Biomedical subjects
Publications and source records attributed to E Berardi.
In the last 20 years there have been many breakthroughs in the treatment of gastrointestinal tumours. In this review we have considered the three most important subgroups of gastrointestinal tumours (colorectal, gastric and pancreatic cancer), focusing on the state-of-the-art treatments.
In Hansenula polymorpha, the expression of the nitrate assimilation metabolism is subjected to re-pression-derepression mechanisms triggered by reduced nitrogen compounds such as ammonium. To further our knowledge on the genetics of these regulatory mechanisms, a screening strategy for the isolation of mutants exhibiting nitrate reductase activities in the presence of reduced nitrogen compounds was set up. This strategy makes use of a nitrate+ methylamine mutant to isolate suppressors of its characteristic phenotype--the inability to grow on a nitrate plus methylamine medium. A total of 21 regulatory mutants were isolated with this strategy and grouped into five complementation classes. One of these mutants harbours the recessive mutation nmr1-1, which determines the derepression of the nitrate assimilation metabolism in media containing nitrate plus a repressing nitrogen source (ammonium, methylamine, glutamate, urea or aspartate). Therefore, nitrate reductase activities are detected in the presence of reduced nitrogen sources, as long as nitrate is also in the medium. Our data indicate that the processes of repression-derepression and induction are controlled by elements which are distinct. Furthermore, they indicate that Nmrlp is involved in repressing circuits which control not only the nitrate-utilisation pathway, but also other pathways which are necessary for the utilisation of nitrogen sources alternative to ammonium. Of considerable interest is the fact that our nmr1-1 mutant is derepressed in glutamate but not in glutamine. Since the phenotype of this mutant seems to exclude a glutamine synthetase defect, we suggest that glutamate (or a derivative of this compound) might be involved in signalling nitrogen metabolite repression in H. polymorpha. Thus, in H. polymorpha, a glutamine-dependent circuit may co-exist with a glutamine-independent circuit.
BACKGROUND/AIMS: This double-blind study was designed to evaluate the haemodynamic effect of two drugs, propranolol and octreotide, and their combination in patients with cirrhosis. METHODS: Fifteen patients with cirrhosis were randomly assigned to two groups receiving either octreotide subcutaneously at 100 microg ('octreotide' group, n = 9) or propranolol orally at 40 mg followed by a subcutaneous dose of octreotide (100 microg) after 1 h ('propranolol + octreotide' group, n = 6); then, after 30 min, a standard meal was administered to both groups. The hepatic vein pressure gradient by hepatic vein catheterization, portal and superior mesenteric artery blood flow velocity, superior mesenteric artery pulsatility index by the echo-Doppler duplex system were recorded at baseline, 1 h after propranolol in the 'propranolol + octreotide' group, and in both groups 30 min after octreotide and 30 min after meal. RESULTS: At fast, propranolol was more active in decreasing portal pressure (from 16 +/- 2.2 to 12.7 +/- 3.8 mmHg, -20%, P < 0.05) as compared to octreotide (from 18.6 +/- 4.8 to 16.6 +/- 4.3 mmHg, -11%, P < 0.05). Conversely, octreotide was more active on the mean blood flow velocity of superior mesenteric artery (from 22.8 +/- 5 to 19 +/- 4.5 cm/ s, -17%; P< 0.05). Octreotide administration in patients receiving beta-blockers showed, also, a trend to increase the mesenteric vascular resistances (pulsatility index from 3.14 +/- 0.69 to 3.68 +/- 1.29, +17%, not significant (NS)) which had not been affected by previous treatment with propranolol. After the meal, a reduction of the expected hyperaemic response occurred in both groups. CONCLUSIONS: The combined acute haemodynamic effect of this association suggests the possible combination of these two drugs in critical situations, such as variceal bleeding in patients receiving beta-blockers. The simultaneous use of echo-Doppler and hepatic vein catheterization permitted us a more complete analysis of the acute haemodynamic events.
In this study, aimed at identifying genetic factors acting positively upon the MOX gene, we report the isolation and characterisation of several methanol utilisation-defective (Mut-) mutants of Hansenula polymorpha. These fall into 12 complementation groups, eight of which show significant reductions in alcohol (methanol) oxidase activity in methanol. Three of these groups, identifying the MUT3, MUT5 and MUT10 loci, exhibit extremely low levels of MOX promoter activity, not only in methanol medium, but also during growth in glycerol or methylamine. We suggest that these loci play a significant role in the derepression of the MOX gene expression. One of these genes (MUT10) also seems to be involved in the utilisation of carbon sources other than methanol, and it is apparent that the same gene plays some role in the biogenesis or in the enlargement of the peroxisome. Three other genes (MUT7, MUT8 and MUT9) appear to be involved in peroxisome biogenesis, whereas most other mutants harbour lesions that leave the peroxisome biogenesis and proliferation unaffected.
Mutant LGM-128 of Hansenula polymorpha harbors the recessive mutation glr2-1 which confers a complex pleiotropic phenotype, the major feature of which is the metabolically unnecessary induction of methanol utilization metabolism (C1 metabolism) during growth on glucose, whether or not methanol is in the medium. Therefore, in this mutant, peroxisomes are formed and proliferate upon cultivation in glucose-containing media. In these media, LGM-128 shows induction levels of C1 metabolism that are similar to those observed in methanol-containing media. This indicates that GLR2 controls the repression-derepression process stimulated by glucose and that the induction process triggered by methanol plays only a minor role in activating C1 metabolism. Cultivating LGM-128 in methanol and then transferring it to glucose media revealed that active degradative processes occur, leading to the disappearance of C1 metabolism. This observation suggests that, although stimulated by glucose, the two processes are controlled by elements which are, at least in part, distinct. Finally, glr2-1 does not affect ethanol repression, suggesting that in H. polymorpha the two repressing circuits are separated.
In 103 patients with peripheral arterial disease (PAD) of the lower limbs, coagulation and fibrinolytic parameters were evaluated to identify hemostatic abnormalities characteristic of this patient population. PAD was defined as clinically stable Leriche stage 2 (based on clinical history, peripheral pulses, ankle-arm index, and treadmill test) for at least 3 months, walking distance > 100 m, and no other major illnesses, rest pain, or trophic lesions. Defibrotide, a polydeoxyribonucleotide derivative with vascular effects, was administered to the patients as part of a multicenter trial. The PAD patients exhibited a prothrombotic state as evidenced by high D-dimer in all but 24% of the patients (average 797 +/- 802 vs. 163 +/- 54 ng/mL normal population; p < 0.001) and high thrombin-antithrombin III complex (TAT) levels (10.2 +/- 8.9 vs. 2.5 + 1.5 ng/mL; p < 0.001) with low to normal levels of protein C (86 +/- 25 vs. 102 +/- 18%; p < 0.01) and plasminogen activator inhibitor-1 (PAI-1) antigen (5.9 +/- 4.5 vs. 1.3 + 0.7 ng/mL; p < 0.001) were elevated in 79% of the patients. These results suggest that there is ongoing thrombosis in the majority of PAD patients. Differences from normal controls were observed for t-PA, PAI-1, protein C, and protein S; however, it is not certain that the thrombosis in patients with PAD is due to these factors.
We have investigated the regulation of expression of the FOX1 gene of Saccharomyces cerevisiae which encodes acyl-CoA oxidase, the first enzyme in the peroxisomal beta oxidation of fatty acids. We have found that the FOX1 steady state mRNA level is repressed by glucose, partially induced by ethanol (but not by raffinose) and fully induced by oleic acid as a carbon source. Glucose repression was observed even if cultures were grown to stationary phase; however, if the glucose supply was limited initially then partial induction of FOX1 mRNA occurred upon growth to high cell density. A variety of mutants are known to affect the glucose repression of many genes, including the FOX3 gene which encodes the thiolase activity in peroxisomal beta oxidation. However, upon examination none of these mutants showed de-repression of FOX1 expression. Similarly we investigated the role of two inducers of genes encoding peroxisomal enzymes (namely SNF1 and ADR1). No evidence was found to suggest that either of these plays a significant role in the induction of FOX1 mRNA levels. These observations indicate that the regulation of FOX1 is under the control of as yet unidentified genes involved in catabolite repression and suggest that the regulatory circuit influencing acyl CoA oxidase activity, and hence beta oxidation and peroxisome function, is significantly different than that which might have been assumed from other studies.
The effect of octreotide, a long-acting synthetic analog of somatostatin, on fasting and postprandial splanchnic hemodynamics was investigated in cirrhotic patients. Splanchnic hemodynamics were assessed using an echo-Doppler duplex system in a prospective, double-blind, placebo-controlled, crossover study performed on 2 separate days, 1 week apart, in 30 cirrhotic patients. Measurements of portal vein (PV) cross-sectional area (PV-A) and mean velocity (PV-V), and of superior mesenteric artery (SMA) mean velocity (SMA-V) and pulsatility index (SMA-PI) (an index of vascular resistance) were performed at baseline, 30 minutes after octreotide (200 micrograms subcutaneously) or placebo administration, and 30 and 60 minutes after the ingestion of a liquid meal. In the fasted state, octreotide induced a significant decrease in PV-V (-7%) and in SMA-V (-10%) and an increase in PI (+16%). On the day of placebo administration, meal ingestion induced a significant increase in PV-V (+21%) and in SMA-V (+43%) and a decrease in PI (-21%). In contrast, meal ingestion on octreotide day induced significantly smaller increases in PV-V (+10%) and in SMA-V (+18%) and a significantly smaller decrease in PI (-10%). Octreotide, although producing a mild reduction in PV-V and SMA-V in the fasted state, markedly blunts postprandial splanchnic hyperemia in cirrhotic patients.
The haemodynamic effects on the peripheral vascular bed of L-acetylcarnitine, L-propionylcarnitine, and nitroglycerin were tested by echo-Doppler in a double blind cross-over study. Eleven male patients suffering from peripheral arterial obliterative disease (PAOD) in the second stage of Fontaine's classification, and 11 matched control subjects were enrolled in the study. Each subject received one of three different treatments on each day of the study in a different order following a random assignment. The treatments were either 30 mg x kg of L-acetylcarnitine (LAC) or 30 mg x kg of L-propionylcarnitine (LPC) or nitroglycerin (NTG) 1.25 mg given as a single i.v. bolus injected over 3 min. Echo-Doppler measurements of blood flow velocity, and cross-sectional area of the femoral artery were performed at baseline and 10, 20, and 30 min after injection of the drugs. Pulsatility Index (an index derived from the blood flow velocity and related to vascular resistance: PI = Vmax - Vmin/Vmean) was also obtained each time. Results were analysed using a Student's t-test for paired data. L-acetylcarnitine and L-propionylcarnitine showed no haemodynamic effects in either group of subjects (controls and PAOD patients) whether blood flow or vascular resistance was considered. There were haemodynamic changes (a decrease in blood flow velocity and an increase in arterial systemic resistance) only after NTG administration. The changes were more evident in controls than in PAOD patients. Femoral artery cross-sectional area showed no statistically significant effect as regards treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Color-Doppler US is currently an extremely valuable tool in the study of abdominal circulation, cirrhosis of liver and its complications, different kinds of portal hypertension, vascular/avascular liver malformations and, finally, in the evaluation of liver transplants. Moreover, its use in experimental studies has yielded good results. Even spontaneous porto-systemic shunts can be demonstrated in most cases (up to 88%). Color-Doppler allows partial obstructions to be demonstrated and permits qualitative and quantitative dynamic evaluations the presence/absence of flow, vascular masses--e.g., mean velocity measurement and blood flow assessment. The interobserver variability of the method was calculated with a double-blind study carried out by our laboratory team cooperating with a study group from the University of Yale, USA. The study evidenced how color-Doppler US cannot be used to follow the single patient unless the variations to measure are higher than variability itself. Color-Doppler limitations depend on the subjectivity of the results and on its difficult application to obese patients or to those with severe intestinal meteorism.
In order to evaluate the behavior of the portal vein cross-sectional area during changes in portal flow, two groups of subjects were analyzed in two blinded cross-over studies using echo-Doppler flowmetry. The first group (I) consisted of 21 patients with cirrhosis and 16 controls. They received a standardized meal which is known to increase portal flow. The second group (II) consisted of 31 patients with cirrhosis who received a dose of propranolol which is known to decrease portal flow. In Group I, 30 min after the meal, the portal vein blood velocity increased by 35 +/- 6% (p less than 0.01) in cirrhotic patients and by 55 +/- 5% (p less than 0.01), in normal subjects. The portal vein cross-sectional area increased significantly in normal subjects (22 +/- 2%, p less than 0.01) but not in cirrhotic patients (4 +/- 2%, n.s.). In Group II, 2 h after propranolol, there was a significant decrease in portal blood velocity (-14 +/- 2%), whereas the portal vein cross-sectional area did not show any significant changes. These data demonstrate that, in portal hypersensitive patients, the portal area measured by echo-Doppler flowmetry can be assumed to be constant and hence its calculation to estimate changes in portal blood flow can be omitted. Therefore, the use of blood velocity alone is suggested to monitor acute changes in flow in portal hypertension using Doppler flowmetry. The elimination of the portal vein cross-sectional area measurement simplifies the quantitative calculation of portal hemodynamics and increases the reliability of the technique by avoiding a source of error.
The effects of L-propionylcarnitine on walking capacity were assessed in a group of patients with peripheral vascular disease. In 12 patients, 300 mg of L-propionylcarnitine, given intravenously as a single bolus did not affect walking capacity, while 600 mg increased both initial claudication distance from the placebo value of 179 +/- 114 to 245 +/- 129 m (P less than 0.05), and maximal walking distance from 245 +/- 124 to 349 +/- 155 m (P less than 0.05). Once the efficacious dose of L-propionylcarnitine was assessed, its effect was compared to that of an equimolar dose of L-carnitine (500 mg i.v.) according to a double-blind, double-dummy, cross-over design. In 14 patients, both treatments improved walking capacity; however, the analysis of variance showed that the increase in maximal walking distance with L-propionylcarnitine was greater than that with L-carnitine (P less than 0.05). Finally, in seven additional patients, the effects of L-propionylcarnitine and L-carnitine on the haemodynamics of the affected limb were assessed by an ultrasonic duplex system. Results indicated that both drugs did not affect the blood velocity and the blood flow rate in the ischaemic leg, thus suggesting that the beneficial effect on walking capacity was dependent on a metabolic effect. In conclusion, L-propionylcarnitine improves walking capacity in patients with peripheral vascular disease, probably acting through a metabolic mechanism. On a molar basis, this beneficial effect is greater than that observed with L-carnitine and, thus, the findings of the present study may have clinical relevance in terms of treatment cost and patient compliance.
L-carnitine (L-C) is a naturally occurring substance in mammalian tissues that has recently been proposed as a therapeutic agent in hepatic encephalopathy and liver steatosis. L-C also produces some acute, non-metabolic, haemodynamic effects that have not previously been studied in patients with cirrhosis. Therefore, the authors evaluated the acute effect of i.v. administration of L-C (30 mg/kg) on systemic and splanchnic haemodynamics in ten patients (L-C group) with chronic liver disease (Child-Pugh's class A: 4, B: 3, C: 3 patients) and a control group composed of ten patients with similar clinical characteristics (Child-Pugh's class A: 5, B: 2, C: 3 patients) who received placebo. Heart rate, cardiac index and pulmonary arterial pressure (measured by right heart catheterization) decreased slightly but significantly in the L-C group and the changes observed in stroke volume were highly correlated to the Pugh's score. Moreover, the hepatic venous pressure gradient (measured by hepatic vein catheterization) decreased significantly in the L-C group, whereas no changes occurred in the placebo group. The overall response to L-C was contradictory to that previously observed in animals and humans with normal liver function, and the extent seemed to depend on the severity of liver disease. The effect of the drug on cardiac index, heart rate and hepatic venous gradient could possibly be beneficial for patients with hyperdynamic circulatory condition and portal hypertension.
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This paper correlates certain general population variables with that of the users of the Biella Mental Health Service. Age, sex, civic status and schooling are considered. Analysis of the data points to certain risk zones. The significance of these correlations is considered.
The psychiatric intervention procedure at the Emergency and Registration Department (ERD) of Biella Hospital is examined. After a short introduction in which some general data are provided regarding Health Unit no. 47 of Biella and Unit no. 48 of Cossato, the data collected by the ERD psychiatric register are analysed. Data on ERD arrival modalities are reviewed and the type of diagnosis attributed by the psychiatrist to patients examined at the ERD is examined. The various types of responses given by the psychiatrist after consultancy are then presented. The time bands in which the request for psychiatric intervention mainly fall are then noted. The paper closes with remarks on the effectiveness over time of psychiatric intervention at the ERD.
The lactose-utilizing Kluyveromyces fragilis SS-437 was found to have an associative temperature profile, but a thermotolerant growth yield behaviour. Cardinal growth temperatures were: 3 degrees C minimum for growth; 41.5 degrees C optimum; 44.5 degrees C final maximum (growth and death rates equalize); 46.1 degrees C initial maximum (maximum limit for growth).