Drug-resistance mutations in antiretroviral-naïve patients with established HIV-1 infection in Mexico.

OBJECTIVES: To describe the prevalence of baseline drug-resistance mutations, resistance to antiretroviral drugs, and the subsequent virological response to therapy in treatment-naïve patients from Mexico with established HIV-1 infection. METHODS: Resistance testing was performed on plasma samples from antiretroviral-naïve patients. Data on mutations associated with antiretroviral drug resistance were obtained using Stanford software (http://hivdb.stanford.edu). RESULTS: Ninety-six treatment-naïve individuals were enrolled in the study during 2002-2003. Of these, 83 patients (86%) had at least one resistance mutation and 15 (16%) had drug resistance. At baseline, the mean plasma viral load was 299 834 HIV-1 RNA copies/mL, and at follow-up it was 37 620 copies/mL (P<0.0001). Primary mutations in the reverse transcriptase region were observed in 15% of patients. For nucleoside inhibitors, mutations T215Y/C and F77L (3%) and D67N/S, T69N and M184V (2%), were detected. For nonnucleoside inhibitors, mutations K103N/R (6%), Y181C (3%) and G190A (2%) were detected. Overall, 6% of patients showed resistance to delavirdine and nevirapine, 4% to efavirenz, and 2% to lamivudine and nelfinavir. Twelve patients showed no response to treatment and three of these patients had antiretroviral drug resistance. CONCLUSIONS: The prevalence of baseline drug-resistance mutations found in this study was similar to that found in previous reports for newly HIV-infected individuals, although access to and management of antiretrovirals in Mexico are different.

[Epidemiological characteristics of liver cirrhosis at the Hospital Civil of Guadalajara]. / Características epidemiológicas de la cirrosis hepática en el Hospital Civil de Guadalajara.

OBJECTIVE: A prospective study of the demographic and epidemiologic characteristics of patients with liver cirrhosis at the Hospital Civil de Guadalajara within a period of one year. MATERIAL AND METHODS: A total of 157 patients (48 women, and 109 men) from the Departments of Internal Medicine, Gastroenterology and Liver Clinic were studied. Diagnosis of liver cirrhosis had been previously established based on clinical, biochemical or histopathological information. Additionally, a questionnaire specialized on liver diseases was applied to all patients. RESULTS: Alcoholism was the main cause for cirrhosis (38% in women and 95% in men) followed by viral etiology. The alcoholic beverages consumed with greater frequency were tequila and 96 degrees G.L. alcohol. Women were in the Child-Pugh's "B" class while men were in class "C". Complications were mostly gastrointestinal bleeding, ascites and hepatic encephalopathy. Differences between sexes were observed for various characteristics. CONCLUSIONS: Alcoholism was by far the most frequent cause of liver cirrhosis. The second cause, in women, was of viral origin (16.7%). A national committee of vigilance of liver diseases is proposed to generate more complete and detailed information on the epidemiology of liver cirrhosis.

[Molecular genetics of colorectal cancer and carcinogenesis]. / Genética molecular del cáncer colorectal y carcinogénesis.

Genetic and environmental aspects play an important role in the development of colorectal cancer. However, the common molecular alteration in both hereditary and sporadic colon cancer is localized in the APC gene. the APC gene maps in the long arm of chromosome 5 and was discovered in patients with familial adenomatous polyposis (FAP). The search for the APC gene led to the identification of restriction fragment length polymorphisms (RFLPs) in FAP patients. Using these RFLPs in relatives of FAP patients it is possible to make the presymptomatic and prenatal diagnosis. The FAP syndrome is an interesting model of carcinogenesis in vivo. Thus the different stages involved in the FAP syndrome which include hyperproliferative epithelium, adenoma, adenocarcinoma and metastases, have allowed the analysis of molecular alterations in oncogenes and tumor suppressor genes. The APC gene alteration if not inherited, occurs as the earliest molecular alteration in the development of colorectal cancer whereas structural alterations of the genes myc, ras, p53, MCC and DCC are considered to be late events. All these investigations have lead to 1) a better understanding of the ethiology of cancer and 2) early diagnosis of colorectal cancer in both the hereditary and sporadic forms of the disease.

[Acrodysostosis]. / Acrodisostósis.

Two unrelated males of 16 and 8 years of age with acrodysostosis were studied. They showed short stature, broad and hypoplastic nose and severe acromelic shortness. X-ray studies revealed bilateral brachymetacarpaly, brachymetatarsalia and brachyphalangia with hyperplasia of the first ray in hands and feet. Psychometric studies revealed an IQ of 85, the highest observed in the 22 cases so far reported. The variable expressivity of the syndrome is discussed on this basis. The hypothesis of an autosomal dominant "de novo" mutation as the cause of the entity is supported by the finding of increased paternal age.