Ultrastructural aspects ofTrypanosoma (Megatrypanum) freitasi in co-cultivation with mammalian cells

Cultures ofTrypanosoma (Megatrypanum) freitasi with L929 mouse fibroblasts at 27.5°C were examined by scanning and transmission electron microscopy in an attempt to clarify the processes of colony formation by the epimastigotes and of their attachment to substrata. It was seen that the flagellates occupy intercellular spaces and do not associate with intact fibroblasts. As the trypanosome population increases, ever larger portions of the substratum are cleared of fibroblasts and occupied by conglomerates of epimastigote colonies consisting of about a dozen organisms that attach to the substratum by their anterior extremities and form pyramidal clusters. Attachment of the epimastigotes involves the flagellar membrane, which becomes extraordinarily enlarged and assumes various aspects of broad sheets, filaments and loops over the substratum or along the flagellum, which exhibits a shortened axoneme. Desmosome or hemidesmosome plaques are present when the attachment takes place between membranes or between the membrane and the substratum.Supported by grants from CNPq and FINEP     

Voltage-gated potassium currents in rat vas deferens smooth muscle cells

Voltage-gated components of the outward current in single smooth muscle cells isolated from the epididymal part of the rat vas deferens were studied using amphotericin B perforated patch-clamp techniques. The complex kinetics of the net outward current elicited by positive voltage steps from -80 mV to +40 mV suggested the presence of several components. Bath application of 200 nM charybdotoxin, a potent blocker of large-conductance, Ca(2+)-dependent K(+) channels (BK(Ca)), reduced the current amplitude significantly. When BK(Ca) channels were suppressed, fast-inactivating (I(K,f)) and delayed rectifying (I(K,dr)) components of the outward current were identified. I(K,f) was characterized by fast kinetics of current decay, negative steady-state activation and inactivation dependencies and sensitivity to 4-aminopyridine with an apparent K(d) of 0.32 mM, properties similar to those of the A-type K(+) current. In contrast, I(K,dr) activated and inactivated at more positive potentials. The time constant of activation of I(K,dr) was voltage dependent with an e-fold decrease per 21 mV depolarization. I(K,dr) was inhibited by clofilium, a blocker of voltage-gated K(+) channels, with an IC(50) of 12 micro M and was not blocked by 5 mM 4-aminopyridine. The possible significance of the voltage-gated currents is discussed.     

Assessment of nose protector for sport activities: finite element analysis

Abstract – There has been a significant increase in the number of facial fractures stemming from sport activities in recent years, with the nasal bone one of the most affected structures. Researchers recommend the use of a nose protector, but there is no standardization regarding the material employed. Clinical experience has demonstrated that a combination of a flexible and rigid layer of ethylene vinyl acetate (EVA) offers both comfort and safety to practitioners of sports. The aim of the present study was the investigation into the stresses generated by the impact of a rigid body on the nasal bone on models with and without an EVA protector. For such, finite element analysis was employed. A craniofacial model was constructed from images obtained through computed tomography. The nose protector was modeled with two layers of EVA (1 mm of rigid EVA over 2 mm of flexible EVA), following the geometry of the soft tissue. Finite element analysis was performed using the LS Dyna program. The bone and rigid EVA were represented as elastic linear material, whereas the soft tissues and flexible EVA were represented as hyperelastic material. The impact from a rigid sphere on the frontal region of the face was simulated with a constant velocity of 20 m s^?1 for 9.1 μs. The model without the protector served as the control. The distribution of maximal stress of the facial bones was recorded. The maximal stress on the nasal bone surpassed the breaking limit of 0.13–0.34 MPa on the model without a protector, while remaining below this limit on the model with the protector. Thus, the nose protector made from both flexible and rigid EVA proved effective at protecting the nasal bones under high‐impact conditions.     

A comparison of histamine effects on the sympathetic neurotransmission of testicular capsule and rat vas deferens

Histamine is an important modulatory agent of the sympathetic neurotransmission, but its exact action on the testicular capsule or rat vas deferens is not fully understood. The present study sought to further investigate the functional effects of histamine on the neuronal and exogenous noradrenaline-induced contraction of the testicular capsule and rat vas deferens as well as to evaluate the contractile properties of this drug. The testicular capsule or vas deferens from Wistar rats, 3–4 months old, weighing 300–400 g, was isolated and mounted in organ baths for functional experiments. The results indicated that the neuronally evoked contraction of the testicular capsule was affected by histamine (10^?10 to 10^?8 M) with participation of inhibitory (H₃ receptors) and excitatory (H₁ receptors) receptors. Histamine (10^?7 to 10^?4 M) modulated the field-stimulated vas deferens by excitatory (H₂ receptors) and inhibitory (H₁ receptors) receptors. Histamine was able to decrease the tonic response for noradrenaline-induced contractions with participation of H₁ receptors (testicular capsule) and H₃ receptors (vas deferens) followed by nitric oxide generation. At high concentration, histamine exerts contractile effects in both tissues. In the testicular capsule, the histamine-induced contractions were related to H₁ receptor activation followed by release of prostaglandins. In contrast, the contractile effects of histamine in the vas deferens were related to H₂ receptor activation followed by release of catecholamines from sympathetic nerve endings. Therefore, our results indicate that histamine induced several effects on the sympathetic neurotransmission of rat testicular capsule and vas deferens. These effects are dependent on the concentration used and with participation of multiple histamine receptors.     

The re-humanization of the executive nurse's job: a focus on the spiritual dimension

This work synthesizes the authors' views on the damages to the development of human capital in health services, which are caused by the disregard to the human spiritual dimension. New administration paradigms related to the development of spirituality are pointed out. Considering that the spiritual dimension has a systemic nature and that, by means of ethics and esthetics, it harmonizes all of man's dimensions in his relationships with others, the authors aim at approaching the spiritual value as fundamental for the re-humanization of the managing nurse's job. They recommend the integration of the spiritual dimension to the daily work of such professional as a determinant factor for a new performance as well as an inductor for nurses' better personal and professional life quality.     

Colchicine for dermatologic diseases

The authors review all related to colchicine from its pharmacology to its usage in several skin diseases.     

Reflections on stress and burnout and their relationship with nursing

This bibliographic review aimed to differentiate between stress and Burnout and to establish their relationship with nursing work to support the understanding of psychical suffering at work. The study was based on the analysis and interpretation of articles, thesis and dissertations produced between 1990 and 2001. Although there is a consensus among the individuals on the existence of stress and burnout, there are several controversies surrounding these terms. These theories were created in the context of capitalist production increase. Stress refers to a personal tiring that interferes in the life of the person but not necessarily in his/her relationship with the work. Burnout is a syndrome involving negative attitudes and behaviors towards users, clients, organization and work. It is a gradual process of subjective experiences that result in practical and emotional problems to workers and organizations. Nursing work facilitates stress and burnout and causes suffering and illness among workers.     

Family dynamics, stages of the elderly with Alzheimer disease, and stages experienced by the family in relation to home care

A qualitative research carried out with relatives who take care of elderly people with Alzheimer disease, it aimed at describing the experiences of these family members in living with the elderly and analyzing aspects that interfere with the transformations of family dynamics since the onset of the disease. The concept of dialogical education was applied to produce data in the dynamics of creativity and sensitivity Subjects shared the reality of living with the diseased person in the most diverse situations of life, their feelings, their anguish, interpersonal relationship, their expectations and family members' strategies in home co-existence. It was commented that the different stages of the diseased person and his/her family members, respectively, even though not always coinciding, are interpenetrated, thus generating transformations and re-configuration in family dynamics.