Exercise supplementation to dipyridamole prevents hypotension, improves electrocardiogram sensitivity, and increases heart-to-liver activity ratio on Tc-99m sestamibi imaging.

BACKGROUND: Myocardial perfusion imaging with dipyridamole is an alternative with which to evaluate patients who are unable to exercise. Many patients who undergo dipyridamole testing are limited in their ability, but are not completely unable, to exercise. There are benefits from adding low workload exercise to dipyridamole testing, including a reduction of thallium 201 concentration in the liver, leading to a higher heart-to-liver activity ratio and better image quality. This prospective study was designed to evaluate a protocol of exercise supplementation during dipyridamole technetium 99m sestamibi imaging and to verify whether a higher heart-to-liver activity ratio could be obtained. We also evaluated the potential of this combined protocol to prevent hypotension and induce ischemic changes on the electrocardiogram (ECG). METHODS AND RESULTS: Ninety consecutive patients who were not completely disabled for exercise underwent dipyridamole Tc-99m sestamibi cardiac single photon emission computed tomography with a protocol of exercise supplementation (DipEx). The heart-to-liver activity ratio, hemodynamics, and electrocardiographic changes were studied. The findings were compared with those of a control group (Dip) composed of 99 patients who underwent dipyridamole infusion alone. Patients with left bundle branch block, pacemaker, and atrial fibrillation were excluded. The DipEx patients tolerated the protocol, exercising 4.2 +/- 1.3 minutes on the treadmill (Bruce protocol). Compared with Dip, patients in the DipEx group had a higher heart-to-liver activity ratio (1.3 +/- 0.4 vs 1.6 +/- 0.5, respectively; P =.00001), had no incidence of hypotension (6% vs 0%, respectively; P =.03), and had a higher sensitivity of the ECG to detect ischemia (6% vs 34%, respectively; P =.003). The increase in sensitivity seen in the DipEx group was accompanied by a significant decrease in specificity compared with the Dip group (67% vs 100%, P =.000001). CONCLUSIONS: Our data show that the addition of limited exercise to dipyridamole results in benefits during Tc-99m sestamibi imaging, increasing heart-to-liver activity ratio, preventing vasodilator-induced hypotension, and improving ECG sensitivity for the detection of ischemia. Furthermore, this protocol also provides an estimation of the patient's physical capacity and could be used as an alternative for patients undergoing dipyridamole infusion who are not completely unable to exercise.

[Morbidity and mortality in patients undergoing dialysis. Comparison of hemodialysis and peritoneal dialysis. Our experience]. / Morbilità e mortalità in pazienti in dialisi. Confronto fra emodialisi e dialisi peritoneale. Nostra esperienza.

BACKGROUND: We have compared the hemodialysis and peritoneal dialysis populations of our Center for morbidity and mortality, in a retrospective study of six years of activity. METHODS: We enrolled 125 patients (104 patients/year/million inhabitants), who had been in chronic dialysis from 1992 to 1997: 90 (22-90 years old) initiated in hemodialysis and 35 (27-82 years old) in peritoneal dialysis. RESULTS: We have evaluated survival and morbility, as hospitalization/patient/year in both groups. Mortality did not prove significantly different in the two groups. The global average of hospitalization was 8 days/patient/year for hemodialysis and 6 for peritoneal dialysis. CONCLUSIONS: In spite of the short time of observation and the exiguity of numbers, our experience shows that the two methods are equivalent.

[Prevalence of anti-HCV antibody positivity and seroconversion incidence in hemodialysis patients]. / Prevalenza di positività per anticorpi antiHCV e incidenza di sieroconversione in pazienti in emodialisi.

BACKGROUND AND AIMS: The prevalence of positivity to anti-HCV antibodies and the incidence of seroconversion in a group of patients undergoing replacement hemodialytic treatment was evaluated using a retrospective analysis. The study was carried out in a hemodialysis centre with no areas and/or equipment dedicated to patients positive to anti-HCV antibodies. The aim was to check whether the rigid application of universal aseptic precautions, which are always adopted by the centre, are sufficient to prevent contagion by hepatitis C virus in patients undergoing dialysis. METHODS: The study was carried out in patients receiving dialysis in the Centre (74 patients at the start of the observation period) for two years (7/95-7/97). Anti-HCV antibodies were assayed every two months using a third generation ELISA tests and positive results were confirmed by RIBA III test. At the start of the observation period, 10/74 patients showed positive levels of anti-HCV antibodies (13.5%). RESULTS: During the period in question none of the patients with negative levels of anti-HCV antibodies at the start of the study became positive. Of the patients undergoing dialysis after 1/7/95, four were already positive for anti-HCV antibodies and none of the others became positive. CONCLUSIONS: The experience confirms that the application of universal aspeptic precautions may be sufficient to prevent the spread of hepatitis C virus in dialysis centres.

[Vascular access for hemodialysis under difficult conditions. Our experience]. / Accessi vascolari per emodialisi in condizioni difficili. Nostra esperienza.

Having examined the causes that lead, on the one hand, to an increased number of vascular accesses in difficult conditions and, on the other, to their reduction and having examined their personal series of vascular accesses for hemodialysis studied between 4 December 1974 to 30 September 1996, and lastly having outlined the correct protocol for the preparation of these accesses, the authors focus on vascular accesses created in difficult conditions, namely the exhaustion of the natural venous and/or arterial bed below the proximal third of the upper limb. In particular, they examine the use of definitive jugular catheters, a more recent and therefore non-standardised method, and conclude that, although not regarded as vascular accesses of first choice, they should no longer be regarded as heroic but, after a short period of learning, they are easy to position and maintain.

[Treatment with erythropoietin and iron requirements in dialyzed patients]. / Trattamento con eritropoietina (Epo) e fabbisogno di ferro nel paziente dializzato.

The use of erythropoietin in dialysed patients leads to the gradual depletion of the body's iron reserves. It is important to assay iron blood levels in both patients receiving Epo therapy and those undergoing dialysis without this treatment. The most common method used is to assay ferritinemia, transferrinemia and the transferrin saturation levels. Using a retrospective study it was found that there is no significant difference in the request for iron supplementation in patients receiving Epo treatment compared to a control group not treated with Epo.

[Vascular access for hemodialysis. Our experience in 20 years]. / Accessi vascolari per emodialisi. Nostra esperienza in 20 anni.

A personal series arterio-venous fistulas from the last 20 years is examined. The authors have tried to verify the correctness of their present proctocol which is based on the abolition of those fistulas applied to the anatomic tabac. In fact in some cases they have caused problems of flow, but in other cases they have lasted much longer than any other kind of fistulas.

Kinetics of aluminoxamine and feroxamine chelates in dialysis patients.

To achieve a rational basis for the use of deferoxamine (DFO) in aluminum (AL) -and iron (Fe)-overloaded uremic patients, important insights may be provided by the recently available micromethods to determine DFO and its metallochelates aluminoxamine (AlA) and feroxamine (FeA). With this procedure, AlA and FeA plasma kinetics were evaluated in a pilot study in 10 uremic patients during a whole week after a single DFO infusion performed during the first hour of the first standard bicarbonate hemodialysis (HD) of the week. Patients were divided into normal (n = 6) and high (n = 4) ferritin groups (1 and 2 respectively). Baseline Al concentrations were greater than 2 less than 6 in group 1 and less than 1.5 mumol/l in group 2. DFO was given at doses of 40, 20 and 10 mg/kg. AlA and FeA showed substantially different kinetics. AlA kinetics were similar in group 1 and 2: they reached their peak at the beginning of the 2nd HD, decreased during the 2nd and 3rd HD, and with the highest DFO dose still increased between the 2nd and 3rd HD. At similar pre-DFO Al values (greater than 2 less than 3.3 mumol/l), increased DFO doses produced increased AlA concentrations ranging from 95 to 40% of total plasma Al for all the week. At higher pre-DFO Al values (greater than 3.5 less than 6 mumol/l), even a DFO dose as low as 10 mg/kg was sufficient to form consistent AlA amounts (from 80 to 15% of total Al).(ABSTRACT TRUNCATED AT 250 WORDS)

[Erythropoietin treatment in Piedmont and Valle d'Aosta]. / Il trattamento con eritropoietina in Piemonte e Valle d'Aosta.

The paper reports a study carried out in the Dialysis Centres of Piedmont and the Aosta Valley on the use of erythropoietin in the treatment of anemia in patients undergoing regular dialysis. The efficacy of the drug and collateral and/or undesirable effects were evaluated. It was found that the drug was efficacious in 99.2% of the 342 patients receiving treatment on 30-6-1990, whereas undesirable effects were observed in 14.6% of cases. Data from the Nephrology and Dialysis Service in Asti are also reported.

[Use of calcium carbonate as an intestinal chelator of phosphorus]. / Utilizzo del calcio carbonato (CaCO3) come chelante intestinale del fosforo.

Fourteen patients undergoing periodic dialysis who had been taking AL(OH)3 as an intestinal chelant of phosphorus have been examined. AL(OH)3 was replaced by CaCO3 for a period of 6 months. At the end of the study, statistically significant reductions were evidenced in alkaline phosphatase, basal serum aluminiaemia and its increase after Desferal test, while the bicarbonates (HCO3) were found to be increased. Statistically non-significant increases were observed in calcaemia, PTH, and pH. It is concluded that the replacement of AL(OH)3 with CaCO3 is effective in controlling phosphoraemia, in diminishing serum concentrations and tissue deposits of Al and in improving uraemic acidosis.

[Non-secreting myeloma]. / Il mieloma "non secernente".

On the basis of a personal observation, the cases of "non secretory" multiple myeloma reported in the literature are reviewed. A myeloma classification based upon the production and excretion of monoclonal proteins by neoplastic plasmacells is presented together with an evaluation of the different possible pathogenetic mechanisms. The diagnostic criteria of "non secretory" myeloma are discussed and its main clinical problems analyzed.

An approach to simultaneous immunofluorescent and autoradiographic analysis of human normal and neoplastic blood cells.

A technique for evaluating membrane immunofluorescence and isotope (3H-Thymidine, 3H-Uridine, 3H-Leucine) labelling in the same cell is described in detail. The possible interference of autoradiographic labelling on the fluorescent staining have been considered and found not to alter the final preparations. The technique proved valid both in normal and in neoplastic cells irrespective of their origin (peripheral blood, bone marrow, lymph node). Its possible extensions are finally discussed.