Marta Ortega-Martínez

International NeuroAIDS: prospects of HIV-1 associated neurological complications.

ABSTRACTNeurological complications associated with HIV-1/AIDS are being recognized with a high frequency that parallels the increased number of AIDS cases. The early infiltration by HIV-1 into the nervous system can cause primary and/or secondary neurological complications. The most common neurocognitive disorder is AIDS Dementia Complex (ADC). In developing countries of Asia the three most opportunistic infections are tuberculosis (TB), cryptococcosis, and Pneumocystis carinii pneumonia. Therefore, it is expected that secondary neurological complications due to TB and cryptococcosis will be the most common cause of morbility and mortality in HIV-1/AIDS cases in China. Research of NeuroAIDS in China is necessary to understand the impact and the biology of HIV-1 in the nervous system. Future studies would include, the molecular epidemiology and the description of opportunistic infections associated to HIV-1; the neuropathological description of primary and secondary HIV-1 complications in different groups; the HIV-1 neurotropism and immune response studies for Chinas unique HIV-1 strains and recombinant forms derived from the nervous system, including experimental models such as the use of transgenic rats; and the study of potential resistant virus, primarily when the anti-retroviral therapy (ART) has not full access in the brain.

Ultrastructural findings in semen samples of infertile men infected with Chlamydia trachomatis and mycoplasmas

The aim of this study was to describe the ultrastructural features observed in semen samples of men with infertility and subfertility of unknown cause infected with Chlamydia trachomatis and mycoplasmas. The findings observed by ultrastructure included destruction or persistence of bacteria in leukocytes, phagocytosis of spermatozoa by leukocytes, and structural damage of spermatozoa.

Identification of human remains by DNA analysis of the gastrointestinal contents of fly larvae.

Dipterous fly larvae (maggots) are frequently collected from a corpse during a criminal investigation. Previous studies showed that DNA analysis of the gastrointestinal contents of maggots might be used to reveal the identity of a victim. However, this approach has not been used to date in legal investigations, and thus its practical usefulness is unknown. A badly burned body was discovered with its face and neck colonized by fly larvae. Given the condition of the body, identification was not possible. Short tandem repeat (STR) typing was performed using the gastrointestinal contents of maggots collected from the victim and was compared to STR profiles obtained from the alleged father. The probability of paternity was 99.685%. Thus, this comparative DNA test enabled the conclusive identification of the remains. This is the first reported case of analysis of human DNA isolated from the gastrointestinal tract of maggots used to identify a victim in a criminal case.

Evidence of chondrocyte turnover in lung cartilage, with the probable participation of nestin-positive cells.

Healthy adult cartilage is thought to have little or no capacity to renewal, and cell turnover has not been reported in lung cartilage. We report that chondrocyte turnover occurs in lung cartilage, found in an unrelated study. Lung specimens from CD1 mice of 2, 6, 12, 18 or 24 months were fixed in 10% neutral‐buffered formalin and paraffin‐embedded. Apoptosis was analysed by in situ end‐labelling of fragmented DNA. Proliferating cell nuclear antigen (PCNA) and nestin were examined by immunohistochemistry. Apoptosis and PCNA were detected in lung chondrocytes. Serial section analysis showed that cells in apoptosis were different from PCNA‐positive cells, indicating that turnover was occurring. Chondrocytes were negative for nestin. Nestin‐positive cells were present in connective tissue associated with cartilage, in some specimens in close proximity of it and in perivascular cells. Thus cell turnover in lung cartilage is possible, which may be mediated by nestin‐positive cells.

Phagocytosis of spermatozoa and leucocytes by epithelial cells of the genital tract in infertile men infected with Chlamydia trachomatis and mycoplasmas

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Multinucleation of spermatozoa and spermatids in infertile men chronically exposed to carbofuran

OBJECTIVE To report the findings encountered in semen samples coming from two infertile men chronically exposed to carbofuran. METHODS Semen samples were collected and analyzed as recommended by the World Health Organization. A morphological analysis was carried out by light microscopy. RESULTS Seminal analysis revealed in the first case a total concentration of 42 million spermatozoa/mL with 17% motility and 20% normal shape. The second patient presented a total concentration of 5 million spermatozoa/mL with 6% motility and 2% normal shape. The patients presented a similar percentage of binucleated spermatozoa (28 and 26%) and of multinucleated spermatids (10 and 6%). CONCLUSION To our knowledge, this is the first time that alterations in semen samples of men exposed to carbofuran are reported. More research in this area is needed to make conclusions on the subject.

Polymorphisms in GSTM1, GSTT1, GSTP1, and GSTM3 genes and breast cancer risk in northeastern Mexico.

Glutathione S-transferases (GSTs) are a family of phase II metabolizing enzymes involved in carcinogen detoxification and the metabolism of various bioactive compounds. Several genes that code for these enzymes are polymorphic in an ethnicity-dependent manner, with particular genotypes previously associated with an increased risk of breast cancer. The purpose of this study was to determine the frequencies of polymorphisms in the genes GSTM1, GSTT1, GSTP1, and GSTM3 and to investigate whether an association exists between these genes and breast cancer risk in subjects from northeastern Mexico. Genotypes were determined for 243 women with histologically confirmed breast cancer and 118 control subjects. Gene polymorphisms were analyzed using a DNA microarray. We found an increased breast cancer risk associated with the GSTM1 gene deletion polymorphism (OR = 2.19; 95%CI = 1.50-3.21; P = 0.001). No associations between the GSTT1, GSTP1, and GSTM3 genotypes and neoplasia risk were observed. In conclusion, we determined the genotype distribution of GST polymorphisms in control subjects and breast cancer patients from northeastern Mexico. The GSTM1 null genotype was associated with breast cancer risk. Our findings may be used to individualize breast cancer screening and therapeutic intervention in our population, which displays ethnic characteristics that differentiate it from other populations in Mexico.

Nestin-positive Stem Cells Participate in Chondrocyte Renewal in Healthy Adult Lung Cartilage

Se considera que el cartilago adulto sano tiene poca o ninguna capacidad para renovarse, y que sus condrocitos permanecen en un estado de reposo estable, careciendo de las propiedades de proliferacion y diferenciacion. Recientemente encontramos que el recambio celular en el cartilago pulmonar es posible y que celulas troncales positivas para nestin pudieran tener algun papel en el mismo. En este articulo, reportamos nuevos hallazgos acerca de la renovacion de condrocitos en el cartilago pulmonar. Pulmones de ratones CD1 de 2, 6, 12, 18 o 24 meses de edad se fijaron en formalina amortiguada al 10% y se incluyeron en parafina. Se analizo la expresion de nestin utilizando un metodo inmunohistoquimico basado en un sistema de deteccion con peroxidasa. Encontramos celulas positivas para nestin en el interior de los islotes de cartilago y celulas en division muy cercanas a ellas. Estos hallazgos indican que existen celulas madre mesenquimales positivas para nestin en el adulto con capacidad para diferenciarse en condrocitos pulmonares, probablemente para mantener la homeostasis tisular o reparar danos en el tejido. Asimismo, estos hallazgos pueden aumentar nuestra comprension acerca de las propiedades biologicas del cartilago y podrian proporcionar nuevos candidatos para la ingenieria celular en la terapia regenerativa en enfermedades de las articulaciones.

Detection of a novel stem cell probably involved in normal turnover of the lung airway epithelium

Regeneration of the lung airway epithelium after injury has been extensively studied. In contrast, analysis of its turnover in healthy adulthood has received little attention. In the classical view, this epithelium is maintained in the steady‐state by the infrequent proliferation of basal or Clara cells. The intermediate filament protein nestin was initially identified as a marker for neural stem cells, but its expression has also been detected in other stem cells. Lungs from CD1 mice at the age of 2, 6, 12, 18 or 24 months were fixed in neutral‐buffered formalin and paraffin‐embedded. Nestin expression was examined by an immunohistochemical peroxidase‐based method. Nestin‐positive cells were detected in perivascular areas and in connective tissue that were in close proximity of the airway epithelium. Also, nestin‐positive cells were found among the cells lining the airway epithelium. These findings suggest that nestin‐positive stem cells circulate in the bloodstream, transmigrate through blood vessels and localize in the lung airway epithelium to participate in its turnover. We previously reported the existence of similar cells able to differentiate into lung chondrocytes. Thus, the stem cell reported here might be a bone marrow‐derived mesenchymal stem cell (BMDMSC) able to generate several types of lung tissues. In conclusion, our findings indicate that there exist a BMDMSC in healthy adulthood that participates in the turnover of the lung airway epithelium. These findings may improve our knowledge about the lung stem cell biology and also provide novel approaches to therapy for devastating pulmonary diseases.

The Role of Chlamydia trachomatis in Male Infertility

Chlamydia spp. are associated with a broad clinical spectrum of human diseases, including cardiovascular disease, and pulmonary, ocular and urogenital tract infections [1]. C. trachomatis is an obligate intracellular pathogen. The infection cycle starts with the entry of an infectious particle (elementary body or EB) into an epithelial cell. The EB-laden cytoplasmic vacuole (inclusion) migrates to the peri-Golgi region as the EB differentiates into a noninfectious but metabolically active reticulate body (RB). After replication, progeny RBs differentiate back to EBs for exiting the infected cells to disseminate to adjacent cells [2].