Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering

In this study entitled “Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering”, we describe the development of novel hydroxyapatite (HAp)-filled osteoinductive piezoelectric poly(vinylidene fluoride-cotetrafluoroethylene) (PVDF-TrFE) electrospun nanofibers as a potential strategy for supporting bone repair in delayed-union and non-union osteoporotic-related fractures, for which current clinical techniques have proven to be largely inadequate and scaffold-based tissue engineering approaches hold significant promise. While the piezoelectric properties of native bone tissue have been extensively discussed in the literature, including their key role in preserving tissue homeostasis and promoting tissue repair, they have been widely neglected in the design of scaffolds for bone tissue engineering (BTE) applications. Piezoelectric scaffolds can be used not only for mimicking the native piezoelectric features of bone but also to provide a platform for applying electrical or mechanical stimuli to damaged tissue, contributing to an accelerated regeneration process. The nanofibrous scaffolds generated in this study were capable of replicating the main electrical, structural and compositional properties of bone extracellular matrix (ECM). To the best of our knowledge, this was the first time that the combination of HAp with the piezoelectric polymer PVDF-TrFE was found to induce key shifts in the chemical structure of the polymer and promote ß phase nucleation, not only enhancing the piezoelectric features of the constructs but also improving their surface properties, including their ability to support mineralization in vitro. The HAp nanoparticles also provided meaningful bone-like biological cues (osteoinduction), enhancing the osteogenic differentiation of seeded human mesenchymal stem/stromal cells (hMSCs), which was confirmed by an increased ALP activity, cellderived calcium deposition and expression of important osteogenic gene markers. Overall, our findings highlight, for the first time, the potential of combining PVDFTrFE and HAp for developing electroactive and osteoinductive nanofibrous constructs with improved piezoelectric properties, surface features and osteogenic potential capable of improving bone tissue regeneration.Peer ReviewedPostprint (published version

Impact of Remote Monitoring on Standardized Outcomes in Nephrology-Peritoneal Dialysis

Introduction: This study aimed to evaluate the association between the use of remote patient monitoring (RPM) in patients on automated peritoneal dialysis (APD) and the Standardized Outcomes in Nephrology in peritoneal dialysis (SONG-PD) clinical outcomes. Methods: A prospective and multicenter cohort study was conducted on patients with advanced chronic kidney disease on APD, recruited at 16 Spanish Hospitals, between June 1 and December 31, 2021. Patients were divided into 2 cohorts, namely patients on APD with RPM (APD-RPM) and patients on APD without RPM. The primary endpoints were the standardized outcomes of the SONG-PD clinical outcomes: PD-associated infection, cardiovascular disease (CVD), mortality rate, technique survival, and life participation (assessed as health-related quality of life [QoL]). Propensity score matching (PSM) was used to evaluate the association of RPM exposure with the clinical outcomes. Results: A total of 232 patients were included, 176 (75.9%) in the APD-RPM group and 56 (24.1%) in the APD-without-RPM group. The mean patient follow-up time was significantly longer in the APD-RPM group than in the APD-without-RPM group (10.4 ± 2.8 vs. 9.4 ± 3.1 months, respectively; P = 0.02). In the overall study sample, the APD-RPM group was associated with a lower mortality rate (hazard ratio [HR]: 0.08; 95% confidence interval [CI]: 0.01 to 0.69; P = 0.020) and greater technique survival rate (HR: 0.25; 95% CI: 0.11 to 0.59; P = 0.001). After PSM, APD-RPM continued to be associated with better technique survival (HR: 0.23; 95% CI: 0.06 to 0.83; P = 0.024). Conclusion: The use of RPM programs in patients on APD was associated with better survival of the technique and lower mortality rates. However, after PSM, only technique survival was significant

Recombination in pe/ppe genes contributes to genetic variation in Mycobacterium tuberculosis lineages

Background: Approximately 10 % of the Mycobacterium tuberculosis genome is made up of two families of genes that are poorly characterized due to their high GC content and highly repetitive nature. The PE and PPE families are typified by their highly conserved N-terminal domains that incorporate proline-glutamate (PE) and proline-proline-glutamate (PPE) signature motifs. They are hypothesised to be important virulence factors involved with host-pathogen interactions, but their high genetic variability and complexity of analysis means they are typically disregarded in genome studies.// Results: To elucidate the structure of these genes, 518 genomes from a diverse international collection of clinical isolates were de novo assembled. A further 21 reference M. tuberculosis complex genomes and long read sequence data were used to validate the approach. SNP analysis revealed that variation in the majority of the 168 pe/ppe genes studied was consistent with lineage. Several recombination hotspots were identified, notably pe_pgrs3 and pe_pgrs17. Evidence of positive selection was revealed in 65 pe/ppe genes, including epitopes potentially binding to major histocompatibility complex molecules.// Conclusions: This, the first comprehensive study of the pe and ppe genes, provides important insight into M. tuberculosis diversity and has significant implications for vaccine development

Is it really advantageous to operate proximal femoral fractures within 48 h from diagnosis? – A multicentric retrospective study exploiting COVID pandemic-related delays in time to surgery

Objectives: Hip fractures in the elderly are common injuries that need timely surgical management. Since the beginning of the pandemic, patients with a proximal femoral fracture (PFF) experienced a delay in time to surgery. The primary aim of this study was to evaluate a possible variation in mortality in patients with PFF when comparing COVID-19 negative versus positive. Methods: This is a multicentric and retrospective study including 3232 patients with PFF who underwent surgical management. The variables taken into account were age, gender, the time elapsed between arrival at the emergency room and intervention, pre-operative American Society of Anesthesiology score, pre-operative cardiovascular and respiratory disease, and 10-day/1-month/6-month mortality. For 2020, we had an additional column, “COVID-19 swab positivity.” Results: COVID-19 infection represents an independent mortality risk factor in patients with PFFs. Despite the delay in time-to-surgery occurring in 2020, no statistically significant variation in terms of mortality was detected. Within our sample, a statistically significant difference was not detected in terms of mortality at 6 months, in patients operated within and beyond 48 h, as well as no difference between those operated within or after 12/24/72 h. The mortality rate among subjects with PFF who tested positive for COVID-19 was statistically significantly higher than in patients with PFF who tested. COVID-19 positivity resulted in an independent factor for mortality after PFF. Conclusion: Despite the most recent literature recommending operating PFF patients as soon as possible, no significant difference in mortality was found among patients operated before or after 48 h from diagnosis

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Influence of clinical and neurocognitive factors in psychosocial functioning after a first episode non-affective psychosis: differences between males and females

BackgroundDeficits in psychosocial functioning are present in the early stages of psychosis. Several factors, such as premorbid adjustment, neurocognitive performance, and cognitive reserve (CR), potentially influence functionality. Sex differences are observed in individuals with psychosis in multiple domains. Nonetheless, few studies have explored the predictive factors of poor functioning according to sex in first-episode psychosis (FEP). This study aimed to explore sex differences, examine changes, and identify predictors of functioning according to sex after onset.Materials and methodsThe initial sample comprised 588 individuals. However, only adults with non-affective FEP (n = 247, 161 males and 86 females) and healthy controls (n = 224, 142 males and 82 females) were included. A comprehensive assessment including functional, neuropsychological, and clinical scales was performed at baseline and at 2-year follow-up. A linear regression model was used to determine the predictors of functioning at 2-year follow-up.ResultsFEP improved their functionality at follow-up (67.4% of both males and females). In males, longer duration of untreated psychosis (β = 0.328, p = 0.003) and worse premorbid adjustment (β = 0.256, p = 0.023) were associated with impaired functioning at 2-year follow-up, while in females processing speed (β = 0.403, p = 0.003), executive function (β = 0.299, p = 0.020) and CR (β = −0.307, p = 0.012) were significantly associated with functioning.ConclusionOur data indicate that predictors of functioning at 2-year follow-up in the FEP group differ according to sex. Therefore, treatment and preventative efforts may be adjusted taking sex into account. Males may benefit from functional remediation at early stages. Conversely, in females, early interventions centered on CR enhancement and cognitive rehabilitation may be recommended

Effectiveness of treatment with oral paricalcitol in patients on peritoneal dialysis: a Spanish multicenter study

[Abstract] Aims: Recently, oral form of paricalcitol has allowed extension of treatment to ambulatory patients on peritoneal dialysis but few data have been published about the benefits of paricalcitol in this subgroup. A multicenter, retrospective study was carried out to increase current knowledge on the effectiveness and safety of paricalcitol in 162 peritoneal dialyzed patients with secondary hyperparathyroidism. Methods: Case histories of patients treated with paricalcitol for at least 6 months were reviewed to extract data on 12 biochemical parameters related to bone disease and health status. Changes in these parameters were described. Doses of paricalcitol and other concomitant treatments were evaluated at least every 3 months. Results: 99 men (61.1%) and 63 women (38.9%) with an average age of 62.07 years were included. PTH levels showed an acute decrease in the three first months (35.88%) and a global decrease at month 6 of 42.39%. A slight increase in calcium was observed (p < 0.001) but it remained between normal range values. Only 5 patients presented serum calcium over 10.2 in two consecutive measurements. No changes were found in phosphorus, calcium-phosphorus product, hemoglobin, alkaline phosphatase, GGT, albumin, PCR inflammatory markers, pH and bicarbonate. The decrease in proteinuria levels was nearly statistically significant (p = 0.061). Only 6 patients (0.36%) abandoned the treatment. Conclusions: Paricalcitol therapy was well tolerated with a high effectiveness in patients on peritoneal dialysis. A slight increase in serum calcium levels was observed, although within normal ranges. No changes in other biochemical parameters related to bone disease could be associated to paricalcitol with data compiled in our study. Paricalcitol seems to have a protective effect on proteinuria levels

Enseñanza de las ciencias : revista de investigación y experiencias didácticas

Resumen basado en el de la publicaciónResumen en inglésEl espectacular desarrollo de las técnicas audiovisuales en los últimos años ha proporcionado una gran cantidad de recursos de pedagogía que están claramente infraexplotados. El objetivo fue mejorar esta situación poniendo a disposición de los maestros estos recursos. Para ello, compilamos un catálogo de cintas de vídeo y películas de uso en la enseñanza de la Física y Química para estudiantes universitarios. El catálogo está disponible en dos formatos: como lista impresa y como hipertexto recuperable por computadora y fácil de usar.ES

Mortality in hemodialysis patients with COVID-19, the effect of paricalcitol or calcimimetics

Background: In COVID-19 patients, low serum vitamin D (VD) levels have been associated with severe acute respiratory failure and poor prognosis. In regular hemodialysis (HD) patients, there is VD deficiency and markedly reduced calcitriol levels, which may predispose them to worse outcomes of COVID-19 infection. Some hemodialysis patients receive treatment with drugs for secondary hyperparathyroidism, which have well known pleiotropic effects beyond mineral metabolism. The aim of this study was to evaluate the impact of VD status and the administration of active vitamin D medications, used to treat secondary hyperparathyroidism, on survival in a cohort of COVID-19 positive HD patients. Methods: A cross-sectional retrospective observational study was conducted from 12 March to 21 May 2020 in 288 HD patients with positive PCR for SARS-CoV2. Patients were from 52 different centers in Spain. Results: The percent of HD patients with COVID-19 was 6.1% (288 out of 4743). Mortality rate was 28.4% (81/285). Three patients were lost to follow-up. Serum 25(OH)D (calcidiol) level was 17.1 [10.6-27.5] ng/mL and was not significantly associated to mortality (OR 0.99 (0.97-1.01), p = 0.4). Patients receiving active vitamin D medications (16/94 (17%) vs. 65/191(34%), p = 0.003), including calcimimetics (4/49 (8.2%) vs. 77/236 (32.6%), p = 0.001), paricalcitol or calcimimetics (19/117 (16.2%) vs. 62/168 (36.9%); p < 0.001), and also those on both paricalcitol and calcimimetics, to treat secondary hyperparathyroidism (SHPTH) (1/26 (3.8%) vs. 80/259 (30.9%), p < 0.001) showed a lower mortality rate than patients receiving no treatment with either drug. Multivariate Cox regression analysis confirmed this increased survival. Conclusions: Our findings suggest that the use of paricalcitol, calcimimetics or the combination of both, seem to be associated with the improvement of survival in HD patients with COVID-19. No correlation was found between serum VD levels and prognosis or outcomes in HD patients with COVID-19. Prospective studies and clinical trials are needed to support these findings