Primary prevention of food allergy in 2021: Update and proposals of French-speaking pediatric allergists

During the past years, there has been an alarming increase in cases of food allergy and anaphylaxis in ever-younger children. Often, these children have multiple food allergies and food sensitizations, involving allergens with high anaphylactic potential, such as peanuts and nuts, which have a major influence on their quality of life and future. After reviewing the current epidemiological data, we discuss the main causes of the increase in food allergies. We analyze data from studies on the skin barrier and its fundamental role in the development of sensitization and food allergies, data on the tolerogenic digestive tract applied in particular to hen eggs and peanuts, as well as data on the prevention of allergy to cow milk proteins. In light of these studies, we propose a practical guide of recommendations focused on infants and the introduction of cow milk, the management of eczema, and early and broad dietary diversification including high-risk food allergens, such as peanut and nuts while taking into account the food consumption habits of the family.

Long-term morbidity and mortality in 2-year hepatoblastoma survivors treated with SIOPEL risk-adapted strategies

BACKGROUND AND AIMS

Prognosis of hepatoblastoma patients has increased with cisplatin-based chemotherapy and high-quality resection including liver transplant. Consequently current risk-adapted therapeutic strategy aims to reduce long-term side effects in patients with standard risk disease.

METHODS

We report long-term mortality and morbidity data concerning 151 2-year hepatoblastoma survivors treated with SIOPEL risk-adapted strategies (sex-ratio M/F = 1.6, median age at diagnosis = 2.6 years [range 0-17.7], median year at diagnosis = 2008 [1994-2017]). Fifty-three patients had loco-regional risk factors VPEFR, 12 were PRETEXT-IV and 30 were metastatic. All received cisplatin and 84 anthracyclines. Twelve had liver transplant. To assess hearing, renal and cardiac functions, audiograms were performed in 116/151 patients (76.8%), glomerular filtration rate in 113/151 (74.8%) and cardiac ultrasound in 65/84 (77.4%) anthracycline-exposed patients.

RESULTS

With a median follow-up of 9.4 years (range 2.1-25.8), four late relapses, one second malignancy (Acute Myeloid Leukemia AML-M5) and two deaths (one from hepatoblastoma, one from AML) occurred. The 10-years event free survival and overall survival probabilities were 95.5% (95% CI 91.9-99.1) and 98.7% (95% CI 96.8-100), respectively. Sixty-eight non-oncologic health-events included 57 cases of hearing loss (including 25 Brock 3-4), three liver cirrhosis, three pre-operative portal cavernoma, two focal nodular hyperplasia, two grade-1 chronic kidney diseases and one asymptomatic cardiac dysfunction were reported. Ototoxicity was significantly associated with cisplatin cumulative dose (OR = 2.07, 95% CI 1.32-3.24, p = 0.001) and carboplatin exposure (OR = 3.14, 95% CI 1.30-7.58, p = 0.01) in multivariable analysis adjusted for sex and age at diagnosis.

CONCLUSIONS

With current risk-adapted strategies, hepatoblastoma is a highly curable disease, with very rare relapses, and few late effects except hearing loss which remains a serious condition in these very young patients.

Towards a European health research and innovation cloud (HRIC)

The European Union (EU) initiative on the Digital Transformation of Health and Care (Digicare) aims to provide the conditions necessary for building a secure, flexible, and decentralized digital health infrastructure. Creating a European Health Research and Innovation Cloud (HRIC) within this environment should enable data sharing and analysis for health research across the EU, in compliance with data protection legislation while preserving the full trust of the participants. Such a HRIC should learn from and build on existing data infrastructures, integrate best practices, and focus on the concrete needs of the community in terms of technologies, governance, management, regulation, and ethics requirements. Here, we describe the vision and expected benefits of digital data sharing in health research activities and present a roadmap that fosters the opportunities while answering the challenges of implementing a HRIC. For this, we put forward five specific recommendations and action points to ensure that a European HRIC: i) is built on established standards and guidelines, providing cloud technologies through an open and decentralized infrastructure; ii) is developed and certified to the highest standards of interoperability and data security that can be trusted by all stakeholders; iii) is supported by a robust ethical and legal framework that is compliant with the EU General Data Protection Regulation (GDPR); iv) establishes a proper environment for the training of new generations of data and medical scientists; and v) stimulates research and innovation in transnational collaborations through public and private initiatives and partnerships funded by the EU through Horizon 2020 and Horizon Europe.

A machine-learning method for classifying and analyzing foot placement: Application to manual material handling

Foot placement strategy is an essential aspect in the study of movement involving full body displacement. To get beyond a qualitative analysis, this paper provides a foot placement classification and analysis method that can be used in sports, rehabilitation or ergonomics. The method is based on machine learning using a weighted k-nearest neighbors algorithm. The learning phase is performed by an observer who classifies a set of trials. The algorithm then automatically reproduces this classification on subsequent sets. The method also provides detailed analysis of foot placement strategy, such as estimating the average foot placements for each class or visualizing the variability of strategies. An example of applying the method to a manual material handling task demonstrates its usefulness. During the lifting phase, the foot placements were classified into four groups: front, contralateral foot behind, ipsilateral foot behind, and parallel. The accuracy of the classification, assessed with a holdout method, is about 97%. In this example, the classification method makes it possible to observe and analyze the handler's foot placement strategies with regards to the performed task.

Validation of a low-cost inertial motion capture system for whole-body motion analysis

While some low-cost inertial motion capture (IMC) systems are now commercially available, generally, they have not been evaluated against gold standard optical motion capture (OMC). The objective was to validate the low-cost Neuron IMC system with OMC. Whole-body kinematics were recorded on five healthy subjects during manual handling of boxes for about 32 min while wearing 17 magnetic and inertial measurement units with Optotrak clusters serving as a reference. The kinematical model was calibrated anatomically for OMC and with poses for IMC. Local coordinate systems were aligned with angular velocities to dissociate differences due to technology or kinematical model. Descriptive statistics including the root mean square error (RMSE), coefficient of multiple correlation (CMC) and limits of agreement (LoA) were applied to the joint angle curves. The average technological error yielded 5.8° and 4.9° for RMSE, 0.87 and 0.96 for CMC and 0.4 ± 8.6° and -0.3 ± 6.0° for LoA about the frontal and transverse axes respectively, whereas the longitudinal axis yielded 10.5° for RMSE, 0.78 for CMC and 3.3 ± 13.1° for LoA. Differences due to technology and to the model contributed similarly to the total difference between IMC and OMC. For many joints and axes, RMSE stayed under 5°, CMC over 0.9 and LoA under 10°, especially for the transverse axis and lower limb. The Neuron low-cost IMC system showed potential for tracking complex human movements of long duration in a normal laboratory environment with a certain error level that may be suitable for many applications involving large IMC distribution.

Influence of soil type on TiO2 nanoparticle fate in an agro-ecosystem

Nanoparticles (NPs) and in particular TiO₂-NPs are increasingly included in commercial goods leading to their accumulation in sewage sludge which is spread on agricultural soils as fertilizers in many countries. Crop plants are thus a very likely point of entry for NPs in the food chain up to humans. So far, soil influence on NP fate has been under-investigated. In this article, we studied the partitioning of TiO₂-NPs between soil and soil leachate, their uptake and biotransformation in wheat seedlings and their impact on plant development after exposure on 4 different types of soil with different characteristics: soil texture (from sandy to clayey), soil pH, cationic exchange capacity, organic matter content. Results suggest that a NP contamination occurring on agricultural soils will mainly lead to NP accumulation in soil (increase of Ti concentration up to 302% in sand) but to low to negligible transfer to soil leachate and plant shoot. In our experimental conditions, no sign of acute phytotoxicity has been detected (growth, biomass, chlorophyll content). Clay content above 6% together with organic matter content above 1.5% lead to translocation factor from soil to plant leaves below 2.5% (i.e. below 13mgTi·kg^-1 dry leaves). Taken together, our results suggest low risk of crop contamination in an agro-ecosystem.

Long-term outcome of liver transplantation in childhood: A study of 20-year survivors

We report the results of a study of survival, liver and kidney functions, and growth with a median follow-up of 24 years following liver transplantation in childhood. From 1988 to 1993, 128 children underwent deceased donor liver transplantation (median age: 2.5 years). Twenty-year patient and graft survival rates were 79% and 64%, respectively. Raised serum aminotransferase and/or γ-glutamyl transferase activities were present in 42% of survivors after a single transplantation. Graft histology (35 patients) showed signs of chronic rejection in 11 and biliary obstruction in 5. Mean total fibrosis scores were 4.5/9 and 3/9 in patients with abnormal and normal serum liver tests, respectively. Glomerular filtration rate was <90 mL·min^-1 in 35 survivors, including 4 in end-stage renal disease who were undergoing dialysis or had undergone renal transplantation. Median final heights were 159 cm for women and 172 cm for men; final height was below the target height in 37 patients. Twenty-year survival after childhood liver transplantation may be close to 80%, and final height is within the normal range for most patients. However, chronic kidney disease or altered liver biochemistries are present in over one third of patients, which is a matter of concern for the future.

3D knife-edge characterization of two-photon absorption volume in silicon for integrated circuit testing

We have performed three-dimensional characterization of the TPA effective laser spot size in silicon using an integrated knife-edge sensor. The TPA-induced response of a CMOS integrated circuit is analyzed based on these results and compared to simulation; we have found that the charge injection capacity in IC's active layer could be influenced by irradiance energy and focus depth.

Prevalence and correlates of seclusion with or without restraint in a Canadian psychiatric hospital: a 2-year retrospective audit

Seclusion with or without restraint is a measure used to manage patients with challenging behaviours. Although controversial, the intervention remains poorly documented, especially in Canadian psychiatric hospitals. The purpose of this study is to assess the prevalence of the measure and identify any correlated demographic characteristics and psychiatric disorders. Episodes of seclusion with or without restraint were extracted from a computerized, hospital-based system introduced specifically to track such interventions. Of 2721 patients hospitalized during that time, 23.2% (n = 632) were secluded with or without restraint, and 17.5% (n = 476) were secluded with restraint. Younger age, schizophrenia or other psychosis, bipolar and personality disorder, and longer stay in hospital are predictors of an episode of seclusion with or without restraint. Younger age, bipolar and personality disorders and a longer stay in hospital are predictors of an episode of seclusion with restraint. For patients who spent longer in seclusion and under restraint, there is a positive association with longer stay in hospital. In this inpatient psychiatric facility, seclusion with or without restraint thus appears to be common. More research is warranted to better identify the principal factors associated with seclusion and restraint and help reduce resort to these measures.

Factors influencing decisions on seclusion and restraint

Seclusion with or without restraint is a measure for managing aggressive or agitated clients and promoting site security, particularly in an emergency psychiatric setting. The decision to control a potentially dangerous person's behaviour by removal or seclusion seems ethically justifiable in such a setting. However, although the decisions on these restrictive measures are based on rational needs, they are also influenced by the healthcare team's perceptions of the client and by the characteristics of the team and the environment. The purpose of this paper is to set out and categorize the factors in play in aggression- and agitation-management situations as perceived by the healthcare teams, particularly the nurses. The first part of the paper deals briefly with the settings in which control measures are applied in a province in eastern Canada and the effect of such measures on patients and healthcare teams. The second part identifies the factors involved in the management of agitation and aggression behaviour. The final part discusses the current spin-offs from this knowledge as well as promising paths for further research on the factors involved. The ultimate objective is to reduce recourse to coercive measures and enhance professional practices.

Evaluation of a hybrid system for three-dimensional measurement of trunk posture in motion

Ambulatory assessment of trunk posture is important in improving our understanding of the risk of low back injury. Recently, small inertial sensors combining accelerometers, gyroscopes and magnetometers were developed and appear to be promising for measuring human movement. However, the validity of such sensors for assessing three-dimensional (3D) trunk posture in motion has not been documented. The purpose of this study was to evaluate a hybrid system (HS) composed of two inertial sensors for the 3D measurement of trunk posture. A secondary purpose was to explore the utility of adding another source of information, a potentiometer, to measure the relative rotation between both sensors in order to improve the validity of the system. The first sensor was placed over the sacrum and the second on the upper part of the thorax. Both sensors were linked by a flexible rod with a potentiometer. A complementary quaternion filter algorithm was used to estimate trunk orientation by taking advantage of the nine components of each sensor and the potentiometer. The HS's orientations were compared to those obtained from a 3D optoelectronic system. Validation of the HS was performed in three steps in which six subjects had to perform manual handling tasks in: (1) static postures; (2) dynamic motions of short duration (30s); and (3) dynamic motions of long duration (30min). The results showed that the root mean square (RMS) error of the HS was generally below 3 degrees for the flexion and lateral bending axes, and less than 6 degrees for the torsion axis, and that this error was lower for the short-duration tests compared to the long-duration one. The potentiometer proved to be an essential addition, particularly when the magnetometer signals were corrupted and only the gyroscope and accelerometer could be combined. It is concluded that the HS can be a useful tool for quantifying 3D trunk posture in motion.

Expression of IgH chain genes in antibody response to ragweed and purified Amb a 1: evidence for differential regulation of isotype production

A survey of the work with Ig response to allergens carried out previously reveals an allergen-specific response both by IgE and all of IgG subclasses. Response of non-sensitive people is characterized by the appearance of a variety of the IgG subclasses. We have reexamined ragweed and Amb a 1 specific Ig response in 54 nonsensitive and 147 atopic or atopic-allergic people using a new inverse sandwich immunoassay allowing discrimination based on antibody affinity. We show that non-sensitive people present no, 0 out of 54, Ig response with affinities higher than Ka 10(7) M(-1). The subpopulation of 66 atopics who never have experienced desensitization responds vigorously and solely (56 out of 66) with genes of the sequence gamma2-alpha2. Only ten showed an additional weak response from gamma1-alpha1. This suggests a possible association between the atopic state and selective activation of part of the gene sequence.

Determination of cardiac troponin I forms in the blood of patients with acute myocardial infarction and patients receiving crystalloid or cold blood cardioplegia

To determine the forms of cardiac troponin I (cTnI) circulating in the bloodstream of patients with acute myocardial infarction (AMI) and patients receiving a cardioplegia during heart surgery, we developed three immunoenzymatic sandwich assays. The first assay involves the combination of two monoclonal antibodies (mAbs) specific for human cTnI. The second assay involves the combination of a mAb specific for troponin C (TnC) and an anti-cTnI mAb. The third assay was a combination of a mAb specific for human cardiac troponin T (cTnT) and an anti-cTnI mAb. Fifteen serum samples from patients with AMI, 10 serum samples from patients receiving crystalloid cardioplegia during heart surgery, and 10 serum samples from patients receiving cold blood cardioplegia during heart surgery were assayed by the three two-site immunoassays. We confirmed that cTnI circulates not only in free form but also complexed with the other troponin components (TnC and cTnT). We showed that the predominant form in blood is the cTnI-TnC binary complex (IC). Free cTnI, the cTnI-cTnT binary complex, and the cTnT-cTnI-TnC ternary complex were seldom present, and when present, were in small quantities compared with the binary complex IC. Similar results were obtained in both patient populations studied. These observations are essential for the development of new immunoassays with improved clinical sensitivity and for the selection of an appropriate cTnI primary calibrator.

Antigenic definition of cardiac troponin I

The presence of cardiac troponin I in the serum is now considered as one of the most specific biochemical markers of acute myocardial infarction. To improve the knowledge of the antigenic properties of cardiac Troponin I, a set of monoclonal antibodies and polyclonal antibodies against human cardiac troponin I has been tested with overlapping peptides covering the cardiac troponin I sequence. The results indicate that N-terminal and C-terminal cardiac troponin I regions were most often recognized by poly- and monoclonal antibodies. These observations are valuable for choosing the best combination of monoclonal antibodies to set up new immunoassays to detect serum cardiac troponin I earlier after myocardial damage, to understand better which forms are released, and finally to propose appropriate cardiac troponin I standards.

Human cardiac troponin I: precise identification of antigenic epitopes and prediction of secondary structure

The presence of human cardiac troponin I (hcTnI) in serum is considered to be a highly specific biochemical marker of acute myocardial infarction. To better understand the antigenic properties of hcTnI, a set of 68 overlapping peptides covering the complete amino acid sequence of hcTnI was prepared and used in epitope mapping experiments. All 16 anti-hcTnI monoclonal antibodies tested were found to recognize a peptide epitope, indicating that recognition by anti-hcTnI monoclonal antibodies was not dependent on the tertiary structure of the protein. Furthermore, the peptide reactivity with anti-hcTnI polyclonal antibodies indicated that most of the sequence of the protein was antigenic; in particular, the N- and C-terminal extremities were found to be the strongest antigenic regions. By using accurate secondary structure prediction methods, hcTnI was found to be an all-alpha type protein, with five regions predicted as helices. Matching the results of the epitope analysis with the structural prediction led us to the view that hcTnI is not a globular protein but probably adopts an extended conformation, allowing a large part of the amino acid sequence of this molecule to be recognized by the immune system. This improved knowledge of the antigenic and structural properties of hcTnI may help in developing new antibodies and immunoassays for use in diagnosing myocardial infarction.

Breakdown and release of myofilament proteins during ischemia and ischemia/reperfusion in rat hearts: identification of degradation products and effects on the pCa-force relation

Our objective in experiments reported here was to identify myofilament proteins of rat hearts either lost or degraded by cardiac ischemia (15- or 60-minute duration) with and without 45 minutes of reperfusion. We correlated these changes with alterations in myofilament sensitivity to Ca2+ and maximum force generation. Protein degradation and loss were assessed by high-performance liquid chromatography, SDS-PAGE, Western blotting analysis, and amino acid sequencing. Compared with nonischemic control hearts, bundles of skinned fibers from hearts subjected to ischemia alone demonstrated a decrease in maximum force generation and an increase in sensitivity to Ca2+. These changes in function were increased with the duration of the ischemia and with reperfusion. With increasing duration of ischemia, there was an increased loss and degradation of myofibrillar alpha-actinin and troponin I (TnI) at its C-terminus. Alpha-actinin and TnI were most susceptible to ischemia, but with 60 minutes of ischemia/reperfusion, there was also degradation of myosin light chain-1 (MLC1) involving a clip of residues 1 to 19. The MLC1 degradation product was detected in the reperfusion effluent (along with troponin T, tropomyosin, and alpha-actinin) but not in the tissue with 60 minutes of ischemia with no reperfusion. Moreover, with ischemia the following proteins became associated with the myofibrils: GAPDH and proteins of the mitochondrial ATP synthase complex. Our results provide new evidence regarding the mechanism by which ischemia/reperfusion causes myocardial injury and support the hypothesis that an important element in the injury is altered activity and structure of the myofilaments.

Cardiac troponin I to diagnose percutaneous transluminal coronary angioplasty-related myocardial injury

The purposes of the present study were to evaluate cardiac troponin 1 (cTnl) in the diagnosis of percutaneous transluminal coronary angioplasty (PTCA)-related myocardial injury in comparison with cardiac troponin T (cTnT) and creatine kinase (CK) MB mass concentration, and to investigate the frequency of myocardial injury, as indicated by myocardial protein release, after clinically symptomless side-branch occlusion (SBO) which may occur in the proximity of the attempted stenosis. The final study population comprised 80 patients undergoing elective, single vessel PTCA. Blood samples were drawn before, 6, 24 and 48 h after PTCA. cTnI, cTnT and CKMB mass baseline values were within the reference intervals in all patients (cTnI < 0.1 microgram/l, cTnT < 0.2 microgram/l, CKMB < 5 micrograms/l). Two patients presented with primary failure of PTCA, and visually successful PTCA was performed in all remaining patients. Seven patients (four with SBO) subsequently developed acute myocardial infarction (AMI). Symptomless SBO occurred in 16 patients. In controls (n = 55) there were no significant increases in cTnI, cTnT, or CKMB concentrations compared with baseline values, and all markers stayed within their reference intervals. In half the patients with symptomless SBO (n = 8) all markers were slightly to moderately increased, in two additional patients only CKMB was elevated (cTnI: 0.1-1.0 microgram/l; cTnT: 0.25-0.81 microgram/l and CKMB: 7.9-25.6 micrograms/l). In the majority of patients with primary failure or AMI we found pronounced increases in all tested markers (cTnI: 0.2-12.0 micrograms/l; cTnT: 0.44-12.10 micrograms/l; CKMB: 19.2-423.0 micrograms/l). The results of this study indicate that cTnI is comparably useful to cTnT or CKMB mass for diagnosing myocardial injury in PTCA patients. From our results a preference for one of the tested parameters cannot be clearly derived. Post-procedural cTnI, cTnT, and CKMB mass values are not higher than baseline values in uncomplicated cases, whereas AMI after PTCA leads to pronounced marker increases. SBO, even when symptomless, leads frequently (in about half the patients) to slight marker increases.

Release kinetics of serum cardiac troponin I in ischemic myocardial injury

OBJECTIVES

The study was undertaken to evaluate the release kinetics of cardiac troponin I (cTn-I) in ischemic myocardial injury.

DESIGN AND METHODS

The reference range for cTn-I was established by determination of cTn-I in sera and plasma obtained from 622 healthy volunteers (Group 1). cTn-I was compared to: (a) Creatine kinase (CK) MB mass and myoglobin in 12 patients with severe skeletal muscle damage (Group 2); (b) CK-MB activity in 48 patients with myocardial infarction (MI) receiving intravenous thrombolysis (Group 3) (in this group, an additional 43 patients with MI were analyzed separately to characterize cTn-I patterns in thrombolyzed and nonthrombolyzed populations): and in 44 patients with unstable angina (Group 4).

RESULTS

In Groups 1 and 2, no positive results (> or = 0.1 microgram/L) were obtained. In Group 3, the time-courses of cTn-I were mostly monophasic in form. A pathologic increase occurred earlier in cTn-I than in CK-MB activity (p = 0.0002); the period with increased cTn-I was longer (p = 0.001), the overall sensitivity of cTn-I (93.9%) was higher than that of CK-MB activity (p = 0.00001). cTn-I was more sensitive at admission (p = 0.0004). In additional patients, the cTn-I peak occurred and cTn-I disappeared significantly later in nonthrombolyzed than in the thrombolyzed group. In Group 4, positive tests results were detected in 45% of patients for cTn-I, 16% for CK-MB activity, and 32% for CK-MB mass.

CONCLUSIONS

The cTn-I assay appears to be ideally suited for the detection of ischemic myocardial injury in complex clinical situations because of its high specificity; cTn-I indicates myocardial tissue damage in patients with unstable angina and is superior to CK-MB activity and mass in this respect.

Cardiac troponin I in the diagnosis of myocardial injury and infarction

We used a cardiospecific enzymoimmunometric assay to measure cardiac troponin I (cTnI) in samples serially drawn from 78 patients with acute myocardial infarction (AMI), 7 patients with unstable angina (Braunwald class III), 22 multi-traumatized patients, and in 30 athletes after eccentric exercise, as well as in 101 non-traumatic chest pain patients on admission to the emergency department. cTnI assay crossreactivity with crude human skeletal muscle homogenates was < 0.1%. cTnI could not be detected in athletes or multi-traumatized patients except for 2 trauma patients with myocardial damage. Increased cTnI concentrations were found in 6 of 7 patients with unstable angina at rest and in all AMI patients. After AMI, cTnI increased about 3.5 h (median) after the onset of chest pain, reached peak values parallel to CKMB, and stayed increased for at least 4 days. Cardiac troponin T (cTnT) increased and mostly peaked parallel to cTnI. cTnT sensitivity on the 7th day after AMI was significantly higher than that of cTnI. In contrast to cTnI, cTnT mostly showed a second, usually smaller, peak about day 4 after AMI. During the first 4 h after the onset of chest pain and before thrombolytic therapy the sensitivities of myoglobin (0.43) and CKMB mass (0.56) were significantly higher than those of both troponins (cTnI, 0.29; cTnT, 0.25). Areas under receiver operator characteristic curves indicated only moderate diagnostic accuracies of bio-chemical markers for early AMI diagnosis in non-traumatic chest pain patients that cTnI is a highly sensitive and specific marker for myocardial damage which is suitable for early and late diagnosis.

[Value of human cardiac troponin I determination in the diagnosis of acute myocardial infarction]

Immunoenzymatic assay (IEMA) of human cardiac Troponin I (TnI c) was used in patients admitted to the coronary care unit with acute myocardial infarction (AMI). TnI c was detected in all patients with AMI. The detection of TnI c was earlier after the onset of pain (4.5 +/- 2.3 hours) than that of CKMB activity (6.3 +/- 3.6 hours), p = 0.003. The kinetics of TnI c are usually monophasic and parallel to that of CKMB activity. The peak value occurs 12.2 +/- 4.6 hours and 15.8 +/- 9.0 hours after the onset of pain in patients treated by thrombolysis. The TnI c disappears from the plasma between 5 and 9 days after the onset of pain, later than CKMB activity (p = 0.0001). In 49 patients admitted for AMI treated by thrombolysis, the comparative sensitivities of TnI c (threshold: 0.1 ng/ml) and of CKMB activity (threshold: 15 IU/l; CK > or = 100 Ul/l) were, at the first sampling on admission, 61% and 22% respectively (p = 0.0002) (average interval from onset of pain to first blood sampling: 3.4 +/- 1.3 hours). TnI c was not detected in the plasma of 145 normal subjects nor in any of the 6 patients with severe muscular trauma or rhabdomyolosis (specificity: 100%). This IEMA is a specific and a sensitive method of diagnosing acute and subacute myocardial infarction. It is ideal for the detection of myocardial necrosis in complex clinical situations when the usual enzymatic markers may be ineffective.

Cardiac troponin I release correlates with myocardial infarction size

Cardiac troponin I, creatine kinase, and creatine kinase MB activity were tested in serial blood samples from 15 patients with first-time Q wave acute myocardial infarction (2 anterior and 13 inferior wall infarctions). All patients received intravenous thrombolytic therapy. Cardiac troponin I and creatine kinase MB activity were compared with scintigraphic estimates of myocardial scar (single photon emission computed tomography [SPECT] with 99mTechnetium-isonitrile [Tc-sestamibi]) on late images at rest about 5 weeks after myocardial infarction. Scintigraphic defect sizes ranged from 3.2 to 41.2% (median: 27.3%) of left ventricle. Cardiac troponin I increased and peaked in parallel with creatine kinase MB activity, and the peak values correlated with each other (r = 0.76, p = 0.002). Troponin I stayed increased for several days longer than creatine kinase and creatine kinase MB activity. It could be detected at least until the 4th day after admission. Significant correlation coefficients were found between 99mTc-isonitrile defect sizes and areas under cardiac troponin I curves (r = 0.53, p = 0.042) and between 99mTc-isonitrile defect sizes and cumulative creatine kinase MB activity release (r = 0.64, p = 0.01). Animal studies have already shown a very close correlation between histologic infarct size and SPECT 99mTc-isonitrile defect size. Therefore, our results indicate that cardiac troponin I release in patients with acute myocardial infarction is also correlated with infarct size.

Rapid adaptation to eccentric exercise-induced muscle damage

This study examined eccentric exercise-induced muscle damage and rapid adaptation. Twenty-two male subjects performed 70 eccentric actions with the knee extensors. Group A (n = 11) and group B (n = 11) repeated the same exercise 4 and 13 days after the initial bout, respectively. Criterion measures included muscle soreness, muscle force generation (vertical jump height on a Kistler platform), and plasma levels of creatine kinase (CK), slow-twitch skeletal (cardiac beta-type) myosin heavy chains (MHC), and cardiac troponin I. Subjects were tested pre-exercise and up to day 4 following each bout. The initial exercise resulted in an increase in CK and MHC, a decrement in muscle force, and delayed onset muscle soreness in all participants. CK and MHC release correlated closely (rho = 0.73, p = 0.0001), both did not correlate with the decrement in muscle force generation after exercise. Because cardiac troponin I could not be detected in all samples, which excluded a protein release from the heart (cardiac beta-type MHC), this finding provides evidence for a injury of slow-twitch skeletal muscle fibers in response to eccentric contractions. Repetition of the initial eccentric exercise bout after 13 days (group B) did not cause muscle soreness, a decrement in muscle reaction force with vertical jump or significant changes in plasma MHC and CK concentrations, whereas in case of repetition after 4 days (group A) only the significant increases in CK and MHC were abolished. The decrement in reaction force with vertical jump did not differ significantly from that after the initial exercise session, but perceived muscle soreness was less pronounced.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of cardiac troponin I to diagnose perioperative myocardial infarction in coronary artery bypass grafting

Cardiac troponin I (cTnI) is a regulatory protein unique to myocardium. We used a cardiospecific 30-min ELISA to measure cTnI in EDTA-plasma samples serially drawn from 28 patients before and after coronary artery bypass grafting (CABG)--26 elective and 2 salvage cases. The cTnI increase in 22 of the elective CABG patients, who did not have perioperative myocardial infarction (not-PMI), reflected the inevitable myocardial damage caused by cannulation and cardioplegic arrest, with peak values of 1.7 +/- 1.0 microgram/L (mean + 2 SD = 3.7 micrograms/L), the peaks occurring on average 8 h (range 4-24) after aortic unclamping. Two of the 22 not-PMI, elective CABG patients showed cTnI peaks &gt; 3.0 micrograms/L (3.9 and 3.4 micrograms/L), indicating more extensive perioperative myocardial damage than the other 20, as confirmed by clinical and electrocardiographic or echocardiographic signs, although creatine kinase isoenzyme MB (CKMB) activity was below our PMI decision limit of 20 U/L (25 degrees C). As classified by electrocardiography, echocardiography, and increased CKMB activity, four of the 26 elective CABG patients did have a PMI. One patient with Q-wave PMI had peak cTnI approximately 30 micrograms/L, and three with non-Q-wave PMI had lower peak values (approximately 5 micrograms/L). The two salvage CABG cases had increased cTnI before surgery. One developed a Q-wave acute myocardial infarction with a 3-h cTnI peak of approximately 35 micrograms/L. We conclude that, after elective CABG, cTnI peaks &gt; 3.7 micrograms/L and concentrations &gt; 3.1 micrograms/L at 12 h or 2.5 micrograms/L at 24 h indicate PMI with high probability.

Use of cardiac troponin I to diagnose perioperative myocardial infarction in coronary artery bypass grafting

Cardiac troponin I (cTnI) is a regulatory protein unique to myocardium. We used a cardiospecific 30-min ELISA to measure cTnI in EDTA-plasma samples serially drawn from 28 patients before and after coronary artery bypass grafting (CABG)--26 elective and 2 salvage cases. The cTnI increase in 22 of the elective CABG patients, who did not have perioperative myocardial infarction (not-PMI), reflected the inevitable myocardial damage caused by cannulation and cardioplegic arrest, with peak values of 1.7 +/- 1.0 microgram/L (mean + 2 SD = 3.7 micrograms/L), the peaks occurring on average 8 h (range 4-24) after aortic unclamping. Two of the 22 not-PMI, elective CABG patients showed cTnI peaks > 3.0 micrograms/L (3.9 and 3.4 micrograms/L), indicating more extensive perioperative myocardial damage than the other 20, as confirmed by clinical and electrocardiographic or echocardiographic signs, although creatine kinase isoenzyme MB (CKMB) activity was below our PMI decision limit of 20 U/L (25 degrees C). As classified by electrocardiography, echocardiography, and increased CKMB activity, four of the 26 elective CABG patients did have a PMI. One patient with Q-wave PMI had peak cTnI approximately 30 micrograms/L, and three with non-Q-wave PMI had lower peak values (approximately 5 micrograms/L). The two salvage CABG cases had increased cTnI before surgery. One developed a Q-wave acute myocardial infarction with a 3-h cTnI peak of approximately 35 micrograms/L. We conclude that, after elective CABG, cTnI peaks > 3.7 micrograms/L and concentrations > 3.1 micrograms/L at 12 h or 2.5 micrograms/L at 24 h indicate PMI with high probability.

Participation in workplace design with reference to low back pain: a case for the improvement of the police patrol car

Thirty Canadian police officers, divided into six groups, participated in the redesign of the interior of the patrol car. Three of the groups consisted of individuals having a history of low back disease. The effect of participating in a design process on the characteristics of the final design and on the perception of the low back pain was studied in a semi-experimental setting. The participants developed a strong commitment to the participatory design process, which was reflected in their productions. The differences between participants with and without a history of a low back disease was not marked. The former tended to stress posture-related elements in their analysis and design.

Ergonomics aspects of tree-planting using 'multipot' technology

The highlights of a descriptive study on the ergonomics and occupational health and safety aspects of tree-planting in Québec are presented. The study was planned to consider the most representative geographical sites, planting technologies, and planting organizations. Semi-directed interviews were made with a mixed group of 48 male and female tree-planters and physiological measurements were made on four male planters. Tools and other equipment were also examined. An analysis of the work identified the main elements of the planting cycle, and the high cardiac rate in the working planters was related more to his manual transportation of seedlings and travel on rough paths than to planting per se. A tree-planter will typically travel 2.4 km carrying 16.8 kg of material and equipment in order to plant an average of 1245 seedlings daily. One out of two interviewed planters reported having a work-related accident or incident during his or her lifetime planting career. The body parts reported most frequently injured were the lower extremities (knee, foot, ankle), the skin, the eyes, and the wrist. Recommendations on the development of appropriate tools and footwear for tree-planters and for further research on repetitive strain injury induced by tree-planting have been made.

Cardiac-specific immunoenzymometric assay of troponin I in the early phase of acute myocardial infarction

The screening by immunoenzymometric assay (IEMA) of 784 monoclonal antibody (MAb) combinations resulted in the selection of an optimal pair of MAbs for measuring human cardiac troponin I (TnI). Using a one-step IEMA described here, we were able to detect TnI within the range of 0.2-20 micrograms/L in 30 min at room temperature. No cross-reactivity was observed with the skeletal isoforms of troponin up to a concentration of 500 micrograms/L. This assay was used to measure cardiac TnI in the plasma of 43 patients with acute myocardial infarction (AMI). TnI was detected relatively early after the onset of chest pain (4.3 +/- 2.1 h, mean +/- SD); the peak occurred after 12.2 +/- 4.6 h in a population that had undergone fibrinolysis. TnI disappearance was generally observed between 5 and 9 days after the onset of chest pain. No cardiac TnI could be detected in 145 healthy donors or in a control group of 6 patients (with skeletal damage or rhabdomyolysis). This assay allows a specific diagnosis of AMI in its early acute phase, with a high diagnostic specificity and sensitivity.

Cardiac-specific immunoenzymometric assay of troponin I in the early phase of acute myocardial infarction

The screening by immunoenzymometric assay (IEMA) of 784 monoclonal antibody (MAb) combinations resulted in the selection of an optimal pair of MAbs for measuring human cardiac troponin I (TnI). Using a one-step IEMA described here, we were able to detect TnI within the range of 0.2-20 micrograms/L in 30 min at room temperature. No cross-reactivity was observed with the skeletal isoforms of troponin up to a concentration of 500 micrograms/L. This assay was used to measure cardiac TnI in the plasma of 43 patients with acute myocardial infarction (AMI). TnI was detected relatively early after the onset of chest pain (4.3 +/- 2.1 h, mean +/- SD); the peak occurred after 12.2 +/- 4.6 h in a population that had undergone fibrinolysis. TnI disappearance was generally observed between 5 and 9 days after the onset of chest pain. No cardiac TnI could be detected in 145 healthy donors or in a control group of 6 patients (with skeletal damage or rhabdomyolysis). This assay allows a specific diagnosis of AMI in its early acute phase, with a high diagnostic specificity and sensitivity.

[Evaluation of the size of thrombolysed myocardial infarction by serum myosin determination]

The prognosis of myocardial infarction is very dependent on the size of the infarct. The measurement of the infarct size after thrombolysis remains difficult despite the large number of methods available, all of which have drawbacks. This parameter is however essential to assess prognosis and the efficacy of thrombolytic therapy. Serum beta heavy chain myosin determination is a recently introduced method of evaluating infarct size; there are relatively few published studies, especially concerning post-thrombolytic patients. A prospective study was undertaken in 40 patients (37 men and 3 women: average age 55.6 years) with a primary myocardial infarction treated by thrombolysis. Myosin levels (peak and area under curve of 5 samples in 10 days) were compared with other methods of assessing infarct size: electrocardiogram (number of leads with Q waves, ST segment analysis), cardiac enzymes (peak and release integrals of CK abd LDH), contrast ventriculography (segmental asynergy score, ejection fraction), coronary angiography and resting MIBI myocardial scintigraphy. The peak and integral of myosin release correlated well with the other methods (p < 0.01): a correlation was particularly apparent between the integral of myosin release and MIBI scintigraphy scores (r = 0.77, p < 0.001). Complex myosin release kinetics were observed significantly more often in patients with large infarcts (p < 0.01) or in those with occlusion of the artery responsible for infarction at coronary angiography on the 6th day (p = 0.001). In conclusion, with 5 blood samples over a 10 day period, it is possible to estimate the infarct size after thrombolysis in everyday cardiological practice: this method could help identify high risk subjects (complex kinetics of myosin release and high peak myosin levels) and also could be used to assess efficacy of thrombolytic therapy in large scale trials.

New monoclonal antibodies as probes for human cardiac troponin I: epitopic analysis with synthetic peptides

Forty monoclonal antibodies (MAbs) specific for human cardiac troponin I (TnI) were selected to develop a new alternative for specific biological diagnosis of acute myocardial infarction. Using an immunoenzymatic sandwich assay, these MAbs were employed in the mapping of human cardiac TnI and showed six different epitopes. Parts of the TnI peptide sequences were synthesised; the sequences were chosen from the published sequences of mammalian TnI. Immunological assays showed that 8 out of 40 MAbs recognised a RAYATEPHAK (P2) N-terminus cardiac-specific sequence of human TnI. The information obtained from epitopic mapping of TnI and the properties of the peptides allowed pairs of MAbs to be selected for the development of a future specific TnI assay.

Imaging of myocardial infarction in dogs and humans using monoclonal antibodies specific for human myosin heavy chains

The use of three different monoclonal antibodies specific for human ventricular myosin heavy chains in the visualization of the location and extent of necrosis in dogs with experimental acute myocardial infarction and in humans is described. Using a classic immunohistochemical method or ex vivo analysis of heart slices in dogs with acute myocardial infarction subjected to intravenous injection of unlabeled antimyosin antibodies or antimyosin antibodies labeled with indium-111, it was observed that all antibody fragments specifically reached the targeted necrotic zone less than 2 h after antibody injection and remained bound for up to 24 h. In a limited but significant number of cases (5 of the 12 humans and 11 of 43 dogs), it was possible to image the necrotic zone in vivo as early as 2 to 4 h after antibody injection. In other cases, individual blood clearance variations retarded or even prevented in vivo necrosis detection. Higher antimyosin fixation values were obtained in the necrotic zones in dogs with a rapid blood clearance relative to that of the other dogs. It is concluded that antimyosin antibodies always reached necrotic areas within 2 h. If blood clearance was rapid, in vivo imaging of the necrotic area was possible 2 to 6 h after necrosis, even in humans. In some cases, however, uncontrolled individual variations in the timing required for sufficient blood clearance hampered this rapid in vivo detection of myocardial necrosis.

Immunoradiometric assay of myosin heavy chain fragments in plasma for investigation of myocardial infarction

Estimation of the extent and location of infarct is important for the prognosis and hence therapeutic strategy in patients with acute myocardial infarction (AMI). Because cardiac myosin is the major structural protein of the myocardium, and may thus reflect the extent of injured tissue, we established a new sensitive immunoradiometric assay, using a pair of monoclonal antibodies (Mabs) that specifically bind the myosin heavy chain fragments liberated from the myocyte into plasma after a heart attack. A first Mab is linked to a magnetic solid phase. A second Mab, radiolabeled with 125I, is used to detect myosin trapped on the solid phase by the first Mab during a 3-h incubation. This assay can detect 10 micro-units of myosin per liter and is highly reproducible.

Assay of serum cardiac myosin heavy chain fragments in patients with acute myocardial infarction: determination of infarct size and long-term follow-up

To evaluate the correlation between myosin heavy chain release and the necrosis mass, serum levels of myosin heavy chain fragments were determined serially in 55 patients with acute myocardial infarction. Eight of these patients were successfully treated with thrombolytic agents: the others were not treated. The same myosin titration was applied to the sera of 25 dogs with an experimental myocardial infarction. Six of the dogs were successfully treated with thrombolytic agents. The time courses of the myosin concentrations are typical and monophasic for all patients with a noncomplex myocardial infarction. The values for the kinetic parameters of myosin release are comparable to those previously reported. We have now determined that cumulative myosin release significantly correlates with cumulative creatine kinase (CK), CK-MB, and lactate dehydrogenase release, as well as with thallium-201 distribution, as determined for different patient groups. Thrombolytic treatment does not seem to qualitatively upset myosin kinetics. The results obtained in dogs with or without thrombolysis conclusively indicate that myosin release is a quantitative index of the necrosis mass. From a practical point of view, a few serial determinations of serum levels of myosin heavy chains are enough to estimate the necrosed mass in patients with acute myocardial infarction. More generally, serum myosin titration could be useful in detecting any cardiac disturbance involving myocardial injury resulting in membrane leakage of cardiac cells.

Myosin: a highly sensitive indicator of myocardial necrosis after cardiac operations

Plasma levels of ventricular myosin fragments, determined with monoclonal antibodies to myosin heavy chains, were studied in 27 patients after cardiac operations (17 aorta-coronary bypass grafts and 10 valve replacements) to assess their possible role as a marker of perioperative myocardial necrosis. Five patients had perioperative myocardial necrosis after aorta-coronary bypass grafts as indicated by changes in the electrocardiogram and elevated levels of the MB isoenzyme of creatine kinase. Six more patients were also studied after thoracic operations performed by the same sternotomy approach. After cardiac operations, myosin levels increased from postoperative day 3 and reached peak values on day 7. Peak myosin values in patients with perioperative myocardial necrosis after aorta-coronary bypass grafting were significantly higher than in patients after an identical operation but without perioperative myocardial infarction (3793 +/- 592 versus 369 +/- 47 ng/ml; p less than 0.001). These results suggest that plasma myosin is a sensitive marker of myocardial necrosis. Furthermore, peak plasma levels of ventricular myosin after coronary bypass grafting without myocardial infarction (mean value 369 +/- 47 ng/ml) were not significantly different from peak levels after thoracic operations (mean value 253 +/- 52 ng/ml), whereas they were significantly higher after valve replacement (mean value 794 +/- 149 ng/ml; p less than 0.01). These results indicate that a certain degree of myocardial necrosis occurs during value replacement that is undetectable by the usual diagnostic criteria for perioperative myocardial infarction. We conclude that the plasma level of ventricular myosin fragments is a more specific and accurate marker of perioperative myocardial necrosis than changes in the electrocardiogram or elevated creatine kinase MB levels. Therefore the detection of myosin fragments, which appear in the serum on the third day after cardiac operations, may be useful for precise comparisons of different techniques of myocardial protection.

An extracorporeal hollow-fiber reactor for phenylketonuria using immobilized phenylalanine ammonia lyase

A hollow-fiber hemodialyzer with immobilized phenylalanine ammonia lyase was tested in vitro for depletion of blood phenylalanine in a recirculating system. A sustained reduction of phenylalanine was obtained in less than 1 h. The product of phenylalanine deamination, trans-cinnamic acid, is a nontoxic compound metabolized to benzoic acid by the liver and eliminated in the urine as hippuric acid. As a model, this reactor may be relevant not only for the short-term management of hyperphenylalaninemia (particularly in pregnant phenylketonuric mothers), but for other metabolic diseases as well, provided that a biocatalyst effective on the accumulating substance is available.

Suitable hollow fibre immunobioreactors for specific ex vivo removal of antibodies and antigens from plasma

Studies were undertaken to determine the applicability and effectiveness of a new immunoadsorbent, constituted of cellulose hollow fibres chemically modified (BrCN) to link selected proteins. The method has been assayed on a simple model of antibody elimination: myeloma IgG or BSA as antigens were covalently linked to cellulose; such an immunoadsorbent can selectively and efficiently deplete circulating antibodies in vitro and ex vivo (on immunized dogs) from whole blood, without releasing linked protein into the hosts' circulation. The original approach of using this method to remove antibodies has been extended to specifically remove antigens (for this purpose, antibodies were conjugated to cellulose), in order to investigate an immunoadsorption therapy in familial hypercholesterolemia, characterized by a plasmatic overload of low-density-lipoproteins (LDL), of which apolipoprotein B is the major protein. After covalent linkage of isolated anti-apolipoprotein B antibodies to cellulose, human plasma LDL levels were effectively and specifically reduced by this procedure.