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Biomedical subjects

M Baroni

Publications and source records attributed to M Baroni.

At least 19 recordsLinked to original sources
PubMed1996

Ambulatory follow-up of aortic dissection: comparison between computed tomography and biplane transesophageal echocardiography.

UNLABELLED: Aim of the study was to assess the relative usefulness of transesophageal echocardiography (TEE) and X-ray computed tomography (CT) in the follow-up of patients who survived an aortic dissection. MATERIALS AND METHODS: We evaluated 44 patients (age = 57 +/- 12 years) with treated aortic dissection: 14 had a De Bakey type I, 20 a type II and 1 patient a type III dissection treated surgically: 1 patient had a type I, 1 a type II and 7 a type III dissection treated medically. All entered an outpatient follow-up program with serial evaluations at 1, 6 and 12 months after initial diagnosis by dual noninvasive imaging protocol. A contrast-enhanced CT scan and a TEE with biplane probe were performed on the same day and in random order. RESULTS: A total of 252 evaluations with both CT and TEE were considered. A completely normal study was found in 45 TEE and 48 CT evaluations. The following abnormal findings could be documented by one or both techniques: thrombus in the false lumen (TEE: n = 48; CT: n = 45 evaluations); intimal flap (TEE and CT: n = 68); aortic dilatation (TEE and CT: n = 15); pericardial effusion (TEE and CT: n = 3); aortic pseudoaneurysm (TEE: n = 2; CT: n = 3); isthmic coarctation (TEE and CT: n = 1). Regarding the presence or absence of these abnormalities, which are within the diagnostic domain of both imaging techniques, the results were fully concordant in 245 studies, and discordant in 7, with an overall agreement of 97%. In addition, some abnormal findings could be detected by TEE only: aortic insufficiency (n = 36); intimal tear (n = 25); spontaneous echocontrast effect in the false lumen (n = 39 evaluations). Other abnormal findings could be detected by CT only: a pleural effusion in 4, a truncus anonymous dissection in 1, a pseudoaneurysm due to suture dehiscence of the distal anastomosis of the ascending aorta in 1 evaluation (which yielded ambiguous results by TEE, with turbulent flow departing from the graft). CONCLUSION: Both CT and TEE are atraumatic, safe and accurate techniques for serial follow-up imaging of patients treated for aortic dissection. Information provided by CT is largely redundant, rather than additive, to that provided by TEE. The latter should be probably preferred for shorter imaging time, accuracy and convenience, although CT might still play a role in selected cases of ambiguous TEE results.

Adult↗
PubMed1996

Education for the nursing of children and their families: standards and guidelines for prelicensure and early professional education.

To strengthen the preparation of nurses for care of children and families, standards and guidelines for prelicensure and early professional education were developed by a working group with broad-based input. Assumptions, theory, practice, and research underlying the standards and guidelines concerned the nature of health care, knowledge, teaching, learning, and evaluation. The 11 standards are presented and guidelines are illustrated. How they are implemented will depend on local resources and philosophies. Continued dialogue among nurse educators is needed to refine and develop the standards and guidelines.

Humans↗
PubMed1996

Functional identification of rat atypical beta-adrenoceptors by the first beta 3-selective antagonists, aryloxypropanolaminotetralins.

1. We have assessed the relative abilities of compounds belonging to the new aryloxypropanolaminotetralin (APAT) class and of the reference beta-adrenoceptor-blocking agent, alprenolol, to antagonize functional responses in vitro and in vivo involving atypical (beta 3) or conventional (beta 1 and beta 2) beta-adrenoceptors. 2. The range of pA2 values for three representative APATs against inhibition of spontaneous motility in the rat isolated colon by the selective beta 3-adrenoceptor agonist, SR 58611A (8.1-8.8), was well above similarly calculated values for non-competitive antagonism of guinea-pig trachea relaxation by salbutamol (beta 2, 6.5-6.9) and the atrial chronotropic response by isoprenaline (beta 1, 6.7-7.3). Alprenolol, however, was substantially more potent in antagonizing atrial (pA2, 8.2) and tracheal (pA2, 8.9) responses than SR 58611A mediated inhibition of colonic motility (pA2, 6.8). 3. Several APAT isomers with different configurations at the chiral carbons, when tested on isolated organs, presented stringent stereochemical requirements for beta 3-selectivity, including high antagonist potency-ratios between active and inactive enantiomers. 4. In vivo, the inhibition of colonic motility and the thermogenic response of brown adipose tissue elicited in rats by the selective beta 3-adrenoceptor agonists SR 58611A and BRL 37344 respectively were substantially diminished by the representative APAT, SR 59230A, at oral doses (< or = 5 mg kg-1) well below those half maximally effective (ID50) for preventing beta 1-(isoprenaline tachycardia > or = 80 mg kg-1) or beta 2-(salbutamol bronchodilatation, 44 mg kg-1) mediated responses. Alprenolol, as expected, was a less potent and nonselective antagonist of the putative beta 3-responses. 5. These findings support APATs as the first potent, orally effective selective antagonists at beta 3-adrenoceptors, and provide final unambiguous evidence that beta 3-adrenoceptors underlie inhibition of colonic motility and brown adipose tissue thermogenesis in rats.

Adipose Tissue↗
PubMed1996

Mechanisms of regional ischaemic changes during dipyridamole echocardiography in patients with severe aortic valve stenosis and normal coronary arteries.

OBJECTIVE: Vasodilator stress echocardiography can cause myocardial ischaemia in patients with severe aortic valve stenosis and angiographically normal coronary arteries. The aim of the study was to determine the mechanism of ischaemia in this clinical model. METHODS: The study group comprised patients with severe aortic valve stenosis and normal coronary arteries: 25 patients (17 males, eight females; age 63 (SD 11) years) underwent a high dose (up to 0.84 mg/kg over 10 min) dipyridamole echocardiography test both before (2-4 d) and after (10-15 d) aortic valve replacement. Mean aortic pressure gradient was 96 (15) mm Hg, with a left ventricular mass index of 228 (49) g/m2. The dipyridamole echocardiography test was well tolerated and interpretable in all patients. RESULTS: Dipyridamole infusion induced chest pain in seven patients before and in no patient after surgery (28 v 0%, P < 0.01), ST segment depression in 12 patients before and two after surgery (48 v 8%, P < 0.01), and a transient regional dyssynergy in 10 patients before and two after surgery (40 v 8%, P < 0.01). In the preoperative evaluation, patients with an echocardiographically positive dipyridamole echocardiography test were comparable with patients with negative test as far as left ventricular mass index [240 (67) v 230 (64) g/m2, NS] and mean aortic pressure gradient [95 (22) v 92 (21) mm Hg, NS] were concerned. When compared to the preoperative assessment, the resting echo assessment in the postoperative evaluation showed unchanged values of left ventricular mass index [pre 228 (49) g/m2 v post 220 (36) g/m2, NS], but markedly decreased values of mean aortic gradient [pre 95 (15) mm Hg v post 22 (5) mm Hg, P < 0.01] and left ventricular wall stress index [pre 134 (30) g/cm2 v post 89 (19) g/cm2]. CONCLUSIONS: Dipyridamole echocardiography is a suitable clinical technique for assessing the ischaemic vulnerability of the left ventricle in severe aortic valve stenosis with angiographically normal coronary arteries. The frequent disappearance of the ischaemic response early after aortic valve replacement suggests that haemodynamic factors such as compressive diastolic wall stress or afterload reduction are important components of myocardial ischaemic vulnerability under these circumstances.

Adult↗
PubMed1996

Multimodal treatment to prevent the late whiplash syndrome.

In order to assess the long-term efficacy of a multi-modal rehabilitation approach on whiplash injury, 60 patients were recruited within two months after neck injury. They were randomly allocated either to an experimental multimodal treatment (A) consisting of postural training, manual technique and psychological support or to a control treatment (B), using physical agents only, such as electrical and sonic modalities. Pain level, range of movement, self-rating scale of treatment efficacy and return-to-work delay were evaluated before and at the end of treatment, and later, 30 and 180 days after randomisation. The benefit obtained with treatment "A" was greater and longer lasting than that experienced using "B", despite the fact that the same benefit was obtained in joint mobility in the two groups. Patients undergoing the experimental treatment returned to their usual occupations sooner than the controls. The results seem to confirm the hypothesis of a multifactorial involvement as a possible mechanism for the late whiplash syndrome.

Adolescent↗
PubMed1995

Regional myocardial performance of non-ischaemic zones remote from anterior wall left ventricular aneurysm. Effects of aneurysmectomy.

The aim of this work was to investigate the effects of resecting a post-infarction left ventricular anterior aneurysm on the kinetics of the non-ischaemic inferior wall, remote from the healed lesion. Thirteen patients, with an anterior post-infarction aneurysm and a normal right coronary artery who underwent aneurysmectomy with endoventricular circular patch plasty reconstruction, had a complete haemodynamic study before and shortly after surgery. The shape of the left ventricle was quantitatively analysed by calculating the regional curvature at 90 points of the angiographic outlines (30 degrees right anterior oblique projection). Segmental wall motion was studied by means of the centreline method and by constructing pressure-length loops from the endocardial movement of 18 chords intersecting the left ventricular inferior contour and by simultaneously tracing the high-fidelity left ventricular pressure. Analysis of pressure-length regional loops showed a complex pattern of abnormal contraction and relaxation in the non-ischaemic inferior regions at baseline; after surgery such abnormalities decreased significantly and tended to revert to normal in many cases. Left ventricular shape in the inferior region was abnormal in 10/13 patients in that there was negative curvature at the interface between the aneurysm and the inferior wall that was corrected to positive after surgery. Regional inferior wall motion and global ejection fraction significantly improved after surgery in these 10 patients. The three patients whose global ejection fraction did not improve showed no inferior negative curvature pre-operatively, nor did they show an increase in inferior wall motion. The results indicate that regional function and shape in inferior, non-ischaemic regions, remote from an anterior aneurysm, are abnormal but potentially correctible if the abnormal mechanical burden imposed on the wall is relieved.

Aged↗
PubMed1994

Elliptic Fourier approximation with application to left ventricular contour analysis.

A computer program for the quantitative analysis of left ventricular wall motion, in standard angiography or echography, was developed based on the center-line model. In order to resolve the uncertainties of the previous implementations, the elliptic Fourier approximation was tested on a large set of left ventricular contour pairs, in various pathological conditions. Fitting a function to the center-line (in the middle of end diastolic and end systolic contours) makes it possible to perform multiple tasks at the same time, in an analytical way and without the need of arbitrary parameters, such as search windows. In doing so, the flexibility and accuracy of this method was demonstrated, more in general, for filtering, interpolation and differentiation of noisy 2D or 3D data. A comparison with standard B-spline was carried out, for both open and closed curves, with sparse or equispaced points. The resulting approximation errors were twice as high as those of the elliptic Fourier decomposition, still preserving smooth direction and curvature. Though already described, this methodology deserves more widespread application.

Algorithms↗
PubMed1994

Immunochemical versus guaiac occult blood stool tests: results of a community-based screening program.

This study was designed to investigate two guaiac-based and one immunochemical faecal occult blood test in a community screening program. A total of 39,000 test kits consisting of Hemoccult II, Hemoccult Sensa and HemeSelect were distributed and of these 8933 (23%) were returned for testing. Follow-up contact with 1165 individuals who tested positive on at least one of the nine test slides was successful in 1076 cases (92.4%). Physician verification in 631 individuals revealed 25 patients (4%) diagnosed with colorectal cancer and 145 (23%) with polyps, of which 120 (82.7%) were adenomatous. The percentage of smaller adenomatous polyps detected relative to the percentage of large polyps (> 1 cm) was: Hemoccult II 31% versus 60%, Hemoccult Sensa 73% versus 80% and HemeSelect 34% versus 57%, respectively. The proportion of adenomatous polyps greater than 2 cm detected by individual tests was even more striking with Hemoccult II positive for 83%, Hemoccult Sensa for 100% and HemeSelect for 75%. Of the 25 patients diagnosed with cancer, 17 (68%) were diagnosed with early-stage disease. A statistically significant trend (P < 0.001) was observed with positive predictive values ranging from 3.3% for individuals with only one positive test to one approaching 40% for individuals with 7 or more positive tests. In this study, the most sensitive predictor of colorectal cancer was found to be the combination of Hemoccult II/HemeSelect. While there was no increase in the positive predicted value for adenomatous polyps < or = 1 cm, there was a direct linear increase for adenomatous polyps > 1 cm.

Adenomatous Polyps↗
PubMed1994

Left ventricular shape changes induced by aneurysmectomy with endoventricular circular patch plasty reconstruction.

Aneurysmectomy with left ventricular (LV) patch plasty reconstruction for anterior post-infarction LV aneurysm is usually followed by favourable haemodynamic results. The aim of this work was to describe the changes in LV shape induced by the intervention and to correlate them to the pre-operative data and to the surgical results. Twenty-two patients submitted to aneurysmectomy with this technique underwent a haemodynamic study before and 10-15 days after the intervention. Segmental wall motion was studied by the centreline method. LV shape was analysed by calculating the regional curvature of angiographic outlines (RAO 30 degrees projection). Results showed an improvement in LV pump function in 17 patients, which appeared mainly due to increased systolic shortening of the inferior wall. The intervention-induced modifications of LV geometry were characterized by: (1) marked reduction in end-diastolic volume, (2) shift of the angiographic apex counterclockwise, towards the aortic corner, (3) disappearance of the rim with negative curvature corresponding to the infero-apical border of the aneurysm, where the inferior wall resumed a normal outward convexity. No significant difference was found between the pre-operative haemodynamic data of patients who improved after surgery and those who did not. The presence of a rim of negative curvature at the infero-apical border of the aneurysm was the only pre-operative sign with a predictive value for the surgical outcome.

Aged↗
PubMed1994

Alterations in left ventricular shape in patients with angina and single-vessel coronary disease.

BACKGROUND: Left ventricular shape alterations, apparently independent of acute ischaemia or previous myocardial infarction, have been described in patients with stable angina. Our previous observations had been made in a group of patients with multivessel coronary disease; it was therefore not possible to establish a clear-cut anatomical relationship between the location of ischaemia and the changes in left ventricular contour. The aim of this work was to extend the previous observations by analysing left ventricular shape in patients with angina and single-vessel coronary disease, in whom the potentially ischaemic region can be easily localized. METHODS: Fifty-eight patients with stable or unstable angina were retrospectively selected if they had single-vessel disease, normal regional and global function and no previous myocardial infarction: 37 had a critical stenosis (more than 75% diameter reduction) of the left anterior descending artery and 21 had a critical stenosis of the right coronary artery. Patients with left ventricular hypertrophy or any other obvious cause of myocardial dysfunction were excluded. All patients underwent haemodynamic study. Left ventricular global shape was evaluated by calculating eccentricity and circular indices; regional curvature was measured at 90 points along the angiographic contours (right anterior oblique projection) by applying a windowed Fourier analysis. Results were compared with those obtained in 16 normal subjects. RESULTS: Patients had significant diastolic alterations in left ventricular shape, which assumed a more rounded aspect than normal. Regional curvature was significantly altered at several points pertaining to the anterior, apical and inferior segments. The pattern of changes in regional curvature was about the same in the left anterior descending and right coronary artery groups, with the involvement of regions supplied by angiographically normal arteries, although the extent of alteration was greater in patients with stable, chronic angina (more than 6 months) and in patients with stenosis of the left anterior descending artery. CONCLUSIONS: Patients with angina, no previous myocardial infarction and normal systolic function had left ventricular shape abnormalities either in the potentially ischaemic or in the remote zones. The mechanism leading to these changes is still speculative.

Adult↗
PubMed1994

[Echography and integrated imaging in the diagnosis of hyperparathyroidism].

The authors report their personal experience with US, CT, biopsy and, lately, MRI, to localize enlarged parathyroid glands in primary and secondary hyperparathyroidism. December 1986 through December 1993, sixty-four primary and 55 secondary hyperparathyroidism patients were examined--119 in all. At biopsy and surgery, US sensitivity appeared to be 72%, with 0.94 positive predictive value; CT sensitivity was 80% with 0.91 positive predictive value. The two methods combined had 87% sensitivity in all. In the authors' experience, US proved to be a sensitive, accurate and cost-effective technique, as well as the best method to guide biopsy thanks to its multiplanar capabilities. Even though it requires great operator's experience, US is the method of choice in the localization of abnormal parathyroid glands. Its combination with CT increased overall sensitivity mainly in ectopic localizations and postoperative recurrences. Finally, technologic progress and increased MR sensitivity are likely to make MRI the imaging technique of choice, replacing CT, in the diagnostic protocol of hyperparathyroidism.

Adolescent↗
PubMed1994

[Percutaneous alcohol injection in hyperparathyroidism. Experience in 11 cases with an 18-month follow-up].

The authors report the results of US-guided percutaneous ethanol injection into parathyroid glands of 11 patients with primary (2) and secondary (9) hyperparathyroidism. Selection criteria for choosing ethanol treatment were the patient's refuse of surgery and high surgical risks for age or severe chronic intercurrent conditions. At 18 months' follow-up, PTH serum levels had normalized in 2 primary and 2 secondary hyperparathyroidism patients; in all the others but one, PTH levels markedly decreased--always > 50% relative to pretreatment values. Serum calcium and phosphorus levels also decreased, which was not always the case with alkaline phosphatase. After injection, the glands became progressively hyperechoic, gland volume decreased and calcifications appeared. Parenchymal flow disappeared on color-Doppler US images. This study confirms the capabilities of US-guided ethanol injection in hyperfunctioning parathyroids, even though complications may occur and the condition recur. This method is thus suggested as an effective alternative to surgery.

Adenoma↗
PubMed1993

Quantitative evaluation of left ventricular shape in anterior aneurysm.

The purpose of the study was to analyze left ventricular (LV) shape in post-infarction anterior aneurysm by utilizing quantitative analysis of wall curvature. Forty-one patients (39 men, 2 women; mean age 56 years) subjected to surgical intervention for LV aneurysm complicating an anterior myocardial infarct were retrospectively evaluated. In all patients the presence of resectable aneurysmal tissue had been confirmed by direct surgical examination. Patients with inferior myocardial infarction and patients who had undergone percutaneous transluminal coronary angioplasty (PTCA) or bypass surgery were excluded. Pre-intervention ventriculograms (RAO projection) were analyzed. LV wall excluded. Pre-intervention ventriculograms (RAO projection) were analyzed. LV wall motion was studied by applying the centerline method. Regional curvature of end-diastolic and end-systolic outlines was calculated at 90 equidistant points from aortic corner (point 1) to mitral plane (point 90). Patients with LV anterior aneurysm show a typical pattern of alterations in wall curvature, which is characterized by a shifting of the angiographic apex (the point with the greatest curvature) towards the mitral plane, and by a sharp shift of curvature values at the antero-basal and infero-apical regions, marking the borders of the sac. These hinge points closely correspond to the external limits of wall motion abnormalities. Significant correlations were found between degree of regional curvature alterations and severity of global LV dysfunction, as indicated by decrease of ejection fraction and increase of end-systolic volume. In conclusion, quantitative evaluation of LV shape by means of wall curvature analysis allows recognition of the characteristic morphologic changes of the aneurysm, i.e., wall expansion and deformation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗
PubMed1993

Electrophysiological and cognitive effects of lumbar myelography with iopamidol: comparison with diagnostic lumbar puncture.

To assess the influence of contrast medium on cortical function, we studied 20 patients undergoing lumbar myelography with iopamidol and 10 patients undergoing diagnostic lumbar puncture (controls). The examinations performed before and 6 and 24 h after myelography (or lumbar puncture) included a neuropsychological battery and an electrophysiological evaluation. In the patients cranial CT was performed thrice to assess passage of contrast medium from the cerebrospinal fluid into the brain. Neither patients nor controls had significantly different scores on neuropsychological testing after the diagnostic examinations. A transient slowing of basal EEG activity could be detected in 2 patients and 3 controls 6 h after the lumbar puncture. In 3 patients CT showed a transient increase in density of the brain. None of the parameters studied was significantly affected by myelography with iopamidol. CT findings support the hypothesis of early clearance of iopamidol from brain tissue, explaining its low neurotoxicity.

Adult↗
PubMed1993

Left ventricular remodeling in chronic aortic regurgitation.

Left ventricular (LV) shape in chronic volume overload due to aortic regurgitation is commonly described as rounder than in normal subjects. This statement derives from observations of qualitative nature or based on the measure of eccentricity index. We analyzed LV shape and function in 16 normal subjects (N) and in 24 patients with chronic pure aortic regurgitation (AR), without coronary artery disease or associated mitral regurgitation. LV cavity geometry was quantitatively evaluated from end-diastolic and end-systolic outlines obtained in 30 degrees RAO angiographic projection, by calculating: 1. the eccentricity and circularity indexes, 2. the regional curvature at 90 equidistant points using a windowed Fourier series approximation of contours, in which the number of harmonics and filter-window were locally chosen in order to minimize the reconstruction errors and to maximize the smoothness of the curve, 3. by measuring the length of the anterior and posterior hemi-perimeter of LV outlines and 4. by performing a Fourier analysis of LV contours. Neither eccentricity nor circularity indexes were adequate to differentiate shape abnormalities, whereas Fourier geometric analysis indicated abnormalities of shape in AR. Regional curvature showed that diastolic outline of AR had a greater curvature of the anterobasal, anterolateral and inferoapical regions and a lower curvature of the anteroapical one. Systolic outline showed a greater curvature of the inferoapical region and a lower curvature of the anteroapical one.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Steroid receptor enhancement by natural interferon-beta in advanced breast cancer.

In the current study we investigated the effect of two different doses of natural interferon-beta (IFN-beta) on steroid hormone receptors in 45 patients with advanced breast cancer. IFN-beta seems to regulate the receptor mechanisms, inducing in cutaneous metastases an increase of oestrogen and progesterone receptors. Moreover, using IFN-beta and tamoxifen as a combined therapy in 23 receptor-positive patients, no negative interference of the two drugs was observed and no relevant side-effects due to the treatment were noticed. The modulation of steroid receptor content by IFN-beta in advanced breast cancer might represent an interesting way to ameliorate the clinical responsiveness to anti-oestrogens.

Aged↗