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INTRODUCTION: Due to demographic changes in today's society, the number of patients with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) is increasing. Similarly, the proportion of patients with cardiovascular risk factors undergoing antiplatelet (AP) or anticoagulation (AC) therapy is growing as well. METHODS: This review discusses the current literature on various techniques used for anatomic endoscopic enucleation of the prostate (AEEP) in patients on AC/AP therapy. RESULTS: The large number of energy sources used for AEEP makes it difficult to compare them. Overall, fewer bleeding-associated complications arise in patients under AP compared to AC or bridging therapy with low molecular weight heparin. However, perioperatively both AP and AC therapy lead to a higher risk of bleeding complications compared to patients not taking anticoagulants. CONCLUSIONS: The literature shows that AEEP is possible and efficacious in patients under AC/AP therapy, with only slight differences compared to patients not taking AC/AP drugs, on a short and long-term basis. Nevertheless, the sparse data, the retrospective nature of many studies and the inclusion of prostate sizes between 50 and 110 ml only, make it difficult to come to strong conclusions.
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Anticoagulantes/uso terapéutico , Endoscopía , Inhibidores de Agregación Plaquetaria/uso terapéutico , Prostatectomía/métodos , Hiperplasia Prostática/cirugía , Humanos , MasculinoRESUMEN
In honeys, several molecules have been known for their antibacterial or wound healing properties. Corsican honeys just began to be tested for their antimicrobial activity with promising results on Pseudomonas aeruginosa. So, identification of active molecules and their mode of action was determined. Hydrogen peroxide concentrations were evaluated and, in parallel, the minimal inhibitory concentrations (MIC) values were performed with and without catalase. More, the quantity of phenolic compounds and ORAC assay were measured. Observation of antibacterial action was done using scanning electron microscopy (SEM) followed by plasmidic DNA extraction. MIC values of chestnut grove and honeydew maquis honeys vary between 7 and 8%, showing a strong antimicrobial capacity, associated with a plasmidic DNA degradation. When catalase is added, MIC values significatively increase (25%) without damaging DNA, proving the importance of H2 O2 . This hypothesis is confirmed by SEM micrographies which did not show any morphological damages but a depletion in bacterial population. Although, such low concentrations of H2 O2 (between 23 µmol l-1 and 54 µmol l-1 ) cannot explain antimicrobial activity and might be correlated with phenolic compounds concentration. Thus, Corsican honeys seem to induce DNA damage when H2 O2 and phenolic compounds act in synergy by a putative pro-oxidant effect. SIGNIFICANCE AND IMPACT OF THE STUDY: We started to determine the antibacterial efficiency of Corsican chestnut grove and honeydew maquis honeys on Pseudomonas aeruginosa. No morphological alteration of the bacterial surface was observed. Antimicrobial action seems to be related to the synergy between hydrogen peroxide and phenolic compounds. The exerted pro-oxidant activity leads to a degradation of P. aeruginosa plasmidic DNA. This is the first study that investigate the primary antibacterial mechanism of Corsican honeys.
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Antibacterianos/farmacología , Catalasa/metabolismo , Daño del ADN/efectos de los fármacos , Miel/análisis , Peróxido de Hidrógeno/farmacología , Fenol/farmacología , Pseudomonas aeruginosa/efectos de los fármacos , ADN Bacteriano/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Oxidación-Reducción/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Fenol/químicaRESUMEN
Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in ^{42}Ca were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 0_{2}^{+} has been obtained and the role of triaxiality in the Aâ¼40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time.
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Insertional Achilles tendinopathy is a frequent cause of pain and performance impairment of the ankle. It is more common in runners, but may also affect general population. Conservative treatment is the gold standard in the early phases but 10% to 30% of patients require surgery. The aim of this study is to review the current literature in order to evaluate current surgical strategies for Insertional Achilles tendinopathy and to analyze the effectiveness of the available techniques. We performed a systematic review of the literature, to identify studies reporting clinical outcome after surgical treatment for Insertional Achilles tendinopathy in any population group with at least 6 months follow-up. The quality of the articles included was evaluated by the Coleman Methodology Score and correlated with the reported outcome and year of publication. We identified 16 studies reporting on 465 surgically treated Insertional Achilles tendinopathy with a mean follow-up of 29.8 months. Average age at the time of surgery was 53 years. Two different categories of surgical treatment were distinct: debridement alone or debridement with augmentation in case of excessive tendon loss. Results were excellent or good in 89.6% of cases and fair or poor in 10.4%. Average complications rate was 18.3%, with 15.7% of minor and 2.6% of major complications with no difference in the two groups. Negative correlation was found between Coleman Methodology Score and the reported outcome and positive correlation was found between Coleman Methodology Score and year of publication. Good or excellent outcome can be expected after surgical treatment for Insertional Achilles tendinopathy whatever the adopted procedure, but there is no specific evidence regarding which surgical technique provides a better outcome or a lower rate of complications. Research with higher levels of evidence and methodology that is more rigorous are needed in order to evaluate the optimal surgical strategy for patients with IAT.
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Tendón Calcáneo/patología , Enfermedades Musculoesqueléticas/cirugía , Tendinopatía/cirugía , Humanos , Resultado del TratamientoRESUMEN
Direct anterior approach to the hip allows perfect exposure of the acetabulum and an easy proximal and medial extension that makes it eligible for isolate acetabular cup revision although it is seldom used and there are only few published studies. On 23 consecutive acetabular revision (16 cases Paprosky grade 1 or 2, 5 cases 3A, 1 case 3B and 1 case 4) at an average 28-month follow up, we did not record failures or major complications. Early complications included prolonged wound healing in 4 cases and transient femoral cutaneous nerve palsy in 2 cases, the mean postoperative Harris Hip Score was 82.2 with 82.5% of excellent and good results. Our results are consistent with those reported in the literature with similar techniques. The direct anterior approach has shown excellent results for isolated cup revision, though is probably better suited for surgeons that have some experience with the same approach for primary cases.
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Acetábulo/cirugía , Cadera/cirugía , Estudios de Seguimiento , Humanos , Periodo Posoperatorio , Estudios Retrospectivos , Resultado del Tratamiento , Cicatrización de HeridasRESUMEN
BACKGROUND: Ankle-foot orthoses (AFOs) are orthopaedic devices often prescribed to treat foot drop. For patients who are not satisfied with off-the-shelf solutions, custom AFOs personalized to the patient's lower limb anatomy are required. Dynamic AFOs provide stability while allowing for physiological ankle mobility in the stance phase of walking. RESEARCH QUESTION: Can a morphology-based dynamic custom AFO made of fiberglass-reinforced polyamide restore a quasi-normal gait pattern and improve comfort in patients with foot drop? METHODS: In this pilot study, the legs and feet of ten foot drop patients (age=64.9 ± 11.4 years; BMI=26.2 ± 2.1 kg/m2) were scanned using a Kinect-based 3D scanner. A custom AFO was designed and produced for each patient using a fiberglass-reinforced polyamide through selective laser sintering. To assess kinematics, skin markers were placed on relevant bony landmarks according to a validated protocol. Each patient was instructed to walk at a self-selected comfortable speed under three conditions: wearing the custom AFO, wearing an off-the-shelf orthosis (Codivilla spring), and without any AFO (shod condition). Muscle activation in the tibialis anterior, gastrocnemius, rectus femoris and biceps femoris muscles in both legs was recorded using wireless sEMG sensors. The comfort and of each AFO was evaluated using a Visual Analogue Scale. RESULTS: The custom AFO resulted in significant increase of stride length and walking speed compared to the shod condition. Except for the hip joint, which exhibited greater maximum flexion and reduced range of motion, the kinematic parameters of all other joints were similar to those observed in a healthy control population. Furthermore, the custom AFO received significantly higher comfort scores compared to the Codivilla spring. SIGNIFICANCE: This study has provided evidence supporting the effectiveness of custom orthotic solutions in restoring lower limb kinematics and improving the perceived comfort in foot drop patients compared to off-the-shelf solutions.
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Ortesis del Pié , Vidrio , Neuropatías Peroneas , Humanos , Persona de Mediana Edad , Anciano , Proyectos Piloto , Nylons , Articulación del Tobillo , Debilidad Muscular , Paresia , Fenómenos Biomecánicos , Marcha/fisiologíaRESUMEN
OBJECTIVE: To compare intra and early postoperative outcomes between pulsed-wave and continuous-wave Thulium Fiber Laser Enucleation of the Prostate (PW-ThuFLEP vs CW-ThuFLEP) for the treatment of benign prostatic hyperplasia. METHODS: 238 patients with lower urinary tract symptoms due to benign prostatic hyperplasia underwent PW-ThuFLEP (118 patients) vs CW-ThuFLEP (120 patients). Preoperative prostate volume, adenoma volume, prostate-specific antigen (PSA), and hemoglobin values were recorded. International Prostate Symptom Score (IPSS), maximum flow rate (Qmax), post-void residual volume, and International Index of Erectile Function-5 score (IIEF-5) were assessed. Operative time, enucleation time, enucleation efficiency, catheterization time, irrigation volume, hospital stay, hemoglobin drop, and postoperative complications were recorded. Micturition improvements and sexual outcomes were evaluated 3months after surgery. RESULTS: CW-ThuFLEP showed shorter operative time (61.5 vs 67.4 minutes, P = .04). Enucleation time (50.2 vs 53.3 minutes, P = .12), enucleation efficiency (0.8 vs 0.7 g/min, P = .38), catheterization time (2.2 vs 2.1days, P = .29), irrigation volume (32.9 vs 32.8L, P = .71), hospital stay (2.8 vs 2.6days, P = .29) and hemoglobin drop (0.38 vs 0.39 g/dL, P = .53) were comparable. No significant difference in complication rate was observed. At 3-month follow-up, the procedures did not show any significant difference in IPSS, Qmax, post-void residual volume, IIEF-5, and PSA value. CONCLUSION: PW-ThuFLEP and CW-ThuFLEP both relieve lower urinary tract symptoms equally, with high efficacy and safety. Operative time was significantly shorter with CW-ThuFLEP, but with a small difference with low clinical impact. Enucleation time, enucleation efficiency, catheterization time, irrigation volume, hospital stay, hemoglobin and PSA drop, complication rate, and sexual outcomes showed no differences.
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Terapia por Láser , Láseres de Estado Sólido , Síntomas del Sistema Urinario Inferior , Hiperplasia Prostática , Resección Transuretral de la Próstata , Masculino , Humanos , Próstata/cirugía , Hiperplasia Prostática/cirugía , Tulio/uso terapéutico , Resección Transuretral de la Próstata/métodos , Antígeno Prostático Específico , Resultado del Tratamiento , Rayos Láser , Síntomas del Sistema Urinario Inferior/cirugía , Calidad de Vida , Láseres de Estado Sólido/uso terapéuticoRESUMEN
This study was conducted to evaluate the antibacterial activity of Inula graveolens and Santolina corsica essential oils on Staphylococcus aureus and investigate their effects at the cellular level. The mode of inhibition of both essential oils against S. aureus ATCC 6538P (CIP 53.156) was assessed by determining the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The effects of time and treatment dose on cell viability were determined by time-kill and bacteriolysis assays. Marked structural changes were observed by transmission electron microscopy (TEM). A bactericidal mode of inhibition was established for both essential oils, which rapidly reduced the cell viability of S. aureus at their MIC (5 mg.ml(-1)). No lysis occurred after treatments with the MIC and eight times the MIC of each essential oil. Invaginations of the plasmic membrane with thickenings of the cell wall as well as an aggregation of the cytoplasmic contents were observed in S. aureus cells treated with the MIC of both essential oils. These results suggest that the cytoplasmic membrane and the cell wall are involved in the toxic action of Inula graveolens and Santolina corsica essential oils.
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Antibacterianos/farmacología , Asteraceae/química , Inula/química , Aceites Volátiles/farmacología , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/aislamiento & purificación , Membrana Celular/efectos de los fármacos , Membrana Celular/ultraestructura , Pared Celular/efectos de los fármacos , Pared Celular/ultraestructura , Humanos , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microscopía Electrónica de Transmisión , Aceites Volátiles/aislamiento & purificación , Staphylococcus aureus/ultraestructura , Factores de TiempoRESUMEN
OBJECTIVE: Although debated, metabolic health characterizes 10-25% of obese individuals and reduces risk of developing life-threatening co-morbidities. Adipose tissue is a recognized endocrine organ important for the maintenance of whole-body metabolic health. Adipocyte transcriptional signatures of healthy and unhealthy obesity are largely unknown. METHODS: Here, we used a small cohort of highly characterized obese individuals discordant for metabolic health, characterized their adipocytes transcriptional signatures, and cross-referenced them to mouse phenotypic and human GWAs databases. RESULTS AND CONCLUSIONS: Our study showed that glucose intolerance and insulin resistance co-operate to remodel adipocyte transcriptome. We also identified the Nuclear Export Mediator Factor (NEMF) and the Ectoderm-Neural Cortex 1 (ENC1) as novel potential targets in the management of metabolic health in human obesity.
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Adipocitos/metabolismo , Intolerancia a la Glucosa , Resistencia a la Insulina , Obesidad/metabolismo , Transcriptoma , Adulto , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Células Cultivadas , Femenino , Humanos , Masculino , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Persona de Mediana Edad , Neuropéptidos/genética , Neuropéptidos/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Transporte Nucleocitoplasmático/genética , Proteínas de Transporte Nucleocitoplasmático/metabolismo , Obesidad/genéticaRESUMEN
Inhibition of insulin receptor signaling by high glucose levels and by TNF-alpha was recently observed in different cell systems. The aim of the present study was to characterize the mechanism of TNF-alpha-induced insulin receptor inhibition and to compare the consequences of TNF-alpha- and hyperglycemia-induced insulin receptor inhibition for signal transduction downstream from the IR. TNF-alpha (0.5-10 nM) and high glucose (25 mM) showed similar rapid kinetics of inhibition (5-10 min, > 50%) of insulin receptor autophosphorylation in NIH3T3 cells overexpressing the human insulin receptor. TNF-alpha effects were completely prevented by the phosphotyrosine phosphatase (PTPase) inhibitors orthovanadate (40 microM) and phenylarsenoxide (35 microM), but they were unaffected by the protein kinase C (PKC) inhibitor H7 (0.1 mM), the phosphatidylinositol-3 kinase inhibitor wortmannin (5 microM), and the thiazolidindione troglitazone (CS045) (2 microgram/ml). In contrast, glucose effects were prevented by PKC inhibitors and CS045 but unaffected by PTPase inhibitors and wortmannin. To assess effects on downstream signaling, tyrosine phosphorylation of the following substrate proteins of the insulin receptor was determined: insulin receptor substrate-1, the coupling protein Shc, focal adhesion kinase (FAK125), and unidentified proteins of 130 kD, 60 kD. Hyperglycemia (25 mM glucose) and TNF-alpha showed analogous (> 50% inhibition) effects on tyrosine phosphorylation of insulin receptor substrate-1, Shc, p60, and p44, whereas opposite effects were observed for tyrosine phosphorylation of FAK125, which is dephosphorylated after insulin stimulation. Whereas TNF-alpha did not prevent insulin-induced dephosphorylation of FAK125, 25 mM glucose blocked this insulin effect completely. In summary, the data suggest that TNF-alpha and high glucose modulate insulin receptor-signaling through different mechanisms: (a) TNF-alpha modulates insulin receptor signals by PTPase activation, whereas glucose acts through activation of PKC. (b) Differences in modulation of the insulin receptor signaling cascade are found with TNF-alpha and high glucose: Hyperglycemia-induced insulin receptor inhibition blocks both insulin receptor-dependent tyrosine phosphorylation and dephosphorylation of insulin receptor substrate proteins. In contrast, TNF-alpha blocks only substrate phosphorylation, and it does not block insulin-induced substrate dephosphorylation. The different effects on FAK125 regulation allow the speculation that long-term cell effects related to FAK125 activity might develop in a different way in hyperglycemia- and TNF-alpha-dependent insulin resistance.
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Glucosa/farmacología , Hiperglucemia/metabolismo , Insulina/metabolismo , Receptor de Insulina/metabolismo , Transducción de Señal/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacología , Células 3T3 , Animales , Resistencia a Medicamentos , Técnicas de Transferencia de Gen , Humanos , Insulina/farmacología , Ratones , Receptor de Insulina/antagonistas & inhibidores , Receptor de Insulina/genéticaRESUMEN
This paper proposes a new protocol designed to track a large number of foot segments during the stance phase of gait with the smallest possible number of markers, with particular clinical focus on coronal plane alignment of the rear-foot, transverse and sagittal plane alignment of the metatarsal bones, and changes at the medial longitudinal arch. The shank, calcaneus, mid-foot and metatarsus were assumed to be 3D rigid bodies. The longitudinal axis of the first, second and fifth metatarsal bones and the proximal phalanx of the hallux were also tracked independently. Skin markers were mounted on bony prominences or joint lines, avoiding the course of main tendons. Trajectories of the 14 markers were collected by an eight-camera motion capture system at 100 Hz on a population of 10 young volunteers. Three-dimensional joint rotations and planar angles were calculated according to anatomically based reference frames. The marker set was well visible throughout the stance phase of gait, even in a camera configuration typical of gait analysis of the full body. The time-histories of the joint rotations and planar angles were well repeatable among subjects and consistent with clinical and biomechanical knowledge. Several dynamic measurements were originally taken, such as elevation/drop of the medial longitudinal arch and of three metatarsal bones, rear-foot to fore-foot rotation and transverse plane deformation of the metatarsus. The information obtained from this protocol, consistent with previous clinical knowledge, enhanced our understanding of the dynamics of the human foot during stance.
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Pie/fisiología , Marcha/fisiología , Movimiento/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Pie/anatomía & histología , Huesos del Pie/anatomía & histología , Huesos del Pie/fisiología , Articulaciones del Pie/fisiología , Humanos , Masculino , Modelos Biológicos , Fotogrametría , RotaciónRESUMEN
BACKGROUND: Tripping over a raised surface is considered to be the most common cause of falls in the elderly. The aim of this study was to detect alterations of the motor pattern of elderly subjects while climbing a single step ("one step negotiation") which may account for tripping and risk of falling. METHODS: We tested a sample of 32 "healthy" elderly subjects with a mean age of 72.4 years (SD 4.81; range 65-86). The control group consisted of 18 young subjects with a mean age of 26.5 years (SD 2.12; range 24-33). An experimental set-up for kinematic assessment while climbing a single step was provided. The elderly population was characterized clinically and functionally by a comprehensive geriatric assessment including information about comorbidity, disability, depression, motor, and muscular function. FINDINGS: Despite the high level of motor ability measured clinically, biomechanical analysis enabled us to demonstrate precise changes in step-climbing strategy in the elderly. A prolonged double stance phase duration, a greater anterior flexion of the trunk, a greater flexion of the hip, and a reduced dorsiflexion of the ankle were detected with respect to controls. All these factors and especially the latter could be determinants in the possible risk of tripping. INTERPRETATION: The biomechanical analysis performed on a population of healthy elderly subject has shown precise abnormalities of the trunk, hip and ankle kinematic during the motor task execution. This information can be of relevance in planning physical activity programs adapted for elderly and aimed at reducing the risk of tripping and falling.
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Envejecimiento/fisiología , Pierna/fisiología , Locomoción/fisiología , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Rango del Movimiento Articular/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos/métodos , Femenino , Humanos , Masculino , Equilibrio Postural/fisiologíaRESUMEN
Lipoxygenase from olive fruit was purified to homogeneity for the first time after differential centrifugations and by hydrophobic chromatography. The enzyme had a molecular mass of 98 kDa and exhibited a maximal activity at pH 6. Lipoxygenase had a better affinity for linoleic acid (Km=82.44 microM) than for linolenic acid (Km = 306.26 microM). It is inhibited by linoleate:oxygen oxidoreductase (LOX) inhibitors like nordihydroguaiaretic acid (NDGA) or propyl gallate. The reaction product was 13-hydroperoxy octadecadienoic acid when linoleic acid was used as substrate.
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Frutas/enzimología , Lipooxigenasa/metabolismo , Olea/enzimología , Proteínas de Plantas/metabolismo , Fraccionamiento Celular , Inhibidores Enzimáticos/farmacología , Concentración de Iones de Hidrógeno , Cinética , Ácido Linoleico/metabolismo , Lipooxigenasa/aislamiento & purificación , Masoprocol/farmacología , Proteínas de Plantas/aislamiento & purificación , Galato de Propilo/farmacología , Especificidad por Sustrato , Ácido alfa-Linolénico/metabolismoRESUMEN
Troglitazone (CS045), a compound belonging to the thiazolidine diones, is being tested as a new oral antidiabetic agent. Evidence exists from animal studies and clinical trials with non-insulin-dependent diabetes mellitus patients that Troglitazone might reduce insulin resistance. The molecular mechanism of this effect is not understood. In this study, we investigated whether Troglitazone might interfere with the mechanism of glucose-induced insulin resistance. Several studies indicate that hyperglycemia reduces the kinase activity of the insulin receptor in different cell types. This effect is paralleled by translocation of several protein kinase C (PKC) isoforms, and it can be prevented by PKC inhibitors, which suggests that glucose-induced receptor desensitization is mediated by activation of PKC. We studied the effect of hyperglycemia on the insulin receptor kinase activity and its modulation by Troglitazone in rat-1 fibroblasts that stably overexpress the human insulin receptor. Before stimulation with insulin (10(-7) M), cells were acutely exposed to hyperglycemic conditions in the absence or presence of Troglitazone (0.01-2 micrograms/ml). The insulin receptor was solubilized from a plasma membrane fraction or whole cell lysates, and proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotted against antiphosphotyrosine and anti-insulin receptor beta-subunit (CT 104) antibodies. Acute hyperglycemia (25 mM glucose) induced a significant inhibition of the insulin receptor kinase (IRK) activity within 30 min (inhibition to 30 +/- 12.5% of maximal insulin-stimulated beta-subunit phosphorylation, n = 9, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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Cromanos/farmacología , Fibroblastos/metabolismo , Glucosa/farmacología , Hipoglucemiantes/farmacología , Resistencia a la Insulina , Receptor de Insulina/antagonistas & inhibidores , Receptor de Insulina/efectos de los fármacos , Tiazoles/farmacología , Tiazolidinedionas , 1-(5-Isoquinolinesulfonil)-2-Metilpiperazina , Animales , Línea Celular , Humanos , Immunoblotting , Técnicas de Inmunoadsorción , Isoquinolinas/farmacología , Cinética , Fosforilación , Fosfotirosina , Piperazinas/farmacología , Ratas , Receptor de Insulina/metabolismo , Troglitazona , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMEN
Insulin resistance of the skeletal muscle plays a key role in the development of the metabolic endocrine syndrome and its further progression to type II diabetes. Impaired signaling from the insulin receptor to the glucose transport system and to glycogen synthase is thought to be the cause of skeletal muscle insulin resistance. An incomplete activation of the insulin receptor tyrosine kinase, which is found in type II diabetes, appears to contribute to the pathogenesis of the signaling defect. Available data suggest that the impaired tyrosine kinase function of the insulin receptor is not due to an inherited defect but rather is caused by a modulation of insulin receptor function. We used rat-1 fibroblasts and NIH-3T3 cells stably overexpressing human insulin receptor and 293 cells transiently overexpressing human insulin receptor to characterize conditions modulating the signaling function of the insulin receptor kinase. Using these cell models, we could demonstrate that activation of different protein kinase C (PKC) isoforms by high glucose levels or phorbol esters causes a rapid inhibition of the receptor tyrosine kinase activity. This effect is most likely mediated through serine phosphorylation of the receptor beta-subunit. It can be prevented by PKC inhibitors and the new oral antidiabetic agent thiazolidindione. The data suggest that PKC might be an important negative regulator of insulin receptor function. Because we have recently shown that bradykinin activates different isoforms of PKC in these cell types, an inhibitory cross talk between the bradykinin receptor and the insulin receptor through PKC activation seemed possible. However, we were unable to observe an insulin receptor tyrosine kinase inhibition through bradykinin, suggesting that different isoforms of PKC are activated by hyperglycemia and bradykinin. On the other hand, a modulation of bradykinin signals by insulin could be demonstrated in these cells. Bradykinin-induced tyrosine phosphorylation of proteins of approximately 130 and 70 kDa was inhibited by insulin treatment of rat-1 fibroblasts. These data suggest that signals from the insulin receptor modify signaling from the bradykinin receptor to tyrosine phosphorylation of different cellular proteins.
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Bradiquinina/fisiología , Insulina/fisiología , Receptor de Insulina/fisiología , Factor de Necrosis Tumoral alfa/fisiología , Animales , Compartimento Celular , Humanos , Fosfotirosina/metabolismo , Proteína Quinasa C/metabolismo , Proteínas Serina-Treonina Quinasas/fisiología , Ratas , Transducción de SeñalRESUMEN
GLUT4 translocation and activation of glucose uptake in skeletal muscle can be induced by both physiological (i.e., insulin, nerve stimulation, or exercise) and pharmacological (i.e., phorbol ester) means. Recently, we demonstrated that high glucose levels may mimic the effects of phorbol esters on protein kinase C (PKC) and insulin receptor function (J Biol Chem 269:3381-3386, 1994). In this study, we tested whether the previously described effects of phorbol esters on translocation of GLUT4 in myotubes in culture and also in rat skeletal muscle might be mimicked by glucose. We found that stimulation of C2C12 myotubes with both insulin (10(-7) mol/l, 5 min) and glucose (25 mmol/l, 10 min) induces a comparable increase of the GLUT4 content in the plasma membrane. To test whether this effect occurs in intact rat skeletal muscle as well, two different model systems were used. As an in vitro model, isolated rat hindlimbs were perfused for 80 min with medium containing 6 mmol/l glucose +/- insulin (1.6 x 10(-9) mmol/l, 40 min) or 25 mmol/l glucose. As an in vivo model, acute hyperglycemia (> 11 mmol/l glucose, 20 min) was induced in Wistar rats by intraperitoneal injection of glucose under simultaneous suppression of the endogenous insulin release by injection of somatostatin. In both models, subcellular fractions were prepared from hindlimb skeletal muscle, and plasma membranes were characterized by the enrichment of the marker enzyme alpha 1 Na(+)-K(+)-ATPase.(ABSTRACT TRUNCATED AT 250 WORDS)
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Hiperglucemia/metabolismo , Proteínas de Transporte de Monosacáridos/metabolismo , Proteínas Musculares , Músculo Esquelético/metabolismo , Animales , Transporte Biológico , Membrana Celular/metabolismo , Glucosa/metabolismo , Transportador de Glucosa de Tipo 4 , Proteína Quinasa C/metabolismo , Ratas , Ratas WistarRESUMEN
INTRODUCTION: We sought to evaluate the behavior of C2 values and their correlation with acute rejection episodes and cyclosporine (CyA) side effects in heart transplant patients whose immunosuppressive therapy, was monitored with C0 trough levels. METHODS: Sixty stable patients who had received heart transplants from 3 months to 60 months prior were randomly observed from September 2001 to June 2004. Four area under the concentration-time curves (AUC) were performed on each patient, a total of 240 AUC curves. RESULTS: Regarding the variability of CyA absorption, two groups of patients were distinguished: group A, "constant absorbers," namely, low variability (<15%) of CyA absorption; group B, "inconstant absorbers" patients with higher (>15%) variability of absorption. Group B patients showed more acute rejection episodes (41%) than group A (19%). CyA side effects were more serious in patients with higher variability of absorption: systemic hypertension, neurological disorders, hyperlipidemia, and gum hyperplasia; Group B patients who developed CyA side effects showed higher maximum and mean C2 levels (P < .05) than group A patients. No differences were found with regard to renal dysfunction between the two groups: all patients showed a mean increase of serum creatinine by at least 50% compared to the baseline value. CONCLUSION: Higher C2 levels were not sufficient to predict acute rejection compared to lower but constants, C2 levels. Patients with inconstant absorption were more often overexposed to CyA than underexposed, developing more side effects than patients with lower variability of absorption. Monitoring CyA therapy with C0 and C2 may prevent over- or underexposure to the drug.
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Ciclosporina/farmacocinética , Trasplante de Corazón/inmunología , Administración Oral , Área Bajo la Curva , Ciclosporina/sangre , Ciclosporina/uso terapéutico , Diabetes Mellitus Tipo 1/sangre , Monitoreo de Drogas/métodos , Femenino , Estudios de Seguimiento , Humanos , Inmunosupresores/sangre , Inmunosupresores/farmacocinética , Inmunosupresores/uso terapéutico , Absorción Intestinal , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
BACKGROUND: Severe ankle arthritis is a life-limiting condition which often requires surgery. Ankle arthroplasty via artificial or "biological" reconstruction is a viable option in those patients who are not comfortable with arthrodesis. More functional studies are needed to compare the performance and outcomes of the two function-preserving arthroplasties. METHODS: In this study two groups of 10 patients affected by severe ankle arthritis were treated either with a 3-component ankle prosthesis or with bipolar fresh osteochondral allograft transplantation. Patients were evaluated pre-operatively and at 5-year follow-up. The American Orthopaedic Foot and Ankle Society score was used for clinical evaluation, and gait analysis for functional assessment. Activation pattern of lower limb muscles was obtained by surface electromyography (EMG). In each group, kinematic, kinetic, and EMG data were compared between pre-op and follow-up assessments, and also versus corresponding data from a 20 healthy subject control group. The median clinical score significantly increased between pre-op and follow-up from 53 to 74.5 in the transplantation and from 28.5 to 80 in the prosthesis group. Spatio-temporal parameters showed a statistically significant improvement in cadence and cycle time. Improvement of gait speed was also observed only in the prosthesis group. EMG patterns at follow-up were strongly correlated with the corresponding control data for both groups. Although no significant amelioration in the joints' range of motion was detected in either surgical procedure, preservation of the functional conditions at medium-term, along with significant improvement of the clinical score, may be considered a positive outcome for both techniques.
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Artritis/cirugía , Artroplastia de Reemplazo de Tobillo/métodos , Trasplante Óseo/métodos , Cartílago/trasplante , Adulto , Anciano , Aloinjertos , Articulación del Tobillo/fisiopatología , Artritis/fisiopatología , Fenómenos Biomecánicos , Electromiografía , Femenino , Estudios de Seguimiento , Marcha/fisiología , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Músculo Esquelético/fisiología , Dimensión del Dolor , Rango del Movimiento Articular/fisiología , Resultado del Tratamiento , Adulto JovenRESUMEN
Leptin regulates energy homeostasis via binding to receptors in the hypothalamus and peripheral tissues. We have investigated the signaling pathways and effects of leptin on glucose transport in C2C12 muscle cells. Long and short forms of leptin receptor are expressed in differentiated C2C12 myotubes. Leptin enhanced the DNA-binding activity of the transcription factor STAT3 and extracellular signal-regulated kinase 2 (ERK2) activity was stimulated by leptin after 15 min. Leptin increased glucose uptake and GLUT4 recruitment to the cell surface after 30 min, whereas no changes in GLUT1 was observed. PD98059, an ERK2 kinase-1 inhibitor, and wortmannin, an inhibitor of phosphatidylinositol 3-kinase blocked the leptin-induced increase in glucose uptake and GLUT4 recruitment to the cell surface. In contrast, insulin-stimulated glucose transport and GLUT4 translocation was inhibited by wortmannin, but not by PD98059. Our results suggest that leptin may regulate glucose metabolism by acting directly on skeletal muscle and that the signaling pathways involved may be different from that activated by insulin.
Asunto(s)
Glucosa/metabolismo , Leptina/metabolismo , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteínas Musculares , Músculo Esquelético/química , Receptores de Superficie Celular , Androstadienos/farmacología , Animales , Transporte Biológico/efectos de los fármacos , Proteínas Portadoras/genética , Línea Celular , Proteínas de Unión al ADN/efectos de los fármacos , Proteínas de Unión al ADN/metabolismo , Activación Enzimática/efectos de los fármacos , Flavonoides/farmacología , Transportador de Glucosa de Tipo 4 , Humanos , Leptina/farmacología , Ratones , Proteínas de Transporte de Monosacáridos/efectos de los fármacos , Músculo Esquelético/citología , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , ARN Mensajero/biosíntesis , Receptores de Leptina , Factor de Transcripción STAT3 , Transducción de Señal , Transactivadores/efectos de los fármacos , Transactivadores/metabolismo , WortmaninaRESUMEN
Human gastric lipase (HGL) is an enzyme secreted by the stomach, which is stable and active despite the highly acidic environment. It has been clearly established that this enzyme is responsible for 30% of the fat digestion processes occurring in human. This globular protein belongs to the alpha/beta hydrolase fold family and its catalytic serine is deeply buried under a domain called the extrusion domain, which is composed of a 'cap' domain and a segment consisting of 58 residues, which can be defined as a lid. The exact roles played by the cap and the lid domains during the catalytic step have not yet been elucidated. We have recently solved the crystal structure of the open form of the dog gastric lipase in complex with a covalent inhibitor. The detergent molecule and the inhibitor were mimicking a triglyceride substrate that would interact with residues belonging to both the cap and the lid domains. In this study, we have investigated the role of the cap and the lid domains, using site-directed mutagenesis procedures. We have produced truncated mutants lacking the lid and the cap. After expressing these mutants and purifying them, their activity was found to have decreased drastically in comparison with the wild type HGL. The lid and the cap domains play an important role in the catalytic reaction mechanism. Based on these results and the structural data (open form of DGL), we have pointed out the cap and the lid residues involved in the binding with the lipidic substrate.