Innovative application of magnetically modified bovine horn as a natural keratin resource in the role of value-added organocatalyst

This study presents the conversion of bovine horn powder (BHP) as an available and low-cost waste material to a value-added highly recyclable catalyst. This green catalyst was prepared through the immobilization of BHP, as a natural keratin resource, on the magnetic Fe₃O₄ nanoparticles. The successful preparation of the catalyst was fully investigated using Fourier transform infrared, X-ray diffraction, and energy-dispersive X-ray spectroscopies as well as field emission scanning electron microscopy, vibrating sample magnetometry, and thermogravimetry. The catalytic efficiency of the prepared magnetic organocatalyst was evaluated in the synthesis of a large series of amide derivatives through the solvent-free transamidation reaction of different amides and amines with yields of 75–96%.

The conversion of bovine horn powder as an available and low-cost waste material to a value-added recyclable organocatalyst for transamidation reaction.     

Improved anticancer delivery of paclitaxel by albumin surface modification of PLGA nanoparticles

Background

Nanoparticles (NPs) play an important role in anticancer delivery systems. Surface modified NPs with hydrophilic polymers such as human serum albumin (HSA) have long half-life in the blood circulation system.

Methods

The method of modified nanoprecipitation was utilized for encapsulation of paclitaxel (PTX) in poly (lactic-co-glycolic acid) (PLGA). Para-maleimide benzoic hydrazide was conjugated to PLGA for the surface modifications of PLGA NPs, and then HSA was attached on the surface of prepared NPs by maleimide attachment to thiol groups (cysteines) of albumin. The application of HSA provides for the longer blood circulation of stealth NPs due to their escape from reticuloendothelial system (RES). Then the physicochemical properties of NPs like surface morphology, size, zeta potential, and in-vitro drug release were analyzed.

Results

The particle size of NPs ranged from 170 to 190 nm and increased about 20–30 nm after HSA conjugation. The zeta potential was about -6 mV and it decreased further after HSA conjugation. The HSA conjugation in prepared NPs was proved by Fourier transform infrared (FT-IR) spectroscopy, faster degradation of HSA in Differential scanning calorimetry (DSC) characterization, and other evidences such as the increasing in size and the decreasing in zeta potential. The PTX released in a biphasic mode for all colloidal suspensions. A sustained release profile for approximately 33 days was detected after a burst effect of the loaded drug. The in vitro cytotoxicity evaluation also indicated that the HSA NPs are more cytotoxic than plain NPs.

Conclusions

HSA decoration of PLGA NPs may be a suitable method for longer blood circulation of NPs.     

Prevalence of haptic feedback in robot-mediated surgery: a systematic review of literature

With the successful uptake and inclusion of robotic systems in minimally invasive surgery and with the increasing application of robotic surgery (RS) in numerous surgical specialities worldwide, there is now a need to develop and enhance the technology further. One such improvement is the implementation and amalgamation of haptic feedback technology into RS which will permit the operating surgeon on the console to receive haptic information on the type of tissue being operated on. The main advantage of using this is to allow the operating surgeon to feel and control the amount of force applied to different tissues during surgery thus minimising the risk of tissue damage due to both the direct and indirect effects of excessive tissue force or tension being applied during RS. We performed a two-rater systematic review to identify the latest developments and potential avenues of improving technology in the application and implementation of haptic feedback technology to the operating surgeon on the console during RS. This review provides a summary of technological enhancements in RS, considering different stages of work, from proof of concept to cadaver tissue testing, surgery in animals, and finally real implementation in surgical practice. We identify that at the time of this review, while there is a unanimous agreement regarding need for haptic and tactile feedback, there are no solutions or products available that address this need. There is a scope and need for new developments in haptic augmentation for robot-mediated surgery with the aim of improving patient care and robotic surgical technology further.     

Iron‐chelating effect of silymarin in patients with β‐thalassemia major: A crossover randomised control trial

This study aimed to determine the potential iron‐chelating effects of silymarin in patients with β‐thalassemia major receiving standard iron‐chelation therapy. We evaluated whether addition of silymarin to standard iron‐chelation therapy could improve iron burden markers and liver and cardiac function in these patients, via a placebo‐controlled, crossover clinical study. Silymarin (140 mg) or placebo were administered thrice daily to all patients (n = 82) for 12 weeks, and after a 2‐week washout period, patients were crossed over to the other groups. Silymarin efficacy was assessed by measuring serum iron level, ferritin level, total iron‐binding capacity and liver and cardiac function on magnetic resonance imaging. Silymarin treatment resulted in a negative change in the serum iron and ferritin levels and a positive change in the total iron‐binding capacity levels (treatment effect, p < .001, p = .06, and p = .05, respectively). Silymarin treatment led to positive changes in cardiac and liver function in both treatment sequences of study; however, this was not statistically significant. There was a negative change in liver iron concentration in both treatment sequences (treatment effect, p = .02). In conclusion, combined iron‐chelation and silymarin therapy was effective for improving the iron‐burden status in patients with β‐thalassemia major.     

Simulation of the θ′ Precipitation Process with Interfacial Anisotropy Effects in Al-Cu Alloys

The effects of anisotropic interfacial properties and heterogeneous elasticity on the growth and ripening of plate-like θ′-phase (Al₂Cu) in Al-1.69 at.% Cu alloy are studied. Multi-phase-field simulations are conducted and discussed in comparison with aging experiments. The precipitate/matrix interface is considered to be anisotropic in terms of its energy and mobility. We find that the additional incorporation of an anisotropic interfacial mobility in conjunction with the elastic anisotropy result in substantially larger aspect ratios of the precipitates closer to the experimental observations. The anisotropy of the interfacial energy shows comparably small effect on the precipitate’s aspect ratio but changes the interface’s shape at the rim. The effect of the chemo-mechanical coupling, i.e., the composition dependence of the elastic constants, is studied as well. We show that the inverse ripening phenomenon, recently evidenced for δ’ precipitates in Al-Li alloys (Park et al. Sci. Rep. 2019, 9, 3981), does not establish for the θ′ precipitates. This is because of the anisotropic stress fields built around the θ′ precipitates, stemming from the precipitate’s shape and the interaction among different variants of the θ′ precipitate, that disturb the chemo-mechanical effects. These results show that the chemo-mechanical effects on the precipitation ripening strongly depend on the degree of sphericity and elastic isotropy of the precipitate and matrix phases.     

Endoscopic Management of Cerebrospinal Fluid Rhinorrhea: The Charing Cross Experience

Objective To describe our experience of cerebrospinal fluid (CSF) rhinorrhea management.Design Retrospective.Setting Charing Cross Hospital, London, a tertiary referral center.Participants Fifty-four patients with CSF rhinorrhea managed from 2003 to 2011.Main outcome measures Surgical technique; Recurrence.Results Etiologically, 36 were spontaneous and 18 traumatic. Eight patients with spontaneous and two with traumatic leaks had previous failed repairs in other units. Success rates after first and second surgery were 93% and 100%, respectively. Mean follow-up was 21 months. Four patients, all of spontaneous etiology, had recurrences; three of these underwent successful second repair with three layered technique, and the fourth had complete cessation of the leak after gastric bypass surgery and subsequent weight reduction. Adaptation of anatomic three-layered repair since then averted any further failure in the following 7 years. Mean body mass index was 34.0 kg/m² in spontaneous and 27.8 kg/m² in traumatic cases (p < 0.05). Fifty percent of spontaneous leaks were from the cribriform plate, 22% sphenoid, 14% ethmoid, and 14% frontal sinus. In the traumatic CSF leak group: 33.3% were from the cribriform plate, 33.3% sphenoid, 22.2% ethmoid, and 11.1% frontal.Conclusion Endoscopic CSF fistula closure is a safe and effective operation. All sites of leak can be accessed endoscopically. We recommend the use of an anatomic three-layered closure in difficult cases.     

Systematic review of laryngeal reinnervation techniques

Objective

To systematically review outcomes of reinnervation techniques for the management of unilateral vocal fold paralysis (UVFP).

Data Sources

Medline and Cochrane databases for English-language studies published between 1966 and 2009 on the surgical management of UVFP.

Review Methods

Studies were excluded if they reported on bilateral vocal fold paralysis, used nonhuman subjects, or did not assess clinical outcomes. Outcomes of interest were visual analysis, acoustic analysis, perceptual analysis, and electromyography.

Results

Of 686 initial studies, 14 studies encompassing 329 patients were eligible for analysis. All studies had a case-series design. Of reported patients, 60.2 percent were men, with mean age of 51 years (range, 12-79 years). The most common reinnervation technique was ansa cervicalis-to-recurrent laryngeal nerve (RLN), which was most commonly performed after thyroidectomy (43.5%). Other techniques with reportable outcomes included primary RLN anastomosis, ansa-to-RLN combined with cricothyroid muscle-nerve-muscle pedicle, ansa-to-thyroarytenoid neural implantation, ansa-to-thyroarytenoid neuromuscular pedicle, and hypoglossal-to-RLN. Median postsurgical follow-up was 12 months, and mean time to first signs of reinnervation was 4.5 months (SD 2.9 months). Visual analysis of glottic gap showed the greatest mean improvement with ansa-to-RLN, from 2.25 (SD 0.886) to 0.75 (SD 0.886) mm (P < 0.01). Acoustic analysis showed greatest improvement with neural implantation, with a change in mean phonation time from seven (SD 1.22) to 16 (SD 5.52) seconds (P < 0.01). Perceptual analysis and electromyography demonstrated improvement in all studies.

Conclusion

Reinnervation is effective in the management of UVFP, although the specific method may be dictated by anatomical limitations. Prospective studies utilizing uniform and consistent outcome parameters are necessary.     

Implication of BRCA2 -26G>A 5' untranslated region polymorphism in susceptibility to sporadic breast cancer and its modulation by p53 codon 72 Arg>Pro polymorphism

Introduction  

The absence of mutation or promoter hypermethylation in the BRCA2 gene in the majority of breast cancer cases has indicated alternative ways of its involvement, deregulated expression being one possibility. We show how a polymorphism in the 5' untranslated region (UTR) of BRCA2 can serve as one such factor. Based on the hypothesis that variants of genes involved in the same pathway can influence the risk provided for breast cancer, the status of p53 codon 72 polymorphism was also investigated and a possible interaction between the polymorphisms was examined.     

Pharmacogenetics: A strategy for personalized medicine for autoimmune diseases

For many years, a considerable number of patients with autoimmune diseases (ADs) have suffered from a lack of drug response and drug‐related toxicity. Despite the emergence of new therapeutic options such as biological agents, patients continue to struggle with these problems. Unfortunately, new challenges, including the paradoxical effects of biological drugs, have complicated the situation. In recent decades, efforts have been made to predict drug response as well as drug‐related side effects. Thanks to the many advances in genetics, evaluation of markers to predict drug response/toxicity before the initiation of treatment may be an avenue toward personalizing treatments. Implementing pharmacogenetics and pharmacogenomics in the clinic could improve clinical care; however, obstacles remain to effective personalized medicine for ADs. The present study attempted to clarify the concept of pharmacogenetics/pharmacogenomics for ADs. After an overview on the pathogenesis of the most common types of treatments, this paper focuses on pharmacogenetic studies related to the selected ADs. Bridging the gap between pharmacogenetics and personalized medicine is also discussed. Moreover, the advantages, disadvantages and recommendations related to making personalized medicine practical for ADs have been addressed.