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Biomedical subjects

C L Maini

Publications and source records attributed to C L Maini.

At least 55 records · Page 3Linked to original sources
PubMed1988

A statistical study on left ventricular peak filling rate in diabetes.

The importance of non-invasive evaluation of cardiac function in diabetes is well known and radionuclide angiocardiography has become an accepted diagnostic procedure. While the pathophysiological interpretation of systolic parameters is clear, the meaning and determinants of peak filling rate (PFR) remain rather speculative. In the present study, a "pattern recognition" approach, including principal component analysis and hierarchical cluster analysis, has been adopted in order to evaluate the determinants of PFR in a series of 48 non-selected diabetic patients. The results of the study show that: PFR is inversely dependent on age which is its main determinant when systolic function is preserved; PFR is inversely dependent on combined effects of left ventricular dimensions, angina and wall motion; and the duration of diabetes in itself does not influence PFR. These results lead to the following clinically relevant conclusions: (a) It is unlikely that a young diabetic patient without anginal symptoms will have a significant PFR impairment even if the diabetes has been present for a long time. If such impairment is however present, ventricular latent dysfunction is likely to be the cause even if systolic parameters are still normal; (b) A decrease of PFR in a middle-aged diabetic patient without symptoms and with normal systolic function cannot be equated with latent ventricular dysfunction as it may represent only an age-related physiological change without special diagnostic meaning.

Adolescent↗
PubMed1987

Pulmonary involvement in progressive systemic sclerosis: a multidisciplinary approach.

In an attempt to define the early features and the natural evolution of lung involvement in progressive systemic sclerosis (PSS), we planned a multidisciplinary study of these patients using radiological, scintigraphic and functional methods. As yet we have studied 21 subjects, all affected by PSS according to the American Rheumatism Association criteria. A well-defined restrictive functional pattern was present only in 10 patients out of 21; an increased elastic recoil may be present before a significant decrease of the transfer test for carbon monoxide; an increased alveolar-capillary permeability assessed by the 99mTc-diethylene-triamine-pentacetic acid (99mTc-DTPA) clearance rate has been detected in almost all the patients (13 out of 14) in at least one lung field; no significant correlation has been found between the radiological lung involvement and the 99mTc-DTPA clearance rate. We think that these preliminary results are consistent with an alveolar and interstitial inflammation rather than with a vasculitic process.

Adult↗
PubMed1987

[Assessment of uteroplacental circulation with radioisotopes].

The authors have evaluated placental blood flow using a non-invasive radioisotopic approach, with the intravenous administration of 1 mCi 113mIn. The method is evaluated in 20 normal pregnancies, in 24 patients with intrauterine growth retardation, in 8 patients with iso-Rh-immunization and in 9 patients with gestational diabetes. In the group with intrauterine growth retardation 2 pregnancies with extensive fetal malformations were included. In one case without evident histological placental alteration the index was 3.94 at 34 weeks of gestation and 5.62 at 36 weeks of gestation. In the second one with placental infarcts the index was 3.46 at 38 weeks of gestation. Normal pregnancies showed a flow index of 5.50 +/- 1.57 (1 s.d.) units compared to the pathological pregnancies value of 2.74 +/- 0.90 (1 s.d.) units. (p less than 0.001). The conclusions drawn are: The method is very well suited to clinical evaluation of placental blood flow. The evaluation of placental blood flow cannot be directly equated with fetal development as it is not its only determinant. This method is a indirect index of placental function in small for gestational age fetuses with malformations.

Congenital Abnormalities↗
PubMed1987

[Dynamic pulmonary scintigraphy with Tc99m radioaerosol for the evaluation of the permeability of the alveolo-capillary barrier].

Pulmonary clearance of small droplet 99mTc-DTPA radioaerosol was studied in 100 patients (12 normal subjects, N; 10 asymptomatic healthy smokers, FA; 31 patients with interstitial lung diseases, IP; 47 patients with chronic obstructive lung disease, BPCO). The first seven minutes of clearance were described with the function At = Ao*exp (-K*t) and the time constant K was considered representative of the 99mTc-DTPA clearance rate and hence of the alveolar-capillary barrier permeability. Groups FA, IP and BPCO showed a significant (p less than 0.05) or a highly significant (p less than 0.01) increase in permeability when compared to group N. No correlation was found between permeability and bronchial obstruction tests. The following conclusions were drawn: --99mTc-DTPA dynamic lung scanning is an easy, non-invasive method to assess derangements of alveolar-capillary barrier permeability secondary to epithelial damage; --permeability increase is a very early effect of cigarette smoke damage to the epithelium; --other mechanisms of epithelial injury are present in diffuse lung disease; --while the clinical role of this new pathophysiological test is not yet clear, it is likely that it may become a very early marker of pulmonary epithelial damage in diffuse lung disease.

Adult↗
PubMed1986

Correlation of functional parameters derived by equilibrium radionuclide angiocardiography and left ventricular size in patients with old myocardial infarction.

A total of 131 patients with old (over 6 months) myocardial infarction (MI) and 18 normal subjects underwent equilibrium radionuclide angiocardiography at rest (rERNA). The following rERNA parameters were assessed: left ventricular ejection fraction (LVEF), peak ejection rate (PER), peak filling rate (PFR), regional wall motion and a left ventricular size index. The patients with old MI were divided into four groups (I to IV) according to increasing left ventricular (LV) size, and the behaviour of the numerical parameters (LVEF, PER, PFR) was evaluated in each group. LVEF proved to be the most sensitive numerical parameter of overall LV performance. PFR decreased significantly from group I to group III but not from group III to group IV, suggesting that for extreme degrees of left ventricular enlargement some compensatory mechanism acts to prevent a too large fall in LV compliance. The effects of the site of the previous MI on LV performance were also evaluated. Both LV size and performance were least affected by postero-inferior MI. The LVEF was, however, a better predictor of LV size than the site of the MI.

Adult↗
PubMed1986

Equilibrium radionuclide angiocardiography to select inotropic therapy in patients with left ventricular aneurysm.

Fourteen patients with postinfarctual ventricular aneurysm underwent equilibrium radionuclide angiocardiography at rest (ERNA) before and after oral digoxin administration in order to evaluate the effects of increasing myocardial contractility upon both ventricular aneurysm mechanical behaviour and global ventricular function. The ejection fraction (EF) was not significantly affected by digoxin therapy. However, digoxin induced changes in EF (delta EF) correlated inversely with changes in aneurysm size and directly with changes in the extent of the hypokinetic area. Two types of aneurysm were observed: high-compliance aneurysm the size of which increased after digoxin administration while both EF and the extent of the hypokinetic area fell, and low compliance aneurysm for which opposite changes occurred. This different behaviour of ventricular aneurysm may have important practical implications as surgery would be probably more effective than medical treatment in improving resting ventricular function in patients with high-compliance aneurysm.

Adult↗
PubMed1986

The use of digitalis in patients with chronic respiratory failure.

The effect of slow digitalization was tested by radioisotopic angiocardiography in 33 patients with stable and compensated chronic obstructive pulmonary disease (COPD); most of these had severe chronic respiratory failure (CRF). After a 10 days course of digoxin, 0.25 mg/die per os, both the left ventricular ejection fraction (LVEF) and the peak ejection rate (PER), initially slightly abnormal, improved significantly (t = -3.474, p less than 0.005; t = -2.438, p less than 0.025), while right ventricular ejection fraction (RVEF) and peak filling rate (PFR) did not. Ventricular diastolic interdependence and abnormal myocardial calcium kinetic are likely to account for PFR behaviour. Digoxin effects upon RVEF and LVEF suggest that the right ventricular systolic function is to some extent independent from the left one when blood gas derangement and abnormal thoracopulmonary mechanics are the major determinant of right ventricular afterload. The lack of significant correlation between digoxin effects on right and left ventricular function indices confirms this hypothesis. Digoxin can improve the left ventricular ejection phase indices, when these are initially abnormal, while its effect on RVEF is unpredictable.

Adult↗
PubMed1986

[Scintigraphy of pulmonary ventilation with 99mTc-DTPA radio-aerosol. I. Semiotics of the static images].

Papers on deposition pattern analyses of radio-aerosol lung scans are few and not easy to interpret as there is a general lack of technical standardization and the number of patients studied is not large. Moreover these reports have been generally obtained with non-hydrosoluble radioaerosols. In the present study 43 patients underwent conventional pulmonary function testing and lung scanning using small droplet (equal or less than 2 microns) polydisperse 99mTc-DTPA radioaerosol produced with the "Settling Bag System"--Medi 400 (Sorin). The scans were analysed by two methods: a semiquantitative method proposed by Taplin (SQT); an original simpler semiquantitative method (SQM). Correlations of SQT and SQM with FEV1 and MEF75 resulted highly significant (p less than 0,001). SQM proved to be superior to SQT as far as reproducibility is concerned. The following conclusions can be drawn: small particle 99mTc-DTPA aerosol can be easily and cheaply produced by a commercial device; such a radioaerosol is well suited for the evaluation of small and large airways patency, as reflected by MEF75 and FEV1 respectively, with a diagnostic yield comparable to non-hydrosoluble radioaerosols; the original semiquantitative description of the deposition patterns proposed and validated in this study is quite easy to implement and it yields a high correlation with pulmonary function tests; moreover such an approach does not require digital data processing; the sensitivity of 99mTc-DTPA for the diagnosis of bronchial obstruction is very high and superior to routine pulmonary function tests; in addition the ventilation scan allows the topographical localization of the obstructions themselves.

Adult↗
PubMed1986

Right ventricular wall motion and performance in stabilized chronic respiratory failure evaluated by equilibrium radionuclide angiocardiography.

Equilibrium radionuclide angiocardiography (ERNA) was performed at rest in 30 patients with chronic respiratory failure (CRF) in order to evaluate right ventricular performance and wall motion. The usual indices of left ventricular performance were also recorded and correlated with right ventricular parameters. Only CRF patients without clinical, electrocardiographic or echocardiographic criteria suggestive of congenital, valvular, hypertensive or ischemic heart disease were studied. A RV dyskinesis was detected in 5 of the 30 patients, occurring however only in stage II-III CRF, as if a longstanding RV pressure overload were necessary for a RV dyskinesis to develop. No significant differences were found between patients with and without RV dyskinesis for all the functional ERNA parameters (i.e. LVEF, RVEF, PER, PFR). On the other hand, a significant correlation between the stage of the CRF and RVEF was observed.

Cardiac Output↗
PubMed1986

The effects of chronic hypoxia on left ventricular peak filling rate evaluated by equilibrium radionuclide angiocardiography.

Left ventricular peak filling rate (PFR) was measured by equilibrium radionuclide angiocardiography (ERNA) in 15 patients with Stage II stabilized chronic respiratory failure (CRF) without evidence of coexisting heart diseases and in 18 patients with coronary artery disease (CAD) without myocardial infarction. The study was designed to assess the effects of severe hypoxia and of ischaemia on the calcium-dependent early diastolic filling. PFR was found to be impaired in both groups of patients (mean = 1.72 EDVs-1 and S.E.M. = 0.07 in CAD; mean = 2.35 EDVs-1 and S.E.M. = 0.14 in CRF) but significantly less (p less than 0.001) in CRF patients while the left ventricular ejection fraction (LVEF) values were not significantly different between the two groups (mean = 60.0% and S.E.M. = 1.4 in CAD; mean = 62.0% and S.E.M. = 1.6 in CRF). As PFR is known to be a sensitive index of left ventricular performance the results obtained in this human model are consistent with findings obtained in animal models suggesting that hypoxia is less efficient than ischaemia in depressing left ventricular function.

Adult↗
PubMed1986

[Possibility of using 131I-meta-iodobenzylguanidine in the diagnosis of neuroendocrine tumors differing from pheochromocytomas].

The results obtained using 131I-MIBG to diagnose different neuroendocrine tumors in 17 patients are discussed. In 8 of the neuroblastomas studied the examination gave a wide spectrum of scintigraphic results according to the various stages of evolution of the tumors, thus supplying additional useful information for metabolic treatment. Contradictory data were obtained in 5 cases of medullary cancer of the thyroid. The overall results were unexpectedly negative for 2 carcinoid tumors and, as expected, negative for 2 ganglioneuromas. These data confirm that 131I-MIBG is a non invasive, reliable and easy-to-perform technique which is no longer limited to the diagnosis of pheochromocytomas, but can also be used for the diagnosis of other tumors derived from neural crest cells.

3-Iodobenzylguanidine↗
PubMed1985

A simple method of predicting left ventricular function in stabilized chronic respiratory failure.

A simple method of assessing left ventricular function in stabilized chronic respiratory failure (CRF) is proposed. 21 patients with CRF were ranked according to the prediction of left ventricular function derived from eight elementary clinical criteria including standard chest X-ray and conventional basal electrocardiography. Equilibrium radionuclide angiocardiography was performed at rest (rERNA) for the evaluation of left ventricular systolic function (ejection fraction, LVEF; peak ejection rate) and diastolic function (peak filling rate). Right ventricular ejection fraction (RVEF) was also measured. The clinical evaluation of the left ventricular function showed a high correlation with rERNA data (p less than 0.01 by Spearman's rank test). No correlation was found between rERNA parameters and PaO2 and between RVEF and LVEF. The clinical criteria proposed can thus predict left ventricular function in stabilized CRF with a high degree of confidence.

Angiocardiography↗
PubMed1985

Non-invasive radioisotopic evaluation of placental blood flow.

The authors have evaluated placental blood flow using a non-invasive radioisotopic approach. The procedure involves the intravenous administration of 113mIn and the technique is a modified version of a previously reported method for a non-diffusive tracer kinetics analysis. The method is presented in detail and its performance is evaluated in 17 normal and 32 pathologic pregnancies (19 intrauterine growth retarded patients; 7 patients with iso-Rh immunization; 5 patients with gestational diabetes, and 1 pregnancy with extensive fetal malformation which was not included in any group). The normal pregnancies showed a flow index of 5.34 +/- 1.64 (1 SD) units compared to the pathological pregnancies value of 2.73 +/- 0.73 (1 SD) units (p less than 0.001). The conclusions drawn are: (1) the method is very well suited to clinical evaluation of placental blood flow; (2) the evaluation of placental blood flow cannot be directly equated with fetal development as it is not its only determinant, and (3) no other independent test to evaluate the radioisotopic study in terms of accuracy exists.

Adult↗
PubMed1985

99mTc-DTPA clearance in bullous emphysema.

The degree of permeability of the alveolar-capillary barrier to low molecular weight solutes has been supposed to depend upon the radius of the epithelial pores. The bullous emphysema is a natural model in which this radius may increase because of the high tension in the bulla. Accordingly, the 99mTc-DTPA clearance may be expected to be faster than normal in lung fields including bullae. Results of the present study in which 99mTc-DTPA clearance was measured in six patients with bullous emphysema, seem to confirm this hypothesis at least to some extent. In fact, either increased or normal 99mTc-DTPA clearances were found over the lung fields including bullae communicating with the bronchial tree. Differences in both the size and the inner tension of the bullae as well as in the anatomical and functional conditions of the surrounding parenchyma are likely to account for such varying behaviour.

Capillary Permeability↗
PubMed1985

Left ventricular diastolic performance at rest in patients with angina and normal systolic function--assessment by equilibrium radionuclide angiography.

The aim of the study was to correlate diastolic function, as evaluated by peak filling rate (PFR) and relative time (TPFR), with the severity of ischemic heart disease, as evaluated by exercise electrocardiography. Accordingly, 83 ischemic patients with effort angina, but normal ejection function at rest and normal left ventricular size, were studied by equilibrium radionuclide angiocardiography within two weeks from the exercise ECG. Diastolic dysfunction, as determined from PFR and, to a lesser extent, from TPFR, is common in patients with ischemic heart disease and normal systolic function. The prevalence and severity of such dysfunction is related more to the severity of the ischemia, as evaluated by the exercise ECG, than to the presence of an old myocardial infarction. Such findings are consistent with the hypothesis that PFR reflects mainly the early diastolic active uncoupling process.

Adult↗
PubMed1984

Scintigraphic localization of a disseminated malignant pheochromocytoma with the use of 131I-meta-iodobenzylguanidine.

Preliminary clinical studies with 131I-meta-iodobenzylguanidine, a newly synthesized radiopharmaceutical and guanethidine analog capable of imaging the adrenal medulla, have led to the identification of a case of disseminated malignant pheochromocytoma with the localization of brain and bone metastases. The result is of particular interest as the symptomatology in this case appeared rather equivocal and various investigations had led to a completely different diagnosis. This new scintigraphic technique has proved to be safe, specific and noninvasive, and it may have a clinical application as a complementary or alternative technique to conventional diagnostic tests.

3-Iodobenzylguanidine↗
PubMed1983

A practical approach to the hepatobiliary kinetics of 99mTc-HIDA. Clinical validation of the method and a preliminary report on its use for parametric imaging.

99mTc-diethyl-HIDA cholescintigraphy was performed on 24 patients with histologically proven liver disease and on 10 normal adult subjects. Liver mass transport of HIDA was interpreted with the aid of a probabilistic model, assuming that the tracer particles undergo mixed random walks with drifts. The radiohepatograms were thus fitted with a gamma-variate function and the fitting parameters were evaluated as estimates of the severity of the disease. These parameters, together with the transit times, were also used to generate parametric images of liver function. The advantages of this approach are discussed and the following conclusions are drawn: (1) The gamma-fit is highly satisfactory with any type of experimental curve (0.98 less than r less than 1). (2) The parameters derived from the gamma-fit make it possible to objectively assess the extent of liver functional impairment. (3) Parametric imaging of the liver mass transport of HIDA is easily implemented, but still more experience is needed to assess its impact on patient care.

Bile Ducts↗