STUDY ON A SPECIFIC TEST METHOD FOR DOSIMETRIC CHARACTERIZATION OF ULTRA-WIDE DETECTOR COMPUTED TOMOGRAPHY.

The purpose of this study was to establish a specific test method for dosimetric characterization of wide-beam computed tomography (CT). For a wide beam, the dose distribution curve and the area of the curve were obtained by using pencil-like ionization chamber, a long CT dose profiler probe, a head phantom and a body phantom. The absolute dose conversion coefficient was multiplied to obtain the total integration integral of the absolute dose distribution, and then the computed tomography dose index (CTDI) value under any wide beam condition was obtained by dividing the collimation width. It was calculated that the absolute dose conversion coefficient was 1.135 under the narrow beam of 8 mm. To a 160 mm-wide beam, the value of CTDI was 7.57 mGy/100mAs after normalized in the head 80 kV CT scanning, and it was 9.80 mGy/100mAs after normalized in the body 120 kV CT scanning. The specific test method solves the problem that the previous measurement method underestimates the CTDI value.

Lipid droplet biology and evolution illuminated by the characterization of a novel perilipin in teleost fish.

Perilipin (PLIN) proteins constitute an ancient family important in lipid droplet (LD) formation and triglyceride metabolism. We identified an additional PLIN clade (plin6) that is unique to teleosts and can be traced to the two whole genome duplications that occurred early in vertebrate evolution. Plin6 is highly expressed in skin xanthophores, which mediate red/yellow pigmentation and trafficking, but not in tissues associated with lipid metabolism. Biochemical and immunochemical analyses demonstrate that zebrafish Plin6 protein targets the surface of pigment-containing carotenoid droplets (CD). Protein kinase A (PKA) activation, which mediates CD dispersion in xanthophores, phosphorylates Plin6 on conserved residues. Knockout of plin6 in zebrafish severely impairs the ability of CD to concentrate carotenoids and prevents tight clustering of CD within carotenoid bodies. Ultrastructural and functional analyses indicate that LD and CD are homologous structures, and that Plin6 was functionalized early in vertebrate evolution for concentrating and trafficking pigment.

Endogenous and Synthetic ABHD5 Ligands Regulate ABHD5-Perilipin Interactions and Lipolysis in Fat and Muscle.

Fat and muscle lipolysis involves functional interactions of adipose triglyceride lipase (ATGL), α-ß hydrolase domain-containing protein 5 (ABHD5), and tissue-specific perilipins 1 and 5 (PLIN1 and PLIN5). ABHD5 potently activates ATGL, but this lipase-promoting activity is suppressed when ABHD5 is bound to PLIN proteins on lipid droplets. In adipocytes, protein kinase A (PKA) phosphorylation of PLIN1 rapidly releases ABHD5 to activate ATGL, but mechanisms for rapid regulation of PLIN5-ABHD5 interaction in muscle are unknown. Here, we identify synthetic ligands that release ABHD5 from PLIN1 or PLIN5 without PKA activation and rapidly activate adipocyte and muscle lipolysis. Molecular imaging and affinity probe labeling demonstrated that ABHD5 is directly targeted by these synthetic ligands and additionally revealed that ABHD5-PLIN interactions are regulated by endogenous ligands, including long-chain acyl-CoA. Our results reveal a new locus of lipolysis control and suggest ABHD5 ligands might be developed into novel therapeutics that directly promote fat catabolism.

Characterization of a novel hemolytic activity of human IgG fractions arising from diversity in protein and oligosaccharide components.

Human IgG is a well-established multifunctional antigen specific immunoglobulin molecule of the adaptive immune system. However, an antigen nonspecific immunological function of human IgG has never been reported. In this study, human IgG was isolated using ammonium sulfate fractional precipitation and diethylaminoethanol (DEAE) cellulose 52 ion exchange chromatography, from which h-IgG and hs-IgG fractions were purified on the basis of their differential binding to rabbit anti-shrimp hemocyanin antibody (h) and rabbit anti-shrimp hemocyanin's small subunit antibody (hs), respectively. We found that h-IgG had a higher hemolytic activity than hs-IgG against erythrocytes from humans, rabbits, mice and chickens, whereas the control IgG showed negligible activity. h-IgG could interact directly with erythrocyte membranes, and this interaction was suppressed by high molecular weight osmoprotectants, showing that it may follow a colloid-osmotic mechanism. In comparative proteomics and glycomics studies, h-IgG and hs-IgG yielded 20 and 5 significantly altered protein spots, respectively, on a 2-D gel. The mean carbohydrate content of h-IgG and hs-IgG was approximately 3.6- and 2-fold higher than that of IgG, respectively, and the α-d-mannose/α-d-glucose content was in the order of h-IgG>hs-IgG>IgG. In this study, a novel antigen nonspecific immune property of human IgG was investigated, and the diversity in the protein constituents and glycosylation levels may have functional signficance.

[Effect of nasal cavity expansion surgery on chronic nasal obstructive diseases on the blood supply of the cerebral arterial system].

OBJECTIVE: To investigate the effect of nasal cavity expansion surgery on the abnormal blood supply of the cerebral arterial system. METHODS: Fifty-nine inpatients with abnormal blood supply of cerebral arterial system confirmed by transcranial doppler (TCD) and chronic nasal obstructive diseases were included in this study. All patients accepted nasal cavity expansion surgery and were followed-up with TCD every month after operation until TCD became normal, or up to seven months even if the TCD was still abnormal. SPSS 17.0 software was used to analyze the data. RESULTS: In all 59 patients, there were 164 TCD-abnormal cerebral arteries. Among them, 37 patients(62.71%) with abnormal TCD arteries became normal within 1 to 7 months after operation, 8 patients (13.56 %) got better, but 14 patients (23.73 %) did not improve. CONCLUSIONS: Abnormal blood flow of some cerebral arteries was possibly induced by increasing the activation of sympathetic nervous system around the vertebral arterial system, caused by chronic nasal obstruction. Nasal dilatancy surgery can improve the blood supplement of the cerebral arterial system.

Phylogenetic relationships of the genus Eurytrema from domestic and wild animal based on 18S rRNA sequences.

Since Loss (1907) established the genus Eurytrema, there were more than eleven species found worldwide from America, Europe to Asia. Adult worms are generally found in pancreatic and bile ducts of wild and domestic ruminants. Some species from wild animal and domestic animal have already differentiated. In this study, we amplified and sequenced the partial 18S rRNA sequences of some Eurytrema species found in wild and domestic animals. The phylogenetic analysis was conducted to show the genetic relationship of these Eurytrema species. The results demonstrated that same species of Eurytrema from domestic animal and wild animal or from separated geological region have a considerable degree of genetic differentiation. Analysis of the 18S rRNA sequences indicated that Eurytrema fukienensis is an independent species and suggested that it may represent the intermediate species between wild and domestic animal.

Hemocyanin from shrimp Litopenaeus vannamei shows hemolytic activity.

Hemocyanin is an extracellular copper-containing protein present in the hemolymph of both mollusks and arthropods. The traditionally recognized function of hemocyanin is for oxygen transport. Lately, it was demonstrated that hemocyanin is a multifunctional protein, especially participating in multiple roles of immune defense. For better understanding its actions in immune defense, the hemolytic activity of hemocyanin from shrimp Litopenaeus vannamei and the mechanism were investigated in this study. The results showed that shrimp hemocyanin exhibited hemolytic activity against vertebrate erythrocytes. The hemolysis displayed dependencies on hemocyanin concentration, pH, temperature and divalent cations. The highest activity occurred at a concentration of 0.125 mg ml(-1), and pH 6.0, 40 degrees C in the presence of calcium. Moreover, from the incubation products of erythrocytes with hemocyanin, besides two subunits of hemocyanin, two molecules around 150 and 230 kD were isolated and speculated as oligomers of hemocyanin. Further evidence revealed that the hemolysis could be inhibited to different degrees by osmoprotectants with high molecular masses, suggesting that it follows a colloid-osmotic mechanism. These results indicate that L. vannamei hemocyanin has a novel function with hemolytic activity, partly related to a colloid-osmotic mechanism mediated by its oligomers.