Interpolación geoestadística de datos topográficos para obtener un MED de una pequeña cuenca forestal en el noroeste de España

[Abstract] This article gives an example of the elaboration of a digital elevation model (DEM) with the aid of geostatistics, using the case of a small experimental catchment near Arcos de la Condesa in Galicia, Spain. A DEM is a necessary tool in present-day erosion and landscape modelling. The geostatistical method of DEM construction involves six steps, starting with the removal of the drift and ending with the final interpolation. The drift was almost completely eliminated by a first order trend surface. After it had been confirmed that no heteroscedacity is present in the data set, the resulting experimental variogram was fitted by an anisotropic Gaussian variogram model, which is the variogram model that is generally used for DEM interpolation. Cross validation was used to determine the optimal number of data points to be used in interpolation. The interpolation results were found to be satisfactory and the interpolation standard deviations are below the data set standard deviation. It is yet noted that this uncertainty in the DEM – although small – may influence its derivatives and subsequent model results. However, when compared to other methods of DEM elaboration, the method as used here is an easy, adequate and relatively fast method, that has the major advantage of providing interpolation errors, enabling an evaluation of the interpolation result

Pulmonary functions in sewage workers

Background: Occupational lung diseases in sewage workers have not received sufficient attention, despite chronic exposure to noxious material. We aimed to describe the pulmonary function testing pattern of sewage workers with special emphasis on estimated lung age.Methods: We included sewage workers who came for health check-up. We excluded patients who had respiratory infection/any other respiratory ailments. Socio-demographic profile, history and examination were noted. Routine haematological investigations, chest radiograph, PFT were done. Basal and predicted measurements FVC, FEV1, PEFR, FE F25-75%, MVV and estimated lung age were noted.Results: Average age was 43.48±7.96 years on presentation and no one was symptomatic, everyone had normal X-ray chest findings. Of these 82 participants,36 had normal pattern on PFT. Out of 46 abnormal patterns, 28 had obstructive,5 restrictive and 13 had mixed patterns. In Obstructive pattern, mean FEV1/FVC ratio was 78.15 + 4.42 %, FEV1% was 89.26+10.27 %. In restrictive pattern, mean FVC % was 71%±5.72. In mixed pattern mean FVC % was 71.83+10.7%, FEV1 % was 70.98+6.43%.FEF (25-75%) was 62±10.85% in the obstructive pattern and 93±11.49% in the restrictive pattern. Estimated lung age was found to be 45±10.71 years, 55±11.36 years and 67±7.54 years in normal, obstructive and restrictive pattern which was high.Conclusions: There is a considerable burden of occupation lung diseases in the form of reduced lung functions among sewage workers, which often goes undiagnosed. Periodic assessment and appropriate measures in reducing the exposure should be considered

Statins: Old drugs as new therapy for liver diseases?

In addition to lowering cholesterol levels, statins have pleiotropic effects, particularly anti-inflammatory, antiangiogenic, and antifibrotic, that may be beneficial in some chronic inflammatory conditions. Statins have only recently been investigated as a potential treatment option in chronic liver diseases because of concerns related to their safety in patients with impaired liver function. A number of experimental studies in animal models of liver diseases have shown that statins decrease hepatic inflammation, fibrogenesis and portal pressure. In addition, retrospective cohort studies in large populations of patients with cirrhosis and pre-cirrhotic conditions have shown that treatment with statins, with the purpose of decreasing high cholesterol levels, was associated with a reduced risk of disease progression, hepatic decompensation, hepatocellular carcinoma development, and death. These beneficial effects persisted after adjustment for disease severity and other potential confounders. Finally, a few randomised controlled trials have shown that treatment with simvastatin decreases portal pressure (two studies) and mortality (one study). Statin treatment was generally well tolerated but a few patients developed severe side effects, particularly rhabdomyolysis. Despite these promising beneficial effects, further randomised controlled trials in large series of patients with hard clinical endpoints should be performed before statins can be recommended for use in clinical practice

The kallikrein-kinin pathway as a mechanism for auto-control of brown adipose tissue activity

Brown adipose tissue (BAT) is known to secrete regulatory factors in response to thermogenic stimuli. Components of the BAT secretome may exert local effects that contribute to BAT recruitment and activation. Here, we found that a thermogenic stimulus leads to enhanced secretion of kininogen (Kng) by BAT, owing to induction of kininogen 2 (Kng2) gene expression. Noradrenergic, cAMP-mediated signals induce KNG2 expression and release in brown adipocytes. Conversely, the expression of kinin receptors, that are activated by the Kng products bradykinin and [Des-Arg9]-bradykinin, are repressed by thermogenic activation of BAT in vivo and of brown adipocytes in vitro. Loss-of-function models for Kng (the circulating-Kng-deficient BN/Ka rat) and bradykinin (pharmacological inhibition of kinin receptors, kinin receptor-null mice) signaling were coincident in showing abnormal overactivation of BAT. Studies in vitro indicated that Kng and bradykinin exert repressive effects on brown adipocyte thermogenic activity by interfering the PKA/p38 MAPK pathway of control of Ucp1 gene transcription, whereas impaired kinin receptor expression enhances it. Our findings identify the kallikrein-kinin system as a relevant component of BAT thermogenic regulation that provides auto-regulatory inhibitory signaling to BAT

Urine Monocyte Chemoattractant Protein-1 Is an Independent Predictive Factor of Hospital Readmission and Survival in Cirrhosis.

MCP-1 (monocyte chemoattractant protein-1) is a proinflammatory cytokine involved in chemotaxis of monocytes. In several diseases, such as acute coronary syndromes and heart failure, elevated MCP-1 levels have been associated with poor outcomes. Little is known about MCP-1 in cirrhosis. AIM: To investigate the relationship between MCP-1 and outcome in decompensated cirrhosis. METHODS: Prospective study of 218 patients discharged from hospital after an admission for complications of cirrhosis. Urine and plasma levels of MCP-1 and other urine proinflammatroy biomarkers: osteopontin(OPN), trefoil-factor3 and liver-fatty-acid-binding protein were measured at admission. Urine non-inflammatory mediators cystatin-C, β2microglobulin and albumin were measured as control biomarkers. The relationship between these biomarkers and the 3-month hospital readmission, complications of cirrhosis, and mortality were assessed. RESULTS: 69 patients(32%) had at least one readmission during the 3-month period of follow-up and 30 patients died(14%). Urine MCP-1 and OPN levels, were associated with 3-month probability of readmission (0.85 (0.27-2.1) and 2003 (705-4586) ug/g creat vs 0.47 (0.2-1.1) and 1188 (512-2958) ug/g creat, in patients with and without readmission, respectively; p<0.05; median (IQR)). Furthermore, urine levels of MCP-1 were significantly associated with mortality (1.01 (1-3.6) vs 0.5 (0.2-1.1) μg/g creat, in dead and alive patients at 3 months; p<0.05). Patients with higher levels of urine MCP-1 (above percentile 75th) had higher probability of development of hepatic encephalopathy, bacterial infections or AKI. Urine MCP-1 was an independent predictive factor of hospital readmission and combined end-point of readmission or dead at 3 months. Plasma levels of MCP-1 did not correlated with outcomes. CONCLUSION: Urine, but not plasma, MCP-1 levels are associated with hospital readmission, development of complications of cirrhosis, and mortality. These results suggest that in cirrhosis there is an inflammatory response that is associated with poor outcomes

Characterization of inflammatory response in acute-on-chronic liver failure and relationship with prognosis

ACLF is characterized by a systemic inflammatory response, but the cytokines involved in this process have not been well studied. The aim of this study was to characterize the systemic inflammatory response in patients with cirrhosis and ACLF and its relationship with prognosis. Fifty-five patients with cirrhosis, 26 with ACLF, were studied prospectively. Systemic inflammatory response was analyzed by measuring a large array of plasma cytokines by using a multiplex kit. A principal component analysis show noticeable differences between ACLF and decompensated cirrhosis without ACLF. Patients with ACLF had significant abnormal levels of 12 cytokines compared to those without ACLF, including: VCAM-1, VEGF-A, Fractalkine, MIP-1α, Eotaxin, IP-10, RANTES, GM-CSF, IL-1β, IL-2, ICAM-1, and MCP-1. Cytokines showing the most marked relationship with ACLF were VCAM-1 and VEGF-A (AUCROC 0.77; p = 0.001). There was a significant relationship between some of inflammatory mediators and 3-month mortality, particularly VCAM-1, ICAM-1, and GM-CSF (AUCROC>0.7; p < 0.05). Functional Enrichment Analysis showed that inflammatory markers differentially expressed in ACLF patients were enriched in leukocyte migration, particularly monocytes and macrophages, and chemotaxis pathways. In conclusion, ACLF is characterized by a marked inflammatory reaction with activation of mediators of adhesion and migration of leukocytes. The intensity of the inflammatory reaction correlates with prognosis

A notable proportion of liver transplant candidates with alcohol-related cirrhosis can be delisted because of clinical improvement

Background & Aims To what extent patients with alcohol-related decompensated cirrhosis can improve until recovery from decompensation remains unclear. We aimed to investigate the probability of recovery and delisting due to improvement in patients with alcohol-related decompensated cirrhosis on the waiting list (WL) for liver transplantation (LT). Methods We conducted a registry-based, multicenter, retrospective study including all patients admitted to the LT WL in Catalonia (Spain) with the indication of alcohol-, HCV-, cholestasis- or non-alcoholic steatohepatitis-related decompensated cirrhosis between January 2007 and December 2018. Competing-risk analysis was used to investigate variables associated with delisting due to improvement in patients with alcohol-related decompensated cirrhosis. Criteria for delisting after improvement were not predefined. Outcomes of patients after delisting were also studied. Results One-thousand and one patients were included, 420 (37%) with alcohol-related decompensated cirrhosis. Thirty-six (8.6%) patients with alcohol-related decompensated cirrhosis were delisted after improvement at a median time of 29 months after WL admission. Lower model for end-stage liver disease (MELD) score, higher platelets and either female sex or lower height were independently associated with delisting due to improvement, while time of abstinence did not reach statistical significance in multivariate analysis (p = 0.055). Five years after delisting, the cumulative probability of remaining free from liver-related death or LT was 76%, similar to patients with HCV-related decompensated cirrhosis delisted after improvement. Conclusions A significant proportion of LT candidates with alcohol-related cirrhosis can be delisted due to improvement, which is predicted by low MELD score and higher platelet count at WL admission. Women also have a higher probability of being delisted after improvement, partially due to reduced early access to LT for height discrepancies. Early identification of patients with potential for improvement may avoid unnecessary transplants. Lay summary Patients with alcohol-related cirrhosis can improve until being delisted in approximately 9% of cases. Low model for end-stage liver disease score and high platelet levels at admission predict delisting after improvement, and women have higher probabilities of being delisted due to improvement. Long-term outcomes after delisting are generally favorable

Psychological burden of hepatic encephalopathy on patients and caregivers

Objectives: Hepatic encephalopathy (HE) is common in advanced cirrhosis and is characterized by marked neuropsychiatric abnormalities. However, despite its severity and effects on brain function, the impact of HE on psychological status of patients has not been adequately assessed. The aim of this study was to evaluate the effect of HE on psychological status of patients and their informal caregivers. Methods: Fifteen patients with cirrhosis and episodic or persistent HE and their corresponding informal caregivers were included. Semistructured interviews were performed in patients and caregivers. Quality of life (QoL) was assessed by the short-form 36 in both patients and caregivers, and the Zarit burden score was measured in caregivers. The analysis of interviews was performed using qualitative methodology. Results: HE causes a major psychological impact on patients with HE. The first episode of HE caused a very significant impact that was reported with deep feelings, mainly of fear, anger, misery, anxiety, and sorrow, which persisted with time. Symptoms causing more psychological impact on patients were impaired ability to walk and speak. All effects were associated with a marked impairment in QoL. The psychological impact was also marked in caregivers who had a major burden, as assessed by the Zarit score. Moreover, QoL, particularly the mental component score, was markedly impaired in caregivers in intensity similar to that of patients. Discussion: HE has a profound psychological impact on patients and their informal caregivers, associated with a marked negative influence on QoL. The psychological effects of HE on patients and caregivers should be evaluated and treated

Aging Studies for the Large Honeycomb Drift Tube System of the Outer Tracker of HERA-B

The HERA-B Outer Tracker consists of drift tubes folded from polycarbonate foil and is operated with Ar/CF4/CO2 as drift gas. The detector has to stand radiation levels which are similar to LHC conditions. The first prototypes exposed to radiation in HERA-B suffered severe radiation damage due to the development of self-sustaining currents (Malter effect). In a subsequent extended R&D program major changes to the original concept for the drift tubes (surface conductivity, drift gas, production materials) have been developed and validated for use in harsh radiation environments. In the test program various aging effects (like Malter currents, gain loss due to anode aging and etching of the anode gold surface) have been observed and cures by tuning of operation parameters have been developed.Comment: 14 pages, 6 figures, to be published in the Proceedings of the International Workshop On Aging Phenomena In Gaseous Detectors, 2-5 Oct 2001, Hamburg, German

Adipocyte fatty-acid binding protein is overexpressed in cirrhosis and correlates with clinical outcomes

Fatty-acid-binding proteins (FABPs) are small intracellular proteins that coordinate lipid-mediated processes by targeting metabolic and immune response pathways. The aim of the study was to investigate plasma FABPs levels and their relationship with clinical outcomes in cirrhosis. Plasma levels of L-FABP1(liver and kidney), I-FABP2(intestine), and A-FABP4(adipocyte and macrophages) were measured in 274 patients with decompensated cirrhosis. Hepatic gene expression of FABPs was assessed in liver biopsies from patients with decompensated cirrhosis and in liver cell types from mice with cirrhosis. Immunohistochemistry of A-FABP4 in human liver biopsy was also performed. Plasma levels of FABPs were increased in patients with decompensated cirrhosis compared to those of healthy subjects (L-FABP1: 25 (17-39) vs 10 (9-17) ng/mL p = 0.001, I-FABP2: 1.1 (0.5-2.1) vs 0.6 (0.4-1) ng/ mL p = 0.04 and A-FABP4: 37 (20-68) vs 16 (11-33) ng/mL p = 0.002), respectively. Increased A-FABP4 levels were associated with complications of cirrhosis, acute-on-chronic liver failure and poor survival. Hepatic A-FABP4 gene expression was upregulated in decompensated cirrhosis. Macrophages were the main liver cell that over-expressed A-FABP4 in experimental cirrhosis and increased A-FABP4 was found in macrophages of human biopsies by immunohistochemistry. A-FABP4 levels are increased in decompensated cirrhosis and correlate with poor outcomes. Liver macrophages appear to be the main source of A-FABP4 in decompensated cirrhosis