[Current aspects of prostate cancer screening]. / Aspectos actuales sobre el cribado en el cáncer de próstata.

Screening programs for prostate cancer based on the determination of serum prostate specific antigen has led to overdiagnosis, and consequently overtreatment. A percentage of men diagnosed with prostate cancer have a tumour that will not progress, or do so slowly (overdiagnosis or pseudo-disease). This overdiagnosis rate ranges from 17-50%. Mass screening is defined as the systematic examination of asymptomatic men. Early detection or opportunistic screening involves the pursuit of individual cases being initiated by the doctor or the patient. In the case of a patient who requests a prostate specific antigen from their general practitioner, a number of issues on overdiagnosis, over-treatment and possible damage from the biopsy, should be explained to him. With data from randomised studies on prostate specific antigen and prostate cancer screening, population screening is not recommended by any urological society.

2E3, a new marker that selectively identifies porcine CD4+ naive T cells.

We describe a novel antigen recognized by mAb 2E3 selectively expressed in the periphery by a subset of porcine CD4+ T cells. Both, CD4+CD8alpha- and CD4+CD8alphalow T cell subpopulations express this antigen. CD4+2E3+ T cells show phenotypical and functional characteristics of nai;ve cells. The majority of them are CD29low, CD45RAhigh, CD49dlow, CD11alow, CD18low, and SLA-II-. After mitogen activation CD4+2E3+ T cells express high levels of IL-2 mRNA, but only traces of IFN-gamma or IL-4 mRNA. Indeed a minor percentage of cells stained positive for IFN-gamma when assessed by flow cytometry. Moreover, CD4+2E3+ T cells did not proliferate in response to the recall antigen lysozyme, although they did efficiently to the mitogen ConA. By contrast, CD4+2E3- T cells show phenotypical and functional characteristics of primed cells. They express markers associated to a memory phenotype, respond to the recall antigen lysozyme, and produce high amounts of IFN-gamma and IL-4.

Bronchial epithelium associated to lymphoid tissue does not selectively express vimentin.

The existence of a lymphoepithelium containing M cells in the bronchus-associated lymphoid tissue (BALT) of several species has repeatedly been questioned. In previous electron microscopical studies we failed to ultrastructurally identify these cells in the epithelium covering bronchial lymphoid tissue of adult rats. In the present study, we analyze immunohistochemically the expression of vimentin, an intermediate filament, reported to be a sensitive marker for rabbit M cells, in both BALT and Peyer's patches. Our results demonstrate, however, the absence of vimentin expression in the epithelium covering the bronchial lymphoid aggregates as well as in the lymphoepithelium of the Peyer's patches. On the contrary, both epithelia are strongly cytokeratin positive. Furthermore, numerous vimentin-positive lymphocytes appear in both lymphoid organs. Results are discussed from a view of the possible relationship between BALT and the so-called mucosae-associated lymphoid tissue (MALT).

Characterisation of the lpdA gene from Neisseria meningitidis by polymerase chain reaction, restriction fragment length polymorphism and sequencing.

P64k protein from Neisseria meningitidis is well recognised in sera from individuals convalescent from meningococcal disease or vaccinated with the Cuban antimeningococcal vaccine VA-MENGOC-BC. The presence of the protein in more than 80 meningococcal strains has also been verified. It is immunogenic in animal models and the antibodies elicited show bactericidal activity against meningococci. To further investigate at the molecular level whether lpdA, the gene coding for P64k protein, is conserved among different N. meningitidis strains, a total of 20 strains isolated from different geographic areas were differentiated on the basis of restriction fragment length polymorphism (RFLP) patterns after polymerase chain reaction (PCR) amplification of the lpdA gene and restriction endonuclease digestion with HpaII. Although a total of five different PCR-RFLP patterns were present, nucleotide sequence determination showed that identity levels were as high as 93-99% among the N. meningitidis strains analysed.

Ultrastructural changes in the adult rat thymus after estradiol benzoate treatment.

Although numerous authors have correlated high levels of circulating estrogens with thymic involution, a systematic analysis to date on the histological changes affecting the thymus gland in that situation is lacking. In the present study we report both histological and ultrastructural changes occurring in the thymus of adult Wistar rats which received a single dose either of 100 micrograms or 500 micrograms of estradiol benzoate. Both doses induced thymic involution which correlated well with histological changes observed in the lymphoid populations but also with profound modifications in the thymic epithelial component. Moreover, intrathymic erythro-and granulopoiesis, increased numbers of both macrophages and plasma cells, and important variations in the thymic vascular permeability occurred in estradiol benzoate treated rats. These results are discussed from the perspective that changes in both the non-lymphoid cell components of thymic microenvironments and vascular permeability are essential to understand the general effects of sex steroids on the immune system.

[Consensus document on vaccination against influenza in health care workers]. / Consenso sobre la vacunación frente a la gripe en el personal sanitario.

Health care workers (HCW) are included each year among risk groups for vaccination against influenza. However, vaccination coverage among this group in our country is very low, not exceeding 25%. Convinced that one of the best tools to increase this coverage among professionals in our country are the scientific evidence, 19 scientific societies and associations professionals bringing together health professionals more directly related to influenza as an health problem, and the General Nursing Council, met to discuss and develop this consensus document in order to inform HCW about the appropriateness of their vaccination against influenza and the benefits that flow from it for themselves, for their patients and for the rest of the population. This recommendation is based on 3 pillars: argument of necessity, ethics and exemplary.