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Biomedical subjects

N Duval

Publications and source records attributed to N Duval.

At least 19 recordsLinked to original sources
PubMed2002

Computer-based method for the 3-D kinematic analysis of posterior cruciate ligament and postero-lateral corner lesions.

Posterior cruciate ligament (PCL) rupture, whether or not combined with postero-lateral corner (PLC) tears, are more often diagnosed today thanks to improved imaging techniques. However, due to the lack of reliable instrumentation to quantitatively evaluate the knee, much is still unknown about the function of these ligamentous structures. The aim of this paper is to present results on the effect of progressive resection of the PCL and PLC on knee laxity and 3-D knee kinematics. The results show that 3-D movement analysis is important and complements laxity measurements by helping to interpret the complex alteration of knee function.

Aged↗
PubMed2002

Comparison of two methods for reconstruction of the posterior cruciate ligament using a computer based method: quantitative evaluation of laxity, three-dimensional kinematics and ligament deformation measurement in cadaver knees.

The aim of this paper is to present a biomechanical comparison of two different methods for reconstruction of the posterior cruciate ligament in cadaver knees. We used an original computer-based method allowing precise calculation of three-dimensional (3D) knee kinematic parameters as well as the estimation of combined graft deformation (elongation-flexion-torsion). After isolated posterior cruciate ligament (PCL) dissection, double bundle and 'over-the-bottom' methods were performed successively on each knee using synthetic polyester ligaments. The effect of pre-tensioning was tested with the 'over-the-bottom' method. antero-posterior (A-P) and rotational laxity as well as 3D kinematics were recorded and analysed. Our computer based method allowed us to show that both reconstruction methods were equivalent in restoring A-P and rotational laxity as well as kinematic curves. Combined deformation of the prostheses was equivalent for both ligaments.

Aged↗
PubMed2002

Can altered production of interleukin-1beta, interleukin-6, transforming growth factor-beta and prostaglandin E(2) by isolated human subchondral osteoblasts identify two subgroups of osteoarthritic patients.

OBJECTIVE: To determine the capacity of human subchondral osteoarthritic osteoblasts (Ob) to produce interleukin (IL)-1beta, IL-6, transforming growth factor-beta (TGF-beta) and prostaglandin E(2) (PGE(2)), and determine if a relationship exists between IL-1beta, TGF-beta, PGE(2) and IL-6 production. METHODS: We measured the abundance of IL-1beta, IL-6, TGF-beta and PGE(2) using very sensitive ELISA in conditioned-media of human primary subchondral Ob from normal individuals and osteoarthritic patients. Selective inhibition of IL-6 or IL-6 receptor signaling was performed to determine its effect on PGE(2) production whereas the inhibiton of PGE(2) production was performed to determine its effect on IL-6 production. The expression of bone cell markers and urokinase plasminogen activator (uPA) activity was also determined. RESULTS: Osteoarthritic Ob produced all these factors with greater variability than normal cells. Interestingly, the production of IL-6 and PGE(2) by osteoarthritic Ob separated patients into two subgroups, those whose Ob produced levels comparable to normal (low producers) and those whose Ob produced higher levels (high producers). In those cells classified as high osteoarthritic Ob, PGE(2) and IL-6 levels were increased two- to three-fold and five- to six-fold, respectively, compared with normal. In contrast, while using their IL-6 and PGE(2) production to separate osteoarthritic Ob into low and high producers, we found that IL-1beta levels were similar in normal and all osteoarthritic Ob. Using the same criteria, TGF-beta levels were increased in all osteoarthritic Ob compared with normal. Reducing PGE(2) synthesis by Indomethacin [a cyclo-oxygenase (COX) -1 and -2 inhibitor] reduced IL-6 levels in all osteoarthritic Ob, whereas Naproxen (a more selective COX-2 inhbitor) reduced PGE(2) and IL-6 levels only in the high osteoarthritic group. Conversely, PGE(2) addition to osteoarthritic Ob enhanced IL-6 production in both groups. Moreover, the addition of parathyroid hormone also stimulated IL-6 production to similar normal levels in both osteoarthritic groups. In contrast, using an antibody against IL-6 or IL-6 receptors did not reduce PGE(2) levels in either group. The evaluation of alkaline phosphatase activity, osteocalcin release, collagen type I and uPA activity in osteoarthritic Ob failed to show any differences between these cells regardless to which subgroup they were assigned. CONCLUSIONS: These results indicate that IL-6 and PGE(2) production by subchondral Ob can discriminate two subgroups of osteoarthritic patients that cannot otherwise be separated by their expression of cell markers, and that endogenous PGE(2) levels influence IL-6 synthesis in osteoarthritic Ob.

Aged↗
PubMed2002

A new generation of artificial ligaments in reconstruction of the anterior cruciate ligament. Two-year follow-up of a randomised trial.

We have undertaken a randomised clinical trial comparing two methods of reconstruction of the anterior cruciate ligament in patients with chronic instability. We used an ipsilateral bone-patellar-tendon-bone autograft in 27 patients and the Ligament Advancement Reinforcement System (LARS) artificial ligament in 26. Assessment before and at two, six, 12 and 24 months after surgery, included the history, physical examination, a modified International Knee Documentation Committee (IKDC) score, the Tegner score, the Knee Injury and Osteoarthritis Outcome Score (KOOS) and instrumented laxity testing. There were no cases of reactive synovitis or of infection of the knee, and there was no difference regarding the failure rate between the two groups. The IKDC showed no significant differences between the two groups at any stage of the follow-up. The KOOS evaluation showed consistently better results in all subscales for the LARS group during the first year of follow-up. After 24 months these differences were no longer evident. Instrument-tested laxity was greater in the LARS group at all stages of follow-up, but the differences were not significant at 24 months. Our findings suggest that at follow-up at 24 months the LARS ligament seems to be a satisfactory treatment option, especially when an early return to high levels of activity is demanded.

Activities of Daily Living↗
PubMed2001

Correlation between patients' satisfaction and objective measurement of knee stability after ACL reconstruction using a patellar tendon autograft.

We evaluated the relationship between patients' satisfaction and objective measurements of knee stability after reconstruction of the ACL using a patellar tendon autograft. An examination of 59 patients 2-7 years after surgery was carried out. Assessment was made by the Knee and Osteoarthritis Outcome Score for patient satisfaction, a modified International Knee Documentation Committee form for clinical knee stability and a Telos stress radiography for PA stability. The results show that patients' satisfaction was much greater than the objective evaluation would suggest. We conclude that documenting mechanical knee stability alone is inadequate for follow-up studies and a questionnaire assessing patient satisfaction should be added.

Anterior Cruciate Ligament↗
PubMed2001

Functional analysis of a dominant mutation of human connexin26 associated with nonsyndromic deafness.

Cx26 has been implicated in dominant (DFNA3) and recessive (DFNB1) forms of nonsyndromic sensorineural deafness. While most homozygous DFNB1 Cx26 mutations result in a simple loss of channel activity, it is less clear how heterozygous mutations in Cx26 linked to DFNA3 cause hearing loss. We have tested the ability of one dominant mutation (W44C) to interfere with wild-type human Cx26 (HCx26wt). HCx26wt induced robust electrical conductance between paired oocytes, and facilitated dye transfer between transfected HeLa cells. In contrast, oocyte pairs injected with only W44C were not electrically coupled above background levels, and W44C failed to dye couple transfected HeLa cells. Moreover, W44C dramatically inhibited intercellular conductance of HCx26wt when co-expressed in an equal ratio, and the low levels of residual conductance displayed altered gating properties. A nonfunctional recessive mutation (W77R) did not inhibit the ability of HCx26wt to form functional channels when co-injected in the same oocyte pairs, nor did it alter HCx26wt gating. These results provide evidence for a functional dominant negative effect of the W44C mutant on HCx26wt and explain how heterozygous Cx26 mutations could contribute to autosomal dominant deafness, by resulting in a net loss, and/or alteration, of Cx26 function.

Animals↗
PubMed2001

Antiplatelet and antithrombotic activity of SL65.0472, a mixed 5-HT1B/5-HT2A receptor antagonist.

The antiplatelet and antithrombotic activity of SL65.0472 (7-fluoro-2-oxo-4-[2-[4-(thieno [3,2-c]pyrin-4-yl) piperazin-1-yl]ethyl]-1,2-di-hydroquinoline-acetamide), a mixed 5-HT1B/5-HT2A receptor antagonist was investigated on 5HT-induced human platelet activation in vitro, and in rat, rabbit and canine platelet dependent thrombosis models. SL65.0472 inhibited 5-HT-induced platelet shape change in the presence of EDTA (IC50 values = 35, 69 and 225 nM in rabbit, rat and human platelet rich plasma (PRP)), and also inhibited aggregation induced in human PRP by 3-5 microM 5-HT + threshold concentrations of ADP (0.5-1 microM) or collagen (0.3 microg/ml) with mean IC50 values of 49 +/- 13 and 48 +/- 6 nM respectively. SL65.0472 inhibited thrombus formation when given both intravenously 5 min and orally 2 h prior to assembly of an arterio-venous (A-V) shunt in rats as from 0.1 and 0.3 mg/kg respectively. It was active in a rabbit A-V shunt model with significant decreases in thrombus weight as from 0.1 mg/kg i. v. and at 10 mg/kg p.o. The delay to occlusion in an electric current-induced rabbit femoral artery thrombosis model was increased by 251% (p <0.05) after 20 mg/kg p.o. SL65.0472 (30 microg/kg i.v.) virtually abolished coronary cyclic flow variations (7.2 +/- 1.0/h to 0.6 +/- 0.6/h, p <0.05) and increased minimum coronary blood flow (1.2 +/- 0.8 ml/min to 31.8 +/- 8.4 ml/min, p <0.05) in a coronary artery thrombosis model in the anaesthetised dog. Finally, SL65.0472 significantly increased the amount of blood lost after rat tail transection at 3 mg/kg p.o. Thus the anti-5-HT2A component of SL65.0472 is reflected by its ability to inhibit 5-HT-induced platelet activation, and platelet-rich thrombus formation.

Animals↗
PubMed2001

Transforming growth factor-beta induced collagenase-3 production in human osteoarthritic chondrocytes is triggered by Smad proteins: cooperation between activator protein-1 and PEA-3 binding sites.

OBJECTIVE: To examine the signaling pathways leading to transforming growth factor-beta (TGF-beta) induced collagenase-3 production in human osteoarthritic (OA) chondrocytes, as well as the transcription factors and their binding sites involved in the transcriptional control of collagenase-3 gene. METHODS: Identification of the TGF-beta signaling pathway was by Western immunoblotting using specific antibodies for the phosphorylated forms of p44/42 and p38 MAPK, SAPK/JNK, and the Smad2 protein. Electromobility shift assays (EMSA) were carried out for activator protein- (AP-1), polyomavirus enhancer A (PEA-3), activin-response-element-like, Smad-binding-element-like, and TGF-beta inhibitory element oligonucleotides. Supershift assays using antibodies to the Jun, Fos, and Smad families of proteins were used for identification of transcription factors. Chondrocyte transfections were also performed using the -133CAT collagenase-3 promoter plasmid (containing PEA-3, AP-1, and TATA sites) and mutated AP-1 and PEA-3 sites. RESULTS: The primary target of TGF-beta induced collagenase-3 in OA chondrocytes was the Smad2 protein, with significant phosphorylation within 5 min. Contrasting with the Smad2, the untreated OA chondrocytes already had detectable levels of the phosphorylated forms of p38 and p44/42 MAPK. Of the oligonucleotides tested, EMSA revealed that TGF-beta treated OA chondrocyte proteins bound only to the AP-1 and PEA-3. Supershifts with the AP-1 oligonucleotide showed the presence of the Jun (c-Jun, JunB, JunD) and Fos (c-Fos, FosB, Fra-1, Fra-2) proteins in the untreated and TGF-beta treated OA chondrocytes, whereas only Smad proteins (Smad2, 3, 4) were present in the AP-1 binding proteins from the TGF-beta treated chondrocytes. The AP-1 mutation decreased both basal (95%) and TGF-beta induced (99%) collagenase-3 production, whereas the PEA-3 mutation decreased the basal (15%) but more significantly (50%) the TGF-beta induced transcription. CONCLUSION: Smad proteins are the main cytoplasmic signaling pathways in TGF-beta stimulated collagenase-3 in OA chondrocytes. The AP-1 site appears critical for upregulation of collagenase-3 production, but TGF-beta stimulation requires both AP-1 and PEA-3 sites for optimal response.

Aged↗
PubMed2001

[Standards, options and recommendations: Good clinical practice in the dietetic management of cancer patients: hospital catering].

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, involves a collaboration between the Federation of the French Cancer Centres (FNCLCC), the 20 French Regional Cancer Centres, some French public university and general hospitals and private Clinics and medical scientific societies. Its main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on a literature review followed by a critical appraisal by a multidisciplinary group of experts to produce the draft guidelines which are then validated by specialists in cancer care delivery. OBJECTIVES: To develop clinical practice guidelines for hospital catering for cancer patient using the methodology developed by the Standards, Options and Recommendations project. METHODS: Data were identified by a literature search of Medline and the reference lists of experts in the groups. After the guidelines were drafted, they were validated by independent reviewers. RESULTS: The main recommendations are: 1) While taking into consideration the specific needs of cancer patients, the dietician is responsible for the hygiene, the sanitary quality of alimentation, the equilibrium and nutritional quality of the hospital catering. 2) Ordering and distribution of meals, and clearing up afterwards contribute to the quality of hospital catering and the personnel who do this should have time and be willing to listen to the patients. 3) The ordering of meals should be adapted to individual patient's requirements and must take into account the patient's medication. 4) The method of transporting the food chosen by the institution (cold or warm method) should be respected. The personnel responsible should receive regular and specific training to use the method correctly. 5) The intake of patients with nutritional follow-up should be reliably and reproducibly evaluated by the personnel after every meal. 6) Patient satisfaction should be assessed once a year and the results of this assessment used to improve the quality of hospital catering. 7) The dietician is the interface between the accounts department, the medical wards, the hospital catering department and the patients.

Adult↗
PubMed2000

Three-dimensional knee analyzer validation by simple fluoroscopic study.

Introduction: The complexity of the knee articulation makes its clinical evaluation extremely difficult. Insufficiency of existing instruments for knee evaluation prevents physicians from providing a diagnosis of injury and/or an evaluation of different treatments. To this end, our research group has developed a functional knee analyzer, which allows a three-dimensional evaluation of the knee in motion. The goal of this study is to scientifically validate the functional knee analyzer before using it in clinical setting. Materials and methods: The three-dimensional knee analyzer includes an orthoplastic exoskeleton attachment system, a kinematic tracking device, a screen for graphical display and a C(++) program with a user interface for calculating kinematic indices. A fluoroscopic study was performed on five healthy subjects with a mean age of 28. The experiment was set-up to determine the reduction of skin movement with respect to the underlying bone by using a knee exoskeleton attachment system. The root mean square (RMS) errors of markers movement about the abduction-X (RMSRx) and tibial rotation-Z (RMSRz) axes and displacement in the XZ plane (RMSpxpz) were calculated, once by placing markers directly on the skin and once on the exoskeleton attachment system. Results: Our results demonstrated that RMSpxpz, RMSRx and RMSRz were reduced by a factor of 6 (min 1.8, max 26), 4.3 (min 0.75, max 21) and 6.2 (min 2, max 26.4) on average, respectively, for four subjects out of five when the exoskeleton attachment was used.

Journal Article↗
PubMed2000

Patient satisfaction needs as related to knee stability and objective findings after ACL reconstruction using the LARS artificial ligament.

The purposes of this study are to compare patient satisfaction with the objective measurement of knee stability and assess early complications following ACL reconstruction using a LARS artificial ligament. Forty-seven patients were reviewed 8-45 months after surgery. Assessment was made by the Knee and Osteoarthritis Outcome Score for patient satisfaction, a modified International Knee Documentation Committee form for clinical knee stability, and a Telos stress radiography for PA stability. Complications were assessed at interview and were double-checked with charts. The LARS artificial ligament may be a safe device to reconstruct an ACL tear. Documenting mechanical stability of the knee is inadequate when reporting follow-up studies and a questionnaire assessing patient satisfaction should be added to provide a better picture of the outcome and results.

Journal Article↗
PubMed2000

Pharmacological profile of SL 59.1227, a novel inhibitor of the sodium/hydrogen exchanger.

1. The NHE1 isoform of the Na(+)/H(+) exchanger plays an important role in the regulation of intracellular pH and in cardiac cell injury caused by ischaemia and reperfusion. SL 59.1227 is a novel imidazolypiperidine Na(+)/H(+) antiport inhibitor which is structurally unrelated to previously described acylguanidine inhibitors such as cariporide. 2. Recovery of pH(i) following an intracellular acid load was measured in CCL39-derived PS120 variant cells, selectively expressing either NHE1 or NHE2 isoforms of the Na(+)/H(+) exchanger. pH(i) recovery was potently and selectively slowed by SL 59.1227 in NHE1-expressing cells (IC(50) 3.3+/-1.3 nM) versus NHE2-expressing cells (2.3+/-1.0 microM). The respective IC(50) values for cariporide were 103+/-28 nM (NHE1) and 73+/-46 microM (NHE2). 3. In anaesthetized rats following left coronary artery occlusion (7 min) and reperfusion (10 min) SL 59.1227 (10 - 100 microg kg(-1) min(-1) i.v.) inhibited ischaemia-mediated ventricular tachycardia (71 - 100%) and reperfusion-induced ventricular fibrillation (75 - 87%) and prevented mortality. Bolus i.v. administration of SL 59.1227 (1 mg kg(-1)) produced anti-arrhythmic effects when administered either before or during ischaemia. 4. Cardiac infarct size was determined in anaesthetized rabbits following left coronary artery occlusion (30 min) and reperfusion (120 min). Infarct size measured as a percentage of the area at risk was 36.2+/-3.4% (control group) versus 15.3+/-3.9% (SL 59.1227 0.6 mg kg(-1) i.v.). 5. SL 59.1227 is the first example of a potent and NHE1-selective non-acylguanidine Na(+)/H(+) exchanger inhibitor. It possesses marked cardioprotective properties.

Animals↗
PubMed2000

Quality of life and home enteral tube feeding: a French prospective study in patients with head and neck or oesophageal cancer.

A prospective study was conducted to evaluate the impact of home enteral tube feeding on quality of life in 39 consecutive patients treated for head and neck or oesophageal cancer at the Centre François Baclesse in Caen, France. Patients were taken as their own controls. Quality of life was evaluated using the EORTC QLQ-C30 core questionnaire, and the EORTC H&N35 and OES24 specific questionnaires. The feeding technique tolerance was evaluated using a questionnaire specifically developed for this study. Two evaluations were made, the first a week after hospital discharge (n = 39) and the second 3 weeks later (n = 30). Overall, the global health status/quality of life scale score slightly improved; among symptoms, scale scores that significantly improved (P < 0.05) concerned constipation, coughing, social functioning and body image/sexuality. The physical feeding technique tolerance was acceptable while the technique was psychologically less tolerated with two-thirds of the patients longing to have the tube removed. One third of the patients was also uncomfortable about their body image. Home enteral tube feeding was responsible for not visiting family or close relations in 15% of patients, and not going out in public in 23%. We conclude that home enteral tube feeding is a physically well accepted technique although a substantial proportion of patients may experience psychosocial distress.

Adult↗
PubMed2000

[Good clinical practice in the dietetic management of cancer patients].

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centres (FNCL CC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feed-back from specialists in cancer care delivery. OBJECTIVES: To develop clinical practice guidelines according to the definitions of Standards, Options and Recommendations for the dietetic consultation for cancer patient. METHODS: Data have been identified by literature search wing Medline and the expert groups personal reference lists. Once the guidelines were defined, the document was submitted for review to 74 independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: The main recommendations for the referral of cancer patients for dietary advice are: I) in oncology, there are 3 types of dietetic consultation: diagnostic, preventive and therapeutic; 2) the following cancer patients must have a dietetic consultation: i) those with, or at risk of malnutrition, ii) those without malnutrition but in need of counseling and iii) those at risk of treatment-related nutritional side effects; 3) a nutritional assessment is standard at the time of the first dietetic consultation. Patients must be given individualized and written advice; 4) the dietetic opinion and advice should be brought to the attention of medical staff to facilitate a multidisciplinary approach to cancer treatment; 5) patient's relatives should be involved in the dietetic management; 6) the efficacy of dietetic advice can be assessed by monitoring weight, gastrointestinal signs and patient satisfaction.

Adult↗
PubMed1999

Abnormal regulation of urokinase plasminogen activator by insulin-like growth factor 1 in human osteoarthritic subchondral osteoblasts.

OBJECTIVE: Subchondral bone sclerosis is a common feature of osteoarthritis (OA), but the mechanisms responsible for this condition remain unresolved. We investigated the role of insulin-like growth factor 1 (IGF-1) and urokinase plasminogen activator (uPA) in human osteoblasts from subchondral bone obtained from the tibial plateaus of OA patients and normal individuals. METHODS: Primary in vitro osteoblasts were prepared from subchondral bone specimens obtained from OA patients at surgery and from normal individuals at autopsy. Levels of uPA and PA inhibitor 1 (PAI-1) levels were determined under basal conditions and after IGF-1 stimulation in conditioned media from osteoblasts by enzyme-linked immunosorbent assay. The activity of uPA was evaluated by specific substrate hydrolysis and zymography under basal conditions and after plasminogen stimulation, in the presence and absence of added IGF-1. Plasmin activity was also evaluated by specific substrate hydrolysis. RESULTS: Levels of uPA released by OA osteoblasts were significantly higher than normal. Addition of IGF-1 to osteoblasts significantly reduced uPA protein levels only in OA patients (P < 0.05). In contrast, the addition of uPA to osteoblasts did not modify IGF-1 levels in either normal or OA osteoblasts. Basal uPA activity was higher in OA than in normal osteoblasts. Interestingly, IGF-1 enhanced basal uPA activity in OA specimens in a dose-dependent manner. Addition of plasminogen promoted uPA activity in both normal and OA osteoblasts via a positive feedback loop due to plasmin generation, since this activity was inhibited by both PAI-1 and alpha2-antiplasmin. Unexpectedly, incubation with IGF-1 inhibited this positive feedback of plasminogen-dependent uPA activity in OA osteoblasts, but not in normal osteoblasts, in a dose-dependent manner. Hence, normal osteoblasts were relatively insensitive to IGF-1, whereas the same treatment reduced both uPA levels and plasminogen-dependent uPA activity in OA osteoblasts while it increased basal uPA activity in OA osteoblasts. This could not be explained by PAI-1 protein levels, which were similar in normal and OA osteoblasts in the presence and absence of IGF-1. IGF-1 also reduced plasmin activity in OA osteoblasts while it did not modify this activity in normal osteoblasts. CONCLUSION: These results suggest that in OA osteoblasts, the uPA/plasmin system functions normally, yet IGF-1 inhibits the positive feedback of plasmin on uPA activity. This inhibition may contribute to abnormal IGF-1- and uPA-dependent bone remodeling, ultimately leading to abnormal bone sclerosis in OA.

Aged↗
PubMed1999

[Mechanical evaluation of a ligament fixation system for ACL reconstruction at the tibia in a canine cadaver model].

OBJECT: Excellent fixation of an artificial ligament in bone is mandatory for initial stability. ACL reconstruction with the LARS artificial ligament may fail if anchorage to bone is inadequate. The weak metaphyseal bone of the proximal tibia is prone to inadequate fixation. This study evaluates the initial mechanical stability of two techniques with an interference screw on the tibial side of an ACL reconstruction with the LARS ligament. METHODS: Six left tibias were obtained from 1 to 3 year old mongrel dog weighing 20 to 26 kg. ACL straight line reconstruction according to the technique described by J.P. Laboureau was performed with a 4.5 mm drill. Two tunnels were created in the tibia, one oblique and one transverse, the latter 2 cm below the former. Reconstruction was done with a 30-fiber LARS ligament and a 5.2 mm x 15 mm conical titanium cannulated interference screw. Group I had an interference screw in the oblique tunnel and group II had an interference screw in the transverse tunnel. Pull-out tests were performed parallel to the oblique tunnel on an Instron 8521 machine at a speed of 5 mm per minute until failure. The oblique tunnel was tested first then the transverse tunnel. RESULTS: Group I (n = 6): sliding value = 238 +/- 115 N. Group II (n = 6): sliding value = 998 +/- 148 N. This is statistically significant (p < 0.001, student t-test). CONCLUSION: One interference screw in a transverse tibial tunnel for ACL reconstruction with the LARS ligament is 4 times more resistant on loading and impact than an oblique screw.

Animals↗
PubMed1999

A new factor Xa inhibitor (lefaxin) from the Haementeria depressa leech.

The salivary complex of the leech Haementeria depressa produces potent anticoagulant components. Among them, a protein named lefaxin inhibits factor Xa (FXa). Lefaxin was purified to homogeneity from dissected salivary complexes by gel filtration in Sephadex G-150 followed by two ion exchange chromatography steps in Mono-Q. Inhibition of FXa by lefaxin was demonstrated by the inhibition of its amidolytic activity, measured with chromogenic substrate S-2765 (apparent K(I) of 4 nM), and of its ability to inhibit thrombin generation in the prothrombinase complex (EC50 of 40 nM). Lefaxin has a molecular weight of 30 kDa and an isoelectric point of 5.7. It is made of a polypeptide chain whose N-terminal sequence shows no similarity with that of other FXa inhibitors (antistasin and ghilianten) isolated from leech saliva. On the other hand, the N-terminal sequence of lefaxin presents significant sequence similarity with nitric oxide carrier proteins myohemerythrin from the annelid Nereis diversicolor and prolixin S from the triatoma Rhodnius prolixus. Interestingly, prolixin S also proved to be an anticoagulant protein acting on FXa.

Amino Acid Sequence↗