Actifit® polyurethane meniscal scaffold: MRI and functional outcomes after a minimum follow-up of 5 years.

BACKGROUND: Implantation of the Actifit® polyurethane meniscal scaffold in patients who have pain after partial meniscectomy provides short-term pain relief and better function. But there is a lack of information about medium-term outcomes. The objective of this longitudinal study was to evaluate the MRI and functional outcomes after a minimum follow-up of 5 years. It was hypothesized that the results are stable over time. MATERIAL AND METHODS: Fifteen consecutive patients (8 men, 7 women; mean age 30 years, range 19-47, mean BMI 25) were enrolled in the study between February 2008 and January 2011. Five patients also underwent ACL reconstruction and one underwent mosaicplasty. Nine lateral and six medial Actifit® implants were evaluated prospectively before the surgery and at a minimum of 12, 24 and 60 months' follow-up using a visual analogue scale (VAS) for pain, the objective and subjective IKDC scores, radiological and MRI analysis with measurement of the ICRS score, Genovese score and extrusion. RESULTS: The mean follow-up was 6 years (range 5-8.1). Two patients were lost to follow-up. Three patients were re-operated at 7, 19 and 30 months because they had not improved functionally and the implant appeared damaged on MRI. Partial removal of the implant did not improve the functional outcomes (mean subjective IKDC pre- and post-revision: 37.0 vs. 34.9). Two patients were lost to follow-up. In intention to treat (13 cases), the pain (VAS) and subjective IKDC score were improved between the preoperative period and the last follow-up (5.46 vs. 2.92, P=0.007 and 51.2 vs. 66.1, P=0.05). In per protocol (10 cases, failures excluded), the pain (VAS) and subjective IKDC score were improved (5.3 vs. 1.9, P=0.0009; 49.6 vs. 75.4, P=0.002) along with the pain, daily activities and quality of life components of the KOOS (60.6 vs. 86.0, P=0.0008; 70.3 vs. 90.2, P=0.001; 42.7 vs. 71.0, P=0.0058). The functional scores were stable between months 12, 24 and 60. ICRS cartilage score and mean meniscal extrusion were unchanged at the last follow-up (1.6 vs. 1.6 and 2.41 vs. 2.79). In all patients, the meniscal implant had an intermediate signal and reduced size on MRI. DISCUSSION: Despite an abnormal MRI appearance suggesting the meniscal scaffold is not fully mature after 5 years, the functional scores and cartilage status are stable at this time point. However, the failure rate is still high and removing the implant in patients with poor function does not improve the outcome. TYPE OF STUDY: Prospective cohort study Level IV.

Is coracoclavicular stabilisation alone sufficient for the endoscopic treatment of severe acromioclavicular joint dislocation (Rockwood types III, IV, and V)?

BACKGROUND: The primary objective was to evaluate correlations linking anatomical to functional outcomes after endoscopically assisted repair of acute acromioclavicular joint dislocation (ACJD). HYPOTHESIS: Combined acromioclavicular and coracoclavicular stabilisation improves radiological outcomes compared to coracoclavicular stabilisation alone. MATERIAL AND METHODS: A prospective multicentre study was performed. Clinical outcome measures were pain intensity on a visual analogue scale (VAS), subjective functional impairment (QuickDASH score), and Constant's score. Anatomical outcomes were assessed on standard radiographs (anteroposterior view of the acromioclavicular girdle and bilateral axillary views) obtained preoperatively and postoperatively and on postoperative dynamic radiographs taken as described by Tauber et al. RESULTS: Of 116 patients with acute ACJD included in the study, 48% had type III, 30% type IV, and 22% type V ACJD according to the Rockwood classification. Coracoclavicular stabilisation was achieved using a double endobutton in 93% of patients, and concomitant acromioclavicular stabilisation was performed in 50% of patients. The objective functional outcome was good, with an unweighted Constant's score ≥ 85/100 and a subjective QuickDASH functional disability score ≤ 10 in 75% of patients. The radiographic analysis showed significant improvements from the preoperative to the 1-year postoperative values in the vertical plane (decrease in the coracoclavicular ratio from 214 to 128%, p=10(-6)) and in the horizontal plane (decrease in posterior displacement from 4 to 0mm, p=5×10(-5)). The anatomical outcome correlated significantly with the functional outcome (absolute R value=0.19 and p=0.045). We found no statistically significant differences across the various types of constructs used. Intra-operative control of the acromioclavicular joint did not improve the result. Implantation of a biological graft significantly improved both the anatomical outcome in the vertical plane (p=0.04) and acromioclavicular stabilisation in the horizontal plane (p=0.02). The coracoclavicular ratio on the anteroposterior radiograph was adversely affected by a longer time from injury to surgery (p=0.02) and by a higher body mass index (BMI) (p=0.006). High BMI also had a negative effect on the difference in the distance separating the anterior edge of the acromion from the anterior edge of the clavicle between the injured and uninjured sides, as assessed on the axillary views (p=0.009). CONCLUSION: This study demonstrates that acute ACJD requires stabilisation in both planes, i.e., at the coracoclavicular junction and at the acromioclavicular joint. Coracoclavicular stabilisation alone is not sufficient, regardless of the type of implant used. Implantation of a biological graft should be considered when the time from injury to surgery is longer than 10days. The weight of the upper limb should be taken into account, with 6weeks of immobilisation to unload the construct in patients who have high BMI values. LEVEL OF EVIDENCE: II, prospective non-randomised comparative study.

Prognostic factors to succeed in surgical treatment of chronic acromioclavicular dislocations.

INTRODUCTION: Treatment of chronic acromioclavicular joint dislocation (ACJD) remains a poorly known and controversial subject. Given the many surgical options, it is not always easy to determine which steps are indispensable. METHODS: This article reports a multicenter prospective study. The clinical and radiological follow-up involved a comparative analysis of the preoperative and postoperative data at 1 year, including pain (visual analogue scale), subjective functional incapacity (QuickDASH), and the objective Constant score, as well as a comparative analysis of vertical and horizontal movements measured on simple x-rays. RESULTS: Based on a series of 140 operated ACJDs, we included 24 chronic ACJDs. The mean time to surgery was 46 weeks (range, 1 month to 4 years). The patients' mean age was 41 years, with a majority of males (75%), 72% of whom participated in recreational sports. Professionally, 40% of the subjects had jobs involving manual labor. We noted 40% grade III, 24% grade IV, and 36% grade V injury according to the Rockwood classification. In 92% of cases, coracoclavicular stabilization was provided by a double button implant, reinforced with a biological graft in 88% of the cases. In 29%, millimeters to centimeters of the distal clavicle were resected and acromioclavicular stabilization was associated in 54%. We observed complications in 33% of the cases. At 1 year postoperative, 21 patients underwent clinical and radiological follow-up (87.5%). Only 35% of the patients were satisfied or very satisfied, whereas 100% of them would recommend the operation. Full-time work was resumed in 91% of the cases and all sports could be resumed in 86%. The pre- and postoperative values at 1 year changed as follows: the mean Constant score improved from 61 to 87 (p=0.00002); the subjective QuickDASH score decreased from 41 to 9 (p=0.00002); and radiologically significant reduction of the initial displacement was observed in the vertical plane (p<10(-3)) and the horizontal plane (p=0.022). CONCLUSION: In this study, the favorable prognostic factors found were: time to surgery less than 3 months (p=0.02), associated acromioclavicular stabilization, and postoperative immobilization with a sling extended to 6 weeks. However, resection of the distal clavicle did not influence the final result. LEVEL OF PROOF: Level II prospective non-randomized comparative study.

Actifit® scaffold implantation: Influence of preoperative meniscal extrusion on morphological and clinical outcomes.

BACKGROUND: Meniscal substitutes have been suggested for the treatment of knee pain after partial meniscectomy. However, despite the partial nature of the initial meniscectomy, secondary extrusion of the substitute is common. The primary objective of this study was to evaluate morphological outcomes of meniscal substitute implantation and their potential associations with preoperative meniscal extrusion. HYPOTHESIS: Preoperative absolute meniscal extrusion in the coronal plane predicts poorer morphological and clinical outcomes. MATERIAL AND METHODS: Consecutive patients who received an Actifit(®) meniscal substitute between 2008 and 2011 were included prospectively. After 1 year and 2 years, the IKDC score and KOOS were determined and magnetic resonance imaging performed. The morphological evaluation consisted in measuring meniscal extrusion and cartilage coverage by the substitute in the coronal and sagittal planes. RESULTS: Twenty patients were included. Among them, 3 required subsequent removal of the substitute. The mean subjective IKDC score increased from 48.1 preoperatively to 56.4 after 2 years. Over the same period, the function/sports/recreational activities component of the KOOS improved significantly (42.9 vs. 55.0, P=0.04). Positive correlations between preoperative and 1-year values were demonstrated for both cartilage coverage in the coronal and the sagittal planes (P=0.03 and P=0.04, respectively) and coronal absolute meniscal extrusion (P=0.05). No significant differences were found between preoperative and 2-year values of cartilage coverage in the coronal and sagittal planes (P=0.38). There was a negative correlation linking preoperative meniscal extrusion in the coronal plane to 1-year cartilage coverage in the coronal and sagittal planes (P=0.01 and P=0.04, respectively). Preoperative absolute meniscal extrusion in the coronal plane correlated negatively with the subjective IKDC score after 1 year (P=0.02). DISCUSSION: Preoperative meniscal extrusion in the coronal plane strongly predicts clinical and morphological outcomes. Marked preoperative meniscal extrusion, even in a patient with symptoms after partial meniscectomy, should prompt an appraisal of whether allograft replacement may be more appropriate than a meniscal substitute. LEVEL OF EVIDENCE: IV, prospective study.

Morphology and genetics reveal an intriguing pattern of differentiation at a very small geographic scale in a bird species, the forest thrush Turdus lherminieri.

Mobile organisms are expected to show population differentiation only over fairly large geographical distances. However, there is growing evidence of discrepancy between dispersal potential and realized gene flow. Here we report an intriguing pattern of differentiation at a very small spatial scale in the forest thrush (Turdus lherminieri), a bird species endemic to the Lesser Antilles. Analysis of 331 individuals from 17 sampling sites distributed over three islands revealed a clear morphological and genetic differentiation between these islands isolated by 40-50 km. More surprisingly, we found that the phenotypic divergence between the two geographic zones of the island of Guadeloupe was associated with a very strong genetic differentiation (Fst from 0.073-0.153), making this pattern a remarkable case in birds given the very small spatial scale considered. Molecular data (mitochondrial control region sequences and microsatellite genotypes) suggest that this strong differentiation could have occurred in situ, although alternative hypotheses cannot be fully discarded. This study suggests that the ongoing habitat fragmentation, especially in tropical forests, may have a deeper impact than previously thought on avian populations.

Lateral meniscus allograft transplantation: clinical and anatomic outcomes after arthroscopic implantation with tibial tunnels versus open implantation without tunnels.

UNLABELLED: Meniscus allograft transplantation (MAT) is used to treat patients with knee pain after total or subtotal meniscectomy. The graft can be inserted during open or arthroscopic surgery. The objectives are anatomic horn positioning and strong fixation to the bone and capsule of an appropriately sized graft. HYPOTHESIS: Arthroscopic MAT with trans-tibial bone fixation ensures better mid-term functional outcomes and limits allograft extrusion. PATIENTS AND METHODS: We conducted a retrospective single-centre study of 23 consecutive patients who underwent MAT between 2001 and 2010. Among them, 11 had open surgery and anchoring of the horns without tunnels and 12 had arthroscopically-assisted surgery with bony fixation of the horns through trans-tibial tunnels. The two groups were comparable at baseline. Mean follow-up was 66.1 months. Post-operative outcomes were assessed using the IKDC score and KOOS, standard radiographs of both knees, and either magnetic resonance imaging or computed arthrotomography. We measured joint space narrowing, meniscal extrusion in the sagittal and coronal planes; and the degree of cartilage coverage by the graft using an index developed for this study. RESULTS: The overall failure rate was 17.4% (4/23, two cases each of complete and partial graft removal). Joint space narrowing increased by 28% versus the pre-operative value (P=0.009). IKDC and KOOS values were not significantly different between the two groups. Absolute meniscus extrusion was greater in the arthroscopy group (4mm vs. 3mm, P=0.03). DISCUSSION: Osteoarthritis of the transplanted compartment is unavoidable. Open surgery is associated with less meniscal extrusion. The clinical outcomes are independent from the technique used. Other factors require investigation, including graft rehabilitation, quality peripheral suturing, and intermeniscal ligament reconstruction. LEVEL OF EVIDENCE: IV, retrospective study.

Protease-modulating polyacrylate-based hydrogel stimulates wound bed preparation in venous leg ulcers--a randomized controlled trial.

BACKGROUND: Stringent control of proteolytic activity represents a major therapeutic approach for wound-bed preparation. OBJECTIVES: We tested whether a protease-modulating polyacrylate- (PA-) containing hydrogel resulted in a more efficient wound-bed preparation of venous leg ulcers when compared to an amorphous hydrogel without known protease-modulating properties. METHODS: Patients were randomized to the polyacrylate-based hydrogel (n = 34) or to an amorphous hydrogel (n = 41). Wound beds were evaluated by three blinded experts using photographs taken on days 0, 7 and 14. RESULTS: After 14 days of treatment there was an absolute decrease in fibrin and necrotic tissue of 37.6 ± 29.9 percentage points in the PA-based hydrogel group and by 16.8 ± 23.0 percentage points in the amorphous hydrogel group. The absolute increase in the proportion of ulcer area covered by granulation tissue was 36.0 ± 27.4 percentage points in the PA-based hydrogel group and 14.5 ± 22.0 percentage points in the control group. The differences between the groups were significant (decrease in fibrin and necrotic tissue P = 0.004 and increase in granulation tissue P = 0.0005, respectively). CONCLUSION: In particular, long-standing wounds profited from the treatment with the PA-based hydrogel. These data suggest that PA-based hydrogel dressings can stimulate normalization of the wound environment, particularly in hard-to-heal ulcers.

Development of an in vitro fibrin clot model to evaluate fibrinolytic agents for wound care application.

OBJECTIVE: To describe an in vitro fibrin clot model that could reliably assess the fibrinolytic activity of enzymatic debriding agents for wound care application. METHOD: A model of a fibrin clot was reconstructed in vitro by mixture of human fibrinogen and (alpha)-thrombin supplemented with factor XIII. These clots were then treated with enzymatic ointments. Fibrinolytic activity was investigated by measuring D-dimer levels, using an automated immunoturbidimetric Liatest D-dimer assay. RESULTS: Collagenase and papain-urea ointments demonstrated fibrinolytic activity which was macroscopically visible. Their effect was identical on the in vitro reconstructed fibrin clot and ex vivo collected wound fibrin clot; collagenase and papain-urea both induced a complete degradation and dissolution of both fibrin clots after 24 hours of treatment. This was associated with an increase in D-dimer concentration. CONCLUSION: This reconstructed fibrin clot in vitro model has the potential to predict the efficacy of fibrinolytic agents and therefore appears to be a suitable model for in vitro assays. DECLARATION OF INTEREST: This study was supported by a grant from URGO Laboratory.

[Chronic wound care leads to the bacterial contamination of the environment]. / Les soins des plaies chroniques entraînent une contamination bactérienne de l'environnement.

AIM: The aim of this study was to determine levels of bacterial contamination of the environment during chronic wound dressing changes. METHODS: Sampling of chronic wounds and of the environment (air and surfaces) was performed during changing of chronic wound dressing. A series of samples was defined as the entire sample for a given day for a given patient. Five sequential samples of air and six samples of surfaces were taken for each series. Staphylococcus aureus, Pseudomonas aeruginosa and enterobacteria were specifically cultured. RESULTS: Thirty series of samples were taken for 26 different patients. Twenty-seven out of these 30 series were colonized with one or two of the target species. For 13 series of the latter samples (13/27, 48.1%), bacteria isolated from the wound were recovered in the environment, namely S. aureus and P. aeruginosa. The six enterobacteria isolated from wounds were not retrieved in the environment. Air samples were more often positive than surfaces samples. CONCLUSION: We demonstrated frequent contamination of the hospital environment with bacteria colonizing wounds during dressing changes. This indicates that wearing of masks and hand disinfection after contact with the environment constitute key measures in the control of bacterial cross-transmission.

Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2011-31 January 2012.

This article documents the addition of 473 microsatellite marker loci and 71 pairs of single-nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Barteria fistulosa, Bombus morio, Galaxias platei, Hematodinium perezi, Macrocentrus cingulum Brischke (a.k.a. M. abdominalis Fab., M. grandii Goidanich or M. gifuensis Ashmead), Micropogonias furnieri, Nerita melanotragus, Nilaparvata lugens Stål, Sciaenops ocellatus, Scomber scombrus, Spodoptera frugiperda and Turdus lherminieri. These loci were cross-tested on the following species: Barteria dewevrei, Barteria nigritana, Barteria solida, Cynoscion acoupa, Cynoscion jamaicensis, Cynoscion leiarchus, Cynoscion nebulosus, Cynoscion striatus, Cynoscion virescens, Macrodon ancylodon, Menticirrhus americanus, Nilaparvata muiri and Umbrina canosai. This article also documents the addition of 116 sequencing primer pairs for Dicentrarchus labrax.

Age-dependent allocation of carotenoids to coloration versus antioxidant defences.

Aging is commonly attributed to age-related changes in oxidative damage due to an increased production of reactive oxygen species (ROS) and a weakened efficacy of enzymatic antioxidants. These age-related changes might therefore modify the use of dietary antioxidants, including carotenoids. As carotenoids are closely associated with the expression of secondary sexual signals, the allocation of carotenoids to sexual signal versus antioxidant defences may vary with age. In this study, we explored how carotenoid-based ornament and antioxidant activity varied with age and how an inflammatory-induced oxidative burst affected ornament and antioxidant activity across a range of ages. Using zebra finches (Taeniopygia guttata) as a model species, we assessed circulating carotenoids, beak coloration and the plasma antioxidant status of birds of different ages before and after an inflammatory challenge. Our results show that old individuals display similar carotenoid-based sexual signals regardless of the availability of circulating carotenoids, suggesting a terminal investment of old individuals in their last reproductive event. Additionally, we found that an inflammatory insult induced a decrease in the total antioxidant activity and in the expression of a carotenoid-based sexual signal in the oldest individuals. These results suggest that old individuals pay an extra cost of immune activation possibly because the efficiency of antioxidant machinery varies with age.

[Familial infantile myofibromatosis]. / Myofibromatose infantile familiale.

BACKGROUND: Infantile myofibromatosis (IM) is the most common fibrous disorder of infancy and childhood. It is characterized by congenital tumours of the skin, striated muscle, bones and viscera. Most cases are sporadic and few familial cases have been reported. PATIENTS AND METHODS: We describe a 5-month-old girl presenting with two congenital nodules. The diagnosis of infantile myofibromatosis was based on clinical and histopathological examination. Surgical excision was performed and there was no relapse at six years. The patient's brother presented multiple nodules and toe necrosis at birth due to infantile myofibromatosis. Two months later, the congenital nodules increased in size and new nodules developed. Surgical excision was performed. At 11 months of age, the boy presented with cranial relapse and bone resorption at P3 of the third right toe. The clinical and radiological investigations were normal. DISCUSSION: Three clinical forms of IM have been described: solitary cutaneous nodules, multiple cutaneous nodules and generalized MI with visceral involvement. The prognosis is good except in generalized MI. All familial cases of MI may be interpreted as autosomal dominant or alternatively there may be genetic heterogeneity. Strict follow-up is recommended to identify potentially life-threatening complications. Spontaneous regression usually occurs but in some cases the treatment of choice is surgical removal.

[Difficulties of interpretation in toxoplasma serology in a pregnant woman in the context of a maternofetal alloimmunization against HPA-1a platelet antigen]. / A propos d'un cas de sérologie toxoplasmique chez une patiente enceinte dans un contexte d'allo-immunisation foetomaternelle anti-HPA-1a.

Serological status in case of Toxoplasma gondii infection needs to be established either before or at the beginning of a pregnancy. However, clinical biologists are often facing conflicting serological results that are difficult to interpret: we report here the case of a woman in her 30th week of pregnancy. Both her IgM and IgG were negative at the 14th week of pregnancy; but suddenly, starting from the 20th week, her IgG became positive while her IgM remained negative. We remind here of the most frequent hypothesis that can explain a sudden and isolated increase of anti-T. gondii IgG: Is it a technical problem (specificity)? Is it a drug interference? Eventually, we found that the patient was receiving, since the 16th week of pregnancy, every week an intravenous perfusion of polyvalent immunoglobulins. Since we didn't know if the IgG present in this perfusion can protect the patient against toxoplasmosis, we decided to consider this women as non immune.

[Melanoma in invisible naevus spilus]. / Mélanome développé sur naevus spilus inapparent.

BACKGROUND: Diagnosis of naevus lesions may be complex where they contain little or no pigmentation. Naevus spilus (or naevus on naevus) is, generally, readily identified by the difference in pigmentation between overlying and underlying naevi and healthy skin. Malignant transformation of naevus spilus is rare. We report two cases of melanoma in which surgical procedures revealed underlying melanocyte lesions, diagnosed at histology but undetectable on clinical examination. PATIENTS AND METHODS: Two patients were operated for melanoma in which surgery, at a site remote from the melanoma, suggested incomplete relapse despite the fact that previous clinical examination had indicated healthy skin. A diagnosis was made of melanoma in invisible naevus spilus. DISCUSSION: Diagnosis of melanoma in invisible naevus spilus may be suspected where several naevi are found together in a specific area. The main problem is the therapeutic stance to be adopted since complete excision of the underlying naevi is difficult in practice. Wood's light examination may be helpful.

Carotenoid trade-off between parasitic resistance and sexual display: an experimental study in the blackbird (Turdus merula).

Many parasites depress the expression of the carotenoid-based colour displays of their hosts, and it has been hypothesized that animals face a trade-off in carotenoid allocation between immune functions and 'degree of ornamentation'. While numerous correlative studies suggest that parasite infection decreases the intensity of carotenoid-based colour displays, the existence of this trade-off has never been demonstrated experimentally in a host-parasite model. In this study, we used the blackbird (Turdus merula) and Isospora (an intestinal parasite) to assess whether this trade-off does indeed exist. Blackbirds were supplemented with carotenoids while simultaneously being exposed to parasites. Supplemented males circulated more carotenoids in the blood and developed more brightly coloured bills than unsupplemented males. In addition, supplementation slowed down the replication rate of parasites. Supplementation with carotenoids enabled infected birds to maintain their bill coloration, whereas birds that were infected but not supplemented showed reduced bill coloration. At the same time, infection slowed carotenoid assimilation in the blood. Overall, we demonstrated that bill colour reflects a bird's health, and that only males with a carotenoid-rich diet are capable of coping with costs associated with parasitic infection. Carotenoids are thus traded off between host physiological response to parasites and secondary sexual traits. Further investigations are required to determine the physiological mechanisms that govern this trade-off.

[Hemoglobin-based oxygen carriers and trials to substitute red blood cells]. / Les transporteurs d'oxygène à base d'hémoglobine et les tentatives de substituer les globules rouges.

The idea to develop a blood substitute was stimulated by the need of military in the last two world wars and by transmission of pathogenic germs (Hepatitis B in 1960, HIV in 1980 and Hepatitis C in 1990) during blood transfusion that limited the donor blood transfusion. There are two main groups of blood substitutes: perfluorocarbon emulsions and hemoglobin-based oxygen carriers (HBOC). These latter are of natural origin: human, bovine or recombinant and undergo three modifications types: chemicals (intramolecular cross-linking, polymerisation, conjugation to macromolecules and combination of several chemical modifications), genetics or technological by microencapsulation. HBOCs are in different phases of clinical trials and some of them present side effects (hemodynamic and oxidative). The understanding of these effects and the possibility of correcting them, condition their use on a large scale and the economic consequences, which they can generate.

[Potential mechanism of dextran-conjugated hemoglobin penetration inside arterial wall]. / Mécanisme potentiel de la pénétration de l'hémoglobine conjuguée au dextrane dans la paroi artérielle.

Several reports indicated that cell-free hemoglobin induced vasoconstriction. This phenomenon was due to different pharmacological (NO trapping, vasoactive agents release and endothelial uptake...) and physical (viscosity and oxidative process of cell-free hemoglobin...) factors. We have previously showed that the blood pressure increase would be due to the presence of Dex-BTC-Hb inside arterial wall. However, we do not know how hemoglobin penetrate inside arterial wall. The objective of this study was to examine the new hypothesis of hemoglobin penetration inside arterial wall dependent of endocytosis. For this reason, an endocytosis inhibitor, cytochalasin D, was tested. We measured in anesthetized guinea pigs, the evolution of mean arterial pressure (MAP) and plasma hemoglobin concentration in presence or absence of cytochalasin D (1.6 x 10(-4) M). These measurements were carried out before and after 50% isovolemic exchange transfusion (IET) with two cell-free hemoglobins: Dex-BTC-Hb (300 kDa) and stroma-free hemoglobin (64.5 kDa). The administration of Dex-BTC-Hb or stroma-free hemoglobin induced an immediate increase in MAP that peaked within 17 min after IET and returned to baseline after 120 min. cytochalasin D attenuated the elevation of MAP when administrated before Dex-BTC-Hb but not when administrated before stroma-free hemoglobin. Furthermore, without cytochalasin D, plasma hemoglobin concentration after Dex-BTC-Hb or stroma-free hemoglobin administration decreased significantly 120 min after IET. In presence of cytochalasin D, plasma hemoglobin concentration stayed constant in Dex-BTC-Hb-treated animals but not in stroma-free hemoglobin-treated animals. cytochalasin D inhibits the endocytosis in case of Dex-BTC-Hb but not in case of stroma-free hemoglobin. This would be due to the molecular weight of cell-free hemoglobin. Based on these data, we suggest that endocytosis is one of the mechanisms by which cell-free hemoglobin with high molecular weight penetrated inside vascular endothelial cells. This endocytosis would have an impact on induced hypertension.

Lead concentrations in feathers and blood of common blackbirds (Turdus merula) and in earthworms inhabiting unpolluted and moderately polluted urban areas.

Despite the dramatic decrease of atmospheric lead (Pb) concentrations in urban areas of most industrialised countries, we hypothesised that urban common blackbirds (Turdus merula) may still be contaminated by Pb concentrations of toxicological concern due to transfer from soil through the food chain. We sampled blackbirds and earthworms, one of their main preys, in Besançon, a middle-size city of Eastern France (where atmospheric Pb concentrations decreased from 0.5 microg/m(3) in 1987 to nearly 0 in 2002) and in a rural reference site. Lead concentrations were determined in the tissues of the different functional groups of earthworms (anecic, epigeous and endogeous) and in blood, washed and unwashed outermost tail feathers and breast feathers of blackbirds. Fresh masses and an index of individual body condition were measured in the two blackbird populations as biomarkers of possible toxic effects. Lead concentrations in earthworms did not differ among functional groups but were significantly higher in urban individuals than in rural ones. Concentrations in outermost tail feathers, breast feathers and blood were significantly higher in urban blackbirds (7.75+/-4.50, 3.15+/-1.77 and 0.15+/-0.09 microg/g, respectively) than in rural individuals. In urban blackbirds, concentrations in washed and unwashed outermost tail feathers allowed estimating the external contamination (probably due to deposition of dusts and/or to excretion of the uropygial gland) at 37% of the total Pb concentration of the unwashed feathers. Remaining 63% should be linked to food chain transfer of persistent Pb from urban soils. Among the 23 sampled blackbirds, 4 of them (3 in the urban site and 1 in the rural site) exhibited blood Pb concentrations higher than the benchmark value (0.20 microg/g) related to subclinical and physiological effects in birds. Variations in body condition index were not correlated to Pb concentrations in blackbird tissues. Present results suggest that Pb may still be of environmental concern for blackbirds in urban areas because of the persistence of Pb in soils and its transfer through the food chain.

Sensitive measure of prevalence and parasitaemia of haemosporidia from European blackbird (Turdus merula) populations: value of PCR-RFLP and quantitative PCR.

Haemosporidian parasites are common in birds in which they act as an important selective pressure. While most studies so far have focused on the effect of their prevalence on host life-history traits, no study has measured the effect of parasitaemia. We developed molecular methods to detect, identify and quantify haemosporidia in 2 natural populations of the Blackbird Turdus merula. Three different parasite genotypes were found - 1 Haemoproteus and 2 Plasmodium. A PCR-RFLP screening revealed that only approximately 3% of blackbirds were free of parasites, compared to the 34% of uninfected birds estimated by blood smear screening. A quantitative PCR (q-PCR) assay revealed a weaker parasitaemia in microscopically undetected parasites compared to microscopically detected ones. Large parasitaemia differences were found between parasite species, suggesting either differing parasite life-histories or host resistance. Parasitaemias were also weaker in male hosts, and in urban habitats, suggesting that both host factors (e.g. immunity) and habitat characteristics (e.g. vector availability) may modulate parasite density. Interestingly, these differences in parasitaemia were comparable to differences in parasite prevalence estimated by smear screening. This suggests that previous results obtained by smear screening should be reinterpreted in terms of parasitaemia instead of parasite prevalence.

[Relationship between arterial pressure evolution and free hemoglobin distribution into vascular wall in guinea pigs]. / Relation entre l'évolution de la pression artérielle et la distribution de l'hémoglobine libre dans la paroi vasculaire chez le cobaye.

Free hemoglobin (Hb) present at high concentration in plasma--in case of hemolysis, hemoglobin based oxygen carrier (HBOC) administration or in case of subarachnoid hemorrhage--induce hypertension as result of vasoconstriction. In this context, we studied on an exchange transfusion (ET) model at 50% of hematocrit with a HBOC, the distribution of this Hb inside abdominal aortic wall in guinea pigs in relation with mean arterial pressure (MAP) evolution. MAP was monitored during 180 min after ET and rings of abdominal aorta were taken at different times, when modifications of MAP were important, and analyzed by immunohistochemistry and confocal microscopy. Gelofusine 4%, used as control, did not modify MAP while free Hb increased MAP that reached its maximum (53% of hypertension) at t=17 min after the end of ET. MAP started to decrease (45% of hypertension) at t =60 min after ET, and recovered its baseline value at t=180 min. Confocal analysis of the vessel showed that: at 17 min (when hypertension was maximal), free Hb was present in endothelial cells (EC) and in vasa vasorum; at t=60 min (when hypertension decreased) and at t =10 min (when hypertension disappeared), free Hb was detected still in EC, but inside all abdominal aorta wall too. These results suggest in the first time that free Hb could induce a hypertension by direct interaction with EC but would also be unable to maintain this hypertension in spite of its massive tissue distribution.