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This review showcases a comprehensive analysis of studies that highlight the different conversion procedures attempted across the globe. The resources of biogas production along with treatment methods are presented. The effect of different governing parameters like feedstock types, pretreatment approaches, process development, and yield to enhance the biogas productivity is highlighted. Biogas applications, for example, in heating, electricity production, and transportation with their global share based on national and international statistics are emphasized. Reviewing the world research progress in the past 10 years shows an increase of ~ 90% in biogas industry (120 GW in 2019 compared to 65 GW in 2010). Europe (e.g., in 2017) contributed to over 70% of the world biogas generation representing 64 TWh. Finally, different regulations that manage the biogas market are presented. Management of biogas market includes the processes of exploration, production, treatment, and environmental impact assessment, till the marketing and safe disposal of wastes associated with biogas handling. A brief overview of some safety rules and proposed policy based on the world regulations is provided. The effect of these regulations and policies on marketing and promoting biogas is highlighted for different countries. The results from such studies show that Europe has the highest promotion rate, while nowadays in China and India the consumption rate is maximum as a result of applying up-to-date policies and procedures.
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BackgroundPrebiotics and probiotics (synbiotics) can modify gut microbiota and have potential in allergy management when combined with amino-acid-based formula (AAF) for infants with cow's milk allergy (CMA).MethodsThis multicenter, double-blind, randomized controlled trial investigated the effects of an AAF-including synbiotic blend on percentages of bifidobacteria and Eubacterium rectale/Clostridium coccoides group (ER/CC) in feces from infants with suspected non-IgE-mediated CMA. Feces from age-matched healthy breastfed infants were used as reference (healthy breastfed reference (HBR)) for primary outcomes. The CMA subjects were randomized and received test or control formula for 8 weeks. Test formula was a hypoallergenic, nutritionally complete AAF including a prebiotic blend of fructo-oligosaccharides and the probiotic strain Bifidobacterium breve M-16V. Control formula was AAF without synbiotics.ResultsA total of 35 (test) and 36 (control) subjects were randomized; HBR included 51 infants. At week 8, the median percentage of bifidobacteria was higher in the test group than in the control group (35.4% vs. 9.7%, respectively; P<0.001), whereas ER/CC was lower (9.5% vs. 24.2%, respectively; P<0.001). HBR levels of bifidobacteria and ER/CC were 55% and 6.5%, respectively.ConclusionAAF including specific synbiotics, which results in levels of bifidobacteria and ER/CC approximating levels in the HBR group, improves the fecal microbiota of infants with suspected non-IgE-mediated CMA.
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Aminoácidos/química , Microbioma Gastrointestinal , Fórmulas Infantiles , Hipersensibilidad a la Leche/terapia , Simbióticos , Animales , Bovinos , Clostridium , Método Doble Ciego , Eubacterium , Femenino , Humanos , Inmunoglobulina E , Lactante , Masculino , Leche , Hipersensibilidad a la Leche/inmunología , Resultado del TratamientoRESUMEN
Increasing emphasis on the use of molecular tests in a histocompatibility and immunogenetics laboratory (HIL) poses a potential problem of lack of sufficient DNA to perform multiple genetic analyses. In this study, we report the feasibility, fidelity and utility of multiple displacement amplification (MDA) method to perform whole-genome amplification (WGA) to generate DNA specimens that can be analyzed by multiple molecular techniques and can be used for different clinical tests offered by an HIL. The MDA-generated DNA when compared with the native DNA showed 100% congruency in genotyping of 37 genes/loci using multiple downstream molecular techniques: sequence-based typing and sequence-specific primer-based typing for 5 human leukocyte antigen (HLA) class I and II genes (HLA-A, B, C, DRB1 and DQB1), luminex-based sequence-specific oligonucleotide (SSO) genotyping for a panel of 16 killer immunoglobulin-like receptor (KIR) genes and automated fragment size analysis for a panel of 15 short tandem repeat (STR) loci and amelogenin gene. For post-allogeneic hematopoietic cell transplantation (HCT) chimerism analysis, MDA-generated DNA appeared useful for enriching pre-transplant DNA but not for enriching post-transplant chimeric DNA. Overall, our results show that MDA-based WGA could generate DNA of high yield and fidelity that can be used for various clinical tests and research purposes.
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Dermatoglifia del ADN/métodos , ADN/análisis , Genoma Humano , Técnicas de Amplificación de Ácido Nucleico/métodos , Amelogenina/genética , Amelogenina/inmunología , ADN/genética , Cartilla de ADN , Perfilación de la Expresión Génica , Sitios Genéticos , Estudio de Asociación del Genoma Completo , Antígenos HLA/genética , Antígenos HLA/inmunología , Trasplante de Células Madre Hematopoyéticas , Prueba de Histocompatibilidad , Humanos , Técnicas de Amplificación de Ácido Nucleico/estadística & datos numéricos , Receptores KIR/genética , Receptores KIR/inmunología , Análisis de Secuencia de ADN , Secuencias Repetidas en Tándem , Trasplante HomólogoRESUMEN
BACKGROUND: Previous reports indicate that patients with Parkinson's disease (PD) activate the prefrontal cortex (PFC) during complex activities such as obstacle negotiation to compensate for impaired motor function. However, the influence of disease severity on PFC activation has not been systematically evaluated. Here, we examined the effects of disease severity on PFC activation during obstacle negotiation. METHODS: 74 patients with PD (age 68.26 ± 7.54 yrs; 62.2% men) were divided into three groups based on Hoehn and Yahr stages. All patients walked along an obstacle course while negotiating anticipated and unanticipated obstacles (long/low available response time) at heights of 50 mm and 100 mm. PFC activation was measured using functional near-infrared spectroscopy (fNIRS) and was compared between groups and tasks using mixed model analyses. RESULTS: Participants with more advanced PD (i.e., Hoehn & Yahr 3) had higher PFC activation levels when negotiating anticipated obstacles, compared to participants with milder PD (i.e., Hoehn & Yahr 1, 2) (p < 0.001). Moreover, higher LEDD correlated with higher prefrontal activation during the higher anticipated obstacle. In contrast, during the negotiation of unanticipated obstacles, the differences in PFC activation were not associated with disease severity in a linear manner. CONCLUSIONS: The present study suggests that with increased disease severity, patients with PD rely more on the PFC when negotiating anticipated obstacles, perhaps to compensate for attention and motor deficits. These findings support the role of cognition in fall risk and the need to improve attention and cognition in fall prevention programs, especially among patients with more advanced disease.
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Enfermedad de Parkinson , Anciano , Femenino , Marcha/fisiología , Humanos , Masculino , Persona de Mediana Edad , Negociación , Enfermedad de Parkinson/complicaciones , Corteza Prefrontal/diagnóstico por imagen , Índice de Severidad de la Enfermedad , Caminata/fisiologíaRESUMEN
Background One of the vital tools in diagnosing a variety of medical conditions is through radiological examinations which can lead to severe biological effects if precautions are not taken. To limit the harmful effects, as low as reasonably achievable (ALARA) was implemented. ALARA aims to minimize the time, increase the distance, and promote the use of protective shielding. Method The cross-sectional study included 454 physicians in King Abdulaziz Medical City (KAMC) and King Abdullah Specialist Children's Hospital (KASCH), Riyadh, Saudi Arabia. The study assessed physicians' knowledge and awareness about the hazards of radiological examinations on their patients' health using a self-administered questionnaire to measure knowledge, attitude, and practice (KAP). KAP was compared with the sociodemographic characteristics using the Mann-Whitney Z-test as well as Kruskal Wallis H-test. Results Out of 454 physicians, males exceeded the females (61.7% vs 38.3%) with nearly three-quarters (72.5%) working in King Abdulaziz Medical City. The most commonly mentioned specialty was internal medicine, while the least common specialty was orthopedics. Based on a cutoff point of 60%, it was revealed that poor knowledge was observed in 70.5% of physicians. With regards to attitude, 65.2% of physicians had a positive attitude. For practices, 49.8% had poor practices while 50.2% had good practices. The mean scores for knowledge, attitude and practice were 9.19 (SD 7.03) out of 23 points, 1.89 (SD 1.06) out of 3 points, and 5.43 (SD 1.67) out of 8 points, respectively. Conclusion In conclusion, poor knowledge, practice, and positive attitude were detected among physicians. However, our study was limited by the use of a self-administered online questionnaire.
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BACKGROUND: Petroclival meningiomas (PCM) are challenging tumors to manage. Observation, Stereotactic radiosurgery (SRS) and surgical resection have typically been offered as treatment options. A percentage of patients with PCMs present with trigeminal pain. We present four patients with small PCMs presenting with Trigeminal neuralgia (TN) that were treated with radiosurgery and continued to have debilitating trigeminal pain afterwards. All of them underwent microsurgical resection (MR) of their tumor to manage their trigeminal pain. OBJECTIVE: Trigeminal Neuralgia in the setting of PCM is rare. Oftentimes in these subset of patients TN pain persists after radiation and medical therapy. We explore the possibility of addressing intractable TN pain with microsurgical resection. METHODS: Patients with petroclival meningiomas presenting with trigeminal pain and having persistent pain after treatment with radiosurgery were included in our review. Those patients were treated with microsurgical resection of their tumor to help control their persistent pain. The patients' demographics, clinical, and radiological data were reviewed. The primary aim of the review was to assess the patients' Barrow Neurological Institute (BNI) trigeminal neuralgia scores following microsurgical resection. RESULTS: Four female patients were identified. The tumors were locally controlled after SRS, however all four patients continued to have debilitating trigeminal pain despite medical management. All patients had complete resolution of their TN pain in the immediate postoperative period, with a BNI score of I on their last follow up. CONCLUSION: Microsurgical resection is an appropriate option for patient's petroclival meningiomas with persistent facial pain after treatment with SRS.
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Neoplasias Meníngeas/cirugía , Meningioma/cirugía , Microcirugia , Procedimientos Neuroquirúrgicos , Neuralgia del Trigémino/cirugía , Anciano , Fosa Craneal Posterior , Femenino , Humanos , Neoplasias Meníngeas/complicaciones , Neoplasias Meníngeas/radioterapia , Meningioma/complicaciones , Meningioma/radioterapia , Persona de Mediana Edad , Hueso Petroso , Radiocirugia , Reoperación , Neuralgia del Trigémino/etiologíaRESUMEN
PURPOSE: To study the efficacy, stability, safety and predictability of small incision lenticule extraction (SMILE) at 1 day and 3 months postoperatively for moderate and high myopic astigmatism. To describe a simple and convenient method for detection and manual compensation of cyclotorsion during the procedure. METHODS: In this retrospective study, a total of 164 eyes from 114 patients over 20 years of age with at least 1.5 diopters (D) of myopic astigmatism were treated by SMILE. Any cyclotorsion was manually compensated by gently rotating the cone to align the horizontal marks on the cornea to the 0° to 180° axis of the reticule after activating the suction. RESULTS: The mean preoperative spherical equivalent (SE) was -5.3±2.01 D, and the mean cylinder was -2.01±0.67 D. Three months after surgery, a total of 87% of eyes were within±0.50 D of attempted post-operative SE, and 98% of eyes were within±1.00 D. Overall, the predictability of cylinder correction was excellent, with 96.3% of eyes within±1.00 D of attempted post-operative cylinder. The mean postoperative cylinder at three months was -0.3±0.39 D. We noted a slight undercorrection with treatment of high cylinder. However, 82% of eyes achieved postoperative refractive astigmatism less than 0.5 D. 91% of eyes achieved uncorrected distance visual acuity (UDVA) equal to or better than 8/10. 22% of eyes gained one line of visual acuity. CONCLUSION: SMILE is a predictable and safe technique for the surgical correction of astigmatism. Manual compensation may be an effective approach to improve astigmatic outcomes of SMILE, especially in moderate and high astigmatism.
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Astigmatismo , Cirugía Laser de Córnea , Miopía , Astigmatismo/cirugía , Sustancia Propia , Humanos , Láseres de Excímeros , Miopía/diagnóstico , Miopía/cirugía , Refracción Ocular , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
The Impact Assessment (IA) step in Life Cycle Assessment (LCA) studies is classified into three steps of characterization, normalization and weighting. In this research, various impact categories were weighted using Analytic Hierarchy Process (AHP), as a multi criteria decision making tool. Iranian tobacco production system was the example of agricultural system. The data for LCA analysis were collected from 225 farms. The data for AHP analysis were gathered by surveying 12 LCA experts. The results indicated that on-farm emissions of CO2, CH4, N2O, NH3, NOx and SO2 were accounted for 25, 96, 93, 99, 21 and 2% of the total emissions (cradle to farm gate), respectively. The characterization indices for the impact categories of acidification, terrestrial eutrophication, global warming, phosphate resources depletion, potash resources depletion and fossil resources depletion for one ton tobacco production were calculated to be 13.87 kgSO2eq, 19.69 kgNOxeq, 1883.90 kgCO2eq, 19.69 kgNOxeq, 4.19 kgP2O5, 6.14 kgK2O, and 59,659.23 MJ, respectively. The LCAâ¯+â¯AHP showed that the weighted factors of global warming, terrestrial eutrophication, acidification, fossil resources depletion, phosphate resources depletion and potash resources depletion were 1, 0.790, 0.518, 0.681, 0.422, and 0.263, respectively. Many agricultural systems could benefit from using the developed weighting factors for LCA studies in the agricultural sector. Based on the new developed weighted factors, the weighted indices of aforementioned impact categories for Iranian tobacco production were 0.24, 0.41, 0.19, 1.04, 0.23, and 0.20, respectively. This implies that fossil resources depletion impact category was attributed the highest negative environmental impacts of tobacco production followed by terrestrial eutrophication.
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Agricultura , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Nicotiana/crecimiento & desarrollo , Eutrofización , Irán , Modelos TeóricosRESUMEN
BACKGROUND: Here we report follow-up data from a double-blind, randomized, controlled multicenter trial, which investigated fecal microbiota changes with a new amino acid-based formula (AAF) including synbiotics in infants with non-immunoglobulin E (IgE)-mediated cow's milk allergy (CMA). METHODS: Subjects were randomized to receive test product (AAF including fructo-oligosaccharides and Bifidobacterium breve M-16V) or control product (AAF) for 8 weeks, after which infants could continue study product until 26 weeks. Fecal percentages of bifidobacteria and Eubacterium rectale/Clostridium coccoides group (ER/CC) were assessed at 0, 8, 12, and 26 weeks. Additional endpoints included stool markers of gut immune status, clinical symptoms, and safety assessments including adverse events and medication use. RESULTS: The trial included 35 test subjects, 36 controls, and 51 in the healthy reference group. Study product was continued by 86% and 92% of test and control subjects between week 8-12, and by 71% and 80%, respectively until week 26. At week 26 median percentages of bifidobacteria were significantly higher in test than control [47.0% vs. 11.8% (p < 0.001)], whereas percentages of ER/CC were significantly lower [(13.7% vs. 23.6% (p = 0.003)]. Safety parameters were similar between groups. Interestingly use of dermatological medication and reported ear infections were lower in test versus control, p = 0.019 and 0.011, respectively. Baseline clinical symptoms and stool markers were mild (but persistent) and low, respectively. Symptoms reduced towards lowest score in both groups. CONCLUSION: Beneficial effects of this AAF including specific synbiotics on microbiota composition were observed over 26 weeks, and shown suitable for dietary management of infants with non-IgE-mediated CMA.Trial Registration NTR3979.
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BACKGROUND: Altered gut microbiota is implicated in cow's milk allergy (CMA) and differs markedly from healthy, breastfed infants. Infants who suffer from severe CMA often rely on cow's milk protein avoidance and, when breastfeeding is not possible, on specialised infant formulas such as amino-acid based formulas (AAF). Herein, we report the effects of an AAF including specific synbiotics on oral and gastrointestinal microbiota of infants with non-IgE mediated CMA with reference to healthy, breastfed infants. METHODS: In this prospective, randomized, double-blind controlled study, infants with suspected non-IgE mediated CMA received test or control formula. Test formula was AAF with synbiotics (prebiotic fructo-oligosaccharides and probiotic Bifidobacterium breve M-16V). Control formula was AAF without synbiotics. Healthy, breastfed infants were used as a separate reference group (HBR). Bacterial compositions of faecal and salivary samples were analysed by 16S rRNA-gene sequencing. Faecal analysis was complemented with the analysis of pH, short-chain fatty acids (SCFAs) and lactic acids. RESULTS: The trial included 35 test subjects, 36 controls, and 51 HBR. The 16S rRNA-gene sequencing revealed moderate effects of test formula on oral microbiota. In contrast, the gut microbiota was substantially affected across time comparing test with control. In both groups bacterial diversity increased over time but was characterised by a more gradual increment in test compared to control. Compositionally this reflected an enhancement of Bifidobacterium spp. and Veillonella sp. in the test group. In contrast, the control-fed infants showed increased abundance of adult-like species, mainly within the Lachnospiraceae family, as well as within the Ruminococcus and Alistipes genus. The effects on Bifidobacterium spp. and Lachnospiraceae spp. were previously confirmed through enumeration by fluorescent in situ hybridization and were shown for test to approximate the proportions observed in the HBR. Additionally, microbial activity was affected as evidenced by an increase of l-lactate, a decrease of valerate, and reduced concentrations of branched-chain SCFAs in test versus control. CONCLUSIONS: The AAF including specific synbiotics effectively modulates the gut microbiota and its metabolic activity in non-IgE mediated CMA infants bringing it close to a healthy breastfed profile.Trial registration Registered on 1 May 2013 with Netherlands Trial Register Number NTR3979.
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Non-obstetrical fetal head injury is an unusual clinical event. While multiple case reports describe motor vehicle collisions resulting in intrauterine fetal skull fractures, management of these injuries has not been emphasized. We report a case of a depressed fetal skull fracture with massive subgaleal and subperiosteal hemorrhage requiring neurosurgical intervention with good clinical outcomes for both mother and infant dyad.
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Craneotomía/métodos , Descompresión Quirúrgica/métodos , Sufrimiento Fetal/cirugía , Procedimientos de Cirugía Plástica/métodos , Lesiones Prenatales/cirugía , Fracturas Craneales/embriología , Accidentes de Tránsito , Adulto , Cesárea , Duramadre/cirugía , Femenino , Sufrimiento Fetal/diagnóstico por imagen , Sufrimiento Fetal/fisiopatología , Edad Gestacional , Humanos , Recién Nacido , Cuidado Intensivo Neonatal , Embarazo , Mujeres Embarazadas , Lesiones Prenatales/diagnóstico por imagen , Lesiones Prenatales/fisiopatología , Fracturas Craneales/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
OBJECTIVE: Human milk is the best form of nutrition for preterm infants and has been associated with a lower incidence of necrotizing enterocolitis (NEC). Infants that develop NEC have a higher incidence of feeding intolerance and longer hospitalizations. The combination of a donor milk bank and donor milk-derived fortifier has changed feeding practices in neonatal intensive care units (NICU). The purpose of this study is to assess the benefits and cost of an exclusive human milk (EHM) diet in very low birth weight (VLBW) infants in a community level III NICU. STUDY DESIGN: This is a retrospective study including preterm infants ⩽28 weeks and/or VLBW (⩽1500 g) who were enrolled from March 2009 until March 2014. Infants were grouped as follows: group H (entirely human milk based, born March 2012 to 2014), group B (bovine-based fortifier and maternal milk, born March 2009 to 2012), group M (mixed combination of maternal milk, bovine-based fortifier and formula, born March 2009 to 2012) and group F (formula fed infants, born March 2009 to 2012). Baseline characteristics among the four groups were similar. RESULT: The study included 293 infants between gestational ages 23 to 34 weeks and birth weights between 490 and 1700 g. Feeding intolerance occurred less often (P<0.0001), number of days to full feeds was lower (P<0.001), incidence of NEC was lower (P<0.011), and total hospitalization costs were lower by up to $106,968 per infant (P<0.004) in those fed an EHM diet compared with the other groups. Average weight gain per day was similar among the four groups (18.5 to 20.6 g per day). CONCLUSIONS: Implementing an EHM diet in our VLBW infants has led to a significant decrease in the incidence of NEC. Other benefits of this diet include: decreased feeding intolerance, shorter time to full feeds, shorter length of stay, and lower hospital and physician charges for extremely premature and VLBW infants.
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Enterocolitis Necrotizante/dietoterapia , Enterocolitis Necrotizante/economía , Fenómenos Fisiológicos Nutricionales del Lactante , Recien Nacido Prematuro , Recién Nacido de muy Bajo Peso , Leche Humana , Animales , Peso al Nacer , Bovinos , Enterocolitis Necrotizante/prevención & control , Femenino , Alimentos Fortificados , Edad Gestacional , Hospitalización/economía , Humanos , Lactante , Fórmulas Infantiles , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Modelos Lineales , Masculino , Leche , Bancos de Leche Humana/economía , Estudios Retrospectivos , Aumento de PesoRESUMEN
The objective of this study was to evaluate the functionality of two intervertebral fusion implants, a porous nickel-titanium and a conventional titanium cage system in a sheep model. Eighteen sheep each received the two-implant devices at L2-L3 and L4-L5 lumbar levels. The sheep were sacrificed at three different postsurgical periods: three, six and 12 months. Lumbar segments were harvested. Qualitative (macroscopic and microscopic) and quantitative (histomorphometric) histological analysis were carried out on histological slides. The results indicated that a porous nickel-titanium had obtained a better osseointegration than the titanium implant. The functionality of two implants seemed to be influenced by the implant structure and shape. However, biocompatibility of two implants seemed comparable.
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Vértebras Lumbares/cirugía , Fusión Vertebral/instrumentación , Fusión Vertebral/métodos , Animales , Materiales Biocompatibles , Modelos Animales de Enfermedad , Ensayo de Materiales , Níquel , Porosidad , Ovinos , TitanioRESUMEN
Bloodstream infection (BSI) by microorganisms can lead to sepsis. This condition has a high mortality rate, which rises significantly with delays in initiation of appropriate antimicrobial treatment. Current culture methods for diagnosing BSI have long turnaround times and poor clinical sensitivity. While clinicians wait for culture diagnosis, patients are treated empirically, which can result in inappropriate treatment, undesirable side effects and contribute to drug resistance development. Molecular diagnostics assays that target pathogen DNA can identify pathogens and resistance markers within hours. Early diagnosis improves antibiotic stewardship and is associated with favorable clinical outcomes. Nonetheless, limitations of current molecular diagnostic methods are substantial. This article reviews recent commercially available molecular methods that use pathogen DNA to diagnose BSI, either by testing positive blood cultures or directly testing patient blood. We critically assess these tests and their application in clinical microbiology. A view of future directions in BSI diagnosis is also provided.
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Técnicas de Diagnóstico Molecular , Juego de Reactivos para Diagnóstico , Sepsis/diagnóstico , Humanos , Técnicas de Diagnóstico Molecular/economía , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Juego de Reactivos para Diagnóstico/economía , Juego de Reactivos para Diagnóstico/normas , Sensibilidad y Especificidad , Sepsis/microbiología , Sepsis/virologíaRESUMEN
We have evaluated a genotoxicity assay that combines in situ end-labeling, colloidal gold tagging and electron microscopy in order to adapt it to the measurement of in vitro biomaterial-induced genotoxicity. Human lymphocytes were cultured in semi-physiological medium which had been previously exposed to biomaterial extracts of commercially pure titanium following ISO standards. In order to visualize the location of induced DNA strand breaks, cells were then exposed to exonuclease III which partially digests and amplifies lesions by releasing nucleotides at free 3' hydroxyl ends from nicked double-stranded DNA. The resulting single-stranded DNA was allowed to hybridize with short oligonucleotides of random sequences including biotinylated dUTP. After random priming using Escherichia coli DNA polymerase I, incorporation of biotin-dUTP was detected by immunogold binding to the chromatin. Cells exposed to a mutagenic concentration of methyl methanesulfonate, as a positive control, showed a significantly higher and stronger gold staining than both titanium-exposed and unexposed specimens. This assay allows a precise localization and quantification of both in vitro DNA breakage and DNA repair. It could provide a powerful tool for rapid assessment of the genotoxic potential of new biomaterials.
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Materiales Biocompatibles/efectos adversos , Daño del ADN , ADN/ultraestructura , Células Cultivadas , ADN/efectos de los fármacos , ADN Polimerasa I , Reparación del ADN , ADN de Cadena Simple/efectos de los fármacos , ADN de Cadena Simple/ultraestructura , Escherichia coli/enzimología , Exodesoxirribonucleasas/farmacología , Amplificación de Genes , Humanos , Inmunohistoquímica , Hibridación in Situ , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Metilmetanosulfonato , Microscopía Inmunoelectrónica , Mutágenos , Titanio/efectos adversos , Uridina TrifosfatoRESUMEN
The genotoxicity level of nickel-titanium (NiTi) was compared to that of its pure constituents, pure nickel (Ni) and pure titanium (Ti) powders, and also to 316L stainless steel (316L SS) as clinical reference material. In order to do so, a dynamic in vitro semiphysiological extraction was performed with all metals using agitation and ISO requirements. Peripheral blood lymphocytes were then cultured in the presence of all material extracts, and their comparative genotoxicity levels were assessed using electron microscopy-in situ end-labeling (EM-ISEL) coupled to immunogold staining. Cellular chromatin exposition to pure Ni and 316L SS demonstrated a significantly stronger gold binding than exposition to NiTi, pure Ti, or the untreated control. In parallel, graphite furnace atomic absorption spectrophotometry (AAS) was also performed on all extraction media. The release of Ni atoms took the following decreasing distribution for the different resulting semiphysiological solutions: pure Ni, 316L SS, NiTi, Ti, and controls. Ti elements were detected after elution of pure titanium only. Both pure titanium and nickel-titanium specimens obtained a relative in vitro biocompatibility. Therefore, this quantitative in vitro study provides optimistic results for the eventual use of nickel-titanium alloys as surgical implant materials.
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Aleaciones/farmacología , Materiales Biocompatibles/farmacología , Mutágenos/farmacología , Níquel/farmacología , Acero Inoxidable/farmacología , Titanio/farmacología , Aleaciones/química , Análisis de Varianza , Materiales Biocompatibles/química , Células Cultivadas , Cromatina/efectos de los fármacos , Humanos , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Linfocitos/efectos de los fármacos , Microscopía Electrónica , Mutágenos/química , Níquel/química , Prótesis e Implantes , Espectrofotometría Atómica , Acero Inoxidable/química , Titanio/químicaRESUMEN
Porous nickel-titanium (NiTi) alloys have demonstrated bone attachment as well as tissue ingrowth in the past. However, very few studies have compared porous NiTi soft and hard tissue reactions, and in vitro cell response. We therefore have evaluated the general muscle and bone reaction to porous nickel-titanium. The latter material was implanted in rabbit tibias and back muscle, and assessed after three, six and twelve weeks of implantation. Porous NiTi specimens did not cause any adverse effect regardless of both implantation site and post-surgery recovery time. Muscle tissue exhibited thin tightly adherent fibrous capsules with fibers penetrating into implant pores. We observed that attachment strength of the soft tissue to the porous implant seemed to increase with post-implantation time. Bone tissue demonstrated good healing of the osteotomy. There was bone remodeling characterized by osteoclastic and osteoblastic activity in the cortex. This general good in vivo biocompatibility with muscle and bone tissue corresponded very well with the in vitro cell culture results we obtained. Fibroblasts seeded on porous nickel-titanium sheets managed to grow into the pores and all around specimen edges showing an another interesting cytocompatibility behavior. These results indicate good biocompatibility acceptance of porous nickel-titanium and are very promising towards eventual NiTi medical device approbation.
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Materiales Biocompatibles , Ensayo de Materiales , Níquel , Prótesis e Implantes , Titanio , Tejido Adiposo/patología , Animales , División Celular , Células Cultivadas , Femenino , Fibroblastos/citología , Músculo Esquelético/patología , Músculo Esquelético/cirugía , Oseointegración , Conejos , Tibia/patología , Tibia/cirugíaRESUMEN
We report the case of a 55-year-old female patient, previously cholecystectomized, who was admitted to the Hospital because of recurrent biliary abdominal pain, cholestasis and common bile duct enlargement by ultrasonography. 48 hours after an endoscopic sphincterotomy the patient developed abdominal pain and fever. CT scan demonstrated air and an infected liquid collection in the retroperitoneum. Although a percutaneous drainage was attempted, the persistence of the symptoms and the low drainage outflow of the infected material made surgical treatment necessary. Duodenal perforation in endoscopic sphincterotomy is an unusual but severe complication that leads to a high mortality rate if surgical treatment is not applied promptly. Sometimes retropneumoperitoneum can be satisfactory solved just with a conservative medical therapy, but if there is a suspected or confirmed infected collection surgical treatment must be applied promptly.
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Absceso/etiología , Complicaciones Posoperatorias/etiología , Esfinterotomía Endoscópica , Absceso/diagnóstico , Absceso/terapia , Enfermedad Aguda , Terapia Combinada , Femenino , Humanos , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/terapia , Espacio RetroperitonealRESUMEN
The equiatomic Nickel-Titanium (NiTi) alloy has exceptional mechanical properties such as shape memory and superelasticity. It already has applications in orthodontics and is a promising orthopaedic biomaterial. Cytocompatibility studies must therefore be undertaken. The objective of this study is to determine the biological response that NiTi elicits compared to other orthopaedic metals currently used in orthopaedic surgery. Cytotoxicity tests constitute an efficient first step in a biocompatibility study and contribute to reduce animal use in laboratory. Direct contact and agar diffusion cytotoxicity assays were performed following ASTM standards #F813-83 and #F895-84 respectively. Confluent L-929 fibroblasts culture plates were incubated (directly or under an agar bed) in presence of NiTi, titanium (Ti), vitallium (Co-Cr-Mo) and 316L stainless steel discs. Following exposition to specimens, a vital dye was added to the plates. All cultures were evaluated for cytotoxic reactions, under light microscopy. Direct contact and agar diffusion assays indicated that all metals tested induced a mild biological reaction. Specimens were ranked according to an index of biological response, they are enumerated here in decreasing order of cytotoxicity: NiTi approximately Co-Cr-Mo >> pure grade 4 Ti approximately pure grade 1 Ti approximately Ti 6A1 4V approximately 316L stainless steel. Furthermore, plasma surface modification increased the cytocompatibility of NiTi.
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Fibroblastos/efectos de los fármacos , Níquel/farmacología , Titanio/farmacología , Materiales Biocompatibles , Humanos , Ensayo de Materiales , Microscopía , Níquel/efectos adversos , Ortopedia , Prótesis e Implantes , Acero Inoxidable/farmacología , Titanio/efectos adversos , Vitalio/farmacologíaRESUMEN
Using the 2006 Homescan panel, we estimate the changes in energy, fat and sodium purchases resulting from a tax that increases the price of sugar-sweetened beverages (SSBs) by 20% and the effect of such a tax on body weight. In addition to substitutions that may arise with other beverages, we account for substitutions between SSBs and 12 major food categories. Our main findings are that the tax would result in a decrease in store-bought energy of 24.3kcal per day per person, which would translate into an average weight loss of 1.6 pounds during the first year and a cumulated weight loss of 2.9 pounds in the long run. We do not find evidence of substitution to sugary foods and show that complementary foods could contribute to decreasing energy purchases. Despite their significantly lower price elasticity, the tax has a similar effect on calories for the largest purchasers of SSBs.