Malignant pleural mesothelioma in a 17-year old boy: A case report and literature review.

BACKGROUND: Malignant pleural mesothelioma is a rare, invasive and often fatal neoplasm that develops in the thin layer of tissue surrounding the lungs known as the pleura. Although rare, mesotheliomas do occur in the young; their characteristics are distinct from those of older patients. CASE PRESENTATION: This is a case report of a 17-year-old boy who had moderate dyspnea, cough, right-sided pleuritic chest pain, fever, headache and no weight loss. Physical examination showed a right pleural effusion and chest roentgenograms revealed a homogenous opacity on lower right hemithorax. Biochemical analysis of pleural fluid showed hemorrhagic/turbid effusion compatible with exudate. It was initially treated as an empyema. The pleural fluid culture was negative. Adenosine deaminase level was 34.3 U/L (admission) and 19.02 U/L (two weeks after). Pleural fluid smear and culture for Mtb were negative. During the open pleural biopsy, thickened pleura and multiple pale yellow nodules in the lung were observed. The histopathological report was compatible with malignant pleural mesothelioma. With this diagnosis, a chemotherapy regimen with cisplatin was initiated. After two cycles, the patient had no clinical and radiological improvement. The patient is currently under regular follow up. CONCLUSION: MPM is rare in young adults and its clinical presentation makes it different from mesothelioma in elderly patients, so it will be necessary to identify the new risk factors that can identify these patients.

Mouse mammary tumor virus-like gene sequences in breast cancer samples of Mexican women.

BACKGROUND: Previous reports related the presence of mouse mammary tumor virus (MMTV)-like gene sequences to human breast carcinoma. The aim of this study was to determine whether MMTV-like env gene sequences are present in breast cancer samples of Mexican women and in breast and lung cancer cell lines. METHODS: Using specific primers for MMTV, we tested 3 breast cancer cell lines, 4 non-small lung cancer cell lines and 119 breast cancer samples from Mexican women. RESULTS: MMTV-like gene sequences were amplified in the lung cancer cell INER-51, but not in the MCF-7 cell line that has been used as a positive control in other reports and in 5 of 119 (4.2%) breast cancer biopsy tissues. Furthermore, the identity of sequences of PCR products from INER-51 and a breast cancer-positive sample are 98 and 99% when compared with the env region of MMTV (GenBank accession No. AY161347). CONCLUSION: These results indicate that MMTV-like gene sequences are present in the Mexican population.

[Malignant mesothelioma: clinical and radiological description of 45 cases with and without asbestos exposure]. / Mesotelioma maligno: descripción clínica y radiológica de 45 casos con y sin exposición a asbestos.

OBJECTIVE: Our aim was to identify and describe the main symptoms, clinical presentation, and radiographic changes in malignant mesothelioma (MM) patients. MATERIAL AND METHODS: We reviewed the medical and X-ray records of all patients diagnosed with MM, admitted between 1991 and 1998 to the National Institute of Respiratory Diseases (INER), which is a governmental institution specialized in chest disease in Mexico City. The following data were collected: Age, occupation, asbestos exposure, latency, family history of cancer, clinical symptoms, and X-ray changes. Data are presented as percentages by sex and age group. RESULTS: We found 45 cases of MM; in 80% of them a history of asbestos exposure could not be documented. The 51-60 years age group had the highest frequency of MM. Dispnea and chest pain were the presenting symptoms in most patients. Pleural effusion and pleural thickening were the X-ray abnormalities observed in 75% of the patients. CONCLUSIONS: The clinical and radiographic findings among patients with MM without asbestos exposure were similar to those with a history of asbestos exposure.

[Structure and function of the T-lymphocyte antigen receptor and its role in infectious diseases]. / Estructura y función del receptor de antígeno de linfocitos T y su papel en enfermedades infecciosas.

The T lymphocytes recognize antigens through antigen receptors (TcRs) and the major histocompatibility complex (MHC) molecules: they lysate the cells that bear the antigen, or release cytokines that are mediators of the immune response. The TcRs recognize antigens in the form of short peptides bound to MHC molecules. So far, there are two isotypes of TcR: gamma/delta and alpha/beta, which appear in the sequence during T-cell ontogeny. The process of selection of TcRs during thymic ontogeny obeys to molecular mechanisms which generate intracellular events that will participate in the gene expression of the TcR. The aim of the present paper is to review the molecular, structural, and functional aspects of the TcRs, and their role in human autoimmune infectious disease.

[Molecular bases of cancer immunology]. / Bases moleculares de la inmunología del cáncer.

The immune system is a tight network of different types of cells and molecules. The coordinated action of these elements mounts a precise immune response against tumor cells. However, these cells present several escape mechanisms, leading to tumor progression. This paper shows several cellular and molecular events involved in the regulation of the immune response against tumor cells. The interaction of several molecules such as MHC, TcR, adhesins, tumor antigens and cytokines are discussed, as well as the most recent knowledge about escape mechanisms and immunotherapy.