Levels of l-arginine and l-citrulline in patients with erectile dysfunction of different etiology.

Nitric oxide is a physiologic signal essential to penile erection. l-citrulline (l-Cit) is converted into l-arginine (l-Arg), the precursor from which nitric oxide is generated. The level of l-Arg and l-Cit in the field of male sexual function remains relatively underexplored. The aim of the study was to evaluate the level of serum l-Arg and of l-Cit in a group of patients with erectile dysfunction. Diagnosis and severity of erectile dysfunction was based on the IIEF-5 and its etiology was classified as arteriogenic (A-ED), borderline (BL-ED), and non-arteriogenic (NA-ED) with penile echo-color-Doppler in basal condition and after intracaversous injection of prostaglandin E1. Serum l-Arg and l-Cit concentrations were measured by a cation-exchange chromatography system. l-Arg and l-Cit levels of men with A-ED were compared with those of male with BL-ED and NA-ED. Median level of l-Arg and l-Cit in 122 erectile dysfunction patients (41 A-ED, 23 ED-BL, 58 NA-ED) was 82.7 and 35.4 µmol/L, respectively. l-Arg and l-Cit levels in control patients were not significantly different (p = 0.233 and p = 0.561, respectively) than in total erectile dysfunction patients. l-Arg and l-Cit levels in control patients were significantly higher (p < 0.001 and p < 0.018, respectively) than in A-ED patients, but no difference (p > 0.50) was observed in controls and in both BL-ED and NA-ED patients. Patients with severe/complete-erectile dysfunction (IIEF-5 < 10) had l-Arg or l-Cit level significantly lower (-17%, p < 0.03; -13%, p < 0.04) and were more frequent (p < 0.01 and p < 0.04) under the respective median level (82.7 and 35.4 µmol/L) than those with mild-erectile dysfunction (IIEF-5 = 16-20). l-Arg and l-Cit levels in A-ED were significantly lower (p < 0.007 and p < 0.001, respectively) than in NA-ED patients. Penile echo-color-Doppler revealed that A-ED (peak systolic velocity ≤ 25 cm/sec) was more frequent in men with l-Arg under 82.7 µmol/L or l-Cit under 35.4 µmol/L and in the same population, the median peak systolic velocity values were lower in l-Arg deficient (29 vs. 35; p < 0.04) and also in l-Cit deficient (31 vs. 33, p > 0.3) but without reaching the statistical significance. Our study shows that a significant proportion of erectile dysfunction patients have low l-Arg or l-Cit level and that this condition is more frequent in patients with arteriogenic etiology. Low levels of these nitric oxide synthase substrates might increase the erectile dysfunction risk by reducing the concentration of nitric oxide.

A pilot observational study on magnesium and calcium imbalance in elderly patients with acute aortic dissection.

BACKGROUND: Magnesium (Mg) and calcium (Ca) are the principal essential elements involved in endothelial cell homeostasis. Extracellular changes in the levels of either alter endothelial contraction and dilatation. Consequently Mg and Ca imbalance is associated with a high risk of endothelial dysfunction, the main process observed during acute aortic dissection (AAD); in this clinical condition, which mainly affects elderly men, smooth muscle cell alterations lead to intimal tears, creating a false new lumen in the media of the aorta. AAD patients have a high risk of mortality as a result of late diagnosis because often it is not distinguished from other cardiovascular diseases. We investigated Mg and Ca total circulating levels and the associated pro-inflammatory mediators in elderly AAD patients, to gain further information on the pathophysiology of this disorder, with a view to suggesting newer and earlier potential biomarkers of AAD. RESULTS: Total circulating Mg and Ca levels were both lower in AAD patients than controls (p < 0.0001). Using Ca as cut-off, 90% of AAD patients with low Ca (<8.4 mg/dL) came into the type A classification of AAD. Stratifying AAD according to this cut-off, Mg was lower in patients with lower total Ca. Compared to controls, both type A and B AAD patients had higher levels of all the pro-coagulant and pro-inflammatory mediators analyzed, including sP-sel, D-dimer, TNF-α, IL-6, and CRP (p < 0.05). Dividing types A and B using the Stanford classification, no significant differences were found (p > 0.05) The levels of both ICAM-1 and EN-1 were lower in AAD than in a control group (p < 0.0001 and p < 0.05 respectively). CONCLUSIONS: These findings suggest that low Mg and Ca in AAD elderly patients may contribute to altering normal endothelial physiology and also concur in changing the normal concentrations of different mediators involved in vasodilatation and constriction, associated with AAD onset and severity.

Epicardial adipose tissue inflammation is related to vitamin D deficiency in patients affected by coronary artery disease.

BACKGROUND AND AIMS: Alterations in epicardial adipose tissue (EAT) biology (i.e. increased fat thickness and inflammation) have been described in coronary artery disease (CAD) patients. In addition to its classic role in the regulation of calcium-phosphate homeostasis, vitamin D may exert immune-regulatory and anti-inflammatory effects. Whether EAT inflammation may be linked to vitamin D deficiency is still unknown. In the present study we evaluated plasma 25-hydroxycholecalciferol (25OHD) level in CAD patients and its relationship with EAT ability to locally metabolize vitamin D, EAT expression of inflammation-related molecules and EAT thickness. METHODS AND RESULTS: Plasma 25OHD level was quantified by an immunoluminometric assay. EAT expression of inflammation-related molecules (MCP-1, PTX3, TNFα, IL-6, adiponectin), vitamin D receptor (VDR), CYP27B1 (25OHD-activating enzyme) and CYP24A1 (1,25-dihydroxycholecalciferol-metabolizing enzyme) was performed by microarray. EAT thickness was quantified by echocardiography. Median plasma 25OHD level was 10.85 ng/mL and 83% of CAD patients displayed 25OHD level below 20 ng/mL. At decreasing plasma 25OHD concentration, we observed a down-regulation in CYP27B1 and CYP24A1 level and an increased expression of VDR and pro-inflammatory cytokines (MCP-1, PTX3, TNFα, IL-6) at EAT level. No correlation was observed between plasma 25OHD level and EAT thickness. CONCLUSION: Our data suggest an increased activation of inflammatory pathways at EAT level possibly related to systemic and local vitamin D deficiency in CAD patients. Whether maintaining an optimal vitamin D status may be helpful to reduce EAT inflammation and to prevent CAD and its progression needs further investigation.

Levels of human erythrocyte membrane-bound and cytosolic glycohydrolases are associated with oxidative stress in erectile dysfunction patients.

Oxidative stress (OS) and production of NO, by endothelium nitric oxide synthetase (eNOS), are involved in the pathophysiology of erectile dysfunction (ED). Moreover, OS induces modifications of the physicochemical properties of erythrocyte (RBC) plasma membranes and of the enzyme content of the same membranes. Due to their role in signalling early membrane alterations in OS-related pathologies, several plasma membrane and cytosolic glycohydrolases of human RBC have been proposed as new markers of cellular OS. In RBC, NOS can be activated and deactivated by phosphorylation/glycosylation. In this regulatory mechanism O-ß-N-AcetylGlucosaminidase is a key enzyme. Cellular levels of O-GlcNAcylated proteins are related to OS; consequently dysfunctional eNOS O-GlcNAcylation seems to have a crucial role in ED. To elucidate the possible association between RBC glycohydrolases and OS, plasma hydroperoxides and antioxidant total defenses (Lag-time), cytosolic O-ß-N-AcetylGlucosaminidase, cytosolic and membrane Hexosaminidase, membrane ß-D-Glucuronidase, and α-D-Glucosidase have been studied in 39 ED patients and 30 controls. In ED subjects hydroperoxides and plasma membrane glycohydrolases activities are significantly increased whereas Lag-time values and cytosolic glycohydrolases activities are significantly decreased. These data confirm the strong OS status in ED patients, the role of the studied glycohydrolases as early OS biomarker and suggest their possible use as specific marker of ED patients, particularly in those undergoing nutritional/pharmacological antioxidant therapy.

Performance assessment of a glucose control protocol in septic patients with an automated intermittent plasma glucose monitoring device.

BACKGROUND & AIMS: The optimal level and modality of glucose control in critically ill patients is still debated. A protocolized approach and the use of nearly-continuous technologies are recommended to manage hyperglycemia, hypoglycemia and glycemic variability. We recently proposed a pato-physiology-based glucose control protocol which takes into account patient glucose/carbohydrate intake and insulin resistance. Aim of the present investigation was to assess the performance of our protocol with an automated intermittent plasma glucose monitoring device (OptiScanner™ 5000). METHODS: OptiScanner™ was used in 6 septic patients, providing glucose measurement every 15' from a side-port of an indwelling central venous catheter. Target level of glucose was 80-150 mg/dL. Insulin infusion and kcal with nutritional support were also recorded. RESULTS: 6 septic patients were studied for 319 h (1277 measurements); 58 [45-65] hours for each patient (measurements/patient: 231 [172-265]). Blood glucose was at target for 93 [90-98]% of study time. Mean plasma glucose was 126 ± 11 mg/dL. Only 3 hypoglycemic episodes (78, 78, 69 mg/dL) were recorded. Glucose variability was limited: plasma glucose coefficient of variation was 11.7 ± 4.0% and plasma glucose standard deviation was 14.3 ± 5.5 mg/dL. CONCLUSIONS: The local glucose control protocol achieved satisfactory glucose control in septic patients along with a high degree of safeness. Automated intermittent plasma glucose monitoring seemed useful to assess the performance of the protocol.

Plasma myeloperoxidase in patients with erectile dysfunction of arteriogenic- and non-arteriogenic origin: association with markers of endothelial dysfunction.

Endothelial dysfunction and the disruption of the nitric oxide-cyclic guanosine monophosphate (cGMP) pathway have been considered the early mechanisms for the development of erectile dysfunction (ED). Myeloperoxidase (MPO), a heme-containing enzyme mainly released by activated neutrophils and monocytes, may contribute to endothelial dysfunction by promoting oxidation of different substrates and thus may play a role in ED. MPO level and its correlation with different plasma biomarkers of endothelial dysfunction were studied in patient with ED of arteriogenic (A-ED) and non-arteriogenic (NA-ED) to assess potential differences between the two ED subgroups. Diagnosis of ED was based on the International Index of Erectile Function Score. Its etiology was classified with penile echo-color Doppler at baseline and after intracavernous injection of prostaglandin E1. MPO, soluble (s) cGMP, sICAM-1, sVCAM-1 and sP-Selectin were measured by enzyme-linked immunosorbent assay. MPO concentration in A-ED was significantly higher compared to control subjects and NA-ED patients. Plasmatic cGMP level resulted lower both in A-ED and in NA-ED patients, whereas no difference has been observed between the two ED groups. sICAM-1 concentration resulted higher in A-ED compared both to controls and NA-ED. sVCAM-1 level was the same in controls, A-ED and NA-ED patients. sP-Selectin concentration resulted higher both in A-ED and in NA-ED patients than in controls, whereas no difference has been observed between the two ED groups. Correlation analysis indicated a positive correlation between plasmatic MPO, sICAM-1 and sP-Selectin levels. MPO may represent an important link between oxidation, inflammation and cardiovascular diseases and may also represent a potential marker to distinguish between the two subgroups of ED patients. Moreover, in ED subjects circulating cGMP may reflect the local signaling dysfunction. The use cGMP as a potential marker for monitoring the disease needs further investigation.

Early retinol-binding protein levels are associated with growth changes in infants born to diabetic mothers.

BACKGROUND: Biochemical predictors of infants' growth changes are not available. OBJECTIVES: We tested whether retinol-binding protein (RBP), docosahexaenoic acid and insulin (I) measured within 72 h from birth are associated with growth changes in infants born to mothers with gestational diabetes mellitus (GDM). METHODS: Fifty-six children, 32 born to diabetic mothers treated with insulin (GDM-I) and 24 born to diabetic mothers treated with diet (GDM-D), were evaluated at 0, 1, 3, 6 and 12 months of life. RESULTS: At multivariable regression performed using generalized estimating equations, early RBP levels and maternal body mass index were associated to average weight changes and early RBP and insulin levels to average length changes, respectively. There was no difference between GDM-I and GDM-D infants. CONCLUSIONS: This exploratory study suggests that early RBP levels may be a predictor of growth changes.

Time course of proadrenomedullin in the early phase of septic shock. A comparative study with other proinflammatory proteins.

AIM: It has been shown that pro-adrenomedullin is a good marker of the severity of septic shock but there are no data on the early changes in serum pro-adrenomedullin concentrations in patients with shock. METHODS: Twenty-one patients with septic shock and 21 healthy subjects studied as controls. Serum concentrations of pro-adrenomedullin, procalcitonin, ferritin, CRP and IL-6 were determined in all subjects at the initial observation. Patients with septic shock were also studied after 24 and 48 hours. RESULTS: The concentrations of the acute phase proteins were significantly higher in patients with septic shock than in the control subjects during the entire study period (P<0.001). Only procalcitonin significantly decreased on the third day of observation with respect to both the first day (P=0.002) and the second day (P=0.006). Proadrenomedullin (P=0.017) and IL-6 (P=0.001) showed an AUC significantly different from the null hypothesis in differentiating the patients who survived and those who did not. The sensitivity and specificity of pro-adrenomedullin in the assessment of death were 71.4% and 72.7%, respectively, while IL-6 had a sensitivity of 92.9% and a specificity of 60.6%. CONCLUSION: Proadrenomedullin is a reliable prognostic marker in patients with shock; further studies on a more consistent number of septic patients will definitively assess whether proadrenomedullin may replace the current prognostic markers in critically ill patients with shock due to sepsis.

Asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and L-arginine in patients with arteriogenic and non-arteriogenic erectile dysfunction.

The plasma concentration of asymmetrical dimethylarginine (ADMA), an inhibitor of nitric oxide synthase, has been linked to endothelial dysfunction. We investigated the relation between ADMA, symmetric dimethylarginine (SDMA) and L-arginine concentrations and erectile dysfunction. We compared plasma levels of ADMA, SDMA and L-arginine in 61 men in good health with erectile dysfunction of arteriogenic and non-arteriogenic origin. Diagnosis of erectile dysfunction was based on the International Index of Erectile Function Score and its aetiology was classified with penile echo-colour-Doppler in basal condition and after intracavernous injection of prostaglandin E1. The ADMA and SDMA concentrations were significantly higher in men with arteriogenic erectile dysfunction compared with those with erectile dysfunction of non-arteriogenic origin (p < 0.05) and the concentrations in both subgroups were significantly higher than in controls (p < 0.001). There was a negative correlation between ADMA and International Index of Erectile Function Score only in arteriogenic erectile dysfunction subgroup. L-arginine did not differ significantly neither between the two erectile dysfunction subgroups (p > 0.05) nor between each of the two erectile dysfunction subgroups and controls (p > 0.05). The L-arginine/ADMA and the L-arginine/SDMA ratios in arteriogenic erectile dysfunction subgroups were significantly lower than both in controls (p < 0.05) and in non-arteriogenic erectile dysfunction patients (p < 0.05); the two ratios in non-arteriogenic erectile dysfunction patients did not differ from those in the controls (p > 0.05). We conclude that ADMA and SDMA concentrations are significantly higher and L-arginine/ADMA ratio lower in patients who have arteriogenic erectile dysfunction compared with both patients with non-arteriogenic erectile dysfunction and controls. The negative correlation between ADMA and severity of erectile dysfunction is present only in patients with arteriogenic erectile dysfunction. This study supports the importance to always distinguish arteriogenic from non-arteriogenic erectile dysfunction patients to study the complicate erectogenic mechanisms that lead to erectile dysfunction and also to provide potential therapeutic agents for patients with arteriogenic erectile dysfunction.

IL-18 level in patients undergoing coronary artery bypass grafting surgery or valve replacement: which link with epicardial fat depot?

Interleukin-18 (IL-18) is a member of the interleukin-1 family of cytokines produced constitutively by different cell types and by adipose tissue. Due to the link between obesity, inflammation and cardiovascular diseases, we aimed to measure IL-18 circulating level in patients undergoing open-heart surgery both for elective coronary artery bypass grafting (CABG) or for valve replacement (VR), and we also evaluated whether epicardial adipose tissue (EAT) depot may be a potential source of IL-18. Circulating IL-18 protein was quantified by enzyme-linked immunosorbent assay. IL-18, IL-18 receptor 1 (IL-18 R1) and IL-18 receptor accessory protein (IL-18-RAP) gene expression in EAT depot were evaluated by one colour microarray platform. EAT thickness was measured by echocardiography. In this study we found that all cardiovascular patients (CABG and VR) have increased circulating IL-18 level compared to healthy control subjects (p < 0.0001), but no statistical significant difference was observed between CABG and VR groups (p = 0.35). A great increase in the gene expression of IL-18 (p < 0.05), IL-18 R1 (p < 0.01) and IL-18 RAP (p < 0.001) was observed in EAT samples obtained from CABG vs VR patients. In conclusion, CABG and VR patients had similar increased level of circulating IL-18 protein, but in EAT depots isolated from CABG gene expression of IL-18, IL-18 R1 and IL-18-RAP resulted higher than in VR patients. Future investigation on local IL-18 protein production, its autocrine-paracrine effect and its correlation with plasmatic IL-18 level could give more information on the relationship between IL-18 and coronary artery disease.

Effects of cold-water immersion and contrast-water therapy after training in young soccer players.

AIM: Recent studies have investigated the importance of recovery strategies after training session, including hydrotherapy and cryotherapy. However, only a few studies have focused on cold-water immersion (CWI) treatments in team sport disciplines. The present study investigates the effects of CWI and contrast-water therapy (CWT) on the performance of young male soccer players during a week of training. METHODS: Eighteen young soccer players participated in the present study (age 15.5±1.0 years, weight 61.8±3.0 Kg, height 175.5±4.0 cm and training experience 8.1±1.0 years). They were involved in a four-day study with recovery using CWI or with CWT after each training session by using performance tests and small-sided games. We measured uric acid concentration, leukocytes, haemoglobin, reticulocytes and creatine kinase changes in the blood, axillary temperature, rating of perceived exertion after a training session, heart rate during exercise, performance tests (counter movement jump, repeated sprint ability and 5' shuttle run). RESULTS: No significant difference were reported between groups when different physiological tests were used; CWI and CWT did not negatively influence the performances of the athletes. The principal effect of CWI was a reduced perception of fatigue after the training session. The use of active recovery protocols based on cold water or cold/thermoneutral water did not induce modifications of inflammatory and haematological markers in young soccer players. CONCLUSION: The beneficial effect of a reduced perception of fatigue can improve training and competitions in young soccer players.

Daily monitoring of biomarkers of sepsis in complicated long-term ICU-patients: can it support treatment decisions?

BACKGROUND: Diagnosis/grading of infection and the systemic response to infection may be difficult on admission to the intensive care unit, but it is even more complicated for severely ill patients with long intensive care stays. The ACCP-SCCM criteria are difficult to apply for such patients, and objective, validated biomarkers would be of great use in this setting. METHODS: Long-term (>6 days) critically ill patients in the general ICU of University Hospital were prospectively enrolled in the study. All patients were assessed daily by the attending physician using the ACCP-SCCM classification. C-reactive protein (CRP, mg/dL), procalcitonin (PCT, ng/mL), and interleukin-6 (IL-6, pg/mL) of daily stored sera were measured after each patient's discharge. After discharge, an independent, overall clinical evaluation and an a posteriori ACCP-SCCM classification were chosen as the reference standard for all comparisons. The assessor was aware of the patient's clinical course but was blinded to levels of biomarkers. RESULTS: We studied clinical variables and biomarkers of 26 patients over a total of 592 patient days. The day-by-day ACCP-SCCM classification of the attending physician overestimated the severity of the inflammatory response to infection. The diagnostic discriminative ability of severe-sepsis/septic-shock for PCT was high (ROC area 0.952 [0.931-0.973]) and had a best threshold value of 1.58 (83.7% sensitivity, 94.6 % specificity). IL-6 had better discriminative ability than CRP, but both were worse than PCT. CONCLUSION: PCT > 0.43 ng/mL could add to the clinical propensity for sepsis vs. SIRS not related to infection. Values higher than 1.58 ng/mL may support the bedside clinical diagnosis of severe-sepsis. PCT between 0.5 and 1.0 suggest tight daily monitoring of clinical conditions and re-evaluation of PCT.

Intra-operative testing for parathyroid hormone: the Central Laboratory option.

BACKGROUND: Intra-operative PTH testing in the operating theatre has proven to be an accurate way to verify the removal of all pathological parathyroid tissue in primary hyperparathyroidism. Its limitation is the high cost. An alternative, more cost-effective procedure is proposed: intra-operative PTH dosage at the Central Laboratory. PATIENTS AND METHODS: Fifty-four patients underwent parathyroidectomy with intraoperative dosage of PTH at the Central Laboratory. Three blood samples were taken from each patient: just after the induction of anesthesia, 5 and 10 min after parathyroidectomy. The samples were sent to the Central Laboratory and analysed simultaneously. The results were phoned back to the theatre. The procedure was considered effective when PTH drop was >/=50% from basal value, 10 min after parathyroidectomy. RESULTS: 98.1% of patients proved recovered (average follow- up 31.1 months). The procedure had 3 false negatives, 1 false positive, with sensitivity, specificity, accuracy, positive predictive value and negative predictive value of 94.0%, 75.0%, 92.6%, 97.9%, and 50.0%, respectively. DISCUSSION AND CONCLUSION: The main disadvantage of the presented procedure is the long waiting time. Nevertheless this time is the same as that required for results from intra-operative histological examination, the only alternative to determine surgery effectiveness in centres where portable instrumentation for intra-operative PTH dosage in the operating theatre is not available. The advantage of intra-operative PTH at the Central Laboratory is the very low cost. If results in terms of sensitivity, specificity, accuracy, and cost are taken into consideration, intra-operative dosage of PTH at the Central Laboratory may be deemed a viable alternative to the operating theatre.

Multiple sclerosis and celiac disease: is there an increased risk?

Multiple sclerosis and celiac disease are both considered immune-mediated diseases. Recently, improved serological screening methods provided a higher prevalence of celiac disease (CD) in the general population worldwide and also demonstrated gastrointestinal symptoms may be lacking. The aim of this study was to determine the prevalence of (CD) in an unselected group of 95 adults with multiple sclerosis using transglutaminase antibodies. No patients showed pathological values. Different immune and genetic basis between the two diseases may represent crucial insights to explain our results.

cAMP cascade leads to Ras activation in cortical neurons.

Monoaminergic G protein-coupled receptors (GPCRs) are highly expressed in the CNS at the cerebrocortical level, where they support a variety of behavioural responses. To elucidate possible intracellular signalling pathways coupled to these receptors, we have studied their ability to activate extracellular signal-regulated kinases (ERKs) in cultured cortical neurons. An increase in ERK activity was observed after stimulation of neurons with dopamine or serotonin, and with agonists selective for various GPCRs. In addition, ERK activation was also observed following treatment with phorbol dibutyrate (PdBu) and forskolin, activators of protein kinase C (PKC) and protein kinase A (PKA), respectively. Concomitant with ERK activation, all the monoaminergic agonists tested also increased the level of active Ras (Ras-GTP). Surprisingly, Ras activation was also observed after activation of cAMP pathway, and this effect was at least in part mediated by PKA. Ras activation by cAMP was unique for neurons, since in PC12 cells forskolin caused activation of ERK but did not increase Ras-GTP level. These results highlight the relevance of Ras as a target for multiple signalling cascades leading to activation of the ERK pathway in neurons.