Homoarginine test for evaluation of metabolic renal dysfunction

Low plasma L-homoarginine (hArg) concentration is an independent predictor of adverse cardiovascular outcomes and overall mortality, as well as the progression of chronic kidney disease (CKD). The enzyme L-arginine:glycinamidinotransferase (AGAT, EC 2.1.4.1) acts in the mitochondrial membrane of the renal tubular epithelium, forming the precursor of creatine, guanidinoacetic acid, and additionnaly by-product hArg. As it was shown recently, there is a decreased level of hArg in the late stages of CKD, however, the the level of hArg in the early stages of CKD remained unexplored. The aim of this study was to determine the diagnostic threshold levels of hArg in the blood of patients with stages 1 and 2 of CKD. In patients with the initial stages of CKD (n = 44) at the age of 58 (45-67) years, compared with the group of donors of 55 (42-58) years (n = 30), a significant decrease of hArg level was found. In the subgroup with stage CKD 2, the cut-off point of 1.59 μM threshold was characterized by greater sensitivity and specificity than in the subgroup with stage CKD 1 with 1.66 μM threshold level of hArg. For the full group, the hArg cut-off threshold was 1.60 μM, which is about to 0.2 μM lower than the lower limit of the reference interval for healthy individuals. It can be assumed that even before the formation of symptoms of proteinuria and albuminuria, a significant part of individuals from population cohort develops a state of decreased AGAT activity, since the expression of this enzyme is associated with a certain regulatory feedback inhibition at the body level. As a result of the study, it can be noted that in patients with early stages of CKD in the age group 45-67 years, there is a disturbance of the kidneys metabolic function. These metabolic changes can be detected by testing the level of hArg.

Beyond-dipole van der Waals contributions within the Many-Body Dispersion framework

By introducing a suitable range-separation of the Coulomb coupling in analogy to [A. Ambrosetti et al. JCP 140, 18A508 (2014)], here we extend the Many-Body Dispersion (MBD) approach to include beyond-dipole van der Waals interactions at a full many-body level, in combination with semi-local density functional theory. A reciprocal-space implementation is further introduced in order to efficiently treat periodic systems. Consistent reliability is found frommolecular dimers to large supramolecular complexes and two-dimensional systems. The large weight of both many-body effects and multipolar terms illustrates how a correct description of vdW forces in large-scale systems requires full account of both contributions, beyond standard pairwise dipolar approaches.

Morphological and histopathological studies of Thelandros chalcidae (Oxyuroidea: Pharyngodonidae) infecting Chalcides ocellatus from Egypt

Background Thelandros (Pharyngodonidae) is a gastrointestinal nematode parasite with a life cycle including lizards as main hosts. Thelandros chalcidae collected from the large intestine of the Egyptian ocellated skink, Chalcides ocellatus were described and illustrated by light and scanning electron microscopes. Seven out of fifteen (46.66%) of the examined lizards were found to be naturally infected. Also, host intestinal tissues were evaluated from hematoxylin/eosin-stained sections to describe any histopathological changes. Results Microscopic examinations revealed that the recovered pharyngodonid species characterized by mouth with triangular opening and surrounded by six simple lips, the cuticle had regular transverse annulations extending from the posterior margin of the lips to the end of the body. Male was cylindrical with distinct truncated posterior end and measured 1.59–1.86 (1.64 ± 0.10) long and 0.29–0.37 (0.32 ± 0.01) in maximum width at the level of mid-body. Female measured 1.72–2.43 (1.85 ± 0.2) long and 0.36–0.49 (0.42 ± 0.01) maximum width at the mid-body level, terminated posteriorly in a short, stout spike. Histological studies observed structural alterations represented by leukocytic infiltration, villi atrophy, and muscularis degeneration. These changes were indicative of inflammatory and degenerative reaction due to Thelandros chalcidae infection. Conclusion The present morphological study revealed that the recovered pharyngodonid species was Thelandros chalcidae causing pathological alterations in Chalcides ocellatus intestinal tissues.

Design of a powered full-body exoskeleton for physical assistance of elderly people

The development of full-body exoskeletons has been limited due to design complexities, mechanical integration intricacies, and heavier weight, among others. Consequently, very few full-body powered exoskeletons were developed to address these challenges, in spite of increasing demand for physical assistance at full-body level. This article presents an overall design and development of a powered full-body exoskeleton called “FB-AXO.” Primarily, FB-AXO consists of two main subsystems, a lower-body and an upper-body subsystem connected together through waist and spine modules. FB-AXO is developed for the support of weaker ageing adults so that they can continue functioning their daily activities. At the onset of the project, a set of functional and design requirements has been formulated with an extensive end-user involvement and then used in realizing the FB-AXO. The final FB-AXO design comprises of 27 degrees of freedom, of which 10 are active and 17 are passive, having a total system weight of 25 kg. Overall, the article elaborates comprehensively the design, construction, and preliminary testing of FB-AXO. The work effectively addresses design challenges including kinematic compatibility and modularity with innovative solutions. The details of the mechanics, sensors, and electronics of the two subsystems along with specifics of human-exoskeleton interfaces and ranges of motion are also provided. The FB-AXO exoskeleton effectively demonstrated to assist full-body motions such as normal walking, standing, bending as well as executing lifting and carrying tasks to meet the daily living demands of older users.

Age-related features of developing insulin resistance and adipocyte sensitivity to insulin in rats with induced metabolic syndrome

Old age and insulin resistance accompanying metabolic syndrome are significant factors in the development of cardiovascular pathology.Aim. The aim of the study was to identify the age-related characteristics of developing insulin resistance on the body level and insulin resistance in rat adipocytes in animals with induced metabolic syndrome.Material and Methods. The study was carried out on male Wistar rats, which were divided into the following groups: group 1 (n = 14) comprised intact rats aged 150 days at the end of study; group 2 (n = 14) comprised rats aged 150 days at the end of 90-day period on diet with high contents of carbohydrates and fats (HCHFD); group 3 (n = 14) comprised intact rats aged 540 days at the end of the study; group 4 (n = 14) comprised rats aged 540 days after the end of 90-day HCHFD. Diet composition was as follows: 16% proteins, 21% fats, 46% carbohydrates including 17% fructose, 0.125% cholesterol, and replacement of drinking water with a 20%-fructose solution. At the end of the diet, body and organ weights were measured, and contents of glucose, insulin, triglycerides, serum leptin, and liver triglycerides were assessed. Epididymal adipose tissue adipocytes were isolated enzymatically. The content of reactive oxygen species (ROS) was investigated using 2,3-dihydrodichlorofluorescein diacetate. Increased ROS production and lipolysis inhibition in response to insulin were observed.Results. The signs of metabolic syndrome were observed in both age groups of HCHFD animals and included visceral obesity, hyperglycemia, and insulin resistance measured by homeostatic model assessment of insulin resistance (HOMA-IR). However, the obesity indicators were more pronounced in the group of young rats, whereas the signs of insulin resistance prevailed in older rats. Leptinemia directly correlated with HOMA-IR (rSp = 0.485, p = 0.03). Insulin resistance of adipocytes was observed in rats older than 540 days after the HCHFD.Conclusion. The obtained results suggested that age was a risk factor for the development of insulin resistance on the body level. Aging resulted in a decrease in the adipocyte sensitivity to insulin in metabolic syndrome. An increase in leptin may be a possible mechanism for worsening of insulin resistance with age.

Embryotoxic activity of 3C protease of human hepatitis A virus in developing Danio rerio embryos

The 3C protease is a key factor in picornavirus-induced pathologies with a comprehensive action on cell targets. However, the effects induced by the enzyme have not been described at the organismic level. Here, the model of developing Danio rerio embryos was used to analyze possible toxic effects of the 3C protease of human hepatitis A virus (3Cpro) at the whole-body level. The transient 3Cpro expression had a notable lethal effect and induced a number of specific abnormalities in Danio rerio embryos within 24 h. These effects are due to the proteolytic activity of the enzyme. At the same time, the 3Cpro variant with reduced catalytic activity (3Cmut) increased the incidence of embryonic abnormalities; however, this effect was smaller compared to the native enzyme form. While the expression of 3Cmut increased the overall rate of abnormalities, no predominance of specific ones was observed. The data obtained point to a presence significant impact of picornavirus 3Cprotease at the whole-organism level and make contribution to the study of the infectious process caused by human hepatitis A virus.

Foramen Magnum Meningioma—The Attainment of the Intra-Arachnoidal Dissection: 2-Dimensional Operative Video

Ventral foramen magnum meningiomas are a forbidding lesion. The stake is so high with a risk of devastating paralysis and respiratory failure. Careful preoperative clinical and radiological evaluation is necessary to implement the best treatment plan. Successful surgical intervention depends on paying high attention to minute details throughout the case, from intratracheal intubation to extubation. The neural head-on-neck position is critical to avoid further medullary compression at intubation and positioning.1 Extensive neurophysiological monitoring, including somatosensory, motor, brainstem evoked potential, and cranial nerves, during the positioning and throughout the case, is extremely helpful to detect early signs of dysfunction.1 To expose and access ventral tumors, partial condyle resection and vertebral artery transposition are invaluable techniques.2,3 Preservation and minute manipulation of the vital neurovascular structures at this junction that includes the medullar, anterior spinal artery, posterior inferior cerebellar artery, vertebral junction perforators, and lower cranial nerves are essential for good outcomes. This is achieved by microsurgical intra-arachnoidal dissection under high magnification and after debulking the tumor to establish that plane.1,3,4 The demonstration of this technique is the purpose of this article. We demonstrate these surgical tenets applied to the resection of a large ventral foramen magnum meningioma extending from the midclivus to the C3 vertebral body level in a 54-yr-old female presenting with swallowing difficulties. The patient consented to the surgical intervention and the publication of her images. Image at 1:38 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998.

The influence of in-vivo mechanical behaviour of the Achilles tendon on the mechanics, energetics and apparent efficiency of bouncing gaits

In this study, we used kinematic, kinetic, metabolic and ultrasound analysis to investigate the role of elastic energy utilisation on the mechanical and physiological demands of a movement task that primarily involves the plantar-flexors muscles (hopping) to determine the contribution of tendon work to total mechanical work and its relationship with apparent efficiency (AE) in bouncing gaits. Metabolic power (PMET) and (positive) mechanical power at the whole-body level (PMEC) were measured during hopping at different frequencies (2, 2.5, 3 and 3.5 Hz). The (positive) mechanical power produced during the Achilles tendon recoil phase (PTEN) was obtained by integrating ultrasound data with an inverse dynamic approach. As a function of hopping frequency, PMEC decreased steadily and PMET exhibited a U-shape behaviour, with a minimum at about 3 Hz. AE (PMEC/PMET) showed an opposite trend and was maximal (about 0.50) at the same frequency when also PTEN was the highest. Positive correlations were observed: i) between PTEN and AE (AE=0.22+0.15.PTEN, R2=0.67, P<0.001) and the intercept of this relationship indicates the value of AE that should be expected when tendon work is nil; ii) between AE and tendon gearing (Gt=DMTU length/Dmuscle belly length) (R2=0.50, P<0.001), a high Gt indicates that the muscle is contracting more isometrically thus allowing the movement to be more economical (and efficient); iii) between Gt and PTEN (R2=0.73, P<0.001) and this indicates that Gt could play an important role in the tendon's capability to store and release mechanical power.

EVALUATION OF D-ALLETHRIN IN THE THERMACELL MOSqUITO REPELLENT DEVICE AGAINST THE LONE STAR TICK UNDER LABORATORY CONDITIONS

D-allethrin vapor generated from a personal mosquito repellent device (Thermacell MR300) was evaluated for its effectiveness to repel the lone star tick, Amblyomma americanum (adults and nymphs) when released at tick body level in a wind tunnel and in an olfactometer. In the wind tunnel 48.5% of ticks moved upwind when only attractant lure was present, while only 30.8% moved upwind when d-allethrin repellent was present with the lure. In the olfactometer strong repellency of d-allethrin vapor to adults was observed, but the effect was reduced with nymphs. Results of this study showed that d-allethrin vapor generated by the Thermacell MR300 pad could be used to reduce movement of ticks towards a host under some conditions.