Celia Cortez

Rio de Janeiro State University | UERJ · Departamento de Matemática Aplicada (APL)

The aim of this work was to study the interaction of sulpiride with human serum albumin (HSA) and bovine serum albumin (BSA) through the fluorescence quenching technique. As sulpiride molecules emit fluorescence, we have developed a simple mathematical model to discriminate the quencher fluorescence from the albumin fluorescence in the solution whe...

We present a refinement of our model describing the association between enzyme activity and histopathological lesions in the catfish, Sciades herzbergii from a polluted port. The fish were sampled from a port known to be contaminated with heavy metals and organic compounds and from a natural reserve in São Marcos Bay, Brazil. Two biomarkers, hepati...

We present a model for the electric potential profile across the membranes of neuronal cells. We considered the resting and action potential states, and analyzed the influence of fixed charges of the membrane on its electric potential, based on experimental values of membrane properties of the spinal ganglion neuron and the neuroblastoma cell. The...

Aptamers are short, single stranded oligonucleotide or peptide molecules that bind a specific target molecule and can be used for the delivery of therapeutic agents and/or for imaging and clinical diagnosis. Several works have been developed aiming at the production of aptamers and the study of their applications, but few results have been reported...

Objective: To present a revision on characteristics of electric brain activity accompanying the animal hypnosis, state induced in laboratory in mammals by means experimental manipulation, as well as on alterations found in EEG during hypnosis, aiming to find phylogenetic basis that could conduct us to the understanding of neural rudiments of the hy...

The interactions of two short aptamers to human and bovine serum albumins were studied by fluorescence spectroscopic techniques. Intrinsic fluorescence of BSA and HSA were measured by selectively exciting their tryptophan residues. Gradual quenching was observed by titration of both proteins with aptamers. Aptamers are oligonucleic acid or peptide...

Kallikrein-related peptidase 6 (KLK6) is an active serine protease that has been implicated in common pathologies, including neurodegenerative disorders such as Parkinson and Alzheimer disease and certain types of cancer. Antibodies, either polyclonal or monoclonal, that exhibit specificity for distinct members of the extended kallikrein family, in...

The aim of the work is to study the mechanisms of the interaction of risperidone with human and bovine serum albumins using the fluorescence quenching technique. Risperidone is an atypical antipsychotic drug used to treat many psychiatric disorders. We selectively excited the fluorescence of tryptophan residues with a 290 nm wavelength light, and o...

Recent studies demonstrate the importance of leptin in feeding behavior. The decreasing of the serum concentration of this hormone is directly related to the body fatty amount and provokes alterations in neuroendocrine axis, causing amenorrhea and hyperactivity, among others consequences. In this paper, a review of the main aspects interconnecting...

The objective of this study was to investigate structural changes in the penile corpus cavernosum of prepubertal chronically stressed rats. Eight Wistar rats were assigned into the stress group (SG) and were submitted to 2 hours of tube restraint daily, from the fourth to the ninth week of life. Another 7 rats were used as the control group (CG). A...

We have studied the behavior of the electric potential profile across the membrane of the ganglion neuron and the neuroblastoma cell. We considered the physicochemical conditions during the resting and action potential (AP) states of the neuronal cells, and analyzed the influence of the fixed charges of the membrane on the surface electric potentia...

This paper verifies the morphological changes induced by immobilization stress on the kidney of rats by using stereological methods. Fifteen 4-week-old Wistar male rats were randomly assigned to control (n = 7) and stressed (n = 8) groups. Stress stimuli were performed over 5 weeks by immobilization of the rats for 2 h daily in a rigid opaque plast...

We have modeled the electric potential profile, across the membranes of the ganglion neuron and neuroblastoma cells. We consi-dered the resting and action potential states, and analyzed the influence of fixed charges of the membrane on the electric potential of the surface of the membranes of these cells, based on experimental values of mem-brane p...

The objective of this study is to investigate the differences of acupuncture effect between the Zusanli (St.36) and Sanyinjiao (SP.6) points on the gastrointestinal-tract (GIT) segment performed by the bioavailability of 99mTc-sodium-pertechnetate (Na99mTcO4) in rats. Male Wistar rats (n = 21) were allocated into three groups of seven each. Group...

The interaction of methyl-parathion with serum and albumin of pacu, Piaractus mesopotamicus, was studied, using the fluorescence quenching technique. Pacu is a neo-tropical fish specie inhabitant of rivers from western regions of Brazil. Methyl-parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) is an organophosphorous pesticide still used in...

A study was performed on the effects of stimulation at Zusanli-point (ST.36) by electroacupuncture (EA) at two frequencies on the bioavailability of (99m)Tc-sodium pertechnetate (Na(99m)TcO(4)) in rats. Forty Wistar rats were divided into four groups: untreated control, treated by manual acupuncture at ST.36 bilaterally, treated by EA at 2 Hz at ST...

This paper presents a model for the circadian temporization system of mammals which associates the synchronization dynamics of coupling oscillators to a set of equations able to reproduce the synaptic characteristics of somatodendritic membrane of neurons. The circadian timing system is organized in a way to receive information from the external an...

The interaction of methyl-parathion with the albumin of Piaractus mesopotamicus (Holmberg 1887) (= pacu), a fish species typical of Brazilian rivers, was studied and the results compared with known values for human and bovine albumin obtained in an earlier investigation. Methyl-parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) is an organop...

Circadian timing is structured in such a way as to receive information from the external and internal environments, and its function is the timing organization of the physiological and behavioral processes in a circadian pattern. In mammals, the circadian timing system consists of a group of structures, which includes the suprachiasmatic nucleus (S...

We present interesting correlations between subjective scores of image complexity and a series of computational measurements of geometrical properties of presented images. A set of 49 images was applied as a systematic methodology to characterize the human perception of its complexity. The experiment requested subjects to assign scores (0-10) to ea...

A new application for the nuclear imaging techniques is the study of organic responses to stress. Neuroimaging techniques allow the assessment of brain activation changes in association with the metabolic responses to stress. In this paper, a review of general effects of the stress on organic activity is made, emphasizing important advances introdu...

With already demonstrated in previous work the equations that describe the space dependence of the electric potential are determined by the solution of the equation of Poisson-Boltzmann. In this work we consider these solutions for the membrane of the human neuron, using a model simplified for this structure considering the distribution of electrol...

To evaluate the effect of acupuncture combined with physiotherapy in comparison with acupuncture and physiotherapy performed alone in different parameters; pain intensity, muscle tension, functional disability and muscle strength in the treatment of tension neck syndrome (TNS). A prospective, comparative clinical trial. Acupuncture and Rehabilitati...

The potential profile for a model of squid axon membrane has been determined for two physiological states: resting and action states. The non-linear Poisson–Boltzmann equation has been solved by considering the volumetric charge densities due to charges dissolved in an electrolytic solution and fixed on both glycocalyx and cytoplasmatic proteins. R...

O envelhecimento constitui num processo de mudanças progressivas que vai desde o declínio fisiológico gradual ao aumento de doenças que acomete o organismo paralelamente. Este processo é acompanhado por déficit funcional progressivo de vários sistemas orgânicos no qual inclui o sistema musculoesquelético (SME). O objetivo deste estudo é apresentar...

Aging consists of a progressive changing process that leads to a gradual decline of physiological activities. The functional deficit of organic systems in which includes the musculoskeletal system (SME) are observed due to the aging. The aim of this study is to present a therapeutic approach that associates the Acupuncture to Kinesiotherapy, known...

We used a set of properties of the interactions among the spinal neurons in order to develop a computer model for a spinal reflex circuit. The model equations take into account the synaptic characteristics of the somatodendritic membrane of neurons in a morphofunctional unity of the spinal reflex activity. This model is based on the idea that the r...

The presence of oscillatory activity in motor command signals was demonstrated, and the possible existence of synchronous oscillatory activity within the sensorimotor system has been suggested. We adopted a set of 1000 coupled oscillators distributed on 10×1010×10 square lattice as a model of a central pattern generator. Each lattice element contai...

The aim of this work is to suggest a procedure to treat the Work Related Musculoskeletal Disorders (WRMD) through a combined therapeutic method that associates the acupuncture to kinesiotherapy during the rehabilitation, known as Kinetic Acupuncture (AC) (or Kinesioacupunture). It is a multidisciplinary therapeutic approach offering the advantage...

Esse trabalho apresenta uma proposta de tratamento para os Distúrbios Osteomusculares Relacionados com o Trabalho ou Lesões por Esforços Repetitivos (DORT/LER) através de um método terapêutico combinado que associa a Acupuntura à Cinesioterapia durante a reabilitação, conhecido como Acupuntura Cinética(AC) ou Cinesioacupuntura. É uma conduta multid...

The binding of chlorpromazine (CPZ) and hemin to bovine serum albumin was studied by the fluorescence quenching technique. CPZ is a widely used anti-psychotic drug that interacts with blood components, influences bioavailability, and affects function of several biomolecules. Hemin is an important ferric residue of hemoglobin that binds within the h...

Binding of chlorpromazine (CPZ) and hemin (Hmn) to human (HSA) and bovine (BSA) serum albumin was studied by fluorescence quenching technique. Intrinsic fluorescences of BSA and HSA were measured by selectively exciting their tryptophan residues. Gradual quenching was observed by titration of both proteins with CPZ and Hmn. CPZ is a widely used ant...

Methyl parathion (MP; O,O-dimethyl O-p-nitrophenyl phosphorothioate) is an organophosphorous compound still largely used in agriculture and fish hatcheries. This pesticide is not quite selective and is potentially toxic for both vertebrates and invertebrates. Its mechanism of acute toxicity is the inhibition of the enzyme acetylcholinesterase in ne...

SUMMARY: The present work investigates the corticoid action on the growth of the superior cervical ganglion of the rat and describes the cortisol effect during early stages of development. The study was based on morphometric and stereological analysis of the perikarya. Eight rats were treated intraperitoneally with cortisol (1mg/Kg/day) during 36 d...

Nervous system presents the grey and the white matter. The cord grey matter is the integrative area for the spinal reflexes and other motor functions. Sensory signals enter the cord through the sensory nerve roots, and after they have two different destinations: (a) the grey matter of the cord, where some sensory fibre or its collaterals terminate;...

Resumo: Com já demostrado em trabalho anterior as equações que descrevem a dependência espacial do potencial elétrico são determinadas pela solução da equação de Poisson-Boltzmann. Neste trabalho propomos essas soluções para a membrana do neurônio humano, utilizando um modelo simplificado para essa estrutura considerando a distribuição dos eletróli...