Veränderungen der freien Thrombozytennukleotide beim Sanarelli-Shwartzman-Phänomen

Beim Sanarelli-Shwartzman-Phänomen des Kaninchens findet man neben anderen Gerinnungsstörungen auch eine verminderte Retraktionsfähigkeit des Blutes. Ursache hierfür ist ein Verlust von energiereichem Phosphat (ATP) in den Thrombozyten, welches offenbar mit anderen Nukleotiden die geschädigten Plättchen verläßt. Es kann dabei eine quantitative Beziehung zwischen dem ATP-Gehalt der Plättchen und dem m-Wert des TEG nachgewiesen werden. Für die Thrombozytenschädigung wird intravasal auftretendes Thrombin verantwortlich gemacht, welches die viskose Metamorphose startet, die Permeabilität verändert und so die Blutplättchen zum Untergang vorbereitet. Quantitative und qualitative Plättchenveränderungen sind die Folge. Freiwerdende Plättchen- lipide gehen im Rahmen der Thrombokinasefunktion des Blutes in den ubiquitären intravasalen Gerinnungsprozeß ein. Die konsekutive Thrombozytopathie bzw. experimentelle “Thrombasthenie” bietet gewissermaßen im Modell weitere Ansatzpunkte für Thrombozytenstudien.

Über die Wirkung von Lipidemulsionen auf Blutplättchen

In vorliegenden Untersuchungen konnte gezeigt werden, daß zahlreiche Lipid-Wasser-Emulsionen zu einer ausgeprägten und rasch einsetzenden Steigerung der Thrombozytenaggregation führen. Bei Abwesenheit von Kalziumionen in EDTA-Plasma ließ sich ein Lipideffekt an Thrombozyten nicht mehr nachweisen. Mehrfach gewaschene Plättchen zeigten jedoch auch ohne Kalziumionen eine deutliche Steigerung der Aggregation. Bei 4° C war der Ablauf der Aggregation deutlich verlangsamt. Die Zugabe von Albumin oder EPL verhinderte die aggregationssteigernde Wirkung einer Lipidemulsion. Adenosin führte lediglich zu einer teilweisen Hemmung der lipid -induzierten Klebrigkeitssteigerung. Aufgrund der Ergebnisse wird vermutet, daß der erste Schritt der Wirkung einer Lipidemulsion auf Thrombozyten mit der Oberflächenaktivität der Emulsionsteilchen in ursächlichem Zusammenhang steht. Im weiteren Verlauf kommt es zu einer Phagozytose von Lipidemulsionsteilchen durch Thrombozyten, was mit einer Zunahme einer Aggregationsneigung und erheblichen morphologischen und biochemischen Veränderungen verknüpft ist.

Über die Wirkung von Lipidemulsionen auf Blutplättchen

Der Einfluß emulgierter Lipide (Fettsäuren, Triglyzeride, Lipidgemische) und fettähnlicher Substanzen (Paraffin- und Silikonöl) auf die Struktur der Blutplättchen von Mensch und Schwein wurde licht- und elektronenmikroskopisch untersucht. Es zeigte sich, daß die Emulsionsteilchen aller geprüften Substanzen von den Plättchen durch Membraninvagination, wie das bei phagozytierenden Zellen bekannt ist, aufgenommen werden. Daneben beobachteten wir eine vermutlich ADP-induzierte Neigung der Plättchen zu aggregieren, die durch Adenosin gehemmt wurde. Emulsionen mit hohem Anteil unveresterter Fettsäuren oder reine Fettsäureemulsionen führten darüber hinaus zu starken Destruktionen der Plättchen, während nach Behandlung mit Triglyzeriden oder Lipidgemischen ohne freie Fettsäuren diese Erscheinungen erst nach langen Inkubationszeiten auftraten und sich vermindern ließen, wenn die intraplasmatische Lipolyse durch Protaminsulfat gehemmt wurde. Der Zusatz von Emulgatoren (Albumin, Phospholipide) setzte die Fettsäurewirkung und die Aggregationsneigung der Plättchen herab, EDTA verhinderte die Aggregatbildung völlig. Aus den Beobachtungen schließen wir, daß für die Aufnahme von Lipiden die Eigenschaften der Emulsionsteilchen bestimmend sind, während freie Fettsäuren aufgrund ihrer Moleküleigenschaften die Plättchenmembranen passieren und in hohen Konzentrationen zur Zellzerstörung führen.

Surgically assisted rapid palatal expansion in class III malocclusion: Our experience

INTRODUCTION

Maxillary transverse deficiency (MTD) is a common facial disharmony that may need surgical assisted rapid palatal expansion (SARPE). The aim of this study was to present our SARPE technique and to report about our experience.

MATERIEL AND METHOD

Medical records of all class III patients who underwent SARPE in our department from 2010 to 2015 and for whom a follow-up of at least 1year was available, were included in a retrospective study. The technique consisted, after short orthodontic preparation allowing for divergence of the upper central incisors, in a complete Le Fort I osteotomy without down fracture, and medial sagittal submucosal separation of the hard palate under general anesthesia in an inpatient procedure. Teeth-supported distracters were sealed preoperatively while bone-supported devices were inserted peroperatively. Activation of the distracter was allowed from day 2 at the rate of 2×0.25 per day during 4days and 2×0.5mm per day the following days. Distracters were left in place for about 4months. Orthodontic treatment resumption was allowed from the second month. The initial malocclusion, the amount and type (parallel or angular) of distraction that was needed, the type of distracter used, the amount of distraction obtained, the per- and postoperative complications and the clinical stability of the end result were analyzed.

RESULTS

The records of 23 patients (18 women, 5 men - average age: 25.4years, extremes: 16-55years) could be included. MTD was isolated in 6 cases, associated with a maxillary retrognathism in 5 cases, with a mandibular prognathism in 6 cases, and with both in 6 cases. The average amount of distraction needed was 7.2mm (range: 4-12), parallel in 20 cases and angular in 3 cases. The distracters were bone-supported (Rapid Palatal Expander^®, KLS Martin Group, Tuttlingen, Germany) in 3 patients and custom-made tooth-supported in 20 patients. The average amount of distraction obtained at the level of the distracter cylinder was 7.7mm (range: 5-13). We noted 2 cases of palatal fibromucosa perforations, 1 case of posterior excess of distraction, 1 case of nasal septum deviation, 1 case of iatrogenic necrosis of tooth No.°11, 1 case of naso-genial sulcus hematoma, 1 case of intraoperative mobility of tooth No.°21, 5 cases of asymmetric distraction. Seventeen patients needed a second orthognathic procedure and 22 had stable Class I occlusion after removal of appliances at 18 months follow-up on average.

DISCUSSION

SARPE is a quite safe procedure that allows for transverse coordination without dental extraction. Transverse discrepancies greater than 4mm are for us clear indications for SARPE. When a sagittal discrepancy is associated, we prefer performing SARPE first and correcting the sagittal plane in a second operation. The recent development of Le Fort I sliding osteosynthesis plates opens the way to one time correction and the development of double-action distracters fitted out with 2 cylinders will be helpful for performing angular distractions.

Pulmonary lymphatic vessel morphology: a review

Our understanding of lymphatic vessels has been advanced by the recent identification of relatively specific lymphatic endothelium markers, including Prox-1, VEGFR3, podoplanin and LYVE-1. The use of lymphatic markers has led to the observation that, contrary to previous assumptions, human lymphatic vessels extend deep inside the pulmonary lobule, either in association with bronchioles, intralobular arterioles or small pulmonary veins. Pulmonary lymphatic vessels may thus be classified into pleural, interlobular (in interlobular septa) and intralobular. Intralobular lymphatic vessels may be further subdivided in: bronchovascular (associated with a bronchovascular bundle), perivascular (associated with a blood vessel), peribronchiolar (associated with a bronchiole), and interalveolar (in interalveolar septa). Most of the intralobular lymphatic vessels are in close contact with a blood vessel, either alone or within a bronchovascular bundle. A minority is associated with a bronchiole, and small lymphatics are occasionally present even in interalveolar septa, seemingly independent of blood vessels or bronchioles. The lymphatics of the interlobular septa often contain valves, are usually associated with the pulmonary veins, and connect with the pleural lymphatics. The large lymphatics associated with bronchovascular bundles have similar characteristics to pleural and interlobular lymphatics and may be considered conducting vessels. The numerous small perivascular lymphatics and the few peribronchiolar ones that are found inside the lobule are probably the absorbing compartment of the lung responsible for maintaining the alveolar interstitium relatively dry in order to provide a minimal thickness of the air-blood barrier and thus optimize gas diffusion. These lymphatic populations could be differentially involved in the pathogenesis of diseases preferentially involving distinct lung compartments.

Tendon healing induced by chemically modified mRNAs

Tendon disorders are frequent both in human and veterinary medicine with high re-injury rates and unsatisfactory therapeutic treatments. Application of naked, chemically-modified mRNA (cmRNA), encoding for therapeutic proteins, is an innovative approach to address tendon healing. In the current study, we demonstrated that injection of naked cmRNA, diluted in a glucose-containing solution, into tendons resulted in high protein expression in healthy and experimentally-injured tendons. Injection of bone morphogenetic protein 7 (BMP-7)-encoding cmRNA resulted in a significantly higher expression of BMP-7 protein and reduced formation of collagen type III, compared to vehicle control. Moreover, in a large animal model, reporter protein expression was detectable not only in healthy, but also in experimentally-injured, severely inflamed tendons. Summarising, these results demonstrated the potential of cmRNAs encoding for therapeutic proteins as a new class of drugs for the treatment of tendon disorders.

[Consequences of impacted wisdom teeth extraction on the periodontal environment of second molars. A pilot study]

INTRODUCTION

Wisdom teeth extraction is a common procedure, generally considered as safe by patients. However, complications are possible, especially periodontal ones. The aim of this study was to evaluate the frequency and the consequences of periodontal complications at the level the 2nd molars after extraction of the wisdom teeth.

MATERIAL AND METHODS

A single-center retrospective observational multi-operator study was conducted at the university hospital of Besançon - France. The files of all the adult patients who underwent extraction of four impacted wisdom teeth by mean of a standardized surgical technique between November 2012 and November 2014 and who could be followed 1 year postoperatively at least and that precisely mentioned the periodontal status of the surgical sites were included. Postoperative complications, gingival and plaque indexes according to Loë and Silness, periodontal attachment level and periodontal second molar probing were recorded. The main judgment criterion was the occurrence of a periodontal complication in the second molar areas.

RESULTS

The files of 20 patients (15 women - 5 men), operated on by five different surgeons, met the inclusion criteria. Two patients suffered from dry socket at one of the avulsion sites. No patient had a gingival or plaque index greater than 2. No gingival recession or periodontal pocket over 4mm was found.

DISCUSSION

Extraction of impacted third molars in young healthy adults didn't have any impact on the second molars periodontal environment in our study. Literature suggests that surgical technique greatly influences the occurrence and the extent of periodontal sequelae.

[Evaluation of healing time of osteochemonecrosis of the jaw after surgery: Single-center retrospective study and review of the literature]

INTRODUCTION

Osteochemonecrosis of the jaw (ONJ) is a chronic ischemic bone exposure. It has an increasing incidence. ONJ is mainly related to bisphosphonate and denosumab therapies in oncologic settings. Healing is considered uncertain ad as occurring slowly. International recommendations suggest to treat ONJ symptomatically in a first attempt. A surgical procedure, potentially aggressive, should be carefully weight up in patients in poor condition and whose life expectancy is often limited. However, surgical treatment seems to allow for a high rate of clinical remission. Postoperative remission periods, when mentioned in the studies, are disparate. The aim of our study was to clarify the remission period of ONJ after surgical management.

METHOD

A retrospective study was conducted on all patients operated for an ONJ at stage 2 and 3 in the Department for Oral and Maxillofacial Surgery - University Hospital of Besançon (France) from January 2006 to September 2015. Healing was defined as complete mucosal closure and asymptomatic site. Stage of the disease, the number and the type of surgery and the time between the last operation and the healing was noticed. These data were compared to an exhaustive review of the literature on PubMed with the following key-words: "osteonecrosis" AND "jaw" AND "surgery" AND "management". Only the articles giving the healing period were included.

RESULTS

Regarding the single-center retrospective study, the files of 23 patients could be included. Fifteen percent of the patients benefited from several procedures under general anesthesia. Twenty percent had a stage 3 ONJ and 80 % had a stage 2 ONJ. Twenty-five interventions were performed on 23 sites in 20 patients. Immediate healing after surgery occurred in 35 % of the patients. At 6 months after surgery, 57 % of the treated areas were healed. Twenty percent of the patients had died. The healing rate did not improve further after 6 months postoperatively. Regarding the review of the literature, 7 articles could be included. The mean postoperative healing period was 60.7 % at 6 months, 71.1 % at 12 months and 69.5 % at 18 months.

DISCUSSION

Our study shows that the postoperative healing rate of ONJ lies between 57 and 66.7 % at 6 months and that this rate was optimized in the order of 10 % to 12months and stable at 18months postoperatively. The ONJ of our series were partially or fully linked to other drugs than bisphosphonates in 70 % of the cases: 50 % were related to denosumab, alone or in combination and 35 % were related to an association with antiangiogenics, bevacizumab mainly.

[Treatment of a unilateral Brodie's syndrome by surgical contraction of the maxillae]

INTRODUCTION

Brodie's syndrome consists in a transverse occlusal discrepancy in relation with an excessive width of the maxilla, a narrow mandible or a combination of both, leading to lateral scissors bite. This kind of infrequent malocclusion is usually treated by orthodontics alone in children. In adults, additional orthognathic surgery id often required. We present a case of unilateral Brodie's syndrome treated by surgical contraction of the maxillae.

OBSERVATION

A 22-year-old patient presented with a left scissors bite and severe unilateral molar overbite. After failure of an attempt to ingress the left molars by help of a sub-apical corticotomy and anchorage mini-screws, the patient was referred for surgery. The mandible being considered as normal, a segmented Le Fort I osteotomy was planned, combining a contraction (4mm) and an impaction (4mm) of the left maxilla. This allowed for an immediate correction of the skeletal discrepancy and for the achievement of orthodontics in less than 6 months.

DISCUSSION

Le Fort I osteotomy provides a good access to the sagittal suture. Maxillary contraction is an uncommon procedure that enables a quick management of scissors bite and doesn't need any patient cooperation. Treatment time is reduced and the need for intraoral devices is limited.

Could MRI visualize the invisible? An Italian single center study comparing magnetic resonance lymphography (MRL), super microsurgery and histology in the identification of lymphatic vessels

OBJECTIVE

Aim of this study is to evaluate the possibility of limb magnetic resonance lymphography (MRL) to differentiate lymphatic vessels from pathological veins, collect a specimen of the identified lymphatic vessel during operations of super microsurgical lymphatic-venular anastomosis (s-LVA) and perform immunohistochemical stainings to confirm the nature of the collected vessels.

PATIENTS AND METHODS

Twenty patients presenting lymphedema were enrolled in this study. Five patients reported lower limb lymphedema and 15 patients reported upper limb lymphedema. All patients had the indication for s-LVA and underwent preoperative MRL imaging of the affected limb. A total of 57 lymphatic vessels were identified by MRL and used to guide s-LVA: all these vessels have also been used to perform an intraoperative biopsy for immunohistochemical evaluation.

RESULTS

A total of 53/57 vascular structures resulted compatible with lymphatic vessels at the immunohistochemical study performed with D2-40 antibody; 3/57 specimen showed the absence of the D2-40 antibody. A significant association was found between preoperative MRL and immunohistochemical marker D2-40 on collected specimen.

CONCLUSIONS

Most of the articles in the international literature report the concomitant presence of both lymphatic and venous vessels at MRL. However, no one in literature describes the possibility to differentiate venous vessels from lymphatic vessels, and this is a crucial issue for the correct evaluation of the lymphatic system in patients with limb lymphedema undergoing a future surgical correction. In the present study, MRL allowed to identify active lymphatic vessels. MRL was predictive to determine preoperatory lymphatic vessels and to perform successful s-LVA in lymphedema patients. This is the first study to prove the nature of the vessels identified at the preoperative MRL with immunohistochemical stainings.

[Arthrocentesis of the temporomandibular joint and intra-articular injections : An update]

INTRODUCTION

Arthocentesis of the temporomandibular joint combined with intra-articular washout and, more recently, intra-articular injection of pharmacological agents has been developed from the 1990s and is nowadays extensively in use for the treatment of temporomandibular dysfunctions (TMDs). The goal of our work was to answer 3 questions: 1. Is intra-articular washout effective for the treatment of TMDs ? 2. What kind of pharmacological agents may nowadays be injected in addition to washout and are these injections useful ? 3. What is the place of these treatments in the treatment strategies of TMDs ?

MATERIAL AND METHODS

A bibliographic research has been carried out in the PubMed database using following keywords arthrocentesis, temporomandibular joint. The 27 articles published between 1991 and 2016, indicating patient's inclusion criterions and objectively evaluating the clinical results (mouth opening, intra-articular noises, pain) were selected. Pharmacological agents were noticed when used.

RESULTS

1. All authors concluded to the efficacy of intra-articular washout. No prognostic factor for arthrocentesis efficacy could be identified. 2. Main pharmacological agents used were steroids, hyaluronic acid, morphine-based drugs and platelet rich plasma. Superiority of ith-injection protocols failed to win unanimous support. All authors who compared with- and without-injection protocols concluded to the superiority of with-injection protocols, whatever the agent.

DISCUSSION

Numerous studies have proven the efficacy of intra-articular washout for the treatment of TMDs resistant to noninvasive treatments. The advantage of any kind of pharmacological agent is not clear. Mechanisms of action are not all elucidated. No pharmacological agent showed any superiority over another. Study methodologies are often defective: imprecise inclusion criterions, short follow-up, confounding variables not taken into account, few comparison between pharmacological agents.

[Study of the normality of the orbito-naso-frontal bandeau]

INTRODUCTION

Craniosynostoses are cranio-facial malformations affecting about 1/2100 newborns in France. The involvement of anterior sutures (coronal and metopic) leads to orbito-frontal deformities. The treatment calls upon surgery the goal being, on an esthetic point of view, to restore a normal anatomy. The purpose of our work was to establish if some facial and/or frontal measures easy to perform on a CT are correlated to the global shape of the normal orbito-naso-frontal bandeau (ONFB).

MATERIAL AND METHOD

Cranial CTs of 123 consecutive non-malformed children aged between 4 and 12 months were selected in the database of Department of Radiology of the University Hospital of Besançon - France. The CTs were all relocated by rigid transformation in an orthonormal coordinate system. On each of the 123 CTs, 21 reproducible measures representative of the global shape of the ONFB were made. Statistical analyses of these measures were achieved, considering age and gender, in order to determine the correlation between each measure and the ONFB shape.

RESULTS

The only measure statistically correlated to the ONFB shape was the distance between the fronto-zygomatic sutures (FZD). The FZD was independent from age (in an interval of 4 months) and from gender. The 20 other measures did not show any correlation with age or gender.

DISCUSSION

The FZD allows in itself to determine the ONFB global shape. This measure, easily available on a CT, can help the surgeon to perform a customized reshaping of the ONFB. The development of a surgical template using this measure is ongoing.

[3D printing in health care facilities: What legislation in France?]

Health care facilities more and more use 3D printing, including making their own medical devices (MDs). However, production and marketing of MDs are regulated. The goal of our work was to clarify what is the current French regulation that should be applied concerning the production of custom-made MDs produced by 3D printing in a health care facility. MDs consist of all devices used for diagnosis, prevention, or treatment of diseases in patients. Prototypes and anatomic models are not considered as MDs and no specific laws apply to them. Cutting guides, splints, osteosynthesis plates or prosthesis are MDs. In order to become a MD manufacturer in France, a health care facility has to follow the requirements of the 93/42/CEE directive. In addition, custom-made 3D-printed MDs must follow the annex VIII of the directive. This needs the writing of a declaration of conformity and the respect of the essential requirements (proving that a MD is secure and conform to what is expected), the procedure has to be qualified, a risk analysis and a control of the biocompatibility of the material have to be fulfilled. The documents proving that these rules have been respected have to be available. Becoming a regulatory manufacturer of MD in France is possible for a health care facility but the specifications have to be respected.

Soil biota effects on local abundances of three grass species along a land-use gradient

Biotic plant-soil interactions and land-use intensity are known to affect plant individual fitness as well as competitiveness and therefore plant-species abundances in communities. Therefore, a link between soil biota and land-use intensity on local abundance of plant species in grasslands can be expected. In two greenhouse experiments, we investigated the effects of soil biota from grassland sites differing in land-use intensity on three grass species that vary in local abundances along this land-use gradient. We were interested in those soil-biota effects that are associated with land-use intensity, and whether these effects act directly or indirectly. Therefore, we grew the three plant species in two separate experiments as single individuals and in mixtures and compared their performance. As single plants, all three grasses showed a similar performance with and without soil biota. In contrast, in mixtures growth of the species in response to the presence or absence of soil biota differed. This resulted in different soil-biota effects that tend to correspond with patterns of species-specific abundances in the field for two of the three species tested. Our results highlight the importance of indirect interactions between plants and soil microorganisms and suggest that combined effects of soil biota and plant-plant interactions are involved in structuring plant communities. In conclusion, our experiments suggest that soil biota may have the potential to alter effects of plant-plant interactions and therefore influence plant-species abundances and diversity in grasslands.

[3D mandibular distraction planification in a case of severe temporomandibular ankylosis]

INTRODUCTION

When occurring in childhood, temporomandibular ankylosis joint is responsible for complex maxillofacial deformities, including mandibular growth deficiency. We present a case of temporomandibular joint ankylosis associated with severe mandibular asymmetry treated by mandibular bone distraction performed under computer assistance.

OBSERVATION

A 27-year-old patient presented with a severe facial asymmetry consisting in hypoplasia of the left hemi-mandible and maxilla. Mouth opening was non-existent. The CT-scan showed a left temporomandibular ankylosis. A left mandibular distraction was decided. The distraction characteristics (choice and positioning of the distractor, axis and amount of distraction) were determined preoperatively on the 3D CT-scan. The planning has been transferred to a navigation console (Kolibri®, Brainlab®). A combined intraoral and cutaneous was performed. Navigation allowed for an appropriate placement of the osteotomy line and fixation of the distractor. Distraction was started at the 5th postoperative day at the rate of 1mm per day and lasted 25 days without complication.

DISCUSSION

3D planning allows for better indication setting, better preparation of the procedure, reducing complications and operative time. It may help as an educational tool for young surgeons and for a better understanding from the patient. Navigation is an accurate method for the transfer of the planning in the operation room.