Assessment of oral hypofunction and its association with age among Korean community-dwelling older adults.

BACKGROUND: Due to the increasing proportion of older adults in Korea and growing interest in aging, the concepts of oral aging and oral hypofunction have recently been introduced. Thus, it is necessary to investigate the age-specific oral function levels of Korean older adults and develop expert intervention methods for healthy aging. METHODS: Dysphagia, independence of daily living, and oral hypofunction were assessed in 206 older adults living in Wonju, Gangwon State, South Korea. Subjective dysphagia was assessed through self-report questionnaires using the Dysphagia Handicap Index (DHI), the Korean version of Eating Assessment Tool-10, and the Korean version of the Modified Barthel Index. In addition, the oral hypofunction assessment items included decreased chewing ability, occlusal pressure, tongue pressure, oral dryness, and oral cleanliness. RESULTS: DHI increased significantly with age, with those in their 80 s reporting the most difficulty swallowing. Oral function in terms of chewing ability (maximum occlusal pressure and number of remaining teeth), maximum occlusal pressure, and maximum tongue pressure also declined with increasing age. While there was no significant difference in oral dryness by age, those in their 80 s had dry mouth according to the criteria of the oral moisture checking device. CONCLUSIONS: In an assessment of oral function in community-dwelling, independent Korean older adults, the number of items that were assessed as oral hypofunction increased with age. The findings can be used to standardize the oral hypofunction assessment item and develop age-based individualized intervention plans for the early management of oral health and individual oral myofunctional rehabilitation in Korean community-dwelling older adults.

Assessment of patient-reported outcomes (PROs): treatment satisfaction, medication adherence, and quality of life (QoL) and the associated factors in postmenopausal osteoporosis (PMO) patients in Korea.

Patient-reported outcomes (PROs) provide practical guides for treatment; however, studies that have evaluated PROs of women in Korea with postmenopausal osteoporosis (PMO) are lacking. This cross-sectional, multi-center (29 nationwide hospitals) study, performed from March 2013 to July 2014, aimed to assess PROs related to treatment satisfaction, medication adherence, and quality of life (QoL) in Korean PMO women using osteoporosis medication for prevention/treatment. Patient demographics, clinical characteristics, treatment patterns, PROs, and experience using medication were collected. The 14-item Treatment Satisfaction Questionnaire for Medication (TSQM) (score-range, 0-100; domains: effectiveness, side effects, convenience, global satisfaction), Osteoporosis-Specific Morisky Medication Adherence Scale (OS-MMAS) (score-range, 0-8), and EuroQol-5 dimensions questionnaire (index score range, - 0.22 to 1.0; EuroQol visual analog scale score range, 0-100) were used. To investigate factors associated with PROs, linear (treatment satisfaction/QoL) or logistic (medication adherence) regression analyses were conducted. A total of 1804 patients (age, 62 years) were investigated; 60.1% used bisphosphonate, with the majority (67.2%) using weekly medication, 27.8% used daily hormone replacement therapy, and 12.1% used daily selective estrogen receptor modulator. Several patients reported gastrointestinal (GI) events (31.6%) and dental visits due to problems (24.1%) while using medication. Factors associated with the highest OS-MMAS domain scores were convenience and global satisfaction. GI events were associated with non-adherence. TSQM scores for effectiveness, side effects, and GI risk factors were significantly associated with QoL. Our study elaborately assessed the factors associated with PROs of Korean PMO women. Based on our findings, appropriate treatment-related adjustments such as frequency/choice of medications and GI risk management may improve PROs.

Evaluation of the ceramic liner bonding effect between zirconia and lithium disilicate.

STATEMENT OF PROBLEM: Little information is available for the strength of bonding between zirconia and lithium disilicate as affected by surface pretreatment methods. PURPOSE: The purpose of this in vitro study was to investigate the shear bond strength (SBS) between zirconia core and lithium disilicate (LS2) veneered ceramic after surface pretreatments. MATERIAL AND METHODS: Fully sintered yttrium oxide partially stabilized tetragonal zirconia (Y-TZP) disk specimens were fabricated from zirconia ceramic materials. Specimens were divided into 4 groups with surface pretreatments applied (the as-received group, the liner group, the airborne-particle abrasion group, and the airborne-particle abrasion-plus-liner group). After pressing LS2 on a zirconia disk, shear force was applied perpendicular to the zirconia-LS2 interface. Data were analyzed using 2-way ANOVA and Tukey test (α=.05). For each group, the failure modes were measured by using optical microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and x-ray diffraction. RESULTS: Airborne-particle abrasion induced significantly lower interfacial strength between zirconia and lithium disilicate (P<.05). After airborne-particle abrasion of the surface, the increased monoclinic volume fraction and reduced coefficient of thermal expansion of zirconia may weaken the interfacial strength between zirconia and LS2. The liner treatment significantly improved the adhesion between zirconia core and veneering LS2 (P<.05). The SBS values decreased in the following order: liner group > airborne-particle abrasion-plus-liner group > airborne-particle abrasion group. The interfacial image of zirconia and LS2 showed a fusion of crystal structure between the 2 materials. Some components of the silica-containing glass-ceramic liner led to an increase in SBS as diffusion occurred on the zirconia surface. CONCLUSIONS: The bond strength between zirconia and veneering LS2 was significantly increased by application of silica-containing glass-ceramic liner but was decreased with airborne-particle abrasion.

Continuous noninvasive hemoglobin measurement is useful in patients undergoing double-jaw surgery.

PURPOSE: Continuous measurement of hemoglobin by pulse CO-oximetry (SpHb; Masimo Radical 7 device, Masimo Corp, Irvine, CA) may be helpful during double-jaw surgery when massive hemorrhage is anticipated. Given the possible influence of low blood pressure on the detection of hemoglobin levels, the agreement of the SpHb was evaluated in patients undergoing orthognathic surgery when using hypotensive anesthesia. MATERIALS AND METHODS: Patients who underwent elective Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSO) were enrolled in this observational prospective cohort study. SpHb was compared with time-matched arterial total hemoglobin (tHb) before incision, at Le Fort I osteotomy, at BSSO, and at skin closure. The correlation between simultaneous SpHb and tHb measurement pairs was evaluated. Agreement was assessed by a comparison of SpHb with tHb using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. RESULTS: The average age of 51 patients was 23 ± 5 years and 32 patients were male. The correlations of SpHb and tHb measurements were 0.72, 0.85, 0.89, and 0.78 before incision, at Le Fort I osteotomy, at BSSO, and at closure, respectively. Bland-Altman analysis for SpHb and tHb showed respective bias values of 0.12, 0.07, -0.09, and -0.90 g/dL. ICC values between SpHb and tHb were 0.82, 0.90, 0.91, and 0.87, respectively. CONCLUSIONS: Continuous monitoring of hemoglobin may help to determine the appropriate time to perform an invasive measurement of hemoglobin in patients who undergo double-jaw surgery.

Single oral dose pharmacokinetics of decursin, decursinol angelate, and decursinol in rats.

Decursin and decursinol angelate are the major components in the alcoholic extract of the root of Angelica gigas Nakai. Our previous work convincingly demonstrated that both decursin and decursinol angelate were rapidly converted to decursinol in mice after administration by either oral gavage or i. p. injection. In the current study, we compared for the first time the plasma profiles of decursinol, when equal moles of decursin/decursinol angelate or decursinol were given to rats by oral gavage, and investigated the effect of different formulas and other chemicals in Angelica gigas extract on the bioavailability of decursinol. Our results show that gavage of decursinol led to a faster attainment of plasma decursinol peak (Tmax ~ 0.7 h) and much higher peak levels than an equal molar amount administered as decursin/decursinol angelate mixture or as Angelica gigas ethanol extract, resulting in 2-3 fold higher bioavailability as estimated by the area under the curve of the respective regimens (65 012 vs. 27 033 h · ng/mL for decursinol and decursin/decursinol angelate treatment groups, respectively). Compared to a formula based on ethanol-PEG400-Tween80, carboxyl methyl cellulose was a less optimized vehicle. In addition, we detected peak levels of decursin and decursinol angelate in the plasma of rats administered with decursin/decursinol angelate or Angelica gigas extract in the nM range (Tmax ~ 0.5 h) with a newly established sensitive UHPLC-MS/MS method. Furthermore, our data support the liver, instead of intestine, as a major organ site where decursin and decursinol angelate were hydrolyzed to decursinol with a S9 microsomal in vitro metabolism assay. Taken together, our study provided important PK, LC-MS/MS methodology, formulation and metabolism insights in a rodent model for the rational design of in vivo efficacy studies of the corresponding chemicals in the future.

Two new temporary ectoparasitic isopods (Cymothoida: Cymothooidea) from Korean waters with a note on geographical distributions of Rocinela Leach, 1818 and Gnathia Leach, 1814.

Two new species of temporary ectoparasitic isopods, Rocinela excavata sp. nov. and Gnathia obtusispina sp. nov., are reported from the southern Islands of the Korean Peninsula. Rocinela excavata sp. nov. is distinguishable from its related species by the following characteristics: (1) laterally stepped rostrum; (2) separated eyes; (3) propodal blade having eight robust setae; and (4) merus having four or five blunt robust setae in pereopods 1-3. Gnathia obtusispina sp. nov. differs from its congeners by the combination of the following characteristics: (1) body covered with numerous tubercles and setae, (2) cephalon having tooth-like paraocular ornamentations; and (3) frontal border having two inferior frontolateral processes. These two new species are the 13th Rocinela species and 19th Gnathia species in the temperate Northern Pacific region, respectively. Discovery of these new species represents high species diversity of the genera Rocinela Leach, 1818 and Gnathia Leach, 1814 worldwide as well as in the Northern Pacific region. In addition, faunal diversity analysis on the members of both genera revealed that Rocinela species show high-latitude diversity whereas Gnathia species have low-latitude diversity.

Proteomic analysis of mesenchymal stem-like cells derived from ovarian teratoma: potential role of glutathione S-transferase M2 in ovarian teratoma.

Ovarian teratoma is a dermoid cyst in the ovary that contains mature tissues such as hair, teeth, bone, thyroid, etc. To understand the molecular mechanisms of ovarian teratoma growth, a comparative proteomic analysis was undertaken using mesenchymal stem cell-like cells (MSCLCs) isolated from normal human ovarian or teratoma tissues. Both normal ovarian and teratoma MSCLCs expressed stem cell markers OCT4 and NANOG, and were negatively staining with the senescence-associated (SA) ß-galactosidase. Furthermore, teratoma MSCLCs had higher proliferation and colony formation rates, with more angiogenic property than that of normal MSCLCs. Proteomic study revealed that 17 proteins had the expression changes over eightfold in ovarian teratoma MSCLCs compared with normal control. Interestingly, among them, GSTM2 was strongly expressed in teratoma MSCLCs. Moreover, overexpressed GSTM2 in the teratoma was associated with downregulation of p38 MAPK and activation of AKT and survivin. Taken together, these findings suggest that that ovarian teratoma MSCLCs have a higher potency for proliferation and angiogenesis and GSTM2 appears to be involved in the regulation of other survival genes.

Oral health status of inpatients with varying physical activity limitations in rehabilitation wards: A cross-sectional study.

ABSTRACT: Poor oral hygiene can be potentially life-threatening in inpatients. However, no basic protocol on oral hygiene customized for inpatients exists, and lack of oral care related knowledge, attitude, and skills among caregivers could be detrimental to the general health of patients. This study sought to identify the oral care practices and oral health status of inpatients with varying physical activity limitations in a rehabilitation ward.Sixty-one inpatients in a rehabilitation ward were evaluated for their medical and physical conditions and oral health status. These were assessed using the bedside oral exam, decayed, missing, filled teeth index, plaque index, gingival index, and caries activity test.In total, 40 men and 21 women (mean age, 56.6 years) were included in this study. Among them, 50.8% of the patients could brush their teeth unassisted, whereas 49.2% required assistance from an assistant for oral care. The proportion of patients receiving nasogastric tube feeding was higher in the group that could not provide oral self-care; 36.7% and 33.3% of these patients showed moderate and severe dysfunction, respectively, based on bedside oral exam. Scores for the swallowing, tongue, and total domains of bedside oral exam were poorer for patients who could not provide oral self-care (P < .01). The caries activity test indicated a moderate risk for both groups.Our findings suggest that an oral care protocol that considers the physical activity limitations in inpatients in rehabilitation wards is necessary to minimize negative influences on the systemic health of these patients.

Developmental features and predicting airway failure risk in critically ill children with mandibular hypoplasia using 3D computational tomographic analysis.

In children with mandibular hypoplasia, airway management is challenging. However, detailed cephalometric assessment data for this population are sparse. The aim of this study was to find risk factors for predicting difficult airways in children with mandibular hypoplasia, and compare upper airway anatomical differences using three-dimensional computed tomography (3D CT) between children with mandibular hypoplasia and demographically matched healthy controls. There were significant discrepancies in relative tongue position (P < 0.01) and anterior distance of the hyoid bone (P < 0.01) between patients with mandibular hypoplasia and healthy controls. All mandibular measures were significantly different between the two groups, except for the height of the ramus of the mandible. After adjusting for age and sex, the anterior distance of hyoid bone and inferior pogonial angle were significantly associated with a difficult airway (P = 0.01 and P = 0.02). Quantitative analysis of upper airway structures revealed significant discrepancies, including relative tongue position, hyoid distance, and mandible measures between patients with mandibular hypoplasia and healthy controls. The anterior distance of the hyoid bone and inferior pogonial angle may be risk factors for a difficult airway in patients with mandibular hypoplasia.

Protein kinase C ßII and δ/θ play critical roles in bone morphogenic protein-4-stimulated osteoblastic differentiation of MC3T3-E1 cells.

Bone morphogenic protein-4 (BMP-4), one of TGF-ß superfamily, is involved in bone and cartilage development, specifically tooth and bone fracture repair. In the present study, the role of protein kinase C (PKC) was investigated in BMP-4-induced differentiation of osteoblast-like MC3T3-E1 cells. PKC inhibitor UCN-01 significantly attenuated the synthesis of osteocalcin, a marker of mature osteoblast phenotype, in a dose-dependent manner as well as blocked osteroblastic differentiation and mineralization in BMP-4-treated MC3T3-E1 cells. Also, UCN-01 suppressed vascular endothelial growth factor (VEGF) production in BMP-4-treated MC3T3-E1 cells. In addition, UCN-01 remarkably suppressed BMP-4-activated PKC ßII and PKC δ/θ of PKC family proteins by Western blotting. Consistently, 2-dimensional electrophoresis (2-DE) immunoblotting revealed that UCN-01 inhibited the BMP-4-induced activation of PKC subfamilies in MC3T3-E1 cells. Taken together, our findings suggest that PKC ßII and PKC δ/θ mediate BMP-4-induced osteoblastic differentiation.

Patient-specific and hyper-realistic phantom for an intubation simulator with a replaceable difficult airway of a toddler using 3D printing.

Difficult tracheal intubation is the third most common respiratory-related adverse co-morbid episode and can lead to death or brain damage. Since difficult tracheal intubation is less frequent, trainees have fewer opportunities to perform difficult tracheal intubation; this leads to the need to practice with a hyper-realistic intubation simulator. However, conventional simulators are expensive, relatively stiffer than the human airway, and have a lack of diversity in terms of disease variations and anatomic reproducibility. Therefore, we proposed the development of a patient-specific and hyper-realistic difficult tracheal intubation simulator using three-dimensional printing technology and silicone moulding and to test the feasibility of patient-specific and hyper-realistic difficult intubation simulation using 3D phantom for the trainee. This difficult tracheal intubation phantom can provide a realistic simulation experience of managing various difficult tracheal intubation cases to trainees, which could minimise unexpected tissue damage before anaesthesia. To achieve a more realistic simulation, a patient-specific phantom was fabricated to mimic human tissue with realistic mouth opening and accurate difficult airway shape. This has great potential for the medical education and training field.

Associations between dietary habits, emotional state and subjective oral symptoms in 62,276 South Korean adolescents.

OBJECTIVE: The purpose of this study was to investigate the associations between dietary habits, emotional states, and subjective oral symptoms in Korean adolescents. METHODS: Data from 62,276 adolescents were derived from the 13th Korean Youth Risk Behavior Web-based Survey, conducting from June 1, 2017 to June 30, 2017. Oral symptoms were assessed by asking students whether they had experienced any of following symptoms within the last 12 months: (i) have you had a crack in your teeth or had any broken teeth not caused by exercise or other accidents?, (ii) have you experienced any toothaches while drinking or eating cold or hot beverages or foods?, (iii) have you ever felt throbbing in your teeth?, and (iv) have you experienced any gum pain or gum bleeding? A multivariable Poisson regression model for prevalence ratio (PR) was conducted. RESULTS: Of the participants, 53.1% experienced subjective oral symptoms. After adjusting for confounders, participants with consumption of sweet drinks more than five times weekly in dietary behaviors (PR: 1.17 [95% confidence interval (CI); 1.13-1.21]), feeling stress in the emotional state (PR: 1.27 [95% CI; 1.24-1.31]), and never brushing teeth (PR: 1.22 [95% CI; 1.14-1.30]) in the frequency of toothbrushing had higher risks of having oral symptoms compared to the reference group. CONCLUSION: Many adolescents in Korea experienced oral symptoms. The consumption of sweet drinks, infrequent toothbrushing, and a negative emotional state adversely affected perceived oral symptoms. Public concern about the oral health of adolescents is warranted.

Surface plasmon resonance investigation of a copolymer containing spiroxazine.

Spiroxazines are a class of photochromic compounds whose molecular structures are alterable upon exposure to UV/visible light. The typical reaction of spiroxazines is the conversion between the non-polar ring-closure form and polar ring-open form. In this work, copolymer of 1,6-heptadiyne derivatives containing a spiroxazine was used as photochromic material. Precise photochromic properties of the copolymer's thin-film were evaluated through measuring dielectric constant, optical constant and thickness by surface plasmon resonance (SPR) with multi-solvent approach. The change in structure under UV-light irradiation is accompanied by increase of dielectric constant. However, dielectric constant and UV-induced thickness change of the photochromic polymer thin-film are independent of film thickness.

Folate-tethered emulsion for the target delivery of retinoids to cancer cells.

Folic acid, conjugated to poly(ethylene glycol)-distearoylphosphatidylethanolamine (folate-PEG-DSPE), was used to target emulsions of all-trans retinoic acid (ATRA) to folate receptor-overexpressing tumor cells. Two kinds of ATRA-incorporated folate-tethered emulsions (ATRA-FTE 2000/3400) were prepared using soybean oil, egg phosphatidylcholine and folate-PEG-DSPE with different PEG length. As a control, ATRA-incorporated non-tethered emulsion (ATRA-NTE) was prepared by using PEG2000-DSPE without folate instead of using folate-PEG-DSPE. The mean particle diameters of ATRA-FTE 2000/3400 were about 100-130 nm. The cellular uptake in KB cells of fluorescence-labeled ATRA-FTE 3400 was determined with HPLC (for ATRA) and confocal microscopy (for lipid emulsion). The growth inhibitory activity of ATRA was evaluated by MTT assay. The folate ligands in emulsion increased the cellular uptake of ATRA about 3-fold and 1.6-fold in ATRA-FTE 3400 and ATRA-FTE 2000, respectively. Growth inhibitory activity of ATRA-FTE 3400 in KB cells was higher than that of ATRA-NTE at the same dose. Whereas the growth inhibitory effect in MCF-7 cells of ATRA was similar between ATRA-NTE and ATRA-FTE 3400. The addition of free folate significantly reduced the uptake of ATRA regardless of the length of PEG attached to folate. Folate-tethered lipid emulsion showed effective and selective delivery to the folate receptor-abundant carcinomas, suggesting a potential for targeted delivery of anticancer agents.

Hydrogen-absorbing alloy-based metal-hydride actuation for application in rehabilitative systems.

BACKGROUND: A lightweight rehabilitation assisting system is required to help the aged and disabled with daily life activities, thereby improving the quality of their lives. OBJECTIVE: This paper discusses the development of a metal-hydride (MH) actuator, with excellent heat transfer performance, for application in a rehabilitative system incorporating an MH module. METHODS: The operating mechanism of MH actuators requires that the mechanical power of the pneumatic actuator only be generated via heat transfer through a Peltier element and the absorption/desorption of a hydrogen-contained MH module. To achieve this aim, a 3D model was first designed for two MH modules, and a thermal analysis was carried out according to the type of contact with the Peltier elements to fabricate an MH module with improved heat transfer performance. LabVIEW (National Instruments) was used for automatic temperature control of the Peltier element in the MH actuator driving experiment. Zr0.9TI0.1Cr0.6Fe1.4, which yields a pressure-composition-temperature (PCT) curve of appropriate pressure and temperature ranges for a rehabilitative system, was selected as the hydrogen-absorbing alloy. RESULTS: In addition, the temperature conditions of the MH actuator driving experiment were restricted by two temperature control ranges (30-40∘C/30-50∘C) of the Peltier element. Within these Peltier element temperature ranges of 30-40∘C and 30-50∘C, results showed that the MH actuator was driven in the ranges of 2-3 atm and 2.5-3.5 atm, respectively. CONCLUSIONS: These findings indicate that the MH actuator proposed in this paper can be utilized to drive a rehabilitative system for elbow and knee joint exoskeletons.

Nerve regeneration with the use of a poly(l-lactide-co-glycolic acid)-coated collagen tube filled with collagen gel.

AIM: The aim of this study was to develop a novel artificial nerve conduit and to evaluate its efficiency based on the promotion of peripheral nerve regeneration in rabbits. MATERIAL AND METHODS: The nerve conduit was made of a poly (l-lactide-co-glycolic acid)-coated collagen tube filled with collagen gel. The conduits were implanted into a 15 mm gap in the peroneal nerves of five rabbits. On the contralateral side, the defects were bridged with collagen-filled vein grafts. RESULTS: Twelve weeks postoperatively nerve regeneration was superior to the vein graft in the PLGA-coated collagen tube, both morphologically and electrophysiologically. CONCLUSION: The results indicate the superiority of the PLGA-coated collagen tube over vein grafts. Furthermore, they show that entubulation repair with this type of tube can support nerve regeneration over a nerve gap distance of at least 15 mm.

Comparative analysis for evaluating the traceability of interventional devices using blood vessel phantom models made of PVA-H or silicone.

OBJECTIVE: In this paper, we investigated the parameters with effective traceability to assess the mechanical properties of interventional devices. METHODS: In our evaluation system, a box-shaped poly (vinyl alcohol) hydrogel (PVA-H) and silicone were prepared with realistic geometry, and the measurement and evaluation of traceability were carried out on devices using load hand force. The phantom models had a total of five curve pathways to reach the aneurysm sac. RESULTS: Traceability depends on the performance of the interventional devices in order to pass through the curved part of the model simulation track. The traceability of the guide wire was found to be much better than that of the balloon and stent loading catheter, as it reached the aneurysm sac in both phantom models. CONCLUSIONS: Observation using the video record is another advantage of our system, because the high transparency of the materials with silicone and PVA-H can allow visualization of the inside of an artery.

Endotracheal intubation by inexperienced trainees using the Clarus Video System: learning curve and orodental trauma perspectives.

BACKGROUND: The ideal alternative airway device should be intuitive to use, yielding proficiency after only a few trials. The Clarus Video System (CVS) is a novel optical stylet with a semi-rigid tip; however, the learning curve and associated orodental trauma are poorly understood. METHODS: Two novice practitioners with no CVS experience performed 30 intubations each. Each trial was divided into learning (first 10 intubations) and standard phases (remaining 20 intubations). Total time to achieve successful intubation, number of intubation attempts, ease of use, and orodental trauma were recorded. RESULTS: Intubation was successful in all patients. In 51 patients (85%), intubation was accomplished in the first attempt. Nine patients required two or three intubation attempts; six were with the first 10 patients. Learning and standard phases differed significantly in terms of success at first attempt, number of attempts, and intubation time (70% vs. 93%, 1.4 ± 0.7 vs. 1.1 ± 0.3, and 71.4 ± 92.3 s vs. 24.6 ± 21.9 s, respectively). The first five patients required longer intubation times than the subsequent five patients (106.8 ± 120.3 s vs. 36.0 ± 26.8 s); however, the number of attempts was similar. Sequential subgroups of five patients in the standard phase did not differ in the number of attempts or intubation time. Dental trauma, lip laceration, or mucosal bleeding were absent. CONCLUSIONS: Ten intubations are sufficient to learn CVS utilization properly without causing any orodental trauma. A relatively small number of experiences are required in the learning curve compared with other devices.

Investigation of the factors influencing the release rates of cyclosporin A-loaded micro- and nanoparticles prepared by high-pressure homogenizer.

An oil-in-water solvent evaporation method was used to prepare cyclosporin A (CyA)-loaded particles varying in size (nanoparticles, 'small-sized' microparticles, 'large-sized' microparticles), polymer compositions [poly(D,L-lactide-co-glycolic acid) (PLGA) 50/50, PLGA 85/15, poly(D,L-lactic acid) (PLA)] and additive fatty acid ester (ethyl myristate; EM). The particles were characterized for drug loading and entrapment efficiency by high-performance liquid chromatography, particle size by dynamic light scattering and surface morphology by scanning electron microscopy (SEM). In vitro release kinetics were studied using a modified dialysis method. The results showed drug loadings ranging from 6.48 to 9.01% with high encapsulation efficiency (71.2-98.9%). SEM studies showed discrete and spherical particles with smooth surfaces, whereas rather gross surface defects resulted from the incorporation of EM as an additive. The release profiles of various formulations approximated zero-order release kinetics in the first 3 weeks with a negligible initial burst. In general, the smaller the particle size and the higher the glycolic acid content in the copolymer, the faster the release of CyA. The effect of EM on the release profile appeared to be rather complex since an increased release rate was observed from EM containing PLGA 50/50 particles, whereas the incorporation of EM into the PLGA 85/15 and PLA particles led to a decreased release rate. Further investigation needs to be performed to elucidate the reason why EM influences the CyA release differently depending on the particle size and polymer type.

Effect of Powerdental on caries-inducing properties of Streptococcus mutans and TNF-alpha secretion from HMC-1 cells.

We studied the inhibitory effect of Powerdental on the growth and acid production of Streptococcus mutans as well as secretion of pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha). The growth of Streptococcus mutans was reduced by the presence of the Powerdental (1 mg/ml) and NaCl (1 mg/ml) significantly, and the positive control group (1% NaF) also exhibited a significant antibacterial activity. The decrease of pH was significantly inhibited in the presence of Powerdental (1 mg/ml) compared to the control group. The decrease in pH was also inhibited in the presence of positive control (1% NaF), but the bamboo salt alone did not show inhibitory activity. We also found that Powerdental (0.01 mg/ml) inhibited significantly the secretion of TNF-alpha with 46.5+/-0.2% from human mast cells. Our results suggest that Powerdental contributes to the prevention or treatment of periodontitis and other oral diseases or inflammatory diseases.