IMpassion132 double-blind randomised phase III trial of chemotherapy with or without atezolizumab for early relapsing unresectable locally advanced or metastatic triple-negative breast cancer.

BACKGROUND: Immune checkpoint inhibitors improve the efficacy of first-line chemotherapy for patients with programmed death-ligand 1 (PD-L1)-positive unresectable locally advanced/metastatic triple-negative breast cancer (aTNBC), but randomised data in rapidly relapsing aTNBC are scarce. PATIENTS AND METHODS: IMpassion132 (NCT03371017) enrolled patients with aTNBC relapsing <12 months after last chemotherapy dose (anthracycline and taxane required) or surgery for early TNBC. PD-L1 status was centrally assessed using SP142 before randomisation. Initially patients were enrolled irrespective of PD-L1 status. From August 2019, enrolment was restricted to PD-L1-positive (tumour immune cell ≥1%) aTNBC. Patients were randomised 1:1 to placebo or atezolizumab 1200 mg every 21 days with investigator-selected chemotherapy until disease progression or unacceptable toxicity. Stratification factors were chemotherapy regimen (carboplatin plus gemcitabine or capecitabine monotherapy), visceral (lung and/or liver) metastases and (initially) PD-L1 status. The primary endpoint was overall survival (OS), tested hierarchically in patients with PD-L1-positive tumours and then, if positive, in the modified intent-to-treat (mITT) population (all-comer patients randomised pre-August 2019). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR) and safety. RESULTS: Among 354 patients with rapidly relapsing PD-L1-positive aTNBC, 68% had a disease-free interval of <6 months and 73% received carboplatin/gemcitabine. The OS hazard ratio was 0.93 (95% confidence interval 0.73-1.20, P = 0.59; median 11.2 months with placebo versus 12.1 months with atezolizumab). mITT and subgroup results were consistent. Median PFS was 4 months across treatment arms and populations. ORRs were 28% with placebo versus 40% with atezolizumab. Adverse events (predominantly haematological) were similar between arms and as expected with atezolizumab plus carboplatin/gemcitabine or capecitabine following recent chemotherapy exposure. CONCLUSIONS: OS, which is dismal in patients with TNBC relapsing within <12 months, was not improved by adding atezolizumab to chemotherapy. A biology-based definition of intrinsic resistance to immunotherapy in aTNBC is urgently needed to develop novel therapies for these patients in next-generation clinical trials.

Plectin dysfunction in neurons leads to tau accumulation on microtubules affecting neuritogenesis, organelle trafficking, pain sensitivity and memory.

AIMS: Plectin, a universally expressed multi-functional cytolinker protein, is crucial for intermediate filament networking, including crosstalk with actomyosin and microtubules. In addition to its involvement in a number of diseases affecting skin, skeletal muscle, heart, and other stress-exposed tissues, indications for a neuropathological role of plectin have emerged. Having identified P1c as the major isoform expressed in neural tissues in previous studies, our aim for the present work was to investigate whether, and by which mechanism(s), the targeted deletion of this isoform affects neuritogenesis and proper nerve cell functioning. METHODS: For ex vivo phenotyping, we used dorsal root ganglion and hippocampal neurons derived from isoform P1c-deficient and plectin-null mice, complemented by in vitro experiments using purified proteins and cell fractions. To assess the physiological significance of the phenotypic alterations observed in P1c-deficient neurons, P1c-deficient and wild-type littermate mice were subjected to standard behavioural tests. RESULTS: We demonstrate that P1c affects axonal microtubule dynamics by isoform-specific interaction with tubulin. P1c deficiency in neurons leads to altered dynamics of microtubules and excessive association with tau protein, affecting neuritogenesis, neurite branching, growth cone morphology, and translocation and directionality of movement of vesicles and mitochondria. On the organismal level, we found P1c deficiency manifesting as impaired pain sensitivity, diminished learning capabilities and reduced long-term memory of mice. CONCLUSIONS: Revealing a regulatory role of plectin scaffolds in microtubule-dependent nerve cell functions, our results have potential implications for cytoskeleton-related neuropathies.

Current and emerging avenues for Alzheimer's disease drug targets.

Alzheimer's disease (AD), the most frequent cause of dementia, is escalating as a global epidemic, and so far, there is neither cure nor treatment to alter its progression. The most important feature of the disease is neuronal death and loss of cognitive functions, caused probably from several pathological processes in the brain. The main neuropathological features of AD are widely described as amyloid beta (Aß) plaques and neurofibrillary tangles of the aggregated protein tau, which contribute to the disease. Nevertheless, AD brains suffer from a variety of alterations in function, such as energy metabolism, inflammation and synaptic activity. The latest decades have seen an explosion of genes and molecules that can be employed as targets aiming to improve brain physiology, which can result in preventive strategies for AD. Moreover, therapeutics using these targets can help AD brains to sustain function during the development of AD pathology. Here, we review broadly recent information for potential targets that can modify AD through diverse pharmacological and nonpharmacological approaches including gene therapy. We propose that AD could be tackled not only using combination therapies including Aß and tau, but also considering insulin and cholesterol metabolism, vascular function, synaptic plasticity, epigenetics, neurovascular junction and blood-brain barrier targets that have been studied recently. We also make a case for the role of gut microbiota in AD. Our hope is to promote the continuing research of diverse targets affecting AD and promote diverse targeting as a near-future strategy.

Connecting the brain cholesterol and renin-angiotensin systems: potential role of statins and RAS-modifying medications in dementia.

Millions of people worldwide receive agents targeting the renin-angiotensin system (RAS) to treat hypertension or statins to lower cholesterol. The RAS and cholesterol metabolic pathways in the brain are autonomous from their systemic counterparts and are interrelated through the cholesterol metabolite 27-hydroxycholesterol (27-OHC). These systems contribute to memory and dementia pathogenesis through interference in the amyloid-beta cascade, vascular mechanisms, glucose metabolism, apoptosis, neuroinflammation and oxidative stress. Previous studies examining the relationship between these treatments and cognition and dementia risk have produced inconsistent results. Defining the blood-brain barrier penetration of these medications has been challenging, and the mechanisms of action on cognition are not clearly established. Potential biases are apparent in epidemiological and clinical studies, such as reverse epidemiology, indication bias, problems defining medication exposure, uncertain and changing doses, and inappropriate grouping of outcomes and medications. This review summarizes current knowledge of the brain cholesterol and RAS metabolism and the mechanisms by which these pathways affect neurodegeneration. The putative mechanisms of action of statins and medications inhibiting the RAS will be examined, together with prior clinical and animal studies on their effects on cognition. We review prior epidemiological studies, analysing their strengths and biases, and identify areas for future research. Understanding the pathophysiology of the brain cholesterol system and RAS and their links to neurodegeneration has enormous potential. In future, well-designed epidemiological studies could identify potential treatments for Alzheimer's disease (AD) amongst medications that are already in use for other indications.

Targeting Alzheimer's disease with gene and cell therapies.

Alzheimer's disease (AD) causes dementia in both young and old people affecting more than 40 million people worldwide. The two neuropathological hallmarks of the disease, amyloid beta (Aß) plaques and neurofibrillary tangles consisting of protein tau are considered the major contributors to the disease. However, a more complete picture reveals significant neurodegeneration and decreased cell survival, neuroinflammation, changes in protein and energy homeostasis and alterations in lipid and cholesterol metabolism. In addition, gene and cell therapies for severe neurodegenerative disorders have recently improved technically in terms of safety and efficiency and have translated to the clinic showing encouraging results. Here, we review broadly current data within the field for potential targets that could modify AD through gene and cell therapy strategies. We envision that not only Aß will be targeted in a disease-modifying treatment strategy but rather that a combination of treatments, possibly at different intervention times may prove beneficial in curing this devastating disease. These include decreased tau pathology, neuronal growth factors to support neurons and modulation of neuroinflammation for an appropriate immune response. Furthermore, cell based therapies may represent potential strategies in the future.

Deproteinization Effectiveness on Occlusal Enamel Surfaces and Resultant Acid Etching Patterns: An in vitro Study.

PURPOSE: The goal of this in vitro study was to identify whether occlusal enamel deproteinization is effective in the removal of organic material in order to obtain quality etching patterns using phosphoric acid (H3PO4) and sodium hypochlorite (NaOCl) compared to phosphoric acid alone. STUDY DESIGN: Nine extracted third permanent molars were polished with pumice and water. Every pit and fissure was evaluated as a unit, resulting in 40 individual units and then these were divided into five treatment groups. The occlusal enamel surface of each group was subjected to the following treatments: Group 1 (C) Control: No treatment; Group 2 (P): Polish and rinse; Group 3 (PD): Polish, rinse, and sodium hypochlorite (NaOCl) 5.25% for 60 seconds; Group 4 (PA): Polish, rinse, and acid etching with H3PO4 37% for 15 seconds; and Group 5 (PDA): Polish, rinse, sodium hypochlorite (NaOCl) 5.25% for 60 seconds, and acid etching with H3PO4 37% for 15 seconds. Results showed no significant statistical difference in the organic material present between groups 1 (C) (30.18%) and 2 (P) (36.61%), but there was a statistical difference (p <0.002) between Groups 1 and 2, and Group 3 (PD) (16.50%). In the acid etching group, the undesirable Type-III pattern (discussed later) was found in Group 4 (PA) (33.54%), while this was only 7.70% in Group 5, nearly five times more than Group 4, with a significant statistical difference (0.05). When differences were sought for Types I and II etch patterns (discussed later) for Groups 4 and 5, Group 4 (PA) obtained 26.29% (Type I) and 1.75% (Type II) etch patterns, compared to Group 5 (PDA) with 33.4% (Type I) and 38.97% (Type II) etch patterns. CONCLUSIONS: The enamel deproteinization technique is an effective way to remove organic material on the occlusal surfaces of teeth, obtaining after phosphoric acid application, up to 72.38% of Types I and II etch patterns. Etching Types I or II can also be determined by the removal of organic material in between enamel crystals.

Phylogenetic turnover along local environmental gradients in tropical forest communities.

While the importance of local-scale habitat niches in shaping tree species turnover along environmental gradients in tropical forests is well appreciated, relatively little is known about the influence of phylogenetic signal in species' habitat niches in shaping local community structure. We used detailed maps of the soil resource and topographic variation within eight 24-50 ha tropical forest plots combined with species phylogenies created from the APG III phylogeny to examine how phylogenetic beta diversity (indicating the degree of phylogenetic similarity of two communities) was related to environmental gradients within tropical tree communities. Using distance-based redundancy analysis we found that phylogenetic beta diversity, expressed as either nearest neighbor distance or mean pairwise distance, was significantly related to both soil and topographic variation in all study sites. In general, more phylogenetic beta diversity within a forest plot was explained by environmental variables this was expressed as nearest neighbor distance versus mean pairwise distance (3.0-10.3 % and 0.4-8.8 % of variation explained among plots, respectively), and more variation was explained by soil resource variables than topographic variables using either phylogenetic beta diversity metric. We also found that patterns of phylogenetic beta diversity expressed as nearest neighbor distance were consistent with previously observed patterns of niche similarity among congeneric species pairs in these plots. These results indicate the importance of phylogenetic signal in local habitat niches in shaping the phylogenetic structure of tropical tree communities, especially at the level of close phylogenetic neighbors, where similarity in habitat niches is most strongly preserved.

Detection of hotspots and rapid determination of methane emissions from landfills via a ground-surface method.

We present a method for the rapid determination of methane emissions from landfills based on atmospheric dispersion theory, which suggests that the methane concentration, at a small distance from the soil/atmosphere interface, is proportional to its flux. Thus, after suitable calibration, the determination of methane concentrations close to the ground allows for flux determination in a shorter time than with standard enclosure techniques. This concept was tested using a surface probe in direct contact with the ground. The probe extracts a continuous sample of the air at the probe/ground interface and transports it to a portable methane analyzer. It was observed that stable methane concentrations were measured 30 s after the probe was positioned at the measurement point. These concentrations correlated well with the fluxes measured by standard static chambers. The method was used to determine the fluxes at 217 points within a 90,000 m(2) landfill. These measurements facilitated mapping of the CH4 emissions and the localization of hotspots. We conclude that the method is simple, effective, and relatively quick, compared to existing standard methods.

Habitat filtering across tree life stages in tropical forest communities.

Tropical tree communities are shaped by local-scale habitat heterogeneity in the form of topographic and edaphic variation, but the life-history stage at which habitat associations develop remains poorly understood. This is due, in part, to the fact that previous studies have not accounted for the widely disparate sample sizes (number of stems) that result when trees are divided into size classes. We demonstrate that the observed habitat structuring of a community is directly related to the number of individuals in the community. We then compare the relative importance of habitat heterogeneity to tree community structure for saplings, juveniles and adult trees within seven large (24-50 ha) tropical forest dynamics plots while controlling for sample size. Changes in habitat structuring through tree life stages were small and inconsistent among life stages and study sites. Where found, these differences were an order of magnitude smaller than the findings of previous studies that did not control for sample size. Moreover, community structure and composition were very similar among tree sub-communities of different life stages. We conclude that the structure of these tropical tree communities is established by the time trees are large enough to be included in the census (1 cm diameter at breast height), which indicates that habitat filtering occurs during earlier life stages.

Multispecies coexistence of trees in tropical forests: spatial signals of topographic niche differentiation increase with environmental heterogeneity.

Neutral and niche theories give contrasting explanations for the maintenance of tropical tree species diversity. Both have some empirical support, but methods to disentangle their effects have not yet been developed. We applied a statistical measure of spatial structure to data from 14 large tropical forest plots to test a prediction of niche theory that is incompatible with neutral theory: that species in heterogeneous environments should separate out in space according to their niche preferences. We chose plots across a range of topographic heterogeneity, and tested whether pairwise spatial associations among species were more variable in more heterogeneous sites. We found strong support for this prediction, based on a strong positive relationship between variance in the spatial structure of species pairs and topographic heterogeneity across sites. We interpret this pattern as evidence of pervasive niche differentiation, which increases in importance with increasing environmental heterogeneity.

Prolonged-release pirfenidone in patients with pulmonary fibrosis as a phenotype of post-acute sequelae of COVID-19 pneumonia. Safety and efficacy.

INTRODUCTION: One of the major concerns with post-acute sequelae of COVID-19 (PASC) is the development of pulmonary fibrosis, for which no approved pharmacological treatment exists. Therefore, the primary aim of this open-label study was to evaluate the safety and the potential clinical efficacy of a prolonged-release pirfenidone formulation (PR-PFD) in patients having PASC-pulmonary fibrosis. METHODS: Patients with PASC-pulmonary fibrosis received PR-PFD 1800 mg/day (1200 mg in the morning after breakfast and 600 mg in the evening after dinner) for three months. Blood samples were taken to confirm the pharmacokinetics of PR-PFD, and adverse events (AEs) were evaluated monthly using a short questionnaire. Symptoms, dyspnea, and pulmonary function tests (spirometry, diffusing capacity for carbon monoxide, plethysmography, and 6-min walk test [6MWT]) were evaluated at baseline, and one and three months after having started the PR-PFD treatment. RESULTS: Seventy subjects with mild to moderate lung restriction were included. The most common AEs were diarrhea (23%), heartburn (23%), and headache (16%), for which no modifications in the drug study were needed. Two patients died within the first 30 days of enrolment, and three opted not to continue the study, events which were not associate with PR-PFD. Pulmonary function testing, 6MWT, dyspnea, symptoms, and CT scan significantly improved after three months of treatment with PR-PFD. CONCLUSION: In patients with PASC pulmonary fibrosis, three months' treatment with PR-PFD was safe and showed therapeutic efficacy. Still, it remains to be seen whether the pulmonary fibrotic process remains stable, becomes progressive or will improve.

Short communication: Detection of Shiga toxin-producing Escherichia coli (STEC) in healthy cattle and pigs in Lima, Peru.

The aim of this study was to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) in cattle and pigs as a possible STEC reservoir in Lima, Peru. One hundred and fourteen cattle and 112 pigs from 10 and 4 farms, respectively, were studied. Five E. coli colonies per culture were studied by a multiplex real-time PCR to identify Shiga toxin-producing (stx1, stx2, eaeA), enterotoxigenic (lt, st), enteropathogenic (eaeA), enteroinvasive (ipaH), enteroaggregative (aggR), and diffusely adherent E. coli (daaD). Shiga toxin-producing E. coli were isolated from 16 cattle (14%) but none from pigs. stx1 was found in all bovine isolates, 11 of which also carried eaeA genes (69%); only 1 sample had both stx1 and stx2. Thirteen stx-positive strains were classified as Shiga-toxigenic (81%) using an enzymatic immunoassay, 2 STEC strains were from serogroup O157 (13%), and 7 were sorbitol negative (44%). Enteropathogenic E. coli were detected more frequently in cattle (18%, 20/114) than in pigs (5%, 6/112). To our knowledge, this is the first study on the prevalence of STEC in farms animals in Peru using molecular methods. Further studies are needed in a large number of farms to determine the relevance of these findings and its consequences for public health.

Dentistry for Mexicans with special needs: a commentary.

There are more than 2 million residents with disabilities in Mexico. Despite national legislation to assure individuals with disabilities needed services, including education and employment, social inclusion of these individuals is difficult since societal views exclude them from functioning as members of a community. While there are no national studies of the dental needs of individuals with disabilities in Mexico, reports of the general population indicate limited use of dental services and the need for increased restorative services. Examples of dental education accreditation standards in other countries are used as models for the improvement in the preparation of dental students to provide services for individual with special needs.

Learning during the pandemic: Perspectives of medical students in Singapore.

The COVID-19 pandemic has significantly disrupted medical education, particularly affecting clinical-year students. Educational institutions often had to halt, shorten or impose significant restrictions on their hospital rotations due to strict infection control and social-distancing guidelines implemented in tertiary healthcare institutions, as well as manpower and logistical constraints amid the pandemic. Thus, distance-based learning platforms such as online lectures and case-based teaching were increasingly adopted in place of bedside and face-to-face tutorials. While interactive virtual case-based discussions are generally useful in imparting clinical reasoning skills to medical students, they are unfortunately not able to fully replicate the experience of clerking, examining and managing real patients in the wards, which is a quintessential process towards building clinical acumen and attaining core clinical competencies. Therefore, for final year medical students who are preparing for their Bachelor of Medicine and Bachelor of Surgery (MBBS) examinations, many are naturally concerned by how learning in this "new normal" may affect their ability to make the transition to become competent junior doctors. As such, we seek to share our learning experiences as the first batch of medical students to have completed our entire final year of clinical education amid the COVID-19 pandemic, and offer 4 practical suggestions to future batches of students on how to adapt and optimise clinical learning under these circumstances: actively engaging in virtual learning, making the most of every clinical encounter, learning how to construct peer teaching/practice sessions, and maintaining physical and psychological well-being.

Achieving "Final Storage Quality" of municipal solid waste in pilot scale bioreactor landfills.

Entombed waste in current sanitary landfills will generate biogas and leachate when physical barriers fail in the future, allowing the intrusion of moisture into the waste mass contradicting the precepts of the sustainability concept. Bioreactor landfills are suggested as a sustainable option to achieve Final Storage Quality (FSQ) status of waste residues; however, it is not clear what characteristics the residues should have in order to stop operation and after-care monitoring schemes. An experiment was conducted to determine the feasibility to achieve FSQ status (Waste Acceptance Criteria of the European Landfill Directive) of residues in a pilot scale bioreactor landfill. The results of the leaching test were very encouraging due to their proximity to achieve the proposed stringent FSQ criterion after 2 years of operation. Furthermore, residues have the same characteristics of alternative waste stabilisation parameters (low BMP, BOD/COD ratio, VS content, SO4(2-)/Cl- ratio) established by other researchers. Mass balances showed that the bioreactor landfill simulator was capable of practically achieving biological stabilisation after 2 years of operation, while releasing approximately 45% of the total available (organic and inorganic) carbon and nitrogen into the liquid and gas phases.

Long term histological response of hemisectioned exposed primary pulps. An in vivo study.

UNLABELLED: THE AIM of this study was to analyze the pulp behavior 17 hemisectioned primary second mandibular molars, exposed into the oral environment. The mesial crown and root portions were extracted after 8 months and analyzed histologically. RESULTS: The cardinal signs such as pain, sensitivity and necrosis were not found in any of these teeth with the exception of one case which had a previous restoration. The formation of pulp polyps, pulp calcifications and pulp obliteration were seen as a normal physio-pathological response. CONCLUSIONS: Exposed pulps, reacted forming pulp polyps and in a similar fashion to exfoliating primary teeth but in an accelerated manner.

A liquid chromatography method using a monolithic column for the determination of corticoids in animal feed and animal feeding water.

An HPLC-DAD method for determining corticoids in calf feed and in animal feeding water samples using a monolithic column has been developed and validated. The method optimization included the study of binary mobile phases of water and acetonitrile. The optimum separation was achieved at 40 degrees C, with acetonitrile:H(2)O 29:71 v/v used as mobile phase and a 3 ml/min flow-rate, which resulted in their separation in about 5 min. Two reported sample procedures were applied to feed and for animal feeding water samples prior to HPLC. Method validation was carried out according to the EU criteria established for quantitative screening methods. The results indicate that this method is highly specific, reproducible and accurate. The proposed method was found to be robust and unaffected by small variations in the extraction procedure and in HPLC conditions. The developed method for the determination of corticoids in feed and water samples was also found to be suitable for different kinds of feeds and waters.

Response to a vaccination schedule with 4 doses of 40 microg against hepatitis B virus in cirrhotic patients evaluated for liver transplantation.

We conducted a retrospective study to evaluate the response to recombinant hepatitis B vaccine after 4 intramuscular doses (40 microg) administered at 0, 1, 2, and 6 months in 157 cirrhotic patients who were liver transplant candidates. Seventeen nonresponders were revaccinated with the same schedule. We studied the association between the following variables and the vaccine response: age, gender, etiology of cirrhosis, diabetes, severity of liver disease (Child-Pugh class and Model for End-Stage Liver Disease [MELD] score), and the number of administered doses. The response rates were: 1 dose, 40% (2/5); 2 doses, 0% (0/7); 3 doses, 32.7% (16/49); and 4 doses, 31.3% (30/96) of patients. The median hepatitis B surface antibody (anti-HBs) titer was 45 mU/mL (range, 11-620 mU/mL). The response rate to revaccination was 41.2% (median anti-HBs titer, 88 mU/mL; range, 18-190 mU/mL). Diabetics showed a lower response rate than nondiabetic patients (17.2% vs 35.3%; P = .046). No association was observed between the response rate to vaccine and the other variables. In conclusion, the response rate to hepatitis B vaccine reached a little more than 30% in cirrhotic patients who received 3 or 4 doses. No higher response rate was observed among patients who received 4 doses. Diabetes was associated with a lower response rate. Anti-HBs seroconversion rates were not associated with the other variables. Revaccination may significantly increase the response rate to hepatitis B vaccine in cirrhotic patients, and may be considered in nonresponders after the third dose. Early vaccination against HBV should be considered in such patients.

Efectividad del bloqueo de nervios cluneales para tratamiento de dolor lumbar crónico / Effectiveness of cluneal nerve block for the treatment of chronic low back pain

Introducción: El dolor lumbar representa una problemática de salud pública ante la discapacidad que genera, sea motora o sensitiva de etiología multifactorial, en la cual el atrapamiento de los nervios cluneales cumple un papel importante, encontrando como una alternativa al dolor por esta patología el manejo intervencionista. El objetivo principal del estudio fue establecer la efectividad del bloqueo de nervios cluneales en dolor lumbar crónico en pacientes mayores de 18 años de dos hospitales de Bogotá.Métodos: Estudio de tipo observacional, retrospectivo, realizado en pacientes diagnosticados con dolor lumbar crónico y signos y síntomas de atrapamiento de nervios cluneales o clunealgía llevados a bloqueo de nervios cluneales en quienes que se evaluó la intensidad del dolor y duración del efecto analgésico en cuatro momentos.Resultados: Se identificaron 45 pacientes; de estos, 11 no presentaban datos de seguimiento. El 93 % (n = 35) de los pacientes presentaron una EVA (escala visual análoga del dolor) mayor a 7 previo al procedimiento, el 28 % (n = 11) presentaron postbloqueo inmediato mejoría del dolor con una EVA menor a 6, en el primer control el 57 % (n = 22) conservaron la mejoría alcanzada, y el 10 % (n = 4) retornó a su estado basal de dolor. En el segundo, el 10 % (n = 4) de los pacientes no presentaron cambios en la intensidad, y el 78,9 % (n = 30) conservaba mejoría en la intensidad del dolor.Conclusiones: El bloqueo de los nervios cluneales es una alternativa vanguardista de manejo transitorio del dolor lumbar crónico que permitirá seleccionar con mayor objetividad los pacientes candidatos a intervencionismo guiado por fluoroscopia. Se propone la realización de estudios mediante estudios tipo III como los ensayos aleatorizados con grupos donde se administre placebo versus mezclas analgésicas en pacientes con clunealgia.(AU)

Introduction: Low back pain represents a public health problem due to the disability it generates, whether motor or sensory, of multifactorial etiology, in which cluneal nerve entrapment plays an important role, finding an alternative to pain from this pathology. interventional management. The main objective of the study was to establish the efficacy of cluneal nerve block in chronic low back pain in patients older than 18 years from two hospitals in Bogotá.Methods: Observational, retrospective study, carried out in patients diagnosed with chronic low back pain and signs and symptoms of cluneal nerve entrapment or clunealgia leading to cluneal nerve block in whom pain intensity and duration of the analgesic effect were evaluated in four moments.Results: 45 patients were identified; of these, 11 did not present follow-up data. 93 % (n = 35) of the patients presented a VAS (visual analogue pain scale) greater than 7 prior to the procedure, 28 % (n = 11) presented immediate post-block pain improvement with a VAS less than 6, 57 % at the first control (n = 22) maintained the improvement achieved, and 10 % (n = 4) returned to their baseline state of pain. In the second, 10 % (n = 4) of the patients did not show changes in intensity, and 78.9 % (n = 30) maintained improvement in pain intensity.Conclusions: Cluneal nerve blocks are an avant-garde alternative for the temporary management of chronic low back pain that will make it possible to more objectively select patients who are candidates for fluoroscopy-guided intervention. Studies are proposed using type III studies such as randomized trials with groups where placebo is administered versus analgesic mixtures in patients with clunealgia.(AU)

Hangman's fracture surgical management with posterior C2-4 fusion: Case description and literature review.

BACKGROUND: Hangman's fractures of the C2 verebrae represent approximately 20% of all cervical fractures. They are challenging cases and there is still no consensus regarding the optimal surgical vs nonoperative treatment. CASE DESCRIPTION: A 40-year-old female presented with a C2 bilateral pars articularis fracture. She exhibited a partial spastic quadriparesis. Computed tomography and magnetic resonance imaging showed a C2 "hangman's" fracture with compromise of the C2-3 intervertebral disk. Adequate reduction of the fracture and subaxial stabilization were achieved utilizing C2 transarticular and C3-4 transfacet screws. CONCLUSIONS: The optimal management of unstable hangman's fractures remains controversial. They represent challenging cases, and new treatment options are available. Here, we successfully utilized a C2 transarticular and C3-4 transfacet screw fusion without neurological sequelae.