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Biomedical subjects

J J De Lima

Publications and source records attributed to J J De Lima.

At least 19 recordsLinked to original sources
PubMed2001

Baseline blood pressure and other variables influencing survival on haemodialysis of patients without overt cardiovascular disease.

BACKGROUND: Age, diabetes and concomitant cardiovascular disease, recorded at the initiation of dialysis, allows the identification of patients with a high probability of early mortality. When all of these factors are taken into account the mortality rate of dialysis patients is still 3.5 times higher than for the general population. Information on the factors that increase the mortality of patients lacking the major cardiovascular risk factors is important because these are likely to be correctable, especially if detected early. METHODS: We investigated prospectively the relevance of blood pressure and other variables recorded at the initiation of dialysis treatment on the survival of a group of 103 relatively young adult haemodialysis patients (mean age 44.3 years +/-13 SD), with a low prevalence of comorbidity and a median follow-up period of 79 months. Data were analysed by the Cox proportional regression model and survival curves were constructed by the Kaplan-Meier method. RESULTS: Forty-four patients died, 20 (46%) of whom as a result of cardiovascular causes. Multivariate analysis showed that mortality was associated with age (P=0.0001), serum creatinine (P=0.005, negative association), left ventricular (LV) mass (P=0.003) and hypertension (P=0.03). Mortality was increased by 7% for each additional year of age, by 0.7% for each 1 g increase in LV mass, and was reduced by 23% for each additional mg/dl of serum creatinine. Hypertensive patients had a higher probability (x2.2) of dying compared with normotensive patients. CONCLUSIONS: In addition to age and conditions of occult malnutrition, hypertension and LV hypertrophy, when present at the initiation of dialysis, play a major role in the mortality of low risk, relatively young dialysis patients. These potentially correctable factors should be actively sought and treated during the early stage of renal insufficiency to improve prognosis.

Adult↗
PubMed2001

First pass evaluation of blood velocity in the pulmonary artery.

Studying the kinetics of blood flow in the pulmonary artery using non-invasive techniques may be an important tool in assessing the prognosis of lung diseases. The aim of this study was to ascertain dynamic parameters of pulmonary blood flow, particularly the velocity of a small bolus of a radioactive tracer after intravenous injection. Since the shape and distribution pattern of the bolus changes substantially from frame to frame, common image processing techniques for motion detection or other techniques, such as accumulation of subtracted images, segmentation and spectral analysis with temporal/spatial filtering, are unable to properly evaluate the motion of the bolus. However, the passage of the bolus from the arm to the lungs was visualized with good contrast through acquisition of a first pass sequence of scintigraphic images. The wave form of the bolus becomes increasingly complex as it progresses towards the pulmonary artery. In the proposed method the time-activity curves for each pixel are displayed. It is assumed that the peaks of the maximum counts in these curves correlate with the time after injection that the bolus takes to cross each pixel (bolus head). The bolus head contains information on time, space and activity, and allows the velocity of the studied fluid to be calculated. We demonstrated a mean velocity through the pulmonary artery trunk in resting patients of approximately 11 cm/s, with a mean residence time of 0.5 s.

Algorithms↗
PubMed1999

Effects of FK506 in rat and human resistance arteries.

BACKGROUND: FK506 is widely used in organ transplantation and causes hypertension. However, little is known about the impact of the drug on the cardiovascular system. METHODS: We therefore investigated the effect of FK506 on resistance artery and blood pressure responsiveness to vasoconstrictors and vasodilators. Studies were conducted in vitro using human and murine resistance artery, ex vivo in resistance artery isolated from rats treated with FK506 (6 mg/kg/day), and in vivo in conscious, treated animals. RESULTS: In vitro exposure (24 hr) of human and rat resistance artery to FK506 (1000 ng/ml) increased the sensitivity to norepinephrine (NE) and impaired the response to acetylcholine (Ach) and sodium nitroprusside (SNp). In contrast, arteries isolated from rats given FK506 for eight days showed a reduced sensitivity to NE (P < 0.05) and a normal endothelium-dependent relaxation. Their incubation with L-arginine caused a significant reduction in Ach sensitivity in the FK506 group (P < 0.05) but not in controls, suggesting enhancement of nitric oxide production by the drug. The sensitivity to SNp was reduced, as in the in vitro experiments (P < 0.05). Rats given FK506 for eight days presented blood pressure similar to that in controls but also presented signs of a compensatory response to excess vasodilation: tachycardia (P < 0.01), reduced blood pressure sensitivity to NE and Ach, blunted heart rate response to both agonists, and exaggerated hypotension at high doses of Ach. After 21 days of treatment, blood pressure remained similar to that in controls, but resistance artery showed further functional deterioration, with significant impairment of the maximum responses to Ach and to SNp. CONCLUSION: FK506 presents significant vascular toxicity affecting mainly smooth muscle relaxation and alters vascular hemodynamics. The data suggest that similar cardiovascular changes may occur in transplant patients and represent the forerunner of hypertension often seen with more prolonged use of the drug.

Adult↗
PubMed1999

Outcome of patients with malignant hypertension and end-stage renal failure treated by long-term hemodialysis.

Malignant hypertension is associated with high mortality and morbidity usually caused by cardiovascular events. The course and prognosis of malignant hypertension patients treated with renal replacement therapy has not been thoroughly investigated. In the present work, we compared the clinical evolution and survival of 24 end-stage renal failure malignant hypertension patients with that of a group of individually matched renal failure patients admitted to the same dialysis center during a period of 21 years. Survival rates at 1, 5 and 8 years were 87, 82 and 50% for malignant hypertension patients and 87, 75 and 65% for controls, respectively (p = 0.766, NS). Nonfatal cardiovascular complications occurred in 2 individuals of each group. The most important cause of death in both groups was cardiovascular. The frequency of fatal cardiovascular events was similar in the two groups: 64% of deaths for malignant hypertension and 71% for controls (NS). In conclusion, previous malignant hypertension did not increase the risk of patients in long-term hemodialysis in our series.

Adolescent↗
PubMed1999

Cardiac effects of persistent hemodialysis arteriovenous access in recipients of renal allograft.

In hemodialysis patients, large arteriovenous (AV) fistulas for vascular access may cause ventricular hypertrophy and high-output cardiac failure. The long-term cardiac consequences of functional AV fistulas in renal transplant patients are unclear. A precise knowledge of these consequences is important to decide if and when such fistulas should be closed in successfully transplanted patients. In this retrospective study including 61 stable renal transplant patients with adequate renal function (serum creatinine <2.0 mg/100 ml), echocardiography was performed in 39 patients with a functional AV fistula (group 1) and in 22 whose fistulas had been closed, for esthetic reasons, within 2 months postoperatively (group 2). The volume flow of the fistulas, measured in 22 randomly selected individuals of group 1, was 900 +/- 350 ml/min (range 500-1,600). Patients of group 1 were older (40 +/- 12 vs. 33 +/- 12 years, p < 0.05), had longer duration of the fistula (62 +/- 31 vs. 36 +/- 30 months, p < 0.05), higher body mass index (24 +/- 4 vs. 22 +/- 3 kg/m2, p < 0.05), systolic (154 +/- 24 vs. 138 +/- 18 mm Hg, p < 0.05) and diastolic (96 +/- 12 vs. 89 +/- 11 mm Hg, p < 0.05) blood pressure and increased left ventricular (LV) end-diastolic dimension (53 +/- 5 vs. 49 +/- 5 mm, p < 0.01). LV mass, cardiac index, ejection fraction and the proportion of patients with LV hypertrophy were comparable in the two groups. LV end-diastolic dimension was positively and independently influenced only by the presence of the AV fistula (p < 0.01) after adjusting for age, duration of the fistula, body mass index, systolic and diastolic blood pressure and the nature of the antihypertensive drugs used. In conclusion, the persistence of large, high-flow AV fistulas for prolonged periods of time had little impact on cardiac morphology and function of stable renal transplant patients with adequate renal function. The data do not support routine closure of these fistulas in all renal transplant patients.

Adult↗
PubMed1999

Evaluation of the alveolar-capillary membrane permeability using 99mTc-HMPAO aerosols in severe diffuse interstitial fibrosis.

Local information on permeability of the alveolar-capillary barrier (PACB) can be ascertained by parametric images, after inhalation of radioarosols and computer processing. Our aim is to compare the results of 99mTc-HMPAO aerosols on PACB studies with those of 99mTc-DTPA aerosols, a standard technique. We compared the two techniques in separate samples: normal controls and patients with severe lung interstitial pathologies. Perfusion studies using 99mTc-MAA have also been performed in all patients. The aerosols were produced using ultrasound and lowered surface tension solution of 99mTc-HMPAO and 99mTc-DTPA. The time-activity curves (TACs) for every pixel on the lung area were used to calculate the half-disappearance times (T1/2). Parametric images were then generated with those times. The comparison of the results obtained with 99mTc-HMPAO and 99mTc-DTPA aerosols suggests that the first ones are more specific for local alterations of the lung epithelial transport in the pathologies studied. This method distinguishes between permeability deficiency due to local perfusion decrease and ACB deterioration.

Aerosols↗
PubMed1998

Plasma kinetics of chylomicron-like emulsion in renal transplant patients receiving cyclosporin-based immunosuppression.

BACKGROUND: Atherosclerotic cardiovascular disease is prevalent among renal transplant patients. Increase in serum total cholesterol, low-density lipoprotein, and very low-density lipoprotein is common in those patients. Alterations in chylomicron metabolism, however, are also related to atherogenesis and were not studied in renal transplant. HYPOTHESIS: The aim of this study was to evaluate chylomicron metabolism in renal transplant recipients receiving cyclosporin-based immunosuppression. We determined the plasma kinetics of triglyceride-rich emulsions labeled with [3H]triolein and [14C]cholesteryl oleate that are known to mimic the chylomicron metabolism when injected into the blood stream. METHODS: Fourteen renal transplant recipients with normal renal function (10 men, 4 women, aged 40 +/- 6.1 years) and 17 age- and gender-matched healthy controls received bolus injections of the chylomicron-like emulsion. Plasma samples were then taken at regular intervals during 60 min. Disappearance curves of the labels and the respective fractional clearance rates (FCR) were calculated in order to measure lipolysis and chylomicron remnant removal from the plasma. RESULTS: Fasting serum lipid levels did not differ in the two groups. The difference between Median FCR of [3H]triolein emulsion in renal transplant patients and that obtained in the controls (0.07 vs. 0.11 min-1, NS) was not statistically significant. Median FCR of [14C]cholesteryl oleate also did not differ between the groups (patients: 0.044; controls: 0.046, NS). CONCLUSION: These results indicate that neither chylomicron lipolysis nor remnant removal are affected in stable renal transplant patients treated with cyclosporin-based immunosuppression.

Adult↗
PubMed1998

Human leukocyte antigens and malignant essential hypertension.

The purpose of this study was to investigate an association between human leukocyte antigens (HLA) and the susceptibility to malignant hypertension. The presence of HLA-A, -B, -DR, and -DQ was determined in 33 white and in 23 mulatto Brazilian patients with malignant essential hypertension. No statistically significant differences were detected between patients and control subjects. It is nevertheless important to note that we have observed an increased frequency of DR3 in the mulatto patients (34.8% v 21.4%). We consider that this finding supports the existence of an HLA-DR3 association with hypertension in the black population, as has been claimed by other authors.

Adult↗
PubMed1998

Lack of effect of a single oral dose of cyclosporine on systemic blood pressure and on forearm blood flow and vascular resistance in humans.

The acute hemodynamic effect of cyclosporine in man is controversial. A randomized, double blind, placebo-controlled, cross-over study was undertaken to evaluate the effect of a single oral dose of cyclosporine (20 mg/kg body weight) on mean blood pressure (MBP), heart rate (HR), forearm blood flow (FBF), and vascular resistance (FVR) in 16 healthy adult subjects. Subjects were studied twice, with an intervening period of 2 weeks, before and after the administration of either cyclosporine or the vehicle olive oil. Blood pressure was measured on brachial and digital arteries. After 30 min of rest, basal measurements were obtained and individuals were randomly assigned to receive either cyclosporine or the vehicle, and the same measurements were repeated 2 h later. Mean whole blood levels of cyclosporine were 1542+/-387 ng/mL (range 1000 to 2550) 2 h after the administration of a single oral dose of cyclosporine. Cyclosporine did not cause any significant change in the hemodynamic parameters when compared with vehicle. Pre- and post-cyclosporine data were as follows (means +/-/SD): MBP (determined by Finapres on the digital artery), 92+/-10 v 95+/-11 mm Hg; HR, 66+/-10 v 68+/-11 beats/min; FBF, 3.90+/-1.3 v 3.8+/-1.8 mL/ 100 mL/min; and FVR, 28+/-9 v 33 +/-18 units, respectively. For the vehicle the results were: MBP, 94+/-9 v 94+/-9; HR, 67+/-9v 67 /-11; FBF, 3.3+/-1.6 v 3.2+/-2.0; FVR, 35+/-14 v 37+/-15, respectively. These figures did not differ from those obtained with the auscultatory method applied to the brachial artery among 10 selected subjects studied with Finapres. In conclusion, we found no evidence that at supratherapeutic doses cyclosporine causes acute increase in blood pressure or peripheral vasoconstriction in humans.

Administration, Oral↗
PubMed1998

Baseline variables associated with early death and extended survival on dialysis.

Patients who die during the first three months on dialysis are not systematically included in the American and European statistics. In contrast, only a few patients survive more than 10 years on this modality of renal replacement therapy. The factors determining these two extreme forms of outcome are poorly understood. We tested the hypothesis that a few variables, easily obtainable at the initiation of dialysis, would identify those individuals at high and low risk of early death. We retrospectively studied 23 patients who died within 90 days of initiating dialysis and 20 patients who survived more than 10 years. These patients were admitted for dialysis to a Brazilian center between July 1, 1976 and February 28, 1997. The baseline variables assessed which were thought to influence survival, were: age, sex, race, body weight, etiology of renal disease, blood pressure, comorbid conditions, hematocrit and serum electrolytes, albumin, creatinine, urea, and urea/creatinine ratio. Univariate analysis showed that patients who died early were older (56.2 +/- 15.6 vs. 42.1 +/- 10.4 years, p < 0.01), had lower serum creatinine (10.6 +/- 2.9 vs. 13.7 +/- 3.7 mg/dL, p < 0.01) and albumin (3.3 +/- 0.9 vs. 4.0 +/- 0.5 g/dL) and a higher urea/creatinine ratio (18.4 +/- 5.8 vs. 13.5 +/- 4.8, p < 0.01) compared with subjects surviving more than 10 years. Early death patients also had more cases of diabetes (35% vs. 0%, p < 0.01) and less chronic glomerulonephritis (9% vs. 35%, p < 0.05). Multivariate analysis showed that age (p < 0.01, CI 1.02 to 1.15, odds ratio 1.1) and urea/creatinine ratio (p < 0.01, CI 1.03 to 1.38, odds ratio 1.2) were positively and independently related to outcome. In the early death group, malnutrition was an important cause of death (17% of all deaths). Compared to baseline data, long-term survivors, at the last follow up, presented reduced systolic blood pressure and increased hematocrit and unchanged body weight, serum albumin and urea/creatinine ratio. These results, based on easily accessible initial variables, suggest that early death on dialysis is influenced by age and by indices related to the nutritional condition of the patients. They also highlight the importance of a potentially correctable risk factor in a population with an elevated prevalence of premature death.

Brazil↗
PubMed1997

Early elevation of lipoprotein(a) levels in chronic renal insufficiency.

Serum lipoprotein(a) [Lp(a)] concentrations in chronic renal failure patients were investigated in relation to the degree of renal insufficiency, treatment by maintenance hemodialysis, and correction of uremia by renal transplantation with or without cyclosporin immunosuppression. Fast serum levels of Lp(a) (mg/100 mL) were determined in 34 chronic renal failure patients not in need of maintenance dialysis (16 with serum creatinine 2.0-4.0 mg/100 mL; 18 with serum creatinine higher than 4.0 mg/100 mL), 40 patients treated by hemodialysis, 55 successful renal transplant recipients (28 under cyclosporin treatment and 27 receiving no cyclosporin), and 34 healthy controls. Age and sex distributions were similar among groups. Pregnant women; non-White individuals; subjects with obesity, diabetes, nephrotic syndrome, and hepatic and thyroid diseases; and those treated with oral contraceptives or lipid-lowering drugs were excluded from the study. Compared to controls, median Lp(a) was increased in nondialyzed renal failure patients (11 vs. 47.5 p < 0.001) and this was the only lipid abnormally observed in the group. There was no significant difference in Lp(a) levels between nondialized renal failure patients with serum creatinine 2.0-4.0 and > 4.0 mg/100 mL (47 vs. 49, NS). Moreover, Pearson correlation coefficient (r = 0.01, NS) showed that Lp(a) values were not related to serum creatinine in nondialyzed patients, In hemodialysis subjects Lp(a) concentrations (median = 29) were intermediate between those observed in nondialyzed patients and controls but the differences were not significant. Lp(a) levels in renal transplant patients treated with cyclosporin (median = 6) and not receiving cyclosporin (median = 13) were similar and did not differ from controls. Serum Lp(a) increases and attains maximum levels with mild/moderate reduction in renal function, and does not seem to change through late renal failure stages or in relation to the introduction of maintenance hemodialysis treatment. Correction of uremia by successful renal transplant caused normalization of Lp(a) levels regardless of the use of cyclosporin. Increased Lp(a) levels may be the earliest and more consistent lipid alteration seen in predialysis renal failure.

Adult↗
PubMed1995

Comparison of echocardiographic changes associated with hemodialysis and renal transplantation.

Long-term hemodialysis has been reported to cause progression of left ventricular (LV) hypertrophy with a tendency toward asymmetric septal hypertrophy. Renal transplantation is believed to reverse some of these changes. The aim of this prospective study was to compare the effects of long-term hemodialysis and of successful renal transplantation on cardiac structure and function assessed by echocardiography. Fifty-three patients were submitted to two echocardiographic evaluations separated by a 30 +/- 8 month interval. At the first control, all patients were on hemodialysis; at the second, 36 patients remained on dialysis while 17 had been submitted to renal transplantation. Age (44 +/- 13 vs. 40 +/- 10 years), gender (male, 50% vs 53%), and duration of dialysis at the initiation of the study (43 +/- 34 vs. 47 +/- 32 months) were comparable in the 2 groups. The prevalence of LV hypertrophy were 83% (first control) and 69% (second control) in the dialysis group and 82% and 71% in the transplant group. Comparisons between the two periods within each group showed that hemodialysis was associated with a significant reduction of the E/A ratio (1.25 +/- 0.4 vs. 1.02 +/- 0.4, p < 0.001) and systolic (155 +/- 28 vs. 137 +/- 26 mm Hg, p < 0.001) and diastolic (94 +/- 21 vs. 84 +/- 16 mm Hg, p < 0.05) blood pressure, and no change in LV mass index (171 +/- 51 vs. 156 +/- 43 g/m2, NS). In the transplanted group, there were reductions in the E/A ratio (1.42 +/- 0.6 vs 1.10 +/- 0.4, p < 0.05) and in LV diastolic dimension (50 +/- 7 vs. 46 +/- 5 mm, p < 0.05), but not in systolic (155 +/- 27 vs. 152 +/- 31 mm Hg, NS) or diastolic (97 +/- 11 vs. 97 +/- 20 mm Hg, NS) blood pressure. The LV mass index also did not change significantly (157 +/- 51 vs. 133 +/- 31 g/m2, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Blood pressure influences the occurrence of complex ventricular arrhythmia in hemodialysis patients.

We investigated the relationship between blood pressure and the occurrence of complex ventricular arrhythmias (multiform, couplets, or runs) as assessed by 48-hour Holter monitoring in 74 stable long-term hemodialysis patients (44.5 +/- 12 years old; 54% men; 74% whites; dialysis duration, 51.3 +/- 36.1 months; systolic pressure, 146.6 +/- 19.3 mm Hg; diastolic pressure, 89.2 +/- 12.1 mm Hg; prevalence of arterial hypertension, 33.8%). Systolic and diastolic pressures represented the average of all predialysis determinations during the 3 months preceding the tests. Hemodialysis was performed midway through the Holter monitoring period. M-mode and bidimensional echocardiograms and myocardial perfusion tests were also obtained from all patients. Complex arrhythmias were observed in 37 individuals (50%). Univariate analysis showed that systolic pressure (P < .001), diastolic pressure (P < .05), age (P < .001), left ventricular posterior wall thickness (P < .01), left ventricular mass index (P < .05), and ischemic alterations on myocardial perfusion tests (P < .005) were significantly associated with complex arrhythmias. With the use of a multivariate model (stepwise logistic regression analysis) only systolic pressure (P < .01) and age (P < .05) were independently associated with complex arrhythmias. Sex; angina; dialysis duration; New York Heart Association functional class; use of digitalis; plasma levels of creatinine, sodium, potassium, calcium, and phosphate; hematocrit; left ventricular fractional shortening; left ventricular diastolic diameter; and ST segment deviation were not correlated with complex arrhythmias. The severity and frequency of complex arrhythmias were not influenced by hemodialysis. At follow-up (5 to 80 months) 5 patients had died of sudden death, 4 of whom were hypertensive and older than 45 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Predictors of mortality in long-term haemodialysis patients with a low prevalence of comorbid conditions.

BACKGROUND: Total and cardiovascular mortality rates for haemodialysis patients are still high despite the continuous improvement of dialysis technology. This trend may be a consequence of the increased number of elderly patients and patients with concurrent systemic diseases admitted to dialysis programmes. The objective of the present investigation was to determine the predictors of mortality more closely related to uraemic status and to dialysis treatment by studying relatively young haemodialysis patients with a low prevalence of comorbid conditions using the Cox proportional hazards model. METHODS: Seventy-four haemodialysis patients with a low prevalence of extrarenal diseases (mean age 44.5 +/- 12.1 years, mean dialysis duration 51.3 +/- 36.1 months) were submitted to extensive cardiological and clinical evaluation and followed prospectively for a median period of 60.8 months (range: 5.1-79.8). There were only three diabetics and all patients denied previous myocardial infarction. RESULTS: At follow-up 23 patients had died, 10 of cardiac causes. Five-year survival rates were 70% for overall mortality and 83% for cardiac mortality. Age over 44 years (relative risk 3.73; 95% confidence interval 1.35-10.26) and serum creatinine (inverse correlation) (relative risk 0.73; 95% confidence interval 0.57-0.94) were shown to be independently associated with global mortality by the Cox proportional hazards analysis. Gender, race, dialysis duration, interdialytic weight gain, angina, NYHA classification, hypertension, LV hypertrophy, LV systolic and diastolic dysfunction, complex ventricular arrhythmias and altered myocardial perfusion tests were not significant predictors of overall mortality. There were crude associations between cardiac mortality and cardiothoracic and Sokolow indices (P < 0.01) and age, NYHA classification, systolic hypertension, LV wall and septum hypertrophy, LV dilatation and complex ventricular arrhythmias (P < 0.05). CONCLUSION: In the absence of serious comorbid conditions, the survival of patients on long-term haemodialysis is influenced by nutritional status (as indicated by lower serum creatinine) and age.

Adult↗
PubMed1992

Role of arterial hypertension in left ventricle hypertrophy in hemodialysis patients: an echocardiographic study.

To assess the role of arterial hypertension in left ventricle (LV) hypertrophy among hemodialysis patients, echocardiographic evaluation was performed in 10 hypertensive and 13 normotensive hemodialysis subjects matched for age, sex, race, duration of dialysis treatment and degree of interdialytic volume expansion. We excluded from the latter group patients with previous hypertension since hypertensive heart disease may persist after adequate blood pressure control. We also studied 17 normal controls and 10 non-uremic patients with essential hypertension. Comparisons between the two uremic groups showed that the hypertensive patients had a higher mass index (222 +/- 74 x 108 +/- 26, p = 0.0001) and posterior wall thickness (12 +/- 2 x 9 +/- 2, p = 0.0001) and a reduced LV radius/wall thickness ratio (4.4 +/- 0.7 x 5.8 +/- 1, p = 0.0001). There were no significant echocardiographic differences between normal controls and normotensive uremics. In contrast, compared to controls, hypertensive uremic patients showed an increased LV mass index (222 +/- 74 x 83 +/- 21, p = 0.0001) and posterior wall thickness (12 +/- 2 x 7 +/- 1, p = 0.0001) and a reduced LV radius/wall thickness ratio (4.4 +/- 0.7 x 6.5 +/- 1.1, p = 0.001), characterizing concentric hypertrophy. They also had ventricular dilation with larger LV dimensions than in controls (53 +/- 5 x 47 +/- 4, p = 0.004). In patients with essential hypertension, the mass index (135 +/- 22), wall thickness (11 +/- 1) and LV radius/wall thickness ratio (4.3 +/- 0.7) significantly differed (p = 0.0001) from those in the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Solar radiation--physicochemical aspects].

The solar radiation spectrum and the properties of its components are studied in the present paper. The history of the sun rays before reaching earth surface is analysed. A simplified analysis of the interaction mechanisms of these components with molecules, the energy absorption capabilities of the latter and the expected biological consequences are considered. Special emphasis are given to the properties of ultra-violet and infra-red radiations and their production considered.

Radiation↗
PubMed1992

[Intelligent instrumentation in medicine].

The introduction of intelligent robots, expert systems and other forms of intelligent automatization in the current practice of medicine seems to be inevitable. It appears interesting to look back to the efforts that have been done, since the former steps, about three decades ago and consider the prospects in this field for both short and long term. Simultaneously it is interesting to reckon the new aspects which are raised with the evolution of these methodologies such as the responsibility of decisions taken by intelligent systems, the probable advantages, at the present stage, of the interactive systems and the risk of self-learning systems. Some efforts carried out in our department in this field are described.

Artificial Intelligence↗