Various patterns of leukoencephalopathy have been described in coronavirus disease 2019 (COVID-19). In this article, we aimed to describe the clinical and imaging features of acute disseminated ...leukoencephalopathy in critically ill patients with COVID-19 and the imaging evolution during a short-term follow-up.
We identified and reviewed the clinical data, laboratory results, imaging findings, and outcomes for 8 critically ill patients with COVID-19 with acute disseminated leukoencephalopathy.
All patients demonstrated multiple areas of white matter changes in both cerebral hemispheres; 87.5% (7/8) of patients had a posterior predilection. Four patients (50%) had short-term follow-up imaging within a median of 17 days after the first MR imaging; they developed brain atrophy, and their white matter lesions evolved into necrotizing cystic cavitations. All (8/8) patients had inflammatory cytokine release syndrome as demonstrated by elevated interleukin-6, D-dimer, lactate dehydrogenase, erythrocyte sedimentation rate, C-reactive protein, and ferritin levels. Most (7/8; 87.5%) patients were on prolonged ventilator support (median, 44.5 days; interquartile range, 20.5 days). These patients had poor functional outcomes (6/8 75% patients were discharged with mRS 5) and high mortality (2/8, 25%).
Critically ill patients with COVID-19 can develop acute disseminated leukoencephalopathy that evolves into cystic degeneration of white matter lesions with brain atrophy during a short period, which we dubbed virus-associated necrotizing disseminated acute leukoencephalopathy. This may be the result of COVID-19-related endothelial injury, cytokine storm, or thrombotic microangiopathy.
Measuring the thermokinetic data of chemical reactions is an important part for chemical process development. However, some reactions are very sensitive to the presence of metals, limiting the use of ...standard materials for calorimeters. In this work we present a flow calorimeter employing a 3D printed ceramic reactor plate for the measurement of metal-sensitive reactions. The calorimeter was characterized by residence time measurements aided by mixing simulations, and was validated
via
a standard neutralization reaction, an aggressive nitration reaction, and a binary solvent system for mixing enthalpy, before being used for a nitrosylation reaction featuring a metal sensitive product.
A ceramic flow calorimeter for metal-sensitive reactions is characterized and used to obtain thermokinetic data on highly exothermic reactions.
Liquid silicone is an inert material that is utilized for cosmetic procedures by physicians as well as illegally by nonmedical personnel. We present a case report and collated clinical findings of 32 ...other patients who were hospitalized after illegal silicone injections. Symptoms and signs of the "silicone syndrome" included dyspnea, fever, cough, hemoptysis, chest pain, hypoxia, alveolar hemorrhage, and altered consciousness. Bilateral patchy alveolar infiltrates were present on the chest radiographs, and silicone pulmonary emboli were detected in all the patients. The patients could be divided into two groups based on the initial presentation and clinical outcome. Twenty-seven patients in group 1 presented predominantly with respiratory symptoms, and 93% of patients were discharged home within 3 weeks. Six patients (group 2) presented with severe neurologic findings, and experienced rapid deterioration and 100% mortality. The clinical findings after silicone embolism are very similar to the published reports of fat embolism, including hypoxemia in 92% of patients with silicone embolism (patients with fat embolism, 56 to 96%), dyspnea in 88% of patients (patients with fat embolism, 56 to 75%), fever in 70% of patients (patients with fat embolism, 23 to 67%), alveolar hemorrhage in 64% of patients (patients with fat embolism, 66%), neurologic symptoms in 33% of patients (patients with fat embolism, 22 to 86%), petechiae in 18% of patients (patients with fat embolism, 20 to 50%), chest pain in 15% of patients (patients with fat embolism, 26%), and mortality in 24% of patients (patients with fat embolism, 5 to 20%). The similarities among the mode of injury to the lung, the clinical findings, and the high incidence of alveolar hemorrhage suggest a common pathogenesis of silicone and fat embolism syndromes. We discuss the possibility that the activation of the coagulation system may be important in the development of these clinical syndromes.
•Strong retention of perrhenate on new IC column material.•Preconcentration of perrhenate in the presence of other anions.•Zn cyclen resorcinarene preferentially retains perrhenate.•Perrhenate ...separation from environmental sample.
Technetium poses an environmental hazard because of its radioactivity and long half-life. It exists in the form of pertechnetate in the environment and can be modeled by the nonradioactive ion perrhenate, since pertechnetate and perrhenate have the same geometry and similar chemical properties. In this research, a new zinc cyclen resorcinarene cavitand (ZCR) column was used in ion chromatography (IC) to efficiently separate perrhenate. Ion chromatography has the advantage of requiring almost no sample preparation for water samples. The ZCR column demonstrated the ability to separate anions: fluoride, chloride, nitrate, sulfate, phosphate, perchlorate, and perrhenate by gradient 2–60 mM NaOH. Unlike other columns, the new column material was selective in retaining perrhenate. The ZCR column also gave a linear range from 2.0 to 1000 mg L−1 for perrhenate with R2 > 0.997. There was a logarithmic relationship between the concentration of perrhenate and its retention time. Excellent perrhenate recovery was achieved on the ZCR column when river water was spiked with perrhenate and perrhenate was preconcentrated. The efficient separations of perrhenate by the ZCR column will potentially assist in pertechnetate separations.
Placement and use of pulmonary artery catheters (PACs) carry potential risks. The authors describe a case of a patient who developed massive hemoptysis after placement of a PAC that caused a rupture ...of the pulmonary artery with pseudoaneurysm formation. Treatment was successfully achieved with transcatheter coil embolization. Pulmonary artery rupture and pseudoaneurysm formation are among the most serious complications of PAC use because of the associated risk of mortality. Patients with this complication may be asymptomatic or may present with variable amounts of hemoptysis immediately or days after using a PAC. The gold standard diagnostic test is pulmonary angiography, and the treatment of choice for most patients is transcatheter embolization. Physicians and other health care personnel handling these catheters should be familiar with the specific PAC balloon’s inflation limits to avoid complications that may injure the patient.
The binding of apoA-I-containing ligands to the HDL receptor scavenger receptor class B type I (SR-BI) was characterized using two different assays. The first employed conventional binding or ...competition assays with (125)I-labeled ligands. The second is a new nonradioactive ligand binding assay, in which the receptor-associated ligand is detected by quantitative immunoblotting ("immunoreceptor assay"). Using both methods, we observed that the K(d) value for spherical HDL (density = 1.1-1.13 g/ml) was approximately 16 microgram of protein/ml, while the values for discoidal reconstituted HDL (rHDL) containing proapoA-I or plasma apoA-I were substantially lower (approximately 0.4-5 microgram of protein/ml). We also observed reduced affinity and/or competition for spherical (125)I-HDL cell association by higher relative to lower density HDL and very poor competition by lipid-free apoA-I and pre-beta-1 HDL. Deletion of either 58 carboxyl-terminal or 59 amino-terminal residues from apoA-I, relative to full-length control apoA-I, resulted in little or no change in the affinity of corresponding rHDL particles. However, rHDL particles containing a double mutant lacking both terminal domains competed poorly with spherical (125)I-HDL for binding to SR-BI. These findings suggest an important role for apoA-I and its conformation/organization within particles in mediating HDL binding to SR-BI and indicate that the NH(2) and COOH termini of apoA-I directly or indirectly contribute independently to binding to SR-BI.
Background Repeated inhalation of allergen at low‐dose induces an increase in bronchial hyper‐responsiveness, without any associated symptom. The concomitant events in the bronchus have not been ...described.
Objective We have studied the dynamic number of mast cells in the airways of patients with mild asthma before and after repeated inhalation of allergen at low‐dose and the expression of nerve growth factor (NGF), which is reported to promote growth and survival of mast cells.
Methods Twelve patients with mild asthma to cat allergen were enrolled at random in a blind placebo‐controlled study, and submitted to repeated low‐dose allergen exposure (1/5 of the provocative dose). Mast cells were immunolocalized using an antibody against mast cell tryptase. NGF and its high affinity receptor, TrkA, were immunolocalized using anti‐NGF and anti‐TrkA antibodies, respectively. NGF mRNA was quantified by competitive polymerase chain reaction (PCR) after reverse transcription of total RNA extracted from bronchial biopsy. NGF protein levels were measured by ELISA in bronchoalveolar lavage (BAL) fluid.
Results Bronchial mast cell number was increased significantly after allergen exposure as compared with before. NGF expression in the bronchus was immunolocalized mainly to epithelial cells, but also to fibroblasts, blood vessels, and a few infiltrated cells. NGF mRNA levels in bronchial biopsies were increased significantly after allergen exposure. The high affinity receptor for NGF, TrkA, was immunolocalized to the infiltrated mast cell membrane.
Conclusion Our study shows that the increase in the number of mast cells and in the expression of NGF induced by allergen exposure in the bronchus of asthmatic patients is occurring before the onset of symptoms. In addition, our finding of the presence of the TrkA receptor on the membrane of the infiltrated mast cell in situ brings evidence of the mast cell as a target cell for the growth factor activity of NGF in the airways in asthma.
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