RESUMO
BACKGROUND: Thoracoabdominal normothermic regional perfusion (TA-NRP) has emerged as a powerful technique for optimizing organ procurement from donation after circulatory death donors. Despite its rapid adoption, standardized guidelines for TA-NRP implementation are lacking, prompting the need for consensus recommendations to ensure safe and effective utilization of this technique. METHODS: A working group composed of members from The American Society of Transplant Surgeons, The International Society of Heart and Lung Transplantation, The Society of Thoracic Surgeons, and The American Association for Thoracic Surgery was convened to develop technical guidelines for TA-NRP. The group systematically reviewed existing literature, consensus statements, and expert opinions to identify key areas requiring standardization, including predonation evaluation, intraoperative management, postdonation procedures, and future research directions. RESULTS: The working group formulated recommendations encompassing donor evaluation and selection criteria, premortem testing and therapeutic interventions, communication protocols, and procedural guidelines for TA-NRP implementation. These recommendations aim to facilitate coordination among transplant teams, minimize variability in practice, and promote transparency and accountability throughout the TA-NRP process. CONCLUSIONS: The consensus guidelines presented herein serve as a comprehensive framework for the successful and ethical implementation of TA-NRP programs in organ procurement from donation after circulatory death donors. By providing standardized recommendations and addressing areas of uncertainty, these guidelines aim to enhance the quality, safety, and efficiency of TA-NRP procedures, ultimately contributing to improved outcomes for transplant recipients.
Assuntos
Consenso , Preservação de Órgãos , Perfusão , Humanos , Perfusão/normas , Perfusão/métodos , Preservação de Órgãos/normas , Preservação de Órgãos/métodos , Doadores de Tecidos/provisão & distribuição , Transplante de Órgãos/normas , Transplante de Órgãos/métodos , Seleção do Doador/normas , Obtenção de Tecidos e Órgãos/normas , Obtenção de Tecidos e Órgãos/métodosRESUMO
PURPOSE: Hospitalized patients receive potassium (K+) supplementation for hypokalemia, with clinicians often estimating a rise in serum K+ levels of 0.1 mEq/L per 10 mEq delivered. However, there is limited evidence to support this expectation. Patients also concomitantly take medications that may alter K+ levels, and it is not known to what degree these may impact interventions to correct K+ levels via supplementation. The objective of this study was to identify the impact of oral and/or intravenous K+ supplementation on serum K+ levels, including the influence of selected concomitant medications, in adult hospitalized patients. METHODS: A single-center, retrospective descriptive study of adult hospitalized patients receiving K+ supplementation at a tertiary hospital between 2021 and 2022 was conducted. Patients were included if they received at least one dose of potassium chloride while admitted to the general medicine ward. The primary outcome was the daily median change in serum K+, normalized per 10 mEq of supplementation administered. The secondary outcome was the impact of selected concomitant medication use on supplement-induced changes in serum K+. RESULTS: A total of 800 patients and 1,291 daily episodes of K+ supplementation were evaluated. The sample was approximately 53% women, was 78% white, and had a median age of 68 years. The overall daily median change in serum K+ level was 0.05 mEq/L per 10 mEq of supplementation delivered. Patients received a median of 40 mEq of supplementation per day, primarily via the oral route (80.6%). Among the concomitant medications assessed, loop diuretics significantly dampened the impact of K+ supplementation. CONCLUSION: Supplementation of K+ in non-critically ill hospitalized patients is variable and dependent on concomitant medication use.
Assuntos
Suplementos Nutricionais , Potássio , Adulto , Humanos , Feminino , Idoso , Masculino , Estudos Retrospectivos , Cloreto de Potássio/uso terapêutico , HomeostaseRESUMO
PURPOSE: Ligament repair with suture-tape augmentation has been used in the operative treatment of joint instability and may have advantages with respect to early motion and stability. The purpose of this investigation was to describe the clinical results of traumatic elbow instability treated with lateral ulnar collateral ligament repair with suture-tape augmentation. METHODS: All cases of acute and chronic elbow instability treated surgically between 2018 and 2020 were included if they underwent ligament repair with suture-tape augmentation of the lateral ulnar collateral ligament as part of the procedure. Cases with <6 months of follow-up were excluded. A manual chart review was performed to record patient demographics as well as injury and surgery characteristics. Radiographic outcomes, range of motion, and patient-reported outcome measures, including the visual analog pain scale and Disabilities of the Arm, Shoulder, and Hand, were recorded. Range of motion measurements were recorded at the end of the clinical follow-up, as were surgical complications. RESULTS: Eighteen cases were included with a mean follow-up of 20 months. Five (28%) cases involved a high-energy mechanism, and 11 (62%) cases involved terrible triad fracture dislocations. The mean Disabilities of the Arm, Shoulder, and Hand questionnaire and visual analog pain scale scores were 17 and 2, respectively. The mean flexion-extension arc was 124°, and 2 (11%) cases had <100° flexion-extension arc. There were 2 (11%) postoperative complications, and both cases had postoperative instability requiring reoperation. We observed no cases of capitellar erosion from the suture-tape material. CONCLUSIONS: For complex elbow instability, ligament repair with suture-tape augmentation of the lateral ulnar collateral ligament results in acceptable functional outcomes and a reoperation rate comparable with other joint stabilization procedures. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.
Assuntos
Ligamento Colateral Ulnar , Ligamentos Colaterais , Lesões no Cotovelo , Articulação do Cotovelo , Instabilidade Articular , Humanos , Cotovelo , Articulação do Cotovelo/cirurgia , Ligamento Colateral Ulnar/cirurgia , Ligamento Colateral Ulnar/lesões , Instabilidade Articular/cirurgia , Resultado do Tratamento , Suturas , Ligamentos Colaterais/lesões , Amplitude de Movimento ArticularRESUMO
In Brazil, prevalence of diagnosed COPD among adults aged 40 years and over is 16% although over 70% of cases remain undiagnosed. Hypertension is common and well-recorded in primary care, and frequently co-exists with COPD because of common causes such as tobacco smoking, therefore we conducted a cross-sectional screening test accuracy study in nine Basic Health Units in Brazil, among hypertensive patients aged ≥40 years to identify the optimum screening test/combinations to detect undiagnosed COPD. We compared six index tests (four screening questionnaires, microspirometer and peak flow) against the reference test defined as those below the lower limit of normal (LLN-GLI) on quality diagnostic spirometry, with confirmed COPD at clinical review. Of 1162 participants, 6.8% (n = 79) had clinically confirmed COPD. Peak flow had a higher specificity but lower sensitivity than microspirometry (sensitivity 44.3% [95% CI 33.1, 55.9], specificity 95.5% [95% CI 94.1, 96.6]). SBQ performed well compared to the other questionnaires (sensitivity 75.9% [95% CI 65.0, 84.9], specificity 59.2% [95% CI 56.2, 62.1]). A strategy requiring both SBQ and peak flow to be positive yielded sensitivity of 39.2% (95% CI 28.4, 50.9) and specificity of 97.0% (95% CI 95.7, 97.9). The use of simple screening tests was feasible within the Brazilian primary care setting. The combination of SBQ and peak flow appeared most efficient, when considering performance of the test, cost and ease of use (costing £1690 (5554 R$) with 26.7 cases detected per 1,000 patients). However, the choice of screening tests depends on the clinical setting and availability of resources.ISRCTN registration number: 11377960.
Assuntos
Hipertensão , Doença Pulmonar Obstrutiva Crônica , Adulto , Humanos , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Brasil , Estudos Transversais , Análise Custo-Benefício , Espirometria , Inquéritos e Questionários , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Hipertensão/complicações , Programas de RastreamentoRESUMO
Purpose: As many as one-third of patients with heart failure secondary to systemic, wild-type transthyretin amyloidosis have an associated distal biceps tendon (DBT) rupture. Our purpose was to identify the prevalence of amyloid deposition in patients undergoing operative repair of acute traumatic DBT ruptures. Methods: In this prospective investigation, a consecutive series of patients who underwent repair of an acute traumatic DBT rupture underwent a tendon biopsy to assess for amyloid deposition. All specimens were viewed under gross microscopy by a board-certified pathologist. For initial screening, either Congo red or Thioflavin-T immunohistochemistry analysis was conducted to determine amyloid status. If staining was positive for amyloid deposition using either technique, the tissue sample was sent to an outside facility for specific amyloid protein identification through liquid chromatography-tandem mass spectrometry. Baseline demographics were also recorded for each patient. Results: A total of 30 patients who underwent biopsy and repair of an acute DBT rupture were included. The mean age was 48 years, and all patients were men. Seven (23%) patients had a history of carpal tunnel syndrome, and 1 (3%) patient had evidence of heart failure at the time of surgery. One (3%) patient had evidence of amyloid deposition in the DBT, which was confirmed using liquid chromatography-tandem mass spectrometry. Conclusions: Although one-third of patients with heart failure secondary to cardiac amyloidosis have an associated DBT rupture, younger patients with acute traumatic DBT ruptures do not appear to be uniquely at risk for amyloid deposition at the time of DBT repair. Larger registry studies may be necessary to define the risk of developing cardiac amyloidosis years after sustaining an acute DBT rupture. Type of study/level of evidence: Prognostic IV.
RESUMO
Replicated radiations, in which sets of similar forms evolve repeatedly within different regions, can provide powerful insights into parallel evolution and the assembly of functional diversity within communities. Several cases have been described in animals, but in plants we lack well-documented cases of replicated radiation that combine comprehensive phylogenetic and biogeographic analyses, the delimitation of geographic areas within which a set of 'ecomorphs' evolved independently and the identification of potential underlying mechanisms. Here we document the repeated evolution of a set of leaf ecomorphs in a group of neotropical plants. The Oreinotinus lineage within the angiosperm clade Viburnum spread from Mexico to Argentina through disjunct cloud forest environments. In 9 of 11 areas of endemism, species with similar sets of leaf forms evolved in parallel. We reject gene-flow-mediated evolution of similar leaves and show, instead, that species with disparate leaf forms differ in their climatic niches, supporting ecological adaptation as the driver of parallelism. Our identification of a case of replicated radiation in plants sets the stage for comparative analyses of such phenomena across the tree of life.
Assuntos
Florestas , Fluxo Gênico , Adaptação Fisiológica , Animais , México , FilogeniaRESUMO
PURPOSE: Xylazine is an alpha-2-adrenergic agonist used for its sedative and analgesic properties in veterinary medicine. While not approved by the Food and Drug Administration for use in humans, anecdotal evidence suggests that exposures in humans is on the rise. We sought to systematically review and synthesize the evidence on xylazine exposure in humans focusing on the clinical presentation, management, and outcomes. METHODS: We conducted a systematic review of the literature including PubMed, Embase, and Scopus from their inception to September 9, 2021. We searched abstracts from selected emergency medicine and toxicology conferences from 2011 through 2021. We included clinical reports of xylazine exposure in humans. We excluded animal studies, in vitro studies, laboratory studies, or articles in a language other than English. From each included article, we extracted subjective and objective data that focused on clinical presentation, management, and outcomes of patients exposed to xylazine. RESULTS: We evaluated a total of 1409 records, rendering a final set of 17 articles and 2 abstracts meeting inclusion criteria. We identified a total of 98 patients amongst reports ranging from 1979 to 2020 and across nine countries. The most common types of xylazine exposures reported were unintentional exposure and intentional misuse/abuse. Common symptoms on presentation included hypotension, bradycardia, drowsiness, lethargy, while apnea with intubation and death were less frequently reported. CONCLUSION: Human exposure to xylazine appears to be a rising concern within the prehospital and emergency medicine setting. Although a standardized treatment algorithm cannot be recommended at this time, further research is needed to improve the care of patients exposed to xylazine.
Assuntos
Hipotensão , Xilazina , Agonistas Adrenérgicos , Bradicardia , Humanos , Hipnóticos e Sedativos , Estados UnidosRESUMO
Central nervous system high-grade neuroepithelial tumor with MN1 alteration (CNS HGNET-MN1) is a rare recently described entity. Fourteen CNS HGNET-MN1 patients were identified using genome-wide methylation arrays/RT-PCR across seven institutions. All patients had surgery (gross total resection: 10; subtotal resection: four) as initial management followed by observation alone in three patients, followed by radiotherapy in eight patients (focal: five; craniospinal: two; CyberKnife: one) and systemic chemotherapy in three patients. Seven patients relapsed; five local and two metastatic, despite adjuvant radiotherapy, of which three died. Treatment of CNS HGNET-MN1 remains a major treatment challenge despite aggressive surgical resections and upfront radiotherapy, warranting new approaches to this rare malignancy.
Assuntos
Neoplasias do Sistema Nervoso Central/patologia , Mutação , Neoplasias Neuroepiteliomatosas/patologia , Transativadores/genética , Proteínas Supressoras de Tumor/genética , Adolescente , Adulto , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/terapia , Criança , Pré-Escolar , Terapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Neoplasias Neuroepiteliomatosas/genética , Neoplasias Neuroepiteliomatosas/terapia , Prognóstico , Estudos Retrospectivos , Adulto JovemRESUMO
Objective: We review prior studies on the incidence of hypertension (HTN) after earthquakes and present a retrospective analysis of HTN after the 2010 earthquake in Haiti. Methods: Prior reports on HTN incidence were reviewed and a retrospective chart review for diagnosis of HTN in 4,308 patient charts was performed over a 7 year period (five clinics). A retrospective cohort study (RCS) was then performed on 11 patients with linear follow-up. Results: The Literature review revealed a significant increase in acute and subacute HTN following earthquakes. However, the chronic effects of earthquakes varied. Our chart review uncovered no significant difference in diagnosed HTN in a Fort-Liberté clinic 128 kilometers (km) distant and 4 weeks post-event. A secondary linear RCS for 11 individuals, prior to and after the earthquake, also did not detect a significant change in HTN prevalence. Conclusion: Prior studies demonstrate acute and subacute, increases in HTN after earthquakes, but late changes have varied. Retrospective studies in the Fort-Liberté clinic, 128 km distant and 4 weeks post-event, revealed no significant change in HTN, confirming prior findings that changes in HTN after earthquakes are early and local events. Further work examining HTN after earthquakes is needed to improve early health care after natural disasters.
Assuntos
Desastres , Terremotos , Hipertensão , Pressão Sanguínea , Haiti/epidemiologia , Humanos , Hipertensão/epidemiologia , Estudos RetrospectivosRESUMO
Traumatic brain injury (TBI) is a major cause of chronic disability. Less than a quarter of moderate and severe TBI patients improved in their cognition within 5 years. Non-invasive brain stimulation, including transcranial direct current stimulation (tDCS), may help neurorehabilitation by boosting adaptive neuroplasticity and reducing pathological sequelae following TBI. METHODS: we searched MEDLINE/PubMed and Web of Science databases. We used Jadad scale to assess methodological assumptions. RESULTS: the 14 papers included reported different study designs; 2 studies were open-label, 9 were crossover randomized clinical trials (RCTs), and 3 were parallel group RCTs. Most studies used anodal tDCS of the left dorsolateral prefrontal cortex, but montages and stimulation parameters varied. Multiple studies showed improved coma recovery scales in disorders of consciousness, and improved cognition on neuropsychological assessments. Some studies showed changes in neurophysiologic measures (electroencephalography (EEG) and transcranial magnetic stimulation (TMS), correlating with clinical findings. The main methodological biases were lack of blinding and randomization reports. CONCLUSION: tDCS is a safe, non-invasive neuromodulatory technique that can be given as monotherapy but may be best combined with other therapeutic strategies (such as cognitive rehabilitation and physical therapy) to further improve clinical cognitive and motor outcomes. EEG and TMS may help guide research due to their roles as biomarkers for neuroplasticity.
A lesão cerebral traumática (TCE) é uma das principais causas de incapacidade crônica. Menos de um quarto dos pacientes com TCE moderada e grave melhoraram sua cognição dentro de cinco anos. A estimulação cerebral não invasiva, incluindo a estimulação transcraniana por corrente contínua (ETCC), pode ajudar na reabilitação neurológica, aumentando a neuroplasticidade adaptativa e reduzindo as sequelas patológicas após o TCE. MÉTODOS: pesquisamos os bancos de dados MEDLINE / PubMed e Web of Science. Usamos a escala de Jadad para avaliar os métodos utilizados nos ensaios clínicos. RESULTADOS: os 14 artigos incluídos relataram diferentes desenhos de estudo; 2 estudos foram abertos, 9 foram ensaios clínicos randomizados (ECRs) cruzados e 3 foram ECR de grupos paralelos. A maioria dos estudos utilizou a ETCC anódica do córtex pré-frontal dorsolateral esquerdo, mas os parâmetros de montagem e estimulação variaram. Múltiplos estudos mostraram melhoras nas escalas de recuperação de coma em pacientes com distúrbios da consciência e melhora da cognição. Alguns estudos mostraram alterações nas medidas neurofisiológicas (eletroencefalografia (EEG) e estimulação magnética transcraniana (EMT)), correlacionando com os achados clínicos. Os principais vieses metodológicos foram a falta de relatos de cegamento e randomização. CONCLUSÃO: a ETCC é uma técnica neuromodulatória segura e não invasiva que pode ser administrada em monoterapia, mas a utilização da ETCC parece impulsionar os resultados clínicos quando combinada com outras estratégias terapêuticas (como reabilitação cognitiva e fisioterapia). O EEG e o EMT podem ajudar a orientar a pesquisa e tambem mensurar os ganhos clínicos por serem potenciais biomarcadores da neuroplasticidade.
RESUMO
BACKGROUND: Chronic rhinosinusitis (CRS) is a significant manifestation of cystic fibrosis (CF) with wide-ranging symptom and disease severity. The goal of the study was to determine clinical variables that correlate with outcome measures of disease severity. METHODS: A prospective, longitudinal, observational study of 33 adults with symptomatic CRS treated in a CF-focused otolaryngology clinic was performed. Symptom severity, the presence of rhinosinusitis exacerbations, and endoscopic appearance were assessed, and regression analysis was used to determine clinical predictors of disease outcome. RESULTS: Thirty-three adults with CF-CRS were included in the study and followed for a mean of 15 months. Rhinosinusitis exacerbations occurred in 61% of participants during the study, and female sex increased the odds of presenting with an exacerbation visit. Sinus disease exacerbations were associated with an odds ratio of 2.07 for presenting with a pulmonary exacerbation at the next visit. CF-related diabetes was found to be associated with worse symptoms and endoscopic appearance. Infection with Staphylococcus aureus predicted worsening of symptoms, whereas infections with Pseudomonas aeruginosa improved over time. Allergic rhinitis was associated with worse endoscopic appearance, and nasal steroid use was associated with improved endoscopic appearance. CONCLUSION: Sex, CF-related diabetes, sinonasal infection status, allergic rhinitis, and nasal steroid use may all modulate severity of CF-CRS in adults. Sinusitis exacerbation may be a precursor to pulmonary exacerbation.
Assuntos
Fibrose Cística , Rinite , Sinusite , Adulto , Antibacterianos/uso terapêutico , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/fisiopatologia , Infecções Bacterianas/terapia , Doença Crônica , Fibrose Cística/diagnóstico , Fibrose Cística/fisiopatologia , Fibrose Cística/terapia , Endoscopia , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Lavagem Nasal , Rinite/diagnóstico , Rinite/fisiopatologia , Rinite/terapia , Índice de Gravidade de Doença , Fatores Sexuais , Sinusite/diagnóstico , Sinusite/fisiopatologia , Sinusite/terapia , Esteroides/uso terapêuticoRESUMO
ABSTRACT. Traumatic brain injury (TBI) is a major cause of chronic disability. Less than a quarter of moderate and severe TBI patients improved in their cognition within 5 years. Non-invasive brain stimulation, including transcranial direct current stimulation (tDCS), may help neurorehabilitation by boosting adaptive neuroplasticity and reducing pathological sequelae following TBI. Methods: we searched MEDLINE/PubMed and Web of Science databases. We used Jadad scale to assess methodological assumptions. Results: the 14 papers included reported different study designs; 2 studies were open-label, 9 were crossover randomized clinical trials (RCTs), and 3 were parallel group RCTs. Most studies used anodal tDCS of the left dorsolateral prefrontal cortex, but montages and stimulation parameters varied. Multiple studies showed improved coma recovery scales in disorders of consciousness, and improved cognition on neuropsychological assessments. Some studies showed changes in neurophysiologic measures (electroencephalography (EEG) and transcranial magnetic stimulation (TMS), correlating with clinical findings. The main methodological biases were lack of blinding and randomization reports. Conclusion: tDCS is a safe, non-invasive neuromodulatory technique that can be given as monotherapy but may be best combined with other therapeutic strategies (such as cognitive rehabilitation and physical therapy) to further improve clinical cognitive and motor outcomes. EEG and TMS may help guide research due to their roles as biomarkers for neuroplasticity.
RESUMO. A lesão cerebral traumática (TCE) é uma das principais causas de incapacidade crônica. Menos de um quarto dos pacientes com TCE moderada e grave melhoraram sua cognição dentro de cinco anos. A estimulação cerebral não invasiva, incluindo a estimulação transcraniana por corrente contínua (ETCC), pode ajudar na reabilitação neurológica, aumentando a neuroplasticidade adaptativa e reduzindo as sequelas patológicas após o TCE. Métodos: pesquisamos os bancos de dados MEDLINE / PubMed e Web of Science. Usamos a escala de Jadad para avaliar os métodos utilizados nos ensaios clínicos. Resultados: os 14 artigos incluídos relataram diferentes desenhos de estudo; 2 estudos foram abertos, 9 foram ensaios clínicos randomizados (ECRs) cruzados e 3 foram ECR de grupos paralelos. A maioria dos estudos utilizou a ETCC anódica do córtex pré-frontal dorsolateral esquerdo, mas os parâmetros de montagem e estimulação variaram. Múltiplos estudos mostraram melhoras nas escalas de recuperação de coma em pacientes com distúrbios da consciência e melhora da cognição. Alguns estudos mostraram alterações nas medidas neurofisiológicas (eletroencefalografia (EEG) e estimulação magnética transcraniana (EMT)), correlacionando com os achados clínicos. Os principais vieses metodológicos foram a falta de relatos de cegamento e randomização. Conclusão: a ETCC é uma técnica neuromodulatória segura e não invasiva que pode ser administrada em monoterapia, mas a utilização da ETCC parece impulsionar os resultados clínicos quando combinada com outras estratégias terapêuticas (como reabilitação cognitiva e fisioterapia). O EEG e o EMT podem ajudar a orientar a pesquisa e tambem mensurar os ganhos clínicos por serem potenciais biomarcadores da neuroplasticidade.
Assuntos
Humanos , Reabilitação , Estimulação Transcraniana por Corrente Contínua , Lesões Encefálicas Traumáticas , Plasticidade NeuronalRESUMO
INTRODUCTION: Cell plasticity is crucial in cloning to allow an efficient nuclear reprogramming and healthy offspring. Hence, cells with high plasticity, such as multipotent mesenchymal stem cells (MSCs), may be a promising alternative for horse cloning. In this study, we evaluated the use of bone marrow-MSCs (BM-MSCs) as nuclear donors in horse cloning, and we compared the in vitro and in vivo embryo development with respect to fibroblasts. MATERIALS AND METHODS: Zona-free nuclear transfer was performed using BM-MSCs (MSC group, n=3432) or adult fibroblasts (AF group, n=4527). Embryos produced by artificial insemination (AI) recovered by uterine flushing and transferred to recipient mares were used as controls (AI group). RESULTS: Blastocyst development was higher in the MSC group than in the AF group (18.1% vs 10.9%, respectively; p<0.05). However, pregnancy rates and delivery rates were similar in both cloning groups, although they were lower than in the AI group (pregnancy rates: 17.7% [41/232] for MSC, 12.5% [37/297] for AF and 80.7% [71/88] for AI; delivery rates: 56.8% [21/37], 41.5% [17/41] and 90.1% [64/71], respectively). Remarkably, the gestation length of the AF group was significantly longer than the control (361.7±10.9 vs 333.9±8.7 days), in contrast to the MSC group (340.6±8.89 days). Of the total deliveries, 95.2% (20/21) of the MSC-foals were viable, compared to 52.9% (9/17) of the AF-foals (p<0.05). In addition, the AF-foals had more physiological abnormalities at birth than the MSC-foals; 90.5% (19/21) of the MSC-delivered foals were completely normal and healthy, compared to 35.3% (6/17) in the AF group. The abnormalities included flexural or angular limb deformities, umbilical cord enlargement, placental alterations and signs of syndrome of neonatal maladjustment, which were treated in most cases. CONCLUSION: In summary, we obtained 29 viable cloned foals and found that MSCs are suitable donor cells in horse cloning. Even more, these cells could be more efficiently reprogrammed compared to fibroblasts.
RESUMO
We present a meta-analysis of plant responses to fertilization experiments conducted in lowland, species-rich, tropical forests. We also update a key result and present the first species-level analyses of tree growth rates for a 15-yr factorial nitrogen (N), phosphorus (P), and potassium (K) experiment conducted in central Panama. The update concerns community-level tree growth rates, which responded significantly to the addition of N and K together after 10 yr of fertilization but not after 15 yr. Our experimental soils are infertile for the region, and species whose regional distributions are strongly associated with low soil P availability dominate the local tree flora. Under these circumstances, we expect muted responses to fertilization, and we predicted species associated with low-P soils would respond most slowly. The data did not support this prediction, species-level tree growth responses to P addition were unrelated to species-level soil P associations. The meta-analysis demonstrated that nutrient limitation is widespread in lowland tropical forests and evaluated two directional hypotheses concerning plant responses to N addition and to P addition. The meta-analysis supported the hypothesis that tree (or biomass) growth rate responses to fertilization are weaker in old growth forests and stronger in secondary forests, where rapid biomass accumulation provides a nutrient sink. The meta-analysis found no support for the long-standing hypothesis that plant responses are stronger for P addition and weaker for N addition. We do not advocate discarding the latter hypothesis. There are only 14 fertilization experiments from lowland, species-rich, tropical forests, 13 of the 14 experiments added nutrients for five or fewer years, and responses vary widely among experiments. Potential fertilization responses should be muted when the species present are well adapted to nutrient-poor soils, as is the case in our experiment, and when pest pressure increases with fertilization, as it does in our experiment. The statistical power and especially the duration of fertilization experiments conducted in old growth, tropical forests might be insufficient to detect the slow, modest growth responses that are to be expected.
Assuntos
Florestas , Clima Tropical , Nitrogênio , Panamá , Fósforo , Solo , ÁrvoresRESUMO
Nitrogen (N) availability influences the productivity and distribution of plants in tropical montane forests. Strategies to acquire soil N, such as direct uptake of organic compounds or associations with root symbionts to enhance N acquisition in exchange for carbon (C), may facilitate plant species coexistence and ecosystem N retention. Alternatively, rapid microbial turnover of soil N forms in tropical soils might promote flexible plant N-uptake strategies and mediate species coexistence. We tested whether sympatric plant species with different root symbiont associations, and therefore potentially different nutrient acquisition strategies, partition chemical forms of N or show plasticity in N uptake in a tropical pre-montane forest in Panama. We traced the movement of three 15 N forms into soil pools, microbes, and seedlings of eleven species differing in root traits. Seedlings were grown in a split-plot field transplant experiment, with plots receiving equimolar mixtures of ammonium, nitrate, and glycine, with one form isotopically labeled in each block. After 48 h, more 15 N was recovered in microbes than in plants, while all pools (extractable organic and inorganic N, microbial biomass, and leaves) contained greater amounts of 15 N from nitrate than from ammonium or glycine. Furthermore, 13 C from dual-labeled glycine was not recovered in the leaves of any seedling, suggesting the studied species do not directly take up organic N or transform organic N prior to translocation to leaves. Nitrogen uptake differed by root symbiont group only for nitrate, with greater 15 N recovery in plants with arbuscular mycorrhizal (AM) associations or proteoid roots compared to orchids. Some root trait groups differed in 15 N recovery among N forms, with greater nitrate uptake than ammonium or glycine by AM-associated and N2 -fixing plants. However, only five of eleven species showed differences in uptake among N forms. These results indicate flexibility in uptake of N forms in tropical plants across root trait groups, with only a few species displaying weak preferences for a specific N form.
Assuntos
Florestas , Nitrogênio/metabolismo , Plantas/metabolismo , Panamá , Raízes de Plantas , SoloRESUMO
Boletellus exiguus sp. nov. and Boletellus dicymbophilus sp. nov. (Boletaceae, Boletales, Basidiomycota) are described as new to science. These boletes were collected from tropical forests dominated by ectomycorrhizal Dicymbe corymbosa (Caesalpiniaceae) in the Pakaraima Mountains of western Guyana.
Assuntos
Basidiomycota/classificação , Basidiomycota/isolamento & purificação , Fabaceae/microbiologia , Basidiomycota/citologia , Guiana , Microscopia , Esporos Fúngicos/citologia , Árvores , Clima TropicalRESUMO
An HIV-1-infected patient with progressive multifocal leukoencephalopathy presented clinical deterioration and contrast-enhancing lesions on brain nuclear MR after the initiation of highly active antiretroviral therapy (HAART). Brain biopsy identified an inflammatory reaction compatible with immune reconstitution inflammatory syndrome. Treatment with corticosteroids and transient suppression of HAART led to marked neurologic improvement.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Terapia Antirretroviral de Alta Atividade/efeitos adversos , Encéfalo/efeitos dos fármacos , Encefalite/induzido quimicamente , Encefalite/imunologia , Leucoencefalopatia Multifocal Progressiva/tratamento farmacológico , Adulto , Anti-Inflamatórios/uso terapêutico , Afasia/induzido quimicamente , Afasia/imunologia , Afasia/fisiopatologia , Encéfalo/imunologia , Encéfalo/patologia , Quimiotaxia de Leucócito/efeitos dos fármacos , Quimiotaxia de Leucócito/imunologia , Dexametasona/uso terapêutico , Encefalite/fisiopatologia , Hemiplegia/induzido quimicamente , Hemiplegia/imunologia , Hemiplegia/fisiopatologia , Humanos , Corpos de Inclusão/imunologia , Corpos de Inclusão/patologia , Corpos de Inclusão/virologia , Vírus JC/imunologia , Vírus JC/isolamento & purificação , Leucoencefalopatia Multifocal Progressiva/fisiopatologia , Leucoencefalopatia Multifocal Progressiva/virologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Imageamento por Ressonância Magnética , Masculino , Oligodendroglia/imunologia , Oligodendroglia/patologia , Oligodendroglia/virologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Resultado do Tratamento , Suspensão de TratamentoRESUMO
This work tested the hypothesis that ectomycorrhizas (EM) of Dicymbe corymbosa alter leaf-litter decomposition and residual litter quality in tropical forests of Guyana. Mass loss of leaf litter in litter bags was determined on three occasions, in two experiments, during a 12-month period. Paired root-exclusion plots were located randomly within a D. corymbosa forest. Both D. corymbosa and mixed-species leaf litters were reciprocally transplanted into their respective forest types. Elemental analysis was performed on the residual D. corymbosa leaf litter after 1 yr. Leaf litter mass loss in the D. corymbosa forest was not influenced by EM, despite high EM colonization. Elemental analysis of D. corymbosa leaf litter residues demonstrated reduced calcium levels in the presence of EM, which were negatively correlated with EM rootlet-colonizing mass. The lack of EM effect on the litter decomposition rate, coupled with high EM colonization, suggests an important but indirect role in mineral nutrient acquisition. Lowered Ca concentration in leaf litter exposed to EM may suggest a high Ca demand by the ectotroph system.
Assuntos
Fabaceae/microbiologia , Micorrizas/fisiologia , Folhas de Planta/metabolismo , Clima Tropical , Cálcio/análise , Fabaceae/anatomia & histologia , Fabaceae/fisiologia , Guiana , Micorrizas/crescimento & desenvolvimento , Folhas de Planta/química , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/microbiologia , ÁrvoresRESUMO
In Guyana, we investigated seed output, and resulting seedling establishment and survival, during a 'mast' year, by the ectomycorrhizal, monodominant rainforest canopy tree Dicymbe corymbosa (Caesalpiniaceae), a species with high, synchronous seed production at intermittent years. By utilizing seed traps, the mast seed output, predation, carbon and mineral investment, and masting synchrony were quantified in 2003 in primary D. corymbosa forests. Establishment of seedling cohorts was monitored, and climatic conditions associated with masting were assessed. During 2003, D. corymbosa in the Pakaraima Mountains exhibited high, synchronous seed production with low dispersal and predation. Investment in reproductive biomass was large relative to that in other tropical forests. Recent D. corymbosa reproductive events followed El Nino-induced droughts, with little intervening seed production. Over 12 months, 40% of the 2003 seedling cohort survived. Our results suggest that D. corymbosa has a strongly bimodal fruiting pattern that allows the establishment of a large seedling bank, facilitating persistent monodominance. Resource investment in large seed crops may depend on mineral recycling via ectomycorrhizas, coupled with the reallocation of carbon from vegetative maintenance.