Residual risk of thromboembolic events despite anticoagulation in Middle Eastern patients with atrial fibrillation. The JoFib study.

OBJECTIVES: To investigate residual risk of thromboembolic events despite anticoagulation in patients with atrial fibrillation form the Middle East. MATERIALS AND METHODS: Using data from the JoFib registry, we described the characteristics of patients treated with anticoagulants (n = 1654) and calculated the incidence rate for thromboembolic events. We constructed multivariable Cox proportional hazard models and calculated the population-attributable fraction to determine clinical factors predictive of residual thromboembolic events. RESULTS: During the one-year follow-up, 57 thromboembolic events occurred (incidence rate 4.1 per 100 person-years). In multivariable time-to-event analysis, prior thromboembolic events (aHR 3.8, 95 %CI 2.2-6.4, p < 0.001) and diabetes (aHR 2.3, 95 %CI 1.3-4.1, p = 0.004) were independently predictive of residual thromboembolism. Percentage of thromboembolic risk attributable to prior thromboembolic events was 30.9 % (95 %CI 13.9-44.6, p = 0.001) and was 37.1 % (95 %CI 8.8-56.6, p = 0.015) for diabetes. Furthermore, the effect of diabetes on thromboembolic events depends on the type of anticoagulant, with diabetes being significantly predictive of thromboembolic events in patients anticoagulated with warfarin (aHR 4.11, 95 %CI 1.81-9.37, p = 0.001), but not non-vitamin K antagonist oral anticoagulants (aHR 1.23, 95 %CI 0.51-2.97, p = 0.643) with a p = 0.045 for interaction. Prior thromboembolism was independently predictive of thromboembolic events in both anticoagulants (aHR 2.67, 95 %CI 1.28-5.58, p = 0.009; aHR 7.33, 95 %CI 3.05-17.65, p < 0.001; respectively; p = 0.084 for interaction). CONCLUSIONS: Middle Eastern patients with atrial fibrillation remain at significant risk of thromboembolism and its recurrence despite anticoagulation, and especially in diabetic patients. Therefore, management should focus on controlling diabetes as well as other modifiable risk factors in addition to antithrombotic therapy.

Sildenafil Effect on Atrial Natriuretic Peptide Level in Pulmonary Hypertensive Rats.

BACKGROUND: Pulmonary Hypertension (PH) leads to changes in pulmonary vascular architecture, hypertrophy of the right ventricle, and heart failure. Sildenafil is a drug that can modulate PH by inducing smooth muscle relaxation and vasodilation. AIMS: To investigate the ability of sildenafil to alleviate the monocritaline (MCT)-induced PH in rats and to estimate the role and its effect on the atrial natriuretic peptide (ANP) levels. METHODS: 28 adult male rats were divided randomly into four groups: Group A (control group; n=7). Group B (MCT-treated group; n=7) was given a single dose of MCT 60 mg/kg subcutaneously. Group C (The reversal group; n=7) received a single dose of MCT 60 mg/kg subcutaneously for three weeks and then sildenafil at 50 mg/kg/day, given daily for another three weeks. Group D (The prevention group; n=7) simultaneously received a single dose of MCT 60 mg/kg subcutaneously and sildenafil daily at 50 mg/kg for three weeks. RESULTS: The animals in the prevention group showed a significant decrease in ANP levels compared to the reversal and MCT-treated groups. This decrease was associated with a significant reduction in the Fulton index ratio in the prevention group compared to the reversal group. The nitric oxide levels were also significantly higher in the reversal group than in the control group. CONCLUSION: Preventive sildenafil treatment was associated with a significant decrease in ANP levels and reduced MCT-induced cardiac hypertrophy in rats.

Sex differences in clinical features, utilization of oral anticoagulant agents, and 1-year outcome in Middle Eastern patients with atrial fibrillation.

OBJECTIVE: Studies have revealed that sex can predict differences in multiple aspects of atrial fibrillation (AF). These differences are underreported in the Middle East. This study aims to describe sex-specific differences in risk factors, symptomatology, management, and outcomes in Middle Eastern patients with AF. METHODS: The JoFib (Jordan-Atrial-Fibrillation) study is an observational, prospective, multicenter, nationwide registry in AF. Comparisons were made between female and male patients using Pearson chi-square and Mann-Whitney U tests. Multivariable regression models were constructed to investigate whether the female sex was predictive of any AF-related outcomes (all-cause death, cardiovascular death, ischemic stroke or systemic embolism [IS/SE], major bleeding, and clinically relevant non-major bleeding). RESULTS: Of 2,020 patients with AF, 54% (n = 1091) were females. Females with AF were older (median age 71 vs. 69, p <.001), but had less heart failure (20.9% vs. 27.2%, p = .001) and coronary artery disease (7.5% vs. 14.7%, p <.001). Females with AF were more symptomatic (74.7% vs. 66.5%, p <.001) and frequently received anticoagulant therapy (84.4% vs. 78.9%, p = .001). Rhythm control was pursued less frequently in females (23.4% vs. 27.3%, p = .04). All studied outcomes occurred with similar frequencies in females and males, and sex was not significantly predictive of any outcome. CONCLUSION: Females with AF are more symptomatic, yet they are treated less with rhythm control. Despite higher risk, females have similar risk-adjusted all-cause cardiovascular death and stroke rates compared to males. Future studies should explore how treatments and interventions can influence quality-of-life and cardiovascular outcomes in females with AF.

Cardiovascular medications used for comorbid diseases in patients with atrial fibrillation. The JoFib study.

PURPOSE: Many atrial fibrillation (AF) patients use cardiovascular medications for indications other than AF. These medications can affect morbidity and mortality. We aim to investigate the characteristics of AF patients who use different medication classes and their clinical course. METHODS: We collected data from the prospective, multicenter registry, JoFib study. We identified classes of non-AF medications (medications not used for rate control, rhythm control, or anticoagulation), described demographic and clinical characteristics, and investigated AF-related outcomes according to these medication classes. RESULTS: From a total of 2020 patients, five classes of cardiovascular non-AF medications were identified, aspirin, P2Y12 inhibitors, ACE inhibitors/ARBs, statins, and diuretics. The most commonly used non-AF medications were diuretics and ACE inhibitors/ARBs (39.2%, and 39%, respectively). 51% of AF patients took more than one non-AF medication. Multivariable Cox regression analysis demonstrated that ACE inhibitor/ARB therapy independently reduced the risks of all-cause mortality and cardiovascular mortality (aHR 0.50, 95%CI 0.37-0.68; aHR 0.51, 95%CI 0.34-0.75, respectively) and that statin therapy reduced the risk of cardiovascular mortality (aHR 0.68, 95%CI 0.48-0.98) in AF patients. Multivariable logistic regression analysis demonstrated a protective effect of statin therapy against the secondary outcome, clinically relevant non-major bleeding (CRNMB) (adjusted OR 0.62 95%CI 0.42-0.94). CONCLUSION: Our findings suggest a protective effect of ACE inhibitors/ARBs against all-cause and cardiovascular mortality, statins against cardiovascular mortality, and CRNMB in patients with AF. Accordingly, these medications should be encouraged in patients with AF when indicated. Additionally, future research should explore whether these medications should be offered to AF patients more routinely. The study was registered with Clinicaltrials.gov (unique identifier number: NCT03917992, Registration date:14/4/2019).

Clinical recurrence and antiplatelet drug resistance among patients with lower limb ischemia.

There is a high prevalence rate of peripheral artery disease worldwide, with estimated cases exceeding 200 million. Most patients are under-diagnosed and under-treated, and there is a lack of knowledge regarding the best therapeutic regimen and therapy duration, which leads to many cases of recurrence, complications, and amputations. This study aims to explore clinical recurrence, which was defined as the worsening of chronic peripheral artery disease requiring hospital admission, and its relationship with antiplatelet drug resistance among patients with lower limb ischemia. This cohort study includes both retrospective and prospective recruitment of patients with chronic lower limb ischemia. Platelet aggregation tests were offered to the patients. Between February 2018 and November 2020, 147 patients were recruited from King Abdullah University Hospital and followed up for at least 1 year. Platelet aggregation tests were done for 93 patients who agreed to participate in this part of the study. The prevalence of chronic lower limb ischemia was higher in young male patients who are current smokers with co-morbid diseases such as hypertension, diabetes mellitus, and/or dyslipidemia. There was a significant association only of clinical recurrence with younger age (P = .011) and with low platelets count in severe stages of the disease (P = .047). No significant association was found in terms of laboratory resistance. The clinical recurrence rates of chronic lower limb ischemia were higher in younger patients and among those with low platelet counts in the severe stages of the disease. Despite the laboratory responsiveness to anti-platelet therapy, we observed significant clinical resistance and increased recurrence rates.

Development and Evaluation of the Efficacy and Toxicity of a New Hybrid Antimicrobial Peptide MY8.

BACKGROUND: Antibiotics have led to significant advancements in medicine. Unfortunately, they were faced with the emergence of pathogen resistance. According to the World Health Organization, antimicrobial resistance has been declared one of humanity's top ten global public health threats. The risk of those bacteria is not only from their being resistant to multi-antibiotics but also from their ability to form biofilms, which can be 1,000 times more resistant than planktonic bacteria. METHOD: This study used rational design to hybridize two antimicrobial peptides, aiming to enhance their efficacy and stability with reduced toxicity. RESULTS: The MY8 novel peptide was designed from the parent peptides BMAP-27 and CAMP 211-225. Some amino acid modifications were introduced to the hybrid peptide to improve its physicochemical properties guided by several software. Its antimicrobial activity has been studied against gram-negative and gram-positive strains, which showed broad-spectrum activity with MIC values against planktonic bacteria ranging from 0.125 to 25 µM. In contrast, 25-200 µM were needed to eradicate biofilms. Moreover, the MY8 peptide showed synergism with four conventional antibiotics., It also showed reduced toxicity against mammalian cells and a slight hemolysis tendency towards erythrocytes. CONCLUSION: The design of the MY8 peptide was successful, resulting in a novel, potent, broad-spectrum antimicrobial peptide with reduced toxicity and possible synergism with conventional antibiotics.

Design and in vitro assessment of chitosan nanocapsules for the pulmonary delivery of rifabutin.

Tuberculosis (TB) is a life-threatening disease and a main cause of death worldwide. It mainly affects the lungs, and it is attributed to the infection with Mycobacterium tuberculosis (MTB). Current treatments consist of the oral administration of combinations of antibiotics including rifabutin, in high doses and for long periods of time. These therapeutic regimens are associated with many side effects and high rates of drug resistance. To overcome these problems, this study aims at developing a nanosystem for the improved delivery of antibiotics, with potential application in pulmonary delivery. Chitosan-based nanomaterials are widely used in biomedical applications, due to their biodegradability and biocompatibility, as well as their potential antimicrobial effects and lack of toxicity. In addition, this polymer is particularly attractive for mucosal delivery due to its bioadhesive properties. Therefore, the structure of the proposed nanocarrier consists of a chitosan shell and a lipid core with a combination of different oils and surfactants to allow optimal association of the hydrophobic drug rifabutin. These nanocapsules were characterized in terms of size, polydispersity index, surface charge, morphology, encapsulation efficiency and biological stability. The release kinetics of the drug-loaded nanostructures was evaluated in simulated lung media. Moreover, in vitro studies in different cell models (A549 and Raw 264.7 cells) demonstrated the safety of the nanocapsules as well as their efficient internalization. An antimicrobial susceptibility test was performed to evaluate the efficacy of the rifabutin-loaded nanocapsules against Mycobacterium phlei. This study indicated complete inhibition for antibiotic concentrations within the expected susceptibility range of Mycobacterium (≤ 0.25-16 mg/L).

The Antimicrobial Effect Against Multi-drug Resistant Bacteria of the SK4 Peptide: A Novel Hybrid Peptide of Cecropin-A and BMAP-27.

BACKGROUND: Antibiotic-resistant is considered one of the critical health challenges in the management of infectious diseases. Resistant bacterial strains to different antibacterial agents have been spread worldwide. Anti-microbial peptides (AMPs), also called host defense peptides, have a broad spectrum of activity and targeting even to multi-drug resistant (MDR) bacteria, therefore, they have been extensively studied and developed as novel therapeutic antibacterial agents. OBJECTIVES: The study aims to design a novel SK4 hybrid peptide with improved characteristics compared with the BMAP-27 and Cecropin-A natural parents' peptides. METHODS: The bioinformatic analysis of the SK4 peptide compared with the parents BMAP-27 and Cecropin-A peptides was conducted and fully characterized using specialized software. The antimicrobial and antibiofilm activity of SK4 was tested, followed by a synergistic study with five conventional antibiotics (Levofloxacin, Rifampicin, Chloramphenicol, Doxycycline, and Ampicillin). Finally, the cytotoxicity against horse erythrocytes and mammalian cells was assessed. RESULTS: The SK4 peptide demonstrated broad-spectrum antimicrobial activity against both grampositive and gram-negative bacteria. The peptide also did not show any hemolytic activity even when used at concentrations ten folds higher than its MICs value. The SK4 peptide also showed a synergistic mode of action when combined with antibiotics, which resulted in a significant decrease in MIC values for both the peptide and the antibiotics. CONCLUSION: The SK4 peptide showed better activity, selectivity, and safety profile than the parent peptides, making it a novel potential treatment for MDR bacterial infections.

Hydrolysis kinetics of the prodrug myristyl nicotinate.

Myristyl nicotinate is a prodrug of nicotinic acid. In this research, the kinetics of hydrolysis for myristyl nicotinate was studied in an aqueous phosphate buffer solution within a 5-10 pH range and constant ionic strength at a high temperature which was 80 °C to perform accelerated hydrolysis experiments. The effect of temperature, ionic strength, buffer concentrations, and buffer type was studied. The degradation was monitored using a validated HPLC method. The kinetics of hydrolysis of myristyl nicotinate was also studied in skin and liver homogenates. The hydrolysis was found to follow pseudo-first-order kinetics. The rate constant was calculated from the slope of a linear plot of Ln transformation (Ln) of the remaining parent prodrug concentration versus time. The hydrolysis was found pH- dependent, and a pH rate profile was constructed. Moreover, the hydrolysis rate of the prodrug was found to be buffer species dependent. Carbonate buffer has the most catalytic effect over borate and phosphate buffers. The effect of temperature on the kinetics of hydrolysis of myristyl nicotinate in phosphate buffer at pH 9 at 343, 348, 353, and 358°K was studied. The hydrolysis was found to follow the Arrhenius equation. From the Arrhenius plot, the half-life at 25 °C, and the activation energy were calculated and were found to be 466.5 days and 24.57 kcal mol-1, respectively. The hydrolysis of the prodrug was faster in liver and skin homogenates than those in aqueous buffer solutions. The pseudo-first-order rate constants were found to be 0.012, 0.028 min-1 for myristyl nicotinate in the liver, and skin homogenates, respectively.

Hydroxypropyl Beta Cyclodextrin as a Potential Surface Modifier for Paclitaxel Nanocrystals.

Paclitaxel (PTX) is a hydrophobic chemotherapeutic agent cytotoxic against many serious cancers. This study aimed at designing novel PTX nanocrystals (PTX-NCs) coated with the biocompatible and biodegradable hydroxypropyl-beta-cyclodextrin (HPßCD) polymer with specific characteristics through the formation of a non-inclusion complex. Briefly, PTX-NCs were prepared by the anti-solvent method followed by homogenization. Then, the surface of the prepared PTX-NCs was modified using the HPßCD coat (HPßCD-PTX-NCs). The prepared nanocrystals, both coated and uncoated, were characterized in terms of size, polydispersity index, charge, morphology, and stability. Moreover, the nanocrystals were investigated using powder X-ray diffraction (PXRD), differential scanning calorimeter (DSC), and Fourier transform infrared spectroscopy (FTIR). As well, the in vitro release of PTX from the nanocrystals was determined under conditions similar to the IV route of administration. Furthermore, the tendency of the nanocrystals to induce hemolysis was investigated. Results indicated that the size was about 241.4 and 310.5 nm, the polydispersity index was 0.14 and 0.21, and the zeta potential was about - 22.6 and - 16.4 mV for PTX-NCs and HPßCD-PTX-NCs, respectively. Additionally, the PXRD, FTIR, and DSC profiles can be explained by the NCs' integrity and coat formation. The SEM images showed that both PTX-NCs and HPßCD-PTX-NCs have rod-like structures. Moreover, HPßCD-PTX-NCs had significantly superior in vitro release than both PTX-NCs and PTX. Interestingly, the hemolytic assay showed that HPßCD-PTX-NCs had a more efficient and safer profile than PTX-NCs. This study emphasized that HPßCD could be an interesting candidate for the surface modification of PTX-NCs providing superior properties such as release and safety profiles.

Development of Self-Emulsifying Drug Delivery Systems (SEDDSs) Displaying Enhanced Permeation of the Intestinal Mucus Following Sustained Release of Prototype Thiol-Based Mucolytic Agent Load.

In this study, mucoactive self-emulsifying drug delivery systems (SEDDSs) based on sustained release of N-acetylcysteine (NAC) were developed for providing effective intestinal mucopermeation. Polymeric ionic complexes of NAC were formed with polyethyleneimine (PEI), Eudragit E 100, and Eudragit RS 100 and loaded into a novel SEDDS. The SEDDSs exhibited a stable average size of 75 ± 12 nm (polydispersity index (PDI) < 0.3) and showed a rise in the zeta potential from −17.31 mV to −7.72 mV. On Caco-2 cells, SEDDSs at 1−3% were non-cytotoxic. An average of 91.8 ± 5.4% NAC was released from SEDDSs containing Eudragit E 100 (p ≤ 0.05) and Eudragit RS 100 (p ≤ 0.001) complexes at a significantly slower rate within 80 min, whereas the SEDDS containing PEI released NAC in a matter of seconds. Similarly, the SEDDS complexes revealed a time-dependent reduction in mucus dynamic viscosity of 52.6 ± 19.9%. Consequently, as compared with a blank SEDDS, mucodiffusion revealed about 2- and 1.8-fold significantly greater mucopermeation of SEDDSs anchoring Eudragit E 100−NAC and RS 100−NAC complexes (p ≤ 0.05), respectively. The mucoactive SEDDSs, which steadily released NAC while permeating the mucus, were linked to a significantly increased mucopermeation in vitro as a result of optimal mucolytic targeting.

Functional and Toxicological Evaluation of MAA-41: A Novel Rationally Designed Antimicrobial Peptide Using Hybridization and Modification Methods from LL-37 and BMAP-28.

BACKGROUND: Managing bacterial infections caused by multidrug-resistant (MDR) and biofilmforming bacteria is a global health concern. Therefore, enormous efforts were directed toward finding potential alternative antimicrobial agents, such as antimicrobial peptides (AMPs). AIM: We aimed to synthesize a novel modified hybrid peptide designed from natural parents' peptides with enhanced activity and reduced toxicity profile. METHODS: Rational design was used to hybridize the two antimicrobial peptides, in which the alpha-helical parts of BMAP-28 and LL-37 were combined. Then, several amino acid modifications were applied to generate a modified hybrid peptide named MAA-41. The physicochemical properties were checked using in silico methods. The MAA-41 was evaluated for its antimicrobial and anti-biofilm activities. Synergistic studies were performed with five conventional antibiotics. Finally, the cytotoxicity on mammalian cells and the hemolytic activity were assessed. RESULTS: The MAA-41 revealed a broad-spectrum activity against Gram-positive and Gram-negative bacteria, including standard and MDR bacterial strains. The concentration against planktonic cells ranged between 10 and 20 µM, with higher potency against Gram-negative bacteria. The MAA-41 displayed potent activity in eradicating biofilm-forming cells, and the MBECs were equal to the MIC values reported for planktonic cells. This new peptide exhibited reduced toxicity profiles against erythrocyte cells but not against Vero cells. Combining MAA-41 peptides with conventional antibiotics improved the antimicrobial activity of the combined agents. Either synergistic or additive effects were shown as a significant decrease in MIC to 0.25 µM. CONCLUSION: This study proposes the validity of a novel peptide (MAA-41) with enhanced antimicrobial activity and reduced toxicity, especially when used as conventional antibiotic combinations.

Development of Fluorescently Labeled Self-Emulsifying Drug Delivery Systems (SEDDS) for Prolonged Stability, In Vitro Sustained Release, and Cellular Uptake.

AIMS: In this study, four fluorescein hydrophobic ionic complexes were formed with the cationic polymers Eudragit RS, Eudragit RL, Eudragit E, and polyethyleneimine (PEI) to provide fluorescein sustained release, sustained cellular uptake, and stability. METHODS: Complexes were loaded in a self-emulsifying drug delivery system (SEDDS) composed of 40% Tween 80, 20% Kolliphor EL, 15% 2-n-Octyl-1-dodecanol, and 25% dipropylene glycol. SEDDS were investigated regarding their size, polydispersity index (PDI), zeta potential, and cytotoxicity. Fluorescein release from SEDDS was performed in phosphate buffer (pH 6.8 and pH 8), and the released fluorescein was evaluated for cellular uptake. Moreover, fluorescein from all of the SEDDS pre-concentrates was released at different time points to check its long-term stability over six months. RESULTS: The average fluorescein load in SEDDS was 0.045%. SEDDS showed an average droplet size of 24.9 ± 1.6 nm with PDI ≤ 0.3. SEDDS complexes diluted 1:100 increased the zeta potential from -7.3 mV to +3.7 mV and provided > 85% cell viability. A 92.27 ± 3.18% fluorescein exhibited a few seconds of immediate release when used as control or PEI complex in SEDDS. On the contrary, Eudragit-fluorescein complexes in SEDDS showed sustained release of 87.01 ± 5.22% fluorescein in ≤ 70 min with 22.19 ± 14.56% and 59.27 ± 16.57% released at 10 min in pH 6.8 and pH 8 release media, respectively. Comparatively, the medium at pH 6.8 maintained a significantly improved sustained fluorescein release (p ≤ 0.001). Furthermore, Eudragit RS/RL compared to Eudragit E, significantly exhibited a slower fluorescein release rate from SEDDS (p ≤ 0.01). The cellular uptake of the released fluorescein was 72.4 ± 8.2% for all SEDDS complexes after 3 h. Eudragit complexes compared to PEI complex in SEDDS significantly showed m ore sustained fluorescein cellular uptake at 1 h and 2 h (p ≤ 0.001). However, SEDDS complexes showed the longest fluorescein stability with PEI after six months, whereas fluorescein stability for SEDDS containing fluorescein as Eudragit complex and control showed 39.1% and 82.5% fluorescence decrease, respectively, after three months. CONCLUSION: In the developed SEDDS, the presence of hydrophobic ionic complexes can significantly promote longer stability and sustained cellular uptake of fluorescein while releasing in a sustained manner.

Paclitaxel Drug Delivery Systems: Focus on Nanocrystals' Surface Modifications.

Paclitaxel (PTX) is a chemotherapeutic agent that belongs to the taxane family and which was approved to treat various kinds of cancers including breast cancer, ovarian cancer, advanced non-small-cell lung cancer, and acquired immunodeficiency syndrome (AIDS)-related Kaposi's sarcoma. Several delivery systems for PTX have been developed to enhance its solubility and pharmacological properties involving liposomes, nanoparticles, microparticles, micelles, cosolvent methods, and the complexation with cyclodextrins and other materials that are summarized in this article. Specifically, this review discusses deeply the developed paclitaxel nanocrystal formulations. As PTX is a hydrophobic drug with inferior water solubility properties, which are improved a lot by nanocrystal formulation. Based on that, many studies employed nano-crystallization techniques not only to improve the oral delivery of PTX, but IV, intraperitoneal (IP), and local and intertumoral delivery systems were also developed. Additionally, superior and interesting properties of PTX NCs were achieved by performing additional modifications to the NCs, such as stabilization with surfactants and coating with polymers. This review summarizes these delivery systems by shedding light on their route of administration, the methods used in the preparation and modifications, the in vitro or in vivo models used, and the advantages obtained based on the developed formulations.

Positive COVID19-PCR patients as negative controls for COVID19 antibody tests.

COVID-19 serological antibody tests are recently needed for a relatively quick, affordable, and valuable assessment of the immunity toward COVID-19 infection. Furthermore, they can help with evaluating the sufficiency of the vaccination process and its longevity. There are limitations in the current approach of choosing the positive and negative control samples for the validation of those tests. Herein, we are proposing the use of blood samples from positive COVID-19 patients, at the beginning of the disease course, as negative control blood samples for the antibody tests. For more precision, both the negative and the positive control samples can be obtained from the same patients where the accuracy of the test will depend on its ability to detect the seroconversion, from negative to positive antibodies detection, within the same patient. Furthermore, when the validation of the test is accompanied by detecting/sequencing the viral genome in those COVID-19 patients, this can also aid in determining the accuracy of the test in detecting the immune response to specific viral variants. The latter notion is needed for the proper management of the COVID-19 crisis, new vaccines' manufacturing, and evaluating the vaccines' efficiencies. Finally, this approach could be requested/formulated by the regulatory agencies as part of the tests' validation and can be "in-house" obtained by health facilities before its clinical use.

Clavulanic Acid in the Scope of Helicobacter pylori Treatment: A Literature Review and Beyond.

BACKGROUND: Helicobacter pylori (H. pylori) infection is the most common cause of peptic ulcer disease and it can be associated with many complications, including malignancies. In clinical practice, some clinicians may use Clavulanic Acid (CA) in combination with amoxicillin or other beta-lactams as an addition to the standard treatment regimens. This practice may be done by habitual mistake, non-evidence based hypothetical assumptions, or by prescribing it as an alternative treatment. This review aims to expose the effect of CA against H. pylori infection and to review the possible mechanisms that may contribute to that effect. METHODS: A PubMed and Google Scholar literature search was obtained on both pre-clinical and clinical studies related to CA and H. pylori infection. RESULTS: Available clinical studies showed improvement in the eradication of H. pylori by about 10- 20% when CA was added to the treatment regimens. This effect for CA could be related to several mechanisms including inhibition of H. pylori growth by binding to Penicillin-Binding Proteins (PBPs), the transformation of H. pylori from the active filamentous form into coccoidal form, induction of the release of dopamine, modulation of immunological response towards H. pylori infection and its relationship with other microbiota. Randomized-controlled studies on patients with resistance to H. pylori are needed. Moreover, in vitro studies to evaluate the mechanisms by which CA may influence H. pylori are warranted. CONCLUSION: The presented literature suggests potential avenues for the use of CA in the management of peptic ulcer disease and H. pylori infection.

Evaluating Release Kinetics from Alginate Beads Coated with Polyelectrolyte Layers for Sustained Drug Delivery.

Current approaches in stem cell-based bone tissue engineering require a release of bioactive compounds over up to 2 weeks. This study presents a polyelectrolyte-layered system featuring sustained release of water-soluble drugs with decreased burst release. The bioactive compounds adenosine 5'-triphosphate (ATP), suramin, and A740003 (a less water-soluble purinergic receptor ligand) were incorporated into alginate hydrogel beads subsequently layered with different polyelectrolytes (chitosan, poly(allyl amine), alginate, or lignosulfonate). Drug release into aqueous medium was monitored over 14 days and evaluated using Korsmeyer-Peppas, Peppas-Sahlin, Weibull models, and a Langmuir-like "Two-Stage" model. Release kinetics strongly depended on both the drug and the polyelectrolyte system. For ATP, five alternating layers of poly(allyl amine) and alginate proved to be most effective in sustaining the release. Release of suramin could be prolonged best with lignosulfonate as polyanion. A740003 showed prolonged release even without layering. Applying polyelectrolyte layers significantly slowed down the burst release. Release curves could be best described with the Langmuir-like model.

The lockdown may contribute to the COVID-19 cases in developing countries, different perspectives on the curfew act, a report from Jordan.

COVID -19 has driven an unprecedented challenge to the economic, social, and health aspects of human life worldwide. The daily increasing numbers of human life loss encourage us, the healthcare and public health communities, to share best practices and lessons learned to mitigate the resurgence of this pandemic. On the other hand, the pandemic itself or alternatively our policies in dealing with it has led to a dramatic loss and disastrous effects on many aspects including the food and nutritional systems and the world of work. The economic and social disruption caused by the pandemic is devastating; tens of millions of people are at risk of falling into extreme poverty, while the number of undernourished people, currently estimated at nearly 690 million, could increase by up to 132 million by the end of the year. The number of workers who are losing their jobs and the number of bankruptcies for small businesses are increasing. This report aims to bring the attention of policymakers, especially in the developing countries including Jordan, to different perspectives about crucial law acts, the lockdown and the curfew act, that have tremendous effects on the economy and may soon become a main contributor to the increased level of COVID-19 transmission and the main source of the new COVID-19 cases. We hypothesize for a mathematical model based on the comparison between the number of sporadic new cases, number of new cases/family, and the average number of family members to anticipate the value and the sufficiency of the lockdown or the curfew acts on modulating the transmission and the number of new COVID-19 cases in societies.

The relationship between the Hammett acidity and the decomposition of cefotaxime sodium in the solid state.

It was of interest to correlate the solid-state acidity to the decomposition of a model drug namely cefotaxime sodium. Amorphous samples containing either an indicator probe (thymol blue) or a model drug (cefotaxime sodium) were prepared by freeze-drying. The prepared samples were characterized using XRPD and Karl Fischer titrimetry. The acidity in the solid state was measured using reflectance spectroscopy. The kinetics of hydrolysis of cefotaxime sodium was studied in solid state at 50 °C in the Hammett acidity range of 8.12-8.61 and at constant ionic strength. The kinetics of decomposition of cefotaxime sodium in solution was also studied in basic media in the pH range of 7.9-8.9 at 50 °C and at constant ionic strength. The degradation was monitored using a validated HPLC method. The hydrolysis was found to follow pseudo-first-order kinetics in solution and solid state. The results obtained showed that there is a good correlation between the Hammett acidity function and the base-catalyzed decomposition of cefotaxime sodium in the solid state. The Hammett acidity-rate profile for cefotaxime decomposition is similar to the pH-rate profile obtained in solution. The decomposition of cefotaxime sodium in the solid state was found to be sensitive to the ionic strength.