Biomedical subjects

Hao Li

Publications and source records attributed to Hao Li.

114 records · Page 7Linked to original sources

PubMed2002

[Reexamination of specific antibodies in sera of cystic echinococccosis patients with IgG negative seroresponse].

OBJECTIVE: To explore the factors of false negative antibody response in patients with echinococcosis granulosus (Eg) for improving immunodiagnosis. METHODS: Indirect ELISA and sandwich ELISA were used to detect the specific antibody of IgG subclass (IgG1, IgG2, IgG3, IgG4) and IgA, IgM, IgE, as well as circulating antigen (CAg) and immunocomplex (CIC) in sera of Eg patients with negative response of total IgG. RESULTS: Among 42 sera with IgG negative seroresponse, 32 were positive with IgG subclass, IgA, IgM or IgE antibody, 10 were negative in all 7 kinds of antibody response. The detection rate of specific IgG1, IgG4, IgA, IgM and IgE was 42.9%, 11.9%, 28.6%, 26.2% and 21.4% respectively, being significantly higher than in sera of the control. IgM level in children was higher than that in adults. IgG subclass in patients with liver Eg was higher than that of pulmonary hydatidosis, when testing with IgG1 combined one or two of the other six Ig antibodies. The highest positive rate (64.3%) was seen in IgG1 + IgA + IgM antibody system. The positive rate of CAg and CIC in IgG negative patients was 28.57% and 30.95%, respectively. CONCLUSION: The factors involved with seronegative response of total IgG in Eg patients might be low specific IgG, variant Ig antibody expression and formation of CIC. Combined detection of IgG1 + IgA + IgM could enhance the sensitivity of serological tests in Eg patients.

Adolescent↗

PubMed1999

Preparation, Characteristics and Toxicity of Ricin-containing Galactosyl Ceramide Liposomes.

Ricin-containing galactosyl ceramide liposomes (ricin-GCLs) lyophilized product was made by the dehydration-rehydration vesicles(DRV) method and its toxicity to human heptocarcinoma cell line 7721 and to mice was investigated. The results indicated that the maximum encapsulation efficiency of ricin was 74.1%. The distribution of ricin-GCLs' sizes accords with intravenous injection standard and changes little in half a year at 4 degrees. In the cytotoxicity assay, the ratio of ricin-GCLs' to free ricin's IC50 was 1.00:3.89, which indicated that the ricin entrapped in GCLs was more effective than the free one in killing human heptocarcinoma cell line 7721. In vivo, the mice's LD(50) of ricin-GCLs ((41.8+/-9.33) &mgr;g/kg)is more than that of free ricin ((30.6+/-8.49) &mgr;g/kg) by 36.29%. So, ricin entrapped in GCLs promotes its cytotoxicity and reduces its toxic side-effect.

Journal Article↗

PubMedDate not supplied

Development of a HPLC-MS assay for ginsenoside Rh2, a new anti-tumor substance from natural product and its pharacokinetic study in dogs.

To develop a HPLC-MS method of determining ginsenoside Rh2 in dog plasma based on solid-phase extraction for pharmacokinetic studies. Six dogs were randomly assigned to two groups, either given 0.1 mg/kg dose intravenously or 1 mg/kg dose through oral gavage. Analysis using high performance liquid chromatography (HPLC) with ODS column, followed by detection with electrospray ionization(ESI) mass spectrometry(MS) in negative ion mode with 500 microM ammonium chloride in the mobile phase. The assays were validated over the concentration range of 2.0-1250.0 ng/ml in dog plasma. The intra- and inter- day precision were less than 10% in terms of RSD. The overall recovery was more than 80%. The validated assay was suitable for pharmacokinetic studies of ginsenoside Rh2 and the observed oral bioavailabilities of Rh2 were 17.6% and 24.8% for male and female dogs respectively.

Animals↗

PubMedDate not supplied

Thermosensitive lanthanide complexes of hyaluronan.

Addition of trivalent lanthanide salts to solutions of hyaluronan (HA), a naturally occurring anionic polysaccharide, resulted in an unexpected reverse-temperature phase transition (RTPT); i.e., the complexes were soluble when cooled but precipitated when warmed. A unique lower critical solution transition temperature (LCST) was observed for each lanthanide in the order (increasing LCST) Eu(3+) < Nd(3+)< Ce(3+) < Gd(3+) < La(3+) < Tb(3+) < Dy(3+) < Yb(3+) < Lu(3+) for high molecular weight HA. Moreover, the LCST values increased as the molecular weight of the HA decreased from 1730 to 190 kDa. The precipitation-dissolution behavior was fully reversible in a cyclical fashion; a lag in redissolution was observed as the temperature was lowered, and longer incubation times at each temperature minimized this lag. The RTPT behavior could be ablated by titration with 8 kDa HA to produce complexes soluble at ambient temperature. This is the first description of RTPT behavior in a biologically important glycosaminoglycan.

Chemical Precipitation↗

PubMedDate not supplied

Synthesis and biological evaluation of a cross-linked hyaluronan-mitomycin C hydrogel.

A cross-linked hyaluronan (HA) hydrogel that contained a covalently bound derivative of the anti-proliferative drug mitomycin C (MMC) was synthesized and evaluated in vitro and in vivo. The HA-MMC hydrogel was prepared by coupling MMC-aziridinyl-N-acrylate with thiol-modified HA followed by cross-linking with poly(ethylene glycol) diacrylate (PEGDA). MMC was released from 0.5% and 2.0% MMC films by hydrolysis in proportion to the MMC loading. When incubated in vitro with human T31 tracheal scar fibroblasts, 0.5% MMC films inhibited proliferation, whereas 2.0% MMC films were cytotoxic. When implanted in vivo into a rat peritoneal cavity, neither 0.5% nor 2.0% HA-MMC films elicited a severe peritoneal fluid leukocyte response. Importantly, MMC reduced the thickness of fibrous tissue formed surrounding the implanted films. Thus, cross-linked HA-MMC films have strong potential as anti-fibrotic barriers for the prevention of post-surgical adhesions.

Animals↗

PubMedDate not supplied

Linkage of a locus determining familial progressive hyperpigmentation (FPH) to chromosome 19p13.1-pter in a Chinese family.

Familial progressive hyperpigmentation (FPH) is a rare autosomal dominantly inherited disorder characterized by patches of hyperpigmentation in the skin which are present at birth or in early infancy and increase in size and number with age. Although previous studies showed that FPH is a monogenic trait, the genetic basis for this disease is unknown. Using a genome screening with 182 STR markers from autosomes in a three-generation Chinese family with 17 members, including 6 affected individuals, we identified a locus linked to chromosome 19p13.1-pter responsible for FPH, spanning 45.48 cM between D19S593 and 19pter. Interestingly, this region harbors the LKB1 gene, in which germline mutations were shown to be associated with Peutz-Jeghers Syndrome (PJS). PJS and FPH share the disorder of hyperpigmentation, the fine mapping of the FPH gene is expected to lead to a better understanding of the etiology for both FPH and PJS. The linkage of FPH locus to human chromosome 19p13.1-pter provides a genetic basis for further fine mapping.

China↗