RESUMO
BACKGROUND: Several studies have shown an association between 25-hydroxyvitamin D (25[OH]D) levels and multiple sclerosis (MS) susceptibility and/or level of disease activity in patients treated with first line drugs. AIMS: To investigate whether baseline 25[OH]D values could influence disease activity also during treatment with the second-line drug fingolimod (FTY). PATIENTS AND METHODS: We enrolled 176 MS patients who started FTY at the San Raffaele Hospital (OSR) MS center with available 25[OH]D measurement at the time of treatment start. We then prospectively followed them for 2 years with periodic clinical examinations and MRI scans. RESULTS: We found no linear correlation between baseline 25[OH]D levels and annualized relapse rate (ARR) or time to first relapse. However, we observed that patients with serum 25[OH]D ≥ 100 nmol/l showed a lower number of Gd+ and combined unique activity (CUA) lesions at baseline compared to patients with the lowest 25[OH]D levels (less than 50 nmol/l, p value < 0.05). Moreover, they showed fewer CUA lesions at 2-year follow-up also when accounting for baseline level of disease activity (p value < 0.05). CONCLUSIONS: In patients treated with FTY, those with the highest baseline 25(OH)D levels had a significantly lower number of active lesions at baseline; the same effect, even if weaker, was observed also at 2-year follow-up when adjusting for baseline disease activity. Given Vitamin D supplementation safety profile, also if a causal effect has not yet been shown, most of MS patients could probably benefit from 25[OH]D levels above those currently considered to be sufficient.
Assuntos
Cloridrato de Fingolimode/uso terapêutico , Imunossupressores/uso terapêutico , Esclerose Múltipla Recidivante-Remitente/sangue , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Vitamina D/análogos & derivados , Adulto , Feminino , Gadolínio/efeitos adversos , Humanos , Processamento de Imagem Assistida por Computador , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Estatísticas não Paramétricas , Fatores de Tempo , Vitamina D/sangueRESUMO
OBJECTIVES: Since its introduction, MRI had a major impact on the early and more precise diagnosis of multiple sclerosis (MS), and the 2010 diagnostic criteria even allow a diagnosis to be made just after a single attack if stringent MRI criteria are met. Several other clinical and paraclinical markers have been reported to be associated with an increased risk of MS independently of MRI in patients with clinically isolated syndromes (CIS), but the incremental usefulness of adding them to the current criteria has not been evaluated. In this study, we determined whether multiple biomarkers improved the prediction of MS in patients with CIS in a real-world clinical practice. MATERIALS AND METHODS: This was a retrospective study involving patients with CIS admitted to our department between 2000 and 2013. We evaluated baseline clinical, MRI, neurophysiological, and cerebrospinal fluid (CSF) data. RESULTS: During follow-up (median, 7.2 years), 127 of 243 participants (mean age, 31.6 years) developed MS. Cox proportional-hazards models adjusted for established MRI criteria, age at onset, number of T1 lesions, and presence of CSF oligoclonal bands significantly predicted the risk of developing MS at 2 and 5 years. The use of multiple biomarkers led to 29% net reclassification improvement at 2 years (P<.001) and 30% at 5 years (P<.001). CONCLUSIONS: The simultaneous addition of several biomarkers significantly improved the risk stratification for MS in patients with CIS beyond that of a model based only on established MRI criteria.
Assuntos
Esclerose Múltipla/diagnóstico , Adulto , Idade de Início , Biomarcadores/líquido cefalorraquidiano , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/líquido cefalorraquidiano , Esclerose Múltipla/diagnóstico por imagem , Modelos de Riscos ProporcionaisRESUMO
OBJECTIVE: To assess the long-term benefit-risk profile of repeated courses of rituximab in Caucasian patients affected by neuromyelitis optica (NMO) and related disorders, in everyday clinical practice. METHODS: This is a prospective observational study performed at San Raffaele Hospital, Milan, Italy. From February 2006, we recruited 21 patients affected by NMO and NMO spectrum of disorders (NMOSD) whom underwent at least one cycle of intravenous (i.v.) rituximab and then were followed for at least 2 years. RESULTS: At a mean follow-up time of 48 months, we observed a significant reduction of the annualized relapse rate (ARR), from 2.0 to 0.16 (p < 0.01); and of the median Expanded Disability Status Scale (EDSS), from 5.5 to 4.0 (p < 0.013). There were 12 patients (57%) who remained disease free during the follow-up period. Five patients (24%) reported mild hematological adverse events. Serious infectious adverse events were reported by another four patients: These were all wheelchair bound at the beginning of their rituximab treatment. CONCLUSIONS: A fixed treatment scheme of rituximab, with re-treatment every 6 months, was efficacious for NMO and NMOSD, with a good safety profile; however, to obtain an even better benefit-risk ratio, close monitoring of CD19(+) B cells should be performed before the re-treatment of patients with high-level disability, concomitant leukopenia and hypogammaglobulinemia.
Assuntos
Imunossupressores/administração & dosagem , Neuromielite Óptica/tratamento farmacológico , Rituximab/administração & dosagem , População Branca , Adulto , Idoso , Avaliação da Deficiência , Esquema de Medicação , Feminino , Humanos , Imunossupressores/efeitos adversos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Neuromielite Óptica/diagnóstico , Neuromielite Óptica/etnologia , Neuromielite Óptica/imunologia , Estudos Prospectivos , Recuperação de Função Fisiológica , Indução de Remissão , Rituximab/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
To evaluate the efficacy and safety of natalizumab in patients with active relapsing-remitting multiple sclerosis (MS). We included 285 MS patients receiving natalizumab. Clinical, neuroradiological and safety data were registered every 6 months. Neutralizing antibodies (NABs) were tested after 6 months of treatment. After 1 year, the annualized relapse rate decreased to 0.26, with a significant reduction compared to the previous year (2.13). At 24 months the proportion of "relapse free" patients was 78% while that of "MRI free" patients was 69%. Considering clinical and MRI cumulative activity, "disease free" patients were 63% at 24 months. A total of 18 patients showed NABs positivity. We reported 34 cases of treatment interruptions. In conclusion, our data confirm the remarkable efficacy of natalizumab in a group of patients with higher disease activity than that of pivotal studies.
Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Vigilância de Produtos Comercializados/tendências , Adulto , Estudos de Coortes , Hipersensibilidade a Drogas/etiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Natalizumab , Resultado do Tratamento , Adulto JovemRESUMO
There is no consensus on which drugs/techniques/strategies can affect mortality in the perioperative period of cardiac surgery. With the aim of identifying these measures, and suggesting measures for prioritized future investigation we performed the first International Consensus Conference on this topic. The consensus was a continuous international internet-based process with a final meeting on 28 June 2010 in Milan at the Vita-Salute University. Participants included 340 cardiac anesthesiologists, cardiac surgeons, and cardiologists from 65 countries all over the world. A comprehensive literature review was performed to identify topics that subsequently generated position statements for discussion, voting, and ranking. Of the 17 major topics with a documented mortality effect, seven were subsequently excluded after further evaluation due to concerns about clinical applicability and/or study methodology. The following topics are documented as reducing mortality: administration of insulin, levosimendan, volatile anesthetics, statins, chronic ß-blockade, early aspirin therapy, the use of pre-operative intra-aortic balloon counterpulsation, and referral to high-volume centers. The following are documented as increasing mortality: administration of aprotinin and aged red blood cell transfusion. These interventions were classified according to the level of evidence and effect on mortality and a position statement was generated. This International Consensus Conference has identified the non-surgical interventions that merit urgent study to achieve further reductions in mortality after cardiac surgery: insulin, intra-aortic balloon counterpulsation, levosimendan, volatile anesthetics, statins, chronic ß-blockade, early aspirin therapy, and referral to high-volume centers. The use of aprotinin and aged red blood cells may result in increased mortality.
Assuntos
Procedimentos Cirúrgicos Cardíacos/mortalidade , Cuidados Críticos , Anestesia , HumanosRESUMO
BACKGROUND: A gradient of prevalence of MS has been previously reported, and this may be due to different environmental and genetic features of the different populations, but also to methodological issues. In France, for example, three studies analysed the presence of such a gradient with conflicting results. The aim of this study was to assess whether digital epidemiology could confirm the presence of such a gradient. METHODS: through Google Trends, we analysed the relative search volume (RSV) for 'multiple sclerosis' in France, from 2004 to 2017, and assessed if an association with the decimal degree of latitude existed. RESULTS: Latitude was correlated with crude RSV (r2 0.39, p 0.04) in the 21 regions considered, with a southwest/northeast gradient. A multiple linear regression model adjusted for sex and age confirmed the existence of such a latitudinal effect, with an increase of 2.43 RSV units for each unit increase in latitude (95% CIs 0.62-4.24, p < 0.01, adjusted r2 0.61). CONCLUSIONS: our study provides additional evidence for the existence of a latitude gradient in MS, and the value of Internet-acquired data as real-time surveillance tools and alerts for healthcare systems.
Assuntos
Esclerose Múltipla/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Pré-Escolar , Feminino , França/epidemiologia , Geografia Médica , Humanos , Lactente , Recém-Nascido , Internet , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores Sexuais , Adulto JovemRESUMO
BACKGROUND: Treatment choice in multiple sclerosis (MS) is crucial for optimizing risk-benefit profile. OBJECTIVE: To assess fingolimod (FTY) effectiveness and identify baseline features associated to disease activity in a large Italian cohort of Relapsing-Remitting (RR) MS patients. METHODS: Three-hundred sixty-seven RRMS patients starting FTY treatment at San Raffaele Hospital (Milan-Italy) underwent clinical and MRI evaluations for 2 years. Treatment response was assessed considering the proportion of patients with no evidence of disease activity (NEDA) and recording the time to first relapse. Primary analyses were performed stratifying for Natalizumab (NTZ) treatment in the year before (NO_NTZ vs NTZ group), to account for post-NTZ reactivation. RESULTS: Almost half of patients were NEDA after 2 years, 53.4% in the NO_NTZ group and 36.2% in the NTZ group. Despite an opposite trend during the first 6-12 months, at 2-year follow-up the two groups were comparable for relapses and number of new/enlarging T2 and Gd-enhancing lesions. Baseline parameters of higher disease activity (ARR, Gd enhancing lesions and age at onset) were associated with increased likelihood of failing NEDA criteria or with shorter time to relapse (p < 0.05). CONCLUSIONS: Our data strengthen FTY effectiveness in everyday clinical practice, even in patients switching from NTZ treatment. Baseline parameters of inflammatory activity are the most important prognostic factors for mid-term disease reactivation also during second-line treatment with FTY, providing hints on how to select therapies towards a more personalized management.
Assuntos
Cloridrato de Fingolimode/uso terapêutico , Imunossupressores/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Resultado do Tratamento , Adulto , Anticorpos Monoclonais Humanizados/uso terapêutico , Encéfalo/diagnóstico por imagem , Estudos de Coortes , Avaliação da Deficiência , Feminino , Gadolínio/farmacocinética , Humanos , Itália , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico por imagem , Natalizumab/uso terapêutico , Fatores de TempoRESUMO
Patients with idiopathic membranous nephropathy (IMN) and persistent nephrotic-range proteinuria are at risk for progression to end-stage renal failure. Whether angiotensin-converting enzyme (ACE) inhibitors are also renoprotective in these patients remains elusive. In 14 patients with IMN (patients) and persistent proteinuria (protein > 3 g/24 h for >6 months), we studied mean arterial pressure (MAP), urinary protein excretion, glomerular filtration rate (GFR), renal plasma flow (RPF), and albumin and neutral dextran fractional clearance after 2 months washout from previous antihypertensive treatment (basal), after 2 months of enalapril (2.5 to 20 mg/d) therapy (posttreatment), and 2 months after enalapril withdrawal (recovery). MAP, proteinuria, and GFR were also measured at the same time points in 6 patients with IMN and persistent overt proteinuria maintained on conventional treatment throughout the study period (controls). Basal MAP, proteinuria, and GFR were similar in the two study groups. However, in patients at the end of the treatment period, MAP (posttreatment, 99.6 +/- 11.2 versus basal, 103.3 +/- 12.1 mm Hg; P < 0.05), proteinuria (posttreatment protein, 5.0 +/- 2.9 versus basal, 7.1 +/- 4.9 g/24 h; P < 0.05), albumin fractional clearance (posttreatment median, 1.7 x 10(-3); range, 0.2 to 22.7 x 10(-3) versus basal median, 4.1 x 10(-3); range, 0.4 to 22. 1 x 10(-3); P < 0.05), and fractional clearance of largest neutral dextrans (radii from 62 to 66 A) were significantly less than basal values. At recovery, MAP significantly increased to 106.6 +/- 11.7 mm Hg (P < 0.001 versus enalapril), but all other parameters remained less than basal values. GFR and RPF were similar at each evaluation. Changes in proteinuria after treatment withdrawal positively correlated (r = 0.72; P < 0.01) with baseline GFR. Theoretical analysis of dextran-sieving data indicated that ACE inhibitor treatment significantly improved glomerular membrane size-selective dysfunction. This effect persisted more than 2 months after treatment withdrawal. No patient had symptomatic hypotension, acute renal function deterioration, or hyperkalemia during enalapril treatment. Thus, in patients with IMN and long-term nephrotic syndrome, ACE inhibitor treatment, but not conventional therapy, improves glomerular barrier size selectivity. The antiproteinuric effect of ACE inhibition is long lasting, especially in patients with more severe renal insufficiency. This is the premise of a long-term renoprotective effect that may limit the need for treatment with more toxic drugs.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Glomerulonefrite Membranosa/fisiopatologia , Rim/fisiopatologia , Síndrome Nefrótica/fisiopatologia , Proteinúria/tratamento farmacológico , Adulto , Idoso , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Pressão Sanguínea , Dextranos/urina , Feminino , Taxa de Filtração Glomerular , Glomerulonefrite Membranosa/complicações , Glomerulonefrite Membranosa/tratamento farmacológico , Humanos , Rim/efeitos dos fármacos , Rim/patologia , Masculino , Pessoa de Meia-Idade , Síndrome Nefrótica/complicações , Síndrome Nefrótica/tratamento farmacológico , Proteinúria/fisiopatologiaRESUMO
Experimental and human studies have documented that cyclosporine (CsA) acutely reduces glomerular filtration rate (GFR). It has been reported that this effect can be partially prevented by calcium (Ca) channel blockade; however, the mechanisms by which this combination exerts its beneficial effects are unknown. We evaluated glomerular ultrafiltration determinants during acute CsA administration in the rat. First, we determined that maximal whole-kidney functional changes occur between 120 and 150 minutes after CsA administration and confirmed that pretreatment of MWF rats with the Ca channel blocker lacidipine effectively prevents a reduction in GFR. Micropuncture measurements in CsA-treated animals showed that a reduction in GFR (0.49 +/- 0.24 v 0.88 +/- 0.26 mL/min; P < 0.05; CsA-treated v untreated rats) is associated with a significant increase in glomerular capillary pressure (Pgc; 63.1 +/- 2.1 v 52.8 +/- 2.8 mm Hg; P < 0.01) and efferent arteriolar resistance, whereas single-nephron (SN) GFR and ultrafiltration coefficient (Kf) are both importantly reduced (34.0 +/- 11.7 v 68.9 +/- 23.8 nL/min; P < 0.05 and 1.04 +/- 0.33 v 4.40 +/- 2.36 nL/min/mm Hg; P < 0.01, respectively). Lacidipine partially prevented SNGFR (43.1 +/- 14.3 nL/min) and Kf decline (2.08 +/- 1.10 nl/min/mm Hg) despite the presence of elevated Pgc. This study further documents that Ca channel blockade has favorable effects on CsA-induced acute renal dysfunction. The mechanism of protection includes the prevention of glomerular hemodynamic changes induced by CsA, mainly GFR decline and reduction in glomerular Kf.
Assuntos
Anti-Hipertensivos/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Ciclosporina/efeitos adversos , Di-Hidropiridinas/farmacologia , Taxa de Filtração Glomerular/efeitos dos fármacos , Imunossupressores/efeitos adversos , Glomérulos Renais/efeitos dos fármacos , Doença Aguda , Animais , Hemodinâmica/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Fatores de TempoRESUMO
We report our experience with a new access route for benign expansive bone tumors of the anterior floor of the skull. From 1991, we used a unique transfrontonasal route, adapted from Raveh's technique for trauma surgery of the anterior floor, to access all tumors in this region. The images presented here show the advantages of this technique: overall vision allows permanent intraoperative control. In addition, the absence functional or esthetic sequelae favor this route for benign tumors.
Assuntos
Craniotomia/métodos , Neoplasias Cranianas/cirurgia , Adolescente , Adulto , Osso Etmoide/cirurgia , Feminino , Seguimentos , Testa/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Osso Nasal/cirurgia , Retalhos CirúrgicosRESUMO
BACKGROUND: There is no consensus on which drugs/techniques/strategies can affect mortality in the perioperative period of cardiac surgery. With the aim of identifying these measures, and suggesting measures for prioritized future investigation we performed the first international consensus conference on this topic. METHODS: The consensus was a continuous international internet-based process with a final meeting on June 28th 2010 in Milan at the Vita-Salute University. Participants included 340 cardiac anesthesiologists, cardiac surgeons and cardiologists from 65 countries all over the world. A comprehensive literature review was performed to identify topics that subsequently generated position statements for discussion, voting and ranking. RESULTS: Of the 17 major topics with a documented mortality effect, seven were subsequently excluded after further evaluation due to concerns about clinical applicability and/or study methodology. The following topics are documented as reducing mortality: administration of insulin, levosimendan, volatile anesthetics, statins, chronic beta-blockade, early aspirin therapy, the use of preoperative intra-aortic balloon counterpulsation and referral to high-volume centers. The following are documented as increasing mortality: administration of aprotinin and aged red blood cell transfusion. These interventions were classified according to the level of evidence and effect on mortality and a position statement was generated. CONCLUSION: This international consensus conference has identified the non-surgical interventions that merit urgent study to achieve further reductions in mortality after cardiac surgery: insulin, intra-aortic balloon counterpulsation, levosimendan, volatile anesthetics, statins, chronic beta-blockade, early aspirin therapy, and referral to high-volume centers. The use of aprotinin and aged red blood cells may result in increased mortality.
RESUMO
Today angiotensin II inhibition is primarily used to slow the rate of progression of kidney diseases. There is evidence that these therapies can induce a partial regression of glomerular lesions. However, we do not know yet the extent of sclerotic lesion regression and whether new glomerular tissue is formed to help support the renal function. We used male Munich Wistar Fromter (MWF) rats, an experimental model for progressive kidney disease, to quantify kidney structural lesions upon angiotensin-converting enzyme (ACE) inhibition therapy. Animals were studied at 50 weeks of age, when renal function and structure are severely altered, and after a 10-week observation period, without or with treatment with lisinopril (80 mg/l in drinking water). A group of untreated Wistar rats was used as controls. With age, proteinuria, and serum creatinine worsen, but lisinopril almost normalized proteinuria and stabilized serum creatinine. Serial section analysis of whole glomerular tufts showed that at baseline, glomerulosclerosis affected the entire glomerular population, and that these changes further increased with age. Lisinopril significantly reduced incidence and extent of glomerulosclerosis, with the presence of glomerular tufts not affected by sclerosis (23% of glomeruli). Glomerular volume was not significantly affected by treatment, and glomerular mass spared from sclerosis increased from 46.9 to 65.5% upon treatment, indicating consistent regeneration of glomerular tissue. Lisinopril normalized baseline glomerular transforming growth factor-beta and alpha-smooth muscle actin overexpression, and prevented worsening of interstitial changes. Hence, ACE inhibition, which is widely used in human kidney disease, may not only halt the progression of renal failure, but also actually induce the regeneration of new renal tissue.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Glomerulosclerose Segmentar e Focal/tratamento farmacológico , Glomérulos Renais/fisiopatologia , Lisinopril/uso terapêutico , Animais , Capilares/patologia , Modelos Animais de Doenças , Progressão da Doença , Glomerulosclerose Segmentar e Focal/patologia , Imuno-Histoquímica , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/patologia , Masculino , Ratos , Ratos Endogâmicos , Regeneração , Circulação Renal , Fator de Crescimento Transformador beta/análiseRESUMO
An investigation was done with N.-isopropyl-iodoamphetamine (123I AMP) in 20 patients: 10 patients with craniofacial injury and 10 patients without brain dysfunction or injury. Brain X ray computerized Tomography was normal. SPECT 123 I AMP detected functional defects related with traumatic impacts. Sensitivity is higher with SPECT than with CT Scan. The indications for the initial evaluation of head injury, and the relations with later sequelae i.e. post traumatic epilepsia and subjective syndrome are discussed.
Assuntos
Anfetaminas , Encéfalo/diagnóstico por imagem , Traumatismos Faciais/diagnóstico por imagem , Radioisótopos do Iodo , Crânio/lesões , Tomografia Computadorizada de Emissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Lesões Encefálicas/diagnóstico por imagem , Feminino , Humanos , Iofetamina , Masculino , Traumatismos Maxilofaciais/diagnóstico por imagem , Pessoa de Meia-Idade , Crânio/diagnóstico por imagemRESUMO
The term permissive hypercapnia defines a ventilatory strategy for acute respiratory failure in which the lungs are ventilated with a low inspiratory volume and pressure. The aim of permissive hypercapnia is to minimize lung damage during mechanical ventilation; its limitation is the resulting hypoventilation and carbon dioxide (CO2) retention. In this article we discuss the rationale, physiologic implications, and implementation of permissive hypercapnia. We then review recent clinical studies that tested the effect of various approaches to permissive hypercapnia on the outcome of patients with acute respiratory failure.
Assuntos
Hipercapnia , Respiração Artificial/métodos , Insuficiência Respiratória/fisiopatologia , Insuficiência Respiratória/terapia , Adulto , Humanos , Hipercapnia/fisiopatologia , Hipoventilação/fisiopatologia , Recém-Nascido , Recém-Nascido Prematuro , Síndrome do Desconforto Respiratório/prevenção & controle , Medição de Risco , Volume de Ventilação Pulmonar , Resultado do TratamentoRESUMO
Techniques of tracheal gas insufflation (TGI) have been shown to enhance CO(2) clearance efficiency in mechanically ventilated patients with acute respiratory distress syndrome (ARDS). Clinical studies have explored the effects of such techniques only at moderate intratracheal gas flow rates, with TGI superimposed to mechanical ventilation in a continuous fashion, or synchronized to the expiratory phase of the duty cycle. We examined the effects of intratracheal pulmonary ventilation (ITPV), delivering the entire tidal volume (VT) in the proximity of the tracheal carina, with all the gas flow supplied continuously through a reverse-thrust catheter (RTC). A potential limitation in the application of TGI is dynamic hyperinflation. Therefore, in a subgroup of patients, we also evaluated the effects of ITPV on end-expiratory lung volume (EELV) by respiratory inductive plethysmography (RIP). Eleven patients with ARDS under volume-cycled mechanical ventilation were subsequently switched to ITPV at the same baseline respiratory rate, I:E ratio, and VT. At the same minute volume, Pa(CO(2)) decreased from 70 +/- 12.3 to 59 +/- 9.5 mm Hg, with a percent reduction of 15 +/- 4% (range from 10 to 20%). The CO(2) decrease was greater in patients with higher baseline Pa(CO(2)) levels (DeltaPa(CO(2)) = 0.29 x Pa(CO(2)) - 9.48, r = 0.95). During transition from mechanical ventilation to ITPV, tracheal positive end-expiratory pressure (PEEP(tr)) decreased with a correspondent decrease in EELV. Both were restored by increasing the PEEP at the ventilator by 3.6 +/- 2.0 cm H(2)O. These data suggest that in patients with ARDS ITPV effectively reduces dead space ventilation and the employment of the RTC may limit or avoid dynamic hyperinflation.
Assuntos
Hipercapnia/fisiopatologia , Respiração Artificial/métodos , Síndrome do Desconforto Respiratório/fisiopatologia , Adulto , Idoso , Feminino , Humanos , Hipercapnia/terapia , Insuflação , Medidas de Volume Pulmonar , Masculino , Respiração com Pressão Positiva , Troca Gasosa Pulmonar/fisiologia , Síndrome do Desconforto Respiratório/terapiaRESUMO
Studies in experimental animals and humans have documented that inhibition of the renin-angiotensin system by angiotensin-converting enzyme inhibitors reduces urinary protein excretion rate and retards the development of renal injury. Here we sought to investigate whether angiotensin II (All) modified the size-selective properties to macromolecules of the glomerular capillary barrier in isolated perfused rat kidney preparation. Compared with basal values, continuous All infusion into the renal artery at the rate of 3 or 8 ng/min, but not at 0.6 ng/min, induced a progressive and significant increase in urinary protein excretion rate. Evaluation of the sieving properties of the glomerular barrier by fractional clearance of polydisperse Ficoll showed that All significantly enhanced the filtration of tracer molecules of radil > or = 34A. All-induced changes in urinary protein excretion rate and in Ficoll fractional clearance were completely prevented by pretreatment with the specific All Type 1 receptor antagonist SR 47436.
Assuntos
Angiotensina II/farmacologia , Glomérulos Renais/efeitos dos fármacos , Antagonistas de Receptores de Angiotensina , Animais , Compostos de Bifenilo/farmacologia , Capilares/efeitos dos fármacos , Capilares/metabolismo , Permeabilidade Capilar/efeitos dos fármacos , Ficoll/farmacocinética , Irbesartana , Glomérulos Renais/irrigação sanguínea , Masculino , Taxa de Depuração Metabólica/efeitos dos fármacos , Peso Molecular , Tamanho da Partícula , Perfusão , Proteinúria/metabolismo , Ratos , Ratos Sprague-Dawley , Sistema Renina-Angiotensina/efeitos dos fármacos , Tetrazóis/farmacologiaRESUMO
Protein trafficking across the glomerular capillary has a pathogenic role in subsequent renal damage. Despite evidence that angiotensin-converting enzyme (ACE) inhibitors improve glomerular size-selectivity, whether this effect is solely due to ANG II blocking or if other mediators also play a contributory role is not clear yet. We studied 20 proteinuric patients with IgA nephropathy, who received either enalapril (20 mg/day) or the ANG II receptor blocker irbesartan (100 mg/day) for 28 days in a randomized double-blind study. Measurements of blood pressure, renal hemodynamics, and fractional clearance of neutral dextran of graded sizes were performed before and after 28 days of treatment. Both enalapril and irbesartan significantly reduced blood pressure over baseline. This reduction reached the maximum effect 4-6 h after drug administration but did not last for the entire 24-h period. Despite transient antihypertensive effect, proteinuria was effectively reduced by both treatments to comparable extents. Neither enalapril nor irbesartan modified the sieving coefficients of small dextran molecules, but both effectively reduced transglomerular passage of large test macromolecules. Theoretical analysis of sieving coefficients showed that neither drug affected significantly the mean pore radius or the spread of the pore-size distribution, but both importantly and comparably reduced the importance of a nonselective shunt pathway. These data suggest that antagonism of ANG II is the key mechanism by which ACE inhibitors exert their beneficial effect on glomerular size-selective function and consequently on glomerular filtration and urinary output of plasma proteins.