Dynasore puts a new spin on dynamin: a surprising dual role during vesicle formation

During clathrin-mediated endocytosis, dynamin promotes the formation of clathrin-coated vesicles, but its mode of action is unresolved. In a recent study, Macia and colleagues made use of dynasore, a dynamin-specific inhibitor, to show that dynamin plays a dual role in endocytosis: they confirmed that dynamin is involved in detaching fully formed coated pits from the membrane, and also propose a new role for dynamin earlier in the process at the point of invagination.     

Conserved signaling through vascular endothelial growth (VEGF) receptor family members in murine lymphatic endothelial cells

Lymphatic vessels guide interstitial fluid, modulate immune responses by regulating leukocyte and antigen trafficking to lymph nodes, and in a cancer setting enable tumor cells to track to regional lymph nodes. The aim of the study was to determine whether primary murine lymphatic endothelial cells (mLECs) show conserved vascular endothelial growth factor (VEGF) signaling pathways with human LECs (hLECs). LECs were successfully isolated from murine dermis and prostate. Similar to hLECs, vascular endothelial growth factor (VEGF) family ligands activated MAPK and pAkt intracellular signaling pathways in mLECs. We describe a robust protocol for isolation of mLECs which, by harnessing the power of transgenic and knockout mouse models, will be a useful tool to study how LEC phenotype contributes to alterations in lymphatic vessel formation and function.     

Changing pattern of sensitization in Croatia to aeroallergens in adult population referring to allergy clinic during a period of 15 years

Published data indicate that during the last decades there is a possible change in the pattern of sensitization to different aeroallergens in adult population with atopy. The aim of this investigation was based on the hypothesis that during last 15 years there has been a change in the structure of prevalence of sensitization to different aeroallergens in adult population of Zagreb and its surroundings with atopy. Medical records from outpatient allergy clinic were screened for the period 1991-2004. We included 794 patients during years 1991-1994, 814 patients during years 1995-1999, and 969 patients during years 2000-2004. Following data were analyzed: age, gender, education level, residence, referral diagnosis, dominant symptoms, results of skin-prick test (SPT), total and specific serum immunoglobulin E. As risk factors for allergic sensitization we determined the decade of birth (p < 0.0001), male gender (p < 0.008), level of education (p < 0.0001), and place of residence (p < 0.05). Proportion of sensitized individuals to pollen significantly increased from the period 1991-1994 towards 2000-2004 (p < 0.001 for the trend) with a significant increase in the proportion of sensitized individuals to weed pollen (p = 0.002 for the trend) while the proportion of sensitized to other two groups of pollen (grasses and trees) was not significantly different. A significant increase in the proportion of sensitized individuals was determined for sensitization to ragweed pollen (p = 0.004 for the trend), and to mugwort (p = 0.005 for the trend). Despite all its limitations primarily based on the selection bias the results of this study are conclusive about the significant change in the proportion of sensitization to different aeroallergens and different pollen groups and individual pollen species during the investigated 15-year time interval.     

Perforin expression after acute myocardial infarction--a pilot study

Perforin is an important mediator of inflammatory reactions. It is a quick-action cytotoxic mediator accumulated in the cytoplasmic granules of effector immunity cells (T lymphocytes, NK and NKT cells) which provide death signal in infected or transformed cells. Perforin-positive cells were previously detected in myocardial tissue during Trypanosoma cruzi infection and viral myocarditis while its role in chronic and progressive cardiovascular inflammatory disease such as atherosclerosis is almost completely unexplored. The perforin activity is also untested during acute coronary events that represent unexpected atherosclerotic complications due to the inflammatory destabilisation and atherosclerotic plaque rupture. The aim of this study was to investigate the presence of perforin, an important immunological inflammatory molecule in peripheral blood lymphocytes during the early period after acute myocardial infarction. We analyzed three subject groups: women with ST-segment elevation acute myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI), conservatively treated women with acute myocardial infarction without ST-segment elevation (NSTEMI) and a control group of healthy volunteers. The STEMI and NSTEMI groups did not basically differ in medication neither in levels of routine laboratory tests, while troponin I were significantly higher in the STEMI group. In the study, we detected an early decrease of perforin-positive lymphocytes in STEMI patients that were in contrast with their persisting elevation among NSTEMI patients. Despite greater myocardial necrosis in the STEMI group, results of this pilot-study indicated the prolonged perforin-mediated inflammatory response in patients with NSTEMI. This perforin down-regulation that follows the coronary interventional reperfusion in STEMI emphasized the possible anti-inflammatory role of primary PCI among patients with acute myocardial infarction. Given that the issue of routine primary PCI in NSTEMI is nowadays highly topical, the results we expect in the wake of this pilot study could demonstrate a significant impact on clinical practice. Further research is needed to confirm these results, compare the perforin-mediated activity to other inflammatory mediators in acute coronary events and to examine their impact on the long-term outcome.     

CT follow-up and clinical outcome in severe traumatic brain injury patients

Determining a patient's prognosis after severe traumatic brain injury remains difficult and complex. The purpose of the present study was following up patients with severe traumatic brain injury by correlating their clinical outcome and sequential computer tomography (CT) findings. We investigated 51 patients who survived the first year following an accident. All patients underwent successive CT examinations within a maximum period of 2 years. The patients' outcomes depended on the underlying brain damage and are presented by the Glasgow Outcome Scale. Based on the investigated data we concluded that the worst outcomes were experienced by patients with initial massive cerebral edema, extensive subdural hematoma and intraventricular hemorrhage, followed by stroke as subacute CT finding and cerebral atrophy as chronic finding visible at follow-up CT scans. The majority of lesions identified by CT scan were found in the frontal lobes, basal ganglia, and temporal lobes. We suggest that CT examination still represents a simple and useful tool in attempting to predict the clinical outcome in patients with severe traumatic brain injury.     

Personal identification by eyes

Identification of persons through the eyes is in the field of biometrical science. Many security systems are based on biometric methods of personal identification, to determine whether a person is presenting itself truly. The human eye contains an extremely large number of individual characteristics that make it particularly suitable for the process of identifying a person. Today, the eye is considered to be one of the most reliable body parts for human identification. Systems using iris recognition are among the most secure biometric systems.     

Gaze differences in processing pictures with emotional content

The International Affective Picture System (IAPS) is a set of standardized emotionally evocative color photographs developed by NIMH Center for Emotion and Attention at the University of Florida. It contains more than 900 emotional pictures indexed by emotional valence, arousal and dominance. However, when IAPS pictures were used in studying emotions with the event-related potentials, the results have shown a great deal of variation and inconsistency. In this research arousal and dominance of pictures were controlled while emotional valence was manipulated as 3 categories, pleasant, neutral and unpleasant pictures. Two experiments were conducted with an eye-tracker in order to determine to what the participants turn their gaze. Participants were 25 psychology students with normal vision. Every participant saw all pictures in color and same pictures in black/white version. This makes 200 analyzed units for color pictures and 200 for black and white pictures. Every picture was divided into figure and ground. Considering that perception can be influenced by color, edges, luminosity and contrast and since all those factors are collapsed on the pictures in IAPS, we compared color pictures with same black and white pictures. In first eye-tracking IAPS research we analyzed 12 emotional pictures and showed that participants have higher number of fixations for ground on neutral and unpleasant pictures and for figure on pleasant pictures. Second experiment was conducted with 4 sets of emotional complementary pictures (pleasant/unpleasant) which differ only on the content in the figure area and it was shown that participants were more focused on the figure area than on the ground area. Future ERP (event related potential) research with IAPS pictures should take into consideration these findings and to either choose pictures with blank ground or adjust pictures in the way that ground is blank. For the following experiments suggestion is to put emotional content in the figure area and to use different non complementary pictures to see if there is difference between different emotional categories.     

Autoregulation of neurogenesis by GDF11

In the olfactory epithelium (OE), generation of new neurons by neuronal progenitors is inhibited by a signal from neurons themselves. Here we provide evidence that this feedback inhibitory signal is growth and differentiation factor 11 (GDF11). Both GDF11 and its receptors are expressed by OE neurons and progenitors, and GDF11 inhibits OE neurogenesis in vitro by inducing p27(Kip1) and reversible cell cycle arrest in progenitors. Mice lacking functional GDF11 have more progenitors and neurons in the OE, whereas mice lacking follistatin, a GDF11 antagonist, show dramatically decreased neurogenesis. This negative autoregulatory action of GDF11 is strikingly like that of its homolog, GDF8/myostatin, in skeletal muscle, suggesting that similar strategies establish and maintain proper cell number during neural and muscular development.