Doppler pulsato delle arterie arcuate intrarenali nel cane

RIASSUNTO Nel campo della medicina interna dei piccoli animali le patologie renali costituiscono una delle principali cause di mortalità. In medicina umana numerosi lavori hanno dimostrato che lo studio del rene attraverso la metodica doppler ad onda pulsata delle arterie arciformi e la conseguente determinazione dell’indice di resistività consente di ottenere delle informazioni utili per la diagnosi precoce di alcune nefropatie. Nonostante non tutti i processi patologici renali causino un’alterazione delle resistenze vascolari intrarenali o comunque producano un aumento rilevabile dell’indice di resistività, tale indice può risultare utile in corso di patologie renali acute e sindromi ostruttive. L’obiettivo di questo studio è di determinare il normale range di variabilità dell’indice di resistività in cani sani allo scopo di valutarne, in un secondo momento, le modificazioni in presenza di diverse nefropatie. Abbiamo ottenuto un valore medio di 0,61 (deviazione standard pari a 0,049) per il rene destro e di 0,60 per il rene sinistro (deviazione standard pari a 0,046). Non sono state riscontrate differenze significative in misurazioni seriali effettuate nello stesso rene, né tra i due reni di uno stesso soggetto mentre in soggetti diversi, sebbene sani, i valori dell’indice di resistività possono oscillare all’interno di un range piuttosto ampio. Inoltre non è stata riscontrata alcuna correlazione significativa tra l’età o il sesso del soggetto in esame ed il suo indice di resistività. SUMMARY In the field of small animal internal medicine renal diseases are among the most important causes of mortality. In human medicine several studies stated the usefulness of pulsed-wave doppler evaluation of renal arcuate arteries blood flow and subsequent determination of the resistivity index in early diagnosis of some nephropathies. Despite not all kinds of renal conditions alter intrarenal vascular resistance or cause a detectable modification of the resistivity index, such index may be valuable in presence of acute renal diseases or obstructive syndromes. The aim of this study is to determine the normal range of variability of the resistivity index in healthy dogs in order to assess, later, eventual modifications induced by different nephropathies. We obtained a mean resistivity index of 0.61(standard deviation is 0.049) in the right kidney and 0.60 (standard deviation is 0.046) in the left kidney. We did not find any differences among serial determinations of the resistivity index in the same kidney nor between the two kidneys of a given patient while among different patients, although healthy, the normal variability range is quite large. Furthermore we did not get any correlations between the age or sex of the dog and the resistivity index

MEDICAL SCIENCE. GISSI-2: A factorial randomised trial of alteplase versus streptokinase and heparin versus no heparin among 12 490 patients with acute myocardial infarction

A multicentre, randomised, open trial with a 2 x 2 factorial design was conducted to compare the benefits and risks of two thrombolytic agents, streptokinase (SK, 1\ub75 MU infused intravenously over 30-60 min) and alteplase (tPA, 100 mg infused intravenously over 3 h) in patients with acute myocardial infarction admitted to coronary care units within 6 h from onset of symptoms. The patients were also randomised to receive heparin (12 500 U subcutaneously twice daily until discharge from hospital, starting 12 h after beginning the tPA or SK infusion) or usual therapy. All patients without specific contraindications were given atenolol (5-10 mg iv) and aspirin (300-325 mg a day). The end-point of the study was the combined estimate of death plus severe left ventricular damage. 12 490 patients were randomised to four treatment groups (SK alone, SK plus heparin, tPA alone, tPA plus heparin). No specific differences between the two thrombolytic agents were detected as regards the combined end-point (tPA 23\ub71%; SK 22\ub75%; relative risk 1\ub704, 95% Cl 0\ub795-1\ub713), nor after the addition of heparin to the aspirin treatment (hep 22\ub77%, no hep 22\ub79%; RR 0\ub799, 95% Cl 0\ub791-1\ub708). The outcome of patients allocated to the four treatment groups was similar with respect to baseline risk factors such as age, Killip class, hours from onset of symptoms, and site and type of infarct. The rates of major in-hospital cardiac complications (reinfarction, post-infarction angina) were also similar. The incidence of major bleeds was significantly higher in SK and heparin treated patients (respectively, tPA 0\ub75%, SK 1\ub70%, RR 0\ub757, 95% Cl 0\ub738-0\ub785; hep 1\ub70%, no hep 0\ub76%, RR 1\ub764, 95% Cl 1\ub709-2\ub745), whereas the overall incidence of stroke was similar in all groups. SK and tPA appear equally effective and safe for use in routine conditions of care, in all infarct patients who have no contraindications, with or without post-thrombolytic heparin treatment. The 8\ub78% hospital mortality of the study population (compared with approximately 13% in the control cohort of the GISSI-1 trial) indicates the beneficial impact of the proven acute treatments for AMI. \ua9 1990