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Strokes are one of the leading causes of death in the United States. Stroke treatment involves removal or dissolution of the obstruction (usually a clot) in the blocked artery by catheter insertion. A computer simulation to systematically plan such patient‐specific treatments needs a network of about 105 blood vessels including collaterals. The existing computational fluid dynamic (CFD) solvers are not employed for stroke treatment planning as they are incapable of providing solutions for such big arterial trees in a reasonable amount of time. This work presents a novel one‐dimensional mathematical formulation for blood flow modeling in an elastic blood vessel with a centrally placed rigid catheter. The governing equations are first‐order hyperbolic partial differential equations, and the hypergeometric function needs to be computed to obtain the characteristic system of these hyperbolic equations. We employed the Discontinuous Galerkin method to solve the hyperbolic system and validated the implementation by comparing it against a well‐established 3D CFD solver using idealized vessels and a realistic truncated arterial network. The results showed clinically insignificant differences in steady flow cases, with overall variations between 1D and 3D models remaining below 10%. Additionally, the solver accurately captured wave reflection phenomena at domain discontinuities in unsteady cases. A primary advantage of this model over 3D solvers is its ease in obtaining a discretized geometry of complex vasculatures with multiple arterial branches. Thus, the 1D computational model offers good accuracy and applicability in simulating complex vasculatures, demonstrating promising potential for investigating patient‐specific endovascular interventions in strokes. [ABSTRACT FROM AUTHOR]

Continuous non-invasive blood pressure (CNBP) monitoring is of the utmost importance in detecting and managing hypertension, a leading cause of death in the United States. Extensive research has delved into pioneering methods for predicting systolic and diastolic blood pressure values by leveraging pulse arrival time (PAT), the time difference between the proximal and distal signal peaks. The most widely employed pairing involves electrocardiography (ECG) and photoplethysmography (PPG). Possessing similar characteristics in terms of measuring blood flow changes, a recently investigated optical signal known as speckleplethysmography (SPG) showed its stability and high signal-to-noise ratio compared with PPG. Thus, SPG is a potential surrogate to pair with ECG for CNBP estimation. The present study aims to unlock the untapped potential of SPG as a signal for non-invasive blood pressure monitoring based on PAT. To ascertain SPG's capabilities, eight subjects were enrolled in multiple recording sessions. A third-party device was employed for ECG and PPG measurements, while a commercial device served as the reference for arterial blood pressure (ABP). SPG measurements were obtained using a prototype smartphone-based system. Following the completion of three scenarios—sitting, walking, and running—the subjects' signals and ABP were recorded to investigate the predictive capacity of systolic blood pressure. The collected data were processed and prepared for machine learning models, including support vector regression and decision tree regression. The models' effectiveness was evaluated using root-mean-square error and mean absolute percentage error. In most instances, predictions utilizing P A T S P G exhibited comparable or superior performance to P A T P P G (i.e., SPG Rest ± 12.4 mmHg vs. PPG Rest ± 13.7 mmHg for RSME, and SPG 8% vs. PPG 9% for MAPE). Furthermore, incorporating an additional feature, namely the previous SBP value, resulted in reduced prediction errors for both signals in multiple model configurations (i.e., SPG Rest ± 12.4 mmHg to ±3.7 mmHg for RSME, and SPG Rest 8% to 3% for MAPE). These preliminary tests of SPG underscore the remarkable potential of this novel signal in PAT-based blood pressure predictions. Subsequent studies involving a larger cohort of test subjects and advancements in the SPG acquisition system hold promise for further improving the effectiveness of this newly explored signal in blood pressure monitoring. [ABSTRACT FROM AUTHOR]

Hemorrhage is the second leading cause of death in patients under 46 years of age in the United States. Cessation of hemorrhage prevents hemorrhagic shock and tissue hypoxia. Controlling the bleed via direct pressure or tourniquet is often the first line of defense, but long‐term care requires staples, hemostatic agents, or sealants that seal the vessel and restore blood flow. Here, we compare a new photocurable extracellular matrix sealant (pcECM) with low, medium, and high crosslink density formulations to a commercially available fibrin‐based sealant, TISSEEL®. pcECM has potential uses in surgical and remote settings due to room temperature storage conditions and fast preparation time. Here, we determine if pcECM sealant can stop venous hemorrhage in a murine model, adhere to the wound site in vivo throughout the wound‐healing process, and has the mechanical properties necessary for stopping hemorrhage. Adjusting pcECM crosslinking density significantly affected viscosity, swelling, burst strength, tensile strength, and elasticity of the sealant. 3‐Dimensional ultrasound volume segmentations showed pcECM degrades to 17 ± 8% of its initial implant volume by day 28. Initially, local hemodynamic changes were observed, but returned close to baseline levels by day 28. Acute inflammation was observed near the puncture site in pcECM implanted mice, and we observed inflammatory markers at the 14‐day explant for both sealants. pcECM and fibrin sealant successfully sealed the vessel in all cases, and consistently degraded over 14–28 days. pcECM is a durable sealant with tunable mechanical properties and possible uses in hemorrhage control and other surgical procedures. [ABSTRACT FROM AUTHOR]

Valvular heart conditions significantly contribute to the occurrence of cardiovascular disease, affecting around 2–3 million people in the United States. The anatomical characteristics of cardiac muscles and valves can significantly influence blood flow patterns inside the ventricles. Understanding the interaction between the mitral valve and left ventricle structures enables using fluid–structure interaction simulations as a precise and user-friendly approach to investigating outcomes that cannot be captured using experimental approaches. This study aims to develop a 3D-0D computational model to simulate the consequences of extending the anterior mitral leaflet towards the left ventricle in the presence of the thickness of the left ventricular septum and the mitral valve device. The simulations presented in this paper successfully showcased the ability of the model to replicate occlusion occurring at the left ventricular outflow tract and illustrated the impact of this blockage on the flow pattern and pressure gradient. Furthermore, these simulations conducted following anterior mitral leaflet splitting can emphasize the significance of this technique in reducing the obstruction at the left ventricle outflow tract. The computational model presented in this study, combining 3D and 0D elements, provides significant insights into the flow patterns occurring in the left ventricle before and after anterior leaflet splitting. Thus, expanding this model can help explore other cardiac phenomena and investigate potential post-procedural complications. [ABSTRACT FROM AUTHOR]

Introduction: Extracorporeal membrane oxygenation (ECMO) is associated with gastrointestinal haemorrhage (GIH), which may result from coagulopathy, systemic inflammation, reduced gastric perfusion, and arteriovenous malformation from non-pulsatile blood flow. Data are limited regarding the burden of this complication in the United States. Material and methods: We analysed the National Inpatient Sample (NIS) database for the years 2007 to 2011 to identify hospitalisations in which an ECMO procedure was performed. Hospitalizations complicated by GIH in this cohort were then identified by relevant codes. Results: Between 2007 and 2011, ECMO hospitalisations increased from 1869 to 3799 (p < 0.01). The proportion of hospitalisations complicated by GIH increased from 2.12% in 2007 to 7.46% in 2011 (p < 0.01). Gastrointestinal haemorrhage was more common in men (56.7%) and in Caucasians (57.4%). Common comorbidities in this population were renal failure (71%), anaemia (55%), and hypertension (26%). All-cause inpatient mortality showed a numerical but nonsignificant increase from 56.7% to 61.9% (p = 0.49). The average cost of care per hospitalisation with GIH associated with ECMO use increased from $132,420 in 2007 to $215,673 in 2011 (p < 0.01). Conclusions: Gastrointestinal haemorrhage during ECMO hospitalisations occurred in small but significantly increasing proportions. The inpatient mortality rate and costs associated with GIH were substantial and increased significantly during the study period. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to explore how individuals in the United States of America applied BFR/KAATSU devices and administered BFR/KAATSU training. In addition, the study sought to examine safety topics related to BFR/KAATSU training. Methods: The study was completed using survey research. Subjects were recruited through Facebook, email, and word of mouth. The survey was developed, piloted, and finally deployed March 22, 2021-April 21, 2021. Results: In total, 148 consented to the research; 108 completed the survey, and of those 108, 70 indicated current use with BFR/KAATSU equipment. Professions represented included athletic training, personal training, physical therapy, and strength and conditioning. Among those currently using BFR/KAATSU training (n = 70), the following results were found. The most common devices used were inflatable devices (n = 43, 61.4%). Education completed prior to device administration was formal (n = 39, 55.7%) and/or self-directed (n = 37, 52.9%). Barriers were faced by 29 (41.4%) when trying to enact training. Techniques and parameters varied during application. Screening processes were used (n = 50, 71.4%) prior to training. The devices were used to determine restrictive pressure (n = 31, 44.3%), and a supine position was used most when determining initial restrictive pressure (n = 33, 47.1%). For subsequent restrictive pressure measurements, respondents repeated the same method used initially (n = 38, 54.3%). Workload was often defined as the length of time under tension/load (n = 22, 31.4%) and exercise was directly supervised (n = 52, 74.3%). Adverse effects included bruising, lightheadedness, and cramping (n = 15, 21.4%). The devices have also been applied on those with pathology (n = 16, 22.9%). Conclusion: Those using blood flow restriction/KAATSU devices came from several professions and used an assortment of devices for BFR/KAATSU training. Individuals applied devices using a variety of parameters on populations for which efficacy has and has not been well defined. [ABSTRACT FROM AUTHOR]

Each year, within the United States, tens of thousands of individuals are hospitalized for burn-related injuries. The treatment of deep burns often involves skin grafts to accelerate healing and reduce the risk of infection. The grafting procedure results in a physical disruption between the injured and subsequently debrided host site and the skin graft placed on top of that site. Both neural and vascular connections must occur between the host site and the graft for neural modulation of skin blood flow to take place. Furthermore, evaporative cooling from such burn injured areas is effectively absent, leading to greatly impaired thermoregulatory responses in individuals with large portions of their body surface area burned. Hospitalization following a burn injury can last weeks to months, with cardiovascular and metabolic consequences of such injuries having the potential to adversely affect the burn survivor for years postdischarge. With that background, the objectives of this article are to discuss 1) our current understanding of the physiology and associated consequences of skin grafting, 2) the effects of skin grafts on efferent thermoregulatory responses and the associated consequences pertaining to whole body thermoregulation, 3) approaches that may reduce the risk of excessive hyperthermia in burn survivors, 4) the long-term cardiovascular consequences of burn injuries, and 5) the extent to which burn survivors can "normalize" otherwise compromised cardiovascular responses. Our primary objective is to guide the reader toward an understanding that severe burn injuries result in significant physiological consequences that can persist for years after the injury. [ABSTRACT FROM AUTHOR]

Atherosclerosis, hardening of the arteries, originates from small plaques in the arteries; it is a major cause of disability and premature death in the United States and worldwide. In this paper, we study the bifurcation of a highly nonlinear and highly coupled PDE model describing the growth of an arterial plaque in the early stage of atherosclerosis. The model involves LDL and HDL cholesterols, macrophage cells, and foam cells, with the interface separating the plaque and blood flow regions being a free boundary. We establish finite branches of symmetry-breaking stationary solutions which bifurcate from the radially symmetric solution. Since plaques in reality are unlikely to be strictly radially symmetric, our result would be useful to explain the asymmetric shapes of plaques. [ABSTRACT FROM AUTHOR]

Mechanical interactions between flowing and coagulated blood (thrombus) are crucial in dictating the deformation and remodeling of a thrombus after its formation in hemostasis. We propose a fully-Eulerian, three-dimensional, phase-field model of thrombus that is calibrated with existing in vitro experimental data. This phase-field model considers spatial variations in permeability and material properties within a single unified mathematical framework derived from an energy perspective, thereby allowing us to study effects of thrombus microstructure and properties on its deformation and possible release of emboli under different hemodynamic conditions. Moreover, we combine this proposed thrombus model with a particle-based model which simulates the initiation of the thrombus. The volume fraction of a thrombus obtained from the particle simulation is mapped to an input variable in the proposed phase-field thrombus model. The present work is thus the first computational study to integrate the initiation of a thrombus through platelet aggregation with its subsequent viscoelastic responses to various shear flows. This framework can be informed by clinical data and potentially be used to predict the risk of diverse thromboembolic events under physiological and pathological conditions. Author summary: Thromboembolism is associated with detachment of small thrombus pieces from the bulk in the blood vessel. These detached pieces, also known as emboli, travel through the blood flow and may block other vessels downstream, e.g., they may plug the deep veins of the leg, groin or arm, leading to venous thromboembolism (VTE). VTE is a significant cause of morbidity and mortality and it affects more than 900,000 people in the United States and result in approximately 100,000 deaths every year. Mechanical interaction between flowing blood and a thrombus is crucial in determining the deformation of the thrombus and the possibility of releasing emboli. In this study, we develop a phase-field model that is capable of describing the structural properties of a thrombus and its biomechanical properties under different blood flow conditions. Moreover, we combine this thrombus model with a particle-based model which simulates the initiation of the thrombus. This combined framework is the first computational study to simulate the development of a thrombus from platelet aggregation to its subsequent viscoelastic responses to various shear flows. Informed by clinical data, this framework can be used to predict the risk of diverse thromboembolic events under physiological and pathological conditions. [ABSTRACT FROM AUTHOR]

Background: Military aircrews' health status is critical to their mission readiness, as they perform physically and cognitively demanding tasks in nontraditional work environments. Research Objectives: Our objective is to develop a broad operational risk assessment framework and demonstrate its applicability to health risks to aircrews because of airborne chemical exposure, considering stressors such as heat and exertion.Methods: Extrapolation of generic exposure standards to military aviation-specific conditions can include computation of risk-relevant internal dosimetry estimates by incorporating changes in breathing patterns and blood flow distribution because of aspects of the in-flight environment. We provide an example of the effects of exertion on peak blood concentrations of 1,2,4-trimethylbenzene computed using a physiologically based pharmacokinetic model.Results: Existing published collections on the effects of flight-related stressors on breathing patterns and blood flow address only a limited number of stressors. Although data exist that can be used to develop operational exposure limits specific to military aircrew activities, efforts to integrate this information in specific chemical assessments have been limited.Conclusions: Efforts to develop operational exposure limits would benefit from guidance on how to make use of existing assessments and expanded databases of the impact of environmental stressors on adult human physiology. [ABSTRACT FROM AUTHOR]

• A severe hypoxic event follows electrographic seizures and lasts about 1 hour. • Caffeine causes a dose-dependent drop in hippocampal pO 2. • Caffeine and its metabolites prolong the severe postictal hypoxic event. • Caffeine's prolongation of postictal hypoxia is mediated by adenosine 2A receptors. A stroke-like event follows seizures which may be responsible for the postictal state and a contributing factor to the development of seizure-induced brain abnormalities and behavioral dysfunction associated with epilepsy. Caffeine is the world's most popular drug with ∼85% of people in the USA consuming it daily. Thus, persons with epilepsy are likely to have caffeine in their body and brain during seizures. This preclinical study investigated the effects of acute caffeine on local hippocampal tissue oxygenation pre and post seizure. We continuously measured local oxygen levels in the CA1 region of the hippocampus and utilized the electrical kindling model in rats. Rats were acutely administered either caffeine, or one of its metabolites, or agonists and antagonists at adenosine sub-receptor types or ryanodine receptors prior to the elicitation of seizures. Acute caffeine administration caused a significant drop in pre-seizure hippocampal pO 2. Following a seizure, caffeine, as well as two of its metabolites paraxanthine, and theophylline, increased the time below the severe hypoxic threshold (10 mmHg). Likewise, the specific A 2A receptor antagonist, SCH-58261, mimicked caffeine by causing a significant drop in pre-seizure pO 2 and the area and time below the severe hypoxic threshold. Moreover, the A 2A receptor agonist, CGS-21680 was able to prevent the effect of both caffeine and SCH-58261 adding further evidence that caffeine is likely acting through the A 2A receptor. Clinical tracking and investigations are needed to determine the effect of caffeine on postictal symptomology and blood flow in persons with epilepsy. [ABSTRACT FROM AUTHOR]

Direct thrombin inhibitors (DTIs), such as bivalirudin and dabigatran, have maintained steady inpatient and outpatient use as substitutes for heparin and warfarin, respectively, because of their high bioavailability and relatively safe "ontherapy" range. Current clinical methods lack the capacity to directly quantify plasma DTI concentrations across wide ranges. At present, the gold standard is the ecarin clotting time (ECT), where ecarin maximizes thrombin activity and clotting time is evaluated to assess DTIs' anticoagulation capability. This work focused on the development of a microfluidic paper analytic device (mPAD) that can quantify the extent of anticoagulation as well as DTI concentration within a patient's whole blood sample. Capillary action propels a small blood sample to flow through the nitrocellulose paper channels. Digital images of whole blood migration are then captured by our self-coded Raspberry Pi and/or the Samsung Galaxy S8 smartphone camera. Both the flow length and the blue absorbance from the plasma front on the mPAD were measured, allowing simultaneous, dual assays: ecarin clotting test (ECT) and ecarin chromogenic assay (ECA). Statistically significant (p < .05) changes in flow and absorbance were observed within our translational research study. Currently, there are no quantitative, commercially available point-of-care tests for the ECT and ECA within the United States. Both the ECT and ECA assays could be instrumental to differentiate between supratherapeutic and subtherapeutic incidents during bridging anticoagulant therapy and limit the unwarranted use of reversal agents. [ABSTRACT FROM AUTHOR]

Objective: While decreased ocular blood flow is thought to be a possible contributor to glaucoma pathogenesis, it is unclear what role systemic phosphodiesterase inhibitors (PDEi) play. We performed a cross-sectional study of a nationally representative sample of the U.S. population to investigate the relationship between the most commonly used PDEi, sildenafil and theophylline, and self-reported glaucoma. Methods: We used the National Health and Nutrition Examination Survey 2005–2008 cycles for this observational study. 7,042 participants, aged 40 years and over, responded to a survey item on glaucoma status and were included in the analysis. Multivariable logistic regression models were constructed to evaluate the association between at least 1 year of self-reported PDEi use and prevalent glaucoma. Regressions were adjusted for potential confounding variables, including demographics, socioeconomic status, and general health conditions, and accounted for the complex design of the survey. Sample weights were constructed and used to ensure the generalizability of results. Results: 482 respondents self-reported a diagnosis of glaucoma, of which 11 used sildenafil and 20 used theophylline for at least 1 year. Covariates significantly associated with higher odds of glaucoma prevalence in univariable analyses included older age, black race, former smoking status, diabetes, hyperlipidemia, myocardial infarction, and stroke. Conversely, higher education and income were significantly associated with lower odds of glaucoma prevalence. In regression analyses adjusted for demographic and socioeconomic variables, sildenafil (OR = 4.90, CI: 1.24–19.27, p = 0.025) and theophylline (OR = 3.15, CI: 1.46–6.80, p = 0.005) were significantly associated with higher odds of self-reported glaucoma. These associations held after further adjustment with general health behaviors and conditions for both sildenafil and theophylline. Conclusions: Use of sildenafil and theophylline for one or more years was associated with greater prevalence of self-reported glaucoma, a finding which requires further prospective study to assess causality and possible mechanisms of action. [ABSTRACT FROM AUTHOR]

Nearly 21 million components of blood and whole blood and transfused annually in the United States, while on average only 13.6 million units of blood are donated. As the demand for Red Blood Cells (RBCs) continues to increase due to the aging population, this deficit will be more significant. Despite decades of research to develop hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) as RBC substitutes, there are no products approved for clinical use. Lumbricus terrestris erythrocruorin (LtEc) is the large acellular O2 carrying protein complex found in the earthworm Lumbricus terrestris. LtEc is an extremely stable protein complex, resistant to autoxidation, and capable of transporting O2 to tissue when transfused into mammals. These characteristics render LtEc a promising candidate for the development of the next generation HBOCs. LtEc has a short half-life in circulation, limiting its application as a bridge over days, until blood became available. Conjugation with polyethylene glycol (PEG-LtEc) can extend LtEc circulation time. This study explores PEG-LtEc pharmacokinetics and pharmacodynamics. To study PEG-LtEc pharmacokinetics, hamsters instrumented with the dorsal window chamber were subjected to a 40% exchange transfusion with 10 g/dL PEG-LtEc or LtEc and followed for 48 hours. To study the vascular response of PEG-LtEc, hamsters instrumented with the dorsal window chamber received multiple infusions of 10 g/dL PEG-LtEc or LtEc solution to increase plasma LtEc concentration to 0.5, then 1.0, and 1.5 g/dL, while monitoring the animals’ systemic and microcirculatory parameters. Results confirm that PEGylation of LtEc increases its circulation time, extending the half-life to 70 hours, 4 times longer than that of unPEGylated LtEc. However, PEGylation increased the rate of LtEc oxidation in vivo. Vascular analysis verified that PEG-LtEc showed the absence of microvascular vasoconstriction or systemic hypertension. The molecular size of PEG-LtEc did not change the colloid osmotic pressure or blood volume expansion capacity compared to LtEc, due to LtEc’s already large molecular size. Taken together, these results further encourage the development of PEG-LtEc as an O2 carrying therapeutic. [ABSTRACT FROM AUTHOR]

Indocyanine green (ICG) angiography was first approved by the Food and Drug Administration for human use in the 1956. Prior to its use in chorioretinal angiograms, ICG was used to measure blood flow and track cardiac output. It was only in 1969 when two researchers, Kyuga Kogure and Earl Choromokos from the University of Miami, first used ICG to create more accurate angiograms. In the following years, researchers were able to hone the underlying science of this new form of angiography. As time passed and technology advanced, the application of ICG in clinical practice became widespread. Today ICG is used to diagnose and monitor the progression of retinal and choroidal diseases affecting millions of individuals across the globe. ICG utilizes the injection of indocyanine green dye into a patient's bloodstream to visualize abnormalities of the choroid and retina by evaluating choroidal circulation. ICG angiography is useful in the diagnosis and management of occult choroidal neovascularization in age-related macular degeneration and may be used in other inflammatory conditions with central serous chorioretinopathy. ICG angiography offers advanced imaging for improved monitoring and treatment of a wide variety of choroidal and retinal diseases., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Atherosclerosis, the leading death in the United State, is a disease in which a plaque builds up inside the arteries. As the plaque continues to grow, the shear force of the blood flow through the decreasing cross section of the lumen increases. This force may eventually cause rupture of the plaque, resulting in the formation of thrombus, and possibly heart attack. It has long been recognized that the formation of a plaque relates to the cholesterol concentration in the blood. For example, individuals with LDL above 190 mg/dL and HDL below 40 mg/dL are at high risk, while individuals with LDL below 100 mg/dL and HDL above 50 mg/dL are at no risk. In this paper, we developed a mathematical model of the formation of a plaque, which includes the following key variables: LDL and HDL, free radicals and oxidized LDL, MMP and TIMP, cytockines: MCP-1, IFN-γ, IL-12 and PDGF, and cells: macrophages, foam cells, T cells and smooth muscle cells. The model is given by a system of partial differential equations with in evolving plaque. Simulations of the model show how the combination of the concentrations of LDL and HDL in the blood determine whether a plaque will grow or disappear. More precisely, we create a map, showing the risk of plaque development for any pair of values (LDL,HDL). [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Altered carotid blood flow velocities (CFV) have a complex background but the underlying genetic contribution is still unclear. We sought to evaluate the influence of genetics, shared and unshared environmental components on individual differences of CFV. Methods: 193 healthy twin pairs, 126 monozygotic (MZ) and 67 dizygotic (DZ) (mean age 53 ± 14 years) recruited in Italy, in the United States and in Hungary underwent bilateral color-coded Doppler flow assessment of the common carotid artery (CCA) and of the internal carotid artery (ICA) in order to assess the peak systolic (PSV) and end diastolic (EDV) velocities. Means of bilateral CFV values were used in the analysis. Results: Age- and country-adjusted intra-class correlations were higher in monozygotic than in dizygotic pairs for mean PSV of the ICA indicating a heritability of 63%. Unique environmental factors contributed to 37% of ICA PSV. With regards to the mean PSV and EDV of the CCA, and EDV of the ICA, heritability analysis indicated no discernible role for genetic components, while the contributions of shared and unshared environmental factors ranged between 56% and 63%, and between 37% and 44% adjusted for age and country, respectively. Mean ICA/CCA ratio was driven by unique environmental factors (82%) with modest heritability (18%). Conclusions: Our study showed that the heritability of ICA PSV and ICA/CCA ratio is moderate, while the findings do not support heritability of other investigated CFV values. Environmental effects account for a moderate to major portion of the variance. These findings support the value of early ultrasound screening as well as the prevention of modifiable environmental factors in case of altered carotid flow velocities. [Copyright &y& Elsevier]

Stroke is the third leading cause of death in the United States. Reduced cerebral blood flow causes acute damage to the brain due to excitotoxicity, reactive oxygen species (ROS), and ischemia. Currently, the main treatment for stroke is to revive the blood flow by using thrombolytic agents. Reviving blood flow also causes ischemia-reperfusion (I/R) damage. I/R damage results from inflammation and apoptosis and can persist for days to weeks, increasing the infarct size. Drugs can be applied to stroke to intervene in the sub-acute and chronic phases. Chemical, peptide, and genetic therapies have been evaluated to reduce delayed damage to the brain. These drugs have different characteristics, requiring that delivery carriers be developed based on these characteristics. The delivery route is another important factor affecting the efficiency of drug delivery. Various delivery routes have been developed, such as intravenous injection, intranasal administration, and local direct injection to overcome the blood-brain-barrier (BBB). In this review, the delivery carriers and delivery routes for peptide and gene therapies are discussed and examples are provided. Combined with new drugs, drug delivery systems will eventually provide useful treatments for ischemic stroke. [ABSTRACT FROM AUTHOR]

ABSTRACT Up to 75% of women in the US report having experienced hot flashes during the menopausal transition. The purpose of this review is to describe the physiology of hot flashes, and the ways in which hot flashes have been examined by subjective report and by objective measurement. Hot flashes occur because of an activation of the heat dissipation response, possibly triggered by a hypothalamic mechanism within the context of declining estrogen levels. There is cross-population variation in the frequency of self-reported hot flashes, although cross-study comparisons are problematic because of incompatibilities in study design. Diaries are a good way to collect information on the time and severity of hot flashes, and body diagrams allow researchers to study the pattern of heat and sweating. Hot flashes can be objectively measured by increases in heart rate, finger blood flow, respiratory exchange ratio, skin temperature, and core body temperature. Sternal skin conductance is the method most highly correlated with subjective hot flash report. In a laboratory, concordance between subjective report and sternal skin conductance can approach 100%. Ambulatory monitoring allows for the tracking of hot flashes during a woman's daily routine or sleep; however, concordance is much lower with ambulatory, compared to laboratory, monitoring. The study of hot flashes at menopause provides a model for the study of any experience that can be assessed by both self-report and biometric measurement. Am. J. Hum. Biol., 25:573-580, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: Hepatocellular carcinoma (HCC), or liver cancer, is one of the fastest growing cancers in the United States. Current liver ablation methods are thermal based and share limitations resulting from the heat sink effect of blood flow through the highly vascular liver. In this study, we explore the feasibility of using histotripsy for non-invasive liver ablation in the treatment of liver cancer. Histotripsy is a non-thermal ablation method that fractionates soft tissue through the control of acoustic cavitation. Twelve histotripsy lesions ∼1 cm3 were created in the livers of six pigs through an intact abdomen and chest in vivo. Histotripsy pulses of 10 cycles, 500-Hz pulse repetition frequency (PRF), and 14- to 17-MPa estimated in situ peak negative pressure were applied to the liver using a 1-MHz therapy transducer. Treatments were performed through 4–6 cm of overlying tissue, with 30%–50% of the ultrasound pathway covered by the rib cage. Complete fractionation of liver parenchyma was observed, with sharp boundaries after 16.7-min treatments. In addition, two larger volumes of 18 and 60 cm3 were generated within 60 min in two additional pigs. As major vessels and gallbladder have higher mechanical strength and are more resistant to histotripsy, these remained intact while the liver surrounding these structures was completely fractionated. This work shows that histotripsy is capable of non-invasively fractionating liver tissue while preserving critical anatomic structures within the liver. Results suggest histotripsy has potential for the non-invasive ablation of liver tumors. [Copyright &y& Elsevier]

The objective was to determine if proper application of the Stretch, Wrap, and Tuck Tourniquet (SWAT-T) would stop arterial flow and would occur with minimal training. Methods: Fifteen undergraduates watched a 19 second video three times, practiced twice, and applied the tourniquet to volunteers at 10 locations: 3 above the elbow or knee and 2 below. Results: Successful occlusion (60 second Doppler signal elimination) was more frequent than proper stretch (96 versus 75), more frequent on arms than legs (59 versus 37), and achieved before completed application (16 + 8 versus 33 ± 8 seconds; each p < 0.05). Proper stretch (correct alteration of shapes printed on the tourniquet) was more frequent on legs than arms (30 versus 45; p < 0.05). Applications were rated Easy (101), Challenging (37), Difficult (12) with discomfort None (53), Little (62), Moderate (34), Severe (1). The 8 appliers with <70% proper stretch rates received 10 minutes additional training and then retested at mid upper arm, mid-thigh, and below knee (24 applications) for improved proper stretch and occlusion (5 versus 18 and 10 versus 20; p < 0.01). Conclusions: Proper application of the SWAT-T is easy and can stop extremity arterial flow but requires some training for many appliers. [ABSTRACT FROM AUTHOR]

We compared incidence of methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) in the United States and England by using population-based surveillance. The incidence of community-onset MRSA BSI was 6.3-fold higher in the United States than in England, whereas the incidence of hospital-onset MRSA BSI was similar between the 2 countries. [ABSTRACT FROM AUTHOR]

Acute myocardial infarction (Ml) is one of the most frequent causes of death in the United States. The evaluation and treatment of acute Ml in conventional medicine has focused primarily on anatomical and physiological factors that lead to impaired blood flow. Less attention has been paid to metabolic factors that may influence the vulnerability of the myocardium to ischemia and to various Stressors. There is evidence that in some cases inefficient cellular metabolism, rather than the availability of oxygen and other blood-borne nutrients, is an important factor determining whether cardiac pathology will develop. Metabolic dysfunction could result from intracellular deficiencies of magnesium, coenzyme Q10, carnitine, and certain B vitamins, nutrients which play a role in the synthesis of adenosine triphosphate (ATP; the body's main storage form of energy). In addition, increased oxidative stress may contribute to the pathogenesis of both Ml-related myocardial damage and reperfusion injury. Consequently, administration of antioxidants might improve outcomes in patients with acute Ml. Numerous clinical trials have found parenteral administration of magnesium in the early stages of acute Ml can substantially reduce the death rate. In addition, several trials have shown L-carnitine is beneficial in the treatment of acute Ml. Other nutrients, such as vitamin C, vitamin E, and various B vitamins, may also be of value. [ABSTRACT FROM AUTHOR]

Abstract: Coronary artery disease contributes to a third of global deaths, afflicting seventeen million individuals in the United States alone. To understand the role of hemodynamics in coronary artery disease and better predict the outcomes of interventions, computational simulations of blood flow can be used to quantify coronary flow and pressure realistically. In this study, we developed a method that predicts coronary flow and pressure of three-dimensional epicardial coronary arteries by representing the cardiovascular system using a hybrid numerical/analytic closed loop system comprising a three-dimensional model of the aorta, lumped parameter coronary vascular models to represent the coronary vascular networks, three-element Windkessel models of the rest of the systemic circulation and the pulmonary circulation, and lumped parameter models for the left and right sides of the heart. The computed coronary flow and pressure and the aortic flow and pressure waveforms were realistic as compared to literature data. [Copyright &y& Elsevier]

Abstract: The aim of the present paper was to present an overview of the current status of the methods used to predict the magnitude of pharmacokinetic drug–drug interactions (DDIs) which are caused by apparent changes in cytochrome P450 (CYP) activity with an emphasis on a method using in vivo information. In addition, more than a hundred representative CYP substrates, inhibitor and inducer drugs involved in significant pharmacokinetic DDIs were selected from the literature and are listed. Although the magnitude of DDIs has been conventionally predicted based on in vitro experiments, their predictability is restricted occasionally due to several difficulties, including a precise determination of the unbound inhibitor concentrations at the enzyme site and a reliable in vitro measurement of the inhibition constant (K i ). Alternatively, a simple method has been recently proposed for the prediction of the magnitude of DDIs based on information fully available from in vivo clinical studies. The new in vivo-based method would be applicable to the adjustment of dose regimens in actual pharmacotherapy situations although it requires a prior clinical study for the prediction. In this review, theoretical and quantitative relationships between the in vivo- and the in vitro-based prediction methods are considered. One of the interesting outcomes of the consideration is that the K i -normalized dose (dose/in vitro K i ) of larger than approximately 20L (2–200L, when variability is considered) may be a pragmatic index which predicts significant in vivo DDIs. In the last part of the article, the relevance of the inclusion of the in vivo-based method into the process of new drug development is discussed for good prediction of in vivo DDIs. [Copyright &y& Elsevier]

BACKGROUND AND PURPOSE Collaterals may compensate for reduced blood flow in acute ischemic stroke, yet endurance and quality of collateral perfusion may vary. Collateral sustenance of penumbra may falter after initial recruitment, resulting in progressive ischemia and clinical deficits. Delayed collateral failure may extend the time window for revascularization, even after failed intravenous thrombolysis. CASE DESCRIPTION A 76-year-old woman returned to normal from National Institutes of Health Stroke Scale (NIHSS) score of 18 following intravenous thrombolysis, despite persistent occlusion of the left middle cerebral artery. Subsequent deterioration was successfully reversed with mechanical thrombectomy almost 14 hours after symptom onset. CONCLUSIONS Early clinical improvement or deterioration may reflect collateral perfusion, not necessarily recanalization or reocclusion. The definition of collateral failure must incorporate the expected role and endurance of collaterals. Further investigation of collateral pathophysiology may reveal predictive clinical or imaging features and disclose collateral therapeutic approaches to augment revascularization. J Neuroimaging 2010;20:78-82. [ABSTRACT FROM AUTHOR]

Abstract: IRL-1620, a highly selective ETB receptor agonist, is presently in a phase I clinical trial (NCT00613691) in the United States for patients with recurrent or progressive carcinoma. The effect of acute repeated administration of IRL-1620 on the development of tachyphylaxis to changes in blood pressure, heart rate and blood flow (renal and cerebral) has not been studied. The present studies were conducted in urethane anesthetized rats to determine the cardiovascular effects of acute repeated intravenous administration of IRL-1620. In order to determine the tachyphylactic effect, each dose of IRL-1620 was administered at 0, 60, and 120min. It was found that IRL-1620 did not significantly affect heart rate. IRL-1620 produced a transient fall in blood pressure. A fall in mean arterial pressure (MAP) of 35.47% with 1.6μg/kg, 38.87% with 5.0μg/kg and 28.04% with 15.0μg/kg dose of IRL-1620 was observed. Repeated administration of a low dose (1.6μg/kg, i.v.) of IRL-1620 produced a fall in MAP but no tachyphylaxis was observed. However, repeated administration of IRL-1620 (5.0μg/kg, i.v.) produced a fall in MAP of 40.12%, 29.15%, and 21.61% with the first, second and third injections, respectively. IRL-1620 produced a consistent decrease in renal blood flow and increase in cerebral blood flow without any evidence of tachyphylaxis. Pretreatment with ETA antagonist BMS187824 (5mg/kg, i.v.), followed by three doses of 5μg/kg IRL-1620 at 60min intervals eliminated the development of tachyphylaxis to the transient hypotension, confirming the involvement of the ETA receptor in tachyphylactic development. The findings indicate development of tachyphylaxis to IRL-1620 only to the fall in blood pressure when given repeatedly at mid-high doses, while the decrease in renal and increase in cerebral blood flow were not affected with regards to tachyphylactic development. [Copyright &y& Elsevier]

The purpose of this study was to examine the flow velocity pattern of the brachial artery and to determine its relationship to measures of physical function. Subjects from the Louisiana Healthy Aging Study (n = 95; age = 84 +/- 10 years) were evaluated. Brachial artery flow velocities and dimensions were measured using high-resolution ultrasonography. The continuous scale of physical function and performance test (CS-PFP10) was used to assess physical function. This test is based on the performance of 11 activities of daily living. Total CS-PFP10 score was 39.51 +/- 21.21 U. Mean antegrade and retrograde velocities at rest were 14.2 +/- 4.7 and 3.6 +/- 2.2 cm/s, respectively. Ante-/retrograde ratio was 5.5 +/- 4.6. Brachial artery diameter was 4.3 +/- 0.7 mm. Pulse pressure and vascular conductance were 66 +/- 18 mmHg, and 0.9 +/- 0.5 ml/min/mmHg, respectively. Vascular conductance (r = -0.34), ante-/retrograde ratio (r = -0.42) and CS-PFP10 (r = -0.65) were inversely and retrograde velocity (r = 0.40) and pulse pressure (r = 0.36), were directly associated with age. Retrograde velocity was inversely related to vascular conductance (r = -0.27) and CS-PFP10 total score (r = -0.45). A MANOVA revealed that those with the higher CS-PFP10 scores had a lower retrograde velocity (P = 0.0001), but this association was, in part, age-dependent. Among nonagenarians (n = 52), those in the lower tertiles of the CS-PFP10 scores had significantly higher retrograde velocities compared to those in the higher tertiles (P = 0.035). These data indicate an increase in brachial retrograde velocity with age. These hemodynamic changes are related to a decline in physical function. [ABSTRACT FROM AUTHOR]

Transrectal real-time ultrasonography (US) has been developed as a research and practical tool in bovine reproduction. Noninvasive US observations have made it possible to provide real-time and serial analyses of ovarian morphological changes and fetal development and have generated new information on reproductive physiology during the bovine oestrous cycle and pregnancy. This has greatly contributed to an understanding of the real-time dynamics of follicular development. US has also allowed for more accurate diagnosis compared with rectal palpation in reproductive management in cattle. Practical applications of US include early diagnosis of pregnancy, identification of twin fetuses, detection of ovarian and uterine pathologies and determination of fetal sex. In recent years, local blood flow has been analysed in individual ovarian follicles and the corpus luteum (CL) in the cow using colour Doppler US. From these observations, it has been found that (1) the blood supply to follicles is closely related to follicular growth, atresia and ovulation, (2) the blood supply to the CL increases in parallel with its growth, and (3) there is an acute increase in blood flow in the mature CL prior to luteal regression. Colour Doppler US may provide an estimate of the physiological status of follicles and corpora lutea. For example, images of blood flow can be used to assess the thickness of the follicular wall and provide a differential diagnosis of follicular and luteal cysts. Assessment of the area of blood flow in the CL using colour Doppler imaging may offer a useful adjunct in estimating CL function, which could be applied to the diagnosis of non-pregnancy and fetal loss. The number of small follicles which have blood flow at the start of gonadotrophin treatment may be a useful index to predict the superovulatory response. With improvements in portability and cost-effectiveness, the evaluation of ovarian blood flow by colour Doppler US is likely to become widely used as a diagnostic tool for monitoring ovarian function in dairy cattle. [ABSTRACT FROM AUTHOR]

Over 70% of patients initiating chronic hemodialysis in the United States have a tunneled central venous catheter (CVC) for dialysis as their first blood access device. Tunneled CVC have requirements that are unparalleled by other access devices: high blood flow rates at moderate pressure drops without obstruction, minimal trauma to the vein, resistance to occlusion by fibrous sheathing, prevention of infection, avoidance of clotting, biocompatibility, avoidance of lumen collapse and kinking and breaks, resistance to antiseptic agents, placement with minimal trauma, and radiopaque appearance on X-ray. This publication reviews the numerous designs for tunneled CVC and evaluates the advantages and disadvantages of each design. A catheter that self-centers in the superior vena cava (Centros™) is described, along with early clinical results. Current challenges and future directions for tunneled CVC for dialysis are discussed, included means to diminish catheter-related infections, catheter tip clotting, fibrous sheathing, central venous stenosis, and external component bulk. [ABSTRACT FROM AUTHOR]

Approximately 1.6 million patients in the United States are affected by tricuspid valve regurgitation, which occurs when the tricuspid valve does not close properly to prevent backward blood flow into the right atrium. Despite its critical role in proper cardiac function, the tricuspid valve has received limited research attention compared to the mitral and aortic valves on the left side of the heart. As a result, proper valvular function and the pathologies that may cause dysfunction remain poorly understood. To promote further investigations of the biomechanical behavior and response of the tricuspid valve, this work establishes a parameter-based approach that provides a template for tricuspid valve modeling and simulation. The proposed tricuspid valve parameterization presents a comprehensive description of the leaflets and the complex chordae tendineae for capturing the typical three-leaflet structural deformation observed from medical data. This simulation framework develops a practical procedure for modeling tricuspid valves and offers a robust, flexible approach to analyze the performance and effectiveness of various valve configurations using isogeometric analysis. The proposed methods also establish a baseline to examine the tricuspid valve's structural deformation, perform future investigations of native valve configurations under healthy and disease conditions, and optimize prosthetic valve designs. [ABSTRACT FROM AUTHOR]

Rapid reperfusion is the key treatment goal in patients with ST-segment elevation myocardial infarction (STEMI). The American College of Cardiology-American Heart Association (ACC-AHA) 2004 guidelines for the management of STEMI include recommendations for pharmacologic reperfusion with use of fibrinolytic agents. Fibrinolytic agents are the preferred pharmacologic class for the management of STEMI because of their ability to achieve reperfusion and to restore blood flow when administered within 12 hours of symptom onset. Four fibrinolytic agents are approved for the treatment of STEMI in the United States--streptokinase, alteplase, reteplase, and tenecteplase. Several clinical trials have demonstrated the beneficial effects of these therapies in reducing mortality rates in patients with suspected acute myocardial infarction. Alteplase is administered as an intravenous infusion. However, the relatively long half-lives of reteplase and tenecteplase enable bolus administration, which may be more convenient and less time consuming. Reteplase is administered as a double bolus, and dosing does not depend on the patient's weight; tenecteplase is administered as a single bolus, and dosing is weight based. Adherence to the ACC-AHA guidelines, as well as knowledge about the available fibrinolytic agents, is essential for physicians and pharmacists to make informed decisions regarding appropriate pharmacologic reperfusion strategies. [ABSTRACT FROM AUTHOR]

Visualization of volumetric multicomponent data sets is a high-dimensional problem, especially for color data. Medical 3D ultrasound (US) technology has rapidly advanced during the last few decades and scanners can now generate joint 3D scans of tissues (B-mode) and blood flow (power or color Doppler) in real time. Renderings of such data sets have to comprehensively convey both the relevant structures of the tissues that form the context for blood flow, as well as the distribution of blood flow itself. The narrow field of view in US data, which is often used to make real-time imaging possible, complicates volume exploration since only parts of organs are usually visible; that is, clearly defined anatomical landmarks are scarce. In addition, the noisy nature and low signal-to-contrast ratio of US data make effective visualization a challenge, whereby there are currently no convincing solutions for combined US B-mode and color Doppler data rendering. Therefore, displaying 2D slices out of the 3D data is still often the preferred visualization method. We present new combinations of photorealiatic and nonphotorealistic rendering strategies for combined visualization of B-mode and color Doppler data, which are straightforward to implement, flexible, and suited for a wide range of US applications. [ABSTRACT FROM AUTHOR]

The article discusses the contemporary percutaneous treatment of infrapopliteal arterial disease in the U.S. The author explains that the infrapopliteal interventions are rewarding because establishing straight line blood flow to the foot can provide adequate perfusion to heal ischemic ulcers and prevent amputations. The first important treatment option for infrapopliteal arterial disease is percutaneous revascularization.

Official reports relate that, in the US, one patient/month dies as a result of the emergency oxygenator change-out procedure, and the permanent injury of some patients is the result of current oxygenator change-out procedures or oxygenator failures, both in extracorporeal circulation (ECC) and extracorporeal membrane oxygenation (ECMO). The aim of this article is to evaluate a new system and procedure, dedicated to oxygenator change-out, represented by two three-way stopcocks inserted in the ECC line in use. A dedicated back-up oxygenator and circuit can be easily primed and connected to the dedicated connector on the stopcocks, then blood flow is diverted to the new oxygenator without interruption of the ECC. Tests performed showed that oxygenator change-out can be completed by perfusionists in 62.13±11.12 sec. Results obtained show that the new system and procedure allows fast, safe and reproducible oxygenator change-out without interruption of the ECC. [ABSTRACT FROM AUTHOR]

Dietary antioxidants contribute to endogenous photoprotection and are important for the maintenance of skin health. In the present study, 2 groups of women consumed either a high flavanol (326 mg/d) or low flavanol (27 mg/d) cocoa powder dissolved in 100 mL water for 12 wk. Epicatechin (61 mg/d) and catechin (20 mg/d) were the major flavanol monomers in the high flavanol drink, whereas the low flavanol drink contained 6.6 mg epicatechin and 1.6 mg catechin as the daily dose. Photoprotection and indicators of skin condition were assayed before and during the intervention. Following exposure of selected skin areas to 1.25 x minimal erythemal dose (MED) of radiation from a solar simulator, UV-induced erythema was significantly decreased in the high flavanol group, by 15 and 25%, after 6 and 12 wk of treatment, respectively, whereas no change occurred in the low flavanol group. The ingestion of high flavanol cocoa led to increases in blood flow of cutaneous and subcutaneous tissues, and to increases in skin density and skin hydration. Skin thickness was elevated from 1.11 +/- 0.11 mm at wk 0 to 1.24 +/- 0.13 mm at wk 12; transepidermal water loss was diminished from 8.7 +/- 3.7 to 6.3 +/- 2.2 g/(h x m2) within the same time frame. Neither of these variables was affected in the low flavanol cocoa group. Evaluation of the skin surface showed a significant decrease of skin roughness and scaling in the high flavanol cocoa group compared with those at wk 12. Dietary flavanols from cocoa contribute to endogenous photoprotection, improve dermal blood circulation, and affect cosmetically relevant skin surface and hydration variables. [ABSTRACT FROM AUTHOR]

Focuses on guidelines for the determination of brain death in infants and children in the U.S. Epidemiology of brain death; Occurrence of hypothermia in children who are comatose after catastrophic brain injury; Neuroimaging techniques used to document the absence of cerebral blood flow.

Explores whether the temperature dependence of whale blood flow behavior might show adaptation for maintaining peripheral blood flow in these animals. Benefits of such an adaptation for the animal's temperature regulation; Apparent viscosity versus shear rate properties of bowhead whale blood over a range of temperatures known to be present in their tail thermal exchange circulation; Study conducted at the Barrow Arctic Science Consortium facility, Barrow, Alaska, during the spring subsistence whaling season.

Abstract: Adult respiratory distress syndrome (ARDS) has been the major cause of mortality in burn injury. The authors reported the experience of using extracorporeal membrane oxygenation (ECMO) to treat adult burn patient with ARDS. Three patients with burn or electric injury, around 48.9% of body surface area over second-degree burns, developed ARDS after resuscitation. All had positive blood culture and depended on a ventilator more than 5 days before ECMO. Venovenous (VV) ECMO was started at the beginning of severe respiratory failure with an oxygen index of 61.6 ± 15.5 cm H2O/mm Hg (≧40 cm H2O/mm Hg), partial arterial oxygen tension to inspired oxygen fraction (Pao2/Fio2) of 46.1 ± 7.0 mm Hg (≤200 mm Hg), positive end expiratory pressure (PEEP) of 15.7 ± 1.6 cm H2O (≧10 cm H2O), alveolar-arterial difference in oxygen concentration (A-a Do2) of 618.9 ± 19.3 mm Hg (≧300 mm Hg), and lung compliance of 17.3 ± 4.6 ml/cm H2O (≤30 ml/cm H2O). The VV type had to be converted to the newly designed veno-venoarterial (V-VA) ECMO due to the myocardial dysfunction. Two of three patients survived. The duration of ECMO was 160.2 ± 51.1 h. Two patients received debridement of escar during ECMO support and desmopressin infusion, and no increased bleeding or coagulopathy was found. The respiratory parameters were significantly improved after ECMO, especially in the survivors. ECMO is also suitable for ARDS in adult burn injury. [ABSTRACT FROM AUTHOR]

Part I. Examines percutaneous fibrin sheath stripping, a method for catheter salvage in the U.S. Challenges faced by medical personnel in the formation of fibrin sheath material limiting adequate blood flow rates; Types of catheter failures; Proposition of an algorithm for catheter salvage.

Each year over two million hospitalized Americans depend upon the timely availability of the right type of blood products at 6,000 hospital blood banks (HBB's) in the United States. If the right blood products are not available at the HBB when required, then medical complications or postponements of elective surgery can result which translates to extra days of hospitalization and expense. On the other hand, since most blood products may only be administered to a patient of the same blood type within 21 days of collection, overstocking at HBB's leads to low utilization, which increases costs and is wasteful of the scarce blood resource. The Long Island blood distribution system was set up as a prototype of a regional blood center and the hospital blood banks that it services collaborating to preplan regional blood flow. It maximizes blood availability and utilization according to a Programmed Blood Distribution System (PBDS) model and strategy that has been shown to be generally applicable. PBDS schedules blood deliveries according to statistical estimates of the needs of each HBB and monitors actual requirements to adjust deliveries when indicated by control chart techniques. In addition, it provides a daily forecasting of short-term shortages and surpluses for the next several days that results in controlled movement of blood to and from adjoining regions. Finally, the system is able to adjust the regional strategy so that availability is reduced uniformly at all HBB's during periods of seasonal, regional shortages. PBDS has drastically improved utilization and availability of blood on Long Island: wastage has been reduced by 80%, and delivery costs by 64%. This prototype is acting as a model for other regional blood centers in the United States and for other national blood services as a basis for planning and controlling blood flow in a geographic area. It usually replaces preexisting procedures where a regional blood center collects blood based upon gross estimates and reacts to requests for blood by individual HBB's on the basis of experience and on the currently prevailing inventory situation. [ABSTRACT FROM AUTHOR]

The article presents a study on the systemic and ankle blood pressure before and after exercise in patients with arterial insufficiency in the U.S. The study is essential to detect early cases of arteriosclerotic disease. The introduction of various methods for the noninvasive determination of systolic arterial blood pressure provide opportunity for the study of distal pressure and for patients with low blood flow.

Robotic skeletonizing and harvesting of the internal thoracic artery, using the da Vinci surgical system, has a number of advantages over robotic pediculed ITA harvesting. The advantages include greater blood flow, a longer conduit, and less bleeding. The technique is facilitated by use of the EndoWrist spatula cautery and fine tissue forceps (Intuitive Surgical, Inc., Sunnyvale, CA, USA). How the technique is performed is described in this report. [ABSTRACT FROM AUTHOR]

The article discusses the developments of heart surgery in the U.S. Warm Heart Surgery is considered the major accepted methods and techniques for the myocardial infarction protection. It was found out in the experiments conducted at the McGill University that the said surgery has faced several complications including the distention of the heart, blood in the operative field and distribution of the blood flow.

The article reports on the vascular complications in pediatric liver transplantation in the U.S. Arterial thrombosis (HAT) had a major impact on survival after pediatric orthotopic liver transplantation (OLT), both in terms of morbidity and mortality. The frequent vascular complications were related with the portal vein, which is a common observation. Therefore, the HAT-related sclerosing cholangitis is more the rule than the exception even after surgical restoration of arterial blood flow.