Role of neuronavigation in the resection of intracranial arteriovenous malformations

AIM: The aim of this study was to investigate the effect of neuronavigation on the following parameters: "skin incision", "craniotomy", "intraoperative anatomical orientation", "dissection guiding", "localization of the pathological formation", "assessment of the degree of resection" and "duration of surgical procedure" in the resection of intracranial arteriovenous malformations (AVMs) and to specify the indications for application of neuronavigation in the surgical treatment of AVMs. METHODS: Five neuronavigation-assisted resections of intracranial AVMs were performed between March 2003 and December 2005 at the Clinic of Neurosurgery of St. I. Rilsky University Hospital, Medical University, Sofia. The female/male ratio in the series was 2:3 (40%:60%). The patients' mean age was 28.2 +/- 18.27 (range 10 to 56) years. The study was prospective in design. Patients were examined and followed in a standardized manner. RESULTS: Arteriovenous malformations were totally removed in all 5 cases of neuronavigation-assisted resections. We did not observe any morbidity or mortality associated with the method. Neuronavigation allowed precise localization and individual design of the skin incision and craniotomy. Neuronavigation facilitated the surgeon during intraoperative anatomical orientation. Dissection guiding, localization of the formation and assessment of the degree of resection were assessed as markedly useful. This resulted in reduced duration of surgery compared to conventional neurosurgery. CONCLUSIONS: In AVMs resection neuronavigation optimizes surgical approach by visualizing the relationship ofAVMs to the skull and various critical anatomical structures. Deep vessel components and nidus margins, especially in the vicinity of the ventricles can be identified precisely. Neuronavigation can improve the early post-operative results in cerebral AVMs reducing operating time and blood loss.     

Fibroblast Growth Factor 21 as a Marker of Prediabetes in Patients with Non-alcoholic Fatty Liver Disease

BackgroundFibroblast growth factor 21 is a peptide primarily secreted by the liver in response to peroxisome proliferator-activated receptor-α activation which plays an important role in regulating carbohydrate and lipid metabolism. This study investigated the association between fibroblast growth factor 21 and prediabetes in obese patients with non-alcoholic fatty liver disease in adult population.MethodsA total of 85 obese non-alcoholic fatty liver disease patients without (n = 49) and with prediabetes (n = 36) were included. Serum fibroblast growth factor 21 levels were determined by enzyme-linked immunosorbent assay.ResultsHigher fibroblast growth factor 21 serum levels were observed in patients with prediabetes, metabolic syndrome, dyslipidemia, and insulin resistance. There were significant correlations between fibroblast growth factor 21 and waist-to-stature ratio, visceral adiposity index, triglycerides, very low-density lipoproteins, alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), Quantitative Insulin Sensitivity Check Index, and Stumvoll index of insulin sensitivity. Fibroblast growth factor 21 level ≥320 pg/mL was associated with a 4.2-fold higher risk of prediabetes and ≥270 pg/mL for metabolic syndrome approximately 4 times.ConclusionFibroblast growth factor 21 is associated with increased risk for prediabetes, metabolic syndrome, and insulin resistance in obese patients with non-alcoholic fatty liver disease.     

Transmission dynamics of SARS-CoV-2 in British Columbia’s largest school district during the second half of the 2020–2021 school year

ObjectivesTo determine the extent and characteristics of in-school transmission of SARS-CoV-2 and determine risk factors for in-school acquisition of COVID-19 in one of Canada’s largest school districts.MethodsWe conducted a retrospective chart review of all reportable cases of COVID-19 who attended a kindergarten–Grade 12 (K-12) school within the study area between January and June of the 2020–2021 school year. The acquisition source was inferred based on epidemiological data and, when available, whole genome sequencing results. Mixed effects logistic regression was performed to identify risk factors independently associated with in-school acquisition of COVID-19.ResultsOverall, 2877 cases of COVID-19 among staff and students were included in the analysis; of those, 9.1% had evidence of in-school acquisition. The median cluster size was two cases (interquartile range: 1). Risk factors for in-school acquisition included being male (adjusted odds ratio [aOR]: 1.59, 95% confidence interval [CI]: 1.17–2.17), being a staff member (aOR: 2.62, 95% CI: 1.64–4.21) and attending or working in an independent school (aOR: 2.28, 95% CI: 1.13–4.62).ConclusionIn-school acquisition of COVID-19 was uncommon during the study period. Risk factors were identified in order to support the implementation of mitigation strategies that can reduce transmission further.     

Diagnostic value of CYFRA 21-1, CEA, CA 19-9, CA 15-3, and CA 125 assays in pleural effusions: analysis of 116 cases and review of the literature

Levels of tumor markers in pleural effusions may help to establish the diagnosis of pleural malignancy, but the precise diagnostic value of each marker remains unclear. The aim of this study was to assess the diagnostic value of five common pleural fluid tumor markers, carcinoembryonic antigen (CEA), cytokeratin fragment (CYFRA) 21-1, cancer antigen (CA) 15-3, CA 19-9, and CA 125, and to review the literature from the past 15 years. Pleural fluid samples were collected prospectively from 116 patients and assayed for CEA, CYFRA 21-1, CA 15-3, CA 19-9, and CA 125 levels. A MEDLINE search of the English-language literature from the past 15 years was also done. Effusions were classified as benign or malignant on the basis of their definitive pathologic or cytologic diagnoses. The levels of all pleural tumor markers were statistically significantly higher in the malignant group than in the benign group. The marker with the highest accuracy was CEA (85.3%); CA 15-3, CYFRA 21-1, and CA 19-9 had similar accuracies (75.2%, 72.4%, and 71.5%, respectively), and CA 125 had the lowest accuracy (40.5%). On univariate analysis, tumor-marker combinations did not result in a greater accuracy than that of CEA alone. On multivariate logistic regression, CA 15-3 and CYFRA 21-1 were significant predictors of malignancy. Among the nine reports in the literature comparing 11 different tumor markers, CEA, CA 15-3, and CYFRA 21-1 yielded the best results. We conclude that pleural fluid analysis should include CEA for the diagnosis of malignancy. CA 15-3 and CYFRA 21-1 may serve as alternative options.     

Coordinated regulation of the cI and int genes in coliphage λ and specificity of the cII/cIII activators

Expression of the cI (repressor) and int (integrase) genes in the λ lysogenic pathway has been studied by following protein synthesis in uv-irradiated cells. Gene expression following infection by λ⁺, a phage carrying an intact repressor gene, and by λvir, a phage carrying operator mutations with reduced affinity for the repressor, substantiated previous findings on the coordinated regulation of these two genes, and showed that their expression can be dissociated from that of other early genes. Experiments with λ hybrid phages showed that the cII gene products of λimm21 and of λimm22, which are of origin of phages 21 and P22, can activate Int synthesis from P_I of λ origin. Possible homology between the various cII genes is discussed.     

Overview and Spinal Implications of Leg Length Discrepancy: Narrative Review

Leg length discrepancy (LLD) is an underrecognized and prevalent condition among the U.S. population, with effects varying depending on the cause and size of the discrepancy. LLD occurs when the paired lower extremities are unequal in length and can be etiologically classified as functional or structural. Length differences are typically less than 10 mm and asymptomatic or easily compensated for by the patient through self-lengthening or shortening of the lower extremities. Literature review of the etiology, diagnostic modalities, clinical complications, and treatment option for patients with LLD. LLD can be assessed directly through tape measurements or indirectly through palpation of bony landmarks. Imaging modalities, specifically radiography, are more precise and help identify coexistent deformity. Once LLD has been diagnosed, evaluation for potential adverse complications is necessary. Discrepancies greater than 20 mm can alter biomechanics and loading patterns with resultant functional limitations and musculoskeletal disorders, such as functional scoliosis. Functional scoliosis is nonprogressive and involves a structurally normal spine with an apparent lateral curvature, which regresses fully or partially when the LLD is corrected. Long-standing LLD and functional scoliosis often result in permanent degenerative changes in the facet joints and intervertebral discs of the spine. Further understanding of the contribution of LLD in the development of scoliosis and degenerative spine disease will allow for more effective preventative treatment strategies and hasten return to function.