Simultaneous determination of iron and copper in children's sera by FAAS

Predložena je nova jednostavna metoda plamene atomsko-apsorpcijske spektrometrije (FAAS), za simultano određivanje željeza i bakra u serumu djece. Ona se temelji na predobradbi uzorka u jednom koraku (deproteinizacija s 3 mol L–3 HCl u odnosu 1:1) i kalibraciji u jednom koraku sa standardom pripravljenim u 1.5 mol L–3 HCl. Tijekom optimizacije metode primijenjen je multifaktorski dizajnirani eksperiment. Preporučena metoda osigurava ispravnost, osjetljivost i preciznost usporedljivu onima referentnih metoda. Novi je pristup jednostavan i brz; on štedi i vrijeme i reagense i uzorke, pri čemu je potonje posebno važno u dječjoj dijagnostici.A new and simple flame atomic-absorption spectrometric (FAAS) method is proposed for simultaneous determination of iron and copper in children's sera. It is based on single-step sample pretreatment (deproteinization with 3 mol L–1 HCl, ratio 1:1) and single-step calibration using 1.5 mol L–1 HCl standard. During method’s optimization a short multifactorial design experiment was used. The proposed method assures accuracy, sensitivity and precision comparable to that of the reference methods. The new approach is simple and time-, labour- and serum-saving, the latter being especially important in pediatric diagnostics

Ranking Surgical Residency Programs: Reputation Survey or Outcomes Measures?

Objective The release of general surgery residency program rankings by Doximity and U.S. News & World Report accentuates the need to define and establish measurable standards of program quality. This study evaluated the extent to which program rankings based solely on peer nominations correlated with familiar program outcomes measures. Design Publicly available data were collected for all 254 general surgery residency programs. To generate a rudimentary outcomes-based program ranking, surgery programs were rank-ordered according to an average percentile rank that was calculated using board pass rates and the prevalence of alumni publications. A Kendall τ-b rank correlation computed the linear association between program rankings based on reputation alone and those derived from outcomes measures to validate whether reputation was a reasonable surrogate for globally judging program quality. Results For the 218 programs with complete data eligible for analysis, the mean board pass rate was 72% with a standard deviation of 14%. A total of 60 programs were placed in the 75th percentile or above for the number of publications authored by program alumni. The correlational analysis reported a significant correlation of 0.428, indicating only a moderate association between programs ranked by outcomes measures and those ranked according to reputation. Seventeen programs that were ranked in the top 30 according to reputation were also ranked in the top 30 based on outcomes measures. Conclusions This study suggests that reputation alone does not fully capture a representative snapshot of a program’s quality. Rather, the use of multiple quantifiable indicators and attributes unique to programs ought to be given more consideration when assigning ranks to denote program quality. It is advised that the interpretation and subsequent use of program rankings be met with caution until further studies can rigorously demonstrate best practices for awarding program standings

Parathyroid hormone evaluation in normal horses and horses with renal failure

Immunoreactive parathyroid hormone (iPTH), calcium, and inorganic phosphorus levels were measured in the serum of 13 apparently normal horses and in six horses with renal insufficiency. Serum iPTH levels were measured by radioimmunoassay using an antisera produced by immunization of guinea pigs with bovine parathyroid hormone. The antisera reacts primarily with the carboxy-terminal hormone fragment. Serum iPTH level in the normal horses was 504.5 ± 191.4 pg/ml and varied from 246 to 750 pg/ml. Serum iPTH levels in three horses with chronic renal failure, hypercalcemia and hypophosphatemia were below the limits of detection for the assay (<165 pg/ml). The hypercalcemia and hypophosphatemia were thus considered not to be the result of increased parathyroid hormone. Three horses with renal insufficiency which were not hypercalcemic had serum iPTH levels which were normal or greater than normal

Clinical Assessment and Management Examination—Outpatient (CAMEO): Its Validity and Use in a Surgical Milestones Paradigm

Objectives Clinical Assessment and Management Examination—Outpatient (CAMEO) is a metric for evaluating the clinical performance of surgery residents. The aim of this study was to investigate the measurement characteristics of CAMEO and propose how it might be used as an evaluation tool within the general surgery milestones project. Design A total of 117 CAMEO evaluations were gathered and used for analysis. Internal consistency reliability was estimated, and item characteristics were explored. A Kruskal-Wallis procedure was performed to discern how well the instrument discriminated between training levels. An exploratory factor analysis was also conducted to understand the dimensionality of the evaluation. Setting CAMEO evaluations were collected from 2 departments of surgery geographically located in the Midwestern United States. Combined, the participating academic institutions graduate approximately 18 general surgery residents per year. Participants In this retrospective data analysis, the number of evaluations per resident ranged from 1 to 7, and evaluations were collected from 2006 to 2013. For the purpose of data analysis, residents were classified as interns (postgraduate year 1 [PGY1]), juniors (PGY2-3), or seniors (PGY4-5). Results CAMEO scores were found to have high internal consistency (Cronbach’s α = 0.96), and all items were highly correlated (≥0.86) to composite CAMEO scores. Scores discriminated between senior residents (PGY4-5) and lower level residents (PGY1-3). Per an exploratory factor analysis, CAMEO was revealed to measure a single dimension of “clinical competence.” Conclusions The findings of this research aligned with related literature and verified that CAMEO scores have desirable measurement properties, making CAMEO an attractive resource for evaluating the clinical performance of surgery residents

Distribution of 5-Hydroxytryptamine-Immunoreactive Boutons on Alpha-Motoneurons in the Lumbar Spinal Cord of Adult Cats

Recent studies have shown that at least some of the functional effects of serotonin (5-HT) on motoneuron excitability are direct and are mediated via postsynaptic 5-HT receptors on motoneurons. To determine the spatial distribution of direct inputs from the serotonin system on the proximal and distal dendrites of individual motoneurons, we examined identified motoneurons in vivo with a combination of immunohistochemical localization of 5-HT-immunoreactive boutons and intracellular staining with horseradish peroxidase. Seventeen intracellularly stained motoneurons from 12 adult cats were analyzed with light microscopy. Quantitative analysis of 5-HT boutons apposed to dendrites of five representative motoneurons that were entirely reconstructed in three dimensions (each from the lumbosacral spinal cord of a different animal) revealed a total of 7,848 contacts (1,570 ± 487 contacts/postsynaptic neuron; mean ± SD) over the dendrites of these cells. Analysis of contacts on the soma of two of these cells, and on the somas of an additional 12 intracellularly stained motoneurons, revealed a wide range of somatic contacts (11–211 contacts/cell) on motoneuron cell bodies, with an average of 52 contacts/cell. These results indicate that the vast majority of 5-HT-immunoreactive boutons are apposed to dendritic branches rather than to the somatic surface of motoneurons. The spatial distribution of contacts essentially matched the distribution of surface membrane area of the postsynaptic neuron, resulting in a relatively uniform density of contacts (\u3c1/100 μm2) on proximal and distal dendrites. Consequently, the frequency of contacts was higher on the proximal dendritic compartments where available membrane area is greater. There was no preferential distribution of contacts to particular dendrites. Light/electron microscopic correlations were performed on 21 boutons that contacted dendrites (n = 7) of three motoneurons from different animals. At the electron microscope level, most appositions (18/21; 85.7%) selected by our light microscopic criteria were confirmed as direct contacts when the 5-HT boutons were examined through serial sections. Synaptic junctions, generally small and symmetric, were positively identified in only a subset of these cases (n = 6; 28.6%), in part due to the obscuring effects of the peroxidase histochemical precipitate present in both pre- and postsynaptic profiles. A few 5-HT boutons (3/21; 14.3%) selected as contacts by our light microscopic criteria were in fact separated from the adjacent labeled dendrites; in two of these three cases, the separation was due to intrusion of very thin glial lamellae ( These results indicate that the bulbospinal serotonergic system(s) provide a significant, direct synaptic input to spinal motoneurons that innervate hindlimb muscles. The nature of the modulatory actions exerted by such widespread synaptic inputs will affect all regions of the somatodendritic membrane and will ultimately depend on the nature of the 5-HT receptors present over different parts of the postsynaptic neuron\u27s dendritic tree. J. Comp. Neurol. 393:69–83, 1998. © 1998 Wiley-Liss, Inc

Distribution of 5-Hydroxytryptamine-Immunoreactive Boutons on Alpha-Motoneurons in the Lumbar Spinal Cord of Adult Cats

Recent studies have shown that at least some of the functional effects of serotonin (5-HT) on motoneuron excitability are direct and are mediated via postsynaptic 5-HT receptors on motoneurons. To determine the spatial distribution of direct inputs from the serotonin system on the proximal and distal dendrites of individual motoneurons, we examined identified motoneurons in vivo with a combination of immunohistochemical localization of 5-HT-immunoreactive boutons and intracellular staining with horseradish peroxidase. Seventeen intracellularly stained motoneurons from 12 adult cats were analyzed with light microscopy. Quantitative analysis of 5-HT boutons apposed to dendrites of five representative motoneurons that were entirely reconstructed in three dimensions (each from the lumbosacral spinal cord of a different animal) revealed a total of 7,848 contacts (1,570 ± 487 contacts/postsynaptic neuron; mean ± SD) over the dendrites of these cells. Analysis of contacts on the soma of two of these cells, and on the somas of an additional 12 intracellularly stained motoneurons, revealed a wide range of somatic contacts (11–211 contacts/cell) on motoneuron cell bodies, with an average of 52 contacts/cell. These results indicate that the vast majority of 5-HT-immunoreactive boutons are apposed to dendritic branches rather than to the somatic surface of motoneurons. The spatial distribution of contacts essentially matched the distribution of surface membrane area of the postsynaptic neuron, resulting in a relatively uniform density of contacts (\u3c1/100 μm2) on proximal and distal dendrites. Consequently, the frequency of contacts was higher on the proximal dendritic compartments where available membrane area is greater. There was no preferential distribution of contacts to particular dendrites. Light/electron microscopic correlations were performed on 21 boutons that contacted dendrites (n = 7) of three motoneurons from different animals. At the electron microscope level, most appositions (18/21; 85.7%) selected by our light microscopic criteria were confirmed as direct contacts when the 5-HT boutons were examined through serial sections. Synaptic junctions, generally small and symmetric, were positively identified in only a subset of these cases (n = 6; 28.6%), in part due to the obscuring effects of the peroxidase histochemical precipitate present in both pre- and postsynaptic profiles. A few 5-HT boutons (3/21; 14.3%) selected as contacts by our light microscopic criteria were in fact separated from the adjacent labeled dendrites; in two of these three cases, the separation was due to intrusion of very thin glial lamellae ( These results indicate that the bulbospinal serotonergic system(s) provide a significant, direct synaptic input to spinal motoneurons that innervate hindlimb muscles. The nature of the modulatory actions exerted by such widespread synaptic inputs will affect all regions of the somatodendritic membrane and will ultimately depend on the nature of the 5-HT receptors present over different parts of the postsynaptic neuron\u27s dendritic tree. J. Comp. Neurol. 393:69–83, 1998. © 1998 Wiley-Liss, Inc