Complication of a columellar strut in an edentulous patient.

The cartilaginous columellar strut is a well established, commonly used graft in rhinoplasty which provides support and stability to the nasal base. The risk of such a graft is related to grafts designs, whereby the posterior aspect can cause clicking with movement across the anterior nasal spine. We present an additional unusual complication of ill-fitting maxillary dentures in an edentulous patient, previously not reported in the literature. This unique complication should alert facial plastic surgeons to use additional caution when sculpting columellar grafts in edentulous patients in order to avoid potential post-operative complications in this specific patient population.

Pharmacokinetic properties of 4-fluoroamphetamine in serum and oral fluid after oral ingestion.

INTRODUCTION: Each year, synthetic drugs occur in high numbers on the illicit drug market. But data on their pharmacology and toxicology are scarce. Therefore, a controlled study was performed to evaluate pharmacokinetic parameters of 4-fluoroamphetamine (4-FA) in humans and to compare it with effects. METHODS: Twelve subjects ingested 100 mg and five subjects also received 150 mg 4-FA in a bitter lemon drink. Blood and oral fluid samples were taken during the following 12 hours and analyzed for 4-FA and traces of amphetamine as impurity by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: For 12 hours after ingestion, the concentration-time course of 4-FA was similar to that of amphetamine with maximal concentrations appearing in serum after about 2 hours (in median 195 ng/mL after the 100 mg dose, range 155-316 ng/mL). The elimination half-life was approximately 8-9 hours and shorter than that of amphetamine but it exhibited a marked variation (5.5-16.8 hours). In oral fluid, 4-FA could also be detected for 12 hours and concentrations were higher than in serum. During the first 3 hours after ingestion concentrations were higher, most probably due to oral contamination. Serum concentrations in forensic cases were in the range of those observed in the present study suggesting dosages in recreational use in the range of those tested here. CONCLUSIONS: The pharmacokinetic properties of 4-FA are similar to that of amphetamine including a marked variation in elimination. However, recreational dosages may already exhibit prominent adverse effects and may even have life-threatening consequences.

3D-Printed Biodegradable Polymeric Vascular Grafts.

Congenital heart defect interventions may benefit from the fabrication of patient-specific vascular grafts because of the wide array of anatomies present in children with cardiovascular defects. 3D printing is used to establish a platform for the production of custom vascular grafts, which are biodegradable, mechanically compatible with vascular tissues, and support neotissue formation and growth.

The use of cementless expansion acetabular component and an alumina-polyethylene bearing in total hip arthroplasty for osteonecrosis.

We performed 114 consecutive primary total hip arthroplasties with a cementless expansion acetabular component in 101 patients for advanced osteonecrosis of the femoral head. The mean age of the patients at surgery was 51 years (36 to 62) and the mean length of follow-up was 110 months (84 to 129). The mean pre-operative Harris hip score of 47 points improved to 93 points at final follow-up. The polyethylene liner was exchanged in two hips during this period and one broken acetabular component was revised. The mean linear wear rate of polyethylene was 0.07 mm/year and peri-acetabular osteolysis was seen in two hips (1.9%). Kaplan-Meier analysis indicated that the survival of the acetabular component without revision was 97.8% (95% confidence interval 0.956 to 1.000) at ten years. Our study has shown that the results of THA with a cementless expansion acetabular component and an alumina-polyethylene bearing surface are good.

A randomised controlled trial of cemented and cementless femoral components for metal-on-metal hip resurfacing: a bone mineral density study.

The primary purpose of this study of metal-on-metal (MoM) hip resurfacing was to compare the effect of using a cementless or cemented femoral component on the subsequent bone mineral density (BMD) of the femoral neck. This was a single-centre, prospective, double-blinded control trial which randomised 120 patients (105 men and 15 women) with a mean age of 49.4 years (21 to 68) to receive either a cemented or cementless femoral component. Follow-up was to two years. Outcome measures included total and six-point region-of-interest BMD of the femoral neck, radiological measurements of acetabular inclination, neck-shaft and stem-shaft angles, and functional outcome scores including the Harris hip score, the Western Ontario and McMaster Universities Osteoarthritis Index and the University of California at Los Angeles activity scale. In total, 17 patients were lost to follow-up leaving 103 patients at two years. There were no revisions in the cementless group and three revisions (5%) in the cemented group (two because of hip pain and one for pseudotumour). The total BMD was significantly higher in the cementless group at six months (p < 0.001) and one year (p = 0.01) than in the cemented group, although there was a loss of statistical significance in the difference at two years (p = 0.155). All patient outcomes improved significantly: there were no significant differences between the two groups. The results show better preservation of femoral neck BMD with a cementless femoral component after two years of follow-up. Further investigation is needed to establish whether this translates into improved survivorship.

Collection of Oral Fluids Using Cotton Ropes as a Sampling Method to Detect Foot-and-Mouth Disease Virus Infection in Pigs.

In high-density farming practices, it is important to constantly monitor for infectious diseases, especially diseases that have the potential to spread rapidly between holdings. Pigs are known to amplify foot-and-mouth disease (FMD) by excreting large amounts of virus, and it is therefore important to detect the virus quickly and accurately to minimize the spread of disease. Ropes were used to collect oral fluid samples from pigs, and each sample was compared to saliva samples collected from individual animals by detecting FMD virus RNA using real-time PCR. Two different experiments are described where groups of pigs were infected with different serotypes of FMD virus, either with or without vaccination, and unvaccinated pigs were kept in aerosol contact. The sensitivity of the rope sampling varied between 0.67 and 0.92, and the statistical agreement between this method and individual sampling ranged from substantial to moderate for the two different serotypes. The ease of collecting oral fluids using ropes together with the high sensitivity of subsequent FMD detection through PCR indicates that this could be a useful method to monitor pig populations for FMD virus infection. With further validation of the sensitivity of detection of FMD virus RNA, this can be a cost-effective, non-invasive diagnostic tool.

Oligomeric assembly of thrombospondin in the endoplasmic reticulum of thyroid epithelial cells.

The thyroid endoplasmic reticulum (ER) provides an environment in which conformational maturation of thyroglobulin monomers occurs with progressive dissociation from BiP (a molecular chaperone), prior to thyroglobulin dimerization. This pattern of folding is thought to represent a pathway common to many exportable polypeptides. Thyrocytes also synthesize and secrete thrombospondin, an extracellular matrix glycoprotein that forms disulfide-linked trimers. Using a monoclonal antibody recognizing the N-terminal heparin-binding domain of thrombospondin, pulse-chase/immunoprecipitation experiments indicate that this epitope forms essentially cotranslationally. Dependent upon structural information contained within the N-terminal region, thrombospondin trimers also form and are rapidly stabilized by interchain disulfide bonds in the peritranslational period. Within 30 to 60 sec, a new epitope in the mid-molecule is detected. Additional approaches (including thrombospondin dissociation from BiP-an indirect measure of conformational maturation; t1/2 approximately 20 min) independently suggest that significant folding of monomers occurs within the trimer, i.e., well after oligomerization. These later events appear rate limiting for thrombospondin export from the ER (t1/2 approximately 30 min). The results highlight plasticity in the relationship between oligomerization and specific folding events for different proteins exported from the thyroid ER.

Ameroid rings for gradual chronic constriction of the sciatic nerve in rats: contribution of different nerves to neuropathic pain.

Mononeuropathy was induced by placing an ameroid ring around the sciatic nerve and was compared with chronic constriction injury (CCI) of the sciatic nerve [Pain 33 (1988) 87] in rats. Mechanical allodynia was assessed and the role of sciatic and saphenous afferents (Adelta and C) in thermal hyperalgesia investigated. A shorter duration of mechanical allodynia in ameroid rats as compared to CCI rats was observed. Thermal hyperalgesia was observed in the saphenous innervated skin of the hindpaw for Adelta and C nociceptors in ameroid and for Adelta nociceptors only in CCI rats, respectively. The sciatic innervated skin showed a thermal hypoalgesia with a fast onset for Adelta afferents and a slower onset for C afferents in CCI and ameroid rats. The duration of both thermal hypo- and hyperalgesia was longer in ameroid rats. We conclude that ameroid rings are a useful tool for the investigation of long-duration hyperalgesic effects of nerve injury, as the effects were more stable and seen for a longer time (>8 weeks) as compared to the CCI model. The uninjured saphenous afferents, in particular C fibers, mediate thermal hyperalgesia after chronic constriction of the sciatic nerve using an ameroid ring.

Bisegmental cervical interbody fusion using hydroxyapatite implants: surgical results and long-term observation in 70 cases.

UNLABELLED: Hydroxyapatite (HA) is the main constituent of bone mineral, and synthetic HA serves as a biocompatible and bioactive material. It permits bone growth on its surface and forms a union with the adjacent bone. OBJECT: The authors have developed implants made of porous HA, which they have used in more than 90 cases in the past 6 years to achieve cervical interbody fusion. The implants were designed to provide maximum durability, biomechanical stability, and alignment preservation and to be technically easy to use. The authors summarize their experience and results with the use of these implants. METHODS: The results of postoperative follow-up observation of 12 months or longer (mean 37.1 +/- 2.4 months) are available in 70 patients with underlying disease including: spondylosis, disc extrusion, ossification of the posterior longitudinal ligament (PLL), hypertrophy of the PLL, and trauma. The patients' ages at the time of surgery ranged from 22 to 83 years (mean 50.6 +/- 1.3 years). Flexion-extension radiographs and tomograms, obtained 6 and 12 months after surgery and every year thereafter, were used to demonstrate solid fusion in all cases. Dislocation of the implant occurred in three patients who were treated during the early portion of the series. At 6 to 12 months after surgery, encasement of the implant and formation of union were observed. Normal lordosis, if present prior to surgery, was maintained postsurgery. No neurological deterioration related to the site of fusion occurred during the period of observation. CONCLUSIONS: The authors conclude that satisfactory interbody fusion can be achieved by using HA implants, provided their design is appropriate and adequate surgical techniques are used.

Multiple idiopathic resorption in the primary dentition: review of the literature and case report.

Resorption of primary teeth is a normal physiologic process, except when it occurs prematurely. Resorption of permanent teeth is considered abnormal, and multiple etiologic factors have been implicated. A significant number of cases are represented by idiopathic resorption. Multiple idiopathic root resorption stands as a separate physiologic entity that has been described as affecting the entire permanent dentition. Multiple idiopathic resorption of primary teeth has not been previously reported. A case is described and a differential diagnosis is provided. The specific radiographic diagnostic criteria for this condition affecting the primary dentition are outlined.

A pilot study of 2 methods for control of dental unit biofilms.

OBJECTIVE: This pilot study was conducted to clinically evaluate 2 different concentrations of sodium hypochlorite for the control of dental unit biofilms and to evaluate the efficacy of pasteurizing dental treatment water for patient care. METHOD AND MATERIALS: Two dental units with no prior chemical treatment were retrofitted with self-contained water systems for this study. One dental unit was treated with 5,000 ppm of sodium hypochlorite and the other with 1,500 ppm. Treatment consisted of a 10-minute contact with the dental unit water lines, followed by a flush with a buffer solution. A pasteurizer was equipped with autoclavable spigots to provide dental treatment water. Heterotrophic Plate Count Samplers (Millipore) water sampler kits were used to quantify microbial contamination as absolute colony-forming units per millimeter. Scanning electron micrographs were taken of water line lumens to compare pretreatment and posttreatment biofilms. RESULTS: Pasteurized water was significantly less contaminated than was tap water. No significant difference in contamination was found between the 5,000 ppm and 1,500 ppm treatment chairs, either in the reservoir water or effluent water. Scanning electron micrographs demonstrated removal of the biofilms after sodium hypochlorite treatments, regardless of the concentration used. CONCLUSION: There was no significant difference between the abilities of 5,000- and 1,500-ppm concentrations of sodium hypochlorite to control contamination of dental treatment water and biofilms. Pasteurization of tap water can reduce contamination; this water can be used as acceptable dental treatment water (< 200 CFU/mL).

MDMA (ecstasy) effects on actual driving performance before and after sleep deprivation, as function of dose and concentration in blood and oral fluid.

RATIONALE: Experimental research has shown that 3,4-methylenedioxymethamphetamine (MDMA) can improve some psychomotor driving skills when administered during the day. In real life, however, MDMA is taken during the night, and driving may likely occur early in the morning after a night of "raving" and sleep loss. OBJECTIVES: The present study assessed the effects of MDMA on road-tracking and car-following performance in on-the-road driving tests in normal traffic. METHODS: Sixteen recreational MDMA users participated in a randomized double-blind placebo-controlled four-way cross-over design. They received single, evening doses of 0, 25, 50, and 100 mg MDMA on separate occasions. Actual driving tests were conducted in the evening when MDMA serum concentrations were maximal and in the morning after a night of sleep loss. RESULTS: The primary measure of driving, i.e., standard deviation of lateral position (SDLP, a measure of weaving) was significantly increased during driving tests in the morning in all treatment conditions, irrespective of MDMA dose and concentration. The increments in SDLP were of high clinical relevance and comparable to those observed for alcohol at blood alcohol concentrations >0.8 mg/mL. These impairments were primarily caused by sleep loss. CONCLUSIONS: In general, MDMA did not affect driving performance nor did it change the impairing effects of sleep loss. It is concluded that MDMA cannot compensate for the impairing effects of sleep loss and that drivers who are under the influence of MDMA and sleep deprived are unfit to drive.

A randomised clinical trial comparing minimally invasive surgery to conventional approach for endoprosthesis in elderly patients with hip fractures.

BACKGROUND: In recent years, the concept of minimally invasive surgery has invaded the orthopaedic field and literature on the subject is spawning. Mini-incision surgery for total hip arthroplasty has been studied without a clear consensus on the efficacy, safety and advantage of that technique. To our knowledge, the efficacy and safety of mini-incisions in hip fracture surgery has not been studied in a randomised fashion. METHODS: This study is a prospective clinically randomised trial whose primary objective was to demonstrate the safety and efficacy of a single posterior mini-incision approach compared to a standard posterior approach for endoprosthesis in acute femoral neck fractures. The mini-incision was defined as less than 8 cm. 25 patients in the mini-incision surgery (MIS) group and 31 patients in the standard incision group (STD) were available for analysis. The following validated disease-specific outcome instruments were used: the Lower Extremity Measurement (LEM) and the Time Up and Go (TUG). Secondary endpoints of pain, function, and quality of life were assessed by the components of the Harris Hip Score (HHS) and SF-36. Radiographic outcomes were also evaluated as well as the rates of all reported complications and adverse events during the 2 years follow-up. RESULTS: There was no significant difference for operative time, blood losses, 72 h postoperative haemoglobin as well as the need for transfusion therapy between the two groups. Also, there was no difference between the groups for postoperative morphine use and pain evaluation with the Visual Analog Scale. The functional assessment using LEM and TUG did not demonstrate any statistically significant difference between mini- and standard incision. However, the HHS and the physical function component of the SF-36 were statistically better at 2 years in favour of the standard incision group. CONCLUSION: Based on the results of the present study, we cannot recommend the use of a minimally invasive approach over a standard approach in the implantation of a cemented endoprosthesis.

Knowledge and attitudes towards cardiopulmonary resuscitation and defibrillation amongst Asian primary health care physicians.

OBJECTIVE: To assess the knowledge and attitudes of local primary health care physicians in relation to cardiopulmonary resuscitation (CPR) and defibrillation. METHODS: We conducted a survey on general practitioners in Singapore by using a self-administered questionnaire that comprised 29 questions. RESULTS: The response rate was 80%, with 60 of 75 physicians completing the questionnaire. The average age of the respondents was 52 years. Sixty percent of them reported that they knew how to operate an automated external defibrillator (AED), and 38% had attended AED training. Only 36% were willing to perform mouth-to-mouth ventilation during CPR, and 53% preferred chest compression-only resuscitation (CCR) to standard CPR. We found those aged <50 years were more likely to be trained in basic cardiac life support (BCLS) (P < 0.001) and advanced cardiac life support (P = 0.005) or to have ever attended to a patient with cardiac arrest (P = 0.007). Female physicians tended to agree that all clinics should have AEDs (P = 0.005) and support legislation to make AEDs compulsory in clinics (P < 0.001). We also found that a large proportion of physicians who were trained in BCLS (P = 0.006) were willing to perform mouth-to-mouth ventilation. CONCLUSION: Most local primary care physicians realize the importance of defibrillation, and the majority prefer CCR to standard CPR.

Observation of graphene bubbles and effective mass transport under graphene films.

Mechanically exfoliated graphene mounted on a SiO2/Si substrate was subjected to HF/H(2)O etching or irradiation by energetic protons. In both cases gas was released from the SiO2 and accumulated at the graphene/SiO2 interface resulting in the formation of "bubbles" in the graphene sheet. Formation of these "bubbles" demonstrates the robust nature of single layer graphene membranes, which are capable of containing mesoscopic volumes of gas. In addition, effective mass transport at the graphene/SiO2 interface has been observed.

Manipulation of peptide conformations by fine-tuning of the environment and/or the primary sequence.

The widely observed phenomenon that peptides are capable of adopting multiple conformations in different environments suggests that secondary structure formation in a peptide segment is a process involving not only the peptide itself but also the surrounding solvent media. The influence of the primary sequence and the molecular environment on peptide conformations are now investigated using synthetic peptides of amino acid sequence H2N-(Ser-Lys)2-Ala-X-Gly-Ala-X-Gly-Trp-Ala-X-Gly-(Lys-Ser)3-OH, where X = Ile or Val. These two peptides, namely 3I (X = Ile) and 3V (X = Val), are found to lack defined secondary structure in aqueous buffer. However, discrete conformational states, e.g., alpha-helices and beta-sheets, are readily generated and interconverted for both peptides when the buffer is modulated with the addition of methanol, sodium dodecyl sulfate (SDS) micelles, or phospholipid vesicles. The role of the primary sequence in affecting peptide conformations is manifested in that peptides 3I and 3V, which differ respectively in their content of beta-branched Ile or Val residues, differ in their secondary structures at monomeric concentrations in 2 mM SDS and in mixed lipid vesicles of phosphatidic acid and phosphatidylcholine. The overall results suggest that peptide segments can be conformationally flexible entities poised to react to minor modulation in either the molecular environment or the primary sequence, a circumstance that may be relevant to protein functioning and folding.

Crosslinking characteristics of an injectable poly(propylene fumarate)/beta-tricalcium phosphate paste and mechanical properties of the crosslinked composite for use as a biodegradable bone cement.

We investigated the crosslinking characteristics of an injectable composite paste of poly(propylene fumarate) (PPF), N-vinyl pyrrolidinone (N-VP), benzoyl peroxide (BP), sodium chloride (NaCl), and beta-tricalcium phosphate (beta-TCP). We examined the effects of PPF molecular weight, N-VP/PPF ratio, BP/PPF ratio, and NaCl weight percent on the crosslinking temperature, heat release upon crosslinking, gel point, and the composite compressive strength and modulus. The maximum crosslinking temperature did not vary widely among formulations, with the absolute values falling between 38 degrees and 48 degrees C, which was much lower than that of 94 degrees C for poly(methyl methacrylate) bone cement controls tested under the same conditions. The total heat released upon crosslinking was decreased by an increase in PPF molecular weight and a decrease in N-VP/PPF ratio. The gel point was affected strongly by the PPF molecular weight, with a decrease in PPF molecular weight more rapidly leading to a gel point. An increase in initiator concentration had the same effect to a lesser degree. The time frame for curing was varied from 1-121 min, allowing the composite to be tailored to specific applications. The compressive strength and compressive modulus values increased with decreasing N-VP/PPF, increasing NaCl content, and increasing BP/PPF ratio. For all formulations, the compressive strength values fell between 1 and 12 MPa, and the compressive modulus values fell between 23 and 265 MPa. These data suggest that injectable PPF/beta-TCP pastes can be prepared with handling characteristics appropriate for clinical orthopedic applications and that the mechanical properties of the cured composites are suitable for trabecular bone replacement.

Preparation and physical characterization of alginate microparticles using air atomization method.

Alginate microparticles were prepared using an air atomization method and varying formulation and processing conditions. Thereafter, the size and surface morphology of alginate microparticles were characterized. The trapping efficiencies of the ketoconazole, acetaminophen, vitamin C, and Bifidobacteria bifidum as model core materials were then determined. The air atomization process produced free-flowing and small-size microparticles after the freeze-drying process. The size distribution and surface morphology varied depending on the concentration of wall-forming materials and processing conditions. Generally, the geometric mean size increased as the concentration of alginate and poly-1-lysine and the delivery rate increased, but the air pressure decreased. Most of all, the ratio of delivery rate of alginate solution and air pressure could affect the size and surface morphology of alginate microparticles. However, the geometric mean size of alginate poly-1-lysine microparticles reproducibly ranged from about 80 to 130 microm. The microparticles were irregularly spherical or elliptical. The trapping efficiencies of ketoconazole, acetaminophen, vitamin C, and bifidobacteria were determined to be 71.5%, 60.1%, 1.6%, and 31%, respectively, when alginate concentration (1.5%), poly-1-lysine concentration (0.02%), air pressure (0.75 bar), delivery rate (8 ml/min), and spraying distance (45 cm) were applied. The current microencapsulation process using the air atomization method provides an alternative to entrapping small molecules and macromolecules without using harmful organic solvents. In addition, the small-size and free-flowing alginate microparticles containing active substances can be used as an intermediate in pharmaceutical applications.