Design and properties of 3D scaffolds for bone tissue engineering

In this study, the Voronoi tessellation method has been used to design novel bone like three dimension (3D) porous scaffolds. The Voronoi method has been processed with computer design software to obtain 3D virtual isotropic porous interconnected models, exactly matching the main histomorphometric indices of trabecular bone (trabecular thickness, trabecular separation, trabecular number, bone volume to total volume ratio, bone surface to bone volume ratio, etc.). These bone like models have been further computed for mechanical (elastic modulus) and fluid mass transport (permeability) properties. The results show that the final properties of the scaffolds can be controlled during their microstructure and histomorphometric initial design stage. It is also shown that final properties can be tuned during the design stage to exactly match those of trabecular natural bone. Moreover, identical total porosity models can be designed with quite different specific bone surface area and thus, this specific microstructural feature can be used to favour cell adhesion, migration and, ultimately, new bone apposition (i.e. osteoconduction). Once the virtual models are fully characterized and optimized, these can be easily 3D printed by additive manufacturing and/or stereolitography technologies.

STATEMENT OF SIGNIFICANCE

The significance of this article goes far beyond the specific objectives on which it is focussed. In fact, it shows, in a guided way, the entire novel process that can be followed to design graded porous implants, whatever its external shape and geometry, but internally tuned to the exact histomorphometric indices needed to match natural human tissues microstructures and, consequently, their mechanical and fluid properties, among others. The significance is even more relevant nowadays thanks to the available new computing and design software that is easily linked to the 3D printing new technologies. It is this transversality, at the frontier of different disciplines, the main characteristic that gives this article a high scientific impact and interest to a broaden audience.

Prediction of anastomotic leak in colorectal cancer surgery based on a new prognostic index PROCOLE (prognostic colorectal leakage) developed from the meta-analysis of observational studies of risk factors

PURPOSE

To obtain a prognostic index, which has been named PROCOLE (prognostic colorectal leakage), it can predict the risk that a certain individual may suffer anastomotic leakage.

METHODS

The methodology consists of a systematic review to identify potential risk factors for anastomotic leakage and a meta-analysis of studies of each of these factors. In the meta-analysis, the prognostic index integrates factors that are statistically significant, which are weighted according to the estimated value of the effect size. The prognostic index was validated using retrospectively collected data from patients who underwent colorectal cancer surgery anastomosis at our institution.

RESULTS

The mean and standard deviation of the PROCOLE prognostic index in patients with anastomotic leakage is 1.9 ± 6.13, whereas in controls, it is 3.63 ± 2.1. The predictive ability of the PROCOLE, assessed by calculating the area under the curve (AUC) of the receiver operating characteristic (ROC), results in an AUC of 0.82 with a 95% confidence interval (CI) (0.75, 0.89) of the AUC, and it can be considered a good prognostic indicator.

CONCLUSIONS

The PROCOLE prognostic index predicts the risk of a certain individual developing anastomotic leakage after colorectal cancer surgery. Specifically, the PROCOLE prognostic index establishes a discrimination value threshold of 4.83 for recommending the implementation of a protective stoma. We have developed free software with a simple interface that only requires the selection of risk factors to obtain the PROCOLE value.

One Health in Practice: A Pilot Project for Integrated Care of Zoonotic Infections in Immunocompromised Children and Their Pets in Chile

Although pets provide physiological and psychological benefits to their owners, they are a potential source of zoonotic infections, especially for vulnerable individuals such as immunocompromised patients. During 1 year, we therefore performed a pilot project, which included 32 immunocompromised Chilean children and their family pets (35 dogs and 9 cats) with the aim of detecting, treating and preventing zoonotic infections. Children were examined by Infectious Diseases paediatricians and demographical and clinical information related to zoonotic infections were recorded. Pets were examined and sampled by veterinarians, who also administered missing routine vaccines and anti-parasitics. During family visits, all members were informed and educated about zoonoses and a satisfaction survey was performed. Visits also included vector control and indoor residual spraying with pyrethroids. Children were re-examined and re-tested according to the findings of their pets, and all detected zoonotic infections were treated both in children and pets. Physical examination revealed abnormalities in 18 dogs (51.4%) and three cats (33.3%). Twenty-eight (63.6%) of the pets were diagnosed with a zoonotic pathogen, and seven (15.9%) with a facultative pathogen. Most zoonotic agents were isolated from the pet's external ear and intestine. Bacteria with the highest pathogenic potential were Campylobacter jejuni and Brucella canis. In two children and their respective pets, the same zoonotic diseases were diagnosed (toxocariasis and giardiasis). Arthropods serving as potential vectors of zoonotic infections were found in 49% of dogs and 44% of cats. The pilot project was positively evaluated by the participating families. Our pilot project confirmed that pets are reservoir for various zoonotic agents in Chile and that the implementation of an integrated multidisciplinary programme was a valuable tool to prevent, diagnose and treat such zoonotic infections in vulnerable patients such as immunocompromised children.

Posttraumatic Growth in Widowed and Non-widowed Older Adults: Religiosity and Sense of Coherence

Older people may experience psychological growth following a life major event. The objective of this study is to analyze the degree of posttraumatic growth (PTG) developed by widowed and non-widowed older adults (n = 103) as well as the impact of possible predicting variables such as sociodemographic characteristics, experienced or witnessed life major events, religiosity and sense of coherence. The findings suggest that, in spite of widowhood, elder people develop PTG in the same way that non-widowed elder people. Therefore, the support of a religious community, age, life major events experienced and the subjective meaning given to them correlated with PTG.

The rise of ampicillin-resistant Enterococcus faecium high-risk clones as a frequent intestinal colonizer in oncohaematological neutropenic patients on levofloxacin prophylaxis: a risk for bacteraemia?

Levofloxacin extended prophylaxis (LEP), recommended in oncohaematological neutropenic patients to reduce infections, might select resistant bacteria in the intestine acting as a source of endogenous infection. In a prospective observational study we evaluated intestinal emergence and persistence of ampicillin-resistant Enterococcus faecium (AREfm), a marker of hospital adapted high-risk clones. AREfm was recovered from the faeces of 52 patients with prolonged neutropenia after chemotherapy, at admission (Basal), during LEP, and twice weekly until discharge (Pos-LEP). Antibiotic susceptibility, virulence traits and population structure (pulsed-field gel electrophoresis and multilocus sequence typing) were determined and compared with bacteraemic isolates. Gut enterococcal population was monitored using a quantitative PCR quantification approach. AREfm colonized 61.4% of patients (194/482 faecal samples). Sequential AREfm acquisition (25% Basal, 36.5% LEP, 50% Pos-LEP) and high persistent colonization rates (76.9-89.5%) associated with a decrease in clonal diversity were demonstrated. Isolates were clustered into 24 PFGE-patterns within 13 sequence types, 95.8% of them belonging to hospital-associated Bayesian analysis of population structure subgroups 2.1a and 3.3a. Levofloxacin resistance and high-level streptomycin resistance were a common trait of these high-risk clones. AREfm-ST117, the most persistent clone, was dominant (60.0% isolates, 32.6% patients). It presented esp gene and caused 18.2% of all bacteraemia episodes in 21% of patients previously colonized by this clone. In AREfm-colonized patients, intestinal enrichment in the E. faecium population with a decline in total bacterial load was observed. AREfm intestinal colonization increases during hospital stay and coincides with enterococci population enrichment in the gut. Dominance and intestinal persistence of the ST117 clone might increase the risk of bacteraemia.

[Factors determining patient satisfaction with the pre-anaesthesia consultation]

OBJECTIVE

To analyse patient satisfaction with care provided in the pre-anaesthetic consultation and its determining factors.

MATERIAL AND METHOD

An anonymous questionnaire was randomly distributed to patients attending a pre-anaesthesia clinic, which included 4 questions with 5 possible answers on a (very dissatisfied, dissatisfied, fairly satisfied, satisfied and very satisfied) categorical graduated scale related to punctuality, understanding of the information received, respectful treatment, and overall satisfaction. The fifth question was about the knowledge or the name of the anaesthesiologist who attended them. A binary logistic regression model was used, which identified the predictors of satisfaction, calculated the odds ratios, and their respective 95% confidence intervals.

RESULTS

A total of 4006 questionnaires were analysed, in which 99.2% (3966) of users rated as satisfied/very satisfied the question about the respectful treatment, 98.4% (3937) of the information received and understanding, 77.4% (3096) punctuality in attending, and 97, 6% (3909) overall satisfaction. Almost three-quarters (71%, 2844) did not know the name of the anaesthesiologist. Regression analysis associated the more satisfied with their treatment (OR 17.44; P<.0005) and the information received (OR 14.94, P<.0005), while punctuality (OR 5 40; P<.0005) was the factor that contributed less to the result.

CONCLUSION

In our population satisfaction in pre-anaesthesia consultation is due mainly to the communication skills of the anaesthesiologist.

Effect of preoperative oral pravastatin reload in systemic inflammatory response and myocardial damage after coronary artery bypass grafting. A pilot double-blind placebo-controlled study

AIM

Statins exert pleiotropic effects that result in cardioprotective and antiinflammatory properties. There is a lack of information about the effect of preoperative reloading statin administration in surgical coronary patients regarding myocardial protection, systemic inflammatory response (SIR) attenuation and nitric oxide (NO) metabolism.

METHODS

Thirty consecutive dyslipidemic patients under chronic treatment with statins were randomized to orally receive pravastatin 80 mg (N.=10), 40 mg (N.=10) or placebo (N.=10) two hours before anesthetic induction for non-emergent on-pump coronary artery bypass grafting (CABG) procedures. Perioperative peripheral venous and intraoperative CS blood samples were collected for determination of drug-related adverse effects, NO metabolism and both myocardial damage and SIR biomarkers.

RESULTS

Pravastatin reloading resulted in a significant and dose-related intense attenuation of SIR, but no differences in cardiac damage biomarker levels were demonstrated. NO release and inducible nitric oxide synthase expression was significantly reduced in both treatment groups. Highest pravastatin doses significantly increased systemic creatine phosphokinase (CPK) concentration compared with intermediate doses but no other adverse effects were observed.

CONCLUSION

Oral pravastatin reloading before non-emergent CABG significantly attenuates postoperative SIR and systemic NO/iNOS concentrations with no effect in perioperative myocardial damage. Highest pravastatin doses increase CPK levels and must be avoided in susceptible patients.

Functional patterns of cytomegalovirus (CMV) pp65 and immediate early-1-specific CD8(+) T cells that are associated with protection from and control of CMV DNAemia after allogeneic stem cell transplantation

BACKGROUND

The functional profile of cytomegalovirus (CMV)-specific CD8(+) T cells that associate with protection from and control of CMV DNAemia in allogeneic stem cell transplant (allo-SCT) recipients remains incompletely characterized.

METHODS

We enumerated pp65 and immediate early (IE)-1-specific CD8(+) T cells expressing interferon-gamma, tumor necrosis factor-alpha, and CD107a, by flow cytometry in 94 patients at days +30 and +60 after allo-SCT.

RESULTS

Fifty of 94 patients had CMV DNAemia within the first 100 days after transplant. CMV-specific CD8(+) T-cell responses (of any functional type) were more likely to be detected in patients who did not display CMV DNAemia than in those who did (P = 0.04). Qualitatively, no major differences in the functional signature of CMV-specific CD8(+) T cells were noted between patients who had or did not have CMV DNAemia. Patients displaying levels of polyfunctional CD8(+) T cells at day +30 >0.30 cell/μL had a lower risk of CMV DNAemia (positive predictive value 76%, and negative predictive value 43%).

CONCLUSION

The presence of polyfunctional CD8(+) T cells (either expressing CD107a or not) was associated with lower levels of CMV replication, and higher frequency of self-resolved episodes. The data reported further clarify the role of polyfunctional CD8(+) T cells in control of CMV DNAemia in allo-SCT recipients.

Anger and health in dementia caregivers: exploring the mediation effect of optimism

Although previous studies indicate a negative association between caregivers' anger and health, the potential mechanisms linking this relationship are not yet fully understood. The aim of this study was to explore the potential mediating role of optimism in the relationship between anger and caregivers' physical health. Dementia caregivers (n = 108) were interviewed and filled out instruments assessing their anger (reaction), optimism and health (vitality). A mediational model was tested to determine whether optimism partially mediated the relationship between anger and vitality. Angry reaction was negatively associated with optimism and vitality; optimism was positively associated with vitality. Finally, the relationship between angry reaction and vitality decreased when optimism was entered simultaneously. A non-parametric bootstrap approach confirmed that optimism significantly mediated some of the relationship between angry reaction and vitality. These findings suggest that low optimism may help explain the association between caregivers' anger and reduced sense of vitality. The results provide a specific target for intervention with caregivers.

Polimorfismos de los genes CAPN1, CAST, DES, PRKAG3 Y RYR1 asociados a la capacidad de retención de agua en crudo y cocinado en carne de bovino en cruces Bos indicus y Bos taurus en Colombia

La capacidad de retención de agua (CRA) es uno de los parámetros de calidad de la carne más importante, dado que posee asociación con la percepción de jugosidad y la pérdida de peso de la pieza cárnica durante procedimientos como la maduración, la cocción y otro tipo de procesamiento tecnológico. La CRA en crudo y cocinado (CRAr y CRAc respectivamente) fue evaluada en 164 machos castrados cruzados, en los cuales se realizó la genotipificación de 23 regiones genómicas de los genes CAPN1, CAST, DES, PRKAG3 y RYR1. El marcador CAST2959 presentó asociación con el parámetro CRAr en el músculo Longissimus dorsi (LD) siendo el genotipo AA el de mejor comportamiento. El marcador RYR1-11195 se encontró asociado con el parámetro CRAc en LD, siendo la carne de animales con los genotipos GG y GA, la de mayor pérdida de peso, si son comparados con carne proveniente de animales con genotipo AA. Lo anterior permite establecer estos marcadores como posibles polimorfismos de importancia en procesos de selección y mejoramiento animal de este parámetro de calidad cárnica (CRAr y CRAc) en bovinos, posterior a un proceso de validación.

Main sugar composition of floral nectar in three species groups of Scrophularia (Scrophulariaceae) with different principal pollinators

In some angiosperm groups, a parallelism between nectar traits and pollination syndromes has been demonstrated, whereas in others there is not such relationship and it has been explained as due to phylogenetic constraints. However, nectar trait information remains scarce for many plant groups. This paper focuses on three groups of Scrophularia species, with different flower sizes and principal pollinators, to find out whether nectar sugar composition is determined by pollinator type or reflects taxonomic affinities. Since the species we examined have protogynous flowers, and gender bias in nectar sugar composition has been noted in few plant groups, we also investigated whether sexual phase influenced Scrophularia nectar composition. The sugar composition was found to be similar in all species, having high-sucrose nectar, except for the Macaronesian Scrophularia calliantha, which was the only species with balanced nectar; this last kind of nectar could be associated with the high interaction rates observed between S. calliantha and passerine birds. The nectar sugar composition (high in sucrose) was unrelated to the principal pollinator group, and could instead be considered a conservative taxonomic trait. No gender bias was observed between functionally female and male flowers for nectar volume or concentration. However, sexual phase significantly affected sucrose percentage in the largest-flowered species, where the female phase flowers had higher sucrose percentages than the male phase flowers.

[Vascular rings, our experience with 18 cases]

AIM

Vascular rings are a rare cause of compression of the trachea and/or the esophagus, causing stridor and/or severe dysphagia. We present our experience in the diagnosis and management of vascular rings.

METHODS

Retrospective study in which we analyzed clinical history, diagnosis and management of 18 patients diagnosed with vascular ring between January 1985 and December 2013. We evaluate endoscopy as a diagnostic method.

RESULTS

A total of 18 patients were included, with a median age of 2 years. 83.3% (15/18) had some type of symptom: 46.7% (7/15) had respiratory symptoms such as respiratory distress, stridor, recurrent respiratory infections, bronchospasm with wheezing or asthma in older children; 20% (3/15) had digestive symptoms such as dysphagia, vomiting and regurgitation; and 33.3% (5/15) combined respiratory and digestive symptoms. The remaining patients, 16.7% (3/18) were asymptomatic and the diagnosis was casual. The most common types of vascular rings were double aortic arch (27.8%) and aberrant subclavian right artery (27.8%). In 3 cases (16.7%) a Kommerell diverticulum was associated. 44.4% (n = 8) was operated on, the remaining did not present symp- toms which justify the intervention (n = 10). 37.5% of patients had postoperative complications (iatrogenic recurrent paralysis and persistent tracheomalacia). There was no mortality in our series. The median follow-up was 6.4 years. At the moment, 88.9% of patients are asymptomatic, and 33.3% have been definitely discharged.

CONCLUSIONS

Vascular rings are rare, and usually presented with common symptoms in childhood. Therefore, in front of a longstanding and recurrent respiratory symptoms, or dysphagia, we should think of a vascular ring. Not all subjects are candidates for surgical correction; therefore a multidisciplinary evaluation is essential.