Differential vulnerability of white matter structures to experimental infantile hydrocephalus detected by diffusion tensor imaging

Purpose

The differential vulnerability of white matter (WM) to acute and chronic infantile hydrocephalus and the related effects of early and late reservoir treatment are unknown, but diffusion tensor imaging (DTI) could provide this information. Thus, we characterized WM integrity using DTI in a clinically relevant model.

Methods

Obstructive hydrocephalus was induced in 2-week-old felines by intracisternal kaolin injection. Ventricular reservoirs were placed 1 (early) or 2 (late) weeks post-kaolin and tapped frequently based solely on neurological deficit. Hydrocephalic and age-matched control animals were sacrificed 12 weeks postreservoir. WM integrity was evaluated in the optic system, corpus callosum, and internal capsule prereservoir and every 3 weeks using DTI. Analyses were grouped as acute (<6 weeks) or chronic (≥6 weeks).

Results

In the corpus callosum during acute stages, fractional anisotropy (FA) decreased significantly with early and late reservoir placement (p?=?0.0008 and 0.0008, respectively), and diffusivity increased significantly in early (axial, radial, and mean diffusivity, p?=?0.0026, 0.0012, and 0.0002, respectively) and late (radial and mean diffusivity, p?=?0.01 and 0.0038, respectively) groups. Chronically, the corpus callosum was thinned and not detectable by DTI. FA was significantly lower in the optic chiasm and tracts (p?=?0.0496 and 0.0052, respectively) with late but not early reservoir placement. In the internal capsule, FA in both reservoir groups increased significantly with age (p?Conclusions All hydrocephalic animals treated with intermittent ventricular reservoir tapping demonstrated progressive ventriculomegaly. Both reservoir groups demonstrated WM integrity loss, with the CC the most vulnerable and the optic system the most resilient.     

Ultrasound-based tumor movement compensation during navigated laparoscopic liver interventions

Background

Image-guided navigation aims to provide better orientation and accuracy in laparoscopic interventions. However, the ability of the navigation system to reflect anatomical changes and maintain high accuracy during the procedure is crucial. This is particularly challenging in soft organs such as the liver, where surgical manipulation causes significant tumor movements. We propose a fast approach to obtain an accurate estimation of the tumor position throughout the procedure.

Methods

Initially, a three-dimensional (3D) ultrasound image is reconstructed and the tumor is segmented. During surgery, the position of the tumor is updated based on newly acquired tracked ultrasound images. The initial segmentation of the tumor is used to automatically detect the tumor and update its position in the navigation system. Two experiments were conducted. First, a controlled phantom motion using a robot was performed to validate the tracking accuracy. Second, a needle navigation scenario based on pseudotumors injected into ex vivo porcine liver was studied.

Result

In the robot-based evaluation, the approach estimated the target location with an accuracy of 0.4 ± 0.3 mm. The mean navigation error in the needle experiment was 1.2 ± 0.6 mm, and the algorithm compensated for tumor shifts up to 38 mm in an average time of 1 s.

Conclusion

We demonstrated a navigation approach based on tracked laparoscopic ultrasound (LUS), and focused on the neighborhood of the tumor. Our experimental results indicate that this approach can be used to quickly and accurately compensate for tumor movements caused by surgical manipulation during laparoscopic interventions. The proposed approach has the advantage of being based on the routinely used LUS; however, it upgrades its functionality to estimate the tumor position in 3D. Hence, the approach is repeatable throughout surgery, and enables high navigation accuracy to be maintained.     

Aerobic exercise affects sleep,psychological wellbeing and immune system parameters among subjects with chronic primary insomnia

BackgroundChronic primary insomnia is characterized by long-term difficulties in maintaining and initiating sleep, too early waking up, poor mood, fatigue, impaired concentration and poor quality of life. Exercise training is recommended to prevent and alleviate sleep disorders.ObjectiveThe aim of the study was to investigate the influence of aerobic exercise training on quality of sleep, psychological wellbeing and immune system among subjects with chronic primary insomnia.Material and methodsEighty previously sedentary subjects with chronic primary insomnia subjects enrolled in this study, their age ranged from 35–56 years. All participants were randomly assigned to supervised aerobic exercise intervention group (group A, n=40) or control group (group B, n=40). Polysomnographic recordings for sleep quality assessment, Beck Depression Inventory (BDI), Profile of Mood States(POMS), Rosenberg Self-Esteem Scale (RSES), number of CD3+, CD4+, CD8+ T cells count and CD4/CD8 ratio were measured before and at the end of the study after six months.ResultsThere was a significant increase in the total sleep duration, sleep efficiency and sleep onset latency in group(A) after six months of aerobic exercise training, while, wake time after sleep onset and rapid eye movement (REM) latency significantly reduced after six months of aerobic training compared with values obtained prior to aerobic exercise training. Also, the mean values of BDI, POMS, CD3 count, CD4 count and CD8 count decreased significantly and the mean value of RSES significantly increased in group (A) after the aerobic exercise training, while the results of the control group were not significant. Moreover, there were significant differences between both groups at the end of the study.ConclusionExercise training can be considered as a non-pharmacological modalty for modifying sleep quality, psychological wellbeing and immune system among subjects with chronic primary insomnia.     

Mediation of a non-proteolytic activation of complement component C3 by phospholipid vesicles

Liposomes are becoming increasingly important as drug delivery systems, to target a drug to specific cells and tissues and thereby protecting the recipient from toxic effects of the contained drug. Liposome preparations have been described to activate complement. In this study, we have investigated complement activation triggered by neutral dimyristoyl-phosphocholine (DMPC) liposomes in human plasma and whole-blood systems. Incubation in plasma led to the generation of complement activation products (C3a and sC5b-9). Unexpectedly, investigations of surface-bound C3 revealed contact activated, conformationally changed C3 molecules on the liposomes. These changes were characterized by Western blotting with C3 monoclonal antibodies, and by incubating liposomes with purified native C3 and factors I and H. Quartz crystal microbalance analysis confirmed binding of C3 to planar DMPC surfaces. In addition, we demonstrated that DMPC liposomes bound to or were phagocytized by granulocytes in a complement-dependent manner, as evidenced by the use of complement inhibitors. In summary, we have shown that C3 is activated both by convertase-dependent cleavage, preferentially in the fluid phase, by mechanisms which are not well elucidated, and also by contact activation into C3(H₂O) on the DMPC surface. In particular, this contact activation has implications for the therapeutic regulation of complement activation during liposome treatment.     

The influence of physiological matrix conditions on permanent culture of induced pluripotent stem cell-derived cardiomyocytes

Cardiomyocytes (CMs) from induced pluripotent stem (iPS) cells mark an important achievement in the development of in vitro pharmacological, toxicological and developmental assays and in the establishment of protocols for cardiac cell replacement therapy. Using CMs generated from murine embryonic stem cells and iPS cells we found increased cell–matrix interaction and more matured embryoid body (EB) structures in iPS cell-derived EBs. However, neither suspension-culture in form of purified cardiac clusters nor adherence-culture on traditional cell culture plastic allowed for extended culture of CMs. CMs grown for five weeks on polystyrene exhibit signs of massive mechanical stress as indicated by α-smooth muscle actin expression and loss of sarcomere integrity. Hydrogels from polyacrylamide allow adapting of the matrix stiffness to that of cardiac tissue. We were able to eliminate the bottleneck of low cell adhesion using 2,5-Dioxopyrrolidin-1-yl-6-acrylamidohexanoate as a crosslinker to immobilize matrix proteins on the gels surface. Finally we present an easy method to generate polyacrylamide gels with a physiological Young's modulus of 55 kPa and defined surface ligand, facilitating the culture of murine and human iPS-CMs, removing excess mechanical stresses and reducing the risk of tissue culture artifacts exerted by stiff substrates.     

Subclinical Vascular Endothelial Dysfunctions and Myocardial Changes With Type 1 Diabetes Mellitus in Children and Adolescents

Vascular endothelial dysfunction, accelerated thickening of arterial intima, and changes in ventricular functions contribute to increased cardiovascular morbidity in type 1 diabetes mellitus (T1DM). This study aimed to investigate the functional-structural changes in the arteries and myocardium together with affection of highly sensitive C-reactive protein (hsCRP), circulating endothelial cells (CECs), and vitamin C levels in children with T1DM. Also, to test the association with early atherosclerotic changes. The study included 30 children with a diagnosis of T1DM and 30 healthy subjects matched by sex, age, and body mass index. Serum lipids, HbA1c, hsCRP, vitamin C, and CECs were detected. Corrected QT interval (QTc), cardiac dimensions, and left ventricular (LV) functions were assessed using conventional echocardiography. Noninvasive ultrasound was used to measure brachial artery flow-mediated dilation (FMD) responses and carotid intima-media thickness (IMT). The QTc interval was significantly higher in the diabetic patients than in the control subjects (P < 0.001). The findings showed LV diastolic dysfunction as reflected by significantly lower early peak flow velocity, decreased E/A ratio, increased early filling deceleration time (DcT), and prolonged isovolumic relaxation time (IVRT) (P < 0.001 for each). The children with diabetes had a significantly lower FMD response, increased IMT, lower vitamin C level, higher hsCRP, and higher CEC compared with the control subjects (P < 0.001 for each). A positive correlation between CEC and HbA1c was found (P = 0.004). An alteration in myocardial function and endothelial dysfunction may begin early with the association of early atherosclerotic changes. These changes are accelerated when glycemic control is poor. The authors recommend early and close observation of children with diabetes for any alterations in cardiac and vascular endothelial function. Vitamin C supplementation may reduce the risk of complications.     

A prospective controlled evaluation of Class II division 1 malocclusions treated with fixed lingual mandibular growth modificator

Objective: To assess the net dentofacial effects of the fixed lingual mandibular growth modificator (FLMGM).Materials and Methods:The study sample comprised 38 patients with Class II/1 malocclusion and retrognathic mandible. All were in the pubertal growth spurt. Whereas FLMGM was applied to the treatment group (n  =  21, mean age  =  13.2 years), no treatment was performed on the control group (n  =  17, mean age  =  12.5 years). Skeletal and dentoalveolar changes were assessed on digital lateral cephalograms obtained at the beginning and end of the treatment/observation period of 8 months. Paired and independent t-tests were used to assess the differences within and between groups.Results:Maxillary growth was not affected by FLMGM treatment, which resulted in a significant overjet reduction of 4.1 mm, an increase in total mandibular length (Co-Gn) of 2.3 mm, chin advancement of 1.6°, and upper incisor retroclination of 4.0°. A reduction of 2.4° in ANB was largely due to an increase of 1.8° in SNB. Favorably, the lower incisors were obviously retroclined by 4.5°. The changes in the vertical skeletal relationships were negligible.Conclusion:FLMGM was effective in treating growing Class II/1 patients and produced favorable dentofacial effects, with the matched untreated sample showing minimal changes. Lower incisor retroclination was a benefit of FLMGM treatment.     

Impact of Mild versus Moderate Intensity Aerobic Walking Exercise Training on Markers of Bone Metabolism and Hand Grip Strength in Moderate Hemophilic A Patients

Background

Patients with hemophilia A have low bone density than healthy controls. It is now widely recognized that physical activity and sports are beneficial for patients with hemophilia.

Objective

To compare the effects of mild and moderate intensity treadmill walking exercises on markers of bone metabolism and hand grip strength in male patients with moderate hemophilia A.

Material and Methods

Fifty male patients with moderate hemophilia, and age range from 25 to 45 years. The subjects were randomly assigned into 2 equal groups; the first group (A) received moderate intensity aerobic exercise training. The second group (B) received mild intensity aerobic exercise training.

Results

There was a 32.1% and 24.8% increase in mean values of serum calcium and hand grip strength respectively and 22.7 % reduction in mean values of parathyroid hormone in moderate exercise training group (A). While there was a 15.1 % and 15 % increase in mean values of Serum Calcium and Hand grip strength respectively and 10.3 % reduction in mean values of parathyroid hormone in mild exercise training group(B). The mean values of serum calcium and hand grip strength were significantly increased, while the mean values of parathyroid hormone were significantly decreased in both groups . There were significant differences between mean levels of the investigated parameters in group (A) and group (B) after treatment.

Conclusion

Moderate intensity aerobic exercise training on treadmill is appropriate to improve markers of bone metabolism and hand grip strength in male patients with hemophilia A.