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Biomedical subjects

M Papa

Publications and source records attributed to M Papa.

At least 55 records · Page 3Linked to original sources

Estrogen induces c-fos expression specifically in the luminal and glandular epithelia of adult rat uterus.

It was previously shown that injection of 17 beta-estradiol into adult ovariectomized rats induces a rapid and transient increase of c-fos gene transcription in the uterus. Immunohistochemical analysis now shows that estrogen activates c-fos specifically in the luminal and glandular epithelial cells of the endometrium, which are the only uterine cells responding to the hormone with DNA synthesis and cell proliferation, and not in estrogen receptor positive stromal and myometrial cells. This finding suggests that c-fos is involved in the mechanism of estrogen regulation of uterine epithelial cell proliferation and, furthermore, that the c-fos activation by estrogen is cell type dependent.

Animals↗

[Right atrial isomerism with pulmonary atresia: the angiocardiographic characteristics and pulmonary circulatory patterns].

The patterns of pulmonary circulation were assessed by angiography in a series of 24 patients with right atrial isomerism (asplenia syndrome) and pulmonary atresia. Mean age at catheterization was 21.5 days (range 1 day-11 months). The pulmonary arteries were confluent in 22 cases (91.7%). Eighteen patients (75%) had ductus-dependent pulmonary circulation in presence of confluent pulmonary arteries, similar to cases of pulmonary atresia combined with complex congenital heart disease. The ductus appeared in continuity with the aortic arch, shaping an acute angle with the descending aorta, as in cases of pulmonary atresia with ventricular septal defect. A bilateral ductus was present in 5 cases (20.8%), 3 with confluent and 2 with nonconfluent pulmonary arteries. One patient presented multiple systemic collaterals to the lungs. All the other patients had normal arborization of the pulmonary arteries. Seven patients presented an obstructed total anomalous pulmonary venous connection: 4 in inferior vena cava and 3 in superior vena cava. These anatomical observations provide useful information for the surgical palliation of these anomalies and, probably, warrant pre-operative angiographic evaluation in all the patients with right atrial isomerism.

Angiocardiography↗

Ventricular septal defect in Down syndrome. Anatomic types and associated malformations.

Ventricular septal defect is a common cardiac anomaly in Down syndrome. To detect the prevalence of anatomic types and associated cardiac malformations we analyzed the echocardiographic and angiocardiographic findings of 73 children with ventricular septal defect and Down syndrome. We compared these results with those obtained in 303 patients with ventricular septal defect without Down syndrome. The prevalence of inlet ventricular septal defect was significantly higher in patients with Down syndrome, while muscular and subpulmonary ventricular septal defects were present only in patients without Down syndrome. The incidence of a cleft of the mitral valve was significantly higher in Down syndrome, while left-ventricular inflow and outflow obstructions were present only in patients without Down syndrome. Different patterns of ventricular septal defect and associated anomalies exist in patients with and without Down syndrome.

Abnormalities, Multiple↗

Acute effects of nisoldipine, propranolol, and their combination in patients with chronic stable angina: a double-blind, randomized, cross-over, placebo-controlled study.

We studied the short-term effects of oral administration of nisoldipine (10 mg) and propranolol (80 mg) alone and in combination in 14 patients with chronic exertional angina pectoris in a double-blind, randomized, cross-over study. The 14 patients (13 men and 1 woman, mean age 56 +/- 7 years) performed symptoms-limited bicycle exercise stress test 3 h after placebo or active substance administration. Maximal work load, exercise duration, and time to 1-mm ST segment depression were significantly increased and ST depression at peak exercise was significantly decreased by drugs alone and in combination. Propranolol and nisoldipine alone improved exercise duration similarly and as well as the combination; however, a different response to the three pharmacologic interventions was found in patients treated with single drugs. The improvement in exercise tolerance was associated with rate-pressure product values at peak exercise, unchanged after nisoldipine and significantly reduced after both propranolol alone and in combination. After placebo, all patients had exercise-induced angina, in 9, 8, and 4 patients after nisoldipine, propranolol, and the combination of the two drugs, respectively. Nisoldipine is effective in the treatment of effort angina and its combination with propranolol may be useful and superior in patients who show poor response to monotherapy.

Aged↗

[Interventricular muscular defect in the atrioventricular canal].

The muscular ventricular septal defect associated with the atrioventricular canal is a malformation which has not yet been extensively studied. Between June 1982 and December 1989, 151 patients with atrioventricular canal underwent echocardiography and angiocardiography in our Department. Of these 95 (62.9%) had a complete form and 56 (37.1%) a partial. Among the 151 patients, 81 (53.6%) presented Down syndrome. We found 5 muscular ventricular septal defects in 4 patients; in 3 cases there was a single defect and in one case two defects. These defects were midmuscular in all patients and one patient also presented an apical defect. All 4 patients with muscular ventricular septal defect presented a complete atrioventricular canal and aortic coarctation; 3 out of 4 patients had a hypoplastic left ventricle with absence of Down syndrome. The muscular ventricular septal defect is a malformation which is rarely associated with atrioventricular canal (4/151 = 2.6%). In our experience, it was always associated with a complete form with aortic coarctation and was very rare in Down syndrome patients (1/81 = 1.2%). These findings may represent a peculiar association of anomalies which may be caused by fetal hemodynamic mechanisms.

Abnormalities, Multiple↗

[Hypothermia treatment of junctional ectopic tachycardia after surgical repair of congenital heart defects].

Junctional ectopic tachycardia after surgical repair of congenital heart defects is associated with high mortality. Usually, it is transitory and resolves spontaneously, but a long period with very fast heart rate and without atrio-ventricular synchrony contraction may cause low cardiac output. Treatment with common anti-arrhythmic drugs is often uneffective both in restoring sinus rhythm and in reducing heart rate. Since hypothermia is known to decrease cardiac automaticity, two infants, aged 4 and 10 months, with junctional ectopic tachycardia and low cardiac output after surgical repair of the atrio-ventricular septal defect were treated with hypothermia after unsuccessful pharmacological attempts to control the arrhythmia. Generalized hypothermia was induced with cooling-blankets and ice packs. Rectal temperature initially dropped to 30 degrees and was subsequently maintained at between 33.8 and 34.2 degrees with the heart rate between 130 and 140 m beats per minute. Trans-oesophageal atrial pacing at a higher rate allowed for sequential atrio-ventricular contraction. Signs of low cardiac output were quickly resolved. One patient was warmed-up after 12 hours of hypothermia and remained in sinus rhythm. In the other patient, the arrhythmia recurred after rewarming and a further 30-hour period of hypothermia was required. Sinus rhythm was maintained thereafter. Both patients are in stable sinus rhythm 20 and 22 months after surgery. Our experience supports the use of hypothermia as a means to control post-operative junctional ectopic tachycardia resistant conventional anti-arrhythmic drugs.

Electrocardiography↗

Effects of aging and beta-adrenergic-blockade on standing-induced QT/QS2 changes.

In order to evaluate whether the changes in the electrical systole/electromechanical systole ratio (QT/QS2) may reflect the effects of beta-adrenergic stimulation on the heart, we studied the variations of this ratio induced by active standing. We studied 45 healthy volunteers aged 15 to 82 years, subdivided into three groups; Group 1 (mean age 22 +/- 4 years), Group 2 (mean age 44 +/- 6 years), and Group 3 (mean age 74 +/- 6 years). Fifteen subjects repeated the test after propranolol administration (0.1 mg/kg iv). Resting QT/QS2 ratio increased slightly, but not significantly, with age. Upright position significantly increased QT/QS2 ratio in all groups. Changes in heart rate (r = -.43), electromechanical systole (r = .55) and QT/QS2 were significantly correlated with age. Propranolol prevented the increase in QT/QS2 ratio induced by active standing. Therefore, QT/QS2 changes induced by standing are correlated with age and are inhibited or reduced by beta-blockade. QT/QS2 changes can be used to monitor adrenergic activity, even if their value is limited by the overlapping responses of the individual cases.

Adolescent↗

Relationship between QT interval duration and exercise-induced ventricular arrhythmias.

This study was performed to determine if QT prolongation before and during early exercise is related to the occurrence of exercise-induced ventricular arrhythmias (EIVA). EIVA occurred in 47 of 142 patients with angiographic evidence of coronary artery disease (CAD); no EIVA occurred among the 22 patients without CAD (OV). Resting QTc and QT intervals during early exercise were similar in patients without EIVA, irrespective of the presence or absence of CAD; however resting QTc was significantly longer in CAD patients who showed EIVA (443 +/- 40 ms; P less than 0.01) than in CAD patients without EIVA (424 +/- 37 ms) and in OV patients (421 +/- 32 ms). During early exercise, the QT interval remained significantly longer in patients with than in those without EIVA. There was a trend toward increasing resting QTc in patients who exhibited EIVA more severe than grade 3. When resting QTc was longer than 440 ms, subsequent EIVA were correctly predicted in CAD patients with a sensitivity of 43%, a specificity of 72% and a predictive accuracy of 63%. Thus, a trend toward longer resting QTc values exists in CAD patients who develop EIVA; however, a long resting QTc (greater than 440 ms) appears to be only a weak predictor of subsequent EIVA.

Adult↗

[Pulmonary atresia with an intact septum: indications for the neonatal surgical treatment guided by 2-dimensional and Doppler echocardiography].

Twelve neonates with pulmonary atresia and intact ventricular septum underwent surgical treatment based on two-dimensional and Doppler echocardiography. Ten patients with adequate morphology of the right ventricular outflow tract portion shown by means of two-dimensional echocardiography underwent pulmonary valvulotomy and systemic-to-pulmonary shunt. Two neonates with atresia of the right ventricular infundibulum on two-dimensional echocardiography underwent systemic-to-pulmonary artery shunt without valvulotomy. In all patients the qualitative and quantitative echocardiographic diagnosis was confirmed at surgery and/or with the subsequent angiocardiographic study. Two-dimensional and Doppler echocardiography is a precise diagnostic method for planning surgical treatment in neonates with pulmonary atresia and intact ventricular septum.

Echocardiography↗

Neuroanatomical and biochemical evidence for the involvement of the area postrema in the regulation of vasopressin release in rats.

Studies were carried out in the rat to determine if the area postrema (AP), a medullary circumventricular organ, might be involved in the control of vasopressin (VP) release. The data from this study demonstrate the existence of direct neural connections between the AP and the hypothalamic VPergic neurons of the supraoptic nucleus (SON) as showed by the retrograde tracer horseradish peroxidase (HRP). Labeled neurons were observed in the AP following HRP injections into the SON. In addition, rats with AP lesions showed an impaired ability to conserve water and concentrate their urine in response to an hypertonic NaCl load. They, also, failed to maintain sodium retention and showed an attenuation of VP release during intracellular dehydration. These findings indicate that AP plays an important role in the regulation of VP release during changes in osmotic environment and suggest that this medullary circumventricular organ is a part of central circuitry subserving salt-water balance.

Animals↗

Selective damage of neuron perikarya in the medial septum of the rat forebrain: effects on food and water intake, urine output and body weight.

The intraseptal administration of the neurotoxin kainic acid (KA) induced a significant depletion of the neuronal population and glial proliferation in medial septal areas. The behavioral effects induced by this selective destruction of the neurons indigenous to the medial septal areas were investigated. KA produced a marked increase in urine output and a transient reduction in body weight, but failed to affect water and food intake.

Animals↗

Evaluation of exercise-induced Q-wave amplitude changes and their clinical value.

We studied the influence of exercise level, severity of coronary artery disease (CAD), presence of previous myocardial infarction (MI), anterior or diaphragmatic, on the clinical value of exertional Q wave changes (Delta-Q). We retrospectively evaluated the exercise electrocardiograms of 62 patients without angiographic evidence of CAD and 133 patients with CAD; 28 of them had single (SVD) and 105 multivessel disease (MVD). Forty-one patients had a previous diaphragmatic MI and 23 anterior. The sensitivity, specificity and predictive value of Delta-Q were compared to the ST criterion. The exercise level affected Delta-Q. ST and Delta-Q had similar specificity and predictive values. The extent of CAD did not affect the sensitivity of Delta-Q and this method was better than ST to detect SVD patients. The Delta-Q criterion was equally as efficient as ST in MVD patients without MI and with diaphragmatic MI. The loss of septal forces on resting electrocardiograms made useless Delta-Q analysis on patients with anterior MI. The improvement of sensitivity in SVD patients by Delta-Q might be of clinical value since these latter are frequently not diagnosed by the ST criterion.

Adult↗

Diagnostic value of the ratio of recovery systolic blood pressure to peak exercise systolic blood pressure for the detection of coronary artery disease.

It has been previously reported that at treadmill exercise testing an abnormal ratio of recovery systolic blood pressure (SBP) to peak exercise SBP is more sensitive than exercise-induced angina or ST segment depression for diagnosing coronary artery disease (CAD). To investigate whether the SBP ratio keeps its diagnostic value during upright bicycle exercise, we evaluated the ratio of postexercise SBP to peak SBP in 73 patients with angiographically documented CAD and in 48 patients with normal coronary arteries (OV group) undergoing maximal stress testing on a bicycle ergometer. Three minutes after exercise ended, SBP ratio was significantly higher in the CAD than in the OV group (0.79 +/- 0.1 vs 0.71 +/- 0.08; p less than .001). Setting the upper normal limits of the recovery SBP ratio at 2 SDs from the mean for the OV group (SBP ratio = 0.98 and 0.88 at 1 and 3 min after exercise, respectively), with an increase or no change in SBP ratio at between 1 and 3 min of recovery considered an abnormal response, the sensitivity of SBP ratio was 30%, the specificity was 83%, and the accuracy was 51%. The respective values for ST depression were 81% (p less than .0001 vs SBP ratio), 48% (p less than .001 vs SBP ratio), and 67% (p less than .01 vs SBP ratio). Thus, for bicycle ergometer exercise testing, ST segment depression seems to be more accurate than SBP ratio in diagnosing CAD.

Adult↗