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1.
Am J Transplant ; 16(6): 1892-900, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26713513

RESUMEN

Abdominal wall transplantation (AWTX) has revolutionized difficult abdominal closure after intestinal transplantation (ITX). More important, the skin of the transplanted abdominal wall (AW) may serve as an immunological tool for differential diagnosis of bowel dysfunction after transplant. Between August 2008 and October 2014, 29 small bowel transplantations were performed in 28 patients (16 male, 12 female; aged 41 ± 13 years). Two groups were identified: the solid organ transplant (SOT) group (n = 15; 12 ITX and 3 modified multivisceral transplantation [MMVTX]) and the SOT-AWTX group (n = 14; 12 ITX and 2 MMVTX), with the latter including one ITX-AWTX retransplantation. Two doses of alemtuzumab were used for induction (30 mg, 6 and 24 h after reperfusion), and tacrolimus (trough levels 8-12 ng/mL) was used for maintenance immunosuppression. Patient survival was similar in both groups (67% vs. 61%); however, the SOT-AWTX group showed faster posttransplant recovery, better intestinal graft survival (79% vs. 60%), a lower intestinal rejection rate (7% vs. 27%) and a lower rate of misdiagnoses in which viral infection was mistaken and treated as rejection (14% vs. 33%). The skin component of the AW may serve as an immune modulator and sentinel marker for immunological activity in the host. This can be a vital tool for timely prevention of intestinal graft rejection and, more important, avoidance of overimmunosuppression in cases of bowel dysfunction not related to graft rejection.


Asunto(s)
Pared Abdominal/cirugía , Rechazo de Injerto/diagnóstico , Intestinos/trasplante , Complicaciones Posoperatorias , Síndrome del Intestino Corto/cirugía , Enfermedades de la Piel/patología , Adulto , Femenino , Rechazo de Injerto/etiología , Supervivencia de Injerto , Humanos , Masculino , Estudios Prospectivos , Síndrome del Intestino Corto/complicaciones , Enfermedades de la Piel/etiología , Resultado del Tratamiento
2.
Injury ; 54(10): 110923, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37478690

RESUMEN

BACKGROUND: The Masquelet technique is a surgical procedure for the reconstruction of bone defects. During the first step, an osteosynthetically stabilized defect is filled with a cement spacer. The spacer induces a foreign body membrane, called a Masquelet membrane. In a follow-up procedure, the spacer is replaced by a bone graft, which ossifies in the subsequent phase. MATERIAL AND METHODS: A total of 171 patients with 195 septic bone defects on the extremities that had been treated with the Masquelet procedure at the BG Klinikum in Hamburg, Germany, from 2011 to 2021 were retrospectively analysed, comparing patients who reached full weight and load bearing on the affected extremity to those who failed to do so. Defect size and configuration, microbiological results and treatment methods as well as comorbidities and epidemiologic data were analysed for factors influencing the treatment outcome. RESULTS: In all, 113[66%] of the patients were male, and 58[34%] were female, with an age distribution of 52 +/-16 years. Out of 171 patients, 24 patients had two defects. The number of patients that reached full weight bearing was 152[89%], the follow-up period was 2 +/-1 years (median +/- SD). Full weight bearing capability was negatively by the defect size as defects >62 mm tended to be less likely to reach full weight bearing than smaller defects. A secondary stabilization with an internal stabilization was applied in 58[34%] of all patients and positively influenced the attainment of full weight and load bearing. DISCUSSION: With 171 patients and 195 septic bone defects treated at a single centre with the Masquelet Technique, this study represents a comparably large cohort. Demographics, defect characteristics and treatment outcomes did not differ from those of other cohorts described in the literature. Defects larger than 62 mm showed lower chances to reach full weight bearing and can be defined as "critical defect size" for the Masquelet technique based on our data.


Asunto(s)
Trasplante Óseo , Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Estudios Retrospectivos , Resultado del Tratamiento , Trasplante Óseo/métodos , Alemania
3.
Am J Transplant ; 11(5): 1041-50, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21521472

RESUMEN

We reported the successful administration of infliximab for late-onset OKT3-resistant rejection in two patients, who presented persistent ulcerative inflammation of the ileal graft after intestinal transplantation (ITX). Based on this experience, the present study demonstrated our long-term experience with infliximab for different types of rejection-related and inflammatory allograft alterations. Infliximab administration (5 mg/kg body weight (BW)) was initiated at a mean of 18.2 ± 14.1 months after transplantation. The number of administrations per patient averaged 8.4 ± 6.7. Repeat dosing was timed according to clinical signs and graft histology in addition to serum-levels of tumor necrosis factor alpha (TNFα), lipopolysaccharide binding protein (LBP) and C-reactive protein (CRP). Infliximab was successful in the following patients: patients with late-onset OKT3- and steroid-refractory rejection who presented persistent ulcerative alterations of the ileal graft (n = 5), patients with ulcerative ileitis/anastomositis, who did not show typical histological rejection signs (n = 2), and one patient with early-onset OKT3-resistant rejection. Infliximab was not successful in one patient with early-onset OKT3-resistant rejection that was accompanied by treatment-refractory humoral rejection. In conclusion, infliximab can expand therapeutic options for late-onset OKT3- and steroid-refractory rejection and chronic inflammatory graft alterations in intestinal allograft recipients.


Asunto(s)
Inmunosupresores/uso terapéutico , Intestinos/trasplante , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Proteínas de Fase Aguda/metabolismo , Adulto , Anticuerpos Monoclonales/uso terapéutico , Peso Corporal , Proteína C-Reactiva/metabolismo , Proteínas Portadoras/metabolismo , Femenino , Rechazo de Injerto , Supervivencia de Injerto , Humanos , Sistema Inmunológico , Inflamación , Infliximab , Masculino , Glicoproteínas de Membrana/metabolismo , Esteroides/farmacología , Trasplante Homólogo , Resultado del Tratamiento
4.
Unfallchirurg ; 114(7): 597-603, 2011 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-21153388

RESUMEN

AIM: Osteitis of the clavicle is rare and not well described in the international literature. We describe a concept of surgical treatment with medium-term observations. METHOD: A total of 22 patients (12 women, 10 men; BMI Ø 24.6 kg/m(2), age Ø 48 years) with osteitis of the clavicle were included in the series. The treatment regime consisted of a surgical approach. Data collection was prospective. Data gathered preoperatively and at follow-up included clinical examination, laboratory findings, radiographs and the Constant scoring system. The mean follow-up period was 13.3 (3-53) months. RESULTS: The described surgical concept was able to permanently eliminate infection in all cases studied. Surgical revisions were required in six patients. The average Constant score showed a significant increase from 66 to 84 at follow-up. Patients also showed good functional results after total resection of the clavicle. CONCLUSION: The reported treatment regime provides reliable results in terms of eliminating infection with good clinical results. Neighboring joints were frequently also involved in the infection and needed to be surgically addressed.


Asunto(s)
Clavícula/lesiones , Clavícula/cirugía , Fracturas Óseas/cirugía , Osteítis/cirugía , Femenino , Estudios de Seguimiento , Fracturas Óseas/etiología , Humanos , Masculino , Persona de Mediana Edad , Osteítis/complicaciones , Resultado del Tratamiento
5.
Eur J Med Res ; 15(2): 54-8, 2010 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-20452884

RESUMEN

Although there is a clear trend toward internal fixation for ankle arthrodesis, there is general consensus that external fixation is required for cases of posttraumatic infection. We retrospectively evaluated the technique and clinical long term results of external fixation in a triangular frame for cases of posttraumatic infection of the ankle. From 1993 to 2006 a consecutive series of 155 patients with an infection of the ankle was included in our study. 133 cases of the advanced "Gächter" stage III and IV were treated with arthrodesis. We treated the patients with a two step treatment plan. After radical debridement and sequestrectomy the malleoli and the joint surfaces were resected. An AO fixator was applied with two Steinmann-nails inserted in the tibia and in the calcaneus and the gap was temporary filled with gentamicin beads as the first step. In the second step we performed an autologous bone graft after a period of four weeks. The case notes were evaluated regarding trauma history, medical complaints, further injuries and illnesses, walking and pain status and occupational issues. Mean age at the index procedure was 49.7 years (18-82), 104 patients were male (67.1%). Follow up examination after mean 4.5 years included a standardised questionnaire and a clinical examination including the criteria of the AOFAS-Score and radiographs. 92.7% of the cases lead to a stable arthrodesis. In 5 patients the arthrodesis was found partly-stable. In six patients (4,5%) the infection was not controllable during the treatment process. These patients had to be treated with a below knee amputation. The mean AOFAS score at follow up was 63.7 (53-92). Overall there is a high degree of remaining disability. The complication rate and the reduced patient comfort reserve this method mainly for infection. Joint salvage is possible in the majority of cases with an earlier stage I and II infection.


Asunto(s)
Traumatismos del Tobillo/cirugía , Articulación del Tobillo/cirugía , Artrodesis/métodos , Fijadores Externos , Infecciones Estafilocócicas/cirugía , Fracturas de la Tibia/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Traumatismos del Tobillo/complicaciones , Traumatismos del Tobillo/diagnóstico por imagen , Articulación del Tobillo/diagnóstico por imagen , Antibacterianos/uso terapéutico , Trasplante Óseo , Femenino , Gentamicinas/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Reoperación , Estudios Retrospectivos , Infecciones Estafilocócicas/complicaciones , Infecciones Estafilocócicas/tratamiento farmacológico , Infección de la Herida Quirúrgica/complicaciones , Infección de la Herida Quirúrgica/cirugía , Fracturas de la Tibia/complicaciones , Resultado del Tratamiento , Adulto Joven
6.
Chirurg ; 89(2): 159-170, 2018 02.
Artículo en Alemán | MEDLINE | ID: mdl-29305635

RESUMEN

Joint infections represent a severe complication that results in irreversible joint destruction when left untreated or treated inadequately. The reasons for joint infections include endogenous hematological and exogenous factors. In the patient cohort described here, the empyema was almost exclusively acquired through iatrogenic measures (e.g. arthroscopic operations, punctures and intra-articular infections) or as a result of fractures close to the joint and penetrating injuries. Acute joint empyema is an orthopedic emergency, which must be immediately surgically treated because irreversible cartilage damage can rapidly occur due to the pathophysiological process. Acute joint empyema must be treated arthroscopically. Chronic empyema must be assumed when the clinical symptoms last for more than 7 days. Chronic empyema should be treated by arthrotomy, synovectomy and removal of extraneous material including cruciate ligament replacement material.


Asunto(s)
Artritis Infecciosa , Empiema , Artritis Infecciosa/tratamiento farmacológico , Artroscopía , Humanos , Articulación de la Rodilla
7.
Circulation ; 100(21): 2184-90, 1999 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-10571978

RESUMEN

BACKGROUND: Recent in vitro studies have demonstrated regional differences in electrophysiological properties of individual left ventricular muscle layers. Controversy exists on the relevance of these findings for the situation in vivo. Thus, this study was designed to determine whether the in vivo canine heart exhibits regional differences in left ventricular refractoriness and in the susceptibility to sodium and potassium channel blockers. METHODS AND RESULTS: In 16 dogs, 36 needle electrodes (12 mm long, 4 bipolar electrodes, interelectrode distance 2.5 mm) were inserted into the left ventricular wall. By use of a computerized multiplexer-mapping system, the spread of activation in epicardial, endocardial, and midmyocardial muscle was reconstructed during ventricular pacing at 300- and 850-ms basic cycle length (BCL). Effective refractory periods (ERPs) were determined at baseline and after application of propafenone (2 mg/kg), dofetilide (30 microg/kg), or chromanol 293b (10 mg/kg) by the extrastimulus technique (BCL 300 and 850 ms). At baseline, activation patterns and ERPs were uniform in all muscle layers. Propafenone homogeneously decreased conduction velocity and moderately prolonged ERPs without any regional differences. Dofetilide and chromanol 293b did not affect the spread of activation. Dofetilide exhibited reverse use-dependent effects on ERP, still preserving transmural homogeneity of refractoriness. Chromanol 293b led to a regionally uniform but more pronounced increase in local ERPs at faster than at slower pacing rates. CONCLUSIONS: At the heart rates applied, the in vivo canine heart does not exhibit regional differences in electrophysiological properties. Given the homogeneity of antiarrhythmic drug effects, induction of local gradients of refractoriness is obviously not a common mechanism of proarrhythmia in normal hearts.


Asunto(s)
Antiarrítmicos/farmacología , Cromanos/farmacología , Corazón/efectos de los fármacos , Fenetilaminas/farmacología , Bloqueadores de los Canales de Potasio , Propafenona/farmacología , Sulfonamidas/farmacología , Animales , Perros , Periodo Refractario Electrofisiológico/efectos de los fármacos
8.
J Am Coll Cardiol ; 36(3): 939-47, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10987623

RESUMEN

OBJECTIVES: This study sought to determine whether abnormal ventricular repolarization is implicated in cardiac arrhythmias of German shepherd dogs with inherited sudden death. BACKGROUND: Moïse et al. (9) have identified German shepherd dogs that display pause-dependent lethal ventricular arrhythmias. METHODS: Ventricular repolarization was studied both in vivo using electrocardiogram recordings on conscious dogs and in vitro with a standard microelectrode technique performed on endomyocardial biopsies and Purkinje fibers. Pharmacological manipulation was used to evaluate the role of potassium channels. RESULTS: In control conditions, electrocardiogram parameters were similar in both groups of dogs, except for the PR interval (18% longer in affected dogs, p < 0.05). Injection of d,l-sotalol (2 mg/kg) prolonged QT interval more in affected dogs (+14%, n = 9) than it did in unaffected dogs (+6%, n = 6, p < 0.05) and increased the severity of arrhythmias in affected dogs. In vitro, in control conditions, action potential duration (APD90) of endomyocardial biopsies and Purkinje fibers were significantly longer in affected dogs (respectively 209 +/- 3 ms, n = 30 and 352 +/- 15 ms, n = 17) than they were in unaffected dogs (197 +/- 4 ms, n = 25 and 300 +/- 9 ms, n = 30) at a pacing cycle length (PCL) of 1,000 ms. This difference increased with PCL. The kinetics of adaptation of APD90 to a change in PCL was faster in affected dogs. D,l-sotalol (10(-5) and 10(-4)M) increased APD90 in both groups of dogs, but this increase was greater in affected dogs, with the occurrence of triggered activity on Purkinje fibers. E-4031 (10(-7) and 10(-6) M), an I(Kr)-blocker, increased APD90 similarly in both groups of dogs. Chromanol 293B (10(-6) and 10(-5)M), an I(Ks)-blocker, increased significantly APD90 in unaffected dogs but had no effect in affected dogs. CONCLUSIONS: These results support the hypothesis of an abnormal cardiac repolarization in affected dogs. The effects of 293B suggest that I(Ks) may be involved in this anomaly.


Asunto(s)
Arritmias Cardíacas/veterinaria , Muerte Súbita Cardíaca/veterinaria , Enfermedades de los Perros/genética , Enfermedades de los Perros/fisiopatología , Bloqueadores de los Canales de Potasio , Animales , Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/tratamiento farmacológico , Arritmias Cardíacas/genética , Arritmias Cardíacas/fisiopatología , Cromanos/uso terapéutico , Enfermedades de los Perros/tratamiento farmacológico , Perros , Electrocardiografía , Endocardio/efectos de los fármacos , Endocardio/patología , Endocardio/fisiopatología , Corazón/efectos de los fármacos , Corazón/fisiopatología , Técnicas In Vitro , Miocardio/patología , Piperidinas/uso terapéutico , Ramos Subendocárdicos/fisiopatología , Piridinas/uso terapéutico , Valores de Referencia , Sotalol/uso terapéutico , Sulfonamidas/uso terapéutico
9.
Atherosclerosis ; 86(1): 55-68, 1991 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2064636

RESUMEN

Cells with enhanced levels of collagen type I and III mRNA were identified and localized in frozen tissue sections from samples of human atherosclerotic renal and common iliac arteries by in situ hybridization using complementary 35S-labeled RNA probes. Serial sections were immunohistochemically stained for smooth muscle cells, monocytes, and differentiated macrophages. In the fibromuscular intima and in the fibrous plaques, cells with enhanced transcriptional activity were located mainly in the vicinity of differentiated macrophages. In three patients, lack of enhanced transcriptional activity in a proliferated intima was connected with complete absence of macrophages, thus indicating a quiescent stage of atherosclerosis. Immunohistochemical staining of serial sections for smooth muscle cells (SMC) revealed the presence of this cell type throughout the proliferated intima in atherosclerotic arteries including those areas in which enhanced collagen mRNAs were detected. The present results support the idea that macrophages play an important role in the activation of collagen synthesis in SMC of atherosclerotic vessel walls.


Asunto(s)
Arteriosclerosis/metabolismo , Colágeno/genética , Arteria Ilíaca/metabolismo , ARN Mensajero/metabolismo , Arteria Renal/metabolismo , Adolescente , Adulto , Anciano , Arteriosclerosis/genética , Arteriosclerosis/patología , Colágeno/metabolismo , ADN/metabolismo , Femenino , Humanos , Arteria Ilíaca/patología , Inmunohistoquímica , Macrófagos/metabolismo , Macrófagos/patología , Masculino , Persona de Mediana Edad , Hibridación de Ácido Nucleico , Arteria Renal/patología
10.
J Med Chem ; 44(7): 1085-98, 2001 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-11297455

RESUMEN

Sulfonylthioureas exhibiting cardioselective blockade of ATP-sensitive potassium channels (K(ATP) channels) were discovered by stepwise structural variations of the antidiabetic sulfonylurea glibenclamide. As screening assays, reversal of rilmakalim-induced shortening of the cardiac action potential in guinea pig papillary muscles was used to probe for activity on cardiac K(ATP) channels as the target, and membrane depolarization in CHO cells stably transfected with hSUR1/hKir6.2 was used to probe for unwanted side effects on pancreatic K(ATP) channels. Changing glibenclamide's para-arrangement of substituents in the central aromatic ring to a meta-pattern associated with size reduction of the substituent at the terminal nitrogen atom of the sulfonylurea moiety was found to achieve cardioselectivity. An additional change from a sulfonylurea moiety to a sulfonylthiourea moiety along with an appropriate substituent in the ortho-position of the central aromatic system was a successful strategy to further improve potency on the cardiac K(ATP) channel. Among this series of sulfonylthioureas HMR1883, 1-[5-[2-(5-chloro-o-anisamido)ethyl]-2-methoxyphenyl]sulfonyl-3-methylthiourea, and its sodium salt HMR1098 were selected for development and represent a completely new therapeutic approach toward the prevention of life-threatening arrhythmias and sudden cardiac death in patients with coronary heart disease.


Asunto(s)
Transportadoras de Casetes de Unión a ATP , Adenosina Trifosfato/metabolismo , Antiarrítmicos/síntesis química , Bloqueadores de los Canales de Potasio , Canales de Potasio de Rectificación Interna , Canales de Potasio , Sulfonamidas/síntesis química , Tiourea/síntesis química , Potenciales de Acción/efectos de los fármacos , Animales , Antiarrítmicos/química , Antiarrítmicos/farmacología , Arritmias Cardíacas/prevención & control , Células CHO , Cricetinae , Muerte Súbita/prevención & control , Estimulación Eléctrica , Femenino , Cobayas , Corazón/efectos de los fármacos , Corazón/fisiología , Técnicas In Vitro , Masculino , Contracción Miocárdica/efectos de los fármacos , Receptores de Droga/antagonistas & inhibidores , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/farmacología , Receptores de Sulfonilureas , Tiourea/análogos & derivados , Tiourea/química , Tiourea/farmacología
11.
J Med Chem ; 44(23): 3831-7, 2001 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-11689069

RESUMEN

Since the discovery of the I(Ks)-potassium channel as the slowly activating component of the delayed rectifier current (I(k)) in cardiac tissue, the search for blockers of this current has been intense. During the screening of K(ATP)-channel openers of the chromanol type we found that chromanol 293B was able to block I(Ks). Chromanol 293B is a sulfonamide analogue of the K(ATP)-channel openers but had no activity on this target. Experiments were initiated to improve the activity and properties based on this lead compound. As a screening model we used Xenopus oocytes injected with human minK (KCNE1). Variations of the aromatic substituent and the sulfonamide group were prepared, and their activity was evaluated. We found that the greatest influence on activity was found in the aromatic substituents. The most active compounds were alkoxy substituted. We chose HMR1556 ((3R, 4S)-(+)-N-[-3-hydroxy-2,2-dimethyl-6-(4,4,4-trifluorobutoxy)chroman-4-yl]-N-methyl-ethanesulfonamide) 10a for development as an antiarrhythmic drug. The absolute configuration, resulting from an X-ray single-crystal structure analysis, was determined.


Asunto(s)
Cromanos/síntesis química , Bloqueadores de los Canales de Potasio , Bloqueadores de los Canales de Potasio/síntesis química , Canales de Potasio con Entrada de Voltaje , Sulfonamidas/síntesis química , Animales , Cromanos/química , Cromanos/farmacología , Cristalografía por Rayos X , Evaluación Preclínica de Medicamentos , Humanos , Técnicas In Vitro , Oocitos/efectos de los fármacos , Oocitos/metabolismo , Oocitos/fisiología , Técnicas de Placa-Clamp , Bloqueadores de los Canales de Potasio/química , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio/metabolismo , Relación Estructura-Actividad , Sulfonamidas/química , Sulfonamidas/farmacología , Xenopus laevis
12.
Br J Pharmacol ; 131(8): 1503-6, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11139424

RESUMEN

Slowly activating I:(Ks) (KCNQ1/MinK) channels were expressed in Xenopous: oocytes and their sensitivity to chromanols was compared to homomeric KCNQ1 channels. To elucidate the contribution of the ss-subunit MinK on chromanol block, a formerly described chromanol HMR 1556 and its enantiomer S5557 were tested for enantio-specificity in blocking I:(Ks) and KCNQ1 as shown for the single enantiomers of chromanol 293B. Both enantiomers blocked homomeric KCNQ1 channels to a lesser extent than heteromeric I:(Ks) channels. Furthermore, we expressed both WT and mutant MinK subunits to examine the involvement of particular MinK protein regions in channel block by chromanols. Through a broad variety of MinK deletion and point mutants, we could not identify amino acids or regions where sensitivity was abolished or strikingly diminished (>2.5 fold). This could indicate that MinK does not directly take part in chromanol binding but acts allosterically to facilitate drug binding to the principal subunit KCNQ1.


Asunto(s)
Cromanos/farmacología , Canales de Potasio con Entrada de Voltaje , Canales de Potasio/efectos de los fármacos , Animales , Cromanos/química , Relación Dosis-Respuesta a Droga , Femenino , Canales de Potasio KCNQ , Canal de Potasio KCNQ1 , Potenciales de la Membrana/efectos de los fármacos , Mutación , Oocitos/efectos de los fármacos , Oocitos/fisiología , Canales de Potasio/genética , Canales de Potasio/fisiología , ARN Complementario/administración & dosificación , ARN Complementario/genética , Estereoisomerismo , Xenopus
13.
Naunyn Schmiedebergs Arch Pharmacol ; 362(6): 480-8, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11138839

RESUMEN

Chromanol HMR 1556 [(3R,4S)-(+)-N-[3-hydroxy-2,2-dimethyl-6-(4,4,4-trifluorobutoxy)chroman-4-yl]-N-methylmethanesulfonamide], a novel inhibitor of the slow component of the delayed outward current in heart muscle cells (IKs), has been characterized in several in-vitro systems. mRNA encoding for the human protein minK was injected into Xenopus oocytes, leading to the expression of IKs channels. HMR 1556 inhibited this current half-maximally at a concentration of 120 nmol/l (IC50). Expression of the K+ channels Herg, Kv 1.5, Kv 1.3 and Kir2.1, and also the cationic current HCN2, were blocked little or not at all by 10 micromol/l HMR 1556. In isolated ventricular myocytes from the guinea pig the whole-cell patch-clamp method revealed inhibition of the IKs current with an IC50, of 34 nmol/l. Other current components, like IKr and IK1. were only slightly blocked at an HMR 1556 concentration of 10 micromol/l, whereas 10 micromol/l HMR 1556 inhibited the transient outward current I(to) and the sustained outward current I(sus) in rat ventricular myocytes by 25% and 36%, respectively. The L-type Ca2+ channel in guinea pig cardiomyocytes was blocked by 10 micromol/l HMR 1556 by 31%. Guinea pig right papillary muscles were investigated by the micropuncture technique at various pacing rates. In the frequency range of 0.5-7 Hz HMR 1556 (1 micromol/l) caused a prolongation of the action potential duration at 90% repolarization (APD90) by 19%-27%. In the presence of isoproterenol (10 micromol/l) the prolongation of the APD90 was more pronounced at low pacing rates (47% at 0.5 Hz and 35% at 1 Hz, compared with 25% at 7 Hz). The monophasic action potential was recorded in Langendorff-perfused guinea pig hearts. In spontaneously beating preparations, HMR 1556, at 0.1 micromol/l and 1 micromol/l, prolonged the MAPD90 by 3% and 10%, respectively, with no further prolongation at 10 micromol/l. The prolongation was much greater at low pacing rates [25% at 100 beats per min (bpm) and 13% at 150 bpm] than at fast pacing rates (9% at 350 bpm). The left ventricular pressure LVPmax was not affected at 1 micromol/l HMR 1556, but it decreased by 15% at 10 micromol/l. Other parameters, like the heart rate and coronary flow, were only slightly decreased at 1 micromol/l HMR 1556. In conclusion, HMR 1556 is a potent and selective inhibitor of the IKs current in guinea pig ventricular myocytes. The prolongation of the action potential duration is maintained at fast pacing rates.


Asunto(s)
Cromanos/farmacología , Bloqueadores de los Canales de Potasio , Canales de Potasio con Entrada de Voltaje , Sulfonamidas/farmacología , Animales , Función Atrial , Cobayas , Corazón/efectos de los fármacos , Corazón/fisiología , Atrios Cardíacos/efectos de los fármacos , Humanos , Técnicas In Vitro , Concentración 50 Inhibidora , Miocardio/citología , Oocitos/efectos de los fármacos , Oocitos/fisiología , Músculos Papilares/efectos de los fármacos , Músculos Papilares/fisiología , Técnicas de Placa-Clamp , Perfusión , Canales de Potasio/genética , Canales de Potasio/metabolismo , Canales de Potasio/fisiología , Ramos Subendocárdicos/efectos de los fármacos , Ramos Subendocárdicos/fisiología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Conejos , Xenopus laevis
14.
Clin Chim Acta ; 144(1): 1-10, 1984 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-6542469

RESUMEN

A radioimmunoassay was developed for the detection of 7 S collagen, a basement membrane component derived from type IV collagen, in sera of patients. Two forms of 7 S collagen were isolated by limited collagenase digestion of type IV collagen from bovine placenta. Antisera against both forms were raised in rabbits. The antigens were labeled by conjugation with the Bolton Hunter reagent or by the Chloramine T method. Free and bound antigen were separated using a second antibody directed against rabbit-IgG. Serum concentrations of 7 S collagen ranged from 5-14 micrograms/l. Serum levels of 7 S collagen were increased in diabetic patients as compared to normal subjects.


Asunto(s)
Colágeno/sangre , Compuestos de Tosilo , Adolescente , Adulto , Anciano , Cloraminas , Diabetes Mellitus/sangre , Humanos , Persona de Mediana Edad , Peso Molecular , Radioinmunoensayo , Succinimidas
15.
Artículo en Inglés | MEDLINE | ID: mdl-15326915

RESUMEN

Prolongation of the cardiac action potential and the effective refractory period is a proven principle to prevent cardiac arrhythmias, especially under conditions when the action potential is shortened. Several approaches have been made to achieve this effect selectively and without proarrhythmic side effects. Besides the blockade of the cardiac sodium channel, blockade of the delayed rectifier potassium channel I(K) was attempted to achieve this goal. After the discovery that the delayed rectifier potassium channel I(K) consists of two distinct channels, the rapidly and the slowly delayed rectifier potassium channel I(Kr) and I(Ks) respectively, blockers for these targets were looked for. But most of the described blockers of I(K), like dofetilide and D-sotalol, are highly selective and potent I(Kr) channel blockers or have only a side-activity on the I(Ks) channel, as described for azimilide. These compounds have shown their efficacy in terminating atrial or ventricular fibrillation under certain circumstances, but they also have shown high risk to induce arrhythmias by themselves. It was speculated that I(Ks) channel blockers may be free of this unwanted effect and several companies put effort to find compounds selective for this novel target. The strategies to find potent and selective I(Ks) channel will be reviewed as well as their first results in in-vitro and in-vivo models of arrhythmia. As side effects are a potential danger for this ubiquitous channel, also the safety studies with these compounds will be summarized.


Asunto(s)
Antiarrítmicos/química , Arritmias Cardíacas/tratamiento farmacológico , Bloqueadores de los Canales de Potasio/química , Canales de Potasio con Entrada de Voltaje , Canales de Potasio/metabolismo , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Antiarrítmicos/farmacología , Benzamidas , Benzodiazepinas/química , Benzodiazepinas/farmacología , Cromanos/química , Cromanos/farmacología , Muerte Súbita Cardíaca , Canales de Potasio de Tipo Rectificador Tardío , Humanos , Estructura Molecular , Bloqueadores de los Canales de Potasio/farmacología
16.
Clin Rheumatol ; 13(1): 90-7, 1994 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8187452

RESUMEN

Rheumatoid arthritis is a complex disease of unknown origin. In consequence of some immunological reactions, proliferative invading synovial tissue leads to destruction of normal joint architecture. The aim of this study was to investigate qualitative changes in extracellular matrix distribution of proliferating rheumatoid synovium and their cellular origin. Synovial tissues from 57 clinically indicated arthrotomies were investigated with immunofluorescence, using specific antibodies against extracellular matrix proteins in tissue slides and cultured cells, which were also studied for collagen biosynthesis. Results indicated that synovial fibroblast-like cells synthesize and secrete basement membrane proteins laminin and collagen type IV as e.g. endothelial cells or organogenic fibroblasts. Laminin and collagen type IV were specifically demonstrated pericellularly in the hyperplastic lining layer of active rheumatoid synovitis. These findings are discussed with respect to the possible implication of altered cell-matrix interactions in rheumatoid synovial proliferation.


Asunto(s)
Artritis Reumatoide/patología , Fibroblastos/metabolismo , Proteínas de la Membrana/análisis , Proteínas de la Membrana/biosíntesis , Membrana Sinovial/química , Artritis Reumatoide/metabolismo , Membrana Basal/química , Radioisótopos de Carbono , Células Cultivadas , Colágeno/química , Matriz Extracelular/química , Fibronectinas/análisis , Técnica del Anticuerpo Fluorescente , Humanos , Osteoartritis/metabolismo , Péptidos/análisis
17.
Hepatogastroenterology ; 27(6): 465-7, 1980 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-7203379

RESUMEN

Isoenzymes of N-acetyl-beta-glucosaminidase were separated in the supernatant of 72 homogenized normal and fibrotic human liver. Patterns of isoenzymes were obtained by electrofocusing in thin layers of polyacrylamide gel. The activity of mesenchymal reaction in the liver tissue was determined by histological examination. The distribution of N-acetyl-beta-glucosaminidase isoenzymes was compared with the mesenchymal activity in the liver tissue. The results show a good correlation of isoenzyme A activity with mesenchymal activity.


Asunto(s)
Acetilglucosaminidasa/metabolismo , Hexosaminidasas/metabolismo , Isoenzimas/metabolismo , Hepatopatías/enzimología , Hígado/enzimología , Enfermedad Crónica , Humanos
18.
Hepatogastroenterology ; 36(6): 506-10, 1989 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2693303

RESUMEN

Chronic liver diseases are characterized by an increase in connective tissue components in liver tissue. The determination of Col 1-3 peptide of type III procollagen (P-III-P) in serum of patients seems to be a useful parameter of hepatic fibroplasia. Specific radioimmunoassays are available for Col 1-3 (P-III-P) and the Col 1 and Col 1-3 (P-III-P-Fab) peptides of type III procollagen and for laminin P1 fragment. These proteins and the activity of N-acetyl-beta-glucosaminidase (beta-NAG) were measured in 94 patients with chronic liver diseases, and in 74 healthy controls. In addition, direct immunofluorescence studies were done for laminin P1 in normal and fibrotic liver tissues. In normal human liver, laminin was found in the basement membrane of bile ducts and in blood vessel walls. In fibrotic liver tissue, laminin additionally occurred in periportal areas and in sinusoids co-distributed with other connective tissue components. In serum concentrations of P-III-P, P-III-P-Fab and laminin were higher in patients than in healthy subjects. Laminin concentration was increased in early stages of chronic liver disease, possibly as a marker of regeneration; the highest concentrations were in active cirrhosis and chronic active hepatitis. The determination of P-III-P and P-III-P-Fab provided information on synthesis and degradation of type III collagen: In inactive cirrhosis, Col 1 peptide was increased in relation to Col 1-3 peptide.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Acetilglucosaminidasa/sangre , Hígado Graso/sangre , Hepatitis Crónica/sangre , Hexosaminidasas/sangre , Laminina/sangre , Cirrosis Hepática/sangre , Fragmentos de Péptidos/sangre , Procolágeno/sangre , Adulto , Hígado Graso/patología , Femenino , Técnica del Anticuerpo Fluorescente , Hepatitis Crónica/patología , Humanos , Hígado/patología , Cirrosis Hepática/patología , Masculino , Persona de Mediana Edad , Radioinmunoensayo
19.
Hepatogastroenterology ; 45(24): 2282-94, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9951911

RESUMEN

BACKGROUND/AIMS: Alpha-interferon (IFN-alpha) is an effective treatment for chronic hepatitis B but only 25-40% of patients will profit from a long-term beneficial response to the currently recommended schedule of 3-6 MU given 3 times a week for 6 months. Clinical trials are therefore needed to investigate alternative modifications of interferon therapy, including combinations of different antivirals or immune modulators in order to improve the therapeutic approach to chronic hepatitis B infection. In a phase II trial we evaluated whether a combination of natural interferon-beta (nIFN-beta) with strong antiviral activity plus recombinant interferon-gamma (rIFN-gamma) with a predominantly immunomodulatory activity is able to increase the response rate compared to historical controls treated with IFN-alpha in a conventional regimen. METHODOLOGY: Forty patients with chronic hepatitis B were included in this trial of combined interferon therapy at a dosage of 6 MU nIFN-beta during week 1 followed by 3 MU for weeks 2-4 plus rIFN-gamma at a daily subcutaneous (s.c.) injection of 150 microg during the entire 4 weeks of the treatment period. Patients entered the trial on the basis of the following criteria: hepatitis B surface antigen (HBsAG), HBeAG and HBV-DNA positive for at least 6 months, HDV, EBV, CMV, anti-HIV negative, and chronic hepatitis proven on biopsy taken within 4 weeks of entry as well as 6 and/or 12 months after interferon therapy. The final diagnosis and classification of chronic hepatitis has been based on guidelines according to a revised classification of chronic hepatitis (Desmet 1994). The post-treatment follow-up was 12 months. RESULTS: The combined interferon therapy achieved complete responses with seroconversion from HBeAG to anti-HBe and a negative HBV-DNA (dot blot) test, as well as normalization of ALT activity in 15 patients, and partial response with negativation of HBV-DNA concomitant to a decrease in aminotransferase activity to near normal levels in 6 patients. Nineteen patients showed no response to viral markers but showed relief of clinical symptoms as well as pronounced decrease of serumtransaminase activity. Grading of liver biopsies demonstrated an improvement of histologic parameters after the interferon regimen in half of the evaluable patients (n=22). Histological response has been quantified by a reduction in the score of histological activity (HAI-index) from 12.6 before to 7.6 after interferon therapy, and in the inflammation and cellular degeneration score (ICD) from 9.9 to 5.2. Histological response, however, failed to show a consistent correlation with serologic response. This medium-dose combination of interferon-beta and interferon-gamma was tolerated very well by the patients, this good tolerability being explained by tachyphylaxis in response to daily interferon doses. No serious side effects or decompensation of liver function were observed during the 4-week period of therapy or the follow-up, despite the special clinical situation where 60% of the patients included in the study presented with histologically proven cirrhosis (35% of them with clinical manifestation of mildly decompensated cirrhosis). CONCLUSIONS: This short-term regimen of combined nIFN-beta + rIFN-gamma therapy in patients with chronic hepatitis B proved to be equieffective to long-term treatment with interferon-alpha and combines high clinical tolerability with good practicability, as it can be administered on an in-patient basis, ensuring close patient monitoring.


Asunto(s)
Hepatitis B Crónica/terapia , Interferón-alfa/administración & dosificación , Interferón gamma/administración & dosificación , Adolescente , Adulto , Anciano , Biopsia , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Quimioterapia Combinada , Femenino , Hepatitis B Crónica/patología , Humanos , Interferón-alfa/efectos adversos , Interferón gamma/efectos adversos , Hígado/patología , Pruebas de Función Hepática , Masculino , Persona de Mediana Edad , Proteínas Recombinantes , Resultado del Tratamiento
20.
Int J Tissue React ; 9(4): 355-9, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3497902

RESUMEN

The concentration of granulocyte elastase-alpha-1-protease inhibitor (E-AT) complex in plasma is enhanced in inflammatory processes, e.g. in septicaemia and rheumatoid arthritis, being an expression of granulocyte activation during inflammatory response. In the present study we measured E-AT and fibronectin in the plasma of 46 patients with various connective-tissue diseases in relation to the course of the disease. In about 50% of the cases, E-AT was found to be elevated to 2-3 times the normal concentrations, in relation to increasing serum content of C-reactive protein. In follow-ups over 2 years, an elevation of E-AT and a decreasing fibronectin in plasma was found in patients with activated disease. Without relation to other parameters used in connective-tissue diseases, fibronectin was found to be diminished below the normal range in 7 patients with systemic lupus erythematodes and 1 patient with overlapping syndrome. Our results indicate that the concentration of E-AT and fibronectin in plasma may be helpful parameters for judging the activity of connective-tissue diseases.


Asunto(s)
Proteínas Sanguíneas , Enfermedades del Tejido Conjuntivo/sangre , Fibronectinas/sangre , Elastasa Pancreática/sangre , Inhibidores de Proteasas/sangre , Adolescente , Adulto , Dermatomiositis/sangre , Femenino , Granulocitos/enzimología , Humanos , Lupus Eritematoso Sistémico/sangre , Masculino , Persona de Mediana Edad , Esclerodermia Sistémica/sangre , alfa 1-Antitripsina
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