Dynamic Workflow Proposal for Continuous Frameless Electromagnetic Neuronavigation in Rigid Neuroendoscopy.

BACKGROUND: Ventriculoscopic neuronavigation has been described in several articles. However, there are different ventriculoscopes and navigation systems. Due to these different combinations, it is difficult to find detailed neuronavigation protocols. We describe, step-by-step, a simple method to navigate both the trajectory until reaching the ventricular system, as well as the intraventricular work. METHODS: We use a rigid ventriculoscope (LOTTA, KarlStorz) with an electromagnetic stylet (S8-StealthSystem, Medtronic). The protocol is based on a modified or 3-dimensionally printed trocar for navigating the extraventricular step and on a modified pediatric nasogastric tube for the intraventricular navigation. RESULTS: This protocol can be set up in less than 10 minutes. The extraventricular part is navigated by introducing the electromagnetic stylet inside the modified or 3-dimensionally printed trocar. Intraventricular navigation is done by combining a modified pediatric nasogastric tube with the electromagnetic stylet inside the endoscope's working channel. The most critical point is to obtain a blunt-bloodless ventriculostomy while achieving perfect alignment of all targeted structures via pure straight trajectories. CONCLUSIONS: This protocol is easy-to-set-up, avoids head rigid-fixation and bulky optical-based attachments to the ventriculoscope, and allows continuous navigation of both parts of the surgery. Since we have implemented this protocol, we have noticed a significant enhancement in both simple and complex ventriculoscopic procedures because the surgery is dramatically simplified.

Prevalence of Anal High-Risk Human Papilloma Virus Infection and Abnormal Anal Cytology among Women Living with HIV.

Background: Women living with human immunodeficiency virus (HIV), WLWHs, are at high risk of developing anal cancer associated with high-risk human papilloma virus infection (HR-HPV). We analyzed the prevalence of anal HR-HPV infection and abnormal anal cytology in a cohort of WLWHs and assessed the risk factors for anal HR-HPV infection. Methods: We present a single-center, observational cross-sectional study. WLWHs who underwent anal cytology and anal human papilloma virus (HPV) testing were selected. High-resolution anoscopy was performed in cases of abnormal anal cytology. All suspicious lesions were biopsied. A univariate and multivariate logistic regression model was used to analyze risk factors for abnormal anal screening. The results are presented as odds ratios (ORs) and 95% confidence intervals (CIs). Results: In total, 400 WLWHs were studied. Of them, 334 met the eligibility criteria and were enrolled in the study. Abnormal anal cytology was detected in 39.5% of patients, and anal HR-HPV in 40.1%, with HPV 16 in 33 (26.6%) of them. Concomitant HR-HPV cervical infection was the only independent risk factor for HR-HPV anal infection (OR 1.67 95% CI, p < 0.001). Conclusions: WLWHs have a high prevalence of HR-HPV anal infection and anal cytologic abnormalities. HR-HPV cervical infection is the main predictor of HR-HPV anal infection.

Predictors of response to rituximab in patients with active rheumatoid arthritis and inadequate response to anti-TNF agents or traditional DMARDs.

OBJECTIVES: Identifying early predictors of response to biological agents is important for both the individual patient and health economics. The aim here was to identify clinical variables that are easily assessed in clinical practice which are associated with a major response to rituximab (moderate to good EULAR response, according to DAS28 values) in patients with active rheumatoid arthritis and inadequate response to anti-TNF agents or traditional DMARDs. METHODS: Rituximab (2x1g, two weeks apart) was administered to 108 patients in four different Spanish hospitals. The primary efficacy endpoint was the percentage of patients who achieved a major response at six months. Potential predictors of a major response were identified using multivariate binary logistic regression models. RESULTS: At six months of treatment 75.9% of patients achieved a major response (24% good and 52% moderate). Comparing the clinical features at baseline between patients who did or did not achieve a major response, significant differences were found in rheumatoid factor (RF) and anti-CCP positivity, as well as in the number of failed anti-TNF agents prior to rituximab. While rituximab delivers clinical benefit in seronegative patients, the presence of RF and/or anti-CCP consistently enriches clinical responses. The multivariate analysis showed that the best model for predicting a major EULAR response to rituximab was comprised of the following two variables: the anti-CCP antibody positivity (p=0.045) and the number of previous anti-TNF agents used (p=0.028). Using a cut-off level for CCP of 300 U/ml we found that patients with an anti-CCP titre >300 U/ml were 3-4 times more likely to achieve a major EULAR response [odds ratio (OR): 3.38; 95% CI: 1.025-11.17]. By contrast, those patients who had failed to respond to 2 or more anti-TNF agents had a 72.5% lower probability of achieving a moderate to good EULAR response (OR: 0.275; 95% CI: 0.087-0.871) than did patients who had only failed to respond to one such agent. CONCLUSIONS: A lower number of previously-failed TNF blockers and high anti-CCP titre can help select the best candidates for RTX therapy in patients with RA.

Beneficios de los obturadores quirúrgicos en la rehabilitación bucomaxilofacial. Revisión de la literatura / Benefits of surgical obturators in oral maxillofacial rehabilitation. Review of literature

RESUMEN Introducción: Las fracturas por lesión traumática, la resección quirúrgica de tumores y los defectos congénitos exponen al maxilar a agresiones, y para la rehabilitación están las prótesis obturatrices que recuperan algunas funciones como la deglución y la fonación, así como la estética. Objetivo: Resumir los beneficios del uso de prótesis obturatriz como forma de rehabilitación en los servicios de Prótesis Bucomaxilofacial. Métodos: Estudio de revisión bibliográfica en 25 publicaciones entre 2015-2020 sobre el uso de prótesis obturatriz. Se consultaron y tamizaron 153 documentos de las bases de datos de los sistemas referativos MEDLINE, PubMed y SciELO e indexadas en la Web of Sciences, Scopus, Redalyc y Latindex, con el uso de los descriptores: obturador bucal, prótesis obturatriz, cáncer bucal. Desarrollo: Los obturadores protésicos o palatinos, se indican para sellar los tejidos de la cavidad bucal expuestos de forma quirúrgica o congénita, y constituyen un sustituto fundamental del paladar duro, del hueso alveolar y de los tejidos blandos circundantes. Durante la rehabilitación, el profesional en prótesis bucomaxilofacial realizará nuevas modificaciones, a medida que el lecho quirúrgico madura. La prótesis final contará con dientes similares a una prótesis dental; el paciente la puede extraer y limpiar, además de ocuparse de la higiene del defecto. Conclusiones: Los obturadores protésicos corrigen defectos palatinos o maxilares, con varios diseños y aditamentos a aplicar, lo cual logra recuperar un alto nivel de calidad de vida de los pacientes, pues se separa la cavidad bucal de la nasal o sinusal, con una consecuente rehabilitación dental y oclusal satisfactoria. Palabras clave: obturadores palatinos; prótesis maxilofacial; rehabilitación bucal.

ABSTRACT Introduction: Fractures due to traumatic injury, surgical resection of tumors and congenital defects expose the maxilla to aggressions, and for rehabilitation there are obturator prostheses that recover some functions such as swallowing and phonation, as well as aesthetics. Objective: To summarize the benefits of the use of an obturator prosthesis as a rehabilitation form in Oral Maxillofacial Prosthesis services. Methods: Study of bibliographic review in 64 publications between 1978-2019 on the use of obturator prosthesis. 153 documents from the MEDLINE, PubMed and SciELO reference systems databases were consulted, screened and indexed on the Web of Sciences, Scopus, Redalyc and Latindex, with the use of the following descriptors: oral obturator, obturator prosthesis, oral cancer. Development: Prosthetic or palatal obturators are indicated to seal the surgically or congenitally exposed tissues of the oral cavity, and are a fundamental substitute for the hard palate, alveolar bone and surrounding soft tissues. During rehabilitation, the buccomaxillofacial prosthesis professional will make new modifications as the surgical site matures. The final prosthesis will have teeth similar to a dental prosthesis; the patient can remove and clean it, in addition to taking care of the hygiene of the defect. Conclusions: Prosthetic obturators correct palatal or maxillary defects, with various designs and attachments to be applied, which manages to recover a high level of quality of life for patients, since the oral cavity is separated from the nasal or sinus cavity, with a satisfactory dental and occlusal rehabilitation.

VARIAR Study: Assessment of short-term efficacy and safety of rituximab compared to an tumor necrosis factor alpha antagonists as second-line drug therapy in patients with rheumatoid arthritis refractory to a first tumor necrosis factor alpha antagonist. / Estudio VARIAR: VAloración de la eficacia y seguridad a corto plazo en artritis reumatoide del uso de RItuximab comparado con Antagonistas del factor de necrosis tumoral alfa en segunda línea terapéutica en pacientes con artritis reumatoide Refractarios a un primer antagonista del factor de necrosis tumoral alfa.

OBJECTIVE: to compare the short-term efficacy and safety of rituximab (RTX) therapy versus anti-TNF in rheumatoid arthritis (RA) patients after discontinuation of a first anti-TNF agent. METHODS: prospective observational multicenter study in the clinical practice setting, involving patients with severe RA refractory to a first anti-TNF agent, who received either RTX or a second anti-TNF (2TNF), comparing the efficacy endpoints, EULAR response (Good/Moderate) and safety at 6 months. RESULTS: 103 patients enrolled, 82 completed 6-month follow-up, 73.7% women. Baseline data for RTX and 2TNF groups, respectively: TJC, 8.6 and 6.6; SJC, 8.8 and 7.5; DAS28 score, 5.45 (±1.28) and 5.18 (±1.21) (p=0.048), ESR, 41 and 38.7mmHg; and HAQ, 1.2 and 1.0. Improvement was observed in all parameters, with no significant differences (except for a more marked reduction in ESR with RTX). There were no serious adverse events. CONCLUSIONS: RTX use as second-line therapy after anti-TNF failure led to improvements in the efficacy and functional variables at 6 months, with no serious adverse events. These results were comparable to those observed in patients who used a second anti-TNF agent in the same clinical scenario.

AFLPs reveal different population genetic structure under contrasting environments in the marine snail Nucella lapillus L.

Dispersal has received growing attention in marine ecology, particularly since evidence obtained with up-to-date techniques challenged the traditional view. The dogwhelk Nucella lapillus L., a sedentary gastropod with direct development, is a good example: dispersal was traditionally assumed to be limited until studies with microsatellites disputed this idea. To shed some light on this controversy, the genetic structure of dogwhelk populations in northwest Spain was investigated with highly polymorphic AFLP markers giving special attention to the influence of hydrodynamic stress. In agreement with the expectations for a poor disperser, our results show a significant genetic structure at regional (<200 km) and areal scales (<15 km). However, the spatial genetic structure varied with wave-exposure in the present case study: IBD was evident under sheltered conditions but absent from the exposed area where genetic differentiation was stronger. Our results provide evidence that differences in wave-exposure can exert a detectable influence on the genetic structure of coastal organisms, even in species without a planktonic larva.

Population structure and range expansion: the case of the invasive gastropod Cyclope neritea in northwest Iberian Peninsula.

Biotic invasions have a reputation for unpredictable behavior. Here, we report how slight changes in human activity responsible for the introduction and range expansion of a non-native mollusk have led to detectable differences in the genetics of the invasion. Cyclope neritea is a non-predatory gastropod introduced to 2 areas of the European Atlantic: the northwest Iberian Peninsula (NWIP) and the French Atlantic coast (FAC). Shellfish seabed farming is intense in both areas but focuses on different commercial species. Using mitochondrial gene sequences, the lower genetic diversity recorded along the NWIP suggests a more homogeneous range of source populations than in the FAC. Unlike FAC, genetic diversity and haplotype composition in the NWIP correlate with the date of first occurrence of C. neritea at each site rather than with geographical location. Although this pattern evokes the genetic signature expected under a serial-founder colonization model from a single initial enclave, a comparison with samples from potential source populations suggests that the NWIP probably experienced several independent reintroductions. The jump dispersal pattern of C. neritea in the NWIP, together with the observation that populations established in the same year are genetically undifferentiated, point to human transport as the most plausible explanation for the current range expansion. Despite evidence for human-mediated dispersal, C. neritea managed to develop a seemingly non-random genetic pattern in the NWIP. It is suggested that caution must be exerted when interpreting genetic patterns in invaders.

MULTISCALE GENETIC STRUCTURE OF AN ENDANGERED SEAWEED AHNFELTIOPSIS PUSILLA (RHODOPHYTA): IMPLICATIONS FOR ITS CONSERVATION(1).

Although marine macroalgae have recently entered the lists of endangered species, conservation efforts are still limited by a lack of data, particularly for naturally rare species. One example is the turf-forming Ahnfeltiopsis pusilla (Mont.) P. C. Silva et DeCew. Albeit cataloged as vulnerable in the Northwest Iberian Peninsula (NWIP), where it occurs only at five enclaves separated by 1,200 km from the closest recorded presence of the species, nothing is known about its genetic diversity and population connectivity. We used amplified fragment length polymorphism (AFLP) and sequences of the intergenic region between the mitochondrial cytochrome oxidase subunit 2 and subunit 3 genes (cox2-3) to investigate its genetic structure at large (1,200 km), regional (<125 km), fine (<250 m), and patch (<1 m) scales. While cox2-3 variability was too low for the intraspecific study, AFLP revealed that most of the genetic diversity was due to differences between populations. Locally, genetic diversity was always low, and clones were frequent, suggesting that asexual reproduction may be common; patches of turf, however, often were composites of various genetic individuals. Genetic structure at local, regional, and large scales indicated that A. pusilla is a poor disperser, and an assignment test found no evidence of real-time dispersal between NWIP sites. Therefore, it is proposed that the five NWIP enclaves are designated independent management units (MUs). Bayesian-clustering approaches suggested that the three southernmost sites are particularly valuable for conservation since they concentrate most of the genetic heritage of A. pusilla in NWIP. Our study shows that the approaches of conservation genetics may provide useful insights for endangered seaweeds.

MICROSATELLITE DEVELOPMENT IN RHODOPHYTA USING HIGH-THROUGHPUT SEQUENCE DATA(1).

Shotgun genome sequencing is rapidly emerging as the method of choice for the identification of microsatellite loci in nonmodel organisms. However, to the best of our knowledge, this approach has not been applied to marine algae so far. Herein, we report the results of using the 454 next-generation sequencing (NGS) platform to randomly sample 36.0 and 40.9 Mbp (139,786 and 139,795 reads, respectively) of the genome of two red algae from the northwest Iberian Peninsula [Grateloupia lanceola (J. Agardh) J. Agardh and a still undescribed new member of the family Cruoriaceae]. Using data mining tools, we identified 4,766 and 5,174 perfect microsatellite loci in 4,344 and 4,504 sequences/contigs from G. lanceola and the Cruoriaceae, respectively. After conservative removal of potentially problematic loci (redundant sequences, mobile elements), primer design was possible for 1,371 and 1,366 loci, respectively. A survey of the literature indicates that microsatellite density in our Rhodophyta is at the low end of the values reported for other organisms investigated with the same technology (land plants and animals). A limited number of loci were successfully tested for PCR amplification and polymorphism finding that they may be suitable for population genetic studies. This study demonstrates that random genome sequencing is a rapid, effective alternative to develop useful microsatellite loci in previously unstudied red algae.

[What is the real incidence of falls in hospitals?]. / ¿Cuál es la incidencia de caídas real en un hospital?

AIMS: To determine the incidence of falls at acute hospital level and to compare this incidence with that found in the observational study with the notified falls. METHOD: We used a prospective observational study to register patient falls, with daily follow-up in the medical-surgical hospital units, and reviewed the notification of falls records. The patient monitoring was conducted between December 2008 and March 2009 at Fuenlabrada University Hospital. The accumulated incidence of falls was calculated, the association between qualitative variables, and the validity of the notification of falls record with regards to the reference pattern, the observational study. RESULTS: A follow-up has been completed 1,001 patients, finding an accumulated incidence of 1.6% of the followed-up patients, compared to a notified incidence of 0.9%. No statistically significant differences were found (P=.167. The notification of falls record had a Kappa index of 0.24, with a sensitivity of 18.75% and a specificity of 99.39%, compared to the reference, the observational study. CONCLUSION: The incidence of falls practically doubles when using data from observational studies as opposed to those from notification systems.

Comparative effectiveness of rituximab in combination with either methotrexate or leflunomide in the treatment of rheumatoid arthritis.

OBJECTIVE: To compare the effectiveness and safety of a combination of rituximab (RTX) with either methotrexate (MTX) or leflunomide (LEF) in the treatment of patients with active rheumatoid arthritis (RA) and inadequate response to anti-tumor necrosis factor agents or traditional disease-modifying antirheumatic drugs (DMARD) in a real-world setting. METHODS: Data from 77 consecutive unselected patients with active RA and treated with at least 1 cycle of RTX (1 g × 2 weeks) plus MTX or LEF were retrospectively collected. A comparative study between the 2 combinations of treatment (RTX+MTX and RTX+LEF) was performed at 6 months of follow-up considering 3 outcomes: the improvement of RA disease activity, the evolution of functional disability, and the tolerability and side effect profile. RESULTS: Of the 77 patients, 45 received RTX+MTX and 32 RTX+LEF. At baseline there were no significant differences between the groups in terms of the main clinical and laboratory data, or in the number of previous DMARD and anti-tumor necrosis factor agents used. At 6 months of follow-up, we did not find significant differences between the 2 combinations in the evolution of RA disease activity (DAS28 response, according to the European League Against Rheumatism (EULAR) improvement criteria) and functional disability progression (health assessment questionnaire) over time. Minor adverse events occurred in 9% of RTX+MTX patients and in 9% of RTX+LEF patients. None of the patients had serious adverse events and none discontinued the treatment during the study period. CONCLUSIONS: Our preliminary data support the view that LEF is a useful alternative if MTX is contraindicated, since its effectiveness and safety seem similar.

Interrelación del equilibrio tromboxano A2-prostaciclina y su modificación cuando se ingiere aspirina / Interrelation of the balance tromboxano A2-prostaciclina and its modification when aspirin is ingested

Introducción: la aspirina, es usada por su acción antiinflamatoria, analgésica, antipirética y antiagregante plaquetaria. El conocimiento del metabolismo del ácido araquidónico es fundamental para el estomatólogo que basa su trabajo en diagnosticar y tratar procesos inflamatorios en tejidos bucodentales, también por su condición de cirujano debe estar alerta en no realizar intervenciones quirúrgicas en pacientes que estén tomando aspirina, por interrumpir este medicamento la agregación plaquetaria, importante paso de la hemostasia normal. Objetivo: interpretar la interrelación hemostática del tromboxano A2 y la prostaciclina en condiciones fisiológicas, y el resultado de su modificación cuando se ingiere aspirina. Método: PubMed fue empleada como fundamental fuente de búsqueda, que incluyó el conocimiento sobre el fármaco aspirina, la interacción del tromboxano y la prostaclina, y la acción que sobre el equilibrio de estos productos ejerce la aspirina; también se revisaron HINARI, LILACS y Medline. Desarrollo: el ácido araquidónico es un ácido graso poliinsaturado de 20 átomos de carbono (ácido 5, 8, 11, 14-eicosatetraenoico) que procede directamente de la dieta. La relación recíproca entre PG-I2 y el TxA2 constituye un mecanismo finamente equilibrado que sirve para regular la función plaquetaria del ser humano. La utilidad de la aspirina en los pacientes expuestos a trombogénesis se debe, en gran parte, a su capacidad para inhibir la síntesis del TxA2, agente derivado del ácido araquidónico, elemento que se encuentra esterificado a los fosfolípidos de la membrana plaquetaria. El óxido nítrico, igual que la PG-I2, actúa también como vasodilatador e inhibidor de la agregación plaquetaria. Conclusiones: los pacientes que acuden al estomatólogo y por prescripción facultativa están tomando aspirina, tienen su sistema plaquetario inhibido y no pueden sintetizar tromboxano. El proceder quirúrgico por parte del estomatólogo en un paciente que esté ingiriendo aspirina lo expone al desarrollo de hemorragia de causa iatrogénica(AU)

Introduction: aspirin is used by its arachidonic acid is fundamental for the dentist that bases its work on diagnosis and treatment of inflammatory processes, also for its surgeon condition he should be alert to do not carry out surgical interventions in patients that are taking aspirin, because this drug interrupts platelet aggregation, important step of the normal hemostasis. Objective: to interpret the hemostatic interrelation of the tromboxano A2 and the prostaciclina in physiologic conditions and the result of their modification when aspirin is ingested. Method: it was employee as fundamental search source the PubMed, other databases also revised they were HINARI, LILACS, Medline. Was carried out a search that included the knowledge on the drug aspirin, the interaction of the tromboxano and the prostaclina, and the action that it has more than enough the balance of these products it exercises the aspirin. Development: the arachidonic acid is a polyunsaturated fatty acid of 20 atoms of carbon (5, 8, 11, 14-eicosatetraenoic acid) that proceeds directly from diet. The reciprocal relationship between PG-I2 and TxA2 constitutes a finely balanced mechanism that is good to regulate the human being's platelet function. The utility of aspirin in patients exposed to thrombogenesis is largely due to its capacity to inhibit the synthesis of the TxA2, agent derived from arachidonic acid, which is esterified to the phospholipids of the platelet membrane. Nitric oxide, the same as the PG-I 2, also acts as vasodilator and inhibitor of the platelet aggregation. Conclusions: the patients that go to the dentist and for medical prescription are taking aspirin, have their platelet system inhibited and cannot synthesize tromboxane. Surgical processes performed by the dentist in a patient that is ingesting aspirin exposes him to the development of hemorrhage of yatrogenic cause(AU)

Fungicidal activity of Eucalyptus tereticornis essential oil on the pathogenic fungus Fusarium oxysporum / Actividad antimicótica del aceite esencial a partir de Eucalyptus tereticornis sobre el hongo patógeno Fusarium oxysporum

The objective of present paper was to determine the antifungal activity of the Eucalyptus tereticornis (Myrtaceae) essential oil and two fractions on the Fusarium oxysporum mushroom, a pathogen with clinical and agricultural significance. The total citronelal (44.8 percent) and geraniol (9.78 percent) essential oil had a fungicidal effect at a 3 g/L concentration and a fungicidal activity at small concentrations. The A and B fractions composed most of p-mentane-3,8-diol (18.95 percent) and geraniol acetate (24.34 percent), respectively were more active than the total extract. The observations at microscopic level showed damages and changes in hyphae and chlamydospores, as well as a decrease in the number of conidia. The observed fungicidal activity and the morphologic damages were dependent on the concentration.

El objetivo de este trabajo fue determinar la actividad antifúngica del aceite esencial de Eucalyptus tereticornis (Myrtaceae) y 2 fracciones sobre el hongo Fusarium oxysporum, patógeno de importancia tanto clínica como agrícola. El aceite esencial total, compuesto principalmente por citronelal (44,8 por ciento), citronelol (9,78 por ciento) presentó un efecto fungicida a una concentración de 3 g/L y actividad fungistática a concentraciones menores. La fracciones A y B compuestas en su mayoría por p-mentano-3,8-diol (18,95 por ciento) y acetato de citronelol (24,34 por ciento) respectivamente fueron más activas que el extracto total. Las observaciones a nivel microscópico mostraron daños y cambios en hifas y clamidosporas, así como disminución en el número de conidias. La actividad fungistática observada y los daños morfológicos fueron dependientes de la concentración.

Complicaciones de la colostomia / Complications of the colostomy

Se realiza un análisis retrospectivo en el Hospital "Miguel Pérez Carreño" de 75 casos quienes se les practicó colostomía durante el período de tiempo comprendido entre 1982 y 1985. El 56% de ellos corresponden al sexo masculino y 44% al sexo femenino (33 casos), siendo su mayor incidencia en los rangos de edades 50 a 59 años y 20 a 39 años. Las causas que originaron el ingreso inicial del paciente fueron, entre otras, heridas por arma de fuego, neoplasias de colon y recto, trauna ano-rectal, etc. La colostomía más utilizada fue la transversa derecha en asa; se verificó un porcentaje de complicaciones del 38,6%, siendo la infección de la herida operatoria lo más frecuente. No se registró muertes debidas al procedimiento

Amputación del miembro inferior por encima de la rodilla: una revisión crítica / Above knee amputation of the lower extremity: a critical review

Se hace la presentación de 27 pacientes con edades comprendidas entre los 16 y los 105 años, a quienes se les practicó amputación del miembro inferior por encima de la rodilla por diferentes causas, siendo la más frecuente la arteriosclerosis asociada o no a la Diabetes Mellitus. Todos estos pacientes fueron admitidos y atendidos por los Servicios Quirúrgicos del Hospital "Miguel Pérez Carreño" desde enero de l982 hasta diciembre de 1984. Se estudiaron las causas, indicaciones, uso o no de drenajes, complicaciones, evolución post-operatoria, reintervenciones y estancia hospitalaria. También se hacen referencias, consideraciones y análisis de la historia, indicaciones, selección del nivel de amputación y tipos de amputación