reversal agents
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2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Jocelyn T. Kim ◽  
Tian-Hao Zhang ◽  
Camille Carmona ◽  
Bryanna Lee ◽  
Christopher S. Seet ◽  
...  

AbstractHIV is difficult to eradicate due to the persistence of a long-lived reservoir of latently infected cells. Previous studies have shown that natural killer cells are important to inhibiting HIV infection, but it is unclear whether the administration of natural killer cells can reduce rebound viremia when anti-retroviral therapy is discontinued. Here we show the administration of allogeneic human peripheral blood natural killer cells delays viral rebound following interruption of anti-retroviral therapy in humanized mice infected with HIV-1. Utilizing genetically barcoded virus technology, we show these natural killer cells efficiently reduced viral clones rebounding from latency. Moreover, a kick and kill strategy comprised of the protein kinase C modulator and latency reversing agent SUW133 and allogeneic human peripheral blood natural killer cells during anti-retroviral therapy eliminated the viral reservoir in a subset of mice. Therefore, combinations utilizing latency reversal agents with targeted cellular killing agents may be an effective approach to eradicating the viral reservoir.


2021 ◽  
Author(s):  
Mohammed Aldhaeefi ◽  
Abdulrahman Alshaya ◽  
Khalid Bin Saleh ◽  
Omar Alshaya ◽  
Hisham Badreldin

This chapter is intended to discuss the available oral anticoagulants, including vitamin K antagonists and the Direct Oral Anticoagulants such as dabigatran, apixaban, rivaroxaban, and edoxaban. It will review their basic pharmacology, pharmacokinetics, pharmacodynamics, dosage forms, clinical indications, and place in therapy. Finally, this chapter will also discuss the currently available reversal agents.


2021 ◽  
Vol 11 (1) ◽  
pp. 1
Author(s):  
Stefan Hofer ◽  
Christoph J. Schlimp ◽  
Sebastian Casu ◽  
Elisavet Grouzi

Early recognition of coagulopathy is necessary for its prompt correction and successful management. Novel approaches, such as point-of-care testing (POC) and administration of coagulation factor concentrates (CFCs), aim to tailor the haemostatic therapy to each patient and thus reduce the risks of over- or under-transfusion. CFCs are an effective alternative to ratio-based transfusion therapies for the correction of different types of coagulopathies. In case of major bleeding or urgent surgery in patients treated with vitamin K antagonist anticoagulants, prothrombin complex concentrate (PCC) can effectively reverse the effects of the anticoagulant drug. Evidence for PCC effectiveness in the treatment of direct oral anticoagulants-associated bleeding is also increasing and PCC is recommended in guidelines as an alternative to specific reversal agents. In trauma-induced coagulopathy, fibrinogen concentrate is the preferred first-line treatment for hypofibrinogenaemia. Goal-directed coagulation management algorithms based on POC results provide guidance on how to adjust the treatment to the needs of the patient. When POC is not available, concentrate-based management can be guided by other parameters, such as blood gas analysis, thus providing an important alternative. Overall, tailored haemostatic therapies offer a more targeted approach to increase the concentration of coagulation factors in bleeding patients than traditional transfusion protocols.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jin-Feng Xu ◽  
Yan Wan ◽  
Fei Tang ◽  
Lu Chen ◽  
Yu Yang ◽  
...  

Chemoresistance has become a prevalent phenomenon in cancer therapy, which alleviates the effect of chemotherapy and makes it difficult to break the bottleneck of the survival rate of tumor patients. Current approaches for reversing chemoresistance are poorly effective and may cause numerous new problems. Therefore, it is urgent to develop novel and efficient drugs derived from natural non-toxic compounds for the reversal of chemoresistance. Researches in vivo and in vitro suggest that ginsenosides are undoubtedly low-toxic and effective options for the reversal of chemoresistance. The underlying mechanism of reversal of chemoresistance is correlated with inhibition of drug transporters, induction of apoptosis, and modulation of the tumor microenvironment(TME), as well as the modulation of signaling pathways, such as nuclear factor erythroid-2 related factor 2 (NRF2)/AKT, lncRNA cancer susceptibility candidate 2(CASC2)/ protein tyrosine phosphatase gene (PTEN), AKT/ sirtuin1(SIRT1), epidermal growth factor receptor (EGFR)/ phosphatidylinositol 3-kinase (PI3K)/AKT, PI3K/AKT/ mammalian target of rapamycin(mTOR) and nuclear factor-κB (NF-κB). Since the effects and the mechanisms of ginsenosides on chemoresistance reversal have not yet been reviewed, this review summarized comprehensively experimental data in vivo and in vitro to elucidate the functional roles of ginsenosides in chemoresistance reversal and shed light on the future research of ginsenosides.


2021 ◽  
Author(s):  
Laurent Hany ◽  
Marc-Olivier Turmel ◽  
Corinne Barat ◽  
Michel Ouellet ◽  
Michel J. Tremblay

While combination antiretroviral therapy maintains undetectable viremia in People Living With HIV (PLWH), a life-long treatment is necessary to prevent viremic rebound after therapy cessation. This rebound seemed mainly caused by long lived HIV-1 latently infected cells reversing to a viral productive status. Reversing latency and elimination of these cells by the so-called shock and kill strategy is one of the main investigated leads to achieve an HIV-1 cure. Small molecules referred as latency reversal agents (LRAs) proved to efficiently reactivate latent CD4 + T cells. However, LRAs impact on de novo infection or HIV-1 production in productively infected macrophages remain elusive. Nontoxic doses of bryostatin-1, JQ1 and romidepsin were investigated in human monocyte-derived macrophages (MDMs). Treatment with bryostatin-1 or romidepsin resulted in a downregulation of CD4 and CCR5 receptors respectively, accompanied by a reduction of R5 tropic virus infection. HIV-1 replication was mainly regulated by receptor modulation for bryostatin-1, while romidepsin effect rely on upregulation of SAMHD1 activity. LRA stimulation of chronically infected cells did not enhance neither HIV-1 production nor gene expression. Surprisingly, bryostatin-1 caused a major decrease in viral production. This effect was not viral strain specific but appears to occur only in myeloid cells. Bryostatin-1 treatment of infected MDMs led to decreased amounts of capsid and matrix mature proteins with little to no modulation of precursors. Our observations revealed that bryostatin-1-treated myeloid and CD4 + T cells are responding differently upon HIV-1 infection. Therefore, additional studies are warranted to more fully assess the efficiency of HIV-1 eradicating strategies. Importance HIV-1 persists in a cellular latent form despite therapy that quickly propagates infection upon treatment interruption. Reversing latency would contribute to eradicate these cells, closing a gap to a cure. Macrophages are an acknowledged HIV-1 reservoir during therapy and are suspected to harbor latency establishment in vivo . Yet, the impact of latency reversal agents (LRAs) on HIV-1 infection and viral production in human macrophages is poorly known but nonetheless crucial to probe the safety of this strategy. In this in vitro study, we discovered encouraging anti-replicative features of distinct LRAs in human macrophages. We also described a new viral production inhibition mechanism by protein kinase C agonists which is specific to myeloid cells. This study provides new insights on HIV-1 propagation restriction potentials by LRAs in human macrophages and underline the importance of assessing latency reversal strategy on all HIV-1 targeted cells.


2021 ◽  
Author(s):  
Ladan Panahi ◽  
George Udeani ◽  
Michael Horseman ◽  
Jaye Weston ◽  
Nephy Samuel ◽  
...  

Pulmonary embolism management has typically been accomplished with anticoagulant treatment that includes parenteral heparins and oral vitamin K antagonists. Even though heparins and oral vitamin K antagonists continue to play a role in pulmonary embolism management, other newer available options have somewhat reduced the role of heparins and vitamin K antagonists in pulmonary embolism management. This reduction in utilization involves their toxicity profile, clearance limitations, and many drug and nutrient interactions. New direct oral anticoagulation therapies have led to more available options in the management of pulmonary embolism in the inpatient and outpatient settings. More evidence and research are now available about reversal agents and monitoring parameters regarding these newer agents, leading to more interest in administering them for safe and effective pulmonary embolism management. Current research and literature have also helped direct the selection of appropriate use of pharmacological management of pulmonary embolism based on the specific population such as patients with liver failure, renal failure, malignancy, and COVID-19.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4271-4271
Author(s):  
Michael T. Francisco ◽  
Cecilia Arana Yi ◽  
Leslie Padrnos ◽  
Shienna Braga ◽  
Jill Adamski

Abstract Introduction: The management of bleeding associated with direct oral anticoagulants (DOACs) is challenging and associated with high risk of morbidity/mortality despite the use of various reversal agents (Gomez-Outes et al. 2021). Routine tests cannot determine the level of DOAC anticoagulation and reversal agents carry potential prothrombotic complications (Garcia & Crowther 2021). We present an unusual case of a patient requiring emergent surgery with significant post-op bleeding due to profoundly delayed apixaban elimination. Case Description: A 63-year-old female presented to the emergency department (ED) with a 10-day history of worsening abdominal pain, distension, nausea and constipation. Her past medical history was notable for right sided heart failure, COVID-19 pneumonia requiring intubation, tissue mitral valve replacement, and post-op atrial fibrillation for which she was prescribed apixaban 5 mg BID. Her last dose of apixaban had been the night prior to ED presentation. In the ED, a CT of the abdomen revealed a 6 cm partially obstructing lesion involving the mid-sigmoid colon. Findings were consistent with evolving peritonitis and the patient underwent an emergent exploratory laparotomy, sigmoid resection, and end colostomy. Pre-op labs revealed WBC 12.4 x10 9/L, hemoglobin (hgb) 9.2 g/dL, and platelets 318 x10 9/L. Coagulation studies revealed a PT of 28 sec and INR of 2.5. The patient was given prothrombin complex concentrate (PCC) 25 units/kg and 1 mg of vitamin K prior to surgery. Postoperatively, the INR remained elevated, 2.0, and her hgb downtrended from 8.8 g/dL to 7.8 g/dL. On post-op day 1 the patient became hypotensive, with increased abdominal pain/distension, she also started bleeding from her ostomy. The INR was 2.4 and her hgb dropped to 6.0 g/dL. Red blood cells were given along with FFP, vitamin K and a 2 nd dose of PCC. The patient continued to decline, was transferred to the ICU where she was intubated and placed on CRRT. Hematology was consulted for the persistently prolonged PT/INR in the setting of bleeding despite multiple interventions to correct the INR. The patient's last dose of apixaban was ~48 h prior to ICU admission. A rapid heparin anti-Xa assay was performed and upon comparison with an in-house nomogram the result, 1.78 IU/mL, correlated to an apixaban dose between 180-200 ng/ml (average peak levels 2-4 h after administration are 171 ng/mL). This result was confirmed the following day by an apixaban anti-Xa assay, 190 ng/mL. A repeat test performed 11 h later showed a minimal decrease in apixaban indicating impaired clearance. Therapeutic plasma exchange (TPE) was considered for rapid removal of apixaban. We performed a 1.0 plasma volume exchange, using plasma as the replacement fluid, to remove apixaban. Pre and post TPE drug levels were 172 and 108 ng/mL, respectively. Due to an elevated apixaban level the next day, a second TPE was performed which dropped the level to 87 ng/mL. The patient began to improve clinically, with hgb stabilization ~10 g/dL. She was extubated and transferred to a medical floor for further management. Apixaban levels were still measurable, 16 ng/mL, on post op day 8, 11 days after her last dose. Discussion: Apixaban is a highly protein-bound drug (~90%) that is rapidly absorbed in the small intestine with a large Vd (21 L) and a t1/2 of ~12 h. Elimination primarily occurs through the fecal route (Byon et al. 2019). The factors impairing the elimination of the drug in this patient were the following: 1. Pre-op constipation resulting in 10 days without a bowel movement; 2. Minimal bowel function post-op; and 3. Renal failure requiring CRRT after admission to the ICU. This case illustrates the profound effect intestinal obstruction/dysfunction can have on apixaban clearance. It also highlights the importance of laboratory test interpretation when managing coagulopathic patients. TPE is an effective way to remove drugs with high protein binding affinity (Mahmoud et al. 2021). TPE significantly reduced apixaban levels in our patient allowing for hemostasis and clinical improvement. To our knowledge, there are only two case reports regarding the effect of TPE on DOACs, one for apixaban, the other rivaroxaban (Hodulik et al. 2019). Conclusion: TPE can be considered as an option for rapid clearance of apixaban, or other highly protein bound anti-Xa inhibitors, in the setting of delayed elimination or when specific reversal agents are not safe/available. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 41 (05) ◽  
pp. 530-540
Author(s):  
Cina Sasannejad ◽  
Kevin N. Sheth

AbstractWhile anticoagulation and its reversal have been of clinical relevance for decades, recent academic and technological advances have expanded the repertoire of its application in neurological disease. The advent of direct oral anticoagulants provides effective, mechanistically elegant, and relatively safer therapeutic options than warfarin for eligible patients at risk for neurological sequelae of prothrombotic states, particularly given the recent availability of corresponding reversal agents. In this review, we examine the provenance, indications, safety, and reversal tools for anticoagulant medications in the context of neurological disease, with specific attention to acute ischemic stroke, cerebral venous sinus thrombosis, and intracerebral hemorrhage. We will use specific clinical scenarios to illustrate the complex factors that must be considered in the use of anticoagulation, including intracranial pathology such as intracerebral hemorrhage, traumatic brain injury, or malignancy; metabolic complications such as chronic kidney disease; pregnancy; and advanced age.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jerónimo Laiolo ◽  
Priscila Ailin Lanza ◽  
Oscar Parravicini ◽  
Cecilia Barbieri ◽  
Daniel Insuasty ◽  
...  

AbstractP-gp-associated multidrug resistance is a major impediment to the success of chemotherapy. With the aim of finding non-toxic and effective P-gp inhibitors, we investigated a panel of quinolin-2-one-pyrimidine hybrids. Among the active compounds, two of them significantly increased intracellular doxorubicin and rhodamine 123 accumulation by inhibiting the efflux mediated by P-gp and restored doxorubicin toxicity at nanomolar range. Structure–activity relationships showed that the number of methoxy groups, an optimal length of the molecule in its extended conformation, and at least one flexible methylene group bridging the quinolinone to the moiety bearing the pyrimidine favored the inhibitory potency of P-gp. The best compounds showed a similar binding pattern and interactions to those of doxorubicin and tariquidar, as revealed by MD and hybrid QM/MM simulations performed with the recent experimental structure of P-gp co-crystallized with paclitaxel. Analysis of the molecular interactions stabilizing the different molecular complexes determined by MD and QTAIM showed that binding to key residues from TMH 4–7 and 12 is required for inhibition.


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