Reappraisal of the Mawangdui Han Tomb Cadaver Thirty Years After Its Unearthing.

The Mawangdui tomb No.1 cadaver, a female corpse from the Western Han Dynasty, was unearthed in 1972. Forensic examination at the time of discovery indicated fairly remarkable presence of bodily constituents at the anatomical, histological, and molecular levels. The cadaver was preserved in a formalin-based fixative afterward, and maintained in the Hunan Museum. To better protect this rare human corpse, a reappraisal of the status of preservation was carried out using noninvasive approaches, including X-ray radiography, gross anatomical examination, and histological, microbiological, and molecular analyses of sampled tissues. The cadaver remained essentially intact from a gross anatomical perspective, with radiography of the skeletal system and arterial contrast filling appeared comparable with the original documentation. The light microscopic features of the skin, cartilage, and skeletal muscle remained detectable, as were the stratified ultrastructure of the collagen and muscle fibers. The levels of nitrogen and amino acidic elements appeared elevated in the cadaver and liver preservation fixatives, with a higher calcium and phosphate concentration in the former. These findings suggest that there existed a certain degree of macromolecule degradation and bone decalcification in the cadaver, likely irrelevant to biological decomposition. The reappraisal also led to the implementation of stronger scientific measures to better protect the cadaver through a renovated Museum-University coadministrative management agreement.

[Expression of Class I integrase gene in Acinetobacter baumannii and drug-resistance].

OBJECTIVE: To explore the expression level of class I integrase (intI 1) mRNA in Acinetobacter baumannii from biofilm cells and planktonic cultured cells ,and to analyze the drug-resistance of Class I integron positive strains. METHODS: Acinetobacter baumannii were collected from hospitals,and Class I integron strains were screened by gene amplification. Total RNA of Class I integron positive strains was extracted, and the intI1 mRNA expression in the bioflim cells and planktonic cultured cells was measured by RT-PCR. Susceptibilities to antibiotics of Class I integron positive strains were also examined. RESULTS: The intI1 gene mRNA was expressed under 2 conditions, and the mRNA expressed in the biofilm cells was about 4 times higher than that in the planktonic cultured cells. Among the 64 strains of Acinetobacter baumannii, 46 strains were Class I integron positive strains. The antibiotic resistance of intI1 gene cassette-positive strains was higher than that of gene cassette-negative strains. CONCLUSION: The intI1 gene mRNA can be up-regulated in Acinetobacter baumannii biofilm cells.Class I integron plays an important role in drug resistance. It is much easier to capture gene cassettes for bacteria under biofilm condition.

[Function and gene expression of the active efflux transporters in drug-resistant Candida albicans].

OBJECTIVE: To investigate the function and gene expression of active efflux transporters in drug-resistant candida albicans. METHODS: The broth microdilution method was performed to determined the minimal inhibitory concentration of 4 antifungal drugs to 20 candida albicans. We compared the efflux of Rhodamine 6G between sensitive and some of fluconazole-resistant candida albicans, and screened out the resistant strains with significantly increased efflux of Rhodamine 6G. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure the mRNA levels of active efflux gene CDR1 and CDR2. RESULTS: The efflux of Rhodamine 6G was significantly increased in some fluconazole-resistant strains when glucose was added, and the gene expressions of CDR1 and CDR2 were also obviously increased, compared with those in the sensitive strains. CONCLUSION: The excessive expression of active efflux pump gene is related to the resistance to fluconazole in candida albicans. The measurement of Rhodamine 6G efflux is a useful method for the identification of drug-resistant strains induced by the excessive expression of active efflux pump.

[Multiple resistance of neisseria gonorrhoeae and mutations in the inverted sequence within the mtrR promoter region].

OBJECTIVE: To evaluate the correlation between multiple resistance of Neisseria gonorrhoeae and mutations in the inverted sequence within the mtrR promoter region. METHODS: The susceptibilities of 56 Neisseria gonorrhoeae to 5 antibiotic agents were tested by disc diffusion method. 13 bp inverted sequences positioned within the mtrR promoter region were amplified by PCR and examined by single strand conformation polymorphism technology. According to the results of SSCP, 12 strains were selected and were directly sequenced, and their nucleotide sequences were compared with those of susceptible strain ATCC19 424. RESULTS: In the 56 strains of Neisseria gonorrhea, 5 strains were susceptible to all antibiotics and 22 strains were resistant to one antibiotic agent. In the 19 strains that were resistant to 2 antibiotic agents, 2 had mutations in a 13 bp inverted sequence positioned within the mtrR promoter region. Another 7, 2 and 1 strain which was resistant to 3,4 and 5 antibiotic agents respectively all had mutations in a 13 bp inverted sequence positioned within the mtrR promoter region. All of the 12 strains which contained the same mutation exhibited a single base pair deletion in a 13 bp inverted sequence positioned within the mtrR promoter region. CONCLUSION: Deletions in the 13 bp inverted sequence positioned within the mtrR promoter region mediate multiple resistances in Neisseria gonorrhoeae. A single base pair deletion in a 13 bp inverted sequence positioned within the mtrR promoter region is associated with multiple resistance.

[Antibiotic susceptibility of Neisseria gonorrhoeae epidemic strains in Changsha].

OBJECTIVE: To evaluate the antibiotic susceptibility of Neisseria gonorrhoeae epidemic strains in Changsha and to provide a reference for the prevention and treatment of gonorrhea. METHODS: beta-Lactamase was determined by a modified iodometric method and the susceptibility to 9 antibiotic agents was tested by the disc diffusion method in 86 isolates. RESULTS: Plasmid-mediated penicillinase-producing Neisseria gonorrhoeae and plasmid-mediated tetracycline-resistant Neisseria gonorrhoeae were 40.69% and 23.26%, respectively. Of all the 9 antibiotic agents, tetracycline, cefmetazole, penicillin, ciprofloxacin, and ofloxacin had a higher resistance and the percentages of resistance were 45.35%, 50.00%, 62.79%, 77.91%, and 87.21%, respectively. On the other hand, cefuroxime, ceftriaxone, cefepime, and spectinomycin had a higher susceptibility and the percentages of susceptibility were 77.91%, 80.23%, 86.05%, and 98.84%, respectively. CONCLUSION: Penicillin, tetracycline and fluoroquinolone can not be used as routine agents to cure gonorrhea; and spectinomycin can be used as primary medicine to cure gonorrhea in Changsha, but clinical doctors need to pay more attention to it because resistant strains have come into existence.