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Biomedical subjects

G Fernández Alonso

Publications and source records attributed to G Fernández Alonso.

8 recordsLinked to original sources
PubMed2001

Chromosomal alterations in atherosclerotic plaques.

Alterations of chromosomes 7 and 11 have been involved in the progression of atherosclerosis. Twenty-three carotid endarterectomy specimens were studied for the presence of alterations in chromosomes 7 and 11, and fibroblastic growth factor-3 (FGF-3) gene amplification. Besides classic histological stainings, immunophenotyping of cellular and vascular components and fluorescence in situ hybridization (FISH) were performed. At the caps, unstable plaques (n=18) showed inflammatory infiltration of macrophages, smooth muscle cells, and T-lymphocytes. Specifically in these regions, the FISH showed varying percentages of trisomy (15/18) and tetrasomy (8/15) of chromosome 7. In four cases polisomy 7 was noted in some nuclei. Monosomy of chromosome 11 and gene amplification of FGF-3 gene was observed. The FISH of the five stable plaques and normal arterial walls showed no chromosome alterations; furthermore, chromosome 3, which is not involved in atherosclerotic progression, presented a normal ploidy of smooth muscle cells in stable and unstable plaques and normal arterial walls. In conclusion, chromosome 7 and 11 alterations and FGF-3 gene amplification are components of unstable plaques, and might contribute to the evolution of stable plaques into complicated plaques.

Adult↗
PubMed2000

[Proliferative activity and chromosomal alterations of smooth muscle cells in atherosclerosis].

Atherosclerosis is the most frequent cause of death in industrialized countries. Lesions are characterized by lipid deposits, focal thickening of the arterial wall with proliferation of smooth muscle cells (SMC), mononuclear infiltrates and neoformed vessels. In this paper, we studied the proliferative characteristics and cytogenetic alterations of SMC. These cells, expressing specific muscular actin, were diploid with an increased proliferative index for PCNA. A high percentage of SMC showed intense expression of p53. There were signs of chromosomal instability, being the most frequent findings chromosome 7 trisomy and chromosome 11 monosomy. Additionally, the gene for FGF-3 showed a marked amplification. These findings strongly suggest that SMC proliferation is active, and is related to the accumulation or mutation of the p53 oncoprotein. It also presents specific chromosomal alterations in close relation with growth factors. According to these findings SMC hyperplasia in the atherosclerosis plaque may be considered as a cellular clonal expansion.

Arteriosclerosis↗
PubMed1998

Cardiac involvement in acquired immunodeficiency syndrome--a review to push action. The Committee for the Study of Cardiac Involvement in AIDS.

As more effective therapies have produced longer survival times for human immunodeficiency virus (HIV)-infected patients, new complications of late-stage HIV infection including HIV-related heart disease have emerged. Almost any agent that can cause disseminated infection in patients with acquired immunodeficiency syndrome (AIDS) may involve myocardium, but clinical evidence of cardiac disease is usually overshadowed by manifestations in other organs, primarily the brain and lungs. Cardiac abnormalities are found at autopsy in two-thirds of patients with AIDS, and more than 150 reports of cardiac complications have been published. Cardiac involvement in HIV disease includes pericardial effusion, myocarditis, dilated cardiomyopathy, and/or endocardial involvement at any stage of the disease. This review deals with all the cardiac manifestations of AIDS and serves to highlight two problems and one indication. First of all, there are very few clinical studies. Current knowledge is based almost exclusively on echocardiography and autopsy studies. Observational or clinical trials would be useful. Second, there exists very poor information on the impact of treatment; and epidemiologic and clinicopathologic studies are mandatory for obtaining detailed data concerning the mechanisms of myocardial damage in AIDS. Finally, because cardiac complications are often clinically inapparent or subtle in the initial stages, periodic screening of HIV-positive patients by electrocardiogram and echocardiogram is probably indicated. In addition, AIDS may also provide the opportunity to gain insights into the pathogenesis of little understood cardiac diseases such as lymphocytic myocarditis and dilated cardiomyopathy.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Is stunning prevented by ischemic preconditioning?

In a model of global ischemia in the isolated perfused rat heart, a 20 min ischemic period followed by 30 min of reperfusion induces a decrease in isovolumic developed pressure (LVDP) and +dP/dtmax to 61+/-6% and 61+/-7% of baseline, respectively. Left ventricular end-diastolic pressure (LVEDP) increases to 36+/-4 mmHg at the end of the reperfusion period. No significant necrotic area as assessed by triphenyltetrazolium chloride (TTC) was detected at the end of the reperfusion period. By an immunohistochemical method using antiactin monoclonal antibodies 10.8+/-1.9% of unstained cells were detected in the stunned hearts and 10.3+/-1.2% in control hearts. Preceding the ischemic episode with a cycle of 5 min of ischemia followed by 10 min of reperfusion (ischemic preconditioning) protected contractile function. LVDP and +dP/dtmax now stabilized at 89+/-5% and 94+/-5% of baseline respectively. LVEDP was 20+/-2 mmHg at the end of the reperfusion period. The protection of contractile dysfunction after 20 min of ischemia was achieved also by early reperfusion of low Ca2+-low pH perfusate. With this intervention LVDP stabilized at 87+/-5% of baseline. LVEDP was 12+/-2 mmHg at the end of the reperfusion period. A positive inotropic intervention induced by a modified postextrasystolic potentiation protocol at the end of the reperfusion period increases LVDP to levels higher than baseline in the stunned hearts. However, these values were less than those obtained in control hearts. Ischemic preconditioning significantly increased the maximal inotropic response. Therefore, ischemic preconditioning diminishes the contractile dysfunction of early stunning.

Animals↗
PubMed1997

Fc gamma receptor-dependent clearance is enhanced following lipopolysaccharide in vivo treatment.

Lipopolysaccharides (LPS) occupy centre stage in the pathogenesis of gram-negative sepsis. Although LPS are potent stimulators of the mononuclear phagocyte system (MPS), their effects on immune complex (IC)-specific clearance have not yet been reported. In order to evaluate this issue, we examined the MPS function after LPS treatment by measuring intravascular removal rate of syngeneic erythrocytes sensitized with specific immunoglobulin G (IgG) (EA). Our findings showed that LPS, directly or through the release of endogenous cytokines, enhance Fc gamma receptor (Fc gamma R)-dependent clearance. The EA uptake by liver, spleen and bone marrow was significantly increased leading to an effective clearance of immune complexes. Splenic antibody-dependent cellular cytotoxicity (ADCC), an in vitro indicator of Fc gamma R functionality, was also increased after in vivo LPS treatment. However, cytometric studies showed that endotoxin did not modify Fc gamma R expression on splenocytes, but markedly enhanced the expression of CD11b/CD18 (Mac-1), an adhesion molecule closely related to Fc gamma R activity. We conclude that LPS enhance Fc gamma R-dependent effector functions and suggest that this effect is mediated through alterations in adhesion molecules.

Animals↗
PubMed1987

[Fine-needle aspiration puncture of abdominal masses using echographic monitoring. Cytological diagnosis and experience with biological markers].

43 fine needle aspiration biopsies of abdominal masses were performed under echographic guide. Cytologic diagnosis was done with routine techniques. Tumor, lineage and origin biologic markers were detected by immunocytochemical methods. Sensibility, specificity and accuracy of this procedure were evaluated. Advantages of the method are discussed.

Abdomen↗