Superior vena cava thrombosis in chronic lead exposure--a case report

Thrombosis is a rare cause of superior vena cava syndrome (SVCS). A 43-year-old male patient with SVCS due to thrombosis underwent investigation for the etiology of thrombus formation. He had been hospitalized several times because of lead intoxication in the past. Lead has a known thrombogenetic effect experimentally. This patient with superior vena cava thrombosis had thrombophilia that was probably due to lead intoxication. The etiologies of venous thrombosis and thrombogenetic effect of chronic lead exposure are discussed.     

The effect of fluoxetine on ischemia–reperfusion after aortic surgery in a rat model

Background

Aortic ischemia–reperfusion (IR) is an important factor in the development of postoperative acute lung injury after abdominal aortic surgery. The aim of the present study was to examine the effect of fluoxetine (Flx), a selective serotonin reuptake inhibitor widely used as a preoperative anxiolytic, on lung injury induced by abdominal aortic IR in rats.

Methods

Wistar rats were randomized into three groups (n = 7 per group): (1) control (sham laparotomy); (2) IR without Flx (60-min ischemia and 120-min reperfusion); (3) IR with Flx (Flx + IR) (Flx 20 mg/kg/d, intraperitoneally for 3 d before surgery). Lung tissue samples and bronchoalveolar lavage (BAL) were obtained for biochemical analysis of oxidative status. Ischemia-modified albumin (IMA) level and protein concentrations in BAL and lung wet to dry weight ratios were determined. Histologic evaluation of the lung tissues was also performed.

Results

IR without Flx led to significant increase in lipid hydroperoxide, malondialdehyde, and pro-oxidant–antioxidant balance and decrease in superoxide dismutase, glutathione, and ferric reducing antioxidant power activities (P < 0.05 versus control), whereas Flx was able to restore these parameters (P > 0.05 versus control) and decrease IMA level (P < 0.01 versus control) and protein concentration (P < 0.05 versus control) in BAL and wet to dry lung weight ratio. Histologic evaluation showed that Flx attenuated the morphologic changes associated with lung injury.

Conclusions

The results indicate that Flx confers protection against aortic IR-induced lung oxidative stress and cellular integrity. IMA levels in BAL may be used as a follow-up marker for the efficacy of treatment in lung injury.     

Global structural changes of an ion channel during its gating are followed by ion mobility mass spectrometry

Mechanosensitive ion channels are sensors probing membrane tension in all species; despite their importance and vital role in many cell functions, their gating mechanism remains to be elucidated. Here, we determined the conditions for releasing intact mechanosensitive channel of large conductance (MscL) proteins from their detergents in the gas phase using native ion mobility–mass spectrometry (IM-MS). By using IM-MS, we could detect the native mass of MscL from Escherichia coli, determine various global structural changes during its gating by measuring the rotationally averaged collision cross-sections, and show that it can function in the absence of a lipid bilayer. We could detect global conformational changes during MscL gating as small as 3%. Our findings will allow studying native structure of many other membrane proteins.One of the best candidates to explore the gating of mechanosensitive channels is the mechanosensitive channel of large conductance (MscL) from Escherichia coli. The crystal structure of MscL in its closed/nearly closed state from Mycobacterium tuberculosis revealed this channel as a homopentamer (1). Each subunit has a cytoplasmic N- and C-terminal domain as well as two α-helical transmembrane (TM) domains, TM1 and TM2, which are connected by a periplasmic loop. The five TM1 helices form the pore and the more peripheral TM2 helices interact with the lipid bilayer.MscL detects changes in membrane tension invoked by a hypoosmotic shock and couples the tension sensing directly to large conformational changes (1, 2). On the basis of a large body of structural and theoretical data, numerous gating models of MscL have been proposed (3–9). These models agree upon (i) the hydrophobic pore constriction of the channel and (ii) the channel opens by an iris-like rotation—i.e., a tilting and outward movement of transmembrane helices that make the channel wider and shorter (5). This mechanism is supported by patch-clamp (10), disulfide cross-linking (11), FRET spectroscopy (12), and site-directed spin labeling EPR experiments (6, 7), as well as computational studies (13–15). So far, direct experimental results have only been observed for short-range local structural changes, and no measure of the overall global structural changes during channel gating have been reported. Because there is no crystal structure available for the open MscL channel, elucidating overall global structural changes from the onset of channel activation is of utmost importance for our understanding of the gating mechanism of mechanosensitive channels. Here, we provide direct experimental evidence for the key areal changes occurring during channel gating by combining our ability to activate MscL in a controlled manner to different subopen states (16) with a native ion mobility-mass spectrometry (IM-MS) approach.     

The bite force and craniofacial morphology in patients with acromegaly: A pilot study

Objectives: Acromegaly is a metabolic disorder caused by increased growth hormone secretion. As a consequence of acromegaly some typical craniofacial morphology changes appear. This pilot study was conducted to compare the bite force and the characteristic size and shape of the craniofacial components of acromegalic patients with the healthy Turkish individuals. In additon, the correlations between bite force and craniofacial morphology of patients with acromegaly and control individuals were evaluated. Study Design: The maximum bite force of the participants was recorded with strain-gage transducer. Lateral x-ray scans were made under standard conditions, in centric occlusion. On cephalograms, the linear and angular measurements was performed. Results: Patients with acromegaly showed increased anterior and posterior total face height, ramus length, width of frontal sinuse, gonial angle and a negative difference between maxillary and mandibular protrusions. In addition, females with acromegaly showed larger lower anterior face height and sella turcica, decreased facial angle, increased mandibular plane angle. The cephalometric measurements, except one did not showed correlation with the bite force in acromegalic patients. In control group, significant correlations were observed between anterior total face height and anterior lower face height, mandibular plane angle and gonial angle. Conclusions: The greater changes were observed in the mandible. The maximum bite force of patients with acromegaly showed no difference from healthy individuals. The non-significant difference of bite force between healthy participants and acromegalic patients provide important information for dental treatment and prosthetic rehabilitation of acromegalic patients. Key words:Acromegaly, bite force, cephalometric analysis, mandibular prognathism.     

Circulating adhesion molecules in sera of asthmatic children before and after steroid therapy.

The aim of this study was to evaluate respiratory function tests, total eosinophil counts, serum immune globulin E (IgE), and serum concentrations of soluble intercellular adhesion molecule (sICAM)1, soluble vascular cell adhesion molecule (sVCAM) 1, and soluble P-selectin (sP-selectin) levels in the children with mild and/or moderate asthma before and 3 months after inhaled steroids and to determine whether adhesion molecule levels showed any difference between asthmatic and healthy children and whether these levels changed with disease activity. A total of 28 children with bronchial asthma and 24 children as a control group were included in the study. All of the patients in the study group were administered inhaled budesonide treatment. The patients were reevaluated 3 months later. Respiratory functions tests were performed and total eosinophil count and serum total IgE level were determined. Serum levels of sICAM-1, sVCAM-1, and sP-selectin were determined and skin-prick tests were performed. Significant difference paralleled to clinical improvement was found in the study group for respiratory function tests, total eosinophil count, serum IgE level, and sICAM-1 levels determined before and after the treatment. However, no significant difference was found for sP-selectin and sVCAM-1 levels before and after the treatment. The higher level of sICAM-1 before the treatment suggests that leukocyte-endothelial adhesion have a role in bronchial asthma, which is an inflammatory airway disease. Reduction in the level of sICAM-1 after the treatment may be related to the decreased inflammation in response to therapy. However, no strong relationships were found between the determinants representing the inflammation and respiratory function tests.     

Evaluation of Aortic Elasticity Parameters in Survivors of COVID-19 Using Echocardiography Imaging

ObjectiveWhile severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) primarily affects lung tissue, it may cause direct or indirect damage to the cardiovascular system, and permanent damage may occur. Arterial stiffness is an early indicator of cardiovascular disease risk. The aim of our study was to establish the potential effects of SARS-CoV-2 on the vascular system evaluated by transthoracic echocardiographic examination.Subjects and MethodsThis study compared arterial stiffness between the survivors of COVID-19 and those without a history of COVID-19 infection. The difference in aortic diameter was examined using echocardiography.ResultsThe study included 50 patients who survived COVID-19 in the last 3–6 months and 50 age- and gender-matched healthy volunteers. In surviving COVID-19 patients, aortic diastolic diameter in cm ([3.1 ± 0.2] vs. [2.9 ± 0.1], p < 0.001), pulse pressure (PP) ([43.02 ± 14.05] vs. [35.74 ± 9.86], p = 0.004), aortic distensibility ([5.61 ± 3.57] vs. [8.31 ± 3.82], p < 0.001), aortic strain ([10.56 ± 4.91] vs. [13.88 ± 5.86], p = 0.003), PP/stroke volume index ([1.25 ± 0.47] vs. [0.98 ± 0.28], p = 0.001), and aortic stiffness index ([2.82 ± 0.47] vs. [2.46 ± 0.45], p < 0.001) were statistically significant compared to the control group.ConclusionSARS-CoV-2 may cause reduced or impaired aortic elasticity parameters linked to impaired arterial wall function in COVID-19 survivors compared with controls.     

The effect of glutamine supplementation on hematopoietic stem cell transplant outcome in children: A case–control study

Abstract:  HSCT associated morbidity and mortality is usually attributed to high-dose chemotherapy/radiotherapy regimens used for conditioning. Glutamine (Gln), a conditionally essential amino acid during severe catabolic states, has been shown to have favorable effects in patients with malignancies and in those undergoing HSCT. However, controversy exists regarding its routine use. Studies in children investigating gln supplementation are very limited. In the present study, including 21 gln-supplemented and 20 control pediatric patients, gln supplementation was shown to reduce the duration of fever and decrease the incidence of SOS during the HSCT course. In addition, a decrease in drug-related toxicity and a trend toward reduced incidence of severe mucositis were observed.