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1.
Sci Total Environ ; 792: 148295, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34147804

RESUMO

The N2-fixing shrub Amorpha fruticosa L. is rapidly spreading in the dry riparian natural grasslands of Europe, altering ecosystem functions and depleting plant diversity. Alteration of the N cycle represents the key factor involved in invasions by N2-fixing plants with cascading effects on plant species richness. We hypothesized that A. fruticosa encroachment strongly impacts not only the N but also the C cycle and that the magnitude of such alterations may be modulated by soil characteristics. To test these hypotheses, we selected four river floodplains in North East of Italy and compared natural uninvaded grasslands with half invaded and completely invaded sites, based on A. fruticosa stand characteristic and relevant leaf traits and on soil properties related to soil texture and to C and N cycles. Soil organic matter mineralisation, ammonification and nitrification rates were determined. Soil nitrification increased remarkably with plant invasion while ammonification was significantly higher only in half invaded sites. Soil organic matter mineralisation, microbial biomass C sustained per soil organic C unit and nitrification positively correlated with stand age, regardless to the stage of the encroachment. Mineralisation and nitrification increased with soil organic C and total N in uninvaded and completely invaded sites, but decreased in half invaded sites. At the half invasion stage, trends in nitrification and CO2 mineralisation were transitionally reverted and remediation may be facilitated by less pronounced changes in soil properties compared to completely invaded sites. Direct effects of plant invasion are modulated by the action of soil characteristics such as soil organic C and clay contents, with soils rich in organic C showing larger nitrification and mineralisation rates.


Assuntos
Fabaceae , Solo , Ecossistema , Pradaria , Nitrogênio/análise , Microbiologia do Solo
2.
Eye (Lond) ; 30(2): 255-63, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26541085

RESUMO

Light is the visible part of the electromagnetic radiation within a range of 380-780 nm; (400-700 on primates retina). In vertebrates, the retina is adapted to capturing light photons and transmitting this information to other structures in the central nervous system. In mammals, light acts directly on the retina to fulfill two important roles: (1) the visual function through rod and cone photoreceptor cells and (2) non-image forming tasks, such as the synchronization of circadian rhythms to a 24 h solar cycle, pineal melatonin suppression and pupil light reflexes. However, the excess of illumination may cause retinal degeneration or accelerate genetic retinal diseases. In the last century human society has increased its exposure to artificial illumination, producing changes in the Light/Dark cycle, as well as in light wavelengths and intensities. Although, the consequences of unnatural illumination or light pollution have been underestimated by modern society in its way of life, light pollution may have a strong impact on people's health. The effects of artificial light sources could have direct consequences on retinal health. Constant exposure to different wavelengths and intensities of light promoted by light pollution may produce retinal degeneration as a consequence of photoreceptor or retinal pigment epithelium cells death. In this review we summarize the different mechanisms of retinal damage related to the light exposure, which generates light pollution.


Assuntos
Poluição Ambiental/efeitos adversos , Luz/efeitos adversos , Células Fotorreceptoras de Vertebrados/efeitos da radiação , Lesões por Radiação/etiologia , Degeneração Retiniana/etiologia , Animais , Humanos , Estimulação Luminosa
3.
Environ Sci Pollut Res Int ; 23(4): 3491-502, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26490928

RESUMO

Biochar has a charcoal polycyclic aromatic structure which allows its long half-life in soil, making it an ideal tool for C sequestration and for adsorption of organic pollutants, but at the same time raises concerns about possible adverse impacts on soil biota. Two biochars were tested under laboratory-controlled conditions on Eisenia andrei earthworms: a biochar produced at low temperature from wine tree cuttings (WTB) and a commercial low tar hardwood lump charcoal (HLB). The avoidance test (48-h exposure) showed that earthworms avoid biochar-treated soil with rates higher than 16 t ha(-1) for HLB and 64 t ha(-1) for WTB. After 42 days, toxic effects on earthworms were observed even at application rates (100 t ha(-1)) that are generally considered beneficial for most crops. The concentration of HLB and WTB required to kill half of earthworms' population (LC50; 95% confidence limits) in the synthetic OECD soil was 338 and 580 t ha(-1), respectively. Accumulation of polycyclic aromatic hydrocarbons (PAH) in earthworms exposed to the two biochar types at 100 t ha(-1) was tested in two soils of different texture. In biochar-treated soils, the average earthworm survival rates were about 64% in the sandy and 78% clay-loam soils. PAH accumulation was larger in the sandy soil and largest in soils amended with HLB. PAH with less than four rings were preferentially scavenged from the soil by biochars, and this behaviour may mask that of the more dangerous components (i.e. four to five rings), which are preferentially accumulated. Earthworms can accumulate PAH as a consequence of exposure to biochar-treated soils and transfer them along the food chain. Soil type and biochar quality are both relevant in determining PAH transfer.


Assuntos
Carvão Vegetal , Oligoquetos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Adsorção , Animais , Carvão Vegetal/toxicidade , Meia-Vida , Dose Letal Mediana , Oligoquetos/efeitos dos fármacos , Oligoquetos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade
4.
Epilepsy Res ; 98(2-3): 130-4, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21944894

RESUMO

We aimed to compare apparent steady-state oral clearance (CL/F) of the antiepileptic drug levetiracetam (LEV) in elderly (66-80 years, n=105) and very elderly (81-96 years, n=70) vs nonelderly (30-65 years, n=97) patients with epilepsy. Median weight-normalized CL/F (mLmin(-1)kg(-1)) decreased from 1.23 (nonelderly) to 0.83 (elderly) and 0.59 (very elderly) (p<0.001). LEV CL/F significantly declines with aging, elderly and very elderly patients requiring an about 30% and 50% lower dose, respectively, compared to nonelderly adults to achieve a given LEV plasma concentration.


Assuntos
Anticonvulsivantes/sangue , Anticonvulsivantes/uso terapêutico , Epilepsia/sangue , Epilepsia/tratamento farmacológico , Piracetam/análogos & derivados , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Geriatria , Humanos , Levetiracetam , Masculino , Pessoa de Meia-Idade , Piracetam/sangue , Piracetam/uso terapêutico , Estudos Prospectivos , Estudos Retrospectivos
5.
Waste Manag ; 28(4): 716-22, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18383584

RESUMO

Soil organic matter comprises all dead plant and animal residues, from the most recent inputs to the most intensively humified. We have found that traces of fresh substrates at microg g(-1) soil concentrations (termed 'trigger molecules') activate the biomass to expend more energy than is contained in the original 'trigger molecules'. In contrast, we suggest that the rate limiting step in soil organic matter mineralisation is independent of microbial activity, but is governed by abiological processes (which we term the Regulatory Gate theory). These two findings have important implications for our understanding of carbon mineralisation in soil, a fundamental process in the sequestration of soil organic matter.


Assuntos
Carbono/metabolismo , Microbiologia do Solo , Trifosfato de Adenosina/metabolismo , Aminoácidos/metabolismo , Biomassa , Dióxido de Carbono/metabolismo , Ácidos Graxos/metabolismo , Glucose/metabolismo , Ácido Glutâmico/metabolismo , Extratos Vegetais/metabolismo , Hidrolisados de Proteína/metabolismo , Solo
6.
Waste Manag ; 28(4): 723-33, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18042372

RESUMO

Biological and chemical stabilization of organic C was assessed in soils sampled from the long-term experiments at Rothamsted (UK), representing a wide range of carbon inputs and managements by extracting labile, non-humified organic matter (NH) and humic substances (HS). Four sequentially extracted humic substances fractions of soil organic matter (SOM) were extracted and characterized before and after a 215-day laboratory incubation at 25 degrees C from two arable soils, a woodland soil and an occasionally stubbed soil. The fractions corresponded to biochemically stabilised SOM extracted in 0.5M NaOH (free fulvic acids (FA) and humic acids (HA)) and chemically plus biochemically stabilised SOM extracted from the residue with 0.1M Na4P2O7 plus 0.1M NaOH (bound FA and HA). Our aim was to investigate the effects of chemical and biochemical stabilization on carbon sequestration. The non-humic to humic (NH/H) C ratio separated the soils into two distinct groups: arable soils (unless fertilised with farmyard manure) had an NH/H C ratio between 1.05 and 0.71, about twice that of the other soils (0.51-0.26). During incubation a slow, but detectable, decrease in the NH/H C ratio occurred in soils of C input equivalent or lower to 4Mgha(-1)y(-1), whereas the ratio remained practically constant in the other soils. Before incubation the free to bound humic C ratio increased linearly (R2=0.91) with C inputs in the soils from the Broadbalk experiment and decreased during incubation, showing that biochemical stabilization is less effective than chemical stabilization in preserving humic C. Changes in delta13C and delta15N after incubation were confined to the free FA fractions. The delta13C of free FA increased by 1.48 and 0.80 per thousand, respectively, in the stubbed and woodland soils, indicating a progressive biological transformation. On the contrary, a decrease was observed for the bound FA of both soils. Concomitantly, a Deltadelta15N of up to +3.52 per thousand was measured after incubation in the free FA fraction and a -2.58 Deltadelta15N in the bound FA. These changes, which occurred during soil incubation in the absence of C inputs, indicate that free FA fractions were utilised by soil microorganisms, and bound FA were decomposed and replaced, in part, by newly synthesized FA. The 13CPMAS-TOSS NMR spectra of free HA extracted before and after 215 days of incubation were mostly unchanged. In contrast, changes were evident in bound HA and showed an increase in aromatic C after incubation.


Assuntos
Benzopiranos/análise , Carbono/análise , Substâncias Húmicas/análise , Solo/análise , Reino Unido
7.
Histol Histopathol ; 22(3): 261-72, 2007 03.
Artigo em Inglês | MEDLINE | ID: mdl-17163400

RESUMO

Detailed characterization of the subdermal model is a significant tool for better understanding of calcification mechanisms occurring in heart valves. In previous ultrastructural investigation on six-week-implantated aortic valve leaflets, modified pre-embedding glutaraldehyde-cuprolinic-blue reactions (GA-CB) enabled sample decalcification with concurrent retention/staining of lipid-containing polyanionic material, which lined cells and cell-derived matrix-vesicle-like bodies (phthalocyanin-positive layers: PPLs) co-localizing with the earliest apatite nucleation sites. Additional post-embedding silver staining (GA-CB-S) revealed PPLs to contain calcium-binding sites. This investigation concerns valve leaflets subjected to shorter implantation times to shed light on the modifications associated with PPLs generation and calcification onset/progression. Spectrometric estimations revealed time-dependent calcium increase, for unreacted samples, and copper modifications indicating an increase in acidic, non-glycanic material, for GA-CB-reacted samples. Two-day-implant thin sections showed emission and subsequent reabsorption of lamellipodium-like protrusions by cells, originating ECM-containing vacuoles, and/or degeneration stages characterized by the appearance of GA-CB-S-reactive, organule-derived dense bodies and progressive dissolution of all cell membranes. In one-week-implants, the first PPL-lined cells were found to co-exist with cells where GA-CB-S-reactive material accumulated, or exudated towards their edges, or outcropped at the ECM milieu, so acquiring PPL features. PPL-derived material was observed increasingly to affect the ECM on thin sections of one-week- to six-week-implants. These results show an endogenous source for PPLs and reveal that a peculiar cascade of cell degenerative steps is associated with valve mineralization in the subdermal model, providing new useful parameters for more reliable comparison of this experimental calcification process versus the physiological and pathological processes.


Assuntos
Valva Aórtica/ultraestrutura , Calcinose/patologia , Cálcio/metabolismo , Animais , Valva Aórtica/metabolismo , Valva Aórtica/transplante , Calcinose/metabolismo , Cálcio/análise , Modelos Animais de Doenças , Imuno-Histoquímica , Masculino , Microscopia Eletrônica de Transmissão , Ratos , Ratos Sprague-Dawley , Coloração pela Prata , Espectrometria de Massas por Ionização por Electrospray , Suínos , Fatores de Tempo
8.
Ann Intern Med ; 145(3): 157-64, 2006 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16880457

RESUMO

BACKGROUND: The use of non-heart-beating donors could help shorten the list of patients who are waiting for a kidney transplant. Several reports describe acceptable results of transplantations from non-heart-beating donors who had in-hospital cardiac arrest, but few reports describe results of transplantations from non-heart-beating donors who had cardiac arrest that occurred outside of the hospital (Maastricht type I and type II donors). OBJECTIVE: To compare graft survival rates among patients receiving kidneys from heart-beating donors versus type I or type II non-heart-beating donors. DESIGN: Retrospective cohort study of transplantations performed from January 1989 to December 2004. SETTING: Kidney transplant program of a teaching hospital in Madrid, Spain. PATIENTS: 320 patients who received a kidney transplant from non-heart-beating donors (273 type I donors and 47 type II donors) and 584 patients who received a kidney transplant from heart-beating donors divided into 2 groups according to donor age (age <60 years [n = 458] and age > or =60 years [n = 126]). MEASUREMENTS: The primary outcome measure was graft survival. The median follow-up time was 68 months (range, 9 to 198 months). RESULTS: One- and 5-year graft survival rates were 90.7% and 85.5%, respectively, for transplants from heart-beating donors younger than 60 years of age; 79.8% and 73.3%, respectively, for transplants from heart-beating donors 60 years of age or older (P < 0.001); and 87.4% and 82.1%, respectively, for transplants from non-heart-beating donors (P = 0.22 [vs. those from heart-beating donors < 60 years of age] and P = 0.014 [vs. those from heart-beating donors >or = 60 years of age]). Graft survival did not differ between patients who received kidneys from heart-beating donors younger than 60 years of age and patients who received kidneys from non-heart-beating donors. LIMITATIONS: This single-site, observational study was retrospective, and immunosuppressive therapy regimens given to transplant recipients varied over time. CONCLUSIONS: Outcomes of transplants from non-heart-beating donors and younger heart-beating donors are similar, and results for transplants from non-heart-beating donors improved compared with those from older heart-beating donors. On the basis of these results, the authors encourage other transplant units to adopt the use of type I and type II non-heart-beating donors.


Assuntos
Sobrevivência de Enxerto , Parada Cardíaca , Transplante de Rim , Doadores de Tecidos , Adulto , Idoso , Estudos de Coortes , Função Retardada do Enxerto , Feminino , Rejeição de Enxerto , Humanos , Imunossupressores/uso terapêutico , Transplante de Rim/fisiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Transplante Homólogo
9.
Transpl Int ; 18(3): 333-40, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15730495

RESUMO

The main difference between cadaveric kidneys from donors with a heartbeat (HBD) and kidneys from nonheart-beating donors (NHBD) is related to warm ischemia/reperfusion time which constitutes an acute inflammatory process. On the contrary, brain death induces in HBD expression of pro-inflammatory adhesion molecules, making it important to evaluate this kind of molecules in both types of donors. Human renal biopsies from NHBD, HBD and normal kidneys (ischemia time = 0) were taken and frozen just before transplant. A semi-quantitative RT-PCR method was used to determine intracellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), lymphocyte function associated antigen (LFA-1), LFA-3, CD40, CD40 ligand (CD40L) and RANTES (regulated upon activation, normal T-cell expressed and secreted) gene expression. We have detected an elevated relative gene expression of ICAM-1, VCAM-1 and RANTES in NHBD biopsies compared with normal kidneys. In the case of RANTES, the gene expression from NHBD biopsies was higher than observed in HBD biopsies. The rest of genes were not augmented in any group. Preliminary data about early outcome of transplants indicates a correlation between pretransplant RANTES high gene expression levels and early post-transplant acute rejection. The gene expression of pro-inflammatory molecules like adhesion molecules and RANTES is augmented in kidneys from cadaveric NBD just before transplant. The expression is higher probably because of the prolonged warm ischemia period. A larger clinical study is necessary to clarify the effects of these variable expressions on the transplant outcome.


Assuntos
Quimiocina CCL5/genética , Molécula 1 de Adesão Intercelular/genética , Transplante de Rim , Doadores de Tecidos , Molécula 1 de Adesão de Célula Vascular/genética , Adulto , Humanos , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
Transplant Proc ; 36(10): 3016-8, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15686684

RESUMO

BACKGROUND: Renal allograft rupture is an early postoperative complication threatening graft and patient survival. We reviewed the etiology and prognostic factors for renal allograft rupture. MATERIAL AND METHODS: Among 657 renal transplants performed between 1990 and 2001, renal allograft rupture was diagnosed in 10 cases. Statistical analysis by Student t test, ANOVA, and chi-square was performed to assess donor and recipient characteristics. Multivariate logistic regression to predict renal allograft rupture used variables with P <.15 in the univariate analysis. RESULTS: Patients with renal allograft rupture were mainly men and young. Renal allograft rupture incidence was higher among allografts from non-heart-beating donors, kidneys with delayed graft function, or patients with a high antibody titer. Histopathological findings revealed that six renal allograft ruptures were secondary to acute rejection, three to acute tubular rejection and one to allograft infarction. Only one of six renal allograft ruptures (17.7%) secondary to rejection was resolved by surgery; two of the three patients (66.7%) with acute tubular necrosis were successfully operated and a nephrectomy was performed for the patient with allograft infarction. By multivariate logistic regression analysis, factors shown to be predictive for renal allograft rupture were: delayed graft function, age of recipient, peak panel-reactive antibody >25%, and initial immunosuppressive treatment without antithymocyte globulin. CONCLUSIONS: Higher graft salvage rates are possible in cases of graft rupture associated with acute tubular necrosis.


Assuntos
Transplante de Rim/efeitos adversos , Transplante de Rim/patologia , Túbulos Renais/patologia , Complicações Pós-Operatórias/terapia , Ruptura , Terapia de Salvação/métodos , Adulto , Feminino , Humanos , Isoanticorpos/sangue , Masculino , Estudos Retrospectivos , Transplante Homólogo/efeitos adversos , Transplante Homólogo/patologia
11.
Neurol Sci ; 24(3): 192-3, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14598082

RESUMO

We examined the potential sex-related differences in levodopa pharmacokinetics and their relation with the presence of dyskinesias in a group of 115 patients (67 men, 49 women) with Parkinson's disease. The patients were given a standard oral dose of levodopa plus benserazide (100/25 mg). The area under the levodopa plasma concentration time curve, corrected for the levodopa test dose (in mg/kg body weight), (AUC(w)) was significantly higher in women than in men, with a reduced oral clearance. No difference in the proportion of men and women experiencing dyskinesias was observed.


Assuntos
Antiparkinsonianos/sangue , Discinesias/etiologia , Levodopa/sangue , Doença de Parkinson/sangue , Caracteres Sexuais , Idoso , Antiparkinsonianos/efeitos adversos , Antiparkinsonianos/uso terapêutico , Área Sob a Curva , Benserazida/uso terapêutico , Estudos de Casos e Controles , Discinesias/sangue , Feminino , Meia-Vida , Humanos , Levodopa/efeitos adversos , Levodopa/uso terapêutico , Modelos Lineares , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Doença de Parkinson/tratamento farmacológico
13.
Clin Auton Res ; 11(3): 163-8, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11605821

RESUMO

Metoclopramide (MCP), a central and peripheral dopaminergic blocker with cholinergic activity, has been proposed to treat orthostatic hypotension (OH) on the basis that it could antagonize the vasodilator and natriuretic effects of dopamine. The authors evaluated cardiovascular responses to MCP in 11 subjects with OH: 6 with multiple system atrophy (MSA) and 5 with pure autonomic failure (PAF), along with 6 healthy control subjects. Supine blood pressure (BP), heart rate (HR), and breathing were continuously monitored before, during, and after MCP infusion. The pre-MCP head-up tilt test was tolerated at 65 degrees for 10 minutes in all subjects except in one with PAF, who tolerated 30 degrees for only 5 minutes. Tilting confirmed the OH in patients with MSA (change in mean arterial pressure [deltaMAP] = -31 +/- 13 mm Hg) and PAF (AMAP = -34 +/- 8 mm Hg). Infusion of MCP was given in four 5-mg doses every 5 minutes, with the subject in a supine position. Infusion of MCP induced the following effects: (1) A transient hypotensive effect occurred after each infusion in both patients and control subjects, the fall in MAP being counteracted by an increase in HR in control subjects but not in patients; this acute MAP fall was mo resevere in patients. (2) A progressive reduction of MAP occurred during the test,which never returned to preinfusion levels in patients; this effect was so pronounced in two PAF patients as to prevent them from receiving the last dose. Post-MCP tilting was tolerated in control subjects but in only in 5 MSA patients and 4 PAF patients. In those patients who tolerated the test, the MAP fall was similar to, or worse than, that before MCP (MSA: deltaMAP = -28 +/- 16 mm Hg; PAF: deltaMAP = -38 +/- 16 mm Hg). The cardiovascular effect of MCP in normal subjects was a transient hypotension counterbalanced by reflex tachycardia. The lack of an HR increase and the progressive fall in supine BP in MSA and PAF patients, together with worsening orthostatic tolerance after MCP infusion, are effects that should strongly discourage the use of this drug in the treatment of OH.


Assuntos
Doenças do Sistema Nervoso Autônomo/tratamento farmacológico , Antagonistas de Dopamina/uso terapêutico , Hemodinâmica/efeitos dos fármacos , Metoclopramida/uso terapêutico , Atrofia de Múltiplos Sistemas/tratamento farmacológico , Idoso , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipotensão Ortostática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Atrofia de Múltiplos Sistemas/fisiopatologia , Decúbito Dorsal/fisiologia
14.
J Chromatogr B Biomed Sci Appl ; 761(1): 133-7, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11585128

RESUMO

We present a simple and fast method for the determination of the novel antiepileptic drug topiramate in human plasma by high-performance liquid chromatography coupled with turbo ion spray mass spectrometry. Plasma sample pre-treatment was based on simple deproteinization by acetonitrile. Liquid chromatographic analysis was carried out on a reversed-phase column (C18, 125x4 mm I.D., 5 microm) using acetonitrile-ammonium acetate buffer, pH 6.3 as the mobile phase, at a flow-rate of 0.8 ml/min. Retention time for topiramate was 2.1 min. The detector was a single quadrupole mass spectrometer coupled to a turbo ion spray ion source and a heated nebulizer probe, operating in the positive ion mode. Ion source temperature was off; voltage was +5800 V; nebulizer and curtain gas flow-rates were 6 and 10 ml/min, respectively. Calibration curves for topiramate were linear over the range 1 to 20 microg/ml. Absolute recovery ranged between 92 and 95%. Intra- and inter-assay precision was <4%. The present procedure, omitting extraction and drying steps, is faster and simpler than the previously reported analytical methods for topiramate and was demonstrated to possess adequate sensitivity for routine therapeutic drug monitoring in plasma from patients with epilepsy.


Assuntos
Anticonvulsivantes/sangue , Frutose/análogos & derivados , Frutose/sangue , Espectrometria de Massas/métodos , Anticonvulsivantes/farmacocinética , Monitoramento de Medicamentos , Frutose/farmacocinética , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Topiramato
16.
Mov Disord ; 16(2): 226-32, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11295774

RESUMO

OBJECTIVE: To evaluate whether the circadian rhythm of body core temperature (CRT degrees ) can differentiate Multiple-System Atrophy (MSA) from Idiopathic Parkinson's disease (IPD). METHODS: We evaluated 14 patients with probable MSA, seven with IPD, and eight controls. After a preliminary evaluation of cardiovascular autonomic function, rectal temperature and sleep-wake cycle were monitored continuously for 48 hours in a temperature-controlled room, at constant bed rest with controlled food intake and fixed light-dark schedule. RESULTS: MSA patients showed cardiovascular autonomic sympathetic and parasympathetic failure. IPD had normal cardiovascular autonomic function. A 24-hour rhythm of body core temperature (BcT degrees ) was present in all subjects. IPD had CRT degrees comparable to controls. In MSA the mesor was higher and mean BcT degrees of each hour was significantly higher from 11 p.m. to 7 a.m. The analysis of mean BcT degrees during the different sleep phases showed significantly higher values during both NREM (1--2, 3--4) and REM sleep stages in MSA. CONCLUSIONS: The physiological nocturnal fall of BcT degrees is blunted in MSA patients mainly because BcT degrees did not decrease during sleep. This CRT degrees pattern is not justified by differences in sleep structure and may reflect an impairment of central sympathetic nervous system function.


Assuntos
Temperatura Corporal/fisiologia , Ritmo Circadiano/fisiologia , Atrofia de Múltiplos Sistemas/diagnóstico , Doença de Parkinson/diagnóstico , Doença de Parkinson/fisiopatologia , Adulto , Doenças do Sistema Nervoso Autônomo/diagnóstico , Doenças do Sistema Nervoso Autônomo/etiologia , Regulação da Temperatura Corporal/fisiologia , Sistema Cardiovascular/fisiopatologia , Eletroencefalografia , Eletromiografia , Eletroculografia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Atrofia de Múltiplos Sistemas/complicações , Músculo Esquelético/fisiopatologia , Reflexo Anormal/fisiologia , Fases do Sono/fisiologia , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/epidemiologia , Fatores de Tempo , Vigília/fisiologia
17.
Transplantation ; 71(3): 381-6, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11233897

RESUMO

The aim of this retrospective study was to determine whether nephron mass may exert a direct, independent effect on immunological tolerance. To this end, data corresponding to patients transplanted with en block pediatric kidneys (EBPK) (n=48) were compared with those of renal transplants with a low risk of hyperfiltration (LRH) comprised of recipients of a kidney from young donors (age 5-40 years) (n=173), and transplants with a high risk of hyperfiltration (HRH) comprised of patients who had received a graft from an elderly donor (older than 55 years) (n=91). All the patients had been subjected to the same immunosuppressive treatment. The median follow-up period was 54 months (6-127 months). The EBPK group showed lowest serum creatinine and highest creatinine clearance levels at each follow-up time. The rate of proteinuria >500 mg/day was 5.7% in EBPK, 7.4% in LRH, and 27.3% in HRH (P=0.000). The incidence of acute corticoresistant rejection was minor in EBPK (7.0% in EBPK, 21.3% in LRH, and 23.3% in HRH; P=0.04). Logistic regression analysis showed that the type of transplant was predictive of acute corticoresistant rejection [RR 5.33 (95% confidence interval (CI) 1.15-24.62) for HRH and RR 4.75 (95%CI 1.06-21.27) for LRH, P=0.03]. Multivariate analyses for graft failure due to chronic rejection and for graft failure due to acute rejection according to Cox's regression analysis demonstrated that HRH transplant was a significant predictive variable of both types of failure [4.08 (95%CI 1.27-13.04) for graft loss due to chronic rejection and 8.69 (95%CI 1.69-44.67) for graft loss due to acute rejection]. The present stratification of data according to nephronal mass would appear to indicate that the greater the mass, the lower the incidence of both acute and chronic rejection. This finding lends support to the hypothesis that a large mass of transplanted tissue relative to recipient mass may dampen the immune response.


Assuntos
Transplante de Rim , Rim/fisiopatologia , Adulto , Pré-Escolar , Creatinina/sangue , Feminino , Taxa de Filtração Glomerular , Rejeição de Enxerto , Sobrevivência de Enxerto/fisiologia , Humanos , Lactente , Rim/patologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada
18.
Ther Drug Monit ; 23(6): 621-9, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11802094

RESUMO

The authors assessed differences in both therapeutic and dyskinesia-matched concentrations of levodopa by kinetic-dynamic modeling in a large cohort of patients with Parkinson disease grouped by severity of symptoms. The goal was to provide a kinetic-dynamic approach to levodopa therapy monitoring to assist treating physicians in rationalizing patients' drug schedules in line with disease progression. Eighty-six patients, grouped according to Hoehn & Yahr (H&Y) clinical stage (H&Y I, n = 23; II, n = 25; III; n = 25; IV, n = 13) enrolled in the study. After a 12-hour levodopa washout each patient was examined using a standard oral levodopa test, based on simultaneous serial measurements of plasma levodopa concentrations, finger-tapping motor effects, and dyskinesia ratings. The kinetic-dynamic modeling for both effects was carried out according to the "link" effect compartment model and sigmoidal pharmacodynamic model. Levodopa plasma kinetics did not differ among patient groups. Duration of motor response was significantly (p < 0.001) curtailed in patients in advanced clinical stages whereas dyskinesia duration showed minor changes among the three affected groups (H&Y II, III, and IV). Median effective concentrations (EC 50 ) were increased at the more advanced clinical stage (p < 0.001), from a median 0.2 microg/mL in patients at H&Y stage I to 0.9 microg/mL in patients at H&Y stage IV, whereas the maximum effect showed less consistent changes among the four groups. Intrasubject levodopa therapeutic concentrations were lower than values for dyskinesias in patients at the moderate stage of the disease, equaling dyskinesia-matched drug concentrations in the more affected patients. These findings are in line with previous observations of major changes in levodopa concentration-effects relationship with disease progression and support a stratification of patients with Parkinson disease according to kinetic-dynamic modeling. From a practical point of view, knowledge of individual patients' kinetic-dynamic variables can help the physician assess patients' clinical needs objectively and optimize levodopa dosing according to disease progression.


Assuntos
Antiparkinsonianos/sangue , Monitoramento de Medicamentos , Levodopa/sangue , Doença de Parkinson/tratamento farmacológico , Adulto , Idoso , Feminino , Humanos , Levodopa/uso terapêutico , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Atividade Motora/efeitos dos fármacos , Doença de Parkinson/metabolismo
20.
J Am Soc Nephrol ; 11(2): 350-358, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10665943

RESUMO

The aim of this study was to compare the survival and midterm function of kidneys from non-heart beating donors (NHBD) with those of kidneys from heart beating donors (HBD). From 1989 to 1998, 144 kidneys were procured from NHBD at the Hospital Clínico San Carlos in Madrid, of which 95 were transplanted. The kidney grafts were maintained from the moment of the diagnosis of cardiac arrest until the time of procurement by cardiopulmonary bypass. There was no significant difference in renal function and the number of rejection episodes between the NHBD and HBD transplants. The NHBD kidneys showed a 5.73-fold increase in the incidence of delayed graft function (adjusted relative risk 95% confidence interval, 2.82 to 11.62). One- and five-year survival rates for NHBD grafts were 84.6 and 82.7%, respectively, compared with 87.5 and 83.9% for HBD (P = 0.5767). Cox analysis showed that the predictive factors for worse NHBD graft survival were type of NHBD donor and the occurrence of corticoresistant rejection. Ninety of the NHBD organs were procured from subjects suffering irreversible cardiac arrest on the street who were transferred to our center for the sole purpose of donation. Fifty-four of these kidneys were transplanted and all showed primary function. When a strict protocol is adhered to, the outcome of renal transplant from NHBD compares well with that from HBD. It is believed that the high number of organs obtained from subjects undergoing irreversible cardiac arrest on the street might encourage the adoption of new criteria for the management of this type of pathology with the ultimate goal of kidney donation.


Assuntos
Morte Encefálica/fisiopatologia , Parada Cardíaca , Transplante de Rim , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/métodos , Adulto , Feminino , Sobrevivência de Enxerto , Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Modelos de Riscos Proporcionais
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