Role of Rab27 in synaptic transmission at the squid giant synapse

Small GTPase Rab is a member of a large family of Ras-related proteins, highly conserved in eukaryotic cells, and thought to regulate specific type(s) and/or specific step(s) in intracellular membrane trafficking. Given our interest in synaptic transmission, we addressed the possibility that Rab27 (a close isoform of Rab3) could be involved in cytosolic synaptic vesicle mobilization. Indeed, preterminal injection of a specific antibody against squid Rab27 (anti-sqRab27 antibody) combined with confocal microscopy demonstrated that Rab27 is present on squid synaptic vesicles. Electrophysiological study of injected synapses showed that the anti-sqRab27 antibody inhibited synaptic release in a stimulation-dependent manner without affecting presynaptic action potentials or inward Ca2+ current. This result was confirmed in in vitro synaptosomes by using total internal reflection fluorescence microscopy. Thus, synaptosomal Ca2+-stimulated release of FM1-43 dye was greatly impaired by intraterminal anti-sqRab27 antibody. Ultrastructural analysis of the injected giant preterminal further showed a reduced number of docked synaptic vesicles and an increase in nondocked vesicular profiles distant from the active zone. These results, taken together, indicate that Rab27 is primarily involved in the maturation of recycled vesicles and/or their transport to the presynaptic active zone in the squid giant synapse.

Indirect immune detection of ecdysone receptor (EcR) during the formation of DNA puffs in Bradysia hygida (Diptera, Sciaridae)

Gene amplification occurs in Bradysia hygida salivary glands, at the end of the fourth larval instar. The hormone 20-hydroxyecdysone (20E) triggers this process, which results in DNA puff formation. Amplified genes are activated in two distinct groups. The activity of the first group is dependent on high levels of 20E, while the second group needs low hormone levels. Consequently, the salivary glands of B. hygida constitute an interesting biological model to study how 20E, and its receptors, affect gene amplification and activity. We produced polyclonal antibodies against B. hygida EcR (BhEcR). In western blots a polypeptide of about 66 kDa was detected in salivary gland extracts. The antibodies were also used for indirect immune-localization of BhEcR in polytene chromosomes. RNA-polymerase II was also immune-detected. We did not detect the receptor in chromosome C where the first and second groups of DNA puffs form during DNA puff anlage formation, but it was present during puff expansion. During the active phase of both groups of DNA puffs, RNA polymerase II co-localized with BhEcR. After puff regression, these antigens were not detected. Apparently, EcR plays a direct role in the transcription of amplified genes, but its role in gene amplification remains enigmatic.

Some results on holomorphic generalized functions

In this note, we present three independent results within generalized complex analysis (in the Colombeau sense). The first of them deals with non-removable singularities; we construct a generalized function u on an open subset Omega of C(n), which is not a holomorphic generalized function on Omega but it is a holomorphic generalized function on Omega\S, where S is a hypersurface contained in Omega. The second result shows the existence of a holomorphic generalized function with prescribed values in the zero-set of a classical holomorphic function. The last result states the existence of a compactly supported solution to the (partial derivative) over bar operator.

Reliability and validity of the Brazilian-Portuguese version of the Burns Specific Pain Anxiety Scale (BSPAS)

Background: Pain and anxiety are a common problem in all recovery phases after a burn. The Burns Specific Pain Anxiety Scale (BSPAS) was proposed to assess anxiety in burn patients related to painful procedures. Objectives: To assess internal consistency, discriminative construct validity, dimensionality and convergent construct validity of the Brazilian-Portuguese version of the Burns Specific Pain Anxiety Scale. Design: In this cross-sectional study, the original version of the BSPAS, adapted into Brazilian Portuguese, was tested for internal consistency (Cronbach`s Alpha), discriminative validity (related to total body surface area burned and sex), dimensionality (through factor analysis), and convergent construct validity (applying the Visual Analogue Scale for pain and State-Anxiety-STAI) in a group of 91 adult burn patients. Results: The adapted version of the BSPAS displayed a moderate and positive correlation with pain assessments: immediately before baths and dressings (r = 0.32; p < 0.001), immediately after baths and dressings (r = 0.31; p < 0.001) and during the relaxation period (r= 0.31; p < 0.001) and with anxiety assessments (r = 0.34; p < 0.001). No statistically significant differences were observed when comparing the mean of the adapted version of the BSPAS scores with sex (p = 0.194) and total body surface area burned (p = 0.162) (discriminative validity). The principal components analysis applied to our sample seems to confirm anxiety as one single domain of the Brazilian-Portuguese version of the BSPAS. Cronbach`s Alpha showed high internal consistency of the adapted version of the scale (0.90). Conclusion: The Brazilian-Portuguese version of the BSPAS 9-items has shown statically acceptable levels of reliability and validity for pain-related anxiety evaluation in burn patients. This scale can be used to assess nursing interventions aimed at decreasing pain and anxiety related to the performance of painful procedures. (c) 2010 Elsevier Ltd. All rights reserved.

Absence of pathological scarring in the donor site of the scalp in burns: An analysis of 295 cases

Aim: This study aims to describe the incidence of complications on scalp from which a thin split-skin graft was harvested (0.005-0.007 in.) of the donor site in children and adult burn victims. Methods: We reviewed the medical records of 295 burn patients admitted in the Burn Unit of the Clinical Hospital of the Faculty of Medicine of Ribeirao Preto, from January 1998 to December 2007, whose scalps were used as donor site for grafts. Skin-graft thickness varied from 0.005 in. to 0.007 in. The occurrence of pathological healing was evaluated clinically and the time of epithelisation by the main surgeon and a plastic surgeon or a staff nurse. Results: Of the 295 patients whose scalps were used as donor site, 274 were followed from 6 months to 10 years after the procedure (median 18.2 months). Twenty-one patients were lost to follow-up in the first 6 months. No hypertrophic scarring or keloids on the donor site was observed. Five patients (1.82%) presented with folliculitis and two of them were evaluated with small areas of alopecia (0.7%), treated with resection of these areas and primary suture. The average time of epithelisation of the donor site was 7 days. Conclusion: The harvest of thinner split graft from the scalp is a safe procedure. (C) 2009 Elsevier Ltd and ISBI. All rights reserved.