Correlação entre medidas ecocardiográficas e hemodinâmicas na avaliação do átrio direito e ventrículo direito em pacientes com hipertensão pulmonar / Correlation between echocardiographic and hemodynamic measurements in right atrium and right ventricle assessments of patients with pulmonary hypertension

Introdução: Hipertensão Pulmonar (HP), uma condição clínica grave, pode levar à disfunção sistólica do ventrículo direto (DSVD), com implicações prognósticas. Pacientes com suspeita de HP devem ser submetidos ao ecocardiograma transtorácico (ECOTT) para diagnóstico e avaliação, colocando-o como o principal exame de triagem e acompanhamento. Objetivo: Verificar a associação e a concordância das medidas referentes à pressão média no átrio direito (AD) e à disfunção sistólica do ventrículo direto (DSVD) ao (ECOTT) e ao cateterismo de câmaras direitas (CCD) em pacientes com (HP). Métodos: Foram incluídos indivíduos com diagnóstico de (HP). Todos os pacientes foram submetidos ao ECOTT e CCD. Avaliou-se pelo ECOTT: área do átrio direito (AAD), pressão média do átrio direito (AD) através por meio do diâmetro e da colapsabilidade da veia cava inferior (PMADECOTT ), strain AD (SAD), TAPSE (excursão sistólica do plano anular tricúspide), MAF (mudança da área fracional), SPLVD (strain da parede livre do VD) e onda s´ tricuspídea. Pelo CCD avaliaram-se pressão média do (PMADCCD ) e índice cardíaco (IC). Resultados: Dos 16 pacientes, 13 eram do sexo feminino. A idade média foi de 44,4 anos (±14,9). Constataram-se associação entre pressão média do átrio direito PMADCCD com área do átrio direito, PMADECOTT pressão média do átrio direito e SAD strain do átrio direito (r=0,845, r=0,621 e r=-0,523, respectivamente; p< 0,05). Verificou-se associação entre as categorias de risco de mortalidade, mensuradas pelas medidas AAD da área do átrio direito e pressão média do átrio direito PMADCCD (X2=10,42; p=0,003), com concordância moderada (k=0,44; p=0,012). DSVD A disfunção sistólica do ventrículo direto estava presente em dez pacientes. Houve associação entre disfunção sistólica do ventrículo direto DSVD (presente ou ausente) e índice cardíaco IC (r=0,522; p=0,04), com concordância moderada (k=0,43; p=0,037). Conclusão: As medidas do ecocardiograma transtorácico (ECOTT) e cateterismo de câmara direita (CCD) demostraram associação na avaliação da pressão média do átrio direito com melhor associação entre área do átrio direito AAD e pressão média do átrio direito (PMADCCD) . Houve associação com concordância moderada quanto à disfunção sistólica do ventrículo direto (DSVD) entre métodos. (AU)

Introduction: Pulmonary hypertension (PH), a serious clinical condition, can lead to right ventricular systolic dysfunction (RVSD) with prognostic implications. Patients with suspected PH should undergo transthoracic echocardiography (TTE) for diagnosis and evaluation as the main screening and follow-up exam. Objective: To verify the associations of and agreement between measurements of mean pressure in the right atrium (RA) and RVSD with TTE Method: Individuals diagnosed with PH were included. All patients underwent TTE and RCC. The following were evaluated by TTE: right atrial area (RAA), mean right atrial pressure through the diameter and collapsibility of the inferior vena cava (RMAPTTE), RA strain (RAS), tricuspid annular plane systolic excursion, fractional area change, RV free wall strain, and tricuspid s' wave. Mean RA pressure (RMAPRCC) and cardiac index (CI) were evaluated through the RCC. Results: Of the 16 patients, 13 were female. The mean patient age was 44.4 (±14.9) years. An association was found between RMAPRCC and AAD, RMAPTTE, and RAS (r=0.845, r=0.621, and r=-0.523, respectively; p<0.05). There was an association between the mortality risk categories measured by the RAA and RMAPRCC measures (X2=10.42; p=0.003), with moderate agreement (k=0.44; p=0.012). RVSDJ was present in 10 patients. There was an association between RVSD (present or absent) and CI (r=0.522; p=0.04) with moderate agreement (k=0.43; p=0.037). Conclusion: The TTE and RCC measurements showed an association in the assessment of mean right atrial pressure, especially between RAA and RMAPRCC. An association with RVSD and moderate agreement between methods were also noted. (AU)

Photobiomodulation induces hypotensive effect in spontaneously hypertensive rats.

To evaluate whether acute photobiomodulation can elicit a hypotensive effect in spontaneously hypertensive rats (SHR). Male SHR were submitted to the implantation of a polyethylene cannula into the femoral artery. After 24 h, baseline measurements of the hemodynamic parameters: systolic, diastolic, and mean arterial pressure, and heart rate were accomplished for 1 h. Afterwards, laser application was simulated, and the hemodynamic parameters were recorded for 1 h. In the same animal, the laser was applied at six different positions of the rat's abdomen, and the hemodynamic parameters were also recorded until the end of the hypotensive effect. The irradiation parameters were red wavelength (660 nm); average optical power of 100 mW; 56 s per point (six points); spot area of 0.0586 cm2; and irradiance of 1.71 W/cm2 yielding to a fluency of 96 J/cm2 per point. For measuring plasma NO levels, blood was collected before the recording, as well as immediately after the end of the mediated hypotensive effect. Photobiomodulation therapy was able to reduce the systolic arterial pressure in 69% of the SHR submitted to the application, displaying a decrease in systolic, diastolic, and mean arterial pressure. No change in heart rate was observed. Nevertheless, there was an increase in serum nitric oxide levels in the SHR responsive to photobiomodulation. Our results suggest that acute irradiation with a red laser at 660 nm can elicit a hypotensive effect in SHR, probably by a mechanism involving the release of NO, without changing the heart rate.

Stiff left atrial syndrome after low-dose radiotherapy for right breast cancer: The need for invasive hemodynamics at exercise.

Stiff left atrial (LA) syndrome is a distinct phenotype of heart failure with preserved ejection fraction, characterized by predominant high LA pressure. We describe the case of a middle-aged woman who developed exertional breathlessness during low-dose radiotherapy for right breast cancer and who was eventually found to be affected by stiff LA syndrome. Invasive hemodynamics allowed the recognition of pathognomonic tall V waves in the wedge position during exercise, in spite of inconclusive noninvasive investigations.

Hemodynamic Effects on Particle Targeting in the Arterial Bifurcation for Different Magnet Positions.

The present study investigated the possibilities and feasibility of drug targeting for an arterial bifurcation lesion to influence the host healing response. A micrometer sized iron particle was used only to model the magnetic carrier in the experimental investigation (not intended for clinical use), to demonstrate the feasibility of the particle targeting at the lesion site and facilitate the new experimental investigations using coated superparamagnetic iron oxide nanoparticles. Magnetic fields were generated by a single permanent external magnet (ferrite magnet). Artery bifurcation exerts severe impacts on drug distribution, both in the main vessel and the branches, practically inducing an uneven drug concentration distribution in the bifurcation lesion area. There are permanently positioned magnets in the vicinity of the bifurcation near the diseased area. The generated magnetic field induced deviation of the injected ferromagnetic particles and were captured onto the vessel wall of the test section. To increase the particle accumulation in the targeted region and consequently avoid the polypharmacology (interaction of the injected drug particles with multiple target sites), it is critical to understand flow hemodynamics and the correlation between flow structure, magnetic field gradient, and spatial position.

Role of perfusion CT in the evaluation of metastatic nodal tumor response after radiochemotherapy in head and neck cancer: preliminary findings.

OBJECTIVE: To assess changes of CT perfusion parameters (ΔPCTp) of cervical lymph node metastases from head and neck cancer (HNC) before and after radiochemotherapy (RT-CT) and their association with nodal tumor persistence. PATIENTS AND METHODS: Eligibility criteria included HNC (Stage III-IV) candidates for RT-CT. Patients underwent perfusion CT (PCT) at baseline 3 weeks and 3 months after RT-CT. Blood volume (BV), blood flow (BF), mean transit time (MTT) and permeability surface (PS) were calculated. PET/CT examination was also performed at baseline and 3 months after treatment for metabolic assessment. RESULTS: Between July 2012 and May 2016, 27 patients were evaluated. Overall, only 3 patients (11%) experienced tumor persistence in the largest metastatic lymph node. A significant reduction of all PCTp values (p<0.0001), except MTT (from 6.3 to 5.7 s; p=0.089), was observed at 3 weeks post-RT-CT compared to baseline. All PCTp values including MTT were significantly lower at 3-month follow-up compared to baseline (p<0.05). Moreover, a statistically significant association was observed between nodal tumor persistence and high BF values (p=0.045) at 3 months after treatment that did not occur for the other parameters. CONCLUSIONS: Our preliminary findings show that all PCTp except MTT are significantly reduced after RT-CT. High BF values at 3 months post-RT-CT are predictive of nodal tumor persistence.

Hemodynamic Flow-Induced Mechanotransduction Signaling Influences the Radiation Response of the Vascular Endothelium.

Hemodynamic shear stress is defined as the physical force exerted by the continuous flow of blood in the vascular system. Endothelial cells, which line the inner layer of blood vessels, sense this physiological force through mechanotransduction signaling and adapt to maintain structural and functional homeostasis. Hemodynamic flow, shear stress and mechanotransduction signaling are, therefore, an integral part of endothelial pathophysiology. Although this is a well-established concept in the cardiovascular field, it is largely dismissed in studies aimed at understanding radiation injury to the endothelium and subsequent cardiovascular complications. We and others have reported on the differential response of the endothelium when the cells are under hemodynamic flow shear compared with static culture. Further, we have demonstrated significant differences in the gene expression of static versus shear-stressed irradiated cells in four key pathways, reinforcing the importance of shear stress in understanding radiation injury of the endothelium. This article further emphasizes the influence of hemodynamic shear stress and the associated mechanotransduction signaling on physiological functioning of the vascular endothelium and underscores its significance in understanding radiation injury to the vasculature and associated cardiac complications. Studies of radiation effect on endothelial biology and its implication on cardiotoxicity and vascular complications thus far have failed to highlight the significance of these factors. Factoring in these integral parts of the endothelium will enhance our understanding of the contribution of the endothelium to radiation biology. Without such information, the current approaches to studying radiation-induced injury to the endothelium and its consequences in health and disease are limited.

[Impact of low level laser therapy on skin blood flow]. / Wplyw niskoenergetycznej laseroterapiina skorny przeplyw krwi.

UNLABELLED: The aim of this study was to objectively assess the impact of low level laser therapy on skin blood flow, in terms of two of its components - the flow and trophic and therapeutic effect. MATERIAL AND METHODS: Nineteen children aged 3-15 years have been included in the study (seven boys and twelve girls) with a diagnosis of meningomyelocele in the lumbosacral area. In nine of them (47.3%) bedsores were found in the area of paresis location. Studies of skin blood flow were performed using xenon 133 clearance in the Department of Nuclear Medicine of the Children's Memorial Health Institute. Xenon 133 radioisotope in saline with intrinsic activity 74 MBq in 1 ml was used as the marker. Laser application was performed immediately prior to the application of the marker with a tag shower 60 mW probe, emitting 680 nm red light with surface power density of 0.5 J/cm2. RESULTS: Within the tested children the laser application resulted in a significantly increased skin blood flow. Average results in tested group before LLLT are 7.47 ml/100 g/min, after LLLT 11.08 ml/100 g/min. CONCLUSIONS: 1. LLLT significantly increases the perfusion of the skin. 2. The effect of the increased perfusion as the result of laserotherapy in the most evident in children with skin trophic abnormalities. 3. Results confirmed by clinical observation indicate, that perfusion increase in relation to LLLT takes place with participation of trophic component of skin blood circulation.

Sestrin2 protects the myocardium against radiation-induced damage.

The purpose of this study was to investigate the role of Sestrin2 in response to radiation-induced injury to the heart and on the cardiomyopathy development in the mouse. Mice with genetic deletion of the Sestrin2 (Sestrin2 knockout mice [Sestrin2 KO]) and treatment with irradiation (22 or 15 Gy) were used as independent approaches to determine the role of Sestrin2. Echocardiography (before and after isoproterenol challenge) and left ventricular (LV) catheterization were performed to evaluate changes in LV dimensions and function. Masson's trichrome was used to assess myocardial fibrosis. Immunohistochemistry and Western blot were used to detect the capillary density. After 22 or 15 Gy irradiation, the LV ejection fraction (EF) was impaired in wt mice at 1 week and 4 months after irradiation when compared with sham irradiation. Compared to wt mice, Sestrin2 KO mice had significant reduction in reduced LVEF at 1 week and 4 months after irradiation. A significant increase in LV end-diastolic pressure and myocardial fibrosis and a significant decrease in capillary density were observed in irradiation-wt mice, as well as in irradiation-Sestrin2 KO mice. Sestrin2 involved in the regulation of cardiomyopathy (such as myocardial fibrosis) after irradiation. Overexpression of Sestrin2 might be useful in limiting radiation-induced myocardial injury.

Transcranial laser stimulation improves human cerebral oxygenation.

BACKGROUND AND OBJECTIVE: Transcranial laser stimulation of the brain with near-infrared light is a novel form of non-invasive photobiomodulation or low-level laser therapy (LLLT) that has shown therapeutic potential in a variety of neurological and psychological conditions. Understanding of its neurophysiological effects is essential for mechanistic study and treatment evaluation. This study investigated how transcranial laser stimulation influences cerebral hemodynamics and oxygenation in the human brain in vivo using functional near-infrared spectroscopy (fNIRS). MATERIALS AND METHODS: Two separate experiments were conducted in which 1,064-nm laser stimulation was administered at (1) the center and (2) the right side of the forehead, respectively. The laser emitted at a power of 3.4 W and in an area of 13.6 cm2, corresponding to 0.25 W/cm2 irradiance. Stimulation duration was 10 minutes. Nine healthy male and female human participants of any ethnic background, in an age range of 18-40 years old were included in each experiment. RESULTS: In both experiments, transcranial laser stimulation induced an increase of oxygenated hemoglobin concentration (Δ[HbO2 ]) and a decrease of deoxygenated hemoglobin concentration (Δ[Hb]) in both cerebral hemispheres. Improvements in cerebral oxygenation were indicated by a significant increase of differential hemoglobin concentration (Δ[HbD] = Δ[HbO2 ] - Δ[Hb]). These effects increased in a dose-dependent manner over time during laser stimulation (10 minutes) and persisted after laser stimulation (6 minutes). The total hemoglobin concentration (Δ[HbT] = Δ[HbO2] + Δ[Hb]) remained nearly unchanged in most cases. CONCLUSION: Near-infrared laser stimulation applied to the forehead can transcranially improve cerebral oxygenation in healthy humans.

Varicose veins of lower extremities, hemodynamics and treatment methods.

Chronic venous insufficiency is one of the most common disorders of the vascular system, affecting approximately 50% of adults. If left untreated it can lead to a number of complications, including venous ulceration and venous thrombosis. This review paper outlines the epidemiology and ethiopathogenesis of the disease with regard to hemodynamics and microcirculation disturbances. It describes the medical treatment as well as the traditional surgical approach to varicose veins (with several modifications of this technique), and its limitations and contraindications. Furthermore, it discusses a number of new, minimally invasive treatment methods, namely thermal in form (radiofrequency ablation, endovenous laser ablation, steam ablation) and nonthermal (sclerotherapy, echosclerotherapy, Clarivein, Sapheon). For each method, there is a brief historical overview, a description of its mechanism of action, and its indications and limitations. The results of comparative studies on individual treatment methods as well as meta-analyses on this topic are briefly discussed. This paper highlights the progressive trend towards minimally invasive methods and attempts to predict the further development.

Effect of Mobile Phone-Induced Electromagnetic Field on Brain Hemodynamics and Human Stem Cell Functioning: Possible Mechanistic Link to Cancer Risk and Early Diagnostic Value of Electronphotonic Imaging.

The mobile phones (MP) are low power radio devices which work on electromagnetic fields (EMFs), in the frequency range of 900-1800 MHz. Exposure to MPEMFs may affect brain physiology and lead to various health hazards including brain tumors. Earlier studies with positron emission tomography (PET) have found alterations in cerebral blood flow (CBF) after acute exposure to MPEMFs. It is widely accepted that DNA double-strand breaks (DSBs) and their misrepair in stem cells are critical events in the multistage origination of various leukemia and tumors, including brain tumors such as gliomas. Both significant misbalance in DSB repair and severe stress response have been triggered by MPEMFs and EMFs from cell towers. It has been shown that stem cells are most sensitive to microwave exposure and react to more frequencies than do differentiated cells. This may be important for cancer risk assessment and indicates that stem cells are the most relevant cellular model for validating safe mobile communication signals. Recently developed technology for recording the human bio-electromagnetic (BEM) field using Electron photonic Imaging (EPI) or Gas Discharge Visualisation (GDV) technique provides useful information about the human BEM. Studies have recorded acute effects of Mobile Phone Electromagnetic Fields (MPEMFs) using EPI and found quantifiable effects on human BEM field. Present manuscript reviews evidences of altered brain physiology and stem cell functioning due to mobile phone/cell tower radiations, its association with increased cancer risk and explores early diagnostic value of EPI imaging in detecting EMF induced changes on human BEM.

Hemodynamic effect of laser therapy in spontaneously hypertensive rats.

Systemic arterial hypertension (SAH) is considered to be the greatest risk factor for the development of neuro-cardiovascular pathologies, thus constituting a severe Public Health issue in the world. The Low-Level Laser Therapy (LLLT), or laser therapy, activates components of the cellular structure, therefore converting luminous energy into photochemical energy and leading to biophysical and biochemical reactions in the mitochondrial respiratory chain. The LLLT promotes cellular and tissue photobiomodulation by means of changes in metabolism, leading to molecular, cellular and systemic changes. The objective of this study was to analyze the action of low-level laser in the hemodynamic modulation of spontaneously hypertensive rats, in the long term. Animals (n = 16) were randomly divided into the Laser Group (n = 8), which received three weekly LLLT irradiations for seven weeks, and into the Sham Group (n = 8), which received three weekly simulations of laser for seven weeks, accounting for 21 applications in each group. After seven weeks, animals were cannulated by the implantation of a catheter in the left carotid artery. On the following day, the systemic arterial pressure was recorded. The Laser Group showed reduced levels of mean blood pressure, with statistically significant reduction (169 ± 4 mmHg* vs. 182 ± 4 mmHg from the Sham Group) and reduced levels of diastolic pressure (143 ± 4 mmHg* vs. 157 ± 3 mmHg from the Sham Group), revealing a 13 and 14 mmHg decrease, respectively. Besides, there was a concomitant important decline in heart rate (312 ± 14 bpm vs. 361 ± 13 bpm from the Sham Group). Therefore, laser therapy was able to produce hemodynamic changes, thus reducing pressure levels in spontaneously hypertensive rats.

Efeitos hemodinâmicos da ventilação não invasiva em pacientes submetidos à cirurgia de revascularização do miocárdio

As doenças cardiovasculares no Brasil, são responsáveis por 29% das mortes, principalmente por infarto agudo do miocárdio. A pesquisa se propôs: verificar possíveis alterações hemodinâmicas com uso da ventilação não invasiva (VNI), na modalidade CPAP em pacientes em pós-operatório de cirurgia de revascularização do miocárdio...

Cardiovascular disease in Brazil, account for 29% of deaths, mainly acute myocardial infarction. The research proposed: check possible hemodynamic changes with use of noninvasive ventilation (NIV) in CPAP in patients in postoperative coronary artery bypass surgery...

Long-term effects of neck irradiation on cardiovascular autonomic function: a study in nasopharyngeal carcinoma patients after radiotherapy.

INTRODUCTION: Baroreflex failure has been reported as a late sequalum of neck radiotherapy. In this study we investigated cardiovascular autonomic function in patients after neck radiotherapy to determine predictive factors associated with outcome. METHODS: Eighty-nine patients with nasopharyngeal carcinoma were evaluated ≥6 months after radiotherapy for cardiovascular autonomic function and compared with 48 control subjects. Inflammatory markers and carotid intima-media thickness were also assessed. RESULTS: Autonomic parameters of heart rate response to deep breathing and Valsalva ratio were significantly lower in the patient group. Cardiovascular autonomic impairment was generally mild with relative sparing of the efferent cardiovagal pathway. By univariate and multivariate analyses, the time after radiotherapy and C-reactive protein level were significantly associated with the degree of cardiovascular autonomic dysfunction. CONCLUSIONS: Radiation-induced cardiovascular autonomic impairment is a dynamic and progressive process that occurs long after radiotherapy. Chronic inflammation plays a major role in this process.

Equilibrium radionuclide ventriculography in the assessment of cardiotoxicity of chemotherapy and chemoradiotherapy in patients with breast cancer.

BACKGROUND: Multidrug chemotherapy increases the efficacy of the treatment, but at the same time rises its cardiotoxicity. The majority of cardiac complications are caused by anthracyclines.Radiation therapy may intensify cardiotoxicity. The aim of this study was to determine early changes of cardiac function using radionuclide ventriculography in patients with breast cancer and to compare the toxicity of AC and AT chemotherapy programs. MATERIAL AND METHODS: The study included 71 patients with breast cancer between the ages of 38 and 71 years. All patients after surgery were qualified for chemotherapy, and for 37 (52%) of them subsequent irradiation treatment was planned.Patients received chemotherapy according to the scheme: AC- 47 patients (66%) and AT - 24 patients (34%). Patients were irradiated using a photon beam (4 to 6 MeV) and an electron beam (6-15 MeV). In all patients, before and six months after the treatment, radionuclide ventriculography was performed. RESULTS: In all 71 patients a reductions in left ventricular ejection fraction (EF) and in peak filling rate (PFR) as well as an increase in the end-systolic and end-diastolic volumes (ESvol,EDvol) were observed. AC chemotherapy, where cumulative anthracycline dose was higher, significantly decreased left ventricular ejection fraction and PFR and increased ESvol. AfterAT chemotherapy the EF reduction proved to be smaller. Radiotherapy did not significantly lower the value of EF as compared to the group of patients who underwent chemotherapy. CONCLUSIONS: Radionuclide ventriculography is a useful method of evaluating the cardiotoxicity of the treatment. Early indicators of myocardial damage are EF, PFR, ESvol and EDvol.AC chemotherapy, where the average cumulative dose of anthracyclines was higher, caused more cardiotoxic effects than AT chemotherapy.Applying additional radiotherapy did not significantly increase the cardiotoxicity of the treatment.

Leg heating using far infra-red radiation in patients with chronic heart failure acutely improves the hemodynamics, vascular endothelial function, and oxidative stress.

BACKGROUND: Systemic thermal therapy (STT) has been associated with beneficial effects in patients with chronic heart failure (CHF). The fact, however, that it requires a dedicated as well as spacious facility and trained personnel makes it difficult to practice in the daily care of patients with CHF. OBJECTIVE: The aim of this study was to determine whether the leg thermal therapy (LTT) has a positive impact similar to that of STT in patients with CHF. Methods and Results Twenty patients with CHF (57 ± 17 years old, left ventricular ejection fraction=30 ± 10%) received LTT (45°C) for 20 minutes. Immediately after the treatment, the core temperature had increased (+0.3 ± 0.3°C) (p<0.01). While the LTT had no significant effects on the heart rate, systolic arterial pressure, and diastolic blood pressure, it increased the cardiac output (mixed venous oxygen saturation; +2 ± 3%) and decrease the pulmonary capillary wedge pressure (-2 ± 2 mmHg). The LTT significantly improved the flow-mediated vasodilatation (FMD) from 4.8 ± 2.6 to 7.1 ± 3.6%, the antioxidative markers, thiol from 4.0 ± 0.7 to 4.5 ± 0.9 µmoL/g, and the marker of oxidative deoxyribonucleic acid (DNA) damage, urine 8-hydroxy-2'deoxyguanosine (8OHdG) from 100 to 82 ± 3%, respectively (p<0.05). No patient had any adverse effects associated with LTT. Conclusion LTT acutely improved FMD, and oxidative stress in patients with CHF. Although the long-term effect of LTT remains to be investigated, its practicality which is comparable to that of STT would make it an attractive therapeutic strategy for patients with CHF.

A study of radiation-induced cerebral vascular injury in nasopharyngeal carcinoma patients with radiation-induced temporal lobe necrosis.

PURPOSE: To investigate radiation-induced carotid and cerebral vascular injury and its relationship with radiation-induced temporal lobe necrosis in nasopharyngeal carcinoma (NPC) patients. METHODS AND MATERIALS: Fifty eight NPC patients with radiation-induced temporal lobe necrosis (TLN) were recruited in the study. Duplex ultrasonography was used to scan bilateral carotid arterials to evaluate the intima-media thickness (IMT) and occurrence of plaque formation. Flow velocities of bilateral middle cerebral arteries (MCAs), internal carotid arteries (ICAs) and basal artery (BA) were estimated through Transcranial Color Doppler (TCD). The results were compared with data from 33 patients who were free from radiation-induced temporal lobe necrosis after radiotherapy and 29 healthy individuals. RESULTS: Significant differences in IMT, occurrence of plaques of ICAs and flow velocities of both MCAs and ICAs were found between patients after radiotherapy and healthy individuals (p<0.05). IMT had positive correlation with post radiation interval (p = 0.049). Compared with results from patients without radiation-induced TLN, the mean IMT was significantly thicker in patients with TLN (p<0.001). Plaques were more common in patients with TLN than patients without TLN (p = 0.038). In addition, flow velocities of MCAs and ICAs in patients with TLN were much faster (p<0.001, p<0.001). Among patients with unilateral TLN, flow velocity of MCAs was significantly different between ipsilateral and contralateral sides to the lesion (p = 0.001). CONCLUSION: Thickening of IMT, occurrence of plaque formation and hemodynamic abnormality are more common in patients after radiotherapy, especially in those with TLN, compared with healthy individuals.

Local hemodynamic effects of radiation on the rabbit orbitozygomatic complex with and without cytoprotection.

BACKGROUND: The authors have previously demonstrated that radiation-induced craniofacial bone growth inhibition may be ameliorated using the known cytoprotectant amifostine in the infant rabbit orbitozygomatic complex. The authors' hypothesis is that reduction in blood supply plays an important role in inhibiting craniofacial bone growth following radiotherapy and that cytoprotective pretreatment exerts its protective effect by maintaining blood supply. METHODS: Seven-week-old New Zealand male infant rabbits underwent single-dose orthovoltage irradiation to the right orbitozygomatic complex using established protocols: 0 Gy (sham), 35 Gy, and 35 Gy following pretreatment with amifostine (300 mg/kg administered intravenously). Blood flow to the orbitozygomatic complex, orbitozygomatic complex periosteum, masseter, hemimandible, and overlying skin was measured 1, 14, and 63 days after irradiation, using the modified 15-µm radioactive microsphere technique (n = 18 per group, n = 6 per time point). Orbitozygomatic complex bone specimens were harvested for blood vessel morphometry using safranin O stains at days 1 and 100 after irradiation (n = 20 per group, n = 10 per time point). RESULTS: Blood flow to the irradiated orbitozygomatic complex was significantly (p < 0.05) greater 1 day after single-dose orthovoltage irradiation compared with nonirradiated controls. This increase was not observed in the amifostine-pretreated animals and was also not seen 14 and 63 days after irradiation. No histomorphometric vessel changes were detected at any time point after irradiation in this study. CONCLUSIONS: Single-dose orthovoltage irradiation results in a temporary elevation in regional blood flow to the orbitozygomatic complex, returning to control levels within 14 days. Although pretreatment with amifostine attenuates this response, radiation-induced craniofacial bone growth inhibition in this model does not appear to be secondary to hemodynamic alterations.

Vascular injury in cancer survivors.

With an increase in the number of patients surviving many years following successful cancer treatment, has come an improved understanding of the long-term effects of cancer therapy and its implications on future health. Premature cardiovascular disease is a significant cause of early morbidity and the leading non-cancer cause of death in this population. Chemotherapeutic agents and radiation therapy are known to be cardiotoxic. However, numerous vascular-related toxicities have also been observed among cancer survivors, such as myocardial ischemia, transient ischemic attacks, and stroke, suggesting a degree of chronic endothelial injury and dysfunction leading to premature atherosclerotic disease. Vascular health in cancer survivors may be further compromised by metabolic abnormalities such as obesity, insulin resistance, and dyslipidemias which have also been reported following cancer therapy. Furthermore, some survivors experience gonadal dysfunction and loss of potentially protective sex steroids or undergo hormonal therapies that induce additional metabolic abnormalities. The effects of cancer therapies upon the endothelial monolayer have not been fully explored. An understanding of potential injury to and dysfunction of the circulatory system among cancer survivors is essential for identifying preventive strategies and therapeutic targets.