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91.
ObjectiveThere are few opportunities in medical education dedicated to learning skills for effective communication in life altering patient scenarios. We therefore aimed to develop and assess a longitudinal advanced communication curriculum for pediatric residents using patient feedback and deliberate practice.MethodsPediatric residents at a large academic center were randomized into 2 groups. The intervention group received 6 educational sessions from 2019 to 2020, parent feedback of performance via the Communication Assessment Tool (CAT), and monthly communication tips. Communication skills of both groups were assessed at the end of the intervention.ResultsWe collected 937 CAT assessments on 36 first-year residents. The intervention group demonstrated statistically significant improvement in communication skills from pre to post assessment (p = 0.0063, (odds ratio (OR) 1.76, 95 % confidence interval (CI) [1.17, 2.63]) compared to the control group (p = 0.080, OR 1.41, 95 % CI [0.96, 2.05]).ConclusionsThere are patient and self-identified performance gaps in communication skills for pediatric residents, underscoring the need for formalized curricula dedicated to these skills.Practice implicationsOur study highlights the value of deliberate practice and the integration of family feedback as an educational tool in communication skills development.  相似文献   
92.
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a very rare often fatal congenital coronary artery anomaly that occurs in approximately only 1 of 300,000 live births. Many cardiologists and pathologists may be unaware that cardiac ischemia and sudden death can also occur due to ALCAPA in adults in whom it is even rarer and thus may be missed at autopsy. The adult form may range clinically from asymptomatic to sudden cardiac death. We present four cases of adult ALCAPA that illustrate the variable presentations and survival. Two had died at rest and were previously asymptomatic. The other two died during exertion with history of recent chest pains in one and previous myocardial infarction in childhood in the other. This last case remained asymptomatic until death. These four cases highlight that surgery should be undertaken in all cases, even in those who are asymptomatic as newer imaging makes the diagnosis in life more frequent. Age is not important as cases vary widely in age from 22 to 68 in our small group. Furthermore, the most common site of left coronary artery origin is the left pulmonary sinus but our autopsy study shows that the origin can be variable extending above the pulmonary valve sinus to the main pulmonary artery.  相似文献   
93.
PurposeTo develop a fuzzy linguistic model to quantify the level of distress of patients seeking cosmetic surgery. Body dysmorphic disorder (BDD) is a mental condition related to body image relatively common among cosmetic surgery patients; it is difficult to diagnose and is a significant cause of morbidity and mortality. Fuzzy cognitive maps are an efficient tool based on human knowledge and experience that can handle uncertainty in identifying or grading BDD symptoms and the degree of body image dissatisfaction. Individuals who seek cosmetic procedures suffer from some degree of dissatisfaction with appearance.MethodsA fuzzy model was developed to measure distress levels in cosmetic surgery patients based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), diagnostic criterion B for BDD. We studied 288 patients of both sexes seeking abdominoplasty, rhinoplasty, or rhytidoplasty in a university hospital.ResultsPatient distress ranged from “none” to “severe” (range = 7.5–31.6; cutoff point = 18; area under the ROC curve = 0.923). There was a significant agreement between the fuzzy model and DSM-IV criterion B (kappa = 0.805; p < 0.001).ConclusionThe fuzzy model measured distress levels with good accuracy, indicating that it can be used as a screening tool in cosmetic surgery and psychiatric practice.  相似文献   
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96.
Treacher Collins Syndrome (TCS) is the most common of the human mandibulofacial dysostosis disorders. Recently, a partial TCOF1 cDNA was identified and shown to contain mutations in TCS families. Here we present the entire exon/intron genomic structure and the complete coding sequence of TCOF1. TCOF1 encodes a low complexity protein of 1,411 amino acids, whose predicted protein structure reveals repeated motifs that mirror the organization of its exons. These motifs are shared with nucleolar trafficking proteins in other species and are predicted to be highly phosphorylated by casein kinase. Consistent with this, the full-length TCOF1 protein sequence also contains putative nuclear and nucleolar localization signals. Throughout the open reading frame, we detected an additional eight mutations in TCS families and several polymorphisms. We postulate that TCS results from defects in a nucleolar trafficking protein that is critically required during human craniofacial development.  相似文献   
97.
Expression of c-abl in Philadelphia-positive acute myelogenous leukemia   总被引:6,自引:0,他引:6  
The identical cytogenetic marker, t(9;22)(q34;q11) (Philadelphia [Ph] translocation), is found in approximately 90%, 20%, and 2% of adult patients with chronic myelogenous leukemia (CML), acute lymphoblastic leukemia (ALL), and acute myelogenous leukemia (AML), respectively. In CML, the molecular events resulting from the Ph translocation include a break within the bcr locus on chromosome 22, transfer of the c-abl protooncogene from chromosome 9 to 22, and formation of an aberrant 210- kD bcr-abl fusion protein (p210bcr-abl). Recently, the absence of bcr rearrangement and expression of a distinct aberrant 190-kd abl protein (p190c-abl) has been described in Ph-positive ALL, with the suggestion that the two abl variants may be pathogenetically associated with myeloid v lymphoid leukemogenesis. Here we report that the genomic configuration and translation product of Ph-positive AML can be similar to that of Ph-positive ALL: the break at 22q11 may occur outside the 5.8 kb bcr region and result in expression of a 190-kD abl protein lacking these bcr sequences. Phosphokinase enzymatic activity, a fundamental property of p210bcr-abl, was also associated with AML- derived p190c-abl. Our current observations indicate that p190c-abl can be found in cells of lymphoid or myeloid lineage and is therefore unlikely to play a specific role in the development of lymphoid leukemias. Formation of p190c-abl instead of p210bcr-abl appears to be a characteristic of the acute rather than the chronic Ph-positive leukemic state.  相似文献   
98.
Tumoral cells in Hodgkin lymphoma (HL) display an increased growth fraction and diminished apoptosis, implying a profound disturbance of the cell cycle and apoptosis regulation. However, limitations of molecular techniques have prevented the analysis of the tumor suppressor pathways and cell-cycle checkpoints. Tissue microarray (TMA) is a powerful tool for analyzing a large number of molecular variables in a large series of tumors, although the feasibility of this technique has not yet been demonstrated in heterogeneous tumors. The expression of 29 genes regulating the cell cycle and apoptosis were analyzed by immunohistochemistry and in situ hybridization in 288 HL biopsies using TMA. The sensitivity of the technique was validated by comparing the results with those obtained in standard tissue sections. The results revealed multiple alterations in different pathways and checkpoints, including G1/S and G2/M transition and apoptosis. Striking findings were the overexpression of cyclin E, CDK2, CDK6, STAT3, Hdm2, Bcl2, Bcl-X(L), survivin, and NF-kappaB proteins. A multiparametric analysis identified proteins associated with increased growth fraction (Hdm2, p53, p21, Rb, cyclins A, B1, D3, and E, CDK2, CDK6, SKP2, Bcl-X(L), survivin, STAT1, and STAT3), and proteins associated with apoptosis (NF-kappaB, STAT1, and RB). The analysis also demonstrated that Epstein-Barr virus (EBV)-positive cases displayed a characteristic profile, confirming the pathogenic role of EBV in HL. Survival probability depends on multiple biologic factors, including overexpression of Bcl2, p53, Bax, Bcl-X(L), MIB1, and apoptotic index. In conclusion, Hodgkin and Reed-Sternberg cells harbor concurrent and overlapping alterations in the major tumor suppressor pathways and cell-cycle checkpoints. This appears to determine the viability of the tumoral cells and the clinical outcome.  相似文献   
99.
The activation of the renin-angiotensin system (RAS) is an important mechanism that contributes to hypertension in obese individuals. Thiazide diuretics also activate the RAS in response to volume contraction and can lead to a decrease in serum potassium values and glucose metabolism abnormalities. To evaluate the impact of abdominal obesity on potassium depletion and glucose homeostasis in hypertensive patients receiving thiazide therapy, the authors studied 329 hypertensive patients without known diabetes or impaired renal function. Patients were stratified into 2 major groups according to whether they used thiazide diuretic therapy, and each group was further divided in 2 subgroups according to the presence of abdominal obesity. The authors demonstrated that obese patients receiving diuretic therapy had lower plasma potassium levels and higher glucose values compared with nonobese patients receiving diuretic therapy. In conclusion, abdominal obesity predisposes to potassium depletion during diuretic therapy in association with effects on glucose homeostasis.  相似文献   
100.
Enzymes that bear a nonnative or artificially introduced metal center can engender novel reactivity and enable new spectroscopic and structural studies. In the case of metal-organic cofactors, such as metalloporphyrins, no general methods exist to build and incorporate new-to-nature cofactor analogs in vivo. We report here that a common laboratory strain, Escherichia coli BL21(DE3), biosynthesizes cobalt protoporphyrin IX (CoPPIX) under iron-limited, cobalt-rich growth conditions. In supplemented minimal media containing CoCl2, the metabolically produced CoPPIX is directly incorporated into multiple hemoproteins in place of native heme b (FePPIX). Five cobalt-substituted proteins were successfully expressed with this new-to-nature cobalt porphyrin cofactor: myoglobin H64V V68A, dye decolorizing peroxidase, aldoxime dehydratase, cytochrome P450 119, and catalase. We show conclusively that these proteins incorporate CoPPIX, with the CoPPIX making up at least 95% of the total porphyrin content. In cases in which the native metal ligand is a sulfur or nitrogen, spectroscopic parameters are consistent with retention of native metal ligands. This method is an improvement on previous approaches with respect to both yield and ease-of-implementation. Significantly, this method overcomes a long-standing challenge to incorporate nonnatural cofactors through de novo biosynthesis. By utilizing a ubiquitous laboratory strain, this process will facilitate spectroscopic studies and the development of enzymes for CoPPIX-mediated biocatalysis.

The identity of a metal center often defines enzymatic activity, and swapping the native metal for an alternative one or introducing a new metal center has profound effects. More generally, the chemical utility of natural cofactors has inspired decades of study into synthetic analogs with distinct properties, and researchers have subsequently sought straightforward ways to put these novel cofactors back into proteins (1). Substituted metalloenzymes constitute one of the simplest cases. Changing the identity of the metal ion in metalloproteins has enabled powerful spectroscopic and functional studies of these proteins (210) in addition to new biocatalytic activities (1120). However, most methods for producing such proteins with new-to-nature cofactors are limited by the inability to produce the novel protein–cofactor complex in vivo.Hemoproteins, in particular, have been studied through metal substitution because of their important biological functions and utility as biocatalysts. Heme is a ubiquitous and versatile cofactor in biology, and heme-dependent proteins serve essential gas sensing functions (21), metabolize an array of xenobiotic molecules (22), and perform synthetically useful oxygen activation and radical-based chemistry (23). Metal-substituted hemoproteins have enabled key spectroscopic studies of hemoprotein function and the development of biocatalysts with novel reactivity. For example, electron paramagnetic resonance (EPR) studies on cobalt-substituted sperm whale myoglobin (CoMb) enabled detailed characterization of the paramagnetic CoMbO2 complex (3, 4, 24, 25). In analogous oxygen-binding studies in CoMb and cobalt-substituted hemoglobin (5, 6, 26), resonance Raman was used to identify the O–O stretching mode because cobalt-substituted proteins exhibit enhancement of this vibrational mode compared to the native iron proteins.Metal substitution has a profound effect on catalytic activity of hemoproteins, enabling numerous synthetic applications. Substitution of the native iron for cobalt in several hemoproteins, including a thermostable cytochrome c variant, enabled the reduction of water to H2 under aerobic, aqueous conditions (2729). Reconstitution of apoprotein with selected metalloporphyrins has been used to generate metal-substituted myoglobin and cytochrome P450s variants. These enzymes were effective as biocatalysts for C–H activation and carbene insertion reactions (1114). In a tour de force of directed evolution, which required purification and cofactor reconstitution of each individual variant, Hartwig and coworkers generated a cytochrome P450 variant that utilizes a nonnative Ir(Me)mesoporphyrin cofactor to perform desirable C–H activation chemistry (14). These activities may not be unique to the Ir-substituted protein, as synthetic cobalt porphyrin complexes have been shown to mediate a variety of Co(III)-aminyl and -alkyl radical transformations, including C–H activation (3032). Indeed, a number of cobalt porphyrin carbene complexes display significant carbon-centered radical character (3335), whereas the corresponding Fe-porphyrin complexes are closed shell species (36, 37), indicating that cobalt porphyrins may possess distinct, complementary modes of reactivity (3840).Inspired by these applications, researchers have sought strategies for generating metal-substituted hemoproteins. For many metalloproteins, metal substitution is carried out by removal of the native metal with a chelator and replacement with an alternate metal of similar coordination preference. This method is inapplicable to hemoproteins, as porphyrins do not readily exchange metal ions. Consequently, diverse methods have been employed to make metal-substituted hemoproteins (4146). Early on, copper, cobalt, nickel, and manganese-substituted horseradish peroxidase (HRP) were prepared by a multistep process that subjected protein to strong acid and organic solvents (41, 42). Variations of this method have been used repeatedly (24, 43, 4749). However, this method is applicable only to a narrow range of hemoproteins that tolerate the harsh treatment. With the advent of overexpression methods, significant improvement of metalloporphyrin-substituted protein yield was achieved by direct expression of the apoprotein and reconstitution with the desired metalloporphyrin in lysate prior to purification (50). Although this approach has many virtues, direct expression of apoprotein is ineffective for many hemoproteins, again limiting the utility of this method.As an alternative to the above in vitro approaches, researchers have pursued systems for direct in vivo expression of metal substituted hemoproteins. Two specialty strains of Escherichia coli (E. coli) were engineered to incorporate metalloporphyrin analogs from the growth medium into hemoproteins during protein expression. The engineered RP523 strain cannot biosynthesize heme and bears an uncharacterized heme permeability phenotype. Together, these two features enable this strain to assimilate and incorporate various metalloporphyrins into overexpressed hemoproteins with no background heme incorporation (44, 5153). However, heme auxotrophy makes RP523 cells exceedingly sensitive to O2, and, in many situations, RP523 cultures must be grown anaerobically. An alternative BL21(DE3)-based engineered strain harbors a plasmid bearing the heme transporter ChuA, which facilitates import of exogenous heme analogs (45). Production of metalloporphyrin-substituted protein with this ChuA-containing strain relies on growth in iron-limited minimal media, thereby diminishing heme biosynthesis. This method was used successfully to express metal-substituted versions of the heme domain of cytochrome P450 BM3 (45) and several myoglobin variants (11, 12). Because these cells biosynthesize a small quantity of their own heme, they are far more robust than the RP523 cells. Unfortunately, this advantage comes at the cost of increased heme contamination in the product protein (2 to 5%) (45).A set of intriguing papers reported the production of cobalt-substituted human cystathionine β-synthase (CoCBS) that relies on the de novo biosynthesis of CoPPIX from CoCl2 and δ-aminolevulinic acid (δALA), a biosynthetic precursor to heme (46, 54). This method yielded significant amounts of CoCBS—albeit with modest heme contamination (7.4%)—sufficient for spectroscopic and functional characterization of the CoPPIX-substituted protein (8, 46). As cobalt is known to be toxic to E. coli, the researchers passaged the CBS expression strain through cobalt-containing minimal media for 12 d, enabling the cells to adapt to high concentrations of cobalt prior to protein expression. It is plausible that this serial passaging alters the E. coli cells, enabling the biosynthesis of CoPPIX and in vivo production of metal-substituted protein. The adaptation process is slow (>10 d), and it is unknown how genomic instability under these mutagenic conditions affects the reproducibility of this passaging approach.The possibility of facile CoPPIX production is particularly attractive for future biocatalysis efforts. As described above, synthetic cobalt porphyrins have been shown to perform a range of radical-mediated reactions. The ability to produce a CoPPIX center in vivo may enable engineering these unusual reactivities via directed evolution in addition to spectroscopic applications. We therefore set out to explore the unusual phenotype of CoPPIX production by E. coli and to ascertain whether it was possible to efficiently biosynthesize cobalt-containing hemoproteins in vivo from a single “generalist” cell line. Our goal was to achieve an efficient and facile method of cobalt-substituted hemoprotein production with minimal contamination of the native cofactor. Herein, we report the surprising discovery that native E. coli BL21(DE3) can biosynthesize a new-to-nature CoPPIX cofactor (Fig. 1). We use this insight to produce cobalt-substituted hemoproteins in vivo without requirement for complex expression methods or specialized strains.Open in a separate windowFig. 1.Chemical structures of iron protoporphyrin IX (FePPIX or heme b), cobalt protoporphyrin IX (CoPPIX), and free base protoporphyrin IX (H2PPIX).  相似文献   
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