Performance characteristics of a carbon isotope ratio method for detecting doping with testosterone based on urine diols: controls and athletes with elevated testosterone/epitestosterone ratios

Background: Carbon isotope ratio methods are used in doping control to determine whether urinary steroids are endogenous or pharmaceutical. METHODS: Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) was used to determine the delta(13)C values for 5 beta-androstane-3 alpha,17 beta-diyl diacetate (5 beta A), 5 alpha-androstane-3 alpha,17 beta-diyl diacetate (5 alpha A), and 5 beta-pregnane-3 alpha,20 alpha-diyl diacetate (5 beta P) in a control group of 73 healthy males and 6 athletes with testosterone/epitestosterone ratios (T/E) >6. RESULTS: The within-assay precision SDs for 5 beta A, 5 alpha A, and 5 beta P were +/- 0.27 per thousand, +/- 0.38 per thousand, and +/- 0.28 per thousand, respectively. The between-assay precision SDs ranged from +/- 0.40 per thousand to +/- 0.52 per thousand. The system suitability and batch acceptance scheme is based on SDs. For the control group, the mean delta(13)C (SD) values were -25.69 per thousand (+/- 0.92 per thousand), -26.35 per thousand (+/- 0.68 per thousand), and -24.26 per thousand (+/- 0.70 per thousand), for 5 beta A, 5 alpha A, and 5 beta P, respectively. 5 beta P was greater than 5 beta A and 5 alpha A (P <0.01), and 5 beta A was greater than 5 alpha A (P <0.01). The means - 3 SD were -28.46 per thousand, -28.39 per thousand, and -26.37 per thousand for 5 beta A, 5 alpha A, and 5 beta P, respectively. The maximum difference between 5 beta P and 5 beta A was 3.2 per thousand, and the maximum 5 beta A/5 beta P was 1.13. Three athletes with chronically elevated T/Es had delta(13)C values consistent with testosterone administration and three did not. CONCLUSIONS: This GC-C-IRMS assay of urine diols has low within- and between-assay SDs; therefore, analysis of one urine sample suffices for doping control. The means, SDs, +/-3 SDs, and ranges of delta(13)C values in a control group are established. In comparison, testosterone users have low 5 beta A and 5 alpha A, large differences between 5 beta A or 5 alpha A and 5 beta P, and high 5 beta A/5 beta P and 5 alpha A/5 beta P ratios.     

Orbital fractures in children

PURPOSE: To describe the demographics, etiologic factors, clinical presentations, and outcomes of orbital fractures in children. METHODS: This was a retrospective case series of 96 consecutive patients under 18 years of age with orbital fractures presenting to the Massachusetts Eye and Ear Infirmary, including both hospitalized and nonhospitalized patients. RESULTS: Orbital fractures in children were most frequently the result of sports, assault, or motor vehicle accident. The majority of patients did not require hospitalization and were treated as outpatients. The medial wall and floor of the orbit were the most frequent locations of fracture. Approximately half of the patients in this series required surgery, most often for entrapment. There were no cases of persistent diplopia in patients in whom surgery was performed or was not indicated. Associated ocular injuries were observed in half of the patients. CONCLUSIONS: In this series of hospitalized and nonhospitalized patients, orbital fractures in children had a location pattern similar to that most frequently observed in adult patients (floor and medial wall). Orbital fractures in children frequently require surgery. The high prevalence of ocular injury in children with orbital fractures emphasizes the need for a comprehensive ophthalmic evaluation.     

Analysis of mortality in French diabetic patients from death certificates: a comparative study

This study was implemented in France to determine the causes of death in diabetic patients, whether diabetes was mentioned or not on the death certificate, and to assess the underestimation of the prevalence of diabetes at death. Two stratified random samples of death certificates were selected in the national mortality data base. The first included certificates mentioning diabetes as a cause of death (cases). The second, included certificates with no mention of diabetes (controls). For each certificate, a record form was sent to the certifying physician to ascertain diabetes in the first group and to trace unrecorded diabetes in the second group. In case of diabetes, the characteristics of the patient and his disease were collected (age at onset, treatment, complications ...). We obtained complete data for 325 cases and 959 controls. Among cases, 1% of the subjects were not confirmed as diabetic, while almost 10% of the controls were identified as having diabetes. The corresponding ratio of the corrected prevalence at death to that provided by the French statistics was estimated to 4.0 in men and 3.1 in women. Particular features are that 2% of the total diabetic decedents died from acute metabolic complications (diabetic or hyperosmolar coma, acidoketosis, or acute hypoglycemia), and that 33% of the unreported diabetic decedents under 45 died from trauma or poisoning. These results show that in France, the death rates published in the statistics for diabetes dramatically underestimate the impact of diabetes. A high risk of death is linked to this disease, particularly in people aged under 45, a problem that health deciders should address.     

Assembly of large-area,highly ordered,crack-free inverse opal films

Whereas considerable interest exists in self-assembly of well-ordered, porous “inverse opal” structures for optical, electronic, and (bio)chemical applications, uncontrolled defect formation has limited the scale-up and practicality of such approaches. Here we demonstrate a new method for assembling highly ordered, crack-free inverse opal films over a centimeter scale. Multilayered composite colloidal crystal films have been generated via evaporative deposition of polymeric colloidal spheres suspended within a hydrolyzed silicate sol-gel precursor solution. The coassembly of a sacrificial colloidal template with a matrix material avoids the need for liquid infiltration into the preassembled colloidal crystal and minimizes the associated cracking and inhomogeneities of the resulting inverse opal films. We discuss the underlying mechanisms that may account for the formation of large-area defect-free films, their unique preferential growth along the 〈110〉 direction and unusual fracture behavior. We demonstrate that this coassembly approach allows the fabrication of hierarchical structures not achievable by conventional methods, such as multilayered films and deposition onto patterned or curved surfaces. These robust SiO₂ inverse opals can be transformed into various materials that retain the morphology and order of the original films, as exemplified by the reactive conversion into Si or TiO₂ replicas. We show that colloidal coassembly is available for a range of organometallic sol-gel and polymer matrix precursors, and represents a simple, low-cost, scalable method for generating high-quality, chemically tailorable inverse opal films for a variety of applications.     

Reply to discussion of ‘Empirical vs natural weighting in random effects meta‐analysis’

Three discussion papers raise interesting points, but at the end of the day, we continue to recommend that past meta‐analyses which have influenced public policy or clinical paradigms be reanalyzed by unweighted methods. For all future meta‐analyses that employ either (a) fixed effects where concomitant treatment and/or eligibility are diverse or (b) classical random effects weighted methods, unweighted methods should serve as the primary analysis. Other analyses would be reasonable as secondary approaches. Two commentaries suggest that weights are only random to the extent of estimation errors in the between study and within study variance components. We shall demonstrate that even if these components are known, there is still considerable random variability in the weights. In fact, methods that try to weight the estimates inversely proportional to the variance have a number of undesirable properties, including bias, incorrect standard errors, inconsistency (including coverage of confidence intervals), and counter‐intuitive properties that the expectation of the estimator changes both with the number of studies sampled and with constant multiples of sample size across all studies. These adverse properties do not exist for the unweighted approach. From the numerical example of phenylephrine 10 mg, despite the arguments of Waksman, the proper conclusion is that the collection of studies does not constitute evidence‐based support for efficacy in terms of lowering nasal airway resistance. In the final section, we present two compelling examples where questionable inferences were made, with potential major public implications. Copyright © 2010 John Wiley & Sons, Ltd.     

Multiple Synapse Formation: A Possible Compensatory Mechanism for Increased Cell Size in Rat Supraoptic Nucleus

Magnocellular neuroendocrine cells of the rat supraoptic nucleus undergo numerous morphological changes during chronic dehydration of the animal. These changes include increases in cell size, the percentage of neuronal membrane in direct apposition and formation of new multiple synapses (i.e. terminals which form more than one synapse with adjacent somata and/or dendrites). Previous studies of multiple synapse formation in the supraoptic nucleus did not include adjustments for changes in somatic size, thus the full extent of synapse formation relative to increases in cell size was not known. That multiple synapse formation is a compensatory mechanism for increased somatic size was investigated by comparing animals that were either chronically dehydrated (by drinking 2% saline) or were well hydrated. Using morphometric techniques the percentage of somatic membrane contacted by single and multiple synapses was obtained. Estimates of somatic surface area were used together with stereologically derived estimates of the number of synapses per μm² to calculate the number of single and multiple axo-somatic synapses per neuron. Measures of soma-somatic and soma-dendritic membrane apposition and glial coverage were made to confirm earlier estimates of these parameters. Somatic surface area increased by more than 70% in dehydrated animals. Percentage of somatic membrane contacted by single synapses was lower (by 41%) and that contacted by multiple synapses was higher (by 100%) in dehydrated as compared to control animals. The number of single synapses was not different between the two groups but dehydrated animals had more multiple synapses per soma (23) than controls (6). With dehydration, there was an eight-fold increase in the percentage of somatic membrane contacted by adjacent somatic/dendritic membrane. The surface area per somain such direct apposition was fifteen-fold higher in dehydrates compared to controls. Glial processes covered the same proportion of somatic membrane in the two groups, while the actual area covered by glial processes per soma was higher in dehydrated animals. These results are consistent with the hypothesis that multiple synapse formation at least partially compensates for probable relative decreases in synaptic efficacy as synaptic density decreases when cells increase in size due to dehydration. This altered synaptic input as well as the increased direct apposition between adjacent neurons probably contribute to their enhanced activation during periods of increased hormone demand.     

Activation of excitatory amino acid inputs to supraoptic neurons. II. Increased dye-coupling in maternally behaving virgin rats

Electrical stimulation of the lateral olfactory tract (LOT) has been shown to excite, monosynaptically, supraoptic nucleus (SON) neurons in slices of hypothalamus taken from male, virgin female or lactating rats. Only in the last of these, however, did 10 min of 10 Hz stimulation produce an increase in the incidence of Lucifer yellow dye-coupling, an indicator of electrotonic interactions. This coupling is virtually exclusively dendrodendritic. Since virgin females that have been induced to show full maternal behavior have altered dendritic morphology reminiscent of lactating animals (but different from males and untreated virgins) we investigated the effects of LOT stimulation in slices from maternally behaving virgins. Similar to the data for lactating rats, electrical stimulation of this tract, the terminals of which release excitatory amino acid transmitter, increased the incidence of dye-coupling by 112% (P less than 0.01). Also similar to lactating rats, the coupling was dendrodendritic and the increase was due entirely to increasing the number of neurons coupled to the injected neuron. No increase in coupling was seen in stimulated slices from pup-exposed control rats. We conclude that the maternal behaviors engaged in by both real mothers and induced virgins 'primes' the supraoptic neurons to increase coupling in response to olfactory system stimulation. This priming may occur via olfactory and vomeronasal stimulation during such behaviors as sniffing and anogenital licking of the pups. That coupling increased in tissue from maternally behaving virgins comparably to that from nursing mothers further suggests that SON neurons may play a role in maternal behavior independent of its well-documented role in the milk ejection reflex.     

Temperature rise due to finishing of direct restorative materials

An in vitro study was performed to evaluate the effect of four variables on the temperature rise produced by the finishing of restorations. The four variables were: restorative material, finishing agent, finishing time, and depth of dentin under the restoration. Class V preparations were cut on extracted premolars and restored with amalgam, composite, or glass ionomer cement. Finishing was done with wet pumice and cup, wet pumice and a brush, a grit rubber polishing point, and an aluminum oxide- coated disc. Finishing time was continuous or intermittent for up to 1 minute. Dentin thickness under the restoration was 0.5 mm to 3.0 mm. Amalgam produced the highest temperature rises at the pulp, while composite and glass ionomer were no different than the untreated (virgin) tooth. Aluminum oxide discs produced the largest temperature rise, wet pumice with a brush the least. Temperature rise increased almost linearly with continuous finishing, while intermittent finishing significantly reduced temperature rise in all cases. Thickness of remaining dentin was only significant for the amalgam restoration, and then only at 1.0 and 0.5 mm.     

Collateral input to the paraventricular and supraoptic nuclei in rat. I. Afferents from the subfornical organ and the anteroventral third ventricle region

Injections of two fluorescent retrograde tracers were used to investigate the existence of collateral branching of input to the hypothalamic magnocellular neuroendocrine neurons. Injection of one tracer (either Fluoro-Gold or rhodamine-labeled microspheres) into the supraoptic nucleus and the other tracer into the ipsilateral paraventricular nucleus produced labeled neurons within the subfornical organ and the anteroventral third ventricle area. Some labeled cells were found to contain both fluorescent tracers (double-labeled cells), suggesting that they project to both the paraventricular and supraoptic nuclei via branching axons. Most double-labeled cells were found within the subfornical organ. Fewer of these cells were located within the nucleus medianus preopticus, and still fewer were distributed in the organum vasculosum lamina terminalis, the bed nucleus of the stria terminalis, and the medial and the lateral preoptic areas. These data present the first direct evidence that single cells may provide input to more than one magnocellular neuroendocrine nucleus. Hypothetically, hormonal release would require coordinated firing of many magnocellular cells. Thus, the branched input to these neurons may assist in the organization and the timely activation of this system in response to physiological stimuli.