Biomedical subjects
Publications and source records attributed to Z H Hu.
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INTRODUCTION: In order to find a suitable carrier to deliver the product of gene transfection to improve the performance of bioengineered dermis, we used microencapsulation and gene transfection technology together for the first time and found that it was feasible. METHODS: We used a recombinant nerve growth factor (pcDNA3.1+/NGF) to modify NIH3T3 cells genetically. Control of NIH3T3-NGF cells were encapsulated within microspheres composed of alginate-poly-L-lysine-alginate and cultivated in-vitro. The concentration of NGF released from the microencapsulated NIH3T3-NGF cells was confirmed using ELISA assay. We co-cultivated microencapsulated NIH3T3-NGF cells, NIH3T3 cells (control) with human keratinocytes and fibroblasts, and tested the percentage of cycle of these cells. The alkaline hydrolysis method was used to analyse the content of hydroxyproline (Hyp). Immunohistochemistry method was used to calculate the transformation efficiency from fibroblasts to myofibroblasts. RESULTS: The concentration of NGF released from the microencapsulated NIH3T3-NGF cells lasted about six weeks in the supernatant of bioengineered dermis in-vitro. The proliferation of keratinocytes, as well as the concentration of Hyp in supernatant of fibroblasts, were promoted about three times. Transformation efficiency from fibroblasts to myofibroblasts was increased approximately two-fold because of the bio-effects of NGF. Two kinds of microencapsulations were seeded into collagen which contained human fibroblasts to form bioengineered skin. Microencapsulated NIH3T3-NGF cells formed a thicker dermis. The concentration of Hyp in the bioengineered skin which indicated the level of collagen synthesis was increased due to existing NGF. CONCLUSION: Microencapsulated NIH3T3-NGF cells can be used to enhance performance of bioengineered dermis and it also can be deduced that other cytokines can be used to treat local wound areas.
A novel DRB1*15 allele, DRB1*1516, has been identified in a Guangdong Han individual. Its sequence was confirmed by sequencing of polymerase chain reaction products and clones. This allele differed by one nucleotide from DRB1*150101 at position 220 (G-->A), resulting in an amino acid substitution from Gly to Arg at codon 45.
Gene delivery into kidney cells is essential to the development of gene therapy for nephropathy. This paper describes the use of baculovirus Autographa californica nucleopolyhedrovirus (AcMNPV) as a vector for gene delivery into several mammalian kidney cells. High-level expression of a reporter gene encoding for the green fluorescent protein (GFP) under a heterogonous promoter was observed in kidney cells from mouse, hamster, monkey, pig, and human. The level of transgene expression exhibited viral dose dependence and was enhanced by the addition of butyrate. Baculovirus transduction could also provided long-term target gene expression in kidney cell lines without cytotoxic effects. High efficiency transduction was also observed in primary mouse kidney cells. These results indicate that baculovirus can be used as a vector for kidney-directed gene transfer.
Continuous experiments were conducted to study the hydrolysis and acidogenesis of sewage sludge in an upflow reactor with an agitator and a gas-liquid-solid separator. Results of this study showed that 34-78% of volatile suspended solids (VSS) in sewage sludge was hydrolyzed at pH in the range 4.0-6.5, 35 degrees C and 4-24 hours of hydraulic retention time (HRT). About 31-65% of carbohydrate in sewage sludge, 20-45% of protein and 14-24% of lipid were acidified in this reactor. Hydrogen production was favored in lower pH and HRT, whereas methane production was encouraged at higher pH and HRT. Acetate, propionate, butyrate, and i-butyrate were the main aqueous acidogenic products. The distribution of these compounds in the effluent was more sensitive to pH, but was less sensitive to HRT. The maximu specific COD solubilization rate and specific volatile fatty acids production rate were 126 mg-COD/g-VSS x d and 102 mg-VFAIg-VSS x d, respectively. Compared with a CSTR, this modified upflow reactor was shown to be a more promising biosystem for the hydrolysis and acidogenesis of sewage sludge.
The complete nucleotide sequence of Helicoverpa zea single-nucleocapsid nucleopolyhedrovirus (HzSNPV) has been determined (130869 bp) and compared to the nucleotide sequence of Helicoverpa armigera (Ha) SNPV. These two genomes are very similar in their nucleotide (97% identity) and amino acid (99% identity) sequences. The coding regions are much more conserved than the non-coding regions. In HzSNPV/HaSNPV, the 63 open reading frames (ORFs) present in all baculoviruses sequenced so far are much more conserved than other ORFs. HzSNPV has four additional small ORFs compared with HaSNPV, one of these (Hz42) being in a correct transcriptional context. The major differences between HzSNPV and HaSNPV are found in the sequence and organization of the homologous regions (hrs) and the baculovirus repeat ORFs (bro genes). The sequence identity between the HzSNPV and HaSNPV hrs ranges from 90% (hr1) to almost 100% (hr5) and the hrs differ in the presence/absence of one or more type A and/or B repeats. The three HzSNPV bro genes differ significantly from those in HaSNPV and may have been acquired independently in the ancestral past. The sequence data suggest strongly that HzSNPV and HaSNPV are variants of the same virus species, a conclusion that is supported by the physical and biological data.
There are several kinds of nutritious materials in Spirulina maximum, and beta-carotene is one of the most important materials. Because beta-carotene is of low polarity, for purification it was extracted with the mixture of acetone and methanol in the ratio of 7:2 (V/V), then saponified, and extracted with petroleum ether, purified with column packed with neutral Al2O3. Its content was determined by reversed-phase HPLC. This method is accurate and the results are reproducible. The average recovery was 96.8%.
Anthraquinones were histochemically locayed and content were determined in rhizome of Polygonum cuspidatum. Anthraquinones were located in the parenchyma cells of rhizome, including vascular ray, part of parenchyma cell in phloem, cortex and pith. Phelloderm and ray initial also accumulated a small amount anthraquinones. The content of total anthraquinones was highest in pith that consisted of parenchyma cells, and higher in bark (including phloem, cortex and periderm) than in xylem. The content of total anthraquinones was highest in three-year-old rhizome, and higher in biennial rhizome than in annual rhizome. It suggests that correlation exist between accumulation of anthraquinones and the growth age of rhizome.
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A 2,671 bp DNA carrying a type I PKS module with KS and AT domains from Streptomyces sp. FR-008 was cloned in-frame into the BamHI site immediately downstream of the PT7 promoter of the E. coli expression vector pET-15b, no considerable expression under IPTG induction was detected. The same PKS gene cloned downstream of the tandem PRPL promoters of pBV220 also yielded no over-expression under 42 degrees C induction. This gene was, however, over-expressed when it was cloned downstream of the tandem PRPT7 or PRPLPT7 promoters. In the case of the tandem PRPLPT7 promoters, the over-expression was dependent on the 42 degrees C plus IPTG double induction. While in the case of the tandem PRPT7 promoters, over-expression could be achieved when the gene was induced by IPTG or 42 degrees C individually or by IPTG and 42 degrees C double induction. Based on these experiences an expression vector pHZ330 containing the tandem PRPT7 promoters was constructed. In addition, the PKS protein expressed in E. coli was injected into rabbits to generate PKS-specific antibodies. Western blotting experiment indicated that these antibodies were PKS-specific which could be used either for the study of the PKS gene cluster or for the detection of the heterologous expression of Streptomyces sp. FR-008 PKS genes.
The body surface area of 100 Chinese adults (50 for each sex) was measured with the paper cast method and compared to the results estimated by the Stevenson's "height-weight-surface" formula. Our results shows that Stevenson's formula is no longer suitable for the Chinese. Our formulae for Chinese are as follows: SI=0.0061 x H + 0.0124 x W - 0.0099 (for both sexes), SII=0.0057 x H + 0.0121 - W + 0.0882 (for male), SIII=0.0073 H + 0.0127 x W - 0.2106 (for female) H: body height, W: body weight, S: body surface area
Objective. To find a real-time, quick and audio-visual method to evaluate the subject's physiological function condition and possible development. Method. Star figure technique was adopted to analyse multiple physiological indices during lower body negative pressure test (LBNP). Based on the character and stability of the stars figure, the steadiness of the subjects physiological function can be judged. Result. Physiological function can be accurately assessed only when the model of stress response of an individual is formed. Conclusion. The changes of star figure can indicate the possible development of the physiological function stage.
In order to investigate the genomic organization of the single-nucleocapsid nucleopolyhedrovirus (SNPV) of Buzura suppressaria (BusuNPV), the HindIII-I fragment located at map units (mu) 26.6-29.4 of the viral genome was sequenced. The fragment contained two partial and three complete open reading frames (ORFs) representing the 3' end of a polyhedron envelope protein gene (pep), a homologue of the AcMNPV ORF117, a conotoxin-like protein gene (ctl), an inhibitor of apoptosis gene (iap) and a superoxide dismutase gene (sod), respectively. These five genes were identified for the first time in a SNPV. Sequence analysis further revealed that these ORFs have the same conserved motifs and gene structure as those observed in their homologues from other baculoviruses. Between ctl and iap, an intergenic region of about 700 basepairs with structure similar to non-hr origins of DNA replication was observed. The genomic arrangement of the ORFs in the BusuNPV HindIII-I fragment is very different from the arrangement of their homologues in the genome of Autographa californica multiple nucleocapsid (M) NPV and other baculoviruses to date. Our data suggest that on the basis of gene arrangement, BusuNPV belongs to a distinct taxon within the Baculoviridae family, corroborating our previous conclusions derived from phylogeny analysis of several BusuNPV genes.
The genome organization of the Buzura suppressaria single-nucleocapsid nucleopolyhedrovirus (BusuNPV) was largely elucidated and compared to those of other baculoviruses. A detailed physical map was constructed for the restriction enzymes BamHI, BglI, BglII, EcoRI, HindIII, KpnI, PstI, XbaI and XhoI. The 120.9 kbp viral genome was cloned as restriction fragments into a plasmid library from which about 43.5 kbp of dispersed sequence information was generated. Fifty-two putative open reading frames homologous to those of other baculoviruses were identified and their location in the genome of BusuNPV was determined. Although the gene content of BusuNPV is similar to that of Autographa californica multiple-nucleocapsid nucleopolyhedrovirus, Bombyx mori nucleopolyhedrovirus and Orgyia pseudotsugata multiple-nucleocapsid nucleopolyhedrovirus, the gene order is, however, significantly different from that observed in the other viruses, which have a high degree of collinearity. A new approach (GeneParityPlot) was developed to represent the differences in gene order among baculoviruses when limited sequence information is available and to take advantage of the high degree of gene conservation. The data obtained show that BusuNPV is a distinct baculovirus species and the analyses suggest that gene distribution along baculovirus genomes may be used as a phylogenetic marker.
In an attempt to investigate possible urban-rural difference in prevalence of hepatitis B and C virus (HBV and HCV, respectively) infection in continental China, triplet surveys on HBV and HCV infection markers (ie, HBsAg, anti-HBs, anti-HBc, and anti-HCV) and serum enzyme levels (AST, ALT and gamma-GTP) were conducted in 1997 on groups of apparently healthy adult women (49 to 50 subjects per group); one group (the City group) was in Xian, the provincial capital of Shaanxi Province, and two others (the Village A group and the Village B group) were in farming villages in the Province some 200 and 25 km away from Xian, respectively. Comparison among the three groups showed that there was no urban-rural difference in prevalence of HBV and HCV infection positive (HBV+ and HCV+) cases and that the overall prevalence of HBV+ and HCV+ cases was 70% and 3%, respectively. HBsAg+ prevalence was however higher in the villages (8% when the two villages were combined) than in the city (2%). HBV infection was not associated in general with apparent increase in emission enzyme levels in the serum, whereas HCV infection might be associated with an increase in ALT, AST and gamma-GTP. The present observation in combination with other previously published results suggests that urban-rural difference will not be remarkable in HBV and HCV infection prevalence in Continental China and that the public health problem is more serious with HBV infection and quite less so with HCV infection.
A putative ecdysteroid UDP-glucosyltransferase (egt) gene was identified in the single nucleocapsid nucleopolyhedrovirus of Buzura suppressaria (BusuNPV). This is the first egt gene to be characterized in a SNPV, suggesting that egt genes are prevalent in nucleopolyhedroviruses and possibly in all baculoviruses. The open reading frame (ORF) of the gene is 1539 nucleotides (nt) long, encoding a putative protein (EGT) of 513 amino acids (aa) with a M of 58922. The 5' noncoding region contains three possible TATA boxes. A polyadenylation signal, AATAAA, was found downstream of the translation stop codon. A putative signal peptide of 16 residues was present at the N-terminus of the EGT. The BusuNPV egt gene has a high degree of nucleotide and amino acid sequence homology to multiple nucleocapsid (M) NPV egt genes, the highest being to the Spodoptera exigua MNPV egt. A phylogenetic tree of eleven known EGTs was constructed using maximum parsimony analysis.
In the genomes of two baculoviruses, Spodoptera exigua and S. littoralis multicapsid nucleopolyhedroviruses (SeMNPV and SpliMNPV, respectively), an open reading frame (ORF) encoding the large subunit of ribonucleotide reductase (RR1) was identified. The predicted amino acid sequences of SeMNPV and SpliMNPV RR1 showed high homology to RR1 proteins from eukaryotes (ca. 70% and 80% similarity, respectively). The amino acid residues thought to be involved in catalytic function were conserved in the baculoviral RR1 ORFs. The RR1 ORFs in SeMNPV and SpliMNPV were located in different genomic positions. In SeMNPV, the RR1 ORF was located upstream of the polyhedrin gene, in an anti-genomic orientation. In SpliMNPV, the RR1 ORF preceded the p74 gene. By searching databanks, sequences homologous to the N terminus of RR1 were also detected upstream of the polyhedrin gene of three other baculoviruses, Mamestra brassicae multicapsid NPV, Panolis flammea multicapsid NPV and Orgyia pseudotsugata single nucleocapsid NPV. The baculovirus type species, Autographica californica multicapsid NPV, however, does not encode RR. A 2.7 kb transcript could be detected throughout infection with SeMNPV, classifying SeMNPV rr1 as an early gene. Primer extension analysis revealed several early and late start sites. None of the major start sites showed similarity to previously characterized baculoviral transcriptional start motifs. Phylogenetic analysis of prokaryotic, eukaryotic and viral RR1 proteins suggested that SeMNPV and SpliMNPV acquired the gene for RR1 from a eukaryotic source, but independently from each other.
The 252Cf-PDMS method is a 'mature' technique, having survived 20 years of research, development and application. Recent advances in the application of the method have led to the use of the technique in clinical quantitation studies, the development of a microscopic method for measuring chemical homogeneity, in situ applications where serial modifications can be made and studied in a sequential fashion and the utilization of the primary fragmentation patterns to correlate with primary structure. Future directions in research, development and application will focus more attention on the chemistry of the 252Cf-PDMS process and the understanding and control of gas-phase reactions that occur in the ejection plume. Predictions are that the application of the in situ modification technique could lead to a new approach to pharmacokinetic studies as well as cell surface interactions where 252Cf-PDMS is effectively used to expand the capabilities of in vitro studies of biological processes.