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1.
J Intern Med ; 289(1): 116-120, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32729633

RESUMO

IMPORTANCE: COVID-19 is caused by SARS-CoV-2, a betacoronavirus that uses the angiotensin-converting enzyme-related carboxypeptidase (ACE2) receptor to gain entry into cells. ACE2 receptor is widely expressed in multiple organs, including the retina, an extension of the central nervous system. The ACE2 receptor is involved in the diabetic and hypertensive retinopathy. Additionally, coronaviruses cause ocular infections in animals, including retinitis, and optic neuritis. OBJECTIVE: To assess whether there is any retinal disease associated with COVID-19. DESIGN: We have evaluated 27 asymptomatic subjects, with retinal fundoscopic, optical coherence tomography (OCT) and OCT angiography fourteen days after hospital discharge due to COVID-19 bilateral pneumonia. RESULTS: Cotton wool exudates were evident in six out of 27 patients evaluated, a 22%. Cotton wool exudates are a marker vascular disease severity in other medical context, that is diabetes and hypertension, and are associated with increased risk for acute vascular events. Whether antiaggregation therapy may play a role on fundoscopic-selected patients with COVID-19 requires prospective trials.


Assuntos
COVID-19/complicações , Doenças Cardiovasculares/epidemiologia , Retina/patologia , Doenças Retinianas/etiologia , SARS-CoV-2 , COVID-19/epidemiologia , Comorbidade , Feminino , Angiofluoresceinografia , Seguimentos , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos Prospectivos , Doenças Retinianas/diagnóstico , Tomografia de Coerência Óptica
2.
Int J Biometeorol ; 59(12): 1849-60, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25906047

RESUMO

The aim of this work was to analyze spatial phenology and grape quality variability related to the climatic characteristics within the Ribera del Duero Designation of Origin (DO). Twenty plots planted with cv. Tempranillo and distributed within the DO were analyzed for phenology from 2004 to 2013. Grape quality parameters at ripening (berry weight, sugar content, acidity and pH, and anthocyanins) were analyzed in 26 plots for the period 2003-2013. The relationships between phenology and grape parameters with different climatic variables were confirmed with a multivariate analysis. On average, bud break was April 27(th), bloom June 17(th), and veraison August 12th. However, phenology during the time period showed high variability, with differences between years of up to 21 days for a phenology stage. The earliest dates were observed in dry years (2005, 2006, and to a lesser degree in 2009) while the later phenology dates occurred in the wettest year of the period (2008). High correlations were found between veraison date and temperature variables as well as with precipitation-evapotranspiration recorded during the bloom-veraison period. These effects tended to be higher in the central part of the DO. Grape quality parameters also showed high variability among the dry and the wet years, and the influence of extreme temperatures on color development as well as the effect of available water on acidity were observed.


Assuntos
Clima , Vitis/crescimento & desenvolvimento , Estações do Ano , Espanha , Temperatura
3.
Antimicrob Agents Chemother ; 58(7): 4227-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24798272

RESUMO

Mitochondrial toxicity has been recently suggested to be the underlying mechanism of long-term linezolid-associated toxicity in patients with 16S rRNA genetic polymorphisms. Here, we report for the first time two cases of lactic acidosis due to long-term linezolid exposure in liver transplant recipients who presented an A2706G mitochondrial DNA polymorphism.


Assuntos
Acetamidas/efeitos adversos , Acidose Láctica/induzido quimicamente , DNA Mitocondrial/genética , Mitocôndrias/genética , Oxazolidinonas/efeitos adversos , Acetamidas/uso terapêutico , Acidose Láctica/terapia , Adulto , Idoso , Feminino , Predisposição Genética para Doença , Humanos , Linezolida , Transplante de Fígado , Masculino , Nocardiose/tratamento farmacológico , Nocardia asteroides/efeitos dos fármacos , Oxazolidinonas/uso terapêutico , Polimorfismo de Nucleotídeo Único , RNA Ribossômico 16S/genética , Tuberculose Pulmonar/tratamento farmacológico
4.
Eur J Clin Microbiol Infect Dis ; 33(4): 651-8, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24162256

RESUMO

The purpose of this investigation was to compare the genotypic profiles of Staphylococcus aureus isolated from atopic dermatitis (AD) patients and from control subjects, and to study the relationship between clinical severity, immune response, and genomic pattern of S. aureus isolated from AD patients. We selected 32 patients with AD and S. aureus skin colonization and 31 atopic controls with no history of AD who where asymptomatic carriers of S. aureus. Microarray-based genotyping was performed on S. aureus isolates. In AD patients, clinical severity was assessed using the Scoring Atopic Dermatitis index and total IgE levels and staphylococcal superantigen-specific IgE levels (SEA, SEB, SEC, TSST1) were determined. The genes lukE, lukD, splA, splB, ssl8, and sasG were more frequent in isolates from AD patients. CC30 was more common in isolates from atopic controls than in AD patients. There was a correlation between total IgE and clinical severity, but an association between clinical severity, immune response, and the presence of S. aureus superantigen genes, including enterotoxin genes, could not be demonstrated. Finally, a correlation was found between AD severity and other S. aureus genes, such as sasG and scn. S. aureus factors besides superantigens could be related to the worsening and onset of AD.


Assuntos
Dermatite Atópica/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Superantígenos/genética , Adolescente , Adulto , Doenças Assintomáticas , Estudos de Casos e Controles , Criança , Pré-Escolar , Dermatite Atópica/imunologia , Feminino , Genes Bacterianos , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/imunologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/patogenicidade , Superantígenos/imunologia , Virulência/genética , Adulto Jovem
5.
Sci Total Environ ; 912: 169133, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38070551

RESUMO

Downed woody debris (DWD) plays an important role as regulator of nutrient and carbon (C) cycling in forests, accounting for up to the 20 % of the total C stocks in primary forests. DWD persistence is highly influenced by microbial decomposition, which is determined by various environmental factors, including fluctuations in temperature and moisture, as well as in intrinsic DWD properties determined by species, diameter, or decay classes (DCs). The relative importance of these different drivers, as well as their interactions, remains largely unknown. Moreover, the importance of DWD for C cycling in virgin forests remains poorly understood, due to their scarcity and poor accessibility. To address this research gap, we conducted a study on DWD respiration (RDWD), in a temperate virgin forest dominated by European beech and silver fir. Our investigation analysed the correlation between RDWD of these two dominant tree species and the seasonal changes in climate (temperature and moisture), considering other intrinsic DWD traits such as DCs (1, 2 and 4) and diameters (1, 10 and 25 cm). As anticipated, RDWD (normalized per gram of dry DWD) increased with air temperature. Surprisingly, DWD diameter also had a strong positive correlation with RDWD. Nonetheless, the sensitivity to both variables and other intrinsic traits (DC and density) was greatly modulated by the species. On the contrary, water content, which exhibited a considerable spatial variation, had an overall negative effect on RDWD. Virgin forests are generally seen as ineffective C sinks due to their lack of net productivity and high respiration and nutrient turnover. However, the rates of RDWD in this virgin forest were significantly lower than those previously estimated for managed forests. This suggests that DWD in virgin forests may be buffering forest CO2 emissions to the atmosphere more than previously thought.


Assuntos
Carbono , Microclima , Florestas , Madeira , Árvores
6.
Open Biol ; 13(5): 220370, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37192671

RESUMO

Nitric oxide (NO) plays a pivotal role in integrating dopamine transmission in the basal ganglia and has been implicated in the pathogenesis of Parkinson disease (PD). The objective of this study was to ascertain whether the NO synthase inhibitor, 7-nitroindazole (7-NI), is able to reduce L-DOPA-induced dyskinesias (LIDs) in a non-human primate model of PD chronically intoxicated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Six Parkinsonian macaques were treated daily with L-DOPA for 3-4 months until they developed LIDs. Three animals were then co-treated with a single dose of 7-NI administered 45 min before each L-DOPA treatment. Dyskinetic MPTP-treated monkeys showed a significant decrease in LIDs compared with their scores without 7-NI treatment (p < 0.05). The anti-Parkinsonian effect of L-DOPA was similar in all three monkeys with and without 7-NI co-treatment. This improvement was significant with respect to the intensity and duration of LIDs while the beneficial effect of L-DOPA treatment was maintained and could represent a promising therapy to improve the quality of life of PD patients.


Assuntos
Discinesia Induzida por Medicamentos , Doença de Parkinson , Transtornos Parkinsonianos , Animais , Levodopa/efeitos adversos , Antiparkinsonianos/efeitos adversos , Qualidade de Vida , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/tratamento farmacológico , Discinesia Induzida por Medicamentos/tratamento farmacológico , Discinesia Induzida por Medicamentos/etiologia , Doença de Parkinson/tratamento farmacológico , Primatas
7.
Eur J Clin Microbiol Infect Dis ; 31(9): 2445-52, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22395261

RESUMO

Inappropriate antibiotic prescriptions are associated with an increase in healthcare costs and a decrease in the quality of care. The aim of this study was to measure the clinical and economic impact of rapid microbiological reporting on the specimens most frequently processed by the Microbiology Laboratory. The Vitek® 2 system (bioMérieux) was used for identification and susceptibility testing. Only hospitalized patients with bacterial infections were included. Two groups were established, a historical control group (results available the day following the analysis) and an intervention group (results available the same day of the analysis). Specimens studied and the median length of time from the introduction of the microorganism in the Vitek® 2 until microbiological report were as follows: wound and abscess (control = 23.5 h, intervention = 9.5 h, p < 0.001), blood (control = 23.5 h, intervention = 9.2 h, p < 0.001), and urine (control = 23.4 h, intervention = 9.3 h, p < 0.001). Outcome parameters were hospital stay and mortality rates. Hospital costs were calculated. The mortality rates did not differ significantly between the two groups. Faster reporting of identification and antimicrobial susceptibility results was associated with a significant reduction in hospital stay and in overall costs for those patients from whom wound, abscess, and urine specimens were analyzed. However, the antimicrobial results of blood culture isolates did not lead to significant clinical or financial benefits.


Assuntos
Antibacterianos/administração & dosagem , Bactérias/classificação , Bactérias/efeitos dos fármacos , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/tratamento farmacológico , Testes de Sensibilidade Microbiana/métodos , Infecções Bacterianas/economia , Feminino , Custos Hospitalares/estatística & dados numéricos , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Análise de Sobrevida , Fatores de Tempo
8.
Infection ; 40(4): 445-9, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22706637

RESUMO

Candida osteomyelitis is a well recognized but infrequent entity. We describe an interesting case of iliac bone C. albicans osteomyelitis as a result of a surgical trauma of an iliac bone for the auto-grafting of a fracture in the lumbar spine. The peri-operative acquisition of Candida was by the inoculation of a yeast colonizing the skin. Remarkably, several risk factors described for Candida infection and candidemia were absent. The patient also presented with a local fistula. The iliac crest was the only bone affected and local pain was the only symptom present in our case. Diagnosis was made by multiple-specimen biopsy obtained by surgery. Treatment with fluconazole was successful.


Assuntos
Transplante Ósseo , Candida albicans/isolamento & purificação , Ílio/microbiologia , Ílio/transplante , Vértebras Lombares , Osteomielite/etiologia , Fraturas da Coluna Vertebral/cirurgia , Adulto , Antifúngicos/uso terapêutico , Transplante Ósseo/efeitos adversos , Feminino , Fluconazol/uso terapêutico , Humanos , Osteomielite/tratamento farmacológico , Transplante Autólogo
9.
Acta Anaesthesiol Scand ; 56(10): 1332-5, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22834896

RESUMO

Spontaneous intracranial hypotension (SIH) is considered to be a very rare disease. It is characterised by an orthostatic headache in the absence of a past history of a trauma or a dural puncture. SIH is caused by a spontaneous spinal cerebrospinal fluid (CSF) leakage demonstrated by neuroradiological studies in most of the patients. Conservative treatment usually includes bed rest, hydration and administration of caffeine or steroids. However, when the patient is refractory to the conservative treatment, an epidural blood patch (EBP) is performed. We report a 34-year-old woman with SIH and no neuroradiologically demonstrable clear point of CSF leakage, who was treated with a double EBP at two different levels (lumbar and thoracic) in the same procedure. The patient was successfully managed, and she was still asymptomatic at the 18 months follow-up. After review of literature, we observed that execution of a double EBP at the same time is not a common procedure for treatment of SIH. We consider that simultaneous use of two EBP could be useful as a novel treatment in those cases of SIH without demonstration of CSF leakage.


Assuntos
Placa de Sangue Epidural/métodos , Hipotensão Intracraniana/terapia , Adulto , Anestesia Epidural , Vazamento de Líquido Cefalorraquidiano , Rinorreia de Líquido Cefalorraquidiano , Espaço Epidural/patologia , Feminino , Cefaleia/etiologia , Humanos , Imageamento por Ressonância Magnética
10.
Int J Clin Pract ; 66(3): 305-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22340450

RESUMO

INTRODUCTION: To evaluate the efficacy of Daptomycin (DPT) lock therapy in the treatment of Grampositive long-term catheter-related bloodstream infections (LT-CRBI). PATIENTS AND METHODS: A retrospective review of all patients receiving DPT lock therapy for the treatment of LT-CRBI from December 2009 to May 2010 was conducted. The primary endpoint used in this study was failure to cure the episode of LT-CRBI. Cure was defined as fever disappearance, negative blood cultures within 1 month after the end of treatment, and catheter salvage. RESULTS: Thirteen subjects (seven men, mean age 62 years) were evaluated. There were six Staphylococcus epidermidis, two Staphylococcus hominis, one Staphylococcus haemolyticus, two Enterococcus faecalis and two polymicrobial (S. epidermidis and S. hominis) bloodstream infections. DPT lock therapy was administered for a mean of 14 days (interquartilic range 10-14). Intravenous DPT was administered in nine patients for a mean of 10 days (interquartilic range 5-11). Clinical cure and blood culture sterilisation occurred in 11 of 13 patients (85%). Two patients had fever during treatment and catheters were removed. Median length of follow-up in patients with therapeutic success was 67 days (interquartilic range 14-88). CONCLUSION: DPT lock therapy demonstrated good in vivo efficacy in LT-CRBI caused by coagulase negative staphylococci and Enterococcus species.


Assuntos
Antibacterianos/administração & dosagem , Bacteriemia/tratamento farmacológico , Infecções Relacionadas a Cateter/tratamento farmacológico , Cateteres de Demora/efeitos adversos , Daptomicina/administração & dosagem , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Idoso , Infecções Relacionadas a Cateter/prevenção & controle , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
11.
Semergen ; 47(6): 411-425, 2021 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-34332864

RESUMO

Community-acquired pneumonia (CAP) continues to be an important cause of morbidity and mortality in adults. The aim of this study is to update the practical prevention guide for CAP through vaccination in Spain developed in 2016 and updated in 2018, based on available vaccines and evidence through bibliographic review and expert opinion. The arrival of COVID-19 as a new cause of CAP and the recent availability of safe and effective vaccines constitutes the most significant change. Vaccines against pneumococcus, influenza, pertussis and COVID-19 can help to reduce the burden of disease from CAP and its associated complications. The available evidence supports the priority indications established in this guide, and it would be advisable to try to achieve a widespread dissemination and implementation of these recommendations in routine clinical practice.


Assuntos
COVID-19 , Infecções Comunitárias Adquiridas , Pneumonia Pneumocócica , Adulto , Infecções Comunitárias Adquiridas/prevenção & controle , Humanos , Vacinas Pneumocócicas , Pneumonia Pneumocócica/prevenção & controle , SARS-CoV-2 , Vacinação
13.
Clin Microbiol Infect ; 26(6): 753-759, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31756452

RESUMO

OBJECTIVE: An early reduction of adult invasive pneumococcal disease (IPD) was observed after the 13-valent pneumococcal conjugate vaccine (PCV13) introduction for children in Spain. We analysed the epidemiology of adult IPD in the late-PCV13 period. METHODS: This was a prospective multicentre study of adult IPD involving six hospitals. Strains were serotyped, genotyped and studied for antimicrobial susceptibility. The late-PCV13 period was compared with the pre- and early-PCV13 periods. RESULTS: A total of 2197 episodes were collected-949 in 2008-2009, 609 in 2012-2013 and 639 in 2015-2016. The initial decrease of IPD observed (from 12.3/100 000 to 8.1/100 000; 2008-2009 versus 2012-2013) plateaued in 2015-2016 (8.3/100 000). IPD due to PCV13 serotypes decreased (from 7.7 to 3.5 to 2.3/100 000; p < 0.05), whereas IPD caused by non-PCV13 serotypes increased (from 4.5 to 4.6 to 6.0/100 000; p < 0.05). The most frequent serotypes in the late-PCV13 period were: 8 (15.1%), 3 (10.5%), 12F (7.9%) and 9N (5.4%). These serotypes were related to major genotypes: CC53 (59.8%) and CC404 (30.4%) for serotype 8, CC180 (64.1%) and CC260 (28.1%) for serotype 3, CC989 (91.7%) for serotype 12F and CC67 (84.8%) for serotype 9N. Penicillin-non-susceptibility (21.2%) was associated with serotypes 11A (CC156), 14 (CC156) and 19A (CC320), and macrolide-resistance was related to serotypes 24F and 19A. Rates of pneumococcal meningitis remained stable throughout the periods (ranges 0.9, 0.8 and 1.0/100 000). CONCLUSIONS: The initial decrease of adult IPD observed after PCV13 introduction for children has been balanced by the rise of non-PCV13 serotypes. The spread of antibiotic-resistant lineages related to non-PCV13 serotypes (11A and 24F) could be a threat for the treatment of serious pneumococcal diseases.


Assuntos
Infecções Pneumocócicas/epidemiologia , Streptococcus pneumoniae/classificação , Adolescente , Adulto , Idoso , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Genótipo , Hospitais/estatística & dados numéricos , Humanos , Pessoa de Meia-Idade , Vacinas Pneumocócicas , Estudos Prospectivos , Sorogrupo , Sorotipagem , Espanha/epidemiologia , Streptococcus pneumoniae/efeitos dos fármacos , Adulto Jovem
14.
Int J Food Microbiol ; 289: 209-214, 2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30384192

RESUMO

The presence of biofilms in food industrial environments is one of the main causes associated with food product contamination by L. monocytogenes. Biofilm control in the food industry is very relevant to public health and finding reliable and realistic quantification methods is essential. The aim of this study is to compare five L. monocytogenes biofilm quantification methods - conventional plate count, TEMPO, DEM, VIDAS and qPCR - and to examine a biodetector to visually detect biofilms in industrial settings. Results show that depending on the biofilm matrix production, the recovery of cells that conform the biofilm can be low and therefore, if it is an indirect method, microbial counts can be underestimated. At a species level, the methods that did not present significant differences were plate count, TEMPO (P = 0.998), DEM and qPCR (P = 0.508), so correlation studies were performed which established high correlation for plate count and TEMPO, but not for DEM and qPCR. The VIDAS method was adjusted so that it could quantify the biofilms, but the standard curve only allowed counts from 7 Log CFU cm-2. Results also revealed that the different strains of L. monocytogenes possess different biofilm-forming abilities, although it was not possible to correlate the capacity to produce these structures with the distinct serotypes. Last, visually detecting biofilms on stainless steel coupons proved that in industrial environments nowadays they can be rapidly and qualitatively detected so that relevant decisions can immediately be taken.


Assuntos
Biofilmes , Contagem de Colônia Microbiana/métodos , Indústria de Processamento de Alimentos/métodos , Listeria monocytogenes/fisiologia , Técnicas In Vitro , Aço Inoxidável
15.
Clin Exp Immunol ; 151(1): 51-60, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17983446

RESUMO

The molecular and functional characteristics of natural antibody from the preimmune repertoire have not been explored in detail in man. We describe seven human IgM monoclonal antibodies selected on the basis of pneumococcal polysaccharide binding that share both molecular and functional characteristics with natural antibody, suggesting a common B cell lineage origin. Unlike class-switched antibodies, which are serotype-specific, the antibodies were polyreactive and bound all pneumococcal polysaccharide capsular serotypes tested. Some bound endogenous antigens, including blood group antigens and intermediate filament proteins. All the antibodies used unmutated heavy chain V (IGHV) that are expressed at an increased frequency in the elderly and in the preimmune repertoire. The CDR3 was characterized by long length (mean aa 18.4 (+/-4.2) and selective use of IGHD6 (P < 0.001) and IGHJ6 (P < 0.01) family genes. The clones expressing IGHV1-69 and IGHV 3-21 provided significant passive protection against invasive pneumococcal disease in vivo.


Assuntos
Anticorpos Antibacterianos/genética , Anticorpos Antibacterianos/imunologia , Infecções Pneumocócicas/imunologia , Vacinas Pneumocócicas/administração & dosagem , Streptococcus pneumoniae/imunologia , Animais , Afinidade de Anticorpos , Especificidade de Anticorpos , Reações Antígeno-Anticorpo , Autoantígenos/imunologia , Sequência de Bases , Distribuição de Qui-Quadrado , Reações Cruzadas , Genes de Imunoglobulinas , Humanos , Hibridomas , Cadeias Pesadas de Imunoglobulinas , Imunoglobulina M/imunologia , Região Variável de Imunoglobulina/genética , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Semergen ; 44(8): 590-597, 2018.
Artigo em Espanhol | MEDLINE | ID: mdl-30318406

RESUMO

Community-acquired pneumonia (CAP) continues to be an important cause of morbidity and mortality in adults. The aim of this study is to update the 2016 practical prevention guidelines for CAP through vaccination in Spain, based on the available vaccines, as well as the evidence using a literature review and expert opinion. Vaccines against pneumococcus and influenza continue to be the main prevention tools available against CAP, and can contribute to reduce the burden of disease due to CAP and its associated complications. The available evidence supports the priority indications established in these guidelines, and it would be advisable to try to achieve a widespread dissemination and implementation of these recommendations in routine clinical practice.


Assuntos
Vacinas contra Influenza/administração & dosagem , Vacinas Pneumocócicas/administração & dosagem , Pneumonia Pneumocócica/prevenção & controle , Adulto , Infecções Comunitárias Adquiridas/prevenção & controle , Humanos , Influenza Humana/prevenção & controle , Pneumonia Pneumocócica/epidemiologia , Guias de Prática Clínica como Assunto , Espanha
17.
An Sist Sanit Navar ; 29 Suppl 2: 175-205, 2006.
Artigo em Espanhol | MEDLINE | ID: mdl-16998526

RESUMO

Organ transplantation has become one of the most important areas of medical research and, at present, is still the only therapeutical tool for several diseases. However, there are a number of factors related to transplantation, like immunosuppression and prolonged neutropenia that affect the incidence of infection. These infections are somehow peculiar to transplant recipients. In fact, there are infectious diseases that only occur in immunodepression situations and, moreover, clinical expression of these infectious diseases can be quite different from that in immunocompetent patients. Besides these aspects, some infections, due to the high prevalence described, must be considered for prevention strategies because they continue to be a principal cause of morbidity and mortality, either due to direct effects or to their implication in the pathogenesis of rejection. These strategies commence before transplantation by active immunization through vaccine administration to the patient and to people in the milieu and continue after transplantation with prophylaxis or pre-emptive therapy. The importance of infectious diseases in the evolution and prognosis of transplant recipients gives a special meaning to the understanding of associated infections, their clinical expression and ways of prevention and treatment.


Assuntos
Infecções/etiologia , Transplante de Órgãos , Transplante de Células-Tronco , Transplante de Coração , Transplante de Coração-Pulmão , Humanos , Imunocompetência , Hospedeiro Imunocomprometido , Infecções/tratamento farmacológico , Infecções/transmissão , Intestino Delgado/transplante , Transplante de Rim , Transplante de Pulmão , Transplante de Órgãos/efeitos adversos , Transplante de Órgãos/mortalidade , Transplante de Pâncreas , Fatores de Risco , Transplante de Células-Tronco/mortalidade
18.
Tree Physiol ; 25(6): 701-12, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15805090

RESUMO

Standing biomass, net primary production (NPP) and soil carbon (C) pools were studied in a 67-year-old pedunculate oak (Quercus robur L.) stand and a neighboring 74-year- old Scots pine (Pinus sylvestris L.) stand in the Belgian Campine region. Despite a 14% lower tree density and a lower tree height in the oak stand, standing biomass was slightly higher than in the pine stand (177 and 169 Mg ha(-1) in oaks and pines, respectively), indicating that individual oak trees contained more biomass than pine trees of similar diameter. Moreover, NPP in the oak stand was more than double that in the pine stand (17.7 and 8.1 Mg ha(-1) year(-1), respectively). Several observations indicated that soil organic matter accumulated at higher rates under pines than under oaks. We therefore hypothesized that the pines were exhibiting an age-related decline in productivity due to nutrient limitation. The poor decomposability of pine litter resulted in the observed accumulation of organic matter. The subsequent immobilization of nutrients in the organic matter, combined with the already nutrient-poor soil conditions, resulted in a decrease in total NPP over time, as well as in a substantial shift in the allocation of NPP toward fine roots. In the oak stand, litter is less recalcitrant to decay and soil acidity is less severe; hence, organic matter does not accumulate and nutrients are recycled. This probably explains why NPP was much higher in the oaks than in the pines and why only a small proportion of NPP was allocated to oak fine roots.


Assuntos
Carbono/metabolismo , Pinus/metabolismo , Quercus/metabolismo , Biomassa , Carbono/análise , Nitrogênio/análise , Pinus/anatomia & histologia , Pinus/crescimento & desenvolvimento , Quercus/anatomia & histologia , Quercus/crescimento & desenvolvimento , Solo
19.
Tree Physiol ; 25(5): 609-19, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15741145

RESUMO

Soil respiration (SR) was measured with an infrared gas analyzer in nine plots representative of the heterogeneous vegetation in a mixed coniferous-deciduous forest in the Belgian Campine region. Selected plots included the two most representative overstory species (Pinus sylvestris L. and Quercus robur L.) in combination with the most representative understory species of the forest. A model that includes temperature and water as the main controlling variables was fitted to the data. We found large spatial variability in SR among plots, with typically lower fluxes under the coniferous overstory than under the deciduous overstory (means of 4.8 +/- 0.4 and 8.8 +/- 0.5 Mg C ha(-1) year(-1), respectively). Total annual soil carbon (C) emissions were estimated by weighting fluxes from different types of vegetation according to their relative contribution to the footprint area of the eddy covariance flux measurement. The relative contribution of the two main tree species to the footprint-weighted total SR varied among seasons with the more abundant coniferous overstory contributing the most to total SR during most of the year. Nonetheless, during summer, the contribution of deciduous plots to total SR was disproportionally high because of the more pronounced seasonality of belowground metabolic activity. Net ecosystem carbon dioxide exchange was measured by eddy covariance, and we estimated total ecosystem respiration (TER) with footprint-constrained nighttime fluxes. Mean total annual SR and TER were 6.1 +/- 0.11 and 9.1 +/- 1.15 Mg C ha(-1) year(-1), respectively. The 95% confidence interval of the ratio of annual SR:TER ranged from 0.58 to 0.76, with a mean of 0.67. The contribution of SR to TER tended to vary seasonally, with minimum contributions during summer (less than 50% of TER) and maximum contributions during winter (about 94% of TER).


Assuntos
Dióxido de Carbono/metabolismo , Ecossistema , Solo , Árvores/metabolismo , Fatores de Tempo
20.
Tree Physiol ; 23(18): 1263-70, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14652226

RESUMO

Soil respiration (SR) was monitored periodically throughout 2001 in a Scots pine (Pinus sylvestris L.) stand located in the Belgian Campine region. As expected for a temperate maritime forest, temperature was the dominant control over SR during most of the year. However, during late spring and summer, when soil water content (SWC) was limiting, SR was insensitive to temperature (Q(10) = 1.24). We observed that during prolonged rain-free periods, when SWC was less than 15% (v/v), SR decreased dramatically (up to 50%) and SWC took over control of SR. During such drought periods, however, rain events sometimes stimulated SR and restored temperature control over SR, even though SWC in the mineral soil was low. We hypothesize that restoration of temperature control occurred only when rain events adequately rewetted the uppermost soil layers, where most of the respiratory activity occurred. To quantify the rewetting capacity of rain events, an index (I(w)) was designed that incorporated rainfall intensity, time elapsed since the last rain event, and atmospheric vapor pressure deficit (a proxy for evaporative water losses). To simulate SR fluxes, a model was developed that included the effects of soil temperature and, under drought and non-rewetting conditions (I(w) and SWC < threshold), an SWC response function. The model explained 95% of the temporal variability in SR observed during summer, whereas the temperature function alone explained only 73% of this variability. Our results revealed that, in addition to temperature and SWC, rain plays a role in determining the total amount of carbon released from soils, even in a maritime climate.


Assuntos
Pinus/fisiologia , Solo , Árvores/fisiologia , Respiração Celular/fisiologia , Ecossistema , Chuva , Temperatura
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