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.

Considerations for upscaling individual effects of wind energy development towards population-level impacts on wildlife

The expansion of wind energy poses challenges to policy- and decision-makers to address conflicts with wildlife. Conflicts are associated with impacts of existing and planned projects on wildlife, and associated difficulties of prediction where impacts are subject to considerable uncertainty. Many post-construction studies have demonstrated adverse effects on individuals of various bird and bat species. These effects may come in the form of collision-induced mortality or behavioral or physiological changes reducing the fitness of individuals exposed to wind energy facilities. Upscaling these individual effects to population impacts provides information on the true value of interest from a conservation point of view. This paper identifies methodological issues associated when moving from individual effects to population impacts in the context of wind energy. Distinct methodological approaches to predict population impacts are described using published case studies. The various choices of study design and metrics available to detect significant changes at the population level are further assessed based on these. Ways to derive impact thresholds relevant for decision-making are discussed in detail. Robust monitoring schemes and sophisticated modelling techniques may inevitably be unable to describe the whole complexity of wind and wildlife interactions and the natural variability of animal populations. Still, they will provide an improved understanding of the response of wildlife to wind energy and better-informed policies to support risk-based decision-making. Policies that support the use of adaptive management will promote assessments at the population level. Providing information to adequately balance the development of wind energy with the persistence of wildlife populations.

The nucleoside analog GS-441524 strongly inhibits feline infectious peritonitis (FIP) virus in tissue culture and experimental cat infection studies

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GS-441524 inhibited replication of serotype II FIP virus (FIPV) in CRFK cell cultures at an EC50 of approximately 1 uM and no toxicity at 100 uM.

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GS-441524 inhibited wildtype FIPV replication in macrophage cultures from ascitic fluid of two cats with naturally occurring FIP.

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GS-441525 is triphosphorylated by CRFK cells in vitro and PBMC in vivo.

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Pharmacokinetic studies in laboratory cats demonstrated effective blood levels over 24 h after a single dose of 5 mg/kg SC or IV.

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Severe experimental effusive FIP was successfully treated with 2 or 5 mg/kg GS-441524 SC q24 h for two weeks.

Feline infectious peritonitis (FIP) is a common and highly lethal coronavirus disease of domestic cats. Recent studies of diseases caused by several RNA viruses in people and other species indicate that antiviral therapy may be effective against FIP in cats. The small molecule nucleoside analog GS-441524 is a molecular precursor to a pharmacologically active nucleoside triphosphate molecule. These analogs act as an alternative substrate and RNA-chain terminator of viral RNA dependent RNA polymerase. We determined that GS-441524 was non-toxic in feline cells at concentrations as high as 100 uM and effectively inhibited FIPV replication in cultured CRFK cells and in naturally infected feline peritoneal macrophages at concentrations as low as 1 uM. We determined the pharmacokinetics of GS-441524 in cats in vivo and established a dosage that would sustain effective blood levels for 24 h. In an experimental FIPV infection of cats, GS-441524 treatment caused a rapid reversal of disease signs and return to normality with as little as two weeks of treatment in 10/10 cats and with no apparent toxicity.

The use of the Duchenne marker and symmetry of the expression in the judgment of smiles in schizophrenia

Research has recurrently shown that individuals with schizophrenia have impairments in emotional facial recognition and this deficit has been associated with aberrant visual scanning of the face. Because human beings have the ability to control the expression of emotion, the communication process becomes more complex. The goal of the current study was to conduct a systematic examination of the response pattern and perceptual-attentional processing in distinguishing smiles with the presence and absence of the Duchenne marker and symmetry and asymmetry of the activation in individuals with schizophrenia. Sixteen individuals diagnosed with schizophrenia and 16 control individuals were asked to judge whether the smiles were really happy or not. Individuals with schizophrenia produced fewer expected responses than controls in judging the symmetric non-Duchenne smile as not really happy. In addition, like their healthy counterparts, individuals with schizophrenia showed difficulty with the judgement of asymmetric Duchenne smiles. In addition to not being as sensitive to the cues, individuals with schizophrenia show differences in their viewing patterns. While the current study does not provide clear links between these viewing patterns and judgment responses, future research should explore other explanations, such as explicit knowledge, for the differences in results.

Distinction between fear and surprise: an interpretation-independent test of the perceptual-attentional limitation hypothesis

The perceptual-attentional limitation hypothesis posits that the confusion between emotional facial expressions of fear and surprise may be due to their visual similarity, with shared muscle movements. In Experiment 1 full face images of fear and surprise varying as a function of distinctiveness (mouth index, brow index, or both indices) were displayed in a gender oddball task. Experiment 2, in a similar task, directed attention toward the eye or mouth region with a blurring technique. The current two studies used response time and event-related potentials (ERP) to test the perceptual-attentional limitation hypothesis. While ERP results for Experiment 1 suggested that individuals may not have perceived a difference between the emotional expressions in any of the conditions, response time results suggested that individuals processed a difference between fear and surprise when a distinctive cue was in the mouth. With directed attention in Experiment 2, ERP results indicated that individuals were capable of detecting a difference in all the conditions. In effect, the current two experiments suggest that participants display difficulty in distinguishing the prototypes of fear and surprise with the eye region, which may be due to a lack of attention to that region, providing support for the attentional limitation hypothesis.

Visceral fat enhances blood pressure reactivity to physical but not mental challenges in male adolescents

BACKGROUND

Excess visceral fat is a major risk factor for hypertension. Enhanced blood pressure (BP) reactivity and delayed BP recovery from physical and mental challenges predict future hypertension.

OBJECTIVES

Determine whether visceral fat is associated with higher BP reactivity and delayed BP recovery from physical and mental challenges during adolescence.

METHODS

In a community-based sample of 283 male and 308 female adolescents, we measured visceral fat with magnetic resonance imaging, total body fat with bioimpedance, and beat-by-beat BP with a Finometer at rest and during physical (10-min standing) and mental (2-min math stress) challenges.

RESULTS

Males vs. females showed greater BP reactivity and no differences in BP recovery from either type of challenges. Visceral fat was positively associated with BP reactivity to standing up only and in males only (+8.4 ± 3.6 mmHg per 1 log cm(3) of visceral fat, P = 0.008), and this association was independent of total body fat. No association was seen between visceral fat and BP recovery from either type of challenge in either sex. All these associations were independent of age, puberty stage, height and initial BP.

CONCLUSIONS

Adolescent males vs. females demonstrate greater BP reactivity but similar BP recovery from physical and mental challenges. Excess visceral fat enhances BP reactivity to physical but not mental challenges in males only.

The Confusion of Fear and Surprise: A Developmental Study of the Perceptual-Attentional Limitation Hypothesis Using Eye Movements

The goal of the present study was to test the Perceptual-Attentional Limitation Hypothesis in children and adults by manipulating the distinctiveness between expressions and recording eye movements. Children 3-5 and 9-11 years old as well as adults were presented pairs of expressions and required to identify a target emotion. Children 3-5 years old were less accurate than those 9-11 years old and adults. All children viewed pictures longer than adults but did not spend more time attending to the relevant cues. For all participants, accuracy for the recognition of fear was lower than for surprise when the distinctive cue was in the brow only. They also took longer and spent more time in both the mouth and brow zones than when a cue was in the mouth or both areas. Adults and children 9-11 years old made more comparisons between the expressions when fear comprised a single distinctive cue in the brow than when the distinctive cue was in the mouth only or when both cues were present. Children 3-5 years old made more comparisons for brow only than both. The results of the present study extend on the Perceptual-Attentional Limitation Hypothesis showing an importance of both decoder and stimuli, and an interaction between decoder and stimuli characteristics.

Confusion of fear and surprise: a test of the perceptual-attentional limitation hypothesis with eye movement monitoring

Of the basic emotional facial expressions, fear is typically less accurately recognised as a result of being confused with surprise. According to the perceptual-attentional limitation hypothesis, the difficulty in recognising fear could be attributed to the similar visual configuration with surprise. In effect, they share more muscle movements than they possess distinctive ones. The main goal of the current study was to test the perceptual-attentional limitation hypothesis in the recognition of fear and surprise using eye movement recording and by manipulating the distinctiveness between expressions. Results revealed that when the brow lowerer is the only distinctive feature between expressions, accuracy is lower, participants spend more time looking at stimuli and they make more comparisons between expressions than when stimuli include the lip stretcher. These results not only support the perceptual-attentional limitation hypothesis but extend its definition by suggesting that it is not solely the number of distinctive features that is important but also their qualitative value.

Analysis of eye movements in the judgment of enjoyment and non-enjoyment smiles

Enjoyment smiles are more often associated with the simultaneous presence of the Cheek raiser and Lip corner puller action units, and these units' activation is more often symmetric. Research on the judgment of smiles indicated that individuals are sensitive to these types of indices, but it also suggested that their ability to perceive these specific indices might be limited. The goal of the current study was to examine perceptual-attentional processing of smiles by using eye movement recording in a smile judgment task. Participants were presented with three types of smiles: a symmetric Duchenne, a non-Duchenne, and an asymmetric smile. Results revealed that the Duchenne smiles were judged happier than those with characteristics of non-enjoyment. Asymmetric smiles were also judged happier than the non-Duchenne smiles. Participants were as effective in judging the latter smiles as not really happy as they were in judging the symmetric Duchenne smiles as happy. Furthermore, they did not spend more time looking at the eyes or mouth regardless of types of smiles. While participants made more saccades between each side of the face for the asymmetric smiles than the symmetric ones, they judged the asymmetric smiles more often as really happy than not really happy. Thus, processing of these indices do not seem limited to perceptual-attentional difficulties as reflected in viewing behavior.

Clinical and genetic knowledge and attitudes of patients with myotonic dystrophy type 1

AIMS

The goal was to assess clinical and genetic knowledge and attitudes in patients affected by myotonic dystrophy type 1 (DM1).

METHODS

Two hundred patients with molecular confirmation of the diagnosis of DM1 completed a multi-choice questionnaire. DM1 patients' knowledge and views were compared to clinically normal DM1 noncarriers (n = 264) and controls (n = 1,474).

RESULTS

Knowledge of the DM1 mode of inheritance was better in noncarriers than in patients (p < 0.001). Noncarriers were more aware than DM1 patients of the common clinical characteristics of DM1 such as limitations in physical activities and problems related to employment, schooling, activities of daily living, parenthood, peer relationships, and personality (p < 0.001). Compared to controls, DM1 patients felt less informed about the availability of clinical genetic services (p < 0.05) and new genetic technologies (p < 0.001). Among patients, logistic regression revealed that each additional year of education (p < 0.05) and each additional 100 CTG repeats (p < 0.01), respectively, increased and decreased the odds of knowing the DM1 mode of inheritance by about 23% and 18% respectively, independently of age, age at onset of symptoms, gender, severity of muscular impairment, and intellectual quotient.

CONCLUSIONS

DM1 patients' genetic knowledge is significantly dependent of the level of education and the number of CTG repeats. Healthcare providers should be aware of this situation in order to adjust counselling and education accordingly.

A decade of mammalian retinal stem cell research

Ten years have now passed since the discovery of quiescent neural stem cells within the mammalian retina. Beside the fascinating aspect of stem cell biology in basic science, these cells have also offered hope for the treatment of incurable retinal diseases. The field has thus rapidly evolved, fluctuating between major advances and recurring doubts. In this review, we will retrace the efforts of scientists during this last decade to characterize these cells and to use them in regenerative medicine. We will also highlight advances made in animal models capable of stem cell-mediated retinal regeneration.

Sexual dimorphism in the adolescent brain: Role of testosterone and androgen receptor in global and local volumes of grey and white matter

Here we examined sex differences in the volumes of grey and white matter, and in grey-matter "density," in a group of typically developing adolescents participating in the Saguenay Youth Study (n=419; 12-18 years). In male adolescents, we also investigated the role of a functional polymorphism in androgen-receptor gene (AR) in moderating the effect of testosterone on volumes of grey and white matter and grey-matter density. Overall, both absolute and relative volumes of white matter were larger in male vs. females adolescents. The relative grey-matter volumes were slightly larger in female than male adolescents and so was the grey-matter density in a large number of cortical regions. In male adolescents, functional polymorphism of AR moderated the effect of testosterone on relative white- and grey-matter volumes. Following a discussion of several methodological and interpretational issues, we outline future directions in investigating brain-behavior relationships vis-à-vis psychopathology.

Sex differences in the growth of white matter during adolescence

The purpose of this study was to examine sex differences in the maturation of white matter during adolescence (12 to 18 years of age). We measured lobular volumes of white matter and white-matter "density" throughout the brain using T1-weighted images, and estimated the myelination index using magnetisation-transfer ratio (MTR). In male adolescents, we observed age-related increases in white-matter lobular volumes accompanied by decreases in the lobular values of white-matter MTR. White-matter density in the putative cortico-spinal tract (pCST) decreased with age. In female adolescents, on the other hand, we found only small age-related increase in white-matter volumes and no age-related changes in white-matter MTR, with the exception of the frontal lobe where MTR increased. White-matter density in the pCST also increased with age. These results suggest that sex-specific mechanisms may underlie the growth of white matter during adolescence. We speculate that these mechanisms involve primarily age-related increases in axonal calibre in males and increased myelination in females.

Maternal cigarette smoking during pregnancy and cognitive performance in adolescence

BACKGROUND

The incidence of cigarette smoking during pregnancy remains high. Maternal smoking during pregnancy is known to be associated with cognitive and behavioural sequelae in childhood and adolescence. We assessed the relationship between maternal cigarette smoking during pregnancy and cognitive abilities in adolescent offspring (n = 503, 12- to 18-years old) using an extensive 6-h battery of tests.

METHODS

Non-exposed adolescents (controls) were matched to exposed adolescents (cases) by maternal education and school attended. Cognitive abilities were evaluated using a neuropsychological battery consisting of 33 tasks measuring verbal abilities, visuo-spatial skills, verbal and visual memory, processing speed, resistance to interference and motor dexterity.

RESULTS

We found no differences between cases and controls in any of the cognitive domains whether potential confounders were included in the model or not. In addition to maternal smoking during pregnancy, we also evaluated the effect of sex and age on the various cognitive abilities in this large adolescent sample and found that most of the abilities continue to improve during adolescence to the same extent in girls and boys, with several age-independent sex differences.

CONCLUSIONS

We found no effect of maternal cigarette smoking during pregnancy on cognitive abilities of the adolescent offspring when matching cases and controls by maternal education, the most common confounder of maternal cigarette smoking during pregnancy.

Reducing the harm of "harm reduction"

The article in this issue by Alan Leshner tackles one of the most contentious issues in drug use policy today and argues that we should dispense with "harm reduction" altogether--not the programs, policies, and interventions to which this term refers but the term itself. He makes the case that the initial clarity and simplicity of the phrase "harm reduction" have evolved into an emotion-laden designation that is interfering with the implementation and evaluation of public health programs.

Corpus callosum in adolescent offspring exposed prenatally to maternal cigarette smoking

Teratogens, such as alcohol or anti-epileptic drugs, affect the size of the corpus callosum. Here we report findings obtained in a case-control study that investigated possible effects of teratogens contained in cigarette smoke on the size and structural properties of this structure. We recruited and scanned with magnetic resonance imaging a total of 408 adolescents (12 to 18 years of age); a subsample of 300 adolescents is considered in this report. Cases (n=146) were exposed to maternal cigarette smoking during pregnancy; non-exposed controls (n=154) were matched to cases by maternal education. We measured the size of corpus callosum (CC) and its sections (corrected for brain size), as well as mean values of magnetization-transfer ratio (MTR) in each CC section. Corpus callosum, and especially its posterior part, was smaller in the exposed vs. non-exposed female adolescents; no significant effects were found in males. Exposed and non-exposed subjects did not differ in the MTR-based index of myelination in either gender in any CC section. Given the lack of exposure effect on the myelination index, this finding might reflect a lower number of inter-hemispheric connections in female offspring of mothers who smoked during pregnancy.

The correlation of CTG repeat length with material and social deprivation in myotonic dystrophy

Socioeconomic deprivation has long been recognized as a prominent feature of myotonic dystrophy type 1 (DM1), but studies performed before the discovery of the mutation causing DM1 may have suffered an ascertainment bias towards the more severe forms of the disease. We have sought to clarify the relationship between CTG repeats, muscular impairment, and socioeconomic characteristics of 200 patients with DM1. Patients with DM1 reported lower educational attainment, lower employment rate, lower family income, and higher reliance on social assistance than the reference population. Logistic regression showed, on one hand, that CTG repeats and marital status were significant predictors of social assistance recipiency and, on the other hand, that CTG repeats and gender were significant predictors of low social support from family, after adjustment for age, gender, degree of muscular impairment, CTG repeats, educational level, and marital status. For example, each additional 100 CTG repeats was found to increase the odds of relying on social assistance by about 35% and having low social support by about 22%. The chances of experiencing socioeconomic deprivation are loaded heavily against patients with DM1. The relationship between increased CTG repeat length and higher risk of material and social deprivation must be acknowledged in the clinical management of DM1.

Hedgehog signaling in vertebrate eye development: a growing puzzle

The vertebrate retina has been widely used as a model to study the development of the central nervous system. Its accessibility and relatively simple organization allow analysis of basic mechanisms such as cell proliferation, differentiation and death. For this reason, it could represent an ideal place to solve the puzzle of Hh signaling during neural development. However, the extensive wealth of data, sometimes apparently discordant, has made the retina one of the most complicated models for studying the role of the Hh cascade. Given the complexity of the field, a deep analysis of the data arising from different animal models is essential. In this review, we will compare and discuss all reported roles of Hh signaling in eye development to shed light on its multiple functions.

Cross-species amplification of mitochondrial DNA sequence-tagged-site markers in conifers: the nature of polymorphism and variation within and among species in Picea

Primers previously developed to amplify specific non-coding regions of the mitochondrial genome in Angiosperms, and new primers for additional non-coding mtDNA regions, were tested for their ability to direct DNA amplification in 12 conifer taxa and to detect sequence-tagged-site (STS) polymorphisms within and among eight species in Picea. Out of 12 primer pairs, nine were successful at amplifying mtDNA in most of the taxa surveyed. In conifers, indels and substitutions were observed for several loci, allowing them to distinguish between families, genera and, in some cases, between species within genera. In Picea, interspecific polymorphism was detected for four loci, while intraspecific variation was observed for three of the mtDNA regions studied. One of these (SSU rRNA V1 region) exhibited indel polymorphisms, and the two others ( nad1 intron b/c and nad5 intron1) revealed restriction differences after digestion with Sau3AI (PCR-RFLP). A fourth locus, the nad4L- orf25 intergenic region, showed a multibanding pattern for most of the spruce species, suggesting a possible gene duplication. Maternal inheritance, expected for mtDNA in conifers, was observed for all polymorphic markers except the intergenic region nad4L- orf25. Pooling of the variation observed with the remaining three markers resulted in two to six different mtDNA haplotypes within the different species of Picea. Evidence for intra-genomic recombination was observed in at least two taxa. Thus, these mitotypes are likely to be more informative than single-locus haplotypes. They should be particularly useful for the study of biogeography and the dynamics of hybrid zones.

Sexual behaviour, condom use and HIV risk situations in the general population of Quebec

We conducted 3501 telephone interviews to determine the sexual and protective behaviours of the general population in Quebec. Among the 858 respondents who had had at least one occasional partner during the last 5 years, 25.4% had had at least one occasional partner who refused to use a condom. More women had had an occasional partner who had refused than men (29.8% vs 21.1%, P<0.001) and fewer women than men succeeded in negotiating condom use, but more of these women decided not to have sexual relations. The frequency of condom use during the last sexual relation changes if the partner is a regular cohabiting partner (12.5%), a regular non-co-habiting partner (42.2%) or an occasional partner (70.8%). Our study provides important information for the development of prevention programmes for the heterosexual population and demonstrates the importance of the type of relationship maintained by the partners on the sexual behaviours.

Evidence from sequence-tagged-site markers of a recent progenitor-derivative species pair in conifers

Black spruce (Picea mariana [B.S.P.] Mill.) and red spruce (Picea rubens Sarg.) are two conifer species known to hybridize naturally in northeastern North America. We hypothesized that there is a progenitor-derivative relationship between these two taxa and conducted a genetic investigation by using sequence-tagged-site markers of expressed genes. Based on the 26 sequence-tagged-site loci assayed in this study, the unbiased genetic identity between the two taxa was quite high with a value of 0.920. The mean number of polymorphic loci, the mean number of alleles per polymorphic locus, and the average observed heterozygosity were lower in red spruce (P = 35%, A(P) = 2.1, H(o) = 0.069) than in black spruce (P = 54%, A(P) = 2.9, H(o) = 0.103). No unique alleles were found in red spruce, and the observed patterns of allele distribution indicated that the genetic diversity of red spruce was essentially a subset of that found in black spruce. When considered in combination with ecological evidence and simulation results, these observations clearly support the existence of a progenitor-derivative relationship and suggest that the reduced level of genetic diversity in red spruce may result from allopatric speciation through glaciation-induced isolation of a preexisting black spruce population during the Pleistocene era. Our observations signal a need for a thorough reexamination of several conifer species complexes in which natural hybridization is known to occur.

Retinal stem cells in vertebrates

In fish and amphibia, retinal stem cells located in the periphery of the retina, the ciliary marginal zone (CMZ), produce new neurons in the retina throughout life. In these species, the retina grows to keep pace with the enlarging body. When birds or mammals reach adult proportions, however, their retinas stop growing so there appears to be no need for such a proliferative area with stem cells. It is a surprise, therefore, that recent data suggest that a region similar to the CMZ of fish and amphibia exists in the postnatal chick and the adult mouse.

Retinal stem cells in vertebrates

In fish and amphibia, retinal stem cells located in the periphery of the retina, the ciliary marginal zone (CMZ), produce new neurons in the retina throughout life. In these species, the retina grows to keep pace with the enlarging body. When birds or mammals reach adult proportions, however, their retinas stop growing so there appears to be no need for such a proliferative area with stem cells. It is a surprise, therefore, that recent data suggest that a region similar to the CMZ of fish and amphibia exists in the postnatal chick and the adult mouse.

Three-dimensional gait analysis in women with a total hip arthroplasty

OBJECTIVES

The purposes of this study were: (1) to identify the primary (hip) and secondary (neighboring joints) impairments during gait in subjects with a total hip arthroplasty total hip arthroplasty, (2) to determine which impairments persist when controlling for gait speed and (3) to study the relationships between primary and secondary impairments in order to describe the locomotor strategies used by these patients.DESIGN. This cross-sectional study compared the gait patterns of women with a total hip arthroplasty to those of healthy women.BACKGROUND. Several studies have reported residual hip impairments in the sagittal plane during gait after a total hip arthroplasty. There is, however, a substantial lack of knowledge in regard to the changes at the neighboring joints and in the other planes of movement.METHODS. Subjects have been examined during a gait laboratory testing session including the simultaneous recording of three-dimensional kinematics and ground reaction forces on one side, and bilateral activation of six lower limb muscles.RESULTS. A significant decrease of 20% in the hip extensor moment of force during the early stance phase was correlated (R(2)=43%) with a significant decrease of 14% in gait speed. Moreover, a significant decrease of 59% in the range of hip extension at the end of the stance phase was observed together with secondary impairments such as a significant increase in the anterior pelvic rotation, in knee flexion and in ankle dorsiflexion. Lastly, a significant increase in ipsilateral bending of the trunk during the single limb support on the operated limb was concomitant with a significant decrease in the hip abductor moment of force.CONCLUSIONS. The decrease in gait speed and the persistence of abnormal gait patterns one year after the total hip arthroplasty were associated respectively with a decrease in the hip extensor moment of force and with a decrease in the range of hip extension (sagittal plane) or in the hip abductor moment of force (frontal plane). RelevanceThe data provided in this paper may serve as guidelines to establish rehabilitation programs designed to restore optimal locomotor function.

Determination of vertebrate retinal progenitor cell fate by the Notch pathway and basic helix-loop-helix transcription factors

The retina is an excellent system in which to study neural cell fate decision mechanisms. It is an organized laminated structure with a limited array of cell types. During the last 5 years, experiments that perturb normal gene expression have highlighted some molecular mechanisms involved in cellular fate choice in the retina. By controlling when a retinoblast is allowed to differentiate, Delta-Notch signaling plays a critical role in the generation of neuronal diversity in the vertebrate retina. When cells are released from the inhibition mediated by the Delta-Notch pathway, basic helix-loop-helix (bHLH) transcription factors act as intrinsic factors that bias neuroblasts towards particular fates. In this review, we present an overview of the data leading to these conclusions on the role of the Delta-Notch pathway and the bHLH proteins on cell fate decisions during vertebrate retinogenesis.

X-ngnr-1 and Xath3 promote ectopic expression of sensory neuron markers in the neurula ectoderm and have distinct inducing properties in the retina

Xath3 encodes a Xenopus neuronal-specific basic helix-loop-helix transcription factor related to the Drosophila proneural factor atonal. We show here that Xath3 acts downstream of X-ngnr-1 during neuronal differentiation in the neural plate and retina and that its expression and activity are modulated by Notch signaling. X-ngnr-1 activates Xath3 and NeuroD by different mechanisms, and the latter two genes crossactivate each other. In the ectoderm, X-ngnr-1 and Xath3 have similar activities, inducing ectopic sensory neurons. Among the sensory-specific markers tested, only those that label cranial neurons were found to be ectopically activated. By contrast, in the retina, X-ngnr-1 and Xath3 overexpression promote the development of overlapping but distinct subtypes of retinal neurons. Together, these data suggest that X-ngnr-1 and Xath3 regulate successive stages of early neuronal differentiation and that, in addition to their general proneural properties, they may contribute, in a context-dependent manner, to some aspect of neuronal identity.

Giant eyes in Xenopus laevis by overexpression of XOptx2

Overexpression of XOptx2, a homeodomain-containing transcription factor expressed in the Xenopus embryonic eye field, results in a dramatic increase in eye size. An XOptx2-Engrailed repressor gives a similar phenotype, while an XOptx2-VP16 activator reduces eye size. XOptx2 stimulates bromodeoxyuridine incorporation, and XOptx2-induced eye enlargement is dependent on cellular proliferation. Moreover, retinoblasts transfected with XOptx2 produce clones of cells approximately twice as large as control clones. Pax6, which does not increase eye size alone, acts synergistically with XOptx2. Our results suggest that XOptx2, in combination with other genes expressed in the eye field, is crucially involved in the proliferative state of retinoblasts and thereby the size of the eye.

Misexpression of the RNA-binding protein ELRB in Xenopus presumptive neurectoderm induces proliferation arrest and programmed cell death

Proteins of the ELAV/Hu family share the presence of three RNA binding domains. In Xenopus, three nervous system-specific elav/Hu related genes, elrB, elrC and elrD, have been identified so far. The temporally regulated expression patterns of elrB, elrC and elrD suggest their involvement at different steps of neural differentiation. In the present study we misexpressed elrB by RNA injection in early Xenopus embryos and analyzed morphologically and molecularly its effects on neural development. We showed that heterochronous expression of elrB in presumptive neurectoderm down-regulates the expression of neural markers, such as N-tubulin, as well as that of other Xenopus elav-like genes, elrC and elrD, whereas ectopic expression of elrB in presumptive mesoderm has no effect on MyoD. Misexpression of elrB also induces severe defects in neural tube development, associated with massive cell loss resulting from early cell cycle arrest and programmed cell death. Our results are discussed in the context of early neural differentiation.

Xenopus elav-like genes are differentially expressed during neurogenesis

In Xenopus, three neural-specific elav-like genes (ELGs) have been identified, elrB/Xel-1, elrC and elrD. With the aim to highlight possible differences in the regulation of these genes, we compared their expression patterns during development. We had previously shown that elrB is expressed from the early tailbud stage onwards, in both the central and peripheral nervous system. Here we show that both elrC and elrD are expressed earlier than elrB in the developing neural tube and the cranial ganglia, with different temporal specificities. Double in situ hybridizations on brain cross-sections allowed us to define precisely the expression domains of elrB, elrC and elrD in the brain at the tailbud stage. What emerges from this study is a differential distribution of ELGs transcripts in the hindbrain. Also, double labeling with a motor neuron marker shows that in stage 41 tailbud embryos, elrD remains strongly expressed in motor neurons whereas elrC is mostly expressed in non-motor neuron cells.

The genetic sequence of retinal development in the ciliary margin of the Xenopus eye

The ciliary marginal zone is a perpetually self-renewing proliferative neuroepithelium at the perimeter of the retina in amphibians and fish. In the ciliary marginal zone (CMZ), cells are spatially ordered with respect to cellular development, deep stem cells being most peripheral and differentiating retinal progenitors being most central. This spatial gradient in the CMZ recapitulates embryonic retinogenesis and provides a powerful system to examine the relative order of gene expression during this process. A number of neurogenic and proneural genes have been described to have interacting roles in the development of the vertebrate nervous system, and so it is of major importance to put these genes in a hierarchical pathway. In no other system yet described are the developmental stages of neurogenesis arrayed so clearly in a spatial pattern as in the CMZ. We have therefore taken advantage of this system, using double in situ hybridizations on cross sections of the CMZ, to compare the spatial patterns of 15 proneural, neurogenic, and other genes involved in early and late phases of retinal development. In addition, we have positioned these expression patterns with respect to cell division. What emerges from this work is a spatial ordering of gene expression that predicts a genetic hierarchy governing vertebrate retinogenesis. By injecting messenger RNA for some of these genes into blastomeres of the Xenopus embryo and examining the effects on expression of the putative downstream genes, we have been able to corroborate some of the relationships between genes predicted to act sequentially.

Molecular recapitulation: the growth of the vertebrate retina

In postembryonic lower vertebrates, the ciliary marginal zone (CMZ) of the retina is a continuously growing zone in the central nervous system. By studying the cellular and molecular biology of the cells in this region, we have discovered that the CMZ can be divided into several zones, from peripheral to central, which reflect different stages of development of retinal stem cells. Based on the behavior of the cells and on the genes expressed in different regions, we propose here that cellular development in the CMZ recapitulates in space what happens in embryonic retinal development in time.

Xath5 participates in a network of bHLH genes in the developing Xenopus retina

We examined the function of basic-helix-loop-helix (bHLH) transcription factors during retinal neurogenesis. We identified Xath5, a Xenopus bHLH gene related to Drosophila atonal, which is expressed in the developing Xenopus retina. Targeted expression of Xath5 in retinal progenitor cells biased the differentiation of these cells toward a ganglion cell fate, suggesting that Xath5 can regulate the differentiation of retinal neurons. We examined the relationship between the three bHLH genes Xash3, NeuroD, and Xath5 during retinal neurogenesis and found that Xash3 is expressed in early retinoblasts, followed by coexpression of Xath5 and NeuroD in differentiating cells. We provide evidence that the expression of Xash3, NeuroD, and Xath5 is coupled and propose that these bHLH genes regulate successive stages of neuronal differentiation in the developing retina.

Subcellular distribution of Xenopus XEL-1 protein, a member of the neuron-specific ELAV/Hu family, revealed by epitope tagging

Drosophila and vertebrate elav/Hu genes are involved in the development and the maintenance of the nervous system. They all encode proteins that contain three RNA recognition motifs (RRM) and are thus expected to play a role in RNA metabolism. Drosophila ELAV and RBP9 proteins were reported to be exclusively distributed in nuclei of neurons, whereas known human Hu proteins display a bipartite nuclear and cytoplasmic distribution. We have previously isolated a member of this family in Xenopus, Xel-1, that is exclusively expressed in neural tissues from the early tailbud stage onward. In the present study, we report on the subcellular distribution of XEL-1 protein using myc epitope tagging, a strategy allowing the study of a single member of the ELAV/Hu family. We show that the subcellular distribution of exogenous XEL-1 protein in neural tissues depends on developmental stages. In the neural tube at the neurula stage, where endogenous Xel-1 is not expressed, exogenous tagged XEL-1 protein is localized in both the nucleus and the cytoplasm. At the tailbud stage, where endogenous Xel-1 is expressed, exogenous tagged XEL-1 protein is localized essentially in the cytoplasm of neural tube cells. In contrast, exogenous Drosophila ELAV protein localizes to the nucleus at all stages in Xenopus embryos. The variability in the subcellular localization of ELAV/Hu proteins in different species may have functional implications.

Acetic acid iontophoresis and ultrasound for the treatment of calcifying tendinitis of the shoulder: a randomized control trial

OBJECTIVE

To assess the effects of acetic acid iontophoresis (AAI) and ultrasound on calcifying tendinitis of the shoulder, and to determine the relation between changes in the radiological measures of calcium deposit (CD) and shoulder function.

DESIGN

Randomized control trial.

SETTING

General community, private practice.

PATIENTS

Twenty-two adults (7 men, 15 women) with a calcifying tendinitis of the shoulder, without associated conditions, stratified according to the type of lesions (X-ray: type I, fleecy appearance: type II, homogeneous), were randomly allocated to an experimental (EXP, n = 11) or to a control (CTL, n = 10) group.

INTERVENTIONS

CTL group, no treatment; EXP group, nine treatments including AAI (5% acetic acid solution via the negative electrode, 5mA galvanic current, 20 minutes) followed by continuous ultrasound (0.8w/cm2, 1MHz, 5 minutes).

MAIN OUTCOME MEASURES

Area and density of the CD, passive shoulder abduction (range of motion [ROM]), pain intensity.

RESULTS

Significant reduction in the area and density of CD (ANCOVA, p = .01 and .03) over time in the EXP and CTL groups, but no significant difference between groups for any of the variables measured. The decrease in the area of CD in type I lesions (n = 5) was larger (Mann-Whitney U test, p < .01) than in type II (n = 16) lesions. The relation was stronger (rs = .90) between changes in area and density of CD than between ROM and pain (rs = -.67). Correlations were weak (rs = .21 to .41) between radiological and functional changes.

CONCLUSION

The reduction in CD area and density likely results from a natural process rather than treatment (AAI and ultrasound); type I lesions (resorptive phase) are more likely to display resorption of the CD than type II lesions (formative phase). Reduction of the CD area does not necessary result in a functional improvement.

Species-specific RAPD fingerprints for the closely related Picea mariana and P. rubens

Species-specific molecular markers were designed to assist in the identification of closely related black spruce (Picea mariana [B.S.P.] Mill.) and red spruce (P. rubens Sarg.) in northeastern North America. Trees from six provenances of black spruce and three provenances of red spruce were sampled from outside the sympatric zone. They were first classified using a composite index of five qualitative morphological traits. The species-specific genetic markers were developed using random amplified polymorphic DNAs (RAPD) and a combination of bulk sample and individual tree analyses. Each species bulk sample was constructed from DNAs obtained from 12 trees that were from outside the sympatric zone and showed a morphological composite index specific of each species. A total of 161 primers were screened with the bulk samples. From these, 52 primers showing segregating fingerprints were further screened with the individual trees. Most of the markers observed were shared by the two species, and there was less diversity in P. rubens. A small number of markers were found to be monomorphic or nearly monomorphic and specific to either P. mariana or P. rubens. These markers remained species-specific when F1 progenies derived from independent intraspecific crosses were screened, and they were subsequently found to co-segregate in hybrids derived from independent interspecific crosses here used as controls.

Isolation and embryonic expression of Xel-1, a nervous system-specific Xenopus gene related to the elav gene family

We have identified a new member of the elav gene family in Xenopus laevis. This gene, Xel-1, like the other elav-related genes, encodes a putative RNA-binding protein that contains three RNA Recognition Motifs and is solely expressed in the nervous system. Xel-1 is most likely the Xenopus homologue of Hel-N1, one of the three known human genes related to elav. Xel-1 is not expressed in early neural precursors but rather in differentiating neurons of the central nervous system, as well as in the cranial and the spinal ganglion cells. Xel-1 thus appears to be an early differentiation marker for both the central and the peripheral nervous system of Xenopus laevis.

Synthesis of methotrexate prodrugs as an approach for drug targeting

Eleven methotrexale-alpha-peptides containing arginine (MTX-Arg), asparagine (MTX-Asn), cysteine (MTX-Cys), glutamine (MTX-Gln), histidine (MTX-His), lysine (MTX-Lys), methionine (MTX-Met), phenylalanine (MTX-Phe), proline (MTX-Pro), tryptophan (MTX-Trp) and tyrosine (MTX-Tyr) were produced by solid phase synthesis using the Fmoc method. Purity of the MTX derivatives was assessed by capillary zone electrophoresis (CZE). An enzymatic assay was then developed using CZE for monitoring the hydrolysis of the MTX-alpha-peptides by bovine pancreatic carboxypeptidase A (CP-A) leading to the release of free MTX. MTX-Phe appeared to be the most suitable substrate for CP-A out of the eleven tested with a hydrolysis rate comparable to that of hippuryl-L-phenylalanine, a natural substrate for CP-A. In vitro assays on a human ovarian teratocarcinoma cell line (CRL-1572), showed that MTX-Phe was non toxic, but when combined with 1 mU of CP-A, MTX-Phe cytotoxicity was enhanced considerably showing only two times less pharmacological activity than MTX. These results suggest that MTX-Phe is a potent prodrug and could be used in a drug targeting model combining monoclonal antibodies coupled with CP-A for a more specific approach in cancer therapy.