Critical role of pH for derivatization of homocysteine with benzofurazanes.
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Chromatography, High Pressure Liquid↗
Biomedical subjects
R Testa
Publications and source records attributed to R Testa.
Beneficial effects of intracoronary adenosine as an adjunct to primary angioplasty in acute myocardial infarction.
BACKGROUND: The benefits of vessel recanalization in acute myocardial infarction (AMI) are limited by reperfusion damage. In animal models, adenosine limits reperfusion injury, reducing infarct size and improving ventricular function. The aim of this study was to evaluate the safety and feasibility of adenosine adjunct to primary PTCA in AMI. METHODS AND RESULTS: Fifty-four AMI patients undergoing primary PTCA were randomized to intracoronary adenosine or saline. The 2 groups were similar for age, sex, and infarct location. Adenosine administration was feasible and well tolerated. PTCA was successful in all patients and resulted in TIMI 3 flow in all patients given adenosine and in 19 given saline (P<0.05). The no-reflow phenomenon occurred in 1 adenosine patient and in 7 saline patients (P=0.02). Creatine kinase was lower in the adenosine group, and a Q-wave MI developed in 16 adenosine patients and in 23 saline patients (P=0.04). Sixty-four percent of dyssynergic segments improved in the adenosine group and 36% in the saline group (P=0. 001). Function worsened in 2% of dysynergic segments in the adenosine group and in 20% in the saline group (P=0.0001). Adverse cardiac events occurred in 5 patients in the adenosine group and in 13 patients in the saline group (P=0.03). CONCLUSIONS: Intracoronary adenosine administration is feasible and well tolerated in AMI. Adenosine adjunct to primary PTCA ameliorates flow, prevents the no-reflow phenomenon, improves ventricular function, and is associated with a more favorable clinical course.
Adenosine↗
Utility of alpha-glutathione S-transferase assessment in chronic hepatitis C patients with near normal alanine aminotransferase levels.
OBJECTIVES: To study whether determining alpha-glutathione S-transferase (alpha-GST) might improve the assessment of chronic hepatitis C (CHC) patients with near normal alanine aminotransferase levels (NNA). DESIGN AND METHODS: We studied 119 viraemic CHC patients. They were subdivided into two groups according to the pattern of alanine aminotransferase (ALT) alteration, i.e. consistently above (HA) or below (NNA) twice the upper normal value. In these patients we assessed alpha-GST and correlated its levels to clinical, histological, and virological findings, further evaluating whether alpha-GST might improve the assessment of CHC patients with NNA. RESULTS: alpha-GST showed a significant correlation with aminotransferases, though not with histological necroinflammatory activity and fibrosis or with hepatitis C virus RNA levels. Twenty-seven patients had NNA (23%), and within this subgroup of patients alpha-GST identified a subset of patients with a higher viral load. CONCLUSIONS: alpha-GST in CHC patients is related to hepatocellular necrosis parameters, but unrelated both to histology and to viraemia. However, in patients with NNA, alpha-GST identified a subgroup of patients with a higher viral load. In this subgroup of patients alpha-GST alteration likely represents the expression of a more severe damage. Because this injury is not detectable by the usual biochemical or histological work-up, we suggest that alpha-GST could a useful tool for monitoring liver damage over time.
Adult↗
Serum leptin levels in patients with viral chronic hepatitis or liver cirrhosis.
BACKGROUND/AIM: Serum levels of leptin, the adipocyte-derived hormone regulating food intake and energy expenditure in mammals, have been found to be increased in cirrhotic patients. The aim of the present study was to investigate leptin serum level in relation to anthropometric features and liver function in patients with viral chronic hepatitis or liver cirrhosis. METHODS: Serum leptin levels were determined by radioimmunoassay in 30 male and 10 female patients with chronic hepatitis, in 42 male and 10 female patients with liver cirrhosis, and in four respective control groups. Liver function was evaluated by the monoethylglycinexylidide formation test. Body mass index and body fat mass were estimated by weight, height and skinfold thickness measurements. RESULTS: Compared with controls, absolute serum leptin levels were significantly (p<0.01) lower in chronic hepatitis patients and similar in cirrhotic patients. Leptin serum levels were significantly (p<0.05) higher in cirrhotic than in chronic hepatitis patients. When expressed in relation to body fat mass, the above differences persisted; however, cirrhotic females showed significantly (p<0.05) higher serum leptin values than controls. Serum leptin values correlated negatively (p<0.01) with monoethylglycinexylidide serum values in all groups of patients. CONCLUSIONS: In patients with chronic viral liver disease, serum leptin levels tend to increase as liver function worsens. This may reflect a decline in the ability to downregulate energy expenditure as an adaptation to anorexia and/or to defective substrate utilisation due to liver disease and may negatively influence body weight homeostasis in these patients.
Adipose Tissue↗
Is there a role for multiple quantitative liver function tests?
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Chronic Disease↗
Oral or intravenous lidocaine administration to perform megx test?
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Administration, Oral↗
Plasma glycohydrolase levels in patients with type 1 diabetes at onset and in subjects undergoing an intravenous glucose tolerance test.
The effect of hyperglycemia and insulin deficiency on the plasma level of lysosomal glycohydrolases, namely N-acetyl-beta-D-glucosaminidase, beta-D-glucuronidase, alpha-D-galactosidase, and alpha-D-glucosidase, was investigated. Two patient groups were assessed: (1) 28 children with type 1 diabetes at onset (fasting blood glucose, 444+/-154 mg/100 mL; hemoglobin A1c, 11.9%+/-2.4%; symptom duration, 15.9+/-8 days; and absence of complications), (2) 14 adult subjects undergoing an intravenous glucose tolerance test (IVGTT), consisting of 8 non-obese subjects (body mass index, 26+/-0.04 kg/m2; fasting blood glucose, 82+/-13 mg/100 mL; blood insulin, 6+/-0.04 mU/L) and 6 obese subjects (fasting blood glucose, 97+/-3.5 mg/100 mL; blood insulin, 27+/-6 mU/L, with normal oral glucose tolerance test). Enzyme activity was determined with the fluorimetric method. The mean level of all evaluated enzymes was significantly increased in patients with type 1 diabetes at diagnosis compared with normal controls. Increased enzyme levels were also detected in the group of adults undergoing an IVGTT in whom hyperglycemia was accompanied by insulin resistance (ie, obese subjects). Glycohydrolase abnormalities appear to be related to insulin deficiency rather than hyperglycemia. Lysosomal apparatus abnormalities seem to be an inherent feature of diabetes that is present at disease onset. The possible role of insulin in the regulation of plasma glycohydrolase levels is discussed.
Adolescent↗
The monoethylglycinexylidide test does not impair psychometric performance in patients with chronic hepatitis or cirrhosis.
Lidocaine (LID) is an aminoethylamide used in hepatology to perform the monoethylglycinexylidide (MEGX) test for the evaluation of liver function in patients with cirrhosis (CIR) or chronic hepatitis (CH). The authors evaluated whether the MEGX test changes psychometric performance in patients with chronic liver disease and, in particular, whether it might trigger subclinical portosystemic encephalopathy in patients with CIR. Thirty patients with CIR and 20 patients with CH were studied. They underwent a standard-dose MEGX test, before and after which a psychometric test was administered and blood pressure, heart rate, and adverse effects were recorded. The MEGX test did not modify psychometric performance. Mean arterial blood pressure and heart rate did not change at the end of the MEGX test in either patients with CH or CIR. Adverse effects were present in 66% of all patients during lidocaine injection and lasted up to 3 minutes afterwards. They were more frequent in patients with CH than in patients with CIR (85% vs 53%). No relationship was found between adverse effects and lidocaine dosage, nor between adverse effects and MEGX or lidocaine concentration at 15 minutes. Standard-dose MEGX test does not worsen or trigger portosystemic encephalopathy in CIR. Adverse effects were frequent but mild.
Adult↗
Histologic determinants of monoethylglycinexylidide formation in patients with chronic hepatitis C.
Patients affected by chronic hepatitis C (CHC) display a peculiar histologic picture characterized by the presence of steatosis and bile duct damage in addition to evidence of inflammation, necrosis, and fibrosis. In the staging of these patients, functional evaluation may be considered a complementary tool. The monoethylglycinexylidide (MEGX) test has been used in diagnostic and prognostic assessment of chronic liver disease as a quantitative liver function test. In this study the authors evaluated whether different sampling times for the test could reflect different histologic patterns. The authors studied 82 patients with biopsy-proven CHC who underwent functional evaluation by means of MEGX test. The authors found that MEGX15 better reflected the histologic findings of necrosis and inflammation, and MEGX60 the presence of fibrosis. Neither steatosis nor bile duct damage showed a strong correlation with either sampling time. Moreover, MEGX levels showed a progressive decrease as histologic grading of chronic hepatitis progressively increased. Stepwise regression analysis identified necrosis and inflammation as histologic variables associated with both MEGX15 and MEGX30, and fibrosis as a variable associated with MEGX60. These results suggest that a decline in liver metabolic function corresponds to a progressive increase in liver damage, and that this circumstance should be taken into account when prescribing drugs to patients with CHC.
Adult↗
Influence of Helicobacter pylori eradication therapy on 13C aminopyrine breath test: comparison among omeprazole-, lansoprazole-, or pantoprazole-containing regimens.
OBJECTIVE: Proton pump inhibitors and antimicrobial agents are widely used to eradicate Helicobacter pylori (H. pylori) infection. In the general population the prevalence of infection and of polypharmacy increases the possibility of drug-drug interactions during H. pylori eradication therapy. The purpose of the present study was to assess the prevalence, degree, and clinical relevance of metabolic interference with the cytochrome P450 enzymatic system occurring during 1 wk of administration of omeprazole, lansoprazole, or pantoprazole followed by the association of clarithromycin and metronidazole for another week. The 13C aminopyrine breath test (ABT) was chosen to screen for possible interactions. METHODS: We studied 30 patients referred to our Unit for H. pylori eradication therapy. They were randomized to receive either omeprazole (20 mg b.i.d.), lansoprazole (30 mg b.i.d.), or pantoprazole (40 mg b.i.d.) for 2 wk. During the second week clarithromycin (250 mg b.i.d.) and metronidazole (500 mg b.i.d.) were added. ABT was performed before, and at the end of the first and second week of therapy. Percentage of the administered dose of 13C recovered per hour at the peak (percent 13C dose/h at the peak) and cumulative percentage of administered dose of 13C recovered over time at 120 min (percent 13C dose cum120) were the ABT evaluated parameters. RESULTS: At baseline all patients showed a normal liver function. In individual patients during treatment we observed various liver metabolic interactions both as inhibition and induction, as well as after the first and the second week of therapy. However, mean modifications of the ABT parameters during the 2 weeks of therapy were not statistically significant compared to baseline values. None of the patients who had ABT variations complained of side effects. CONCLUSIONS: H. pylori eradication therapy interferes with cytochrome P450-dependent liver metabolic activity. However, the clinical relevance of these metabolic interactions is not yet apparent, and further investigation is needed. H. pylori eradication therapy appears safe, but these interactions should be considered in the choice of proton pump inhibitor and antimicrobial agents.
2-Pyridinylmethylsulfinylbenzimidazoles↗
Leptin has no role in determining severity of steatosis and fibrosis in patients with chronic hepatitis C.
OBJECTIVE: The presence of steatosis is a common histological finding in patients with chronic hepatitis C (CHC). The causes of the severity of this condition are not yet clear, although both metabolic and viral factors supposedly are involved. In this study our aim was to examine the possible influence that leptin levels, hepatitis C virus (HCV) RNA levels, and hepatitis G virus (HGV) infection have on the severity of steatosis and on the presence and degree of fibrosis in patients with CHC. METHODS: One hundred eighty-two CHC patients with histological findings of steatosis were chosen from among a cohort of patients referred to our center for staging of liver disease. Among them 48 CHC patients were accurately selected so as to rule out possible confounding factors for the presence of steatosis (diabetes mellitus, hyperlipemia, obesity, alcohol). Leptin levels, HCV RNA levels, and HCV genotype, and the presence of HGV RNA were assessed in these patients and related to histological findings. RESULTS: We found that leptin levels in CHC patients were similar to those in healthy subjects. No relationship was found between leptin levels and severity of steatosis. HCV RNA levels, HCV genotype, and the presence of HGV infection were no different among CHC patients with various degrees of steatosis. Leptin was not related to different degrees of fibrosis, whereas higher viral load was the only parameter associated to higher fibrosis scores. CONCLUSIONS: These findings suggest that the degree of steatosis in patients with CHC does not seem to depend on serum leptin levels or on viral factors, at least as far as HCV viremia and genotype and HGV infection are concerned. The severity of fibrosis does not seem to be influenced by leptin levels, whereas HCV viral load does seem to play some role.
Adult↗
Is aspartate aminotransferase enough?
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Alanine Transaminase↗
Clinical evidence for myocardial derecruitment downstream from severe stenosis: pressure-flow control interaction.
To verify the interaction between coronary pressure (CP) and blood flow (CBF) control, we studied nine candidates for angioplasty of an isolated lesion of the left anterior descending coronary artery [i.e. , percutaneous transluminal coronary angioplasty (PTCA)]. CBF (i.e., flow velocity x coronary cross-sectional area at the Doppler tip) and CP were monitored during washout of 2-5 mCi of (133)Xe after bolus injection into the left main artery before and after PTCA. Xe mean transit time (MTT) was calculated as the area under the time-activity curve, acquired by a gamma camera, divided by the dose obtained from a model fit of the Xe curve in the anterior wall. CBF response to intracoronary adenosine (2 mg) was also assessed. PTCA increased baseline CBF (from 14.5 +/- 9.4 to 20 +/- 8 ml/min, P < 0.01), coronary flow reserve (from 1.52 +/- 0.24 to 2.33 +/- 0.8, P < 0.01), and CP (from 64 +/- 9 to 100 +/- 10 mmHg, P < 0.05). MTT decreased from 89 +/- 32 to 70 +/- 19 s (P < 0.05) after PTCA; however, MTT and CBF changes were not correlated (r = -0.09, not significant). Inasmuch as MTT is the ratio of distribution volume to CBF, MTT x CBF was used as an index of perfused myocardial volume. Volume increased after PTCA from 23 +/- 18 to 56 +/- 30 ml. A direct correlation was observed between the percent increase in distal CP and percent increase in perfused volume (r = 0.91, P < 0.01). Thus low CP was not associated with exhaustion of flow reserve but, rather, with reduction of perfused myocardial volume. These data suggest that, in the presence of a severe coronary stenosis, derecruitment of vascular units occurs that is proportional to the decrease in driving pressure. Residual perfused units maintain a vasomotor tone, thus explaining the paradoxical persistence of coronary reserve.
Angioplasty, Balloon, Coronary↗
Effect of calcium antagonists on glomerular arterioles in spontaneously hypertensive rats.
Through the use of microanatomic techniques, we investigated the effects of treatment with some dihydropyridine-type calcium antagonists (CAs) (ie, lercanidipine, manidipine, and nicardipine) and with the nondihydropyridine-type vasodilator hydralazine on hypertension-dependent glomerular injury and on the morphology of afferent and efferent arterioles in spontaneously hypertensive rats (SHR). Fourteen-week-old male SHR and age-matched normotensive Wistar-Kyoto rats were left untreated (control groups). Four additional groups of 14-week-old SHR were treated for 12 weeks with daily oral doses of 2.5 mg/kg lercanidipine, 5 mg/kg manidipine, 3 mg/kg nicardipine, or 10 mg/kg hydralazine. These treatments decreased systolic blood pressure values to a similar extent in SHR. Signs of glomerular injury, as characterized by glomerulosclerosis, hypertrophy, and an increased number of mesangial cells, were observed in control SHR. The treatment with CAs improved glomerular morphology and decreased the number of mesangial cells. Lercanidipine and manidipine were more effective than nicardipine in countering glomerular injury. In the SHR, both afferent and efferent arterioles revealed luminal narrowing, accompanied by increased wall thickness in efferent arterioles. The dihydropyridine-type derivatives that were tested decreased the luminal narrowing of afferent arterioles. Lercanidipine and manidipine countered the luminal narrowing of efferent arterioles. Hydralazine had no effect on hypertension-dependent glomerular injury or vascular changes. The present data indicate that lercanidipine and manidipine vasodilate afferent and efferent arterioles in SHR. A vasodilatory activity on efferent arteriole, which is not induced by the majority of CAs, may represent an useful property in the treatment of hypertension complicated by renal disease.
Albuminuria↗
Effects of intracavernous administration of selective antagonists of alpha(1)-adrenoceptor subtypes on erection in anesthetized rats and dogs.
The proerectile properties of three novel alpha(1)-adrenoceptor (alpha(1)-ADR) antagonists with different profiles of selectivity for the alpha(1)-ADR subtypes have been evaluated in anesthetized rats and dogs on intracavernous (IC) injection, in comparison with prazosin and phentolamine. In rats, the tested compounds decreased blood pressure (BP) and increased IC pressure (ICP), as well as the ratio ICP/BP. Rec 15/2841 (alpha(1a)- plus alpha(1L)-ADR-selective antagonist) and Rec 15/2615 (alpha(1b)-ADR selective) were the most potent compounds. The ICP/BP ratios calculated after injection of Rec 15/3039 (alpha(1d)-ADR selective) were not markedly different from those observed after vehicle injection. Prazosin and phentolamine proved poorly active, their main effect being hypotension. Approximate ED(25) values (dose of compound in micrograms inducing 25% increase of ICP/BP ratio) were Rec 15/2615 (22 microgram/kg)>= Rec 15/2841 (29 microgram/kg) > prazosin (136 microgram/kg) > phentolamine (1298 microgram/kg) > Rec 15/3039 (9600 microgram/kg). Submaximal stimulation of the cavernous nerve elicited an ICP rise whose amplitude was not altered by Rec compounds. In contrast, prazosin and phentolamine decreased this ICP rise. All compounds but 15/3039 induced significant increase of the ICP/BP ratio in dogs. Rec 15/2615 proved to be the most interesting compound, inducing significant increases of ICP/BP at doses practically devoid of effects on BP. The rank order of potency in dog in increasing the ICP/BP ratio was similar to that observed in rats. Only at the highest doses tested, all compounds, except Rec 15/3039, decreased the ICP rise elicited by submaximal stimulation of the cavernous nerve. Our data demonstrate that the alpha(1b)- and alpha(1L)-ADR subtypes are functionally relevant for the erectile function in these models, and that alpha(1b)- and/or alpha(1L)-ADR subtypes selective antagonists could represent a real advantage in erectile dysfunction therapy.
Adrenergic alpha-1 Receptor Antagonists↗
Fibronectin and lipoprotein(a) are inversely related to plasminogen activator inhibitor type-1 levels in Type 2 diabetic patients without complications.
Plasminogen activator inhibitor type-1 (PAI-1), the most important physiological fibrinolysis inhibitor, is considered an independent factor of cardiovascular risk in Type 2 diabetes mellitus (T2DM). In previous papers we demonstrated that a T2DM population without complications presents: 1) PAI-1 not increased with respect to a control group; and 2) a negative correlation between PAI-1 and lipoprotein(a) [Lp(a)], suggesting that in these subjects PAI-1 levels could be modulated by the "endothelial stress" induced by Lp(a) and diabetes. This work has been performed in order to better verify this intriguing hypothesis, and the endothelial stress has been evaluated through a marker of endothelial damage, fibronectin (FNC). For this purpose we chose a T2DM population without complications (n=73) and a control group (n=46). Plasma concentrations of FNC, Lp(a), PAI-1 antigen and activity, and the main parameters of lipo- and glycometabolic balance were determined. Fibronectin was significantly higher in diabetics with respect to controls (p<0.01). As expected, significant correlation between PAI-1 antigen, PAI-1 activity and Lp(a) (r=-0.54,p<0.01 and r=-0.39,p<0.01, respectively) was found only in diabetic patients. In the same group FNC showed a significant correlation with PAI-1 antigen and activity (r=-0.49,p<0.01 and r=-0.47; p<0.01, respectively), while no relationship was found between Lp(a) and FNC. Multiple regression analysis showed statistically significant correlation between PAI-1 antigen and PAI-1 activity with FNC and Lp(a) in diabetic patients without complications (p<0.05). These data suggest that in absence of complications, the endothelium is able to modulate PAI-1 levels, favouring in that way the fibrinolytic pathway and, subsequently, the recovery of the endothelial integrity. This modulation seems to be related to parameters such as Lp(a) and FNC, although the mechanisms of the endothelial stress of these two molecules seem to be different.
Blood Glucose↗
Effects of alpha1-adrenoceptor antagonists on agonist and tilt-induced changes in blood pressure: relationships to uroselectivity.
We evaluated the uroselectivity of a series of alpha1-adrenoceptor antagonists by comparing their potency against phenylephrine-induced increases in urethral perfusion pressure and diastolic blood pressure in the anesthetized rabbit and pithed rat. In the rabbit, Rec 15/2739 (N-[3-[4-(2-methoxyphenyl)-1-piperazinyl]propyl]-3-methyl-4-oxo-2-phenyl -4H-1-benzopyran-8-carboxamide) as well as analogs with a chlorine substituent on the methoxyphenyl ring (Rec 15/2869) or this substituent combined with the replacement of the phenyl substituent on the pyran ring by cyclohexyl (Rec 15/3011) were 2-6-fold more potent against the urethral vs. vascular response to phenylephrine. Rec 15/2841 (N-[3-[4-(2-methoxyphenyl)-1-piperazinyl]propyl]-3-methyl-4-oxo-2-cyc lohexy-4H-1-benzopyran-8-carboxamide) was only 1.5-fold more potent against the urethral response. SL 89.0591 and tamsulosin also showed selectivity for the urethral response (2-2.5-fold), while the quinazolines produced equipotent blockade of urethral and vascular responses (selectivity ratio = 0.9-1.1). The urethral selectivities of Rec 15/2739 and its derivatives were confirmed by evaluation of the response to tilt in sedated, hypovolemic rabbits. Phenylephrine challenge assays did not show any of the antagonists, with the exception of terazosin at 300 microg kg(-1), to be uroselective in the rat (selectivity ratios = 0.2-1.5); potentiation of tilt-induced hypotension in the anesthetized rat showed substantial differences from the rabbit, with Rec 15/2739, but not Rec 15/3011 and Rec 15/2841 showing orthostatic effects equivalent to that observed for prazosin. Hence, Rec 15/2739 was uroselective in the rabbit, but not in the rat, while two of its close structural analogs were highly uroselective in both species. An assay for orthostatic activity in the conscious rat yielded different results, showing prazosin and terazosin, but not Rec 15/2739, to cause a reversal of the pressor response to tilt. Hence, the apparent uroselectivity of an alpha1-adrenoceptor antagonist is both species- and assay-dependent.
Adrenergic Agonists↗
Synthesis, pharmacological evaluation, and structure-activity relationship and quantitative structure-activity relationship studies on novel derivatives of 2,4-diamino-6,7-dimethoxyquinazoline alpha1-adrenoceptor antagonists.
A new series of novel piperazine and non-piperazine derivatives of 2, 4-diamino-6,7-dimethoxyquinazoline was synthesized and evaluated for binding affinity toward alpha1-adrenergic and other G-protein-coupled aminergic receptors. The alpha1-adrenoceptor (AR) subtype selectivity was also investigated for the most interesting compounds. Only compound 16 showed moderate selectivity toward the alpha1b-AR subtype. Selected compounds were tested in vivo in a dog model indicating activity on blood pressure and on the lower urinary tract. Compound 10 showed in vivo potency close to that of prazosin. Powerful interpretative and predictive theoretical QSAR models have been obtained. The theoretical descriptors employed in the rationalization of the alpha1-adrenergic binding affinity depict the key features for receptor binding which can be summarized in an electrostatic interaction between the protonated amine function and a primary nucleophilic site of the receptor, complemented by short-range attractive (polar and dispersive) and repulsive (steric) intermolecular interactions. Moreover, on predictive grounds, the ad hoc derived size and shape QSAR model developed in a previous paper (Rastelli, G.; et al. J. Mol. Struct. 1991, 251, 307-318) proved to be successful in predicting nanomolar alpha1-adrenergic binding affinity for compound 28.
Adrenergic alpha-1 Receptor Antagonists↗