Chitosan scaffolds with mesoporous hydroxyapatite and mesoporous bioactive glass.

Bone regeneration is one of the most well-known fields in tissue regeneration. The major focus concerns polymeric/ceramic composite scaffolds. In this work, several composite scaffolds based on chitosan (CH), with low and high molecular weights, and different concentrations of ceramics like mesoporous bioactive glass (MBG), mesoporous hydroxyapatite (MHAp) and both MBG and MHAp (MC) were produced by lyophilization. The purpose is to identify the best combination regarding optimal morphology and properties. The tests of the scaffolds present a highly porous structure with interconnected pores. The compression modulus increases with ceramic concentration in the scaffolds. Furthermore, the 75%MBG (835 ± 160 kPa) and 50%MC (1070 ± 205 kPa) samples are the ones that mostly enhance increases in mechanical properties. The swelling capacity increases with MBG and MC, respectively, to 700% and 900% and decreases to 400% when MHAp concentration increases. All scaffolds are non-cytotoxic at 12.5 mg/mL. The CHL scaffolds improve cell adhesion and proliferation compared to CHH, and the MC scaffold samples, show better results than those produced with just MBG or MHAp. The composite scaffolds of chitosan with MBG and MHAp, have revealed to be the best combination due to their enhanced performance in bone tissue engineering.

Early analysis shows that endoscopic flexor hallucis longus transfer has a promising cost-effectiveness profile in the treatment of acute Achilles tendon ruptures.

PURPOSE: Current options for treating an Achilles tendon rupture (ATR) include conservative and surgical approaches. Endoscopic flexor hallucis longus (FHL) transfer has been recently proposed to treat acute ruptures, but its cost-effectiveness potential remains to be evaluated. Therefore, the objective of this study was to perform an early cost-effectiveness analysis of endoscopic FHL transfer for acute ATRs, comparing the costs and benefits of current treatments from a societal perspective. METHODS: A conceptual model was created, with a decision tree, to outline the main health events during the treatment of an acute ATR. The model was parameterized using secondary data. A systematic review of the literature was conducted to gather information on the outcomes of current treatments. Data related to outcomes of endoscopic FHL transfers in acute Achilles ruptures was obtained from a single prospective study. Analysis was limited to the two first years. The incremental cost-effectiveness ratio was the main outcome used to determine the preferred strategy. A willingness-to-pay threshold of $100,000 per quality-adjusted life-year was used. Sensitivity analyses were performed to determine whether changes in input parameters would cause significant deviation from the reference case results. Specifically, a probability sensitivity analysis was conducted using Monte Carlo simulations, and a one-way sensitivity analysis was conducted by sequentially varying each model parameter within a given range. RESULTS: For the reference case, incremental cost-effectiveness ratios exceeded the willingness-to-pay threshold for all the surgical approaches. Overall, primary treatment was the main cost driver. Conservative treatment showed the highest direct costs related to the treatment of complications. In the probabilistic sensitivity analysis, at a willingness-to-pay threshold of $100,000, open surgery was cost-effective in 50.9%, minimally invasive surgery in 55.8%, and endoscopic FHL transfer in 72% of the iterations. The model was most sensitive to parameters related to treatment utilities, followed by the costs of primary treatments. CONCLUSION: Surgical treatments have a moderate likelihood of being cost-effective at a willingness-to-pay threshold of $100,000, with endoscopic FHL transfer showing the highest likelihood. Following injury, interventions to improve health-related quality of life may be better suited for improved cost-effectiveness. LEVEL OF EVIDENCE: Level III.

Mechanical performance and bioactivation of 3D-printed PEEK for high-performance implant manufacture: a review.

Polyetheretherketone (PEEK) has stood out as the leading high-performance thermoplastic for the replacement of metals in orthopaedic, trauma and spinal implant applications due to its high biocompatibility and mechanical properties. Despite its potential for custom-made medical devices, 3D-printed PEEK's mechanical performance depends on processing parameters and its bioinertness may hinder bone opposition to the implant. Concerning these challenges, this review focuses on the available literature addressing the improvement of the mechanical performance of PEEK processed through "fused filament fabrication" (FFF) along with literature on bioactivation of PEEK for improved osseointegration. The reviewed research suggests that improvements can be achieved in mechanical performance of 3D-printed PEEK with adequate FFF parametrization while different bioactivation techniques can be used to improve the bioperformance of 3D-printed PEEK. The adequate approaches towards these procedures can increase PEEK's potential for the manufacture of high-performance custom-made implantable devices that display improved bone-implant integration and prevent stress shielding of the treated bone.

Early cost estimating model for new bioabsorbable orthopedic implant candidates: A theoretical study.

An early health technology assessment (HTA) study was performed to assess the need for developing a new bioabsorbable implant for the treatment of specific orthopedic injuries. The Anterior Cruciate Ligament Reconstruction (ACLR) procedure was selected based on the need and potential impact of bioabsorbable implants in the treatment of ACL injuries. The economic model considers the possible health events after an ACLR (failures and other complications such as stiffness and pain). A decision tree approach was used, and several sensitivity analyses were performed using a Monte Carlo simulation. A cost estimating model was applied comparatively for currently available metal and bioabsorbable implants against a potential new bioabsorbable implant with improved performance. A reduction in stiffness and pain symptoms were considered as targets for these new implants performance, with reduced inflammation resulting from the use of materials with appropriate biological and mechanical properties. The current study estimates that, under the assumptions made, the introduction of a new bioabsorbable implant in ACLR surgeries may generate yearly cost savings. The model estimates positive cost-benefits of the new implant when it reduces the probability of failure by more than 30%, or reduces at least 14% the probability of complications of an inflammatory nature. The development of a new bioabsorbable orthopedic implant for ACLR is encouraged by this study identifying the need for new bioabsorbable implants with improved biological and mechanical performance. The results of this early HTA have made it possible to anticipate design needs and objectives for the research and development of new orthopedic bioabsorbable implants.

Influence of strain rate on the mechanical behavior of dry and hydrated chitosan-based dense materials for bioabsorbable implant applications.

Chitosan has generated enormous interest in the scientific community because of its distinctive biological and physicochemical properties, which allow new advanced structures and applications. Porous chitosan scaffolds have been extensively studied and explored in bone generation, however it is still a challenge to obtain bioabsorbable orthopedic implants that involves pure 3D dense chitosan geometries due to the inherent difficulties in producing and shaping such structures. In this work, chitosan was blended with 10% glycerol and 10% glycerol + 10% biphasic mixture of calcium phosphate (70% hydroxyapatite with 30% ß-tricalcium phosphate) to produce dense chitosan-based blocks, which were then shaped into rods. The introduction of plasticizer aimed to improve the materials ductility while the ceramic particles were used to increase stiffness and strength. The mechanical behavior of the two chitosan-based compositions was evaluated by uniaxial compression tests using a customized split-Hopkinson pressure bar (SHPB). The specimens were analysed in quasi-static conditions (less than 0.1 s-1) and medium strain rate conditions (200-800 s-1), both in dry state and in different hydrated conditions, in the latter case to approximate the in vivo implant conditions. The results showed promising results for the intended application. The chitosan blends present excellent ductility with an elastic perfect-plastic behavior in quasi-static conditions, with yield stresses around 40 MPa for the dry state, with a decay for 3 MPa after 48h hydration. An empirical model was proposed to describe the flow stress curves, with a good agreement with the experimental data, allowing future modelling of this material behavior.

Long-term refractive outcomes in children with early diagnosis of moderate to high hyperopia.

PURPOSE: The purpose of this study was to investigate the long-term outcome of moderate-to-high hyperopic refractive errors in childhood. METHODS: We reviewed medical records from children diagnosed with hyperopia (≥3D) in the amblyogenic risk factors screening that is performed in a public hospital in Portugal. We included hyperopic children diagnosed between 2001 and 2011 with at least three available ophthalmologic evaluations (including one before the age of 3 years and one after a minimum period of 6 years after the first evaluation). Spherical equivalent (SE) was considered. RESULTS: In total, 78 eyes from 39 children met the inclusion criteria (49% male). Mean age at first and last evaluation was 1.8 ± 0.9 years and 10.6 ± 2.7 years, respectively. Median follow-up was 130 months (range 72-193). At baseline evaluation, the mean SE was 4.5 ± 1.4 diopters, 36% of children had a SE ≥5.0 diopters, 23% had partially accommodative esotropia, 26% had accommodative esotropia and 51% had no eye deviation. At the last evaluation, the mean SE was 4.6 ± 1.7diopters. During follow-up, four children developed unilateral amblyopia (one because of anisometropia, three because of anisometropia and strabismus). From these, three recovered with treatment. Until the age of 10 years, the number of children that presented with strabismus did not decrease. CONCLUSION: In our study, children with moderate to high hyperopia did not experience a significant reduction in the power of the refractive error. Although almost 50% of children had an initial deviation, only one had amblyopia at the end of follow-up. Implementing screening strategies for the early detection of this refractive error may prevent long-term vision morbidity in hyperopic children.

Strategy to improve the mechanical properties of bioabsorbable materials based on chitosan for orthopedic fixation applications.

Bioabsorbable polymeric fixation devices have been used as an alternative to metallic implants in orthopedics, preventing the stress shielding effect and avoiding a second surgery for implant removal. However, several problems are still associated with current bioabsorbable implants, including the limited mechanical stiffness and strength, and the adverse tissue reactions generated. To minimize or even eliminate the problems associated with these implants, strategies have been developed to synthesize new implant materials based on chitosan. To overcome the brittle behavior of most 3D chitosan-based structures, glycerol and sorbitol were blended to chitosan and the effect of these plasticizers in the produced specimens was analyzed by flexural tests, Berkovich tests, scanning electron microscopy (SEM) and micro-CT analyzes. The improvement of the mechanical properties was also tested by adding ceramics, namely hydroxyapatite powder and biphasic mixtures of hydroxyapatite (HA) and beta-tricalcium phosphate (ß-TCP). In the plasticizers group, the best combination of the measured properties was obtained for chitosan with 10% glycerol (flexural strength of 53.8 MPa and indentation hardness of 19.4 kgf/mm2), while in the ceramics group the best mechanical behavior was obtained for chitosan with 10% HA+ß-TCP powder (flexural strength of 67.5 MPa and indentation hardness 28.2 kgf/mm2). All the tested material compositions were dense and homogeneous, fundamental condition for a good implant performance. These are encouraging results, which support the continued development of chitosan-based materials for orthopedic fixation applications.

Chronic myeloid leukemia diagnosed in a patient with uncontrolled proliferative diabetic retinopathy.

PURPOSE: To report a case of uncontrolled proliferative diabetic retinopathy as an initial manifestation of chronic myeloid leukemia. METHODS: Case report. PATIENTS: A 55-year-old man with moderate nonproliferative diabetic retinopathy who rapidly developed proliferative retinopathy and bilateral neovascular glaucoma despite good glycemic control. CONCLUSION: Other pathologies should be excluded in diabetic patients with a rapid and severe progression in their retinopathy despite adequate metabolic control. These patients should be treated promptly and aggressively until systemic disease is stable.

Central retinal vein occlusion in a patient with retinal vasculitis and Crohn's disease.

The authors report a rare case of a 47-year-old woman with Crohn's disease (CD) who presented with retinal vasculitis and central retinal vein occlusion (CRVO) during remission. The patient complained of sudden painless visual loss in her left eye (OS). Ophthalmologic evaluation revealed a best corrected visual acuity (BCVA) of 20/20 in the right eye and hand movements in OS. Ophthalmoscopy and fluorescein angiography of OS showed signs of nonischemic CRVO and extensive vasculitis. She was treated with oral prednisolone, mercaptopurine, and intravitreal bevacizumab in OS. After 1 month of treatment, VA of OS improved to 5/10 and after 1 year it was 10/10 with complete resolution of retinal vasculitis and nonischemic CRVO.

Immune recovery uveitis masked as an endogenous endophthalmitis in a patient with active CMV retinitis.

Cytomegalovirus (CMV) retinitis may occur in profoundly immunocompromised patients and be the initial AIDS-defining infection. The incidence and prevalence of CMV retinitis has declined substantially in the era of highly active antiretroviral therapy (HAART); nevertheless, it remains a leading cause of ocular morbility. We report the case of a 40-year-old man with blurred vision and pain in the right eye, three weeks after the initiation of effective HAART treatment. Ocular examination revealed a panuveitis causing an anterior chamber reaction with hypopyon and a dense vitreous haze. An endogenous endophthalmitis was suspected and treatment was ensued, without improvement. A vitreous tap was performed, and a positive polymerase chain reaction for CMV was found. A diagnosis of immune recovery uveitis (IRU) was made, and the patient responded to treatment with valganciclovir and dexamethasone. IRU is an intraocular inflammation that develops in patients with HAART-induced immune recovery and inactive CMV retinitis, although cases of active CMV retinitis have been described. Presentation with panuveitis and hypopion is rare and may be misleading regarding diagnosis and management.

First report of an accident with the speckled forest pit viper (Bothriopsis taeniata) in Brazil.

The first reported case of an accident with Bothriopsis taeniata in Brazil is described. The victim, a 43-year-old man, was bitten just above his right heel and presented a clinical condition compatible with mild Bothrops poisoning: local edema with hemorrhage at the bite site and pain, although without coagulopathy.

Risk factors of oropharyngeal carriage of Pseudomonas aeruginosa among patients from a Medical-Surgical Intensive Care Unit

Oropharyngeal carriage of Pseudomonas aeruginosa is associated with increased risk of infection and may provide a source for spread of drug-resistant strains. In order to assess the incidence and risk factors of oropharyngeal carriage, we conducted a retrospective cohort study based on results of surveillance cultures (oropharyngeal swabs) from a medical-surgical intensive care unit, collected from March 2005 through May 2006. Variables investigated included demographic characteristics, comorbid conditions, invasive procedures, use of devices and use of antimicrobials. Thirty case patients with P. aeruginosa carriage were identified. Other 84 patients with surveillance cultures negative to P. aeruginosa were enrolled as control subjects. Case patients were more likely to have a solid malignancy (Odds Ratio [OR] = 12.04, 95 percent Confidence Interval [CI] = 1.93-75.09, p=0.008), Acquired Immunodeficiency Syndrome (AIDS, OR = 7.09, 95 percent CI= 1.11-45.39, p = 0.04), central nervous system disease (OR = 4.51, 95 percent CI = 1.52-13.39, p = 0.007), or to have a central venous catheter placed (OR = 7.76, 95 percent CI = 1.68-35.79, p=0.009). The use of quinolones was a protective factor (OR = 0.13, 95 percent CI = 0.03-0.47, p = 0.002). The predominance of comorbidities as risk factors points out a group of patients to whom preventive measures should be directed.

First report of an accident with the speckled forest pit viper (Bothriopsis taeniata) in Brazil / Primeiro registro de acidente pela jararaca estrela (Bothriopsis taeniata) no Brasil

The first reported case of an accident with Bothriopsis taeniata in Brazil is described. The victim, a 43-year-old man, was bitten just above his right heel and presented a clinical condition compatible with mild Bothrops poisoning: local edema with hemorrhage at the bite site and pain, although without coagulopathy.

Relatamos o primeiro caso de acidente por Bothriopsis taeniata no Brasil. A vítima, trabalhador rural com 43 anos de idade, foi picada pouco acima do calcanhar direito, apresentando quadro clínico compatível por envenenamento botrópico leve: discreto edema com hemorragia no local da picada e dor, embora com ausência de coagulopatia.

Risk factors of oropharyngeal carriage of Pseudomonas aeruginosa among patients from a Medical-Surgical Intensive Care Unit.

Oropharyngeal carriage of Pseudomonas aeruginosa is associated with increased risk of infection and may provide a source for spread of drug-resistant strains. In order to assess the incidence and risk factors of oropharyngeal carriage, we conducted a retrospective cohort study based on results of surveillance cultures (oropharyngeal swabs) from a medical-surgical intensive care unit, collected from March 2005 through May 2006. Variables investigated included demographic characteristics, comorbid conditions, invasive procedures, use of devices and use of antimicrobials. Thirty case patients with P. aeruginosa carriage were identified. Other 84 patients with surveillance cultures negative to P. aeruginosa were enrolled as control subjects. Case patients were more likely to have a solid malignancy (Odds Ratio [OR] = 12.04, 95% Confidence Interval [CI] = 1.93-75.09, p=0.008), Acquired Immunodeficiency Syndrome (AIDS, OR = 7.09, 95% CI= 1.11-45.39, p = 0.04), central nervous system disease (OR = 4.51, 95% CI = 1.52-13.39, p = 0.007), or to have a central venous catheter placed (OR = 7.76, 95% CI = 1.68-35.79, p=0.009). The use of quinolones was a protective factor (OR = 0.13, 95% CI = 0.03-0.47, p = 0.002). The predominance of comorbidities as risk factors points out a group of patients to whom preventive measures should be directed.

Carcterizaçao familiar de alunas de psicologia através do genetograma

Este trabalho teve por objetivo caracterizar a estrutura familiar de 32 alunas do curso de Psicologia através da técnica do Genetograma ou Genograma. A análise dos resultados procurou caracterizar e descrever os dados demográficos mapeados pelas alunas de Psicologia, explorando a estrutura familiar como também alguns aspectos do funcionamento familiar. Os dados obtidos nos permitiram chegar aos seguintes resultados: predominou o tipo de familia nuclear, mostrando, porém, o incremento de novas organizações familiares; o estágio do ciclo de vida familiar que caracterizou predominantemente as familias foi o denominado 'lançando os filhos'; a maior parte das jovens estudantes continua morando com suas famílias, o que mostra como, cada vez mais, o jovem adulto está permanecendo em casa e, consequentemente, o desenpenho das funções parentais ainda é bastante evidente; o tamanho das familias tendeu a diminuir, confirmando estatísticas nacionais nesse sentido; as jovens que se diferenciaram das familias o fizeram através do casamento; as mulheres ( mães e avós) apresentaram maior expectativa de vida que os homens; houve uma tendência a um envolvimento positivo das alunas com os pais e familiares de origem matena e o funcionamento familiar tendeu a a ser do tipo emaranhado (AU)