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Tipificación del virus papiloma humano (VPH) en lesiones preneoplásicas y carcinoma del cuello uterino en mujeres de la IX Región-Chile

: Detection of HPV was 40% in cases without histologicallesion, 88% in low grade lesions, 89% in high grade lesions (HGL) and 93.5% in invasive carcino-ma. Of all HPV positive cases, 89.5% were classified as high risk and only a 4.9% of HPV caseswere of low risk type. Six percent of cases had multiple infections. Distribution of viral genotypesaccording to RFLP was: HPV33 (25.3%), 16 (18.7%), 52 (13.3%), 31 (12%), 35 (6.6%), 18(2.7%).

Estudio comparativo de detección del virus papiloma humano (VPH) en muestras citológicas y biopsias de cuello uterino

Background: The DNA quality for the detection and typification of Human Papilloma Virus (HPV) varies according to the type of sample in which it is studied. This may affect the sensitivity and specificity of the method employed. Aim: To study the yield and specificity of HPV detection and typification in uterine cervical samples obtained by cervical brushing fresh frozen and formalin fixed tissue. Material and methods: Cytological, fresh frozen and fixed tissue samples from 44 patients (nine with low grade lesions and 35 with high grade lesions) were studied. Nested polymerase chain reaction for genes E6/E7 was used to typify HPV groups as low risk or high risk. Results: Of all the cytological samples obtained by brushing 84% of fixed samples and 43% of fresh frozen samples were positive for HPV. The yields were significantly different when comparing brushing with fixed tissue or fresh frozen tissue and fixed tissue with fresh frozen tissue (p <0.05). The frequency of high risk HPV fluctuated from 41% in fresh frozen tissue to 98% in cytological samples. Low risk HPV was detected in 16% of fresh frozen tissue and 68% of cytological samples. A mixed infection was detected in 66%, 41% and 14% of cytological, fresh frozen and fixed tissue samples respectively. Conclusions: Cytological samples obtained by brushing had the highest yield for the detection of cervical infection with HPV (Rev Med Chile 2005; 133: 639-44). (Key Words: Cytological techniques; Cytopathology; Papillomavirus, human)

Detección y tipificación de virus papiloma humano en lesiones preneoplásicas del cuello uterino mediante PCR-RFLP

. Los genotiposde HPV que infectan el tracto genital femenino, sehan clasificado en 2 grupos: de bajo riesgo (BR) y dealto riesgo (AR) segun el potencial oncogenico parael desarrollo de lesiones preneoplasicas o neoplasi-cas. Los genotipos de bajo riesgo (BR) mas frecuen-tes son los HPV: 6, 11, 43 y 44 y se asocian concondilomas o neoplasias cervicales intraepitelialesde bajo grado (LBG). En el grupo de alto riesgo (AR)15 tipos de HPV han sido identificados (HPV 16, 18,31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73 y 82),detectados principalmente en neoplasia cervicalintraepitelial de alto grado (LAG) y carcinomas

Estudio de patrones de metilación génica en tumores del tubo digestivo

Background: The loss of tumor suppresor gene function damages the defensive mechanisms that protect the indemnity of genetic material. Promoter gene methylation is one of the inactivation mechanisms of suppressor genes. Aim: To study the methylation pattern of a group of genes in biopsy samples of gastrointestinal tumors. Material and methods: Forty eight gastric, 25 gallbladder, 24 colon and 6 pancreas cancer biopsy samples were randomly selected. The methylation pattern of CDH1, FHIT, CDKN2A, APC and MLH1 genes, was studied using a specific polymerase chain reaction test for methylation. Demographic, morphological and follow up variables of patients bearing the tumors were also analyzed. Results: The general methylation frequency of CDH1, FHIT, CDKN2A, APC and MLH1 genes was 64.1, 56, 39.8, 18.1 and 34% respectively. In gastric cancer samples there was a correlation between APC gene methylation and well differentiated tumors; between CDH1 methylation and Lauren diffuse type and the presence of three or more metastasic lymph nodes; between FHIT, CDKN2A and CDH1 gene methylation and male gender. In iess differentiated gallbladder tumors, the frequency of CDH1 methylation was higher. There was a tendency towards a lower survival in colon and gastric cancer when MLH1 (p =0.07) y CDKN2A (p= 0.06) were methylated, respectively. Conclusions: An abnormal methylation pattern was associated with morphological features in gastric and gallbladder cancer and with a tendency towards a lower survival in colon and gastric cancer

Expresión inmunohistoquímica del complejo E-caderina-catenina en cáncer gástrico: Relación con variables clínico-morfológicas y sobrevida de pacientes

l cancer gastrico es la segunda neoplasia masfrecuente a nivel mundial, despues del cancerpulmonar. Las mayores incidencias se registran enChina, Japon, Europa del Este y Sudamerica. Estaneoplasia ocupa el segundo lugar a nivel mundialen mortalidad, con mejor sobrevida solo en Japon,Australia y Nueva Zelanda, debido principalmenteal diagnostico precoz

Mutación del gen K-ras en el cáncer de la vesícula biliar

BACKGROUND Different K-ras mutation frequencies in gallbladder cancer have been reported. AIM To study the frequency of K-ras gene mutations in advanced gallbladder carcinoma not associated to anomalous junction of pancreatic-biliary duct (AJPBD). MATERIAL AND METHODS 33 formalin fixed paraffin embedded samples of gallbladder carcinoma (30 women, age range 32-86 years) were selected. Pancreatic cancer tissue with K-ras mutations was used as control. DNA was extracted from the histological section by mean of microdissection and K-ras mutations in codon 12 were detected by polymerase chain reaction and restriction fragment length polymorphism (RFLP), using previously reported technique. RESULTS Most cases were poorly differentiated adenocarcinomas. K-ras mutation was detected in 10 cases (30%) samples. No differences in K-ras mutation frequency between subserous and serous tumors were detected and no relation between histological features and the mutation was observed. CONCLUSIONS K-ras mutation in codon 12 is present in 30% in our advanced gallbladder carcinomas. The study of K-ras mutation in preneoplastic lesions and early carcinonmas will be important to determine the role of this gene in the gallbladder carcinogenesis in Chile.

Frecuencia de los genes de fusión TEL/AML1 y BCR/ABL en pacientes pediátricos con leucemia linfoblástica aguda

TEL/AML 1 and BCR/ABL fusion gene transcriptswere detected in 13 (23%) and 2 (4%) children, respectively. No differences in survival wereobserved between children with positive or negative transcripts for TEL/AML1 fusion gene. However,those positive for BCR/ABL fusion gene, had a significantly lower survival.

Mutación del gen K-ras en tumores pancreático-biliares

Background: The ras gene family (H-ras, N-ras and K-ras) are oncogenes that mutate frequently in human cancer, specially in tumors of the biliary tract and pancreas. Aim: To determine the frequency of K-ras gene codon 12 mutation in pancreatic and biliary tumors. Material and Methods: Samples of 35 gallbladder, 15 ampulla of Vater, 10 biliary tract and 9 pancreatic tumors, were analyzed. The tumor tissue was microdissected from paraffin embedded biopsies. The mutation was detected by a combination of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Results: Overall, 46% of samples had K-ras gene mutations. Mutation frequency was 80, 56, 50 and 29% for ampulla of Vater, pancreatic, biliary tract and gallbladder tumors, respectively. When compared with the rest, gallbladder tumors had a significantly lower frequency of the mutation. Median survival for biliary tract tumors was 6 months, compared with 65 months for gallbladder tumors (p <0.05). Conclusions: Gallbladder carcinoma had the lower frequency of K-ras mutation, when compared with pancreatic, biliary tract and ampulla of Vater tumors (Rev Med Chile 2005; 133: 1434-40). (Key Words: Biliary tract neoplasms; Gallbladder neoplasms; Genes, ras; Pancreatic neoplasms)

Carcinoma subseroso de la vesícula biliar: expresión del complejo caderina-catenina

Background: Subserous gallbladder carcinoma is difficult to diagnose and treat. There are no tissue markers with prognostic value in this type of tumor. Aim: To study the immunohistochemical expression of E-cadherin alpha and beta catenin in subserous gallbladder carcinoma. Patients and methods: One hundred seventeen subjects (103 women and 14 men aged 62 and 69 years as a mean, respectively), were studied. Thirty five gallbladder samples without evidence of cancer were used as controls. Expression of markers was studied with standard immunohistochemical techniques for formalin fixed and paraffin embedded tissue. Results: Ninety seven percent of tumors were adenocarcinoma. A lower or absent expression of E-cadherin, alpha catenin and beta catenin was observed in 26, 33 and 29% of tumors, respectively. Actuarial five years survival was 37%. No association between macroscopic features of the tumor and survival was observed. Well differentiated tumors had a 73% survival, whereas less differentiated tumors had a 30% survival. Tumors with a normal expression of the markers had a slightly better survival, although not significant (p=0.06). Conclusions: Approximately 30% of subserous gallbladder carcinoma have an abnormal expression of E-cadherin, alpha catenin and beta catenin. This abnormal expression has no relationship with prognosis and is probably secondary to the aberrant genic expression of the tumor (Rev Med Chile 2002; 130: 1349-57)

Detección y tipificación de virus papiloma humano en adenocarcinoma de cuello uterino mediante reverse line blot, Región de La Araucanía, Chile

Seventyone percent of biopsies were positive for HPV. The most common genotypes found were HPV 16(61%), followed by HPV 18 (19.5%). Eighty seven percent of biopsies had a single HPV infection.Three patients had a multiple HPV infection. All of the latter were infected by HPV 16, associatedwith other three viral genotypes (45, 52 and 66). No low-risk HPV genotypes were found.