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1.
Analyst ; 144(1): 299-309, 2018 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-30403208

RESUMEN

There are two forms of vitamin D which are essential to the human body, i.e. vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). The inactive metabolites of vitamin D are commonly used for quantitative analysis because of their longer half-life, stability, and relatively high blood concentrations. This paper presents the development of a high-throughput and sensitive method for determining four vitamin D metabolites in dried blood spots using liquid chromatography coupled with tandem mass spectrometry. This method allows for the determination of 25(OH)D2 and 25(OH)D3 concentrations, as well as the epimeric form 3-epi-25(OH)D3 and 24,25(OH)2D3. The analyzed material is capillary blood taken from the fingertip, deposited on filter paper. Four different chromatographic columns were tested to separate all compounds, in particular, the epimeric form. The column of choice was F5 (Phenomenex, Torrance, CA, USA). In order to prove the consistency between the results for DBS, used as an alternative biological matrix, and serum, comparative studies of these two materials were carried out in nearly 100 individuals. The results indicated their positive correlation. The evaluation of short-term stability of metabolites in DBS within the month showed no change in metabolite concentration. During the validation, the impact of the matrix on the ionization of the tested compounds was evaluated. Capillary blood and venous blood collected for different anticoagulants were also compared. The smallest differences in the results were obtained for citrate. In order to achieve a limit of quantitation of 0.2 ng ml-1, sample preparation involved derivatization using a Cookson-type reagent, 4-(4'-dimethylaminophenyl)-1,2,4-triazoline-3,5-dione (DAPTAD).


Asunto(s)
Pruebas con Sangre Seca/métodos , Hidroxicolecalciferoles/análisis , Compuestos de Anilina/química , Cromatografía Liquida/métodos , Femenino , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Hidroxicolecalciferoles/química , Límite de Detección , Masculino , Estereoisomerismo , Espectrometría de Masas en Tándem/métodos , Triazoles/química
2.
Brain Spine ; 4: 102822, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38831935

RESUMEN

Introduction: Technical advances and the increasing role of interdisciplinary decision-making may warrant formal definitions of expertise in surgical neuro-oncology. Research question: The EANS Neuro-oncology Section felt that a survey detailing the European neurosurgical perspective on the concept of expertise in surgical neuro-oncology might be helpful. Material and methods: The EANS Neuro-oncology Section panel developed an online survey asking questions regarding criteria for expertise in neuro-oncological surgery and sent it to all individual EANS members. Results: Our questionnaire was completed by 251 respondents (consultants: 80.1%) from 42 countries. 67.7% would accept a lifetime caseload of >200 cases and 86.7% an annual caseload of >50 as evidence of neuro-oncological surgical expertise. A majority felt that surgeons who do not treat children (56.2%), do not have experience with spinal fusion (78.1%) or peripheral nerve tumors (71.7%) may still be considered experts. Majorities believed that expertise requires the use of skull-base approaches (85.8%), intraoperative monitoring (83.4%), awake craniotomies (77.3%), and neuro-endoscopy (75.5%) as well as continuing education of at least 1/year (100.0%), a research background (80.0%) and teaching activities (78.7%), and formal interdisciplinary collaborations (e.g., tumor board: 93.0%). Academic vs. non-academic affiliation, career position, years of neurosurgical experience, country of practice, and primary clinical interest had a minor influence on the respondents' opinions. Discussion and conclusion: Opinions among neurosurgeons regarding the characteristics and features of expertise in neuro-oncology vary surprisingly little. Large majorities favoring certain thresholds and qualitative criteria suggest a consensus definition might be possible.

3.
Cerebellum ; 12(3): 418-28, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23090211

RESUMEN

Although ataxia is by definition the prominent symptom of ataxia disorders, there are various neurological signs that may accompany ataxia in affected patients. Reliable and quantitative assessment of these signs is important because they contribute to disability, but may also interfere with ataxia. Therefore we devised the Inventory of Non-Ataxia Signs (INAS), a list of neurological signs that allows determining the presence and severity of non-ataxia signs in a standardized way. INAS underwent a rigorous validation procedure that involved a trial of 140 patients with spinocerebellar ataxia (SCA) for testing of inter-rater reliability and another trial of 28 SCA patients to assess short-term intra-rater reliability. In addition, data of the ongoing EUROSCA natural history study were used to determine the reproducibility, responsiveness and validity of INAS. Inter-rater reliability and short-term test-retest reliability was high, both for the total count and for most of the items. However, measures of responsiveness, such as the smallest detectable change and the clinically important change were not satisfactory. In addition, INAS did not differentiate between subjects that were subjectively stable and those that worsened in the 2-year observation period. In summary, INAS and INAS count showed good reproducibility, but unsatisfactory responsiveness. The present analysis and published data from the EUROSCA natural history study suggest that INAS is a valid measure of extracerebellar involvement in progressive ataxia disorders. As such, it is useful as a supplement to the measures of ataxia, but not as a primary outcome measure in future interventional trials.


Asunto(s)
Examen Neurológico , Índice de Severidad de la Enfermedad , Ataxias Espinocerebelosas/diagnóstico , Área Bajo la Curva , Europa (Continente) , Femenino , Humanos , Estudios Longitudinales , Masculino , Psicometría , Reproducibilidad de los Resultados , Ataxias Espinocerebelosas/clasificación , Ataxias Espinocerebelosas/genética , Estadística como Asunto
4.
Cureus ; 15(1): e33706, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36788915

RESUMEN

Acanthosis nigricans (AN) is a common chronic disorder that is characterized by velvety-like, hyperpigmented, hyperkeratotic plaques, typically in intertriginous areas. However, atypical presentations have been reported. Here we present a five-year-old boy presented with a one-year history of asymptomatic slowly progressing skin lesions. He is a known case of type 1 diabetes mellites on insulin treatment, otherwise healthy. The review of systems was unremarkable. No similar case was found in the family. Skin examination revealed multiple tiny non-scaly brownish papules on the medial aspects of the upper thighs, bilaterally. Differential diagnosis included skin tags, viral warts, and dermatosis papulose nigra (DPN). Dermoscopic findings revealed a velvety-like appearance on the papules and the normal skin surrounding the papules. A 2-mm punch skin biopsy of the papule revealed papillomatosis of the epidermis, and the granular layer was normal. The dermis was normal. On the basis of the above clinicopathological findings, specifically the velvety texture of the normal skin surrounding the papules, the patient was diagnosed with ANs. The parent was reassured, and we started the patient on daily tretinoin cream.

5.
Cureus ; 15(2): e34816, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36915846

RESUMEN

Background Foreign body aspiration (FBA) is a life-threatening event and one of the most common causes of mortality in children. As it has different clinical presentations, parental knowledge is essential for early management to prevent complications. Objectives This study was designed to assess the knowledge and practices relating to FBA in children among parents living in Makkah city, Saudi Arabia. Methods An online questionnaire was designed using Google Forms (Google LLC, Mountain View, California, United States) and distributed in October 2022 among parents living in Makkah city. After data collection, an appropriate statistical analysis was conducted. Results A total of 1087 parents enrolled in this study; 63.9% were women and the majority were married 93%. Additionally, 52% of the parents had at least three children. Moreover, 17.6% had an experience of a child having aspirated a foreign body once. The Internet was the most popular source of information on FBA (43.5%). Furthermore, the parents had poor levels of knowledge and practices related to FBA (65.4% and 78.6%, respectively). Conclusion This study reported that parental levels of knowledge of FBA and FBA practices were inadequate. There is a need to increase awareness, which will lead to better outcomes.

6.
Cureus ; 15(3): e35776, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37025729

RESUMEN

Diffuse capillary malformation with overgrowth (DCMO) is a rare condition that is characterized by capillary malformation and soft tissue hypertrophy. Here we report the case of a one-year-old male child with no past medical history who presented with skin lesions persistent since birth and associated with no symptoms. There were widespread non-scaly reticulated erythematous patches all over his body, including the abdominal wall. The circumference of the right calf and mid-thigh was 13 cm and 20 cm respectively whereas the circumference of the left calf and mid-thigh was 11 cm and 18 cm respectively. The length of both lower extremities was similar. There was also syndactyly of the right second and third toes. Differential diagnoses include cutis marmorata telangiectatica congenita (CMTC), DCMO, and macrocephaly-capillary malformation (M-CM) syndrome. Based on clinical features, the patient was diagnosed with DCMO. He was put under follow-up by pediatric orthopedics for periodic monitoring of growth asymmetry.

7.
J Family Med Prim Care ; 12(6): 1137-1144, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37636193

RESUMEN

Background: Social media (SM) usage is on the rise among health professionals at all levels to align with the emerging digital and SM era. e-Professionalism is described as attitudes and actions that resemble traditional professionalism paradigms but are expressed through digital media. Although there are a number of studies conducted in the past several years measuring e-professionalism of medical and dental professionals, there is no validated scale to assess the level of e-professionalism among medical and dental professionals in Saudi Arabia. Therefore, this study aimed to assess attitudes toward e-professionalism among medical and dental professionals in Saudi Arabia using the SMePROF-S scale. Methods: This cross-sectional study recruited 338 medical and dental students and practitioners from 20 cities in Saudi Arabia to complete an online SMePROF-S self-reported questionnaire measuring attitudes about e-professionalism. Results: Among participants, 31.66% believed that it is acceptable to communicate with patients through SM, but only 16.86% agreed with communicating via personal SM account messaging. Many participants (35.80%-50%) fear that SM use can cause problems with getting hired, people making inaccurate assumptions and perceptions, and job losses. There were 31.36% who believed that sharing patient information without consent is acceptable. The majority (63.02%-63.31%) do not believe that medical/dental professionals should be barred from using SM, and 40.53% believe that schools/organizations have no right to interfere with their online activities. Only 22.19% believed that SM use removed professional protections from the public. A few statements were statistically different by specialty and gender. Conclusion: There is a variability of attitudes about e-professionalism among medical and dental professionals in Saudi Arabia, with some alarming issues requiring national guidelines to ensure patient rights, privacy, and confidentiality.

8.
J Pharm Biomed Anal ; 190: 113529, 2020 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-32841780

RESUMEN

Despite the fact that more than 90% of vitamin D analysis are performed using immuno-enzymatic techniques, it is liquid chromatography coupled with tandem mass spectrometry that is currently the reference method. It allows for specific and selective analysis of all relevant vitamin D metabolites from a variety of biological materials, including serum or a dried blood spot. This paper presents development of a fast, cheap and high-throughput method of serum sample preparation using protein precipitation. For this purpose, organic solvent is used. Several substances were tested, including acetonitrile, methanol and their mixtures with zinc sulfate. However, the highest recovery values for the vitamin D metabolites were obtained for acetonitrile, with an organic solvent to serum ratio of 8:1. The preparation of a sample is carried out in 96-well plates and takes an hour and a half, together with a derivatization reaction using Cookson-type reagent 4-(4'-dimethylaminophenyl)-1,2,4-triazoline-3,5-dione. Due to the fact that vitamin D metabolites are bound to proteins, the relationship between the content of organic solvent in the sample preparation process and their release from the protein complex was examined. The results indicate that the organic solvent content should be 30-70% in order to completely release the tested compounds from the proteins. In addition, the developed chromatographic method has eliminated false positive signals for the 24,25(OH)2D3 metabolite. Total analysis time is 5.5 min., while maintaining resolution necessary to separate the analyzed compounds.


Asunto(s)
Espectrometría de Masas en Tándem , Vitamina D , Cromatografía Liquida , Indicadores y Reactivos , Límite de Detección
9.
Neuroscience ; 155(1): 53-63, 2008 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-18571868

RESUMEN

Pyramidal neurons of the medial prefrontal cortex (mPFC) exhibit dopamine-dependent prolonged depolarization, which may lead to persistent activity. Persistent activation of prefrontal cortex neurons has been proposed to underlie the working memory process. The purpose of our study was to test the hypothesis that activation of D(1) dopamine receptors leads to inhibition of G protein-dependent inward rectifier K(+) (GIRK) channels, thereby supporting the prolonged depolarization of mPFC pyramidal neurons. Experiments were performed on 3-week-old rats. GIRK-like channel currents recorded from pyramidal neurons showed the following properties at -75 mV: open probability (NPo), 2.5+/-0.3 x 10(-3); mean open time, 0.53+/-0.05 ms; and conductance, 29.9+/-1.6 pS (n=60). The channel currents were strongly inward-rectified. GIRK channel currents were reversibly inhibited by the D(1) agonists SKF 38393 (10 microM) and SKF 81297 (10 microM). This inhibition was abolished by prior application of a dopamine receptor antagonist and by application of the membrane-permeable protein kinase C inhibitors chelerythrine chloride (3 microM) and calphostin C (10 microM). It was also found that the application of D(1) dopamine receptor agonists or GIRK channel inhibitors evoked depolarization of mPFC pyramidal neurons in rats. Moreover, prior application of a GIRK channel blocker eliminated the depolarizing effect of D(1) agonists. We conclude that activation of D(1) dopamine receptors may lead to inhibition of GIRK channel currents that may, in turn, lead to the prolonged depolarization of mPFC pyramidal neurons in juvenile rats.


Asunto(s)
Canales de Potasio Rectificados Internamente Asociados a la Proteína G/fisiología , Corteza Prefrontal/citología , Células Piramidales/fisiología , Receptores de Dopamina D1/fisiología , Análisis de Varianza , Animales , Venenos de Abeja/farmacología , Dopaminérgicos/farmacología , Relación Dosis-Respuesta en la Radiación , Interacciones Farmacológicas , Estimulación Eléctrica/métodos , Inhibidores Enzimáticos/farmacología , Técnicas In Vitro , Masculino , Naftalenos/farmacología , Técnicas de Placa-Clamp/métodos , Bloqueadores de los Canales de Potasio/farmacología , Células Piramidales/efectos de los fármacos , Células Piramidales/efectos de la radiación , Ratas , Ratas Wistar , Acetato de Tetradecanoilforbol/análogos & derivados , Acetato de Tetradecanoilforbol/farmacología , Factores de Tiempo
10.
J Physiol Pharmacol ; 58 Suppl 5(Pt 2): 575-82, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18204171

RESUMEN

Fifty five patients with ischemic stroke and 15 patients with transient ischemic attacks (TIA) were screened for sleep related breathing disorders (SRBD). Apnea-hypopnea index (AHI) and desaturation index (DI) were analyzed. The clinical status was assessed with National Institute of Health Stroke Scale (NIHSS). The patients with stroke were stratified into groups: without (AHI10). SRBD were present in 36 patients with stroke and in 10 patients with TIA. There were significant differences in the clinical status on admission, as quantified with NIHSS, between stroke patients with mild and moderate or severe SRBD. AHI positively correlated with NIHSS on admission in stroke patients (r=0.54, P<0.01). The final NIHSS score was significantly greater in patients with moderate or severe SRBD than in those with mild SRBD: 3.4+/-1.9 and 1.8+/-1.2, respectively. Our data suggest that the severity of SRBD is related to the clinical status on admission and it influence the clinical outcome after ischemic stroke.


Asunto(s)
Isquemia Encefálica/complicaciones , Ataque Isquémico Transitorio/complicaciones , Mecánica Respiratoria/fisiología , Síndromes de la Apnea del Sueño/etiología , Síndromes de la Apnea del Sueño/fisiopatología , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/etiología , Anciano , Isquemia Encefálica/epidemiología , Femenino , Humanos , Ataque Isquémico Transitorio/epidemiología , Masculino , Persona de Mediana Edad , Polonia/epidemiología , Factores de Riesgo , Síndromes de la Apnea del Sueño/epidemiología , Accidente Cerebrovascular/epidemiología , Resultado del Tratamiento
11.
J Physiol Pharmacol ; 68(2): 209-214, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28614770

RESUMEN

Phosphate-activated glutaminase (GA), a ubiquitous glutamine-metabolizing enzyme, is encoded by two genes, GLS and GLS2. In mammalian cancers, GLS isoforms are perceived as molecules promoting cell proliferation and invasion, whereas the role of GLS2 isoforms seems to be more complex and cell type-specific. Previous studies have shown abundance of GLS and lack of GLS2 transcripts in T98G human glioblastoma (GBM) cell line and patient-derived GBM. Transfection with GAB sequence, the whole GLS2 cDNA transcript, suppressed malignant phenotype of T98G cells. Microarray analysis revealed upregulation of GATA3, the product of which has been implicated in suppressing growth of some peripheral cancers. In this study we confirmed a significant upregulation of GATA3 expression in the transfected cells both at mRNA and protein level. Considerable expression of GATA3 was also observed in GBM tissues (previously shown as not expressing GLS2), while only traces or no GATA3 was detected in (GLS2-expressing) non-tumorigenic brain samples. In conclusion, while mechanistic relation between GAB and GATA3 expression is evident following in vitro manipulation of GBM cell line, it does not appear to be an intrinsic property of GBM nor non-tumorigenic brain tissue.


Asunto(s)
Neoplasias Encefálicas/genética , Factor de Transcripción GATA3/genética , Glioblastoma/genética , Glutaminasa/genética , Adulto , Anciano , Encéfalo/metabolismo , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Femenino , Factor de Transcripción GATA3/metabolismo , Glioblastoma/metabolismo , Humanos , Masculino , Persona de Mediana Edad
12.
Radiat Prot Dosimetry ; 122(1-4): 228-36, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17166877

RESUMEN

Past work has shown that neural precursor cells are predisposed to redox sensitive changes, and that oxidative stress plays a critical role in the acute and persistent changes that occur within the irradiated CNS. Irradiation leads to a marked rise in reactive oxygen species (ROS) that correlates with oxidative endpoints in vivo and reductions in neurogenesis. To better understand the impact of oxidative stress on neural precursor cells, and to determine if radiation-induced oxidative damage and precursor cell loss after irradiation could be reduced, a series of antioxidant compounds (EUK-134, EUK-163, EUK-172, EUK-189) were tested, three of which possess both superoxide dismutase (SOD) and catalase activities and one (EUK-163) whose only significant activity is SOD. Our results show that these SOD/catalase mimetics apparently increase the oxidation of a ROS-sensitive fluorescent indicator dye, particularly after short (12 h) treatments, but that longer treatments (24 h) decrease oxidation attributable to radiation-induced ROS. Similarly, other studies found that cells incubated with CuZnSOD showed some increase in intracellular ROS levels. Subsequent data suggested that the dye-oxidising capabilities of the EUK compounds were linked to differences in their catalase activity and, most likely, their ability to catalyse peroxidative pathways. In unirradiated mice, the EUK-134 analogue induced some decrease of proliferating precursor cells and immature neurons 48 h after radiation, an effect that may be attributable to cytotoxicity and/or inhibition of precursor proliferation. In irradiated mice, a single injection of EUK-134 was not found to be an effective radioprotector at acute times (48 h). The present results support continued development of our in vitro model as a tool for predicting certain in vivo responses, and suggest that in some biological systems the capability to scavenge superoxide but produce excess H(2)O(2), as is known for CuZnSOD, may be potentially deleterious. Our results also show that the ability of catalase mimetics, like true catalases, to catalyse peroxidase reactions can complicate the interpretation of data obtained with certain fluorescent ROS-indicator dyes.


Asunto(s)
Antioxidantes/administración & dosificación , Catalasa/efectos de los fármacos , Neuronas/metabolismo , Tolerancia a Radiación/fisiología , Especies Reactivas de Oxígeno/metabolismo , Células Madre/metabolismo , Superóxido Dismutasa/efectos de los fármacos , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Masculino , Ratones , Neuronas/efectos de los fármacos , Neuronas/efectos de la radiación , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Estrés Oxidativo/efectos de la radiación , Tolerancia a Radiación/efectos de los fármacos , Ratas , Células Madre/efectos de los fármacos , Células Madre/efectos de la radiación
13.
Folia Neuropathol ; 53(1): 41-51, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25909874

RESUMEN

Trauma in spinal cord injury often results in massive damage to the white matter and in damage to myelin that results in a severe phagocyte-rich infiltration apparently directed at removing immunologically toxic myelin debris. In the epidural balloon crush injury to the rat cranial thoracic spinal cord, the dorsal column was crushed, which at one week post-op resulted in its obliteration by a severe infiltration by a virtually pure population of macrophages that internalized all damaged myelin. A week-long subdural infusion of dexamethasone, a stable synthetic corticosteroid, resulted in remarkable inhibition of the macrophage infiltration of the crush cavity and in the lack of removal of myelin debris by phagocytosis. In this study we demonstrated that spinal cord injury results in a severe inflammatory response directed at massively damaged myelin, and we inhibited this response with a subdural infusion of a powerful anti-inflammatory drug, dexamethasone.


Asunto(s)
Dexametasona/administración & dosificación , Modelos Animales de Enfermedad , Mielitis/prevención & control , Fibras Nerviosas Mielínicas/efectos de los fármacos , Traumatismos de la Médula Espinal/tratamiento farmacológico , Espacio Subdural , Animales , Femenino , Masculino , Mielitis/etiología , Mielitis/patología , Fibras Nerviosas Mielínicas/patología , Ratas , Ratas Long-Evans , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/patología
14.
Neuroscience ; 119(1): 181-91, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12763079

RESUMEN

We have assessed the expression and kinetics of voltage-gated K(+) currents in cardiac dorsal root ganglion (DRG) neurons in rats. The neurons were labelled by prior injection of a fluorescent tracer into the pericardial sack. Ninety-nine neurons were labelled: 24% small (diameter<30 microm), 66% medium-sized (diameter 30 microm>.48 microm) and 10% large (>48 microm) neurons. Current recordings were performed in small and medium-sized neurons. The kinetic and pharmacological properties of K(+) currents recorded in these two groups of neurons were identical and the results obtained from these neurons were pooled. Three types of K(+) currents were identified:a) I(As), slowly activating and slowly time-dependently inactivating current, with V(1/2) of activation -18 mV and current density at +30 mV equal to 164 pA/pF, V(1/2) of inactivation at -84 mV. b) I(Af) current, fast activating and fast time-dependently inactivating current, with V(1/2) of activation at two mV and current density at +30 mV equal to 180 pA/pF, V(1/2) of inactivation at -26 mV. At resting membrane potential I(As) was inactivated, whilst I(Af), available for activation. The I(As) currents recovered faster from inactivation than I(Af) current. 4-Aminopiridyne (4-AP) (10 mM) and tetraethylammonium (TEA) (100 mM) produced 98% and 92% reductions of I(Af) current, respectively and 27% and 66% of I(As) current, respectively. c) The I(K) current that did not inactivate over time. Its V(1/2) of activation was -11 mV and its current density equaled 67 pA/pF. This current was inhibited by 95% (100 mM) TEA, whilst 4-AP (10 mM) produced its 23% reduction. All three K(+) current components (I(As), I(Af) and I(K)) were present in every small and medium-sized cardiac DRG neuron. We suggest that at hyperpolarized membrane potentials the fast reactivating I(As) current limits the action potential firing rate of cardiac DRG neurons. At depolarised membrane potentials the I(Af) K(+) current, the reactivation of which is very slow, does not oppose the firing rate of cardiac DRG neurons.


Asunto(s)
Ganglios Espinales/citología , Corazón/inervación , Neuronas/fisiología , Canales de Potasio con Entrada de Voltaje/fisiología , 4-Aminopiridina/farmacología , Amidinas/farmacocinética , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Conductividad Eléctrica , Electrofisiología , Colorantes Fluorescentes/farmacocinética , Cinética , Masculino , Potenciales de la Membrana/fisiología , Miocardio/metabolismo , Técnicas de Placa-Clamp/métodos , Bloqueadores de los Canales de Potasio/farmacología , Ratas , Ratas Wistar , Tetraetilamonio/farmacología , Factores de Tiempo
15.
Brain Res ; 857(1-2): 327-36, 2000 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-10700587

RESUMEN

The activity of muscular and cutaneous sympathetic neurones has been shown to be differentially regulated. The differences may partially stem from the different ionic channel expression and current kinetics in these neurones, particularly that of Na(+) channels, which play a critical role in action potential generation and modulation of neuronal excitability. The whole cell patch-clamp technique was used to compare the kinetic properties of Na(+) currents in two groups of sympathetic neurones identified by the fluorescent tracer Fast Blue: putative muscular sympathetic neurones (PMSN) and putative cutaneous sympathetic neurones (PSSN). The tracer was injected into the muscular part of the diaphragm (to mark PMSN) and into the skin of the ear (to mark PSSN). Both kinds of neurones expressed fast activating, fast inactivating, voltage dependent and TTX sensitive Na(+) currents. However, the electrical characteristics of the cells were markedly different: (1) The capacitance of PMSN (21.7 pF) was larger than PSSN (12.7 pF). Maximum current in PMSN (3.1 nA) was also larger than in PSSN (2.0 nA). Calculated current density was smaller in PMSN (148.0 pA/pF) than in PSSN (181.1 pA/pF). Slope conductance was larger in PMSN compared to PSSN (102.7 nS and 73.6 nS respectively). (2) V(1/2) of activation for PMSN (-20.9 mV) was more negative than the potential recorded for PSSN (-16.7 mV); the slope factors were not different. (3) V(1/2) for inactivation was more negative for PMSN than for PSSN (-66.3 vs. -60.8 mV); again, the slope factors for inactivation were not different. (4) The rate of recovery from inactivation could be described by the sum of two exponential functions. In PMSN the fast and slow recovery exponential factors tau(f) and tau(s) were 12.6 (66%) and 83.9 (34%) ms, while in PSSN they were shorter and equalled 8.2 (62%) and 41.9 (38%) ms, respectively. We conclude that the Na(+) currents of PMSN and PSSN have different kinetic properties.


Asunto(s)
Vías Eferentes/citología , Vías Eferentes/fisiología , Ganglios Simpáticos/citología , Ganglios Simpáticos/fisiología , Músculo Esquelético/inervación , Músculo Esquelético/fisiología , Neuronas/citología , Neuronas/fisiología , Piel/inervación , Piel/metabolismo , Canales de Sodio/fisiología , Fibras Simpáticas Posganglionares/citología , Fibras Simpáticas Posganglionares/fisiología , Amidinas , Animales , Técnicas de Cultivo de Célula , Colorantes Fluorescentes , Masculino , Técnicas de Placa-Clamp , Ratas , Ratas Wistar
16.
Brain Res ; 873(1): 173-80, 2000 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-10915828

RESUMEN

Voltage-gated Ca(2+) channels are expressed in neurones and greatly influence neuronal activity by activating Ca(2+)-dependent K(+) channels. The whole cell patch-clamp technique was used to compare the kinetic and pharmacological properties of voltage-dependent Ca(2+) currents in two groups of sympathetic neurones identified by the fluorescent tracer Fast Blue: putative muscular sympathetic neurones (MSN) and putative cutaneous sympathetic neurones (CSN). The tracer was injected into the muscular part of the diaphragm (to mark MSN) and into the skin of the ear (to mark CSN). The capacitance of MSN (23.0 pF) was larger than the capacitance of CSN (12.6 pF). The maximum current in MSN (1.3 nA) was also larger than in CSN (0.93 nA). However, the current density was larger in CSN (77. 3 pA/pF) than in MSN (57.7 pA/pF) and the current activation rate was faster in CSN (0.27 nA/ms) than in MSN (0.19 nA/ms). V(1/2) and slope factors of activation and inactivation were not significantly different for MSN and CSN. The majority of Ca(2+) current was available for activation in both categories of neurones at resting membrane potential. Ca(2+) currents in MSN and CSN were blocked by nifedipine (7.0 and 3.6%, respectively), omega-Agatoxin-IVA (23.0 and 25.6%, respectively) and omega-conotoxin-GVIA (67.0 and 65.1%, respectively). We found that CSN are twice as small, have higher Ca(2+) current density and their Ca(2+) activation rate is faster in comparison to MSN. Such properties may lead to faster rise of Ca(2+) concentration in the cytoplasm of the CSN comparing to MSN and more effectively dampen their activity due to more effective activation of Ca(2+)-dependent K(+) current. Both kinds of neurones express high proportion of N and P/Q Ca(2+) current.


Asunto(s)
Calcio/fisiología , Ganglios Simpáticos/fisiología , Músculo Esquelético/inervación , Neuronas/fisiología , Piel/inervación , Transmisión Sináptica/fisiología , Animales , Bloqueadores de los Canales de Calcio/farmacología , Conductividad Eléctrica , Ganglios Simpáticos/citología , Homeostasis , Cinética , Masculino , Fenómenos Fisiológicos del Sistema Nervioso , Neuronas/efectos de los fármacos , Nifedipino/farmacología , Técnicas de Placa-Clamp , Ratas , Ratas Wistar , omega-Agatoxina IVA/farmacología , omega-Conotoxina GVIA/farmacología
17.
Neurosci Lett ; 359(1-2): 53-6, 2004 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-15050710

RESUMEN

Voltage-gated Na+ currents were recorded from anatomically identified postganglionic muscular sympathetic neurons without and with ATP and GTP in the intracellular solution. The main findings of the study were that cells without ATP and GTP in the intracellular solution express a higher amplitude and greater density of voltage-gated Na+ current, and their Na+ current activates faster and also inactivates faster time dependently. The current is also steady-state inactivated to a lesser degree and recovers from inactivation more slowly in cells without added ATP and GTP. These findings suggest that the presence of ATP and GTP, substrates for channel phosphorylation, changes the kinetic properties of Na+ currents.


Asunto(s)
Adenosina Trifosfato/fisiología , Guanosina Trifosfato/fisiología , Líquido Intracelular/fisiología , Canales de Sodio/fisiología , Fibras Simpáticas Posganglionares/fisiología , Animales , Músculo Esquelético/fisiología , Neuronas/fisiología , Ratas , Ganglio Cervical Superior/fisiología
18.
Ginekol Pol ; 72(12): 1073-8, 2001 Dec.
Artículo en Polaco | MEDLINE | ID: mdl-11883212

RESUMEN

The purpose of this study was to characterize prooxidant-antioxidant balance in patients with different clinical types of spontaneous abortion. Sixty previously untreated, pregnant women aged 16-38 years were included into this study. The gestational age ranged from 8 to 12 weeks. Patients were divided into three groups of 20 subjects each. The first group consisted of patients with inevitable abortion. The second group included women with threatened abortion in whom pregnancy was maintained until term. The control group consisted of women with uncomplicated pregnancy. In all the patients venous blood was collected immediately after the diagnosis was settled and before the treatment was commenced. Two biochemical markers of oxidative stress were quantified, namely: lipid peroxides (LP) using spectrophotometric TBARS method and total antioxidant status (TAS) by means of the commercially available kits (TAS: Randox Laboratories Ltd., U.K.). The obtained results indicate that spontaneous abortion is accompanied by a profound disruption of the prooxidant-antioxidant homeostasis towards oxidative stress.


Asunto(s)
Aborto Espontáneo/sangre , Antioxidantes/metabolismo , Peróxidos Lipídicos/sangre , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Amenaza de Aborto/sangre , Adolescente , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Embarazo , Primer Trimestre del Embarazo , Espectrofotometría , Estadísticas no Paramétricas
19.
Ginekol Pol ; 70(3): 135-40, 1999 Mar.
Artículo en Polaco | MEDLINE | ID: mdl-10390915

RESUMEN

OBJECTIVE: To estimate the concentration of malonyldialdehyde (MDA) and total antioxidant status in the peritoneal fluid (PF) of patients with unexplained infertility (UI) and infertile women with minimal and mild endometriosis. MATERIALS AND METHODS: PF was obtained during laparoscopy from 8 women with UI, 12 infertile women with endometriosis (I degree and II degrees rAFS) and 10 women with benign noninflammatory ovarian tumours. All laparoscopies were performed in the follicular phase of the cycle. MDA concentration was measured according to Ledwozyw method, TAS was measured spectrophotometrically using RANDOX diagnostic reagent system. RESULTS: We found significantly higher concentration of MDA in PF from both patients with UI (p = 0.03) and with endometriosis (p = 0.046) compared to the control group. TAS was significantly (p = 0.027) higher in PF of women with UI but did not differ significantly (p = 0.49) between patients with endometriosis and controls. CONCLUSIONS: Our results show that an imbalance between lipid peroxides and the antioxidant system in PF environment may be one of the main factors responsible for the UI. In the group with endometriosis a marginally significant difference in MDA levels, no significant differences in TAS and data from the literature, suggest that accelerated lipid peroxidation in PF doesn't appear to play a role in the endometriosis associated infertility.


Asunto(s)
Antioxidantes/análisis , Líquido Ascítico/química , Infertilidad Femenina/diagnóstico , Malondialdehído/análisis , Adulto , Endometriosis/complicaciones , Femenino , Humanos , Infertilidad Femenina/complicaciones , Laparotomía/métodos , Peroxidación de Lípido/fisiología , Neoplasias Ováricas/complicaciones
20.
Ginekol Pol ; 69(12): 895-901, 1998 Dec.
Artículo en Polaco | MEDLINE | ID: mdl-10224748

RESUMEN

The authors compared the concentrations of conjugated diens (CD), lipid hydroperoxides (HEPTE) and malonyl dialdehyde (MDA), in blood serum and placental tissue of 15 parturients with pregnancy induced hypertension (PIH) and 15 normotensive controls matched for gestational age. The CD and HEPTE were measured according to the Ward method, and the MDA level was quantified by means of the Ledwozyw method. In the placental homogenates of women with gestosis, levels of lipoperoxidation products were not significantly changed in comparison to the control group. In patients with PIH, the blood serum concentrations of CD, HEPTE and MDA exceeded the control values by 48.28%, 169.47% and 57.59%, respectively (p < 0.001). Lipid peroxidation seems to play an important role in pathogenesis of the pregnancy associated hypertensive disorders.


Asunto(s)
Hipertensión/sangre , Peroxidación de Lípido/fisiología , Placenta/química , Complicaciones del Embarazo/sangre , Adulto , Femenino , Humanos , Embarazo , Tercer Trimestre del Embarazo/fisiología
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