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1.
Biotechnol J ; 19(2): e2300384, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38403465

RESUMEN

A new biomanufacturing platform combining intracellular metabolic engineering of the oleaginous yeast Yarrowia lipolytica and extracellular bioreaction engineering provides efficient bioconversion of plant oils/animal fats into high-value products. However, predicting the hydrodynamics and mass transfer parameters is difficult due to the high agitation and sparging required to create dispersed oil droplets in an aqueous medium for efficient yeast fermentation. In the current study, commercial computational fluid dynamic (CFD) solver Ansys CFX coupled with the MUSIG model first predicts two-phase system (oil/water and air/water) mixing dynamics and their particle size distributions. Then, a three-phase model (oil, air, and water) utilizing dispersed air bubbles and a polydispersed oil phase was implemented to explore fermenter mixing, gas dispersion efficiency, and volumetric mass transfer coefficient estimations (kL a). The study analyzed the effect of the impeller type, agitation speed, and power input on the tank's flow field and revealed that upward-pumping pitched blade impellers (PBI) in the top two positions (compared to Rushton-type) provided advantageous oil phase homogeneity and similar estimated kL a values with reduced power. These results show good agreement with the experimental mixing and kL a data.


Asunto(s)
Reactores Biológicos , Hidrodinámica , Animales , Fermentación
2.
Int J Pharm ; 628: 122273, 2022 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-36228881

RESUMEN

Pharmaceutical toxicity evaluations often use in vitro systems involving primary cells, cell lines or red blood cells (RBCs). Cell-based analyses ('bioassays') can be cumbersome and typically rely on hard-to-standardize biological materials. Amphotericin B (AmB) toxicity evaluations are primarily based on potassium release from RBCs and share these limitations. This study evaluates the potential substitution of two physicochemical AmB toxicity approaches for the bioassay: Ultraviolet-visible spectroscopy (UV-vis) and in vitro drug release kinetics. UV-vis spectral analyses indicated that liposomal AmB's (L-AmB) main peak position (λmax) and peak ratio (OD346/OD322) are potential toxicity surrogates. Similarly, two first-order release parameters derived from USP-4 in vitro drug release analyses also provided linear relationships with toxicity. These were the initial, overall drug release rate and the ratio of loose to tight AmB pools. Positive slopes and high correlation coefficients (R2 > 0.9) characterized all interrelations between physicochemical parameters and toxicity. These tests converted the manufacturing variables' nonlinear (i.e., curvilinear) relationships with in vitro toxicity to linear responses. Three different toxicity attenuation approaches (2 manufacturing, 1 formulation), covering formulation composition and process aspects, support this approach's universality. These data suggest that one or more spectral and kinetic physicochemical tests can be surrogates for L-AmB in vitro toxicity testing.


Asunto(s)
Anfotericina B , Antifúngicos , Anfotericina B/toxicidad , Anfotericina B/química , Antifúngicos/toxicidad , Antifúngicos/química , Liposomas , Liberación de Fármacos
3.
Asian J Pharm Sci ; 17(4): 544-556, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36105314

RESUMEN

Amphotericin B (AmB) is an amphiphilic drug commonly formulated in liposomes and administered intravenously to treat systemic fungal infections. Recent studies on the liposomal drug product have shed light on the AmB aggregation status in the bilayer, which heat treatment (curing) modifies. Although toxicity was found related to aggregation status - loose aggregates significantly more toxic than tight aggregates - the precise mechanism linking aggregation and toxicity was not well understood. This study directly measured drug release rate from various AmB liposomal preparations made with modified curing protocols to evaluate correlations among drug aggregation state, drug release, and in vitro toxicity. UV-Vis spectroscopy of these products detected unique curing-induced changes in the UV spectral features: a ∼25 nm blue-shift of the main absorption peak (λmax) in aqueous buffer and a decrease in the OD346/OD322 ratio upon thermal curing, reflecting tighter aggregation. In vitro release testing (IVRT) data showed, by applying and fitting first-order release kinetic models for one or two pools, that curing impacts two significant changes: a 3-5-fold drop in the overall drug release rate and a ten-fold decrease in the ratio between the loosely aggregated and the tightly aggregated, more thermodynamically stable drug pool. The kinetic data thus corroborated the trend independently deduced from the UV-Vis spectral data. The in vitro toxicity assay indicated a decreased toxicity with curing, as shown by the significantly increased concentration, causing half-maximal potassium release (TC50). The data suggest that the release of AmB requires dissociation of the tight complexes within the bilayer and that the reduced toxicity relates to this slower rate of dissociation. This study demonstrates the relationship between AmB aggregation status within the lipid bilayer and drug release (directly measured rate constants), providing a mechanistic link between aggregation status and in vitro toxicity in the liposomal formulations.

4.
AAPS PharmSciTech ; 23(1): 14, 2021 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-34888739

RESUMEN

This work presents a compact model for the equipment capability limit of a common configuration of pharmaceutical lyophilizers, a product chamber separated from the condenser by a duct and isolation valve, at a wide range of design parameters. The equipment capability limit is one of the most important characteristics determining the lyophilization design space for a particular product, container, and equipment combination. Experimental measurements of equipment capability are time-consuming and expensive, especially at the production scale. Numerical modeling using computational fluid dynamics may reduce the number of experiments and provide insights into the physics of the process with high resolution. The computational fluid dynamics (CFD) modeling has been used in this work to develop a compact model for lyophilizer equipment capability. This eliminates the need for end users to create a full CFD model of the equipment and process. Full CFD and compact model simulations for laboratory and pilot-scale lyophilizers have been compared with tunable diode laser absorption spectroscopy measurements of the water vapor mass flow during ice slab tests. The compact model results average deviation from the experimental data is within 10%, whereas the full CFD simulations are within 5%. The compact model is based on several key parameters which are the main characteristics of a lyophilizer affecting the equipment capability curve. These parameters are discussed, and their effect on the modeling results is shown.


Asunto(s)
Hidrodinámica , Tecnología Farmacéutica , Diseño de Equipo , Liofilización , Análisis Espectral
5.
AAPS PharmSciTech ; 22(8): 274, 2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34773199

RESUMEN

Freeze-drying is a deceptively complex operation requiring sophisticated design of a robust and efficient process that includes understanding and planning for heterogeneity across the batch and shifts in parameters due to vial or lyophilizer changes. A software tool has been designed to assist in process development and scale-up based on a model that includes consideration of the process heterogeneity. Two drug formulations were used to test the ability of the new tool to develop a freeze-drying cycle and correctly predict product temperatures and drying times. Model inputs were determined experimentally, and the primary drying heterogeneous freeze-drying model was used to design drying cycles that provided data to verify the accuracy of model-predicted product temperature and primary drying time. When model inputs were accurate, model-predicted primary drying times were within 0.1 to 15.9% of experimentally measured values, and product temperature accuracy was between 0.2 and 1.2°C for three vial locations, center, inner edge, and outer edge. However, for some drying cycles, differences in vial heat transfer coefficients due to changes in shelf and product temperature as well as altered product resistance due to product temperature-dependent microcollapse increased inaccuracy (up to 28.6% difference in primary drying time and 5.1°C difference in product temperature). This highlights the need for careful determination of experimental conditions used to calculate model inputs. In future efforts, full characterization of location- and shelf temperature-dependentKv as well as location- and product temperature-dependentRp will enhance the accuracy of the predictions by the model within the user-friendly software.


Asunto(s)
Desecación , Laboratorios , Liofilización , Programas Informáticos , Tecnología Farmacéutica , Temperatura
6.
JACC Heart Fail ; 9(4): 293-300, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33714749

RESUMEN

OBJECTIVES: The authors estimated changes of stressed blood volume (SBV) induced by splanchnic nerve block (SNB) in patients with either decompensated or ambulatory heart failure with reduced ejection fraction (HFrEF). BACKGROUND: The splanchnic vascular capacity is a major determinant of the SBV, which in turn determines cardiac filling pressures and may be modifiable through SNB. METHODS: We analyzed data from 2 prospective, single-arm clinical studies in decompensated HFrEF (splanchnic HF-1; resting hemodynamics) and ambulatory heart failure (splanchnic HF-2; exercise hemodynamics). Patients underwent invasive hemodynamics and short-term SNB with local anesthetics. SBV was simulated using heart rate, cardiac output, central venous pressure, pulmonary capillary wedge pressure, systolic and diastolic systemic arterial and pulmonary artery pressures, and left ventricular ejection fraction. SBV is presented as ml/70 kg body weight. RESULTS: Mean left ventricular ejection fraction was 21 ± 11%. In patients with decompensated HFrEF (n = 11), the mean estimated SBV was 3,073 ± 251 ml/70 kg. At 30 min post-SNB, the estimated SBV decreased by 10% to 2,754 ± 386 ml/70 kg (p = 0.003). In ambulatory HFrEF (n = 14) patients, the mean estimated SBV was 2,664 ± 488 ml/70 kg and increased to 3,243 ± 444 ml/70 kg (p < 0.001) at peak exercise. The resting estimated SBV was lower in ambulatory patients with HFrEF than in decompensated HFrEF (p = 0.019). In ambulatory patients with HFrEF, post-SNB, the resting estimated SBV decreased by 532 ± 264 ml/70 kg (p < 0.001). Post-SNB, with exercise, there was no decrease of estimated SBV out of proportion to baseline effects (p = 0.661). CONCLUSIONS: The estimated SBV is higher in decompensated than in ambulatory heart failure. SNB reduced the estimated SBV in decompensated and ambulatory heart failure. The reduction in estimated SBV was maintained throughout exercise. (Splanchnic Nerve Anesthesia in Heart Failure, NCT02669407; Abdominal Nerve Blockade in Chronic Heart Failure, NCT03453151).


Asunto(s)
Insuficiencia Cardíaca , Volumen Sanguíneo , Humanos , Estudios Prospectivos , Nervios Esplácnicos , Volumen Sistólico , Función Ventricular Izquierda
7.
Pain ; 162(5): 1528-1538, 2021 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-33259458

RESUMEN

ABSTRACT: Traditional classification and prognostic approaches for chronic pain conditions focus primarily on anatomically based clinical characteristics not based on underlying biopsychosocial factors contributing to perception of clinical pain and future pain trajectories. Using a supervised clustering approach in a cohort of temporomandibular disorder cases and controls from the Orofacial Pain: Prospective Evaluation and Risk Assessment study, we recently developed and validated a rapid algorithm (ROPA) to pragmatically classify chronic pain patients into 3 groups that differed in clinical pain report, biopsychosocial profiles, functional limitations, and comorbid conditions. The present aim was to examine the generalizability of this clustering procedure in 2 additional cohorts: a cohort of patients with chronic overlapping pain conditions (Complex Persistent Pain Conditions study) and a real-world clinical population of patients seeking treatment at duke innovative pain therapies. In each cohort, we applied a ROPA for cluster prediction, which requires only 4 input variables: pressure pain threshold and anxiety, depression, and somatization scales. In both complex persistent pain condition and duke innovative pain therapies, we distinguished 3 clusters, including one with more severe clinical characteristics and psychological distress. We observed strong concordance with observed cluster solutions, indicating the ROPA method allows for reliable subtyping of clinical populations with minimal patient burden. The ROPA clustering algorithm represents a rapid and valid stratification tool independent of anatomic diagnosis. ROPA holds promise in classifying patients based on pathophysiological mechanisms rather than structural or anatomical diagnoses. As such, this method of classifying patients will facilitate personalized pain medicine for patients with chronic pain.


Asunto(s)
Dolor Crónico , Trastornos de Ansiedad , Dolor Crónico/diagnóstico , Análisis por Conglomerados , Dolor Facial , Humanos , Estudios Prospectivos
8.
Curr Hypertens Rep ; 22(12): 100, 2020 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-33097982

RESUMEN

PURPOSE OF REVIEW: To highlight the indications, procedural considerations, and data supporting the use of stellate ganglion blockade (SGB) for management of refractory ventricular arrhythmias. RECENT FINDINGS: In patients with refractory ventricular arrhythmias, unilateral or bilateral SGB can reduce arrhythmia burden and defibrillation events for 24-72 h, allowing time for use of other therapies like catheter ablation, surgical sympathectomy, or heart transplantation. The efficacy of SGB appears to be consistent despite the type (monomorphic vs polymorphic) or etiology (ischemic vs non-ischemic cardiomyopathy) of the ventricular arrhythmia. Ultrasound-guided SGB is safe with low risk for complications, even when performed on anticoagulation. SGB is effective and safe and could be considered for patients with refractory ventricular arrhythmias.


Asunto(s)
Bloqueo Nervioso Autónomo , Hipertensión , Taquicardia Ventricular , Arritmias Cardíacas , Humanos , Ganglio Estrellado , Taquicardia Ventricular/terapia
9.
JACC Heart Fail ; 8(9): 742-752, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32535123

RESUMEN

OBJECTIVES: We hypothesized that splanchnic nerve blockade (SNB) would attenuate increased exercise-induced cardiac filling pressures in patients with chronic HF. BACKGROUND: Chronic heart failure (HF) is characterized by limited exercise capacity driven in part by an excessive elevation of cardiac filling pressures. METHODS: This is a prospective, open-label, single-arm interventional study in chronic HF patients. Eligible patients had a wedge pressure ≥15 mm Hg at rest or ≥25 mm Hg with exercise on baseline right heart catheterization. Patients underwent cardiopulmonary exercise testing with invasive hemodynamic assessment, followed by percutaneous SNB with ropivacaine. RESULTS: Nineteen patients were enrolled, 15 of whom underwent SNB. The average age was 58 ± 13 years, 7 (47%) patients were women and 6 (40%) were black. Left ventricular ejection fraction was ≤35% in 14 (93%) patients. No procedural complications were encountered. SNB reduced mean pulmonary arterial pressure at peak exercise from 54.1 ± 14.4 (pre-SNB) to 45.8 ± 17.7 mm Hg (p < 0.001) (post-SNB). Similarly, SNB reduced exercise-induced wedge pressure from 34.8 ± 10.0 (pre-SNB) to 25.1 ± 10.7 mm Hg (p < 0.001) (post-SNB). The cardiac index changed with peak exercise from 3.4 ± 1.2 (pre-SNB) to 3.8 ± 1.1 l/min/m2 (p = 0.011) (post-SNB). After SNB, patients exercised for approximately the same duration at a greater workload (33 ± 24 W vs. 50 ± 30 W; p = 0.019) and peak oxygen consumption VO2 (9.1 ± 2.5 vs. 9.8 ± 2.7 ml/kg/min; p = 0.053). CONCLUSIONS: SNB reduced resting and exercise-induced pulmonary arterial and wedge pressure with favorable effects on cardiac output and exercise capacity. Continued efforts to investigate short- and long-term effects of SNB in chronic HF are warranted. Clinical Trials Registration (Abdominal Nerve Blockade in Chronic Heart Failure; NCT03453151).


Asunto(s)
Insuficiencia Cardíaca , Nervios Esplácnicos , Anciano , Prueba de Esfuerzo , Tolerancia al Ejercicio , Femenino , Insuficiencia Cardíaca/terapia , Hemodinámica , Humanos , Persona de Mediana Edad , Consumo de Oxígeno , Estudios Prospectivos , Volumen Sistólico , Función Ventricular Izquierda
10.
JACC Clin Electrophysiol ; 6(5): 562-571, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32439042

RESUMEN

OBJECTIVES: This study sought to describe our institutional experience with establishing a neurocardiology service in an attempt to provide autonomic modulation as a treatment for ventricular arrhythmias (VAs). BACKGROUND: Treatment-refractory VAs are commonly driven and exacerbated by heightened sympathetic tone. METHODS: Among patients referred to the neurocardiology service (August 2016 to December 2018), we performed ultrasound-based, bilateral, temporary stellate ganglion blockade (SGB) in 20 consecutive patients. We analyzed outcomes of interest including sustained VA or VA requiring defibrillation in the 24 and 48 h before and 24 and 48 h after SGB. RESULTS: The majority of patients were men (n = 19, 95%), with a mean age of 58 ± 14 years. At the time of SGB, 10 (50%) were on inotropic support and 9 (45%) were on mechanical circulatory support. Besides 1 case of hoarseness, there were no apparent procedural complications. SGB was associated with a reduction in the number of VA episodes from the 24 h before (median 5.5 [interquartile range (IQR): 2.0 to 15.8]) to 24 h after SGB (median 0 [IQR: 0 to 3.8]) (p < 0.001). The number of defibrillation events decreased from 2.5 (IQR: 0 to 10.3) to 0 (IQR: 0 to 2.5) (p = 0.002). Similar findings were observed over the 48-h period before and after the SGB. Overall, 9 of 20 (45%) patients had a complete response with no recurrence of ventricular tachycardia (VT) or ventricular fibrillation (VF) for 48 h after SGB. Four (20%) patients had no recurrent VT or VF following SGB through discharge. Similar response rates were observed in those with ischemic (median 6 [IQR: 1.8 to 18.8] to 0.5 [IQR: 0 to 5.3] events; p = 0.031) and nonischemic (median 3.5 [IQR: 1.8 to 6.8] to 0 [IQR: 0 to 1.3] events; p = 0.012) cardiomyopathy. CONCLUSIONS: Minimally invasive, ultrasound-guided bilateral SGB appears safe and provides substantial reduction in VA burden with approximately 1 in 2 patients exhibiting complete suppression of VT or VF for 48 h.


Asunto(s)
Bloqueo Nervioso Autónomo , Taquicardia Ventricular , Adulto , Anciano , Arritmias Cardíacas/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ganglio Estrellado , Taquicardia Ventricular/terapia , Fibrilación Ventricular/terapia
11.
Pain Res Manag ; 2020: 3873098, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32148599

RESUMEN

Knee osteoarthritis is a common painful degenerative condition affecting the aging Canadian population. In addition to pain and disability, osteoarthritis is associated with depression, comorbid conditions such as diabetes, and increased caregiver burden. It is predicted to cost the Canadian healthcare system $7.6 billion dollars by 2031. Despite its high cost and prevalence, controversy persists in the medical community regarding optimal therapies to treat knee osteoarthritis. A variety of medications like nonsteroidal anti-inflammatories and opioids can cause severe side effects with limited benefits. Total knee arthroplasty, although a definitive management, comes with risk such as postoperative infections, revisions, and chronic pain. Newer injectable therapies are gaining attention as alternatives to medications because of a safer side effect profile and are much less invasive than a joint replacement. Platelet-rich plasma is beginning to replace the more common injectable therapies of intra-articular corticosteroids and hyaluronic acid, but larger trials are needed to confirm this effect. Small studies have examined prolotherapy and stem cell therapy and demonstrate some benefits. Trials involving genicular nerve block procedures have been successful. As treatments evolve, injectable therapies may offer a safe and effective pathway for patients suffering from knee osteoarthritis.


Asunto(s)
Inyecciones Intraarticulares , Osteoartritis de la Rodilla/terapia , Antiinflamatorios no Esteroideos/uso terapéutico , Canadá , Humanos , Ácido Hialurónico/uso terapéutico , Plasma Rico en Plaquetas , Proloterapia/métodos , Trasplante de Células Madre/métodos
15.
J Cardiovasc Electrophysiol ; 28(12): 1460-1467, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28833780

RESUMEN

INTRODUCTION: Treatment refractory ventricular arrhythmias (VAs) are often driven and exacerbated by heightened sympathetic tone. We aim to conduct a systematic review and meta-analysis of published studies of a temporary percutaneous stellate ganglion block (SGB) on VA burden and defibrillation episodes in patients with treatment refractory VAs. METHODS: Relevant studies from January 1960 through May 2017 were identified in PubMed and Google Scholar. We performed a patient-level analysis using Student's t-test to compare outcomes before and after SGB. RESULTS: We identified 22 unique case series with a total of 35 patients. Patients were 57 ± 17 years old and 69% were males with a high burden of VA. A unilateral (left)-sided SGB was used in 85.7% (30 of 35) of cases and the remaining were bilateral SGB. The use of a unilateral or bilateral SGB resulted in a significant reduction of VA episodes (24-hours pre: mean 16.5 [CI 9.7-23.1] events vs. post: mean 1.4 [CI 0.85-2.01] events; P = 0.0002) and need for defibrillation (24-hours pre: mean 14.2 [CI 6.8-21.6] vs. post: mean 0.6 [CI 0.3-0.9]; P = 0.0026). Furthermore, SGB was significantly associated with a reduction of VA burden regardless of etiology of cardiomyopathy, type of ventricular rhythm, and degree of contractile dysfunction. SGB was followed by surgical sympathectomy in 21% of cases. CONCLUSIONS: Early experience suggests that SGB is associated with an acute reduction in the VA burden and offers potential promise for a broader use in high-risk populations. Randomized controlled studies are needed to confirm the safety and efficacy of this therapy.


Asunto(s)
Bloqueo Nervioso Autónomo/métodos , Ganglio Estrellado/fisiopatología , Ganglio Estrellado/cirugía , Fibrilación Ventricular/fisiopatología , Fibrilación Ventricular/cirugía , Humanos , Estudios Observacionales como Asunto/métodos , Estudios Retrospectivos , Resultado del Tratamiento
16.
J Cardiovasc Electrophysiol ; 28(4): 446-449, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28019045

RESUMEN

Ventricular tachycardia (VT), ventricular fibrillation (VF), and electrical storm are commonly encountered emergency conditions in cardiac and surgical intensive care units. In most cases, recurrent ventricular arrhythmias or electrical storm are associated with a heightened sympathetic tone. These arrhythmias can be difficult to treat and may be refractory to beta-blockade, antiarrhythmic therapy, sedation, and mechanical hemodynamic support. While monomorphic ventricular tachycardia and PVC-triggered polymorphic ventricular tachycardia may sometimes be amenable to successful ablation, some patients may be too critically ill to make such an approach feasible. We present 2 cases of minimally invasive stellate ganglion blocks for the treatment of electrical storm in patients with advanced heart failure on mechanical life support. These cases are part of a collaborative initiative at our institution to use percutaneous stellate ganglion block as an adjunctive intervention to achieve control of life-threatening ventricular arrhythmias.


Asunto(s)
Anestésicos Locales/administración & dosificación , Bloqueo Nervioso Autónomo/métodos , Bupivacaína/administración & dosificación , Insuficiencia Cardíaca/terapia , Corazón/inervación , Lidocaína/administración & dosificación , Ganglio Estrellado/efectos de los fármacos , Taquicardia Ventricular/terapia , Electrocardiografía , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Humanos , Cuidados para Prolongación de la Vida , Masculino , Persona de Mediana Edad , Ganglio Estrellado/fisiopatología , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatología , Resultado del Tratamiento , Ultrasonografía Intervencional
17.
Pain Physician ; 19(3): E499-504, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27008308

RESUMEN

BACKGROUND: Intrathecal catheter placement has long-term therapeutic benefits in the management of chronic, intractable pain. Despite the diverse clinical applicability and rising prevalence of implantable drug delivery systems in pain medicine, the spectrum of complications associated with intrathecal catheterization remains largely understudied and underreported in the literature. OBJECTIVE: To report a case of thoracic nerve root entrapment resulting from intrathecal catheter migration. STUDY DESIGN: Case report. SETTING: Inpatient hospital service. RESULTS/ CASE REPORT: A 60-year-old man status post implanted intrathecal (IT) catheter for intractable low back pain secondary to failed back surgery syndrome returned to the operating room for removal of IT pump trial catheter after experiencing relapse of preoperative pain and pump occlusion. Initial attempt at ambulatory removal of the catheter was aborted after the patient reported acute onset of lower extremity radiculopathic pain during the extraction. Noncontrast computed tomography (CT) subsequently revealed that the catheter had ascended and coiled around the T10 nerve root. The patient was taken back to the operating room for removal of the catheter under fluoroscopic guidance, with possible laminectomy for direct visualization. Removal was ultimately achieved with slow continuous tension, with complete resolution of the patient's new radicular symptoms. LIMITATIONS: This report describes a single case report. CONCLUSION: This case demonstrates that any existing loops in the intrathecal catheter during initial implantation should be immediately re-addressed, as they can precipitate nerve root entrapment and irritation. Reduction of the loop or extrication of the catheter should be attempted under continuous fluoroscopic guidance to prevent further neurosurgical morbidity.


Asunto(s)
Catéteres de Permanencia/efectos adversos , Migración de Cuerpo Extraño/diagnóstico por imagen , Raíces Nerviosas Espinales/diagnóstico por imagen , Nervios Torácicos/diagnóstico por imagen , Adulto , Analgésicos , Cateterismo/efectos adversos , Cateterismo/instrumentación , Síndrome de Fracaso de la Cirugía Espinal Lumbar/diagnóstico por imagen , Migración de Cuerpo Extraño/cirugía , Humanos , Bombas de Infusión Implantables , Masculino , Raíces Nerviosas Espinales/cirugía , Nervios Torácicos/cirugía , Tomografía Computarizada por Rayos X
18.
Neuromodulation ; 15(6): 550-8; discussion 558-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22494013

RESUMEN

OBJECTIVES: The aim of this study was to evaluate the safety and efficacy of spinal cord stimulation (SCS) for refractory angina. MATERIALS AND METHODS: This multicenter, randomized, single-blind, controlled trial evaluated SCS in two patient groups: high stimulation (HS) (treatment) and low stimulation (LS) (control). The HS group controlled SCS with a programmer for a minimum of two hours four times daily. The LS group received SCS therapy above the paresthesia threshold for one min once daily. The primary efficacy endpoint was number of angina attacks recorded by patients at six months. The primary safety endpoint was the major adverse cardiac event (MACE) rate at six months. RESULTS: Due to slow enrollment, a futility analysis was performed, resulting in early termination of the study. Sixty-eight patients were randomized after implantation. Mean change in angina attacks per day from baseline to six months was -1.19 ± 2.13 (HS) and -1.29 ± 1.66 (LS). The difference from baseline was significant within each group (both p < 0.001) but not between groups (p = 0.45). Total exercise time and time to angina onset increased significantly from baseline to six months within each group (both p = 0.02 and 0.002) but not between groups (p = 0.52 and 0.51). MACE was similar between groups. CONCLUSION: Although this study was terminated early, the results obtained at six months suggest that SCS (HS) is not more effective than the control (LS) in patients with refractory angina.


Asunto(s)
Angina de Pecho/terapia , Estimulación de la Médula Espinal/efectos adversos , Anciano , Canadá , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Método Simple Ciego , Resultado del Tratamiento , Estados Unidos
19.
Anesthesiology ; 116(4): 896-902, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22433205

RESUMEN

BACKGROUND: Preclinical studies suggest that opioids may promote tumor growth. Genetic polymorphisms have been shown to affect opioid receptor function and to modify the clinical effects of morphine. In this study we assessed the association between six common polymorphisms in the µ-opioid receptor gene, including the well known A118G polymorphism, and breast cancer survival. METHODS: A total of 2,039 women ages 23-74 yr (38% African-American, 62% European-American, 55% postmenopausal) diagnosed with breast cancer between 1993-2001 were followed through 2006. Genotyping was performed using the TaqMan platform (Applied Biosystems Inc., Foster City, CA). Kaplan-Meier curves, log-rank tests, and Cox proportional hazard models were used to examine the association between each genotype and survival. RESULTS: After Bonferroni correction for multiple testing, patient genotype at A118G was associated with breast cancer-specific mortality at 10 yr. Women with one or more copies of the G allele had decreased breast cancer-specific mortality (P < 0.001). This association was limited to invasive cases only; effect size appeared to increase with clinical stage. Cox regression model adjusted for age and ethnicity also showed decreased mortality in A/G and G/G genotypes compared with A/A genotype (hazard ratio = 0.57 [0.38, 0.85] and 0.32 [0.22, 0.49], respectively; P = 0.006). CONCLUSIONS: These results suggest that opioid pathways may be involved in tumor growth. Further studies examining the association between genetic variants influencing opioid system function and cancer survival are warranted.


Asunto(s)
Sustitución de Aminoácidos/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/mortalidad , Polimorfismo de Nucleótido Simple/genética , Receptores Opioides mu/genética , Adulto , Anciano , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Dosificación de Gen/genética , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Tasa de Supervivencia/tendencias , Adulto Joven
20.
J Support Oncol ; 3(6): 399-408, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16350425

RESUMEN

A substantial number of patients with cancer suffer considerable pain at some point during their disease, and approximately 25% of cancer patients die in pain. Providing effective pain management for patients with severe pain that impacts quality of life can present the oncologist or palliative care specialist with complex clinical challenges that often require multifaceted therapeutic measures. This paper presents multidisciplinary consensus-based recommendations for the treatment of intractable cancer pain using intrathecal drug delivery systems, which offer rapid and effective pain relief with less toxicity relative to oral or parenteral administration. Intrathecal drug delivery systems can be highly effective in a variety of patient settings, including cases of refractory pain, diminished performance status, poor tolerability of oral medications, polyanalgesia for complex pain, and inadequate dosing due to addiction concerns. The use of implantable or external systems is discussed, as well as implantation procedures, drug titration recommendations, and management of potential side effects. The authors offer a newly developed algorithm for delivering intraspinal analgesia in patients with cancer. The intent is that increased understanding of available options for truly effective pain management in the oncology and palliative care arena and the benefits of multidisciplinary cooperation will translate into genuine improvements in patient quality of life and a measurable decrease in the number of patients who suffer needlessly in their final days.


Asunto(s)
Analgesia/métodos , Sistemas de Liberación de Medicamentos/métodos , Neoplasias/complicaciones , Dolor Intratable/tratamiento farmacológico , Analgesia/normas , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/efectos adversos , Anestésicos Locales/administración & dosificación , Anestésicos Locales/efectos adversos , Bupivacaína/administración & dosificación , Bupivacaína/efectos adversos , Sistemas de Liberación de Medicamentos/efectos adversos , Humanos , Hidromorfona/administración & dosificación , Hidromorfona/efectos adversos , Bombas de Infusión Implantables/efectos adversos , Inyecciones Espinales , Morfina/administración & dosificación , Morfina/efectos adversos , Dolor Intratable/etiología , Selección de Paciente , Complicaciones Posoperatorias
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