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1.
Chaos ; 34(2)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38407397

RESUMEN

A reservoir computer is a machine learning model that can be used to predict the future state(s) of time-dependent processes, e.g., dynamical systems. In practice, data in the form of an input-signal are fed into the reservoir. The trained reservoir is then used to predict the future state of this signal. We develop a new method for not only predicting the future dynamics of the input-signal but also the future dynamics starting at an arbitrary initial condition of a system. The systems we consider are the Lorenz, Rossler, and Thomas systems restricted to their attractors. This method, which creates a global forecast, still uses only a single input-signal to train the reservoir but breaks the signal into many smaller windowed signals. We examine how well this windowed method is able to forecast the dynamics of a system starting at an arbitrary point on a system's attractor and compare this to the standard method without windows. We find that the standard method has almost no ability to forecast anything but the original input-signal while the windowed method can capture the dynamics starting at most points on an attractor with significant accuracy.

3.
J Cell Biol ; 80(2): 444-50, 1979 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-457751

RESUMEN

Unfixed freeze-dried and uncoated tissue sections of the mouse duodenum were suspended across a hole in a carbon planchet and analyzed in a scanning electron microscope fitted with energy-dispersive x-ray analytical equipment. Computer analysis of the x-ray spectra allowed elemental microanalysis of the nucleus, cytoplasm, and late anaphase-early telophase chromatin regions in the cryptal and villus enterocytes. Elemental concentrations (mmol/kg dry wt) were measured for Na, Mg, P, S, Cl, K, and Ca. None of the elements were compartmentalized preferentially in either the nucleus or the cytoplasm of interphase enterocytes of crypts or in postmitotic enterocytes of villi. In contrast, Ca, S, and Cl are detectable in significantly higher concentrations in mitotic chromatin of dividing enterocytes of the crypt as compared to surrounding mitotic cytoplasm, but Na, Mg, and P are in lower concentrations in the mitotic chromatin as compared to mitotic cytoplasm. Interphase enterocytes of crypts have higher concentrations of Mg, P, and K, and lower concentrations of Na than do postmitotic enterocytes of villi.


Asunto(s)
Duodeno/análisis , Elementos Químicos/análisis , Mucosa Intestinal/análisis , Animales , Núcleo Celular/análisis , Citoplasma/análisis , Duodeno/citología , Microanálisis por Sonda Electrónica , Femenino , Mucosa Intestinal/citología , Ratones , Mitosis
4.
Cancer Res ; 43(1): 73-7, 1983 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-6847785

RESUMEN

The effects of amiloride, a reported inhibitor of serum-stimulated sodium influx, were tested on tumor growth, tumor cell proliferation, and intracellular element content of cancer cells in vivo. We have shown previously that cancer cells have high intranuclear levels of sodium compared to those of their normal counterpart cells and have postulated that such a high level of sodium may be involved in the cancer state. We now report that amiloride, when given in a series of injections, inhibited both H6 hepatoma and DMA/J mammary adenocarcinoma growth in vivo in a dose-dependent fashion and that 3 injections of amiloride at a dose of 1.0 microgram/g body weight into mice bearing H6 hepatomas resulted in a significant decrease in the intranuclear content of sodium but not the content of magnesium, phosphorus, sulfur, chlorine, or potassium as measured by electron probe X-ray microanalysis in the H6 hepatoma cells. Amiloride at dosages as low as 1.0 microgram/g body weight per injection also inhibited tumor cell proliferation as measured by the tritated thymidine autoradiography labeling index. Amiloride caused no changes in the mean profile diameters of metaphase or interphase H6 hepatoma or DMA/J mammary adenocarcinoma cells, suggesting that the action of amiloride on tumor growth was not due to cell volume changes. These data show that amiloride both inhibited tumor growth and decreased the proliferation of the tumor cells in the H6 hepatomas which was correlated with a decreased intranuclear sodium content.


Asunto(s)
Amilorida/farmacología , Transformación Celular Neoplásica/efectos de los fármacos , Neoplasias Hepáticas Experimentales/metabolismo , Pirazinas/farmacología , Sodio/metabolismo , Adenocarcinoma/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Masculino , Ratones
5.
Endocrinology ; 116(1): 202-6, 1985 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2856872

RESUMEN

The influence of vasoactive intestinal peptide (VIP), TRH, and dexamethasone (Dex) on PRL mRNA was investigated in PRL-producing GH3 cells using cytoplasmic dot hybridization and RNA blot analysis. Total cytoplasmic RNA was transferred to nitrocellulose filter paper and quantitated by hybridization to PRL recombinant DNA probes labeled with 32P. Incubation of GH3 cells with VIP for 25 h increased the content of cytoplasmic PRL mRNA. This increase was dose dependent, being significant at 2 X 10(-8) M and reaching a maximum at 2 X 10(-7) M. VIP at 2 X 10(-9) M had no effect on cytoplasmic PRL mRNA content. TRH (2 X 10(-7) M) also increased whereas Dex (2 X 10(-7) M) decreased the content of PRL mRNA. The inhibitory effect of Dex (2 X 10(-7) M) on cytoplasmic PRL mRNA was reversed by VIP (2 X 10(-7) M). Changes in medium PRL levels after these various hormone treatments paralleled those changes observed in PRL mRNA content. Examination of total poly(A)+ RNA demonstrated that incubation with VIP (2 X 10(-7) M) for 6 h increased the content of the mature PRL mRNA and its processing intermediates. Dex (2 X 10(-7) M) decreased the content of all species of PRL mRNA. These data suggest that VIP-stimulated PRL release is the result of an increase in the content of PRL mRNA and its precursors.


Asunto(s)
Neoplasias Hipofisarias/metabolismo , Prolactina/metabolismo , ARN Mensajero/metabolismo , Péptido Intestinal Vasoactivo/farmacología , Animales , Línea Celular , Núcleo Celular/metabolismo , ADN Recombinante , Dexametasona/farmacología , Hibridación de Ácido Nucleico , Poli A/metabolismo , Prolactina/genética , Ratas , Hormona Liberadora de Tirotropina/farmacología
6.
Neuropsychologia ; 38(1): 22-31, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10617289

RESUMEN

Healthy subjects were tested in two experiments to examine the effects of lateralized cues on line bisection and landmark judgments. The studies were designed to investigate whether bisection and landmark biases induced by cueing are simply a result of a direct perceptual lengthening of the cued part of the line caused by the fact that the cue is visible, thus creating a composite 'line plus cue' or whether cueing induces an attentional bias operating on judgments of spatial extent by either reducing the magnitude of the parts of the stimulus receiving 'less' attention or magnifying those parts receiving 'more'. Lateralized cues were either visible letter cues or invisible marks drawn with a leadless pencil either by the subject him/herself (Experiment 1) or the experimenter (Experiment 2). Comparable to a previous study (Mattingley, Pierson, Bradshaw, Phillips and Bradshaw, 1993, Neuropsychologia, 31, 1201-1215), the first experiment showed that only visible cues affected line bisection and landmark judgments thus favouring the perceptual explanation. The second study, however, revealed bisection and judgment biases for invisible as well as visible cues with the attended part of the line appearing subjectively longer. These results indicate that attentional modulations can increase the salience of a line in a similar vein to physical changes. It seems likely that the requirement of a motor response in Experiment 1 cancelled out all attentional properties supposedly induced by placing that invisible cue.


Asunto(s)
Envejecimiento/psicología , Atención , Señales (Psicología) , Dominancia Cerebral , Desempeño Psicomotor , Percepción Espacial , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Trastornos de la Percepción/psicología , Valores de Referencia
7.
Semin Reprod Med ; 18(2): 205-18, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11256170

RESUMEN

Over the past decade there has been a resurgence of interest in the culture media used in clinical in vitro fertilization. Unfortunately, during this time more confusion than consensus appears to have developed regarding the composition of these media. In order to facilitate a clearer understanding of this field, it is important to understand the role of specific medium components and how their use is regulated by the embryo. The roles of the key nutrients glucose, pyruvate, lactate, and amino acids during the preimplantation period have therefore been presented. Analysis of how the embryo regulates the utilization of such nutrients has led to a clearer understanding of the embryo's requirements during the dynamic period of preimplantation development. From such information, sequential culture media have been developed along with novel noninvasive tests of embryonic viability. It is proposed that continued studies on the human embryo will lead to further improvements in embryo culture conditions and the optimization of viability assays, culminating in the ability to transfer single embryos for the majority of, if not all patients.


Asunto(s)
Embrión de Mamíferos/fisiología , Desarrollo Embrionario y Fetal , Metabolismo Energético , Fenómenos Fisiológicos de la Nutrición , Aminoácidos , Animales , Medios de Cultivo , Técnicas de Cultivo , Desarrollo Embrionario , Femenino , Glucosa , Hexoquinasa , Humanos , Ácido Láctico , Fosfofructoquinasa-1 , Embarazo , Ácido Pirúvico
8.
Fertil Steril ; 61(4): 714-9, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7512054

RESUMEN

OBJECTIVE: To evaluate both the laboratory and clinical outcomes after IVF-ET using culture media supplemented with a plasma protein fraction (PPF, Plasmatein; Alpha Therapeutics, Los Angeles, CA) containing albumin and significant amounts of alpha- and beta-globulins. DESIGN: One-year clinical trial of a PPF with high globulin content as a medium supplement during IVF, embryo growth, and ET. SETTING: Fertility Center of San Antonio, a private, office-based center for assisted reproduction. PATIENTS: Ninety-eight couples, with women ranging in age from 26 to 46 years, undergoing 103 ovum retrievals for IVF-ET as treatment for infertility because of tubal factor, endometriosis, anovulation, uterine or cervical factor, male factor, and unexplained causes. MAIN OUTCOME MEASURES: Fertilization rate, zygote cleavage rate, clinical pregnancy rate (PR), continuing PRs, and implantation rates. RESULTS: Supplementation with PPF in insemination, growth and transfer medium resulted in a clinical PR of 41.5% per transfer with continuing PRs of 35.2% per retrieval, 37.2% per patient, and 38.7% per transfer. CONCLUSIONS: A PPF containing significant amounts of alpha- and beta-globulins can serve as an effective protein supplement to IVF medium, with outcomes manifested as high continuing PRs. These data indicate a potential role for glycoprotein components of serum in supporting healthy embryo growth in vitro, although the mechanism may relate more to the general physicochemical properties of this fraction than to the actions of a specific component.


Asunto(s)
alfa-Globulinas , beta-Globulinas , Medios de Cultivo , Transferencia de Embrión , Fertilización In Vitro , Adulto , Técnicas de Cultivo , Femenino , Humanos , Persona de Mediana Edad , Embarazo
9.
Fertil Steril ; 63(3): 652-5, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7851601

RESUMEN

OBJECTIVE: To describe a simple injection apparatus and method for performing intracytoplasmic sperm injection in a clinical IVF program. DESIGN: A prospective clinical trial of intracytoplasmic sperm injection. SETTING: A private office-based fertility program. PATIENTS: Five couples undergoing IVF-ET with intracytoplasmic sperm injection as a treatment for male factor infertility. INTERVENTIONS: Intracytoplasmic sperm injection was performed at room temperature (23.5 to 24.5 degrees C) in a simple zwitterion-buffered medium. MAIN OUTCOME MEASURES: Fertilization rates, cleavage rates, clinical pregnancy rates, implantation rates. RESULTS: Intracytoplasmic sperm injection was performed on 44 fresh oocytes from five patients. Twenty-three oocytes fertilized (52.3%) and 22 zygotes cleaved (95.7%). Three of five patients became pregnant (60%), resulting in the live birth of one normal male infant, one continuing singleton pregnancy, and one continuing twin gestation (46XX, 46XY). The implantation rate was 23.5%. CONCLUSION: Intracytoplasmic sperm injection can be performed successfully in a simple medium at room temperature using commercially available microtools.


Asunto(s)
Fertilización In Vitro/instrumentación , Embarazo , Espermatozoides , Citoplasma , Implantación del Embrión , Femenino , Humanos , Masculino , Estudios Prospectivos
10.
Fertil Steril ; 45(3): 403-6, 1986 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3949040

RESUMEN

An improved knowledge of cryopreservation of primate embryos will have important research and clinical application. Fifty-six 4- to 8-cell in vitro fertilized embryos were frozen in HEPES-buffered Tyrode's solution containing 1.5 M dimethylsulfoxide (DMSO) and cooled at the rate of 0.3 degrees C/minute to -39 degrees C before being transferred into liquid nitrogen. Embryos were rapidly thawed at room temperature for 2 minutes. DMSO was diluted with medium in three steps at 5-minute intervals. Of the 56 embryos, 39 (70%) were classified as viable on the basis of surviving the freezing process with greater than 50% of their blastomeres intact. Twelve of the 39 embryos were cultured overnight, and 11 cleaved at least once. Twenty-five embryos were transferred to nine synchronized, unstimulated recipient monkeys 24 to 48 hours after ovulation. Three pregnancies (33.3%) resulted from the nine transfers.


Asunto(s)
Transferencia de Embrión , Conservación de Tejido , Animales , Femenino , Fertilización In Vitro , Congelación , Macaca fascicularis
11.
Fertil Steril ; 54(1): 166-8, 1990 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2358083

RESUMEN

Clinical pregnancies have been initiated by ZIFT using zygotes produced by reinsemination of oocytes with donor sperm ("donor rescue") after an initial 15- to 20-hour exposure to husband's sperm. A total of 54 oocytes from four couples experiencing failed fertilization by husband's sperm were reinseminated with donor sperm, resulting in 38 zygotes (70.4% fertilization). Four zygotes were transferred during ZIFT in each case and resulted in two (50%) continuing pregnancies. Additional zygotes from donor reinsemination were cryopreserved for each couple. Donor rescue expands the utility of ZIFT as a treatment for male factor infertility.


Asunto(s)
Transferencia de Embrión , Fertilización In Vitro , Infertilidad Masculina/terapia , Inseminación Artificial Heteróloga , Inseminación Artificial Homóloga , Inseminación Artificial , Femenino , Humanos , Masculino
12.
Fertil Steril ; 42(5): 791-5, 1984 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-6436074

RESUMEN

We have started an in vitro fertilization program in cynomolgus monkeys in an effort to develop an appropriate animal model to improve our knowledge of early embryonic development. In 16 of 25 animals treated with menopausal gonadotropins, preovulatory follicles developed. Follicular aspiration was performed at laparotomy after human chorionic gonadotropin injection. A total of 299 follicles were aspirated, and 251 oocytes were recovered. Oocytes were cultured in 1 ml of growth medium or 100 microliter droplets of medium under mineral oil. Semen samples were obtained by electroejaculation, and the oocytes were inseminated 4 to 24 hours after aspiration. Culture under mineral oil significantly increased the fertilization and cleavage rates. Of 68 embryos produced, 24 have been used in 10 embryo transfers, resulting in two pregnancies.


Asunto(s)
Transferencia de Embrión/métodos , Fertilización In Vitro/métodos , Macaca fascicularis , Macaca , Animales , Gonadotropina Coriónica/uso terapéutico , Medios de Cultivo , Femenino , Inseminación Artificial/veterinaria , Masculino , Menotropinas/uso terapéutico , Oocitos/crecimiento & desarrollo , Inducción de la Ovulación
13.
Fertil Steril ; 69(2): 329-34, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9496350

RESUMEN

OBJECTIVE: To evaluate clinical outcomes of day 2 versus day 3 ET using a culture media with no glucose or phosphate. DESIGN: Retrospective clinical study. SETTING: Hospital-based fertility clinic. PATIENT(S): One hundred seventy-six IVF-ET patients undergoing controlled ovarian supraovulation. INTERVENTION(S): IVF and delaying the ET by 1 day. MAIN OUTCOME MEASURE(S): Number of blastomeres per embryo, implantation and pregnancy rates. RESULT(S): Delaying the ET from day 2 to day 3 after oocyte retrieval significantly increased implantation rates (13% versus 24%) and ongoing/delivered pregnancy rates per retrieval (26% versus 44%). Day 3 embryos with > or = 8 blastomeres resulted in a significantly higher pregnancy rate (53%) than day 3 embryos with < 8 cells (23%) and day 2 embryos with > or = 4 cells (31%) or < 4 cells (11%). CONCLUSION(S): Day 3 ET was associated with a significant increase in implantation and pregnancy rates. Delaying the ET until day 3 may permit the selection of more viable embryos than on day 2. The absence of glucose and phosphate from the culture media is compatible with good IVF outcomes.


Asunto(s)
Medios de Cultivo/química , Transferencia de Embrión/métodos , Fertilización In Vitro/métodos , Infertilidad Femenina/terapia , Índice de Embarazo , Adulto , Estudios de Cohortes , Intervalos de Confianza , Femenino , Glucosa , Humanos , Infertilidad Femenina/etiología , Fosfatos , Embarazo , Estudios Retrospectivos , Factores de Tiempo
14.
Fertil Steril ; 54(3): 482-8, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2397791

RESUMEN

Zygote intrafallopian transfer (ZIFT) was used as a treatment for long-standing nontubal infertility for a 2-year period. The overall clinical pregnancy rate for 114 tubal transfers was 40.4% with a delivery/ongoing rate of 34.2%. Concurrent use of in vitro fertilization and embryo transfer (IVF-ET) for tubal factor infertility gave significantly lower clinical pregnancy and delivery/ongoing rates (21.1% and 15.8%, respectively). The use of gamete intrafallopian transfer (GIFT) for nontubal infertility yielded a 32% clinical pregnancy rate and a 26% delivery rate for 53 transfers. Zygote intrafallopian transfer resulted in an implantation rate per zygote of 17% overall compared with 8.1% per embryo for IVF-ET and 11.2% per oocyte for GIFT. The transfer of three zygotes per patient gave the same clinical pregnancy rate as the transfer of four while reducing the incidence of multiple gestation from 19% to 7.8% per transfer. No significant decline in the clinical pregnancy or delivery rate was seen with ZIFT in women aged 25 through 39.


Asunto(s)
Transferencia Intrafalopiana del Gameto , Infertilidad Femenina/terapia , Adulto , Transferencia de Embrión , Femenino , Fertilidad , Fertilización In Vitro , Humanos
15.
J Forensic Sci ; 40(2): 306-9, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7602297

RESUMEN

A homicide case in which intact spermatozoa were found in the oral cavity of the deceased forty days after his disappearance is reported. The victim's partially frozen body was found outdoors in a wooded area of upstate New York during the month of January. During a subsequent investigation, pieces of eyeglass lens fragments and bloodstains were found in the suspect's house and vehicle. Chemical and optical analyses of the lens fragments are presented as well as results of the serological tests.


Asunto(s)
Anteojos , Medicina Legal/métodos , Homicidio , Cambios Post Mortem , Espermatozoides , Adulto , Manchas de Sangre , ADN/análisis , Humanos , Masculino , Boca , Reacción en Cadena de la Polimerasa
16.
J Med Assoc Thai ; 84(12): 1674-80, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11999813

RESUMEN

To identify potential environmental and travel factors related to leptospirosis, we conducted an unmatched case controlled study and household assessment of cases and controls in Nakhon Ratchasima province (north-eastern, Thailand) from August to December, 1998. Fifty-six cases and 145 controls were included in the study. Cases were hospitalized patients who had been diagnosed with leptospirosis and tested positive for anti-leptospiral IgM antibody using the Panbio ELISA (Panbio Inc, Brisbane, Australia). Controls were the neighbors of cases who had tested negative. Standardized questionnaires and household assessments were used to collect information on demographics, number of animals kept, evidence of rats in the home, presence of rat food inside the home, road characteristics, awareness of leptospirosis disease, environment, and travel history. Multivariant, unconditional logistic regression demonstrated that travel on potholed roads was independently associated with leptospirosis infection (OR 5.0; 95%CI 1.2-20.2) and traveling by car was a protective factor (OR 0.2; 95%CI 0.06-0.9).


Asunto(s)
Exposición a Riesgos Ambientales/efectos adversos , Leptospirosis/etiología , Viaje , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Tailandia
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