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Abstract Humic susbtances (HS) are increasingly applied as biostimulants in agriculture, though their mechanism of action is not yet completely understood due to their complex and heterogeneous composition. Here, we isolated thirteen different humic and fulvic acids from different sources, such as soils, composts, peat, leonardite and lignite, and characterized the distribution of their carbon components by 13C-CPMAS–NMR spectroscopy. Callus of Pinus Laricio, as a model plant species, was treated with different humic extracts and its growth and content of carbohydrates, phenols, and enzyme related to the nitrogen metabolism (invertase, glutamine synthetase, glutamate synthase, phosphoenoly pyruvate carboxylase, malate dehydrogenase) and stress resistance (catalase) were monitored. While a multivariate statistical analysis of NMR results well-separated the HS characteristics based on their origin, humic materials generally increased callus growth, as expected, with largest effects being exerted by the mostly polar humic acids from composts. However, the rest of measured parameters were not linearly related to hydrophobicity and aromaticity of humic isolates as well as their origin, but their conformational dynamics had to be advocated to explain their effects on callus cellular components. This work confirms that HS of various origin can act as sustainable biostimulants of plant growth, though the comprehension of their effects on plants biochemical activities requires further research and additional understanding of their molecular composition and conformational behaviour. Graphical Abstract

Two lignosulfonate-humates (a and b), derived by an industrial process from lignin, were chemically characterized and their effects on maize plants in terms of growth, nitrogen metabolism and photosynthesis were investigated. The biological effects of lignosulfonate humates were compared with those induced by a humic acid extracted from leonardite in order to better understand the complexity of their biological effects. Our results displayed that both lignosulfonate-humates (a and b) had a hormone-like activity and increased root and leaf growth. Moreover, all treatments increased the content of chlorophyll, glucose and fructose and enhanced the activity of Rubisco, glutamine-synthetase and glutamate-synthase. The observed intense biological activity indicated that lignosulfonate-humates and leonardite humic acid had a positive role on photosynthetic process of maize plants. In the light of these results, lignosulfonate-humates may be used as biostimulants to increase crop yield.

The aim of this study is to describe personal experience in the intensive management of patients with severe diabetes undergoing pancreas transplantation.Clinical records of subjects consecutively undergoing an isolated or combined pancreas transplant have been examinated.During the considered period, 10 patients received an isolated pancreas transplant and 43 a simultaneous kidney-pancreas transplantation (SPKT), including 6 using a kidney from a living donor. The mean stay in the Intensive Care Unit (ICU) was 4.7 days: 52 patients (98.2%) were transferred to the Surgical Department, whereas one (1.8%) belonging to the SPKT group died with a non-functioning graft. Ten patients (18.6%) were re-admitted because of the onset of late complications, including one SPKT who died of sudden cardiac death with functioning grafts. Arterial hypertension appeared in 51% of the recipients, and 5.6% experienced at least one hypotensive episode. Cardiac rhythm alterations were diagnosed in 5 subjects (9.4%), and myocardial ischemia in 9 (17%).Pancreas transplantation is a therapeutic option that can improve patients' quality of life by also slowing down the evolution of diabetes; however, it is important to bear in mind the associated risks. The best results are obtained in patients in whom the disease has not already seriously impaired the function of the various target organs.

Fifteen patients who underwent kidney transplant were studied in order to evaluate the effects of CyA on the gastrointestinal hormonal pattern. Eight patients followed traditional therapy while seven were treated with CyA. The basal gastrinemia values were high only in those patients treated with CyA. This might be due to: an increase in hormone secretion and/or release; a decreased hormone elimination probably due to nephro-hepatic toxicity of CyA; an increase in prostaglandins, caused by CyA, which inhibit secretion of gastri acids.

A clinical series of cysts and fistulas of the thyroglossal tract has been examined. Clinical aspects of this pathology and the results obtained with surgical treatment are compared with reported data.

H2-receptor antagonists, such as cimetidine (C), ranitidine (R) and famotidine (F) seem to be effective in the prevention and treatment of stress ulcer in transplant recipients receiving cyclosporin A (CyA). The aim of this study was to detect the possible synergistic nephro- and hepato-toxicity of these drugs, assaying the serum creatinine (SC), ALT, AST levels, and the histological features of 45 young male Sprague-Dawley rats, divided into nine groups of five rats each. After 10 days of treatment the results showed: (i) serum CyA levels were increased in the group receiving daily CyA (5 mg/kg) + R(5 mg/kg) (2430 +/- 403 ng/ml; p less than 0.05 vs. controls) and in the group receiving daily CyA (5 mg/kg) +/- C (10 mg/kg) (2440 +/- 265 ng/ml; p less than 0.01 vs. controls); (ii) ALT and AST levels were increased in this latter group (ALT 223 +/- 133 UL, AST 114.67 +/- 39 UL; p less than 0.01 vs. controls); (iii) SC levels were normal; and (iv) steatosis of the liver was observed in these two groups. These findings suggest that C and R, but not F, may inhibit the hepatic cytochromes P-450 which are involved in the oxidative metabolism of the drugs. Furthermore, the high serum CyA levels seem to play a major role in the appearance of biochemical and histological damage to the liver.

A retrospective study of 28 cases of thymoma classified according to Marino and Müller-Hermelink (cortical, medullary, mixed common, mixed with cortical predominance, mixed with medullary predominance thymoma) was undertaken to determine the existence of correlations between histology and clinical behavior. Cortical thymoma was observed in 11 cases (39.2%), mixed common thymoma in 9 (32.1%), mixed with cortical predominance in 5 (18%), and medullary thymoma in 3 (10.7%). In patients with cortical thymoma the tumor was always invasive (stages II and III according to Bergh), whereas medullary thymomas were noninvasive in 2 cases (stage I) and slightly invasive with a moderate infiltration of the capsule in the remaining case (stage II). Mixed common and mixed with cortical predominance thymomas displayed intermediate behavior. Twelve patients were affected by myasthenia gravis: 1 had medullary thymoma, 6 had mixed common thymoma, 3 had mixed thymoma with cortical predominance, and 2 had cortical thymoma. One patient with cortical thymoma had superior vena cava syndrome and 1 had erythroid hypoplasia; mixed common thymoma was associated with Cushing's syndrome in 1 patient. These data confirm previously reported observations (16) showing a higher degree of malignancy in patients with cortical thymoma.

Emission–excitation, synchronous fluorescence spectroscopy and surface-enhanced Raman scattering (SERS) combined with surface-enhanced fluorescence (SEF) were applied to aqueous solutions of a humic-like substance (HLS) extracted from earthworm faeces. All measurements were acquired in a wide range of pH (4–12) and analysed by the linear regression analysis. Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectra were also acquired to assist in the structural characterization of this HLS. The emission and excitation spectra allowed the identification of two main fluorophores in the analysed sample. Moreover, a close correlation between fluorescence intensities of each fluorophore with pH variation was observed. SERS and SEF, in agreement with the fluorescence spectroscopy, showed that the HLS at low pH values exists in an aggregated and coiled molecular structure while it is dispersed and uncoiled at alkaline conditions. The obtained spectra also evidenced that different conditions modify the functional groups exposed to the surrounding aqueous environment.

To understand if the biological activity of humic substances may be related to their molecular weight or chemical structure, two humic substances, derived from an Ah horizon of uncultivated ouch grass [Elytrigia repens (L.) Desv. ex Nevski] and an Ah horizon of forest soil, were extensively characterized by means of different spectroscopic techniques (diffuse refl ectance infrared Fourier transform [DRIFT] and 1H nuclear magnetic resonance [NMR]). The two humic substances, each separated in fractions with low (3500 Da) relative molecular mass were compared for their effects on Pinus nigra J.F. Arnold callus. Growth of callus, the soluble sugar content, free amino acid pool, and the activities of the key enzymes involved in C and N metabolism were investigated. Callus was grown for a subculture period (28 d) on basal Murashige and Skoog medium plus humic matters with or without different hormones: indole-3-acetic acid, 2,4-dichlorophenoxyacetic acid, or 6-benzylaminopurine. The results of 1H-NMR spectra and the DRIFT spectroscopy showed signifi cant differences in the chemical composition between forest and grass humic substances. A large amount of aliphatic and H-sugarlike component and an intense chemical shift of the β-CH3 region in both grass humic fractions were observed, while high contents of betaine, organic acid, and COOH groups in both forest humic fractions were detected. A different biological activity between the grass and forest humic fractions was also observed. Thus, the different activity of the two humic substances used seems related to the diverse chemical composition rather than to different molecular weights.

We evaluated the arrhythmic profile in a population of 20 Becker muscular dystrophy (BMD) patients searching for possible correlations between the severity of the arrhythmic events, the cardiac autonomic balance (assessed by heart rate variability analysis in the time domain) and the degree of left ventricular systolic impairment. A population of 14 male healthy individuals served as the control group. BMD subjects exhibited lower values of SDNN (P=0.013), SDANN index (P=0.008) and 24-h mean heart rate (P=0.002). The total number of premature ventricular beats (totPVB) and the number of PVB out of 1000 heartbeats (PVB/1000) appeared also higher in BMD subjects (P=0.05 and P=0.046, respectively). No difference was found in terms of 24-h mean QTc and 24-h longest QT among the two groups. TotPVB and PVB/1000 were inversely related to both the ejection fraction (r= -0.620, P=0.004 and r= -0.517, P=0.019) and to the shortening fraction (r= -0.568, P=0.009 and r= -0.469, P=0.037). Twenty-four-h mean QTc was also inversely related to both the ejection fraction (r= -0.520, P=0.019) and the fractional shortening (r= -0.491, P=0.028). These data suggest that in BMD there is cardiac autonomic imbalance characterized by sympathetic predominance and an increased susceptibility to ventricular arrhythmias, even in the absence of overt cardiomyopathy. Furthermore, the severity of the arrhythmic profile in BMD appears closely related to the degree of left ventricular systolic dysfunction.

Humic substances (HS) have positive effects on plant physiology, but the molecular mechanisms underlying these events are only partially under-stood. HS exert auxin-like activity, but data supporting this hypothesis are under debate. To investigate the auxin-like activity of HS, we studied their biological effect on lateral root initiation in Arabidopsis thaliana. To this aim we characterised HS by means of DRIFT and 13C CP⁄MAS NMR spectroscopy, and measured their endogenous content of IAA. We then utilised a combination of genetic and molecular approaches to unravel HS auxin activity in the initiation of lateral roots. The data obtained using specific inhibitors of auxin transport or action showed that HS induce lateral root formation mostly through their ‘auxin activity’. These findings were furthersupported by the fact that HS used in this study activated the auxin synthetic reporter DR5::GUS and enhanced transcription of the early auxin responsive gene IAA19

A detailed characterization of two humic fractions was performed: One with low relative molecular mass (LMr3,500 Da). Distinct 1H NMR spectroscopic patterns were observed for the two fractions. HMr showed an aromatic proton region, an intense and broad region (3.0–5.0 ppm) attributed to sugar-like and polyether components, and an intense doublet at 1.33 ppm (identified as protons of the β-CH3 in lactate). In contrast, LMr did not show resonances due to aromatic protons and was characterized by a broad unresolved region, assigned to sugar-like components. The 13C NMR spectra showed that the LMr humic fraction was richer in carboxylic and aliphatic C groups compared to HMr fraction. These substances were fluorescein-labeled [fluorescein isothiocyanate (FITC)], and their interaction with carrot cells in culture was monitored for 10 d, and compared to FITC–indole-3-acetic acid (IAA) to clarify their mechanisms of biological activity. After different incubation times, fluorescein staining of carrot cells and decrease of fluorescein concentration in the culture medium were evaluated. Fluorescent membrane staining was only present in IAA and the LMr humic fraction treated cell cultures. A consequential decrease of fluorescein concentration in the culture media was also observed. Pretreatment of carrot cells with unconjugated IAA or LMr humic fraction markedly reduced fluorescein staining of both FITC–IAA and FITC–LMr humic fraction. Blocking tests gave indirect evidence of possible binding of the LMr humic fraction to IAA cell membrane receptors. These results indicate that the two humic fractions behave differently. Only LMr humic fraction, like IAA, interacts with cellular membranes in carrot cell cultures.

Objective—To describe the pulsed-wave Doppler tracing of the equine lateral palmar digital artery and its modification in relation to standardized changes in posture. Animals—17 healthy Saddlebred horses. Procedure—Pulsed-wave Doppler examinations of left and right lateral palmar digital arteries of the horses were performed. The baseline examination was performed on each forelimb while horses were standing squarely with the body weight equally distributed among the 4 limbs (BED position). For each forelimb, the examination was repeated during 3 standardized modifications of the horse's posture (non–weightbearing [NWB] position, full weight-bearing [FWB] position, and a position involving hyperextension of the distal interphalangeal joint [HE position]). In each position, mean values of systolic peak velocity, first and second diastolic peak velocity, end-diastolic velocity, mean velocity, and resistive index were calculated. Data obtained in each different posture were compared statistically. Results—No significant differences in blood flow variables were detected between the left and right forelimbs. However, significant differences were detected in values of first diastolic velocity, second diastolic velocity, mean velocity, and resistive index between the NWB position and FWB position. Also, end-diastolic velocity in the NWB position was significantly different from that recorded in the HE position. Conclusions and Clinical Relevance—The pulsedwave Doppler tracing of the equine lateral palmar digital artery was modified considerably with changes in posture. This suggests that the use of a precisely standardized posture for horses is required to obtain repeatable data. (Am J Vet Res 2004;65:1211–1215)

Purpose: The use of electrophysiologic studies (EPS) for the localization of accessory atrioventricular connections in Wolff-Parkinson-White syndrome (WPW) requires accurate evaluation of the site of bypass tract insertion. Doppler myocardial imaging (DMI) is a new ultrasound technique that allows the detection of abnormal and early regional myocardial depolarization. The purpose of this study was to identify an abnormal pathway site in WPW patients. Methods: Twenty-one patients with ventricular preexcitation were studied by DMI. Two-dimensional color DMI, velocity maps, acceleration maps, and pulsed-wave applications were used. A subsequent diagnostic EPS was performed. The results of EPS were taken as the gold standard diagnostic procedure. Radiofrequency catheter ablation therapy was then performed on all patients. Results: The anomalous pathway was detected by DMI in 16 (76%) of 21 patients (9 [90%] of 10 with left pathways and 7 [64%] of 11 with right pathways), with respect to results of the EPS. Pathway detection was better with pulsed-wave DMI (76%) with its higher temporal resolution as compared with M-mode velocity map (57%) and acceleration map (47%). In most of the patients with successful radiofrequency ablation, an immediate resolution of the abnormal ventricular depolarization occurred and was detectable by DMI. Conclusions: Our findings demonstrate the feasibility of DMI to assess the early ventricular contraction associated with atrioventricular accessory pathways. Therefore, DMI appears to be a clinically useful adjunct to noninvasive evaluation of abnormal myocardial depolarization in WPW and to evaluate the results after radiofrequency ablation, even though its accuracy is considerably better for left-sided accessory pathways than for right-sided ones.

Background Circumferential radiofrequency ablation around pulmonary vein (PV) ostia has recently been described as a new anatomic approach for atrial fibrillation (AF). Methods and Results We treated 251 consecutive patients with paroxysmal (n=179) or permanent (n=72) AF. Circular PV lesions were deployed transseptally during sinus rhythm (n=124) or AF (n=127) using 3D electroanatomic guidance. Procedures lasted 148±26 minutes. Among 980 lesions surrounding individual PVs (n=956) or 2 ipsilateral veins with close openings or common ostium (n=24), 75% were defined as complete by a bipolar electrogram amplitude 30 ms across the line. The amount of low-voltage encircled area was 3594±449 mm 2 , which accounted for 23±9% of the total left atrial (LA) map surface. Major complications (cardiac tamponade) occurred in 2 patients (0.8%). No PV stenoses were detected by transesophageal echocardiography. After 10.4±4.5 months, 152 patients with paroxysmal AF (85%) and 49 with permanent AF (68%) were AF-free. Patients with and without AF recurrence did not differ in age, AF duration, prevalence of heart disease, or ejection fraction, but the LA diameter was significantly higher ( P P Conclusions Circumferential PV ablation is a safe and effective treatment for AF. Its success is likely due to both PV trigger isolation and electroanatomic remodeling of the area encompassing the PV ostia.