Prevalence of human papillomavirus types in North and Central regions of Mexico.

Human papillomavirus (HPV) is a DNA virus linked to mucosal and cutaneous carcinogenesis. More than 200 different HPV types exist. We carried out a transversal study to investigate the prevalence of HPV types in two regions of Mexico. A total of 724 genital and non-genital samples from women (F) and men (M) were studied; 241 (33%) from North-Eastern (NE) and 483 (66%) from South-Central (SC) Mexico. The overall prevalence was 87%. In genital lesions from females, the NE group showed a prevalence of HPV types 16 (37%), 6 (13%), 59 (6%), 11, 18 and 66 (5.4% each); and the SC group showed types 6 (17%), 16 (15%), 11 (14.5%), 18 (12%) and 53 (6%). In the genital lesions from males, NE group showed types 16 (38%), 6 (21%), 11 (13%) and 59 plus 31 (7.5%) and the SC group showed types 6 (25%), 11 (22%), 18 (17%) and 16 (11.5%). When the two regions were compared, a higher prevalence of low-risk HPV 6 and 11 was found in the SC region and of high-risk HPV 59, 31 and 66 (the latter can also be present in benign lesions) in the NE region. Our findings complement efforts to understand HPV demographics as a prerequisite to guide and assess the impact of preventive interventions.

Localisation and quantification of alkali-labile sites in human spermatozoa by DNA breakage detection-fluorescence in situ hybridisation.

The localisation and quantification of constitutive alkali-labile sites (ALSs) were investigated using a protocol of DNA breakage detection plus fluorescence in situ hybridisation (DBD-FISH) and alkaline single-cell gel electrophoresis (SCGE or comet assay), in spermatozoa of infertile and fertile men. Semen samples from 10 normozoospermic patients undergoing infertility treatment and 10 fertile men were included in this study. ALSs were localised and quantified by DBD-FISH. The region most sensitive to alkali treatment in human spermatozoa was located in the basal region of the head. ALSs were more frequent in spermatozoa of infertile men than in those of fertile men. These results were confirmed by SCGE comet assays. In conclusion, the most intense localisation of hybridisation signals in human spermatozoa, representing the highest density of constitutive ALSs, was not randomly distributed and was predominantly located in the base of the head. Moreover, infertile men presented with an increase in ALS frequency. Further studies are necessary to determine the association between ALS, sperm chromatin organisation and infertility.

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.

Anomalous pulmonary vein drainage is not a contraindication for VATS lobectomy.

This is a case report on a 26-year-old woman with metastatic mandibular osteosarcoma to the lung. A video-assisted thorascopic surgery (VATS) completion left upper lobe lobectomy was attempted, but was converted to a thoracotomy when anomalous pulmonary vein drainage (APVD) was identified. There were no other anomalies found and the lobectomy was completed as planned. To our knowledge, this is the first reported case of an attempted VATS lobectomy for patients with APVD. This case demonstrates that APVD tends not to be associated with any other anatomic abnormalities in the lung and should not be a contraindication for VATS lobectomy.

Chromosomal damage as prognosis marker in cervical carcinogenesis.

Cancer of the uterine cervix is the third most common cancer in women worldwide and the most common cancer among Mexican and Latin American women. Risk factors that have been associated with the development of cervical intraepithelial neoplasia suggest that Human Papillomavirus (HPV) types 16, 18, 31, and 33 entail a high risk of developing a malignancy of this type. The accumulation of genetic alterations allows the growth of neoplastic cells; chromosomal instability is an event that occurs in the precancerous stages. The candidate cancer risk biomarkers include cytogenetic endpoints, such as chromosomal aberrations, sister chromatid exchange, micronuclei, and the outcomes of comet assay and DNA breakage detection-fluorescence in situ hybridization. The patterns identified in these cytogenetic studies indicate that chromosomal instability is a transient and chromosomally unstable intermediate in the development of cervical lesions. In this context, the mechanisms that may underlie the progressive increase in genetic instability in these patients seem to be related directly to HPV infection. The studies discussed in this paper show that chromosomal instability may serve as a biomarker by predicting the progression of cervical intraepithelial neoplasia. Nevertheless, these results should be validated in larger, prospective studies.

Exotoxins secreted by Clostridium septicum induce macrophage death: Implications for bacterial immune evasion mechanisms at infection sites.

The induction of macrophage death is considered a potential mechanism by which components secreted by Clostridium septicum are used to evade the innate immune response and cause tissue damage. This study aimed to determine the effects of partially purified fractions of extracellular proteins secreted by C. septicum on the death of mouse peritoneal macrophages. Elicited mouse peritoneal macrophages were incubated with partially purified fractions of proteins secreted by C. septicum into the culture medium. After incubation, the protein fraction with a molecular weight ≥100 kDa caused significant cell death in macrophages, altered cell morphology, increased the expression of markers of apoptosis and autophagy, and increased the expression (protein and mRNA) of IL-10 and TNFα. Our data suggest that the proteins secreted by C. septicum (MW, ≥100 kDa) induce cell death in macrophages by promoting autophagy-triggered apoptosis. This study may contribute to our understanding of the molecular mechanism of immune evasion by C. septicum at the infection site.

Thoracic vessel injury.

Thoracic trauma occurs in an estimated 25% of all trauma victims, with approximately 50% of trauma mortalities attributable to these injuries. Only 4% of thoracic traumas involve injuries to thoracic vessels, including the aorta, innominate veins and artery, left carotid artery, internal mammaries, and pulmonary hilar vessels. These vascular injuries can range from minor to major with advances in prehospital management increasing the number of patients surviving in the field and presenting to the hospital with life-threatening vascular injuries. Rapid assessment during the initial survey and interventions to maintain airway, breathing, and circulation of the patient can be life-saving. The patient's hemodynamic status will often dictate the extent of the initial workup or whether the patient requires emergent operation. Stable patients can undergo further assessment and detailed imaging, such as computed tomography and/or angiography. Treatment of thoracic vessel injuries may include advanced endovascular techniques, traditional open surgery, or non-operative management with observation. The following review systematically details the initial workup, evaluation and management techniques of thoracic vessel injuries.

Source apportionment and ozone formation mechanism of VOCs considering photochemical loss in Guangzhou, China.

Understanding the sources and impact of volatile organic compounds (VOCs) on ozone formation is challenging when the traditional method does not account for their photochemical loss. In this study, online monitoring of 56 VOCs was carried out in summer and autumn during high ozone pollution episodes. The photochemical age method was used to evaluate the atmospheric chemical loss of VOCs and to analyze the effects on characteristics, sources, and ozone formation of VOC components. The initial concentrations during daytime were 5.12 ppbv and 4.49 ppbv higher than the observed concentrations in the summer and autumn, respectively. The positive matrix factorization (PMF) model identified 5 major emission sources. However, the omission of the chemical loss of VOCs led to underestimating the contributions of sources associated with highly reactive VOC components, such as those produced by biogenic emissions and solvent usage. Conversely it resulted in overestimating the contributions from VOC components with lower chemical activity such as liquefied petroleum gas (LPG) usage, vehicle emissions, and gasoline evaporation. Furthermore, the estimation of ozone formation may be underestimated when the atmospheric photochemical loss is not taken into account. The ozone formation potential (OFP) method and propylene-equivalent concentration method both underestimated ozone formation by 53.24 ppbv and 47.25 ppbc, respectively, in the summer, and by 40.34 ppbv and 26.37 ppbc, respectively, in the autumn. The determination of the ozone formation regime based on VOC chemical loss was more acceptable. In the summer, the ozone formation regime changed from the VOC-limited regime to the VOC-NOx transition regime, while in the autumn, the ozone formation regime changed from the strong VOC-limited regime to the weak VOC-limited regime. To obtain more thorough and precise conclusions, further monitoring and analysis studies will be conducted in the near future on a wider variety of VOC species such as oxygenated VOCs (OVOCs).

[Identification of components of metabolic syndrome in Mexican patients hospitalized for acute ischemic coronary syndrome: a tool for prevention]. / Identificación de componentes del síndrome metabólico en pacientes mexicanos hospitalizados por síndrome isquémico coronario agudo: una herramienta para la prevención.

OBJECTIVE: To determine the prevalence of metabolic syndrome (MS) and its risk factors in patients with Acute Ischemic Coronary Syndrome (AICS) in a tertiary hospital. METHODS: A total of 65 patients admitted to Cardiac Intensive Care Unit with myocardial infarction or unstable angina participated. MS was diagnosed in accordance to the Adult Treatment Panel III (ATPIII) criteria. RESULTS: The total prevalence of MS was 84.6% (95% CI: 75.6 to 93.6). MS was more frequent in women, persons with obesity according to the body mass index (BMI), family background diabetes, and dyslipidemia. Phenotype predictors of MS were: BMI (OR=2.12, 95% CI: 1.24, 3.17) and familiar history of dyslipidemia (OR=0.026, 95% CI: 0.003, 0.587). CONCLUSIONS: The prevalence of MS with AICS is higher than that reported in other populations. This fact is alarming if this risk is maintained in the Mexican population.

Association of HLA DRB1 alleles with juvenile idiopathic arthritis in Mexicans.

OBJECTIVE: The aim of the study was to investigate association between HLA class II alleles and juvenile idiopathic arthritis (JIA) in Mexican patients. PATIENTS AND METHODS: We typed 120 patients with JIA and 99 healthy controls for HLA class II alleles were performed by PCR-SSO. Differences between the whole group of JIA and its subtypes and controls were calculated by using the Xi2; p-values were corrected (pc) with Bonferroni's test. RESULTS: The alleles HLA-DRB1*01 (pc= 0.00083) and HLA-DRB1*04 (pc=0.0049) were strongly associated with systemic JIA, while HLA-DRB1*11 and HLA-DRB1*14 were found to have decreased frequencies in the patients with systemic JIA compared to the controls. Two alleles were found to have increased frequencies with JIA oligoarthritis subgroup, HLA-DRB1*11 (p=0.01, pc=NS) and HLA-DRB1*13 (p=0.01, pc=NS). The HLA-DRB1*04 was found increased frequencies with susceptibility for RF negative and RF positive polyarthritis JIA subgroups (p correction resulted in loss of significance). In contrast two alleles HLA-DRB1*07 and HLA-DRB1*14 were found decreased frequencies only patients RF positive polyarthritis JIA subgroup compared to the controls (pc=NS). CONCLUSION: The profile of HLA-DRB1 alleles associations in Mexican with JIA were somewhat distinct from association typically found in Caucasians.

Association between human papilloma virus-type infections with micronuclei frequencies.

To determine the association between Human papillomavirus (HPV)-type infections with the frequency of Micronucleus (MN), a hospital-based, unmatched case-control study was carried out. We evaluated and compared the average number of MN/1,000 cells among three groups of Mexican females. Twenty one women ranging in age from 31-56 years and divided into three groups were studied. Group I comprised seven control women without cervical lesions and with HPV-negative, Group II was composed of seven women with Squamous intraepithelial lesions (SIL) infected with low-risk HPV low-risk, and Group III was made up of seven women with SIL infected with high-risk HPV infection. Analysis of variance (ANOVA) test revealed differences among Groups I (5.14+/-3.02), II (13.43+/-3.41), and III (25.43+/-3.41) (F=67.46; P=0.0001). We demonstrated an association between HPV type infection and higher MN frequencies. However, a larger controlled study with sufficient follow-up will be required to further evaluate the usefulness of this test in the clinical management of women with HPV infection.

Total homocysteine levels in healthy children from the Monterrey metropolitan area, Mexico.

Currently, there are indications for determining hyperhomocysteinemia in adulthood as risk factors for cardiovascular diseases, psychiatric disorders, pregnancy complications, birth defects, cognitive impairment in the elderly, in addition to cancer. If hyperhomocysteinemia is determined from childhood, it may be modulated with the provision of an opportunity for public health intervention. The objective of this descriptive study was to determine total homocysteine (tHcy) levels in healthy children from the Monterrey metropolitan area in Mexico. In a peripheral-blood sample collected from 56 healthy children aged 2-10 years, we determined tHcy concentration by high performance liquid chromatography (HPLC) with fluorescence detection. The geometric mean +/- SD was 9.78 +/- 1.73 micromol/l. tHcys of the children studied were homogeneous by age cohort and gender. Nutritional state was classified by body mass index (BMI). Sixty five percent of children who participated in the study had normal BMI, and 96% of the children belong to the low socioeconomic status. In conclusion, to our knowledge this is the first-ever information on homocysteine (Hcy) prevalence in a population of healthy Mexican children. tHcy concentration was higher than that reported in other populations studies. This preliminary study could constitute the baseline for future public health studies.

PON1 lactonase activity and its association with cardiovascular disease.

BACKGROUND: Paraoxonase 1 (PON1) is important in the development of atherosclerosis, and it has become the subject of intensive research. Our aim was to evaluate the association of serum PON1 activity and polymorphisms with cardiovascular disease (CVD) using four different substrates. MATERIALS AND METHODS: Activity of PON1-related to arylesterase (AREase and 4-CMPAse), paraoxonase (PONase), and lactonase (LACase), and polymorphisms (A-162G, T-108C, L55M, and Q192R) were evaluated in subjects with CVD, cardiovascular risk factor (CFR), and controls. An ordered logistic-regression analysis of PON1 phenotypes was performed in the CVD group with respect to the control group. RESULTS AND CONCLUSIONS: Logistic-regression analysis showed that CC-108 genotype was associated with CRF and CVD. The CVD group had the lowest activities of PON1. The LACase might be a better biomarker for CVD (OR, 0.52; 95% CI, 0.44-0.61) followed by CMPAse (OR, 0.82; 95% CI, 0.77-0.86), AREase (OR, 0.98; 95% CI, 0.97-0.99) and PONase (OR, 0.99, 95% CI, 0.99-0.99). Logistic regression of PON1 phenotypes by haplotypes showed that LACase activity was not influenced by the polymorphisms and that it could be a new potential biomarker in the development of CVD. Larger scale longitudinal studies are required.

Eighth international mesothelioma interest group.

The eighth International Mesothelioma Interest Group (IMIG) meeting was held in Chicago, IL, United States, in 19-22 October 2006 to discuss mesothelioma - the cancer often linked to asbestos exposure. It is a very aggressive malignancy with a median survival of less than 1 year from diagnosis. Millions of people have been exposed worldwide to asbestos, especially during the second half of the twentieth century when asbestos use increased significantly. The tons of asbestos utilized in the past remain a health hazard for current and future generations because asbestos is difficult to be disposed off. This makes asbestos and mesothelioma research a public health issue in addition to a medical problem. Moreover, the very high costs of asbestos litigation have a significant impact on the whole economy. In the United States, up until 2001, defendant companies had paid 54 billion dollars in claims and estimated future liabilities ranged from 145 to 210 billion. Therefore, asbestos research is of great interest to a large audience that includes patients, millions of asbestos-exposed individuals, scientists, physicians, public health officials, politicians, unions of asbestos workers, lawyers and the public at large. During the past few years, there has been significant progress in understanding the process of mineral fiber carcinogenesis and mesothelioma pathogenesis. With improved understanding of the pathogenesis of mesothelioma, new diagnostic, preventive and therapeutic options are being developed. A total of 247 papers were presented at the IMIG: the abstracts of these presentations were published in Lung Cancer, Supplement 1, October 2006. Here, experts in different disciplines critically review some of the most exciting presentations of the IMIG meeting. The result is a comprehensive review of the research field of asbestos carcinogenesis and mesothelioma, and of the progress that has been made in recent years in both basic and clinical sciences.

Frequency of micronuclei in Mexicans with type 2 diabetes mellitus.

A case-control study was carried out on a sample of 15 Mexican patients (40-56 years old) with type 2 diabetes mellitus (DM2) that had developed five years and been treated with oral hypoglycemic drugs (sulfonylurea and/or metformin), with no microvascular or macrovascular complications. The aim of this study was to assess whether Mexican patients with DM2 differed from a control group in the frequency of micronuclei (MN). A control group of 10 individuals without DM2 (38-54 years old) was included. The frequency of MN in binucleated lymphocytes was analyzed according to the Fenech criteria. At time being this investigation should be considered as a preliminary study in which the influence of potential confounders cannot be adequately assessed. However, our result showed a MN frequency significant increase in DM2 patients (6.53 +/- 2.03 per 1000 cells) relative to that of the control group (3.10 +/- 1.79 per 1000 cells). MN may constitute a possible component of a panel of biomarkers for the risk of DM2. This cytogenetic damage also indicates an enhanced risk of cancer, as has been found in previous studies. These results should be validated by other researchers.

Digital image analysis of AgNORs in cervical smears of women with premalignant and malignant lesions of the uterine cervix.

We performed a hospital-based, unmatched case-control study to investigate the association between progressive stages of cervical neoplasia and digital analysis of cell proliferation by silver stained nucleolus organizer region associated proteins (AgNORs). We measured cell proliferation levels in the cervical epithelial cells of 10 women with low grade squamous intraepithelial lesions (LG-SIL), eight with high grade squamous intraepithelial lesions (HG-SIL), 11 with cervical cancer (CC) and eight with no cervical lesions (controls) using the AgNORs technique. Cell proliferation was measured by digital image analysis (DIA). DIA revealed increased total areas of AgNORs in HG-SIL and CC compared to LG-SIL and control patients. AgNORs with a kidney or cluster shape exhibited greater areas than those with a spherical or long shape. We propose a cut-off of 118 pixels to differentiate benign (control and LG-SIL) from malignant (HG-SIL and CC) lesions. DIA of AgNORs is a simple and inexpensive method for studying proliferation. The increased total area of AgNORs in malignant lesions provides information regarding cell behavior and may be related to cervical carcinogenesis; however, further validation studies are required to establish its usefulness in cytological analysis.

Admixture and genetic relationships of Mexican Mestizos regarding Latin American and Caribbean populations based on 13 CODIS-STRs.

Short tandem repeats (STRs) of the combined DNA index system (CODIS) are probably the most employed markers for human identification purposes. STR databases generated to interpret DNA profiles are also helpful for anthropological purposes. In this work, we report admixture, population structure, and genetic relationships of Mexican Mestizos with respect to Latin American and Caribbean populations based on 13 CODIS-STRs. In addition, new STR population data were included from Tijuana, Baja California (Northwest, Mexico), which represents an interesting case of elevated genetic flow as a bordering city with the USA. Inter-population analyses included CODIS-STR data from 11 Mexican Mestizo, 12 Latin American and four Caribbean populations, in addition to European, Amerindian, and African genetic pools as ancestral references. We report allele frequencies and statistical parameters of forensic interest (PD, PE, Het, PIC, typical PI), for 15 STRs in Tijuana, Baja California. This Mexican border city was peculiar by the increase of African ancestry, and by presenting three STRs in Hardy-Weinberg disequilibrium, probably explained by recurrent gene flow. The Amerindian ancestry in Central and Southeast of Mexico was the greatest in Latin America (50.9-68.6%), only comparable with the North of Central America and Ecuador (48.8-56.4%), whereas the European ancestry was prevalent in South America (66.7-75%). The African ancestry in Mexico was the smallest (2.2-6.3%) in Latin America (≥ 2.6%), particularly regarding Brazil (21%), Honduras (62%), and the Caribbean (43.2-65.2%). CODIS-STRs allowed detecting significant population structure in Latin America based on greater presence of European, Amerindian, and African ancestries in Central/South America, Mexican Mestizos, and the Caribbean, respectively.

Resection margins, extrapleural nodal status, and cell type determine postoperative long-term survival in trimodality therapy of malignant pleural mesothelioma: results in 183 patients.

OBJECTIVES: Our aim was to identify prognostic variables for long-term postoperative survival in trimodality management of malignant pleural mesothelioma. METHODS: From 1980 to 1997, 183 patients underwent extrapleural pneumonectomy followed by adjuvant chemotherapy and radiotherapy. RESULTS: Forty-three women and 140 men (age range 31-76 years) had a median follow-up of 13 months. The perioperative mortality rate was 3.8% (7 deaths) and the morbidity, 50%. Survival in the 176 remaining patients was 38% at 2 years and 15% at 5 years (median 19 months). Univariate analysis identified 3 prognostic variables associated with improved survival: epithelial cell type (52% 2-year survival, 21% 5-year survival, 26-month median survival; P =.0001), negative resection margins (44% at 2 years, 25% at 5 years, median 23 months; P =.02), and extrapleural nodes without metastases (42% at 2 years, 17% at 5 years, median 21 months; P =.004). Using the Cox proportional hazards, the relative risk of death was calculated for nonepithelial cell type (OR 3.0, CI 2.0-4.5; P <.0001), positive resection margins (OR 1.7, CI 1.2-2.6; P =.0082), and metastatic extrapleural nodes (OR 2.0, CI 1.3-3.2; P =.0026). Thirty-one patients with 3 positive variables had the best survival (68% 2-year survival, 46% 5-year survival, median 51 months; P =.013). A previously published staging system using these variables stratified survival (P <.05). CONCLUSIONS: (1) Multimodality therapy including extrapleural pneumonectomy is feasible in selected patients with malignant pleural mesotheliomas, (2) pre-resectional evaluation of extrapleural nodes may select patients for radical therapy, (3) microscopic resection margins affect long-term survival, highlighting the need for further investigation of locoregional control, and (4) patients with epithelial, margin-negative, extrapleural node-negative resection had extended survival.

High-risk bronchoscopy.

Fiberoptic bronchoscopy may be performed in patients with acute respiratory distress after thoracic surgical procedures as a measure to avoid intubation and subsequent positive-pressure ventilation in a patient with mucous impaction or as a method of intubating in a patient with a difficult airway. We describe the indications, the technique, and the potential complications.

Contralateral pulmonary artery stenosis after left pneumonectomy.

Contralateral pulmonary artery stenosis is a rare complication following pneumonectomy. When extensive intrapericardial dissection is warranted, one must be wary of this potential complication and take measures to avoid it. Postoperatively, a high index of suspicion must be maintained in a patient with a new onset of right-sided heart failure after intrapericardial pneumonectomy. We discuss intraoperative risk factors, postoperative clinical findings, and our strategy for repair.