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Microvilli appear to represent the first step in actin bundle formation in Drosophila bristles.
J Cell Sci. 2004 Jul 15; 117(Pt 16): 3531-8Tilney LG, Connelly PS, Guild GMDuring bristle development the emerging bristle shaft, socket cell, and the apical surface of thoracic epithelial cells form tiny protuberances or pimples that contain electron-dense material located on the cytoplasmic surface of the pimple tip. In a few cases short actin filaments extend from this material into the cortical cytoplasm. When cultured in the presence of jasplakinolide, an agent that prevents filament disassembly, pimples elongate to form microvilli containing a core of crosslinked filaments. Emerging-bristle mutants delay cortical bundle formation and are aggregated by forked protein crossbridges. Using these mutants and enhancing core bundle formation with jasplakinolide we found that microvillar formation represents the first stage in the morphogenesis of much larger actin bundles in Drosophila bristle shaft cells. Evidence is presented showing that socket cells do not contain forked protein crossbridges, a fact that may explain why cortical bundles only appear in bristle shaft cells. Furthermore, as pimples and microvilli form in the absence of both forked and fascin crossbridges, we also conclude that neither of these crossbridges account for core bundle formation in microvilli, but there must exist a third, as yet unidentified crossbridge in this system. Immunocytochemisty suggested that this new crossbridge is not Drosophila villin. Finally, ultrastructural comparisons suggest that microspikes and microvilli form very differently.
Removal of copper from aqueous solution using newspaper pulp as an adsorbent.
J Hazard Mater. 2008 Nov 30; 159(2-3): 396-403Chakravarty S, Pimple S, Chaturvedi HT, Singh S, Gupta KKNewspaper pulp was found to be a potential adsorbent for removal of copper from aqueous medium. Detail adsorption study of Cu on newspaper pulp was investigated. Batch adsorption study was carried out as a function of contact time, adsorbent dose, temperature (303-323 K). The experimental data was analyzed using Freundlich, Langmuir, Dubinin-Radushkevich (D-R) and Redlich-Peterson (R-P) isotherm models. It was found that Freundlich, Langmuir and R-P models fitted well. pH variation study revealed that the adsorption increased with increase in pH of the solution. Maximum loading capacity was found to be 30 mg g(-1) at 20 mg L(-1) of initial Cu concentration. Adsorption data were analyzed using two kinetic models, Lagergren first order and pseudo second order. It was observed that pseudo second order represented the best correlation. Langmuir isotherm was used to obtain the thermodynamic parameters such as free energy (DeltaG degrees ), enthalpy (DeltaH degrees ) and entropy (DeltaS degrees ) of adsorption. The negative value of free energy and positive value of enthalpy change indicate that the adsorption of Cu on newspaper pulp is a spontaneous process and endothermic. The results of activation energy also confirmed that the adsorption of Cu on newspaper pulp is physical in nature. Present investigation emphasized that newspaper pulp may be utilized as a low cost adsorbent for copper removal.
Management of shoulder instability in a military population.
J R Army Med Corps. 2008 Mar; 154(1): 38-40Pimple MK, DaCosta A, Clasper JCOBJECTIVES: Recurrent instability is common after shoulder dislocation in the young, particularly those engaged in physical jobs or sport. The management of recurrent traumatic shoulder instability is predominantly operative. However, the best method of surgery i.e. open or arthroscopic is still a matter of debate. We have developed an algorithm to decide on the choice of surgery and the aim of this study is to report this and compare the two different groups of military patients. METHODS: A retrospective review of all shoulder stabilisations performed on military personnel, by a single surgeon, between August 2004 and August 2005 at a district general hospital serving both military and civilian population was undertaken. The presentation, clinical and operative findings were noted and compared in the groups treated by arthroscopic or open stabilisation. RESULTS: Using our protocol 39 shoulder stabilisations were performed in military personnel. Of the shoulders, 25 (64%) underwent arthroscopic and 14 (36%) underwent open stabilisation. The indication for surgery was more than 2 episodes of shoulder dislocation. Open surgery was found to be more common in those who had their first dislocation at a younger age. Bilateral shoulder laxity was the most common indication to choose the open method. Both open and arthroscopic stabilisation gave good results in the high demand military population. Only one patient had recurrent instability after arthroscopic procedure. However, this was not statistically significant when compared with open stabilisation.
Participation in biomedical research is an imperfect moral duty: a response to John Harris.
J Med Ethics. 2007 Jul; 33(7): 414-7Shapshay S, Pimple KDIn his paper "Scientific research is a moral duty", John Harris argues that individuals have a moral duty to participate in biomedical research by volunteering as research subjects. He supports his claim with reference to what he calls the principle of beneficence as embodied in the "rule of rescue" (the moral obligation to prevent serious harm), and the principle of fairness embodied in the prohibition on "free riding" (we are obliged to share the sacrifices that make possible social practices from which we benefit). His view that biomedical research is an important social good is agreed upon, but it is argued that Harris succeeds only in showing that such participation and support is a moral good, among many other moral goods, while failing to show that there is a moral duty to participate in biomedical research in particular. The flaws in Harris's arguments are detailed here, and it is shown that the principles of beneficence and fairness yield only a weaker discretionary or imperfect obligation to help others in need and to reciprocate for sacrifices that others have made for the public good. This obligation is discretionary in the sense that the individuals are free to choose when, where, and how to help others in need and reciprocate for earlier sacrifices. That Harris has not succeeded in claiming a special status for biomedical research among all other social goods is shown here.
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