Exploring known risk factors for pressure injury with visual technology

This research has identified that the use of visual technology can support the correlation between peak interface pressure and pressure gradients in the understanding of deep tissue injury. In addition as a pilot study the visual assessment of buttock shape has demonstrated potential for identifying risk of ischial or sacral pressure injury.

A head mountable deep brain stimulation device for laboratory animals

Deep brain stimulation has emerged as an effective method to treat certain medical conditions. Electrical charges are injected into the target tissue through a conducting electrode exciting the tissue. A variety of DBS devices have been developed based on different operation principles. Majority of these devices, however, employ complex circuitry and are bulky. In clinical trials, laboratory animals need to freely move around and perform activities whilst receiving brain stimulation for days. This paper presents a simple lightweight head mountable deep brain stimulation device that can be carried by the animal during the course of a clinical trial. The device produces continuous current pulses of specific characteristics. It employs passive charge balancing to minimize undesirable effects on the target tissue. The device is constructed and its performance tested.

Compact stacked planar inverted-F antenna for passive deep brain stimulation implants

A compact meandered three-layer stacked circular planar inverted-F antenna is designed and simulated at the UHF band (902.75 – 927.25 MHz) for passive deep brain stimulation implants. The UHF band is used because it offers small antenna size, and high data rate. The top and middle radiating layers are meandered, and low cost substrate and superstrate materials are used to limit the radius and height of the antenna to 5 mm and 1.64 mm, respectively. A dielectric substrate of FR-4 of εr= 4.7 and δ= 0.018, and a biocompatible superstrate of silicone of er= 3.7 and d= 0.003 with thickness of 0.2 mm are used in the design. The resonance frequency of the proposed antenna is 918 MHz with a bandwidth of 24 MHz at return loss of −10 dB in free space. The antenna parameter such as 3D gain pattern of the designed antenna within a skin-tissue model is evaluated by using the finite element method. The compactness, wide bandwidth, round shape, and stable characteristics in skin make this antenna suitable for DBS. The feasibility of the wireless power transmission to the implant in the human head is also examined.

A low power micro deep brain stimulation device for murine preclinical research

Deep brain stimulation has emerged as an effective medical procedure that has therapeutic efficacy in a number of neuropsychiatric disorders. Preclinical research involving laboratory animals is being conducted to study the principles, mechanisms, and therapeutic effects of deep brain stimulation. A bottleneck is, however, the lack of deep brain stimulation devices that enable long term brain stimulation in freely moving laboratory animals. Most of the existing devices employ complex circuitry, and are thus bulky. These devices are usually connected to the electrode that is implanted into the animal brain using long fixed wires. In long term behavioral trials, however, laboratory animals often need to continuously receive brain stimulation for days without interruption, which is difficult with existing technology. This paper presents a low power and lightweight portable microdeep brain stimulation device for laboratory animals. Three different configurations of the device are presented as follows: 1) single piece head mountable; 2) single piece back mountable; and 3) two piece back mountable. The device can be easily carried by the animal during the course of a clinical trial, and that it can produce non-stop stimulation current pulses of desired characteristics for over 12 days on a single battery. It employs passive charge balancing to minimize undesirable effects on the target tissue. The results of bench, in-vitro, and in-vivo tests to evaluate the performance of the device are presented.

Mood regulatory actions of nucleus accumbens deep brain stimulation

The mood regulatory mechanisms of deep brain stimulation (DBS)therapy are yet to be fully understood. DBS is shown to have antidepressant actions in severe, treatment-resistant depression (TRD).Interestingly, DBS of mesoaccumbens neurologic targets, includingthe nucleus accumbens (NAc), have also been shown to induce mania in vulnerable individuals. The nucleus accumbens (NAc) is a critical node in the mesocorticolimbic system and plays a major role in mediating antidepressant behavioral responses in the forced swim test (FST), a preclinical screen for antidepressant efficacy. This study investigates the antidepressant effects of NAc DBS in an established animal model of TRD. Wistar rats were divided into 4 groups: TRD-DBS (n = 9), TRD-Sham (n = 8), TRD (n = 10), and Control (n = 10). Bilateral stimulating electrodes were implanted into the NAc of TRD-Sham and TRD-DBS animals. Antidepressant-resistance and depression behaviors were induced through adrenocorticotropic-hormone (ACTH-(1–24); 100 lg/day; 2nd and 3rd weeks) administration and concurrent social isolation (all 3 weeks) respectively. DBS was administered throughout the 2nd week of ACTH treatment via a back mounted rodent DBS system. 24-hour locomotor activity counts were obtained using infrareddetectors and weekly sucrose preference tests were performedthroughout the 3 week protocol. Open field and FST were completedat the end of the 3 weeks. Brains were then removed and stored at 80°C. NAc tissue levels of brain-derived and glialderived neurotrophic factors (BDNF and GDNF, respectively) were quantified using western blot. Results demonstrate significant increases in locomotor activity for TRD-DBS animals (DBS-Vs-Sham: p = 0.0248). Lowered immobility was observed during FST for TRD-DBS animals (DBS-Vs-Sham: p = 0.0188). ACTHinduced BDNF expression increased in the outer region substructure NAc-shell (p = 0.0487) and decreased in the inner region substructure NAc-core (p = 0.0275) compared to controls. These datasupport antidepressant actions of NAc DBS in TRD. Local changes in neurotrophic factors may contribute to these mechanisms. Importantly, observed increases in locomotor activity over the 3 weeks highlight the potential for mesoaccumbens DBS to impact behaviors such as locomotor activity which may contribute to risk for induction of mania. Preliminary analysis of concurrent effects of daily dopamine reuptake inhibitor GBR12909 (16 mg/kg) administration coupled with NAc DBS demonstrates dopamine-mediated augmentation of these mania-like behaviors.

First comprehensive multi-tissue transcriptome of Cherax quadricarinatus (Decapoda: Parastacidae) reveals unexpected diversity of endogenous cellulase

The Australian freshwater crayfish species, Cherax quadricarinatus Von Martens, 1868, is an important commercial and invasive species that is also being increasingly used as a model organism to address important and interesting questions in crustacean biology. Through deep sequencing of the transcriptome of C. quadricarinatus from the hepatopancreas and four other tissues, we examine the evolution of endogenously transcribed cellulase genes and provide new insights into controversial issues regarding the nutritional biology of crayfishes. A cluster assembly approach yielded one of the highest quality transcriptome assemblies for a decapod crustacean to date. A total of 206,341,872 reads with an average read length of 80 bp were generated from sequencing the transcriptomes from the heart, kidney, hepatopancreas, nerve, and testis tissues. The assembled transcriptome contains a total of 44,525 transcripts. A total of 65 transcripts coding for carbohydrate-active enzymes (CAZy) were identified based on hidden Markov model (HMM), and a majority of them display high relative transcript abundance in the hepatopancreas tissue, supporting their role in nutrient digestion. Comprehensive phylogenetic analyses of proteins belonging to two main glycosyl hydrolase families (GH9 and GH5) suggest shared ancestry of C. quadricarinatus cellulases with other characterized crustacean cellulases. Our study significantly expands the number of known crustacean-derived CAZy-coding transcripts. More importantly, the surprising level of evolutionary diversification of these proteins in C. quadricarinatus suggests that these enzymes may have been of critical importance in the adaptation of freshwater crayfishes to new plant-based food sources as part of their successful invasion of freshwater systems from marine ancestors.