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Multidrug resistance (MDR) in cancer cells is often caused by the high expression of the plasma membrane drug transporter P-glycoprotein (Pgp) associated with an elevated intracellular glutathione (GSH) content in various human tumors. Several chemosensitizers reverse MDR but have significant toxicities. Antiemetic medications are often used for controlling chemotherapy-induced nausea and vomiting in cancer patient. In this in vitro study we investigated if the effects of two common antiemetic drugs such as dimenhydrinate (dime) and ondansentron (onda) and a natural compound (6)-gingerol (ginger), the active principle of ginger root, interfere on Pgp activity and intracellular GSH content in order to evaluate their potential use as chemosensitizing agents in anticancer chemotherapy. The human doxorubicin (doxo) resistant uterine sarcoma cells (MES-SA/Dx5) that overexpress Pgp, were treated with each antiemetic alone (1, 10 and 20 microM) or in combination with different doxo concentrations (2, 4, and 8 microM). We measured the intracellular accumulation and cytotoxicity of doxo (MTT assay), the cellular GSH content (GSH assay) and ROS production (DFC-DA assay), in comparison with verapamil (Ver), a specific inhibitor for Pgp, used as reference molecule. We found that exposure at 2, 4 and 8 microM doxo concentrations in the presence of dime, onda and ginger enhanced significantly doxo accumulation and cytotoxicity on resistant MES-SA/Dx5 cells when compared with doxo alone. Moreover, treatment with ginger (20 microM) increased cellular GSH content (greater than 10 percent) in resistant cells, while ROS production remained below the control values for all antiemetic compounds at all concentrations. These findings provide the rationale for innovative clinical trials of antiemetics or their derivatives as a new potential generation of chemosensitizers to improve effectiveness of the anticancer drugs in MDR human tumours.

Multidrug resistance (MDR) to anticancer chemotherapy is often mediated by the overexpression of the plasma membrane drug transporter P-glycoprotein (Pgp) encoded by multidrug resistance gene (MDR1). Various chemosensitizing agents are able to inhibit Pgp activity but their clinical application is limited by their toxicity. Furthermore, hepatotoxicity related to chemotherapy causes delays of treatment in cancer patients and often requires supplementation of anti-tumour therapy with hepatoprotective agents. In this in vitro study, we investigated the effectiveness of an endogenous hepatoprotective agent, S-adenosylmethionine (SAMe), and a natural hepatoprotective compound, Cynarin (Cyn), to inhibit Pgp activity in order to evaluate their potential use as chemosensitizing agents. Human doxorubicin (doxo) resistant uterine sarcoma cells (MES-SA/Dx5) expressing high levels of Pgp were treated with two hepatoprotectors at various concentrations (1, 5 and 10 microM) that are clinically achievable, in the presence or absence of three different concentrations of doxo (2, 4 and 8 microM). In order to evaluate the effects of both hepatoprotectors, we measured the intracellular accumulation and cytotoxicity of doxo, the cellular GSH level, ROS production and catalase (CAT) activity. We found that treatment with 2, 4 and 8 microM doxo in the presence of SAMe or Cyn significantly increased the doxo accumulation and cytotoxicity on MES-SA/Dx5 cells, when compared to control cells receiving doxo alone. Moreover, treatment with SAMe or Cyn significantly increased GSH content, greater than 80 percent and 60 percent, respectively) and CAT activity greater than 60 and 150 percent, respectively) in resistant cancer cells, while ROS production was below the values of corresponding untreated control cells. Our in vitro findings provide a rationale for the potential clinical use of these hepatoprotectors both as chemosensitizing agents, to reverse Pgp-mediated MDR, and as antioxidants to protect normal cells from chemotherapy-induced cytotoxixity.

Multidrug resistance (MDR) to cancer therapy is frequently associated with the over-expression of the multidrug transporter MDR1 gene product P-glycoprotein (Pgp) in several types of human tumours. Various chemosensitizers have been used to inhibit Pgp activity but toxicity limits their clinical application. Di(2-ethylhexyl)phthalate (DEHP) is a plasticizer that is released from polyvinyl chloride (PVC) medical devices. Therefore, cancer patients undertaking chemotherapy are exposed to a clinically important amount of DEHP through blood and blood component transfusions, apheresis products, intravenous chemotherapy, parenteral nutrition and other medical treatments. The present study was designed to investigate the effects of DEHP on transport activity and expression of Pgp in order to evaluate its potential use as a chemosensitizer in cancer therapy. Human doxorubicin (doxo) resistant sarcoma cells (MES-SA/Dx5) that over-express Pgp were treated with different doses of doxo (2, 4 and 8 μM) in the presence or absence of various concentrations of DEHP (3, 6 and 12 μM) that were clinically achievable in vivo. Our results show that co-treatment with 2, 4 and 8 μM doxo in the presence of the lowest concentration of DEHP (3 μM) enhanced significantly doxo accumulation in MES-SA/Dx5 cells and, consistently increased the sensitivity to doxo, when compared to controls receiving only doxo. In contrast, higher DEHP concentrations (6 and 12 μM) induced MES-SA/Dx5 to extrude doxo decreasing doxo cytotoxicity toward resistant cells below control values. These results are consistent with the increase in Pgp expression levels in parental MES-SA cells treated with 3, 6 and 12 μM DEHP for 24 h and compared to untreated controls. All in all, these findings suggest a potential clinical application of DEHP as a chemosensitizer to improve effectiveness of the antineoplastic drugs in MDR human tumours.

Multidrug resistance (MDR) in cancer cells is often caused by the high expression of the plasma membrane drug transporter P-glycoprotein (Pgp) associated with an elevated intracellular glutathione (GSH) content in various human tumors. Several chemosensitizers reverse MDR but have significant toxicities. Sedatives are often used to control anxiety and depression in cancer patients. In this in vitro study we investigated the effects of three plant derived sedatives such as apigenin (Api), fisetin (Fis), flavonoids and honokiol (Hnk) on Pgp activity and cellular GSH content in order to evaluate their potential use as chemosensitizing agents in anticancer chemotherapy. Human doxorubicin (doxo) resistant uterine sarcoma cells (MES-SA/Dx5) that overexpress Pgp, were treated with each sedative alone (10 microM) or in combination with different doxo concentrations (2-8 microM). We measured the intracellular accumulation and cytotoxicity of doxo (MTT assay), the cellular GSH content (GSH assay) and ROS production (DFC-DA assay), in comparison with verapamil (Ver), a specific inhibitor for Pgp, used as reference molecule. We found that exposure at 2 and 8 microM doxo concentrations in the presence of Api, Fis and Hnk enhanced significantly doxo accumulation by 29+/-3.3, 20+/-4.8, 24+/-6.6 percent and 14+/-1.7, 8.3+/-4.2, 10.7+/-3.1 percent, respectively, when compared with doxo alone. These results were consistent with the increase of sensitivity towards doxo in MES-SA/Dx5, resulting in 1.7, 1.2, 1.4-fold and 1.2, 1.0 and 1.1-fold increases, respectively. Moreover, treatment with Api decreased markedly cellular GSH content (18 percent) and increased ROS production (greater than 20 percent) on MES-SA/Dx5 cells, while a significant reduction in ROS levels was observed in Hnk and Fis treated cells, when compared to untreated control. Our in vitro findings provide a rationale for innovative clinical trials to assess the use of natural sedatives or their derivatives as potential adjuvants to anticancer treatment for overcoming multidrug resistance Pgp-mediated in cancer patients.

The resistance of Helicobacter pylori to antibiotics has been advocated as a major cause of treatment failure, and antimicrobial sensitivity testing has been proposed to improve efficacy; however, its role before first-line therapy has not been investigated in detail.To assess whether antimicrobial sensitivity testing improves the eradication rate of first-line anti-Helicobacter treatments and to compare the effectiveness of ranitidine bismuth citrate and omeprazole in the presence of H. pylori resistance to antibiotics.Two hundred and forty-two patients were assigned to either empirical or antimicrobial sensitivity testing-based treatment; within each group, subjects were further randomized to receive ranitidine bismuth citrate, 400 mg b.d., tinidazole, 500 mg b.d., and clarithromycin, 500 mg b.d., or omeprazole, 20 mg b.d., clarithromycin, 500 mg b.d., and amoxicillin, 1 g b.d., for 1 week, with substitution of the resistant antibiotic in the antimicrobial sensitivity testing-based treatment group.Eradication rates were 67% [confidence interval (CI), 55-79%] in the empirical treatment group and 76% (CI, 65-87%) in the antimicrobial sensitivity testing-based group (P=N.S.). The overall success rate was 60% (CI, 51-69%) with omeprazole and 82% (CI, 73-91%) with ranitidine bismuth citrate (P0.03); the latter overcame antibiotic resistance in 12 of 15 strains vs. zero of eight strains by omeprazole.Antimicrobial sensitivity testing before first-line treatment does not improve the eradication rate, which is greater when ranitidine bismuth citrate is included in the treatment.

Lipoprotein oxidation is crucial in atherogenic processes. Amiodarone is a lipophilic antiarrhythmic/antianginal drug which is able to influence the physicochemical status of biological lipid components. Since oxidation of lipids is affected by their physicochemical state and amiodarone binds to lipoproteins, we hypothesized that the drug may exert an antioxidant activity on human lipoprotein oxidation. Dose-dependent effects of therapeutically achievable amiodarone concentrations (1.5, 3, 5, 7 and 10 microM) were studied on copper-catalysed oxidation of the non-HDL fraction in vitro. Amiodarone inhibited oxidation as judged by generation of thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH) and fluorescent products of lipoperoxidation (FPL) as well as from the kinetics of conjugated diene formation. This antioxidant activity was significant at 1.5 microM with total inhibition at 10 microM and an IC(50) of 4 microM. The primary in vivo metabolite of amiodarone, namely desethylamiodarone, also exhibited specific antioxidant properties although it was less effective than amiodarone with an IC(50) of 7 microM. In further in vivo experiments, susceptibility to copper-mediated oxidation of the non-HDL fraction was investigated before and 4 weeks after oral amiodarone administration to humans. Following treatment, significant inhibition of TBARS, LOOH and FPL generation was observed in comparison with baseline levels and a placebo-treated control group, highlighting an effective antioxidant capacity of amiodarone in vivo. Amiodarone did not change lipoprotein vitamin E and phospholipid content in vivo and did not show scavenging effects on oxidizing species involved in lipoprotein oxidation, such as peroxyl radicals, nor metal-binding/inactivating properties, suggesting that physicochemical modifications of lipoprotein lipids induced by the lipophilic drug may be involved in its antioxidant activity. In conclusion, amiodarone, and its primary metabolite desethylamiodarone, show previously unrecognized antioxidant activity on human lipoprotein oxidation. This effect is also evident in vivo and at therapeutically achievable drug concentrations. Thus, amiodarone may act as an antioxidant/antiatherosclerotic agent in humans, although this issue warrants further clinical study.

It has recently been proposed that increased oxidative stress may play a role in the aging process and age-associated degenerative diseases.A cross-sectional study was carried out to assess the relationship of circulating antioxidants, namely vitamins E and C, beta-carotene, proteic thiols (P-SH) and ceruloplasmin, and of lipid peroxides, with both aging and aging with disability, i.e., unsuccessful aging.One hundred healthy free living and 62 disabled octo-nonagenarians and 91 healthy adults were enrolled in the study.Free living and disabled older adults had lower antioxidant and higher lipid peroxide levels than healthy adults, as well as the disabled older adults compared with free living older persons. Using logistic regression, we observed that plasma concentrations of vitamins E and C, P-SH, and lipid peroxides were independently associated with either aging or aging with disability, apparently representing biochemical indicators of patient status. In particular, aging and unsuccessful aging were associated with higher levels of lipid peroxides independently of circulating levels of vitamins C and E, suggesting that the increased oxidative stress was not merely an effect of a lower dietary intake of antioxidants. Serum ceruloplasmin was significantly higher in free living older adults than in healthy adults, and in the disabled compared with free living octo-nonagenarians.Our findings are consistent with the presence of systemic oxidant load in older adults, and this phenomenon is far more evident in unsuccessful aging.

To evaluate vascular structural changes in hypertensive patients with different patterns of left ventricular geometry.From 250 untreated hypertensive patients who underwent ambulatory blood pressure monitoring and echocardiographic study, we selected four groups matched for sex, age, body mass index, smoking habits and serum lipid values: 25 hypertensive subjects with normal left ventricular geometry, 16 with concentric left ventricular remodeling, 26 with concentric left ventricular hypertrophy and 18 with eccentric non-dilated left ventricular hypertrophy. These patients underwent carotid ultrasonography to evaluate the intimal-medial thickness and lumen diameter, and venous occlusion plethysmography to record minimum forearm vascular resistance (an index of arteriolar structural changes).The intimal-medial thickness and minimum forearm vascular resistance were significantly higher (both P0.05) in hypertensive subjects with concentric left ventricular remodeling (0.95 mm, 2.68 RU) and concentric left ventricular hypertrophy (0.96 mm, 2.71 RU) than in those with eccentric non-dilated left ventricular hypertrophy (0.81 mm, 2.36 RU) and normal left ventricular geometry (0.71 mm, 2.15 RU). There was no difference between hypertensive patients with concentric left ventricular remodeling and concentric left ventricular hypertrophy. The intimal-medial thickness and minimum forearm vascular resistance tended to be higher in hypertensive subjects with eccentric non-dilated left ventricular hypertrophy than in those with normal left ventricular geometry, but this difference did not attain statistical significance.This study shows that the spectrum of cardiac adaptation to hypertension is associated with a spectrum of vascular adaptation which might be related both to hemodynamic stimuli and differences in the expression or activity of vascular growth factors.

In 10 severe hypertensives the effects of intravenous administration of scalar doses of captopril were evaluated. The behaviour of blood pressure, heart rate, electrocardiographic pattern and left ventricular (LV) diastolic function, in basal condition (T0) and after 60 min of captopril infusion (T60), were analysed. Diastolic performance was assessed by pulsed wave Doppler echocardiography, evaluating transmitral peak flow velocities in early diastole (PEDV), late diastole (PLDV) and the PEDV/PLDV ratio. All patients showed an increase in LV mass (assessed by M-mode echocardiography) and altered diastolic performance, documented by high PLDV and low PLDV/PEDV ratio values. Clinical, haematological, urinary and biochemical data were also assessed for possible side effects. Captopril significantly reduced BP in 7 out of the 10 patients. Supine BP decreased from 212 +/- 15.3/126 +/- 5.6 to 171 +/- 17.7/98 +/- 11.8 mmHg (T0 vs. T60 P less than 0.0001). No electrocardiographic abnormality was observed during the study. The goal of antihypertensive effect was reached at 40-50 min after the onset of captopril therapy. Heart rate showed a small but constant decrease (from 76 +/- 7.7 to 72.8 +/- 5.7 beats/min, T0 vs. T60, P less than 0.05). Side effects of intravenous captopril were always mild and transient; no severe hypotension as 'first dose effect' was observed in our study. The echocardiographic data showed a significant decrease in LV end-systolic dimension after captopril infusion, while left atrial, LV diastolic dimension and fractional shortening remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Liquid gastric emptying has been evaluated in 17 normal human subjects during basal conditions, after mild physical stress at 50% of the maximum predictable heart rate, and after maximal physical stress at 70% maximum heart rate. Each subject exercised on a treadmill for 30 min, its speed and inclination varied in order to obtain the desired heart rate. Immediately after the exercise, 400 ml of mineral water were drunk by each subject. Gastric emptying was evaluated by real-time ultrasonography (11 subjects) and scintigraphy (six subjects) through previously described methods. The results show similar data with both techniques. Gastric emptying of the water, considered either as reduction in gastric measurements at ultrasonography or decay in radioactivity in the region of interest corresponding to the stomach at scintigraphy, follows a linear relationship under basal conditions and during physical stress. Compared with basal conditions, gastric emptying of water after maximal stress was prolonged; after mild stress, gastric emptying of the water was accelerated. These findings may support the common belief that mild physical activity favors the digestive process.

Summary Myocardial energy balance strictly depends on oxydative substrate metabolism. In a fasting state FFA are the main energy source and in a fed state the heart uses mainly carbohydrates. The metabolic pattern is largely influenced by myocardial ischemia. Lactate production is the most important marker of the ischemic heart but its venous release in coronary sinus is strongly dependent on the degree of ischemia. During severe ischemia lactate production and release by the ischemic cell are inhibited; during mild ischemia, myocardial lactate production and coronary venous release are enhanced. FFA metabolism is also influenced by the various degrees of myocardial ischemia; their storage in the cell may contribute to arrhytmias, which often complicate myocardial infarction. During hypertrophy, the metabolic pattern does not differ substantially from normal. Hypertrophy is however the first step towards heart failure. Impaired calcium turnover, nucleic acids and protein synthesis, catecholamine deficiency and defects during the phases of the energy cycle, contribute to a progressive reduction in myocardial contractility. Ischemia-dependent heart failure is strongly connected to intracellular acidosis, by specific competition between H + and Ca ++ ions at the troponin level. The metabolic disorder is negatively influenced by digitalis, which enhances myocardial oxygen consumption, lactate production and, consequently, intracellular acidosis.

Dose-response curves for cholecystokinin (CCK), cerulein (CRL), and the effect of atropine on peptide-induced gallbladder evacuation, were evaluated in 13 normal subjects. Gallbladder volume was monitored by means of real-time ultrasonography. After an overnight fast, CCK was infused in six subjects iv, with increasing doses from 0.002 IDU/kg/min for 15 min, and CRL in seven subjects from 0.5 ng/kg/min for 5 min, until maximum gallbladder evacuation (greater than 70% of the fasting volume) was achieved. Forty-eight hours after the first study, CCK and CRL were readministered at the maximum contracting dose in each subject with and without a pretreatment with atropine (1 mg iv as bolus). The results showed maximum gallbladder evacuation at 0.016 IDU for CCK, and at 4 ng for CRL. Atropine significantly blunted the gallbladder response both to CCK and to CRL. It is therefore suggested that the cholinergic system is involved in the gallbladder response to CCK and to CRL.

Aim of this work has been to investigate the pattern of interdigestive motility from the esophagus to the duodenum. Six human subjects have been studied by means of a manometric probe. The results are very similar to those described elsewhere, and show that a cyclic motor activity spreads down from the esophagus to the duodenum and that a district control of gastrointestinal motility exists.

5 patients with angina had their threshold for angina evaluated by atrial pacing and by stimulation with catecholamine (dopamine). The authors then studied the metabolic changes induced by the two types of anginogenic load (AP and D-test) applied successively, and compared them with the post-ergometry ECG changes (lowering of the ST segment by at least 2 mm) and the findings on coronary arteriography (complete obstruction of at least 75% stenosis of a major branch vessel). The metabolic measurements were controlled against those of 5 normal subjects after standard ergometry. In the patients with angina, the AP test led to a constantly negative value for %. L. By contrast, the values of D(a-v)c and % O2 which were reduced in the normals, as indirect evidence of an increased coronary flow, remained practically static. During the dopamine infusion, although the % L was reduced, it remained essentially positive, while the D(a-v)c and % O2 were consistantly lowered.

In seven patients with spontaneous angina and three control subjects, aortic and coronary sinus norepinephrine and epinephrine were assessed. Samples were taken in basal conditions and during ergonovine test in coronary sinus and aorta. The behaviour of some hemodynamic parameters as heart rate, blood pressure, left ventricular end diastolic pressure and coronary sinus flow was also studied. Resting myocardial norepinephrine and epinephrine flux was similar for both groups. In ischemic patients ergonovine induced a coronary spasm accompanied by an evident reduction of coronary sinus flow and a slight increase in arterial epinephrine and norepinephrine concentrations. However, a significant decrease in the net myocardial norepinephrine and epinephrine release was evidenced. After ergonovine, not significant changes in norepinephrine and epinephrine concentration and release resulted in control subjects. The increase in peripheral catecholamine concentrations found in ischemic patients during ergonovine test could represent a reflex activation of sympathetic activity induced by an ischemia dependent ventricular mechanical disfunction. The decrease in myocardial catecholamine release during angina could be justified by sequestration of epinephrine and norepinephrine in ischemic areas induced by vasospasm or reflex inhibition of cardiac sympathetic tone.

Hemodynamic and metabolic effects of nitroglycerin ointment (40 mg nitroglycerin) were tested on 15 patients with clinical evidence of stable angina. Basal value (B) and atrial pacing (AP)-dependent changes were evaluated before and 30 min after ointment administration. After treatment tension time index (TTI) basal value showed a 19% reduction (p less than 0.05). Compared to the control a lesser AP-dependent increase was also noted (27%, compared to 45%; p less than 0.005). According to TTI reduction, MVO2 showed an evident decrease both in basal conditions and during AP (21% and 29.6%, respectively). On the contrary, diastolic pressure time index (DPTI) does not result significantly influenced by the treatment. Consequently, DPTI/TTI ratio increase is largely the result of TTI reduction, which is well correlated to myocardial oxygen demand. Coronary sinus blood flow decrease (16% and 27% under basal conditions and during AP, respectively) confirms that the therapeutic efficacy of the ointment does not result from an increase in myocardial oxygen supply. Finally, during AP nitroglycerin ointment resulted in a significant decrease in myocardial lactate release (L% mean value ranges from-17.5% to 3.4%; p less than 0.001). Such an improvement probably reflects a primary influence of the drug on the extracoronary vascular bed.

In ten angina patients responding with a myocardial anaerobic metabolic pattern to isoproterenol infusion, a new beta-blocking agent, bunitrolol, was effective in normalizing the myocardial lactate extraction ratio. The correlation with lipid metabolism was also interesting because beta-blocker action reduced significantly arterial non-esterified fatty acids (NEFA) level as well as myocardial NEFA extraction. The metabolic behavior suggests the effectiveness of bunitrolol in the treatment of ischemic heart disease.