Cosmetic outcome of implantation of cross-linked human acellular dermal matrix after parotidectomy.

Although skin depression after parotidectomy affects the patient's satisfaction with cosmesis we know of little research about it, so we attempted to alleviate it by inserting human acellular dermal matrix (hADM) after the operation. We made a retrospective analysis of the casenotes of 63 patients who were diagnosed with parotid tumours and were operated on between January 2015 and December 2016. Factors that affect satisfaction with cosmesis, including the use of hADM, sex, age, incision, size of tumour, sample size, complications, and the name of the surgeon were recorded and evaluated on a scale from 1 (most unsatisfactory) to 10 (very satisfactory), and the satisfaction according to each factor was compared. The mean (SD) follow-up period was 13 (6) months, and 19 of the 63 patients developed complications. Satisfaction was significantly better when hADM had been inserted (p=0.0008), when the patient was female (p=0.033), or there were no complications p=0.0161). On linear regression analysis, all three factors showed a significant causal relation with satisfactory cosmesis. Insertion of hADM after operations on the parotid gland seems to be effective in improving this by preventing skin depression.

Arsenic exposure and seafood intake in Korean adults.

Arsenic (As) is widely distributed in the environment, and humans can be exposed to As from various sources such as air, water, soil, and food. This study was performed to evaluate the As exposure levels in Korean adults by measuring total As in urine and its relation with the consumption of seafood, a favorite food in Korea. A total of 2077 adults were the study subjects; they ranged in age from 19 to 83, and they were recruited by probability sampling stratified by area, sex, and age. None of the subjects had been exposed to As occupationally. We collected information about the demographic characteristics, lifestyles, and food consumption of study subjects using a questionnaire and followed urine sampling. Diet was assessed in individual interviews using the 24-h recall method. Total As in urine was analyzed using inductively coupled plasma mass spectrometry (PerkinElmer NEXION 300S; Concord, Ontario, Canada). The geometric mean concentration of total As in urine was observed to be 97.6 µg/L and was higher in males (103.9 µg/L) than in females (93.0 µg/L). Total As levels in urine were affected by sex, age, seafood intake, and geographic location. In this study, total As in urine was positively correlated with fish and shellfish consumption, and was mainly determined by As intake through fish and shellfish/grains/flavors. These findings suggest that seafood consumption might be a major contributor to urinary As levels in Korean adults.

Determination of microviscosity and location of 1,3-Di(1-pyrenyl)propane in brain membranes.

We determined the microviscosity of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex and liposomes of total lipids (SPMTL) and phospholipids (SPMPL) extracted from SPMV. Changes in the microviscosity induced by the range and rate of lateral diffusion were measured by the intramolecular excimerization of 1,3-di(1-pyrenyl)-propane (Py-3-Py). The microviscosity values of the direct probe environment in SPMV, SPMTL and SPMPL were 38.17, 31.11 and 27.64 cP, respectively, at 37 degrees C and the activation energies (E(a)) of the excimer formation of Py-3-Py in SPMV, SPMTL and SPMPL were 8.236, 7.448 amd 7.025 kcal/mol, respectively. Probe location was measured by polarity and polarizability parameters of the probe Py-3-Py and probe analogues, pyrene, 1-pyrenenonanol and 1-pyrenemethyl-3beta-hydroxy-22,23-bisnor-5-cholenate (PMC), incorporated into membranes or solubilized in reference solvents. There existed a good linear relationship between the first absorption peak of the(1)L(a) band and the polarizability parameter (n (2)-1)/(2n (2)+1). The calculated refractive index values for SPMV, SPMTL and SPMPL were close to 1.50, which is higher than that of liquid paraffin (n=1.475). The probe location was also determined by using a polarity parameter (f-1/2f(1)). Here f=(epsilon-1)/(2epsilon+1) is the dielectric constant function and f'=(n (2)-1)/(2n (2)+1) is the refractive index function. A correlation existed between the monomer fluorescence intensity ratio and the solvent polarity parameter. The probes incorporated in SPMV, SPMTL, and SPMPL report a polarity value close to that of 1-hexanol (epsilon=13.29). In conclusion, Py-3-Py is located completely inside the membrane, not in the very hydrophobic core, but displaced toward the polar head groups of phospholipid molecules, e.g., central methylene region of aliphatic chains of phospholipid molecules.