Dobutamine stress echocardiography early after myocardial infarction treated with thrombolysis. Identification of myocardial viability and ischemia and relation to spontaneous functional recovery

The aim of the study was to assess the ability of dobutamine stress echocardiography to detect myocardial viability and ischemia in patients with acute myocardial infarction treated with thrombolysis and to correlate the acute response to dobutamine with late spontaneous functional recovery at follow-up. Forty-two consecutive patients with myocardial infarction treated with thrombolysis underwent low- (5 and 10 mcg/kg/min) and high-dose (20 to 40 mcg/kg/min) dobutamine stress echocardiography at a mean of 7 +/- 3 days of the acute phase. A follow-up 2D-echocardiogram was performed in all patients to evaluate the spontaneous recovery of function in the infarct area. On the basis of the response to the test, 3 groups of patients were identified: group 1 included 7 patients showing an improvement in left ventricular asynergy score index at low doses (from 1.5 +/- 0.3 to 1.3 +/- 0.2, p < 0.05) with no deterioration at high doses, indicative of myocardial viability without ischemia; group 2 (23 patients) showed a significant improvement in the asynergy index at low doses (from 1.58 +/- 0.3 to 1.32 +/- 0.32, p < 0.05) followed by a deterioration at high doses (1.68 +/- 0.4, p < 0.05 vs low-dose), suggestive of residual myocardial ischemia in the infarct zone; group 3 included 12 patients who showed no significant changes in the baseline asynergy score index (1.67 +/- 0.2) either at low or at high doses. The acute response to dobutamine stress echocardiography accurately predicted the spontaneous recovery of function in the infarct area at follow-up: both group 1 and group 2 patients showed a significant reduction in the asynergy score index (group 1: 1.16 +/- 0.3 vs 1.5 +/- 0.2, p < 0.001; group 2: 1.43 +/- 0.3 vs 1.58 +/- 0.3, p < 0.05), while group 3 had no recovery in the asynergy index (1.67 +/- 0.2 vs 1.67 +/- 0.2). Thus, in patients with acute myocardial infarction treated with thrombolysis dobutamine stress echocardiography can detect myocardial viability in 71% and ischemia in the infarct zone in 55% of patients; moreover, the response to the test during the acute phase is correlated with the degree of the late spontaneous recovery of function in the infarct area.

Posatirelin in the treatment of vascular dementia: a double-blind multicentre study vs placebo

INTRODUCTION

The usefulness of posatirelin (L-pyro-2-aminoadipyl-L-leucyl-L-prolinamide), a synthetic peptide having modulatory activity on the monoaminergic and cholinergic systems and neurotrophic effects, was evaluated in vascular dementia.

PATIENTS AND METHODS

A multicentre, parallel groups, double-blind clinical study vs placebo was carried out with patients suffering from probable vascular dementia according to the NINDS-AIREN criteria. The study consisted of a two-week run-in of a once daily, orally administered, placebo phase, followed by 12 weeks of intramuscular treatment with posatirelin 10 mg/ml or placebo given once a day and a follow-up after one month's withdrawal. Efficacy was assessed using the Gottfries-Bråne-Steen (GBS) Rating Scale for dementia, the Randt Memory Test and the Toulouse-Piéron Attention Test. Data were evaluated using analysis of variance and covariance.

RESULTS

As regards GBS scores, patients treated with posatirelin showed a significant improvement in intellectual performance, in orientation, motivation and memory as compared to controls. The improvement of memory performance was also confirmed by the acquisition score and memory index of the Randt Memory Test. At the end of the follow-up period the differences between treatments were still maintained. Tolerability was good.

CONCLUSIONS

The significant improvement observed in cognitive functions, attention and motivation of demented patients treated with posatirelin suggests the potential usefulness of this drug in vascular dementia. Furthermore, the presence of a long-lasting effect after drug withdrawal suggests the possibility of administering the drug cyclically.

Thrombin activity and early outcome in unstable angina pectoris

BACKGROUND

The blood coagulation system is frequently activated in the acute phase of unstable angina, but it is unknown whether the augmented function of the hemostatic mechanism may serve as a marker of increased risk for an early unfavorable outcome.

METHODS AND RESULTS

Plasma concentrations and 24-hour urinary excretion of fibrinopeptide A were prospectively determined in 150 patients with unstable angina. All patients underwent 24-hour Holter monitoring, during which time urine was collected; at the end of this period, a blood sample was taken and coronary arteriography was performed. The patients were followed up for the occurrence of cardiac events (death and myocardial infarction) until they underwent coronary revascularization or until they were discharged from the hospital. Fibrinopeptide A plasma levels and 24-hour urinary excretion were found to be abnormally elevated in 50% and 45% of the study population, respectively. During hospitalization, 11 patients developed myocardial infarction and 2 patients died. Kaplan-Meier analysis demonstrated a significantly higher probability of developing cardiac events in patients with abnormal rather than normal plasma levels of fibrinopeptide A (P<.01), whereas no difference in outcome was observed between patients with normal and those with abnormal 24-hour urinary excretion. Cox regression analysis showed that the only variables independently related to an early unfavorable outcome were the presence of persistent ischemia during 24-hour Holter monitoring (P<.0001), the presence of intracoronary thrombosis at angiography (P=.016), and abnormal fibrinopeptide A plasma levels (P=.038).

CONCLUSIONS

Patients with unstable angina pectoris and abnormal fibrinopeptide A plasma levels are at increased risk for an early unfavorable outcome.

Comparison of dobutamine stress echocardiography with dipyridamole stress echocardiography for detection of viable myocardium after myocardial infarction treated with thrombolysis

OBJECTIVE

To compare the ability of dobutamine and dipyridamole stress echocardiography to detect functional recovery of stunned but viable myocardial regions early after acute myocardial infarction, and to predict late functional recovery of the reperfusion salvaged myocardium within the infarct area.

METHODS

Within 10 d of acute myocardial infarction, 51 patients--30 anterior and 21 inferior, 44 Q wave and seven non-Q-wave infarction--were submitted to a dobutamine echocardiography test at low dose (5-10 micrograms/kg/min over 5 min) and high dose (20-40 micrograms/kg/min over 3 min) and to dipyridamole echocardiography test (0.56 mg/kg over 4 min + 0.28 mg/kg over 2 min) on different days and in random order, after interruption of any vasoactive drug. Resting echocardiography was repeated at two months in 41 of 51 patients (80%). Regional wall motion of the left ventricle was analysed in a semiquantitative manner on a 14-segment model. Viability was defined as improvement of one grade or more of at least two basally asynergic segments in the infarcted area.

RESULTS

Regional functional recovery was detected by low dose dobutamine in 38/51 patients (75%) and in 147/308 (48%) of basally asynergic segments, compared to 25/51 patients (49%; P < 0.001) and 78/308 segments (25%; P < 0.001) only identified by dipyridamole. Late spontaneous functional recovery was detected in 24/41 patients (59%) and in 78/254 basally asynergic segments (31%). The sensitivity of dobutamine and dipyridamole echocardiography for predicting spontaneous functional recovery was 72% and 51% respectively (P < 0.001), specificity 68% and 82% (P < 0.001), positive predictive value 50% and 56%, and negative predictive value 85% and 79%.

CONCLUSIONS

In comparison with dipyridamole in patients with thrombolysed myocardial infarction, dobutamine induces regional functional recovery. This suggests that dobutamine is more sensitive in showing the presence of viable myocardium within the infarct zone, though it has a lower specificity in predicting delayed spontaneous functional recovery of non-contractile but still viable areas.

[Results and prognostic significance of echocardiography-dobutamine + atropine test in recent non-Q wave myocardial infarction]

BACKGROUND

Patients with non-Q wave myocardial infarction (NQ AMI) are usually considered to have an increased risk of recurrent ischemic events and reinfarction. We wished to assess whether dobutamine stress echocardiography with the addition of atropine (DOB-E + ATRO) can detect jeopardized myocardium after a recent NQ AMI and to assess the prognostic significance of this test in a group of patients with a first uncomplicated NQ AMI:

METHODS AND RESULTS

Fourty-one consecutive patients (38 men, mean age 52 +/- 9 years, 31 anterior, 68% treated with thrombolysis) underwent low and high-dose DOB-E (from 5 to 40 mcg/kg/min); ATRO was added in 14/41 (34%) patients. A significant deterioration of wall motion in the infarcted region (IR) indicative of residual myocardial ischemia was present in 36/41 patients (88%). Significant electrocardiographic changes and angina developed in 61% and 32% of patients, respectively. Coronary angiography was performed in 30/41 patients (73%) and showed 1-vessel coronary artery disease (CAD) in 70% of cases, multivessel CAD in 23% of cases and no significant CAD in 7% of patients. Three patients were lost at follow-up and 10 other patients were excluded from the analysis because a revascularization procedure was performed during diagnostic angiography. On a mean follow-up period of 9.5 +/- 9 months, the incidence of coronary events (re-infarction, recurrent angina, revascularization procedures) was higher (15/36 vs 1/5, 42% vs 20%) in patients with a DOB-E + ATRO positive test (1 reinfarction, 9 recurrent angina, 5 revascularized) than in those with a negative test (1 recurrent angina).

CONCLUSIONS

DOB-E + ATRO early after a first uncomplicated NQ AMI documents the presence of myocardial ischemia in the IR in the great majority of patients. A positive DOB-E + ATRO was found to be associated with a higher incidence of cardiac events at follow-up, but the results of this non prospective study (high sensitivity but low specificity and predictive value for cardiac events at follow-up) suggest to utilize with caution this test for risk stratification of patients with recent NQ AMI until prospective and larger studies are performed.

Influence of gastric acid secretion blockade and food intake on the bioavailability of a potassium diclofenac suspension in healthy male volunteers

The bioavailability of a single dose of a potassium diclofenac (KDIC) suspension (Flogan, Merck, 7ml, 105 mg) was studied in 13 healthy male volunteers in the fasting state (placebo phase, PLA), after gastric acid secretion blockade (subacute pretreatment with omeprazole, OME phase) and after food intake (FOOD phase). A 14-day washout period between phases was adopted. Serum samples were obtained over a 24 hour interval and the diclofenac concentrations were determined by high pressure liquid chromatography with ultraviolet detection. From the serum diclofenac concentration vs time curves, the AUC[0-infinity] (area under the concentration vs time curves from 0 to infinity), Cmax (maximum achieved concentration), tmax (time to achieve Cmax), Ke (terminal first order elimination constant), half-life values (t1/2) and AUC[0-infinity]/t1/2 ratio as an index of diclofenac clearance, were obtained. All these variables were analyzed using both parametric and non-parametric statistics. In the presence of food, KDIC absorption was delayed (as shown by lower Cmax and greater tmax values) and decreased (as shown by lower AUC[0-infinity] values), and the serum diclofenac concentration vs time curves showed a biphasic pattern. Omeprazole pretreatment did not change the absorption parameters. Both of these treatments altered the diclofenac clearance, as assessed by the AUC[0-infinity]/t1/2, t1/2 and Ke values, although the changes were not considered to be clinically significant, because of the wide therapeutic range for diclofenac. The delay in the rate of diclofenac absorption produced by food intake was not due to an increase in the gastric pH, and could be of particular importance when rapid analgesia is desired.

Blood and serous cysts in the atrioventricular valves of the bovine heart

A survey of 30,907 slaughterhouse cattle (5,984 calves, 15,937 young adult, 8,986 cows) was carried out to determine the incidence of blood and serous cysts on atrioventricular valves. The cysts were classified by their content (blood/serous fluid), location (mitral/tricuspid valve), and size. Cyst wall samples were processed for histology, immunohistochemistry for factor VIII-related antigen, and transmission electron microscopy. The content of some cysts was studied by electrophoresis and biochemical and microbiologic methods. Older cows had a higher incidence (16.2%) than younger animals (11.5% in calves, 7.9% in steers, 6.4% in heifers), suggesting that the lesions may be acquired. Blood cysts were often present on both atrioventricular valves; serous cysts prevailed on the mitral valve. Cysts of both types were larger in older animals; serous cysts were larger than the blood cysts. Histologically, blood cysts contained fresh blood, and serous cysts were filled with a hyaline fluid devoid of cells, sterile, and biochemically similar to lymph. All the cysts were lined with endothelium, but a positive immunostaining for the factor VIII-related antigen was appreciable only in blood cysts. Ultrastructurally, the endothelium was composed of flat endothelial cells holding several cytoplasmic filaments, lying in blood cysts on a continuous and often laminated basal lamina with many cytoplasmic projections. The results support the hypothesis that cysts of the atrioventricular valves derive from the dilation of blood and lymphatic valvular vessels, do not regress with age, and are mainly the result of mechanical effects.

Neurotoxic effects of DSP-4 on the noradrenergic system of the goldfish brain

The substance N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) is a neurotoxin with selective and long-lasting effects on the noradrenergic (NA) neurons of mammalian brains. The present study examines the effects of this toxin on the noradrenergic system of the goldfish brain. Single doses (50 mg/kg body weight) of DSP-4 reduce the immunoreactivity of the NA synthesizing enzyme dopamine-beta-hydroxylase (DBH), as revealed by immunohistochemistry 7 and 12 days after toxin administration. The depletion involves the DBH-positive fibres and spares the DBH-positive cell bodies. Dopamine-beta-hydroxylase immunoreactivity, 40 days after toxin administration, showed a complete recovery. Ultrastructural investigations confirmed that DSP-4 toxicity affects only nervous fibres and terminals, sparing cell bodies. Administration of DSP-4 also produced a marked decrease of noradrenaline (NA) levels in the goldfish brain, seven days later, while dopamine (DA) and serotonin (5-HT) levels were unaffected by toxin injection. The reduction of NA levels induced by DSP-4 was prevented by the concomitant administration of the NA uptake inhibitor desipramine. Noradrenaline levels measured 40 days after toxin administration show that DSP-4 toxicity was completely reversed. The results suggest a pronounced plasticity of the noradrenergic system in the goldfish brain.

Results of dipyridamole plus atropine echo stress test for the diagnosis of coronary artery disease

Sensitivity of dipyridamole stress echocardiography (DIP-E) has been reported to be less than ideal in particular subsets of patients such as those with less severe extent of coronary artery disease (CAD). To verify if sensitivity could be improved, ATRO (1 mg in 2 minutes) was added at the end of a negative high-dose (0.84 mg/kg over 10 minutes) DIP-E in 61 consecutive patients (58 men, aged 53 +/- 7 years) evaluated for chest pain (33%) or for detection of residual ischemia after acute myocardial infarction (AMI) or previous MI (67%). DIP-E was positive in 28/61 (46%) and negative in 33/61 (54%) patients. Additional echo positivity was obtained in 18/33 (54%) patients after ATRO. Coronary arteriography was normal in 6 patients (10%); 1-vessel CAD was diagnosed in 28 (46%), 2-vessel CAD in 16 (26%) and 3-vessel CAD in 11 (18%) cases. The sensitivity for CAD diagnosis was 49% (27/55) for DIP-E and 84% (46/55) for DIP-E+ATRO (p < 0.001). Specificity was 83% and 80%, respectively. Diagnostic accuracy increased from 52% to 83% (p < 0.001). The better diagnostic accuracy of DIP-E was mainly related to the significant increase in sensitivity of the combined test in patients with 1-vessel CAD (from 46% to 75%) (p < 0.005). At quantitative coronary evaluation, compared to patients with positive DIP-E+ATRO or negative DIP-E+ATRO test, patients with positive DIP-E had a higher mean % diameter stenosis: 80 +/- 13% vs 72 +/- 24% and 65 +/- 36%, respectively. Peak heart rate was significantly higher after the addition of ATRO vs basal and DIP alone in patients with a positive DIP-E+ATRO test. The addition of ATRO to DIP increases diagnostic accuracy of DIP-E particularly in patients with less severe extent of CAD; ATRO may be considered as a useful routine procedure for increasing diagnostic value of DIP-E test.

Regional distribution of lesions in the central nervous system of cats infected with feline immunodeficiency virus

Neuropathological examination of the central nervous system of 13 naturally and 13 experimentally feline immunodeficiency virus (FIV)-infected cats revealed diffuse gliosis of gray and white matter and vacuolar myelinopathy in a large proportion of infected animals, sometimes associated with lymphocytic meningitis. Multinucleated giant cell formation, the hallmark of multifocal giant cell encephalitis in HIV infection, was never observed. Morphometric analysis confirmed a marked increase of GFAP reactivity in infected cats. Gliosis was mainly present in cortical structures of frontal, parietal, and occipital lobes. Only one naturally infected animal evidenced clinical symptoms of neurological damage. This study confirms that FIV provides an interesting model for studying HIV-induced cortical and subcortical brain pathology believed to be the cause of the neurological manifestations frequently observed in AIDS patients.

[Pleuroscopy and talc pleurodesis in recurrent pleural effusions: experience with 51 cases]

From January '92 up to January '94 thoracoscopy was performed in 51 patients with recurrent pleural effusion: 49 of these patients underwent talc pleurodesis. 10 pleural mesotheliomas, 29 diffuse metastasic pleural involvement and 12 benign effusions were diagnosed. Intrapleural talc therapy allowed a definitive pleurodesis in 43 patients with a success rate of 87%.

Circulating immune complexes and analysis of renal immune deposits in feline immunodeficiency virus-infected cats

Total immunoglobulin content and concentration of immune complexes (IC) were determined in the sera of 51 cats infected with feline immunodeficiency virus (FIV) and of 40 controls. IgG and IgM were quantified by radial immunodiffusion and circulating IC (CIC) by the CIC-conglutinin assay. IgG fractions were obtained by acid elution from kidney tissues of 15 FIV-infected and five negative control cats to investigate the possible role of IC in the genesis of renal damage observed in infected animals. Mean concentrations of IgG and circulating IC were higher in FIV-infected cats than in controls (29.6 +/- 6.7 versus 23.0 +/- 1.9 mg/dl (mean +/- s.d.) P < 0.001; and 66.5 +/- 17.0 versus 27.4 +/- 19.9% I, P < 0.001, respectively), while IgM levels were only slightly increased (0.9 +/- 0.05 versus 0.87 +/- 0.04 mg/dl, P < 0.02). Immunoglobulin fractions were eluted from 10 of the 15 renal tissue samples from FIV-infected cats and were found to be polyclonal and at least partly specific for FIV antigens. These findings confirm the presence of a B cell activation in FIV-infected cats and demonstrate the presence of high levels of CIC in their sera. The presence of immune deposits in renal tissues suggests that IC might play a role in the pathogenesis of the renal damage observed in FIV-infected cats.

Comparison between an enzyme-linked immunosorbent assay using a detergent-soluble Leishmania infantum antigen and indirect immunofluorescence for the diagnosis of canine leishmaniosis

Serum samples collected from 290 dogs--186 Leishmania-infected and 104 control animals--were screened to detect the presence of specific antibodies to Leishmania infantum antigens in Tuscany, Italy. Two different techniques were compared: an indirect immunofluorescence assay (IFA) and an indirect enzyme-linked immunosorbent assay (ELISA). The ELISA was developed using a detergent-soluble antigen of L. infantum promastigotes. Triton X-100 and protease inhibitors were used as detergent and to increase reproducibility of the assay, respectively. A strong correlation between the anti-Leishmania antibody levels obtained by ELISA and those obtained using IFA was observed. The ELISA appeared to be somewhat more sensitive than IFA (99.5% vs. 98.4%), while its specificity was lower (97.1% vs. 100%), even if not significantly different. Immunoblotting analysis, using the detergent-soluble L. infantum antigen, demonstrated that proteins of M(r) 30 and 73 kDa were recognized by all positive sera, regardless of the serum titre. Furthermore, antigens of M(r) 16, 18, 26, 33, 50 and 117 kDa were also frequently reactive with a large proportion of sera from infected dogs. This ELISA demonstrated a high sensitivity and specificity as well as the IFA, and it seems to be a suitable assay for large scale epidemiological studies.

Renal involvement in feline immunodeficiency virus infection: p24 antigen detection, virus isolation and PCR analysis

Renal alterations characterized morphologically by glomerular and tubulo-interstitial lesions and clinically by a heavy proteinuria and sometimes by renal failure are frequent in feline immunodeficiency virus (FIV) infected cats. To investigate the possible role of local FIV replication in the genesis of this renal damage, renal tissues of 15 consecutive naturally infected and five non-infected cats were examined for traces of the virus by immunohistochemistry, using a monoclonal anti-p24 antibody in a streptavidin-biotin peroxidase labeled system, cultivation and polymerase chain reaction (PCR). Tubular epithelial cells as well as scattered interstitial inflammatory and glomerular cells were positive for p24 antigen in 13 cats. Viral isolation was successful in seven cats, and FIV gag DNA and RNA sequences were detected in 14 and five cats, respectively. Control cats were constantly negative. Although not conclusive, these results suggest that a direct role of FIV in the induction of the renal damage observed in infected animals is possible.

Biochemical and pharmacological evidence for the presence of A1 but not A2a adenosine receptors in the brain of the low vertebrate teleost Carassius auratus (goldfish)

In whole brain membranes of goldfish, 3H-chlorocyclopentyladenosine bound to adenosine A1 receptors. The A1 receptors were ubiquitously distributed in the brain with a maximum in the hypothalamus and a minimum in the spinal cord. In superfused goldfish cerebellar slices, cyclohexyladenosine inhibited the cyclic AMP accumulation stimulated by forskolin and the selective adenosine A1 receptor antagonist, 8-cyclopentyltheophylline, reversed this effect. In the same brain preparation, 30 mM K+ stimulated the release of glutamate, glutamine, glycine and GABA in a Ca(2+)-dependent manner, whereas the aspartate and taurine release was Ca(2+)-independent. Cyclohexyladenosine, in a dose-dependent manner, inhibited the 30 mM K(+)-evoked release of glutamate whereas that of aspartate was unaffected. The CHA inhibition of glutamate-evoked release was reversed by 8-cyclopentyltheophylline. The adenosine A2a receptors were not detectable in whole brain membranes of goldfish either using the specific agonist 3H-CGS 21680 or 3H-5'-N-ethylcarboxamidoadenosine. The presence of A2b seems to be suggested by the NECA stimulation of cyclic AMP accumulation, which was reversed by 8-cyclopentyltheophylline. The results, taken together, indicate that adenosine has a neuromodulatory function in the nervous system of lower vertebrates which is comparable to that described in mammalian brain.

Determination of ticlopidine in human plasma by high-performance liquid chromatography and ultraviolet absorbance detection

A simple HPLC method has been developed for the determination of ticlopidine in human plasma. Plasma samples were buffered at pH 9 and extracted with n-heptane-isoamyl alcohol (98.5:1.5, v/v). Imipramine was used as internal standard. Chromatography was performed isocratically with acetonitrile-methanol-0.05 M KH2PO4 (20:25:55, v/v) at pH 3.0 containing 3% triethylamine at a flow-rate of 1 ml/min. A reversed-phase column, Supelcosil LC-8-DB, 15 cm x 4.6 mm I.D., 5 microns particle size, was used. The effluent was monitored by UV absorbance detection at 235 nm. The method showed good accuracy, precision and linearity in the concentration range 5-1200 ng/ml. The limit of quantitation was 5 ng/ml, with a precision (C.V.) of 8.91%, which is the same as that achieved by other authors with a previously published GC-MS method. The procedure described in this paper is simple and allows the routine assessment of ticlopidine plasma concentration in pharmacokinetic studies following therapeutic doses in human subjects.

[Tracheal resection-anastomosis in carcinoma of the thyroid infiltrating the airways. A case report]

The Authors report a case of thyroid carcinoma with tracheal involvement. Since the neoplastic invasion of the trachea was 3 cm long total thyroidectomy with sleeve tracheal resection and immediate reconstruction with end-to-end anastomosis were performed. The diagnostic and therapeutic approach is discussed and the Literature data reviewed.

[The side effects and safety of the echo-dobutamine test. The experience with 373 patients]

BACKGROUND

A potential limitation to the clinical utilization of dobutamine stress echocardiography is the higher incidence of side effects in respect to other noninvasive tests for the diagnosis of coronary artery disease reported by some authors. Due to the increased utilization of this test for the evaluation of chest pain and for prognostic stratification in patients with a recent myocardial infarction, we analyzed the results of 373 consecutive tests to evaluate the incidence and clinical significance of side effects induced by dobutamine.

METHODS

Dobutamine stress echocardiography was performed in 256 patients (69%) for the evaluation of chest pain; 85 out of 256 (33%) suffered from a previous myocardial infarction. 117 patients (31%) were studied in the early phase after an acute myocardial infarction for prognostic purposes. Dobutamine was infused starting with the dose of 5 gamma/kg/min over 3 minutes with incremental steps of 10-20-30-40 gamma/kg/min over 3 minutes under 2D-echocardiographic and 12-lead electrocardiographic monitoring.

RESULTS

In 95% of cases the test was stopped at the achievement of a target end point: wall motion abnormalities (60%), significant ECG changes (5%), 85% of the age-predicted maximal heart rate (13%), maximal dose (17%); only in 5% of cases a limiting side effect requiring a premature interruption of the test occurred: hypertension (systolic blood pressure over 240 mm Hg and/or diastolic over 120 mm Hg) (2%); symptomatic hypotension (0.5%); severe chest pain (1%); nausea (0.5%); cardiac arrhythmias (1%). Cardiac arrhythmias were the most frequently registered non limiting side effect. During the test 79 episodes of supraventricular arrhythmias and 211 episodes of ventricular arrhythmias occurred. Supraventricular arrhythmias consisted usually of benign sporadic premature beats; only 3 cases of self-limiting supraventricular tachycardia or atrial fibrillation were recorded. Sporadic ventricular premature beats were the most frequently recorded arrhythmias; 10 patients developed a ventricular tachycardia; however in no case this arrhythmia was sustained, associated with subjective symptoms and required the administration of a specific antiarrhythmic drug or the premature interruption of the test. Patients were divided according to the absence (Group 1, G1, n = 193, 52%) or the presence (Group 2, G2, n = 180, 48%) of cardiac arrhythmias during the test. Patients of G2 differed from patients of G1 only in respect of the maximal dose of dobutamine infused (33.5 vs 28.6 gamma/kg/min, p < 0.0005) and the incidence of a wall motion abnormality in the basal echocardiogram (66% vs 53%, p < .01). The second most recorded non limiting side effect (71/373 pts) (19%) was the occurrence of systolic hypotension, a drop of systolic blood pressure > or = 20 mm Hg in respect of the antecedent infusion step. In all cases no symptoms developed and the great majority of patients with this finding had a normal echocardiographic response to dobutamine at the time of his occurrence.

CONCLUSIONS

Dobutamine echo stress test is limited by the occurrence of significant side effects only in a minority of patients (5%); however in all cases, including complex ventricular arrhythmias, these side effects were self limiting and promptly recovered after interruption of the drug infusion. Non limiting side effects, in particular cardiac arrhythmias and systolic hypotension, are usually well tolerated and not associated with the occurrence of myocardial ischemia or left ventricular disfunction; thus, dobutamine echo stress test may be considered a safe test for the evaluation of the presence and severity of coronary artery disease both in patients with a previous or recent myocardial infarction and in patients without myocardial infarction.

Clinical assessment of mental decline in elderly people: a proposal for a new quantitative index

Despite the many instruments available for assessing elderly people, there is a need for additional methods to measure mental decline that would also be applicable in cross sectional and longitudinal studies. With this purpose in mind, our group developed and checked a new instrument, the Index of Mental Decline (IMD), which consists of five clusters of items intended for the assessment of cognition, personal interrelationships, affective disorders, apathy and somatic complaints. To improve its consistency, all clusters and items were evaluated individually, according to their clinical impact. Three levels of symptom importance were determined: absent to very mild, mild to moderate, severe to very severe. Inter-rater reliability and test-retest reliability were demonstrated in a sample of 59 subjects, and proved to be satisfactory. The validity of the IMD was tested in a group of 203 patients, in whom a clinical diagnosis of probable dementia (DSM III-R criteria) had been formulated. The results suggest the effectiveness of the IMD both in quantifying mental decline and monitoring clinical symptoms. The IMD cannot be the first step of diagnostic procedure, but it can be useful for evaluating mental decline in elderly subjects with cognitive disorders. In longitudinal studies, the presence of the same caregiver or informant is compulsory.

Adenosine analogs inhibit acetylcholine release and cyclic AMP synthesis in the guinea-pig superior cervical ganglion

The ability of adenosine agonists to modulate the electrically evoked release of acetylcholine (ACh) from [3H]choline preloaded guinea-pig superior cervical ganglia (SCG) was investigated. The adenosine A1-receptor selective agonist N6-cyclohexyladenosine (CHA) and 2-chloroadenosine (2-CADO) inhibited the evoked transmitter release, the effect being reversed by the A1-receptor selective antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), and by sulmazole (SUL), which blocks both the A1-receptor and the adenylate cyclase inhibitory regulator Gi. In whole ganglia, CHA decreased both the basal and the forskolin (FSK)-stimulated cyclic AMP synthesis. The latter effect was again prevented by the A1 antagonist DPCPX. These results are compatible with the existence, in the guinea-pig SCG, of adenosine A1-receptors, part of which are located on the presynaptic nerve terminals mediating an inhibition of ACh release.

Lentivirus infection in an African lion: a clinical, pathologic and virologic study

In May 1991, clinical, pathologic, and virologic investigations were carried out on an 8-yr-old male lion (Panthera leo), with recurrent infections, in captivity with two lionesses in the Zoological Garden of Pistoia, Tuscany, Italy. The lion had severe pneumonia, neutropenia, thrombocytopenia, and an increase in blood urea nitrogen and creatininemia; in spite of therapy, it died within 3 months. At necropsy, the animal had a lymphoma and other lesions similar to those described in feline immunodeficiency virus-infected cats. We identified FIV gag-sequence using PCR amplification of lymph node tissues.

Feline immunodeficiency virus: an interesting model for AIDS studies and an important cat pathogen

The lentivirus feline immunodeficiency virus (FIV) is a widespread pathogen of the domestic cat that is mainly transmitted through bites, although other means of transmission are also possible. Its prevalence ranges from 1 to 10% in different cat populations throughout the world, thus representing a large reservoir of naturally infected animals. FIV resembles the human immunodeficiency virus (HIV) in many respects. Similarities include the structural features of the virion, the general organization and great variability of the genome, the life cycle in the infected host, and most importantly, the pathogenic potential. Infection is associated with laboratory signs of immunosuppression as well as with a large variety of superinfections, tumors, and neurological manifestations. Our understanding of FIV is steadily improving and is providing important clues to the pathogenesis of immunodeficiency-inducing lentiviruses. The cellular receptor for FIV is different from the feline equivalent of the human CD4 molecule used by HIV; nevertheless, the major hallmark of infection is a progressive loss of CD4+ T lymphocytes as in HIV infection. The mechanisms by which FIV escapes the host's immune responses are being actively investigated. FIV causes lysis of infected T cells and also appears to predispose these cells to apoptosis. Infection of macrophages and other cell types has also been documented. For reasons yet to be understood, antibody-mediated neutralization of fresh FIV isolates is very inefficient both in vitro and in vivo. Vaccination studies have provided some encouraging results, but the difficulties encountered appear to match those met in HIV vaccine development. FIV susceptibility to antiviral agents is similar to that of HIV, thus providing a valuable system for in vivo preclinical evaluation of therapies. It is concluded that in many respects FIV is an ideal model for AIDS studies.

[Leiomyosarcoma of the inferior vena cava: description of a new case and review of the literature]

A case of primary leiomyosarcoma of the inter-renal vena cava is reported. This tumor is rare and up to date no more than 100 cases have been reported. Surgical treatment consisted in the removal of vena cava from the iliac veins to the suprahepatic veins with right nephrectomy. Restoration of vena cava and left renal vein continuity was not necessary because of the presence of collateral venous circulation at the time of operation. Venous ligation was haemodynamically well tolerated and the patient is disease-free at one year from operation. However, despite surgical radicality, prognosis remains poor given the frequency of metastases reported in more than 35% of cases.

[Adding atropine improves the diagnostic accuracy of dipyridamole-echo test]

BACKGROUND

The clinical experience with dipyridamole stress echocardiography for the diagnosis of coronary artery disease (CAD) revealed that patients with less severe extent of CAD and limited impairment of coronary reserve are frequently not recognized by the test. Increasing myocardial oxygen consumption adding atropine to dipyridamole may improve the diagnostic accuracy of dipyridamole for the detection of CAD.

METHODS

Fifty-two patients (48 men, aged 53 +/- 7 years) underwent a high-dose dipyridamole-echo stress test (0.84 mg/kg over 10 minutes) and coronary arteriography within 15 days from the test. Eighteen out of 52 patients were referred for chest pain; 11 suffered from a previous myocardial infarction (MI) and 23 were studied in the early phase after a first acute MI. Starting after 4 minutes from the end of dipyridamole infusion, atropine was added, in 2 doses of 0.5 mg each, at 1-minute interval in those patients with no echocardiographic evidence of myocardial ischemia after dipyridamole alone. Left ventricular wall motion was analyzed on a 11-segment left ventricular model in a qualitative manner.

RESULTS

Dipyridamole-echo stress test was positive in 23/52 (44%) and negative in 29/52 (56%) patients. In these patients atropine was added resulting in an additional echo positivity in 14/29 patients. Coronary arteriography was normal in 6 patients (12%); 1-vessel CAD was diagnosed in 23 (44%), 2-vessel CAD in 13 (25%) and 3-vessel CAD in 10 (19%) cases. The sensitivity for CAD diagnosis was 48% (22/46) for dipyridamole alone and 76% (35/46) for dipyridamole-atropine echo (p < .005), while the specificity was 83% (5/6) and 80% (4/5) respectively. Diagnostic accuracy increased from 52% (27/52) to 75% (39/52) (p < .001). The better diagnostic accuracy of dipyridamole-atropine echo stress test was mainly related to the increased sensitivity of the combined test in patients with 1-vessel CAD (from 39% to 70%) (p < .005). Peak heart rate was significantly higher after the addition of atropine (100 +/- 17 beats/min) compared to basal (64 +/- 10) and dipyridamole (85 +/- 12) in those patients with a positive dipyridamole-atropine echo stress test. No limiting side effects were elicited with the addition of atropine to dipyridamole.

CONCLUSIONS

The combination of atropine and dipyridamole induces a chronotropic stress adjunctive to flow maldistribution phenomena that permits to increase diagnostic accuracy of dipyridamole-echo stress test particularly in patients with less severe extent of CAD; it is usually well tolerated and safe and may be considered as a useful procedure for optimizing diagnostic value of dipyridamole-echo stress test.

Hemodynamics of volume loading compared with dobutamine in severe right ventricular infarction

To compare the hemodynamic effect of volume loading with that of dobutamine infusion in severe ischemic right ventricular (RV) dysfunction, 11 patients with inferior and RV infarction complicated by low cardiac output syndrome and important hemodynamic derangement (systolic blood pressure < 100 mm Hg, cardiac index < 2.0 liters/min/m2, right atrial pressure > 10 mm Hg) were prospectively studied within 48 hours of symptom onset. After right heart catheterization, volume loading (mean 400 ml saline solution) and dobutamine infusion (5 and 10 micrograms/kg/min over 10 minutes) were performed according to a randomized, crossover design. Volume loading resulted in increased right atrial (from 15 +/- 2 to 19 +/- 3 mm Hg, p < 0.05) and pulmonary capillary (from 15 +/- 2 to 19 +/- 3 mm Hg, p < 0.05) pressures, without increasing cardiac index, heart rate, aortic pressure, or right and left ventricular stroke work index. Dobutamine (5 micrograms/kg/min) increased cardiac index (from 1.5 +/- 0.3 to 1.9 +/- 0.5 liters/min/m2, p < 0.05), incrementing both heart rate (from 61 +/- 12 to 70 +/- 13 beats/min, p < 0.05) and stroke volume index (from 25 +/- 6 to 27 +/- 5 ml/beat/m2, p < 0.05), as well as right (from 1.4 +/- 1.6 to 2.3 +/- 2.2 g.m/m2, p < 0.05) and left (from 21 +/- 7 to 27 +/- 10 g.m/m2, p < 0.05) stroke work indexes; right and left ventricular filling pressures did not decrease. Dobutamine (10 micrograms/kg/min) significantly improved myocardial performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Common carotid intima-media thickness measurement. A method to improve accuracy and precision

BACKGROUND AND PURPOSE

High-resolution ultrasonographic imaging is a noninvasive method that allows estimation of the thickness of the intima-media complex in human carotid arteries. The determination of intima-media thickness involves several steps, each of which may introduce an error that influences the reproducibility of the method. In the present study, apart from the general reproducibility of the determination of intima-media thickness, the error introduced by each step was evaluated.

METHODS

B-mode scans were performed on 14 randomly selected patients. The common carotid arteries were examined in anterior, lateral, and posterior planes, with a standard methodology and by a new method, making use of external reference points.

RESULTS

The error in general reproducibility in determination of the subject's mean intima-media thickness was 5.9%. This parameter was also evaluated in a paired manner after dividing the whole artery into sectors; with this protocol, the percent error in general reproducibility was 15%. The main source of variability in the evaluation of common carotid intima-media thickness was found to lie in the operator's subjectivity in the choice of the carotid sector to be processed (percent error, 10.27%). A method was therefore designed that used external reference points, resulting in reduction of this error by 38.2%.

CONCLUSIONS

While the mean intima-media thickness might be considered a reproducible parameter to evaluate differences between populations exposed to diverse risk factors, evolutional or therapy-induced changes in the individual may be better monitored on defined carotid sectors. This may be achieved with a high reproducibility by use of the proposed method based on external reference points.

Haemodynamic effects of glyceryl trinitrate during continuous 24 hour infusion in patients with heart failure

OBJECTIVE

To investigate whether the susceptibility to tolerance to glyceryl trinitrate is similar in different vascular beds in patients with chronic heart failure.

PATIENTS

Twenty patients with heart failure underwent a continuous infusion of glyceryl trinitrate over 24 hours followed by administration of N-acetylcysteine (5 g intravenously) in a bolus.

MAIN OUTCOME MEASURES

Haemodynamic measurements under control conditions, at peak titration of glyceryl trinitrate at 24 hours, and after N-acetylcysteine; plasma renin activity and packed cell volume.

RESULTS

After 24 hours of infusion the acute reduction in right atrial pressure had largely waned, while pulmonary vascular resistance remained improved and systemic resistance, which was not reduced at peak titration, significantly decreased with respect to control conditions. The effects of N-acetylcysteine and hormonal responses were different in patients who did and did not develop tolerance to glyceryl trinitrate.

CONCLUSIONS

The haemodynamic profile of glyceryl trinitrate changed substantially during the study from a predominantly venodilator action at peak titration to a predominantly arteriolar dilatation after 24 hours of infusion. The different effects of N-acetylcysteine and the different hormonal responses confirm the multifactorial pathogenesis of tolerance to glyceryl trinitrate.

Effects of hydroalcoholic extracts of Portulaca pilosa and Achyrocline satureioides on urinary sodium and potassium excretion

Porulaca pilosa has been used in Brazil as a traditional remedy to cause diuresis, antipyresis and analgesia. Achyrocline satureioides has been used in folk medicine as antiinflammatory, hypoglycemic, sedative and to treat gastrointestinal disorders such as diarrhea and dysentery suggesting that it may affect salt and water reabsorption by the gastrointestinal tract. In the current study, hydroalcoholic extracts of both plants were investigated in order to examine their renal effects. The results support the claim that extracts of P. pilosa present renal effects but not the popular belief that it affects diuresis. It has also been provided that, in rats, it causes an increase in K excretion without a concomitant change in water diuresis or Na excretion. Our findings also support the popular belief that A. satureioides does not apparently have renal effects and it might change renal ion transport based on observations that it affects gastrointestinal reabsorption.

Results of dobutamine stress echocardiography in patients with syndrome X

This study describes the results of Dobutamine stress echocardiography in 10 patients with Syndrome X. The diagnosis of Syndrome X was made on the basis of the presence of exertional angina, positive exercise stress test, negative ergonovine stress test and normal coronary arteries at angiography. All patients underwent Dobutamine stress echocardiography after interruption of any antianginal therapy. Dobutamine was infused starting with a dose of 5 mcg/kg/min over 3 minutes with incremental steps of 5 mcg/kg/min every 3 minutes up to a maximal dose of 40 mcg/kg/min. Two-dimensional echocardiography and 12-lead electrocardiography was monitored during the infusion of the drug. Nine patients received the maximal dose while one patient prematurely stopped the test for the occurrence of side effects. None of the ten patients developed segmental left ventricular wall motion abnormalities indicative of myocardial ischemia; ST-segment depression diagnostic for ischemia developed in 30% of patients; angina was elicited in one of these patients and in two additional patients. A hyperkinetic response to Dobutamine infusion involving all the segments of the left ventricle was observed both in patients with and without chest pain or electrocardiographic changes. In patients with Syndrome X Dobutamine induces a hyperkinetic left ventricular response indicative of normal contractile reserve despite the presence in some cases of angina and electrocardiographic signs of ischemia.

Malignant lymphoma associated with experimentally induced feline immunodeficiency virus infection

A malignant low-grade B-cell lymphoma, primarily in the kidney, is described in a specific-pathogen-free cat experimentally infected with feline immunodeficiency virus (FIV) and free of feline leukaemia virus. At the time of diagnosis the cat showed a marked reduction of circulating CD4+ T lymphocytes, was 2 years old, and had been infected for 18 months. FIV was isolated both from peripheral blood mononuclear cells and the neoplastic tissue. DNA of FIV gag gene was detected in several specimens, including the neoplastic tissue. Even if they do not demonstrate a direct role for virus promotion of lymphomas, these and previous observations indicate that B-cell malignant lymphoma might be associated with FIV infection as reported for human and simian immunodeficiency virus infections.

Detection of feline immunodeficiency virus p24 antigen and p24-specific antibodies by monoclonal antibody-based assays

A panel of monoclonal antibodies (mAbs) detecting distinct B-cell epitopes on p24 core viral protein of feline immunodeficiency virus (FIV) were employed to develop immunoassays to measure p24 concentration in culture and serum samples, to localize p24 in FIV-infected cells and tissues, and to detect anti-p24 antibodies in cat sera. In its optimized configuration the p24 capture assay detected as little as 0.25 ng/ml of protein. The assay was found at least as sensitive as the reverse transcriptase activity assay in FIV-infected lymphocyte cultures and proved capable of detecting p24 antigen in acid pretreated sera from a high proportion of FIV-infected cats. The mAbs were also successfully used to detect the p24 antigen in permeated FIV-infected cells by flow cytometry and in tissue sections from FIV-infected cats by immunohistochemical staining. Anti-p24 antibodies in FIV-infected cat sera were assayed by a competitive capture ELISA which readily identified occasional false positive results provided by a standard ELISA using purified whole FIV-coated wells.

[Low anterior resection of the rectum using mechanical anastomosis in intestinal endometriosis]

A case of sigmoid-rectal endometriosis prompted the authors to focus attention on the question of indications for surgery and operative tactics in intestinal endometriosis. In this case, the presence of a pelvic mass which could not be cut away from the intestinal wall without the risk of perforation led to the performance of a low anterior resection of the rectum with mechanical stapler, a choice which was certainly radical but necessary in view of the impossibility of excluding the malignant nature of the mass either macroscopically or extemporaneously.

[The echo-dobutamine and echo-dipyridamole tests in assessing vital myocardium and residual ischemia in myocardial infarct after thrombolysis]

The aim of the study was to compare the ability of dobutamine and dipyridamole echocardiography to detect stunned but viable myocardium early after acute myocardial infarction, to predict spontaneous functional recovery of the reperfused myocardium at 2 months and to detect myocardial ischemia in the infarcted area. Within 10 days from acute myocardial infarction, 47 patients, 29 anterior and 18 inferior, 41 Q-wave and 6 non Q-wave infarctions, underwent dobutamine echocardiography test at low-dose (5-10 mcg/kg/min over 5 min) and high-dose (20-40 mgc/kg/min over 3 min) and to dipyridamole echocardiography test (0.56 mg/kg over 4 min + 0.28 mg/kg over 2 min) in different days and in random order, after interruption of any vasoactive drug. Resting echocardiography was repeated at 2 months in 38/47 patients. Regional wall motion analysis was performed in a qualitative manner on a 14-segment model; viability was defined as improvement of 1 grade or more of at least 2 basally asynergic segments in the infarcted area. Ischemia was defined as an improvement followed by significant deterioration of contractility of the infarcted segments or deterioration of the infarcted area. All patients underwent coronary arteriography within 1 month from admission. Viability was detected by low-dose dobutamine in 34/47 patients (72%) and in 131/297 (44%) of basally asynergic segments compared to only 21/47 patients (45%) and in 66/297 segments (22%) detected by dipyridamole; myocardial ischemia was induced by dobutamine in 64% of patients compared to 36% by dipyridamole. Late spontaneous functional recovery was detected in 21/38 patients (57%) and in 70/244 (29%) of asynergic segments. Sensitivity of dobutamine and dipyridamole echocardiography for predicting spontaneous functional recovery was 70% and 46% specificity 69% and 83%, positive predictive value 48% and 52%, negative predictive value 85% and 79% respectively. Dobutamine correctly identified the presence of a significant stenosis of the infarct-related artery in 74% of cases compared with 43% of dipyridamole; specificity for detecting stenosis was 67% for dobutamine and 83% for dipyridamole. In conclusion, in patients with thrombolyzed myocardial infarction dobutamine echocardiography detects viable myocardium with late spontaneous recovery in a greater proportion of patients and segments than dipyridamole; dobutamine has a higher sensitivity but a lower specificity compared to dipyridamole for identifying a residual stenosis of the infarct-related artery that may jeopardize myocardium in the area at risk.

[Echocardiography-dobutamine test in the short-term evaluation of the results of coronary angioplasty]

BACKGROUND

Coronary angioplasty is commonly performed as a means of coronary revascularization, but at present no method has proven to be of definite value in assessing the functional result of a given angiographic procedure.

OBJECTIVES

The purpose of this study was to evaluate whether dobutamine stress echocardiography can detect a reversal of ischemia-induced left ventricular regional wall motion abnormalities 15 days after an angiographically successful percutaneous transluminal coronary angioplasty (PTCA).

METHODS

25 patients underwent dobutamine stress echocardiography 24-48 hours before and 15 days after an elective angiographically successful PTCA. Twelve out of 25 patients (48%) suffered from a previous myocardial infarction. Symptomatic myocardial ischemia was documented before PTCA in 18/25 patients (72%) and asymptomatic ischemia in 7/25 (28%). Dobutamine was infused utilizing incremental steps of 5 mcg/kg/min over 3 minutes, up to a maximal dose of 40 mcg/kg/min. Echocardiographic images were stored on video tape and analyzed in a qualitative manner by two independent and experienced cardiologists without knowledge of the angiographic data. An asynergy score (from 0 = normal to 3 = dyskinesia) was calculated using a 14-segment left ventricular model in basal conditions and at peak stress, before and after PTCA. All tests were performed taking the patients off the antianginal therapy.

RESULTS

One-vessel coronary artery disease was present in 18/25 (72%) patients, and two-vessel disease in 7/25 (28%) four of these 7 patients underwent PTCA on both involved vessels; mean diameter of the stenosis was 91 +/- 6% before PTCA, and was reduced to 22 +/- 8% after PTCA. Dobutamine stress echocardiography induced wall motion abnormalities in 24/25 patients before and in 4/25 after PTCA; the frequency of dobutamine-induced wall motion abnormalities significantly decreased from 96% to 12% before and after angioplasty (p < .01). All patients developed regional wall motion abnormalities in the region supplied by the dilated vessel. Wall motion score at peak dobutamine infusion improved from 8.5 +/- 4.8 before PTCA to 2.6 +/- 4.9 after PTCA (p < .001). There was a significant increase in the rate-pressure product achieved during the test after PTCA (21300 +/- 400 bts/min.mmHg) compared to the test performed before PTCA (19000 +/- 500 bts/min.mmHg) (p < .05). Dobutamine induced angina in 6/25 patients (24%) and ST-segment changes in 19/25 patients (76%) before PTCA, whereas angina occurred only once after PTCA and ST-segment changes 6 times only after PTCA. No major side effects occurred during dobutamine infusion both before and after PTCA.

CONCLUSIONS

Our study indicates that dobutamine stress echocardiography is a feasible and safe method that accurately demonstrates an early improvement in stress-induced regional left ventricular dysfunction after an angiographically successful coronary angioplasty.

Functional adenosine A1 receptors in goldfish brain: regional distribution and inhibition of K(+)-evoked glutamate release from cerebellar slices

In goldfish brain, [3H]cyclohexyladenosine binding sites are ubiquitously distributed with a maximum in the hypothalamus and a minimum in the spinal cord. The binding parameters measured in cerebellar membranes (Kd = 0.88 +/- 0.08 nM; Bmax = 59.65 +/- 2.62 fmol/mg protein) are not significantly different from those of the whole brain. In perfused goldfish cerebellar slices, stimulation of cyclic AMP accumulation by 10(-5) M forskolin was markedly reduced (58.7%) by treatment with 10(-4) M cyclohexyladenosine, an adenosine A1 receptor agonist, and the reduction was reversed in the presence of 10(-4) M 8-cyclopentyltheophylline, a selective A1 receptor antagonist. In the same brain preparation, 30 mM K+ stimulated the release of glutamate, glutamine, glycine and GABA in a Ca(2+)-dependent manner, whereas the aspartate and taurine release was Ca(2+)-independent. Cyclohexyladenosine inhibited the 30 mM K(+)-evoked release of glutamate in a dose-related manner. This effect was reversed by 8-cyclopentyltheophylline. These results support the hypothesis that adenosine A1 receptors present in goldfish cerebellum are involved in the modulation of glutamate transmitter release.

Dobutamine stress echocardiography for assessment of myocardial viability and ischemia in acute myocardial infarction treated with thrombolysis

To evaluate the role of dobutamine echocardiography for early assessment of myocardial viability and ischemia in acute myocardial infarction (MI), 59 patients with thrombolyzed acute MI underwent low- (5-10 micrograms/kg/min, 8 patients) and high-dose (20-40 micrograms/kg/min, 51 patients) dobutamine echocardiography at a mean of 8 +/- 4 days after acute MI. Myocardial viability in the infarct zone was documented in 43 of 59 (73%) patients (group 1), in whom mean asynergy score index decreased from 1.6 +/- 0.3 at baseline to 1.3 +/- 0.2 (p < 0.001), after low-dose dobutamine. No viability was present in 16 of 59 (27%) patients (group 2). At follow-up, recovery of regional contractile function was observed in group 1 (asynergy score index decreased from 1.6 +/- 0.3 to 1.4 +/- 0.3; p < 0.001), but not in group 2 patients. Sensitivity, specificity, and negative and positive predictive values of low-dose dobutamine echocardiography in predicting spontaneous recovery of function were 79%, 68%, 50%, and 89%, respectively. Of the 51 patients who underwent high-dose dobutamine, 26 of 36 (72%) group 1 patients showed a deterioration of contractility in the infarct zone indicative of myocardial ischemia compared with only 1 of 15 (7%) group 2 patients. At follow-up, recovery of regional function was greater in patients with no evidence of myocardial ischemia at high doses than in those with an ischemic response.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of dobutamine stress echocardiography, dipyridamole stress echocardiography and exercise stress testing for diagnosis of coronary artery disease

To compare the value of dobutamine and dipyridamole stress echocardiography with exercise stress testing for the diagnosis of coronary artery disease (CAD), 80 patients with chest pain of suspected myocardial ischemic origin (57 with CAD and 23 without significant CAD) underwent dobutamine stress echocardiography (5 to 40 micrograms/kg/min), dipyridamole echocardiography (0.84 mg/kg over 10 minutes) and bicycle exercise electrocardiography after discontinuation of antianginal treatment. Dobutamine echocardiography and exercise testing revealed a higher overall sensitivity than dipyridamole echocardiography (79 vs 60%, p < 0.005; 77 vs 60%, p < 0.05, respectively); this finding was due to a higher dobutamine and exercise sensitivity in 1-vessel CAD (62 vs 33%, p < 0.05 for both tests), whereas sensitivity of the 3 tests was similar in multivessel CAD. Dobutamine and dipyridamole showed a higher specificity than exercise (83 vs 43%, p < 0.01; 96 vs 43%, p < 0.005, respectively). Diagnostic accuracy of dobutamine echocardiography was higher than that of exercise (80 vs 67%, p < 0.05), whereas the difference with dipyridamole (80 vs 70%) was not significant. In the tests that yielded positive results, double product during exercise was significantly higher than that during dobutamine and dipyridamole echocardiography. No major complications occurred during the tests, but adverse effects were more frequent during dobutamine testing. Thus, dobutamine echocardiography may be superior to dipyridamole echocardiography and exercise electrocardiography for the diagnosis of CAD.

Adenosine A1 receptor-mediated inhibition of evoked glutamate release is coupled to calcium influx decrease in goldfish brain synaptosomes

Binding of [3H]cyclohexyladenosine (CHA) to the cellular fractions and P2 subfractions of the goldfish brain was studied. The A1 receptor density was predominantly in synaptosomal membranes. In goldfish brain synaptosomes (P2), 30 mM K+ stimulated glutamate, taurine and GABA release in a Ca(2+)-dependent fashion, whereas the aspartate release was Ca(2+)-independent. Adenosine, R-phenylisopropyladenosine (R-PIA) and CHA (100 microM) inhibited K(+)-stimulated glutamate release (31%, 34% and 45%, respectively). All of these effects were reversed by the selective adenosine A1 receptor antagonist, 8-cyclopentyltheophylline (CPT). In the same synaptosomal preparation, K+ (30 mM) stimulated Ca2+ influx (46.8 +/- 6.8%) and this increase was completely abolished by pretreatment with 100 nM omega-conotoxin. Pretreatment with 100 microM R-PIA or 100 microM CHA, reduced the evoked increase of intra-synaptosomal Ca2+ concentration, respectively by 37.7 +/- 4.3% and 39.7 +/- 9.0%. A possible correlation between presynaptic A1 receptor inhibition of glutamate release and inhibition of calcium influx is discussed.

Detection of feline immunodeficiency virus in saliva and plasma by cultivation and polymerase chain reaction

The rates of feline immunodeficiency virus (FIV) isolation from saliva, plasma, and peripheral blood mononuclear cells (PBMC) of infected cats were compared; isolation rates were 18, 14, and 81%, respectively, in naturally infected cats and 25, 57, and 100%, respectively, in experimentally infected animals. There was no obvious relationship between isolation rate and clinical stage or between isolation rate and the titer of neutralizing antibody in serum. Virus could be isolated from one salivary gland as early as 1 week postinfection and, on a more regular basis, starting at 3 weeks postinfection, when, however, most other tissues were also positive. Polymerase chain reaction analysis showed that FIV genomes are present in saliva and plasma more frequently than expected on the basis of isolation data. Saliva was also found to contain viral DNA, indicating that it may harbor virus-infected cells as well as free virus. The addition of plasma but not of saliva to PBMC cultures delayed FIV growth. Isolation from plasma may be hampered by FIV neutralizing antibody and by the cytotoxic activity of this fluid for the PBMC used as a cell substrate.

Renal involvement in feline immunodeficiency virus infection: a clinicopathological study

Renal tissues from 15 cats naturally infected with feline immunodeficiency virus (FIV) were examined histologically, immunohistochemically and ultrastructurally. Renal function and urinary proteins were also studied. Kidney abnormalities were found in 12 cats and were characterized by mesangial widening with segmental to diffuse glomerulosclerosis and presence of IgM and C3, and scanty IgG deposits in the mesangium. Tubulointerstitial lesions were also present. In 6 cats the lesions were severe enough to cause marked increase in blood urea nitrogen and creatinine, and heavy glomerular nonselective proteinuria. These findings suggest that a renal involvement is a frequent occurrence in FIV-infected cats. As the histopathological features observed were similar to those described in HIV-infected patients, FIV-infected cats may represent a valuable model for a better understanding of HIV-associated nephropathy in humans.

[Malignant mesothelioma located in the pleura: its radical surgical treatment]

The authors report a rare case of localized malignant pleural mesothelioma infiltrating the thoracic wall. The absence of widespread pleural involvement allowed for a radical operation with removal of a large portion of the thoracic wall. However, due to rarity of such tumor, an hypothesis on long term prognosis is difficult to formulate.

[Hemodynamic effects of enalapril in patients with non-complicated acute myocardial infarct]

To evaluate the hemodynamic effects of the first oral administration of enalapril maleate, a long-acting ACE-inhibitor, in the early phase of an acute uncomplicated myocardial infarction, we studied 15 patients, in Killip class I or II, within 72 hours from the onset of symptoms. Hemodynamic measurements were obtained by a triple lumen 7 F Swan-Ganz catheter, inserted into the pulmonary artery, under control conditions and 2, 4, 6, 8 and 12 hours after 10 mg (15 patients) and 20 mg (11 patients) of the drug. Ten milligrams of enalapril reduced systolic and mean arterial blood pressure (from 118 +/- 17 to 111 +/- 18 mmHg, p < .05, and from 92 +/- 12 to 83 +/- 12 mmHg, p < .01, respectively), with a maximum effect after 4 hours from administration. Heart rate and vascular resistances showed an insignificant trend toward reduction, and no changes were observed in left ventricular systolic work index, right and left ventricular filling pressures or cardiac index. Hemodynamic changes induced by 20 mg of the drug, in a smaller group of patients, had a similar trend, which did not reach a statistical significance. In conclusion, in patients with acute uncomplicated myocardial infarction, a single oral dose of enalapril maleate is safe and well tolerated, does not induce severe hypotension, and produces potentially beneficial changes in hemodynamics.

[Dihydroergocristine in organic brain psychosyndrome. Multicenter placebo-controlled clinical double-blind study in 240 patients]

The aim of this 3-month study was to assess the activity of dihydroergocristine (DHEC, CAS 17479-15-5) on organic brain syndrome. DHEC is an ergot alkaloid derivative with a dopaminergic activity on the central nervous system (CNS). It improves cerebral metabolism and increases the bioelectric potential in the cerebral cortex. The randomized double-blind trial versus placebo involved 240 outpatients (138 females and 102 males, mean age 68 years) recruited in 6 hospitals. Subjects with Hachinski Ischemic Score > 6 and Mini Mental State < 22 were excluded. Patients were randomly divided into 4 groups of 60 subjects each to receive either one 6-mg DHEC oral vial or placebo vial, or one 6-mg DHEC tablet or placebo tablet once daily for 3 months. Neuropsychological tests were performed at baseline, and then after 45 and 90 days of treatment. The statistical analysis of results showed a significant difference (p < 0.01) between DHEC and placebo groups with regard to the following tests: "Scale of Clinical Assessment for Geriatrics (SCAG), Digit Symbol, Digit Span, Toulouse-Pieron, Hamilton Depression Rating Scale and Rey's Words". The amelioration of clinical symptoms pointed out the equivalence of DHEC oral vials and tablets. The drug was well tolerated. It is concluded that DHEC is an effective and safe drug in the treatment or organic brain syndrome.