Implementation of a Web- and simulation-based curriculum to ease the transition from medical school to surgical internship

BACKGROUND: Starting a surgical internship is a stressful experience. We developed a web and simulation-based curriculum to ease this transition. METHODS: We created an educational website containing a curriculum of commonly encountered on call situations. After match day in 2003, we contacted all of our new surgical interns. We performed a confidence assessment using a Likert-scale questionnaire, and the trainees were given access to the curriculum. In June 2003, we performed human patient simulator sessions. The participants were asked to provide feedback regarding the simulator experience. During the first week of residency, they were again asked to answer the confidence questionnaire. RESULTS: Sixteen residents (94%) used the web curriculum, and 17 (100%) participated in the simulations. Eleven (65%) filled out both questionnaires. The confidence score improved from 5.4 to 6.7 (P < .0001). CONCLUSIONS: A web and simulation-based curriculum for incoming house staff is feasible. Studies are underway to validate this novel method and to expand its use for surgical education.     

Congenital teratoma: a clinicopathologic study of 22 fetal and neonatal tumors

Extragonadal teratoma is the most common congenital tumor. The prognostic significance of the grade of immaturity and the presence of small foci of conventional yolk sac tumor (YST) in fetal and neonatal teratomas have not been determined. We report detailed histologic studies of 22 congenital teratomas, including eight tumors resected in utero for developing hydrops, and correlate the histologic features with initial serum alpha-fetoprotein (AFP) levels and clinical outcome. All fetal tumors that required in utero intervention were grade 3 immature teratomas, with admixed conventional YST in 44%. Among tumors resected postnatally, those presenting in utero were more commonly immature (71% vs. 50%). All initial post-surgical serum AFP levels were high, as expected in a neonate. No correlation was found between AFP elevation above the mean for gestational age and the presence of YST, hepatic differentiation, or immature endodermal glands in the tumor. Among 15 survivors with follow-up, 5 patients had malignant mixed germ cell tumors (immature teratoma with foci of conventional YST) and 5 had immature teratomas with foci of hepatic differentiation or immature endodermal glands with subnuclear vacuoles (so-called "well-differentiated YST"). No patient has developed recurrent or metastatic disease after treatment by complete surgical excision alone (mean follow-up, 37.6 months). The clinical behavior of congenital teratomas is determined predominantly by whether or not the tumor can be completely resected and in our study did not correlate with the grade of the teratoma or with the presence or absence of foci of hepatic tissue, immature intestinal glands, or foci of conventional YST.     

Validating three-dimensional imaging of the breast

The potential to extrapolate accurate data from 3-dimensional (3D) images of the breast is enormous and will greatly improve our ability to qualitatively determine differences in shape, size, and contour. The validity of these calculated measurements is important and needs to be determined before any meaningful data can be evaluated. PART I: Premastectomy 3D images (3dMD patient) were obtained on 19 breasts (14 patients). The volume of the mastectomy specimen was determined intraoperatively using water displacement. Two independent raters then calculated breast volumes using the 3D images and software, and these were compared with the intraoperative volume. Inter- and intrarater reliability was determined. Part II: Surface measurements (nipple to notch) were then evaluated on 20 breasts (10 patients) by comparing the 3D image determined distance to the known measurements. PART I: The average breast volume was 500 mL, compared with 489 mL for rater 1 and 490 mL for rater 2. The relative difference between the measured volume and the calculated volume for rater 1 and rater 2 was about -2%, with a standard deviation of +/- 13% to 16%. The coefficient of reproducibility for each reader was excellent, at 0.80 for rater 1 and 0.92 for rater 2. The level of agreement between the readers was also high at 0.975. Part II: The average nipple to notch measurement for each patient was 27.1 cm, compared the calculated average of 25.1 cm for rater 1 and 26.1 cm for rater 2. The mean relative difference between the measured and calculated distances for raters 1 and 2 was about -6%, with a standard deviation of +/- 6% to 7%. The level of agreement between readers was high, at 0.975. The ability to objectively determine breast volume and surface measurements using 3D imaging technology is now available with consistent and reproducible accuracy. Measurements are typically underestimated, with more variability when calculating volumes. Although inherent subjectivity will always exist when evaluating breast measurements, 3D technology provides invaluable information, particularly in the longitudinal evaluation of results.     

The ratio of factor VIII-related antigen and factor VIII biological activity as an index of hypercoagulability and intravascular clotting.

It is suggested that the ratio of factor VIII-related antigen/factor VIII biological activity may be a useful indicator of hypercoagulability or intravascular coagulation, and a measure of the efficacy of steady state anticoagulation.The ratio was shown to progressively increase during normal pregnancy and was significantly greater in preeclampsia. The ratio increased without exception in ten patients following abdominal surgery and was usually maximal after 1 to 3 days. The ratio was raised in patients with thromboembolic disease, and decreased in all patients following treatment with warfarin or heparin. In 26 out of 28 patients on warfarin therapy for more than 10 days, the ratio was still greater than one.     

Attempted replication of reported chronic obstructive pulmonary disease candidate gene associations

Case-control studies have successfully identified many significant genetic associations for complex diseases, but lack of replication has been a criticism of case-control genetic association studies in general. We selected 12 candidate genes with reported associations to chronic obstructive pulmonary disease (COPD) and genotyped 29 polymorphisms in a family-based study and in a case-control study. In the Boston Early-Onset COPD Study families, significant associations with quantitative and/or qualitative COPD-related phenotypes were found for the tumor necrosis factor (TNF)-alpha -308G>A promoter polymorphism (P < 0.02), a coding variant in surfactant protein B (SFTPB Thr131Ile) (P = 0.03), and the (GT)(31) allele of the heme oxygenase (HMOX1) promoter short tandem repeat (P = 0.02). In the case-control study, the SFTPB Thr131Ile polymorphism was associated with COPD, but only in the presence of a gene-by-environment interaction term (P = 0.01 for both main effect and interaction). The 30-repeat, but not the 31-repeat, allele of HMOX1 was associated (P = 0.04). The TNF -308G>A polymorphism was not significant. In addition, the microsomal epoxide hydrolase "fast" allele (EPHX1 His139Arg) was significantly associated in the case-control study (P = 0.03). Although some evidence for replication was found for SFTPB and HMOX1, none of the previously published COPD genetic associations was convincingly replicated across both study designs.     

Early biomarkers of psychosis

Biological traits that are predictive of the later development of psychosis have not yet been identified. The complex, multidetermined nature of schizophrenia and other psychoses makes it unlikely that any single biomarker will be both sensitive and specific enough to unambiguously identify individuals who will later become psychotic. However, current genetic research has begun to identify genes associated with schizophrenia, some of which have phenotypes that appear early in life. While these phenotypes have low predictive power for identifying individuals who will become psychotic, they do serve as biomarkers for pathophysiological processes that can become the targets of prevention strategies. Examples are given from work on the role of the alpha(T)nicotinic receptor and its gene CHRNA7 on chromosome 15 in the neurobiology and genetic transmission of schizophrenia.     

Recall discriminability: utility of a new CVLT-II measure in the differential diagnosis of dementia.

Memory tests that are in a recall format have almost universally measured accuracy in terms of the number of target items reported by the examinee. However, this traditional scoring method can, in certain cases, result in artificially inflated memory accuracy scores. That is, just as a "yes" response bias and high false-positive rate on recognition testing can artificially inflate a patient's hit rate, so, too, a liberal response bias and high intrusion rate on recall testing can artificially inflate a patient's level of target recall. Recognition tests correct for this problem by using a discriminability measure that provides a single score of hit rate relative to false-positive rate; however, recall tests rarely provide a single score of recall accuracy that corrects for intrusion rate. In the present study, we examined the utility of a new recall discriminability measure that analyzes target recall relative to intrusion rate. Patients with Alzheimer's disease (AD) or Huntington's disease (HD) were administered the CVLT-II, which provides both the traditional measure of target recall and a new measure of recall discriminability. The results indicate that the new recall discriminability measure was superior to the traditional level of target recall measure in distinguishing the recall performance of AD and HD patients. Implications of these results for clinical practice and theories of memory disorder in dementia are discussed.     

CT perfusion cerebral blood flow imaging in neurological critical care

Computed tomography (CT) perfusion imaging is a technique for the measurement of cerebral blood flow, cerebral blood volume, and time-to-peak or mean transit time. The technique involves the administration of a single-bolus dose of iodinated contrast material, followed by spiral CT imaging during the passage of the contrast bolus through the cerebral vasculature. CT perfusion is a fast and inexpensive brain imaging modality for use in the management of patients with various neurological disorders, ranging from acute stroke to subarachnoid hemorrhage. This article reviews the technique of CT perfusion and presents several illustrative cases in which this imaging modality was used effectively in the critical care of patients with neurological disorders.