[The integration of nuclear medicine methods into cardiology: an operative proposal].
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Biomedical subjects
Publications and source records attributed to B Bagni.
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The term "osteogenesis imperfecta" refers to a heterogeneous group of hereditary diseases characterized by osteopenia, increased bone fragility, blue sclerae and dentinogenesis imperfecta. The abnormal synthesis of type-I collagen is responsible for the pathologic changes occurring not only in bone, but also in skin, tendons and ligaments, sclerae and teeth. The clinical and radiographic features of 5 cases (2 males and 3 females; age range: 1 month to 29 years) were analyzed. The patients were unrelated with each other. The diagnosis of the different types of osteogenesis imperfecta is as difficult as the identification of the various genotypes which are responsible for the different clinical pictures. The most characteristic radiographic pattern--which is observed in any type of the disease--consists in osteopenia associated, in most cases, with multiple fractures and deformities--e.g., micromelia, large metaphysis, archon long bones. Typically, "pop corn" calcifications are observed in both epiphysis and metaphysis of long bones. Dentinogenesis imperfecta is one of the most significant clinical patterns, and it can be the only bone abnormality. The prognosis of osteogenesis imperfecta is as varied as its genetics--i.e., the fractures discovered at birth are not necessarily a negative prognostic sign.
From 1984 to 1990 the authors reviewed the radiologic-clinical charts of 237 patients affected with multiple myeloma (MM). The series included 127 males and 110 females (mean age: 66 years) who had been classified according to Durie and Salmon clinical criteria. All the patients underwent X-rays of the skeleton, as recommended in international literature; moreover, 148 subjects underwent whole-body bone scintigraphy, and 130 bone marrow scintigraphy. A selected group of cases (18 male/female patients) were submitted to bone densitometry employing both quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA). The results follow: 1) in the first stage of the disease, a high number of patients (29.5%) exhibits no skeletal abnormalities on X-rays; the most common lesion locations include the spine (49%), skull (35%), pelvis (34%), ribs (33%), humeri (22%), femora (13%) and mandible (10%); 2) the most frequent pattern is osteolysis, as a characteristic "punched-out" multiple lesion; the second most frequent lesion is osteopenia (43%), especially in the spine; pathologic fractures are common (54%) in the ribs, vertebral bodies, limbs; typical associations of features and sites are seen on X-ray images, which sometime make diagnosis easier; 3) whole-body scintigraphy, revealing aspecific uptake only in the presence of pathological fractures, is not recommended in the first staging of the disease, but is considered as a valuable technique in the follow-up, when the patients become symptomatic; 4) bone marrow scintigraphy, especially in the "marrow expansion" pattern, might be considered as an attempt made by the body to recover the central space which was destroyed by myelomatous involvement. The prognostic value of this technique is still to be assessed; 5) bone densitometry, by confirming the grade of osteopenia, reveals that osteoporosis is a peculiar pattern of bone disease in MM, which is not related to age only; 6) conventional radiography of the skeleton is the method of choice in the diagnosis of lytic areas of MM, and remains, as yet, irreplaceable. The other diagnostic techniques--i.e., CT and MRI--can be used to evaluate the extent of bone and soft tissue involvement, in the cases with questionable diagnosis, and to assess the degree of marrow involvement.
The aim of this study was to assess the changes in atrial natriuretic peptide (ANP) levels before and after menopause and to test whether they depend on age or are an integral part of the hormonal changes in menopause. We measured plasma ANP, plasma renin activity (PRA), plasma aldosterone, serum estradiol-17 beta and progesterone concentrations in 103 normotensive women, either in premenopause (n = 35; mean age: 24 years), in physiological menopause (n = 34; mean age: 43 years) or surgically induced menopause (n = 34; mean age: 55 years). The last two groups were matched for duration of menopause and were comparable in their estrogen and progesterone status. PRA and plasma aldosterone concentrations decreased in postmenopausal women, whereas systolic blood pressure and ANP increased. These results were not confirmed after adjustment for age by covariance analysis. In all of the groups, plasma ANP concentrations were not significantly correlated with systolic or diastolic blood pressure, nor with plasma aldosterone, estrogen and progesterone concentrations. These correlations were not improved by correction for age. Plasma ANP concentrations were consistently correlated with age. These data suggest that the increase in plasma ANP levels found in postmenopausal women is related with age and that ANP does not play a direct role in the physiological hormonal changes of menopause.
Atrial natriuretic peptide (ANP), plasma renin activity (PRA), plasma aldosterone and urinary fractional excretion of sodium (%FENa) were measured in 22 athletes before and after 1 h running. After exercise the hormones increased significantly, while %FENa decreased. In fact, the percent PRA increases resulted higher than the percent ANP increases with a significant inverse correlation. It is concluded that hemodynamic changes during strenuous and prolonged physical exercise lead to the inhibition of the natriuretic properties of ANP by stimulating the renin-angiotensin-aldosterone system, although a feedback mechanism of modulation between ANP and PRA seems to occur.
Calcitonin gene-related peptide (CGRP) is known to exert potent cardiovascular effects and is presumed to participate in the neural control of circulation and blood flow. It has been assayed in many physiological and disease conditions, yet virtually nothing is known of the normal fluctuations in its circulating levels. We have studied the variability throughout a 24-h period of plasma concentrations of CGRP in eight recumbent healthy volunteers (four men and four women, 25-37 yr old), after careful standardization of their daily diet and routine schedules. A correlation with the circadian rhythms of blood pressure (BP), heart rate (HR), and plasma aldosterone (PA), PRA, plasma cortisol (PC), and atrial natriuretic peptide (ANP) was also made. Plasma CGRP concentrations ranged from a mean peak value of 18.1 +/- 1.5 pmol/L to a mean lowest value of 11.7 +/- 0.4 pmol/L (P less than 0.05). The mean circadian acrophase of CGRP (calculated by cosinor analysis to occur at 2314 h) anticipated the corresponding acrophases of the other hormones (0122, 0528, 0809, and 0840 h for ANP, PRA, PA, and PC, respectively). Instead, BP and HR rhythms seemed to be antiphasic with the ANP rhythm (calculated acrophases occurred at 1356, 1339, and 1314 h for systolic BP, diastolic BP, and HR, respectively). Our data demonstrate that, like many other hormones, CGRP circulates in plasma with a circadian rhythm. There seems to be a temporal sequence starting with the nocturnal rise in plasma CGRP concentrations and progressing with the ensuing elevations of ANP, PRA, PA, and PC, whereas BP and HR are kept to their lowest values. These findings are in favor of a physiological role of CGRP in the complex regulation of BP homeostasis.
We demonstrated in previous works that the circadian rhythms of blood pressure (BP) and atrial natriuretic peptide (ANP) are antiphasic in normal subjects and in essential hypertension. The aim of the present study was to assess the circadian rhythms of BP and ANP in 20 patients with stable congestive heart failure (CHF), divided into two groups of 10 according to their New York Heart Association functional class. A matched control group of 10 normal volunteers was also studied. Noninvasive BP monitoring at 15-min intervals was performed for 24 h. Peripheral blood samples were also obtained at 4-h intervals starting from 08:00 h. The mean (+/- SEM) circadian mesors of ANP plasma levels were 13.4 +/- 1.7 pmol/L in the control group, 28.6 +/- 2.4 pmol/L in the group of 10 patients in class II, and 81.5 +/- 12 pmol/L in the group of 10 patients in class III-IV. In normal subjects, plasma ANP concentration was highest at 04:00 h (21.5 +/- 2.7 pmol/L) and lowest at 16:00 h (8.8 +/- 2.4 pmol/L; p less than 0.01). Both groups of patients with CHF showed no significant circadian change in the plasma levels of ANP and also a significantly blunted circadian rhythm of BP. Cosinor analysis confirmed the loss of the circadian rhythms of ANP and BP in CHF patients. Our findings support the existence of a causal relationship between the circadian rhythms of ANP and BP.
The normal ranges and mathematical equations of bone mineral content (BMC), normalized to radial width (BMC/W) vs. age at the distal radius, were obtained by single photon absorptiometry (SPA), and compared in two different normal populations, one of postmenopausal females and the other of control males. The female population included 1359 postmenopausal women, aged 35 to 75 years; normal control males were 162, of the same age. The results obtained in the two groups of patients show a statistically significant (p less than 0.001) correlation between age and BMC/W, expressed in a polinomial third-degree regression. The slope of the regression curves is quite different between males and females: the mean decrement, evaluated from regression polinomial fits, results 0.5% per year for normal females, and 0.3% per year for normal males. The maximum decrement (1% per year) is observed at the mean age of 51 years, which is the average age of peri-menopausal women in our province (Ferrara). The authors believe SPA to be a simple and reliable technique in measuring peripheral bone loss rate. SPA may be useful in the diagnosis and treatment of postmenopausal women, but is not recommended in the short-term follow-up of osteoporosis.
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Twelve patients affected by idiopathic osteonecrosis of the femoral head underwent X-ray, triphasic bone scintigraphic (TBS) and CT tests on the femoral head on both sides. TBS revealed arterial hypoperfusion and an area of hypocaptation in the caput femoris in 3 coxofemoral joints which were radiologically "negative" (and of which one was also CT negative); these are scintigraphical signs which are typical of aseptic necrosis. In line with published data, TBS was found to be a more sensitive test in comparison with traditional X-ray techniques and CT, and in the early stages of disease it is more specific in recognising aseptic necrosis of the femoral head. Lastly, it is underlined that magnetic resonance is currently considered to be most sensitive (88%) and most specific (100%) imaging technique in the diagnosis of osteonecrosis of the femoral head.
We studied the response of atrial natriuretic peptide to the hemodynamic and renin-aldosterone variations occurring in four patients who developed cardiac tamponade, either occurring in idiopathic fashion in one or secondary to metastatic involvement of the pericardium in three. Right atrial pressure, heart rate and arterial blood pressure were monitored and serial blood samples were taken before and over three hours after pericardiocentesis. During cardiac tamponade, normal levels of atrial natriuretic peptide (mean +/- SEM: 54 +/- 7.4 pg/ml) were observed in the plasma despite increased right atrial pressure (23 +/- 3.8 cm H2O) and heart rates (98 +/- 4.4). Removal of pericardial fluid (540 to 1160 ml) was associated at first with a 200% increase in plasma concentrations of atrial natriuretic peptide (108 +/- 8.8 pg/ml; P less than 0.001), then with a gradual decline toward normal levels, simultaneous with the normalization of right atrial pressure and heart rate. Activity of renin and concentrations of aldosterone in the plasma were increased during tamponade and returned gradually to normal after pericardiocentesis (3.8 +/- 0.9 to 1.2 +/- 0.3 ng/ml/h and 20 +/- 4.2 to 9 +/- 3.2 ng/dl, respectively; P less than 0.01). These data confirm that atrial strain, not intracavitary pressure in itself nor heart rate, is the main determinant of the acute release of atrial natriuretic peptide, which is associated with a suppressing effect on the renin-aldosterone system. In addition, our data indicate that secretion of atrial natriuretic peptide during cardiac tamponade is not stimulated by secondary hyperaldosteronism.
The occurrence and extent of a circadian rhythm in the circulating concentrations of atrial natriuretic peptide (ANP) are still matters of controversy. Only a few data are available in humans relating the time structure of plasma ANP levels with the circadian patterns of other hormones and cardiovascular variables. In a group of hospitalized normal volunteers (six men and four women, 16-76 years old), and in a group of hospitalized hypertensives (seven men and three women, 18-76 years old), we investigated the circadian variability of ANP and its temporal relationship with the circadian rhythms of blood pressure (BP) and heart rate (HR), and plasma renin activity (PRA), plasma aldosterone (PA) and plasma cortisol (PC) levels, by using a chronobiological inferential statistic method. At the end of a synchronizing period of 1 week (the diet and daily schedule were standardized), the subjects underwent automatic BP and HR monitoring, and blood sampling for 24 h. A statistically significant mean circadian rhythm was demonstrated for ANP, BP, HR, PRA, PA and PC in both normal and hypertensive subjects. The mean circadian acrophase of ANP (calculated to occur at around 04.00 h) anticipated the corresponding acrophases of the other hormones; BP and HR rhythms appeared to be in antiphase with ANP rhythm, i.e. the peak of BP and HR rhythms more or less coincided with the trough in ANP rhythm. A significant increase in the daily levels (assessed by the circadian mesor) of ANP was present in hypertensive subjects when compared with normal controls. In essential hypertension the circadian rhythm of ANP was set at higher circulating levels, but otherwise it was similar to the circadian rhythm found in normals. ANP mesors correlated significantly with renin and aldosterone mesors in normal subjects but not in hypertensive patients. ANP appears to anticipate awakening in its circadian periodic rise. On the basis of the considerable acrophase asynchronism, it seems possible to exclude any causal relations between the periodic changes of ANP and the rhythmic fluctuations of the other hormones that we studied. In contrast, important relations may be hypothesized between ANP levels and BP and HR values, on the basis of their antiphase rhythms.
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A relationship between plasma levels of FFA and incidence of hormone-dependent breast cancer has been suggested. This observation has drawn our attention to possible complementary actions of ovarian steroids on circulating FFA levels. Measurements taken in normal women during the menstrual cycle and in ovariectomized women with and without estrogen replacement therapy demonstrate that 1) levels of FFA present in serum are lower during the luteal phase than during the follicular phase; 2) levels of FFA are significantly higher after ovariectomy; and 3) these are again reduced by substitutive estrogen therapy.
Bone lesions are the main sign of neoplastic proliferation of multiple myeloma (MM), a disseminated malignant disease which originates in, invades and replaces normal bone marrow. The most characteristic radiographic pattern is a focal lytic lesion, well-defined or "punched-out", generally with no surrounding bone reaction. The association is confirmed between MM and osteoporosis, as reduced bone density (osteopenia) and pathologic fractures (ribs, spine). This paper is aimed at evaluating the importance of osteopenia in both diagnosis and prognosis of MM. Eighteen patients affected with MM were examined with quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DEXA) for bone densitometry in lumbar spine and proximal femur. The patients (12 males and 6 females) were classified according to Durie's clinical criteria and to the radiographic patterns suggested by Merlini. The results indicate the patients with an advanced clinical stage (III) and scintigraphic expansion of bone marrow to have low densitometric values on both QCT and DEXA. There was substantial agreement between the 2 methods, but DEXA had a higher number of false positives. Instrumental diagnostic protocol may be thus planned as follows: 1) conventional radiography; 2) bone marrow scintigraphy; 3) bone densitometry of lumbar spine, with QCT. The patient is then to be followed with conventional and/or digital radiography in symptomatic locations, and with bone scintigraphy.
Esophago-jejunal reconstruction, after total gastrectomy, is best performed by one of the following three operations: interposed jejunal loop, Roux-en-Y loop and "omega" loop with Braun anastomosis. To assess the effects of the three mentioned techniques three groups of 15 patients each were examined after total gastrectomy for I, II or III stage cancer. Four to ten months after surgery all patients underwent the following tests: a) esophago-jejunal transit with labeled solid meal; b) cholangio-scintigraphy and c) absorption test of biliary acids. A group of 10 patients, without gastrointestinal pathology, was selected for comparison. The data obtained from the comparative study, in agreement with the opinions held by many Authors and our previous research, demonstrate that the interposition of jejunal loop (Mouchet) is the reconstructive technique closest to the unoperated stomach and, for this reason, is to be preferred after total gastrectomy.
The main lesions of the skull and hand, observed in a group of hypertransfused beta-thalassaemic patients, are compared with a control group of low-transfused patients. Bony abnormalities reflect the relationship between proliferating bone marrow and bone cortex, and hypertransfusion therapy will prevent development of lesions only if established early in life. If this is done, the diploë in the skull may become normal, overgrowth of facial bone is moderate, pneumatisation of the paranasal sinuses is not completely prevented, and the "hair-brush" pattern may disappear completely. A normal appearance of the hand in adequately treated patients differentiates between prepubertal patients and adults.
We have analysed the distribution and the binding properties of the epidermal growth factor (EGF) receptor in human endometrium during the menstrual cycle to validate the proposal that steroids affect the growth rate of target cells via growth factor-related pathways. The total number of EGF receptors and their affinity for the iodinate exogenous ligand are significantly higher during the proliferative than the secretory phase; the binding kinetics appear to be hyperbolic and sigmoid during the proliferative and the secretory phase, respectively. These results suggest that endogenous sex steroids can regulate the levels and the properties of EGF receptors in vivo, and support the possibility that receptor-coupled events may play a role in estrogen-stimulated growth.