Laser Doppler anemometry measurements of steady flow through two bi-leaflet prosthetic heart valves

Introduction

In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench.

Objective

To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream.

Methods

To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. ) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements.

Results

It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found.

Conclusions

Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM) is superior to the 21 AJ - 501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves.     

Phototherapy and resistance training prevent sarcopenia in ovariectomized rats

The aim of this study was to histologically and biochemically analyze the effects of light-emitting diode therapy (LEDT) associated with resistance training to prevent sarcopenia in ovariectomized rats. Forty female Wistar rats (12 months old, 295–330 g) were bilaterally ovariectomized and divided into four groups (n?=?10 per group): control–sedentary (C), resistance training (T), LEDT–sedentary (L), and LEDT plus resistance training (LT). Trained rats performed a 12-week water-jumping program (3 days per week) carrying a load equivalent to 50–80 % of their body mass strapped to their back. Depending on the group protocol, the LED device (850 nm, 100 mW, 120 J/cm², spot size 0.5 cm²) was used either as the only method or after the resistance training had been performed. The device was used in the single point contact mode (for 10 min). The irradiated region was the center of the greater trochanter of the right femur and the middle third of the rectus femoris muscle was subsequently analyzed histomorphometrically. Significant increases (p?<?0.05) were noted for the muscle volume of the T (68.1?±?19.7 %), the L (74.1?±?5.1 %), and the LT (68.2?±?11.5 %) groups compared to the C group (60.4?±?5.5 %). There were also significant increases in the concentrations of IGF-1, IL-1, and TNF-α in the muscles of the treated groups (p?<?0.05). Animals in the LT group showed a significant increase in IL-6 compared to T, L, and C groups (p?<?0.05). These findings suggest that resistance training and LEDT can prevent sarcopenia in ovariectomized rats.     

Leptin as a link between the immune system and kidney‐related diseases: leading actor or just a coadjuvant?

Food intake and nutritional status modify the physiological responses of the immune system to illness and infection and regulate the development of chronic inflammatory processes, such as kidney disease. Adipose tissue secretes immune‐related proteins called adipokines that have pleiotropic effects on both the immune and neuroendocrine systems, linking metabolism and immune physiology. Leptin, an adipose tissue‐derived adipokine, displays a variety of immune and physiological functions, and participates in several immune responses. Here, we review the current literature on the role of leptin in kidney diseases, linking adipose tissue and the immune system with kidney‐related disorders. The modulation of this adipose hormone may have a major impact on the treatment of several immune‐ and metabolic‐related kidney diseases.     

Double-masked randomized clinical trial evaluating the effect of a triclosan/copolymer dentifrice on periodontal healing after one-stage full-mouth debridement

Background: This study evaluates the effect of triclosan/copolymer dentifrice on the 6‐month clinical response of patients with generalized severe chronic periodontitis (GSCP) treated with one‐stage, full‐mouth ultrasonic debridement (FMUD). Methods: Thirty patients diagnosed with GSCP (≥8 teeth presenting probing depth [PD] ≥5 mm and bleeding on probing [BOP]) were selected and randomly allocated to a control group (n = 15) subjected to FMUD and daily use of a placebo dentifrice or to a test group (n = 15) subjected to FMUD and daily use of a triclosan/copolymer dentifrice. Patients were analyzed for the following parameters: full‐mouth plaque index (FMPI), full‐mouth BOP score (FMBS), gingival recession, PD, and clinical attachment level (CAL). Patients were evaluated at 3 and 6 months by a calibrated and masked examiner. Results: Initially, the groups presented similar periodontal conditions, with no significant differences in any of the parameters evaluated (P >0.05). In both groups, improvements in all periodontal parameters (P <0.05) were seen at the completion of the experimental period. Additionally, the test group showed lower FMPI (3 months) and FMBS (3 and 6 months) than the control group (P <0.05). Moreover, the CAL gain was significantly greater in the test group, especially at initially deep pockets (PD ≤7 mm). Whereas in the control group the CAL gain in deep pockets was 2.7 ± 0.6 mm, in the test group the CAL gain was 3.6 ± 1.4 mm (P <0.05). Conclusion: Within the limits of the present study, the use of triclosan/copolymer dentifrice promoted additional clinical benefits in the treatment of GSCP treated by one‐stage FMUD.     

Late brain alterations in sepsis‐survivor rats

Central nervous system (CNS) dysfunction secondary to sepsis is characterized by long‐term cognitive impairment. It was observed that oxidative damage, energetic metabolism impairment, and cytokine level alteration seen in early times in an animal model of sepsis may persist for up to 10 days and might be associated with cognitive damage. In order to understand these mechanisms, at least in part, we evaluated the effects of sepsis on cytokine levels in the cerebrospinal fluid (CSF), oxidative parameters, and energetic metabolism in the brain of rats at both 30 and 60 days after sepsis induction by cecal ligation and perforation (CLP). To this aim, male Wistar rats underwent CLP with “basic support” or were sham‐operated. Both 30 and 60 days after surgery, the CSF was collected and the animals were killed by decapitation. Then, the prefrontal cortex, hippocampus, striatum, and cortex were collected. Thirty days after surgery, an increase of IL‐6 level in the CSF; an increase in the thiobarbituric acid‐reactive species (TBARS) in prefrontal cortex and a decrease in hippocampus, striatum, and cortex; a decrease of carbonyl protein formation only in prefrontal cortex and an increase in striatum; and an increase in the complex IV activity only in hippocampus were observed. Sixty days after sepsis, an increase of TNF‐α level in the CSF; a decrease of TBARS only in hippocampus; an increase of carbonyl protein formation in striatum; and a decrease of complex I activity in prefrontal cortex, hippocampus, and striatum were observed. These findings may contribute to understanding the role of late cognitive impairment. Further studies may address how these findings interact during sepsis development and contribute to CNS dysfunction. Synapse 67:786–793, 2013. © 2013 Wiley Periodicals, Inc.     

Caucasian Familial Moyamoya Syndrome With Rare Multisystemic Malformations

Moyamoya disease is an idiopathic progressive steno-occlusive disorder of the intracranial arteries located at the base of the brain. It is associated with the development of compensatory extensive network of fine collaterals. Moyamoya disease is considered syndromic when certain genetic or acquired disorders such as polycystic kidney disease, neurofibromatosis, or meningitis are also present. Although the genetic contribution in moyamoya is indisputable, its cause and pathogenesis remain under discussion. Herein, we report a rare occurrence of moyamoya syndrome in two European Caucasian siblings in association with unusual multisystemic malformations (polycystic kidney disease in one, and intestinal duplication cyst in the other). The karyotype was normal. No mutation in the RFN213 gene was found, and none of the HLA types linked to moyamoya disease or described in similar familial cases were identified. By describing these multisystemic associations, polycystic kidney disease for the second time, and intestinal malformation for the first time in the literature, our report expands the phenotypic variability of moyamoya syndrome. The coexistence of disparate malformations among close relatives suggests an underlying common genetic background predisposing to structural or physiological abnormalities in different tissues and organs.