Content analysis of medical students' seminars: a unique method of analyzing clinical thinking.

BACKGROUND: The study of communication skills of Asian medical students during structured Problem-based Learning (PBL) seminars represented a unique opportunity to assess their critical thinking development. This study reports the first application of the health education technology, content analysis (CA), to a Japanese web-based seminar (webinar). METHODS: The authors assigned twelve randomly selected medical students from two universities and two clinical instructors to two virtual classrooms for four PBL structured tutoring sessions that were audio-video captured for CA. Both of the instructors were US-trained physicians. This analysis consisted of coding the students' verbal comments into seven types, ranging from trivial to advanced knowledge integration comments that served as a proxy for clinical thinking. RESULTS: The most basic level of verbal simple responses accounted for a majority (85%) of the total students' verbal comments. Only 15% of the students' comments represented more advanced types of critical thinking. The male students responded more than the female students; male students attending University 2 responded more than male students from University 1. The total mean students' verbal response time for the four sessions with the male instructor was 6.9%; total mean students' verbal response time for the four sessions with the female instructor was 19% (p < 0.05). CONCLUSIONS: This report is the first to describe the application of CA to a multi-university real time audio and video PBL medical student clinical training webinar in two Japanese medical schools. These results are preliminary, mostly limited by a small sample size (n = 12) and limited time frame (four sessions). CA technology has the potential to improve clinical thinking for medical students. This report may stimulate improvements for implementation.

[Investigation of rescued cases with cardiac rupture caused by blunt trauma].

The mortality of cardiac rupture by blunt trauma is so high that quick diagnosis and appropriate treatment are essential for saving patients. Based on 8 such cases rescued in our hospital and on 70 other rescued cases reported in Japan, we review its treatment strategy. Ultrasound examination, particularly focused assessment with sonography for trauma (FAST), was useful for diagnosing traumatic cardiac rupture. It was, however, impossible to detect the exact site of rupture before surgery. Three quarters of the rescued cases suffered from right cardiac rupture and more than 95% of those were treated successfully without extracorporeal circulation. All the cases with multiple cardiac rupture needed cardiopulmonary bypass or percutaneous cardiopulmonary support (PCPS) for their surgeries. And so did a quarter of the cases with left cardiac rupture. The standard treatment strategy seems to be as follows:to release cardiac tamponade as slowly as possible, to set up an extracorporeal circulation for surgery, and to repair the ruptured heart via median sternotomy.

Pharmacological evidence that stalk cell differentiation involves increases in the intracellular Ca(2+) and H(+) concentrations in Dictyostelium discoideum.

Differentiation-inducing factors (DIFs) are required for stalk cell formation in Dictyostelium discoideum. In the present study, in order to support our hypothesis that DIFs may function via increases in [Ca(2+)](c) and [H(+)](c), we investigated the combined effects of 5,5-dimethyl-2,4-oxazolidinedione (DMO, a [H(+)](c)-increasing agent), thapsigargin (Tg) and BHQ ([Ca(2+)](c)-increasing agents) on in vitro stalk cell formation in several strains. DMO, in combination with Tg or BHQ, induced stalk cell formation in a DIF-deficient mutant HM44. Although the rates of stalk cell induction by the drugs were low in the presence of cerulenin (an inhibitor of endogenous DIF production) in HM44 and V12M2 (a wild-type strain), the drugs succeeded in inducing sufficient stalk cell formation when a small amount of DIF-1 was supplied. Furthermore, co-addition of DMO, BHQ and a small amount of DIF-1 also induced sufficient stalk cell formation in AX-4 (an axenic strain) and HM1030 (dmtA(-)) but not in CT15 (dimA(-)). The drugs suppressed spore formation and promoted stalk cell formation in both HM18 (a sporogenous mutant) and 8-bromo-cAMP-stimulated V12M2. The present results suggest that DIFs function, at least in part, via increases in [Ca(2+)](c) and [H(+)](c) in D. discoideum.

Postmortem computed tomographic (PMCT) and postmortem magnetic resonance imaging (PMMRI) demonstration of fatal massive retroperitoneal hemorrhage caused by abdominal aortic aneurysm (AAA) rupture.

We report a case of fatal massive retroperitoneal hemorrhage caused by the rupture of an abdominal aortic aneurysm (AAA) in which postmortem computed tomography (PMCT) and postmortem magnetic resonance imaging (PMMRI) provided clear delineation. In this case, the autopsy imaging system using PMCT and PMMRI was useful as a screening method to determine the cause of death as AAA rupture and became a guide for the subsequent autopsy.

Dictyopyrones, novel alpha-pyronoids isolated from Dictyostelium spp., promote stalk cell differentiation in Dictyostelium discoideum.

Dictyopyrones A and B (DpnA and B), whose function(s) is not known, were isolated from fruiting bodies of Dictyostelium discoideum. In the present study, to assess their function(s), we examined the effects of Dpns on in vitro cell differentiation in D. discoideum monolayer cultures with cAMP. Dpns at 1-20 microM promoted stalk cell formation to some extent in the wild-type strain V12M2. Although Dpns by themselves could hardly induce stalk cell formation in a differentiation-inducing factor (DIF)-deficient strain HM44, both of them dose-dependently promoted DIF-1-dependent stalk cell formation in the strain. In the sporogenous strain HM18, Dpns at 1-20 microM suppressed spore formation and promoted stalk cell formation in a dose-dependent manner. Analogs of Dpns were less effective in affecting cell differentiation in both HM44 and HM18 cells, indicating that the activity of Dpns should be chemical structure specific. It was also shown that DpnA at 2-20 microM dose-dependently suppressed spore formation induced with 8-bromo cAMP and promoted stalk cell formation in V12M2 cells. Interestingly, it was shown by the use of RT-PCR that DpnA at 10 microM slightly promoted both prespore- and prestalk-specific gene expressions in an early phase of V12M2 and HM18 in vitro differentiation. The present results suggest that Dpns may have functions (1) to promote both prespore and prestalk cell differentiation in an early stage of development and (2) to suppress spore formation and promote stalk cell formation in a later stage of development in D. discoideum.

Prespore-to-stalk conversion involves the production of a pathway-specific glycoprotein, wst25, in the cellular slime mould Dictyostelium discoideum.

We have previously identified a stalk-specific wheat germ agglutinin (WGA)-binding protein, wst34, in the cellular slime mould Dictyostelium discoideum [Biochem. Cell Biol. 68 (1990) 699]. Here, we found another stalk-specific WGA-binding protein, wst25, which was detected with two antisera that recognize wst34. Using the two marker proteins, we then analyzed and compared the pathways of prestalk-to-stalk maturation and prespore-to-stalk conversion in vitro and in vivo. Prestalk cells isolated from normally formed slugs can be converted to stalk cells (designated StI) in vitro with 8-bromo-cAMP (Br-cAMP), whereas prespore cells isolated from slugs can be converted to fully vacuolated stalk cells (designated StII) in vitro with Br-cAMP and DIF-1. During the process of prespore-to-stalk conversion, prespore-specific mRNAs, D19 and 2H3, disappeared rapidly, while prestalk-specific mRNAs, ecmA and ecmB, appeared at 2h of incubation and increased thereafter. Most importantly, however, the StII cells thus formed were biochemically different from the StI cells originated from prestalk cells; that is, StI cells expressed wst34 but not wst25, while StII cells expressed wst25 but not wst34. When prespore cells isolated from slugs were allowed to develop on a substratum, they differentiated into spores and stalk cells and formed fruiting bodies, and the stalk cells formed from prespore cells in vivo expressed wst25 but not wst34. The present results indicate that there are two types of stalk cells, StI (prestalk-origin) and StII (prespore-origin), and that wst34 and wst25 are the specific markers for StI and StII, respectively.

STARS, a striated muscle activator of Rho signaling and serum response factor-dependent transcription.

Changes in actin dynamics influence diverse cellular processes and couple the actin-based cytoskeleton to changes in gene transcription. Members of the Rho GTPase family regulate cytoskeletal organization by stimulating actin polymerization and stress fiber formation when activated by extracellular signaling. The transcriptional activity of serum response factor (SRF) is stimulated in response to changes in actin dynamics and Rho signaling, but the proteins that mediate this phenomenon have not been fully identified. We describe a novel, evolutionarily conserved actin-binding protein, called STARS (striated muscle activator of Rho signaling), that is expressed specifically in cardiac and skeletal muscle cells. STARS binds to the I-band of the sarcomere and to actin filaments in transfected cells, where it activates Rho-signaling events. STARS stimulates the transcriptional activity of SRF through a mechanism that requires actin binding and involves Rho GTPase activation. STARS provides a potential mechanism for specifically enhancing Rho-dependent transcription in muscle cells and for linking changes in actin dynamics to gene transcription.