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1.
BJS Open ; 4(5): 804-810, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32700415

RESUMO

BACKGROUND: The role of antithrombotic chemoprophylaxis in prevention of venous thromboembolism (VTE) in laparoscopic surgery for gastric and colorectal malignancies is unknown. This study compared the addition of enoxaparin following intermittent pneumatic compression (IPC) with IPC alone in patients undergoing laparoscopic surgery for gastrointestinal malignancy. METHODS: In this multicentre RCT, eligible patients were older than 40 years and had a WHO performance status of 0 or 1. Exclusion criteria were prescription of antiplatelet or anticoagulant drugs and history of VTE. Patients were allocated to IPC or to ICP with enoxaparin in a 1 : 1 ratio. Stratification factors included sex, location of cancer, age 61 years and over, and institution. Enoxaparin was administered on days 1-7 after surgery. Primary outcome was VTE, evaluated by multidetector CT on day 7. RESULTS: Of 448 patients randomized, 208 in the IPC group and 182 in the IPC with enoxaparin group were evaluated. VTE occurred in ten patients (4·8 per cent) in the IPC group and six (3·3 per cent) in the IPC with enoxaparin group (P = 0·453). Proximal deep vein thrombosis and/or pulmonary embolism occurred in seven patients (3·4 per cent) in the IPC group and one patient (0·5 per cent) in the IPC with enoxaparin group (P = 0·050). All VTE events were asymptomatic and non-fatal. Bleeding occurred in 11 of 202 patients in the IPC with enoxaparin group, and one patient needed a transfusion. All bleeding events were managed by discontinuation of the drug. CONCLUSION: IPC with enoxaparin after laparoscopic surgery for gastric and colorectal malignancies did not reduce the rate of VTE. Registration number: UMIN000011667 ( https://www.umin.ac.jp/).


ANTECEDENTES: El papel de la quimioprofilaxis para la prevención del tromboembolismo venoso (venous thromboembolism, VTE) en la cirugía laparoscópica de los tumores malignos gástricos y colorrectales se desconoce. El objetivo de este estudio fue comparar la quimioprofilaxis antitrombótica (enoxaparina) y la compresión neumática intermitente (intermittent pneumatic compression, IPC) en pacientes sometidos a cirugía laparoscópica de tumores malignos abdominales. MÉTODOS: Se efectuó un ensayo aleatorizado, controlado y multicéntrico de pacientes sometidos a cirugía laparoscópica de tumores gástricos y colorrectales en Japón. Los criterios de inclusión eran pacientes mayores de 40 años de edad y con un estado funcional de WHO de 0-1. Los criterios de exclusión fueron la prescripción al paciente de fármacos antiagregantes o anticoagulantes y la historia de VTE. Los pacientes fueron asignados a IPC y ICP con la adición de enoxaparina en una relación 1:1. Los factores de estratificación incluyeron el sexo, la localización del cáncer, la edad mayor o menor de 61 años, y la institución. La enoxaparina fue administrada en los días postoperatorios (postoperative day, POD) 1-7. El resultado primario fue la VTE evaluada mediante tomografía computarizada multidetector en el POD7. Los cálculos de la potencia determinaron que se requerían 184 pacientes en cada grupo. RESULTADOS: De los 448 pacientes aleatorizados, se evaluaron finalmente 208 pacientes en el grupo IPC y 182 pacientes en el grupo IPC más enoxaparina. La VTE ocurrió en 10 de 208 pacientes en el grupo IPC (4,8%) y 6 de 182 pacientes en el grupo IPC más enoxaparina (3,3%) (P = 0,45). La trombosis venosa profunda proximal (proximal deep vein thrombosis, DVT) y/o el embolismo pulmonar (pulmonary embolism, PE) ocurrieron en 7 de 208 pacientes en el grupo IPC (3,4%) y 1 de 182 pacientes en el grupo IPC más enoxaparina (0,55%) (riesgo relativo 0,163, i.c. del 95% 0,020-1,314, P = 0,0503). Todos los eventos de VTE fueron asintomáticos y no mortales. Se produjo una hemorragia en 11 de 202 pacientes en el grupo IPC con enoxaparina (5,4%, i.c. del 95% 3,1%-9,5%, P < 0,001), y un paciente precisó transfusión. Todos los eventos hemorrágicos pudieron ser tratados con la interrupción del fármaco. CONCLUSIÓN: La IPC con la adición de enoxaparina tras cirugía laparoscópica de los tumores malignos gástricos y colorrectales no disminuye la VTE.


Assuntos
Enoxaparina/uso terapêutico , Dispositivos de Compressão Pneumática Intermitente , Laparoscopia/efeitos adversos , Complicações Pós-Operatórias/prevenção & controle , Tromboembolia Venosa/prevenção & controle , Idoso , Anticoagulantes/uso terapêutico , Neoplasias Colorretais/cirurgia , Feminino , Hemorragia/epidemiologia , Hemorragia/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Embolia Pulmonar/prevenção & controle , Neoplasias Gástricas/cirurgia , Tromboembolia Venosa/epidemiologia
2.
Am J Transplant ; 15(10): 2565-75, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26012352

RESUMO

Unpreventable allograft rejection is one of the main problems in pancreatic islet transplantation (PIT). Therefore, it is imperative to develop a more effective immunosuppressive strategy. The blockade of transcription factors has been a central part of T cell-depleting immunosuppressive therapies, as typified by the use of calcineurin inhibitors. The inhibition of activator protein-1 (AP-1) offers a novel strategy for immunosuppression in PIT, although to date, no reports on the effects of AP-1 inhibition are available. In this study, we investigated the immunosuppressive effects of T-5224, a c-Fos/AP-1-selective inhibitor, on murine T cells activated by αCD3+αCD28 mAbs. T-5224 inhibited proliferation, CD25 up-regulation, and the production of IL-2 and interferon-γ. In addition, T-5224 blocked the nuclear translocation of c-Fos/AP-1 in activated murine T cells. In BALB/c (H-2(d) )-to-C57BL/6J (H-2(b) ) mouse PIT, the 2-week administration of T-5224 prolonged survival of 600 islet allografts in a dose-dependent manner. When combined with a 2-week low-dose tacrolimus, the T-5224 treatment markedly prolonged allograft survival to over 300 days, while the efficacy was indeterminate when transplanted islet allograft mass was reduced to 300. We conclude that the c-Fos/AP-1 inhibition by T-5224 is a potentially attractive strategy for allogeneic PIT.


Assuntos
Benzofenonas/uso terapêutico , Rejeição de Enxerto/prevenção & controle , Imunossupressores/uso terapêutico , Transplante das Ilhotas Pancreáticas/imunologia , Isoxazóis/uso terapêutico , Animais , Benzofenonas/farmacologia , Rejeição de Enxerto/imunologia , Imunossupressores/farmacologia , Isoxazóis/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-fos/antagonistas & inibidores , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fator de Transcrição AP-1/antagonistas & inibidores , Transplante Homólogo
3.
Am J Transplant ; 13(8): 1976-88, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23841873

RESUMO

A strategy for inhibiting CD40 has been considered as an alternative approach for immunosuppression because of undesirable effects of anti-CD154 monoclonal antibodies (mAbs). Previously, we demonstrated that ASKP1240, which is a fully human anti-CD40 mAb, significantly prolonged kidney and liver allograft survival in cynomolgus monkeys without causing thromboembolic complications. Herein, we evaluated the effect of ASKP1240 on pancreatic islet transplantation (PITx) in cynomolgus monkeys. Diabetes was induced by total pancreatectomy, and islet allografts were transplanted into the liver. Following PITx (8201-12 438 IEQ/kg), blood glucose levels normalized promptly in all animals. Control islet allografts were rejected within 9 days (n = 3), whereas ASKP1240 (10 mg/kg) given on postoperative days 0, 4, 7, 11 and 14 (induction treatment, n = 5) significantly prolonged graft survival time (GST) to >15, >23, 210, 250 and >608 days, respectively. When ASKP1240 (5 mg/kg) was administered weekly thereafter up to post-PITx 6 months (maintenance treatment, n = 4), GST was markedly prolonged to >96, >115, 523 and >607 days. During the ASKP1240 treatment period, both anti-donor cellular responses and development of anti-donor antibodies were abolished, and no serious adverse events were noted. ASKP1240 appears to be a promising candidate for immunosuppression in clinical PITx.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Ligante de CD40/imunologia , Diabetes Mellitus Tipo 1/terapia , Sobrevivência de Enxerto , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/imunologia , Animais , Anticorpos Monoclonais/farmacocinética , Ligante de CD40/antagonistas & inibidores , Ligante de CD40/metabolismo , Diabetes Mellitus Tipo 1/etiologia , Diabetes Mellitus Tipo 1/metabolismo , Humanos , Tolerância Imunológica , Ilhotas Pancreáticas/metabolismo , Macaca fascicularis , Masculino , Pancreatectomia/efeitos adversos , Distribuição Tecidual , Transplante Homólogo
4.
Br J Cancer ; 107(1): 137-42, 2012 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-22644300

RESUMO

BACKGROUND: Mesothelin is expressed in various types of malignant tumour, and we recently reported that expression of mesothelin was related to an unfavourable patient outcome in pancreatic ductal adenocarcinoma. In this study, we examined the clinicopathological significance of the mesothelin expression in gastric cancer, especially in terms of its association with the staining pattern. METHODS: Tissue specimens from 110 gastric cancer patients were immunohistochemically examined. The staining proportion and intensity of mesothelin expression in tumour cells were analysed, and the localisation of mesothelin was classified into luminal membrane and/or cytoplasmic expression. RESULTS: Mesothelin was positive in 49 cases, and the incidence of mesothelin expression was correlated with lymph-node metastasis. Furthermore, luminal membrane staining of mesothelin was identified in 16 cases, and the incidence of luminal membrane expression was also correlated with pT factor, pStage, lymphatic permeation, blood vessel permeation, recurrence, and poor patient outcome. Multivariate analysis showed that luminal membrane expression of mesothelin was an independent predictor of overall patient survival. CONCLUSION: We described that the luminal membrane expression of mesothelin was a reliable prognostic factor in gastric cancer, suggesting the functional significance of membrane-localised mesothelin in the aggressive behaviour of gastric cancer cells.


Assuntos
Proteínas Ligadas por GPI/metabolismo , Neoplasias Gástricas/metabolismo , Idoso , Biomarcadores Tumorais/metabolismo , Células Epiteliais/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Linfonodos/metabolismo , Metástase Linfática , Masculino , Mesotelina , Pessoa de Meia-Idade , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Análise de Sobrevida
5.
J Biol Chem ; 275(21): 15652-6, 2000 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-10748003

RESUMO

Despite the lower site 1 affinity of the 20-kDa human growth hormone (20K-hGH) for the hGH receptor (hGHR), 20K-hGH has the same hGHR-mediated activity as 22-kDa human GH (22K-hGH) at low hGH concentration and even higher activity at high hGH concentration. This study was performed to elucidate the reason why 20K-hGH can activate hGHR to the same level as 22K-hGH. To answer the question, we hypothesized that the binding between the stem regions of hGHR could compensate for the weaker site 1 binding of 20K-hGH than that of 22K-hGH in the sequential binding with hGHR. To demonstrate it, we prepared 15 types of alanine-substituted hGHR gene at the stem region and stably transfected them into Ba/F3 cells. Using these cells, we measured and compared the cell proliferation activities between 20K- and 22K-hGH. As a result, the activity of 20K-hGH was markedly reduced than that of 22K-hGH in three types of mutant hGHR (T147A, H150A, and Y200A). Regarding these mutants, the dissociation constant of hGH at the first and second step (KD1 and KD2) in the sequential binding with two hGHRs was predicted based on the mathematical cell proliferation model and computational simulation. Consequently, it was revealed that the reduction of the activity in 20K-hGH was attributed to the change of not KD1 but KD2. In conclusion, these findings support our hypothesis, which can account for the same potencies for activating hGHR between 20K- and 22K-hGH, although the site 1 affinity of 20K-hGH is lower than that of 22K-hGH.


Assuntos
Hormônio do Crescimento Humano/farmacologia , Proteínas de Membrana/metabolismo , Animais , Sítios de Ligação , Divisão Celular/genética , Linhagem Celular , Dimerização , Humanos , Proteínas de Membrana/genética , Camundongos , Mutação , Ligação Proteica , Proteínas Recombinantes/metabolismo , Transfecção
6.
Surg Today ; 28(7): 746-52, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9697270

RESUMO

The influence of warm ischemia on the metabolism of prostaglandins was investigated using a pig liver transplantation model employing the temporary portal arterialization technique. Eighteen pigs were divided into three groups according to warm ischemia time: 0 min (group I, n = 6), 30 min (group II, n = 6), and 60 min (group III, n = 6). During portal arterialization, the hepatic venous prostaglandin E2 (PGE2) level in group III (3356.0 +/- 1011.8 pg/ml) was significantly higher than that in group I (831.7 +/- 182.1 pg/ml; P = 0.0285). The hepatic venous PGE2 levels were significantly higher than the arterial counterparts in all groups both at the beginning and during portal arterialization. At 60 min after portal revascularization, the arterial PGE2 level in group III (886.7 +/- 268.0 pg/ml) was significantly higher than that in group I (99.0 +/- 18.6 pg/ml; P = 0.0116) and II (204.2 +/- 65.4 pg/ml; P = 0.0282). Neither thromboxane B2 (TXB2) nor 6-keto PGF1 alpha showed any significant differences. In conclusion, the intraoperative changes of PGE2 thus reflected the degree of warm ischemic damage, and PGE2 could also be released from the graft. On the other hand, the increased levels of TXB2 and 6-keto PGF1 alpha were thought to have an extrahepatic origin.


Assuntos
Isquemia , Transplante de Fígado/métodos , Fígado/irrigação sanguínea , Prostaglandinas/metabolismo , Animais , Biomarcadores/análise , Artéria Hepática , Veias Hepáticas , Transplante de Fígado/fisiologia , Suínos , Temperatura
7.
Cell Transplant ; 7(4): 357-63, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9710304

RESUMO

Intracranial hypertension leading to brain stem herniation is a major cause of death in fulminant hepatic failure (FHF). Mannitol, barbiturates, and hyperventilation have been used to treat brain swelling, but most patients are either refractory to medical management or cannot be treated because of concurrent medical problems or side effects. In this study, we examined whether allogeneic hepatocellular transplantation may prevent development of intracranial hypertension in pigs with experimentally induced liver failure. Of the two preparations tested--total hepatectomy (n = 47), and liver devascularization (n = 16)--only pigs with liver ischemia developed brain edema provided, however, that animals were maintained normothermic throughout the postoperative period. This model was then used in transplantation studies, in which six pigs received intrasplenic injection of allogeneic hepatocytes (2.5 x 10(9) cells/pig) and 3 days later acute liver failure was induced. In both models (anhepatic state, liver devascularization), pigs allowed to become hypothermic had significantly longer survival compared to those maintained normothermic. Normothermic pigs with liver ischemia had, at all time points studied, ICP greater than 20 mmHg. Pigs that received hepatocellular transplants had ICP below 15 mmHg until death; at the same time, cerebral perfusion pressure (CPP) in transplanted pigs was consistently higher than in controls (45 +/- 11 mmHg vs. 16 +/- 18 mmHg; p < 0.05). Spleens of transplanted pigs contained clusters of viable hepatocytes (hematoxylin-eosin, CAM 5.2). It was concluded that removal of the liver does not result in intracranial hypertension; hypothermia prolongs survival time in both anhepatic pigs and pigs with liver devascularization, and intrasplenic transplantation of allogeneic hepatocytes prevents development of intracranial hypertension in pigs with acute ischemic liver failure.


Assuntos
Transplante de Células , Hipertensão Intracraniana/prevenção & controle , Falência Hepática/terapia , Fígado/citologia , Animais , Modelos Animais de Doenças , Feminino , Galactosamina/toxicidade , Hepatectomia , Encefalopatia Hepática/etiologia , Encefalopatia Hepática/terapia , Isquemia/complicações , Fígado/irrigação sanguínea , Falência Hepática/etiologia , Suínos
8.
Artif Organs ; 20(10): 1125-9, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8896733

RESUMO

Twelve porcine liver transplantations were performed to investigate whether serum hyaluronic acid (HA) serves as a marker of warm ischemic injury. Group 1 was a control without warm ischemia (n = 7), and pigs in Group 2 were sacrificed by intracardiac KCl injection 60 min before harvesting (n = 5). All pigs survived more than 4 days in Group 1. In Group 2, all died within 2 days due to graft failure. Arterial and hepatic venous glutamic-oxaloacetic transaminase (GOT) in Group 2 were higher after revascularization. However, there were no differences between the 2 groups in arterial and hepatic venous HA levels. HA clearance by the graft also showed no differences between the groups. Although GOT reflected the degree of warm ischemia, HA and its hepatic clearance were not influenced by warm ischemic damage. In conclusion, HA was not thought to serve as a marker of liver injury when the graft suffered from warm ischemia.


Assuntos
Ácido Hialurônico/sangue , Transplante de Fígado/efeitos adversos , Traumatismo por Reperfusão/fisiopatologia , Animais , Aspartato Aminotransferases/metabolismo , Feminino , Coração/efeitos dos fármacos , Veias Hepáticas/enzimologia , Transplante de Fígado/imunologia , Transplante de Fígado/mortalidade , Masculino , Cloreto de Potássio/administração & dosagem , Cloreto de Potássio/toxicidade , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/mortalidade , Suínos , Doadores de Tecidos
12.
Artif Organs ; 20(2): 169-77, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8712965

RESUMO

With a view toward furthering the development of artificial liver systems, we have been culturing hepatocytes in vitro. The object of this research was to investigate the ideal conditions of oxygen tension for the efficient functioning of hepatocytes. Viable hepatocytes isolated from rat livers were cultured under five different oxygen tensions: 5, 10, 20, 50 and 90% O2. DNA contents, gluconeogenesis, urea synthesis, adenosine triphosphate (ATP) levels, and lipid peroxidation of hepatocytes were evaluated. Under the 5% oxygen conditions, the function of hepatocytes was very inferior and was accompanied by a low ATP level. However, hepatocytes cultured under 90% oxygen tension functioned less effectively than the control (20% O2) with elevated lipid peroxidation. The data in this study suggest that the optimum oxygen condition for cultured hepatocytes is 10 approximately 50%, and that especially under conditions of 20% oxygen tension, i.e., that of the ordinary atmosphere, hepatocytes can function most effectively.


Assuntos
Transplante de Fígado , Fígado/citologia , Consumo de Oxigênio/fisiologia , Trifosfato de Adenosina/metabolismo , Animais , Órgãos Artificiais/tendências , Sobrevivência Celular/fisiologia , Células Cultivadas , Citoplasma/metabolismo , Citoplasma/patologia , Citoplasma/ultraestrutura , DNA/metabolismo , Gluconeogênese/fisiologia , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos/fisiologia , Fígado/metabolismo , Fígado/ultraestrutura , Masculino , Microscopia de Contraste de Fase , Ratos , Ratos Wistar , Ureia/metabolismo
13.
Hokkaido Igaku Zasshi ; 70(5): 755-64, 1995 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-8543281

RESUMO

The effect of recombinant human Hepatocyte Growth Factor (rhHGF) on gluconeogenesis, urea synthesis, ATP level and total protein amount of rat hepatocytes in primary culture was investigated for 5 days in culture. According to the rhHGF concentration in media (1,5,10 ng/ml), three groups were designed. The group added Epidermal Growth Factor (EGF) was chosen as a control group. Gluconeogenesis was increased significantly on day 1 by addition of HGF, not by a concentration dependency fashion, but urea synthesis was not activated by HGF and declined on day 5. ATP levels were maintained and kept high during the culture in the EGF group. But ATP levels in the HGF groups were lower than those of the control and significantly declined on day 5. The same tendency was observed in the total amount of protein. In the EGF group, total amount of protein was maintained throughout the experimental period, but the HGF groups could not keep the amount of protein of day 1 till day 5. Phase contrast microscopic findings also showed detachment and deformity of cells on day 5 in the HGF groups. These results suggested that HGF activated gluconeogenesis of the rat hepatocytes in primary culture in early days, but it did not activate urea synthesis, and prolonged exposure of HGF caused to decline intracellular ATP levels and led to cell death in culture condition, which was speculated that the strong effect on hepatocytes by HGF exhausted cell energy. HGF was thought to be unfavorable in the respect of maintenance of primary cultured hepatocytes, but further studies are needed to confirm this speculation.


Assuntos
Fator de Crescimento de Hepatócito/farmacologia , Fígado/citologia , Trifosfato de Adenosina/metabolismo , Animais , Células Cultivadas , Gluconeogênese/efeitos dos fármacos , Humanos , Fígado/metabolismo , Masculino , Proteínas/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Ureia/metabolismo
14.
Int J Artif Organs ; 18(1): 27-33, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7607754

RESUMO

To assess the possibility of using hepatocytes from ischemic liver, as a bioreactor of a hybrid artificial liver, we investigated the influence of warm ischemia on the isolation and culture of hepatocytes in rats. Warm ischemia was induced by clamping the liver hilus and the animals were divided into 3 groups according to the duration of ischemia: group A (no ischemia), group B (10 minutes) and group C (20 minutes). Hepatocytes were isolated by the collagenase perfusion method and cultured for 5 days. The yield and viability of the isolated hepatocytes were lower in group C. Rate of attachment was decreased as the duration of ischemia increased. There was no significant difference observed in functions in culture. Sufficient hepatocytes, as a bioreactor, can be isolated and cultured from warm ischemic liver within 10 minutes. Though the number of available hepatocytes were diminished, hepatocytes procured from longer warm ischemic liver could be utilized as a bioreactor.


Assuntos
Órgãos Artificiais , Isquemia/fisiopatologia , Transplante de Fígado , Fígado/irrigação sanguínea , Fígado/citologia , Análise de Variância , Animais , Adesão Celular/fisiologia , Sobrevivência Celular , Células Cultivadas , DNA/metabolismo , Gluconeogênese/fisiologia , Ligadura , Fígado/metabolismo , Masculino , Malondialdeído/análise , Malondialdeído/metabolismo , Microscopia de Contraste de Fase , Ratos , Ratos Sprague-Dawley , Ureia/metabolismo
15.
J Antibiot (Tokyo) ; 46(9): 1447-57, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8226323

RESUMO

Synthesis and antifungal activity of pradimicin analogs modified on the aglycone part is described. Upon modification studies at various sites of the aglycone part using pradimicin A (PRM A), C-11 position was found to be the sole site to be modified without loosing antifungal activity. Further modification studies at C-11 position were carried out with 11-OH derivative of pradimicin T1 (PRM T1) because of its easy availability. Among the compounds prepared, 11-demethoxy derivative of PRM A (12) and 11-O-ethyl (13) and 11-O-fluoroethyl (14) derivatives of PRM T1 showed promising antifungal activity comparable to that of PRM A.


Assuntos
Antibióticos Antineoplásicos/síntese química , Antifúngicos/síntese química , Antibióticos Antineoplásicos/farmacologia , Antifúngicos/farmacologia , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Estrutura Molecular
16.
J Antibiot (Tokyo) ; 46(8): 1246-51, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8407587

RESUMO

In order to explore potent derivatives of pradimicins (PRMs), modification of their C4'-amino group was carried out. 4'-N-Cyano (1,2), 4'-deamino-4'-nitroguanidino (4), 4'-deamino-4'-ureido (7-9) and 4'-deamino-4'-thioureido (10) derivatives were synthesized by trimethylsilylation of PRMs A and C, followed by condensation with appropriate reagents. 4'-Deamino-4'-guanidino (5) and 4'-deamino-4'-amidino (6) derivatives were synthesized by catalytic hydrogenation of 4 and 2, respectively. 4'-N-Nitroso derivative 3 was prepared by treatment of PRM A with nitrous acid. Among these compounds, the 4'-N-cyano derivative of PRM C (2) exhibited in vitro and in vivo antifungal activities comparable to the parent compounds together with good water-solubility.


Assuntos
Antraciclinas , Antibióticos Antineoplásicos/farmacologia , Antifúngicos/farmacologia , Fungos Mitospóricos/efeitos dos fármacos , Animais , Antibióticos Antineoplásicos/química , Antifúngicos/química , Masculino , Camundongos , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Solubilidade , Relação Estrutura-Atividade
17.
J Antibiot (Tokyo) ; 46(5): 833-9, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8514638

RESUMO

Cephalosporins having a catechol through a variety of linkages to the C3 position and a different C7 side chain were prepared. Among them, 3-(catechol-4- ylcarbonyloxy)methylcephalosporin (14) and 3-[(E)-3-(catechol-4-ylcarbonyloxy)-1-propen-1-yl]cephalospo rin (10) showed excellent activity against Gram-negative activity including ceftazidime-resistant Escherichia coli, Pseudomonas aeruginosa, Xanthomonas maltophilia and Pseudomonas cepacia.


Assuntos
Cefalosporinas/síntese química , Cefalosporinas/farmacologia , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade
18.
J Antibiot (Tokyo) ; 46(5): 840-9, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8514639

RESUMO

Two groups of cephalosporins substituted with a variety of heterocyclic catechols in the C3 side chain were synthesized. One is a group of 3-(heterocyclic catechol-substituted methyl)cephalosporins and another is 3-[(E)-3-heterocyclic catechol-substituted 1-propen-1-yl]cephalosporins. Cephalosporins in the latter group showed higher in vivo efficacies than those in the former group having the same heterocyclic catechol, especially against Pseudomonas aeruginosa A9843A, although there was no significant difference between their in vitro activity. Among the latter group, the 5,6-dihydroxybenzimidazole derivative (6e) and the 2,6-dihydro-7-hydroxy-6-oxo- isoquinoline derivative (6b) showed much higher activity than ceftazidime (CAZ) and imipenem (IPM) against P. aeruginosa A9843A both in in vitro and in vivo studies.


Assuntos
Cefalosporinas/síntese química , Cefalosporinas/farmacologia , Animais , Ceftazidima/farmacologia , Cefalosporinas/farmacocinética , Meia-Vida , Imipenem/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Infecções por Pseudomonas/tratamento farmacológico , Estereoisomerismo , Relação Estrutura-Atividade
19.
J Antibiot (Tokyo) ; 46(5): 850-7, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8514640

RESUMO

7-[(Z)-2-(2-Aminothiazol-4-yl)-2-methoxy-(or hydroxy)-iminoacetamido]-3- [propen-1-yl]-cephalosporins having a variety of heterocyclic catechol in 3-position of the propenyl group were synthesized. Among them, 6,7-dihydroxyisoquinoline derivatives, 2a and 2b, showed very high and prolonged blood levels after intramuscular administration to mice and higher in vivo antibacterial activity than expected from their in vitro activity. The former cephalosporin (2a) gave well-balanced in vitro and in vivo antibacterial spectra including anti-methicillin-resistant Staphylococcus aureus (MRSA) activity. The latter cephalosporin (2b) also showed good in vitro and in vivo activities against Gram-positive bacteria, especially against S. aureus A15036, a strain of MRSA, the in vivo activity being comparable to vancomycin but was lacking in anti-pseudomonal activity.


Assuntos
Cefalosporinas/síntese química , Cefalosporinas/farmacocinética , Animais , Infecções Bacterianas/tratamento farmacológico , Ceftazidima/farmacologia , Cefalosporinas/sangue , Meia-Vida , Camundongos , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade
20.
J Antibiot (Tokyo) ; 46(4): 631-40, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8501006

RESUMO

Modifications at the sugar part of pradimicins were carried out by glycosidations of the aglycones or chemical transformations of natural pradimicins and their antifungal activity was evaluated. Among them, some of the D-xylose-modified derivatives (14, 17, 24) showed activity comparable to that of pradimicin A. The structure-activity relationships obtained through there studies clarified the role of the sugar part in the manifestation of antifungal activity: The 5-O-(6-deoxy-beta-D-sugar) is essential for activity and 2'-epi, 3'-oxo and 4'-deoxy sugar derivatives retain activity against yeasts.


Assuntos
Antibióticos Antineoplásicos/síntese química , Antibióticos Antineoplásicos/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Monossacarídeos/química , Dissacarídeos/química , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade
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