Does the association of tacrolimus and mycophenolate mofetil change the healing of the abdominal wall? study in rats submitted to ischemia and kidney reperfusion / A associação de tacrolimus e micofenolato mofetil altera a cicatrização da parede abdominal? estudo em ratos submetidos à isquemia e reperfusão renal

ABSTRACT Background: Tacrolimus and mycophenolate mofetil are immunosuppressive agents widely used on the postoperative period of the transplants. Aim: To evaluate the influence of the association of them on the abdominal wall healing in rats. Methods: Thirty-six Wistar rats were randomly assigned in three groups of 12. On the early postoperative period, four of the control group and three of the experimental groups died. The three groups were nominated as follow: control group (GC, n=8); group I (GI, n=11, standard operation, mycophenolate mofetil and tacrolimus); group II (GII, n=10, standard operation, mycophenolate mofetil and tacrolimus). The standard operation consisted of right total nephrectomy and 20 min ischemia of the left kidney followed by reperfusion. Both NaCl 0.9% and the immunosuppressive agents were administered starting on the first postoperative day and continuing daily until the day of death on the 14th day. On the day of their deaths, two strips of the anterior abdominal wall were collected and submitted to breaking strength measurement and histological examination. Results: There were no significant differences in wound infection rates (p=0,175), in the breaking strength measurement and in the histological examination among the three groups. Conclusion: The combination of the immunosuppressive agents used in the study associated with renal ischemia and reperfusion does not interfere in the abdominal wall healing of rats.

RESUMO Racional: O tacrolimus e o micofenolato mofetil são imunossupressores amplamente utilizados no pós-operatório dos transplantes de órgãos. Objetivo: Avaliar os efeitos deles sobre a cicatrização da parede abdominal em ratos. Métodos: Foram utilizados 36 ratos Wistar, distribuídos aleatoriamente em três grupos de 12. No pós-operatório imediato, quatro do grupo controle e três do grupo experimentação morreram. Os três grupos receberam as seguintes denominações: grupo controle (GC, n=8); grupo I (GI, n=11, operação-padrão, micofenolato mofetil e tacrolimus); grupo II (GII, n=10, operação-padrão, micofenolato mofetil e tacrolimus). A operação-padrão consistiu de nefrectomia total à direita, isquemia durante 20 min seguida de reperfusão do rim esquerdo. Solução de NaCl 0,9% e micofenolato mofetil + tracolimus foram administradas a partir do 1° dia do pós-operatório e mantidas até o dia do sacrifício dos animais, no 14° dia. Na data do sacrifício, foram retirados dois fragmentos da parede abdominal para análise da resistência à ruptura e exame histológico. Resultados: Não houve diferença estatisticamente significativa no índice de infecção de ferida operatória (p=0,175), nos valores de resistência de ruptura e nos achados histopatológicos entre os três grupos de animais. Conclusão: Os esquemas de imunossupressão empregados associados ao fenômeno da isquemia-reperfusão renal não induzem fraqueza significativa da cicatriz da parede abdominal em ratos no 14° dia de pós-operatório.

Evaluation of the use of tacrolimus ointment for the prevention of hypertrophic scars in experimental model

Abstract BACKGROUND: Tacrolimus, for its activity on modulation of collagen production and fibroblast activity, may have a role in the prevention of hypertrophic scars. OBJECTIVES: Evaluate macroscopic, microscopic, metabolic, laboratory effects and side effects of the use of topical tacrolimus ointment, in different concentrations, in the prevention of hypertrophic scars. METHODS: Twenty-two rabbits were submitted to the excision of 2 fragments of 1 cm of each ear, 4 cm apart, down to cartilage. The left ear of the animals was standardized as control and Vaseline applied twice a day. The right ear received tacrolimus ointment, at concentrations of 0.1% on the upper wound and 0.03% on the lower wound, also applied twice a day. Macroscopic, microscopic, laboratory criteria and the animals' weight were evaluated after 30 days of the experiment. RESULTS: Wounds treated with tacrolimus, at concentrations of 0.1% and 0.03%, when compared to control, showed a lower average degree of thickening (p = 0.048 and p <0.001, respectively). The average of scar thickness and lymphocyte, neutrophil and eosinophil concentrations are lower in the treated wounds compared to the control (p <0.001, p=0.022, p=0.007, p=0.044, respectively). The mean concentration of lymphocytes is lower in wounds treated with a higher concentration of the drug (p=0.01). STUDY LIMITATIONS: experiment lasted only 30 days. CONCLUSIONS: Tacrolimus at the 2 concentrations evaluated reduced the severity of inflammatory changes and positively altered the macroscopic aspect of the scar in the short term. Its use was shown to be safe, with no evidence of systemic or local adverse effects.

Antifungal activities of tacrolimus in combination with antifungal agents against fluconazole-susceptible and fluconazole-resistant Trichosporon asahii isolates

ABSTRACT The antifungal activity of tacrolimus in combination with antifungal agents against different fungal species has been previously reported. Here we report the in vitro interactions between tacrolimus and amphotericin B, fluconazole, itraconazole, and caspofungin against 30 clinical isolates of both fluconazole-susceptible and fluconazole-resistant Trichosporon asahii. For these analyses, we used the broth microdilution method based on the M27-A3 technique and checkerboard microdilution method. Tacrolimus showed no activity against T. asahii strains (minimal inhibitory concentrations, MICs > 64.0 µg mL−1). However, a larger synergistic interaction was observed by the combinations tacrolimus + amphotericin B (96.67%) and tacrolimus + caspofungin (73.33%) against fluconazole-susceptible isolates. Combinations with azole antifungal agents resulted in low rates of synergism for this group (fluconazole + tacrolimus = 40% and itraconazole + tacrolimus = 10%). Antagonistic interactions were not observed. For the fluconazole-resistant T. asahii group, all tested combinations showed indifferent interactions. The synergism showed against fluconazole-susceptible T. asahii isolates suggests that the potential antifungal activity of tacrolimus deserves in vivo experimental investigation, notably, the combination of tacrolimus with amphotericin B or caspofungin.

Synergistic effects of tacrolimus and azole antifungal compounds in fluconazole-susceptible and fluconazole-resistant Candida glabrata isolates

In vitro interaction between tacrolimus (FK506) and four azoles (fluconazole, ketoconazole, itraconazole and voriconazole) against thirty clinical isolates of both fluconazole susceptible and -resistant Candida glabrata were evaluated by the checkerboard microdilution method. Synergistic, indifferent or antagonism interactions were found for combinations of the antifungal agents and FK506. A larger synergistic effect was observed for the combinations of FK506 with itraconazole and voriconazole (43%), followed by that of the combination with ketoconazole (37%), against fluconazole-susceptible isolates. For fluconazole-resistant C. glabrata, a higher synergistic effect was obtained from FK506 combined with ketoconazole (77%), itraconazole (73%), voriconazole (63%) and fluconazole (60%). The synergisms that we observed in vitro, notably against fluconazole-resistant C. glabrata isolates, are promising and warrant further analysis of their applications in experimental in vivo studies.

Analysis of the histology of the scar bladder and biochemical parameters of rats with a solitary kidney undergoing immunosuppression with tacrolimus

PURPOSE: To evaluate bladder histology in healing and biochemical analysis of rats with single kidney in ischemia/reperfusion, treated with tacrolimus. METHODS: Fifty rats randomized into five groups. Three rats died in surgery, 47 rats divided in groups: Control (non-operated, n=10), Sham (operated without drugs, n=8), T1 (operated + tacrolimus 1mg/kg, n=10), T2 (operated + tacrolimus 0.1 mg/kg, n=10), T3 (operated + tacrolimus 10mg/kg, n=9). The surgery was: laparotomy, right nephrectomy, left kidney ischemia/reperfusion, cystotomy followed by bladder suture. After that, rats were submited to gavage daily (Control and Sham with saline solution. T1, T2, T3 with tacrolimus in doses already mentioned). On the 14th day, after death induction, cystectomy was performed and bladder was histologicaly analysed. The serum urea, creatinine and tacrolimus were analysed too. RESULTS: There was difference in serum tacrolimus in T3 compared to the other groups (p<0.05). There was higher doses of creatinine in T3 group and higher urea in groups with tacrolimus. There were significant differences among all histologic variables comparing groups with and without tacrolimus (p<0.05). CONCLUSION: Tacrolimus associated with ischemia/reperfusion is nephrotoxic, suppresses inflammation and seems to delay the healing bladder. .

Comparative efficacy of topical mometasone furoate 0.1% cream vs topical tacrolimus 0.03% ointment in the treatment of atopic dermatitis

To compare the efficacy of mometasone furoate and tacrolimus in the treatment of atopic dermatitis. Sixty patients of atopic dermatitis were treated with mometasone furoate 0.1% [n=30] and tacrolimus 0.03% [n=30]. Both treatments were applied twice daily for 12 weeks. Patients were followed up monthly. The disease severity assessed by SCORAD index. A 4-point scale was used to measure the level of response to treatment. Before treatment the respective mean SCORAD was 30.57 +/- 13.62 and 30.90 +/- 17.17 in group A and B and at the end of treatment decreased to 11.87 +/- 12.04 and 11.20 +/- 13.85, respectively [p>0.05]. Percent reduction of severity from baseline to final follow-up was 69.20 +/- 23.41 in group A and 74.77 +/- 23.30 in group B [p=0.360]. At final follow-up 56.7% of group A and 63.3% of group B achieved excellent response, 13.3% of group A and 16.7% of group B achieved good response. We conclude that both treatments, mometasone furoate and tacrolimus, are effective in the treatment of atopic dermatitis

[Neurotrophic effect of tacrolimus on pyramidal cells of CA1 region of hippocampus following transient global ischemia/reperfusion in male wistar rat]

Cerebral ischemia is known as a major problem in the world. Reperfusion following the ischemia ultimately leads to programmed cell death or apoptosis. Specific regions of the brain and certain types of neurons are more susceptible to cerebral ischemia, such as pyramidal neurons of CA1 region of hippocampus. Recently, using of immunophilin ligands has been considered to be a potential and appropriate strategy for neuroprotective and neurogenitor activity. Up to now, the right time of injection for providing the suitable effect on pyramidal cells of CA1 has not been assessed precisely. In this study, the neurotrophic effects of tacrolimus on CA1 cells were studied on 40 male Wistar rats in 8 experimental groups. Ischemia model was induced by ligation of bilateral common carotid arteries. For detecting the most appropriate time for 6mg/kg, Injection was done via single and double doses with intervals of 6, 24, 48 and hours. The repeated doses of 6mg/kg with interval of 48 hours are the suitable dose and time of injection. It seems that tacrolimus can be an appropriate strategy as a neurotrophic drug for treating brain ischemia

Ação do tacrolimus na pancreatite aguda experimental induzida pela arginina / Action of tacrolimus in arginine induced experimental acute pancreatitis

OBJETIVO: verificar se o tacrolimus administrado em ratos, em vigência de pancreatite induzida pela L-Arginina, interfere nos níveis séricos da amilase e glicose e no padrão histológico do parênquima pancreático. MÉTODOS: quarenta ratos Wistar foram distribuídos em quatro grupos com 10 ratos cada. Grupo controle (C), grupo tacrolimus (T), grupo pancreatite (P) e grupo pancreatite-tacrolimus (PT). Foram avaliados os níveis séricos de amilase, glicose e tacrolimus e feitas avaliações histológicas do pâncreas, A indução de pancreatite foi feita pela inoculação de L-Arginina na dose de 500mg/100g de peso corporal por via intraperitoneal e o tratamento com tacrolimus na dose de 1ìg/kg por via subcutânea durante quatro dias. RESULTADOS: a amilasemia estava mais elevada (p=0,0000) nos grupos PT, T e P do que no grupo controle. A média do grupo PT foi maior (p=0,0009) que a do grupo T, mas não diferiu (p=0,6802) da média do grupo P. Entre os grupos P e T não houve diferença (p=0,2568). Não houve diferença nas médias de glicemia entre os grupos (p=0,4920) e os níveis séricos de tacrolimus foram similares nos grupos PT e T (p=0,7112). Não ocorreram alterações histológicas nos grupos T e C e não ocorreu hemorragia no pâncreas dos ratos dos grupos P e PT. No grupo P, em 30 por cento não se observou edema, em 20 por cento observou-se a forma leve e em 50 por cento, a moderada; quanto à infiltração inflamatória, em 80 por cento moderada e em 20 por cento não ocorreu, e a atrofia do parênquima foi de 60 por cento moderada e 40 por cento acentuada. No grupo PT, houve ocorrência de edema, infiltração inflamatória e atrofia do pâncreas em todos os ratos. CONCLUSÃO: o tratamento pelo tacrolimus induziu aumento nos níveis séricos de amilase em ratos normais, não alterou a glicemia nem o padrão histológico do parênquima pancreático. Na vigência de pancreatite induzida pela L-Arginina o tacrolimus induziu edema, infiltração inflamatória e atrofia com maior gravidade no parênquima pancreático.

OBJECTIVE: To determine whether tacrolimus administered to rats, in the presence of pancreatitis induced by L-Arginine, interferes with the serum levels of amylase and glucose and the histological pattern of the pancreatic parenchyma. METHODS: Forty Wistar rats were divided into four groups with 10 rats each: control group (C), tacrolimus group (T), pancreatitis group (P) and pancreatitis-tacrolimus group (PT). We evaluated serum levels of amylase, glucose, and tacrolimus and made histological assessments of the pancreas. Induction of pancreatitis was made by inoculation of L-Arginine at a dose of 500mg/100g body weight intraperitoneally, and tacrolimus treatment at a dose of 1ìg/kg subcutaneously for four days. RESULTS: Serum amylase was higher (p = 0.0000) in groups PT, P and T than in the control group. The PT group mean was higher (p = 0.0009) than in the T group, but did not differ (p = 0.6802) from the average of the P group. There was no difference between groups P and T (p = 0.2568). Neither in mean blood glucose between the groups (p = 0.4920); serum levels of tacrolimus were similar in PT and T groups (p = 0.7112). There were no histological changes in groups T and C and no hemorrhage in the pancreas of rats in groups P and PT. In group P, there was no edema in 30 percent, mild edema in 20 percent and in 50 percent, moderate; as for inflammatory infiltration, it was moderate in 80 percent and absent in 20 percent, and atrophy of the parenchyma was moderate in 60 percent and severe in 40 percent. In the PT group, there was edema, inflammatory infiltration or atrophy in the pancreas in all rats. CONCLUSION: Treatment with Tacrolimus induced an increase in serum amylase in normal mice, but did not affect blood glucose or the histological pattern of the pancreatic parenchyma. In the presence of pancreatitis induced by L-Arginine tacrolimus induced edema, inflammatory infiltration and more severe atrophy in the pancreatic parenchyma.

Inmunosupresíón en niños con trasplante hepático / Immunosuppression in children with liver transplantation

La inmunosupresión en niños con trasplante hepático, ha evolucionado con dos momentos clave: la disponibilidad de los inhibidores de calcineurina ciclosporina y tacrolimus. La inmunosupresión primaria se diseña sobre la base de un inhibidor de calcineurina como fármaco principal. Los esteroides se incluyen en la pauta de inmunosupresión primaria en la mayoría de los centros. Las pautas habituales a largo plazo consisten en ciclosporina o tacrolimus, en monoterapia a niveles inferiores a los deseados en el periodo precoz postrasplante, o en combinación con dosis bajas de esteroide. Los inhibidor e s de c a l c ineur ina induc en vasoconstricción arterial aguda y crónica que causa nefrotoxicidad, con disminución del filtrado glomerular y tubulopatía. Los niveles ensangre de ciclosporina o de tacrolimus se determinan para evaluar el estado de inmunosupresión. La edad de adolescente y adulto joven es una etapa de riesgo para el injerto por ser frecuente la omisión accidental de dosis de medicación inmunosupresora, una irregularidad que es difícil de evaluar en su extensión a pesar de una buena relación médicopaciente y frecuentes chequeos. El rechazo tiene una incidencia entre el 30 y 50% de los pacientes, entre los días 5 y 30 postrasplante.

Immunosuppression in children with liver transplantation has evolved with two key moments: the availability of calcineurin inhibitors, cyclosporine and tacrolimus. The primary immunosuppression is designed on the basis of a calcineurin inhibitor as primary drug. Steroids are included in the pr imary immunosuppression regimen in most schools. The long-term normal patterns consist of cyclosporine or tacrolimus as monotherapy to lower than desired levels in the early period aftertransplantation, or in combination with low dose steroid. Calcineurin inhibitors induce arterial vasoconstriction causing acute and chronic nephrotoxicity, with reduced glomerular filtration and tubular. Blood levels of cyclosporine or tacrolimus are determined to assess the state of immunosuppression. The age of adolescence and young adulthood is a time of risk to the graft by the accidental omission to be frequent doses ofimmunosuppressive medication, an irregularitywhich is difficult to assess its extent in spite of a good doctor-patient relationship and frequentcheckups. The rejection has an incidence between 30 and 50% of patients, between 5 and 30 aftertransplantation.

Imunossupressão com tacrolimus favorece a regeneração hepática induzida por hepatectomia ampla em ratos / Tacrolimus-based immunossupression favours liver regeneration induced by extent hepatectomy in rats

OBJETIVO: Avaliar em dois momentos distintos da regeneração hepática a influência do Tacrolimus sobre o fenômeno da regeneração hepática desencadeada pela ressecção de 70 por cento do parênquima hepático em ratos plenamente desenvolvidos. MÉTODOS: Utilizaram-se 40 ratos Wistar com peso médio de 510,08 g ± 11.66 g distribuidos aleatoriamente em dois grupos de 20, cada grupo subdividido em dois subgrupos conforme o dia da morte após a hepatectomia. De acordo com o grupo os animais receberam por gavagem solução aquosa de Tacrolimus 0,1 mg/kg/dia ou solução salina no mesmo volume. Após três dias de pré-terapia todos foram submetidos à hepatectomia de 70 por cento pela ressecção dos lobos hepáticos mediano e lateral esquerdo que foram pesados para posterior cálculo da regeneração hepática pela fórmula de Kwon. Vinte e quatro horas ou sete dias após a hepatectomia, 10 animais de cada grupo foram mortos, os fígados remanescentes (regenerados) foram pesados e amostrados para realização de índice mitótico por hematoxilina-eosina e estudo imunoistoquímico com os marcadores PCNA e Ki-67. RESULTADOS: Os animais que receberam tacrolimus mostraram índice maior de regeneração hepática, atingindo significância estatística quando comparado ao subgrupo de animais mantidos com placebo quando analisados pelos parâmetros: fórmula de Kwon, índice mitótico e marcador PCNA. A tendência para o marcador Ki-67 foi idêntica aos outros parâmetros mas não alcançou significância estatística. CONCLUSÃO: A imunossupressão com tacrolimus possui efeito estimulatório no processo de regeneração hepática desencadeado pela hepatectomia 70 por cento em ratos Wistar adultos, plenamente desenvolvidos.

OBJECTIVE: To analyze, during two different moments of liver regeneration, the effect of the immunosuppressant Tacrolimus on the 70 percent hepatectomy model-induced liver regeneration in adult rats. METHODS: Forty Wistar adult rats, weighing 510.08 + 11.66 g were randomly divided into two groups, each group divided into two subgroups according to the death day after 70 percent hepatectomy . According to the group of study, rats received 0.1mg/Kg/day of Tacrolimus or the same volume of saline solution, by gavage. After three days of pre-therapy, all animals were submitted to 70 percent hepatectomy by resection of median and left lateral hepatic lobes which were weighed for posterior calculation of liver regeneration by Kwon´s formula. Twenty four hours or seven days after hepatectomy ten rats of each group were killed; the remaining liver (regenerated) was entirely resected, weighed and sampled for mitotic index on hematoxylin-eosin staining and immunohistochemical assays with PCNA and Ki-67 markers. Data were statistically analyzed by Mann-Whitney or Student "t" tests, with significance level of 5 percent (p<0.05). RESULTS: Rats receiving tacrolimus showed statistically significant higher levels of liver regeneration when compared to placebo according to Kwon's formula, mitotic index and PCNA marker. Identical trend was found with Ki-67 marker, but without statistical significance. CONCLUSION: Tacrolimus-based immunossuppression has stimulatory effect on liver regeneration process induced by 70 percent hepatectomy in adult Wistar rats.

Is mycophenolate more than just an immunosuppressant?--An overview.

The development of immunosuppressant compounds, such as cyclosporine and tacrolimus was crucial to the success of transplant surgery and for treatment of autoimmune diseases. However, immunosuppressant therapy may increase the concentrations of reactive oxygen species (ROS), inducing oxidative damage such as an increased vascular damage. The major source of ROS in the vascular endothelial cells is NADPH oxidase. The subunit structure and function of this enzyme complex in vascular cells differs from that in phagocytic leucocytes. The enzyme subunits Nox1, Nox2 and Nox4 are only found in vascular cells. The GTP-dependent protein subunit Rac 1 needs to be activated for this enzyme to function. Inhibiting this protein subunit should reduce NADPH oxidase-induced oxidative stress. In the cardiovascular system, oxidative stress is observed as hypertension, hypertrophy, fibrosis, conduction abnormalities and endothelial dysfunction, as well as cardiac allograft vasculopathy in transplant patients. In contrast to cyclosporine and tacrolimus, the immunosuppressant mycophenolate inhibits the Rac 1 subunit thus inhibiting NADPH oxidase in the vasculature. This may reduce oxidative stress, prevent the development of cardiac allograft vasculopathy, decrease the deterioration of vascular function and improve cardiovascular function chronically in transplant patients. This overview discusses whether this antioxidant immunosuppressive property could translate into a more general protective role for mycophenolate in the prevention of cardiovascular disease.

Effect of FK506 on expression of hepatocyte growth factor in murine spinal cord following peripheral nerve injury / 华中科技大学学报（医学）（英德文版）

This study is to investigate the effect of FK506 on expression of hepatocyte growth factor (HGF) in rats' spinal cord following peripheral nerve injury and to elucidate the mechanisms for neuroprotective property of FK506. Fifty male rats were randomly divided into normal group, injury group and treatment group. Models of peripheral nerve injury were established by bilateral transection of sciatic nerve 0.5 cm distal to piriform muscle. Then the treatment group received subcutaneous injection of FK506 (1 mg/kg) at the back of neck, while the injury group was given 0.9% saline. The L(4-6) spinal cords were harvested at various time points after the surgery. Western blotting and immunofluorescent staining were used to detect the level and position of HGF in spinal cord. Immunofluorescent staining showed that HGF-positive neurons were located in anterior horn, intermediate zone and posterior horn of gray matter in normal spinal cord. Western blotting revealed that there was no significant difference in the expressions of HGF between the injury group and the normal group, while the expression of HGF was significantly higher in the treatment group than in the injury group 7 and 14 days after surgery. It is suggested that peripheral nerve injury does not result in up-regulation of the expression of HGF in spinal cord, while FK506 may induce high expression of endogenous HGF after injury thereby protecting neurons and promoting axonal outgrowth.

Exposição de fibroblastos provenientes de pterígios recidivados e da cápsula de Tenon normal ao tacrolimus (FK-506) / Fibroblasts from recurrent pterygium and normal Tenon's capsule exposed to tacrolimus (FK-506)

OBJETIVO: Avaliar a taxa de proliferação de fibroblastos provenientes de pterígios recidivados e da cápsula de Tenon normal, quando expostos in vitro ao tacrolimus (FK 506). MÉTODOS: Foi realizado estudo prospectivo, controlado, avaliando-se 8 amostras de explantes de cápsula de Tenon de pterígios recidivados e 6 de cápsula de Tenon normal, obtidas na Faculdade de Medicina de Botucatu - UNESP. A cápsula de Tenon normal foi colhida da região temporal inferior, do mesmo portador de pterígio. As amostras foram cultivadas em meio específico e posteriormente expostas ao tacrolimus 1M (FK 506), em única exposição, com avaliação da taxa de proliferação celular 1, 5, 12 e 19 dias após a exposição. RESULTADOS: Avaliando-se a proliferação dos fibroblastos provenientes de cápsula de Tenon de pterígios recidivados e da cápsula de Tenon normal, os fibroblastos expostos ao tacrolimus tiveram taxa de proliferação significativamente menor (p<0,05) do que quando não houve exposição a droga, quando a avaliação foi feita 1 dia após a exposição. Quando a avaliação foi feita 19 dias após a exposição, a taxa de proliferação foi maior nos grupos expostos a droga. CONCLUSÃO: Os fibroblastos provenientes da cápsula de Tenon de pterígios recidivados apresentaram taxa de proliferação significativamente menor um dia após a exposição ao tacrolimus. Novos estudos devem ser realizados para definir dose e tempo de exposição dos fibroblastos a droga, com o intuito de definir se o tacrolimus pode ser útil como tratamento coadjuvante do pterígio.

PURPOSE: To evaluate fibroblast proliferation activity of normal Tenon's capsule and of recurrent pterygia exposed in vitro to tacrolimus (FK506). METHODS: A randomized prospective study was performed with 8 samples of recurrent pterygia and 6 samples of normal Tenon's capsule from the same patient with pterygium at the Faculdade de Medicina de Botucatu - UNESP. The samples were cultivated and exposed once to 1M tacrolimus (FK 506) and the proliferation rate was evaluated 1, 5, 12 and 19 days after the exposure. The data were statistically analyzed. RESULTS: The fibroblasts from pterygia exposed in vitro to tacrolimus had a significantly lower proliferation rate than controls after one day of exposure (p<0.05). Nineteen days after exposure to tacrolimus, exposed cells proliferated more than the non-exposed. CONCLUSION: Tacrolimus is effective to inhibit proliferation of Tenon's capsule fibroblasts from pterygia one day after exposure. Further studies are needed to define the role of tacrolimus in pterygium treatment.

Calcineurin inhibitors in the treatment of allergic dermatitis

OBJETIVO: Revisar o papel dos inibidores da calcineurina no tratamento das dermatoses alérgicas, com ênfase nos mecanismos de ação, eficácia e efeitos adversos tópicos e sistêmicos. FONTES DOS DADOS: Artigos de língua inglesa publicados na MEDLINE, considerando as palavras chave: pimecrolimus, tacrolimo, calcineurin inhibitors. Foram selecionados os artigos originais que apresentaram estudos controlados e estudos abertos para avaliação da eficácia, tolerabilidade e eventos adversos. Também foram avaliados artigos de revisão e relatos e série de casos, sendo estes últimos considerados apenas para avaliação de efeitos adversos. Foram consultados os sites oficiais da Food and Drug Administration e dos fabricantes de inibidores da calcineurina. SíNTESE DOS DADOS: Os dados mostraram que inibidores de calcineurina são eficientes no tratamento da dermatite atópica leve a grave, levando a melhora dos sintomas, diminuição do número de crises e necessidade de corticoterapia tópica. Apresentam boa tolerabilidade e poucos efeitos adversos tópicos. Até o momento, não há evidências que sustentem a maior prevalência de neoplasias nos pacientes que utilizam esses medicamentos; entretanto, um adequado sistema de farmacovigilância está montado para avaliar esse aspecto. CONCLUSÕES: Os inibidores de calcineurina são uma nova classe de medicamentos para o tratamento das dermatoses alérgicas. São eficazes, tolerados e com poucos efeitos adversos. Devem ser sempre utilizados de acordo com as orientações preconizadas, e os pacientes devem ser sempre acompanhados pelo médico durante e após sua administração.

OBJECTIVE: To review the role of calcineurin inhibitors in the treatment of allergic dermatitis, focusing on mechanisms of action, efficacy and topical and systemic adverse effects. SOURCES: Articles written in English and published in MEDLINE using the following keywords: pimecrolimus, tacrolimus, calcineurin inhibitors. Original articles that presented controlled and open studies for assessing efficacy, tolerability and adverse effects were selected. Review articles and case series were also evaluated; the latter was only considered for assessing adverse effects. The official websites of the Food and Drug Administration and of manufacturers of calcineurin inhibitors were also used. SUMMARY OF THE FINDINGS: The data showed that calcineurin inhibitors are efficient in the treatment of mild to severe atopic dermatitis, leading to improvement in symptoms, reduction in number of attacks and need of topical corticotherapy. Calcineurin inhibitors have good tolerability and few topical adverse effects. To date, there has been no evidence to support higher prevalence of neoplasia in patients using these drugs; however, an adequate pharmacovigilance system has been set up to assess this aspect. CONCLUSIONS: Calcineurin inhibitors, which are a new drug class in the treatment of allergic dermatitis, are efficient, well tolerated and have few adverse effects. Calcineurin inhibitors should always be used according to recommended guidelines, and patients should always be followed by the physician during and after their administration.

Inmunosupresión para receptores de trasplante renal: estrategias actuales / Immunosuppression for kidney transplant recipients: current strategies

Immunosuppressive therapy aims to protect transplanted organs from host responses. The success achieved during the last two decades in patient and graft survival is mainly related to the development and clinical use of efficacious immunosuppressive drugs. Nevertheless, the challenge of achieving a balance of adequate graft protection while minimizing the adverse consequences of excessive immunosuppression in the long-term continues. Current maintenance immunosuppression for renal transplant recipients generally consists of a calcineurin inhibitor plus an adjunctive antiproliferative agent, and steroids. The addition of induction therapy with a variety of monoclonal or polyclonal antibodies provides a more potent immunosuppression and its use is more relevant in patients with a high immunological risk. More recently, mammalian target of rapamycin inhibitors have been incorporated in different schemes proven its efficacy in a number of protocols. The incidence of acute rejection is now in its lower historical percentage and excellent results are reported from many transplant centers all over the world due mainly to a judicious combination of these drugs evaluated through many clinical studies. However, long-term use of immunosuppressive drugs convey inherent risks which translate in an increase of cancers and infections, among others. Ongoing investigations and clinical protocols involving new immunosuppressive drugs and biological agents are yielding important information on how to obtain tolerance or the nearest to this goal. Furthermore, there should be a continuous improvement in patient and graft survival, as the use of different immunosuppressive agents for induction and maintenance are individualized (adapted to each patient).

La terapia inmunosupresora empleada en receptores de trasplante tiene el objetivo de proteger el injerto de la respuesta inmunoloógica generada por parte del huésped. El éxito logrado en el transcurso de las últimas dos décadas en la supervivencia de receptores e injertos, ha dependido en gran medida del desarrollo y uso clínico de fármacos inmunosupresores de probada eficacia. Empero el enorme beneficio que han representado, el reto continúa para mantener un balance adecuado entre la protección inmunológica del injerto y la minimización de las consecuencias adversas derivadas de su indispensable utilización a largo plazo. La terapia inmunosupresora actual de mantenimiento en receptores de trasplante renal consiste habitualmente en la administración de un inhibidor de calcineurina, un agente antiproliferativo, como adyuvante, y esteroides. La adición de terapia de inducción, con modalidades biológicas de anticuerpos mono o policlonales, proveen un mayor grado de inmunosupresión y su empleo adquiere gran relevancia en pacientes con mayor riesgo inmunológico. En una etapa más reciente, los inhibidores del blanco de rapamicina han sido introducidos en varios esquemas después de probar su eficacia en múltiples protocolos. La incidencia de rechazo agudo ha alcanzado sus más bajos índices históricos y los resultados alcanzados en muchos centros de trasplante del mundo son excelentes, derivados en gran medida de la combinación juiciosa de estos fármacos, evaluados en una gran variedad de estudios. El empleo crónico de estos fármacos conlleva riesgos inherentes que se traducen en riesgos incrementados para el desarrollo de infecciones y neoplasias, entre otros. Así, mientras esperamos nuevos avances derivados de una gran profusión de estudios de investigación y protocolos clínicos con nuevas drogas inmunosupresoras y compuestos biológicos, encaminados a obtener tolerancia o lo más cercano a este propósito, deberemos ser capaces de continuar mejorando la vida funcional de la mayoría de los injertos y, desde luego, de sus receptores, "individualizando" (de acuerdo con los riesgos de cada paciente) el empleo de los agentes inmunosupresores disponibles para inducción y mantenimiento.

Antinociceptive action of FK506 in mice.

Immunophilins are abundantly present in the brain as compared to the immune system. Immunophilin-binding agents like FK506 are known to inactivate neuronal nitric oxide synthase (nNOS) by inhibiting calcineurin and decrease the production of nitric oxide. Nitric oxide is involved in the mediation of nociception at the spinal level. In the present study, the effect of FK506 on the tail flick response in mice and the possible involvement of NO-L-arginine pathway in this paradigm was evaluated. FK506 (0.5, 1 and 3 mg/kg, ip) produced a significant antinociception in the tail flick test. Nitric oxide synthase (NOS) inhibitor L-NAME significantly and dose dependently (10-40 mg/kg, ip) potentiated the FK506 (0.5 mg/kg)-induced antinociception. On the other hand, NOS substrate L-arginine (100, 200 and 400 mg/kg) inhibited the FK506-induced antinociception in a dose-dependent manner. Concomitant administration of L-NAME (20 and 40 mg/kg) with L-arginine (200 mg/kg) blocked the inhibition exerted by L-arginine on the FK506-induced antinociception. Thus, it was concluded that NO- L-arginine pathway may be involved in the FK506-induced antinociception in tail flick test.

Induction of fibronectin gene expression by inhibitors of protein phosphatase type 2B in normal and transformed fibroblasts

Two intracellular signal pathways mediated by cAMP and protein kinase C (PKC) were involved in the regulation of FN gene expression (Lee et al., Exp. Mol. Med. 30: 240, 1998). In this study, a possible involvement of protein phosphatase-dependent pathways in the regulation of FN gene expression was investigated by using protein phosphatase type 2B (PP2B) inhibitors, cyclosporin A and ascomycin. Both cyclosporin A and ascomycin increased the levels of FN mRNA in WI-38 human lung fibroblasts and the SV40-transformed WI-38 cells but not in MC3T3-E1 osteoblasts. The expression of FN appears to increase from six hours up to 48 hours after treatment suggesting that it is not an immediate effect. In addition, this effect required a new protein synthesis. Neither cyclosporin A nor ascomycin affects the phorbol myristate acetate (PMA)-induced stimulation of FN gene expression and the same result occurred in vice versa suggesting the mechanism of PMA and cyclosporin A/ascomycin in the regulation of FN gene expression may share a common downstream pathway. Taken together, this study suggests that PP2B is involved in the regulation of FN gene expression in normal and transformed fibroblasts but not in osteoblasts.

Uso de FK 506 en trasplante de hígado / Use of FK 506 in liver transplant

El Fk 509 es un macrólido natural con una potente actividad inmunosupresora. Experimentos in vitro han demostrado la supresión de la inmunidad celular mediada por linfocitos T. Experiencias clínicas han demostrado su utilidad como tratamiento en terapia de rescate en pacientes que han recibido un trasplante de hígado, que presentaban rechazo y cuando éste es resistente a las terapias actuales en uso. El objetivo de esta presentación es mostrar lo que sucedió con 15 pacientes que recibieron FK 506 como terapia inmunosupresora principal. Forma parte de un estudio multicéntrico europeo, prospectivo y randomizado, cuyo objetivo es comparar la utilidad de FK 506 v/s CyA en trasplante de hígado. La serie estudiada estuvo constituida por 28 pacientes; 15 recibieron FK 506 y 13 recibieron CyA. Las observaciones que se obtienen en esta evaluación inicial son: a) el FK 506 tiene efectos colaterales adversos en tipo y frecuencia similar a la obtenida en pacientes que son tratados con CyA; b) la incidencia de insuficiencia renal postoperatoria parece estar relacionada con la dosificación y niveles de FK 506; c) para demostrar la superioridad de una alternativa de tratamiento (FK 506) sobre el otro (CyA), se requiere de un gran número de pacientes y seguidos por un período prolongado; d) es probable que el FK 506 sea una buena alternativa para el tratamiento asociado con CyA como terapia de rescate