Effects of mixtures of herbicides on nutrient cycling and plant support considering current agriculture practices

The use of mixtures of pesticides and consecutive pesticide applications challenge current regulations aimed at protecting ecosystem health due to unpredictable effects of complex and dynamic mixtures. In this study, we tested the ecotoxicological effects of mixtures of herbicides, applied following a real application scheme of soybean production on soil health in a mesocosm experiment. The experiment included two sequential applications; first, glyphosate + dicamba + clethodim, and 30 days later, flumioxazin + metolachlor. Commercial products were used at the recommended doses and at two other concentrations: half and double the recommended dose. Soybean plants were exposed to the herbicide-contaminated soil from the time of sowing to the beginning of pod formation. Half of the plants were harvested at the vegetative stage and the remaining plants at the reproductive stage to evaluate endpoints related to plant support and nutrient cycling. Plant biomass was significantly affected during the vegetative stage at the recommended and double the recommended dose, with the effects being mixture-dose dependent. Lower total and arbuscular colonization of mycorrhizas were also observed in double the recommended dose, and intermediate results were observed for the recommended dose. Nodule mass and phosphorous concentration in plants decreased with increasing herbicide doses. By the end of the experiment, nodule mass and total mycorrhizal colonization were low in the plants treated with double the recommended dose of herbicides. However, both endpoints reached similar values to the control at lower herbicide doses. Plant height and phenology were only lower at double the recommended dose during the experiment. The use of non-standard endpoints evidenced that important soil functions were transiently or permanently affected, while the realistic application scheme accounted for the impact of the management practice currently used. Pesticide risk assessment should therefore, incorporate both issues to effectively protect the ecosystems.

Engineering a novel water-in-oil biocompatible microemulsion system for the ocular delivery of dexamethasone sodium phosphate in the treatment of acute uveitis

Due to their unique characteristics, microemulsions (ME) represent one of the most promising delivery systems which can conquer poor ocular drug bioavailability providing long residence time. Development of a ME system, relying on the use of a safe and non-irritant surfactant combination derived from sustainable resources and which can consolidate the small ME droplets, is the goal of this work. Herein, we report the design and characterization of a novel biocompatible, eco-friendly ME system loaded with the hydrophilic dexamethasone sodium phosphate (DEXP) using a novel surfactant mixture composed of D-α-tocopherol polyethylene glycol succinate (TPGS) and Plantacare® (coco-Glycosides). Capryol™ PGMC and double-distilled water were used as the respective oil and aqueous phases and the MEs were prepared by the water titration method, suitable for scaling up. Optimization of ME formulae was conducted by varying Plantacare® grades, TPGS to Plantacare® mass ratios and drug loading. The formulae were characterized in terms of physical appearance, droplet size (PS), size distribution (PDI), zeta potential (ZP), and stability. The optimized DEXP-loaded ME formula attained acceptable PS, PDI, and ZP values of 43 ± 5 nm, 0.35 ± 0.07, -12 ± 4 mV, respectively. TEM images confirmed a small PS ≤ 100 nm. The in vivo safety of ME was proved by the Draize test. The ME formula prompted excellent mucoadhesion and transcorneal permeation. The confocal studies showed deep penetration into the rabbits' corneas. In vivo studies using endotoxin-induced uveitis showed high ocular efficacy and a significant reduction in inflammatory cells, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The obtained results elect the novel engineered ME system as a promising tool for the ocular delivery of hydrophilic moieties in the management of various ophthalmic diseases.

Wound healing potential of silver nanoparticles embedded in optimized bio-inspired hybridized chitosan soft and dry hydrogel

Interactive wound dressings combining healing and antimicrobial potentials, besides ensuring patient compliance with a recognized wound care service gained considerable interest recently. Both hydrogel spray dried microparticles (HMP) and soft hydrogel (G) were prepared. The bio-inspired combinatory platform included natural bio-macromolecules namely: chitosan (CS) and collagen (COL) with wound healing enhancement and connective tissue building capabilities cross linked with the natural genipin (GN) to build a three dimensional structured matrix. The optimized plain hydrogel obtained by a box behnken design (BBD) program (G) scored maximum swelling and porosity. The network was hosted with green synthesized cefotaxime sodium (cef.Na) AgNPs reduced by the anabolic folic acid (FA). Both hydrogels exhibited good antimicrobial activity against gram +ve and -ve bacteria. The wound healing activity, evaluated in injured rats, showed >98 % and complete wound closure after two and three weeks respectively. Oxidative stress minimization was proved by the estimation of biochemical markers malondialdehyde (MDA) and superoxide dismutase (SOD) levels at the wound site.

Prevalence and determinants of chronic respiratory diseases in adults in rural Sudan

BACKGROUND: Chronic respiratory diseases (CRDs) greatly contribute to worldwide mortality. Despite new data emerging from Africa, prevalence estimates and determinants of CRDs in rural settings are limited. This study sought to extend the existing research conducted in urban Sudan by conducting a rural comparison.METHODS: Participants aged ≥18 years (n = 1,850), living in rural Gezira State completed pre-and post-bronchodilator spirometry and a questionnaire. Prevalence of respiratory symptoms and spirometric abnormalities were reported. Regression analyses were used to identify risk factors for CRDs.RESULTS: Prevalence of chronic airflow obstruction (CAO) was 4.1% overall and 5.5% in those aged ≥40 years. Reversibility was seen in 6.4%. Low forced vital capacity (FVC) was seen in 58.5%, and at least one respiratory symptom was present in 40.7% of the participants. CAO was more common among people aged 60-69 years (OR 2.07, 95% CI 1.13-3.82) and less common among highly educated participants (OR 0.50, 95% CI 0.27-0.93). Being underweight was associated with lower FVC (OR 3.07, 95% CI 2.24-4.20).CONCLUSIONS: A substantial burden of CRD exists among adults in rural Sudan. Investment in CRD prevention and management strategies is needed.

10-Hydroxy Decanoic Acid-Based Vesicles as a Novel Topical Delivery System: Would It Be a Better Platform Than Conventional Oleic Acid Ufasomes for Skin Cancer Treatment?

10-hydroxy decanoic acid (HDA), a naturally derived fatty acid, was used for the preparation of novel fatty acid vesicles for comparison with oleic acid (OA) ufasomes. The vesicles were loaded with magnolol (Mag), a potential natural drug for skin cancer. Different formulations were prepared using the thin film hydration method and were statistically evaluated according to a Box-Behnken design in terms of particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE). The ex vivo skin permeation and deposition were assessed for Mag skin delivery. In vivo, an assessment of the optimized formulae using 7,12-dimethylbenz[a]anthracene (DMBA)-induced skin cancer in mice was also conducted. The PS and ZP of the optimized OA vesicles were 358.9 ± 3.2 nm and -82.50 ± 7.13 mV compared to 191.9 ± 6.28 nm and -59.60 ± 3.07 mV for HDA vesicles, respectively. The EE was high (>78%) for both types of vesicles. Ex vivo permeation studies revealed enhanced Mag permeation from all optimized formulations compared to a drug suspension. Skin deposition demonstrated that HDA-based vesicles provided the highest drug retention. In vivo, studies confirmed the superiority of HDA-based formulations in attenuating DMBA-induced skin cancer during treatment and prophylactic studies.

Prevalence and determinants of chronic respiratory diseases in adults in Sudan

BACKGROUND: Chronic respiratory diseases (CRDs) are considered a significant cause of morbidity and mortality worldwide, although data from Africa are limited. This study aimed to determine the prevalence and determinants of CRDs in Khartoum, Sudan.METHODS: Data were collected from 516 participants aged ≥40 years, who had completed a questionnaire and undertook pre- and post-bronchodilator spirometry testing. Trained field workers administered the questionnaires and conducted spirometry. Survey-weighted prevalence of respiratory symptoms and spirometric abnormalities were estimated. Regression analysis models were used to identify risk factors for chronic lung diseases.RESULTS: Using the Third National Health and Nutrition Examination Survey, 1988-1994 (NHANES III) reference equations, the prevalence of chronic airflow obstruction (CAO) was 10%. The main risk factor was older age, 60-69 years (OR 3.16, 95% CI 1.20-8.31). Lower education, high body mass index and a history of TB were also identified as significant risk factors. The prevalence of a low forced vital capacity (FVC) using NHANES III was 62.7% (SE 2.2) and 11.3% (SE 1.4) using locally derived values.CONCLUSION: The prevalence of spirometric abnormality, mainly low FVC, was high, suggesting that CRD is of substantial public health importance in urban Sudan. Strategies for the prevention and control of these problems are needed.

Boosting hair growth through follicular delivery of Melatonin through lecithin-enhanced Pickering emulsion stabilized by chitosan-dextran nanoparticles in testosterone induced androgenic alopecia rat model

The strategy in this work was loading Melatonin (MEL), the powerful antioxidant photosensitive molecule, in novel Pickering emulsions (PEs) stabilized by chitosan-dextran sulphate nanoparticles (CS-DS NPs) and enhanced by lecithin, for treatment of androgenic alopecia (AGA). Biodegradable CS-DS NPs dispersion was prepared by polyelectrolyte complexation and optimized for PEs stabilization. PEs were characterized for droplet size, zeta potential, morphology, photostability and antioxidant activity. Ex-vivo permeation study through rat full thickness skin was conducted with optimized formula. Differential tape stripping trailed by cyanoacrylate skin surface biopsy was executed, for quantifying MEL in skin compartments and hair follicles. In-vivo evaluation of MEL PE hair growth activity was performed on testosterone induced AGA rat model. Visual inspection followed by anagen to telogen phase ratio (A/T) and histopathological examinations were conducted and compared with marketed 5% minoxidil spray "Rogaine ®". Data showed that PE improved MEL antioxidant activity and photostability. Ex-vivo results displayed MEL PE high follicular deposition. In-vivo study demonstrated that MEL PE treated testosterone induced AGA rat group, restored hair loss and produced maximum hair regeneration along with prolonged anagen phase amongst tested groups. The histopathological examination revealed that MEL PE prolonged anagen stage, increased follicular density and A/T ratio by 1.5-fold. The results suggested that lecithin-enhanced PE stabilized by CS-DS NPs was found to be an effective approach to enhance photostability, antioxidant activity and follicular delivery of MEL. Thus, MEL-loaded PE could be a promising competitor to commercially marketed Minoxidil for treatment of AGA.

ENPP4 and HOXA3 as potential leukaemia stem cell markers in acute myeloid leukaemia

INTRODUCTION

Acute myeloid leukaemia (AML) is a heterogeneous malignant disease with a high degree of treatment failure using chemotherapy. Leukaemia stem cells (LSCs) are CD34+CD38- early progenitors associated with poor prognosis in AML. A unique LSC phenotype that excludes rare normal haematopoietic stem cells (HSC) is still elusive. This study aimed to determine expression of selected potential LSC markers in normal and leukaemic myeloid cells and correlate prognosis in AML patients.

MATERIALS AND METHODS

Flow cytometry and RT-qPCR measured expressions of ALDH, IL3RA/CD123, CLEC12A/CLL-1/CD371, HOXA3 and ENPP4. Normal cord blood (n=3) and blood monocytes (n=5) represented HSC and mature cells, respectively. Myeloid leukaemia cell lines (THP-1, KG-1a, K562 and HL-60) represented progenitor cells at various stages of maturation. AML samples included chemo-resistant (n=8), early relapse (n=2) and late relapse (n=18).

RESULTS

Combining protein/gene expressions, CD34+CD38- was a feature of immature cells seen in cord blood, KG-1a, and K562 but not more mature cells (blood monocytes and HL-60). Normal cells expressed CD371 while mature cells (blood monocytes and HL-60) lacked CD123. ENPP4 was not expressed on normal cells while HOXA3 was expressed only on cord blood and THP-1. In AML, CD123, HOXA3, ENPP4 (but not CD371) were significantly increased in the CD34+CD38- fraction of chemo-resistant patients while ALDH was associated with chemo-resistance.

CONCLUSION

CD34+CD38- presented an immature phenotype and with ALDH were associated with poor prognosis. CD123, HOXA3 and ENPP4 further enriched the LSC population. ENPP4 has not been reported and has the advantage of not being expressed on HSC and normal monocytes.

A pan-cancer analysis reveals CHD1L as a prognostic and immunological biomarker in several human cancers

Introduction: Several recent studies pointed out that chromodomain-helicase-DNA-binding protein 1-like (CHD1L) is a putative oncogene in many human tumors. However, up to date, there is no pan-cancer analysis performed to study the different aspects of this gene expression and behavior in tumor tissues. Methods: Here, we applied several bioinformatics tools to make a comprehensive analysis for CHD1L. Firstly we assessed the expression of CHD1L in several types of human tumors and tried to correlate that with the stage and grade of the analyzed tumors. Following that, we performed a survival analysis to study the correlation between CHD1L upregulation in tumors and the clinical outcome. Additionally, we investigated the mutation forms, the correlation with several immune cell infiltration, and the potential molecular mechanisms of CHD1L in the tumor tissue. Result and discussion: The results demonstrated that CHD1L is a highly expressed gene across several types of tumors and that was correlated with a poor prognosis for most cancer patients. Moreover, it was found that CHD1L affects the tumor immune microenvironment by influencing the infiltration level of several immune cells. Collectively, the current study provides a comprehensive overview of the oncogenic roles of CHD1L where our results nominate CHD1L as a potential prognostic biomarker and target for antitumor therapy development.

Barriers and facilitators to pharmacy professionals’ specialist public health roles: a mixed methods UK-wide pharmaceutical public health evidence review

Introduction

Pharmaceutical Public Health (PPH) is defined as “the application of pharmaceutical knowledge, skills and resources to the science and art of preventing disease, prolonging life, promoting, protecting and improving health for all through organised efforts of society”.1 In the UK (and globally) pharmacy professionals (PPs) contribute to the delivery of local and national public/population health (PH) interventions.2,3 However, little is known to what extent PPs have specialist/advanced roles within PH practice.

Aim

The mixed methods review, commissioned by the UK Chief Pharmaceutical Officers in 2020, aimed to explore PPs’ specialist PH contributions including barriers and opportunities.

Methods

Databases available through PubMed were searched to retrieve articles published in English (2011- 2021) on seven topics including: emergency preparedness resilience and response (EPRR); integrating pharmacy to better support public health protection and improvement goals; public health skills and mitigating health inequalities. Two independent electronic surveys were developed, piloted and deployed for pharmacy and public health specialists via email cascade and social media. The surveys explored the extent to which PPs are involved in PH roles including the barriers and opportunities. Descriptive statistics summarised the data, and open-ended responses were themed. The NHS Health Research Authority tool identified this project did not require ethical approval as the surveys were service evaluation.

Results

Rapid Evidence reviews: Following assessment of 2,542 articles, 448 evidence statements were extracted from 135 relevant articles. They were predominantly from USA (39%) and UK (29%), with fewer high-quality reviews (17) or guidance (12), than moderate/low-quality reviews (42), single studies (33), or quantitative research (33). Common themes of PPs’ contributions included: surveillance and intelligence gathering; advocacy for their communities; signposting; delivery of health improvement and protection services; supporting people with long-term-conditions; and EPRR. Barriers identified included: limited public and professional awareness of pharmacy’s contribution to public health and under-resourced PH training. Pharmacy and PH professionals Surveys: There were UK-wide responses from 128 PPs and 37 PH specialists. Opportunities identified by PPs included: PH areas they directly contribute to (45%); qualifications, knowledge and skills (27%); strategic position in the community (19%), recent changing health landscape (4%). Barriers included lack of defined career pathway (20%); poor professional recognition (18%); limited resources (16%); lack of training and support (15%) and organisational and structural barriers (10%). PH specialists identified at least 12 areas from the Faculty of PH’s functions and standards, they believed additional benefits would be realised by PPs working directly within PH teams. Although only 40% PH specialists had PPs working within their teams, 83% stated that it would be beneficial or very beneficial to have PPs specialising in PH.

Discussion/Conclusion

Dedicated PPH training and system-wide leadership are required to fully realise population-level benefits. Low responses to the surveys present a study limitation, however, there was consensus from the themes emerging from both surveys and rapid evidence reviews findings. Pharmacy professionals make specialist contributions to PH despite barriers. Further investigation is required to identify how best to deploy advanced PPH resources. Future qualitative studies should be considered.

References

1. Walker, R. Pharmaceutical public health: the end of pharmaceutical care? The Pharmaceutical Journal 2000;264:340–1.

2. PHE (2017). Pharmacy: A Way Forward for Public Health https://www.gov.uk/government/publications/community-pharmacy-public-health-interventions (accessed 31 July 2021)

3. Thomson K, Hillier-Brown F, Walton N, Bilaj M, Bambra C, Todd A. The effects of community pharmacy-delivered public health interventions on population health and health inequalities: A review of reviews. Prev Med. 2019 Jul;124:98-109.

Towards more efficient inhalable chemotherapy: Fabrication of nanodiamonds-releasing microspheres

Nanodiamonds (NDs) are among the most promising chemotherapy vectors, however, they tend to aggregate upon storage, or when exposed to mild changes in pH or ionic strength. Therefore, fabrication of dried NDs with minimal change in particle size is highly desirable. In this study, we have developed a dried powder form of NDs with controlled particle size to be eligible for pulmonary delivery, after screening different drying protectants for their effect on NDs particle size and surface charge. Results showed that the nanospray-drying process in the presence of mannitol prevented the aggregation of NDs. Nanospray-dried NDs microparticles exhibited an optimal aerodynamic size for pulmonary delivery, and the in vitro aerosol deposition testing showed that NDs-embedded mannitol microspheres could deliver more than half of the emitted fraction to the lower stage of the Twin impinger device; indicating high pulmonary delivery potential. Upon loading NDs with doxorubicin (NDX) prior to spray dryng, they were able to deliver 2.6 times more drug to A549 lung cancer cell line compared to the free drug. Pharmacokinetics study in rats showed that inhaled NDX microparticles could efficiently limit the biodistribution of the drug to the lungs, and minimize the drug fraction reaching the systemic circulation. To conclude, nanospray-dried NDs microparticles present a promising vehicle for the pulmonary delivery of chemotherapeutic agents for treatment of lung cancer.

Ex vivo permeation parameters and skin deposition of melatonin-loaded microemulsion for treatment of alopecia

Background

Melatonin (MEL) is a powerful antioxidant molecule with anti-androgenic property. A microemulsion (ME) system loaded with MEL was designed for treatment of androgenic alopecia. Pseudo-ternary phase diagram was constructed, and ME formulae were developed using coconut oil, Tween 80 and PEG 400. In the present study, MEL ME was characterized and evaluated for droplet size, polydispersity index, zeta potential, morphology using TEM imaging. MEL ex vivo permeation study through rat skin followed by tape stripping for stratum corneum (SC) was performed for different ME formulae, to determine skin permeation parameters and detect SC-MEL deposition.

Results

Spherical and uniform particles of MEL-loaded microemulsion were formulated with high stability. In ex vivo permeation study, MEL ME exhibited low steady-state skin flux along with pronounced SC deposition which prevailed a controlled release manner.

Conclusion

The results suggested that MEL ME could be a promising candidate for further permeation and in vivo studies for androgenic alopecia treatment.

Chronic respiratory disease in adult outpatients in three African countries: a cross-sectional study

BACKGROUND: The greatest burden of chronic respiratory disease is in low- and middle-income countries, with recent population-based studies reporting substantial levels of obstructive and restrictive lung function.OBJECTIVE: To characterise the common chronic respiratory diseases encountered in hospital outpatient clinics in three African countries.METHODS This was a cross-sectional study of consecutive adult patients with chronic respiratory symptoms (>8 weeks) attending hospital outpatient departments in Ethiopia, Kenya and Sudan. Patients were assessed using a respiratory questionnaire, spirometry and chest radiography. The diagnoses of the reviewing clinicians were ascertained.RESULT: A total of 519 patients (209 Kenya, 170 Ethiopia, 140 Sudan) participated; the mean age was 45.2 years (SD 16.2); 53% were women, 83% had never smoked. Reviewing clinicians considered that 36% (95% CI 32-40) of patients had asthma, 25% (95% CI 21-29) had chronic bronchitis, 8% (95% CI 6-11) chronic obstructive pulmonary disease (COPD), 5% (95% CI 4-8) bronchiectasis and 4% (95% CI 3-6) post-TB lung disease. Spirometry consistent with COPD was present in 35% (95% CI 30-39). Restriction was evident in 38% (95% CI 33-43). There was evidence of sub-optimal diagnosis of asthma and COPD.CONCLUSION: In Ethiopia, Kenya and Sudan, asthma, COPD and chronic bronchitis account for the majority of diagnoses in non-TB patients with chronic respiratory symptoms. The suboptimal diagnosis of these conditions will require the widespread use of spirometry.

An "eat me" combinatory nano-formulation for systemic immunotherapy of solid tumors

Rational: Tumor immunogenic cell death (ICD), induced by certain chemotherapeutic drugs such as doxorubicin (Dox), is a form of apoptosis potentiating a protective immune response. One of the hallmarks of ICD is the translocation of calreticulin to the cell surface acting as an 'eat me' signal. This manuscript describes the development of a stable nucleic acid-lipid particles (SNALPs) formulation for the simultaneous delivery of ICD inducing drug (Dox) with small interfering RNA (siRNA) knocking down CD47 (siCD47), the dominant 'don't eat me' marker, for synergistic enhancement of ICD. Methods: SNALPs loaded with Dox or siCD47 either mono or combinatory platforms were prepared by ethanol injection method. The proposed systems were characterized for particle size, surface charge, entrapment efficiency and in vitro drug release. The ability of the SNALPs to preserve the siRNA integrity in presence of serum and RNAse were assessed over 48 h. The in vitro cellular uptake and gene silencing of the prepared SNALPs was assessed in CT26 cells. The immunological responses of the SNALPs were defined in vitro in terms of surface calreticulin expression and macrophage-mediated phagocytosis induction. In vivo therapeutic studies were performed in CT26 bearing mice where the therapeutic outcomes were expressed as tumor volume, expression of CD4 and CD8 as well as in vivo silencing. Results: The optimized SNALPs had a particle size 122 ±6 nm and an entrapment efficiency > 65% for both siRNA and Dox with improved serum stability. SNALPs were able to improve siRNA and Dox uptake in CT26 cells with enhanced cytotoxicity. siCD47 SNALPs were able to knockdown CD47 by approximately 70% with no interference from the presence of Dox. The siCD47 and Dox combination SNALPs were able to induce surface calreticulin expression leading to a synergistic effect on macrophage-mediated phagocytosis of treated cells. In a tumor challenge model, 50% of mice receiving siCD47 and Dox containing SNALPs were able to clear the tumor, while the remaining animals showed significantly lower tumor burden as compared to either monotreatment. Conclusion: Therefore, the combination of siCD47 and Dox in a particulate system showed potent anti-tumor activity which merits further investigation in future clinical studies.

Polypeptide and glycosaminoglycan polysaccharide as stabilizing polymers in nanocrystals for a safe ocular hypotensive effect

Improved ocular delivery of a poorly soluble anti-glaucoma drug, acetazolamide (ACZ), in a stable nanosuspension (NS) was the main target of the study. The anionic polypeptide, poly-γ-glutamic acid (PG) and the glycosaminoglycan, hyaluronic acid, were used to stabilize ACZ-NS prepared using the antisolvent precipitation (AS-PT) coupled with sonication technique. To endue in site biocompatibility with high tolerability, soya lecithin (SL) phospholipid has been also combined with polyvinyl alcohol (PVA). NS with uniform PS in the range 100-300 nm, high ζ > ±20 mV, and enhanced saturation solubility were produced. Targeting solvent removal with control on future particle growth, post-production processing of NS was done using spray drying. The carriers' composition and amount relative to ACZ-NS were optimized to allow for the production of a redispersible dry crystalline powder. Particles crystallinity was confirmed using X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) in liquid and spray dried NS. The modified Draize test proved the safety and tolerability following application to rabbit eyes accompanying an efficient ocular hypotensive activity using a steroid glaucoma model.

Bioinspired lipid-polysaccharide modified hybrid nanoparticles as a brain-targeted highly loaded carrier for a hydrophilic drug

Lipid-polysaccharide modified biohybrid nanoparticles (NPs) are eminent drug carriers for brain targeting, owing to their ability to prolong the circulation time and penetrate the blood brain barrier (BBB). Biohybrid NPs particular interest arises from their potential to mimic biological components. Herein, we prepared bioinspired lipid polymeric NPs, either naked or surface modified by a synthesized biocompatible dextran-cholic acid (DxC). The nanoprecipitation method was tailored to allow the assembly of the multicomponent NPs in a single step. Modulating the solvent/antisolvent system provided lipid polymer hybrid NPs in the size of 111.6 ± 11.4 nm size. The NPs encapsulated up to 92 ± 1.2% of a hydrophilic anti-Alzheimer drug, rivastigmine (Riv). The brain uptake, biodistribution and pharmacokinetics studies, proved the efficient fast penetration of the bioinspired surface modified NPs to the brain of healthy albino rats. The modified nanocarrier caused a 5.4 fold increase in brain targeting efficiency compared to the drug solution. Furthermore, the presence of DxC increased Riv's brain residence time up to 40 h. The achieved results suggest that the fabricated biohybrid delivery system was able to circumvent the BBB and is expected to minimize Riv systemic side effects.

Chitosan-coated nanodiamonds: Mucoadhesive platform for intravesical delivery of doxorubicin

Nanodiamonds (NDs) are an emerging delivery system with a massive surface area qualifying them for efficient loading with various drugs. However, NDs easily scavenge ions upon mixing with physiological media leading to rapid aggregation. Herein, chitosan was employed to endue steric stabilization to NDs and confer adhesiveness to the particles improving their retention in the urinary bladder. The effect of chitosan molecular weight and pH on the particle size and surface charge of chitosan-coated doxorubicin-loaded NDs (Chi-NDX) was investigated. Selected formula exhibited high drug loading efficiency (>90 %), small particle size (<150 nm), good colloidal stability, acid-favored drug release but limited stability in cell culture media. After further stabilization with TPP or dextran sulfate, selected TPP-treated formula displayed more potent cytotoxic effect compared with free doxorubicin and uncoated nanoparticles, and higher drug retention in ex vivo bovine bladder. Therefore, TPP-Chi-NDX is suggested as a promising system for mucosal anticancer delivery.

Nanodiamonds: Minuscule gems that ferry antineoplastic drugs to resistant tumors

Remarkable efforts are currently devoted to the area of nanodiamonds (NDs) research due to their superior properties viz: biocompatibility, minute size, inert core, and tunable surface chemistry. The use of NDs for the delivery of anticancer drugs has been at the forefront of NDs applications owing to their ability to increase chemosensitivity, sustain drug release, and minimize drug side effects. Accelerated steps towards the move of NDs from bench side to bedside have been recently witnessed. In this review, the effects of NDs production and purification techniques on NDs' final properties are discussed. Special concern is given to studies focusing on NDs use for anticancer drug delivery, stability enhancement and mediated targeted delivery. The aim of this review is to put the results of studies oriented towards NDs-mediated anticancer drug delivery side by side such that the reader can assess the potential use of NDs in clinics and follow up the upcoming results of clinical testing of NDs on animals and humans.

Construction and immunogenicity analysis of nanoparticulated conjugate of heat-stable enterotoxin (STa) of enterotoxigenic Escherichia coli

The ultimate goal of this research was to overcome the low immunogenicity of the biological macromolecule (heat stable enterotoxin STa) via its conjugation to biodegradable PLGA nanoparticles (NP). STa was first isolated from Enterotoxigenic Escherichia coli (ETEC), purified and identified using reported HPLC procedures. Optimized homogenous PLGA NP, prepared using the nanoprecipitation technique were used for conjugating STa using the carbodiimide synthesis. Covalent binding of STa to PLGA NP was confirmed via FTIR and ¹HNMR analysis. Safety and tolerability of the developed nanoparticulated STa-PLGA conjugate were confirmed by MTT assay on A549 lung cancer cells. After subcutaneous immunization, STA-PLGA NP conjugate induced a significant immune response in mice showing a strong binding and neutralizing antibody titer. The developed novel STa-PLGA NP conjugate is expected to provide promising protection against enterotoxigenic Escherichia coli (ETEC).

Passive targeting and lung tolerability of enoxaparin microspheres for a sustained antithrombotic activity in rats

Pulmonary bed can retain microparticles (MP) larger than their capillaries' diameter, hence we offer a promising way for lung passive targeting following intravenous (IV) administration. In this study, enoxaparin (Enox)-albumin microspheres (Enox-Alb MS) were, optimally, developed as lung targeted sustained release MP for IV use. Lung tolerability and targeting efficiency of Enox-Alb MS were tested, and the pharmacokinetic profile following IV administration to albino rats was constructed. In vivo studies confirmed high lung targeting efficiency of Enox-Alb MS with lack of potential tissue toxicity. The anticoagulant activity of the selected Alb MS was significantly sustained for up to 38 h compared to 5 h for the market product. Alb MS are promising delivery carriers for controlled and targeted delivery of Enox to the lungs for prophylaxis and treatment of pulmonary embolism.

Polymer-Based Novel Lung Targeted Delivery Systems

Background:

Due to its unique features, the respiratory tract had received great attention as a promising non-invasive route for drug administration to achieve both local and systemic effects. Efforts spent to tailor systems able to overcome the lung defence mechanisms and biological barriers are followed in this review. Aerodynamic diameter, morphology, lung deposition and drug release profiles are the main criteria describing the selected new smart lung targeted delivery systems.

Methods:

Novel systems such as nanoparticles, nano-embedded-in microparticles (NEM), small microparticles (MP), large porous particles (LPP), PulmospheresTM and polymeric micelles are used to passively target different areas in the respiratory tract. The most common preparation methods are outlined in the article. Special emphasis was given to the characteristics of the polymers used to fabricate the developed systems. Efforts made to prepare systems using chitosan (CS), alginate (alg), hyaluronic acid (HA), gelatin and albumin as examples of natural polymers and poly lactic-co-glycolic acid (PLGA) and poly(Ɛ-caprolactone) (PCL) as synthetic polymers were compiled.

Conclusion:

The continuous development and work in the area of lung targeting resulted in the development of engineered smart platforms with the capability to carry small drug molecules, proteins and genes to treat a variety of local and systemic diseases.

Computed tomography in diagnosis and staging of the retroperitoneal tumors

The main role of retroperitoneal tumor diagnosis is the imaging examination. Diagnostic imaging is essential for describing and predicting lesion integrity limits adjacent organs.

Methods. The results are based on a sample of 53 patients admitted in the Urology Clinic and investigated during the period 1 January 2005 - 31 December 2014. Results. CT scan for retroperitoneal tumor: vascular tumors are diagnosed in 100% of cases, while endocrine tumors and lymphomas values are between 50-66.67% in terms of a positive diagnosis. In 54.71% of cases studied was identified retroperitoneal tumor invasion into adjacent structures (29 patients), and for 12 cases (22.64%) CT scan was not conclusive enough. CT scan investigation to identify metastasis has statistical significance (p <0.01) according to the different types of retroperitoneal tumors, there were on average 35% for highlighting values of peritumoral lymph nodes and 13% for metastases. The relationship between retroperitoneal tumor size detected by CT (coefficient R =0.736) than those found intraoperative CT examination reveals that tends to underestimate the retroperitoneal tumor size.

Conclusions. Imaging diagnosis is mainframe of positive diagnosis for retroperitoneal tumors. CT scanning bring data not only on tumor location, but also about the nature of injuries (cystic or solid), presence or absence of necrosis, invasion of adjacent structures and abdominal metastases.

Tunable Biodegradable Nanocomposite Hydrogel for Improved Cisplatin Efficacy on HCT-116 Colorectal Cancer Cells and Decreased Toxicity in Rats

This work describes the development of a modified nanocomposite thermosensitive hydrogel for controlled cisplatin release and improved cytotoxicity with decreased side effects. The system was characterized in terms of physical properties, morphological architecture and in vitro cisplatin release. Cytotoxicity was tested against human colorectal carcinoma HCT-116. In vivo studies were conducted to evaluate the acute toxicity in terms of rats' survival rate and body weight loss. Nephro and hepatotoxicities were evaluated followed by histopathological alterations of various tissue organs. Nanocomposite thermosensitive hydrogel containing nanosized carrier conferred density and stiffness allowing a zero order drug release for 14 days. Enhanced cytotoxicity with 2-fold decrease in cisplatin IC50 was accomplished. A linear in vivo-in vitro correlation was proved for the system degradation. Higher animal survival rate and lower tissue toxicities proved the decreased toxicity of cisplatin nanocomposite compared to its solution.

Nanocomplexes of an insulinotropic drug: optimization, microparticle formation, and antidiabetic activity in rats

The aim of the present work was to test the ability of two non-diabetogenic carbohydrates to intranasally deliver the insulinotropic drug repaglinide (REP) for controlling blood glucose level. REP was loaded onto chitosan/alginate nanocomplexes (NCs) suitable for mucosal delivery and uptake. Improved stability and delivery characteristics were obtained by spray drying the selected NCs, yielding microparticles. A statistical experimental design was adopted to investigate the effects of the formulations’ variables on two critical responses: NC size and drug entrapment efficiency. Physicochemical characterizations of the network’s structures were done, and in vitro cytotoxicity and histopathological studies were conducted. The potential of the developed system to prolong the drug effect was tested on diabetic rats. The results showed that to attain particles suitable for nasal delivery, alginate should be used at its lowest level used in this study (0.6 mg/mL). A low level of chitosan (0.5 mg/mL) was needed when the drug was cation-loaded, while the high chitosan level (1 mg/mL) was more suitable when REP was anion-loaded. The best entrapment efficiency was achieved at a theoretical drug loading of 0.025 mg/mL. Discrete NCs could be rapidly recovered from the spray-dried microparticles. The cytotoxicity and histopathological studies indicated that such formulations were well tolerated. The antihyperglycemic activity of the nasally administered formulae was gradual but was significantly sustained over 24 hours, suggesting NC mucosal uptake. Nasal delivery of such dry powders achieved better glycemic control compared with the conventional oral tablets.

Malaysian private general practitioners' views and experiences on continuous professional development: A qualitative study

INTRODUCTION

Continuous professional development (CPD) is an important aspect of a medical practitioner's career. AIMing to be at par with other developed countries for high quality of professional practice, Malaysia is planning to implement compulsory CPD for the doctors.

AIM

The aim of the study was to explore the private general practitioners' (GPs) views, experiences and needs regarding CPD programme in the primary care service.

METHODS

This study used a qualitative methodology. Seven semi-structured interviews and three focus group discussions were conducted with private general practitioners from an urban area of Malaysia between January and December 2012. An interview topic guide was developed based on literature review and researchers' discussions and it was used to guide the interviews. All the interviews were audio-recorded, transcribed verbatim and the transcripts formed the data for analysis using the thematic approach.

RESULTS

GPs undertook a wide range of CPD programmes to keep up with medical advances, meet patients' expectations and improve financial rewards. Conferences, lectures and online recourses were the most mentioned methods of keeping updated. Some of the GPs felt that peer motivation and networking seem to motivate and facilitate participation in CPD programmes. However, they were wary of the validity and relevance of some CPD programmes, particularly those related to pharmaceutical industry. Although the participants agreed to the new mandatory CPD regulation, they voiced concerns on how it would be implemented and wished for a more effective method of monitoring.

CONCLUSIONS

Organised peer support and relevant CPD content may improve GP participation in CPD but adequate regulatory measure should be in place to monitor the CPD activities.

Nasal polysaccharides-glucose regulator microparticles: optimization, tolerability and antidiabetic activity in rats

The aim of the present study was to load the post-prandial glucose regulator, repaglinide (REP), on spray dried mucoadhesive microparticles (MPs) comprising anionic polysaccharides. The formulation parameters of the polysaccharides-REP spray dried powders (SDP) namely, polysaccharide type and drug to polymer (D/P) ratio, were optimized for % release after 5 min (R%5 min) and time required for 80% release (T80%). The suitability of the selected formulae for nasal application was evaluated by ex vivo mucoadhesion, in vitro cytocompatability and tolerability studies. A pharmacodynamic study in diabetic rats was conducted. Results showed that both polysaccharide type and amount greatly influenced the chosen responses. REP was highly incorporated in mucoadhesive MPs with proven safety on the rat nasal mucosa. The selected REP loaded powders exhibited a significant two to threefold increase in total decrease in blood glucose compared to the nasal and intravenous solutions.

Inhalable DNase I microparticles engineered with biologically active excipients

Highly viscous mucus poses a big challenge for the delivery of particulates carrying therapeutics to patients with cystic fibrosis. In this study, surface modifying DNase I loaded particles using different excipients to achieve better lung deposition, higher enzyme stability or better biological activity had been exploited. For the purpose, controlled release microparticles (MP) were prepared by co-spray drying DNase I with the polymer poly-lactic-co-glycolic acid (PLGA) and the biocompatible lipid surfactant 1,2-dipalmitoyl-Sn-phosphatidyl choline (DPPC) using various hydrophilic excipients. The effect of the included modifiers on the particle morphology, size, zeta potential as well as enzyme encapsulation efficiency, biological activity and release had been evaluated. Powder aerosolisation performance and particle phagocytosis by murine macrophages were also investigated. The results showed that more than 80% of enzyme activity was recovered after MP preparation and that selected surface modifiers greatly increased the enzyme encapsulation efficiency. The particle morphology was greatly modified altering in turn the powders inhalation indices where dextran, ovalbumin and chitosan hydrochloride increased considerably the respirable fraction compared to the normal hydrophilic carriers lactose and PVP. Despite of the improved aerosolisation caused by chitosan hydrochloride, yet retardation of chitosan coated particles in artificial mucus samples discouraged its application. On the other hand, dextran and polyanions enhanced DNase I effect in reducing cystic fibrosis mucus viscosity. DPPC proved good ability to reduce particles phagocytic uptake even in the presence of the selected adjuvants. The prepared MP systems were biocompatible with lung epithelial cells. To conclude, controlled release DNase I loaded PLGA-MP with high inhalation indices and enhanced mucolytic activity on CF sputum could be obtained by surface modifying the particles with PGA or dextran.

A rare case of arterial thrombosis in a 37-year-old male with Factor V Leiden mutation

BACKGROUND

The classic triad of symptoms seen in chronic mesenteric ischaemia is post-prandial pain, sitophobia (fear of food) and progressive weight loss. Patients with mesenteric ischaemia secondary to a prothrombotic state such as that rendered by the Factor V Leiden mutation, are substantially younger than the typical elderly patient in whom embolic disease triggered by atrial fibrillation is the main underlying cause.

METHOD

This is one such case report documenting arterial thrombosis in a 37-year-old male with a subsequently identified heterozygous Factor V Leiden mutation.

CONCLUSION

Factor V Leiden mutation is a contributing risk factor in cases of small bowel infarction.

Arginine at position 74 of the HLA-DR beta1 chain is associated with Graves' disease

Graves' disease (GD) is associated with HLA-DR3 (DRB1*03) in Caucasians, but the exact amino-acid sequence in the DR beta1 chain conferring susceptibility to GD is unknown. Therefore, the aim of our study was to identify the critical sequence among the HLA-DRB1 amino-acid residues occupying the peptide-binding pocket, which conferred susceptibility to GD. We sequenced the HLA-DRB1 locus in 208 Caucasian GD patients and 149 Caucasian controls. Sequence analysis showed an increased frequency of DR beta-Arg-74 in GD patients compared to controls (41.8 and 13.4%, respectively; P=2.3 x 10(-8), OR=4.6). Moreover, subset analyses showed that DR beta-Arg-74 was also significantly more frequent in the HLA-DR3 negative GD patients than in controls (7.6 vs 0.8%, P=0.02, OR=10.5), suggesting that the association with DR beta-Arg-74 is independent of the association with HLA-DR3. Structural modeling studies demonstrated that the change at position 74 from the neutral amino acids Ala or Gln to the positively charged amino-acid Arg significantly modifies the three-dimensional structure of the DR peptide-binding pocket. Our results suggested that structural heterogeneity of the DR beta-chain peptide-binding pocket P4 at residue 74 predispose some at risk individuals to GD.

[Indications of drug eluting stents]

The publication in 2001 of the first in-man results showing zero restenosis after sirolimus eluting stent implantation produced enormous excitement in the cardiological community. Today, both sirolimus and paclitaxel eluting stents have been shown in randomized trials to reduce restenosis as compared with conventional metallic stents. However, since drug eluting stents become available in Europe very little has changed in the every life of almost all interventional laboratories in Europe. The limitation currently impeding more widespread use of the new technology is nontechnical, nonmedical but economic. The high price of drug eluting stents relative to bare stents has been an obstacle to more widespread utilization of drug eluting stents.

Molecular dynamics simulation of a DNA containing a single strand break

Molecular dynamics simulations were performed for a dodecamer DNA containing a single strand break (SSB), which has been represented by a 3'-OH deoxyribose and 5'-OH phosphate in the middle of the strand. Molecular force field parameters of the 5'-OH phosphate region were determined from an ab initio calculation at the HF/6-31G level using the program package GAMESS. The DNA was placed in a periodic boundary box with water molecules and Na+ counter-ions to produce a neutralised system. After minimisation, the system was heated to 300 K, equilibrated and a production run at constant NTP was executed for 1 ns using AMBER 4.1. Snapshots of the SSB-containing DNA and a detailed analysis of the equilibrated average structure revealed surprisingly small conformational changes compared to normal DNA. However, dynamic properties calculated using the essential dynamics method showed some features that may be important for the recognition of this damage by repair enzymes.

Probing the general base catalysis in the first step of BamHI action by computer simulations

BamHI is a type II restriction endonuclease that catalyzes the scission of the phoshodiester bond in the GAGTCC cognate sequence in the presence of two divalent metal ions. The first step of the reaction is the preparation of water for nucleophilic attack by Glu-113, which has been proposed to abstract the proton from the attacking water molecule. Alternatively, the 3'-phosphate group to the susceptible phosphodiester bond has been suggested to play a role as the general base. The two hypotheses have been tested by computer simulations using the semiempirical protein dipoles Langevin dipoles (PDLD/S) method. Deprotonation of water by Glu-113 has been found to be less favorable by 5.7 kcal/mol than metal-catalyzed deprotonation with a concomitant proton transfer to bulk solvent. The preparation of the nucleophile by the 3'-phosphate group is less favorable by 12.3 kcal/mol. These results suggest that both the general base and the substrate-assisted mechanisms in the first step of BamHI action are less likely than the metal-catalyzed reaction. The metal ions in the active site of BamHI make the largest contributions to the reduction of the free energy of hydroxide ion formation. On the basis of these findings we propose that the first step of endonuclease catalysis does not require a general base; rather, the essential attacking nucleophile in BamHI catalytic action is stabilized by the metal ions.

Conformation and dynamics of normal and damaged DNA

The genetic information that determines the structure and function of living organisms is encoded in the nucleotide sequence of double-stranded DNA molecules. Despite an apparent structural homogeneity displayed by DNA, subtle local variations in structure and dynamics are functionally significant. Short sequences exhibit specificity for regulatory and catalytic proteins, which mediate fundamental processes necessary to the survival of the cell. However, the molecular basis for specific recognition is still incompletely understood. The "indirect readout" mechanism suggests that the relative propensity of DNA to undergo structural deformations induced by the protein contributes to specific protein-DNA recognition. Although the hypothesis was originally formulated to explain recognition of specific nucleic acid sequences by DNA-binding proteins, it may have particular application to the recognition of DNA damage, because damaged sites in DNA have different equilibrium structure and dynamics from undamaged DNA. In this work, we review the approaches that we took to investigate the questions of sequence- and damage-dependent structure and dynamics of DNA. We describe a statistical thermodynamic model that relates DNA configurational flexibility to sequence-specific protein-DNA binding. The model provides a theoretical basis for interpreting experimental measurements of DNA dynamics. We describe results from MCSCF calculations of the excited states of 2-aminopurine (2AP), which provide the theoretical basis for the intramolecular mechanism of quenching as well as the effect of environment on this process. We then describe our investigations of the effect of stacking, base pairing, and base dynamics on the fluorescence of 2-AP in model systems, which allow us to develop the relationships between steady-state and time-resolved fluorescence parameters on the one hand and local structural and dynamic properties of DNA on the other hand. Finally, we describe the application of the experimental approach to study the conformational heterogeneity of DNA abasic sites, a commonly occurring type of DNA damage. We demonstrate the power of the experimental algorithm to characterize the physical differences between undamaged and damaged DNA, as well as the effects of nucleic acid sequence in both of these contexts. Thus, the work described herein comprises a combination of theoretical and experimental approaches to the problem of sequence- and damage-dependent DNA deformation.