69 research outputs found
An Update on Grading of Salivary Gland Carcinomas
Histologic grade is a significant predictor of outcome in salivary gland carcinomas. However, the sheer variety of tumor type and the rarity of these tumors pose challenges to devising highly predictive grading schemes. As our knowledge base has evolved, it is clear that carcinoma ex pleomorphic adenoma is not automatically a high grade tumor as is traditionally suggested. These tumors should be further qualified as to type/grade of carcinoma and extent, since intracapsular and minimally invasive carcinomas ex pleomorphic adenoma behave favorably. The two carcinoma types for which grading schemes are common include adenoid cystic carcinoma and mucoepidermoid carcinoma. Adenoid cystic carcinomas are graded based solely on pattern with solid components portending a worse prognosis. Occasionally, adenoid cystic carcinomas may undergo transformation to pleomorphic high grade carcinomas. This feature confers a high propensity for lymph node metastasis and should thus be reported to alert the clinical team. Mucoepidermoid carcinomas are graded in a three tier fashion based on a constellation of features including cystic component, border, mitoses, anaplasia, and perineural invasion among others. All grading schemes are somewhat cumbersome, intimidating and occasionally ambiguous, but evidence suggests that using a scheme consistently shows greater reproducibility than using an intuitive approach. The intermediate grade category demonstrates the most variability between grading systems and thus the most controversy in management. In the AFIP system intermediate grade tumors cluster with high grade tumors, while in the Brandwein system, they cluster with low grade tumors
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Identifying factors likely to influence compliance with diagnostic imaging guideline recommendations for spine disorders among chiropractors in North America: a focus group study using the Theoretical Domains Framework
Background: The Theoretical Domains Framework (TDF) was developed to investigate determinants of specific clinical behaviors and inform the design of interventions to change professional behavior. This framework was used to explore the beliefs of chiropractors in an American Provider Network and two Canadian provinces about their adherence to evidence-based recommendations for spine radiography for uncomplicated back pain. The primary objective of the study was to identify chiropractors’ beliefs about managing uncomplicated back pain without xrays and to explore barriers and facilitators to implementing evidence-based recommendations on lumbar spine xrays. A secondary objective was to compare chiropractors in the United States and Canada on their beliefs regarding the use of spine x-rays.
Methods: Six focus groups exploring beliefs about managing back pain without x-rays were conducted with a purposive sample. The interview guide was based upon the TDF. Focus groups were digitally recorded, transcribed verbatim, and analyzed by two independent assessors using thematic content analysis based on the TDF.
Results: Five domains were identified as likely relevant. Key beliefs within these domains included the following: conflicting comments about the potential consequences of not ordering x-rays (risk of missing a pathology, avoiding adverse treatment effects, risks of litigation, determining the treatment plan, and using x-ray-driven techniques contrasted with perceived benefits of minimizing patient radiation exposure and reducing costs; beliefs about consequences); beliefs regarding professional autonomy, professional credibility, lack of standardization, and agreement with guidelines widely varied (social/professional role & identity); the influence of formal training, colleagues, and patients also appeared to be important factors (social influences); conflicting comments regarding levels of confidence and comfort in managing patients without x-rays (belief about capabilities); and guideline awareness and agreements (knowledge).
Conclusions: Chiropractors’ use of diagnostic imaging appears to be influenced by a number of factors. Five key domains may be important considering the presence of conflicting beliefs, evidence of strong beliefs likely to impact the behavior of interest, and high frequency of beliefs. The results will inform the development of a theorybased survey to help identify potential targets for behavioral-change strategies
Comparison of Karydakis versus midline excision for treatment of pilonidal sinus disease
Pilonidal sinus disease is associated with a high rate of recurrence and complications. The Karydakis (KAR) method, whereby an asymmetric subcutaneous flap obliterates the anal crease, has been shown to be effective in adults. The goal of this study is to assess the efficacy of the KAR procedure in the operative treatment of children with pilonidal sinus disease compared to those treated via a midline excision (ME). Sixty-eight cases of pediatric pilonidal sinus excision were reviewed over the past 10 years. Data abstracted included surgical approach, complication rate and recurrence rate. Student’s t -test or the Chi square test was used for statistical analysis, with P <0.05 being considered significant. An ME was performed in 44 patients; the KAR method was used in 24 patients. Mean age at diagnosis was 14.4±4.2 years for the ME group compared to 15.7±4.3 years for the KAR patients ( P =0.18). Mean operative time was significantly longer with the KAR method (58.7±25.6 min) compared to 46.3±18.6 for the primary ME ( P =0.04). Despite the increased operative dissection, there was no difference ( P =0.42) in early post-operative complication rates between groups (25% in the KAR group compared to 34.8% in the ME group). Initial drainage of an abscess had no significant effect upon the recurrence/complication rate in either group. Recurrence rate alone was lower in patients operated on via the KAR approach 0% versus 11.0% using the ME ( P =0.153). Recurrence and complication rates were lower for those patients with a pilonidal sinus treated by the KAR method compared to the ME, but the results did not reach significance. In conclusion, this study does show a potential benefit for children treated with the KAR method for pilonidal sinus. This study mimics the data obtained in adult patients and suggests that a larger study is likely to achieve significance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47167/1/383_2005_Article_1543.pd
Morphometrical malignancy grading is a valuable prognostic factor in invasive ductal breast cancer
The aim of the present study is to augment the prognostic power of breast cancer grading by elaboration of quantitative histopathological methods. We focus on the recently introduced morphometrical grading system in which the three grading sub-features of the WHO grading system are evaluated with the help of computerised nuclear morphometry, and quantitative methods for assessing mitotic activity and tubular differentiation. The prognostic value of the morphometrical grading system is now confirmed in a material of 159 cases of invasive ductal breast cancer. In the current material the morphometrical grading system very efficiently predicted the prognosis of breast cancer by dividing the patients into favourable (grade I), intermediate (grade II), and unfavourable (grade III) outcome (P<0.0001). The morphometrical grading system was especially efficient in identifying patients with the most unfavourable outcome. In our material the morphometrical grade III was associated with a 5.4-fold risk of breast cancer death. In light of the present results, the morphometrical grading can be applied to clinical use as an aid in treatment decisions of patients with invasive ductal breast cancer
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Changing behaviour 'more or less'-do theories of behaviour inform strategies for implementation and de-implementation? A critical interpretive synthesis
BACKGROUND: Implementing evidence-based care requires healthcare practitioners to do less of some things (de-implementation) and more of others (implementation). Variations in effectiveness of behaviour change interventions may result from failure to consider a distinction between approaches by which behaviour increases and decreases in frequency. The distinction is not well represented in methods for designing interventions. This review aimed to identify whether there is a theoretical rationale to support this distinction. METHODS: Using Critical Interpretative Synthesis, this conceptual review included papers from a broad range of fields (biology, psychology, education, business) likely to report approaches for increasing or decreasing behaviour. Articles were identified from databases using search terms related to theory and behaviour change. Articles reporting changes in frequency of behaviour and explicit use of theory were included. Data extracted were direction of behaviour change, how theory was operationalised, and theory-based recommendations for behaviour change. Analyses of extracted data were conducted iteratively and involved inductive coding and critical exploration of ideas and purposive sampling of additional papers to explore theoretical concepts in greater detail. RESULTS: Critical analysis of 66 papers and their theoretical sources identified three key findings: (1) 9 of the 15 behavioural theories identified do not distinguish between implementation and de-implementation (5 theories were applied to only implementation or de-implementation, not both); (2) a common strategy for decreasing frequency was substituting one behaviour with another. No theoretical basis for this strategy was articulated, nor were methods proposed for selecting appropriate substitute behaviours; (3) Operant Learning Theory makes an explicit distinction between techniques for increasing and decreasing frequency. DISCUSSION: Behavioural theories provide little insight into the distinction between implementation and de-implementation. Operant Learning Theory identified different strategies for implementation and de-implementation, but these strategies may not be acceptable in health systems. Additionally, if behaviour substitution is an approach for de-implementation, further investigation may inform methods or rationale for selecting the substitute behaviour
An Anomalous Type IV Secretion System in Rickettsia Is Evolutionarily Conserved
Bacterial type IV secretion systems (T4SSs) comprise a diverse transporter family functioning in conjugation, competence, and effector molecule (DNA and/or protein) translocation. Thirteen genome sequences from Rickettsia, obligate intracellular symbionts/pathogens of a wide range of eukaryotes, have revealed a reduced T4SS relative to the Agrobacterium tumefaciens archetype (vir). However, the Rickettsia T4SS has not been functionally characterized for its role in symbiosis/virulence, and none of its substrates are known.Superimposition of T4SS structural/functional information over previously identified Rickettsia components implicate a functional Rickettsia T4SS. virB4, virB8 and virB9 are duplicated, yet only one copy of each has the conserved features of similar genes in other T4SSs. An extraordinarily duplicated VirB6 gene encodes five hydrophobic proteins conserved only in a short region known to be involved in DNA transfer in A. tumefaciens. virB1, virB2 and virB7 are newly identified, revealing a Rickettsia T4SS lacking only virB5 relative to the vir archetype. Phylogeny estimation suggests vertical inheritance of all components, despite gene rearrangements into an archipelago of five islets. Similarities of Rickettsia VirB7/VirB9 to ComB7/ComB9 proteins of epsilon-proteobacteria, as well as phylogenetic affinities to the Legionella lvh T4SS, imply the Rickettsiales ancestor acquired a vir-like locus from distantly related bacteria, perhaps while residing in a protozoan host. Modern modifications of these systems likely reflect diversification with various eukaryotic host cells.We present the rvh (Rickettsiales vir homolog) T4SS, an evolutionary conserved transporter with an unknown role in rickettsial biology. This work lays the foundation for future laboratory characterization of this system, and also identifies the Legionella lvh T4SS as a suitable genetic model
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