Group Physical Therapy Programs for Military Members With Musculoskeletal Disorders: A Pragmatic Randomized Controlled Trial

OBJECTIVE: To compare the effects of personalized, supervised group-based programs (ie, group physical therapy programs) and usual one-on-one physical therapy care (ie, usual physical therapy care) on disability for military personnel suffering from low back pain, rotator cuff-related shoulder pain, patellofemoral pain syndrome, or lateral ankle sprain. Secondary outcomes were pain severity, pain-related fear, health-related quality of life, and patients' satisfaction with their condition and care. DESIGN: Non-inferiority pragmatic randomized clinical trial. METHODS: One hundred twenty military personnel from the Canadian Armed Forces, experiencing 1 of 4 targeted musculoskeletal disorders, were consecutively recruited and randomly assigned to group physical therapy programs or usual physical therapy care. Disability, pain severity, pain-related fear, and health-related quality-of-life outcomes were measured at 6, 12, and 26 weeks after baseline. Satisfaction with treatment was evaluated at the end of the intervention. Intention-to-treat analyses using linear mixed models with random effects were used to compare the effects of interventions. Chi-square tests were used to compare satisfaction. RESULTS: There were no significant Time × Group interactions for any of the primary and secondary outcomes (Time × Group: P>.67). Satisfaction with treatment also did not differ between groups (P>.05). Statistically significant and clinically important improvements were observed in both groups for all outcomes after 12 weeks (Time effect: P<.01), except for health-related quality of life (P = .13). CONCLUSION: Group physical therapy programs were not inferior to usual physical therapy care for managing pain, functional capacity, and patients' satisfaction with care of military personnel presenting with various musculoskeletal disorders. Both interventions led to clinical and statistical improvement in pain and function in the mid and long term. Group physical therapy could be an effective strategy to enhance access to care. J Orthop Sports Phys Ther 2024;54(6):1-10. Epub 26 Mar 2024. doi:10.2519/jospt.2024.12342.

The effect of a task-specific training on upper limb performance and kinematics while performing a reaching task in a fatigued state

BACKGROUND

Fatigue impacts motor performance and upper limb kinematics. It is of interest to study whether it is possible to minimize the potentially detrimental effects of fatigue with prevention programs.

OBJECTIVE

To determine the effect of task-specific training on upper limb kinematics and motor performance when reaching in a fatigued state.

METHODS

Thirty healthy participants were recruited (Training group n = 15; Control group n = 15). Both groups took part in two evaluation sessions (Day 1 and Day 5) during which they performed a reaching task (as quickly and accurately as possible) in two conditions (rested and fatigued). During the reaching task, joint kinematics and motor performance (accuracy and speed) were evaluated. The Training group participated in three task-specific training sessions between Day 1 and Day 5; they trained once a day, for three days. The Control group did not perform any training. A three-way non-parametric ANOVA for repeated measures (Nonparametric Analysis of Longitudinal Data; NparLD) was used to assess the impact of the training (Condition [within subject]: rested, fatigued; Day [within subject]: Day 1 vs. Day 5 and Group [between subjects]: Training vs. Control).

RESULTS

After the training period, the Training group significantly improved their reaching speed compared to the Control group (Day x Group p < .01; Time effect: Training group = p < .01, Control group p = .20). No between-group difference was observed with respect to accuracy. The Training group showed a reduction in contralateral trunk rotation and lateral trunk flexion in Day 2 under the fatigue condition (Group x Day p < .04; Time effect: Training group = p < .01, Control group = p < .59).

CONCLUSION

After the 3-day training, participants demonstrated improved speed and reduced reliance on trunk compensations to complete the task under fatigue conditions. Task-specific training could help minimizing some effects of fatigue.

Do Exercise Programs Improve Fitness, Mobility, and Functional Capacity in Adults With Lower Limb Amputation? A Systematic Review on the Type and Minimal Dose Needed

OBJECTIVE

To answer the following questions: (1) Do physical activity (PA) and exercise improve fitness, mobility, and functional capacity among adults with lower limb amputation (LLA) and (2) What is the type and minimum dose of PA (frequency, intensity and duration) needed?

DESIGN

Systematic review.

SETTING

Outpatient intervention, outside of the prosthetic rehabilitation phase.

PARTICIPANTS

Adults with lower limb amputation living in the community.

INTERVENTION

Any physical activity or exercise intervention.

OUTCOMES AND MEASURES

Any fitness, mobility, or functional capacity indicators and measurements.

RESULTS

Twenty-three studies were included, totaling 408 adults with LLA. Studies evaluated the effect of structured PA sessions on fitness, mobility, and functional capacity. The highest evidence is for mixed exercise programs, that is, programs combining aerobic exercise with strengthening or balance exercise. There is moderate confidence that 1-3 sessions of 20-60 minutes of exercise per week improves balance, walking speed, walking endurance, and transfer ability in adults with LLA above the ankle. As for flexibility, cardiorespiratory health, lower-limb muscles strength, and functional capacity, there was low confidence that exercise improves these fitness components because of the lack of studies.

CONCLUSION

Exercise 1-3 times per week may improve balance, walking speed, walking endurance, and transfer ability in adults with LLA, especially when combining aerobic exercises with lower limb strengthening or balance exercises. There is a need for most robust studies focusing on the effect of PA on cardiorespiratory health, muscles strength, flexibility, and functional status.

French Version of the Musculoskeletal Pain Intensity and Interference Questionnaire for Professional Orchestra Musicians (MPIIQM-F): Cross-Cultural Adaptation and Preliminary Validation

BACKGROUND

The Musculoskeletal Pain Intensity and Interference Questionnaire for Professional Orchestra Musicians (MPIIQM) is a prominent patient-reported outcome measure (PROM) in the musicians' health literature. It has been published in at least four languages, but not in French.

AIMS

To cross-culturally adapt the MPIIQM into French and establish the preliminary psychometric properties (validity, reliability, and responsiveness) of the MPIIQM-F.

METHODS

Standardized cross-cultural adaptation methods included forward translations, an expert committee, and verbal field tests in the target population. Psychometric properties were assessed in a population of French-speaking professional orchestra musicians who participated in three evaluation sessions. Evaluated properties include content, face, structural and construct validity, reliability (internal consistency, test-retest reliability, minimal detectable change [MDC], measurement error), and responsiveness (effect size and standardized response means [SRM]).

RESULTS

Sixty-one French-speaking orchestra musicians participated in the psychometric validation. Exploratory factor analysis revealed a two-factor solution equivalent to previous versions, confirming the Pain Intensity and Interference subscales. Spearman correlations for construct validity were as hypothesized for four of six hypotheses (minor deviances for the other two hypotheses) using the Brief Pain Inventory, Disability of the Arm, Shoulder and Hand Performing Arts Module, and PROMIS Global Health Scale as comparators. Reliability results demonstrated high internal consistency (Cronbach's a=0.84-0.89), excellent test-retest reliability (intraclass correlation coefficient = 0.91-0.97), and small measurement error with MDC for the overall scale <10%. Responsiveness resulted in moderate to large effect sizes and SRM (0.54-0.87).

CONCLUSIONS

Preliminary validation of the MPIIQM-F suggests good validity, reliability, and responsiveness, indicating its suitability for use in French-speaking orchestra musicians.

Group-based exercice training programs for military members presenting musculoskeletal disorders - protocol for a pragmatic randomized controlled trial

BACKGROUND

Musculoskeletal disorders are a leading cause of morbidity and the most prevalent source of disability among soldiers. Their high prevalence in armed forces and limited ressources have led to problems related to access to physical rehabilitation care. To increase access, supervised group-based exercise programs for the most prevalent musculoskeletal disorders (low back pain, patellofemoral pain, rotator cuff-related shoulder pain or lateral ankle sprain) have been developed at a Canadian Armed forces (CAF) base, but their effectiveness has not been evaluated. The primary objective of this randomized controlled trial is to evaluate the mid- and long-term effects of these group-based training programs on pain severity and functional limitations, in comparison with usual individual physiotherapy care. Secondary objectives include comparing both interventions in terms of health-related quality of life, pain-related fear, and patients' satisfaction.

METHODS

One hundred and twenty soldiers with a new medical referral for physiotherapy services for one of the four targeted musculoskeletal disorders will be consecutively recruited. They will be randomly assigned to either group-based training program or usual individual physiotherapy care, and will take part in the assigned 12-week intervention. There will be four evaluation sessions over 26 weeks (baseline, week 6, 12 and 26). At each follow-up, functional limitations, pain severity, health-related quality of life and pain-related fears will be assessed. Patients satisfaction with treatment will also be evaluated at the end of the intervention period. Either two-way repeated measures ANOVA will be used to analyse and compare the effects of the interventions.

DISCUSSION

This RCT will determine the effectiveness of group-based training programs compared to usual individual physiotherapy care. This new intervention model could represent an efficient, and more pro-active approach to manage a higher number of soldiers with musculoskeletal disorders. It could improve access to physical rehabilitation care and improve the health of soldiers.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT05235152 ), February 11th 2022.

Impact of fatigue at the shoulder on the contralateral upper limb kinematics and performance

Background

Altered movement patterns have been proposed as an etiological factor for the development of musculoskeletal pain. Fatigue influences upper limb kinematics and movement performance which could extend to the contralateral limb and potentially increasing risk of injury. The aim of this study was to investigate the impact of fatigue at the dominant arm on the contralateral upper limb movement.

Methods

Forty participants were randomly assigned to one of two groups: Control or Fatigue Group. All participants completed a reaching task at the baseline and post-experimental phase, during which they reached four targets with their non-dominant arm in a virtual reality environment. Following the baseline phase, the Fatigue Group completed a shoulder fatigue protocol with their dominant arm only, while the Control Group took a 10-minute break. Thereafter, the reaching task was repeated. Upper limb and trunk kinematics (joint angles and excursions), spatiotemporal (speed and accuracy) and surface electromyographic (sEMG) activity (sEMG signal mean epoch amplitude and median frequency of the EMG power spectrum) were collected. Two-way repeated-measures ANOVA were performed to determine the effects of Time, Group and of the interaction between these factors.

Results

There was a significant Time x Group interaction for sternoclavicular elevation range of motion (p = 0.040), movement speed (p = 0.043) and accuracy (p = 0.033). The Fatigue group showed higher contralateral sternoclavicular elevation and increased movement error while experiencing fatigue in the dominant arm. Moreover, the Control group increased their speed during the Post-experimental phase compared to baseline (p = 0.043), while the Fatigue group did not show any speed improvement. There was no EMG sign of fatigue in any of the muscles evaluated.

Conclusion

This study showed that fatigue at the dominant shoulder impacts movement at the contralateral upper limb. Such changes may be a risk factor for the development of shoulder pain in both the fatigued and non-fatigued limbs.

Does musculoskeletal pain interfere with motor learning in a gait adaptation task? A proof-of-concept study

BACKGROUND

Experimental pain during gait has been shown to interfere with learning a new locomotor task. However, very few studies have investigated the impact of clinical pain on motor learning due to the challenges associated with clinical populations.

OBJECTIVE

The first objective of this proof-of-concept study was to determine the feasibility to obtain two groups of participants with chronic ankle pathology with or without residual pain while walking. The second objective was to evaluate the impact of clinical musculoskeletal pain on motor learning during gait.

METHODS

Participants with chronic isolated ankle pathology were recruited and their personal and clinical characteristics were collected (functional performance, dorsiflexion maximal strength, range of motion). To assess motor acquisition (Day 1) and retention (Day 2), participants performed an adaptation task on two consecutive days that consisted of walking while experiencing a perturbing force applied to the ankle. The level of pain during the task was measured, and participants who reported pain were attributed to the Pain group and participants without pain to the No Pain group. Learning performance was assessed by measuring ankle kinematics (Mean plantarflexion absolute error) and learning strategy was assessed by measuring the Relative timing of error and the tibialis anterior (TA) electromyographic activity.

RESULTS

Twenty-five participants took part in the experiment. Eight (32%) were excluded because they could not be included in either the Pain or No Pain group due to the intermittent pain, leaving eight participants in the Pain group and nine in the No Pain group. Both groups were similar in terms of baseline characteristics. Musculoskeletal pain had no influence on learning performance, but the learning strategy were different between the two groups. The No Pain group showed a TA activity reduction before perturbation between the days, while the Pain group did not.

CONCLUSION

Some barriers were identified in studying musculoskeletal pain including the high rates of participants' exclusion, leading to a small sample size. However, we showed that it is feasible to investigate clinical pain and motor learning. From the results of this study, musculoskeletal pain has no influence on motor learning performance but influences the learning strategy.

Strategies to reduce waiting times in outpatient rehabilitation services for adults with physical disabilities: A systematic literature review

Objective

Identifying effective strategies to reduce waiting times is a crucial issue in many areas of health services. Long waiting times for rehabilitation services have been associated with numerous adverse effects in people with disabilities. The main objective of this study was to conduct a systematic literature review to assess the effectiveness of service redesign strategies to reduce waiting times in outpatient rehabilitation services for adults with physical disabilities.

Methods

We conducted a systematic review, searching three databases (MEDLINE, CINAHL and EMBASE) from their inception until May 2021. We identified studies with comparative data evaluating the effect of rehabilitation services redesign strategies on reducing waiting times. The Mixed Methods Appraisal Tool was used to assess the methodological quality of the studies. A narrative synthesis was conducted.

Results

Nineteen articles including various settings and populations met the selection criteria. They covered physiotherapy ( n = 11), occupational therapy ( n = 2), prosthetics ( n = 1), exercise physiology ( n = 1) and multidisciplinary ( n = 4) services. The methodological quality varied ( n = 10 high quality, n = 6 medium, n = 3 low); common flaws being missing information on the pre-redesign setting and characteristics of the populations. Seven articles assessed access processes or referral management strategies (e.g. self-referral), four focused on extending/modifying the roles of service providers (e.g. to triage) and eight changed the model of care delivery (e.g. mode of intervention). The different redesign strategies had positive effects on waiting times in outpatient rehabilitation services.

Conclusions

This review highlights the positive effects of many service redesign strategies. These findings suggest that there are several effective strategies to choose from to reduce waiting times and help better respond to the needs of persons experiencing physical disabilities.

Functional screen of inflammatory bowel disease genes reveals key epithelial functions

BACKGROUND

Genetic studies have been tremendously successful in identifying genomic regions associated with a wide variety of phenotypes, although the success of these studies in identifying causal genes, their variants, and their functional impacts has been more limited.

METHODS

We identified 145 genes from IBD-associated genomic loci having endogenous expression within the intestinal epithelial cell compartment. We evaluated the impact of lentiviral transfer of the open reading frame (ORF) of these IBD genes into the HT-29 intestinal epithelial cell line via transcriptomic analyses. By comparing the genes in which expression was modulated by each ORF, as well as the functions enriched within these gene lists, we identified ORFs with shared impacts and their putative disease-relevant biological functions.

RESULTS

Analysis of the transcriptomic data for cell lines expressing the ORFs for known causal genes such as HNF4a, IFIH1, and SMAD3 identified functions consistent with what is already known for these genes. These analyses also identified two major clusters of genes: Cluster 1 contained the known IBD causal genes IFIH1, SBNO2, NFKB1, and NOD2, as well as genes from other IBD loci (ZFP36L1, IRF1, GIGYF1, OTUD3, AIRE and PITX1), whereas Cluster 2 contained the known causal gene KSR1 and implicated DUSP16 from another IBD locus. Our analyses highlight how multiple IBD gene candidates can impact on epithelial structure and function, including the protection of the mucosa from intestinal microbiota, and demonstrate that DUSP16 acts a regulator of MAPK activity and contributes to mucosal defense, in part via its regulation of the polymeric immunoglobulin receptor, involved in the protection of the intestinal mucosa from enteric microbiota.

CONCLUSIONS

This functional screen, based on expressing IBD genes within an appropriate cellular context, in this instance intestinal epithelial cells, resulted in changes to the cell's transcriptome that are relevant to their endogenous biological function(s). This not only helped in identifying likely causal genes within genetic loci but also provided insight into their biological functions. Furthermore, this work has highlighted the central role of intestinal epithelial cells in IBD pathophysiology, providing a scientific rationale for a drug development strategy that targets epithelial functions in addition to the current therapies targeting immune functions.

The association between running injuries and training parameters: A systematic review

OBJECTIVE

To synthesise the current evidence on the incidence of running-related injuries (RRI) and their association with training parameters (distance, duration, frequency, intensity), as well as recent changes in training parameters.

DATA SOURCES

Searches were conducted in Medline/Ovid, CINAHL, Embase and SportDiscus up to July 7, 2020.

STUDY SELECTION

Included articles had to report prospective data on RRIs and training parameters, or any changes in parameters, and be published in English or French. Two reviewers independently screened titles, abstracts and full-texts.

DATA EXTRACTION

Data extraction and quality assessment (QualSyst) were performed by two independent raters.

DATA SYNTHESIS

Thirty-six articles totaling 23,047 runners were included. Overall, 6,043 runners (26.2%) sustained an RRI (incidence range: 8.8% to 91.3%). The incidence of RRI was 14.9% in novice runners (range: 9.4 to 94.9%), 26.1% in recreational runners (range: 17.9 to 79.3%) and 62.6% in competitive runners (range: 52.6 to 91.3%). The three most frequently injured body parts were the knee (25.8%), foot/ankle (24.4%) and lower leg (24.4%). Overall, there was conflicting evidence about the association between weekly running distance, duration, frequency, intensity or specific changes in training parameters and the onset of RRIs.

CONCLUSIONS

Despite high rates of RRIs, current evidence does not consistently link RRIs with specific training parameters or recent changes in training parameters. Therefore, caution should be taken when recommending optimal parameters or progressions. Given the multifactorial nature of RRIs, future studies also need to consider the interaction between training parameters, as well as psychosocial, hormonal, lifestyle and recovery outcomes to better understand the onset of RRIs.

The impact of experimental pain on shoulder movement during an arm elevated reaching task in a virtual reality environment

BACKGROUND

People with chronic shoulder pain have been shown to present with motor adaptations during arm movements. These adaptations may create abnormal physical stress on shoulder tendons and muscles. However, how and why these adaptations develop from the acute stage of pain is still not well-understood.

OBJECTIVE

To investigate motor adaptations following acute experimental shoulder pain during upper limb reaching.

METHODS

Forty participants were assigned to the Control or Pain group. They completed a task consisting of reaching targets in a virtual reality environment at three time points: (1) baseline (both groups pain-free), (2) experimental phase (Pain group experiencing acute shoulder pain induced by injecting hypertonic saline into subacromial space), and (3) Post experimental phase (both groups pain-free). Electromyographic (EMG) activity, kinematics, and performance data were collected.

RESULTS

The Pain group showed altered movement planning and execution as shown by a significant increased delay to reach muscles EMG peak and a loss of accuracy, compared to controls that have decreased their mean delay to reach muscles peak and improved their movement speed through the phases. The Pain group also showed protective kinematic adaptations using less shoulder elevation and elbow flexion, which persisted when they no longer felt the experimental pain.

CONCLUSION

Acute experimental pain altered movement planning and execution, which affected task performance. Kinematic data also suggest that such adaptations may persist over time, which could explain those observed in chronic pain populations.

Fatigue, induced via repetitive upper-limb motor tasks, influences trunk and shoulder kinematics during an upper limb reaching task in a virtual reality environment

Background

Efficient shoulder movement depends on the ability of central nervous system to integrate sensory information and to create an appropriate motor command. Various daily encountered factors can potentially compromise the execution of the command, such as fatigue. This study explored how fatigue influences shoulder movements during upper limb reaching.

Methods

Forty healthy participants were randomly assigned to one of two groups: Control or Fatigue Group. All participants completed an upper limb reaching task at baseline and post-experimental, during which they reached four targets located at 90° of shoulder abduction, 90° external rotation at 90° abduction, 120° scaption, and 120° flexion in a virtual reality environment. Following the baseline phase, the Fatigue Group completed a shoulder fatigue protocol, while Controls took a 10-minute break. Thereafter, the reaching task was repeated. Upper limb kinematic (joint angles and excursions) and spatiotemporal (speed and accuracy) data were collected during the reaching task. Electromyographic activity of the anterior and middle deltoids were also collected to characterize fatigue. Two-way repeated-measures ANOVA were performed to determine the effects of Time, Group and of the interaction between these factors.

Results

The Fatigue group showed decreased mean median power frequency and increased electromyographic amplitudes of the anterior deltoid (p < 0.05) following the fatigue protocol. Less glenohumeral elevation, increased trunk flexion and rotation and sternoclavicular elevation were also observed in the Fatigue group (Group x Time interaction, p < 0.05). The Control group improved their movement speed and accuracy in post-experimental phase, while the Fatigue group showed a decrease of movement speed and no accuracy improvement (Group x Time interaction, p < 0.05).

Conclusion

In a fatigued state, changes in movement strategy were observed during the reaching task, including increased trunk and sternoclavicular movements and less glenohumeral movement. Performance was altered as shown by the lack of accuracy improvement over time and a decrease in movement speed in the Fatigue group.

Accuracy of examination of the long head of the biceps tendon in the clinical setting: A systematic review

OBJECTIVE

To determine the diagnostic validity of high-resolution ultrasound and orthopaedic special tests in diagnosing long head of the biceps tendon pathologies in patients with shoulder pain.

DESIGN

Systematic review with meta-analysis tools.

DATA SOURCES

MEDLINE, CINAHL and EMBASE.

DATA EXTRACTION

Included studies had to report on the diagnostic validity of orthopaedic special tests or high-resolution ultrasound (HRUS) compared with a reference standard for diagnosing long head of the biceps tendon target conditions (superior labrum anterior and posterior lesions, long head of the biceps tendon tendinopathy, dislocation, effusion or rupture). Risk of bias was assessed using the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2) tool.

RESULTS

Of the 30 included studies, 8 focused on high-resolution ultrasound and 22 on orthopaedic special tests. High-resolution ultrasound proved highly specific for the diagnosis of long head of the biceps tendon pathologies. Pooled positive (LR+) and negative (LR-) likelihood ratios were 38.00 and 0.24 for dislocation, respectively, and 35.50 and 0.30 for complete rupture, respectively. The accuracy of orthopaedic special tests varied greatly across studies. The only test of value was Yergason's ma-noeuvre in confirming proximal long head of the biceps tendon pathologies except superior labrum anterior and posterior lesion (high specificity): the summary LR+ and LR- were 2.56 and 0.70, respectively.

CONCLUSION

High-resolution ultrasound is reliable to confirm suspected long head of the biceps tendon pathologies. There is insufficient evidence to recommend individual orthopaedic special tests.

Cryotherapy or gradual reloading exercises in acute presentations of rotator cuff tendinopathy: a randomised controlled trial

Objectives

Rotator cuff tendinopathies are the most common shoulder disorders. As persistent symptoms lasting more than 3 months have been shown to be a strong indicator of poor outcomes, it is important to have successful interventions in the acute stage. However, there is no evidence yet to guide clinical interventions in an acute pain context. The objective of this study was to compare the short-term effect of a 2-week gradual reloading exercises programme with the use of cryotherapy on symptoms and function for acute rotator cuff tendinopathy.

Methods

This simple-blind, randomised controlled trial included 44 participants with acute rotator cuff tendinopathy who were randomly allocated to either the exercises or cryotherapy group. Symptoms and functional limitations were evaluated at weeks 0, 2 and 6 using self-reported questionnaires (Disabilities of the Arm, Shoulder and Hand, Western Ontario Rotator Cuff, and Brief Pain Inventory), while acromiohumeral distance, shoulder strength and active range of motion were evaluated at weeks 0 and 2.

Results

Following interventions, both groups showed statistically significant improvements on symptoms and function at week 2 and week 6 compared with baseline. However, there was no significant group × time interaction. There was no time effect on acromiohumeral distance, shoulder strength and active range of motion, as well as no time × group interaction.

Conclusion

The results showed a statistically significant improvement in symptoms and function in both groups, but there was no difference between the short-term effect of a cryotherapy based-approach and a gradual reloading exercises programme.

Trial registration number

NCT02813304.

Human Gut Microbiota: Toward an Ecology of Disease

Composed of trillions of individual microbes, the human gut microbiota has adapted to the uniquely diverse environments found in the human intestine. Quickly responding to the variances in the ingested food, the microbiota interacts with the host via reciprocal biochemical signaling to coordinate the exchange of nutrients and proper immune function. Host and microbiota function as a unit which guards its balance against invasion by potential pathogens and which undergoes natural selection. Disturbance of the microbiota composition, or dysbiosis, is often associated with human disease, indicating that, while there seems to be no unique optimal composition of the gut microbiota, a balanced community is crucial for human health. Emerging knowledge of the ecology of the microbiota-host synergy will have an impact on how we implement antibiotic treatment in therapeutics and prophylaxis and how we will consider alternative strategies of global remodeling of the microbiota such as fecal transplants. Here we examine the microbiota-human host relationship from the perspective of the microbial community dynamics.

Membrane-targeted HrpNEa can modulate apple defense gene expression

Fire blight caused by Erwinia amylovora is the major bacterial disease of tribe Maleae, including apple. Among the proteins secreted by this bacterium, HrpNEa, also called harpin, is known to induce hypersensitive response in nonhost plants and to form amyloid oligomers leading to pore opening in the plasma membrane and alteration of membrane homeostasis. To better understand the physiological effects of HrpNEa in the host plant, we produced transgenic apple plants expressing HrpNEa with or without a secretion signal peptide (SP). HrpNEa expressed with a SP was found to be associated within the membrane fraction, in accordance with amyloidogenic properties and the presence of transmembrane domains revealed by in silico analysis. Expression analysis of 28 apple defense-related genes revealed gene modulations in the transgenic line expressing membrane-targeted HrpNEa. While apple transgenic trees displaying a high constitutive expression level of SP-HrpNEa showed a slight reduction of infection frequency after E. amylovora inoculation, there was no decrease in the disease severity. Thus HrpNEa seems to act as an elicitor of host defenses, when localized in the host membrane.

[Which future in cardiovascular therapy for nitric oxide and its derivatives?]

Nitric oxide (NO) is involved in the regulation of several physiological processes such as vascular homeostasis. Exogenous NO supply offers major therapeutic interest, especially in the treatment of coronary artery disease, ischemic syndromes and other cardiovascular pathologies. Nevertheless, the administration of NO itself is limited by its short half-life. NO prodrugs have been marketed for decades, e.g. organic nitrates for angina pectoris. These prodrugs display undeniable advantages such as angina crisis relief and preconditioning effect. Nevertheless, they suffer from several drawbacks: toxicity, tolerance, endothelial dysfunction exacerbation. These negative effects are related to massive production of reactive species derived from oxygen or nitrogen, which trigger oxidative and nitrosative stress. New NO donors are under development to overcome those disadvantages, among which the S-nitrosothiols family seems especially promising.

[Renin-angiotensin-aldosterone system: an old system offering new drug targets for the cerebral circulation]

In a rat model of human essential hypertension (SHR), the chronic increase in cerebral arteriolar blood pressure is accompanied by remodelling with wall hypertrophy and a fall in diameter. The latter produces an increase in cerebrovascular resistance which maintains cerebral blood flow autoregulation at high systemic blood pressure levels, but accentuates hypoperfusion at low arterial pressures such as those observed during and following cerebral ischemia. Using ACE inhibitors and AT1 blockers we have shown that the normalisation of wall thickness is pressure-dependent but that the normalisation of arteriolar diameter relates to a pressure-independent mechanism involving aldosterone. This raises the possibility of new drug targets for arteriolar remodelling involving intracellular sodium-dependent modulation of protein metabolism.

Chitinases of Trichoderma atroviride Induce Scab Resistance and Some Metabolic Changes in Two Cultivars of Apple

ABSTRACT This study reports the combination of a transgene-mediated defense mechanism with a conventionally bred resistance in order to improve apple scab resistance. Two cultivars of apple (Galaxy, scab-susceptible, and Ariane, carrying the Vf resistance gene) were transformed with endochitinase and exochitinase genes derived from the biocontrol fungus Trichoderma atroviride. The obtained transgenic lines were analyzed for the expression of both genes and resistance to two races of the pathogen Venturia inaequalis: the common race 1 and race 6 which overcomes the resistance conferred by the Vf gene. A negative correlation between growth of transgenic lines and endochitinase activity was observed. Reduced growth appeared to be associated with high lignin content and high peroxidase as well as glucanase activity, suggesting that endochitinase activity may disturb the metabolism of the plant. Scab inoculation with races 1 and 6 performed in a growth chamber on 14 lines of normal vigor identified 6 lines with significantly enhanced resistance. Ten lines with reduced vigor were tested in vitro with a bioassay on rooted shoots. All lines expressing high endochitinase activity exhibited a significant reduction of scab symptoms.

Structural features of prions explored by sequence analysis. II. A PrP(Sc) model

Prion diseases are neurodegenerative disorders associated with a conformational conversion of the prion PrP protein, in which the beta strand content increases and that of the a helix decreases. However, the structure of the pathogenous form PrP(Sc), occurring after conformational conversion of the normal cellular form PrP(C), is not yet known. From sequence analysis, we have previously proposed that helix H2 of the prion PrP(C) structure might be a key region for this structural conversion. More recently, we identified the TATA box-binding protein fold as a putative scaffold that may locally satisfy the predicted secondary-structure organisation of PrP(Sc). In the present analysis, we detail the schematic construction of PrP(Sc) monomeric and dimeric models, based on this hypothesis. These models are globally compatible with available data and therefore may provide further insights into the structurally and functionally elusive PrP protein. Some comments are also devoted to a comparison of the yeast Ure2p prion and animal prions.

Structural features of prions explored by sequence analysis I. Sequence data

Animal prion proteins (PrPs) form at the sequence level a very homogenous and 'closed' family. Therefore, few of their structural and functional features can be gleaned from sequence comparison as is now possible on a wide scale for other protein families. To detect putatively related proteins (at the structural and/or functional level), we used a battery of sequence analysis tools. This analysis resulted in (i) the identification of a putative 'prion-like' domain within the envelope of foamy retroviruses, (ii) the detection of putative similarities between prions and an interferon-inducible membrane protein, and (iii) the proposal that of the TATA-box-binding protein is a structural scaffold, which might allow understanding of a key event leading to the structural conversion from PrP(C) (normal cellular prion structure) towards PrP(Sc) (pathogenic structure).

Cerebral arteriolar structure and function in pinealectomized rats

We examined cerebral arteriolar structure and autoregulation of cerebral blood flow (CBF) in control (n = 8), sham-operated (n = 8), pinealectomized (n = 10), and pinealectomized plus melatonin-treated (0.51 +/- 0.01 mg x kg(-1) x day(-1) in drinking water, n = 9) young Wistar rats. The lower limit of CBF autoregulation (LLCBF) was determined by measurement of CBF (in arbitrary units, laser Doppler) during stepwise hypotensive hemorrhage; the arteriolar internal diameter (ID; in microm, cranial window) was also measured. Measurements of ID were repeated during a second stepwise hypotension after smooth muscle cell deactivation (67 mmol/l EDTA). The cross-sectional area (CSA) was measured by histometry. CSA and EDTA-induced vasodilatation decreased after pinealectomy (517 +/- 21 vs. 819 +/- 40 microm(2) in sham and 829 +/- 55 microm(2) in control, P < 0.05, and 81 +/- 4 vs. 102 +/- 5 microm in sham and 104 +/- 4 microm in control, P < 0.05, respectively) and were restored by melatonin (924 +/- 39 microm(2) and 102 +/- 5 microm, respectively). These results suggest that melatonin deprival makes the arteriolar wall thinner and stiffer. However, these changes had little effect on LLCBF. In conclusion, pinealectomy of young rats induces atrophy and decreases distensibility of the cerebral arteriolar wall; these effects are prevented by melatonin. They do not modify LLCBF.

Concussions in athletes produce brain dysfunction as revealed by event-related potentials

We have used event-related potentials (ERP) to assess cerebral activity following mild traumatic brain injuries in 20 college athletes practising contact sports. Concussion victims showed a striking decrease in P300 amplitude, an effect presumed to reflect alterations in attentional-cognitive processes. Moreover, the degree of impairment was strongly related to the severity of post-concussion symptoms. Our data suggest that concussions cause objectively measurable changes in the electrophysiological markers of brain activity and hence in the functions of the structures from which they originate. ERPs may thus constitute a reliable method to accurately monitor the clinical course and recovery of head injuries in athletes.

Effects of lipoxygenase metabolites of arachidonic acid on the growth of human blood CD34(+) progenitors

The influence of lipoxygenase metabolites of arachidonic acid on proliferation and differentiation of CD34(+) cells was studied. Their effects on the CFU-GM and BFU-E progenitors were investigated by culture of CD34(+) cells in liquid or semisolid medium. Only 12-HETE (1 microM) stimulated the [(3)H]thymidine as well as BrdU incorporation and increased the number of cell divisions (PKH2 tracking). Addition of 12-HETE and 15-HETE but not of LXA(4), LXB(4), LTB(4), and LTC(4) to liquid cultures of CD34(+) cells for 3 and 8 days reduced in a time-dependent manner the number of CFU-GM and BFU-E. Both HETEs also increased the percentage of glycophorin A(+) cells while they reduced the percentage of CD34(-)/CD33(+) cells after 3 and 5 days of liquid cultures. These results show that HETE treatment stimulates proliferation and accelerates the differentiation of CD34(+) cells, mostly toward the erythroid lineage.

[Cerebral magnetic resonance imaging (MRI) in the diagnosis of leptomeningeal carcinomatosis in melanoma patients]

OBJECTIVE

Meningeal involvement is frequent in metastatic melanoma, approximately 30% in autopsy series. Functional signs may be misleading and the neurological examination may be normal. Certain diagnosis requires identification of tumor cells in the cerebrospinal fluid. CSF cytology is however sometimes negative and magnetic resonance imaging (MRI) with gadolinium injection may provide the diagnosis. The aim of this retrospective study was to assess the role of imaging in the diagnosis of leptomeningeal carcinomatosis.

PATIENTS AND METHODS

The diagnosis of leptomeningeal carcinomatosis was made in 8 patients between 1992 and 1998. All had signs of neurological function impairment, but the neurology examination was abnormal in only 2.

RESULTS

Cytology examination of the cerebrospinal fluid provided the diagnosis of leptomeningeal carcinomatosis in 5 patients. One out of 5 brain CT scans were positive, showing meningeal enhancement confirmed by brain MRI. The spinal tap was not contributive in 2 cases and was not done in 1. In these three cases, the brain CT did not provide any diagnostic element while the brain MRI with gadolinium injection confirmed the diagnosis of leptomeningeal carcinomatosis.

DISCUSSION

Forty-one percent of patients with autopsy proven leptomeningeal carcinomatosis have a normal ante mortem spinal tap. Brain MRI with gadolinium injection has better sensitivity than brain CT scan. All patients with nonspecific neurological signs and a normal spinal tap should be explored with a brain MRI.

In vivo modifications of AcSDKP metabolism and haematopoiesis in mice treated with 5-fluorouracil and Goralatide

BACKGROUND

The tetrapeptide acetyl-Ser-Asp-Lys-Pro (AcSDKP), a physiological inhibitor of the proliferation of haematopoietic stem cells, is degraded by the angiotensin-I-converting enzyme (ACE). Whereas synthetic AcSDKP (Goralatide) protects normal mice from the haematological toxicity of chemotherapy, it has a lower beneficial effect in humans. This discrepancy could be dependent on Goralatide administration schedules, as well as on the endogenous concentrations of AcSDKP and ACE, which vary during chemotherapy.

METHODS

We investigated the effect of one myelotoxic dose of 5-fluorouracil (5-FU, 200 mg kg-1) administered without or with Goralatide on blood, bone marrow (BM) and spleen AcSDKP concentrations, ACE activity, nucleated cell counts and survival of the primitive haematopoietic progenitors high proliferative potential colony-forming cells (HPP-CFCs).

RESULTS

The 5-FU treatment dramatically decreased the BM concentrations of AcSDKP by 73% and increased the ACE activity in plasma by 50% during the period of active BM regeneration. Repeated injections of Goralatide from 24 h before to 36 h after the i.p. injection of 5-FU spared BM HPP-CFCs. As an injection of 10 mg of Goralatide induced a short peak of plasma AcSDKP without modifying its BM concentrations, we suggest that its protective effect on HPP-CFCs could be mediated by its interference with other plasma molecules targeting to the BM.

CONCLUSION

By improving our knowledge of the biology of AcSDKP in vivo during chemotherapy, our results could help to better define the therapeutic use of Goralatide.

Effects of lipoxygenase metabolites of arachidonic acid on the growth of human mononuclear marrow cells and marrow stromal cell cultures

The effects of various lipoxygenase metabolites of arachidonic acid (AA) were investigated on the growth of freshly isolated human bone marrow mononuclear cells and marrow stromal cell cultures. LTB4, LXA4, LXB4, 12-HETE and 15-HETE (1 microM) decreased [3H]-thymidine incorporation on marrow stromal cell cultures without affecting cell number. Only 12-HETE showed a dose-response effect on [3H]-thymidine incorporation. While LTB4 (1 microM) decreased thymidine incorporation on marrow mononuclear cells, LTC4, LXA4, LXB4, 12-HETE and 15-HETE had no effect. The lipoxygenase inhibitor NDGA had no effect on both cell types suggesting no role of endogenous lipoxygenase metabolites on cell growth. These results suggest no important role of lipoxygenase metabolites of AA on the proliferation of human marrow mononuclear cells and marrow stromal cell cultures.

Effect of platelet-activating factor on the growth of human erythroid and myeloid CD34+ progenitors

We have assessed the effect of platelet-activating factor (PAF), a biologically active phospholipid present in the human marrow, on the growth of human marrow and blood CD34+ progenitors. While the metabolization rate of PAF by CD34+ cells is low (weak acetylhydrolase and acylation processes) it is readily catabolized by the acetylhydrolase activity present in the growth medium (10% fetal calf serum + 10% 5637-conditioned medium). Treatment of marrow CD34+ cells with the non-metabolizable PAF agonist C-PAF (1 nM to 100 nM) immediately before semi-solid culture significantly (P < 0.01) decreased the number of BFU-E but not of CFU-GM colonies. Treatment of marrow or blood CD34+ cells with C-PAF (10-100 nM) for 3 days in liquid medium before semi-solid culture significantly (P < 0.01) decreased the number of BFU-E and CFU-GM colonies. Treatment of blood CD34+ cells with the two PAF receptor antagonists CV 3988 and BN 52021 (1 microM) had no significant effect on the number of BFU-E and CFU-GM colonies suggesting no role of endogenous PAF in these processes. These results show that exogenous PAF downregulates human erythropoiesis and myelopoiesis, a result that might be of importance during inflammatory states.

Production, metabolism and effect of platelet-activating factor on the growth of the human K562 erythroid cell line

The human immature K562 erythroid cell line was studied for its capacity to produce and to metabolize the phospholipid molecule platelet-activating factor (PAF). K562 cells produced PAF under calcium ionophore stimulation. Lyso PAF and acetyl-CoA (the acetate donor molecule for the acetylation of lyso PAF into PAF) had no effect on the amounts of PAF produced by ionophore-stimulated cells. The metabolism of PAF and lyso PAF by K562 cells was compared to that of freshly-isolated human bone marrow erythroblasts and blood erythrocytes. K562 cells rapidly metabolized [3H]PAF and [3H]lyso PAF with 1-alkyl analogue of phosphatidylcholine as the major metabolic product. In contrast, blood erythrocytes did not. PAF acetylhydrolase activity levels in K562 cells and bone marrow erythroblasts were similar and higher than in blood erythrocytes. PAF (1-100 nM) stimulated [3H]thymidine incorporation in K562 cells grown in low serum concentration, a non-metabolizable PAF agonist being more potent than PAF to stimulate thymidine incorporation. PAF receptor mRNA was detected in K562 cells by polymerase chain reaction on reverse transcripts. The present study demonstrates that K562 cells produce and metabolize PAF and underlines the putative role of erythroid precursors in the modulation of bone marrow PAF concentrations. The effect of PAF on the growth of K562 cells might be mediated through PAF receptors suggesting a potential role of PAF on the proliferation and functions of human erythroid marrow precursors.

Effects of lipidic mediators on the growth of human myeloid and erythroid marrow progenitors

Freshly isolated human marrow mononuclear cells produce lipidic compounds such as PAF and leukotrienes. These lipidic molecules act on human marrow myelopoiesis and erythropoiesis by modulating the growth of committed progenitors (CFU-GM and BFU-E) in vitro. Nanomolar concentrations of leukotriene B4 and C4 stimulate the growth of human marrow CFU-GM. In contrast, micromolar concentrations of lipoxygenase inhibitors (NDGA and BW755C) decrease their growth suggesting a role for endogenous lipoxygenase metabolites in this process. Micromolar concentrations of prostaglandin E2 up-regulate and down-regulate the growth of marrow BFU-E and CFU-GM, respectively. In contrast, the other cyclooxygenase metabolites have no effect. Recent studies indicate that nanomolar concentrations of PAF decrease the growth of CFU-GM and BFU-E from purified marrow CD34+ cells. Together these results indicate that lipidic mediators act on human myelopoiesis and erythropoiesis. However at this time the mechanisms and molecular signals mediating the effects of lipidic molecules on human marrow cells are unexplored.

Platelet-activating factor and antagonists modulate DNA synthesis in human bone marrow stromal cell cultures

Platelet-activating factor (PAF) is present in the human bone marrow. We have investigated the effect of PAF and antagonists (BN 52,021 and CV 3988) on the growth of human marrow stromal cells. PAF (1 microM) stimulates and PAF antagonists (0.1-1 microM) inhibit [3H]thymidine incorporation in cells grown in 5% serum. The catabolism of PAF by stromal cells was inhibited by CV 3988 suggesting the presence of specific PAF receptor on cells. PAF and antagonists (0.1 nM-10 microM) had no effect on cells cultured in high serum concentration (20%) or in low serum concentration (1%) with 0.5 ng/ml of basic fibroblast growth factor (bFGF). This study indicates for the first time that PAF modulates the serum-induced but not the bFGF-induced growth of marrow stromal cells. The interactions between PAF and stromal cells during inflammatory marrow events such as myelofibrosis deserve to be assessed.

Presence and metabolism of lyso platelet-activating factor in human bone marrow

Lyso platelet-activating factor (PAF) is the precursor of PAF, an inflammatory phospholipid molecule present in human bone marrow. The present study shows that in healthy volunteers lyso PAF concentrations are significantly lower (P = 0.0001, Mann-Whitney U-test) in bone marrow plasma (594 +/- 67 ng/ml, n = 47) than in blood plasma (1448 +/- 99 ng/ml, n = 31). Marrow plasma lyso PAF concentrations are similar in patients with lymphoid and nonlymphoid malignancies as compared with controls. Freshly isolated mononuclear marrow cells and cultures of marrow stromal cells contain lyso PAF. Experiments with [3H]lyso PAF indicate that human mononuclear bone marrow cells and marrow stromal cells actively acylate lyso PAF into a 1-alkyl analogue of phosphatidylcholine. Results of this investigation indicate: (1) that lyso PAF is present in human marrow cells and plasma; and (2) that marrow cells and stromal cells metabolize it, thus suggesting their role in the regulation of lyso PAF amounts in human bone marrow.

Production and metabolism of platelet-activating factor by human bone marrow cells

Platelet-activating factor (PAF) is a phospholipid mediator of inflammation present in the human bone marrow. Freshly isolated human mononuclear bone marrow cells and marrow stromal cell cultures produced PAF under calcium ionophore (2 microM) and LPS (10 micrograms/ml) stimulation. By contrast, M-CSF (1000 U/ml), GM-CSF (100 ng/ml), IL1, IL3, IL6 and stem cell factor (10 ng/ml) did not stimulate PAF production. Marrow stromal cells produced 50-fold more PAF than freshly isolated mononuclear marrow cells, suggesting that stromal cells might be the major source of the human marrow-derived PAF. Mononuclear marrow cells and stromal cell cultures metabolized PAF with 1-alkyl-2-acyl-glycerophosphocholine as the major metabolic product. PMSF and p-BPB decreased the catabolism of PAF by freshly isolated marrow cells, but not by stromal cell cultures. While stromal cells rather than haematopoietic progenitors might be a major source of the human bone-marrow-derived PAF, both cell types metabolize it, suggesting their putative role in the regulation of PAF concentration in the human bone marrow.

PAF and haematopoiesis: IX. Platelet-activating factor increases DNA synthesis in human bone marrow cells

Platelet-activating factor (PAF) is present in human bone marrow leading us to investigate its effect on human bone marrow cell proliferation. While PAF (0.1 microM to 1 nM) stimulates the incorporation of [3H]thymidine by freshly isolated adherent human bone marrow cells, PAF has no effect on non adherent cells. A non-metabolizable PAF agonist is more potent than PAF to stimulate thymidine incorporation in adherent cells. The precise role of PAF in human haematopoiesis in vivo remains to be clarified.

PAF and haematopoiesis XII: macrophage colony-stimulating factor (M-CSF) decreases platelet-activating factor (PAF) acetylhydrolase production in macrophagic J774 cells

Platelet-activating factor (PAF) is a phospholipid mediator with major immunoregulatory activities. Macrophages produce PAF acetylhydrolase activity, which regulates blood PAF concentrations. Macrophage colony-stimulating factor (M-CSF) is involved in the differentiation and functions of cells from the monocytic/macrophagic lineage. We found that murine macrophagic J774 cells metabolized PAF with lyso PAF as the major metabolite product. As in mouse plasma, the metabolism of PAF by J774 cells was not inhibited by PMSF, p-BPB, DTNB and quinacrine, M-CSF (100-5000 U/ml) significantly decreased PAF acetylhydrolase activity of the J774 cell without exhibiting a significant effect on cell growth. Elevated concentrations of M-CSF are found in blood and tissues during inflammatory states. It could be suggested that a decreased PAF catabolism by tissue macrophages in response to M-CSF may induce local elevated PAF concentrations, thus amplifying the inflammatory response.