Biomedical subjects

V Ramirez-Amador

Publications and source records attributed to V Ramirez-Amador.

9 recordsLinked to original sources

PubMed2006

(A3) HIV Phenotypes, oral lesions, and management of HIV-related disease.

Workshop participants discussed: the role of HIV subtypes in disease; the treatment of oral candidiasis; the relationship between and among viral load, CD4+ counts, oral candidiasis and oral hairy leukoplakia, pigmentation; and the development of a reliable oral index to predict disease progression. Regarding HIV, the literature revealed that Type I (HIV-I), in particular group M, is involved in the majority (90%) of documented infections, and groups N and O to a lesser extent. Viral envelope diversity led to the subclassification of the virus into nine subtypes, or clades-A-D, F-H, J, and K-each dominating in different geographical areas. HIV-2, currently occurring mostly in West Africa, appears to be less virulent. No evidence could be produced of any direct impact of type, subtype, or clade on oral lesions, and participants believed that further research is not feasible. Oral candidiasis in patients from resource-poor countries should be prevented. When the condition does occur, it should be treated until all clinical symptoms disappear. Oral rinsing with an antimicrobial agent was suggested to prevent recurrence of the condition, to reduce cost, and to prevent the development of antifungal resistance. Lawsone methyl ether, isolated from a plant (Rhinacanthus nasutus leaves) in Thailand, is a cost-effective mouthrinse with potent antifungal activity. Evidence from a carefully designed prospective longitudinal study on a Mexican cohort of HIV/AIDS patients, not receiving anti-retroviral treatment, revealed that the onset of oral candidiasis and oral hairy leukoplakia was heralded by a sustained reduction of CD4+, with an associated sharp increase in viral load. Analysis of the data obtained from a large cohort of HIV/AIDS patients in India could not establish a systemic or local cause of oral melanin pigmentation. A possible explanation was a dysfunctional immune system that increased melanin production. However, longitudinal studies may contribute to a better understanding of this phenomenon. Finally, a development plan was presented that could provide a reliable prediction of disease progression. To be useful in developing countries, the index should be independent of costly blood counts and viral load.

AIDS-Related Opportunistic Infections↗

PubMed2002

Host pathogen interaction and the development of oral lesions.

The aetiologies of oral ulceration, disseminated interstitial lymphocytosis syndrome and oral lymphomas have been reviewed, with emphasis on the role of HIV infection in the primary causation or modification of the presentation of these entities. There is a paucity of evidence to explain why oral ulceration is so severe in HIV infection, and why major ulceration affects the oropharynx. A number of mechanisms have been proposed to account for the development of lymphomas in patients with HIV infection, including a genetic predisposition, decreased immunosurveillance due to HIV infection, alteration of endothelial cell function and dysregulation of cytokine networks. From this review, it was concluded that there is a need for a prospective multicentre study, to elucidate the aetiological mechanisms involved in lymphomas of the oral regions in this patient group. It was concluded that, although there is anecdotal evidence implicating tobacco use in the aetiology of the lesions reviewed, this is insufficient to allow definitive statements to be made and further systematic evaluation is indicated.

AIDS-Related Opportunistic Infections↗

PubMed1999

p53, p21, Rb, and MDM2 proteins in tongue carcinoma from patients < 35 versus > 75 years.

Relatively rare squamous cell carcinomas of the tongue in young patients may be associated with different etiologic factors and pathogenetic mechanisms than carcinomas from the same site in older patients. Alterations in cell cycle proteins likely contribute to the biologic behavior of these neoplasms. The purpose of this investigation was to evaluate cell cycle proteins (p53, p21, Rb, MDM2) in lateral tongue cancers from patients at the two ends of the age spectrum. All available archived lateral tongue carcinomas from patients < 35 years (n = 36, 23 males and 13 females) were sectioned, immunohistochemically stained, and evaluated. Protein expression was scored as percent positive nuclei. An equal number of sequentially accessioned lateral tongue specimens from patients > 75 years (23 males and 13 females) were stained and compared. Positive p53 staining was seen in 18/36 of the < 35-year group versus 24/36 of the > 75-year group (p = 0.149). Increased p21 staining (both percent of positive cells and intensity) was evident in 25/32 of the < 35-year group versus 24/32 of the > 75-year group (p = 1.0). Increased p21 expression was seen in both p53-positive and -negative cases in both age groups. Rb protein was increased in 16/29 of the < 35-year group versus 17/26 of the > 75-year group (p = 0.58). Fourteen cases (4/35 vs 10/36, p = 0.135) showed positive MDM2 staining; MDM2-positive cases were also p53 positive in 4/4 younger and 8/10 older patients. We conclude that p53, p21, Rb, and MDM2 are over-expressed in lateral tongue cancers, and that immunohistochemical profiles are heterogeneous. A p53-independent pathway of p21 induction is supported by the results; p53 suppression may be associated with MDM2 protein expression in a subset of cancers. Significant differences in the expression of p53, p21, Rb, and MDM2 proteins are not evident in lateral tongue carcinomas from patients < 35 years as compared to patients > 75 years.

Adolescent↗

PubMed1999

Oral manifestations as a hallmark of malignant acanthosis nigricans.

We present a case of malignant acanthosis nigricans (AN) that initially manifested in the oral cavity. In the present report, the patient had typical clinical and histological findings of oral and esophageal AN, with subtle skin changes, associated with a gallbladder adenocarcinoma. The importance of the clinical oral examination is emphasized because the recognition of oral lesions led to the diagnosis of AN and to the following detection of the internal malignancy. Since the tumours associated with AN are highly malignant, it is of the utmost importance to recognize the skin and mucous membrane changes in adults.

Acanthosis Nigricans↗

PubMed1998

Oral manifestations of HIV infection by gender and transmission category in Mexico City.

A cross-sectional analysis was conducted in Mexico City from September 1989 to March 1996, to determine the prevalence of HIV-related oral manifestations by gender and route of HIV transmission. The diagnosis of HIV-associated oral lesions was based on preestablished criteria. For the statistical analysis chi-squared and Fisher's exact tests were used where appropriate. Odds ratios were calculated as estimates of the relative risks. Control of confounding factors was performed by logistic regression models. Oral lesions were present in 75% of 436 HIV+ patients. Hairy leukoplakia, erythematous and pseudomembranous candidosis, angular cheilitis and oral ulcers were frequently found. Patients who contracted HIV through blood transfusion were more likely to present erythematous candidosis (P=0.005) than subjects who acquired HIV through sexual transmission. Oral ulcers were seen only in men (P=0.02) and in individuals who contracted HIV through sexual transmission (P=0.02). This study brings valuable data in regard to differences in the type and prevalence of HIV-related oral lesions by gender and the risk categories analysed, particularly blood transfusion.

AIDS-Related Opportunistic Infections↗

PubMed1997

Candidal colonization and oral candidiasis in patients undergoing oral and pharyngeal radiation therapy.

OBJECTIVES: Radiotherapy-induced hyposalivation encourages oral candidal colonization that often leads to oral/pharyngeal candidiasis. The purpose of this study was to quantitate oral candidal colonization, assess signs, symptoms, and response to antifungal management, speciate Candida, and evaluate the influence of smoking and dentures. STUDY DESIGN: Forty-six patients undergoing radiation therapy for oral/pharyngeal squamous cell carcinoma were evaluated clinically and by Candidal cultures before, during, and after irradiation. RESULTS: All patients complained of progressive xerostomia. There was a significant increase in the prevalence of positive candidal cultures (P = < 0.0001): baseline 43%, completion of radiotherapy 62%, and follow-up timepoint 75%. Smoking and denture wearing were not statistically significant risk factors for increased candidal colonization (p = 0.085 and p = 0.420, respectively). Eight patients developed clinical candidiasis. Although five responded clinically to systemic antifungal medication, all follow-up cultures remained positive. Candida albicans was the predominant species at baseline and completion of radiation (85% and 68%, respectively). CONCLUSIONS: When salivary glands are included in the field of radiation, xerostomia occurs, causing progressive increases in oral Candida colonization. Because 17.4% developed clinical candidiasis during radiotherapy and the question of fungal resistance remains speculative, a recommendation for the prophylactic use of antifungal medication is unresolved.

Adult↗

PubMed1996

Oral secondary syphilis in a patient with human immunodeficiency virus infection.

This report describes a case of secondary syphilis in a patient with the human immunodeficiency virus (HIV) in whom the main clinical presentation of the disease was an extensive oral lesion. Few reports in the literature have focused on oral manifestations of syphilis in HIV-infected patients; most of these reports have dealt with a rare manifestation of secondary syphilis, the ulceronodular variety or lues maligna. However, in the case reported here the lesions were painless, smooth, white, oral plaques and papules on an erythematous base with a serpentine and reddish outline corresponding to the description of mucous patches. The differential diagnosis of this lesion may include oral squamous carcinoma, leukoplakia, erythroleukoplakia, candidosis, lichen planus, and granulomatous diseases. This case report emphasizes the importance of considering secondary syphilis in the differential diagnosis of oral lesions in HIV-infected patients, reinforces the importance of follow-up on the patient, and highlights the consideration for routine serologic testing for syphilis in all HIV-infected patients.

AIDS-Related Opportunistic Infections↗

PubMed1996

Altered interface adhesion molecules in oral lichen planus.

OBJECTIVE: To evaluate expression of key epithelial-connective tissue interface adhesion molecules (basal keratinocyte integrins and extracellular matrix receptors) in oral lichen planus (LP). DESIGN: Integrins alpha 3, alpha 6, beta 1, beta 4 and basement membrane proteins laminin 1, laminin 5, collagen IV, and collagen VII were immunohistochemically identified in frozen biopsy specimens (14 oral LP and II matched controls) using a standard avidin-biotin-peroxidase technique. RESULTS: An increased staining intensity of all antigens in LP was shown, as compared to controls. Integrin expression by LP keratinocytes was generally more intense and appeared on more upper level cells. Staining for basement membrane-associated extracellular matrix proteins was also generally more intense, although fragmentation and gaps were typically seen. Reactions for alpha 6, beta 4, laminin 5, and collagen VII stains were particularly intense along the basement membrane. In LP, strands of laminin 5, collagen IV, and collagen VII appeared in the submucosa approximating or duplicating the basement membrane. CONCLUSIONS: The apparent increased expression of the interface-associated adhesion molecules may be reflective of a keratinocyte compensatory response (due to lymphocyte-mediated damage) that would functionally help resist epithelial separation (ulceration). Expression of alpha 3 beta 1 and alpha 6 beta 4 would also assist in epithelial migration associated with wound repair. We interpret the submucosal extensions and deposits of basement membrane proteins as representing remnants of basement membrane, indicating recent remodeling or atrophy of epithelial rete ridges.

Basement Membrane↗

PubMed1995

Cancer of the mobile tongue in Mexico. A retrospective study of 170 patients.

Histological reports of 170 patients with cancer of the mobile tongue between 1977 and 1989 were identified at the Instituto Nacional de Cancerología (INCan), in Mexico City. Demographic, clinical and histological information was retrospectively reviewed. Chi-square, Student's t-test and Wilcoxon rank-sum test were applied for comparisons, and Kaplan-Meier curves, log-rank test and Cox proportional hazards for survival analysis. Of the 161 patients with mobile tongue squamous cell carcinoma (MTSCC), 104 (65%) were males and 57 (35%) were females. The mean age was 60 years old (range 19-91). T1 and T2 lesions comprised 35%, T3 and T4 lesions 65%. There was a statistically significant association between size of the tumour and lymph node involvement (P < 0.0001). The proportion of cases with advanced disease was 80% for males and 57% for females (P = 0.008). The 5-year survival rate was 16% (CI 10.2-22.8%). Cancer of the mobile tongue in Mexico still has a poor prognosis. Efforts should be made to reduce the delay in diagnosis of MTSCC, in order to increase the cure rates and improve the quality of life of the patients.

Adult↗