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Biomedical subjects

L Palla

Publications and source records attributed to L Palla.

At least 19 recordsLinked to original sources
PubMed1992

[Digital radiology with storage phosphors in cephalometric study in orthodontics].

Conventional radiology is continually modified with the development of digital systems which can be used for several types of radiologic examinations. Our study was aimed at evaluating the advantages of these new technologies in the orthodontic field, where the problems associated with image quality and radiation protection are major especially in young patients; the latter goal is achievable by dramatically reducing radiation dose and by avoiding repeating the exam. In our study, we compared lateral teleradiographs of the skull for cephalometric analysis obtained using conventional and digital diagnostic methods. The preliminary results demonstrated that the two imaging techniques did not differ relative to bone structure representation, even though the digital system provided better visualization of soft tissue structures. Computed radiography also allowed a marked reduction in the number of repeats and reduced radiation dose. The current disadvantages of this imaging method are the high initial cost of the equipment, reduced work rate, and the need of frequent technical assistance.

Adolescent↗
PubMed1991

[Double-contrast enema. Study of the mucosal pattern and the organ profile with conventional and digital methods].

A solid state digital system (FCR 101) was employed in our comparative evaluation of the image quality of conventional versus digital techniques in the study of colon by means of double-contrast enema. Sixty patients were examined with a single AP view, using digital radiography with 100% radiation dose and progressive 50% and 75% reductions; the radiographs thus obtained were then compared with the corresponding conventional ones. The examined parameters were organ profile and mucosal pattern. Each digital and conventional radiograph was evaluated by 2 independent radiologists and a value was given to each parameter i.e., 1 = good, 2 = sufficient, 3 = insufficient. Upon comparison of the average values obtained for digital and conventional radiographs in optimal conditions and with a dose reduced by 50%, the digital technique was seen to give a more detailed and accurate representation of both low-contrast mucosal pattern and of organ profile. With the dose reduced by 75%, a slight increase was observed in background noise which caused a slight loss in image definition, but this did not reduce image readability with respect to conventional radiographs. To conclude, the digital method with a 50% exposure reduction is to be preferred in the examination of the colon, especially in pediatric radiology; furthermore, since this technique allows better detailing at lower contrast, it is to be preferred in the study of the pathologic conditions affecting mainly/only the mucosal pattern--e.g., cancer, ulcerative colitis, Crohn's disease, and so on. An exposure dose reduced by 75% may be used for following lesions previously diagnosed and when a less detailed depiction of the mucosal pattern is enough.

Adult↗
PubMed1990

[Telemetric surveys in plant pathology and for taking the census of ungulates].

Two new applications of the remote sensing techniques in the territory management which make use of a thermal scanner, are described here: the first concerned with the vegetal pathology field and the second with the big game censusing the Castelporziano farm. The former constitutes an improvement of the usual techniques either for its quick performance or for being an uncurrent intervention on plants, the latter allows to realize censuses also in thickly bushy or woody lands, where the usual methods of counting "at sight", besides to need a large staff are not much reliable.

Agriculture↗
PubMed1989

Microalbuminuria and casual and ambulatory blood pressure monitoring in normotensives and in patients with borderline and mild essential hypertension.

Several reports suggest that urinary albumin excretion may be elevated in patients with essential hypertension and that this index may be a good predictor for cardiovascular complications. The aim of this study was to compare 24-hour urinary albumin excretion in a group of normotensives, borderline, and untreated mild hypertertensives and to assess, in a subgroup of them, the possible relations between microalbuminuria and arterial blood pressure. Fifteen normotensives, 16 borderline, and 19 mild hypertensive patients were studied. Slightly but significantly higher values of microalbuminuria were observed in the mild hypertensives compared to the other two groups. In 21 borderline and mild hypertensive patients 24-hour microalbuminuria was related to casual blood pressure and noninvasive ambulatory blood pressure monitoring. A significant correlation was found between microalbuminuria and average day-time diastolic blood pressure. Our data suggest that albumin excretion is slightly increased in mild arterial essential hypertension; the direct association between microalbuminuria and arterial diastolic blood pressure during daily activities seems to confirm a pathophysiological link between transcapillary protein escape and arterial blood pressure that warrants further studies.

Adult↗
PubMed1987

Renal scintigraphic captopril test in the diagnosis of renovascular hypertension.

Angiotensin converting enzyme (ACE) inhibitor-induced renal failure has been reported in bilateral renal artery stenosis and in stenosis in solitary kidneys, but not in unilateral renal artery stenosis. In these patients, however, a functional impairment of the kidney ipsilateral to the stenosis can often be detected after ACE inhibition by scintigraphic techniques employing glomerular radionuclide tracers like 99mTc-diethylenetriamine pentaacetic acid (DTPA). Dynamic renal scintigraphy with 99mTc-DTPA before and 1 hour after administration of captopril, 25 mg (renal scintigraphic captopril test; RSCT), was performed in a selected series of 39 hypertensive subjects with suspected renovascular hypertension. Changes in glomerular filtration rate induced by captopril on the individual kidney were estimated by assessing the early (120-180 seconds) DTPA uptake by the kidney. Values were expressed as the ratio between the kidney with the lower uptake and the contralateral one in 34 patients and as the ratio of the kidney counts to the injected dose in five patients with solitary kidneys, aortic coarctation, or both. Compared with precaptopril values, postcaptopril uptake decreased markedly in 14 subjects (-62.42 +/- 30.94 [SD]%; range, -25 to -100%) and decreased modestly or even increased in the other 25 (+0.57 +/- 9.83%; range, +28 to -13%). Of the 14 subjects considered to be RSCT-positive diagnostic workup revealed either established (10) or strongly suspected (2) renal artery stenosis in 12 and aortic coarctation in 2 subjects. In another patient with established renovascular hypertension, results of the RSCT were negative when performed in the supine position but became positive when repeated in the sitting position.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Changes in renal function during physical and mental effort.

Aim of the study was to evaluate the renal responses to physical and mental effort in essential hypertension by means of a non-invasive radioisotopic method. Renal uptake rate of Tc99m-DMSA was evaluated in 10 subjects. Starting from 5 to 15 minutes after dose injection counts over the kidney region were acquired by means of a gamma-camera time-activity curves were obtained for each kidney. In non-stimulated patients DMSA uptake rate increased regularly; in the remaining cases both isometric exercise and mental effort induced an abrupt reduction of the uptake rate which increased again after the end of the test. Although the relation of DMSA uptake rate to renal function is not yet fully understood, we tentatively interpret these results as indicating blood flow reductions during these stressful conditions.

Humans↗
PubMed1985

Arterial blood pressure and the renin-angiotensin-aldosterone system during postural changes in hypertensive patients with unilateral renal mobility.

Unilateral renal mobility was identified in 27 out of 100 essential hypertensive patients by examination of renal scintiphotos. The pattern of response to postural changes of blood pressure (BP), plasma renin activity (PRA) and plasma aldosterone concentration (PAC) was investigated in 11 patients with renal mobility and without treatment and compared with that of an age- and sex-matched group of untreated hypertensives without renal mobility. The patients with renal mobility had higher BP levels (X +/- SD mm Hg: supine 185 +/- 39/112 +/- 18 vs. 149 +/- 18/97 +/- 14; upright 167 +/- 38/108 +/- 17 vs. 144 +/- 7/93 +/- 10; p less than 0.05). Significant correlations were obtained in the patients with renal mobility (but not in those without renal mobility) between upright PRA and PAC (p less than 0.001), their postural variations (p less than 0.01) and between upright PRA (and PAC) and BP levels (p less than 0.05). The high prevalence of renal mobility in hypertension and the relationship observed between the activated renin-angiotensin-aldosterone system and BP in this condition suggest the importance of searching for unilateral renal mobility when examining the renin-angiotensin-aldosterone system in hypertensive patients, particularly during postural manoeuvres.

Adult↗
PubMed1985

Acute effect of captopril on single kidney glomerular filtration rate in arterial hypertension.

Recent studies have reported that captopril can acutely induce a marked decrease of glomerular filtration rate in kidneys affected by renal artery stenosis, an effect detectable by scintigraphic techniques. Experience which confirms and extends this observation, obtained in five patients with renovascular hypertension, is reported here. For comparison, eight essential hypertensives and six patients with non-vascular unilateral renal diseases were studied. In each patient the ratio of glomerular filtration rate between the two kidneys was estimated during two consecutive scintigraphic studies with the glomerular tracer 99mTc-DTPA: in all renovascular patients captopril induced a marked decrease of glomerular filtration rate on the affected side, whereas negligible changes were observed in all other subjects. These results confirm that captopril may almost completely suppress glomerular filtration in kidneys affected by unilateral renal artery stenosis, an effect which may not be apparent clinically because of compensation by the other kidney, but which is scintigraphically detectable. Renal scintigraphy after captopril is easy to perform and non-invasive. It therefore seems to be a promising tool for the screening of renovascular hypertension.

Captopril↗
PubMed1974

[New diagrams for quick calculation of refrigerating machines (author's transl)].

The present edition is a re-elaboration and an extension of a previous one and takes into account the data meanwhile brought up to date--concerning the characteristics of saturated vapours--as well as the opportuneness of an easier consultation. In fact, by introducing logarithmic scales and by an appropriate choice of the logarithmic modulus, it has been possible to summarize the characteristics of each fluid in one diagram only, whereas, in the first edition, the extension of the metric scales of the abcissas imposed to divide each diagram in two parts. Besides, more units have been introduced, namely: m3/kcal, m3/kj and ft3/Btu for volumes; oF and oC degrees for temperatures. These new diagrams have heen developed for the following refrigerant fluids: R 11, R 12, R 13, R 13 B1, R 22, R 114, R 502, NH3 and CH3Cl. Known the temperature before the throttling device, the evaporating temperature and the one of the eventual superheating, they enable to promptly calculate the volume of the refrigerant in the gaseous phase, both as dry saturated vapour and superheated vapour; besides, they allow the quick calculation of the speed of the fluid inside thepiping system, the performance of the compressor under different working conditions and with different refrigerants, and so on. A number of practical examples illustrate even more clearly what stated about quickness and possibilities of calculation.

Refrigeration↗
PubMedDate not supplied

Kidney scintigraphy after ACE inhibition in the diagnosis of renovascular hypertension.

Suppression of the renin-angiotensin system (RAS) by angiotensin converting enzyme (ACE) inhibition may induce renal failure in patients with bilateral renal artery stenosis. Recent scintigraphic studies with the glomerular tracer technetium-99m-diethylenetriaminepenta-acetate (99m-Tc DTPA) indicate that in patients with unilateral renal artery stenosis, glomerular filtration rate (GFR) may be markedly reduced in the affected kidney after inhibition of ACE. This finding reflects the important role of the RAS in maintaining GFR (by increasing postglomerular resistance) in states of low renal perfusion pressure. Preliminary observations suggest that this scintigraphic test might be useful in the detection of renovascular hypertension.

Captopril↗
PubMedDate not supplied

[Radiologic study of the thorax using the digital method (FCR 101). Evaluation of various parameters as related to exposure].

A computed radiography system with solid state detectors (FCR 101) was employed to evaluate the quality of digital images, with optimal and progressively lowered doses, in the study of the chest. Routine chest radiographs of in patients with no pathologic conditions of the chest were studied. The patients were divided into 3 groups: each patient in group A underwent two radiographs, one at 100% and the other at 50% exposure; patients in group B were imaged with 100% and 25% doses, and those in group C received 50% and 25% exposure. Several parameters were employed for image evaluation, and a value was given to each of them (1 = good, 2 = sufficient, 3 = insufficient). Upon comparison of the average values obtained, we observed that the digital technique allowed a most accurate and well-defined representation of the examined parameters at 100% exposure dose and that a 50% reduction did not decrease the informative content in the least. A 25% reduction, however, determined a high degree of background noise and a subsequent, though slight, loss of information.

Adult↗