Surface Of Ventricle Research Articles

Topographic Classification of the Thalamus Surfaces Related to Microneurosurgery: A White Matter Fiber Microdissection Study

To describe the topographic anatomy of surgically accessible surfaces of the human thalamus as a guide to surgical exploration of this sensitive area. Using the operating microscope, we applied the fiber microdissection technique to study 10 brain specimens. Step-by-step dissections in superior-inferior, medial-lateral, and posterior-anterior directions were conducted to expose the surfaces and nuclei of the thalamus and to investigate the relevant anatomic relationships and visible connections. There were 4 distinct free surfaces of the thalamus identified: lateral ventricle surface, velar surface, cisternal surface, and third ventricle surface. Each is described with reference to recognizable anatomic landmarks and to the underlying thalamic nuclei. The neural structures most commonly encountered during the surgical approach to each individual surface are highlighted and described. Observations from this study supplement current knowledge, advancing the capabilities to define the exact topographic location of thalamic lesions. This improved understanding of anatomy is valuable when designing the most appropriate and least traumatic surgical approach to thalamic lesions. These proposed surface divisions, based on recognizable anatomic landmarks, can provide more reliable surgical orientation.

A Secure and High-Fidelity Live Animal Model for Off-Pump Coronary Bypass Surgery Training

Existing simulators for off-pump coronary artery (CA) bypass grafting training are unable to provide cardiac surgery residents all necessary skills they need entering the operation room. In this study, we introduced a secure and high-fidelity live animal model to supplement the in vitro simulators for off-pump CA bypass grafting training. The left internal thoracic artery (ITA) of 3 Chinese miniature pigs was grafted to the left anterior descending CA using an end-to-side anastomosis. The free segment of the ITA was fixed on the ventricle surface, making it a simulative CA beating in synchrony with the heart. A total of 6 to 8 training anastomoses were made on each ITA. Animal Experiment Center in Fuwai Hospital. In total, 19 resident surgeons with at least 3 years of cardiac surgery work experience were trained using the new model. Their performances were recorded and reviewed. Simulative coronary arteries were successfully constructed in all 3 animals with no adverse event observed. A total of 19 anastomoses were then completed, 1 pig of 7 anastomoses and the other 2 animals of 6 anastomoses. Time consumption for the anastomosis was 782 ± 107 seconds. Anastomotic leakage was observed in 10/19 procedures. The most frequency site (7/10) was at the toe of the anastomosis. Further, the most common cause was uneven spacing or small margin of the stitches or both. Emergencies occurred during the training process included hypotension (7 procedures), tachyarrhythmia (4 procedures), and low blood oxygen saturation (1 procedure). This study demonstrated the safety and feasibility of our new live pig model in training resident surgeons. The simulative arteries can be easily accomplished and were long enough to place at least 6 anastomoses. Both on lumen diameter and motion status, they were proven to be a good substitution of the CA.

STGP: Spatio-temporal Gaussian process models for longitudinal neuroimaging data

Longitudinal neuroimaging data plays an important role in mapping the neural developmental profile of major neuropsychiatric and neurodegenerative disorders and normal brain. The development of such developmental maps is critical for the prevention, diagnosis, and treatment of many brain-related diseases. The aim of this paper is to develop a spatio-temporal Gaussian process (STGP) framework to accurately delineate the developmental trajectories of brain structure and function, while achieving better prediction by explicitly incorporating the spatial and temporal features of longitudinal neuroimaging data. Our STGP integrates a functional principal component model (FPCA) and a partition parametric space–time covariance model to capture the medium-to-large and small-to-medium spatio-temporal dependence structures, respectively. We develop a three-stage efficient estimation procedure as well as a predictive method based on a kriging technique. Two key novelties of STGP are that it can efficiently use a small number of parameters to capture complex non-stationary and non-separable spatio-temporal dependence structures and that it can accurately predict spatio-temporal changes. We illustrate STGP using simulated data sets and two real data analyses including longitudinal positron emission tomography data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) and longitudinal lateral ventricle surface data from a longitudinal study of early brain development.

Characterization of multiciliated ependymal cells that emerge in the neurogenic niche of the aged zebrafish brain.

In mammals, ventricular walls of the developing brain maintain a neurogenic niche, in which radial glial cells act as neural stem cells (NSCs) and generate new neurons in the embryo. In the adult brain, the neurogenic niche is maintained in the ventricular-subventricular zone (V-SVZ) of the lateral wall of lateral ventricles and the hippocampal dentate gyrus. In the neonatal V-SVZ, radial glial cells transform into astrocytic postnatal NSCs and multiciliated ependymal cells. On the other hand, in zebrafish, radial glial cells continue to cover the surface of the adult telencephalic ventricle and maintain a higher neurogenic potential in the adult brain. However, the cell composition of the neurogenic niche of the aged zebrafish brain has not been investigated. Here we show that multiciliated ependymal cells emerge in the neurogenic niche of the aged zebrafish telencephalon. These multiciliated cells appear predominantly in the dorsal part of the ventral telencephalic ventricular zone, which also contains clusters of migrating new neurons. Scanning electron microscopy and live imaging analyses indicated that these multiple cilia beat coordinately and generate constant fluid flow within the ventral telencephalic ventricle. Analysis of the cell composition by transmission electron microscopy revealed that the neurogenic niche in the aged zebrafish contains different types of cells, with ultrastructures similar to those of ependymal cells, transit-amplifying cells, and migrating new neurons in postnatal mice. These data suggest that the transformation capacity of radial glial cells is conserved but that its timing is different between fish and mice. J. Comp. Neurol. 524:2982-2992, 2016. © 2016 Wiley Periodicals, Inc.

Fully automated tracking of cardiac structures using radiopaque markers and high-frequency videofluoroscopy in an in vivo ovine model: from three-dimensional marker coordinates to quantitative analyses.

PurposeRecently, algorithms were developed to track radiopaque markers in the heart fully automated. However, the methodology did not allow to assign the exact anatomical location to each marker. In this case study we describe the steps from the generation of three-dimensional marker coordinates to quantitative data analyses in an in vivo ovine model.MethodsIn one adult sheep, twenty silver balls were sutured to the right side of the heart: 10 to the tricuspid annulus, one to the anterior tricuspid leaflet and nine to the epicardial surface of the right ventricle. In addition, 13 cylindrical tantalum markers were implanted into the left ventricle. Data were acquired with a biplanar X-ray acquisition system (Neurostar R, Siemens AG, 500 Hz). Radiopaque marker coordinates were determined fully automated using novel tracking algorithms.ResultsThe anatomical marker locations were identified using a 3-dimensional model of a single frame containing all tracked markers. First, cylindrical markers were manually separated from spherical markers, thus allowing to distinguish right from left heart markers. The fast moving leaflet marker was identified by using video loops constructed of all recorded frames. Rotation of the 3-dimensional model allowed the identification of the precise anatomical position for each marker. Data sets were then analyzed quantitatively using customized software.ConclusionsThe method presented in this case study allowed quantitative data analyses of radiopaque cardiac markers that were tracked fully automated with high temporal resolution. However, marker identification still requires substantial manual work. Future improvements including the implication of marker identification algorithms and data analysis software could allow almost real-time quantitative analyses of distinct cardiac structures with high temporal and spatial resolution.

High-quality digital 3D reconstruction of the terminal pathway of a heart stab wound

High-quality digital 3D reconstructions of microscopic findings have been involved in anatomical and histopathological research, but their potentialities in forensic pathology may also be of particular interest. We here present the use of such methods to furtherly analyse a heart stab wound in a suicidal case. External examination revealed multiple incised wounds on the wrists, three stab wounds at the neck and a single stab wound on the chest. At autopsy, injuries to the neck and wrists were superficial whereas the thoracic stab wound penetrated the chest wall and pericardium. Heart examination showed an 8-mm-long stab wound on the anterior surface of the left ventricle. Heart sectioning and inspection of the correspondent internal aspect of the left ventricle did not show a macroscopic injury, but the irregularity of the trabeculae carneae did not permit to exclude a microscopic pathway. Thus, the heart wall including the stab wound was paraffin-embedded and subjected to complete sectioning for microscopic analysis along all the wound extension. Every 10th section was stained with haematoxylin-eosin and was acquired by using a Leica DMR microscope and a high resolution digital camera. The three-dimensional aspect of the lesion was reconstructed with a software system for 3D computer graphics. Microscopic examination and 3D reconstruction demonstrated that the lesion extended to the internal surface of the ventricle wall, although for a very limited extension. 3D reconstruction also showed a certain curvilinear pattern of the lesion in the myocardium, consistent with myocardial contraction at the moment of injury and consequent vitality of the lesion. Moreover, 3D reconstruction permitted to obtain the dimensions of the intra-myocardial injury (corrected for shrinkage and evaluated in the context of muscle contraction), also permitting to furtherly confirm the identification of the knife involved. In conclusion, the present case is indicative of how complete microscopic sectioning and 3D reconstruction may add further information about characteristics of injuries of forensic interest.

Subendocardial hemorrhages in a case of extrapercardial cardiac tamponade: A possible mechanism of appearance

Subendocardial hemorrhages are grossly visible bleedings in the inner surface of the left ventricle, the interventricular septum, and the opposing papillary muscles and adjacent columnae carneae of the free wall of the ventricle. These are commonly seen in sudden profound hypotension either from severe blood loss from “shock” in the widest sense and, even more often, in combination with brain injuries. We present a case of a 38-year-old man, injured as a car driver in a frontal collision, who died c. 45 minutes after the accident. The autopsy revealed severe chest trauma, including multiple right-sided direct rib fractures with the torn parietal pleura and right-sided pneumothorax, several right lung ruptures, and a rupture of one of the lobar bronchi with pneumomediastinum, and prominent subcutaneous emphysema of the trunk, shoulders, neck and face. The patchy subendocardial hemorrhage of the left ventricle was observed. The cause of death is attributed to severe blunt force chest trauma. We postulate pneumomediastinum leading to extrapericardial tamponade as the underlying mechanism of this subendocardial hemorrhage.

Abstract 15550: Impact of PET Imaging to Visualize Activated Macrophages in Immune Rejection of Allogenic iPS Derived Cardiac Myocytes in Mice

Introduction: Transplantation of allogeneic cells inevitably induce activated macrophage-related host immune response, which would limit therapeutic effects. Importantly, monitoring magnitude of the immune response is poorly established in the allogeneic cell transplantation therapy for the heart. Hypothesis: In this study, we hypothesized that [18F]-DPA-714-PET imaging may visualize activated macrophages accumulated to the host heart after transplantation of allogeneic induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CM). Methods: iPSC-CM cell-sheets of C57BL/6 mice origin were generated by the thermoresponsive dish and transplanted over the surface of the left ventricle (LV) of C57BL/6 mice as a syngeneic cell-transplant model (Group sTx), or Balb/c mice as an allogeneic one (Group aTx). The mice were examined by [18F]-DPA-714-PET to assess maximum standardized uptake value (SUVmax) ratio (A/S ratio) calculated by SUVmax in the anterior and septal wall of the LV. In addition, expression of factors associated with immune rejection was assessed by RT-PCR and the significance of immune rejection was evaluated by Immunochemical staining of CD3 or CD68 positive cell. Results: A/S ratio was comparable in all groups at 1 day (aTx: 1.19±0.05, sTx: 1.16±0.03, sham: 1.20±0.03, p=0.34), though higher in the aTx group than the other groups at 7 day (aTx: 1.38±0.03, p<0.01, sTx: 1.18±0.04, sham: 1.25±0.09) after the cell transplantation. In addition, the expression of IL-2 and MCP-1 of the heart tissue were higher in the aTx group than the other groups at 7 day (aTx: 31.4±3.8, p<0.01, sTx: 1.5±1.2, sham: 2.3±0.9 and aTx: 30.8±12.7, p<0.01, sTx: 4.0±3.4, sham: 5.5±2.0). Furthermore, in the immunochemical histology, the percentages of CD3 and CD68 positive cells were also higher in the aTx group than the other groups at 7day. Conclusions: Accumulation of activated macrophages were identified in the LV surface more intensely after the allogeneic iPSC-CM transplantation than the syngeneic or sham one by the [18F]-DPA-714-PET imaging, warranting that PET imaging may be applicable in clinical setting of the allogeneic cell transplantation therapy to monitor magnitude of host immune response.

Innervation of the rabbit cardiac ventricles.

The rabbit is widely used in experimental cardiac physiology, but the neuroanatomy of the rabbit heart remains insufficiently examined. This study aimed to ascertain the architecture of the intrinsic nerve plexus in the walls and septum of rabbit cardiac ventricles. In 51 rabbit hearts, a combined approach involving: (i) histochemical acetylcholinesterase staining of intrinsic neural structures in total cardiac ventricles; (ii) immunofluorescent labelling of intrinsic nerves, nerve fibres (NFs) and neuronal somata (NS); and (iii) transmission electron microscopy of intrinsic ventricular nerves and NFs was used. Mediastinal nerves access the ventral and lateral surfaces of both ventricles at a restricted site between the root of the ascending aorta and the pulmonary trunk. The dorsal surface of both ventricles is supplied by several epicardial nerves extending from the left dorsal ganglionated nerve subplexus on the dorsal left atrium. Ventral accessing nerves are thicker and more numerous than dorsal nerves. Intrinsic ventricular NS are rare on the conus arteriosus and the root of the pulmonary trunk. The number of ventricular NS ranged from 11 to 220 per heart. Four chemical phenotypes of NS within ventricular ganglia were identified, i.e. ganglionic cells positive for choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS), and biphenotypic, i.e. positive for both ChAT/nNOS and for ChAT/tyrosine hydroxylase. Clusters of small intensely fluorescent cells are distributed within or close to ganglia on the root of the pulmonary trunk, but not on the conus arteriosus. The largest and most numerous intrinsic nerves proceed within the epicardium. Scarce nerves were found near myocardial blood vessels, but the myocardium contained only a scarce meshwork of NFs. In the endocardium, large numbers of thin nerves and NFs proceed along the bundle of His and both its branches up to the apex of the ventricles. The endocardial meshwork of fine NFs was approximately eight times denser than the myocardial meshwork. Adrenergic NFs predominate considerably in all layers of the ventricular walls and septum, whereas NFs of other neurochemical phenotypes were in the minority and their amount differed between the epicardium, myocardium and endocardium. The densities of NFs positive for nNOS and ChAT were similar in the epicardium and endocardium, but NFs positive for nNOS in the myocardium were eight times more abundant than NFs positive for ChAT. Potentially sensory NFs positive for both calcitonin gene-related peptide and substance P were sparse in the myocardial layer, but numerous in epicardial nerves and particularly abundant within the endocardium. Electron microscopic observations demonstrate that intrinsic ventricular nerves have a distinctive morphology, which may be attributed to remodelling of the peripheral nerves after their access into the ventricular wall. In conclusion, the rabbit ventricles display complex structural organization of intrinsic ventricular nerves, NFs and ganglionic cells. The results provide a basic anatomical background for further functional analysis of the intrinsic nervous system in the cardiac ventricles.

Design and In Vivo Test of a Batteryless and Fully Wireless Implantable Asynchronous Pacing System.

This technology uses radio frequency (RF) energy to power the implanted electrode in the heart. An implantable electrode antenna was designed for 1.2 GHz; then, it was tested in vitro and, subsequently, integrated with the rectifier and pacing circuit to make a complete electrode. The prototype implanted electrode was tested in vivo in an ovine subject, implanting it on the epicardial surface of the left ventricle. The RF energy, however, was transmitted to the implanted electrode using a horn antenna positioned 25 cm above the thorax of the sheep. It was demonstrated that a small implanted electrode can capture and harvest enough safe recommended RF energy to achieve pacing. Electrocardiogram signals were recorded during the experiments, which demonstrated asynchronous pacing achieved at three different rates. These results show that the proposed method has a great potential to be used for stimulating the heart and provides pacing, without requiring any leads or batteries. It hence has the advantage of potentially lasting indefinitely and may never require replacement during the life of the patient. The proposed method brings forward transformational possibilities in wireless cardiac pacing, and also in powering up the implantable devices.

Particulate accumulations in the vital organs of wild Brevoortia patronus from the northern Gulf of Mexico after the Deepwater Horizon oil spill.

Histopathologic lesions were observed in the commercially important filter-feeding fish, Brevoortia patronus (Gulf menhaden), along the Louisiana Gulf Coast. Menhaden collected from Louisiana waters in 2011 and 2012, 1 and 2 years following the Deepwater Horizon oil spill, showed varying severities of gill lesions as well as an unusual accumulation of black particulates visible at necropsy in the heart and stomach vasculature. The PAH derived particulates were typically 1-4 µm in diameter, but larger aggregates were observed in the coronary vessels on the ventricle surfaces and their location and size was confirmed by light microscopy. Composited particulate composition was consistent with weathered petrogenic polycyclic aromatic hydrocarbon (PAH) mixtures based on GC-MS analysis. Particulates were present in 63 and 80% of fish hearts and 70 and 89% of stomach muscularis collected in 2011 and 2012, respectively. Tissue embedded particulates can lead to localized cellular damage from bioavailable compounds, as well as chronic effects from occlusion of sensitive tissues' blood flow. The PAH derived particulates appeared to act as emboli in small capillaries, and could associated with localized inflammation, focal necrosis and inappropriate collagen and fibroblast tissue repair. We believe large volume filter feeding teleosts, such as menhaden (up to 3 million gallons per year/fish) with high lipid content, have a higher exposure risk and greater potential for toxicity from toxic particulates than other higher trophic level finfish. Suspended PAH derived particulates following an oil spill therefore, should be considered when assessing long-term ecological impacts and not be limited to physical contact (coating) or water soluble fractions for assessing toxicity (gill and neurologic).

Papillary fibroelastoma – A masquerade for LV tumour

Primary cardiac tumors are rare, with a reported frequency of 0.02%.Cardiac papillary fibroelastoma (CPF) is a benign cardiac tumor with potential for causing life threatening embolic events, the third most common primary tumor of the heart and most commonly affects cardiac valves.All symptomatic patients require surgical intervention, Even asymptomatic left- sided. Papillary fibroelastomas predominates in adults and seen between 4th to 8th decades, incidence more in males. Most cases are acquired, with the etiology is unknown.The aortic valve is most frequently involved followed by the mitral valve. Less frequent sites include the following: mitral chordae, right atrial endocardium, and endocardial surface of both ventricles including the papillary muscles and ventricular septum. The left ventricle is the most common nonvalvular site of involvement.We present a case report of a 60 year old female with previous medical history of Hypertensive, non diabetic presented to us with complaints of dyspnoea NYHA grade 2 since 5 days.Echocardiography showed a 3×2cm mass in the left ventricular cavity with no obstruction at the mitral or the aortic valves. Transeosophageal Echocardiography was not confirmatory of the initial diagnosis thus the patient underwent cardiac CT and MRI which ruled out myxoma and pointed the diagnosis to papillary muscle hypertrophy.The diagnosis being in question and the patient being symptomatic, surgical excision of the mass was decided. Post surgical excision histopathological biopsy revealed the diagnosis of Fibroelastoma. We report a case of papillary fibroelastoma in the left ventricle, a masquerade of LV mass.

Editorial: "Thyroid Hormone in Brain and Brain Cells".

Editorial: "Thyroid Hormone in Brain and Brain Cells".

Identification of G Protein-Coupled Receptors (GPCRs) in Primary Cilia and Their Possible Involvement in Body Weight Control.

Primary cilia are sensory organelles that harbor various receptors such as G protein-coupled receptors (GPCRs). We analyzed subcellular localization of 138 non-odorant GPCRs. We transfected GPCR expression vectors into NIH3T3 cells, induced ciliogenesis by serum starvation, and observed subcellular localization of GPCRs by immunofluorescent staining. We found that several GPCRs whose ligands are involved in feeding behavior, including prolactin-releasing hormone receptor (PRLHR), neuropeptide FF receptor 1 (NPFFR1), and neuromedin U receptor 1 (NMUR1), localized to the primary cilia. In addition, we found that a short form of dopamine receptor D2 (DRD2S) is efficiently transported to the primary cilia, while a long form of dopamine receptor D2 (DRD2L) is rarely transported to the primary cilia. Using an anti-Prlhr antibody, we found that Prlhr localized to the cilia on the surface of the third ventricle in the vicinity of the hypothalamic periventricular nucleus. We generated the Npy2r-Cre transgenic mouse line in which Cre-recombinase is expressed under the control of the promoter of Npy2r encoding a ciliary GPCR. By mating Npy2r-Cre mice with Ift80 flox mice, we generated Ift80 conditional knockout (CKO) mice in which Npy2r-positive cilia were diminished in number. We found that Ift80 CKO mice exhibited a body weight increase. Our results suggest that Npy2r-positive cilia are important for body weight control.

Estradiol alters the chemosensitive cardiac afferent reflex in female rats by augmenting sympathoinhibition and attenuating sympathoexcitation.

The chemosensitive cardiac vagal and sympathetic afferent reflexes are implicated in driving pathophysiological changes in sympathetic nerve activity (SNA) in cardiovascular disease states. This study investigated the impact of sex and ovarian hormones on the chemosensitive cardiac afferent reflex. Experiments were performed in anaesthetized, sinoaortic baroreceptor denervated male, female and ovariectomized female (OVX) Wistar rats with either intact cardiac innervation or bilateral vagotomy. To investigate the chemosensitive cardiac afferent reflexes renal SNA, heart rate (HR) and arterial pressure (AP) were recorded before and following application of capsaicin onto the epicardial surface of the left ventricle. Compared to males, ovary-intact females displayed similar cardiac afferent reflex mediated changes in renal SNA albeit with a reduced maximum sympathetic reflex driven increase in renal SNA. In females, ovariectomy significantly attenuated the cardiac vagal afferent reflex mediated inhibition of renal SNA (renal SNA decreased 2 ± 17% in OVX versus -50 ± 4% in ovary-intact females, P < 0.05) and augmented cardiac sympathetic afferent reflex mediated sympathoexcitation (renal SNA increased 91 ± 11% in OVX vs 62 ± 9% in ovary-intact females, P < 0.05) so that overall increases in reflex driven sympathoexcitation were significantly enhanced. Chronic estradiol replacement, but not progesterone replacement, begun at time of ovariectomy restored cardiac afferent reflex responses to be similar as ovary-intact females. Vagal denervation eliminated all group differences. The current findings show ovariectomy in female rats, mimicking menopause in women, results in greater chemosensitive cardiac afferent reflex driven sympathoexcitation and does so, at least partly, via the loss of estradiols actions on the cardiac vagal afferent reflex pathway.

3D Modeling of the Lateral Ventricles and Histological Characterization of Periventricular Tissue in Humans and Mouse.

The ventricular system carries and circulates cerebral spinal fluid (CSF) and facilitates clearance of solutes and toxins from the brain. The functional units of the ventricles are ciliated epithelial cells termed ependymal cells, which line the ventricles and through ciliary action are capable of generating laminar flow of CSF at the ventricle surface. This monolayer of ependymal cells also provides barrier and filtration functions that promote exchange between brain interstitial fluids (ISF) and circulating CSF. Biochemical changes in the brain are thereby reflected in the composition of the CSF and destruction of the ependyma can disrupt the delicate balance of CSF and ISF exchange. In humans there is a strong correlation between lateral ventricle expansion and aging. Age-associated ventriculomegaly can occur even in the absence of dementia or obstruction of CSF flow. The exact cause and progression of ventriculomegaly is often unknown; however, enlarged ventricles can show regional and, often, extensive loss of ependymal cell coverage with ventricle surface astrogliosis and associated periventricular edema replacing the functional ependymal cell monolayer. Using MRI scans together with postmortem human brain tissue, we describe how to prepare, image and compile 3D renderings of lateral ventricle volumes, calculate lateral ventricle volumes, and characterize periventricular tissue through immunohistochemical analysis of en face lateral ventricle wall tissue preparations. Corresponding analyses of mouse brain tissue are also presented supporting the use of mouse models as a means to evaluate changes to the lateral ventricles and periventricular tissue found in human aging and disease. Together, these protocols allow investigations into the cause and effect of ventriculomegaly and highlight techniques to study ventricular system health and its important barrier and filtration functions within the brain.

Cerebral critical closing pressure in hydrocephalus patients undertaking infusion tests

Objectives:Links between cerebrospinal fluid (CSF) compensation and cerebral blood flow (CBF) have been studied in many clinical scenarios. In hydrocephalus, disturbed CSF circulation seems to be a primary problem, having been linked to CBF disturbances, particularly in white matter close to surface of dilated ventricles. We studied possible correlations between cerebral haemodynamic indices using transcranial Doppler (TCD) ultrasonography and CSF compensatory dynamics assessed during infusion tests.Methods:We analysed clinical data from infusion tests performed in 34 patients suspected to suffer from normal pressure hydrocephalus, with signals including intracranial pressure (ICP), arterial blood pressure (ABP) and TCD blood flow velocity (FV). Cerebrospinal fluid compensatory parameters (including elasticity) were calculated according to a hydrodynamic model of the CSF circulation. Critical closing pressure (CrCP) was calculated with the cerebrovascular impedance methodology, while wall tension (WT) was estimated as CrCP-ICP. Closing margin (CM) was expressed as the difference between ABP and CrCP.Results:Intracranial pressure increased during infusion from 6.7 ± 4.6 to 25.0 ± 10.5 mmHg (mean ± SD; P < 0.001), resulting in CrCP rising by 22.9% (P < 0.001) and WT decreasing by 11.3% (P = 0.005). Closing margin showed a tendency to decrease, albeit not significantly (P = 0.070) due to rising ABP (9.1%; P = 0.005). Closing margin at baseline ICP was inversely correlated to brain elasticity (R = (0.358; P = 0.038), while being significantly different from zero for the whole duration of the tests (52.8 ± 22.8 mmHg; P < 0.001). Neither CrCP nor WT was correlated with CSF compensatory parameters.Discussion:Critical closing pressure increases and WT decreases during infusion tests. Closing margin at baseline pressure may act as an indicator of the cerebrospinal compensatory reserve.

LV Segmentation Using Stochastic Resonance and Evolutionary Cellular Automata

High-level noise and low contrast characteristics in medical images continue to present major bottlenecks in their segmentation despite increased imaging modalities. This paper presents a semi-automatic algorithm that utilizes the noise for enhancing the contrast of low contrast input magnetic resonance images followed by a new graph cut method to reconstruct the surface of left ventricle. The main contribution in this work is a new formulation for preventing the conventional cellular automata method to leak into surrounding regions of similar intensity. Instead of segmenting each slice of a subject sequence individually, we empirically select a few slices, segment them, and reconstruct the left ventricular surface. During the course of surface reconstruction, we use level sets to segment the rest of the slices automatically. We have throughly evaluated the method on both York and MICCAI Grand Challenge workshop databases. The average Dice coefficient (in %) is found to be 92.4 ± 1.3 (value indicates the mean and standard deviation) whereas false positive ratio, false negative ratio, and specificity are found to be 0.019, 7.62 × 10-3, and 0.75, respectively. Average Hausdorff distance between segmented contour and ground truth is determined to be 2.94 mm. The encouraging quantitative and qualitative results reflect the potential of the proposed method.

SERCA-2a is involved in the right ventricular function following myocardial infarction in rats

AimsRight ventricular (RV) function is considered an independent predictor of mortality and development of heart failure (HF) in patients with left ventricle dysfunction following myocardial infarction (MI). The functional and molecular mechanisms that may explain the RV dysfunction are still poorly understood. Our study was conducted to investigate RV contractility and the myocardium protein involved in the calcium handling following MI in rats. Main methodsMI was surgically induced in male Wistar rats to create transmural infarctions involving 40–60% of the left ventricle surface. Infarcted rats were divided into two groups: those that presented classical signs of congestive heart failure (HF group) and those that did not (INF group), and compared to control animals (Sham). RV contractility was studied using isometric contraction in isolated strips and isovolumetric pressure in isolated heart. Key findingsInotropic responses in RV strips were preserved in the INF group but were reduced in the HF group (3.75mM Ca2+ treatment: Sham=163±18; INF=148±19; HF=68±11g/g*; *p<0.05; 5×10−5M isoproterenol: Sham=151±15, INF=134±17, HF=52±7g/g*; *p<0.05). An increase in SERCA-2a protein expression in the RV was observed in the INF group but not in the HF group, which could explain the preserved inotropic response in these animals. SignificanceIncreased SERCA-2a protein expression may play a role in the preservation of RV function post-MI. Therefore, therapeutic strategies that attempt to increase SERCA protein expression levels may be useful for the treatment of HF.

Migration of a Steel Wire Leading to Cardiac Tamponade after Esophageal Perforation: A Case Report

Background: Migration of a foreign body to tissues outside the esophagus is rare but potentially lethal condition that requires prompt recognition and management to achieve a favorable outcome. Case report: we report a rare case of cardiac tamponade caused by esophageal perforation after foreign body ingestion in a 48-year-old man. Once the computed tomography (CT) demonstrated a 1.8 cm foreign body penetrating from the esophagus into the pericardium, an urgent surgery was performed. The foreign body, a steel wire, was removed and the abraded surface of left ventricle was repaired. Fortunately, the patient has recovered and is doing well at the time of this writing. Conclusion: The cardiac tamponade caused by esophageal perforation represents a life-threatening emergency, and delay in diagnosis can result in a significant increase in morbidity and mortality. Thus, timely identification and appropriate treatment would have a positive on patient’s outcome.