Secreted alpha-toxin and surface-localized clumping factor A (ClfA) are key virulence determinants in
bloodstream infections. We previously demonstrated that prophylaxis with a multimechanistic ...monoclonal antibody (MAb) combination against alpha-toxin (MEDI4893*) and ClfA (11H10) provided greater strain coverage and improved efficacy in an
lethal bacteremia model. Subsequently, 11H10 was found to exhibit reduced affinity and impaired inhibition of fibrinogen binding to ClfA002 expressed by members of a predominant hospital-associated methicillin-resistant
(MRSA) clone, ST5. Consequently, we identified another anti-ClfA MAb (SAR114) from human tonsillar B cells with >100-fold increased affinity for three prominent ClfA variants, including ClfA002, and potent inhibition of bacterial agglutination by 112 diverse clinical isolates. We next constructed bispecific Abs (BiSAbs) comprised of 11H10 or SAR114 as IgG scaffolds and grafted anti-alpha-toxin (MEDI4893*) single-chain variable fragment to the amino or carboxy terminus of the anti-ClfA heavy chains. Although the BiSAbs exhibited
potencies similar to those of the parental MAbs, only 11H10-BiSAb, but not SAR114-BiSAb, showed protective activity in murine infection models comparable to the respective MAb combination.
activity with SAR114-BiSAb was observed in infection models with
lacking ClfA. Our data suggest that high-affinity binding to ClfA sequesters the SAR114-BiSAb to the bacterial surface, thereby reducing both alpha-toxin neutralization and protection
These results indicate that a MAb combination targeting ClfA and alpha-toxin is more promising for future development than the corresponding BiSAb.
Coagulation disorders disrupt the delicate balance between clot formation and prevention. Various coagulopathies involve abnormal clotting as a manifestation. Rakta Pravarthana Churna (RPC) is an ...Ayurvedic formulation designed for external application during Rakta Mokshana to address Apravarthana or clotting tendencies. Aims & Objectives: The in-vitro study aims to evaluate its anticoagulant (thrombolytic) activity using blood samples from healthy human volunteers. Materials & Methods: The clot lysis activity of aqueous and alcohol extracts of Rakta Pravarthana churna at two different concentrations (5% & 20%) along with streptokinase as a positive control and distilled water and alcohol as a negative control was carried out. Results: The aqueous extracts showed clot lysis activity whereas alcoholic extracts did not exhibit evidently significant clot lysis. Discussion: In comparison with positive control (streptokinase), aqueous extract of RPC at 5% concentration showed 10.76% more clot lysis activity, aqueous extract of RPC at 20% concentration showed 14.31% more activity. Conclusion: Aqueous extracts of RPC promote clot dissolution, while alcoholic extracts displayed inhibitory effects. These findings show the complexity of Ayurvedic drug interactions with coagulation processes. The study contributes to the understanding of anticoagulation potential of RPC and its scope for potential therapeutic applications.
The Amyloid-β (Aβ) peptide is a major component of the amyloid plaques associated with Alzheimer's disease (AD). Recent studies suggest that the most toxic forms of Aβ are small, soluble oligomeric ...aggregates. Here, we report the isolation and characterization of a single-chain variable domain (scFv) antibody isolated against oligomeric Aβ using a protocol developed in our laboratory that combines phage display technology and atomic force microscopy (AFM). Starting with a randomized, single framework phage display library, after three rounds of selection against oligomeric Aβ, we identified an scFv that bound oligomeric Aβ specifically, but not monomeric or fibrillar forms. The anti-oligomeric scFv inhibits Aβ aggregation and toxicity, and reduces the toxicity of preformed oligomeric Aβ towards human neuroblastoma cells. When used to probe samples of human brain tissue, the scFv reacted with AD tissue but not a healthy control or Parkinson's disease brain samples. The anti-oligomeric Aβ scFv therefore has potential therapeutic and diagnostic applications in specifically targeting or identifying the toxic morphologies of Aβ in AD brains.
Accumulation and deposition of beta amyloid (Abeta) play a critical role in the pathogenesis of Alzheimer's Disease (AD), and numerous approaches to control Abeta aggregation are being actively ...pursued. Brain Abeta levels are controlled by the action of several proteolytic enzymes such as neprilysin (NEP), insulin degrading enzyme (IDE) and plasmin. While up-regulation of these enzymes increased clearance of Abeta in transgenic mouse models of AD, these enzymes have other natural substrates and multiple cleavage sites in Abeta complicating their use for treating AD. Alternatively, immunotherapeutic approaches to clear Abeta are gaining interest. Active and passive immunization studies with Abeta can reduce plaque burden and memory loss, but clinical trials were stopped due to meningioencephalitis in some patients. Naturally occurring proteolytic antibodies have been shown to cleave Abeta, and their serum titers are increased in patients with AD reflecting a protective autoimmune response. These antibodies however cannot cross the blood brain barrier and depend entirely on peripheral clearance to clear Abeta. A potentially non-inflammatory approach to facilitate Abeta clearance and reduce toxicity is to promote hydrolysis of Abeta at its alpha-secretase site using affinity matured single chain antibody fragments (scFvs). Bispecific antibodies consisting of a proteolytic scFv and a targeting scFv can be engineered to selectively supplement and target extracellular alpha-secretase activity and to target toxic Abeta forms facilitating their degradation and clearance without generating an immune response. This strategy represents a suitable paradigm for treating other neurological diseases such as Parkinson's Disease, Lou Gehrig's Disease, and spongiform encephalopathies.
Programs designed to address domestic violence often name empowerment of women as a major program goal. However, programs do not necessarily define what empowerment for survivors of domestic violence ...entails. This review examines the literature on empowerment, including characteristics of an empowerment process and critiques of empowerment. Diversity of goals for empowerment and differences in access to resources for women experiencing domestic violence are explored as two major factors that should inform program development. Recommendations are offered for developing programs to address domestic violence that support women engaged in an empowerment process.
OBJECTIVESCharacteristics of drug-related problems and related patient harm has not been evaluated in critically ill patients with decompensated cirrhosis. Our objectives were to identify ...characteristics and incidence rate of drug-related problems and related preventable harm in critically ill patients with decompensated liver cirrhosis.
PATIENTS AND METHODSA prospective observational study was conducted from February 2018 to January 2019 in 10-bed medical intensive care unit of a tertiary care hospital. Medication charts of 78 patients diagnosed with decompensated cirrhosis were reviewed by the clinical pharmacist. Pharmaceutical care-related standard tools were applied for classification of drug-related problems and their severity of outcomes.
RESULTSA total of 394 drug-related problems with an incidence rate of 298.48 per 1000 patient medical intensive care unit-day were identified. Most common drug-related problems were drug-drug interaction (48.7%) followed by guideline nonconformity (15.5%), inappropriate drug form (11.9%), and contraindication (9.6%). Approximately 27% of drug-related problems induced preventable harm, which included temporary harm (19.8%), permanent harm (5.8%), and death (0.8%). The incidence rate of preventable harm was found to be 78.78 per 1000 patient medical intensive care unit-day. Nonsteroidal anti-inflammatory drugs were the most common medications involved in drug-drug interaction, guideline nonconformity, and contraindication which led to gastrointestinal bleeding (24%) and worsening of renal function (11.5%).
CONCLUSIONDrug-related problems occurred commonly in critically ill patients with decompensated liver cirrhosis and induced preventable harm which jeopardized the safety of these vulnerable patients. Clinical pharmacist’s intervention is essential for identification of drug-related problems and related preventable harm among these patients.
Mixed Lineage Kinase 3 (MLK3) is a mitogen‐activated protein (MAP) kinase kinase kinase (MAP3K) that activates multiple MAPK signaling pathways in response to cytokines and stress stimuli. MLK3 is ...important for ovarian cancer cell proliferation and invasion. However, few upstream regulators of MLK3 are known, and MLK3 subcellular localization in ovarian cells is not well understood. LATS (Large Tumor Suppressor), a Ser/Thr kinase, is activated by cell‐cell contact to inhibit proliferation, and also regulates apoptosis and mitotic exit. We observed that confluent ovarian epithelial cells had high levels of phosphorylated, activated LATS (p‐LATS). Furthermore, ovarian cancer cells had substantially lower amounts of p‐LATS in comparison to ovarian epithelial cells. Using confocal microscopy and cell fractionation, we found that MLK3 is both cytoplasmic and nuclear in ovarian cells. Co‐immunoprecipitation assays indicated that LATS interacts with MLK3 and promotes MLK3/14‐3‐3 association and MLK3 cytoplasmic localization; thereby linking the MAPK and Hippo signaling pathways. In conclusion, our results identify LATS as a novel regulator of MLK3 that affects MLK3 subcellular localization in ovarian epithelial cells.
Support or Funding Information
R15‐CA199164
This is from the Experimental Biology 2019 Meeting. There is no full text article associated with this published in The FASEB Journal.
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