Changes in net ecosystem exchange over Europe during the 2018 drought based on atmospheric observations.

The 2018 drought was one of the worst European droughts of the twenty-first century in terms of its severity, extent and duration. The effects of the drought could be seen in a reduction in harvest yields in parts of Europe, as well as an unprecedented browning of vegetation in summer. Here, we quantify the effect of the drought on net ecosystem exchange (NEE) using five independent regional atmospheric inversion frameworks. Using a network of atmospheric CO2 mole fraction observations, we estimate NEE with at least monthly and 0.5° × 0.5° resolution for 2009-2018. We find that the annual NEE in 2018 was likely more positive (less CO2 uptake) in the temperate region of Europe by 0.09 ± 0.06 Pg C yr-1 (mean ± s.d.) compared to the mean of the last 10 years of -0.08 ± 0.17 Pg C yr-1, making the region close to carbon neutral in 2018. Similarly, we find a positive annual NEE anomaly for the northern region of Europe of 0.02 ± 0.02 Pg C yr-1 compared the 10-year mean of -0.04 ± 0.05 Pg C yr-1. In both regions, this was largely owing to a reduction in the summer CO2 uptake. The positive NEE anomalies coincided spatially and temporally with negative anomalies in soil water. These anomalies were exceptional for the 10-year period of our study. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

The fingerprint of the 2018 drought in Europe on ground-based atmospheric CO2 measurements.

During the summer of 2018, a widespread drought developed over Northern and Central Europe. The increase in temperature and the reduction of soil moisture have influenced carbon dioxide (CO2) exchange between the atmosphere and terrestrial ecosystems in various ways, such as a reduction of photosynthesis, changes in ecosystem respiration, or allowing more frequent fires. In this study, we characterize the resulting perturbation of the atmospheric CO2 seasonal cycles. 2018 has a good coverage of European regions affected by drought, allowing the investigation of how ecosystem flux anomalies impacted spatial CO2 gradients between stations. This density of stations is unprecedented compared to previous drought events in 2003 and 2015, particularly thanks to the deployment of the Integrated Carbon Observation System (ICOS) network of atmospheric greenhouse gas monitoring stations in recent years. Seasonal CO2 cycles from 48 European stations were available for 2017 and 2018. Earlier data were retrieved for comparison from international databases or national networks. Here, we show that the usual summer minimum in CO2 due to the surface carbon uptake was reduced by 1.4 ppm in 2018 for the 10 stations located in the area most affected by the temperature anomaly, mostly in Northern Europe. Notwithstanding, the CO2 transition phases before and after July were slower in 2018 compared to 2017, suggesting an extension of the growing season, with either continued CO2 uptake by photosynthesis and/or a reduction in respiration driven by the depletion of substrate for respiration inherited from the previous months due to the drought. For stations with sufficiently long time series, the CO2 anomaly observed in 2018 was compared to previous European droughts in 2003 and 2015. Considering the areas most affected by the temperature anomalies, we found a higher CO2 anomaly in 2003 (+3 ppm averaged over 4 sites), and a smaller anomaly in 2015 (+1 ppm averaged over 11 sites) compared to 2018. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

Single-Dose Universal Hepatitis A Immunization in Argentina: Low Viral Circulation and High Persistence of Protective Antibodies Up to 4 Years.

BACKGROUND: Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean children aged 12 months in 2005. Between 2005 and 2011, a dramatic decline was observed in HAV infection rates, fulminant hepatitis, and liver transplantation. This study assessed current viral circulation and estimated protective antibody persistence 4 years after vaccination. METHODS: Prevalence of prevaccination anti-HAV antibodies in 12-month-old children was evaluated as an indirect estimation of viral circulation (Group A). Seroprevalence was also measured in 5-year-old children who received 1 dose of HAV vaccine at 1 year of age (Group B). Blood samples were tested for immunoglobulin (Ig)G anti-HAV antibodies (seroprotection = ≥10 mIU/mL). All Group A-positive samples were tested for IgM anti-HAV antibodies to identify recent infections. Logistic regression analysis was done to evaluate associations between demographic and socioeconomic variables and seroprotection. RESULTS: Of 433 children from Group A, 29.5% (95% confidence interval [CI], 25.2-33.8) were positive for IgG anti-HAV antibodies with a geometric mean concentration (GMC) of 6.17 mIU/mL (95% CI, 5.33-7.15 mIU/mL); all IgM anti-HAV were negative. From 1139 in Group B, 93% (95% CI, 91.7-94.6) maintained seroprotection with a GMC of 97.96 mIU/mL (95% CI, 89.21-107.57 mIU/mL). Kindergarten attendance was associated with seroprotection in Group B (odds ratio [OR], 2.0; 95% CI, 1.26-3.3). In contrast, high maternal educational level was associated with a lack of seroprotection in this group (OR, .26; 95% CI, .09-.8). CONCLUSIONS: Single-dose, universal hepatitis A immunization in infants resulted in low HAV circulation and persistent immunologic protection up to 4 years in Argentina. Variables associated with presence or absence of seroprotection in vaccinated children could be related to differences in hygiene habits in settings with residual viral circulation.

Economic analysis of the single-dose immunization strategy against hepatitis A in Argentina.

BACKGROUND: Vaccination against hepatitis A (HA) was carried out only as part of a limited outbreak control strategy in Argentina until June 2005, when universal immunization in infants was introduced into the national immunization calendar. A single-dose strategy was chosen instead of the standard two-dose schedule used elsewhere. This study aimed to estimate preventive, medical, and non-medical costs related to HA and to compare these costs in the periods before and after mass vaccination. METHODS: A retrospective analysis estimated treatment costs of HA and unspecified hepatitis cases reported to the National Health Surveillance System from 2000 to 2010. Costs related to immunization, fulminant hepatitis (FH), liver transplantation, and death were projected as well. Using a social perspective and a healthcare system perspective, costs in two 5-year periods were compared: 2000-2004 versus 2006-2010. Finally, we evaluated the impact of different discount rates, FH risk, and exclusion of unspecified hepatitis cases in the sensitivity analysis. RESULTS: Total HA and unspecified hepatitis cases decreased from 157,871 in 2000-2004 to 17,784 in 2006-2010. Medical and non-medical costs decreased from US$11,811,600 and US$30,118,222 to US$1,252,694 and US$4,995,895 in those periods, respectively. Immunization costs increased from US$6,506,711 to US$40,912,132. Total preventive, medical, and non-medical costs decreased from US$48,436,534 to US$47,160,721, representing a 2.6% reduction in total costs between the two periods. When a healthcare system perspective was considered or unspecified hepatitis cases were excluded, total costs were 130.2% and 30.8% higher in 2006-2010 than in the previous period, respectively. CONCLUSION: After implementation of the universal single-dose vaccination against HA in infants in Argentina, an impressive decline was observed in HA cases, with a decrease in medical and non-medical costs in the first 5 years. The single-dose strategy, which is simpler and less expensive than the standard two-dose scheme, can be a good alternative for future vaccination policies in other countries where HA is endemic.

Prognostic factors in paediatric acute liver failure.

OBJECTIVES: To study the aetiology, outcome and prognostic indicators in children with acute liver failure (ALF). STUDY DESIGN: Retrospective chart review of 210 patients (107 males/103 females; median age: 5.33 years, range: 1-17.4). Patients were followed until discharge (group 1), death (group 2) or liver transplantation (LT; group 3). Data from group 1 were compared to data from the other two groups and King's College criteria were also assessed. RESULTS: Final diagnoses were: 128 (61%) hepatitis A, 68 (32%) indeterminate and 14 (7%) others. The characteristics of patients who survived (n = 59), died (n = 61) and underwent LT (n = 90) were analysed. In multivariate analysis, prothrombin time and encephalopathy III/IV were the most significant parameters suggesting a high likelihood of death. When King's College criteria were applied on admission in patients with and without transplantation, the positive predictive values were 96% and 95%, and the negative predictive values were 82% and 82%, respectively. CONCLUSIONS: Hepatitis A is the main cause of ALF in children in Argentina. Advanced encephalopathy and prolonged prothrombin time were significantly associated with death or need for LT. King's College criteria for predicting the outcome of ALF are applicable in children, including those with ALF due to hepatitis A infection.

Contribution of anthropogenic and natural sources to atmospheric methane variability.

Methane is an important greenhouse gas, and its atmospheric concentration has nearly tripled since pre-industrial times. The growth rate of atmospheric methane is determined by the balance between surface emissions and photochemical destruction by the hydroxyl radical, the major atmospheric oxidant. Remarkably, this growth rate has decreased markedly since the early 1990s, and the level of methane has remained relatively constant since 1999, leading to a downward revision of its projected influence on global temperatures. Large fluctuations in the growth rate of atmospheric methane are also observed from one year to the next, but their causes remain uncertain. Here we quantify the processes that controlled variations in methane emissions between 1984 and 2003 using an inversion model of atmospheric transport and chemistry. Our results indicate that wetland emissions dominated the inter-annual variability of methane sources, whereas fire emissions played a smaller role, except during the 1997-1998 El Niño event. These top-down estimates of changes in wetland and fire emissions are in good agreement with independent estimates based on remote sensing information and biogeochemical models. On longer timescales, our results show that the decrease in atmospheric methane growth during the 1990s was caused by a decline in anthropogenic emissions. Since 1999, however, they indicate that anthropogenic emissions of methane have risen again. The effect of this increase on the growth rate of atmospheric methane has been masked by a coincident decrease in wetland emissions, but atmospheric methane levels may increase in the near future if wetland emissions return to their mean 1990s levels.

Pediatric and adult forms of type I autoimmune hepatitis in Argentina: evidence for differential genetic predisposition.

The aim of this study was to compare major histocompatibility complex (MHC) class II susceptibility to type 1 autoimmune hepatitis (AH) between children and adults of the same ethnic group. HLA-DRB1, HLA-DRB3, HLA-DQA1, and HLA-DQB1 gene subtypes were examined by high resolution oligonucleotide typing in 122 pediatric (PAH) and 84 adult (AAH) patients and in 208 controls. In children, HLA-DRB1*1301 was the primary susceptibility allele (66.4% patients vs. 10.6% controls, relative risk [RR] = 16.3, Pc < 10(-24)) whereas HLA-DRB1*1302, which differs from HLA-DRB1*1301 by only 1 amino acid, appeared to be protective. The exclusion of individuals with HLA-DRB1*1301 from control and pediatric patients allowed us to find a secondary association of PAH with HLA-DRB1*0301. Possession of HLA-DRB1*1301, however, was associated with a lower therapeutic response rate. Analysis of peptide binding pocket residues indicated that Tyr 10, Ser 11, Ser 13, and Val 86 in the class II beta chain were present in 85% of patients compared with 37% of controls, suggesting that a high proportion of AH susceptibility is attributable to these residues (etiologic fraction [EF] = 76%). In contrast to the class II associations in children, AAH was associated with HLA-DRB1*0405 (RR = 10.4, Pc <.005) but not with HLA-DRB1*1301 or HLA-DRB1*0301. In addition, HLA-DR4 with the class I gene, HLA-A11, appeared synergistic in predisposing AAH patients to develop extra-hepatic autoimmune (AI) manifestations (odds ratio [OR] = 104.9, Pc < 10(-4)). Concomitant differences in autoantibody profiles were also observed in PAH versus AAH: smooth muscle antibodies (SMA) were most prevalent in PAH but antinuclear antibodies were most prevalent in AAH (P =.003). This study therefore reveals that different HLA-DRB1 allotypes confer susceptibility to AH in children and adults and raises the possibility that PAH and AAH may be triggered by different factors.

Short-term cyclosporine induces a remission of autoimmune hepatitis in children.

BACKGROUND/AIMS: The current immunosuppressive treatment of patients with autoimmune hepatitis consists of prednisone and azathioprine. High doses of prednisone used to obtain the remission of the disease are associated with serious adverse effects. To avoid harmful consequences of prednisone therapy, we proposed to treat patients with oral cyclosporine to obtain the remission of the inflammatory process. METHODS: This is a pilot, multinational, multicenter, clinical trial involving children with autoimmune hepatitis. Thirty-two children were recruited, who according to international criteria were considered as having definite autoimmune hepatitis. Cyclosporine alone was administered for 6 months, followed by combined low doses of prednisone and azathioprine for 1 month, after which cyclosporine was discontinued. Biochemical remission of the disease was established by the follow-up of serum transaminase activity levels. Growth parameters and adverse effects of the treatment were recorded. RESULTS: Two patients were withdrawn from the study: one for non-compliance and the other for liver failure which did not improve with cyclosporine. Of the 30 remaining patients, 25 normalized alanine aminotransferase activity levels by 6 months and all the patients by 1 year of treatment. Z-scores for height showed a trend towards improvement during treatment. Adverse effects of cyclosporine were mild and disappeared during weaning off the medication. CONCLUSIONS: Cyclosporine induced the biochemical remission of the hepatic inflammatory/necrotic process in children with autoimmune hepatitis, with few and well-tolerated adverse effects.

Chronic active autoimmune hepatitis in children. Strong association with a particular HLA-DR6 (DRB1*1301) haplotype.

The association of HLA antigens and type I or "lupoid" CAH-C was investigated in a population of 52 Argentinian Caucasoid patients. When compared with a population of normal individuals of the same ethnic group (n = 197), a significant increase of HLA-DR6 was observed (68.6% in patients vs 17.3% in controls; RR = 12.3, chi 2 = 52.4, pc = 0.00001). DNA typing showed that the HLA-DRB1*1301 allele was present in 32 out of 33 HLA-DR6 patients (66.6% of all the C-CAH patients vs 10.5% in controls; RR = 16.2, chi 2 = 111.3, pc = 0.00001). Analysis of HLA-DQB1 alleles also showed a significant increase of DQB1*0603 (RR = 15.4, chi 2 = 106.5, pc = 0.00001), an allele found in strong linkage disequilibrium with DRB1*1301. The association of CAH-C with this particular HLA-DR6 haplotype has not been previously described for the adult onset CAH. This different HLA predisposition, together with the fact that extrahepatic autoimmune diseases occur frequently only in the adult form of the disease, suggest that the immunopathogenic mechanisms involved in the development of these diseases may be different.

Giardiasis. Functional, immunological and histological study of the small bowel. Therapeutic trial with a single dose of tinidazole.

Fourteen patients between the ages of 9 months and 5 years with chronic diarrhea and giardiasis were studied. Ten were eutrophic and 4 undernourished. The parasitological diagnosis was based on stool examination, a trophozoite search in duodenal aspiration, mucus adhered to mucosa and parasite identification in the intestinal biopsy material. Functional intestinal absorption studies, IgA determination in intestinal secretions and immunofluorescence studies were made. After the tests, tinidazole in suspension was administered at 60-70 mg/kg in one single oral dose. Patients were clinically re-evaluated and tests were done again after 30 days. The purpose of this paper was to evaluate the changes in the functional morphologic and immunologic studies and the therapeutic efficacy of the drug in a single dose. Nine patients had good clinical results, 2 fair and 3 were not evaluated due to celiac disease. All had negative results on the parasitological tests after treatment. There was no relationship between the number of parasites and the severity of symptoms. There was no significant difference between stool fat and d-xylose at the time of diagnosis and 30 days after the administration of tinidazole. The lactose tolerance test presented a significant difference (p less than 0.05) in the disaccharide absorption after treatment. The secretory IgA revealed significantly lower value (p less than 0.01) with respect to the normal values. The immunofluorescence showed productive IgA cells in all cases. The histologic changes were: mild enteropathy (grade I) in 6 patients; moderate (grade II) in 5; and severe (grade III-IV) in 3. Improvement of the mucosa was seen in 6 patients.

[Liver ultrastructure in congenital atresia of the extrahepatic bile ducts]. / Ultraestructura del hígado en la atresia congénita de las vías biliares extrahepáticas.

Seven patients with diagnosis of biliary atresia (BA) and two patients with neonatal hepatitis were studied by electron microscopy. In all patients the diagnosis was done by clinical examinations, laboratory assays, histological studies by punch or surgical biopsies and or surgical examinations combined with intraoperatory cholangiography. The ultrastructural alterations found in both groups of patients were essentially similar to those described in other forms of cholestasis. In patients suffering from biliary atresia the main features found at hepatocytic livel were: Finely granular deposits of electron dense substance sometimes conforming lamellar structures; 2) Some increase and vesiculation of smooth endoplasmic reticulum membranes; 3) Reductions in number and length of sinusoidal microvilli; in some areas was also detected basal membrane and an increase in the amount of collagen fibers in the space of Disse; 4) Marked bile canaliculi dilatations with reduction of microvilli and thickening of the pericanalicular surrounding area, some canaliculi were constitued by several hepatocytes. Ductules were found in only 3 cases with the following alterations: 1) Intracytoplasmic electron dense deposits of granular material without limiting membranes; 2) A marked increase in the number of microfilaments mainly located in the apical portion of the cell or in the vicinity of the nuclei; 3) Inflammatory cells in the duct epithelium or in direct contact with the hepatocytes. The ultrastructural findings in the two cases of neonatal hepatitis (NH) resembled those described in the biliary atresia.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultraestructura del hígado en la atresia congénita de las vías biliares extrahepáticas. / [Liver ultrastructure in congenital atresia of the extrahepatic bile ducts]

Seven patients with diagnosis of biliary atresia (BA) and two patients with neonatal hepatitis were studied by electron microscopy. In all patients the diagnosis was done by clinical examinations, laboratory assays, histological studies by punch or surgical biopsies and or surgical examinations combined with intraoperatory cholangiography. The ultrastructural alterations found in both groups of patients were essentially similar to those described in other forms of cholestasis. In patients suffering from biliary atresia the main features found at hepatocytic livel were: Finely granular deposits of electron dense substance sometimes conforming lamellar structures; 2) Some increase and vesiculation of smooth endoplasmic reticulum membranes; 3) Reductions in number and length of sinusoidal microvilli; in some areas was also detected basal membrane and an increase in the amount of collagen fibers in the space of Disse; 4) Marked bile canaliculi dilatations with reduction of microvilli and thickening of the pericanalicular surrounding area, some canaliculi were constitued by several hepatocytes. Ductules were found in only 3 cases with the following alterations: 1) Intracytoplasmic electron dense deposits of granular material without limiting membranes; 2) A marked increase in the number of microfilaments mainly located in the apical portion of the cell or in the vicinity of the nuclei; 3) Inflammatory cells in the duct epithelium or in direct contact with the hepatocytes. The ultrastructural findings in the two cases of neonatal hepatitis (NH) resembled those described in the biliary atresia.(ABSTRACT TRUNCATED AT 250 WORDS)

Circulating antibodies to cow's milk proteins in children with acute diarrhoea.

Circulating antibodies to cow's milk protein were investigated in 35 normally nourished infants aged 2 to 11 months. Nine were healthy (control group), and the remaining 26 were convalescents from acute diarrhoea. At the time of assay they were normally hidrated and being fed diluted cow's milk. The results showed elevated hemagglutinating antibody titers in the group of children with diarrhoea, statistically different to the control (p less than 0.001). The existence of an enhanced absorption of non degraded milk protein during the disease is assumed. This observation constitutes one more element in favour of the risk of exposing the digestive tract to antigenic loads in pathological situations as those considered.