Differential percentage of serum prostate-specific antigen subforms suggests a new way to improve prostate cancer diagnosis.

BACKGROUND: Prostate-specific antigen (PSA) is the tumor marker currently used for prostate cancer (PCa) screening and diagnosis. However, its use is controversial as serum PSA levels are also increased in other non-malignant prostatic diseases such as benign prostatic hyperplasia (BPH). PSA sialic acid content is altered in tumor situation and modifies PSA's isoelectric point (pI). Our goal has been to evaluate serum PSA subforms from PCa and BPH patients by two-dimensional electrophoresis (2-DE) and to investigate whether they could be used to improve PCa diagnosis. METHODS: PSA from 20 PCa and 20 BPH patients' sera was subjected to a four-step method to obtain serum PSA 2-DE subforms from free PSA (fPSA) plus PSA released from the complex with alpha-1-antichymotrypsin. Relative percentages of PSA spots were quantified and subjected to statistical analysis. RESULTS: Five PSA subforms (F1, F2, F3, F4, and F5) of different pI were obtained. Relative percentages of F3 (%F3) and F4 (%F4) were different between PCa and BPH groups. %F3 decreased in cancers and this decrease correlated with the cancer stage, while F4 behaved oppositely. These observations were also found when only focusing on the patients within the low total PSA (tPSA) range 2-20 ng/ml. CONCLUSIONS: %F3 showed a tendency of higher sensitivity and specificity than the currently used tPSA and %fPSA tests. Therefore, %F3 measurement should be investigated in a larger cohort of patients to study whether it could be introduced to improve PCa diagnosis.

Different glycan structures in prostate-specific antigen from prostate cancer sera in relation to seminal plasma PSA.

Prostate-specific antigen (PSA), the tumor marker currently used for prostate cancer (PCa), is not specific enough to distinguish between PCa and benign prostate hyperplasia (BPH). Glycan processing is normally perturbed in tumors, therefore we investigated whether changes in glycosylation of PSA could be useful diagnostic indicators. Previously we determined that the glycosylation of PSA secreted by the tumor prostate cell line LNCaP differs significantly from that of PSA from seminal plasma (normal control). We therefore undertook a detailed glycan analysis of PSA derived from sera from PCa patients and, importantly, established that the glycosylation of the PCa serum PSA was significantly different from the PSA from the LNCaP cell line. In comparison with seminal plasma PSA, the fucose content of PSA from the PCa patient serum was significantly lower and there was a decrease in alpha2,3-linked sialic acid. Differences in the glycosylation of PSA derived from PCa patients' sera, seminal plasma, and LNCaP cells were further established by lectin detection, glycosylation immunosorbent assay, and two-dimensional electrophoresis. We also investigated whether the impact of glycosylation changes initiated by the tumor was reflected in the serum glycome. By comparing the glycans released from the total glycoproteins in PCa patient serum with those of normal serum we found an increase in the proportion of sialyl-Lewis x structures. Further analysis of the glycosylation of PSA from PCa and BPH sera will be required in order to determine the utility of these glycan differences to discriminate specifically between benign and malignant prostate states.

[Hierarchical structure of authors collaboration. An analysis of papers on imaging diagnosis published by hospital radiology departments in Comunidad Valenciana (1994-2001)]. / Estructura jerárquica de la colaboración entre autores. Análisis de los artículos sobre diagnóstico por la imagen publicados por los servicios hospitalarios de Radiología de la Comunidad Valenciana (1994-2001).

OBJECTIVE: Analyze the different contribution of hierarchical categories in the papers published by radiologists of hospitals belonging to Comunidad Valenciana along the period 1994-2001, as well as their distribution in the different journals. MATERIAL AND METHODS: For the recovery of the papers sample we have designed specific search profiles for EMI and Medline databases. Hierarchical category of the authors was identified through personal interviews. RESULTS: We have analyzed 417 works, with 1,321 authors distributed in the following form: chief of service, 8.8%; chief of section, 12.4%; assistant physician, 50.7%, and resident, 28%. Hierarchical groupings with participation of residents were more consistent for publishing papers along all the study period (1994-2001). Higher percentage of papers (21%) corresponded to <> grouping. Radiología was the most productive journal (42% papers). All results were statistically significant (p < 0.0001). CONCLUSION: Radiodiagnosis residents of Comunidad Valenciana hospitals showed an active participation in research papers published along the period 1994-2001, in collaboration with the rest of the hierarchical categories, basically with the assistant physician. Assistant physicians contributed most of papers. Chief of section and chief of department contributed fifth of papers.

[Analysis of information sources in the journal, Atencion Primaria]. / Análisis del consumo de información en la revista Atención Primaria.

OBJECTIVES: To contribute to improving the understanding of the information bases of Spanish scientific production in the primary care field; to aid international contacts and the diffusion of information among doctors in our country. DESIGN: A bibliometric analysis of the bibliographic references of the studies published in the journal Atención Primaria during 1991. A data base, managed by dBASE IV, was created. SETTING: The Unit of Documental Analysis and Bibliometry of the Institute of Documental and Historical Studies in Science (University of Valencia-CSIC). MATERIAL: 2,615 bibliographic references in 205 studies contained in volume 8 of Atención Primaria. MAIN RESULTS: References from journal articles (68%) and books (26%) predominated. There were a large number of references from Spanish publications (45%) as against Northamerican (27%) and British (15%). There were few references from other European countries or Latin America. Information was quickly out of date (4 year semiperiod; Price index 50%). High proportion of self-quotations from the journal. CONCLUSIONS: The major role of the journal Atención Primaria in communicating information in the primary care field was underlined. The small amount of information from Latin America and E.U. countries (except Great Britain) highlights the isolation of Spain from these countries, which can be explained by the limits of the primary care field itself. There was also little use of information to which access was more difficult for primary care doctors, such as doctoral theses, congress papers or reports. Moreover this is a field with a high percentage of recent literature and rapidly out-of-date information.

[10 years of literature on AIDS (1983-1992): bibliometric analysis]. / Diez años de literatura sobre el sida (1983-1992): análisis bibliométrico.

BACKGROUND: Reasons for the quantitative study of the Spanish publications on AIDS are both the huge volume attained by the printed material on the subject since the first case was described in 1981 by the Center for Disease Control, and the high incidence of the cases reported on this disease. METHODOLOGY: Searches have been performed on the subject through the database of the Indice Médico Español (IME), the Indice Español de Ciencia y Technología (ICYT), the ISBN and Bibliografía Española in order to retrieve all possible Spanish journal papers' and books. The references were distributed using criteria of documentary tipology, publication date, institutions involved, autonomous communities, and, finally, after its relation with the confirmed cases of AIDS. RESULTS: A total 2,013 items have been retrieved, 1,821 journal papers' and 192 books. More than 50% of the papers are published only by five journals, being 139 the total number of journals able to carry pertinent information. The most productive journals were Medicina Clínica and Enfermedades Infecciosas y Microbiología Clínica. CONCLUSIONS: The results confirm exponential growth of the publications from 1983, the first year when a paper was published on AIDS in Spain. The grow is similar to the tend observed in other countries. Parallelism has been detected between growth in the number of publications and in the number of journals publishing on the subject, the growth in the number of journals publishing on the subject, the growth in the number of institutions which collaborate and the growing tend of reported cases in Spain. The results of the bibliometric study, showing an epidemiological growth out of comparison in the history of the scientific literature, could be useful both to information scientists, and to the research inside this scientific field.

[Analysis of utilization of information in the journal Medicina Clinica]. / Análisis del consumo de información en la revista Medicina Clínica.

BACKGROUND: Scientific communication knowledge is specifically based in the analysis of the bibliographic references inside the publications. Pattern and laws determining the information consumption in the items of the journal Medicina Clinica are investigated in the present study as its own aim. METHODS: An analysis was performed on the 13,286 references downloaded from 618 papers published by the journal in 1990. With dBASE IV was generated a database for the management of the information; data was distributed in several tables through criteria of age, documentary types, countries, journals and Bradford zones. RESULTS: The analysed references belong to 1,241 different journals, 110 from Spain. Being two thirds of the total sum, the publications from United States and United Kingdom have received more citations than those from Spain. The publications from european countries, like France, Germany and Italy, are scarcely present. Bradford core is constituted by the journals Medicina Clinica and The Lancet. CONCLUSIONS: The analysis of the bibliographic references available from the articles in this journal is able to produce knowledge on the information consumption by the practitioners; its usefulness as a complementary utility to the Indice de Citas e Indicadores Bibliométricos de Revistas Españolas de Medicina Interna y sus especialidades 1990 must be considered.