The Cooperative Italian FLIN Study Group: prevalence and clinico-pathological features of colorectal laterally spreading tumors.

BACKGROUND AND STUDY AIMS: Laterally spreading tumors (LSTs) are increasingly recognized as important precursors of colorectal carcinoma. The clinical behavior of these large nonpolypoid lesions is still uncertain. The aim of the present study was to assess prevalence and clinico-pathological features of LSTs in a large Italian cohort of patients. METHODS: The study was a subgroup analysis of a large database of patients undergoing total colonoscopy. The database originated from a multicenter cross-sectional observational study involving 80 centers throughout Italy. RESULTS: Data from 27,400 total colonoscopies were analyzed. Precancerous lesions were detected in 5609 patients. Of these, LSTs were identified in 254 patients (4.5%; 95% confidence interval [CI] 3.5-6.2). Granular-type LSTs (G-LSTs) accounted for 83% of the cases (211/254). LSTs were predominant in the proximal colon (154, 60.6%). A total 231 lesions were endoscopically removed, with histology being available for 242. Neoplasia was confirmed in 225 lesions (93.4%) (143 low grade adenoma, 76 high grade adenoma, and six submucosal cancer). The six cases of submucosally invasive carcinoma were diagnosed in five G-LST and one nongranular LST (NG-LST). The risk of containing advanced histology was not increased in G-LST compared with NG-LST (odds ratio [OR] 1.55, 95%CI 0.73-3.27); it was significantly higher in lesions with large nodules (OR 3.09, 95%CI 1.05-9.04; P = 0.041) or depressed surface (OR 4.27, 95%CI 1.24-14.61; P = 0.021). CONCLUSIONS: LSTs represent approximately 5% of all precancerous colorectal lesions in the Italian population and are prevalent in the proximal colon. These lesions are no more likely to harbor advanced histology than similar-sized polypoid lesions. Large nodularity or depressed surface are risk factors for advanced histology.

How to predict a high rate of inappropriateness for upper endoscopy in an endoscopic centre?

BACKGROUND: Inappropriateness of upper endoscopy (EGD) indication causes decreased diagnostic yield. Our aim of was to identify predictors of appropriateness rate for EGD among endoscopic centres. METHODS: A post-hoc analysis of two multicentre cross-sectional studies, including 6270 and 8252 patients consecutively referred to EGD in 44 (group A) and 55 (group B) endoscopic Italian centres in 2003 and 2007, respectively, was performed. A multiple forward stepwise regression was applied to group A, and independently validated in group B. A <70% threshold was adopted to define inadequate appropriateness rate clustered by centre. RESULTS: discrete variability of clustered appropriateness rates among the 44 group A centres was observed (median: 77%; range: 41-97%), and a <70% appropriateness rate was detected in 11 (25%). Independent predictors of centre appropriateness rate were: percentage of patients referred by general practitioners (GP), rate of urgent examinations, prevalence of relevant diseases, and academic status. For group B, sensitivity, specificity and area under receiver operating characteristic curve of the model in detecting centres with a <70% appropriateness rate were 54%, 93% and 0.72, respectively. CONCLUSIONS: A simple predictive rule, based on rate of patients referred by GPs, rate of urgent examinations, prevalence of relevant diseases and academic status, identified a small subset of centres characterised by a high rate of inappropriateness. These centres may be presumed to obtain the largest benefit from targeted educational programs.

Prevalence of nonpolypoid colorectal neoplasia: an Italian multicenter observational study.

BACKGROUND AND STUDY AIM: The aim of this study was to assess the prevalence of nonpolypoid lesions (NPLs) in Italy and their risk of containing neoplasia or advanced histology. PATIENTS AND METHODS: This was a multicenter cross-sectional observational study on consecutive patients undergoing total colonoscopy over a 3-month period in 80 Italian centers. RESULTS: In all, 27,400 total colonoscopies were analyzed. Cancer was diagnosed in 801 patients (2.9 %). A total of 6553 precancerous lesions were detected in 5609 patients. Of these, 4154 patients (74.1 %) had polypoid lesions and 1455 patients (25.9 %) had NPLs. Therefore, the prevalence of NPLs was 5.3 % (95 %CI 5.0 - 5.6). NPLs larger than 10 mm were detected in 254 patients (17.5 %). NPLs were more predominant in the proximal colon (OR 2.92, 95 %CI 2.56 - 3.43; P < 0.0001 vs. polypoid lesions). Neoplastic tissue was diagnosed in 79.0 % and advanced histology (high-grade intraepithelial neoplasia or more) in 20.9 % of resected lesions. The risk of advanced histology was similar for polypoid and nonpolypoid lesions when adjusted for size. Depressed lesions had the highest risk of advanced histology (OR 10.56, 95 %CI 6.02 - 18.55; P < 0.0000 vs. flat-elevated). Age was an independent predictor of both neoplasia and advanced histology ( P = 0.0001). CONCLUSIONS: NPLs are relatively common in the Italian population, with a prevalence similar to that in other Western series. NPLs are not more aggressive than polypoid lesions, except for those with depressed morphology.

Amyloid deposits inside myocardial fibers in transthyretin-Met30 familial amyloidotic polyneuropathy. A histological and biochemical study.

A case of severe cardiac involvement is reported in a patient affected with familial amyloidotic polyneuropathy due to the Portuguese type I variant (Val-->Met30) of the transthyretin (prealbumin) molecule. Echocardiographic and hemodynamic studies suggested the presence of a progressive infiltrative cardiomyopathy that was later confirmed by endomyocardial biopsy. Amyloid deposits were found in both intra- and extra-myofiber location and thought to be related to primary involvement of the heart. Norepinephrine content of myocardial bioptic specimens was about threefold lower than normal, indicating that autonomic denervation may contribute to the maintenance and progression of cardiomyopathy. A sample obtained from the sural nerve showed a loss of myelinated fibers along with accumulation of amyloid masses in the endoneurial space. This histopathologic pattern correlated with a sharp decrease in the activity of the enzyme subserving electrochemical conduction through the axonal membrane, Na+, K(+)-ATPase.

Molecular aspects of cloricromene (AD6) distribution in human platelets and its pharmacological effects.

Cloricromene (AD6) is an investigational drug which inhibits platelet aggregation and release reaction. We studied the relationship between its action and its distribution and metabolism in platelets. Incubation of anticoagulated whole blood or platelet-rich plasma (PRP) without exogenous aggregating agents resulted in a progressive decrease of platelet count with a concomitant increase of beta-thromboglobulin (BTG) release. AD6 (20-50 mumols/l), but not acetylsalicylic acid (ASA), incubated with whole blood or PRP, prevented the fall in platelet count and the release of BTG for at least 150 min. Moreover, incubation of PRP with AD6 (50 mumols/l) and subsequent stimulation by ADP at threshold concentrations resulted in a significant reduction (about 30%) in aggregation for at least 90 min. AD6 (20 mumols/l) added to PRP was rapidly metabolized by hydrolysis of an ester bond to AD6 acid, a stable catabolite pharmacologically inactive in platelets. Significant amounts of AD6 acid (up to 13.26 +/- 2.80 pmol/10(6) platelets) were associated with the platelets after incubation either at 37 degrees C or 4 degrees C. The amount of AD6 acid in the platelet pellet was proportional to AD6 concentration (2 to 100 mumols/l). PRP incubation with AD6 acid (20 mumols/l) resulted in very low levels (less than 1 pmol/10(6) platelets) of the same compound in the platelet pellet after 1, 5 or 30 min. These data suggest that AD6 is taken up as an ester and converted to its acid catabolite with a consequent long-lasting inhibition of platelet function.

Platelet activating factor induces dopamine release in PC-12 cell line.

The ability of platelet activating factor (PAF) to stimulate dopamine release and modify calcium homeostasis in PC-12 cell line was studied. PAF-induced dopamine release is related to its molecular form, with only the R-form steric configuration [(R)PAF], but not its S-form or its 2-lyso derivative, effective at being active. In addition, PAF acts at very low concentrations in a dose-dependent manner (0.1-30 nM). Preincubation with PAF receptor antagonists (CV-3988 and BN52021) as well as the specific desensitization of PC-12 cells to (R)PAF abolish the (R)PAF-induced dopamine release. Several lines of evidence suggest that dopamine release is dependent on a (R)PAF-induced calcium influx and efflux modulation. Dopamine release by PC-12 cells challenged with (R)PAF is associated with a rapid 45Ca influx and efflux and a rise in cytoplasmic calcium concentrations ([Ca2+]i) evaluated by using the calcium indicators fura-2 and quin2. At 30 nM (R)PAF, the absence of extracellular calcium inhibits the dopamine release but not the rise of [Ca2+]i from the internal stores, suggesting the importance of calcium influx in (R)PAF-induced dopamine release. PAF, which has been reported to be synthesized by stimulated neuronal cells (J. Biol. Chem. 261: 16502-16508, 1986) may thus have a physiological modulatory role on cells with neurosecretory properties.

General toxicity and peripheral nerve alterations induced by chronic vincristine treatment in the rabbit.

The effects of five 0.3 mg/kg intravenous administrations of vincristine (VCR) at weekly intervals were studied in the rabbit. Body weight gain was impaired starting from the first injection, while gross signs of motor paralysis and hair loss initiated from the third week. At the end of the observation period blood analysis revealed normocytic normochromic anemia, elevated serum creatine kinase, and low serum alkaline phosphatase, whereas all the tested parameters related to liver and kidney functions where within normal limits. The decreased number of red blood cells was the consequence of a complete, although reversible, blockade of staminal hematopoietic activity. Two important indexes of peripheral nerve function were clearly altered at the end of the treatment: (i) the sciatic nerve conduction velocity in vitro was 27% reduced and (ii) the latency between sciatic nerve stimulation and extensor digitorum longus (EDL) twitch in vivo was 34% prolonged. The usefulness of the rabbit as an animal model to study side-effects of VCR treatment is discussed.

Ventricular myosin pattern of spontaneously hypertensive turkeys is unaffected by labetalol treatment.

In most animal species, left ventricular hypertrophy due to pressure overload is associated with an advantageous increase of the "slow" V3 isomyosin. In contrast, in spontaneously hypertensive turkeys, the development of left ventricular hypertrophy is associated with the synthesis of a "fast" V1-like isomyosin, with high incidence of cardiac failure. This could be related to the high catecholamine levels found in these animals. This is why we studied the ventricular myosin pattern after lowering of blood pressure and regression of cardiac hypertrophy obtained by means of labetalol, and alpha- and beta-blocking drug which inhibits the effects of catecholamines. From the 2nd to the 32nd week of age, 22 turkeys were treated with increasing doses of p.o. labetalol (from 20 to 35 mg/kg body weight daily) and 16 other turkeys were given daily p.o. placebo. Blood pressure and heart rate were periodically measured by an indirect method. After sacrifice, the degree of cardiac hypertrophy was evaluated by the biventricular weight to body weight ratio, ventricular myosin was purified, Ca++-activated ATPase activity assessed, and ventricular myosin pattern was determined by two-dimensional gel electrophoresis of myosin heavy chains. Plasma and cardiac catecholamines were measured by high performance liquid chromatography. Throughout the study period, blood pressure and heart rate were significantly reduced in the labetalol-treated animals as compared to the untreated ones. At the end of the study period, the ventricular mass was significantly lower in the labetalol group. Nevertheless, no differences were observed in ventricular myosin pattern and Ca++-activated ATPase activity levels between the two groups. In the labetalol group, an increase in plasma catecholamines and only a slight, but not significant, increase in cardiac catecholamines was found. These data indicate that in spontaneously hypertensive turkeys, the synthesis of the "fast" V1-like isomyosin is not influenced by known pathophysiological stimuli like blood pressure, cardiac hypertrophy and catecholamines.

Effects of long-term diabetes and treatment with gangliosides on cardiac sympathetic innervation: a biochemical and functional study in mice.

The effect of long-term diabetes on cardiac sympathetic innervation was investigated in genetically obese diabetic mice (db/db). Previous studies have shown the presence of a peripheral neuropathy starting a few months after birth, and we recently reported a significant reduction of myocardial norepinephrine (NE) levels in the hearts of diabetic mice at the age of 6 months. In the present study, histofluorescence analysis of comparable sections of cardiac tissue of both control and diabetic animals confirmed the picture of a sympathetic denervated heart in this experimental model. Furthermore, functional studies in isolated atria revealed a difference between the two groups of animals: in fact heart rate increases induced by transmural stimulation were significantly lower in diabetic mice. Since a bovine brain ganglioside mixture (Cronassial) has been extensively studied for its effect on peripheral diabetic neuropathy, a group of diabetic mice was treated throughout the sixth month with this drug (10 mg/kg/day i.p.). The ganglioside treated animals showed a marked recovery of atrial function and cardiac NE concentration. The above results clearly indicate sympathetic neural damage in db/db animals, likely related to an autonomic diabetic neuropathy and a possible protection by ganglioside of adrenergic nerves from this alteration.

Alterations of the vegetative nervous system, experimental diabetes and pharmacological use of gangliosides.

We studied in diabetic animals several variables related to the vegetative innervation of the heart and the urinary bladder. Cardiac content of norepinephrine was lower in the heart of the diabetic mice (db/db) as compared to the heart of their heterozygote littermates (db/m). Bladder responses were clearly altered in alloxan treated rats as compared to normal rats, as shown by an increased vesical weight, an increased threshold for micturition reflex and a reduced rate of rhythmic contraction. Ganglioside administration was able to prevent partly or completely these alterations observed in the diabetic animals.

GM1 ganglioside counteracts selective neurotoxin-induced lesion of developing serotonin neurons in rat spinal cord.

The effect of exogenous monosialoganglioside GM1 on neurotoxin-induced lesioning of bulbo-spinal serotonergic neurons of newborn rats was studied by means of biochemical and immunocytochemical techniques. 5,7-dihydroxytryptamine (5,7-HT, a selective serotonin neurotoxin) treatment of newborn rats caused a pronounced reduction of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels in the thoracic and lumbar spinal cord, while an increase of 5-HT and 5-HIAA was found in the pons medulla. These biochemical alterations were regionally correlated with similar changes in 5-HT nerve terminal density analyzed by image analysis. GM1 administration (30 mg/kg for 4 consecutive days) antagonized the reduction of 5-HT and 5-HIAA levels induced by 5,7-HT treatment in the lumbar spinal cord of 2-month-old rats, as well as the decrease of 5-HT nerve terminal density in both thoracic and lumbar spinal cord of 1- and 2-month-old rats. A minor counteracting effect of GM1 was found in the pons medulla where the neurotoxin induced an increase of 5-HT and 5-HIAA levels. These data support the hypothesis that GM1 may have a preventing action on retrograde degenerative processes following chemical lesion and/or a growth-stimulating effect on injured 5-HT neurons.

Inhibition by AD6 (8-monochloro-3-beta-diethylaminoethyl-4-methyl-7-ethoxycarbonyl methoxy coumarin) of platelet aggregation in dog stenosed coronary artery.

The action of AD6 as an anti-thrombotic agent was studied in a model of coronary artery thrombosis and on platelet aggregation in the dog. AD6 (10-100 microM) in vitro inhibited aggregation induced by ADP, epinephrine, collagen and PAF (platelet aggregating factor) used at their threshold concentration for maximal aggregation. Arterial thrombosis was induced in a coronary vessel by critically reducing (about 70%) the vessel lumen. Thrombus formation was estimated by measuring coronary flow in the stenosed vessel. Using this procedure on the left descending coronary artery (LAD), we obtained reproducible blood flow changes in 18 dogs. AD6 was given i.v. at three different doses. At 0.25 mg/kg two out of four dogs showed decreased thrombus formation at the stenosis site. Seven out of eleven dogs treated with 0.5 mg/kg and two out of three treated with 1.5 mg/kg showed decreased thrombus formation. Major decreases in coronary resistance, evaluated by measuring blood flow in the unstenosed left circumflex artery (LCX), were evident only after the highest dose. We conclude that AD6 has an inhibitory action on dog platelet aggregation and reduces thrombus formation in a stenosed coronary vessel.

Age related changes in the antilipolytic effects of nicotinic acid in rat adipose tissue.

The effect of nicotinic acid on lipolysis was tested in vitro in adipose tissue from three groups of rats, selected according to age: 6-7 weeks, 10-12 weeks and 16-20 weeks old. Although the changes were not statistically significant, the basal release of free fatty acid (FFA) was increased and glycerol was decreased by nicotinic acid (0.01-1 mM); the drug caused a statistically significant increase in basal FFA: glycerol ratio in a concentration-dependent manner. This ratio also increased with age in the absence of drug. (-)-Noradrenaline (10 microM) and theophylline (3 mM) each stimulated lipolysis. When glycerol release was calculated as a percentage increase, the effects of these drugs became more marked with age. By contrast, the highest absolute rate of induced release occurred in adipose tissue from the youngest rats. The lipolytic effect of 10 microM (-)-noradrenaline was generally unaffected by nicotinic acid except in adipose tissue from the oldest rats when the glycerol release was reduced by 1 mM nicotinic acid, although it did not alter FFA:glycerol ratio. The stimulation of glycerol release induced by 3 mM theophylline was not affected by the presence of nicotinic acid in the youngest rats, but the drug elicited a concentration-dependent antilipolytic effect in adipose tissue from 10-12 weeks old rats, which was even more pronounced in the oldest animals. Lower theophylline concentrations (0.6-1 mM) were also sensitive to nicotinic acid inhibition in the 6-7 weeks old rats. In the presence of theophylline, nicotinic acid had no effect on FFA:glycerol ratio. These data show a direct influence of age on the antilipolytic action of nicotinic acid.

Positive inotropic effect of a stable analogue of PGI2 and of PGI2 on isolated guinea pig atria. Mechanism of action.

Fluoroprostacyclin (10,10-difluoro-13,14-dehydroprostacyclin) a stable analogue of PGI2, induced an increase of contractile tension and a positive chronotropic effect on spontaneously beating guinea-pig atria. The increase in contractile tension was proportional to the dose (10(-8) to 2.5 X 10(-7) M) and never exceeded 40% of absolute initial controls. The chronotropic positive effect was low (12 +/- 4%) and not dose-dependent. The positive inotropic effect was also evident on electrically driven atria and was greater at the slower rates of stimulation. Atria from guinea pigs pretreated with reserpine were still sensitive to fluoroprostacyclin, although to a lower degree. The use of appropriate agonists and antagonists excluded the possibility that beta and alpha receptors are involved in the positive inotropic effect of fluoroprostacyclin. PGI2 showed the same behavior as fluoro-PGI2. Prostacyclins were able to reverse the decrease of contractility induced by verapamil, nifedipine, tetrodotoxin and xylocaine. But the reversal by PGI2 was no longer evident when the atrial contractility was completely abolished by the presence of these drugs in high concentrations. The inotropic effect of prostacyclins was more evident when Ca2+ was reduced in the medium. These results demonstrate that the cardiostimulant effect of prostacyclins is not simply adrenergic in origin. A direct effect on ion movements, mainly dependent on Ca2+ transmembranes fluxes, may be largely responsible for their positive inotropic effect.

Age-related changes in rat adipose tissue in response to fasting: protein, lactate and pyruvate levels.

1. The evolution with age of the metabolic response of adipose tissue to fasting has been investigated in two groups of rats, at different ages, fed and fasted. 2. The protein tissue content increases in response to fasting in young rats but not in adult-old ones. This indicates a lower lipomobilizing response to starvation with increasing age. 3. In contrast to young rats, the adult rat lactate is not increased by fasting while pyruvate is increased. 4. As a result of lactate and pyruvate variations, NAD/NADH is also changed: after fasting it decreases in young rats, while it increases in older rats. 5. Absolute NAD level is decreased by fasting both in young and older rats. 6. These data provide experimental support for the decreased sensitivity of fat pads from older animals to stimuli affecting lipolysis.

Effect of cyclonicate, a new hypolipemic drug, on lipolysis in vitro.

A new hypolipemic drug, cyclonicate (3,3,5-trimethyl-cyclohexyl nicotinate), was studied and its effects were compared with those of nicotinic acid. Experiments were carried out in vitro on rat adipose tissue on spontaneous lipolysis, and on lipolysis stimulated by noradrenaline, theophylline, dibutyryl cyclic AMP. Cyclonicate, like nicotinic acid, reduced the lipolytic stimulation of theophylline. Its effect was dose-dependent but 10 times lower (IC50 = 1 mM) than that of nicotinic acid. The inhibitory activity of both compounds was higher on theophylline-induced lipolysis than on noradrenaline-stimulated lipolysis. Neither one had any effect on dibutyryl cyclic AMP. In the absence of stimulating drugs, cyclonicate increased the FFA/glycerol ratio, more than nicotinic acid. Moreover, cyclonicate inhibited theophylline-induced FFA release much less than glycerol release, while under the same conditions, nicotinic acid inhibited both FFA and glycerol release. Thus cyclonicate would influence not only triglyceride hydrolysis, but also FFA utilization by adipose tissue.