Adverse health effects of asbestos: solving mysteries regarding asbestos carcinogenicity based on follow-up survey of a Chinese factory

The present review summarizes the results of several follow-up studies assessing an asbestos product manufacturing plant in Chongqing, China, and discusses three controversial issues related to the carcinogenicity of asbestos. The first issue is the amphibole hypothesis, which asserts that the carcinogenicity of asbestos is limited to amphiboles, such as crocidolite, but not serpentines, such as chrysotile. However, considering the possible multiple component of asbestos carcinogenicity in the presence of tobacco smoke or other carcinogens, chrysotile cannot be regarded as non-carcinogenic. Additionally, in a practical sense, it is not possible to assume "pure" chrysotile due to its ubiquitous contamination with tremolite, which is a type of amphibole. Thus, as the International Agency for Research on Cancer (IARC) assessed, all forms of asbestos including chrysotile should be regarded carcinogenic to humans (Group 1). The second issue is the chrysotile/tremolite paradox, which is a phenomenon involving predominant levels of tremolite in the lung tissues of individuals who worked in locations with negligible levels of tremolite due to the exclusive use of chrysotile. Four possible mechanisms to explain this paradox have been proposed but this phenomenon does not support the claim that amphibole is inert. The final issue discussed is the textile mystery, i.e., the higher incidence of cancer in asbestos textile plants compared to asbestos mines where the same asbestos was produced and the exposure levels were comparable. This phenomenon was first reported in North America followed by UK and then in the present observations from China. Previously, levels of fiber exposure were calculated using a universal converting coefficient to estimate the mass concentration versus fiber concentration. However, parallel measurements of fiber and mass concentrations in the workplace and exposed air indicated that there are wide variations in the fiber/mass ratio, which unjustifies the universal conversion. It is possible that contamination by airborne non-fibrous particles in mines with mass fiber conversion led to the overestimation of fiber concentrations and resulted in the textile mystery. Although the use and manufacturing of asbestos has been banned in Japan, more than 10 million tons of asbestos had been imported and the majority remains in existing buildings. Thus, efforts to control asbestos exposure should be continued.

Metástasis cutánea de mesotelioma pleural / Cutaneous metastasis of pleural mesothelioma

Las metástasis cutáneas de mesotelioma pleural son muy raras y con una supervivencia muy corta. Se presenta un paciente de 80 años, con una placa eritematoviolácea duro elástica ubicada en flanco abdominal derecho, de 8 meses de evolución y rápido crecimiento. Se realiza diagnóstico de metástasis cutánea de mesotelioma pleural, se indica tratamiento quimioterápico paliativo pero fallece por falla multiorgánica, sin llegar a recibirlo...

Clinical and Prognostic Features of Erionite-Induced Malignant Mesothelioma

This review analytically examines the published data for erionite-related malignant pleural mesothelioma (E-MPM) and any data to support a genetically predisposed mechanism to erionite fiber carcinogenesis. Adult patients of age > or =18 years with erionite-related pleural diseases and genetically predisposed mechanisms to erionite carcinogenesis were included, while exclusion criteria included asbestos- or tremolite-related pleural diseases. The search was limited to human studies though not limited to a specific timeframe. A total of 33 studies (31042 patients) including 22 retrospective studies, 6 prospective studies, and 5 case reports were reviewed. E-MPM developed in some subjects with high exposures to erionite, though not all. Chest CT was more reliable in detecting various pleural changes in E-MPM than chest X-ray, and pleural effusion was the most common finding in E-MPM cases, by both tests. Bronchoalveolar lavage remains a reliable and relatively less invasive technique. Chemotherapy with cisplatin and mitomycin can be administered either alone or following surgery. Erionite has been the culprit of numerous malignant mesothelioma cases in Europe and even in North America. Erionite has a higher degree of carcinogenicity with possible genetic transmission of erionite susceptibility in an autosomal dominant fashion. Therapeutic management for E-MPM remains very limited, and cure of the disease is extremely rare.

Study on identification of traditional Chinese medicine Yangqishi and Yinqishi by X-ray diffraction / 中国中药杂志

The aim of this paper is to clarify the mineral origin of traditional Chinese medicine (TCM) Yangqishi and Yinqishi and guide identification of the both, by X-ray diffraction (XRD) Fourier patterns. Morphological identification and conventional physical and chemical analysis wee used to identify 22 batches of Yangqishi and Yinqishi. It used XRD Fourier patterns which has been collected from sample powders to analyze phase composition. It has been found experimentally that the mineral origin of Yinqishi is Talc schist and the mineral origin of Yangqishi is tremolite and actinolite. The results also showed that the method using XRD can get not only an accurate but also rapid identification of Yangqishi and Yinqishi. There are many differences in medicinal properties, efficacy, indications and composition of Yangqishi and Yinqishi, so be careful not to mix them up.

Mesotelioma maligno: experiencia clínico-patológica de 247 casos / Malignant mesothelioma: clinical and pathological features from 247 cases

Objective: This study describes the frequency, occupational, clinical, and pathological features in a large cohort of cases of Malignant Mesothelioma (MM) from the National Institute of Respiratory Diseases (INER), in México. Methods: A retrospective and transversal study was carried out in medical records of patients diagnosed with MM between the years 1991 to 2007. Results: Of the 247 patients, 184 were male and 63 were female with an average age of 51-60 years. Dyspnea and chest pain were the presenting symptoms in most of the patients. Exposure to asbestos was referred only in 34 percent of cases but direct exposition only was documented in five of them. Clinical features of MM patients were similar in asbestos related and non-asbestos related malignant mesothelioma. Conclusion: Although a growing tendency is observed in, the number of cases with MM, in many of them was not possible to establish the source of asbestos exposure.

Objetivo: Este estudio describe la frecuencia, características patológicas, ocupación y exposición a asbesto en una cohorte grande de casos de mesotelioma maligno (MM) admitidos en el Instituto Nacional de Enfermedades Respiratorias (INER), en México. Método: Se llevó a cabo un estudio retrospectivo y transversal en los registros médicos de pacientes diagnosticados con MM entre los años 1991-2007. Resultados: De los 247pacientes, 184 fueron hombres y 63 fueron mujeres con un promedio de edad de 51 y 60 años. Disnea y dolor torácico fueron los principales síntomas observados. Exposición a fibras de asbesto fue referida sólo en 34 por ciento) de los casos, aunque una exposición directa sólo puedo ser documentada en cinco de ellos. Las características clínicas de los pacientes con MM fueron similares en aquellos con y sin exposición a asbesto reconocida. Conclusión: Aunque se observa una tendencia creciente en el número de casos con MM, en muchos de ellos no fue posible establecer una fuente de exposición a asbesto como la causa de contaminación para el desarrollo de la enfermedad.