Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Phys Rev Lett ; 115(9): 091302, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26371638

RESUMO

We have searched for periodic variations of the electronic recoil event rate in the (2-6) keV energy range recorded between February 2011 and March 2012 with the XENON100 detector, adding up to 224.6 live days in total. Following a detailed study to establish the stability of the detector and its background contributions during this run, we performed an unbinned profile likelihood analysis to identify any periodicity up to 500 days. We find a global significance of less than 1σ for all periods, suggesting no statistically significant modulation in the data. While the local significance for an annual modulation is 2.8σ, the analysis of a multiple-scatter control sample and the phase of the modulation disfavor a dark matter interpretation. The DAMA/LIBRA annual modulation interpreted as a dark matter signature with axial-vector coupling of weakly interacting massive particles to electrons is excluded at 4.8σ.

2.
Phys Rev Lett ; 111(2): 021301, 2013 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-23889382

RESUMO

We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 224.6 live days×34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129Xe and 131Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV/c², with a minimum cross section of 3.5×10(-40) cm² at a WIMP mass of 45 GeV/c², at 90% confidence level.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 285: 121941, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36208579

RESUMO

Raman spectroscopy was employed to study the thermal denaturation of three different proteins, bovine serum albumin (BSA), lysozyme, ovalbumin; and the decomposition temperature of three amino acids, l-glutamine, l-cysteine, and l-alanine, all of them as lyophilized powders. All the Raman bands observed in the spectra obtained were recorded and analyzed at preset heating temperatures. The results obtained for either protein denaturation temperature TD and amino acid decomposition temperatures TM-dc, were compared with those measured by differential scanning calorimetry (DSC). The DSC and Raman results were additionally corroborated with a thermogravimetric analysis (TGA) for the case of proteins. This exercise indicated almost complete coincidence in the determination of these transition temperatures between the three techniques, evidencing the applicability of Raman spectroscopy in the study of denaturation and decomposition temperatures of proteins and amino acids.


Assuntos
Aminoácidos , Análise Espectral Raman , Desnaturação Proteica , Temperatura , Análise Espectral Raman/métodos , Varredura Diferencial de Calorimetria
4.
Phys Rev Lett ; 109(18): 181301, 2012 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-23215267

RESUMO

We report on a search for particle dark matter with the XENON100 experiment, operated at the Laboratori Nazionali del Gran Sasso for 13 months during 2011 and 2012. XENON100 features an ultralow electromagnetic background of (5.3 ± 0.6) × 10(-3) events/(keV(ee) × kg × day) in the energy region of interest. A blind analysis of 224.6 live days × 34 kg exposure has yielded no evidence for dark matter interactions. The two candidate events observed in the predefined nuclear recoil energy range of 6.6-30.5 keV(nr) are consistent with the background expectation of (1.0 ± 0.2) events. A profile likelihood analysis using a 6.6-43.3 keV(nr) energy range sets the most stringent limit on the spin-independent elastic weakly interacting massive particle-nucleon scattering cross section for weakly interacting massive particle masses above 8 GeV/c(2), with a minimum of 2 × 10(-45) cm(2) at 55 GeV/c(2) and 90% confidence level.

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120269, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34418811

RESUMO

In the present work the temperature response of the constitutive S1 segment of the SARS-CoV-2 Spike Glycoprotein (GPS) has been studied. The intensity of the Raman bands remained almost constant before reaching a temperature of 133 °C. At this temperature a significant reduction of peak intensities was observed. Above 144 °C the spectra ceased to show any recognizable feature as that of the GPS S1, indicating that it had transformed after the denaturation process that it was subjected. The GPS S1 change is irreversible. Hence, Raman Spectroscopy (RS) provides a precision method to determine the denaturation temperature (TD) of dry powder GPS S1. The ability of RS was calibrated through the reproduction of TD of other well studied proteins as well as those of the decomposition temperature of some amino acids (AA). Through this study we established a TD of 139 ± 3 °C for powder GPS S1 of SARS-CoV-2.


Assuntos
COVID-19 , Glicoproteína da Espícula de Coronavírus , Humanos , SARS-CoV-2 , Análise Espectral Raman , Temperatura
6.
Rev Gastroenterol Mex ; 76(2): 173-7, 2011.
Artigo em Espanhol | MEDLINE | ID: mdl-21724494

RESUMO

The presence of perianal endometriosis involving the anal sphincter is a rare presentation of this disease, most cases are diagnosed late and few are reported in the literature despite the number of episiotomies performed today. We present a case in a female with perianal symptoms after an episiotomy 15 years ago and visualized by endoanal ultrasound. We also review the literature of this condition. The treatment of choice is wide excision of the lesion involving the anal sphincter so the sphincter defect should be repaired by sphincteroplasty. According to the literature, early diagnosis by clinical suspicion and confirmation by endoanal ultrasound, with wide excision of endometrioma gives satisfactory results regarding anal continence.


Assuntos
Canal Anal/patologia , Doenças do Ânus/patologia , Endometriose/patologia , Adulto , Canal Anal/diagnóstico por imagem , Canal Anal/cirurgia , Doenças do Ânus/diagnóstico por imagem , Doenças do Ânus/cirurgia , Cicatriz/etiologia , Cicatriz/patologia , Endometriose/diagnóstico por imagem , Endometriose/cirurgia , Episiotomia , Feminino , Humanos , Resultado do Tratamento , Ultrassonografia
7.
Oncol Rep ; 41(2): 1275-1283, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30483800

RESUMO

Prostate cancer (PCa) is the second most common type of male malignancy worldwide. The transcription factor zinc finger E­box binding homeobox 1 (ZEB1) is associated with epithelial­mesenchymal transition and is also involved in regulation of androgen receptor (AR) expression, the main ligands of which are testosterone and dihydrotestosterone (DHT). These androgens are synthesized through the steroidogenic pathway within the prostate, and their synthesis is altered in PCa. The present study aimed to determine the ZEB1­induced alterations in androgen synthesis and AR expression in the DU145 PCa cell line. Reverse transcription­quantitative polymerase chain reaction, western blotting and immunocytochemistry were used to determine the mRNA and protein expression levels, and cellular localization of steroidogenic pathway enzymes in the DU145 cell line in response to ZEB1 silencing. Furthermore, the concentrations of testosterone and DHT were detected in cell culture medium using ELISA. ZEB1­silenced cells exhibited an increase in testosterone and DHT production, an increase in AR expression and an alteration in the steroidogenic pathway. In particular, steroidogenic acute regulatory protein and 5α­reductase 2 expression levels were decreased, whereas cytochrome P450 family 17 subfamily A member 1, 5α­reductase 1, aldo­keto reductase family 1 member D1 and aldo­keto reductase family 1 member C2 expression levels were increased. In conclusion, the present study provided novel information regarding the regulation of intratumoral androgen production in PCa, which is relevant for the progression of the disease to a castration­resistant form.


Assuntos
Di-Hidrotestosterona/metabolismo , Neoplasias de Próstata Resistentes à Castração/metabolismo , Testosterona/biossíntese , Homeobox 1 de Ligação a E-box em Dedo de Zinco/fisiologia , Linhagem Celular Tumoral , Di-Hidrotestosterona/análise , Inativação Gênica , Humanos , Masculino , Próstata/metabolismo , Neoplasias de Próstata Resistentes à Castração/química , Receptores Androgênicos/metabolismo , Testosterona/análise , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética
8.
Rev Gastroenterol Mex ; 73(4): 235-8, 2008.
Artigo em Espanhol | MEDLINE | ID: mdl-19666273

RESUMO

BACKGROUND: Gallstone ileus represents 0.06% of gallstone disease cases as a result of cholecystoenteric fistulae. The presentation is that of intestinal obstruction, the stone is most commonly impacted in the terminal ileum. OBJECTIVE: To present a case of a patient with intestinal obstruction due to a giant stone impacted in the proximal jejunum. CASE REPORT: A 47 year old women presented with abdominal pain, distention, nausea and vomiting.An upper endoscopy revealed a deep duodenal ulcer penetrated to the pancreas. She had partial relief with medical treatment. She was admitted to ourhospital because a new episode of abdominal pain.Physical examination revealed an abdomen with diffuse pain, low peristalsis, leukocytes of 12 000/mm3, neutrophils of 85%, plain abdominal x-ray with intestinal obstruction and pneumobilia, CT scan with intestinal obstruction, hyperdense image in the intestinal lumen and a transition level.Surgery was performed, a giant stone of 6 cm in size was found in the proximal jejunum, an enter olithotomy was performed with primary closure. CONCLUSIONS: Gallstone ileus is a rare condition ofa common disease. It is important in the differential diagnosis in elderly patients with intestinal obstruction. The aim of treatment is to relieve the intestinal obstruction by enterotomy and stone removal.


Assuntos
Fístula Biliar/patologia , Cálculos Biliares/complicações , Cálculos Biliares/patologia , Íleus/etiologia , Íleus/patologia , Fístula Intestinal/patologia , Abdome/patologia , Feminino , Humanos , Obstrução Intestinal/etiologia , Jejuno/patologia , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X
9.
Rev. otorrinolaringol. cir. cabeza cuello ; 83(3): 249-253, 2023. ilus
Artigo em Espanhol | LILACS | ID: biblio-1522101

RESUMO

El neumoencéfalo es una patología que comúnmente se presenta después de cirugía neuroquirúrgica y ocasionalmente endonasal. Estos se suelen manejar de manera conservadora, sin embargo, se pueden asociar a distintas etiologías las cuales los hacen recurrir. En este reporte presentamos dos casos de neumoencéfalo tardío post quirúrgico asociado a fístulas de LCR de bajo flujo, donde se discute su clínica, etiología y manejo posterior.


Pneumocephalus is a pathology that commonly occurs after endonasal surgery, these are usually managed conservatively, however they can be associated with different etiologies which make them recur. In this report we present two cases of post-surgical late pneumocephalus associated with low-flow CSF fistulae, where its symptoms, etiology, and subsequent management are discussed.


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Pneumocefalia/cirurgia , Fístula/líquido cefalorraquidiano , Pneumocefalia/diagnóstico por imagem , Complicações Pós-Operatórias , Imageamento por Ressonância Magnética/métodos , Tomografia por Raios X/métodos
10.
Rev. otorrinolaringol. cir. cabeza cuello ; 83(1): 86-91, mar. 2023. ilus
Artigo em Espanhol | LILACS | ID: biblio-1431958

RESUMO

El neumoencéfalo corresponde a la presencia de aire intracraneal y, en general, es asintomático y autolimitado. Puede ocurrir posterior a trauma, cirugía craneofacial, defectos congénitos, infección, neoplasia o de forma espontánea. El neumoencéfalo a tensión es una emergencia neuroquirúrgica, en la que se acumula aire intracraneal de forma continua que genera un efecto de masa. Clínicamente, se caracteriza por cefalea y un deterioro neurológico marcado. A pesar de ser poco frecuente, es relevante considerar el neumoencéfalo a tensión como una posible complicación en pacientes con antecedente de neurocirugía y/o cirugía otorrinolaringológica, debido a que es una patología potencialmente grave. El diagnóstico es clínico e imagenológico, y requiere de un alto índice de sospecha. Un manejo oportuno es relevante para prevenir la herniación y la muerte.


Pneumocephalus refers to the presence of air in the cranial cavity, and in general, is self-limited and asymptomatic. It can occur after trauma, craniofacial surgery, due to congenital defects, infection, neoplasia or spontaneously. Tension pneumocephalus is a neurosurgical emergency in which intracranial air accumulates continuously, causing a mass effect. It presents with headache and marked neurological deterioration. Despite being rare, it is relevant to consider tension pneumocephalus as a possible complication in patients with a history of neurosurgery and/or otolaryngology surgery, as it can be life-threatening. Diagnosis requires a high index of suspicion and imagenologic confirmation. Timely management is relevant to prevent herniation and death.


Assuntos
Humanos , Pneumocefalia/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Hipertensão Intracraniana/diagnóstico por imagem
11.
Rev. otorrinolaringol. cir. cabeza cuello ; 82(2): 195-198, jun. 2022.
Artigo em Espanhol | LILACS | ID: biblio-1389856

RESUMO

Resumen La amigdalectomía es uno de los procedimientos quirúrgicos más frecuentes que realiza el otorrinolaringólogo. Dentro de las complicaciones posoperatorias, la neuralgia del nervio glosofaríngeo es extremadamente poco frecuente. En este artículo se presentan dos casos clínicos pediátricos con neuralgia del glosofaríngeo posamigdalectomía que fueron resueltos con tratamiento médico.


Abstract Tonsillectomy is one of the most common procedures done by the otolaryngologist. Among post-operative complications, the glossopharyngeal neuralgia is extremely uncommon. This article presents two pediatric clinical cases with post-tonsillectomy glossopharyngeal neuralgia that were resolved with medical treatment.


Assuntos
Humanos , Pré-Escolar , Complicações Pós-Operatórias , Tonsilectomia/efeitos adversos , Doenças do Nervo Glossofaríngeo , Doenças do Nervo Glossofaríngeo/diagnóstico , Nervo Glossofaríngeo , Neuralgia
12.
Biocell ; 30(3): 423-9, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17375462

RESUMO

Parathion is an organophosphorate pesticide amply used in agriculture. Many alterations induced by organophosphorate pesticides have been described, such as: cytogenetic alterations in germinal cells, oligozoospermia and teratozoospermia in the mouse. The effect of Parathion, both pure (PP) and commercial (PC), on mouse interstitial cell testosterone production was evaluated in vivo and in vitro. Male mice were intraperitoneally injected with a single dose of 1/3 LD50 of Parathion, both PP and PC. The animals were sacrificed at 1, 8 and 40 days post injection to evaluate the impact of disrupting testosterone production on spermatogonia, spermatocytes and elongated spermatids. The plasma testosterone was assayed by standard radioimmunoanalysis. The same method was used to assay testosterone in the culture medium of interstitial cells obtained from the control and Parathion treated animals at the same time intervals. Sperm count, sperm teratozoospermia and tubular blockage were analyzed for an appraisal of spermatogenesis. Increase in the teratozoospermia and tubular blockage was detected in the PP and PC group at 8 and 40 days post injection. Plasma testosterone levels drop significantly at 8 days and recovered slowly at 40 days only in PP animals as detected in vivo, implying interference of testicular steroidogenesis due to the toxicant. Recuperation of normality occurs at long time intervals. In conclusion, Parathion disturbs the synthesis of testosterone in mice affecting qualitatively the spermatogenesis


Assuntos
Inseticidas/toxicidade , Paration/toxicidade , Espermatogênese/efeitos dos fármacos , Testosterona/biossíntese , Acetilcolinesterase/sangue , Animais , Masculino , Camundongos , Camundongos Endogâmicos , Contagem de Espermatozoides , Espermatozoides/anormalidades , Testosterona/sangue
13.
Rev Biol Trop ; 54(1): 83-92, 2006 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-18457178

RESUMO

The seaweed Sargassum (Sargassaceae) as tropical alternative for goats' feeding. The nutritive value of seaweed (Sargassum spp.) was studied in Baja California Sur, Mexico. Twenty female Nubian goats (43-weeks old) were randomly distributed into two groups of 10 goats each and were housed in individual pens. One group was fed with a control diet and the other with a diet supplemented with 25% of Sargassum spp. Feed and water intake were recorded daily and individually for 60 days. The weight of each goat was recorded every 15 days. The nutritional content of Sargassum spp. was 89% dry mater, 8% crude protein, 31% ash, 2% ether extract, and 39% carbohydrates. Fiber fractions, minerals, vitamins, fatty acids, and antinutritional factors were also determined. There were no significant differences in body weight (8.6 kg control and 9 kg experimental), feed intake (1.3 kg control and 1.6 kg experimental), and feed conversion rate (11.1 control and 12.6 experimental). Water consumption was greater in the goats that ate the Sargassum diet (5.3 1). From these results, Sargassum spp. can be considered as an alternative feedstuff for goats.


Assuntos
Ração Animal/análise , Cabras , Sargassum/química , Animais , Feminino , Valor Nutritivo
14.
J Mol Biol ; 312(1): 157-65, 2001 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-11545593

RESUMO

The process of N-glycosylation of eukaryotic proteins involves a range of host enzymes that delete or add saccharide monomers. While endoplasmic reticulum (E.R.) mannosidases cleave only one mannose to produce the Man8B isomer, an alpha-1,2-mannosidase from Trichoderma reesei can sequentially cleave all four 1,2-linked mannose sugars from a Man(9)GlcNAc(2) oligosaccharide, a feature reminiscent of the activity of Golgi mannosidases. We now report the structure of the T. reesei enzyme at 2.37 A resolution. The enzyme folds as an (alpha alpha)(7) barrel. The substrate-binding site of the T. reesei mannosidase differs appreciably from the Saccharomyces cerevisiae enzyme. In the former, shorter loops at the surface allow substrate protein to come closer to the catalytic site. There is more internal space available, so that different oligosaccharide conformations are sterically allowed in the T. reesei alpha-1,2-mannosidase.


Assuntos
Manose/metabolismo , Manosidases/química , Manosidases/metabolismo , Trichoderma/enzimologia , Sequência de Aminoácidos , Sítios de Ligação , Configuração de Carboidratos , Carboidratos/química , Domínio Catalítico , Cristalografia por Raios X , Manose/química , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Especificidade por Substrato
15.
Med. U.P.B ; 39(1): 49-56, 24 de febrero de 2020. tab, Ilus, mapas
Artigo em Espanhol | COLNAL, LILACS | ID: biblio-1052279

RESUMO

Las enfermedades cardiovasculares son la principal causa de muerte en el mundo. Su incidencia y prevalencia aumentan con la edad y con los diferentes factores de riesgo. La mayoría de estos factores tienen una relación estrecha con el estilo de vida; factores como la dislipidemia, el tabaquismo, la hipertensión, la diabetes mellitus, la obesidad y el estrés son cada vez más prevalentes y varían según la población y localización geográfica. Por eso se realiza una revisión de la epidemiología mundial y nacional del síndrome coronario agudo, y de cómo este ha variado a través de los años. Se buscó literatura en inglés y español en diferentes bases de datos, fueron seleccionados 50 artículos que se presentan haciendo énfasis en el impacto epidemiológico del síndrome coronario agudo. Luego de realizar la revisión detallada se concluye que la enfermedad cardiovascular persiste como primera causa mundial de morbimortalidad, con aumento en su frecuencia durante los últimos años. El síndrome coronario agudo es la afección que provoca más muertes entre todos los eventos, con incidencia, edad de presentación, impacto económico y factores de riesgo diferentes de acuerdo con cada región. Los factores de riesgo modificables siguen siendo muy importantes en el desarrollo de enfermedades cardiovasculares.


Cardiovascular diseases are the main cause of mortality all over the world. Their incidence and prevalence increase with age and different risk factors. The majority of factors are closely related to the lifestyle; aspects such as hypertension, diabetes mellitus, obesity, and stress are more prevalent day by day and vary according to the population and its geographical location. The researchers made a revision on international and national epidemiology of the acute coronary syndrome and it has changed over the years. The study included literature published in both English and Spanish retrieved from different databases. For this particular case, 50 articles focused on the epidemiologic impact of the acute coronary syndrome were reviewed. After a detailed revision, it can be said that the cardiovascular disease, which has been increasing during the past years, remains as the first cause of morbidity and mortality at the worldwide level. This syndrome causes more deaths in all events, with different incidence, age in which it takes place, economic impact and risk factors, depending on each region. The modifiable risk factors are still very important in the development of cardiovascular diseases.


As doenças cardiovasculares são as principais causas de morte no mundo. Sua incidência e prevalência aumentam com a idade e com os diferentes fatores de risco. A maioria destes fatores têm uma relação estreita com o estilo de vida; fatores como a dislipidemia, o tabaquismo, a hipertensão, a diabetes mellitus, a obesidade e o estresse são cada vez mais prevalentes e variam segundo a população e localização geográfica. Por isso se realiza uma revisão da epidemiologia mundial e nacional da síndrome coronária aguda, e de como este há variado através dos anos. Se buscou literatura em inglês e espanhol em diferentes bases de dados, foram selecionados 50 artigos que se apresentam fazendo ênfase no impacto epidemiológico da síndrome coronária aguda. Logo de realizar a revisão detalhada se conclui que a doença cardiovascular persiste como primeira causa mundial de morbimortalidade, com aumento na sua frequência durante os últimos anos. A síndrome coronária aguda é a afecção que provoca mais mortes entre todos os eventos, com incidência, idade de apresentação, impacto econômico e fatores de risco diferentes de acordo com cada região. Os fatores de risco modificáveis seguem sendo muito importantes no desenvolvimento de doenças cardiovasculares.


Assuntos
Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares , Tabagismo , Trombose Coronária , Angiografia , Síndrome Coronariana Aguda , Hipertensão , Estilo de Vida , Obesidade
16.
Oncol Rep ; 33(4): 1599-608, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25606819

RESUMO

In the early stages, prostate cancer is androgen­ dependent; therefore, medical castration has shown significant results during the initial stages of this pathology. Despite this early effect, advanced prostate cancer is resilient to such treatment. Recent evidence shows that derivatives of Cannabis sativa and its analogs may exert a protective effect against different types of oncologic pathologies. The purpose of the present study was to detect the presence of cannabinoid receptors (CB1 and CB2) on cancer cells with a prostatic origin and to evaluate the effect of the in vitro use of synthetic analogs. In order to do this, we used a commercial cell line and primary cultures derived from prostate cancer and benign prostatic hyperplasia. The presence of the CB1 and CB2 receptors was determined by immunohistochemistry where we showed a higher expression of these receptors in later stages of the disease (samples with a high Gleason score). Later, treatments were conducted using anandamide, 2-arachidonoyl glycerol and a synthetic analog of anandamide, methanandamide. Using the MTT assay, we proved that the treatments produced a cell growth inhibitory effect on all the different prostate cancer cultures. This effect was demonstrated to be dose-dependent. The use of a specific CB1 receptor blocker (SR141716) confirmed that this effect was produced primarily from the activation of the CB1 receptor. In order to understand the MTT assay results, we determined cell cycle distribution by flow cytometry, which showed no variation at the different cell cycle stages in all the cultures after treatment. Treatment with endocannabinoids resulted in an increase in the percentage of apoptotic cells as determined by Annexin V assays and caused an increase in the levels of activated caspase-3 and a reduction in the levels of Bcl-2 confirming that the reduction in cell viability noted in the MTT assay was caused by the activation of the apoptotic pathway. Finally, we observed that endocannabinoid treatment activated the Erk pathway and at the same time, produced a decrease in the activation levels of the Akt pathway. Based on these results, we suggest that endocannabinoids may be a beneficial option for the treatment of prostate cancer that has become nonresponsive to common therapies.


Assuntos
Adenocarcinoma/patologia , Endocanabinoides/farmacologia , Proteínas de Neoplasias/efeitos dos fármacos , Neoplasias da Próstata/patologia , Receptor CB1 de Canabinoide/efeitos dos fármacos , Receptor CB2 de Canabinoide/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Ácidos Araquidônicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Glicerídeos/farmacologia , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/antagonistas & inibidores , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Hiperplasia Prostática/patologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Pirazóis/farmacologia , Receptor CB1 de Canabinoide/análise , Receptor CB2 de Canabinoide/análise , Rimonabanto , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas
17.
J Steroid Biochem Mol Biol ; 51(1-2): 73-9, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7947353

RESUMO

3 beta-Hydroxysteroid dehydrogenase (3 beta-HSD) is one of the key enzymes involved in the steroidogenic pathway of Leydig cells. In this study, quantitative cytochemistry was used to detect the 3 beta-HSD staining intensity in individual rat Leydig cells. The measurement of the intensity of staining was a reliable method reflecting the relative amount of 3 beta-HSD activity. The objective was to determine the presence, basal and hCG-mediated effect of 3 beta-HSD activity in individual Leydig cells. 3 beta-HSD cytochemistry was performed in both, 8 and 12 microns diameter rat Leydig cells. The results showed that both populations of Leydig cells have different basal 3 beta-HSD activity. The 8 microns cells showed a greater basal 3 beta-HSD activity than the 12 microns cells when their optical density values were normalized to their size. A difference in regulation of the enzymatic activity by LH/hCG was observed in the two types of Leydig cells. Incubation of the whole population of Leydig cells with hCG (1IU), decreased the 3 beta-HSD activity in the 8 microns cells, but increased the activity in the 12 microns cells. The results describe for the first time that the 3 beta-HSD activity may be differentially regulated by LH/hCG in Leydig cells.


Assuntos
3-Hidroxiesteroide Desidrogenases/metabolismo , Células Intersticiais do Testículo/enzimologia , 3-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Animais , Células Cultivadas , Gonadotropina Coriônica/farmacologia , Cianocetona/farmacologia , Masculino , Ratos , Ratos Wistar
18.
J Biotechnol ; 77(2-3): 255-63, 2000 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-10682284

RESUMO

A cDNA encoding 1,2-alpha-D-mannosidase mds 1 from Trichoderma reesei was cloned. The largest open reading frame occupied 1571 bp. The predicted sequence contains 523 amino acid residues for a calculated molecular mass of 56,266 Da and shows high similarity to the amino acid sequences of 1,2-alpha-D-mannosidases from Aspergillus saitoi and Penicillium citrinum (51.6 and 51.0% identity, respectively). T. reesei mannosidase was produced as a recombinant enzyme in the yeast Pichia pastoris. Replacement of the N-terminal part with the prepro-signal peptide of the Saccharomyces cerevisiae alpha-mating factor resulted in high amounts of secreted enzyme. A three-step purification protocol was designed and the enzymatic properties were analyzed. The enzyme was characterized as a class-I mannosidase.


Assuntos
Clonagem Molecular , Manosidases/genética , Manosidases/metabolismo , Trichoderma/enzimologia , Sequência de Aminoácidos , Aspergillus/enzimologia , DNA Complementar , Manosidases/química , Fator de Acasalamento , Dados de Sequência Molecular , Penicillium/enzimologia , Peptídeos/genética , Pichia/enzimologia , Pichia/genética , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes de Fusão , Proteínas Recombinantes , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Alinhamento de Sequência
19.
Adv Exp Med Biol ; 444: 201-6, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-10026950

RESUMO

Parathion is a widely used organophosphoric pesticide which has also been reported to interfere with mouse spermatogenesis. Moreover it has been related to prenatal toxicity in mammals. Sixteen A/ Snell mice were sacrificed at day 17 of pregnancy. Testes and epididymides of the male fetuses were implanted in the allantochorion of chicken eggs. Three experimental conditions of the egg injections were considered: Group I: 1 ml of parathion (0.5 mg/ml), Group II: 1 ml of parathion (1 mg/ml), and Group III: 1 ml distilled water (control group). The implanted subjects continued their development for 4 days (i.e. to complete the gestational period for mice). The cell proliferation and differentiation of the epithelial cells of the epididymis were evaluated with the use of the monoclonal antiproliferating cell nuclear antigen (PCNA-cyclin) antibody, and the AE1 keratin complex antibody. Parathion altered the allantochorion, as 15% of the chicken embryos died in Group I and 40% in Group II, vs. only 8% in controls (Group III). However, no malformations were seen in the surviving embryos. In the testicular implants, the seminiferous cords of Group I had the same cytological characteristics of germ and pre-Sertoli cells as the control, except for involuting Leydig cells. Contrarily, in the cases with higher doses of parathion (Group II), there was a complete disorganisation of the seminiferous cords and the interstitium. In some testes, hyaline degeneration of the seminiferous cords was observed. No cell proliferation was evident, and the epididymal morphology was apparently unaffected. Therefore, parathion seems to interfere with normal testicular differentiation. However, in spite of interstitial damage, the epididymal development seems unaltered. Since the epididymis is an androgen-dependent organ, it may be postulated that testosterone production is still sufficient to support epididymal development but not spermatogenic cell line differentiation.


Assuntos
Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Epididimo/efeitos dos fármacos , Paration/toxicidade , Testículo/efeitos dos fármacos , Alantoide , Animais , Embrião de Galinha , Córion , Epididimo/embriologia , Epididimo/patologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos , Técnicas de Cultura de Órgãos , Gravidez , Testículo/embriologia , Testículo/patologia
20.
Int J Gynaecol Obstet ; 57(2): 139-43, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9184950

RESUMO

OBJECTIVE: To determine the efficacy and safety of intravaginal misoprostol compared with intravenous oxytocin in cervical ripening and labor induction. METHOD: The study was carried out at the Department of Obstetrics and Gynecology at the Hospital Loayza, Lima, Peru. The sample included 123 pregnant women with any indication for labor induction. The study was prospective and randomized. We compared the effect of 50 micrograms of intravaginal misoprostol administered every 4 h up to 600 micrograms with that observed using the standard protocol of oxytocin by continuous infusion. RESULTS: 57 patients with misoprostol (group 1) and 63 with oxytocin (group 2) were enrolled. Delivery occurred in 45 patients (78.9%) in group 1 and in 37 (58.7%) in group 2 (P < 0.017). Complications including tachysystole, uterine hypertony and hyperstimulation were higher in group 1, 21.1% than in group 2, 7.9% (P < 0.04). The incidence of cesarean section in both groups was similar to the overall incidence in our center. No differences were observed between groups in perinatal and postpartum adverse outcomes. The interval from start of induction to vaginal delivery was significantly shorter in the oxytocin group (8.4 +/- 4.1 vs. 11.3 +/- 6.9 h, P < 0.005). CONCLUSION: Intravaginal administration of misoprostol is a safe and effective alternative for cervical ripening and labor induction. Maternal and neonatal complications did not increase significantly.


Assuntos
Abortivos não Esteroides/administração & dosagem , Trabalho de Parto Induzido/métodos , Misoprostol/administração & dosagem , Ocitocina/administração & dosagem , Resultado da Gravidez , Administração Intravaginal , Adulto , Feminino , Humanos , Infusões Intravenosas , Gravidez , Estudos Prospectivos , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA