In Vitro Evaluation of Ventricular Cannulation for Rotodynamic Cardiac Assist Devices

The influence of positioning and geometry of ventricular cannulas for contemporary continuous flow Left Ventricular Assist Devices (LVADs) was evaluated in a non-beating isolated heart preparation with borescopic visualization. Preload and LVAD flow were varied to evaluate degrees of ventricular decompression up to the point of ventricular collapse. The performance of a flanged cannula was compared to a conventional bevel-tipped cannula: quantitatively by the maximal flow attainable, and qualitatively by visualization of fluid tracer particles within the ventricular chamber. Three forms of ventricular suck-down occurred: concentric collapse, gradual entrainment and instantaneous entrainment. In some circumstances, unstable oscillations of the ventricle were observed prior to complete collapse. Under conditions of low preload, the flanged cannula demonstrated less positional sensitivity, provided greater flow, and exhibited fewer areas of stagnation than the beveled cannula. These observations warrant further consideration of a flanged ventricular cannula to mitigate complications encountered with conventional cannulae.

Racemates revisited: heterochiral assemblies and the example of DL-thalidomide

The existence of racemic compounds, comprised of pairs of opposite enantiomers as discrete molecular entities, has been accepted for over a century. However, their ability to remain as associated dimers when in solution is uncertain, if not generally doubted. In this article, data has been assembled to provide evidence for the presence of intact dimeric heterochiral assemblies in solution and presents DL-thalidomide as a probable example of this phenomenon.

Dog bites man or man bites dog? The enigma of the amino acid conjugations

The proposition posed is that the value of amino acid conjugation to the organism is not, as in the traditional view, to use amino acids for the detoxication of aromatic acids. Rather, the converse is more likely, to use aromatic acids that originate from the diet and gut microbiota to assist in the regulation of body stores of amino acids, such as glycine, glutamate, and, in certain invertebrates, arginine, that are key neurotransmitters in the central nervous system (CNS). As such, the amino acid conjugations are not so much detoxication reactions, rather they are homeostatic and neuroregulatory processes. Experimental data have been culled in support of this hypothesis from a broad range of scientific and clinical literature. Such data include the low detoxication value of amino acid conjugations and the Janus nature of certain amino acids that are both neurotransmitters and apparent conjugating agents. Amino acid scavenging mechanisms in blood deplete brain amino acids. Amino acids glutamate and glycine when trafficked from brain are metabolized to conjugates of aromatic acids in hepatic mitochondria and then irreversibly excreted into urine. This process is used clinically to deplete excess nitrogen in cases of urea cycle enzymopathies through excretion of glycine or glutamine as their aromatic acid conjugates. Untoward effects of high-dose phenylacetic acid surround CNS toxicity. There appears to be a relationship between extent of glycine scavenging by benzoic acid and psychomotor function. Glycine and glutamine scavenging by conjugation with aromatic acids may have important psychosomatic consequences that link diet to health, wellbeing, and disease.

Multimodal augmented reality system for surgical microscopy

Image-guided, computer-assisted neurosurgery has emerged to improve localization and targeting, to provide a better anatomic definition of the surgical field, and to decrease invasiveness. Usually, in image-guided surgery, a computer displays the surgical field in a CT/MR environment, using axial, coronal or sagittal views, or even a 3D representation of the patient. Such a system forces the surgeon to look away from the surgical scene to the computer screen. Moreover, this kind of information, being pre-operative imaging, can not be modified during the operation, so it remains valid for guidance in the first stage of the surgical procedure, and mainly for rigid structures like bones. In order to solve the two constraints mentioned before, we are developing an ultrasoundguided surgical microscope. Such a system takes the advantage that surgical microscopy and ultrasound systems are already used in neurosurgery, so it does not add more complexity to the surgical procedure. We have integrated an optical tracking device in the microscope and an augmented reality overlay system with which we avoid the need to look away from the scene, providing correctly aligned surgical images with sub-millimeter accuracy. In addition to the standard CT and 3D views, we are able to track an ultrasound probe, and using a previous calibration and registration of the imaging, the image obtained is correctly projected to the overlay system, so the surgeon can always localize the target and verify the effects of the intervention. Several tests of the system have been already performed to evaluate the accuracy, and clinical experiments are currently in progress in order to validate the clinical usefulness of the system.

Pleomorphic adenoma of the parotid: formal parotidectomy or limited surgery?

BACKGROUND Optimal surgery for pleomorphic adenoma of the parotid is controversial. In the present review, we discuss the advantages and disadvantages of the various approaches after addressing the surgical pathology of the parotid pleomorphic adenoma capsule and its influence on surgery. DATA SOURCES PubMed literature searches were performed to identify original studies. CONCLUSIONS Almost all pleomorphic adenomas can be effectively treated by formal parotidectomy, but the procedure is not mandatory. Extracapsular dissection is a minimal margin surgery; therefore, in the hands of a novice or occasional parotid surgeon, it may result in higher rates of recurrence. Partial superficial parotidectomy may be a good compromise. The tumor is removed with a greater cuff of healthy parotid tissue than in extracapsular dissection. This may minimize the recurrence rate. On the other hand, the removal of healthy parotid tissue compared with formal parotidectomy is limited, thus minimizing complications such as facial nerve dysfunction and Frey syndrome.

Cellular Photo Digital Breathalyzer for Monitoring Alcohol Use: A Pilot Study

Background: Monitoring alcohol use is important in numerous situations. Direct ethanol metabolites, such as ethyl glucuronide (EtG), have been shown to be useful tools in detecting alcohol use and documenting abstinence. For very frequent or continuous control of abstinence, they lack practicability. Therefore, devices measuring ethanol itself might be of interest. This pilot study aims at elucidating the usability and accuracy of the cellular photo digital breathalyzer (CPDB) compared to self-reports in a naturalistic setting. Method: 12 social drinkers were included. Subjects used a CPDB 4 times daily, kept diaries of alcohol use and submitted urine for EtG testing over a period of 5 weeks. Results: In total, the 12 subjects reported 84 drinking episodes. 1,609 breath tests were performed and 55 urine EtG tests were collected. Of 84 drinking episodes, CPDB detected 98.8%. The compliance rate for breath testing was 96%. Of the 55 EtG tests submitted, 1 (1.8%) was positive. Conclusions: The data suggest that the CPDB device holds promise in detecting high, moderate, and low alcohol intake. It seems to have advantages compared to biomarkers and other Monitoring devices. The preference for CPDB by the participants might explain the high compliance. Further studies including comparison with biomarkers and transdermal devices are needed.

The Draft Assembly of the Radically Organized Stylonychia lemnae Macronuclear Genome.

Stylonychia lemnae is a classical model single-celled eukaryote, and a quintessential ciliate typified by dimorphic nuclei: A small, germline micronucleus and a massive, vegetative macronucleus. The genome within Stylonychia's macronucleus has a very unusual architecture, comprised variably and highly amplified "nanochromosomes," each usually encoding a single gene with a minimal amount of surrounding noncoding DNA. As only a tiny fraction of the Stylonychia genes has been sequenced, and to promote research using this organism, we sequenced its macronuclear genome. We report the analysis of the 50.2-Mb draft S. lemnae macronuclear genome assembly, containing in excess of 16,000 complete nanochromosomes, assembled as less than 20,000 contigs. We found considerable conservation of fundamental genomic properties between S. lemnae and its close relative, Oxytricha trifallax, including nanochromosomal gene synteny, alternative fragmentation, and copy number. Protein domain searches in Stylonychia revealed two new telomere-binding protein homologs and the presence of linker histones. Among the diverse histone variants of S. lemnae and O. trifallax, we found divergent, coexpressed variants corresponding to four of the five core nucleosomal proteins (H1.2, H2A.6, H2B.4, and H3.7) suggesting that these ciliates may possess specialized nucleosomes involved in genome processing during nuclear differentiation. The assembly of the S. lemnae macronuclear genome demonstrates that largely complete, well-assembled highly fragmented genomes of similar size and complexity may be produced from one library and lane of Illumina HiSeq 2000 shotgun sequencing. The provision of the S. lemnae macronuclear genome sets the stage for future detailed experimental studies of chromatin-mediated, RNA-guided developmental genome rearrangements.

SALSA: a tool to estimate the stray light contamination for low-Earth orbit observatories

Stray light contamination reduces considerably the precision of photometric of faint stars for low altitude spaceborne observatories. When measuring faint objects, the necessity of coping with stray light contamination arises in order to avoid systematic impacts on low signal-to-noise images. Stray light contamination can be represented by a flat offset in CCD data. Mitigation techniques begin by a comprehensive study during the design phase, followed by the use of target pointing optimisation and post-processing methods. We present a code that aims at simulating the stray-light contamination in low-Earth orbit coming from reflexion of solar light by the Earth. StrAy Light SimulAtor (SALSA) is a tool intended to be used at an early stage as a tool to evaluate the effective visible region in the sky and, therefore to optimise the observation sequence. SALSA can compute Earth stray light contamination for significant periods of time allowing missionwide parameters to be optimised (e.g. impose constraints on the point source transmission function (PST) and/or on the altitude of the satellite). It can also be used to study the behaviour of the stray light at different seasons or latitudes. Given the position of the satellite with respect to the Earth and the Sun, SALSA computes the stray light at the entrance of the telescope following a geometrical technique. After characterising the illuminated region of the Earth, the portion of illuminated Earth that affects the satellite is calculated. Then, the flux of reflected solar photons is evaluated at the entrance of the telescope. Using the PST of the instrument, the final stray light contamination at the detector is calculated. The analysis tools include time series analysis of the contamination, evaluation of the sky coverage and an objects visibility predictor. Effects of the South Atlantic Anomaly and of any shutdown periods of the instrument can be added. Several designs or mission concepts can be easily tested and compared. The code is not thought as a stand-alone mission designer. Its mandatory inputs are a time series describing the trajectory of the satellite and the characteristics of the instrument. This software suite has been applied to the design and analysis of CHEOPS (CHaracterizing ExOPlanet Satellite). This mission requires very high precision photometry to detect very shallow transits of exoplanets. Different altitudes and characteristics of the detector have been studied in order to find the best parameters, that reduce the effect of contamination. © (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Climate-mediated movement of an avian hybrid zone

The interaction between sibling species that share a zone of contact is a multifaceted relationship affected by climate change [ 1, 2 ]. Between sibling species, interactions may occur at whole-organism (direct or indirect competition) or genomic (hybridization and introgression) levels [ 3–5 ]. Tracking hybrid zone movements can provide insights about influences of environmental change on species interactions [ 1 ]. Here, we explore the extent and mechanism of movement of the contact zone between black-capped chickadees (Poecile atricapillus) and Carolina chickadees (Poecile carolinensis) at whole-organism and genomic levels. We find strong evidence that winter temperatures limit the northern extent of P. carolinensis by demonstrating a current-day association between the range limit of this species and minimum winter temperatures. We further show that this temperature limitation has been consistent over time because we are able to accurately hindcast the previous northern range limit under earlier climate conditions. Using genomic data, we confirm northward movement of this contact zone over the past decade and highlight temporally consistent differential—but limited—geographic introgression of alleles. Our results provide an informative example of the influence of climate change on a contact zone between sibling species.

Efficacy and safety of a novel bioabsorbable polymer-coated, everolimus-eluting coronary stent: the EVOLVE II Randomized Trial.

BACKGROUND Drug eluting stents with durable polymers may be associated with hypersensitivity, delayed healing, and incomplete endothelialization, which may contribute to late/very late stent thrombosis and the need for prolonged dual antiplatelet therapy. Bioabsorbable polymers may facilitate stent healing, thus enhancing clinical safety. The SYNERGY stent is a thin-strut, platinum chromium metal alloy platform with an ultrathin bioabsorbable Poly(D,L-lactide-co-glycolide) abluminal everolimus-eluting polymer. We performed a multicenter, randomized controlled trial for regulatory approval to determine noninferiority of the SYNERGY stent to the durable polymer PROMUS Element Plus everolimus-eluting stent. METHODS AND RESULTS Patients (n=1684) scheduled to undergo percutaneous coronary intervention for non-ST-segment-elevation acute coronary syndrome or stable coronary artery disease were randomized to receive either the SYNERGY stent or the PROMUS Element Plus stent. The primary end point of 12-month target lesion failure was observed in 6.7% of SYNERGY and 6.5% PROMUS Element Plus treated subjects by intention-to-treat (P=0.83 for difference; P=0.0005 for noninferiority), and 6.4% in both the groups by per-protocol analysis (P=0.0003 for noninferiority). Clinically indicated revascularization of the target lesion or definite/probable stent thrombosis were observed in 2.6% versus 1.7% (P=0.21) and 0.4% versus 0.6% (P=0.50) of SYNERGY versus PROMUS Element Plus-treated subjects, respectively. CONCLUSIONS In this randomized trial, the SYNERGY bioabsorbable polymer everolimus-eluting stent was noninferior to the PROMUS Element Plus everolimus-eluting stent with respect to 1-year target lesion failure. These data support the relative safety and efficacy of SYNERGY in a broad range of patients undergoing percutaneous coronary intervention. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01665053.

Cervical spinal locking plate in combination with cortical ring allograft for a one level fusion in dogs with cervical spondylotic myelopathy.

OBJECTIVE To evaluate use of a surgical technique commonly used in humans for treatment of cervical spondylotic myelopathy (CSM) in dogs. DESIGN Prospective case series. ANIMALS Dogs with CSM (n=10). METHODS Dogs weighing >30 kg that had CSM at 1 vertebral articulation were eligible for inclusion. Dogs had vertebral column distraction/fusion performed using a cortical ring allograft, cancellous autograft, and a spinal locking plate. Dogs were evaluated temporally by repeat neurological examinations and by client perception of postsurgical outcome, determined by telephone interview. RESULTS Nine dogs survived the immediate postoperative period. Seven of 8 dogs had moderate to complete improvement without recurrence (mean follow-up, 2.48 years). The most common postsurgical complications were screw loosening (n=4) and plate shifting (2), neither of which required surgical revision. One dog had pseudoarthrosis that may have negatively impacted outcome. CONCLUSION Treatment of single level CSM in dogs with ring allograft and a spinal locking plate system may lead to successful outcomes. The major problems encountered with included cost of the implants and adjusting the system designed for humans to fit the vertebral column of a dog. CLINICAL RELEVANCE For dogs with CSM at a single level, the use of a spinal locking plate in combination with a cortical ring allograft can be an effective surgical treatment. Costs of the implants as well as anatomic differences in dogs make this type of surgery less appealing.

Neurologic complications after melarsomine dihydrochloride treatment for Dirofilaria immitis in three dogs.

Melarsomine dihydrochloride is highly effective against both sexes of adult and L5 Dirofilaria immitis. Common adverse reactions include injection site irritation and reluctance to move. Neurologic complications associated with i.m. injection of melarsomine dihydrochloride for treatment of heartworm disease in 3 dogs are described. Different degrees of neurologic complications have been identified; the pathophysiologic features are unknown. It is speculated that the compound migrates out of the injection site via fascial planes and causes an ascending inflammation along nerve roots. The resulting extradural cord compression secondary to extensive inflammation and necrosis of epidural fat could induce a variety of neurologic deficits. Alternatively, inappropriate injection technique may result in direct contact of melarsomine with neural tissue. A heightened awareness of proper injection technique might prevent the development of most neurologic complications.

First Annual IMACS Report: A global International Society for Heart and Lung Transplantation Registry for Mechanical Circulatory Support

The first annual report of the International Society for Heart and Lung Transplantation (ISHLT) Mechanically Assisted Circulatory Support (IMACS) registry provides global data on 5,942 patients from 31 countries. This initial report focuses on patient demographics, survival, device types, adverse events, competing outcomes, and a risk factor analysis.