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The influence of initial planting density (DPI) on the dynamic modulus of elasticity (MOEd) was examinated at a 28 years old Pinus radiata D. Don spacing experiment with four treatments (2500, 1667, 833 and 625 stem ⋅ ha-1 growing on sandy soil, in the Biobio Region, Chile. The MOEd acoustic technology was determined using the method of time of flying (Tv) for standing trees and the resonance method (Res) for two logs of 5 m long, extracted from the tree base to the top of each tree. MOEd was not significantly influenced by DPI in high initial stocking treatments (2500, 1667 an 833 stem ⋅ ha-1), both standing trees and logs level. In contrast, the lowest initial stocking treatment (625 stem ⋅ ha-1) had the highest MOEd significantly different in standing trees and the first the log, and similar between the first and second log. [ABSTRACT FROM AUTHOR]

In Chile, the Immunization Department of the Ministry of Health has carried out the seasonal influenza vaccination campaign annually since 1982 in collaboration with the national health services, regional health offices, and primary health care centres. With the aim of preventing deaths and serious morbidity in high-risk groups and preserving the integrity of health services, the seasonal influenza campaign had been the largest implemented in Chile until 2020, since in 2021 the vaccination campaign against SARS-CoV-2 is expected to become the largest ever implemented. In response to local demographic and epidemiological changes, and taking into account the new scientific evidence on the safety and immunogenicity of vaccines, the influenza vaccines available in Chile would increase annually as a result of campaign planning. In 2020, the influenza campaign had to be re-planned while in progress due to the addition of new high-risk groups to be vaccinated in accordance with the SARS-CoV-2 pandemic health alert modification of March 6th, 2020. Over the course of three weeks, the Immunization Department managed to increase the doses of available influenza vaccines from 6,799,800 previously agreed upon to 8,480,325 and thus serve high-risk groups, guaranteeing their access to state funded influenza vaccination.

Fecal pollution source tracking (FST) studies the origin of fecal contamination and promotes action to eliminate it to improve human health and environmental sustainability. This work presents the temporal and spatial relations of human mitochondrial DNA (HmtDNA), fecal coliforms (FC) and live microbial biomass (ATP) in seawater during a hepatitis A outbreak among a human coastal population. The study area is approximately 100 km along the coastline of the Biobío Region in the southeastern Pacific (Humboldt Current System, Chile). Total data from the swash zone from summer 2015 to autumn 2016 show there were significant positive log-log correlations between FC and HmtDNA (R = 0.32) and ATP (R = 0.31). These correlations were highest during the austral spring of 2015 (R = 0.53 and 0.58 respectively), when HmtDNA also correlated significantly with ATP (R = 0.86). Maximum average values of the parameters measured in this season showed a temporal-spatial concordance with the peak in the number of hepatitis A cases among the nearby coastal population. FC correlated significantly with HmtDNA (R = 0.98) in the water column of the coastal zone close to Concepción Bay during the austral summer of 2016 and in the swash zone of the bay (R = 0.68) throughout the study period. Hepatitis A virus (HAV) has also been detected in organisms and seawater in Concepción Bay, which is consistent with the high incidence of hepatitis A among the coastal population. The concordance between human fecal pollution in the study area and a seasonal hepatitis A outbreak strongly suggests that HmtDNA and its relation with FC and ATP in the coastal zone of marine environments can be used as a proxy to evaluate the risk of outbreaks of thalassogenic diseases., (Copyright © 2019. Published by Elsevier B.V.)

Background: In US and European literature, Legionella pneumophila is reported as an important etiologic agent of severe community-acquired pneumonia (CAP), but in Chile this information is lacking. The aim of this study was to determine the incidence and identify predictors of severe CAP caused by L pneumophila in Santiago, Chile., Methods: A multicenter, prospective clinical study lasting 18 months was conducted; it included all adult patients with severe CAP admitted to the ICUs of four hospitals in Santiago. We excluded patients who were immunocompromised, had been hospitalized in the previous 4 weeks, or presented with another disease during their hospitalization. All data for the diagnosis of severe CAP were registered, and urinary antigens for L pneumophila serogroup 1 were determined., Results: A total of 104 patients with severe CAP were included (mean ± SD age, 58.3 ± 19.3 years; men, 64.4%; APACHE (Acute Physiology and Chronic Health Evaluation) II score, 16.7 ± 6.3; Sepsis-related Organ Failure Assessment score, 6.1 ± 3.2; Pitt Bacteremia Score, 3.4 ± 2.5; Pao2/Fio2, 170.8 ± 87.1). An etiologic agent was identified in 62 patients (59.6%), with the most frequent being Streptococcus pneumoniae (27 patients [26%]) and L pneumophila (nine patients [8.6%]). Logistic regression analysis showed that a plasma sodium level of ≤ 130 mEq/L was an independent predictor for L pneumophila severe CAP (OR, 11.3; 95% CI, 2.5-50.5; P = .002). Global mortality was 26% and 33% for L pneumophila. The Pitt bacteremia score and pneumonia score index were the best predictors of mortality., Conclusions: We found that in Santiago, L pneumophila was second to S pneumoniae as the etiologic agent of severe CAP. Severe hyponatremia at admission appears to be an indicator for L pneumophila etiology in severe CAP.

Citrullinated vimentin (cVIM) is one of the antigens specifically targeted by anti-citrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) patients. The association between ACPA and certain HLA-DRB1 alleles, those coding for the shared epitope (SE), suggests that this response could be T-cell mediated. HLA-DR9 alleles, which do not code for the SE, have recently been associated with ACPA (+) RA. The objective of this work was to study CD4+ T cell responses to cVIM in RA patients and healthy controls carrying HLA-DR9 alleles. Fourteen RA patients and ten healthy controls previously genotyped for HLA-DRB1 were studied for the presence of serum anti-cVIM antibodies by Western blot and ELISA. Peripheral blood mononuclear cells were stimulated with native vimentin and cVIM, and CD4+ T cells proliferation was assessed by flow cytometry. Citrulline-specific CD4+ T cells proliferation was found not only in RA patients but also in healthy controls. Although most patients carrying HLA-DR9 alleles present anti-cVIM antibodies, HLA-DR9 alleles were associated with weaker cVIM-driven CD4+ T-cell responses among RA patients. These results suggest that HLA-DR9 alleles could exert a protective effect on the recognition of cVIM epitopes by CD4+ T cells. In this context, other citrullinated proteins may break T and B cell tolerance, with cVIM only acting as a cross-reactive target for ACPA.

Background: Behçet's disease (BD) is a rare multisystemic inflammatory disease that is potentially disabling and may cause death., Aim: To describe the characteristics of BD patients from two Chilean centers., Patients and Method: Retrospective review of the clinical records of patients with BD attended in two rheumatology services between 1985 and 2007. The "Behçet's Disease Research Committee of Japan" (BDCJ) and the "International Study Group for Behçet's Disease" (ISG) diagnostic criteria were applied., Results: We found 44 cases (25 males), diagnosed as BD. The mean age at the onset of symptoms was 26+/- 12 years. According to BDCJ criteria, 13 patients had complete BD, 24 had incomplete BD and 7 had a suspected BD. Thirty two patients fulfilled the ISG criteria. Forty two patients (95%) had oral ulcers, 33 (75%) had genital ulcers and 29 (66%) had ophthalmological involvement. Eleven and three patients had symptoms of central and peripheral nervous system involvement, respectively. No gender differences were detected., Conclusions: The clinical characteristics of these patients were similar to those described abroad, except for a higher frequency of peripheral nervous system involvement and a lower rate of arthritis.

Objective: To investigate the influence of -308 tumour necrosis factor-alpha (TNFalpha) promoter polymorphism and circulating TNFalpha levels in the clinical response to adalimumab treatment in patients with rheumatoid arthritis (RA)., Methods: Eighty-one patients with active RA were genotyped for the -308 TNFalpha polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis and subdivided into two groups for each polymorphism (G/A and G/G genotype). All received 40 mg of adalimumab subcutaneously every other week. We compared the groups' clinical responses to adalimumab at 8, 16, and 24 weeks using the Disease Activity Score in 28 joints (DAS28)., Results: Both groups showed a significant improvement from baseline. A significant difference between groups was found at week 24. We found that 88.2% of G/G versus 68.4% of G/A for the -308 polymorphism were DAS28 responders (p = 0.05). The score improvement at week 24 was 2.5 +/- 1.3 in the G/G group and 1.8 +/- 1.3 in the G/A group for the -308 polymorphism (p = 0.04). The median of serum TNFalpha levels of the G/A group were lower than those of the G/G group, and statistically different at weeks 8 and 24 (p < 0.039 and p < 0.043). When comparing baseline levels to those achieved at 8, 16, and 24 weeks for the whole group, only responder patients showed a statistically significant overall increase in TNFalpha over time (p < 0.000001)., Conclusion: A relationship between DAS28 improvement, the -308 G/G polymorphism, and increased circulating TNFalpha levels was found in Chilean RA patients treated with adalimumab.

Background: Systemic vasculitis are a group of heterogeneous diseases characterized by inflammation and necrosis of blood vessel walls. The etiology is not known, but geographic and environmental factors are implicated., Aim: To describe the clinical features of microscopic polyangiitis (MPA) and Wegener's granulomatosis (WG) in a Chilean cohort of patients., Patients and Methods: Retrospective review of the medical records of 123 patients with the diagnosis of systemic vasculitis (65 MPA and 58 WG), seen from 1990 to 2001. The diagnosis were made based on the American College of Rheumatology and Chapel Hill criteria., Results: The mean follow-up for MPA was 15 months (1-120) and for WG, 20 months (1-120). The median age (years) at diagnosis for MPA was 61 (19-82) and WG 50 (20-82). Gender distribution was similar in both groups (male: 68% and 57% respectively). The main clinical features in the MPA group were renal involvement (68%), peripheral nervous system involvement (57%), pulmonary hemorrhage (28%), and skin disease (32%). In the WG group were alveolar hemorrhage (62%), renal involvement (78%), paranasal sinus involvement (57%), and ocular disease (26%). In both, creatinine levels above 2.0 mg/dl were associated with a higher mortality (p< 0.01). ANCA by immunofluorescence was performed in 56 MPA patients (75% had pANCA, 4% had cANCA and 21% were ANCA negative) and in 55 WG patients (17% had pANCA, 79% had cANCA and 4% were ANCA negative). Global mortality was 18% and 17% respectively, and the most common causes of death were infections., Conclusions: The clinical features of our patients are similar to other published data. In our WG and MPA patients the main predictor for death was a serum creatinine above 2 mg/dl.

Background: The mainstay of cholesterol reduction therapy is the diet. But the lack of compliance and prescription problems limit its usefulness., Aim: To compare the effectiveness of a nutritional intervention given by a nutritionist with the usual recommendations given by a physician to reduce the LDL cholesterol levels in patients with coronary artery disease, treated at the Regional public hospital in Temuco., Material and Methods: One hundred and forty patients with coronary heart disease (last acute episode at least three months before), without nutritional interventions nor cholesterol-lowering drugs, who gave informed consent, were randomized to receive either instructions by their physician or to take part in a nutritional program. The nutritional intervention consisted in five educational sessions, adapted from the NCEP and from a program of the Nutrition Department of the Catholic University of Chile. Patients randomized to the medical intervention received the standard written recommendations about diet. Lipid profile was measured before the intervention and after a three and twelve months follow up., Results: After one year the group on the nutritionalprogram reduced LDL cholesterol by 11.1% (p=0.03). There were no changes in the medical group. However, only 10% patients on the nutritional intervention group and 8% of those with medical recommendations achieved LDL cholesterol levels less than 100 mg/dl. There were no changes in triglycerides, weight or body mass index during the period., Conclusions: Although this nutritional intervention proved to be more effective than usual medical instructions, most patients on secondary prevention did not achieve acceptable LDL cholesterol levels.

Background: The permanent surveillance of antimicrobial susceptibility of Shigella sp in the Temuco Regional Hospital, allowed us to define the empirical use of antimicrobials in dysenteric syndrome., Aim: To study antimicrobial susceptibility of Shigella strains collected from 1997 to May 2001 and compare the results with those reported in 1990., Material and Methods: Two hundred and seventeen Shigella strains, coming from stool cultures of pediatric patients, were studied., Results: In the period 1989-1990 Shigella flexneri was the main species isolated (83%) whereas, in the period 1997-2001, Shigella sonnei (55.8%) predominated. In the second period, an increase of antimicrobial resistance, as compared with the period 1989-1990, was observed for ampicillin (74.5 and 42% respectively), for cotrimoxazol (57.5 and 45% respectively) and tetracycline (64 and 8% respectively). Chloramphenicol resistance increased from 0 to 57.5%. In the second period no resistance to ciprofloxacin was detected. There was simultaneous resistance to four drugs in 30% of the strains, predominating multiresistance in S flexneri (52.1%)., Conclusions: In the two periods studied, a significant increase was detected in the resistance of Shigella strains to antimicrobials.

The aim of this work was to study the clinical, epidemiological and laboratory features of 90 children, hospitalized between 1988 and 1991 with the diagnosis of acute bacterial meningitis in a region with a high proportion of aboriginal population. Twenty six percent of studied patients were of mapuche origin. The causative organism was identified in 82% of cases (H influenzae in 38% of cases, S pneumoniae in 29% and N meningitidis in 10%). H influenzae was resistant to ampicillin in 16% of cases and resistant to chloramphenicol in 4%. This agent was identified in 52% of patients of mapuche origin compared with 33% of non mapuche patients. Seventy three percent of children were less than 2 years old. Thirty seven percent of children had complications during hospitalization, 12 children died (13.3%) and 38% of children had neurological sequelae at the moment of discharge.