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Monitoring solute fluxes in water quality studies is essential to reveal potential ecosystem disturbances, and is particularly important in Andean headwater catchments as they are the main sources of water for downstream populations. However, such studies have mainly focused on organic matter and nutrients, disregarding other solutes that can threaten water quality (e.g. arsenic, lead, calcium or magnesium). Additionally, routine low-resolution (weekly or monthly) sampling schemes may overlook important solute dynamics. Therefore, we collected water samples every four hours for the analysis of twenty-four solutes in a pristine tropical Andean páramo catchment. Solute fluxes were calculated using five different methods. The 4-hourly data set was filtered to test for an optimum sampling frequency without compromising export rates. Based on the available 4-hourly data, the results showed that the interpolation export method was best suited, due to a weak correlation with discharges. Of the twenty-four solutes analyzed, Dissolved Organic Carbon (DOC), Total Nitrogen bound (TNb), Si, Ca, Mg, K, and Na presented the highest input rates (with DOC = 4.167E+08 mEq km -2 yr -1 and Si = 1.729E+07 mEq km -2 yr -1 ) and export rates (with DOC = 2.686E+08 mEq km -2 yr -1 and Si = 2.953E+08 mEq km -2 yr -1 ). Moreover, DOC, TNb, NH 4 -N, NO 2 -N, NO 3 -N, PO 4 , Al, B, Cu, Fe, Zn, As, Cd, Cr, Pb, and V presented more input than export, while Ca, K, Mg, Na, Rb, Si, Sr, and Ba presented more export than input (geogenic sources). Filtered sampling frequencies demonstrated that a minimum of daily grab samples would be required to obtain reliable export rates with differences consistently below 10%, when compared to the 4-hourly solute export. These findings can be particularly useful for the implementation of long-term monitoring programs at low cost, and they provide high-quality information, for the first time, on biogeochemical budgets in a pristine páramo catchment., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Patricio Crespo reports financial support was provided by International Atomic Energy Agency (IAEA). Patricio Crespo reports financial support was provided by Ecuadorian Secretary of Higher Education, Science, Technology and Innovation (SENESCYT)., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background & Aims: Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Most studies addressing the epidemiology of HCC originate from developed countries. This study reports the preliminary findings of a multinational approach to characterize HCC in South America., Methods: We evaluated 1336 HCC patients seen at 14 centres in six South American countries using a retrospective study design with participating centres completing a template chart of patient characteristics. The diagnosis of HCC was made radiographically or histologically for all cases according to institutional standards. Methodology of surveillance for each centre was following AASLD or EASL recommendations., Results: Sixty-eight percent of individuals were male with a median age of 64 years at time of diagnosis. The most common risk factor for HCC was hepatitis C infection (HCV, 48%), followed by alcoholic cirrhosis (22%), Hepatitis B infection (HBV, 14%) and NAFLD (9%). We found that among individuals with HBV-related HCC, 38% were diagnosed before age 50. The most commonly provided therapy was transarterial chemoembolization (35% of HCCs) with few individuals being considered for liver transplant (<20%). Only 47% of HCCs were diagnosed during surveillance, and there was no difference in age of diagnosis between those diagnosed incidentally vs by surveillance. Nonetheless, being diagnosed during surveillance was associated with improved overall survival (P = .01)., Conclusions: Our study represents the largest cohort to date reporting characteristics and outcomes of HCC across South America. We found an important number of HCCs diagnosed outside of surveillance programmes, with associated increased mortality in those patients., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Hepatic dysfunction frequently develops in patients infected with the human immunodeficiency virus (HIV). This retrospective study was undertaken to determine the laparoscopic and histologic findings in a group of HIV-seropositive patients with or without the acquired immune deficiency syndrome (AIDS). Fifty-four patients, 44 with AIDS and 10 HIV-positive, underwent laparoscopic examination and visually guided biopsies for the assessment of clinical or biochemical evidence of liver injury. Significant abnormalities were detected in 31/44 (70%) AIDS patients and 3/10 (30%) HIV-positive patients. Overall, specific laparoscopic findings were described in 25/54 (46%). The most common findings were peritoneal involvement, massive intra-abdominal adhesions, focal lesions of the liver or spleen, and diffuse nodularity of the liver; these were usually related to opportunistic infections or neoplasms such as non-Hodgkin's lymphomas and Kaposi's sarcoma. No procedure-related deaths occurred. Laparoscopy is a safe and accurate method to detect underlying disease in a selected population of HIV-seropositive patients.

Chronic hepatitis B virus infection is closely associated with the development of hepatocellular carcinoma, which is a major cause of cancer death worldwide. Recent studies have implicated hepatitis C virus infection as a major pathogenic agent of HBsAg-negative hepatocellular carcinoma. The significance of hepatitis C virus and hepatitis B virus infections in the occurrence of HBsAg-negative hepatocellular carcinoma has not been well established in the United States. We studied 91 HBsAg-negative American patients with hepatocellular carcinoma for evidence of hepatitis C virus or hepatitis B virus infection. These patients had no other predisposing factors to hepatocellular carcinoma. A sensitive polymerase chain reaction was employed to detect hepatitis C virus RNA and hepatitis B virus DNA in serum and liver. Three sets of hepatitis C virus and hepatitis B virus primers were used to optimize the detection of viral genomes. Hepatitis C virus antibodies were measured with second-generation immunoassays. Twenty-six (29%) of these patients carried low levels of hepatitis B virus DNA in either serum, liver/tumor tissue or both. On the basis of the results from serological and polymerase chain reaction analyses of serum and liver, we found that 53 of 91 patients (58%) exhibited evidence of hepatitis C virus infection. When data were combined, 14 patients (15%) had evidence of hepatitis B virus/hepatitis C virus coinfection, whereas 12 (13%) were infected with hepatitis B virus alone and 39 (43%) had hepatitis C virus only. Twenty-six (29%) had no markers of hepatitis B virus or hepatitis C virus infection.(ABSTRACT TRUNCATED AT 250 WORDS)