The Effectiveness of Video Technology As an Adjunct to Teach and Evaluate Epidural Anesthesia Performance Skills

Background: Although video review has been used in teaching, it has not been reported for use as an adjunct to teaching anesthesiology residents. The purpose of the prospective, randomized, blinded study was to determine whether teaching with video review improves epidural anesthesia skills of anesthesiology residents.

Methods: Twenty-two second-year (CA-2) anesthesiology residents beginning their first obstetric anesthesia rotation were assigned to video or nonvideo groups. All residents were filmed daily as they placed epidural analgesia. Residents assigned to the video group reviewed their tapes twice a week with an attending anesthesiologist, whereas residents assigned to the nonvideo group never saw their films. Four experienced attending anesthesiologists independently judged videotapes taken on days 1, 15, and 30 and scored the residents for "overall" skill (range of summed overall grades, 0-40), as well as on 13 predetermined criteria.

Results: As determined by kappa coefficients, interrater reliability was high among the judges (k = 0.7-0.8). Residents in the video group improved to a greater degree than residents in the nonvideo group. On day 1, the median overall grades for the video and nonvideo groups were 21 and 12, respectively. By day 15, the corresponding grades had increased to 32 and 24, respectively (P < 0.01). However, overall median grades continued to improve between days 15 and 30 in the video group only (P < 0.01).     

Variable sensitivity to noxious heat is mediated by differential expression of the CGRP gene

Heat sensitivity shows considerable functional variability in humans and laboratory animals, and is fundamental to inflammatory and possibly neuropathic pain. In the mouse, at least, much of this variability is genetic because inbred strains differ robustly in their behavioral sensitivity to noxious heat. These strain differences are shown here to reflect differential responsiveness of primary afferent thermal nociceptors to heat stimuli. We further present convergent behavioral and electrophysiological evidence that the variable responses to noxious heat are due to strain-dependence of CGRP expression and sensitivity. Strain differences in behavioral response to noxious heat could be abolished by peripheral injection of CGRP, blockade of cutaneous and spinal CGRP receptors, or long-term inactivation of CGRP with a CGRP-binding Spiegelmer. Linkage mapping supports the contention that the genetic variant determining variable heat pain sensitivity across mouse strains affects the expression of the Calca gene that codes for CGRPalpha.     

Safety and immunogenicity of a three dose regimen of two tetravalent live-attenuated dengue vaccines in five- to twelve-year-old Thai children

OBJECTIVE: The safety and immunogenicity of tetravalent live-attenuated dengue vaccines after a three dose vaccination series were evaluated in Thai children. METHOD: One hundred three healthy flavivirus-seronegative schoolchildren ages 5 to 12 years were randomized to receive either dengue vaccine containing 3, 2, 1 and 2 log10 of the 50% cell culture infective dose, respectively, of the live-attenuated dengue vaccine serotypes 1, 2, 3 and 4 per dose (F3212; n = 40) or 3, 3, 1 and 3 log10 of the 50% cell culture infective dose (F3313; n = 42) or purified Vero cell rabies vaccine (control group; n = 21) given in a two dose schedule (3 to 5 months apart). A third dose was administered 8 to 12 months after the second dose to 90 subjects. Safety and immunogenicity were evaluated within 28 days after each injection. RESULTS: No serious adverse event related to the vaccines occurred. Most children experienced mild to moderate fever, rash, headache and myalgia occurring within 12 days after Dose 1 and generally lasting 3 days or less. One subject in Group F3212 had a 1-week dengue-like fever. Reactogenicity was minimal after Doses 2 and 3. Transient mild variations in liver enzymes and hematologic indices were noted mainly after Dose 1. After the third dose 89% of the subjects in Group F3212 seroconverted (neutralizing antibody response, > or =10) to all four serotypes, and all children in Group F3313 seroconverted. CONCLUSION: This study demonstrates a moderate although improvable reactogenicity and high seroconversion rates against the four serotypes of dengue after a three dose schedule of tetravalent live-attenuated dengue vaccine in children.     

D-amphetamine-induced hydrogen peroxide production in skeletal muscle is modulated by monoamine oxidase inhibition

The aim of this paper was to study the influence of d-amphetamine administration as a sympathomimetic drug on the synthesis of hydrogen peroxide (H2O2) in mouse soleus muscle and to investigate the modulating effects of pargyline, an inhibitor of monoamine oxidase (MAO) in this context. Charles River mice were assigned to four groups: Control, d-amphetamine treated, pargyline treated, and amphetamine + pargyline treated. Their soleus muscles were removed 0, 15, 30, 60, and 120 min after treatment. The amount of hydrogen peroxide formation within the muscles was estimated using an indirect method. The control data showed a continuous production of hydrogen peroxidase. Pargyline administration lead to an initial increase of H2O2 production that later faded below control levels. Administration of amphetamine finally stimulated H2O2 production much above control levels. When combining amphetamine and pargyline treatment, H2O2 production was accelerated in the initial phase but dropped to control levels at 30 min. It is concluded that in skeletal muscle MAO is an important source of hydrogen peroxide production triggered by amphetamine administration and that this tissue plays a hitherto not described role in oxidizing circulating biogenic monoamines.     

Hepatotoxicity of 3,4-methylenedioxyamphetamine and α-methyldopamine in isolated rat hepatocytes: formation of glutathione conjugates

The amphetamine designer drugs 3,4-methylenedioxymethamphetamine (MDMA or ecstasy) and its N-demethylated analogue 3,4-methylenedioxyamphetamine (MDA or love) have been extensively used as recreational drugs of abuse. MDA itself is a main MDMA metabolite. MDMA abuse in humans has been associated with numerous reports of hepatocellular damage. Although MDMA undergoes extensive hepatic metabolism, the role of metabolites in MDMA-induced hepatotoxicity remains unclear. Thus, the aim of the present study was to evaluate the effects of MDA and -methyldopamine (-MeDA), a major metabolite of MDA, in freshly isolated rat hepatocyte suspensions. The cells were incubated with MDA or -MeDA at final concentrations of 0.1, 0.2, 0.4, 0.8, or 1.6 mM for 3 h. The toxic effects induced following incubation of hepatocyte suspensions with these metabolites were evaluated by measuring cell viability, the extent of lipid peroxidation, levels of glutathione (GSH) and glutathione disulfide (GSSG), the formation of GSH conjugates, and the activities of GSSG reductase (GR), GSH peroxidase (GPX), and GSH S-transferase (GST). MDA induced a concentration- and time-dependent GSH depletion, but had a negligible effect on lipid peroxidation, cell viability, or on the activities of GR, GPX, and GST. In contrast, -MeDA (1.6 mM, 3 h) induced a marked depletion of GSH accompanied by a loss on cell viability, and decreases in GR, GPX and GST activities, although no significant effect on lipid peroxidation was found. For both metabolites, GSH depletion was not accompanied by increases in GSSG levels; rather, 2-(glutathion-S-yl)--MeDA and 5-(glutathion-S-yl)--MeDA were identified by HPLC-DAD/EC within cells incubated with MDA or -MeDA. The results provide evidence that one of the early consequences of MDMA metabolism is a disruption of thiol homeostasis, which may result in loss of protein function and the initiation of a cascade of events leading to cellular damage.     

Leucoisoprenochrome-o-semiquinone formation in freshly isolated adult rat cardiomyocytes

Sustained high levels of circulating catecholamines can lead to cardiotoxicity. There is increasing evidence that this process may result from metal-catalyzed catecholamine oxidation into semiquinones, quinones, and aminochromes. We have previously shown that Cu2+-induced oxidation of isoproterenol into isoprenochrome induces toxic effects in isolated cardiomyocytes. The aim of this study was to characterize the isoproterenol oxidation process and to locate the formation of semiquinone radicals in cardiomyocyte suspensions. Freshly isolated rat cardiomyocytes were incubated with 1 or 10 mM isoproterenol and 20 microM Cu2+ for 4 h. The formation of an isoproterenol oxidation radical was detected in the extracellular medium, cells, membranes, and heavy organelles by electron spin resonance spectroscopy. An electron spin resonance signal assigned to leucoisoprenochrome-o-semiquinone increased in a time-dependent manner in the extracellular medium. A second electron spin resonance signal, characteristic of an immobilized radical, was also found in the cardiomyocytes. The latter was attributed to leucoisoprenochrome-o-semiquinone immobilized on cellular components such as membranes, cytoskeleton, nucleus, and heavy organelles. In addition, the levels of leucoisoprenochrome-o-semiquinone decreased in the presence of glutathione. Computer simulations of the experimental spectra indicate the formation of two distinct isomeric leucoisoprenochrome-o-semiquinone radicals during isoproterenol oxidation. The present study shows that the isoproterenol oxidation in isolated rat cardiomyocytes correlates with the formation of leucoisoprenochrome-o-semiquinone in the cells and in the extracellular medium, suggesting that it might be involved in cardiotoxicity induced by the oxidation of catecholamines.     

Natural host relationships and genetic diversity of Whitewater Arroyo virus in southern Texas

The purpose of this study was to refine our knowledge of the natural host relationships of Whitewater Arroyo (WWA) virus. Two hundred eight rodents, representing nine species, were captured in July 1999 on the Chaparral Wildlife Management Area in southern Texas and tested for evidence of arenavirus infection. Antibody to an arenavirus was found in seven (21.9%) of 32 southern plains woodrats (Neotoma micropus) and none of 168 other rodents. Infectious WWA virus was isolated from four antibody-positive southern plains woodrats, one of 25 antibody-negative southern plains woodrats, and none of 176 other rodents. Collectively, the results indicate that the southern plains woodrat is a principal host of WWA virus in southern Texas. Analyses of viral gene sequence data revealed substantial genetic diversity among WWA virus strains isolated from the woodrats, suggesting that multiple variants of the virus can coexist in a single woodrat species in a small geographic area.     

Human albumin synthesis is increased by an ultra-endurance trial

PURPOSE: The purpose of this study was to determine whether an ultra-endurance event is a strong stimulus to increase albumin synthesis involved in the process of intravascular albumin mass increase associated with transient hypervolemia. METHODS: The albumin synthetic rate was measured in six young men, 3 d before (C) and on the 1st (R1) and 8th (R8) days of the recovery from an ultra-endurance trial (5 h daily for 4 d). Albumin fractional (FSR) and absolute (ASR) synthetic rate were determined using a primed-constant infusion of [1(-13) C] leucine. Plasma volume (PV) using Evans Blue dye dilution and total body water (TBW) using bioelectrical impedance analysis were measured on C, R1, and R8. RESULTS: On R1 as compared with C: 1). PV (+23.3 +/- 3.2%; P相似文献   

Characterization of Hodgkin's lymphoma-like undifferentiated carcinoma of the nasopharyngeal type as a particular UCNT subtype mimicking Hodgkin's lymphoma

Undifferentiated carcinoma of the nasopharyngeal type (UCNT) that histologically mimics Hodgkin's lymphoma (HL) ("Hodgkin's lymphoma-like UCNT"--HL-like UCNT) is known as a diagnostic pitfall. Using immunohistochemistry, Western blot and cDNA array technology, we wanted to document its phenotypical and molecular characteristics. We report herein 5 cases of UCNT that morphologically mimic HL and 3 classical UCNT cases. We compared the expression profiles of a thousand selected genes in HL-like UCNT and in classical UCNT cases. No difference in the profile of EBV infection was noted between the HL-like UCNT and control cases. Significant differences were detected in the expression of genes involved in the matrix modelling, angiogenesis, apoptosis and regulation of the Th-2 interleukins. The eosinophil chemoattractant eotaxin was expressed in the stroma of HL-like UCNT, but not in the control cases. The eotaxin receptor CCR3 was expressed in both stromal and carcinoma cell populations of HL-like UCNT, this pattern being similar to the one observed in HL. These results show that UCNT morphologically resembling HL share also some specific phenotypical and molecular features with HL, and might deserve to be isolated as a particular UCNT subtype.