Biomedical subjects

M P Corsi

Publications and source records attributed to M P Corsi.

6 recordsLinked to original sources

PubMed2001

Immunosenescence and infectious diseases.

Infectious diseases are major causes, with malignancies, of morbidity and mortality in the elderly. Increased susceptibility to infections may result from underlying dysfunction of an aged immune system; moreover, inappropriate immunologic functions associated with aging can determine an insufficient response to vaccines. Impairments of cellular, humoral and innate immunity in the elderly, contributing to increased incidence of infectious diseases, are discussed in this review.

Aging↗

PubMed2000

Coagulation and cancer: implications for diagnosis and management.

Coagulation disorders are a common problem in neoplastic patients and many factors contribute to increase the risk of thromboembolic events in these patients. An hypercoagulable state is induced by malignant cells interacting directly with hemostatic system and activating the coagulation cascade. More sensitive tests to assess an hypercoagulable state in cancer patients have been developed; even though these tests are always altered in cancer patients, none of them possess a clinical significance in terms of predictive value for the occurence of thromboembolism and disease prognosis in the individual patient. The most frequent thromboembolic complications in cancer patients are deep vein thrombosis of the lower extremities and pulmonary embolism; therefore, disseminated intravascular coagulation, thrombotic thrombocytopenic purpura or haemolytic uremic syndrome are special manifestations of neoplastic disease. Diagnosis of idiopathic deep vein thrombosis, in the absence of other risk factors, could indicate the presence of occult malignant disease; however, the need for an extensive work-up to detect malignancy is still controversial. Neoplastic patients showing a thromboembolic event should be treated with unfractioned heparin or, alternatively, with low molecular weight heparins. In order to prevent recurrence, the administration of heparin should be associated and followed by an oral anticoagulant drug. In recent years new approaches in anti-aggregation therapy have been studied, such as COX-inhibitors, cicaprost and ReoPro; further studies are needed to determine the usefulness of these molecules in treatment of malignancies.

Antineoplastic Agents↗

PubMed2000

Cell proliferation and apoptosis in the immune system in the elderly.

Loss of the cell proliferative capability and involution of tissues and organs are among the most important phenomena that characterize the aging process. Some of the aged-linked immune dysfunctions could be partly due to a dysregulation of apoptotic processes and to a lower responsiveness of aged lymphoid cells to activation and proliferation signals. The main changes in proliferative activity and cell death during aging and their impact on the process of immunosenescence are discussed. In fact, a very important function that has been suggested to deteriorate with age and to play a major role in the aging process is the capability of cells from aged subjects to respond to mitogenic stimuli and, consequently, to undergo cell proliferation. However, the cellular activation processes are very complex and the proliferative responses can follow different interconnected signal transduction pathways, and only some of them appear to be modified during age. Moreover, cell growth, immunosenescence, and longevity are strictly interconnected and deeply related to programmed cell death or apoptosis. The cellular equilibrium between cell survival and proliferation, on the one hand, and programmed cell death, on the other hand, seems to be unbalanced with advancing age, although in each type of immune cell it could be differentially modulated, resulting in a variety of clinicopathological consequences. Thus, cell proliferation and cell death are two physiologically active phenomena closely linked and regulated and a failure of these mechanisms determines profound dysregulations of cell homeostasis with major consequences in immune functioning and the onset of autoimmune diseases and cancer, whose incidence appears to be increased in the elderly.

Aging↗

PubMed2000

[Blood coagulation changes and neoplastic pathology].

Cancer patients show an increased susceptibility to develop thromboembolic diseases, suggesting that disorders of coagulation are very common in this pathology. Tumor cells possess the capacity to interact with the hemostatic system, activating the coagulation cascade and stimulating the prothrombotic properties of other blood cell components; the same events while inducing a hypercoagulable state, also contribute to the processes of tumor growth, neoangiogenesis and metastatic formation. Multiple risk factors associated with malignant disease contribute to the hypercoagulability state: stasis induced by prolonged bed rest, vascular invasion by the tumor and iatrogenic complications including the use of central vein catheters and chemotherapy. Several tests have been developed to assess the hypercoagulable state, however their clinical significance still needs to be defined, especially in terms of their predictive value for thrombosis. Clinical manifestations vary from localized deep venous thrombosis (DVT) or pulmonary embolism, more generally associated with solid tumors, to disseminated intravascular coagulation, frequent in hematologic malignancies and metastatic cancer. Diagnosis of idiopathic DVT, in the absence of other risk factors, could indicate the presence of occult cancer, but the usefulness of an extensive work-up to detect malignancy in terms of cost to benefit ratio still has to be demonstrated. Patients with cancer and thromboembolism must be treated with anticoagulant therapy; a large number of studies have shown that either low molecular weight heparins or standard unfractionated heparin for the treatment of acute deep vein thrombosis in hospitalized patients are equally safe and effective; however, the first treatment has been reported to be associated with a lower mortality. After an episode of thrombosis the patients should be protected by a long term course of oral anticoagulation, remaining high the risk of recurrence for as long as the cancer is active.

Blood Coagulation↗

PubMed1999

The immune system in the elderly: I. Specific humoral immunity.

Profound and complex changes in the immune response occur during the aging process. Immunosenescence is reflected by a sum of disregulations of the immune system and its interaction with other systems. Many of the changes would appear to implicate age-related deficiencies of the immune responses. The term immunosenescence designates therefore a sort of deterioration of the immune function which is believed to manifest itself in the increased susceptibility to cancer, autoimmune disease, and infectious disease. Evidence has been accumulating from several studies which suggest an association between immune function and individual longevity. However, there are observations, especially in very old healthy people, that several immune functions are unexpectedly well preserved and substantially comparable to those observed in young subjects. These findings raise the question of whether the alterations that can be observed in the immune parameters of the elderly are a cause or a result of underlying disease processes. Moreover, studies on centenarians revealed a remodeling of the immune system rather than a deterioration, suggesting that the changes observed during immunosenescence do not correspond to immunodeficiency. The underlying mechanisms of these events are however still unclear. The purpose of the present review is to assess the status of research on the immunobiology of aging. In this first section, we focus attention on the B cell biology of aging. In clinical practice, the changes in humoral immune responsiveness and antibody-mediated defense mechanisms could greatly influence the incidence and outcome of bacterial infections and autoimmune diseases as well as the response to vaccines.

Aged↗

PubMedDate not supplied

Immunophenotypical changes of T lymphocytes in the elderly.

BACKGROUND: Substantial changes in both representation and function of T lymphocyte subsets have been reported with advancing age. However, till now, no systematic studies focused on age-dependent changes in the expression intensity of the major T lymphocyte surface receptors. OBJECTIVE: The present study was undertaken in order to establish age-related differences in lymphocyte subpopulations by simultaneously measuring three surface antigens in young and elderly people. METHOD: Peripheral blood T cell subsets from 20 healthy elderly individuals and 15 healthy young adult donors were examined by means of a quantitative three-color flow cytometry method. RESULTS: Activated (HLA-DR+) and memory (CD45RO+) T cells, CD3+CD7- T lymphocytes, and cells expressing natural killer (NK) markers (CD3-CD56+ NK cells and CD3+CD56+ T lymphocytes) were expanded, whereas T lymphocytes expressing the adhesion molecule CD62L were lower in elderly compared with young donors. In addition to alterations in the percentages of T cell subsets during senescence, several changes in the intensity expression of T cell antigens were also detected. CD3 antigen expression was downregulated on total T lymphocytes as well as on the memory T cell subset, while CD56+ T cells exhibited increased CD3 levels. Moreover, CD2 expression, unchanged on NK cells, was upregulated on T lymphocytes from elderly subjects. CD3+CD7- T cells exhibited increased expression of CD8 antigen, while the intensity expression of HLA-DR on activated T cells and CD7 on both T and NK lymphocytes was decreased. T cells from elderly subjects also exhibited higher expression of CD50 and CD62L adhesion molecules as compared with young ones. CONCLUSION: These T cell antigen expression modulations during senescence, in addition to the alteration in the frequency of the various T lymphocyte subsets, could contribute to the complex remodeling of the immune function characteristic of the elderly.

Adult↗