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Biomedical subjects

A Angelini

Publications and source records attributed to A Angelini.

At least 109 records · Page 6Linked to original sources
PubMed1989

The morphology of the normal aortic valve as compared with the aortic valve having two leaflets.

We studied 30 normal aortic valves and 64 aortic valves with only two leaflets to examine their morphologic components. The components of the aortic valve are the leaflets, the sinuses, and the interleaflet triangles. The first part of our study shows the relationship of these component parts of the normal aortic valve to the other cardiac structures. The second part shows a wide variation in the architecture of valves having two leaflets. Having produced criteria for the number of sinuses and the number of leaflets, we discovered that previous criteria used in the definition of valves with two leaflets are inadequate when the whole valvular complex is considered. Only seven valves in the study have two leaflets supported by two sinuses. The evidence points to the other valves having started with three leaflets but becoming bicuspid during either intrauterine or postnatal life.

Adult↗
PubMed1988

Ultracytochemical localization of adenylate cyclase in early human placenta.

A cytochemical study was carried out on adenylate cyclase (AC) activity in the early human placenta. Samples of placental villi were incubated in a medium containing adenylyl-imidodiphosphate (AMP-PNP) as specific substrate. No AC reaction product was encountered in placenta villi taken at 5 and 7 weeks of pregnancy. AC activity appeared at 9 weeks. At 9 and 10 weeks, AC reaction product was localized on the basal plasma membranes and on apposed plasma membranes of the Langhans cytotrophoblast. At 11 weeks AC activity was also clearly visible on Langhans cytotrophoblast and syncytiotrophoblast apposed plasma membranes. No AC reaction product was ever detected on the syncytiotrophoblast microvillar membrane. These results are in agreement with biochemical studies that localize AC on the villous trophoblast plasma membranes associated with the fetal circulation.

Adenylyl Cyclases↗
PubMed1988

A histological study of the atrioventricular junction in hearts with normal and prolapsed leaflets of the mitral valve.

The mitral annulus is the point at which the atrial and ventricular walls meet the base of the mitral valve cusps. The suggestion that a variant of this arrangement termed "disjunction" was associated with prolapse of the leaflets prompted examination of the mitral atrioventricular junctions in seven normal hearts and six with prolapse owing to floppy mitral valves. A complete cord-like ring of connective tissue that encircled the atrioventricular junction and into which the three components were inserted at the same point was found in only one heart. The remaining hearts all showed a mixture of segments in which either the three components were inserted into a cord or simply met. Disjunction, defined as a separation of the atrial wall-mitral valve junction from the other component, the left ventricular wall, can occur both with and without a cord-like annulus. There was no significant difference in the number of segments around the left atrioventricular junction which showed disjunction in hearts with normal or prolapsing leaflets. The feature termed disjunction is an anatomical variation of the normal morphological characteristics of the left atrioventricular junction.

Aged↗
PubMed1988

Measurements of the dimensions of the aortic and pulmonary pathways in the human fetus: a correlative echocardiographic and morphometric study.

Thirty normal hearts from fetuses aborted at 10-33 weeks' gestation were measured directly and the results were compared with echocardiographic measurements in 20 normal live fetuses of 23-27 weeks' gestation. The diameters of the aorta, aortic isthmus, pulmonary arteries, and arterial duct were measured at standard levels and expressed as a ratio of the diameter of the ascending aorta. The ratios for the isthmus, the duct, and the right pulmonary artery were: 0.63 (0.11), 0.51 (0.13), 0.56 (0.10) respectively for the direct measurement and 0.73 (0.07), 0.7 (0.08), 0.62 (0.06) respectively at echocardiography. These results show that in mid-gestation the isthmus of the human fetus is not as small as that reported in animal models. This indicates that the distribution of the fetal circulation may not be the same either.

Aorta↗
PubMed1988

Catecholamine-induced cardiovascular disease in the spontaneously hypertensive and atherosclerotic turkey.

The interest evoked by the Broad Breasted White Turkey (BBWT) as an animal model for studying the cardiovascular damages produced by hypertension and catecholamines is mainly due to the fact that hypertension is spontaneous and tissue and circulating catecholamines, especially norepinephrine, are extremely high. In this paper we focused our attention on three characteristic pathophysiological features displayed by these animals which are strictly related, as well as in humans, to the elevated blood pressure values and to catecholamine action. We also described the possibility of modifying the development of some of these lesions with pharmacological interventions liable to antagonize the peripheral effects of norepinephrine and epinephrine. The dissecting aneurysm of the aorta accounts for 5-10% of sudden deaths in this animal strain. It can be prevented by lowering blood pressure, especially with beta-blockers, and facilitated by MAO-inhibitors. The degree of cardiac hypertrophy is remarkably high and unexpectedly characterized by the synthesis of a "fast" V1-like isomyosin with high Ca++ activated ATPase activity, oxygen consumption and speed of muscle shortening. Neither the reduction of the degree of cardiac hypertrophy, nor treatment with labetalol alone were able to modify this peculiar pattern. In spite of having very high levels of high-density-lipoproteins, which are known to be protective against atherosclerosis, this animal develops a severe atheromatous disease especially in the abdominal aorta, where the cellular growth has also been proven to be in vitro more pronounced than in the thoracic tract. Treatment with beta-blockers reduced the severity and extent of the lesion even in absence of a significant reduction in blood pressure.

Animals↗
PubMed1988

Seven-day storage of single donor platelets in polyolefin bags: clinical, biochemical, morphological and microbiological evaluation.

We compared the in vitro and in vivo function of fresh and stored platelet concentrates (PCs) collected by an automated continuous-flow blood cell separator (CS 3000 Fenwal) in a closed-system apheresis kit in order to evaluate the possibility of extending the storage time to seven days with the polyolefin container (PL-732). The initial 220 ml platelet volume (5.14 +/- 1.23 x 10(11) was divided into two parts. Half was transfused and the other half was stored for 7 days. All cultured units were negative for bacterial contamination. Mean counts for fresh and stored platelets were respectively 2.34 +/- 0.59 and 2.17 +/- 0.50 X 10(11)/100 ml of PCs (mean recovery 88.7 +/- 11.9%). The pO2 levels were maintained during storage (179.9 +/- 30.5 mmHg) but pCO2, pH, LDH, osmolality, glucose consumption, bicarbonates, ATP, and osmotic stress values changed significantly after 7 days storage. From a clinical point of view, in 14 patients receiving a total of 38 PC transfusions no statistically significant change in corrected post-transfusional levels was observed between fresh and stored PC. Biochemical and morphological data and clinical results suggest that PCs collected with CS-3000 blood cell separator in a closed system and stored for 7 days in polyolefin bags (PL-732) can be satisfactorily employed in clinical practice.

Blood Platelets↗
PubMed1988

Enrichment of marrow hemopoietic progenitor cells using a blood cell processor.

A total of 93 bone marrows (BM) from normal donors and patients were processed using the IBM-COBE 2991 blood cell washer to produce a concentrated buffy coat (BC) for either bone marrow transplantation (BMT) or cryopreservation for subsequent autologous BMT. The reduction in volume was 73.3 +/- 8.5% and nucleated blood cells (NBC) recovery was 87.1 +/- 9.1% of original marrow. Red blood cell (RBC) and platelet (PLT) contamination was reduced 64.5 +/- 10.9% and 41.2 +/- 24.1%, respectively. Clonogenic activity indicated that the NBC fraction was highly enriched in hematopoietic progenitor cells (greater than 100%) as assessed in vitro (CFU-GM). Results were not affected by diagnosis, initial marrow volume or cell count of the BM suspension. We conclude that this is a simple and reproducible method using blood bank, facilities and permits BC preparation from BM without significant loss of hematopoietic progenitor cells.

Bone Marrow Cells↗
PubMed1987

Pulmonary atresia with hypoplastic left ventricle.

We report a case with concordant atrioventricular connexion in association with pulmonary atresia and origin of the aorta from the right ventricle. The left ventricle was hypoplastic and the ventricular septum intact.

Heart Ventricles↗
PubMed1986

Changes in rat ventricular isomyosins with regression of cardiac hypertrophy.

The changes in ventricular isomyosin composition and Ca2+-activated ATPase activity occurring with regression of both hypertension and cardiac hypertrophy were investigated by using polyacrylamide gel electrophoresis under nondenaturing conditions, heavy chain peptide mapping, and an enzymatic assay. Eight control male Wistar rats and 14 two-kidney, one clip (Goldblatt II) hypertensive rats were studied from the fifth week of age. At 10 weeks of age, five Goldblatt II rats and four normotensive controls were killed. Five other Goldblatt II rats underwent nephrectomy of the ischemic kidney, which resulted in subsequent normalization of blood pressure. The remaining four control, four Goldblatt II rats, and five nephrectomized rats were killed at 15 weeks of age. Both the 10- and 15-week-old hypertensive rats had a significantly higher (p less than 0.001) biventricular weight to body weight ratio than the age-matched controls (3.84 +/- 0.76 X 10(-2) vs 2.75 +/- 0.25 X 10(-2); 5.93 +/- 2.26 X 10(-2) vs 2.65 +/- 0.17 X 10(-2]. The 15-week-old nephrectomized rats had a biventricular weight to body weight ratio (2.90 +/- 0.25 X 10(-2] close to that of age-matched controls and significantly lower (p less than 0.05) than that of age-matched hypertensive rats. In both the 10- and 15-week-old hypertensive rats left ventricular myosin Ca2+-activated ATPase activity was significantly lower (p less than 0.001) than in the age-matched controls (0.44 +/- 0.03 vs 0.59 +/- 0.06; 0.24 +/- 0.05 vs 0.48 +/- 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Progression and regression of cardiac hypertrophy in hypertensive rats: biochemical and molecular changes in ventricular myosin.

We investigated the changes in ventricular isomyosin composition and Ca2+-activated ATPase activity during progression and regression of hypertension and cardiac hypertrophy. Eight control male Wistar rats and 14 Goldblatt-II (two-kidney, one clip) hypertensive rats were studied from the 5th week of age. Five of the Goldblatt-II rats underwent nephrectomy of the ischaemic kidney after 5 weeks, with normalization of blood pressure. The hypertensive rats showed a higher biventricular weight to body weight ratio (P less than 0.02), a lower ATPase activity (P less than 0.005), and an increased expression of 'slow' isomyosins in comparison with the age-matched controls. These changes were more pronounced at 15 than at 10 weeks of age. The 15-week-old nephrectomized rats showed the same degree of cardiac hypertrophy, ATPase activity and isomyosin pattern as the age-matched controls. In conclusion, the changes in ventricular myosin observed during the progression of cardiac hypertrophy regressed after normalization of blood pressure and ventricular mass.

Animals↗
PubMed1986

Ventricular and aortic myosin in hypothyroid and hyperthyroid broad breasted white turkeys.

Hyperthyroidism, and alternatively hypothyroidism, were induced in spontaneously hypertensive broad-breasted white turkeys (BBWT) to see if these conditions influenced the pattern of Ca++-activated ATPase activity and isomyosin synthesis in the cardiac muscle. Nine animals were given thyroxine 500 micrograms p.o., 9 animals propylthiouracil 150 mg p.o., 6 animals placebo p.o. All animals were treated daily from the 27th to the 33rd week of age. The ventricular myosin Ca++-activated ATPase activity was assayed in all the animals; aortic smooth-muscle myosin light chains were analysed by mono- and two-dimensional gel electrophoresis, and myosin heavy chains by proteolytic mapping. No significant difference was found between the three groups in the ventricular myosin Ca++-activated ATPase activity. As for aortic myosin, a similar peptide map of heavy chains but a different phosphorylative level of the LC1 light chain was found in the three groups of animals. It is concluded that a thyroid-hormone modulation of contractile proteins in vascular smooth muscle, but not in cardiac muscle, exists in the broad-breasted white turkey.

Adenosine Triphosphatases↗
PubMed1985

Propranolol-induced changes in ventricular isomyosin composition in the rat.

The ventricular isomyosin composition in the rat is characterized by three isoenzymes, V1, V2, and V3, with high, intermediate, and low Ca++-activated ATPase activity, speed of muscle shortening, and contractile economy. In this study, we examined the effects of propranolol on ventricular isomyosin composition in the rat. Eight 4-week-old male Wistar rats were treated from 4 to 12 weeks of age with daily 10 mg/kg subcutaneous doses of propranolol; four control rats were given subcutaneous distilled water. At the end of the treatment period, the efficacy of beta blockade was confirmed by isoproterenol test in some rats from each group. After the rats were killed left ventricular myosin from both control and propranolol-treated animals was purified and tested for Ca++-activated ATPase activity. Ventricular isomyosin composition was studied by gel electrophoresis in non-denaturing conditions. Heart rate was significantly lower in the propranolol group, while no differences in blood pressure, body weight, or ventricular weight were found between the two groups. Lower Ca++-activated ATPase activity values and a higher expression of myosin isoenzymes V2 and V3 were found in propranolol-treated rats. Possible links between the observed shift in ventricular isomyosin composition and the well-known modifications in myocardial contractility and oxygen consumption occurring after chronic propranolol administration remain to be established.

Animals↗
PubMed1985

Radiation-induced coronary obstructive atherosclerosis and sudden death in a teenager.

An 18-year-old woman, affected by Hodgkin's disease and treated successfully with radiotherapy, died suddenly. The postmortem study showed an acute septal myocardial infarction in the presence of a severe focal atherosclerotic lesion of the anterior descending coronary artery. This suggests that radiation may contribute to the early development of coronary artery disease.

Adolescent↗
PubMed1985

The surface measurement of aortic atherosclerosis: critical survey and comparison with histologic findings.

Both the reproducibility of the surface measurements of aortic atherosclerosis and the agreement between gross inspective and histologic changes were evaluated. Aortas from male broad breasted white turkeys were chosen because of the high incidence of spontaneous and typical atherosclerotic lesions in this animal strain. Ten male turkeys were killed at 33 weeks of age. The aortas were removed including the iliac bifurcation and stained with Sudan III. Each aorta was processed blindly by four pathologists and a computerized planimeter to determine normal areas, sudanophilic areas and areas covered by plaques. The analysis of variance showed significant differences among the four pathologists' measurements of sudanophilic areas (P less than 0.01) and areas covered by plaques (P less than 0.001). The coefficients of variation among the four determinations made by one pathologist on the same aorta were 3.6% for total aortic area; 10.08% for sudanophilic area; 47.6% for the area covered by plaques. On each aorta histology was performed at the level where all the four pathologists recorded the same findings at inspection, namely a normal area, a sudanophilic area, and an area covered by plaques. Important discrepancies occurred between findings at inspection and those of histologic examination: the ten areas classified as "normal" by all the four pathologists at inspection were shown at histologic examination to be normal in only two cases. In one case a musculo-elastic layer and in seven cases a fibro-elastic layer were found. The ten areas classified as "sudanophilic" by all the observers showed a fibro-elastic layer in five cases, a musculo-elastic layer in two cases and normal findings in three cases. The ten areas classified as "covered by plaques" displayed a typical atherosclerotic plaque in all cases but one. In conclusion, our data indicate that the reproducibility of gross inspective methods is low. Important discrepancies exist between findings at inspection and histologic examinations. The relevance of these findings remains to be established as far as the assessment of human atherosclerosis is concerned.

Animals↗