Oxidative and Nitrosative Pattern in Circulating Leukocytes of Very Early/Early Hepatocellular Carcinoma Patients.

Background/aim: In chronic liver disease, various immune cell subsets exert pro or anti-tumour effects by releasing reactive oxygen and nitrogen species (ROS, RNS). Here, we evaluated the oxidative and nitrosative pattern in peripheral blood leukocyte subpopulations of early hepatocellular carcinoma (HCC) patients compared with HCC-free cirrhotic patients.

Materials And Methods: Venous blood samples from 18 HCC-free cirrhotic patients and 17 early stage HCC patients were collected to determine ROS, RNS and reduced glutathione levels in isolated leukocytes analyzed by flow cytometry.

Contractile responses of human thyroid arteries to vasopressin.

Aims: In the present study we investigated the intervention of nitric oxide and prostacyclin in the responses to vasopressin of isolated thyroid arteries obtained from multi-organ donors.

Main Methods: Paired artery rings from glandular branches of the superior thyroid artery, one normal and the other deendothelised, were mounted in organ baths for isometric recording of tension. Concentration-response curves to vasopressin were determined in the absence and in the presence of either the vasopressin V1 receptor antagonist d(CH2)5Tyr(Me)AVP (10(-8)M), the nitric oxide synthase inhibitor N(G)-monomethyl-l-arginine (L-NMMA, 10(-4)M), or the inhibitor of prostaglandins indomethacin (10(-6)M).

Basal release of nitric oxide in the mesenteric artery in portal hypertension and cirrhosis: role of dimethylarginine dimethylaminohydrolase.

Background And Aim: Increased basal release of nitric oxide (NO) in the splanchnic circulation contributes to elevated plasma levels of NO observed in decompensated cirrhosis. We evaluated in rat mesenteric arteries whether the differences in basal release of NO, revealed by asymmetric dimethylarginine (ADMA)- and N(G) -nitro-L-arginine methyl ester (L-NAME)-induced contractions, were associated with changes in messenger RNA (mRNA) expression of endothelial NO synthase (eNOS) and dimethylarginine dimethylaminohydrolases (DDAHs).

Methods: Rat small mesenteric arteries from 14 Sham-control, from 14 with partial portal vein ligation (PPVL), and from 14 with bile duct excision (BDE)-induced cirrhosis were precontracted under isometric conditions with norepinephrine, and additional contractions were induced with ADMA and L-NAME.

Role of Ca(2+)-activated K(+) channels and Na(+),K(+)-ATPase in prostaglandin E(1)- and E(2)-induced inhibition of the adrenergic response in human vas deferens.

We studied the role of K(+) channels and Na(+),K(+)-ATPase in the presynaptic inhibitory effects of prostaglandin E(1) (PGE(1)) and PGE(2) on the adrenergic responses of human vas deferens. Furthermore, we determined the effects of increasing extracellular K(+) concentrations ([K(+)](o)) and inhibition of Na(+),K(+)-ATPase on neurogenic and norepinephrine-induced contractile responses. Ring segments of the epididymal part of the vas deferens were taken from 45 elective vasectomies and mounted in organ baths for isometric recording of tension.

Modulation of adrenergic responses of human vas deferens by K+ channel inhibitors.

Objectives: The present study was designed to evaluate the role of K(+) channels in the adrenergic responses of human vas deferens as well as the intervention of dihydropyridine-sensitive Ca(2+) channels on modulation of adrenergic responses by K(+) channel inhibitors.

Methods: Ring segments of the epididymal part of the vas deferens were taken from 32 elective vasectomies and mounted in organ baths for isometric recording of tension. We then studied the effects of K(+) channel blockers on neurogenic and norepinephrine-induced contractile responses.

Unchanged plasma levels of dimethylarginines and nitric oxide in chronic hepatitis C.

Objective: Previous studies have shown that asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and nitric oxide (NO) play a prominent role in liver dysfunction. The objective of this study was to determine whether plasma levels of ADMA, SDMA and NO are altered in patients with chronic hepatitis C.

Material And Methods: Plasma levels of ADMA, SDMA and NO (nitrite plus nitrate) were measured in 22 patients with chronic hepatitis C and 24 patients with sustained virologic response after treatment with peginterferon plus ribavirin.

Effects of aspirin, nimesulide, and SC-560 on vasopressin-induced contraction of human gastroepiploic artery and saphenous vein.

Objective: The present experiments were designed to evaluate differences in the effects of cyclooxygenase (COX)-1 and COX-2 inhibition on contractile responses of human gastroepiploic artery and saphenous vein elicited by vasopressin.

Design: Laboratory investigation.

Setting: University laboratory.

Contractile hyporesponsiveness to norepinephrine of forearm veins in chronic renal failure.

Background: We recently reported that endothelium-dependent relaxation is impaired in forearm veins from patients with chronic renal failure. However, assessment of responses to norepinephrine remains controversial. We examined the contractile response to norepinephrine in forearm veins from patients on chronic hemodialysis and the role of nitric oxide (NO), prostanoids, and Ca(2+)-activated K(+) channels in this response.

Nitric oxide mediates abnormal responsiveness of thyroid arteries in methimazole-treated patients.

Objective: We studied the intervention of nitric oxide (NO), prostacyclin and endothelium-derived hyperpolarizing factor (EDHF) in mediating responses to acetylcholine in thyroid arteries from euthyroid and methimazole-treated (MT) patients.

Design And Methods: Branches of the superior thyroid artery were obtained from 19 euthyroid patients and 17 MT patients (euthyroid at the time of surgery) undergoing total thyroidectomy or hemithyroidectomy. Artery rings were suspended in organ baths for isometric recording of tension.

Endothelium-dependent responses in human isolated thyroid arteries from donors.

The functional properties of the endothelium of human thyroid arteries remain unexplored. We investigated the intervention of nitric oxide (NO), prostacyclin (PGI(2)) and endothelium-derived hyperpolarizing factor (EDHF) in the responses to acetylcholine and noradrenaline in isolated thyroid arteries obtained from multi-organ donors. Artery rings were suspended in organ baths for isometric recording of tension.

Ca2+-activated K+ channels mediate relaxation of forearm veins in chronic renal failure.

Background: In arteries, agonists such as acetylcholine release an endothelium-derived hyperpolarizing factor (EDHF) that is neither nitric oxide nor prostacyclin.

Objectives: To examine the responses to acetylcholine in segments of forearm veins from patients with chronic renal failure who either had never received dialysis or had undergone long-term dialysis, and to determine the contribution of nitric oxide and EDHF to endothelium-dependent relaxation in veins from patients with chronic renal failure.

Methods: Isometric tension was recorded in rings of forearm vein from 34 non-dialysed patients, 27 dialysed patients and 14 multiorgan donors (controls).

Influence of nitric oxide on neurogenic contraction and relaxation of the human gastroepiploic artery.

Background: The objective of this study was to characterize the neurogenic contraction and relaxation of the human gastroepiploic artery and to determine whether the responses are mediated by nitric oxide (NO) from neural or endothelial origin.

Methods: Rings of human gastroepiploic artery were obtained from 18 patients (12 men, 6 women) undergoing gastrectomy. The rings were suspended in organ baths for isometric recording of tension.

Plasma concentration of asymmetric dimethylarginine, an endogenous inhibitor of nitric oxide synthase, is elevated in hyperthyroid patients.

Cardiovascular manifestations are frequent findings in patients with thyroid hormone disorders. Nitric oxide (NO) plays a key role in vascular, endothelial-mediated relaxation. NO is synthesized from L-arginine by NO synthase, an enzyme inhibited by endogenous compounds, mainly asymmetric dimethylarginine [asymmetric N(G),N(G)-dimethyl-L-arginine (ADMA)].

Relaxation and cGMP formation in response to sildenafil and sodium nitroprusside in saphenous veins from normotensive and hypertensive patients.

Background: This study was designed to measure cyclic guanosine 3'5' monophosphate (cGMP) formation and relaxation response to sildenafil given either alone or in combination with sodium nitroprusside in saphenous veins obtained from normotensive and hypertensive patients.

Methods: Saphenous vein rings were obtained from 13 hypertensive and nine normotensive patients undergoing coronary artery bypass surgery. The vein rings were suspended in organ bath chambers for isometric recording of tension.

Relaxation induced by milrinone and rolipram in human penile arteries and veins.

We studied the relaxant effects of milrinone, an inhibitor of phosphodiesterase 3, and rolipram, an inhibitor of phosphodiesterase 4, on contracted human penile dorsal artery and deep dorsal vein. Vascular rings from 12 multi-organ donors were suspended in organ baths for isometric recording of tension. Both milrinone and rolipram inhibited (100%) the contraction induced by noradrenaline and shifted the relaxation-response curves to the cAMP forming agents prostaglandin E(1) and forskolin to the left.

Increased contraction to noradrenaline by vasopressin in human renal arteries.

Objective: Arginine vasopressin (AVP) not only acts directly on blood vessels through vasopressin V1 receptor stimulation but also may modulate adrenergic-mediated responses in animal experiments. The aim of the present study was to assess whether subpressor concentrations of AVP could contribute to an abnormal adrenergic contractile response of human renal arteries.

Methods: Renal artery rings were obtained from 27 patients undergoing nephrectomy.