The white coat in pediatrics: link between medical history and preference for informally dressed physicians

OBJECTIVE: To find out if children show a preference for a doctor in a white coat or an informally dressed doctor, and what factors influence this preference. Further to determine if children show a preference for a physician of their own or of the other sex. METHOD: A series of 20 pairs of photographs showing varying combinations of a male and a female doctor in a white coat or in informal dress was presented to test subjects: 37 children without a medical history, 28 children with a minor and 16 with an extensive medical history, aged between 6 and 12 years. Out of each pair of photographs, the test subjects were invited to choose the doctor they would prefer. RESULTS: On average, the test subjects opted for a doctor in a white coat more often than for an informally dressed doctor (p < 0.05). There was a significant difference in dress preference between children with a less and with a more extensive medical history (p = 0.001): children with no medical history more often chose a doctor in a white coat. Children with an extensive medical history more frequently showed preference for informal dress. The children opted more frequently for a doctor of their own sex (p < 0.001). CONCLUSION: The preference of children for a doctor in a white coat or for an informally dressed doctor depended on their medical history. The more extensive the medical history, the more the preference shifted to an informally dressed doctor. Also, the children preferred a doctor of their own sex.     

Regulation of exocytosis by cyclin-dependent kinase 5 via phosphorylation of Munc18

Munc18a, a mammalian neuronal homologue of Saccharomyces cerevisiae Sec1p protein, is essential for secretion, likely as a result of its high affinity interaction with the target SNARE protein syntaxin 1a (where SNARE is derived from SNAP receptor (the soluble N-ethylmaleimide-sensitive fusion protein)). However, this interaction inhibits vesicle SNARE interactions with syntaxin that are required for secretory vesicles to achieve competency for membrane fusion. As such, regulation of the interaction between Munc18a and syntaxin 1a may provide an important mechanism controlling secretory responsiveness. Cyclin-dependent kinase 5 (Cdk5), a member of the Cdc2 family of cell division kinases, co-purifies with Munc18a from rat brain, interacts directly with Munc18a in vitro, and utilizes Munc18a as a substrate for phosphorylation. We have now demonstrated that Cdk5 is capable of phosphorylating Munc18a in vitro within a preformed Munc18a.syntaxin 1a heterodimer complex and that this results in the disassembly of the complex. Using site-directed mutagenesis, the Cdk5 phosphorylation site on Munc18a was identified as Thr574. Stimulation of secretion from neuroendocrine cells produced a corresponding rapid translocation of cytosolic Cdk5 to a particulate fraction and an increase of Cdk5 kinase activity. Inhibition of Cdk5 with olomoucine decreased evoked norepinephrine secretion from chromaffin cells, an effect not observed with the inactive analogue iso-olomoucine. The effects of olomoucine were independent of calcium influx as evidenced by secretory inhibition in permeabilized chromaffin cells and in cells under whole-cell voltage clamp. Furthermore, transfection and expression in chromaffin cells of a neural specific Cdk5 activator, p25, led to a strong increase in nicotinic agonist-induced secretory responses. Our data suggest a model whereby Cdk5 acts to regulate Munc18a interaction with syntaxin 1a and thereby modulates the level of vesicle SNARE interaction with syntaxin 1a and secretory responsiveness.     

Variation in lipoprotein(a) concentrations among individuals with the same apolipoprotein (a) isoform is determined by the rate of lipoprotein(a) production

Lipoprotein(a) [Lp(a)] is an atherogenic lipoprotein which is similar in structure to, but metabolically distinct from, LDL. Factors regulating plasma concentrations of Lp(a) are poorly understood. Apo(a), the protein that distinguishes Lp(a) from LDL, is highly polymorphic, and apo(a) size is inversely correlated with plasma Lp(a) level. Even within the same apo(a) isoform class, however, plasma Lp(a) concentrations vary widely. A series of in vivo kinetic studies were performed using purified radiolabeled Lp(a) in individuals with the same apo(a) isoform but different Lp(a) levels. In a group of seven subjects with a single S4-apo(a) isoform and Lp(a) levels ranging from 1 to 13.2 mg/dl, the fractional catabolic rate (FCR) of 131I-labeled S2-Lp(a) (mean 0.328 day-1) was not correlated with the plasma Lp(a) level (r = -0.346, P = 0.45). In two S4-apo(a) subjects with a 10-fold difference in Lp(a) level, the FCR's of 125I-labeled S4-Lp(a) were very similar in both subjects and not substantially different from the FCRs of 131I-S2-Lp(a) in the same subjects. In four subjects with a single S2-apo(a) isoform and Lp(a) levels ranging from 9.4 to 91 mg/dl, Lp(a) concentration was highly correlated with Lp(a) production rate (r = 0.993, P = 0.007), but poorly correlated with Lp(a) FCR (mean 0.304 day-1). Analysis of Lp(a) kinetic parameters in all 11 subjects revealed no significant correlation of Lp(a) level with Lp(a) FCR (r = -0.53, P = 0.09) and a strong correlation with Lp(a) production rate (r = 0.99, P < 0.0001). We conclude that the substantial variation in Lp(a) levels among individuals with the same apo(a) phenotype is caused primarily by differences in Lp(a) production rate.     

Concept-Based Method for Extracting Valid Subsets from an EXPRESS Schema

An EXPRESS schema is a data schema defined in EXPRESS, an international standard language for defining product data schemas. This technical paper proposes and formally defines a set of conditions for generating a minimum valid subset of an EXPRESS schema corresponding to a concept, where a concept is a general idea and a subset is a partial model of a data schema. We introduce a notion of “minimal set” to define the relationships between a subset and other subsets, and also between a subset and concepts. A minimal set is the smallest complete subset of a schema that corresponds to a concept. Using IFC, an international standard data model for the architecture, engineering, and construction industry, the proposed conditions have been implemented in a software application developed for extracting subsets from the IFC schema matching the concepts. A number of examples are demonstrated.     

Lymphangioma of the thigh following acute trauma

Only 2 cases of lymphangioma of traumatic origin have been previously reported, and in both it was a matter of repeated microtraumas. This is a report of a circumscribed lymphangioma in a 22-year-old man after a severe direct trauma of the thigh. Five months after the trauma a painless, slowly growing mass appeared in this area. Histologically, the removed mass appeared to be a combination of cavernous and cystic lymphangioma. The development of this lesion, which must be considered a hamartoma, may possibly be attributable to a traumatic hematoma and to subsequent reactive fibrosis which may have blocked the lymph drainage possibly from a sequestrated portion of the primitive lymphatic anlage.     

Apolipoprotein(a) binds to low-density lipoprotein at two distant sites in lipoprotein(a)

Lipoprotein(a) [Lp(a)] consists of low-density lipoprotein (LDL) and apolipoprotein(a) [apo(a)] linked with a disulfide bond. Scanning force microscopy (SFM) of Lp(a) showed, for the first time, a belt-like structure of apo(a) with both ends attached to a spherical LDL. The two ends of apo(a) were bound to the LDL sphere at two distant sites. Occasionally, the ends were attached to two touching spheres. Under the same imaging conditions, LDL appeared as individual spheres. Electron microscopy (EM) studies of Lp(a) by several groups over the past decade failed to reveal this belt-like structure of apo(a). Images of isolated apo(a) in air or in phosphate buffer showed apo(a) as individual belts, and these belts tended to crowd together. Lp(a) formed leaf-like aggregates; apo(a) aggregates were fishnet-like, whereas LDL aggregates were less characteristic. Quantitative analysis of Lp(a) showed the diameter of the LDL to be 24.8 +/- 8.7 nm (n = 46), which is close to the reported value of 24.2 +/- 4.2 nm found with EM. The length of the belts attached to the spheres was measured to be 173.5 +/- 6.6 nm (n = 15). I also found, by using a functionalized tip, that the interaction force between apo(a) and its ligand, lysine, was related to the ionic strength of the bulk solution. This force can be reduced by the presence of epsilon-aminocaproic acid.     

C3a is a chemotaxin for human eosinophils but not for neutrophils. I. C3a stimulation of neutrophils is secondary to eosinophil activation

Inflammatory action of the potent chemotaxin C5a has been well characterized on a variety of human cell types, including neutrophils, monocytes, basophils, and eosinophils. The cellular effects of C3a are less well defined. Contradictory reports have been published for C3a activation of neutrophils. Recent reports that C3a activates both basophils and eosinophils prompted us to reinvestigate the effects of C3a stimulation on eosinophils. We hypothesized that C3a activation of eosinophils, cells that are present in most neutrophil preparations, might lead to neutrophil activation. Using neutrophils of 98% purity, we observed no evidence of cellular activation after stimulation with either C3a, recombinant human C3a (rhC3a), or the synthetic C3a analogue C3a 57-77, Y57. Eosinophils purified to > 98% purity displayed concentration-dependent polarization, chemotaxis, and enzyme release by stimulation with C3a, rhC3a, and the synthetic C3a analogue. An inactive form of C3a, C3adesArg, failed to stimulate either eosinophils or neutrophils. Using neutrophil preparations containing 5-9% eosinophils, up to 20% of neutrophils became polarized after exposure to C3a. Likewise, we demonstrated that supernatant from C3a-stimulated eosinophils promotes neutrophil chemotaxis. Eosinophil polarization experiments were repeated in the presence of antibody to the C5a receptor (C5aR) to show that C3a and C5a interact with different receptors. C3a activates eosinophils in the presence of anti-C5aR antibody at concentrations that fully block C5a activation. We conclude that eosinophils are directly activated by either C3a or C5a, whereas C3a failed to activate neutrophils. C3a acts on eosinophils via a receptor that is distinct from C5aR. Since neutrophils are indirectly stimulated by C3a, eosinophils contaminating neutrophil preparations may explain earlier reports that C3a activates human neutrophils.     

Pseudoexstrophy associated with congenital pouch colon

Pseudoexstrophy or covered exstrophy is a rare exstrophy variant. The authors report a case of covered exstrophy that presented as a newborn with widely separated pubic bones and rectus muscles, a low-set umbilicus, and a subcutaneous bladder. The anal opening was absent, and there was a complex malformation of the external genitalia consisting of a small, laterally displaced penis and a right-sided ectopic hemiscrotum. Micturition and urinary continence were normal. The child also had a high anorectal malformation with a coexistent type IV congenital pouch colon (CPC) malformation. Both kidneys were normal. Preliminary surgery consisted of a divided sigmoid colostomy proximal to the colonic pouch. The literature is reviewed and the embryogenesis of pseudoexstrophy and its associated malformations are discussed.     

Transition to Self-Similarity of Diffusion of Tracer in Turbulent Patch

A mixing of a passive tracer inside a turbulent patch generated by a localized short-time perturbation is studied numerically and analytically. Two kinds of an initial distribution of a tracer are considered: two-layer and continuous with constant gradient. For the turbulent patch shaped as a layer, it is shown that, regardless of details of initial distributions of a turbulent energy and dissipation, a tracer concentration evolves to self-similar regimes as time elapses. Analytical self-similar solutions to turbulent diffusion equations are found for three symmetric shapes of a turbulent patch: layer, cylinder, and sphere. Distributions of the concentration inside a patch are found to be substantially nonuniform, with a typical ratio of a concentration gradient in the middle of a patch to its initial value of about 0.5.     

Amyloid beta-peptide spin trapping. II: Evidence for decomposition of the PBN spin adduct

We investigated the effect of lipoprotein(a) (Lp(a)) on proliferation of human arterial smooth muscle cells (SMCs) and its mechanisms of action. Low density lipoprotein (LDL), Lp(a) and apolipoprotein(a) (apo(a)) significantly stimulated the proliferation of SMCs. Lp(a) and apo(a) reduced the amount of active transforming growth factor-beta (TGF-beta) with the mink lung epithelial cell bioassay, however LDL had no effect. Lp(a), but not apo(a), significantly stimulated the proliferation of SMCs even in the presence of a neutralizing antibody for TGF-beta. Our results suggest that Lp(a) stimulates the proliferation of SMCs via apo(a)-induced inhibition of TGF-beta activation and stimulation of SMCs by the LDL-particle of Lp(a).     

Outcome after hemiarthroplasty for femoral neck fractures in the elderly

A prospective outcome study was performed on 270 patients, 65 years of age and older, who sustained a femoral neck fracture and underwent hemiarthroplasty. The treatment compared was the use of a noncemented unipolar versus either a cemented or a press fit bipolar prosthesis. The outcome variables assessed included the occurrence of a postoperative complication, length and cost of hospitalization, and function in various quality of life measurements. Patients who underwent bipolar hemiarthroplasty with either a cemented or a press fit prosthesis had better pain relief and function than patients who had a noncemented unipolar prosthesis at a minimum of 24 months after surgery. However, the mean hospitalization cost for patients who had a bipolar prosthesis was $12,290 compared with $8876 for a unipolar prosthesis.     

Production of Integrated Automotive Part in High Pressure Diecasting Process Using Salt Core

A new concept of salt core, a melting temperature of which is lower than the solidus temperature of cast alloy,was introduced to produce an integrated casting part having a complicated inner shape or requiring under-cut in high pressure die casting or squeeze casting process. A salt core, named a fusible core in this paper because the salt core can be easily extracted just as holding at a temperature under a solidus temperature of a casting alloy, was developed and applied to produce a fuel control part for automotive GDI engine in high pressure diecasting machine. A different salt material of a lower melting temperature than that of A1 alloy was mixed with a different ceramic particulate to improve a thermo-physical property of fusible core. The thermo-physical property of the fusible core was measured and a weight faction of the ceramic particulate was optimized. The selected core materials were poured in metallic mold by gravity to produce a fusible core for a fuel control part for automotive GDI engine. The fuel control part, which the fusible core was included inside, was successful to fabricate in a conventional diecasting machine with no melting of fusible core during casting.     

Oxidation of apolipoprotein(a) inhibits kringle-associated lysine binding: the loss of intrinsic protein fluorescence suggests a role for tryptophan residues in the lysine binding site

Lipoprotein(a) [Lp(a)] is a low-density lipoprotein complex consisting of apolipoprotein(a) [apo(a)] disulfide-linked to apolipoprotein B-100. Lp(a) has been implicated in atherogenesis and thrombosis through the lysine binding site (LBS) affinity of its kringle domains. We have examined the oxidative effect of 2,2'-azobis-(amidinopropane) HCl (AAPH), a mild hydrophilic free radical initiator, upon the ability of Lp(a) and recombinant apo(a), r-apo(a), to bind through their LBS domains. AAPH treatment caused a time-dependent decrease in the number of functional Lp(a) or r-apo(a) molecules capable of binding to fibrin or lysine-Sepharose and in the intrinsic protein fluorescence of both Lp(a) and r-apo(a). The presence of a lysine analogue during the reaction prevented the loss of lysine binding and provided a partial protection from the loss of tryptophan fluorescence. The partial protection of fluorescence by lysine analogues was observed in other kringle-containing proteins, but not in proteins lacking kringles. No significant aggregation, fragmentation, or change in conformation of Lp(a) or r-apo(a) was observed as assessed by native or SDS-PAGE, light scattering, retention of antigenicity, and protein fluorescence emission spectra. Our results suggest that AAPH destroys amino acids in the kringles of apo(a) that are essential for lysine binding, including one or more tryptophan residues. The present study, therefore, raises the possibility that the biological roles of Lp(a) may be mediated by its state of oxidation, especially in light of our previous study showing that the reductive properties of sulfhydryl-containing compounds increase the LBS affinity of Lp(a) for fibrin.     

Polyethylene wear after total hip arthroplasty: the effect of a modular femoral head with an extended flange-reinforced neck

The use of modular components in total hip arthroplasty has been thought to contribute to accelerated polyethylene wear. Specifically, a modular femoral head with a flange extension and a longer neck may cause increased wear. The purpose of the current study was to evaluate the effect of a flange extension on polyethylene wear. Ninety-one patients who had had a total of 100 primary total hip arthroplasties were evaluated after an intermediate duration of follow-up. All of the acetabular components consisted of a hemispherical titanium-alloy fiber-mesh porous-coated shell with a nonelevated modular polyethylene liner; they were inserted without cement and with use of supplemental screws through the dome after so-called line-to-line reaming. All of the femoral components consisted of a modular head with a diameter of twenty-eight millimeters and either a long neck (with a flange extension) or a short or medium neck (without a flange extension). The study group comprised sixty-two patients (sixty-six hips) who had had radiographic evaluation that was adequate to allow the valid measurement of polyethylene wear. Thirty-two hips were in men, and thirty-four were in women. The mean age of the patients was fifty-six years, the mean weight was seventy-three kilograms, and the mean duration of follow-up was 6.1 years (range, four to eight years). The rate of polyethylene wear in the eleven hips in which the femoral component had a flange extension was significantly greater than that in the fifty-five in which the femoral component did not have a flange extension (mean, 0.17 compared with 0.11 millimeter per year; p = 0.009). Multivariate analysis showed that the presence of a flange extension was associated with increased polyethylene wear to a greater degree (F = 2.86) than were all other variables that were measured, including a younger age (F = 1.72), a more vertical angle of the acetabular component (F = 0.49), a heavier weight (F = 0.14), male gender (F = 0.11), and a smaller initial thickness of the polyethylene (F = 0.02). These data support an association between the presence of a modular femoral head with a flange extension and an accelerated rate of polyethylene wear. The presumed mechanism is an increase in peripheral, or so-called rim, impingement of the flange-reinforced neck on the acetabulum due to a decrease in the ratio between the diameters of the femoral head and neck.     

Development of a blood cardioplegia delivery system for children

We have developed a blood cardioplegia delivery system for children. Essential points of a delivery system in pediatric cardiac surgery are (1) a small amount of priming volume of a delivery system, and (2) slow, steady infusion of a cardioplegic solution. We changed a heat exchanger to a smaller one for reduction of priming volume, and changed a roller pump tube to a smaller one for slow, steady infusion. Thus, priming volume of a delivery system has reduced from 180 to 100 ml, and we can infuse a cardioplegic solution at a steady rate less than 10 ml/min. Our clinical experience with this system suggests that this blood cardioplegia delivery system is useful for pediatric cardiac surgery.     

The effect of amount of reinforcement on the formation of the reinforcing value of a verbal stimulus.

50 student nurses served in a 3-phase experiment involving (a) presentation of 1[, 2[, a nickel, or a dime, contingent on correct answers on a paired-associate task; (b) 30 pairings of these amounts with a nonsense syllable; or (c) the presentation of the nonsense syllable contingent on correct answers on a 2nd paired-associate task. Results indicate that amount of reinforcement can be a significant variable in establishing the relative reinforcement value of a verbal stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of TCDD on Ah receptor, ARNT, EGF, and TGF-alpha expression in embryonic mouse urinary tract

Lipoprotein(a) [Lp(a)] biogenesis was examined in primary cultures of hepatocytes isolated from mice transgenic for both human apolipoprotein(a) [apo(a)] and human apoB. Steady-state and pulse-chase labeling experiments demonstrated that newly synthesized human apo(a) had a prolonged residence time (approximately 60 min) in the endoplasmic reticulum (ER) before maturation and secretion. Apo(a) was inefficiently secreted by the hepatocytes and a large portion of the protein was retained and degraded intracellularly. Apo(a) exhibited a prolonged and complex folding pathway in the ER, which included incorporation of apo(a) into high molecular weight, disulfide-linked aggregates. These folding characteristics could account for long ER residence time and inefficient secretion of apo(a). Mature apo(a) bound via its kringle domains to the hepatocyte cell surface before appearing in the culture medium. Apo(a) could be released from the cell surface by apoB-containing lipoproteins. These studies are consistent with a model in which the efficiency of post-translational processing of apo(a) strongly influences human plasma Lp(a) levels, and suggest that cell surface assembly may be one pathway of human Lp(a) production in vivo. Transgenic mouse hepatocytes thus provide a valuable model system with which to study factors regulating human Lp(a) biogenesis.     

Gas chromatograph/isotope dilution mass spectrometric analysis of airborne benzo

A critical evaluation has been made of the gas chromatography/isotope dilution mass spectrometry (GC/IDMS) analysis of airborne benzo[a]pyrene (B[a]p) using 2H-(deuterium, D) and 13C-labeled benzo[a]pyrene and a low resolution mass spectrometer. Laboratory quality control and field samples were used to determine the suitability of these two isotopically labeled B[a]p as surrogates for GC/IDMS B[a]p analysis. With method spike QC samples, recovery of the B[a]p was compared with the recoveries of D- and 13C-labeled B[a]p to validate the assumption that these two isotopically labeled B[a]p analogs could be used as method surrogates for IDMS B[a]p analyses. Two collocated Anderson Hi-Vol samplers were used to carry out a field study in which total B[a]p loadings from one sampler were correlated to the second sampler, before and after correcting the total B[a]p loadings against the recovery of the D- and 13C-labeled B[a]p. It is shown that a low-resolution mass spectrometer can be used in GC/IDMS B[a]p analysis to achieve results of high precision and accuracy. Depending on data quality objectives, D-labeled B[a]p could be used for IDMS B[a]p analysis, but is not recommended.