Bronchoalveolar lavage findings suggest two different forms of childhood asthma

The biochemical basis for the functional heterogeneity of human blood platelets was investigated in terms of protein phosphorylation, cytoplasmic calcium ([Ca2+]i), the ratio of 46 and 50 kDa vasodilator-stimulated protein (VASP), and GTP-binding proteins (G-proteins). Platelets were fractionated by density. Comparing resting low-density platelets (LDP) to high-density platelets (HDP) revealed higher phosphorylation of proteins in the 47, 31, and 24 kDa ranges. A higher phosphorylation of the 20 kDa protein in LDP compared to HDP was related to an enhanced [Ca2+]i, an increased ADP-ribosylation of the inhibitory G-protein (G(i alpha1-3)) and rhoA, and a decreased ADP-ribosylation of the stimulatory G-protein (G(s alpha)). The differences in the ribosylation patterns of the subpopulations were not influenced by thrombin stimulation or exposure to prostaglandin E1 (PGE1). An 18 kDa phosphoprotein was more highly phosphorylated in resting HDP than in LDP. Thrombin exposure caused dephosphorylation of the 18 kDa phosphoprotein in the HDP, but generally increased phosphorylation of both HDP and LDP in the 47, 31, 24, and 20 kDa bands. Preincubation with prostaglandin E1 or sodium nitroprusside diminished the subsequent thrombin-induced increase in phosphorylation, particularly in HDP. In unstimulated HDP, the 50 kDa VASP phospho form was enhanced, whereas in unstimulated LDP the 46 kDa VASP dephospho form was increased. Our findings suggest that the functional heterogeneity of platelets is partly derived from differences in signal transduction mechanisms reflected in varying phosphoprotein patterns and G-protein properties of platelet stimulatory and inhibitory pathways.     

Adenoid cystic carcinoma of the lacrimal gland simulating a dermoid cyst in a 9-year-old boy

Adenoid cystic carcinoma of the lacrimal gland is a malignant neoplasm that is generally found in adults and is usually managed by orbital exenteration and supplemental external beam irradiation or chemotherapy. A recent report has suggested that the tumor may have a less malignant course in children. We describe a case of adenoid cystic carcinoma of the lacrimal gland that simulated a dermoid cyst clinically and radiographically in a 9-year-old boy. The patient was treated with local surgical resection of the mass, followed by orbital plaque brachytherapy. Based on a review of the literature and our recent experience, the advisability of a more conservative approach to this tumor in selected cases is discussed. Although no prognostic conclusions can be drawn on the basis of a single case report with short follow-up, the relatively earlier detection of this tumor made possible by modern orbital imaging studies may allow total removal at an earlier stage and prevent orbital exenteration in a patient with normal vision. Recent developments suggest that there may be a basis for reassessing the advisability of a radical approach to the management of adenoid cystic carcinoma of the lacrimal gland in selected cases.     

A cytokinesis checkpoint requiring the yeast homologue of an APC-binding protein

Checkpoint controls ensure that events of the cell-division cycle are completed with fidelity and in the correct order. In budding yeast with a mutation in the motor protein dynein, the mitotic spindle is often misaligned and therefore slow to enter the neck between mother cell and budding daughter cell. When this occurs, cytokinesis (division of the cytoplasm into two) is delayed until the spindle is properly positioned. Here we describe mutations that abolish this delay, indicating the existence of a new checkpoint mechanism. One mutation lies in the gene encoding the yeast homologue of EB1, a human protein that binds the adenomatous polyposis coli (APC) protein, a tumour suppressor. EB1 is located on microtubules of the mitotic spindle and is important in spindle assembly. EB1 may therefore, by associating with microtubules, contribute to the sensor mechanism that activates the checkpoint. Another mutation affects Stt4, a phosphatidylinositol-4-OH kinase. Cold temperature is an environmental stimulus that causes misalignment of the mitotic spindle in yeast and appears to activate this checkpoint mechanism.     

Fatal asphyxiations in children involving drawstrings on clothing

Injuries account for more deaths and hospital admissions among children and adolescents than all diseases combined. The authors report two deaths by asphyxiation that resulted from drawstrings on the children's clothing becoming entangled on slides. Although such incidents are not common, they are preventable. The authors urge physicians to counsel parents and guardians to remove drawstrings from children's clothing, and they call upon the government and the clothing industry to work toward improving the safety standards for the design, manufacture and importation of children's clothing and banning the sale of children's clothing with drawstrings in Canada. In addition, they provide several resources for readers interested in helping reduce playground hazards in their communities.     

Layer double hydroxide and sodium montmorillonite multilayer coatings for the flammability reduction of flexible polyurethane foams

Flexible polyurethane foam (PUF) is coated by layer‐by‐layer (LbL) assembly using branched polyethyleneimine (BPEI), poly(acrylic acid) (PAA), and two different charged nanoparticles, such as sodium montmorillonite (Na‐MMT) and layered double hydroxide (LDH). Three different deposition strategies, that is, bilayer, trilayer, and quadlayer, exhibit different coating growth, morphology, and flammability properties. Changing the nanosheet from LDH to MMT dramatically alter the coating mass for the same number of layers. A five bilayer PAA/BPEI+LDH coating reduced the peak heat release rate by 40% and the average heat release rate by 70%, which is two times more effective than commercial fire retardants (FRs) and other LbL‐FR coatings for PUF. MMT and LDH mixed multilayers resulted in effective flame‐retardant coatings with less coating mass by manipulating the deposition strategy. This study manifests the flexibility of LbL to fine‐tune flammability reduction by switching the coating weight gains, which is significant to accelerate the development of other LbL coating regardless of the intended applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41767.     

Innovation in clean-room construction: a case study of co-operation between firms

This study examines partnering between a large client, multinational contractors and specialist suppliers, and local subcontractors involved in a project to construct clean room facilities. An ethnographic approach is used, which demonstrates the changing attitudes, values and the new working arrangements that emerged. The social bond of a ‘construction challenge’ was the basis of trust and sharing risk in a ‘quasi-fixed network’. In place of formal contracts, ongoing bargaining and continuous negotiation took place. However, the client was seen to dominate the construction process. Shared workspaces or ‘liminal zones’, betwixt and between firms, were created to allow collaboration. These are argued to be a practical organizational approach to sharing information and co-ordinating inter-firm activities. Among trades, agreements were struck to exchange training and apprenticeships for allowing foreign specialists and equipment to be imported by the high-purity gas supplier. Liminal zones appear to function as on-the-job classrooms for rapidly training workers in unfamiliar construction techniques and systems.     

Darwin on race, gender, and culture.

Darwin's theories of natural selection and sexual selection are significant scientific achievements, although his understanding of race and gender was defined and limited by his own life circumstances and the sociohistorical context within which he worked. This article considers the ways in which race, gender, and culture were represented and explained by Darwin and the ways in which his observations and opinions on gender and race were taken up by others and, more often than not, misapplied. Whereas the challenge of race (for Darwin) was to demonstrate the fundamental similarity and, hence, the common origin, of human races, the challenge of gender (for Darwin) was to identify a mechanism that could account for differences between women and men that, to him, were obvious, fundamental, and significant. The article concludes by considering the implications of Darwin's views for contemporary scientific psychology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)