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Biomedical subjects

R Tassara

Publications and source records attributed to R Tassara.

13 recordsLinked to original sources
PubMed2002

[Merkel cell carcinoma of the skin in a patient with myasthenia gravis].

Merkel cell carcinoma is a rare, aggressive neuroendocrine tumor of the skin commonly seen in the elderly on the head, neck and extremities, with a predisposition for local regional and distant spreading. A case of Merkel cell carcinoma occurred in a woman treated with immunosuppressive therapy for myasthenia gravis, is described and the possibility of a link between the immunosuppressive and/or oncogenic therapy and this tumor is suggested.

Aged↗
PubMed2001

[Serological certification of the interruption of the vectorial transmission of Chagas disease in Chile].

BACKGROUND: In 1999 an International Commission of Experts evaluated the sanitary interventions that started in 1980 to eliminate Triatoma infestans, the biological vector of Chagas disease, to certify if the conditions needed to interrupt the transmission, were achieved. AIM: To report the data used by the International certification commission to certify the interruption of vectorial transmission of Chagas disease in Chile. MATERIAL AND METHODS: A comparative evaluation of the prevalence of Trypanosoma cruzi antibodies in children surveyed between 1994 and 1995 and between 1995 and 1999. RESULTS: In the first period, 5,948 children were surveyed and in the second, 5,069 children were studied. Twenty children (0.4%) were positive for Trypanosoma cruzi antibodies in the second survey. These figures were significantly lower than the 1.1% prevalence detected between 1994 and 1995. In only three of the 20 cases, the transmission through vectors was confirmed, which represents a 99.4% reduction of this way of transmission. CONCLUSIONS: Based on these findings, the Commission certified that Chile is the second country in Latin America to interrupt the vector transmission of Chagas disease. The successful public health program for Chagas disease will have a positive impact improving the quality of life of rural populations, that are most exposed to the disease.

Animals↗
PubMed1997

[Clinical and epidemiological study of blood donors seropositive for Trypanosoma cruzi].

BACKGROUND: The prevalence of positive antibodies for Chagas disease in a blood bank of a public hospital in Santiago is 1.2%. These positive individuals should be informed about their condition and further studied. AIM: To perform a serological confirmation, an epidemiological and clinical assessment of blood donors seropositive for Chagas disease in a blood bank of Santiago. SUBJECTS AND METHODS: One hundred eleven seropositive donors, detected between 1994 and 1996, were studied. Serological reactions were confirmed with ELISA and indirect immunofluorescence reactions. Those confirmed as positive were subjected to a clinical-epidemiological questionnaire, physical examination, EKG and barium enema or swallow according to symptoms. RESULTS: Seventy individuals were confirmed as positive for Chagas disease. Most of them lived at least once in an endemic zone for Chagas disease or in a sun-dried clay brick house. Forty-percent of individuals knew reduviid bugs and 14% had been bitten by these insects. Twenty six percent of these subjects had an abnormal EKG (61% with bradycardia). No digestive diseases attributable to Chagas disease were detected. CONCLUSIONS: The high prevalence of problems attributable to Chagas disease among seropositive blood donors underscores the need of an epidemiological follow up of these individuals.

Adult↗
PubMed1992

[Pneumocystis carinii infection. Various aspects on its clinical and laboratory diagnosis].

P carinii is an opportunistic pathogenic agent able to produce severe infection that must be diagnosed promptly. We analyzed 138 samples from 100 patients suspected of having infection by P carinii. The ortho-toluidine blue and the methenamine stains were used to analyze the samples. Infection was demonstrated in 18 patients, 13 adults and 5 children. Underlying disease was AIDS in 7 and other immunosuppressive disorders in the rest. No immunocompetent patient was infected with P carinii. Proper sample collection is important for diagnosis. When bronchoalveolar lavage is not possible, pharyngo-tracheal aspirate in children and sputum sampling after assisted coughing in adults are recommended. At least 2 staining methods and proper controls are advisable.

Adult↗
PubMed1991

[Application of a system of serological surveillance of Chagas disease in a region of high chagasic endemia. I. Prevalence of Trypanosoma cruzi infection in Salamanca].

A serologic study for prevalence of Chagas infection was performed in Salamanca, Northern Chile. Indirect immunofluorescence and indirect hemagglutination reactions were used in samples from 1529 females and 698 males representing 10% of the population. A total of 499 positive results were obtained. The incidence of infection increases at a mean rate of 1% per year up to age 30, declining slowly in older groups to reach a maximum of 39.7% for the population. These data will be used to implement appropriate serologic surveillance programs and sanitary control measures in this and other populations.

Adolescent↗
PubMed1989

[Diagnosis of cryptosporidiosis: a comparative study on Ziehl-Neelsen and safranine stain methods].

Infection by cryptosporidium causes acute or chronic diarrhea in immunocompetent or immunosuppressed patients respectively. We compared the Ziehl-Nielsen and the safranine stains in 604 stool samples from children with acute diarrhea. Sensitivity for safranine (96%) and for Ziehl-Nielsen (88%) was not significantly different. Given the simplicity and low cost of the safranine stain, this is proposed as a routine method for the investigation of infection by cryptosporidium.

Child↗