Foetal haemoglobin elevation, unfavourable prognosis, and protective role of genetic variants HBG2 rs7482144, HBS1L-MYB rs9399137 and BCL11A rs4671393 in children with ALL.

In acute lymphoblastic leukaemia (ALL), elevated foetal haemoglobin (HbF) levels have been associated with the prognosis of patients. Genetic variants in HbF regulatory genes: BAF chromatin remodelling complex subunit (BCL11A), HBS1L-MYB transcriptional GTPase intergenic region (HBS1L-MYB), Krüppel-like factor 1 (KLF1), haemoglobin gamma subunit 2 (HBG2), haemoglobin gamma subunit 1 (HBG1), and haemoglobin subunit beta pseudogene 1 (HBBP1) are often associatedwith elevatedHbF concentration. This study investigated the association of genetic variants in HbF regulatory genes with HbF concentration, unfavourable prognosis, and outcome in children with ALL.We quantified HbF concentration and genotyped 17 genetic variants in 48 patients with ALL and 64 children without ALL as a reference group. HbF concentrationwas higher in patients than in the reference group (4.4%vs 1.4%), and 75%(n = 36) of thepatientshadHbF>2.5%.Unfavourable prognosis ALL was established in 68.8% (n = 33) of the patients. Variant HBG2 rs7482144 was associated with high HbF concentration (P = 0.015); while HBS1L-MYB rs9399137 (P = 0.001), HBG2 rs7482144 (P = 0.001) and the ß-globin genes HBG2, HBG1, and HBPP1 haplotypeTGC(P = 0.017) with unfavourable prognosisALL.Additionally, variantBCL11A rs4671393 showed a protective role (P = 0.0001). In conclusion, variants HBG2 rs7482144, HBS1L-MYB rs9399137 and BCL11A rs4671393 may play a significant role in ALL.

The Genetic Variant TNFA (rs361525) Is Associated with Increased Susceptibility to Developing Dengue Symptoms.

Dengue virus (DENV) is the causal agent of dengue fever. The symptoms and signs of dengue vary from febrile illness to hemorrhagic syndrome. IFITM3 and TNFA are genes of the innate immune system. Variants IFITM3 (rs12252 T>C) and TNFA (rs1800629 G > A and rs361525 G>A) might alter gene expression and change the course of the disease. Our first objective was to determine whether these variants were associated with the susceptibility and severity of dengue. The second was to assess the association of these variants with each symptom. We studied 272 cases with suspected dengue infection, of which 102 were confirmed dengue cases (DENV+) and 170 were dengue-like cases without DENV infection (DENV-). Samples of 201 individuals from the general population of Mexico were included as a reference. Genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism technique. Odds ratios and confidence intervals were calculated using Pearson's chi-square test and later adjusted for age and sex with a binary logistic regression model. Haldane correction is applied when necessary. We found a significantly higher frequency of the A allele of TNFA rs361525 in both the DENV+ and DENV- groups compared with the general population. Focusing on DENV+ and DENV-, the frequency of the A allele of TNFA rs361525 was higher in the DENV+ group. A broad spectrum of symptoms was related to the A allele of both TNFA variants. We conclude that TNFA rs361525 increases the susceptibility to symptomatic dengue but can also be associated with susceptibility to other dengue-like symptoms from unknown causes.

Association of the rs8720 and rs12587 KRAS Gene Variants with Colorectal Cancer in a Mexican Population and Their Analysis In Silico.

Colorectal cancer (CRC) is a major global health challenge and one of the top 10 cancers in Mexico. Lifestyle and genetic factors influence CRC development, prognosis, and therapeutic response; identifying risk factors, such as the genes involved, is critical to understanding its behavior, mechanisms, and prognosis. The association between KRAS gene variants (rs8720 and rs12587) and CRC in the Mexican population was analyzed. We performed in silico analysis and analyzed 310 healthy individuals and 385 CRC patients using TaqMan assays and real-time PCR. The CC and GG genotypes of rs8720 and rs12587 were identified as CRC risk factors (p < 0.05). The CC and TC genotypes of the rs8720 were associated with rectal cancer, age over 50 years, moderately differentiated histology, and advanced cancer stage. TG and GG genotypes of the rs12587 variant were a risk factor in the CRC group, in patients with stage I-II, males, and stage III-IV non-chemotherapy response. The TG haplotype is protected against CRC. The combined CCGG genotype was linked to CRC risk. In silico analysis revealed that the rs12587 and rs8720 variants could influence KRAS gene regulation via miRNAs. In conclusion, rs8720 and rs12587 variants of the KRAS gene were associated with CRC risk and could influence KRAS regulation via miRNAs.

Presence of HPV DNA in placenta and cervix of pregnant Mexican women.

PURPOSE: To identify the presence of HPV DNA in cervical as well as in placental tissue of pregnant Mexican women and to determine which type is more frequent. METHODS: In a cross-sectional study, 56 placental samples were obtained from 72 pregnant women. HPV DNA was extracted and amplified with polymerase chain reaction using a consensus primer and then identified by type using RsaI endonuclease. The main outcome measures were placenta with/without HPV relation and HPV types in placenta. RESULTS: HPV DNA was identified in 75% of cervical tissue samples and 47.2% of placental tissue samples. Type 18 was the most frequently identified HPV type. CONCLUSIONS: There was a higher frequency of HPV DNA found in the cervix of Mexican women during pregnancy than reported in the previous studies. Its identification in full-term placental tissue has no relation to the type of delivery in childbirth.

The Alpha Variant (B.1.1.7) of SARS-CoV-2 Failed to Become Dominant in Mexico.

During the coronavirus disease 2019 (COVID-19) pandemic, the emergence and rapid increase of the B.1.1.7 (Alpha) lineage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first identified in the United Kingdom in September 2020, was well documented in different areas of the world and became a global public health concern because of its increased transmissibility. The B.1.1.7 lineage was first detected in Mexico during December 2020, showing a slow progressive increase in its circulation frequency, which reached its maximum in May 2021 but never became predominant. In this work, we analyzed the patterns of diversity and distribution of this lineage in Mexico using phylogenetic and haplotype network analyses. Despite the reported increase in transmissibility of the B.1.1.7 lineage, in most Mexican states, it did not displace cocirculating lineages, such as B.1.1.519, which dominated the country from February to May 2021. Our results show that the states with the highest prevalence of B.1.1.7 were those at the Mexico-U.S. border. An apparent pattern of dispersion of this lineage from the northern states of Mexico toward the center or the southeast was observed in the largest transmission chains, indicating possible independent introduction events from the United States. However, other entry points cannot be excluded, as shown by multiple introduction events. Local transmission led to a few successful haplotypes with a localized distribution and specific mutations indicating sustained community transmission. IMPORTANCE The emergence and rapid increase of the B.1.1.7 (Alpha) lineage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) throughout the world were due to its increased transmissibility. However, it did not displace cocirculating lineages in most of Mexico, particularly B.1.1.519, which dominated the country from February to May 2021. In this work, we analyzed the distribution of B.1.1.7 in Mexico using phylogenetic and haplotype network analyses. Our results show that the states with the highest prevalence of B.1.1.7 (around 30%) were those at the Mexico-U.S. border, which also exhibited the highest lineage diversity, indicating possible introduction events from the United States. Also, several haplotypes were identified with a localized distribution and specific mutations, indicating that sustained community transmission occurred in the country.

Molecular Identification of Human Papillomavirus DNA in Thyroid Neoplasms: Association or Serendipity?

BACKGROUND: Human papillomavirus (HPV) is recognized as the most important cofactor in the etiology of cancers of the cervix, esophagus, larynx, and nasopharynx. Experimental evidence suggests that HPV could have an oncogenic influence on thyroid follicular cells; however, to the best of our knowledge, there is no record of its role in human thyroid gland neoplasms. OBJECTIVE: The purpose of this study is to describe the frequency and the types of HPV present in neoplastic thyroid tissue by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). METHODS:  Over 157 samples were analyzed of paraffin-embedded tissue from malignant and benign thyroid tumors. All the paraffin blocks were selected consecutively from the Pathology Tissue Bank archive of the Western Medical Center. The molecular detection and typing were performed at the Molecular Microbiology Laboratory of the Biomedical Research Center, Mexican Institute of Social Security. RESULTS:  The frequency of HPV findings was 2.5% (four cases). HPV-6 was found in two cases of thyroid hyperplasia (2.5%), and HPV-33 in two cases of papillary cancer (4.6%). CONCLUSION: The presence of HPV is not frequent in thyroid neoplasms, at least in the studied population. Due to the low prevalence of this virus in our sample, it is not possible to reach conclusions. Further research is needed.

Molecular Detection and Typing of Human Papillomavirus in Men from Northwestern Mexico.

BACKGROUND: A few studies of Human Papillomavirus (HPV) distribution and frequency have shown a real context of infection in men. The study aimed to know the HPV types distribution in men from Northwestern Mexico, in general, per age and year. METHODS: A total of 1,769 males were recruited from 5 years (2011-2015), from an HPV PCR testing laboratory service. Penile scraps from urethral meatus and coronal sulcus were taken for DNA isolation. There were detected 32 high and low-risk HPV types by HPV Type 3.5 LCD-Array system. RESULTS: A high frequency of HPV-6 and HPV-66 and a reduced frequency of HPV-18 and HPV-11 was detected. Young men had a high risk of HPV infection regarding men aged 40 years and older. The theoretical coverage for the HPV vaccine in men was calculated, where the bivalent vaccine showed coverage of 21.66% in high-risk HPV positive cases. CONCLUSION: The men from Northwestern Mexico have a different distribution of high and low-risk HPV types and high risk of HPV infection in younger men, with a theoretical coverage for HPV bivalent vaccine of 1 of 10 positive men for any HPV type.

[Prevalence and cervical human papilloma virus associated factors in patients with rheumatoid arthritis]. / Prevalencia y factores asociados con infección por virus del papiloma humano cervical en pacientes con artritis reumatoide.

BACKGROUND: Nevertheless its association with cervicouterine cancer, there is no information about cervical human papillomavirus infection prevalence in patients with rheumatoid arthritis. OBJECTIVE: To evaluate human papillomavirus infection prevalence through molecular biology tests, and to analyze this infection related factors in patients with rheumatoid arthritis. MATERIAL AND METHOD: Analytic, transversal study to 250 patients: 61 women with rheumatoid arthritis selected from a rheumatologic external consult of a second level hospital, and 189 healthy women, with cervical cytology, of a first level hospital. They were polled to find infection risk factors. They were exfoliated to get cervix cells to extract its DNA and detect human papillomavirus (chain reaction of polymerase with specific consensus markers), and identification of restriction enzyme in high and low risks viruses. Prevalence was calculated, and adjusted factors analysis was performed through logistic regression with odds ratio and confidence intervals of 95%. RESULTS: Prevalence of papillomavirus infection in patients with rheumatoid arthritis was 30%, and in control group was 24%, with an odds ratio of 0.8 (CI 95% 0.42-1.6, p = 0.5). Ninety-four percent of the most frequent viral types in women with rheumatoid arthritis were high risk (mainly types 16, 58, and 18). Factors associated with higher human papillomavirus adjusted to rheumatoid arthritis were: more than one sexual partner (OR = 5.8 CI 95% 1.1-31.1, p = 0.04), more than one sexual intercourse weekly (OR = 6.7, CI 95% 0.9-51.6, p = 0.06), circumcised sexual partner (OR = 9.0, CI 95% 1.2-64.4, p = 0.02). Patients and controls had same values of marital status. Seventy-four percent of controls worked, compared to 44% of women with rheumatoid arthritis (p < 0.01). CONCLUSION: One out of three women with rheumatoid arthritis has human papillomavirus infection and 94% has the high-risk viral type. Infection associated factors mainly includes sexual partner ones; due to high risk of cervical dysplasia, it is necessary the early detection of the infection and surveillance.

Association of RETN and CAP1 SNPs, Expression and Serum Resistin Levels with Breast Cancer in Mexican Women.

BACKGROUND: Breast cancer is the most common cancer in women worldwide. Approximately 70% of female breast cancer patients have a body mass index (BMI) >25. In obesity, adipose tissue secretes additional resistin, which prompts a proinflammatory effect through its action on adenylate cyclase-associated protein 1 (CAP1). Several studies have associated the RETN gene single nucleotide polymorphism (SNP) rs1862513 (-420C

Amylin S20G mutation in Mexican population.

Diabetes Mellitus type 2 (DM2) is a group of metabolic disorders characterized by defective insulin action or secretion or both with a 10.6% incidence in Mexican Mestizo population, DM2 is also classified within the localized misfolding diseases due to the amyloid pancreatic deposits found in 90% of the DM2 necropsies. The pancreatic amyloid main component is a protein known as human islet amyloid polypeptide (hIAPP) or amylin, the most common mutation is the S20G in Asian population with a polymorphic frequency in DM2 Asian patients. The aim of this study was to search this mutation in Mexican Mestizo general population (104) and DM2 patients (100). This is the first molecular study of hIAPP gene in Mexican population and in which we developed an alternative more effective antisense primer for the analysis of the NFGAILSS region in hIAPP exon 3 critical for the amyloid beta structure formation. We did not find the mutation in any of the 204 analyzed samples, thus the findings show that S20G is not a common mutation in Mexican Mestizo population.

Genetic polymorphisms of the renin-angiotensin system in preterm delivery and premature rupture of membranes.

INTRODUCTION: Premature rupture of membranes (PRM) is a late pregnancy complication commonly associated with preterm delivery (PD). Although several markers related to the renin-angiotensin system (RAS) have been evaluated in certain pregnancy complications, only the angiotensin-converting enzyme (ACE) I/D variant has been studied in PD-PRM. The aim of this survey was to investigate the association of the polymorphisms (angiotensin II type 1 [AT1] receptor T174M and M235T, renin G2805A, ACE I/D and AT1-receptor A1166C) of the genes of RAS in women with PD-PRM. DESIGN: Deoxyribonucleic acid samples from 89 Mexican Mestizo women with PD and PRM and 224-288 controls were studied. Polymorphisms were analysed by polymerase chain reaction-restricted fragment length polymorphism or sequence specific primer assays. RESULTS: For all loci, genotype distribution was in agreement with Hardy-Weinberg expectations in the control group. Significant intergroup difference (case vs. control) was seen for angiotensinogen (AGT) M235T polymorphism, with an increased allele M235 in affected cases (50% vs. 40% in controls). Analysis of two-locus haplotype agrees with an independent segregation of physically unlinked genes. Haplotype AGT 174T-235M was also increased (50% vs. 40% in controls). CONCLUSIONS: Physically unlinked genes involved in RAS segregate independently. The AGT 174-235 region is associated with PD-PRM in this population.

[Cervical-uterine-cancer associated factors in Nayarit state, Mexico]. / Factores relacionados con el cáncer cervicouterino en el estado de Nayarit, México.

OBJECTIVE: To establish the association between high-grade intraepithelial lesions and cervical-uterine-cancer, and the infection by human papillomavirus, genetic antecedents, socioeconomics, sexual behavior and gynecology and obstetrics factors in women of the State of Nayarit, Mexico. MATERIALS AND METHODS: With a case-control design were studied 66 cases of high-grade intraepithelial lesions and cervical-uterine-cancer, and 132 controls. The information upon the risk factors was obtained by the application of a structured questionnaire. Polymerase Chain Reaction executed the virus identification. In the statistical analysis the association was obtained by odds ratio. The statistical significance was evaluated by the chi-square-Fisher and Student t tests, and multivariate logistic regression was used to explain the factors' influence. RESULTS: In women with high-risk squamous intraepithelial lesions and cervical-uterine-cancer, the most frequently high-risk human papillomavirus found were: 18, 35, 58, 16, 31, 33 and 51. CONCLUSIONS: Familial data of cervical-uterine-cancer, socioeconomic level, number of sexual partners, data of sexual transmitted diseases, and infection due to human papillomavirus 18 and 35 are the factors related to high-risk squamous intraepithelial lesions and cervical-uterine-cancer.

Association of the Del1518 Promoter (rs3730485) Polymorphism in the MDM2 Gene with Breast Cancer in a Mexican Population.

INTRODUCTION: The MDM2 gene plays an important role in tumorigenesis. The data on the Del1518 promoter polymorphism in the MDM2 gene have revealed associations with cancer. MATERIAL AND METHODS: We examined the role of the MDM2 Del1518 polymorphism through a comparison of the genotypes of 345 healthy Mexican women with those of 742 Mexican women with breast cancer (BC). RESULTS: The genotype frequencies of the MDM2 Del1518 polymorphism in controls and patients with BC were 64% and 55.5% for ins/ins, 32% and 31.5% for ins/del, and 4% and 13% for del/del, respectively. The obtained odds ratio (OR) was 3.26, with a 95% confidence interval (95% CI) of 1.86-5.72 and p=0.0001, for the del/del genotype. An association was evident when we examined the distribution of the del/del genotype in patients with elevated levels of transaminase SGPT (OR=2.268; 95% CI=1.40-3.65; p=0.0001). Additionally, we observed an association of the genotypes del/del - ins/del in menopausal patients with BC with the following characteristics: tobacco consumption (OR = 1.93, 95% CI = 1.07-3.4, p=0.025), pregnancy loss (OR=2.44, 95% CI=1.37-4.35, p=0.0024), obesity (I-IV) (OR=1.8, 95% CI=1.1-2.9, p= 0.018), and elevated serum glucose levels (OR=3.72, 95% CI=2.0-6.85, p=0.0001). CONCLUSIONS: The MDM2 Del1518 polymorphism was associated with BC susceptibility, particularly in menopausal patients with BC who reported tobacco consumption, pregnancy loss, obesity and high glucose levels in the analyzed Mexican population.

Human papillomavirus DNA and protein in tissue samples of oesophageal cancer, Barrett's oesophagus and oesophagitis.

BACKGROUND: The risk of presenting with oesophageal cancer is associated with Barrett's oesophagus, with a higher prevalence in some Asian and African countries. Human papillomavirus (HPV) DNA has been identified in oesophageal carcinomas, which share common features with cervical cancers and originate in stratified epithelium. MATERIALS AND METHODS: Sixty-eight paraffin-embedded tissue biopsies were selected from Mexican patients: 17 from oesophageal cancers, 28 from cases of Barrett's oesophagus and 23 from cases of oesophagitis. HPV protein was detected immunohistochemically and the presence and types of HPV DNA were assessed by polymerase chain reaction. RESULTS: HPV DNA-positive results were found in 26% of samples of oesophagitis, 96% of samples of Barrett's oesophagus and 88% of samples of oesophageal cancers. HPV viral types 6 and 11 were prevalent. HPV protein was detected in 41 samples (60%). CONCLUSION: Mexico has a high prevalence of HPV in premalignant and malignant oesophageal diseases compared with other countries.

Identification of DNA sequences and viral proteins of 6 human papillomavirus types in retinoblastoma tissue.

PURPOSE: To detect DNA and proteins of human papillomavirus (HPV) in paraffin-embedded retinoblastoma (RB) tissue, to identify the viral types present and to describe a possible association between the presence of HPV and a particular form of RB. MATERIALS AND METHODS: Fifty-one samples from ocular tissues of RB patients and of six controls enucleated for non-neoplastic reasons were obtained and analyzed by Polymerase Chain Reaction (PCR) with consensus primers to detect HPV. Viral type identification was performed by Restriction Fragment Length Polymorphisms (RFLP) analysis. To corroborate the presence of HPV, immunohistochemical analysis with a polyclonal anti-HPV antibody was performed in 10 RB cases and in all controls. RESULTS: Forty-two (82.3%) of the 51 samples were HPV-positive. HPV 6 was detected in 40 cases (95.2%), HPV 33 in 16 (38.1%), HPV 11 in 4 (9.5%) and HPV 31, 35 and 51 each in one case (2.3%). All controls were negative for HPV-DNA. The positive samples were PCR-tested for HPV 16 and 18 using specific primers, and were all negative. For immunohistochemical analysis, 7 out of 10 PCR-positive samples randomly chosen were positive; all six controls were negative. CONCLUSION: No differences in the HPV type distribution were found between the groups formed according to the tumor presentation or to the mode of inheritance.

[Polymorphism in codon 72 of the p53 gene and cervico-uterine cancer risk in Mexico]. / Polimorfismo en el codón 72 del gen p53 y riesgo de cáncer cérvico-uterino en México.

A polymorphism at codon 72 in the p53 gen has been reported as a potential risk factor to cervical cancer (CC) because human papillomavirus (HPV) is more effective at degrading p53 Arg-72 than p53 Pro-72, making individuals homozygous for p53 Arg-72 seven times more likely to develop HPV-associated CC. As In Mexico the CC is a health public problem, we designed this study to determinate whether the p53 codon 72 polymorphism represent a risk factor to CC in our population. A case-controls study was performed. DNA was obtained from paraffin-embedded cervical fixed tissue samples. Analysis of the p53 genotype at position 72 was performed by polymerase chain reaction using specific primers and Accll digestion. Among cases with CC the proportions of the p53 genotypes at codon 72 were 0.05 to proline homozygous, 0.5 to heterozygous, and 0.45 to arginine-homozygous. In controls the proportions were 0.08, 0.62, and 0.31. X2 test showed no significant difference In the proportions. We conclude than In our population, as other worldwide countries, the homozygous for arginine at codon 72 of the p53 gene is not a risk factor to cervical cancer.

[Squamous intra-epithelial lesions in HIV seropositive females. Their frequency and association with cervical neoplasia risk factors]. / Lesiones escamosas intraepiteliaes en pacientes VIH seropositivas. Su frecuencia y asociación con factores de riesgo para neoplasia cervical.

OBJECTIVE: Determining the prevalence of squamous intraepithelial lesions (SIL), and their association with known cervical neoplasia risk factors in seropositive HIV female patients. MATERIALS AND METHODS: A transversal study including 50 seropositive HIV female patients was carried out. The patients were interrogated concerning known cervical neoplasia risk factors. Cervical cytology tests and colposcopic evaluations of the lower genital tract, with directed biopsies, were carried out. The presence of HPV-DNA was investigated using the polymerase chain reaction and CD4 and CD8 T lymphocyte titers were determined. Two comparison groups were formed, in accordance to the presence or absence of cervical lesions. RESULTS: Average age was 36 +/- 9.3 years, ranging from 20 to 61 years, 26% had never submitted to a cervical cytology test, and an average of 33 months (1-130 months) had elapsed after the last test of those who had. HIV transmission had been sexual in 72% of the cases, and the period of time elapsed since the infection was diagnosed and until the patients were evaluated for this study was of 40.6 +/- 33.5 months. HPV-DNA was detected in 64% (n = 32) of the patients, and co-infection with more than one HPV was detected in 42% of them, with the 16 and 31 types being the most frequent. A cervical lesion was diagnosed in 52% of the cases, 18% being of high degree and 34% of low degree. When risk factors for cervical neoplasia and lymphocyte titers were compared between group I (with SIL, n = 26), and group II (without SIL, n = 24), the only significant differences found were the presence of HPV-DNA and the co-infection with more than one type of HPV, which were more frequent in group I. Sexual transmission of HIV was also more frequent in group I. The presence of vaginal and vulvar synchronous lesions was determined in 20% and 12% of the cases, respectively. CONCLUSIONS: There is a high prevalence of positive DNA-HPV and SIL in seropositive HIV patients, which pose them in a higher risk of developing invasive cervical cancer. Thus, creating adequate strategies for the detection, diagnosis, management, and follow-up of these patients is of the utmost importance.

Human papillomavirus genotypes among females in Mexico: a study from the Mexican institute for social security.

BACKGROUND: The aetiological relationship between human papillomavirus (HPV) infection and cervical cancer (CC) is widely accepted. Our goal was to determine the prevalence of HPV types in Mexican women attending at the Mexican Institute for Social Security from different areas of Mexico. MATERIALS AND METHODS: DNAs from 2,956 cervical samples were subjected to HPV genotyping: 1,020 samples with normal cytology, 931 with low-grade squamous intraepithelial lesions (LGSIL), 481 with high grade HGSIL and 524 CC. RESULTS: Overall HPV prevalence was 67.1%. A total of 40 HPV types were found; HPV16 was detected in 39.4% of the HPV-positive samples followed by HPV18 at 7.5%, HPV31 at 7.1%, HPV59 at 4.9%, and HPV58 at 3.2%. HPV16 presented the highest prevalence both in women with altered or normal cytology and HPV 18 presented a minor prevalence as reported worldwide. The prevalence ratio (PR) was calculated for the HPV types. The analysis of PR showed that HPV16 presents the highest association with CC, HPV 31, -33, -45, -52 and -58 also demonstrating a high association. CONCLUSIONS: The most prevalent HPV types in cervical cancer samples were -16, -18, -31, but it is important to note that we obtained a minor prevalence of HPV18 as reported worldwide, and that HPV58 and -52 also were genotypes with an important prevalence in CC samples. Determination of HPV genotypes is very important in order to evaluate the impact of vaccine introduction and future cervical cancer prevention strategies.

Renin gene haplotype diversity and linkage disequilibrium in two Mexican and one German population samples.

INTRODUCTION: Renin is the main rate-limiting enzyme in the renin-angiotensin-aldosterone system. Its gene, REN, is a candidate crucial factor in essential hypertension and cardiovascular disease. The aim of this study was to evaluate allele and haplotype distributions of REN polymorphisms, and to estimate normalised linkage disequilibrium (D') in Mexican and German populations. MATERIALS AND METHODS: Four groups were studied for the REN single nucleotide polymorphisms (SNPs) 1205C>T, 1303G>A, and 10607G>A, in population samples of Mexican Mestizo (n = 86), Mexican Huichol (n = 49), German (n = 39), and individuals with hypertension diagnosis (n = 66). Polymorphisms were detected by PCR-RFLP. Genotype, allele and haplotype frequencies were estimated. RESULTS: SNP 1205C>T and 10607G>A allele and genotype distribution showed inter-group differences. The 1205T and 10607A allele showed a significance difference in hypertensive population. Haplotype analysis also showed some inter-group differences, especially in 1205C-1303G-10607G, 1205C-1303G-10607A and 1205T-1303G-10607G haplotypes. The segregation analysis disclosed complete linkage disequilibrium between 1205 and 1303 loci. CONCLUSION: These results provide an example of genetic diversity in related populations and illustrate the convenience of increasing the number of loci in associative studies between diseases and candidate genes.

Deteccion de Mycobacterium tuberculosis mediante la reaccion en cadena de la polimerasa en una poblacion seleccionada del noroccidente de Mexico / Detection of Mycobacterium tuberculosis with polymerase chain reaction in a selected population in northwestern Mexico

Este estudio compara la detección de Mycobacterium tuberculosis mediante baciloscopia (tinción de Ziehl-Neelsen), cultivo en medio de Löwenstein-Jensen y reacción en cadena de la polimerasa (RCP) realizada con ADN extraído directamente de distintos tipos de muestras. Se analizaron 252 muestras (114 de esputo, 96 de orina, 15 de LCR y 27 de otros tipos) de 160 pacientes con sospecha de tuberculosis en cualquiera de sus formas que acudieron al Laboratorio de Patología Clínica del Hospital de Especialidades del Centro Médico Nacional de Occidente del Instituto Mexicano del Seguro Social. En todos los casos se realizó tinción de Ziehl-Neelsen, cultivo en medio de Löwenstein-Jensen y amplificación por RCP de un segmento de 285 pares de bases específico del complejo M. tuberculosis. De las 252 muestras, 18 fueron positivas para micobacterias no tuberculosas en el cultivo. De las 234 restantes, 12 (5,1 por ciento) fueron positivas en la RCP y el cultivo, 174 (74,4 por ciento) negativas en ambas pruebas, 47 (20,1 por ciento) positivas en la RCP y negativas en el cultivo y 1 (0,4 por ciento) negativa en la RCP y positiva en el cultivo; tomando el cultivo como prueba de referencia, la RCP proporcionó una sensibilidad de 92,3 por ciento, una especificidad de 78,7 por ciento, un valor predictivo positivo de 20,3 por ciento y un valor predictivo negativo de 99,4 por ciento. El límite de detección de la RCP en ADN extraído de cultivo fue de 10 fg (equivalente a 4 o 5 micobacterias). También en comparación con el cultivo, la RCP identificó correctamente a la totalidad de las micobacterias del complejo M. tuberculosis. Tomando como prueba de referencia el cultivo, al analizar únicamente las muestras de esputo, la RCP directa proporcionó una sensibilidad de 90,9 por ciento, una especificidad de 89,5 por ciento, un valor predictivo positivo de 52,6 por ciento y un valor predictivo negativo de 98,7 por ciento. La RCP es una técnica sensible y específica para detectar el complejo M. tuberculosis en muestras tanto positivas como negativas en la baciloscopia. Un procedimiento controlado de RCP permite establecer o excluir el diagnóstico de tuberculosis en un tiempo que se reduce de más de tres semanas a tan solo 24 a 48 horas, lo cual resulta particularmente útil cuando es necesario un diagnóstico temprano para establecer el pronóstico del paciente o en casos de transplante de órganos