RESUMEN

BACKGROUND: A urine 'biomarker panel' comprising alpha-1-acid-glycoprotein, ceruloplasmin, transferrin and lipocalin-like-prostaglandin-D synthase performs to an 'excellent' level for lupus nephritis identification in children cross-sectionally. The aim of this study was to assess if this biomarker panel predicts lupus nephritis flare/remission longitudinally. METHODS: The novel urinary biomarker panel was quantified by enzyme linked immunoabsorbant assay in participants of the United Kingdom Juvenile Systemic Lupus Erythematosus (UK JSLE) Cohort Study, the Einstein Lupus Cohort, and the South African Paediatric Lupus Cohort. Monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1 were also quantified in view of evidence from other longitudinal studies. Serial urine samples were collected during routine care with detailed clinical and demographic data. A Markov Multi-State model of state transitions was fitted, with predictive clinical/biomarker factors assessed by a corrected Akaike Information Criterion (AICc) score (the better the model, the lower the AICc score). RESULTS: The study included 184 longitudinal observations from 80 patients. The homogeneous multi-state Markov model of lupus nephritis activity AICc score was 147.85. Alpha-1-acid-glycoprotein and ceruloplasmin were identified to be the best predictive factors, reducing the AICc score to 139.81 and 141.40 respectively. Ceruloplasmin was associated with the active-to-inactive transition (hazard ratio 0.60 (95% confidence interval [0.39, 0.93])), and alpha-1-acid-glycoprotein with the inactive-to-active transition (hazard ratio 1.49 (95% confidence interval [1.10, 2.02])). Inputting individual alpha-1-acid-glycoprotein/ceruloplasmin values provides 3, 6 and 12 months probabilities of state transition. CONCLUSIONS: Alpha-1-acid-glycoprotein was predictive of active lupus nephritis flare, whereas ceruloplasmin was predictive of remission. The Markov state-space model warrants testing in a prospective clinical trial of lupus nephritis biomarker led monitoring.

Asunto(s)

Ceruloplasmina/orina , Nefritis Lúpica/diagnóstico , Cadenas de Markov , Orosomucoide/orina , Adolescente , Biomarcadores/orina , Niño , Femenino , Humanos , Nefritis Lúpica/orina , Masculino

RESUMEN

The exoelectrogenic capacity of the cyanobacterium Synechococcus elongatus PCC7942 was studied in iron limited growth in order to establish conditions favouring extracellular electron transfer in cyanobacteria for photo-bioelectricity generation. Investigation into extracellular reduction of ferricyanide by Synechococcus elongatus PCC7942 demonstrated enhanced capability for the iron limited conditions in comparison to the iron sufficient conditions. Furtheremore, the significance of pH showed that higher rates of ferricyanide reduction occurred at pH 7, with a 2.7-fold increase with respect to pH 9.5 for iron sufficient cultures and 24-fold increase for iron limited cultures. The strategy presented induced exoelectrogenesis driven mainly by photosynthesis and an estimated redirection of the 28% of electrons from photosynthetic activity was achieved by the iron limited conditions. In addition, ferricyanide reduction in the dark by iron limited cultures also presented a significant improvement, with a 6-fold increase in comparison to iron sufficient cultures. Synechococcus elongatus PCC7942 ferricyanide reduction rates are unprecedented for cyanobacteria and they are comparable to those of microalgae. The redox activity of biofilms directly on ITO-coated glass, in the absence of any artificial mediator, was also enhanced under the iron limited conditions, implying that iron limitation increased exoelectrogenesis at the outer membrane level. Cyclic voltammetry of Synechococcus elongatus PCC7942 biofilms on ITO-coated glass showed a midpoint potential around 0.22 V vs. Ag/AgCl and iron limited biofilms had the capability to sustain currents in a saturated-like fashion. The present work proposes an iron related exoelectrogenic capacity of Synechococcus elongatus PCC7942 and sets a starting point for the study of this strain in order to improve photo-bioelectricity and dark-bioelectricity generation by cyanobacteria, including more sustainable mediatorless systems.

RESUMEN

Shoulder muscle fatigue has not been assessed in massive rotator cuff tear (MRCT). This study used EMG to measure fatigability of 13 shoulder muscles in 14 healthy controls and 11 patients with MRCT. A hand grip protocol was applied to minimise artifacts due to pain experience during measurement. The fatigue index (median frequency slope) was significantly non-zero (negative) for anterior, middle, and posterior parts of deltoid, supraspinatus and subscapularis muscles in the controls, and for anterior, middle, and posterior parts of deltoid, and pectoralis major in patients (p ≤ 0.001). Fatigue was significantly greater in patients compared to the controls for anterior and middle parts of deltoid and pectoralis major (p ≤ 0.001). A submaximal grip task provided a feasible way to assess shoulder muscle fatigue in MRCT patients, however with some limitations. The results suggest increased activation of deltoid is required to compensate for lost supraspinatus abduction torque. Increased pectoralis major fatigue in patients (adduction torque) likely reflected strategy to stabilise the humeral head against superior subluxing force of the deltoid. Considering physiotherapy as a primary or adjunct intervention for the management of MRCT, the findings of this study generate a base for future clinical studies aiming at the development of evidence-based protocols.

Asunto(s)

Fatiga Muscular , Lesiones del Manguito de los Rotadores , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Electromiografía , Fuerza de la Mano , Humanos , Persona de Mediana Edad

RESUMEN

This study considers the linkage of exogenously stimulated emotional stress with the neurogenic regulation of heart rate operating at very low frequencies. The objectives were three-fold: to consider the present evidence that such a linkage exists as a primary phenomenon; to compare the potential of a frequency-domain method and a time-domain method in revealing this phenomenon by characterizing heart rate variability (HRV) at frequencies of [0.0005...0.4] Hz and to design, implement and report a physiological experiment in which alternating periods of exposure to bland and high valence visual stimuli might reveal this phenomenon. A methodical challenge was to optimize the length of exposure to the stimulus such that subjects did not have time to habituate to stimuli, whilst acquiring sufficient data (heart beats) such that the ultra-low frequency (ULF) components of HRV could be described. With exposure times set to approximately 5 min, during which time the strength of the stimulus and the corresponding evoked response were considered stationary, the lowest HRV frequency component that could be characterized was 0.003 Hz. In trials with parametrically defined test data, the time-domain method based on the Ornstein­Uhlenbeck Gaussian process (OU-GP) was shown to be better than the frequency-domain method in describing the ULF components of the HRV. In an experimental cohort of 16 subjects, analysis using the OU-GP revealed evidence of cardiac regulatory mechanisms influenced by emotional valence operating in the bandwidth (ULF*) [0.002...0.01] Hz.

Asunto(s)

Electrocardiografía/métodos , Frecuencia Cardíaca , Corazón , Fenómenos Fisiológicos del Sistema Nervioso , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Procesamiento de Señales Asistido por Computador

RESUMEN

Computer-based simulation for interventional radiology training has attracted increasing attention in recent years because of its potential to train remotely from patients and to provide objective assessment of proficiency. Yet developing a high fidelity simulator with realistic tactile feedback requires accurate knowledge of forces exerted on medical devices during interventional radiology procedures. This paper presents the development and validation of a force sensor for the measurement of axial forces generated during needle, and combined cannula/trocar, puncture procedures in patients. In order to assess the performance of this sensor, in vitro measurements were obtained using needle penetration of porcine liver, kidney and muscle. The results were compared with forces measured by means of a tensile tester. Calibration results showed that the force sensor has high sensitivity and linearity. Comparison of the force profiles obtained from the sensor and the tensile tester shows that good agreement was achieved in the in vitro studies for all the tissues tested. Preliminary clinical force measurements during arterial puncture and liver biopsy procedures have been performed in patients. An example of force recording for each procedure type is presented.

Asunto(s)

Agujas , Punciones/métodos , Radiología Intervencionista/métodos , Animales , Biopsia/métodos , Calibración , Simulación por Computador , Diseño de Equipo , Análisis de Elementos Finitos , Humanos , Riñón , Hígado , Músculos , Análisis de Regresión , Estrés Mecánico , Porcinos , Tacto

RESUMEN

The heart rate variability signal derived from the ECG is a beat-to-beat record of RR-intervals and is, as a time series, irregularly sampled. It is common engineering practice to resample this record, typically at 4 Hz, onto a regular time axis for conventional analysis using IIR and FIR filters, and power spectral estimators, in the time and frequency domain, respectively. However, such interpolative resampling introduces noise into the signal and the information quality is compromised. Here, the Ornstein-Uhlenbeck third-order band-pass filter is presented which operates on data sampled at arbitrary time and preserves fidelity. The algorithm is available as open source code for MATLAB(®) (MathWorks™ Inc.) and supported by an interactive website at http://clinengnhs.liv.ac.uk/OUGP.htm.

Asunto(s)

Electrocardiografía/métodos , Frecuencia Cardíaca/fisiología , Procesamiento de Señales Asistido por Computador , Algoritmos , Humanos , Modelos Estadísticos

RESUMEN

The heart rate variability (HRV) signal derived from the ECG is a beat-to-beat record of RR intervals and is, as a time series, irregularly sampled. It is common engineering practice to resample this record, typically at 4 Hz, onto a regular time axis for analysis in advance of time domain filtering and spectral analysis based on the DFT. However, it is recognised that resampling introduces noise and frequency bias. The present work describes the implementation of a time-varying filter using a smoothing priors approach based on a Gaussian process model, which does not require data to be regular in time. Its output is directly compatible with the Lomb-Scargle algorithm for power density estimation. A web-based demonstration is available over the Internet for exemplar data. The MATLAB (MathWorks Inc.) code can be downloaded as open source.

Asunto(s)

Frecuencia Cardíaca/fisiología , Modelos Cardiovasculares , Adulto , Algoritmos , Electrocardiografía/métodos , Humanos , Internet , Modelos Estadísticos , Programas Informáticos

RESUMEN

A new configuration of the fluid dynamic gauging technique for measuring soft layers on surfaces was used to monitor the growth of a cyanobacterium, Synechococcus sp. WH 5701, on stainless steel (SS), glass and an indium tin oxide (ITO) on a polyethylene terephthalate (PET) substratum. The biofilm thickness increased steadily over 4 weeks and exhibited noticeable changes in microstructure and strength. The biofilms all exhibited a two-layer structure, with a compact layer next to the substratum and a loose layer above. Biofilms on ITO or SS exhibited cohesive failure when removed by fluid shear whereas those on glass exhibited adhesive failure. The technique is able to elucidate various aspects of biofilm behaviour, as illustrated by the action of a biocide (NaOCl) on a mature biofilm.

Asunto(s)

Biopelículas/crecimiento & desarrollo , Microfluídica/instrumentación , Synechococcus/fisiología , Biopelículas/efectos de los fármacos , Desinfectantes/farmacología , Vidrio/química , Microfluídica/métodos , Tereftalatos Polietilenos/química , Hipoclorito de Sodio/farmacología , Acero Inoxidable/química , Synechococcus/efectos de los fármacos , Synechococcus/crecimiento & desarrollo , Factores de Tiempo , Compuestos de Estaño/química

RESUMEN

PURPOSE: Reliable electromyographic evaluation of the shoulder in common painful conditions is a major challenge due to a reduced range of movement and pain-related muscle inhibition. This study investigates the use of a hand grip task for the assessment of shoulder muscle activation. METHODS: Muscle activity and fatigue for supraspinatus and infraspinatus muscles were measured in 16 healthy controls using fine-wire electrodes during a controlled gripping task at 50% of maximum voluntary contraction, in a standardized sitting and arm position. Changes in muscle activity and fatigue were measured by the time-slope of root mean square amplitude and median frequency, respectively. RESULTS: A significant positive amplitude slope (p<0.01) was found for both supraspinatus and infraspinatus, indicating that the task resulted in increasing muscle activity. Judging by the median frequency slope, there was no sign of fatigue progression. CONCLUSION: A standardized hand grip task in a neutral position activates key rotator cuff muscles. This might provide a method for electromyographic assessment of shoulder girdle muscles which avoids problems due to pain-related limitation of movement, and might be useful in the development and monitoring of shoulder rehabilitation strategies.

Asunto(s)

Fuerza de la Mano/fisiología , Contracción Muscular/fisiología , Fatiga Muscular/fisiología , Músculo Esquelético/fisiología , Articulación del Hombro/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad

RESUMEN

OBJECTIVE: As a component of healthcare reform, payers, hospital administrators, and physicians are looking for ways to reduce hospital expenditures and improve efficiency. The economic benefit of a reduced hospital stay must be weighed against the cost of the treatment or process necessary to achieve the reduced length of stay (LOS). The objective of this paper was to estimate the potential economic benefit of a reduction in inpatient hospital LOS for a common type of admission, community acquired pneumonia (CAP). RESEARCH DESIGN AND METHODS: Data for this study were from the CAP hospital admissions selected from the 2006 Healthcare Cost and Utilization Project (HCUP) National Inpatient Sample (NIS). Potential savings associated with a 1 day reduction in CAP LOS were estimated using three methods: (1) average cost, (2) weighted-average incremental cost of an additional day, and (3) weighted-average predicted mean costs from regression models which were used to estimate incremental cost adjusting for hospitalization characteristics. MAIN OUTCOME MEASURES: Cost per day of CAP hospitalization. RESULTS: A total of 1,471,295 CAP admissions qualified for the analysis. The cost for each day of reduction in LOS in 2009 US dollars was $2273, $2373, and $2319 for the three methods: simple average, incremental, and regression, respectively. Subgroup analysis and regression analysis indicated higher costs were identified: in patients who died in the hospital, had hospital stays in the Northeast or West, and in large hospitals. Longer CAP hospitalizations had a higher cost per additional day. Limitations include those typically associated with the use of administrative claims (e.g., lack of clinical detail, issues related to diagnosis coding). CONCLUSIONS: Eliminating a day during the course of a CAP admission is potentially worth $2273-2373 in economic benefits (2009 dollars). As we strive for greater efficiency in healthcare delivery, changes in processes and/or improved diagnostics or treatments may potentially achieve a reduction in the length of stay. The cost of such changes or improvements must be weighed against the economic benefit of a shorter hospitalization.

Asunto(s)

Infecciones Comunitarias Adquiridas/economía , Administración Hospitalaria/economía , Precios de Hospital/estadística & datos numéricos , Tiempo de Internación/economía , Neumonía/economía , Factores de Edad , Anciano , Infecciones Comunitarias Adquiridas/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Económicos , Neumonía/terapia , Características de la Residencia , Factores Sexuales

RESUMEN

The mfERG has proven to be a useful tool in determining central retinal and macular function. It is, however, reliant on good subject co-operation and fixation. This cannot always be guaranteed due to visual impairment or poor co-operation. Whilst a change in fixation is easy to identify with camera monitoring of the subject, a small eccentric fixation can be difficult to notice or quantify. Whilst the problem of fixation can be obviated by stimulating the retina directly with SLO (Scanning Laser Ophthalmoscope), this is expensive and a certain amount of expertize in optics is required to properly stimulate the retina. In this study, peak latency of response was investigated to see whether it changed across the retina and whether this measure could be used to help assess fixation. Eighteen normal eyes were stimulated using a 60 Hz CRT monitor with only 2 hexagons, one central and one peripheral. These hexagons were presented at three stimulation rates, fast (no filler frames between steps of the m-sequence) and slow (4 and 7 black filler frames between each step of the m-sequence), under all conditions significantly increased central hexagon latencies were noted. In a smaller experiment with 19 hexagons and only 4 subjects, it was noted a significant delay in latency was observed in ring 1 compared to ring 2 and 3 with central fixation, but not when the subjects fixed mid-peripheral and in the periphery to slow stimulation, showing that the central hexagon response was only delayed in the central hexagon when there was adequate fixation. This study suggests that latency could provide a clue to fixation particular at slow rates thereby improving the quality and confidence of recordings made clinically.

Asunto(s)

Electrorretinografía/métodos , Fijación Ocular , Tiempo de Reacción , Humanos , Mácula Lútea/fisiología , Estimulación Luminosa/métodos , Factores de Tiempo , Visión Ocular

RESUMEN

BACKGROUND: We have developed the 'Optimising Surgical Care and Assessment Record' (OSCAR), a clinical decision support system, to help nurses in predicting necessary preoperative investigations before surgery. OSCAR applies the hospital's protocols, which are based on the National Institute for Health and Clinical Excellence guidelines, to the patient's medical history and surgical details before recommending required investigations. METHODS: We selected case notes of 50 patients randomly from the OSCAR system that were recorded between October 2006 and January 2007. To form a reference standard, these case histories were anonymized and then sent to 10 consultant anaesthetists across the country. They were asked to study the case history and choose which tests they would carry out and which they would not. Then we have evaluated OSCAR's ability to predict the necessary investigations and the nurses' judgement, in comparison with the reference standard. RESULTS: OSCAR's ability to identify which investigations should be carried out, that is, its sensitivity, was 91.5% and its ability to identify which investigations not to carry out, that is, its specificity, was 82.7%. OSCAR was consistent in predicting investigations for differing severities of surgery, for ASA grade and gender. We were unable to demonstrate any overall difference between OSCAR and the nurse's ability to predict preoperative investigations. When combining the nurse's predictions with OSCAR's recommendations, an even greater sensitivity of 98.2% could be achieved. CONCLUSIONS: OSCAR's prediction algorithm cannot replace the nurse's judgement, but it can be used as a supplementary decision aid to promote consistency and improve accuracy.

Asunto(s)

Técnicas de Apoyo para la Decisión , Evaluación en Enfermería/métodos , Cuidados Preoperatorios/métodos , Adulto , Anciano , Algoritmos , Protocolos Clínicos , Inglaterra , Métodos Epidemiológicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Necesidades , Investigación en Evaluación de Enfermería , Personal de Enfermería en Hospital , Índice de Severidad de la Enfermedad

RESUMEN

Little is known about how knot-pusher design affects arthroscopic knot tying. In our practice, we observed the knot-pusher riding onto the arthroscopic knot at the point of maximum tightening. This can lead to snagging of the knot, which is undesirable as it may lead to loosening of, or damage to the knot. The aim of this study is to determine the optimum size of a knot-pusher to efficiently push the knot without overriding or snagging it. We used an apparatus to model arthropcopic knot tying. Ten examples each of the Duncan loop were tied under controlled conditions of load using one polydioxanone (PDS) monofilament absorbable suture (Ethicon, Livingston, UK), two Ethibond, two Fibrewire and two Panacryl. The loop of the knot was then secured and a 50 N force applied to tension the knot. The suture diameter was measured. Then the knot diameter was measured in two planes using an analogue micrometer. The internal diameter of a Mitek knot-pusher was measured. The mean maximum diameter for each knot was respectively PDS, 2.061 +/- 0.13 mm; Panacryl, 1.907 +/- 0.14 mm; Ethibond, 1.717 +/- 0.16 mm and Fibrewire, 1.654 +/- 0.14 mm. There were significant differences in size between knots tied with different materials except between Ethibond and Fibrewire where the difference was not significant. For each set of knots the smallest maximum knot diameter observed was identified. This was respectively PDS, 1.92 mm; Ethibond, 1.476 mm; Fibrewire, 1.488 mm and Panacryl, 1.715 mm. The internal diameter of a Mitek knot-pusher was found to be 1.95 mm. The current Mitek knot-pusher appears to be well suited to one PDS and two Panacryl. It appears less ideal for two Ethibond and two Fibrewire. One knot-pusher does not fit all and we suggest that different knot-pushers be used for different suture materials.

Asunto(s)

Artroscopía , Técnicas de Sutura/instrumentación , Diseño de Equipo , Humanos , Ensayo de Materiales/métodos , Modelos Anatómicos , Suturas

RESUMEN

A system is described for the removal of eye movement and blink artefacts from single channel pattern reversal electroretinogram recordings of very poor signal-to-noise ratios. Artefacts are detected and removed by using a blind source separation technique based on the jadeR independent component analysis algorithm. The single channel data are arranged as a series of overlapping time-delayed vectors forming a dynamical embedding matrix. The structure of this matrix is constrained to the phase of the stimulation epoch: the term synchronous dynamical embedding is coined. A novel method using a marker channel with a non-independent synchronous feature is employed to identify the single most relevant source estimation for reconstruction and signal recovery. This method is non-lossy, all underlying signal being recovered. In synthetic datasets of defined noise content and in standardised real data recordings, the performance of this technique is compared to conventional fixed-threshold hard-limit rejection. The most significant relative improvements are achieved when movement and blink artefacts are greatest: no improvement is demonstrable for the random noise only situation.

Asunto(s)

Interpretación Estadística de Datos , Electrorretinografía , Potenciales Evocados Visuales/fisiología , Artefactos , Recolección de Datos , Movimientos Oculares , Sensibilidad y Especificidad

RESUMEN

PURPOSE: The aetiology of tennis elbow has remained uncertain for more than a century. To examine muscle imbalance as a possible pathophysiological factor requires a reliable method of assessment. This paper describes the development of such a method and its performance in healthy subjects. We propose a combination of surface and fine-wire EMG of shoulder and forearm muscles and wrist strength measurements as a reliable tool for assessing muscle imbalance relevant to the pathophysiology of tennis elbow. METHODS: Six healthy volunteers participated. EMG data were acquired at 50% maximal voluntary isometric contraction from five forearm muscles during grip and three shoulder muscles during external rotation and abduction, and analysed using normalized median frequency slope as a fatigue index. Wrist extension/flexion strength was measured using a purpose-built dynamometer. RESULTS: Significant negative slope of median frequency was found for all muscles, with good reproducibility, and no significant difference in slope between the different muscles of the shoulder and the wrist. (Amplitude slope showed high variability and was therefore unsuitable for this purpose.) Wrist flexion was 27+/-8% stronger than extension (mean+/-SEM, p=0.006). CONCLUSION: This is a reliable method for measuring muscle fatigue in forearm and shoulder. EMG and wrist strength studies together can be used for assessing and identifying the muscle balance in the wrist-forearm-shoulder chain.

Asunto(s)

Fatiga Muscular/fisiología , Fuerza Muscular/fisiología , Codo de Tenista/fisiopatología , Extremidad Superior/fisiopatología , Adulto , Anciano , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Contracción Muscular/fisiología , Dinamómetro de Fuerza Muscular , Rotación

RESUMEN

We describe the application of wide-field frequency domain Fluorescence Lifetime Imaging Microscopy (FLIM) to imaging in microfluidic devices. FLIM is performed using low cost, intensity modulated Light Emitting Diodes (LEDs) for illumination. The use of lifetime imaging for quantitative analysis within such devices is demonstrated by mapping the molecular diffusion of iodide ions across a microchannel.

RESUMEN

This is the first prospective clinical trial in which patients with acute bacterial exacerbation of chronic bronchitis have been stratified by degree of underlying illness. Uncomplicated patients were randomised to levofloxacin 750 mg once daily (q.d.) for 3 days or azithromycin q.d. for 5 days. Complicated patients were randomised to levofloxacin 750 mg q.d. for 5 days or amoxicillin 875 mg/clavulanate 125 mg twice daily for 10 days. Regardless of therapy, complicated patients demonstrated lower clinical and microbiological success than uncomplicated patients. Clinical success for clinically evaluable patients was similar for levofloxacin and azithromycin (93.0 versus 90.1%, respectively), and levofloxacin and amoxicillin/clavulanate (79.2 versus 81.7%, respectively). For microbiologically evaluable patients, clinical response to levofloxacin for 3 days was superior to azithromycin for 5 days (96.3 versus 87.4%, respectively), and levofloxacin for 5 days was similar to amoxicillin/clavulanate for 10 days (81.4 versus 80.9%, respectively). Microbiological eradication was superior for levofloxacin for 3 days compared with azithromycin for 5 days (93.8 versus 82.8%, respectively), and similar for levofloxacin and amoxicillin/clavulanate for 10 days (81.4 versus 79.8%, respectively). In conclusion, levofloxacin 750 mg for 3 days was comparable to azithromycin for 5 days for uncomplicated patients with acute bacterial exacerbation of chronic bronchitis, while 5 days of 750 mg levofloxacin was comparable to 10 days of amoxicillin/clavulanate for complicated acute bacterial exacerbation of chronic bronchitis.

Asunto(s)

Antibacterianos/administración & dosificación , Bronquitis Crónica/tratamiento farmacológico , Bronquitis Crónica/microbiología , Levofloxacino , Ofloxacino/administración & dosificación , Selección de Paciente , Administración Oral , Adolescente , Corticoesteroides/uso terapéutico , Adulto , Anciano , Combinación Amoxicilina-Clavulanato de Potasio/administración & dosificación , Combinación Amoxicilina-Clavulanato de Potasio/efectos adversos , Combinación Amoxicilina-Clavulanato de Potasio/economía , Antibacterianos/efectos adversos , Antibacterianos/economía , Enfermedad Crónica , Análisis Costo-Beneficio , Diarrea/inducido químicamente , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Quimioterapia Combinada , Femenino , Haemophilus influenzae/efectos de los fármacos , Haemophilus influenzae/aislamiento & purificación , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Náusea/inducido químicamente , Ofloxacino/efectos adversos , Ofloxacino/economía , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/aislamiento & purificación , Resultado del Tratamiento

RESUMEN

In few types of cancer, genomic abnormalities have been linked to the phenotype and carcinogenesis with a degree of precision. For most cancers, however, this is not the case and the literature provides no clear indication of any logical process. The main difficulties are the great redundancy within the genome and proteome, the vast number of interconnections and the vast number of feedback loops. Such complicated systems can be modelled, but will require highly sophisticated analysis using computational mathematics techniques. Neural networks have been in common use in medical research for the past 20 years. They have been used for classification and for prediction of hazard or failure but are still not widely used for explanation. The binary output can be modified by, for example, adding a Bayesian function to the output stage so that survival probabilities can be given. We looked at the application of probabilistic neural networks in providing prognosis in two types of cancer; laryngeal carcinoma which has a relatively short hazard time and a medium survival rate and ocular melanoma with longer hazard time and higher survival rate. We compared their performance with the more traditional methods and studied their limitations and boundaries.

RESUMEN

We used a novel perfusion system to expose cultured human umbilical vein endothelial cells (HUVEC) to water-soluble components of cigarette smoke and study subsequent adhesion of flowing neutrophils. Neutrophils did not bind to HUVEC immediately after it had been exposed to cigarette smoke, but many adhered 90-150 min after exposure. The effect was reduced if the exposed medium was made serum-free, but this reduction was partially reversed if low density lipoprotein was added. Treatment of smoke-exposed HUVEC with antibodies against E-selectin or P-selectin reduced adhesion by approximately 50% or 75%, respectively; a combination of both antibodies essentially abolished adhesion. Enzyme-linked immunosorbent assay confirmed that exposure to smoke caused HUVEC to upregulate surface expression of E- and P-selectin. Thus, water-soluble constituent(s) of cigarette smoke cause efficient selectin-mediated capture of flowing neutrophils. This pro-inflammatory response may contribute to pathology associated with smoking, especially in tissues remote from the lung.

Asunto(s)

Adhesión Celular/fisiología , Endotelio Vascular/fisiopatología , Neutrófilos/fisiología , Selectinas/fisiología , Fumar/patología , Medios de Cultivo , Humanos , Técnicas In Vitro , Perfusión

RESUMEN

An apparatus has been developed to enable the in vitro measurement of the kinematics and kinetics of a slipknot, both while the knot is being tightened and with the knot in place and the tension removed. During tightening, the apparatus provides a linearly increasing resistance, which may be considered analogous to the resistance experienced when the labrum is drawn toward and apposed to the edge of the glenoid cavity during a Bankart repair. The tension to close the knot is measured with a tensiometer, in tandem with the closure of the capsule model onto the bone anchor, which is measured with a datalogger. The tightening tension was limited to 25 N and intraoperator and interoperator comparisons were made for four knots tied by six participants. Failure of a knot was taken to be reverse slippage of 2 mm. A second criterion of ease of slide was used to assess each knot. We found wide interoperator variability with regard to slipknot tying. A methodology for quality control of slipknot tying is presented.

Asunto(s)

Artroscopía , Inestabilidad de la Articulación/cirugía , Articulación del Hombro/cirugía , Suturas , Fenómenos Biomecánicos , Humanos , Polidioxanona