Do personality differences between teachers and learners impact students' evaluations of a surgery clerkship?

OBJECTIVE: Historically, the surgery clerkship at the Indiana University School of Medicine (IUSM) has received poor evaluations from medical students, and the authors of this article hypothesized that this negative feedback may reflect, at least in part, inherent differences in the personality styles of the learners compared with those of the surgery teachers (faculty and residents). Differences between teachers and learners could impede effective communication and impact adversely students' perception of, and satisfaction with, the learning environment. The objective of this study was to compare the inherent personality styles of surgery teachers and medical students. DESIGN: Using the Myers-Briggs Type Indicator (MBTI) to assess personality styles, we administered the instrument to 154 teachers in the surgery department and to 1395 medical students. Aggregate MBTI data for teachers and learners were analyzed based on four dichotomous scales. Chi square tests of independence were performed to examine the relationship between teachers and learners on the MBTI scales. SETTING: The study was undertaken at IUSM, which has been engaged in a process of cultural change for over 10 years, in part to ensure that both the formal curriculum and the learning environment support the development of self-awareness and professionalism among our graduates. RESULTS: We found that teachers were similar to learners on the Introversion/Extraversion scale and dissimilar from learners on the three remaining scales: Sensing/Intuition scale (p < 0.008), Thinking/Feeling scale (p < 0.000), and the Judging/Perceiving scale (p < 0.022). CONCLUSIONS: These results suggest that differences in personality styles may affect the teacher-learner interaction during the surgery clerkship and may influence negatively students' perception of the learning environment.

Interphase FISH demonstrates that human adipose stromal cells maintain a high level of genomic stability in long-term culture.

Human adipose stromal cells (ASCs) reside within the stromal-vascular fraction (SVF) in fat tissue, can be readily isolated, and include stem-like cells that may be useful for therapy. An important consideration for clinical application and functional studies of stem/progenitor cells is their capacity to maintain chromosome stability in culture. In this study, cultured ASC populations and ASC clones were evaluated at intervals for maintenance of chromosome stability. Uncultured SVF (uSVF) cells were included for comparison. G-banded chromosome analysis demonstrated that ASCs are diploid and have a normal karyotype. However since only approximately 20 cells are examined, low levels of chromosome instability would not be detected. To increase detection sensitivity, fluorescence in situ hybridization was employed, to permit chromosome enumeration in larger numbers of interphase cells. Seven cultured ASC populations, two ASC clones and four uSVF samples were examined. Chromosome X and 17 probes identified diploid, tetraploid, and aneuploid interphase cells. Both cultured ASC populations [up to approximately 35 Population Doublings (PDs)] and uSVF cells exhibited a similar level of diploidy (97.8% n = 6,355 and 98.83% n = 1,197, respectively) and numerical abnormalities, suggesting that cultured ASCs are genomically stable and supporting their suitability for transplantation applications. In comparison, cultured primary human chorionic villus cells exhibited marked genomic instability resulting in an 11.6% tetraploidy rate after 8-10 PD. Thus effects of culture on genomic stability may be cell type dependent and should be tested by appropriately scaled interphase fluorescence in situ hybridization analysis in any ex vivo expanded cell population destined for transplantation.

A case of de novo partial tetrasomy of distal 6p and review of the literature.

We report on a 3-year-old girl with bilateral eyelid colobomas, bulbous nose, blepharophimosis, blepharoptosis, sensorineural hearing loss, atrial septal defect, psychomotor retardation, and growth delay. Cytogenetic analysis showed additional material of unknown origin on the short arm of chromosome 8. Whole chromosome paint FISH identified the additional material to originate from chromosome 6. Subtelomeric metaphase FISH analysis detected a bright signal pattern for the 6p subtelomere probe on the derivative 8 as well as two short arm signals for the normal chromosomes 6. Interphase FISH with the 6p subtelomere probe demonstrated four 6p signals. Interestingly, metaphase FISH with a probe for the 8p subtelomere region demonstrated a signal for 8p just proximal to the translocated material. Comparative genomic hybridization studies confirmed tetrasomy of the 6p subtelomere region from 6p25.1 --> 6p25.3. Thus our patient represents the first reported case of "pure" partial tetrasomy 6p, meaning the tetrasomy was not associated with a significant deletion of chromosome arm 8p. We compare here this case with previously reported cases of partial trisomy 6p and the resulting phenotypes.

Clinical outcome and follow-up of the first reported case of Russell-Silver syndrome with the unique combination of maternal uniparental heterodisomy 7 and mosaic trisomy 7.

BACKGROUND: Russell-Silver syndrome (RSS) has been associated with maternal uniparental disomy (UPD) for chromosome 7 although the etiology of the syndrome is still unknown. Cases of RSS associated with maternal UPD7 have involved isodisomies, heterodisomies, and mixed isodisomy with heterodisomy simultaneously. This publication is a follow-up report of the postnatal clinical outcome of the first prenatally suspected case of combined mosaic trisomy 7 with maternal uniparental disomy of chromosome 7 (UPD7). CASE: The diagnosis of RSS in the proband was suspected prenatally because trisomy 7 mosaicism (47,XX,+7[13]/46,XX[19]) and maternal uniparental heterodisomy 7 were both found in amniotic fluid cells. Cord blood karyotype analysis showed only disomic cells (46,XX[50]), whereas postpartum chorionic villus analysis was completely trisomic for chromosome 7 (47,XX,+7[19]). Postnatally, the diagnosis of RSS was confirmed by physical findings, her trisomy 7 mosaicism was confirmed by cytogenetic analysis of her skin biopsy (47,XX,+7[9]/46,XX[20]) and her UPD7 was confirmed on both peripheral blood and skin biopsy using microsatellite markers. During infancy, the proband experienced growth deficiency, persistent hypoglycemia, and psychomotor developmental delay. CONCLUSIONS: Trisomic rescue as a life-saving mechanism, with subsequent chromosomal mosaicism in combination with UPD may occur more frequently in RSS than has been reported. Systematic testing of cases suspected prenatally or postnatally would be informative regarding the individual contribution of each factor. Imprinting, loss of heterozygosity for recessive genes, and mosaicism may explain the short stature, asymmetry, and the variable expression of the phenotype. The contribution of these mechanisms to the syndrome should be evaluated in these cases.

A report of three patients with an interstitial deletion of chromosome 15q24.

Partial monosomy of the q2 region of chromosome 15 has been infrequently reported. Moreover, interstitial deletions involving 15q22-q24 have been described in only nine patients to date. The phenotype of these reported individuals is subject to the extent of the deletion but typically includes altered muscle tone and significant developmental delays. In addition, eye abnormalities, such as strabismus, microphthalmia, or colobomas, ear abnormalities including cleft earlobe and preauricular tags, and urogenital defects are common features. Congenital heart defects, diaphragmatic hernia, abnormalities of the central nervous system, and skeletal anomalies have been reported but appear to be less frequent clinical manifestations. In this report, we describe three new patients with interstitial deletions involving 15q24, two with cryptic deletions identified by fluorescence in situ hybridization (FISH) with a probe for the PML gene and one with a cytogenetically visible deletion of 15q22.3-q24. The clinical presentation of these individuals is similar to those previously described and includes global developmental delays, hypotonia, and genital abnormalities in the males. The identification of these three cases demonstrates that the above clinical features are associated with a new cytogenetic deletion syndrome. Furthermore, we suggest that FISH analysis with a probe for the PML gene be performed in patients with these physical findings.

Clinical and cytogenetic manifestations of subtelomeric aberrations: Report of six cases.

BACKGROUND: Fluorescent subtelomeric probes for the 41 different subtelomeric regions (the p arms of the acrocentric chromosomes were excluded) have been developed over the last 10 years. These probes can detect deletions, duplications, and translocations in the gene-rich subtelomeric regions of human chromosomes, regions where crossing over frequently occurs and where a high number of abnormalities have been found. Recently, commercially produced probes have become available, which has led to the detection of subtelomeric abnormalities in 7.4% of patients with moderate to severe mental retardation (Knight et al., 1999). CASES: We evaluated 43 dysmorphic children with developmental delay and/or mental retardation of unknown etiology and/or autism who were previously assessed for chromosome abnormalities, metabolic disorders, or recognizable dysmorphic syndromes, all of which were ruled out. Of the 43 children tested, 6 (14%) were found to have subtelomeric aberrations. CONCLUSIONS: We recommend that patients with dysmorphic features and mental retardation of unknown etiology who also have a normal standard chromosome analysis should have subtelomeric FISH testing performed earlier in their clinical workup.

Update on late relapse of germ cell tumor: a clinical and molecular analysis.

PURPOSE: Analysis of patients with late relapse (LR) of germ cell tumor (GCT) with reports on clinical characteristics, outcomes, and molecular and cytogenetic features. PATIENTS AND METHODS: Eighty-three patients evaluated at Indiana University from 1993 through 2000 for relapse of GCT more than 2 years from initial therapy were reviewed. Available specimens were investigated for expression of the transcription regulator FoxD3 and apurinic/apyrimidinic endonuclease and the presence of chromosome 12 abnormalities. RESULTS: Median interval from initial presentation to LR was 85 months. Forty-three of 49 LR patients who underwent surgery were rendered disease free (NED), and 20 (46.5%) remain continuously NED. Thirty-two patients received chemotherapy, but only six (18.8%) obtained a complete remission. Five of these patients remain continuously NED after chemotherapy alone, including three who were chemotherapy naïve. Eighteen of these 32 patients were successfully rendered NED by postchemotherapy surgery, and 12 remain continuously NED. Two patients continue on observation with no treatment for their LR. Overall, 69 of the 81 treated patients (85.2%) ultimately achieved an NED state, and 38 (46.9%) remain continuously NED with median follow-up from LR therapy of 24.5 months (range, 1 to 83 months), whereas nine other patients are currently NED after therapy for subsequent relapses. Because of the small numbers of specimens tested, we were unable to draw any definitive conclusions from the molecular and cytogenetic analyses. CONCLUSION: GCT patients require lifetime follow-up. At the time of LR, surgical resection alone remains our preferred therapy.

Genomic rearrangements resulting in PLP1 deletion occur by nonhomologous end joining and cause different dysmyelinating phenotypes in males and females.

In the majority of patients with Pelizaeus-Merzbacher disease, duplication of the proteolipid protein gene PLP1 is responsible, whereas deletion of PLP1 is infrequent. Genomic mechanisms for these submicroscopic chromosomal rearrangements remain unknown. We identified three families with PLP1 deletions (including one family described elsewhere) that arose by three distinct processes. In one family, PLP1 deletion resulted from a maternal balanced submicroscopic insertional translocation of the entire PLP1 gene to the telomere of chromosome 19. PLP1 on the 19qtel is probably inactive by virtue of a position effect, because a healthy male sibling carries the same der(19) chromosome along with a normal X chromosome. Genomic mapping of the deleted segments revealed that the deletions are smaller than most of the PLP1 duplications and involve only two other genes. We hypothesize that the deletion is infrequent, because only the smaller deletions can avoid causing either infertility or lethality. Analyses of the DNA sequence flanking the deletion breakpoints revealed Alu-Alu recombination in the family with translocation. In the other two families, no homologous sequence flanking the breakpoints was found, but the distal breakpoints were embedded in novel low-copy repeats, suggesting the potential involvement of genome architecture in stimulating these rearrangements. In one family, junction sequences revealed a complex recombination event. Our data suggest that PLP1 deletions are likely caused by nonhomologous end joining.