Schwann cell-derived exosomes: Janus-faced mediators of regeneration and disease

The phenotypic plasticity of Schwann cells (SCs) has contributed to the regenerative potential of the peripheral nervous system (PNS), but also pathological processes. This double-sided effect has led to an increasing attention to the role of extracellular vesicles (EVs) or exosomes in SCs to examine the intercellular communication between SCs and their surroundings. Here, we first describe the current knowledge of SC and EV biology, which forms the basis for the updates on advances in SC-derived exosomes research. We seek to explore in-depth the exosome-mediated molecular mechanisms involved in the regulation of SCs and their microenvironment. This review concludes with potential applications of SC-derived exosomes as delivery vehicles for therapeutics and biomarkers. The goal of this review is to emphasize the crucial role of SC-derived exosomes in the functional integration of the PNS, highlighting an emerging area in which there is much to explore and re-explore.     

CpG-mediated changes in gene expression in murine spleen cells identified by microarray analysis

Unmethylated CpG motifs interact with Toll-like receptor 9 (TLR9), triggering an innate immune response characterized by the production of cytokines, chemokines and immunoglobulins. Microarray analysis of cDNA from murine spleen cells stimulated with CpG oligodeoxynucleotides (ODN) identified reproducible changes in gene expression over time. Eight genes are significantly up-regulated 2h post CpG ODN stimulation, most of which contribute to the induction of innate or adaptive immune responses. Network analysis indicates that TNF and NFKB1 are key regulators of gene expression at this early time point. At 4h, IL1B in addition to TNF and NFKB1 play dominant roles in the up-regulation of immune gene expression, whereas by 8h this function is mediated by TNF, IFNG, and MYC. Genes responsible for down-regulating CpG-induced responses were also identified, dampening what would otherwise be a continuous positive feedback loop. This work provides novel insights into the regulatory process embedded in the gene expression profile induced by CpG ODN, identifies novel genes associated with CpG-induced immune stimulation, and clarifies the breadth of the immune response elicited via TLR9.     

Effect of octenidine dihydrochloride on viability of protoscoleces in hepatic and pulmonary hydatid diseases

BACKGROUND: Use of effective scolicidal agents during puncture, aspiration or injection of a scolicidal agent and reaspiration (PAIR) and surgery for hydatid cysts are essential to reduce the recurrence rate. In this in vitro study, we tried to determine the scolicidal property of a new agent, octenidine dihydrochloride, and of various agents in different concentrations and exposure times. MATERIAL AND METHODS: Echinococcus granulosus protoscoleces were obtained from six patients with liver (n=3) and lung (n=3) hydatid cysts. Various concentrations of octenidine dihydrochloride (0.1%, 0.01% and 0.001% diluted form), povidone iodine (10%, 1% and 0.1% diluted) and 20% saline were used in this study. Viability of protoscoleces was determined with dye-uptake (0.1% eosin) and flame cell activity. RESULTS: Octenidine dihydrochloride 0.1% had strong scolicidal effect in 15 min and octenidine dihydrochloride 0.01% in 30 min. Sixty percent of protoscoleces lost viability at 5 min with octenidine dihydrochloride 0.1%. Viability ratio decreased to 20% at 10 min, and all of them died at 15 min. Povidone iodine 10% and 1% had strong scolicidal effects after 15- and 30 min of exposure, respectively. Saline 20% killed all the protoscoleces in 30-min exposure. CONCLUSION: Because of the rapid and strong scolocidal effectiveness of octenidine dihydrochloride on protoscoleces, it may be used as a scolocidal agent during both perioperative and in the PAIR method.     

Learning and memory performance following acute intranasal insulin administration in abstinent smokers

The highest incidence of relapse to smoking occurs within the first 2 weeks of a cessation attempt. In addition to enhanced nicotine craving, this phase of smoking cessation is also marked by learning and memory dysfunction. Many smokers are not able to overcome these symptoms, and they relapse to smoking shortly after trying to quit. In two clinical studies, we evaluated intranasal insulin for efficacy in improving learning and memory function during nicotine withdrawal. Our first study was a crossover evaluation (N = 19) following 20 hr of smoking abstinence. Study 2 was a parallel design study (N = 50) following 16 hr of abstinence. Intranasal insulin (60 IU) dose was administered in both studies and cognitive function was measured using California Verbal Learning Test‐II. Intranasal insulin did not improve learning over the 5 verbal learning trials. In addition, intranasal insulin did not improve either short‐ or long‐delay recall in either study. In summary, the one‐time administration of intranasal insulin does not improve verbal learning and memory in smokers. Whether longer administration schedules may be of benefit should be evaluated in future studies.     

Coronary artery thromboembolism: Unexpected presentation of left atrial myxoma covered with thrombus

Cardiac myxomas are benign primer cardiac tumors of the heart. They can be fatal with a thromboembolic presentation. Myocardial infarction is one of these unusual thromboembolic presentations. We report a patient who presented with cardiac arrest due to ventricular fibrillation related to myocardial infarction. After successful resuscitation, coronary angiography and transthoracic echocardiography were performed. A left atrial mass was observed and interpreted as a possible cause of coronary embolism leading to myocardial infarction. After surgical excision, the pathological examination confirmed myxoma, which was the essential cause of the tendency to arterial embolism.     

Intraoperative corneal thickness measurements during corneal collagen cross-linking with isotonic riboflavin solution without dextran in corneal ectasia

Objective: To monitor the changes in corneal thickness during the corneal collagen cross-linking procedure by using isotonic riboflavin solution without dextran in ectatic corneal diseases.

Materials and Methods: The corneal thickness measurements were obtained before epithelial removal, after epithelial removal, following the instillation of isotonic riboflavin solution without dextran for 30?min, and after 10?min of ultraviolet A irradiation.

Results: Eleven eyes of eleven patients with progressive keratoconus (n?=?10) and iatrogenic corneal ectasia (n?=?1) were included in this study. The mean thinnest pachymetric measurements were 391.82?±?30.34?µm (320–434?µm) after de-epithelialization of the cornea, 435?±?21.17?µm (402–472?µm) following 30?min instillation of isotonic riboflavin solution without dextran and 431.73?±?20.64?µm (387–461?µm) following 10?min of ultraviolet A irradiation to the cornea.

Conclusion: Performing corneal cross-linking procedure with isotonic riboflavin solution without dextran might not induce corneal thinning but a little swelling throughout the procedure.     

Effects of the recreational use of PDE5 inhibitors on the corpus cavernosum of young,healthy rats

Purpose

PDE5 inhibitors are widely used for the treatment of erectile dysfunction. However, these drugs have recently become popular among men without erectile dysfunction as a means of enhancing sexual performance and improving sexual desire. The aim of this study was to investigate the histopathological and ultrastructural effects of PDE5 inhibitors on the corpus cavernosum in young, healthy male rats.

Methods

Twenty-four 4-month-old male rats were divided into four groups: group 1 was the control group, group 2 rats received sildenafil citrate, group 3 rats received vardenafil hydrochloride, and group 4 rats received tadalafil. All drugs were administered for 4 weeks. Penile tissue was collected for electron microscopy and tissue collagen measurements. Electron microscopic analysis indicated that the number of active fibroblasts and macrophages and the synthesis of new collagen fibers increased in treated rats.

Results

Cavernous tissue collagen levels were significantly higher in the sildenafil-, vardenafil-, and tadalafil-treated groups than in controls (46.16 ± 4.9, 42.06 ± 2.4, 41.07 ± 2.4, and 29.20 ± 3.3, respectively) (p < 0.001).

Conclusions

Young men who use these drugs to enhance performance in the absence of erectile dysfunction may experience irreversible damage to the cavernosal tissue. However, more studies are needed to evaluate the molecular mechanisms by which PDE5 inhibitors affect the corpus cavernosum.     

Laser Powder Bed Fusion of Polymers: Quantitative Research Direction Indices

Research on Laser Powder Bed Fusion (L-PBF) of polymer powder feedstocks has raised over the last decade due to the increased utilization of the fabricated parts in aerospace, automotive, electronics, and healthcare applications. A total of 600 Science Citation Indexed articles were published on the topic of L-PBF of polymer powder feedstocks in the last decade, being cited more than 10,000 times leading to an h-index of 46. This study statistically evaluates the 100 most cited articles to extract reported material, process, and as-built part properties to analyze the research trends. PA12, PEEK, and TPU are the most employed polymer powder feedstocks, while size, flowability, and thermal behavior are the standardly reported material properties. Likewise, process properties such as laser power, scanning speed, hatch spacing, powder layer thickness, volumetric energy density, and areal energy density are extracted and evaluated. In addition, material and process properties of the as-built parts such as tensile test, flexural test, and volumetric porosity contents are analyzed. The incorporation of additives is found to be an effective route to enhance mechanical and functional properties. Carbon-based additives are typically employed in applications where mechanical properties are essential. Carbon fibers, Ca-phosphates, and SiO₂ are the most reported additives in the evaluated SCI-expanded articles for L-PBF of polymer powder feedstocks. A comprehensive data matrix is extracted from the evaluated SCI-index publications, and a principal component analysis (PCA) is performed to explore correlations between reported material, process, and as-built parts.