Jesús López Serrano

Activity of doxorubicin and cisplatin combination chemotherapy in patients with diffuse malignant pleural mesothelioma. An italian lung cancer task force (FONICAP) phase II study

Twenty‐six symptomatic patients with diffuse malignant pleural mesothelioma (DMPM) were enrolled in a Phase II Italian Lung Cancer Task Force (FONICAP) study to assess the activity and toxicity of doxorubicin and cisplatin combination chemotherapy. The drug schedule was as follows: 60 mg/m2 of doxorubicin and 60 mg/m2 of cisplatin both given intravenously (IV) on day 1 every 3 to 4 weeks. Of the 24 evaluable patients, 6 objective partial responses (25%; 95% confidence limits, 9.77% to 46.71%) were observed. Twelve of 24 patients (50%), including 6 with no radiologic evidence of response, had a clinical improvement as demonstrated by an objective reduction of symptom or performance status scores along treatment. The overall median survival time was 10 months. Toxicity was mild and dose reductions or suspensions were not required. The combination of doxorubicin and cisplatin is effective and well tolerated. It might be considered for palliation of symptomatic patients with DMPM.

In vitro biological effects of airborne PM2.5 and PM10 from a semi-desert city on the Mexico–US border

Compelling evidence indicates that exposure to urban airborne particulate matter (PM) affects health. However, how PM components interact with PM-size to cause adverse health effects needs elucidation, especially when considering soil and anthropogenic sources. We studied PM from Mexicali, Mexico, where soil particles contribute importantly to air pollution, expecting to differentiate in vitro effects related to PM-size and composition. PM samples with mean aerodynamic diameters ≤2.5μm (PM(2.5)) and ≤10μm (PM(10)) were collected in Mexicali (October 2005-March 2006) from a semi-urban (expected larger participation of soil sources) and an urban (predominately combustion sources) site. Samples were pooled by site and size, analyzed for elemental composition (particle-induced X-ray emission) and tested in vitro for: induction of human erythrocytes membrane disruption (hemolysis) (colorimetrically); inhibition of cell proliferation (ICP) (crystal violet) and TNFα/IL-6 secretion (ELISA) using J774.A1 murine monocytic cells; and DNA degradation using Balb/c3T3 cell naked DNA (electrophoretically). Results of PM elemental composition principal component analysis were used in associating cellular effects. Sixteen elements identified in PM grouped in two principal components: Component(1) (C(1)): Mg, Al, Si, P, Cl, K, Ca, Ti, V, Cr, Fe, and Component(2) (C(2)): Cu, Zn. Hemolysis was predominately induced by semi-urban-PM(10) (p<0.05) and was associated with urban-PM(10)C(1) (r=0.62, p=0.003). Major ICP resulted with semi-urban PM(2.5) (p<0.05). TNFα was mainly induced by urban samples regardless of size (p<0.05) and associated with urban-PM(2.5)C(2) (r=0.48, p=0.02). Both PM(10) samples induced highest DNA degradation (p<0.05), regardless of location. We conclude that PM-size and PM-related soil or anthropogenic elements trigger specific biological-response patterns.

Variation in the composition and in vitro proinflammatory effect of urban particulate matter from different sites.

Spatial variation in particulate matter–related health and toxicological outcomes is partly due to its composition. We studied spatial variability in particle composition and induced cellular responses in Mexico City to complement an ongoing epidemiologic study. We measured elements, endotoxins, and polycyclic aromatic hydrocarbons in two particle size fractions collected in five sites. We compared the in vitro proinflammatory response of J774A.1 and THP‐1 cells after exposure to particles, measuring subsequent TNFα and IL‐6 secretion. Particle composition varied by site and size. Particle constituents were subjected to principal component analysis, identifying three components: C1 (Si, Sr, Mg, Ca, Al, Fe, Mn, endotoxin), C2 (polycyclic aromatic hydrocarbons), and C3 (Zn, S, Sb, Ni, Cu, Pb). Induced TNFα levels were higher and more heterogeneous than IL‐6 levels. Cytokines produced by both cell lines only correlated with C1, suggesting that constituents associated with soil induced the inflammatory response and explain observed spatial differences.

The oxidative potential and biological effects induced by PM10 obtained in Mexico City and at a receptor site during the MILAGRO Campaign

As part of a field campaign that studied the impact of Mexico City pollution plume at the local, sub-regional and regional levels, we studied transport-related changes in PM(10) composition, oxidative potential and in vitro toxicological patterns (hemolysis, DNA degradation). We collected PM(10) in Mexico City (T(0)) and at a suburban-receptor site (T(1)), pooled according to two observed ventilation patterns (T(0) → T(1) influence and non-influence). T(0) samples contained more Cu, Zn, and carbon whereas; T(1) samples contained more of Al, Si, P, S, and K (p < 0.05). Only SO(4)(-2) increased in T(1) during the influence periods. Oxidative potential correlated with Cu/Zn content (r = 0.74; p < 0.05) but not with biological effects. T(1) PM(10) induced greater hemolysis and T(0) PM(10) induced greater DNA degradation. Influence/non-influence did not affect oxidative potential nor biological effects. Results indicate that ventilation patterns had little effect on intrinsic PM(10) composition and toxicological potential, which suggests a significant involvement of local sources.

Particulate matter promotes in vitro receptor-recognizable low-density lipoprotein oxidation and dysfunction of lipid receptors.

Particulate matter may promote cardiovascular disease, possibly as a consequence of its oxidative potential. Studies using susceptible animals indicate that particulate matter aggravates atherosclerosis by increasing lipid/macrophage content in plaques. Macrophage lipid uptake requires oxidized low‐density lipoprotein and scavenger receptors; same receptors are involved in particulate matter uptake. We studied in vitro particulate matter potential to oxidize low‐density lipoproteins and subsequent cell uptake through scavenger receptors. Particulate matter‐induced low‐density lipoproteins oxidation was evaluated by the thiobarbituric acid assay. Binding/internalization was tested in wild type and scavenger receptor–transfected Chinese hamster ovary cells, and in RAW264.7 cells using fluorescently labeled low‐density lipoproteins. Dose‐dependent binding/internalization only occurred in scavenger receptor–transfected Chinese hamster ovary cells and RAW264.7 cells. Competition binding/internalization using particles showed that particulate matter induced decreased binding (∼50%) and internalization (∼70%) of particle‐oxidized low‐density lipoproteins and native low‐density lipoproteins. Results indicate that particulate matter was capable of oxidizing low‐density lipoproteins, favoring macrophage internalization, and also altered scavenger and low‐density lipoproteins receptor function.