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Biomedical subjects

I Serra

Publications and source records attributed to I Serra.

At least 19 recordsLinked to original sources
PubMed1998

Mutations of p53 in gallbladder carcinomas in high-incidence areas of Japan and Chile.

Gallbladder adenocarcinomas from patients in two high-prevalence areas, Niigata (Japan) and Santiago (Chile), were analyzed for acquired mutations in exons 5-8 of the p53 tumor suppressor gene, and the characteristics of p53 alterations in the two groups were compared. Of 42 tumors, 22 (52.4%) harbored 25 alterations identified by PCR amplification and direct sequencing (13 of 22 tumors from Niigata and 12 of 20 tumors from Santiago). All alterations were single base pair substitutions, 20 (80%) leading to an amino acid substitution or a chain-termination signal, and 5 (20%) were silent. Immunohistochemically, 55 of 84 cases (65.5%) showed overexpression of p53 protein, with no significant difference in frequency between the two areas. Missense mutations correlated highly with overexpression of the p53 protein (93.4%). Mutations of p53 occurred in all four exons examined, most commonly in exon 5, but in no particular "hot spot." In base-change spectra, all 12 mutations from Santiago showed transitions, with 4 arising at the CpG dinucleotide (33.3%). In contrast, no such transition was found at CpG sites in Niigata, and 4 of 13 mutations (30.8%) were transversions. The data indicated that p53 mutations are highly important in carcinogenesis in the gallbladder. In addition, the difference in p53 mutational spectra in Niigata and Santiago indicate a likely regional difference in mutagenesis.

Adult↗
PubMed1998

[Audit of deaths due to cervical cancer in a health service of Santiago. A preliminary analysis].

BACKGROUND: Despite the epidemiological importance and the surveillance programs to detect cervix uterine cancer in Chile, its mortality continues to be high. AIM: To perform an audit of all deaths due to cervix uterine cancer, that occurred in a health service of Santiago during 1995. MATERIAL AND METHODS: The clinical records and pathological studies of 46 women, whose death certificates indicated cervix uterine cancer as the cause of death, were audited. RESULTS: In six women, the audit revealed that the cause of death was not a cervix uterine cancer, and they were discarded from further analyses. The higher mortality rate (36/100,000) occurred in women over 64 years old, those living in the poorest community and with less Papanicolaou vaginal smears coverage (La Pintana). The evolution prior to diagnosis was registered in only four women and was of less than one year. Most women consulted in advanced stages of the disease and only 48% were subjected to some sort of treatment (surgery, radiotherapy or chemotherapy). Mean survival was 3 years and mean age at death was 55.5 years old. There was a great lack of clinical and epidemiological information. In only 13 women information about previous Pap smears was registered. CONCLUSIONS: Audit of deaths should be an important component of preventive programs for cervix uterine cancer, and the coverage of Pap smears should be improved.

Adult↗
PubMed1997

Genetics of retinoblastoma: a study.

We have analyzed 43 families with either familial retinoblastoma (RB) (four kindreds), bilateral sporadic RB (10 individuals), or unilateral sporadic RB (29 individuals). Genetic studies focused on karyotype analysis, loss of heterozygosity of intragenic polymorphisms, and search for point mutations. We have been able to identify the genetic defect underlying the disease in eight cases. Deletions have been found in three patients with sporadic RB, two bilateral in one of which karyotyping had previously detected an interstitial deletion of chromosome 13 affecting (q13-q31) and one unilateral. Five different point mutations were responsible for three cases of bilateral sporadic RB, one case of bilateral sporadic RB, and one case of bilateral familial RB. The low frequency of constitutional mutations found in our study has led us to review and evaluate the possibilities and limitations of the present genetic analyses on RB and to access the different factors influencing the detection of mutations causing the disease, because genetic counseling is mainly based on mutation identification.

Chromosomes, Human, Pair 13↗
PubMed1997

[Risk factors for gallbladder cancer in Chilean females].

A case-control study of gallbladder cancer was conducted with 90 Chilean cases registered at one hospital in Santiago city, Chile from January, 1992 to August, 1994. Controls were selected among outpatients of the hospital who received abdominal echography. Each case was assigned 2 age- and sex-matched controls; either with or without gallstone(s). Study subjects were all directly interviewed by well-trained medical students. The present study focused on 74 female pairs and the following findings were obtained: 1) Odds Ratio(OR)s were significantly high for education years less than or equal to 6, body mass index greater than or equal to 24.0, constipation, and consumption of egg, fried meals, green and red chili. Chili pepper consumption of both types in cases showed significantly elevated risks with higher frequency. 2) While high ORs were observed, biliary symptoms such as dyspepsia and past history of cholelithiasis were strongly involved with present gallstone(s) and may not be independent factors for gallbladder cancer. 3) Significantly low ORs were seen for past history of intestinal parasitosis and surgical operation, hormone therapy, all industrial workers and workers in clothes & textile industry. However results may be influenced by more years of education or recall bias. 4) When a conditional logistic model was applied and controls with gallstone(s) were taken as reference, those with the habit of constipation showed a significantly high risk of 2.10 (95% CI: 1.01-4.38), and the consumers of red chili with a frequency > or = 1 time/day had elevated risks of 2.16 (1.27-3.66) vs those < 1 time/day and 4.66 (1.63-13.40) vs non-consumers, respectively. From the above results, the occurrence of gallbladder cancer in Chilean females may be related to constipation and chili pepper consumption, based on the presence of gallstone(s). Further investigations are needed to elucidate whether these are actual risk factors or whether only a false association was detected.

Case-Control Studies↗
PubMed1995

[Current situation of human hydatidosis in Chile. 2 proposals for correcting its undernotification].

Hydatidosis continues to be a prevalent disease in Chile. Since 1985 and until 1990, the number of notified cases decreased abruptly, probably due to sub-notification. Lethality, not calculated officially, increased since 1985 in a roughly similar proportion to the decrease in communicated incidence. This fact, along with an increase in hospital discharges due to the disease in the country, confirms the hypothesis that sub-notification is true. Two estimation systems for the magnitude of sub-notification are proposed, one based in the expected lethality and the other in the corrected hospital discharges, taking into account the phenomenon of re-admission. Both systems, although differing, disclose much higher incidence of hydatidosis than the communicated figure. A critical analysis of both systems is done.

Adolescent↗
PubMed1995

[Epidemiological profile of liver cirrhosis in Chile 1970-1992].

BACKGROUND: Liver cirrhosis is an important public health problem in Chile. AIM: To review the main epidemiological features of liver cirrhosis in Chile in the last 22 years. METHODS: Review of yearbooks of mortality and causes of death of the Ministry of Health and Instituto Nacional de Estadísticas, review of hospital discharges and review of international statistics published by the World Health Organization. RESULTS: The mortality rate of liver cirrhosis in 1992 was 17.9/100,000 inhabitants and represented 3.3% of all deaths. The risk of cirrhosis is higher among men and in people over 64 years of age. In the last decade, death rates of young adults (15-44 years old) and children decreased dramatically. Hospital discharge rates for cirrhosis have decreased from 46.7 in 1970 to 40.4 in 1992. The men/women ratio in 1991 was 2.1/1 for hospital discharges and 2.8/1 for mortality. Mortality was higher in large urban areas (Santiago, Valparaíso and Concepción). A correlation of +0.17 was found between death rates for cirrhosis and wine production per capita. CONCLUSIONS: Cirrhosis continues to be a highly prevalent disease in Chile.

Adolescent↗
PubMed1993

[Epidemiological evolution of human hydatidosis in Chile, 1965-1988. Impact of livestock programs in the XI and XII regions].

The aim of this work was to analyze the possible impact of livestock echinococcosis control programs in the XI and XII regions of Chile, on the incidence of human echinococcosis. National morbidity was stable until 1984, with an abrupt and important decrease afterwards. Mortality showed a slight tendency to decrease during this period. There was an increase in lethality, that was equivalent and contemporary to the communicated decrease in morbidity after 1985. It is concluded that the national and regional decrease in the communicated cases of echinococcosis is due to a decrease in the notification of the disease. This problem was originated in administrative decisions of the Ministry of Health in 1985, whose effects persist. An instrument to correct retrospectively this low notification is proposed.

Chile↗
PubMed1992

[Proposal of a new table of weight increase for undernourished children under the age of 6].

All children (n = 447) under 6 years of age attending an outpatient facility during 1988 were evaluated for weight increase according to the current table. Recovery of undernutrition was estimated at a mean of 45%. A new table, based on the fact that undernourished children have a greater potential for weight increase was developed and applied prospectively during 1989 (n = 307). Recovery from undernutrition was 60%, especially high in preschool children who improved from 35% en 1988 to 56% in 1989 (n < or = 0.01). This was attributed to an individualized educational program as an additional measure to the National complementary feeding program. Better controls for children who failed to attend may help improve recovery from undernutrition which is relatively stagnant since 1982.

Child↗
PubMed1990

Biliary-tract cancer in Chile.

This epidemiological study in Chile shows a marked increase in biliary-tract cancer based on mortality data, from an age-adjusted rate (1970 world population) of 5.1 per 100,000 in 1970 to 12.0 per 100,000 in 1988. There is an increased risk of this cancer in all age groups but especially in young adults (15-44 years). The female ratio of 3:1 persists. The increase in biliary-tract cancer in 1970-1985 was particularly important for young women but occurred in all female age groups whereas in men it was mostly in the elderly (65 years and more) and less in the middle-aged (45-64 years); no changes were observed in young men. Regional differences have begun to be appreciated. One of the factors which may account for this impressive and unexpected increase is the remarkable decrease in cholecystectomy rates. Less than 20% of the 154% increase in biliary-tract cancer mortality in the period 1970-1985 could be attributed to population aging. Improvements in diagnostic methods did not appear to be an important contributing factor. Other factors that could affect this increase in the incidence to epidemic levels include: an increase in the prevalence of cholelithiasis, an increase in the number of typhoid carriers and possible environmental carcinogens.

Adolescent↗
PubMed1990

[Measles in Chile].

Outbreaks of measles have occurred in Chile in 1979, 1985 and 1988. A greater proportion of cases affected babies under 1 year of age and patients above age 14. However, the increase in mortality was small. Low quality of the vaccine and deficiencies in the vaccination programs may be implicated in these epidemics. Use of high quality vaccines, vaccination programs based on serological information and better epidemiologic surveillance are proposed to prevent new outbreaks of the disease.

Adolescent↗
PubMed1988

Cytodifferentiation of mouse visceral endoderm: study with a teratocarcinoma antiserum.

In this work we separated homogeneous embryoid bodies (EB); this population is composed of only endodermal vesicles of a visceral type. These EB were used to immunize rabbits. After absorption, the antisera were analyzed immunohistochemically in sections of 7.5- and 9-day-old mouse embryos, which showed a selective reaction to visceral endoderm. The cytodifferentiation of the visceral endoderm was studied.

Animals↗