The processing of ultrafine-grained Mg tubes for biodegradable stents

An investigation was carried out on equal-channel angular pressing (ECAP) and extrusion processing of a ZM21 Mg alloy to obtain an improved candidate material for the manufacturing of biodegradable Mg stents. Ultrafine-grain size billets of the ZM21 alloy were obtained by two-stage ECAP aimed at achieving an initial refining of the structure at 200 °C and then reaching the submicrometer grain size range by lowering the processing temperature down to 150 °C. The investigation revealed a significant improvement in the properties of the ECAP-treated samples compared with the starting coarse-grained ZM21 alloy. The 0.2% yield strength rose from 180 to 340 MPa after 150 °C ECAP processing, while maintaining a fairly high tensile ductility. The ultrafine ZM21 alloy billets were then used for the extrusion of stent precursors having the form of small-size tubes. The grain size after extrusion remained in the submicrometer range while the hardness was revealed to be significantly higher than that of the coarse-grained ZM21 Mg alloy. It was demonstrated that processing of biodegradable Mg stent having an ultrafine-grained microstructure by ECAP and low-temperature extrusion is feasible and that the obtained products feature promising properties.     

Home-based exercise therapy in patients with ankylosing spondylitis: effects on pain, mobility, disease activity, quality of life, and respiratory functions

The home-based exercise therapy recommended to the patients with ankylosing spondylitis (AS) is a simply applicable and cheap method. The aim of this study was to investigate the effects of home-based exercise therapy on pain, mobility, function, disease activity, quality of life, and respiratory functions in patients with AS. Eighty patients diagnosed with AS according to the modified New York criteria were included in the study. Home-based exercise program including range of motion, stretching, strengthening, posture, and respiratory exercises was practically demonstrated by a physiotherapist. A training and exercise manual booklet was given to all patients. Patients following home-based exercise program five times a week at least 30 min per session (exercise group) for 3 months were compared with those exercising less than five times a week (control group). Visual analog scale pain (VASp) values at baseline were significantly higher in the exercise group. The exercise group showed improvements in VASp, tragus–wall distance, morning stiffness, finger–floor distance, modified Schober's test, chest expansion, the Bath Ankylosing Spondylitis Disease Activity Index, the Bath Ankylosing Spondylitis Functional Index, Ankylosing Spondylitis Quality of Life Questionnaire (ASQoL), forced expiratory volume in first second, and forced vital capacity at third month. There was significant difference in ASQoL scores between the two groups in favor of the exercise group at third month. Regular home-based exercise therapy should be a part of main therapy in patients with AS. Physicians should recommend that patients with AS do exercise at least five times a week at least 30 min per session.     

Does anti-tnf therapy cause any change in platelet activation in ankylosing spondylitis patients?

Recently, it has been reported that ankylosing spondylitis (AS) was characterised by endothelial dysfunction and the development of atherosclerotic complications. In this study, we evaluated platelet and endothelial activation parameters in AS patients. Fiftynine AS patients and 22 healthy controls were included. The clinical features and acute phase parameters were evaluated. In all patients and healthy controls, platelet-monocyte complexes (PMC), platelet-neutrophil complexes, basal and ADP-stimulated P-selectin (CD62P) expression were determined by flow cytometry; soluble E-selectin (sE-selectin) and soluble CD40L (sCD40L) were determined by ELISA. AS patients were divided into two groups as active and inactive by using BASDAI. In 15 AS patients, the evaluated parameters were assessed before and after 12 weeks of anti-TNF therapy. PMC and sCD40L levels in AS patients were significantly higher than in the control group (P values 0.013 and 0.016). The evaluated variables were similar in active and inactive AS groups (P > 0.05). There were no significant changes in platelet and endothelial activation parameters in AS patients after anti-TNF therapy (P > 0.05). Platelet activation which is reflected by high levels of PMC and sCD40L might be responsible for the increased frequency of atherosclerosis in AS. The platelet activation in our AS patients was not associated with disease activity and did not improve after anti-TNF therapy.     

Microvascular and functional changes according to the fundus location of the affected arteriovenous crossing in patients with branch retinal vein occlusion

Purpose:The aim of this study was to evaluate the structural and functional changes occurring in patients with branch retinal vein occlusion (BRVO) according to the distance of the affected arteriovenous (AV) crossing to the centers of the fovea and optic disc by optic coherence tomography angiography (OCTA).Methods:Forty-five patients with unilateral BRVO and 45 age- and sex-matched healthy controls were included in this retrospective observational study. Images of the macula (3 mm × 3 mm) and affected AV crossing sites were obtained by OCTA. The fovea-AV crossing distance (FAVD), optic disc-AV crossing distance (DAVD), and optic disc-fovea distance (DFD) were measured.Results:The FAVD/DFD ratio was positively correlated with the vessel density in the superficial and deep affected hemifields (r = 0.430, P < 0.05 and r = 0.308, P < 0.05, respectively) and negatively correlated with the superficial foveal avascular zone and logarithm of the minimum angle of resolution (logMAR) visual acuity (r = –0.412, P < 0.05 and r = –0.356, P < 0.05, respectively). The DAVD/DFD ratio was not correlated with the logMAR visual acuity, superficial FAZ area or vessel densities in the affected hemifield (all P > 0.05).Conclusion:The affected AV crossing site that was further away from the fovea had better visual acuity and quantitative microvascular parameters in the affected hemifields. However, this correlation was not observed for the distance between the affected AV crossing site and the optic disc.     

Lymph Node Ratio May Be Supplementary to TNM Nodal Classification in Node-positive Breast Carcinoma Based on the Results of 2,151 Patients

Background

The aim of the present study was to determine how lymph node ratio (LNR; the ratio of the number of metastatic lymph nodes to the number of removed lymph nodes) can supplement the TNM nodal classification in breast carcinoma.

Methods

We retrospectively reviewed the file records of 2,151 patients.

Results

Lymph node ratio-based low- (LNR ≤ 0.20), intermediate- (LNR 0.21–0.65), and high-risk (LNR > 0.65) patient groups had significantly different disease-free survival (DFS) (P < 0.001). The DFS of patients with N1, N2, and N3 disease was significantly different (P < 0.001). When LNR and TNM nodal groupings were included together in the Cox analysis, both groupings had independent prognostic significance (P < 0.001 and P < 0.001, respectively). The most significant LNR threshold value separating patients in low-risk and high-risk groups in terms of disease recurrence was 0.20 for N1 disease (P < 0.001), 0.35 for N2 disease (P < 0.001), and 0.90 for N3 disease (P < 0.001).

Conclusions

Lymph node ratio and TNM nodal groupings show no superiority over each other in categorizing patients with node-positive breast carcinoma into prognostic groups of low-, intermediate-, and high-risk. However, LNR grouping may supplement TNM nodal classification by categorizing patients within each TNM nodal group into low-risk and high-risk groups with significantly different survival.     

Higher Incidence of Cholelithiasis in Chronic Renal Failure Patients with Secondary Hyperparathyroidism Undergoing Peritoneal Dialysis

Background. In this study, we endeavored to determine whether the incidence of cholelithiasis (CL) was increased in chronic renal failure (CRF) patients with secondary hyperparathyroidism on a peritoneal dialysis (PD) program. We also evaluated the factors that might have some influence on the development of CL. Methods. A total of 59 CRF patients undergoing PD were included in the study. We studied the following groups to determine whether parathyroid hormone (PTH) levels were increased in CRF-PD patients: twenty patients with secondary hyperparathyroidism (group 1) and 39 patients with normal PTH levels (group 2). PTH levels were maintained at three times the upper limit of normal. Biochemical parameters were obtained for each CRF-PD patient. All patients underwent abdominal ultrasonography to screen for the presence of cholelithiasis. For statistical analysis, χ², t test, and logistic regression analysis were used; p < 0.05 was considered as significant. Results. We found an almost ten times higher incidence (25% vs. 2.6%) of CL in group 1 patients with statistical significance (p = 0.007). When the incidence of CL according to sex, creatinine, and PTH levels were considered, female gender, creatinine, and PTH levels were higher in group 1, which was also significant statistically. No significant relationship was detected between gallbladder stone formation and the other analyzed biochemical parameters. Conclusions. We found that the incidence of CL in CRF-PD patients with secondary hyperparathyroidism was higher than CRF-PD patients with normal PTH levels. It was also detected that female gender, high creatinine levels, and elevated PTH levels might influence the development of CL in CRF-PD patients.     

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.