The functional and regulatory entities underlying free and peptide-bound amino acid transporters in the bovine mammary gland.

Free and peptide-bound AA act as building blocks and key regulators of milk protein. To improve milk protein production, mammary epithelial cells of lactating mammals require extensive AA movement across the plasma membrane via multiple transport systems. Recent studies on bovine mammary cells/tissues have expanded the number of AA transporter systems identified and the knowledge on their contribution to AA utilization for milk protein synthesis and the regulatory machinery. However, in lactating cows, the exact intracellular location of mammary AA transporters and the extent of mammary net AA utilization for milk protein production remain unclear. This review highlights the existing knowledge on various characteristics, such as substrate specificity, kinetics, their effects on AA uptake and utilization, and regulatory mechanism, of recently examined bovine mammary free and peptide-bound AA transporters.

[Clinical characteristics and treatment of diabetic patients with superficial partial-thickness burn on feet].

Objective: To analyze the characteristics and treatment of diabetic patients with superficial partial-thickness burn on feet. Methods: Eighty-three patients with superficial partial-thickness burn on 119 feet were hospitalized in our unit from January 2011 to December 2017. The medical records of the patients with 46 men and 37 women, aged 60±11 were retrospectively analyzed. The patients were divided into diabetes group and non-diabetes group according to whether they had diabetes or not, with 41 patients (60 burn feet) in diabetes group and 42 patients (59 burn feet) in non-diabetes group. Patients in diabetes group and non-diabetes group were given systemic treatment and wound dressing change. Thirty-seven diabetic patients whose wounds deepened to deep partial-thickness were divided into eschar shaving group and non-eschar shaving group according to patients' willingness and the treatment, with 14 patients in eschar shaving group and 23 patients in non-eschar shaving group. Patients in eschar shaving group were given eschar shaving operation at early stage, and patients in non-eschar shaving group were given wound dressing change. The length of hospital stay, hospitalization treatment expenses, pulse of arteria dorsal pedis and posterior tibial artery immediately after admission, deepening of wounds on feet during hospital stay, and rates of wound healing on feet of patients in diabetes group and non-diabetes group were observed and calculated. Pulses of arteria dorsal pedis and posterior tibial artery immediately after admission, deepening of wounds on feet during hospital stay, positive rates of bacteria and fungus in wounds on feet, and rates of wound healing on feet of patients in eschar shaving group and non-eschar shaving group were observed and calculated. Data were processed with chi-square test, t test, Fisher's exact propability method, and Mann-Whitney U test. Results: The length of hospital stay of patients in diabetes group was (29±20) d, which was significantly longer than that of patients in non-diabetes group [(19±13) d, t=2.730, P<0.01]. The hospitalization treatment expense of patients in diabetes group was (46 988±41 322) yuan, which was significantly more than that of patients in non-diabetes group [(29 106±24 813) yuan, t=2.396, P<0.05]. The pulses of arteria dorsal pedis and posterior tibial artery of patients in diabetes group were significantly weaker than those of patients in non-diabetes group (Z=3.278, 2.194, P<0.05 or P<0.01). The percentages of wounds on feet of patients in diabetes group deepening to deep partial-thickness burn, full-thickness skin defect with bone and tendon exposure were respectively 88.3% (53/60) and 23.3% (14/60), which were significantly higher than those of patients in non-diabetes group [47.5% (28/59) and 1.7% (1/59), χ(2)=22.867, 12.644, P<0.01]. Rate of wound healing on feet of patients in diabetes group was 78.3% (47/60), which was significantly lower than 100.0% (59/59) of patients in non-diabetes group ( χ(2)=14.351, P<0.01). There were respectively 21 and 32 feet in patients of eschar shaving group and non-eschar shaving group. There were no significantly statistical differences in pulses of arteria dorsal pedis and posterior tibial artery of patients between eschar shaving group and non-eschar shaving group (Z=0, 0.453, P>0.05). The percentage of wounds on feet of patients in non-eschar shaving group deepening to full-thickness skin defect with bone and tendon exposure was 43.8% (14/32), which was significantly higher than 0 of patients in eschar shaving group ( χ(2)=12.486, P<0.01). Positive rates of bacteria and fungus in wounds on feet of patients in eschar shaving group was significantly lower than that of patients in non-eschar shaving group (χ(2)=4.386, P<0.05 ). Rate of wound healing on feet of patients in non-eschar shaving group was 59.4% (19/32), which was significantly lower than that of patients in eschar shaving group [100.0% (21/21), P<0.01]. Conclusions: Diabetes patients with superficial partial-thickness burn wounds on feet has long length of hospital stay, high hospitalization treatment expenses. Wounds of the patients are easy to deepen, with low wound healing rate. Eschar shaving at early stage when the wounds deepened to deep partial-thickness burn is a good way to increase wound healing rate and prevent further deepening of wounds.

Seryl-tRNA synthetase-mediated essential amino acids regulate ß-casein synthesis via cell proliferation and mammalian target of rapamycin (mTOR) signaling pathway in bovine mammary epithelial cells.

Essential amino acids (EAA) play an important role in promoting milk protein synthesis in primary bovine mammary epithelial cells (BMEC). However, the regulatory mechanisms involved in the relationship between EAA and milk protein synthesis have not been fully explored. This study examined the effects of seryl-tRNA synthetase (SARS) on EAA-stimulated ß-casein synthesis, cell proliferation, and the mammalian target of rapamycin (mTOR) system in BMEC. First, BMEC were cultured in medium either lacking all EAA (-EAA) or that included all EAA (+EAA) for 12 h. The BMEC were then supplemented with the opposing treatments (-EAA supplemented with +EAA and vice versa) for 0 h, 10 min, 0.5 h, 1 h, 6 h, or 12 h, respectively. After the treatment-specific time allotment, proteins were collected for Western blotting. Subsequently, a 2 × 2 factorial design was used to evaluate the interactive of SARS inhibition (control or SARS inhibited) and EAA supply (+EAA or -EAA) on gene and protein abundance, cell viability, and cell cycle in BMEC. Based on the data obtained in the first experiment, the changes in protein abundance of ß-casein and SARS depended on EAA treatment time in similar patterns. The protein abundance of ß-casein, SARS, and mammalian target of rapamycin (mTOR)-related proteins, cell viability, cell cycle progression, and the mRNA abundance of cyclin D1 (CCND1, cell cycle progression marker) and marker of proliferation Ki-67 (MKI67, cell proliferation marker) were stimulated by the presence of EAA. Correspondingly, when cells were deprived of EAA, cell proliferation and abundance of these proteins and genes were reduced overall. Moreover, the decreases in these aspects were further exacerbated by inhibiting SARS, suggesting that an interaction between EAA and SARS is important for regulating protein synthesis. The results indicated that SARS stimulated the mTOR signaling pathway when EAA were present, enhanced EAA-stimulated cell proliferation, and contributed to increased ß-casein production in BMEC.

Short communication: Comparative proteomic analysis of the lactating and nonlactating bovine mammary gland.

The objective of this study was to determine how bovine mammary protein profiles vary during lactation and the dry period. Three lactating and 3 nonlactating cows were selected for mammary gland tissue sampling. Compared with the mammary proteins in nonlactating cows, a total of 60 differentially expressed proteins (DEP, including 57 upregulated and 3 downregulated) were identified in lactating cows using 2-dimensional difference gel electrophoresis combined with mass spectrometry. These DEP included enzymes and proteins associated with various macromolecular metabolic processes, and appeared to promote the increased metabolic activity associated with milk synthesis and secretion. The increased DEP were primarily related to initiation, maintenance, and involution of lactation, and included proteins involved in glycolysis/gluconeogenesis, the tricarboxylic acid cycle, the pentose phosphate pathway, oxidative phosphorylation, aminoacyl-transfer RNA biosynthesis, and fatty acid biosynthesis. Identified DEP were further validated by real-time, reverse-transcription PCR and Western blot. Five new DEP associated with lactation were uniquely identified. This work provided some protein-associated insights to facilitate further investigation of the mechanisms underlying lactation in dairy cows.

Spatiotemporal distribution of carbonyl compounds in China.

A sampling campaign was carried out at nine Chinese cities in 2010/2011. Fifteen monocarbonyls (C# = 1-9) were quantified. Temperature is the rate-determining factor of the summertime carbonyl levels. The carbonyl emissions in winter are mainly driven by the primary anthropogenic sources like automobile. A molar ratio of propionaldehyde to nonaldehyde is a barometer of the impact of atmospheric vegetation emission which suggesting that strong vegetation emissions exist in summer and high propionaldehyde abundance is caused by fossil fuel combustion in winter. Potential health risk assessment of formaldehyde and acetaldehyde was conducted and the highest cumulative risks were observed at Chengdu in summer and Wuhan in winter. Because of the strong photochemical reaction and large amount of anthropogenic emissions, high concentrations of carbonyl compounds were observed in Chengdu. The use of ethanol-blended gasoline in Wuhan is the key reason of acetaldehyde emission and action should be taken to avoid potential health risks.

Evaluation of hazardous airborne carbonyls on a university campus in southern China.

A comprehensive assessment of indoor carbonyl compounds for the academic staff workers, and students was conducted on a university campus in Xiamen, China. A total of 15 representative environment categories, including 12 indoor workplaces and three residential units, were selected. The potential indoor pollution sources were identified based on the variability in the molar compositions and correlation analyses for the target carbonyls. Furnishing materials, cooking emissions, and electronic equipment, such as photocopiers, can generate various carbonyls in the workplace. Comparison studies were conducted in the clerical offices, demonstrating that off-gases from wooden furniture and lacquer coatings, environmental tobacco smoke (ETS), and the use of cleaning reagents elevated the indoor carbonyl levels. The measured concentrations of formaldehyde and acetaldehyde in most locations surpassed the exposure limit levels. The lifetime cancer hazard risk (R) associated with formaldehyde was above the concern risk level (1 x 10(-6)) in all of the workplaces. The results indicate that formaldehyde exposure is a valid occupational health and safety concern. Wooden furniture and refurbishing materials can pose serious health threats to occupants. The information in this study could act as a basis for future indoor air quality monitoring in Mainland China. Implications: A university campus represents a microscale city environment consisting of all the working, living, and commercial needs of staff and students. The scope of this investigation covers 21 hazardous carbonyl species based on samples collected from 15 categories of workplaces and residential building in a university campus in southern China. Findings of the study provide a comprehensive assessment of indoor air quality with regards to workers' health and safety. No similar study has been carried out in China.

Seasonal variations of monocarbonyl and dicarbonyl in urban and sub-urban sites of Xi'an, China.

Seventeen airborne carbonyls including monocarbonyls and dicarbonyls were determined in urban and sub-urban sites of Xi'an, China in three seasons in 2010. In winter, acetone was the most abundant carbonyl in the urban site due to usage of organic solvents in constructions and laboratories and its slower atmospheric removal mechanisms by photolysis and reaction with hydroxyl radical than those of formaldehyde and acetaldehyde. In the sub-urban site, acetaldehyde was the most abundant carbonyl, followed by formaldehyde and acetone. During summer, however, formaldehyde was the most dominant carbonyl in both sites. The photooxidations of a wide range of volatile organic compounds (VOCs) yielded much more formaldehyde than other carbonyls under high solar radiation and temperature. In the urban site, the average concentrations of dicarbonyls (i.e., glyoxal and methyglyoxal) in spring and summer were higher than that in winter. Transformation of aromatic VOCs emitted from fuel evaporation leads to the formation of 1,2-dicarbonyls. A reverse trend was observed in sub-urban sites, as explained by the relatively low abundances and accumulations of VOC precursors in the rural atmosphere during warm seasons. Moreover, cumulative cancer risk based on measured outdoor carbonyls (formaldehyde and acetaldehyde) in Xi'an Jiaotong University and Heihe was estimated (8.82 × 10(-5) and 4.96 × 10(-5), respectively). This study provides a clear map on the abundances of carbonyls and their source interpretation in the largest and the most economic city in Northwestern China.

Fabrication and Evaluation of Curcumin-loaded Nanoparticles Based on Solid Lipid as a New Type of Colloidal Drug Delivery System.

Curcumin has very broad spectrum of biological activities; however, photodegradation, short half-life and low bioavailability have limited its clinical application. Curcumin-loaded solid lipid nanoparticles were studied to overcome these problems. The aim of this study was to optimize the best formulation on curcumin-loaded solid lipid nanoparticles. Emulsion-evaporation and low temperature-solidification technique was applied with monostearin as lipid carriers. The single factor analysis and orthogonal design were used to optimize formulation and various parameters were investigate. By the optimisation of a single factor analysis and orthogonal test, the particles size, polydispersity index, zeta potential, encapsulation efficiency and drug loading capacity of the optimised formulation were 99.99 nm, 0.158, -19.9 mV, 97.86%, and 4.35%, respectively. The differential scanning calorimetry and X-ray diffraction analysis results demonstrated new structure was formed in nanoparticles. The release kinetics in vitro demonstrated curcumin-loaded solid lipid nanoparticles can control drug release. These studies confirmed that curcumin-loaded solid lipid nanoparticles could be prepared successfully with high drug entrapment efficiency and loading capacity. Curcumin-loaded solid lipid nanoparticles may be a promising drug delivery system to control drug release and improve bioavailability.