HLA class I alterations in breast carcinoma are associated with a high frequency of the loss of heterozygosity at chromosomes 6 and 15.

HLA class I (HLA-I) molecules play a crucial role in the presentation of tumor antigenic peptides to CD8+ T cells. Tumor HLA-I loss provides a route of immune escape from T cell-mediated killing. We analyzed HLA-I expression in 98 cryopreserved breast cancer tissues using a broad panel of anti-HLA-I antibodies. Genomic HLA-I typing was performed using DNA obtained from autologous normal breast tissue. Analysis of the loss of heterozygosity (LOH) in the HLA-I region of chromosome 6 (LOH-6) and in the ß2-microglobulin (B2M) region of chromosome 15 (LOH-15) was done by microsatellite amplification of DNA isolated from microdissected tumor areas. B2M gene sequencing was done using this DNA form HLA-I-negative tumors. Immunohistological analysis revealed various types of HLA-I alterations in 79 tumors (81%), including total HLA-I loss in 53 cases (54%) and partial loss in 16 samples (14%). In 19 cases (19%), HLA-I expression was positive. Using microsatellite analysis, we detected LOH in 36 cases out of 92 evaluated (39%), including 15 samples with only LOH-6, 14 with LOH-15, and seven tumors with LOH-6 and LOH-15 at the same time. Remarkably, we detected LOH-6 in eight tumors with positive HLA-I immunolabeling. We did not find any B2M mutations in HLA-I-negative breast tumors. In conclusion, LOH at chromosomes 6 and 15 has a high incidence in breast cancer and occurs in tumors with different HLA-I immunophenotypes. This common molecular mechanism of HLA-I alterations may reduce the ability of cytotoxic T lymphocytes  to kill tumor cells and negatively influence the clinical success of cancer immunotherapy.

Pollutant emissions from the pyrolysis and combustion of viscoelastic memory foam.

Thermal degradation of viscoelastic memory foam (VMF) in a horizontal laboratory scale reactor has been studied. Pyrolysis and combustion experiments under sub-stoichiometric conditions were performed at four different temperatures (550°C, 650°C, 750°C and 850°C) for the determination of pollutants. Analyses of gas and semivolatile compounds, including polychlorodibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) are shown. From the results, it was deduced that pyrolytic conditions favor the formation of PAHs, methane, ethylene, NH3 and dl-PCBs, whereas the presence of oxygen involves a higher emission of PCDD/Fs and simple N-containing compounds such as NO and HCN. The toxic levels calculated for PAHs, PCDD/Fs and dl-PCBs in all cases were low confirming that the incineration of VMF mattress waste could be a good option for waste management. Nevertheless, relatively high emissions of NO, NH3 and HCN were obtained and their reduction must be considered.

Isocyanate emissions from pyrolysis of mattresses containing polyurethane foam.

This study examined the emissions of powerful asthmatic agents called isocyanates from small-scale pyrolysis experiments of two common foams employed in mattress production such as flexible polyurethane foam (FPUF) and viscoelastic memory foam (VMF). A nitrogen atmosphere and five different temperatures, 300, 350, 400, 450 and 850 °C, were selected to carry out the experiments in order to evaluate the worst possible conditions for thermal degradation. A similar trend for both materials was found. At lower temperatures, diisocyanates were the most important products whereas at 850 °C monoisocyanates, and mainly isocyanic acid released mainly from the thermal cracking of diisocyanates evolved directly from the polymer chains. The total yields of isocyanates were in the range of 1.43-11.95 mg/m3 for FPUF at 300-850 °C and 0.05-6.13 mg/m3 for VMF, 300-850 °C. This difference could be a consequence of the lower amount of isocyanates employed in the VMF production which was confirmed by the nitrogen content of the foams, 5.95% FPUF vs. 3.34% in VMF. Additionally, a qualitative search for so far unknown isocyanates was performed in samples from the pyrolysis of FPUF at 300, 400 and 850 °C. It was confirmed that six different aminoisocyanates at 300 °C were evolved, whereas at 400 and 850 °C only five of them were detected. The general trend observed was a decrease of the aminoisocyanate levels with increasing pyrolysis temperature.

Pollutant formation in the pyrolysis and combustion of Automotive Shredder Residue.

The present work has been carried out to verify the feasibility of thermal valorization of an automobile shredder residue (ASR). With this aim, the thermal decomposition of this waste has been studied in a laboratory scale reactor, analyzing the pollutants emitted under different operating conditions. The emission factors of carbon oxides, light hydrocarbons, PAHs, PCPhs, PCBzs, PBPhs, PCDD/Fs, dioxin-like PCBs and PBDD/Fs were determined at two temperatures, 600 and 850°C, and under different oxygen ratios ranging from 0 (pure pyrolysis) to 1.5 (over-stoichiometric oxidation). After analyzing all these compounds, we conclude that thermal valorization of ASR is a clean way to treat this waste.

Pollutant emissions during the pyrolysis and combustion of flexible polyurethane foam.

Thermal decomposition of flexible polyurethane foam (FPUF) was studied under nitrogen and air atmospheres at 550°C and 850°C using a laboratory scale reactor to analyse the evolved products. Ammonia, hydrogen cyanide and nitrile compounds were obtained in high yields in pyrolysis at the lower temperature, whereas at 850°C polycyclic aromatic hydrocarbons (PAHs) and other semivolatile compounds, especially compounds containing nitrogen (benzonitrile, aniline, quinolone and indene) were the most abundant products. Different behaviour was observed in the evolution of polychlorodibenzo-p-dioxins and furans (PCDD/Fs) at 550°C and 850°C. At 550°C, the less chlorinated congeners, mainly PCDF, were more abundant. Contrarily, at 850°C the most chlorinated PCDD were dominant. In addition, the total yields of PCDD/Fs in the pyrolysis and combustion runs at 850°C were low and quite similar.

Activity of hepatic enzymes from week sixteen of pregnancy.

OBJECTIVE: This study was undertaken to determine the prevalence, epidemiology, and mother-child repercussions of increased alanine-aminotransferase levels from week 16 of pregnancy. STUDY DESIGN: A longitudinal observational study of 381 pregnant women. The cause of increased alanine-aminotransferase levels during pregnancy and repercussions on the neonate were studied in 283 cases. Statistical analysis was performed with Mann-Whitney test, chi2 test, or the Fisher exact test. RESULTS: The mean age of the mothers was 29.9 +/- 4.8 years. Twenty-five percent presented increased gamma-glutamyl-transpeptidase, alkaline phophatase, and dehydrogenase lactate from week 32. Increased alanine-aminotransferase was observed in 7.4% (95% CI, 5.00%-10.57%) of cases. Clinical disorders were light, transitory, and with no apparent cause, except for 1 hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome, 3 preeclampsias, and 1 gravidic cholestasis. No statistically significant differences were observed in the group of mother-child with alanine-aminotransferase normal or increased. CONCLUSION: Most increases in alanine-aminotransferase from week 16 of pregnancy are transitory, non-specific, and have no repercussions on mother or child.