Most cells enter mitosis once they have reached a defined size. In the fission yeast Schizosaccharomyces pombe, mitotic entry is orchestrated by a geometry-sensing mechanism that involves the ...Cdk1/Cdc2-inhibiting Wee1 kinase. The factors upstream of Wee1 gather together in interphase to form a characteristic medial and cortical belt of nodes. Nodes are also considered to be precursors of the cytokinesis contractile actomyosin ring (CAR). Here we describe a new component of the interphase nodes and cytokinesis rings, which we named Nod1. Consistent with its role in cell size control at division, nod1Δ cells were elongated and epistatic with regulators of Wee1. Through biochemical and localisation studies, we placed Nod1 in a complex with the Rho-guanine nucleotide exchange factor Gef2. Nod1 and Gef2 mutually recruited each other in nodes and Nod1 also assembles Gef2 in rings. Like gef2Δ, nod1Δ cells showed a mild displacement of their division plane and this phenotype was severely exacerbated when the parallel Polo kinase pathway was also compromised. We conclude that Nod1 specifies the division site by localising Gef2 to the mitotic cell middle. Previous work showed that Gef2 in turn anchors factors that control the spatio-temporal recruitment of the actin nucleation machinery. It is believed that the actin filaments originated from the nodes pull nodes together into a single contractile ring. Surprisingly however, we found that node proteins could form pre-ring helical filaments in a cdc12-112 mutant in which nucleation of the actin ring is impaired. Furthermore, the deletion of either nod1 or gef2 created an un-expected situation where different ring components were recruited sequentially rather than simultaneously. At later stages of cytokinesis, these various rings appeared inter-fitted rather than merged. This study brings a new slant to the understanding of CAR assembly and function.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction
Delirium is a frequent and serious complication of cardiac surgery. However, the knowledge regarding pathogenesis of postoperative delirium is limited.
Objectives
To investigate whether ...increased levels of monocyte chemoattractant protein-1 (MCP-1) and hyper-sensitive C-Reactive Protein (hsCRP) are associated with postoperative delirium in cardiac surgery patients.
Methods
Patients were examined and screened for major depressive disorder (MDD) and cognitive impairment one day preoperatively, using the Mini International Neuropsychiatric Interview and The Mini-Mental State Examination Test. Blood samples were collected pre- and postoperatively for hsCRP and chemokine levels. Following surgical interventions, the Confusion Assessment Method for the Intensive Care Unit and the Memorial Delirium Assessment Scale with the cut-off score 10 were used to diagnose delirium.
Results
Postoperative delirium screening was found positive in 34% (61 of 177) of patients. Both, pre- and postoperative hsCRP, and preoperative MCP-1 levels were associated with postoperative delirium in univariate comparisons; p=0.001; p=0.0004; p < 0.001, respectively. However, according to a multivariate stepwise logistic regression analysis only MCP-1 concentration raised before surgery was independently associated with postoperative delirium, and related to advancing age of participants (Spearman’s Rank Correlation 0.192; p=0.0103). According to ROC analysis, the most optimal cut-off for MCP-1 concentration in predicting the development of delirium was 371.81 ng/ml with sensitivity of 77.0% and specificity of 58.6%.
Conclusions
The present study suggests that raised preoperative MCP-1 concentration is independently associated with delirium after cardiac surgery. Preoperative monitoring of pro-inflammatory markers combined with regular surveillance may be helpful in the prediction and early detection of postoperative delirium in this patient group.
Introduction
Coronary-artery bypass graft (CABG) surgery is known to improve cardiac function and decrease mortality, albeit, this method of treatment is associated with a high risk of postoperative ...delirium. The pathophysiology of delirium after cardiac surgery is largely unknown.
Objectives
To investigate whether oxidative stress reflected by decreased preoperative and postoperative plasma antioxidant capacity (AC) is independently associated with delirium after cardiac surgery. Furthermore, to assess whether the association between AC and the level of soluble receptor for advanced glycation end-products (sRAGE) exists.
Methods
The patients were examined 1 day preoperatively with the Mini International Neuropsychiatric Interview and MMSE test to screen for depression, anxiety disorders, and for cognitive impairment, respectively. Blood samples for AC and sRAGE levels were collected both preopertively and postoperatively. The CAM ICU and MDAS were used within the first 5 days postoperatively to screen for a diagnosis of delirium.
Results
Postoperative delirium developed in 34% (61 of 177) of participants. Multivariate stepwise logistic regression analysis revealed that patients with low baseline AC are at significantly increased risk of developing delirium. Moreover, preoperative AC levels were inversly correlated with postoperative sRAGE concentrations (Spearman’s Rank Correlation -0.198; p<0.05). The most optimal cutoff values of the preoperative and postoperative AC that predict the development of delirium were 1.720 mM and 1.893 mM, respectively.
Conclusions
Decreased plasma AC levels are associated with delirium after cardiac surgery and inversly correlated with post-surgery sRAGE concentration. This may be an important pathophysiological consideration in the increased risk of postoperative delirium seen in cardiac surgery patients.
This study was undertaken to investigate the effect of severe plastic deformation (SPD) by extrusion combined with reversible torsion (KoBo) method on microstructure and mechanical properties of ...Al-5Cu and Al-25Cu alloys. The extrusion combined with reversible torsion was carried out using reduction coefficient of λ = 30 and λ = 98. In this work, the microstructure was characterized by light microscopy (LM), scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM). Compression test and tensile test were performed for deformed alloys. The binary Al-5Cu and Al-25Cu alloys consist of the face cantered cubic (FCC) α phase in the form of dendrites and tetragonal (C16) θ-Al2Cu intermetallic phase observed in interdentritic regions. The increase of Cu content leads to increase of interdentritic regions. The microstructure of the alloys is refined after applying KoB deformation with λ = 30 and λ = 98. Ultimate Tensile Strength (UTS) of Al-5Cu alloy after KoBo deformation with λ = 30 and λ = 98 reached about 200 MPa. UTS for samples of Al-25Cu with λ = 30 and λ = 98 increased compared to Al-5Cu alloy and exceed 320 MPa and 270 MPa respectively. All samples showed increase of plasticity with increase of reduction coefficient. Independently of reduction coefficient, the compressive strain of Al-5Cu alloys is about 60%. The Al-25Cu alloy with λ = 98 showed the value of compressive strain exceed 60%, although for this same alloy but with λ = 30, the compressive strain is only 35%.
Mycobacterium chimaera is the newly described species belonging to Mycobacterium avium complex (MAC), with morphology and growth characteristics closely related to Mycobacterium intracellulare . The ...aim of this retrospective study was to analyze the frequency and clinical significance of M. chimaera identification in the population of patients with previous positive respiratory cultures for M. intracellulare or MAC. 200 strains of M. intracellulare or MAC, isolated from respiratory specimens of patients hospitalized in pulmonary wards, between 2011 and 2020, were retrospectively analyzed with GenoType NTM-DR test. 88 (44%) of strains were re-classified to M. chimaera species. Analysis of clinical data in 30 patients with positive M. chimaera isolates revealed that they were diagnosed with chronic obstructive pulmonary disease (COPD) – 27%, past tuberculosis – 20%, or interstitial lung diseases – 17%, respectively. Non-tuberculous mycobacterial lung disease (NTMLD) caused by M. chimaera has been recognized in 53% of patients, most often in those presenting with post-tuberculous lung lesions. M. chimaera was almost exclusively isolated from respiratory specimens of patients with underlying lung diseases, especially those with COPD and/or past tuberculosis. NTMLD due to M. chimaera was diagnosed predominantly in patients with past tuberculosis.
The samples of the CuCr0.6 alloy in the solution treated and additionally in aging states were severely plastically deformed by compression with oscillatory torsion (COT) method to produce ultrafine ...– grained structure. The samples were processed by using process parameters as: frequency of torsion (f = 1.6 Hz), compression speed (v = 0.04 mm/s), angle torsion (α = ±6°), height reduction (Δh = 7 mm). The total effective strain was εft = 40. The microstructure has been analyzed by scanning transmission electron microscope (STEM) Hitachi HD-2300A equipped with a cold field emission gun at an accelerating voltage of 200 kV. The quantitative microstructure investigations as disorientation angles were performed using a FEI INSPECT F scanning electron microscope (SEM) equipped with a cold field emission gun and a electron backscattering diffraction (EBSD) detector. The mechanical properties were determined using MST QTest/10 machine equipped with digital image correlation (DIC). The COT processed alloy previously aged at 500°C per 2h shows high mechanical strength, ultimate tensile strength UTS: 521 MPa and yield tensile strength YS: 488 MP attributed to the high density of coherent precipitates and ultrafine grained structure.
Civilizational progress initially contributes to the problem of hair loss and then to alopecia as regards both frequency and therapeutic dilemmas. The work presents trichological problems which occur ...more rarely, i.e. drug-induced, anagen and telogen alopecia, congenital and acquired structural hair disorders, psychic disturbances concerning the hair as well as the hair during menopause. Then, the article briefly describes contagious (infectious) diseases as well as diseases with inflammatory etiology which are accompanied by exfoliation and (frequently) pruritus. Finally, alopecia cicatricans is discussed. Alopecia areata and androgenetic alopecia are omitted herein because they occur more often and will be described in another work. Any disproportions and upset balance concerning correct functioning of mechanisms within the scalp hair system are the evidence of pathologies.
Microstructure and texture of the CuCr0.6 alloy processed by rolling with cyclic movement of rolls (RCMR) at room temperature were investigated. The RCMR processing was applied for the samples in ...different initial conditions in the solid solution followed by quenching into iced water at 1000oC for 3 h and in aging treatment conditions performed at 500oC for 2 h and at 700oC for 24 h. Application of the solution and aging processes prior to RCMR deformation results in the partial dissolution of Cr particles into the Cu matrix and precipitation of the second phase particles. RCMR processing with value of the total effective strain (εft) of 5 was introduced to the material. It was found that the RCMR method is effective in texture weakening. The obtained results revealed that there is a large similarity in texture orientations after RCMR processing independently of heat treatment conditions. Cyclic character of deformation leads to an incomplete transition of LAB to HAB.
Two strength-age hardening aluminum-lithium alloys: Al-2.3wt%Li and Al-2.2wt%Li-0.1wt%Zr in two different heat treatment conditions: solution state (S) and additionally in aging state (A) were ...severely plastically deformed by rolling with cyclic movement of rolls (RCMR) method to produce ultrafine – grained structure. Two thermo-mechanical treatments were used: (S+A+RCMR) and (S+RCMR+A+RCMR). To investigate the combined effect of plastic deformation and heat treatment, tensile tests were performed. Microstructural observations were undertaken using scanning transmission electron microscopy (STEM), and scanning transmission electron microscopy (SEM) equipped with electron backscattering diffraction detector (EBSD). Based on the obtained results, it can be deduced that maximum mechanical properties as: yield strength (YS) and ultimate tensile strength (UTS) could be achieved when the microstructure of alloys is in (S+A+RCMR) state. For samples in (S+RCMR+A+RCMR) state, ductility is higher than for (S+A+RCMR) state. The microstructural results shows that the favourable conditions for decreasing grain size of alloys is (S+A+RCMR) state. Additionally, in this state is much greater dislocation density than for (S+RCMR+A+RCMR) state. The microstructure of alloys in (S+RCMR+A+RCMR) state is characterized by grains/subgrains with higher average diameter and with higher misorientation angles compared with (S+A+RCMR) state.
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