Different Mechanisms Of Action Research Articles

The use of statins and inhibitors of proprotein convertase subtilisin-kexin type 9 (PCSK 9) in patients with dyslipidemia

Scientific relevance. According to the WHO data, cardiovascular diseases rank first as the cause of human death. In 2022, 18,601,923 people died from cardiovascular diseases, which amounted to 33 % of the total mortality in the world. Malignant neoplasms rank second with 9,958,133 deaths, representing 17.6 % of total mortality. Among cardiovascular diseases, ischemic heart disease (IHD), the pathogenesis of which is associated with impaired cholesterol and lipoprotein metabolism, is leading. The use of statin drugs is recommended as a first-line lipid-lowering therapy. As an alternative to HMG-CoA reductase inhibitors (statins), proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9) were discovered in 2003, however, they are less popular due to insuf ficient data on these drugs and their costliness. Purpose of the work: to study the safety of using proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in patients with dyslipidemia and compare the advantages and disadvantages in relation to the ef fects of HMG-CoA reductase (statins). Discussion: The analysis of literature data has shown that the most frequent manifestations of intolerance to statins are muscle symptoms. The main mechanisms of statin-associated complications are mediated by inhibition of HMG-CoA reductase, as well as by the effect of drugs on cellular and subcellular processes, skeletal muscles and genetic features of patients. PCSK9 inhibitors have a fundamentally different mechanism of action — they bind and inactivate PCSK9, which leads to a decrease of low-density lipoprotein cholesterol in the blood level. A small number of undesirable reactions have been identified for drugs of this group, the most important of which is immunogenicity. However, even if patients have antibodies to PCSK9 inhibitor, the efficacy of the drug in reducing the level of low-density lipoproteins remains high.Conclusion. In medical studies, PCSK9 inhibitors have been shown to perform better compared to HMG-CoA reductase inhibitors; meanwhile, patients continue to use statins as lipid-lowering medications.

PCSK9-directed therapies: an update.

Two large cardiovascular outcomes trials of monoclonal antibodies against proprotein convertase subtilisin/kexin type 9 (PCSK9) demonstrated that therapeutic inhibition of extracellular PCSK9 markedly reduces LDL cholesterol concentration and cardiovascular risk. Several novel strategies to inhibit PCSK9 function are in development. Different mechanisms of action may determine specific properties with potential relevance for patient care. For the monoclonal antibodies evolocumab und alirocumab as first-generation PCSK9 inhibitors, follow-up data of up to 8 years of exposure complement the information on efficacy and safety available from outcome trials. For the small-interfering RNA inclisiran as second-generation PCSK9 inhibitor, several phase III trials have been published and a cardiovascular outcome trial has completed recruitment and is ongoing. Third-generation PCSK9 inhibitors encompass, among others, orally available drugs such as MK-0616 and the fusion protein lerodalcibep. Additional strategies to inhibit PCSK9 include vaccination and gene editing. Long-term inhibition of PCSK9 with monoclonal antibodies is safe and conveys sustained cardiovascular benefit. Novel strategies to inhibit PCSK9 function such as orally available drugs, RNA targeting, and one-time treatment with gene editing may further enhance the therapeutic armamentarium and enable novel preventive strategies.

Topical issues of therapy for patients with ulcerative colitis

Ulcerative colitis is an autoimmune disease characterized by ulcerative destructive processes in the mucous membrane of the colon. Despite advances in the pharmaceutical industry, its prevalence in the world is increasing every year. The etiology of UC is currently unknown to the end. According to modern concepts, ulcerative colitis is considered as a multifactorial disease, in the pathogenesis of which genetic determinism, disorders of the intestinal microbiota with a decrease in populations of anaerobic bacteria in combination with the trigger action of environmental factors are discussed. With high probability, the leading pathogenetic mechanisms of the disease are associated with the polarization of the Th2-type immune response, which is characterized by the synthesis of IL-4, IL-5, IL-9 and IL-13, which is regulated by STAT-5 and Gata-3. During the development of the disease, Th17, a type of immune response, is also involved in the immunopathological process, but with the participation of transcription factors STAT-3 and ROR-yt and the synthesis of IL-17, IL-2, IL-6, IL-26 and IL-22, as well as chemokine CCL20. Diet and lifestyle are part of the global guidelines for the treatment of patients with ulcerative colitis. Derivatives of 5-aminosalicylic acid are used as basic therapy preparations: combined preparations and preparations of pure 5-aminosalicylic acid. Nevertheless, the administration of systemic glucocorticosteroids is indicated to control the activity of the disease. However, as our practice shows, they are effective, but only at the first attack and subsequent 2-3 relapses of the disease, followed by a high incidence of hormone resistance. To date, there are modern medicines with a different mechanism of action, allowing achieving stable remission and improving the quality of life of patients. Among them, JAK -tofacitinib inhibitors are of particular interest in the treatment of ulcerative colitis. This is the first oral drug capable of inducing and maintaining steroidal remission. The choice of a particular drug is determined by the experience of use, cost and national recommendations.

New possibilities of overcoming pharmacoresistance in epilepsy

Despite the presence of antiepileptic drugs with different mechanisms of action and application points, almost a third of patients still remain resistant to drug therapy. In such patients, the risk of physical and mental injuries, depression, premature death increases, and the quality and standard of living decreases.Objective. To study the mechanisms of formation of pharmacoresistance in epilepsy and to evaluate possible ways to overcome it based on the analysis of current scientific publications containing information on this topic.Results. The proposed pathophysiological mechanisms of the formation of drug resistance reflect the target hypothesis, the carrier hypothesis, pharmacokinetic theory and neural network theory. However, they are based on preclinical studies and do not have a comprehensive explanation for the appearance of this phenomenon. Surgical treatment remains the most studied and most commonly used approach. Both the usual resection of the epileptogenic part of the brain and new less crippling interventions are used: laser ablation and stereotactic radiosurgery. As an alternative, polytherapy schemes, invasive and non-invasive neurostimulation techniques, and diet therapy can be considered.Conclusions. Insensitivity to antiepileptic drugs remains a major problem in epileptology, and to overcome it, new methods are being sought and developed to influence the presumed pathogenetic targets of pharmacoresistant epileptogenesis. Vagus, deep, transcranial neurostimulation, stereotactic surgery, and laser ablation should be considered as new safe and potentially effective techniques.

The Networked Interaction between Probiotics and Intestine in Health and Disease: A Promising Success Story.

Probiotics are known to promote human health either precautionary in healthy individuals or therapeutically in patients suffering from certain ailments. Although this knowledge was empirical in past tomes, modern science has already verified it and expanded it to new limits. These microorganisms can be found in nature in various foods such as dairy products or in supplements formulated for clinical or preventive use. The current review examines the different mechanisms of action of the probiotic strains and how they interact with the organism of the host. Emphasis is put on the clinical therapeutic use of these beneficial microorganisms in various clinical conditions of the human gastrointestinal tract. Diseases of the gastrointestinal tract and particularly any malfunction and inflammation of the intestines seriously compromise the health of the whole organism. The interaction between the probiotic strains and the host's microbiota can alleviate the clinical signs and symptoms while in some cases, in due course, it can intervene in the underlying pathology. Various safety issues of the use of probiotics are also discussed.

Understanding the differential impacts of two antidepressants on locomotion of freshwater snails (Lymnaea stagnalis)

There is growing evidence of negative impacts of antidepressants on behavior of aquatic non-target organisms. Accurate environmental risk assessment requires an understanding of whether antidepressants with similar modes of action have consistent negative impacts. Here, we tested the effect of acute exposure to two antidepressants, fluoxetine and venlafaxine (0–50 µg/L), on the behavior of non-target organism, i.e., freshwater pond snail, Lymnaea stagnalis. As compounds interact with chemical cues in the aquatic ecosystems, we also tested whether the effects altered in the presence of bile extract containing 5α-cyprinol sulfate (5α-CPS), a characterized kairomone of a natural predator, common carp (Cyprinus carpio). Behavior was studied using automated tracking and analysis of various locomotion parameters of L. stagnalis. Our results suggest that there are differences in the effects on locomotion upon exposure to venlafaxine and fluoxetine. We found strong evidence for a non-monotonic dose response on venlafaxine exposure, whereas fluoxetine only showed weak evidence of altered locomotion for a specific concentration. Combined exposure to compounds and 5α-CPS reduced the intensity of effects observed in the absence of 5α-CPS, possibly due to reduced bioavailability of the compounds. The results highlight the need for acknowledging different mechanisms of action among antidepressants while investigating their environmental risks. In addition, our results underline the importance of reporting non-significant effects and acknowledging individual variation in behavior for environmental risk assessment.Graphical

Antibacterial Activity and Mechanisms of Action of Inorganic Nanoparticles against Foodborne Bacterial Pathogens: A Systematic Review

Foodborne disease outbreaks due to bacterial pathogens and their toxins have become a serious concern for global public health and security. Finding novel antibacterial agents with unique mechanisms of action against the current spoilage and foodborne bacterial pathogens is a central strategy to overcome antibiotic resistance. This study examined the antibacterial activities and mechanisms of action of inorganic nanoparticles (NPs) against foodborne bacterial pathogens. The articles written in English were recovered from registers and databases (PubMed, ScienceDirect, Web of Science, Google Scholar, and Directory of Open Access Journals) and other sources (websites, organizations, and citation searching). “Nanoparticles,” “Inorganic Nanoparticles,” “Metal Nanoparticles,” “Metal–Oxide Nanoparticles,” “Antimicrobial Activity,” “Antibacterial Activity,” “Foodborne Bacterial Pathogens,” “Mechanisms of Action,” and “Foodborne Diseases” were the search terms used to retrieve the articles. The PRISMA-2020 checklist was applied for the article search strategy, article selection, data extraction, and result reporting for the review process. A total of 27 original research articles were included from a total of 3,575 articles obtained from the different search strategies. All studies demonstrated the antibacterial effectiveness of inorganic NPs and highlighted their different mechanisms of action against foodborne bacterial pathogens. In the present study, small-sized, spherical-shaped, engineered, capped, low-dissolution with water, high-concentration NPs, and in Gram-negative bacterial types had high antibacterial activity as compared to their counterparts. Cell wall interaction and membrane penetration, reactive oxygen species production, DNA damage, and protein synthesis inhibition were some of the generalized mechanisms recognized in the current study. Therefore, this study recommends the proper use of nontoxic inorganic nanoparticle products for food processing industries to ensure the quality and safety of food while minimizing antibiotic resistance among foodborne bacterial pathogens.

Advances in polysaccharides of natural source of anti-diabetes effect and mechanism.

Diabetes is a chronic disease in metabolic disorder, and the pathology is characterized by insulin resistance and insulin secretion disorder in blood. In current, many studies have revealed that polysaccharides extracted from natural sources with significant anti-diabetic effects. Natural polysaccharides can ameliorate diabetes through different action mechanisms. All these polysaccharides are expected to have an important role in the clinic. Existing polysaccharides for the treatment of diabetes are reviewed, and the mechanism of polysaccharides in the treatment of diabetes and its structural characteristics are described in detail. This article introduced the natural polysaccharide through different mechanisms of action in the treatment of diabetes, including oxidative stress, apoptosis, inflammatory response and regulation of intestinal bacteria. Natural polysaccharides can treat of diabetes by regulating signaling pathways is also a research hotspot. In addition, the structural characteristics of polysaccharides were explored. There are some structure-activity relationships between natural polysaccharides and the treatment of diabetes.

Small-Molecule Approaches to Target Transcription Factors

Dysregulated transcription factor activity is a defining feature of various cancer types. As such, targeting oncogenic transcriptional dependency has long been pursued as a potential therapeutic approach. However, transcription factors have historically been deemed as undruggable targets due to their highly disordered structures and lack of well-defined binding pockets. Nevertheless, interest in their pharmacologic inhibition and destruction has not dwindled in recent years. Here, we discuss new small-molecule-based approaches to target various transcription factors. Ligands with different mechanisms of action, such as inhibitors, molecular glue degraders, and proteolysis targeting chimeras, have recently seen success preclinically and clinically. We review how these strategies overcome the challenges presented by targeting transcription factors. Expected final online publication date for the Annual Review of Cancer Biology, Volume 8 is April 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

From Beach to the Bedside: Harnessing Mitochondrial Function in Human Diseases Using New Marine-Derived Strategies.

Mitochondria are double-membrane organelles within eukaryotic cells that act as cellular power houses owing to their ability to efficiently generate the ATP required to sustain normal cell function. Also, they represent a "hub" for the regulation of a plethora of processes, including cellular homeostasis, metabolism, the defense against oxidative stress, and cell death. Mitochondrial dysfunctions are associated with a wide range of human diseases with complex pathologies, including metabolic diseases, neurodegenerative disorders, and cancer. Therefore, regulating dysfunctional mitochondria represents a pivotal therapeutic opportunity in biomedicine. Marine ecosystems are biologically very diversified and harbor a broad range of organisms, providing both novel bioactive substances and molecules with meaningful biomedical and pharmacological applications. Recently, many mitochondria-targeting marine-derived molecules have been described to regulate mitochondrial biology, thus exerting therapeutic effects by inhibiting mitochondrial abnormalities, both in vitro and in vivo, through different mechanisms of action. Here, we review different strategies that are derived from marine organisms which modulate specific mitochondrial processes or mitochondrial molecular pathways and ultimately aim to find key molecules to treat a wide range of human diseases characterized by impaired mitochondrial function.

Olanzapine, risperidone and ziprasidone differently affect lysosomal function and autophagy, reflecting their different metabolic risk in patients

The metabolic effects induced by antipsychotics in vitro depend on their action on the trafficking and biosynthesis of sterols and lipids. Previous research showed that antipsychotics with different adverse effects in patients cause similar alterations in vitro, suggesting the low clinical usefulness of cellular studies. Moreover, the inhibition of peripheral AMPK was suggested as potential aetiopathogenic mechanisms of olanzapine, and different effects on autophagy were reported for several antipsychotics. We thus assessed, in clinically-relevant culture conditions, the aetiopathogenic mechanisms of olanzapine, risperidone and ziprasidone, antipsychotics with respectively high, medium, low metabolic risk in patients, finding relevant differences among them. We highlighted that: olanzapine impairs lysosomal function affecting autophagy and autophagosome clearance, and increasing intracellular lipids and sterols; ziprasidone activates AMPK increasing the autophagic flux and reducing intracellular lipids; risperidone increases lipid accumulation, while it does not affect lysosomal function. These in vitro differences align with their different impact on patients. We also provided evidence that metformin add-on improved autophagy in olanzapine-treated cells and reduced lipid accumulation induced by both risperidone and olanzapine in an AMPK-dependent way; metformin also increased the production of bile acids to eliminate cholesterol accumulations caused by olanzapine. These results have different clinical implications. We demonstrated that antipsychotics with different metabolic impacts on patients actually have different mechanisms of action, thus supporting the possibility of a personalised antipsychotic treatment. Moreover, we found that metformin can fully revert the phenotype caused by risperidone but not the one caused by olanzapine, that still activates SREBP2.

Folate receptor-mediated delivery system based on chitosan coated polymeric nanoparticles for combination therapy of breast cancer

Combination therapy using two or more drugs with different mechanisms of action is an effective strategy for treating cancer. This is because of the synergistic effect of complementary drugs that enhances their effectiveness. However, this approach has some limitations, such as non-specific distribution of the drugs in the tumor and the occurrence of dose-dependent toxicity to healthy tissues. To overcome these issues, we have developed a folate receptor-mediated co-delivery system that improves the access of chemotherapy drugs to the tumor site. We prepared a nanoplatform by encapsulating paclitaxel (PTX) and curcumin (CUR) in poly(caprolactone)-poly(ethylene glycol)-poly(caprolactone) (PCL-PEG-PCL) co-polymer using a double emulsion method and coating nanoparticles with pH-responsive chitosan-folic acid (CS-FA) conjugate. The nanocarrier’s physicochemical properties were studied, confirming successful preparation with appropriate size and morphology. PTX and CUR could be released synchronously in a controlled and acid-facilitated manner. The dual drug-loaded nanocarrier exhibited excellent anti-tumor efficiency in MDA-MB-231 cells in vitro. The active targeting effect of FA concluded from the high inhibitory effect of dual drug-loaded nanocarrier on MDA-MB-231 cells, which have overexpressed folate receptors on their surface, compared to Human umbilical vein endothelial cells (HUVEC). Overall, the nanoengineered folate receptor-mediated co-delivery system provides great potential for safe and effective cancer therapy.

Bathing in Atopic Dermatitis in Pediatric Age: Why, How and When.

Atopic dermatitis is a chronic inflammatory skin disease. The treatment plays an important role in influencing the patients' quality of life. The basic management consists of appropriate skin cleansing, including bathing and eventually using bathing additives. Recommendations regarding frequency and duration of bathing, water temperature and usefulness of bathing additives are widely different, often leading to confusion among patients. This review aims to give insights into the best bathing practices and the use of bathing additives in atopic dermatitis in children. Several bathing additives, including bleach baths, commercial baby cleansers, bath baby oils and bath salt, appear to be promising adjunctive therapies for atopic dermatitis due to their anti-inflammatory, anti-bacterial, anti-pruritus and skin barrier repair properties through different mechanisms of action. However, their efficacy and safety are not fully understood in some cases. The usefulness of other bath additives, such as acidic and more natural substances (green tea extracts, pine tar, sodium bicarbonate), is still under investigation. Further studies are needed to determine their optimal use to achieve clinical benefit safely.

Comparative effectiveness of pelvic floor muscle training, mirabegron, and trospium among older women with urgency urinary incontinence and high fall risk: a feasibility randomized clinical study

BackgroundUntreated, urgency urinary incontinence (UUI) and overactive bladder (OAB) can precipitate a vicious cycle of decreasing physical activity, social isolation, fear of falling, and falls. Structured behavioral interventions and medications are common initial treatment options, but they elicit their effects through very different mechanisms of action that may influence fall-related outcomes differently. This study will determine the feasibility of conducting a comparative effectiveness, three-arm, mixed methods, randomized clinical trial of a behaviorally based pelvic floor muscle training (PFMT) intervention versus two recent drug options in older women with UUI or OAB who are also at increased risk of falling.MethodsForty-eight women 60 years and older with UUI or OAB who screen positive for increased fall risk will be recruited through the urogynacology and pelvic health clinics of our university health system. Participants will be randomly assigned to one of three 12-week treatment arms: (1) a course of behavioral and pelvic floor muscle training (PFMT) provided by physical therapists; (2) the beta-3 agonist, mirabegron; and (3) the antimuscarinic, trospium chloride. Study feasibility will be established through objective metrics of evaluability, adherence to the interventions, and attrition. We will also assess relevant measures of OAB symptom severity, quality of life, physical activity, incident falls, and concern about falling.DiscussionThe proposed research seeks to ultimately determine if linkages between reduction in UI symptoms through treatment also reduce the risk of falling in this patient population.Trial registrationNCT05880862. Registered on 30 May 2023.

Efficacy and tolerability of rufinamide in the treatment of Lennox–Gastaut syndrome (experience of the Svt. Luka’s Association of Medical Institutions)

Background. Lennox–Gastaut syndrome (LGS) is a classic developmental and epileptic encephalopathy with a debut in childhood, characterized by resistance to therapy, a severe course, and an unfavorable prognosis. Due to the existing difficulties in treatment of LGS, hopes are pinned on development of new antiepileptic drugs with fundamentally different mechanisms of action, aimed specifically at the treatment of this severe form of epilepsy.Rufinamide (Inovelon®) is a new antiepileptic drug registered in the Russian Federation for use in the adjunctive therapy of LGS in patients older than 1 year. The main mechanism of action of rufinamide is the restriction of neuronal discharges associated with the blocking effect on sodium channels (regulation of sodium channels activity by increasing duration of their inactive state), and stabilization of neuronal membranes. The drug has a number of advantages concernung pharmacokinetic parameters and efficacy (including a wide spectrum of antiepileptic activity, good oral absorption, absence of active metabolites, urinary excretion, low affinity for plasma proteins, biotransformation without cytochrome P450 isoenzymes, low risk of drug interactions) and fairly good tolerability. The daily dose of rufinamide varies from 600 mg (with simultaneous administration of valproate) to 1000 mg (if the patient does not take valproate) in children over 4 years of age with a body weight of less than 30 kg and up to 2200–3200 mg in children over 4 years of age with a body weight of more than 30 kg and in adults; in children under 4 years of age, the maximum daily dose in combination with valproate is 30 mg/kg, and without valproic acid – 45 mg/kg.Aim. To analyze the efficacy and tolerability of rufinamide in the treatment of epilepsy based on the long-term experience of using the drug in the Svt. Luka’s Association of Medical Institutions.Materials and methods. We observed 64 patients aged from 1.5 to 26 years (44 men, 20 women) treated with rufinamide (Inovelon®). Among them, the structural etiology LGS was diagnosed in 36 patients, the genetic and presumably genetic etiology LGS – in 28. In all cases, rufinamide was used in accordance with approved indications as an additional antiepileptic drug, more often in combination with valproate, topiramate, levetiracetam or lamotrigine. Titration of the drug was carried out according to the recommendations in the instructions for use, up to a therapeutic dose that ranged from 200 to 1600 mg/day (in most cases from 400 to 1200 mg/day), depending on age and concomitant therapy.Results and conclusion. Remission of all types of seizures was registered in 17 (26.6 %) patients, and a decrease in the incidence of seizures by more than 50 % was recorded in 28 (43.8 %) patients. Of them, 13 patients demonstrated reduction in seizures frequency by more than 75–90 % and remission of one of several types of seizures. In general, the therapeutic effect (reduction of seizures frequency by at least 50 %) was achieved in 45 (70.3 %) of 64 patients. A decrease in seizures frequency of by at least 50 % was observed in 8 (12.5 %) patients; in 10 (15.6 %) patients, rufinamide therapy was not effective; in 1 (1.56 %) case an aggravation of bilateral convulsive seizures was noted when rufinamide was administered.In most cases, rufinamide is well tolerated. Our patients had side effects in 10 (15.6 %) cases. Only in 2 (3.1 %) cases, rufinamide was withdrawn directly due to side effects (the reason for withdrawal in these cases was an allergic reaction and psychosis).The retention rate for therapy lasting 1 year or more is 65.6 % (42 of 64 patients).Thus, our data have demonstrated efficacy and good tolerability of rufinamide in treating epileptic seizures associated with LGS, confirming numerous literature data. However, in our analysis, a higher rate of seizure remission was obtained, although we have included patients with mainly resistant forms of epilepsy in the analysis.

Comparative profiles of lubiprostone, linaclotide, and elobixibat for chronic constipation: a systematic literature review with meta-analysis and number needed to treat/harm

ObjectiveTo comprehensively evaluate the efficacy, safety, patient symptoms, and quality-of-life (QoL) of lubiprostone, linaclotide, and elobixibat as treatment for chronic constipation (CC).DesignSystematic literature review (SLR) and meta-analysis (MA). Literature searches were conducted on PubMed and Embase using the Ovid platform.MethodsSLR including randomized controlled trials (RCTs) and observational studies was conducted to identify the overall efficacy and safety of lubiprostone, linaclotide, and elobixibat. Thereafter, MA was performed using only RCTs. The number needed to treat (NNT) and number needed to harm (NNH) analyses were additionally conducted.Primary and secondary outcome measures The primary outcome was efficacy regarding change in spontaneous bowel movements. Secondary outcomes included safety, constipation-related symptoms, and QoL.ResultsTwenty-four studies met the inclusion criteria for the SLR: 17 RCTs, 4 observational studies, and 3 single-arm trials. Feasibility assessment for the MA resulted in 14 studies available for safety data analysis, and 8 available for efficacy analysis, respectively. Three drugs showed similar efficacy in the MA and NNT analysis. However, the NNH analysis revealed distinct safety profiles: lubiprostone, linaclotide, and elobixibat were linked to the highest risk of nausea, diarrhea, and abdominal pain, respectively.ConclusionThe current study provides an updated overview of the efficacy, safety, patient symptoms, and QoL of the three drugs with different mechanisms of action for CC treatment.The findings could help physicians adopt an individualized approach for treating patients with CC in clinical practice.

A Modified Murine Embryonic Stem Cell Test for Evaluating the Teratogenic Effects of Drugs.

Animal-based test systems have traditionally been used to screen for the potential teratogenic activity of drugs. Still, their deficits in predicting precise human-specific outcomes and ethical concerns have led to a need for alternative approaches. In vitro, teratogenicity testing using cell cultures or other in vitro systems is a potential alternative. Of the different in vitro platforms, the mouse embryonic stem cell test (mEST) is currently the most widely used and validated in vitro test for assessing the potential effects of teratogens on early embryonic development. The mEST involves exposing mouse embryonic stem cells to the test compound and monitoring their differentiation for several days.Nevertheless, its predictive ability was comparatively lower when distinguishing weak developmental toxicants from non-toxic substances. Since then, several modifications and adaptations of the mEST protocol have been developed. This chapter describes an alternative method based on molecular approaches to predict embryotoxicity. This method, originated from the mEST, analyzes the expression of differentiation genes involved in the development of mesoderm, endoderm, and stoderm and allows screening embryo-toxicants with different mechanisms of action. The hanging drops embryoid bodies used in the original mEST protocol have been replaced with monolayer culture, and thus the process has been shortened. In general, the method shows higher predictability compared with the traditional ones.

Prevalence of covid-19 breakthrough after vaccination and adverse effects of vaccines

Objective: To assess the prevalence of breakthrough Covid 19 after vaccination and adverse effects of vaccines. Methodology: A descriptive cross-sectional study was conducted at three mega vaccination centers in Islamabad from December 1, 2021, to May 1, 2022. The sample size consisted of 300 participants (both males and females) in the age range of 30-60 years. To avoid ambiguities in answers, we included only those participants who were fully vaccinated. Among these, 150 were healthy individuals and 150 with co-morbidities, were selected through convenience sampling. Data were collected and analyzed using a pre-designed questionnaire and SPSS version 21. Results: A significant association between breakthrough COVID-19 and age and symptoms were found in fully vaccinated individuals with and without comorbidities. The type of vaccine had a significant association only in individuals without medical illness. No significant side effects of the vaccine or gender association were found in either group. We also found a significant association between breakthrough COVID-19 symptoms and the type of vaccine used. Conclusion: A significant association between vaccine type and breakthrough COVID was observed only in healthy individuals, probably because of their different mechanisms of action.

A synergistic therapy against influenza virus A/H1N1/PR8 by a HA1 specific neutralizing single-domain VL and an RNA hydrolyzing scFv.

The emergence of anti-influenza drug-resistant strains poses a challenge for influenza therapy due to mutations in the virus's surface protein. Recently, there has been increasing interest in combination therapy consisting of two or more drugs as a potential alternative approach, aiming to enhance therapeutic efficacy. In this study, we investigated a novel synergistic therapy with a vertical effect using a single-domain VL-HA1-specific antibody against H1N1/PR8 and a horizontal effect using an RNA catalytic antibody with broad-spectrum influenza antiviral drug. We isolated a single-domain VL-HA1-specific (NVLH8) antibody binding to the virus particles showing a neutralizing activity against influenza virus A, specifically H1N1/PR8, as determined by the reduction in plaque number and lower viral HA protein expression in vitro. The neutralizing antibody likely prevented the viral entry, specifically at the viral genome-releasing step. Additionally, the 3D8 scFv hydrolyzed viral RNAs in the cytoplasm, including mRNA, vRNA, and cRNA in MDCK cells. The combined treatment of neutralizing antibodies for a vertical effect and 3D8 scFv for a horizontal effect produced a synergistic effect providing a novel approach against viral diseases when compared with a single treatment. Our results indicated that combining treatment, in particular two proteins exhibiting different mechanisms of action increased the antiviral activity against the influenza virus.

GSH/pH dual responsive chitosan nanoparticles for reprogramming M2 macrophages and overcoming cancer chemoresistance.

The combination of two or more drugs with different mechanisms of action is a promising strategy for circumventing multidrug resistance (MDR). However, the antitumor effect of nanosystems is usually limited due to the simultaneous release of different payloads at a single location rather than at their respective sites of action. Herein, we report a GSH and pH dual responsive nanoplatform encapsulated with doxorubicin (DOX) and resiquimod (R848) (GPNP) for combinatorial chemotherapy against cancer cells with drug resistance. GPNP possesses a core-shell structure wherein the polymer shell detaches in the acidic and sialic acid (SA)-rich environment. This leads to the release of R848 into the tumor microenvironment (TME), thereby reprogramming M2 macrophages into M1 macrophages and exposing the core CS(DOX)-PBA to kill MCF-7/ADR cells. Additionally, the nitric oxide (NO) generated by M1 macrophages can suppress the P-glycoprotein (P-gp) expression to reduce the efflux of chemotherapy drugs, thus playing a combined role in overcoming MDR. In vitro studies have demonstrated the effectiveness of GPNP in reprogramming M2 macrophages and inducing apoptosis in MCF-7/ADR cells, resulting in enhanced antitumor efficacy. This work proposed an effective combination strategy to combat chemoresistance, providing new insights into the development of innovative combinatorial therapies against MDR tumors.