Modulation Of Blood Flow Research Articles

Cerebral hemodynamics in sepsis assessed by transcranial Doppler: a systematic review and meta-analysis.

Cerebral microcirculation is gradually compromised during sepsis, with significant reductions in the function of capillaries and blood perfusion in small vessels. Transcranial Doppler ultrasound (TCD) has been used to assess cerebral circulation in a typical clinical setting. This study was to systematically review TCD studies, assess their methodological quality, and identify trends that can be associated with the temporal evolution of sepsis and its clinical outcome. A meta-analysis of systematic reviews was conducted according to the PRISMA statement. Articles were searched from 1982 until the conclusion of this review in December 2015. Twelve prospective and observational studies were selected. Evaluations of cerebral blood flow, cerebral autoregulation, and carbon dioxide (CO2) vasoreactivity were summarized. A temporal pattern of the evolution of the illness was found. In early sepsis, the median blood flow velocity (Vm) and pulsatility index (PI) increased, and the cerebral autoregulation (CA) remained unchanged. In contrast, Vm normalization, PI reduction and CA impairment were found in later sepsis (patients with severe sepsis or septic shock). Cerebral haemodynamic is impaired in sepsis. Modifications in cerebral blood flow may be consequence to the endothelial dysfunction of the microvasculature induced by the release of inflammatory mediators. A better understanding of cerebral hemodynamics may improve the clinical management of patients with sepsis and, consequently, improve clinical outcomes.

Features of cutaneous microcirculatory blood flow in patients with pulmonary hypertension of different etiology

Aim: to evaluate features of the functional state of microvascular bed of the skin in patients with pulmonary arterial hypertension associated to congenital cardiac disease (PAH-CCD) and chronic thromboembolic pulmonary hypertension (CTEPH). Methods. In study included 25 patients (41.6±15.8) with PAH-CCD, 25 patients (48.8±14.2) with CTEPH and 25 healthy volunteers (39.3±10.1 years). All the patients underwent a six-minute walking test (6-MWT), transthoracic echocardiography, thorax organs radiography, right heart catheterization (RHC) and Laser Doppler flowmetry (LDF) with amplitude and frequency wavelet analysis of blood flow oscillations and evaluation of constrictory and dilatatoryskin resistive microvesselsfunctions. Results. In the PAH-CCD in relation to the CTEPH groupaccording to the RHC were noted significantly higher values of systolic pressure in pulmonary artery (93.2 and 77.8 mm Hg respectively) and venous mixted blood saturation(63 and 57% Hg respectively). On this background 6- MWT distance was 356 and 325 m, the Borg dyspnea scale index was on average 3.12 and 3.76 respectively. According to the LDF pulseoximetry PAH-CCD and CTEPH patients had 90.1 and 94.7% respectively. According to the LDF with amplitude and frequency wavelet analysis the PAH-CCD patients had sig-nificantly higher values of the amplitude of myogenic, respiratory and pulse sectionof blood flow modulation, and also increased constrictory activity smooth muscle cells of skin precapillary arterioles in response to the stretching at venous occlusion and decreased dilatatory reserve at post-occlusi-ve reactive hyperemia. According to the LDF the CTEPH patients had elongationof time development of microvessel constriction in response to acti-vation of sympathetic nervous systemin respiratory and cold tests. Conclusion. According to the LDF functional state of skin microvessels in systemic circulation of the CTEPH patients was comparable with control groupexcept for elongation of time development of microvessel reactions for sympathetic vasoconstrictor stimulations. The PAH-CCD patients demonstrated basal tonus decreasing of smooth muscle cells of skin precapillary arterioles in systemic circulation, which can be regarded as a manifestation of autoregulatory response to systemic hypoxia.

Spatial Measurements of Perfusion, Interstitial Fluid Pressure and Liposomes Accumulation in Solid Tumors.

The heterogeneous intra-tumoral accumulation of liposomes is a critical determinant of their efficacy. Both the chaotic tumor microcirculation and elevated IFP are linked to the heterogeneous intra-tumoral distribution of nanotechnology-based drug delivery systems such as liposomes. In the present study, the relationship between tumor microcirculation, elevated IFP, and accumulation of nanoparticles was investigated through in vivo experimentation. This was accomplished by evaluation of the tumor microcirculation using dynamic contrast enhanced computed tomography (DCE-CT) and measurement of tumor IFP using a novel image-guided robotic needle placement system connected to the micro-CT scanner. The intra-tumoral accumulation of liposomes was determined by CT image-based assessment of a nanoparticle liposomal formulation that stably encapsulate the contrast agent iohexol (CT-liposomes). CT imaging allowed for co-localization of the spatial distribution of tumor hemodynamics, IFP and CT-liposome accumulation in an individual subcutaneous xenograft mouse model of breast cancer. Measurements led to the discovery that perfusion and plasma volume fraction are strong mediators of the intra-tumoral distribution of liposomes. Furthermore, the results suggest that IFP plays an indirect role in mediating liposome distribution through modulating blood flow.

Role of ACTH in the Interactive/Paracrine Regulation of Adrenal Steroid Secretion in Physiological and Pathophysiological Conditions.

In the normal human adrenal gland, steroid secretion is regulated by a complex network of autocrine/paracrine interactions involving bioactive signals released by endothelial cells, nerve terminals, chromaffin cells, immunocompetent cells, and adrenocortical cells themselves. ACTH can be locally produced by medullary chromaffin cells and is, therefore, a major mediator of the corticomedullary functional interplay. Plasma ACTH also triggers the release of angiogenic and vasoactive agents from adrenocortical cells and adrenal mast cells and, thus, indirectly regulates steroid production through modulation of the adrenal blood flow. Adrenocortical neoplasms associated with steroid hypersecretion exhibit molecular and cellular defects that tend to reinforce the influence of paracrine regulatory loops on corticosteroidogenesis. Especially, ACTH has been found to be abnormally synthesized in bilateral macronodular adrenal hyperplasia responsible for hypercortisolism. In these tissues, ACTH is detected in a subpopulation of adrenocortical cells that express gonadal markers. This observation suggests that ectopic production of ACTH may result from impaired embryogenesis leading to abnormal maturation of the adrenogonadal primordium. Globally, the current literature indicates that ACTH is a major player in the autocrine/paracrine processes occurring in the adrenal gland in both physiological and pathological conditions.

Cerebral blood flow modulation insufficiency in brain networks in multiple sclerosis: A hypercapnia MRI study

Cerebrovascular reactivity measures vascular regulation of cerebral blood flow and is responsible for maintaining healthy neurovascular coupling. Multiple sclerosis exhibits progressive neurodegeneration and global cerebrovascular reactivity deficits. This study investigates varied degrees of cerebrovascular reactivity impairment in different brain networks, which may be an underlying cause for functional changes in the brain, affecting long-distance projection integrity and cognitive function; 28 multiple sclerosis and 28 control subjects underwent pseudocontinuous arterial spin labeling perfusion MRI to measure cerebral blood flow under normocapnia (room air) and hypercapnia (5% carbon dioxide gas mixture) breathing. Cerebrovascular reactivity, measured as normocapnic to hypercapnic cerebral blood flow percent increase normalized by end-tidal carbon dioxide change, was determined from seven functional networks (default mode, frontoparietal, somatomotor, visual, limbic, dorsal, and ventral attention networks). Group analysis showed significantly decreased cerebrovascular reactivity in patients compared to controls within the default mode, frontoparietal, somatomotor, and ventral attention networks after multiple comparison correction. Regression analysis showed a significant correlation of cerebrovascular reactivity with lesion load in the default mode and ventral attention networks and with gray matter atrophy in the default mode network. Functional networks in multiple sclerosis patients exhibit varied amounts of cerebrovascular reactivity deficits. Such blood flow regulation abnormalities may contribute to functional communication disruption in multiple sclerosis.

FEATURES OF CUTANEOUS MICROCIRCULATORY BLOOD FLOW IN PATIENTS WITH IDIOPATHIC PULMONARY ARTERIAL HYPERTENSION ASSESSED BY LASER DOPPLER FLOWMETRY DEPENDING ON VASOREACTIVITY STATUS ON INHALED NITRIC OXIDE

Aim: To evaluate features of the functional state of microvascular bed of the skin in patients with idiopathic pulmonary arterial hypertension (IPAH) depending to acute vasoreactivity testing on inhaled nitric oxide. Methods: in study included 28 patients with IPAH (mean age 39,8±13,2 years) and 25 healthy volunteers (39,3±10,1 years). All the patients underwent 6-minuts walking test (6-MWT), transthoracic echocardiography, thorax organs radiography, right heart catheterization (RHC) with acute pharmacological test (APT), laser Doppler flowmetry (LDF) with functional tests. Patients were divided into 2 groups by results of APT. Results: according to the LDF the APT+ patients didn't differ from control group on any of the parameters. The APT-patients according to the basal perfusion also were comparable with control group, but had significantly higher constrictory reactions for all types vasoconstrictor stimulations (at activation of sympathetic nervous system in respiratory and cold tests, and in the development venule-arteriolar constrictory response on venous occlusion) and elongation of time development post-occlusive reactive hyperemia. We identified significant correlation of the amplitude of respiratory section of blood flow modulation, which reflected degree of venule plethora, with the RHC parameters and functional status of patients. Conclusion: In the APT-patients on against a background the of uncharged basal perfusion parameters noticed increased constrictory activity smooth muscle cells of resistive microvessels for all type vasoconstrictor stimulations, but expression of constrictory reactions correlated with indications of patients functional status.

Patterns of Cerebral Blood Flow Modulation During Painful Stimulation in Fibromyalgia: A Transcranial Doppler Sonography Study.

This study analyzed the temporal dynamics of cerebral blood flow (CBF) modulations, during painful stimulation in fibromyalgia syndrome (FMS), using functional transcranial Doppler sonography. Blood flow velocities were recorded bilaterally in the anterior (ACA) and middle (MCA) cerebral arteries of 24 FMS patients and 20 healthy individuals during exposure to painful pressure stimulation. Participants were presented with two stimulation blocks: a) fixed pressure (2.4 kg) and b) stimulation pressure, individually calibrated to produce equal subjective and moderate pain intensity in all participants. A complex pattern of CBF modulations arose, comprising four main components: an anticipatory increase before stimulation onset, an early increase, a transient decrease to baseline or below, and a final increase. Group differences were observed in all components. The anticipatory component only arose in FMS patients, specifically in the ACA. Patients exhibited a greater early CBF increase under the fixed pressure condition, predominantly in the right ACA. A stronger CBF decrease after the early component was observed in patients during the equal pain condition, in the ACA and MCA. Significant associations were found between clinical pain severity and CBF responses in the MCA. The results demonstrate that acute pain processing is associated with a complex pattern of CBF modulation, where FMS patients exhibited alterations in all phases of the response. The aberrances may be ascribed to psychophysiological phenomena, including central nervous nociceptive sensitization and protective-defensive reflex mechanisms. The anticipatory CBF response in patients may relate to various cognitive, emotional, and behavioral mechanisms involved in pain chronification.

Modified Numerical Simulation Model of Blood Flow in Bend.

The numerical simulation model of blood flow in bend is studied in this paper. The curvature modification is conducted for the blood flow model in bend to obtain the modified blood flow model in bend. The modified model is verified by U tube. By comparing the simulation results with the experimental results obtained by measuring the flow data in U tube, it was found that the modified blood flow model in bend can effectively improve the prediction accuracy of blood flow data affected by the curvature effect.

0259 : Neutrophil and thrombospondin-1 implications in flow-mediated remodeling of resistance arteries from mice

On vascular endothelium, shear stress produces vasorelaxation and outward arterial remodeling. A chronic increase in blood flow induces arterial diameter expansion (normalizing shear stress), and is associated with a compensatory hypertrophy to normalize wall strain. This remodeling is due to Inflammation and nitric oxide (NO) production in resistance arteries. A large number of studies have demonstrated that Thrombospondin-1 (TSP1), a homotrimeric glycoprotein, can have an inhibitory action on the NO pathway and a positive effect on inflammation in vitro . Nevertheless, the role of TSP1 on remodeling is poorly understood. We hypothesized that TSP1 is able to participate in this outward arterial remodeling and hypertrophy by immune cells recruitment. We investigated this remodeling in mesenteric resistance arteries of WT or TSP1-KO mice aged to 12-16 weeks were used. An IgG2a isotype control mAb 2A3 or Ly6G-specific mAb 1A8 are used for neutrophil depletion by in vivo administration. Ligation of mesenteric resistance arteries of WT/TSP1- KO and IgG2a/neutrophil-depleted mice allowed modifying blood flow in vivo, thus exposing arteries to low (LF), normal (NF), or high flow (HF). After 7 days, arteries were isolated for in vitro study. Phenylephrine-mediated contraction and Acetylcholine-mediated relaxation were stronger in HF than in NF vessels on WT and IgG2a control mice. Any difference between HF or NF in TSP1-KO and neutrophil-depleted mice were found. Furthermore, passive diameter analysis revealed a higher diameter in HF than NF in WT and IgG2a mice. These differences are lost in TSP1-KO and neutrophil-depleted mice. These results suggest that TSP1 are essential for remodeling in mesenteric arteries by promoting neutrophils recruitment. The author hereby declares no conflict of interest

H2S Regulates Hypobaric Hypoxia-Induced Early Glio-Vascular Dysfunction and Neuro-Pathophysiological Effects

Hypobaric Hypoxia (HH) is an established risk factor for various neuro-physiological perturbations including cognitive impairment. The origin and mechanistic basis of such responses however remain elusive. We here combined systems level analysis with classical neuro-physiological approaches, in a rat model system, to understand pathological responses of brain to HH. Unbiased ‘statistical co-expression networks’ generated utilizing temporal, differential transcriptome signatures of hippocampus—centrally involved in regulating cognition—implicated perturbation of Glio-Vascular homeostasis during early responses to HH, with concurrent modulation of vasomodulatory, hemostatic and proteolytic processes. Further, multiple lines of experimental evidence from ultra-structural, immuno-histological, substrate-zymography and barrier function studies unambiguously supported this proposition. Interestingly, we show a significant lowering of H2S levels in the brain, under chronic HH conditions. This phenomenon functionally impacted hypoxia-induced modulation of cerebral blood flow (hypoxic autoregulation) besides perturbing the strength of functional hyperemia responses. The augmentation of H2S levels, during HH conditions, remarkably preserved Glio-Vascular homeostasis and key neuro-physiological functions (cerebral blood flow, functional hyperemia and spatial memory) besides curtailing HH-induced neuronal apoptosis in hippocampus. Our data thus revealed causal role of H2S during HH-induced early Glio-Vascular dysfunction and consequent cognitive impairment.

Delayed Treatment with Sodium Hydrosulfide Improves Regional Blood Flow and Alleviates Cecal Ligation and Puncture (CLP)-Induced Septic Shock.

Cecal ligation and puncture (CLP)-induced sepsis is a serious medical condition, caused by a severe systemic infection resulting in a systemic inflammatory response. Recent studies have suggested the therapeutic potential of donors of hydrogen sulfide (H2S), a novel endogenous gasotransmitter and biological mediator in various diseases. The aim of the present study was to assess the effect of H2S supplementation in sepsis, with special reference to its effect on the modulation of regional blood flow. We infused sodium hydrosulfide (NaHS), a compound that produces H2S in aqueous solution (1, 3, or 10 mg/kg/h, for 1 h at each dose level) in control rats or rats 24 h after CLP, and measured blood flow using fluorescent microspheres. In normal control animals, NaHS induced a characteristic redistribution of blood flow, and reduced cardiac, hepatic, and renal blood flow in a dose-dependent fashion. In contrast, in rats subjected to CLP, cardiac, hepatic, and renal blood flow was significantly reduced; infusion of NaHS (1 mg/kg/h and 3 mg/kg/h) significantly increased organ blood flow. In other words, the effect of H2S on regional blood flow is dependent on the status of the animals (i.e., a decrease in blood flow in normal controls, but an increase in blood flow in CLP). We have also evaluated the effect of delayed treatment with NaHS on organ dysfunction and the inflammatory response by treating the animals with NaHS (3 mg/kg) intraperitoneally (i.p.) at 24 h after the start of the CLP procedure; plasma levels of various cytokines and tissue indicators of inflammatory cell infiltration and oxidative stress were measured 6 h later. After 24 h of CLP, glomerular function was significantly impaired, as evidenced by markedly increased (over 4-fold over baseline) blood urea nitrogen and creatinine levels; this increase was also significantly reduced by treatment with NaHS. NaHS also attenuated the CLP-induced increases in malondialdehyde levels (an index of oxidative stress) in heart as well as in liver and myeloperoxidase levels (an index of neutrophil infiltration) in heart and lung. Plasma levels of IL-1β, IL-5, IL-6, TNF-α, and HMGB1 were attenuated by NaHS. Treatment of NaHS at 3 mg/kg i.p. (but not 1 mg/kg or 6 mg/kg), starting 24 h post-CLP, with dosing repeated every 6 h, improved the survival rate in CLP animals. In summary, treatment with 3 mg/kg H2S-when started in a delayed manner, when CLP-induced organ injury, inflammation and blood flow redistribution have already ensued-improves blood flow to several organs, protects against multiple organ failure, and reduces the plasma levels of multiple pro-inflammatory mediators. These findings support the view that H2S donation may have therapeutic potential in sepsis.

Running marathons with an ileostomy: overcoming all challenges

Gastrointestinal NursingVol. 14, No. 2 Sports + StomaRunning marathons with an ileostomy: overcoming all challengesKate BensonKate BensonSearch for more papers by this authorKate BensonPublished Online:14 Mar 2016https://doi.org/10.12968/gasn.2016.14.2.18AboutSectionsView articleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InEmail View article References Cancer Research UK (2015) Are there exercise guidelines for cancer patients? bit.ly/1QRafOf (accessed 4 march 2016) Google ScholarMcCullough DJ, Stabley JN, Siemann DW, Behnke BJ (2014) Modulation of blood flow, hypoxia, and vascular function in orthotopic prostate tumors during exercise. J Natl Cancer Inst 106(4): dju036. doi: https://doi.org/10.1093/jnci/dju036 Crossref, Google ScholarMcGrath A, Porrett T, Heyman B (2006) Parastomal hernia: an exploration of the risk factors and the implications. Br J Nurs 15(6): 317–21 Link, Google ScholarMeyerhardt JA, Giovannucci EL, Holmes MD et al. (2006) Physical activity and survival after colorectal cancer diagnosis. J Clin Oncol 24(22): 3527–34 Crossref, Google ScholarNational Cancer Institute (2009) Physical Activity and Cancer. What is the relationship between physical activity and colon cancer risk? 1.usa.gov/1Uw1vCZ (accessed 1 March 2016) Google ScholarRichbourg L (2012) Food fight: dietary choices made by people after stoma formation. Gastrointestinal Nursing 10(4): 44–50. doi: https://doi.org/10.12968/gasn.2012.10.4.44 Link, Google ScholarThompson M, Trainor B (2007) Prevention of parastomal hernia: a comparison of results 3 years on. Gastrointestinal Nursing 5(3): 22–8. doi: https://doi.org/10.12968/gasn.2007.5.3.23472 Link, Google Scholar FiguresReferencesRelatedDetails 2 March 2016Volume 14Issue 2ISSN (print): 1479-5248ISSN (online): 2052-2835 Metrics History Published online 14 March 2016 Published in print 2 March 2016 Information© MA Healthcare LimitedPDF download

EDH: endothelium-dependent hyperpolarization and microvascular signalling.

Endothelium-dependent hyperpolarizing factor (EDHF) is a powerful vasodilator influence in small resistance arteries and thus an important modulator of blood pressure and flow. As the name suggests, EDHF was thought to describe a diffusible factor stimulating smooth muscle hyperpolarization (and thus vasodilatation). However, this idea has evolved with the recognition that a factor can operate alongside the spread of hyperpolarizing current from the endothelium to the vascular smooth muscle (VSM). As such, the pathway is now termed endothelium-dependent hyperpolarization (EDH). EDH is activated by an increase in endothelial [Ca2+ ]i , which stimulates two Ca2+ -sensitive K channels, SKCa and IKCa . This was discovered because apamin and charybdotoxin applied in combination blocked EDHF responses, but iberiotoxin - a blocker of BKCa - was not able to substitute for charybdotoxin. SKCa and IKCa channels are arranged in endothelial microdomains, particularly within projections towards the adjacent smooth muscle, which are rich in IKCa channels and close to interendothelial gap junctions where SKCa channels, are prevalent. KCa activation hyperpolarizes endothelial cells, and K+ efflux through them can act as a diffusible 'EDHF' by stimulating VSM Na+ ,K+ -ATPase and inwardly rectifying K channels (KIR ). In parallel, hyperpolarizing current spreads from the endothelium to the smooth muscle through myoendothelial gap junctions located on endothelial projections. The resulting radial EDH is complemented by the spread of 'conducted' hyperpolarization along the endothelium of arteries and arterioles to affect conducted vasodilatation (CVD). Retrograde CVD effectively integrates blood flow within the microcirculation, but how the underlying hyperpolarization is sustained is unclear.

Abstract WMP48: Delayed Intravenous Administration of Drag Reducing Polymers Improves Brain Microcirculation and Neurologic Outcome After Permanent Middle Cerebral Artery Occlusion in Rats

Introduction: Tissue plasminogen activator is used in only 5% of stroke patients because therapeutic window is short (∼3 hr) due to risk of hemorrhage. Rheological modulation of blood flow by nanomolar concentrations of drag-reducing polymers (DRP) improved hemodynamics and survival in animal models of the ischemic myocardium and limb. We previously showed that DRP applied early at 30 min after permanent middle cerebral artery occlusion (pMCAO) restored microvascular perfusion and improved neurologic outcome. We hypothesized that DRP applied after 3 hr delay would be effective in improving recovery. Methods: DRP or saline (control) were i.v. injected 3 hours after pMCAO in rats. Evaluation of the acute DRP effects (5 hours after pMCAO) on microvascular perfusion, hypoxia (NADH) and blood brain barrier (BBB) was done by in-vivo 2-photon laser scanning microscopy (2PLSM) and followed by brain perfusion for Fluoro-Jade staining for neurodegeneration. Cerebral infarction and perfusion were evaluated by MRI at 24 hours, 1 and 3 weeks after pMCAO. Motor function was evaluated by Rotarod test at 1, 2 and 3 weeks after pMCAO. Results: DRP compared to saline, applied after 3 hours following pMCAO, improved impaired microvascular circulation in the penumbra of the parietal cortex (Δ=33 %), reducing hypoxia (Δ=27 %) and BBB damage (Δ=42 %) thereby protecting neurons from neurodegeneration (Fluoro-Jade, Δ=36 %) (n=4, p<0.05). After prolonged recovery, DRP solution compared to saline reduced infarct expansion (Δ=23 %) and increased cerebral blood flow (Δ=31 %) in the penumbra at 24 hours, 1 and 3 weeks after pMCAO as measured by MRI (n=6, p<0.05). Rotarod tests showed that DRP treated rats performed better than saline treated (Δ=35 %) at 1, 2 and 3 weeks after the pMCAO (n=6, p<0.05). Conclusions: Rheological enhancement of cerebral microcirculation by DRP improved neurologic outcome after permanent MCAO without reperfusion even with delayed application after stroke onset. Potential DRP mechanisms involve improved collateral flow and anti-inflammatory effects of the increased shear stress with enhanced microcirculatory flow. DRP may be an effective therapy for ischemic stroke even without reperfusion and after delayed administration following the stroke onset.

Oral L-citrulline supplementation enhances cycling time trial performance in healthy trained men: Double-blind randomized placebo-controlled 2-way crossover study.

BackgroundMany human studies report that nitric oxide (NO) improves sport performance. This is because NO is a potential modulator of blood flow, muscle energy metabolism, and mitochondrial respiration during exercise. L-Citrulline is an amino acid present in the body and is a potent endogenous precursor of L-arginine, which is a substrate for NO synthase. Here, we investigated the effect of oral L-citrulline supplementation on cycling time trial performance in humans.MethodsA double-blind randomized placebo-controlled 2-way crossover study was employed. Twenty-two trained males consumed 2.4 g/day of L-citrulline or placebo orally for 7 days. On Day 8 they took 2.4 g of L-citrulline or placebo 1 h before a 4-km cycling time trial. Time taken to complete the 4 km cycle, along with power output/VO2 ratio (PO/VO2), plasma nitrite and nitrate (NOx) and amino acid levels, and visual analog scale (VAS) scores, was evaluated.ResultsL-Citrulline supplementation significantly increased plasma L-arginine levels and reduced completion time by 1.5 % (p < 0.05) compared with placebo. Moreover, L-citrulline significantly improved subjective feelings of muscle fatigue and concentration immediately after exercise.ConclusionsOral L-citrulline supplementation reduced the time take to complete a cycle ergometer exercise trial.Trial registrationCurrent Controlled Trials UMIN000014278.

Does modification of portal venous blood flow using balloon-occluded retrograde transvenous obliteration affect the mucosa of the small intestine?

Does modification of portal venous blood flow using balloon-occluded retrograde transvenous obliteration affect the mucosa of the small intestine?

Microcirculation impairment in periodontal tissues in patients with chronic generalized periodontitis combined with metabolic syndrome

Using the method of laser Doppler flowmetry the study of microcirculation in periodontal tissues in patients with moderate chronic generalized periodontitis and metabolic syndrome was carried out. The analysis of microcirculation values proved not only the reduction of blood flow intensity but also the decreased vasoactivity of microvessels essential to maintain normal microcirculation in periodontal tissues, as it provides active modulation of tissue blood flow and its adaptation to local metabolic needs.

Особенности микроциркуляторного кровотока в коже у больных легочной гипертензией разной этиологии

Aim: to evaluate features of the functional state of microvascular bed of the skin in patients with pulmonary arterial hypertension associated to congenital cardiac disease (PAH-CCD) and chronic thromboembolic pulmonary hypertension (CTEPH). Methods. In study included 25 patients (41.6±15.8) with PAH-CCD, 25 patients (48.8±14.2) with CTEPH and 25 healthy volunteers (39.3±10.1 years). All the patients underwent a six-minute walking test (6-MWT), transthoracic echocardiography, thorax organs radiography, right heart catheterization (RHC) and Laser Doppler flowmetry (LDF) with amplitude and frequency wavelet analysis of blood flow oscillations and evaluation of constrictory and dilatatoryskin resistive microvesselsfunctions. Results. In the PAH-CCD in relation to the CTEPH groupaccording to the RHC were noted significantly higher values of systolic pressure in pulmonary artery (93.2 and 77.8 mm Hg respectively) and venous mixted blood saturation(63 and 57% Hg respectively). On this background 6- MWT distance was 356 and 325 m, the Borg dyspnea scale index was on average 3.12 and 3.76 respectively. According to the LDF pulseoximetry PAH-CCD and CTEPH patients had 90.1 and 94.7% respectively. According to the LDF with amplitude and frequency wavelet analysis the PAH-CCD patients had sig-nificantly higher values of the amplitude of myogenic, respiratory and pulse sectionof blood flow modulation, and also increased constrictory activity smooth muscle cells of skin precapillary arterioles in response to the stretching at venous occlusion and decreased dilatatory reserve at post-occlusi-ve reactive hyperemia. According to the LDF the CTEPH patients had elongationof time development of microvessel constriction in response to acti-vation of sympathetic nervous systemin respiratory and cold tests. Conclusion. According to the LDF functional state of skin microvessels in systemic circulation of the CTEPH patients was comparable with control groupexcept for elongation of time development of microvessel reactions for sympathetic vasoconstrictor stimulations. The PAH-CCD patients demonstrated basal tonus decreasing of smooth muscle cells of skin precapillary arterioles in systemic circulation, which can be regarded as a manifestation of autoregulatory response to systemic hypoxia.

Nonsurgical therapy for hydrocephalus: a comprehensive and critical review.

Pharmacological interventions have been tested experimentally and clinically to prevent hydrocephalus and avoid the need for shunting beginning in the 1950s. Clinical trials of varied quality have not demonstrated lasting and convincing protective effects through manipulation of cerebrospinal fluid production, diuresis, blood clot fibrinolysis, or manipulation of fibrosis in the subarachnoid compartment, although there remains some promise in the latter areas. Acetazolamide bolus seems to be useful for predicting shunt response in adults with hydrocephalus. Neuroprotection in the situation of established hydrocephalus has been tested experimentally beginning more recently. Therapies designed to modify blood flow or pulsation, reduce inflammation, reduce oxidative damage, or protect neurons are so far of limited success; more experimental work is needed in these areas. As has been recommended for preclinical studies in stroke and brain trauma, stringent conditions should be met for preclinical studies in hydrocephalus.Electronic supplementary materialThe online version of this article (doi:10.1186/s12987-016-0025-2) contains supplementary material, which is available to authorized users.

Partial pharmacologic blockade demonstrates sympathetic influence on the phase angle between oscillations in blood pressure and cerebral blood flow modulation

Partial pharmacologic blockade demonstrates sympathetic influence on the phase angle between oscillations in blood pressure and cerebral blood flow modulation