In Situ Synthesis and Self-Assembly of Peptide-PEG Conjugates: A Facile Method for the Construction of Fibrous Hydrogels

Peptide-based hydrogels have gained considerable attention as a compelling platform for various biomedical applications in recent years. Their attractiveness stems from their ability to seamlessly integrate diverse properties, such as biocompatibility, biodegradability, easily adjustable hydrophilicity/hydrophobicity, and other functionalities. However, a significant drawback is that most of the functional self-assembling peptides cannot form robust hydrogels suitable for biological applications. In this study, we present the synthesis of novel peptide-PEG conjugates and explore their comprehensive hydrogel properties. The hydrogel comprises double networks, with the first network formed through the self-assembly of peptides to create a β-sheet secondary structure. The second network is established through covalent bond formation via N-hydroxysuccinimide chemistry between peptides and a 4-arm PEG to form a covalently linked network. Importantly, our findings reveal that this hydrogel formation method can be applied to other peptides containing lysine-rich sequences. Upon encapsulation of the hydrogel with antimicrobial peptides, the hydrogel retained high bacterial killing efficiency while showing minimum cytotoxicity toward mammalian cells. We hope that this method opens new avenues for the development of a novel class of peptide-polymer hydrogel materials with enhanced performance in biomedical contexts, particularly in reducing the potential for infection in applications of tissue regeneration and drug delivery.

SiONx Coating Regulates Mesenchymal Stem Cell Antioxidant Capacity via Nuclear Erythroid Factor 2 Activity under Toxic Oxidative Stress Conditions

Healing in compromised and complicated bone defects is often prolonged and delayed due to the lack of bioactivity of the fixation device, secondary infections, and associated oxidative stress. Here, we propose amorphous silicon oxynitride (SiONx) as a coating for the fixation devices to improve both bioactivity and bacteriostatic activity and reduce oxidative stress. We aimed to study the effect of increasing the N/O ratio in the SiONx to fine-tune the cellular activity and the antioxidant effect via the NRF2 pathway under oxidative stress conditions. The in vitro studies involved using human mesenchymal stem cells (MSCs) to examine the effect of SiONx coatings on osteogenesis with and without toxic oxidative stress. Additionally, bacterial growth on SiONx surfaces was studied using methicillin-resistant Staphylococcus aureus (MRSA) colonies. NRF2 siRNA transfection was performed on the hMSCs (NRF2-KD) to study the antioxidant response to silicon ions. The SiONx implant surfaces showed a >4-fold decrease in bacterial growth vs. bare titanium as a control. Increasing the N/O ratio in the SiONx implants increased the alkaline phosphatase activity >1.5 times, and the other osteogenic markers (osteocalcin, RUNX2, and Osterix) were increased >2-fold under normal conditions. Increasing the N/O ratio in SiONx enhanced the protective effects and improved cell viability against toxic oxidative stress conditions. There was a significant increase in osteocalcin activity compared to the uncoated group, along with increased antioxidant activity under oxidative stress conditions. In NRF2-KD cells, there was a stunted effect on the upregulation of antioxidant markers by silicon ions, indicating a role for NRF2. In conclusion, the SiONx coatings studied here displayed bacteriostatic properties. These materials promoted osteogenic markers under toxic oxidative stress conditions while also enhancing antioxidant NRF2 activity. These results indicate the potential of SiONx coatings to induce in vivo bone regeneration in a challenging oxidative stress environment.

Association between electronic nicotine delivery systems use and risk of stroke: a meta-analysis of 1,024,401 participants

Introduction

To evaluate the relationship between electronic nicotine delivery systems (ENDS) use and the risk of stroke when compared to non-smokers.

Methods

A comprehensive search was conducted until June 15, 2023. We included observational studies that assessed association of current or former usage of ENDS with risk of stroke compared with non-smokers, reported the risk estimate as odds ratio (OR) or hazard ratio (HR) and were adjusted for possible confounders.

Results

6 studies with 1,024,401 participants were included in our analysis. ENDS use was associated with a significant increased risk of stroke (OR = 1.52; 95% CI: 1.17-1.97) compared with non-users. A non-significant association was found between former ENDS use and risk of stroke (OR = 1.03; 95% CI: 0.87-1.21).

Conclusions

The ENDS usage appears to be associated with a higher risk of stroke compared to non-use, whereas there was no association between former ENDS use and the risk of stroke.

Advanced Methodology for Rapid Isolation of Single Myofibers from Flexor Digitorum Brevis Muscle

Isolated individual myofibers are valuable experimental models that can be used in various conditions to understand skeletal muscle physiology and pathophysiology at the tissue and cellular level. This report details a time- and cost-effective method for isolation of single myofibers from the flexor digitorum brevis (FDB) muscle in both young and aged mice. The FDB muscle was chosen for its documented history in single myofiber experiments. By modifying published methods for FDB myofiber isolation, we have optimized the protocol by first separating FDB muscle into individual bundles before the digestion, followed by optimizing the subsequent digestion medium conditions to ensure reproducibility. Morphological and functional assessments demonstrate a high yield of isolated FDB myofibers with sarcolemma integrity achieved in a shorter time frame than previous published procedures. This method could be also adapted to other types of skeletal muscle. Additionally, this highly reproducible method can greatly reduce the number of animals needed to yield adequate numbers of myofibers for experiments. Thus, this advanced method for myofiber isolation has the potential to accelerate research in skeletal muscle physiology and screening potential therapeutics "ex vivo" for muscle diseases and regeneration.

Revolutionizing bone regeneration: advanced biomaterials for healing compromised bone defects

In this review, we explore the application of novel biomaterial-based therapies specifically targeted towards craniofacial bone defects. The repair and regeneration of critical sized bone defects in the craniofacial region requires the use of bioactive materials to stabilize and expedite the healing process. However, the existing clinical approaches face challenges in effectively treating complex craniofacial bone defects, including issues such as oxidative stress, inflammation, and soft tissue loss. Given that a significant portion of individuals affected by traumatic bone defects in the craniofacial area belong to the aging population, there is an urgent need for innovative biomaterials to address the declining rate of new bone formation associated with age-related changes in the skeletal system. This article emphasizes the importance of semiconductor industry-derived materials as a potential solution to combat oxidative stress and address the challenges associated with aging bone. Furthermore, we discuss various material and autologous treatment approaches, as well as in vitro and in vivo models used to investigate new therapeutic strategies in the context of craniofacial bone repair. By focusing on these aspects, we aim to shed light on the potential of advanced biomaterials to overcome the limitations of current treatments and pave the way for more effective and efficient therapeutic interventions for craniofacial bone defects.

Mass Spectrometry Approaches for Detection and Determination of Prostaglandins from Biological Samples

Accurate determination of prostaglandins (PGs) from biological samples is critical for understanding their biological functions and interactions during physiological and pathological processes. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a highly sensitive, accurate, and high-throughput approach for simultaneous detection of ultra-trace PGs from a single biological sample. Here we describe LC-MS/MS techniques and related sample pretreatment methods including both off-line and on-line SPE for the determination of PGs in biological samples.

Effect of the Renin-Angiotensin System Inhibitors on Inflammatory Markers: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To synthesize more conclusive evidence on the anti-inflammatory effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs).

METHODS

PubMed, Scopus, and Embase were searched from inception until March 1, 2021. We included randomized controlled trials (RCTs) that assessed the effect of ACEIs or ARBs, compared with placebo, on any of the following markers: C-reactive protein (CRP), interleukin 6 (IL-6), or tumor necrosis factor α (TNF-α). Mean changes in the levels of these markers were pooled as a weighted mean difference (WMD) with a 95% CI.

RESULTS

Thirty-two RCTs (n=3489 patients) were included in the final analysis. Overall pooled analysis suggested that ACEIs significantly reduced plasma levels of CRP (WMD, -0.54 [95% CI, -0.88 to -0.21]; P=.002; I²=96%), IL-6 (WMD, -0.84 [95% CI, -1.03 to -0.64]; P<.001; I²=0%), and TNF-α (WMD, -12.75 [95% CI, -17.20 to -8.29]; P<.001; I²=99%). Moreover, ARBs showed a significant reduction only in IL-6 (WMD, -1.34 [95% CI, -2.65 to -0.04]; P=.04; I²=85%) and did not significantly affect CRP (P=.15) or TNF-α (P=.97) levels. The lowering effect of ACEIs on CRP levels remained significant with enalapril (P=.006) and perindopril (P=.01) as well as with a treatment duration of less than 24 weeks (WMD, -0.67 [95% CI, -1.07 to -0.27]; P=.001; I²=94%) and in patients with coronary artery disease (WMD, -0.75 [95% CI, -1.17 to -0.33]; P<.001; I²=96%).

CONCLUSION

Based on this meta-analysis, ACEIs showed a beneficial lowering effect on CRP, IL-6, and TNF-α, whereas ARBs were effective as a class in reduction of IL-6 only.

Coenzyme Q10 Reduces Infarct Size in Animal Models of Myocardial Ischemia-Reperfusion Injury: A Meta-Analysis and Summary of Underlying Mechanisms

Objective

Effective interventions that might limit myocardial ischemia-reperfusion (I/R) injury are still lacking. Coenzyme Q₁₀ (CoQ₁₀) may exert cardioprotective actions that reduce myocardial I/R injury. We conducted this meta-analysis to assess the potential cardioprotective effect of CoQ₁₀ in animal models of myocardial I/R injury.

Methods

We searched PubMed and Embase databases from inception to February 2022 to identify animal studies that compared the effect of CoQ₁₀ with vehicle treatment or no treatment on myocardial infarct size in models of myocardial I/R injury. Means and standard deviations of the infarct size measurements were pooled as the weighted mean difference with 95% confidence interval (CI) using the random-effects model. Subgroup analyses were also conducted according to animals' species, models' type, and reperfusion time.

Results

Six animal studies (4 in vivo and 2 ex vivo) with 116 animals were included. Pooled analysis suggested that CoQ₁₀ significantly reduced myocardial infarct size by −11.36% (95% CI: −16.82, −5.90, p < 0.0001, I² = 94%) compared with the control group. The significance of the pooled effect estimate was maintained in rats, Hartley guinea pigs, and Yorkshire pigs. However, it became insignificant in the subgroup of rabbits −5.29% (95% CI: −27.83, 17.26; I² = 87%). Furthermore, CoQ₁₀ significantly reduced the myocardial infarct size regardless of model type (either in vivo or ex vivo) and reperfusion time (either ≤ 4 h or >4 h).

Conclusion

Coenzyme Q₁₀ significantly decreased myocardial infarct size by 11.36% compared with the control group in animal models of myocardial I/R injury. This beneficial action was retained regardless of model type and reperfusion time.

Surface Characteristics and In-Vitro Studies of TiO2 Coatings by Plasma Electrolytic Oxidation in Potassium-Phosphate Electrolyte

Plasma electrolytic oxidation (PEO) was used to produce titanium oxide (TiO2) coatings on Ti surface in potassium - phosphate electrolyte. The morphology, wettability, phase, and chemical compositions were studied as a function of processing parameters. The bioactivity of the coating was assessed by the ability to form biomimetic apatite in-vitro using cell culture medium. In-vitro studies using human mesenchymal stem cells were also conducted to evaluate cells' proliferation and viability of the treated Ti. The results revealed that the produced TiO2 coatings comprised pore features with the pore size increasing with applied current density and treatment duration due to high energy discharge channels at higher potential. The PEO treated Ti exhibited superhydrophilic characteristics with a contact angle <1°. The findings indicated that the large actual surface area produced by the PEO treatment and the presence of negatively charge P O 4 3 - are the key factors for the superhydrophilic behavior. The in-vitro studies revealed that the PEO treated groups had higher amount of biomimetic apatite formation compared to the as-polished Ti. The PEO treatment significantly enhanced the cells' adhesion and growth after 24 and 72 hrs compared to the untreated Ti. A significant difference in the bioactivity was not observed between anatase and rutile.

257 Comparing Practice Testing to Restudying in the Dissecting Room: An Experimental Study

Aim

Medical students employ many strategies for learning, most commonly restudying. However, evidence suggests that restudying is not as effective as other strategies, namely practice testing. Different studies have compared restudying to practice testing on a variety of subjects. Few studies have assessed the effect of practice testing in anatomy courses. To the best of the authors' knowledge, no studies have investigated practice testing in the dissecting room (DR). In this study, we aim to measure the effect of practice testing in a DR setting, as compared to restudying.

Method

Second-year medical students learning the cardiovascular system were included in the study. Two groups were randomly selected to participate in practice tests taken at the end of DR sessions. The other two groups were asked to restudy the material. At the end of the four-week course, all students took a 15 points multiple-choice exam on learned material. Authors of practice tests were blind to the final exam content and vice versa.

Results

One hundred eight students participated in the study. Fifty-three students were in the practice testing group, and 55 were in the restudying group. The practice testing group performed significantly better than the restudying group (p = .008), with a mean of 8.57 +/- 2.3 for the practice testing group and 7.27 +/- 2.6 for the restudying group.

Conclusions

Practice testing significantly improved retention of Anatomy. We recommend that practice testing is implemented regularly at the end of DR sessions to enhance the learning experience.

259 Effect of Telegram Videos on Anatomy Education Among 2nd Year Medical Students, University of Khartoum, 2021

Aim

COVID-19 had major effect on the health and medical education. In order to oblige with the social distancing and quarantine, universities shifted to online learning. This study aimed to assess the effect of online education on anatomy DR (dissection room) teaching by the use of telegram software.

Method

This was a cross-sectional, prospective interventional study, which was carried out among 2nd year medical students in University of Khartoum. Students undertook initial tests on the heart and anterior abdominal wall modules. Telegram videos, prepared by the author, on the anatomy of the heart and the anterior abdominal wall were distributed to students. Students took a second test after watching the videos. A total number of 41 students attended heart sessions and 40 students attended the anterior abdominal wall sessions were included.

Results

The pre-test mean score for the heart and abdomen modules were 4.56 ± 2.335 and 6.15 ± 2.94, respectively. The post-tests means were 9.98 ± 2.877 and 8.95 ± 3.14, respectively. 90% and 75% of the students were satisfied with these videos, respectively.

Conclusions

This study revealed that Telegram videos as a method of online teaching had a positive effect on the students' performance, which was evidenced by the significant improvement in student's scores after watching the videos. Additionally, most of the students were satisfied with the videos and give positive feedback.

Interfacial adhesion and surface bioactivity of anodized titanium modified with SiON and SiONP surface coatings

Titanium (Ti) surface modification via coating technologies (plasma spraying, electron-beam deposition) has been used to enhance bone-implant bonding by increasing the rate of hydroxyapatite (HA) formation, a property known as bioactivity. Regardless the enhancement in the surface activity, the high fabrication-temperature (> 600 °C) reduces coating-implant adhesion due to thermal expansion mismatch and reduces bioactivity due to increased crystallinity in the coating. Thus, amorphous surface coatings with strong Ti-substrate adhesion that can be fabricated at relatively low temperatures are crucially needed for enhanced osseointegration. Therefore, this study aimed to enhance the Ti surface bioactivity via strongly adherent bioactive thin film coatings deposited by low temperature (< 400 °C) plasma enhanced chemical vapor deposition technique on nanopore anodized-Ti (A-Ti) surface. Two groups of coating (silicon oxynitride (SiON) and silicon oxynitrophosphide (SiONP)) were deposited on anodized Ti and tested for interfacial adhesion and surface bioactivity. TEM and XPS were used to investigate the interfacial composition while interfacial adhesion was tested using nano-indentation tests which indicated a strong interfacial adhesion between the coatings and the A-Ti substrate. Surface bioactivity of the modified Ti was tested by comprehensive surface characterization (i.e., chemical composition, surface energy, morphology, and mechanical properties) and apatite formation on each surface. SiONP coating significantly enhanced the Ti surface bioactivity that presented the highest surface coverage of carbonated hydroxyapatite (HCA, ~ 40%) with a Ca/P ratio (~ 1.65) close to the stoichiometric hydroxyapatite (~ 1.67) found in bone biomineral. The HCA structure and morphology were confirmed by HR-TEM/SAED, XRD, FT-IR, and HR-SEM/EDX. MSCs in-vitro studies indicated preferable cells adhesion and proliferation on the modified surfaces without any cytotoxic effects. This study concluded that the improved surface bioactivity of Ti-SiON and Ti-SiONP coatings suggests their potential use as strongly adherent bioactive surface coatings for Ti implants.

Hepatocyte growth factor administration increases bone soluble phosphate and alters bone chemical structure in diabetic hypertensive rats

Hepatocyte growth factor (HGF) is a novel potential therapy for improving bone health in patients with type II diabetes and hypertension, but its effect on the bone molecular structure is not revealed yet. Here, X-ray absorption near edge structure (XANES) spectroscopy was used to explore the effects elicited by HGF on the bone chemical structure. This study assessed local calcium (Ca) and phosphorus (P) coordination of diabetic hypertensive rat bones, each with and without HGF treatment. Results revealed that HGF has significant effects on Ca and P coordination chemistry as confirmed by presence of more soluble phosphates in the HGT-treated groups. Data indicated that treated bones have a poorly developed phosphate structure as evidenced by drastic drop in post-edge shoulder in P L2,3-edge compared to diabetic hypertensive and diabetic control bone. Presence of soluble Ca and P, products of bone resorption, with HGF treatment suggests unbalanced bone resorption and formation.

Effect of the renin angiotensin system inhibitors on inflammatory markers: a systematic review and meta-analysis of 32 randomized controlled trials

Background

Inflammation plays a critical role in the etiology of cardiovascular disease (CVD). The renin-angiotensin system inhibitors including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) have been shown to be effective in reducing elevated blood pressure. However, the information on their potential effect on inflammatory markers including C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) is still lacking.

Purpose

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to synthesize evidence about effect of ACEIs and ARBs on selected inflammatory markers.

Methods

PubMed, Scopus, and Embase were searched from inception until February 15, 2021. We included RCTs that assessed the effect of ACEIs or ARBs, compared with placebo, on any of the following markers: CRP, IL-6, or TNF-α. Mean changes in the relevant markers levels were pooled as a standardized mean difference (SMD) with a 95% confidence interval (CI) under the random-effects model. Heterogeneity was assessed using I2 and χ2 tests.

Results

Thirty-two RCTs (n=3,403 patients) were included in the analysis. Overall pooled analysis suggested that ACEIs significantly reduced plasma levels of CRP (SMD: −1.08 [95% CI: −1.57 to −0.59]; I2: 95%), IL-6 (SMD: −0.75 [95% CI: −1.41 to −0.09]; I2: 81%), and TNF-α (SMD: −1.77 [95% CI: −2.82 to −0.73]; I2: 95%). This lowering effect remained statistically significant by perindopril in terms of all relevant markers, by quinapril and ramipril in terms of IL-6 and by enalapril in terms of TNF-α. As for the ARBs as a class, they showed a statistically significant reduction only in terms of CRP (SMD: −0.14 [95% CI: −0.28 to −0.01]; I2: 0%) and did not significantly affect any of the other markers. Moreover, the ARBs individual drugs did not show any significant effect on any of the relevant markers except for valsartan that significantly reduced plasma levels of IL-6 (SMD: −0.42 [95% CI: −0.80 to −0.04]; I2: 0%).

Conclusions

Based on the results of this meta-analysis, ACEIs showed a beneficial lowering effect on CRP, IL-6, and TNF-α, while ARBs were effective as a class only in terms of CRP reduction. Further larger RCTs are warranted to confirm these results particularly in case of individual drugs and to assess the significance of these reductions in terms of CVD prevention.

Funding Acknowledgement

Type of funding sources: None.

Association of statin use in older people primary prevention group with risk of cardiovascular events and mortality: a systematic review and meta-analysis of observational studies

Background

Current evidence from randomized controlled trials on statins for primary prevention of cardiovascular disease (CVD) in older people, especially those aged &gt;75 years, is still lacking.

Purpose

We conducted a systematic review and meta-analysis of observational studies to extend the current evidence about association of statin use in older people primary prevention group with risk of CVD and mortality.

Methods

PubMed, Scopus, and Embase were searched from inception until March 18, 2021. We included observational studies (cohort or nested case-control) that compared statin use vs non-use for primary prevention of CVD in older people aged ≥65 years; provided that each of them reported the risk estimate on at least one of the following primary outcomes: all cause-mortality, CVD death, myocardial infarction (MI), and stroke. Risk estimates of each relevant outcome were pooled as a hazard ratio (HR) with a 95% confidence interval (CI) using the random-effects meta-analysis model.

Results

Ten observational studies (9 cohort and one case-control study; n=872,845) fulfilled our criteria. The overall combined estimate suggested that statin therapy was associated with a significantly lower risk of all-cause mortality (HR: 0.86 [95% CI: 0.79 to 0.93]), CVD death (HR: 0.80 [95% CI: 0.78 to 0.81]), and stroke (HR: 0.85 [95% CI: 0.76 to 0.94]) and a non-significant association with risk of MI (HR: 0.74 [95% CI: 0.53 to 1.02]). The beneficial association of statins with the risk of all-cause mortality remained significant even at higher ages (&gt;75 years old; HR: 0.88 [95% CI: 0.81 to 0.96]) and in both men (HR: 0.75 [95% CI: 0.74 to 0.76]) and women (HR: 0.85 [95% CI: 0.72 to 0.99]). However, this association with the risk of all-cause mortality remained significant only in those with DM (HR: 0.82 [95% CI: 0.68 to 0.98]) but not in those without DM.

Conclusions

Statin therapy in older people (aged ≥65 years) without CVD was associated with a 14%, 20% and 15% lower risk of all-cause mortality, CVD death and stroke, respectively. The beneficial association with the risk of all-cause mortality remained significant even at higher ages (&gt;75 years old), in both men and women, and in individuals with DM, but not in those without DM. These observational findings support the need for trials to test benefits of statins in those above 75 years of age.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Results of the meta-analysis

Bioprinted nanocomposite hydrogels: A proposed approach to functional restoration of skeletal muscle and vascular tissue following volumetric muscle loss

Musculoskeletal conditions are the highest contributor to global disability, accounting for 16% of all ages lived with disability. Volumetric muscle loss (VML) is classified as significant damage to skeletal muscle compartments and motor units, leading to significant tissue loss, functional deficits, and long-term disability. In this review, the current tissue engineering approaches in terms of fabrication techniques, materials, cell sources, and growth factors for enhanced angiogenesis and neuromuscular junction (NMJ) in VML repair, are discussed. Review of results recently published in the literature suggested that bioprinted nanocomposite hydrogels (NC gels) seeded with adult muscle progenitor cells that promote secretion of endogenous vascular growth factors have potential applications in promoting skeletal muscle regeneration, revascularization, and NMJ repair (Figure 1). Despite recent advancements, future research is needed on NC gels and the complex processes underlying vascular infiltration and NMJ repair in VML injuries.

Ionic Silicon Protects Oxidative Damage and Promotes Skeletal Muscle Cell Regeneration

Volumetric muscle loss injuries overwhelm the endogenous regenerative capacity of skeletal muscle, and the associated oxidative damage can delay regeneration and prolong recovery. This study aimed to investigate the effect of silicon-ions on C2C12 skeletal muscle cells under normal and excessive oxidative stress conditions to gain insights into its role on myogenesis during the early stages of muscle regeneration. In vitro studies indicated that 0.1 mM Si-ions into cell culture media significantly increased cell viability, proliferation, migration, and myotube formation compared to control. Additionally, MyoG, MyoD, Neurturin, and GABA expression were significantly increased with addition of 0.1, 0.5, and 1.0 mM of Si-ion for 1 and 5 days of C2C12 myoblast differentiation. Furthermore, 0.1-2.0 mM Si-ions attenuated the toxic effects of H2O2 within 24 h resulting in increased cell viability and differentiation. Addition of 1.0 mM of Si-ions significantly aid cell recovery and protected from the toxic effect of 0.4 mM H2O2 on cell migration. These results suggest that ionic silicon may have a potential effect in unfavorable situations where reactive oxygen species is predominant affecting cell viability, proliferation, migration, and differentiation. Furthermore, this study provides a guide for designing Si-containing biomaterials with desirable Si-ion release for skeletal muscle regeneration.

Novel 3D-printed methacrylated chitosan-laponite nanosilicate composite scaffolds enhance cell growth and biomineral formation in MC3T3 pre-osteoblasts

This study compared the effect of gelatin- and chitosan-based scaffolds on osteoblast biomineralization. These scaffolds have been modified using methacrylate and laponite nanosilicates to improve their mechanical strength and support osteoblast function. Scaffold materials were prepared to have the same compressive strength (14-15 MPa) such that differences in cell response would be isolated to differences in biopolymer chemistry. The materials were tested for rheological properties to optimize the bio-ink for successful 3D printing using a robocast-assisted deposition system. Osteoblasts were cultured on the surface of 3D-printed methacrylated chitosan-laponite (MAC-Lp), methacrylated gelatin-laponite (MAG-Lp), MAC, and MAG scaffolds. MAC-Lp scaffolds showed increased cell viability, cell growth, and biomineral formation as compared to MAG-Lp scaffolds. FTIR results showed the presence of higher biomineral phosphate and extracellular matrix (ECM) collagen-like amide formation on MAC-Lp scaffolds as compared to MAG-Lp scaffolds. MAC-Lp scaffolds showed increased density of ECM-like tissue from SEM analysis, stained mineral nodules from Alizarin staining, and the existence of Ca─P species evident by X-ray absorbance near edge structure analysis. In conclusion, MAC-Lp scaffolds enhanced osteoblast growth and biomineral formation as compared to MAG-Lp scaffolds.

Effect of Ezetimibe Monotherapy on Plasma Lipoprotein(a) Concentrations in Patients with Primary Hypercholesterolemia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

Ezetimibe reduces plasma low-density lipoprotein cholesterol (LDL-C) levels by up to 20%. However, its effect on plasma lipoprotein(a) [Lp(a)] concentrations in patients with primary hypercholesterolemia has not been defined.

OBJECTIVE

Therefore, we performed a systematic review and meta-analysis to assess this effect based on the available randomized controlled trials (RCTs).

METHODS

We searched the PubMed and SCOPUS databases from inception until 28 February 2017 to identify RCTs that investigated the effect of ezetimibe monotherapy on plasma Lp(a) concentrations in patients with primary hypercholesterolemia. We pooled mean percentage changes in plasma Lp(a) concentrations as a mean difference (MD) with a 95% confidence interval (CI).

RESULTS

Seven RCTs with 2337 patients met the selection criteria and were included in the analysis. Overall pooled analysis suggested that ezetimibe 10 mg significantly reduced plasma Lp(a) concentrations in patients with primary hypercholesterolemia by - 7.06% (95% CI - 11.95 to - 2.18; p = 0.005) compared with placebo. No significant heterogeneity was observed (χ² = 5.34; p = 0.5). Excluding one study from the analysis resulted in insignificant differences between the two groups (p = 0.2). Meta-regression did not find a significant association between the mean percentage changes in Lp(a) and other potential moderator variables, which included the mean percentage changes of LDL-C concentrations (p = 0.06) and baseline Lp(a) mean values (p = 0.46).

CONCLUSIONS

Ezetimibe monotherapy (10 mg/day) showed a small (7.06%) but statistically significant reduction in the plasma levels of Lp(a) in patients with primary hypercholesterolemia. According to current literature, this magnitude of reduction seems to have no clinical relevance. However, further studies are warranted to clarify the mechanism mediating this effect of ezetimibe and to investigate its efficacy in combination with other drugs that have shown promise in lowering Lp(a) levels.

Long-term outcome of JJ stent insertion for primary obstructive megaureter in children

BACKGROUND/AIM

Endoscopic stenting is an accepted treatment option for children with symptomatic or progressive primary obstructive megaureter (PROM). Here, long-term outcomes with endoscopic stenting are reviewed.

METHODS

Patients with PROM treated surgically over a 12-year period were identified using a prospectively maintained departmental database. Data were analysed using Microsoft Excel 2013 and unpaired t-tests through GraphPad Software QuickCalcs.

RESULTS

Fifty-seven patients with PROM were surgically managed in the study centre from 2005 to 2017. Twenty-nine of fifty-seven patients had the stent as the primary procedure, whereas the remainder had ureterostomy, re-implantation or nephrectomy. Six patients had bilateral PROM, giving a total of 35 renal units that were fully analysed. There was 7:1 male predominance, and 20 of 29 patients (69%) were diagnosed antenatally. The median age at stent insertion was 8 months (40 days-10 years); the median prestent ureteric diameter was 19 mm and the median pre-operative function on MAG3 was 44%. Cystoscopic stent insertion was feasible in all patients. The stent was left for a median of 183 days. In 9 of 35 (26%) renal units, the JJ stent was a successful sole long-term treatment, with median follow-up of 5 years and 8 months. The success rate was not different in children aged <1 year (8/22; 36%) in comparison to children aged >1 year (1/13; 8%), P = 0.1. The remaining 26 renal units required further surgical intervention: ureteric re-implantation in 25 and nephrectomy in one. Indications for further surgery were stent complications in 11 renal units and stent failure in 15 (Table 1). Complications related to the stent were noted in 14 renal units (41%), half being stent migration. Other complications included UTIs, stent encrustation and recurrent haematuria. There was no identifiable prestent parameter, whether clinical or radiological, that could predict which patients were likely to be successfully managed solely by stent insertion. Stent insertion was never successful as a definitive procedure when the distal ureteric diameter was >12 mm on the ultrasound after stent removal.

DISCUSSION

Success rates with primary stenting as a sole treatment for PROM was 26%, which is less than that seen in other reports (50-66%). This may be attributed to the long-term follow-up in this study, together with the strict criteria for success.

CONCLUSION

In the authors' experience, cystoscopically inserted JJ stents are of limited success as the sole treatment for PROM. In infants aged <1 year, stent insertion remains a reasonable temporising measure until the infant is old enough for a definitive procedure.

Thyroid Cancer Profile: Experience of Liga Contra El Cancer Honduras 2014-2017

Background: In recent years we have observed increase in thyroid carcinoma TC incidence at cancer centers in Honduras. TC is linked to exposure to ionizing radiation. Other risks factors described in literature are obesity, diabetes, nitrites and nitrates in diet and alcohol. DNA rupture, activation of oncogenes, and secretion of inflammatory cytokines are initial events that derive in mutations and malignant transformation. Papillar, follicular and undifferentiated carcinoma are the histologic types. Little is known about TC in the population, and there are no efficient models for prevention and early detection to date. Aim: Describe the clinical and demographic profile of patients diagnosed with TC at La Liga Contra el Cancer Hospital LCC from 2014-2017, with intention to identify patterns that allow approaches to pathogenicity and prevention. Methods: We revised 103 medical records of all TC patients treated at LCC from Jan 2014-December 2017 to obtain information about geographical origin, age, gender, localization of tumor, identifiable risk factor, treatment and outcomes. A digital database was in Microsoft Office Excel and exported to SPSS. Patient information was deidentified before data extraction. Results: 91.3% patients were female. Median age 49.3 ± 15.6 years (95% CI, 46.05-52.2). Patients went from 11/18 departments (political division), 74% gathered in the northern zone of the country. Histology type: papillary 91.3%; follicular 4.9%, anaplasic 1.9%; medullary 1.0%. Papillary TC, 37% of patients were in fifth decade, 22.9% in patients 31-40 yo, 17.3% in patients 41-50 yo, 9.7% were under 30s. Clinical stage at diagnosis: I I (n = 24) 23.6%, II (n = 13), 12.6%. III (n = 18), 17.5%. IV (n = 14), 15.6%; not suitable for staging 5.8%, the rest had no precise information for staging. 12.6% of patients reported family history of cancer (any type), 33% of patients reported comorbidities. Conclusion: Thyroid carcinoma has increased in the last years, from our experience we can identify that women are mostly affected, with papillary type being the most common. Ages affected are between 41-60 years old. One third of patients had comorbidities as hypothyroidism, diabetes and arterial hypertension. 74% reside in the northern zone of Honduras, there is need to elucidate if it is a matter of geographical location of the LCC. No emerging risk factors were identified in this cohort. More research is needed to profile thyroid carcinoma in our region.

The optimal time of day for statin administration: a review of current evidence

PURPOSE OF REVIEW

In humans, cholesterol biosynthesis varies diurnally, reaching its peak at night. Therefore, choosing the time of statin administration is critical because of their different half-lives. Dose timing becomes more important in patients with polypharmacy because it might affect their adherence to the statin therapy.

RECENT FINDINGS

Herein, we narratively summarized the available clinical studies (n = 17) and meta-analyses (n = 2) that compared the morning with the evening dose of statins in terms of safety and efficacy, with special focus on their low-density lipoprotein-lowering effects. We also explained the difference in efficacy results in case of short-acting compared with the long-acting statins and highlighted how flexibility in choosing the time of statin administration is important for better adherence.

SUMMARY

The current limited evidence suggests that short-acting statins should be given in the evening whereas long-acting statins could be given at any time of the day with allowing more patient-based choice (of timing) for better adherence. Lager RCTs with longer durations are recommended to extend and confirm the current evidence.

Meta-Analysis of Creatine for Neuroprotection Against Parkinson's Disease

BACKGROUND

Creatine is an antioxidant agent that showed neuroprotective effects in animal models of Parkinson's disease (PD). Creatine was selected by the National Institute of Neurological Disorders and Stroke as a possible disease modifying agent for Parkinson's disease. Therefore, many clinical trials evaluated the efficacy of creatine for patients with PD. The aim of this systematic review and meta-analysis is to synthesize evidence from published randomized controlled trials (RCTs) about the efficacy of Creatine for patients with PD.

METHODS

We followed PRISMA statement guidelines during the preparation of this systematic review and meta-analysis. A computer literature search for PubMed, EBSCO, web of science and Ovid Midline was carried out. We included RCTs comparing creatine with placebo in terms of motor functions and quality of life. Outcomes of total Unified Parkinson's Disease Rating Scale (UPDRS), UPDRS I, UPDRS II, and UPDRS III were pooled as mean difference (MD) between two groups from baseline to the endpoint. Statistical heterogeneity was assessed by visual inspection of the forest plot and measured by chi-square and I square tests.

RESULTS

Three RCTs (n=1935) were included in this study. The overall effect did not favor either of the two groups in terms of: UPDRS total score (MD 1.07, 95% CI [3.38 to 1.25], UPDRS III (MD 0.62, 95% CI [2.27 to 1.02]), UPDRS II (MD 0.03, 95% CI [0.81 to 0.86], or UPDRS I (MD 0.03, 95% CI [0.33 to 0.28]).

CONCLUSION

Current evidence does not support the use of creatine for neuroprotection against PD. Future well-designed, randomized controlled trials are needed.

Bee venom for the treatment of Parkinson's disease: How far is it possible?

Parkinson's disease (PD) is the second most common neurodegenerative disease, characterized by progressive loss of dopaminergic neurons in the substantia nigra pars compacta leading to depletion of striatal dopamine and motor symptoms as bradykinesia, resting tremors, rigidity, and postural instability. Current therapeutic strategies for PD are mainly symptomatic and may cause motor complications, such as motor fluctuations and dyskinesia. Therefore, alternative medicine may offer an effective adjuvant treatment for PD. Bee venom therapy (BVT) has long been used as a traditional therapy for several conditions, such as rheumatoid arthritis, asthma, and skin diseases. Experimental and clinical studies showed that BVT could be an effective adjuvant treatment for PD. Several mechanisms were suggested for these findings including the ability of BVT to attenuate neuroinflammation, inhibit apoptosis of dopaminergic neurons, protect against glutamate-induced neurotoxicity, and restore normal dopamine levels in the nigrostriatal pathway. In this article, we reviewed and summarized the literature regarding the potential of BVT for the treatment of PD.

D-003 (Saccharum officinarum): The forgotten lipid-lowering agent

Reduction of elevated cholesterol levels, particularly low-density lipoprotein cholesterol (LDL-C), is essential in primary and secondary prevention of cardiovascular disease (CVD). Therefore there is still a large need for new effective drugs, which would be able to essentially reduce LDL-C and in the consequence CV residual risk. D-003 is a mixture of high aliphatic primary acids purified from sugarcane (Saccharum officinarum) wax. It showed promising hypocholesterolemic effects in both animal and human studies; it significantly lowers both serum total cholesterol (TC) and LDL-C, and increases high-density lipoprotein cholesterol (HDL-C). In addition, it showed a favorable safety profile. In this review, we evaluated the profile of D-003 as a lipid-lowering agent based on data from available preclinical and clinical studies.

Dexamethasone combined with other antiemetics versus single antiemetics for prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy: An updated systematic review and meta-analysis

OBJECTIVE

A systematic review and meta-analysis of published randomized controlled trials was performed to update the present evidence about the safety and efficacy of dexamethasone combined with other antiemetics versus single antiemetics for the prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy.

METHODS

A computer literature search of PubMed, Scopus, Web of Science and Embase was conducted to identify the relevant randomized controlled trials. In addition, a manual search of reference lists of the retrieved articles was conducted. Relevant outcomes were pooled as odds ratio (OR) by RevMan version 5.3 for windows.

RESULTS

Pooled data from 14 RCTs (1542 patients) favored dexamethasone combined with other antiemetics over single antiemetics as a prophylaxis against postoperative nausea and vomiting after laparoscopic cholecystectomy in the early postoperative period (OR = 0.39, 95% CI [0.27 to 0.54], p < 0.00001), late postoperative period (OR = 0.36, 95% CI [0.23 to 0.56], p < 0.00001), and overall postoperative period (OR = 0.34, 95% CI [0.23 to 0.51], p < 0.00001). Subsequently, rescue antiemetic usage was significantly lower in the combination group (OR = 0.25, 95% CI [0.16 to 0.41], p < 0.00001). Subgroup analysis showed that all combinations of dexamethasone and other antiemetics were superior to corresponding singel antiemetics except for the combination of dexamethasone and ramosetron which was not superior to ramosetron alone in all postoperative periods and the combination of dexamethasone and granisetron which was not superior to granisetron alone in the early postoperative period (OR = 0.26, 95% CI [0.07 to 1.01], p = 0.05). For all adverse events, there was no significant difference between the two groups.

CONCLUSION

Dexamethasone combined with other antiemetics provided better prophylaxis than single antiemetics against postoperative nausea and vomiting after laparoscopic cholecystectomy. The underlying mechanism of dexamethasone action and its optimal dose should be further investigated.

Effects of partial liquid ventilation with perfluorodecalin in the juvenile rabbit lung after saline injury

OBJECTIVE

To evaluate the feasibility of using the perfluorochemical, perfluorodecalin, for partial liquid ventilation (PLV) with respect to gas exchange and lung mechanics in normal and saline-injured lungs of juvenile rabbits.

DESIGN

Experimental, prospective, randomized, controlled study.

SETTING

Physiology laboratory at a university medical school.

SUBJECTS

Seventeen juvenile rabbits assigned to three groups.

INTERVENTIONS

The conventional mechanical ventilation (CMV)-injury group (n = 5) was treated with CMV after establishing a lung injury; the PLV-injury group (n = 6) was treated with PLV after lung injury; and the PLV-healthy group (n = 6) was supported with PLV without lung injury. Lung injury was created by repeated saline lung lavages. PLV-treated animals received a single dose of intratracheal perfluorodecalin at a volume equal to the measured preinjury gas functional residual capacity (functional residual capacity = 18.6+/-1.5 [SEM] mL/kg).

MEASUREMENTS AND MAIN RESULTS

Sequential measurements of total respiratory compliance and arterial blood chemistries were performed in all groups. Oxygenation index (OI) and ventilation efficiency index were calculated. After lung injury, there was a significant (p < .05) decrease in PaO2, total respiratory compliance, and ventilation efficiency index and an increase in OI and PaCO2. In the PLV-injury group, PLV significantly (p < .05) improved PaO2 (+60%) and OI (-33%) over time. Compliance was significantly (p < .05) higher (90%) than in the CMV-injury group over time.

CONCLUSIONS

These results demonstrate that PLV with perfluorodecalin improved oxygenation and increased respiratory compliance in the saline-injured rabbit lung. In addition, similar to the effects of several other perfluorochemical liquids on normal lungs, pulmonary administration of perfluorodecalin was associated with a small impairment in gas exchange and a significant decrease in lung compliance in the juvenile rabbit model.

Pharmacologic approaches for the management of systemic hypertension in pregnancy

Hypertension in pregnancy includes a group of distinct disorders that require special consideration in both prevention and pharmacologic treatment. In recent years, there have been few advances regarding the pathophysiology and prevention of preeclampsia, or in recommendations for first-line drug therapy of the hypertensive complications of preeclampsia. Similarly, the recommendations for pharmacologic treatment of women with chronic hypertension antedating pregnancy have changed little, primarily because first-line medications have the advantage of having been the subjects of extensive research experience. Recent clinical trials have demonstrated the efficacy and safety of various second-line drugs for treating hypertensive disorders of pregnancy; whether these therapies can eventually replace the standard recommended medications will require more extensive long-term investigation.

Generation of natural killer cells from both Fc gamma RII/III+ and Fc gamma RII/III- murine fetal liver progenitors

In vitro culture of day-15.5 murine fetal liver (FL) cells in the presence of recombinant interleukin-2 (IL-2) results in the expansion of Fc gamma RII/III+ CD3-Ti-NK1.1+ cells displaying both natural killer (NK) and antibody-dependent cell cytotoxicity (ADCC) cytolytic activities. These FL-derived NK cells express Fc gamma RIII (CD16) in association with an Fc epsilon RI gamma homodimer on their surface. In contrast, in vitro expansion of FL cells in the absence of IL-2 generates noncytotoxic cells belonging to the myelomonocytic lineage (Mac1+Gr1+NK1.1-). Hence, IL-2 appears to be critical for the proliferation and differentiation of NK cells from FL progenitors. Experiments in which FL cells were fractionated by density gradient centrifugation before in vitro expansion showed that NK progenitors are contained within a cell population with a density of 1.04 < d < 1.08 g/mL. Cells with d > 1.08 g/mL (representing > or = 40% of FL cells) have no such NK progenitor activity. In addition, after intrathymic injection into Ly5 congenic host animals, day-15.5 CD4-CD8- FL cells mature into CD4+CD8+ thymocytes within 12 days. Interestingly, this T-cell progenitor activity is restricted to subpopulations of FL cells that also contain NK progenitors, but is absent in high-density (d > 1.08 g/mL) FL cells. Finally, fractionation of FL cells according to surface expression of Fc gamma RII/III complexes shows that NK (and T-lymphocyte) progenitors are found in both Fc gamma RII/III+ and Fc gamma RII/III-FL subpopulations.

Fc gamma RII/III and CD2 expression mark distinct subpopulations of immature CD4-CD8- murine thymocytes: in vivo developmental kinetics and T cell receptor beta chain rearrangement status

We have recently identified a dominant wave of CD4-CD8- (double-negative [DN]) thymocytes in early murine fetal development that express low affinity Fc gamma receptors (Fc gamma RII/III) and contain precursors for Ti alpha/beta lineage T cells. Here we show that Fc gamma RII/III is expressed in very immature CD4low single-positive (SP) thymocytes and that Fc gamma RII/III expression is downregulated within the DN subpopulation and before the CD3-CD8low SP stage in T cell receptor (TCR)-alpha/beta lineage-committed thymocytes. DN Fc gamma RII/III+ thymocytes also contain a small fraction of TCR-gamma/delta lineage cells in addition to TCR-alpha/beta progenitors. Fetal day 15.5 DN TCR-alpha/beta lineage progenitors can be subdivided into three major subpopulations as characterized by cell surface expression of Fc gamma RII/III vs. CD2 (Fc gamma RII/III+CD2-, Fc gamma RII/III+CD2+, Fc gamma RII/III-CD2+). Phenotypic analysis during fetal development as well as adoptive transfer of isolated fetal thymocyte subpopulations derived from C57B1/6 (Ly5.1) mice into normal, nonirradiated Ly5.2 congenic recipient mice identifies one early differentiation sequence (Fc gamma RII/III+CD2(-)-->Fc gamma RII/III+CD2(+)-->Fc gamma RII/III-CD2+) that precedes the entry of DN thymocytes into the CD4+CD8+ double-positive (DP) TCRlow/- stage. Unseparated day 15.5 fetal thymocytes develop into DP thymocytes within 2.5 d and remain at the DP stage for > 48 h before being selected into either CD4+ or CD8+ SP thymocytes. In contrast, Fc gamma RII/III+CD2- DN thymocytes follow this same developmental pathway but are delayed by approximately 24 h before entering the DP compartment, while Fc gamma RII/III-CD2+ display accelerated development by approximately 24 h compared with total day 15.5 thymocytes. Fc gamma RII/III-CD2+ are also more developmentally advanced than Fc gamma RII/III+CD2- fetal thymocytes with respect to their TCR beta chain V(D)J rearrangement. At day 15.5 in gestation, beta chain V(D)J rearrangement is mostly, if not entirely, restricted to the Fc gamma RII/III-CD2+ subset of DN fetal thymocytes. Consistent with this analysis in fetal thymocytes, > 90% of adult thymocytes derived from mice carrying a disrupting mutation at the recombination-activating gene 2 locus (RAG-2-/-) on both alleles are developmentally arrested at the DN CD2- stage. In addition, there is a fivefold increase in the relative percentage of thymocytes expressing Fc gamma RII/III in TCR and immunoglobulin gene rearrangement-incompetent homozygous RAG-2-/- mice (15% Fc gamma RII/III+) versus rearrangement-competent heterozygous RAG-2+/- mice (< 3% Fc gamma RII/III+). Thus, Fc gamma RII/III expression defines an early DN stage preceding V beta(D beta)I beta rearrangement, which in turn is followed by surface expression of CD2. Loss of Fc gamma RII/III and acquisition of CD2 expression characterize a late DN stage immediately before the conversion into DP thymocytes.