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Biomedical subjects

R Palla

Publications and source records attributed to R Palla.

At least 55 records · Page 3Linked to original sources

Fractional shortening/end-systolic stress correlation in the evaluation of left ventricular contractility in patients treated by acetate dialysis and lactate haemofiltration.

Fractional shortening/end-systolic stress (FS/ESS) correlation by echocardiography is a reliable index of left ventricular function. Acetate infusion or preload reduction due to water compartment re-equilibrium may induce ventricular derangements during dialytic treatment. In 13 patients on lactate haemofiltration (LHF) (mean age 56.8 +/- 11.9 years on regular dialytic treatment (RDT) for 75.3 +/- 56.5 months) and in seven patients on acetate haemodialysis (AHD) (mean age 48 +/- 10.7 years; on RDT for 43.9 +/- 49.2 months) fractional shortening/end-systolic stress was evaluated before and after single dialytic session. The following biochemical parameters were also studied: haematocrit (Htc), plasmatic osmolarity, ionised Ca, Na, K, and blood gases. In both groups the mean fractional shortening/end-systolic stress correlation maintained the same correlation coefficient before and after treatment (r = -0.68, P less than 0.001). Lactate haemofiltration and acetate haemodialysis by reducing the volume expansion and preload (mean interdialytic body-weight increase 2.5 +/- 0.8 kg in our patients), may decrease left ventricular contractility (Starling's law). Furthermore, acetate was postulated as a myocardial depressant. Dialysis-induced myocardial contractility variations plotted against fractional shortening/end-systolic stress correlation allowed the division of our patients into four different groups: (1) patients with increased fractional shortening and reduced end-systolic stress; (2) patients with unchanged fractional shortening and reduced end-systolic stress; (3) patients with reduced fractional shortening and increased end-systolic stress; and (4) patients with reduced fractional shortening and unchanged or reduced end-systolic stress. These groups include patients treated with either lactate haemofiltration or acetate haemodialysis. Our data cannot confirm the postulated acetate myocardial depressant activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗

Lack of nocturnal serum thyrotropin (TSH) surge in patients with chronic renal failure undergoing regular maintenance hemofiltration: a case of central hypothyroidism.

Thyrotropin (TSH) secretion was evaluated in a group of patients with chronic renal failure (CRF) undergoing regular maintenance hemofiltration and in normal controls. The study group included 68 patients (39 males and 29 females, age range 39-73 years, mean: 53 years). In all patients blood was drawn at 08:30-09:00 h; in 20 patients the nocturnal (24:00-02:00 h) serum TSH peak was also evaluated; 12 patients underwent stimulation test with synthetic TSH-releasing hormone (TRH). TSH was measured by an ultrasensitive immunoradiometric assay. CRF patients showed a significant decrease in serum total and free thyroxine and triiodothyronine concentrations, which in a substantial proportion of subjects were below the lower normal limit. Serum reverse triiodothyronine and thyroxine-binding globulin values did not differ in the two groups. Despite this trend of thyroid hormones to decrease, no patient had supranormal TSH values as in primary hypothyroidism. While the mean morning TSH concentrations of CRF patients did not differ from those of controls, the mean nocturnal values were significantly reduced in CRF (1.0 +/- 0.2 vs 3.2 +/- 0.4 mU/l, p less than 0.0005) and the nocturnal serum TSH surge was not observed in 18 of the 20 patients (90%) in whom it was evaluated. The mean serum TSH peak value after TSH-releasing hormone (TRH) administration was also reduced in CRF patients, and the TSH response to TRH was blunted in 3 out of 12 patients (25%). The results of this study demonstrate a major impairment of TSH secretion in CRF, which baseline TSH measurements in the morning and the evaluation of the TSH response to TRH may not reveal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Renal effects of enalapril in hypertensive patients with glomerulonephritis.

Renal effects of enalapril maleate in ten hypertensive patients with glomerulonephritis were evaluated after 1 and 16 weeks of therapy. Systemic blood pressure decreased, glomerular filtration rate was not significantly changed, and sodium fractional excretion and renal plasma flow increased, whereas renal vascular resistances and filtration fraction decreased acutely at the end of the study. Proteinuria diminished, but no variations in qualitative pattern were observed. ACE inhibitors, promoting efferent rather than afferent arteriolar vasodilatation and reduction of glomerular permeability coefficient, may reduce glomerular capillary hypertension and the development of proteinuria.

Blood Pressure↗

Ultrafiltration: a rational treatment for heart failure.

Patients with late-stage congestive heart failure with significant fluid overload respond well to ultrafiltration. The response is relatively long-standing and includes enhanced responsiveness to diuretics. Ultrafiltration is simple and highly cost effective. Furthermore, it possesses many advantages over massive or drastic pharmacological therapy. In the following paper, we report our own experience and review the world literature.

Blood Volume↗

Fibrinolytic effects of urokinase and heparin in acute pulmonary embolism: a randomized clinical trial.

Dissolution of pulmonary emboli with heparin and urokinase is ascribed, respectively, to anticoagulation and fibrinolysis. Since truly independent assessment of these effects in man is lacking, we administered each drug alone. Fibrinogen and plasminogen plasma levels and the resolution of pulmonary emboli were measured in three randomized groups of 10 patients each: groups A and C infused with small repeated doses of urokinase and a large single dose of urokinase, respectively, and group B who received heparin. After 6 h of treatment, fibrinogen fell in all the groups, while, after 12 h, remained equally reduced in groups A and B and declined further in group C. Plasminogen behaved similarly. Up to 60 h, statistical analysis showed that these effects were related to timing and amounts of urokinase and heparin infusion. These observations suggest that heparin may induce a lytic state. As to signs of pulmonary emboli resolution, no differences between groups were found in lung perfusion and gas exchange recovery at any time (from 1 day to 1 year) and in pulmonary artery pressure reduction at 1 week. The greater angiographic and scintigraphic recovery observed with urokinase, versus heparin alone, after 1 day of treatment in the Urokinase Pulmonary Embolism Trial may be ascribed to a synergistic effect with urokinase of heparin administered during the diagnostic work-out. The indications of heparin and urokinase should be evaluated in the light of these results.

Acute Disease↗

PAF-induced histamine release in the isolated perfused rat kidney.

The platelet-activating factor (PAF) has been shown to stimulate the release of prostaglandins, leukotrienes and 5HT from a number of cell types. In this work we studied the effects of bolus injections of PAF on the isolated perfused rat kidney. Results showed histological damage at the proximal-tubule level and a significant histamine release.

Animals↗

Renal tolerance of rubidium chloride: short-term clinical evaluation.

The rubidium and lithium ions are known to have opposite effects on a wide range of biochemical and behavioral parameters in experimental animals. Based on the proven effectiveness of lithium as an antimanic agent, several trials have been conducted with rubidium in the acute treatment of the depressive phase of bipolar illness. The results to date are promising. However, the 30- to 60-day biologic half-life of rubidium has mandated careful studies of potential toxicity before engaging in long-term administration of this ion to depressive subjects. One area of potential concern is the possibility of renal toxicity, which could be expressed as unexpectedly increased retention of rubidium. The data in this paper show that after 15 days of rubidium administration, there are no changes beyond the normal range in a variety of kidney function tests, including in four enzymes which are specific markers of tubule cell function.

Aged↗

Histological changes and histamine release induced by dactimicin in isolated perfused rat kidney.

The nephrotoxicity of aminoglycosides has been the object of numerous works of research showing that different molecules belonging to the same family of antibiotics can exert their toxic action in different ways. The aim of the present research was to evaluate the nephrotoxicity of dactimicin (DTC), a recently synthesized aminoglycoside antibiotic, as compared to gentamicin (GTM), amikacin (AMK) and fortimicin (FTM). The experimental model used was the isolated perfused rat kidney, and the parameters evaluated were histamine release and histological findings. The results showed that GTM was able to induce a significantly higher release of histamine than AMK, FTM, or DTC. AMK provoked a higher level of histamine release than FTM or DTC, although the differences between the three were not significant. Histological preparations obtained with GTM revealed large-scale lesions, which however were less detectable with AMK, and much less with DTC.

Aminoglycosides↗

Comparative effects of gentamicin, amikacin and dactimicin on excretion of N-acetyl-beta-D-glucosaminidase (NAG) and kidney histological pattern in rats.

Dactimicin (DC) is a new pseudodisaccharide aminoglycoside antibiotic containing a formimidoyl group in its molecule (1). DC exhibits a greater antibacterial activity than other aminoglycosides against the clinical isolates of Serratia marcescens and is active against many gentamicin- and amikacin-resistant bacteria. This characteristic of the drug appears to be linked with a probable protective action exerted by the formimidoyl group in its structure. The greatest limitation in the clinical use of aminoglycosides is their potential for nephrotoxicity. The present study compares the renal effects of DC versus gentamicin (GT) and amikacin (AK), respectively the most and the least nephrotoxic pseudotrisaccharide aminoglycosides in present use (2), evaluating the urinary NAG excretion and the histological changes induced in the kidney.

Acetylglucosaminidase↗

[Lithium and the kidney. Acute effects on ADH secretion and enzymuria].

The short-term (30 days) effects of lithium carbonate on ADH secretion, urinary enzyme secretion (specific markers of tubular damage), fractional excretion of sodium, calcaemia, calciuria and fractional reabsorption of phosphate, plasma and urinary Ca, urea and creatinine clearance were assessed in 15 female patients with emotional disorders. An immediate increase in diuresis was noted. At least in the acute initial phase, this phenomenon appears to be caused by inhibited ADH incretion. No significant variation were noted in calciuria or the fraction of sodium secretion but there was a significant increase of enzymuria, confirming the potential nephrotoxicity of lithium treatment.

Adult↗

Enzymuria in aminoglycoside-induced kidney damage. Comparative study of gentamicin, amikacin, sisomicin and netilmicin.

Forty-one patients with urinary tract infections were randomly assigned to receive for six days gentamicin, amikacin, sisomicin or netilmicin. The dose for each patient was calculated according to creatinine clearance and lean body mass in order to avoid overdosages. Urinary enzymes (alpha-glucosidase, gamma-glutamyltranspeptidase and muramidase), serum creatinine and creatinine clearance, proteinuria and urinary sediment were evaluated for nephrotoxicity. None of the patients developed nephrotoxicity, but urinary enzymes rose significantly in all. The statistical analysis of enzymuria during the treatment permitted the definition of a rank order of the nephrotoxic potential of the aminoglycosides studied.

Adolescent↗