Bone sialoprotein-induced reparative dentinogenesis in the pulp of rat's molar

Bone sialoprotein (BSP), an osteogenic protein (OP), mixed with a carrier, was implanted in the pulp of rat first upper molars (OP group). Cavities were prepared with dental burs and pulp perforation was carried out by pressure with the tip of a steel probe. After 8, 14, and 30 days, the rats were killed and the pulps of the OP group were compared with (1) a sham group (S group), (2) a group where the carrier was implanted alone (C group), and (3) capping with calcium hydroxide (Ca group). After 8 days, a few inflammatory cells were seen, mostly located at the pulp surface near the perforation. In the Ca group, a dentin bridge started to form, in contrast to the other groups. After 15 days, globular structures were seen in the pulps of the S and C groups. A reparative osteodentin bridge isolated the pulp from the cavity in the Ca group. Variable reactions were seen in the OP group, with some evidence of cell and matrix alignments or plugs of osteodentin in continuity with an inner layer of reparative dentin. After 30 days, irregular osteodentin formation was observed in the pulps of the S and C groups, with a tendency for globular structures to merge, but with interglobular spaces filled by pulp remnants. In the Ca group, osteodentin was observed in the mesial part of the pulp chamber. In the BSP-implanted group, the osteogenic protein stimulated the formation of a homogeneous dentin-like deposit occupying most of the mesial part of the pulp. Apparently, BSP stimulates the differentiation of cells which secrete an organized extracellular matrix more efficiently than any other capping material used so far. Altogether, the results reported here support that bone sialoprotein displays novel bioactive properties and is capable of stimulating in 1 month's time the development of a thick reparative dentinal tissue in the pulp, occluding the perforation and filling the mesial third of the pulp chamber.

Dermal regeneration template for deep hand burns: clinical utility for both early grafting and reconstructive surgery

Adequate acute treatment of the deeply burned hand and any subsequent reconstructive procedures may be hampered by the lack of sufficient suitable graft material and the risks of donor site morbidity and scarring. This investigation was designed to determine the feasibility of treating deep hand burns using a dermal regeneration template. Patients with deep hand burns underwent either acute treatment or reconstructive procedures with Integra dermal regeneration template. Wound sites were first grafted with the dermal regeneration template, and then 2-3 weeks later after neodermis formation the silicone layer of the Integra was removed and a very thin split-thickness epidermal autograft placed. Acute grafting was performed on 15 hands in 11 patients and reconstructive surgery on 14 hands in 11 patients. Median follow-up was 12 months. Integra take was 100% on all treated hands. After acute grafting the wound site skin was flexible and supple and did not adhere to the deeper layers, thus permitting free articular and functional movement. Cosmetic results of acute surgery were judged satisfactory by both patients and surgeons. After reconstructive procedures, significant improvements were achieved in cosmetic status, based on Vancouver Scar Scale (p=0.0002), and in three measures of function, namely, thumb opposition score (p=0.0005), fingertip-to-palm distance (p=0.0039) and prehensile score (p=0.0039). Favourable cosmetic and functional outcomes were consistently attained using a synthetic dermal regeneration template for treatment of deep hand burns either by acute grafting or reconstructive surgery.

Static pressure-volume curves and effect of positive end-expiratory pressure on gas exchange in adult respiratory distress syndrome

Fifteen patients with adult respiratory distress syndrome (ARDS) were studied: 11 in the early stage of ARDS (group 1); 4 in the late stage (group 2). The inspiratory and expiratory static pressure-volume (P-V) curves of the respiratory system were compared to the pulmonary shunt (Qsp/Qt) when PEEP was increased; cardiac output was kept constant. In group 1 patients, we found that a concavity on the P-V curves was associated with an abrupt decrease in Qsp/Qt when PEEP was increased; the concavity on the expiratory curve was correlated with the change in Qsp/Qt but not the concavity on the inspiratory curve. In group 2 patients, the P-V curves were found rectilinear and Qsp/Qt was not abruptly decreased when PEEP was increased. Expiratory P-V curve can be used to determine: first, whether a patient should be ventilated with PEEP; second, the PEEP level which can be set on the respirator. In group 1 patients, when PEEP was set to a value corresponding to the inflexion point, i.e., the point of departure from the exponential shape (mean value 14.6 +/- 2.8 cm H2O), Qsp/Qt compared to zero PEEP was abruptly decreased to 87.6 +/- 6%; further increase in PEEP had little advantage.

Selective inhibition of inducible nitric oxide synthase reduces neurological deficit but not cerebral edema following traumatic brain injury

The role of inducible nitric oxide synthase (iNOS) in cerebral edema and neurological deficit following traumatic brain injury (TBI) is not yet clear-cut. Therefore, the aim of this study was to investigate the effect of three different iNOS inhibitors on cerebral edema and functional outcome after TBI. First, the time courses of blood--brain barrier (BBB) breakdown, cerebral edema, and neurological deficit were studied in a rat model of fluid percussion-induced TBI. The permeability of BBB to Evans blue was increased from 1 h to 24 h after TBI. Consistently, a significant increase in brain water content (BWC) was observed at 6 and 24 h post-TBI. A deficit in sensorimotor neurological functions was also observed from 6 h to 7 days with a maximum 24 h after TBI. Second, a single dose of aminoguanidine (AG; 100 mg/kg, i.p.), L-N-iminoethyl-lysine (L-NIL; 20 mg/kg, i.p.), or N-[3-(aminomethyl)benzyl]acetamide (1400W; 20 mg/kg, s.c.) was administered at 6 h post-TBI. Treatment with AG reduced by 71% the increase in BWC evaluated at 24 h, while L-NIL and 1400W had no effect. In contrast, the three iNOS inhibitors reduced the neurological deficit from 30% to 40%. Third, 1400W (20 mg/kg, s.c.) was administered at 5 min, 8 and 16 h post-TBI. Although this treatment paradigm had no effect on cerebral edema evaluated at 24 h, it significantly reduced the neurological deficit and iNOS activity. In conclusion, iNOS contributes to post-TBI neurological deficit but not to cerebral edema. The beneficial effect of iNOS inhibitors is not due to their anti-edematous effect, and the reduction of cerebral edema by AG is unlikely related to iNOS inhibition. The 6 h therapeutic window of iNOS inhibitors could allow their use in the treatment of functional deficit at the acute phase of TBI.

Percutaneous tracheostomy by forceps dilation: report of 162 cases

A prospective, observational clinical study evaluated the safety of percutaneous single-step dilatational tracheostomy over a 43-month period. One hundred and sixty-two patients were deemed suitable for the procedure. The mean duration of tracheal intubation prior to tracheostomy was 6 days. The mean duration of the procedure was 9.3 min. Intra-operative complications occurred in 27 patients (16.6%), most of which were minor technical difficulties without morbidity. Postoperative complications, some of which were associated with morbidity, occurred in 16 patients. There were two deaths secondary to premature decannulation, one case of severe bleeding and five pneumothoraces. Long-term complications were assessed in 81 patients; there were four tracheal stenoses requiring surgery or laser therapy and seven patients with granulation tissue at the stoma site which did not require treatment. Forceps dilatational percutaneous tracheostomy appeared to be a convenient bedside procedure. However, complications do occur and further studies should address late sequellae, such as tracheal stenosis.

Detrimental Role of Bradykinin B2 Receptor in a Murine Model of Diffuse Brain Injury

Inhibition of the bradykinin B2 receptor type (B2R) has been shown to improve neurological outcome in models of focal traumatic brain injury. However, the involvement of B2R in trauma-induced diffuse injury has not yet been explored. This is an important point, since in humans a pattern of diffuse injury is commonly found in severely injured patients and has been associated with a poor neurological outcome and prognosis. Using the non-peptide B2R antagonist LF 16-0687 Ms and B2R null (B2R-/-) mice, we investigated the role of B2R in a model of closed head trauma (CHT). LF 16-0687 Ms given 30 min after injury reduced the neurological deficit by 26% and the cerebral edema by 22% when evaluated 4 h after CHT. Neurological function after CHT was improved in B2R-/- mice compared to B2R+/+ mice, although there was no difference in the development of brain edema. Treatment with LF 16-0687 Ms and B(2)R gene deletion decreased the accumulation of neutrophils at 24 h after CHT (50% and 36%, respectively). In addition, the inducible NO synthase (iNOS) mRNA level increased markedly, and this was reduced by LF 16-0687 Ms. Taken together, these data support a detrimental role of B2R in the development of the neurological deficit and of the inflammatory secondary damage resulting from diffuse traumatic brain injury. Therefore, blockade of bradykinin B2 receptors might represent an attractive therapeutic approach in the pharmacological treatment of traumatic brain injury.

[Integra, a new surgical alternative for the treatment of massive burns. Clinical evaluation of acute and reconstructive surgery: 39 cases]

Early excision and prompt coverage in severely burned patients are the best way to lessen morbidity and improve survival. Repair of full-thickness burns requires replacement of both dermal and epidermal components of skin and treatment with split thickness autografts replaces both of them. But healthy skin is not sufficient in extensive burns. Alternative to split thickness skin grafts have been studied by several groups including epidermis, dermis or a complete replacement comprising epidermis and dermis. Because of the difficulties in homografts supplying, a new way was use to replace the dermis. In 1981, Yannas and Burke were the first to develop such a matrix. Intégra is available in France since 1997 and was used in our service for the treatment of both acute and reconstructive surgery for burned patients. Twenty patients were treated for acute surgery. Nineteen patients were treated for reconstructive surgery of burn scar contractures. Fifty-one grafts of Intégra were performed. Long-term final results seem to show that Intégra improve cosmetical and functional results and is a new surgical alternative for the treatment of burns in the acute phase as well as in late surgery of deformities.

Apoptotic mitochondrial pathway in neurones and astrocytes after neonatal hypoxia-ischaemia in the rat brain

Neuronal apoptosis plays an essential role in early brain development and contributes to secondary neuronal loss after acute ischaemia. Recent studies have provided evidence that caspase-3 is an important downstream event after hypoxia-ischaemia in the immature brain, but a minor event in the adult brain. Our investigations have focused on cell populations that expressed apoptotic effectors in the enzymatic death pathway including cytochrome c, caspase-9 and caspase-3. Expression, activation and cellular localization of these proteins were studied using cleavage of fluorogenic substrate and immunohistochemistry in neonatal rat brain after unilateral focal ischaemia. Caspase-3 enzyme activity was elevated in brain homogenate between 6 and 48 h after reperfusion. This activation was preceded by that of caspase-9, between 3 and 24 h. Apoptotic cell death was finally accomplished by poly-ADP-ribose polymerase cleavage, an endogenous caspase-3 substrate. In addition, immunodetection demonstrated that cytochrome c and activated caspase-9 and caspase-3 were expressed not only in the neurones, the primarily affected cells, but also within the astrocytes, which constituted a dense network delineating the infarct. These results suggested that glial injury may promote the formation of cystic lesions such as those observed clinically in the newborn brain.

The concept of damage control: extending the paradigm in the prehospital setting

OBJECTIVE

The purpose of this review is to present the progressive extension of the concept of damage control resuscitation, focusing on the prehospital phase.

ARTICLE TYPE

Review of the literature in Medline database over the past 10 years.

DATA SOURCE

Medline database looking for articles published in English or in French between April 2002 and March 2013. Keywords used were: damage control resuscitation, trauma damage control, prehospital trauma, damage control surgery. Original articles were firstly selected. Editorials and reviews were secondly studied.

DATA SYNTHESIS

The importance of early management of life-threatening injuries and rapid transport to trauma centers has been widely promulgated. Technical progress appears for external methods of hemostasis, with the development of handy tourniquets and hemostatic dressings, making the crucial control of external bleeding more simple, rapid and effective. Hypothermia is independently associated with increased risk of mortality, and appeared accessible to improvement of prehospital care. The impact of excessive fluid resuscitation appears negative. The interest of hypertonic saline is denied. The place of vasopressor such as norepinephrine in the early resuscitation is still under debate. The early use of tranexamic acid is promoted. Specific transfusion strategies are developed in the prehospital setting.

CONCLUSION

It is critical that both civilian and military practitioners involved in trauma continue to share experiences and constructive feedback. And it is mandatory now to perform well-designed prospective clinical trials in order to advance the topic.

Prospective randomized comparison of progressive dilational vs forceps dilational percutaneous tracheostomy

This trial prospectively compares two methods of percutaneous tracheostomy, both routinely used in ICU: the Ciaglia progressive dilational tracheostomy and the Griggs forceps dilational tracheostomy. One hundred patients were randomized using a single-blinded envelope method to receive progressive or forceps percutaneous tracheostomy performed at the bedside. Operative time, the occurrence of hypoxaemia or hypercapnia and complications were recorded. The progressive technique took longer than the forceps technique (median 7 (range 2-26) vs. 4 (1-16) minutes, P = 0.0005). Hypercapnia occurred in both groups but was more marked with the progressive technique (56 (16) vs. 49 (13) mmHg, P = 0.0082). Minor complications (minor bleeding, transient hypoxaemia, damage to posterior tracheal wall without emphysema) were also more frequent with the progressive technique (31 vs. 9 complications, P < 0.0001). Six major complications occurred with the progressive technique, none with the forceps technique (P = 0.0085): tension pneumothorax, posterior tracheal wall injury with subcutaneous emphysema, loss of airway with hypoxaemia, loss of stoma with impossible re-catheterization, and two conversions to another technique. In conclusion, progressive dilational tracheostomy took longer, caused more hypercapnia and more minor and major difficulties than forceps dilational tracheostomy.

Pattern of cerebral edema and hemorrhage in a mice model of diffuse brain injury

This study aims to examine the time course of the brain edema formation in relation with blood-brain barrier (BBB) disruption and cerebral hemorrhage in a murine model of diffuse brain injury. Brain water content increased at 1 h post-injury and persisted up to 7 days. This event was associated with electrolyte imbalance such as Na(+) increase within 24 h. Prominent Evans blue extravasation was also observed from 1 to 6 h post-injury. Concurrently, hemoglobin increased markedly by 1 h, reached a peak at 4 h and declined progressively within a week in association with a rise of parenchyma iron content between 24 h and 7 days. These results suggest that brain edema is vasogenic and that the hemorrhage process is involved in the BBB disruption and edema, both leading to post-traumatic secondary events.

Platelet-derived growth factor stimulates phospholipase C-gamma 1, extracellular signal-regulated kinase, and arachidonic acid release in rat myometrial cells: contribution to cyclic 3',5'-adenosine monophosphate production and effect on cell proliferation

In the present study, we examined downstream signaling events that followed exposure of cultured rat myometrial cells to platelet-derived growth factor (PDGF) and their effect on cell proliferation. PDGF-BB induced tyrosine phosphorylation of PDGF-beta receptors and increased inositol trisphosphate production via the tyrosine phosphorylation of phospholipase (PL)C-gamma 1. PDGF-BB also increased cAMP synthesis. This increase was potentiated by forskolin and reduced by indomethacin, a cyclooxygenase inhibitor, reflecting a Gs protein-mediated process via prostaglandin biosynthesis. The prostaglandin produced by PDGF was characterized as prostacyclin (PGI(2)). PDGF-BB increased arachidonic acid (AA) release, which, similarly to cAMP accumulation, was abolished in the presence of AACOCF3, a cytosolic PLA(2) inhibitor, and in the absence of Ca(2+). U-73122, a potent inhibitor of PLC activity, blocked both the production of inositol phosphates and the AA release triggered by PDGF-BB. Extracellular signal-regulated kinases (ERKs) 1 and 2 are expressed in myometrial cells, and PDGF-BB selectively activated ERK2. PD98059, an inhibitor of the ERK-activating kinase, blocked PDGF-BB-mediated ERK2 activation, AA release, and cAMP production. The results demonstrate that PDGF-BB stimulated cAMP formation through both PLC activation and ERK-dependent AA release and PGI(2) biosynthesis. PDGF-BB also increased cell proliferation and [(3)H]thymidine incorporation. This was abolished by PD98059, demonstrating that the ERK cascade is required for the mitogenic effect of PDGF-BB. Forskolin, which potentiated the cAMP response to PDGF-BB, attenuated both DNA synthesis and ERK activation triggered by PDGF-BB, suggesting the presence of a negative feedback regulation.

Pervanadate mediated an increased generation of inositol phosphates and tension in rat myometrium. Activation and phosphorylation of phospholipase C-gamma 1

Stimulation of [3H]inositol-labeled rat myometrial strips with pervanadate, formed by mixing orthovanadate and H2O2, induced a dose-dependent accumulation of [3H]inositol phosphates. Orthovanadate or H2O2 added alone had no effect. Pretreatment of myometrium with two tyrosine kinase inhibitors, namely genistein and tyrphostin 47 (at 100 microM), reduced pervanadate-stimulated inositol phosphate formation by 50%. Pervanadate induced a time-sequential formation of inositol phosphates in the order inositol trisphosphate, inositol bisphosphate, and inositol monophosphate. The inhibitory effect of genistein was observed at the level of the three inositol phosphates. Pervanadate induced contraction of the myometrium; the response was dose-dependent. H2O2 or orthovanadate was without effect. Pervanadate-mediated contraction was inhibited (50%) by genistein and tyrphostin 47 (100 microM). Western blot analysis, using anti-phosphotyrosine antibodies, revealed that phosphorylated proteins were present in detergent extracts from pervanadate-stimulated myometrium. Tyrosine phosphorylation was reduced by a preincubation with 100 microM genistein or tyrphostin 47. Phospholipase C-gamma1 was immunodetected in myometrial extracts and was identified as one of the substrates subject to tyrosine phosphorylation following pervanadate treatment. The results demonstrate that, in myometrium, protein tyrosine kinase/phosphatase activities controlled both phosphorylation and activation of phospholipase C-gamma1, contributing to the modulation of the generation of inositol phosphates and tension.

Rapid reversal of global left ventricular dysfunction after accidental injection of 0.75 mg epinephrine in a 20-year-old patient

We report an accidental injection of epinephrine before spinal anaesthesia in a 20-year-old patient who subsequently developed immediate myocardial ischemia and global left ventricular dysfunction (ejection fraction of 20%). Hemodynamic status dramatically improved after nitroglycerin, calcium antagonists, acetyl salicylic acid and unfractionated heparin injections. Over 24 h, patient's ejection fraction fully recovered without kinetic abnormality.

Effects of hypothermic deep-anaesthesia on energy metabolism at brain and peripheral levels: a multi-probe microdialysis study in free-moving rat

Reduction of central energy metabolism is a strategy to protect brain against neurotoxic events. The aim of this microdialysis study in rats is to evaluate changes in energy metabolite levels at central level (striatum) comparatively to peripheral level (subcutaneous adipose tissue) during hypothermic barbituric deep-anaesthesia (sodium pentobarbital 60 mg/kg intraperitoneally). At brain level, extracellular glucose increases (+14.9%) while lactate decreases (-16.6%); opposite results were observed at subcutaneous level (-29.2% for glucose and +68.3% for lactate). Lactate/pyruvate ratio remains unchanged at brain level, but increases at subcutaneous level (+73.5%). In light of previous studies on the effects of pentobarbital on regional blood flow and tissue glucose consumption, our data correlates the fact that pentobarbital reduces preferentially brain energetic metabolism. We suggest that those regional effects are explained, at least for a part, by the fact that central isoform glucose transporters (Glut1 and Glut3) are known to be more sensitive to pentobarbital than peripheral isoforms. Such facts can be involved in the protection of brain tissue against ischemic risk due to decreased cerebral blood flow decrease.

Inositol hexasulphate, a casein kinase inhibitor, alters enamel formation in cultured embryonic mouse tooth germs

Post-translational modification of enamel proteins is regulated by casein kinases (CK) and results in binding sites for calcium ions that subsequently play a key role during the initial stages of mineralization. Phosphorylation may also influence the secretion and extracellular organization of enamel proteins. Previous studies indicated that inositol hexasulphate inhibited the activity of CK-I and/or CK-II in mouse tooth germs (Torres-Quintana et al., 1998). We hypothesized that inositol hexasulphate would also inhibit the activity of the specific casein kinase(s) identified in secretory ameloblasts, and would prove useful for determination of the extent to which phosphorylation might influence the organization of enamel proteins at early stages of enamel formation. To test this hypothesis, we dissected mandibular first molars from 18-day-old mouse embryos and cultured them for 11 days in the presence of 0-0.1 mM inositol hexasulphate. Ultastructural analysis revealed that the formation of enamel was largely impaired at an inhibitor concentration > or = 0.08 mM. Quantitative radioautographic analysis of [33P]phosphate incorporation indicated that radiolabeled phosphate normally secreted into forming enamel was retained within ameloblasts. In contrast, no significant difference was observed between control and inositol-hexasulphate-treated tooth germs when cultures were labeled with [3H]serine and [3H]proline. SDS-PAGE and Western blot analysis confirmed that while inositol hexasulphate inhibited CK-mediated phosphorylation, it did not significantly alter protein synthesis. We conclude that impairment of phosphorylation leads to intracellular accumulation of [3H]phosphate-containing material by ameloblasts. We also conclude that when non-phosphorylated enamel matrix proteins are secreted, they are either unable to form an enamel matrix that supports mineralization, or they diffuse throughout a poorly mineralized dentin.

[Isolated acquired factor VII deficiency in patient with severe head trauma: use of factor VII (factor VII-LFB]

We report a case of transient acquired and isolated factor VII deficiency associated with severe head trauma. A 16-year-old boy was involved in a motor vehicle accident. CT scan showed frontal brain contusion and a cerebral haematoma (5 cm). First prothrombine time (PT) was normal. Rapidly, a severe coagulopathy developed, unresponsiving to fresh frozen plasma and vitamin K. Haemostatic markers analysis showed an isolated deficiency of factor VII at 15%. No inhibitory activity against factor VII could be detected. We successfully treated the deficiency with intermittent intravenous human factor VII (factor VII-LFB) during 10 days. Factor VII return to normal at 84%. Physiopathological and therapeutic aspects of this rare pathology are presented.

Les potentiels évoqués cognitifs, auditifs et somesthésiques dans les comas : valeur pronostique pour l’éveil et la réintégration socioprofessionnelle

OBJECTIVE

To appreciate prognostical value of event-related potentials in comatose states and the influence of the stimulation's modality.

PATIENTS AND METHODS

Thirty-five patients were recorded with the auditory modality whose thirteen were also recorded with the somesthetic modality. They were free of sedation except for five. For 21 patients out of coma, it was possible to get information about their social readaptation 14 months later.

RESULTS

When present, cognitive components predict awakening in 100 % of the cases, but only 50 % of the patients who awake had these components. The somesthetic modality seemed to enlarge their detection, but did not improve short-term forecasts. We could not confirm their absence could hamper social reinstatement.

CONCLUSION

Event-related potentials are strengthened as having excellent positive prognostic value. Further studies should clarify the interest of the somesthetic modality, and the possibility to get remote prognostic.