RESUMEN

Beginning in June of 2019, there was a marked increase in reported cases of serious pulmonary injury associated with vaping. The condition, referred to as e-cigarette or vaping product use-associated lung injury (EVALI), does not appear to involve an infectious agent; rather, a chemical adulterant or contaminant in vaping fluids is suspected. In August of 2019, the Wadsworth Center began receiving vaporizer cartridges recovered from patients with EVALI for analysis. Having no a priori information of what might be in the cartridges, we employed untargeted analyses using gas chromatography-mass spectrometry and high-resolution mass spectrometry to identify components of concern. Additionally, we employed targeted analyses used for New York medical marijuana products. Here, we report on the analyses of 38 samples from the first 10 New York cases of EVALI for which we obtained cartridges. The illicit fluids had relatively low cannabinoid content, sometimes with unusual Δ9-/Δ8-tetrahydrocannabinol ratios, sometimes containing pesticides and many containing diluents. A notable diluent was α-tocopheryl acetate (vitamin E acetate; VEA), which was found in 64% of the cannabinoid-containing fluids. To investigate potential sources of the VEA, we analyzed six commercial cannabis-oil diluents/thickeners. Three were found to be >95% VEA, two were found to be primarily squalane, and one was primarily α-bisabolol. The cause(s) of EVALI is unknown. VEA and squalane are components of some personal care products; however, there is growing concern that vaping large amounts of these compounds is not safe.

10.
J Pediatr Nurs ; 33: 83-87, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28209260

RESUMEN

The Pasero Opioid-induced Sedation Scale (POSS) is a valid, reliable tool used to assess sedation when administering opioid medications to manage pain. The POSS is endorsed by The Joint Commission and the American Society for Pain Management Nursing to help prevent adverse opioid-related respiratory events. Although the POSS is used to assess sedation in pediatric patients at some hospitals, prior to this study, it was not formally evaluated in the pediatric population. This study used a quasi-experimental design with a convenience sample of pediatric patients admitted to a large regional medical center in southeastern North Carolina. The POSS was evaluated from three perspectives. First, the study was designed to compare the documentation of sedation when opioids were administered before (n=25) and after (n=27) implementation of the POSS to assess sedation. Second, the occurrence of respiratory adverse events before and after implementation of the POSS was compared. Third, the appropriateness of using the POSS in the pediatric population was evaluated. When the POSS was used, there was an increase in both the clarity and frequency of documentation when sedation was assessed. There was no incidence of opioid-related adverse respiratory events after implementation of the POSS. Finally, the POSS was found to be appropriate and safe to use in the pediatric population. Through a survey, the majority of registered nurses who cared for the research subjects evaluated the POSS as easy, appropriate and safe to use with pediatric patients. The nurses also noted using the POSS provided standardized communication among staff regarding patients' levels of sedation. No adverse effects, concerns, or objections were reported. Coincidentally, while it was not part of the study, frequency of documentation of assessment of pain also improved with implementation of the POSS.


Asunto(s)
Analgésicos Opioides/administración & dosificación , Periodo de Recuperación de la Anestesia , Sedación Consciente/métodos , Manejo del Dolor/métodos , Insuficiencia Respiratoria/inducido químicamente , Adolescente , Factores de Edad , Analgésicos Opioides/efectos adversos , Distribución de Chi-Cuadrado , Niño , Preescolar , Estudios de Cohortes , Sedación Consciente/efectos adversos , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Evaluación de Resultado en la Atención de Salud , Manejo del Dolor/efectos adversos , Insuficiencia Respiratoria/prevención & control , Estudios Retrospectivos , Medición de Riesgo , Poblaciones Vulnerables
11.
J Microbiol Methods ; 126: 54-9, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27196637

RESUMEN

Cyanobacteria are currently being engineered to photosynthetically produce next-generation biofuels and high-value chemicals. Many of these chemicals are highly toxic to cyanobacteria, thus strains with increased tolerance need to be developed. The volatility of these chemicals may necessitate that experiments be conducted in a sealed environment to maintain chemical concentrations. Therefore, carbon sources such as NaHCO3 must be used for supporting cyanobacterial growth instead of CO2 sparging. The primary goal of this study was to determine the optimal initial concentration of NaHCO3 for use in growth trials, as well as if daily supplementation of NaHCO3 would allow for increased growth. The secondary goal was to determine the most accurate method to assess growth of Anabaena sp. PCC 7120 in a sealed environment with low biomass titers and small sample volumes. An initial concentration of 0.5g/L NaHCO3 was found to be optimal for cyanobacteria growth, and fed-batch additions of NaHCO3 marginally improved growth. A separate study determined that a sealed test tube environment is necessary to maintain stable titers of volatile chemicals in solution. This study also showed that a SYTO® 9 fluorescence-based assay for cell viability was superior for monitoring filamentous cyanobacterial growth compared to absorbance, chlorophyll α (chl a) content, and biomass content due to its accuracy, small sampling size (100µL), and high throughput capabilities. Therefore, in future chemical inhibition trials, it is recommended that 0.5g/L NaHCO3 is used as the carbon source, and that culture viability is monitored via the SYTO® 9 fluorescence-based assay that requires minimum sample size.


Asunto(s)
Cianobacterias/crecimiento & desarrollo , Bicarbonato de Sodio/farmacología , Técnicas de Cultivo Celular por Lotes , Biomasa , Dióxido de Carbono/análisis , Clorofila , Cianobacterias/química , Cianobacterias/efectos de los fármacos , Ambiente Controlado , Fluorescencia , Viabilidad Microbiana , Fotosíntesis , Compuestos Orgánicos Volátiles
12.
J Neurosci ; 35(30): 10786-98, 2015 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-26224861

RESUMEN

The mammalian cochlea exhibit minimal spontaneous regeneration, and loss of sensory hair cells (HCs) results in permanent hearing loss. In nonmammalian vertebrates, spontaneous HC regeneration occurs through both proliferation and differentiation of surrounding supporting cells (SCs). HC regeneration in postnatal mammalian cochleae in vivo remains limited by the small HC number and subsequent death of regenerated HCs. Here, we describe in vivo generation of 10-fold more new HCs in the mouse cochlea than previously reported, most of which survive to adulthood. We achieved this by combining the expression of a constitutively active form of ß-catenin (a canonical Wnt activator) with ectopic expression of Atoh1 (a HC fate determination factor) in neonatal Lgr5+ cells (the presumed SC and HC progenitors of the postnatal mouse cochlea), and discovered synergistic increases in proliferation and differentiation. The new HCs were predominantly located near the endogenous inner HCs, expressed early HC differentiation markers, and were innervated despite incomplete alignment of presynaptic and postsynaptic markers. Surprisingly, genetic tracing revealed that only a subset of Lgr5+ cells that lie medial to the inner HCs respond to this combination, highlighting a previously unknown heterogeneity that exists among Lgr5+ cells. Together, our data indicate that ß-catenin and Atoh1 mediate synergistic effects on both proliferation and differentiation of a subset of neonatal cochlear Lgr5+ cells, thus overcoming major limitations of HC regeneration in postnatal mouse cochleae in vivo. These results provide a basis for combinatorial therapeutics for hearing restoration. SIGNIFICANCE STATEMENT: Hearing loss in humans from aging, noise exposure, or ototoxic drugs (i.e., cisplatin or some antibiotics) is permanent and affects every segments of the population, worldwide. However, birds, frog, and fish have the ability to recover hearing, and recent studies have focused on understanding and applying what we have learned from them for restoring hearing in humans. However, studies have been hampered by low efficiency, limited cell numbers, and subsequent death of these newly generated auditory cells. Here, we describe a combinatorial approach, which results in the generation of auditory cells in greater numbers than previously reported, with most of them surviving to adult ages in vivo. These results provide a basis for combinatorial therapeutics for hearing restoration efforts.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Transdiferenciación Celular/fisiología , Células Ciliadas Auditivas Internas/citología , Células Ciliadas Auditivas Internas/metabolismo , beta Catenina/metabolismo , Animales , Animales Recién Nacidos , Proliferación Celular , Supervivencia Celular/fisiología , Técnica del Anticuerpo Fluorescente , Ratones , Ratones Mutantes , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa
13.
Diabetologia ; 58(7): 1587-600, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25899451

RESUMEN

AIMS/HYPOTHESIS: Adipose tissue (AT) distribution is a major determinant of mortality and morbidity in obesity. In mice, intra-abdominal transplantation of subcutaneous AT (SAT) protects against glucose intolerance and insulin resistance (IR), but the underlying mechanisms are not well understood. METHODS: We investigated changes in adipokines, tissue-specific glucose uptake, gene expression and systemic inflammation in male C57BL6/J mice implanted intra-abdominally with either inguinal SAT or epididymal visceral AT (VAT) and fed a high-fat diet (HFD) for up to 17 weeks. RESULTS: Glucose tolerance was improved in mice receiving SAT after 6 weeks, and this was not attributable to differences in adiposity, tissue-specific glucose uptake, or plasma leptin or adiponectin concentrations. Instead, SAT transplantation prevented HFD-induced hepatic triacylglycerol accumulation and normalised the expression of hepatic gluconeogenic enzymes. Grafted fat displayed a significant increase in glucose uptake and unexpectedly, an induction of skeletal muscle-specific gene expression. Mice receiving subcutaneous fat also displayed a marked reduction in the plasma concentrations of several proinflammatory cytokines (TNF-α, IL-17, IL-12p70, monocyte chemoattractant protein-1 [MCP-1] and macrophage inflammatory protein-1ß [ΜIP-1ß]), compared with sham-operated mice. Plasma IL-17 and MIP-1ß concentrations were reduced from as early as 4 weeks after transplantation, and differences in plasma TNF-α and IL-17 concentrations predicted glucose tolerance and insulinaemia in the entire cohort of mice (n = 40). In contrast, mice receiving visceral fat transplants were glucose intolerant, with increased hepatic triacylglycerol content and elevated plasma IL-6 concentrations. CONCLUSIONS/INTERPRETATION: Intra-abdominal transplantation of subcutaneous fat reverses HFD-induced glucose intolerance, hepatic triacylglycerol accumulation and systemic inflammation in mice.


Asunto(s)
Intolerancia a la Glucosa/cirugía , Inflamación/cirugía , Grasa Subcutánea/trasplante , Adipocitos/metabolismo , Adipocitos/ultraestructura , Adiponectina/sangre , Adiposidad , Animales , Composición Corporal , Citocinas/sangre , Dieta Alta en Grasa/efectos adversos , Ingestión de Alimentos , Gluconeogénesis , Glucosa/metabolismo , Insulina/sangre , Leptina/sangre , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Triglicéridos/metabolismo
14.
Astrobiology ; 8(2): 242-52, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18393690

RESUMEN

Materials blasted into space from the surface of early Earth may preserve a unique record of our planet's early surface environment. Armstrong et al. (2002) pointed out that such materials, in the form of terrestrial meteorites, may exist on the Moon and be of considerable astrobiological interest if biomarkers from early Earth are preserved within them. Here, we report results obtained via the AUTODYN hydrocode to calculate the peak pressures within terrestrial meteorites on the lunar surface to assess their likelihood of surviving the impact. Our results confirm the order-of-magnitude estimates of Armstrong et al. (2002) that substantial survivability is to be expected, especially in the case of relatively low velocity (ca. 2.5 km/s) or oblique (

Asunto(s)
Meteoroides , Luna , Exobiología , Medio Ambiente Extraterrestre
15.
Exp Biol Med (Maywood) ; 232(1): 146-55, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17202595

RESUMEN

Luteinizing hormone-releasing hormone (LHRH) was first isolated in the mammalian hypothalamus and shown to be the primary regulator of the reproductive system through its initiation of pituitary gonadotropin release. Since its discovery, this form of LHRH (LHRH-I) has been shown to be one of many structural variants with a variety of roles in both the brain and peripheral tissues. Enormous interest has been focused on LHRH-I, LHRH-II, and their cognate receptors as targets for designing therapies to treat cancers of the reproductive system. LHRH-I is processed by a zinc metalloendopeptidase EC 3.4.24.15 (EP24.15) that cleaves the hormone at the Tyr(5)-Gly(6) bond. We have previously reported that the autoregulation of LHRH gene expression can also be mediated by its processed peptide, LHRH-(1-5). Given its importance in the brain, we have investigated the role of the specific processed peptide of LHRH-I, LHRH-(1-5), within Ishikawa cells, a human endometrial cell line. Using real-time polymerase chain reaction, we observed that LHRH-(1-5) upregulates LHRH-II mRNA expression in Ishikawa cells but does not exert any influence on LHRH-I mRNA levels. This is in contrast to the effects of LHRH-I, which affects the expression of LHRH-I mRNA. Our findings support a potential role for LHRH-(1-5) as a processed metabolite in the endometrium. Further investigations are needed to determine the role of this processed metabolite and to identify specific pathways involved in LHRH-(1-5) signaling.


Asunto(s)
Endometrio/fisiología , Regulación de la Expresión Génica , Hormona Liberadora de Gonadotropina/análogos & derivados , Fragmentos de Péptidos/fisiología , Línea Celular Tumoral , Femenino , Hormona Liberadora de Gonadotropina/biosíntesis , Hormona Liberadora de Gonadotropina/genética , Hormona Liberadora de Gonadotropina/fisiología , Humanos , Ácido Pirrolidona Carboxílico/análogos & derivados , ARN Mensajero/análisis , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
16.
Brain Res Bull ; 69(4): 447-51, 2006 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-16624676

RESUMEN

A member of the Dbl family of oncoproteins was discovered in breast cancer tissue extracts. This novel protein, designated Brx, contains an estrogen-receptor binding motif and is highly expressed in hormone-responsive breast tissue. Due to its ability to augment ligand-dependent activation of estrogen receptors, we analyzed the expression of Brx in the adult mouse brain and pituitary. Results indicated that Brx was expressed in specific regions of the brain and pituitary. Furthermore, the results indicate that differences exist in both brain and pituitary tissue of male and female mice with greater expression in the female. However, estrogen did not influence Brx expression in ovariectomized mice. The anatomical studies support a role for Brx in its association with the estrogen receptor and that Brx may be involved in neuronal and pituitary function in a sexually dimorphic manner.


Asunto(s)
Encéfalo/efectos de los fármacos , Estradiol/farmacología , Estrógenos/farmacología , Hipófisis/efectos de los fármacos , Proteínas Proto-Oncogénicas/biosíntesis , Animales , Encéfalo/metabolismo , Femenino , Factores de Intercambio de Guanina Nucleótido , Inmunohistoquímica , Masculino , Ratones , Ratones Endogámicos C3H , Hipófisis/anatomía & histología , Hipófisis/metabolismo , Factores Sexuales
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