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The aim of this study was to determine the presence of Helicobacter pylori cytotoxin-associated gene (cagA)/vacuolating cytotoxin gene (vacA) among patients with chronic gastritis in Cuba and Venezuela. Gastric antrum biopsies were taken for culture, DNA extraction and PCR analysis. Amplification of vacA and cagA segments was performed using two regions of cagA: 349 bp were amplified with the F1/B1 primers and the remaining 335 bp were amplified with the B7629/B7628 primers. The VA1-F/VA1-R set of primers was used to amplify the 259-bp (s1) or 286-bp (s2) product and the VAG-R/VAG-F set of primers was used to amplify the 567-bp (m1) or 642-bp (m2) regions of vacA. cagA was detected in 87% of the antral samples from Cuban patients and 80.3% of those from Venezuelan patients. All possible combinations of vacA regions were found, with the exception of s2/m1. The predominant combination found in both countries was s1/m1. The percentage of cagA+ strains was increased by the use of a second set of primers and a greater number of strains was amplified with the B7629/B7628 primers in the Cuban patients (p = 0.0001). There was no significant difference between the presence of the allelic variants of vacA and cagA in both populations. The predominant genotype was cagA+/s1m1 in both countries. The results support the necessary investigation of isolates circulating among the human population in each region.

The aim of this study was to establish the presence of HPV infection in cervical lesions in a Venezuelan population, by Hybrid Capture Assay II (HCA II), and its association with cytological diagnosis. The study included 1483 cervical samples analysed at Laboratorios CITOMED, Caracas, Venezuela, from 2005 to 2007. The woman age range was between 20 and 58 years, and the mean age was 28.8. HPV infection was determined using HCA II. The cytological diagnosis of the smears showed LSIL in 1120/1483 samples (75.5%), HSIL in 354/1483 (23.9%) and ASC-US, in 9/1483 (0.6%). The positivity of HPV DNA detected by HCA II was 54.6% (811/1483). Of the positives cases, 138/811 (17%) presented HPV DNA of low oncogenic risk and 673/811 (82.9%) had high-risk HPV. There were significant differences in the low and high oncogenic HPV type frequencies of the evaluated samples (p > 0.0001). Low risk HPV types were detected in 127 cases of LSIL, 9 of HSIL and 2 of ASC-US. High-risk HPV was detected in most of the cases: 361 LSIL, 308 HSIL and 4 ASC-US. Our study showed a high presence of cervical infection by human papillomavirus of a high risk genotype. Our results contribute to the epidemiological data that report diversity in the prevalence rates in different countries.

Objective: The objective of this study was to analyze the expression of proliferative markers and p53 in keratocystic odontogenic tumor (KCOT) sporadic type and KCOT associated with nevoid basal cell carcinoma syndrome (NBCCS)., Study Design and Setting: We performed a cross-sectional study. A total of 19 patients with KCOT were selected from the Oral Pathology Laboratory archives, Central University of Venezuela, from 1995 to 2005., Subjects and Methods: Twelve cases corresponded to sporadic KCOT, and seven cases were associated with NBCCS. Immunohistochemical analysis for p53, proliferating cell nuclear antigen (PCNA), and Ki-67 was performed in all 19 cases., Results: Of the seven cases associated with NBCCS, six (86%) were positive for PCNA. From the 12 sporadic cases, nine (75%) were positive for PCNA. Only one case of sporadic KCOT showed Ki-67 positivity. Five of 12 (42%) cases of sporadic KCOT were positive for p53, and only one (14%) case associated with NBCCS was positive for p53., Conclusion: On the basis of the analysis of the expression of PCNA, Ki-67, and p53, there appears to be no evidence to indicate higher aggressiveness in growth and infiltrative behavior in syndromic KCOT compared with the sporadic type. Therefore, surgical treatment may be approached in the same manner in KCOT sporadic and syndromic with the goal of minimizing recurrence., (Copyright 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. Published by Mosby, Inc. All rights reserved.)

Oral hairy leukoplakia (OHL) is commonly found in individuals infected with HIV and represents the most frequent oral manifestation. The purpose of this study was to detect the presence of Human Papillomavirus (HPV) and Epstein Barr Virus (EBV) in OHL of HIV+ Venezuelan patients. We evaluated 21 HIV+ adult patients with clinically present OHL lesions: 11 under antiretroviral therapy, 10 without therapy, and 10 oral mucosal samples as controls. Nested-PCR was used to detect EBV and HPV infection. The INNO-LiPA HPV Genotyping v2 was applied to determine the HPV genotype. The EBV genome was found in 16/21 (76%) of the HIV+ patients with OHL. No difference was observed in EBV+ and EBV- patients related to antiretroviral therapy viral load and CD4+ Tcell coant. HPV-DNA was observed in 7/21 HIV positive cases (33%). The HPV genotypes detected were: 6, 11, 31, 33, 52, and 56/74. The most frequently HPV found was genotype 6 in 7/7, while two cases were HPV-11 and two HPV-52. Of the positive cases, 5/7 (71%) presented co-infection with more than one HPV genotype and 4/7 (57%) had HPV coinfection with high and low risk types. No case was EBV or HPV positive in the control group. In this study, a higher EBV prevalence was observed in OHL-HIV+ patients, confirming the etiologic role in this entity. A considerable number of cases were positive for HPV infection, and many patients presented coinfection with more than one HPV genotype as well as the presence of high oncogenic risk HPV in OHL.

The aim of this work was to analyze diagnosed cases of Oral Cancer (OC) and Oropharyngeal Cancer (OPC) in a Venezuelan population. We clinically evaluated 130 patients with OC and OPC and a histopathologic diagnosis of squamous cell carcinoma. The patients were analyzed according to gender age, and use of alcohol and tobacco and the tumors were classIfied based on anatomic location, staging parameters, and degree of difFerentiation. Ninety one patients (70%) were male and 39 (30%) were female. Patients' age ranged from 26 to 86 years old. Use of smoking tobacco, alcohol or both was reported by 84.3%, 49.1% and 45.4% of patients, respectively, and was more frequent in males. The most common oropharyngeal anatomic location was the base of the tongue (22.3%), followed by the tonsils (13.9%), while the most frequently affected oral location was the oral tongue (19.2%) followed by the gingiva and alveolar mucosa (10.8%), and the floor of mouth (7.7%). The majority of tumors (77.7%) were diagnosed at an advanced stage (Stage III or IV); metastasis to the regional lymph nodes occurred in 53.1% of cases. According to degree of diferentiation, well, moderately and poorly difFerentiated tumors accounted for 45.4%, 46.1% and 8.5% of cases, respectively. Well differentiated tumors accounted for 56.7% of OC cases, while the majority of OPC cases were classified as moderately or poorly differentiated (72.3%) (p < or = 0.002). Also, non-metastatic cases (NO) showed a predominance of well-diferentiated tumors (61.2%), while metastatic tumors (N+) were classified as moderately or poorly differentiated in 89.8% of cases (p < or = 0.0001). Our study population was characterized by a predominance of smokers and/or drinkers and a predilection for male patients. Most tumors were diagnosed at an advanced stage with a high incidence of metastatic spread to the regional lymph nodes, indicating possible delays in diagnosis. Less differentiated tumors were more frequently encountered among OPC cases and accounted for the vast majority of metastatic cases, supporting the prognostic value of assessing the degree of difFerentiation.

The aim of this study was to determine the periodontal conditions and the distribution of Prevotella intermedia, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in a group of HIV-infected patients undergoing anti-retroviral therapy (HAART) and in an HIV-seronegative group. The study sample comprised thirty-two (32) HIV positive patients distributed in two groups (11 HIV+ without HAART and 21 HIV+ with HAART) and 16 HIV seronegative patients. Plaque index, gingival index, pocket depth, and clinical attachment level were evaluated at six sites per tooth in all teeth. Subgingival plaque samples were collected from one tooth per quadrant with pocket depth > 4 mm and attachment level > 5 mm. and then analyzed by PCR. The mean value of PI, GI, and CAL of the HIV-infected patients undergoing or not HAART- and the control group were similar the PD was higher in the control group. LGE was observed only in the HIV-infected group and NUP in the HIV+ without HAART therapy. The control group and the total HIV-infected patients showed similar CPG and CPL values. P. intermedia was the most frequently recovered microorganism in all the groups evaluated. The second pathogen with higher prevalence was A. actinomycetemcomitans, P. gingivalis was observed only in one (5%) HIV+ patient under HAART and in three patients (19%) in the control group. The periodontal indexes was not related with the CD4+ count and viral load. Changes observed in the periodontal tissues of patients infected with HIV are similar to those observed in HIV negative subjects.

Aim: To determine the prevalence of oral lesions in a HIV+ group of patients, related to CD4 cell count and viral load in a Venezuelan population., Materials and Methods: In the present study, we evaluated 75 HIV+ adult patients, attended at the Center of Infectious Diseases, at the Faculty of Dentistry, Central University of Venezuela. Each patient was clinically examined for detection of oral mucosal lesions. In addition, CD4 cell count was determined by flow cytometry, as well as viral load by RT-PCR (Amplicor HIV-RNA, TM test 1.5, Roche)., Results: 85% (64/75) of HIV/AIDS patients showed associated HIV lesions. Oral Candidiasis constituted the most common lesion representing a 61% (39/64), followed by Oral Hairy Leukoplakia 53% (34/64); Oral Leukoplakia 34% (22/64), Melanic Hyperpigmentation 38% (18/64); Papilloma 13 (6/64), Lineal Gingival Erythema 8% (5/64); Aphtous Recurrent Stomatitis 5% (4/64) and Kaposi's Sarcoma 5% (3/64). Only one case of the following lesions were represented by Non Hodgkin Lymphoma, Multifocal Epithelial Hyperplasia, Recurrent Herpes, Histoplasmosis and Molluscum Contagiosum. The patients with a viral load of 30.000 copies/mm3 exhibited oral lesions related with HIV, independent of CD4 cell count, although patients with CD4+ levels of 200 cel/mm3 were more susceptible to develop these lesions., Conclusions: The most common oral lesion was Oral Candidiasis followed by Oral Hairy Leukoplakia, Oral Leukoplakia and Melanic Hyperpigmentation. A high viral load was strongly associated to the oral lesions occurrence independently of CD4+ cell count.

This work evaluated the infection of H. pylori in the different gastric pathologies and its association with the oncogen K-ras 12. Endoscopy was performed in 62 patients and 3 biopsies from the antral region were taked and used for the histological diagnostic, PCR, and point mutations determination. The results showed a high incidence of H. pylori infection in patients with active chronic gastritis (AcCG) 90%, chronic atrophic gastritis (AtCG) 70%, intestinal metaplasia (IM) 67%, dysplasia (D) 83%, and decrease in in gastric cancer (GC) 33%. Evaluation of the oncogen K-ras 12 showed that 68% of the patients presented mutations in the different analyzed amino acids. In the 12 codon of the K-ras gene, we observed simple point mutations and combination in the same sample in different gastric pathologies. In AcCG samples were detected the greater number of mutations. A decrease of the point mutations were observed in the progression stages to gastric cancer. The presence of these specific mutations would be tumor markers and it determine the possible development of gastric tumors.

Helicobacter pylori is one of the most common bacterial infections worldwide. It is associated with chronic gastritis, peptic ulcer disease and constitutes a major risk factor for gastric adenocarcinoma and lymphoma. The aim of this study was to evaluate the specific serologic immunoglobulin G (IgG) response to whole cells proteins, CagA and urease antigens of Helicobacter pylori in a Venezuelan population. We evaluated 66 patients from the Hospital Universitario de Caracas, attending in the gastroscopy service. H. pylori infection was detected by culture and rapid urease test. IgG antibodies against, CagA and ureases were tested by enzyme-linked immunosorbent assay method using highly purified recombinant antigens. We demonstrated the presence of H. pylori in 48/66 (72.7%), by culture and rapid urease test. We found a seroprevalence of 45 (68%) to whole cells, 34/66 (51%) to CagA and 18/66 (27%) to urease. The positive rates of CagA antibodies in patients with gastric ulcer, gastric cancer and chronic gastritis were 87.8%, 77.7% y 40.8% respectively. The serum antibodies anti-CagA were similar between peptic ulcer disease and gastric cancer patients.

The purpose of this study was the evaluation of Helicobacter pylori infections in children and adults from two indigenous communities of Delta Amacuro State, Venezuela, that differ in hygienic conditions of the housing. The evaluation was performed in 98 children (mean age 7 +/- 3.37 years) and their mothers (33.96 +/- 13.77 years) from two communities of Warao lineage. Anti-H. pylori serum IgG and secretory anti-H. pylori IgA antibodies were determined, as well as total secretory IgA and H. pylori antigens in feces. Serological prevalence of H. pylori infection was 38% in children and 84% their in mothers. Children from the community that had the most deficient sanitary and hygienic conditions had significantly lower titers of specific IgG antibodies and total secretory IgA (P<0.0001) and a high percentage of them had H. pylori antigens in their feces (P<0.0001). The levels of specific IgA were similar in both groups. The results indicate that in these populations there is a high prevalence of H. pylori infection and that poor hygienic conditions can increase the risk of infection and damage to the gastrointestinal tract.

Dental plaque has been suggested as a reservoir for Helicobacter pylori but the hypothesis that the oral microflora may be a permanent reservoir of H. pylori is still controversial. The aims of this study were to determine the presence of H. pylori DNA in the gastric antrum and dental plaque of a Venezuelan population by PCR and to investigate the relationship between this infection and the oral hygiene index. Thirty-two patients from the Hospital Universitario de Caracas, attending for routine gastroscopy, and 20 asymptomatic subjects (control group) were evaluated. The patients' gingiva and plaque were assessed by the gingival and plaque indices of Sillness and Löe. Supragingival plaque was analysed by a PCR for a specific internal urease gene. Gastric antrum biopsies were taken for histological examination and PCR. H. pylori was detected in antral samples from 24 (75%) of 32 patients, all of whom had chronic gastritis. H. pylori was also detected in dental plaque samples of 12 (37.5%) of the 32 patients. In 7 (58%) of these 12 patients, H. pylori was identified in the gastric biopsy. Seven patients with chronic gastritis carried H. pylori in dental plaque and antral samples. Of these patients, four also had dysplasia and one had metaplasia. Three subjects in the control group were positive by PCR. In the present study there was no correlation between H. pylori infection and dental hygiene, dental caries, periodontal disease or use of dentures. The oral cavity may be a reservoir for H. pylori infection and oral secretions may be an important means of transmission of this micro-organism. H. pylori in dental plaque may represent a risk factor for gastrointestinal re-infection and ulcer relapse after antibiotic therapy.

Background: Current evidence suggests that immunological mechanisms are involved in oral lichen planus (OLP) pathogenesis. The events implicate activated epithelia that comprise antigen-presenting Langerhans cells, immunocompetent keratinocytes and subepithelial inflammatory infiltrate. Also, the presence of a high density of leucocyte cells may occur for the expression of a variety of adhesion molecules. The aim of this study was to analyse the immunoexpression of some adhesion molecules as well as lymphocytic markers in order to determine the disease pathogenesis in a Venezuelan population., Methods: The 18 OLP and 10 normal oral mucosa biopsies were immunostained for CD4, CD8, CD1a, LFA-1, VCAM-1 and ICAM-1., Results: The results showed an increased number of CD4+, CD8+, CD1a+ cells in OLP. Serial sections showed CD4+ and CD8+ cells also expressed LFA-1. The expression of ICAM-1 and VCAM-1 were significantly higher in OLP., Conclusions: The immunological reaction begins with Langerhans cells activation, which presents an antigen to CD4+ lymphocytes. Those cells through ICAM-1 and LFA-1 promote epithelial destruction. Afterwards, cytokine production, ICAM-1 and VCAM-1 expression can activate CD8+ lymphocytes leading to the chronic form of the disease.

Objectives: The general objective of the present study is to quantify antigalactosyl (alpha1 --> 3) galactose (anti-Gal) antibody levels in the cervical mucus of patients with/without human papillomavirus (HPV) infection and, as specific objectives, to compare these levels in the different HPV subgroups and with the presence of intraepithelial lesions., Methods: Sixty women between 18 and 35 years old (mean: 26 years) were studied through the following methods: vaginal cytology, colposcopy, biopsy of suspicious lesions, sample taking for evaluating HPV presence through PCR and hybridization, and quantification of anti-Gal levels using ELISA with laminin antigen extracted from the Engelbreth-Horm-Swarm cell line., Results: The presence of HPV was detected in 55% of patients; 45% of them had intermediate/high oncogenic risk HPV, 12% had low oncogenic risk HPV, and the other 43% had both subgroups. There were significantly higher anti-Gal levels in the HPV+ group when compared with the HPV- group (P < 0.0001); also, when dividing the HPV+ group into one subgroup with normal cytology and another with cervical intraepithelial neoplasia (CIN) 1, we found higher values in the latter group (P < 0.0001). There was no significant difference in anti-Gal levels in the various HPV subgroups., Conclusion: High anti-Gal levels are found in the cervical mucus of patients with HPV infection and CIN 1, which suggests the participation of local humoral immunity in cervical lesions.

Enzyme-linked immunosorbent assays (ELISA) have been developed to diagnose H. pylori infection. However, the methods are not standardized. We therefore evaluated the sensitivity of ELISA developed in our laboratory in a study population comprising 38 patients with dyspeptic symptoms and 41 healthy children under 10 years. The assays for immunoglobulin G used a pool of sonicated isolates of H. pylori from five patients with dyspeptic symptoms. Serum levels IgG antibodies to cell sonicates of H. pylori were significantly higher (p < 0.001) in patients with positive culture than in the control group. Cutoff score of 0.231 for positive results was determined with mean + 3ds of the healthy group analyzed. On the basis of this survey, we conclude that a serum dilution of 1:300 and 5 micrograms/ml of antigen, are the optimal condition for rapid screening with high sensitivity of 92% of symptomatic patients for the presence of H. pylori.

In the present work we obtained three mAbs specific against gp65 of the strain L. mexicana mexicana (NR). These three mAbs were able of recognizing promastigotes of L.m.m. not only for immunofluorescence but also by immunostain. In the immunohistochemistry of biopsies of patients with leishmaniasis, using the three mAbs, it was possible to observe the presence of amastigotes in the infected tissues.

In order to evaluate the possible preventive role of an anaphylactic condition on tumor development, C57BL/6J mice were immunized or hyperimmunized by the intraperitoneal route with egg albumin in alum before the chemical induction of fibrosarcoma. Preimmunization using a protocol which elicits an optimal IgE response produced: (1) a significant reduction of tumor incidence; (2) an increase of survival time, and (3) a decrease of tumor growth rate in animals with higher IgE titers (greater than 640). On the other hand, hyperimmunized mice, which were suppressed in their anti-egg albumin IgE response, showed no changes in tumor incidence and survival time when compared to controls. Our results suggest a suppressive effect on tumor development related to the ability of the animal to mount an IgE response to antigens unrelated to the tumor.