Mast cell activation markers for in vitro study

ABSTRACT

Mast cells (MCs) are well known for their role in allergic conditions. This cell can be activated by various types of secretagogues, ranging from a small chemical to a huge protein. Mast cell activation by secretagogues triggers the increase in intracellular calcium (iCa²⁺) concentration, granule trafficking, and exocytosis. Activated mast cells release their intra-granular pre-stored mediator or the newly synthesized mediator in the exocytosis process, in the form of degranulation or secretion. There are at least three types of exocytosis in mast cells, which are suggested to contribute to the release of different mediators, i.e.,, piecemeal, kiss-and-run, and compound exocytosis. The status of mast cells, i.e., activated or resting, is often determined by measuring the concentration of the released mediator such as histamine or β-hexosaminidase. This review summarizes several mast cell components that have been and are generally used as mast cell activation indicator, from the classical histamine and β-hexosaminidase measurement, to eicosanoid and granule trafficking observation. Basic principle of the component determination is also explained with their specified research application and purpose. The information will help to predict the experiment results with a certain study design.     

Combined effect of Controlling Nutritional Status and Acute Kidney Injury on severe COVID-19 short-term outcomes

Introduction/ObjectivesAcute kidney injury (AKI) and malnutrition are two complications commonly reported in severe forms of COVID-19, their combined effect on short-term mortality is, however, not yet investigated. The objective of this study is to determine both their individual and combined effects on short-term prognosis.Materials and methodsThis is a prospective, uni-centric study, including 247 severe COVID-19 patients, admitted between April 25th and June 20th, 2020, at the University Hospital of Blida. AKI was defined according to the KDIGO-2012 guidelines. Nutritional status was assessed using the Controlling Nutritional Status (CONUT) score. The association with in-hospital mortality was assessed using the Kaplan-Meier method and proportional Cox regression.ResultsAmong the 247 severely affected COVID-19 patients included in this study, 34.4% developed AKI, 30.4 and 1.2%, respectively, had moderate and severe CONUT scores, 17.7% worsened and progressed to a critical state and 26.7% did not survive. Both AKI and CONUT score were significantly associated with mortality in a dose-response manner (pLog-Rank < 0.0001). Their relative risks are respectively (HR = 3.25 CI 95% [1.99–5.3] and HR = 2.42 CI 95% [1.5–3.9], p < 0.0001). In multivariate analysis, the highest risk was observed for the AKI-CONUT-high combination (HR = 3.0, 95% CI [1.5–6.1], p = 0.002).ConclusionA possible synergistic interaction between AKI and CONUT score for COVID-19 short-term mortality has been highlighted. Monitoring of renal function associated with assessment of nutritional status should be performed routinely and systematically from the early stages of admission.     

Diffuse glomerular basement membrane lamellation in renal allografts from pediatric donors to adult recipients

The transplantation of kidneys from pediatric cadaveric donors into adult recipients is performed in many centers. However, some studies indicate that the outcome of such renal transplants may be inferior compared with that of adult donors, particularly if the donor is an infant. Morphologic studies of failed pediatric donor kidneys in adult recipients describe various degrees of segmental or global glomerular sclerosis. The authors have performed ultrastructural examinations on such transplants and have identified six cases with diffuse irregular lamellation of the glomerular basement membrane (GBM), a change that may develop as early as 10 weeks after transplantation. The age of all donors was < or =6 years; three were infants. The incidence of the lesion was 9% at our institution in renal transplant patients who received a graft from donors <10 years old. Diffuse GBM lamellation has not been found in renal transplants from adult donors. Light microscopy showed various degrees of diffuse mesangial expansion, usually with segmental glomerular sclerosis. The patients had severe proteinuria. While recurrent focal segmental glomerular sclerosis (FSGS) has to be excluded, such diffuse GBM lamellation is generally not seen in recurrent FSGS cases. The pathogenesis of the lesion is most likely related to hyperperfusion injury of small pediatric donor kidneys grafted into adult recipients.     

Isolation and Characterization of a Phapecoctavirus Infecting Multidrug-Resistant Acinetobacter baumannii in A549 Alveolar Epithelial Cells

Multidrug-resistant Acinetobacter baumannii (MDR A. baumannii) is an emerging pathogen in the ESKAPE group. The global burden of antimicrobial resistance has led to renewed interest in alternative antimicrobial treatment strategies, including phage therapy. This study isolated and characterized a phage vB_AbaM_ ABPW7 (vABPW7) specific to MDR A. baumannii. Morphological analysis showed that phage vABPW7 belongs to the Myoviridae family. Genome analysis showed that the phage DNA genome consists of 148,647 bp and that the phage is a member of the Phapecoctavirus genus of the order Caudovirales. A short latent period and a large burst size indicated that phage vABPW7 was a lytic phage that could potentially be used in phage therapy. Phage vABPW7 is a high-stability phage that has high lytic activity. Phage vABPW7 could effectively reduce biofilm formation and remove preformed biofilm. The utility of phage vABPW7 was investigated in a human A549 alveolar epithelial cell culture model. Phage vABPW7 was not cytotoxic to A549 cells, and the phage could significantly reduce planktonic MDR A. baumannii and MDR A. baumannii adhesion on A549 cells without cytotoxicity. This study suggests that phage vABPW7 has the potential to be developed further as a new antimicrobial agent against MDR A. baumannii.     

Isolated temporal infarct due traumatic vertebral artery dissecting pseudo-aneurysm: a rare case report

The authors describe a rare case of traumatic vertebral artery dissecting pseudo-aneurysm with temporal lobe infarct in the pre-foramina segment of the left vertebral artery following knife injury of the left anterolateral neck area. A 40 years old man was admitted to the emergency department after a penetrating injury in the left anterolateral neck. On contrast-enhanced CT and Doppler ultrasonography in the neck, a dissecting pseudo-aneurysm of the vertebral artery was revealed.On day 2, MRI scanning revealed an ischemic infarct in the temporal lobe, which can be attributed to vertebral artery injury. The case was treated conservatively and the patient was discharged on the fourth hospital day. Owing to the position of the artery, traumatic vertebral artery dissections are uncommon, and they are linked with a high mortality rate due to aneurismal rupture and embolic impact of the dissections, culminating in stroke in young people. Our findings demonstrate the necessity of imaging in head and neck traumatic injuries to detect vertebral artery injuries far sooner in order to prevent complications.     

Strain and magnetic field effects on the electronic and transport properties of γ-graphyne

In this paper, we apply a tightly binding Hamiltonian model in the presence of a magnetic field for investigating the electronic and transport properties of γ-graphyne layers. We also consider the effects of in-plane biaxial strain on the electronic behavior of γ-graphyne layers. Moreover the impact of strain on magnetic susceptibility and specific heat of the structure is also studied. In particular, the temperature dependence of static thermal conductivity of γ-graphyne layers due to magnetic field and strain effects is studied. We exploit the linear response theory and Green''s function approach to obtain the temperature behavior of thermal conductivity, electrical conductivity and the Seebeck coefficient. Our numerical results indicate that thermal conductivity increases upon increasing temperature temperatures. This effect comes from the increasing thermal energy of charge carriers and their excitation to the conduction bands. The temperature dependence of Seebeck coefficient shows that the thermopower of an undoped γ-graphyne layer is positive on the whole range of temperatures in the absence of strain effects. The effects of both electron doping and magnetic field factors on temperature behavior of the electrical conductivity of γ-graphyne are investigated in detail. Moreover the effects of biaxial strain on thermal conductivity of single layer γ-graphyne have been addressed.

In this paper, we apply a tightly binding Hamiltonian model in the presence of a magnetic field to investigate the electronic and transport properties of γ-graphyne layers.     

Fungal Species and Multi-Mycotoxin Associated with Post-Harvest Sorghum (Sorghum bicolor (L.) Moench) Grain in Eastern Ethiopia

Sorghum is the main staple food crop in developing countries, including Ethiopia. However, sorghum grain quantity and quality are affected by contaminating fungi both under field and post-harvest stage. The aim of the current study was to assessed fungal species and multi-mycotoxins associated with sorghum grain in post-harvest samples collected from eastern Ethiopia. Fungal genera of Aspergillus, Alternaria, Bipolaris, Fusarium, Mucor, Penicillium, and Rhizoctonia were recovered in the infected grain. A liquid chromatography-tandem mass spectrometric (LC-MS/MS) was used for quantification of multiple mycotoxins/fungal metabolites. Overall, 94 metabolites were detected and grouped into eight categories. All metabolites were detected either in one or more samples. Among major mycotoxins and derivatives, deoxynivalenol (137 μg/kg), zearalenone (121 μg/kg), ochratoxin A (115 μg/kg), and fumonisin B₁ (112 μg/kg) were detected with maximum concentrations, while aflatoxin B₁ had relatively lower concentrations (23.6 μg/kg). Different emerging mycotoxins were also detected, with tenuazonic acid (1515 μg/kg) occurring at the maximum concentration among Alternaria metabolites. Fusaric acid (2786 μg/kg) from Fusarium metabolites and kojic acid (4584 μg/kg) were detected with the maximum concentration among Fusarium and Aspergillus metabolites, respectively. Unspecific metabolites were recognized with neoechinulin A (1996 μg/kg) at the maximum concentration, followed by cyclo (L-Pro-L-Tyr) (574 μg/kg) and cyclo (L-Pro-L-Val) (410 μg/kg). Moreover, metabolites form other fungal genera and bacterial metabolites were also detected at varying levels. Apparently, the study revealed that sorghum grains collected across those districts were significantly contaminated with co-occurrences of several mycotoxins. Farmers should be the main target groups to be trained on the improved management of sorghum production.     

广西壮族人HLA-DQB1等位基因与β地中海贫血的相关性

目的：探讨ＨＬＡ抗原与β地中海贫血（地贫）的相关性。方法：应用聚合酶链反应序列特异引物（ＰＣＲＳＳＰ）方法对６４名随机抽样的，无血缘关系，三代以上均为壮族并三代以上居住在广西，籍贯分布广西各地，均在本实验室经基因诊断证实为β地贫的患者进行ＨＬＡＤＱＢ１基因分型。结果：发现ＨＬＡＤＱＢ１０６０４等位基因在该群体中频率为１２．５％，对照组为１．４％；其相对危险度为９．９，与对照组比较，有非常显著差异（显著性检验χ２＝２０．７８，Ｐ＜０．００５）。结论：提示ＨＬＡＤＱＢ１０６０４等位基因与广西壮族居民β地贫的易感性有关联