RESUMO
We hypothesized that de novo donor-specific antibody (DSA) causes complement-dependent endothelial cell injury in kidney transplants, as assessed by expression of endothelial cell-associated transcripts (ENDATs), that may be attenuated through complement inhibition. In total, 15 participants (five control, 10 treatment) with DSA and deteriorating renal function were enrolled. The treatment group received 6 mo of eculizumab followed by 6 mo of observation, whereas controls were observed. The primary end point was percentage change in estimated GFR (eGFR) trajectory over the treatment period. The treatment group had an improved eGFR trajectory versus control, based on our predetermined two-sided 0.10 significance level (p = 0.09). Within-subject analysis of treated participants at 6-mo intervals did not show significant change (p = 0.60). Modeling C1q status showed that C1q-positive patients had significantly higher mean eGFR than patients with negative C1q (p = 0.04). Biopsies revealed elevated renal ENDATs in most participants, but ENDATs were not reduced with complement inhibition. Our data suggest that eculizumab treatment may stabilize kidney function in patients with chronic persistent DSA based on our pilot a priori significance threshold. ENDAT expression predicative of acute humoral injury is not reduced with complement inhibition in this chronic setting. Further studies will be necessary to determine which patients may benefit from eculizumab.
Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Sobrevivência de Enxerto/efeitos dos fármacos , Isoanticorpos/sangue , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Adolescente , Adulto , Idoso , Doença Crônica , Complemento C5/antagonistas & inibidores , Inativadores do Complemento/uso terapêutico , Intervenção Educacional Precoce , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/imunologia , Humanos , Testes de Função Renal , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico , Fatores de Risco , Doadores de Tecidos , Transplantados , Adulto JovemRESUMO
AIMS: To compare the characteristics of the enteric-coated formulation of mycophenolate sodium (EC-MPS, myfortic) and mycophenolate mofetil (MMF, CellCept) given in combination with tacrolimus in Asian renal-transplant recipients. METHODS: In a 24-month, single-centre, randomized, open-label, prospective study, 101 live-donor kidney transplant recipients were randomized to the EC-MPS (n = 50) or MMF (n = 51) group. The incidence of infection, therapeutic effect and adverse events were monitored. RESULTS: The incidences of infection were 40% and 49% for the EC-MPS and MMF groups, respectively (p = 0.362). However, serious infection was only observed in the MMF group (11.8%; p = 0.027). The incidences of gastro-intestinal adverse events (GI AEs) were 24% and 41.2% for EC-MPS and MMF, respectively (p = 0.066). However, serious diarrhoea only occurred in the MMF group (9.8%; p = 0.056). The trough level of FK 506 at the time of diarrhoea (13.22 ± 3.66 ng/ml) was significantly higher than the level within 1 month before (9.18 ± 1.12 ng/ml; p < 0.05) and 1 month after diarrhoea (9.13 ± 0.85 ng/ml; p < 0.05). The infection rate of patients with diarrhoea was significantly higher than those without diarrhoea (68%, 39%, p = 0.024). The serum creatinine level was 698 ± 60 µmol/l for EC-MPS and 673 ± 68 µmol/l for MMF from baseline (p > 0.05), and it decreased to 66 ± 6 µmol/l for EC-MPS and 69 ± 8 µmol/l for MMF at 24 months (p > 0.05). The incidences of biopsy proven acute rejection (BPAR) were 20% and 25.5% for EC-MPS and MMF, respectively (p = 0.511). CONCLUSIONS: Enteric-coated formulation of mycophenolate sodium, given in combination with tacrolimus, has a lower incidence of serious infection in Asian renal-transplant recipients compared with MMF, and the therapeutic effect of EC-MPS is similar to MMF. The clinical trial registration number is ChiCTR-IPR-14005509. The registry name is 'Effect of Enteric-coated mycophenolate sodium on posttransplant infection rate after renal transplantation compared with Mycophenolate mofetil'.
Assuntos
Rejeição de Enxerto/tratamento farmacológico , Transplante de Rim/efeitos adversos , Ácido Micofenólico/administração & dosagem , Infecção da Ferida Cirúrgica/tratamento farmacológico , Tacrolimo/administração & dosagem , Transplantados , Administração Oral , Adulto , China/epidemiologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/administração & dosagem , Feminino , Seguimentos , Rejeição de Enxerto/epidemiologia , Humanos , Imunossupressores/administração & dosagem , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Infecção da Ferida Cirúrgica/epidemiologia , Comprimidos com Revestimento EntéricoRESUMO
BACKGROUND: Dimethyl sulfoxide-cryopreserved cadaveric vein allografts have recently been proposed as an alternative to prosthetic grafts in the problem hemodialysis population. The transfer of mismatched major histocompatibility complex I and II molecules in association with these allografts can potentially lead to allosensitization in nonimmunosuppressed individuals. METHODS: In a university-affiliated medical center, 20 consecutive patients receiving technically successful upper arm cadaveric vein allograft fistulas (CAVFs) for hemodialysis between April 1999 and April 2000 were studied. A control cohort of 20 patients on a kidney transplantation waiting list was selected by nurses blinded to the study. These patients were matched for age, sex, history of transfusion, pregnancy, cause of kidney failure, and prior transplantation. The panel reactive antibody (PRA) values were recorded in this group over the same time period as the CAVF group. RESULTS: Patients receiving CAVFs had a mean PRA assay value of 84.1% (median, 96.5%) at an average of 3.1 months after engraftment (median, 1.5 months). The preengraftment PRA values were available for seven patients who were on the transplant waiting list. Six of these patients had nonreactive PRA assays before CAVF creation. All of these patients converted to positive PRA assays after CAVF creation with a mean value of 92.3% (median, 98%) at 2.85 months follow-up (median, 1.3 months). The mean PRA value for the control cohort was 5.5% (median, 2.5%), with no patients converting from a nonreactive to a reactive PRA assay during this same time interval. CONCLUSION: The use of dimethyl sulfoxide-cryopreserved cadaveric vein allografts for hemodialysis access leads to broad allosensitization as measured by PRA assay. Cryopreserved cadaveric vein allografts should not be used for hemodialysis access in potential kidney transplant recipients.
Assuntos
Derivação Arteriovenosa Cirúrgica , Criopreservação , Transplante de Rim , Adulto , Idoso , Cadáver , Dimetil Sulfóxido , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transplante HomólogoRESUMO
It has been demonstrated previously that, in non-neutropenic animals, interferon-gamma markedly enhances the efficacies of gentamicin and vancomycin against Enterococcus faecalis resistant to these antibiotics. The aim of our study was to determining whether granulocyte colony-stimulating factor (G-CSF) can be beneficial as an adjunct to gentamicin and vancomycin in the treatment of the same infection in neutropenic mice. After induction of neutropenia by cyclophosphamide, mice were inoculated ip with the organism. The infected animals received sc administrations of G-CSF, antibiotic or a combination of both agents at determined dosing regimens. Infected animals treated with G-CSF alone showed a dose-dependent increase in survival. The inoculum size used in establishing infection affected the effectiveness of the cytokine. Survival was significantly (P: < 0.01) better in the infected animals given gentamicin and vancomycin plus G-CSF than in those given antibiotics or G-CSF alone. The possibility of pharmacokinetic interaction between G-CSF and each of the antibiotics was examined. The cytokine significantly increased the plasma clearance of gentamicin, with a resultant decrease in the area under the concentration-time curve (AUC), while the disposition of vancomycin was not affected. This study suggests that G-CSF may be a useful adjunct to gentamicin and vancomycin for the treatment of multidrug-resistant E. faecalis infection in neutropenic patients.
Assuntos
Antibacterianos/farmacocinética , Antibacterianos/uso terapêutico , Enterococcus faecalis/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Animais , Antibacterianos/farmacologia , Resistência a Múltiplos Medicamentos , Quimioterapia Combinada , Feminino , Gentamicinas/farmacocinética , Gentamicinas/farmacologia , Gentamicinas/uso terapêutico , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Camundongos , Neutropenia/induzido quimicamente , Neutropenia/tratamento farmacológico , Vancomicina/farmacocinética , Vancomicina/farmacologia , Vancomicina/uso terapêutico , Resistência a VancomicinaRESUMO
BACKGROUND: Problems with the comprehensibility of human research informed consent have been documented since the 1970s, and efforts aimed at rewriting consents have not been successful in consistently producing more readable consents. This study employed researched principles of reading comprehension research to create writing intervention program designed to help the research writer produce more comprehensible informed consent documents. The purpose of this study was to determine if this intervention program was effective. METHOD: The key component of the writing improvement intervention packet was a newly formatted consent form that contained annotated instructions for researchers on how to write each section for optimum comprehension. The resulting consent forms were evaluated using a Readability and Processability Form (RPF). The RPF is based on reading research and includes the Fry Scale, which yields an approximate grade reading level. The RPF assigned points to each of the 20 areas of comprehension analysis according to strict scoring criteria, and target scores were established by the authors in consultation with the hospital institutional review board. RESULTS: We evaluated 66 post-intervention informed consents. The mean readability and processability score was 62, resulting in the RPF classification of "good." The established readability and processability target range was good to excellent or 61-100 points; 66% of the forms scored in this range. In our 1995 pre-intervention study, the corresponding score was 12%. The target range for grade reading level was 8th grade: 53% scored in that range as compared with 4% in 1995. A question-by-question analysis of each of the 20 checklist items on the RPF identified important aspects of the consent writing that improved and others that were still weak and needed improvement. CONCLUSIONS: The Hartford Hospital writing improvement intervention program was associated with the production of more comprehensible informed consent documents. Using the intervention materials, investigators from a variety of departments could function independently to produce readable consent forms. This program may help others who wish to assist their research departments in creating consents that are written for optimal reading comprehension.
Assuntos
Cognição/fisiologia , Consentimento Livre e Esclarecido , Competência Mental , Redação , Humanos , Leitura , Estudos RetrospectivosRESUMO
Increasing antibiotic resistance and the development of multidrug-resistance in the enterococci has complicated the treatment of serious enterococcal infections. It has been demonstrated in vitro that interferon-gamma (IFN-gamma) significantly augments the activities of gentamicin and vancomycin against Enterococcus faecalis resistant to these antibiotics. The present study was aimed at determining whether this beneficial effect of IFN-gamma on antienterococcal antibiotic activity can be validated in vivo. Following intraperitoneal inoculation in mice with a gentamicin- and vancomycin-resistant E. faecalis clinical isolate, the animals received IFN-gamma, antibiotic or a combination of both agents, subcutaneously, at determined dosing regimens. Treatment with IFN-gamma alone significantly improved survival of infected animals in a dose-dependent manner. High dose IFN-gamma was not beneficial and the level of enterococcal infectious burden influenced the effectiveness of the cytokine. The addition of IFN-gamma to therapy with gentamicin or vancomycin, or a combination of both antibiotics was associated with a marked increase in survival of infected non-neutropenic mice compared to treatments with the agents alone. However, the same treatments made in infected neutropenic mice did not show an enhancement effect by IFN-gamma after a combination therapy with antibiotics. In a study to examine pharmacokinetic interactions, concurrent administration with IFN-gamma significantly modified the disposition of gentamicin but not that of vancomycin. The results of this study suggest that the use of IFN-gamma in combination with vancomycin or gentamicin is a new treatment option that might improve the outcome of therapy of multidrug-resistant E. faecalis infections.
Assuntos
Enterococcus faecalis/efeitos dos fármacos , Gentamicinas/farmacologia , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Interferon gama/uso terapêutico , Vancomicina/farmacologia , Animais , Modelos Animais de Doenças , Resistência Microbiana a Medicamentos , Quimioterapia Combinada , Enterococcus faecalis/isolamento & purificação , Feminino , Gentamicinas/administração & dosagem , Gentamicinas/uso terapêutico , Infecções por Bactérias Gram-Positivas/microbiologia , Interferon gama/farmacocinética , Camundongos , Vancomicina/administração & dosagem , Vancomicina/uso terapêuticoRESUMO
The emergence of multidrug-resistant enterococci presents a major therapeutic challenge since there is currently no clearly effective antimicrobial therapy for these infections. The combinatorial effects of interferon-gamma (IFN-gamma) with gentamicin and/or vancomycin against a clinical isolate of drug-resistant Enterococcus faecalis, were evaluated in an in vitro system with human neutrophils. Following inoculation of cultures of human neutrophils with the organism, treatments were initiated immediately after the infection and the number of viable bacteria was determined at 12, 18 and 24 h. Antibiotics were applied at concentrations close to their clinically achievable serum trough and peak levels. Treatment with IFN-gamma alone induced a maximal growth inhibition of up to 40% at a concentration of 100 U/ml. Addition of the cytokine to either therapeutic trough or peak concentrations of gentamicin and vancomycin, or a combination of both antimicrobials, was associated with a significant (P < 0.01) enhancement of anti-enterococcal activity compared with the effects of the agents alone. Investigation of a potential underlying mechanism of anti-enterococcal action of IFN-gamma reveals that it is, most probably, largely due to an activated secretion of the microbicidal reactive oxygen intermediates by neutrophils. The results of this study show that there is a possibility that IFN-gamma could be a useful adjunct in the treatment of multidrug-resistant E. faecalis.
Assuntos
Enterococcus faecalis/efeitos dos fármacos , Gentamicinas/farmacologia , Interferon gama/farmacologia , Neutrófilos/imunologia , Vancomicina/farmacologia , Terapia Combinada , Resistência Microbiana a Medicamentos , Resistência a Múltiplos Medicamentos , Gentamicinas/uso terapêutico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/microbiologia , Infecções por Bactérias Gram-Positivas/terapia , Humanos , Imunoterapia , Técnicas In Vitro , Interferon gama/uso terapêutico , Neutrófilos/microbiologia , Vancomicina/uso terapêuticoAssuntos
Transplante de Rim/estatística & dados numéricos , Doadores de Tecidos/provisão & distribuição , Obtenção de Tecidos e Órgãos/organização & administração , Algoritmos , Geografia , Alocação de Recursos para a Atenção à Saúde/métodos , Humanos , Transplante de Rim/imunologia , New England , Fatores de Tempo , Doadores de Tecidos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/métodos , Listas de EsperaRESUMO
BACKGROUND: A novel plan of renal allograft allocation has been conducted by United Network for Organ Sharing Region 1 transplant centers since September 3, 1996, based upon HLA matching, time waiting, and population distance points. The objectives of this plan were to achieve a balance between increasing the opportunity of renal transplantation for those patients listed with long waiting times and promoting local organ donor availability. METHODS: A single list of candidates was formulated for each cadaver donor, assigning a maximum of 8 points for time waiting, a maximum of 8 points for population distance from the donor hospital, and HLA points based upon the degree of B/DR mismatch. Additional points were awarded to a cross-match-negative patient with a panel-reactive antibody of >80%, and to pediatric patients. RESULTS: The total number of kidneys transplanted to patients who had waited >3 years was 100 (46%), and to patients who had waited >2.5-3 years was 29 (13%). However, the total number of kidneys transplanted to patients with the maximum population distance points was only 72 (33%). Thus, although the plan achieved a favorable distribution of kidneys to patients with longer waiting times (nearly 60%), the other, equally important objective of promoting local donor availability was not initially accomplished. Moreover, minor HLA B/DR differences between the donor and the recipient (i.e., not phenotypically matched) were unexpectedly consequential in determining allocation. As a result of these observations, the following adjustments were made in the plan (as of December 3, 1997): a maximum of 10 points for population distance, a maximum of 8 points for time waiting (both by a linear correlation), and the retention of HLA points for 0 B/DR mismatch only. After these interval changes, the percentage of patients receiving a kidney with some population distance points increased from 85% to 96%. Conclusions. We have shown that a heterogeneous region of multiple transplant centers can devise (and modify) an innovative and balanced plan that provides an equitable system of allocation for an ever-increasing number of patients.
Assuntos
Transplante de Rim , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/organização & administração , Adolescente , Adulto , Cadáver , Criança , Teste de Histocompatibilidade , Humanos , Rim , Transplante de Rim/fisiologia , Transplante de Rim/estatística & dados numéricos , Preservação de Órgãos/métodos , Fatores de Tempo , Estados Unidos , Listas de EsperaRESUMO
Endotoxin has long been implicated as an inducer for the development and progression of gram-negative sepsis. Accordingly, antiendotoxin therapy has been considered one of the major targets for the treatment of sepsis. To investigate the influence of a human immunoglobulin G (IgG) derivative, the 5S fragment of IgG (5S-IgG; Gamma-Venin, Centeon Pharma GmbH, Frankfurt-Niederrad, Germany), on endotoxin release during bacterial proliferation and under antibiotic bactericidal action, time-kill studies were performed by using Escherichia coli ATCC 25922 starting inocula of 10(3), 10(5), and 10(7) CFU/ml with cefotaxime (120 microg/ml) alone and in combination with 5S-IgG (2,100 microg/ml). Samples were collected for bacterial colony count and endotoxin concentration determinations; the area under the free endotoxin concentration curve (AUFEC) was calculated by using the trapezoidal rule. Colony counts showed that cefotaxime had a rapid bactericidal effect because it achieved greater than a 4-log decrease in the numbers of E. coli CFU per milliliter over the first 2 h; the addition of 5S-IgG did not appear to alter the kinetics of killing. Comparison of the AUFEC revealed that the addition of 5S-IgG resulted in a mean reduction of 50, 66, and 27% in the free endotoxin concentration at starting inocula of 10(3), 10(5), and 10(7) CFU/ml, respectively. Moreover, experiments were conducted with a starting inoculum of 10(5) CFU/ml and various amounts of 5S-IgG (2 to 20 mg/ml) to further investigate the dose-effect relation of 5S-IgG on endotoxin release. Decreased AUFECs were observed with increasing concentrations of 5S-IgG, suggesting the dose-dependent antiendotoxin activity of 5S-IgG. Further study is required to investigate the mechanism(s) responsible for this observation, the biological significance of this antiendotoxin activity, and the potential utility of 5S-IgG as an adjuvant therapy in the treatment of gram-negative sepsis.
Assuntos
Escherichia coli/efeitos dos fármacos , Fragmentos de Imunoglobulinas/uso terapêutico , Imunoglobulina G/uso terapêutico , Lipopolissacarídeos/metabolismo , Cefotaxima/uso terapêutico , Cefalosporinas/uso terapêutico , Contagem de Colônia Microbiana , Humanos , Imunoglobulina G/química , Cinética , Testes de Sensibilidade MicrobianaRESUMO
Intraluminal delivery of antisense oligonucleotides to c-myb was assessed following balloon angioplasty in swine peripheral arteries. Successful delivery and intramural persistence of oligonucleotide for over 24 h were demonstrated following angioplasty with hydrogel balloons coated with 32P-labeled antisense. Delivery of fluorescein-labeled antisense demonstrated further localization within the arterial media and intracellularly. Preliminary in vitro studies demonstrated the feasibility of inhibition of porcine lymphocyte proliferation using the murine antisense to c-myb. Twelve iliac or carotid arteries underwent angioplasty with antisense-coated balloons, while the contralateral vessels underwent angioplasty with the same-sized balloons coated with the complementary sense strand. Six to seven days later, dilated arterial segments were surgically isolated. In 10 of 12 vessel pairs, antisense-treated vessels demonstrated less cellular proliferation than did contralateral sense-treated vessels, as assessed by quantitative immunohistochemical staining of proliferating cell nuclear antigen, and smooth muscle cell proliferation was reduced 18% in antisense-treated vessels compared to the contralateral sense-treated vessels (PCNA-positive nuclear area: 7.7 +/- 4.9% vs. 9.3 +/- 5.2%, P < 0.04)-intraluminal delivery of antisense oligonucleotides to c-myb is feasible with a catheter-based system and may reduce smooth muscle cell proliferation following arterial injury.
Assuntos
Angioplastia Coronária com Balão/instrumentação , Doença das Coronárias/tratamento farmacológico , Sistemas de Liberação de Medicamentos/instrumentação , Oligonucleotídeos Antissenso/administração & dosagem , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Transativadores/antagonistas & inibidores , Animais , Autorradiografia , Divisão Celular/efeitos dos fármacos , Doença das Coronárias/patologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/patologia , Estudos de Viabilidade , Feminino , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Microscopia de Fluorescência , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Oligonucleotídeos Antissenso/farmacocinética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-myb , Suínos , Transativadores/metabolismoRESUMO
The Channel balloon is a new local drug-delivery catheter that has the dual capability of high-pressure lesion dilation and low-pressure drug infusion. The purpose of this study was to assess the safety and efficacy of this device in the local delivery of urokinase in the porcine model. Three in vivo protocols were performed in 57 anesthetized swine to assess the safety of Channel balloon use in the coronary vasculature, the pharmacokinetics of local urokinase delivery, and the ability of the catheter to lyse intraluminal thrombus. First, safety studies were performed in 18 coronary vessels in 13 pigs to compare angiographic and histologic changes following use of the Channel balloon with conventional balloon angioplasty. Second, intramural deposition of 123I-labeled urokinase was measured in 24 coronary arteries in 20 pigs to assess the efficiency and technical determinants of urokinase delivery and the time course of intramural drug retention. Finally, an in vivo thrombus model was used in 24 pigs to compare the thrombolytic capacity of local urokinase delivery with the Channel balloon in comparison with conventional urokinase infusion techniques. All balloon inflations and drug infusions with the Channel balloon were well tolerated in all animals without adverse angiographic, hemodynamic, or electrical sequelae. Comparative histologic studies with the Channel balloon demonstrated no additional vessel trauma beyond that seen with conventional balloon angioplasty. Between 0.09 and 0.35% of infused urokinase was intramurally deposited, with intracoronary persistence for at least 5 h. Drug infusion pressure did not significantly affect drug deposition, although larger amounts of urokinase were deposited with larger balloon:artery ratios and higher urokinase concentrations. In comparison to conventional systemic and guiding catheter infusions, local delivery of urokinase with the Channel balloon resulted in higher levels of clot dissolution. These studies have demonstrated safe intracoronary use of the Channel balloon in the porcine model. Local infusion of urokinase with this device results in significant intramural drug deposition that persists for at least 5 h. In comparison with conventional thrombolytic techniques, local urokinase delivery with the Channel balloon may result in enhanced intravascular thrombolysis.
Assuntos
Angioplastia Coronária com Balão/instrumentação , Divisão Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/instrumentação , Fibrinolíticos/administração & dosagem , Músculo Liso Vascular/efeitos dos fármacos , Terapia Trombolítica/instrumentação , Ativador de Plasminogênio Tipo Uroquinase/administração & dosagem , Animais , Desenho de Equipamento , Segurança de Equipamentos , Estudos de Viabilidade , Feminino , Fibrinolíticos/farmacocinética , Artéria Ilíaca/efeitos dos fármacos , Artéria Ilíaca/lesões , Artéria Ilíaca/patologia , Masculino , Músculo Liso Vascular/lesões , Músculo Liso Vascular/patologia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Suínos , Resultado do Tratamento , Túnica Média/efeitos dos fármacos , Túnica Média/lesões , Túnica Média/patologia , Ativador de Plasminogênio Tipo Uroquinase/farmacocinéticaRESUMO
Drug delivery by iontophoresis involves the application of an electric field to move selectively charged drug molecules across biological membranes. The purpose of this study was to assess the efficacy of intravascular iontophoresis in the local delivery of heparin to balloon angioplasty sites by using a recently designed iontophoretic catheter. In vivo heparin iontophoresis was assessed in 33 rats and 21 pigs in four protocols designed to measure the technical determinants of intramural drug deposition, the pharmacokinetics and localization of coronary delivery, and the effect of this technique on platelet deposition following balloon injury. First, iontophoresis of 3H-heparin into the aorta of 33 rats was performed to determine the effects of iontophoretic current, iontophoretic membrane balloon initiation pressure, iontophoresis time, and heparin concentration on intramural drug deposition. Second, iontophoresis of 3H-heparin was performed in 16 porcine coronary arteries to quantitate immediate drug delivery and subsequent wash-out over 24 h. Third, iontophoresis of fluorescent heparin was performed in 8 porcine coronary arteries to define intramural localization of locally delivered drug. Fourth, 111In-labeled platelet deposition was measured 1 h following balloon angioplasty and local iontophoretic heparin delivery in 16 porcine carotid and iliac vessels. Contralateral control vessels that were dilated with the same size balloon and treated with iontophoresis of saline served as controls. Rat aortic studies demonstrated that iontophoresis resulted in 13 times more intramural heparin deposition than passive delivery (passive: 0.3 +/- 0.4 microgram, iontophoresis: 4.6 +/- 1.6 micrograms, P < 0.0004). Iontophoretic membrane balloon inflation pressure had no significant effect on intramural drug deposition, but longer iontophoresis times and higher heparin concentrations resulted in higher levels of intramural heparin (P < 0.05). Porcine coronary studies demonstrated successful intramural deposition of heparin in all arteries without adverse electrical or hemodynamic sequelae, with persistence of the drug for at least 24 h. Localization studies demonstrated immediate deposition of fluorescent heparin in the intima and internal elastic lamina, with subsequent rapid diffusion of the drug into the media. Porcine platelet studies demonstrated that heparin iontophoresis decreased platelet deposition following balloon injury by approximately 66% compared with saline-treated control vessels (heparin-treated: 1.46 +/- 2.51 x 10(8), control: 4.27 +/- 7.02 x 10(8), P = 0.001). This study has demonstrated that local intramural heparin delivery is feasible with an intravascular iontophoretic catheter. Following intracoronary heparin iontophoresis in the porcine model, intramural drug is detected for at least 24 h. Local delivery of heparin with this technique significantly decreases early platelet deposition following balloon injury in peripheral porcine arteries.
Assuntos
Angioplastia Coronária com Balão/instrumentação , Angioplastia com Balão/instrumentação , Anticoagulantes/administração & dosagem , Sistemas de Liberação de Medicamentos/instrumentação , Heparina/administração & dosagem , Iontoforese/instrumentação , Músculo Liso Vascular/efeitos dos fármacos , Animais , Anticoagulantes/farmacocinética , Aorta/efeitos dos fármacos , Aorta/lesões , Aorta/patologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/lesões , Vasos Coronários/patologia , Relação Dose-Resposta a Droga , Tecido Elástico/efeitos dos fármacos , Tecido Elástico/lesões , Tecido Elástico/patologia , Desenho de Equipamento , Heparina/farmacocinética , Masculino , Músculo Liso Vascular/lesões , Músculo Liso Vascular/patologia , Agregação Plaquetária/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Suínos , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/lesões , Túnica Íntima/patologia , Túnica Média/efeitos dos fármacos , Túnica Média/lesões , Túnica Média/patologiaRESUMO
The specific diagnosis of babesiosis, which is caused by the piroplasm Babesia microti, is made by microscopic identification of the organism in Giemsa-stained thin blood smears, detection of babesial antibody in acute-and convalescent-phase sera, or identification of the organism following the injection of patient blood into laboratory animals. Although rapid diagnosis can be made with thin blood smears, parasites are often not visualized early in the course of infection. PCR is a new, rapid diagnostic technique for the detection of Babesia spp. that has not yet been systematically evaluated. We conducted a blinded study of the sensitivity, specificity, and reproducibility of the PCR-based test with patients with babesiosis and a group of asymptomatic subjects residing in a region in southern New England where babesiosis is enzootic. Among 19 patients with recent babesial illness, we found that PCR was as sensitive and specific as the use of Giemsa-stained blood smears and inoculation of hamsters. Among asymptomatic subjects, the PCR result was positive for 3 persons with recent babesial infection and was negative for 41 persons without previous babesial infection. We conclude that the B. microti PCR procedure is sufficiently sensitive, specific, and reproducible for use in the diagnosis of acute babesiosis.
Assuntos
Babesiose/diagnóstico , Babesiose/parasitologia , Parasitemia/diagnóstico , Parasitemia/parasitologia , Parasitologia/métodos , Reação em Cadeia da Polimerase/métodos , Zoonoses/parasitologia , Animais , Sangue/parasitologia , Cricetinae , Erros de Diagnóstico , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Parasitologia/estatística & dados numéricos , Reação em Cadeia da Polimerase/estatística & dados numéricos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Short-term myocardial hibernation of 3 hours resulting from a moderate resting coronary flow reduction has been reproduced in pigs. This study was designed to determine whether any structural changes accompany short-term hibernation caused by a moderate flow reduction maintained for 24 hours and whether any such structural alterations are reversible after reperfusion. METHODS AND RESULTS: A severe left anterior descending coronary artery (LAD) stenosis was created with a reduction of resting flow to approximately 60% of baseline and maintained for 24 hours. Regional coronary flow was measured by a flowmeter; wall thickening was determined by echocardiography, and local metabolic changes were measured. Of 17 pigs, 11 completed the study protocol of 24 hours. The LAD flow was reduced from 0.91 +/- 0.11 to 0.52 +/- 0.13 mL.min-1.g-1, a 43% mean decrease, at 15 minutes after the LAD stenosis and was maintained at 0.56 +/- 0.11 mL.min-1.g-1 at 24 hours. The reduction of regional coronary flow initially produced acute myocardial ischemia, as evidenced by reduced regional wall thickening (from 37.2 +/- 6.9% at baseline to 11.5 +/- 6.8%), regional lactate production (-0.34 +/- 0.28 mumol.g-1.min-1), and a decrease in regional coronary venous pH (from 7.41 +/- 0.035 at baseline to 7.30 +/- 0.030). At 24 hours, the reductions in coronary flow and wall thickening were maintained relatively constant and the rate-pressure product was relatively unchanged, but lactate production ceased and regional H+ concentration normalized, with a tendency toward a further reduction in regional oxygen consumption, from 3.10 +/- 0.90 mL.min-1.100 g-1 at 15 minutes after stenosis to 2.52 +/- 0.95 mL.min-1.100 g-1 at 24 hours (P = .06), indicating metabolic adaptation of the hypoperfused regions. Of 11 pigs, 6 were free of myocardial infarction; 3 had patchy necrosis involving 4%, 5%, and 6% of the area at risk; and 2 other pigs had a few scattered myocytes with necrosis, detected only by light and electron microscopy. Ultrastructural changes consisted of a partial loss of myofibrils and an increase in mitochondria and glycogen deposition. Regional wall thickening recovered 1 week after reperfusion in most pigs, and the ultrastructural changes reverted to normal. CONCLUSIONS: In this pig model, moderately ischemic myocardium undergoes metabolic and structural adaptations but preserves the capacity to recover both functionally and ultrastructurally after reperfusion.
Assuntos
Isquemia Miocárdica/patologia , Isquemia Miocárdica/fisiopatologia , Reperfusão Miocárdica , Citoesqueleto de Actina/patologia , Animais , Circulação Coronária , Doença das Coronárias/patologia , Glicogênio/metabolismo , Mitocôndrias Cardíacas/ultraestrutura , Contração Miocárdica , Miocárdio/metabolismo , Miocárdio/patologia , Necrose , Consumo de Oxigênio , SuínosRESUMO
Over 1,243 organ transplants have been performed at the Hartford Transplant Center over the past two decades. Survival in kidney, heart, liver, and pancreas patients is at or above the national average. Hartford was one of the first centers to use triple immunosuppression, which significantly improved survival in kidney transplantation. For recipients of kidneys from living related donors and cadaveric kidneys, two-year actuarial graft survival has been 98% and 83%, respectively, over the last five years. For heart and liver transplants, two-year survival has been 79% and 67%, respectively. Despite high success rates at most transplant centers, donor organs remain scarce. This problem needs to be addressed through increased cooperative efforts in the health-care community and the general public.
Assuntos
Transplante de Órgãos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Connecticut , Estudos de Avaliação como Assunto , Sobrevivência de Enxerto , Transplante de Coração/estatística & dados numéricos , Humanos , Transplante de Rim/estatística & dados numéricos , Transplante de Fígado/estatística & dados numéricos , Pessoa de Meia-Idade , Transplante de Órgãos/estatística & dados numéricos , Transplante de Pâncreas/estatística & dados numéricosRESUMO
The effects of ofloxacin, clarithromycin, and azithromycin in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF) against Mycobacterium avium-Mycobacterium intracellulare (MAI) were evaluated in an in vitro human macrophage infection model. Treatment of MAI-infected macrophages with GM-CSF alone induced a maximal killing effect at 1000 U/mL, and the potency was increased 100-fold by encapsulating the cytokine within liposomes. Antibiotics were applied at concentrations close to their clinically achievable serum trough and peak levels. Addition of GM-CSF to azithromycin and therapeutic trough concentrations of ofloxacin and clarithromycin was associated with significant (P < .01) augmentation of antimycobacterial activity compared with the effects of the agents alone. However, the enhancement effect by GM-CSF was not seen with therapeutic peak concentrations of ofloxacin and clarithromycin. Thus, GM-CSF may be a useful adjunct in the treatment of MAI infections with azithromycin, clarithromycin, and ofloxacin.
Assuntos
Azitromicina/toxicidade , Claritromicina/toxicidade , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Macrófagos/microbiologia , Complexo Mycobacterium avium/efeitos dos fármacos , Ofloxacino/toxicidade , Células Cultivadas , Relação Dose-Resposta a Droga , Portadores de Fármacos , Interações Medicamentosas , Humanos , Cinética , Lipossomos , Testes de Sensibilidade Microbiana , Complexo Mycobacterium avium/crescimento & desenvolvimento , Proteínas Recombinantes/farmacologia , Fatores de TempoRESUMO
BACKGROUND: Current pharmacological regimens for treating intracoronary thrombus in the cardiac catheterization laboratory generally involve the administration of thrombolytic agents that result in a systemic fibrinolytic state and/or require prolonged arterial drug infusion. The purpose of the present study was to assess a new technique for treating intracoronary thrombus consisting of the local infusion of limited quantities of urokinase with a novel drug delivery device. METHODS AND RESULTS: THe Dispatch coronary infusion catheter is a new local drug delivery system that allows for the prolonged infusion of therapeutic agents at an angioplasty site while distal coronary flow is maintained. Three experimental protocols were performed to determine the in vitro, in vivo, and clinical efficacy of this device. First, in vitro thrombolysis of fresh, porcine thrombus trapped in a 4-mm plastic tube with a 50% constriction and perfused with 20% porcine plasma was measured. Twenty-three thrombi were weighed before and after no treatment (n = 5), "systemic" urokinase administration (n = 4), local infusion of 150,000 U urokinase with a standard end-hole catheter (n = 4), local infusion of saline with the Dispatch catheter (n = 5), and local infusion of 150,000 U urokinase with the Dispatch catheter (n = 5). Second, 25 porcine coronary arteries in 23 pigs were dilated in vivo with conventional balloon angioplasty and then treated with 123I-labeled urokinase that was administered either by the Dispatch catheter (150,000 U; n = 16), intravenous systemic bolus (1,000,000 U; n = 3), guiding catheter infusion (500,000 U; n = 3), or local end-hole catheter infusion (150,000 U; n = 3). All vessels were subsequently harvested to quantify intramural deposition and subsequent washout of urokinase at the angioplasty site. Finally, 19 patients with angiographic evidence of intracoronary thrombus were treated with local urokinase infusion with the Dispatch catheter either before or after balloon angioplasty or directional atherectomy. In vitro studies demonstrated that infusion of urokinase with the Dispatch catheter decreased thrombus weight by 66% compared with no treatment (-25%), "systemic" urokinase administration (25%), end-hole catheter urokinase infusion (32%), or infusion of saline by the Dispatch catheter (32%) (P < or = .005). In vivo studies demonstrated immediate deposition of 0.12% of the urokinase delivered by the Dispatch catheter to the angioplasty site, compared with 0.0007% with systemic bolus, 0.003% with guiding catheter infusion, and 0.007% with local infusion with an end-hole catheter (P < .001). Urokinase deposited by the Dispatch catheter persisted intramurally for at least 5 hours. Patient studies demonstrated reduction of thrombus-containing stenoses and complete disappearance of intracoronary thrombus in all cases in which 150,000 U urokinase was locally infused over 30 minutes. There was no evidence of abrupt closure, distal embolization, or no reflow in any patient. CONCLUSIONS: Local urokinase delivery with the Dispatch catheter can result in rapid and complete intracoronary thrombolysis using substantially less drug than standard thrombolytic techniques. Intramural deposition of drug with this technique creates a local reservoir of urokinase that may provide prolonged thrombolytic activity at the infusion site.
Assuntos
Trombose Coronária/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Ativador de Plasminogênio Tipo Uroquinase/administração & dosagem , Adulto , Idoso , Animais , Cateterismo , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , SuínosRESUMO
BACKGROUND: Conventional balloon angioplasty of intracoronary thrombus is associated with a high incidence of abrupt closure, distal embolization, and no-reflow phenomenon. The purpose of this study was to assess a new technique for treating intracoronary thrombus consisting of the local delivery of urokinase directly to the angioplasty site with urokinase-coated hydrogel balloons. METHODS AND RESULTS: We assessed local urokinase delivery using hydrogel balloons in four protocols. First, we evaluated the pharmacokinetics of urokinase delivery in vitro using 125I-labeled urokinase to measure drug loading onto hydrogel balloons, drug retention by the hydrogel polymer during blood exposure, and drug transfer from the balloon surface to the arterial wall during balloon dilatation. Second, we measured 125I-urokinase washoff from the hydrogel balloon in the intact circulation and intramural drug delivery during in vivo balloon angioplasty in 10 anesthetized New Zealand rabbits. Third, we assessed the effect of local urokinase delivery on 111In-labeled platelet deposition after balloon angioplasty in vivo in 13 porcine carotid or iliac arteries dilated with urokinase-coated balloons and compared them with contralateral control arteries dilated with saline-coated balloons. Finally, we determined the clinical efficacy of urokinase-coated balloons in 15 patients with intracoronary thrombus, including 7 who demonstrated abrupt thrombotic closure after conventional angioplasty. Between 241 and 1509 U urokinase could be loaded onto hydrogel balloons ranging in size from 2 to 8 mm. In vitro and in vivo studies demonstrated that hydrogel balloons absorbed significantly more urokinase and demonstrated less drug wash-off than nonhydrogel balloons (P < .01). Similarly, both in vitro and in vivo studies demonstrated urokinase transfer from the hydrogel to the arterial wall during balloon angioplasty, with greater intramural drug deposition with larger balloons (P < .01). Local urokinase delivery after in vivo porcine angioplasty decreased 111In-labeled platelet deposition by 47% compared with contralateral control vessels (P = .03). Use of urokinase-coated balloons in patients with intracoronary thrombus resulted in thrombus dissolution and reversal of abrupt closure in all cases, without evidence of distal embolization. CONCLUSIONS: With the use of hydrogel-coated balloons, urokinase can be delivered locally to an angioplasty site. This technique decreases platelet deposition after in vivo balloon angioplasty and is efficacious in treating intracoronary thrombus in patients, including those with abrupt thrombotic closure.