Clinical effectiveness of biologics in clinical practice

TNF inhibitors are currently considered both effective and cost-effective in patients with active rheumatoid arthritis (RA), particularly in patients who have not responded fully to methotrexate. There is substantial doubt about the cost-effectiveness of TNF inhibitors as initial treatment for active RA. New data from the National Data Bank for Rheumatic Diseases now question the current consensus in methotrexate failures. The data suggest that in routine clinical practice TNF inhibitors provide only modest incremental benefits over best conventional therapy. If confirmed, these observational studies suggest that the economic argument underpinning the widespread use of TNF inhibitors in established RA is unsustainable.     

Conventional methods and future trends in antimicrobial susceptibility testing

Antimicrobial susceptibility testing is an essential task for selecting appropriate antimicrobial agents to treat infectious diseases. Constant evolution has been observed in methods used in the diagnostic microbiology laboratories. Disc diffusion or broth microdilution are classical and conventional phenotypic methods with long turnaround time and labour-intensive but still widely practiced as gold-standard. Scientists are striving to develop innovative, novel and faster methods of antimicrobial susceptibility testing to be applicable for routine microbiological laboratory practice and research. To meet the requirements, there is an increasing trend towards automation, genotypic and micro/nano technology-based innovations. Automation in detection systems and integration of computers for online data analysis and data sharing are giant leaps towards versatile nature of automated methods currently in use. Genotypic methods detect a specific genetic marker associated with resistant phenotypes using molecular amplification techniques and genome sequencing. Microfluidics and microdroplets are recent addition in the continuous advancement of methods that show great promises with regards to safety and speed and have the prospect to identify and monitor resistance mechanisms. Although genotypic and microfluidics methods have many exciting features, however, their applications into routine clinical laboratory practice warrant extensive validation. The main impetus behind the evolution of methods in antimicrobial susceptibility testing is to shorten the overall turnaround time in obtaining the results and to enhance the ease of sample processing. This comprehensive narrative review summarises major conventional phenotypic methods and automated systems currently in use, and highlights principles of some of the emerging genotypic and micro/nanotechnology-based methods in antimicrobial susceptibility testing.     

A direct comparison of patient and force-controlled simulator total knee replacement kinematics

The need to critically evaluate the efficacy of current total knee replacement (TKR) wear testing methodologies is great. Proposed international standards for TKR wear simulation have been drafted, yet their methods continue to be debated. The "gold standard" to which all TKR wear testing methodologies should be compared is measured in vivo TKR performance in patients. The current study compared patient TKR kinematics from fluoroscopic analysis and simulator TKR kinematics from force-controlled wear testing to quantify similarities in clinical ranges of motion and contact bearing kinematics and to evaluate the proposed ISO force-controlled wear testing methodology. The treadmill walking kinematics from eight well-functioning, 13 month average post-op patients were compared to the 2 million cycle interval walking cycle kinematics from a force-controlled (Instron/Stanmore Knee Joint Simulator, Instron, Canton, MA) knee simulator using identical implant designs (Natural Knee II, Standard Congruent, Zimmer, Warsaw, IN). The in vivo and simulator data showed good agreement in kinematic patterns and ranges of clinical motion. Tribologically the data sets showed similar contact pathway ranges of motion and wear travel distances per cycle. Surgical and simulator alignments of the implant systems were determined to be a contributing factor in observed kinematic differences. This study's statistical findings offer supporting evidence that the simulation of in vivo walking cycle wear kinematics can be accurately reproduced with a force controlled testing methodology.     

Evaluating the validity and reliability of inertial measurement units for determining knee and trunk kinematics during athletic landing and cutting movements

Inertial Measurement Units (IMUs) are promising alternatives to laboratory-based motion capture methods in biomechanical assessment of athletic movements. The aim of this study was to investigate the validity of an IMU system for determining knee and trunk kinematics during landing and cutting tasks for clinical and research applications in sporting populations. Twenty-seven participants performed five cutting and landing tasks while being recorded using a gold-standard optoelectronic motion capture system and an IMU system. Intra-class coefficients, Pearson’s r, root-mean-square error (RMSE), bias, and Bland-Altman limits of agreements between the motion capture and IMU systems were quantified for knee and trunk sagittal- and frontal-plane range-of-motion (ROM) and peak angles. Our results indicate that IMU validity was task-, joint-, and plane-dependent. Based on good-to-excellent (ICC) correlation, reasonable accuracy (RMSE < 5°), bias within 2°, and limits of agreements within 10°, we recommend the use of this IMU system for knee sagittal-plane ROM estimations during cutting, trunk sagittal-plane peak angle estimation during the double-leg landing task, trunk sagittal-plane ROM estimation for almost all tasks, and trunk frontal-plane peak angle estimation for the right single-leg landing task. Due to poor comparisons with the optoelectronic system, we do not recommend this IMU system for knee frontal-plane kinematic estimations.     

Across-subject calibration of an instrumented glove to measure hand movement for clinical purposes

Motion capture of all degrees of freedom of the hand collected during performance of daily living activities remains challenging. Instrumented gloves are an attractive option because of their higher ease of use. However, subject-specific calibration of gloves is lengthy and has limitations for individuals with disabilities. Here, a calibration procedure is presented, consisting in the recording of just a simple hand position so as to allow capture of the kinematics of 16 hand joints during daily life activities even in case of severe injured hands. ‘across-subject gains’ were obtained by averaging the gains obtained from a detailed subject-specific calibration involving 44 registrations that was repeated three times on multiple days to 6 subjects. In additional 4 subjects, joint angles that resulted from applying the ‘across-subject calibration’ or the subject-specific calibration were compared. Global errors associated with the ‘across-subject calibration’ relative to the detailed, subject-specific protocol were small (bias: 0.49°; precision: 4.45°) and comparable to those that resulted from repeating the detailed protocol with the same subject on multiple days (0.36°; 3.50°). Furthermore, in one subject, performance of the ‘across-subject calibration’ was directly compared to another fast calibration method, expressed relative to a videogrammetric protocol as a gold-standard, yielding better results.     

Computer-Assisted Interpretation of the EEG Background Pattern: A Clinical Evaluation

Objective

Interpretation of the EEG background pattern in routine recordings is an important part of clinical reviews. We evaluated the feasibility of an automated analysis system to assist reviewers with evaluation of the general properties in the EEG background pattern.

Methods

Quantitative EEG methods were used to describe the following five background properties: posterior dominant rhythm frequency and reactivity, anterior-posterior gradients, presence of diffuse slow-wave activity and asymmetry. Software running the quantitative methods were given to ten experienced electroencephalographers together with 45 routine EEG recordings and computer-generated reports. Participants were asked to review the EEGs by visual analysis first, and afterwards to compare their findings with the generated reports and correct mistakes made by the system. Corrected reports were returned for comparison.

Results

Using a gold-standard derived from the consensus of reviewers, inter-rater agreement was calculated for all reviewers and for automated interpretation. Automated interpretation together with most participants showed high (kappa > 0.6) agreement with the gold standard. In some cases, automated analysis showed higher agreement with the gold standard than participants. When asked in a questionnaire after the study, all participants considered computer-assisted interpretation to be useful for every day use in routine reviews.

Conclusions

Automated interpretation methods proved to be accurate and were considered to be useful by all participants.

Significance

Computer-assisted interpretation of the EEG background pattern can bring consistency to reviewing and improve efficiency and inter-rater agreement.     

Influence of joint constraints on lower limb kinematics estimation from skin markers using global optimization

In order to obtain the lower limb kinematics from skin-based markers, the soft tissue artefact (STA) has to be compensated. Global optimization (GO) methods rely on a predefined kinematic model and attempt to limit STA by minimizing the differences between model predicted and skin-based marker positions. Thus, the reliability of GO methods depends directly on the chosen model, whose influence is not well known yet.This study develops a GO method that allows to easily implement different sets of joint constraints in order to assess their influence on the lower limb kinematics during gait. The segment definition was based on generalized coordinates giving only linear or quadratic joint constraints. Seven sets of joint constraints were assessed, corresponding to different kinematic models at the ankle, knee and hip: SSS, USS, PSS, SHS, SPS, UHS and PPS (where S, U and H stand for spherical, universal and hinge joints and P for parallel mechanism). GO was applied to gait data from five healthy males.Results showed that the lower limb kinematics, except hip kinematics, knee and ankle flexion–extension, significantly depend on the chosen ankle and knee constraints. The knee parallel mechanism generated some typical knee rotation patterns previously observed in lower limb kinematic studies. Furthermore, only the parallel mechanisms produced joint displacements.Thus, GO using parallel mechanism seems promising. It also offers some perspectives of subject-specific joint constraints.     

Gender,Brain-Derived Neurotrophic Factor Val66Met,and Frequency of Methamphetamine Use

BackgroundFrequency of pretreatment methamphetamine (MA) use is an important predictor of outcomes of treatment for MA dependence. Preclinical studies suggest females self-administer more MA than males, but few clinical studies have examined potential sex differences in the frequency of MA use. Estrogen increases expression of brain-derived neurotrophic factor (BDNF), which has effects on MA-induced striatal dopamine release and protects against MA-induced neurotoxicity.ObjectiveWe examined potential effects of sex, the Val66Met polymorphism in BDNF, and their interaction on frequency of MA use among 60 Caucasian MA-dependent volunteers screening for a clinical trial.MethodsData was taken from 60 Caucasian MA-dependent volunteers screening for a clinical trial.ResultsFemales reported significantly more pretreatment days with MA use in the past 30 days than males. There was a significant interaction between sex and BDNF Val66Met, with the highest frequency of MA use among females with Val/Val genotype.ConclusionsThese results, although preliminary, add to the literature documenting sexual dimorphism in response to stimulants, including MA, and suggest a potential biological mechanism involving BDNF that might contribute to these differences. Additional research characterizing the biological basis of altered response to MA among females is warranted.     

Methods of induced pluripotent stem cells for clinical application

Reprograming somatic cells using exogenetic gene expression represents a groundbreaking step in regenerative medicine. Induced pluripotent stem cells(i PSCs) are expected to yield novel therapies with the potential to solve many issues involving incurable diseases. In particular, applying i PSCs clinically holds the promise of addressing the problems of immune rejection and ethics that have hampered the clinical applications of embryonic stem cells. However, as i PSC research has progressed, new problems have emerged that need to be solved before the routine clinical application of i PSCs can become established. In this review, we discuss the current technologies and future problems of human i PSC generation methods for clinical use.     

Contributions to variability of clinical measures for use as indicators of udder health status in a clinical protocol

A cross-sectional observational study with repeated observations was conducted on 16 Danish dairy farms to quantify the influence of observer, parity, time (stage in lactation) and farm on variables routinely selected for inclusion in clinical protocols, thereby to enable a more valid comparison of udder health between different herds. During 12 months, participating herds were visited 5 times by project technicians, who examined 20 cows and scored the selected clinical variables. The estimates of effect on variables were derived from a random regression model procedure. Statistical analyses revealed that, although estimates for occurrence of several the variables, e.g. degree of oedema, varied significantly between observers, the effects on many of these estimates were similar in size. Almost all estimates for occurrences of variables were significantly affected either parity and lactation stage, or by both e.g. udder tissue consistency. Some variables, e.g. mange, had high estimates for the farm component, and others e.g. teat skin quality had a high individual component. Several of the variables, e.g. wounds on warts, had a high residual component indicating that a there still was a major part of the variation in data, which was unexplained. It was concluded that most of the variables were relevant for implementation in herd health management, but that adjustments need to be made to improve reliability.     

A musculoskeletal foot model for clinical gait analysis

Several full body musculoskeletal models have been developed for research applications and these models may potentially be developed into useful clinical tools to assess gait pathologies. Existing full-body musculoskeletal models treat the foot as a single segment and ignore the motions of the intrinsic joints of the foot. This assumption limits the use of such models in clinical cases with significant foot deformities. Therefore, a three-segment musculoskeletal model of the foot was developed to match the segmentation of a recently developed multi-segment kinematic foot model. All the muscles and ligaments of the foot spanning the modeled joints were included. Muscle pathways were adjusted with an optimization routine to minimize the difference between the muscle flexion–extension moment arms from the model and moment arms reported in literature. The model was driven by walking data from five normal pediatric subjects (aged 10.6±1.57 years) and muscle forces and activation levels required to produce joint motions were calculated using an inverse dynamic analysis approach. Due to the close proximity of markers on the foot, small marker placement error during motion data collection may lead to significant differences in musculoskeletal model outcomes. Therefore, an optimization routine was developed to enforce joint constraints, optimally scale each segment length and adjust marker positions. To evaluate the model outcomes, the muscle activation patterns during walking were compared with electromyography (EMG) activation patterns reported in the literature. Model-generated muscle activation patterns were observed to be similar to the EMG activation patterns.     

Peripheral eosinophilia as an indicator of meningitic angiostrongyliasis in exposed individuals

The diagnosis of meningitic angiostrongyliasis (MA) is based on clinical criteria. A lumbar puncture is used as a diagnostic tool, but it is an invasive procedure. The blood eosinophil levels are also assessed and used in the diagnosis of this disease. We enrolled 47 patients with serologically proven MA and 131 controls with intestinal parasite infections. An absolute eosinophil count model was found to be the best marker for MA. An eosinophil count of more than 798 cells led to sensitivity, specificity, positive predictive and negative predictive values of 76.6%, 80.2%, 58.1% and 90.5%, respectively. These data support the use of testing for high blood eosinophil levels as a diagnostic tool for MA in individuals that are at risk for this disease.     

Application of nucleic acid amplification in clinical microbiology

The use of nucleic acid amplification methods in routine clinical microbiology laboratories is becoming increasingly widespread. The theory of polymerase chain reaction is described, including discussion of suitable microbal targets, extraction of nucleic acid from clinical samples, choice of primers, optimization of the process, laboratory design, contamination, and other problems as well as quality control. Other nucleic acid amplification methods such as ligase chain reaction, self-sustained sequence replication, strand displacement amplification, and branched DNA signal amplification are described and the choice of technology is discussed.     

Strong association between P53 protein accumulation, serum antibodies and gene mutation in non-small cell lung cancer

DNA sequencing is the gold-standard method, but it is not feasible on a routine clinical basis. Immunohistochemistry is the most widely used method for assessing P53 alterations in human cancers. It can be performed during routine analysis, but some mutations may not lead to P53 protein accumulation, or P53 overexpression may be detected in the absence of mutations of the P53 gene. Recent studies have demonstrated the appearance of P53 antibodies in the serum of patients with lung cancer, probably due to the accumulation of mutant P53 protein in tumor cells. Using a logistic regression model applied to data for 102 non-small cell lung cancer (NSCLC) patients, we show a strong association between results of P53 mutation (P53-M) test, TNM stage and results of anti-P53 antibody in serum (P53-Abs) and P53 protein expression (P53-PE) tests. According to that model, we propose a procedure allowing for prediction of result of P53-M test. The percentage of correct predictions for independent data of 15 NSCLC patients was 80%. We conclude that in the absence of P53-M test result, a reasonably precise prediction of the test can be obtained using TNM stage and results of P53-Abs and P53-PE tests. The prediction can in turn be used to evaluate prognosis of NSCLC patients.     

Clinical validity of outcome pain measures in naturally occurring canine osteoarthritis

ABSTRACT: BACKGROUND: The conceptual validity of kinetic gait analysis and disability outcome assessment methods has guided their use in the assessment of pain caused by osteoarthritis (OA). No consensus on the best clinical methods for pain evaluation in canine OA exists, particularly, when evaluating treatments where a smaller treatment effect is anticipated than with pharmacological pain killers. This study thus aimed at determining the technical validity of some clinical endpoints on OA pain in dogs using the green-lipped mussel (GLM)-enriched diet. Twenty-three adult dogs with clinical OA completed the prospective controlled study. All the dogs were fed a balanced diet over a 30-day control period followed by a GLM-enriched diet over a 60-day period. The kinetic gait analysis parameter (PVFBW, peak vertical force adjusted for body weight change), electrodermal activity (EDA), and a standardized multifactorial pain questionnaire (MFQ) were performed on day (D) 0 (inclusion), D30 (start) and D90 (end). The owners completed a client-specific outcome measures (CSOM) instrument twice a week. Motor activity (MA) was continuously recorded in seven dogs using telemetered accelerometric counts. We hypothesized that these methods would produce convergent results related to diet changes. A Type I error of 0.05 was adjusted to correct for the multiplicity of the primary clinical endpoints. RESULTS: Neither the EDA nor the MFQ were found reliable or could be validated. Changes in the PVFBW (Padj = 0.0004), the CSOM (Padj = 0.006) and the MA intensity (Padj = 0.02) from D0 to D90 suggested an effect of diet(s). Only the PVFBW clearly increased after the GLM-diet (Padj = 0.003). The CSOM exhibited a negative relationship with the PVFBW (P = 0.02) and MA duration (P = 0.02). CONCLUSIONS: The PVFBW exhibited the best technical validity for the characterization of the beneficial effect of a GLM-enriched diet. The CSOM and MA appeared less responsive following a GLM-diet, but these measures appeared complementary to gait analysis. Apparently, the CSOM provides the capacity to rely on pain OA assessment influenced by both lameness quantification (PVFBW) and physical functioning (MA).     

Immuno‐MALDI‐TOF MS: New perspectives for clinical applications of mass spectrometry

The discovery of novel biomarkers by means of advanced detection tools based on proteomic analysis technologies necessitates the development of improved diagnostic methods for application in clinical routine. On the basis of three different application examples, this review presents the limitations of conventional routine diagnostic assays and illustrates the advantages of immunoaffinity enrichment combined with MALDI‐TOF MS. Applying this approach increases the specificity of the analysis supporting a better diagnostic recognition, sensitivity, and differentiation of certain diseases. The use of MALDI‐TOF MS as detection method facilitates the identification of modified peptides and proteins providing additional information. Further, employing respective internal standard peptides allows for relative and absolute quantitation which is mandatory in the clinical context. Although MALDI‐TOF MS is not yet established for clinical routine diagnostics this technology has a high potential for improvement of clinical diagnostics and monitoring therapeutic efficacy.     

Molecular methods used in clinical laboratory: prospects and pitfalls

The role of molecular detection, identification and typing or fingerprinting of microorganisms has shifted gradually from the academic world to the routine diagnostic laboratory. Molecular methods have been used increasingly over the past decade to improve the sensitivity, specificity and turn-around time in the clinical laboratory. Molecular methods have also been used to identify new and nonculturable agents. Many high-throughput molecular tests are now available commercially, which impacts on the infrastructure in many of the diagnostic laboratories. In this paper, we take an overall look at the use of molecular methods (prospects vs. pitfalls) based on our clinical and public health experience, particularly as they related to Borrelia burgdorferi, a vector-borne pathogen, Treponema pallidum, a re-emerging sexually transmitted global pathogen, and West Nile virus, a newly recognized virus in North America.     

Comparative study: conventional cervical and ThinPrep Pap tests in a routine clinical setting.

The conventional Papanicolaou smear is associated with variable false positive and false negative rates, difficulties with interpretation and high unsatisfactory and suboptimal rates. Newer fluid-based methods such as the ThinPrep 2000 system (Cytyc Corp., Boxborough, MA) are said to overcome these difficulties. The aim of this study was to compare the conventional smear with the ThinPrep method in a busy, routine cytology screening laboratory setting. One thousand split samples were evaluated. Using ThinPrep, the results showed an increased sensitivity and a dramatic improvement in specimen adequacy, with a combined 17.2% reduction in 'unsatisfactory' and 'suboptimal' reports. Screening time per slide was also reduced to 3-4 min. In conclusion, we report an increase in sensitivity, a reduction in screening time and a dramatic improvement in specimen adequacy with the ThinPrep method.     

Capturing of cell culture‐derived modified Vaccinia Ankara virus by ion exchange and pseudo‐affinity membrane adsorbers

Smallpox is an acute, highly infectious viral disease unique to humans, and responsible for an estimated 300–500 million deaths in the 20th century. Following successful vaccination campaigns through the 19th and 20th centuries, smallpox was declared eradicated by the World Health Organization in 1980. However, the threat of using smallpox as a biological weapon prompted efforts of some governments to produce smallpox vaccines for emergency preparedness. An additional aspect for the interest in smallpox virus is its potential use as a platform technology for vector vaccines. In particular, the latter requires a high safety level for routine applications. IMVAMUNE®, a third generation smallpox vaccine based on the attenuated Modified Vaccinia Ankara (MVA) virus, demonstrates superior safety compared to earlier generations and represents therefore an interesting choice as viral vector. Current downstream production processes of Vaccinia virus and MVA are mainly based on labor‐intensive centrifugation and filtration methods, requiring expensive nuclease treatment in order to achieve sufficient low host‐cell DNA levels for human vaccines. This study compares different ion exchange and pseudo‐affinity membrane adsorbers (MA) to capture chicken embryo fibroblast cell‐derived MVA‐BN® after cell homogenization and clarification. In parallel, the overall performance of classical bead‐based resin chromatography (Cellufine® sulfate and Toyopearl® AF‐Heparin) was investigated. The two tested pseudo‐affinity MA (i.e., sulfated cellulose and heparin) were superior over the applied ion exchange MA in terms of virus yield and contaminant depletion. Furthermore, studies confirmed an expected increase in productivity resulting from the increased volume throughput of MA compared to classical bead‐based column chromatography methods. Overall virus recovery was ～60% for both pseudo‐affinity MA and the Cellufine® sulfate resin. Depletion of total protein ranged between 86% and 102% for all tested matrices. Remaining dsDNA in the product fraction varied between 24% and 7% for the pseudo‐affinity chromatography materials. Cellufine® sulfate and the reinforced sulfated cellulose MA achieved the lowest dsDNA product contamination. Finally, by a combination of pseudo‐affinity with anion exchange MA a further reduction of host‐cell DNA was achieved. Biotechnol. Bioeng. 2010. 105: 761–769. © 2009 Wiley Periodicals, Inc.