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Biomedical subjects

A Salustri

Publications and source records attributed to A Salustri.

99 records · Page 6Linked to original sources
PubMed1983

Metabolic coupling, cumulus expansion and meiotic resumption in mouse cumuli oophori cultured in vitro in the presence of FSH or dcAMP, or stimulated in vivo by hCG.

The temporal changes of metabolic coupling between the mouse oocyte and the cumulus cells which follow hCG injection in vivo and FSH treatment in vitro were studied by measuring what fraction of [3H]uridine taken up by cumulus cells was transferred to the oocyte. Meiotic resumption and a partial coupling loss (to 35% of the initial value) spontaneously occurred in cumuli cultured in control medium. The addition of 1 microgram FSH/ml in vitro, or the injection of hCG in vivo caused a delay of about 3 h in both phenomena and a near total uncoupling, together with cumulus expansion. FSH caused uncoupling even if cumulus expansion was prevented by the addition of heparin. The presence of 2 mM-dcAMP prevented meiotic resumption in cumulus-enclosed oocytes and maintained a high level of co-operation for at least 6 h. The slow uncoupling observed at later times was due to cumulus expansion, because it was totally prevented by heparin. We suggest that metabolic co-operation with the cumulus oophorus and meiotic resumption are both regulated by FSH through variations of intracellular levels of cAMP.

Animals↗
PubMed1982

[Influence of follicular cells on energy metabolism of oocytes in growing mice].

To investigate to what extent follicle cells can influence the energy metabolism of growing oocytes and thus regulate their development, we have compared incorporation of 3H-leucine into proteins of denuded and follicle enclosed oocytes as related to the presence of different energy metabolites in the culture medium. The results indicate that a) oocytes have no endogenous reserves and that are dependent on the presence of exogenous pyruvate for their viability; b) follicular cells possess an energy reserves that can be utilized by the germinal cells; c) follicular cells mediate the utilization of exogenous glucose by growing oocytes. We can speculate that follicular cells transform glucose in pyruvate, utilizable by isolated oocytes, or they stimulate glucose uptake and glycolysis of the oocytes, as suggested by metabolic cooperativity for 2deoxy-D-glucose.

Animals↗
PubMed1982

Observations on the molecular components stabilizing the microtubular system of the marginal band in the newt erythrocyte.

Microtubules have been classified as either stable or labile, according to their resistance towards depolymerizing agents. The highest stability belongs to those organized in composite structures, in which many other proteins are associated with the tubulin. Among these microtubular systems, the marginal band of amphibian erythrocytes is unusually stable. This system can be readily isolated from Triturus red blood cells, and therefore lends itself very readily to ultrastructural and biochemical analyses. Immunofluorescence and electrophoretic analyses of the isolated bands reveal 14 components, among which tubulin, actin, myosin and a 90K glycoprotein were identified. Tannic acid-glutaraldehyde fixation reveals a conspicuous opaque material surrounding the microtubules. Cationized ferritin binding suggests the presence of anionic sites. Moreover, neuraminidase causes the disorganization of the microtubule-associated opaque material. The 90K glycoprotein is presumed to be related to the unusual stability of the microtubular system forming the marginal band.

Actins↗
PubMed1980

[In vitro culture of oocytes from growing mice: behavior in defined medium and in the presence of follicular cells].

To approach the problem of the possible role of granulosa cells in oocyte growth we utilized different systems for the culture in defined medium, isolated oocyte culture in "conditioned medium" from follicle culture, isolated oocyte-follicle cells coculture. Tests for metabolic functions indicate that the oocytes maintain the same steady level of 3H leucine incorporation and fail to grow in all of the culture systems considered. In isolated follicle culture, however, granulosa cell enclosed oocytes increase in volume. The results support the hypothesis that junctional association between oocytes and granulosa cells must be maintained to promote oocytes growth "in vitro".

Animals↗
PubMedDate not supplied

Prognostic value of dipyridamole sestamibi single-photon emission computed tomography and dipyridamole stress echocardiography for new cardiac events after an uncomplicated myocardial infarction.

A high-dose dipyridamole stress test (0.84 mg/kg in 6 minutes) with simultaneous sestamibi single-photon emission computed tomographic (SPECT) and echocardiographic imaging was performed in 89 patients before hospital discharge after an uncomplicated myocardial infarction. The aim of this study was to determine the prognostic value of these tests for new cardiac events and to compare the relative values of SPECT and echocardiography in a postinfarction dipyridamole stress test. Two years after infarction, nine patients (10%) had died, five patients (6%) had suffered a nonfatal reinfarction, and 14 patients (16%) had been readmitted to the hospital for a revascularization procedure. Cardiac death had occurred in 5 (10%) of 48 patients with a positive SPECT versus 4 (10%) of 41 with a negative SPECT (difference not significant) and in 6 (19%) of 31 with a positive echocardiogram versus 3 (5%) of 56 with a negative echocardiogram (p = 0.05). Cardiac death or reinfarction had occurred in 8 (17%) of 48 patients with a positive SPECT versus 6 (15%) of 41 with a negative SPECT (difference not significant) and in 6 (19%) of 31 with a positive echocardiogram versus 8 (14%) of 56 with a negative echocardiogram (difference not significant). Thus the predictive value of the dipyridamole stress test for new cardiac events after an uncomplicated myocardial infarction was limited, irrespective of the method used to detect ischemia. Reversible perfusion defects were identified more frequently than new wall motion abnormalities but did not predict late events. A positive dipyridamole echocardiogram was associated with a higher late mortality rate but did not predict other cardiac events.

Angioplasty, Balloon, Coronary↗
PubMedDate not supplied

Safety and feasibility of dobutamine-atropine stress echocardiography in patients with ischemic left ventricular dysfunction.

The aim of this study was to analyze whether left ventricular dysfunction affects the safety and feasibility of high-dose dobutamine-atropine stress echocardiography. We examined the results of the test in 318 consecutive patients who were referred for high-dose dobutamine-atropine stress echocardiography and also underwent diagnostic cardiac catheterization. Forty-four patients had a left ventricular ejection fraction of 25% or less (mean, 21%; range, 15% to 25%). In the entire group of 318 patients, no serious complications (death, myocardial infarction, or ventricular fibrillation) occurred. The overall feasibility of completing the test was excellent (97%). A trial fibrillation occurred in four patients, nonsustained ventricular tachycardia in 12, and sustained ventricular tachycardia in one. A decrease in systolic blood pressure of greater than 40 mm Hg or a peak systolic pressure of less than 80 mm Hg was present in eight cases. In the group with an ejection fraction of 25% or less, there was a higher rate of significant tachyarrhythmias (14% versus 5%; p = 0.03), whereas the feasibility of the test was slightly lower (89%; p < 0.01), but no difference for hypotension was found. By multivariate analysis, a history of tachyarrhythmias was the only predictor of stress-induced arrhythmias. Advanced left ventricular dysfunction does not represent a contraindication for dobutamine-atropine stress testing.

Adrenergic beta-Agonists↗
PubMedDate not supplied

Three-dimensional echocardiography of a flail tricuspid valve.

A 71-year-old man with an old myocardial infarction and blunt chest trauma 2 years previously came to our hospital with increasing dyspnea. Three-dimensional echocardiography was performed and a ruptured papillary muscle with flail anterior tricuspid valve was demonstrated from a surgical perspective (electronic atriotomy). These findings were confirmed during open-heart surgery with close similarity.

Aged↗
PubMedDate not supplied

Hyaluronan and proteoglycans in ovarian follicles.

Proteoglycans are macromolecules formed by a protein backbone to which one or more glycosaminoglycan side chains are co-valently attached. They can be secreted by the cells, retained at the cell surface, or stored in intracellular vacuoles. Hyaluronan is an extremely long glycosaminoglycan which, at variance with other glycosaminoglycans, is released into the extracellular matrix as a free polysaccharide not co-valently linked to a core protein. Both proteoglycans and hyaluronan influence many aspects of cell behaviour by multiple interactions with other molecules. They are involved in matrix formation, cell-cell and cell-matrix adhesion, cell proliferation and migration, and show co-receptor activity for growth factors. Both proteoglycan and hyaluranon synthesis change significantly during ovarian follicle development and atresia. This review describes the structure of these molecules and their possible function in ovarian physiology.

Animals↗