Retrospective study of the absorbable braided polydioxanone threads' usefulness in the aged lower eyelids' rejuvenation.

BACKGROUND: Tear trough deformity, hyperpigmentation, and skin laxity of the lower eyelid make individuals appear fatigued and elderly. Many patients prefer less invasive, cosmetic correction of the aged lower eyelid. Polydioxanone (PDO)-barbed threads introduced braided fine threads design, which works as a template for attraction of the regenerative factors and for cells' migration and proliferation. The purpose of this study was to estimate the outcomes of simultaneous additional application of braided type PDO threads (N-scaffold) for aged lower eyelids' rejuvenation in patients, who underwent the midface PDO thread lifting. MATERIALS AND METHODS: A total of 30 patients with mildly loose skin in the facial area, who underwent the thread lifting using PDO threads, were included in this study. Patients were divided into two groups, 15 patients per group. The first group underwent the midface thread lifting using PDO threads ("non-SCA" group). The second group underwent midface thread lifting in combination with braided PDO threads for tear trough deformity improvement ("N-scaffold" group). The results were evaluated subjectively, based on the patients' satisfaction rates, and objectively, by evaluating photographs. RESULTS: According to Barton's grading system, 7 months after the treatment, there was a statistically significant difference between the two groups: 1.733 ± 0.74 in the non-SCA group and 0.733 ± 0.83 in the N-scaffold group (p < 0.05). Based on patients' self-assessment, there was a significant difference at 7 months after the treatment: 2.86 ± 0.84 in "non-SCA" group and 3.76 ± 0.90 in "N-scaffold" group, p < 0.05. Complications such as persistent swelling, hematoma, skin irregularity, and infection were not observed during follow-up assessments. CONCLUSION: The application of braided type PDO threads (N-scaffold) as part of the midface thread lifting, for aged lower eyelids rejuvenation appears to be effective and safe within a period. This study suggests that PDO threads insertion may be a useful, additional, and non-invasive tool for the aged lower eyelids rejuvenation.

Experimental study on polycaprolactone scaffold cell-based nasal implant using 3D printing.

BACKGROUND: This study was conducted to address the potential of combining porous biocompatible scaffolds with primary cells or autologous diced cartilage in cartilage tissue engineering in the animal model. The purpose of this study is an experimental evaluation of polycaprolactone (PCL) scaffold cell-based nasal implant using three-dimensional (3D) printing. METHODS: In this study, we applied hollow PCL cage scaffolds with 200 and 400 µm pore sizes. The scaffolds were divided into three groups (n = 4 for each group): (1) PCL cage scaffolds loaded with agarose gel and chondrocytes; (2) PCL cage scaffolds loaded with agarose gel and fibroblasts, and (3) PCL cages loaded with autologous diced cartilage. In each group, chondrocytes and fibroblasts were seeded into the agarose gel at the density of 5 × 106 cells/mL. RESULTS: All implants showed sufficient integration into the surrounding tissue. It was revealed that chondrocytes were proliferated and differentiated better in the "400 µm" scaffolds than in the "200 µm" group. However, a pore size of 200 µm was optimal for fibroblasts' proliferation. In addition, the results of our study showed that the use of PCL-based scaffolds can achieve the desirable stable augmentation effect with almost none of the changes of contour. CONCLUSION: In this study, both groups: (1) PCL cage scaffolds loaded with agarose gel and chondrocytes and (2) PCL cages loaded with autologous diced cartilage demonstrated chondrogenic potential with scaffolds with 400 µm pore size. The PCL cage scaffolds loaded with agarose gel and fibroblasts demonstrated potential in cartilage tissue formation within the pore size of 200 µm.

Migration of substances from food contact plastic materials into foodstuff and their implications for human exposure.

The safety of food contact plastic materials, including PP, PE, PET, PCT, PLA, PBT and cross-linked polyester, was assessed with regard to migrated substances. The migrated concentrations of overall migrants (OMs), terephthalic acid, acetaldehyde, 1,4-butanediol and lead, were determined according to the standards and specifications for utensils, containers and packages in Korea. Food simulants of 4% acetic acid, water and n-heptane were used for the analysis of the substances. The dietary exposures of terephthalic acid, acetaldehyde and 1,4-butanediol were assessed using the dietary concentrations and the food consumption data. As a result, the dietary exposures were considered to be safe comparing to the health-based guidance values. In the case of lead, the margin of exposure (MOE) approach was applied. The MOEs calculated using the UB concentration and mean consumption data were ranged from 3 to 1000, which indicated low concern for health risk. Moreover, in this study, the dietary exposures were estimated by the Korean MFDS and U.S. FDA methods, respectively. As a result, the assessed risks were considered to be low in both cases. Based on the results of current exposure assessments, it could be considered that the food contact plastic materials are properly controlled by the regulatory authorities.

Radiosurgery for large cerebral arteriovenous malformations.

BACKGROUND: Radiosurgery is an effective treatment option for patients with small to medium sized arteriovenous malformations. However, it is not generally accepted as an effective tool for larger (>14 cm(3)) arteriovenous malformations because of low obliteration rates. The authors assessed the applicability and effectiveness of radiosurgery for large arteriovenous malformations. METHOD: We performed a retrospective study of 46 consecutive patients with more than 14 ml of arteriovenous malformations who were treated with radiosurgery using a linear accelerator and gamma knife (GK). They were grouped according to their initial clinical presentation-17 presented with and 29 without haemorrhage. To assess the effect of embolization, these 46 patients were also regrouped into two subgroups-25 with and 21 without preradiosurgical embolization. Arteriovenous malformations found to have been incompletely obliterated after 3-year follow-up neuroimaging studies were re-treated using a GK. FINDINGS: The mean treatment volume was 29.5 ml (range, 14.0-65.0) and the mean marginal dose was 14.1 Gy (range, 10.0-20.0). The mean clinical follow-up periods after initial radiosurgery was 78.1 months (range, 34.0-166.4). Depending on the results of the angiography, 11 of 33 patients after the first radiosurgery and three of four patients after the second radiosurgery showed complete obliteration. Twenty patients received the second radiosurgery and their mean volume was significantly smaller than their initial volume (P = 0.017). The annual haemorrhage rate after radiosurgery was 2.9% in the haemorrhage group (mean follow-up 73.3 months) and 3.1% in the nonhaemorrhage group (mean follow-up 66.5 months) (P = 0.941). Preradiosurgical embolization increased the risk of haemorrhage for the nonhaemorrhage group (HR, 28.03; 95% CI, 1.08-6,759.64; P = 0.039), whereas it had no effect on the haemorrhage group. Latency period haemorrhage occurred in eight patients in the embolization group, but in no patient in the nonembolization group (P = 0.004). CONCLUSIONS: Radiosurgery may be a safe and effective arteriovenous malformation treatment method that is worth considering as an alternative treatment option for a large arteriovenous malformation.

Background levels and dietary intake of PCDD/Fs in domestic and imported meat in South Korea.

A survey was conducted in South Korea to determine residual levels and dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) from meat. Altogether 119 domestic and 164 imported samples of beef, pork, and chicken were examined. The mean levels of PCDD/Fs in upper bound were 0.21, 0.22, and 0.04pg WHO-TEQ/g fat for beef, pork, and chicken, respectively. The low level of PCDD/Fs in chicken probably resulted from the low fat content in the samples used. The samples were separated into domestic and imported products in order to investigate the sources of contamination. PCDFs were the more dominant congeners in domestic beef and were similar to those found from emission of incineration. However, the congener profiles of domestic beef and incineration were difficult to compare because the environmental fate and animal metabolism were involved. The upper bound dietary intake of PCDD/Fs from beef, pork and chicken was calculated to be 0.04pg/WHO-TEQ/kgbw/day. The combined consumption of beef, pork, and chicken was found to be 84.8g per day for a person weighing 60kg and represented 5.7% of their total daily food intake.

Interaction of stem cells with nano hydroxyapatite-fucoidan bionanocomposites for bone tissue regeneration.

The combination of bioceramics with biopolymers are playing major role in the construction of artificial bone. Hydroxyapatite (HA) has been extensively studied as a material in bone repair and replacement in last two decades. In the present study, we have prepared the hydroxyapatite-fucoidan (HA-Fucoidan) nanocomposites by in situ chemical method and biologically characterized them for bone graft substitute. Biological results inferred that mineralization effect of HA-F nanocomposites shows significant enhancement compared to HA in adipose derived stem cell (ADSC). It may be due to the addition of fucoidan in the nanocomposites. The important gene expression such as osteocalcin, osteopontin, collagen and runx-2 were checked using ADSC with HA and HA-fucoidan nanocomposites and the results show that the enhancements were found at 7th day. Furthermore, we have performed in vivo study of HA-fucoidan nanocomposites with rabbit model and a slight amount of bone formation was observed in HA-fucoidan nanocomposites. Herewith, we suggest that HA-fucoidan nanocomposites will be good biomaterials for bone repair/replacement in future.

Determination of the absorbed dose rate to water for the 18-mm helmet of a gamma knife.

PURPOSE: To measure the absorbed dose rate to water of (60)Co gamma rays of a Gamma Knife Model C using water-filled phantoms (WFP). METHODS AND MATERIALS: Spherical WFP with an equivalent water depth of 5, 7, 8, and 9 cm were constructed. The dose rates at the center of an 18-mm helmet were measured in an 8-cm WFP (WFP-3) and two plastic phantoms. Two independent measurement systems were used: one was calibrated to an air kerma (Set I) and the other was calibrated to the absorbed dose to water (Set II). The dose rates of WFP-3 and the plastic phantoms were converted to dose rates for an 8-cm water depth using the attenuation coefficient and the equivalent water depths. RESULTS: The dose rate measured at the center of WFP-3 using Set II was 2.2% and 1.0% higher than dose rates measured at the center of the two plastic phantoms. The measured effective attenuation coefficient of Gamma Knife photon beam in WFPs was 0.0621 cm(-1). After attenuation correction, the difference between the dose rate at an 8-cm water depth measured in WFP-3 and dose rates in the plastic phantoms was smaller than the uncertainty of the measurements. CONCLUSIONS: Systematic errors related to the characteristics of the phantom materials in the dose rate measurement of a Gamma Knife need to be corrected for. Correction of the dose rate using an equivalent water depth and attenuation provided results that were more consistent.