RESUMO
OBJECTIVES: As the recipient pool continues to rise, it is vital to conserve donor organs whenever possible. Injured renal allografts continue to be discarded for a variety of reasons, and salvaging potentially useable grafts is of utmost importance. Little information is available on outcomes of salvaged allografts. Here, we present an easily replicable technique to salvage damaged renal allografts using polyglactin mesh. MATERIALS AND METHODS: Polyglactin woven mesh was used to salvage 4 otherwise irreparably injured allografts. In the first case, unidentified extracorporeal shockwave lithotripsy-induced microfractures 2 months before procurement of a deceased-donor kidney led to significant capsular injury. In the second case, rapid recovery of a deceased-donor kidney limited evaluation, and severe capsular rupture was diagnosed after perfusion. In the third case, an anticoagulated pediatric recipient received a living related-donor kidney from his mother, and a biopsy-induced hematoma 2 months posttransplant led to severe capsular denudation. In the fourth case, a pumped kidney from a donor after cardiac death developed severe focal capsular denudation. In each case, a keyhole hilar-sparing incision was made in an industry-standard 12 × 12-inch polyglactin mesh sheet, which was then fitted and sutured in a vest-over-pants method to provide a scaffold for hemostasis and capsular healing. Topical hemostatic agents were added in the first and fourth cases. Patients were followed longitudinally. RESULTS: All allografts were successfully salvaged using our technique, and none developed Page kidney, hydronephrosis, urinoma, or hemorrhage. At last follow-up, recipient 1 had kidney loss 7 years postrepair secondary to chronic allograft nephropathy, recipient 2 was lost to follow-up at 1 year with normal renal function, and recipients 3 and 4 had normal renal function at years 3 and 7 posttransplant. CONCLUSIONS: This simple technique using readily available materials can salvage allografts that would have been potentially explanted or discarded.
Assuntos
Transplante de Rim , Rim/patologia , Telas Cirúrgicas , Aloenxertos , Humanos , Rim/cirurgia , Poliglactina 910RESUMO
Bladder cancer is encountered worldwide having been associated with a host of environmental and lifestyle risk factors. The disease has a male to female prevalence of 3 : 1. This disparity has raised the possibility of the androgen receptor (AR) pathway being involved in the genesis of the disease; indeed, research has shown that AR is involved in and is likely a driver of bladder cancer. Similarly, an inflammatory response has been implicated as a major player in bladder carcinogenesis. Consistent with this concept, recent work on anti-inflammatory glucocorticoid signaling points to a pathway that may impact bladder cancer. The glucocorticoid receptor- (GR-) α isoform has an important role in suppressing inflammatory processes, which may be attenuated by AR in the development of bladder cancer. In addition, a GR isoform that is inhibitory to GRα, GRß, is proinflammatory and has been shown to induce cancer growth. In this paper, we review the evidence of inflammatory mediators and the relationship of AR and GR isoforms as they relate to the propensity for bladder cancer.
RESUMO
The aim of this study was to determine the efficacy of epigallocatechin-3-gallate (EGCG) (Polyphenon E®) in comparison with mitomycin C (MMC) to prevent tumor cell implantation/growth in an animal model of superficial bladder cancer and search for possible mechanism(s) of action. Female Fisher 344 rats were used to study the effects of EGCG and mitomycin C for the prevention of transitional cell tumor implantation (AY-27). Twenty rats served as a control, tumor implantation and saline wash only. Sixty rats were treated with EGCG (100, 200 and 400 µM) intravesically for 60 or 120 min after tumor implantation. Thirty other rats were divided equally and pretreated with 400 µM EGCG or saline for 120 min before tumor initiation. In a separate series of experiments, 30 rats were treated 2 weeks after tumor initiation with saline or EGCG (400 µM). In a different experiment 39 rats were treated with: saline (n=10) EGCG (n=9) 400 µM, MMC (n=10) 0.5 µM, MMC (n=10) 400 µM. Rats were sacrificed 3 weeks following treatment. Gross and histological analyses were performed on the bladders. EGCG and mitomycin C prevented intravesical tumor growth in a concentration- and time-dependent manner. EGCG pretreatment or treatment 2 weeks post tumor implantation did not have therapeutic effects. Molecular modeling suggests that EGCG inhibits urokinase and matrix metalloproteinase-9. EGCG prevents intravesical tumor implantation/growth with a slightly better efficacy than mitomycin C in this experimental model. The data suggest that EGCG lowers proteolytic activity and lowers probability of cancer cell implantation rather than direct cancer cell killing.
Assuntos
Catequina/análogos & derivados , Proliferação de Células/efeitos dos fármacos , Neoplasias Experimentais/tratamento farmacológico , Neoplasias da Bexiga Urinária/tratamento farmacológico , Animais , Catequina/administração & dosagem , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Mitomicina/administração & dosagem , Neoplasias Experimentais/patologia , Ratos , Neoplasias da Bexiga Urinária/patologiaRESUMO
BACKGROUND: We address accusations linking AIDS with testis transplantation performed by a French surgeon, Serge Voronoff (1866-1951), and their implications in the future of animal-to-human organ transplantation. METHODS: Biographical literature on Voronoff and scientific literature on xenotransplantation and the origin of HIV were reviewed. RESULTS: IN the 1920s, Serge Voronoff transplanted testes from primates into humans to revitalize them sexually and physically, making him one of the first surgeons to perform xenotransplantation-transplanting live tissues between species. In recent years, some have postulated that Voronoff's transplants may have caused or contributed to the AIDS epidemic. However, consensus among virologists holds that HIV most likely originated from a chimpanzee virus known as simian immunodeficiency viruses (SIV) which many agree was transmitted to humans during the hunting of primates in the early 1900s. As these accusations have never been addressed, evidence is reviewed which refutes the claims. HIV isolate studies are summarized, which show that SIV was most likely transferred to humans from a chimpanzee species different from those used by Voronoff. Furthermore, literature suggests that Voronoff's experiments were performed in Europe and the United States, not central Africa. CONCLUSIONS: Over 100,000 people await organ transplants, making the prospect of using animal organs to meet demand increasingly favorable. The accusations against Voronoff and others have led to increased concern over cross-species disease transfer. The evidence presented refutes those claims and is used to explain the need for further research into xenotransplantation.
Assuntos
Síndrome da Imunodeficiência Adquirida/história , Vírus da Imunodeficiência Símia/imunologia , Testículo/transplante , Transplante Heterólogo/história , Transplantes/história , Síndrome da Imunodeficiência Adquirida/epidemiologia , Animais , França , Soropositividade para HIV/imunologia , História do Século XIX , História do Século XX , Humanos , MasculinoRESUMO
Lipoxygenases make an impact on every stage of cancer affecting carcinogenesis, metastasis and apoptosis. While there is a rich literature on individual lipoxygenases we lack extensive data on their coexistence and balance in different organs and types of cancer. Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults, characterized by a lack of early warning signs, diverse clinical manifestations, resistance to radiation and chemotherapy. One third of patients will relapse and the 5year survival rate is <10% in cases of metastases. Many drugs are metabolized in the kidneys and might interact with lipoxygenases that are biocatalysts for many endo- and xenobiotics. In the present study, we examined the kidney tissue from healthy individuals and cancer patients by immunohistochemical analysis for the presence of 3 lipoxygenases: 5-LOX, 12S-LOX and 15-LOX-1. Our findings confirmed their coexistence and opposite trends of manifestation in the course of disease with increased 15-LOX-1 and decreased 5- and 12-LOX levels at the onset of cancer reversing with the progressing stage of the disease or the grade of tumor. Unlike other malignancies, there are no biomarkers to individualize RCC management. Modern therapies are using TKI therapy, targeting VEGF and may cause hypertension as a side-effect. 12S-LOX is intertwined with kinases and VEGF and increased secretion of 12S-HETE in urine is known to accompany hypertension. Thus, it may be valuable to probe 12S-LOX activity and monitor its natural metabolite to seek a possible aid in directing the treatment of patients.
Assuntos
Araquidonato 12-Lipoxigenase/metabolismo , Araquidonato 15-Lipoxigenase/metabolismo , Araquidonato 5-Lipoxigenase/metabolismo , Carcinoma Papilar/metabolismo , Carcinoma de Células Renais/metabolismo , Neoplasias Renais/metabolismo , Carcinoma Papilar/patologia , Carcinoma de Células Renais/patologia , Estudos de Casos e Controles , Feminino , Humanos , Neoplasias Renais/patologia , Masculino , Valores de ReferênciaRESUMO
Prostate anatomy has been the subject of controversy for 200 years. In the 19th and early 20th centuries, lobar anatomy was accepted. Beginning in 1968 and for the next 25 years, John E. McNeal presented his view of prostate anatomy in terms of 4 anatomic zones. The transition zone was introduced in 1978 as the site of development of benign prostatic hyperplasia. This review was undertaken to describe the evolution of McNeal's anatomic concepts.
Assuntos
Próstata/anatomia & histologia , Humanos , MasculinoRESUMO
PURPOSE: Mitomycin C (Novaplus®) is often instilled intravesically in the postoperative period to prevent tumor cell implantation/regrowth after transurethral tumor resection. In an earlier study EGCG prevented tumor cell implantation/growth in an experimental bladder tumor model simulating clinical transurethral bladder resection. We compared the efficacy of EGCG (Polyphenon E®) to that of mitomycin C to prevent tumor cell implantation/growth in this model. MATERIALS AND METHODS: Mitomycin C and EGCG were studied for their in vitro and in vivo effects. The AY-27 rat urothelial tumor cell line was used for in vitro and in vivo studies. In vitro cell viability studies included trypan blue exclusion, MTT proliferation assay and clonal growth assay. Fischer 344 female rats were used for intravesical tumor implantation/growth assay using an electrocautery injury model. Tumor growth in vivo was assessed in controls treated with phosphate buffered saline and in bladders treated with mitomycin C or EGCG by standard histological techniques using hematoxylin and eosin 4 weeks after injury. RESULTS: Mitomycin C and EGCG showed cytotoxicity on all in vitro assays. They were equivalent for preventing intravesical tumor growth. CONCLUSIONS: EGCG prevents intravesical tumor growth with efficacy equivalent to that of mitomycin C in this experimental model.
Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Anticarcinógenos/uso terapêutico , Catequina/análogos & derivados , Mitomicina/uso terapêutico , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Animais , Antibióticos Antineoplásicos/farmacologia , Anticarcinógenos/farmacologia , Catequina/farmacologia , Catequina/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Mitomicina/farmacologia , Ratos , Ratos Endogâmicos F344RESUMO
PURPOSE: We evaluated the comparative effects of intraprostatic injection of cobra cardiotoxin D and botulinum toxin type A on prostate structure in the rat model. MATERIALS AND METHODS: A total of 18 Sprague-Dawley® rats weighing 500 to 600 gm received a single 0.1 ml injection of saline (6), botulinum toxin type A (6) or the cardiotoxin D (6) component of cobra (Naja naja atra) toxin in the right and left ventral lobes of the prostate. At 14 days the rats were sacrificed. The prostate glands were harvested, weighed and processed for immunohistochemical and morphological studies. RESULTS: Prostate glands injected with cardiotoxin D showed significantly decreased weight compared to that of prostates injected with botulinum toxin type A and the saline control. Prostatic atrophy in the glandular component with flattening of the epithelial lining was seen histologically in rats that received botulinum toxin and cardiotoxin D. Each group injected with cardiotoxin D and botulinum toxin showed a significant increase in the number of apoptotic cells compared with controls while only the botulinum toxin group showed a significant increase in the number of proliferating cells. Only rats injected with botulinum toxin had body weight loss. CONCLUSIONS: Our study shows that intraprostatic injection of cobra cardiotoxin D induces prostatic atrophy and leads to a decrease in prostatic weight greater than that of intraprostatic injection of botulinum toxin type A. No systemic effects, such as decreased body weight, were noted after cardiotoxin D injection. Further studies are warranted but the statistically significant decrease in the number of proliferating cells implies a prolonged effect of cardiotoxin D.
Assuntos
Proteínas Cardiotóxicas de Elapídeos/farmacologia , Próstata/efeitos dos fármacos , Próstata/patologia , Animais , Atrofia/induzido quimicamente , Toxinas Botulínicas Tipo A/administração & dosagem , Toxinas Botulínicas Tipo A/farmacologia , Proteínas Cardiotóxicas de Elapídeos/administração & dosagem , Injeções , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Civilian and military trauma patients consist of a disproportional number of young people, causing a considerable burden to society in terms of disability and premature death. Hemorrhage is a leading cause of mortality in this group of patients and the novel methods to reduce bleeding would be welcomed. Management of bleeding following major trauma includes hemostatic agents that offer effective clotting. However a very limited number of agents control secondary bleeding triggered by lysis of the clot. Fibrinolysis depends on the balance between tissue plasminogen activator (tPA), activating plasminogen to plasmin initiating fibrinolysis, and plasminogen activator inhibitor type 1 (PAI-1) inhibiting tPA and preventing lysis. The drugs available on the market that prevent the activation of plasminogen have been used successfully, but have some side effects and limited efficacy for the control of localized bleeding in the surgical setting. Inhibitors of tPA, initiator of clot fibrinolysis, have not yet found their way into the clinical arena. Plasminogen activator inhibitor-1, the major specific inhibitor of tPA, can be used to limit fibrinolysis. Unfortunately, PAI-1 has a short half-life of approximately 2 h and is rapidly converted to the latent form. A recombinant PAI-1 with very long half-life developed in our laboratory (a two-point mutant, VLHL PAI-1, half-life over 700 h) has clinical potential as an agent to promote hemostasis in several scenarios including surgical injury, trauma, and PAI-1 deficiency. Here we report testing of VLHL PAI-1 as a potent inactivator of fibrinolysis reducing total blood loss while applied systemically or topically in experimental animals. The very long half-life of VLHL PAI-1 may provide an advantage in the important physiological mechanism to protect clots from premature dissolution, when applied topically or systemically to prevent excessive bleeding in the surgical and trauma setting and possibly in PAI-1 deficient patients.
Assuntos
Antifibrinolíticos/administração & dosagem , Antifibrinolíticos/uso terapêutico , Fibrinólise/efeitos dos fármacos , Hemorragia/tratamento farmacológico , Inibidor 1 de Ativador de Plasminogênio/administração & dosagem , Inibidor 1 de Ativador de Plasminogênio/uso terapêutico , Administração Tópica , Animais , Hemostáticos , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mutação , Inibidor 1 de Ativador de Plasminogênio/genética , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/uso terapêuticoRESUMO
OBJECTIVE: To investigate the potential for the future clinical use of a very long half-life plasminogen activator inhibitor type 1 (VLHL PAI-1) as a haemostatic agent. MATERIALS AND METHODS: We developed a VLHL PAI-1 (half-life >700 h) recombinant mutant of PAI-1 and assessed VLHL PAI-1 for its ability to inhibit fibrinolysis in vitro using human, rabbit, mouse and rat blood. Fibrin clot lysis time, monitored by thromboelastometry, was determined at various concentrations of VLHL PAI-1. Also, we determined total bleeding time and total blood loss of control, VLHL PAI-1-, tissue-type plasminogen activator (tPA)- and tPA + VLHL PAI-1-treated mice. RESULTS: Using a thromboelastometer, mouse blood was most similar to human blood in its coagulation and fibrinolytic characteristics. We evaluated the affect of VLHL PAI-1 on haemostasis using the mouse model and showed that VLHL PAI-1 is an effective inhibitor of fibrin clot degradation. It reduced time of bleeding and total blood loss. CONCLUSION: VLHL PAI-1 may provide an important physiological mechanism to protect clots from premature dissolution in surgical and trauma settings.
Assuntos
Hemorragia/prevenção & controle , Hemostáticos/uso terapêutico , Inibidor 1 de Ativador de Plasminogênio/uso terapêutico , Animais , Coagulação Sanguínea/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Fibroepthelial polyps are uniformly benign tumors of the collecting system which may cause obstruction of an affected renal unit. We present a unique case of a 34-year-old male with a solitary functioning kidney who presented with flank pain and renal insufficiency. Radiographic and ureteroscopic evaluation revealed ureteral obstruction due to extensive polyps. After ureteral stenting and normalization of renal function, successful polyp excisions were performed laparoscopically through a ureterotomy. The pathology revealed benign fibroepithelial polyps. The patient remained asymptomatic until 3 years later when ureteroscopy performed for a calculus revealed a widely patent lumen free of polyps. To our knowledge, this is the first published report of a long term follow up after laparoscopic resection of extensive ureteral fibroepithelial polyps.
Assuntos
Laparoscopia/métodos , Neoplasias Fibroepiteliais/cirurgia , Pólipos/cirurgia , Neoplasias Ureterais/cirurgia , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Adulto , Diagnóstico Diferencial , Seguimentos , Humanos , Masculino , Neoplasias Fibroepiteliais/diagnóstico por imagem , Pólipos/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Neoplasias Ureterais/diagnóstico por imagem , UrografiaRESUMO
Patients with defective plasminogen activator inhibitor protein (PAI-1) or with PAI-1 deficiency can experience hemorrhage as a result of a hyperfibrinolysis. In these patients, a normal thrombus forms, but endogenous lysis is unchecked as tissue plasminogen activator is unopposed. Treatment includes anti-fibrinolytic agents, including oral tranexamic acid. Another treatment option is the administration of PAI-1, but this serpin rapidly inactivates itself. We have developed a mutant plasminogen activator inhibitor with a very long half life (VLHL PAI-1, t1/2>700 h). Here we investigate VLHL PAI-1 effects in the blood of PAI-1 deficient mice, as a model of human disease. Using a thrombelastograph, we found that blood clots of PAI-1 knockout mice were lysed much more quickly than wild type mice. Additionally, blood clots had less shear elastic modulus strength than clots of normal animals. VLHL PAI-1 treatment of PAI-1 deficient mice extended or prevented thrombus lysis and increased clot strength in a concentration dependent fashion. These two parameters determine the extent of thrombus growth and regression; thus, further testing is anticipated to confirm the effectiveness of plasminogen activator inhibitor with a very long half life in an in vivo model and we hope that this protein can be effective in human PAI-1 deficiency disorder.
Assuntos
Inibidor 1 de Ativador de Plasminogênio/sangue , Inibidor 1 de Ativador de Plasminogênio/deficiência , Terapia Trombolítica , Trombose/sangue , Animais , Meia-Vida , Humanos , Insetos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Inibidor 1 de Ativador de Plasminogênio/genética , Inibidor 1 de Ativador de Plasminogênio/uso terapêutico , Inativadores de Plasminogênio/sangue , Inativadores de Plasminogênio/deficiência , Inativadores de Plasminogênio/uso terapêutico , Terapia Trombolítica/métodos , Trombose/tratamento farmacológicoRESUMO
PURPOSE: Tumor spillage from bladder perforation during transurethral bladder tumor resection or cystectomy risks seeding the peritoneum with transitional cell carcinoma. We determined the lowest effective mitomycin C dose to prevent tumor implantation and the potential efficacy of delayed therapy. Additionally, we investigated the effect of tumor debulking combined with intraperitoneal mitomycin C. MATERIALS AND METHODS: Using our established murine model of intraperitoneal transitional cell carcinoma implantation mitomycin C was instilled at decreasing concentrations to find the lowest effective dose. To evaluate the effectiveness of delayed therapy mitomycin C was administered on day 3 or 7 after tumor implantation. Finally, surgical debulking of established tumors with or without mitomycin C was performed. RESULTS: All control animals had disseminated carcinomatosis. The lowest effective intraperitoneal mitomycin C dose to prevent implantation was 0.3125 mg/m(2). Administration of mitomycin C on day 3 after instillation resulted in tumor-free status in 50% of the animals, although no rats were tumor-free when treated on day 7. Tumor debulking only for established disease cured 40% of the animals, whereas debulking combined with mitomycin C had a 100% cure rate. CONCLUSIONS: Intraperitoneal mitomycin C prevents tumor growth after transitional cell carcinoma implantation. Delayed therapy is not as effective as immediate treatment but cure is still possible, particularly when combined with surgical debulking, in a rat model.
Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Carcinoma de Células de Transição/tratamento farmacológico , Carcinoma de Células de Transição/prevenção & controle , Mitomicina/uso terapêutico , Inoculação de Neoplasia , Animais , Carcinoma de Células de Transição/cirurgia , Modelos Animais de Doenças , Ratos , Ratos Endogâmicos F344RESUMO
BACKGROUND: C/EBPalpha is a critical mediator of terminal differentiation and a tumor suppressor through its strong antiproliferative actions on cell cycle regulatory proteins. C/EBPalpha also appears to regulate androgen receptor (AR) AR signaling. There, is a paucity of information on the expression and sub-cellular localization of C/EBPalpha in normal mouse and human prostate and in prostate cancer. METHODS: Immunohistochemistry of tissues including tissue arrays, quantitative polymerase chain reaction and mRNA expression database mining. RESULTS: In the mouse prostate epithelium, C/EBPalpha was present at 1 week postnatal localized in the cytosol, began to show nuclear localization at 8 weeks and continued to show prominent nuclear expression at 10 weeks and beyond; C/EBPalpha mRNA was expressed at all ages. In humans, C/EBPalpha showed prominent nuclear localization from peripubescence up to middle age but was sequestered in the cytosol in older individuals; the mRNA level for C/EBPalpha remained essentially unchanged. Most prostate adenocarcinomas expressed a range of levels of C/EBPalpha mRNA and protein that were relatively high in metastatic tumors in a manner that correlated with AR expression; however, most cells showed C/EBPalpha sequestered in the cytosol. CONCLUSIONS: Temporal changes in sub-cellular localization of C/EBPalpha are consistent with a role in prostate differentiation and as a prostate tumor suppressor; the cytoplasmic sequestration of C/EBPalpha, unique to older human prostates, is arguably a permissive condition for the greater frequency of proliferative disorders of the prostate. In malignant prostate C/EBPalpha may be available to regulate AR signaling through transient changes in its sub-cellular localization.
Assuntos
Adenocarcinoma/metabolismo , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Próstata/crescimento & desenvolvimento , Próstata/fisiologia , Neoplasias da Próstata/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma/fisiopatologia , Animais , Núcleo Celular/metabolismo , Citosol/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos , Análise de Sequência com Séries de Oligonucleotídeos , Próstata/patologia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/fisiopatologia , RNA Mensageiro/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais/fisiologiaRESUMO
Plasminogen activator inhibitor-1 (PAI-1) is the major specific inhibitor of tissue-type plasminogen activator (tPA) which mediates fibrin clot lysis through activation of plasminogen. Wild-type-PAI-1 (wPAI-1) is rapidly converted to the latent form (half-life of approximately 2 h) and loses its ability to inhibit tPA. We developed a very long half-life PAI-1 (VLHL PAI-1), a recombinant protein with a half-life >700 h compared with wPAI-1. In this study, VLHL PAI-1 was assessed for its ability to inhibit clot lysis in vitro. Clot formation was initiated in normal plasma supplemented with tPA by the addition of either tissue factor or human recombinant FVIIa. Clot lysis time, monitored turbidimetrically in a microtiter plate reader, was determined at various concentrations of wPAI-1 and VLHL PAI-1. Both wPAI-1 and VLHL PAI-1 caused a significant increase in clot lysis time, although the latter was somewhat less effective at lower concentrations. The VLHL PAI-1, but not wPAI-1, maintained its anti-fibrinolytic activity after preincubation overnight at 37 degrees. These studies demonstrate that VLHL PAI-1 is an effective inhibitor of fibrin clot degradation. Due to the high stability of VLHL PAI-1 compared with wPAI-1, this novel inhibitor of tPA-mediated fibrinolysis may have therapeutic applications for treating surgical and trauma patients when used directly or in conjunction with the procoagulant recombinant FVIIa.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Fibrina/metabolismo , Fibrinólise/efeitos dos fármacos , Inibidor 1 de Ativador de Plasminogênio/farmacologia , Proteínas Recombinantes/farmacologia , Ativador de Plasminogênio Tecidual/farmacologia , Eletroforese em Gel de Poliacrilamida , Meia-Vida , Humanos , Inibidor 1 de Ativador de Plasminogênio/isolamento & purificação , Espectrofotometria , TermodinâmicaRESUMO
PURPOSE: We evaluated the efficacy of intravesical aminolevulinic acid (delta-aminolevulinic acid hydrochloride) (Frontier Scientific, Logan, Utah) and photodynamic therapy for the removal of small intestinal mucosa in augmented bladders in a rat model. MATERIALS AND METHODS: Enterocystoplasty was performed in 70 female rats using a patch of terminal ileum. A total of 28 were used to determine the pharmacokinetics (0.3, 0.6 and 0.9 M) and dwell time (30, 60 and 90 minutes) of intravesically administered aminolevulinic acid to optimize intestinal mucosal absorption and minimize bladder mucosal absorption. The remaining augmented rats were treated with intravesical photodynamic therapy at light doses of 75, 100 and 125 J. Ileal and bladder tissues were evaluated by light microscopy. Cystometric studies to evaluate bladder volume were measured before and after photodynamic therapy. RESULTS: The concentration of 0.3 M aminolevulinic acid with a dwell time of 30 minutes resulted in an average +/- SE bowel-to-bladder concentration of 2,156 +/- 269/749 +/- 62 ng/gm (ratio 2.9:1). After photodynamic therapy histology revealed uniform ablation and replacement of the intestinal mucosa with urothelium and minimal damage to the bladder wall at all light doses. Bladder cystometry revealed no significant change in bladder capacity after photodynamic therapy. CONCLUSIONS: In the rat model intravesical aminolevulinic acid and photodynamic therapy resulted in the replacement of intestinal mucosa with urothelium, leaving the underlying muscular layer intact. This could potentially be a viable option for patients with a preexisting bladder augment.
Assuntos
Ácido Aminolevulínico/administração & dosagem , Mucosa Intestinal/efeitos dos fármacos , Fotoquimioterapia , Fármacos Fotossensibilizantes/administração & dosagem , Bexiga Urinária/cirurgia , Urotélio/crescimento & desenvolvimento , Administração Intravesical , Ácido Aminolevulínico/farmacocinética , Animais , Feminino , Íleo/citologia , Íleo/transplante , Mucosa Intestinal/citologia , Mucosa Intestinal/transplante , Fármacos Fotossensibilizantes/farmacocinética , Ratos , Ratos Endogâmicos F344 , Bexiga Urinária/citologiaRESUMO
Plasminogen activator inhibitor (PAI-1) is an anticancer agent that inhibits plasmin driven proteolysis, limiting angiogenesis and metastasis. In low concentrations it could induce cancer cell motility by interacting with urokinase (uPA), its receptor (uPAR), vitronectin and integrins. Active PAI-1 binds to uPA forming a complex with uPAR, while the latent form of PAI-1 does not. PAI-1 is found in both forms in the circulation. It is not clear which form acts as an anticancer agent and how it interacts with malignant cells. To investigate how these forms reduce angiogenesis or metastasis, we have created PAI-1 cysteine mutants in the active conformation (VLHL PAI-1) with an extended half-life that reaches approximately 700 h and its R369A mutant, which has an active conformation but cannot bind to uPA (VLHLNS PAI-1). Both VLHL PAI-1s convert into the latent form when treated with a reducing agent (DTT) that breaks disulfide bridges. Unexpectedly, during routine investigation of LnCAP cell proliferation, we have found that cells detach from the culture vessels regardless of PAI-1 conformation or activity. Further investigation showed that treatment of cancer cells with VLHL PAI-1 downregulated nucleophosmin, while all forms of PAI-1 downregulated fortilin. These two proteins are implicated in important cellular processes (cell growth, cell cycle, malignant transformation). This suggests that PAI-1, in addition to its well-known anticancer properties, plays an important role in cell signaling. We hope that by exploring PAI-1's structure and function we might be able to understand and separate the different effects of PAI-1 on cancer cells and develop more effective therapeutic strategies in cancer treatment.
Assuntos
Biomarcadores Tumorais/metabolismo , Movimento Celular/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Inibidor 1 de Ativador de Plasminogênio/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Sequência de Aminoácidos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação para Baixo , Meia-Vida , Humanos , Masculino , Modelos Moleculares , Peso Molecular , Nucleofosmina , Inibidor 1 de Ativador de Plasminogênio/química , Inibidor 1 de Ativador de Plasminogênio/genética , Conformação Proteica , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Proteína Tumoral 1 Controlada por TraduçãoRESUMO
Photodynamic therapy (PDT) has slowly found its place in the treatment of human disease. Currently, photodynamic therapy is being explored as a treatment option for localized prostate cancer. PDT for the treatment of prostate cancer will require ablation of both malignant and non-malignant glandular epithelium. Ablation of both malignant and normal epithelium adds a new treatment dimension since traditionally PDT has not targeted normal epithelial tissue. PDT for prostate cancer as currently envisioned will present challenges in terms of in situ monitoring of light, drug concentration, [Formula: see text] levels and biologic endpoints. The introduction of vascular-targeted photosensitizers fundamentally alters the traditional axioms for successful PDT treatment by obviating the need for "selective" tumor localization. Should clinical trials demonstrate the utility of this approach, patients with organ-confined disease will benefit.