ABSTRACT
SARS-CoV-2 invades human respiratory epithelial cells via an interaction between its spike RBD protein (SARS-CoV-2 S-RBD) and the host cell receptor angiotensin converting enzyme II (ACE2). Blocking this interaction provides a potent approach to preventing and controlling SARS-CoV-2 infection. In this work, the ability of {beta}-chitosan to block the binding interaction between SARS-CoV-2 S-RBD and ACE2 was investigated. The inhibitory effect of {beta}-chitosan on inflammation induced by the SARS-CoV-2 S-RBD was also studied. Native-PAGE analysis indicated that {beta}-chitosan could bind with ACE2 and the SARS-CoV-2 S-RBD and a conjugate of {beta}-chitosan and ACE2 could no longer bind with the SARS-CoV-2 S-RBD. HPLC analysis suggested that a conjugate of {beta}-chitosan and the SARS-CoV-2 S-RBD displayed high binding affinity without dissociation under high pressure (40 MPa) compared with that of {beta}-chitosan and ACE2. Furthermore, immunofluorescent staining of Vero E6 cells and lungs from hACE2 mice showed that the presence of {beta}-chitosan prevented SARS-CoV-2 S-RBD from binding to ACE2. Meanwhile, {beta}-chitosan could dramatically suppress the inflammation caused by the presence of the SARS-CoV-2 S-RBD both in vitro and vivo. Moreover, the decreased expression of ACE2 caused by {beta}-chitosan treatment was restored by addition of TAPI-1, an inhibitor of the transmembrane protease ADAM17. Our findings demonstrated that {beta}-chitosan displays an antibody-like function capable of neutralizing the SARS-CoV-2 S-RBD and effectively preventing the binding of the SARS-CoV-2 S-RBD to ACE2. Moreover, ADAM17 activation induced by {beta}-chitosan treatment can enhance the cleavage of the extracellular domain of ACE2, releasing the active ectodomain into the extracellular environment, which can prevent the binding, internalization, and degradation of ACE2 bound to the SARS-CoV-2 S-RBD and thus diminish inflammation. Our study provides an alternative avenue for preventing SARS-CoV-2 infection using {beta}-chitosan.
ABSTRACT
<p><b>OBJECTIVE</b>To compare activation and concentration of insulin, and blood glucose control in patients between insulin added into "all in one" bags and syringes at parenteral nutrition (PN).</p><p><b>METHODS</b>From April 2006 to August 2006, 20 consecutive patients after gastrointestinal operations were recruited and randomized to instillation group and pump group. In instillation group, the insulin was directly added into PN and transfused. In pump group, the insulin was added into syringes and transfused by infusion pump. Activation and concentration of insulin, and blood glucose in patients were measured at beginning infusion, infused 1000 ml, infused 2000 ml, and remained 100 ml daily for the first 3 days after operation.</p><p><b>RESULTS</b>There was a tendency of decrease for the activation and concentration of insulin in both groups with the time. There was no significant difference of activation of insulin between the two groups (P = 0.347). There were no significant differences of blood glucoses between the two groups, and between the four time points in each groups (P > 0.05). There were no complications association with blood glucoses in the two groups.</p><p><b>CONCLUSIONS</b>Both of activation and concentration of insulin at PN decreased gradually and slightly with the time no matter the ways of insulin infusion. Activation of insulin and blood glucoses in patients are no significant differences between the two groups. Insulin can be safely added into "all in one" bags at PN.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Blood Glucose , Metabolism , Double-Blind Method , Hypoglycemic Agents , Blood , Infusions, Intravenous , Methods , Insulin , Blood , Parenteral NutritionABSTRACT
<p><b>OBJECTIVE</b>To compare the differences of injuries and recovery between video-assisted thoracoscopic surgery (VATS) and mini-thoracotomy (MT) in patients with clinical early stage non-small cell lung cancer (NSCLC) after lobectomy.</p><p><b>METHODS</b>From March 2004 to December 2006, 47 consecutive patients with early stage NSCLC with a diameter of tumor less than 6 cm were recruited and randomized to VATS group and MT group. Incision length, duration of operation and intraoperative blood loss were recorded. Postoperative pain was assessed using a visual analogue scale before operation and daily for the first 7 days after operation. The serum levels of interleukin-6 (IL-6) and interleukin-10 (IL-10) were measured by cytometric bead array before operation and at 4, 24, and 48 h after operation. Karnofsky performance status (KPS) was assessed before operation and daily for the first 7 days after operation.</p><p><b>RESULTS</b>Incision length was (6.0 +/- 0. 9) cm in the VATS group and (12.5 +/- 1.5) cm in the MT group. There was no significant difference in duration of operation and intraoperative blood loss between the VATS group and the MT group. Postoperative pain was significantly less in the VATS group in the 5th to 7th day postoperatively (P < 0.05). There was no significant difference of serum concentrations of IL-6 and IL-10 between the VATS group and the MT group at 4, 24, and 48 h after operation. KPS score was significantly higher in the VATS group on 2nd to 7th day postoperatively (P < 0.05).</p><p><b>CONCLUSION</b>Compared with MT, VATS for lobectomy has less postoperative pain, faster recovery, but can't reduce postoperative release of cytokines.</p>
