Neutrophil-derived catecholamines mediate negative stress effects on bone.

Mental traumatization is associated with long-bone growth retardation, osteoporosis and increased fracture risk. We revealed earlier that mental trauma disturbs cartilage-to-bone transition during bone growth and repair in mice. Trauma increased tyrosine hydroxylase-expressing neutrophils in bone marrow and fracture callus. Here we show that tyrosine hydroxylase expression in the fracture hematoma of patients correlates positively with acknowledged stress, depression, and pain scores as well as individual ratings of healing-impairment and pain-perception post-fracture. Moreover, mice lacking tyrosine hydroxylase in myeloid cells are protected from chronic psychosocial stress-induced disturbance of bone growth and healing. Chondrocyte-specific ß2-adrenoceptor-deficient mice are also protected from stress-induced bone growth retardation. In summary, our preclinical data identify locally secreted catecholamines in concert with ß2-adrenoceptor signalling in chondrocytes as mediators of negative stress effects on bone growth and repair. Given our clinical data, these mechanistic insights seem to be of strong translational relevance.

Myeloid cell-derived catecholamines influence bone turnover and regeneration in mice.

Catecholamine signaling is known to influence bone tissue as reuptake of norepinephrine released from sympathetic nerves into bone cells declines with age leading to osteoporosis. Further, ß-adrenoceptor-blockers like propranolol provoke osteoprotective effects in osteoporotic patients. However, besides systemic adrenal and sympathetic catecholamine production, it is also known that myeloid cells can synthesize catecholamines, especially under inflammatory conditions. To investigate the effects of catecholamines produced by CD11b+ myeloid cells on bone turnover and regeneration, a mouse line with specific knockout of tyrosine hydroxylase, the rate-limiting enzyme of catecholamine synthesis, in CD11b+ myeloid cells (THflox/flox/CD11b-Cre+, referred to as THCD11b-Cre) was generated. For bone phenotyping, male mice were sacrificed at eight and twelve weeks of age and harvested bones were subjected to bone length measurement, micro-computed tomography, fluorescence-activated cell sorting of the bone marrow, gene expression analysis, histology and immunohistochemistry. Support for an age-dependent influence of myeloid cell-derived catecholamines on bone homeostasis is provided by the fact that twelve-week-old, but not eight-week-old THCD11b-Cre mice, developed an osteopenic phenotype and showed increased numbers of neutrophils and T lymphocytes in the bone marrow, while CCL2, IL-6, IL-4 and IL-10 mRNA expression was reduced in sorted myeloid bone marrow cells. To investigate the influence of myeloid cell-derived catecholamines on fracture healing, mice received a diaphyseal femur osteotomy. Three days post-fracture, immunohistochemistry revealed an increased number of macrophages, neutrophils and cytotoxic T lymphocytes in the fracture hematoma of THCD11b-Cre mice. Micro-computed tomography on day 21 showed a decreased tissue mineral density, a reduced bone volume and less trabeculae in the fracture callus indicating delayed fracture healing, probably due to the increased presence of inflammatory cells in THCD11b-Cre mice. This indicates a crucial role of myeloid cell-derived catecholamines in immune cell-bone cell crosstalk and during fracture healing.

Implicit approach-avoidance tendencies toward food and body stimuli absent in individuals with anorexia nervosa, bulimia nervosa, and healthy controls.

OBJECTIVE: Body and food-related information are thought to activate cognitive biases and contribute to the maintenance of eating disorders (ED). Approach-avoidance biases may play an important role in the maintenance of dietary restriction and excessive food intake. Therefore, the present study aimed to examine approach-avoidance biases toward food and body stimuli in individuals with anorexia nervosa (AN), bulimia nervosa (BN), and healthy controls (HC). METHODS: The study included 42 individuals with AN, 24 individuals with BN, and 38 HCs. We used two implicit Approach-Avoidance Tasks (AAT) to assess approach-avoidance biases: participants completed a Food-AAT (high-calorie vs. low-calorie food) and a Body-AAT (thin vs. normal weight bodies). Additionally, explicit ratings of food and body stimuli were assessed. RESULTS: There were no significant Group × Stimulus × Direction interactions in the implicit Food-AAT or implicit Body-AAT. In explicit ratings, individuals with AN and BN reported less urge to eat and more regret if they ate high-calorie and low-calorie food; individuals with AN and BN rated normal weight bodies as less normal weight, less attractive and less desirable than HCs. There were no group differences in explicit ratings of the thin body. DISCUSSION: We did not find evidence for biased approach-avoidance tendencies toward food or body stimuli in individuals with AN or BN. Future studies are necessary to understand conflicting findings regarding approach-avoidance biases toward food and body stimuli in individuals with ED.

Investigation of coatings of natural organic matter on silver nanoparticles under environmentally relevant conditions by surface-enhanced Raman scattering.

The widespread use of engineered inorganic nanoparticles (EINP) leads to a growing risk for an unintended release into the environment. Despite the good characterization of EINP in regard to their function scale and the application areas, there is still a gap of knowledge concerning their behaviour in the different environmental compartments. Due to their high surface to volume ratio, surface properties and existence or development of a coating are of high importance for their stability and transport behaviour. However, analytical methods to investigate organic coatings on nanoparticles in aqueous media are scarce. We used Raman microspectroscopy in combination with surface-enhanced Raman scattering (SERS) to investigate humic acid coatings on silver nanoparticles under environmentally relevant conditions and in real world samples. This setup is more challenging than previous mechanistic studies using SERS to characterize the humic acids in tailored settings where only one type of organic matter is present and the concentrations of the nanoparticles can be easily adjusted to the experimental needs. SERS offers the unique opportunity to work with little sample preparation directly with liquid samples, thus significantly reducing artefacts. SERS spectra of different natural organic matter brought into contact with silver nanoparticles indicate humic acid in close proximity to the nanoparticles. This coating was also present after several washing steps by centrifugation and resuspension in deionized water and after an increase in ionic strength.

Understanding the fate and biological effects of Ag- and TiO2-nanoparticles in the environment: The quest for advanced analytics and interdisciplinary concepts.

Engineered inorganic nanoparticles (EINP) from consumers' products and industrial applications, especially silver and titanium dioxide nanoparticles (NP), are emitted into the aquatic and terrestrial environments in increasing amounts. However, the current knowledge on their environmental fate and biological effects is diverse and renders reliable predictions complicated. This review critically evaluates existing knowledge on colloidal aging mechanisms, biological functioning and transport of Ag NP and TiO2 NP in water and soil and it discusses challenges for concepts, experimental approaches and analytical methods in order to obtain a comprehensive understanding of the processes linking NP fate and effects. Ag NP undergo dissolution and oxidation with Ag2S as a thermodynamically determined endpoint. Nonetheless, Ag NP also undergo colloidal transformations in the nanoparticulate state and may act as carriers for other substances. Ag NP and TiO2 NP can have adverse biological effects on organisms. Whereas Ag NP reveal higher colloidal stability and mobility, the efficiency of NOM as a stabilizing agent is greater towards TiO2 NP than towards Ag NP, and multivalent cations can dominate the colloidal behavior over NOM. Many of the past analytical obstacles have been overcome just recently. Single particle ICP-MS based methods in combination with field flow fractionation techniques and hydrodynamic chromatography have the potential to fill the gaps currently hampering a comprehensive understanding of fate and effects also at a low field relevant concentrations. These analytical developments will allow for mechanistically orientated research and transfer to a larger set of EINP. This includes separating processes driven by NP specific properties and bulk chemical properties, categorization of effect-triggering pathways directing the EINP effects towards specific recipients, and identification of dominant environmental parameters triggering fate and effect of EINP in specific ecosystems (e.g. soil, lake, or riverine systems).

Kinetics of Schottky defect formation and annihilation in single crystal TlBr.

The kinetics for Schottky defect (Tl and Br vacancy pair) formation and annihilation in ionically conducting TlBr are characterized through a temperature induced conductivity relaxation technique. Near room temperature, defect generation-annihilation was found to take on the order of hours before equilibrium was reached after a step change in temperature, and that mechanical damage imparted on the sample rapidly increases this rate. The rate limiting step to Schottky defect formation-annihilation is identified as being the migration of lower mobility Tl (versus Br), with an estimate for source-sink density derived from calculated diffusion lengths. This study represents one of the first investigations of Schottky defect generation-annihilation kinetics and demonstrates its utility in quantifying detrimental mechanical damage in radiation detector materials.

Teachers' Perceptions of Word Callers and Related Literacy Concepts.

The purpose of the study was to investigate teachers' perceptions of word callers as they relate to the concepts of reading fluency and reading comprehension. To this end, second grade students (N = 408) completed a series of reading fluency and reading comprehension assessments, and their teachers (N = 31) completed word caller nominations and a questionnaire regarding their concepts surrounding these issues. Our findings suggested that teachers often over nominated children as word callers. Further, questionnaire data indicated a great deal of ambiguity and inconsistency exists regarding teachers' understanding and use of the term word caller. By contrast, teachers seemed to possess a veridical understanding of the related terms reading fluency and reading comprehension.

The relationship between different measures of oral reading fluency and reading comprehension in second-grade students who evidence different oral reading fluency difficulties.

PURPOSE: The purpose of this study was to examine whether different measures of oral reading fluency relate differentially to reading comprehension performance in two samples of second-grade students: (a) students who evidenced difficulties with nonsense-word oral reading fluency, real-word oral reading fluency, and oral reading fluency of connected text (ORFD), and (b) students who evidenced difficulties only with oral reading fluency of connected text (CTD). METHOD: Participants (ORFD, n = 146 and CTD, n = 949) were second-grade students who were recruited for participation in different reading intervention studies. Data analyzed were from measures of nonsense-word oral reading fluency, real-word oral reading fluency, oral reading fluency of connected text, and reading comprehension that were collected at the pre-intervention time point. RESULTS: Correlational and path analyses indicated that real-word oral reading fluency was the strongest predictor of reading comprehension performance in both samples and across average and poor reading comprehension abilities. CONCLUSION: Results of this study indicate that real-word oral reading fluency was the strongest predictor of reading comprehension and suggest that real-word oral reading fluency may be an efficient method for identifying potential reading comprehension difficulties.

Insights into Fluency Instruction: Short- and Long-term Effects of Two Reading Programs.

The purpose of the study was to examine short- and long-term effects of two instructional approaches designed to improve the reading fluency of second grade children: Fluency-Oriented Reading Instruction (or FORI; Stahl & Heubach, 2005) and a wide reading approach (Kuhn et al., 2006). By the end of second grade, children in the wide reading classrooms showed better fluency and self-concept compared to children in control classrooms. Classroom observations indicated children in FORI classrooms were more likely to be off-task than controls. However, by the end of third grade, children in both programs displayed better comprehension. We conclude that extensive and long-term focus on the oral reading of complex texts using practices that scaffold reading in second grade is beneficial for the long-term development of reading comprehension skills.

Myth and Reality of the Word Caller: The Relation Between Teacher Nominations and Prevalence Among Elementary School Children.

The purpose of the study was to investigate (a) the prevalence of word callers in elementary school, (b) the accuracy of teachers' word caller nominations, and (c) teachers' conceptualization of reading fluency and reading comprehension. To this end, 2 cross-sectional studies of second- and third- (N = 868) and of third- and fifth-grade (N = 202) children were conducted. Our findings suggest that word callers occur infrequently in the primary grades but that they are more prevalent in late elementary school. Regardless of grade level, teachers often overnominated children as word callers. Furthermore, a great deal of ambiguity and inconsistency seems to exist regarding teachers' understanding and use of the term. These findings suggest that the term should be used relatively rarely and that reading educators should be cautious about their identification of word callers in early elementary school.

Neurodegeneration and motor dysfunction in a conditional model of Parkinson's disease.

Alpha-synuclein (alpha-syn) has been implicated in the pathogenesis of many neurodegenerative disorders, including Parkinson's disease. These disorders are characterized by various neurological and psychiatric symptoms based on progressive neuropathological alterations. Whether the neurodegenerative process might be halted or even reversed is presently unknown. Therefore, conditional mouse models are powerful tools to analyze the relationship between transgene expression and progression of the disease. To explore whether alpha-syn solely originates and further incites these alterations, we generated conditional mouse models by using the tet-regulatable system. Mice expressing high levels of human wild-type alpha-syn in midbrain and forebrain regions developed nigral and hippocampal neuropathology, including reduced neurogenesis and neurodegeneration in absence of fibrillary inclusions, leading to cognitive impairment and progressive motor decline. Turning off transgene expression in symptomatic mice halted progression but did not reverse the symptoms. Thus, our data suggest that approaches targeting alpha-syn-induced pathological pathways might be of benefit rather in early disease stages. Furthermore, alpha-syn-associated cytotoxicity is independent of filamentous inclusion body formation in our conditional mouse model.

The influence of reading unit size on the development of Stroop interference in early word decoding.

The purpose of the experiments was to determine the automatic use of large or small word reading units in young readers in the absence of word decoding strategies. Picture-word Stroop interference was examined from four types of conflicting labels: (a) words containing both highly predictable grapheme-phoneme correspondence (GPC) units and highly consistent rime units (henceforth, Hi-GPC + Hi-Rime); (b) words with highly predictable GPC units and less consistent rime units (Hi-GPC + Lo-Rime); (c) words with low predictability GPC units and highly consistent rime units (Low GPC + High Rime); (d) nonwords that contained both highly predictable GPC and highly consistent rime units. Naming time for pictures containing these labels was compared against that for pictures with random letter strings or no labels. In Experiment 1, Stroop interference was examined in first, second, and third grade children to determine whether there was developmental change in the presence of rime or GPC interference. In Experiment 2, Stroop interference was examined as a function of relative reading skill in first grade children. In Experiment 3, Stroop interference in adults was compared to the use of rime or GPC pronunciation strategies for nonword reading. In all experiments, Stroop interference in picture naming was longer for pictures with highly predictable GPC unit labels than less predictable GPC unit labels. However, in Experiment 3, even though adults showed interference from predictable GPC units in the Stroop task, they always preferred rime pronunciation for ambiguous non-words in the nonword reading task. It is argued that the current experiments provide evidence for a flexible units model.

Whole genome expression analyses of single- and double-knock-out mice implicate partially overlapping functions of alpha- and gamma-synuclein.

alpha-Synuclein has been implicated in the pathogenesis of Parkinson's disease. The function of alpha-synuclein has not been deciphered yet; however, it might play a role in vesicle function, transport, or as a chaperone. alpha-Synuclein belongs to a family of three proteins, which includes beta- and gamma-synuclein. gamma-Synuclein shares 60% similarity with alpha-synuclein. Similar to alpha-synuclein, a physiological function for gamma-synuclein has not been defined yet, but it has been implicated in tumorgenesis and neurodegeneration. Interestingly, neither alpha- (SNCA(-/-)), gamma- (SNCG(-/-)), nor alpha/gamma- (SNCA_G(-/-)) deficient mice are present with any obvious phenotype. Using microarray analysis, we thus investigated whether deficiency of alpha- and gamma-synuclein leads to similar compensatory mechanisms at the RNA level and whether similar transcriptional signatures are altered in the brain. Sixty-five genes were differentially expressed in all mice. SNCA(-/-) mice and SNCG(-/-) mice shared 84 differentially expressed genes, SNCA(-/-) and SNCA_G(-/-) expressed 79 genes, and SNCG(-/-) and SNCA_G(-/-) expressed 148 genes. For many of the physiological pathways such as dopamine receptor signaling (down-regulated), cellular development, nervous system function, and cell death (up-regulated), we found groups of genes that were similarly altered in SNCA(-/-) and SNCG(-/-) mice. In one of the pathways altered in both models, we found Mapk1 as the core transcript. Other gene groups, however, such as TGF-beta signaling and apoptosis pathways genes were significantly up-regulated in the SNCA(-/-) mice but down-regulated in SNCG(-/-) mice. beta-synuclein expression was not significantly altered in any of the models.

Transport of multidrug resistance substrates by the Streptococcus agalactiae hemolysin transporter.

Streptococcus agalactiae (group B streptococcus [GBS]) causes neonatal sepsis, pneumonia, and meningitis, as well as infections of the bovine udder. The S. agalactiae hemolysin is regarded as an important virulence factor, and hemolysin expression is dependent on the cyl gene cluster. cylA and cylB encode the ATP binding and transmembrane domains of a typical ATP binding cassette (ABC) transporter. The deduced proteins contain the signature sequence of a multidrug resistance (MDR) transporter, and mutation of the genes results in a nonhemolytic and nonpigmented phenotype. To further elucidate the function of the putative transporter, nonpolar deletion mutants of cylA were constructed. These mutants are nonhemolytic and can be complemented by the transporter genes. Wild-type strain and nonhemolytic cylA and cylK deletion mutants were exposed to known substrates of MDR transporters. Mutation of cylA significantly impaired growth in the presence of daunorubicin, doxorubicin, and rhodamine 6G and resulted in a decreased export of doxorubicin from the cells. The mutation of cylK, a gene of unknown function located downstream from cylA, caused a loss of hemolysis but had no effect on the transport of MDR substrates. Furthermore, the hemolytic activity of the wild-type strain was inhibited by reserpine in a dose-dependent manner. We conclude that CylAB closely resembles an ABC-type MDR transporter and propose that the GBS hemolysin molecule represents a natural substrate of the transporter.

Epidemiology of Streptococcus agalactiae colonization in Germany.

Streptococcus agalactiae can cause severe pneumonia, sepsis and meningitis in neonates and remains one of the most prevalent causes of invasive neonatal infections. Maternal transmission of S. agalactiae during delivery can be prevented by prenatal screening and peripartal antibiotic prophylaxis. Implementation of CDC guidelines for group B streptococci (GBS) disease prevention resulted in a significant decline of invasive neonatal S. agalactiae infections in the USA. Similar national guidelines were issued in 2000 for Germany. However, the epidemiology of S. agalactiae colonization in Germany has not been investigated for more than 15 years and the impact these guidelines will have is therefore unknown. To assess colonization rates in Germany, we cultured vaginal and rectal swabs for S. agalactiae from pregnant and non-pregnant adult patients in the region of Aachen and Munich. Swabs were cultivated in selective broth medium for 24h and subsequently plated on blood agar plates according to the CDC recommendations. Colonies negative for catalase and pyrrolidonyl aminopeptidase were further differentiated by the CAMP test and a DNA probe specific for S. agalactiae. Rectal or vaginal colonization of S. agalactiae was found in 34 (16%) of 210 pregnant patients and in 41 (16%) of 250 non-pregnant women. S. agalactiae was found only in rectal swabs in 4% of pregnant and non-pregnant patients. For further characterization of the strains capsular serotypes and major surface protein antigens were determined by Ouchterlony immunodiffusion and PCR. Among the 75 different patient isolates serotype III was the most prevalent with 21 (28%) isolates, followed by 16 (21%) isolates of serotype II, 13 (17%) isolates of serotype Ia, 12 (16%) of serotype V, 11 (15%) of serotype Ib and only 2 (3%) isolates of serotype IV. The vast majority of all strains harbored genes for the major surface protein antigens, the alpha-C-protein or alpha-C-protein like antigens like Alp2-4, epsilon and Rib. These data show that S. agalactiae colonization is common in Germany and strict adherence to the guidelines for the preventions of GBS disease will result in peripartal antibiotic prophylaxis in up to 20% of all deliveries.

All Oral Reading Practice Is Not Equal or How Can I Integrate Fluency Into My Classroom?

This paper discusses fluency's role in reading development and suggests ways of incorporating fluency instruction into the literacy curriculum through a range of oral reading approaches. It concentrates on two distinct groups of learners: students who are making the shift to fluent reading (generally second and third graders) and those who have experienced difficulty making this transition (usually in fourth grade and beyond). As such, it presents approaches that can supplement a given literacy curriculum as well as approaches that can serve as the basis of a shared reading program. This range of instructional methods should assist both groups of learners in making the transition from purposeful decoding and monotonous reading to automatic word recognition and the expressive rendering of text.

Teaching Children to Become Fluent and Automatic Readers.

The purpose of the study was to examine the effects of two instructional approaches designed to improve the reading fluency of 2nd-grade children. The first approach was based on Stahl and Heubach's (2005) fluency-oriented reading instruction (FORI) and involved the scaffolded, repeated reading of grade-level texts over the course of each week. The second was a wide-reading approach that also involved scaffolded instruction. hut that incorporated the reading of 3 different grade-level texts each week and provicled significantly less opportunity for repetition. By the end of the school year. FORI and wide-reading approaches showed similar benefits for standardized measures of word reading efficiency and reading comprehension skills compared to control approachcs. although the benefits of the wide-reading approach emerged earlier and included oral text reading fluency skill. Thus, we conclude that fluency instruction that emphasizes extensive oral reading of grade-level text using scaffolded approaches is effective for promoting reading development in young learners.

Becoming a fluent and automatic reader in the early elementary school years.

The goals of this study were to (a) develop an empirically based model regarding the development of fluent and automatic reading in the early elementary school years and (b) determine whether fluent text-reading skills provided benefits for reading comprehension beyond those accounted for by fluent word decoding. First-, second-, and third-grade children completed a series of reading tasks targeting word and nonword processing, text reading, spelling knowledge, autonomous reading, and reading comprehension. Structural equation modeling was carried out to evaluate how these skills operated together to produce fluent text reading and good comprehension. Evidence supported a simple reading fluency model for the early elementary school years suggesting that fluent word and text reading operate together with autonomous reading to produce good comprehension.

Becoming a Fluent Reader: Reading Skill and Prosodic Features in the Oral Reading of Young Readers.

Prosodic reading, or reading with expression, is considered one of the hallmarks of fluent reading. The major purpose of the study was to learn how reading prosody is related to decoding and reading comprehension skills. Suprasegmental features of oral reading were measured in 2nd- and 3rd-grade children (N = 123) and 24 adults. Reading comprehension and word decoding skills were assessed. Children with faster decoding speed made shorter and less variable intersentential pauses, shorter intrasentential pauses, larger sentence-final fundamental frequency (F(0)) declinations, and better matched the adult prosodic F(0) profile. Two structural equation models found evidence of a relationship between decoding speed and reading prosody as well as decoding speed and comprehension. There was only minimal evidence that prosodic reading was an important mediator of reading comprehension skill.