Effects of topographical surface modifications of electron beam melted Ti-6Al-4V titanium on human fetal osteoblasts

The aim of the study was to assess the suitability of different Ti-6Al-4V surfaces produced by the electron beam melting (EBM) process as matrices for attachment, proliferation, and differentiation of human fetal osteoblasts (hFOB 1.19). Human osteoblasts were cultured in vitro on smooth and rough-textured Ti-6Al-4V alloy disks. By means of cell number and vitality and SEM micrographs cell attachment and proliferation were observed. The differentiation rate was examined by using quantitative real-time PCR analysis for the gene expression of alkaline phosphatase (ALP), type I collagen (Coll-I), bone sialoprotein (BSP) and osteocalcin (OC). After 3 days of incubation there was a significant higher vitality (p < 0.02) and proliferation (p < 0.02) of hFOB cells on smooth surfaces (R(a) = 0.077 microm) and compact surfaces with adherent partly molten titanium particles on the surface (R(a) /= 56.9 microm) reduced proliferation of hFOB cells. Surface characteristics of titanium can easily be changed by EBM in order to further improve proliferation.     

Extracting biomarkers of autism from MEG resting-state functional connectivity networks

The present study is a preliminary attempt to use graph theory for deriving distinct features of resting-state functional networks in young adults with autism spectrum disorder (ASD). Networks modeled neuromagnetic signal interactions between sensors using three alternative interdependence measures: (a) a non-linear measure of generalized synchronization (robust interdependence measure [RIM]), (b) mutual information (MI), and (c) partial directed coherence (PDC). To summarize the information contained in each network model we employed well-established global graph measures (average strength, assortativity, clustering, and efficiency) as well as graph measures (average strength of edges) tailored to specific hypotheses concerning the spatial distribution of abnormalities in connectivity among individuals with ASD. Graph measures then served as features in leave-one-out classification analyses contrasting control and ASD participants. We found that combinations of regionally constrained graph measures, derived from RIM, performed best, discriminating between the two groups with 93.75% accuracy. Network visualization revealed that ASD participants displayed significantly reduced interdependence strength, both within bilateral frontal and temporal sensors, as well as between temporal sensors and the remaining recording sites, in agreement with previous studies of functional connectivity in this disorder.     

A Holographic Augmented Reality Interface for Visualizing of MRI Data and Planning of Neurosurgical Procedures

Journal of Digital Imaging - The recent introduction of wireless head-mounted displays (HMD) promises to enhance 3D image visualization by immersing the user into 3D morphology. This work...     

Ampicillin/Sulbactam versus Cefuroxime as antimicrobial prophylaxis for cesarean delivery: a randomized study

Background  

The efficacy and safety of a single dose of ampicillin/sulbactam compared to a single dose of cefuroxime at cord clamp for prevention of post-cesarean infectious morbidity has not been assessed.     

Fatigue resistance during high-intensity intermittent exercise from childhood to adulthood in males and females

This study examined the maturation pattern of fatigue resistance (FR) from childhood to adulthood in females and males during high-intensity intermittent exercise and compared FR between females and males in childhood and adolescence. Thirty males (boys 11.3 ± 0.5 years, teen-males 14.7 ± 0.3 years, men 24.0 ± 2.1 years) and 30 females (girls 10.9 ± 0.6 years, teen-females 14.4 ± 0.7 years, women 25.2 ± 1.4) participated in this study. They performed high-intensity intermittent exercise (4 × 18 maximal knee flexions and extensions with 1-min rest) on an isokinetic dynamometer at 120°s⁻¹. Peak torque of flexors (PTFL) and extensors (PTEX), and total work (TW) were measured. FR was calculated as % of PTEX, PTFL, and TW in 4th versus 1st set. FR was greater (P < 0.05) in boys versus teen-males and men, and in teen-males versus men. In females, FR was greater (P < 0.05) in girls versus teen-females and women, but not different between teen-females and women. FR was not different in boys versus girls and in teen-males versus teen-females. FR for PTFL, PTEX, and TW correlated negatively (P < 0.001) with the respective peak values (r = −0.68 to −0.84), and FR for TW with peak lactate (r = −0.58 to −0.69). In addition, age correlated (P < 0.01) with FR for males (r = −0.75) and females (r = −0.55). In conclusion, FR during high-intensity intermittent exercise undergoes a gradual decline from childhood to adulthood in males, while in females the adult profile establishes at mid-puberty (14–15 years). The maturation profile of FR in males and females during development appears to reflect the maturation profiles of peak torque, short-term muscle power, and lactate concentration after exercise. T. Tsirini and A. Zafeiridis contributed equally to this work.     

Eosinophilic infiltration in the nasal mucosa of rhinitis patients: is it affected by the presence of asthma or the allergic status of the patients?

BACKGROUND: Asthma and rhinitis often coexist, and there is evidence to suggest that they have similar histopathologic features. OBJECTIVE: To examine whether the inflammatory infiltration in the nasal mucosa in rhinitis is affected by the presence of asthma and allergy. METHODS: Nasal mucosa biopsy samples were collected from 44 individuals: 18 with rhinitis and asthma (9 allergic and 9 nonallergic), 16 with rhinitis and no asthma (8 allergic and 8 nonallergic), and 10 nonallergic control subjects. The alkaline phosphatase-anti-alkaline phosphatase method was applied to 6-microm-thick cryostat sections using monoclonal antibodies against T cells (CD4 and CD8) and eosinophils (EG2). Slides were counted blindly, and results are expressed as cells per high-power field. RESULTS: Eosinophil counts were higher in the nasal mucosa of rhinitic patients vs controls. No differences in cellular infiltration were detected between rhinitic patients with and without asthma or between allergic and nonallergic patients. A trend toward higher CD4+ T-cell counts in the nasal mucosa of rhinitic patients was observed, whereas no differences were noted in CD8+ T-cell infiltration among the groups. CONCLUSION: Inflammatory infiltration, characterized by the presence of eosinophils and CD4+ T cells, was similar in the nasal mucosa in noninfectious rhinitis irrespective of the presence of asthma or the allergic status of the patient.     

Antagonist moment of force during maximal knee extension in pubertal boys: effects of quadriceps fatigue

The examination of the moment exerted by the hamstrings during maximum isokinetic knee extensor tests is useful when comparing isokinetic strength and muscle activity patterns between children and adults. The purpose of this study was to examine the effect of antagonist moment of the hamstrings on the isokinetic moment of the knee extensors in pubertal children and to determine whether this effect is altered following a fatigue task. Eighteen healthy pubertal males [age 14.3 (0.5) years] performed 34 maximal isokinetic concentric efforts of the knee extensors at 60°·s⁻¹. The average moment of force and electromyographic (aEMG) signal of vastus medialis (VM), vastus lateralis (VL) and biceps femoris (BF) at 11–30°, 31–50°, 51–70° and 71–90° of knee flexion were calculated for each repetition. The hamstrings antagonist moment was determined before and after the fatigue task by fitting the aEMG–moment relationship at different levels of muscle effort using second-degree polynomials. The percentage contribution of the antagonist moment to the resultant joint moment ranged from 7.1 % to 60.4 % throughout the range of motion, with the highest percentage observed close to full knee extension (11–30°). The antagonist effect was significantly greater during concentric tests of the knee extensors compared to the corresponding eccentric tests (p<0.05). Following the fatigue test, there was an overall decline of the resultant joint moment, but no changes in the predicted hamstrings moment were observed. These results indicate that when testing maximal knee extensor isokinetic strength in pubertal boys, activity of the hamstrings implies a reduction of the net extensor moment as compared to the isolated capacity of the knee extensors. However, this antagonist effect is not altered following the performance of an isokinetic fatigue knee extension task. Electronic Publication     

Functional brain networks of patients with epilepsy exhibit pronounced multiscale periodicities,which correlate with seizure onset

Epileptic seizure detection and prediction by using noninvasive measurements such as scalp EEG signals or invasive, intracranial recordings, has been at the heart of epilepsy studies for at least three decades. To this end, the most common approach has been to consider short‐length recordings (several seconds to a few minutes) around a seizure, aiming to identify significant changes that occur before or during seizures. An inherent assumption in this approach is the presence of a relatively constant EEG activity in the interictal period, which is interrupted by seizure occurrence. Here, we examine this assumption by using long‐duration scalp EEG data (21–94 hr) in nine patients with epilepsy, based on which we construct functional brain networks. Our results reveal that these networks vary over time in a periodic fashion, exhibiting multiple peaks at periods ranging between 1 and 24 hr. The effects of seizure onset on the functional brain network properties were found to be considerably smaller in magnitude compared to the changes due to these inherent periodic cycles. Importantly, the properties of the identified network periodic components (instantaneous phase) were found to be strongly correlated to seizure onset, especially for the periodicities around 3 and 5 hr. These correlations were found to be largely absent between EEG signal periodicities and seizure onset, suggesting that higher specificity may be achieved by using network‐based metrics. In turn, this implies that more robust seizure detection and prediction can be achieved if longer term underlying functional brain network periodic variations are taken into account.     

Influence of residual alveolar bone height on implant stability in the maxilla: an experimental animal study

Aims/Background: Empirically, for implant placement associated with sinus floor augmentation, a minimum of five mm of residual crestal bone height has been recommended in order to achieve sufficient initial implant stability. It has been the aim of the study to test this assumption in an experimental animal trial. Material and methods: In eight mini pigs, three premolars and two molars were removed on one side of the maxilla. Three months later the animals were assigned to four groups of two animals each. A cavity was created at the base of the alveolar process so that the residual bone height was reduced to 2, 4, 6 and 8 mm, respectively. The coronal part of the alveolar crest remained unchanged. An inlay augmentation procedure was carried out using a particulated autogenous bone graft from the iliac crest, and six implants (Xive, diameter 3.8 mm, length 13 mm) were placed. Implant stability was assessed by resonance frequency analysis at the time of implant placement (T0), after 6 months of unloaded healing (T1) and after 6 months of functional loading (T2). Results: During follow‐up, two implants were lost in sites with a residual alveolar bone height of 2 mm. At the time of implant placement, resonance frequencies were 6754.4±268, 6500.3±281.5, 6890.3±255.4 and 7877.9±233.7 Hz for residual bone heights of 2, 4, 6 and 8 mm, respectively. At stage‐two surgery and after 6 months of functional loading, resonance frequencies were 6431.7±290.8, 6351.8±437.6, 6213.4±376.2 and 6826.8±458.9 Hz vs. 6171±437.4, 6047±572.4, 6156.7±272.6 and 6412.8±283.5 Hz. Statistical analysis revealed an association of residual alveolar height and implant stability at T0 and T1 only (P<0.01), while bone height was not found to influence implant survival. Conclusion: The results of the present trial demonstrate an association of alveolar bone height and implant stability at the time of implant placement and stage‐two surgery. Yet the assumption that 5 mm of residual crestal bone height is a relevant threshold for simultaneous implant placement and sinus floor augmentation is not supported from an experimental point of view.     

Natalizumab and HSV meningitis

Natalizumab (Tysabri, Biogen Idec and Elan Pharmaceuticals) is a monoclonal antibody approved for use in patients with relapsing multiple sclerosis (MS) as well as moderate to severe Crohn’s disease. We report the first case of a patient with a history of MS, on monthly natalizumab, who developed HSV-2 meningitis. We discuss the mechanism of action of natalizumab and review what is known about the reactivation of herpes infection in association with this medication. The question of herpes simplex virus (HSV) and varicella zoster virus (VZV) prophylaxis for patients is raised.