Low-Frequency (20 kHz) Ultrasonic Modulation of Drug Action.

We tested the effect of low-frequency ultrasound (LUS, 20 kHz, 4 W/cm2) on the function of rat mesentery and human pulmonary arteries with wire myography. The vessels were induced to contract with either noradrenaline or physiologic saline solution (PSS) with a high potassium concentration (KPSS) and then incubated with capsaicin (2.1 × 10-7 M, TRPV1 [transient receptor potential vanilloid 1] activator), dopamine (1 × 10-4 M, dopamine and α2-receptor activator), or fenoldopam (dopamineA1 receptor agonist, 1 × 10-4 M) with and without glibenclamide (1 µM, KATP [adenosine triphosphate {sensitive potassium channel (ATP)}-sensitive potassium channel] inhibitor and α2-receptor modulator), and insonated. Vessels were incubated in Ca2+-free PSS and induced to contract with added extracellular Ca2+ and noradrenaline. Pulmonary arteries were induced to contract with KPSS and dopamine. Then the vessels were insonated. LUS inhibited the influx of external Ca2+, inhibited the dopamine-induced vasoconstriction in the KPSS (glibenclamide reversible), reduced the capsaicin-induced vasorelaxation, increased the gentamicin-induced vasorelaxation and increased the dopamine-induced contraction in the KPSS in human pulmonary arteries.

Illustration of a fatal radiation-induced lung aneurysm: Is central lung stereotactic radiotherapy to be banned?

Stereotactic body radiation therapy is still controversial for inoperable patients with central lung lesion. We report the case of a 59-year-old woman with previous history of head and neck squamous cell carcinoma who was treated by lung stereotactic body irradiation for an inoperable lymph node in station 10R. One year after, a fibroscopy showed a necrosis of the right main bronchus mucosae and the CT showed a radio-induced aneurysm protruding into the right inferior lobular bronchus. The patient eventually died a few hours later with a massive haemoptysis. This case highlights the potential toxicity of central lung stereotactic body radiation therapy and raises the question of its legitimacy.

Comparison of different registration landmarks for MRI-CT fusion in radiotherapy for lung cancer with post-obstructive lobar collapse.

The registration of the two sets of images based on the spine and pulmonary artery landmarks and the geometric center difference of the mean displacement in the X, Y, and Z directions (X, Y, and Z represent the directions of the body from left to right, superior to inferior, and anterior to posterior) between their MRI-CT fusions were compared, respectively. Fifty-five lung cancer patients with post-obstructive lobar collapse were enrolled in this study. Before radiation, two sets of simulating images according to the spine and the pulmonary artery registrations were obtained for each patient using MRI-CT fusion. The differences of mean displacement in the X, Y, and Z directions based on spine and pulmonary artery landmarks were of -0.29, 0.25, and 0.18 cm, respectively. The mean displacements of the pulmonary artery based images in the three directions were smaller than that in the spine registration images (P < 0.05). By the method of pulmonary artery landmark, MRI-CT has better registration accuracy and can better help confirm the target volume.

Opsin 3 and 4 mediate light-induced pulmonary vasorelaxation that is potentiated by G protein-coupled receptor kinase 2 inhibition.

We recently demonstrated that blue light induces vasorelaxation in the systemic mouse circulation, a phenomenon mediated by the nonvisual G protein-coupled receptor melanopsin (Opsin 4; Opn4). Here we tested the hypothesis that nonvisual opsins mediate photorelaxation in the pulmonary circulation. We discovered Opsin 3 (Opn3), Opn4, and G protein-coupled receptor kinase 2 (GRK2) in rat pulmonary arteries (PAs) and in pulmonary arterial smooth muscle cells (PASMCs), where the opsins interact directly with GRK2, as demonstrated with a proximity ligation assay. Light elicited an intensity-dependent relaxation of PAs preconstricted with phenylephrine (PE), with a maximum response between 400 and 460 nm (blue light). Wavelength-specific photorelaxation was attenuated in PAs from Opn4-/- mice and further reduced following shRNA-mediated knockdown of Opn3. Inhibition of GRK2 amplified the response and prevented physiological desensitization to repeated light exposure. Blue light also prevented PE-induced constriction in isolated PAs, decreased basal tone, ablated PE-induced single-cell contraction of PASMCs, and reversed PE-induced depolarization in PASMCs when GRK2 was inhibited. The photorelaxation response was modulated by soluble guanylyl cyclase but not by protein kinase G or nitric oxide. Most importantly, blue light induced significant vasorelaxation of PAs from rats with chronic pulmonary hypertension and effectively lowered pulmonary arterial pressure in isolated intact perfused rat lungs subjected to acute hypoxia. These findings show that functional Opn3 and Opn4 in PAs represent an endogenous "optogenetic system" that mediates photorelaxation in the pulmonary vasculature. Phototherapy in conjunction with GRK2 inhibition could therefore provide an alternative treatment strategy for pulmonary vasoconstrictive disorders.

Diagnóstico prenatal de origen anómalo de arteria pulmonar derecha / Prenatal diagnosis of anomalous origin of the right pulmonary artery

No disponible

Effect of high laser output on the central bronchi and pulmonary artery.

A diode-pump Nd:YAG high-power laser (wavelength 1320 nm, power 100 W) is routinely used to surgically remove lung metastases. Even pulmonary lesions in central locations are resectable via this method, yet it also carries a potential risk of damaging the larger bronchi and vessels in the vicinity. Studies investigating the safety of using high-power lasers are lacking. We therefore aimed to examine the direct effects of a 100-watt laser on the bronchi and pulmonary artery at a standard working velocity. From freshly slaughtered pigs, we isolated cylindrical specimens of the trachea, the main and lobar bronchi, and the central pulmonary artery from the both lungs. These specimens were fixed consecutively in rows behind each other on a Styrofoam surface in the laboratory. The laser's handle was clamped into a hydraulic feed unit so that the laser was focused at constant distance perpendicular to the tissue and would move at 10 mm/s over the specimens. The Nd:YAG Laser LIMAX® 120 functioned at a consistent power of 100 W during all the experiments. The lasered specimens were examined macroscopically and histologically for tissue damage. None of the trachea or bronchial walls were perforated. Compared to the pulmonary parenchyma, we observed no vaporization effects-only minor superficial coagulation (with a mean depth of 2.1 ± 0.8 mm). This finding was histologically confirmed in each specimen, which revealed mild superficial coagulation and no damage to the cartilage. In the presence of a residual peribronchial fatty tissue, the laser effect was even attenuated. The pulmonary arteries presented no lumen openings whatsoever, merely a discrete trace of coagulation. The vessel wall revealed increased vacuolization without alteration of the remaining vessel wall. In conclusion, laser resection at 100 W of the central lung areas is safe with respect to airways and blood vessels and the laser output does not need to be reduced when treating these areas.

Is pulmonary artery a dose-limiting organ at risk in non-small cell lung cancer patients treated with definitive radiotherapy?

PURPOSE: Our previous study suggested that some pulmonary artery (PA) dosimetric parameters were associated with mortality in unresectable non-small cell lung cancer (NSCLC) treated with definitive radiotherapy. The present study aims to analyze the impact of both PA and heart dosimetric parameters on survival of patients with NSCLC treated with definitive conventional fractionated radiotherapy (CFRT) in another independent research center and further determine whether the PA should be considered a dose-limiting organ at risk (OAR) for patients receiving thoracic CFRT. METHODS: We performed a retrospective analysis of successive patients with medically inoperable or unresectable NSCLC treated with definitive radiotherapy or chemoradiotherapy from August 2010 to September 2014. Clinical and pathological information, PA and heart dosimetric factors, and follow-up data were collected from each patient's records and evaluated as potential prognostic factors for survival. Survival probabilities were estimated by the Kaplan-Meier method and compared by the log rank test. Cox proportional hazards regression models were performed to determine the independent predicators of survival. The optimal cutoff points of continuous dosimetric variables were determined by Youden index in receiver operating characteristic (ROC) analysis. RESULTS: This study analyzed the records of 141 patients, 50.4% had adenocarcinoma, 71.6% had stage III disease, and 55% patients received concurrent chemoradiotherapy. Radiation dose ranged from 60 to 76 Gy in 30-38 fractions. Median follow up was 16.9 months. Median overall survival (OS) was 20.5 months (95% confidence interval [CI] 10.3-30.7 months), and 1-, 2-, 3-year OS rates were 75.2%, 58.2% and 56%, respectively. Univariate and multivariate analysis showed that Karnofsky Performance Status (KPS) score, Charlson's Comorbidity Index (CCI), T and N stage, PA invasion grade and the percentage of PA volume that received 40 to 55 Gy (PA V40-55) were significantly associated with OS. No significant associations were found between heart dosimetric factors and OS. Median OS of patients with PA invasion grade 0, 1, 2, and 3 were 41.8, 27.8, 12.7 and 7.5 months, respectively (P < 0.001). PA V40, V45, V50 and V55, using thresholds of 80%, 68%, 45%, and 32%, respectively, were independent predictors for OS. CONCLUSIONS: PA invasion grade and PA V40-55 appear associated with OS in patients with NSCLC treated with definitive CFRT. We propose that PA be considered as a dose-limiting OAR for such patients.

Pulmonary artery invasion, high-dose radiation, and overall survival in patients with non-small cell lung cancer.

PURPOSE: To investigate whether high-dose radiation to the pulmonary artery (PA) affects overall survival (OS) in patients with non-small cell lung cancer (NSCLC). METHODS AND MATERIALS: Patients with medically inoperable/unresectable NSCLC treated with definitive radiation therapy in prospective studies were eligible for this study. Pulmonary artery involvement was defined on the basis of pretreatment chest CT and positron emission tomography/CT fusion. Pulmonary artery was contoured according to the Radiation Therapy Oncology Group protocol 1106 atlas, and dose-volume histograms were generated. RESULTS: A total of 100 patients with a minimum follow-up of 1 year for surviving patients were enrolled: 82.0% underwent concurrent chemoradiation therapy. Radiation dose ranged from 60 to 85.5 Gy in 30-37 fractions. Patients with PA invasion of grade ≤2, 3, 4, and 5 had 1-year OS and median survival of 67% and 25.4 months (95% confidence interval [CI] 15.7-35.1), 62% and 22.2 months (95% CI 5.8-38.6), 90% and 35.8 months (95% CI 28.4-43.2), and 50% and 7.0 months, respectively (P=.601). Two of the 4 patients with grade 5 PA invasion died suddenly from massive hemorrhage at 3 and 4.5 months after completion of radiation therapy. Maximum and mean doses to PA were not significantly associated with OS. The V45, V50, V55, and V60 of PA were correlated significantly with a worse OS (P<.05). Patients with V45 >70% or V60 >37% had significantly worse OS (13.3 vs 37.9 months, P<.001, and 13.8 vs 37.9 months, P=.04, respectively). CONCLUSIONS: Grade 5 PA invasion and PA volume receiving more than 45-60 Gy may be associated with inferior OS in patients with advanced NSCLC treated with concurrent chemoradiation.

Lung irradiation induces pulmonary vascular remodelling resembling pulmonary arterial hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a commonly fatal pulmonary vascular disease that is often diagnosed late and is characterised by a progressive rise in pulmonary vascular resistance resulting from typical vascular remodelling. Recent data suggest that vascular damage plays an important role in the development of radiation-induced pulmonary toxicity. Therefore, the authors investigated whether irradiation of the lung also induces pulmonary hypertension. METHODS: Different sub-volumes of the rat lung were irradiated with protons known to induce different levels of pulmonary vascular damage. RESULTS: Early loss of endothelial cells and vascular oedema were observed in the irradiation field and in shielded parts of the lung, even before the onset of clinical symptoms. 8 weeks after irradiation, irradiated volume-dependent vascular remodelling was observed, correlating perfectly with pulmonary artery pressure, right ventricle hypertrophy and pulmonary dysfunction. CONCLUSIONS: The findings indicate that partial lung irradiation induces pulmonary vascular remodelling resulting from acute pulmonary endothelial cell loss and consequential pulmonary hypertension. Moreover, the close resemblance of the observed vascular remodelling with vascular lesions in PAH makes partial lung irradiation a promising new model for studying PAH.

The effect of a contrast agent on proton beam range in radiotherapy planning using computed tomography for patients with locoregionally advanced lung cancer.

PURPOSE: We evaluated the effect of a contrast agent (CA) on proton beam range in a treatment planning system (TPS) for patients with locoregionally advanced lung cancer. METHODS AND MATERIALS: Two sets of computed tomography (CT) images (with and without CA) were obtained from 20 patients with lung cancer. Because the increase in Hounsfield unit (∆HU) value of the heart and great vessels due to the effect of CA is most prominent among thoracic structures, to evaluate the effect of CA on proton beam range in the TPS, we compared the calculated distal ranges in the plan with CA-enhanced CT with those with corrected CT, in which the HU values of the heart and great vessels in the CA-enhanced CT were replaced by average HU values obtained from the unenhanced CT. RESULTS: The mean ∆HU value and the longest length of the heart and great vessels within the proton beam path in the field that passed through these structures were 189 ± 29 HU (range, 110-250 HU) and 7.1 ± 1.1 cm (range, 2.6-11.2 cm), respectively. The mean distal range error in the TPS because of the presence of CA was 1.0 ± 0.7 cm (range, 0.2-2.6 cm). CONCLUSION: If CA-enhanced CT images are used for radiotherapy planning using a proton beam for the treatment of lung cancer, our results suggest that the HU values of the heart and great vessels should be replaced by the average HU values of soft tissue to avoid discrepancies between planned and delivered doses.

Manganese superoxide dismutase is not protective in bovine pulmonary artery endothelial cells at systemic oxygen levels.

Bovine pulmonary artery endothelial cells (BPAEC) are extremely sensitive to oxygen, mediated by superoxide production. Ionizing radiation is known to generate superoxide in oxygenated aqueous media; however, at systemic oxygen levels (3%), no oxygen enhancement is observed after irradiation. A number of markers (cell growth, alamarBlue, mitochondrial membrane polarization) for metabolic activity indicate that BPAEC maintained under 20% oxygen grow and metabolize more slowly than cells maintained under 3% oxygen. BPAEC cultured in 20% oxygen grow better when they are transiently transfected with either manganese superoxide dismutase (MnSOD) or copper zinc superoxide dismutase (CuZnSOD) and exhibit improved survival after irradiation (0.5-10 Gy). Furthermore, X irradiation of BPAEC grown in 20% oxygen results in very diffuse colony formation, which is completely ameliorated by either growth in 3% oxygen or overexpression of MnSOD. However, MnSOD overexpression in BPAEC grown in 3% oxygen provides no further radioprotection, as judged by clonogenic survival curves. Radiation does not increase apoptosis in BPAEC but inhibits cell growth and up-regulates p53 and p21 at either 3% or 20% oxygen.

Renin-Angiotensin system suppression mitigates experimental radiation pneumonitis.

PURPOSE: To find the mitigators of pneumonitis induced by moderate doses of thoracic radiation (10-15 Gy). METHODS AND MATERIALS: Unanesthetized WAG/RijCmcr female rats received a single dose of X-irradiation (10, 12, or 15 Gy at 1.615 Gy/min) to the thorax. Captopril (an angiotensin-converting enzyme inhibitor) or losartan (an angiotensin receptor blocker) was administered in the drinking water after irradiation. Pulmonary structure and function were assessed after 8 weeks in randomly selected rats by evaluating the breathing rate, ex vivo vascular reactivity, and histopathologic findings. Survival analysis was undertaken on all animals, except those scheduled for death. RESULTS: Survival after a dose of 10 Gy to the thorax was not different from that of unirradiated rats for

Vascular injury after whole thoracic x-ray irradiation in the rat.

PURPOSE: To study vascular injury after whole thoracic irradiation with single sublethal doses of X-rays in the rat and to develop markers that might predict the severity of injury. METHODS AND MATERIALS: Rats that received 5- or 10-Gy thorax-only irradiation and age-matched controls were studied at 3 days, 2 weeks, and 1, 2, 5, and 12 months. Several pulmonary vascular parameters were evaluated, including hemodynamics, vessel density, total lung angiotensin-converting enzyme activity, and right ventricular hypertrophy. RESULTS: By 1 month, the rats in the 10-Gy group had pulmonary vascular dropout, right ventricular hypertrophy, increased pulmonary vascular resistance, increased dry lung weights, and decreases in total lung angiotensin-converting enzyme activity, as well as pulmonary artery distensibility. In contrast, irradiation with 5 Gy resulted in only a modest increase in right ventricular weight and a reduction in lung angiotensin-converting enzyme activity. CONCLUSION: In a previous investigation using the same model, we observed that recovery from radiation-induced attenuation of pulmonary vascular reactivity occurred. In the present study, we report that deterioration results in several vascular parameters for

Structural and functional alterations in the rat lung following whole thoracic irradiation with moderate doses: injury and recovery.

PURPOSE: To characterize structural and functional injuries following a single dose of whole-thorax irradiation that might be survivable after a nuclear attack/accident. METHODS: Rats were exposed to 5 or 10 Gy of X-rays to the whole thorax with other organs shielded. Non-invasive measurements of breathing rate and arterial oxygen saturation, and invasive evaluations of bronchoalveolar lavage fluid, (for total protein, Clara cell secretory protein), vascular reactivity and histology were conducted for at least 6 time points up to 52 weeks after irradiation. RESULTS: Irradiation with 10 Gy resulted in increased breathing rate, a reduction in oxygen saturation, an increase in bronchoalveolar lavage fluid protein and attenuation of vascular reactivity between 4-12 weeks after irradiation. These changes were not observed with the lower dose of 5 Gy. Histological examination revealed perivascular edema at 4-8 weeks after exposure to both doses, and mild fibrosis beyond 20 weeks after 10 Gy. CONCLUSIONS: Single-dose exposure of rat thorax to 10 but not 5 Gy X-irradiation resulted in a decrease in oxygen uptake and vasoreactivity and an increase in respiratory rate, which paralleled early pulmonary vascular pathology. Vascular edema resolved and was replaced by mild fibrosis beyond 20 weeks after exposure, while lung function recovered.

Neoadjuvant chemotherapy with reduced-dose carboplatin and gemcitabine for non-small cell lung cancer in a patient with Fanconi anemia.

Fanconi anemia (FA) is characterized by pancytopenia, congenital malformations, and susceptibility to malignancies. We describe a 31-year-old man with FA, who had undergone bone marrow transplantation and whole body irradiation at the age 17 years for FA. Fourteen years later, he presented with squamous cell carcinoma of the bronchus intermedius in the right lung. The tumor was located next to the main pulmonary artery and between the superior and inferior pulmonary veins. Two cycles of neoadjuvant therapy were given in an attempt to decrease tumor size and avoid a potential right pneumonectomy. Treatment consisted of a 21-day cycle with carboplatin (area under the curve 3) given on day 1 and gemcitabine (1250 mg/m) on day 1 and 8. Because FA cells are hypersensitive to DNA crosslinking agents, we reduced the carboplatin dose to minimize treatment-related toxicity. The tumor regressed sufficiently to permit performance of a right middle and lower lobectomy. In our case, neoadjuvant therapy with gemcitabine and low-dose carboplatin exhibited antitumor activity with manageable side-effects, suggesting that this chemotherapy regimen can be safely and effectively used in the treatment of NSCLC in FA patients who have achieved hematopoietic reconstitution after bone marrow transplantation.

Gamma irradiation induces acetylcholine-evoked, endothelium-independent relaxation and activates K-channels of isolated pulmonary artery of rats.

PURPOSE: To test the effects of irradiation (R*) on the pulmonary artery (PA). METHODS AND MATERIALS: Isolated PA rings were submitted to gamma irradiation (cesium, 8 Gy/min(-1)) at doses of 20 Gy-140 Gy. Rings were placed in an organ chamber, contracted with serotonin (10(-4) M 5-hydroxytryptamine [5-HT]), then exposed to acetylcholine (ACh) in incremental concentrations. Smooth muscle cell (SMC) membrane potential was measured with microelectrodes. RESULTS: A high dose of irradiation (60 Gy) increased 5HT contraction by 20%, whereas lower (20 Gy) doses slightly decreased it compared with control. In the absence of the endothelium, 5-HT precontracted rings exposed to 20 Gy irradiation developed a dose-dependent relaxation induced by acetylcholine (EI-ACh) with maximal relaxation of 60 +/- 17% (n = 13). This was totally blocked by L-NAME (10(-4) M), partly by 7-nitro indazole; it was abolished by hypoxia and iberiotoxin, decreased by tetra-ethyl-ammonium, and not affected by free radical scavengers. In irradiated rings, hypoxia induced a slight contraction which was never observed in control rings. No differences in SMC membrane potential were observed between irradiated and nonirradiated PA rings. CONCLUSION: Irradiation mediates endothelium independent relaxation by a mechanism involving the nitric oxide pathway and K-channels.

Radiation-induced alterations in angiotensin converting enzyme activity in cultured bovine pulmonary arterial endothelial cell monolayers.

Bovine pulmonary arterial endothelial cells (BPAE) were exposed to a single dose 0, 5, 10, 20, or 30 Gy, in culture. Angiotensin converting enzyme (ACE) activity was determined in confluent monolayers, under first-order reaction conditions, at 6, 24, 48, and 96 hr after treatment, using [3H]benzoyl-Phe-Ala-Pro as substrate. Irradiation decreased the number of viable endothelial cells in a dose- and time-dependent manner, beginning at 24 hr after 5 Gy and reaching a maximum effect (21% survival) at 96 hr after 30 Gy. Total amount of protein per monolayer decreased during the same time intervals, whereas protein content per cell rose, signifying a radiation-induced hypertrophy of viable cells. When expressed per million surviving cells, ACE activity increased in a time- and dose-dependent manner, beginning at 24 hr after 5 Gy and reaching a maximum fourfold increase at 96 hr after 30 Gy. However, when expressed per culture well, ACE activity decreased in a time- and radiation-dependent manner. These results suggest that although at the lowest radiation dose (5 Gy), the increase in ACE activity per cell compensated for the enzymatic activity lost due to extensive cell death, at higher doses (10, 20, and 30 Gy), the increase in ACE activity per cell could not keep up with the decrease in the number of viable endothelial cells, leading to an overall decrease in ACE activity per culture well.

Enhanced photorelaxation in aorta, pulmonary artery and corpus cavernosum produced by BAY K 8644 or N-nitro-L-arginine.

Segments of endothelium-denuded aorta, pulmonary arterial rings and strips of corpus cavernosum from rabbits were superfused with Krebs medium. Photorelaxation elicited by ultraviolet light (366 nm) was significantly enhanced by either BAY K 8644 (20 nM) or N-nitro-L-arginine (100 and 500 microM) and was associated with increased cyclic GMP. This action of both drugs was greater in pulmonary artery than aorta and corpus cavernosum and persisted in vascular rings for 90 min after drug removal. The effect was significantly attenuated by hemoglobin (10 microM) but was unaltered by superoxide dismutase (30 u/ml). The mechanism of such photosensitization is presently unclear.

Association of pulmonary artery photorelaxation with H2O2 metabolism by catalase.

We have examined the mechanism governing guanosine 3',5'-cyclic monophosphate (cGMP)-associated photoinduced relaxation elicited by long-wavelength ultraviolet (UV) light of endothelium-removed, isolated bovine pulmonary arteries. Hypoxia, produced by gassing of the organ bath solution with 95% N2-5% CO2, inhibited photorelaxation. Photorelaxation was also inhibited by cyanide (1 mM NaCN) but was potentiated by lactate (5 mM). Irradiation of bovine pulmonary arterial smooth muscle with UV light (or exposure to exogenous H2O2) stimulated cyanide-inhibitable oxidation of methanol to formaldehyde, suggesting that UV light increased H2O2 metabolism via catalase. The UV light-induced oxidation of methanol by pulmonary arterial smooth muscle was also inhibited by hypoxia. Consumption of O2 was detected when pulmonary arterial tissue was exposed to UV light, but cyanide failed to interfere with this effect, consistent with the photochemical reduction of O2 within vascular smooth muscle in a manner independent of mitochondrial respiration. We propose that photorelaxation is associated with the intracellular photochemical reduction of O2 to form H2O2, which elicits increases of vascular smooth muscle cGMP levels via the catalase-dependent activation of soluble guanylate cyclase. In addition, we hypothesize that the photooxidation of NAD(P)H could contribute to the generation of H2O2, since the enhancement of photorelaxation by lactate may originate from increased levels of NADH.