Collagen or collagen-related peptide cause (Ca2+)i elevation and increased tyrosine phosphorylation in human megakaryocytes.

Since megakaryocytes are the cellular precursors of platelets we have investigated whether they share responses to platelet agonists, in particular collagen. Although previous studies have reported responses to thrombin in non-human megakaryocytes, through studies of single cell calcium responses and protein tyrosine-phosphorylation we demonstrate for the first time that both isolated human megakaryocytes and CD41/61-positive megakaryocytes derived in culture from CD34+ cells share responses to the platelet agonists collagen, collagen-related peptide and thrombin. The responses to either collagen or CRP were seen only in the most mature megakaryocytes and not in megakaryocyte-like cell lines, suggesting that the response to collagen is a characteristic developed late during megakaryocyte differentiation. These primary cells offer the opportunity to use many molecular and cellular techniques to study and manipulate signalling events in response to platelet receptor agonists, which cannot be performed in the small, anucleate platelet itself.

Forgetting as a consequence of retrieval: a meta-analytic review of retrieval-induced forgetting

Retrieving a subset of items can cause the forgetting of other items, a phenomenon referred to as retrieval-induced forgetting. According to some theorists, retrieval-induced forgetting is the consequence of an inhibitory mechanism that acts to reduce the accessibility of non-target items that interfere with the retrieval of target items. Other theorists argue that inhibition is unnecessary to account for retrieval-induced forgetting, contending instead that the phenomenon can be best explained by non-inhibitory mechanisms, such as strength-based competition or blocking. The current paper provides the first major meta-analysis of retrieval-induced forgetting, conducted with the primary purpose of quantitatively evaluating the multitude of findings that have been used to contrast these two theoretical viewpoints. The results largely supported inhibition accounts, but also provided some challenging evidence, with the nature of the results often varying as a function of how retrieval-induced forgetting was assessed. Implications for further research and theory development are discussed.

With an eye to academia or vocation? A draft to a research plan

There is a profound need to increase the quality and status of vocational education and train-ing (VET) and vocational education and training education – Teacher training (VTE-TT). As a consequence of several reforms the requirements of academic achievements in these different education systems are distinctly higher than before. These high ambitions cause problems and the actors in school and teacher education has got new challenges. Furthermore, vocational education teachers are supposed to prepare their pupils both to a pro-fessional career and to future academic studies. Accordingly, Vocational Education Teacher Trainers are supposed to prepare their students both to a career as vocational teachers and for further academic studies. This makes imprints in the field of VET and VTE-TT. The aim of this paper is to present a coming study about how actors in VET and VTE-TT think and act in relation to their changed assignment.

Cause related marketing-commercialism or altruism: Finding the balance?

The objective of this paper is to describe a framework of questions that may provide guidance as to whether a company (i.e., a for-profit organisation) should engage in Cause Related Marketing (CRM) or not. CRM is an  intriguing concept in which one finds a cause and intertwines one’s  marketing push to sell both the cause and one’s products. The reality is that some companies do focus solely on the profit returns from socially responsible ventures and others do not, therefore, a framework of questions are provided that may guide companies as to whether to pursue a CRM-relationship with a non-profit organisation (i.e., the cause).

Does screening high school students for psychological distress, deliberate self-harm, or suicidal ideation cause distress--and is it acceptable? An Australian-based study

Programs designed to detect students at risk of depression and suicidality have shown success (Shaffer et al., 2004). The current study sought to examine whether or not such a program was acceptable to participants and whether or not it caused distress. Participants were boys aged 14 to 16. Participants were assessed using an on-line questionnaire; acceptability was measured via postal questionnaire. Of 272 participants, 31 (11.4%) were considered at-risk; 13 required ongoing support, 8 of whom had not previously sought help. Overall screening did not appear to cause significant undue distress, although some differences were evident between at-risk and not at-risk students. All participants found the program acceptable. When conducted carefully, early detection programs can be an effective and acceptable method of identifying at-risk adolescents.

Why foreign savings fail to cause growth

Este artigo é uma formalização da crítica à estratégia do crescimento com poupança externa que um de seus autores vem sendo fazendo nos últimos anos. Apesar dos países de renda média serem pobres de capital, os déficits em conta corrente (poupança externa), financiado seja por empréstimos ou por investimentos externos diretos, não irá aumentar a taxa de acumulação de capital ou terá pouco impacto sobre ela, uma vez que os déficits de conta corrente estarão associados taxas de câmbio apreciadas, ordenados e salários aumentados artificialmente e altos níveis de consumo. Consequentemente, a taxa de substituição da poupança externa pela interna será relativamente alta, e o país será obrigado não a investir e crescer, mas a consumir. Apenas quando há grandes oportunidades de investimento, estimuladas por uma ampla diferença entre a taxa de lucro esperada e a taxa de juros de longo prazo, a propensão marginal ao consumo diminuirá suficientemente, a ponto de o lucro adicional originário do fluxo de capital estrangeiro ser usado para investimento, ao invés de para consumo. Neste caso especial, a taxa de substituição de poupança externa pela interna tenderá a ser menor e a poupança interna contribuirá positivamente para o crescimento

Does toxoplasmosis cause DNA damage? An evaluation in isogenic mice under normal diet or dietary restriction

Toxoplasmosis is an anthropozoonotic widespread disease, caused by the coccidian protozoan parasite Toxoplasma gondii. Since there are no data regarding the genotoxicity of the parasite in vivo, this study was designed to evaluate the genotoxic potential of the toxoplasmosis on isogenic mice with normal diet or under dietary restriction and submitted to a treatment with sulfonamide (375 mug/kg per day). DNA damage was assessed in peripheral blood, liver and brain cells using the comet assay (tail moment). The results for leucocytes showed increases in the mean tail moment in mice under dietary restriction; in infected mice under normal diet; in infected, sulfonamide-treated mice under normal diet; in infected mice under dietary restriction and in infected sulfonamide-treated mice under dietary restriction. In liver and brain cells, no statistically significant difference was observed for the tail moment. These results indicated that dietary restriction and T. gondii were able to induce DNA damage in peripheral blood cells, as detected by the comet assay. (C) 2004 Elsevier B.V. All rights reserved.

Reproductive biology and pollination mechanisms of Epidendrum secundum (Orchidaceae). Floral variation: a consequence of natural hybridization?

The phenology, flower morphology, pollination mechanism and reproductive biology of Epidendrum secundum were studied in a semi-deciduous forest at the Serra do Japi (SJ), and in the Atlantic rain forest of Picinguaba, both natural reserves in the State of Sao Paulo, southeastern Brazil. E. secundum flowers all year round, with a flowering peak between September and January. This species is either a lithophytic or terrestrial herb in the SJ, whereas, in Picinguaba, it grows mainly in disturbed areas along roadsides. E. secundum is pollinated by several species of diurnal Lepidoptera at both study sites. In Picinguaba, where E. secundum is sympatric with E. fulgens and both share the same pollinators, pollen transference between these two species was recorded. E. secundum is self-compatible but pollinator-dependent. It is inter-compatible with E. fulgens, producing fertile seeds. In contrast to the population of the SJ, in the Picinguaba region, floral morphology is quite variable among plants and some individuals present flowers with characteristics in-between both sympatric species, suggesting that natural hybridization occasionally occurs. The anthropogenic perturbation is probably the cause of the occurrence of E. secundum in the Picinguaba region, enabling its contact with E. fulgens.

Systemically alendronate was incorporated into dental tissues but did not cause morphological or mechanical changes in rats teeth

This study evaluated the effect of the systemic use of sodium alendronate in rats in vivo. Forty-five Wistar rats aged 36 to 42 days and weighing 200 to 230 g were randomly assigned to a control group (n = 20), which received distilled water, and an experimental group (n = 25), which received 2 weekly doses of 1 mg/kg of chemically pure sodium alendronate. The animals were killed after 60 days of treatment. The tibias were removed for analysis of bone mineral density by dual-energy X-ray absorptiometry (DXA). Then, the maxillary incisors were extracted for analysis of the mineralized dental tissues using fluorescence spectroscopy (FS), scanning electron microscopy (SEM), bright field microscopy (BFM), and cross-sectional microhardness (CSMH) testing. DXA and CSMH data were subjected to statistical analysis by Kruskal-Wallis test (5% significance level). The experimental group presented higher bone mineral density than the control group by DXA. FS analysis revealed presence of alendronate in the mineralized dental tissues of the specimens of the experimental group. Significant morphological differences were not found by SEM and BFM. Enamel and dentin (100 and 300 mu m from the dentinoenamel junction) CSMH data did not show significant difference between the control and experimental groups. Based on the obtained results, we conclude that while alendronate increased the bone mineral density and was incorporated into the mineralized dental tissues it did not cause significant alterations in the morphology and microhardness of rat incisor enamel and dentin. Microsc. Res. Tech. 75:12651271, 2012. (C) 2012 Wiley Periodicals, Inc.

All cause and disease specific mortality in patients with knee or hip osteoarthritis: population based cohort study

Objective To examine all cause and disease specific mortality in patients with osteoarthritis of the knee or hip. Design Population based cohort study. Setting General practices in the southwest of England. Participants 1163 patients aged 35 years or over with symptoms and radiological confirmation of osteoarthritis of the knee or hip. Main outcome measures Age and sex standardised mortality ratios and multivariable hazard ratios of death after a median of 14 years’ follow-up. Results Patients with osteoarthritis had excess all cause mortality compared with the general population (standardised mortality ratio 1.55, 95% confidence interval 1.41 to 1.70). Excess mortality was observed for all disease specific causes of death but was particularly pronounced for cardiovascular (standardised mortality ratio 1.71, 1.49 to 1.98) and dementia associated mortality (1.99, 1.22 to 3.25). Mortality increased with increasing age (P for trend <0.001), male sex (adjusted hazard ratio 1.59, 1.30 to 1.96), self reported history of diabetes (1.95, 1.31 to 2.90), cancer (2.28, 1.50 to 3.47), cardiovascular disease (1.38, 1.12 to 1.71), and walking disability (1.48, 1.17 to 1.86). However, little evidence existed for increased mortality associated with previous joint replacement, obesity, depression, chronic inflammatory disease, eye disease, or presence of pain at baseline. The more severe the walking disability, the higher was the risk of death (P for trend <0.001). Conclusion Patients with osteoarthritis are at higher risk of death compared with the general population. History of diabetes, cancer, or cardiovascular disease and the presence of walking disability are major risk factors. Management of patients with osteoarthritis and walking disability should focus on effective treatment of cardiovascular risk factors and comorbidities, as well as on increasing physical activity.

Neonatal macrocephaly: cerebral primitive neuroectodermal tumor or neuroblastoma as an infrequent cause--a case report and review of the literature

We report a male term newborn presenting with a congenital macrocephaly 3.5 standard deviations above the median, with a wide and tense anterior fontanel, splayed calvarial sutures, and muscular hypotonia. Antenatal head circumferences were repeatedly below the median. A postnatal head ultrasound showed a large right intracerebral mass with right lateral ventricle compression, right temporal horn dilation, and right frontal horn enlargement with lateral displacement. Additional imaging by computed tomography scan and magnetic resonance imaging was performed. A decompression was performed and histology, immunohistochemistry, and molecular biology supported the diagnosis of a primitive neuroectodermal tumor. A MYCN gene amplification assay remained negative. The incidence of neonatal brain tumors is between 1.4 and 4.1/100,000 live births. Their most common presentation is macrocephaly, hydrocephalus, stillbirth, or diagnosis by pre- or postnatal imaging. Although hydrocephaly and intra- or extracranial hemorrhage are the most frequent causes of congenital macrocephaly, this should be initially investigated by head ultrasound. A suspected malignancy will be confirmed by histopathology, immunohistochemistry, and molecular biology.

Puma indirectly activates Bax to cause apoptosis in the absence of Bid or Bim

Bcl-2 family members regulate apoptosis in response to cytokine withdrawal and a broad range of cytotoxic stimuli. Pro-apoptotic Bcl-2 family members Bax and Bak are essential for apoptosis triggered by interleukin-3 (IL-3) withdrawal in myeloid cells. The BH3-only protein Puma is critical for initiation of IL-3 withdrawal-induced apoptosis, because IL-3-deprived Puma(-/-) cells show increased capacity to form colonies when IL-3 is restored. To investigate the mechanisms of Puma-induced apoptosis and the interactions between Puma and other Bcl-2 family members, we expressed Puma under an inducible promoter in cells lacking one or more Bcl-2 family members. Puma rapidly induced apoptosis in cells lacking the BH3-only proteins, Bid and Bim. Puma expression resulted in activation of Bax, but Puma killing was not dependent on Bax or Bak alone as Puma readily induced apoptosis in cells lacking either of these proteins, but could not kill cells deficient for both. Puma co-immunoprecipitated with the anti-apoptotic Bcl-2 family members Bcl-x(L) and Mcl-1 but not with Bax or Bak. These data indicate that Puma functions, in the context of induced overexpression or IL-3 deprivation, primarily by binding and inactivating anti-apoptotic Bcl-2 family members.

[Intolerance as consequence of hyperreactivity]

Many patients complain about hyperreactivity of the skin or mucosal membranes, whereby rather harmless "triggers" lead to exaggerated reactions like running nose, bronchospasm, urticaria, etc. Most of these hyperreactivities have an underlying inflammation. It is important not to focus only on the triggers, but to look for the agent causing the inflammation and to avoid/treat it: elimination of the cause also eliminates the hyperreactivity. Four examples are presented where this cause--trigger model of hyperreactivity is illustrated (exercise induced asthma, pollen associated food allergy, flare-up reactions in drug allergy and hyperreactivity in chronic urticaria).

Persistence of Artemisia steppe in the Tangra Yumco Basin, west-central Tibet, China: despite or in consequence of Holocene lake-level changes?

The closed Tangra Yumco Basin underwent the strongest Quaternary lake-level changes so far recorded on the Tibetan Plateau. It was hitherto unknown what effect this had on local Holocene vegetation development. A 3.6-m sediment core from a recessional lake terrace at 4,700 m a.s.l., 160 m above the present lake level of Tangra Yumco, was studied to reconstruct Holocene flooding phases (sedimentology and ostracod analyses), vegetation dynamics and human influence (palynology, charcoal and coprophilous fungi analyses). Peat at the base of the profile proves lake level was below 4,700 m a.s.l. during the Pleistocene/Holocene transition. A deep-lake phase started after 11 cal ka BP, but the ostracod record indicates the level was not higher than similar to 4,720 m a.s.l. (180 m above present) and decreased gradually after the early Holocene maximum. Additional sediment ages from the basin suggest recession of Tangra Yumco from the coring site after 2.6 cal ka BP, with a shallow local lake persisting at the site until similar to 1 cal ka BP. The final peat formation indicates drier conditions thereafter. Persistence of Artemisia steppe during the Holocene lake high-stand resembles palynological records from west Tibet that indicate early Holocene aridity, in spite of high lake levels that may have resulted from meltwater input. Yet pollen assemblages indicate humidity closer to that of present potential forest areas near Lhasa, with 500-600 mm annual precipitation. Thus, the early mid-Holocene humidity was sufficient to sustain at least juniper forest, but Artemisia dominance persisted as a consequence of a combination of environmental disturbances such as (1) strong early Holocene climate fluctuations, (2) inundation of habitats suitable for forest, (3) extensive water surfaces that served as barriers to terrestrial diaspore transport from refuge areas, (4) strong erosion that denuded the non-flooded upper slopes and (5) increasing human influence since the late glacial.