[Research on the method of loading exosomes onto absorbable stents].

Objective: To explore a method of loading exosomes onto absorbable stents. Methods: By building a stent-(3-aminopropyl) triethoxysilane-1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol) 5000]-exosomes connection, the exosomes were loaded onto absorbable stents to obtained the exosome-eluting absorbable stents. The surface conditions of the stents and absorption of exosomes were observed by scanning electron microscope and identified through the time-of-flight mass spectrometry; the roughness of the stents' surfaces was observed by atomic force microscope; the appearances and sizes of the stents were observed by stereomicroscope; and the radial force was tested by tensile test machine. The absorbable stents were used as control. Results: The scanning electron microscope observation showed that the exosome-eluting absorbable stents had some small irregular cracks on the surface where many exosomes could be seen. The atomic force microscopy observation showed that within the range of 5 µm 2, the surface roughness of the absorbable stents was ±20 nm, while the surface roughness of the exosome-eluting absorbable stents was ±70 nm. In the results of time-of-flight mass spectrometry, both the exosome-eluting absorbable stents and exosomes had a peak at the mass charge ratio of 81 (m/z 81), while the absorbable stents did not have this peak. The peak of exosome-eluting absorbable stents at m/z 73 showed a significant decrease compared to the absorbable stents. The stereomicroscope observation showed that the sizes of exosome-eluting absorbable stents met standards and the surfaces had no cracks, burrs, or depressions. The radial force results of the exosome-eluting absorbable stents met the strength standards of the original absorbable stent. Conclusion: By applying the chemical connection method, the exosomes successfully loaded onto the absorbable stents. And the sizes and radial forces of this exosome-eluting absorbable stents meet the standards of the original absorbable stents.

Long-Term Efficacy Analysis of Surgical Resection of 70 Primary Right Heart Tumors.

INTRODUCTION: The aim of the study was to investigate the clinical characteristics, surgical treatment, and long-term efficacy of primary right heart tumors. METHODS: This study is retrospective analysis of the clinical data of 70 patients with primary right heart tumors admitted to our department between 1980 and 2022 (observation group) and 70 patients with left heart tumors during the same period (control group). The surgical treatment was performed under cardiopulmonary bypass after differential diagnosis by echocardiography, cardiac CTA, and PET-CT before the surgery. The perioperative characteristics, recurrence rate, and long-term survival rates of right heart tumor versus left heart tumor were compared. RESULTS: The most common pathological types of right heart tumors were myxoma (60%), lipoma (8.57%), and papillary elastofibroma (7.14%). During the perioperative period, there were 1 case of systemic embolism in the observation group, compared with 6 in the control group (p = 0.026), 13 cases of malignant tumor in the observation group versus 1 in the control group (p = 0.01). During the follow-up period, there were 15 cases of tumor recurrence and 17 cases of death in the observation group versus 4 (p = 0.002) and 7 in the control group (p = 0.006), comparatively. CONCLUSION: Compared with left heart tumors, primary right heart tumors had a higher incidence of malignant tumors and a lower risk of systemic embolism during perioperative period. During the follow-up period, primary right heart tumors had a higher rate of tumor recurrence and a lower long-term survival rate.

Myricetin exerts anti-biofilm activity and attenuates osteomyelitis by inhibiting the TLR2/MAPK pathway in experimental mice.

AIMS: To evaluate the potential of Myricetin against S.aureus induced osteomyelitis. BACKGROUND: Osteomyelitis is infected condition of bone by micro-organisms. The mitogen-activated protein kinase (MAPK), inflammatory cytokines and Toll-like receptor-2 (TLR-2) pathway are mainly involved in osteomyelitis. Myricetin is a plant-food derived flavonoid which shows anti-inflammatory activity. OBJECTIVE: In the present study, we evaluated the potential of Myricetin against S.aureus induced osteomyelitis. MC3T3-E1 cells were used for in vitro studies. METHOD: Murine model of osteomyelitis was developed in BALB/c mice by injecting S.aureus in the medullary cavity of the femur. The mice were studied for bone destruction, anti-biofilm activity, osteoblast growth markers alkaline phosphatase (ALP), osteopontin (OCN) and collagen type-I (COLL-1) were studied by RT-PCR, ELISA analysis for levels of proinflammatory factors CRP, IL-6 and IL-1ß. Expression of proteins by Western blot analysis and anti-biofilm effect by Sytox green dye fluorescence assay. Target confirmation was done by performing in silico docking analysis. RESULTS: Myricetin reduced bone destruction in osteomyelitis induced mice. The treatment decreased bone levels of ALP, OCN, COLL-1 and TLR2. Myricetin decreased serum levels of CRP, IL-6 and IL-1ß. The treatment suppressed activation of MAPK pathway and showed anti-biofilm effect. Docking studies suggested high binding affinity of Myricetin with MAPK protein in silico, by showing lower binding energies. CONCLUSION: Myricetin suppresses osteomyelitis by inhibiting ALP, OCN, COLL-1 via the TLR2 and MAPK pathway involving inhibition of biofilm formation. In silico studies suggested MAPK as potential binding protein for myricetin.

Acute Type A Aortic Dissection and Late Pregnancy: What Should We Do?

ABSTRACT Introduction: Acute type A aortic dissection (AAAD) in late pregnancy is a rare but severe disease. Lack of clinical experience is the main cause of high mortality. This study tries to investigate the multidisciplinary therapeutic strategy for these patients. Case presentation: We reported three patients with AAAD in late pregnancy. Sudden chest pain was the main clinical symptom before operation. All three patients and their newborns survived through multidisciplinary approach in diagnosis and treatment. No serious complications occurred during the mid-term follow-up. Conclusion: Multidisciplinary diagnosis and treatment strategy play a crucial role in saving the lives of pregnant women with AAAD.

Acute Type A Aortic Dissection and Late Pregnancy: What Should We Do?

INTRODUCTION: Acute type A aortic dissection (AAAD) in late pregnancy is a rare but severe disease. Lack of clinical experience is the main cause of high mortality. This study tries to investigate the multidisciplinary therapeutic strategy for these patients. CASE PRESENTATION: We reported three patients with AAAD in late pregnancy. Sudden chest pain was the main clinical symptom before operation. All three patients and their newborns survived through multidisciplinary approach in diagnosis and treatment. No serious complications occurred during the mid-term follow-up. CONCLUSION: Multidisciplinary diagnosis and treatment strategy play a crucial role in saving the lives of pregnant women with AAAD.

Combination of kaempferol and azithromycin attenuates Staphylococcus aureus-induced osteomyelitis via anti-biofilm effects and by inhibiting the phosphorylation of ERK1/2 and SAPK.

Osteomyelitis is bacterial infection of bone, commonly caused by Staphylococcus aureus. This work aims to study the potential of azithromycin and kaempferol against chronic osteomyelitis induced by azithromycin-resistant Staphylococcus aureus (ARSA). It was noticed that rats tolerated the treatments with no diarrhoea or weight loss; also, no deaths were observed in rats. The treatment by azithromycin alone failed to inhibit bacterial growth and also had no effect on the infection condition of bone, although the treatment decreased the levels of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α), but did not improve the oxidative stress levels. Kaempferol monotherapy slightly inhibited bacterial growth and bone infection; the treatment also inhibited the levels of IL-6 and (TNF-α). The treatment also improved the antioxidant status. However, the combined treatment of azithromycin and kaempferol significantly suppressed bacterial growth and bone infection and modulated oxidative stress. In vitro, the combined treatment inhibited the levels of IL-6 and TNF-α, and also suppressed the phosphorylation of ERK1/2 and stress-activated protein kinase (SAPK). The combined treatment also showed anti-biofilm activity in ARSA. The combination attenuates ARSA-induced osteomyelitis in rats compared with their treatments alone by reducing oxidative stress, inhibiting the phosphorylation of ERK1/2 and SAPK and inhibiting biofilm formation.

Nanoscale Au@SiO2-drug/VEGF as an in vivo probe for osteosarcoma diagnosis and therapy.

Osteosarcoma is a common primary bone malignancy, with a 5-year survival rate of only 20-30% in patients undergoing surgical treatment. Thus, it is important to identify novel methods for diagnosing and treating osteosarcoma, which was the aim of the present study. Vascular endothelial growth factor (VEGF) was used as the tumor-targeting protein to synthesize a multifunctional core-shell nanostructure, Au@SiO2-drug/VEGF, in which the drug can be indocyanine green (ICG; as an optical tracer) or doxorubicin (DOX; as a chemotherapeutic agent). With VEGF as the osteosarcoma-targeting protein, Au exhibited optimal photothermal transformation performance, while SiO2 served as the carrier for the drug. Au@SiO2-ICG/VEGF nanoparticles (NPs) were evaluated for imaging and for the monitoring of drug accumulation in a tumor region in mice. Once the optimal drug accumulation was achieved, combined treatment of osteosarcoma (chemotherapy and photothermal therapy) was assessed. In the perioperative period associated with minimal invasive embolization of osteosarcoma, photothermal therapy and chemotherapy were applied for osteosarcoma diagnosis using Au@SiO2-DOX/VEGF NPs. Taken together, the results of the present study provide a promising strategy for tumor detection prior to surgical treatment to improve the survival outcome of patients with osteosarcoma.

A Non-covalent Ligand Reveals Biased Agonism of the TRPA1 Ion Channel.

The TRPA1 ion channel is activated by electrophilic compounds through the covalent modification of intracellular cysteine residues. How non-covalent agonists activate the channel and whether covalent and non-covalent agonists elicit the same physiological responses are not understood. Here, we report the discovery of a non-covalent agonist, GNE551, and determine a cryo-EM structure of the TRPA1-GNE551 complex, revealing a distinct binding pocket and ligand-interaction mechanism. Unlike the covalent agonist allyl isothiocyanate, which elicits channel desensitization, tachyphylaxis, and transient pain, GNE551 activates TRPA1 into a distinct conducting state without desensitization and induces persistent pain. Furthermore, GNE551-evoked pain is relatively insensitive to antagonist treatment. Thus, we demonstrate the biased agonism of TRPA1, a finding that has important implications for the discovery of effective drugs tailored to different disease etiologies.

Styrene Hydroformylation with In Situ Hydrogen: Regioselectivity Control by Coupling with the Low-Temperature Water-Gas Shift Reaction.

The hydroformylation of olefins is one of the most important homogeneously catalyzed industrial reactions for aldehyde synthesis. Various ligands can be used to obtain the desired linear aldehydes in the hydroformylation of aliphatic olefins. However, in the hydroformylation of aromatic substrates, branched aldehydes are formed preferentially with common ligands. In this study, a novel approach to selectively obtain linear aldehydes in the hydroformylation of styrene and its derivatives was developed by coupling with a water-gas shift reaction on a Rh single-atom catalyst without the use of ligands. Detailed studies revealed that the hydrogen generated in situ from the water-gas shift is critical for the highly regioselective formation of linear products. The coupling of a traditional homogeneous catalytic process with a heterogeneous catalytic reaction to tune product selectivity may provide a new avenue for the heterogenization of homogenous catalytic processes.

Development of Photocrosslinking Probes Based on Huwentoxin-IV to Map the Site of Interaction on Nav1.7.

Voltage-gated sodium (Nav) channels respond to changes in the membrane potential of excitable cells through the concerted action of four voltage-sensor domains (VSDs). Subtype Nav1.7 plays an important role in the propagation of signals in pain-sensing neurons and is a target for the clinical development of novel analgesics. Certain inhibitory cystine knot (ICK) peptides produced by venomous animals potently modulate Nav1.7; however, the molecular mechanisms underlying their selective binding and activity remain elusive. This study reports on the design of a library of photoprobes based on the potent spider toxin Huwentoxin-IV and the determination of the toxin binding interface on VSD2 of Nav1.7 through a photocrosslinking and tandem mass spectrometry approach. Our Huwentoxin-IV probes selectively crosslink to extracellular loop S1-S2 and helix S3 of VSD2 in a chimeric channel system. Our results provide a strategy that will enable mapping of sites of interaction of other ICK peptides on Nav channels.

p53 mediates PEDF­induced autophagy in human umbilical vein endothelial cells through sestrin2 signaling.

Autophagy is a conserved catabolic process by which cytoplasmic components are delivered into lysosomes for degradation. Pigment epithelium­derived factor (PEDF) has been reported to be associated with autophagy and can induce p53 expression; however, the mechanism relating PEDF with autophagy in endothelial cells remains poorly understood. The present study aimed to investigate the association between the PEDF­p53­sestrin pathway and autophagy in human umbilical vein endothelial cells (HUVECs). PEDF­induced autophagy was examined by fluorescence microscopy and western blot analysis. p53 small interfering (si)RNA and sestrin2 siRNA were constructed and transfected into HUVECs prior to PEDF treatment. The protein expression levels of microtubule­associated protein light chain 3 (LC3) I, LC3 II and p62 were evaluated by western blot analysis, and the mRNA expression levels of p53 and sestrin2 were determined using reverse transcription­quantitative polymerase chain reaction analysis. The regulation of mechanistic target of rapamycin (mTOR) was reflected by p70S6 kinase (p70S6K) and eukaryotic translation initiation factor 4E­binding protein 1 (4E­BP1) protein expression levels, as determined by western blot analysis. PEDF could induce HUVEC autophagy by sequentially inducing p53 and sestrin2 expression, as observed by fluorescence microscopy and western blot analysis. Conversely, the induction of sestrin2 by PEDF was eliminated by p53 siRNA. In addition, p53 siRNA and sestrin2 siRNA could attenuate PEDF­induced HUVEC autophagy. Inhibition of mTOR may be the mechanism responsible for PEDF­induced autophagy; as p70S6K and 4E­BP1 phosphorylation levels were significantly upregulated in p53 siRNA­treated and sestrin2 siRNA­treated groups. The findings of the present study indicated that PEDF may trigger autophagy in HUVECs by inducing p53 and sestrin2 expression, and inhibiting mTOR expression; these findings may contribute to the improved understanding of diseases, including cancer and atherosclerosis.

Structural Basis of Nav1.7 Inhibition by a Gating-Modifier Spider Toxin.

Voltage-gated sodium (Nav) channels are targets of disease mutations, toxins, and therapeutic drugs. Despite recent advances, the structural basis of voltage sensing, electromechanical coupling, and toxin modulation remains ill-defined. Protoxin-II (ProTx2) from the Peruvian green velvet tarantula is an inhibitor cystine-knot peptide and selective antagonist of the human Nav1.7 channel. Here, we visualize ProTx2 in complex with voltage-sensor domain II (VSD2) from Nav1.7 using X-ray crystallography and cryoelectron microscopy. Membrane partitioning orients ProTx2 for unfettered access to VSD2, where ProTx2 interrogates distinct features of the Nav1.7 receptor site. ProTx2 positions two basic residues into the extracellular vestibule to antagonize S4 gating-charge movement through an electrostatic mechanism. ProTx2 has trapped activated and deactivated states of VSD2, revealing a remarkable ∼10 Å translation of the S4 helix, providing a structural framework for activation gating in voltage-gated ion channels. Finally, our results deliver key templates to design selective Nav channel antagonists.

Retrospective analysis of 11 cases of primary cardiac valve tumors.

OBJECTIVE: To explore the clinical features and surgical treatment experience of primary cardiac valve tumor. METHODS: The present study retrospectively analyzed the clinical data of 11 patients with primary valvular tumors who underwent surgical treatment in our department from 1980 to 2016. Echocardiography of preoperative patients was indicated as a heart valve tumor. All patients underwent cardiopulmonary bypass surgery after endocardial angiography and positron emission tomography-computed tomography diagnosis, including four tumor resections-valvuloplasty and seven tumor resections-heart valve replacement. Pathological analysis was performed on all tumors. Postoperative cardiac ultrasound was followed up. Pathological analysis was performed on all tumors. All patients underwent postoperative ultrasound follow-up examination. RESULTS: Primary valvular tumors are rare, accounting for only 0.034% (11/32.728) of extracorporeal circulation surgery in our center. It accounts for 2.8% (11/399) of primary cardiac tumors in the same period. Pathological study indicated that there were 10 cases of benign tumor and 1 case of low-grade sarcoma. After 0.6-16 years of follow-up, the operation effect was satisfactory. CONCLUSION: Most of these tumors are papillary fibroelastoma located on the mitral valve, and surgical operation is the best strategy for cardiac primary valve tumors.

AMPK activation serves a critical role in mitochondria quality control via modulating mitophagy in the heart under chronic hypoxia.

Mitochondrial biogenesis is one of the generally accepted regulatory mechanisms in the heart under chronic hypoxia. The precise quantity and quality control of mitochondria is critical for the survival and function of cardiomyocytes. Mitochondrial autophagy, also known as mitophagy, which selectively eliminates dysfunctional and unwanted mitochondria, is the most important type of mitochondrial quality control. However, the detailed molecular mechanisms of mitophagy in cardiomyocytes have been largely undefined. The present study investigated the role of adenosine 5'­monophosphate­activated protein kinase (AMPK) in mitophagy regulation in cardiomyocytes under chronic hypoxia. H9c2 cells were cultured under hypoxic conditions (1% O2) for different time periods. Mitochondrial biogenesis was confirmed and hypoxia was found to induce the collapse of mitochondrial membrane potential (ΛΨm) and increase the number of dysfunctional mitochondria. As expected, mitochondrial autophagy was increased significantly in cardiomyocytes exposed to hypoxic conditions for 48 h. AMPK was activated under hypoxia. Notably, when the activation of AMPK was enhanced by the AMPK agonist AICAR, mitochondrial autophagy was increased accordingly. By contrast, when AMPK activation was blocked, mitochondrial autophagy was decreased and cardiomyocyte apoptosis was increased. In conclusion, in the present study, mitophagy was activated and played a crucial role in cardioprotection under chronic hypoxia. AMPK was involved in mitophagy regulation, thereby providing a potential therapeutic target for heart diseases associated with chronic hypoxia.

The Second-Generation Maturation Inhibitor GSK3532795 Maintains Potent Activity Toward HIV Protease Inhibitor-Resistant Clinical Isolates.

BACKGROUND: Protease inhibitor (PI)-resistant HIV-1 isolates with primary substitutions in protease (PR) and secondary substitutions in Gag could potentially exhibit cross-resistance to maturation inhibitors. We evaluated the second-generation maturation inhibitor, GSK3532795, for activity toward clinical isolates with genotypic and phenotypic characteristics associated with PI resistance (longitudinal). METHODS: Longitudinal clinical isolates from 15 PI-treated patients and 7 highly PI-resistant (nonlongitudinal) viruses containing major and minor PI resistance-associated mutations were evaluated for GSK3532795 sensitivity. Phenotypic sensitivity was determined using the PhenoSense Gag/PR assay (Monogram Biosciences) or in-house single- and multiple-cycle assays. Changes from baseline [CFB; ratio of post- to pre-treatment FC-IC50 (fold-change in IC50 versus wild-type virus)] <3 were considered to be within the no-effect level. RESULTS: All nonlongitudinal viruses tested were sensitive to GSK3532795 (FC-IC50 range 0.16-0.68). Among longitudinal isolates, all post-PI treatment samples had major PI resistance-associated mutations in PR and 17/21 had PI resistance-associated changes in Gag. Nineteen of the 21 post-PI treatment samples had GSK3532795 CFB <3. Median (range) CFB was 0.83 (0.05-27.4) [Monogram (11 patients)] and 1.5 (1.0-2.2) [single-cycle (4 patients)]. The 2 post-PI treatment samples showing GSK3532795 CFB >3 (Monogram) were retested using single- and multiple-cycle assays. Neither sample had meaningful sensitivity changes in the multiple-cycle assay. Gag changes were not associated with an increased GSK3532795 CFB. CONCLUSIONS: GSK3532795 maintained antiviral activity against PI-resistant isolates with emergent PR and/or Gag mutations. This finding supports continued development of GSK3532795 in treatment-experienced patients with or without previous PI therapy.

A method for activation of endogenous acid-sensing ion channel 1a (ASIC1a) in the nervous system with high spatial and temporal precision.

Protons activate acid-sensing ion channel 1a (ASIC1a) in the central nervous system (CNS) although the impact of such activation on brain outputs remains elusive. Progress elucidating the functional roles of ASIC1a in the CNS has been hindered by technical difficulties of achieving acidification with spatial and temporal precision. We have implemented a method to control optically the opening of ASIC1a in brain slices and also in awake animals. The light-driven H(+) pump ArchT was expressed in astrocytes of mouse cortex by injection of adenoviral vectors containing a strong and astrocyte-specific promoter. Illumination with amber light acidified the surrounding interstitium and led to activation of endogenous ASIC1a channels and firing of action potentials in neurons localized in close proximity to ArchT-expressing astrocytes. We conclude that this optogenetic method offers a minimally invasive approach that enables examining the biological consequences of ASIC1a currents in any structure of the CNS and in the modulation of animal behaviors.

Fetal lung epithelial ion channels relocate in the cell membrane during late gestation.

Near the end of gestation, the direction of ion and fluid flow across the alveolar epithelium rapidly changes from secretion to absorption. Thus, the relative cell membrane location of epithelial Na channels (ENaCs) and cystic fibrosis transmembrane regulator (CFTR) Cl channels during late fetal lung development and after maternal interleukin-1ß (IL-1ß) pretreatment was the focus of our study. Western blot analysis after sucrose gradient separation of caveolin-1-(Cav-1)-rich membrane regions (CRR) and Cav-1-poor membrane (non-CRR) revealed primary CRR ENaC localization at gestation day (GD) 61 in guinea pigs. Correlating with the natural induction of distal lung fluid absorption, ENaC appeared in the non-CRR cell membrane regions at GD68. Conversely, CFTR was present in the non-CRR cell membrane regions at GD61 and in the CRRs at GD68. IL-1ß-induced conversion to distal lung fluid absorption at GD61 was associated with ENaC non-CRR presence and CFTR CRR presence, suggesting that relative ENaC and CFTR locations induced distal lung fluid absorption and decreased fluid secretion. Instilling fetal lungs with the CRR-disrupting agent methyl-ß-cyclodextrin resulted in the conversion from lung fluid secretion to absorption and ENaC non-CRR presence at GD61. Coimmunoprecipitation of Cav-1 with α- and ß-ENaC demonstrated reduced coimmunoprecipitation with increased GD and after IL-1ß pretreatment. On the other hand, coimmunoprecipitation of Cav-1 with CFTR demonstrated increased coimmunoprecipitation with increasing GD and after IL-1ß pretreatment. This concept may provide novel molecular mechanisms for the rapid transition from fetal distal lung fluid secretion to absorption in near-term lungs.

Outlines of the pore in open and closed conformations describe the gating mechanism of ASIC1.

The proton-activated sodium channel ASIC1 belongs to the ENaC/Degenerins family of ion channels. Little is known about gating of the pore in any member of this class. Here we outline the shape of the ion pathway of ASIC1 in the open and closed conformations by measuring apparent rates of cysteine modification by thiol-specific reagents in the two transmembrane helices that form the pore (TM1 and TM2). Closed channels have a narrowing in the external end of the pore, whereas open channels have a narrowing midway, the length of TM2 that serves as selectivity filter. Thus, gating of the pore entails straightening the tilt of TM2 without significant rotation. The findings imply that the external narrowing serves as opening, closing and desensitization gate, and that the selectivity filter of ASIC1 is a transient structure that assembles in the open state and is pulled apart in the closed state.

Lung fluid absorption is induced in preterm guinea pigs ventilated with low tidal volumes.

The objective of this study was to determine if low tidal volume (V(t)) ventilation was beneficial when ventilating preterm fetuses. The authors ventilated preterm guinea pig fetuses at gestation day (GD) 67, 3 days before birth, newborn, and 10-day-old (PD10) guinea pigs with low V(t) (6 mL/kg body weight [bw]) and compared them to age-matched fetuses/animals ventilated with higher potentially injurious V(t) (12 mL/kg bw). Lung fluid absorption was measured after intratracheal instillation of 5% albumin in 0.9% NaCl. Low V(t) ventilation stimulated lung fluid absorption when compared to higher V(t) in all groups. The increased lung fluid absorption in low V(t)-ventilated fetuses was associated with increased α epithelial Na channel (αEnaC) mRNA. However, αENaC and ßENaC protein was unchanged over the 1-hour study. Because stretch induces mitogen-activated protein (MAP) kinase expression and MAP kinases may affect lung fluid absorption, the authors investigated if MAP kinase (MAPK) expression was affected by V(t). Extracellular signal-regulated kinase (ERK) and MAPK/ERK kinase (MEK) were phosphorylated in the higher V(t)-ventilated guinea pig fetuses. This suggested that a reduced activation of MAP kinases might explain the increased lung fluid absorption in the low V(t)-ventilated fetuses. Thus these data suggest that low V(t) ventilation increases fetal lung fluid absorption and thus may be preferential to use clinically.