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Biomedical subjects

A Finzi

Publications and source records attributed to A Finzi.

At least 19 recordsLinked to original sources

Net primary production of a forest ecosystem with experimental CO2 enrichment

The concentration of atmospheric carbon dioxide was increased by 200 microliters per liter in a forest plantation, where competition between organisms, resource limitations, and environmental stresses may modulate biotic responses. After 2 years the growth rate of the dominant pine trees increased by about 26 percent relative to trees under ambient conditions. Carbon dioxide enrichment also increased litterfall and fine-root increment. These changes increased the total net primary production by 25 percent. Such an increase in forest net primary production globally would fix about 50 percent of the anthropogenic carbon dioxide projected to be released into the atmosphere in the year 2050. The response of this young, rapidly growing forest to carbon dioxide may represent the upper limit for forest carbon sequestration.

Journal Article↗

Exercise-induced paroxysmal atrioventricular block during nuclear perfusion stress testing: evidence for transient ischemia of the conduction system.

BACKGROUND: Whether tachycardia-dependent paroxysmal AV block, an uncommon complication of exercise stress testing in patients with infranodal conduction disturbances, can result from acute ischemia of the conduction system is still speculative, and is based on post-hoc evidence of right coronary artery disease and abolition of block after coronary angioplasty. METHODS AND RESULTS: In two patients, from a database of 3000 undergoing nuclear exercise stress testing, transient paroxysmal AV block developed 1-4 minutes after the injection of the radionuclide agent. Nuclear perfusion imaging demonstrated stress-induced ischemia of the posteroseptal segments, which corresponds to the anatomical region of the His bundle, and perfusion recovery in the images obtained at rest. Angiography disclosed critical narrowing of the right coronary artery in both cases. CONCLUSION: Nuclear myocardial perfusion imaging provides noninvasive evidence that transient ischemia of the posteroseptal segment, anatomically corresponding to the His bundle, can result in paroxysmal AV block in patients with severe right coronary artery and chronic infranodal conduction disturbances. The demonstration of the underlying pathophysiological mechanism is useful for selecting the most effective treatment strategy.

Acute Disease↗

A short-term trial of tacrolimus ointment for atopic dermatitis. European Tacrolimus Multicenter Atopic Dermatitis Study Group.

BACKGROUND: Tacrolimus (FK 506) is an effective immunosuppressant drug for the prevention of rejection after organ transplantation, and preliminary studies suggest that topical application of tacrolimus is effective in the treatment of atopic dermatitis. METHODS: We conducted a randomized, doubleblind, multicenter study that compared 0.03 percent, 0.1 percent, and 0.3 percent tacrolimus ointment with vehicle alone in patients with moderate to severe atopic dermatitis. The ointment was applied twice daily to a defined, symptomatic area of 200 to 1000 cm2 of skin for three weeks. The primary end point was the change in the summary score for erythema, edema, and pruritus between the first and last days of treatment. RESULTS: After three weeks of treatment, the median percentage decrease in the summary score for dermatitis on the trunk and extremities was 66.7 percent for the 54 patients receiving 0.03 percent tacrolimus, 83.3 percent for the 54 patients receiving 0.1 percent tacrolimus, 75.0 percent for the 51 patients receiving 0.3 percent tacrolimus, and 22.5 percent for the 54 patients receiving vehicle alone (P<0.001). The results for the face and neck were similar. The differences among the three tacrolimus groups were not statistically significant. A sensation of burning at the site of application was the only adverse event that was significantly more frequent with tacrolimus than with vehicle alone (P<0.001). Throughout the study, most patients in all three tacrolimus groups had blood concentrations of tacrolimus below 0.25 ng per milliliter. The highest concentration was 4.9 ng per milliliter, which was reported in the group receiving 0.3 percent tacrolimus. CONCLUSIONS: The short-term application of tacrolimus ointment is effective in the treatment of atopic dermatitis, with the sensation of burning being the main side effect.

Administration, Cutaneous↗

Plasma neuropeptide levels in psoriasis.

The immune system is important in the pathogenesis of psoriasis and emotional stress has precipitated psoriasis in many patients. Neuropeptides, alpha-Melanocyte stimulating hormone (alpha-MSH), beta-endorphin, met-enkephalin and substance P (SP) act as immunomodulators, and their secretion increases during periods of stress. To see whether these neuropeptides themselves might be related to psoriasis and/or to the aggressiveness of the disease, we evaluated the plasma neuropeptide levels in 13 patients with active psoriasis (patients with new lesions and/or pre-existing lesions that had become larger during the month before the study), in 11 patients with stable psoriasis and in 10 healthy controls. Plasma concentrations of neuropeptides were evaluated by RIA (immunoradiometric assay for beta-endorphin). Data were compared by the Student t-test for unpaired data. There were no significant differences between the plasma levels of any of the neuropeptides between active psoriatic patients and stable psoriatic patients, nor between the plasma levels of neuropeptides of psoriatic patients and those of control subjects. It seems unlikely that circulating neuropeptide levels are of primary importance in the manifestation of the psoriatic skin lesions.

Adult↗

[Combination of transesophageal atrial pacing and echo-dipyridamole test in the diagnosis of coronary disease in patients with suspected angina pectoris and negative exercise test].

BACKGROUND: Echo-dipyridamole test is an useful tool for non-invasive demonstration of inducible myocardial ischemia in patients with coronary artery disease, its sensitivity being consistently higher as compared with classic exercise stress testing. However, in patients with single vessel who often perform a normal or borderline stress test, even the sensibility of echo-dipyridamole test is comparatively reduced. METHODS: In 19 patients with clinically suspected angina (effort-related in 4, at rest in 8, mixed in 7) and normal exercise stress test, standard echo-dipyridamole test was performed. Thereafter, rapid atrial pacing, a procedure associated with a sharp increase of myocardial oxygen consumption, was performed by means of a transoesophageal catheter during the proceeding 5 min and during 4 min of repeated dipyridamole 0.56 mg/kg infusion. RESULTS: Standard echo-dipyridamole test induced ventricular wall motion abnormalities in 3 patients (one with borderline exercise stress test), whereas repeated pacing-sensitized procedure obtained wall motion abnormalities (apical, septal and lateral) in the same and in 4 additional patients. Coronary angiography demonstrated > 70% stenosis in 8/19 patients (single vessel disease in 5), 7 of whom had been correctly recognized by pacing-dipyridamole test; therefore, sensitivity of the latter as compared with standard dipyridamole test was 87% and 37% respectively. The anatomic correlation of induced wall motion abnormalities with coronary arterial stenosis was demonstrated in all cases. Specificity was 100% with both methods. CONCLUSIONS: Although limited by its restricted patient population, this study suggests that atrial pacing, performed via transoesophageal catheter, can significantly improve the positive predictive value of echo-dipyridamole test in coronary artery disease. By means of this simple procedure, the possibility of non invasively diagnosing even single vessel stenosis in patients with inconclusive exercise stress testing can be significantly improved.

Adult↗

Family history, smoking habits, alcohol consumption and risk of psoriasis.

We have conducted a multicentre case-control study to assess the epidemiological importance of previously suggested risk factors for psoriasis, including family history of the disease, smoking and alcohol consumption. Newly diagnosed psoriatics, with a history of skin manifestations no longer than 2 years were eligible as cases; as controls we selected subjects with newly diagnosed dermatological conditions other than psoriasis. Interviews were performed by trained medical investigators using a structured questionnaire. Two-hundred and fifteen cases, aged 16-65 years (median age 38), and 267 controls, aged 15-65 years (median age 36), were interviewed and included in the analysis. Family history was a risk factor for psoriasis; the multiple logistic regression (MLR) adjusted-odds ratio was 18.8 (95% confidence interval 6.4-54.8) for a history in parents, and 3.2 (95% confidence interval 1.5-6.6) for a history in siblings. The risk of psoriasis was higher for current smokers than for those who had never smoked. The MLR adjusted odds ratio was 2.1 (95% confidence interval 1.1-4.0) for people smoking 15 cigarettes or more per day. The risk of psoriasis was higher for alcohol drinkers: compared with teetotallers the MLR adjusted-odds ratios were 1.3 (95% confidence interval 0.8-2.3) for subjects drinking one or two drinks/day and 1.6 (95% confidence interval 0.9 to 3.0) for those drinking three or more. However, the trend in risk was not statistically significant. Our study confirms the role of family history in psoriasis and provides some evidence of a dose-response relationship for an association between smoking habits and psoriasis.

Adolescent↗

A double-blind crossover comparison of flecainide and slow-release mexiletine in the treatment of stable premature ventricular complexes.

In 24 patients with stable premature ventricular contractions (PVCs) greater than or equal to 100/h, Lown class greater than or equal to 2 the relative anti-arrhythmic efficacy of flecainide 150 mg twice daily and slow-release mexiletine 360 mg twice daily was evaluated in a double-blind placebo-controlled randomized crossover study. All the patients had normal ventricular function. Criteria of efficacy were: reduction greater than or equal to 70% of PVCs or reduction greater than or equal to 50% with abolition of Lown class greater than 2 arrhythmias or suppression of non-sustained ventricular tachycardias (nSVT). Twenty-two patients completed the study protocol. The placebo phases showed comparable results and no carry over effect. The criteria of efficacy were fulfilled in 20 of the 22 patients (91%) on flecainide and in 12 of the 22 (55%) on mexiletine. The absolute reductions of PVCs, couplets and nSVT obtained on flecainide and mexiletine, in comparison to the placebo, were statistically significant (p less than 0.01 for flecainide, p less than 0.05 for mexiletine). Flecainide was superior to mexiletine in overall PVC reduction (p less than 0.05). In the 17 patients with couplets the reduction obtained with flecainide was superior to mexiletine (p less than 0.05). Both drugs were highly effective on nSVT. At steady state, the mean plasma levels of both drugs were within the range of clinical efficacy. The drugs were well tolerated and no patient withdrew because of side-effects. It was concluded that at the dosages employed flecainide was superior to mexiletine in reducing premature ventricular contractions and in abolishing couplets. The efficacy of both drugs for non-sustained ventricular tachycardias was comparable. Both drugs were highly effective by comparison with the placebo.

Cardiac Complexes, Premature↗

[Therapy and prevention of atrial fibrillation].

In the last decade, broader insights into the mechanisms and clinico-prognostic significance of atrial fibrillation have prompted a dramatic shift in the clinician's decision making process in terms of treatment and prevention of this common rhythm disturbance. In fact, evidence of short- or long-term untoward effects on cardiac function and the risk of cerebrovascular accidents, together with a much wider therapeutic armamentarium, form the rationale for the present far more aggressive attitude, aiming at restoring sinus rhythm in all patients in whom an even weak chance exists. The newer class IC (flecainide, propafenone) and class III (amiodarone, sotalol) antiarrhythmic agents are widely and successfully utilized to restore and to maintain sinus rhythm, with significant advantages in comparison with classic quinidine derivatives in terms of efficacy and patient compliance, as demonstrated in clinical controlled trials. Moreover, calcium channels blocking agents as verapamil and diltiazem have been demonstrated more effective than digitalis in the limitation of ventricular rate in patients with chronic atrial fibrillation. Although the advantages of long-term anticoagulation and/or antiaggregation in patients with atrial fibrillation are still being widely investigated at the present time, data obtained in the last years favoured a wider use of this treatment. Many non-pharmacologic interventions have been shown as dramatically effective in particular aspects of atrial fibrillation. Permanent atrial or atrioventricular pacing, alone or in association with antiarrhythmic drugs, has come out as first choice option in patients with bradycardia-tachycardia syndrome. Transcatheter ablation and antiarrhythmic surgical techniques are more and more widely utilized with increasing success in cases refractory to conventional approaches.

Anti-Arrhythmia Agents↗

[His bundle block 2:1 during paroxysmal supraventricular tachycardia involving an occult accessory atrio-His pathway].

A high degree AV block during paroxysmal supraventricular tachycardia is an uncommon and short-lasting finding in patients with intranodal re-entry circuits. The AV block is the result of temporary inadequacy of the infranodal conduction system--which is not part of the circuit--to cope with the sudden increase in heart rate in terms of refractory periods and conduction velocity. In a patient with paroxysmal reciprocating tachycardia at a very high rate (230-250 bpm), 2:1 intra-hisian AV block was constantly observed after arrhythmia initiation by atrial extrastimuli. This persisted for 1-4 minutes and then progressively subsided passing through a period of 3:2 intra- infra-hisian AV block until it reached 1:1 conduction with transient left bundle branch block. The latter occasionally disappeared as result of retrograde activation of the area of functional anterograde block and of subsequent noncompensatory pause, following a premature ventricular depolarization. Tachycardia-dependent AV block was abolished by verapamil and flecainide, because of lengthening of the tachycardia cycle length. Functional and electropharmacological features of retrograde conduction were consistent with an extranodal concealed atrio-hisian accessory pathway acting as the retrograde limb of the re-entry circuit. Moreover, His bundle electrogram was prolonged and polyphasic even in sinus rhythm. Therefore, tachycardia-dependent advanced AV block can occur not only in truly intranodal re-entry but also in very fast atrio-hisian re-entry tachycardias with evidence of transient impairment of intra-hisian conduction, distal to the insertion of the accessory pathway. Localized morphofunctional pathological changes in the His bundle are probably involved in the mechanism of this uncommon pattern.

Bundle of His↗

[Clinical framework of psoriatic arthropathy. Proposal of an evaluation protocol].

Psoriatic arthropathy is an inflammatory seronegative arthritis characterized by an involvement of peripheral or axial joints in association with psoriasis. In this study the clinical features of both skin and joints have been observed simultaneously by a rheumatologist and a dermatologist. We have finally proposed a clinical protocol based on PASI to evaluate psoriasis and on a simple subset classification to estimate joint involvement.

Adolescent↗

Evaluation of skin irritation and contact sensitizing potential of fenticonazole.

A double blind, randomized clinical trial was performed on twelve healthy volunteers to evaluate the irritation potential of fenticonazole 2% cream (Lomexin) and spray versus micomazole 2% cream and econazole 1% spray. The contact-sensitizing potential of the two fenticonazole preparations was also investigated. There was no evidence of irritation after the treatments with fenticonazole cream, its excipients, miconazole cream and fenticonazole spray excipients, whereas signs of irritation were observed in four cases after treatment with the spray formulations (two after fenticonazole, two after econazole). The contact-sensitizing test was performed only with fenticonazole 2% cream and spray. Neither spray nor cream formulation of fenticonazole showed evidence of sensitization in any of the twelve subjects.

Adult↗

Plasma melatonin levels in psoriasis.

Melatonin is synthesized and secreted by the pineal gland. A daily rhythm of melatonin secretion, with high plasma values during the dark period, has been found in all vertebrates studied so far. In psoriatics, several hormones, including GH and prolactin, have altered chronobiology, and some studies in humans suggest that melatonin affects the levels of GH and prolactin. We investigated circadian melatonin rhythm in 13 male psoriatics and 13 healthy males with an RIA specific for measuring the hormone in plasma. Samples were taken at 6 a.m., 8 a.m., 12.00, 4 p.m., 8 p.m. and 2 a.m. Differences in (mean +/- SD) plasma melatonin levels were analysed by Student's t-test. Our results show that psoriatic patients had lost the nocturnal peak and usual circadian rhythm of melatonin secretion. Levels of melatonin were significantly lower than in controls at 2 a.m., and higher at 6 and 8 a.m. and at 12 noon. Further investigations of this disorder of melatonin secretion in psoriasis are needed to understand its significance.

Adult↗

Antibodies to cardiac Purkinje cells: further characterization in autoimmune diseases and atrioventricular heart block.

We confirmed the occurrence of IgG antibodies reacting with ox cardiac conducting tissue in the serum of some human subjects. These antibodies failed to react with all ox cardiac conducting tissue cells; they reacted only with the cells defined as Purkinje cells. Having checked 352 sera, we found that the prevalence of antibodies to Purkinje cells was 11% in normal subjects (no correlation with sex and age), 14% in systemic lupus erythematosus, 21% in rheumatoid arthritis, 18% in progressive systemic sclerosis, and 23% in Sjögren syndrome. In 50 patients with permanent pacemakers for chronic non-postinfarction atrioventricular (AV) block the prevalence was 30% (P = 0.008). In a selected set of 29 patients with clinically idiopathic AV block located at or below the level of the His bundle the prevalence was 34.5% (P = 0.006). The possible role of anti-Purkinje cell antibodies in autoimmune damage of cardiac conduction tissue is discussed.

Adolescent↗

Permanent form of junctional reciprocating tachycardia involving an atrio-hisian accessory pathway: electrophysiologic and histologic correlations.

We present clinical, electrophysiologic and morphologic correlations of a patient with a permanent form of junctional reciprocating tachycardia, who died from a lung tumor. At electrophysiologic study, the tachycardia circuit was suspected to involve an atrio-Hisian accessory pathway antegradely and the AV node retrogradely; a ventriculo-atrial accessory pathway was excluded. Pathologic examination revealed a right-sided atrio-Hisian accessory pathway and an area of abnormal dispersion in the distal His bundle fibers. This case is consistently different from another previously reported case in which a concealed, serpiginous, septal atrioventricular accessory pathway was demonstrated by anatomic examination. Thus, different substrates seem to be responsible for the permanent form of junctional reciprocating tachycardia.

Aged↗

Long-term prognostic significance and electrophysiological evolution of intraventricular conduction disturbances complicating acute myocardial infarction.

Fifty-nine patients with post-infarctional, isolated intraventricular conduction disturbances (IVCD) who survived the acute stage of myocardial infarction were followed up after hospital discharge for a mean period of 11.4 +/- 4.8 months. Fourteen patients (24%) had HV interval prolongation (greater than 55 ms) during AMI (group A), and 45 patients had normal HV intervals (76%, group B). His bundle recordings were repeated during follow-up in 48 survivors after a mean period of 7.2 +/- 0.7 months. Infranodal conduction delay in the acute stage of infarction was correlated with a higher incidence of heart failure during AMI (78% of patients in group A vs 22% in group B, p less than 0.001), and with higher rate of cardiac mortality during follow-up (50% in group A vs 13% in group B, p less than 0.01). Survivors of group A showed a higher functional NYHA class, a higher incidence of CHF, and a higher prevalence of complex ventricular arrhythmias at Holter monitoring. No statistically significant difference in late sudden death was evident between the two groups of patients, and the global incidence of late AV block was 2%. At repeat His bundle recording no significant change (greater than 5 ms) in HV interval could be demonstrated in comparison to the acute phase recording, neither in patients with prolonged nor in patients with normal HV time. We conclude that HV prolongation in patients with isolated, post-infarctional IVCD is correlated with a worse prognosis, both during acute infarction and during the follow-up period, which presumably reflects wider anatomic damage in comparison to patients with normal HV time. The low incidence of late AV block and the electrophysiological demonstration of the stability of infranodal conduction several months after AMI indicate that these patients do not require permanent prophylactic pacing after acute myocardial infarction.

Adult↗