Arterial vascularization of the mandible and soft tissues. Anatomic study.

PURPOSE: The literature has for too long described the arterial supply of the mandible as coming from a single artery, the inferior alveolar artery, and being of the terminal type. Rather, it appears to come from an extensive and complex arterial network dependent on the lingual, facial, and maxillary arteries and their collateral branches. Our study aims to confirm and demonstrate the arterial vascular richness of the mandible and to establish arterial mapping. METHODS: The arterial vascularization of the mandible was revealed in six anatomic specimens after performing selective injections of the lingual, facial, and maxillary arteries with different dyes. A specimen was injected intra-arterially with colored latex at the level of the maxillary artery for a morphometric study. RESULTS: Eighteen selective arterial injections were performed on six anatomic specimens. The mucocutaneous, musculoperiosteal, and intramedullary vascularizations were analyzed. Each of the arteries has a defined and delimited cutaneo-mucous vascular territory. The facial and maxillary arteries supply the musculoperiosteal vascularization of the mandible from the condyle to the symphysis. The lingual artery supplies only the inner cortex of the parasymphyseal and symphyseal regions. The facial and maxillary arteries provide intramedullary vascularization from the angle of the mandible to the parasymphysis. The vascularization of the symphysis depends on the facial artery. No staining was found in the condyle region. Neoprene latex injection was performed on an anatomic specimen, revealing a permeable anastomosis between the inferior alveolar and facial arteries. CONCLUSION: The arterial vascularization of the mandible is dependent on the maxillary, facial, and lingual arteries. This is a network vasculature. This study makes it possible to establish an arterial map of the mandible. The presence of an anastomosis between the inferior alveolar artery and the facial artery confirms the existence of dynamic and borrowed vascularization. Knowledge of this arterial system makes it possible to adapt maxillofacial surgical care and to anticipate possible intraoperative complications.

Long-term results with biosynthetic absorbable P4HB mesh in ventral abdominal wall repair: a multicentre analysis.

BACKGROUND: The aim of this multicentre study was to analyse the outcomes of biosynthetic absorbable poly-4-hydroxybutyrate (P4HB) prosthesis implantation in patients undergoing ventral hernia repair (VHR) in the context of different degrees of contamination. METHODS: From May 2016 to December 2021, a multicentre retrospective analysis of patients who underwent elective or urgent hernia repair with P4HB prosthesis was performed in seven hospitals in Spain and Portugal. Patients with a postoperative follow-up of less than 20 months and those within the theoretical period of prosthesis resorption were excluded from the study. Regarding the degree of contamination, patients were assessed according to the modified Ventral Hernia Working Group (VHWG) classification. Epidemiological data, hernia characteristics, surgical and postoperative variables (Clavien-Dindo classification) of these patients were analyzed. Risk factors related to long-term recurrence were studied by a multivariate analysis. RESULTS: In 236 cases of P4HB prosthesis implantation, repair in cases of Grade 3 was the most frequent (49.1%), followed by Grade 2 in 42.3% of cases and Grade 1 in 8.4%. The most frequent complications were Grade 1, with the majority occurring during the first year. The overall rate of surgical site occurrences (SSO) was 30%. The hernia recurrence rate was 14.4% (n = 34), with a mean postoperative follow-up time of 41 months (22-61). The multivariate analysis showed that the onlay location of the mesh (OR 1.07; CI 1.42-2.70, p = 0.004) was a significant independent risk factor for recurrence. CONCLUSIONS: The use of a P4HB bioresorbable mesh for the VHR with different degrees of contamination leads to favourable results overall, with an acceptable rate of hernia recurrence. The onlay location of the P4HB prosthesis is the main factor in recurrence in both elective and emergency settings.

Evidence for a recessive PMP22 point mutation in Charcot-Marie-Tooth disease type 1A.

Charcot-Marie-Tooth disease type 1A (CMT1A) is an autosomal dominant neuropathy that can be caused by dominant point mutations in PMP22 which encodes a peripheral nerve myelin protein. Usually, CMT1A is caused by the duplication of a 1.5-megabase (Mb) region on chromosome 17p11.2-p12 containing PMP22. Deletion of a similar 1.5-Mb region is associated with hereditary neuropathy with liability to pressure palsies (HNPP), a clinically distinct neuropathy. We have identified a severely affected CMT1 patient who is a compound heterozygote for a recessive PMP22 point mutation, and a 1.5 Mb deletion in 17p11.2-p12. A son heterozygous for the PMP22 point mutation had no signs of neuropathy, while two others heterozygous for the deletion had HNPP, suggesting that point mutations in PMP22 can result in dominant and recessive alleles contributing to CMT1A.

Effect of Smoking Exposure on Nonsurgical Periodontal Therapy: 1-Year Follow-up.

This study investigated the influence of different levels of exposure to smoking on periodontal healing for 12 mo after nonsurgical periodontal therapy and supportive periodontal care every third month. Eighty smokers willing to quit smoking and with periodontitis were included. Participants were offered an individualized voluntary smoking cessation program. Data collection included questionnaires and a full-mouth periodontal examination. Group-based trajectory modeling was used to model smoking trajectories over the follow-up. The effect of smoking trajectory on periodontal parameters over time was estimated with mixed effects modeling. Three smoking patterns were identified: light smokers/quitters (n = 46), moderate smokers (n = 17), and heavy smokers (n = 17). For the periodontal data, the first factor, moderate periodontitis, included the number of sites with clinical attachment levels (CALs) of 4, 5, 6, and 7 mm; periodontal pocket depths (PPDs) of 4, 5, and 6 mm; and bleeding on probing. The second factor, severe periodontitis, consisted of the number of sites with a CAL ≥8 mm and PPD ≥7 mm. Heavy smokers commenced with a higher average CAL of 1.1 mm and 10 more sites with severe periodontitis than light smokers/quitters. While light smokers/quitters and moderate smokers obtained an average improvement of 0.6-mm PPD and 0.7-mm CAL, respectively, heavy smokers experienced 0.5-mm attachment loss. Heavy smokers had only a 50% reduction in the number of sites with moderate periodontitis when compared with light smokers/quitters and moderate smokers. While most participants benefited from nonsurgical periodontal therapy with results affected in a dose-response manner, the therapy had no effect on severe periodontitis among heavy smokers. Smoking cessation should be part of periodontal therapy; otherwise, limited benefits would be observed among heavy smokers, hindering the effect of treatment.

Influence of Taper surface topographies on contact deformation and stresses.

The role of bore and trunnion surface topography on the failure rate of total hip joint replacements due to trunnionosis is not clear despite significant variations in the design of taper components between manufacturers. Taper surface topography, along with other taper design parameters such as clearance, diameter, and assembly force, determine the initial interlock of the contacting surfaces after assembly; this has been related to relative motions that can cause fretting and corrosion at the taper interface. However, in most in-silico parametrical taper studies associated with taper micromotions, the bore and trunnion surfaces have been simplified using a flat surface and/or sinusoidal functions to mimic the surface roughness. The current study tests the hypothesis that the use of simple geometrical functions for the taper surface topography can predict the surface mechanics developed in assembled tapers. Measured and simulated surfaces of bores and trunnions were characterised using common roughness parameters and spectral density estimations. Using the same characterised surface profiles, 2D Finite Element (FE) models of CoCr alloy femoral heads and Ti alloy trunnions were developed. Models simulated assembly conditions at different resultant forces ranging from 0.5 to 4.0 kN, contact conditions were determined and associated with their topographical characteristics. Measured surfaces of bore and trunnion components comprise up to seven dominant spatial frequencies. Flattening of the trunnion microgrooved peaks was observed during the assembly of the taper. When the femoral head bore and trunnion topography were both considered a reduced number of microgrooved peaks were in contact, from 51 in an idealised taper surfaces to 35 in measured surfaces using an assembly reaction force of 4 kN. The contact points in the models developed high plastic strains, which were greater than that associated with failure of the material. Results showed that line and sine wave functions over estimate contact points at the taper interface compared to those surfaces that consider roughness and peak variation. These findings highlight the important role of modelling the full surface topography on the taper contact mechanics, as surface variations in the roughness and waviness change the performance of tapers.

[A novel miniplate model for maxillary osteotomies]. / Nouveau modèle de miniplaques pour les ostéotomies maxillaires.

INTRODUCTION: The use of miniplates in orthognatic surgery, and especially for Le Fort I osteotomies, has brought great improvement in technical aspects, postoperative evolution, and long-term stability. Nevertheless, accurate modelling of theses plates remains problematic because the right balance between malleability and rigidity is hard to determine. This is why we designed an original new miniplate model. The aim of this study was to assess our new model in clinical settings. MATERIAL AND METHOD: This novel plate was made of two lateral sockets with two holes on each side, linked by a central bar, 1mm thick like the plate. Three lengths were available. A mechanical study proved that this plate was stronger than a 0.6 millimeter thick plate and that its adaptability was much superior to that of a common 1-mm thick plate. We retrospectively studied 180 patients having undergone a Le Fort I osteotomy with or without mandibular osteotomy. Follow-up ranged from 6 to 12 months. Congenital abnormalities were excluded. RESULTS: Bone healing was achieved without any complication in due time for all but two patients. In one case, a plate fracture was observed. In the other case, a slight mobility of the upper jaw appeared after removal of the device. No intolerance was observed. DISCUSSION: This novel miniplate seems to be improved when compared to other available devices. Rigid osteosynthesis of a Le Fort I osteotomy can be problematic because of the repositioning gap and the variable anatomy of the maxilla. The device must be rigid enough, inconspicuous, and well tolerated. Only three plate lengths are necessary to treat all cases, which reduces cost and storage. The only requirement is to mandatorily insert four plates every time. Removal of the plates does not seem necessary.

Development of the mandibular condylar cartilage in human specimens of 10-15 weeks' gestation.

This study analyses some morphological and histological aspects that could have a role in the development of the condylar cartilage (CC). The specimens used were serial sections from 49 human fetuses aged 10-15 weeks. In addition, 3D reconstructions of the mandibular ramus and the CC were made from four specimens. During weeks 10-11 of development, the vascular canals (VC) appear in the CC and the intramembranous ossification process begins. At the same time, in the medial region of the CC, chondroclasts appear adjacent to the vascular invasion and to the cartilage destruction. During weeks 12-13 of development, the deepest portion of the posterolateral vascular canal is completely surrounded by the hypertrophic chondrocytes. The latter emerge with an irregular layout. During week 15 of development, the endochondral ossification of the CC begins. Our results suggest that the situation of the chondroclasts, the posterolateral vascular canal and the irregular arrangement of the hypertrophic chondrocytes may play a notable role in the development of the CC.

Chemical transformations in individual ultrasmall biomimetic containers.

Individual phospholipid vesicles, 1 to 5 micrometers in diameter, containing a single reagent or a complete reaction system, were immobilized with an infrared laser optical trap or by adhesion to modified borosilicate glass surfaces. Chemical transformations were initiated either by electroporation or by electrofusion, in each case through application of a short (10-microsecond), intense (20 to 50 kilovolts per centimeter) electric pulse delivered across ultramicroelectrodes. Product formation was monitored by far-field laser fluorescence microscopy. The ultrasmall characteristic of this reaction volume led to rapid diffusional mixing that permits the study of fast chemical kinetics. This technique is also well suited for the study of reaction dynamics of biological molecules within lipid-enclosed nanoenvironments that mimic cell membranes.

Regulation of PGLYRP1 and TREM-1 during Progression and Resolution of Gingival Inflammation.

INTRODUCTION: The triggering receptor expressed on myeloid cells 1 (TREM-1) signaling pathway is stimulated by bacteria and, together with its putative ligand peptidoglycan recognition protein 1 (PGLYRP1), propagates proinflammatory responses. OBJECTIVES: We aimed to evaluate the TREM-1/PGLYRP1/interleukin (IL)-1ß regulation in response to biofilm accumulation and removal in an experimental human gingivitis model. METHODS: The study (n = 42 participants, mean age: 23.8 ± 3.7 y) comprised a recruitment step (day -14) followed by experimentally induced biofilm formation (induction [I] phase, day 0 to +21) and a 2-wk resolution (R) phase (day +21 to +35). Plaque was recorded by the Modified Quigley and Hein Plaque Index (TQHPI), while records of gingival inflammation were based on the Modified Gingival Index (MGI). Unstimulated whole saliva supernatants (n = 210, 5 time points) were tested for TREM-1, PGLYRP1, and IL-1ß by enzyme-linked immunosorbent assay. RESULTS: During the I-phase, concentrations of all analytes showed a tendency for downregulation at day +7 compared to day 0. TREM-1 (P = 0.019) and PGLYRP1 (P = 0.007) increased significantly between day +7 and day +21. Although all analyte levels decreased during the R-phase, the difference was not significant except TREM-1 being at borderline significance (P = 0.058). Moreover, TREM-1, PGLYRP1, and IL-1ß showed significant positive correlations (P < 0.0001) with each other. The study participants were grouped into "fast" and "slow" responders based on clinical gingival inflammation scores. At each time point, fast responders showed significantly higher concentrations of TREM-1 (P < 0.025), PGLYRP1 (P < 0.007), and IL-1ß (P < 0.025) compared to slow responders. Mixed-effects multilevel regression analyses revealed that PGLYRP1 (P = 0.047) and IL-1ß (P = 0.005) showed a significant positive association with the MGI scores. CONCLUSION: The study demonstrated that TREM-1 and PGLYRP1 are regulated in response to biofilm accumulation and removal, and fast responders demonstrated higher levels of these analytes compared to slow responders. KNOWLEDGE TRANSFER STATEMENT: The results of this study demonstrated the suitability of salivary TREM-1 and PGLYRP1 to reflect biofilm accumulation and removal and PGLYRP1 to monitor the progression and resolution of inflammation in gingivitis-susceptible individuals (fast responders). Combined with conventional risk factors, the molecular toolbox proposed here should be further validated in future studies to confirm whether it can be used for population-based monitoring and prevention of gingivitis.

Quantification of pegylated phospholipids decorating polymeric microcapsules of perfluorooctyl bromide by reverse phase HPLC with a charged aerosol detector.

Polyethylene glycol (PEG) chains covalently linked to phospholipids are often used in the preparation of lipid or even polymer colloidal particles to avoid recognition and clearance by the reticuloendothelial system and to increase their plasmatic half-life. To the best of our knowledge, no direct method allows yet to quantify these pegylated phospholipids. The aim of this work was to develop a method for the quantification of a typical pegylated phospholipid, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000], DSPE-PEG2000, associated to polymeric microcapsules of perfluorooctyl bromide (PFOB). Reverse phase high-performance liquid chromatography (HPLC) was used, coupled with a corona charged aerosol detection (HPLC-CAD). Calibrations standards consisted of plain microcapsules and pegylated phospholipids (DSPE-PEG2000) in the concentration range of 2.23-21.36 microg/mL (0.22-2.14 microg injected). Calibration curve was evaluated with two different model, linear and power model. The power model describes experimental values better than the linear model, for pegylated phospholipids with the CAD detector. The correlation coefficient for the power model was 0.996, and limits of detection and quantification obtained were 33 and 100 ng, respectively. This method proved to be selective and sensitive; the accuracy of the method ranged from 90 to 115% and the relative standard deviation was

[An electro-stimulating oral splint for dry mouth treatment].

Dentists encounter regularly patients with xerostomia, which is the accepted term for dry mouth complaint. Left untreated, xerostomia can lead to psychosocial distress and to impaired quality of life. Oral complications of the most frequent cause of xerostomia, salivary gland hypofunction, include dental caries and candidiasis. In addition, quality of life is significantly hampered. The etiology of xerostomia is multiple, but the most common conditions are Sjögren's syndrome, radiotherapy to the head and neck and use of medications. Current therapies offered by dentists rely on saliva substitutes and stimulants such as chewing gum, and are somewhat limited by their short-term efficacy. Oral mucosal electro-stimulation increases salivary secretion and relieves symptoms of dry mouth in patients with xerostomia. Therefore, intra-oral electronic devices have been developed aimed at stimulating salivary gland function. They offer promise as an optional safe and non-chemical treatment of xerostomia.

Value of PET/CT 3D visualization of head and neck squamous cell carcinoma extended to mandible.

PURPOSE: To study an original 3D visualization of head and neck squamous cell carcinoma extending to the mandible by using [18F]-NaF PET/CT and [18F]-FDG PET/CT imaging along with a new innovative FDG and NaF image analysis using dedicated software. The main interest of the 3D evaluation is to have a better visualization of bone extension in such cancers and that could also avoid unsatisfying surgical treatment later on. PATIENTS AND METHODS: A prospective study was carried out from November 2016 to September 2017. Twenty patients with head and neck squamous cell carcinoma extending to the mandible (stage 4 in the UICC classification) underwent [18F]-NaF and [18F]-FDG PET/CT. We compared the delineation of 3D quantification obtained with [18F]-NaF and [18F]-FDG PET/CT. In order to carry out this comparison, a method of visualisation and quantification of PET images was developed. This new approach was based on a process of quantification of radioactive activity within the mandibular bone that objectively defined the significant limits of this activity on PET images and on a 3D visualization. Furthermore, the spatial limits obtained by analysis of the PET/CT 3D images were compared to those obtained by histopathological examination of mandibular resection which confirmed intraosseous extension to the mandible. RESULTS: The [18F]-NaF PET/CT imaging confirmed the mandibular extension in 85% of cases and was not shown in [18F]-FDG PET/CT imaging. The [18F]-NaF PET/CT was significantly more accurate than [18F]-FDG PET/CT in 3D assessment of intraosseous extension of head and neck squamous cell carcinoma. This new 3D information shows the importance in the imaging approach of cancers. All cases of mandibular extension suspected on [18F]-NaF PET/CT imaging were confirmed based on histopathological results as a reference. CONCLUSIONS: The [18F]-NaF PET/CT 3D visualization should be included in the pre-treatment workups of head and neck cancers. With the use of a dedicated software which enables objective delineation of radioactive activity within the bone, it gives a very encouraging results. The [18F]-FDG PET/CT appears insufficient to confirm mandibular extension. This new 3D simulation management is expected to avoid under treatment of patients with intraosseous mandibular extension of head and neck cancers. However, there is also a need for a further study that will compare the interest of PET/CT and PET/MRI in this indication.

Oral health impact of periodontal diseases in adolescents.

The need for treatment of destructive periodontal diseases is based on observations made by oral health professionals, who, prompted by clinical findings, recommend treatment. We hypothesized that clinical signs of periodontal destruction have an impact on the oral-health-related quality of life of adolescents. We conducted a cross-sectional study among 9203 Chilean high school students sampled by a multistage random cluster procedure. We recorded clinical attachment levels and the presence of necrotizing ulcerative gingivitis. The students answered the Spanish version of the Oral Health Impact Profile and provided information on several socio-economic indicators. The results of multivariable logistic regression analyses (adjusted for age, gender, and tooth loss) showed that both attachment loss [OR = 2.0] and necrotizing ulcerative gingivitis [OR = 1.6] were significantly associated with higher impact on the Oral Health Related Quality of Life of adolescents. Individuals in lower socioeconomic positions systematically reported a higher impact on their oral-health-related quality of life.

Relationship between facial nerve damage and transbuccal trocar placement: an anatomical cohort study.

The surgical treatment of ramus and mandibular angle fractures is typically performed by intraoral and transbuccal approaches. As these approaches may result in nerve damage, this anatomical study was performed to establish the relationship between the transbuccal trocar position and the likelihood of inducing facial nerve damage. Twenty dissections of the parotid regions were performed after a simulation of surgical approaches aimed at addressing mandibular condylar and angle fractures. Two trocar tubes, ramic and angular, were inserted and left in position throughout the dissection. This procedure allowed the qualitative relationship between the various tube positions and facial nerve damage to be analyzed. The potential risk of contact between the ramic trocar and the facial nerve branches was 90%, while the angular trocar was in contact in 45% of cases. There was no contact with the trunk, cervicofacial division, or temporofacial division of the facial nerve. The contacts occurred at the level of secondary division branches, particularly pronounced for superior and inferior buccal branches, despite the absence of macroscopically visible trauma. Based on these findings, it is proposed that trocars should be used in procedures aimed at addressing subcondylar or angle fractures of the mandible.

Role of adrenergic and cholinergic mediators in salivary phospholipids secretion.

The influence of adrenergic and cholinergic mediators on phospholipid secretion in rat sublingual salivary gland cells maintained in the presence of [3H]choline was investigated. The secretion of [3H]choline-containing phospholipids over 30 min period averaged 1.93% of the total cellular labeled phospholipids in the absence of any mediator, and was enhanced by beta-adrenergic agonist, isoproterenol, to a greater extent than the cholinergic agonists, pilocarpine and carbachol. A 2.9-fold increase in phospholipid secretion occurred with isoproterenol, while pilocarpine and carbachol evoked only 1.3-fold increase. The effect of isoproterenol was inhibited by alprenolol and that of pilocarpine and carbachol by atropine. In contrast to pilocarpine and carbachol, the enhanced phospholipid secretion due to isoproterenol was accompanied by an increase in cAMP concentration. The secretion of phospholipids was also stimulated by dibutyryl-cAMP and the protein kinase C activator, phorbol myristate acetate, but not by 4 alpha-phorbol 12,13-didecanoate which does not activate protein kinase C. Furthermore, the effects of dibutyryl-cAMP and phorbol myristate acetate were additive. The phospholipids secreted in response to isoproterenol exhibited a 52% decrease in lysophosphatidylcholine, while those secreted in response to pilocarpine and carbachol showed a 21-23% lower content of phosphatidylcholine, and were enriched in lysophosphatidylcholine (2.6-2.8-fold) and sphingomyelin (1.5-1.6-fold). The results indicate that salivary phospholipid secretion remains mainly under beta-adrenergic regulation, while the phospholipid makeup of the secretion is under cholinergic control.

Maxillofacial intraoral distraction osteogenesis followed by elastic traction in cleft maxillary deformity.

We present a case of severe maxillary hypoplasia in a 16 years old cleft patient treated by distraction osteogenesis maxillary advancement. Initial evaluation showed vertical and antero-posterior maxillary deficiencies, and a Class III malocclusion. Two intraoral distractors (Zurich Pediatric Maxillary Distractor, KLS Martin, Tuttlingen, Germany) were placed in a high Le Fort I osteotomy. An initial advancement of 11 mm was obtained, but the resulting occlusion was unsatisfactory (end-to-end occlusion). The consolidation period was reduced to 3 weeks to allow the mechanical manipulation of the newly formed bone with Class III elastics. An additional advancement of 3 mm, caused by elastic orthodontic traction produced both normal skeletal relationship and satisfactory occlusion. This observation shows that it is possible to carry on a skeletal maxillary displacement by interdental elastics before the complete fusion of the callus. After 12 months of postoperative follow-up no osseous relapse could be detected and the occlusal result was stable.

[Juvenile production of the red sea urchin Strongylocentrotus franciscanus (Echinodermata: Echinoidea) in Baja California, Mexico]. / Producción de juveniles de erizo rojo Strongylocentrotus franciscanus (Echinodermata: Echinoidea) en Baja California, México.

The red sea urchin Strongylocentrotusfranciscanus (Agassiz 1863) is harvested commercially in Baja California, Mexico, since 1970; however, in the last ten years the capture per unit effort (CPUE) has decreased from 310 kg/fishing unit/day to 120 kg/fishing unit/day. For this reason, actions were taken to develop a culture technology allowing massive production of juveniles for re-stocking natural populations or for growing them commercially. We summarize some of the basic studies and main achievements in this effort. In Baja California, considerably faster larval development (approximately 21 days) has been attained than in the US northwest coast (62 days). Spawning of red sea urchins was routinely induced with KCI while egg fertilization was performed using a 100,000-sperm/ml solution. Six microalgae species were tested and Rhodomonas sp. produced the best larval development. The mean survival rate at the end of the larval period was 25%, but results varied widely with bactch. From the feed ratios tested, best results were obtained using 7000 cel/ml during the first week of larval development, followed by 10,000 cel/ml during the second and 15,000 cel/ml during the third week. KCl proved the most consistent metamorphic inducer, regularly yielding metamorphosis percentages higher than 90%. Metamorphosis was considered complete when the functional jaw that juveniles use for first benthic feeding appeared (as soon as 20 days after induction). With this method several thousands of red sea urchin juveniles were produced. They reached up to 1.5 mm in size during the first 50 days of culture after metamorphosis, showing the great potential for mass production of this species in the laboratory.

Fine tuning of magnetite nanoparticle size distribution using dissymmetric potential pulses in the presence of biocompatible surfactants and the electrochemical characterization of the nanoparticles.

The effects of varying the surfactant concentration and the anodic pulse potential on the properties and electrochemical behaviors of magnetite nanoparticles were investigated. The nanoparticles were synthesized with an electrochemical method based on applying dissymmetric potential pulses, which offers the advantage that can be used to tune the particle size distribution very precisely in the range of 10 to 50 nm. Under the conditions studied, the surfactant concentration directly affects the size distribution, with higher concentrations producing narrower distributions. Linear voltammetry was used to characterize the electrochemical behavior of the synthesized nanoparticles in both the anodic and cathodic regions, which are attributed to the oxidation of Fe(2+) and the reduction of Fe(3+); these species are part of the spinel structure of magnetite. Electrochemical impedance spectroscopy data indicated that the reduction and oxidation reactions of the nanoparticles are not controlled by the mass transport step, but by the charge transfer step. The sample with the highest saturation magnetization was that synthesized in the presence of polyethylene glycol.

Enhanced oral cyclosporine absorption with water-soluble vitamin E early after liver transplantation.

We evaluated the effect of Liqui-E, a water-soluble vitamin E preparation, on cyclosporin A (CyA) whole blood concentration in liver transplant recipients, and its impact on the cost of CyA. Patients were 26 liver transplant recipients (19 adults, 7 children) who were unable to achieve and maintain therapeutic CyA whole blood concentrations with the standard recommended oral daily dose in the early post-transplant period. Liqui-E 6.25 IU/kg orally was administered with CyA every 12 hours (median time of starting Liqui-E day 14.5). With Liqui-E, the daily oral CyA requirements (mean +/- SD) were decreased in adults from 22.6 +/- 8.9 to 16.2 +/- 7.3 mg/kg/day (p < 0.001) and in children from 78.6 +/- 34.1 to 53.7 +/- 35.0 mg/kg/day (p < 0.02); intravenous administration of CyA was unnecessary. The CyA trough concentrations (mean +/- SD) before and after Liqui-E were 670 +/- 186 and 1012 +/- 216 ng/ml, respectively, in adults (p < 0.001) and 732 +/- 187 and 1052 +/- 166 ng/ml, respectively, in children (p < 0.01). When given with Liqui-E, the daily cost of CyA decreased by 26% in both adults and children. No clinical or biochemical evidence of Liqui-E toxicity was observed. Thus its administration in the early post-transplantation period can enhance CyA absorption in adults and children who are unable to achieve adequate whole blood concentrations with the usual recommended oral dosages. In addition, a significant cost saving can be realized by coadministration.