Biomedical subjects

Ana Romero

Publications and source records attributed to Ana Romero.

5 recordsLinked to original sources

PubMed2006

[Diffuse cutaneous reticulohistiocytosis].

The reticulohistiocytoses make up a heterogeneous group of diseases whose origin lies in an accumulation of cells of histiocytic lineage in different tissues and primarily in the skin. Three main clinical forms have been described (multicentric, solitary, diffuse cutaneous), which present with identical histological, ultrastructural and immunohistochemical characteristics. We present a case of diffuse cutaneous reticulohistiocytosis, which is the least common clinical pattern in the spectrum of this disease.

Biopsy↗

PubMed2006

Multilocular cystic renal cell carcinoma : a report of 45 cases of a kidney tumor of low malignant potential.

The 2004 World Health Organization (WHO) classification of kidney tumors recognizes multilocular cystic renal cell carcinoma (MCRCC) as a rare variant of clear cell renal cell carcinoma with a good prognosis. Available information on its clinical significance is limited. The study cohort included 45 MCRCC cases classified according to 2004 WHO criteria obtained through a multi-institutional international search. Most patients had unilateral MCRCC with no side predominance that was found incidentally; 62% were men, but women had tumors at an earlier age (P = .385). MCRCC occurred slightly more often in men than in women (1.7:1). At diagnosis, 82% of patients had stage T1 and 16%, stage T2; 1 patient had stage T3. The Fuhrman grade was 1 (62%) or 2 (38%), with smaller tumors (<or=4 cm) most likely Fuhrman grade 1 (P = .911). All 45 patients were alive with no evidence of disease at mean follow-up of 66.1 months, confirming an extremely good prognosis after surgery and a 5-year disease-specific survival rate of 100%. To rename this tumor as multilocular cystic renal cell neoplasm of low malignant potential might help urologists approach the patients conservatively.

Adult↗

PubMed2004

A hepatitis C virus-encoded, nonstructural protein (NS3) triggers dysfunction and apoptosis in lymphocytes: role of NADPH oxidase-derived oxygen radicals.

The persistent infection caused by hepatitis C virus (HCV) is presumably explained by a deficient immune response to the infection, but the basis for the inefficiency of immune-mediated virus eradication is not known in detail. This study addresses mechanisms of relevance to dysfunction of cytotoxic lymphocytes in HCV infection, with a focus on the role of phagocyte-derived oxygen radicals. We show that NS3, a nonstructural, HCV-encoded protein, induces a prolonged release of oxygen radicals from mononuclear and polymorphnuclear phagocytes by activating a key enzyme in radical formation, the reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. The NS3-activated phagocytes, in turn, induced dysfunction and/or apoptosis in three major subsets of lymphocytes of relevance to defense against HCV infection: CD3+/56- T cells, CD3-/56+ natural killer (NK) cells, and CD3+/56+ NKT cells. Two inhibitors of the NADPH oxidase, histamine and diphenylene iodonium, suppressed the NS3-induced oxygen radical production and efficiently protected lymphocytes against NS3-induced apoptosis and dysfunction. In conclusion, we propose that NS3, by triggering oxygen radical formation in phagocytes, may contribute to the dysfunction of antiviral lymphocytes in HCV-infected liver tissue and that strategies to circumvent oxidative stress may be useful in preventing HCV-associated carcinogenesis and facilitating lymphocyte-mediated clearance of infected cells.

Apoptosis↗

PubMed2004

Activation of cytotoxic lymphocytes by interferon-alpha: role of oxygen radical-producing mononuclear phagocytes.

A significant part of the therapeutic benefit of interferon-alpha (IFN-alpha) therapy in malignant diseases and in chronic viral infections is assumed to result from activation of lymphocytes with natural killer (NK) and T cell phenotype. In tumor tissue and in chronically infected tissue, the function and viability of these lymphocytes are frequently impaired. Mononuclear phagocyte (MP)-derived reactive oxygen species (ROS) have been proposed to contribute to the lymphocyte suppression in these tissues. Here, we report that three types of human cytotoxic lymphocytes of relevance to immunoactivation by IFN-alpha, CD3epsilon+/8+/56- T cells, CD3epsilon-/56+ NK cells, and CD3epsilon+/56+ NK/T cells became anergic to IFN-alpha induction of the cell-surface activation marker CD69 after exposure to autologous MPs in vitro. In addition to their incapacity to express CD69, cytotoxic lymphocytes acquired features characteristic of apoptosis after incubation with MPs. The lymphocyte apoptosis and nonresponsiveness to IFN-alpha were prevented by two inhibitors of reduced nicotinamide adenine dinucleotide phosphate oxidase-dependent formation of ROS in MPs, histamine dihydrochloride and diphenylene ionodonium, as well as by catalase, a scavenger of ROS. We conclude that MP-derived ROS may negatively affect IFN-alpha-induced immunostimulation and propose that ROS inhibitors or scavengers may be useful to improve lymphocyte activation during treatment with IFN-alpha.

Antigens, CD↗

PubMedDate not supplied

Synchrony in human, mouse and bacterial cell cultures--a comparison.

Growth characteristics of synchronous human MOLT-4, human U-937 and mouse L1210 cultures produced with a new minimally-disturbing technology were compared to each other and to synchronous Escherichia coli B/r. Based on measurements of cell concentrations during synchronous growth, synchrony persisted in similar fashion for all cells. Cell size and DNA distributions in the mammalian cultures also progressed synchronously and reproducibly for multiple cell cycles. The results demonstrate that unambiguous multi-cycle synchrony, critical for verifying the absence of significant growth imbalances induced by the synchronization procedure, is feasible with these cell lines, and possibly others.

Animals↗