First-line therapies for H. pylori infection in Italy: a pooled-data analysis.

Background: Curing H. pylori infection remains challenging, and the use of most effective first-line therapy represents a therapeutic cornerstone. To monitor the efficacy of first-line therapies in Italy, we designed a systematic review with pooled- data analysis of data published in the last 15 years. Methods: The search was focused on standard regimens and adult patients. Studies that included modified therapy regimens, pediatric patients, case series with less than 5 patients, and those in language other than English were excluded. Results: A total of 40 studies, with 74 therapeutic arms and 13,539 patients were evaluated. Among the 14-day triple therapies, the combination with proton pump inhibitor (PPI), clarithromycin and amoxicillin achieved the highest (77.9%) success rate, whilst the lowest success rate (62.7%) was observed following the 14-day PPI, clarithromycin and tinidazole regimen. The overall efficacy of triple therapies significantly decreased from 75.7% to 72.1% in the last decade. Sequential (88.3% on 3431 patients), concomitant (88.8% on 376 patients), and the bismuth-based quadruple therapy with three-in-one capsule, containing bismuth subcitrate potassium (140 mg), metronidazole (125 mg), tetracycline (125 mg) (90.4% on 999 patients) achieved similarly high eradication rates, but data on concomitant are still limited. The bismuth-based was associated with the higher (38.7%) incidence of side-effects. Conclusions: Data found that all triple therapies, irrespective of drug combination and therapy duration, should be abandoned in Italy due to their unacceptable low success rates. Monitoring the efficacy of standard first-line therapies in other countries could be clinically useful for both patients and clinicians.

Antibiotic Resistance and Therapy Outcome in H. pylori Eradication Failure Patients.

Helicobacter pylori (H. pylori) eradication fails in a definite amount of patients despite one or more therapeutic attempts. Curing these patients is progressively more difficult, due to development of antibiotic resistance. Current guidelines suggest testing antibiotic susceptibility in H. pylori isolates following two therapeutic attempts. AIM: to evaluate the development of antibiotic resistance, MIC values trends and therapeutic outcomes in patients who failed at least one H. pylori eradication therapy. METHODS: consecutive patients, referred to perform upper gastrointestinal endoscopy (UGIE) to our Unit from January 2009 to January 2019 following at least one therapeutic attempt were considered. Bacterial resistance towards clarithromycin, metronidazole and levofloxacin was tested. Patients received either a susceptibility-guided therapy or Pylera®. RESULTS: a total of 1223 patients were H. pylori positive, and antibiotic susceptibility was available for 1037. The rate of antibiotic resistance and MIC values significantly increased paralleling the number of previous therapeutic attempts. Eradication rates of antibiogram-tailored therapies remained stable, except for the sequential therapy if used as a third line. As a rescue treatment, the Pylera® therapy achieved cure rates comparable to those of the other culture-guided therapies. CONCLUSIONS: A significant increase in the secondary resistance towards the three tested antibiotics was observed, both as rate and MIC values, in correlation with the number of therapy failures. These findings should be considered when administering an empirical second-line therapy. Pylera® therapy eradication rates are comparable to culture-tailored therapies.

Poverty and immigration as a barrier to iodine intake and maternal adherence to iodine supplementation.

PURPOSE: Iodine deficiency still remains a significant health issue worldwide. Pregnant and lactating women are at risk for iodine deficiency when living in mild iodine-deficient areas such as Italy. This study aims at evaluating the consumption of iodized salt, iodine-rich-foods and maternal micronutrient supplements in a group of women with limited access to the Italian National Health System. METHODS: A cross-sectional survey was conducted among immigrant and Italian women living in poverty and referring to 40 Non-Governmental Organization throughout Italy for their health needs. 3483 women answered the ad hoc questionnaire between January 2017 and February 2018. RESULTS: The consumption of iodized salt was very low, and even lower among immigrant women. Determinants of iodized salt consumption were the period spent in Italy for immigrant women and living in a family-type setting, parity and, particularly, the degree of education for Italian ones. 17.5% of immigrant women and 8.6% of the Italian ones reported a diagnosis of thyroid disease. 521 women, 75.4% of whom were immigrants, were pregnant or breast-feeding. The majority (57.3%) had no specific maternal supplementation. CONCLUSIONS: Both Italian and immigrating women with a low income or without access to the public health system have a poor adherence both to the salt iodization policy and to folic acid and iodine supplements in preconception and pregnancy. They also referred a low-frequency intake of iodine-rich-foods. The identification of barriers to health care access could be useful to promote specific health interventions in this target population.

Cameron lesions: A still overlooked diagnosis. Case report and systematic review of literature.

Cameron lesions are erosive-ulcerative alterations of gastric mucosa occurring in patients with large hiatal hernia, potentially causing gastrointestinal bleeding and iron deficiency anaemia. Diagnosis may be challenging, and not infrequently erosions are overlooked at endoscopy, so that repeated and unnecessary diagnostic procedures are performed, particularly in those patients with chronic anaemia. We described two peculiar cases of patients with iron deficiency anaemia in whom Cameron lesions were either overlooked or misinterpreted. By reviewing data of 22publications reporting endoscopic and clinical data of 140patients, we noted a large prevalence of females (75%). The most frequent presenting symptoms were anaemia (62%) and overt gastrointestinal bleeding (36%). Noteworthy, as many as 69% of patients underwent one or more previous upper endoscopy before diagnosis of Cameron lesion was achieved. Patients were mainly treated with proton pump inhibitor (PPI) therapy and iron supplementation. Moreover, endoscopic haemostasis was performed in 10% of case, blood transfusion was required in one third of cases, and a similar quote of patients underwent a surgical approach for hiatal hernia repair. The observation that as many as 60% patients were already receiving standard PPI therapy when diagnosis was performed would suggest that either long-term treatment with adequate dose PPI or surgical approach for hiatal hernia repair is required. In conclusion, Cameron lesion is still an overlooked diagnosis in patients with iron deficiency anaemia in whom a 5-9.2% prevalence has been reported.

Impact of primary antibiotic resistance on the effectiveness of sequential therapy for Helicobacter pylori infection: lessons from a 5-year study on a large number of strains.

BACKGROUND: The increasing prevalence of strains resistant to antimicrobial agents is a critical issue in the management of Helicobacter pylori (H. pylori) infection. AIMS: (1) To evaluate the prevalence of primary resistance to clarithromycin, metronidazole and levofloxacin (2) to assess the effectiveness of sequential therapy on resistant strains (3) to identify the minimum number of subjects to enrol for evaluating the effectiveness of an eradication regimen in patients harbouring resistant strains. METHODS: Consecutive 1682 treatment naïve H. pylori-positive patients referred for upper GI endoscopy between 2010 and 2015 were studied and resistances assessed by E-test. Sequential therapy was offered, effectiveness evaluated and analysed. RESULTS: H. pylori-primary resistance to antimicrobials tested was high, and increased between 2010 and 2015. Eradication rates were (estimates and 95% CIs): 97.3% (95.6-98.4) in strains susceptible to clarithromycin and metronidazole; 96.1% (91.7-98.2) in strains resistant to metronidazole but susceptible to clarithromycin; 93.4% (88.2-96.4) in strains resistant to clarithromycin but susceptible to metronidazole; 83.1% (77.7-87.3) in strains resistant to clarithromycin and metronidazole. For any treatment with a 75%-85% eradication rate, some 98-144 patients with resistant strains need to be studied to get reliable information on effectiveness in these patients. CONCLUSIONS: H. pylori-primary resistance is increasing and represents the most critical factor affecting effectiveness. Sequential therapy eradicated 83% of strains resistant to clarithromycin and metronidazole. Reliable estimates of the effectiveness of a given regimen in patients harbouring resistant strains can be obtained only by assessing a large number of strains.

Drugs Delivery by Charities: A Possible Epidemiologic Indicator in Children of Undocumented Migrants.

Describing the health status of a population is difficult, especially in the case of irregular migrants who are now a growing population in western Countries. Data for children of these families are almost inexistent. In the absence of databases on this peculiar pediatric population, we analyzed drugs dispensation by a major Charity to have an insight into their health needs. This observational retrospective study was carried out during the entire 2015 and enrolled 628 undocumented children. A cohort of 8438 adult patients belonging to the same ethnic groups was used for comparison. Respiratory drugs were those most commonly prescribed, followed by those for skin and ocular diseases and by those for gastrointestinal disorders. Also in adults respiratory medications were the most dispensed, but almost in equal measure than cardiovascular drugs.To our knowledge this is the first study on the health needs of undocumented children residing in a western Country. The method we used seems to be a useful method for epidemiological analysis. As could be expected, respiratory and skin diseases ranked first, possibly owing to environmental factors.

The burden of chronic noncommunicable diseases in undocumented migrants: a 1-year survey of drugs dispensation by a non-governmental organization in Italy.

OBJECTIVES: This study was carried out with two objectives. The first one was to have an insight into the prevalence of chronic noncommunicable diseases (CNCD) in undocumented migrants, and the second one was to evaluate if differences existed among different ethnic groups. STUDY DESIGN: The study is based on the collection of data on drug dispensation by a non-governmental organization (NGO) providing free medical assistance to undocumented migrants in Milan, Italy. All the prescriptions to adult subjects from January 1 to December 31 2014 (total 8438) were recorded and analyzed. All the data available for the patients receiving prescriptions (age, gender and country of birth) were also collected in anonymous form. Ethical approval for the study was given by the Ethics Committee of the NGO. METHODS: Drugs were grouped according to the anatomical therapeutic chemical (ATC) classification and their quantities expressed as daily defined doses (DDDs)/1000 patients/day. The 56 ATC levels were divided into three groups according to their use for acute, chronic, or both acute and chronic diseases. The statistical analysis of drug dispensation was performed for the whole population and for the five ethnic groups into which it had been divided. RESULTS: Prescription of medicines for chronic conditions was significantly greater than for acute (154.2 ± 45.9 vs 51.3 ± 18.4 DDD/1000 patients/day, P < 0.02) and for both acute and chronic conditions (57.9 ± 12.8 DDD/1000 patients/day, P < 0.02). Five ATC classes accounted for 60% of all chronic prescriptions. They were differently distributed among the five ethnic groups (e.g., Asians required more antihypertensives and antidiabetics, East Europeans required more lipid modifying drugs, antihypertensives and antithrombotics). CONCLUSIONS: Our data show an important use of medicines for chronic diseases in a population of undocumented migrants. Though with some limitations, this could be an indicator of a high prevalence of CNCD in this population, with significant differences among different ethnic groups. This situation should be considered when planning health interventions, also in consideration of the fact that it could have an impact on European Health Services in a short time.

Accuracy of a new ultrafast rapid urease test to diagnose Helicobacter pylori infection in 1000 consecutive dyspeptic patients.

BACKGROUND: Rapid diagnostic tools for Helicobacter pylori are important in endoscopy. AIMS: To assess the accuracy of a new 5 min rapid urease test (UFT300, ABS Srl, Cernusco sul Naviglio, Milan, Italy) and to compare it with the 1 h Pyloritek (Serim Laboratories, Elkhart, IN, USA) and the 24 h CLO test (Kimberly-Clark Ballard Medical Products, Roswell, GA, USA). METHOD: Consecutive dyspeptic patients referred to our unit for endoscopy were prospectively studied. All patients underwent a (13)C-urea-breath test, histology and the UFT300 (ABS Srl; Cernusco sul Naviglio, Milan, Italy). In a sub-set of patients (n = 375), two additional RUTs were performed. Patients were deemed infected if both (13)C-UBT and histology were positive. RUTs were read at 1, 5, and 60 min. RESULTS: Of 1000 enrolled patients 45.3% were infected with H. pylori. The sensitivity of the UFT 300 was 90.3%, 94.5% and 96.2% at 1, 5 and 60 min respectively (specificity 100%). The Pyloritek and the UFT were comparable, but the CLO test was not reliable at 5 and 60 min. CONCLUSION: The UFT 300 test is comparable to the Pyloritek test, but the CLO test is significantly less sensitive at early time points. Reading test results at 1 min may increase false negative results, thereby decreasing sensitivity.

Serum ECP and MPO are increased during exacerbations of chronic bronchitis with airway obstruction.

Many studies have demonstrated that, in asthma, serum levels of eosinophil cationic protein (ECP) are related to the activity and severity of the disease and can be used to evaluate the response to steroid treatment. During exacerbations of chronic bronchitis, airway inflammation shows some features of asthmatic inflammatory processes, with recruitment of eosinophils and recovery of significant amounts of ECP in bronchial lavage fluid (BAL). Involvement of neutrophils, with high levels of myeloperoxidase (MPO), is, on the contrary, typical of this latter disease, and not shared with asthma. In spite of the information collected with BAL and bronchial biopsy studies, few data still exist on serum levels of these proteins in chronic bronchitis. The objective of this study was to assess if serum levels of ECP and MPO are specifically increased in exacerbations of chronic bronchitis, as compared to other non-asthmatic acute respiratory disturbances. Serum ECP, MPO and immunoglobulin E (IgE) levels were measured in 17 non-atopic patients with exacerbation of chronic bronchitis with airway obstruction (COPD) and in 11 control subjects seeking emergency medical treatment for unrelated acute respiratory problems. Spirometry was performed in patients able to give the necessary collaboration. All the subjects of this study were recruited from the emergency department. Both ECP and MPO were significantly increased in serum from patients with exacerbated COPD (22.2 +/- 4.1 vs 9.5 +/- 1.4 mcg/L and 853 +/- 168 vs 375 +/- 41 mcg/L) and a strong correlation existed between these two variables (r = 0.782). A further control group was made of 11 patients with stable COPD. These subjects had levels of both ECP (13.1 +/- 2.7 mcg/L) and MPO (469 +/- 71) significantly lower than patients with exacerbated disease and higher than those without COPD. We conclude that serum ECP and MPO are increased during the exacerbations of COPD. These observations can give a basis for further studies aimed to evaluate the utility of these two proteins as markers of activity and severity of COPD.

[Renal hemangiopericytoma. Anatomo-pathologic and clinico-therapeutic considerations. A case report]. / L'emangiopericitoma renale. Considerazioni anatomo-patologiche e clinico-terapeutiche. Descrizione di un caso.

The Authors report a case of renal hemangiopericytoma, whose interest is related to the extreme rarity (24 cases reported until today), its insidious growth, the late in diagnosis, its uncertain clinical-biological evolution, not always predictable. Considering chemotherapy and radiotherapy ineffectiveness, an adequate treatment for such a neoplasm requires the surgical therapy, which must be followed by a careful follow-up.

Radiological assessment of clinical staging of lung cancer.

Technical details of volumetric spiral CT and high resolution CT are presented. The role of CT scan in lung cancer is discussed: confirmation of a suspected lesion, identification of an unknown one, clinical staging, planning bioptic procedures and follow-up. In clinical staging, CT scan measures tumor diameter and relationship with surrounding structures (T factor) as well as investigates about nodal status (N factor) at the hilum or in the mediastinum but the limitation is due to the difficulty of distinguish between nodal inflammatory enlargement and metastatic involvement. Moreover, CT can be extended to the upper abdomen aimed of assessing adrenals, kidneys and liver (M factor).

[Defecography by spiral computed tomography]. / La defecografia con Tomografia Computerizzata spirale.

PURPOSE: We investigated the possible role of helical CT defecography in pelvic floor disorders by comparing our results with those of conventional defecography. MATERIAL AND METHODS: Our series consisted of 90 patients, namely 62 women and 28 men, ranging in age 24-82 years. They were all submitted to conventional defecography, and 18 questionable cases were also studied with helical CT defecography. The conventional examination was performed during the 4 standard phases of resting, squeezing, Valsalva and straining; we used a remote-control unit. The parameters for helical CT defecography were: 5 mm beam collimation, pitch 2, 120 KV, 250 mAs and 18-20 degrees gantry inclination to acquire coronal images of the pelvic floor. The rectal ampulla was distended with a bolus of 300 mL nonionic iodinated contrast agent (dilution: 3 g/cc). The patient wore a napkin and was seated on the table, except for those who could not hold the position and were thus examined supine. Twenty-second helical scans were performed at rest and during evacuation; multiplanar reconstructions were obtained especially on the sagittal plane for comparison with conventional defecographic images. RESULTS: An unquestionable diagnosis could be made in all the 18 patients submitted to helical CT defecography. The diagnosis was in agreement with proctology results and added new information in all cases. Sixteen patients had constipation and 2 fecal incontinence--one from rectal prolapse and the other from a rectovaginal fistula. In this latter case helical CT defecography permitted to confirm the fistula and suggest its course. One patient had a previously undetected ovarian cancer metastatic to the anterior rectal wall. DISCUSSION AND CONCLUSIONS: Coronal helical CT defecography images permitted to map the perineal floor muscles, while sagittal reconstructions provided information on the ampulla and the levator ani. To conclude, helical CT defecography performed well in the study of pelvic floor disorders and can follow conventional defecography especially in questionable cases.

[An echocardiographic study of left ventricular diastolic function in patients with diabetes mellitus type 2]. / Studio ecocardiografico della funzione diastolica del ventricolo sinistro in pazienti con diabete mellito di tipo 2.

AIM OF THE STUDY: To evaluate left ventricular diastolic function by Doppler echocardiography in patients with type 2 (non-insulin-dependent) diabetes mellitus, without coronary artery disease. BACKGROUND: Previous studies suggest that the velocity curve obtained by Doppler echocardiography of the mitral inflow may reflect the filling pattern of the left ventricle. METHODS AND RESULTS: To evaluate the presence of diastolic impairment of the left ventricle in diabetic patients without evidence of coronary artery disease, 30 patients with non-insulin-dependent diabetes mellitus and 20 normal control subjects underwent M-mode, two-dimensional (2-D) and Doppler echocardiography. In the group of diabetic patients (Diabetics), the peak E wave velocity was 0.70 +/- 0.11 m/sec, while in the control group (Controls) it was 1.1 +/- 0.23 m/sec (mean values, +SD, p < 0.001). The peak A wave velocity was 0.89 +/- 0.17 in Diabetics, versus 0.60 +/- 0.34 in Controls. Consequently, E/A ratio was 0.81 +/- 0.18 in Diabetics, versus 1.73 +/- 0.29 in Controls (p < 0.001). Isovolumic relaxation time was 0.08 +/- 0.021 sec in Diabetics, while in Controls it was 0.04 +/- 0.02 sec (p < 0.001). Left atrium diameter was 41 +/- 11 mm in Diabetics, and 37 +/- 4 mm in Controls (p = NS). Left ventricular volumes, ejection fraction, interventricular septal and posterior wall thickness were similar in both groups. No correlation was found between diabetes duration and diastolic function indexes. In Diabetics no correlation was found between age and E/A ratio (correlation coefficient +/- 0.11) while in Controls E/A ratio was lower in the older subjects (r = +/- 0.75). This ratio was 1.89 +/- 0.20 in Controls aged < 65 years, and 1.6 +/- 0.33 in Controls aged > or = 65 years. (p = 0.06). These data suggest that 1) E/A ratio and isovolumic relaxation time are significantly altered in non-insulin-dependent diabetic patients without coronary artery disease; 2) Doppler echocardiography is a useful technique to detect left ventricular diastolic impairment; 3) diastolic impairment seems not to correlate with disease duration; 4) systolic function is normal in our group of type 2 diabetic patients.

The hyperfibrinolytic state of liver cirrhosis: possible pathogenetic role of ascites.

We evaluated coagulation and fibrinolytic parameters in both plasma and ascitic fluid of 39 patients with ascites secondary to liver cirrhosis and in 14 cirrhotic patients without ascites, in order to verify if the peritoneal compartment could be involved in the pathogenesis of the hyperfibrinolytic state of the disease. An activation of fibrinolysis, as suggested by increased levels of FDP, D-dimer and tissue plasminogen activator (t-PA) was demonstrated in both ascitic fluid and to a lesser extent in plasma. A positive correlation was also observed between plasma and ascitic fluid plasminogen, anti-plasmin and fibrinogen, while a negative correlation was found between plasma and ascitic fluid plasminogen activator inhibitor-1 (PAI-1). Moreover, plasma PAI-1 was significantly lower in patients with ascites than in those without ascites and among ascitic patients in those who had bleeding into soft tissues when compared to those who did not present haemorrhagic events. Finally, a significant association was also shown between positivity for plasma D-dimer (> 200 ng/ml) and the presence of ascites. Taken together, our data suggest an exchange of some coagulation and fibrinolytic proteins between plasma and ascitic fluid and point out the key role of PAI-1 in regulating plasma fibrinolytic potential and in bleeding complications in cirrhotic patients.

[Rare anatomic coronary variant. Description of a case]. / Rara variante anatomica coronarica. Descrizione di un caso.

A case of a patient with post-infarction angina and peculiar abnormalities of the coronary arteries is reported. We describe the anatomic findings as well as the possible therapeutical options.

Structural and functional characterization of plasma fibronectin in patients with essential mixed cryoglobulinaemia.

Experimental studies suggest that plasma fibronectin may be involved in the cryoprecipitation of cryoglobulins in essential mixed cryoglobulinaemia; reduced plasma concentrations of the glycoprotein have been shown in the disease. The present work was undertaken in order to verify this latter finding and to detect a possible structural alteration of plasma fibronectin as result of enzymatic digestion of the molecule in vivo. This could, in turn, induce a decreased reactivity of the protein in immunometric assays and a reduced opsonic activity, which is normally due to the affinity of fibronectin to the C1q component of complement. Moreover, since a polymorphic variant of fibronectin has been described in plasma during experimental vascular injury and in patients with autoimmune vascular diseases, the aim of this study was also to verify the presence of a polymorphism of the glycoprotein in cryoglobulinaemic vasculitis. Twenty seven patients with essential mixed cryoglobulinaemia and 26 normal subjects were included in the study. Significantly reduced concentrations of plasma fibronectin, as assessed by ELISA, were found in patients when compared with controls (231.7 +/- 15.3 vs 316.1 +/- 16.6 mg/l, P less than 0.0002). In contrast, when affinity-purified plasma fibronectin from 10 patients with essential mixed cryoglobulinaemia and 8 healthy subjects were analysed by western blotting, employing a panel of five monoclonal antibodies to different regions of the molecule, no differences were observed between patients and controls, suggesting integrity of the glycoprotein in the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical significance of endothelial damage markers in essential mixed cryoglobulinemia.

Essential mixed cryoglobulinemia (EMC) is a rheumatic disorder characterized by widespread vasculitis. To better define the nature of the vasculitic process and to possibly outline assessment methods reliable for using in a clinical context, we studied plasma levels of three endothelial related peptides: fibronectin (FN), von Willebrand factor (vWF) and tissue plasminogen activator (t-PA), and those of thrombin-antithrombin III complexes (TAT) as markers of activation of the coagulation in 21 patients and in 16 controls. In EMC we found a picture consisting of reduced FN and increased vWF, t-PA, and TAT levels, suggesting a condition of endothelial cell damage with thrombin formation in vivo. Since we previously demonstrated the presence of chronic disseminated intravascular coagulation in these patients, we may assume that endothelial cells stressed by cryoprecipitation or stimulated by soluble mediators may be actively involved in the vasculitic process and possibly express procoagulant properties. This is a good example of the complex interplay existing between autoimmunity and coagulation mechanisms. We also suggest that FN, vWF, t-PA and TAT should be considered as additional clinical parameters when evaluating patients with EMC.

Symptoms of respiratory allergies are worse in subjects with coexisting food sensitization.

Food sensitization was evaluated in 78 subjects with respiratory allergies, both by skin tests with commercial and fresh allergens, and by specific IgE determination. On the basis of the presence or absence of the latter the population was divided into two groups. The group with food-specific IgE showed more severe features of respiratory allergy, including a greater number of positive skin tests and specific IgE determinations, more class 3 and 4 reactions, and more symptoms. The hypothesis that early food sensitization can predispose to severe inhalant allergy is discussed.

Chronic effects of transdermal nitroglycerin in stable angina pectoris: a within-patient, placebo-controlled study.

The efficacy of transdermal nitroglycerin patches, releasing 20 mg of active substance over a period of 24 h (TDN 20), was investigated in 10 patients with stable exercise-induced angina pectoris. The study was divided into 3 periods: the first part was an acute, within-patient, crossover, double-blind, placebo-controlled study, in which patients performed a cycloergometric exercise test 4 and 24 h after the application of the patches (TDN 20 or placebo). During the 2nd period, patients were given TDN 20, in single blind conditions, for 4 weeks and another exercise test was performed, on the last day, 4 and 24 h after patch application. Finally, after a one-day placebo wash-out, a second acute study similar to the first was performed. Four h after dosing, exercise duration to 1 mm ST segment depression was 441 s and 314 s (p less than 0.01) for TDN 20 and placebo, respectively (first acute study), 394 s for TDN 20 after chronic treatment (p less than 0.001 vs acute placebo) and 472 and 354 s (p less than 0.001) for TDN 20 and placebo, respectively (second acute study). No difference in exercise duration to 1 mm ST segment depression was found between TDN 20 and placebo, 24 h after administration, in any of the periods. Blood pressure significantly decreased and heart rate significantly increased 4 h after TDN dosing (in comparison with placebo) in both the acute studies, but no difference was observed after chronic TDN treatment. In conclusion, TDN 20 increases exercise tolerance 4 h after the application of both acute and chronic treatments.(ABSTRACT TRUNCATED AT 250 WORDS)