Giampietro Feltrin

Adrenal vein sampling for primary aldosteronism: the assessment of selectivity and lateralization of aldosterone excess baseline and after adrenocorticotropic hormone (ACTH) stimulation.

Background Adrenal vein sampling is crucial for identifying the primary aldosteronism subtypes, but the cutoff values for ascertaining selectivity of catheterization and lateralization of aldosterone secretion remain controversial. Objectives To investigate the safety of adrenal vein sampling, the cutoff values for the selectivity and lateralization indexes, and the effect of adrenocorticotropic hormone stimulation on selectivity index and lateralization index performance. Design We assessed the proportion of selective adrenal vein sampling at different selectivity index cutoff values in 151 consecutive patients with primary aldosteronism undergoing bilaterally simultaneous adrenal vein sampling. Aldosterone-producing adenoma was diagnosed on the basis of the evidence of primary aldosteronism and lateralized aldosterone secretion, adenoma at pathological examination, and normokalemia, and correction of primary aldosteronism and cure or improvement of hypertension at follow-up. In 44 patients with bilaterally selective adrenal vein sampling and unequivocal diagnosis of aldosterone-producing adenoma on the basis of all these criteria, we examined the cutoff values of the lateralization index for assessing the lateralization of aldosterone excess and the effect of adrenocorticotropic hormone stimulation on selectivity index and lateralization index. Results Adrenal vein rupture occurred in one case (0.7%). Bilaterally selective adrenal vein sampling decreased steadily (from 79.9 to 40.2%) with increase in the selectivity index cutoffs from 1.1 to 5.0. Likewise, the proportion of correctly identified aldosterone-producing adenomas decreased (from 95.5 to 43.2%) with increase in lateralization index cutoffs from 1.125 to 5.0. Adrenocorticotropic hormone improved the assessment of selectivity but exerted a confounding effect on lateralization index. Conclusion Adrenal vein sampling is safe; increasing the selectivity index cutoffs lowers the number of usable adrenal vein samplings; higher lateralization index cutoff values lead to missing a proportion of aldosterone-producing adenomas. The improved selectivity rate provided by adrenocorticotropic hormone stimulation should be weighed against the loss of correct lateralization.

Social grasping: From mirroring to mentalizing

Because the way we grasp an object varies depending on the intention with which the object is grasped, monitoring the properties of prehensile movements may provide access to a persons intention. Here we investigate the role of visual kinematics in the implicit coding of intention, by using functional brain imaging while participants observed grasping movements performed with social versus individual intents. The results show that activation within the mirror system is stronger during the observation of socially intended movements relative to individual movements. Moreover, areas that form the mentalizing system are more active during social grasping movements. These findings demonstrate that, in the absence of context information, social information conveyed by action kinematics modulates intention processing, leading to a transition from mirroring to mentalizing.

Radiological evidence of subclinical dysphagia in motor neuron disease.

Abstract Dysphagia in motor neuron disease (MND) may lead to dangerous complications such as cachexia and aspiration pneumonia. Functional evaluation of the oropharyngeal tract is crucial for identifying specific swallowing dysfunctions and planning appropriate rehabilitation. As part of a multidisciplinary study on the treatment of dysphagia in patients with neuromuscular diseases, 23 MND patients with different degrees of dysphagia underwent videoflouroscopy, videopharyngolaryngoscopy and pharyngo-oesophageal manometry. The results of the three instrumental investigations were analysed in order (1) to define the pattern of swallowing in MND patients complaining of dysphagia; (2) to evaluate whether subclinical abnormalities may be detected; and (3) to assess the role of videofluoroscopy, videopharyngolaryngoscopy and manometry in the evaluation of MND patients with deglutition problems. Correlations between the instrumental findings and clinical features (age of the patients, duration and severity of the disease, presence and degree of dysphagia) were also assessed. The results of our study showed that: (1) The oral phase of deglutition was compromised most often, followed by the pharyngeal phase. (2) In all patients without clinical evidence of dysphagia, subclinical videofluoroscopic alterations were present in a pattern similar to that found in the dysphagic group. (3) Videofluoroscopy was the most sensitive technique in identifying oropharyngeal alterations of swallowing. Impairment of the oral phase, abnormal pharyngo-oesophageal motility and incomplete relaxation of the upper oesophageal sphincter were the changes most sensitive in detecting dysphagia. Videofluoroscopy was also capable of detecting preclinical abnormalities in non-dysphagic patients who later developed dysphagia. Practical guidelines for the use of instrumental investigations in the assessment and management of dysphagia in MND patients are proposed.

Diaphragmatic sulci and portal fissures

Diaphragmatic sulci in the superior surface of the liver were found in 40% of cases at autopsy. All sulci were located in the right lobe and in 47% they were multiple. In order to evaluate possible predisposing factors for these accessory sulci, their topography and characteristics were observed in unfixed livers; moreover, intravenous injections of radio‐opaque resins were performed in the portal and hepatic veins (HVs). After formalin fixation, the livers underwent CT and MR scans and a three‐dimensional (3D) elaboration of the images was performed. Radiological examination revealed a correspondence between the topography of the sulci and the course of the right and middle HVs and their main tributaries in 67%. The corrosion casts showed the location of the sulci at the level of the boundaries between the ramifications of the terminal branches of the portal triad, where the HVs are located, in 73%. These findings suggest that, rather than the action of ‘special’ or hypertrophied muscle bundles, the pressure exerted by the diaphragm as a whole may be responsible for the production of sulci at the level of weak zones, represented by the portal fissures, where the watershed superficial hepatic parenchyma, owing to the absence of all but the smallest vascular branches, exhibits a lower resistance to external pressure.

Morphometric Analysis of the Canal System of Cortical Bone: An Experimental Study in the Rabbit Femur Carried Out with Standard Histology and Micro‐CT

The osteonal pattern of cortical bone is gradually built around the intracortical vessels by the progression of the cutting cones (secondary remodelling); therefore, the central canal size can be used as index of the remodelling activity. An experimental model in the rabbit femur was used to investigate, through central canal morphometry and frequency distribution analysis, the remodelling activity, comparing the middle of the diaphysis (mid‐shaft) with the extremity (distal‐shaft) and at the same level sectors and layers of the cortex in transversal sections. The study documented a higher density of canals in the mid‐shaft than in the distal‐shaft and a higher remodelling in the distal‐shaft. There were no significant differences between dorsal, ventral, medial and lateral sectors at both mid‐shaft and distal‐shaft levels, while the number of canals was higher in the sub‐periosteal layers than in the sub‐endosteal. A lower threshold of 40 μm2 was observed in the central canal area. Sealed osteons in the midshaft were 22.43% of the total number of osteons of the central canal area between 40 and 200 μm2 and 0.44% of those of the distal‐shaft. Micro‐CT allowed a 3D reconstruction of the vascular canal system, which confirmed the branched network pattern rather than the trim architecture of the traditional representation. Some aspects like the lower threshold of the central canal size and the sealed osteons documented the plasticity of the system and its capacity for adaptation to changes in the haemodynamic conditions.

Methylprednisolone-Induced Hypertension in the Rat: Evidence Against the Role of Plasma Volume Changes, Vasopressin and Renal Prostaglandin E2

The purpose of the study was to clarify the mechanism(s) of glucocorticoid-induced hypertension. Hypertension was induced in rats by single i.m. injection of methylprednisolone (MP) 20 mg/kg. In normal Wistar rats, systolic blood pressure (SBP) increased by 30 mmHg from days 2 to 10 after MP. Urinary sodium excretion increased transiently and sodium balance was negative. Plasma volume (PV; ml/100 g body weight) increased on day 5, but was unchanged on day 2 after MP, at a time when SBP had already increased. In rats with chronic renal failure (CRF) and low sodium intake, SBP increased more than in control rats (48 versus 22 mmHg on day 10). Hypertension was not accompanied by a significant drop in urinary excretion of prostaglandin E2 (PGE2; measured by radio-immunoassay). In normal MP-injected rats, PGE2 excretion decreased slightly and then increased; in CRF rats, basal PGE2 excretion was too low to evaluate the effect of MP. In homozygous Brattleboro rats lacking antidiuretic hormone (ADH), MP increased SBP by 28 mmHg (day 10). Similar changes were obtained in heterozygous Brattleboro rats. The changes in PV were identical to those found in Wistar rats. We conclude that increase in PV, change in PGE2 and vasopressin do not play a key role in MP hypertension. Direct effect of glucocorticoid on vascular receptors is likely to be involved in this model.

Positive correlation of CTG expansion and pharyngoesophageal alterations in myotonic dystrophy patients.

Alteration of the pharyngoesophageal musculature is a common finding in patients with myotonic dystrophy (MD), regardless of the presence of dysphagia. The aim of the present study was to determine whether a specific pattern of swallowing abnormalities could be identified in MD patients, and the possible correlation with the size of CTG repeats. Fifteen MD patients, 8 of whom were asymptomatic for dysphagia, underwent a videofluoroscopic study of swallowing. Alterations of the pharyngoesophageal phase of swallowing were detected in 12 of 15 patients, 6 without clinical evidence of dysphagia. Incomplete relaxation of the upper esophageal sphincter (UES) and esophageal hypotonia were the most common alterations. We found a significant correlation between the number of radiological alterations and the size of CTG repeats. A typical radiological pattern of swallowing has also been identified. The role of videofluoroscopy in evaluation of MD patients is briefly discussed.

Porous alginate/poly(ε-caprolactone) scaffolds: preparation, characterization and in vitro biological activity

In bone tissue engineering, scaffolds with controlled porosity are required to allow cell ingrowth, nutrient diffusion and sufficient formation of vascular networks. The physical properties of synthetic scaffolds are known to be dependent on the biomaterial type and its processing technique. In this study, we demonstrate that the separation phase technique is a useful method to process poly(ε-caprolactone) (PCL) into a desired shape and size. Moreover, using poly(ethylene glycol), sucrose, fructose and Ca2+ alginate as porogen agents, we obtained PCL scaffolds with three-dimensional porous structures characterized by different pore size and geometry. Scanning electron microscopy and porosity analysis indicated that PCL scaffolds prepared with Ca2+ alginate threads resemble the porosity and the homogeneous pore size distribution of native bone. In parallel, MicroCT analysis confirmed the presence of interconnected void spaces suitable to guarantee a biological environment for cellular growth, as demonstrated by a biocompatibility test with MC3T3-E1 murine preosteoblastic cells. In particular, scaffolds prepared with Ca2+ alginate threads increased adhesion and proliferation of MC3T3-E1 cells under basal culture conditions, and upon stimulation with a specific differentiation culture medium they enhanced the early and later differentiated cell functions, including alkaline phosphatase activity and mineralized extracellular matrix production. These results suggest that PCL scaffolds, obtained by separation phase technique and prepared with alginate threads, could be considered as candidates for bone tissue engineering applications, possessing the required physical and biological properties.

Transcatheter arterial embolisation versus no treatment in cirrhotic patients with hepatocellular carcinoma: a retrospective comparative study

To evaluate the effectiveness of transcatheter arterial embolisation (TAE) as a treatment of hepatocellular carcinoma (HCC) complicating cirrhosis, the survival of 27 untreated patients and 57 TAE-treated patients was compared. Clinical features, laboratory findings and tumour stage were comparable in the two groups of patients. TAE was undertaken with epirubicin, iodised oil and gelatine esponge. Cumulative survival rates at 6, 12, 24 and 36 months were 0.59, 0.47, 0.17 and 0.08 in the untreated group, and 0.87, 0.75, 0.40 and 0.19 in the TAE-treated group (P = 0.01). Patients with Childs grade B cirrhosis and patients with tumour smaller than 25% of the liver volume responded better to TAE. Twenty-four untreated patients and 25 TAE-treated patients died during the follow-up. The complication rate and mortality rate of TAE were 28% and 1.7% respectively. TAE prolongs the survival of patients with HCC complicating cirrhosis; prognosis depends on tumour stage and the degree of hepatic function impairment.

Transhepatic Portal Catheterization with Pancreatic Venous Sampling Versus Angiography in the Localization of Pancreatic Functioning Tumors

Selective arteriography is a well-defined procedure in localizing functioning tumors of the pancreas; however, its diagnostic accuracy is rarely greater than 80% (Clouse et al. 1977; Fugjii et al. 1964; Korobkin et al. 1971; Madsen and Hansen 1970; Robins et al. 1973; Stefanini et al. 1974). To improve diagnostic accuracy in this field, transhepatic portal catheterization (TPC) has been introduced over the last few years (Gothlin et al. 1974; Ingemansson et al. 1975; Lunderquist and Tylen 1975; Reichardt and Ingemansson 1980) as a method of obtaining blood samples from pancreatic and peripancreatic veins for radioimmunologic assay of pancreatic hormone concentration.