Leadership theory and motivation of medical imaging employees

*This literature review explores how transactional, transformational, and charismatic leadership theories might be applied in a typical stressful hypothetical department situation. *Transactional department leaders motivate employees using extrinsic rewards, encouraging them to do what is needed to get the minimal results with no encouragement for higher levels of thinking. *Transformational department leaders motivate employees by transforming their beliefs and values to be more in alignment with the organization's values and goals. This alignment helps create higher levels of intrinsic motivation. *Charismatic leaders exhibit the same behaviors as transformational leaders to motivate employees; however; because of their specific characteristics, their effectiveness can be limited to only times of distress or crisis. The situation in the particular department determines which leadership theory is likely to be most successful.     

Learning and Retaining Normal Radiographic Chest Anatomy: Does Preclinical Exposure Improve Student Performance?

RATIONALE AND OBJECTIVES: Although most would concur that preclinical exposure to radiology is a desirable goal, specific learning objectives have been more difficult to delineate. It is also important to assess what is learned and to determine how well it is retained or "retrievable." This study was developed in an attempt to document the extent to which specific measures of preclinically acquired knowledge may be retained and retrieved for later clinical application. MATERIAL AND METHODS: The Anatomic Structure Identification Quiz (ASIQ, or Quiz), previously described in Feigin et al (Academic Radiology 2005) was administered to 236 medical students at the conclusion of the required second-year course, as a 10-item written Quiz based on a projected frontal and lateral chest image. The 10-item Quiz was also administered to 555 senior medical students (194 of which had been included in previous work) on the first day of the Uniformed Services University of the Health Sciences basic radiology elective. Finally, the identical Quiz was completed by 74 of these 555 senior medical students at the conclusion of the academic portion of the elective, approximately 3 weeks after the administration of the first quiz. RESULTS: The second-year students scored a mean of 7.15 points of a possible 10 points with a standard deviation (SD) of 1.42. The senior students completing the quiz at the beginning of the elective scored an average of 4.42 (SD 1.34) compared to a score of 8.65 (SD 1.24) 3 weeks later. CONCLUSION: Long-term recall of specific radiologic structures learned in the second year of medical school was poor despite evidence documenting good initial (short-term) retention of tested information. However, after a brief review, consisting of the Quiz itself, followed by 3 weeks of general radiology emphasizing abnormal chest imaging, the senior students demonstrated a near doubling of their ability to correctly identify these structures, as well as an improvement compared with scores obtained during the second year. Thus the value of a preclinical course in radiology may be not only to teach principles of radiology and to stimulate interest in the discipline, but also, by repetition and reinforcement, to facilitate and possibly improve later recall and retention of important radiographic material.     

The "hybrid flip-over" technique for anterior leaflet prolapse repair

Repair of the anterior mitral leaflet or bi-leaflet prolapse is technically more demanding than repair of the posterior mitral leaflet. Although several techniques have been proposed for the repair of anterior mitral leaflet prolapse during bi-leaflet repair, practical challenges remain, including the determination of the appropriate length for artificial chords. Herein we describe a novel and reproducible technique for bi-leaflet mitral valve repair, including those with extensive anterior mitral leaflet prolapse.     

Haplotypes of transcription factor 7-like 2 (TCF7L2) gene and its upstream region are associated with type 2 diabetes and age of onset in Mexican Americans

TCF7L2 acts as both a repressor and transactivator of genes, as directed by the Wnt signaling pathway. Recently, several highly correlated sequence variants located within a haplotype block of the TCF7L2 gene were observed to associate with type 2 diabetes in three Caucasian cohorts. We previously reported linkage of type 2 diabetes in the San Antonio Family Diabetes Study (SAFADS) cohort consisting of extended pedigrees of Mexican Americans to the region of chromosome 10q harboring TCF7L2. We therefore genotyped 11 single nucleotide polymorphisms (SNPs) from nine haplotype blocks across the gene in 545 SAFADS subjects (178 diabetic) to investigate their role in diabetes pathogenesis. We observed nominal association between four SNPs (rs10885390, rs7903146, rs12255372, and rs3814573) in three haplotype blocks and type 2 diabetes, age at diagnosis, and 2-h glucose levels (P = 0.001-0.055). Furthermore, we identified a common protective haplotype defined by these four SNPs that was significantly associated with type 2 diabetes and age at diagnosis (P = 4.2 x 10(-5), relative risk [RR] 0.69; P = 6.7 x 10(-6), respectively) and a haplotype that confers diabetes risk that contains the rare alleles at SNPs rs10885390 and rs12255372 (P = 0.02, RR 1.64). These data provide evidence that variation in the TCF7L2 genomic region may affect risk for type 2 diabetes in Mexican Americans, but the attributable risk may be lower than in Caucasian populations.     

Genotype-by-sex interaction on fasting insulin concentration: the HyperGEN study

Recent studies have demonstrated the importance of sex effects on the underlying genetic architecture of insulin-related traits. To explore sex-specific genetic effects on fasting insulin, we tested for genotype-by-sex interaction and conducted linkage analysis of fasting insulin in Hypertension Genetic Epidemiology Network families. Hypertensive siblings and their first-degree relatives were recruited from five field centers. We performed a genome scan for quantitative trait loci influencing fasting insulin among 1,505 European Americans and 1,616 African Americans without diabetes. Sex-stratified linear regression models, adjusted for race, center, and age, were explored. The Mammalian Genotyping Service typed 391 microsatellite markers, spaced roughly 9 cM. Variance component linkage analysis was performed in SOLAR using ethnic-specific marker allele frequencies and multipoint IBDs calculated in MERLIN. We detected a quantitative trait locus influencing fasting insulin in female subjects (logarithm of odds [LOD] = 3.4) on chromosome 2 at 95 cM (between GATA69E12 and GATA71G04) but not in male subjects (LOD = 0.0, P for interaction = 0.007). This sex-specific signal at 2p13.2 was detected in both European-American (LOD = 2.1) and African-American (LOD = 1.2) female subjects. Our findings overlap with several other linkage reports of insulin-related traits and demonstrate the importance of considering complex context-dependent interactions in the search for insulin-related genes.     

Clinicopathologic features and utility of immunohistochemical markers in signet-ring cell adenocarcinoma of the bladder

Signet-ring adenocarcinoma is an aggressive form of primary bladder adenocarcinoma that has been associated with poor outcomes. The utility of immunohistochemical markers in tumors with signet-ring morphology may vary from more typical adenocarcinomas arising at the same location, although this has not been examined in bladder adenocarcinoma. We examined a series of bladder adenocarcinomas to determine the impact of signet-ring cell features on clinical outcomes and immunohistochemical findings. We identified 25 patients with bladder adenocarcinoma, ranging in age from 28 to 78 years (mean, 57 years) and with a male-female ratio of 18:7. Six cases were urachal in origin. Signet-ring cells occurred in 19 of 25 bladder adenocarcinomas (76%) and ranged from 5% to 100% of tumor volume, with most tumors demonstrating more than 60% signet-ring cell differentiation (15/19), when present. Regional lymph node metastases were present in 8 of 19 patients (42%) who underwent cystectomy. The percentage of tumor containing signet-ring cells was significantly associated with the presence of adverse pathologic features (defined as unresectable primary tumor or regional lymph node metastasis, P = .013) and decreased overall survival (P = .034), and the latter remained significant in multivariable analysis after adjusting for positive soft tissue margins (P = .026). A comparison between immunohistochemical markers frequently used to analyze bladder adenocarcinoma demonstrated decreased expression of several markers in signet-ring (n = 9) versus colonic-type (n = 8) morphology, including CDX-2, beta-catenin, and E-cadherin, although these results did not reach statistical significance. In summary, the extent of signet-ring differentiation in bladder adenocarcinoma is associated with worsened survival and higher stage disease; the utility of immunohistochemical analysis in foci consisting of predominant signet-ring cells may be limited, although further studies that address this finding are needed.