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OBJECTIVES: To perform a systematic review and meta-analysis to assess the clinical efficacy of collagen-based supplements on knee osteoarthritis (OA) symptoms. METHODS: Until October 2023, we conducted searches on the MEDLINE, EMBASE, Web of Science, and Scopus databases to identify randomised controlled trials (RCTs) that reported the effects of oral collagen-based supplements on knee OA. Quantitative data from outcomes were pooled using a random- or fixed-effects model (depending on inter-study variability) and the generic inverse variance method. The Cochrane Risk of Bias 2.0 tool was employed to assess the risk of bias. RESULTS: This systematic review incorporated information of 870 participants included from 11 RCTs, with 451 allocated to the collagen supplementation group and 419 to the placebo group. The meta-analysis revealed an overall significant improvement of both function [MD, -6.46 (95% CI -9.52, -3.40); I2=75%; p=0.00001] and pain scores [MD, -13.63 (95% CI -20.67, -6.58); I2=88%; p=0.00001], favouring collagen supplementation. CONCLUSIONS: The results of this meta-analysis suggest that oral collagen administration relieves OA symptoms. Our findings revealed noteworthy improvements, statistically and clinically, in both functional and pain scores.
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Background Applying topical vancomycin has shown a decrease in the likelihood of surgical site infections (SSIs) in surgeries linked to a heightened risk of severe and resistant infections. Nevertheless, the effectiveness of this prophylactic approach has not been assessed in open ankle surgeries with internal fixation. Objective This study aimed to assess whether topical vancomycin diminishes the risk of SSI in patients with ankle fractures undergoing open reduction with internal fixation. Methods A randomized, controlled, double-blind clinical trial was carried out. Patients were divided into two groups in a 1:1 ratio. The control group received the standard prophylactic treatment with IV cephalothin 1 g, while the intervention group was administered topical vancomycin (1 g) in addition to the standard prophylactic treatment. The main outcomes were the SSI rates at 14 days, 28 days, and three months post-surgery, based on relevant clinical signs and laboratory tests. Results One hundred thirty-two patients were randomized (51.2% female), with 66 subjects included in each intervention arm. A total of 97.7% of them completed the study. Both groups were homogeneous in baseline characteristics. There were two SSIs in both the vancomycin group (3.3%) and the control group (3.5%), with no statistical differences (p = 0.945). The microorganisms isolated as causal agents were Staphylococcus aureus and Acinetobacter baumannii. By the three-month follow-up, no infections were noted in both intervention groups. Conclusion These results indicate that the topical administration of vancomycin may not represent an advantage in preventing SSI in ankle fractures requiring open reduction with internal fixation at the three-month postoperative stage.
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OBJECTIVES: Genicular nerve block (GNB) has emerged as novel non-surgical therapy for symptomatic knee osteoarthritis (OA). The objective was to evaluate GNB versus placebo and other intraarticular (IA) therapies. METHODS: The Medline, Embase, and Scopus databases were searched from their inception to January 2021. Only randomized controlled trials (RCTs) were included. A random-effects model and the generic inverse variance method were used for quantitative data synthesis. Heterogeneity was tested with the I2 index. RESULTS: Regarding pain a statistically significant scores were demonstrated at 1 and 3 months overall total effect of 1.43 [95% CI, 0.86, 1.99]; P=0.00001; I2=85%). Similarly, for knee function a total effect of 0.71 [95% CI, 0.35, 1.06]; P=0.00001; I2=69%) at 1 and 3 months, statistically significant. The minimal clinical important difference regarding pain was achieved at 1 and 3 months. DISCUSSION: Nevertheless, GNB achieved the MCID for knee OA pain and statistically significant results for knee functions. We cannot recommend its routine use besides being a safe procedure so far, evidence is fair on GNB for primary knee OA due to study heterogeneity and limited follow-up.
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In response to the environmental impacts of conventional polyurethane adhesives derived from fossil fuels, this study introduces a sustainable alternative utilizing lignin-based polyols extracted from rice straw through a process developed at INESCOP. This research explores the partial substitution of traditional polyols with lignin-based equivalents in the synthesis of reactive hot melt polyurethane adhesives (HMPUR) for the footwear industry. The performance of these eco-friendly adhesives was rigorously assessed through Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), rheological analysis, and T-peel tests to ensure their compliance with relevant industry standards. Preliminary results demonstrate that lignin-based polyols can effectively replace a significant portion of fossil-derived polyols, maintaining essential adhesive properties and marking a significant step towards more sustainable adhesive solutions. This study not only highlights the potential of lignin in the realm of sustainable adhesive production but also emphasises the valorisation of agricultural by-products, thus aligning with the principles of green chemistry and sustainability objectives in the polymer industry.
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OBJECTIVE: Tibial tubercle fractures are a unique class of pediatric orthopaedic injuries that frequently necessitate surgical treatment and strict monitoring due to the associated risk of acute compartment syndrome (ACS). However, current literature is conspicuously limited in its ability to estimate the risk of ACS after these fractures. Therefore, the purpose of this study is to utilize a nationwide database to estimate the prevalence of ACS after pediatric tibial tubercle fractures. METHODS: We utilized the Healthcare Cost and Utilization Project's Kids' Inpatient Database (2019) to identify all pediatric patients, 18 years of age and under, with isolated tibial tubercle fractures (International Classification of Diseases, 10th revision Clinical Modification S82.151-S82.156) and ACS (T79.A0, T79.A2, T79.A29). Patients were excluded if they had additional lower extremity injuries (ie, tibial shaft, plateau, etc). A subanalysis was conducted for those undergoing fasciotomy, with and without an ACS diagnosis. RESULTS: Among the 591 isolated tibial tubercle fractures, there were 8 ACS cases for a prevalence of 1.35%. There were 22 (3.72%) additional cases of fasciotomy without an ACS diagnosis. All ACS cases were diagnosed during the original hospitalization; all were male and had closed fractures. The cohort included 469 teenagers (13+ years) and 77 pre-teens, with 40 females and 506 males. Racial demographics: 132 white, 232 black, 112 Hispanic, 15 Asian, 4 Native American, 23 unknown, and 28 others. No significant associations were found between ACS and age, race, insurance status, mechanism of injury, or hospital region. CONCLUSION: The rate of ACS in pediatric tibial tubercle fractures appears to be much lower than previously reported, at 1.35%. However, the nearly three-fold higher prevalence of fasciotomy without an ACS diagnosis, suggests a generous use of prophylactic fasciotomies and/or an undercharacterization of actual ACS cases from miscoding. This is the first and largest study to employ a nationally representative database to investigate the prevalence of ACS after tibial tubercle fractures. LEVEL OF EVIDENCE: Level III.
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INTRODUCTION: To evaluate the relationship between initial displacement in proximal humeral fractures and fatty degeneration of the rotator cuff measured by CT according to the Goutallier classification. MATERIAL AND METHODS: This cross-sectional observational study evaluated patients with proximal humeral fractures over a six-month period. The study included patients ≥ 18 years old with complete radiological views (anteroposterior, lateral, and Grashey) and a CT scan of the affected shoulder; previous fracture or ipsilateral shoulder surgery were excluded. Neer's classification system and Goutallier stages were used to evaluate the patients. Demographic data were collected and, two groups were analysed according to age (≤ 50 years and > 50 years). RESULTS: Sixty-two patients were included (m = 36, f = 26, ratio 1.3:1); seven patients were excluded. Male patients (36, 58.1%), patients older than 50 years (33, 53.2%) and a low-energy injury mechanism (36, 58.1%) were the most frequent cases. According to the Neer system, the most common proximal humerus fracture was fracture-dislocation in 17 (27.4%) cases. The most common stage in Goutallier's classification was I (some fatty streaks) in 22 (35.4%) cases. Younger patients (≤ 50 years) had more displaced fractures with low fatty degeneration (p = < 0.001) than older patients (> 50 years), who had minimally displaced fractures with greater fatty degeneration (p = 0.567). CONCLUSIONS: High-energy mechanisms are associated with younger patients and a more displaced fracture according to the Neer classification. Older patients had a more advanced Goutallier stage and lesser displaced fracture. We should consider a more aggressive approach in the treatment of non-displaced fractures in elderly patients, less conservative and more surgical management, to obtain a better clinical evolution after the treatment of these kinds of fractures. LEVEL OF EVIDENCE: IV.
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CONTEXT: Orthopaedic surgery has become increasingly competitive over the years, with the COVID-19 pandemic creating additional challenges for applicants and programs. To promote an equitable match experience, the American Orthopaedic Association (AOA) introduced a formal preference signaling (PS) system into the 2022-2023 application cycle. PS allows applicants to indicate their heightened interest in specific programs, which improves the likelihood of receiving an interview and ultimately matching at their desired residency program. OBJECTIVES: The objective of this anonymous survey is to assess applicants' opinions and perspectives toward PS in orthopaedic surgery prior to the 2022-2023 match results. Additionally, we sought to evaluate the signaling strategies being utilized by applicants. METHODS: An anonymous 22-question survey was distributed to applicants of an orthopaedic surgery residency program (34.2â¯% response rate). Responses were collected after the application submission deadline but before the match lists and results were available. This survey included questions germane to demographics, signal utilization, signaling reasons and strategies, and opinions toward PS. Descriptive statistics were calculated utilizing R (version 4.2.1) and RStudio. RESULTS: Most respondents (96.1â¯%) participated in PS, and 96.7â¯% utilized all 30 signals. Signaling encouraged 24.2â¯% of applicants to apply to fewer programs. In accordance with guidelines, 83.2â¯% of respondents signaled each away rotation program; however, only 53â¯% signaled their home program. Applicants commonly signaled 1-10 "reach" and "safety" programs each. Proximity to Family and Perceived Operative Experience were the most important reasons for signaling, whereas Program Prestige was the least. A program's social presence and virtual interview option did not influence many applicants' decisions for signaling. Most applicants believe that the COVID-19 pandemic and pass/fail licensure examinations influenced PS adoption. Sixty-seven of 149 respondents (45â¯%) claimed that applicants and programs benefit equally from PS, while 41â¯% believe programs benefit more. Nearly half (40.94â¯%) knew very little or nothing about PS. CONCLUSIONS: During the inaugural introduction of PS in orthopaedic surgery, nearly every applicant utilized all 30 signals, prioritizing factors like family proximity and perceived operative experience over program prestige. This shift reflects the importance of geographic location and presumed training quality. Despite unfamiliarity toward PS, personalized signaling strategies were implemented, accompanied by a slight decrease in application volumes. The 30 allotted signals in orthopaedic surgery may serve as an informal application cap due to the necessity of signaling a program for an interview invite. However, improved educational efforts are needed to enhance the understanding and maximize the benefits of PS for both applicants and programs.
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Background: Many orthopaedic surgeons routinely prescribe aspirin (ASA) as prophylaxis for venous thromboembolism (VTE) following hip fracture surgery (HFS). The purpose of this study is to assess the effectiveness of aspirin to other agents in preventing VTE and mortality following hip fracture surgery. Methods: Following PRISMA guidelines, we performed a search for HFS studies from 1998 to 2023 reporting comparisons between aspirin and other chemoprophylaxis methods for VTE (DVT - deep vein thrombosis; PE - pulmonary embolism). SPSS Meta-analysis function was used to calculate Mean Effect Size Estimate (MESE) and 95 % Confidence Intervals for each outcome. Reverse Fragility Index (RFI) and Fragility Quotient (FQ) were calculated for each study. Results: Of the 847 articles screened, 4 studies with 5 comparisons met the search criteria to be included for analysis. A total of 1194 participants were included in these studies. There was a decreased risk of mortality seen with use of aspirin compared to other agents (MESE = 0.86, 95 % CI: [0.07-1.66]; p=.03). There was no increased risk of DVT or PE with use of aspirin (both p>.4). The overall RFI and FQ for all 19 outcomes were 12 (IQR: 6.5-15) and 0.080 (IQR: 0.027-0.110), respectively. Ten studies (52.6 %) reported a loss-to-follow-up (LTF) greater than the overall RFI. Conclusions: Aspirin demonstrates similar protective effects on prevention of VTE compared to other agents and may have significant protective effects on overall mortality following surgical intervention for hip fractures. However, the current evidence concerning its use in this arena is less than robust, with more than half of the studied outcomes considered statistically fragile.
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PURPOSE: To perform a quantitative analysis of the amount of cancellous bone in the distal radius and olecranon process by segmentation of computed tomographic scans. As a secondary analysis, the bone density by Hounsfield units was evaluated at the same sites. METHODS: Computed tomography angiography images of the upper extremity were analyzed using 3-D Slicer™ medical imaging software. Bone volume (cm3) and density (Hounsfield units) from the cancellous bone between the distal radius and the olecranon process were compared by creating an advanced three-dimensional model. The images were analyzed in duplicate, and an intraclass correlation was performed to assess measurement consistency. RESULTS: Twenty subjects were included. A total volume of 5.01 ± 1.21 cm3 and 5.81 ± 1.61 cm3 for the distal radius and the olecranon process (p < .0001), respectively, was found. Regarding Hounsfield units, the density of the olecranon process was 303.1 ± 73.26, and the distal radius was 206.5 ± 63.73 (p < .0001). All intraclass correlation coefficients were >0.992. CONCLUSION: These results suggest that the olecranon process has a greater volume and a higher bone mineral density than the distal radius. With these results, the surgeon will have the ability to decide the quantity and quality of bone grafts according to the surgical procedure.
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Densidad Ósea , Imagenología Tridimensional , Radio (Anatomía) , Tomografía Computarizada por Rayos X , Humanos , Radio (Anatomía)/diagnóstico por imagen , Radio (Anatomía)/cirugía , Masculino , Femenino , Persona de Mediana Edad , Adulto , Tomografía Computarizada por Rayos X/métodos , Olécranon/diagnóstico por imagen , Olécranon/cirugía , Trasplante Óseo/métodos , Anciano , Extremidad Superior/cirugía , Extremidad Superior/diagnóstico por imagen , Hueso Esponjoso/diagnóstico por imagen , Hueso Esponjoso/trasplanteRESUMEN
Objective: SARS-CoV-2 infection induces an immune response that causes excessive inflammation damaging cardiac tissue and vascular endothelium. The objective of this study is to review a series of cases of hospitalized patients with pre-existing cardiac disease to describe the clinical behavior and highlight the low frequency of morbidity and mortality. Method: Retrospective study of 17 patients with a confirmed diagnosis of COVID-19 by polymerase chain reaction test or antigen test, a history of cardiovascular disease with or without comorbidities, and a history of at least one dose of the vaccine for COVID-19, during the period between December 30, 2021 and March 17, 2022 at the Ignacio Chávez National Institute of Cardiology in Mexico City. Results: The most frequent cardiac pathology was acute myocardial infarction (31.25%) and the most common arrhythmia was atrial fibrillation (25%). The median number of days of hospital stay was 10 days (interquartile range: 4-14). Regarding the outcomes, 94% of the patients were discharged due to clinical improvement, and only one patient died during his hospitalization. Conclusions: It is crucial to continue investigating SARS-CoV-2 effects in patients pre-existing heart disease and in those with persistent symptoms after infection. This will allow the development of more effective strategies for the treatment and prevention of cardiovascular complications associated with COVID-19.
Objetivo: La infección por SARS-CoV-2 induce una respuesta inmunitaria que causa una inflamación excesiva dañando al tejido cardiaco y al endotelio vascular. El objetivo de este estudio es revisar una serie de casos de pacientes hospitalizados con patología cardiaca preexistente para describir el comportamiento clínico y resaltar la baja frecuencia de morbimortalidad. Método: Estudio retrospectivo de 17 pacientes con diagnóstico confirmado de COVID-19 mediante prueba de reacción en cadena de la polimerasa o prueba de antígenos, antecedente de enfermedad cardiovascular en presencia o no de comorbilidad, y antecedente de al menos una dosis de la vacuna para la COVID-19, durante el periodo entre el 30 de diciembre de 2021 y el 17 de marzo de 2022, en el Instituto Nacional de Cardiología Ignacio Chávez de la Ciudad de México. Resultados: La patología cardiaca previa más frecuente fue el infarto agudo de miocardio (31.25%), y la arritmia más común fue la fibrilación auricular (25%). La mediana de días de estancia hospitalaria fue de 10 (rango intercuartílico: 4-14). En cuanto a los desenlaces, el 94% de los pacientes fueron dados de alta por mejoría clínica y solo un paciente falleció durante su internamiento. Conclusiones: Es crucial continuar investigando y monitoreando los efectos del SARS-CoV-2 en los pacientes con enfermedades cardiacas preexistentes y en aquellos con síntomas persistentes después de la infección. Esto permitirá desarrollar estrategias más efectivas para el tratamiento y la prevención de las complicaciones cardiovasculares asociadas a la COVID-19.
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Hyaline cartilage is a highly specialized tissue. When injured, its repair capacity is low, which results in the massive destruction of the articular surface. Using tissue engineering and genetic engineering techniques, it is possible to provide a suitable microenvironment providing chondrocyte growth factors involved in the development of hyaline cartilage proteins, as well as cell proliferation and differentiation. Our aim was to stimulate the synthesis of an extracellular matrix via the chondrocytes included in a fibrin matrix through the addition or overexpression of IGF1 and/or FGF2, while maintaining a constant agitation of the culture medium. Collagen type II and glycosaminoglycans increased during the entire incubation time. In contrast, collagen type I decreased its expression under the same culture conditions, transfecting or supplementing growth factors to chondrocytes. However, chondrocytes that were not transfected or supplemented showed a general increase in the proteins analyzed in this study. The presence of IGF1 and FGF2 increased the protein synthesis of the hyaline cartilage, regardless of which one was the source of growth factors. Continuous agitation using the spinner flask allows for the adequate nutrition of chondrocytes included in the fibrin matrix. However, they require growth factors to up-regulate or down-regulate collagenous proteins.
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Gelatinous zooplankton constitutes a polyphyletic group with a convergent evolutionary history and poorly known biogeographical patterns. In the Gulf of Mexico, a region with complex geological, hydrological, and biotic histories, the study of this group has been limited to taxonomical and ecological aspects. In this study, we implemented a track analysis to identify distributional patterns of gelatinous zooplankton in the Gulf of Mexico and adjacent waters based on a dataset of 6067 occurrence records corresponding to Hydrozoa, Scyphozoa, Cubozoa, Ctenophora, Chaetognatha, Thaliacea, and Appendicularia. Information was compiled from the Global Biodiversity Facility Information (GBIF) and Ocean Biodiversity Information System (OBIS) databases and peer-reviewed literature. Individual tracks were constructed by joining the minimum distance between the occurrence localities of each taxon using a minimum spanning tree algorithm. We identified generalized tracks using parsimony analysis of endemicity with progressive character elimination (PAE-PCE). The areas where different generalized tracks overlapped were considered to represent panbiogeographical nodes. Seven generalized tracks (two with nested patterns) and six panbiogeographical nodes were recognized, mainly in neritic zones. The distributional patterns of gelatinous zooplankton allowed us to identify four biogeographic areas, supporting previously proposed biogeographic schemes. Gelatinous zooplankton in the Gulf of Mexico showed a convergent spatial distribution that can be explained by vicariant and dispersal events. The historical biogeography of the gelatinous biotas of the Gulf of Mexico has been little studied compared to ecological approaches, and the lack of integrative studies considering historical patterns is evident. This type of research is fundamental to understanding the evolutionary history of natural resources from a spatial perspective, identifying sites of biodiversity and endemism, and establishing a biogeographic baseline of the region for further studies.
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Biodiversidad , Zooplancton , Zooplancton/clasificación , Zooplancton/fisiología , Animales , Golfo de México , Evolución Biológica , FilogeografíaRESUMEN
OBJECTIVE: Extracorporeal shockwave therapy (ESWT) has been used as a therapeutic option for plantar fasciitis. The objective was to investigate the effect of ESWT over the plantar fascia thickness. METHODS: MEDLINE, Embase, Web of Science, and SCOPUS databases were searched for randomized controlled trials evaluating the effect of ESWT in patients with plantar fasciitis, comparing ESWT with another treatment. Meta-analysis was conducted using a random-effects model and the generic inverse variance method. Meta-regression and subgroup analyses were also carried out. RESULTS: A total of 14 studies (867 participants) were included. ESWT significantly decreased plantar fascia thickness (weighted mean difference [WMD], -0.21 mm [95% CI -0.39, -0.02]; p = 0.03). No significant improvement in pain was observed (WMD, -0.51 cm [95% CI -1.04, 0.01]; p = 0.06) compared with non-surgical interventions. CONCLUSIONS: Our results suggest that plantar fascia thickness is significantly decreased after ESWT intervention in patients with plantar fasciitis. However, pain relief was not significantly improved compared to other non-surgical interventions.
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Loeys-Dietz syndrome (LDS) is an autosomal-dominant connective tissue disorder associated with mutations in the transforming growth factor ß receptor. It is characterized by distinctive craniofacial changes, skeletal features, and cardiovascular complications. We present a case of a 24-year-old male with development delay and a one-year history of progressively worsening dyspnea on moderate exertion and orthopnea. Echocardiography revealed right atrial and right ventricle dilation, right ventricle hypertrophy, atrial septal defect, and aneurysmal dilation of the pulmonary artery trunk. This case underscores the importance of early detection and comprehensive imaging in patients suspected of having LDS, particularly considering the potential for atypical vascular manifestations.
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Diagnóstico Tardío , Ecocardiografía , Defectos del Tabique Interatrial , Síndrome de Loeys-Dietz , Arteria Pulmonar , Humanos , Masculino , Síndrome de Loeys-Dietz/complicaciones , Síndrome de Loeys-Dietz/diagnóstico , Defectos del Tabique Interatrial/complicaciones , Defectos del Tabique Interatrial/diagnóstico , Arteria Pulmonar/diagnóstico por imagen , Arteria Pulmonar/anomalías , Adulto Joven , Ecocardiografía/métodos , Dilatación Patológica , Diagnóstico DiferencialRESUMEN
The growing trend in fruit wine production reflects consumers' interest in novel, diverse drinking experiences and the increasing demand for healthier beverage options. Fruit wines made from kiwi, pomegranates, and persimmons fermented using S. bayanus Lalvin strain EC1118 demonstrate the versatility of winemaking techniques. Kiwifruit, persimmon, and pomegranate wines were analyzed using HPLC and GC-TOFMS analyses to determine their concentrations of phenolic acids and volatile compounds. These results were supported by Fourier transform infrared (FTIR) spectroscopy to characterize and compare chemical shifts in the polyphenol regions of these wines. The wines' characterization included an anti-inflammatory assay based on NO, TNF-alpha, and IL-6 production in the RAW 264.7 macrophage model. FTIR spectroscopy predicted the antioxidant and phenolic contents in the wines. In terms of polyphenols, predominantly represented by chlorogenic, caffeic, and gallic acids, pomegranate and kiwifruit wines showed greater benefits. However, kiwifruit wines exhibited a highly diverse profile of volatile compounds. Further analysis is necessary, particularly regarding the use of other microorganisms in the fermentation process and non-Saccharomyces strains methods. These wines exhibit high biological antioxidant potential and health properties, providing valuable insights for future endeavors focused on designing healthy functional food products.
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Antiinflamatorios , Fermentación , Frutas , Saccharomyces cerevisiae , Compuestos Orgánicos Volátiles , Vino , Vino/análisis , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/metabolismo , Ratones , Saccharomyces cerevisiae/metabolismo , Antiinflamatorios/farmacología , Antiinflamatorios/análisis , Antiinflamatorios/química , Frutas/química , Frutas/metabolismo , Animales , Células RAW 264.7 , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Polifenoles/análisis , Antioxidantes/análisis , Actinidia/química , Granada (Fruta)/químicaRESUMEN
Chagas disease is a zoonosis caused by the protozoan Trypanosoma cruzi and transmitted through the feces of triatomines, mainly in Latin America. Since the 1950s, chemical insecticides have been the primary method for controlling these triatomines, yet resistance has emerged, prompting the exploration of alternative approaches. The objective of this research was to test the capacity of the entomopathogenic nematodes Heterorhabditis indica and its symbiotic bacteria Photorhabdus luminescens, to produce mortality of Triatoma dimidiata a key vector of T. cruzi in Mexico under laboratory conditions. Two bioassays were conducted. In the first bioassay, the experimental unit was a 250 ml plastic jar with 100 g of sterile soil and three adult T. dimidiata. Three nematode quantities were tested: 2250, 4500, and 9000 nematodes per 100 g of sterile soil (n/100 g) per jar, with 3 replicates for each concentration and 1 control per concentration (1 jar with 100 g of sterile soil and 3 T. dimidiata without nematodes). The experimental unit of the second bioassay was a 500 ml plastic jar with 100 g of sterile soil and 4 adult T. dimidiata. This bioassay included 5, 50, 500, and 5000 n/100 g of sterile soil per jar, with 3 replicates of each quantity and 1 control per quantity. Data were analyzed using Kaplan-Meyer survival analysis. Electron microscopy was used to assess the presence of nematodes and tissue damage in T. dimidiata. The results of the first bioassay demonstrated that the nematode induced an accumulated average mortality ranging from 55.5 % (2250 n/100 g) to 100 % (4500 and 9000 n/100 g) within 144 h. In the second bioassay, the 5000 n/100 g concentration yielded 87.5 % mortality at 86 h, but a concentration as small as 500 n/100 g caused 75 % mortality from 84 h onwards. Survival analysis indicated higher T. dimidiata mortality with increased nematode quantities, with significant differences between the 4500, 5000, and 9000 n/100 g and controls. Electron microscopy revealed the presence of nematodes and its presumably symbiotic bacteria in the digestive system of T. dimidiata. Based on these analyses, we assert that the H. indica and P. luminescens complex causes mortality in adult T. dimidiata under laboratory conditions.
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Enfermedad de Chagas , Photorhabdus , Triatoma , Animales , Enfermedad de Chagas/parasitología , Enfermedad de Chagas/prevención & control , Triatoma/parasitología , México , Análisis de Supervivencia , Rabdítidos/fisiología , Agentes de Control Biológico , Control Biológico de Vectores/métodos , Rhabditoidea/fisiología , Vectores de Enfermedades , Trypanosoma cruzi/fisiologíaRESUMEN
Two-dimensional (2D) agarose gel electrophoresis is the method of choice to analyze DNA topology. The possibility to use E. coli strains with different genetic backgrounds in combination with nicking enzymes and different concentrations of norfloxacin improves the resolution of 2D gels to study the electrophoretic behavior of three different families of DNA topoisomers: supercoiled DNA molecules, post-replicative catenanes, and knotted DNA molecules. Here, we describe the materials and procedures required to optimize their separation by 2D gels. Understanding the differences in their electrophoretic behavior can help explain some important physical characteristics of these different types of DNA topoisomers. Key features ⢠Preparative method to enrich DNA samples of supercoiled, catenated, and knotted families of topoisomers, later analyzed by 2D gels (or other techniques, e.g., microscopy). ⢠2D gels facilitate the separation of the topoisomers of any given circular DNA molecule. ⢠Separation of DNA molecules with the same molecular masses but different shapes can be optimized by modifying the conditions of 2D gels. ⢠Evaluating the roles of electric field and agarose concentration on the electrophoretic mobility of DNA topoisomers sheds light on their physical characteristics.
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BACKGROUND: In radiotherapy, it is essential to deliver prescribed doses to tumors while minimizing damage to surrounding healthy tissue. Accurate measurements of absorbed dose are required for this purpose. Gafchromic® external beam therapy (EBT) radiochromic films have been widely used in radiotherapy. While the dosimetric characteristics of the EBT3 model film have been extensively studied for photon and charged particle beams (protons, electrons, and carbon ions), little research has been done on α $\alpha$ -particle dosimetry. α $\alpha$ -emitting radionuclides have gained popularity in cancer treatment due to their high linear energy transfer, short range in tissue, and ability to spare surrounding organs at risk, thereby delivering a more localized dose distribution to the tumor. Therefore, a dose-calibration film protocol for α $\alpha$ -particles is required. PURPOSE: This study aimed to develop a dose-calibration protocol for the α $\alpha$ -particle emitting radionuclide 241Am, using Monte Carlo (MC) simulations and measurements with unlaminated EBT3 films. METHODS: In this study, a MC-based user code was developed using the Geant4 simulation toolkit to model and simulate an 241Am source and an unlaminated EBT3 film. Two simulations were performed: one with voxelized geometries of the EBT3 active volume composition and the other using water. The dose rate was calculated within a region of interest in the voxelized geometries. Unlaminated EBT3 film pieces were irradiated with the 241Am source at various exposure times inside a black box. Film irradiations were compared to a 6-MV photon beam from a Varian TrueBeam machine. The simulated dose rate was used to convert the exposure times into absorbed doses to water, describing a radiochromic-film-based reference dosimetry protocol for α $\alpha$ -particles. The irradiated films were scanned and through an in-house Python script, the normalized pixel values from the green-color channel of scanned film images were analyzed. RESULTS: The 241Am energy spectra obtained from the simulations were in good agreement with IAEA and NIST databases, having differences < $<$ 0.516% for the emitted γ $\gamma$ -rays and produced characteristic x-rays and < $<$ 0.006% for the α $\alpha$ -particles. Due to the short range of α $\alpha$ -particles, there was no energy deposition in the voxels outside the active 241Am source region projected onto the film surface. Thus, the total dose rate within the voxels covering the source was 0.847 ± $\pm$ 0.003 Gy/min within the sensitive layer of the film (LiPCDA) and 0.847 ± $\pm$ 0.004 Gy/min in water, indicating that the active volume can be considered water equivalent for the 241Am beam quality. A novel approach was employed in α $\alpha$ -film dosimetry using an exponential fit for the green channel, which showed promising results by reducing the uncertainty in dose estimation within 5%. Although the statistical analysis did not reveal significant differences between the 6-MV photon beam and the α $\alpha$ calibration curves, the dose-response curves exhibited the expected behavior. CONCLUSIONS: The developed MC user code simulated the experimental setup for α $\alpha$ -dosimetry using radiochromic film with acceptable uncertainty. Unlaminated EBT3 film is suitable for the dosimetry of α $\alpha$ -radiation at low doses and can be used in conjunction with other unlaminated GafChromic® films for quality assurance and research purposes.
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Due to the dramatic reduction of sea cucumber Isostichopus badionotus populations in the Yucatan Peninsula by overfishing and poaching, aquaculture has been encouraged as an alternative to commercial catching and restoring wild populations. However, the scarcity of broodstock, the emergence of a new disease in the auricularia larvae stage, and the development of skin ulceration syndrome (SUS) in the culture have limited aquaculture development. This study presents the changes in the intestine and skin microbiota observed in early and advanced stages of SUS disease in cultured juvenile I. badionotus obtained during an outbreak in experimental culture through 16S rRNA gene sequencing and histological evidence. Our results showed inflammation in the intestines of juveniles at both stages of SUS. However, more severe tissue damage and the presence of bacterial clusters were detected only in the advanced stages of SUS. Differences in the composition and structure of the intestinal and skin bacterial community from early and advanced stages of SUS were detected, with more evident changes in the intestinal microbial communities. These findings suggest that SUS was not induced by a single pathogenic bacterium. Nevertheless, a decrease in the abundance of Vibrio and an increase in Halarcobacter (syn. Arcobacter) was observed, suggesting that these two bacterial groups could be keystone genera involved in SUS disease.