Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Scand J Rheumatol ; : 1-8, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38993122

RESUMEN

OBJECTIVE: Diabetic cheiroarthropathy (DCA) is one of the musculoskeletal manifestations of diabetes mellitus. It is clinically diagnosed using the prayer and tabletop signs. The clinical appearance, however, mimics autoimmune-mediated polyarthritis of the hands and fingers. It is therefore crucial to positively identify DCA patients. METHOD: We used high-frequency B-mode ultrasound to investigate 14 patients with DCA and seven non-DCA diabetics with anti-cyclic citrullinated peptide antibody-positive rheumatoid arthritis (RA). We recorded the frequency of synovitis in radiocarpal, metacarpophalangeal, and proximal interphalangeal joints, the presence of tenosynovitis of the finger flexor tendons, echogenicity of the synovia and the flexor tendon sheaths, and soft tissue alterations in the digits. We compared our findings between groups to determine sonographic characteristics of DCA. RESULTS: A low rate of small finger joint involvement in the presence of a high rate of finger flexor tendinopathy showed a high association with DCA in correlation (p = 0.002) and regression analysis (p < 0.001). Tendon sheaths were significantly more often hyperechoic and proliferative in DCA compared to RA (p = 0.008), and hypoechoic soft tissue alterations were almost exclusively seen in DCA patients (p = 0.003). Radiocarpal joint involvement and its echogenicity did not differ between groups. CONCLUSION: Ultrasonography shows typical features in DCA, and is capable of discriminating DCA from non-DCA patients with RA and diabetes.

2.
Scand J Rheumatol ; 52(3): 276-282, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-35383517

RESUMEN

OBJECTIVE: There is a strong unmet need for biomarkers in giant cell arteritis (GCA), as C-reactive protein (CRP) may be unreliable in patients treated with Tocilizumab (TCZ). We aimed to assess whether C3 and C4 are useful biomarkers in GCA patients, particularly in those treated with TCZ. METHOD: We retrospectively enrolled all patients who underwent C3 and C4 measurement at baseline. All patients were evaluated at 3, 6, 12, and 24 months after diagnosis, as part of routine follow-up. Two assessments after the end of the observational period, in case of further relapses, were also included. RESULTS: At baseline, mean ± sd levels (mg/dL) of C3 (133 ± 28.99) and C4 (25.9 ± 9.04) were within normal ranges. During follow-up, C3 and C4 decreased in patients attaining remission (107.07 ± 19.86, p = 0.0006; 19.86 ± 10.27, p = 0.01, respectively) and sustained remission (95.85 ± 18.04, p = 0.001; 15.61 ± 9.75, p = 0.006). In TCZ-treated patients, even stronger decreases in C3 (83.11 ± 19.66, p = 0.001) and C4 (8.26 ± 3.83, p < 0.0001) were observed, and their values were not correlated with CRP or erythrocyte sedimentation rate. CONCLUSION: C3 and C4 do not seem useful in the diagnosis of GCA, as normal values do not rule out active vasculitis. However, C3 and C4 correlate with disease activity. As the low C4 levels found in TCZ-treated patients are not correlated with CRP, C4 should be evaluated as a potential biomarker of disease activity and treatment response.


Asunto(s)
Arteritis de Células Gigantes , Humanos , Arteritis de Células Gigantes/diagnóstico , Arteritis de Células Gigantes/tratamiento farmacológico , Estudios Retrospectivos , Biomarcadores , Proteína C-Reactiva/análisis , Factores Inmunológicos/uso terapéutico
3.
Z Rheumatol ; 78(10): 955-966, 2019 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-31485728

RESUMEN

Severe, organ-threatening and life-threatening manifestations of inflammatory rheumatic diseases, such as diffuse alveolar hemorrhage in the context of small vessel vasculitis, sometimes inadequately respond to immunosuppressive treatment. In the case of an immanent or already occurring organ failure, immunosuppressive treatment may need to be supplemented with rapidly effective rescue treatment procedures. Due to the rarity of many rheumatic diseases, the evidence for the use of rescue treatment, such as plasmapheresis, extracorporeal membrane oxygenation (ECMO) and the administration of intravenous immunoglobulins (IVIG), is relatively low for many indications. The use of plasmapheresis is considered useful in acute anti-glomerular basement membrane (GBM) disease (Goodpasture's syndrome) or catastrophic antiphospholipid antibody syndrome (APS). The use of ECMO treatment may be considered for persistent respiratory failure despite mechanical ventilation due to diffuse alveolar hemorrhage or acute respiratory distress syndrome (ARDS). Administration of IVIG is indicated for acute cardiac involvement in Kawasaki's disease and may be considered in catastrophic APS and refractory myositis.


Asunto(s)
Enfermedad por Anticuerpos Antimembrana Basal Glomerular , Oxigenación por Membrana Extracorpórea , Síndrome de Dificultad Respiratoria , Enfermedades Reumáticas , Humanos , Unidades de Cuidados Intensivos , Síndrome de Dificultad Respiratoria/complicaciones , Síndrome de Dificultad Respiratoria/terapia , Enfermedades Reumáticas/complicaciones , Enfermedades Reumáticas/terapia
4.
Z Rheumatol ; 77(9): 815-823, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29536155

RESUMEN

OBJECTIVE: In distinguishing urate arthritis (UA) from non-crystal-related arthritides, joint sonography including the detection of the double contour sign (DCS) and hypervascularization using power Doppler ultrasound (PDUS) is an important step in the diagnostic process. But are these sonographic features equally reliable in every accessible joint under real-life conditions? METHODS: We retrospectively analyzed 362 patients with acute arthritis and evaluated the DCS and the degree of PDUS hypervascularization in patients with gout and in those with arthritis other than urate arthritis (non-UA). We classified all joints into the groups small, medium, and large. Sensitivities, specificities, positive and negative predictive values (PPV/NPV), and a binary regression model were calculated. We also evaluated the influence of serum uric acid levels (SUA) on the presence of a DCS in each joint category. RESULTS: Sensitivity of the DCS in gout was 72.5% in the entire cohort, 66.0% in large, 78.8% in medium, and 72.3% in small joints. In wrist joints the DCS sensitivity maxed at 83.3%, with a specificity of 81.8%. The lowest rates of DCS sensitivity were found in gout patients with elbow joint involvement (42.9%). In all joints except metatarsophalangeal joint 1 (MTP-1), the incidence of a DCS increased by the increment of SUA levels above 7.5 mg/dl (p < 0.001). PDUS signals were most commonly found in medium and small joints and were only scarce in large joints, independent of the underlying diagnosis. CONCLUSIONS: In our study we detected different rates of accuracy regarding DCS and PDUS in patients with acute arthritis. The best results were seen in medium-size joints, especially wrists.


Asunto(s)
Artritis Gotosa , Artritis Gotosa/diagnóstico por imagen , Humanos , Masculino , Reproducibilidad de los Resultados , Estudios Retrospectivos , Ultrasonografía , Ácido Úrico
5.
Z Rheumatol ; 76(5): 398-407, 2017 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-28405755

RESUMEN

Renal involvement in sarcoidosis is much more common than generally assumed from old epidemiological studies and is often only detected when actively searched for. Many patients with renal sarcoidosis present with no or only few symptoms. The diagnostic work-up of sarcoidosis should always include a possible renal involvement. In cases of impaired renal function, proteinuria or a pathological urine sediment, a renal biopsy specimen should be obtained to assess the type, severity and prognosis of the kidney disease. Treatment is primarily based on the use of corticosteroids. Steroid-sparing agents, such as disease-modifying antirheumatic drugs and infliximab can be applied; however, the evidence for efficacy of these therapies is mostly based on case series and expert opinions. Discontinuation of immunosuppression therapy bears a high risk of relapse.


Asunto(s)
Corticoesteroides/administración & dosificación , Antiinflamatorios/administración & dosificación , Nefritis/diagnóstico , Nefritis/terapia , Sarcoidosis/diagnóstico , Sarcoidosis/terapia , Diagnóstico Diferencial , Medicina Basada en la Evidencia , Humanos , Resultado del Tratamiento
6.
Gesundheitswesen ; 77(12): 927-31, 2015 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-25268415

RESUMEN

AIM: Studies provide evidence for the importance of general practitioners (GPs) job satisfaction for a secure and high quality health care provision. This study focuses on job satisfaction of GPs in Mecklenburg-Western Pomerania (MV), a rural area threatened by a lack of GPs. We investigate how satisfied GPs are with their job and which factors influence their job satisfaction. METHODS: All 1 133 GPs working in MV in December 2011 were asked to complete a 57-item-questionnaire. The response rate reached 50.1%. RESULTS: The sample is representative for GPs in MV. Levels of job satisfaction are high and correlate with age and sex: females and GPs below 50 years of age are more satisfied. Factors contributing to high job satisfaction include a good doctor-patient relationship, fair pay, and the variety of reasons for doctor-patient consultations in primary care. Although all GPs were dissatisfied with bureaucracy, this factor has little impact on GPs' overall job satisfaction. CONCLUSION: In light of the imminent lack of GPs, in future it will be important to improve factors that have been demonstrated to increase job satisfaction.


Asunto(s)
Actitud del Personal de Salud , Médicos Generales/psicología , Médicos Generales/estadística & datos numéricos , Renta/estadística & datos numéricos , Satisfacción en el Trabajo , Carga de Trabajo/estadística & datos numéricos , Adulto , Distribución por Edad , Anciano , Estudios Transversales , Femenino , Medicina General/estadística & datos numéricos , Alemania , Humanos , Persona de Mediana Edad , Distribución por Sexo , Encuestas y Cuestionarios , Recursos Humanos , Carga de Trabajo/psicología , Adulto Joven
8.
Sarcoidosis Vasc Diffuse Lung Dis ; 31(4): 306-15, 2015 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-25591142

RESUMEN

BACKGROUND: Renal sarcoidosis (RS) is a possible manifestation of systemic sarcoidosis. The clinical presentation can range from asymptomatic individuals up to acute renal failure with the necessity of renal replacement therapy. The definite diagnosis must be established by renal biopsy. OBJECTIVES: Demonstration of clinical characteristics and effectiveness of steroid treatment. METHODS: We present a single center study of 27 patients with histologically proven RS. Firstly, we elaborate on descriptive features such as extra-renal organ involvement, calcium levels, renal function, proteinuria and histological subtypes and provide an histological assessment of renal damage. Secondly, we present follow-up data over a period of 2 years or more. RESULTS: Non-granulomatous tubulointerstitial nephritis (ngIN) was the most common histological entity (44%), followed by granulomatous IN (GIN, 30%), IgA-GN (26%) and nephrocalcinosis (11%). Under treatment with oral prednisone mean eGFR significantly improved from 38 ± 21 ml/min to 57 ± 26 ml/min and proteinuria decreased from 981 ± 304 mg/24 hrs to 176 ± 77 mg/24 hrs at the end of follow-up. In total, 62.5% of patients responded to therapy. CONCLUSIONS: We demonstrated that GIN is more often associated with advanced stages of renal insufficiency than any other histological manifestation of RS. Furthermore, prednisone therapy is effective in improving eGFR and in reducing total urinary protein secretion. We suggest that the key prognostic factor for renal survival in RS is the early response to treatment.


Asunto(s)
Enfermedades Renales/epidemiología , Riñón , Sarcoidosis/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Femenino , Estudios de Seguimiento , Alemania/epidemiología , Tasa de Filtración Glomerular , Glomerulonefritis por IGA/diagnóstico , Glomerulonefritis por IGA/tratamiento farmacológico , Glomerulonefritis por IGA/epidemiología , Glomerulonefritis por IGA/fisiopatología , Glucocorticoides/uso terapéutico , Humanos , Riñón/efectos de los fármacos , Riñón/patología , Riñón/fisiopatología , Enfermedades Renales/diagnóstico , Enfermedades Renales/tratamiento farmacológico , Enfermedades Renales/fisiopatología , Masculino , Persona de Mediana Edad , Nefritis Intersticial/diagnóstico , Nefritis Intersticial/tratamiento farmacológico , Nefritis Intersticial/epidemiología , Nefritis Intersticial/fisiopatología , Prednisona/uso terapéutico , Proteinuria/diagnóstico , Proteinuria/tratamiento farmacológico , Proteinuria/epidemiología , Proteinuria/fisiopatología , Recuperación de la Función , Inducción de Remisión , Insuficiencia Renal/diagnóstico , Insuficiencia Renal/tratamiento farmacológico , Insuficiencia Renal/epidemiología , Insuficiencia Renal/fisiopatología , Estudios Retrospectivos , Sarcoidosis/diagnóstico , Sarcoidosis/tratamiento farmacológico , Sarcoidosis/fisiopatología , Factores de Tiempo , Resultado del Tratamiento
9.
Oper Orthop Traumatol ; 27(6): 484-94, 2015 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-26572790

RESUMEN

OBJECTIVE: Reconstruction of the medial patellofemoral ligament with autologous tendon augmentation and soft tissue fixation at the patellar insertion with resorbable suture material. INDICATIONS: Patellofemoral instability due to insufficiency of the medial passive stabilizers and dysplastic trochlea. CONTRAINDICATIONS: Primary traumatic dislocation of the patella without risk factors for patellar redislocation, severe osteoarthritis of the patellofemoral joint, infection. SURGICAL TECHNIQUE: Diagnostic arthroscopy to evaluate cartilage and shape of trochlea and to treat associated injuries. Harvesting of the gracilis tendon and arming with resorbable suture material. Transfer of the tendon through the medial capsule in the anatomical layer of the MPFL and weaving in u-shape through the capsule and periosteum near the patella. Soft tissue fixation with resorbable suture material. Anatomical reconstruction of the femoral insertion site. Femoral fixation with interference screw. POSTOPERATIVE TREATMENT: For 4 weeks, partial (20 kg) weight bearing with crutches; cast with physiotherapy (limited ROM extension, flexion 0-0-90°). Thereafter free range of motion and full weight bearing. RESULTS: 27 patients (age 12-45 years) with patellofemoral instability underwent reconstruction of the medial patellofemoral ligament. Clinical follow-up was assessed up to 12 months postoperatively. After 1 year, the Kujala and Flandry scores increased from preoperatively 72 points to 95 points and 65.7 points to 89.9 points, respectively. One redislocation was observed. Patient satisfaction was significantly increased at 6 months postoperatively. Reconstruction of the medial patellofemoral ligament shows good clinical results after 12 months.


Asunto(s)
Inestabilidad de la Articulación/cirugía , Rótula/cirugía , Ligamento Rotuliano/cirugía , Articulación Patelofemoral/cirugía , Procedimientos de Cirugía Plástica/métodos , Tendones/trasplante , Adolescente , Adulto , Artroplastia/instrumentación , Artroplastia/métodos , Niño , Terapia Combinada/instrumentación , Terapia Combinada/métodos , Femenino , Músculo Grácil/trasplante , Humanos , Masculino , Persona de Mediana Edad , Osteotomía/instrumentación , Osteotomía/métodos , Articulación Patelofemoral/diagnóstico por imagen , Procedimientos de Cirugía Plástica/instrumentación , Técnicas de Sutura/instrumentación , Resultado del Tratamiento , Adulto Joven
10.
Br J Pharmacol ; 120(3): 476-80, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9031752

RESUMEN

1. The binding of the sulphonylurea [3H]-glibenclamide, a blocker of adenosine 5'-triphosphate (ATP)-sensitive K+ channels (KATP channels), was studied in endothelium-denuded rings from rat aorta. 2. [3H]-glibenclamide labelled two classes of binding sites with KD values of 20 +/- 5 nM and 32 +/- 1 microM. The high affinity component, which comprised 17% of total binding at 1 nM [3H]-glibenclamide, had an estimated binding capacity of 150 fmol mg-1 wet weight. 3. Other sulphonylureas such as glipizide and glibornuride and the sulphonylurea-related carboxylate, AZ-DF 265, inhibited high affinity [3H]-glibenclamide binding with the potencies expected from their K+ channel activity. At very high concentrations, AZ-DF 265 and glipizide started to interact also with the low affinity component of [3H]-glibenclamide binding. 4. Openers of the ATP-sensitive K+ channel belonging to different structural groups inhibited only the high affinity [3H]-glibenclamide binding; the potencies in this assay were similar to those obtained in functional (i.e. vasorelaxation) studies. 5. High affinity [3H]-glibenclamide binding was abolished by prolonged hypoxia combined with metabolic inhibition. 6. The data indicate that the high affinity component of [3H]-glibenclamide binding mediates the block of the KATP channel by the sulphonylureas in rat aorta; hence, it represents the sulphonylurea receptor in this vessel. The pharmacological properties of this binding site resemble those of the binding site for the openers of the KATP channel; present evidence suggests that these two classes of sites are negatively allosterically coupled.


Asunto(s)
Aorta Torácica/metabolismo , Músculo Liso Vascular/metabolismo , Receptores de Droga/metabolismo , Compuestos de Sulfonilurea/metabolismo , Adenosina Trifosfato/fisiología , Animales , Aorta Torácica/efectos de los fármacos , Unión Competitiva/efectos de los fármacos , Gliburida/metabolismo , Gliburida/farmacología , Hipoglucemiantes/metabolismo , Hipoglucemiantes/farmacología , Técnicas In Vitro , Cinética , Masculino , Músculo Liso Vascular/efectos de los fármacos , Canales de Potasio/efectos de los fármacos , Canales de Potasio/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de Droga/efectos de los fármacos , Compuestos de Sulfonilurea/farmacología
11.
Am J Med Genet ; 65(1): 56-9, 1996 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-8914742

RESUMEN

Karyotypes with an interstitial deletion and a marker chromosome formed from the deleted segment are rare. We identified such a rearrangement in a newborn infant, who presented with macrocephaly, asymmetric square skull, minor facial anomalies, omphalocele, inguinal hernias, hypospadias, and club feet. The karyotype 46,XY,del(5) (pter --> p13::cen --> qter)/47,XY,+dicr(5)(:p13 --> cen::p13 --> cen), del(5)(pter --> p13::cen --> qter) was identified by banding studies and FISH analysis in the peripheral lymphocytes. One breakpoint on the del(5) maps distal to GDNF, and FISH analysis using an alpha-satellite probe suggests that the proximal breakpoint maps within the centromere. The dicentric r(5) consists of two copies of the segment deleted in the del(5), resulting in trisomy of proximal 5p (5p13-cen). The phenotype of the propositus is compared with other trisomy 5p cases and possible mechanisms for the generation of this unique chromosomal rearrangement are discussed.


Asunto(s)
Anomalías Múltiples/genética , Deleción Cromosómica , Cromosomas Humanos Par 5 , Cromosomas en Anillo , Trisomía , Humanos , Hibridación Fluorescente in Situ , Recién Nacido , Masculino
12.
Am J Med Genet ; 103(2): 166-71, 2001 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-11568926

RESUMEN

Mutations in the human gene Jagged1 (JAG1) localized in 20p12 have been recently identified as causal for the anomalies found in patients with Alagille syndrome (AGS). This gene encodes a ligand for the Notch1 transmembrane receptor, which plays a key role in cell-to-cell signaling during differentiation and is conserved from C. elegans to human. We report a paracentric inversion (PAI) of chromosome 20p12.2p13 in an individual with AGS who also had alpha-1-antitrypsin deficiency. To our knowledge, this is the first published case of PAI involving the short arm of chromosome 20. Using FISH, fiberFISH, and molecular studies with a approximately 40 kb cosmid clone encompassing the entire 36 kb JAG1 gene, we demonstrate that the gene was disrupted by the inversion breakpoint between exons 5 and 6. An unusual association between two most common causes of chronic liver disease in childhood, AGS and alpha-1-antitrypsin deficiency, as well as their influence on the proband's abnormal phenotype are discussed.


Asunto(s)
Síndrome de Alagille/genética , Inversión Cromosómica , Cromosomas Humanos Par 20/genética , Proteínas/genética , Síndrome de Alagille/patología , Southern Blotting , Proteínas de Unión al Calcio , Preescolar , Bandeo Cromosómico , ADN/genética , Humanos , Hibridación Fluorescente in Situ , Lactante , Péptidos y Proteínas de Señalización Intercelular , Proteína Jagged-1 , Masculino , Proteínas de la Membrana , Mutación , Proteínas Serrate-Jagged
13.
Naunyn Schmiedebergs Arch Pharmacol ; 353(1): 86-93, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8750921

RESUMEN

The K+ channel openers activate ATP-sensitive K+ channels (KATP) in vascular smooth muscle and induce relaxation. In this study, the relationship between these two effects was examined in rings of rat aorta using levcromakalim and minoxidil sulfate as the openers and Ba2+ as the K+ channel blocker; K+ channel opening was assessed by determining the rate constant of 86Rb+ efflux from the preparation. Ba2+ inhibited the 86Rb+ efflux stimulated by levcromakalim in a noncompetitive manner with an IC50 value of 29 microM and a Hill-coefficient of 1.2. At concentrations >300 microM, Ba2+ increased the tension of rat aortic rings concentration-dependently. Levcromakalim relaxed contractions to Ba2+ (0.5 and 1 mM) with potencies similar to those determined against KCl (25 mM) or noradrenaline as spasmogens (EC50 values 15-40 nM). The vasorelaxant effect against Ba2+ was inhibited by the KATP channel blockers, glibenclamide and tedisamil, and abolished in depolarizing medium (55 mM KCl). At 3 mM Ba2+, levcromakalim was still able to transiently induce complete relaxation; however, within 1 h oscillations in tension developed, leading to a stable level of only 15% relaxation. A similar level of relaxation was achieved against 10 mM Ba2+ whereas the combination of 0.5 mM Ba2+ and 3 microM tedisamil blocked the relaxant effect of levcromakalim completely. With minoxidil sulfate as the KATP channel opener the results of the 86Rb+ efflux and tension experiments were similar to those obtained with levcromakalim. It is concluded that Ba2+ is more potent in inhibiting the K+ channel opening than the vasorelaxant effects of the openers. On the basis of the 86Rb+ efflux experiments it is estimated that at least 97% of the channels opened by the activators can be blocked without major effects on vasorelaxation suggesting a dissociation between the two effects. However, if the block is pushed to extremes (> or = 99.95%) the vasorelaxant effect of the openers is also abolished suggesting a link between both effects. This paradoxon remains to be solved.


Asunto(s)
Bario/farmacología , Benzopiranos/farmacología , Minoxidil/análogos & derivados , Bloqueadores de los Canales de Potasio , Potasio/metabolismo , Pirroles/farmacología , Vasodilatadores/farmacología , Animales , Aorta/efectos de los fármacos , Aorta/fisiología , Cromakalim , Técnicas In Vitro , Masculino , Minoxidil/farmacología , Canales de Potasio/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Radioisótopos de Rubidio , Vasoconstricción/efectos de los fármacos
14.
Naunyn Schmiedebergs Arch Pharmacol ; 356(3): 425-32, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9303583

RESUMEN

In rat aortic rings, P1075, an opener of ATP-dependent potassium channels (K(ATP) channels), produces relaxation and 86Rb+ efflux from preloaded tissues; the increase in 86Rb+ efflux qualitatively reflects K(ATP) channel opening. In this study we have investigated the effects of protein kinase C modulation on the 86Rb+ efflux stimulating, the vasorelaxant and the binding properties of P1075. Phorbol 12,13-dibutyrate (PDBu), a direct activator of protein kinase C, inhibited the 86Rb+ efflux produced by P1075 with an IC50 value of 20+/-2 nM. Phorbol 12-myristate 13-acetate (PMA), another stimulator of protein kinase C, was 150 times weaker in this respect whereas 4alpha-PDBu, the inactive stereoisomer of PDBu, was ineffective. Staurosporine (300 nM), an inhibitor of protein kinase C, induced a small but significant increase of P1075-induced tracer efflux and partially reversed the inhibitory effect of PDBu on P1075-stimulated tracer efflux. The vasorelaxant effect of P1075 was inhibited only to a moderate degree by PDBu at concentrations which inhibited P1075-induced 86Rb+ efflux to >90%; however, in the presence of PDBu, the relaxation kinetics of P1075 were increasingly slowed. The vasorelaxant effect of P1075 in the presence of PDBu was still sensitive to inhibition by glibenclamide (100 nM), the standard inhibitor of the K(ATP) channel openers. Specific binding of [3H]-P1075 to rat aortic rings was unaffected by PDBu and PMA even in the micromolar concentration range. The data show that stimulation of protein kinase C inhibits the K+ channel opening effect of P1075 in rat aorta and suggest that protein kinase C may exert a weak tonic inhibition on the K(ATP) channels in this vessel under quasiphysiological conditions. At concentrations of PDBu which essentially abolished P1075-induced tracer efflux, the glibenclamide-sensitive vasorelaxant effect of P1075 was slowed down but not prevented; this supports earlier suggestions that K+ channel openers are also able to relax smooth muscle cells by a mechanism independent of K(ATP) channel opening.


Asunto(s)
Adenosina Trifosfato/metabolismo , Aorta/efectos de los fármacos , Guanidinas/farmacología , Músculo Liso Vascular/efectos de los fármacos , Canales de Potasio/efectos de los fármacos , Proteína Quinasa C/antagonistas & inhibidores , Piridinas/farmacología , Animales , Aorta/fisiología , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Guanidinas/metabolismo , Técnicas In Vitro , Masculino , Contracción Muscular/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Músculo Liso Vascular/fisiología , Forbol 12,13-Dibutirato/farmacología , Unión Proteica , Proteína Quinasa C/metabolismo , Piridinas/metabolismo , Ratas , Ratas Sprague-Dawley , Radioisótopos de Rubidio , Acetato de Tetradecanoilforbol/farmacología
15.
Naunyn Schmiedebergs Arch Pharmacol ; 355(2): 141-9, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9050005

RESUMEN

The kidney is endowed with ATP-sensitive K+ channels (KATP channels) both at the vascular and at the epithelial level. In this study we have characterized the binding of the sulphonylurea glibenclamide, the most widely used blocker of KATP channels, in rat isolated glomeruli. In metabolically intact glomeruli, 3H-glibenclamide labelled two different binding components with affinities of 47 +/- 12 nM and 10 +/- 1 microM and estimated binding capacities of 1.2 +/- 0.1 and 501 +/- 11 pmol/mg protein, respectively. 3H-glibenclamide binding was inhibited differentially by other sulphonylureas (tolbutamide, glibornuride, gliquidone and glipizide) and benzoic acid analogues such as meglitinide, AZ-DF 265 and UL-DF 9. Sulphonylureas interacted with the high affinity component and, in some cases, also with the low affinity component whereas the benzoic acid derivatives inhibited exclusively low affinity glibenclamide binding. Severe metabolic stress affected both components of glibenclamide binding by shifting high affinity binding to the right and reducing the capacity of the low affinity component. Disruption of the cytoskeletal actin filaments by cytochalasin B and D mimicked the effect of metabolic stress on the high affinity component but left the low affinity component unchanged. In crude membranes, the affinity of the first component was again reduced and a major loss of the low affinity sites was observed. The data show that the two binding components of glibenclamide binding in rat isolated glomeruli have very different properties. The high affinity component is not recognized by the benzoic acid derivatives; its affinity is modulated by cell metabolism and the actin component of the cytoskeleton. The low affinity sites are, in their majority, cytosolic. The function and cellular localization of the high affinity sites are under further study.


Asunto(s)
Gliburida/metabolismo , Glomérulos Renales/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Benzoatos/farmacología , Unión Competitiva , Citoesqueleto/efectos de los fármacos , Citoesqueleto/metabolismo , Gliburida/farmacología , Técnicas In Vitro , Glomérulos Renales/citología , Glomérulos Renales/efectos de los fármacos , Masculino , Bloqueadores de los Canales de Potasio , Ratas , Ratas Sprague-Dawley , Compuestos de Sulfonilurea/farmacología
16.
Naunyn Schmiedebergs Arch Pharmacol ; 356(4): 467-74, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9349633

RESUMEN

In vascular smooth muscle, openers of ATP-dependent potassium channels (K(ATP) channels), such as P1075 (N-cyano-N'-(1,1-dimethylpropyl)-N"-3-pyridylguanidine), produce relaxation. In this study we have investigated the effects of thiol-modifying agents on the binding of P1075 and on the 86Rb+ efflux stimulating and vasorelaxant effects of the opener in rat aortic rings. The increase in 86Rb+ efflux induced by P1075 was taken as a qualitative measure of K+ channel opening. The hydrophilic SH-group-oxidizing substance, thimerosal (1 to 100 microM), abolished specific binding of [3H]-P1075 with an IC50 value of 7.6+/-1.2 microM; at 30 microM, the half time for inhibition was 38 min. Two other thioloxidizing agents, PMB (4-hydroxy-mercuribenzoic acid) and DTBNP (2,2'-dithio-bis(5-nitropyridine)), inhibited binding up to 86% and 44%, respectively. The disulphide bond reducing substance, DTT (1,4-dithiothreitol, 0.1 to 1 mM), reduced [3H]-P1075 binding by up to 20% and partially reversed the inhibitory effect of thimerosal. In 86Rb+ efflux experiments, thimerosal (3 to 100 microM) concentration-dependently increased basal efflux but inhibited P1075-stimulated tracer efflux with an IC50 value of 7+/-1 microM. The inhibitory effect occurred with a half-time of approximately 8 min and was essentially reversed by DTT. In rings precontracted with noradrenaline, thimerosal inhibited the vasorelaxant effect in a noncompetitive manner, shifting the concentration-relaxation curves to the right and reducing maximum relaxation. The data show that oxidation of thiol groups interferes with the binding of the K(ATP) channel opener, P1075; concomitantly, the 86Rb+ efflux stimulating and the vasorelaxant effects are inhibited. Reduction of disulphide bonds by DTT has only minor effects on the action of P1075. Collectively, the results suggest that intact thiol groups are essential for the functioning of the K(ATP) channel in rat aorta. The different kinetics governing the inhibition of opener binding and of opener-stimulated 86Rb+ efflux suggest that the SH-groups involved in the two processes differ in their accessibility to thimerosal and/or in their reactivity.


Asunto(s)
Guanidinas/farmacología , Músculo Liso Vascular/efectos de los fármacos , Canales de Potasio/agonistas , Piridinas/farmacología , Reactivos de Sulfhidrilo/farmacología , Vasodilatadores/farmacología , Animales , Aorta/efectos de los fármacos , Ditiotreitol/farmacología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Guanidinas/metabolismo , Hidroximercuribenzoatos/farmacología , Técnicas In Vitro , Masculino , Contracción Muscular/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Canales de Potasio/efectos de los fármacos , Unión Proteica/efectos de los fármacos , Piridinas/metabolismo , Trazadores Radiactivos , Ratas , Ratas Sprague-Dawley , Rubidio , Timerosal/farmacología , Vasodilatadores/metabolismo
17.
Naunyn Schmiedebergs Arch Pharmacol ; 355(4): 483-90, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9109365

RESUMEN

The effect of activators of protein kinase A on membrane K+ permeability and the interaction of these compounds with cromakalim, an opener of ATP-sensitive K+ channels (K(ATP) channels), were investigated. Membrane K+ permeability was assessed by measuring 86Rb+ efflux from rings of rat aorta. Forskolin, an activator of adenylate cyclase, and isobutylmethylxanthine (IBMX), a nonselective phosphodiesterase inhibitor, induced small, concentration-dependent increases in tracer efflux up to 20-40% over the basal level. The effect of forskolin was abolished by the K+ channel blocker tedisamil (1 microM) and partially inhibited by glibenclamide (1 microM), a relatively selective blocker of K(ATP) channels. Further studies were conducted in the presence of 35 mM KCI in the bath in order to increase the size of the 86Rb+ efflux stimulated by forskolin and IBMX. At high concentrations, these compounds produced a biphasic effect with a peak increase being followed by a lower plateau value. Glibenclamide inhibited the 86Rb+ efflux response to forskolin and IBMX by 50-80%. The K+ channel blockers tedisamil (1 microM), Ba2+ (1 mM) and tetraethylammonium (10 mM) also reduced the peak response to forskolin by about 50% and abolished or greatly inhibited the plateau response. In addition to the small effect on basal 86Rb+ efflux, forskolin (0.3 microM) increased cromakalim-induced 86Rb+ efflux 3.4 times. At higher concentrations, however, a concentration-dependent inhibition was observed with an IC50 value of 7.6 +/- 0.4 microM. 1,9-dideoxyforskolin, which does not increase cAMP, increased neither basal nor cromakalim-induced 86Rb+ efflux; however, it inhibited cromakalim-stimulated tracer efflux with an IC50 value of 22 +/- 2 microM. It is concluded that forskolin and IBMX, probably by increasing intracellular cAMP levels, induce a 86Rb+ efflux from rat aorta, the major part of which is glibenclamide-sensitive and may pass through K(ATP) channels. In addition, low concentrations of forskolin greatly facilitate the K(ATP) channel opening effect of cromakalim whereas high concentrations block the channel; this blocking effect of forskolin is unrelated to the cAMP elevating action.


Asunto(s)
Aorta/efectos de los fármacos , Proteínas Quinasas Dependientes de AMP Cíclico/farmacología , Gliburida/farmacología , Rubidio/metabolismo , Animales , Colforsina/farmacología , Relación Dosis-Respuesta a Droga , Masculino , Ratas , Ratas Sprague-Dawley
18.
Unfallchirurg ; 110(11): 931-8, 2007 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-17989951

RESUMEN

Depending on the type and localisation, nonunions of tibial fractures will occur in 10-40% of cases. Bone morphogenetic protein 7 (BMP-7; Osigraft), a recombinant bone growth factor, can be implanted locally as an alternative to autologous bone grafting. The objective of our study was to compare the efficiency of the two procedures. From January 1995 to December 2002, 82 patients (group 1) with delayed union of a tibial fracture received autologous bone grafting as their first procedure. To compare their results with the efficiency of BMP-7, between May 2002 and June 2005 we followed up on 26 patients (group 2) who had local implantation of BMP-7 after having had, on average, four surgical procedures. Healing was considered successful if x-rays showed bony consolidation and if no further procedure was necessary. Group 1 had no signs of consolidation in 24 cases (28%), whereas group 2 had only two (8%) such patients (p=0.025). The BMP-7 group showed a significantly higher success rate compared with patients with autologous bone grafting, despite the fact that the BMP-7 group contained more complicated cases.


Asunto(s)
Proteínas Morfogenéticas Óseas/uso terapéutico , Trasplante Óseo , Seudoartrosis/cirugía , Fracturas de la Tibia/cirugía , Adulto , Femenino , Estudios de Seguimiento , Fijación Interna de Fracturas , Curación de Fractura/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Seudoartrosis/diagnóstico por imagen , Radiografía , Reoperación , Estudios Retrospectivos , Fracturas de la Tibia/diagnóstico por imagen
19.
Hum Genet ; 87(2): 221-2, 1991 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2066112

RESUMEN

Ribophorin I and II (RPN I and RPN II), two specific glycoproteins, span the rough regions of the endoplasmic reticulum (RER) and are thought to play an important role either in translocation or in the maintenance of RER. Studies with human-mouse somatic cell hybrids have localized the gene for RPN I on human chromosome 3q, while RPN II is on chromosome 20. Using a radioactive labelled cDNA probe, we have regionally mapped the RPN II gene to human chromosome 20q12-q13.1 by in situ hybridization. This assignment predicts a location of the murine homologue, Rpn-2, to the syntenic segment on mouse chromosome 2 in close proximity to Ada, Src and Gnas.


Asunto(s)
Cromosomas Humanos Par 20 , Proteínas de la Membrana/genética , Mapeo Cromosómico , Humanos , Hibridación de Ácido Nucleico
20.
Cytogenet Cell Genet ; 57(1): 39-40, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1855391

RESUMEN

Growth hormone-releasing factor (GHRF), a hypothalamic releasing factor also named somatocrinin, influences the secretion and synthesis of growth hormone. Human GHRF is encoded by a single gene which was assigned to chromosome 20 by dot-blot analysis of DNA from dual laser sorted chromosomes. Using a radioactive cDNA probe, we localized the GHRF gene to chromosome 20p12 or near band 20p12.


Asunto(s)
Cromosomas Humanos Par 20 , Hormona Liberadora de Hormona del Crecimiento/genética , Bandeo Cromosómico , Mapeo Cromosómico , ADN/genética , Sondas de ADN , Humanos , Hibridación de Ácido Nucleico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA