Use of external fixation for perilunate dislocations and fracture dislocations

The purpose of this study was to review clinical and radiographic outcomes of perilunate dislocations and fracture dislocations treated with external fixation and K-wire fixation. Twenty patients (18 males and two females) with a mean age of 38 years (range 18–59) who had an acute dorsal perilunate dislocation or fracture dislocation were treated with the use of wrist external fixator and K-wires. The injuries included 12 perilunate dislocations, seven trans-scaphoid perilunate fracture dislocations, and one trans-styloid perilunate fracture dislocation. The median time from trauma to operation was 8 h (2–12 h). Indirect reduction via ligamentotaxis was achieved in all perilunate dislocation, and provisional K-wire fixation was added. In five of seven trans-scaphoid perilunate fracture dislocations, indirect reduction was achieved; whereas in the other two as well as in the case of trans-styloid perilunate fracture dislocation, open reduction was required. External fixator was supplemented with K-wires for stabilization of the fractures and the intercarpal intervals. The interosseous and capsular ligaments were not repaired, even after open reduction of fracture dislocations. The mean follow-up was 39 months (range 18–68 months). Range of motion and grip strength were measured. Cooney’s scoring system was used for the assessment of clinical function. Radiographic evaluation included time to scaphoid union, measurement of radiographic parameters (scapholunate gap, scapholunate angle, lunotriquetral gap, and carpal height ratio) and any development of arthritis. The flexion-extension motion arc and grip strength of the injured wrist averaged 80 and 88%, respectively, of the corresponding values for the contralateral wrists. According to Cooney’s clinical scoring system, overall functional outcomes were rated as excellent in four patients, good in eight, fair in six, and poor in two. Eighteen patients returned to their former occupations. Two patients with a trans-scaphoid perilunate injury developed nonunion of the scaphoid; one of them required scaphoid excision and midcarpal fusion. Two patients had radiographic evidence of arthritis. The use of external fixation and provisional K-wire fixation for the treatment of acute perilunate dislocations is associated with satisfactory midterm functional and radiographic outcomes. This minimally invasive treatment option is simple, reliable, and minimally invasive method that provides proper restoration and stable fixation of carpal alignment.     

Prenatal Polybrominated Diphenyl Ether Exposures and Neurodevelopment in U.S. Children through 5 Years of Age: The HOME Study

Background: Polybrominated diphenyl ethers (PBDEs) are persistent chemicals that have been widely used as flame retardants in furniture, carpet padding, car seats, and other consumer products during the past three decades.Objective: We examined whether in utero exposure to PBDEs is associated with child cognitive function and behavior in a U.S. study sample.Methods: In a prospective birth cohort, we measured maternal serum concentrations of BDE-47 and other PBDE congeners in 309 women at 16 weeks of gestation during 2003–2006 and followed their children in Cincinnati, Ohio. We measured cognitive and motor abilities using the Bayley Scales of Infant Development-II at ages 1, 2, and 3 years; intelligence using the Wechsler Preschool and Primary Scale of Intelligence-III at age 5 years; and children’s behaviors using the Behavioral Assessment System for Children-2 annually at ages 2–5 years. We used linear mixed models or generalized estimating equations with adjustment for potential confounders to estimate associations between these outcomes and log₁₀-transformed PBDE concentrations.Results: The geometric mean of BDE-47 in maternal serum (20.1 ng/g lipid) was comparable with U.S. adult national reference values. Prenatal BDE-47 was not significantly associated with Bayley Mental or Psychomotor Development Indices at 1–3 years, but a 10-fold increase in prenatal BDE-47 was associated with a 4.5-point decrease (95% CI: –8.8, –0.1) in Full-Scale IQ and a 3.3-point increase (95% CI: 0.3, 6.3) in the hyperactivity score at age 5 years.Conclusions: Prenatal exposure to PBDEs was associated with lower IQ and higher hyperactivity scores in children.Citation: Chen A, Yolton K, Rauch SA, Webster GM, Hornung R, Sjödin A, Dietrich KN, Lanphear BP. 2014. Prenatal polybrominated diphenyl ether exposures and neurodevelopment in U.S. children through 5 years of age: the HOME study. Environ Health Perspect 122:856–862; http://dx.doi.org/10.1289/ehp.1307562     

Vaccination coverage and susceptibility against vaccine-preventable diseases of healthcare students in Athens,Greece

Background

Vaccination of healthcare students is important to protect them from acquiring and transmitting vaccine-preventable diseases (VPDs) to high-risk patients and other healthcare workers (HCWs). The aim of the current study was to estimate the vaccination coverage, the susceptibility against VPDs, the knowledge and attitudes toward vaccinations of healthcare students studying at the Athens Technological Educational Institute.

Methods

The study was conducted during the academic year 2012–2013 using a standardized questionnaire.

Results

The mean knowledge score (correct answers) of healthcare students about the vaccines that are recommended by the Greek Ministry of Health for HCWs was 41%. Completed vaccination rates range from 19.6% for varicella to 80.2% for tetanus-diphtheria. A history of measles, mumps, rubella, varicella, hepatitis A, hepatitis B, or pertussis was reported by 8.2%, 4%, 5.4%, 70.4%, 1.5%, 0%, and 3% of students, respectively. Susceptibility rates were 20.5% against measles, 26.4% against mumps, 13.9% against rubella, 15.7% against varicella, 47.8% against hepatitis A, 17.3% against hepatitis B, and 19.8% against tetanus–diphtheria. Mandatory vaccination of HCWs was supported by 145 (96.7%) students.

Conclusions

There are significant immunity gaps against all VPDs among healthcare students in Athens. A system to easily identify non-immune students should be established in association with efficient reminder systems. Education of healthcare students about VPDs and vaccines will improve their attitudes toward vaccinations and their vaccination coverage. Mandatory vaccinations should be considered for HCWs in order to promote safety within healthcare facilities.     

Hyperactive glial cells contribute to axonal pathologies in the spinal cord of Npc1 mutant mice

Niemann‐Pick disease type C1 (NPC1) is a neurodegenerative disease with various progressive pathological features, for example, neuronal loss, dysmyelination, abnormal axon swelling, and gliosis, in the brain. Pathological activation of p38‐mitogen‐activated protein kinase (MAPK) results in hyperphosphorylation of tau protein, which contributes to the development of neurodegenerative diseases. In this study, axonal varicosities or spheroids and presynaptic aggregates in the spinal cord of the Npc1 mutant mice were found from postnatal day (P) 35 onwards, as indicated by the increased hyperphosphorylated neurofilament and synaptophysin immunoreactivity as well as the findings from electron microscopy. However, activities of astrocytes and microglia in the Npc1 mutant spinal cord were progressively increased earlier from P10 onwards, accompanied by increased expression of interleukin‐1β and apolipoprotein E, as well as up‐regulated p38‐MAPK activity and enhanced phosphorylated tau protein, but not cyclin‐dependent kinase 5/p35 complex and glycogen synthase kinase‐3β. Taken together, our data suggest that the axonal pathologies in the Npc1 mutant spinal cord are strongly correlated with the increase of activated glial cells, which produce IL‐1β and ApoE, resulting in the activation of p38‐MAPK signaling pathway and enhanced phosphorylated tau protein. GLIA 2014;62:1024–1040     

Task difficulty in mental arithmetic affects microsaccadic rates and magnitudes

Microsaccades are involuntary, small‐magnitude saccadic eye movements that occur during attempted visual fixation. Recent research has found that attention can modulate microsaccade dynamics, but few studies have addressed the effects of task difficulty on microsaccade parameters, and those have obtained contradictory results. Further, no study to date has investigated the influence of task difficulty on microsaccade production during the performance of non‐visual tasks. Thus, the effects of task difficulty on microsaccades, isolated from sensory modality, remain unclear. Here we investigated the effects of task difficulty on microsaccades during the performance of a non‐visual, mental arithmetic task with two levels of complexity. We found that microsaccade rates decreased and microsaccade magnitudes increased with increased task difficulty. We propose that changes in microsaccade rates and magnitudes with task difficulty are mediated by the effects of varying attentional inputs on the rostral superior colliculus activity map.     

Bindung und Beziehung – eine Analyse aktueller psychoanalytischer Forschungsansätze

The issue of attachment has become increasingly important in research on fields such as developmental psychology, psychoanalysis but also infant research. This paper aims at discussing concepts from attachment theory, established by Bowlby, as well as object relations theory, concentrating on Klein’s and Bion’s contributions. These two theoretical models for understanding the specific individual emotional bond between an individual and its loved objects are elaborated and compared. Subsequently, the protective aspects of secure attachment are discussed and the harmful and psychically endangering qualities of insecure attachment are illustrated, showing that insecure attachment can be connected to psychopathology. Finally, further possibilities for research are pointed out and the potential of merging research methods from objects relations theory with attachment theory are discussed.     

Phenotype of mice with inducible ablation of GluA1 AMPA receptors during late adolescence: Relevance for mental disorders

Adolescence is characterized by important molecular and anatomical changes with relevance for the maturation of brain circuitry and cognitive function. This time period is of critical importance in the emergence of several neuropsychiatric disorders accompanied by cognitive impairment, such as affective disorders and schizophrenia. The molecular mechanisms underlying these changes at neuronal level during this specific developmental stage remains however poorly understood. GluA1‐containing AMPA receptors, which are located predominantly on hippocampal neurons, are the primary molecular determinants of synaptic plasticity. We investigated here the consequences of the inducible deletion of GluA1 AMPA receptors in glutamatergic neurons during late adolescence. We generated mutant mice with a tamoxifen‐inducible deletion of GluA1 under the control of the CamKII promoter for temporally and spatially restricted gene manipulation. GluA1 ablation during late adolescence induced cognitive impairments, but also marked hyperlocomotion and sensorimotor gating deficits. Unlike the global genetic deletion of GluA1, inducible GluA1 ablation during late adolescence resulted in normal sociability. Deletion of GluA1 induced redistribution of GluA2 subunits, suggesting AMPA receptor trafficking deficits. Mutant animals showed increased hippocampal NMDA receptor expression and no change in striatal dopamine concentration. Our data provide new insight into the role of deficient AMPA receptors specifically during late adolescence in inducing several cognitive and behavioral alterations with possible relevance for neuropsychiatric disorders. © 2013 Wiley Periodicals, Inc.     

Beta‐band activity in auditory pathways reflects speech localization and recognition in bilateral cochlear implant users

In normal‐hearing listeners, localization of auditory speech involves stimulus processing in the postero‐dorsal pathway of the auditory system. In quiet environments, bilateral cochlear implant (CI) users show high speech recognition performance, but localization of auditory speech is poor, especially when discriminating stimuli from the same hemifield. Whether this difficulty relates to the inability of the auditory system to translate binaural electrical cues into neural signals, or to a functional reorganization of auditory cortical pathways following long periods of binaural deprivation is unknown. In this electroencephalography study, we examined the processing of auditory syllables in postlingually deaf adults with bilateral CIs and in normal‐hearing adults. Participants were instructed to either recognize (“recognition” task) or localize (“localization” task) the syllables. The analysis focused on event‐related potentials and oscillatory brain responses. N1 amplitudes in CI users were larger in the localization compared with recognition task, suggesting an enhanced stimulus processing effort in the localization task. Linear beamforming of oscillatory activity in CI users revealed stronger suppression of beta‐band activity after 200 ms in the postero‐dorsal auditory pathway for the localization compared with the recognition task. In normal‐hearing adults, effects for longer latency event‐related potentials were found, but no effects were observed for N1 amplitudes or beta‐band responses. Our study suggests that difficulties in speech localization in bilateral CI users are not reflected in a functional reorganization of cortical auditory pathways. New signal processing strategies of cochlear devices preserving unambiguous binaural cues may improve auditory localization performance in bilateral CI users. Hum Brain Mapp 35:3107–3121, 2014. © 2013 Wiley Periodicals, Inc .