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Biomedical subjects

R Carraro

Publications and source records attributed to R Carraro.

At least 37 records · Page 2Linked to original sources
PubMed1990

Adipose tissue islets: tissue culture of a potential source of fat cells in the adult rat.

Collagenase digests of adipose tissue of the 3 to 4-month-old rat contain groups of 20-100 tightly arranged cells (islets) that copurify with the free-floating fat cells. When cultured along with mature adipocytes the islets give rise to cells, initially fibroblast-like, which rapidly proliferate, acquire lipid droplets, and differentiate into small adipocytes within 4-6 days without the addition to the medium of the agents usually required to produce differentiation in stromal-vascular preadipocytes. Differentiation of these cells is independent of confluence and begins as early as day 2 of culture. The proportion of islet-derived cells that differentiate is directly correlated with the number of mature adipocytes simultaneously present in the culture (r = .709; P less than 0.001). Culture medium exposed to mature adipocytes demonstrated differentiation-promoting activity, suggesting a paracrine effect of these cells. Islets may in vivo constitute a source for newly formed adipocytes in the adult rat. The differentiation of these potential adipocytes may be regulated, at least in part, by the mature fat cells via a paracrine effect.

Adipose Tissue↗
PubMed1990

The transcranial Doppler ultrasonography in the evaluation of vasospasm and of intracranial hypertension after subarachnoid hemorrhage.

The transcranial doppler (T.C.D.) is a non-invasive technique useful for the evaluation of vasospasm and intracranial hypertension in patients with subarachnoid hemorrhage (S.A.H.). Eighteen patients with recent S.A.H. were studied by means of T.C.D. device: in 14 patients the source of bleeding was a ruptured aneurysm of the circle of Willis, while the remaining 4 presented a negative four-vessels angiography. All the patients were studied 5 and 10 days after the bleeding. Our data showed that the ultrasonographic demonstration of vasospasm and/or I.C.H. is clearly related to the clinical status of the patients. No significant T.C.D. difference was noticed between the "sine materia" S.A.H. patients and the ones with ruptured aneurysm.

Blood Flow Velocity↗
PubMed1990

Multiple symmetric lipomatosis. Ultrastructural investigation of the tissue and preadipocytes in primary culture.

Multiple symmetric lipomatosis (MSL) is characterized by enlarging, painless fat deposits in the neck and upper trunk. The pathogenesis of MSL is unknown. Owing to localization of MSL fat deposits in the neck and interscapular region, it has been suggested that they could originate from brown fat. However, the histological appearance of MSL adipose tissue is that of white fat, with prevailing monovacuolar adipocytes. Nevertheless, MSL adipocytes are smaller than adipocytes of the common white adipose tissue and show peculiar metabolic features. The ultrastructure of MSL lesions has been not described. The present work investigated the ultrastructural morphology of MSL adipose tissue and lipomatous adipocyte precursors maintained in long-term culture. Samples of lipomatous tissue were obtained from patients affected with MSL undergoing surgical lipectomy. Portion of the tissue was processed for electron microscopy; the rest was digested with collagenase, and isolated preadipocytes from the stromal-vascular fraction were cultured up to 15 days. Cultured cells were prepared for electron microscopy in situ and their morphology compared with human white adipose tissue preadipocytes and rat brown preadipocytes cultured in parallel. Results show the following. 1) Adipocytes of MSL are not monovacuolar and resemble the largest adipocytes that can be found in rat and human brown fat. 2) Some morphological features of MSL adipocyte precursors resemble brown adipocyte more than white: cultured MSL preadipocytes transiently develop large mitochondria with parallel cristae resembling those of the brown fat cell and maintain a multivacuolar lipid deposit in culture, i.e. a typical feature of brown preadipocytes. 3) Some morphological features suggest a neoplastic nature of MSL adipocytes. Taken together, these findings suggest that MSL is a neoplastic disease which could originate in brown fat.

Adipose Tissue↗
PubMed1988

Prolapse of atrioventricular valve leaflets in the setting of double orifice.

Prolapse of the valve leaflets is reported in 2 cases in the setting of double orifice atrioventricular valve. Diagnosis in the first case, an asymptomatic 8-year-old female, was achieved by echocardiography and consisted in prolapsing leaflets of a double orifice ("bridge type") mitral valve. The second patient, a 24-year-old male, died suddenly. Postmortem examination revealed prolapsing atrioventricular valves, with double orifice ("holy type") of the septal leaflet of the tricuspid valve. There was disruption of the penetrating atrioventricular bundle into multiple fragments with fasciculo-ventricular by-pass fibers.

Adult↗
PubMed1988

Lipid metabolism in lipoatrophic diabetes.

Some aspects of lipid metabolism were studied in 4 patients with a congenital lipoatrophic diabetes (LAD) associated to a type IV hyperlipoproteinemia. The analysis of lipoprotein composition, expressed as mg/dl, demonstrates a significant increase of VLDL mass and a significant reduction of HDL mass. The analysis of lipoprotein composition, expressed as per cent of total mass demonstrates an increase of the triglyceride content in all fractions and a significant reduction of the cholesterol and phospholipid content in HDL2 particles. Apo C-II, C-III0, C-III1 and C-III2 levels in lipoprotein fractions were normal in LAD patients. Lipoprotein lipase activity in omental adipose tissue, collected during laparoscopy in one patient was undetectable. The serum of this patient did not fully activate the lipoprotein lipase eluted from normal adipose tissue. In all patients the adipose tissue lipoprotein lipase activity in post-heparin plasma was blunted or near absent. Thus a reduced peripheral clearance of triglyceride-rich lipoprotein could be an important determinant of lipoprotein abnormalities in lipoatrophic diabetes.

Adipose Tissue↗
PubMed1987

[Another case of juvenile sudden death caused by anomalous origin of the right coronary from the left anterior sinus of Valsalva].

A second case of sudden death during athletic activity, due to anomalous origin of the right coronary artery from the left anterior sinus of Valsalva, is presented. Post-mortem examination disclosed widespread myocardiosclerosis involving the subepicardial layers of the posterior wall of the left ventricle. Submaximal exercise testing had been performed to evaluate the presence of a ventricular extrasystole on a basal ECG, but no significant ischemic alterations of the ST tract had been detected. This case proposes once again the uncertainties regarding the diagnostic sensitivity of the protocols for competitive sport fitness in revealing latent chronic ischemia.

Adult↗
PubMed1986

In vitro effects of glucidamine on adrenergic stimulated lipolysis and on lipoprotein lipase activity in human adipose tissue.

Glucidamine, a purified glycoprotein-mucopolysaccharide complex displays dose-dependent lipolytic effect on human adipose tissue in vitro. On adipose tissue lipoprotein lipase activity glucidamine exhibits an heparin-like effect in eluting the enzyme from the tissue stores to the medium of incubation. No activating effects of glucidamine on lipoprotein lipase eluted from human adipose tissue was observed.

Adipose Tissue↗
PubMed1986

Long-term survival in response to combined chemotherapy and radiotherapy in laryngeal small cell carcinoma.

Fourteen patients with small cell carcinoma of the larynx are studied. This represents the largest series, from a single institution, reported in the literature. This neoplasm is usually highly aggressive and the prognosis very poor, but, in our experience, combined chemo- and radiotherapy can significantly improve the clinical course of the disease. Three of six patients who received this combined modality treatment are still clinically disease-free more than six years after the initial diagnosis.

Aged↗
PubMed1986

[Hypertrophic cardiomyopathy and juvenile sudden death. A clinical case and re-evaluation of the problem].

A 29-year-old man with non-familiar hypertrophic cardiomyopathy died suddenly. The patient experienced recurrent episodes of palpitation both at rest and during exercise. M-mode and 2-D echocardiograms showed severe asymmetric septal hypertrophy (IVS/LVPW ratio 3:1) and systolic anterior motion of anterior leaflet of the mitral valve. The ECG demonstrated deep "Q" waves from the inferior leads and inverted "T" waves in V1 to V6, but failed to register arrhythmias. Holter monitoring had been planned in order to achieve information for pharmacologic therapy, but unfortunately the patient died during the stand-by. Postmortem examination showed severe asymmetric septal hypertrophy with fibrosis and wide-spread "myocardial disarray".

Adult↗
PubMed1985

Turnover of phospholipids isolated from fractions of lung lavage fluid.

To clarify the steps following surfactant secretion, we injected adult rabbits with radioactive palmitate, lavaged the airways, removed the cells, separated by ultracentrifugation lavage components into two fractions (B and C), and followed the labeling of phospholipids of these fractions. The results were compatible with the view that total and saturated phosphatidylcholine are transferred from B to C. Furthermore, the fluxes of total and saturated phosphatidylcholine through fraction C (0.45 and 0.30 mumol . h-1 . g lung-1, respectively) were compatible with the actual estimates of surfactant recycling. The labeling of phosphatidylglycerol ruled out a simple precursor-product relationship between B and C but was compatible with a nonideal first-order relationship. The labeling of phosphatidylinositol, cardiolipin, and phosphatidylethanolamine was incompatible with the existence of a direct precursor-product relationship between B and C. The labeling of total and saturated phosphatidylcholine suggests that fraction B may be made by active surfactant, whereas fraction C may contain surfactant modified for reuptake or for reuptake and catabolism.

Animals↗
PubMed1984

Heterogeneity of alveolar surfactant in the rabbit: composition, morphology, and labelling of subfractions isolated by centrifugation of lung lavage.

Rabbit alveolar saturated phosphatidylcholine (SPC) can be separated by differential and density gradient centrifugation of lung lavage into three fractions. One fraction ('B'), which is analogous to conventionally prepared alveolar surfactant, contains 46.0 +/- 5.9% (SD) of lavage SPC, and is made of large multilamellar vesicles or sheet-like structures. A second fraction ('C') does not sediment after centrifugation at 80 000 g for 90 min, contains 29.8 +/- 14.0% of lavage SPC, and a uniform population of small vesicles. This fraction incorporates 3H-palmitate administered intravenously with a small delay with respect to fraction 'B'. A third fraction ('D') contains almost all the cells of lavage and less than 5% of lavage SPC. We conclude that alveolar SPC consists of more than one compartment. The possible significance of isolated fractions is discussed.

Animals↗