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Biomedical subjects

L Pedrini

Publications and source records attributed to L Pedrini.

At least 55 records · Page 3Linked to original sources
PubMed1986

Long-term prognosis after carotid endarterectomy.

This study analyzed 76 consecutive patients with carotid transient ischemic attacks (TIA) and carotid lesions appropriate to symptoms who underwent endarterectomy during the period 1975-1981. The mean age of the patients was 51.9 +/- 8 years at the time of surgery. Hypertension was present in 32.9%, diabetes mellitus in 13%, ischemic cardiopathy in 8.2% and peripheral vascular disease in 6.6%. Operative mortality was 1.3% and harder morbidity 4%. The average follow-up was 2.6 years (range 1-7 years). The observed 5-year survival rate was 85.2% compared to the expected rate of 92.4% in a normal population. During the follow-up 5 patients had a stroke: the cumulative stroke rate was 4.6% at 1 year and 7.9% at 3 years. 18 patients had further TIAs (13 carotid TIAs and 5 vertebro-basilar TIAs). 6 patients suffered myocardial infarction. The prognosis of TIA patients treated with endarterectomy is difficult to evaluate because the natural history of TIAs is still undefined.

Actuarial Analysis↗
PubMed1984

Sodium kinetics across dialysis membranes.

The kinetics of sodium across dialysis membranes were studied during diffusion and during convection utilizing cuprophan and cellulose hydrate membranes. During diffusion the changes in plasma water sodium concentration are correlated to the sodium concentration gradient between plasma water and dialysate but an increase also occurs when the gradient is annulled, due to the Donnan effect. During convection the plasma water sodium concentration increases during the passage through the dialyzer and the ultrafiltrate sodium concentration is significantly lower than the plasma water sodium concentration; this is due to the fact that the plasma proteins, as anions unable to cross the membrane, affect the kinetics of the sodium cations. Therefore, during diffusion the kinetics of sodium are mainly affected by the sodium concentration gradient and by the plasma protein concentration, while during convection the plasma protein concentration is the main factor affecting the kinetics of sodium.

Body Water↗
PubMed1982

"Physiological" and "pharmacological" dialysate sodium concentrations.

Forty three uremic patients on regular hemodialysis treatment (4 hours 3 times/week) were dialyzed for a period of 28.95 +/- 14.46 months with a dialysate sodium concentration (NaD) of 142 mEq/l, similar to their plasma water sodium concentration corrected for the Donnan factor ("physiological" NaD). Blood pressure (BP) and body weight (BW) dropped significantly. During two following periods, lasting 18 and 14 months, with NaD 148 mEq/l, similar to the patients' plasma water sodium concentration ("pharmacologically high" NaD), cardiovascular stability improved and BP did not show significant increase. Using "physiological" and "pharmacologically high" NaD the removal of water and sodium by convection improves the cardiovascular stability and the patients' well being, without bringing about the feared long-term cardiovascular side effects, if an appropriate dry body weight is achieved, because of better correction of the cellular overhydration.

Blood Pressure↗
PubMed1981

Long-term haemodialysis treatment with sodium removal by convection.

Forty-three uraemic patients were studied for 60.95 +/- 14.46 months of haemodialytic treatment (4 hours, 3 times/week). After a first dialysis period of 28.95 +/- 14.46 months with a dialysate sodium concentration (NaD) of 142 mEq/L blood pressure (BP) and body weight (BW) showed values significantly lower (p less than 0.001). During a following period of 32 months with NaD 148mEq/L BP did not show significant changes. A more 'physiological' removal of water and sodium by convection does not bring about the feared long term cardiovascular side effects if an appropriate dry BW is achieved, probably because of better correction of the cellular overhydration.

Adult↗
PubMed1980

Steroid pulses and plasmapheresis in the treatment of acute renal failure in multiple myeloma.

Four patients with acute renal failure due to myeloma (IgG with lambda, lambda, lambda, IgG with kappa) were studied; serum creatinine was 4.7, 5.9, 4.25, 10.8 mg%, and proteinuria 2.1, 2.8, 5.2, 4.2g/24h respectively. Renal biopsy specimens (3 patients) showed interstitial fibrosis, oedema, infiltration of mononuclear cells, tubular atrophy or dilatation with many 'myeloma kidney' casts. The patients were treated with plasmapheresis (2-4 exchanges) and methylprednisolone pulses (three to four 1g pulses). Maintenance therapy included prednisone, vincristine, melphalan and cyclophosphamide. After a follow up of 26, 17, 8, 6 months respectively, serum creatinine levels are 1.7, 2.4, 1.8, 4.2mg% respectively. Proteinuria disappeared after three months of therapy in 3 patients, and then remained absent for the successive follow up.

Acute Kidney Injury↗
PubMed1979

Multicentre comparative trial of tienilic acid and hydrochlorothiazide in hypertensive patients.

To compare the clinical and metabolic effects of a new diuretic uricosuric agent, tienilic acid, with those of hydrochlorothiazide, a multicentre double-blind trial was performed in 56 hypertensive patients. Twenty-eight patients were randomly assigned to take tienilic acid and 28 to take hydrochlorothiazide. The diuretic and anti-hypertensive actions of the two compounds were similar. No significant differences were observed between tienilic acid and hydrochlorothiazide in their effects on urinary and serum electrolytes, hepatic and renal function tests, and fasting lipids. The patients who received tienilic acid showed a significant fall in serum uric acid, mediated by the uricosuric effect. The availability of an agent combining diuretic, antihypertensive and hypouricemic effects offers promise in the treatment of arterial hypertension.

Adolescent↗
PubMed1978

Ultrafiltration and high sodium concentration dialysis: pathophysiological correlation.

Five stabilised uraemic patients underwent two different procedures using the Gambro Ultradiffuser: ultrafiltration alone for one hour (mean body weight loss 2.97 +/- 0.24 kg) and ultrafiltration with simultaneous dialysis for one hour (mean body weight loss 2.92 +/- 0.22 kg) using a given dialysate sodium concentration which reproduced the changes in osmolality which occur during ultrafiltration alone. This mean sodium concentration was 154.75 +/- 2.02 mEq/L. The results did not show significant differences for the two procedures as regards tolerance to dehydration. These results underline the key role of osmolar stability in making dehydration tolerable.

Blood Pressure↗
PubMedDate not supplied

Noninvasive localization of human atherosclerotic lesions with indium 111-labeled monoclonal Z2D3 antibody specific for proliferating smooth muscle cells.

BACKGROUND: Targeting exclusive antigens in atherosclerotic plaques with antibodies may provide a noninvasive means to detect rapidly proliferative atherosclerotic lesions. 111In-labeled negative charge-modified Z2D3 F(ab')2 (Z2D3) specific for an antigen expressed exclusively by proliferating smooth muscle cells has been shown to accumulate in rabbit atherosclerotic plaques. METHODS: The safety, biodistribution, accumulation, and elimination of Z2D3 were assessed in 11 patients who were candidates for carotid endarterectomy. The presence of atheromas in these patients was confirmed by angiography and Doppler ultrasound. Z2D3 (250 microg) labeled with 5 mCi of 111In was administered by slow intravenous injection. Planar and single photon emission computed tomography (SPECT) images were obtained 4, 24, 48, and 72 hours later. Carotid endarterectomy was performed and the surgical specimens were imaged, weighed, gamma-counted, and analyzed by immunostaining. RESULTS: Uptake of Z2D3 at the site of the carotid plaques was observed in the planar and SPECT views at 4 hours in all subjects. In addition, antibody uptake was noted in the contralateral vessel in 5 subjects. SPECT images identified the atherosclerotic plaques with focal uptake. The antibody uptake corresponded with the angiographic location of the disease. Immunohistochemical studies of the endarterectomy specimens confirmed the localization of Z2D3 into the plaque areas containing smooth muscle cells. Adverse drug reactions were not observed. CONCLUSION: This study demonstrates the feasibility of targeting atherosclerotic lesions with negative charge-modified antibody. It also proposes the possibility of selective identification of various components of atherosclerotic plaque, which may contribute to determining strategies of intervention in future.

Aged↗
PubMedDate not supplied

[The functional effect of internal carotid TEA on ocular hemodynamics].

Fifteen patients with a stenosis of the internal carotid artery superior than a 70% were studied in order to analyze the effects of TEA on the ocular hemodynamics. Analysis was made by ophthalmodynamography and electrofunctional studies. An improvement of the ocular hemodynamics was found, particularly by ophthalmodynamography and visual evoked potentials.

Aged↗
PubMedDate not supplied

Cerebral SPECT with 99mTc-HMPAO in extracranial carotid pathology: evaluation of changes in the ischemic area after carotid endarterectomy.

The authors report their experience in studying patients undergoing carotid endarterectomy with simple photon emission computed tomography (SPECT). This technique made it possible to identify areas of preoperative cerebral hypoperfusion in 54.8% of the patients which had a good correlation with neurological symptoms. To distinguish gradual changes in the ischemic lesions, a method of assessing the surface of the hypoperfused areas was adopted. In addition, SPECT made it possible to detect a greater number of hypoperfused areas even in sites other than those revealed by CT. Moreover, there was good correlations between the SPECT data and the grade and site of the carotid lesion and the data provided by some intraoperative monitoring procedures. The Authors therefore propose the use of SPECT in the evaluation of patients with cerebrovascular insufficiency following a carotid disease.

Adult↗
PubMedDate not supplied

[Italian study on the treatment of anaemia in chronic dialysis patients switched over to less frequent doses of darbepoetin from human recombinant erythropoietin (rHuEPO)].

BACKGROUND: Darbepoetin alpha is a novel erythropoiesis stimulating protein with unique properties as compared to recombinant human erythropoietin (rHuEPO), including a three-fold longer elimination half-life that allows for less frequent dosing. This study was aimed at testing the efficacy and safety of darbepoetin alpha in a large number of chronic dialysis patients switched from rHuEPO. METHODS: Nine hundred and fifty dialysis patients in stable treatment with rHuEPO were switched to darbepoetin alpha. Patients receiving rHuEPO 2 or 3 times weekly were switched to once weekly darbepoetin alpha and those receiving rHuEPO once weekly were switched to once every other week darbepoetin alpha. Patients received darbepoetin alpha by the same route of administration (SC or IV) as the one used for rHuEPO. The unit doses of darbepoetin alpha (10-150 microg) were titrated to maintain haemoglobin concentration within -1.0 and +1.5 g/dL of the individual mean baseline haemoglobin levels and between 10 and 13 g/dL for 24 weeks. RESULTS: The mean change in haemoglobin from baseline to the evaluation period (weeks 21-24) was statistically but not clinically significant [-0.10 g/dL (95% CI: -0.18, -0.02]. In general, the geometric mean weekly dose of study drug from screening/baseline to evaluation period remained substantially unmodified [(from 26.10 micro g/wk to 25.90 microg/wk; percentage change -0.40% (95% CI: -3.78, 3.10)]. Overall, darbepoetin alpha was well tolerated. CONCLUSIONS: The treatment of anaemia of a large dialysis patient population with unit dosing of darbepoetin alpha is effective and safe in maintaining target haemoglobin concentration at reduced dose frequency.

Anemia↗
PubMedDate not supplied

[Guidelines on water and solutions for dialysis. Italian Society of Nephrology].

The National Society of Nephrology has promoted the development of specific Italian Guidelines for dialysis fluids. Two previous national inquiries showed a wide variety in the type and frequency of both microbiological and chemical controls concerning dialysis water, reinforcing the need for specific standards and recommendations. An optimal water treatment system should include tap water pre-treatment and a double reverse osmosis process. Every component of the system, including the delivery of the treated water to the dialysis machines, should prevent microbiological contamination of the fluid. Regular chemical and microbiological tests and regular disinfection of the system are necessary. 1. Chemical quality (Table: see text). Treated tap water used to prepare dialysis fluid should be within European Pharmacopoeia limits at the water treatment system inlet and at the reverse osmosis outlet. In addition dialysate, concentrate and infusion fluids must comply with specific Pharmacopoeia limits. The physician in charge of the dialysis unit is advised to institute a multidisciplinary team to evaluate the requirement for added chemical controls in the presence of local hazards. 2. Microbiological quality (Table: see text). High microbiological purity of dialysis fluid--regularly verified--is a fundamental prerequisite for dialysis quality and every dialysis unit should aim as a matter of course to obtain "ultra-pure" dialysate (microbial count <0.1 UFC/mL, endotoxins <0.03 U/mL). On-line dialysate ultrafiltration and regular disinfection of dialysis machines greatly enhance microbiological purity. On-line dialysate reinfusion requires specific devices used according to corresponding instructions and to more frequent microbiological tests. Dialysis fluids for home dialysis should comply with the same chemical and bacteriological quality. The appendix reports the water treatment system's technical characteristics, sampling and analytical methods, monitoring time-tables, as well as the origin and effects of the main toxic substances. Suggestions and questions concerning these guidelines are welcome to nefrologia@sin-italy.org.

Colony Count, Microbial↗