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Biomedical subjects

X M Hu

Publications and source records attributed to X M Hu.

At least 19 recordsLinked to original sources
PubMed2007

Kinetics of plasmid transfer among Bacillus cereus group strains within lepidopteran larvae.

The cry toxin encoding plasmid pHT73 was transferred from Bacillus thuringiensis subspecies kurstaki KT0 to six B. cereus group strains in three lepidopteran (Spodoptera exigua, Plutella xyllostella and Helicoverpa armigera) larvae by conjugation. The conjugation kinetics of the plasmid was precisely studied during the larval infection using a new protocol. The infections were performed with both vegetative and sporulated strains. However, larval death only occurred when infections were made with spore and toxin preparations. Likewise, spore germinations of both donor and recipient strains were only observed in killed larvae, 44-56 h post-infection. Accordingly, kinetics showed that gene transfer between B. thuringiensis strain KT0 and other B. cereus strains only took place in dead larvae among vegetatively growing bacteria. The conjugational transfer ratios varied among different strain combinations and different larvae. The highest transfer ratio reached 5.83 x 10(-6) CFU/donor between the KT0 and the AW05R recipient in Helicoverpa armigera, and all transconjugants gained the ability to produce the insecticidal crystal. These results indicated that horizontal gene transfer among B. cereus group strains might play a key role for the acquisition of extra plasmids and evolution of these strains in toxin susceptible insect larvae.

Animals↗
PubMed2002

Characteristics of a bioflocculant produced by Bacillus mucilaginosus and its use in starch wastewater treatment.

A bioflocculant, MBFA9, was produced from a strain of bioflocculant-producing bacteria isolated from a soil sample and identified as Bacillus mucilaginosus. MBFA9 had a good flocculating capability and could achieve a flocculating rate of 99.6% for kaolin suspension at a dosage of only 0.1 ml/l. The major component of MBFA9 was found to be polysaccharide composed mainly of uronic acid (19.1%), neutral sugar (47.4%) and amino sugar (2.7%). Infrared spectrum analysis showed the presence of carboxyl and hydroxyl groups in the bioflocculant. MBFA9 is nontoxic and can be used in food industries for suspended solids (SS) recovery. When applied to starch wastewater treatment, MBFA9 greatly accelerated the formation of flocs and the settling of organic particles in the presence of Ca(2+) salt. After 5 min of settling, the removal rate of SS and chemical oxygen demand were up to 85.5% and 68.5%, respectively, which is better than traditional chemical flocculants.

Bacillus↗
PubMed2001

[Analysis of the mitochondria-related protein of Schistosoma japonicum and its antigen epitopes].

OBJECTIVE: To sequence the cloned gene Sj338 and to identify the encoded protein and its antigen epitopes. METHODS: The Sj338 gene fragment obtained from adult S. japonicum cDNA library amplified by PCR method was subcloned into pGEM-T vector for sequencing. The sequence of nucleotides and the characteristics of the encoded protein were analyzed by DNASIS Program and Goldkey DNA and Protein Analytical Program, and then the homology of the amino acid sequence was searched on the BLAST net. RESULTS: The cloned rSj338 gene was demonstrated to be 487 bp containing one 459 bp ORF, encoding a protein consisted of 153 amino acids with a molecular weight of 17.6 kDa. The amino acid sequence of the recombinant protein rSj338 shared 46% identity with that of the corresponding part of human mitochondrial import receptor and 44% identity with that of the Rattus sp. mitochondrial precursor receptor. The possible antigen epitopes were predicted within the peptide fragments of 26-32 aa, 37-46 aa and 147-151 aa. CONCLUSION: The protein encoded by rSj338 gene fragment might be the mitochondria-related protein of Schistosoma japonicum.

Amino Acid Sequence↗
PubMed2001

[Clonning and identification of the gene encoding specific IgE antibody-related antigen of Schistosoma japonicum].

OBJECTIVE: To obtain the gene encoding specific IgE-related antigen of Schistosoma japonicum from the cDNA library of adult Schistosoma japonicum. METHODS: The pooled sera from 15 individuals with high levels of specific IgE antibody against SWAP were absorbed with Protein-G and used for screening of IgE-related antigen from the adult worm cDNA library of Schistosoma japonicum. The inserted cDNA was amplified by PCR and sequenced. According to the first reading frame of the sequence, a pair of new probes, in which EcoR I and Not I sites were incorporated respectively, were designed and used to amplify the target gene. Then, the gene was cloned into vector pGEM-T and subcloned into expression vector pGEX-6p-1. The fusion protein was expressed, analysed by SDS-PAGE and identified by Western blotting with the specific IgE antibody, respectively. RESULTS: The inserted cDNA fragment from the positive clone was about 1,200 bp, with the ORF of 507 bp which encoded 169 amino acids. The deduced molecular weight of the recombinant protein was 19.3 kDa. The homology between the target gene (Sj43B) and other known DNA sequences was less than 40%. The fusion protein expressed by the recombinant vector pGEX-6p-1/Sj43B could be recognized by schistosome specific IgE antibody. CONCLUSION: Sj43B may encode the specific IgE-related antigen of Schistosoma japonicum. The successful construction of recombinant plasmid pGEX-6p-1/Sj43B lay the groundwork for further studies on immunological characteristics and protection immunity of the recombinant protein.

Animals↗
PubMed2001

[The calculation-improving of stress amplification coefficient and the checking of its trouble-shooting model].

Through mechanical analysis, it is discovered that the twined structure decides the amplification coefficient of the catgut tension. Many troubles of production can be explained with this mechanics model, and it could be used as a reference for medical sutures. The paper gives an accurate calculating formula for catgut design and its direct tensile strength through improving mechanics model. It can raise the material strength from 10 to over 31% depending on its twined structure.

Algorithms↗
PubMed2000

[Gene cloning and characterization of mitochondria-related protein of Schistosoma japonicum].

OBJECTIVE: To subclone and characterize a cDNA clone coding for Schistosoma japonicum (S.j.) mitochondria-related protein. METHODS: The open reading frame of the fragment(Sj338/24) obtained from an adult worm cDNA library of S.j. was analysed, at the upstream and downstream of the open reading frame(ORF) the primers A and B were designed, respectively, and the cDNA fragment was used as PCR template. The Sj338 gene fragment obtained was amplified by PCR method and then subcloned into pGEM-T vector for sequencing. The gene sequence was analyzed and the target fragment was restrictedly digested and subcloned into expression vector pGEX-6P-1. The expressed recombinant protein was purified and characterized. RESULTS: The cloned Sj338 gene was demonstrated to be 487 bp long containing one 459 bp ORF, encoding a protein with a molecular weight of 17 kDa. The nucleotide sequence of the cloned gene Sj338 had higher homology with those genes coding for mitochondrial outer membrane protein of Homo sapiens and Rattus norvegicus. The recombinant construct of pGEX-6P-1/Sj338 could be expressed efficiently and the antigenicity of its product rSj338 has been demonstrated by Western blotting. CONCLUSION: Sj338 may be the gene coding for S.j. mitochondria-related protein and the recombinant protein may be used as a new vaccine candidate.

Amino Acid Sequence↗
PubMed1993

[Stability of liensinine injection].

The stability of liensinine injection was studied by accelarating test with classical isothermal method. Results of the study showed that the decomposition of the injection was found to be a first-order reaction. The activation energy was 75030 J.mol-1. The shelf life at 10 degrees C and 25 degrees C was predicted to be about 15 months and 3 months respectively. This experiment provides a reference for the storage of the injection.

Chromatography, Thin Layer↗
PubMed1986

Immunization of neonates with trivalent oral poliomyelitis vaccine (Sabin).

A study was carried out between November 1981 and April 1982 on the immunological effect of administering trivalent live, oral polio vaccine to 200 mature healthy neonates from Henan Province, China. The initial dose of vaccine was given at 3 days of age, and 2 months thereafter antibodies to poliovirus types 1, 2, and 3, respectively, were detected in 46.7%, 60.7% and 48.6% of the neonates; after the second dose, the levels were 86.9%, 95.3%, and 97.2%, with geometric mean titres of 1:106.2, 1:349.8, and 1:232.5. Almost 100% of neonates exhibited antibodies after the fourth dose of vaccine. Eighty-two percent of the neonates excreted poliovirus for at least a week after the initial dose of vaccine, and this increased to 99% after the second dose. Seroconversion at 4 months of age was similar to that of a group of controls who received their initial dose of vaccine at 2 months of age; however, immunization of neonates induced immunity to poliovirus at the earliest possible age.

China↗