[COⅠ and 16S rDNA Sequence Identification of Common Necrophagous Flies in Fujian Province]

Abstract

Objective To identify the species of common necrophagous flies in Fujian Province by gene fragment sequences of mitochondrial cytochrome c oxidase subunit Ⅰ （COⅠ） and 16S ribosomal deoxyribonucleic acid （16S rDNA）, and to explore the identification efficacy of these two molecular markers. Methods In total 22 common necrophagous flies were collected from the death scenes in 9 different regions in Fujian Province and DNA was extracted from the flies after morphological identification. The gene fragments of COⅠ and 16S rDNA were amplified and sequenced. All the sequences were uploaded to GeneBank and BLAST and MEGA 10.0 software were used to perform sequence alignment, homology analysis and intraspecific and interspecific genetic distance analysis. The phylogenetic trees of DNA fragment sequences of COⅠ and 16S rDNA of common necrophagous flies in Fujian Province were established by unweighted pair-group method with arithmetic means （UPGMA）, respectively. Results The flies were classified into 6 species, 5 genera and 3 families by morphological identification. The results of gene sequence analysis showed that the average number of interspecific and intraspecific genetic distance of 16S rDNA ranged from 1.8% to 8.9% and 0.0% to 2.4%, respectively. The average number of interspecific and intraspecific genetic distance of COⅠ ranged from 7.2% to 13.6% and 0.0% to 6.3%, respectively. Conclusion The gene sequences of COⅠ and 16S rDNA can accurately identify the species of different necrophagous flies, and 16S rDNA showed higher value in species identification of common calliphoridae necrophagous flies in Fujian Province.

Studies on expression of p14ARF and MDM2 in human thyroid neoplasms

AIM

We sought to evaluate the expression and clinical significance of p14ARF and MDM2 proteins in thyroid neoplasm.

METHODS

Immunohistochemical streptavidin-peroxidase (S-P) method was used to detect the expression of p14ARF and MDM2 proteins in 78 cases of papillary thyroid carcinoma (PTC), 34 cases of papillary thyroid microcarcinoma (PTMC) and 45 cases of thyroid adenoma.

RESULTS

The expression of p14ARF and MDM2 protein differed significantly (P<0.01) among three group. The positivity rate of p14ARF protein in PTC was significantly lower than that in thyroid adenoma (P=0.002) and PTMC (P=0.008). While the positivity rate of MDM2 protein in PTC was significantly higher than that in thyroid adenoma (P=0.000) and PTMC (P=0.009). There was a significant correlation found between the expressions of p14ARF and MDM2 proteins in PTC (P=0.013) and PTMC (P=0.012). Also, a significant correlation was found between p14ARF protein expression and lymph node metastasis in PTC (P=0.011).

CONCLUSION

It was concluded that p14ARF and MDM2 proteins might be involved in the induction and development of PTC and PTMC whereas p14ARF also had diagnostic value in determining the biological behavior of PTC.

[A study of the relation between interval of the injury and the reaction of neurons, glial cells after experimental brain contusion]

OBJECTIVE

To observe the change of c-fos protein(Fos) and nerve growth factor receptor (NGFR) staining in the brain of rat after experimental brain contusion.

METHODS

Immunohistochemistry of c-fos and NGFR were applied to investigate the brain contusion.

RESULTS

(1) The expression of Fos protein could be observed at 0.5 h after injury and then increased with the prolonging of time. By 3 h after injury, the positive staining cells could be detected massively not only in and round the wound site but also in other areas of the whole ipsilateral cortex. The stains decreased 6-12 h later and could hardly be detected 1 d after the brain contusion. The control-experiment is negative. (2) NGFR positive staining cells could be found round the wound area 1 d postlesion. At 3 d following injury, a peak of massive positively stained cells appeared both in number and in intensity, showing significant differences compare with that of 1 d after damage (P < 0.01). 5 d later the positive express declined slowly. The express in the control-rat is negative.

CONCLUSION

There is a rule that the expression of Fos and NGFR positive staining changes with time going after brain contusion, which will be of great value in estimation of brain injury time. Detection of Fos can be used for time deduction in earlier period after injury, while NGFR in later period. They are also very important for distinguishing between antemortem or postmortem injury.

[The expression of Pax7 in C2C12 cell line and its inducible inactivation]

Pax7 is a member of mouse Pax gene family. It was expressed from day 8 to 17 p. c. during murine embryogenesis, mainly restricted to the central nerve systems. Additional Pax7 expression could be followed during myogenesis from the dermamyotome of the somites to the skeletal muscle tissues. For the first time, we demonstrated that Pax7 is expressed in mouse myoblast cell line, C2 C12. The expression of Pax7 was blocked when C2 C12 cells were induced to differentiate into myotube. Moreover, cells of mesodermal origin, in particular of the mouse embryo fibroblast cell line C3 H10 T1/2 which were especially permissive to the action of myogenic HLH proteins, did not express Pax7. These results suggest that Pax7 may be a suppressive factor for the myoblast differentiation of C2 C12 cells in vitro.

[Expression of exogenous porcine transforming growth factor beta-1 gene in ES cells and its effect on their differentiation in vitro]

A TGF-beta 1 gene expression plasmid was constructed by inserting the porcine 1.7 Kb TGF-beta 1 cDNA into BamHI site of retrovirus vector Dol. The plasmid DNA was introduced into mouse embryonic stem cells (ES-5 line) by calcium phosphate mediated transfection, and transfected ES-5 cells were then selected by stepwise increase in G418 concentration. Finally, we obtained 21 clones that could be stably grown in culture medium with G418 at 500 micrograms/ml and were designated as ES-T cells. Dot blot and Northern analysis of total RNA and polyA+ RNA extracted from those ES-T cells were shown in FIg. 2 and 3, demonstrating that 6 clones could express exogenous porcine TGF-beta 1 mRNA. The stronger hybridized signal in two clones (ES-T6 and ES-T 16) of them were further proved by southern hybridization of genomic DNA from these ES-T cells with 1.7 Kb TGF-beta 1 cDNA probe (Fig. 4). The product of TGF-beta 1 gene overexpression in ES-T 6 cells was shown in Fig. 5 and 6 by SE-LISA for TGF-beta 1 immunoreactivity to TGF-beta 1 antibodies and biological assay for CCL/64 cell growth inhibition, respectively. With respect to some biological characteristics, ES-T 6 cells, like their parent ES-5 cells, retained their pluripotent properties and positive SSEA-1 antigen (Plate I, Fig. 1). ES-T6 cells were expanded and used for studies of in vitro differentiation. Both of ES-T 6 cells and control ES-5 cells could form a lot of simple aggregates and differentiate into embryoid bodies by hanging drop culture for 3 days in the presence of retinoic acid (RA) at 10(-9) mol/L. Then individual embryoid bodies were plated on gelatinized tissue culture wells. On the third day of further culture without RA, a large amounts of epithelial-like and round cells occurred around the embryoid bodies formed either from ES-T 6 cells or ES-5 cells (Plate I, Fig. 4). However, with further culture of embryoid bodies, only the cells differentiated from ES-T6 embryoid bodies could arrange themselves and differentiate into a lot of radially arranged tubular structures (Plate II, Fig. 5). The frequency of tubular structures present in ES-T6 embryoid bodies were about 95.5%, but in ES-5 group there was only about 17.8% cases giving less defined tubular structures (Plate III, Fig. 8).(ABSTRACT TRUNCATED AT 400 WORDS)