Neutrophil gelatinase-associated lipocalin is a biomarker of acute-on-chronic liver failure and prognosis in cirrhosis.

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in cirrhosis characterized by organ failure(s) and high mortality rate. There are no biomarkers of ACLF. The LCN2 gene and its product, neutrophil gelatinase-associated lipocalin (NGAL), are upregulated in experimental models of liver injury and cultured hepatocytes as a result of injury by toxins or proinflammatory cytokines, particularly Interleukin-6. The aim of this study was to investigate whether NGAL could be a biomarker of ACLF and whether LCN2 gene may be upregulated in the liver in ACLF. METHODS: We analyzed urine and plasma NGAL levels in 716 patients hospitalized for complications of cirrhosis, 148 with ACLF. LCN2 expression was assessed in liver biopsies from 29 additional patients with decompensated cirrhosis with and without ACLF. RESULTS: Urine NGAL was markedly increased in ACLF vs. no ACLF patients (108(35-400) vs. 29(12-73)µg/g creatinine; p<0.001) and was an independent predictive factor of ACLF; the independent association persisted after adjustment for kidney function or exclusion of variables present in ACLF definition. Urine NGAL was also an independent predictive factor of 28day transplant-free mortality together with MELD score and leukocyte count (AUROC 0.88(0.83-0.92)). Urine NGAL improved significantly the accuracy of MELD in predicting prognosis. The LCN2 gene was markedly upregulated in the liver of patients with ACLF. Gene expression correlated directly with serum bilirubin and INR (r=0.79; p<0.001 and r=0.67; p<0.001), MELD (r=0.68; p<0.001) and Interleukin-6 (r=0.65; p<0.001). CONCLUSIONS: NGAL is a biomarker of ACLF and prognosis and correlates with liver failure and systemic inflammation. There is remarkable overexpression of LCN2 gene in the liver in ACLF syndrome. LAY SUMMARY: Urine NGAL is a biomarker of acute-on-chronic liver failure (ACLF). NGAL is a protein that may be expressed in several tissues in response to injury. The protein is filtered by the kidneys due to its small size and can be measured in the urine. Ariza, Graupera and colleagues found in a series of 716 patients with cirrhosis that urine NGAL was markedly increased in patients with ACLF and correlated with prognosis. Moreover, gene coding NGAL was markedly overexpressed in the liver tissue in ACLF.

Early non-invasive selection of patients at high risk of severe hepatitis C recurrence after liver transplantation.

BACKGROUND: The early identification of patients at high risk of severe post liver transplant hepatitis C recurrence is relevant, as these patients may be treated using interferon (IFN)-free regimens. METHODS: In a retrospective study with prospectively collected data, we investigated whether the use of several non-invasive methods (fibrosis 4 index [FIB-4], AST-to-platelets ratio index [APRI], enhanced liver fibrosis test [ELF], IFN-γ-inducible protein 10 [IP-10], and transient elastography by Fibroscan) and their combinations 6 months after transplantation could identify those recipients at higher risk of severe recurrence, defined by the presence of significant fibrosis (F ≥2) and/or portal hypertension (hepatic venous pressure gradient ≥6 mmHg) 12 months after transplant. Seventy-two hepatitis C virus (HCV)-infected liver transplant patients and 10 recipients in whom HCV was eradicated before transplantation were included in the study. RESULTS: The levels of all biomarkers were significantly higher in HCV-infected recipients than in controls. Among HCV recipients, levels of biomarkers were significantly higher in patients with severe recurrence. Although there were no statistically significant differences between biomarkers, APRI, ELF, and FIB-4 obtained the highest area under the ROC curve values. The combination of serum biomarkers with Fibroscan increased the negative and positive predictive values, although diagnostic accuracy of individual tests was not significantly improved. CONCLUSIONS: Patients at higher risk of severe HCV recurrence can be identified early, 6 months after transplantation, using readily available non-invasive methods.

Accuracy of immunoassay and mass spectrometry urinary free cortisol in the diagnosis of Cushing's syndrome.

PURPOSE: Urinary free cortisol (UFC) determination by highly specific methods as mass spectrometry instead of commercially available antibody-based immunoassays is increasingly recommended. However, clinical comparisons of both analytical approaches in the screening of Cushing's syndrome (CS) are not available. The aim of this study was to evaluate the diagnostic value of mass spectrometry versus immunoassay measurements of 24 h-UFC in the screening of CS. METHODS: Cross-sectional study of 33 histologically confirmed CS patients: 25 Cushing's disease, 5 adrenal CS and 3 ectopic CS; 92 non-CS patients; and 35 healthy controls. UFC by immunoassay (UFCxIA) and mass spectrometry (UFCxMS), urinary free cortisone (UFCo) and UFC:UFCo ratio were measured, together with creatinine-corrected values. Sensitivity, specificity, AUC and Landis and Koch concordance index were determined. RESULTS: AUC for UFCxIA and UFCxMS were 0.77 (CI 0.68-0.87) and 0.77 (CI 0.67-0.87) respectively, with a kappa coefficient 0.60 and strong Landis and Koch concordance index. The best calculated cutoff values were 359 nmol/24 h for UFCxIA (78 % sensitivity, 62 % specificity) and 258.1 nmol/24 h for UCFxMS (53 % sensitivity, 86 % specificity). The upper limit of UFCxIA and UCFxMS reference ranges were 344.7 and 169.5 nmol/24 h respectively. Sensitivity and specificity for CS diagnosis at these cutpoints were 84 and 56 % for UFCxIA and 81 and 54 % for UFCxMS. CONCLUSIONS: According to our data, both methods present a very similar diagnostic value. However, results suggest that lower cutoff points for mass spectrometry may be necessary in order to improve clinical sensitivity.

Harmonization service and global library of models to support country-driven global information on salt-affected soils.

Global distribution of salt-affected soils (SAS) has remained at about 1 billion hectares in the literature over the years despite changes in climate, sea levels, and land use patterns which influence the distribution. Lack of periodic update of input soil data, data gaps, and inconsistency are part of the reasons for constant SAS distribution in the literature. This paper proposes harmonization as a suitable alternative for managing inconsistent data and minimizing data gaps. It developed a new harmonization service for supporting country-driven global SAS information update. The service contains a global library of harmonization models for harmonizing inconsistent soil data. It also contains models for identifying gaps in SAS database and for showing global distribution where harmonization of available data is needed. The service can be used by countries to develop national SAS information and update global SAS distribution. Its data availability index is useful in identifying countries without SAS data in the global database, which is a convenient way to identify countries to mobilize when updating global SAS information. Its application in 27 countries showed that the countries have more SAS data than they currently share with the global databases and that most of their data require SAS harmonization.

Adenoviral dominant-negative soluble PDGFRß improves hepatic collagen, systemic hemodynamics, and portal pressure in fibrotic rats.

BACKGROUND & AIMS: Platelet-derived growth factor (PDGF) is the most potent stimulus for proliferation and migration of stellate cells. PDGF receptor ß (PDGFRß) expression is an important phenotypic change in myofibroblastic cells that mediates proliferation and chemotaxis. Here we analyzed the relationship between PDGFRß expression, hemodynamic deterioration, and fibrosis in CCl(4)-treated rats. Thereafter, we investigated the effects produced by an adenovirus encoding a dominant-negative soluble PDGFRß (sPDGFRß) on hemodynamic parameters, PDGFRß signaling pathway, and fibrosis. METHODS: Mean arterial pressure, portal pressure, PDGFRß mRNA expression, and hepatic collagen were assessed in 6 controls and 21 rats induced to hepatic fibrosis/cirrhosis. Next, 30 fibrotic rats were randomized into three groups receiving iv saline and an adenovirus encoding for sPDGFRß or ß-galactosidase. After 7days, mean arterial pressure, portal pressure, serum sPDGFRß, and hepatic collagen were measured. RESULTS: CCl(4)-treated animals for 18weeks showed a significantly higher increase in PDGFRß mRNA compared to those treated for 13weeks and control rats. In CCl(4)-treated rats, the fibrous tissue area ranged from moderate to severe fibrosis. A direct relationship between the degree of fibrosis, hemodynamic changes, and PDGFRß expression was observed. Fibrotic rats transduced with the adenovirus encoding sPDGFRß showed increased mean arterial pressure, decreased portal pressure, lower activation of the PDGFRß signaling pathway, and reduced hepatic collagen than fibrotic rats receiving ß-galactosidase or saline. CONCLUSIONS: PDGFRß activation closely correlates with hemodynamic disorders and increased fibrosis in CCl(4)-treated rats. Adenoviral dominant negative soluble PDGFRß improved fibrosis. As a result, the hemodynamic abnormalities were ameliorated.

Inactivation of extrahepatic vascular Akt improves systemic hemodynamics and sodium excretion in cirrhotic rats.

BACKGROUND & AIMS: Increased activity of the vascular Akt/eNOS signaling pathway is involved in the hemodynamic and renal complications developed by patients and rats with cirrhosis and ascites. This occurs in the setting of impaired Akt/eNOS activity within the cirrhotic liver. Here we assessed the feasibility of selectively inhibiting vascular eNOS without further impairing the intrahepatic activity of this enzyme. Ultimately, we sought to determine whether endothelial transduction of a constitutively inactive mutant of Akt (AA-Akt) improves circulatory function and sodium excretion in cirrhotic rats with ascites. METHODS: First, we administered recombinant adenoviruses that encode the ß-galactosidase gene (ß-gal) to 5 control rats and 5 cirrhotic rats with ascites and analyzed their tissue distribution by chemiluminescence. Next, urine samples were obtained from 18 cirrhotic rats with ascites and then the animal randomly received saline or adenoviruses containing the ß-gal or the AA-Akt genes. Following a 24-h urine collection period, hemodynamic studies were performed and tissue samples were obtained to analyze Akt and eNOS expressions. RESULTS: No ß-gal activity was detected in the liver of cirrhotic rats compared to that of controls. This was paralleled by increased ß-gal activity in other territories such as the thoracic aorta. AA-Akt transduction improved systemic hemodynamics, splanchnic perfusion pressure and renal excretory function in comparison with cirrhotic rats transduced with ß-gal adenoviruses or receiving saline. Moreover, the AA-Akt transgene did not modify portal pressure. CONCLUSIONS: Inactivation of extrahepatic vascular Akt and the concomitant decrease in nitric oxide expression ameliorate systemic hemodynamics and renal excretory function in experimental cirrhosis.

Sentinel lymph node biopsy vs. pelvic lymphadenectomy in early stage cervical cancer: is it time to change the gold standard?

OBJECTIVE: To compare the incidence of pelvic lymph node metastases in early stage cervical cancer patients undergoing sentinel lymph node biopsy (SLN) to a matched cohort undergoing pelvic lymphadenectomy. METHODS: All patient data were entered prospectively into an ongoing cervical cancer database. Since April 2004, 87 patients with FIGO stage IA/B1 cervical cancer underwent SLN detection with identification of bilateral SLN. This cohort (cases) was compared to a matched group of patients who underwent complete pelvic lymphadenectomy (controls). The groups were matched 3:1 for tumour size (+/-5 mm), histology, depth of invasion (+/-2 mm), and presence of capillary lymphatic space invasion (CLS). Descriptive statistics were calculated for all variables of interest. The association between cases and controls and lymph node metastases was carried out using a conditional logistic regression analysis. RESULTS: 81 women in the SLN cohort were matched with 1 control, 72 cases with 2 controls, and 65 cases with 3 controls. Among cases, 14 (17%) had pelvic lymph nodes metastases vs. 15 (7%) in the controls (p=0.0059, odds ratio= 2.8, 95% CI=1.3-5.9). Among the 14 cases of SLN metastases, 11 were detected by frozen section and 3 were detected on final paraffin sectioning. All were detected by H and E stains. The size of the SLN metastases ranged from less than 1 mm to 8 mm. CONCLUSIONS: Sentinel lymph node biopsy in early cervical cancer is a more sensitive procedure in detecting pelvic lymph node metastases compared to complete lymphadenectomy.

Vascular endothelial growth factor and angiopoietin-2 play a major role in the pathogenesis of vascular leakage in cirrhotic rats.

BACKGROUND AND AIMS: The extent and molecular mechanisms governing plasma extravasation and formation of ascites in cirrhosis are unknown. Vascular endothelial growth factor-A (VEGF-A) and angiopoietin-2 (Ang-2) are endogenous substances with powerful vascular permeability effects. We assessed regional blood flow, vascular leakage, mRNA and tissular expression of VEGF-A and Ang-2 and vascular permeability following VEGF receptor 2 blockade in control and cirrhotic rats to define the vascular territories showing altered vascular permeability in cirrhosis and to determine whether VEGF-A and Ang-2 are involved in this phenomenon. METHODS: Arterial blood flow was analysed with the coloured microsphere method. Vascular leakage was measured and visualised with the dye Evan's Blue and colloidal carbon techniques, respectively. VEGF-A and Ang-2 expression were determined by real-time polymerase chain reaction (RT-PCR), immunohistochemistry and western blot. The effect on vascular permeability induced by VEGFR(2) blockade was assessed by administration of the receptor inhibitor SU11248. RESULTS: Arterial blood flow was increased in the mesentery, pancreas and small intestine but not in the kidney and spleen of cirrhotic rats as compared to controls. Increased vascular leakage was observed in the mesentery and liver, where colloidal carbon spread from microvessels to the adjacent fibrotic tracts. Increased hepatic and mesenteric expression of VEGF-A and Ang-2 was found in cirrhotic rats as compared to controls. Blockade of VEGFR(2) markedly reduced hepatic and mesenteric vascular leakage in cirrhotic rats. CONCLUSIONS: Enhanced endothelial permeability is restricted to the hepatic and mesenteric vascular beds in cirrhotic rats with ascites and VEGF-A and Ang-2 are key factors in the signalling pathways regulating this dysfunction.

Chronic hypotension in hemodialysis patients: role of functional vascular changes and vasodilator agents.

AIMS: The aim of this study was to evaluate the hemodynamic pattern, vascular compliance, as well as the levels of vasoregulatory hormones and markers of inflammation and oxidative stress in a group of chronic hypotensive (CH) patients undergoing hemodialysis (HD) and to compare them with a group of normotensive HD patients. MATERIAL AND METHODS: 14 normotensive and 10 CH hemodialysis patients were included in the study. Hemodynamic characteristics were evaluated by means of the pulse waveform analysis. Plasma levels of nitrites, interleukin-6 (IL-6), malondialdehyde (MDA), PTH-related peptide (PTHrp), catecholamines, angiotensin II and endothelin were measured. RESULTS: Blood pressure (BP) and peripheral vascular resistances (PVR) were lower in the hypotensive group (p < 0.001 and p = 0.005, respectively), whereas cardiac output was similar in both groups. Large (C1) (p = 0.001) and small (C2) (p = 0.022) artery elasticity indices were higher in hypotensive patients. In the whole group, C1 and C2 inversely correlated with mean BP (MBP). Plasma levels of nitrites (p = 0.011) were higher in hypotensive patients and inversely correlated with MBP (r = -0.516, p = 0.012). Time on HD correlated with plasma nitrites (r = 0.478, p = 0.024) and inversely with MBP (r = -0.598, p = 0.003). CONCLUSIONS: CH in HD patients is characterized by decreased PVR, a preserved cardiac output and greater vascular compliance. CH is associated with longer time on HD and higher plasma levels of nitrites/nitrates, suggesting that an enhanced production of nitric oxide induced by long-term HD, could be involved in CH. These findings suggest that functional vascular changes, likely related to an enhanced production of vasodilator agents, are responsible for CH in HD patients.

Differential Cell Composition and Cytokine Expression Within Lymph Node Granulomas from BCG-Vaccinated and Non-vaccinated Cattle Experimentally Infected with Mycobacterium bovis.

Cattle vaccination against bovine tuberculosis (bTB) has been proposed as a supplementary method to help control the incidences of this disease. Bacillus Calmette-Guérin (BCG) is currently the only viable candidate vaccine for immunization of cattle against bTB, caused by Mycobacterium bovis (M. bovis). In an attempt to characterize the differences in the immune response following M. bovis infection between BCG-vaccinated and non-vaccinated animals, a combination of gross pathology, histopathology and immunohistochemical (IHC) analyses was used. BCG vaccination was found to significantly reduce the number of gross and microscopic lesions present within the lungs and lymph nodes. Additionally, the microscopically visible bacterial load of stages III and IV granulomas was reduced. IHC using cell surface markers revealed the number of CD68+ (macrophages), CD3+ (T lymphocytes) and WC1+ cells (γδ T cells) to be significantly reduced in lymph node granulomas of BCG-vaccinated animals, when compared to non-vaccinated animals. B lymphocytes (CD79a+) were significantly increased in BCG-vaccinated cattle for granulomas at stages II, III and IV. IHC staining for iNOS showed a higher expression in granulomas from BCG-vaccinated animals compared to non-vaccinated animals for all stages, being statistically significant in stages I and IV. TGFß expression decreased alongside the granuloma development in non-vaccinated animals, whereas BCG-vaccinated animals showed a slight increase alongside lesion progression. IHC analysis of the cytokines IFN-γ and TNF-α demonstrated significantly increased expression within the lymph node granulomas of BCG-vaccinated cattle. This is suggestive of a protective role for IFN-γ and TNF-α in response to M. bovis infection. Findings shown in this study suggest that the use of BCG vaccine can reduce the number and severity of lesions, induce a different phenotypic response and increase the local expression of key cytokines related to protection.

CytoregR inhibits growth and proliferation of human adenocarcinoma cells via induction of apoptosis.

BACKGROUND: Cancer is one of the devastating neovascular diseases that incapacitate so many people the world over. Recent reports from the National Cancer Institute indicate some significant gain therapy and cancer management as seen in the increase in the 5-year survival rate over the past two decades. Although near-perfect cure rate have been reported in the early-stage disease, these data reveal high recurrence rate and serious side effects including second malignancies and fatalities. Most of the currently used anticancer agents are only effective against proliferating cancer cells. Thus attention has been focused on potential anti-cancer agents capable of killing cancer cells independent of the cell cycle state, to ensure effective elimination of most cancer cells. The objective of this study was to test the chemosensitivity and potential mechanism of action of a novel cancer drug, CytoregR, in a panel of human cancer cells. METHODS: the study was performed using a series of bioassays including Trypan blue exclusion, MTS Growth inhibition, LDH-cytotoxicity, TUNEL-Terminal DNA fragmentation Apoptosis Assay, and the Caspase protease CPP32 activity assays. RESULTS: CytoregR induced significant dose- and time-dependent inhibition of growth in all the cells; with significant differences in chemosensitivity (P < 0.05) between the target cells becoming more apparent at 48 hr exposure. CytoregR showed no significant effect on normal cells relative to the tumor cells. Growth inhibition in all the cells was due to induction of apoptosis at lower concentrations of cytoregR (> 1:300). CytoregR-induced caspase protease-3 (CPP32) activation significantly and positively correlated with apoptosis induction and growth inhibition; thus implicating CPP32 as the principal death pathway in cytoregR-induced apoptosis. CONCLUSION: CytoregR exerted a dose-and time-dependent growth inhibitory effect in all the target cells through induction of apoptosis via the CPP32 death pathway, independent of hormonal sensitivity of the cells. The present data indicate that not only could CPP32 provide a potential target for regulation of cytoregR-induced apoptosis but also that cytoregR could play a significant role in chemotherapeutic regimen in many human malignant tumors.

Non-tuberculous mycobacteria in wild boar (Sus scrofa) from Southern Spain: epidemiological, clinical and diagnostic concerns.

Non-tuberculous mycobacteria (NTM) are widely distributed in the environment, particularly in wet soil, marshland, rivers or streams, but also are causative agents of a wide variety of infections in animals and humans. Little information is available regarding the NTM prevalence in wildlife and their effects or significance in the bovine tuberculosis (bTB) epidemiology and diagnosis. This research shows the most frequently NTM isolated in lymph nodes of wild boar (Sus scrofa) from southern Spain, relating the NTM presence with the individual characteristics, the management of animals and the possible misdiagnosis of Mycobacterium bovis in concurrent infections. A total of 219 NTM isolates were obtained from 1249 wild boar mandibular lymph nodes sampled between 2007 and 2011. All but 75 isolates were identified by the PCR-restriction analysis-hsp65, and a partial sequencing of the 16S rDNA was carried out to identify the rest of the isolates. Results showed that Mycobacterium chelonae was the most frequently isolated NTM specie (133 isolates, 60.7%), followed by Mycobacterium avium (24 isolates, 11%). No relation was found regarding sex, body condition and management, but M. chelonae was more frequently detected in adults, whereas M. avium was more prevalent in subadults. The high NTM prevalence observed in the studied wild boar populations could make difficult the bTB diagnostic.

Circulatory dysfunction in asymptomatic in vitro fertilization patients. Relationship with hyperestrogenemia and activity of endogenous vasodilators.

Severe ovarian hyperstimulation syndrome (OHSS) is consistently associated with a circulatory dysfunction characterized by arterial hypotension, low peripheral vascular resistance, and increased activity of the renin-aldosterone system. To investigate whether circulatory dysfunction also occurs in asymptomatic patients undergoing controlled gonadotropin ovarian hyperstimulation under pituitary suppression for in vitro fertilization (IVF), 12 women without clinical manifestations of OHSS underwent sequential blood, urine, and hemodynamic measurements at five study points: the 7th day of the menstrual cycle preceding IVF (study point 1 or baseline), the day when pituitary suppression was shown (study point 2), the day of hCG ovulatory injection (study point 3), the day after hCG was injected (study point 4), and 7 days after hCG administration (study point 5). Mean arterial pressure, cardiac output, peripheral vascular resistance, plasma concentrations of estradiol (E2) and aldosterone, and plasma renin activity (PRA) were measured at each study point in all women. Serum levels of nitrite/nitrate, and plasma concentration of atrial natriuretic peptide, norepinephrine, adrenomedullin, and cyclic guanosine 3'5'-monophosphate were measured in samples obtained at study points 1 and 5. Multiple follicular development during ovarian stimulation associated with increased plasma E2 concentration (mean peak plasma E2 level, 2430 +/- 428 pg/mL, range 1630-3840 pg/mL) were observed in each woman. All patients developed a significant increase in cardiac output and decrease in arterial pressure and peripheral vascular resistance, and a marked elevation in PRA and aldosterone, all indicating the development of arteriolar vasodilation. Changes in circulatory measurements were temporarily related with the increase in E2 both being detected at study points 3-5. In contrast, there was a clear chronological dissociation between the increase in plasma E2 concentration and the stimulation of the renin-aldosterone system. PRA and aldosterone only reached abnormal levels at study point 5 in association with a significant increase in plasma norepinephrine concentration. Serum levels of nitrite/nitrate and plasma concentrations of atrial natriuretic peptide, adrenomedullin, and cyclic GMP were similar at study points 1 and 5. It is concluded that the circulatory dysfunction that characterizes severe OHSS is a universal event in patients undergoing controlled ovarian hyperstimulation for IVF. Although the increase in E2 levels during IVF cycles is associated with significant circulatory changes, the circulatory dysfunction that characterizes severe OHSS is clearly unrelated to the onset of hyperestrogenemia. Arteriolar vasodilation during IVF cycles was not associated with an increased activity of the vasodilator substances atrial natriuretic peptide, adrenomedullin, and nitric oxide.

Spatial discrimination is abnormal in focal hand dystonia.

BACKGROUND: In patients with focal hand dystonia, abnormal digit representations in the primary somatosensory cortex (S1) could be the result of enlarged and overlapping receptor fields, as suggested by an animal model of dystonia. A possible clinical correlate of this S1 abnormality is a disturbed spatial discrimination capability. OBJECTIVE: To test the hypothesis that somatosensory spatial discrimination is abnormal in focal hand dystonia. METHODS: Seventeen patients with focal hand dystonia underwent a quantitative evaluation of somatosensory spatial frequency (gap detection, JVP domes, applied to the distal phalanx of the index finger) and single-touch localization (Von Frey monofilaments, applied to the middle phalanx of the index finger). RESULTS: Compared with control subjects, patients had a decreased performance in both the gap detection (p = 0.004) and the localization (p = 0.013) tasks. The extent of spatial frequency abnormality correlated with age in both groups. CONCLUSIONS: These findings, together with a previously shown temporal discrimination deficit, support a role for sensory dysfunction in the pathophysiology of dystonia.

Periodic limb movements in sleep: state-dependent excitability of the spinal flexor reflex.

OBJECTIVE: To test the hypothesis that periodic limb movements (PLMs) are related to spinal flexor reflexes (FRs), the authors compared the state-dependent changes in FR excitability in 10 patients with restless legs syndrome (RLS) and PLMs with those from matched controls. BACKGROUND: PLM is a disorder of motor control during sleep, frequently occurring in RLS. Clinically, PLMs resemble spinal FRs. METHODS: FRs were obtained by electrically stimulating the medial plantar nerve and recording from antagonist leg and thigh muscles bilaterally. RESULTS: Compared with controls, patients had significantly increased spinal cord excitability, as indicated by lower threshold and greater spatial spread of the FR, which was more prominent during sleep. Multiple late responses were seen during sleep in all patients and in some controls at higher threshold. The most prominent of these responses had a very long duration and a latency range of 250 to 800 msec, and because of its close temporal relationship to the FR stimulus, the authors considered it was a late, high-threshold component of the FR (FR3). The authors also found a similarity between the pattern of muscle recruitment and spatial spread of late components of the FR and those of spontaneous PLMs. CONCLUSIONS: The results support the hypothesis that PLMs in RLS and FRs share common spinal mechanisms and suggest that PLMs may result from enhanced spinal cord excitability in RLS patients. Because dopaminergic mechanisms are involved in spinal FR control, the results are consistent with the current view that RLS is a disorder of dopaminergic function.

Impaired response of atrial natriuretic factor to blood volume expansion in acute right ventricular infarction.

To assess the role of atrial natriuretic factor (ANF) in right ventricular (RV) infarction, 30 patients with inferior wall acute myocardial infarction (15 with RV involvement) and normal left heart filling pressures were studied 39 +/- 12 hours after the onset of symptoms. Serial measurements of cardiac output, right atrial, pulmonary artery and pulmonary wedge pressures, as well as plasma ANF, plasma renin activity, plasma aldosterone and vasopressin were obtained before and 30 minutes after acute volume expansion to raise wedge pressure greater than or equal to 20 mm Hg. Baseline mean right atrial pressure and plasma ANF levels were greater in patients with than without RV infarction (8 +/- 3 vs 5 +/- 2 mm Hg; p less than 0.0001, and 4.6 +/- 2.9 vs 2.7 +/- 1.5 fmol/ml; p less than 0.05, respectively). There were no differences in other baseline hemodynamic or humoral parameters between both groups. After volume expansion, pulmonary wedge pressure was similar in both groups, but right atrial pressure increased to higher levels in patients with RV infarction (19 +/- 2 vs 14 +/- 2 mm Hg; p less than 0.0001). Despite this greater stimulus for ANF secretion, the increase in plasma ANF was less pronounced in patients with RV infarction (63 +/- 81 vs 455 +/- 417%; p less than 0.002), especially among those with paroxysmal supraventricular tachyarrhythmias. Thus, despite higher baseline plasma levels of ANF, response to volume loading is markedly attenuated in patients with RV infarction complicating an inferior wall acute myocardial infarction.

Nitric oxide synthase II mRNA expression in cardiac tissue of patients with heart failure undergoing cardiac transplantation.

OBJECTIVES: To examine whether inducible nitric oxide synthase is expressed in myocardial tissue of patients with heart failure. BACKGROUND: There is increasing evidence that alterations in nitric oxide synthesis are of pathophysiologic importance in heart failure. Nitric oxide (NO) can exert negative inotropic and cytotoxic effects on cardiomyocytes. A number of studies have shown altered nitric oxide production by the endothelial constitutive isoform of nitric oxide synthase (NOS III), but there is little information on the role of NOS II. Expression of NOS II could lead to excessive production of NO in the myocardium and affect cardiac contractility. METHODS: NOS II mRNA expression in myocardial tissue of 18 patients with idiopathic dilated cardiomyopathy (DCM), 7 patients with ischemic cardiopathy and severe ventricular dysfunction (ISCH), 4 patients with acute myocardial infarction (AMI) and 11 controls. Serum concentration of NO2-/NO3- (NOx) was also measured. RESULTS: NOS II gene expression occurred in all the patients with DCM, in 1 out of the 7 ISCH patients, in 2 out of the 4 patients with AMI and in none of the controls. Moreover, DCM patients showed a significant 6-fold increase in NOx concentration (253+/-47 nm/ml) as compared to controls (40+/-2 nm/ml) P < 0.001, a phenomenon not observed in ISCH patients (56+/-3 nm/ml). CONCLUSIONS: NOS II expression occurs in failing human cardiac myocytes and can play an specific role in the pathogenesis of DCM.

Effect of antihypertensive treatment on the increased beta 2-adrenoceptor density in patients with essential hypertension.

The effect of different antihypertensive drugs on the increased surface beta 2-adrenoceptor density in essential hypertension was evaluated to elucidate whether the possible effect of the treatment on these receptors was secondary to blood pressure decreases or a specific effect of the drugs. Thirty-nine untreated essential hypertensive patients and 28 normotensive control subjects were studied in basal conditions. Hypertensive patients were randomly assigned to three treatment groups: bisoprolol (10 mg/day, n = 15), enalapril (20 mg/day, n = 12), and verapamil SR (240 mg/day, n = 12), and were studied before and after 1 month of treatment. Plasma catecholamines were determined by a radioenzymatic assay. Surface beta 2-adrenoceptors were measured in intact lymphocytes by radioligand binding assay using the hydrophilic ligand [3H]-CGP12177. beta 2-adrenoceptor density was increased in hypertensive patients (P < .01). After treatment, mean blood pressure decreased similarly in the three groups, while plasma catecholamines showed no significant changes in any group. beta 2-adrenoceptor number decreased only in bisoprolol-treated patients (P < .05). Mean blood pressure decreases correlated with beta 2-adrenoceptor decrements only in bisoprolol-treated patients (r = 0.65, P < .05). beta 2-adrenoceptor density correlated with plasma epinephrine levels in the control group (r = -0.50, P < .01), but not in hypertensive patients before treatment. This correlation was also observed in hypertensive patients treated with bisoprolol (r = -0.52, P < .05), but not in those treated with verapamil or enalapril. Our results suggest that bisoprolol treatment reduces the increased surface beta 2-adrenoceptor density and restores its regulation by epinephrine in essential hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)