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Biomedical subjects

M Di Muzio

Publications and source records attributed to M Di Muzio.

At least 37 records · Page 2Linked to original sources

[Anatomical and functional characteristics of the myocardial interstitial space].

The extracellular matrix plays an important role in biological processes, for example cellular adhesion, proliferation, migration and differentiation. Many of the cell-cell and cell-matrix interactions are mediated by extracellular matrix components and by their respective membrane receptors. Important pathophysiological processes occur through these interactions of which ontogenesis tissue differentiation and reconstruction, many inflammatory and immunological events and metastatic processes and invasion. The myocardium is made of muscular, vascular and connective components that exist in a state of equilibrium based on their relative proportions, integral structures, and on their physical and chemical characteristics. The Authors have described molecular events that lead to the organization of the cardiac tissue in physiological conditions and to its reorganization in pathological situation. Furthermore they have evaluated the role of fibronectin, a glycoprotein of the extracellular matrix in the initial phase of cardiac ischemia.

Extracellular Space↗

[Role of interstitial myocardium in ischemia-reperfusion injury: experimental data and clinical implications].

Myocardial interstitium plays an important role in the regulation of cardiac function compared with myocytes and it is actively involved in ischemia-reperfusion damage and in the acute and chronic remodelling during ischemic heart diseases. Myocardial post-ischemic oedema seems to interfere in this process. Myocardial oedema is able to induce structural alterations, to reduce myocardial function and to activate the renin-angiotensin-aldosterone system. Angiotensin II and aldosterone seem to be the cause of myocardial fibrosis that is detected during ischemic heart disease. Post-ischemic vascular permeability alterations have a similar role. In clinical conditions, ACE-inhibitors have important effects on cardioreparation and are able to improve cardiac function and reduce early and late mortality. The effects of myocardial oedema reduction (i.e. hypertonic reperfusion) on ischemia-reperfusion damage and myocardial fibrosis are still to clarify. A reduction in myocardial fibrosis may improve cardioreparation and prevent congestive heart failure, following ischemic heart disease.

Acute Disease↗

Simian virus 40-like DNA sequences in human pleural mesothelioma.

Mesotheliomas are pleural, pericardial, or peritoneal neoplasms frequently associated with asbestos exposure, and it is estimated that over the next twenty years up to 80,000 new cases are expected in the USA alone. We found simian virus 40-like DNA sequences in 29 of 48 mesotheliomas studied (60%) and demonstrated simian virus large-T antigen expression in 13 of 16 specimens. The matching lung samples did not contain simian virus 40-like sequences; however, they contained asbestos. These findings are to our knowledge the first demonstration of a physical link between DNA virus-like sequences and human mesothelioma. We suggest that a simian virus 40-like virus may act independently or as a co-carcinogen with asbestos. Moreover, the selective large T antigen expression by mesothelioma and not by the surrounding pulmonary parenchyma may have both diagnostic and therapeutic implications.

Adult↗

[From myocardial hypertrophy to heart failure: role of the interstitium].

In the progression from myocardial hypertrophy to heart failure, abnormalities in the interstitial space of the heart seem to play a critical role. The formation of an extracellular oedema and the alterations in coronary subendocardial perfusion are associated with the development of interstitial fibrosis. Cardiac experimental studies documented the presence of augmented interstitial fluid volume and pressure and a subsequent remodelling of the fibrillar network of the extracellular space of the myocardium during the phases of the cardiovascular response to a sudden overload. Variations of the Starling's forces balance caused by enhanced endothelial permeability or due to an impairment of cardiac lymphatic drainage may contribute to the development of an acute heart failure. During stable hyperfunction, the organization of a chronic oedema should account for interstitial changes in the hypertrophic myocardium. Reactive fibrosis seems to be under hormonal control. The activation of the renin-angiotensin-aldosterone system is responsible for interfascicular and intercellular accumulation of fibrillar collagen within the cardiac interstitium. Perivascular fibrosis in the subendocardium may impair intramyocardial distribution of coronary flow. When an inadequate hypertrophy occurs, because of an elevation in ventricular wall stress, myocardial oxygen consumption rises and this may lead to the exhaustion of coronary blood flow reserve in the subendocardial layers. This underperfusion may be responsible for the development of myocardial ischemia. Coronary hemodynamic changes in the microcirculation as those prompted by interstitial alterations may contribute to the onset of myocyte necrosis and to the formation of restorative fibrosis. The progressive mechanical overload of the spared hypertrophied myocytes could explain the initiation of a positive feedback mechanism which perpetuates endomyocardial perfusion impairment, interstitial oedema and remodelling, finally, causing myocyte deaths and fibrous tissue proliferation. These structural alterations and their pathophysiological counterparts appear to be closely related to the evolution from compensatory hypertrophy to chronic myocardial failure in hypertrophic heart disease.

Acute Disease↗

[The congenital absence of the permanent upper lateral incisors with the persistence of the deciduous canines in a subject of the Iron Age from the Sulmona (AQ) necropolis].

The paper reports a case of bilateral agenesia of the permanent upper lateral incisors associated with the persistence of the deciduous eye teeth placed between the first premolars and the permanent canine teeth which, in turn, had emerged in place of the agenetic lateral incisors (situs dentis inversus) in a adult male from the Iron Age whose skeletal remains were exhumed from tomb no. 58 of the Sulmona necropolis (AQ). The authors place the case in the context of agenesia as found both in today's population and in ancient times.

Adult↗

Poly-plethysmographic study on the effects of ritodrine on the cardiovascular system of patients in labour.

The effects of ritodrine infusion on the cardiovascular system of six women in threatened or premature labour are reported. In contrast to other betamimetics, ritodrine caused a moderate rise in systolic blood pressure, the corresponding fall in diastolic pressure leading to a widened pulse pressure but no risk of hypotension. Ritodrine caused a rise in cardiac output, and was well tolerated by the patients. Special care should be taken in treating patients with known heart disease.

Adolescent↗

Basal lamina reduplication in malignant epithelioid pleural mesothelioma.

Malignant mesothelioma of the pleura is divided in three morphological variants: epithelioid, sarcomatous, and biphasic. Histological similarities between epithelioid malignant mesothelioma (EMM) and lung adenocarcinoma are responsible for the difficult differential diagnosis. Monoclonal antibodies are useful for distinguishing the two neoplasms through immunohistochemical phenotyping, although many cases require ultrastructural characterization for definitive diagnosis. In this study, transmission electron microscopic observations of EMM were compared with those of peripheral adenocarcinoma of the lung (PAL). More specifically, the morphology of the basal lamina is described in 23 cases of EMM and 12 cases of PAL. Reduplication of the basal lamina (RBL) was found in 11 cases (48%) of EMM and in none of the PAL cases. The same cases were immunostained for type IV collagen and the localization of this basement membrane component corresponded to the areas where basal lamina was observed. Since RBL has been associated with neoplastic differentiation in other tumors, this novel feature in EMM needs to be evaluated in future prognostic studies in malignant mesothelioma of the pleura. Moreover, RBL expression in EMM may be an additional ultrastructural parameter used in the differential diagnosis between EMM and adenocarcinoma.

Adenocarcinoma↗