Clinical evaluation of disorganization during atrial fibrillation as a guide to radiofrequency ablation

Aim of this study was to investigate the spatial patterns of organization of fibrillation in the right atrium using bipolar recordings from a basket catheter. Study population consists of 17 patients with persistent atrial fibrillation (AF), selected a priori for low energy internal cardioversion. Organization was measured by the number of occurrences--i.e. the percentage number of points laying on the baseline--which has been demonstrated to match Wells' criteria for the classification of AF. Well-defined and stable patterns of organization characterize the electrical activity of the right atrium in these patients. The organization in the entire right atrium showed an individual rather than common distribution. This may have implications in the choice of regions candidate for ablation.

Non-genomic stimulation of tyrosine phosphorylation cascades by 1,25(OH)(2)D(3) by VDR-dependent and -independent mechanisms in muscle cells

Studies with different cell types have shown that modulation of various of the fast as well as long-term responses to 1,25(OH)(2)D(3) depends on the activation of tyrosine kinase pathways. Recent investigations of our laboratory have demonstrated that 1,25(OH)(2)D(3) rapidly stimulates in muscle cells tyrosine phosphorylation of PLC-gamma and the growth-related proteins MAPK and c-myc. We have now obtained evidence using antisense technology indicating that VDR-dependent activation of Src mediates the fast stimulation of tyrosine phosphorylation of c-myc elicited by the hormone. This non-genomic action of 1,25(OH)(2)D(3) requires tyrosine phosphorylation of the VDR. Immunoprecipitation under native conditions coupled to Western blot analysis revealed 1,25(OH)(2)D(3)-dependent formation of complexes between Src and the VDR and c-myc. However, the activation of MAPK by the hormone was only partially mediated by the VDR and required in addition increased PKC and intracellular Ca(2+). Following its phosphorylation, MAPK translocates into the nucleus where it regulates c-myc transcription. Altogether these results indicate that tyrosine phosphorylation plays a role in the stimulation of muscle cell growth by 1,25(OH)(2)D(3). Data were also obtained involving tyrosine kinases and the VDR in hormone regulation of the Ca(2+) messenger system by mediating the stimulation of store-operated calcium (SOC; TRP) channels. Congruent with this action, 1,25(OH)(2)D(3) induces a rapid translocation of the VDR to the plasma cell membrane which can be blocked by tyrosine kinase inhibitors. Of mechanistic relevance, an association between the VDR and TRP proteins with the participation of the scaffold protein INAD was shown.

Iron, hepatic stellate cells and fibrosis in chronic hepatitis C

BACKGROUND/AIMS

In patients with chronic hepatitis C, hepatic iron concentration correlates with liver fibrosis. However, it is not clear whether this correlation merely reflects the presence of more active disease, or iron exacerbates chronic hepatitis C virus (HCV)-induced damage through activation of hepatic stellate cells and regeneration of hepatocytes.

MATERIALS AND METHODS

We studied 72 HCV-positive patients, staged according to the Ishak's score system. We measured hepatic iron concentration with spectrophotometry and evaluated the number of hepatic stellate cells (using monoclonal antibody against alpha smooth muscle actin) and proliferating hepatocytes (using monoclonal antibody against Ki67). Iron and ferritin serum levels were also determined.

RESULTS

Hepatic iron concentration correlated statistically with ferritin serum level (r = 0.59, P < 0.001), with grading (r = 0.47, P < 0.001) and staging (r = 0.51, P < 0.001) scores for chronic hepatitis in the whole group of patients. Hepatic iron concentration correlated positively with stellate cell number (r = 0.55, P = 0.004) and Ki67-positive hepatocyte number (r = 0.36, P = 0.08) in patients with chronic hepatitis C and low grading score (< 3).

CONCLUSIONS

In patients with chronic hepatitis C and low grading score, hepatic iron could play a role in the activation of hepatic stellate cells and in the progression of fibrosis.

Long term treatment of pulmonary arterial hypertension with beraprost, an oral prostacyclin analogue

OBJECTIVE

To evaluate the effects of one year's treatment with beraprost, an orally active prostacyclin analogue, in patients with severe pulmonary hypertension.

PATIENTS

13 patients with severe pulmonary hypertension. This was primary in nine, thromboembolic in three, and caused by Eisenmenger syndrome in one.

METHODS

All patients underwent right heart catheterisation. Mean (SD) right atrial pressure was 5 (3) mm Hg, mean pulmonary artery pressure was 48 (12) mm Hg, cardiac index was 2.6 (0.8) l/min/m(2), and mixed venous oxygen saturation was 68 (7)%. Beraprost was started at the dose of 20 microgram three to four times a day (1 microgram/kg/day), increasing after one month to 40 microgram three to four times a day (2 microgram/kg/day), with further increases of 20 microgram three to four times a day in case of clinical deterioration.

MAIN OUTCOME MEASURES

New York Heart Association (NYHA) functional class, exercise capacity measured by distance walked in six minutes, and systolic pulmonary pressure (by echocardiography) were evaluated at baseline, after one month's treatment, and then every three months for a year.

RESULTS

After the first month of treatment, NYHA class decreased from 3.4 (0.7) to 2.9 (0.7) (p < 0.05), the six minute walking distance increased from 213 (64) to 276 (101) m (p < 0.05), and systolic pulmonary artery pressure decreased from 93 (15) to 85 (18) mm Hg (NS). One patient died after 40 days from refractory right heart failure, and another was lost for follow up at six months. The 11 remaining patients had persistent improvements in functional class and exercise capacity and a significant decrease in systolic pulmonary artery pressure in the period from 1-12 months. Side effects were minor.

CONCLUSIONS

Oral administration of beraprost may result in long lasting clinical and haemodynamic improvements in patients with severe pulmonary hypertension.

Advanced glycation end product levels in eye lenses, aorta, and tail tendon in transplanted diabetic inbred Lewis rats

BACKGROUND

Pancreatic islet transplantation in diabetes, by restoring euglycemia, should in time correct the abnormal accumulation of advanced glycation end products (AGEs) over target tissues, thus delaying the development of late diabetic complications.

METHODS

Homologous islet transplantation was performed in inbred Lewis rats 15 days (TA), 4 months (TB), and 8 months (TC) after streptozotocin diabetes. Group TA was studied for 12 months and groups TB and TC were studied for 4 months after transplantation. Normal (N) and diabetic (D) rats formed the control groups. Metabolic control in the transplant (T) groups was evaluated by oral glucose tolerance test. Blood glucose, glycated hemoglobin, and body weight were determined in all groups. AGE levels were determined by spectrofluorometry in eye lens proteins and by ELISA in aortic and tail tendon collagen.

RESULTS

T groups showed normal oral glucose tolerance tests and metabolic parameters. The latter were altered in all D groups (P<0.005 to P<0.0001 versus N and T groups). AGEs were increased in the D groups (P<0.05 to P<0.001) versus the N groups. AGEs in the TA and TB groups were not different from those of the N groups but were significantly reduced (P<0.05 to P<0.001) when compared with those of the D groups. In the TC group, eye lens AGEs were significantly elevated (P<0.001) or significantly reduced (P<0.01) when compared with those of the N or D groups, respectively. Aortic collagen AGEs were elevated (P<0.01) by comparison with those of the N groups and not statistically different from those of the D groups. Tail tendon collagen AGE levels lay between those of the N and D groups, without reaching a statistical significance.

CONCLUSIONS

These results indicate that primary and early secondary (groups TA and TB) but not late secondary (group TC) islet transplantations are capable of blocking or reducing an abnormal accumulation of AGEs, thus confirming the importance of preventive transplantation therapies.

The influence of polymeric membrane surface free energy on cell metabolic functions

In membrane bioartificial organs using isolated cells, polymeric semipermeable membranes are used as immunoselective barriers, means for cell oxygenation and also as substrata for adhesion of anchorage-dependent cells. The selection of cytocompatible membranes that promote in vitro cell adhesion and function could be dependent on its membrane properties. In this study we investigated the physicochemical aspects of the interaction between the membrane and mammalian cells in order to provide guidelines to the selection of cytocompatible membranes. We evaluated the metabolic behavior of isolated liver cells cultured on various polymeric membranes such as the ones modified by protein adsorption. The physico-chemical properties of the membranes were characterized by contact angle measurements. The surface free energy of membranes and their different parameters acid (gamma+), base (gamma-) and Lifshitz-van der Waals (gammaLW) were calculated according to Good-van Oss's model. The adsorption of protein modified markedly both contact angle and membrane surface tension. In particular, membrane surface free energy decreased drastically with increased water contact angle. For each investigated membrane we observed that liver specific functions of cells improve on hydrophilic membrane surfaces. For all investigated membranes the rate of ammonia elimination increased with increasing of membrane surface free energy.

Parathyroid hormone activation of map kinase in rat duodenal cells is mediated by 3',5'-cyclic AMP and Ca(2+)

In a previous study, we demonstrated that parathyroid hormone (PTH) stimulates in rat duodenal cells (enterocytes) the phosphorylation and activity of extracellular signal-regulated mitogen-activated protein kinase (MAPK) isoforms ERK1 and ERK2. As PTH activates adenylyl cyclase (AC) and phospholipase C and increases intracellular Ca(2+) in these cells, in the present study we evaluated the involvement of cAMP, Ca(2+) and protein kinase C (PKC) on PTH-induced MAPK activation. We found that MAPK phosphorylation by the hormone did not depend on PKC activation. PTH response could, however, be mimicked by addition of forskolin (5-15 microM), an AC activator, or Sp-cAMP (50-100 microM), a cAMP agonist, and suppressed to a great extent by the AC inhibitor, compound Sq-22536 (0.2-0.4 mM) and the cAMP antagonist Rp-cAMP (0.2 mM). Removal of external Ca(2+) (EGTA 0.5 mM), chelation of intracellular Ca(2+) with BAPTA (5 microM), or blockade of L-type Ca(2+)-channels with verapamil (10 microM) significantly decreased PTH-activation of MAPK. Furthermore, a similar degree of phosphorylation of MAPK was elicited by the Ca(2+) mobilizing agent thapsigargin, the Ca(2+) ionophore A23187, ionomycin and membrane depolarization with high K(+). Inclusion of the calmodulin inhibitor fluphenazine (50 microM) did not prevent hormone effects on MAPK. Taken together, these results indicate that cAMP and Ca(2+) play a role upstream in the signaling mechanism leading to MAPK activation by PTH in rat enterocytes. As Ca(2+) and cAMP antagonists did not block totally PTH-induced MAPK phosphorylation, it is possible that linking of the hormone signal to the MAPK pathway may additionally involve Src, which has been previously shown to be rapidly activated by PTH. Of physiological significance, in agreement with the mitogenic role of the MAPK cascade, PTH increased enterocyte DNA synthesis, and this effect was blocked by the specific inhibitor of MAPK kinase (MEK) PD098059, indicating that hormone modulation of MAPK through these messenger systems stimulates duodenal cell proliferation.

Phenolic constituents and antioxidant activity of an extract of Anthuriumversicolor leaves

Fractionation of a methanolic extract of the leaves of Anthurium versicolor has resulted in the isolation of two main fractions, I and II. Both the extract and the fractions were assayed for their radical-scavenging activity by means of an in vitro test (bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical) and showed a significant radical-scavenging effect. Subsequent chromatographic fractionation of the most active fraction, II, has led to the isolation and characterization, as major constituents, of four new flavone glycosides, acacetin 6-C-[alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside] (1), acacetin 6-C-[beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside] (2), acacetin 6-C-[beta-D-apiofuranosyl-(1-->3)-beta-D-glucopyranoside] (3), and acacetin 8-C-[alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside] (4), as well as vitexin (apigenin-8-C-beta-D-glucopyranoside) and rosmarinic acid. The structures of 1-4 were determined using spectroscopic methods.

Mapping the organization of atrial fibrillation with basket catheters. Part II: Regional patterns in chronic patients

The aim of this study was to investigate the spatial patterns of organization of fibrillation in the right atrium using bipolar recordings from a basket catheter in a population of 17 patients with persistent AF. The number of occurrences (NO) (i.e., the number of points laying on the baseline) was used as an objective measure of organization. This parameter significantly matches Wells' criteria for the classification of bipolar recordings during AF. The anatomic correspondence of the splines with eight atrial regions (namely anterior free wall, lateral free wall, posterolateral free wall, posterior free wall, posterior atrial septum, atrial septum, tricuspid valve, and anterior tricuspid valve) was assessed by fluoroscopic projections and electrogram morphology. Each region was further divided into high, mid-high, mid-low, and low segments. It was observed that individual and well-defined patterns of organization characterize the electrical activity of the right atrium in patients with persistent AF. When observed over 10 minutes, these patterns are rather stable in time. In each patient, the NO measurements were significantly different in the various right atrium regions (P < 0.0001 for all patients, Friedman test). The NO averaged over the population was significantly different among the regions (P < 0.001, Kruskal-Wallis test), owing to a common disorganized pattern observed in the tricuspid valve and anterior tricuspid valve regions. When these regions were removed from the analysis, the differences among the remaining regions were not statistically significant (P = 0.77). In conclusion, the quantitative assessment of organization in the entire right atrium showed an individual rather than common distribution. This may have implications in the choice of regions candidate for ablation.

Left ventricular diastolic function in systemic sclerosis

OBJECTIVE

To assess left ventricular diastolic function in patients with systemic sclerosis (SSc) and to verify if a "primary" diastolic dysfunction might exist.

METHODS

In total 124 patients and 41 healthy subjects underwent complete echocardiographic examination. The following pulsed wave Doppler variables were evaluated: peak velocity during early filling (E), peak velocity during late atrial filling (A), E/A ratio, and early filling deceleration time.

RESULTS

Seventy-seven patients (62.1%) had conditions potentially affecting left ventricular diastolic function (Group A) and 47 patients (37.9%) formed a homogeneous group without cardiac involvement or other causes of abnormal diastolic function (i.e., systemic and/or pulmonary hypertension, ventricular hypertrophy, pericardial disease, systolic dysfunction, valvular heart disease, coronary artery disease) (Group B). The entire SSc population and Group A showed significant differences in the Doppler variables of diastolic function compared to the control group. No significant differences were found between Group B and controls.

CONCLUSION

In patients with SSc, left ventricular diastolic dysfunction was found only in patients with conditions potentially affecting left ventricular diastolic function. In patients without conditions potentially affecting left ventricular diastolic function no differences were seen in comparison with controls. SSc does not seem to cause "primary" diastolic abnormalities.

Mapping the organization of atrial fibrillation with basket catheters. Part I: Validation of a real-time algorithm

The authors proposed a real-time algorithm to quantify AF organization from multielectrode basket catheter (MBC) recordings. The algorithm is based on a fast method to estimate the number of points along the baseline of a single bipolar electrogram (number of occurrences, NO). They have already proven this parameter to be effective at discriminating AF organization according to Wells' criteria. Special attention has been paid to ventricular far-field artifacts, as they proved they can significantly bias the degree of organization. To fulfill the constraints of a real-time application, a ventricular blanking procedure was implemented and validated. Bipolar electrograms were obtained from MBC in the right atrium in 17 informed patients with chronic AF. The results of NO computations were displayed as three-dimensional color-coded maps of organization by interpolating the measurements obtained at the locations of catheter bipoles. The proposed method allows real-time estimation of the organization of the atrial electrograms according to Wells' criteria. The estimation has a temporal resolution of 2 seconds, is robust to far-field ventricular artifacts, and interpolates the data available to furnish a single global map of the entire atrium. Further studies devoted to the analysis of individual and common patterns of the regional distribution of AF organization are needed to assess the usefulness of this approach for electrophysiological studies and therapeutic applications.

Congestive heart failure in hypertensive patients with normal systolic function and dynamic left ventricular outflow obstruction

BACKGROUND

Hypertensive patients with left ventricular hypertrophy and normal systolic function can develop congestive heart failure refractory to conventional drug therapy with digoxin, diuretic, and vasodilators.

METHODS

We studied 8 patients with a history of systemic hypertension (6 females and 2 males, mean age 69+/-6 years), affected by New York Heart Association (NYHA) class IV congestive heart failure notwithstanding conventional drug therapy with digoxin, diuretic, and vasodilators. After clinical history and physical examination, blood chemistry including cardiac enzymes, arterial blood gases, chest roentgenogram, standard 12-lead ECG, and complete echocardiographic study were performed in all patients.

RESULTS

In all cases, a left ventricle with increased wall thickness, normal cavity size, and normal or supernormal systolic function was shown. All patients had left ventricular systolic dynamic obstruction, with peak gradient between 36 and 130 mmHg (mean 83+/-31). After having stopped treatment with nitrates, digoxin, and diuretics, drug therapy with calcium channel antagonists or beta-blockers was started, and rapid clinical improvement with disappearance of left ventricular outflow obstruction was observed.

CONCLUSIONS

Sometimes, a distinction between several forms of heart failure is clinically impossible. However, when conventional therapy is not effective in patients with longstanding history of systemic hypertension and ECG signs of left ventricular hypertrophy, diastolic heart failure and/or dynamic left ventricular obstruction should be suspected. Thus, an early echocardiographic study should be performed.

Systemic sclerosis (scleroderma). A case of recovery of cardiomyopathy after vitamin E treatment

A 60-year-old woman with systemic sclerosis, systemic hypertension, and chronic renal failure, presented with clinical manifestations of heart failure. An echocardiogram showed a mildly dilated left ventricle and global hypokinesis. A six-month treatment including reduced sodium intake, furosemide, and nifedipine did not change the clinical and instrumental findings. Casually, vitamin E (600 mg daily) was added. After 6 months, clinical manifestations of heart failure were disappeared and the echocardiogram showed a normally-sized left ventricle with normal wall motion.

Cardiac involvement in patients with Wegener's granulomatosis

Wegener's granulomatosis (WG) is a systemic necrotizing vasculitis, which could potentially affect any organ system. However, there have only been a few reports on cardiac involvement. We described the echocardiographic findings in nine patients affected by WG. A complete M-mode, two-dimensional, Doppler and color-Doppler transthoracic echocardiogram was performed in nine patients (seven females and two males) affected by WG. In each patient, cardiac abnormality, for example, valvular damage, left ventricular global systolic dysfunction, or pericardial effusion, was detected. In particular, heart valve disease was found in eight patients, and in three cases, aortic valve insufficiency, which was severe enough to require surgical valve replacement, was observed. Cardiac involvement in patients with WG is common. In particular, there is a high frequency of aortic valve abnormalities. Thus, an echocardiographic study should be routinely performed.

Spondylodiscitis and infective endocarditis: case studies and review of the literature

STUDY DESIGN

This study evaluated the association between infective endocarditis and infective spondylodiscitis and its clinical features.

OBJECTIVES

To report case studies of patients with spondylodiscitis complicating infective endocarditis.

SUMMARY OF BACKGROUND DATA

Early diagnosis of infective endocarditis as the source of the spondylodiscitis is often difficult because clinical and radiologic patterns are similar to those present in spondylodiscitis alone.

METHODS

The case records of the patients with infective endocarditis admitted to our Department from 1991-1998 were reviewed. The diagnosis of spondylodiscitis was made on the basis of clinical features and of typical radiologic signs.

RESULTS

Among 30 patients affected by infective endocarditis, three also were affected by spondylodiscitis. All patients fully recovered after appropriate antibiotic therapy.

CONCLUSIONS

In all patients with spondylodiscitis, infective endocarditis should be excluded, particularly in patients with a history of heart valve disease.

Pulmonary hypertension is associated with impaired exercise performance in patients with systemic sclerosis

OBJECTIVE

The aim of this study was to evaluate the exercise tolerance by expired gas analysis during stress test in patients with Systemic Sclerosis (SSc).

METHODS

Eighteen women (mean age 48.56+/-12.48 years) affected by SSc were studied. A complete echocardiographic examination including pulmonary artery systolic pressure estimation, pulmonary function tests, diffusion lung capacity for carbon monoxide (DLCO), and exercise test were performed. During exercise, breath-by-breath expired gas analysis was performed.

RESULTS

Seven patients (39%) had baseline pulmonary systolic hypertension (group A) and 11 patients (61%) did not (group B). Six patients had reduced DLCO values. Both maximal oxygen consumption (VO2max) and anaerobic threshold (VO2AT) values were markedly decreased compared to the predicted values. Seven of 18 patients were unable to complete a maximal exercise (5 of whom affected by pulmonary systolic hypertension). Group A patients showed reduced VO2max, VO2AT, and O2 pulse compared with patients with group B patients (p=0.004, 0.017, and 0.013, respectively); VO2max, VO2AT and O2 pulse were significantly correlated to baseline pulmonary artery systolic pressure.

CONCLUSIONS

An exercise intolerance in patients affected by SSc is present. Impairment of exercise performance is associated with pulmonary hypertension.

The stimulation of MAP kinase by 1,25(OH)(2)-vitamin D(3) in skeletal muscle cells is mediated by protein kinase C and calcium

In previous work we have demonstrated that the steroid hormone 1,25(OH)(2)-vitamin D(3) [1,25(OH)(2)D(3)] stimulates in skeletal muscle cells the phosphorylation and activity of the extracellular signal-regulated mitogen-activated protein (MAP) kinase isoforms ERK1 and ERK2. In the present study we evaluated the involvement of Ca(2+) and protein kinase C (PKC) on 1,25(OH)(2)D(3)-induced activation of MAP kinase. The hormone response was found to depend on PKC stimulation since it was attenuated by the PKC inhibitors calphostin C (100 nM) and bisindolylmaleimide I (30 nM) and PKC downregulation by prolonged treatment with the phorbol ester TPA (1 microM). Removal of external Ca(2+), chelation of intracellular Ca(2+) with BAPTA (5 microM), inhibition of phosphoinositide-phospholipase C (PLC) by neomycin, the calmodulin antagonist fluphenazine (50 microM) and the specific inhibitor of calmodulin kinase II, KN-62 (10 microM), significantly decreased 1,25(OH)(2)D(3)-activation of MAP kinase. In addition, the Ca(2+)-channel blocker verapamil (5 microM) suppressed hormone-induced MAP kinase activity in these cells. Furthermore, the Ca(2+)-mobilizing agent thapsigargin and the Ca(2+)-inophore A23187 paralleled the phosphorylation of MAP kinase observed with 1,25(OH)(2)D(3). Taken together, these results indicate that PKC and Ca(2+) are two upstream activators mediating the effects of 1,25(OH)(2)D(3) on MAP kinase in skeletal muscle cells.

Involvement of tyrosine kinase activity in 1alpha,25(OH)2-vitamin D3 signal transduction in skeletal muscle cells

In cultured chick skeletal muscle cells loaded with Fura-2, the tyrosine kinase inhibitors herbimycin A and genistein abolished both the fast inositol 1,4,5-trisphosphatedependent Ca(2+) release from internal stores and extracellular Ca(2+) influx induced by 1alpha, 25(OH)(2)-vitamin D(3) (1alpha,25(OH)(2)D(3)). Daidzein, an inactive analog of genistein, was without effects. Tyrosine phosphatase inhibition by orthovanadate increased cytosolic Ca(2+). Anti-phosphotyrosine immunoblot analysis revealed that 1alpha, 25(OH)(2)D(3) rapidly (0.5-10 min) stimulates in a concentrationdependent fashion (0.1-10 nm) tyrosine phosphorylation of several myoblast proteins, among which the major targets of the hormone could be immunochemically identified as phospholipase Cgamma (127 kDa), which mediates intracellular store Ca(2+) mobilization and external Ca(2+) influx, and the growth-related proteins mitogen-activated protein (MAP) kinase (42/44 kDa) and c-myc (65 kDa). Genistein suppressed the increase in phosphorylation and concomitant elevation of MAPK activity elicited by the sterol. Both genistein and the MAPK kinase (MEK) inhibitor PD98059 abolished stimulation of DNA synthesis by 1alpha,25(OH)(2)D(3). The sterol-induced increase in tyrosine phosphorylation of c-myc, a finding not reported before for cell growth regulators, was totally suppressed by the specific Src inhibitor PP1. These results demonstrate that tyrosine phosphorylation is a previously unrecognized mechanism involved in 1alpha,25(OH)(2)D(3) regulation of Ca(2+) homeostasis in hormone target cells. In addition, the data involve tyrosine kinase cascades in the mitogenic effects of 1alpha, 25(OH)(2)D(3) on skeletal muscle cells.

Primary aspergillosis of the larynx in a patient with Felty's syndrome

Herein we report the first case of primary aspergillosis of the larynx in a patient with Felty's syndrome. A 53-year-old man, a florist by profession, with a 12-year history of rheumatoid arthritis and on treatment with steroids, was admitted because of hoarseness, and intermittent fever of 2 weeks' duration. On admission, physical examination and laboratory data showed, among other findings, splenomegalia and neutropenia. At bone marrow examination, normal cellularity with mild dyserythropoiesis was observed. A fiberoptic laryngoscopy showed white plaques on both the true vocal cords. Both culture and microscopic examination of these lesions provided the diagnosis of invasive process by Aspergillus flavus. A computed tomography of the middle ears, paranasal sinuses, and chest was normal. Thus, primary aspergillosis of the larynx and Felty's syndrome was diagnosed, and the patient was successfully treated with granulocyte colony-stimulating factor and systemic antifungal agents. Felty's syndrome, corticosteroid use, and occupational risk probably rendered our patient susceptible to Aspergillus infection.

Automated classification of human atrial fibrillation from intraatrial electrograms

The assessment of the degree of organization and the classification of atrial fibrillation (AF) according to the types defined by Wells usually resorts to the visual inspection of bipolar intraatrial electrograms. The focus of this study was to test seven parameters aimed to quantify the degree of organization of the electrograms, and then to design a final classification scheme based on a multidimensional, minimum-distance analysis. The following parameters were tested: mean atrial period (AP) and its coefficient of variation (CV); number of points lying at the baseline (NO) and the Shannon entropy (EN) of the amplitude probability density function (APDF); depolarization width (F-WIDTH); and correlation waveform analysis (CWA) and electrogram bandwidth (BW). The signal database consisted in a set of 160 AF strips of Type I, II, and III AF, scored by an expert cardiologist (60 Type I, 40 Type II, 60 Type III) and further divided in a training set (60) and a test set (100). Strips were 6 seconds long and were recorded with 5-mm interspace bipolar catheters from electrically induced (n = 13) and chronic (n = 10) patients. A classification algorithm based on a minimum-distance (Mahalanobis distance) discriminant analysis was tested. Using a single parameter, the best discriminations were provided by NO, F-WIDTH, and CV. F-WIDTH was found strongly inversely correlated to NO (r = -0.90). Of all the two-parameter combinations, CV-NO provided the best classification: 92 of 100 segments were correctly classified with sensitivity > 90% and specificity > 92%. A further improvement was obtained by including BW as a third parameter (93/100 correctly classified). The use of more than three parameters not only failed to improve, but even degraded the classification.

Thyrotoxicosis, unstable angina and normal coronary angiogram

It is well known that thyrotoxicosis may elicit acute myocardial ischemia even in patients with angiographically normal coronary vessels. The involved mechanisms are not clearly defined although some hypothesis have been suggested. We report a case of a 54-year-old woman affected by Graves' disease with thyrotoxicosis which was referred to our Institute because of unstable angina. During hospitalization a two dimensional echocardiogram, performed during chest discomfort, showed left ventricular apical akinesis and impaired global systolic function. A subsequent coronary angiography revealed normal epicardial vessels. She was successfully treated with high-dose methimazole and propranolol and a repeat echocardiogram evaluation showed normalization of left ventricular systolic function. Six months later, because of the appearance of paroxysmal atrial fibrillation, the patient underwent total thyroidectomy and a substitutive therapy with L-T4 (100 micrograms/die) was started. The authors review the possible mechanisms involved in the pathogenesis of myocardial ischemia during thyrotoxicosis.

Reduction of advanced glycation end-product (AGE) levels in nervous tissue proteins of diabetic Lewis rats following islet transplants is related to different durations of poor metabolic control

Advanced glycation end-products (AGEs) are irreversible compounds which, by abnormally accumulating over proteins as a consequence of diabetic hyperglycaemia, can damage tissues and thus contribute to the pathogenesis of diabetic complications. This study was performed to evaluate whether restoration of euglycaemia by islet transplantation modifies AGE accumulation in central and peripheral nervous tissue proteins and, as a comparison, in proteins from a non-nervous tissue. Two groups of streptozotocin diabetic inbred Lewis rats with 4 (T1) or 8 (T2) months disease duration were grafted into the liver via the portal vein with 1200-1500 islets freshly isolated from normal Lewis rats. Transplanted rats, age-matched control and diabetic rats studied in parallel, were followed for a further 4-month period. At study conclusion, glycaemia, glycated haemoglobin and body weight were measured in all animals, and an oral glucose tolerance test (OGTT) performed in transplanted rats. AGE levels in cerebral cortex, spinal cord, sciatic nerve proteins and tail tendon collagen were measured by enzyme-linked immunosorbent assay (ELISA). Transplanted animal OGTTs were within normal limits, as were glycaemia and glycated haemoglobin. Diabetic animal AGEs were significantly higher than those of control animals. Protein AGE values were reduced in many transplanted animals compared to diabetic animals, reaching statistical significance in spinal cord (P < 0.05), sciatic nerve (P < 0.02) and tail tendon collagen (P < 0.05) of T1 animals. Thus, return to euglycaemia following islet transplantation after 4 months of diabetes with poor metabolic control reduces AGE accumulation rate in the protein fractions of the mixed and purely peripheral nervous tissues (spinal cord and sciatic nerve, respectively). However, after a double duration of bad metabolic control, a statistically significant AGE reduction has not been achieved in any of the tissues, suggesting the importance of an early therapeutic intervention to prevent the possibly pathological accumulation of AGEs in nervous and other proteins.

Flail tricuspid valve in a patient with history of stab chest wound

Cardiac sequelae of stab chest wounds may be various and dramatic, and the right ventricle is the most commonly injured chamber. Correct diagnosis of cardiac damage may be done up to many years after the trauma. We describe a rare case of isolated, unexpected flail tricuspid valve detected by transthoracic echocardiography in a young patient with remote history of stab chest wound.