Chemical Characterisation-Biological Evaluation of Greek Cultivar Cardoon Seeds (Cynara cardunculus). A By-product with Potential High Added Value.

Cynara cardunculus (artichoke) is a perennial plant of the Mediterranean basin, known since antiquity as food and for its therapeutic properties. Cynara is a relatively small genus with two cultivated species and one wild one. Recently, successful efforts have been made to cultivate wild cardoon and monetise it as a bioenergy crop. In this study, the seeds of an established Greek cultivar of C. cardunculus, cultivated in the experimental field and used as biofuel, have been researched for their chemical profile and nutritional value. According to the results, six lignans were isolated [arctigenin, arctiin, trachelogenin, tracheloside, cynarinine, and ethylate of trachelogenin (isolated for the first time from a natural source)] as well as the most characteristic metabolites of the genus (linoleic acid, trilinolein, and 3,5-dicaffeoylquinic acid). Moreover, the total phenolic content (31.18 - 54.51 mg gallic acid equivalents/g extract) and antioxidant and enzyme inhibitory activities of the seeds have been evaluated and showed strong antioxidant properties (44.42 - 516.81 mg gallic acid equivalents/g extract) as well as satisfactory bleaching (enzyme tyrosinase, 16.95 - 23.80 mg kojic acid equivalents/g extract), antidiabetic (enzymes a-amylase, a-glucosidase, 0.14 - 1.75 mmol acarbose equivalents/g extract), and protective against neurodegenerative disease (cholinesterase enzymes, 0.49 - 1.22 mg galanthamine equivalents/g extract) activities. The nutritional evaluation of the seeds confirmed them as a rich source of unsaturated fatty acids, dietary fibre (24.1%), and high protein content (19.3%). It is noteworthy that such a neglected bioactive by-product, with essentially high nutritional value, as the studied seeds could be investigated for its value-added applications towards food and food supplements areas.

Endothelin-1 acutely reduces the permeability of visceral sheep peritoneum in vitro through both endothelin-A and endothelin-B receptors.

Mesothelium is an important part of the peritoneal barrier for water and ion transport, essential for effective peritoneal dialysis (PD). Peritoneal fibrosis has been associated with PD treatment failure. Endothelin-1 (ET-1) is a potent vasoactive peptide, involved in pathologic fibrotic processes. Its action is mediated mainly by endothelin type A (ETA ) and type B (ETB ) receptors. The aim of this study was to investigate, by Ussing chamber experiments, the effect of ET-1 on the transmesothelial electrical resistance (RTM ) of the isolated visceral sheep peritoneum. Intact sheets of visceral peritoneum were obtained from 40 adult sheep and mounted in Ussing-type chambers. ET-1 (10(-7) M), BQ-123 (ETA receptor antagonist; 10(-6) M), BQ-788 (ETB receptor antagonist; 10(-6) M), and their combinations were added on the apical and the basolateral side of the peritoneum. RTM was measured before and serially after addition of the substances, and changes were registered as percentage (ΔRTM %). RTM increased within 1 min after addition of ET-1 apically (ΔRTM 65.03 ± 15.87%; P < 0.05) or basolaterally (ΔRTM 85.5 ± 20.86%; P < 0.05). BQ-123 and BQ-788 and their combination significantly reduced (P < 0.05) the effect of ET-1 to a similar degree in all cases. These results clearly indicate that ET-1 reduces ionic permeability of the visceral sheep peritoneum in vitro. Additionally, it is obvious that this inhibitory effect is mediated through both ETA and ETB receptors.

Spontaneous perirenal hemorrhage in end-stage renal disease treated with selective embolization.

Spontaneous nontraumatic rupture of the kidney (Wunderlich syndrome) is an extremely uncommon condition on hemodialysis. We report a case of 44-year-old hemodialysis patient presented with hemorrhagic shock and a right quadrant abdominal pain to the emergency department. There was no history of trauma. A kidney rupture was revealed by abdominal computed tomography, and active bleeding was successfully managed with arterial embolization. This case illustrates the safe and successful application of interventional radiology in the management of nontraumatic renal hemorrhage in the specific group of hemodialyzed patients even in the emergency setting.

Simultaneous clinical resolution of focal segmental glomerulosclerosis associated with chronic lymphocytic leukaemia treated with fludarabine, cyclophosphamide and rituximab.

BACKGROUND: Although renal involvement in advanced haematological malignancies is common, glomerulonephritis associated with lymphoproliferative disorders is rare, and the related pathogenetic mechanisms are still poorly understood. We present a rare case of chronic lymphocytic leukaemia(CLL)-associated focal segmental glomerulosclerosis with nephrotic-range proteinuria. CASE PRESENTATION: A 53-year-old Caucasian man, previously healthy, with no history of hypertension, alcohol use or smoking presented with rapid weight gain, massive peripheral oedema, and hypertension. Laboratory findings included a white blood cell count of 49,800 cells/mm3 with an absolute lymphocyte count of 47,000 cells/mm3, serum albumin of 2.3 g/dL, urea 65 mg/dL, and creatinine 1.5 mg/dL. A 24-hour urine collection contained 7.1 g protein and significant haematuria. A peripheral blood smear showed mature lymphocytosis and smudge cells. Diagnostic imaging showed mild paraaortic lymphadenopathy with no renal abnormalities. Bone marrow aspiration and trephine biopsy showed diffuse and focal infiltration with B-CLL lymphocytes. Percutaneous renal biopsy revealed total sclerosis in 3/21(14%) of the glomeruli and focal and segmental solidification and sclerosis in 4/21 (19%) glomeruli. A regimen of fludarabine, cyclophosphamide and rituximab was successful in inducing remission of the CLL and clinical resolution of the nephritic-range proteinuria. CONCLUSIONS: A multidisciplinary approach to monitor both the malignancy and the glomerular lesions is crucial for the optimal management of paraneoplastic glomerulonephritis. Although chemotherapy with fludarabine, cyclophosphamide and rituximab successfully treated CLL-associated nephrotic syndrome in our patient, further studies are required to confirm efficacy in this setting.

Acute renal failure: a rare presentation of hypothyroidism.

Thyroid hormones affect the function of almost every body organ, and thyroid dysfunction produces a wide range of metabolic disturbances. Severe hypothyroidism is associated with significant effects on the kidney. The pathophysiology is thought to be multifactorial, while the exact mechanism remains unclear. Hypothyroidism as a cause of renal impairment is usually overlooked, leading to unnecessary diagnostic procedures. We describe two patients with acute renal failure due to severe hypothyroidism in whom thyroid hormone substitution therapy led to a significant improvement in renal function.

Spironolactone increases permeability of visceral sheep peritoneum.

Aldosterone is a key component of the renin-angiotensin-aldosterone system, and spironolactone, an aldosterone receptor blocker, shows beneficial effects in patients with end-stage renal disease and heart failure. The aim of the present study was to investigate by means of Ussing chamber technique the effect of spironolactone on the transmesothelial permeability of visceral sheep peritoneum in vitro. Peritoneal samples from the omentum of adult sheep were collected immediately after slaughter in a cooled and oxygenated Krebs-Ringer bicarbonate (KRB) solution. Isolated intact sheets of peritoneum were mounted in an Ussing-type chamber. Spironolactone (10(-5) mol/L) was added apically and basolaterally to the KRB solution. The transmesothelial resistance (R) was measured before and serially for 30 minutes after the addition of the substances. Data present the mean +/- standard error of 6 experiments in each case. The control R was 19.8 +/- 0.36 omega x cm2. The addition of spironolactone resulted in a reduction in the R, which became significant on both sides of the membrane within 10 minutes and remained significantly different thereafter. The maximum reduction of R (deltaR%) reached 24.8% +/- 2.3% (p < 0.01) apically and 26.3% +/- 3.2% (p < 0.01) basolaterally. Our data clearly show that spironolactone increases the permeability of visceral sheep peritoneum in a lasting manner. Increased peritoneal permeability could result in increased sodium removal, which has acknowledged beneficial effects both in patients undergoing peritoneal dialysis and in patients with heart failure. Further clinical studies investigating the effect of spironolactone on sodium removal in peritoneal dialysis are justified.

Effect of cimetidine on the electrophysiologic profile of isolated visceral sheep peritoneum.

The peritoneal mesothelium is a barrier to ion transport in peritoneal dialysis. Cimetidine is an H2 receptor antagonist and a potent inhibitor of Na+/H+ antiporter, which is found in the plasma membranes of various cell types, including mesothelial cells. Recent reports linked Na+/H+ antiporter stimulation with increasing peritoneal fibroblast proliferation. The aim of the present study was to investigate by means of Ussing chamber experiments the effect of cimetidine on the transmesothelial electrical resistance (R) of isolated visceral sheep peritoneum. Peritoneal samples obtained from adult sheep were collected from the slaughterhouse and transferred in oxygenated Krebs-Ringer bicarbonate (KRB) solution to the laboratory within 30 minutes of the animal's death. The peritoneal tissue was transferred in a cooled KRB solution (4 degrees C, pH 7.5) bubbled with 95% O2/5% CO2. A planar sheet of the visceral peritoneum was mounted in an Ussing-type chamber and cimetidine (10(-3) mol/L) was added to the solution on the apical and basolateral sides. The R was measured before and for 15 minutes serially after addition of the cimetidine. Results presented are the means +/- standard error of the mean of 12 experiments. Addition of cimetidine basolaterally induced, within 1 minute, an increase in the deltaR of 35.97% +/- 12.01% (p < 0.05), which returned to baseline after 15 minutes. The action of cimetidine on the apical side of the membrane was similar, with a rapid rise in the deltaR of 47.3% +/- 16.4% (p < 0.05) and a subsequent decline to control values. The R is inversely correlated with membrane permeability. The results of the present study indicate a rapid action of cimetidine on the permeability of visceral sheep peritoneum, probably through inhibition of mesothelial Na+/H+ antiporter. The increase in R observed after addition of the cimetidine clearly indicates the existence of Na+/H+ antiporter on both sides of visceral sheep peritoneum. The clinical implications of our results should be further investigated.

Rapid effect of dexamethasone on the permeability of visceral sheep peritoneum.

The peritoneal mesothelium is a biologic barrier to water and ion transport. Its functional and structural integrity is crucial for peritoneal dialysis treatment. In vivo studies have shown that corticosteroids increase transcellular water transport and ultrafiltration of the rat peritoneum. In the present study, we used Ussing chamber technique to investigate the effect of dexamethasone on the transmesothelial permeability of the visceral sheep peritoneum in vitro. Peritoneal samples from the omentum of adult sheep were collected in a cooled and oxygenated Krebs-Ringer bicarbonate (KRB) solution immediately after the death of the animals. Isolated intact sheets were mounted in an Ussing-type chamber. Dexamethasone (10(-6) mol/L) and its inhibitor mifepristone (10(-5) mol/L) were added apically and basolaterally, alone and in combination to the KRB solution. The transmesothelial resistance (R) was measured for 1 hour before and serially after the addition of the substances. Data are expressed as mean +/- standard error of 6 experiments in each case. The control R was 21.5 +/- 0.42 omega x cm2. Dexamethasone induced a significant reduction of R within 15 minutes, which continued for the entire experiment. The maximum effect (% deltaR) was observed at 30 - 60 minutes after the addition of dexamethasone apically 46.2% +/- 7.14% (p < 0.01) and basolaterally 35.3% +/- 7.76% (p < 0.01). Mifepristone acted as an agonist on both sides of the membrane and significantly inhibited the dexamethasone effect. Our findings clearly indicate that dexamethasone rapidly increases the transmesothelial permeability of visceral sheep peritoneum. The rapid effect implicates dexamethasone and probably mifepristone as being involved in a common nongenomic pathway. Further investigation is necessary to elucidate the underlying mechanisms and perspectives of these findings.

mu-Opioid stimulation of isolated parietal sheep peritoneum decreases peritoneal permeability in vitro.

The peritoneal mesothelium is one of the main barriers to ion transport in peritoneal dialysis. In a previous study, we showed the existence of a micro-opioid influence on the in vitro ionic permeability of serosal membranes (specifically, pleura and pericardium), which become less permeable to ionic currents after the action of morphine. In the present study, we used Ussing chamber experiments to investigate the effect of morphine on the transmesothelial electrical resistance (RTM) of isolated parietal sheep peritoneum. Peritoneal samples from the diaphragm of adult sheep were isolated directly after the death of the animals and were transferred to the laboratory within 30 minutes in a cooled Krebs-Ringer bicarbonate solution (4 degrees C, pH 7.5) bubbled with 95% O2/5% CO2. A planar sheet of parietal peritoneum was mounted in an Ussing-type chamber and morphine (10(-9) mol/L) was added apically and basolaterally. The RTM was measured before and serially for 30 minutes after the addition of morphine. Because active ion transport is temperature dependent, the Ussing chamber was held at 37 degrees C. Results presented are the mean +/- standard error of 6 experiments. The control RTM (before the addition of morphine) was 20.26 +/- 0.57 Omega x cm2. Addition of morphine basolaterally induced, within 1 minute, an increase in RTM of 24% +/- 4.8%, which declined thereafter (p < 0.01). When morphine was added apically, the results were not similar, because no significant change occurred in the RTM. The RTM is an established surrogate of peritoneal permeability. The results of the present study indicate rapid action of basolaterally added morphine on the permeability of the parietal peritoneum. The observed increase in the RTM indicates the existence in the parietal peritoneum of micro-opioid receptors that seem to prevail basolaterally. The clinical implications of these results should be further investigated.

Effect of endothelin-1 on the transmesothelial resistance of isolated visceral sheep peritoneum.

The mesothelium is part of the peritoneal barrier that manages the water and ion transport essential for peritoneal dialysis (PD) treatment. In addition, it has a central role in the pathogenesis of peritoneal fibrosis and the resulting ultrafiltration failure observed in many PD patients. Endothelin-1 (ET-1) is a potent vasoactive peptide originally described as an endothelial cell-derived factor In addition, ET-1 has been shown to stimulate fibrogenic activity in various organs by regulating the production and turnover of matrix components. The aim of the present study was to investigate, by means of Ussing chamber experiments, the effect of ET-1 on the transmesothelial electrical resistance (RTM) of isolated visceral sheep peritoneum. Intact sheets of visceral sheep peritoneum were obtained from 12 adult sheep. The samples were collected from the slaughterhouse immediately after the deaths of the animals and, within 30 minutes, were transferred in oxygenated Krebs-Ringer bicarbonate (KRB) solution at 4 degrees C to the laboratory to be mounted in an Ussing-type chamber. Endothelin-1 (10(-7) mol/L) was then added to the KRB solution apically or basolaterally, and the RTM was measured before and serially for 10 minutes after the addition of the ET-1. The control RTM (before addition of ET-1) was 22.8 +/- 0.56 Omega x cm2. Addition of ET-1 apically significantly increased the RTM by 63.82% +/- 16.93% (p < 0.05) within 1 minute. After addition of ET-1 basolaterally, the RTM also increased significantly by 90.91% +/- 57.31% within 1 minute (p < 0.05). In both cases, these values persisted throughout the experiment. These results clearly indicate an inhibitory effect of ET-1 on the ionic permeability of visceral sheep peritoneum. The rapid increase in RTM observed after the addition of ET-1 suggests the existence of endothelin receptors (ET-A or ET-B, or both) on visceral sheep peritoneum. Previous studies demonstrated that ET-1, acting on ET-B receptors, potently inhibits epithelial sodium channels in mammalian cell cultures. Nevertheless, the exact pathways that underlie these findings remain unclear; their elucidation requires further investigation.

Effect of sodium-potassium pump inhibition by ouabain on the permeability of isolated visceral sheep peritoneum.

The permeability for small solutes and the ultrafiltration capacity of the peritoneum are essential for effective peritoneal dialysis (PD) treatment. Elucidation of the factors that regulate these two properties is therefore of great importance. Ouabain, a potent inhibitor of the Na+-K+ pump has been shown to reduce fluid absorption in animal models of PD. In the present study, we used Ussing chamber experiments to investigate the effect of ouabain on the transmesothelial electrical resistance (RTM) of isolated visceral sheep peritoneum. Peritoneal samples from the omentum of adult sheep were isolated immediately after the deaths of the animals and were transferred to the laboratory in cooled Krebs-Ringer bicarbonate solution (4 degrees C, pH 7.5) bubbled with 95% O2/5% CO2. A planar sheet of visceral peritoneum was mounted in an Ussing-type chamber, and ouabain (10(-3) mol/L) was added apically and basolaterally. The RTM was measured before and serially for 30 minutes after the addition of ouabain. Because active ion transport is temperature-dependent, all measurements were taken at 37 degrees C. The results presented are the mean +/- standard error of 6 experiments. Before the addition of ouabain, the control RTM was measured as 21.26 +/- 0.57 Omega x cm2. Addition of ouabain basolaterally induced an increase in the RTM to 27.62 +/- 0.72 Omega x cm2 within 1 minute (p < 0.05), and this level persisted throughout the experiment. The effect of ouabain, when added apically, was similar, characterized by a rapid rise in the RTM to 24.66 +/- 0. 76 Omega x cm2 at 1 minute (p < 0. 05), with subsequent persistence at that level. A clear association between RTM and active ion transport has been shown in previous studies. The results of the present study, showing a rapid effect of ouabain on the RTM of visceral peritoneum, therefore clearly suggest that cell membrane Na+K+-ATPase is important for peritoneal ionic transport. In addition, ouabain was previously shown to reduce vasodilation and intraperitoneal sodium or to increase intraperitoneal volume, especially in the presence of conventional acidic solutions. Those findings, combined with the results of the present study, clearly indicate that intraperitoneal administration of digitalis glycosides may have some beneficial effect in PD patients; however the specific clinical implications need further investigation.

Influence of the sodium transport inhibition by amiloride on the transmesothelial resistance of isolated visceral sheep peritoneum.

The peritoneal mesothelium is a barrier to ion transport in peritoneal dialysis. In the present study, we used Ussing chamber experiments to investigate the effect of amiloride on the transmesothelial electrical resistance (R(TM)) of isolated visceral sheep peritoneum. Peritoneal samples from the omentum of adult sheep were isolated directly after the death of the animals and were transferred to the laboratory within 30 minutes in a cooled Krebs-Ringer bicarbonate solution (4 degrees C, pH 7.5) bubbled with 95% O2/5% CO2. A visceral peritoneal planar sheet was mounted in an Ussing-type chamber and amiloride (10(-3) mol/L) was added apically and basolaterally. The R(TM) was measured before and serially for 30 minutes after the addition of amiloride. Because active ion transport is temperature dependent, the Ussing chambers were held at 37 degrees C. The results presented are the means + standard error of 12 experiments. The control R(TM) (before the addition of amiloride) was 21.86 +/- 0.46 omega x cm2. Basolateral addition of amiloride induced, within 1 minute, an increase in R(TM) to 27.26 +/- 0.39 omega x cm2, a level that persisted throughout the experiment. When amiloride was added apically, the results were similar with a rapid rise of R(TM) to 24.18 +/- 0.9 omega x cm2 and subsequent value persistence (p < 0.05). A clear association between R(TM) and active ion transport was shown in previous studies. The results of the present study indicate rapid action of amiloride on the permeability of the visceral peritoneum. The observed increase in the R(TM) indicates the existence of amiloride-sensitive sodium channels in the visceral peritoneal membrane. The clinical implications of these results should be further investigated.

Amiloride-sensitive sodium channels on the parietal human peritoneum: evidence by ussing-type chamber experiments.

The mesothelium is part of the peritoneal water and ion transport barrier essential for peritoneal dialysis (PD) treatment and has a central role in the pathogenesis of peritoneal fibrosis and ultrafiltration failure observed in many PD patients. We investigated the effect of amiloride on the transmesothelial electrical resistance (RTM) of isolated parietal human peritoneum. Intact sheets were obtained from seven patients (three men, four women; mean age, 64 +/- 8 years). Fourteen peritoneal planar sheets were transferred to the laboratory in oxygenated Krebs-Ringer bicarbonate solution at 4 degrees C within 30 minutes after removal and mounted in an Ussing-type chamber. Amiloride (10(-3) mol/L) added apically (n = 8) caused a rapid rise of the RTM to 24.15 +/- 0.76 [OMEGA]H cm2 and a subsequent value persistence (p < 0.05); added basolaterally (n = 6), it increased the RTM to 22.66 +/- 0.59 [OMEGA]H cm2 within 1 minute, which persisted throughout the experiment. RTM was measured before and serially for 30 minutes after addition of amiloride. Control RTM was 20.29 +/- 0.86 [OMEGA]H cm2. These results indicate a rapid inhibitory effect of amiloride on the ionic permeability of parietal human peritoneum. The increase in the RTM observed after addition of amiloride clearly indicates the existence of amiloride-sensitive sodium channels on the human parietal peritoneal membrane, which may play some role in the ultrafiltration process and sodium removal during PD.

Enhancement of the transmesothelial resistance of the parietal sheep peritoneum by epinephrine in vitro: ussing-type chamber experiments.

The peritoneal mesothelium constitutes an ion transport barrier that is taken advantage of in peritoneal dialysis. The aim of this study was to investigate the effects of epinephrine on the electrical transmesothelial resistance (R(TM)) of the isolated parietal sheep peritoneum by means of Ussing-type chamber experiments. Intact parietal (diaphragmatic) peritoneal samples were obtained from adult sheep immediately after sacrifice and transferred within 0.5 h to the laboratory in a cooled Krebs-Ringer bicarbonate solution (4 degrees C, pH 7.5), bubbled with 95% O2-5% CO2. A parietal peritoneal planar sheet was mounted in a Ussing-type chamber. Epinephrine (10(-7) M) was added to the apical and the basolateral side. The R(TM) was measured before and serially after the addition of epinephrine for 30 min. As active ion transport is temperature-dependent, all measurements were performed at 37 degrees C. The results were calculated as means with standard errors (x +/- SE) of six independent experiments. The control R(TM) was 20.05 +/- 0.61 ohm x cm2. The addition of epinephrine to the basolateral side within 1 min induced an increase of R(TM) to 21.8 +/- 0.45 ohm x cm2, which decreased thereafter progressively to reach control values again after 15 min. A similar effect of epinephrine on the apical side was apparent with a rapid rise of R(TM) to 22.5 +/- 0.66 ohm x cm2 and a subsequent decrease (P < 0.05). A clear association between the R(TM) and active ion transport was established from previous studies. The results of our study indicate a rapid action of epinephrine on the parietal peritoneum permeability.

Endothelin-1 plasma levels in hemodialysis treatment--the influence of type 2 diabetes.

In patients on chronic hemodialysis the prevalence of atherosclerosis is increased and is by far the leading cause of morbidity and mortality. Endothelin-1, an endothelium-derived peptide with vasoconstrictive and mitogenic effects on vascular smooth muscles, is involved in the pathogenesis of atherosclerosis. The aim of the present study was to investigate the time course of plasma endothelin-1 levels during a hemodialysis session and to explore the influence of preexisting type 2 diabetes mellitus. Forty-five clinically stable hemodialysis patients (21 females, 24 males; mean age 62 +/- 12 years) were evaluated. Patients with type 2 diabetes (n= 11) were compared with the group of patients without diabetes (n=34). Relative blood volume (BV) changes (hemoglobinometry) and blood pressure (BP) was measured. Samples were taken before, every hour during, and after hemodialysis. Plasma endothelin-1 levels were measured by enzyme-linked immunoassay (ELISA) and results were corrected according to hemoconcentration. Hemodialysis with an ultrafiltration of 2215 +/- 952 mL was performed. Total BV at the end of hemodialysis was 89.3% +/- 8.3% of the pretreatment volume. Plasma endothelin-1 was enhanced in hemodialysis patients compared to normal subjects and increased from 1.28 +/- 0.47 before to 1.44 +/- 0.54 pg/mL (ref. 0.3-0.9) at the end of hemodialysis (p<0.05). The BV change (r=0.41) and the BP (mean BP: r=0.34) correlated with plasma endothelin-1 at the end of hemodialysis (p<0.05). The levels of endothelin-1 were significantly higher in the group of dialysis patients with type 2 diabetes compared to nondiabetics in all measurements (p<0.05). These findings suggest a potential role of endothelin-1 in the pathogenesis of vascular dysfunction in diabetes mellitus. The dialysis procedure per se, through vasoconstriction due to BV decrease, local endothelial injury (a.v. fistula), or bioincompatibility reactions (foreign surface contact) may additionally alter endothelial cell functions.