| Related Articles |
Toxicological and epidemiological studies on effects of airborne fibers: Coherence and pubic health implications.
Crit Rev Toxicol. 2014 Sep;44(8):643-95
Authors: Lippmann M
Abstract
Abstract Airborne fibers, when sufficiently biopersistent, can cause chronic pleural diseases, as well as excess pulmonary fibrosis and lung cancers. Mesothelioma and pleural plaques are caused by biopersistent fibers thinner than ∼0.1 μm and longer than ∼5 μm. Excess lung cancer and pulmonary fibrosis are caused by biopersistent fibers that are longer than ∼20 μm. While biopersistence varies with fiber type, all amphibole and erionite fibers are sufficiently biopersistent to cause pathogenic effects, while the greater in vivo solubility of chrysotile fibers makes them somewhat less causal for the lung diseases, and much less causal for the pleural diseases. Most synthetic vitreous fibers are more soluble in vivo than chrysotile, and pose little, if any, health pulmonary or pleural health risk, but some specialty SVFs were sufficiently biopersistent to cause pathogenic effects in animal studies. My conclusions are based on the following: 1) epidemiologic studies that specified the origin of the fibers by type, and especially those that identified their fiber length and diameter distributions; 2) laboratory-based toxicologic studies involving fiber size characterization and/or dissolution rates and long-term observation of biological responses; and 3) the largely coherent findings of the epidemiology and the toxicology. The strong dependence of effects on fiber diameter, length, and biopersistence makes reliable routine quantitative exposure and risk assessment impractical in some cases, since it would require transmission electronic microscopic examination, of representative membrane filter samples, for determining statistically sufficient numbers of fibers longer than 5 and 20 μm, and those thinner than 0.1 μm, based on the fiber types.
PMID: 25168068 [PubMed - in process]
| Related Articles |
Rapid real-time PCR for detection of Mycobacterium tuberculosis complex DNA in formalin-fixed paraffin embedded tissues: 16% of histological 'sarcoid' may contain such DNA.
J Clin Pathol. 2014 Aug 28;
Authors: Surat G, Wallace WA, Laurenson IF, Seagar AL
Abstract
AIMS: To investigate the diagnostic accuracy of IS6110 real-time PCR for detection of Mycobacterium tuberculosis complex (MTBC) in DNA extracted from formalin-fixed paraffin embedded (FFPE) tissues using two different methods. In the absence of material submitted for tuberculosis (TB) culture, MTBC detection in FFPE tissue can be an important aid to diagnosis.
METHODS: We collected 144 FFPE tissue blocks (lung and lymph node) for IS6110 real-time PCR. Two DNA extraction methods (QIAamp FFPE tissue kit and NucliSENS easyMAG) were assessed within a general laboratory setting. PCR results were compared with histology and culture.
RESULTS: In the histological MTBC and culture MTBC (TB-positive) groups, 72.4% were IS6110-positive and 27.6% negative. IS6110-negative results were obtained from 98%, 61.5% and 84% of the histologically MTBC-negative (TB-negative) group, histologically TB/no culture group and sarcoidosis group, respectively. Review of 19 IS6110-positive patients in the latter three groups showed that 15 had clinical TB. Thirteen of 15 (86.7%) IS6110-positive patients in the histological TB/no culture group and 2 of 4 (50%) IS6110-positive patients in the sarcoidosis group were clinically diagnosed with TB which highlights the difficulty of a pathological diagnosis.
CONCLUSIONS: IS6110 real-time PCR using easyMAG extracted DNA is a moderately sensitive, specific and rapid method for MTBC detection in FFPE material, but must be interpreted in the overall clinical context. PCR results can be available in around 5 h from FFPE specimen receipt, with minimal hands-on time.
PMID: 25170093 [PubMed - as supplied by publisher]